WorldWideScience

Sample records for nobelium vorbereitende untersuchungen

  1. Nobelium non-believers

    Science.gov (United States)

    Thornton, Brett F.; Burdette, Shawn C.

    2014-07-01

    Alfred Nobel's eponymous element, nobelium, was 'first' discovered either in the 1950s or 1960s, in the USSR, Sweden or the USA. Brett F. Thornton and Shawn C. Burdette delve into the ensuing decades of internecine strife over the discovery of element 102.

  2. Penning trap mass measurements on nobelium isotopes

    International Nuclear Information System (INIS)

    Dworschak, M.; Block, M.; Ackermann, D.; Herfurth, F.; Hessberger, F. P.; Hofmann, S.; Vorobyev, G. K.; Audi, G.; Blaum, K.; Droese, C.; Marx, G.; Schweikhard, L.; Eliseev, S.; Ketter, J.; Fleckenstein, T.; Haettner, E.; Plass, W. R.; Scheidenberger, C.; Ketelaer, J.; Kluge, H.-J.

    2010-01-01

    The Penning trap mass spectrometer SHIPTRAP at GSI Darmstadt allows accurate mass measurements of radionuclides, produced in fusion-evaporation reactions and separated by the velocity filter SHIP from the primary beam. Recently, the masses of the three nobelium isotopes 252-254 No were determined. These are the first direct mass measurements of transuranium elements, which provide new anchor points in this region. The heavy nuclides were produced in cold-fusion reactions by irradiating a PbS target with a 48 Ca beam, resulting in production rates of the nuclei of interest of about one atom per second. In combination with data from decay spectroscopy our results are used to perform a new atomic-mass evaluation in this region.

  3. On laser spectroscopy of the element nobelium (Z=102)

    International Nuclear Information System (INIS)

    Laatiaoui, M.; Backe, H.; Lauth, W.; Block, M.; Hessberger, F.P.; Kunz, P.; Lautenschlaeger, F.; Walther, T.; Sewtz, M.

    2014-01-01

    Optical transitions were sought for in 254 No, which was produced at the UNILAC accelerator at GSI in the reaction 208 Pb( 48 Ca, 2n) 254 No. After separation from the projectile beam by the velocity filter SHIP, the nobelium ions were stopped inside a buffer gas cell and guided onto a tantalum filament. The activation energy for desorption of nobelium from tantalum was determined to be 246 (24) kJ/mol. In a first experiment, the search for the 7s7p 1 P 1 level of nobelium by laser resonance ionization spectroscopy was started. Based on level predictions by multi-configuration Dirac-Fock and relativistic coupled-cluster calculations, the wavenumber ranges from 25900 cm -1 to 28260 cm -1 and from 28040 cm -1 to 31000 cm -1 were scanned with two excimer laser-pumped dye lasers and a frequency doubled Nd:YAG laser pumped OPO system, respectively. The measurements delivered no clear evidence for a resonance. However, five wavenumber positions, viz. 27997 cm -1 , 28015 cm - 1, 28230 cm -1 , 28792 cm -1 , and 29516 cm -1 , remain potential candidates for the transition and subject for upcoming investigations. (authors)

  4. Laser spectroscopy of nobelium (Z=102) in a buffergas cell; Laserspektroskopie an Nobelium (Z=102) in einer Puffergaszelle

    Energy Technology Data Exchange (ETDEWEB)

    Lautenschlaeger, Felix

    2016-10-15

    Relativistic effects scaling with Z{sup 2} are responsible for changes in the atomic structure of the heaviest elements due to their growing influence on the inner electrons. Thus for studying relativistic effects, high-sensitive experimental techniques to extract atomic properties are needed. A recommended technique for this purpose is the so called RAdiation detected Resonance Ionisation Spectroscopy (RADRIS) [1,2]. During this work, laser spectroscopic studies on the element nobelium (Z=102) have been performed for the first time. The RADRIS technique was exploited using a buffergas filled stopping cell with the goal to increase the overall efficiency of this method.

  5. First direct mass measurements on nobelium and lawrencium with the Penning trap mass spectrometer SHIPTRAP

    Energy Technology Data Exchange (ETDEWEB)

    Dworschak, Michael Gerhard

    2009-12-08

    The Penning trap mass spectrometer SHIPTRAP at GSI Darmstadt was set up for high-precision mass measurements of heavy radionuclides produced in fusion evaporation reactions and separated from the primary beam by the velocity filter SHIP. It consists of a gas stopping cell for the deceleration of the high energetic reaction products, an RFQ cooler and buncher for cooling and accumulation of the ions, and a double Penning trap system to perform mass measurements. The mass is determined by measuring the cyclotron frequency of the ion of interest in a strong homogeneous magnetic field and comparing it to the frequency of a well-known reference ion. With this method relative uncertainties in the order of 10{sup -8} can be achieved. Recently, mass measurements of the three nobelium isotopes {sup 252-254}No (Z=102) and the lawrencium isotope {sup 255}Lr (Z=103) were performed successfully. These were the first direct mass measurements of transuranium elements ever per- formed. The production rate of the atoms of interest was about one per second or less. The results of the measurements on nobelium confirm the previous mass values which were deduced from Q{sub {alpha}} values. In the case of {sup 255}Lr the mass excess value, which was previously only estimated from systematic trends, was for the first time directly measured. These results mark the first step in the exploration of the region of transuranium elements which is planned at SHIPTRAP. The main objective is to fix the endpoints of {alpha} decay chains which are originating from superheavy elements close to the predicted island of stability. (orig.)

  6. Impact of buffer gas quenching on the 1S0 → 1P1 ground-state atomic transition in nobelium

    International Nuclear Information System (INIS)

    Chhetri, P.; Lautenschlaeger, F.; Ackermann, D.; Backe, H.; Lauth, W.; Block, M.; Duellmann, C.E.; Goetz, S.; Cheal, B.; Wraith, C.; Even, J.; Ferrer, R.; Giacoppo, F.; Hessberger, F.P.; Khuyagbaatar, J.; Kishor Mistry, A.; Raeder, S.; Yakushev, A.; Kaleja, O.; Kunz, P.; Laatiaoui, M.; Minaya Ramirez, E.; Walther, T.

    2017-01-01

    Using the sensitive Radiation Detected Resonance Ionization Spectroscopy (RADRIS) technique an optical transition in neutral nobelium (No, Z = 102) was identified. A remnant signal when delaying the ionizing laser indicated the influence of a strong buffer gas induced de-excitation of the optically populated level. A subsequent investigation of the chemical homologue, ytterbium (Yb, Z = 70), enabled a detailed study of the atomic levels involved in this process, leading to the development of a rate equation model. This paves the way for characterizing resonance ionization spectroscopy (RIS) schemes used in the study of nobelium and beyond, where atomic properties are currently unknown. (authors)

  7. Impact of buffer gas quenching on the 1S0 → 1P1 ground-state atomic transition in nobelium

    NARCIS (Netherlands)

    Chhetri, Premaditya; Ackermann, Dieter; Backe, Hartmut; Block, Michael; Cheal, Bradley; Düllmann, Christoph Emanuel; Even, Julia; Ferrer, Rafael; Giacoppo, Francesca; Götz, Stefan; Heßberger, Fritz Peter; Kaleja, Oliver; Khuyagbaatar, Jadambaa; Kunz, Peter; Laatiaoui, Mustapha; Lautenschläger, Felix; Lauth, Werner; Ramirez, Enrique Minaya; Mistry, Andrew Kishor; Raeder, Sebastian; Wraith, Calvin; Walther, Thomas; Yakushev, Alexander

    2017-01-01

    Using the sensitive Radiation Detected Resonance Ionization Spectroscopy (RADRIS) technique an optical transition in neutral nobelium (No, Z = 102) was identified. A remnant signal when delaying the ionizing laser indicated the influence of a strong buffer gas induced de-excitation of the optically

  8. Untersuchungen an Eisen- und Lanthanoidhaltigen Koordinationsclustern mit Triazolat- sowie Semiquinonato-Liganden

    OpenAIRE

    Kriese, Thomas

    2016-01-01

    Magnetische Untersuchungen an Lanthanoiddimeren mit Semiquinonato-Liganden. Gemischtvalente Eisen-Koordinationsclustern. Lanthanoid-Koordinationscluster mit zwölf Lanthanoiden aber mit verschiedenen Clusterladungen.

  9. Untersuchungen über Veronica triloba (Opiz) Kerner in Rheinhessen

    OpenAIRE

    Oesau, Albert

    1981-01-01

    Untersuchungen in den Jahren 1977-1979 ergaben, daß Veronica triloba (Opiz) Kerner, eine Sippe aus dem Veronica hederifolia-Aggregat, in Rheinhessen überraschenderweise weit verbreitet ist und bisher übersehen wurde. Sie siedelt vor allem in Ackerunkraut- und Felsgrus-Gesellschaften sowie lückigen Trockenrasen, ohne eine gesellschaftsspezifische Bindung zu zeigen. Gut ausgeprägte morphologische Merkmale gestatten eine sichere Differenzierung gegenüber den übrigen Sippenvertretern V. hederifol...

  10. Pharmakobotanische Untersuchungen von Lavendelsorten auf dem Plattensee- Plateau

    Directory of Open Access Journals (Sweden)

    Tóth, Frida

    2014-09-01

    Full Text Available Auf dem Hof Dörgicsei Levendula Major GmbH wurden 9 Lavendelsorten (6 Sorten von Lavandula angustifolia und 3 Sorten von Lavandula x intermedia untersucht. Neben den morphologischen und Wachstumseigenschaften wurden auch Frisch- und Trockengewichte bewertet. Quantitative und qualitative Untersuchungen von den Blüten- und Ätherischöldrogen wurden auch durchgeführt. Die statistische Analyse zeigte signifikant höhere Erträge bei den Sorten L. angustifolia ’Essence Purple’ und L. x intermedia ’Edelweiss’. Gehalt und Zusammensetzung von ätherischem Öl war eindeutig bei der Sorte L. angustifolia ’Ellagance Purple’ am günstigsten.

  11. Towards optical spectroscopy of the element nobelium (Z = 102) in a buffer gas cell. First on-line experiments on {sup 155}Yb at the velocity filter SHIP with a novel ion collection and atom re-evaporation method of high efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Backe, H.; Kunz, P.; Lauth, W.; Dretzke, A.; Horn, R.; Kolb, T. [Mainz Univ., Institut fur Kernphysik (Germany); Laatiaoui, M.; Sewtz, M. [Munchen Ludwig-Maximilians-Univ., Dept. fur Physik, Garching (Germany); Ackermann, D.; Block, M.; Herfurth, F.; Hebberger, F.P.; Hofmann, S.; Mann, R. [Gesellschaft fur Schwerionenforschung, Darmstadt (Germany)

    2007-10-15

    For the investigation of the atomic level structure of heavy elements which can only be produced at on-line facilities such as GSI (Darmstadt, Germany), a novel experimental procedure has been developed. It is based on Radiation Detected Resonance Ionization Spectroscopy (RADRIS) and can be applied to elements like nobelium produced at rates of a few ions per second. Fusion reaction products are separated from the primary beam by the velocity filter SHIP at GSI, stopped in a buffer gas cell, collected on a tantalum filament and then re-evaporated as atoms. The ions produced by resonance ionization with tunable laser beams are detected via their characteristic alpha decay. First on-line experiments on alpha-active {sup 155}Yb, which is supposed to have an atomic level structure similar to nobelium, were performed. These test experiments focused on the optimization of the collection and re-evaporation process of the radioactive ions, the laser ionization efficiency and the detection via alpha decay. An overall efficiency for RADRIS of 0.8% with respect to the target production rate was measured. While further improvements of this efficiency are in progress it should already be sufficient for the search for atomic levels in nobelium. (authors)

  12. Towards optical spectroscopy of the element nobelium (Z = 102) in a buffer gas cell. First on-line experiments on 155Yb at the velocity filter SHIP with a novel ion collection and atom re-evaporation method of high efficiency

    International Nuclear Information System (INIS)

    Backe, H.; Kunz, P.; Lauth, W.; Dretzke, A.; Horn, R.; Kolb, T.; Laatiaoui, M.; Sewtz, M.; Ackermann, D.; Block, M.; Herfurth, F.; Hebberger, F.P.; Hofmann, S.; Mann, R.

    2007-01-01

    For the investigation of the atomic level structure of heavy elements which can only be produced at on-line facilities such as GSI (Darmstadt, Germany), a novel experimental procedure has been developed. It is based on Radiation Detected Resonance Ionization Spectroscopy (RADRIS) and can be applied to elements like nobelium produced at rates of a few ions per second. Fusion reaction products are separated from the primary beam by the velocity filter SHIP at GSI, stopped in a buffer gas cell, collected on a tantalum filament and then re-evaporated as atoms. The ions produced by resonance ionization with tunable laser beams are detected via their characteristic alpha decay. First on-line experiments on alpha-active 155 Yb, which is supposed to have an atomic level structure similar to nobelium, were performed. These test experiments focused on the optimization of the collection and re-evaporation process of the radioactive ions, the laser ionization efficiency and the detection via alpha decay. An overall efficiency for RADRIS of 0.8% with respect to the target production rate was measured. While further improvements of this efficiency are in progress it should already be sufficient for the search for atomic levels in nobelium. (authors)

  13. Untersuchungen ausgewählter Nierenkrankheiten beim Frettchen (Mustela putorius f. furo L. 1758)

    OpenAIRE

    Riechert, Maren

    2005-01-01

    Um Häufigkeit, Bedeutung und diätetische Ursachen veränderter Nieren beim Frettchen zu erarbeiten, wurden die Nieren von 63 Heimtieren und 120 Labortieren sonographisch untersucht und Fütterungsanalysen durchgeführt. Anatomische Studien an gesunden Nieren wurden für den Vergleich mit den veränderten Nieren angefertigt. Die Untersuchungen zur Anatomie ergaben für das Frettchen Nieren vom einfachen glatten und einwarzigen Typ. Des Weiteren konnten mithilfe von anatomischen ...

  14. Investigations of pollutant migration using lysimeters; Untersuchungen zur Schadstoff-Migration in Lysimetern

    Energy Technology Data Exchange (ETDEWEB)

    Klotz, D. (ed.)

    2002-07-01

    The third GSF Lysimeter Workshop focused on pollutant migration in underground strata, i.e. the dispersion of water constituents as referred to water transport on the basis of ideal tracer investigations. [German] Der am 29./30.04.2002 stattgefundene Workshop 'Untersuchungen zur Schadstoffmigration in Lysimetern' war der dritte GSF-Lysimeterworkshop nach denen in den Jahren 1998 und 2000 veranstalteten. Nachdem in den Jahren 1998 und 2000 der Wassertransport und die Bestimmung der Sickerwassergeschwindigkeit in Lysimetern im Mittelpunkt standen, war 2002 die Schadstoffmigration im Untergrund der Schwerpunkt der Vortraege und Poster. Unter Migration wird das Ausbreitungsverhalten von Wasserinhalts-(Fremd-, Schad-)Stoffen bezogen auf den Wassertransport, bestimmt mit idealen Tracern, verstanden. (orig.)

  15. Investigation of LPP combustors under elevated pressure conditions; Untersuchungen zu LPP-Flugtriebwerksbrennkammern unter erhoehtem Druck

    Energy Technology Data Exchange (ETDEWEB)

    Fink, R.

    2001-05-01

    The development of new combustor concepts for aero engines to meet future emissions regulations in based on a detailed knowledge of the combustion process and the velocity field. In the presented thesis, non intrusive measurements were performed in a model combustion chamber under almost realistic pressure and temperature conditions. The species OH, NO, unburned hydrocarbons and fuel droplets were detected in 2 dimensions with the Laser Induced Fluorescence (LIF). The velocity field was measured with the Particle Image Velocimetry technique (PIV). [German] Die Weiterentwicklung neuer Brennkammerkonzepte zur Erfuellung zukuenftiger Schadstoffemissionsrichtlinien erfordert genaue Kenntnisse der ablaufenden Verbrennungs- und Stroemungsvorgaenge in der Brennkammer. Bei den in der Arbeit vorgestellten Untersuchungen wurden in einer LPP-Modellbrennkammer unter annaehernd realistischen Eintrittsbedingungen die Spezies OH, NO, unverbrannte Kohlenwasserstoffe sowie noch fluessiger Brennstoff zweidimensional anhand der Laserinduzierten Fluoreszenz (LIF) nachgewiesen. Das Stroemungsfeld wurde mit Hilfe der Particle Image Velocimetry (PIV) gemessen.

  16. Untersuchungen zur Involution der Vagina and Zervix beim Rind post partum unter Berücksichtigung der Zervix als Geburtshindernis

    OpenAIRE

    Wehrend, Axel

    2002-01-01

    Ziel der vorliegenden Arbeit war es die physiologische Involution der Zervix im Vergleich zur Vagina beim Rind während der ersten zehn Tage post partum zu charakterisieren. Weiterhin sollte durch klinische Untersuchungen an Kühen nach Dystokie und einer retrospektiven Datenauswertung von Schwergeburten unterschiedlicher Tierarten der Anteil zervikal bedingter Geburtsstockungen im Interspeziesvergleich analysiert und Einflussfaktoren auf das Auftreten dieser Dystokieform sowie Störungen in der...

  17. Clinically relevant incidental cardiovascular findings in CT examinations; Klinisch relevante kardiovaskulaere Zufallsbefunde bei CT-Untersuchungen

    Energy Technology Data Exchange (ETDEWEB)

    Voigt, P.; Fahnert, J.; Kahn, T.; Surov, A. [Universitaetsklinikum Leipzig, Klinik fuer Diagnostische und Interventionelle Radiologie, Leipzig (Germany); Schramm, D.; Bach, A.G. [Universitaetsklinikum Halle (Saale), Klinik fuer Radiologie, Halle (Germany)

    2017-04-15

    Incidental cardiovascular findings are a frequent phenomenon in computed tomography (CT) examinations. As the result of a dedicated PubMed search this article gives a systemic overview of the current literature on the most important incidental cardiovascular findings, their prevalence and clinical relevance. The majority of incidental cardiovascular findings are of only low clinical relevance; however, highly relevant incidental findings, such as aortic aneurysms, thromboses and thromboembolic events can also occasionally be found, especially in oncology patients. The scans from every CT examination should also be investigated for incidental findings as they can be of decisive importance for the further clinical management of patients, depending on their clinical relevance. (orig.) [German] Inzidentelle kardiovaskulaere Befunde sind ein haeufiges Phaenomen bei CT-Untersuchungen. Mit dieser Arbeit soll nach gezielter PubMed-Recherche ein systematischer Literaturueberblick ueber die wichtigsten kardiovaskulaeren Zufallsbefunde sowie deren Haeufigkeit und klinische Relevanz gegeben werden. Die Mehrzahl der inzidentellen kardiovaskulaeren Befunde sind klinisch nur von untergeordneter Bedeutung, allerdings werden immer wieder auch hochgradig relevante Zufallsbefunde wie beispielsweise Aortenaneurysmata oder - gerade bei onkologischen Patienten - Thrombosen und thrombembolische Ereignisse detektiert. Jede CT-Untersuchung sollte gezielt nach inzidentellen Befunden durchsucht werden, da diese je nach klinischer Relevanz von entscheidender Bedeutung fuer das weitere klinische Management des Patienten sein koennen. (orig.)

  18. PAH analysis in Leipzig allotment soils; Untersuchungen zum Gefaehrdungspotential polycyclischer aromatischer Kohlenwasserstoffe (PAK) in Leipziger Kleingartenboeden

    Energy Technology Data Exchange (ETDEWEB)

    Bittrich, R.; Butze, B.; Mueller, S.; Prawalsky, R.; Stoye, H. [Umwelt-Consult e.V., Leipzig (Germany)

    2000-09-01

    Soils in 29 allotments were analyzed systematically with a view to the following aspects: Concentration ratios of the 16 components analyzed. Occurrence and classification of so-called PAH patterns. Interdependences between PAH patterns and soil features. PAH concentrations and soil-immanent buffer characteristics (humus concentration, pH, clay concentration, sesquioxide concentrations, exchange capacity). [German] Die vorliegende Arbeit konzentriert sich auf die Untersuchung der PAK-Belastung kleingaertnerisch genutzter Boeden. Die hier vorgestellten Ergebnisse resultieren aus Probjekten von Umwelt-Consult e.V. aus den Jahren 1995 bis 1997 im Auftrag der Stadt Leipzig und dem unter fachlicher Begleitung des Referates Geochemie der Abt. Boden/Geochemie vom LfUG gefoerderten Forschungsvorhaben 'Untersuchungen zum Gefaehrdungspotential polycyclischer aromatischer Kohlenwasserstoffe (PAK) in Boeden der Stadt Leipzig'. Hierbei wurden systematisch Boeden in 29 Kleingartenanlagen untersucht. Folgende Fragestellungen sollten beantwortet werden: Stehen die PAK-Konzentrationen der 16 analysierten Einzelkomponenten in bestimmten Groessenverhaeltnissen zueinander? Sind sogenannte PAK-Muster zu erkennen und lassen sich diese klassifizieren? Welche Beziehungen gibt es zwischen PAK-Mustern und Bodenmerkmalen? Korrespondieren die PAK-Konzentrationen (Gesamt-PAK, Einzelkomponenten) im Boden und deren bodenhorizont-bezogene Abfolge mit der Auspraegung bodenimmanenter Puffermerkmale (Humusgehalt, pH-Wert, Tongehalt, Gehalt an Sesquioxiden, Austauschkapazitaet)? (orig.)

  19. Logfile-Analysen: Möglichkeiten und Grenzen ihrer Nutzung bei Untersuchungen zur Mensch-Maschine-Interaktion

    Directory of Open Access Journals (Sweden)

    Burkhard Priemer

    2004-06-01

    Full Text Available Die Aufzeichnung der Computernutzung in automatisch generierten elektronischen Protokollen – so genannten Logfiles – entwickelt sich zu einer zunehmend genutzten Erfassungsmethode bei Untersuchungen der Interaktion zwischen Mensch und Computer. Dieser Beitrag bietet einen einführenden Überblick über Verfahren der Logfile-Aufzeichnung und der Analyse der Daten. Neben einer Erläuterung der Begrifflichkeiten werden sowohl Vor- und Nachteile von Logfile-Auswertungen als auch grundlegende Methoden, mathematische Beschreibungen des Nutzerverhaltens und Ansätze der Typisierung von Nutzeraktivitäten dargestellt.

  20. Feinkartierung von Loss of Heterozygosity-Intervallen auf Chromosom 11p und Untersuchungen zum Expressions- und Methylierungsstatus von FANCF beim Ovarialkarzinom

    OpenAIRE

    Schulze, Kathrin

    2011-01-01

    Um Tumorsuppressorgene beim Ovarialkarzinom zu identifizieren wurde eine Kartierung von LOH-Intervallen der Region 11p15.5 - 11p11.2 mittels 11 Mikrosatellitenmarkern an 47 Ovarialtumorproben vorgenommen. Im Bereich des ST5- und AFM255/KAI1-Locus konnten potentielle Intervalle abgegrenzt werden. Das Fanconi Anämie Gen FANCF wurde für Untersuchungen zum Expressions- und Methylierungsstatus ausgewählt, da dessen Abschaltung mit einem besseren Ansprechen auf Cisplatin bei Ovarialkarzinompatienti...

  1. Studies on agglomeration of colloidal suspensions in an alternating electric field; Untersuchungen zur Agglomeration kolloidaler Suspensionen im elektrischen Wechselfeld

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, M. [Inst. fuer Mechanische Verfahrenstechnik und Mechanik, Univ. Karlsruhe (Germany); Loeffler, F. [Inst. fuer Mechanische Verfahrenstechnik und Mechanik, Univ. Karlsruhe (Germany)

    1996-07-01

    Colloidal solutions contain particles in the {mu}m range whose agglomeration and coagulation is of interest for certain applications. `Electrocoagulation` means that in an electric field droplets or particles in a disperse phase have higher kinetic energy so that the probability of overcoming repulsive forces and of forming bigger aggregates will increase. The electrocoagulation technique is applied for emulsion cracking of water-in-oil systems (desalination and dewatering of petroleum, petroleum cracking) and, in some cases, also for cracking oil-in-water systems. Removal of colloidal solids from aqueous solution during electrochemical waste water treatment is often carried out with the aid of dissolving aluminium or iron electrodes. The authors describe experiments in which the flow of an electric current, which would cause the electrodes to dissolve, was to be prevented. An alternating field was to induce oscillation of the particles, i.e. relative motion of the particles with respect to each other. (orig./SR) [Deutsch] Kolloidale Loesungen enthalten Partikel im {mu}m-Bereich. In manchen Bereichen ist deren Agglomeration bzw. Koagulation von Interesse. Unter dem Begriff der Elektrokoagulation versteht man im allgemeinen das Phaenomen, dass in einem elektrischen Feld Tropfen oder Partikel in einer dispersen Phase eine hoehere kinetische Energie besitzen, und dadurch die Wahrscheinlichkeit zur Ueberwindung von Abstossungskraeften und zur Bildung groesserer Aggregate steigt. Das Verfahren der Elektrokoagulation wird bisher zur Emulsionsspaltung von Wasser/Oel-Systemen (Entsaltzung und Entwaesserung von Erdoel/Erdoelspaltung) und z.T. auch zur Spaltung von Oel/Wasser-Systemen eingesetzt. Zur Entfernung kolloidaler Feststoffe aus waessrigen Loesungen bei der elektrochemischen Aufarbeitung von Abwasser wird haeufig mit sich aufloesenden Aluminium- oder Eisenelektroden gearbeitet. In den im folgenden dargestellten Untersuchungen sollte ein Stromfluss durch die

  2. Toxicology of ozone on the basis of animal and clinical experimental studies; Toxikologie von Ozon auf der Grundlage tier- und klinisch-experimenteller Untersuchungen

    Energy Technology Data Exchange (ETDEWEB)

    Kappus, H. [Humboldt-Universitaet, Berlin (Germany). Virchow-Klinikum

    2000-07-01

    This synopsis focuses on the toxic effects of ozone in humans and animals following inhalation. It is limited to studies that deal exclusively with ozone. These studies are reviewed with respect to action mechanisms underlying ozone-specific toxicity and, where present, dose-effect relationships. Both aspects today are indispensable for any risk assessment. As there have been very many studies on this issue and the number of publications increases every year, the present paper only quotes a few review articles and does not mention original papers unless they are of recent date or offer new information. [German] Diese Uebersicht konzentriert sich auf die toxischen Effekte von Ozon nach Inhalation bei Mensch und Tier. Nur Untersuchungen mit Ozon alleine werden miteinbezogen. Sie werden hauptsaechlich im Zusammenhang mit dem Wirkungsmechanismus der Ozon-bedingten Toxizitaet und, soweit vorhanden, Konzentrations-Wirkungsbeziehungen behandelt. Beide Aspekte sind heute fuer eine Risikoabschaetzung unerlaesslich. Da sehr viele Untersuchungen vorliegen und die Zahl der Veroeffentlichungen jaehrlich ansteigt, sollen hier nur einige neuere Uebersichtsarbeiten zitiert werden und Originalarbeiten nur dann erwaehnt werden, wenn sie neueren Datums sind bzw. zusaetzliche Informationen bringen. (orig.)

  3. Image quality of paper prints compared to film copies in CT investigations; Bildqualitaet von Papierausdrucken zur Befunddokumentation im Vergleich zu Laserfilmen bei MSCT-Untersuchungen

    Energy Technology Data Exchange (ETDEWEB)

    Bley, T.; Burger, D.; Ghanem, N.; Thuerl, C.; Saueressig, U.; Kotter, E.; Langer, M. [Abt. Roentgendiagnostik, Radiologische Klinik, Universitaetsklinikum Freiburg (Germany)

    2002-04-01

    Purpose: Evaluation of image quality of paper prints in routine CT investigations. Method: The image quality of paper prints from 104 CT scans of daily routine investigations was analysed by three observer three observers according to a five-point ranking scale for contrast, grey level, spatial resolution, and subjective confidence in correct evaluation. Each study was rated ''acceptable'' or ''not acceptable for documentation''. Results: In 312 ratings the mean grade for contrast was 2.7, for grey levels 3.2, and for spatial resolution 3.3. Grades ranged from 1 = very good to 5 = insufficient. Subjective confidence in correct evaluation was rated as ''certain'' in 77.4%, ''likely'' in 18.4% and ''impossible to evaluate'' in 4.2% of cases. 93.7% of printed CT images were rated ''acceptable for documentation''. Conclusion: Image quality of paper prints does not reach the quality of laser films concerning its contrast, grey levels, and spatial resolution. Nevertheless, paper prints are acceptable for documentation of findings in most CT investigations. A high confidence in correct evaluation was found. Limitations are found in documentation of small coin lesions of the lung and ischemic lesions of the neurocranium. (orig.) [German] Ziel: Qualitaetsbewertung von Papierausdrucken zur Bilddokumentation von Routine-CT-Untersuchungen. Material und Methoden: Bei 104 Routine-CT-Untersuchungen werteten drei Untersucher (insgesamt 312 Auswertungen) die Bildqualitaet von Papierausdrucken im Vergleich zu Laserfilmen bezueglich Kontrast, Grauwerten und Aufloesung sowie ''persoenlicher Befundsicherheit'' (Skala 1 - 5) aus. Abschliessend wurde entschieden, ob der Papierausdruck fuer die Befunddokumentation ausreiche. Ergebnisse: Mit Bewertungen zwischen 1 fuer ''sehr gut'' und 5 fuer &apos

  4. Investigations of co-combustion of plastics in a coal dust furnace; Untersuchungen zur Mitverbrennung von Kunststoffen in einer Kohlestaubfeuerung

    Energy Technology Data Exchange (ETDEWEB)

    Gerhardt, T.; Spliethoff, H.; Hein, K.R.G. [Stuttgart Univ. (Germany). Inst. fuer Verfahrenstechnik und Dampfkesselwesen (IVD); Christill, M.; Kicherer, A.; Seifert, H. [BASF AG, Verfahrenstechnik-ZET/EH-L544, Ludwigshafen am Rhein (Germany)

    1996-12-31

    In a cooperation project of the Institute of Process Engineering and Power Plant TEchnology (IVD) at the University of Stuttgart and the BASF AG, investigations of co-combustion of plastic material in a coal dust furnace were carried out. The central question of the research work was the ignition and burnout of the particles in dependence of the residence time in the hot part of the furnace. Particle sizes were varied with the aim to define the largest possible particle size in order to minimize the cost of fuel preparation by grinding. On the other hand, tests were made with pure materials and synthetic mixtures of these in order to characterize the influence of different types of plastic. The investigations showed that plastics are suited as fuels for coal dust furnaces, and that the cost of fuel preparation can be reduced to an acceptable level. With polyethylene, which is difficult to ignite, an upper particle size limit of 1.25 to 1.5 mm was reached in the IVD test stand. In industrial applications with a different burner arrangement, even better results may be expected. (orig/AKB) [Deutsch] In einer Zusammenarbeit zwischen dem Institut fuer Verfahrenstechnik und Dampfkesselwesen (IVD) der Universitaet Stuttgart und der BASF AG wurden Versuche zur Coverbrennung von Kunststoffen in einer Kohlenstaubfeuerung durchgefuehrt. Im Mittelpunkt der Untersuchungen standen Zuendung und Abbrand der Kunststoffpartikel in Abhaengigkeit von der Verweilzeit im heissen Bereich der Brennkanner. Variiert wurden hierzu zum einen die Partikelgroessen mit dem Ziel, den Aufbereitungsaufwand durch Zerkleinerung zu minimieren. Zur Charakterisierung der Einfluesse verschiedener Kunststoffarten wurden die Versuche mit unterschiedlichen Reinkunststoffen und synthetischen Mischungen durchgefuehrt. Die Versuche zeigen, dass sich Kunststoffe mit vertretbarem Mahlaufwand in der Staubfeuerung einsetzen lassen. Am Beispiel des Polyethylen, eines der thermogravimetrischen Analyse nach relativ

  5. Investigations of co-combustion of plastics in a coal dust furnace; Untersuchungen zur Mitverbrennung von Kunststoffen in einer Kohlestaubfeuerung

    Energy Technology Data Exchange (ETDEWEB)

    Gerhardt, T; Spliethoff, H; Hein, K R.G. [Stuttgart Univ. (Germany). Inst. fuer Verfahrenstechnik und Dampfkesselwesen (IVD); Christill, M; Kicherer, A; Seifert, H [BASF AG, Verfahrenstechnik-ZET/EH-L544, Ludwigshafen am Rhein (Germany)

    1997-12-31

    In a cooperation project of the Institute of Process Engineering and Power Plant TEchnology (IVD) at the University of Stuttgart and the BASF AG, investigations of co-combustion of plastic material in a coal dust furnace were carried out. The central question of the research work was the ignition and burnout of the particles in dependence of the residence time in the hot part of the furnace. Particle sizes were varied with the aim to define the largest possible particle size in order to minimize the cost of fuel preparation by grinding. On the other hand, tests were made with pure materials and synthetic mixtures of these in order to characterize the influence of different types of plastic. The investigations showed that plastics are suited as fuels for coal dust furnaces, and that the cost of fuel preparation can be reduced to an acceptable level. With polyethylene, which is difficult to ignite, an upper particle size limit of 1.25 to 1.5 mm was reached in the IVD test stand. In industrial applications with a different burner arrangement, even better results may be expected. (orig/AKB) [Deutsch] In einer Zusammenarbeit zwischen dem Institut fuer Verfahrenstechnik und Dampfkesselwesen (IVD) der Universitaet Stuttgart und der BASF AG wurden Versuche zur Coverbrennung von Kunststoffen in einer Kohlenstaubfeuerung durchgefuehrt. Im Mittelpunkt der Untersuchungen standen Zuendung und Abbrand der Kunststoffpartikel in Abhaengigkeit von der Verweilzeit im heissen Bereich der Brennkanner. Variiert wurden hierzu zum einen die Partikelgroessen mit dem Ziel, den Aufbereitungsaufwand durch Zerkleinerung zu minimieren. Zur Charakterisierung der Einfluesse verschiedener Kunststoffarten wurden die Versuche mit unterschiedlichen Reinkunststoffen und synthetischen Mischungen durchgefuehrt. Die Versuche zeigen, dass sich Kunststoffe mit vertretbarem Mahlaufwand in der Staubfeuerung einsetzen lassen. Am Beispiel des Polyethylen, eines der thermogravimetrischen Analyse nach relativ

  6. MRI of the hyaline knee joint cartilage. Animal experimental and clinical studies; MRT des hyalinen Kniegelenkknorpels. Tierexperimentelle und klinische Untersuchungen

    Energy Technology Data Exchange (ETDEWEB)

    Adam, G. [Technische Hochschule Aachen (Germany). Klinik fuer Radiologische Diagnostik; Prescher, A. [Technische Hochschule Aachen (Germany). Inst. fuer Anatomie; Nolte-Ernsting, C. [Technische Hochschule Aachen (Germany). Klinik fuer Radiologische Diagnostik; Buehne, M. [Technische Hochschule Aachen (Germany). Klinik fuer Radiologische Diagnostik; Scherer, K. [Technische Hochschule Aachen (Germany). Inst. fuer Versuchstierkunde; Kuepper, W. [Technische Hochschule Aachen (Germany). Inst. fuer Versuchstierkunde; Guenther, R.W. [Technische Hochschule Aachen (Germany). Klinik fuer Radiologische Diagnostik

    1994-02-01

    The value of MR imaging for the detection of hyaline cartilage lesions using 2-D spin-echo and 3-D gradient-echo imaging was evaluated in an animal experiment in 10 dogs and in a clinical study in 30 patients. MR imaging findings were compared with histopathological and arthroscopy findings, respectively. Using MRI neither grade I nor grade II hyaline cartilage lesions were detectable. In the animal experiments 77% of grade III lesions and all the grade IV lesions were seen. However, in the clinical study only about the half of grade III and IV lesions were detected. 3-D gradient-echo MR imaging was superior to 2-D spin-echo imaging (p<0.001), while 3-D FLASH and 3-D FISP did not differ significantly in the detection rate (p<0.34). 3-D gradient-echo MR imaging seems to be the best method for the delineation of high grade cartilage lesions. However, early stages of cartilage degeneration are invisible even with this imaging modality. (orig.) [Deutsch] Die Wertigkeit der MRT in der Erfassung von Knorpellaesionen mit 2-D-Spin-Echo- und 3-D-Grafienten-Echo-Sequenzen wurde in einer tierexperimentellen Untersuchung an 10 Hunden sowie in einer klinischen Studie an 30 Patienten ueberprueft. Die kernspintomographischen Ergebnisse wurden mit dem pathologisch-anatomischen Befund bzw. der Arthroskopie verglichen. MR-tomographisch konnten weder Grad-I- noch Grad-II-Knorpellaesionen erfasst werden. Die Erkennbarkeitsrate der Grad-III- und -IV-Laesionen lag fuer die tierexperimentellen Untersuchungen bei 77 bzw. 100%, waehrend klinisch nur etwa 50% dieser Veraenderungen erkannt werden konnten. Dabei waren die 3-D-Gradienten-Echo-Sequenzen den 2-D-Spin-Echo-Sequenzen signifikant ueberlegen (p<0,001), waehrend sich die 3-D-Gradienten-Echo-Sequenzen FISP und FLASH nicht voneinander unterschieden (p<0,34). Derzeit muessen die 3-D-Gradienten-Echo-Sequenzen als die beste Methode zur Erfassung hoehergradiger Knorpellaesionen angesehen werden. Fruehe Stadien der Knorpelschaedigung sind

  7. Biometrische Untersuchungen des Stylopodiums, Zygopodiums und Metapodiums pleistozäner Ursiden im Hinblick auf die Evolution des Höhlenbären und die Klassifizierung des Fundmaterials Einhornhöhle / Harz

    OpenAIRE

    Athen, Kerstin Anja

    2007-01-01

    In der vorliegenden Dissertation "Biometrische Untersuchungen des Stylopodiums, Zygopodiums und Metapodiums pleistozäner Ursiden im Hinblick auf die Evolution des Höhlenbären und die Klassifizierung des Fundmaterials Einhornhöhle / Harz" wurden Daten des oberpliozänen Ursus etruscus, des pleistozänen Ursus deningeri sowie des Ursus spelaeus ausgewertet. Zur Datenerhebung wurden 249 Messgrößen an den Skelettelementen Humerus, Ulna, Radius, Metacarpalia I-V, Femur, Tibia, Fibula und Metatarsali...

  8. Investigations for assessing the health hazards of dichloromethane exposure. Final report; Untersuchungen zur Abschaetzung des gesundheitlichen Risikos infolge Dichlormethanexposition. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Pankow, D. [Halle-Wittenberg Univ., Halle (Germany). Inst. fuer Pharmakologie und Toxikologie

    1994-04-01

    The oxidative CYP2E1-catalyzed dechlorination of dichloremethane (DCM) is a saturable pathway with high affinity and low capacity. In general, due to increasing DCM concentration in the inhaled air COHb values up to 12% are expected, but higher COHb levels were found according to some case reports. It was the aim of this study to characterize the DCM-derived COHb formation and to test effects of DCM on the cardiovascular system using animal models. The results show that a high CYP2E1 activity correlates with enhanced COHb formation. The COHb formation is inhibited and the DCM level in the blood enhanced after simultaneous exposure to DCM and solvents or drugs known as substrates of CYP2E1. Therefore, the risk assessment of DCM exposure must comprimise a possible additional uptake of a substrate or inducer of CYP2E1. Existing PBPK models proved to be an insufficient description in cases of an accidental scenario, a short exposure to very high concentration of DCM. The moderate CO hypoxia following DCM exposure is determined not only by the carboxyhemoglobinemia but also by an inhibition of cytochrome c oxidase activity. Cardiovascular dysfunctions, mainly arrhythmias, are detectable after exposure to relatively high DCM concentration as well as under pathophysiological conditions which per se influenced the cardiovascular system. (orig.) [Deutsch] Die zu CO fuehrende oxydative, CYP2E1-katalysierte Dechlorierung von Dichlormethan (DCM) verfuegt ueber eine hohe Affinitaet bei begrenzter Kapazitaet, es handelt sich um einen saettigbaren Stoffwechselweg. Im allgemeinen werden trotz steigender DCM-Konzentration in der eingeatmeten Luft Werte von 10-12% COHb nicht ueberschritten. Vergiftungsfaelle mit weitaus hoeheren COHb-Spiegeln wurden aber beschrieben. Ziel der tierexperimentellen Untersuchungen war es, die DCM-bedingte COHb-Bildung naeher zu charakterisieren und die Wirkung von DCM auf kardiovaskulaere Funktionen zu pruefen. Die Resultate zeigen, dass es bei

  9. Geochemical investigations into the retention of reactive carbon compounds for toxic heavy metals. Final report; Geochemische Untersuchungen zur Retention von reaktiven Kohlenstoffverbindungen fuer toxische Schwermetalle. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Kupsch, H.; Mansel, A.; Crustewitz, C.

    2003-03-01

    The composition, reactivity and stability of reactive organic carbon compounds adsorbed on geogenic matrices was investigated. The surface deposits of NOM and its dependence on geochemical parameters was investigated in selected geomatrices. The retention of toxic heavy metals on these surface deposits of NOM was investigated in consideration of the presence of hydroxy species and inorganic ligands. The investigations of the reactivity of the NOM species requires analyses of these compounds and of the heavy metals in the ultratracer region. This was possible by means of radiochemical methods that were further developed in the context of this project. Radioactive labeling of identified reactive carbon compounds, e.g. with radioactive iodine, on the one hand, and the use of radioactive Cu, Pb, Hg isotopes on the other hand enabled speciation analyses in the binary systems (heavy metal + geomatrix, heavy metal + reactive carbon compounds, reactive carbon compounds + geomatrix) and especially in the ternary system (heavy metal + geomatrix + reactive carbon compounds) in defined conditions. The special labelling techniques were a precondition for distribution measurements in the near-natural, low concentration range. (orig.) [German] Ziel des Projektes war es, mit der vorhandenen Analytik und Expertise die Zusammensetzung, die Reaktivitaet und die Stabilitaet der auf den geogenen Matrizes sorbierten reaktiven organischen Kohlenstoffverbindungen und die damit verbundenen Stoffumsaetze aufzuklaeren. An ausgewaehlten Geomatrizes wurde die Ausbildung von Oberflaechendepositen des NOM und deren Abhaengigkeit gegenueber geochemischen Parametern untersucht. Unter der Beruecksichtigung der Gegenwart von Hydroxyspezies und anorganischen Liganden wurde die Retention toxischer Schwermetalle an diesen Oberflaechendepositen des NOM untersucht. Die Untersuchungen zur Reaktivitaet der NOM-Spezies setzt eine Analytik dieser Verbindungen und der Schwermetalle im Ultraspurenbereich

  10. Possibilities for exposure reduction in computed tomography examination of acute chest pain; Moeglichkeiten der Dosisreduktion bei CT-Untersuchungen des akuten Thoraxschmerzes

    Energy Technology Data Exchange (ETDEWEB)

    Becker, H.C. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Campus Grosshadern, Institut fuer Klinische Radiologie, Muenchen (Germany)

    2012-10-15

    Electrocardiogram-gated (ECG) computed tomography (CT) investigations can be accompanied by high amounts of radiation exposure. This is particularly true for the investigation of patients with unclear and acute chest pain. The common approach in patients with acute chest pain is standard spiral CT of the chest. The chest pain or triple-rule-out CT protocol is a relatively new ECG-gated protocol of the entire chest. This article reviews and discusses different techniques for the CT investigation of patients with acute chest pain. By applying the appropriate scan technique, the radiation exposure for an ECG-gated protocol must not necessarily be higher than a standard chest CT scan Aortic pathologies are far better depicted by ECG-gated scan protocols and depending on the heart rate coronary artery disease can also be detected at the same time. The use of ECG-triggered scans will not support the diagnostics of the pulmonary arteries. However, in unspecific chest pain an ECG-triggered scan protocol can provide information on the differential diagnosis. (orig.) [German] EKG-getriggerte CT-Untersuchungen koennen mit einer relativ hohen Strahlenexposition einhergehen. Dies gilt im besonderen Masse fuer die Untersuchung des gesamten Thorax bei Patienten mit unklarem akutem Thoraxschmerz. Bisher wurden Untersuchungen bei Patienten mit akutem Thoraxschmerz in Spiraltechnik ohne EKG-Triggerung durchgefuehrt. Das ''Chest-pain-'' oder ''Triple-rule-out''-Protokoll ist ein neues EKG-getriggertes Untersuchungsprotokoll des gesamten Thorax. Im vorliegenden Artikel werden verschiedene Techniken zur CT-Untersuchung von Patienten mit akutem Thoraxschmerz vorgestellt und besprochen. Mit der richtigen Untersuchungstechnik muss die Strahlenexposition fuer ein EKG-getriggertes Untersuchungsprotokoll nicht hoeher sein als eine Standarduntersuchung ohne EKG. Mit einem EKG-getriggerten Untersuchungsprotokoll laesst sich die Aorta in Hinblick auf

  11. Electron microscopy and phase analysis of biofilms of bacterial cultures from hydrogeothermal water; Elektronenmikroskopische und phasenanalytische Untersuchungen an Biofilm von Bakterienkulturen aus geothermisch genutzten Tiefenwaessern

    Energy Technology Data Exchange (ETDEWEB)

    Koehler, M; Voelsgen, F; Bochning, S [URST Umwelt- und Rohstoff-Technologie, Greifswald (Germany); Kasbohm, J [Greifswald Univ. (Germany). FR Geowissenschaften

    1997-12-01

    In the context of a BMBF-funded project (1994 - 1996), concentrations and behaviour of microorganisms in hydrogeothermal water in Mecklenburg-Vorpommern were investigated. About 50 bacterial strains were isolated and characterized with respect to their cell morphology and relevant physiological properties. A relationship was found between bacterial cells and precipitation products. However, the methods of investigation could not differentiate between biogenic (biochemical) and chemical precipitation products, although the bacterial activity seems to be correlated with the precipitation of organic material. (orig.) [Deutsch] Im Rahmen eines vom BMBF geforderten Projektes (1994 - 1996) wurde das Vorkommen und Verhalten von Mikroorganismen in geothermisch genutzen Tiefenwaessern Mecklenburg-Vorpommerns untersucht. Bisher wurden ca. 50 Bakterienstaemme isoliert und hinsichtlich Zellmorphologie sowie relevanter physiologischer Eigenschaften charakterisiert. Mit den durchgefuehrten Untersuchungen konnte eine unmittelbare Beziehung zwischen Bakterienzellen und Faellungsprodukten nachgewiesen werden. Anhand der verwendeten Untersuchungsmethoden ist jedoch eine eindeutige Differenzierung zwischen biogenen (biochemischen) und rein chemischen Faellungsprodukten nicht moeglich. Offenbar bestehen aber eindeutige Beziehungen zwischen Bakterientaetigkeit und der Ausfaellung organischen Materials. (orig.)

  12. Mineralogical investigations of the role of the clay fraction in geothermal energy use; Mineralogische Untersuchungen zur Rolle der Tonfraktion bei der Gewinnung geothermischer Energie

    Energy Technology Data Exchange (ETDEWEB)

    Althaus, E; Frosch, G [Karlsruhe Univ. (T.H.) (Germany). Mineralogisches Inst.

    1997-12-01

    Authigenic clay minerals strongly influence the quality of geothermal reservoir systems. Their precipitation may drastically change the properties of reservoir sandstones. They interact more strongly with non-equilibrium fluids than most other mineral phases. The most abundant clay minerals in geothermal wells of Northeastern Germany are kaolinite, illite and mixed-layer minerals. Experiments are being carried out to study the dissolution rates of these minerals in NaCl brines at different pH-values. (orig.) [Deutsch] Im Rahmen des BMBF-Projektes `Evaluierung geowissenschaftlicher und wirtschaftlicher Bedingungen fuer die Nutzung hydrogeothermaler Ressourcen` werden am Mineralogischen Institut der Universitaet Karlsruhe (T.H.) Experimente zur Stabilitaet von Tonmineralen in geothermischen Systemen durchgefuehrt. Die Untersuchungen beziehen sich auf Gesteine und Solen, wie sie durch die nordostdeutschen Geothermiebohrungen Neustadt-Glewe, Rheinsberg und Neubrandenburg aufgeschlossen sind. Die Untersuchten Gesteinsproben enstammen der oberen Trias und dem Jura. Die vergleichbaren stratigraphischen Einheiten sind in den Bohrungen in unterschiedlicher Teufe und Maechtigkeit anzutreffen: So finden sich die Contorta-Schichten (Raetkeuper) bei Neustadt-Glewe in ca. 2200 m, bei Rheinsberg in ca. 1680 m und bei Neubrandenburg in ca. 1250 m Tiefe. (orig.)

  13. Investigation of the warm prestress effect by X-ray and microfractographic measurements; Roentgenografische und mikrofraktografische Untersuchungen zum Warmvorbeanspruchungs (WPS) - Effekt

    Energy Technology Data Exchange (ETDEWEB)

    Blumenauer, H.; Eichler, B.; Krempe, M.; Ude, J. [Magdeburg Univ. (Germany). Inst. fuer Werkstofftechnik und Werkstoffpruefung

    1998-11-01

    The work reported was to investigate the changes caused at the crack tip of a specimen with incipient crack and to assess their effects with regard to component fracture. The steels selected for testing are the pressure vessel steels 10MnMoNi5-5 and 17MoV8-4, and the experiments were made with CT-25 specimens. The conclusion drawn from the results obtained is that the WPS effect is due to a stronger energy dissipation in the prestressed area ahead of the crack tip, assisted by intrinsic stress-induced crack closing. (orig./CB) [Deutsch] Das Ziel dieser Arbeit ist es, die durch eine Vorbeanspruchung angerissener Proben hervorgerufenen Veraenderungen an der Rissspitze und ihre Auswirkungen auf das Bruchverhalten zu untersuchen. Die Untersuchungen wurden an den Druckbehaelterstaehlen 10MnMoNi5-5 und 17MoV8-4 durchgefuehrt. Die Versuche wurden an CT-25-Proben durchgefuehrt. Die Autoren kommen zum Schluss, dass der WPS-Effekt mit einer staerkeren Energiedissipation in der vorgeschaedigten Prozesszone vor der Rissspitze, unterstuetzt durch eigenspannungsbedingtes Rissschliessen, erklaert werden kann. (orig./MM)

  14. Working memory in volunteers and schizophrenics using BOLD fMRI; Das Arbeitsgedaechtnis bei Gesunden und bei Schizophrenen: Untersuchungen mit BOLD-fMRT

    Energy Technology Data Exchange (ETDEWEB)

    Giesel, F.L. [Deutsches Krebsforschungszentrum (DKFZ) Heidelberg, Abteilung Radiologie (Germany); Deutsches Krebsforschungszentrum (DKFZ), Abteilung Radiologie, Heidelberg (Germany); Hohmann, N. [Deutsches Krebsforschungszentrum (DKFZ) Heidelberg, Abteilung Radiologie (Germany); Psychiatrische Universitaetsklinik Heidelberg, Sektion Gerontopsychiatrie (Germany); Seidl, U.; Kress, K.R.; Schoenknecht, P.; Schroeder, J. [Psychiatrische Universitaetsklinik Heidelberg, Sektion Gerontopsychiatrie (Germany); Kauczor, H.-U.; Essig, M. [Deutsches Krebsforschungszentrum (DKFZ) Heidelberg, Abteilung Radiologie (Germany)

    2005-02-01

    Functional magnetic resonance imaging uses the blood oxygen level-dependent effect (BOLD MRI) for noninvasive display of cerebral correlatives of cognitive function. The importance for the understanding of physiological and pathological processes is demonstrated by investigations of working memory in schizophrenics and healthy controls. Working memory is involved in processing rather than storage of information and therefore is linked to complex processes such as learning and problem solving. In schizophrenic psychosis, these functions are clearly restricted. Training effects in the working memory task follow an inverse U-shape function, suggesting that cerebral activation reaches a peak before economics of the brain find a more efficient method and activation decreases. (orig.) [German] Die funktionelle Magnetresonanztomographie (fMRT) nutzt den ''blood oxygen level dependent effect'' (BOLD-Effekt) zur nichtinvasiven Darstellung zerebraler Korrelate kognitiver Funktionen. Die Bedeutung dieses Verfahrens fuer das Verstaendnis physiologischer und pathologischer Prozesse wird anhand von Untersuchungen zum Arbeitsgedaechtnis bei Schizophrenen und gesunden Kontrollpersonen verdeutlicht. Das Arbeitsgedaechtnis dient weniger der Speicherung, sondern vielmehr der Verarbeitung von Informationen und ist deshalb in komplexe Prozesse wie Lernen und Problemloesen eingebunden. Im Rahmen schizophrener Psychosen kommt es zu einer deutlichen Einschraenkung dieser Funktionen. Erwartungsgemaess zeigen sich unter Durchfuehrung eines Arbeitsgedaechtnisparadigmas Unterschiede in der zerebralen Aktivitaet, die jedoch bei den Erkrankten unter Therapie prinzipiell reversibel sind. Von Interesse sind auch Trainingseffekte bei Gesunden, wobei eine verminderte Aktivierung nach Training auf eine ''Oekonomisierung'' schliessen laesst. (orig.)

  15. Alexandru Popa, Untersuchungen zu den römisch-barbarischen Kontakten Östlich der römischen Provinz Dacia Antiquitatis reihe 3 Abhnadlungen zur vor-und frühgeschichte, zur klassichen und provinzial-römischen archäologie und zur geschichte des altertum

    Directory of Open Access Journals (Sweden)

    Vasile Iarmulschi

    2016-06-01

    Full Text Available Review on book - Alexandru Popa, Untersuchungen zu den römisch-barbarischen Kontakten Östlich der römischen Provinz Dacia Antiquitatis reihe 3 Abhnadlungen zur vor-und frühgeschichte, zur klassichen und provinzial-römischen archäologie und zur geschichte des altertum

  16. DRUCKFLAMM - Investigation on combustion and hot gas cleanup in pulverized coal combustion systems. Final report; DRUCKFLAMM - Untersuchungen zur Verbrennung und Heissgasreinigung bei der Druckkohlenstaubfeuerung. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Hein, K.R.G.; Benoehr, A.; Schuermann, H.; Stroehle, J.; Klaiber, C.; Kuhn, R.; Maier, J.; Schnell, U.; Unterberger, S.

    2001-07-01

    facility of the Technical University of Aachen. (orig.) [German] Die Bestrebungen einer effizienten und schadstoffarmen Energieversorgung fuehrten bei der Kohleverbrennung zur Entwicklung von kohlebasierten Kombikraftwerken, die im Vergleich zum konventionellen Kondensationskraftwerk eine deutliche Anhebung des Nettowirkungsgrades erlauben. Eines der Kombikraftwerkskonzepte auf Kohlebasis stellt die Druckkohlenstaubfeuerung dar, die gegenueber den anderen Konzepten das hoechste Wirkungsgradpotential aufweist. Das Ziel dieses Forschungsvorhabens war die Gewinnung gesicherter Erkenntnisse hinsichtlich des Feuerungsverhaltens von Kohle in einer Druckkohlenstaubfeuerung. Es wurden an einem Druckflugstromreaktor detaillierte Untersuchungen zur Brennstoffumsetzung und zum Partikelverhalten, zur Schadstoffbildung und zum Werkstoffverhalten unter Bedingungen der Druckkohlenstaubfeuerung durchgefuehrt. Im Laufe des Forschungsvorhabens wurden einige neue Messtechniken eingesetzt und teilweise auch angeschafft, wie zum Beispiel ein Zwei- Farb-Pyrometer zur simultanen Erfassung von Partikeloberflaechentemperatur und Partikeldurchmesser von brennenden Brennstoffpartikeln. Parallel zu den experimentellen Untersuchungen wurde an der Erarbeitung neuer Berechnungsmodelle gearbeitet, um eine spaetere Feuerraumsimulation fuer ein verbessertes Scale-Up zu ermoeglichen. Die am Druckflugstromreaktor gewonnenen Ergebnisse zeigen, dass der erhoehte Systemdruck sich auf sehr viele Verbrennungsmechanismen stark auswirkt, so konnte eine schnellere Brennstoffumsetzung und gleichzeitig verminderte Stickoxid- und Alkaligasemission nachgewiesen werden. Die Werkstoffuntersuchungen zeigten, dass die aufgrund der sehr hohen Verbrennungstemperaturen benoetigten Keramikwerkstoffe sehr empfindlich gegenueber Verschlackung und schnellen Temperaturwechseln sind, weshalb hinsichtlich der benoetigten Standzeiten in einer zu realisierenden Druckbrennkammer noch erheblicher Entwicklungsbedarf besteht. Hinsichtlich

  17. Numerical investigations on the influence of wind shear and turbulence on aircraft trailing vortices; Numerische Untersuchungen zum Einfluss von Windscherung und Turbulenz auf Flugzeugwirbelschleppen

    Energy Technology Data Exchange (ETDEWEB)

    Hofbauer, T.

    2003-07-01

    In several aspects, the behaviour of aircraft wake vortices under situations of vertical wind shear is significantly different from non-shear scenarios and its operational real-time forcast is challenging. By means of numerical investigations of idealized scenarios, the influence of wind shear on the lateral and vertical transport of vortices is analysed both, phenomenologically as well as in the scope of a sensitivity study. The results allow for the verification of controversial views and the benchmark of modelling approaches. Case studies of turbulent shear flows focus on the persistence of vortices. A detailed analysis of the flow fields evidence that unequal vortex decay rates can be attributed to the asymmetric distribution of secondary vorticity structures. The results moreover suggest that extended vortex lifespans can be expected under situations of wind shear. The unusual vortex behaviour observed by means of a LIDAR measurement is reproduced by realistic simulations and permits to reveal potential causes. (orig.) [German] Das Wirbelschleppenverhalten unterscheidet sich in Situationen vertikaler Windscherung in mehrfacher Hinsicht signifikant von scherungsfreien Szenarien und stellt eine besondere Herausforderung fuer eine operationelle Echtzeitvorhersage dar. Mittels numerischer Untersuchungen idealisierter Szenarien wird zunaechst der Einfluss von Windscherung auf den lateralen und vertikalen Wirbeltransport sowohl phaenomenologisch als auch quantitativ im Rahmen einer Sensitivitaetsstudie analysiert. Anhand der gewonnenen Ergebnisse werden auseinandergehende Erklaerungsansaetze geprueft und Modellierungsansaetze bewertet. Fallstudien turbulenter Scherstroemungen zur Wirbelpersistenz stellen einen weiteren Schwerpunkt dieser Arbeit dar. Durch die ausfuehrliche Analyse der Stroemungsfelder wird der Nachweis erbracht, dass sich unterschiedliche Zerfallsraten der Wirbel auf die asymmetrische Verteilung von sekundaeren Vorticity-Strukturen zurueckfuehren

  18. Studies on the microbial sulphur cycle in acid ponds in the Niederlausitz mining region in Brandenburg; Untersuchungen zum mikrobiellen Schwefelkreislauf in sauren Tagebau-Restseen der Niederlausitz (Brandenburg)

    Energy Technology Data Exchange (ETDEWEB)

    Meier, J

    2001-07-01

    The water quality of the acid ponds in the Niederlausitz brown coal mining region is characterised by pH values below 3 and high concentrations of dissolved iron (up to 10 mM) and sulphate (up to 30 mM). The development of these ponds is determined by the equilibrium that arises between acidifying and alkalinising processes. Acidity develops through weathering and oxidation of iron sulphides in the mining refuse, whereas alkalinity arises through the reduction of iron (III) and sulphate in the pond sediments, a process associated with the oxidation of organic matter. The purpose of the present study was to examine the influence of sulphate reduction and sulphur oxidation on the neutralising potential of the sediments in acid ponds and to characterise and identify the microorganisms involved in these processes. Comparative explorations were performed in two acid waters, namely ponds 111 and 107, and in a neutral water, namely pond B, in a semi-natural area of the Niederlausitz region. [German] Die Wasserqualitaet der sauren Bergbau-Restseen im Braunkohlerevier der Niederlausitz ist durch pH-Werte unter pH 3 und hohe Konzentrationen an geloestem Eisen (bis zu 10 mM) und Sulfat (bis zu 30 mM) gekennzeichnet. Die Entwicklung der Restseen wird durch das Gleichgewicht von aziditaets- und alkalinitaetsbildenden Prozessen bestimmt. Aziditaet entsteht bei der Verwitterung bzw. der Oxidation der Eisensulfide im Kippmassiv, waehrend Alkalinitaet bei der an die Oxidation organischer Substanz gekoppelte Reduktion von Eisen(III) und Sulfat in den Sedimenten der Seen gebildet wird. In der vorliegenden Arbeit wurde der Einfluss der Sulfratreduktion und der Schwefeloxidation auf das Neutralisierungspotenzial der Sedimente der sauren Restseen untersucht sowie die an diesen Prozessen beteiligten Mikroorganismen charakterisiert und identifiziert. Vergleichende Untersuchungen wurden in zwei sauren, Restsee 111 und 107, und in einem neutralen Gewaesser, Restsee B, im naturnahen Bereich

  19. Air quality III - experiments on emission and sensory perception of olfactory substances from ventilation systems. Final report; Luftqualitaet III - Experimentelle Untersuchungen zur Emission und Wahrnehmung von Geruchsstoffen aus Lueftungsgeraeten. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Fitzner, K.; Boettcher, O.

    2001-08-01

    Room air quality is highly important in Germany as people living here will spend 90 percent of their lives inside rooms. Air quality is defined to a large extent via the nose. This research project, in continuation of AiF 10525, involved investigations of materials and components of space HVAC systems with varying air temperatures, humidities and air flow rates for a subjective assessment of the air quality. The main goals were the definition of laws for identification of odorants and the derivation of laws for calculating pollutant-level-dependent ambient air rates for mechanically ventilated rooms. The experiments showed that both adsorption and desorption had a significant part in the addition of odorangs, causing deviations between theoretical and experimental values of felt air quality. The temperature and the relative humidity had an effect as well. Most measurements were made near the olfactory threshold, so that a number of participants were unable to complete the test. Later investigations will rely on analytical methods in addition to test persons. (orig.) [German] Das Thema der Luftqualitaet in Innenraeumen hat in Deutschland grosse Bedeutung, da sich die Bevoelkerung zu 90 Prozent ihres Lebens in Innenraeumen aufhaelt. Die Behaglichkeit der Atemluft wird in grossem Masse durch die mit der Nase wahrgenommenen Bestandteile der Luft beeinflusst. In Fortsetzung zum Forschungsvorhaben AiF 10525 wurden in diesem Forschungsvorhaben Untersuchungen mit Materialien und Komponenten aus RLT-Anlagen unter Veraenderung von Lufttemperatur, Luftfeuchte und Luftgeschwindigkeit zur subjektiven Beurteilung der Luftqualitaet durchgefuehrt. Die Hauptziele dieser Untersuchungen waren das Auffinden der Gesetzmaessigkeiten zur Wahrnehmung von Geruchsstoffen und das Ableiten von Rechenregeln zur Bestimmung verunreinigungslastabhaengiger Aussenluftraten fuer maschinell belueftete Raeume. Die Versuche zeigten, dass Adsorption und Desorption bei der Addition von Geruchsstoffen

  20. Experimental investigations on inlet flow of ducted turbines. A contribution to turbine intake optimization; Experimentelle Untersuchungen zur Anstroemung von Rohrturbinen. Ein Beitrag zur Optimierung des Turbineneinlaufes

    Energy Technology Data Exchange (ETDEWEB)

    Godde, D. [Technische Univ. Muenchen, Obernach (Germany). Versuchsanstalt fuer Wasserbau und Wasserwirtschaft (Oskar-von-Miller-Institut)

    1994-12-31

    erfuellen, die in allgemeiner Form auch in zahlreichen Veroeffentlichungen formuliert sind. Im Rahmen der vorliegenden Arbeit konzentrieren sich die neuen Untersuchungen auf diesem Gebiet - an einem Modell und an einem Versuchskraftwerk - auf den Trennpfeiler, den Rechen und die anschliessende Verziehung im Einlaufbereich von Rohrturbinen. Die Untersuchungsergebnisse klaeren nun einige Zusammenhaenge, widersprechen teilweise bisherigen Annahmen oder bestaetigen sie und relativieren manche der Anforderungen. Die Ergebnisse sind zwar unter Beachtung der modelleigenen Restriktionen und der Charakteristik der verwendeten Turbine zu werten, besitzen jedoch auf Grund des Untersuchungsumfangs bis zu einem gewissen Grad Allgemeingueltigkeit. (AKF)

  1. Investigations on the chemical composition of the organic fraction of tropospheric aerosols. Final report; Untersuchungen zur chemischen Zusammensetzung der organischen Komponente des troposphaerischen Aerosols. AFS-Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, T.; Warscheid, B.

    2000-07-01

    ] Obwohl das Wissen um die Bedeutung von luftgetragenen Partikeln fuer die Strahlungsbilanz der Atmosphaere in den letzten Jahren zugenommen hat, sind eine Reihe von wichtigen Aerosolbildungsmechanismen bisher nur unzureichend untersucht worden. Dies gilt insbesondere fuer Aerosole, die aus fluechtigen organischen Vorlaeufern natuerlichen wie auch antrophogenen Ursprungs im Verlauf von troposphaerischen Oxidationsprozessen gebildet werden. Das Vorhaben umfasste daher die Entwicklung massenspektrometrischer Methoden fuer qualitative wie auch fuer quantitative Studien zur chemischen Zusammensetzung von sekundaeren organischen Aerosolen (SOA), insbesondere gebildet aus der Ozonolyse von Monoterpenen (z.B. {alpha}-Pinen, {beta}-Pinen, Sabinen, {delta}{sup 3}-Caren, Limonen). Mit Hilfe eines entwickelten On-line APCI-ITMS-Systems (atmospheric pressure chemical ionisation, APCI) konnte die Bildung von Gas- und Partikelphasenprodukten in Echtzeit (Zeitaufloesung {proportional_to}1 s) als Folge der Monoterpen-Ozonolyse beobachtet werden. Die Nachweisgrenze der Methode liegt bei ca. 100 ppt(v/v) im positiven Ionenmodus. Basierend auf der Entwicklung geeigneter Standardadditionsmethoden erfolgte auch die unmittelbare Quantifizierung ausgewaehlter Oxidationsprodukte in der Gas- und Partikelphase. Mittels isotopenmarkiertem Wasser (H{sub 2}{sup 18}O) wurden darueber hinaus einige zugrundeliegende Reaktionsmechanismen aufgedeckt. Ein weiterer Teil des Projektes konzentrierte sich auf die Charakterisierung insbesondere der schwerfluechtigen Aerosolkomponenten der Monoterpen-Ozonolyse mittels MS/MS-Studien. Diese Studien ergaben, dass eine Reihe von multifunktionellen Carbonsaeureprodukte signifikante Aerosolbestandteile repraesentieren (Dicarbonsaeuren, Oxocarbonsaeuren, Hydroxycarbonsaeuren etc.). Schliesslich ergaben die massenspektrometrischen Untersuchungen deutliche Hinweise auf starke intermolekulare Wechselwirkungen zwischen den einzelnen Produkten (Assoziatbildung). Da ausserdem

  2. Examination of the somatostatin receptor status in non-medullary thyroid cancer; Untersuchungen zum Somatostatinrezeptor-Status bei nicht-medullaeren Schilddruesenkarzinomen

    Energy Technology Data Exchange (ETDEWEB)

    Goerges, R.; Brandt-Mainz, K.; Bockisch, A. [Essen Univ. (Gesamthochschule) (Germany). Klinik und Poliklinik fuer Nuklearmedizin; Kahaly, G. [Mainz Univ. (Germany). Klinik und Poliklinik fuer Medizin - Endokrinologie und Stoffwechselerkrankungen; Mueller-Brand, J.; Maecke, H. [Kantonsspital Basel (Switzerland). Inst. fuer Nuklearmedizin; Walgenbach, S. [Mainz Univ. (Germany). Klinik und Poliklinik fuer Allgemein- und Abdominalchirurgie; Bruns, C. [Praeklinische Forschung Novartis, Basel (Switzerland); Andreas, J. [Universitaetsklinik Mainz (Germany). Klinik und Poliklinik fuer Nuklearmedizin

    1999-06-01

    Aim: Recent in-vitro and in-vivo studies demonstrated a somatostatin receptor expression in some non-medullary thyroid carcinomas. In this study we investigated the somatostatin receptor status for this particular tumor entity in a larger patient group. Subject and methods: We compared 131-iodine with 111-In-pentetreotide scans in 24 patients with metastasizing, non-medullary thyroid cancer. The findings were correlated with other imaging modalities. Additionally, we performed receptor autoradiography in one patient, octreotide therapy in another patient and administration of 90-Y- and 111-In-DOTATOC in 2 consecutive patients. Results: In the 15 patients with papillary or follicular carcinoma, 111-In-pentetreotide was inferior to 131-I in 8/15, equal in 1/15, and superior in 6/15 patients. In 8/9 of the patients with Huerthle cell cacinoma, metastases showed a 111-In-pentetreotide accumulation of various intensity, while 131-iodine scans were negative except for one patient. 111-In-pentetreotide was equal or superior compared to 201-Tl or 99m-Tc-sestamibi, but for the most part inferior in comparison with 18-F-FDG-PET. The findings of 111-In-pentetreotide scintigraphy correlated well with the receptor autoradiography and the accumulation of DOTATOC, but not with the therapeutic effect of `cold` octreotide on the thyroid cancer metastases. Conclusions: Several metastases of papillary and follicular carcinoma, and the majority of Huerthle cell cancer metastases can express somatostatin receptors. 111-In-pentetreotide scintigraphy is a promising tool for localization of metastases especially in Huerthle cell cancer or if PET is not available, and may be useful for selection of possible candidates, if therapeutic effective {beta}-emitting somatostatin analogues will be available for routine application. (orig.) [Deutsch] Ziel: in aktuellen In-vitro und In-vivo-Untersuchungen wurde eine Somatostatinrezeptor-Expression bei einigen nicht

  3. Untersuchungen zur Entwicklung von Satellitengalaxien

    Science.gov (United States)

    Seidel, Björn

    2002-01-01

    Gleichgewichtsmodelle ein- und zweikomponentiger Satellitengalaxien werden erzeugt und die Gezeiteneinwirkungen der als starres äußeres Potential angenommenen Milchstraße auf sie betrachtet. Eine erste Reihe von Simulationen mit anfänglich kugelsymmetrischen einkomponentigen Satelliten zeigt, daß sich nach elliptischer Deformation ein Balken und Schweife ungleicher Länge ausbilden, deren Aussehen sich periodisch ändert. Mithilfe von Vergleichssimulationen wurden folgende Phänomene am Satelliten entdeckt: (1) Hochdichtebereiche in den Schweifen, (2) Niedrigdichtebereiche um den Kern bzw. Balken und (3) ein oft verdeckter Balken. Analysiert wird das Erscheinungsbild in Zeitabhängigkeit. Die Teilchen gehen dem Kern über den Balken verloren und bewegen sich entlang gewisser stets gleich aussehender charakteristischer Strukturen in die Schweife. Nach einer Herleitung allgemeiner Größen des mehrkomponentigen Kingprofils werden drei stabile Standardmodelle zweikomponentiger Satellitengalaxien mit Massenverhältnis 1:10 (baryonische zu dunkle Materie) und unterschiedlicher Verteilung der dunklen und sichtbaren Materie gefunden. Ohne die Allgemeinheit der Ergebnisse zu beeinträchtigen, wurde dabei die Große Magellanische Wolke als Grundlage der Modelle genommen. Nach geeigneter Wahl der Bahn, zu der der Gezeitenradius des verwendeten dreikomponentigen Milchstraßenpotentials sowohl analytisch als auch numerisch berechnet wird, werden Simulationen der Modelle analysiert. Hauptaugenmerk ist das unterschiedliche Verhalten der Komponenten. Hauptergebnisse: (1) Es ist möglich, große Anteile dunkler, jedoch nur geringe sichtbarer Materie abzulösen. Dunkle und sichtbare Materie können unterschiedliche morphologische Strukturen bilden. (2) Je nach Konzentration der Komponenten ist die Eigengravitation der Teilchen mehr oder weniger für das Aussehen bestimmend. (3) Die Kernauflösung des Satelliten findet im Perigalaktikum (PG), sein Zerfall aber erst im Apogalaktikum statt. (4) Die Geschwindigkeitsdispersionen der Komponenten im Kern sind im PG entlang der Sichtlinie kurzzeitig stark erhöht, sie fallen ebenso wie die Dichten und deren Verhältnis mit jedem PG stufenförmig ab; einiges davon sind nur Projektionseffekte. (5) Der radiale Verlauf der Geschwindigkeitsdispersion ist vom Bahnort abhängig er wurde genau untersucht. (6) Der Satellit zerfällt über einen Kreislauf aus Massenverlust, flacher werdendem Potential und kleiner werdendem Gezeitenradius. Equilibrium models of one- and two-component satellite galaxies are created. The tidal influence of the Milky Way, which is modeled as a rigid external potential, is examined. A first set of simulations adopting originally spherically-symmetric, one-component satellites show that after elliptical deformation, a bar and tails of unequal length arise which change their morphology cyclically. By considering comparative simulations, the following phenomena are discovered: (1) High-density regions in the tails, (2) low-density zones around the core or bar, (3) an often concealed bar. The overall morphology as function of time is analysed. The particles are lost from the core via the bar and move along certain morphologically characteristic structures into the tails. After deducing general quantities of the multi-component King model, three stable standard models of two-component satellite galaxies with different distributions of dark and visible matter are found. These models have a mass ratio of 1:10 for baryonic to dark matter. Without restriction to the universality of the results, the Large Magellanic Cloud was taken as basic prototype for these models. To choose the proper orbits, the tidal radius of the three-component model of the potential of the Galaxy is calculated both analytically and numerically. Then the simulations are analysed with the different behaviour of the components being the main focus of interest. Main results: (1) It is possible to detach a large fraction of dark matter but only a small amount of visible matter. Dark and visible matter may form different morphological structures. (2) Depending on the concentrations of the components, self-gravity may be the decisive factor for determining the morphology. (3) The dissolution of the core of the satellite occurs at perigalacticon (PG), but it does not decay before apogalacticon. (4) At PG the core densities of the components, their ratio and the velocity dispersions fall off in steps, the velocity dispersions along the line of sight show a high narrow peak. Some of these effects are just projection effects. (5) The radial dependence of the velocity dispersion is dependent on the orbital position; it is analysed in detail. (6) The satellite decays through a cycle of mass loss, an increasingly shallow potential and decreasing tidal radius.

  4. Aquisition of age- and sex-dependent patient data for the calculation of annual radiation exposure in nuclear medicine: a German pilot study; Erfassung alters- und geschlechtsbezogener Daten nuklearmedizinischer Untersuchungen zur Berechnung der jaehrlichen Strahlenexposition in der BRD: Eine Pilotstudie

    Energy Technology Data Exchange (ETDEWEB)

    Schnell-Inderst, P.; Hacker, M.; Weiss, M.; Hahn, K. [Klinik und Poliklinik fuer Nuklearmedizin, Klinikum der Univ. Muenchen (Germany); Nosske, D.; Stamm-Meyer, A.; Brix, G. [Bundesamt fuer Strahlenschutz, Inst. fuer Strahlenhygiene, Neuherberg (Germany)

    2004-04-01

    Aim: a pilote study for estimation of radiation exposure due to diagnostic procedures in nuclear medicine using routine data of hospitals and practices in Germany. Methods: hospitals and practices willing to participate in the study supplied data of one year (1997), containing information on patients' identification number, age, sex, type of diagnostic procedure, radiopharmaceutical, administered activity, type of health insurance (private/public), inpatient/outpatient status, and so-called leistungsziffer, which describes the type of medical performances in Germany. The effective dose per examination was calculated according to ICRP 80. Mean, standard deviation, median, 5{sup th} and 95{sup th} percentiles of the effective dose were calculated, stratified by type of organ system and also by sex and age, including patients of {>=} 18 years. Results: 82 039 examinations from patients of 9 hospitals and practices were analyzed. The median (5-95{sup th} percentiles) of the effective dose per examination for all patients was 2.9 mSv (0.4-8.5 mSv); 1.2 examinations per patient and year were performed on average. The three most frequent examinations were bone scans (median 3.4 mSv; 2.9-5.1), thyroid (0.9 mSv; 0.4-2.2) and cardiovascular studies (7.3 mSv; 3.8-20.2). The median effective dose for 18 to 40 years old women was 1.0 mSv (0.4-5.8), for women between 41 and 65 years 2.2 mSv (0.4-7.3) and for women older than 65 years 2.4 mSv (0.5-7.6). The corresponding values for men were 2.6 mSv (0.3-7.6); 3.3 mSv (0.4-9.1), and 3.4 mSv (0.5-8.8). Conclusion: it was possible to gain an accurate determination of radiation exposure of diagnostic procedures in nuclear medicine by routine data. (orig.) [German] Ziel: Pilotstudie zur Ermittlung der Strahlenexposition in Deutschland bei Untersuchungen in der nuklearmedizinischen Diagnostik anhand von Routinedaten aus Kliniken und Praxen. Methoden: Kliniken und Praxen in Deutschland lieferten 1997 routinemaessig erhobene

  5. Theoretical and experimental investigations of an added firing system in cogeneration processes with gas turbines optimizing flame stability and burnout behaviour; Theoretische und experimentelle Untersuchungen einer Zusatzfeuerung in gasturbinengestuetzten KWK-Prozessen fuer eine Optimierung hinsichtlich Flammenstabilitaet und Ausbrandverhalten

    Energy Technology Data Exchange (ETDEWEB)

    Koesters, M.; Kliemt, C.

    2004-07-01

    The effects of the key flow, mixing and ignition parameters on the ignition process was investigated in near-practical conditions. It was found that the ignition energy can be minimized by careful selection of the electrode configuration and positioning near the burner. Further, a criterion was developed for developing characteristic fields and design specifications for gas burners. The FLUENT code can calculate the mixing, flow and turbulence situation of a burner. This, and plus the newly established ignition criterion, can support the development of characteristic fields and help to minimize the experimental expenditure. [German] Der Einfluss der wichtigsten Stroemungs-, Mischungs- und Zuendparameter auf die Zuendung wurde mit Hilfe gezielter experimenteller und theoretischer Untersuchungen unter industrienahen Bedingungen getestet. Hierbei konnte eine gute Uebereinstimmung zwischen den Messungen und Rechnungen erzielt werden. Die Ergebnisse haben gezeigt, dass durch eine geeignete Wahl der Elektrodenkonfiguration und der Elektrodenpositionierung im Brennernahbereich eine Zuendenergieminimierung erreicht werden kann. Gleichzeitig wurde ein Kriterium entwickelt, das zur Erarbeitung von Kennfeldern und Auslegungsvorschriften fuer Gasbrenner genutzt werden kann. Mit Hilfe des kommerziellen CFD-Programms FLUENT kann die Mischungs-, Stroemungs- und Turbulenzsituation eines Brenners numerisch berechnet werden. Mittels dieser Ergebnisse und unter Anwendung des ermittelten Zuendkriteriums kann die Erstellung von Arbeits- und Zuendkennfeldern fuer die Neuentwicklung bzw. Verbesserung von Industriegasbrennern unterstuetzt und somit der experimentelle Aufwand minimiert werden. (orig.)

  6. Towards isotope shift and hyperfine structure measurements of the element nobelium

    Energy Technology Data Exchange (ETDEWEB)

    Chhetri, Premaditya; Lautenschlaeger, Felix; Walther, Thomas [Institut fuer Angewandte Physik, TU Darmstadt, D-64289 Darmstadt (Germany); Laatiaoui, Mustapha [Helmholtz Institut Mainz, D-55099 Mainz (Germany); Block, Michael; Hessberger, Fritz-Peter [Helmholtz Institut Mainz, D-55099 Mainz (Germany); GSI, D-64291 Darmstadt (Germany); Lauth, Werner; Backe, Hartmut [Institut fuer Kernphysik, JGU Mainz, D-55122 Mainz (Germany); Kunz, Peter [TRIUMF, D-V6T2A3 Vancouver (Canada)

    2014-07-01

    Laser spectroscopy on the heaviest elements is of great interest as it allows the study of the evolution of relativistic effects on their atomic structure. In our experiment we exploit the Radiation Detected Resonance Ionization Spectroscopy technique and use excimer-laser pumped dye lasers to search for the first time the {sup 1}P{sub 1} level in {sup 254}No. Etalons will be used in the forthcoming experiments at GSI, Darmstadt, to narrow down the bandwidth of the dye lasers to 0.04 cm{sup -1}, for the determination of the isotope shift and hyperfine splitting of {sup 253,} {sup 255}No. In this talk results from preparatory hyperfine structure studies in nat. ytterbium and the perspectives for future experiments of the heaviest elements are discussed.

  7. Investigations of the metabolism of the hormones ethylen, abscisic acid and indol-3-acetic acid in coniferous trees in forest die-back areas of south western Germany; Untersuchungen zum Haushalt der Hormone Ethylen, Abscisinsaeure und Indol-3-essigsaeure in Nadelbaeumen aus Waldschadensgebieten Suedwestdeutschlands

    Energy Technology Data Exchange (ETDEWEB)

    Christmann, A.

    1993-12-31

    The author investigated changes in the hormone metabolism of affected trees; he intended to analyze as many hormones as possible. The investigations were carried out on needles, owing to the fact that the symptoms observed suggested specific disturbances of the needle hormone metabolism. Further, needles are the main point of attack of airborne pollutants. In physiologically healthy trees, the seasonal changes in hormone levels were investigated as a function of different parameters such as forest site, needle age, tree age, and position of sample branches in the tree crown. On this basis, hormone changes resulting from tree disease were characterized for the sample trees. SO{sub 2} and ozone were taken into account in the investigations. It was found that although the development with time of physiological and structural characteristics suggests premature aging of the needles of affected trees, the changes in the hormone metabolism do not correspond to the hormonal control patterns of natural needle aging. SO-2 exposure or a lack of minerals at the forest site are excluded as causes of the observed damage. No conclusive information could be obtained on the effects of ozone. (orig./MG) [Deutsch] Es war ein Ziel dieser Arbeit, nachzuweisen, welche Veraenderungen im Hormonhaushalt erkrankter Baeume vorliegen und dabei moeglichst viele Hormone zu bearbeiten. Die Untersuchungen wurden an Nadeln durchgefuehrt, da die beobachtbaren Symptome fuer eine Stoerung des Hormonhaushaltes vor allem dieser Organe sprachen und sie zudem Hauptangriffsort fuer Luftschadstoffe sind. An physiologisch gesunden Baeumen wurde das Verhalten der einzelnen Hormone im Jahresverlauf in Abhaengigkeit von verschiedenen Einflussgroessen wie Standort, Nadelalter, Baumalter und Position von Probenaesten innerhalb der Baumkrone erarbeitet. Danach wurden die krankheitsbedingten Veraenderungen im Hormonhaushalt der entsprechenden Versuchsbaeume charakterisiert. Die Schadgase SO{sub 2} und Ozon wurden

  8. Investigations on radionuclide release and on the corrosion behaviour of spent fuels from research reactors under disposal conditions. Final report; Untersuchungen zur Radionuklidfreisetzung und zum Korrosionsverhalten von bestrahltem Kernbrennstoff aus Forschungsreaktoren unter Endlagerbeedingungen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Bruecher, H.; Curtius, H.; Fachinger, J.; Kaiser, G.; Mazeina, L.; Nau, K.

    2003-12-01

    From the present report 'Untersuchungen zur Radionuklidfreisetzung und zum Korrosionsverhalten von bestrahltem Kernbrennstoff aus Forschungsreaktoren unter Endlagerbedingungen' with the code number FKZ 9108 carried out in the time periode 01.06.1998 till 30.11.2001 the following results can be withdrawn: U/Al-RR-fuel elements corroded slowly in granite water (Grimsel-West) at 90 C under anaerobic conditions. For a complete dissolution of the fuel element a time period of 10{sup 3} years is assumed according to present conservative results. In salt brines, especially in magnesium chloride rich brines the corrosion rate is high. Addition of GGG40 (basic material of the fuel element container with iron as main element) had an acceleration effect. A complete dissolution of the fuel is achieved within a couple of months. Under aerobic and under anaerobic conditions the bulk of released radionuclides were fixed by the corrosion products formed (secondary phases). The actinides were mobilised by variation of the ionic strength of the leaching solution. This process can be explained by phase conversion reactions within the secondary phases. Secondary phases formed by corrosion of a non-irradiated U/Al-RR-fuel element, were analysed and hydrotalcites were identified as phase components. This result justifies the assumption, that hydrotalcites are components of the corrosion products from irradiated fuels. To clarify the questions which bindings exist between radionuclides and secondary phases, sorption experiments were performed. The sorption experiments were performed in salt brines and in granite water using repository relevant radionuclides and minerals which are considered to represent thermodynamic final components of the secondary phases. Pu sorbed as cationic species quantitatively and the binding is covalent. In granite water the same behaviour was found for Am. (orig.) [German] Aus dem vorliegenden Bericht 'Untersuchungen zur Radionuklidfreisetzung

  9. Wind power project. Investigation of the habitat use of selected native small game species in the vicinity of wind power systems. Final report; Projekt Windkraftanlagen. Untersuchungen zur Raumnutzung ausgewaehlter heimischer Niederwildarten im Bereich von Windkraftanlagen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Pohlmeyer, K.; Menzel, C.

    2001-04-01

    Acting on behalf of the State Hunting Association of Lower Saxony the Game Research Institute (IWFo) of Hannover Veterinary University carried out a three-year study from April 1998 through March 2001 on the habitat use of selected native small game species in the vicinity of aerogenerators. This final report depicts the animals' preferred places, use of agricultural land, avoidance radius, if any, their activities and exposure to predator pressure. The target species were roe deer, hare, red fox, partridge and carrion crow. The study was carried out in Lower Saxony and Bremen on a total study area of 22.3 km{sup 2}, comprising four areas with running aerogenerators and five control areas without an aerogenerator. All parameters were studied in terms of a comparison between aerogenerator and control areas. The objective was to identify differences in population, use of space and habitat and in behaviour. [German] Am Institut fuer Wildtierforschung an der Tieraerztlichen Hochschule Hannover (IWFo) wurde im Auftrag der Landesjaegerschaft Niedersachsen (LJN) in einer dreijaehrigen Studie von April 1998 bis Maerz 2001 die Raumnutzung ausgewaehlter heimischer Niederwildarten im Bereich von Windkraftanlagen (WKA) untersucht. Im Weiteren wurden Aufenthaltspraeferenzen, Nutzung der landwirtschaftlichen Flaechen, moegliche Naeherungslimits und Aktivitaeten der Wildarten sowie der Beutegreiferdruck dargestellt. Zielarten der Studie waren Rehwild, Feldhase, Rotfuchs, Rebhuhn und Rabenkraehen. Die Untersuchungen wurden in vier Gebieten mit in Betrieb befindlichen WKA sowie in fuenf Referenzgebieten ohne WKA in Niedersachsen und Bremen auf einer Flaeche von insgesamt 22,3 km{sup 2} durchgefuehrt. Alle Parameter wurden vergleichend fuer die WKA- und Referenzgebiete betrachtet. Moegliche Unterschiede im Besatz bzw. Bestand, in Raum- und Habitatnutzung sowie im Verhalten wurden herausgearbeitet. (orig.)

  10. Chemical-physical studies on SO{sub 2} deposition on rock samples and other absorber surfaces; Chemisch-physikalische Untersuchungen zur Deposition von Schwefeldioxid auf Gesteinsproben und anderen Absorberoberflaechen

    Energy Technology Data Exchange (ETDEWEB)

    Wiese, U.

    2000-07-01

    Stone and other surfaces are still corroded by dry-deposited sulphur dioxide, although the present concentration is in the lower ppbv range. In this work experiments were conducted to separate and assign the different resistances during the deposition process at concentrations of SO{sub 2} found in the environment today. To compare surfaces with different reactivities, the varying uptake and the resulting SO{sub 2} concentration over the surface has to be concerned. Therefore a test chamber has been developed that allows the SO{sub 2} concentration to keep constant independent of the SO{sub 2} uptake. Different stones and passive samplers were investigated in this chamber, scanning a wide range of humidity and concentration that has not been studied before. The passive sampler was also studied in a closed wind tunnel with a sulphur dioxide containing atmosphere. It has been found that the deposition velocity is increasing with decreasing SO{sub 2} concentration for all stone types. (orig.) [German] Alle technischen Oberflaechen unterliegen Alterungsprozessen. Atmosphaerische Schadgase wie Schwefeldioxid tragen zur Korrosion dieser Oberflaechen in erheblichem Umfang bei. Auch wenn insbesondere die Konzentration an SO{sub 2} in der Aussenluft in den letzten Jahren in den unteren ppbV-Bereich gesunken ist, so ist der Anteil und die Potenz dieses Gases am Zerfallsprozess von Natursteinen aufgrund seiner guten Wasserloeslichkeit und der Saeurestaerke noch immer sehr hoch. Dennoch finden sich in der Literatur kaum zuverlaessige Daten ueber die Schwefeldioxid-Aufnahme verschiedener Natursteinvarietaeten. Insbesondere mangelt es an systematischen Untersuchungen der verschiedenen, den SO{sub 2}-Depositionsprozess bestimmenden Faktoren. Ziel dieser Arbeit war es, einen wesentlichen Beitrag zur Schliessung dieser Luecken zu leisten. Dazu wurde ein Messsystem zur Untersuchung verschiedenartiger Gesteinsproben im Labor konzipiert und in Betrieb genommen. (orig.)

  11. Multitracer studies for determining seepage water and anion movement in four types of soil using lysimeters with different functions and designs; Multitracer-Untersuchungen zur Bestimmung der Sickerwasser- und Anionenbewegung in vier Bodenformen bei Lysimetern unterschiedlicher Nutzung und Bauart

    Energy Technology Data Exchange (ETDEWEB)

    Knappe, S.; Russow, R. [UFZ - Umweltforschungszentrum Leipzig-Halle GmbH, Bad Lauchstaedt (Germany). Sektion Bodenforschung; Seeger, J. [Lysimeterstation Falkenberg (Germany)

    1999-02-01

    Lysimeter experiments based on the stable isotope tracer technique are a suitable means of examining the complex relationships governing water and material transport processes in the soil. The present paper reports on experiments in which water and nitrate movement was traced directly by means of lysimeters placed at different depths and using deuterium water and [{sup 15}N]N-nitrate for pulse marking. Extensive investigations carried out during the dissection of soil monoliths that had been used for many years in lysimeters offered an opportunity for stable isotope tracer studies aimed at determining seepage water and anion movement in undisturbed soils and, after dismantling the lysimeters, conducting soil analyses to find out more about the fate of nonpercolated tracers at various soil depths. Following other authors, bromide anions were additionally used as conservative tracers. [Deutsch] Zur Untersuchung der komplexen Zusammenhaenge des Wasser- und Stofftransportes im Boden bieten sich Lysimeterversuche unter Nutzung der stabilisotopen Tracertechnik an. In der vorliegenden Arbeit wird zunaechst ueber die direkte Verfolgung der Wasser- und Nitrat-Bewegung in tiefengestaffelten Lysimetern durch Pulsmarkierung mit Deuteriumwasser und [{sup 15}N]Nitrat berichtet. Im Rahmen von umfangreichen Untersuchungen bei der Zerlegung von langjaehrig in Lysimetern genutzten Bodenmonolithen bestand des weiteren die Moeglichkeit, stabilisotope Traceruntersuchungen zur Bestimmung der Sickerwasser- und Anionenbewegung an ungestoerten Boeden durchzufuehren und nach der Zerlegung der Lysimeter ueber entsprechende Analysen des Bodens Aussagen zum Verbleib der nicht perkolierten Tracer in verschiedenen Bodentiefen zu treffen. Zusaetzlich wurde dabei das von anderen Autoren bereits genutzte Bromid-Anion als sogenannter konservativer Tracer eingesetzt. (orig.)

  12. Environmental medicine field studies in the Bitterfeld and Hettstedt districts and in a control district. 1992-1994. Data book; Umweltmedizinische Untersuchungen im Raum Bitterfeld, im Raum Hettstedt und einem Vergleichsgebiet. 1992-1994. Data Book

    Energy Technology Data Exchange (ETDEWEB)

    Heinrich, J; Popescu, M; Wjst, M; Trepka, M J; Cyrys, J; Wichmann, H E

    1995-03-01

    For the purpose of establishing an inventory of environmental medicine data for the eastern Lands of Germany (of the former GDR), field studies have been carried out in the strongly polluted districts of Bitterfeld and Hettstedt and in a low-pollution control district, around Zerbst. The data were intended to reveal the environmental pollution level in various districts and regions, and to indicate regions of priority for immediate research activities to be initiated. The report covers the results compiled in the first project period, in 1992 and 1993. The data presented are for the most part tabulated data taken from the Final Report of the Bitterfeld Study (Heinrich et al.; 1994). Some tables of immunological parameters have been modified. These data are supplemented by data on internal heavy metal concentrations. The data refer to the anamnesis, especially of respiratory tract disease or allergies, complaints and symptoms, lung functional data, allergiologic findings, hematologic data (only of infants and children), immunologic parameters, and heavy metal accumulations. (orig.) [Deutsch] Fuer eine Bestandsaufnahme der umweltmedizinischen Forschung in der DDR, die Herausarbeitung von regionalen Umweltbelastungsschwerpunkten und die Darstellung des akuten Foerderungsbedarfs wurden umweltmedizinische Untersuchungen in den hochbelasteten Regionen Bitterfeld und Hettstedt sowie im gering belasteten Vergleichsgebiet Zerbst durchgefuehrt. Die vorliegende Zusammenstellung bezieht sich auf die Ergebnisse der ersten Untersuchungsetappe in den Jahren 1992/93. Es werden Daten tabellarisch zusammengestellt, die in dem Abschlussbericht der `Bitterfeld-Studie` (Heinrich, et al.; 1994) enthalten sind. Einzelne Tabellen zu immunologischen Parametern wurden modifiziert. Zusaetzlich werden die Daten durch die interne Schwermetallbelastung ergaenzt. So wird Bezug genommen auf die Krankengeschichte, speziell von Atemwegserkrankungen und Allergien, Beschwerden und Symptomen, auf

  13. Engineering geological and hydrogeological invstigations for storage of medium and low-activity nuclear waste at Cernavoda, Romania. Soil stabilisation using the CONSOLID system; Ingenieurgeologische und hydrogeologische Untersuchungen zur Lagerung mittel- und schwachradioaktiver Abfaelle in Cernavoda Rumaenien. Baugrundstabilisierung mit dem CONSOLID-System

    Energy Technology Data Exchange (ETDEWEB)

    Giurgea, V.; Merkler, G.P.; Hoetzl, H.; Hannich, D. [Karlsruhe Univ. (T.H.) (Germany). Lehrstuhl fuer Angewandte Geologie

    1998-12-31

    In Cernavoda/Romania investigations and planning from a low and middle radioactive waste disposal site have been carried out. A multitude of hydrogeological, geological, engineering geological criteria`s and constructional security measures were examined with respect to the strict regulations for such a waste site. This studies and measures are shortly analyzed and discussed in this paper. In accordance with the selection criteria for such a hazardous waste site, several laboratory and `in situ` tests, soil-mechanic studies, numerical modeling and foundation tests for soil stabilization with the CONSOLID-System are presented. (orig.) [Deutsch] Zur Einhaltung der strengen Vorgaben, die bei einem Deponiestandort fuer mittel- und schwachradioaktive Abfaelle gestellt werden, sind in Cernavoda/Rumaenien eine Vielzahl von hydrogeologischen und ingenieurgeologischen Untersuchungen sowie bautechnischen Sicherungsmassnahmen vorgesehen, die im Rahmen dieser Publikation kurz analysiert und diskutiert werden. Im Zusammenhang mit den geologischen und hydrogeologischen Auswahlkriterien des Standortes werden eine Reihe von Labor- und `in situ` Untersuchungen, Modellrechnungen sowie Baugrundstabilisierungsmassnahmen mit dem CONSOLID-System vorgestellt. (orig.)

  14. The use of electron spin resonance spectroscopy for the detection of irradiated shellfish and spices; Elektronenspinresonanz-spektroskopische Untersuchungen zur Identifizierung bestrahlter Krustentiere und Gewuerze: Durchfuehrung eines Ringversuches an Nordseekrabben, Kaisergranat und Paprikapulver

    Energy Technology Data Exchange (ETDEWEB)

    Helle, N. [Inst. fuer Sozialmedizin und Epidemiologie des Bundesgesundheitsamtes, Berlin (Germany); Linke, B. [Inst. fuer Sozialmedizin und Epidemiologie des Bundesgesundheitsamtes, Berlin (Germany); Boegl, K.W. [Inst. fuer Sozialmedizin und Epidemiologie des Bundesgesundheitsamtes, Berlin (Germany); Schreiber, G.A. [Inst. fuer Sozialmedizin und Epidemiologie des Bundesgesundheitsamtes, Berlin (Germany)

    1994-12-31

    nicht laenger aufrechterhalten werden koennen. Einer Aufnahme der ESR-Methode fuer die Identifizierung von Krustentieren und Gewuerzen in die Sammlung der amtlichen Methoden nach Paragraph35LMBG steht nach Meinung der Autoren nichts mehr im Weg. Dennoch bleiben eine Reihe von Forschungsaufgaben im Bereich der beiden hier behandelten Lebensmittelgruppen zu loesen, von denen hier nur einige genannt werden sollen: - Untersuchungen an weiteren Krustentierarten zur Erstellung einer Spektrensammlung, die in der Routinekontrolle verwendet werden kann; - Die Aufklaerung der Struktur der (neben dem CO{sup 2-}-Radikal) bestrahlungsspezifisch gebildeten Radikale; - Untersuchung des Einflusses von Herkunft, Fangzeit und Entwicklungsstadium der Tiere auf die ESR-Spektren; - Untersuchung weiterer Gewuerze; - Aufklaerung des Zusammenhanges von Cellulosegehalt und Radikalkonzentration. (orig./vhe)

  15. Investigations to single and combined effects of organic pollutants (PAH, PCB) and heavy metals (Cd, Cu) on biomass production and soil-plant transfer by cultivation of raw and energy plants. Final report; Bodenoekologische Untersuchungen zur Wirkung und Verteilung von organischen Stoffgruppen (PAK, PCB) in ballungsraumtypischen Oekosystemen. Untersuchungen zu Einzel- und Kombinationswirkungen von organischen Schadstoffen (PAK, PCB) und Schwermetallen (Cd, Cu) auf Biomasseertrag und Boden-Pflanze-Transfer beim Anbau von Rohstoff- und Energiepflanzen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Metz, R.; Dorn, J.; Sauer, W.

    1997-05-01

    Together with polycyclic aromatic hydrocarbons, polychlorinated biphenyls and heavy metals other elements and compounds as well as nutrients are present in typical contaminated areas like sewage fields. They are found as mixed undisturbed contamination and the transfer of these pollutants into food or forage plants is dangerous for people. So far investigations of ecological effects of these substances are focused mainly on single agents or on some agents of the same chemical group. But in most cases the mixture of different chemical compounds in extremely contaminated fields cause synergistic effects resulting in yield reduction and decrease of microbiological activity. Therefore the aim of the present report is to show combined effects of selected organic pollutants (benzo-a-pyren, 2,2`, 5,5` tetrachlorbiphenyl) and heavy metals (cadmium, copper) on parameters of soil biology, biomass production and pollutant uptake by plants. Resulting changes of cellulose decomposition, CO{sub 2}-release from soil and N-mineralization after separated and combined enrichment of weakly polluted sewage field soil with said pollutants up to concentrations of extremely polluted sewage field soils are presented in this paper. Data of yields and pollutant contents of plants (rye, maize and potatoes) cultivated on experimental soils are summarised and ecotoxicological risks resulting form pollutants and their interactions discussed. (orig.) [Deutsch] Polycyclische aromatische Kohlenwasserstoffe, Polychlorierte Biphenyle und Schwermetalle sind zusammen mit anderen Elementen und Verbindungen u.a. auch mit Naehrstoffen als gemischte gewachsene Kontamination in ballungsraumtypischen Belastungsflaechen (z.B. Rieselfelder) vorhanden und stellen bei einem Transfer in Nahrungs- und Futterpflanzen eine besondere Gefaehrdung fuer den Menschen dar. Bei Untersuchungen hinsichtlich oekosystemarer Konsequenzen dieser Substanzen wurden bisher vor allem Einzelstoffbetrachtungen angestellt bzw. mehrere

  16. The role of computed tomography in evaluation of a white matter edema during postoperative brain radiation therapy; Beobachtung von Oedemen in der weissen Substanz waehrend postoperativer Hirnbestrahlung. Die Rolle computertomographischer Untersuchungen

    Energy Technology Data Exchange (ETDEWEB)

    Thalacker, U.; Somogyi, A.; Nemeth, G. [Imre-Haynal-Univ. fuer Gesundheitswissenschaften, Strahlentherapeutischer Lehrstuhl, Budapest (Hungary); Liszka, G. [Staatliches Onkologisches Inst., Roentgendiagnostische Abt., Budapest (Hungary)

    1998-01-01

    ./MG) [Deutsch] Ziel unserer Untersuchungen war es festzustellen, inwieweit man ein waehrend einer postoperativen Hirnbestrahlung aufgetretenes Oedem und dessen Verlauf nach Diuretikagabe mit Hilfe von computertomographisch ermittelten HE-Werten (Houndsfield-Einheiten) verfolgen kann. In der ersten Untersuchungsserie wurden bei 75 Patienten (Alter 20 bis 65 Jahren; Patientegruppe 1) mit Zephalalgie die HE-Werte der nativen unveraenderten weissen Substanz bestimmt. In der zweiten Patientengruppe befanden sich 20 Patienten mit operierten Gehirntumoren bei denen von Strahlentherapie und nach 10, 20, 30, 40 und 50 Gy die HE-Werte bestimmt wurden. In der dritten Patientengruppe befanden sich 64 Patienten, die wegen eines Gehirntumors bereits operiert worden waren und nun einer postoperativen Radiatio unterzogen wurden. In der zweiten und dritten Patientengruppe wurden die Bestrahlungen teils mit Telekobalt, teils mit Photonen eines Linearbeschleunigers (6 und 9 MeV) durchgefuehrt. Bei der CT-Untersuchungen kam ein Siemens Somatom CR (125 kV, 450 mAs) mit einer Scan-Zeit von 5 s zur Anwendung. In der ersten Patientengruppe stellten wir keine Werte unter 30 HE in der weissen Substanz fest. Die Werte der zweiten Patientengruppe bewegten sich ohne Diuretikagabe zu Beginn der Bestrahlung zwischen 25 und 29 HE. Bei einem Abfall unter 25 HE traten Dauerkopfschmerz, Schwindel und Querulanz auf. In diesen Faellen wurde die diuretische Behandlung so lange gesteigert, bis wieder Werte von 25 bis 29 HE vorlagen. In derm18itten Patientengruppe stellten wir zu Beginn der Radiatio bei 47 von 64 Patienten Werte von 25 bis 29 HE fest. Obwohl jedem Patienten von Anfang an Furosemid verabreicht wurde, verringerten sich bei 28 Patienten die Werte auf 20 bis 24 HE. Eine Verbesserung konnte mit zusaetzlicher Gabe von Glyzerin per os erreicht werden. Daraufhin pendelten sich die Werte auf 25 bis 29 HE ein. Lediglich in einem Fall fielen die Werte unter 20 HE. Hier war eine zusaetzliche Gabe Mannit

  17. High-resolution seismic studies on geothermal heat extraction from low, permeable rock strata in the city of Hanover using depth-dependent, optimized acquisition parameters; Hochaufloesende seismische Untersuchungen zur Erdwaermegewinnung aus tiefen, permeablen Gesteinsformationen im Stadtgebiet Hannover unter Verwendung von Profilen mit teufenabhaengig optimierten Akquisitionsparametern

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, R. [GGA-Inst. fuer Geowissenschaftliche Gemeinschaftsaufgaben, Hannover (Germany)

    2002-07-01

    The investigations accompanied a demonstration project on geothermal heat production planned by GEOZENTRUM, Hanover, in which geothermal heat will be produced from muschelkalk and mottled sandstone in the area of Hanover/Misburg by means of ''generated geothermal systems'' (GeneSys). This involves detailed seismic exploration of the geological strata of all depth levels. Profile data of the Thoense gas field will be integrated. [German] Die Untersuchungen stehen im Zusammenhang mit dem vom GEOZENTRUM-Hannover geplanten Demonstrationsvorhaben zur Erdwaermegewinnung mittels ''Generierter geothermischer Energie Systeme'' (GeneSys) im Stadtgebiet Hannover/Misburg. Zielhorizonte sind der Muschelkalk und der Buntsandstein. Dazu sollten die geologischen Strukturen im gesamten Teufenbereich detailliert seismisch erkundet werden, wobei neben neuen Messungen auch die vorliegenden Informationen aus bereits gemessenen Profilen des Gasfeldes Thoense einfliessen. (orig.)

  18. Comparative studies on ultrasonic, friction, laser and resistance pressure welding of NiTi shape memory alloys with high-alloy steels. Final report; Vergleichende Untersuchungen zum Ultraschall-, Reib-, Laserstrahl- und Widerstandspressschweissen von NiTi-Shape-Memory-Metall mit hochlegierten Staehlen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Zuckschwerdt, K.

    2000-04-01

    The suitability of different welding techniques for welding of NiTi shape memory alloys with high-alloy steel (C12CrNi17-7, X5CrNiNb19-9, X20Cr13) was investigated. The quality of the welds was analyzed using mechanical-technological, fractographic, metallographic and electron microscopy analysis. [German] Ziel dieses Forschungsvorhabens ist es, die Eignung der einzelnen Schweissverfahren fuer das Fuegen von NiTi-Formgedaechtnislegierungen mit hochlegiertem Stahl (X12CrNi17-7, X5CrNiNb19-9, X20Cr13) darzustellen und zu beurteilen. Die Qualitaet der Fuegeverbindungen wird mit Hilfe mechanisch-technologischer, fraktographischer, metallographischer und elektronenmikroskopischer Untersuchungen bewertet.

  19. AG Turbo, Turbotech II, project 1.244. Experimental investigations of rotary instabilities in axial compressors and their effects in terms of compressor stability. Final report; AG Turbo, Turbotech II, Vorhaben 1.244. Experimentelle Untersuchungen rotierender Instabilitaeten in Axialverdichtern und ihr Einfluss auf die Verdichterstabilitaet. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Holste, F; Haukap, C; Kameier, F

    2000-07-10

    The physical phenomena of rotary instabilities in industrial compressors and high-pressure aircraft compressors were investigated, which may be a cause of compressor blade fracture. The investigations were carried out by Duesseldorf Technical University on behalf of Rolls-Royce Deutschland GmbH at the new four-stage low-pressure compressor test stand of TU Dresden University. Extensive measurements were made both in the rotary and stationary system in the third compressor stage. Rotary instabilities could be detected by increasing the clearance between the blade tip and compressor wall. Modal analyses yielded a rate of about 30 for 63 blades, i.e. a characteristic wavelength of about twice the length of a blade. So far, an accurate description of the physical mechanism was impossible. Investigations using a Snubber model showed no significant influence on the rotary instabilities. [German] Im Turbotech II Forschungsvorhaben 1.244 wurden die physikalischen Vorgaenge der rotierenden Instabilitaet untersucht, die sowohl in industriellen Verdichtern als auch in Hochdruckverdichtern von Flugtriebwerken auftreten koennen. Diese Instabilitaeten stellen eine zusaetzliche Belastung fuer die Verdichterblaetter dar und koennen damit die Ursache fuer Blattbrueche sein. Im Auftrag von Rolls-Royce Deutschland wurden die Untersuchungen von der Faachhochschule Duesseldorf durchgefuehrt. Testobjekt war der neu aufgebaute vier stufige Niedergeschwindigkeitsverdichter der TU Dresden. In enger Kooperation mit den Vorhaben 1.243 und 1.246 wurden umfangreiche Messungen sowohl im rotierenden als auch im festen System an der dritten Stufe des Verdichters durchgefuehrt. Durch Vergroesserung des Spaltes zwischen Schaufelspitze und Verdichterwandung konnten rotierenden Instabilitaeten nachgewiesen werden. Modenanalysen ergaben Umfangsordnungen von ungefaehr 30 bei einer Blattzahl von 63, wodurch die charakteristische Wellenlaenge etwa zwei Schaufelwellenlaengen entspricht. Eine exakte

  20. Laboratory experiments and analytical investigations on the transfer of organic substances from lignite into ground water and residue lakes during flooding of opencast lignite mines. Final report; Laborexperimente und analytische Untersuchungen ueber den Eintrag braunkohlebuertiger organischer Stoffe in Grundwaesser und Restseegewaesser bei der Flutung von Braunkohletagebauen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Herzschuh, R.; Frauendorf, H.; Herrmann, D.; Pietzsch, K.

    2000-05-01

    Lignite samples of diffrent lithotypes and composition from opencast mines of Lusatia and the region near Leipzig were submitted to weathering processes in laboratory scale experiments and the transfer of organic matter from lignite into the hydrosphere has been observed. By means of high-performance liquid chromatography/electrospray mass spectrometry used in combination with data from gas chromatography/mass spectrometry numerous lignite-derived aromatic and heteroaromatic (poly-)carboxylic acids as well as aliphatic dicarboxylic acids could be characterized in the aqueous extracts. Investigations on water samples from lignite mining residue lakes cofirm these results. Furthermore, formation of chlororganic compounds like polychlorinated dibenzo-p-dioxine and furans (PCDD/F) and polychlorinated biphenyls (PCB), benzenes (PCBz) and phenols (PCPh) has been investigated on different lignite samples under natural weathering conditions and thermal treatment. (orig.) [German] Braunkohlen verschiedener Lithotypen und Zusammensetzung aus Tagebauen der Lausitz und der Region um Leipzig wurden in Laborexperimenten Verwitterungsprozessen unterzogen und der Uebergang organischer Materie aus der Braunkohle in die Hydrosphaere beobachtet. Mit Hilfe der HPLC-Elektrospray-MS-Untersuchungen in Kombination mit Daten aus GC-MS-Messungen konnten zahlreiche aus der Braunkohle stammende aromatische und heteroaromatische (Poly-)Carbonsaeuren sowie aliphatische Dicarbonsaeuren in den waessrigen Extrakten charakterisiert werden. Untersuchungen an Wasserproben aus bereits gefluteten Tagebaurestseen bestaetigen diese Ergebnisse. Weiterhin wurde die Bildung chlororganischer Verbindungen, wie polychlorierter Dibenzo-p-dioxine und -furane (PCDD/F) sowie polychlorierter Biphenyle (PCB), Benzole (PCBz) und Phenole (PCPh) an unterschiedlichen Braunkohleproben unter natuerlichen Bedingungen und nach thermsicher Behandlung untersucht. (orig.)

  1. Investigations of the corrosion behaviour of special heat exchanging materials in sodium acetate trihydrate melt for the application latent heat storage; Untersuchungen des Korrosionsverhaltens ausgewaehlter Waermeaustauscherwerkstoffe in Natriumacetat-Trihydrat-Schmelze fuer den Anwendungsfall Latentwaermespeichersysteme

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, B.; Stimming, U. [ZAE Bayern, Walter-Meissner-Str. 6, 87748 Garching (Germany)

    2004-06-01

    die verstaerkte Nutzung der z. T. unregelmaessig anfallenden regenerativen Energien sowie von Abwaerme. Der besondere Vorteil der Latentwaermespeicherung besteht in der hohen Energiespeicherdichte, die bei ausgewaehlten Speichermaterialien am Schmelzpunkt erreicht werden kann, und die daraus resultierende Platzeinsparung sowie die nahezu konstante Temperatur. Eine wesentliche Aufgabe bei der Entwicklung solcher Speichersysteme ist die Erhoehung der Langzeitstabilitaet, speziell die Korrosionsstabilitaet ausreichend waermeleitfaehiger Metalle, die als Waermeaustauschermaterial verwendet werden. Das Waermeaustauschermaterial hat dabei die Funktion, die Waerme oder Kaelte von einem Waermeuebertragungsmedium, z. B. Wasser, das die Energie von einer externen Quelle aufgenommen hat, auf das Speichermaterial zu uebertragen. Bei den Speichermaterialien hat sich das Natriumacetetat-Trihydrat mit einem Schmelzpunkt von 58 C als besonders vorteilhaft erwiesen. Eine wichtige Aufgabe war daher die Untersuchung des Korrosionsverhaltens und die Ableitung geeigneter Waermeaustauschermaterialien. Im vorliegenden Beitrag werden wichtige Ergebnisse der Untersuchung ausgewaehlter Metalle bei 80 C in Natriumacetat-Trihydrat-Schmelze vorgestellt. Dem analysenreinen Natriumacetat-Trihydrat wurden ausserdem gezielt die korrosionsbeeinflussenden Verunreinigungen Chlorid, Sulfat und Karbonat, die im wesentlich preisguenstigeren Salzhydrat technischer Qualitaet vorkommen koennen, zugesetzt. Darueber hinaus wurde der Zusatz von Grafit (zur Erhoehung der Waermeleitfaehigkeit) sowie der Zutritt von Luft untersucht. Aus den Untersuchungen wurden mehrere, fuer den genannten Anwendungsfall besonders aussichtsreiche Metalle abgeleitet. (Abstract Copyright [2004], Wiley Periodicals, Inc.)

  2. Full scale application of the autotrophic denitrification in trickling filters for treatment of rejection water with high ammonia concentrations from sludge dewatering. Final report; Untersuchungen zur autotrophen Stickstoffentfernung aus ammoniumreichem Filtratwasser der Schlammentwaesserung mit grosstechnischer Realisierung in Tropfkoerpern. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Neumueller, B.; Metzger, J.W.; Pinnekamp, J.

    2003-07-01

    strictly. In a semi-technical anammox-reactor which was operated for several years showed, that the process is very robust. Performance loss is only temporary, if the operating conditions aren't fulfilled. (orig.) [German] Bei kommunalen Klaeranlagen mit anaerober Schlammbehandlung faellt bei der Entwaesserung des stabilisierten Schlammes stark ammoniumhaltiges Prozesswasser an. Die Mitbehandlung dieses Teilstroms aus der Schlammbehandlung in der Hauptstrombiologie der Klaeranlage kann zu einer Erhoehung der Stickstoffbelastung von bis zu 20% fuehren. Eine separate Behandlung von Prozesswaessern kann die Stickstoff-Ablaufwerte verbessern und schafft Reserven in der Hauptstrombiologie. Die autotrophe Denitrifikation nach vorangegangener Teilnitritation in Tropfkoerpern ist ein neuartiges Verfahren zur Behandlung hoch ammoniumhaltiger Abwaesser. Hierzu werden in einem ersten Tropfkoerper etwa 60% des Ammoniums zu Nitrit umgewandelt, wobei die Nitratation gehemmt wird. In einem zweiten geschlossenen Tropfkoerper wird das Ammonium unter anoxischen Bedingungen, mit Nitrit als Elektronenakzeptor, zu molekularem Stickstoff oxidiert. Dieses Verfahren wurde erstmals im grosstechnischen Betrieb auf der Klaeranlage Sindelfingen realisiert. Die Untersuchungen zeigten, dass bereits wenige mg/l Ammoniak im ersten Reaktor ausreichten, um die Nitratation zu hemmen. Da die Nitratation nach einem Anstieg und dem darauffolgenden Abfallen der Ammoniakkonzentration zunahm, fand offensichtlich eine Adaption der Biomasse an die hoeheren Ammoniakgehalte statt. Deshalb sollte die Ammoniakkonzentration moeglichst konstant gehalten und groessere Schwankungen ueber eine laengere Zeit vermieden werden. Nur mit der thermischen Abtoetung der Mikroorganismen und dem erneuten Einfahren des Prozesses konnte nach einer Adaption wieder eine vollstaendige Nitratationshemmung bei geringen Ammoniakkonzentrationen gewaehrleistet werden. Durch die aeusserst geringe Wachstumsrate der Anammoxbakterien nimmt

  3. Study in environmental medicine in the areas of Bitterfeld and Hettstedt and a comparison area, 1995 - 1996. Data Book; Umweltmedizinische Untersuchungen im Raum Bitterfeld, im Raum Hettstedt und einem Vergleichsgebiet 1995-1996. Data Book

    Energy Technology Data Exchange (ETDEWEB)

    Heinrich, J.; Jacob, B.; Hoelscher, B.; Wilde, B.; Wolff, H.; Wjst, M.; Cyrys, J.; Wichmann, H.E. [GSF - Forschungszentrum fuer Umwelt und Gesundheit Neuherberg GmbH, Oberschleissheim (Germany). Inst. fuer Epidemiologie

    1998-10-01

    were determined and heavy-metal analyses carried out. Complete blood tests were done for lead, cadmium and mercury; urine tests were done for arsenic, cadmium and mercury. (orig.) [Deutsch] Die Umweltsituation im industriellen Ballungsgebiet Bitterfeld/Wolfen war in der Vergangenheit durch eine ausserordentlich hohe Belastung der Luft, u.a. mit Staeuben, Schwefeldioxid, Stickoxiden und chlorierten Kohlenwasserstoffen, der Gewaesser und des Bodens gekennzeichnet. Dagegen spielte im Raum Hettstedt die Schwermetallbelastung durch jahrzehntelangen Bergbau und die Emissionen der buntmetallurgischen Industriebetriebe die Hauptrolle. Ziel der vom Umweltbundesamt gefoerderten umweltepidemiologischen Studie ist es, moegliche gesundheitliche Beeintraechtigungen der Bevoelkerung in diesen zwei Belastungsgebieten im Vergleich zu dem wenig belasteten Kontrollterritorium Zerbst zu ermitteln. Diese sollen vor dem Hintergrund der Langzeitwirkung einer hohen Luftbelastung in den Regionen Bitterfeld und Hettstedt quantifiziert werden. Darueber hinaus werden die zeitlichen Veraenderungen der Gesundheitsparameter begleitend zu den laufenden Sanierungsmassnahmen ueber einen Zeitraum von 6 Jahren erfasst, um die Sanierung an den gesundheitlichen Gegebenheiten ausrichten zu koennen. Die Untersuchungen 1995/96 erfolgten wie auch beim 1. Survey im Jahre 1992/93 durch Aerzte und Schwestern in Schulen, Kindergaerten, Gesundheitsaemtern sowie teilweise in einem mit Lungenfunktionsgeraeten ausgestatteten Untersuchungsbus. In allen drei Orten wurde nach den gleichen standardisierten Vorschriften verfahren, wobei die gleichen Geraete und die gleichen Untersucher im Einsatz waren. Durch Befragung der Eltern der Kinder wurden Informationen erhoben zu Erkrankungen und Symptomen, insbesondere zu Atemwegserkrankungen und Allergien, sowie zu soziodemographischen Charakteristika und Merkmalen der haeuslichen Umgebung, welche die interessierenden Zielgroessen mitbeeinflussen koennen. Es wurde die

  4. Experimentelle Untersuchungen zur sonographischen Frakturdiagnostik im Kinderalter

    OpenAIRE

    Meuser, Stefan Heinrich Peter

    2010-01-01

    Falsch diagnostiziert und nicht korrekt therapiert können Frakturen im Kindesalter zu Wachstumsstörungen und damit verbundenen lebenslangen Problemen führen. Nach einem Trauma ist die klinische Untersuchung und Bestimmung des Schmerzmaximums gerade bei Kindern oft sehr schwierig. So müssen häufig mehrere Röntgenaufnahmen getätigt werden, ehe eine Fraktur sicher diagnostiziert oder ausgeschlossen werden kann. Die hierbei auftretende ionisierende Strahlung geht jedoch besonder...

  5. Untersuchungen zum Potential eines Verbrennungsmotors mit Druckwellenlader

    OpenAIRE

    Binder, Emanuel

    2015-01-01

    Mithilfe der Abgasturboaufladung lässt sich der Kraftstoffverbrauch im Fahrzeugbetrieb durch das Anheben der spezifischen Motorleistung senken. Im Gegensatz zur mechanischen Aufladung verschlechtert sich jedoch mit der Abgasturbolaufladung das Ansprechverhalten. Eine Möglichkeit den Zielkonflikt von Kraftstoffverbrauch und Ansprechverhalten zu lösen ist es, den Abgasturbolader durch einen Druckwellenladers zu ersetzen. Dieser überträgt die Abgasenergie direkt auf die Frischluft in Form von Dr...

  6. Untersuchungen zur Genauigkeit digitaler intraoraler Scans

    OpenAIRE

    Benedickt, Christopher Roland

    2017-01-01

    Ziel der hier vorliegenden In-vitro-Studie war es, zu untersuchen, ob es bei digitalen int-raoralen Scans zu Verzerrungen, Streckungen, Stauchungen, Verdrillungen oder Biegun-gen, kommt. Als Prüfmodell diente ein vollbezahntes Oberkiefermodell aus einer Chrom-Kobalt-Molybdän-Legierung. Auf diesem waren die Zähne 11, 15, 24 und 26 zur Auf-nahme eines Veneers, einer Vollkrone, eines Inlays präpariert, und auf inzisalen bezie-hungsweise okklusalen Mulden der Zähne 13, 23, 17 und 27 waren Metallk...

  7. Elektrophysiologische Untersuchungen an einzelligen marinen Riesenalgen

    OpenAIRE

    Ryser, Christoph

    2002-01-01

    Die kombinierte Mikroperfusions-/Ladungspulstechnik an einzelligen marinen Riesenalgen ermöglicht die getrennte Darstellung der elektrischen Eigenschaften von Plasmalemma und Tonoplast durch gezielte Manipulation des vakuolären und externen Mediums. Dabei kann der für die Physiologie der Zellen wichtige hydrostatische Innendruck (Turgor) ständig kontrolliert werden. Die Applikation eines Ladungspulses resultierte bei Valonia utricularis und Ventricaria ventricosa in einer biphasischen Relaxat...

  8. Investigations into the formal pathogenesis of quartz-dust-induced tumours of the lungs in rats. Pt. 1. Pneumocyte proliferation and changes in the lung tissue; Untersuchungen zur formalen Pathogenese quarzstaubinduzierter Lungen-Tumoren bei der Ratte. T. 1. Pneumozytenproliferation und Lungenumbau

    Energy Technology Data Exchange (ETDEWEB)

    Friemann, J. [Medizinisches Inst. fuer Umwelthygiene, Univ. Duesseldorf (Germany); Kubitza, R. [Medizinisches Inst. fuer Umwelthygiene, Univ. Duesseldorf (Germany); Weishaupt, C. [Medizinisches Inst. fuer Umwelthygiene, Univ. Duesseldorf (Germany); Varnai, M. [Medizinisches Inst. fuer Umwelthygiene, Univ. Duesseldorf (Germany); Pott, F. [Medizinisches Inst. fuer Umwelthygiene, Univ. Duesseldorf (Germany); Musinski, G. [Medizinisches Inst. fuer Umwelthygiene, Univ. Duesseldorf (Germany)

    1995-12-31

    organisierender Regionen (NOR) durchgefuehrt. Ergaenzend wurden morphometrische Untersuchungen zur Bestimmung des Silikosegrades und zur Quantifizierung der Ausdehnung der Quarzstaub-induzierten bronchioloalveolaeren Hyperplasie durchgefuehrt. Die Untersuchungen fuehrten zusammenfassend zu dem Ergebnis, dass die inhalative und intratracheale Quarzstaubapplikation bei Ratten regelmaessig eine Alveolarproteinose in Kombination mit einer Dosis- und zeitabhaengigen Zunahme der Pneumozytenproliferationsrate induziert. Ferner kommt es regelmaessig zur Ausbildung einer multifokalen adenomatoesen Hyperplasie (bronchiolo-alveolaeren Hyperplasie) des Lungenparenchyms. Die moegliche Bedeutung beider Laesionen fuer die Entstehung experimenteller Quarzstaub-induzierter Lungentumoren wird diskutiert. (orig.)

  9. Reduction of radiation exposure in PET examinations by data acquisition in the 3D mode; Reduktion der Strahlenexposition bei PET-Untersuchungen durch Datenakquisition im 3D-Modus

    Energy Technology Data Exchange (ETDEWEB)

    Brix, G. [Bundesamt fuer Strahlenschutz, Neuherberg (Germany). Inst. fuer Strahlenhygiene]|[Deutsches Krebsforschungszentrum (DKFZ), Heidelberg (Germany). Forschungsschwerpunkt Radiologische Diagnostik und Therapie; Adam, L.E. [Department of Radiology, Philadelphia, PA (United States). Div. of Nuclear Medicine; Zaers, J.; Trojan, H.; Doll, J. [Deutsches Krebsforschungszentrum (DKFZ), Heidelberg (Germany). Forschungsschwerpunkt Radiologische Diagnostik und Therapie; Bellemann, M.E. [Deutsches Krebsforschungszentrum (DKFZ), Heidelberg (Germany). Forschungsschwerpunkt Radiologische Diagnostik und Therapie]|[Fachhochschule Jena (Germany). Fachbereich Medizintechnik; Nosske, D. [Bundesamt fuer Strahlenschutz, Neuherberg (Germany). Inst. fuer Strahlenhygiene

    1999-04-01

    , auf die abschirmende Wirkung von Septen zwischen den einzelnen Detektorringen (2D-Modus) zu verzichten, so dass auch koinzidente Ereignisse zwischen Detektoren auf weiter entfernt liegenden Ringen erfasst werden koennen (3D-Modus). Ziel der vorliegenden Arbeit war es, das Zaehlratenverhalten eines PET-Scanners der neuesten Generation im 2D- und im 3D-Modus anhand von Phantommessungen zu untersuchen und die sich daraus ergebenden Konsequenzen fuer die Strahlenhygiene bei PET-Untersuchungen mit 2-[F-18]-Fluor-2-Desoxyglukose (F-18-FDG) zu diskutieren. Methoden: Alle Messungen wurden am Ganzkoerper-PET-System ECAT EXACT HR{sup +} durchgefuehrt. Fuer die 2D-Messungen wurde ein Kollimator aus duennen Wolframlamellen in das Gesichtsfeld eingebracht. Das Zaehlratenverhalten des Scanners wurde dem NEMA-Protokoll folgend ueber einen weiten Bereich von F-18-Aktivitaetskonzentrationen untersucht. Darueber hinaus wurden PET-Aufnahmen des EEC-Ganzkoerperphantoms mit verschiedenen Einsaetzen im 2D- und im 3D-Modus jeweils ueber 15 min akquiriert, wobei die F-18-Aktivitaetskonzentrationen bei der 3D-Messung halb so hoch waren wie bei der 2D-Messung. Ergebnisse: Fuer das zylinderfoermige NEMA-Phantom (Durchmesser=19,4 cm, Laenge=19,0 cm) ergab sich im 3D-Modus eine im Vergleich zur 2D-Akquisition etwa fuenffach hoehere Systemsensitivitaet (27,7 statt 5,7 cps/Bq/ml). Die Auswertung der rekonstruierten Aktivitaetsverteilungen des EEC-Phantoms ergab, dass die Qualitaet der aus dem 3D-Projektionsdatensatz berechneten PET-Aufnahmen besser war als die der korrespondierenden 2D-Aufnahmen, obwohl die Aktivitaetskonzentrationen nur halb so hoch waren. Schlussfolgerungen: Durch die Datenakquisition im 3D-Modus kann die zu applizierende Aktivitaetsmenge bei gleichzeitiger Verbesserung der Bildqualitaet erheblich reduziert werden. Fuer Patientenuntersuchungen mit F-18-FDG im Ganzkoerperbereich reicht es unserer Erfahrung nach aus, eine Aktivitaet zwischen 150 und 200 MBq zu applizieren. Dies

  10. Theoretical and experimental investigations of on-board control of combustion air and/or fuel for emission reduction in internal combustion engines. Final report; Durchfuehrung theoretischer und experimenteller Untersuchungen zu den Moeglichkeiten der On-Board-Beeinflussung der Verbrennungsluftzusammensetzung und/oder des Kraftstoffs fuer Verbrennungsmotoren mit dem Ziel der Emissionsminderung. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Velji, A.; Hofmann, U.

    2001-11-01

    Theoretical and experimental investigations were made in order to find the optimal composition of combustion air for simultaneous reduction of NOx and particulate emissions. The effect was found to be in the same order of magnitude as with exhaust recirculation. 'Optimized' air should have an oxygen content of more than 20 percent and a CO2 content of more than 10 percent, with nitrogen more or less accounting for the rest. [German] Ausgehend von der Abgasrueckfuehrung wurde in theoretischen und experimentellen Untersuchungen die optimale Zusammensetzung der Verbrennungsluft zur gleichzeitigen Reduktion der NO{sub x}- und Partikelemission ermittelt. Es konnte gezeigt werden, dass es mit dieser Verbrennungsluft moeglich ist, eine aehnlich hohe NO{sub x}-Reduktion wie bei der Abgasrueckfuehrung zu erzielen, ohne dass die Partikelemission drastisch ansteigt. Die 'optimale' Verbrennungsluft muss einen Sauerstoffgehalt groesser als 20% und einen CO{sub 2}-Gehalt groesser als 10% aufweisen. Der Rest besteht im Wesentlichen aus Stickstoff. (orig.)

  11. Studies on image quality, high contrast resolution and dose for the axial skeleton and limbs with a new, dedicated CT system (ISO-C-3D); Untersuchungen zur Bildqualitaet, Hochkontrastaufloesung und Dosis am Stamm- und Gliedmassenskelett mit einem neuen dedizierten CT-System (ISO-C-3D)

    Energy Technology Data Exchange (ETDEWEB)

    Rock, C.; Kotsianos, D.; Linsenmaier, U. [Klinikum der Universitaet Muenchen, Muenchen (Germany). Inst. fuer Klinische Radiologie; Fischer, T. [Klinikum der Universitaet Muenchen, Muenchen (DE). Inst. fuer Klinische Radiologie] (and others)

    2002-02-01

    verwertbare Bildqualitaet; Score 4: hervorragende Bildqualitaet). Zusaetzlich erfolgten Dosismessungen und Hochkontraststudien an einem adaptierten Hochkontrastphantom (Catphan, Phantom Laboratories) im Vergleich zur Niedrigdosis- und Standarddosis-CT. Ergebinsse: Die Untersuchungen kleinerer Gelenke wie Hand-, Sprung-, Ellbogen- und Kniegelenk lieferten eine diagnostische Bildqualitaet (Scoremittelwerte 3-4) bei einer applizierten Dosis im Bereich der einer Niedrigdosis-CT. Dagegen war die Bildqualitaet der Hueftgelenks- und Wirbelsaeulenuntersuchungen trotz Dosiserhoehung um 85% eingeschraenkt (Scorewerte 2-3) und die der Schultergelenksuntersuchungen von schlechter Qualitaet (Score 1). Die Bilddaten der Hochkontraststudien zeigten in der xy-Achse eine der CT vergleichbare Hochkontrastaufloesung (9 LP/cm). Schlussfolgerung: Die vorlaeufigen Ergebnisse zeigen, dass die Bildqualitaet der ISO-C-3D-Untersuchungen von peripheren Gelenken von diagnostischer Qualitaet ist. Am Hueftgelenk und am Stammskelett ist die Bildqualitaet nicht adaequat und erscheint bisher nicht ausreichend zur Frakturdiagnostik. (orig.)

  12. Experimental investigations for provision of a data basis for optimization of active surge control. Final report; Experimentelle Untersuchungen zur Bereitstellung einer Datenbasis fuer die Optimierung der aktiven Stabilitaetsverbesserung. Teilverbund-Projekt: Aktive Stabilitaetsverbesserung - Analyseverfahren der Arbeitsgemeinschaft AG Turbo II. Abschlussbericht zum Vorhaben 1.1.4

    Energy Technology Data Exchange (ETDEWEB)

    Seume, J.; Reissner, A.

    2001-07-01

    Presently axial compressors have to run with considerable distance to operation points of high load although usually the best efficiencies can be obtained there. In those areas there is high danger of surge which brings high damaging potential to the compressor. The prediction time to surge presently is very short (<<1s) and depends on the load and rotor rotation of the compressor. The goal of this project is the production of a data basis to investigate stall inception (which is the precursor of surge) and to develop and test better precursory warning algorithms. An extensive set of data as well in stable as in unstable operating points in different load areas was developed which now is ready for use in research, verification and for comparison of forewarning systems. (orig.) [German] Zur Zeit ist es notwendig, Axialverdichter mit deutlichem Abstand von den hoch belasteten Betriebspunkten zu betreiben, obwohl haeufig dort die besten Wirkungsgrade zu erzielen waeren. In diesen Bereichen kann es leicht zu sog. Pumpen kommen, wodurch der Verdichter einem extremen Schaedigungspotential ausgesetzt ist. Die Vorwarnzeiten fuer das Pumpen sind bisher noch sehr kurz. Sie liegen in einem Bereich von deutlich weniger als einer Sekunde (abhaengig von der Belastung und der Drehzahl des Verdichters). Ziel dieser Untersuchungen ist es, eine Datenbasis zu liefern, anhand derer die Entstehungsmechanismen untersucht und moeglichst fruehzeitige Vorwarnalgorithmen entwickelt bzw. erprobt werden koennen. Es wurde eine umfangreiche Datenbasis sowohl an verschiedenen stabilen als auch instabilen Betriebspunkten in unterschiedlichen Lastbereichen erstellt, die nun zur Entwicklung, zur Verifizierung und zum Vergleich von Fruehwarnsystemen zur Verfuegung steht. (orig.)

  13. Design criteria for crankshafts - axial slide bearing in Otto and diesel engines by means of computer-based simulations and experimental investigations. Axial slide bearing design - final report; Auslegungskriterien fuer Kurbelwellen - Axialgleitlager in Otto- und Dieselmotoren durch rechnergestuetzte Simulation und experimentelle Untersuchungen. Axialgleitlagerauslegung - Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Backhaus, K. [Univ. GH Kassel (Germany). Inst. fuer Maschinenelemente und Konstruktionstechnik; Hunsicker, W. [Fachhochschule Mannheim (Germany). Inst. fuer Tribologie; Schubert, W. [KS Gleitlager GmbH, St. Leon-Rot (Germany)

    2003-07-01

    Einfluss einzelner Parameter, wie der makrogeometrischen Laufflaechengestaltung, untersucht werden. Makrogeometrisch zeichnen sich wellige Anlaufflaechen und Laufflaechen mit Rayleigh-Stufen durch hohe hydrodynamische Tragdruecke aus. Elasto-hydrodynamische Untersuchungen an einem Anlaufbund und unter motorspezifischer Belastung an Anlaufscheiben eines Grundlagers zeigen den Einfluss der Strukturelastizitaet und belegen die Notwendigkeit ihrer Beruecksichtigung bei der Analyse von Einzelsystemen. (orig.)

  14. Investigations performed on the compost worm Eisenia fetida and selected species of earthworms concerning the intake of HCB and pyrene with the goal of deriving a bioaccumulation test; Untersuchungen zur Aufnahme von HCB und Pyren durch den Kompostwurm Eisenia fetida und ausgewaehlte Regenwurmwildarten. Ableitung eines Bioakkumulationstests

    Energy Technology Data Exchange (ETDEWEB)

    Vespermann, A.; Riepert, F.; Pflugmacher, J. [Biologische Bundesanstalt fuer Land- und Forstwirtschaft, Inst. fuer Oekotoxikologie im Pflanzenschutz, Berlin (Germany)

    2003-07-01

    The man issues of the studies described were the validation of a test design for the assessment of the bioaccumulation potential of environmental pollutants and the applicability of Eisenia fetida as a model-organism and artificial soil (OECD) as a standard test substrate. The test organisms used were E. fetida of our own breeding stock and Allolobophora caliginosa, Allolobophora chlorotica, Allolobophora longa and Lumbricus rubellus sampled from a field site. Test soils used were the artificial soil (OECD) and a BBA field soil. Soils were each contaminated with 10 mg HCB and Pyrene per soil dry-weight. Within the test period of 4 weeks, samples were taken weekly for residue analysis in the worms and soils. Bioaccumulation factors (AF) calculated for E. fetida and the free-living species were in the range of 10-17 (HCB) and 0.9-1.7 (Pyrene) depending on the soil used. By re-calculation of the concentrations in soil to concentrations in soil water, the resulting bioconcentration factors are compared with published BCF values determined from QSAR's of other worm species and fresh water fish. It could be concluded that the existing earthworm tests (OECD 1984, ISO 1998) represent an appropriate design for testing the bioconcentration potential of chemicals in soil. (orig.) [German] Ziel der beschriebenen Untersuchungen war die praktische Ueberpruefung eines Methodenentwurfs zur Erfassung der Bioakkumulation von Umweltchemikalien mit Eisenia fetida, der Eignung von E. fetida als Modellorganismus und des OECD-Kunstbodens als Standardsubstrat. Als Testorganismen wurden aus eigener Zucht der Kompostwurm Eisenia fetida und nach Feldentnahme Allolobophora caliginosa, Allolobophora chlorotica, Allolobophora longa und Lumbricus rubellus eingesetzt. Testboeden waren der OECD-Kunstboden und ein Boden vom Versuchsfeld der BBA in Berlin-Dahlem. Beiden Boeden wurden die Testsubstanzen Hexachlorbenzol und Pyren in einer Konzentration von 10 mg/kg Bodentrockengewicht zugemischt

  15. Studies of volatile secondary molasses constituents with inhibitory effect on yeast fermentation. Pt. 1. Determination of molasses and yeast components by GC and HPLC; Untersuchungen ueber fluechtige Nebenbestandteile der Melasse mit inhibitorischer Wirkung auf die Hefegaerung. T. 1. Bestimmung von Melasse- und Hefeinhaltsstoffen mittels GC und HPLC

    Energy Technology Data Exchange (ETDEWEB)

    Fattohi, N.

    1994-07-20

    Beet molasses, the principal raw material of molasses distilleries and yeast factories, have in recent times with increasing frequency shown negative effects on the fermentation and quality of baking yeast. Based on the fact that with many ``problem molasses`` the inhibitory effect on fermentation can be substantially reduced and often even totally eliminated by prior aeration of the hot acidic molasses solution, the chemical-analytical and biological investigations presented here focused on the components of such problem molasses volatilizable in water vapour. The water vapour distillates contain, in particular, low carbon acids (C1-C10), and alkanols (C6-C7), the minimum inhibitory concentrations (m.i.c.) of which for yeast fermentation were established. This showed very high m.i.c. levels for an inhibitory effect on fermentation, which in practice are not reached by the individual carbon acid and alkanol constituents of the problem molasses. However, these acids and alcohols exhibit marked synergic effects which were confirmed by determining the m.i.c. values of mixtures. The inhibitory effect on yeast fermentation is due above all to the presence in problem molasses of butyric acid + caprilic acid + hexanol and heptanol. (orig.) [Deutsch] Ruebenmelasse, der Hauptrohstoff fuer die Melassebrennereien und Hefefabriken, zeigt in letzter Zeit immer haeufiger nachteilige Wirkungen bei der Vergaerung sowie der Qualitaet des Produkts Backhefe. Aufgrund der Tatsache, dass sich bei vielen ``Problemmelassen`` der Gaerhemmeffekt durch vorangehende Belueftung der heiss-sauren Melasseloesung deutlich vermindern, haeufig sogar gaenzlich eliminieren laesst, wurde der Schwerpunkt der vorliegenden chemisch-analytischen und biologischen Untersuchungen auf die wasserdampffluechtigen Komponenten solcher Problemmelassen gelegt. Die Wasserdampfdestillate enthalten insbesondere niedere Carbonsaeuren (C1-C10) und Alkanole (C6-C7). Ihre minimalen Hemmkonzentrationen (MHK) bei der

  16. Electrochemical characterization of electrolytes and electrodes for lithium-ion batteries. Development of a new measuring method for electrochemical investigations on electrodes with the electrochemical quartz crystal microbalance (EQCM); Elektrochemische Charakterisierung von Elektrolyten und Elektroden fuer Lithium-Ionen-Batterien. Entwicklung einer neuen Messmethode fuer elektrochemische Untersuchungen an Elektroden mit der EQCM

    Energy Technology Data Exchange (ETDEWEB)

    Moosbauer, Dominik Johann

    2010-11-09

    neue Methoden entwickelt, um mit der elektrochemischen Quarzmikrowaage (EQCM) Untersuchungen an Elektrodenkomponenten durchfuehren zu koennen. Zunaechst wurden Korrosions- bzw. Passivierungsmessungen an Aluminium durchgefuehrt und die Massen der beteiligten Komponenten mit Hilfe der EQCM abgeschaetzt. Danach wurde auch Aktivmaterialien von Kathoden, in dieser Arbeit Lithiumeisenphosphat (LiFePO4), mit der EQCM untersucht.

  17. Ultrastrukturelle Untersuchungen zur Morphologie und Genese der Spermien von Archaeogastropoda

    Science.gov (United States)

    Kohnert, R.; Storch, V.

    1983-03-01

    The sperm cells of Patella coerulea (Patellacea), Monodonta turbinata, and Gibbula tumida (Trochacea) were investigated by means of transmission electron microscopy. They belong to the primitive type (sensu Franzén) and have more features in common with primitive Bivalvia sperms than with Neritacea. Their head contains an apical acrosome and a roundish nucleus followed by 4 or 5 mitochondria and a centriolar apparatus which consists of two centrioles, one of which bears a flagellum. The sperm cells of Monodonta and Gibbula are very similar to each other and differ mainly in size; Patella exhibits more differences (very small acrosome, subacrosomal space, variable number of spherical mitochondria (origin of spermic dimorphism ?). The development of the sperm cells shows no peculiarities.

  18. Untersuchungen zur Farbreaktion von Amilorid, Chlorhexidin und Proguanil mit Hypobromit

    OpenAIRE

    Huth, Silke

    2004-01-01

    Bei der Reaktion von Amiloridhydrochlorid (1· HCl) mit Brom in alkalischer Lösung wird ein gelbbraunes Dehydrierungsprodukt erhalten, daß als 3-(3-Amino-1,2,4-oxadiazol-5-yl)-5-chlor-2,6-pyrazindiamin (6) identifiziert werden konnte. Durch Vergleich von Massen- und NMR-Spektren der Verbindung 6 mit Spektren von 1· HCl und Referenzsubstanzen I-III konnte auf die verbindung 6 geschlossen werden. Die Struktur wurde durch eine Röntgenstrukturanalyse abgesichert. Erhitzen von Amiloridhydrochlorid ...

  19. Untersuchungen zur meiotischen und somatischen Rekombination in Pflanzen

    OpenAIRE

    Seeliger, Katharina

    2011-01-01

    Somatische und meiotische Rekombination sind für den Erhalt von Genomstabilität und -flexibilität verantwortlich. In dieser Arbeit wurde die Beteiligung verschiedener Proteine aus dem pflanzlichen Modellorganismus Arabidopsis thaliana an Rekombinationsprozessen untersucht. Dabei konnte unter anderem in dieser Arbeit über Immunolokalisationsstudien zum ersten Mal für Pflanzen nachgewiesen werden, dass AtBRCA2 als Mediator der AtRAD51- und AtDMC1-vermittelten Rekombination fungiert.

  20. Irradiation of dried products. Untersuchungen zur Bestrahlung von Trockenprodukten

    Energy Technology Data Exchange (ETDEWEB)

    Gruenewald, T

    1984-07-01

    Typical dry products such as gums, drugs and spices were irradiated with 10 MeV electrons up to doses of 30 kGy. Such treatments led in the majority of cases to an undesirable change in the reological properties of gums. The ingredients of drugs, especially essential volatiles, remained unchanged. In individual cases, however, a dose of 10 kGy was not sufficient to reduce total microbial counts. Changes in the sensory properties were not observed, but with the previous tested spices pronounced changes in sensory properties were not observed, but pronounced changes in colour at doses of 10 kGy were observed. These changes did not affect the quality, however. Changes in taste and odour were not recognizable. To reduce microbial counts as desired, a dose of 10 kGy was sufficient.

  1. Untersuchungen zum atmosphärenchemischen Abbau langkettiger Aldehyde

    OpenAIRE

    Plagens, Heike

    2001-01-01

    In dieser Arbeit wurden die bimolekularen Geschwindigkeitskonstanten für die Reaktionen von Hexanal, Heptanal, Oktanal und Nonanal mit OH and Cl Radikalen bei (298 ± 2) K und (1000 ± 20) mbar experimentell bestimmt. Ebenso wurde die Chlorgeschwindigkeitskonstante für Butanal gemessen. Die Werte sind (in Einheiten von cm3 Molekül-1 s-1) in Tabelle 1 zusammengefaßt. Tabelle 1: Aldehyde kOH kCl Butanal - (2,21 ± 0,16) · 10-10 Hexan...

  2. Untersuchungen am System NMMO/H2O/Cellulose

    OpenAIRE

    Cibik, T.

    2003-01-01

    Die vorliegende Arbeit befasst sich mit der Untersuchung des Zweistoffsystems N-Methylmorpholin-N-oxid (NMMO)/H2O und des Dreistoffsystems NMMO/H2O/Cellulose sowie mit der Herstellung und Charakterisierung von faserverstärkten Cellulosefolien. Das binäre System wird mittels Dynamischer Differenzkalorimetrie und Röntgenweitwinkel-Diffraktometrie untersucht und dadurch das Schmelzverhalten und die Phasenzusammensetzung dieses Systems im festen Zustand als Funktion des NMMO/H2O-Verhältnisses bes...

  3. Untersuchungen zur Rauchgasentstickung mittels Schwefelwasserstoff in Tri-n-butylphosphat

    OpenAIRE

    Homann, Jörg

    2000-01-01

    In der vorliegenden Arbeit wurde die Reaktion von Stickstoffmonoxid (NO) mit Schwefelwassersoff (H2S) in Tri-n-butylphosphat (TBP) im Hinblick auf ein alternatives Verfahren zur Entstickung von Rauchgasen untersucht. Mittels einer gasvolumetrischen Absorptionsapparatur wurden zuerst Daten zur physikalischen Löslichkeit in TBP ermittelt, die für den Erhalt kinetischer Daten der stofftransportüberlagerten Reaktionen in TBP relevant sind. Es sind dies die Henrykoeffizienten von NO, H2S und die d...

  4. Untersuchungen zum Fettsäurestoffwechsel bei koronarer Herzkrankheit

    OpenAIRE

    Richter, Wolf-Stefan

    2001-01-01

    Die nicht-invasive bildgebende Diagnostik hat bei koronarer Herzkrankheit einen wichtigen Stellenwert für die Diagnosestellung und Therapieplanung. In diesem Zusammenhang liefern nuklearmedizinische Verfahren wichtige Daten zur Gewebsperfusion und erlauben die bildliche Darstellung und Quantifizierung relevanter Details des kardiomyozytären Stoffwechsels. Die quantitativ bedeutendste Methode der nuklearmedizinischen Herzdiagnostik ist die Perfusionsszintigraphie mit Tl-201 oder einem der Tc-9...

  5. Untersuchungen zur Regeneration des Hinterendes bei Anaitides mucosa (Polychaeta, Phyllodocidae)

    Science.gov (United States)

    Röhrkasten, A.

    1983-06-01

    Caudal regeneration was investigated in decerebrate Anaitides mucosa and in brain-intact individuals. Both groups show an identical capacity to regenerate lost caudal segments. Furthermore there is no difference in males and females. Low temperature (5 °C) inhibits the regeneration of caudal segments, but it is necessary for normal oogenesis. Under conditions of high temperature (15 °C), caudal regeneration is very extensive. At the same time degeneration of most oocytes occurs.

  6. Investigations on passive containment cooling; Untersuchungen zur passiven Containmentkuehlung

    Energy Technology Data Exchange (ETDEWEB)

    Knebel, J.U.; Cheng, X.; Neitzel, H.J.; Erbacher, F.J. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Inst. fuer Angewandte Thermo- und Fluiddynamik; Hofmann, F. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Projekt Nukleare Sicherheitsforschung

    1997-12-31

    The composite containment design for advanced LWRs that has been examined under the PASCO project is a promising design concept for purely passive decay heat removal after a severe accident. The passive cooling processes applied are natural convection and radiative heat transfer. Heat transfer through the latter process removes at an emission coefficient of 0.9 about 50% of the total heat removed via the steel containment, and thus is an essential factor. The heat transferring surfaces must have a high emission coefficient. The sump cooling concept examined under the SUCO project achieves a steady, natural convection-driven flow from the heat source to the heat sink. (orig./CB) [Deutsch] Das im PASCO Programm untersuchte Verbundcontainment fuer zukuenftige Leichtwasserreaktoren ist ein erfolgversprechendes rein passives System zur Nachwaermeabfuhr nach einem schweren Stoerfall. Die passiven Mechanismen der Waermeuebertragung sind Naturkonvektion und Waermestrahlung. Die durch Waermestrahlung uebertragene Waerme betraegt fuer einen Emissionskoeffizienten von 0.9 etwa 50% der insgesamt ueber das Stahl-Containment abgefuehrten Waerme und ist somit von entscheidender Bedeutung fuer die Nachwaermeabfuhr. Fuer die waermeuebertragenden Oberflaechen ist ein hoher Emissionkoeffizient erforderlich. Das im SUCO Programm untersuchte Sumpfkuehlkonzept realisiert eine stabile Naturkonvektionsstroemung zwischen Waermequelle und Waermesenke. (orig./DG)

  7. Physikalische, chemische und mechanische Untersuchungen an zementierten radioaktiven Abfallprodukten

    OpenAIRE

    Aßmann, D.

    1987-01-01

    Radioactive wastes in liquid, gas or solid forms are produced by the recycling of fuel rods. Liquid middle active waste (MAW) will be fixed in 200 or 400 1 barrels. This work examins the influence of middle active waste on the hydration of cement. The change of the mechanical and physical capacities of the MAW contained products is also analysed. Experiments were performed to determine if cesium and strontium are bounded in the hydration products of cement. The hydration of cement changes wit...

  8. State-of-the-art study on standards for the restoration of existing buildings; State of the Art Studie 'Standards fuer Sanierungen von Bestandsgebaeuden'. Vorbereitende Studie zum 'Energy and GHG Optimised Building Renovation' new annex proposal - Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Cypra, S.

    2009-07-01

    This final report for the Swiss Federal Office of Energy (SFOE) discusses the results of a preliminary study on energy and greenhouse-gas optimised building renovation. The proposals are based on the building standards proposed under the '2000-Watt Society' and 'One-Tonne CO{sub 2} Society' proposals. Comparisons are made with Swiss official building standards as well as Swiss and international standards for zero-energy and passive housing. These standards and requirements are discussed in detail and examples of buildings built to meet them are described. Building standards based on sustainability standards are also discussed and compared. The methodology to be used with respect to single-family homes and apartment blocks is discussed. Finally, knowledge gaps are identified and appropriate literature is listed.

  9. Dynamic computed tomography after bolus injection and infusion of perfluorooctylbromide (PFOB). Computertomographische Untersuchungen zur Dichtekinetik nach Bolusinjektion und Infusion von Perfluorooctylbromid (PFOB). Tierexperimentelle Untersuchungen

    Energy Technology Data Exchange (ETDEWEB)

    Adam, G.; Guenther, R.W.; Goertz, H.; Schiffer, C. (Technische Hochschule Aachen (Germany). Klinik fuer Radiologische Diagnostik); Prescher, A. (Technische Hochschule Aachen (Germany). Inst. fuer Anatomie); Bruchmueller, K. (Technische Hochschule Aachen (Germany). Inst. fuer Versuchstierkunde); Limmer, J. (Boehringer Ingelheim GmbH (Germany))

    1992-05-01

    We investigated the enhancement of the liver, the spleen, and of induced abscesses and the abdominal vessels after administration of 3 g/kg bodyweight Perfluoroocytlbromide (PFOB) on an animal model. Twenty-one rabbits each received the contrast medium as bolus injection and as slow infusion over half an hour. CT was performed between 2 and 48 hours after contrast medium application. Peak enhancement of the liver, the spleen and the liver abscess membrane was found between 24 and 48 hours after PFOB administration, independently of the application mode. Peak enhancement of the abdominal aorta and the IVC was observed within two hours after bolus injection. In this rabbit model PFOB permits best delineation of the vessels after bolus injection within the first two hours, while CT imaging of the liver, the spleen and the liver abscess membrane is best between 24 and 48 hours after contrast medium application, independent of the injection velocity. (orig.).

  10. The masses of nobelium and lawrencium isotopes, the mass difference between {sup 180}W and {sup 180}Hf, and a characterization of the future cryogenic stopping cell of the online mass spectrometer SHIPTRAP

    Energy Technology Data Exchange (ETDEWEB)

    Droese, Christian

    2015-01-29

    This work describes the recent scientific and technical achievements obtained at the high-precision Penning trap mass spectrometer SHIPTRAP. The scientific focus of the SHIPTRAP experiment are mass measurements of short-lived nuclides with proton number larger than 100. The masses of these isotopes are usually determined via extrapolations, systematic trends, predictions based on theoretical models or alpha-decay spectroscopy. In several experiments the masses of the isotopes {sup 252-255}No and {sup 255,256}Lr have been measured directly. With the obtained results the region of enhanced nuclear stability at the deformed shell closure at the neutron number 152 was investigated. Furthermore, the masses have been used to benchmark theoretical mass models. The measured masses were compared selected mass models which revealed differences between few keV/c² up to several MeV/c² depending on the investigated nuclide and model. In order to perform mass measurements on superheavy nuclei with lower production rates, the efficiency of the SHIPTRAP setup needs to be increased. Currently, the efficiency is 2% and mainly limited by the stopping- and extraction efficiency of the buffer gas cell. The stopping and extraction efficiency of the current buffer gas cell is 12%. To this end, a modified version of the buffer gas cell was developed and characterized with {sup 223}Ra ion source. Besides a larger stopping volume and a coaxial injection the new buffer gas cell is operated at a temperature of 40 K. The operation at cryogenic temperatures increases the cleanliness of the buffer gas. From extraction measurements and simulations an overall efficiency of 62(3)% was determined which results in an increase by a factor of 5 in comparison to the current buffer gas cell. Aside from high-precision mass measurements of heavy radionuclides the mass differences of metastable isobars was measured to identify candidates for the neutrinoless double-electron capture. Neutrinoless double-electron capture can only occur if the neutrino is its own antiparticle and a physics beyond the standard model exists since the neutrinoless double-electron capture violates the conservation of the lepton number. Due to its expected long half-life this decay has not yet been observed. However, the decay rate is resonantly enhanced if mother and daughter nuclide are degenerate in energy. Suitable candidates for the search of the neutrinoless double-electron capture have been identified with mass difference measurements uncertainties of about 100eV/c{sup 2}. In this work the results of the mass difference measurements of 12 possible candidates are presented.

  11. Hydrogeologische Untersuchungen im oberflächennahen Opalinuston (Bohrloch Lausen, Schweiz)

    Science.gov (United States)

    Vogt, Tobias; Hekel, Uwe; Ebert, Andreas; Becker, Jens K.; Traber, Daniel; Giger, Silvio; Brod, Monika; Häring, Christian

    2017-09-01

    In Switzerland, the Opalinus Clay is being investigated in detail as a host rock for disposal of radioactive waste. To complement and improve existing data on near-surface decompaction effects, hydraulic-hydrochemical characterization of the Opalinus Clay from the weathering zone into the unweathered rock below was performed. For these investigations, one borehole of a borehole heat-exchanger field in Lausen (Canton Basel-Landschaft, Switzerland), which penetrates the near-surface Opalinus Clay, was completely cored. The hydraulic conductivity was determined by means of hydraulic tests in different depths and shows an decrease from 10-4 m/s at the very shallow weathered zone to 10-13 m/s starting at a depth of 28 m below the decompaction zone. In addition, different groundwater types could be identified. Moreover, the structural investigations indicate the end of the weathering zone at a depth of 18 m and that decompaction has no influence on hydraulic conductivity from 28 m onwards.

  12. Untersuchungen der elektrochemischen Eigenschaften pH-sensitiver Feststoffsensoren in unpolaren Flüssigkeiten

    OpenAIRE

    Müller, Andreas

    2009-01-01

    The area of electrochemistry of non aqueous non-polar liquids has not been intensely studied. Coming from the issue of electrochemical sensors on non-polar liquids the analysis of lubrication oils in the engine of a motor vehicle was taken as an example. The investigation of electrode materials in these media appears interesting from a scientific as well as from a technical approach. An overview of the basics of oil chemistry emphases the importance of additives for the formulation of lubrica...

  13. Investigations on H{sub 2} combustion processes; Untersuchungen zu H{sub 2}-Verbrennungsvorgaengen

    Energy Technology Data Exchange (ETDEWEB)

    Breitung, W.; Hesselschwerdt, E.; Massier, H.; Moeschke, M.; Redlinger, R.; Wilkening, H.; Werle, H.; Wolff, J.

    1995-08-01

    During 1994 results were obtained for turbulent deflagrations, detonation ignition criteria, and detonations. In the field of turbulent deflagrations, two different 2-d codes have been developed, which are capable of describing the large spectrum of combustion regimes important for severe accident analysis. Two series of large scale experiments on turbulent H{sub 2}-air combustion have been completed, one with premixed atmospheres, one with dynamic H{sub 2}-injection into the test volume. They provided new clean data for code evaluation on reactor relevant scale (up to 480 m{sup 3} volume). In the field of detonation ignition criteria different mechanisms were investigated which can trigger a transition from deflagration to detonation (DDT). Large scale experiments were performed on turbulent jet ignition of unconfined H{sub 2}-air mixtures. As in earlier small scale tests, detonation ignition was only observed above 25% hydrogen in air. Such reactive mixtures will be rare in severe accidents. Pressure wave focussing was also investigated experimentally. The Mach numbers necessary to trigger a local detonation in different geometries and in different H{sub 2}-air mixtures were measured on small scale. The conditions necessary for a shockless detonation ignition by induction time gradients were calculated. Only close to the reactor pressure vessel the corresponding temperatures and temperature gradients can possibly exist, not in the remainder of the containment. In the field of detonation modeling the code development was completed. Detonation experiments were performed in a 12 m tube equipped with complex obstacles. Some of the data were used to validate the codes. The remaining analysis will be performed in early 1995. The codes can describe well all important physical phenomena which influence detonation loads in complex 3-d geometries. The validated codes were used to calculate local detonation loads in a preliminary EPR containment. (orig./HP)

  14. Pressure vessel failure at high internal pressure; Untersuchungen zum Versagen des Reaktordruckbehaelters unter hohem Innendruck

    Energy Technology Data Exchange (ETDEWEB)

    Laemmer, H.; Ritter, B.

    1995-08-01

    A RPV failure due to plastic instability was investigated using the ABAQUS finite element code together with a material model of thermal plasticity for large deformations. Not only rotational symmetric temperature distributions were studied, but also `hot spots`. Calculations show that merely by the depletion of strength of the material - even at internal wall temperatures well below the melting point of the fuel elements of about 2000/2400 C - the critical internal pressure can decrease to values smaller than the operational pressure of 16 Mpa. (orig.)

  15. Die Familiennamen des ostfriesischen Kreises Leer : sprachliche und geographisch-statistische Untersuchungen zum Namenbestand um 1940

    NARCIS (Netherlands)

    Ebeling, Rudolf Albert

    2008-01-01

    In deze studie wordt het in 1979 gepubliceerde familienanenregister van de Oostfriese 'Kreis’ Leer ( R. A. Ebeling: Familiennamen im Landkreis Leer um 1940) naamkundig gekarakteriseerd d.m.v. een beschrijving van het onomastisch specifieke van dat repertoire en een onderzoek naar de mogelijke

  16. Phytohormone balance in healthy and diseased conifers. Untersuchungen zum Hormonhaushalt gesunder und kranker Nadelbaeume

    Energy Technology Data Exchange (ETDEWEB)

    Frenzel, B.; Beuther, E.; Christmann, A.; Damsohn, W.; Flachmann, M.; Gepraegs, P.; Gueth, S.; Haas, K.; Huckriede, U.; Kettnaker, U.

    1987-12-01

    The symptoms of forest decline point to disturbances in the equilibrium of various hormones. Starting from reliably healthy trees extent and development of these deviations were examined in sick trees. This was at first done as to ethylene and abscisic acid, as well. Both these hormones display already in needles of healthy trees remarkable changes in their contents depending on age and ecological situation of the tree examined. This is camouflaged by other changes in sick trees, this being different from those changes, which are caused by strong SO/sub 2/-immissions. Since the same holds true for other plant-physiological and ultrastructural characteristics, it is concluded that the recent forest decline and damages caused by SO/sub 2/-immissions are different things. (orig.) With 86 figs., 137 refs.

  17. Effizienz der Rebiopsie der Prostata: Untersuchungen von Transitionalzonen- und lateralen Biopsien

    Directory of Open Access Journals (Sweden)

    Fink KG

    2003-01-01

    Full Text Available Zweck dieser Untersuchung war es, die Effizienz von Transitionalzonenbiopsien und von Biopsien der lateralen Anteile der Prostata zur Karzinomentdeckung zu untersuchen, nachdem eine vorangegangene Biopsie keinen Tumor finden konnte. Methodik: Wir untersuchten 74 Präparate nach radikaler Prostatektomie und unterzogen diese einer sonographisch gezielten Prostatabiopsie ex vivo. Zuerst erfolgte eine Sextantenbiopsie, dann zwei unterschiedliche Rebiopsien. Rebiopsie-Technik A bestand aus einer lateral plazierten Sextantenbiopsie und zwei Stanzen aus den Transitionalzonen je Seite. Rebiopsie-Technik B bestand aus einer Sextantenbiopsie und zwei Stanzen je Seite aus den lateralen Arealen der Prostata. Ergebnisse: Mit der initialen Sextantenbiopsie konnten 39 Karzinome gefunden werden (53 %. Von den verbliebenen Karzinomen konnten mit der Rebiopsie-Technik A 12 Karzinome gefunden werden. In dieser Gruppe fand eine lateral durchgeführte Sextantenbiopsie 12 Karzinome. Die Transitionalzonenbiopsien waren in 5 Fällen positiv, jedoch konnte kein zusätzlicher Tumor entdeckt werden. Mit der Rebiopsie-Technik B wurden 23 Karzinome gefunden. 14 Tumore enthielten die Stanzen der Sextantenbiopsie. Zusätzliche 9 Tumore waren in den Stanzen aus den lateralen Arealen der Prostata enthalten. Schlußfolgerungen: Eine Standard-Sextantenbiopsie hat eine niedrige Sensitivität von nur 53 %. Eine Biopsie, welche die Transitionalzonen inkludiert, ist nicht geeignet, die verbliebenen Karzinome zu finden. In dieser Studie zeigte die Wiederholung einer Sextantenbiopsie mit zusätzlichen Stanzen aus den lateralen Arealen das beste Ergebnis bei der Rebiopsie.

  18. Investigations on the contamination of Saxonian wild boars with radiocaesium; Untersuchungen zur Radiocaesiumbelastung von saechsischem Schwarzwild

    Energy Technology Data Exchange (ETDEWEB)

    Heinrich, T.; Abraham, A.; Preusse, W.; Pianski, J.; Alisch-Mark, M.; Lange, S. [Staatliche Betriebsgesellschaft fuer Umwelt und Landwirtschaft, Radebeul (Germany)

    2016-07-01

    As a result of the Chernobyl fallout some parts of the free state of Saxony were contaminated with radioactive caesium. Based on published maps of the soil contamination and on additional investigations some regions of elevated contamination could be localized. Parallel to soil investigations a game monitoring to wild boars and roe deer was performed. For both types of game typical seasonal variations of contamination were found. In Saxony only the contamination of wild boars is important. In the south of the Vogtland a region was found, where in all seasons the recommended high value of 600 Bq/kg was exceeded in game. In this region the investigation on radiocaesium is now obligatory for wild boars. The hunter can combine this analysis with the analysis on trichina. After three years measurements the region for obligatory analysis was adapted and expanded to neighbouring counties.

  19. Survey about the climatic behaviour of mobile homes; Untersuchungen zum klimatischen Verhalten von Wohnmobilen

    Energy Technology Data Exchange (ETDEWEB)

    Leimer, H.P.; Stein, F. [Hochschule fuer Angewandte Wissenschaft und Kunst HAWK, Hildesheim (Germany). BBS Institut Forschungs- und Materialpruefinst. fuer Angewandte Bauphysik und Werkstoffe des Bauwesens

    2006-02-15

    Traveling with mobile homes gains more and more importance in the mobile world. Very dif-ferent regions are visited during any seasons. A basic premise is the maintenance of a comfortable climate in-side the vehicle. In the context of a research program the thermal and energetic behaviour of mobile homes and the thermal-hygric behaviour of the exterior building elements were investigated subject to the surrounding climate, the user's behaviour and the building elements. (orig.)

  20. Anaerobic degradation of paunch and pig stomach contents. Untersuchungen zum anaeroben Abbauverhalten von Pansen- und Schweinemageninhalten

    Energy Technology Data Exchange (ETDEWEB)

    Tritt, W.P. (Bundesforschungsanstalt fuer Landwirtschaft, Braunschweig (Germany, F.R.). Inst. fuer Technologie)

    1989-11-01

    Slaughtering wastes amount to about 60 kg of paunch and 1 kg of pig stomach contents per animal. Each slaughterhouse is responsible for the disposal of these wastes. Anaerobic degradation is among the solutions suggested. It is a process developing gases, and reducing odors and volumes of wastes. Details are given on investigations assessing the methane yields expected, degradation characteristics, and the required amount of inoculants. (orig.).

  1. Quantum chemical analysis of binary and ternary ferromagnetic alloys; Quantenchemische Untersuchungen binaerer und ternaerer ferromagnetischer Legierungen

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, Yasemin Erika Charlotte

    2007-02-23

    In this work the electronic structures, densities of states, chemical bonding, magnetic exchange Parameters and Curie temperatures of binary and ternary ferromagnetic alloys are analyzed. The electronic structure of ferromagnetic MnAl has been calculated using density-functional techniques (TB-LMTO-ASA, FPLAPW) and quantum chemically analyzed by means of the crystal orbital Hamilton population analysis. The crystal structure of the ferromagnetic tetragonal MnAl may be understood to originate from the structure of nonmagnetic cubic MnAl with a CsCl motif through a two-step process. While the nonmagnetic cubic structure is stable against a structural deformation, antibonding Mn-Mn interactions at the Fermi level lead to spin polarization and the onset of magnetism, i.e., a symmetry reduction taking place solely in the electronic degrees of freedom, by that emptying antibonding Mn-Mn states. Residual antibonding Al--Al states can only be removed by a subsequent, energetically smaller structural deformation towards the tetragonal system. As a final result, homonuclear bonding is strengthened and heteronuclear bonding is weakened. Corresponding DFT calculations of the electronic structure as well as the calculation of the chemical bonding and the magnetic exchange interactions have been performed on the basis of LDA and GGA for a series of ferromagnetic full Heusler alloys of general formula Co2MnZ (Z=Ga,Si,Ge,Sn), Rh2MnZ (Z=Ge,Sn,Pb), Ni2MnZ (Z=Ga,In,Sn), Pd2MnZ (Z=Sn,Sb) and Cu2MnZ (Z=Al,In,Sn). The connection between the electronic spectra and the magnetic interactions have been studied. Correlations between the chemical bondings in Heusler alloys derived from COHP analysis and magnetic phenomena are obvious, and different mechanisms leading to spin polarization and ferromagnetism are derived. The band dependence of the exchange parameters, their dependence on volume and valence electron concentration have been thoroughly analyzed within the Green function technique. Finite temperature effects (Curie temperatures) are analysed using the mean-field description, and a surprisingly simple relationship between structural properties and the Curie temperature is found. The magnetic exchange parameters and also Curie temperatures decrease along the row Cu, Ni, Rh, Pd. The X-Mn interactions are limited by first neighbors while Mn-Mn interactions are quite long ranged. Non-spin-polarized COHP bonding analyses evidence antibonding metal-metal interactions as a prerequisite for becoming ferromagnetic, and these show up for the 3d-metal-Mn and also 4d-metal-Mn combinations but not for the wider Mn-Mn interactions. As an exception to this rule, the Cu2MnZ class of compounds evidences, on the opposite, large antibonding Mn-Mn interactions at the Fermi level. (orig.)

  2. Scintigraphic examinations after stent implantation in central airways; Szintigraphische Untersuchungen bei Stents in den zentralen Atemwegen

    Energy Technology Data Exchange (ETDEWEB)

    Richter, W.S.; Kettner, B.I.; Munz, D.L. [Klinik und Poliklinik fuer Nuklearmedizin, Universitaetsklinikum Charite, Medizinische Fakulteat der Humboldt-Univ. zu Berlin (Germany)

    1998-03-01

    Endotracheal and endobronchial stent implantation has been developed as an effective treatment of benign and malignant airway stenosis and of tracheo- or bronchoesophageal fistulas. The selection of the stent type depends on the kind and site of disease. Chest X-ray and bronchoscopy are the procedures of choice for monitoring of stent position, structure, and function. However, with scintigraphic methods the effects of stent implantation on pulmonary ventilation and perfusion can be assessed non-invasively. The validation of the effect of a stent implantation on mucociliary and tussive clearance remains to be elucidated. (orig.) [Deutsch] Die endotracheale und -bronchiale Stentimplantation wurde in den letzten Jahren als effektive Massnahme bei benignen und malignen Stenosen der Atemwege, drohendem Atemwegsverschluss und bei tracheo- bzw. bronchooesophagealen Fisteln eingefuehrt. Der gewaehlte Stenttyp richtet sich nach dem Implantationsort und den krankheitsbedingten Veraenderungen. Zum Monitoring von Lage, Struktur und Funktion eines Stents dienen Thoraxroentgenaufnahmen und die Bronchoskopie. Nuklearmedizinische Verfahren koennen nicht-invasiv den Effekt der Stenteinlage auf Lungenventilation und -perfusion belegen. Die Validierung des Effekts einer Stentimplantation auf die mukoziliaere und tussive Clearance steht noch aus. (orig.)

  3. Theoretical investigations of metallic surfaces for water chemistry; Theoretische Untersuchungen metallischer Oberflaechen fuer die Wasserstoffchemie

    Energy Technology Data Exchange (ETDEWEB)

    Schnur, Sebastian

    2010-11-19

    Properties of the metal-water interface have been addressed by periodic density functional theory calculations, in particular with respect to the electronic and geometric structures of water bilayers on several transition metal surfaces. The structure and the vibrational spectra of water bilayers at room temperatures have been studied performing ab initio molecular dynamics simulations. In order to model varying electrode potentials, an explicite counter electrode has been implemented in a periodic density functional theory code, and first preliminary results using this implementation will be presented. (orig.)

  4. Untersuchungen zur Durchströmung, Beladung und Regeneration eines Diesel-Partikelfilters

    OpenAIRE

    Höffken, Tobias

    2009-01-01

    Aufgrund strenger gesetzlicher Vorgaben müssen Rußpartikel aus dem Abgas moderner Diesel-PKW durch Filtration abgeschieden werden. Durch den Aufbau einer Rußschicht auf der Oberfläche des Filters nimmt der Abgasgegendruck während des Fahrzeugbetriebs zu, so dass dieser in regelmäßigen Abständen durch Abbrand des eingelagerten Rußes regeneriert werden muss. Während des Rußabbrands kann es im Filter zu Temperaturüberhöhungen kommen, die zu dessen Zerstörung führen. Gegenstand der vorliegend...

  5. Supporting the low-voltage distribution network with supercapacitors; Untersuchungen zur Stuetzung des Versorgungsnetzes mit Doppelschichtkondensatoren

    Energy Technology Data Exchange (ETDEWEB)

    Guetif, Abdelkader [VDE Pruef- und Zertifizierungsinstitut GmbH, Offenbach am Main (Germany); Kurrat, Michael [Technische Univ. Braunschweig (Germany). Inst. fuer Hochspannungstechnik und Elektrische Energieanlagen; Meins, Juergen [Technische Univ. Braunschweig (Germany). Inst. fuer Elektrische Maschinen; Turki, Faical [Paul Vahle GmbH und Co. KG, Kamen (Germany)

    2012-07-01

    Supercapacitors have the ability to support the electricity grid by balancing voltage drops, net flicker and harmonics due to their high power density low reaction time. The task in order to have improved power quality relates in large extend by interchanging the electricity grid with real and imaginary power in short interval (milliseconds to seconds) of time. Because of quadratic relationship between voltage and stored energy a bidirectional buck-boost converter is required between energy storage and inverter. In the next step a dedicated controller has been built to couple an inverter with available three phase system 400 V - 50 Hz and it was put into operation. Another key point of this work is to determine the power and the energy content in the energy storage system to smoothen the grid. As an example here a load curve for a residential area has been considered. This load curve has to be smoothened for few minutes interval of time. With the help of cascade controller the energy content in the energy storage system, power for optimal utilization of energy content from storage can be controlled thus a reasonable grid smoothening can be realized. The described strategy tries to keep the energy content in the energy storage system constant for longer duration. Thus the required capacity of the energy storage system can be reduced and investment cost can also be reduced. The energy controller that functions as superimposed control loop gives reference input to control the complete system (Energy storage system, DC-DC converter and inverter). Different types of control methods are considered and their characteristics are simulated. In addition, the performance of total system (Energy storage system, DC-DC converter and inverter) for grid support during operation of Asynchronous machine using an example has been shown. Simulations have been made to support critical parallel operation of grid in period of milliseconds. A test bench has been made to verify the improvement in grid power quality by dynamically utilizing the double layer capacitors as energy storage system. The important results related to the topic ''Use of double layer capacitors for Grid Smoothening or Grid Support'' have been concluded. Finally the Potential of coupling electric vehicles with distributed generation is discussed. (orig.)

  6. Studies on the origin of neutron flux fluctuations- Final report; Untersuchungen der Ursachen fuer Neutronenflussschwankungen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Blaesius, Christoph; Herb, Joachim; Kuentzel, Matthias

    2016-01-15

    Aim of the project was to find possible explanations for the neutron flux fluctuations and their changes over the last decades in German PWR. Several models concerning thermal hydraulics, structural mechanics and neutron physics were evaluated. It was shown that up to now no models are available that could explain the observed phenomena. Future studies should focus on interdisciplinary coupling of different models.

  7. Neuere Untersuchungen zur Prädiktion von EEG-Signalen bei Epilepsie

    Directory of Open Access Journals (Sweden)

    C. Niederhöfer

    2007-06-01

    Full Text Available Seit einigen Jahren ist die Analyse von EEG-Signalen bei Epilepsie Gegenstand zahlreicher wissenschaftlicher Arbeiten; Zielvorstellung ist dabei die Entwicklung von Verfahren zur Erkennung eines möglichen Voranfallszustandes. Im Vordergrund steht beispielsweise die Approximation einer so genannten effektiven Korrelationsdimension, die Bestimmung der maximalen Lyapunov-Exponenten, Detektionsverfahren für Muster bei Zellularen Nichtlinearen Netzwerken, die Bestimmung der mittleren Phasenkohärenz und Verfahren zur nichtlinearen Prädiktion von EEG-Signalen. Trotz umfangreicher Bemühungen kann bis heute eine Erkennung von Anfallsvorboten mit einer Sensitivität und Spezifität, die eine automatisierte Anfallsvorhersage ermöglichen würde, noch nicht durchgeführt werden. In diesem Beitrag werden neue Ergebnisse zur Prädiktion von EEG-Signalen bei Epilepsie vorgestellt. Dabei werden Signale, welche mittels intrakranieller electrocorticographischer (ECoG und stereoelectroencephalographischer (SEEG Ableitungen registriert wurden, segmentweise analysiert. Unter der Annahme, dass sich Änderungen des Systems ,,Gehirn" als Änderungen im Prädiktor, d.h. in seinen Systemparametern widerspiegeln, könnte eine nähere Betrachtung der Prädiktoreigenschaften zu einer Erkennung von Anfallsvorboten führen.

  8. 'Vorwort' Themenheft Deutsche Sprache: 'Modifikation im Deutschen: Kontrastive Untersuchungen zur Nominalphrase'

    DEFF Research Database (Denmark)

    Gunkel, Lutz; Rijkhoff, Jan

    2010-01-01

    Das vorliegende Themenheft der Zeitschrift Deutsche Sprache versammelt vier Beiträge zu einem zentralen Thema der deutschen Grammatik und Textlinguistik: der Form und Funktion von Attributionsstrukturen in der Nominalphrase. Gemeinsam ist allen Beiträgen der kontrastive und/oder funktional...

  9. Untersuchungen zum in vivo Differenzierungspotenzial muriner und humaner hämatopoetischer sowie muriner neuraler Stammzellen

    OpenAIRE

    Harder, Friedrich

    2003-01-01

    Zusammenfassung Im Zuge der Säugerentwicklung entsteht aus der totipotenten Eizelle ein Organismus aus mehr als 200 verschiedenen Zelltypen. Dabei wird die Entwicklung und der Erhalt des Tieres von Stammzellen gewährleistet. Während der Embryonalentwicklung gibt es nur transient vorkommende Stammzelltypen, während der adulte Körper die Homoeostase mittels permanent vorhandener somatischer Stammzellen aufrechterhält. Als kennzeichnend für die somatischen Stammzellen galt, dass sie nur die Zell...

  10. Investigations of mercury concentrations in infant organs; Untersuchungen zur Quecksilberkonzentration in Organen von Kindern

    Energy Technology Data Exchange (ETDEWEB)

    Schlosser, C.

    2001-07-01

    Study of the mercury concentration of organs (kidneys, liver, brain, spleen, thyroid, pituitary gland, thymus) of 32 dead children, aged 0.1 - 15 years. Comparison with mercury concentration in adults. Emphasis is given on the role of dental amalgam. Study of age dependence of mercury contamination.

  11. Experiments on the identification of radiation processed foods. Untersuchungen zum Nachweis bestrahlter Lebensmittel

    Energy Technology Data Exchange (ETDEWEB)

    Delincee, H [Inst. fuer Ernaehrungsphysiologie, Bundesforschungsanstalt fuer Ernaehrung, Karlsruhe (Germany)

    1992-01-01

    The availability of reliable detection methods allowing to show directly in the traded food product whether it has been irradiated or not, will help to assure consumers that the inspection authorities are able to check the compliance with existing regulations effectively. Numerous analytical methods for the identification of radiation processed foods were investigated at the Federal Research Centre for Nutrition in Karlsruhe over the years. This report will mainly consider the measurement of chemi- and thermoluminescence of herbs and spices, since in many countries these products are most frequently irradiated food items. Following radiation processing, herbs and spices mostly increase their luminescence intensities. The luminescence response, however, varies considerably from one spice to another, and even among several batches of the same spice. Since nonirradiated products may also exhibit luminescence, the discrimination irradiated - non-irradiated is not that simple. Isolation of mineral dusts associated with the food and measurement of the thermoluminescence of these mineral fractions improves the identification of irradiated food. International collaboration will help to establish standardized and reliable analytical detection methods in the near future. (orig.)

  12. Investigation of new materials for SOFC applications; Untersuchungen zum Einsatz neuer Werkstoffe fuer SOFC-Anwendungen

    Energy Technology Data Exchange (ETDEWEB)

    Wackerl, J.

    2007-05-04

    Fuel cells based on solid oxides ('SOFC') are excellent alternative devices for power generation, when they are operated at high temperature, e.g. above 600 C. Having only fixed parts for the power generating part of the device is only one advantage of the fuel cell. Due to their unique design, these devices offer a maximum of efficiency for energy conversion compared to conventional power generating systems, which are mainly based on turbines. One aim of this thesis is the examination of alternative electrolyte and cathode materials for the SOFC applications at reduced temperatures, which means in the temperature range between 600 C and 750 C. For the first main task, several materials from the oxygen ion conducting electrolytes were selected. Different strontium and magnesium doped lanthanum gallate (LSGM) materials with additional transition metal doping were selected and prepared via two different preparation methods. The optimum calcining conditions were determined using thermal analysis methods. The results of the structural analysis of the sintered electrolyte materials were used to select the most suitable electrolyte materials. As a result, LSGM and iron doped LSGM (LSGMF) were the most promising materials. Further investigations were carried out on LSGMF materials with different strontium content. The influence of chemical cation non-stoichiometry on the perovskite material was investigated. Therefore, measurements to gather information about the crystallographic structure, morphology, electrochemistry and electrical conductivity were carried out. For a selected sample, the correlations between single effects, such as the crystallographic structure, and the electrical properties are shown by combining the different analysis methods. It could be shown that both the electrochemistry and the crystallographic structure have a significant influence on the electrical conductivity of the LSGMF materials. The second aim of the thesis was the selection and preparation of suitable cathode materials for the SOFC operated at reduced temperatures. The focus for this selection was laid on the chemical compatibility with LSGMF and Scandia doped yttria (ScSZ) based electrolyte materials. Most of the cathode materials could be prepared single phased, with the exception of a strontium doped lanthanumcuprate and a strontium doped lanthanumnickelate. The third aim of the thesis was the investigation of the chemical compatibility between the prepared cathode materials and the electrolyte materials ScSZ and LSGM. The combinations of electrolyte-cathode materials were annealed at commonly used co-sintering temperatures but for extended sintering times. X-Ray diffraction patterns (XRD) and scanning electron microscopy (SEM) were used for the investigation. Based on the examination of the appearing primary and secondary phases and the morphology a ranking of the combinations is given. The least chemical reactions with both electrolyte materials were observed for a strontium doped lanthanum manganite. However, a strontium and copper doped lanthanumferrite seems to be the most promising cathode material for reduced temperatures. (orig.)

  13. Studies on mechanisms of the laser particle acceleration; Untersuchungen zu Mechanismen der Laser-Teilchenbeschleunigung

    Energy Technology Data Exchange (ETDEWEB)

    Aurand, Bastian

    2012-06-20

    Within the last decade, many developments towards higher energies and particle numbers paved the way of particle acceleration performed by high intensity laser systems. Up to now, the process of a field-induced acceleration process (Target-Normal-Sheath-Acceleration (TNSA)) is investigated the most. Acceleration occurs as a consequence of separation of charges on a surface potential. Here, the broad energy spectrum is a problem not yet overcome although many improvements were achieved. Calculations for intensities higher than 10{sup 20..21} W/cm{sup 2} give hint that Radiation-Pressure-Acceleration (RPA) may lead to a sharper, monoenergetic energy spectrum. Within the framework of this thesis, the investigation of the acceleration mechanism is studied experimentally in the intensity range of 10{sup 19} W/cm{sup 2}. Suitable targets were developed and applied for patent. A broad range of parameters was scanned by means of high repetition rates together with an adequate laser system to provide high statistics of several thousands of shots, and the dependence of target material, intensity, laser polarisation and pre plasma-conditions was verified. Comparisons with 2-d numeric simulations lead to a model of the acceleration process which was analyzed by several diagnostic methods, giving clear evidence for a new, not field-induced acceleration process. In addition, a system for a continuous variation of the polarization based on reflective optics was developed in order to overcome the disadvantages of retardation plates, and their practicability of high laser energies can be achieved.

  14. Analysis of the individual radio sensitivity of breast cancer patients; Untersuchungen zur individuellen Strahlenempfindlichkeit von Brustkrebspatientinnen

    Energy Technology Data Exchange (ETDEWEB)

    Auer, Judith

    2013-04-04

    Individual radiosensitivity has a crucial impact on radiotherapy related side effects. A prediction of individual radiosensitivity could avoid these side effects. Our aim was to study a breast cancer collective for its variation of individual radiosensitivity. Peripheral blood samples were obtained from 129 individuals. 67 breast cancer patients and 62 healthy and age matched individuals were looked at and their individual radiosensitivity was estimated by a 3-color Fluorescence in situ hybridization approach. Blood samples were obtained (i) before starting adjuvant radiotherapy and were in vitro irradiated by 2 Gy; (ii) after 5 single doses of 1.8 Gy and after 72 h had elapsed. DNA of lymphocytes was probed with whole chromosome painting for chromosomes 1, 2 and 4. The rate of breaks per metaphase was analyzed and used as a predictor of individual radiosensitivity. Breast cancer patients were distinctly more radio-sensitive compared to healthy controls. Additionally the distribution of the cancer patients' radiosensitivity was broader. A subgroup of 9 rather radio-sensitive and 9 rather radio-resistant patients was identified. A subgroup of patients aged between 40 and 50 was distinctly more radio-sensitive than younger or older patients. The in vivo irradiation approach was not applicable to detect individual radiosensitivity. In the breast cancer collective a distinctly resistant and sensitive subgroup is identified, which could be subject for treatment adjustment. Especially in the range of age 40 to 50 patients have an increased radiosensitivity. An in vivo irradiation in a breast cancer collective is not suitable to estimate individual radiosensitivity due to a low deposed dose.

  15. Analysis of aerosol deposition within EGR-heat exchangers; Untersuchungen zur Aerosolabscheidung in AGR-Waermetauschern

    Energy Technology Data Exchange (ETDEWEB)

    Hoernig, Gabriele Theresia Maria

    2012-04-17

    Cooled exhaust gas recirculation is a very effective way to reduce nitrogen oxide emissions in diesel exhaust gases. Due to the conditions present in the cooler and the given exhaust gas composition, deposits are formed on the gas-side cooler wall which reduces the cooling capacity of the device. For the work at hand, extensive experimental series using a model test bench as well as analysis of the deposits were conducted. Furthermore calculations of the mechanisms (e.g. thermophoresis and diffusiophoresis) were performed. The results of the experiments and calculations serve as a base for recommendations for cooler operating conditions under which fouling is minimized.

  16. Implementierung, Evaluation und vergleichende Untersuchungen des Powerplex 16 Systems zur quantitativen Chimärismusanalyse

    OpenAIRE

    Joachim, Stefanie

    2010-01-01

    Die allogene Stammzelltransplantation ist ein Verfahren zur Therapie verschiedener maligner und nicht-maligner hämatologischer Erkrankungen. Da es sich um eine sehr aufwendige Therapie handelt, sind Methoden, die den Behandlungsverlauf dokumentieren, wie minimale Resterkrankung und Chimärismusanalyse, essentiell. Eine nach Stammzelltransplantation vollständig vom Spender abgeleitete Hämatopoese ist Voraussetzung für das Engraftment und die Prophylaxe eines Rezidivs der zugrundeliegenden Er...

  17. Untersuchungen zum Riechvermögen bei Patienten mit schizophrenen Störungen

    OpenAIRE

    Minovi, A; Dombrowski, T; Brüne, M; Dazert, S; Juckel, G

    2014-01-01

    Einleitung: Riechstörungen werden bei Patienten mit einer Schizophrenie in vielen Studien beschrieben. Im Rahmen einer prospektiv angelegten Studie untersuchten wir das Riechvermögen von 18 Patienten mit einer Schizophrenie im Vergleich zu einer Kontrollgruppe (n=13). Weiterhin erfolgte eine immunhistochemische Untersuchung der Riechschleimhaut bei 8 Patienten mit einer Schizophrenie.Methoden: Die Riechprüfung erfolgte mit Hilfe der erweiterten Sniffin' Sticks-Testbatterie. Nach Biopsie der...

  18. Untersuchungen zur oxidativen Bildung von Stickstoffmonoxid in Pflanzen sowie zur Visualisierung von Stickstoffmonoxid mittels Fluoreszenzfarbstoffen

    OpenAIRE

    Rümer, Stefan

    2013-01-01

    Stickstoffmonoxid (NO) ist ein gasförmiges, relativ stabiles Radikal, das in Pflanzen u. a. durch Reduktion aus Nitrit unter Katalyse des Enzyms Nitratreduktase gebildet wird. In tierischen Organismen wird NO dagegen über einen oxidativen Syntheseweg aus der Ami-nosäure L-Arginin katalysiert durch verschiedene Isoformen der NO-Synthasen (NOS) hergestellt. Es besitzt im tierischen System vielfältige Funktionen u. a. als Neurotransmitter sowie Blutfluss und -druck regulierendes Agens. Im Pflanz...

  19. Analysis to long-term stability of solar cables; Untersuchungen zur Langzeitstabilitaet von Solarleitungen

    Energy Technology Data Exchange (ETDEWEB)

    Funtan, P.

    2005-07-01

    For the moment it is not possible to say anything about the long-term stability of solar cables. Own experiences shows, that the rubber solar cable H07 RN-F (of one manufacturer) is not qualified for installations, longer than 10 years. The outer isolation of the cable first shows embrittlements and later deep cracks. Microscopically analysis confirms this. Measurements of temperature in typical installation areas of solar cables also shows, that the influence of temperature, regarding aging plays not the most important role, when the cable is installed in a sun protected position. Up to now the reason of the cable destruction is not definitely clarified. Chemically analysis of a damaged and an intact part of the cable, which was installed inside of a module junction box (reduced humility), shows no differences in the chemical consistence. It seems, that it is a combinated effect of temperature and humidity. Further analysis will be performed. (orig.)

  20. Vergleichende Untersuchungen zum Verbund von Cobalt-Basis-Legierungen und Metall-Keramik-Verbundsystemen

    OpenAIRE

    Herms-Westendorf, Lea Maria

    2017-01-01

    This thesis aims to answer the question: Does the use of bonding agents and cobalt chromium alloys with variable degrees of rigidity have an effect on the bonding strength of metal fused to ceramic systems? The 3 point flexural test of SCHWICKERATH (DIN EN ISO 9693) served as the basis for the studies. Test samples included omitting or including the bonding agent NP Bond® (VITA) and choosing either a more stable (Wirobond® 280) or more flexible dental alloy (Wirobond® C) (BEGO). The used c...

  1. Untersuchungen zum Einfluss einer Air-Liquid-Interphase auf die Differenzierung von Alveolarepithelzellen Typ II

    OpenAIRE

    Sinis, Nektarios

    2003-01-01

    Die Dedifferenzierung der Alveolarepithelzellen Typ II stellt in vitro ein großes Problem dar. Zellen, die länger als 48 Stunden in vitro kultiviert werden tendieren zu einer Dedifferenzierung. Die vorliegende Arbeit stellt ein Air-Liquid-Interphasesystem zur Kultivierung von TypII-Zellen vor. Hierdurch ist es uns gelungen TypII-Zellen über einen Zeitraum von bis zu 14 Tagen in vitro auf einem hohen Grad der Differenzierung zu konservieren. Zellen die nicht so kultiviert wurden zeigten fr...

  2. Monika Elisabeth Bründl. Lexikalische Dynamik: Kognitiv-linguistische Untersuchungen am englischen Computerwortschatz

    Directory of Open Access Journals (Sweden)

    Michael Klotz

    2011-10-01

    Full Text Available Nowhere is the dynamic character of the English lexicon more apparent than in the case of computer vocabulary. Elisabeth Bründl's study investigates this field with two aims in mind (as pointed out in chapter one: firstly, the author wants to find out which principles underlie the creation of words in this field; secondly, her study aims at the integration of cognitive insights into the tradi-tional field of lexicology.

  3. Untersuchungen der Behandlung des Schlagwerks in den Kompositionen von Younghi Pagh-Paan

    OpenAIRE

    Kang, Unsu

    2007-01-01

    This is the research of korean composer, Younghi Pagh-Paan, who is living in Germany and is working as a professor at Bremen Art University. The focus especially is made on her musical treatment of the percussion instruments, because it always has connection with her korean nationality, which means the usage of korean traditional rhythms, tone colors and the instruments. My reserch begins with this questions, especially what musical influences does she have from her childhood and how did she ...

  4. Experimentelle, analytische und numerische Untersuchungen des Rührreibschweißprozesses

    OpenAIRE

    Hoßfeld, Max

    2016-01-01

    Mit dem Rührreibschweißverfahren steht seit einigen Jahren eine Fügetechnologie zur Verfügung, mit der viele fügetechnische Problemstellungen speziell beim Fügen von Aluminiumlegierungen gelöst oder vermieden werden können. Mittels Rührreibschweißen können sämtliche Aluminiumlegierungen zuverlässig, hocheffizient und mit einem sehr hohen Verbindungswirkungsgrad gefügt werden. Dabei weisen rührreibgeschweißte Verbindungen bereits ohne Nachbehandlung sehr gute statische und zyklische Festigkeit...

  5. Untersuchungen zur fließregulierenden Eigenschaft hochdisperser Fällungskieselsäuren

    OpenAIRE

    Müller, Anne-Kathrin

    2008-01-01

    Es wurde untersucht, welchen Einfluss verschiedene hochdisperse Fließregulierungsmittel, wie sie bisher in der pharmazeutischen Technologie aber auch in der Lebensmittel- und Futtermittelindustrie eingesetzt werden, auf einige ausgewählte kohäsive Schüttgüter ausüben. Dazu wurden binäre Mischungen mit variierender Konzentration an Fließregulierungsmittel und Schüttgut hergestellt und in einem Freifallmischer gemischt. Als Fließverbesserer kamen verschiedene hochdisperse Kieselsäuren, darunter...

  6. Investigation of hydrogen recombination under natural convection conditions; Untersuchungen zur Wasserstoffrekombination unter Naturkonvektionsbedingungen

    Energy Technology Data Exchange (ETDEWEB)

    Simon, Berno

    2015-09-04

    Passive Autocatalytic Recombiners (PAR) are installed inside the containment of nuclear power plants in order to prevent the build-up of flammable mixtures and to mitigate the effects of hydrogen deflagrations, which can occur in the event of a severe accident combined with the release of hydrogen. In order to simulate the operating behaviour of PARs, the computer program REKO-DIREKT is being developed at the Forschungszentrum Juelich in collaboration with the Institute for Reactor Safety and Reactor Technology at the RWTH Aachen. For the validation of the code, data from experimental facilities operated at Juelich are used. This work focusses on the analysis of the chimney effect through the PAR housing as well as the optimization of the chimney model of REKO-DIREKT. Therefore experimental investigations are carried out in the REKO-4 facility under natural convection conditions. This facility is equipped with numerous measuring devices, e.g. katharometers for in-situ measuring of the hydrogen concentration and the optical flow measurement technique Particle-Image-Velocimetry. In preliminary assessments the equipment is being qualified in order to determine the measurement accuracy. In the following experimental investigations, a small-scale PAR is used, that is built in a modular way allowing it to be equipped with different chimney geometries. The experimental results produce a database that shows the central correlation between the hydrogen concentration, the catalyst temperature and the inlet velocity. The results include the variation of the recombiner's chimney height and experiments at different operating pressures. After optimization of the chimney model, the simulation program is validated against experiments in the large-scale facility THAI in Eschborn, which have been performed subsequent to this thesis in the context of the OECD/NEA-THAI project. Finally, the influence of a downward-directed, near-wall flow on the operational behaviour of the small-scale PAR is investigated. The goal is to analyse, whether or not externally induced flow regimes are able to influence the start-up and operational behaviour of PARs. The results show that downward directed flow conditions may influence the operational behaviour and reduce the efficiency of a recombiner, if the flow through the chimney is not prevented by the outlet design.

  7. Analyses of functional brain connectivity; Untersuchungen zur funktionellen Konnektivitaet des Gehirns

    Energy Technology Data Exchange (ETDEWEB)

    Stephan, K.E.

    2003-03-01

    This dissertation includes two independent studies that investigate two complementary aspects of functional connectivity in the Macaque and the human brain. In the first study, a computational meta-analysis of published electrophysiological data on context-independent functional brain connectivity was conducted by means of three independent methods. The second study investigated the effects of the atypical antipsychotic substance olanzapine on the functional connectivity of the cerebellum during a simple motor task (self-paced finger tapping). Six schizophrenic patients and six control subjects matched for age and sex were investigated by functional magnetic resonance imaging (fMRI) twice. This study provided the first experimental data on the effects of atypical antipsychotic agents on functional brain connectivity and demonstrated pronounced olanzapine-dependent changes of functional couplings between cerebellum, thalamus, and prefrontal cortex. (orig.) [German] In der hier vorgelegten Arbeit werden zwei komplementaere Aspekte der funktionellen Konnektivitaet - im Gehirn des Makaken und Menschen anhand zweier separater Studien untersucht. In der ersten Studie wurde mittels dreier unabhaengiger Methoden eine Metaanalyse publizierter elektrophysiologischer Daten zur kontextunabhaengigen funktionellen Konnektivitaet des Makakenkortex durchgefuehrt. Diese Studie erbrachte damit zum ersten Mal den Nachweis einer funktionellen Small World-Netzwerkstruktur des Primatenkortex. In der zweiten Studie wurde der Effekt des atypischen Neuroleptikums Olanzapin auf die funktionelle Konnektivitaet des Zerebellums im Kontext einer einfachen motorischen Aufgabe (selbstgesteuertes Fingertrapping) untersucht. Sechs schizophrene Patienten, die Neuroleptika-naiv bzw. -entwoehnt waren, sowie sechs alters- und geschlechtsentprechende Kontrollprobanden wurden im Abstand von jeweils drei Wochen mit funktioneller Magnetresonanztomografie (fMRT) untersucht. Diese Studie lieferte die ersten experimentellen Befunde zum Einfluss atypischer Neuroleptika auf die funktionelle Konnektivitaet des Hirns ueberhaupt und wies deutliche medikationsbedingte Kopplungsveraenderungen zwischen Zerebellum, Thalamus und praefrontalem Kortex bei schizophrenen Patienten nach. (orig.)

  8. Experimentelle Untersuchungen zur Verteilung endokriner Stoffe auf Boden/Wasser- Systeme.

    OpenAIRE

    Kohne, Danuta

    2010-01-01

    Unter „endokrinen Stoffen“ (Endocrin Disruptors) versteht man synthetisch erzeugte und in die Umwelt gelangte Chemikalien, die in die hormonellen Regelkreise von Mensch und Tier eingreifen. Sie entfalten ihre Wirkung i. d. R. bereits bei geringer Konzentration. Die aus der Einwirkung solcher Stoffe resultierenden negativen Folgen (z. B. Wachstumsstörungen, sinkende Fruchtbarkeit) werden unter dem Begriff „endokrine Effekte“ zusammengefasst. Die Untersuchung endokriner Effekte von Chemikalien ...

  9. Mineralogical investigations into ash deposits of selected brown coals; Mineralogische Untersuchungen an Ascheansaetzen ausgewaehlter Braunkohlen

    Energy Technology Data Exchange (ETDEWEB)

    Szilagyi, J.; Ullrich, B. [Technische Univ. Dresden, Inst. fuer Geotechnik (Germany)

    2003-07-01

    Within the framework of the research project financed by the Arbeitsgemeinschaft industrieller Forschungsvereinigungen (AIF) ''Experimental investigations into the formation of ash deposits from stack gases during the combustion of pulverised lignite'' and supervised by the chair of power station technology (Institute of Energy Technology) of the Dresden Technical University, the mineral composition of ash deposits of six different coals were investigated: two coal blends (different countries worldwide), two lignites from east from the River Elbe (types WM and JAe), one from west of the River Elbe and one Rhenish lignite. (orig.)

  10. Zur methodik der ninhydrinreaktion und papierchromatographie im zusammenhang mit untersuchungen uber gerinnungsphysiologisch interessierende phosphatide

    NARCIS (Netherlands)

    Hecht, E.; Mink, C.

    1952-01-01

    In view of other researches, the authors have studied the ninhydrin reaktion in order to obtain evidence of free amino-N of phosphatides and their fission products. Apart from the study of paper chromatography of nitrogenated lipoids, the details of general interest are given of the technique

  11. Research about the hydrazine-ammonia system. Untersuchungen am system hydrazin-ammoniak

    Energy Technology Data Exchange (ETDEWEB)

    None

    1967-03-15

    Some qualities of hydrazine-ammonia mixtures are investigated with regard to their use as rocket fuels by means of conventional measuring methods being adapted to the problems of these systems vapor pressures, densities and viscosities of such mixtures are determined as functions of compositions. The findings of these studies show in view to vapor pressure and densities deviations from ideal behavior, which are however, of disadvantage when using this system as fuel for rocket engines.

  12. Magnetooptical investigations on ferromagnetic III-V-semiconductors; Magnetooptische Untersuchungen an ferromagnetischen III-V-Halbleitern

    Energy Technology Data Exchange (ETDEWEB)

    Winter, Andreas

    2009-07-23

    Magnetooptical Kerr effect (MOKE) and Magnetic Circular Dichroism (MCD) have been used to investigate magnetic as well as bandstructure properties of diluted magnetic III-V-semiconductors containing Mn. In these ferromagnetic systems it has been found that the strength of the observed effects depends linearly on the magnetization of the samples with no influence of the external magnetic field. The magnetooptical effects allowed the recording of hysteresis loops of GaMnAs, GaMnSb, InMnAs and InMnSb samples for different temperatures and in the case of GaMnAs also for different alignments of the external magnetic field with respect to the easy axis of magnetization. The Stoner-Wohlfahrt-Model has been used to describe the resulting shapes of the loops yielding the magnetic anisotropy parameters of the samples. For magnetically saturated samples, spectra of MOKE and MCD have been recorded. Contrary to pure III-V-semiconductors, which exhibit lots of sharp resonances due to interband transitions between Landau levels, III-Mn-V-semi-conductors how only very few (or just one) considerably broad resonance(s). Their spectral position(s) do(es) neither depend upon the magnetic field as it would be the case for pure III-V-semiconductors nor the magnetization. Only the amplitude increases linearly with the magnetization. Utilizing a kp-theory it has been possible to describe the observed dependencies. Valence- and conduction-band are split into Landau levels by the external magnetic field and, in addition to the Zeeman-effect, the spin-levels are split by the exchange interaction between the localized electrons of the Mn ions and the free carriers which is proportional to the magnetization of the samples. This splitting is much bigger than the Landau level splitting. Due to an inhomogeneous distribution of the Mn ions and due to the high carrier density the Landau levels are strongly broadened and their structure is not observable. Owing to the high carrier-concentration in III-Mn-V-semiconductors the Fermi-level is located far below the edge of the valence band and therefore optical transitions between different valence band levels are possible (which is not the case for pure III-V-systems). These transitions exhibit large transition rates and dominate the observed effects. Because all Landau levels in the valence band are shifted in the same direction by the external magnetic field the energy-differences for the transitions mostly do not change with the external field. The large exchange induced splitting between quasi continua of Landau states with different spin orientation which is proportional to the magnetization separates the transition energies for left and right hand circularly polarized light and thereby generates the observed magnetooptical effects. By fitting the aforementioned kp-theory to the experimental data it has been possible to determine the absolute value of the exchange integral between localized electrons in the Mn-ions and the free holes. (orig.)

  13. Untersuchungen zu mummy, kette und Interaktionspartnern bei der Entwicklung des Drosophila Nervensystems

    OpenAIRE

    Strunk, J.M. (Judith)

    2006-01-01

    Die Dissertation beinhaltet genetische, funktionelle und phänotypische Analysen von Mutationen, die zu Defekten der Musterbildung des embryonalen ZNS von Drosophila melanogaster führen. Das Gen mummy wurde im Bereich 26D7 lokalisiert und codiert eine UDP-N-ACETYLGLUCOSAMIN-PYROPHOSPHORYLASE. MUMMY katalysiert eine Reaktion, deren Produkt, das UDP-N-Acetylglucosamin, Grundbaustein für Glycosylierung und GPI-Ankersynthese ist. Effekte von mummy auf diese Prozesse konnten dargestellt werden. Für...

  14. Untersuchungen zum Einfluss der Betriebsbedingungen auf die Schädigung und Instandhaltung von Turboluftstrahltriebwerken

    OpenAIRE

    Müller, Matthias H.

    2013-01-01

    Langfristige Instandhaltungsverträge und der anhaltende Kostendruck haben die Notwendigkeit einer zuverlässigen Vorhersage und einer Reduzierung der Kosten für die Instandhaltung von Turboluftstrahltriebwerken zur Folge. Die Instandhaltungsbedürftigkeit und Zuverlässigkeit von Turboluftstrahltriebwerken wird wesentlich durch die betreibertypischen Betriebsbedingungen und die auftretenden Schädigungsmechanismen beeinflusst. Der Verlauf der Bauteilschädigung wird neben den Betriebsbedingungen d...

  15. Studies on the preparation of low-carrier Se-73,75 tracers for in vivo examinations; Untersuchungen zur Darstellung traegerarm 73,75Se-markierter Tracer fuer in vivo Untersuchungen

    Energy Technology Data Exchange (ETDEWEB)

    Helfer, Andreas

    2013-04-03

    With the growing importance of positron emission tomography (PET) for in vivo imaging in diagnostic medicine there is great interest of developing new labelling methods for the positron emitter selenium-73. As attractive application an examination of a no-carrier-added (n.c.a.) preparation of the analogous tracer Sulindac Selenid and of the selenium containing compound Ebselen was examined with {sup 73,75}Se. First of all a labelling strategy for Sulindac Selenid based on a protected precursor was developed. This precursor should further be transformed into the corresponding standard compound for chomatographic identification of the n.c.a. product. This, however, was not possible. An alternative synthesis method also did not result in a product. Thus, a radioactive labelling in case of Sulindac Selenid was not indicated in spite of a successful synthesis of a precursor. The preparation of Ebselen was performed as earlier described by a sequential one-pot synthesis with a yield of 46 %. An adaption of the reaction parameters to a radiosynthesis with {sup 75}Se failed on the n.c.a. state and also after adding carrier to the reaction mixture. The desired product could, however, be prepared in a copper catalysed one-pot radiosynthesis for the first time under carrier-added conditions. Here, optimized conditions resulted in radiochemical yields of 60 ± 18 %. A no-carrier-added product could finally be achieved using sulphur as nonisotopic carrier in the reaction mixture. After optimisation of reaction parameters n.c.a. [{sup 75}Se]Ebselen could be synthesized with radiochemical yields of 55 ± 7 % within 4 h. Furthermore the desired product could be separated by RHPL-chromatography from its co-produced sulfur-analogue. After transferring the conditions to radiosyntheses with the positron emitter {sup 73}Se, n.c.a. [{sup 73}Se]Ebselen could be achieved with a radiochemical yield of 22 ± 1 % and can now be used as a potential radiotracer in preclinical evaluation studies with respect to tracer application with PET. First in vitro distributions studies with slices of rat brain were already performed by autoradiography.

  16. Controlled composting of waste wood contaminated with PAH; Untersuchungen zur gesteuerten Rotte von mit polyzyklischen aromatischen Kohlenwasserstoffen (PAK) kontaminiertem Altholz

    Energy Technology Data Exchange (ETDEWEB)

    Ulbricht, H.

    2002-07-01

    The author investigated the potential and limits of microbial pollutant degradation in PAH-polluted waste wood by composting. The conditions in which autochthonic micro-organisms are able to decomposite the PAH contained in wood by solid phase fermentation were investigated. The focus was on phenanthrene, anthracene and pyrene, all of which are used as protective materials (disinfestants) for wood. The results were verified on contaminated waste wood, including an analytical investigations of decomposition of PAH of the EPA catalogue. Boundary conditions for achieving high rates of PAH decomposition were investigated. [German] Generelles Ziel der Arbeit war die Untersuchung der Moeglichkeiten und Grenzen des mikrobiellen Schadstoffabbaus in PAK-belastetem Altholz durch Kompostierung und die Pruefung auf Anwendbarkeit der Erkenntnisse in technischen Verfahren. In der vorliegenden Arbeit wurde untersucht, unter welchen Bedingungen die autochthonen Mikroorganismen in der Lage sind, an das Holz gebundene PAK durch Feststofffermentation abzubauen. Als Schwerpunkt wurde zunaechst der Abbau der im zum Holzschutz verwendetem Teeroel vorkommenden PAK Phenanthren, Anthracen und Pyren untersucht. Eine Verifizierung der Ergebnisse erfolgte mit real kontaminiertem Altholz, dabei wurde der Abbau der PAK der EPA-Liste analytisch verfolgt. Es sollten geeignete Randbedingungen gefunden werden, um im Festphasensystem hohe Abbauraten der PAK zu erreichen. (orig.)

  17. Investigation on application properties of liquid fuels with biogenic compounds; Untersuchungen zu anwendungstechnischen Eigenschaften fluessiger Brennstoffe mit biogenen Anteilen

    Energy Technology Data Exchange (ETDEWEB)

    Neulen, Martin [OWI Oel-Waerme-Institut GmbH, Aachen (Germany); Hoffmann, Hajo

    2013-10-01

    Within a DGMK project (DGMK 729) a test rig was developed in which fuel can be aged semi realistically to test additives, components from middle distillate devices, fuel components and the fuel itself. The test rig is designed as a hardware-in-the-loop test rig. The test rig's design allows a high flexibility in setting aging parameters. In contrast to other, similar test rigs, the aging parameters can be set in a very defined way. Test runs were already conducted with variations in temperature, operating cycles or pressing dry air in fuel or using nitrogen in order to eliminate the ambient air. It could be shown, that higher temperatures can age the fuel faster than lower temperatures, which was expected. Pressing air into the fuel extended the time needed to reach the abort criterion. Using nitrogen in order to reduce the influence of ambient air showed no effect on the duration of the test run. The effects of both settings - pressing air in the fuel and reducing the effect of ambient air by nitrogen - cannot be explained entirely yet. (orig.)

  18. Investigations of the EPR reference concept (KATS experiments); Untersuchungen zum EPR-Referenz-Konzept (KATS-Experimente)

    Energy Technology Data Exchange (ETDEWEB)

    Fieg, G.; Werle, H.; Huber, F.

    1995-08-01

    The reference concept of an EPR core catcher envisages the spreading of the melt on a protective layer (150 m{sup 2} area) and water cooling from above. Two variants are considered: Spreading on a dry area and on an area covered by water of condensation (1 cm depth). For the reference concept the KATS experiments are performed with thermite melts. After initial problems had rendered it difficult to interprete the first test, repeated tests have been successful. (orig.)

  19. Untersuchungen der Narbenqualität nach unterschiedlichen Verfahren des Wundverschlusses und der Wundbehandlung durch autologe Hauttransplantation

    OpenAIRE

    Zeplin, Philip Helge

    2005-01-01

    Die qualitative und quantitative Narbenqualitätsmessungen im Verlauf der Wundheilung ist von großer Bedeutung, da durch sie Einflussgrößen, die mit hoher Wahrscheinlichkeit zu pathologischen Narbenformationen führen, frühzeitig erkannt werden könnten und Rückschlüsse auf die jeweils angewandten Techniken und Materialien zulassen würden. Dass für die Analyse der Heilung von Schnitt- und Defektwunden objektive Messungen unabdingbar sind, sollte am Beispiel des Göttinger Miniaturschweins gezeigt...

  20. Untersuchungen zur Morphologie und Systematik der Vögel, zugleich ein Beitrag zur Anatomie der Stützund Bewegungsorgane

    NARCIS (Netherlands)

    Fürbringer, Max

    1888-01-01

    Die im Vorhergehenden beschriebenen Aberrationen der Mm. cucullaris, serratus superficialis, pectoralis, biceps, latissimus dorsi und deltoides vertheilen sich vornehmlich: A. auf das Propatagium, B. auf das Metapatagium und C. auf die Haut und Fascie der Schulter, der Brust und des Rückens, soweit

  1. Nuclear-spectroscopic studies in the {sup 132}Sn region; Kernspektroskopische Untersuchungen in der {sup 132}Sn-Region

    Energy Technology Data Exchange (ETDEWEB)

    Arndt, Oliver

    2007-10-15

    In this work investigations on r-process nuclides around the N = 82 shell closure are done. The so far unknown half-lives and P{sub n}-values of {sup 137-139}Sb and {sup 139}Te and their impact to r-process theory are given. Further the results of Shergur et. al. of neutron rich tin ({sup 137,138}Sn) are verified and in some points improved. New data on {gamma}-decay spectroscopy for {sup 136}Sn from single spectra is published. To improve beam quality and solve long known problems on ISOL-facilities with isobaric contamination, new techniques are discussed. A special focus is on molecular sidebands, which is first time adapted to a target/ion source unit in a mass separation facility. It was possible to create a strong SnS{sup +} sideband and in this way to reduce isobaric background with good beam intensities. On the other hand, a target with temperature controlled transfer line was build and its characteristics are discussed. To improve selectivity of a given experiment on neutron rich nuclei a new detector system for n{gamma}-coincidences was developed. Due to a special electronically setup of the new system it was possible to downsize the coincidence window compared to earlier attempts. (orig.)

  2. Experiments and CFD simulations of DTBP pool fires; Experimentelle Untersuchungen und CFD-Simulationen von DTBP-Poolfeuern

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Hyunjoo

    2007-07-01

    Flammable liquids are used increasingly often world-wide. Their storage, transport and chemical reactions are a considerable safety problem in industrial plants. Heat release and combustion products of big fires are a high hazard for persons, the immediate vicinity and the environment in general. Investigations of pool fires were carried out for a realistic assessment of the potential hazards to persons and plants in the immediate vicinity. Most of the available data on fire effects, safety distances and other measures relevant to fire protection are for hydrocarbons, alcohols and liquefied gases. LIttle is known on pool fires of liquid organic peroxides, which have quite different combustion characteristics with higher mass burnup rates and higher heat emissions into the vicinity. The dissertation presents experiments to characterize the combustion characteristics of organic peroxides as a function of the pool diameter. Di-tert-butylperoxide (DTBPL) was chosen for the experiments because it has a relatively high thermal stability as compared to other organic peroxides. Mass burnup rates, flame temperatures, the surface emissive power (SEP), the strength of thermal radiation and the flame length were measured as a function of the pool diameter. Further, parameters required for CFD simulations of DTBP pool fires were identified experimentally in order to ensure realistic modelling of real fires as a basis, e.g., for assessing safety distances. Experiments on large pool fires are costly and require much equipment and technical preparations so that fires are limited to pool diameters of only a few meters as a rule. CFD simulations would be capable of improving the prediction of safety-relevant parameters like flame temperature, surface emissive power, radiation strength and flame length without limiting the pool diameter or the fuel volume. Appropriate sub-models were used for modelling pool fires of organic peroxides, and the simulation results were critically evaluated and compared with experimental data. (orig.)

  3. Investigation of contaminated soil and water samples and their affirmativeness. Untersuchungen kontaminierter Boden- und Wasserproben und deren Aussagekraft

    Energy Technology Data Exchange (ETDEWEB)

    Brauch, H J; Eisenmann, R [Karlsruhe Univ. (T.H.) (Germany, F.R.). DVGW-Forschungsstelle am Engler-Bunte-Institut

    1989-09-01

    Contaminations in gas utility premises are a potential pollution hazard; hence, ground water, soil air and soil need to be tested. The authors describe major requirements for such analyses. Soil samples are a specific problem due to the heterogeneity of the material which can be solved only by performing a very great number of individual measurements. This is demonstrated by examples from practice. The existing limits are not suitable for a hazard assessment of gasworks-typical contaminations. Schematic application of standard value recommendations like the 'Dutch List' and their abuse as a compilation of limits should be rejected. (orig.).

  4. Investigations of the surface tension of coal ash slags under gasification conditions; Untersuchungen zur Oberflaechenspannung von Kohleschlacken unter Vergasungsbedingungen

    Energy Technology Data Exchange (ETDEWEB)

    Melchior, Tobias

    2011-10-26

    In the context of CO{sub 2}-emission-induced global warming, greenhouse gases resulting from the production of electricity in coal-fired power plants gain increasing attention. One possible way to reduce such emissions is to gasify coal instead of burning it. The corresponding process is referred to as Integrated Gasification Combined Cycle and allows for the separation of CO{sub 2} before converting a synthesis gas into electrical energy. However, further improvements in efficiency and availability of this plant technology are needed to render the alternative generation of electricity sensible from an economic point of view. One corresponding approach introduces hot gas cleaning facilities to the gasification plant which guarantee a removal of slag particles from the synthesis gas at high temperatures. The development of such filters depends on the availability of data on the material properties of the coal ash slags to be withdrawn. In this respect, the surface tension is a relevant characteristic. Currently, the surface tension of real coal ash slags as well as of synthetic model systems was measured successfully by means of the sessile drop and the maximum bubble pressure method. With regard to the sessile drop technique, those experiments were conducted in a gasification-like atmosphere at temperatures of up to 1500 C. Furthermore, the pressure inside the experimental vessel was raised to 10 bar in order to allow for deriving the influence of this variable on the surface tension. In contrast, maximum bubble pressure trials were realised at atmospheric pressure while the gas atmosphere assured inert conditions. For performing sessile drop measurements, a corresponding apparatus was set up and is described in detail in this thesis. Three computer algorithms were employed to calculate surface tensions out of the photos of sessile drops and their individual performance was evaluated. A very good agreement between two of the codes was found while the third one produces heavily scattering output. The measurement arrangement was run in an almost fully automated fashion which resulted in an immense amount of obtained surface tension data. Maximum bubble pressure experiments were conducted at the University of Osaka, Japan, on selected real ash samples. Due to a far longer time required for determining bubble pressures in comparison to taking drop pictures, only a small number of temperatures could be studied abroad. The results show the surface tension to be in the range from 200 mN/m to 500 mN/m which is in accordance with data taken from the literature. While three discrete temperature intervals of particular slag behaviour could be identified in sessile drop experiments, results of maximum bubble pressure trials suggest the surface tension to be lower under inert conditions compared to a reducing atmosphere. The outcomes generated in Japan additionally show a better agreement to surface tensions forecasted by model calculations. Fe{sub 2}O{sub 3} being considered to have a pronounced influence on slag characteristics is made responsible for such observations. As soon as pressure is applied, the surface tension is found to decrease significantly. In order to visualise the data obtained by means of the sessile drop technique, regression functions were employed that can be implemented into future design calculations on hot gas cleaning facilities. (orig.)

  5. Analysis of the current cost situation of wind power in Germany; Untersuchungen der aktuellen Kostensituation der Windenergienutzung in Deutschland

    Energy Technology Data Exchange (ETDEWEB)

    Rehfeldt, K. [Deutsches Windenergie-Inst. Sucursal en Espana, Pamplona (Spain); Schwenk, B. [InnoVent GmbH, Varel (Germany)

    2000-07-01

    Against the background of the discussion concerning the Reimbursement Act (StrEG) and the draft Renewable Energy Sources Act (EEG), the Bundesverband Windenergie e.V. (BWE) asked the Deutsches Windenergie-Institut (DEWI) to investigate the current cost situation of wind power in Germany. This involved a statistics of wind power generation cost over a period of 20 years. The data were obtained from wind power system operators, technical experts, producers of wind power systems and insurance companies. It was found that especially the cost of component replacement was higher than expected, so that long component life must be one of the main goals in the further development of wind power systems. According to the technical experts, component life today is much less than the rated life of 20 years. [German] Vor dem Hintergrund der Diskussion um das Stromeinspeisegesetz (StrEG) bzw. des Neuentwurfs zum Erneuerbare-Energien-Gesetz (EEG) wurde das Deutsche Windenergie-Institut (DEWI) vom Bundesverband Windenergie e.V. (BWE) beauftragt, eine Studie ueber die aktuelle Kostensituation in Deutschland zu erarbeiten. Erstmals wurden hierbei Stromerzeugungskosten aus Windenergieanlagen (WEA) ueber einen Zeitraum von 20 Jahren ermittelt. Hierbei wurden Umfrageergebnisse von Betreibern von WEA, technischen Sachverstaendigen sowie von Herstellern von WEA und Versicherungsgesellschaften verwendet, um belastbare Aussagen ueber Betriebskosten und notwendige Ersatzinvestitionen zu erhalten. Insbesondere die Aussagen ueber notwendige Ersatzinvestitionen durch die technischen Sachverstaendigen waren hoeher als erwartet, so dass es in Zukunft Ziel sein muss, insbesondere bei der Weiterentwicklung von WEA auf wesentlich laengere Lebensdauern der Bauteilkomponenten von WEA zu draengen. Nach Aussage der technischen Sachverstaendigen liegen bisher die Lebensdauern wesentlicher Bauteile der WEA, wie Rotor, Bremssystem, Pitchregelung usw., weit unter der kalkulierten Lebensdauer von 20 Jahren. (orig.)

  6. Investigations on the braking safety of utility vehicles with retarders; Untersuchungen zur Bremssicherheit von Nutzfahrzeugen mit Retardern

    Energy Technology Data Exchange (ETDEWEB)

    Pittius, R.

    1996-12-31

    When the use of retarders in utility vehicles increased in the middle of the 80s, the Forschungsvereinigung Automobiltechnik (FAT) commissioned a study on the safety aspect of this braking technology in trucks. Retarders are wear-free permanent brakes that are fitted in the drive transmission system of utility vehicles, thereby generating braking forces only at the wheels of the live shaft. The question of the possible overbraking of the live shafts was just as well investigated as the interaction between the retarder and service brake in so-called integrated braking systems, and both under conditions of low adhesion as well as in the border area of the dynamics of vehicle movement. This subject met with considerable joint interest on the part of the motor vehicle industry as well as of manufacturers of towed vehicles and unit sets. FAT, therefore, commissioned the Institut fuer Kraftfahrwesen of the University of Hannover to carry out a three-phase research project on the braking behaviour and dynamics of vehicle movement of two-axle, single vehicles as well as of two- and three-part trailer trains equipped with retarders. (orig.) [Deutsch] Als Mitte der 80er Jahre der Einsatz von Retardern in Nutzfahrzeugen zunahm, hat die Forschungsvereinigung Automobiltechnik e.V. (FAT) den Sicherheitsaspekt dieser Bremstechnik im Lastzug untersuchen lassen. Retarder sind verschleissfreie Dauerbremsen, die im Triebstrang von Nutzfahrzeugen eingebaut werden und somit Bremskraefte nur an den Raedern der Antriebsachsen erzeugen. Die Frage einer moeglichen Ueberbremsung der Antriebsachsen sollte ebenso untersucht werden wie die Wechselwirkungen zwischen Retarder und Betriebsbremsanlage in sogenannten integrierten Bremssystemen, und zwar sowohl bei niedrigen Kraftschlussbdingungen als auch im fahrdynamischen Grenzbereich. An dieser Thematik bestand ein erhebliches gemeinsames Interesse der Motorwagenindustrie sowie der Anhaenger- und Aggregathersteller. Die FAT hat deshalb das Institut fuer Kraftfahrwesen der Universitaet Hannover beauftragt, in einem dreiphasigen Forschungsvorhaben das Bremsverhalten und die Fahrdynamik vom zweiachsigen Solar-Fahrzeug und dann die von zwei- und dreigliedrigen Lastzuegen zu untersuchen, die mit Retardern ausgeruestet sind. (orig.)

  7. structure-chemical analyses of half-antiperovskites and superconductivity of parkerites; Strukturchemische Untersuchungen an Halbantiperowskiten und Supraleitung der Parkerite

    Energy Technology Data Exchange (ETDEWEB)

    Peter, Philipp

    2015-04-22

    The aim of this work was the structural investigation on Halfantiperowskites. In the process four new compounds were synthesized and a new ordering variant was found. Furthermore superconductivity was measured on selected compounds of the Parkerite-type of structure and an attempt was made to change the transition temperature by selective doping.

  8. Semantische Analyse unstrukturierter Daten. Review und Analyse: Big-Data Ansatz bei internen Untersuchungen anhand eines Beispiels

    Directory of Open Access Journals (Sweden)

    Jörg Fuchslueger

    2016-05-01

    Full Text Available In der juristischen Fallbearbeitung steht man immer häufiger vor der Herausforderung, unüberschaubare Massen an Unterlagen berücksichtigen zu müssen. Relevante Information ist verborgen in hunderttausenden E-Mails, Office Dokumenten und PDF-Dateien. All diese Unterlagen zu lesen, zu verstehen und zu beurteilen, ist in der Praxis nicht mehr möglich. Der vorliegende Artikel zeigt ein Vorgehensmodell, wie mit semantischer Inhaltsanalyse die notwendige Informationsgewinnung in umfangreichen, elektronisch gespeicherten Textbeständen durchgeführt werden kann.

  9. Investigations on generation and use of a sludge-lime fertilizer. Untersuchungen zur Erzeugung und Anwendung eines Klaerschlamm-Kalkduengers

    Energy Technology Data Exchange (ETDEWEB)

    Boehnke, B; Weiling, R

    1980-06-01

    Sludge is an important energy and raw material source, which if possible should be utilized in agriculture. Through the addition of unslaked lime a hygienically safe product can be prepared with the help of a suitable treatment process and can be offered in granulated form as a valuable sludge-lime fertilizer. Sludges of different consistencies and origins were investigated. Varying amounts and types of lime were used and the products were tested for easy handling, storage capability and temperature influence on the hygienic conditions. In order to obtain a disseminable substance, a solid matter content of over 60% is necessary. This is achieved through variation of the lime content depending on the solid content of the respective sludge. According to the existing regulations, which fix the minimum CaO content in a lime fertilizer at 30%, a predewatering of the sludge up to 25%-30% of the solid matter content is sufficient. Economic viability is assured, specially in areas where intensive agricultural use of lime fertilizer is necessary. (orig.) With 32 refs., 15 tabs., 27 figs.

  10. Experimental investigations on the mechanisms of the warm prestress effect; Experimentelle Untersuchungen zu den Mechanismen des WPS-Effekts

    Energy Technology Data Exchange (ETDEWEB)

    Roos, E.; Alsmann, U. [Stuttgart Univ. (Germany). Staatliche Materialpruefungsanstalt

    1998-11-01

    The Government-supported, joint project by IWW Freiburg, BAM Berlin, IWW Magdeburg, and MPA Stuttgart is intended to yield insight into the mechanisms underlying the WPS, warm prestress effect, and to derive on this basis a quantitative description of the WPS effect. (orig./CB) [Deutsch] Ziel eines durch das BMBF gefoerderten Gemeinschaftsprojekts von IWW Freiburg, BAM Berlin, IWW Magdeburg und MPA Stuttgart ist es, die Mechanismen des WPS-(warm prestress)-Effekts zu erklaeren und auf dieser Basis eine quantitative Beschreibung des WPS-Effekts zu ermoeglichen. (orig./MM)

  11. Investigation on the applicability of dust protection helmets in the mining industry. Untersuchungen ueber die Einsatzmoeglichkeiten von Staubschutzhelmen im Bergbau

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, H.D.; Werner, W.; Fuerst, E.

    1984-10-01

    In case of static ambient air, leakages for volumes of 25 x 1,5 l/min and air supplies >= 120 l/min or 25 x 2,0 l/min and >= 160 l/min do not occur. The increasing flow rate of moving ambient air leads to an increase of leakages. They show their largest extensions in case of lateral flow. In addition, they expand together with increasing physiological load. Therefore, the inherent air supply should not be below 160 l/min. The comparison of the dust protection helmet 'Airstream AH 1' with two respirators revealed the lowest additional physiological load for the dust protection helmet. Applicability tests in situ resulted in the following principal objections: contamination and scratches on the visor leading to visibility restriction of the wearer, bad fit, weight distribution and helmet dimensions, pressure sores and chafes of sealing parts and edges, lamp installation. Air supply and movement were felt as too high in case of low ambient temperatures, and in case of high temperatures and physiological strain it was considered as too low. There were only few objections against fan noise, weight and impediment by cable and battery. Based on the results, a specification including monitoring and maintenance of the helmet was made and additional tests for DIN design 58 645, item 7, were induced. Furthermore, a proposal regarding helmet optimisation was made.

  12. Sensitivity of MRI in detecting alveolar infiltrates. Experimental studies; Sensitivitaet der MRT fuer alveolaere Infiltrate. Experimentelle Untersuchungen

    Energy Technology Data Exchange (ETDEWEB)

    Biederer, J.; Busse, I.; Grimm, J.; Reuter, M.; Heller, M. [Kiel Univ. (Germany). Klinikum fuer Diagnostische Radiologie; Muhle, C. [Kiel Univ. (Germany). Klinik fuer Nuklearmedizin; Freitag, S. [Kiel Univ. (Germany). Inst. fuer Medizinische Informatik und Statistik

    2002-08-01

    Purpose: An experimental study using porcine lung explants and a dedicated chest phantom to evaluate the signal intensity of artificial alveolar infiltrates with T{sub 1}- and T{sub 2}-weighted MRI sequences. Material and Methods: 10 porcine lung explants were intubated, transferred into the cavity of a MRI-compatible chest phantom and inflated by continuous evacuation of the artificial pleural space. All lungs were examined with MRI at 1.5 T before and after intra-tracheal instillation of either 100 or 200 ml gelatine-stabilised liquid to simulate alveolar infiltrates. MR-examination comprised gradient echo (2D- and 3D-GRE) and fast spin echo sequences (T{sub 2}-TSE and T{sub 2}-HASTE). The signal intensity of lung parenchyma was evaluated at representative cross sections using a standardised scheme. Control studies were acquired with helical CT. Results: The instilled liquid caused patchy confluent alveolar infiltrates resembling the findings in patients with pneumonia or ARDS. CT revealed typical ground-glass opacities. Before the application of the liquid, only T{sub 2}-HASTE and T{sub 2}-TSE displayed lung parenchyma signals with a signal/noise ratio of 3.62 and 1.39, respectively. After application of the liquid, both T{sub 2}-weighted sequences showed clearly visible infiltrates with an increase in signal intensity of approx. 30% at 100 ml (p<0.01) and 60% at 200 ml (p<0.01). With 2D- and 3D-GRE the infiltrates were not visible, although the lung parenchyma signal increase was statistically significant. On 2D-GRE the increase in signal intensity reached 0.74% (p=0.32) after 100 ml and 5.6% (p<0.01) after 200 ml for 3D-GRE: 2.2% [p=0.02] at 100 ml and 4.4% at 200 ml [p<0.001]. The CT controls revealed a significant increase of lung density of 17. H.E. at 100 ml (p=0.02) and 75 H.E. at 200 ml (p<0.01). Conclusions: MRI with T{sub 2}-weighted sequences detects artificial alveolar infiltrates with high signal intensity and may be a highly sensitive tool to detect pneumonia in patients. (orig.) [German] Zielsetzung: Eine experimentelle Studie zur Untersuchung des Signalverhaltens artifizieller alveolaerer Infiltrate mit T{sub 1}- und T{sub 2}-gewichteten MR-Sequenzen. Material und Methoden: 10 Lungen-Explantate von Schweinen wurden tracheal intubiert, in der kuenstlichen Thoraxhoehle eines Phantoms durch Unterdruck entfaltet und an einem klinischen Magnetresonanztomographen bei 1,5 T untersucht. Mit gezielter Instillation von 100-200 ml Gelatineloesung wurden alveolaere Infiltrate erzeugt und mit Gradientenecho- (2D-, 3D-GRE) und schnellen Spinechosequenzen (T{sub 2}-TSE, T{sub 2}-HASTE) dargestellt. Die Signalintensitaet des Lungenparenchyms nativ und mit Infiltrat wurde an repraesentativen Querschnitten erfasst. Zum Vergleich erfolgten Kontrollen mit Spiral-CT. Ergebnisse: Die instillierte Fluessigkeit simulierte alveolaere Infiltrate mit typischem Milchglasmuster im CT, wie es an Patienten mit Pneumonie oder ARDS beobachtet wird. Vor dem Versuch zeigten nur T{sub 2}-HASTE und T{sub 2}-TSE ein Lungenparenchymsignal (Signal/Rausch-Verhaeltnis von 3,62 bzw. 1,39). Nach Instillation von Fluessigkeit fand sich in diesen Sequenzen ein Signalanstieg von ca. 30% bei 100 ml (p<0,01) bzw. 60% bei 200 ml (p<0,01). Bei 2D-GRE betrug die Signalintensitaetszunahme 0,74% (p=0,32) nach 100 ml und 5,6% (p<0,01) nach 200 ml (fuer 3D-GRE 2,2% [p=0,02] bzw. 4,4% [p<0,01]). Die CT-Kontrollen zeigten fuer 100 ml eine Dichtezunahme um durchschnittlich 17 H.E. (p=0,02) und fuer 200 ml um 75 H.E. (p<0,01). Schlussfolgerungen: Mit T{sub 2}-gewichteten Sequenzen ist die MRT zur Darstellung artifizieller alveolaerer Infiltrate geeignet. (orig.)

  13. Self-ignition of coal during in-situ gasification. Thermoanalytical investigations. Selbstentzuendung von Kohlen bei der Untertagevergasung. Thermoanalytische Untersuchungen

    Energy Technology Data Exchange (ETDEWEB)

    Choi, J O

    1986-01-10

    The underground gasification of deep coal strata via boreholes presupposes flow ways for the gasifying agent and the gasified media with a sufficiently high degree of permeability. Canal burning during countercurrent flow in low depths has been tested as a technical method for linking boreholes and enhancing gas permeability. For the execution of in situ gasification the control or prevention of the spontaneous ignition of the coal under high pressure should not be ignored, because of self-ignition resulting from canal burning in the linking phase. To investigate enthalpy change during the oxidation of coal under various conditions, a device for differential thermal analysis (DTA) was developed and constructed with which temperature development as a result of oxidation in a flowing pressure-gas atmosphere could be observed. A caloric calibration of the device permitted a direct inference of enthalpic difference from differential thermal potential as a measured value. With a regression model for reaction kinetics, the intensity of heat development was linked with kinetic data; this permitted a description of the dependence of the oxidation process on temperature and material concentration. From the interconnections discovered between the carbonization degree and enthalpy change during oxidation we may conclude that the oxidation process is controlled by the emergence of thermal decomposition products. The heat tonality diagram of the DTA of coal oxidation can be divided into three phases and interpreted in connection with the different degrees of carbonization. The results of the investigation reveal that inactivation of the coal before the actual process of linking is of considerable importance. (MOS).

  14. Studies on allergic reactions after exposure to platinum compounds; Untersuchungen ueber allergische Reaktionen bei Exposition gegen Platinverbindungen (VPT 07A)

    Energy Technology Data Exchange (ETDEWEB)

    Merget, R; Schultze-Werninghaus, G [Berufsgenossenschaftliche Kliniken, Bergmannsheil - Universitaetsklinik, Medizinische Klinik und Poliklinik, Abt. fuer Pneumologie, Allergologie und Schlafmedizin, Bochum (Germany)

    1998-12-31

    The aim of the present study was to assess the allergic hazard potential of Pt-containing substances emitted from automotive catalytic converters for the population. This was done by determining exposure-effect relationships in subjects occupationally exposed to platinum compounds in a catalytic converter manufacturing company. The company had been deemed suitable because it could be assumed that the extensive technical industrial safety measures implemented there would make for a considerably reduced exposure to platinum compounds compared to, for example, a platinum separating plant. Exposure-effect relationships were determined on the basis of platinum measurements in a catalytic-converter-manufacturing plant and of a record of new sickness cases. [Deutsch] Ziel der Untersuchung war eine Risikoabschaetzung des Allergie-Gefaehrdungspotentials Pt-haltiger Automobilkatalysatoremittate fuer die Bevoelkerung durch Ermittlung der Expositions-Wirkungsbeziehung bei beruflich gegenueber Platinverbindungen Exponierten in einem Katalysatorfertigungsbertrieb. Der gewaehlte Katalysatorbetrieb war deshalb als geeignet betrachtet worden, weil durch weitgehende technische Arbeitsschutzmassnahmen eine wesentlich geringere Exposition gegenueber Platinverbindungen anzunehmen war als zum Beispiel in Platinscheidereien. Die Expositions-Wirkungsbeziehung sollte durch Platinmessungen in einem Katalysator-Betrieb und Erfassung der Haeufigkeit von Neuerkrankungen im Laengsschnitt definiert werden. (orig.)

  15. Investigation of the amount, distribution, and contents of atmospheric precipitations. Untersuchungen ueber Menge, Verteilung und Inhaltsstoffe der Niederschlaege

    Energy Technology Data Exchange (ETDEWEB)

    Kolbe, W

    1986-01-01

    The amount, distribution, and analysis of atmospheric precipitations collected in the experimental area at 205 m above sea level is reported. The analytical data show sulfate, nitrate, phosphate, chloride, and ammonium ions, and the metals Fe, Mn, Pb, Cd, Hg, As. The pH-values are also given. After the Chernobyl reactor accident, the analyses included radioactivity measurements. The contribution also presents data collected during the last 35 years, that reveal the connection between hail storms and the fruit crop.

  16. Studies on oxygen depletion and the toxic effect of sediments; Untersuchungen zur Sauerstoffzehrung und toxischen Wirkung von Sedimenten

    Energy Technology Data Exchange (ETDEWEB)

    Pfitzner, S.; Giest, B.; Wotzka, J. [Bundesanstalt fuer Gewaesserkunde, Berlin (Germany)

    2000-11-01

    Depending on their composition and how they were formed, water sediments contain varying amounts of oxygen-depleting substances. Their portion is particularly high in fine sediment and sediments formed in conjunction with exposure to a high level of wastewater. Particularly in current-free areas like old arms, indentations, sluices and outer ports, sediment forms with a high fine grain content and a correspondingly higher potential for depletion. If, for instance, the sediments are moved and stirred up during dredging, this may impair their oxygen content since oxygen consumption is far higher in a suspended sediment than when it is undisturbed on the water bottom. The very rapid spontaneous chemical oxidation and biological oxidation of reduced substances are possible oxygen-consuming processes. (orig.) [German] Gewaessersedimente enthalten in Abhaengigkeit von ihrer Zusammensetzung und der Art ihrer Entstehung unterschiedliche Mengen an Sauerstoff zehrenden Substanzen. Ihr Anteil ist besonders hoch in Feinsedimenten und solchen, die sich unter starkem Abwassereinfluss bilden konnten. Insbesondere in stroemungsberuhigten Gebieten, wie Altarmen, Ausbuchtungen sowie Schleusen und deren Vorhaefen, reichern sich Sedimente mit hohem Feinkornanteil und dementsprechend hoher potenzieller Zehrungsfaehigkeit an. Werden die Sedimente beispielsweise durch Baggermassnahmen bewegt und aufgewirbelt, kann es zur Beeintraechtigung des Sauerstoffhaushaltes kommen, da der Sauerstoffverbrauch eines Sedimentes bei Suspension um ein Vielfaches hoeher als bei ungestoerter Lagerung am Gewaesserboden sein kann. Als Sauerstoff verbrauchende Prozesse kommen die sehr schnell verlaufende spontane chemische Oxidation sowie die biologische Oxidation reduzierter Substanzen in Betracht. (orig.)

  17. Experimental studies on the thermal properties of fast pulsed superconducting accelerator magnets; Experimentelle Untersuchungen thermischer Eigenschaften schnell gepulster supraleitender Beschleunigermagnete

    Energy Technology Data Exchange (ETDEWEB)

    Bleile, Alexander

    2016-01-06

    The new Facility for Antiproton and Ion Research FAIR is being constructed at the GSI research center in Darmstadt (Germany). This wordwide unique accelerator facility will provide beams of ions and antiprotons at high intensities and high energies for the fundamental research in nuclear, atomic and plasma physics as well as for applied science. The superconducting synchrotron SIS100 with a magnetic rigidity of 100 T/m, the core component of the FAIR facility will provide primary ion beams of all types from hydrogen up to uranium. One of the key technical systems of a new synchrotron are fast ramped electromagnets for the generation of fast ramped magnetic fields for deflecting and focusing of the ion beams. To reduce the energy consumption and to keep the operating costs of the synchrotron as low as possible superconducting magnet technology is applied in the SIS100. Superconducting magnets have been developed at GSI within the scope of the FAIR project. Although the superconducting magnet technology promises high cost saving, the power consumption of the fast ramped superconducting magnets can't be completely neglected. The pulsed operation generates dynamic losses in the iron yokes as well as in the superconducting coils of the magnets. A forced two-phase helium flow provides effective cooling for supercounducting magnets exposed to a continous relative high heat flow. The subject of this PhD thesis is experimental investigations and analysis of the dynamic power losses in fast ramped superconducting magnets and their dependencies on the operation cycles of the synchrotron. This research was conducted on the the first series SIS100 dipole magnet. Based on the experimentally defined dynamic heat loads and helium mass flow rates in the dipole magnet the heat loads and helium consumption for all other types of superconducting magnet modules of the SIS100 have been estimated. These results are essential for the development of the cooling system for the the superconducting magnets in the SIS100 accelerator ring and for the stable operation of the synchrotron.

  18. Investigations dealing with variable-speed drives of belt conveyor systems; Untersuchungen an drehzahlstellbaren Antrieben von Gurtbandfoerderanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Heuvel, B. van den [RWE Power AG, Technikzentrum Tagebaue/Hauptwerkstatt, Versuchsabteilung, Frechen (Germany)

    2006-04-15

    Safe and faultless operation of belt conveyor systems is a crucial factor in maintaining the availability of interlinked conveying systems employed in mining operations; the use of components with a high efficiency or low energy consumption and energy-conserving plant operation modes allow economic efficiency to be enhanced. With the power increase of single drives to 2500 kW the static design is gaining significance and - with the introduction of variable-speed conveyor drives - particular importance is also to be attached to the proper dynamic design and adjustment of the drive units. Comprehensive measurement and computational studies made of different conveyor drive units in the 900 to 2500 kW power range revealed that excitations of torsional natural frequencies caused by the drives' tooth contact frequencies were the reason for the damage that had occurred; remedial measures were developed the efficacy of which was demonstrated in practice. Moreover, investigations aimed at precautionary damage prevention are described which were performed with newly designed gears prior to the conversion of proven conveyor drives to variable-speed drive units. When designing new gears in the future, we recommend to also investigate them with regard to their dynamic behaviour in the drive train during the design phase by performing appropriate torsional vibration analyses. (orig.)

  19. Rasterelektronenmikroskopische und immunhistochemische Untersuchungen am Eileiter vom Schwein während Zyklus und Trächtigkeit

    OpenAIRE

    Mayer, Judith

    2008-01-01

    In der vorliegenden Arbeit wurden zum einen mit Hilfe des Rasterelektronenmikroskops die morphologischen Veränderungen des Eileiterepithels und zum anderen die Expression hypophysärer wachstums- und proliferationsfördernder Hormone und ihrer Rezeptoren immunhistochemisch und mit der Reverse Transkriptase (RT)-PCR sowohl im Verlauf des Zyklus als auch der Trächtigkeit analysiert. Hierfür wurden, von 24 Schweinen der Deutschen Landrasse, die drei Abschnitte des Eileiters (Infundibulum, Ampulle,...

  20. Conference Report: Rechtsextremismusforschung – aktuelle Tendenzen empirischer Untersuchungen [Research on Right-wing Extremism—Latest Trends in Empirical Studies

    Directory of Open Access Journals (Sweden)

    Janina Söhn

    2004-01-01

    Full Text Available During this workshop scholars presented new, mainly empirical studies which explored different aspects of right-wing extremism in Germany. While a number of talks focused on political strategies and modern forms of organization of local neo-Nazi scenes, political elites and the music industry, others had chosen a biographical view on the personal development of young right-wing extremists. Studies on the local context of and conditions for right-wing extremist actions were complemented by representative survey data on political attitudes of German citizens. Apart from discussions about the phenomenon of right-wing extremism itself, participants had the opportunity to exchange their experience of doing empirical qualitative research in a dangerous field. URN: urn:nbn:de:0114-fqs0401215

  1. Investigations on ion-beam induced desorption from cryogenic surfaces; Untersuchungen zu ionenstrahlinduzierter Desorption von kryogenen Oberflaechen

    Energy Technology Data Exchange (ETDEWEB)

    Maurer, Christoph

    2017-07-03

    A central component of FAIR, the Facility for Antiproton and Ion Research, will be the superconducting heavy ion synchrotron SIS100, which is supposed to provide reliable, high intensity beams for various applications. Its beam intensity is governed by the space charge limit, while the maximum energy is determined by the machine's magnetic rigidity. That means, ions with higher charge state can be accelerated to a higher energy, but with less intensity. For highest intensity beams, intermediate charge states have to be used instead of high charge state ions. This alleviates the issue of space charge but gives rise to dynamic vacuum effects, which also limit beam intensity: beam particles collide with residual gas particles, which leads to charge exchange and their subsequent loss. Impacting on the chamber wall, these ions release adsorbed gas particles. This process is called desorption and leads to a localized increase in pressure, which in turn causes more charge exchange. After a few rounds of self amplification, this can lead to total beam loss. This ''runaway-desorption'' is typically the main beam intensity limiting process for intermediate charge state (heavy) ion beams. The extent of this phenomenon is governed by two factors: the initial beam intensity and the desorption yield. The latter is examined within the scope of this thesis. Special emphasis is placed on the influence of the target's temperature, since the SIS100 will be a superconducting machine with cryogenic vacuum chamber walls. In order to investigate this topic, an experimental setup has been devised, built at the SIS18 and taken into commission. Based on the experience gained during operation, it has been continuously improved and extended. Another central innovation presented in this thesis is the use of gas dynamics simulations for an improved method of data analysis. Using this technique, environmental conditions like the chamber geometry and the connected pumps can be taken into account. This method can be extended to any desorption experiment employing the single shot method for measurement. Of special interest for the operation of the SIS100 at high intensities is the minimization of desorption from cryogenic surfaces. A previous examination of this topic found a breakdown of the familiar scaling of the desorption yield with the beam's energy loss for cryogenic targets. Further examination of this effect with the techniques described above is another goal of this thesis. Simultaneously, desorption measurements at room temperature for several other targets have been conducted. An unexpected result of these experiments is the influence of target surface properties, which was found to be very weak in comparison to previous results. The methods developed during this thesis, along with the results gained by their application, represent another step towards the comprehension of (heavy) ion beam induced desorption.

  2. Untersuchungen zur Anwendbarkeit eines integrierten Nachweissystems für Penicillin-Rückstände in Kuhmilch und Ziegenmilch

    OpenAIRE

    Kress, Claudia

    2010-01-01

    In der vorliegenden Arbeit wurde die Anwendbarkeit eines integrierten Nachweissystems für Penicillin-Rückstände in Kuhmilch und Ziegenmilch überprüft. Der zweite Schwerpunkt dieser Arbeit lag auf der Hemmstoffbelastung von Ziegenmilch, d.h. es sollte ein Überblick über die Belastung der in Hessen produzierten Ziegenmilch mit Penicillin-Rückständen gewonnen werden. Die „Kernmethode“ des integrierten Nachweissystems für Penicillin-Rückstände in Kuhmilch und Ziegenmilch ist ein...

  3. Investigations on uncertainties in patient positioning for prostate treatment with EPID; Untersuchungen zur Positionierungsgenauigkeit bei Prostatakonformationsbestrahlungen mittels Portal-Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Bakai, A.; Nuesslin, F. [Universitaetsklinik fuer Radioonkologie, Tuebingen (Germany). Abt. Medizinische Physik; Paulsen, F.; Plasswilm, L.; Bamberg, M. [Universitaetsklinik fuer Radioonkologie, Tuebingen (Germany). Abt. Strahlentherapie

    2002-02-01

    Background: Conformal radiotherapy techniques as used in prostate treatment allow to spare normal tissue by conforming the radiation fields to the shape of the planning target volume (PTV). To be able to fully utilize the advantages of these techniques correct patient positioning is an important prerequisite. This study employing an electronic portal imaging device (EPID) investigated the positioning uncertainties that occur in the pelvic region for different patient positioning devices. Patients and Methods: 15 patients with prostate cancer were irradiated with or without rectal balloon/pelvic mask at a linear accelerator with multileaf collimator (MLC). For each patient multiple portal images were taken from different directions and compared to the digitally reconstructed radiographs (DRRs) of the treatment planning system and to simulation films (Table 1, Figure 1). Results: In spite of different positioning devices, all patients showed comparable total positioning uncertainties of 4.0 mm (lateral), 4.5 mm (cranio-caudal) and 1.7 mm (dorso-ventral). The lateral positioning error was reduced for the pelvic mask patients while the cranio-caudal error increased (Table 2, Figure 2). A systematic and a random component sum up to the total positioning error, and a good estimate of the magnitudes of the two is possible from six to eight portal images (Figure 3). Conclusions: With a small number of portal images it is possible to find out the systematic and random positioning error of a patient. Knowledge of the random error can be used to resize the treatment margin which is clinically relevant since this error differs greatly for different patients (Figure 4). Image analysis with EPID is convenient, yet has some problems. For example, one only gets indirect information on the movement of the ventral rectum wall. The successful operation of positioning devices, although, needs further improvement - especially if one focuses on IMRT. (orig.) [German] Hintergrund: Konformationstechniken, wie sie heutzutage routinemaessig fuer Patienten mit Prostatakarzinom angewandt werden erlauben, durch Adaption der Bestrahlungsfelder an das Planungszielvolumen (PTV) umliegendes Normalgewebe zu schonen. Um die Vorteile dieser Techniken jedoch vollstaendig nutzen zu koennen, ist die korrekte Patientenpositionierung eine wichtige Voraussetzung. In dieser Studie wurde mittels Portal-Imaging (EPID) untersucht, welche Positionierungsgenauigkeiten im Beckenbereich unter Verwendung unterschiedlicher Lagerungshilfen moeglich sind. Patienten und Methode: Fuer die Studie wurden 15 Patienten mit Prostatakarzinom ausgewaehlt, die teils mit, teils ohne Rektumballon bzw. Beckenmaske an einem Linearbeschleuniger mit Viellamellenblenden (MLC) bestrahlt wurden. Von jedem Patienten wurden mehrfach aus orthogonalen Richtungen mittels eines Portal-Imaging-Systems Aufnahmen angefertigt und anschliessend mit den Planungs-DRRs (digitally reconstructed radiographs) sowie den Simulationsaufnahmen verglichen. Ergebnisse: Trotz unterschiedlicher Lagerungshilfen konnten fuer saemtliche Patientengruppen Gesamtpositionierungsungenauigkeiten von durchschnittlich 4,0 mm (lateral), 4,5 mm (kraniokaudal) sowie 1,7 mm (dorsoventral) festgestellt werden. Mit Beckenmaske war der laterale Positionierungsfehler zwar reduziert, gleichzeitig jedoch der kraniokaudale Positionierungsfehler verstaerkt. Der Gesamtpositionierungsfehler teilte sich dabei in einen systematischen und einen statistischen Anteil auf, fuer deren verlaessliche Abschaetzung sechs bis acht EPID-Aufnahmen erforderlich waren. Schlussfolgerungen: Mittels Portal-Imaging ist es moeglich, aus einer geringen Anzahl von Verifikationsaufnahmen fuer jeden Patienten den systematischen und statistischen Positionierungsfehler zu ermitteln. Der erfolgreiche Einsatz von Lagerungshilfen zur Patientenpositionierung erfordert jedoch - insbesondere im Hinblick auf IMRT - eine weitere Optimierung. (orig.)

  4. ALEXANDRU POPA,UNTERSUCHUNGEN ZU DEN RÖMISCH-BARBARISCHEN KONTAKTEN ÖSTLICH DER RÖMISCHEN PROVINZ DACIA

    Directory of Open Access Journals (Sweden)

    Vasile Iarmulschi

    2016-11-01

    Full Text Available ABHNADLUNGEN ZUR VOR-UND FRÜHGESCHICHTE, ZUR KLASSICHEN UND PROVINZIAL-RÖMISCHEN ARCHÄOLOGIE UND ZUR GESCHICHTE DES ALTERTUMS, Band 47, Bonn 2015: Dr. Rudolf Habelt,279 pgs., 130 figures, 58 plates, ISBN 978-3-7749-3884-7

  5. Numerical investigations of the electroslag remelting process for alloy 718; Numerische Untersuchungen des Elektroschlacke-Umschmelzprozesses fuer Alloy 718

    Energy Technology Data Exchange (ETDEWEB)

    Giesselmann, Nils

    2014-07-01

    In this dissertation the development of a simulation strategy is presented, which enables a detailed description of relevant regions to appropriately model the electroslag remelting process. One of the challenges is to ensure a sufficient efficiency of the numerical model so that it can be used to perform extensive parametric studies. This is achieved by combining multiple computational domains and coupling the simulation codes ANSYS FLUENT and ANSYS EMAG. Therefore the electroslag remelting process is divided into a droplet simulation and models that account for the fluid flow in the slag and fluid flow and solidification in the metal pool. The droplet simulation considers the multiphase flow and the interaction of fluid flow and magneto hydrodynamics to simulate the behavior of the metal droplets passing through the slag layer. The Lorentz force is the main driving force for the fluid flow established in the slag region, which causes the liquid metal film on the electrode's bottom surface to be transported to the centerline. Therefore it was found that no metal droplets detach near the electrode's edge. Instead they accumulate at a certain characteristic radius. Between this radius and the centerline metal droplets form and detach homogeneously. The fluid flow in the slag region is directed to the centerline near the electrode's bottom surface, points downwards on the centerline, moves outwards near the phase boundary to the metal pool and is directed upwards at the surface of the copper mold. In the case of the smaller scale IME remelting plant, metal droplets only occur on the centerline. The steady state simulation of the electroslag remelting process developed during this work introduces a static phase boundary, which separates the slag and the metal region. The formulation of the static phase boundary drastically reduced the time required until convergence is achieved. The simulation model has been extensively validated by comparing the numerical results to experimentally gathered data for both the IME laboratory scale plant and the VDM industrial scale remelting unit. The numerical model has successfully been calibrated leading to a good agreement to the experimentally gathered data for all investigated geometries and process conditions. The validation has been done considering the local solidification rate as well as the pool geometry. Parametric studies indicate that the melting rate is the most important quantity that determines the pool geometry. Two freckle criteria by Valdes and Boettger were examined. The Valdes criterion suggested that freckles may form for a variety of process conditions and might even form in the ingot center. This is contradicted by the Boettger criterion, which states that no freckles should be found in any of the examined cases. As no freckles could be found in any of the examined ingots, Boettger's criterion appears to be more reliable. This hypothesis is supported by both the more plausible freckle position and the increased risk for freckles caused by a melting rate fluctuation. The optical evaluation of the etched ingot slices is very important as it is used to reconstruct the shape of the liquidus isothermal line. For this purpose an automatic evaluation algorithm was created, that carries out this reconstruction by looking at the grain boundary orientation on slices. A camera equipped with a macro lens has been mounted on a driven traverse system that successively takes pictures of the entire slice. These pictures were then stitched together, resulting in a multi gigapixel image. It is now possible to zoom in on every position on the slice and to measure SDAS values. Therefore the SDAS can clearly be identified and each SDAS measurement is associated with the corresponding coordinates on the slice. This technique leads to an increased spatial resolution. The opinion on the correlation between SDAS and local solidification rate, however, is not unanimous in the literature sources. Interdendritic fluid flow simulations on a micro scale were performed based on the lattice Boltzmann method to determine the permeability perpendicular to the dendrites. The simulated permeability agrees very well with the calibrated permeability obtained from the remelting simulation. Besides using this permeability to validate the calibrated value, knowledge of the interdendritic permeability is required in Boettger's freckle criterion. The influence of the copper mold's base plate cooling on the process has also been investigated. It was found that its effect on the pool decreases quickly as the ingot grows. The influenced region gets even smaller as the melting rate is increased. Furthermore the electrode's energy balance has been reviewed. It was concluded analytically and numerically that for a specific alloy the ratio between melting rate and electrode diameter is crucial to predicting a possible rise of the melting rate before entering the hot topping stage.

  6. Investigations on quinquethiophenes as donor materials in organic solar cells; Untersuchungen an Quinquethiophenen zur Verwendung als Donator in Organischen Solarzellen

    Energy Technology Data Exchange (ETDEWEB)

    Schulze, Kerstin

    2008-07-01

    Organic photovoltaics could in the future represent a possibility for energy production from renewable energy sources. The advance consists here first of all in the potential of a very reasonable fabrication, for instance a production in the role-to-role procedurre, which can be prusued so on flexible substrates like for instance foils. Although the material costs are low, until the commercialization of organic solar cells among others an increasement of their power efficiency is necessary. Preferably in organic solar cells donor and acceptor materials should be applied, the absorption spectra and energy levels of which are ideally matched, because so can high zero-current voltages be reached. Additionally high absorption coefficents of the materials over a large spectral range can lead to high current densities in these photovoltaic components. In this thesis novel quinquethiophenes as donors in organic solar cells are studied, which consist as basic unit of five thiophene rings as well as dicyanovinyl end groups and alkyl side chains. The studied materials possess a high absorption coefficient and reach because of the high ionization potential high zero-current voltages in organic solar cells under application of the fullerenet C{sub 60} as acceptor. Simultaneously a efficient separation of the excitons on the acceptor-donor interface occurs. However the high ionization potential of the quinquethiophenes puts special requirements to the further solar-cell structure. Within this thesis it is shown that adifference between internal voltage and zero-current voltage influences decidingly the shape of the solar-cell characteristic and can generate a S-shape in the neighbourhood of the zero-current voltage. The internal voltage is hereby determined by the contacting of the photoactive layers. An increasement of the internal voltage of the solar cell can be reached by a corresponding material choice. So in this thesis it is shown that organic solar cells based on these quinquethiophenes without energetic barriers for free charge carriers within the component exhibit no S-shape of the characteristic. Also the influence of the different quinquethiophene derivates on the solar-cell characteristics is studied. Hereby it is shown that the length of the alkyl side chains has an influence on the hole injection as well as the hole mobility on the oligothiophene, which influences among others the shape of the current-voltage characteristic. Finally the possibility of the application of this class of materials in tandem solar cells is shown as well as the comparison of two different anode materials, both important aspects for a commercial conversion. [German] Organische Photovoltaik koennte zukuenftig eine Moeglichkeit zur Energiegewinnung aus erneuerbaren Energiequellen darstellen. Der Vorteil besteht hier vor allen Dingen in dem Potential einer sehr kostenguenstigen Herstellung, zum Beispiel einer Produktion im Rolle-zu-Rolle-Verfahren, welche so auf flexiblen Substraten wie beispielsweise Folien erfolgen kann. Obwohl die Materialkosten gering sind, ist bis zu einer Kommerzialisierung Organischer Solarzellen unter anderem eine Erhoehung ihrer Leistungseffizienz notwendig. Vorzugsweise sollten in Organischen Solarzellen Donator- und Akzeptormaterialien verwendet werden, deren Absorptionsspektren und Energieniveaus ideal aufeinander abgestimmt sind, da so zum Beispiel hohe Leerlaufspannungen erreicht werden koennen. Zusaetzlich koennen hohe Absorptionskoeffizienten der Materialien ueber einen grossen spektralen Bereich zu hohen Stromdichten in diesen photovoltaischen Bauelementen fuehren. In dieser Arbeit werden neuartige Quinquethiophene als Donatormaterial in Organischen Solarzellen untersucht, welche als Grundeinheit aus fuenf Thiophenringen sowie Dicyanovinylendgruppen und Alkylseitenketten bestehen. Die untersuchten Materialien besitzen einen hohen Absorptionskoeffizienten und erreichten auf Grund des hohen Ionisationspotentials hohe Leerlaufspannungen in Organischen Solarzellen unter Verwendung des Fullerens C{sub 60} als Akzeptor. Gleichzeitig tritt eine effiziente Trennung der Exzitonen an der Akzeptor-Donator-Grenzflaeche auf. Jedoch stellt das hohe Ionisationspotential der Quinquethiophene spezielle Anforderungen an die weitere Solarzellenstruktur. Innerhalb dieser Arbeit wird gezeigt, dass ein Unterschied von eingebauter Spannung und Leerlaufspannung die Form der Solarzellen-Kennlinie entscheidend beeinflusst und eine S-Form in der Naehe der Leerlaufspannung erzeugen kann. Die eingebaute Spannung wird hierbei durch die Kontaktierung der photoaktiven Schichten bestimmt. Eine Erhoehung der eingebauten Spannung der Solarzelle kann durch eine entsprechende Materialwahl erreicht werden. So wird in dieser Arbeit gezeigt, dass Organische Solarzellen basierend auf diesen Quinquethiophenen ohne energetische Barrieren fuer freie Ladungstraeger innerhalb des Bauelements keine S-Form der Kennlinie aufweisen. Ebenfalls wird der Einfluss der unterschiedlichen Quinquethiophenderivate auf die Solarzellen-Charakteristik untersucht. Hierbei wird gezeigt, dass die Laenge der Alkylseitenketten einen Einfluss auf die Loecherinjektion sowie die Loecherbeweglichkeit auf dem Oligothiophen hat, welches unter anderem auch die Form der Strom-Spannungs-Kennlinie beeinflusst. Abschliessend wird die Moeglichkeit der Verwendung dieser Materialklasse in Tandemsolarzellen gezeigt sowie der Vergleich von zwei unterschiedlichen Anodenmaterialien, beides wichtige Aspekte fuer eine kommerzielle Umsetzung. (orig.)

  7. Comparative studies in the cellular immunostimulation by whole body irradiation. Vergleichende Untersuchungen ueber die zellulaere Immunstimulation durch Ganzkoerperbestrahlung

    Energy Technology Data Exchange (ETDEWEB)

    Dietz, R.; Schwarze, G. (Service de Radiologie, Centre Hospitalier de Luxembourg (Luxembourg) Medizinische Universitaetsklinik I, Homburg/Saar (Germany))

    1992-04-01

    The effect of the cellular immune response by total body irradiation was investigated. The transplant survival (skin grafts) was determined as immune parameter. Donors were colony bred Wistar rats and recipients were colony bred Sprague Dawley rats. The investigations were carried out with irradiated rats and with rats irradiated after thymectomy and/or adrenalectomy as well as with animals without irradiation. A single total-body irradiation (1 and 2 Gy) was administered. The skin graft survival in irradiated rats was significant shorter (radiogenic immunostimulation) than in unirradiated rats; there were no significant differences between the operated (thymectomy and/or adrenalectomy) and not operated animals. Including precedent examinations this radiogenic immunostimulation is caused by relativly selective inactivation of T-suppressor cells. (orig.).

  8. Die kupferzeitliche Siedlung Pietrele an der Unteren Donau. Bericht über die Ausgrabungen und geomorphologischen Untersuchungen im Sommer 2010

    DEFF Research Database (Denmark)

    Nørgaard, Heide Wrobel

    2012-01-01

    Seit der Kampagne 2008 und dem letzten Zwischenbericht über den nichtmetallenen Schmuck wurden zahlreiche weitere Stücke dieser Kleinfundkategorie auf dem Tell und in der Außensiedlung gefunden. Auch das Formenspektrum hat sich erheblich erweitert. Der in der bisherigen Forschung als elitär anges...

  9. Idle load losses of an injection-lubricated spur gear drive; Untersuchungen zu den Leerlaufverlusten eines einspritzgeschmierten Stirnradgetriebes

    Energy Technology Data Exchange (ETDEWEB)

    Dick, A.K.

    2000-07-01

    The author investigated the effects of pressure in the gear casing on the load-independent meshing losses up to circumferential speeds of v{sub t} = 200 m/s. Apart from the reduction of losses, the limits of pressure drop are of interest. As the oil retains its characteristics even in partial vacuum, neither oil components nor additives must evaporate during operation. This means that also the effects of partial vacuum on the physical mechanisms was investigated as these may induce explosions of the oil spray inside the gear. Also considered are the characteristics of oil and air which are required for the design of the suction system. The investigations were carried out in close cooperation with Messrs. BHS-Cincinnati, Sonthofen, with financial aid from the Arbeitsgemeinschaft Industrieller Forschungsvereinigungen (AIF). [German] Turbogetriebe werden vorzugsweise zur Drehzahlwandlung zwischen Turbinen und Generatoren oder Verdichtern eingesetzt. Die groessten bekannten Ausfuehrungen solcher Getriebe liegen derzeit bei Leistungen bis P{sub A}=100 MW mit Antriebsdrehzahlen bis n{sub T}=7200 min{sup -1}. Mit der stetigen Weiterentwicklung der Antriebsmaschinen wachsen auch die Anforderungen an die Turbogetriebe. Derzeit befinden sich Anlagen mit P{sub A}=140 MW und Getriebeeingangsdrehzahlen bis n{sub 1}=10 000 min{sup -1} im Planungsstadium. Mit der Umfangsgeschwindigkeit steigen die Ventilations- und Quetschverluste ueberproportional an. Die daraus resultierende groessere Verlustwaerme fuehrt dazu, dass die Probleme bezueglich Kuehlung und Schmierung fuer den Getriebebauer zunehmend in den Vordergrund treten. Im Betrieb reicht der zur Schmierung benoetigte Oelvolumenstrom nicht zur Kuehlung der Getriebe aus, der groesste Teil des eingespritzten Oelvolumenstroms wird zur Kuehlung benoetigt. Dieser Volumenstrom senkt das Temperaturniveau im Getriebe, verschlechtert aber gleichzeitig den Getriebewirkungsgrad n{sub G}. Da die Getriebe zwischen Kraft- und Arbeitsmaschine in Reihe geschaltet sind, wirkt sich dies direkt auf den Wirkungsgrad der Anlage aus. Mit dem im Rahmen dieser Arbeit gebauten Pruefstand wurde die Druckabhaengigkeit der lastunabhaengigen Verzahnungsverluste eines Stirnradpaares bis zu Umfangsgeschwindigkeiten von v{sub t}=200 m/s fuer Druecke von p{sub G}=0.13 bar / 1.4 bar ermittelt. Die gemessenen Ventilations- und Quetschverluste sind linear vom Druck abhaengig. Die aus bekannten Potenzansaetze zur Berechnung der lastunabhaengigen Verzahnungsverluste wurden bezueglich der Impulsverluste korrigiert. Ausserdem wurde der Faktor F{sub Druck} zur Beschreibung der Druckabhaengigkeit von Ventilations- und Quetschverlusten neu eingefuehrt. Die Stroemungsvorgaenge im Getriebegehaeuse beeinflussen die lastunabhaengigen Verluste. Durch das Teilvakuum werden die Stroemungsvorgaenge im Getriebe veraendert. Aehnliche Effekte koennen u.U. durch eine enge Kapselung der Rotoren erzielt werden. Die Versuchsergebnisse zeigen, dass das Potential fuer eine weitere Verlustreduzierung bei niedrigen Druecken gering ist. Da jedoch auch in Zukunft Turbogetriebe bei Atmosphaerendruck betrieben werden, sollte der Einfluss von eng anliegenden Getriebegehaeusen untersucht werden. (orig./AKF)

  10. Investigations to identify organic pollutions in sewer slime. Final report; Untersuchungen zur Identifizierung organischer Schadstoffe in Sielhaeuten. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Antusch, E.; Sauer, J.; Ripp, C.; Hahn, H.H.

    1997-07-31

    An analytical method to measure organic compounds in sewer slime and sewage sludge has been developed. The method needs no halogenated solvents. Furthermore, the sorption behavior of sewer slime has been investigated. Chlorophenols, as an example of more polar organic compounds, show a more stronger and faster desorption from sewer slime than for example PAH. pH-value and fat-content (resp. content of organic carbon) are the most important parameters affecting the sorption kinetic and sorption capacity of sewer slime. To get comparable results, all datas should be refered to the content of organic carbon of the sewer slime. By constructing pollutions-profiles of parameters like AOX, PCB, Flame Protection Agencies and PAH in the sewers of an industrial area, emissions could be localized. (orig.) [Deutsch] Es wurde eine analytische Methode entwickelt, die es erlaubt, ein breites Spektrum lipophiler organischer Schadstoffe in Sielhaut und Klaerschlamm zu identifizieren, als quantitativ zu bestimmen. Die Methode kommt ohne halogenierte Loesungsmittel aus. Verbindungen, die aufgrund ihrer Wasserunloeslichkeit nicht im Abwasser nachgewiesen werden konnten, koennen durch Sielhautanalyse verfolgt werden. Anhand von Schadstoffprofilen in Nebensammlern eines Industriegebietes konnte beispielhaft die Lokalisierung von punktfoermigen Schadstoffeinleitungen demonstriert werden. Erfolgreich verlief auch die Identifizierung eines AOX-Emittenten. Ebenso sind die Eintragspfade von Stoffen, die im Verdacht stehen, endokrine Wirkungen zu haben mit Sielhautanalyse aufklaerbar. Das Sorptionsverhalten der Sielhaut wird durch Faktoren, wie pH und Fettgehalt gepraegt. Bei der Auswertung der Proben muessen die Werte auf den organischen Kohlenstoffgehalt bezogen werden. (orig.)

  11. Experimental and theoretical investigations on the release and propagation of heavy gas; Experimentelle und theoretische Untersuchungen zur Schwergasfreisetzung und -ausbreitung

    Energy Technology Data Exchange (ETDEWEB)

    Rauchegger, Christian

    2013-06-01

    The hazardous potential of accidental heavy gas releases, especially those involving flammable and toxic gases, is widely known. In order to predict the area in which these gases are in hazardous concentrations, an estimation of the dispersion of these gases must be carried out. While the hazardous area for flammable heavy gases is determined by the lower explosion limit (ca. > 1 vol.%), the release of toxic heavy gases can result in a much larger hazardous area, as toxic gases, even in very low concentrations (ca. < 3000 ppm), have the potential to be highly damaging. The VDI guideline 3783, which is considered as state-of-the-art in Germany, can be used to estimate the dispersion of heavy gases. However, VDI 3783 gives no method for the prediction of the height and width of a heavy gas cloud, which are both required for quantitative risk analysis as well as for a possible coupling of a Lagrangian particle model with the VDI 3783 heavy gas dispersion model. Therefore, further calculation methods were used to describe these dimensions and were evaluated against, experimental studies of the length, width and height of the heavy and neutral gas field. The influence of the source height on the heavy gas dispersion was also investigated. It was found that elevating the source leads to a reduction of the length of the heavy gas area. Once the source reaches a critical height, a heavy gas area at ground level no longer exists. Therefore, for release heights above the critical height, heavy gas dispersion effects can be neglected and the calculation of the heavy gas area according to VDI 3783 part 2 is therefore no longer necessary. The release of heavy gases can occur from a process plant as well as from a standard gas bottle. For the release of heavy gases from standard gas bottles, a mathematical model has been developed to predict the time-dependent mass flow. This model takes into account the time-dependent temperature distribution of the bottle wall, and contains a detailed description of the energy and mass balances as well as the possible occurrence of two-phase flow. To validate the model experimental studies with various gases, gas bottle sizes and bottle types were performed. The model predictions and the experimental data show good systematic agreement.

  12. Investigations on oxy-fuel combustion in glass melting furnaces; Untersuchungen zur Oxy-Fuel-Feuerung in Glasschmelzwannen

    Energy Technology Data Exchange (ETDEWEB)

    Leicher, Joerg; Giese, Anne [Gaswaerme-Institut e.V., Essen (Germany)

    2011-12-15

    Glass melting requires process temperatures of more than 1600 C which are usually achieved using intensive air preheating and near-stoichiometric combustion. This often leads to high nitrous oxide emissions (NO{sub x}). Oxy-fuel technology offers an interesting alternative since high combustion temperatures can be achieved using pure oxygen as oxidizer while obtaining low NO{sub x} emissions. In the course of the AiF research project ''O2-Glaswanne'' (IGF-Nr.: 15987 N), Gaswaerme- Institut e.V. Essen investigates this combustion process by experimental and numerical means in order to determine potential optimization approaches for glass melting furnaces.

  13. Genamplifikation in humanen Zellen: Untersuchungen an einem Leukämiefall und an HeLa-Zellen

    OpenAIRE

    Bruckert, Petra

    2003-01-01

    Die cytogenetische Manifestation von Genamplifikation in humanen Zellen wurde in einem Fall von akuter myeloischer Leukämie (AML) sowie an der humanen Cervixcarcinomzelllinie HeLa S3 untersucht. In dem AML-Fall ergab die Karyotypisierung der Leukämiezellen neben dem Verlust eines X-Chromosoms das Vorliegen einer extrachromosomalen Genamplifikation in Form von Double Minutes. Mit Hilfe der Comparativen Genomischen Hybridisierung (CGH) und der Fluoreszenz-in situ-Hybridisierung (FISH) wurde die...

  14. Studies on the oxygen precipitation in highly boron doped silicon; Untersuchungen zur Sauerstoffausscheidung in hoch bordotiertem Silicium

    Energy Technology Data Exchange (ETDEWEB)

    Zschorsch, Markus

    2007-12-14

    The aim of this thesis was the getting of new knowledge on the elucidation of the oxygen precipitation in highly doped silicon. In the study of the early phases of the oxygen precipitation boron-oxygen complexes and their kinetics could be indirectly detected. These arise already during the cooling of the crystal and can be destroyed by subsequent temperature processes. The formation of the here as BO assumed species during the cooling after the silicon crystal fabrication could be numerically reproduced. Furthermore the study of early precipitation phases by means of neutron small angle scattering a maximum of the oxygen precipitation at {rho}=9 m{omega}cm. It could be shown that the decreasing of this at increasing boron concentration can be most probably reduced to boron precipitations. Furthermore it could be shown that after a tempering time of 24 hours at 700 C in silicon with {rho}=9 m{omega}cm platelet-shaped precipitates form. By the study of the precipitate growth could be shown that also in this phase the oxygen precipitation in silicon is strongest with a specific resistance of {rho}=9 m{omega}cm. By means of FTIR spectroscopy a new absorption band at a wave number of 1038 cm{sup -1} was found, which could be assigned to a boron species. By different experiments it is considered as probable that at this species it deals with BI respectively B{sub 2}I complexes.

  15. Erosion behaviour of ultrathin carbon layers and hydrogen retention in beryllium; Untersuchungen zur Erosion ultraduenner Kohlenstoffschichten und Wasserstoffrueckhaltung in Beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Reinelt, Matthias

    2008-04-16

    Plasma-wall-interaction plays an important role on the way to technical feasibility of thermonuclear fusion. In this context, the erosion behavior of few nanometer thin amorphous carbon layers on different metallic substrates by energetic deuterium and helium ions is investigated. Several aspects of the interaction are distinguishable by XPS. Ion induced carbide formation is governed by kinematic intermixing of carbon and metal substrate. Several methods of quantification of XPS measurements are developed and discussed. Comparison of results from these methods with NRA measurements show that surface roughness and implantation of particles into the carbon layer and intermixing zone influence the XPS measurements, which are sensitive to parameters such as material density. The retention of 1 keV deuterium ions implanted into single crystalline and cleaned beryllium at room temperature is investigated by temperature programmed desorption (TPD). The residual BeO coverage was 0.2 ML. The retention is 78% at low fluences and saturates above a bombardment with a fluence of 2.10{sup 17} cm{sup -2}. The retained maximum areal density is 2.10{sup 17} cm{sup -2}. Above 900 K, no deuterium is retained in the sample. An onset of self diffusion is observed at this temperature and metallic beryllium from the bulk segregates though thin BeO layers on the surface. From deuterium desorption traces, retention mechanisms are obtained. The measured TPDspectra are modeled by TMAP7 and rate equations to obtain activation energies for the release processes. From these, binding energies for the system Be-D are derived. Up to a implantation fluence of 1.10{sup 17} cm{sup -2}, deuterium is trapped in ion induced defects in the beryllium lattice with binding energies of 1.69 eV and 1.86 eV and release temperatures of 770 K and 840 K, respectively. The occupation of these states shows a different isotope behavior for {sup 1}H and {sup 2}H. The states are filled by diffusion of deuterium at the end of its implantation trajectory. Above a implantation fluence of 1.10{sup 17} cm{sup -2}, local supersaturation and destabilization of the beryllium lattice leads to the formation of structural modifications. Deuterium is adsorbed on the surface of nanoscaled, closes voids in these areas. Energetic considerations show, that no molecular deuterium is formed under such circumstances. The binding energies of these states are 1.06 eV and 1.14 eV with release temperatures of 440 K and 470 K respectively. Implantation at substrate temperatures above 300 K lead to the formation of increasing amounts of BeD2, which decomposes at 570 K. The influence of a thin surface oxide coverage (1-3 ML BeO) is investigated. This shows, that none of the above mentioned binding states is limited by deuterium recombination. Deuterium bound to surface oxide is released at 680 K. (orig.)

  16. MR imaging of avascular femoral head necrosis - pre- and postoperative studies. Prae- und postoperative kernspintomographische Untersuchungen bei avaskulaeren Hueftkopfnekrosen

    Energy Technology Data Exchange (ETDEWEB)

    Schedel, H; Ziegler, L; Vogl, T; Hilbertz, T; Lissner, J [Muenchen Univ. (Germany). Radiologische Klinik und Poliklinik; Buchner, H [Muenchen Univ. (Germany). Orthopaedische Klinik und Poliklinik

    1992-05-01

    46 patients with avascular necrosis of the femoral head were examined by T[sub 2]- and T[sub 1]-weighted MR before and after infusion of Gd-DTPA. Both sides were involved in 12 cases. The classification was done according to Ficat. In early stages and in postoperative studies a correlation of signal intensity after infusion of Gd-DTPA and clinical symptoms was found. Hyperintensity of the avascular area or of the implanted material was assumed to be vascularised or vital components in 4 cases of Ficat 1 and 15 postoperative studies. Contrariwise, we found in 5 patients with severe postoperative symptoms, low signal intensity areas due to avascular regions. (orig.).

  17. Tests on the stability of the displacement current in a cubic space; Untersuchungen zur Stabilitaet der Verdraengungsstroemung in einem Kubusraum

    Energy Technology Data Exchange (ETDEWEB)

    Gores, I.; Fitzner, K. [Technische Univ. Berlin (Germany). Hermann-Rietschel-Institut fuer Heizungs- und Klimatechnik

    2000-07-01

    Air current flow rates inside rooms have considerable effect on thermal comfort. Apart from the forced air currents of air conditioning systems, there are upward and downward currents near heat sources and heat sinks. If both types of air currents are superposed, the maximum air flow rate may increase, resulting in reduced thermal comfort. Greater internal loads in modern office buildings (e.g. call centres) lead one to expect increasing problems as air current flow rates get faster with increasing loads. [German] Die Luftgeschwindigkeiten in Innenraeumen haben einen wichtigen Einfluss auf die thermische Behaglichkeit. Neben den erzwungenen Luftstroemungen durch RLT-Anlagen beeinflussen insbesondere auch Auf- und Abtriebsstroemungen an Waermequellen bzw. -senken die Aufenthaltszone. Bei der Ueberlagerung der beiden Stroemungen kann es zu einer Verstaerkung der maximalen Luftgeschwindigkeit kommen, die zu Unbehaglichkeit fuehrt. Die Zunahme der inneren Lasten in heutigen Buerogebaeuden (z.B. Callcenter) laesst eine Verschaerfung des Problems erwarten, da die Luftgeschwindigkeiten mit steigender Last zunehmen. (orig.)

  18. Studies on allergic reactions after exposure to platinum compounds; Untersuchungen ueber allergische Reaktionen bei Exposition gegen Platinverbindungen (VPT 07A)

    Energy Technology Data Exchange (ETDEWEB)

    Merget, R.; Schultze-Werninghaus, G. [Berufsgenossenschaftliche Kliniken, Bergmannsheil - Universitaetsklinik, Medizinische Klinik und Poliklinik, Abt. fuer Pneumologie, Allergologie und Schlafmedizin, Bochum (Germany)

    1997-12-31

    The aim of the present study was to assess the allergic hazard potential of Pt-containing substances emitted from automotive catalytic converters for the population. This was done by determining exposure-effect relationships in subjects occupationally exposed to platinum compounds in a catalytic converter manufacturing company. The company had been deemed suitable because it could be assumed that the extensive technical industrial safety measures implemented there would make for a considerably reduced exposure to platinum compounds compared to, for example, a platinum separating plant. Exposure-effect relationships were determined on the basis of platinum measurements in a catalytic-converter-manufacturing plant and of a record of new sickness cases. [Deutsch] Ziel der Untersuchung war eine Risikoabschaetzung des Allergie-Gefaehrdungspotentials Pt-haltiger Automobilkatalysatoremittate fuer die Bevoelkerung durch Ermittlung der Expositions-Wirkungsbeziehung bei beruflich gegenueber Platinverbindungen Exponierten in einem Katalysatorfertigungsbertrieb. Der gewaehlte Katalysatorbetrieb war deshalb als geeignet betrachtet worden, weil durch weitgehende technische Arbeitsschutzmassnahmen eine wesentlich geringere Exposition gegenueber Platinverbindungen anzunehmen war als zum Beispiel in Platinscheidereien. Die Expositions-Wirkungsbeziehung sollte durch Platinmessungen in einem Katalysator-Betrieb und Erfassung der Haeufigkeit von Neuerkrankungen im Laengsschnitt definiert werden. (orig.)

  19. Spontaneous-fission decay properties and production cross-sections for the neutron-deficient nobelium isotopes formed in the sup 4 sup 4 sup , sup 4 sup 8 Ca+ sup 2 sup 0 sup 4 sup , sup 2 sup 0 sup 6 sup , sup 2 sup 0 sup 8 Pb reactions

    CERN Document Server

    Belozerov, A V; Chepigin, V I; Drobina, T P; Gorshkov, V A; Kabachenko, A P; Malyshev, O N; Merkin, I M; Oganessian, Yu T; Popeko, A G; Sagaidak, R N; Svirikhin, A I; Yeremin, A V; Berek, G; Brida, I; Sáro, S

    2003-01-01

    Heavy-ion fusion reactions sup 4 sup 8 Ca+ sup 2 sup 0 sup 4 Pb and sup 4 sup 4 Ca+ sup 2 sup 0 sup 8 Pb leading to the same compound nucleus sup 2 sup 5 sup 2 No sup * were run in attempts to produce new neutron-deficient spontaneous-fission isotopes of sup 2 sup 4 sup 9 sup , sup 2 sup 5 sup 0 No using the electrostatic separator VASSILISSA. Production cross-sections for the spontaneous-fission activities with the half-lives 5.6 and 54 mu s observed in these reactions are compared with the measured ones for the well-known isotopes of sup 2 sup 5 sup 1 sup - sup 2 sup 5 sup 5 No formed in the heavy-ion fusion reactions sup 4 sup 8 Ca+ sup 2 sup 0 sup 6 Pb and sup 4 sup 8 Ca+ sup 2 sup 0 sup 8 Pb. The obtained excitation functions for the reaction products formed after the evaporation of 1-4 neutrons from the corresponding compound No nuclei have been compared with similar data obtained earlier and results of statistical model calculations. (orig.)

  20. Cross Selling Management

    OpenAIRE

    Nufer, Gerd; Kelm, Daniel

    2011-01-01

    Erfolgreiches Cross Selling Management bietet die Möglichkeit, die Profitabilität von Neu- oder Bestandskunden zu steigern und kann zur Verbesserung der Kundenzufriedenheit, Kundenbindung und Verlängerung des Kundenlebenszyklus beitragen. Um erfolgreiches Cross Selling Management zu betreiben, sind ein systematisches Vorgehen und die Bereitstellung von Unternehmensressourcen notwendig. Umfangreiche vorbereitende Maßnahmen stellen sicher, dass Cross Selling nicht dem Zufall überlassen wird. De...

  1. Investigations of the pre-treatment and the conversion of energy crops into biogas and bioethanol; Untersuchungen zur Aufbereitung und Umwandlung von Energiepflanzen in Biogas und Bioethanol

    Energy Technology Data Exchange (ETDEWEB)

    Schumacher, Britt

    2008-07-01

    Due to finite fossil resources, one opportunity for the future is to increase the supply of energy out of renewable energy sources. One of many opportunities is the use of biomass, which offers plenty combinations of different kinds of biomass, paths of utilization and conversion techniques for a flexible adaptation to natural local and regional frameworks as well as the anthropogenic needs. For an efficient utilization of the limited arable land for the supply of bioenergy, there is a need of up-to-date and proof data about specific energy yields and yields per hectare. The aim of this investigation was to determine these data for the biogas and bioethanol sectors. Batch-tests were carried out in laboratory scaled digesters to investigate specific biogas and bioethanol yields. Additionally the testing of different techniques of pre-treatment for energy crops and their effects on the biogas yield and the progression of the formation of methane were focused. The conversion of maize silage and full ripe triticale into biogas and bioethanol was compared by an energy and environmental balance. The steam explosion technique was included. Pre-treatment The steam explosion pre-treatment of biomass increases the speed of formation of methane and partly increases the methane yields. The effects differ depending on the kind of biomass and the stage of ripening. Other techniques of pre-treatment like microwaving and cooking did not show significant or partly negative effects. A variation of parameters in the trial setup might be interesting. Besides the positive effects of the steam explosion technique there are some arguments like the additional costs of investment, the diminished concentration of nutrients respectively the increase of material flow against it. The additional energy consumption, mostly thermal energy, can be supplied from waste heat out of the combined heat and power plant (CHP). The screening and the production of technical enzymes for the efficient pre-degradation of raw materials containing high amounts of lignocellulose should be the subject of research and development in the future. The combination of biological (enzymatic), chemical, thermal and mechanical pre-treatment techniques need to be investigated with the focus on energy efficiency. Methane yields of energy crops and stillage A broad number of biogas tests had been carried out on various maize cultivars. The specific methane yields of the maize cultivars varied over the harvesting date differently. The cultivars with a low ripening number reached higher specific methane yields. The dominant factor for the energy yield per hectare was the dry matter yield, not the specific methane yield. In general it is recommended to use well adapted cultivars with high dry matter yields and a good ensilaging behaviour. The catch crops increased the methane yields per hectare just partly. But for reasons of soil conservation the cultivation is recommended. The nitrogen fertilizer had mostly a positive effect on the dry matter yields and the energy yields per hectare, respectively. Maize gained higher energy yields per hectare than switch grass. The utilization of stillage out of whole maize plants or triticale's grain from the ethanol production as well as the utilization of by-products like straw in the biogas production could double the energy output per hectare compared to the simple ethanol production. Further options for the optimization of the biogas production under conditions of practice are digester systems well-adapted on the substrate, the use of multi step systems and the development of analytic methods in order to gain effective process control. Correlation between chemical components and measured methane yields The specific methane yields calculated out of the neutral detergents fibre, starch, sugar, raw proteins and its substrate-specific factors were very close to the experimentally determined yields of the maize cultivars for the four harvesting times. But the measured and calculated values showed no correlation. Whether the biogas tests can be replaced, by other methods or techniques of analysis of the components and the determination of additional components for the estimation of the potential of new cultivars, should be subject of further investigations. Bioethanol yields The energy yields on the conversion pathway bioethanol without using the by-products are lower than the yields via conversion into biogas, because the ethanol fermentation is limited on material that can be converted into sugar first. The advantage of the ethanol production is a fluid fuel as result of the process. Combining the ethanol production with a biogas plant, the by-products also can be used energetically and a gaseous energy carrier can be produced. There are high potentials for the bioprocess engineering, for instance in breeding of microorganisms for the degradation of lignocellulosic biomass or of C5-sugar. Furthermore a process optimization of water and energy input is recommended. Energy and environmental balance Biogas as well as bioethanol (combined with biogas) is able to reduce the consumption of non-renewable energy carrier and its emission under the investigated scenarios and the scoop set. A future task will be the development of differentiated and well-adapted concepts on the basis of a decision between (liquid) fuels or stationary supply of thermal and electrical energy out of biomass. The aim is an efficient use of the limited areas of arable land and forests for the supply with bioenergy carriers by a useful combination of biomass, paths of utilization and conversion technique depending on natural local and regional conditions as well as the anthropogenic needs. (orig.)

  2. Investigations on an energy efficient air conditioning of hybrid vehicles and electric-powered vehicles; Untersuchungen zur energieeffizienten Klimatisierung von Hybrid- und Elektrofahrzeugen

    Energy Technology Data Exchange (ETDEWEB)

    Aurich, Joerg; Baumgart, Rico; Danzer, Christoph; Unwerth, Thomas von [Technische Univ. Chemnitz (Germany). Professur Alternative Fahrzeugantriebe

    2012-11-01

    The energy-efficient air conditioning of passenger cells is an ever-increasing challenge in the development of electric vehicles because the electric heating in particular reduces the cruising range significantly. For this reason, a simulation model has been developed at Chemnitz University of Technology, which simulates the whole air conditioning system including the passenger cell and the complete powertrain in electric cars. Using this model, different optimization approaches have been analyzed and evaluated concerning the cruising range. This paper first illustrates how much the cruising range of an exemplary electric vehicle is reduced by using the electric heating under different wintery weather conditions. Afterwards, the exploitation of the waste heat produced by the powertrain components (electric motor and power electronics) will be explained. Finally, it shall be described to what extent this exploitation increases the cruising range. (orig.)

  3. Investigations on the minimization of climatic impacts on the range of electric-powered vehicles; Untersuchungen zur Minimierung der Klimaeinfluesse auf die Reichweite von Elektrofahrzeugen

    Energy Technology Data Exchange (ETDEWEB)

    Rauh, Hubert; Hofmann, Maximilian; Maerz, Martin [Fraunhofer Institut fuer Integrierte Systeme und Bauelementetechnologie, Erlangen (Germany)

    2012-11-01

    Efficient drives and power electronics are key components for the realisation of drive trains in electric vehicles. A low energy density of the battery and little thermal loss in the electric drive train - in comparison with a combustion engine - requires efforts to acclimatise the vehicle in a way which minimises its impact on the vehicle's cruising range. Using equivalent thermal networks, Fraunhofer IISB thus develops simulation tools of passenger compartment, components of the acclimatisation system and the electric drive train. With these tools the heat flow in the passenger compartment as well as in the components of the electric drive train can be calculated. Furthermore, it is possible to compare different acclimatisation strategies as well as different topologies of the acclimatisation system. To minimize the electrical energy consumption of acclimatisation, the thermal energy needed in this process is provided by a heat pump. By preconditioning cabin, cooling circuit and drive train components while charging the battery, the energy consumption at the beginning of a drive can be further reduced, whereby the maximal cruising range at different ambient temperatures increases. (orig.)

  4. Untersuchungen zur Wirkung von Pfefferminzöl, Kümmelöl und Miglyol auf die gastrale und duodenale Motilität

    OpenAIRE

    Jung, Oliver

    2000-01-01

    Die nicht-ulzerative Dyspepsie ist eine häufige Ausschlußdiagnose bei Oberbauchbeschwerden ohne objektivierbare organische Läsion. Pathogenetisch werden unter anderem Motilitätsstörungen des Gastrointestinaltraktes beobachtet und angenommen. In einer prospektiven, offenen, kontollierten Studie wurde die Wirkung von Pfefferminzöl, Kümmelöl und Miglyol auf die gastrale und duodenale Motilität an gesunden Probanden untersucht. Als standardisiertes Meßverfahren wurde die antroduode...

  5. Experimental and theoretical studies on the vibrational structure on disperse vanadium and titanium oxide; Experimentelle und theoretische Untersuchungen zur Schwingungsstruktur an dispersem Vanadium- und Titanoxid

    Energy Technology Data Exchange (ETDEWEB)

    Nitsche, David

    2014-10-20

    By combination of FT-IR- and UV-Raman spectroscopy with normal mode analysis, this study analyzes the vibrational structure of silica supported vanadia and titania. Based on these results, structural models are developed for vanadia species under hydrated and dehydrated conditions as well as for titania species under dehydrated conditions. To this end, a novel UV-Raman setup has been developed allowing for resonance enhancement of the silica supported vanadia and titania systems. The use of a tunable solid-state laser (193-420 nm) and a triple spectrometer enables the flexibility necessary for selective resonance enhancement. In accordance with the selection rules of Raman theory the sensitivity of the method was significantly increased and made it possible, for the first time, to measure solid-state systems with a loading density of 0.00001-0.7 V nm{sup -2} and 0.0001-0.7 Ti nm{sup -2} under hydrated and dehydrated conditions. The investigated samples are based on nanostructured silicon dioxide (SBA-15), which was functionalized using an ion-exchange method and incipient wetness impregnation. UV-Vis analysis of silica supported vanadia indicated the presence of both monomeric and oligomeric surface species under hydrated and dehydrated conditions. In contrast, UV-Vis analysis of silica supported titania revealed the presence of monomeric species with both a tetrahedral and octahedral koordination. FT-IR measurements of silica supported vanadia and titania samples under dehydrated conditions showed absorption signals at 3660 and 3658 cm{sup -1}, which are consistent with stretch vibrations of hydroxylated surface species. Previous literature on silica supported vanadia has described a signal at 1020 cm{sup -1}, which could be verified by the UV-Raman method. It can be attributed to a totally symmetrical V=O stretch vibration due to the occurance of the corresponding overtone at 2039-2045 cm{sup -1}. Furthermore, under hydrated conditions at low loadings signals at 910-960 cm{sup -1} were observed which, on the basis of a combined experimental and theoretical approach, could be attributed to the interphase mode of an unhydroxylated and hydroxylated vanadia species, respectively. Regarding the silica-supported titania samples, a Raman signal at 1150 cm{sup -1} could be detected which clearly originates from the titania surface species besides the characteristic Ti-O-Si vibration. The features at 1150 cm{sup -1} is attributed to titanium atoms which are incorporated into the silica matrix within the synthesis process. In the second part of the study, normal modes of the silica supported vanadia and titania species were calculated. To establish a basis for the simulation, several monomeric and dimeric models have been developed and adapted to a POSS molecule. The models were analyzed in detail with regard to the influence of their adaption to the POSS-molecule, hydroxylation of the surface species, and oligomerization, all of which led to a more thorough understanding of the vibrational structure of silica supported surface systems. The most important insight gained from the simulation is that the assumption of a localized vibration within a diatomic oscillator does not sufficiently represent the nature of the molecular vibrations of the silica supported vanadia and titania surface species. Based on the results of the theoretical analysis, normal modes of the surface species may contain force constants of several force constants. Therefore, the force constant, which shares the highest contribution to the displacement of the inner coordinates, determines the character of the vibration. Furthermore, all models showed interphase modes which represent a momentum transfer between the silica support and the surface species. Therefore, the character of these vibrations is not determined by the surface species but rather the silica support. On the basis of a normal mode analysis, the normal modes at 1020 and 1035 cm{sup -1} were clearly identified as a V=O stretch vibrations, where the difference is caused by the phase shift between the anchoring V-O-Si vibration. By combining results from spectroscopy and simulations the surface structure of vanadia and titania species could described in detail. Under highly dispersed conditions the surface structure can not be completely described by an isolated, trigrafted species as has been traditionally proposed in the literature. Instead, the vanadia and titania surface species can oligomerize even under highly dispersed conditions. The present study shows that the assignment of Raman bands is much more complex than previously assumed. Based on a pure spectroscopic or theoretical study an unambiguous assignment of the Raman bands ist not possible. However, by combining theoretical and spectroscopic approaches, the present study succeeded in developing a more detailed picture of the surface species under hydrated and dehydrated conditions and deepening the understanding of the vibrational structure of silica supported vanadia and titania surface species.

  6. Studies on the production of building material grade slag from hazardous-waste incineration plants; Untersuchungen zur Herstellung einer Schlacke mit Baustoffqualitaet aus Sondermuellverbrennungsanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Reich, J.; Herbel, J.D.; Pasel, C. [Duisburg Univ. (Gesamthochschule) (Germany). Fachgebiet Abfalltechnik

    1998-09-01

    In an attempt to restore the competitive power of hazardous-waste incineration within the present legal framework, plant operators have in some cases lowered disposal prices below the break-even point; in this respect there is no further room for improvement. One approach towards a new marketable solution could be to use rotary kilns not only for disposal but also as production plants. This could be achieved by means of input control and loading materials. If, for example, the slag remaining after combustion could be made to meet building material specifications, thus providing a marketable product, then rotary kilns would be able to serve as production plants for a secondary raw material. If it should prove possible in the course of manufacturing campaigns to develop slags from hazardous-waste incineration plants to a marketable product, then operators will thus have complied to the demand of the Law on Recycling and Waste Management for waste avoidance and that of the Emission Control Law for residue recycling. Targeted use of suitable loading materials for quality improvement could enable operators of hazardous-waste incineration plants to secure a new strategic position on the market as building material manufacturers and utilise existing plant capacities. [Deutsch] Um die Sonderabfallverbrennung im Rahmen der rechtlichen Vorgaben wieder konkurrenzfaehig zu machen, haben die Anlagenbetreiber die Entsorgungspreise teilweise unter die Grenze der Kostendeckung zurueckgenommen; hier besteht kein Spielraum mehr. Ein neuer, marktgerechter Ansatz koennte sich dann ergeben, wenn die Drehrohroefen statt als Beseitigungsaggregate durch Inputsteuerung und Zuschlaege eventuell auch als Produktionsanlagen einzusetzen waeren. Wenn z.B. die Schlacke, als Rueckstand aus der Verbrennung, als ein im Baustoffmarkt absetzbares Produkt nach Qualitaetskriterien gezielt hergestellt wuerde, koennte der Drehrohrofen als Produktionsanlage fuer einen Sekundaerrohstoff betrieben werden. Wenn SAV-Schlacke im Rahmen eines kampagnenweisen Herstellungsprozesses zum marktfaehigen Produkt wird, kommen die Betreiber von SAV der Forderung des KrW-/AbfG nach Abfallvermeidung und dem Verwertungsgebot fuer Reststoffe des BImSchG nach. Mit dem gezielten Einsatz geeigneter Zuschlaege zur Qualitaetssteigerung koennten sich SAV als Produktionsanlagen fuer Baustoffe eine neue strategische Position im Markt sichern und ihre Kapazitaeten auslasten. (orig./SR)

  7. Supplementary investigations on the validation of the atmospheric radionuclide transport model (ARTM); Ergaenzende Untersuchungen zur Validierung des Atmosphaerischen Radionuklid-Transport-Modells (ARTM)

    Energy Technology Data Exchange (ETDEWEB)

    Richter, Cornelia; Thielen, Harald; Sogalla, Martin

    2015-09-15

    In the medium-term time scale the Gaussian plume model used so far for atmospheric dispersion calculations in the General Administrative Provision (AVV) relating to Section 47 of the Radiation Protection Ordinance (StrISchV) as well as in the Incident Calculation Bases (SBG) relating to Section 49 StrISchV is to be replaced by a Lagrangian particle model. Meanwhile the Atmospheric Radionuclide Transportation Model (ARTM) is available, which allows the simulation of the atmospheric dispersion of operational releases from nuclear installations. ARTM is based on the program package AUSTAL2000 which is designed for the simulation of atmospheric dispersion of non-radioactive operational releases from industrial plants and was adapted to the application of airborne radioactive releases. The research project 3612S50007 serves, on the one hand, to validate ARTM systematically. On the other hand, the development of science and technology were investigated and, if reasonable and possible, were implemented to the program system. The dispersion model and the user interface were advanced and optimized. The program package was provided to the users as a free download. Notably t he work program comprises the validation of the approach used in ARTM to model short emission periods, which are of interest in view of the SBG. The simulation results of the diagnostic wind and turbulence model TALdia, which is part of the GO-ARTM program package, were evaluated with focus on the influence of buildings on the flow field. The user interface was upgraded with a wind field viewer. To simplify the comparison with the model still in use, a Gaussian plum e model was implemented into the graphical user interface. The ARTM web page was maintained, user questions and feedback were answered and analysed concerning possible improvements and further developments of the program package. Numerous improvements were implemented. An ARTM user workshop was hosted by the Federal Office for Radiation Protection. The continued development and validation of ARTM has strengthened the basis for applications of this model system in line with the German regulations AVV and SBG.

  8. Ecophysiological studies on photosynthesis and pigment adaptation of light and shade leaves; Oekophysiologische Untersuchungen zur Photosynthese und Pigment-Adaptation bei Licht- und Schattenblaettern

    Energy Technology Data Exchange (ETDEWEB)

    Knapp, M.

    2005-07-01

    Photosynthetic function and pigment adaptation, as well as several other leaf parameters of light and shade adapted leaves of trees were studied under different environmental conditions. These measurements were performed primarily on a solitary standing beech during a summer drought stress period and an autumnal partial regeneration of physiological activity. Mainly investigated were beech leaves, sun leaves growing at the south side of the tree and shade leaves from the interior of the crown, since beech leaves show the strongest physiological light and shade adaptation responses among all deciduous trees. Similar adaptation studies were also performed with red, light-exposed, anthocyanin-containing leaves of the herbaceous purple foliage plant Perilla (beefsteak plant, Chinese basil) and some other plant species with either slightly or more red leaves, in order to check whether the accumulation of anthocyanins in the upper leaf epidermis of sun exposed-leaves blocks the high-light induced formation of sun-type chloroplasts. The latter are known to possess a much higher photosynthetic capacity and a different pigment composition as compared to shade-type chloroplasts of shaded green leaves. Special consideration was given to the natural drought stress effects usually occurring in the summer period (ca. end of July to end of August), caused by a combination of unfavourable weather conditions, such as a longer heat stress, with strong solar radiation and a very low rain precipitation lying clearly below the annual mean. The obtained research results provided new facts for a better understanding of the physiology of photosynthesis in sun and shade leaves of beech at both normal physiological conditions (June) and at environmental stress conditions (July, August), as well as the effect of anthocyanins on the formation of sun-type chloroplasts and their photosynthetic pigments (chlorophylls and carotenoids) in light-exposed purple foliage. (orig.)

  9. Untersuchungen zur Radiotoxizität von Tc-99m-markierten Radiotracern in vitro an FRTL-5- und A431-Zellen

    OpenAIRE

    Maucksch, Ute

    2016-01-01

    Einleitung/ Zielstellung Zusätzlich zur Gammastrahlung emittiert 99mTc ca. 5 niederenergetische Auger-Elektronen mit Reichweiten von wenigen Nanometern im Gewebe. Diese haben für die nuklear-medizinische Diagnostik keine Bedeutung. Es wird jedoch über eine therapeutische Nutzung diskutiert, wofür eine Anreicherung der Auger-Elektronen-Emitter in einem strahlensensitiven Zellkompartiment erforderlich ist. Ziel der Arbeit war es, verschiedene [99mTc]Tc-Radiopharmaka hinsichtlich ihres U...

  10. First examination of CASCADE-X-ray-detector and measurement of neutron-mirrorneutron-oscillation; Erste Untersuchungen zum CASCADE-Roentgendetektor und Messung zur Neutron-Spiegelneutron-Oszillation

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, B.

    2007-02-07

    The detection of X-radiation is of utmost importance for both fundamental physics and medical diagnostics. This work investigates whether or not the CASCADE detector working principle, first developed for the detection of neutrons, can be adapted for the detection of X-rays. This modular detector concept combines the use of a solid neutron or X-ray converter with the advantages of a counting gas detector. Thus, it gives the possibility to optimize efficiency, dynamics and spatial resolution independently. Firstly, it is necessary to find a suitable converter material that allows for the best possible detector efficiency. In order to do so, a mathematical model of the complete detector system was developed that yields the total efficiency for any given material. Respecting technical constraints, gold and gadolinium showed to be favorable choices. Based on these theoretical considerations a prototype of a CASCADE X-ray detector was built, and measurements for the determination of this detector's efficiency were conducted. In the second part of this work a CASCADE neutron detector was used to conduct the first measurement the neutron-mirrorneutron oscillation time. Mirrormatter was proposed in 1956 by Lee and Yang to allow for symmetry in the description of the universe despite the existence of parity violation. By using neutrons it was possible to determine a lower limit for the oscillation time in this work. (orig.)

  11. Investigations on the wire saw process on steels of selected geometries in the encircling process; Untersuchungen zum Seilsaegeprozess an Staehlen ausgewaehlter Geometrien im umschlingenden Verfahren

    Energy Technology Data Exchange (ETDEWEB)

    Knecht, Daniel

    2015-01-26

    This thesis illustrates a new and innovative model for the usual looping method to describe cutting time and wear. Several test series have been carried out to determine and analyze the various influencing factors. This new model now allows for exact predictions for cutting times and the resulting wear. A special test stand was planned and built. With the help of this test stand various influencing parameters were determined in preliminary tests. Due to the high correlation between these parameters, a matrix was created to rate them. From these results and the findings of the preliminary tests, the boundary conditions such as work piece size were defined and an experimental design was created. Eleven test series were conducted and each one consists of up to ten work pieces. In each test series, only one parameter was changed, the other influencing parameters remained unchanged. The parameter of the following characteristics were varied: the speed of the diamond wire, the feed pressure, the cutting angle, the geometry with respective cutting area, the work piece material, as well as the twisting of the diamond wire. By varying these parameters, the influence could be shown on the performance of the cutting process and also on the wear behavior of the diamond wire. A model was created from the obtained data which enables a cutting time prediction for rectangular work pieces. In addition to the model, a new criterion has been developed, with which it is possible to quantify the progress of wear and to be able to determine a necessary wire replacement. The classification of particle sizes of the accumulated chips has shown that a lower average cutting performance results in a decrease of the average particle size. From this circumstance a termination criterion of <150 μm has been established. When the particle size drops below this value, the cutting process becomes ineffective and should not be continued, or the diamond wire should be replaced, respectively. Furthermore, other studies were conducted to further increase the understanding of the wire cutting process. Parts of work pieces were cut in order to better analyze the local forces. An attempt was made with an underwater wire cutter to compensate for the great disadvantage of the parameter correlation in the looping method in order to achieve a better isolation of the influencing parameters. A special setup showed that the force the diamond wire applies to the work piece is slightly increased on the output side compared to the set feed force. On the work piece's inlet side this value is, if only initially, just one-third of the set feed force. Another special setup was dedicated to the examination and description of a change in the cutting angle in the course of a section using different geometries. Also, the change of the wire's contact length in different work piece shapes was determined. The resulting model provides a more efficient diamond wire cutting process because predictions of the required separation time and thereby of the accumulating wear are now possible.

  12. Spin-flip-Raman studies of semimagnetic II-VI heterostructures; Spin-flip-Raman-Untersuchungen an semimagnetischen II-VI-Halbleiter-Quantentroegen und Volumenproben

    Energy Technology Data Exchange (ETDEWEB)

    Lentze, Michael

    2009-03-18

    In the present doctoral thesis, spin flip Raman studies of semimagnetic (Zn,Mn)Se samples were in the focus of interest. Quantum wells as well as bulk-like materials were investigated. The main goal was a better understanding of the exchange interaction behaviour of heavily n-doped semimagnetic samples. The influence of doping on the exchange interaction is of special relevance with regard to spintronics applications. Several series of high quality MBE-grown (Zn,Mn)Se-samples samples were available. (orig.)

  13. Investigations concerning the effect of aluminium toxicity on the physiology and fine structures of oat plants. Physiologische und feinstrukturelle Untersuchungen zur Aluminium-Toxizitaet an Haferpflanzen

    Energy Technology Data Exchange (ETDEWEB)

    Marienfeld, S.

    1992-06-30

    In order to test the toxicity of aluminium to plants, two-week-old oat seedlings were exposed to aluminium concentrations of 0-400 [mu]M in the culture broth. Already after 12-24 hours a decrease in longitudinal root growth is to be noted, resulting from impaired mitosis activity of the root tip. This, and the observed premature cell differentiation are not aluminium-specific but unspecific reactions to unfavourable conditions. Shoot growth is only reduced after 3-4 days, and less so. Magnesium and calcium fertilization did enhance the growth of aluminium-stressed plants, but not to the level of the control plants, although the mineral concentration in the leaves reached normal values. Phosphate concentration in the root increased because of aluminium phosphate precipitation in the cell walls, which has detoxifying effect along with aluminium fixation to negative charges in the cell walls. Aluminium remains almost quantitatively in the cell wall area of the roots and is not accumulated in the cell core. Aluminium stress causes transpiration and CO[sub 2] uptake to be impaired as a reaction to the growth depression in the root area, even before the mineral concentration in the shoots is lowered. Later there follow chlorophyll depletion, chloroplast degradation, and a reduction of the leaf area. (UWA)

  14. Investigation of corrosion and wear mechanisms in hard material-reinforced duplex steel coatings; Untersuchungen zum Korrosions- und Verschleissverhalten von hartstoffverstaerkten `Duplex`-Schutzschichten. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Bouaifi, B. [Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany). Inst. fuer Schweisstechnik und Trennende Fertigungsverfahren; Goellner, J. [Technische Univ. Magdeburg (Germany). Inst. fuer Werkstofftechnik und Werkstoffpruefung

    1998-09-30

    The hard-material reinforced duplex steel coatings were deposited by plasma arc two-powder surfacing. By varying the angle of the hard materials feeding process, the deposition of the carbides was optimized so that they are deposited into the matrix in the trailing zone of the welding torch under conditions of very low thermal effects near the freezing point of the weld pool. Microstructural studies revealed that the deposition of the hard materials prevents devlopment of the typical, ferritic-austenitic microstructure of duplex steels. Due to a dissolution and diffusion process, the microstructure of the matrix takes up carbon and chromium or tungsten, depending on the carbide, thus enhancing the austenitic material in the microstructure. The wear behaviour of the surface deposits was found to be very good, wear being reduced by a factor of 6, irrespective of the type of carbide. The friction-affected surfaces showed no dissolving effects or cracking. The corrosion behaviour in sulfuric acid is also good. The welded deposits exhibited the typical behaviour of a passive material. Wear mechanisms slightly reduce the resistance. The behaviour of various specimens in artificial seawater could be distinctly assessed. Small grain fractions and pre-heating temperatures of 100 C have a beneficial effect on the corrosion resistance. The technique recommends itself for applications such as coatings for baffle plates used in flue gas desulfurisation, pipes, pump components, flanges or nozzles, or for recurrent coating of system components affected by abrasive corrosion. (orig./CB) [Deutsch] Zur Herstellung hartstoffverstaerkter Duplex-Beschichtungen wurde das Plasma-Zwei-Pulver-Auftragschweissverfahren verwendet. Hierbei wurde durch Variation des Zufuhrwinkels der Hartstoffe der Einbringungsort der Karbide optimiert, so dass diese im Nachlauf des Schweissbrenners mit sehr geringer thermischer Beeinflussung im erstarrungsnahen Schmelzbadbereich in die Matrix eingelagert werden konnten. Mikrostrukturuntersuchungen zeigten, dass sich durch die Einlagerung von Hartstoffen nicht mehr das typische ferritisch-austenitische Gefuege von Duplexstahl einstellt. Durch Aufloesung und Diffusion reichert sich das Matrixgefuege mit Kohlenstoff und je nach Karbid mit Chrom bzw. Wolfram an, was zu einer Erhoehung der austenitischen Gefuegebestandteile fuehrt. Das Verschleissverhalten der Auftragschweissungen ist sehr gut. Der Abtrag verringert sich unabhaengig von der Karbidart um den Faktor 6. Die Reibflaechen zeigen keine Ausloesungen oder Rissbildung. Das Korrosionsverhalten in Schwefelsaeure ist ebenfalls gut. Die Schweissungen zeigen das typische Verhalten eines passiven Werkstoffes. Die Bestaendigkeit sinkt etwas nach Verschleissbeanspruchung. In kuenstlichem Meerwasser ist eine gute Differenzierung einzelner Proben moeglich. Kleine Kornfraktionen und Vorwaermtemperaturen von 100 C wirken sich positiv auf die Korrosionsbestaendigkeit aus. Anwendungsmoeglichkeiten ergeben sich bei der Beschichtung von Prallblechen in REA-Becken, Rohrleitungen, Pumpenteilen, Flanschen oder Stutzen, aber auch generell fuer die Regeneration korrosiv/abrasiv beanspruchter Anlagenkomponenten. (orig.)

  15. X-ray morphometry of hip joint and pelvis in babies and infants. Roentgenmorphometrische Untersuchungen am Hueftgelenk und Becken im Saeuglings- und Kleinkindesalter

    Energy Technology Data Exchange (ETDEWEB)

    Wendl, U.

    1981-01-01

    The measurements performed in the scope of this study base on 180 pelvic scintiscans taken of children up to an age of 2 years, in whom neither a hip joint dysplasia nor a hip joint dislocation had been diagnosed. The following parameters were measured in the pelvic scintiscans: transverse diameter of the obturator foramen, distances a and b according to Schuster, angles AC and ACM, width and depth of the acetabulum, lengths of acetabulum roof and basis, width and height of the head nucleus, pelvic transverse diameter, height of the pelvis and width of the iliac bone. In the first part of the study the mean values and standard deviations of above-mentioned parameters are calculated for the respective age-groups, and the temporal and projection-dependent alterations of these values are analysed and graphically presented. Then, a typical X-ray image of a male and a female patient is given for every age-group. In the second part, the correlations between the AC or the ACM angle, respectively, and the parameters describing the properties of the acetabulum, are investigated with regard to their significance, particularly with reference to the question, which one shows better correlation. In the third part the growth of the osseous acetabulum, of the head nucleus and of the hip is investigated by means of different quotients. It results that the osseous acetabulum develops during the first two years of life a regularly concentric and unmodified sphere-shaped cap with increasing radius, which grows almost as fast as the whole pelvis. In the final discussion the results of this study are compared with those of previous ones and evaluated, with regard to their clinical significance.

  16. Studies on the reliability of fuel elements and mechanical components in nuclear power plants; Untersuchungen zur Zuverlaessigkeit von Brennelementen und mechanischen Einrichtungen in Kernkraftwerken

    Energy Technology Data Exchange (ETDEWEB)

    Elmas, Mhidi; Faust, Stephan; Fleck, Isabell; Jendrich, Uwe; Michel, Frank; Wenke, Rainer

    2016-10-15

    The general objective of the project was to elaborate the state of knowledge on the design, manufacturing and maintenance of fuel assemblies, pressure retaining components and support structures with regard to root causes of degradation during service. Conclusions were to be drawn for German plants with respect to the reliability of these structures and the effectiveness of measures and requirements in German nuclear regulations. To meet this objective, the specific German and international operating experience was evaluated. Furthermore, the conditions for design and manufacturing as well as the inspection and monitoring measures taken during manufacturing and operation were analysed. The knowledge base KompInt conserving this knowledge was updated and extended. For fuel assemblies, the evaluation of operating experience with respect to flawed manufacturing and design shows that the significance for safety was low in all cases. Some cases of fuel bow in PWR plants, however, had the potential for a higher relevance for safety. In general, the analyses show sufficient margins to failure of the mechanical design. But from the point of view of GRS, some shortcomings exist in connection with furnishing the proof regarding the behaviour of deformed fuel assemblies and spacers during accidents and earthquakes as well as with respect to the behaviour of fuel assemblies with high burn-up during handling events. A significant decrease in the number of events with pressurized components was observed at the more recent plants, which is a result of the comprehensive requirements for manufacturing, inspection, and quality assurance. The low number of reportable events related to support structures does not show any specific commonalities except those events involving anchor bolts. From a general perspective, the following common conclusions can be drawn: For most cases, sufficient reliability of the aforementioned structures was obtained by an elaborated design and quality assurance measures during manufacturing. The deteriorations found do not show up any systematic weakness in the design or gaps in the regulatory requirements. This can be stated with regard to failure-free operation as well as to the necessary precaution to prevent damage.

  17. Functional high-resolution computed tomography of pulmonary vascular and airway reactions. Experimental results. Funktionelle HR-CT der Lunge. Experimentelle Untersuchungen pulmonaler Gefaess- und Atemwegsreaktionen

    Energy Technology Data Exchange (ETDEWEB)

    Herold, C.J. (Universitaetsklinik fuer Radiodiagnostik, Vienna (Austria) Johns Hopkins Medical Institutions, Baltimore, MD (United States). Dept. of Radiology); Brown, R.H. (Johns Hopkins Medical Institutions, Baltimore, MD (United States). Dept. of Radiology Johns Hopkins Medical Institutions, Baltimore, MD (United States). Dept. of Anesthesiology and Intensive Care Medicine Johns Hopkins Medical Institutions, Baltimore, MD (United States). Dept. of Physiology); Wetzel, R.C.; Herold, S.M. (Johns Hopkins Medical Institutions, Baltimore, MD (United States). Dept. of Anesthesiology and Intensive Care Medicine); Zeerhouni, E.A. (Johns Hopkins Medical Institutions, Baltimore, MD (United States). Dept. of Radiology)

    1993-03-01

    We describe the use of high-resolution computed tomography (HRCT) for assessment of the function of pulmonary vessels and airways. With its excellent spatial resolution, HRCT is able to demonstrate pulmonary structures as small as 300 [mu]m and can be used to monitor changes following various stimuli. HRCT also provides information about structures smaller than 300 [mu]m through measurement of parenchymal background density. To date, sequential, spiral and ultrafast HRCT techniques have been used in a variety of challenges to gather information about the anatomical correlates of traditional physiological measurements, thus making anatomical-physiological correlation possible. HRCT of bronchial reactivity can demonstrate the location and time course of aerosol-induced broncho-constriction and may show changes not apparent on spirometry. HRCT of the pulmonary vascular system visualized adaptations of vessels during hypoxia and intravascular volume loading and elucidates cardiorespiratory interactions. Experimental studies provide a basis for potential clinical applications of this method. (orig.).

  18. Untersuchungen zur Erdbeerfruchtreifung : Biosynthese von 4-Hydroxy-2,5-dimethyl-3(2H)-furanon und Enzymaktivitäten während des Reifungsprozesses

    OpenAIRE

    Raab, Thomas

    2004-01-01

    Die Fruchtreifung stellt einen hochkomplexen Prozess dar, der durch eine Reihe von biochemischen und physiologischen Veränderungen gekennzeichnet ist. Dies umfasst bedeutende Veränderungen von Textur, Farbe sowie die Bildung von geschmacks- und geruchsaktiven Verbindungen. Die vorliegende Arbeit präsentiert neue Erkenntnisse zur Biosynthese von 4-Hydroxy-2,5-dimethyl-3(2H)-furanon (Furaneol®, HDMF), einer Schlüssel-Aromakomponente der Erdbeere (Fragaria x ananassa). Daneben lieferten die durc...

  19. Hydrologic investigations on construction and operation of small-scale hydropower stations in the southern Black Forest; Gewaesseroekologische Untersuchungen zum Bau und Betrieb einer Kleinwasserkraftanlage im Suedschwarzwald

    Energy Technology Data Exchange (ETDEWEB)

    Kerle, F.; Giesecke, J. [Stuttgart Univ. (Germany). Inst. fuer Wasserbau

    2003-07-01

    How far do ecologically optimized small hydropower systems (diversion type) still alter a river ecosystem? How can negative impacts be mitigated and compensated? To get more insight into these strategic important questions, a long-term case study (10 years) at the river Elz, Black Forest, has been implemented in 1999. The pre- and post-project analysis of the new 320-kW hydropower station (Wasserkraft Volk AG) uses methods of hydromorphological and biological monitoring in combination with ecological modeling (CASIMIR). After two years of hydropower operation, preliminary results show that the ecological sustainability of the directly affected river stretch (2 km) is still in good order. It can be shown that especially small fish species and earlier fish life stages profit from the water withdrawal while the habitat of adult brown trout is reduced even so an extraordinary environmental flow is released in the river bed. Restoration of riparian cover structures and foru new fishpasses help to compensate this unavoidable loss. Even if it is yet to early to audit all negative and positive aspects, the hydropower plant under investigation is an excellent example how a fair compromise between nature conservation, renewable energy supply and economics can be achieved. (orig.)

  20. Efficiencies of different flue gas purification systems in waste incinerators. Experimental report; Untersuchungen zur Effizienz von unterschiedlichen Systemen zur Rauchgasreinigung bei Muellverbrennungsanlagen. Untersuchungsbericht

    Energy Technology Data Exchange (ETDEWEB)

    Berghoff, R. (comp.)

    2001-07-01

    This investigation was carried out on behalf of the Environmental Office of the state of Nordrhein-Westfalen. Apart from the current and projected exhaust purification systems, also three exemplary systems were analyzed from the ecological and economic point of view. Effects on pollutant freights were established in consideration of energy consumption and the specific cost of waste treatment for each technology. [German] Das konkrete Ziel dieser vom Landesumweltamt NRW vergebenen Untersuchung war es, neben einer Uebersicht ueber die zzt. eingesetzten und auch geplanten Abgasreinigungssysteme (RGR) bei Muellverbrennungsanlagen, die Vor- und die Nachteile von 3 beispielhaft ausgewaehlten Systemen in einem oekologischen und oekonomischen Vergleich knapp und begrenzt darstellen zu lassen. Als Ergebnis wurden die Auswirkungen der unterschiedlichen Verfahren auf die Frachten der emittierten Schadstoffe unter Beruecksichtigung der unterschiedlichen Energieverbraeuche ermittelt und dargestellt. Darueber hinaus wurden die spezifischen Muellbehandlungskosten bei den jeweiligen Gasreinigungstechniken errechnet. (orig.)

  1. Study on the substrate-induced crystallisation of amorphous SiC-precursor ceramics. TIB/A; Untersuchungen zur substratinduzierten Kristallisation amorpher SiC-Precursorkeramiken

    Energy Technology Data Exchange (ETDEWEB)

    Rau, C.

    2000-12-01

    In the present thesis the crystallization behaviour of amorphous silicon-carbon materials (SiC{sub x}) was studied. The main topic of the experimental studies formed thereby the epitactical crystallization of thin silicon carbide layers on monocrystalline substrates of silicon carbides or silicon. Furthermore by thermolysis of the polymer amorphous SiC{sub x}-powder was obtained.

  2. Experiments on gas springs with adjustable stiffness for a free-piston engine; Experimentelle Untersuchungen an Gasfedern mit einstellbarer Kennlinie fuer einen Freikolbenmotor

    Energy Technology Data Exchange (ETDEWEB)

    Pohl, Sven-Erik; Ferrari, Cornelius; Offinger, Stefan [Deutsches Zentrum fuer Luft- und Raumfahrt (DLR), Stuttgart (Germany). Inst. fuer Fahrzeugkonzepte

    2011-04-15

    In this paper two gas spring designs for a free-piston application are experimentally investigated and evaluated. The free-piston concept demands a gas spring that allows adjustable spring characteristics during operation. Spring characteristics can be changed either by introducing gas to the cylinder or by adjusting the cylinder volume. For both concepts, experimental setups are provided. The results of the experiments are thermodynamically investigated and further compared to find the best gas spring design. The mass-variable gas spring design can be shown to be preferable over the volume-variable. (orig.)

  3. Untersuchungen zum Vorkommen von Myxobakterien in von Meerwasser beeinflußten Substraten unter besonderer Berücksichtigung der Insel Helgoland

    Science.gov (United States)

    Rückert, G.

    1984-03-01

    Representatives of the family Myxococcaceae, Myxococcus fulvus and M. virescens as well as Archangium gephyra could be isolated from marine sediments (depth range 5 58 m), collected near the island of Helgoland (North Sea); dunes and rudiments of salt marshes additionally yielded M. coralloides and the rare species Melittangium licenicola and M. boletus (Cystobacteriaceae). In soil samples from the island, M. fulvus, M. virescens, M. coralloides, A. gephyra, Cystobacter fuscus and Stigmatella erecta were found. These results were confirmed by data, obtained from the coastal zone of the island of Amrum and marine sediments from various regions. On the other hand samples from shallow fresh water (depth range 0.3 1 m) proved to be richer in species. It is assumed that the myxobacteria found in marine sediments occur as resting cells.

  4. Bericht 2005 über fazielle und biostratigraphishe Untersuchungen in der Gosau der Neualm bei Russbach am Pass Gschütt auf Blatt 95 St. Wolfgang

    Czech Academy of Sciences Publication Activity Database

    Hradecká, L.; Lobitzer, H.; Svobodová, Marcela; Švábenická, L.

    2006-01-01

    Roč. 146, 1-2 (2006), s. 132-133 ISSN 0016-7800 Institutional research plan: CEZ:AV0Z30130516 Keywords : sedimentology * paleontology * Gosau Fm., * Northern Calcareous Alps, * Austria Subject RIV: DB - Geology ; Mineralogy http://www.geologie.ac.at/filestore/download/JB1461_132_A.pdf

  5. German Roentgen Society statement on MR imaging of patients with cardiac pacemakers; Positionspapier der Deutschen Roentgengesellschaft (DRG) zu MR-Untersuchungen bei Patienten mit Herzschrittmachern

    Energy Technology Data Exchange (ETDEWEB)

    Sommer, T. [German Red Cross Hospital Neuwied (Germany). Dept. of Diagnostic and Interventional Radiology; Luechinger, R. [Zuerich Univ. (Switzerland). Inst. for Biomedical Engineering; Barkhausen, J. [University Hospital Luebeck (Germany). Dept. of Radiology and Nuclear Medicine; Gutberlet, M. [Univ. Leipzig - German Heart Center Leipzig (Germany). Dept. of Diagnostic and Interventional Radiology; Quick, H.H. [University Hospital Essen (Germany). Erwin L. Hahn Inst. for MR Imaging, High Field and Hybrid MR Imaging; Fischbach, K. [University Hospital Magdeburg (Germany). Dept. of Radiology and Nuclear Medicine

    2015-09-15

    The aim of this paper is to inform physicians, especially radiologists and cardiologists, about the technical and electrophysiological background of MR imaging of patients with implanted cardiac pacemakers (PM) and to provide dedicated clinical practice guidelines how to perform MR exams in this patient group. The presence of a conventional PM system is not any more considered an absolute contraindication for MR imaging. The prerequisites for MR imaging on pacemaker patients include the assessment of the individual risk/benefit ratio as well as to obtain full informed consent about the off label character of the procedure and all associated risks. Furthermore the use of special PM-related (e.g. re-programming of the PM) and MRI-related (e.g. limitation of whole body SAR to 2 W/kg) precautions is required and needs to be combined with adequate monitoring during MR imaging using continuous pulsoximetry. MR conditional PM devices are tested and approved for the use in the MR environment under certain conditions, including the field strength and gradient slew rate of the MR system, the maximum whole body SAR value and the presence of MR imaging exclusion zones. Safe MR imaging of patients with MR conditional PM requires the knowledge of the specific conditions of each PM system. If MR imaging within these specific conditions cannot be guaranteed in a given patient, the procedure guidelines for conventional PM should be used. The complexity of MR imaging of PM patients requires close cooperation of radiologists and cardiologists.

  6. Studies on the hazard potential of noble metal emissions from catalytic converters; Untersuchungen zur Frage des Gefaehrdungspotentials von katalysatorbuertigen Edelmetallemissionen (VPT 05)

    Energy Technology Data Exchange (ETDEWEB)

    Artelt, S [Fraunhofer-Institut fuer Toxikologie und Aerosolforschung, Hannover (Germany)

    1998-12-31

    Plants were exposed to engine exhaust fumes from engine test stands in order to estimate the probable level of platinum deposition near roads. [Deutsch] Zur Abschaetzung der zu erwarteten Platindeposition in der Naehe von Strassen wurden Pflanzen mit Motorabgasen, die aus Motorstandexperimenten gewonnen wurden, beaufschlagt. (orig.)

  7. Phlebography of the upper extremity. Pt. 1. Technique and findings in 230 examinations; Die Phlebographie der oberen Extremitaet. T. 1. Technik und Befunde bei 230 Untersuchungen

    Energy Technology Data Exchange (ETDEWEB)

    Maas, R [Radiologische Klinik des Universitaets-Krankenhauses Hamburg-Eppendorf (Germany). Abt. Roentgendiagnostik; Nicolas, V [Radiologische Klinik des Universitaets-Krankenhauses Hamburg-Eppendorf (Germany). Abt. Roentgendiagnostik; Muegge-Hamann, U [Radiologische Klinik des Universitaets-Krankenhauses Hamburg-Eppendorf (Germany). Abt. Roentgendiagnostik; Steiner, P [Radiologische Klinik des Universitaets-Krankenhauses Hamburg-Eppendorf (Germany). Abt. Roentgendiagnostik

    1995-01-01

    We report on 230 phlebographic examinations in the shoulder arm region which were performed by conventional X-ray technique and/or digital subtraction angiography (DSA). The detailed method of examination as well as anatomical variants of the vessels are explained. The group of patients was analysed concerning its composition and was subdivided with regard to clinically relevant diagnoses. Contrary to statements in the literature, the number of pathological findings in men or women were equal. The main age was between 40 and 50 years. The brachial vein was found to be doubled so often that this might be accepted as a normal situation. Phlebographic examinations were performed in the right arm twice as often as in the left one. 172 primary examinations, more than 60% showed a pathological result. (orig.) [Deutsch] Es wird ueber 230 Phlebographien der Schulter-/Armregion berichtet, die bei 172 Patienten in konventioneller und/oder digitaler Technik (DSA) durchgefuehrt wurden. Die Untersuchungstechnik wird ebenso wie anatomische Gefaessvarianten dargestellt. Das Patientenkollektiv wurde sowohl hinsichtlich seiner Zusammensetzung analysiert als auch nach klinisch relevanten Diagnosegruppen hin aufgearbeitet. Entgegen den Literaturangaben waren Patienten mit pathologischen Armphlebographien gleichhaeufig maennlich oder weiblich. Der Altersgipfel lag zwischen 40 und 50 Jahren. Die V. brachialis war so haeufig doppelt angelegt, dass dieser Befund als Normsituation angesehen werden kann. Phlebographien wurden doppelt so oft am rechten als am linken Arm durchgefuehrt. Von 172 Erstuntersuchungen erbrachten mehr als 60% einen pathologischen Befund. (orig.)

  8. Investigations of the applicability of a model-supported friction coefficient prediction model in a moving vehicle; Untersuchungen zum Einsatz eines modellunterstuetzten Reibwertvorhersagemodells im fahrenden Fahrzeug

    Energy Technology Data Exchange (ETDEWEB)

    Klempau, F. [TU Darmstadt, Fachgebiet Fahrzeugtechnik (Germany)

    2000-07-01

    In recent years driving-stability- and driver-assistance systems have become more and more common in new cars. Along with this development there is a growing demand for a system predicting the actual friction potential in the tyre contact patch. Within the European research project VERT (VEhicle Road Tyre Interaction) a big number of friction measurements were carried out to define the main influencing parameters of the tyre-road-friction-process. With the help of empirical and physical models it was possible to describe the effect of these main influencing parameters on friction values. The aim of the research work in this project is to implement these models in driving simulations as well as to consider the feasibility to implement them into real cars. This paper presents the possibilities developing a friction prediction model for implementation in a moving vehicle. (orig.) [German] U.a. wegen der zunehmenden Verbreitung von Fahrdynamik- und Fahrerassistenz - Systemen wird der Wunsch nach Kenntnis des Reibwertpotentials zwischen Reifen und Fahrbahn immer dringender. Zur Bestimmung der Einfluesse auf den Reibwert wurden im Rahmen des europaeischen Forschungsprojekts VERT, dessen Partner fzd ist, eine Vielzahl von Messungen durchgefuehrt. Ihre Auswertung ermoeglichte die Bestimmung von Haupteinflussgroessen und die Beschreibung ihrer Auswirkungen auf den Reibwert mittels empirischer und physikalischer (orig.)

  9. Incineration as a treatment option for shredder light fractions (SLF) by a stationary fluidised bed combustion; Untersuchungen zur Verbrennung von Shredderleichtfraktionen in einer stationaeren Wirbelschicht

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, Gaston

    2011-07-15

    In this paper the suitability of the stationary fluidised bed combustion as a treatment option for shredder light fractions (SLF) is discussed. This SLF, SLF coarse grain and SLF generated in a further mechanical treatment were burned. The results show a strong change in grain size distribution of the bed material during the combustion the SLF and SLF-coarse fractions. The formation of agglomerates significantly impaired the fluidization. The main reason for this effect is the high content of alkali and alkaline earth metals in the SLF. During the incineration of SLF generated by further mechanical treatment the change in grain size distribution declines much more slowly. This results from the separation of hard plastics with higher calcium contents during further mechanical processing. The tests also showed a complete burnout and a significant enrichment of metals in the solid combustion residues (fabric filter ash bed ash, cyclone ash). These residues represent a recycling concentrate, which needs to be open in the future. (orig.)

  10. Specific requirements to a gamma camera system for studies on a standing horse; Besondere Anforderungen an ein Gammakamerasystem bei Untersuchungen am stehenden Pferd

    Energy Technology Data Exchange (ETDEWEB)

    Kuehl, Thomas [MiE Medical Imaging Electronics GmbH, Seth (Germany)

    2010-03-15

    An ingenious combination of mechanics, electronics and software makes the scintigraphy on a standing horse possible. It turns out that experiences from the human medicine, such as detector specifications, measurement methods and processes, as well as many customer ideas, wishes and improvements are necessary to achieve the aim of easy, fast and robust diagnostics. (orig.)

  11. Focal breast lesions in clinical CT examinations of the chest. A retrospective analysis; Senologische Befunde bei CT-Untersuchungen des Thorax. Eine retrospektive Auswertung

    Energy Technology Data Exchange (ETDEWEB)

    Krug, Kathrin Barbara; Houbois, Christian; Grinstein, Olga; Borggrefe, Jan; Puesken, Michael; Maintz, David [Cologne Univ. Medical School, Cologne (Germany). Dept. of Diagnostical and Interventional Radiology; Hanstein, Bettina; Malter, Wolfram [Cologne Univ. Medical School, Cologne (Germany). Breast Center and Dept. of Obstetrics and Gynecology; Hellmich, Martin [Cologne Univ. (Germany). Inst. of Medical Statistics, Informatics and Epidemiology

    2017-10-15

    Based on radiological reports, the percentage of breast cancers visualized as incidental findings in routine CT examinations is estimated at ≤2%. In view of the rising number of CT examinations and the high prevalence of breast cancer, it was the goal of the present study to verify the frequency and image morphology of false-negative senological CT findings. All first contrast-enhanced CT examinations of the chest in adult female patients carried out in 2012 were retrospectively included. A senior radiologist systematically assessed the presence of breast lesions on all CT images using the BI-RADS system. All BI-RADS ≥3 notations were evaluated by a second senior radiologist. A consensus was obtained in case of differing BI-RADS assessments. Reference diagnoses were elaborated based on all available clinical, radiological and pathological data. The findings of the CT reports were classified according to the BI-RADS system and were compared with the retrospective consensus findings as well as with the reference diagnoses. The range of indications comprised a broad spectrum including staging and follow-up examinations of solid tumors/lymphoma (N = 701, 59.9 %) and vascular (190, 16.2 %), inflammatory (48, 4.1 %) and pulmonologic (22, 1.9 %) issues. BI-RADS 1/2 classifications were present in 92.5 % and BI-RADS 6 classifications were assessed in 1.7 % of the 1170 included examinations. 68 patients (5.8 %) had at least one lesion retrospectively classified as BI-RADS 3 - 5. The histological potential was known in 57 of these lesions as benign (46, 3.9 %) or malignant (11, 0.9 %). 13 BI-RADS 4/5 consensus assessments (1.1 %) were false-positive. 2 of the 10 lesions classified as being malignant based on the further clinical and radiological course were not mentioned in the written CT reports (0.2 %). Both false-negative CT reports were therapeutically and prognostically irrelevant. The relative frequency of BI-RADS 3 - 5 findings was 5.8 %. It reflects the situation encountered in clinical imaging for primarily non-senologic questions and therefore differs from what would be expected in a dedicated screening program. The rates of known false-positive BI-RADS 4/5 findings in the retrospective evaluations (1.1 %) and of false-negative findings in the written CT reports (0.2 %) reflect the different diagnostic approaches of image-based senological screening and radiological examinations indicated in order to solve clinical problems not primarily concerning the breast region. Statements regarding the prevalence of clinically occult breast cancers can only be made with caution in the presented, highly selective group of patients due to the often incomplete visualization of breast tissue and the retrospective approach. Key points Intramammary mass and non-mass lesions needing clarification may be present in up to 5.8 % of all contrast enhanced CT-examinations of the female chest. Irregular forms, unscharp/spiculated margins, inhomogeneous matrices and a pronounced contrast medium enhancement point towards a malignant genesis of an intramammary mass or non-mass lesion. The results of the study highlight the importance of paying systematical and targeted attention on senological additional findings in CT-examinations of the chest also in other clinical settings than that of the included patients in a clinic with oncological main focus.

  12. Transcriptome-wide studies of prostate cancer cell lines in the context of medical radiation; Transkriptomweite Untersuchungen von Prostata-Krebszelllinien im Kontext medizinischer Strahlentherapie

    Energy Technology Data Exchange (ETDEWEB)

    Hammer, Paul

    2012-06-26

    The use of radiotherapy in addition to chemotherapy and surgical removal is the most powerful instrument in the fight against malignant tumors in cancer medicine. After cardiovascular diseases, cancer is the second leading cause of death in the western world, in which prostate cancer is the most frequent male cancer. Despite continuous technological improvements in radiological instruments and prognosis, it may occur a recurrence up to many years after radiotherapy due to a high resistance capability of individual malignant cells of the locally occurring tumor. Although modern radiation biology has studied many aspects of the resistance mechanisms, questions are largely unanswered especially in regards to prognostic terms and time response of tumor cells to ionizing radiation. As cellular models four prostate cancer cell lines with different radiation sensitivities (PC3, DuCaP, DU-145, RWPE-1) were cultured and tested for their ability to survive after exposure to ionizing radiation by a trypane blue and MTT viability assay. The proliferative capacity of the four cell lines was determined using a colony formation assay. The PC3 cell line (radiation-resistant) and the DuCaP cell line (radiation-sensitive) showed the maximal differences in terms of radiation sensitivity. Based on these results the two cell lines were selected to allow identification of potential prognostic marker for predicting the effectiveness of radiation therapy via their transcriptome-wide gene expression. Furthermore, a time series experiment with the radiation-resistant PC3 cell line was performed. At 8 different time points, during the period from 00:00 - 42:53 (hh:mm) after exposure with 1 Gy, the mRNA was quantified by next generation sequencing to investigate the dynamic behavior of time-delayed gene expression and to discover resistance mechanisms. Of 10,966 expressed genes 730 were significant differentially expressed, determined by setting a fold change threshold in conjunction with a P-value < 0.01. Of those 305 were more strongly expressed in PC3 cell line and 425 were more strongly expressed in the DuCaP cell line. Within these 730 genes many known stress-associated genes could be found, such as the two trans-membrane protein genes CA9 and CA12, which are associated with increased radiation resistance. By calculating a network score interesting networks were derived by the GO and KEGG databases. In particular the GO categories aldehyde dehydrogenase [NAD(P)+] activity (GO:0004030) as well as the KEGG pathway of O-glycan biosynthesis (hsa00512) seems to be remarkably relevant. An interaction analysis revealed two promising networks with the transcription factors JUN and FOS as central elements. High expression of the JUN network would be stand as indicator for radiation resistance whereas a high expression of the FOS network is equated with radiation sensitivity. Interesting insights could be achieved by analyzing the 10,840 expressed genes of the PC3 cell line and its expression profile over the 8 time points. Shortly after irradiation (00:00 - 00:30) a transcriptome-wide down-regulation occurred, within the next three, short time periods (00:30 - 01:03; 01:03 - 02:12; 02:12 - 04:38) a predominant increase of gene expression and the activation of protective networks followed, such as the up-regulation of DNA repair systems or the arresting of cell cycle. In the ensuing three time periods (4:38 - 09:43; 09:43 - 20:25; 20:25 - 42:35) a balance between gene induction and suppression was present and the absolute gene expression change was increased. When comparing the gene expression prior to irradiation with the last time point (00:00 - 42:53) 2,670 genes were differentially expressed, suggesting a massive and system-wide change of gene expression. Signaling pathways such as the ATM-regulated cell cycle and apoptosis, the Nrf2 pathway after oxidative stress exposure, the DNA repair mechanisms of homologous recombination, the non-homologous end joining, the mismatch repair, base-excision repair and strand-excision repair play a major role. Very interesting are the high activity of RNA-driven events, especially activities of small nucleolar RNAs and pseudouridine processes. This suggests that these RNA-modifying networks could have a hitherto unknown functional and protective effect on cell survival after exposure to ionizing radiation. All these protective networks and their time-specific interactions are essential for the survival of cells after exposure to oxidative stress and show a complex but consistent interaction of many individual components to a system-wide running program.

  13. Investigations into the use of bacteria for enhanced recovery of petroleum; Untersuchungen zum Einsatz von Bakterien zur Erhoehung des Entoelungsgrades in Erdoellagerstaetten

    Energy Technology Data Exchange (ETDEWEB)

    Amro, M.

    1995-06-01

    Strains of bacteria were investigated with a view to their applicability and efficiency in enhanced recovery of petroleum. The mechanisms of enhanced recovery with bacteria were to be clarified as well. The experiments were carried out as static autoclave experiments without bedrock and as dynamic flooding experiments in a model pore space (Bentheim sandstone and carbonate rock) under the conditions of North German petroleum deposits. The static experiments carried out preliminary to the more time-consuming dynamic flooding experiments were to help with an optimized design of the injection experiments. (orig.) [Deutsch] Die vorliegende Arbeit hat zum Ziel, entoelungswirksame Bakterienstaemme zu untersuchen und hinsichtlich der durch sie bewirkten Erhoehung des Entoelungsgrades zu bewerten. Gleichzeitig sollen die Mechanismen aufgeklaert werden, die der Entoelungsverbesserung durch Einsatz von Bakterien zugrunde liegen. Die Experimente wurden als statische Autoklavenversuche ohne Lagerstaettengestein sowie als dynamische Flutversuche im Modellporenraum (Bentheimer Sandstein und karbonatisches Gesteinsmaterial) unter Bedingungen norddeutscher Lagerstaetten durchgefuehrt. Die statischen Versuche, die als Auswahltests den aufwendigeren dynamischen Flutversuchen vorgeschaltet waren, sollten dazu beitragen, die Flutversuche gezielt konzipieren zu koennen. (orig./EF)

  14. Dialoge in Online-Leserforen – Struktur und Gegenstand : Untersuchungen zur Markenidentifikation am Beispiel der „Locationgate“-Affäre

    OpenAIRE

    Rosumek, Anita

    2013-01-01

    Mit der Entwicklung des Social Web, also einem Internet, in dem sich immer mehr Nutzer untereinander auf Kommunikationsplattformen wie Facebook, in Foren und Bewertungsplattformen und auf Microblogging-Diensten wie Twitter austauschen, überschlagen sich Kommunikationsspezialisten mit Ratschlägen für Unternehmen, wie sie die Kommunikation im Internet insbesondere in kritischen Situationen zu gestalten hätten, und diverse Dienstleister bieten die Beobachtung (Monitoring) der Kommunikation über ...

  15. Stressors at modern workplaces. ''Technical-stres''-investigations in power plants; Stressoren an modernen Arbeitsplaetzen. Untersuchungen zum 'Technikstress' in Kraftwerken

    Energy Technology Data Exchange (ETDEWEB)

    Hoppe, Annette; Binkowski, Sven [Brandenburgische Technische Univ. Cottbus (DE). Lehrgebiet Arbeitswissenschaft/Arbeitspsycholgoie (AWIP); Haake, Dietmar [Vattenfall Europe Generation AG und Co. KG, Cottbus (Germany). Elektro- und Leittechnik

    2008-07-01

    The status analyses of power plant control rooms from the viewpoint of ergonomics and psychology is focussing on scientific analyses of stressors at highly complicated work places in order to gain further knowledge on the issue of 'technology-induced stress' and to a practical assessment of work places for the estimation of stresses. A guideline is to be developed supporting design of modern control rooms. (orig.)

  16. Untersuchungen an a-C:H:Me beschichteten Substraten zur Eignung als alternatives Bipolarplattenmaterial für wässrige Vanadium Redox-Flow Batterien

    OpenAIRE

    Richards, Justin

    2015-01-01

    Für den Auf- und Ausbau der erneuerbaren Energien sind zentrale und dezentrale Zwischenspeicherlösungen unabdingbar. Eine potentielle Technologie ist die All-Vanadium Redox-Flow Batterie. Ein essentieller Schritt für den kommerziellen Durchbruch dieser Batterie-Technologie vom Prototypenstatus zur Serienfertigung ist die Entwicklung eines kostengünstigen, elektrisch hochleitfähigen und elektrochemisch stabilen beschichteten metallischen Materials für die inneren Stromableiter (Bipolarplatten)...

  17. Theoretical investigations on improving performance of cooling systems for fuel cell vehicles; Theoretische Untersuchungen zur Kuehlleistungssteigerung durch innovative Kuehlsysteme fuer Brennstoffzellen-Elektrofahrzeuge

    Energy Technology Data Exchange (ETDEWEB)

    Reichler, Mark

    2008-04-01

    In this work theoretical investigations are carried out for cooling systems, which are used in fuel cell vehicles. This work focuses mainly on the capability of increasing the heat rejection rate by using new alternative cooling systems and by improving the conventional cooling system. Fuel cell vehicles have a higher demand of heat rejection to the ambient than comparable vehicles with combustion engine. The performance of conventional liquid cooling systems, especially at high loads and high ambient temperatures, is often not sufficient anymore. Hence, cooling systems with improved performance are necessary for fuel cell vehicles. The investigations in this work are based on DaimlerChrysler's ''A-Class'' having a PEM-Fuel Cell system integrated. Specific computational models are developed for radiators and condensers to evaluate the performance of different cooling concepts. The models are validated with experimental data. Based on an intensive investigation in the open literature the state of the art of cooling systems for fuel cell vehicles is depicted. Furthermore new cooling concepts as an alternative to the liquid cooling system are presented. The method of cooling the fuel cell by using two-phase transition shows the greatest capability to increase the cooling performance. Hence, this concept is investigated in detail. Two different concepts with three different refrigerants (R113, R245fa und R236fa) are analyzed. Cooling performance of this concept shows improvement of 18.2 up to 32.6 % compared to the conventional liquid cooling system. Thus, a two phase cooling system represents an alternative cooling system for fuel cell vehicles, which should be closer investigated by experiments. (orig.)

  18. Investigations of elementary reactions of the methyl radical with the aid of laser magnetic resonance; Untersuchungen von Elementarreaktionen des Methylradikals mit Hilfe der Laser-Magnetischen-Resonanz

    Energy Technology Data Exchange (ETDEWEB)

    Deters, R.J.

    1998-01-01

    Selected elementary reactions of CH{sub 3} radicals in an isothermal flow system in the gaseous phase were investigated by means of LMR. [Deutsch] In dieser Arbeit wurden ausgewaehlte Elementarreaktionen von CH{sub 3}-Radikalen in einem isothermen Stroemungssystem in der Gasphase mit Hilfe der Laser-Magnetischen-Resonanz untersucht. (orig.)

  19. Kinetic and spectroscopic analyses of nitryl halogenides, halogen nitrites and halogen nitrates; Kinetische und spektroskopische Untersuchungen von Nitrylhalogeniden, Halogennitriten und Halogennitraten

    Energy Technology Data Exchange (ETDEWEB)

    Benter, T.; Broeske, R.

    2001-11-01

    The available literature data of the kinetic and spectroscopic properties of nitrylhalides (XNO{sub 2}), halogennitrites (XONO) and halogennitrates (XONO{sub 2}) are incomplete and partly contradictory. Some selected reactions and UV spectra of these compounds were investigated by the use of UV/VIS and long path fourier transform infrared spectroscopy. All compounds were prepared in situ in a static reaction chamber (V=420 l) by the photolysis of X{sub 2}/NO{sub 2} (X=Cl, Br, I) mixtures in the wavelength range 300 nm{<=}{lambda}{<=}500 nm or 500 nm{<=}{lambda}{<=}700 nm in nitrogen or synthetic air. (orig.)

  20. Experimental investigations on the coolability of prototypical particle beds with respect to reactor safety; Experimentelle Untersuchungen der Kuehlbarkeit prototypischer Schuettungskonfigurationen unter dem Aspekt der Reaktorsicherheit

    Energy Technology Data Exchange (ETDEWEB)

    Leininger, Simon

    2017-02-22

    In case of a severe accident in a light water reactor, continuous unavailability of cooling water to the reactor core may result in overheating of the fuel elements and finally the loss of core integrity. Under such conditions, a structure of heat-releasing particles of different size and shape may be formed by fragmentation of molten core material in several stages of the accident. The long-term coolability of such beds is of prime im-portance to avoid any damage to the reactor pressure vessel or even a release of fission products to the environment. In the frame of this work, specific experiments were con-ducted under prototypical conditions employing the existing DEBRIS test facility in order to gain further knowledge about the thermohydraulic behavior of such beds. In steady state boiling experiments, the pressure gradients in particle beds were meas-ured both for one- and multi-dimensional cooling water flow conditions and compared with one another in order to assess the flow behavior inside the bed. For these different flow conditions as well as for stratified bed configurations, the maximum removable heat flux densities were determined in the dryout experiments. E. g., it was found that an axial stratification of the permeability can significantly reduce the bed's coolability. For the first time, the quenching behavior of dry, superheated beds was investigated at elevated system pressure up to 0.5 MPa. In these experiments, the effect of system pressure on the coolability was quantified by means of the quenching time (time period to cool down the bed to saturation temperature). The investigated particle beds mainly consisted of non-spherical particles with well-defined geometry (cylinders and screws). It was shown that the effect of the particles geometry on the flow in a particle bed can be best estimated by using an equivalent particle diameter calculated for monodisperse particle beds from the product of the Sauter diameter and a shape factor and for polydisperse beds from the surface-averaged diameter. Accompanying exemplary model calculations have confirmed the applicability of the MEWA code for assessment of the coolability of both water-saturated and dry beds. Nevertheless, the implemented friction models should be improved to better predict the pressure gradient of two-phase flows in particle beds.

  1. Generic safety issues. Evaluation of international surveys, studies and expert reports in other countries. Final report; Generische Sicherheitsfragen. Auswertungen von internationalen Untersuchungen, Studien und Gutachten anderer Staaten. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Eismar, Shanna; Wenke, Rainer

    2017-09-15

    The GeSi and GeSi-International databases developed in the predecessor projects were continued to be maintained and developed further in this project. The GeSi database serves on the one hand for reflecting the current state of the art in science and technology in the field of generic issues and also as a tool in the area of knowledge management. Hence the database can also be used very well as a steering instrument for project planning at GRS and BMUB. Within the term of the project, four issues from national and international operating experience, research results and events or accidents that occurred have been included in the database. The review of the issues contained in the database showed up the more or less strong need for revision or adaptation of a range of generic issues to the state of the art in science and technology. Due to the limited volume of the project, only those issues could be dealt with which were most in need of revision. As a result, 23 issues were subjected to a more detailed review during the project. The 7th review meeting of the contracting parties to the Convention on Nuclear Safety (CNS) was held close to the ending of this project. The national reports of the 5th, 6th and as far as possible from the 7th CNS meeting have been evaluated with respect to important generic safety issues. Within the project 13 issues could be integrated into already existing ones. Eight issues have been removed from the database. Therefore at present (September 2017), there are 288 generic safety issues in the GeSi database.

  2. Orientation guide for imaging examinations. Recommendation of the radiation protection commission. 2. rev. ed.; Orientierungshilfe fuer bildgebende Untersuchungen. Empfehlung der Strahlenschutzkommission

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    Due to the wide range of medical diagnostic method that include partially high radiation exposures of the patients (for instance CT examinations) the mean radiation exposure of the public is increasing in Germany. In 2006 the German Strahlenschutzkommission (radiation protection commission) has published a catalogue for the different diagnostic questions including recommendations for the best imaging technique. This orientation guide was actualized in 2012. The catalogue is aimed to avoid unnecessary radiation exposure and to simultaneously improve the medical diagnostics. Nevertheless the applying physician has to justify and document the selected diagnostic technique for the individual case. The guide covers the following issues: head, neck, spinal cord, skeleton and muscles, cardiovascular system, thorax, digestive system, urogenital tract, gynecology, mammary glands, trauma, oncology, pediatrics, interventional radiology.

  3. Studies on semiconductors based on InP with sub-ps response times; Untersuchungen an auf InP basierenden Halbleitern mit sub-ps Responsezeiten

    Energy Technology Data Exchange (ETDEWEB)

    Biermann, K.

    2007-06-28

    The present work describes investigation of new material concepts accomplished using molecular-beam-epitaxy (MBE) growth for application in ultra-fast photonic components. Nominally undoped and Be doped GaInAs/AlInAs multiple-quantumwell structures (MQW) were grown by MBE at growth temperatures down to 100 C (LT-MBE) on semi-insulating InP substrates. Crystalline, electric and optical properties of as-grown and annealed structures were investigated. Energy states near the conduction band of GaInAs determine the electrical and optical properties of LT-MQWs. The dynamics of charge carrier relaxation was studied by means of pump and probe experiments. Measurements of the differential transmission when excited by an additional cw laser and measurements utilizing two closely sequenced pump pulses support the capability of Be doped as-grown (annealed) LT GaInAs/AlInAs MQW structures for use in optical switches at switching frequencies in the 1 Tbit/s (250 Gbit/s) range. The voltage-induced change of interband transmission of InP based quantumcascade-lasers (QCL) during pulsed mode operation was analyzed by means of 8 band k.p calculations. The impacts of varying charge carrier distributions and of electrically heated samples can be neglected compared to the dominating effect of the electrical field on the interband transmission. The impact of MBE growth parameters on the interface quality of AlAsSb/ GaInAs heterostructures were determined by means of Hall measurements, temperature- and intensity-dependent PL measurements and spectral measurements of the interband- and intersubband-absorption. The impact of In segregation and Sb diffusion on the intersubband absorption was analyzed on the basis of bandstructure calculations. Intersubband transitions at wavelengths of about 1.8 {mu}m (1.55 {mu}m) were successfully achieved in MQW (coupled QW) structures. (orig.)

  4. Vergleichende Untersuchungen zur Widerstandsfähigkeit von \\(\\textit {Apis mellifera}\\) gegenüber \\(\\textit {Varroa destructor}\\) in Deutschland und Südafrika

    OpenAIRE

    Bosch, Christoph (M. Sc.)

    2016-01-01

    Die Milbe \\(\\textit {Varroa destructor}\\) ist einer der bedeutendsten Parasiten der Westlichen Honigbiene \\(\\textit {Apis mellifera}\\). Mit der Ausbreitung entwickelten sich \\(\\it Varroa\\)-resistenzen bei Unterarten von \\(\\textit {A. mellifera}\\). In der vorliegenden Arbeit wurden ausgewählte Faktoren, die zur Widerstandsfähigkeit beitragen können, bei der anfälligen \\(\\textit {A. m. carnica}\\) in Deutschland und der resistenten \\(\\textit {A. m. scutellata}\\) in Südafrika untersucht. Dabei wu...

  5. Das Volkslied in Deutschland, Frankreich, Belgien und Holland. Untersuchungen über die Auffassung des Begriffes; Über die traditionellen Zeilen, die Zahlen-, Blumen- und Farbensymbolik

    NARCIS (Netherlands)

    Brouwer, Cornelis

    1930-01-01

    Wenn man die gewaltige Menge Publikationen über das Volkslied, die im Laufe des 19. und 20. Jahrhunderts in Deutschland, Frankreich, Belgien und Holland erschienen sind, vergleicht, springen zwei Punkte sofort ins Auge: 1. der Unterschied zwischen den verschiedenen Auffassungen vom Begriff Volkslied

  6. Studies on cadmium exposure in the population of the Federal Republic of Germany. Untersuchungen zur Cadmiumbelastung der Bevoelkerung in der Bundesrepublik Deutschland

    Energy Technology Data Exchange (ETDEWEB)

    Ewers, U.

    1990-01-01

    The author reports on a number of studies performed on cadmium exposure in the population of the Federal Republic of Germany, in particular that of the Rhine-Ruhr region. The studies covered: - the examinations for Cd concentrations in full blood (CdB), in urine (CdU) in different population groups, and the analysis of various influencing factors; - an autopsy study involving 388 corpses from the Duesseldorf and Duisburg regions to determine the concentrations of cadmium, copper and zinc in the renal cortex - an epidemiological study on the occurrence and incidence of cadmium-induced renal function disorders in inhabitants of areas exposed to high Cd immission levels (Stolberg, Duisburg). The studies indicate CdB concentrations to be influenced by the following factors: - smoking; - age; - sex; - Cd immission level. Measurements of CdU concentrations were performed in children from Duisburg and Goch, and in women aged 65 and 66 from Stolberg, Duisburg and Duesseldorf. The results of the study performed in children did not reveal any influence of Cd immission levels. The results of the autopsy study showed that Cd concentrations in the renal cortex of persons not exposed to heavy metals occupationally, are well below the critical CdKc concentration on an average. The results of the epidemiological study on cadmium-induced renal function disorders in 286 women aged 65 and 66 from the cities of Stolberg, Duisburg and Duesseldorf revealed that no indications for renal dysfunctions clearly attributable to excessive Cd accumulation in the kidney, were verified even in a population group which had been exposed to relatively high Cd levels from the environment. (orig./MG).

  7. Cryotherapy of malignant tumors: MR imaging in comparison with pathological changes in mice; Kryotherapie maligner Tumoren: Untersuchungen mittels MRT im Tierexperiment und Vergleich mit morphologischen Veraenderungen

    Energy Technology Data Exchange (ETDEWEB)

    Romaneehsen, B.; Anders, M.; Roehrl, B.; Hast, H.J.; Schiffer, I.; Neugebauer, B.; Teichmann, E.; Schreiber, W.G.; Thelen, M. [Mainz Univ. (Germany). Klinik und Poliklinik fuer Radiologie; Hengstler, J.G. [Mainz Univ. (Germany). Inst. fuer Toxikologie

    2001-07-01

    Aim of our study was to investigate the efficacy of 7 F cryoprobes for percutaneous use morpho- and histologically, to examine the role of apoptosis after cryotherapy, and to compare contrast-enhanced MRI with histopathological findings at different time intervals in a tumor-mouse model. Methods: Percutaneous cryotherapy was performed in 15 immunocompromised nude mice with subcutaneously implanted tumors using the non-small-cell lung cancer cell line Lu 1. In group a) 7 mice were sacrificed after definite time intervals and histological examinations were done for evaluation of necrosis and apoptosis (HE; TUNEL assay); 2 mice are in long-term follow-up. In group b) in 6 mice tumor destruction and perfusion before and after freezing were investigated with native and contrast-enhanced MR imaging (T{sub 1}- and T{sub 2}-weighted spin-echo) and compared with histopathological findings. Histological control were done in 2 untreated mice. Results: We observed fast tumor-reduction within two weeks (ca. 50%). On long-term follow-up (> 6 months) no recurrence has been noticed so far. Tumors were well vascularized prior to treatment and did not-show contrast enhancement an any time after cryotherapy. A narrow contrast-enhanced zone was seen on the tumor border subcutaneously as a sign of peripheral hyperemia and central vascular stasis after cryotherapy. On histology there was evidence of both apoptosis and necrosis. (orig.) [German] Evaluierung der Durchfuehrbarkeit und Effizienz einer perkutanen Kryotherapie mittels 7-F-Kryosonde in Nacktmaeusen. Erheben des histopathologischen Befundes der Kryolaesion nach definierten Zeitintervallen und Ueberpruefung einer moeglichen Rolle der Apoptose nach Kryotherapie. Darstellung morphologischer Veraenderungen des Tumors und des angrenzenden Gewebes im Anschluss an die Kryotherapie mittels kontrastmittelunterstuetzter MRT. Methodik: Zweiminuetige Kryotherapie subkutan implantierter Tumoren eines nicht-kleinzelligen Bronchialkarzinoms (Lu1-Zellreihe) bei 15 Nacktmaeusen. Gruppe a (9 Tiere): Praeparation und histomorphologische Begutachtung (HE-Faerbung; TUNEL-Assay) von 7 Tieren nach 0-28 Tagen; Langzeitverlauf von zwei Tieren. Gruppe b: zusaetzliche MRT-Untersuchung von 6 Tieren vor sowie zu definierten Zeitintervallen nach der Kryotherapie mittels T{sub 1}- und T{sub 2}-gewichteter sowie kontrastverstaerkter T{sub 1}-gewichteter Spin-Echo-Sequenzen und anschliessende Praeparation. Vergleichende histologische Kontrolluntersuchung an unbehandelten Maeusen. Ergebnisse: Rasche Tumorverkleinerung nach Kryotherapie (50% innerhalb zwei Wochen) und narbige Ausheilung mit einer rezidivfreien Ueberlebenszeit von ueber 6 Monaten bei zwei Maeusen. In der nach der Kryotherapie durchgefuehrten MRT fehlende Kontrastmittelanreicherung im behandelten Gewebe mit stark anreicherndem Randsaum als Zeichen einer zentralen Stase und peripheren Hyperaemie. Histologisch zunehmende, nach 4 Tagen fast vollstaendige Nekrose des eingefrorenen Bezirkes sowie Apoptose-positive Kerne im TUNEL-Assay. (orig.)

  8. Study on the effects of physical plasma on in-vitro cultivates cells; Untersuchungen zum Einfluss von physikalischem Plasma auf in vitro kultivierte Zellen

    Energy Technology Data Exchange (ETDEWEB)

    Strassenburg, Susanne

    2014-03-15

    This study focused on the interactions of non thermal atmospheric pressure plasma on in vitro cultured keratinocytes (HaCaT keratinocytes) and melanoma cells (MV3). Three different plasma sources were used: a plasma jet (kINPen 09), a surface DBD (dielectric barrier discharge) and a volume DBD. For analyzing basic effects of plasma on cells, influence of physical plasma on viability, on DNA and on induction of ROS were investigated. Following assays were used: -- Viability: - neutral red uptake assay, cell counting (number of viable cells, cell integrity) - BrdU assay (proliferation) - Annexin V and propidium iodide staining, flow cytometry (induction of apoptosis), -- DNA: - alkaline comet assay (detection of DNA damage) - staining of DNA with propidium iodide, flow cytometry (cell cycle analysis), -- ROS: - H2DCFDA assay, flow cytometry (detection of ROS-positive cells). In addition to the effects which where induced by the plasma sources, the influence of the plasma treatment regime (direct, indirect and direct with medium exchange), the working gas (argon, air) and the surrounding liquids (cell culture medium: RPMI, IMDM; buffer solutions: HBSS, PBS) on the extent of the plasma cell effects were investigated. All plasma sources induced treatment time-dependent effects in HaCaT keratinocytes and melanoma cells (MV3): - loss of viable cells and reduced proliferation - induction of apoptosis after the longest treatment times - DNA damage 1 h after plasma treatment, 24 h after plasma treatment DNA damage was present only after the longest treatment times, evidence for DNA damage repair - due to accumulation of cells in G2/M phase, cell count in G1 phase (24 h) is lower - increase of ROS-positive cells 1 h and 24 h after plasma treatment. It was shown that cells which were cultured in RPMI showed stronger effects (stronger loss of viability and more DNA damage) than cells which were cultured in IMDM. Also plasma-treated buffer solutions (HBSS, PBS) induced DNA damage in HaCaT cells. Direct and indirect plasma treatment caused almost the same effects. A subsequent culture medium exchange diminished the measured effects. It seems to be that next to the kind of liquids and the plasma treatment time the incubation period of the cells with the plasma-treated liquid plays an important role. The plasma-generated reactive species can react with the water molecules and the organic compounds of the culture medium and create long living species (e.g. H2O2) which can interact with the cellular molecules. The other plasma components such as UV light and electric and magnetic fields seem to play only a secondary role in the plasma-cell interaction, because these components come only in contact with the cells during direct plasma treatment and cannot cause the strong effects seen after indirect plasma treatment. The surface DBD used in these studies was applied with air or argon. Argon-generated plasma induced effects on a lower level compared to air plasma effects. Air plasma comprises ROS and RNS in the gas phase. RNS are missing in argon plasma and can therefore not interact with the cells. In addition to the keratinocytes human melanoma cells were treated with the surface DBD (air). Compared to HaCaT cells reduced plasma treatment times resulted in biologically equivalent effects in melanoma cells. The test methods used here are suitable for the biological characterization of new plasma sources or for analyzing plasma-cell interaction of further cell lines. Further investigations should follow e.g. the specification of the plasma induced oxidative DNA damage and the resulting repair mechanisms.

  9. PET-Studies in parkinson's disease; Untersuchungen mit der Positronen-Emissions-Tomographie (PET) bei Patienten mit Morbus Parkinson

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, J. [Klinik fuer Neurologie, Univ. Leipzig (Germany)

    2002-09-01

    Positron-emission-tomography (PET) has enabled to study the metabolism and blood flow in specific brain areas. Besides, there is a variety of radiotracers that allow quantification of the function of distinct molecules. In respect to Parkinson's disease, PET allowed for the first time to assess the number of dopaminergic neurons in vivo. Thus, helping confirming a dopaminergic deficit, measuring disease progression and also help to determine the function of dopaminergic grafts. Current research has shifted to determine the role of related neurotransmitter systems in the pathophysiology of Parkinson's disease. (orig.) [German] Die positronen-emissions-tomographie (PET) bietet neben der Messung von Metabolismus und Blutfluss die Moeglichkeit der Darstellung von einzelnen Molekuelen. Bei Patienten mit Morbus Parkinson hat es diese Technik erstmals erlaubt, die Anzahl der dopaminergen Neurone zu quantifizieren, wodurch die Diagnose gesichert, die Progression der Erkrankung beurteilt und auch das Anwachsen von Implantaten beurteilt werden kann. Die PET hat einen wesentlichen Beitrag zu unserem heutigen Wissen ueber die Pathophysiologie dieser Erkrankung beigetragen. (orig.)

  10. Numerische und experimentelle Untersuchungen zur Beschreibung der Wirkungsweise und Effektivität von grossflächigen hochsensitiven SPNDs : Self-Powered-Neutron-Detectors

    OpenAIRE

    Al-Dabagh, D.

    1981-01-01

    In the present work the neutron sensitivity of large surface "Self-Powered- Neutron-Detectors«SPNDs) is determined numericaily and experimentally. First a computer model for the parametric caIculation of the (n,$\\gamma$)-reaction rates in the emitter of the SPND was developed under use of the Monte-Carlo-Program KENO 11 ‘To determine the escape-probability of the electrons produced via Comptonor photoelectric effect by the emitter as weil as fron the surrounding isolator, a new Monte-Carlo-Pr...

  11. Investigations on the effect of creep stress on the thermal properties of metallic materials; Untersuchungen zum Einfluss der Zeitstandbeanspruchung auf die thermischen Eigenschaften metallischer Werkstoffe

    Energy Technology Data Exchange (ETDEWEB)

    Radtke, U [Univ. Dortmund (Germany); Crostack, H A [Univ. Dortmund (Germany); Winschuh, E [Siemens KWU, Offenbach (Germany)

    1996-12-31

    Using thermal wave analysis with front side infrared detection on sample material damaged by creep, one examines whether the creep stress has an effect on the thermal material properties and to what effect this can be used to estimate the remaining service life. (orig.) [Deutsch] Unter Anwendung der Waermewellenanalyse mit frontseitiger Infrarotdetektion auf zeitstandgeschaedigtes Probenmaterial wird untersucht, ob die Zeitstandbeanspruchung einen Einfluss auf die thermischen Werkstoffeigenschaften hat und inwieweit dieser zur Abschaetzung der Restlebensdauer genutzt werden kann. (orig.)

  12. Component behaviour in the 700 C power plant. Numerical and experimental investigations; Komponentenverhalten im 700 C-Kraftwerk. Numerische und experimentelle Untersuchungen

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Kay H.

    2013-07-19

    Currently martensitic steels are used in fossil fired power plants with maximum working temperatures up to 625 C. These steels do not show the required creep rupture strength at the target temperature of 700 C. For these high temperatures, new materials like the nickel base alloys have to be qualified for power plants services. Originating from the weld of turbine materials, nickel base alloys show outstanding creep rupture strength. An alloy with good prospects out of the material class of the nickel base alloys is Alloy 617 mod. However, this material is expensive due to its high nickel content. Furthermore, the complex machinability of this material leads to an additional increase in expenses. A complete fabrication of the boiler area using Alloy 617 mod is not economically feasible, which means that the usage of this material has to be limited to the temperature weld of 625 C to 700 C. For the boiler area with temperatures below 625 C the well proven 9 % to 12 % Cr-steels, like T/P92 and VM12/VM12-SHC may be used. In the weld of low temperatures up to 525 C the usage of the 2.5 % Cr-steel T/P24 offers numerous advantages, in particular in the fabrication of membrane walls. This material shows good creep properties up to temperatures of 525 C and, for thin walled components, T24 can be welded without post weld heat treatment by using suitable techniques. For a successful design and fabrication of a 700 C fossil fired power plant, appropriate materials have to be qualified. Here, a special focus is set on the creep properties of these materials. The presented work is a significant contribution to the qualification of these materials. First, the materials Alloy 617 mod, T/P92, VM12/VM12-SHC and T24 are briefly introduced and characterized. After this, the materials are investigated in a detailed creep testing program. This program includes investigations on base material, extracted from tubes, pipes and inductive bends of pipes. In addition, crossweld specimens and specimens made of weld material are creep tested at high temperatures. To gain important information about the behavior under service conditions and multiaxial loadings, a test rig was developed at MPA Universitaet Stuttgart, which is able to test membrane-wall like components under this point of view. The applied mechanical and thermal loads in these tests are dimensioned to cause a status of high damage within the investigated materials after a test time of 2.000 h to 5.000 h. After the test procedure, the membrane-wall like specimens are metallographically investigated. The objectives of these investigations are the characterization of the actual damage within the material caused by the prior testing, in particular within the tube-fin-welds and furthermore to identify the area of crack formation. Besides the characterization and qualification of the materials for the construction of components of a high temperature fossil fired power plant with a peak temperature of 700 C the results of the uniaxial creep test will be used to develop material models for inelastic finite element simulations. For this a creep equation based on a formulation of Graham and Walles will be modified and furthermore extended with a damage parameter. By simulating the component tests presented in this work, the created material models (including three heat affected zones) could be verified. However, it becomes obvious that irregulations in geometry in a tube-fin-weld of a waterwall may exist and may lead to an additional bending load. By evaluating the damage parameter, which is implemented in the used creep equation, the local creep strains and the multiaxiality of the stress state, the area of maximum creep damage and with this the location of crack formation can be precisely predicted in the heat affected zone on the tube side, close to the surface of the tube-fin-weld. The acquired results show, that modern FE codes in combination with suitable creep equations are a powerful tool to support the design process of power plant components. Finally, the results in this work allow the conclusion that with the help of the introduced modified creep equation of Graham and Walles a numerical simulation of high temperature loaded boiler components is possible. Furthermore the data base for design and dimensioning processes of power plant components in the creep regime was extended with reliable data. In addition to that the qualification of the materials Alloy 617 mod, T/P92, VM12/VM12-SHC and T24 for the usage in fossil fired power plants with temperatures up to 700 C was furthered.

  13. Studies on the nondestructive emittance measurement at a negative-hydrogen-ion beam; Untersuchungen zur zerstoerungsfreien Emittanzmessung an einem negativen Wasserstoffionenstrahl

    Energy Technology Data Exchange (ETDEWEB)

    Gabor, C.

    2007-07-01

    In the present thesis the already known idea to apply photodetechment for the diagnosis at a H{sup -} beam has be newly interpretated and improved. Thereby a nondestructive emittance measurement method was developed, which is especially suited for future high-current accelerator projects. For emittance measurements thereby mechanical components can be totally abandoned, if at a small part of the H{sup -} ions the additional with only 0.754 eV weak bound electron is separated by photodetachment {Dirac_h}{omega}+H{sup -}{yields}H{sup 0}+e{sup -}. The neutralized H{sup -} ions can be magnetically or electrostatically separated from the electrons and the remaining H{sup -} ions. Especially the neutral particles are offered by their insensitivity against external electromagnetic fields for the determination of the phase-space distribution of the ion beam. Also the momentum transfer by photodetechment can be neglected at the neutralized ions. The detection of the divergence angle has been pursued by a scintillator with a CCD camera. For the calculation of the number of neutralized particles a simplified model under assumption of homogeneous density distributions was developed. The aim of the approximation was to make statements about the requirement on the laser system and the detector. Thereby especially the suitability of the measurement for high beam currents and beam parameters, as they are typically present behind a RFQ. Further aspects like the influence of the angle between laser and ion beams, relativistic ion beam, as well as the position and angular resolution have been also object of the discussion.

  14. Hydraulic investigations for the construction of a fishway in Lauffen at the river Neckar; Hydraulische Untersuchungen zum Bau einer Fischaufstiegsanlage in Lauffen am Neckar

    Energy Technology Data Exchange (ETDEWEB)

    Heinzelmann, Christoph; Weichert, Roman; Wassermann, Stefanie [Bundesanstalt fuer Wasserbau, Karlsruhe (Germany)

    2013-03-01

    As service provider for the Federal Waterways and Shipping Administration (Wasser- und Schifffahrtsverwaltung des Bundes, WSV) the Federal Waterways Engineering and Research Institute (Bundesanstalt fuer Wasserbau, BAW) provides advice for the offices of the WSV regarding the river continuity of Federal waterways. In this context, the investigations of BAW concentrate on hydraulic and waterways engineering aspects. This article reports on current investigations for the construction of a fishway at the barrage Lauffen, River Neckar. Field investigations as well as physical and numerical model simulations are used. (orig.)

  15. Studies on layer growth and interfaces on Ta-base thin layers by means of XPS; Untersuchungen zu Schichtwachstum und Grenzflaechen an Ta-basierten Duennschichten mittels XPS

    Energy Technology Data Exchange (ETDEWEB)

    Zier, M.

    2007-11-02

    In this thesis studies on the growth and on the formation of the interfaces of Ta and TaN layers on Si and SiO{sub 2} were performed. In the system TaN on SiO{sub 2} no reaction on the interface could be found. As the system with the mostly disturbed interface Ta on SiO{sub 2} was proved. Here a reduction of the SiO{sub 2} at simultaneous oxidation of the Ta was to be observed. Additionally tantalum silicide was formed to be considered concerning the bonding state as Ta{sub 5}Si{sub 3}, from which a double layer of a tantalum silicide and a tantalum suboxide resulted. A whole thickness of the double layer of above 1 nm resulted. In the system Ta on Si at the deposition of the film on the interface a tantalum silicide was formed to be characterized concerning the bonding state as TaSi{sub 2}. The thickness of the interlayer growed thereby up to 0.8 nm in form of islands. Finally in the system TaN on Si a silicon nitride formation during the deposition was observed, which was attributed to the insertion of adsorbed nitrogen from the sputtering atmosphere by recoil implantation of the sputtered Ta atoms. The silicon nitride interlayer growed thereby up to a thickness of 0.8 nm.

  16. State of the art for noise reduction in biogas plants. Sound technical analyses, research, investigations; Stand der Technik zur Laermminderung bei Biogasanlagen. Schalltechnische Analysen, Recherchen, Untersuchungen

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2014-05-15

    Approximately 480 biogas plants are currently being built in Mecklenburg-Vorpommern, which were mainly built in an agricultural context. At the beginning of 2014 about 15 percent of the country's electricity was generated by domestic biogas plants. This publication is intended to serve as a guide to the authorities, planners and engineers, in order to be able to plan, erect and operate biogas plants in the most conflict-free manner. [German] In Mecklenburg-Vorpommern werden derzeit ca. 480 Biogasanlagen betrieben, die vorwiegend in einem landwirtschaftlichen Kontext errichtet wurden. Anfang des Jahres 2014 wurde etwa 15 Prozent des Stroms im Land durch einheimische Biogasanlagen erzeugt. Diese Veroeffentlichung soll den Behoerden, Planern und Ingenieurbueros als Handlungsleitfaden dienen, um Biogasanlagen unter Beruecksichtigung des Standes der Technik moeglichst konfliktfrei planen, errichten und betreiben zu koennen.

  17. Investigations of coal ignition in a short-range flame burner using optical measuring systems; Untersuchungen zur Kohlezuendung am Flachflammenbrenner unter Verwendung optischer Messtechnik

    Energy Technology Data Exchange (ETDEWEB)

    Hackert, G.; Kremer, H.; Wirtz, S. [Bochum Univ. (Germany). Lehrstuhl fuer Energieanlagentechnik

    1999-09-01

    The short-range flame burner and the KOALA reactor of DMT are experimental facilities for realistic simulation of coal conversion processes at high temperatures and pressures in atmospheric conditions. The TOSCA system enable measurements of temperatures, sizes, shapes and velocities of the fuel particles, which serve as a basis for a three-dimensional simulation model of coal combustion. In the future, further parameter studies will deepen the present knowledge of coal dust combustion under pressure and enable optimisation of the numerical models for simulation of industrial-scale systems for coal dust combustion under pressure. [Deutsch] Mit dem Flachflammenbrenner und dem KOALA-Reaktor der DMT stehen Versuchsapparaturen zur Verfuegung, mit deren Hilfe die Kohleumwandlungsprozesse bei hohen Temperaturen unter Druck und unter atmosphaerischen Bedingungen realistisch wiedergegeben werden. Das TOSCA-System erlaubt dabei die Bestimmung von Temperaturen, Groessen, Formen und Geschwindigkeiten der Brennstoffpartikel. Diese Daten liefern die Grundlage fuer die Erstellung eines dreidimensionalen Simulationsmodells zur Modellierung der Kohleverbrennung. In Zukunft werden weitere Parameterstudien das Verstaendnis der Kohlenstaubdruckverbrennung vertiefen und ein Optimierung der numerischen Modelle ermoeglichen, so dass die Simulation grosstechnischer Kohlenstaubdruckverbrennungsanlagen realisiert werden kann. (orig.)

  18. Experimental and theoretical investigation of the pressurized coal dust furnace of RWTH Aachen; Experimentelle und theoretische Untersuchungen an der Druckkohlenstaubfeuerung der RWTH Aachen

    Energy Technology Data Exchange (ETDEWEB)

    Renz, U. [Technische Hochschule Aachen (Germany). Lehrstuhl fuer Waermeuebertragung und Klimatechnik

    1999-09-01

    The contribution presents first results and activities funded by the BMBF, the MSWWF of Nordrhein-Westfalen, and the RWTH Aachen. The main component of the Dorsten plant is the pressure chamber which was designed and constructed in close cooperation with Messrs. L. und C. Steinmueller. The combustion chamber was installed inside the pressure vessel of the former pressurized fluidized bed steam generator of the heating power station of the RWTH Aachen. The combustion chamber is designed for a thermal power of 400 kW, corresponding to a coal mass flow of about 50 kg/h, at a pressure of 12 bar and temperatures up to 1700 degrees centigrade in melting chamber operation. It is vertical, with an inner diameter of about 400 mm, an axially movable roof burner, and four points for optical access. [Deutsch] Die Auslegung des Brenners un der Brennkammer fuer die Druckkohlenstaubfeuerung (DKSF) in Hinblick auf eine vollstaendige und stabile Verbrennung bei moeglichst geringen Emissionen an Schadgasen und Aschepartikeln war dagegen nicht primaeres Ziel des Verbundvorhabens in Dorsten. Dieses Thema wird in enger Abstimmung mit den Dorstener Aktivitaeten an einer Versuchsanlage der RWTH Aachen angegangen. Ueber die ersten Ergebnisse und die geplanten Arbeiten, die vom BMBF, vom MSWWF des Landes NRW und der RWTH Aachen gefoerdert werden, soll im Beitrag berichtet werden. Die Hauptkomponente der DKSF-Anlage ist die Druckkammer, die in enger Zusammenarbeit mit der Firma L. und C. Steinmueller ausgelegt und aufgebaut wurde. Die Aufstellung der Brennkammer im Druckbehaelter des ehemaligen Druckwirbelschicht-Dampferzeugers im Heizkraftwerk der RWTH Aachen wird aufgezeigt. Die Brennkammer ist fuer eine thermische Leistung von 400 kW, entsprechend einem Kohlenmassestrom von etwa 50 kg/h, bei einem Druck von 12 bar und fuer Temperaturen bis zu 1.700 C bei Schmelzkammerbetrieb ausgelegt. Sie ist als stehender Druckbehaelter mit einem Innendurchmesser von ca. 400 mm, einem axial verfahrbaren Deckenbrenner und mit vier optischen Zugaengen ausgefuehrt. (orig. AKF)

  19. Intertextuelle und intramediale Bezüge als Orientierungsangebot – systematische Überlegungen und exemplarische Untersuchungen zu Verweisen auf das Fernsehangebot

    Directory of Open Access Journals (Sweden)

    Ben Bachmair

    2017-07-01

    Full Text Available Auch wenn das Internet sich weder so schnell noch so nachhaltig im Alltag und als Bestandteil von Massenkommunikation etablierte, wie es Ende der neunziger Jahre den Anschein hatte, so zeigt sich am Internet doch, was sich mit der Vernetzungs- und Verfügbarkeitslogik verändern könnte, die dem Internet zu eigen ist. Manuel Castells (2001 mit seiner Analyse des „Informationszeitalters“ und der als instrumentellem Netzwerk organisierten Gesellschaft skizziert die Umrisse, wie sich unsere Gesellschaft mit welcher Dynamik entwickelt. Er spricht von einer „informationeilen Entwicklungsweise“ (ebd., S. 17, die anders als die „agrarische“ oder die „industrielle“ auf das gesellschaftliche Verhältnis der Menschen zur Natur („Produktion“, zu sich selber („Erfahrung“, „kulturelle Identität“ und zu anderen (.Macht“ einwirkt. Einen Aspekt dieser „informationellen Entwicklungsweise“ beschreibt Castells mit dem Hinweis auf „globale Netzwerke der Instrumentalität“, die eine „unüberschaubare Anzahl virtueller Gemeinschaften“ hervorbringt (ebd., S. 23. Dabei konstituiert sich auch eine Art von Subjektivität, die sich im Moment als „zunehmende Distanz zwischen Globalisierung und Identität, zwischen dem Netz und dem Ich“ beschreiben lässt (ebd., S. 24. In dieser Spannung bekommt .Multimedia“ die Funktion einer „symbolischen Umwelt“ (ebd., S. 415.

  20. Experimental investigations of the geomechanical behaviour of plastic sealing sheets for sealing dumps. Final report; Experimentelle Untersuchungen zum geomechanischen Verhalten von Kunststoffdichtungsbahnen in Dichtungssystemen fuer Deponiebasisabdichtungen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Schreyer, J; Wiesbaum, E

    1991-12-01

    Due to more severe environmental requirements, dumps have to be largely sealed to prevent harmful substances escaping into the environment and according to the state of technology, this is done by the combination of clay and plastic sealing tracks. Building on the knowledge from a completed research project `On the investigation of possibilities related to applications of a process for testing the mechanical behaviour of dump base seals made from sealing sheets`, the test processes described there were developed further and proposals were worked out for standardized execution of experiments. With the aid of a large number of experiments, minimum requirements were determined, which should serve to define the geo-mechanical properties of the plastic sealing sheets and to determine binding limits. (BBR). [Deutsch] Aufgrund schaerferer Umweltschutzauflagen muessen Deponien zur Verhinderung des Schadstoffaustritts in die Umwelt weitgehend abgedichtet werden, dem Stand der Technik entsprechend durch die Kombination von Tonen und Kunststoffdichtungsbahnen. Aufbauend auf den Erkenntnissen eines bereits abgeschlossenen Forschungsvorhabens `Zur Untersuchung der anwendungsbezogenen Moeglichkeiten eines Verfahrens zur Pruefung des mechanischen Verhaltens von Deponiebasisabdichtungen aus Dichtungsbahnen` wurden die dort beschriebenen Pruefverfahren fortentwickelt und Vorschlaege zur standardisierten Versuchsdurchfuehrung ausgearbeitet. Mit Hilfe einer groesseren Anzahl von Versuchen wurden Mindestanforderungen bestimmt, die dazu dienen sollen, geomechanische Eigenschaften der Kunststoffdichtungsbahnen zu definieren und verbindliche Grenzwerte festzulegen. (BBR).

  1. Untersuchungen zur Expansion, funktionellen Charakterisierung und kontinuierlichen Bereitstellung von Hepatocyten für die Anwendung in bioartifiziellen Leberunterstützungssystemen

    OpenAIRE

    Iding, Kai

    2001-01-01

    Der vollständige Funktionsverlust der Leber kann in der modernen Medizin bisher nur durch den Austausch des funktionsuntüchtigen gegen ein gesundes Organ, d.h. durch eine Lebertransplantation behandelt werden. Da es jedoch weit mehr transplantationsbedürftige Patienten gibt als geeignete Spenderorgane zur Verfügung stehen, gibt es weltweite Anstrengungen zur Entwicklung alternativer Behandlungsmethoden. Nach bisherigem wissenschaftlichen Erkenntnisstand ist die bioartifizielle Leberunterst...

  2. Studies on the safety and transmutation behaviour of innovative fuels for light water reactors; Untersuchungen zum Sicherheits- und Transmutationsverhalten innovativer Brennstoffe fuer Leichtwasserreaktoren

    Energy Technology Data Exchange (ETDEWEB)

    Schitthelm, Oliver

    2012-07-01

    Nuclear power plants contribute a substantial part to the energy demand in industry. Today the most common fuel cycle uses enriched uranium which produces plutonium due to its {sup 238}U content. With respect to the long-term waste disposal Plutonium is an issue due to its heat production and radiotoxicity. This thesis consists of three main parts. In the first part the development and validation of a new code package MCBURN for spatial high resolution burnup simulations is presented. In the second part several innovative uranium-free and plutonium-burning fuels are evaluated on assembly level. Candidates for these fuels are a thorium/plutonium fuel and an inert matrix fuel consisting of plutonium dispersed in an enriched molybdenum matrix. The performance of these fuels is evaluated against existing MOX and enriched uranium fuels considering the safety and transmutation behaviour. The evaluation contains the boron efficiency, the void coefficient, the doppler coefficient and the net balances of every radionuclide. In the third part these innovative fuels are introduced into a German KONVOI reactor core. Considering todays approved usage of MOX fuels a partial loading of one third of innovative fuels and two third of classical uranium fuels was analysed. The efficiency of the plutonium depletion is determined by the ratio of the production of higher isotopes compared to the plutonium depletion. Todays MOX-fuels transmutate about 25% to 30% into higher actinides as Americium or Curium. In uranium-free fuels this ratio is about 10% due to the lack of additional plutonium production. The analyses of the reactor core have shown that one third of MOX fuel is not capable of a net reduction of plutonium. On the other hand a partial loading with thorium/plutonium fuel incinerates about half the amount of plutonium produced by an uranium only core. If IMF is used the ratio increases to about 75%. Considering the safety behavior all fuels have shown comparable results.

  3. Spectroscopic study on the doping of polycrystalline CdTe layers for solar cells; Spektroskopische Untersuchungen zur Dotierung von polykristallinen CdTe-Schichten fuer Solarzellen

    Energy Technology Data Exchange (ETDEWEB)

    Kraft, Christian

    2011-11-29

    First in the present thesis the fundamental properties of CdTe are described. In the following it is discussed, how a CdTe solar cell is generally constructed, which specialities are to be regarded, and how an improvement of the actually reachable data of such a solar cell in view of the efficiency can be reached fundamentally and in then practical realization. In the third chapter the physical foundations of the most important methods are discussed, which are applied in the framework of this thesis for the analysis of the CdTe layers. The fourth chapter describes the details of the experiments of this thesis. The fifth chapter deals with the analysis of the photoluminescence of CdTe layers. Special attention is put on the analysis of the excitonic luminescence. The sixth chapter treats the implantation of CdTe layers with phosphor. The influence of phosphorus as dopant on the PL spectra of CdTe and the correponding characteristics of implanted solar cells are presented. Also the influence of radiation damages as consequence of the ion implantation is studied in this chapter by means of the analysis of differently thick absorber layers. In the seventh chapter finally a new procedure for the fabrication of solar cells on the base of CdTe as absorber material is introduced, which shall make possible to change the stoichiometry of cadmium mand tellurium specifically and to present additionally a suited material, in order to form the doping of CdTE a solar-cell material variably. The fundamental properties of the new facility are experimentally determined, and first solar cells are fabricated with this facility and analyzed. Also an in-situ doping with phosphorus is thereby performed and the result studied.

  4. Comparative studies in farther-reaching waste water cleaning in different reactor systems; Vergleichende Untersuchungen zur weitergehenden Abwasserreinigung in unterschiedlichen Reaktorsystemen

    Energy Technology Data Exchange (ETDEWEB)

    Dockhorn, T. [Technische Univ. Braunschweig (Germany). Inst. fuer Siedlungswasserwirtschaft

    1999-07-01

    Three semi-technical pilot plants (completely mixed reactor, cascade, SBR) were operated in parallel under equal starting conditions. The influence of the type of reactor on the processes COD elimination, nitrification, denitrification and biological P elimination under operating conditions was studied. (orig.) [German] Es wurden drei halbtechnische Versuchsanlagen (volldurchmischter Reaktor, Kaskade, SBR) unter gleichen Ausgangsbedingungen parallel betrieben. Hierbei wurde der Einfluss des Reaktortyps auf die Prozesse CSB-Elimination, Nitrifikation, Denitrifikation sowie biologische P-Elimination unter Betriebsbedingungen untersucht. (orig.)

  5. Microbiological studies in enhanced sewage sludge degradation through cell membrane break-up; Mikrobiologische Untersuchungen zum verbesserten Klaerschlammabbau durch Zellaufschluss. Mechanische und thermische Behandlung von Schlaemmen

    Energy Technology Data Exchange (ETDEWEB)

    Battenberg, S.; Naeveke, R. [Gesellschaft fuer Biotechnologische Forschung mbH, Braunschweig (Germany). Bereich Mikrobiologie

    1999-07-01

    Mechanical disintegration breaks up the flake structure of excess sludge and solubilizes organic constituents. Bacterial cells are rendered soluble. Thermal conditioning of excess sludge, too, can release sludge constituents. This makes for enhanced and accelerated hydrolysis of polymeric sludge constituents in subsequent anaerobic processing. The yield of useful biogas is increased. (orig.) [German] Durch die mechanische Desintegration von Ueberschussschlamm wird die Flockenstruktur zerschlagen und organische Inhaltsstoffe werden in Loesung gebracht. Bakterienzellen werden aufgeschlossen. Auch durch eine thermische Behandlung von Ueberschussschlamm koennen Schlamminhaltsstoffe freigesetzt werden. Dadurch wird bei einer anschliessenden anaeroben Behandlung die Hydrolyse der polymeren Schlamminhaltsstoffe gefoerdert und beschleunigt. Die Ausbeute an verwertbarem Biogas wird gesteigert. (orig.)

  6. Experimental investigations of tyre-road interactions during braking; Experimentelle Untersuchungen zur Interaktion zwischen Pkw-Reifen und Fahrbahn beim Bremsen

    Energy Technology Data Exchange (ETDEWEB)

    Chunyang Xie

    2002-07-01

    Tyre-road interactions during braking were investigated experimentally. The measurements were found to be highly accurate. In the first stage, the braking force is enhanced by elastic deformation of the profile elements at the onset of tyre contact. In case of high slip or a high sliding velocity, frictional vibration of the tyre section in contact with the road may occur, which is enhanced by the reduction of braking pressure in case of automatic brake control. The eigenfreequency of the frictional vibration also depends on the road texture and friction coefficient. The measured movements of the profile elements provide a good explanation of the causes of tyre noise. [German] In der Dissertation wurde die Interaktion Reifen/Fahrbahn beim Bremsen experimentell untersucht. Die Messungen zeigen, dass die mit dem neuen Reifensensor erfassten Profilelementverformungen den Reibungszustand zwischen Reifen und Fahrbahn gut widerspiegeln. Die Bremskraft wird zunaechst durch die elastischen Verformungen der Profilelemente am Anfang des Reifenlatsches wesentlich aufgebaut. Beim hohen Bremsschlupf bzw. der hohen Gleitgeschwindigkeit kann die Reibungsschwingung des Laufstreifens des Reifens auftreten. Der Bremsdruckabbau der ABS-Regelung beguenstigt die Entstehung dieser Reibungsschwingung. Die Eigenfrequenz der Reibungsschwingung ist auch abhaengig von der Fahrbahntextur und dem Reibwert. Die aus den Signalen des Profilrillensensors berechneten Beschleunigungen der Profilelemente zeigen deutlich den Aufschlag beim Einlauf des Reifens und das Ausschnappen beim Auslauf. Durch die gemessenen Bewegungen der Profilelemente laesst sich die Entstehung des Reifengeraeusches in einigen Frequenzbereichen gut erklaeren. (orig.)

  7. {sup 2}H-NMR study of amorphous and crystalline high pressure ice phases; {sup 2}H-NMR-Untersuchungen an amorphen und kristallinen Hochdruckeisphasen

    Energy Technology Data Exchange (ETDEWEB)

    Scheuermann, Marco

    2008-10-27

    The objective of this work was to produce different high pressure ice phases and measure them at ambient pressure. Temperature dependent relaxation measurements were performed for the first time. All three amorphous ices differ significantly in their temperature dependent T1-values. Applying a heating rate of 1 K/h the transformation of HDA into LDA takes place at a temperature of 105 K. By contrast, warming up VHDA to temperatures above 105 K leads to a relaxed form with relaxation times that resemble the values of HDA. This modification eventually transforms into LDA at 115 K. Our data analysis indicates that this intermediate state is not an inhomogeneous mixture of VHDA and LDA, suggesting that the VHDA/LDA transition is not of a simple first order type. In ice II relaxation measurements and stimulated echo experiments were performed for the first time. The observed temperature of the transition from ice II to cubic ice, 145 K, is consistent with literature data, considering our heating rate of about 1 K/day. The relaxation curves show a bimodal evolution. This is not due to structural heterogeneities, because additional X-ray diffraction measurements exclude a contamination of our samples with other ice phases. The slow relaxing component displays no temperature dependence. The time constant of the fast component reveals Arrhenius-like behaviour, although the activation energy is only 2 kJ/mol. Such a small value can not be attributed to reorientation dynamics as the origin of relaxation in ice II. The decay of the stimulated echo is only about one order of magnitude faster than the decay due to spin-lattice relaxation. The resulting correlation time is temperature independent. Hence, the loss of correlation can not be due to molecular dynamics. But it could stem from spin diffusion, which is known to induce frequency shifts of individual spins in deuteron systems. This interpretation is supported by the analysis of the geometry of the underlying process. The geometry exhibits no small angle jumps as would be expected if the stimulated echo decay originates from structural reorientation dynamics. No rotation dynamics with time scales from 1e-5 s to about 100 s were observed in ice II in its stability region at ambient pressure. In fact, there are strong indications for a spatially restricted occurence of spin diffusion. (orig.)

  8. Studies on the reactive pulsed-magnetron sputtering of ITO from metallic targets; Untersuchungen zum reaktiven Pulsmagnetronsputtern von ITO von metallischen Targets

    Energy Technology Data Exchange (ETDEWEB)

    Gnehr, W.M.

    2006-06-15

    The thesis deals with a reactive sputter process for the deposition of ITO- films. In contrast to the usual technique, the sputter targets consists of indium-tin-alloy instead of ceramic ITO. All experiments were conducted on an inline coater with 600 mm target-width. The process is stabilized by a control loop based on optical emission detection. The experiments prove, that this control loop guarantees a long term stability of the outcomes of the coating process.Process parameters, that are crucial for the optical and electrical properties of the deposited thin films are identified and studied. Among them are the flow of oxygen and the substrate temperature but also less obvious parameters such as the distance between target and substrate.Througout the work the focus is on the film deposition with pulsed plasmas. Novel bipolar DC pulse- and pulse package generators are employed for the deposition.In order to shed some light onto the influence of certain pulse parameters on the outcome of a particular coating process, a Monte-Carlo-Simulation of the particle flow in pulsed plasmas is developed. This simulation yields the distribution of particles and their respective energies on deliberately placed planes in the process chamber. Particles under investigation are both sputtered species and neutral sputter gas atoms reflected at the target. The results of this simulation provide an explanation for the influence of certain pulse parameters on the outcome of the coating process. The further investigations deal with the influence of the construction of the process chamber on the coating process. For this purpose, locally resolved optical spectra are recorded. In order to analyse these spectra, a novel connected fit algorithm is developed.This algorithm yields the distribution of certain fitparameters on the substrate. Provided the most complex of the discussed parametrizations of the dielectric function are used, these can be crucial properties such as the carrier density or the density of ionised defects. The kernel of this method is an algorithm, that minimizes the difference between simulated and locally measured spectra while considering the film properties in neighboring areas.This technique is then used to compare different designs of sputter chambers and to identify their respective deficits. (orig.)

  9. Investigations in the upper load range of stratified operation with injection pressures up to 1000 bar; Untersuchungen im oberen Lastbereich des Schichtbetriebes bei Einspritzdruecken bis 1000 bar

    Energy Technology Data Exchange (ETDEWEB)

    Buri, Stefan; Busch, Steve; Kubach, Heiko; Spicher, Ulrich [Karlsruhe Univ. (DE). Inst. fuer Kolbenmaschinen (IFKM)

    2010-07-01

    This paper presents the results of recent research that has been performed on a single-cylinder spray-guided DISI engine at the Institut fuer Kolbenmaschinen. A production multihole injector is used as a baseline and compared with a specially adapted injector at higher injection pressures. Injection pressures of up to 1000 bar are utilized to investigate the combustion and emissions characteristics at the stability limit of stratified combustion. With the modified injector, measurements with the two-color method are applied to analyze this operating condition in terms of soot formation. Included are results for a spark timing variation with 1000 bar injection pressure, an injection pressure variation with constant spark timing, and fuel consumption-optimized engine operating parameters in order to analyze realistic operating points. The benefits of injecting fuel at higher pressures are described, as are the limitations of the experimental setup. (orig.)

  10. Studies on the beam dynamics at the harmonic double-side microtron of MAMI-C; Untersuchungen zur Strahldynamik am Harmonischen Doppelseitigen Mikrotron von MAMI-C

    Energy Technology Data Exchange (ETDEWEB)

    Dehn, Marco

    2013-10-28

    The Institut fuer Kernphysik at Mainz University operates a worldwide unique accelerator for experiments in nuclear and particle physics since 1990. The Mainzer Mikrotron (MAMI-B) uses three cascaded racetrack microtrons (RTM) with RF linacs operating at 2.45 GHz to accelerate a continuous electron beam of up to 100 μA to 855 MeV. In 1999 the realisation of the fourth stage - the Harmonic Double Sided Microtron (HDSM, MAMI-C) - reaching a maximum beam energy of 1.5 GeV was started. During the development some courageous decisions were necessary. For example the bending magnets with their field gradient and corresponding beam optical properties have large influence on the longitudinal beam dynamics. That in turn requires harmonic operation with two RF linacs operating at 4.9 GHz and 2.45 GHz. Many parameters of the machine settings (like RF voltage or phase) have great impact on the acceleration process but not always they are easily to quantify in physical units. Concerning the RTMs with their comparatively simple and well defined beam dynamics that is rather unproblematic. However, in the HDSM the larger number of parameters requires a more precise knowledge of these quantities. Therefore it is necessary to develop dedicated methods of beam diagnostics to check the important machine parameters against their design values. All these methods are not free of systematic errors or insufficiencies and thus fitting a model of the machine to measured data does not always yield unambiguous results. To overcome this problem a special kind of tomography is used to scan the longitudinal phase space resulting in acceptance measurements. The large amount of data with systematic variations now yields a better significance of the fitted parameters. The results of these investigations demonstrate that the accelerator as an entity acts as predicted and shows that many different configurations can be used to operate the HDSM. However, for most situations one single configuration is established to improve the reproducibility of e.g. the beam energy or the spin polarisation angle at the experimental areas. Some of the resulting findings were automated to aid the operators of MAMI by means of additional diagnostic tools. These tools now guarantee a more reliable and systematical approach while operating the HDSM routinely.

  11. Comparative measurements of heat and moisture transfer in different wood-based building elements; Vergleichende Untersuchungen zum Feuchte- und Waermeverhalten unterschiedlicher Holzbauelemente

    Energy Technology Data Exchange (ETDEWEB)

    Joscak, Matus; Sonderegger, Walter; Niemz, Peter [ETH Zuerich, Institut fuer Baustoffe, Arbeitsgruppe Holzphysik, Zuerich (Switzerland); Holm, Andreas; Krus, Martin; Grosskinsky, Theo; Lengsfeld, Kristin [Fraunhofer-Institut fuer Bauphysik, Valley (Germany); Grunewald, John; Plagge, Rudolf [Technische Universitaet Dresden, Institut fuer Bauklimatik, Dresden (Germany)

    2011-10-15

    At the campus of the Fraunhofer Institute for Building Physics (IBP) in Holzkirchen/Germany comparative measurements of heat and moisture transfer in five different wood-based building elements were carried out (wood construction with slotted wood elements, solid wood construction connected with wooden dowels, new developed soft fibreboard brick construction, solid wood panel construction, wood frame construction with stacked wood elements). The elements were installed on the west side of the test building and examined during one year. The following physical quantities were measured: indoor climate, external and internal surface temperatures, temperatures in the boundary layers, heat flux through the internal surface of the constructions, relative humidity and moisture content. Furthermore, the measured data were used for validation of the simulation softwares WUFI {sup registered} Pro and Delphin. During winter, the measured U-values (from unsteady-state values) were compared with steady-state calculated U-values. Both values were well coincident. Moreover, the simulation results achieved good agreement by using the thermal conductivity values measured at ETH Zurich, which were considerably lower than the standard values. Although, the four elements had been covered with a non rear-ventilated facade, no critical values of relative humidity were measured inside the constructions. The simulation results of relative humidity have partly shown large deviations from measured data by both simulation softwares.

  12. Studies on ternary and quaternary copper, lithium and silver sulfides with a diamond structure; Untersuchungen an ternaeren und quaternaeren Kupfer-, Lithium-, und Silbersulfiden mit Diamantstruktur

    Energy Technology Data Exchange (ETDEWEB)

    Greil, Sebastian

    2015-04-09

    Within this work new attempts have been done to prepare unknown compounds in the field of quaternary tetrahedral compounds. Therefore it was tried to synthesize compounds of the composition A{sup I}{sub 2}M{sup II}M{sup IV}S{sub 4} with A = Ag, Li, M{sup II} = Fe, Co, Mn, Hg, Cd, Zn, Pb, MIV = Si, Ge, Sn, which are not known in the literature so far. For these compositions the known copper compounds were used as a model. Using this route, the new compounds Ag{sub 2}MnSnS{sub 4}, Ag{sub 2}FeGeS{sub 4}, Li{sub 2}MnSnS{sub 4} and Li{sub 2}FeSnS{sub 4} were synthesized. All of the mentioned compounds except Ag{sub 2}FeGeS{sub 4}, that crystallizes tetragonal, crystallize in the wurtzite-type. The predicted anti-ferromagnetism for Ag{sub 2}MnSnS{sub 4} mentioned in the literature could not be confirmed. Furthermore it was attempted to synthesize new compounds containing titanium, zirconium and hafnium as tetravalent cation that resulted in the compound Cu{sub 2}ZrS{sub 3} which was not known in the literature before. Additionally, the compounds Cu{sub 10}Cd{sub 2}As{sub 4}S{sub 13} and Cu{sub 10}Mn{sub 2}As{sub 4}S{sub 13} were prepared, which could be derived from Cu{sub 12}As{sub 4}S{sub 13}.

  13. Investigations of the cerebral blood flow by means of nuclear medicine in polycythemia vera rubra. Untersuchungen des zerebralen Blutflusses bei Polyzythaemia vera rubra mit nuklearmedizinischen Methoden

    Energy Technology Data Exchange (ETDEWEB)

    Franke, W.G. (Medizinische Akademie Dresden, Klinik und Poliklinik fuer Nuklearmedizin (Germany)); Unger, L. (Medizinische Akademie Dresden, Klinik und Poliklinik fuer Psychiatrie und Neurologie (Germany)); Mueller, J. (Medizinische Akademie Dresden, Klinik und Poliklinik fuer Psychiatrie und Neurologie (Germany))

    1993-04-01

    P.v. represents a ''clinical model'' of diagnostic radionuclide application to evaluate the total and regional perfusion of brain. 107 polycythemians treated by or provided for radiophosphorus were studied by neurologic methods as EEG e.g. and with XCT if necessary. These studies were accomplished repeatedly in 62% of the surveyed patients. We found disturbed perfusion in brain: 32, diminuation of blood flow in vertebral-basilar region: 8, polyneuropathies: 27, psychic abnormalities: 60. Therapeutic effects became ascertained in 34% of hemipareses. The majority of polycythemic patients let recognize a regression of subjective complaints. The diagnostic informations obtained by radionuclide methods were compared to clinical and neurologic results as mentioned above. A good correlation could observed from radionuclide angiography, [sup 133]Xe-studies of total and regional cerebral perfusion and HMPAO-SPECT to neurologic and radiological findings. 66% of studied patients showed abnormal radioactivity distribution at static scintigrams. Disturbances of cerebral perfusion were seen in 20 from 26 patients if radionuclide angiography was used. Especially the inflow to cerebral vessels was found retarded by this method. Even in 3 neurologically inconspicuous persons the cerebral perfusion was restricted. Only 5 patients without signs of decreased flow could be seen. In 9 of 10 cases studied using [sup 133]Xenon referred to diminuation of cerebral perfusion. Both dynamic methods showed changes in perfusion depending from time course. Numerous localized defects of vascularization were detected by SPECT in some corresponding with neurologic symptoms in other patients differing from these ones. (orig./MG)

  14. Investigations of power supply and propulsion for a lighter-than-air high altitude platform; Untersuchungen zu Energieversorgung und Antrieb einer Leichter-als-Luft-Hoehenplattform

    Energy Technology Data Exchange (ETDEWEB)

    Kotulla, Michael

    2008-06-20

    High altitude platforms are one alternative to replace ground-bounded relay stations for telecommunication purposes. Already in service are such concepts like tethered balloons or stratospheric airplanes in the field of surveillance, for example to patrol borders. Disadvantages of those concepts are either to disturb the airspace by the wire or to be constricted in terms of mission endurance. Thus, untethered high altitude airships with long mission endurance are currently in the focus of research. One basic requirement for telecommunication platforms is to remain in a fix positioning frame over ground. Therefore wind speed has to be compensated by the propulsion system of the airship. The scope of this work is to investigate the drive and power generation system of a multiple-unit airship. The reduced rigidness of the hull and the resulting lower structural weight yield a higher load capacity and hence increase the mission length by larger fuel reserves. The drawbacks of this configuration are higher stabilization demands and distributed drive units. This leads to a rather complex propulsion system for which a real-time simulation model is provided. Besides electrical driven propellers, the system involves gas turbines and generators to work as power plants, back-up batteries, power-electronics and distribution. Those power plants reflect the state of the art and are thus rather conservative compared to other propulsion concepts for high altitude platforms. The advantage of splitting up the power generation into multiple units is to run only as much power plants as currently required and for this reason, to save energy. In addition, an involvement of the back-up battery reduces the ineffective operation of a power plant in part load. Another reason to employ a battery system is that highly dynamic power requirements, caused for example by a gust of wind, cannot be covered immediately by the power plants. The maximum discharge power of the back-up battery is at level with the maximum power output of one power plant. It is available at any time. As a result, the dynamic properties of the system can be plainly improved. The simulation model of the propulsion system is built-on independent modules. Single component models may easily be modified or exchanged by enhanced component models. Thus, single component models are equipped with their own control devices. Beyond, the overall propulsion system controls comprise routines to decide whether a single power plant is operated or not. This decision depends on the status of charge of the back-up battery. The lack of knowledge regarding the dynamic of stratospheric wind speed turns out to be of great disadvantage. Most of the control routines that decide a start-up or shut-down of a power plant require a short-term wind forecast. With a time resolution of currently six hours, available wind data doesn't contain this information. Here, a probably high wind dynamic is taken into account. The involvement of the back-up battery is thus mainly limited to cover dynamic power requirements. The potential to optimize the power plant efficiency is thus not yet fully exploited. Achievable mission endurance at a given amount of fuel is a result of seasonal wind speed. Over middle Europe, wind speed is at a minimum during summer and at a maximum during the winter months. At summer, the mission endurance that has been achieved by simulations lays around nine days. This may be prolonged by a greater use of the back-up battery. During winter, the mission endurance is limited to five to seven days. All stationary power requirements can be covered by the propulsion system. For high propulsion efficiencies big propeller rotor diameters have been implemented. The resulting mass inertia is impeding acceleration and thus delaying the coverage of dynamic thrust requirements. Big diameters combined with little stationary power requirements are only one example for the challenges in the development of high altitude applications. With the given simulation model one possible solution for the drive and power generation system of a lighter-than-air high altitude platform has been worked out. (orig.)

  15. Rückstandsanalytische Untersuchungen für eine aktualisierte Bewertung des Einsatzes hormonal wirksamer Leistungsförderer in der Tiermast

    OpenAIRE

    Lange, Iris Gudrun

    2005-01-01

    Bei der Anwendung hormonal wirksamer Leistungsförderer in der Tiermast in Form von Implantationspräparaten ist die Einhaltung der "Guten Veterinärpraxis" unabdingbar. Gelangen Implantationsstellen in die Nahrungskette, können ganze Chargen von Fleischprodukten kontaminiert werden. Das höchste Gefährdungspotential geht dabei von Trenbolonacetatpräparaten aus, gefolgt von Östradiol bzw. Östradiolbenzoat, Testosteronpropionat und Progesteron. Eine Evaluierung von Zeranol war diesbezüglich im Rah...

  16. Untersuchungen über Auswirkungen unterschiedlicher Abdeckungen (Vlies/Folie) auf Wachstum und Ertrag von Frühkartoffeln im ökologischen Landbau

    OpenAIRE

    Hüsing, Bianka; Trautz, Dieter; Schliephake, Ulrike; Heuer, Ragnar

    2007-01-01

    Different coverings (fleece, punched mulching film, thermal foil (Wepelen® Climatec) for early potatoes in ecological cultivation where compared in order to show their advantages and/or disadvantages concerning to crop and profit. As a result a increase of crop and profit could be appointed by all coverings (except fleece 2006). A financial success depends on the annual climate conditions and potato price.

  17. Dose-response relationships determined in growing rats for various platinum compounds administered with the food. Untersuchungen zu Dosis-Wirkungsbeziehungen verschiedener alimentaer zugefuehrter Platinverbindungen bei wachsenden Ratten

    Energy Technology Data Exchange (ETDEWEB)

    Bader, R.

    1991-02-08

    Forming part of a research project entitled 'Emissions of Precious Metals', this study had the aim to describe dose-related responses that occur in growing rats following administration of platinum with the food. The oral intake of diets containing up to to 50 mg platinum/kg food had no detectable influence on the food consumption of the animals, nor were there any deviations from the normal growth curves that could be related to the addition of platinum. Comparisons with the control group pointed to a decline in erythrocytes from 5.88 {+-} 0.55 x 10{sup 6}/{mu}l to 5.11 {+-} 0.50 x 10{sup 6}/{mu}l following administration of 50 ppm PtCl{sub 4} over a period of four weeks. There were no other changes in hematological parameters that attained statistical significance. The treatment group receiving platinum amounts of 50 mg/kg with the diet showed a plasma creatinine value of 1.45 {+-} 0.19 {mu}g/dl, which significantly (p < 0.05) exceeded that of the control group, where creatinine levels remained at 0.70 {+-} 0.50 {mu}g/dl. This leads to the conclusion that the possibility of renal impairment after high oral doses of PtCl{sub 4} is not very remote. (orig./VT).

  18. Effective half-life of sup 131 I during treatment of autonomous thyroid disease. Untersuchungen zur effektiven Halbwertszeit des sup 131 J bei der Radiojodbehandlung der Schilddruesenautonomie

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, B.; Bares, R.; Buell, U. (Technische Hochschule Aachen (Germany, F.R.). Klinik fuer Nuklearmedizin)

    1991-06-01

    In order to compute effective half-life of {sup 131}I after application of therapeutic doses (T{sub eff}), the time course of whole-body radioactivity was evaluated retrospectively in 115 patients with benign thyroid diseases (multinodular autonomous adenoma, solitary autonomous adenoma or Graves' disease). Because of a large overlap of T{sub eff} in the various diseases analyzed, courses of all patients who did (group Ts, 24 cases) or did not (group kTs, 91 cases) receive antithyroid drugs during therapy were summarized. In group Ts a mean T{sub eff} of 5.0+-0.9 d was found which was significantly (p<0.01) lower than the mean T{sub eff} of 6.3+-0.9 d in group kTs. We believe that the mean T{sub eff} is a practical alternative in radioiodine dosimetry if an exact determination of T{sub eff} cannot be performed because of shortage of time. (orig.).

  19. Automated detection and volumetric segmentation of the spleen in CT scans; Automatische Detektion und volumetrische Segmentierung der Milz in CT-Untersuchungen

    Energy Technology Data Exchange (ETDEWEB)

    Hammon, M.; Dankerl, P.; Janka, R.; Uder, M.; Cavallaro, A. [Universitaetsklinikum Erlangen (Germany). Radiologisches Inst.; Kramer, M.; Seifert, S.; Tsymbal, A.; Costa, M.J. [Siemens AG, Erlangen (Germany). Corporate Technology

    2012-08-15

    To introduce automated detection and volumetric segmentation of the spleen in spiral CT scans with the THESEUS-MEDICO software. The consistency between automated volumetry (aV), estimated volume determination (eV) and manual volume segmentation (mV) was evaluated. Retrospective evaluation of the CAD system based on methods like ''marginal space learning'' and ''boosting algorithms''. 3 consecutive spiral CT scans (thoraco-abdominal; portal-venous contrast agent phase; 1 or 5 mm slice thickness) of 15 consecutive lymphoma patients were included. The eV: 30 cm{sup 3} + 0.58 (width x length x thickness of the spleen) and the mV as the reference standard were determined by an experienced radiologist. The aV could be performed in all CT scans within 15.2 ({+-} 2.4) seconds. The average splenic volume measured by aV was 268.21 {+-} 114.67 cm{sup 3} compared to 281.58 {+-} 130.21 cm{sup 3} in mV and 268.93 {+-} 104.60 cm{sup 3} in eV. The correlation coefficient was 0.99 (coefficient of determination (R{sup 2}) = 0.98) for aV and mV, 0.91 (R{sup 2} = 0.83) for mV and eV and 0.91 (R{sup 2} = 0.82) for aV and eV. There was an almost perfect correlation of the changes in splenic volume measured with the new aV and mV (0.92; R{sup 2} = 0.84), mV and eV (0.95; R{sup 2} = 0.91) and aV and eV (0.83; R{sup 2} = 0.69) between two time points. The automated detection and volumetric segmentation software rapidly provides an accurate measurement of the splenic volume in CT scans. Knowledge about splenic volume and its change between two examinations provides valuable clinical information without effort for the radiologist. (orig.)

  20. Untersuchungen zur Herstellung dünner strukturierter Späne aus Holz durch Fräsen mit kleinen Einstellwinkeln. Teil 2

    OpenAIRE

    Heisel, Uwe; Tröger, Johannes

    1993-01-01

    Gegenwärtig ist auf vielen Wissensgebieten eine intensive Forschungstätigkeit mit den Zielen der Schaffung umweltfreundlicher Produktionstechnologien und Herstellung entsprechender Erzeugnisse im Gang wie beispielsweise zur Einsparung von Primärenergie im Produktionsprozeß, Verminderung der CO2-Ernission, Herstellung umweltgerechter Baustoffe, verstärkten Verwendung unbedenklicher natürlicher Isolationswerkstoffe, Herstellung umweltfreundlich entsorgbarer bzw. kompostierbarer Verpackungswerks...

  1. Untersuchungen zur Herstellung dünner strukturierter Späne aus Holz durch Fräsen mit kleinen Einstellwinkeln. Teil 1

    OpenAIRE

    Heisel, Uwe; Tröger, Johannes

    1993-01-01

    Gegenwärtig ist auf vielen Wissensgebieten eine intensive Forschungstätigkeit mit den Zielen der Schaffung umweltfreundlicher Produktionstechnologien und Herstellung entsprechender Erzeugnisse im Gang, wie beispielsweise zur Einsparung von Primärenergie im Produktionsprozeß, Verminderung der CO2-Emission, Herstellung umweltgerechter Baustoffe, verstärkten Verwendung unbedenklicher natürlicher Isolationswerkstoffe, Herstellung umweltfreundlich entsorgbarer bzw. kompostierbarer Verpackungswerks...

  2. Investigations regarding the mass budget in the propagation of a passive admixture from a line source; Untersuchungen zur Stoffbilanz bei der Ausbreitung einer passiven Beimengung aus einer Linienquelle

    Energy Technology Data Exchange (ETDEWEB)

    Wenzel, A. [Brandenburgische Technische Univ. Cottbus (Germany). Inst. fuer Boden-, Luft- und Gewaesserschutz

    1998-01-01

    Under stationary conditions, passive admixtures are transported by advection and by vertical as well as horizontal turbulent diffusion. The importance of individual contributions for the exchange of passive admixtures emanating from a straight line source with a constant source strength under neutral stratification conditions is discussed. For this purpose, all terms of the mass budget for a control volume around a straight line source are calculated using a stochastic Lagrange model (LS), whose properties are discussed. As a test for the LS model, the vertical and horizontal mass flows in the soil layer are simulated and compared with SANA data. The mass flows calculated for the propagation of a passive admixture from a line source are evaluated regarding their share of the mass budget. (orig.) [Deutsch] Unter stationaeren Bedingungen erfolgt der Transport von passiven Beimengungen durch Advektion sowie vertikale und horizontale turbulente Diffusion. Die Bedeutung der einzelnen Beitraege fuer den Austausch von passiven Beimengungen, die von einer geraden Linienquelle mit konstanter Quellstaerke unter neutralen Schichtungsbedingungen ausgehen, wird diskutiert. Dazu werden mit einem Lagrangeschen stochastischen (LS) Modell, dessen Eigenschaften besprochen werden, alle Terme der Stoffbilanz fuer ein Kontrollvolumen um eine gerade Linienquelle berechnet. Als Test fuer das LS-Modell werden die vertikalen und die horizontalen Stofffluesse in der Bodenschicht simuliert und mit SANA-Daten verglichen. Die fuer die Ausbreitung einer passiven Beimengung von einer Linienquelle berechneten Massenfluesse, werden hinsichtlich ihres Anteils an der Stoffbilanz ausgewertet. (orig.)

  3. Studies on the hazard potential of noble metal emissions from catalytic converters; Untersuchungen zur Frage des Gefaehrdungspotentials von katalysatorbuertigen Edelmetallemissionen (VPT 05)

    Energy Technology Data Exchange (ETDEWEB)

    Artelt, S. [Fraunhofer-Institut fuer Toxikologie und Aerosolforschung, Hannover (Germany)

    1997-12-31

    Plants were exposed to engine exhaust fumes from engine test stands in order to estimate the probable level of platinum deposition near roads. [Deutsch] Zur Abschaetzung der zu erwarteten Platindeposition in der Naehe von Strassen wurden Pflanzen mit Motorabgasen, die aus Motorstandexperimenten gewonnen wurden, beaufschlagt. (orig.)

  4. Studies in uptake and turnover of tritiated water vapour (HTO) by vegetables. Untersuchungen zur Aufnahme und zum Umsatz von tritiiertem Wasserdampf (HTO) in Gemuesepflanzen

    Energy Technology Data Exchange (ETDEWEB)

    Roller, M.

    1989-02-01

    The aerial parts of vegetables were exposed to tritiated water vapour for up to three days in a plant growth chamber. The species used were Raphanus sativus L., Phaseolus vulgaris K. and Daucus carota L. (red radish, bean and carrot). The increase of specific activity of tissue free water as collected by freeze drying which was observed in the aerial parts of plants is explained by direct uptake of tritiated water vapour by the exposed part of the plant. It shows different characteristics for the several organs. No translocation of water from the laminae into other parts of the plant was observed. After combustion of dry matter tritium activity was detectable in the oxidation water for all parts of the plants. Kinetics of the specific activity of organically bound tritium in leaves can be described by a single curve. The lower - steep - part of the curve is increasing approximately with the uptake rate of HTO; this is explained by reversible binding of tritium by isotopic exchange reactions. The upper - flat - part of the curve represents tritium bound by light dependent reducing reactions of photosynthesis; it is increasing with a rate similar to the growth rate of leaves. (orig./KG).

  5. Investigations on uranium sorption on bentonite and montmorillonite, respectively, and uranium in environmental samples; Untersuchungen zur Uransorption an Bentonit bzw. Montmorillonit sowie von Uran in Umweltproben

    Energy Technology Data Exchange (ETDEWEB)

    Azeroual, Mohamed

    2010-09-22

    The geotechnical barrier is an important component of a geological repository and consists of compacted bentonite surrounding radioactive waste containers. Its most important functions are, to retard the radionuclide migration into the biosphere and to prevent groundwater contact with containers. lt is therefore of central importance to investigate the bentonite material on its capacity to sorb radionuclides under near-natural chemical and physical conditions. The purpose of this work was to study the adsorption of uranium(VI) on bentonit and on montmorillonite-standards at high uranium concentrations. Thereby, a special account was given to the calcium-uranyl-carbonate complexation, which leads to the formation of very stable and mobile uncharged Ca{sub 2}UO{sub 2}(CO{sub 3}){sub 3} complex. Results of batch experiments showed that the dicalcium-uranyl-tricarbonate complexation lowers the uranium(VI) sorption on natural clay (bentonite) by a factor of up to 3. After 21 days of contact time, about 40 % and 20 % of the initial uranium(VI)concentration were sorbed on Na-bentonite and ea-bentonite, respectively, from a solution with Ca{sub 2}UO{sub 2}(CO{sub 3}){sub 3} dominating the uranium(VI) speciation. On the contrary, about 55 % of the initial uranium(VI)-concentration were sorbed on thes clays from the solution, in which (UO{sub 2}){sub 2}CO{sub 3}(OH){sub 3}{sup -} complex dominated the uranium(VI) speciation. Thus uranium(VI) sorption is more strongly influenced by the solution composition than by bentonite type. Na-bentonite should be used instead of ea-bentonite as a geotechnical barrier, since calcium-uranyl-carbonate complexation may be a realistic scenario. Further SEM-EDX and HREM-EDX studies showed that uranium(VI) sorption occurred predominantly on montmorillonite, which is the main component of bentonite. Uranium(VI) sorption on bentonite's accessory Minerals (pyrite, calcite, mica, and feldspar) was not observed. Investigation of uranium(VI) sorption on four montmorillonite-standard, which are distinguished by the cationic composition of the octahedral sheet, provided further evidence on the mechanism of uranium(VI) sorption on montmorillonit. The uranium(VI) sorption was found to be controlled by the cationic composition of the octahedral sheet and by the dissolution rate of montmorillonite. Higher Mg contents in the octahedral sheet enhance the dissolution kinetics of Montmorillonite and thus lower uranium(VI) sorption with time and vice versa. In addition to Al and Fe octahedron, Mg octahedron contributes to the sorption of uranium(VI) (here 20 up to 50 % depending on Mg content in Montmorillonite). These observations allowed to propose a model for the mechanism of uranium(VI) sorption on the edge surface of montmorillonite. At lower octahedral Mg contents (here SWy- and STx-montmorillonites), at which the distance between Mg octahedra becomes larger, uranium(VI) binds monodentately to AlAl-OH, AlFe-OH, AlMg-OH, FeFe-OH, and FeMg-OH pairs and the Mg octahedra contribute up to approximately 20 % to the sorption of uranium(VI). At high Mg contents in the octahedral sheet, where the distance between Mg octahedra becomes small and MgMg-OH pairs can occur, uranium(VI) forms monodentate surface complexes with AlAl-OH, AlFe-OH, AlMg-OH, FeFe-OH, FeMg-OH, and MgMg-OH pairs and the Mg octahedra can even stronger contribute to uranium(VI) sorption (up to about 50 %). The second focus of this work concerned the environmental analytics of uranium. In this regard, extensive investigations of environmental samples from tailings disposal sites near Mailuu-Suu city (Kyrgyzstan) were carried out. Previous radiological examinations in Mailuu-Suu showed that uranium can migrate from tailings as a result of rain events to the ground water and river water and eventually to the foods [Vandenhove et al., 2006]. Therefore, it was very important to investigate, uranium speciation in water samples and the processes which controlling uranium releases from tailings into the aquatic system. The results showed that uranium(VI) speciation in water samples is controlled by pH as well as bicarbonate and calcium concentrations and is dominated by the very stable aquatic complexes Ca{sub 2}UO{sub 2}(CO{sub 3}){sub 3}, (UO{sub 2}){sub 2}CO{sub 3}(OH){sub 3}{sup -} and UO{sub 2}(CO{sub 3}){sub 3}{sup 4-}. Influences of humic substances or phosphate ligands on uranium(VI) complexation were not detected. Uranium association with aquatic colloids in the studied samples as found to be negligible. With the help of a combination of the AREM-EDX method and batch experiments, uraninite (UO{sub 2}) and brannerite (UTi{sub 2}O{sub 6}) could be identified with an occurrence frequency of about 67 % and 33 %, respectively. This combination allowed the conclusion that uranium release from tailing materials is controlled by the dissolution of uraninite, which itself is governed by the dissolution of calcite. Furthermore, a mobilisation of uraninite colloids smaller than 200 nm from tailing material into the used model solutions was observed.

  6. Studies on the controlled growth of InAs nanostructures on scission surfaces; Untersuchungen zum kontrollierten Wachstum von InAs-Nanostrukturen auf Spaltflaechen

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, J.

    2006-01-15

    The aim of this thesis was the controlled alignment of self-assembled InAs nano-structures on a {l_brace}110{r_brace}-oriented surface. The surface is prestructured with the atomic precision offered by molecular beam epitaxy, using the cleaved edge overgrowth-technique. On all samples grown within this work, the epitaxial template in the first growth step was deposited on a (001)GaAs substrate, while the InAs-layer forming the nanostructures during the second growth step was grown on cleaved {l_brace}110{r_brace}-GaAs surfaces. Atomic Force Microscopy (AFM) investigations demonstrate the formation of quantum dot (QD)-like nanostructures on top of the AlAs-stripes. X-ray diffraction measurements on large arrays of aligned quantum dots demonstrate that the quantum dots are formed of pure InAs. First investigations on the optical properties of these nanostructures were done using microphotoluminescence-spectroscopy with both high spatial and spectral resolution. (orig.)

  7. Power to gas. Investigations in the context of the DVGW innovation offensive for energy storage; Power to Gas. Untersuchungen im Rahmen der DVGW-Innovationsoffensive zur Energiespeicherung

    Energy Technology Data Exchange (ETDEWEB)

    Mueller-Syring, Gert; Henel, Marco [DBI Gas- und Umwelttechnik GmbH, Leipzig (Germany); Rasmusson, Hans [DVGW Deutscher Verein des Gas-und Wasserfaches e.V., Bonn (Germany); Mlaker, Herwig [E.ON Ruhrgas AG, Koeln (Germany); Koeppel, Wolfgang [DVGW-Forschungsstelle am Engler-Bunte-Institut, Karlsruhe (Germany); Hoecher, Thomas [Verbundnetz Gas AG (VNG), Leipzig (Germany); Sterner, Michael [Fraunhofer Institut fuer Windenergie und Energiesystemtechnik (IWES), Kassel (Germany)

    2011-04-15

    The gas pipeline network is an efficient, safe, environment-friendly and socially acceptable energy infrastructure. It is suited in principle also for the transport of hydrogen or methane generated from renewable electric power. Utilization of the gas infrastructure and its components thus offers a chance for an ecologically and economically acceptable transition from a fossil power supply structure to a renewable structure and will become an indispensable part of the future power supply system.

  8. Power to gas. Investigations in the context of the DVGW innovation offensive for energy storage; Power to Gas. Untersuchungen im Rahmen der DVGW-Innovationsoffensive zur Energiespeicherung

    Energy Technology Data Exchange (ETDEWEB)

    Mueller-Syring, Gert; Henel, Marco [DBI GUT (Germany); Rasmusson, Hans [DVGW, Bonn (Germany); Mlaker, Herwig [E.ON Ruhrgas AG (Germany); Koeppel, Wolfgang [EBI (Germany); Hoecher, Thomas [VNG AG (Germany); Sterner, Michael; Trost, Tobias [Fraunhofer IWES (Germany)

    2011-07-01

    The natural gas grid is an efficient, safe, environmentally friendly and socially acceptable energy infrastructure. Due to its design in principle it is suitable for the propagation of methane or hydrogen from renewable electric power. The use of gas infrastructure and its components offers the possibility for an ecologically and economically sensible transition from fossil to renewable energy. It is an indispensable part of a future energy system.

  9. Magneto-optical measurements on high-temperature superconductors influenced by AC-fields; Magnetooptische Untersuchungen an Hochtemperatursupraleitern unter Einfluss von Frequenzfeldern

    Energy Technology Data Exchange (ETDEWEB)

    Che' Rose, Simon

    2007-01-15

    In this work magneto-optical measurements on YBa{sub 2}Cu{sub 3}O{sub 7-x} and MgB{sub 2} thin films were done. For YBCO the influence of AC-pulses on the flux and current density of a thin film with transport current was investigated. For MgB{sub 2} the influence of AC-fields on the homogenous and dendritic flux penetration was researched. (orig.)

  10. Investigations on forecast-based operating strategies for solar thermal power plants with integrated storage capacity; Untersuchungen zu vorhersagebasierten Betriebsstrategien fuer solarthermische Kraftwerke mit integrierter Speicherkapazitaet

    Energy Technology Data Exchange (ETDEWEB)

    Wittmann, Michael Karl

    2012-07-01

    This publication describes a method for scheduling the operation of a power plant storage. The purpose of operation scheduling is to determine the economically optimum yield achievable in the course of daily power plant operation. The optimum operation schedule for the storage is determined based on Dynamic Programming Algorithms. Besides its focus on operation scheduling the publication investigates the effects of imperfect weather and price forecasts on electricity production and thus on the operator's economic results. It assesses the current Spanish legislation as well as other incentive scenarios in terms of their impact on operators' feed-in behaviour.

  11. Radiological investigations to improve early diagnosis of industrial inhalation poisoning with delayed effect. Radiologische Untersuchungen zur verbesserten Fruehdiagnose von industriellen Inhalationsvergiftungen mit verzoegertem Wirkungseintritt

    Energy Technology Data Exchange (ETDEWEB)

    Diller, W F

    1976-01-01

    The book presents observations of the course of toxic oedema of the lungs in X-rays of humans and animals after inhalation of phosgene gas, nitrous gases, and teflon smoke. Early symptoms are stressed, and an X-ray monitoring programme is presented. The picture is completed by perfusion scintiscans and findings of light and electron microscopy.

  12. Gas sealing efficiency of cap rocks. Pt. 1: Experimental investigations in pelitic sediment rocks. - Pt. 2: Geochemical investigations on redistribution of volatile hydrocarbons in the overburden of natural gas reservoirs; Gas sealing efficiency of cap rocks. T. 1: Experimentelle Untersuchungen in pelitischen Sedimentgesteinen. - T.2: Geochemische Untersuchungen zur Umverteilung leichtfluechtiger Kohlenwasserstoffe in den Deckschichten von Erdgaslagerstaetten. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Leythaeuser; Konstanty, J.; Pankalla, F.; Schwark, L.; Krooss, B.M.; Ehrlich, R.; Schloemer, S.

    1997-09-01

    New methods and concepts for the assessment of sealing properties of cap rocks above natural gas reservoirs and of the migration behaviour of low molecular-weight hydrocarbons in sedimentary basins were developed and tested. The experimental work comprised the systematic assesment of gas transport parameters on representative samples of pelitic rocks at elevated pressure and temperature conditions, and the characterization of their sealing efficiency as cap rocks overlying hydrocarbon accumulations. Geochemical case histories were carried out to analyse the distribution of low molecular-weight hydrocarbons in the overburden of known natural gas reservoirs in NW Germany. The results were interpreted with respect to the sealing efficiency of individual cap rock lithologies and the type and extent of gas losses. (orig.) [Deutsch] Zur Beurteilung der Abdichtungseigenschaften von Caprocks ueber Gaslagerstaetten und des Migrationsverhaltens niedrigmolekularer Kohlenwasserstoffe in Sedimentbecken wurden neue Methoden und Konzepte entwickelt und angewendet. In experimentellen Arbeiten erfolgte die systematische Bestimmung von Gas-Transportparametern an repraesentativen Proben pelitischer Gesteine unter erhoehten Druck- und Temperaturbedingungen und die Charakterisierung ihrer Abdichtungseffizienz als Deckschicht ueber Kohlenwasserstofflagerstaetten. In geochemischen Fallstudien wurde die Verteilung niedrigmolekularer Kohlenwasserstoffe in den Deckschichten ueber bekannten Erdgaslagerstaetten in NW-Deutschland analysiert und im Hinblick auf die Abdichtungseffizienz einzelner Caprock-Lithologien bzw. Art und Ausmass von Gasverlusten interpretiert. (orig.)

  13. Extending Penning trap mass measurements with SHIPTRAP to the heaviest elements

    International Nuclear Information System (INIS)

    Block, M.; Ackermann, D.; Herfurth, F.; Hofmann, S.; Blaum, K.; Droese, C.; Marx, G.; Schweikhard, L.; Düllmann, Ch. E.; Eibach, M.; Eliseev, S.; Haettner, E.; Plaß, W. R.; Scheidenberger, C.; Heßberger, F. P.; Ramirez, E. Minaya; Nesterenko, D.

    2013-01-01

    Penning-trap mass spectrometry of radionuclides provides accurate mass values and absolute binding energies. Such mass measurements are sensitive indicators of the nuclear structure evolution far away from stability. Recently, direct mass measurements have been extended to the heavy elements nobelium (Z=102) and lawrencium (Z=103) with the Penning-trap mass spectrometer SHIPTRAP. The results probe nuclear shell effects at N=152. New developments will pave the way to access even heavier nuclides.

  14. Towards radiation detected resonance ionization spectroscopy on transfermium elements in a buffer gas cell

    Energy Technology Data Exchange (ETDEWEB)

    Lautenschlaeger, Felix; Walther, Thomas [Institut fuer Angewandte Physik, TU Darmstadt, 64289 Darmstadt (Germany); Laatiaoui, Mustapha; Block, Michael [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Helmholtz-Institut Mainz, 55128 Mainz (Germany); Lauth, Werner; Backe, Hartmut [Institut fuer Kernphysik, JGU Mainz, 55128 Mainz (Germany); Hessberger, Fritz-Peter [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, 64291 Darmstadt (Germany)

    2013-07-01

    The study of the atomic structure of transfermium elements like nobelium (No) and lawrencium (Lr) via Radiation Detected Resonance Ionization Spectroscopy (RADRIS) is one of the most fascinating disciplines of modern atomic physics. It allows the determination of relativistic effects at the heaviest elements and provides a critical test of theoretical predictions. For these transfermium elements no experimental data on atomic level schemes are available at present. First experiments on {sup 254}No were performed in 2007, in which a buffer gas cell with an overall efficiency of 1%. In this experiment the evaporation temperature of nobelium was determined for the first time. To increase the efficiency of the buffer gas cell, off-line measurements have been performed with nat. ytterbium, the chemical homologue of nobelium. Also on-line experiments during a parasitic beam-time in 2012 provided an insight into the critical parameters of our setup. The results of the off-line and on-line measurements are briefly summarized in this talk.

  15. Untersuchung des Einflusses von Modellierungsexpertise und Kultur auf die Qualität und das Verständnis von Geschäftsprozessmodellen : ein Lösungsansatz basierend auf empirischen Untersuchungen

    OpenAIRE

    Költer, Denise

    2018-01-01

    Companies are nowadays confronted with a variety of forces, e. g. liberalization of international markets, fast developments in computer and communications, growing force of globalization and thus with a changing competition (high flexibility, short time to market and product cycle life time). Consequently companies build international co-operations focusing on own core competences to stay competitive. This leads to structural changes which often not only cross company but even country bounda...

  16. Investigations of the ratios of stable carbon isotopes in atmospheric relevant VOC using simulation and field experiments; Untersuchungen der Verhaeltnisse stabiler Kohlenstoffisotope in atmosphaerisch relevanten VOC in Simulations- und Feldexperimenten

    Energy Technology Data Exchange (ETDEWEB)

    Spahn, Holger

    2010-07-01

    Volatile organic compounds (VOC) play an important role in the regional and global atmospheric chemistry. The author of the contribution under consideration reports on the analysis of the ratios of stable carbon isotopes ({delta}({sup 13}C) analysis) in atmospheric VOCs. At first, the state of the art of this analytical technique is described. For the first time {delta}({sup 13}C) values of different monoterpenes have been determined in the investigation of vegetable emissions at a plant chamber. By means of the oxidation of {beta}-pinene by ozone in an aerosol chamber, the kinetic isotope effect of this reaction was determined. In southern Germany, air samples for the {delta}({sup 13}C) analysis were collected using a zeppelin. This enables a height-resolved measurement of {delta}({sup 13}C) values. Based on these measurements, the average photochemical age for methanol, toluene and p-xylene at different heights was calculated.

  17. Characterization of oxidation resistance of stainless steels at high temperature by metallographic examinations and in-situ electrical resistance measurements; Charakterisierung der Oxidationsbestaendigkeit in nichtrostenden Staehlen bei hoher Temperatur durch Metallographische Untersuchungen und In-Situ-Messungen des elektrischen Widerstands

    Energy Technology Data Exchange (ETDEWEB)

    Bruncko, Mihael; Rudolf, Rebeka; Anzel, Ivan [Maribor Univ. (Slovenia). Faculty of Mechanical Engineering; Mehrabi, Kambiz [Pankl Drivetrain Systems GmbH und Co. KG, Kapfenberg (Austria); Kneissl, Albert C. [Leoben Univ. (Austria). Dept. of Physical Metallurgy and Materials Testing

    2013-07-01

    Practically all metals and alloys survive high-temperature exposure by growing oxide scales and/or by precipitation of the oxide particles in the matrix. Formed products can grow in shape of external oxide layers on surfaces, or as discrete oxide particles precipitated in a metal matrix. The first case represents external oxidation, and the other case is called internal oxidation. These processes are very important, because they determine the properties and applicability of metallic materials. Generally, they are undesired, because they cause deterioration of the mechanical properties and decomposition of metallic material. On the other side, the controlled process of external oxidation could be used for formation of protective coatings and the internal oxidation for dispersion strengthening of materials. In this paper we present monitoring of high-temperature oxidation of X12Cr13 stainless steel by in-situ electrical resistance measurements at different annealing temperatures in the air atmosphere. We determined the kinetics of oxide scale formation and its morphology with additional metallographic examination made by optical and scanning electron microscopy. The results of this research work show that in-situ monitoring and characterization of high-temperature oxidation present a strong tool that will contribute to a better fundamental understanding of the phenomena that occur during high-temperature oxidation of metallic materials. (orig.)

  18. Numerical investigations of instationary heating processes at motor bearings by means of differently coupled methods of calculation; Numerische Untersuchungen instationaerer Aufheizvorgaenge an einem Motorlager unter Verwendung verschiedener gekoppelter Berechnungsmethoden

    Energy Technology Data Exchange (ETDEWEB)

    Disch, Mario; Wittmeier, Felix; Widdecke, Nils; Wiedemann, Jochen [Forschungsinstitut fuer Fahrzeugmotoren und Kraftfahrwesen (FKFS), Stuttgart (Germany); Reister, Heinrich; Weidmann, Ernst-Peter [Daimler AG, Sindelfingen (Germany)

    2012-11-01

    In the vehicle development process at Daimler, thermal protection is an important task that has to be fulfilled. In the early stages of car development numerical analysis techniques are used to ensure that all critical components stay well below given temperature limits. Especially engine mounts are in the focus of investigation due to the geometrical design and the arrangement next to hot exhaust components. For a better understanding of the complex heat transfer mechanisms taking place in this part and as a first step into transient full Vehicle Thermal Management (VTM) computation, two different transient computational analyses are performed and described in this paper. The first one is the Conjugate Heat Transfer method (CHT) in which convection, conduction and radiation phenomena are solved simultaneously. The second one is a COSIM-method in which fluid and solid structures are splitted into two different simulations and brought to interaction by exchanging data at predetermined points. The major problem in transient computation is that thermal time scales on solid and fluid structures vary over a wide range. Using CHT a fine temporal discretization is needed for fluid and solid computation causing an enormous computational effort. In the COSIM-method solid structures are computed unsteady while the corresponding fluid is treated as steady and recalculated after each exchange. Corresponding measurements at an engine mount test rig show that both transient coupling schemes fit well to unsteady experimental results. In conclusion it can be said that the COSIM-method is an effective alternative to CHT computations for transient thermal applications. Computational and modeling effort can be reduced considerably especially for larger time scales which are relevant for full VTM computations. (orig.)

  19. Theoretical and experimental studies on the improvement of the time structure of the extracted electron beam from the stretcher ring ELSA; Theoretische und experimentelle Untersuchungen zur Verbesserung der Zeitstruktur des extrahierten Elektronenstrahls aus dem Stretcherring ELSA

    Energy Technology Data Exchange (ETDEWEB)

    Neckenig, M.

    1993-03-01

    The Electron Stretcher Accelerator ELSA of Bonn University is the first electron-pulse-stretcher-ring in the GeV-range. It delivers an external electron beam in the energy range from 500 MeV to 3.5 GeV, with a current between 10 pA and 100 nA, depending on the demands of the experiments. A synchrotron is used to preaccelerate the electrons to energies between 500 MeV and 1.8 GeV. In this energy-range, ELSA is used in the pure stretcher-mode, whereas for higher energies it is used as a post accelerator. For beam extraction, a third-integer resonance, driven by sextupoles, is applied. The problems, delimiting the duty-factor of the extracted beam in the pure stretcher-mode, have been investigated and solved. In this mode, duty-factors - measured by coincidence methods - of up to 55% have been reached, which are of the order of the theoretical limit for the applied extraction method of about 60%. (orig.) [Deutsch] Ziel dieser Arbeit war es, die Phaenomene, die das Tastverhaeltnis des aus ELSA extrahierten Strahles beeinflussen, zu verstehen. Aus dem gewonnenen Verstaendnis heraus sollten Massnahmen getroffen werden, um das Tastverhaeltnis zu verbessern. Die Effekte, die ein gutes Tastverhaeltnis in der Vergangenheit verhindert haben, waren in der Hauptsache ein Stromrippel in den Netzgeraeten der Hauptmagnete sowie die Extraktion aus dem Synchrotron, die nur eine schlechte Fuellung von ELSA erlaubte. Der Rippel wurde durch den Einbau von Filtern in die Netzgeraete behoben. Bei den gegenwaertigen Extraktionszeiten von 20 msec spielt der Rippel nur noch eine geringe Rolle. Die Extraktion aus dem Synchrotron wurde modifiziert, so dass ohne Beschaffung neuer Komponenten eine Verbesserung der ELSA-Fuellung von 40% auf maximal 75% moeglich wurde. Durch eine Reihe von Massnahmen konnte der Wert des Tastverhaeltnisses von 6%-7% kurz nach der Inbetriebnahme auf heute 50%-55% gesteigert werden. Die Extraktion kann durch ein einfaches Modell beschrieben werden, dass alle Phaenomene erklaert, die im praktischen Betrieb einen Einfluss auf das Tastverhaeltnis haben. Aus dem Modell wurde ein Algorithmus abgeleitet, der die automatische Erzeugung einer Steuerkurve fuer die Veraenderung des Maschinenarbeitspunktes waehrend der Extraktion erlaubt. Es konnte gezeigt werden, dass der Mechanismus der Resonanzextraktion aus ELSA verstanden ist, was dadurch untermauert wird, dass sich das erreichte Tastverhaeltnis sehr gut mit dem Wert deckt, der theoretisch bei Beruecksichtigung der erkannten Effekte berechnet werden kann.

  20. Transfer experiments, light microscopy and electron microscopy studies on the contribution of procaryotes to the novel forest decline patterns. Final report. Uebertragungsversuche, licht- und elektronenmikroskopische Untersuchungen zur Pruefung der ursaechlichen Beteiligung von Prokaryonten (MLO, RLO) an den neuartigen Waldschaeden. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Petzold, H.

    1989-01-01

    The now terminated research project was to clarify if procaryotes are a causal part of the novel damage to forests. For this extensive microscopic analyses on differently damaged spruce trees and several silver firs from the forest damage areas in the Fichtelgebirge and Bayerischer Wald mountains were made. Beyond this it was attempted to transfer possible phytopathogenic agents from damaged forest trees to healthy young trees of the same kind by pruning. In addition it was attempted to transfer with the aid of parasitic plants of the species Cuscuta possibly occurring mycoplasms of trees suffering from acute yellowing to the test plant Catharanthus roseus, the most suitable for this. Additional tests served to transfer defined MLO from Catharanthus onto healthy seedlings of diverse deciduous and coniferous trees to determine if forest trees are susceptible to the mycoplasmoses common in Germany. (orig./MG).

  1. Investigations on the emission of air pollutants from small-scale firing plants during the combustion of cereals, straw and similar plant materials; Untersuchungen zur Emission von Luftschadstoffen aus Kleinfeuerungsanlagen bei der Verbrennung von Getreide, Stroh und aehnlichen pflanzlichen Stoffen

    Energy Technology Data Exchange (ETDEWEB)

    Kalkoff, Wolf-Dieter; Maiwald, Birk; Wolf, Stephan

    2013-05-15

    The purpose of the present field study by the State Environmental Protection Office and the State Institution for Agriculture, Forestry and Horticulture of Saxony Anhalt was to measure emissions of relevant pollutants during the combustion of biogenic fuels such as cereals, straw and similar plant materials in exemplary firing installations. In spite of considerable development efforts on the part of manufacturers there are still problems to be solved with some fuels in meeting the tightened limit values of the First Emission Control Ordinance while ensuring user-friendly equipment operability. Based on these insights, as well as the experiences gained in the course of the trial programme, the recommendation for problem fuels such as straw and similar materials is to operate the boiler at full load and provide robust, amply dimensioned ash removal equipment.

  2. Calibration measurements and systematic studies on the detection of cosmic particles in the IceTop tank; Eichmessungen und systematische Untersuchungen zum Nachweis kosmischer Teilchen im IceTop-Tank

    Energy Technology Data Exchange (ETDEWEB)

    Martens, Christian

    2012-05-15

    IceCube is an 1 km{sup 3} large observatory at the south pole. It consists of the surface detector IceTop and the underground detector In-Ice. By the detection of Cherenkov Radiation iceCube tries to determine the sources of cosmic radiation and cosmic neutrinos. IceTop possesses a large number of IceTop tanks (ITT), which are filled with ice. In these tanks the Cherenkov radiation of the cosmic radiation can be detected with so-called digital optical modules. By this it is possible to determine the chemical composition of the cosmic radiation. Simultaneously this surface detector serves also as veto for the In-Ice detector. In this bachelor thesis the charge spectra in the ITT at DESY were studied under regardment of the electromagnetic, hadronic, and muonic component. Additionally in cooperation with 6 1 m{sup 2} large scintillator planes by different coincidence conditions a direction selection of the cosmic radiation could be performed. By this the positions of the muon peaks could be considered for different conditions.

  3. Investigations of atmospheric input of polychlorinated dibenzo-p-dioxins and dibenzofurans into pasture. Pt. 1. Texts. Final report; Untersuchungen des atmosphaerischen Eintrags polychlorierter Dibenzo-p-dioxine und Dibenzofurane in Futterpflanzen. T. 1. Textband. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    McLachlan, M.S.; Welsch-Pausch, K.; Koemp, P.

    1998-07-01

    Introduction of PCDD/Fs into the agricultural food chain `atmosphere - fodder - cattle - cows` milk/beef - human` plays a major role in human exposure. The aim of this study was to establish a quantitative relationship between PCDD/Fs immissions and fodder concentrations. The identification of the most important atmospheric pathway of PCDD/F into greenland cultures was conducted under near natural conditions in a combined field/glasshouse experiment. It was found that for the Cl{sub 4-6}DD/Fs dry gaseous and for the Cl{sub 7/8}DD/Fs dry particle-bound deposition was the primary mechanism of uptake. A further greenhouse experiment showed that there is an isomere-unspecific photodegradation of PCDD/Fs on plant surfaces. Dry gaseous deposition, which is the major pathway of atmospheric deposition for the less chlorinated toxicological relevant PCDD/Fs, can be understood as a partitioning process between the gas phase of the atmosphere and the vegetation. Experiments investigating this topic were conducted in the laboratory using PCBs as model substances for the PCDD/Fs. Important knowledge was gained with regard to plant/air partitioning, their dependence on temperature and plant species, the kinetics and reversibility of the process. No partitioning equilibrium between the vegetation and the gas phase of the atmosphere was approached for the PCDD/Fs. The accumulation of PCDD/Fs in agricultural greenland was therefore controlled by a gaseous deposition velocity. In two typical German agricultural regions representative gaseous and particle-bound deposition velocities were determined, which were all in all quite constant and independent of the different exposure conditions. All results from this study were incorporated into a mathematical model of the accumulation of PCDD/Fs and PCBs in greenland. Based on air concentration, plant species composition and growth, temperature and physical-chemical properties of the chemical the model is able to predict the concentration of a chemical in the plants as a function of time. A validation of this model for the less chlorinated PCBs showed, that the measured plant/air-partitioning and the corresponding components of the model can be extrapolated to environmental conditions. This model summarizes the results of this study and provides a valuable tool in understanding the enrichment of semivolatile lipophilic organic compounds in agricultural plants. (orig.) [Deutsch] Fuer die Exposition des Menschen gegenueber PCDD/F spielt die landwirtschaftliche Nahrungskette `Atmosphaere - Futterpflanze - Kuh - Milch/Rindfleisch - Mensch` die entscheidende Rolle. Das uebergreifende Ziel dieses Vorhabens war die Erstellung einer quantitativen Beziehung zwischen der Immissionsbelastung mit PCDDF/F und Futtermittelkonzentrationen. Die Identifizierung der wichtigsten atmosphaerischen Eintragswege von PCDD/F in Gruenlandpflanzen wurde unter naturnahen Bedingungen im Rahmen eines kombinierten Gewaechshaus-Freilandversuches durchgefuehrt. Es wurde deutlich, dass fuer die Cl{sub 4-6}DD/F die trockene gasfoermige und fuer die Cl{sub 7/8}DD/F die trockene partikelgebundene Deposition der Hauptaufnahmepfad ist. Aus einem weiteren Gewaechshausversuch ergaben sich deutliche Hinweise auf einen isomerenunspezifischen Photoabbau von PCDD/F auf Pflanzenoberflaechen. Die trockene gasfoermige Deposition, die den Haupteintragsweg fuer die niederchlorierten toxikologisch relevanten PCDD/F darstellt, kann als Verteilung einer Verbindung zwischen der Gasphase der Atmosphaere und der Vegetation angesehen werden. Es wurde eine Reihe von Laborversuchen mit PCT, die als Modellverbindungen fuer die PCDD/F dienten, durchgefuehrt. Es konnten wichtige Erkenntnisse hinsichtlich der Pflanzen/Luft-Verteilung, ihrer Abhaengigkeit von Temperatur und Pflanzenart, ihrer Kinetik und Reversibilitaet gewonnen werden. Fuer die PCDD/F konnte keine Gleichgewichtseinstellung zwischen Pflanze und Atmosphaere beobachtet werden. Die Anreicherung von PCDD/F in Futtermitteln wird folglich durch eine gasfoermige Depositionsgeschwindigkeit bestimmt. An zwei fuer Deutschland typischen landwirtschaftlichen Standorten wurden repraesentative gasfoermige und, analog dazu, partikelgebundene Depositionsgeschwindigkeiten gemessen, die insgesamt unabhaengig von den Standortbedingungen eine relativ geringe Variationsbreite aufwiesen. Die zahlreichen Teilergebnisse dieses Forschungsvorhabens wurden in ein mathematisches Modell der Anreicherung von PCDD/F und PCB in Gruenland integriert. Auf der Basis von Luftbelastung, Artenzusammensetzung und Wachstum des Bestandes, Temperatur und Substanzeigenschaften berechnet dieses Modell die Konzentration einer Verbindung im Gruenlandaufwuchs als Funktion der Zeit. Eine Modellvalidierung konnte fuer die niederchlorierten PCB die gute Uebertragbarkeit der Laborversuche zur Pflanzen/Luft/Verteilung und der entsprechenden Modellkomponenten zeigen. Durch dieses Modell konnten die Teilergebnisse dieses Vorhabens zu einer sinnvollen Einheit zusammengefasst und somit ein wertvolles Werkzeug zum Verstaendnis der Anreicherung von mittelfluechtigen lipophilen organischen Verbindungen in landwirtschaftlichen Nutzpflanzen geschaffen werden. (orig.)

  4. Quantitative CT assessment of proximal femoral bone density. An experimental study concerning its correlation to breaking load for femoral neck fractures; Quantitative CT des proximalen Femurs. Experimentelle Untersuchungen zur Korrelation mit der Bruchlast bei Schenkelhalsfrakturen

    Energy Technology Data Exchange (ETDEWEB)

    Buitrago-Tellez, C.H.; Schulze, C.; Gufler, H.; Langer, M. [Abt. Roentgendiagnostik, Radiologische Universitaetsklinik, Albert-Ludwigs-Univ. Freiburg (Germany); Bonnaire, F.; Hoenninger, A.; Kuner, E. [Abt. Unfallchirurgie, Chirurgische Universitaetsklinik, Albert-Ludwigs-Univ. Freiburg (Germany)

    1997-12-01

    Purpose: In an experimental study, the correlation between the trabecular bone density of the different regions of the proximal femur and the fracture load in the setting of femoral neck fractures was examined. Methods: The bone mineral density 41 random proximal human femora was estimated by single-energy quanitative CT (SE-QCT). The trabecular bone density was measured at the greatest possible extracortical volume at midcapital, midneck and intertrochanteric level and in the 1 cm{sup 3} volumes of the centres of these regions in a standardised 10 mm thick slice in the middle of the femoral neck axis (in mg/ml Ca-hydroxyl apatite). The proximal femora were then isolated and mounted on a compression/bending device under two-legged stand conditions and loaded up to the point when a femoral neck fracture occurred. Results: Statistical analysis revealed a linear correlation between the trabecular bone density and the fracture load for the greater regions, with the highest value in the maximal area of the head (coefficient factor r=0.76). Conclusion: According to our data, the measurement of the trabecular bone by SE-QCT at the femoral head is a more confident adjunct than the neck or trochanteric area to predict a femoral neck fracture. (orig.) [Deutsch] Ziel: In einer experimentellen Versuchsserie wurde der Zusammenhang zwischen der Knochendichte an verschiedenen Lokalisationen des proximalen Femurs und der maximalen Last bei der Entstehung von Schenkelhalsfrakturen (Bruchlast) untersucht. Methode: An 41 frisch entnommenen proximalen Leichenfemora wurde die trabekulaere Knochendichte mit Hilfe der Ein-Energie Quantitativen Computertomographie (SE-QCT) bei einer Schichtdicke von 10 mm in der Mitte der Schenkelhalsachse bestimmt. Erfasst wurden die maximale extrakortikale, zylinderfoermige Messregion im Hueftkopf, Schenkelhals und der Intertrochantaerregion sowie das 1 cm{sup 3} umfassende Zentrum dieser Regionen. Die Praeparate wurden unter Zweibeinstandbedingungen Kompressions-Biegungskraeften ausgesetzt und der Bruchpunkt beim Eintritt der Schenkelhalsfraktur ermittelt. Ergebnisse: Es zeigte sich ein linearer Zusammenhang zwischen der Spongiosaknochendichte (in mg/ml Ca-Hydroxylapatit) in allen groesseren Messregionen und der ermittelten Bruchlast mit der besten Vorhersagewahrscheinlichkeit fuer die Region Hueftkopf (Korrelationskoeffizient r=0,76). Schlussfolgerung: Die Messung der trabekulaeren Knochendichte mittels SE-QCT im Hueftkopf ist fuer die Vorhersage einer Frakturgefaehrdung im Schenkelhaslbereich unter den gegebenen Testbedingungen aussagefaehiger als Messungen im Schenkelhals oder in der Trochanterregion. (orig.)

  5. Studies on Ta-Ni alloys as high-temperature braze for SiC-SiC joined products; Untersuchungen zu Ta-Ni-Legierungen als Hochtemperaturlot fuer SiC-SiC Verbunde

    Energy Technology Data Exchange (ETDEWEB)

    Triebert, Anke; Matthey, Bjoern; Martin, Hans-Peter [Fraunhofer Institut fuer Keramische Technologien und Systeme (IKTS), Dresden (Germany)

    2011-07-01

    Active metal brazes have been already established for a number of decades. The current progress of processing technologies and engineering require new and powerful materials also for high-temperature applications. Up to now there are little technically and industrially applicable brazing materials for operation temperatures above 800 C. The investigations described in this paper concerning the Ta-Ni system intend to be the start of a braze material development, which delivers ceramic-ceramic or ceramic-metal joined products. Besides principal considerations and experiments with regard to the investigated material system of Ta-Ni active metal brazing tests to join SIC-SIC components are presented. The joined ceramic component samples are characterized focusing on their materials structure within the joining zone, their crystalline phases of the braze and their mechanical strength at room temperature and high temperatures. The achieved properties demonstrate that Ta-Ni brazes have the potential for future high temperature brazes for ceramics materials. (orig.)

  6. Development and validation of a dispersion model for aerosols and studies on their coagulation as potential influence source; Entwicklung und Validierung eines Ausbereitungsmodells fuer Aerosole und Untersuchungen zu deren Koagulation als potentieller Einflussquelle

    Energy Technology Data Exchange (ETDEWEB)

    Lodomez, Philipp

    2010-09-15

    In the context of dispersion modelling of aerosols in the vicinity of agricultural sites the adoption of dynamical models is more and more usual. Such a model, STAR3D (Simulated Transmission of Aerosols 3D) was newly developed. It is based on the numerical evaluation of the Navier-Stokes-Equations and the subsequent calculation of the particle trajectories using the Langevin-Equation. In the course of the transmission different effects like the sedimentation, diffusion and coagulation of the particles must be considered. For the estimation of the influence of the coagulation a test chamber was build. It could be shown, that the effect of the particle coagulation can be neglected for dispersion modelling in outdoor areas. Finally a field survey was arranged to evaluate STAR3D. At twelve measurement points the mean deviation between the measured and simulated values was 24 percent. (orig.)

  7. Analytic studies on pollutant deposition through domestic coal combustion - influence of the current structural change on pollution in an urban region. Final report; Analytische Untersuchungen zum Schadstoffeintrag durch den Hausbrand - Auswirkungen des gegenwaertigen Strukturwandels auf die urbane Belastungssituation. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Engewald, W.; Knobloch, T.; Asperger, A.

    1996-12-31

    In the present paper the author reports on the continuation of an OEKOR part project in which he had undertaken a chemical characterisation of emissions from domestic brown coal combustion. On the basis of a partitioning by land use of the Greater Leipzig region he initiated long-term observations of local pollution levels for the various structural types of land. The aim of the work was to facilitate a comprehensive analysis of local air quality in terms of VOC levels. The current concern about VOCs results from the toxicological risk they have been proven to pose to the human organism and from their relevance to the chemistry of the atmosphere (e.g., as precursors of ground-level ozone and other oxidising agents). The task to be accomplished was broken down into the following main steps: Development and trial of a sampling and analysis method for determining an as wide a spectrum of environmental VOCs as possible; elaboration of a measuring strategy for obtaining results of high representativeness and power; installation and operation of pollution monitoring sites in selected structural types of area characteristic of Leipzig; execution of measuring campaigns of several weeks each at selected sites during both winter and summer periods. (orig./MSK) [Deutsch] In Fortsetzung eines vom Berichterstatter bearbeiteten OeKOR-Teilprojekts zur chemischen Charakterisierung von Emissionen aus dem Hausbrand von Braunkohle galt es, auf der Basis einer an der Flaechennutzung ausgerichteten Untergliederung der Stadtregion Leipzig in unterschiedliche Strukturtypen langfristige Immissionsbeobachtungen zu beginnen mit dem Ziel, eine Zustandsanalyse des Umweltmediums Luft bezueglich des Gehalts an fluechtigen organischen Verbindungen (VOC) in ihrer gesamten Breite zu ermoeglichen. Das verstaerkte Interesse an diesen Verbindungen resultiert aus dem fuer eine Reihe von VOC belegten toxikologischen Gefahrenpotential fuer den menschlichen Organismus sowie ihrer atmosphaerenchemischen Relevanz (u.a. als Vorlaeufersubstanzen fuer bodennahes Ozon und andere Oxidantien). Hieraus ergaben sich fuer das Teilprojekt die folgenden methodischen Schwerpunkte: - Entwicklung und Erprobung einer Probenahme- und Analysenmethode zur Bestimmung eines moeglichst breiten Spektrums von Spuren fluechtiger organischer Verbindungen im Immissionsbereich - Erarbeiten einer Messstrategie, die Ergebnisse hoher Repraesentanz und Aussagekraft gewaehrleistet - Installation und Betrieb von Immissionsmessplaetzen in ausgewaehlten, fuer Leipzig typischen Stadtstrukturen - Durchfuehrung jeweils mehrwoechiger Messkampagnen an den ausgewaehlten Standorten in Sommer- und Winterperioden. (orig./MSK)

  8. Delayed somatic effects following extended radiotherapy. Studies of 135 patients with Hodgkin's disease in long-term remission (Freiburg collective, treatment years 1948 to 1974). Untersuchungen ueber somatische Spaetschaeden nach ausgedehnter Strahlentherapie

    Energy Technology Data Exchange (ETDEWEB)

    Slanina, J

    1977-01-01

    A group of 135 patients who suffered from Hodgkin's disease with long-term remission following radiotherapy was investigated. By restricting the investigations to the patient group with long-term remission and correlative examinations, it was tried to differentiate between exclusive or principal delayed radiation effects and delayed effects due to other factors. The study reports about the most significant results obtained in the fields of catamnesis, laboratory diagnostics, hematology, pulmology, cardiology, thyroid function tests, neurology, andrology and dermatology. Due to the numerous detectable delayed effects the group of patients with long-term remission receives a special status. Although those effects are in no proportion to the deletary risks of an untreated Hodgkin's disease and though they are consequently tolerable in the present state of the therapeutic development, they must initiate the completion of the therapeutic concept including performance of radiotherapy and aftercare, because only then the risk for the patient provoked by these effects, which ranges beyond the malignity of this disease can be reduced or prevented.

  9. Noctilucent clouds in the polar sumer mesopause: Investigations using the ALOMAR Rayleigh/Mie/Raman Lidar; Leuchtende Nachtwolken an der polaren Sommermesopause: Untersuchungen mit dem ALOMAR Rayleigh/Mie/Raman Lidar

    Energy Technology Data Exchange (ETDEWEB)

    Baumgarten, G.

    2001-09-01

    Noctilucent clouds (NLC) are rare, tenuous clouds in the terrestrial atmosphere that occur at polar latitudes in summer near 83 km altitude. These clouds where studied using the ALOMAR Rayleigh/Mie/Raman lidar located at 69 N, 16 E. The depolarization of light, which was backscattered on NLC particles was measured for the first time by the ALOMAR RMR-Lidar. Considering the small ratio of particle size over wavelength an unexpectedly large depolarization of 1.7% was observed. Comparing this result to T-matrix calculations for scattering on randomly oriented aspherical particles implies that the shape of the NLC particles is needle like. The ALOMAR RMR-Lidar is a twin-lidar equipped with two steerable telescopes which were used to observe a single NLC layer in two separate measurement volumes about 50 km apart at NLC altitudes. Cross correlation technique reveal the layer to be tilted with imbedded periodic horizontal structures showing wavelengths of about 30 to 50 km. These structures drift horizontally through the measurement volumes rather than being microphysically formed during the observation period. (orig.)

  10. Investigations of methane emissions from civil water wells on the Bentheim-Salzbergen ridge near Schuettorf; Untersuchungen von Methangasaustritten aus zivilen Brunnenbohrungen im Bereich des Bentheim-Salzbergener Sattels bei Schuettorf

    Energy Technology Data Exchange (ETDEWEB)

    Heilmann, A. [Technische Univ. Clausthal (Germany). Inst. fuer Erdoel- und Erdgastechnik; Sattler, C.D. [Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany). Inst. fuer Geologie und Palaeontologie

    2007-09-13

    In a water well sunk in the Grafschaft Bentheim region of northern Germany, small volumes of methane were emitted regularly and large volumes of methane in eruptions at irregular intervals. After some extreme gas eruptions in 2002 and 2004, the Grafschaft Bentheim district government initiated a project to investigate underground conditions in the region between Nordhorn and Bad Bentheim in order to prevent potential hazards to the locals population. The main purpose of the project was to provide information on underground mechanisms as far as possible in order to develop long-term safety strategies for freshwater supply in the region. (orig.)

  11. Investigation of a free electron laser oscillator in the X-ray wavelength regime for the European XFEL; Untersuchungen zu einem Freie-Elektronen-Laser-Oszillator im Roentgen-Wellenlaengenbereich fuer den European XFEL

    Energy Technology Data Exchange (ETDEWEB)

    Zemella, Johann Christian Uwe

    2013-09-15

    In this thesis an X-ray free electron laser oscillator for the European XFEL is described. Such an oscillator consists of at least two Bragg deflecting crystals, in this content two or four Diamond crystals, focussing mirrors and an undulator. The advantage of Diamond is caused by the high reflectivity and the high thermal conductivity, which is necessary for dissipate the absorbed energy out of the center of the crystal. In context of this thesis the principle layout of an XFELO for the European XFEL and the FEL process is presented. Effects on the FEL process due to the disturbances of the electron beam or the XFELO cavity are discussed. As second aspect the thermal evolution in the crystal under absorbed XFELO-pulses is investigated. An experiment for the investigation of the thermal evolution of crystals under simulated XFELO conditions is presented.

  12. Investigations of the boundary conditions of acicular ferrite formation in fast-quenched welded materials. Final report; Untersuchungen der Randbedingungen fuer die Bildung von 'acicular ferrite' in Schweissguetern bei schneller Abkuehlung. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Dilthey, U.; Biesenbach, M.

    2000-06-19

    The authors investigated the boundary conditions in which a fine-grained ferritic needle structure with sufficient low-temperature toughness is obtained in conditions of extreme heating and cooling. Alloy compositions and welding boundary conditions were investigated for laser welding, electron beam welding in a vacuum and electron beam welding at atmospheric pressure. [German] Im Rahmen dieser Arbeit soll untersucht werden, welche Randbedingungen erfuellt sein muessen, damit sich unter extremen Aufheiz- und Abkuehlbedingungen, wie sie bei den Strahlschweissverfahren vorliegen, ein feinkoerniges nadelferritisches Gefuege mit ausreichend hoher Tieftemperaturzaehigkeit bildet. Diesbezueglich ist fuer die Strahlschweissverfahren Laserstrahlschweissen, Elektronenstrahlschweissen im Vakuum und Elektronenstrahlschweissen unter Atmosphaerendruck zu ermitteln, welche Legierungszusammensetzungen diese Voraussetzungen erfuellen und wie sie unter realen Schweissbedingungen verwirklicht werden koennen. (orig.)

  13. Fundamental investigation of hybrid high-temperature superconductor-semiconductor sensors for magnetic signals in non-destructive evaluation. Final report; Grundlegende Untersuchungen hybrider Hochtemperatursupraleiter-Halbleiter-Magnetfelddetektoren auf Siliziumsubstraten fuer Anwendungen in der zerstoerungsfreien Pruefung. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Seidel, P.; Schmidl, F.; Linzen, S.; Schmidt, F.; Scherbel, J.

    2002-11-01

    A new magnetic sensor was realized using a Hall magnetometer coupled to an antenna out of high-temperature superconducting material. The resolution of the magnetometer was improved and a noise-limited field resolution of the system of 2.7 nT/{radical}(Hz) was obtained. The necessary thin film technology was developed and optimized. Further improvements will result in 0.5 nT/{radical}(Hz). The sensors were realized as single sensors as well as sensor arrays and successfully tested in a system for non-destructive evaluation. Within this system the cooling was established by a cryocooler which also cools down the electronics to about 80 K. (orig.) [German] Es wurde ein neuartiger Magnetfeldsensor realisiert, bei dem ein Hallmagnetometer mit einer Antenne aus Hochtemperatursupraleitenden Material gekoppelt wird. Die Magnetometerempfindlichkeit wird dadurch kiar verbessert und eine rauschbegrenzte Feldaufloesung des Systems von 2,7 nT{radical}(/Hz) erreicht. Die zur Herstellung noetige hybride Duennschichttechnologie wurde entwickelt und optimiert. Durch Layoutverbesserungen erscheinen Aufloesungen von 0,5 nT/{radical}(Hz) realisierbar. Die Sensoren wurden als Einzelsensor und Sensorarrays realisiert und in einer Anlage zur zerstoerungsfreien Pruefung erfolgreich getestet. Dabei erfolgte die Kuehlung mittels Kleinkuehler, der auch die Verarbeitungselektronik auf 80 K kuehlt. (orig.)

  14. Electrical and optical measurements on a single InAs quantum dot using ion-implanted micro-LEDs; Elektrische und optische Untersuchungen an einem einzelnen InAs-Quantenpunkt mit Hilfe ionenstrahlimplantierter Mikro-LEDs

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, R.F.

    2006-10-19

    The goal of this present thesis was to electrically and optically address a single InAs quantum dot. Therefore micro-structured quantum-dot-LEDs with an emission area smaller than 1 {mu}m{sup 2} were developed. One major part of this work was contributed to optimizing several steps of the micro-LED fabrication process. To be able to compare the electrical conductivity obtained from Hall-measurements to the expected values, the implantation profile was investigated both theoretically and experimentally. As the thermal annealing step had to be performed in the growth chamber of the MBE-system several annealing parameters had to be modified to achieve optimum electrical conductivity and quantum dot growth. For one of the Be-implanted pin-samples the principle of the single-quantum-dot-LEDs could be proved. The smallest device of this sample, with nominal stripe widths of 150 nm (FIB-stripe) and 400 nm (top-stripe), showed typical features of a single quantum dot. In the high-resolution EL-spectra of this device three extremely sharp emission lines were observed which clearly could be assigned to the electron-hole recombination from a single quantum dot. To further identify the origin of these lines their optical intensities were plotted against the injection current. From this plot it could be deduced, that the first evolving line clearly belongs to the simple exciton 1X. The following lines could be assigned to the decay of the biexciton 2X and the triexciton 3X{sub s}, respectively. With increasing bias all three lines show a pronounced red-shift due to the quantum confined Stark effect (QCSE). To identify the charge state of the observed excitonic lines, additional high-resolution IV curves were taken. (orig.)

  15. Epitaxial growth of 3C-SiC by using C{sub 60} as a carbon source; Untersuchungen zum epitaktischen Wachstum von 3C-SiC bei Verwendung einer C{sub 60}-Kohlenstoffquelle

    Energy Technology Data Exchange (ETDEWEB)

    Schreiber, Sascha

    2006-01-15

    Within this work epitaxial 3C-SiC-films were grown on Si(001) substrates and on ion beam synthesized 3C-SiC(001) pseudo substrates. A rather new process was used which is based on the simultaneous deposition of C60 and Si. In order to set up the necessary experimental conditions an ultra-high vacuum chamber has been designed and built. A RHEED system was used to examine SiC film growth in-situ. Using the described technique 3C-SiC films were grown void-free on Si(001) substrates. Deposition rates of C60 and Si were chosen adequately to maintain a Si:C ratio of approximately one during the deposition process. It was shown that stoichiometric and epitaxial 3C-SiC growth with the characteristic relationship (001)[110]Si(001)[110]3C-SiC could be achieved. TEM investigations revealed that the grown 3C-SiC films consist of individual grains that extend from the Si substrate to the film surface. Two characteristic grain types could be identified. The correlation between structure and texture of void-free grown 3C-SiC films and film thickness was studied by X-ray diffraction (XRD). Pole figure measurements showed that thin films only contain first-order 3C-SiC twins. With higher film thickness also second-order twins are found which are located as twin lamellae in grain type 2. Improvement of polar texture with increasing film thickness couldn't be observed in the investigated range of up to 550 nm. On ion beam synthesized 3C-SiC pseudo substrates homoepitaxial 3C-SiC growth could be demonstrated for the first time by using a C{sub 60} carbon source. In respect to the crystalline quality of the grown films the surface quality of the used substrates was identified as a crucial factor. Furthermore a correlation between the ratio of deposition rates of C{sub 60} and Si and 3C-SiC film quality could be found. Under silicon-rich conditions, i.e. with a Si:C ratio of slightly greater one, homoepitaxial 3C-SiC layer-by-layer growth can be achieved. Films grown under these conditions showed the highest crystalline quality within this work. However using a Si:C ratio smaller one in the gas phase during film deposition, i.e. growing under carbon-rich conditions, leads to homoepitaxial 3C-SiC island growth. Films synthesized under these conditions are of significantly lower quality. But despite of the excess supply of carbon during the deposition process they exhibit a Si:C=1:1 stoichiometry. (orig.)

  16. Evaluation of radiation dose in 64-row whole-body CT of multiple injured patients compared to 4-row CT; Evaluation der Strahlendosis bei Polytrauma-CT-Untersuchungen eines 64-Zeilen-CT im Vergleich zur 4-Zeilen-CT

    Energy Technology Data Exchange (ETDEWEB)

    Harrieder, A.; Geyer, L.L.; Koerner, M.; Deak, Z.; Wirth, S.; Reiser, M.; Linsenmaier, U. [Ludwig-Maximilians-Univ. Muenchen (Germany). Inst. fuer Klinische Radiologie

    2012-05-15

    Purpose: To evaluate radiation exposure in whole-body CT (WBCT) of multiple injured patients comparing 4-row multidetector computed tomography (MDCT) to 64-row MDCT. Materials and Methods: 200 WBCT studies were retrospectively evaluated: 92 4-row MDCT scans and 108 64-row MDCT scans. Each CT protocol was optimized for the particular CT system. The scan length, CT dose index (CTDI), and dose length product (DLP) were recorded and analyzed for radiation exposure. The mean effective dose was estimated based on conversion factors. Student's t-test was used for statistical analysis. Results: The mean CTDI{sub vol} values (mGy) of the thorax and abdomen were significantly reduced with 64-row MDCT (10.2 {+-} 2.5 vs. 11.4 {+-} 1.4, p < 0.001; 14.2 {+-} 3.7 vs. 16.1 {+-} 1.7, p < 0.001). The DLP values (mGy x cm) of the head and thorax were significantly increased with 64-row MDCT (1305.9 {+-} 201.1 vs. 849.8 {+-} 90.9, p < 0,001; 504.4 {+-} 134.4 vs. 471.5 {+-} 74.1, p = 0.030). The scan lengths (mm) were significantly increased with 64-row MDCT: head 223.6 {+-} 35.8 vs. 155.5 {+-} 12.3 (p < 0.001), thorax 427.4 {+-} 44.5 vs. 388.3 {+-} 57.5 (p < 0.001), abdomen 520.3 {+-} 50.2 vs. 490.8 {+-} 51.6 (p < 0.001). The estimated mean effective doses (mSv) were 22.4 {+-} 2.6 (4-row MDCT) and 24.1 {+-} 4.6 (64-row MDCT; p = 0.001), resulting in a percentage increase of 8 %. Conclusion: The radiation dose per slice of the thorax and abdomen can be significantly decreased by using 64-row MDCT. Due to the technical advances of modern 64-row MDCT systems, the scan field can be adapted to the clinical demands and, if necessary, enlarged without time loss. As a result, the estimated mean effective dose might be increased in WBCT. (orig.)

  17. IR spectroscopy and quantum-chemical studies on the binding and activation of CO on metal catalysts. IR-spektroskopische und quantenmechanische Untersuchungen zur Bindung und Aktivierung von Kohlenmonoxid an Metallkatalysatoren

    Energy Technology Data Exchange (ETDEWEB)

    Miessner, H.

    1988-05-04

    The present study is concerned with the investigation of the interaction and activation of CO with metal carrier catalysts. In connection with the catalytic investigations on the generation of oxygenous products from synthesis gas or methanol, attention was directed mainly to rhodium carrier catalysts. The aim of the investigations was to characterise the rhodium catalysts, which, during CO hydrogenation, occupy an exceptional position among the metals of the 8th auxiliary group, and which show a special selectivity with respect to oxygenous C{sub 2}{sup +} products. Since the influence of the carrier is of a decisive importance in this connection, a whole lot of carriers were incorporated in the study: Al{sub 2}O{sub 3}, SiO{sub 2}, TiO{sub 2}, ZnO, MgO, X and Y zeolites with different Si:Al ratios of 1.1-100. To solve the problems mentioned, IR spectroscopy, particularly with the help of CO as a probe molecule, and quantum-chemical model calculations were applied. For interpretation purposes, the results of catalytic CO hydrogenation and of methanol carbonylation as well as of further physico-chemical investigation methods such as temperature-programmed reduction, the chemisorption of hydrogen and CO and the temperature-programmed desorption of CO were consulted. (orig./EF).

  18. Establishing design criteria for crankshaft thrust bearings in gasoline and diesel engines by computer simulations and experiments. Crankshaft thrust bearing design - final report; Auslegungskriterien fuer Kurbelwellenaxiallager in Otto- und Dieselmotoren durch rechnergestuetzte Simulation und experimentelle Untersuchungen. Axialgleitlagerauslegung - Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Hunsicker, W. [Fachhochschule Mannheim (Germany). Inst. fuer Tribologie; Backhaus, K. [Univ. GH Kassel (Germany). Inst. fuer Maschinenelemente und Konstruktionstechnik; Schubert, W. [KS Gleitlager GmbH, Papenburg (Germany)

    2004-07-01

    Aim of the research-project was it to increase the calculation safety of crank shaft thrust bearings in combustion engines. The project was divided in two parts: (1) A simulation program to analyze the load bearing capacity of axial bearings under mixed lubrication has been developed at the Institut fuer Maschinenelemente und Konstruktionstechnik, University of Kassel. This part of the research-project has been presented at the FVV Herbsttagung in 2003. (2) The test runs with original parts were carried out on a newly designed thrust bearing test rig at the Institut fuer Tribologie, University of Applied Sciences in Mannheim. The following presentation shows the results of part 2. The experimental results show the influence of rotational frequency, load, bearing material, lateral run-out of the tread of the crankshaft and groove pattern. These test runs will help to dimension thrust bearings more efficiently. (orig.)

  19. Analytic studies of test problems of laser welds in consideration of tolerated hardness peaks. Final report; Analytische Untersuchungen der Pruefproblematik an laserstrahlgeschweissten Verbindungen unter besonderer Beruecksichtigung der zu tolerierenden Haertespitzen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    Test methods for laser welds were investigated under the following aspects: 1. Setting a defined cracking path by changing the test piece geometry - is it possible and does it make sense? 2. Can the results obtained with changed test piece geometries be applied to standard test pieces? 3. Is crack displacement typical of small test pieces, or is it observable in real components as well? 4. Should the cracking path be predefined at all if it results in 'non-realistic' fractures? The focus was on notched bar impact tests. [German] Ziel des Forschungsvorhabens war die Ermittlung geeigneter Pruefverfahren zur Charakterisierung einer Laserstrahlschweissnaht. Folgende Fragen sollten geklaert werden: 1. Ist es moeglich und sinnvoll, mit einer Aenderung der Probengeometrie (z.B. Einbringen von Seitenkerben) den Rissverlauf in das aufgehaertete Laserschweissgut zu zwingen? 2. Welche Aussagen liefern uns die Ergebnisse dieser abgeaenderten Probengeometrie und inwiefern sind diese vor allen Dingen beim Kerbschlagbiegeversuch auf die Ergebnisse der standardisierten Probengeometrie zu uebertragen? 3. Ist das Rissauswandern ein nur fuer Kleinproben typisches Verhalten oder wird es auch bei realen Bauteilen beobachtet? 4. Ist es sinnvoll, den Rissverlauf in die sproede, aufgehaertete Schweissnaht zu zwingen, obwohl daraus ein 'realitaetsfernes' Bruchverhalten resultiert? Dabei wurde der Schwerpunkt auf die Untersuchung des Kerbschlagbiegeversuches gelegt. (orig.)

  20. Spectroscopic studies on technetium and silicon. A solid-state laser system for the resonance-ionization spectroscopy; Spektroskopische Untersuchungen an Technetium und Silizium. Ein Festkoerperlasersystem fuer die Resonanzionisationsspektroskopie

    Energy Technology Data Exchange (ETDEWEB)

    Mattolat, Christoph

    2010-11-15

    This doctoral thesis describes advancement and refinement of the titanium:sapphire laser system of the working group LARISSA, Institut fuer Physik, Johannes Gutenberg- Universitaet Mainz and its application to resonance ionization spectroscopy. Activities on the laser systems comprised three major tasks: The output power of the conventional titanium:sapphire lasers could be increased by a factor of two in order to match the needs at resonance ionization laser ion source at ISOL facilities. Additionally, the laser system was complemented by a titanium:sapphire laser in Littrow geometry, which ensures a mode-hop free tuning range from 700 nm to 950 nm, and by an injection seeded titanium:sapphire laser with a spectral width of 20 MHz (in respect to a spectral width of 3 GHz for the conventional lasers). The performance of the new laser system was tested in spectroscopic investigations of highly excited atomic levels of gold and technetium. From the measured level positions the ionization potential of gold could be verified by using the Rydberg-Ritz formula, while the ionization potential of technetium could be determined precisely for the first time. Using the seeded titanium: sapphire laser Doppler-free two-photon spectroscopy inside a hot ionizer cavity was demonstrated. A width of the recorded resonances of 90 MHz was achieved and the hyperfine structure and isotope shift of stable silicon isotopes was well resolved with this method. (orig.)

  1. Geothermal potential of northern Bavaria: Analysis of geothermal resources by evaluation of geophysical temperature logs in drinking water wells and deep wells; Geothermisches Potential Nordbayerns - Untersuchungen der geothermischen Verhaeltnisse durch Auswertung geophysikalischer Temperaturmessungen in Trinkwasser- und Tiefbohrungen

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, W; Udluft, P [Lehr- und Forschungsbereich Hydrogeologie und Umwelt, Inst. fuer Geologie, Wuerzburg Univ. (Germany)

    1997-12-01

    The geothermal potential of northern Bavaria was investigated. Thermal water in the lower heat range may be used, e.g., for space heating, bath heating and agricultural purposes. Geophysical data were obtained from a number of drinking water wells with a depth of less than 150 m and a few deep wells of more than 150 m. The data are to serve as a decision aid for potential users of geothermal energy and reduce the exploration risk. (orig.) [Deutsch] Zielsetzung des Forschungsvorhabens ist die Bewertung des geothermischen Potentials Nordbayerns im Hinblick auf die Nutzung von Tiefenwasser zur Gewinnung von hydrothermaler Energie. Niedrigthermale Tiefenwaesser bieten sich z.B. als Energietraeger fuer Raumwaerme, Baederheizung and landwirtschaftliche Nutzung an. Die geothermischen Daten liegen in Form von geophysikalischen Temperaturmessungen aus zahlreichen Trinkwasserbohrungen mit weniger als 150 m Bohrtiefe und einigen Tiefbohrungen mit mehr als 150 m Bohrtiefe vor. Die Bewertung des geothermischen Potentials Nordbayerns soll als Planungsgrundlage fuer potentialle Erdwaermenutzer dienen und zu einer Minimierung des Explorationsrisikos beitragen. (orig.)

  2. Investigation of te development of the optimal process of fermentation of grass silage by means of a two-stage process; Untersuchungen zur Entwicklung eines optimalen Verfahrens der Vergaerung von Grassilage durch zweiphasige Prozessfuehrung

    Energy Technology Data Exchange (ETDEWEB)

    Zielonka, S.; Lemmer, A.; Oechsner, H.; Jungbluth, T. [Hohenheim Univ., Stuttgart (Germany). Landesanstalt fuer Landwirtschaftliches Maschinen- und Bauwesen, Baden-Wuerttemberg

    2007-07-01

    At present, mainly biogas plants with liquid manure as basis substrate are operated in the Federal Republic of Germany. Since the introduction of the Renewable Energy Resources Act in the year 2004, regenerating raw materials dominate as co-substrate beside organic residual substances. In the context of the composite material ''Biogas Crops network '', the mono fermentation is examined of grass silage in a two-phase procedure guidance using bioleaching. Thus the turnover rate of the energy stored in the organic mass is to be increased to methane. The focus of the investigations lies on the improvement of the hydrolysis achievement. Despite the high methane formation in the hydrolysis stage, in the thermophilic hydrolysis the highest degree of degradation of oTS and the highest yields of methane are received in the overall system.

  3. Study on singular radon releases from mining residues and the impact on the outdoor radon concentration; Untersuchungen zu singulaeren Radonfreisetzungen aus bergbaulichen Hinterlassenschaften und ihre Auswirkungen auf die Radonkonzentration im Freien

    Energy Technology Data Exchange (ETDEWEB)

    Kahnt, Rene; Martin, Mirko; Pinka, Jana

    2012-03-15

    The G.E.O.S. mbH was assigned by the Bundesamt fuer Strahlenschutz to perform time resolved measurements of the radon release and time and spatial resolved studies on the atmospheric dispersion dependent on the topographic and meteorological conditions in the area of Haiden. The report includes data on the radon release from mining residues at the site Johanngeorgenstadt and measurements in other areas.

  4. New studies on the synthesis and structural chemistry of polynary lithium and silver transition metal phosphates; Neue Untersuchungen zur Synthese und Strukturchemie von polynaeren Lithium- und Silber-Uebergangsmetallphosphaten

    Energy Technology Data Exchange (ETDEWEB)

    Mosymow, Emma

    2015-09-11

    In the course of this work extensive equilibrium studies were carried out in the four-system systems Li / M / P / O (M: Cr, Mn) in the search for new, powerful cathode materials for lithium ion batteries. The phosphates LiCr{sup II}{sub 4}(PO{sub 4}){sub 3}, NaCr{sup II}{sub 4}(PO{sub 4}){sub 3}, Li{sub 5}Cr{sup II}{sub 2}Cr{sup III}(PO{sub 4}){sub 4}, monoclines Li{sub 3}Cr{sub 2}(PO{sub 4}){sub 3}, Cr{sup II}{sub 5}Cr{sup III}{sub 2}(P{sub 2}O{sub 7}){sub 4} and LiMn{sup II}{sub 2}P{sub 3}O{sub 10} were obtained for the first time. The present work reports on their synthesis, crystallographic characterization and their spectroscopic and magnetic properties. The equilibrium studies in the Li / Cr / P / O system led to the elucidation of numerous phase relationships. For example, the coexistence regions LiCr{sub 4}(PO{sub 4}){sub 3} / Li{sub 5}Cr{sub 3}(PO{sub 4}){sub 4} / Cr{sub 2}O{sub 3} / CrP and Li{sub 9}Cr{sub 3}(PO{sub 4}){sub 3} / LiCrP{sub 2}O{sub 7} / CrP. The coexistence of some equilibrium phases such as lithium orthophosphate and lithium manganese(II) orthophosphate as well as lithium metaphosphate and manganese(III) metaphosphate were also investigated in the Li / Mn / P / O system. Furthermore, the de-intercalation behavior of silver manganese phosphates was investigated with the possibility of demonstrating metastable phosphates with manganese in oxidation states higher than 3+. In this case the four-substance system Ag / Mn / P / O with Mn(II) and Mn(III) was considered. The reaction conditions were adapted to those of the experiments in the corresponding lithium-containing systems. Within the scope of the equilibrium studies two new pyrophosphates AgMnP{sub 2}O{sub 7} and Ag{sub 1,6}Mn{sub 3}(P{sub 2}O{sub 7}){sub 2} were found and characterized. [German] Bei der Suche nach neuen, leistungsfaehigen Kathodenmaterialien fuer Lithiumionenbatterien wurden im Rahmen dieser Arbeit umfangreiche Gleichgewichtsuntersuchungen in den Vierstoffsystemen Li /M / P / O (M: Cr, Mn) durchgefuehrt. Hierbei wurden erstmalig die Phosphate LiCr{sup II}{sub 4}(PO{sub 4}){sub 3}, NaCr{sup II}{sub 4}(PO{sub 4}){sub 3}, Li{sub 5}Cr{sup II}{sub 2}Cr{sup III}(PO{sub 4}){sub 4}, monoklines Li{sub 3}Cr{sub 2}(PO{sub 4}){sub 3}, Cr{sup II}{sub 5}Cr{sup III}{sub 2}(P{sub 2}O{sub 7}){sub 4} und LiMn{sup II}{sub 2}P{sub 3}O{sub 10} erhalten. Ueber deren Synthese, kristallographische Charakterisierung sowie deren spektroskopische und magnetische Eigenschaften berichtet die vorliegende Arbeit. Die Gleichgewichtsuntersuchungen im System Li / Cr / P / O fuehrten zur Aufklaerung zahlreicher Phasenbeziehungen. So wurden statt der kristallchemisch naheliegenden Verbindungen ''LiCrPO{sub 4}'' und ''Li{sub 2}CrP{sub 2}O{sub 7}'' die Koexistenzgebiete LiCr{sub 4}(PO{sub 4}){sub 3} / Li{sub 5}Cr{sub 3}(PO{sub 4}){sub 4} / Cr{sub 2}O{sub 3} / CrP und Li{sub 9}Cr{sub 3}(P{sub 2}O{sub 7}){sub 3}(PO{sub 4}){sub 2} / Li{sub 3}Cr{sub 2}(PO{sub 4}){sub 3} / LiCrP{sub 2}O{sub 7} / CrP beobachtet. Im System Li / Mn / P / O wurde ebenfalls die Koexistenz einiger Gleichgewichtsphasen aufgeklaert, wie die von Lithium-orthophosphat und Lithium-mangan(II)-orthophosphat sowie von Lithium-metaphosphat und Mangan(III)-metaphosphat. Im Weiteren wurde das De-interkalationsverhalten von Silber-Mangan-phosphaten mit der Moeglichkeit zur Darstellung metastabiler Phosphate mit Mangan in Oxidationsstufen hoeher als 3+ untersucht. Hierbei wurde das Vierstoffsystem Ag / Mn / P / O mit Mn(II) und Mn(III) naeher betrachtet. Die Reaktionsbedingungen wurden an jene der Experimente in den entsprechenden Lithium enthaltenden Systemen angepasst. Im Rahmen der Gleichgewichtsuntersuchungen wurden zwei neue Pyrophosphate AgMnP{sub 2}O{sub 7} und Ag{sub 1,6}Mn{sub 3}(P{sub 2}O{sub 7}){sub 2} gefunden und charakterisiert.

  5. In vivo studies on the efficiency of irradiation with carbon ions at the syngeneic prostate carcinoma model R3327; In vivo Untersuchungen zur Wirksamkeit von Bestrahlungen mit Kohlenstoffionen am syngenen Prostatakarzinom Modell R3327

    Energy Technology Data Exchange (ETDEWEB)

    Glowa, Christin

    2013-07-01

    The aim of this study is to characterize differential effects after carbon ion ({sup 12}C) relative to photon irradiations in vivo in three different sublines of the syngeneic rat prostate adenocarcinoma (PCa) R3327 (AT1, HI, and H) as well as to identify tumor specific influence factors of the radiation response. Subcutaneous PCa tumor fragments in rats were irradiated with single (1 Fx) or split (2 Fx) doses of photons or carbon ions (75 keV/μ), respectively. Primary endpoint was local tumor control after 300 days. Based on dose-response curves, the TCD{sub 50{sup -}} values (dose at 50% tumor control probability) were used to calculate the relative biological effectiveness (RBE) of carbon ions. Additionally, potential carbon ion specific irradiation effects were studied. For this, in vivo tumor-physiological changes, structural and functional radiation- induced effects of gene expression as well as tumor subpopulations with tumor-inducing properties were investigated. For {sup 12}C- irradiations with 1 Fx or 2 Fx, the RBEs were 1.62 (H), 2.08 (HI) and 2.3 (AT1) and 1.9 (H), 2.1 (HI) and 2.67 (AT1), respectively. Isoeffective irradiation with photons and {sup 12}C- ions showed different kinetics of the radiation response. Magnetic resonance imaging (MRI) and histology showed a faster and stronger increase of tumor vessel permeability after {sup 12}C- irradiation compared to photons. After irradiation, DNA-repair mechanisms, immune system components and migration were induced, in contrast cell cycle progression, adhesion, angiogenesis, and the aerobic metabolism were downregulated. Especially, the kinetics of signaling cascades, apoptosis and stress-response were dependent on irradiation modality. In HI- and H-tumors CD24{sup +}/CD45{sup -} cells were identified as tumor inducing cells (TICs) in vivo. All three sublines were established under cell culture conditions to enable further molecular biological analyses. In conclusion, {sup 12}C- irradiation is especially effective for undifferentiated tumors, as the highest RBE was found for the radioresistant anaplastic AT1-tumor which decreased with increasing differentiation level. This is caused by the fact that TCD{sub 50{sup -}} values for carbon ions are less dependent on differentiation level as compared to photons. Carbon ions inactivated tumor cells and normal tissue as well as vessel structures faster and more effectively than photons. Radiation induced gene regulation affects similar functions for both radiation modalities, however, temporal characteristics vary, especially for the induction of DNA-repair mechanisms and survival signaling cascades. As CD24{sup +}/CD45{sup -} cells in H- and HI-tumors were identified as TICs, the distinct effect of photon- and {sup 12}C- irradiation on CD24- expression suggests a possible beam quality dependent differential impact on putative prostate cancer stem cells.

  6. Studies on the elements of optical and thermal energy transport through large components with transparent thermal insulation and shading; Untersuchungen der Grundlagen des optischen und thermischen Energietransportes bei grossflaechigen Komponenten mit transparenter Waermedaemmung und Verschattung

    Energy Technology Data Exchange (ETDEWEB)

    Platzer, W. [ed.; Apian-Bennewitz, P.; Kuhn, T.; Dill, F.U.; Wirth, H.; Wittwer, V.

    1997-11-28

    The report describes experimental and theoretical studies aiming at the comprehensive light-technical and energetic characterization of large, transparent construction elements including shading.- The two main measuring devices used for this purpose were a solar calorimeter for determining the total rate of energy passage, and a photogoniometer for measuring the bidirectional reflection and transmission properties of transparent construction elements and solar protection devices. The aims envisaged were to enhance measuring accuracy, create internationally comparable measuring conditions, and to integrate the experimental data into computer tools serving to evaluate construction elements in light-technical and energetic terms. (orig./GL) [Deutsch] In dem vorliegenden Sachbericht werden experimentelle und theoretische Arbeiten beschrieben, die auf eine umfassende lichttechnische und energetische Charakterisierung von grossflaechigen transparenten Bauteilen inklusive Sonnenschutz hinzielen. Die beiden wesentlichen Messvorrichtungen dazu sind ein Solarkalorimeter zur Bestimmung des Gesamtenergiedurchlassgrades und ein Photogoniometer zur Vermessung der bidirektionalen Reflexions- und Transmissionseigenschaften von transparenten Bauteilen und Sonnenschutzvorrichtungen. Ziele waren die Erhoehung der Messgenauigkeit, die Schaffung von international vergleichbaren Messbedingungen und die Integration der experimentellen Daten in Computerwerkzeuge, die der lichttechnischen und energetischen Bewertung von Bauteilen im Gebaeude dienen. (orig./GL)

  7. Microbial investigations in city soils of different use and heavy metal contamination with a view to characterizing its functional capability. Mikrobielle Untersuchungen in Stadtboeden unterschiedlicher Nutzung und Schwermetallbelastung zur Charakterisierung der Bodenfunktionalitaet

    Energy Technology Data Exchange (ETDEWEB)

    Weritz, N

    1990-11-20

    This work investigates the microbiological situation of city soils as an indicator of the soils' functional capability, and their impairment due to heavy metal pollution. It gives a survey of the literature (biological activities, influences on biological activities from heavy metals, microorganisms, bacteria, fungi, enzyme activities, CO{sub 2} respiration, mechanisms of resistance, simulation effects), points out the area of investigation and the investigated plots, and describes the method adapted. The latter includes sampling and sample storage, soil-chemical and soil-biological methods, laboratory experiments and statistical evaluation. The investigation results, which are reported in detail, cover, inter alia, the following: pH value, CaCO{sub 3} contents, cation exchange capacity, carbon content, catalase activity, urease activity and the relative comparison of microbial activity between the types of use. Results relating to heavy metal contents cover the total content and the effect of heavy metal pollutions on substrate-induced respiration, catalase activity and xylanase activity. (HWJ).

  8. Investigations of the microstructural stability of wrought Ni-(Fe)-based syperalloys for steam turbine rotor application beyond 700 C; Untersuchungen der Strukturstabilitaet von Ni-(Fe)-Basislegierungen fuer Rotorwellen in Dampfturbinen mit Arbeitstemperaturen ueber 700 C

    Energy Technology Data Exchange (ETDEWEB)

    Seliga, T.

    2005-07-01

    There is a continuous trend to improve the efficiency of modern power plants with steam turbine require operating steam temperature from 700 to 720 C. For substantial parts like turbine rotors and discs this means increased requirements on the high temperature resistance, which can not longer be fulfilled by the presently used steel. As new materials for the components, which are thermo-mechanically loaded, only Ni-based superalloys are suitable for their fabrication, structure stability and thermo-mechanical characteristics. With view on creep and creep crack growth resistance as suitable candidates in the context a DFG research project wrought Ni-based superalloy Waspaloy and Ni-Fe-based alloy Inconel 706 were selected, which exhibited different hardening mechanisms. Waspaloy is a {gamma}'-hardened material with small portion of carbides on the grain boundaries. Inconel 706 is a particle hardened alloy with a very complex microstructure, it consists of {gamma}', {gamma}{sup ''}-particle, {eta}-phase und carbides. Concerning to their castability, forgeability, creep and creep crack growth and microstructural stability these candidate materials have been investigated and modelled. The knowledge about their long time stability of the microstructure, castability, forgeability and mechanical properties leads to the two new modification (Waspaloy{yields}DT750 and Inconel 706{yields}DT706). The modification of the Waspaloy to DT 750 served better castability (elimination of the Freckle formation). An improvement of the long-term stability of the microstructure was not necessary, by a changed heat treatment was reached a homogeneous, monomodale {gamma}'-particle distribution. The modification of Inconel 706 to DT 706 served to stabilize the {gamma}'-phase and to reduce of the {gamma}{sup ''} phase without suppressing the cellular {eta}-phase colonies on the grain boundaries. This work presents the test results for the structural long-term stability of the mentioned materials and their modifications. In this paper influences of heat treatments and thermal exposure on the microstructure and consequences for the mechanical behaviour will be discussed. (orig.)

  9. The impacts of climate change on soils. Investigations of impacts of climate change on soil erosion by water; Wirkungen der Klimaaenderungen auf die Boeden. Untersuchungen zu Auswirkungen des Klimawandels auf die Bodenerosion durch Wasser

    Energy Technology Data Exchange (ETDEWEB)

    Wurbs, Daniel [Geoflux GbR, Halle (Saale) (Germany); Steininger, Michael [Mitteldeutsches Institut fuer angewandte Standortkunde und Bodenschutz (MISB), Halle (Saale) (Germany)

    2011-03-15

    Climate forecasts regarding the 21st century raise expectations in soil erosion growth mainly due to changes in heavy precipitation characteristics and ground cover in line with the adaptation of the crop growing season to future climatic conditions. The aim of this study initiated by the Federal Environmental Agency was, to examine the impacts of climate change on soil erosion by water in Germany using data calculated by the statistical climate model WETTREG. Soil erosion by water was estimated following an USLE approach implemented in ABAGFlux and TerraFlux with focus on the usage-based erosion potential in German agricultural areas. In the 2nd project phase the USLE R factor was recalculated for the recent (1971-2000) and future climate periods (2011-2040, 2041-2070, 2071-2100) using statistical methods such as the peak over threshold method. Furthermore the climate-induced change of the C-factor was analyzed with respect to changes of culture periods, ground cover and the monthly R factor. Scenarios regarding future percentage of conservation tillage systems as also the potential and usage-based soil erosion for these four climate periods have been modelled. The results underline a requirement to differentiate the view on temporal and spatial development of R factors and potential soil erosion. There are minor changes between 2011 and 2040 followed by an increased erosion hazard in western and north-western Germany after 2041 while eastern and southern Germany face a downward trend of R factors, derived using WETTREG data of a reference period 1971 to 2000. Between 2071 and 2100 potential soil erosion rises with R factors above the actual state due to more heavy rain falls nearly all over Germany. The resulting temporal offset of culture periods and the monthly distribution of the R factor cause rising C factors in all time periods as also increasing usage-based soil erosion hazard in Germany. This study shows that soil erosion exists in Germany. The problem gains more and more importance due to climate change and calls for action strategies against soil erosion, especially extended conservation tillage systems in core regions of soil erosion hazards. (orig.)

  10. Study of the influence of the cool-down speed at the dew-point level of the readings of the dew-point temperature; Untersuchungen zum Einfluss der Abkuehlgeschwindigkeit am Taupunktspiegel auf Messwerte der Taupunkttemperatur

    Energy Technology Data Exchange (ETDEWEB)

    Bogoya, J.D. [Univ. Nacional de Colombia (Colombia); Mueller, C. [Inst. fuer Technische Thermodynamik und Kaeltetechnik, Univ. Karlsruhe (Germany); Oellrich, L.R. [Inst. fuer Technische Thermodynamik und Kaeltetechnik, Univ. Karlsruhe (Germany)

    1995-09-01

    The impact of the cool-down speed at the dew-point mirror on the behaviour of the readings of dew-point temperature of nitrogen-water mixtures has been investigated with the focus on mixtures with low water content. For this purpose a commercial dew-point mirror was equipped with a refrigerating device in order to cool the mirror surface. Moreover a data acquisition system was connected for the measurement of the rates of cooling. Via a control valve in the refrigerant cycle rates of cooling of about 1 to 35 C/min could be chosen. With a saturation system saturation conditions could be varied in the pressure range from 5 to 90 bar and in the temperature range from +10 to -15 C. The measuring instrument was continuously supplied with the gas mixture. The measurements were carried out under constant volume flow of the carrier gas. The results are discussed. (orig.) [Deutsch] Der Einfluss der Abkuehlgeschwindigkeit am Taupunktspiegel auf die Lage der Messwerte der Taupunkttemperaturen von Stickstoff/Wasser-Gemischen wurde speziell im Bereich niedriger Wassergehalte untersucht. Dazu wurde ein kommerzieller Taupunktspiegel zur Kuehlung der Spiegeloberflaeche mit einer Kaeltemaschine ausgestattet und eine Messwerterfassung, mit der Abkuehlgeschwindigkeiten ermittelt werden konnte, angeschlossen. Ueber ein Regelventil im Kaeltemittelkreislauf konnten Abkuehlgeschwindigkeiten von ca. 1 bis 35 C/min eingestellt werden. Ueber eine Saettigungsanlage wurden Saettigungsbedingungen im Druckbereich von 5 bis 90 bar und im Temperaturbereich von +10 bis -15 C variiert und das Messgeraet kontinuierlich mit Gasgemisch versorgt. Die Messungen wurden bei konstantem Volumenstrom des Traegergases durchgefuehrt. Die Messergebisse werden diskutiert. (orig.)

  11. Investigations on chemical-physical conditioning of ashes from the incineration of sewage sludge to deposit on surface landfill site; Untersuchungen zur Chemisch-Physikalischen Behandlung von Klaerschlammverbrennungsasche zur Ablagerung auf oberirdischen Deponien

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, O.; Becker, A. [Technische Univ. Kaiserslautern (Germany). Fachgebiet Bodenmechanik und Grundbau; Scherer, G. [TERRAG Service und Vertrieb GmbH, Homburg (Germany)

    2007-06-15

    Depositing of ashes from the incineration of sewage sludge on landfill is possible after conditioning or within appropriate boxes. The partial high content of chromate- and dichromate- (chrome VI) concentration in the eluate of these slags can cause some difficulties. Presently, disposal of such slags is accomplished in underground spaces. Taking into account the provisions of national laws, possibility is limited. Therefore investigations on deposing of conditioned slags on surface landfills are of growing importance. The binders added to condition the incineration slags were chosen to assess the chemical change of hexavalent chrome (chrome VI) to indissoluble chrome (chrome III). Cement, SAV-residues as well as fly ash were taken as binders. The investigations presented refer to results on mechanical behaviour of conditioned slags. Emphasis is placed on the time-dependent behaviour of strength as well as on water permeability. Several cylindrical samples made by different compounds were tested within a period of about 112 days. Requirements with respect to strength were met within a few days. Demands on the eluate-criteria need additional investigations. (orig.)

  12. Bone mineral density in renal osteodystrophy: Comparison of dual energy X-ray absorptiometry and quantitative computed tomography. Vergleichende Untersuchungen mit der quantitativen Computertomographie und der Dual-Energy-X-Ray-Absorptiometrie zur Knochendichte bei renaler Osteopathie

    Energy Technology Data Exchange (ETDEWEB)

    Funke, M.; Maeurer, J.; Grabbe, E. (Abt. Roentgendiagnostik, Klinikum, Goettingen Univ. (Germany)); Scheler, F. (Abt. Nephrologie und Rheumatologie, Klinikum, Goettingen Univ. (Germany))

    1992-08-01

    Measurements of bone density were carried out in 25 patients on dialysis for terminal renal insufficiency, using quantitative computed tomography (QCT) and dual energy X-ray absorptiometry (DXA). Unlike in subjects with normal kidneys, there was no significant correlation between these methods in this series. Ten patients showed an increase in bone density of the vertebral spongiosa on QCT measurements, which was interpreted as due to osteosclerotic bone changes in renal osteopathy. QCT showed advantages over DXA in demonstrating these changes. (orig.).

  13. Investigations of the oxidation-induced service life of chromium steels for high temperature fuel cell application (SOFC); Untersuchungen zur oxidationsbedingten Lebensdauer von Chromstaehlen fuer die Anwendung in der Hochtemperaturbrennstoffzelle (SOFC)

    Energy Technology Data Exchange (ETDEWEB)

    Ertl, S.T.

    2006-08-17

    The increasing energy consumption of future automobiles should be covered by a solid oxide fuel cell (SOFC) used as an additional energy supply (auxiliary power unit). The application of a SOFC with about 5 kW power in cars requires small size, low weight and an economic fabrication. To achieve this goal the interconnector and the metallic anode substrate (depending on an alternative concept of construction) should be manufactured out of thin Crofer22APU, a high chromium ferritic steel. The scale formation mechanisms on Crofer22APU sheets, wires and powder metallurgical produced foils of different thicknesses were investigated in several atmospheres of water vapour/hydrogen at 800 and 900 C, simulating the anode conditions. For scale characterization a number of conventional analysis techniques such as optical metallography, scanning electron microscopy and X-ray diffraction were used in combination with deflection testing in monofacial oxidation and two-stage oxidation studies using {sup 18}O and H{sub 2} {sup 18}O tracer. With these results a theoretical model for the determination of lifetime was developed for Crofer22APU components in simulated anode gas. It was found that the lifetime at a given temperature depends not only on the surface-to-volume ratio, but also on the geometry of the component (e.g. sheet or wire). The critical Cr content required for breakaway oxidation depends on microcrack formation in the surface oxide scale, which occurs on ridges of a sheet during thermal cycling. The development of a metallic interconnector and a metallic anode substrate requires measures to avoid interdiffusion between the alloy and the bordering nickel-YSZ (yttrium stabilized zirconia) cermet of the anode, or depending on the conception of the stack, the bordering nickel-YSZ cermet of the anode functional layer. Therefore the suitability of preoxidation layers after different preoxidation conditions was tested. It was found that the inhibition of the interdiffusion depends not only on the preoxidation conditions, but also on the conditions under which the nickel layer was applied. (orig.)

  14. Investigating the global transport of trace species and the stratoshere-troposphere-exchange with the Lagrangian model ECHAM4/ATTILA; Untersuchungen zum globalen Spurenstofftransport und Stratosphaeren-Troposphaeren-Austausch mit dem Lagrangeschen Modell ECHAM4/ATTILA

    Energy Technology Data Exchange (ETDEWEB)

    Reithmeier, C.

    2001-07-01

    Investigating the chemical composition of the atmosphere and its influence on the global climate involves a large number of trace species. Therefore, the Lagrangian transport scheme ATTILA has been developed in this thesis. ATTILA runs online in the general circulation model ECHAM4 and, thus, can be used efficiently for studies involving many tracers. The present study discusses the problems which arise when applying Lagrangian methods on long range and global scale, and describes in detail the solutions developed for ATTILA. Transport experiments with both short-lived and long-lived tracers clearly show that ATTILA is numerically much less diffusive than the operational semi-Lagrangian scheme of ECHAM. It could be shown that the enhanced meridional transport in the tropopause region and the overestimated downward flux through the tropopause in ECHAM are rather due to the numerical properties of the semi-Lagrangian scheme than due to an incorrect circulation. Furthermore, the stratospheric dynamics has been investigated in this study by analysing trajectories and by calculating age spectra and mass fluxes. (orig.)

  15. The effect of organolead and -tin compounds on signal transduction in vitro: Investigations on the cytosolic free calcium concentration; Der Einfluss von organischen Blei- und Zinnverbindungen auf die Signaltransduktion in vitro: Untersuchungen zur Veraenderung der zytosolischen freien Calciumkonzentration

    Energy Technology Data Exchange (ETDEWEB)

    Ade, T.

    1996-03-01

    The cellular effects of organolead and -tin compounds are not yet precisely understood. However, on the basis of their immuno- and neurotoxicity it is most likely that these substances interfere with cellular signal transduction. For this reason the effect on cytosolic free calcium concentration was investigated in this study. The organometals used induce a persistent increase in cytosolic free calcium concentration in human leukaemia HL-60 cells as well as in neuroblastoma NG-108-15 cells. Studies of the mechanism of the organometal effect with EGTA and calcium channel blockers revealed that an influx of calcium from the extracellular space is responsible for the organometal-induced calcium elevation in HL-60 cells. The effect of the investigated lead compounds and tributyltin is due to calcium channel opening in the plasma membrane. The same is true for the NG108-15 cells. Activation of distinct receptor-mediated signal transduction is not the reason for channel opening. The regulation of cytosolic free calcium concentration was affected by inhibition of plasmamembrane Ca{sup 2+}-ATPases as well as by disturbance of other ion gradients. A consequence of the organometal effect on the cytosolic calcium concentration is the activation of a cPLA{sub 2} and perhaps the induction of apoptosis. These results contribute towards the understanding of biochemical mechanisms causing the injury of vells by organometals. (orig.) [Deutsch] Die zellulaeren Wirkungsmechanismen organischer Blei- und Zinnverbindungen sind zum grossen Teil nicht verstanden. Die immuno- und neurotoxischen Effekte dieser Xenobiotika lassen jedoch die Beeinflussung der Signalwege in den Zellen vermuten. Daher lag der Schwerpunkt dieser Arbeit in der Untersuchung der Signaluebertragungswege und der damit verbundenen Regulation des Calciums. Sowohl in immunkompetenten Zellen (HL-60) wie auch in neuronalen Zellen (NG108-15) induzierten die untersuchten Organometalle eine persistente Erhoehung der zytosolischen freien Calciumkonzentration. Mechanistische Studien mit EGTA, dem Calciumkanalblocker Nickel und der Untersuchung der intrazellulaeren Speicher in den HL-60 Zellen ergaben, dass ausschliesslich das extrazellulaere Calcium fuer den organometall-induzierten Anstieg der zytosolischen freien Calciumkonzentration verantworlich ist. Die Bleiverbindungen sowie das Tributylzinn fuehrten zur Oeffnung von Calciumkanaelen in der Plasmamembran. Die Experimente mit den NG108-15 Zellen belegen diese Ergebnisse. Durch den Einsatz von Mangan (Mn{sup 2+}) und Verapamil wurde nachgewiesen, dass der von Triethylblei und Tributylzinn induzierte Calciuminflux auch hier durch Calciumkanaele erfolgt. Waehrend bestimmte rezeptor-aktivierte Signalwege durch die Organometalle nicht induziert werden, konnte die Hemmung von Ca{sup 2+}-ATPasen ebenfalls beschrieben werden. Die Wirkung der Blei- und Zinnverbindungen resultierte in calcium-vermittelten Folgereaktionen, wie die Aktivierung der cPLA{sub 2} oder eventuell der Induktion der Apoptose. Die durch die Metallverbindungen veraenderte Regulation der zytosolischen freien Calciumkonzentration war auch von anderen Ionengradienten an der Plasmamembran, wie Na{sup +}, Cl{sup -}, oder H{sup +} abhaengig. Mit dieser Arbeit wurde ein Beitrag zur Aufklaerung der biochemischen Mechanismen und zum Verstaendnis der zellschaedigenden Wirkung von Organometallen geleistet. (orig.)

  16. Study into the status of co-combustion of sewage sludge, biomass and household refuse in coal-fired power stations. Final report; Untersuchungen zum Stand der Mitverbrennung von Klaerschlamm, Hausmuell und Biomasse in Kohlekraftwerken. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Hein, K.R.G.; Spliethoff, H.; Scheurer, W. [Stuttgart Univ. (Germany). Inst. fuer Verfahrenstechnik und Dampfkesselwesen; Seifert, H.; Richers, U. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Inst. fuer technische Chemie - Thermische Abfallbehandlung

    2000-03-01

    The co-combustion of wastes in power stations is an additional option for the thermal treatment of certain waste materials and thus for complying with the specifications of the German TA-Siedlungsabfall (technical directive on disposal of municipal solid waste). The present investigation compiles the status of knowledge about co-combustion of sewage sludge, biomass and selected waste materials in coal-fired power stations. The results are meant to provide extensive assistance to evaluate the processes and thus to contribute to sort out uncertainties, both on the part of power plant operators and of the authorities. Based on the information acquired, the report shall point out the gaps in knowledge, the further need for research and development and the need for action conerning the authorities. By enquiries at disposal enterprises, power station operators as well as authorities, the literature work was completed and a comprehensive view of the current situation in Germany elaborated. The report points out the legal conditions of co-combustion and supplementary fuel potentials, presents the process engineering of co-combustion, and examines the obstacles encountered during the technical conversion, the environmental questions, and the potential for co-combustion of the above materials in existing power stations. The electrical power sector is subject to strong changes due to the liberalisation of the energy market. The pressure on costs has increased and the periods available for planning are shorter. On the one hand, this arouses an increased interest in co-combustion of waste materials because of possible additional payments for the wastes. On the other hand, however, initiatives in this respect are counteracted by high investments costs necessary for the introduction of co-combustion with the existing high environmental standards. What is more, the competitive situation reduces the exchange of experience between the power station operators. Co-combustion of sewage sludge in coal-fired power stations is state of the art and carried out at various sites. It can be expected that co-combustion of waste wood will be introduced in the future on a wider scale. For both supplementary fuels, there was a fuel market already established, or it could build itself on available structures. The practice of these projects brought about ample experience with the supply of the supplementary fuels and the effects of co-combustion on system operation. The knowledge thus gained can be used when further supplementary fuels shall be introduced in the large power-station park of Germany. The facts and data compiled point out in addition where possibilities for improvement exists and which subjects require further investigation. (orig.) [German] Die Mitverbrennung von Abfaellen in Kraftwerken bietet sich als eine zusaetzliche Option zur thermischen Behandlung bestimmter Abfallstoffe und damit zur Einhaltung der Vorgaben der TA-Siedlungsabfall an. In der vorliegenden Untersuchung ist der Wissensstand zur Mitverbrennung in Kohlekraftwerken fuer Klaerschlamm, Biomasse und ausgewaehlte Abfallstoffe zusammengefasst. Die Ergebnisse sollen eine umfangreiche Hilfe zur Beurteilung der Verfahren zur Verfuegung stellen, um so einen Beitrag zur Beseitigung von Unsicherheiten, sowohl bei Anlagenbetreibern als auch auf der Seite der Aufsichtsbehoerden, zu leisten. Ausserdem sollen mit Hilfe der erarbeiteten Erkenntnisse bestehende Wissensluecken, der notwendige Forschungs- und Entwicklungsbedarf und der Handlungsbedarf des Gesetzgebers aufgezeigt werden. Durch direkte Recherche bei Entsorgungsunternehmen, den Kraftwerksbetreibern und auch den Genehmigungs- und Aufsichtsbehoerden wurde die Literaturarbeit ergaenzt und ein umfassendes Bild der aktuellen Situation in Deutschland erarbeitet. Es werden die gesetzlichen Rahmenbedingungen der Mitverbrennung und Zusatzbrennstoffpotentiale aufgezeigt. Die verfahrenstechnische Verwirklichung der Mitverbrennung wird dargestellt, sowie Hemnisse bei der technischen Umsetzung, umweltrelevante Fragestellungen und das Mitverbrennungspotential der genannten Stoffe in bestehenden Kraftwerken untersucht. Der Kraftwerkssektor ist auf Grund der Liberalisierung des Strommarktes einem starken Wandel unterzogen. Der Kostendruck ist stark gestiegen und die Zeitraeume, in denen geplant werden kann, sind verkuerzt. Dies fuehrt einerseits wegen moeglicher Zuzahlungen zu einem erhoehten Interesse an der Mitverbrennung von Abfallstoffen. Andererseits sind hohe Investitionskosten, die bei der Umsetzung der Mitverbrennung unter bestehenden Umweltstandards anfallen koennen, aber auch ein Hemmnis. Hinzu kommt, dass auf Grund der Konkurrenzsituation der Erfahrungsaustausch zwischen den Kraftwerksbetreibern eingeschraenkt ist. Die Mitverbrennung in Kohlekraftwerken ist fuer Klaerschlamm Stand der Technik und an verschiedenen Standorten verwirklicht. (orig.)(abstract truncated)

  17. Investigations of atmospheric input of polychlorinated dibenzo-p-dioxins and dibenzofurans into pasture. Pt. 2. Appendix. Final report; Untersuchungen des atmosphaerischen Eintrags polychlorierter Dibenzo-p-dioxine und Dibenzofurane in Futterpflanzen. T. 2. Anhang. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    McLachlan, M S; Welsch-Pausch, K; Koemp, P

    1998-07-01

    Introduction of PCDD/Fs into the agricultural food chain `atmosphere - fodder - cattle - cows` milk/beef - human` plays a major role in human exposure. The aim of this study was to establish a quantitative relationship between PCDD/Fs immissions and fodder concentrations. The identification of the most important atmospheric pathway of PCDD/F into greenland cultures was conducted under near natural conditions in a combined field/glasshouse experiment. It was found that for the Cl{sub 4-6}DD/Fs dry gaseous and for the Cl{sub 7/8}DD/Fs dry particle-bound deposition was the primary mechanism of uptake. A further greenhouse experiment showed that there is an isomere-unspecific photodegradation of PCDD/Fs on plant surfaces. Dry gaseous deposition, which is the major pathway of atmospheric deposition for the less chlorinated toxicological relevant PCDD/Fs, can be understood as a partitioning process between the gas phase of the atmosphere and the vegetation. Experiments investigating this topic were conducted in the laboratory using PCBs as model substances for the PCDD/Fs. Important knowledge was gained with regard to plant/air partitioning, their dependence on temperature and plant species, the kinetics and reversibility of the process. No partitioning equilibrium between the vegetation and the gas phase of the atmosphere was approached for the PCDD/Fs. The accumulation of PCDD/Fs in agricultural greenland was therefore controlled by a gaseous deposition velocity. In two typical German agricultural regions representative gaseous and particle-bound deposition velocities were determined, which were all in all quite constant and independent of the different exposure conditions. All results from this study were incorporated into a mathematical model of the accumulation of PCDD/Fs and PCBs in greenland. Based on air concentration, plant species composition and growth, temperature and physical-chemical properties of the chemical the model is able to predict the concentration of a chemical in the plants as a function of time. A validation of this model for the less chlorinated PCBs showed, that the measured plant/air-partitioning and the corresponding components of the model can be extrapolated to environmental conditions. This model summarizes the results of this study and provides a valuable tool in understanding the enrichment of semivolatile lipophilic organic compounds in agricultural plants. (orig.)

  18. Integrated project: Microbiological and physiological studies on the presence of residual concentrations in mineral-oil-contaminated soils after rehabilitation. Final report. Pt. 2; Mikrobiologische und physiologische Untersuchungen zur Frage der Restkonzentration bei der Sanierung mineraloelkontaminierter Boeden. Abschlussbericht. T. 2

    Energy Technology Data Exchange (ETDEWEB)

    Miethe, D.; Riis, V.; Stimming, M.

    1996-01-04

    It has been known for a long time that microorganisms are able to utilise mineral oils. Today various methods are practised which exploit autochthonous microorganisms` ability to utilise mineral oils. The main problem of microbial decomposition of hydrocarbons is that mineral oil residues remain. The aim of the present research project was therefore to determine the limits of the metabolisability of the substrate and find out why residues remain. Mineral oils and residual fractions differ markedly in their decomposability. Intermediate distillates are easily decomposed to a degree of 95-97% by well-adapted consorts. For high-boiling mineral oils (bp>400 C) the degree of decomposition is approx. 60%. Extracts from contaminated sites range from 40 to 60% in their degree of decomposability. The incomplete microbial decomposition of mineral oils is mainly due to their structure. There remain chemically and thermally extremely, inert hydrocarbons (mainly aliphatic and aromatic fused-ring systems) which are either hardly metabolisable or not at all. An important factor in soils or at other contaminated sites is that some of the substrate is not available because it is bound to the matrix thus increasing the proportion of residue. The next task after examining and presenting the causes of incomplete decomposition is to minimise residual mineral oil concentrations remaining after microbial decomposition. Here the use of special surfactants or of auxiliary substrates could point a way. Project applications to this end have already been submitted to the Federal Ministry for Education and Research. (orig.) [Deutsch] Dass Mikroorganismen in der Lage sind, Mineraloele zu verwerten, ist seit langem bekannt. Verfahren, die das Potential autochthoner Mikroorganismen zur Verwertung von Mineraloelen nutzen sind Praxis. Hauptproblem beim mikrobiellen Abbau der Kohlenwasserstoffe ist das Verbleiben von Mineraloelresten. Das Ziel des Forschungsvorhabens war die Ermittlung der Grenzen der Metabolisierbarkeit und die Aufklaerung der Ursachen fuer das Verbleiben dieser Reste. In ihrer Abbaubarkeit unterscheiden sich die untersuchten Mineraloele und Restfraktionen deutlich. Mittlere Destillate koennen problemlos mit adaptierten Konsortien zu 95-97% abgebaut werden. Bei hoehersiedenden Mineraloelen (Kp>400 C) betraegt der Abbaugrad ca. 60%. Abbaugrade von 40-60% weisen die Extrakte aus Altlasten auf. Der unvollstaendige mikrobielle Abbau von Mineraloelen ist hauptsaechlich strukturbedingt. Es verbleiben chemisch und thermisch aeusserst stabile Kohlenwasserstoffe (vorwiegend aliphatische und aromatische kondensierte Ringsysteme), die nicht oder sehr schwer metabolisierbar sind. In Boeden/Altlasten spielt auch die matrixbedingte Nichtverfuegbarkeit eine wesentliche Rolle und erhoeht den Anteil des Restes. Nach Untersuchung und Darlegung der Ursachen fuer den unvollstaendigen Abbau steht die Aufgabe der Minimierung der Restkonzentrationen beim Mineraloelabbau. Sowohl spezielle Tenside als auch Hilfssubstrate koennten den Weg zeigen. Projekte dazu sind beim BMBF eingereicht. (orig.)

  19. Investigation of the behaviour of solid acid catalysts for acylations and cyanisations of aromatics. Final report; Untersuchungen zur Wirkungsweise von festen sauren Katalysatoren bei Acylierungen und Cyanierungen von Aromaten. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Kemnitz, E.

    2002-01-01

    The present state of the art in the field of FRIEDEL-CRAFTS-ACYLATIONS is characterized by the application of homogenous catalysts (at least stochiometric amounts) like AlCl{sub 3} or FeCl{sub 3}. Problems arising from this application are corrosions, difficult product separations from the catalyst and the origin of acid waste water. Hence, the aim of this project was the development of suitable solid catalysts which overcome the problems ascribed above. Sulfated zirconia (SZ) was found to be an excellent solid Br.o/nsted-acid to be used especially in their aerogel or cryogel form. Thus with this catalyst system, in the benzoylation of anisol nearly 100% conversion may be achieved. In this way it could be proved, that with SZ a solid Br.o/nsted-acid might be available which gives reasonable hope to substitute in a near future, at least for some reactions, the classical homogeneous catalysts and to overcome their problems in use. (orig.)

  20. The free-piston linear generator. Theoretical engine analysis and experimental investigations on gas spring subsystems; Der Freikolbenlineargenerator. Theoretische Betrachtungen des Gesamtsystems und experimentelle Untersuchungen zum Teilsystem der Gasfeder

    Energy Technology Data Exchange (ETDEWEB)

    Pohl, S.E.

    2007-07-01

    The thesis presents the modeling and simulation of a novel development in the field of free-piston engines and the experimental investigation of controllable gas springs. The free-piston linear alternator proposed by the German Aerospace Center (DLR) - Institute of Vehicle Concepts (IFK) combines a two stroke combustion engine with a linear alternator. An adjustable gas spring is used to reset the piston assembly. The engine is designed to enable new degrees of freedom for advanced optimization of the combustion process. In contrast to conventional crankshaft engines, the free-piston design offers mainly two degrees of freedom to improve engine performance: a variable piston stroke and a variable compression ratio. These key features allow for designing a combustion process with low emissions. The variable stroke and variable compression ratio can be used to optimize the combustion process for part load conditions. The goal is to achieve a compact electric power engine with high efficiency and reduced emissions. The free-piston linear alternator aims towards automotive application as auxiliary power unit and as power generator in hybrid electric vehicles. To study the features of free-piston engines this thesis provides a Modelica library containing basic and advanced component models. Control strategies are developed and the dynamic system behavior is characterized through parameter variations. The second part of the thesis examines two gas spring concepts allowing adjustable spring constants during engine operation. The gas spring concepts are theoretically and experimentally investigated. The experimental data is discussed and compared to simulation results. (orig.)

  1. Comparison of the radiation dose from cone beam computed tomography and multidetector computed tomography in examinations of the hand; Vergleich der Strahlendosis von Cone-Beam Computertomografie und Multidetektor Computertomografie in Untersuchungen der Hand

    Energy Technology Data Exchange (ETDEWEB)

    Neubauer, J.; Neubauer, C.; Gerstmair, A.; Krauss, T.; Kotter, E.; Langer, M. [University Medical Center Freiburg (Germany). Dept. of Radiology; Reising, K. [University Medical Center Freiburg (Germany). Dept. of Orthopedics and Trauma Surgery; Zajonc, H. [University Medical Center Freiburg (Germany). Dept. of Plastic and Hand Surgery; Fiebich, M.; Voigt, J. [University of Applied Sciences, Giessen (Germany). Inst. of Medical Physics and Radiation Protection

    2016-05-15

    Comparison of radiation dose of cone beam computed tomography (CBCT) and multidetector computed tomography (MDCT) in examinations of the hand. Dose calculations were carried out by means of Monte Carlo simulations in MDCT and CBCT. A corpse hand was examined in a 320-row MDCT scanner and a dedicated extremities CBCT scanner with standard protocols and multiple low-dose protocols. The image quality of the examinations was evaluated by 5 investigators using a Likert scale from 1 (very good) to 5 (very poor) regarding depiction of cortical bone, cancellous bone, joint surfaces, soft tissues and artifacts. For a sum of ratings of all structures < 50 a good overall image quality was expected. The studies with at least good overall image quality were compared with respect to the dose. The dose of the standard examination was 13.21 (12.96 to 13.46 CI) mGy in MDCT and 7.15 (6.99 to 7.30 CI) mGy in CBCT. The lowest dose in a study with good overall image quality was 4.54 (4.43 to 4.64 CI) mGy in MDCT and 5.72 (5.59 to 5.85 CI) mGy in CBCT. Although the dose of the standard protocols in the CBCT is lower than in the MDCT, the MDCT can realize a good overall image quality at a lower dose than the CBCT. Dose optimization of CT examination protocols for the hand is useful in both modalities, the MDCT has an even greater potential for optimization.

  2. Experimental and numerical investigations on the applicability of local approach methods on the warm prestress effect; Experimentelle und numerische Untersuchungen zur Anwendbarkeit von Local-Approach-Ansaetzen auf WPS-Effekt

    Energy Technology Data Exchange (ETDEWEB)

    Roos, E; Elsaesser, K [Stuttgart Univ. (Germany). Staatliche Materialpruefungsanstalt

    1998-11-01

    The three materials 10 MnMoNi 5 5, as a welded specimen, 22 NiMoCr 3 7 mod., and 17 MoV 8 4 mod. have been examined as a part of project work. The major known influencing variables with respect to the WPS effect are materials hardening, crack tip blunting, and the developing residual stress field. The project task was to investigate to what extent the finite element method will be able to describe these influencing variables. Using the damaging model of Rousselier it is possible to simulate the processes during warm prestressing at upper-shelf toughness while taking into account the crack growth. Using the parameter derived with the Beremin model with notched specimens and applying these to pre-cracked specimens will not yield accurate results describing the fracture toughness in the area affected by embrittlement. (orig./CB) [Deutsch] Im Rahmen des Forschungsprojektes wurden die drei Werkstoffe 10 MnMoNi 5 5 formgeschweisst, 22 NiMoCr 3 7 mod. und 17 MoV 8 4 mod. untersucht. Als hauptsaechliche Einflussgroessen fuer den WPS-Effekt gelten die Werkstoffverfestigung, die Abstumpfung der Rissspitze (Blunting), sowie das sich ausbildende Eigenspannungsfeld. Es wurde untersucht, inwieweit es mit Hilfe der Methode der Finiten Elemente moeglich ist, die einzelnen Einflussgroessen zu beschreiben. Mit Hilfe des Schaedigungsmodelles von Rousselier koennen die Vorgaenge beim Warmvorbelasten in der Zaehigkeitshochlage auch unter Beruecksichtigung von Risswachstum simuliert werden. Bei Verwendung der an gekerbten Proben ermittelten Parameter des Beremin-Modelles und deren Uebertragung auf angerissene Proben wird die Bruchzaehigkeit im Sproedbruchgebiet nicht zutreffend berechnet. (orig./MM)

  3. Investigations into the influence of airborne pollutants on the metabolism of secondary phenolic substances and amino acids. Untersuchungen ueber den Einfluss von Luftschadstoffen auf den Stoffwechsel von phenolischen Sekundaerstoffen und Aminosaeuren

    Energy Technology Data Exchange (ETDEWEB)

    Strack, D.

    1988-10-01

    Quantitative analyses of secondary phenols, free amino acids, and of the enzyme activities arginase and asparaginase were carried out on spruce needles from six different forest sites in North-Rhine Westphalia. In addition, the effects of ozone on spruce aged seven to eight years were investigated. The aim of this was to find out whether there is a correlation between the phenol and amino acid metabolism and the damage rate in older spruce (31 to 60 years) and in younger spruce exposed to ozone. No correlation could be established with a single exception: In one site, the free amino acid pattern showed a 10-fold increase of arginine and an accumulation of ornithine and lysine. This indicates a disturbed nitrogen metabolism, in particular a stimulation of the urea cycle, which may be caused by anthropogenic over fertilizing with nitrogen. The findings for the spruce exposed to ozone indicate a more complex effect on the needle metabolism, which affects both the phenol metabolism (strong decrease of the catechine concentration) and the amino acid metabolism (increase of the alanine concentration). This may be caused by damaged membranes (i.e. higher permeability accompanied by sensitive changes in the metabolic compartmenting) or by a potential increase of transaminase activities. (orig./MG).

  4. Effects of airplane emissions on the composition of the atmosphere: Investigations using a mesoscale chemical transport model; Der Einfluss von Flugzeugabgasen auf die Zusammensetzung der Atmosphaere: Untersuchungen mit einem mesoskaligen Chemie-Transport-Modell

    Energy Technology Data Exchange (ETDEWEB)

    Lippert, E

    1997-12-31

    In the present work the impact of aircraft emissions on the atmospheric composition is studied using a mesoscale chemistry transport model. To simulate the impact of aircraft exhausts several modifications on the EURAD model system have been performed. The upper boundary of the model has been extended from 100 hPa up to 10 hPa. The vertical resolution of the model has been refined especially in tropopause altitudes extending the number of model layers from 15 to 29. Additionally the initialization and the treatment of the boundary conditions has been improved by coupling the trace gas concentration fields with the individual meteorological situation. To guarantee an adequate representation of the atmospheric chemistry the chemical mechanism CHEST has been developed and implemented into the chemistry transport model. CHEST treats the most important chemical processes of the troposphere and lower stratosphere. In the frame of the present work sensitivity studies with a box model and with the threedimensional chemistry transport model have been performed to investigate the impact of aircraft emissions upon the atmosphere. (KW) [Deutsch] In der vorliegenden Arbeit werden die Auswirkungen der Flugzeugemissionen auf die Zusammensetzung der Atmosphaere mit Hilfe eines mesoskaligen Chemie-Transport-Modells untersucht. Zur Simulation der Ausbreitung der Flugzeugabgase wurden am EURAD-Modell-System umfangreiche Veraenderungen vorgenommen. Der obere Modellrand des Chemie-Transport-Modells ist von 100 hPa auf 10 hPa erhoeht worden. Die vertikale Aufloesung des Modells wurde insbesondere im Tropopausenbereich durch eine Erhoehung der Gesamtzahl der Modellschichten von 15 auf 29 wesentlich verfeinert. Ausserdem ist die Initialisierung der Spurenstoffverteilung im Modell an die Dynamik gekoppelt worden. Dem Chemie-Transport-Modell stehen damit an die jeweilige meteorologische Situation angepasste Konzentrationsfelder zur Initialisierung und zur Behandlung der Fluesse durch den Modellrand bereit. Zur repraesentativen Behandlung der atmosphaerischen Chemie wurde der Chemiemechanismus CHEST entwickelt und in das Chemie-Transport-Modell implementiert. CHEST beruecksichtigt die bedeutendsten chemischen Prozesse der Troposphaere und der unteren Stratosphaere. (KW)

  5. Contactless friction and the {sup 3}He-{sup 4}He dimer. Studies with the atomic-beam spin-echo spectrometer; Kontaktlose Reibung und das {sup 3}He-{sup 4}He-Dimer. Untersuchungen mit dem Atomstrahlspinechospektrometer

    Energy Technology Data Exchange (ETDEWEB)

    Janke, Matthias

    2016-04-20

    In this thesis the time of flight resolved atomic beam spin echo method (SEToF) is applied to a {sup 3}He-beam for the first time and studied systematically. This method is shown to be superior to the usual atomic beam spin echo technique. With SEToF it is possible to almost completely remove unpolarized background and to reach a beam polarisation close to 100%. The SEToF technique is shown to be crucial for the first experimental proof of the existence of the {sup 3}He-{sup 4}He dimer. This dimer is the weakest bound van-der-Waals-molecule known to date. Furthermore, a drag force between an atom and a dielectric surface is detected originating from the fluctuating dipole moment of the atom. Not only the measured friction coefficients match their theoretical predictions perfectly, but our data also shows the correct temperature dependence. A great many technological renewals and improvements were installed in the apparatus during this thesis work. They have become necessary or sensible due to the relocation of the physics institute. A few of them are documented and motivated in this thesis.

  6. Investigations towards multi-step laser spectroscopy of stored H{sub 3}{sup +} molecular ions; Untersuchungen zur Mehrstufen-Laserspektroskopie an gespeicherten H{sub 3}{sup +}-Molekuelionen

    Energy Technology Data Exchange (ETDEWEB)

    Bing, Dennis

    2010-07-21

    The triatomic H{sub 3}{sup +} molecular ion plays an important role in molecular quantum dynamics through its equilateral triangular structure. Many studies of molecular reactions involving H{sub 3}{sup +} have been done thus far, among them dissociative recombination in storage ring experiments with a cold electron-beam. For these strongly energy dependent reactions, the population in individual rovibrational levels is of large importance. To determine such populations for H{sub 3}{sup +} ions inside a storage ring, an extremely sensitive state-selective method must be used, such as the Resonant- Enhanced Multi-Photon Dissociation (REMPD). In REMPD, molecules are highly excited from a low lying initial level in a first resonant step and photodissociated from these high lying states in a second step. To fully employ this method, detailed investigations are necessary. Here, an experiment is presented which determines the energy range of the highly excited vibrational states of H{sub 3}{sup +} suitable for photodissociation. Additional photodissociation experiments, using hot H{sub 3}{sup +} ions in the storage ring TSR at the Max-Planck Institute for Nuclear Physics, yield an effective lifetime of these dissociated H{sub 3}{sup +} states. Finally selective vibrational excitation of cold H{sub 3}{sup +} (the rst step of REMPD) is discussed with the aim of reaching the highly excited vibrational states suitable for photodissociation. (orig.)

  7. Performance comparison of low and high temperature polymer electrolyte membrane fuel cells. Experimental examinations, modelling and numerical simulation; Leistungsvergleich von Nieder- und Hochtemperatur-Polymerelektrolytmembran-Brennstoffzellen. Experimentelle Untersuchungen, Modellierung und numerische Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Loehn, Helmut

    2010-11-03

    The experimental part of this thesis essentially comprises the performance comparison of low temperature (LT) - polymer electrolyte membrane fuel cells (PEMFCs) on basis of Nafion {sup registered} and high temperature (HT)- PEMFCs on basis of Polybenzimidazol (PBI)/phosphoric acid (H{sub 3}PO{sub 4}). The performance characteristic of commercially available Nafion {sup registered} - LT - (E-TEK-Series 12 W) and PBI/H{sub 3}PO{sub 4} - HT -(Celtec P 1000) membrane electrode assemblies (MEAs) were examined with a single cell in dependence of cell temperature (LT-MEA: 50 - 80 C, HT-MEA: 120 - 190 C), anode and cathode pressure (1 - 3 bar), stoichiometry of gas supply streams and relative humidity (only LT-MEA). Because of the same active cell area of both MEAs (45.16 cm{sup 2}) and the fact, that the flow field for the gas distribution of the test cell can be used universally, the performance tests with both MEA-types could be carried out with the same single test cell. When comparing the performance of both MEAs under similar test conditions - except increased temperature and deactivated humidification of the HT-MEA - at 0.7 A/cm{sup 2} with both MEA-types nearly equal performance densities of 0.3 - 0.45 W/cm{sup 2} can be reached. Since there is no liquid process water present in the HT-MEA the operation is not limited by concentration losses; therefore the HT-MEA can be operated in a wider range with higher current densities and because of the not required water management the operation of the HT-MEA is essentially simplified. Further advantages of the HT-MEA exist in the relative high tolerance against the catalyst poison carbon monoxide - the operation with reformat gas and hydrogen rich gases is facilitated - and an improved heat management because of the elevated operation temperature. However, a disadvantage of the Celtec-P-1000-MEA exists in the degradation at deep temperatures. At operating conditions, in which liquid process water is present, there is the danger of washing out of the phosphoric acid. In an additional test row the Celtec-P-1000 HT-MEA was subjected to temperature change cycles (40 - 160 C), which lead to irreversible voltage losses. In a final test row performance tests were carried out with a HT-PEM fuel cell stack (16 cells /1 kW), developed in the fuel cell research centre of Volkswagen with a special gas diffusion electrode, which should avoid the degradation at deep temperatures. In these examinations no irreversible voltage losses could be detected, but the tests had to be aborted because of leakage problems. The by the experimental examinations gained insight of the superior operating behaviour and the further advantages of the HT-PEMFC in comparison to the LT-PEMFC were crucial for the construction of a simulation model for a single HT-PEM fuel cell in the theoretical part of this thesis, that also should be suitable as process simulation model for the computer based development of a virtual fuel cell within the interdisciplinary project ''Virtual Fuel Cell'' at the TU Darmstadt. The model is a numerical 2D ''along the channel'' - model, that was constructed with the finite element software COMSOL Multiphysics (version 3.5 a). The stationary, one phase model comprises altogether ten dependent variables in seven application modules in a highly complex, coupled non linear system of equations with 33713 degrees of freedom (1675 rectangle elements with 1768 nodes). The simulation model describes the mass transport processes and the electro-chemical reactions in a HT-PEM fuel cell with good accuracy, the model validation by comparing the model results with experimental data could be proved. So the 2D-model is basically suitable as process simulation model for the projecting of a virtual HT-PEM fuel cell. (orig.)

  8. Theoretical assessment of the potential to deduce microphysical characteristics of ice clouds from polarimetric radar measurements at 95 GHz; Theoretische Untersuchungen zur Ableitung mikrophysikalischer Parameter von Eiswolken aus polarimetrischen Radarmessungen bei 95 GHz

    Energy Technology Data Exchange (ETDEWEB)

    Lemke, H.M. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Atmosphaerenphysik

    2000-07-01

    The potential of polarimetric radar measurements at 95 GHz to derive microphysical cloud characteristics is assessed. Scattering by atmospheric ice crystals is calculated applying the discrete dipole approximation (DDA) for single crystals of various shape, size, and orientation. The results are combined to acquire radar signals for collections of particles representing the radar volume. Expressing the particle size with respect to the radius of a volume equivalent sphere, the co-plar reflectivity is only slightly affected by particle shape variations. Thus, keeping the limitations of such an approach in mind, the simplified representation of crystals as spheres is applicable. On the other hand, the signal is strongly influenced by the particle size and the total ice water content. Polarimetric radar parameters like linear depolarisation ratio and differential reflectivity are almost independent of size and ice water content. They are predominantly affected by the crystal shape and orientation and therefore have a potential to deduce information about ice crystal habits. Unfortunately, to date such measurements are subject to technical restrictions. (orig.)

  9. Effects of active influencing of drivers on passenger car safety in road traffic; Untersuchungen zur Auswirkung einer aktiven Fahrerbeeinflussung auf die Fahrsicherheit beim Pkw-Fahren im realen Strassenverkehr

    Energy Technology Data Exchange (ETDEWEB)

    Bielaczek, C.

    1998-09-01

    The behaviour of car drivers in road traffic was investigated both in the `normal`, uninfluenced state and with supporting alarm systems informing the driver on critical situations. Systems of this kind may get more important as traffic density increases and increasingly comfortable cars cut the driver off from immediate feedback to recognize critical situations. The tests were carried out with fixted and with driver-adaptive alarm thresholds. Information was transmitted to the driver in the form of haptic/kinesthetic signals on the control elements for vehicle control, i.e. the steering wheel and the gas pedal. It is important to take account of the driver`s recognition of alarm signals under natural driving conditions as in road traffic. The best results were achieved with driver-adaptive alarm thresholds combined with the alarm signal `variable steering wheel control` which also met with high acceptance by the drivers. (orig.) [Deutsch] Die vorliegende Arbeit befasst sich mit der Untersuchung des Verhaltens von Pkw-Fahrern waehrend Fahrten im oeffentlichen Strassenverkehr im unbeeinflussten und durch Fahrer-Assistenz-Systeme beeinflussten Zustand des Fahrers, um die Auswirkung einer aktiven Fahrerunterstuetzung durch eine gezielte Warn-Signaluebermittlung an den Fahrer in kritischen Fahrsituationen zu untersuchen. Die Notwendigkeit einer solchen Untersuchung liegt einerseits in der staendig wachsenden Verkehrsdichte begruendet, die den Fahrer staerker belastet, andererseits aber auch in der durch verbesserten Komfort zunehmenden Entkopplung des Fahrers von der Umgebung, die sich im fehlenden Feedback zur Erkennung kritischer Fahrzustaende aeussert. - Es wurden, hinsichtlich des querdynamisch orientierten Kraftschlusspotentials, sowohl feste als auch fahreradaptive Warngrenzen definiert und ueberprueft. Die Informationsuebermittlung an den Fahrer wurde in Form von haptisch/kinaesthetischen Signalen (variable Betaetigungskraefte) an den Stellgliedern zur Fahrzeugfuehrung, dem Fahrpedal und der Lenkung, durchgefuehrt. - Ein sehr wichtiger Aspekt der Arbeit ist die Einbeziehung der Fahrerwahrnehmung von Warnsignalen unter natuerlichen Fahrerbelastungsbedingungen, wie sie in Feldversuchen im oeffentlichen Strassenverkehr gegeben sind. Dabei zeigten fahreradaptive Warngrenzen in Kombination mit den Warnsignalen `variable Lenkkraefte` den besten Erfolg hinsichtlich einer aktiven Fahrerbeeinflussung bei gleichzeitig hoher Akzeptanz dieses Systemansatzes. (orig.)

  10. Power transmission in combined compressors comprising a radial and side channel stage. Final report and appendices; Untersuchungen ueber die Energieuebertragung in kombinierten Verdichtern aus Radial- und Seitenkanalstufe. Abschlussbericht und Anlagen

    Energy Technology Data Exchange (ETDEWEB)

    Surek, D.

    2001-07-30

    In the field of turbo-compressors, the following problems must be solved in order to extend the range of operation: (a) Prevention of rotating stall at part load; (b) Extension of the permissible operating range at part load; (c) Extension of the operation range of radial and side channel compressors in higher vacuum below p{sub s}=50kPa. (c) can be achieved by changing the flow pattern in the rotor and in the region of interaction between the blade wheel and guide wheel of radial compressors or by actively influencing transient flow, e.g. by coupling radial compressor stages with a side channel compressor stage as final stage. The contribution goes into detail about the latter solution. [German] Fuer den Turboverdichterbau sind gegenwaertig folgende Probleme zur Erweiterung der Betriebsbereiche dringend zu loesen: (a) Vermeiden oder beseitigen von Rotating Stall im Teillastbereich,(b) Erweiterung des zulaessigen Arbeitsbereiches im Teillastgebiet, (c) Erschliessung des Arbeitsbereichs von Radial- und Seitenkanalverdichtern im hoeheren Vakuumbereich unterhalb von p{sub s}=50 kPa. Die Erweiterung des zulaessigen Arbeitsbereichs im Teillastgebiet kann durch Veraenderung der Stroemungsstruktur im Laufrad und im Interaktionsbereich zwischen Lauf- und Leitrad von Radialverdichtern oder durch die aktive Beeinflussung der instationaeren Stroemung z.B. durch Kopplung von Radialverdichterstufen mit einer Seitenkanalverdichterstufe als Endstufe erfolgen. Seitenkanalverdichter verfuegen ueber stabile Kennlinien im gesamten Betriebsbereich. Im Kombinationsbetrieb einer Radialverdichterstufe mit nach- oder vorgeschalteter Seitenkanalverdichterstufe praegte die Seitenkanalverdichterstufe dem Kombinationsverdichter ihr stabiles Kennlinienverhalten auf, so dass sich eine stabile Gesamtkennlinie ergibt. Eine Pumpgrenze tritt nicht mehr auf, so dass der Betrieb von Verdichterkombinationen aus Radial- und Seitenkanalstufe im gesamten Kennlinienbereich moeglich ist. Die nachgeschaltete Seitenkanalstufe mit der eigenen instationaeren turbulenten Wirbelstroemung beeinflusst die Stroemung der Radialverdichterstufe positiv, so dass die Druckzahl der Radialverdichterstufe im Kombinationsbetrieb gegenueber dem Einzelbetrieb um 2,3% erhoeht und der Arbeitsbereich zu groesseren und auch zu wesentlich kleineren Volumenstroemen verschoben werden kann. Die Ursachen fuer diese Beeinflussung der Kennlinie der Radialverdichterstufe durch die Seitenkanalverdichterstufe wurden durch die Untersuchung der instationaeren Druckschwingungen in beiden Verdichterstufen und am Druckstutzen des Verdichters ermittelt. Eine nachgeschaltete Seitenkanalverdichterstufe wirkt sich noch staerker auf die instationaere Stroemung in der Radialverdichterstufe aus als die vorgeschaltete Seitenkanalverdichterstufe. (orig.)

  11. Ausgrabung des frühbronzezeitlichen Gräberfelds der Aunjetitzer Kultur von Prag-Miškovice. Vorläufige Auswertung und erste Ergebnisse der naturwissenschaftlichen Untersuchungen: 14C-Daten und Metallanalysen

    Czech Academy of Sciences Publication Activity Database

    Ernée, Michal; Müller, J.; Rassmann, K.

    87/2009, č. 2 (2012), s. 355-410 ISSN 0016-8874 R&D Projects: GA ČR GA404/07/1408 Institutional research plan: CEZ:AV0Z80020508 Keywords : Praha-Miškovice * Early Bronze Age * necropoles * Únětice culture * radiocarbon dating * material analyses * long-distance contacts Subject RIV: AC - Archeology, Anthropology, Ethnology

  12. Studies on the turnover and properties of dump groundwaters in brown coal mining areas and possibilities of influencing them. Final report; Untersuchungen zum Stoffumsatz und zur Beschaffenheit der Kippengrundwaesser in Braunkohlebergbaugebieten und Moeglichkeiten zu deren Beeinflussung. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Katzur, J.; Liebner, F.; Liebner, C.; Welzel, H.P.; Hettrich, K.

    2001-07-01

    Only 6 days after the increase in pH with water saturation the concentration of iron in the pore water of the T1 sediment had dropped to a low value, 70% of which was accounted for by Fe(II). This is probably due to the almost complete precipitation of Fe(III) caused by the high pH values. Compared with the untreated variant the lowering of pH in the further course of the experiment led to a slight Fe(III) mobilisation and hence, through interaction with other reduction processes, to erratic changes in the share of Fe(II) in total Fe. Although this sediment showed a relatively low iron concentration a comparison showed that higher pH values and incubation temperatures have an influence on microbial iron reduction. [German] Im Porenwasser des Sedimentes T1 lag Eisen bereits 6 Tage nach pH-Erhoehung und Wassersaettigung nur noch in geringer Konzentration und zu ueber 70% als Fe(II) vor. Dies ist vermutlich in erster Linie auf die nahezu vollstaendige Ausfaellung von Fe(III) infolge der hohen pH-Werte zurueckzufuehren. Im weiteren Versuchsverlauf fuehrte das Absinken der pH-Werte zu einer im Vergleich zur unbehandelten Variante geringfuegigen Fe(III)-Mobilisierung und damit in Wechselwirkung mit ablaufenden Reduktionsprozessen zu unstetigen Veraenderungen in den Anteilen Fe(II) an Fe{sub ges}. Obwohl in diesem Sediment nur vergleichsweise niedrige Eisenkonzentrationen vorliegen, ergab ein Vergleich, dass hoehere pH-Werte und Inkubationtemperaturen die mikrobielle Eisenreduktion beeinflussen. (orig.)

  13. Developments and studies on the (T)HMC processes in a final repository for heat generating radioactive wastes. Synthesis and final report; Entwicklungen und Untersuchungen zu (T)HMC-Prozessen eines Endlagers fuer Waerme entwickelnde radioaktive Abfaelle. Synthese und Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Weyand, Torben [Bonn Univ. (Germany); Bracke, Guido; Fischer, Heidemarie; Frieling, Gerd; Hansmeier, Christina; Hotzel, Stephan; Kock, Ingo; Seher, Holger

    2014-10-15

    The report on developments and studies on the (T)HMC (thermal-hydraulic-mechanical-chemical) processes in a final repository for heat generating radioactive wastes covers the following topics: description of the projects, applied codes: TOUGH2, FLAC3D, TOUGH2 and FLAC3D, TOUHREACT/PetraSim, MARNIE, PHREEQC, geochemists workbench, SUSA; safety relevant singular processes in the transition phase, uncertainties due to process interactions, coupling of mass transport and geochemical equilibria, further developments and application of numerical simulations in the transition phase.

  14. Studies of nematode population of damaged forest ecosystems with special regard to phytopathogen species able to transmit viruses. Final report. Untersuchungen ueber Nematodenpopulationen in geschaedigten Waldoekosystemen unter besonderer Beruecksichtigung von pflanzenpathogenen Arten mit Virusuebertraegereigenschaften. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Sikora, R A; Gierlich, D; Lasthaus, U

    1989-02-01

    Over 250 soil and root samples were collected from forest nurseries and regional research plots as well as from open-air and open-top chambers. The samples were examined for plant parasitic, mycophagous and microphagous nematode and for nematodes able to transmit plant viruses. The results allow conclusions to be drawn concerning nematode population dynamics and the composition of the various trophic groups as related to intensity of forest decline in each station and to some extent to the pH level of the soil. (orig./MG).

  15. Diffusion-weighted imaging in the diagnostic evaluation of the hydrocephalus in patients with acute or chronic increase in cerebral pressure; Diffusionsgewichtete Bildgebung in der Diagnostik des Hydrocephalus - Untersuchungen an Patienten mit akuter und ohne akute Hirndrucksymptomatik

    Energy Technology Data Exchange (ETDEWEB)

    Dorenbeck, U. [Abt. fuer Neuroradiologie, Universitaetskliniken des Saarlandes, Homburg/Saar (Germany); Inst. fuer Roentgendiagnostik, Universitaetsklinik Regensburg (Germany); Schlaier, J. [Klinik und Poliklinik fuer Neurochirurgie, Universitaetsklinik Regensburg (Germany); Feuerbach, S.; Seitz, J. [Inst. fuer Roentgendiagnostik, Universitaetsklinik Regensburg (Germany)

    2005-01-01

    Purpose: to investigate whether diffusion-weighted imaging (DWI) in magnetic resonance imaging (MRI) provides additional information about the periventricular white matter for the assessment of hydrocephalus. Materials and methods: sixteen MRI examinations (11 with acutely increased cerebral pressure, 5 without symptoms) on 15 patients with hydrocephalus (4 patients with communicating hydrocephalus and 11 patients with obstructive hydrocephalus) were analyzed. One symptomatic patient subsequently became asymptomatic. We investigated the ''apparent diffusion coefficient'' (ADC) in the subcortical and periventricular white matter. The ADCs of the study patients were compared with those of a healthy control group. Results: symptomatic patients with hydrocephalus, 6/11 showed periventricular edema and a significantly higher ADC values in the periventricular region than in the subcortical white matter. 5/11 symptomatic patients showed significantly higher ADC values even in the absence of periventricular interstitial edema (both groups contained patients with communicating and obstructive hydrocephalus). All 5 asymptomatic patients with hydrocephalus did not have a significantly higher ADC values in the periventricular region. Conclusion: in patients with hydrocephalus and acutely increased cerebral pressure, DWI showed a significantly higher ADC values in the periventricular region even without visible interstitial edema on conventional MRI sequences. (orig.)

  16. Optimized sampling of hydroperoxides and investigations of the water vapour dependence of hydroperoxide formation during ozonolysis of alkenes; Optimierung der Probenahme von Hydroperoxiden und Untersuchungen zur Wasserdampfabhaengigkeit der Bildung von Hydroperoxiden bei der Ozonolyse von Alkenen

    Energy Technology Data Exchange (ETDEWEB)

    Becker, K.H.; Plagens, H.

    1997-06-01

    There are several sampling methods for hydroperoxides none of which is particularly reliable. The authors therefore tested three new methods in order to optimize hydroperoxide sampling and, using the optimized sampling procedure, to investigate the water vapour dependence of hydroperoxide formation during ozonolysis of alkenes. (orig.) [Deutsch] Fuer die Probenahme von Hydroperoxiden existieren verschiedene Verfahren, von denen bisher keines als besonders zuverlaessig angesehen werden konnte. Daher wurden in dieser Arbeit drei Verfahren getestet, um die Probenahme von Hydroperoxiden zu optimieren und mit dem entsprechenden Verfahren die Wasserdampfabhaengigkeit der Bildung von Hydroperoxiden bei der Ozonolyse von Alkenen zu untersuchen. (orig.)

  17. In-depth investigation of high-energy arcing faults (HEAF) of electrical components with possible induced fires; Vertiefte Untersuchungen zum hochenergetischen Versagen elektrischer Komponenten (HEAF) mit moeglicher Brandfolge

    Energy Technology Data Exchange (ETDEWEB)

    Roewekamp, Marina

    2015-11-15

    Main objective of the project 3611R01301 performed on behalf of the Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety (BMUB) is an in-depth investigation of fires at electrical components induced by high energy arcing faults (HEAF) according to their non-negligible significance to nuclear safety. This report provides an overview on the insights with respect to high energy arcing faults at electrical components mainly gained from investigations of the national as well as international operating experience from nuclear installations. Moreover, the insights from the international operating experience have resulted in an experimental program carried out in the frame of a task by the OECD Nuclear Energy Agency (NEA) in order to investigate failures of electrical components, e. g. breakers, switchgears or transformers, installed in nuclear power plants of the member countries due to HEAF and potential consequential fires. The results of the in-depth analyses and experimental investigations shall be used for identifying potential areas of damage in a suitable manner. The results based on inter-national research shall also be checked with respect to their applicability to the situation in German nuclear power plants.

  18. KEROMIX. Sub-project: Basic experimental studies on mixing in swirl flow in gas turbine combustion chambers. Final report; KEROMIX. Arbeitspaket: Grundlegende experimentelle Untersuchungen der Mischungsvorgaenge drallbehafteter Stroemungen in Gasturbinenbrennkammern. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Hennecke, D K

    2000-07-01

    This report describes investigations on advanced lean fuel combustion technologies with stable and low-pollution combustion in an aircraft gas turbine in all load stages. The key factors, i.e. stability and low pollutant concentrations, are closely related to the mixing characteristic of the combustion chamber. Lean fuel combustion does not go well with stable combustion which is indispensable inan aircraft engine. Further, the lean mixture must be maintained throughout the combustion chamber as local stoichiometries would automatically result in higher concentrations of nitric oxides. To solve the problems related to these processes, detailed knowledge of the mixing processes is required. [German] Als Teilprojekt des Vorhabens 'KEROMIX, stabile, schadstoffarme Magerverbrennung' leistet die vorliegende Arbeit einen wichtigen Beitrag zur Beherrschung fortschrittlicher Verbrennungstechniken unter Anwendung des Mager-Konzeptes. Im Rahmen des Verbundprogrammes zum Technologieprogramm ENGINE 3E steht die Entwicklung von Verbrennungskonzepten, die eine stabile und schadstoffarme Verbrennung ueber den gesamten Lastbereich einer Flugzeug-Gasturbine hinweg gewaehrleisten. Die hier entscheidenden Attribute der Verbrennung, naemlich Stabilitaet und Schadstoffarmut sind eng mit der Mischungscharakteristik einer Brennkammer verbunden. Hier gilt es, die zum Teil gegenlaeufigen Effekte, die in einer Brennkammer auftreten, kontrollierbar zu machen. So steht die zur Verminderung der Stickoxidproduktion geforderte magere Verbrennung im ausgesprochenen Gegensatz zur Forderung einer in allen Betriebsbereichen stabilen Verbrennung, die allein schon aus Flugsicherheitsgruenden unabdingbar ist. Desweiteren muss der magere Gemischzustand unbedingt in der gesamten Brennkammer eingehalten werden, da lokale stoechiometrische Zustaende sofort zum Anstieg der Stickoxidproduktion fuehren. Um diese Prozesse beherrschen zu koennen, ist eine detaillierte Kenntnis der Mischungsvorgaenge bezueglich ihrer raeumlichen und zeitlichen Ausdehnung noetig. (orig.)

  19. In-depth evaluations of operating experiences in nuclear power plants. Annual report 2015/2016 (June 2015 - May 2016); Vertiefte Untersuchungen von Betriebserfahrungen aus Kernreaktoren. Jahresbericht 2015/2016 (Juni 2015 - Mai 2016)

    Energy Technology Data Exchange (ETDEWEB)

    Mildenberger, Oliver

    2017-05-15

    A central task of GRS is the continuous evaluation of events in nuclear power plants in Germany and abroad on behalf of BMUB. GRS evaluates all reportable events from German plants as well as safety-relevant events in foreign nuclear power plants. It aims for the extraction of scientific insights and information to extend the knowledge base of GRS. Learning from operating experience is an important element for preserving and improving the safety level of nuclear power plants. Insights obtained from these in-depth evaluations form the scientific bas is for expert statements, information notices or generic reports on behalf of BMUB. This report presents major results of generic in-depth investigations on safety-relevant aspects detected during the screening of operating experience from all available sources in the reporting period. Moreover, the results of additional further works to determine and advance the state of the art in science and technology related to the evaluation of operating experience are summarized: Pilot study on evaluation of U.S. NRC Licensee Event Reports (LER); Update of knowledge base on transients; Extension of CCF checklist with CCF phenomena in valves and big machine components (pumps, emergency diesels, ventilations, heat exchangers and chillers); Generic analysis of events with errors during periodic inspections; Experiences with errors during construction and operation of nuclear concrete buildings; Assessment of results from precursor analyses.

  20. Investigations on autothermal reforming of kerosene Jet A-1 for supplying solid oxide fuel cells (SOFC); Untersuchungen zur autothermen Reformierung von Kerosin Jet A-1 zur Versorgung oxidkeramischer Festelektrolyt-Brennstoffzellen (SOFC)

    Energy Technology Data Exchange (ETDEWEB)

    Lenz, B.

    2007-01-25

    The auxiliary power unit of commercial aircraft is a gas turbine producing electric power with an efficiency of 18 %. This APU can be replaced by a fuel cell system, consisting of an autothermal kerosene reformer and a solid oxide fuel cell (SOFC). The fuel is kerosene Jet A-1. The autothermal reforming of Jet A-1 is practically investigated under variation of steam-to-carbon-ratio, air ratio, space velocity, time in operation and reactor pressure on commercial catalysts. Using stationary system simulation the thermodynamic processes of the device is investigated. Finally, the autothermal reformer and the SOFC consisting of 14 cells are coupled. During this test series, I-V-characteristics are measured, fuel utilisation is calculated and the self-sufficient system operation is shown. (orig.)

  1. Investigations of time-dependent water pollution effects of overburden dumps - partial project 1. Final report; Untersuchungen gewaesserrelevanter Einfluesse von Bergbauhalden in Abhaengigkeit von der Standzeit - Teilprojekt 1. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Beuge, P.; Dunger, C.; Mibus, J.; Starke, R.

    1998-02-01

    Management of overburden dumps necessitates careful stocktaking and precise definitions of pollutant emissions so that, if necessary, conclusions can be drawn concerning sanitation concepts in consideration of emission limits and environmental balances. In view of the large number of overburden dumps in Saxony, Saxony-Anhalt and Thuringia caused the authors to restrict their investigations to ore mines and to select elements characteristic of the worked deposits and their potential environmental effects. The following problems were investigated: Are overburden dumps significant emitters of elements at all? Which elements are emitted in what concentrations, in what form and up to what distance from the dump? Are there really different patterns for gangue and impregnation types? How big is the real reaction space of the dump? Should the whole dump be assumed to be a reservoir of elements for emission or just parts of it? What are the factors that most strongly influence element mobilisation and/or retention? What measures should be recommended for emission reduction or prevention from the aspects of necessity, economic efficiency and long-term stability? (orig./SR) [Deutsch] Es ergibt sich fuer den Umgang mit Halden die Notwendigkeit einer gruendlichen Bilanzierung und schaerferen Definition von Schadstoffemission aus ihnen, um daraus Konsequenzen fuer eventuell erforderliche Sanierungskonzeptionen unter Beruecksichtigung von Grenzwerteinhaltung und Umweltbilanz abzuleiten. Der Umfang der einzelnen Fragestellungen und die Bedeutung der Halden in Sachsen, Sachsen-Anhalt und Thueringen sowie Anzahl und ihr Inhalt fuehrte zur Beschraenkung auf den Erzbergbau und auf die Kontrolle ausgewaehlter Elemente, die fuer den jeweils abgebauten Lagerstaetteninhalt charakteristisch und fuer die Wirkung auf die Umwelt von Bedeutung sind. Folgende konkrete Fragestellungen sollen verfolgt werden: - Sind Halden ueberhaupt nennenswerte Emittenten von Elementen? - Welche Elemente werden in welchen Konzentrationen bis zu welchen Entfernungen von der Halde in welcher Form emittiert? - Existieren die vermuteten Unterschiede und Muster zwischen Gangerz- und Impraegnationstyp? - Wie gross ist der Reaktionsraum einer Halde wirklich? Muss der gesamte Haldenkoerper als potentielles Elementereservoir fuer Emissionen zum Ansatz gebracht werden oder nur Anteile? - Kommt es zur selbstaendigen Ausbildung von haldeninternen geochemischen Barrieren? - Welche Fakto ren beeinflussen am staerksten die Mobilisation bzw. Retention von Elementen? - Welche Massnahmen erscheinen fuer eine Emissionserniedrigung oder -verhinderung am geeignetsten unter den Gesichtspunkten der Notwendigkeit, der Oekonomie und der Langzeitstabilitaet? (orig./SR)

  2. Investigations of water pollution effects of mining spoil heaps depending on the period of existence. Final report. Part project 2; Untersuchungen gewaesserrelevanter Einfluesse von Bergbauhalden in Abhaengigkeit von der Standzeit. Abschlussbericht. Teilprojekt 2

    Energy Technology Data Exchange (ETDEWEB)

    Puchelt, H.; Stueben, D.; Berner, Z.; Kappes, B.

    1996-12-01

    Apart form the main elements, the Wiesloch Ag-Pb-Zn mineralisation contains a series of higly toxic trace elements. The main ore minerals of galena, zinc blende and Menikow pyrites also contain Tl, Cd, As and Sb up to the precent range. The main and trace element contents of ores, flotation residues and slags were examined in detail. Their weathering properties were estimated, depending on the time of existence, from new secondary mineral formations. An element displacement from the spoil heaps reaching several decimetres in the ceiling was shown. Strong contamination can be proved by washing out and dispersion of As and Tl in agriculturally used areas and can be found in plants. Using elution experiments, the metal release of hevy metals and arsenic from ores, flotation wastes and slags was examined for the quantitative estimation of the material transfer. Also, the excellent suitability of synthetic Fe-Mn hydroxides for the decontamination of water containing arsenic and heavy metals was shown. (orig.) [Deutsch] Die Wieslocher Ag-Pb-Zn-Vererzung enthaelt neben den Hauptelementen eine Reihe von hochtoxischen Spurenelementen. Die Haupterzminerale Bleiglanz, Zinkblende und Melnikowitpyrit enthalten zusaetzlich Tl, Cd, As sowie Sb bis in den Prozentbereich. Im Detail wurde der Haupt- und Spurenelementgehalt von Erzen, Flotationsrueckstaenden und Schlacken untersucht. Ihre Verwitterungseigenschaften wurden in Abhaengigkeit der Standzeit anhand von sekundaeren Mineralneubildungen abgeschaetzt. Eine mehrere dm-weit reichende Elementverlagerung aus Halden in das Liegende (Loessdecke) konnte nachgewiesen werden. Starke Kontaminationen sind durch Auswaschung und Dispersion von As und Tl in landwirtschaftlich genutzen Flaechen nachzuweisen und in Pflanzen wiederfindbar. Zur quantitativen Abschaetzung des Stofftransfers wurde anhand von Elutionsversuchen die Metallfreisetzung von Schwermetallen und Arsen aus Erz, Flotationsabgaengen und Schlacken untersucht. Ausserdem konnte die ausgezeichnete Eignung von kuenstlichen Fe-Mn-Hydroxiden fuer die Dekontamination von Arsen- und Schwermetall haltigen Waesser gezeigt werden. (orig.)

  3. Water pollution potential of mineral oils with high content of polycyclic aromatic hydrocarbons (heavy fuel oil and neutral oil extracts); Untersuchungen zur Wassergefaehrdung durch Mineraloele mit hohen Gehalten an polycyclischen aromatischen Kohlenwasserstoffen (Heizoel Schwer und Extrakte)

    Energy Technology Data Exchange (ETDEWEB)

    Albers, G. [Mobil Schmierstoff GmbH, Hamburg (Germany)

    1999-01-01

    A data base on highly aromatic mineral oils has been compiled to classify mineral oil products according to their water-pollution potential (water hazard class or Wassergefaehrdungsklasse, WGK). This activity has been undertaken through the Commission for Water Hazardous Materials (Kommission Bewertung Wassergefaehrdender Stoffe, KBwS). In this special case, highly aromatic mineral oils containing a high concentration of polycyclic aromatic hydrocarbons (Polyaromatische Kohlenwasserstoffe, PAK) were evaluated. A test method for measuring the elution potential of PAK into water was developed on petroleum products with high viscosity and high freeze point. This method was applied to determine the solubility of 23 PAK (including 16 PAK according to EPA 610 and 6 PAK according to the German drinking water regulation (Trinkwasserverordnung, TVO)) from heavy fuel oil and neutral oil extract in the aqueous phase. For the 6 PAK, according to TVO, a sum limit of 0,2 {mu}g/l in drinking water is permitted by German legislation. This limit was not exceeded in any of the water phases examined. (orig.) [Deutsch] Fuer die Einstufung von Mineraloelprodukten in die Wassergefaehrdungsklassen (WGK) durch die Kommission Bewertung Wassergefaehrdender Stoffe ist es notwendig, Basisdaten zur Verfuegung zu stellen. Im speziellen Fall handelt es sich um die Bewertung von Mineraloelen, die sich durch einen hohen Gehalt an polycyclischen aromatischen Kohlenwasserstoffen (PAK) auszeichnen. Zur Eluierbarkeit von PAK`s aus Produkten mit hoher Viskosiaet bzw. mit hohem Stockpunkt wurde eine Pruefmethode entwickelt. Diese Methode wurde zur Bestimmung der Loeslichkeit von 23 PAK`s (16 PAK`s nach EPA-Liste incl. 6 PAK`s der TVO) aus den Mineraloelen Heizoel Schwer und Neutralextrakt in der Wasserphase eingesetzt. Fuer die PAK der TVO ist in der TVO ein Summengrenzwert von 0,2 {mu}g/l Trinkwasser angegeben. Dieser Grenzwert wurde in keiner der untersuchten Wasserphasen ueberschritten. (orig.)

  4. Study on the safety during transport of radioactive materials. Pt. 4. Events during transport. Final report work package 6; Untersuchungen zur Sicherheit bei der Befoerderung radioaktiver Stoffe. T. 4. Ereignisse bei der Befoerderung. Abschlussbericht zum Arbeitspaket 6

    Energy Technology Data Exchange (ETDEWEB)

    Sentuc, Florence-Nathalie

    2014-09-15

    This report presents the results from a data collection and an evaluation of the safety significance of events in the transportation of radioactive material by all modes on public routes in Germany. Systems for reporting and evaluation of the safety significance of events encountered in the transport of radioactive material are a central element in monitoring and judging the adequacy and effectiveness of the transport regulations and their underlying safety philosophy, this allows for revision by experience feedback (lessons learned). The nationwide survey performed covering the period from the mid 1990s through 2013 identified and analysed a total of 670 transport events varying in type and severity. The vast majority of recorded transport events relate to minor deviations from the provisions of the transport regulations (e.g. improper markings and error in transport documents) or inappropriate practices and operational procedures resulting in material damage of packages and equipment such as handling incidents. Severe traffic accidents and fires represented only a small fraction (ca. 3 percent) of the recorded transport events. Four transport events were identified in the reporting period to have given rise to environmental radioactive releases. Three transport events have reportedly resulted in minor radiation exposures to the transport personnel; in one case an exposure in excess of the statutory annual dose limit for the public seems possible. Based on the EVTRAM scale, with seven significance levels, the broad majority of transport events has been classified as ''non-incidents'' (Level 0) and ''events without affecting the safety functions of the package'' (Level 1). On the INES scale most transport events would be classified as events with ''no safety significance'' (Below Scale/Level 0). The survey results show no serious deficiencies in the transport of radioactive material, supporting the conclusion that a high level of safety and protection is ensured by the existing regulatory requirements. However, there is potential for improvement notably through avoiding common administrative deviations that could be rectified by training and qualification of the involved transport personnel. Otherwise, harmonising and consolidating of transport event reports would be a preferable future goal.

  5. Investigations on pretreatment of waste prior to fermentation by percolation using the ISKA {sup registered} process; Untersuchungen zur Vorbehandlung von Abfaellen vor der Vergaerung mittels Perkolation nach dem ISKA {sup registered} -Verfahren

    Energy Technology Data Exchange (ETDEWEB)

    Santen, H. [Technische Univ. Braunschweig (Germany). FG Abfallwirtschaft; Fricke, K. [Technische Univ. Braunschweig (Germany). Lehrstuhl Abfallwirtschaft; Engelhard, T.; Widmer, C. [ISKA GmbH, Ettlingen (Germany)

    2004-07-01

    Waste treatment prior to fermentation is a key aspect in achieving economic efficiency. One process is presented here in particular: percolation, in which waste is hydrolyzed aerobically, treated mechanically, and washed out with the aid of process water. The process involves a percolation stage followed by a fermentation stage. The process water burdened with organic matter is passed into a fermentation reactor in which the organic components are reacted anaerobically into biogas and bacterial mass, and the process water is recirculated into the percolation reactor. (orig.) [German] Vergaerungstechnologien zaehlen zu den etablierten Verfahren zur Gewinnung regenerativer Energien aus Biomasse. Fuer die Energieeffizienz dieser Verfahren sind die Leistung der Vergaerungsstufe, die Hoehe der Verfuegbarkeit der anaerob abzubauenden organischen Substanzen und der spezifische Energiebedarf des Behandlungsverfahrens massgeblich. Eine Schluesselstellung fuer die Optimierung beider Faktoren nimmt die Abfallaufbereitung vor der Vergaerung ein. Eine Technoloie zur Aufbereitung vor der Vergaerung basiert auf dem Verfahren der Perkolation, in der der Abfall aerob hydrolysiert,mechanisch aufgeschlossen und durch Zugabe von Prozesswasser ausgewaschen wird. Das Verfahren besteht aus einer Aufbereitung - der Perkolation - sowie einer nachgeschalteten Vergaerung. Das mit vergaerbarer Organik beladene Prozesswasser wird einem Vergaerungsreaktor zugefuehrt, in dem die organischen Komponenten anaerob zu Biogas und Bakterienmasse umgesetzt werden. Das aufbereitete Prozesswasser wird anschliessend wieder dem Perkolationsreaktor zugefuehrt. (orig.)

  6. Experimental investigation of a non-equilibrium expansion flow after hydrogen/air combustion in hypersonic ramjet engines; Experimentelle Untersuchungen zur Nichtgleichgewichtsexpansionsstroemung nach Wasserstoff/Luft-Verbrennung in Hyperschall-Staustrahltriebwerken

    Energy Technology Data Exchange (ETDEWEB)

    Weisgerber, H.

    2002-03-01

    The exhaust gas flow in the model thrust nozzle under investigation is characterized by chemical and thermal (vibrational) non-equilibrium which is experimentally detected by differing rotational and vibrational temperatures in the supersonic region of the nozzle. An analytical method to determine the vibrational relaxation time from expansion experiments is presented and validated using literature data. The nitrogen vibrational temperature at the nozzle exit strongly depends on the relaxation time of collisions with water molecules; for this process a correlation from the literature is selected. The measurements are completed by an experimental and numerical analysis of velocimetry tracer particle motion in flows with strong velocity gradients and an experimental investigation of the causes and effects of laser beam distortions occurring in high enthalpy flows. So a reliable database is presented for a reacting flow in a model nozzle of rectangular cross-section which was already used to validate a CFD code including the model of thermal non-equilibrium effects. (orig.) [German] Die Stroemung eines Abgases in der untersuchten Modellschubduese ist charakterisiert durch chemisches und thermisches (vibratorisches) Nichtgleichgewicht, das durch die Abweichung der Vibrations- von der Rotationstemperatur des Stickstoffmolekuels im Ueberschallteil der Duese experimentell belegt wird. Eine Methode zur analytischen Ermittlung der Vibrationsrelaxationszeit aus Expansionsexperimenten wird vorgestellt und anhand von Literaturdaten validiert. Die entscheidende Groesse fuer die Vibrationstemperatur des Stickstoffs am Duesenaustritt ist die Relaxationszeit beim Stoss mit einem Wassermolekuel; aus den fuer diesen Vorgang vorliegenden Literaturangaben wird eine Korrelation ausgewaehlt. Zur Absicherung der Messungen wird zum einen das Folgeverhalten von zur Geschwindigkeitsmessung zugefuegten Partikeln in Stroemungen mit starken Geschwindigkeitsgradienten experimentell und numerisch analysiert; zum anderen werden die in Hochenthalpiestroemungen zum Teil beobachteten optischen Signalstoerungen bezueglich ihrer Ursachen und Auswirkungen experimentell untersucht. Es resultiert ein belastbarer Datensatz zur reagierenden Stroemung in einer Rechteckduese, an dem bereits ein numerisches Verfahren hinsichtlich der Modellierung thermischer Nichtgleichgewichtseffekte erfolgreich validiert werden konnte. (orig.)

  7. Potentiometric studies on the complexes of tetracycline (TC) and oxytetracycline (OTC) with some metal ions. Potentiometrische Untersuchungen der Komplexe von Tetracyclin (TC) und Oxytetracyclin (OTC) mit einigen Metall-Ionen

    Energy Technology Data Exchange (ETDEWEB)

    Ghandour, M A; Azab, H A; Hassan, A; Ali, A M [Assiut Univ. (Egypt)

    1992-01-01

    The interaction of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Zn(II), Cd(II), Hg(II), Pb(II), Al(III), and UO[sub 2](II) ions with tetracycline (TC) were studied by potentiometric pH titrations. The formation constants of the different binary complexes formed in such systems have been determined at 25[+-]0.1 deg C and [mu]=0.1 moll[sup -1] (NaNO[sub 3]). Potentiometric pH equilibrium measurements have been made under the same conditions for the interaction of oxytetracycline (OTC) and Cu(II), Cd(II), Pb(II), and UO[sub 2](II). The formation of (1:1) binary complexes are inferred from the potentiometric pH titration curves. The protonation constants of TC and OTC were also determined under the same conditions and refined (ESAB2M computer program). The transition metal stability constants are consistent with the Irving-Williams series. (authors).

  8. Voltammetric studies on composition and stabilities of complexes of tetracycline and oxytetracycline with some metal ions in aqueous medium. Voltammetrische Untersuchungen zur Zusammensetzung und Stabilitaet von Komplexen von Tetracyclin und Oxytetracyclin mit einigen Metallionen in waessrigem Medium

    Energy Technology Data Exchange (ETDEWEB)

    Ghandour, M A; Azab, H A; Hassan, A; Ali, A M [Dept. of Chemistry, Faculty of Science, Assiut Univ., Assiut (Egypt)

    1992-01-01

    The composition and stability of complexes of tetracycline and oxytetracycline with Cu(II), Cd(II), Pb(II) and UO[sub 2](II) have been studied polarographically (direct current and differential pulse polarographic techniques) at 25[+-]0.1 deg C. Differential pulse polarographic studies have been particularly helpful in deciding the nature of metal-drug interactions at low concentrations. The reduction of Cu(II)-tetracycline has been found to be irreversible and diffusion controlled with the presence of an adsorption component. In the system uranyl(II)-tetracycline the complex formed has a stoichiometry of 1:1 and log K[sub ox] = 4.04 which is very close to that obtained by potentiometric measurements. The peak half width W[sub 1/2] of the Pb(II)-OTC system is 60-70 mV indicating that the process is reversible and two electrons are consumed. The log [beta]' is 10.30 in 0.1 mol dm[sup -3] NaClO[sub 4]. In the Cu(II)-OTC system two complexes were formed with log [beta][sub 1]' = 8.50 and log [beta][sub 2]' = 14.10. Cyclic voltammograms were recorded using a hanging dropping mercury electrode for the systems Cu(II), Cd(II), Pb(II) and UO[sub 2](II)-OTC to examine the irregularities in both peak potentials and peak currents during the polarographic investigations. (authors).

  9. Open table-top device positioning technique to reduce small bowel obstruction. Positioning accuracy and impact on conformal radiation therapy techniques; Lochbrettechnik zur Duenndarmschonung. Untersuchungen zur Lagerungsgenauigkeit unter Beruecksichtigung konformierender Bestrahlungstechniken

    Energy Technology Data Exchange (ETDEWEB)

    Rudat, V. [Abteilung Strahlentherapie, Klinische Radiologie, Universitaetsklinikum Heidelberg (Germany); Flentje, M. [Abteilung Strahlentherapie, Klinische Radiologie, Universitaetsklinikum Heidelberg (Germany); Engenhart, R. [Abteilung Strahlentherapie, Klinische Radiologie, Universitaetsklinikum Heidelberg (Germany); Metzger, M. [Abteilung Strahlentherapie, Klinische Radiologie, Universitaetsklinikum Heidelberg (Germany); Wannenmacher, M. [Abteilung Strahlentherapie, Klinische Radiologie, Universitaetsklinikum Heidelberg (Germany)

    1995-08-01

    The immobilization error of patients positioned on the opern table-top device in prone prosition as well as the movement of the small bowel out of the pelvis by this positioning technique was determined. The positioning error is of special importance for the 3-dimensional treatment planning for conformal radiotherapy. The positioning error was determined by superposing 106 portal films with the corresponding simultor films from 21 patients with carcinoma of the rectum who received 3D-planned conformal radiotherapy (o-field technique with irregular blocks). The movement of the small bowel out of the pelvis was studied by comparing simulator films after barium swallow in supine and open table-top position as well with 3D-treatment plans of the same patient in both positions in 3 cases. The positioning error along the medio-lateral, dorso-ventral und cranio-caudal axis was 1.4/-0.6/1.8 mm and the standard deviation 4.4/6.8/6.3 mm, respectively. In comparison to the supine position more rotation errors in the sagittal view were observed (37% and 9% respectively) with a media of 5.1 . Six out of 22 patients showed no adhesions of the small bowel and a complete movement out of the tratment field was achieved. 14 out of 16 Patients with adhesions revealed a partial movement of the small bowel out of the treatment field. Comparing 3D-treatment plans in both positions again demonstrated a marked reduction of the irradiated small bowel volume with the use of the open table-top decive. (orig.) [Deutsch] Die Anwendung der Lochbrettechnik sowie konformierender Bestrahlungstechnik laesst eine Verminderung der Duenndarmbelastung bei der Bestrahlung pelviner Tumoren erwarten. Die Lagerungsgenauigkeit der Patienten als wichtiger Gesichtspunkt bei der dreidimensionalen Bestrahlungsplanung wurde bestimmt und die Duenndarmverlagerung aus dem Bestrahlungsfeld bei der Patientenlagerung im Lochbrett untersucht. Saemtliche zu untersuchende Patienten erhielten eine dreidimensional geplante Konformationsstrahlentherapie des Beckens bei Rektumkarzinom (Drei-Felder-Technik mit irregulaeren Bloecken) und wurden durch Laserausrichtung anhand von Hautmarkierungen in Bauchlage im Lochbrett gelagert. Die Lagerungsgenauigkeit wurde durch subtraskopische Ueberlagerung von 106 Verifikationsaufnahmen von 21 Patienten mit den entsprechenden Simulationsaufnahmen ermittelt. Duenndarmverlagerungen wurden anhand des Vergleichs von Simulationsaufnahmen nach oraler Gabe von Kontrastmittel bei 22 Patienten sowie bei drei Patienten durch Vergleich zweier dreidimensionaler Bestrahlungsplaene jeweils in Ruecken- und Bauchlage im Lochbrett bestimmt. Die Lagerungsgenauigkeit in Bauchlage im Lochbrett (Mittelwert) in der mediolateralen, dorsoventralen und kraniokaudalen Ebenen betrug 1,4/-0,6/1,8 mm mit einfachen Standardabweichungen von 4,4/6,8/6,3 mm. Deutlich haeufiger im Vergleich zur Rueckenlage wurden Rotationsfehler beobachtet (37% gegenueber 9%), die im Median 5,1 berugen. Sechs von 22 Patienten wiesen keine Duenndarmfizierungen auf, und bei diesen Patienten konnte eine vollstaendige Verlagerung des Duenndarms aus dem Bestrahlungsfeld beobachtet werden. Bei 14 von 16 Patienten mit Duenndarmfixierungen konnte eine partielle Reduktion des Duenndarmvolumens innerhalb des Bestrahlungsfeldes erreicht werden. Vergleichende dreidimensionale Bstrahlungsplaene zeigten eine deutliche Reduktion des bestrahlten Duenndarmpartialvolumens in Bauchlage im Lochbrett gegenueber Rueckenlage. (orig.)

  10. Seepage water flow velocity in hydromorphic acid brown earth in northeast Germany - {sup 15}N studies in groundwater lysimeters; Sickerwassergeschwindigkeit in Hydromorphen Sauerbraunerden Nordostdeutschlands - {sup 15}N-Untersuchungen in Grundwasserlysimetern

    Energy Technology Data Exchange (ETDEWEB)

    Behrendt, A.; Hoelzel, D.; Schalitz, G. [ZALF Muencheberg, Paulinenaue (Germany). Forschungstation; Merbach, W. [ZALF Muencheberg, Paulinenaue (Germany). Inst. fuer Rhizosphaerenforschung und Pflanzenernaehrung

    1999-02-01

    Sandy soils occur widely in Brandenburg. These soils are usually characterised by a high permeability. In low-lying areas such the Havellaendische Luch their proximity to groundwater can pose problems, especially when nutrients such as nitrate are not fully absorbed by the plants and are leached into the ground. Lysimeter studies with stable isotope tracers are especially well suited for estimating the leaching loss attributable to mineral fertilisation. For one thing, lateral flow can largely be excluded in the closed system of a lysimeter. For another, one can reasonably suppose that the marked nitrogen does not behave essentially differently from normal nitrogen. [Deutsch] In Brandenburg kommen verbreitet sandige Boeden vor. Diese Boeden zeichnen sich meist durch hohe Durchlaessigkeiten aus. Dadurch kann in Niederungsgebieten, wie dem Havellaendischen Luch, die Grundwassernaehe zum Problem werden, insbesondere wenn Naehrstoffe wie Nitrat nicht vollstaendig von den Pflanzen aufgenommen werden und der Auswaschung anheimfallen. Zur Abschaetzung der Auswaschungsverluste, die tatsaechlich aus der Mineralduengung stammen, eignen sich besonders Lysimeteruntersuchungen mit stabilisotopen Tracern. Einerseits lassen sich hier, im geschlossenen System, laterale Stroemungen weitgehend ausschliessen, andererseits kann man davon ausgehen, dass sich der makierte Stickstoff im System Boden-Pflanze nicht grundsaetzlich anders verhaelt als herkoemmlicher Stickstoff. (orig.)

  11. Soil ecological investigations into the effect and distribution of organic groups of compounds (PAHs, PCBs) in ecosystems typical of agglomerations.. Joint final report; Bodenoekologische Untersuchungen zur Wirkung und Verteilung von organischen Stoffgruppen (PAK, PCB) in ballungsraumtypischen Oekosystemen. Gemeinsamer Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Frost, M.; Klementz, D.; Reese-Staehler, G.; Luedersdorf, M. [Biologische Bundesanstalt fuer Land- und Forstwirtschaft, Berlin (Germany); Achazi, R.; Kratz, W.; Heck, M.; Beylich, A.; Neumeister, H.; Hesse, M.; Quader, S. [Freie Univ. Berlin (Germany); Metz, R.; Dorn, J. [Humboldt-Universitaet, Berlin (Germany); Schuphan, I.; Maier-Gaipl, S.; Herlitz, E. [Technische Hochschule Aachen (Germany); Wilke, B.M.; Koch, C.; Marschner, B.; Brose, A.; Doering, U.; Peters, M.; Pieper, S.; Baschien, C. [Technische Univ. Berlin (Germany)

    1998-11-01

    In this interdisciplinary complex of matched field and laboratory experiments, the effects of defined pollutant loads were analysed by means of suitable representatives of different groups of soil organisms (soil fauna and soil micro-organisms) and by means of soil processes depending on them (for instance, enzyme activities, degradation of litter, nitrification, feeding damage). Similarly, the influence of selected organic pollutants, part of them in combination with heavy metals, on the soil-plant system was studied in selected herbaceous and ligneous types of plants in different development stages. Further, the possibility of developing a test battery was investigated which would indicate the toxicity of soil by means of watery and organic extracts. (orig.) [Deutsch] In diesem interdisziplinaeren Verbund von abgestimmten Freiland- und Laborversuchen wurde anhand repraesentativer Vertreter verschiedener Bodenorganismengruppen (Bodenfauna und Bodenmikroorganismen) und von durch sie bestimmten Bodenprozessen (z.B. Enzymaktivitaeten, Streuabbau, Nitrifikation, Frass) die Wirkungen von definierten Schadstoffbelastungen analysiert. In der gleichen Weise wurde der Einfluss von ausgewaehlten organischen Schadstoffen, z.T. in Kombination mit Schwermetallen auf das System Boden-Pflanze an ausgewaehlten krautigen und holzigen Pflanzenarten in unterschiedlichen Entwicklungsstadien untersucht. Darueberhinaus wurde ueberprueft ob sich eine Testbatterie entwickeln laesst, die die Toxizitaet von Boeden aufgrund von waessrigen und organischen Extrakten anzeigt. (orig.)

  12. Studies on validation possibilities for computational codes for criticality and burnup calculations of boiling water reactor fuel; Untersuchungen zu Validierungsmoeglichkeiten von Rechencodes fuer Kritikalitaets- und Abbrandrechnungen von Siedewasserreaktor-Brennstoff

    Energy Technology Data Exchange (ETDEWEB)

    Behler, Matthais; Hannstein, Volker; Kilger, Robert; Sommer, Fabian; Stuke, Maik

    2017-06-15

    The Application of the method of Burn-up Credit on Boiling Water Reactor fuel is much more complex than in the case of Pressurized Water Reactors due to the increased heterogeneity and complexity of the fuel assemblies. Strongly varying enrichments, complex fuel assembly geometries, partial length fuel rods, and strong axial variations of the moderator density make the verification of conservative irradiation conditions difficult. In this Report, it was investigated whether it is possible to take into account the burn-up in criticality analyses for systems with irradiated Boiling Water Reactor fuel on the basis of freely available experimental data and by additionally applying stochastic methods. In order to achieve this goal, existing methods for stochastic analysis were adapted and further developed in order to being applicable to the specific conditions needed in Boiling Water Reactor analysis. The aim was to gain first insight whether a workable scheme for using burn-up credit in Boiling Water Reactor applications can be derived. Due to the fact that the different relevant quantities, like e.g. moderator density and the axial power profile, are strongly correlated, the GRS-tool SUnCISTT for Monte-Carlo uncertainty quantification was used in the analysis. This tool was coupled to a simplified, consistent model for the irradiation conditions. In contrast to conventional methods, this approach allows to simultaneously analyze all involved effects.

  13. Dynamic modelling as an element of the availibility and process oriented behaviour investigation of complex power plants; Dynamische Modellbildung als Element von verfuegbarkeits- und prozessorientierten Untersuchungen komplexer kraftwerkstechnischer Systeme

    Energy Technology Data Exchange (ETDEWEB)

    Klatt, M.

    2007-12-20

    A software-tool was developed, which, with its specially built component library, allows the modelling of availability and dynamic behaviour of large scale power plant units. The requested graphic representation near to the process flow schema required a search for new ways of data and information flow modelling. The large quantity of components of a power plant unit with its most important components thereby requires a block oriented modelling approach based on lumped and distributed lumped parameters. (orig.)

  14. Mathematical studies and measurements of the influence of the heat conductivity of mortar on the thermal resistance of brick walls. Pt. 2. Rechnerische und messtechnische Untersuchungen ueber den Einfluss der Waermeleitfaehigkeit des Moertels auf den Waermedurchlasswiderstand von Mauerwerk. T. 2

    Energy Technology Data Exchange (ETDEWEB)

    1983-01-01

    The equivalent thermal conductivity of hollow block walls - using different kinds of mortar - was calculated as a factor of the thermal conductivity of the stone for ten different types of hollow stone. Improved dimensions were developed for brickwork with light-weight mortar as compared to brickwork connected with normal mortar. Depending on the stone dimensioning and type of stone the improvement of thermal conductivity lies between 0,03 W(mxK) and 0,07 W/(mxK) given a thermal conductivity of mortar of 0,30 W(mxK). If the latter is 0,15 W(mxK) it comes down to between 0,04 W(mxK) and 0,09 W(mxK).

  15. Christine Löw: Frauen aus der Dritten Welt und Erkenntniskritik? Die postkolonialen Untersuchungen von Gayatri C. Spivak zu Globalisierung und Theorieproduktion. Sulzbach im Taunus: Ulrike Helmer Verlag 2009.

    Directory of Open Access Journals (Sweden)

    Heike Kahlert

    2011-07-01

    Full Text Available Christine Löw setzt sich in ihrer politikwissenschaftlichen Dissertation mit dem postkolonial-feministischen Denken Gayatri C. Spivaks auseinander und zielt in ihren sorgfältigen, überwiegend affirmativen Ausführungen darauf, Spivaks Überlegungen für die Politikwissenschaft nutzbar zu machen. Hierzu diskutiert sie deren theoretische Verortung in kritischen Ansätzen von Marxismus, Feminismus und Dekonstruktion sowie ihre Reflexionen zur epistemischen Gewalt westlichen Denkens gegenüber dem Süden und illustriert ihre Thesen zur Subalternität an vier ausgewählten politischen Themenfeldern. Zentrale Verdienste des Buches liegen darin, Spivaks Arbeiten in den deutschsprachigen sozialwissenschaftlichen Kontext einzuschreiben und weiterführende Forschungsfragen zu Globalisierung und Erkenntnisproduktion aufzuwerfen.Christine Löw’s dissertation (in the field of Political Science examines Gayatri C. Spivak’s postcolonial-feminist thinking. In her careful, mainly affirmative explanations she aims at utilizing Spivak’s considerations for Political Science. To this end, she discusses their theoretical position within critical approaches of Marxism, feminism, and deconstruction as well as her reflections on epistemic violence of western thinking against the south while also illustrating her theses on subalternity with four selected political topics. Situating Spivak’s works within the context of German-speaking social science and posing additional research questions on globalization and production of knowledge are the main achievements of this book.

  16. MRI of the fingers in patients with systemic scleroderma. Early results of contrast-enhanced examinations on a dedicated MRI system; MRT der Finger bei systemischer Sklerodermie. Erste Ergebnisse mit kontrastverstaerkten Untersuchungen an einem dedizierten MRT-System

    Energy Technology Data Exchange (ETDEWEB)

    Bonel, H.; Seemann, M.; Reiser, M. [Inst. fuer Radiologische Diagnostik, Klinikum Grosshadern, Univ. Muenchen (Germany); Messer, G.; Walchner, M.; Roecken, M. [Dermatologische Klinik und Poliklinik, Univ. Muenchen (Germany)

    1997-10-01

    Purpose. To estimate disease activity in patients with systemic sclerosis using contrast-enhanced MRI of the skin. Material and Methods. In a pre-study, sequences of a low-field (0.2 T) scanner (Artoscan, Esaote, Genova, Italy) were optimized for detection of intravenous contrast (0.1 mmol/l Gd-DTPA) in six patients with the autoimmune disease systemic scleroderma. Based on the results of the pre-study, 17 patients with scleroderma (7 sclerotic/10 active inflammatory disease) were scanned using gradient-spoiled 3D GRE sequences (FA 90 , TR 100 ms, TE 18 ms), which had been established as most sensitive for intravenous contrast. Contrast enhancement of the skin was determined quantitatively by contrast-to-noise ratios (CNR), comparing post- to pre-contrast and dynamic scans (for 6 min, 1 acquisition/min). Patients in the chronic state with sclerodactylia and active inflammation of the hands were considered separately and compared to a control group (n=10) matched according to age. Results. CNR increase after intravenous contrast was significantly higher in patients with active disease (86{+-}16% increase) than sclerosing disease (29{+-}3%, p<0.05) and the control group (4{+-}2%, p<0.05). The dynamic examination showed a significantly slower decrease after the peak rise in the first minute in patients with active disease (CNR 15.4{+-}0.7 to 14.2{+-}1.4) than in those with chronic disease (14.1{+-}0.5 to 11.3{+-}0.9, p<0.05). (orig.) [Deutsch] Zielsetzung der Arbeit war die Quantifizierung der Entzuendungsreaktion der Haut bei an systemischer Sklerodermie erkrankten Patienten mittels kontrastverstaerkter MRT. Material und Methoden. In einer Vorstudie mit 6 Patienten wurden die Sequenzen eines dedizierten Niederfeldmagnetresonanztomographen (Artoscan, Esaote, Genua, Italien) fuer den Kontrastmittelnachweis (0,1 mmol/l Gd-DTPA i.v.) optimiert. Basierend auf dieser Sequenzoptimierung wurden 17 Patienten mit systemischer Sklerodermie (7 Patienten mit sklerosierender, 10 mit aktiv-oedematoeser Erkrankung) mit einer 3D GRE-Sequenz mit Gradientenspoiler untersucht (FA 90 , TR 100 ms, TE 18 ms). Kontrast-zu-Rausch-Verhaeltnisse (CNR) von nativen und kontrastverstaerkten statischen (6 min) und dynamischen (ueber 6 min, 6mal 1 min) Sequenzen ermoeglichten die Quantifizierung der Anreicherung der Kutis. Patienten in der chronischen Phase mit Sklerodaktylie und der oedematoesen Phase der systemischen Sklerose sowie eine alterskorrelierten Kontrollgruppe (n=10) wurden getrennt ausgewertet und verglichen. Ergebnisse: Kontrast-zu-Rausch-Verhaeltnisse von nativen im Vergleich zu kontrastverstaerkten Sequenzen zeigten eine signifikant staerkere Anreicherung bei Patienten mit aktiv-oedematoeser Erkrankung im Vergleich zu Patienten in der sklerosierenden Phase der Erkrankung (86{+-}16% und 29{+-}3%, p<0,05) und im Vergleich zur Kontrollgruppe (4{+-}2%, p<0,05). Die dynamische Untersuchung zeigte einen signifikant langsameren Abfall des Kurvenverlaufs nach dem Maximum in der ersten Minute bei Patienten mit aktiv-oedematoeser (CNR: 15,4{+-}0,7 auf 14,2{+-}1,4) im Vergleich zur chronisch-sklerosierenden Erkankung (CNR: 14,1{+-}0,5 auf 11,3{+-}0,9, p<0,05). (orig.)

  17. Fluorescence microscopical studies on chitin distribution in the cell wall of giant cells of Saccharomyces uvarum, grown following X-radiaiton treatment. Fluoreszenzmikroskopische Untersuchungen zur Chitinverteilung in der Zellwand von Riesenzellen von Saccharomyces uvarum, gewachsen nach Roentgenbestrahlung

    Energy Technology Data Exchange (ETDEWEB)

    Hoschka, L

    1982-01-01

    Teast cells are synchronized and modiated with X-rays (1.0 kGy) in the Cr, phase. Their growth behaviour is observed in suspension cultures and the formation of giant cells noted. The chitin structures are selectively stained with the fluorescent dye Calcofluor white. In the unradiated cells the chitin is deposited at the bud constriction site in the form of rings in the mother cell wall, whereas for irradiated cells only one chitin ring of normal appearance is formed between the mother cell and first bud equivalent. Between further bud equivalents an intensification of fluorescence is occasionally noted, however the organisation of the chitin into a regular ring arrangement is disturbed. In giant cells the facility for primary and secondary septa formation is missing and these are essential for successful cell division. By further experiments it was possible to identify the cause of disturbance in the cell cycle of irradiated cells. Giant cells only form one chitin ring because its DNA is replicated one time only. The major cause triggering the actual formation of giant cells must be considered the missing distribution of the once-rephicated DNA. All processes in the cell cycle dependent on this step are therefore stopped and only bud formation which occurs independently continues along its rhytmical path.

  18. Fluorescence microscopical studies on chitin distribution in the cell wall of giant cells of Saccharomyces uvarum, grown following X-radiation treatment. Fluoreszenzmikroskopische Untersuchungen zur Chitinverteilung in der Zellwand von Riesenzellen von Saccharomyces uvarum, gewachsen nach Roentgenbestrahlung

    Energy Technology Data Exchange (ETDEWEB)

    Hoschka, L

    1982-01-01

    Yeast cells are synchronized and modiated with X-rays (1.0 kGy) in the Cr, phase. Their growth behaviour is observed in suspension cultures and the formation of giant cells noted. The chitin structures are selectively stained with the fluorescent dye Calcofluor white. In the unradiated cells the chitin is deposited at the bud constriction site in the form of rings in the mother cell wall, whereas for irradiated cells only one chitin ring of normal appearance is formed between the mother cell and first bud equivalent. Between further bud equivalents an intensification of fluorescence is occasionally noted, however the organisation of the chitin into a regular ring arrangement is disturbed. In giant cells the facility for primary and secondary septa formation is missing and these are essential for successful cell division. By further experiments it was possible to identify the cause of disturbance in the cell cycle of irradiated cells. Giant cells only form one chitin ring because its DNA is replicated one time only. The major cause triggering the actual formation of giant cells must be considered the missing distribution of the once-rephicated DNA. All processes in the cell cycle dependent on this step are therefore stopped and only bud formation which occurs independently continues along its rhythmical path.

  19. Results of the Austrian CT dose study 2010. Typical effective doses of the most frequent CT examinations; Ergebnisse der Oesterreichischen CT-Dosisstudie 2010. Effektive Dosen der haeufigsten CT-Untersuchungen und Unterschiede zwischen Anwendern

    Energy Technology Data Exchange (ETDEWEB)

    Homolka, Peter; Leithner, Robert; Billinger, Jochen [Medizinische Universitaet Wien (Austria). Zentrum fuer Medizinische Physik und Biomedizinische Technik; Gruber, Michael [Medizinische Universitaet Wien (Austria). Universitaetsklinik fuer Radiologie und Nuklearmedizin

    2014-10-01

    Purpose: To determine typical doses from common CT examinations of standard sized adult patients and their variability between CT operators for common CT indications. Materials and Methods: In a nationwide Austrian CT dose survey doses from approx. 10,000 common CT examinations of adults during 2009 and 2010 were collected and 'typical' radiation doses to the 'average patient', which turned out to have 75.6 kg body mass, calculated. Conversion coefficients from DLP to effective dose were determined and effective doses calculated according to ICRP 103. Variations of typically applied doses to the 'average patient' were expressed as ratios between 90{sup th} and 10{sup th} percentile (inter-percentile width, IPW90/10), 1st and 3{sup rd} quartile (IPW75/25), and Maximum/Minimum. Results: Median effective doses to the average patients for standard head and neck scans were 1.8 mSv (cervical spine), 1.9 mSv (brain: trauma/bleeding, stroke) to 2.2 mSv (brain: masses) with typical variation between facilities of a factor 2.5 (IPW90/10) and 1.7 (IPW75/25). In the thorax region doses were 6.4 to 6.8 mSv (pulmonary embolism, pneumonia and inflammation, oncologic scans), the variation between facilities was by a factor of 2.1 (IPW90/10) and 1.5 (IPW75/25), respectively. In the abdominal region median effective doses from 6.5 mSv (kidney stone search) to 22 mSv (liver lesions) were found (acute abdomen, staging/metastases, lumbar spine: 9-12 mSv; oncologic abdomen plus chest 16 mSv; renal tumor 20 mSv). Variation factors between facilities were on average for abdominal scans 2.7 (IPW90/10) and 1.8 (IPW75/25). Conclusion: Variations between CT operators are generally moderate for most operators, but in some indications the ratio between the minimum and the maximum of average dose to the typical standard patients exceeds a factor of 4 or even 5. Therefore, comparing average doses to Diagnostic Reference Levels (DRLs) and optimizing protocols need to be encouraged. (orig.)

  20. Clinical investigations on the use of positron emission tomography (PET) for target volume definition in radiation therapy planning; Klinische Untersuchungen zum Einsatz der Positronen-Emissions-Tomographie (PET) in der Zielvolumendefinition bei der Bestrahlungsplanung

    Energy Technology Data Exchange (ETDEWEB)

    Steffen, Ingo G.

    2014-12-05

    The aim of the present study was to evaluate the clinical value of positron emission tomography (PET) for target volume definition in different tumor entities using different tracers and taking pretreatment of patients into account. The study collective comprised 109 patients with 112 target volumes. In 48 patients with skull base meningiomas (SBM) and 42 patients with meningiomas of other localizations (SOM) undergoing fractionated stereotactic radiation therapy the gross tumor volumes (SBM, n=48; SOM, n=39) based on magnetic resonance imaging/computed tomography (MRI/CT) and {sup 68}Ga-DOTATOC-PET were compared retrospectively. Additionally, in 19 patients with liver metastasis from colorectal cancer (LM-CRC) treated in 25 CT guided brachytherapy sessions the clinical target volumes (CTV) either based on MRI/CT or {sup 18}F-FDG-PET were compared retrospectively. The spatial agreement of the target volumes was analyzed using the Dice similarity coefficient (DSC). The association of DSC, tumor entity and pretreatment was analyzed using the general linear model (GLM). Metric parameters are given as median (25th/75th-quartile). In the complete patient sample the PET based target volume was 24.1 (10.8/51.2) ml and, thus, significantly (p<0.001) increased by 18.9% (-3.6%/62.7%) compared to the MRI/CT based target volume of 20.8 (8.6/45.0) ml. In the subgroup of LM-CRC, the PET based target volume was significantly increased by 24.4% (0%/ 71.4%; p=0.021), and in patients with SBM it was increased by 23.9%(-1.7%/65.7%; p=0.003) whereas in SOM the difference of 8.0% (-3.6%/51.7%; p=0.199) was not significant. The DSC for PET and MRI/CT based target volumes was 0.66 (0.46/0.76) in the whole study group and varied between 0.65 (0.46/0.71) in patients with SBM and 0.70 (0.40/0.79) in patients with SOM. In pre-treated patients with LM-CRC a significant lower DSC of 0.62 (0.41/0.66) was observed in comparison to 0.84 (0.70/0.96) in untreated patients (significant interaction in GLM, p<0.001). In contrast, in patients with SBM and SOM no significant effect of pretreatment was observed. LM-CRC-patients with incomplete dose coverage of the PET-CTVs (<95%) showed a significant higher local 9-month-progression rate (9/15 vs. 1/3; p<0.05) by retrospective analysis. The target volumes either based on PET or MRI/CT showed clinically relevant differences with respect to size and overlap (DSC<0.7) for all the analyzed tumor entities. The association of target volume agreement and pretreatment varied between different tumor entities (significant interactions). As incomplete dose coverage of PET-CTVs in colorectal liver metastasis was indicative of early onset of local progression, the use of PET in target volume definition may be associated with improved local tumor control as well as improved patient survival. Prospective studies with sufficiently high patient numbers are required to verify this hypothesis.

  1. Spectroscopic and thermodynamic studies on the complexation of trivalent curium with inorganic ligands at increased temperatures; Spektroskopische und thermodynamische Untersuchungen zur Komplexierung von trivalentem Curium mit anorganischen Liganden bei erhoehten Temperaturen

    Energy Technology Data Exchange (ETDEWEB)

    Skerencak, Andrej

    2010-05-11

    The subject of the present investigation is the complexation of trivalent actinides at elevated temperatures. The objective of this work is to broaden the comprehension of the geochemical processes relevant for the migration of radionuclides in the near-field of a nuclear waste repository. Depending on the disposed nuclear waste, the temperature in the direct vicinity of a nuclear waste repository may reach up to 200 C. The result is a distinct change of the geochemistry of the actinides. Many of these processes have already been studied in detail at room temperature. Yet, data at elevated temperature are rare. However, a comprehensive long term safety analysis of a nuclear waste repository requires the precise thermodynamic description of the relevant geochemical processes at room as well as at elevated temperatures. The present work is focused on the investigation of the complexation of trivalent curium (Cm(III)) with different inorganic ligands at elevated temperatures. Due to its outstanding spectroscopic properties, Cm(III) is chosen as a representative for trivalent actinides. The studied ligand systems are nitrate (NO{sub 3}{sup -}), fluoride (F{sup -}), sulphate (SO{sub 4}{sup 2-}) and chloride (Cl{sup -}). The main analytical method employed is the ''time resolved laser fluorescence spectroscopy'' (TRLFS). The experiments with nitrate, sulphate and chloride were carried out in a custom-built high temperature cell, enabling spectroscopic studies at temperatures up to 200 C. The Cm(III)-fluoride-system was studied in a cuvette (quartz glass) in the temperature range from 20 to 90 C. Supplementary structural studies were performed using EXAFS (Extended X-Ray Absorption Fine Structure) spectroscopy and supported by quantum chemical calculations at DFT (Density Functional Theory) level. The results of the TRLFS studies show a general shift of the chemical equilibrium towards the complexed species with increasing temperature. For instance, the complexes Cm(NO{sub 3}){sub 2}{sup -} and Cm(SO{sub 4}){sub 3}{sup 3-} are formed only to a minor extent at room temperature, but are the dominating species of the according system at 200 C. The Cm(III)-fluoride system shows a strong increase of the complexed species in the studied temperature range, as well. The CmF{sub 2}{sup +} complex is a minor species at 20 C, but its molar fraction exceeds 50% at 90 C and [F{sup -}]{sub eq} > 3.0 x 10{sup -3} m. With the speciation of the systems Cm(III)-nitrate, Cm(III)-fluoride and Cm(III)-sulphate, the temperature dependent conditional stability constants log K{sup '}{sub n}(T) of the stepwise formation of the according complexes were derived. Using the SIT (specific ion interaction theory) approach, the log K{sup '}{sub n}(T) values were extrapolated to zero ionic strength (I{sub m} = 0). The respective log K{sup 0}{sub n}(T) values show a distinct increase with increasing temperature. The magnitude of the increase depends on the individual system. The mathematical description of the temperature dependency of the respective log K{sup 0}{sub n}(T) values yielded the according thermodynamic constants. The results show that each here studied complexation reaction is entropy driven (positive reaction enthalpies (Δ{sub r}H{sup 0}{sub m}) and -entropies (Δ{sub r}S{sup 0}{sub m})), and explain thus the increase of the stability constants with increasing temperature. Another field of interest, which was attended to in this work, is the measurement of pH at elevated temperatures. The pH is one of the major factors of aquatic systems and its precise measurement is of vital importance for the quantitative description of complexation reactions. The applied method is based on the spectroscopic detection of the temperature- und pH-dependent equilibrium between the protonated and deprotonated form of an indicator dye (acridin, bromophenol blue and bromothymole blue). The experiments were performed also in a high temperature fluorescence cell, which was coupled to an UV/Vis-Spectrometer via two waveguides. Using this approach, the pH(T) of fluoride containing aquatic solutions were measured in the temperature range from 20 to 90 C und hence the free proton concentration ([H{sup +}]{sub eq}) was calculated. The experimentally derived values were in good agreement with calculated [H{sup +}]{sub eq} values. Hence, the temperature dependency of the Cm(III)-fluoride system can be well described with theoretical methods.

  2. Investigations of the transport behavior of contaminants in fresh water/brine systems under consideration of density differences; Untersuchungen zum Transportverhalten von Schadstoffen in Suess- / Salzwassersystemen unter Beruecksichtigung von Dichteunterschieden

    Energy Technology Data Exchange (ETDEWEB)

    Larue, Juergen; Weyand, Torben; Mayer, Kim-Marisa

    2016-10-15

    This report contains a compilation of national and international experience gathered as part of a research project sponsored by the BMUB concerning the aspect of the transport behaviour of contaminants in freshwater/brine systems with consideration of density and viscosity differences. The fundamentals of modelling density-dependent flows are presented and a series of examples of the application with different codes and their uses with reference to real sites is described. Besides an overview of test cases for the verification of these codes, the further development of the instruments available to GRS and test calculations regarding their implementation are presented.

  3. Balance of groundwaterstreams below dumps with the application of environmental isotopes within hydrogeological examinations. Final report; Bilanzierung von Grundwasserstroemen unter Deponien mit Hilfe von umweltisotopen-hydrologischen Analysen im Rahmen hydrogeologischer Untersuchungen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Geyh, M A; Ays, G

    1995-08-15

    The aim of the work was to test current environmental isotope techniques for their suitability in the risk assessment of abandoned sites and landfills in operation. Analyses of the environmental isotopes {sup 18}O, {sup 2}H, {sup 13}C and {sup 3}H were made in order to follow up the pollutant plumes and, where possible, forecast their development regarding space and time. Hydrochemical results served as references.- The working hypothesis of the project was as follows: leachates from landfills may have a labelling that differs from the natural isotope composition and is characterized by the content of the landfill and isotope fractionations occurring during its degradation. The isotope values of the groundwater upstream and downstream of landfills were measured at different seasons in order to record natural and anthropogenous changes of isotope compositions in the area of the landfill. It was expected that the mobility of the chemical contaminants would be impaired by physical, chemical and biological retardation as compared with that of the isotope-labelled water molecules.- By means of the oxygen and carbon isotope composition of leachate, areas downstream of sanitary landfills that are influenced by them in different degrees can be delimited from each other. Carbon isotope composition can be used to follow up the phases of the chemical degradation of organic constituents. In hazardous waste landfills, there occur special isotope effects that are to be explained by the different composition of the material. (orig.) [Deutsch] Ziel war es, die ueblichen Umweltisotopen-Techniken auf ihre Eignung bei der Risikobewertung von Altlasten und Deponien zu ueberpruefen. Dazu wurden Analysen der Umweltisotope {sup 18}O, {sup 2}H, {sup 13}C und {sup 3}H eingesetzt, um Schadstoffahnen zu verfolgen und ggfs. deren raeumliche und zeitliche Entwicklung vorherzusagen. Als Referenz dienten hydrochemische Ergebnisse. Die Arbeitshypothese des Forschungsvorhabens war, dass Deponiesickerwaesser eine von der natuerlichen Isotopenzusammensetzung abweichende Markierung haben koennten, die vom Deponieinhalt und Isotopen-Fraktionierungen bei dessen Abbau gepraegt ist. Die Isotopenwerte des Grundwassers ober- oder unterstrom der Deponien wurden zu verschiedenen Jahreszeiten gemessen, um natuerliche und anthropogene Veraenderungen der Isotopenzusammensetzungen im Deponiebereich zu erfassen. Es wurde erwartet, dass die Mobilitaet der chemischen Kontaminanten durch physikalische, chemische und biologische Retardation gegenueber der der isotopisch markierten Wassermolekuele eingeschraenkt sei. Im Abstrom von Hausmuelldeponien koennen mit Hilfe der Sauerstoff- und Kohlenstoff-Isotopenzusammensetzung im Sickerwasser unterschiedlich stark von der Deponie beeinflusste Bereiche voneinander abgegrenzt werden. Die Kohlenstoff-Isotopenzusammensetzung kann zur Verfolgung der Phasen des chemischen Abbaus organischer Inhaltsstoffe eingesetzt werden. In Sonderabfalldeponien treten spezielle Isotopen-Effekte auf, die mit der andersartigen Zusammensetzung der Inhaltsstoffe zu erklaeren sind. (orig.)

  4. Climate data and climate change - Analysis of the influence on energy demand, performance requirement and thermal comfort of buildings; Klimadaten und Klimawandel - Untersuchungen zum Einfluss auf den Energiebedarf, den Leistungsbedarf und den thermischen Komfort von Gebaeuden

    Energy Technology Data Exchange (ETDEWEB)

    Voss, Karsten; Kuenz, Carolin [Bergische Universitaet Wuppertal (Germany)

    2012-10-15

    Continuous research on climate change has improved the knowledge on climate forecast modelling, so that local and regional climate data sets for the application in building energy modelling are available. The paper analyses the data sets of most known sources and compares the relevant characteristics at four German locations. Simulation results for three commercial building examples (office, school and hotel) illustrate how the climate change may influence heating and cooling demands and capacities as well as the summer thermal comfort if no adjustments with respect to construction, service technology and user behaviour are applied. A significant decrease in space heating demand is contrasted by increased cooling demand and increased indoor temperatures during summer even until 2050. Especially for the office buildings, the summer conditions develop critical, so that active cooling will be mandatory in the summer hot regions. This trend was already detected during the past decade. The forecast is critical for all existing buildings. Significant improvements of the envelope properties such as glazing or shading and passive cooling options become mandatory. The changes predicted for schools and hotels remain moderate.

  5. Radioecological studies of agricultural floodplain of the Mulde River on the consequences of the former uranium mining; Radiooekologische Untersuchungen landwirtschaftlich genutzter Auen der Mulde zu den Folgen des ehemaligen Uranbergbaus

    Energy Technology Data Exchange (ETDEWEB)

    Bister, Stefan

    2012-12-18

    At the time of Warsaw Pact, the former German Democratic Republic (GDR) was one of the largest producer of uranium in the world and the most important supplier of uranium for the USSR. The former Saxon uranium mining areas are drained by the Zwickauer Mulde River. The Mulde River is a left side tributary or the Elbe River and mainly situated in Saxony. The frontal flows, Freiberger Mulde River and Zwickauer Mulde River, merge close to the small village of Sermuth to form the Vereinigte Mulde River, which flows into the Elbe River near Dessau. This research project was established to quantify the long-term effect of the former uranium mining activities on the floodplain ecosystem of the Mulde River. The radiological impact from the agricultural use of the alluvial soils was investigated. More than 280 samples from different environmental compartments (river water, surface sediment from the river, alluvial soils and agricultural crops) were sampled and analysed by radiometric methods. All of the compartments still show an impact from the former uranium mining. However, comparisons with earlier measurements reveal a considerable decrease of the radionuclide contamination. Thus, it is not possible to relate the activities in the soil samples to the activities of the water and sediment samples measured in parallel. Radionuclides originating from the alluvial soils enter the human food chain as a result of the agricultural use of the floodplains. Yet, the radiological effect is small. The uranium contamination of the river water results in activity values lying beyond the threshold of the current German Drinking Water Ordinance. Dose calculations based on the ''Berechnungsgrundlage Bergbau'' [BGB10] do not exceed the guidance level of 1 mSv additional potential radiation exposure per year for the current agricultural use, even assuming most disadvantageous conditions.

  6. Development of the neutron-transport code TransRay and studies on the two- and three-dimensional calculation of effective group cross sections; Entwicklung des Neutronentransportcodes TransRay und Untersuchungen zur zwei- und dreidimensionalen Berechnung effektiver Gruppenwirkungsquerschnitte

    Energy Technology Data Exchange (ETDEWEB)

    Beckert, C.

    2007-12-19

    Conventionally the data preparation of the neutron cross sections for reactor-core calculations pursues with 2D cell codes. Aim of this thesis was, to develop a 3D cell code, to study with this code 3D effects, and to evaluate the necessarity of a 3D data preparation of the neutron cross sections. For the calculation of the neutron transport the method of the first-collision probabilities, which are calculated with the ray-tracing method, was chosen. The mathematical algorithms were implemented in the 2D/3D cell code TransRay. For the geometry part of the program the geometry module of a Monte Carlo code was used.The ray tracing in 3D was parallelized because of the high computational time. The program TransRay was verified on 2D test problems. For a reference pressured-water reactor following 3D problems were studied: A partly immersed control rod and void (vacuum or steam) around a fuel rod as model of a steam void. All problems were for comparison calculated also with the programs HELIOS(2D) and MCNP(3D). The dependence of the multiplication factor and the averaged two-group cross section on the immersion depth of the control rod respectively of the height of the steam void were studied. The 3D-calculated two-group cross sections were compared with three conventional approximations: Linear interpolation, interpolation with flux weighting, and homogenization, At the 3D problem of the control rod it was shown that the interpolation with flux weighting is a good approximation. Therefore here a 3D data preparation is not necessary. At the test case of the single control rod, which is surrounded by the void, the three approximation for the two-group cross sections were proved as unsufficient. Therefore a 3D data preparation is necessary. The single fuel-rod cell with void can be considered as the limiting case of a reactor, in which a phase interface has been formed. [German] Standardmaessig erfolgt die Datenaufbereitung der Neutronenwirkungsquerschnitte fuer Reaktorkernrechnungen mit 2D-Zellcodes. Ziel dieser Arbeit war es, einen 3D-Zellcode zu entwickeln, mit diesem Code 3D-Effekte zu untersuchen und die Notwendigkeit einer 3D-Datenaufbereitung der Neutronenwirkungsquerschnitte zu bewerten. Zur Berechnung des Neutronentransports wurde die Methode der Erststosswahrscheinlichkeiten, die mit der Ray-Tracing-Methode berechnet werden, gewaehlt. Die mathematischen Algorithmen wurden in den 2D/3D-Zellcode TransRay umgesetzt. Fuer den Geometrieteil des Programms wurde das Geometriemodul eines Monte-Carlo-Codes genutzt. Das Ray-Tracing in 3D wurde auf Grund der hohen Rechenzeiten parallelisiert. Das Programm TransRay wurde an 2D-Testaufgaben verifiziert. Fuer einen Druckwasser-Referenzreaktor wurden folgende 3D-Probleme untersucht: Ein teilweise eingetauchter Regelstab und Void (Vakuum oder Dampf) um einen Brennstab als Modell einer Dampfblase. Alle Probleme wurden zum Vergleich auch mit den Programmen HELIOS (2D) und MCNP (3D) nachgerechnet. Die Abhaengigkeit des Multiplikationsfaktors und der gemittelten Zweigruppenquerschnitte von der Eintauchtiefe des Regelstabes bzw. von der Hoehe der Dampfblase wurden untersucht. Die 3D berechneten Zweigruppenquerschnitte wurden mit drei ueblichen Naeherungen verglichen: Lineare Interpolation, Interpolation mit Flusswichtung und Homogenisierung. Am 3D-Problem des Regelstabes zeigte sich, dass die Interpolation mit Flusswichtung eine gute Naeherung ist. Demnach ist hier eine 3D-Datenaufbereitung nicht notwendig. Beim Testfall des einzelnen Brennstabs, der von Void umgeben ist, erwiesen sich die drei Naeherungen fuer die Zweigruppenquerschnitte als unzureichend. Demnach ist eine 3D-Datenaufbereitung notwendig. Die einzelne Brennstabzelle mit Void kann als der Grenzfall eines Reaktors angesehen werden, in dem sich eine Phasengrenzflaeche herausgebildet hat. (orig.)

  7. Generic safety questions. evaluation of investigations, studies and expertises of other states for the knowledge base GeSi; Generische Sicherheitsfragen. Auswertung von Untersuchungen, Studien und Gutachten anderer Staaten fuer die Wissensbasis GeSi

    Energy Technology Data Exchange (ETDEWEB)

    Boenigke, Guenther; Eismar, Shanna

    2016-03-15

    For the non-profit-making expert organization Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) gGmbH, maintaining know-how and broadening its knowledge in the field of nuclear safety is of fundamental relevance. One important approach to achieving this goal is to collect and assess national and international findings and events in the field of nuclear safety e.g. in connection with generic issues - i.e. issues that are not specific to a particular plant. The GeSi/GeSi International database and its subsystems serves for reflecting the current state of the art in science and technology in the field of generic issues and also as a tool in the area of knowledge management. Within the framework of Project 3611 I 01500 sponsored by the BMUB, information on these issues was compiled systematically. The aim of the project was to examine the safety issues that are cur-rently discussed at national and international level with regard to their relevance for the conditions prevailing in Germany and to follow up in detail those issues that are of relevance for national safety practice. Similar knowledge databases also exist in other major nuclear-power-plant-operating countries such as the US, Canada, and France. At present (September 2014), there are 303 issues in the overall database, of which 23 are assessed to be of ''high'' significance for German plants. Of these, 16 issues belong to the sub-database for generic safety issues (GSI) and seven belong to the sub-database for generic research issues (GFO). The database GSI currently contains 138 issues that need to be further addressed and 101 issues that are considered as solved. 43 issues from the database GFO require further investigation, while 21 issues are considered as solved.

  8. Investigations on the effects of ``Ecstasy`` on cerebral glucose metabolism: an 18-FDG PET study; Untersuchungen zum Einfluss von ``Ecstasy`` auf den zerebralen Glukosemetabolismus: eine 18-FDG-PET-Studie

    Energy Technology Data Exchange (ETDEWEB)

    Schreckenberger, M.; Sabri, O.; Arning, C.; Tuttass, T.; Schulz, G.; Kaiser, H.J.; Wagenknecht, G.; Buell, U. [Klinik fuer Nuklearmedizin, Universitaetsklinik, RWTH Aachen (Germany); Gouzoulis-Mayfrank, E.; Sass, H. [Klinik fuer Psychiatrie, Universitaetsklinikum, RWTH Aachen (Germany)

    1998-12-31

    Purpose: The aim of the present study was to determine the acute effects of the `Ecstasy` analogue MDE (3,4-methylendioxyethamphetamine) on the cerebral glucose metabolism (rMRGlu) of healthy volunteers. Method: In a randomised double-blind trial, 16 healthy volunteers without a history of drug abuse were examined with 18-FDG PET 110-120 minutes after oral administration of 2 mg/kg MDE (n=8) or placebo (n=8). Beginning two minutes prior to radiotracer injection, a constant cognitive stimulation was maintained for 32 minutes using a word repetition paradigm in order to ensure constant and comparable mental conditions during cerebral 18-FDG uptake. Individual brain anatomy was represented using T1-weighted 3D flash MRI, followed by manual regionalisation into 108 regions-of-interest and PET/MRI overlay. Absolute quantification of rMRGlu and comparison of glucose metabolism under MDE versus placebo were performed using Mann-Whitney U-test. Results: Absolute global MRGlu was not significantly changed under MDE versus placebo (MDE: 41,8{+-}11,1 {mu}mol/min/100 g, placebo: 50,1{+-}18,1 {mu}mol/min/100 g, p=0,298). The normalised regional metabolic data showed a significantly decreased rMRGlu in the bilateral frontal cortex: Left frontal posterior (-7.1%, p<0.05) and right prefrontal superior (-4.6%, p<0.05). On the other hand, rMRGlu was significantly increased in the bilateral cerebellum (right: +10.1%, p<0.05; left: +7.6%, p<0.05) and in the right putamen (+6.2%, p<0.05). Conclusions: The present study revealed acute neurometabolic changes under the `Ecstasy` analogon MDE indicating a fronto-striato-cerebellar dysbalance with parallels to other psychotropic substances and various endogenous psychoses respectively. (orig.) [Deutsch] Ziel: In der vorliegenden Studie sollte die Akutwirkung des `Ecstasy`-Analogons MDE (3,4-Methylendioxyethamphetamin) auf den zentralen Glukosemetabolismus (rMRGlu) gesunder Probanden untersucht werden. Methode: In einer randomisierten Doppelblindstudie wurden 16 gesunde Probanden ohne Drogenanamnese mittels 18-FDG-PET 110-120 min nach oraler Verabreichung von 2 mg/kg KG MDE (n=8) oder Placebo (n=8) untersucht. Zwei Minuten vor Injektion des Radiopharmazeutikums startend erfolgte ueber insgesamt 32 min eine konstante kognitive Stimulation ueber ein Wortrepetitionsparadigma, um konstante und vergleichbare mentale Bedingungen waehrend der zerebralen 18-FDG-Aufnahme zu gewaehrleisten. Die Darstellung der Individualanatomie erfolgte anhand T1-gewichteter 3D-flash MRT mit anschliessender manueller Regionalisierung in 108 Regions-of-Interest und PET/MRT Overlay. Absolute Quantifizierung der rMRGlu sowie Normierung auf den Globalmetabolismus mit anschliessendem Vergleich MDE versus Placebo mittels U-Test nach Mann und Whitney. Ergebnisse: Gegenueber der Placebo-Gruppe fand sich unter MDE keine signifikante Aenderung der globalen MRGlu (MDE: 41,8{+-}11,1 {mu}mol/min/100 g, Placebo: 50,1{+-}18,1 {mu}mol/min/100 g, p=0,298). Die normierten metabolischen Daten zeigten eine signifikante Minderung der rMRGlu im beidseitigen Frontalkortex: Links frontal posterior (-7,1%, p<0,05) und rechts praefrontal superior (-4,6%, p<0,05). Signifikante Steigerungen der rMRGlu fanden sich dagegen im beidseitigen Zerebellum (rechts: +10,1%, p<0,01; links: +7,6%, p<0,05) sowie im rechten Putamen (+6,2%, p<0,05). Schlussfolgerung: In der vorliegenden Studie konnten unter dem Akuteinfluss des `Ecstasy`-Analogons MDE neurometabolische Veraenderungen im Sinne einer fronto-striato-cerebellaeren Dysbalance nachgewiesen werden, die parallelen zu sowohl anderen psychotropen Substanzen als auch verschiedenen endogenen Psychosen aufweisen. (orig.)

  9. Investigations to the reduction of the drying time of temperature sensitive goods with assistance of sorbents. Final report; Untersuchungen zur Verkuerzung der Trocknungszeit temperaturempfindlicher Gueter unter Verwendung von Sorptionsmitteln. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Coutelle, R.

    1998-07-31

    It was the aim of the project to improve the solar drying process with assistance of solar regenerated sorbents. Fruits, vegetables, herbs and mushrooms were dried in hurdles and calcium chloride solutions were concentrated in black plastic basins with solar energy during the day. At night or at bad meteorological conditions the hurdles with the drying goods were set into the basins and capped in order to continue the drying process. By this means a microbial decay was prohibited and the drying time was shortened roughly by half. (orig.) [Deutsch] Ziel des Vorhabens war es, den Prozess der solaren Trocknung mit Hilfe von solar regenerierten Sorptionsmitteln zu verbessern. Tagsueber wurden mit Solarenergie Fruechte, Gemuese, Kraeuter und Pilze in Horden getrocknet, und Calciumchloridloesungen wurden in schwarzen Kunststoffwannen regeneriert. Zur Fortsetzung der Trocknung waehrend der Nacht und bei unguenstigen Witterungsverhaeltnissen wurden die Horden mit den Trocknungsguetern in die Wannen gesetzt und abgedeckt. Durch dieses Verfahren konnte ein mikrobieller Verderb vermieden und die Trocknungszeit auf ca. die Haelfte verkuerzt werden. (orig.)

  10. Studies on the influence of ionising radiation on leukemogenesis using 1-N-n-butyl-1-nitroso-urea. Untersuchungen ueber den Einfluss von ionisierenden Strahlen auf die Leukaemogenese durch 1-N-n-Butyl-1-Nitroso-Harnstoff (BNU)

    Energy Technology Data Exchange (ETDEWEB)

    Bischof, S.

    1982-11-26

    Female BDF/sub 1/-mice were used for the study. Even a BNU-concentration which in comparison to other authors was reduced from 0.04 to 0.02%, caused in a 12-week application in the drinking water leukemia in 96% of the mice. Additional X-radiation of 12x50 R and 4x100 R had no influence on the death rate. On the other hand, 12x25 R doses caused a significant acceleration and 12x75 R a significant delay in leukemogenesis by BNU. The leukemia incidence was not changed. The number of ETL increased in the groups with BNU and irradiation with the received radiation doses, whereas it decreased in the groups which were only irradiated. The groups which were only irradiated showed an increase in leukemia incidence with the received total dose. In the groups which were only irradiated the number of CFU/sub S/ and the thymus weight near the end of irradiation showed a good correlation with the leukemia incidence. In the groups with BNU and irradiation the superadditive effects in the collaboration of both noxae on immune status, thymus weight, and the stem cell number in the bone marrow and the spleen are confirmed. The extent of immunosuppression, bone marrow damage and thymus suppression is not correlated with the leukemia development.

  11. Adsorption, regeneration and reuse of activated carbon for elimination of COD from municipal waste water. Final report. Untersuchungen zur Aktivkohle-Adsorption, -Regeneration und Wiederverwendung beim Einsatz zur Elimination des CSB aus kommunalem Abwasser. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Sekoulov, I.; Holst, H.J.

    1994-02-01

    One practicability to reduce COD-loadings of secondary effluents is the activated carbon fixed bed-process. In this project activated carbons (GAC) of different raw products (peat, wood, coal) were loaded with filtrated municipal waste water (mean COD-concentration: 60 mg CSB/L). After the break-through of adsorption-colums, the carbon was regenerated by means of superheated steam (optimal conditions: [theta]=300 C, pressure=2 bar, thermal energie=10 KW). Regeneration experiments demonstrated, that the results of steam-treatment of GAC is independent in respects to the preloading of activated carbons and the raw products. The mass of COD, detected in the condensed (liquid) steam-phase, always was in quantity about 10% of the further COD adsorbed to the GAC. Gaseous reaction products could not evaluated by means of the experimental design. But former perculation cycles of steam-treated carbons and measurments of the specific area (BET-method) indicated, that the adsorption-capacity of regenerated GAC seams to be in the same quantity, than unloaded carbons. Measurements (GC/MS) of single organic components showed, that humic-substances are catalysed at steam temperatures about 300 C. It seams, that chlorinated hydrocarbons could formed by means of this regeneration method. BOD experiments demonstrated, that substances of the steam-treatment could be biological degraded about 50% to 60%. (orig.)

  12. Studies on the concentrations and enrichment of potentially phytotoxic organic pollutants in rain, cloud, and fogwater. Untersuchungen zum Vorkommen und zur Anreicherung potentiell phytotoxischer organischer Umweltgifte in der Nebeldeposition

    Energy Technology Data Exchange (ETDEWEB)

    Herterich, R.; Herrmann, R. (Bayreuth Univ. (Germany, F.R.). Lehrstuhl fuer Hydrologie)

    1989-07-01

    Measurements of organic pollutants in rain, cloud- and fogwater indicate that among other phytotoxic compounds especially nitrated phenols reach deposition rates which can possibly exert harmfull effects on vegetation. We present a highly efficient fogwater collector and a wet deposition sampler for the analysis of organic trace substances. Their arrangement for comparative wet deposition studies in the Alpes and the Fichtelgebirge is shown. Preliminary results show maximum fogwater contaminations up to 2 {mu}molx1{sup -1} for 4-nitrophenol and 4-nitrocresols including both pollutants. At highly exposed mountain sites deposition of these compounds into spruce stands via fogwater can reach several mgxm{sup -2} within a period of 10 days. (orig.).

  13. Investigations on the bioavailability of traffic-related platinum group elements (PGE) to the aquatic fauna with special consideration being given to palladium; Untersuchungen zur Bioverfuegbarkeit Kfz-emittierter Platingruppenelemente (PGE) fuer die aquatische Fauna unter besonderer Beruecksichtigung von Palladium

    Energy Technology Data Exchange (ETDEWEB)

    Sures, B.; Thielen, F.; Zimmermann, S. [Karlsruhe Univ. (T.H.) (Germany). Zoologisches Inst.

    2002-07-01

    The uptake and accumulation of the traffic-related platinum group elements (PGE) Pt, Pd and Rh by the aquatic fauna was investigated. Zebra mussels, eels and barbels were maintained in water containing either road dust or ground catalytic converter material. Following the exposure, samples of fish liver and kidney, as well as the soft tissues of the mussels, were analysed. Our results revealed that all three catalytic noble metals were accumulated by aquatic organisms. The highest bioavailability was found for Pd, followed by Pt and Rh. The concentration factor of Pd for Dreissena polymorpha was 5 times higher compared with Pb and only 6 times lower than the essential element Cu. With regard to the increasing emission of Pd the level of this metal has to be monitored very carefully in the environment. (orig.) [German] Die Aufnahme und Anreicherung der Kfz-buertigen Platingruppenelemente (PGE) Pt, Pd und Rh durch aquatische Tiere wurde an Dreikantmuscheln, Aalen und Barben untersucht. Hierzu wurden die Testorganismen in Wasser mit Strassenstaub einer stark befahrenen Strasse oder mit zerriebenem Autokatalysatormaterial ueber mehrere Wochen exponiert und anschliessend Leber und Niere der Fische sowie das Weichgewebe der Muscheln analysiert. Im Rahmen dieser Studien konnte nachgewiesen werden, dass alle drei Edelmetalle durch Fische wie durch Muscheln aufgenommen und angereichert werden. Fuer Pd fand sich die hoechste Bioverfuegbarkeit, gefolgt von Pt und Rh. Das Ausmass der Aufnahme von Pd durch Dreissena polymorpha war ca. 5fach hoeher als von Pb und 6fach niedriger verglichen mit dem essenziellen Element Cu. In Anbetracht der steigenden Emission von Pd sollte ein Umweltmonitoring die Verbreitung von Pd in der Umwelt klaeren. (orig.)

  14. Investigations of relevance of the tumor marker neopterine for therapeutic decision and control of progress in mammary carcinoma. Untersuchungen zur Relevanz des Tumormarkers Neopterin fuer die Therapieentscheidung und Verlaufskontrolle bei Mammakarzinom

    Energy Technology Data Exchange (ETDEWEB)

    Hacker, I; Lauterbach, H; Kob, D [Jena Univ. (German Democratic Republic). Radiologische Klinik und Poliklinik

    1989-01-01

    The value of serum neopterin as tumor marker was verified in 104 breast cancer patients. Based on the results the evaluation of neopterin cannot be recommended, neither for the decision of treatment after primary therapy nor for monitoring of the breast cancer. (author).

  15. Investigations about the structure of the transient diesel fuel injection jet near the nozzle with the method of radio-frequency cinematography. Untersuchungen zur Struktur des instationaeren Dieseloeleinspritzstrahles im Duesennahbereich mit der Methode der Hochfrequenz-Kinematografie

    Energy Technology Data Exchange (ETDEWEB)

    Eifler, W.

    1990-03-22

    Precise knowledge on the flow processes in interior of a fuel injector and of a diesel jet near the nozzle are required in order to reduce the pollutant emissions of a diesel engine through selective optimization of mixing. A radio-frequency cinematography system on the basis of a pulsed laser and streak camera was developed in order to make such flow processes visible. Transparent nozzle caps were used for isolation of the start parameters. The 'supercavitation' inside the nozzles, which in this way was made visible, continues far into the pressure chamber and governs the jet structure near the nozzle. The real diesel injection jet was examined subsequently systematically by different hydraulic start parameters. It was found out that in the case of all bag hole compressions that are relevant for mixing, the jet pattern is determined essentially through the protrusions resulting from implosion. First investigations about evaporation behavior pointed to a preferred ignition site in the marginal zone of the jet. (HWJ).

  16. Cu/sub x/S-CdS thin film solar cells - aftertreatment and stability. Cu/sub x/S-CdS Duennschicht-Solarzellen - Untersuchungen ueber die Nachbehandlung und die Stabilitaet

    Energy Technology Data Exchange (ETDEWEB)

    Pfisterer, F

    1987-02-19

    The performance of Cu/sub x/S-CdS thin film solar cells can be improved significantly by a secondary treatment of the Cu layer. The physical mechanisms underlying the aftertreatment process were investigated both experimentally and theoretically. A historical review is followed by an outline of the technology and theory of these solar cells (material properties, process engineering, photovoltaic properties) and a description of Cu aftertreatment and H glowing (experimental set-up, surface potential shift, electron beam scanning). Capacity measurements in this type of thin film cell are described (space charge profile, electrolytic decomposition, copper depletion between the contact web). Aftertreatment of the copper layer enhances the solar cell efficiency, stability, and productivity, makes the immersion process less tedious, and corrects the stoichiometry. (HWJ).

  17. Radiation exposure of the radiological staff caused by radiography of small mammals, reptiles and birds; Untersuchungen zur Strahlenexposition des radiologisch taetigen Personals bei der Radiographie von Heimtieren, Reptilien sowie Zier- und Wildvoegeln

    Energy Technology Data Exchange (ETDEWEB)

    Eckert, Yvonne

    2015-05-27

    Radiography is often used as an advanced examination to ensure a diagnosis in avian, reptiles and small mammal's medicine. The aims of this thesis were: 1. To measure the radiation exposure of radiological staff caused by radiography of small mammals, reptiles and birds. The exposure of relevant body regions were measured during clinical routine. 2. To examine the differences of radiation exposures caused by radiography of different animal species and to determine the influence of dose-dependent parameters. 3. To present the radiation protection measures of the clinic and to discuss possible improvements. 4. To weigh the anaesthetic risk for small mammals, reptiles and birds against the radiation exposure of the radiological staff. The measurements took place during clinical routine of the Clinic for Exotic Pets, Reptiles, Pet and Feral Birds, University of Veterinary Medicine Hannover, Foundation. The radiation exposure of the radiological staff was measured. The radiological staff included veterinarians, veterinary-medical technical assistants, doctoral candidates and students during their practical year. Furthermore, the radiation exposure was measured at ten representative body regions using thermoluminescence dosimetry. The measuring positions included the eye-lenses, thyroid, thoracic region under the protective clothes, thoracic region above the protective clothes, gonads, fingers and the left foot. Except for one position that was measured under the protective clothes all positions measured above the protective clothes. Moreover at each examination the focus-film-distance, the kV-number, the mAs-product and the weight of the patient was recorded. Additionally the size of the examiner and the examiner's position regarding to the X-ray table were recorded as variable, dose-influencing parameters. Altogether, measurements were taken from 366 individual examiners. In all three divisions 792 X-ray images were made and 3660 dose values recorded. The maximum measured doses were 11.4 μSv for the eye-lenses, 11.5 μSv for the thyroid, 5.67 μSv for the thoracic region under the lead apron, 3.47 μSv for the thoracic region above the lead apron, 1.86 μSv for the gonads, 182 μSv for the fingers and 2.05 μSv for the foot. The median of all dose values was 0.53 μSv. The analysis of the results showed that radiation exposure of staff during X-raying small mammals, reptiles and birds was very low. Dose values at the eye-lenses, thyroid region and the fingers were regularly measurable and were annotated. The most exposed body regions were the fingers, which were closest to the primary x-ray field during X-raying. All in all, the measured dose values were in the range of a few microsievert. There was no influence of dose-influencing-parameters on the dose. There was a slight, non-significant trend that heavier patients caused higher dose values because of more scattered radiation, and also a higher kV-number was correlated with an increase in dose rate. The comparison between measuring positions above and under the protection clothes showed that even the values measured above the protection clothes were low. Furthermore, the protective effect of protection clothes was pointed out. Therefore it is not necessary to optimize the radiation protection measures in the clinic. The results of the estimation of the annual radiation exposure of the radiological staff underlined that the exposure is well below the national dose limits for occupationally exposed persons. The conservative maximum effective dose amounted to less than 1 % of the civilizing radiation exposure of all citizens in Germany. Moreover the evaluation of the results concerning the anesthetic risk of the patients showed that routinely X-raying without any anesthesia is justifiable.

  18. The Eckert number phenomenon - experimental investigations of heat transfer on moving walls, e.g. rotating cylinders; Das Eckert-Zahl-Phaenomen - Experimentelle Untersuchungen zum Waermeuebergang an einer bewegten Wand am Modellfall eines rotierenden Zylinders

    Energy Technology Data Exchange (ETDEWEB)

    Gschwendtner, M.

    2000-07-01

    The Eckert number phenomenon - theoretically investigated by Geropp in 1969 - describes a turnover in heat transfer at a moving wall at an Eckert number EC=1. This report is the first to confirm the Eckert number phenomenon experimentally. Heat transfer on a heated, vertically rotating cylinder in a crossflow was investigated at extreme rotational speeds, i.e. in the range where the predicted phenomenon will occur. A heating concept had to be developed which allowed an input of heating power independent of rotational speed and which therefore had to be contact-free. The complex thermofluiddynamic processes in the boundary layer around the rotating cylinder were investigated and measured using predominantly optical measuring techniques. The results show that the temperature difference between the wall and the surrounding fluid had a significant effect on the predicted turnover of heat transfer at the wall. Moreover, maximum heat transfer occurs at an Eckert number Ec=0.3, which is of great importance for the cooling of hot surfaces in an airstream. [German] Das Eckert-Zahl-Phaenomen - von Geropp 1969 theoretisch untersucht - beschreibt den Umschlag des Waermeueberganges an einer bewegten Wand bei einer Eckert-ZahlEc{approx}1. In der vorliegenden Arbeit wird das Eckert-Zahl-Phaenomen zum ersten Mal experimentell bestaetigt. Dazu wurde der Waermeuebergang am Modellfall eines queransgestroemten, beheizten, vertikalrotierenden Zylinders untersucht. Aufgrund der fuer die Experimente notwendigen extremen Drehzahlen musste fuer die Zylinderheizung ein Konzept entwickelt werden, das eine beruehrungsfreie und damit drehzahlunabhaengige Leistungseinspeisung erlaubte. Mit vorwiegend optischen Messmethoden wurden die komplexen thermofluiddynamischen Vorgaenge in der Grenzschicht um den rotierenden Zylinder untersucht und vermessen. Die Ergebnisse zeigen u.a., dass die Temperaturdifferenz zwischen Wand und Umgebung von entscheidender Bedeutung fuer die Richtungsumkehr des Waermestromes an der Wand ist und dass ein maximaler Waermeuebergang bereits bei einer Eckert-ZahlEc{approx}0,3 zu erwarten ist. (orig.)

  19. Studies on low-carrier radiofluorination of non-active aromatics with no-carrier-added [{sup 18}F]fluoride; Untersuchungen zur traegerarmen Radiofluorierung nicht-aktiver Aromaten mit n.c.a. [{sup 18}F]Fluorid

    Energy Technology Data Exchange (ETDEWEB)

    Cardinale, Jens

    2013-01-15

    In vivo imaging with positron emission tomography generally demands radiotracers with a high specific activity. In case of fluorine-18 the required no-carrier-added (n.c.a.) starting material is only available in form of fluoride. This and the short half-life of 109.7 minutes of the radionuclide lead to the demand of special methods for radiosyntheses. The only practical procedure for manufacturing n.c.a. [{sup 18}F]fluoro-compounds is therefore nucleophilic substitution. There is, however, still a lack of effective procedures for the labelling of electron rich aromatic molecules starting from n.c.a. [{sup 18}F]fluoride. A process for n.c.a. radiofluorination of these compounds is offered by the reaction of iodonium compounds as starting materials. In this study modern procedures for the synthesis of iodoniumsalts and -ylides were investigated. Several precursor molecules for the versatile synthetic building block 4-[{sup 18}F]fluoroiodobenzene were synthesised. In this course, a new one-pot procedure for the synthesis of iodoniumylides was developed. Further on, the syntheses of suitable iodonium precursors for two fluorophenoxy-derivatives, which are possible antidepressants, were investigated. Due to their binding profile these compounds can be considered as ligands for the serotonin reuptake transporter (SERT) and the norepinephrin reuptake transporter (NET), respectively. The preparation of appropriate iodonium salts proved to be too problematic, while the synthesis of suitable iodoniumylides could be accomplished with satisfactory yields of about 30% and 40 %, respectively. Both compounds were labelled with n.c.a. [{sup 18}F]fluoride and deprotected to the desired target compounds 4-((3-[{sup 18}F]fluorophenoxy)(phenyl)methyl)piperidine and 4-((4-[{sup 18}F]fluorophenoxy)(phenyl)methyl)piperidine in radiochemical yields of about 40 % and 25 %, respectively. Those are now available for preclinical evaluation studies. Furthermore, a process for the palladium catalysed synthesis of {sup 18}F-labelled aromatic molecules was investigated. Initially a suitable reaction protocol was developed for further examination of the dependence of the radiochemical yield on the amount of added carrier. It turned out, however, that the reaction did not proceed without the addition of fluoride-carrier. For the identification of the radioactive products and the determination of the radiochemical yields suitable Chromatographic conditions for the identification of all radioactive products and the determination of their radiochemical yields via HPLC were developed. Furthermore chromatographic conditions for the isolation of the pharmacological relevant n.c.a. [{sup 18}F]fluorophenoxy-derivatives in highest purity were developed.

  20. Pedological investigations regarding thermal, chemical and biological soil cleaning techniques. Final report for the period of investigation 1990 to 1994; Bodenkundliche Untersuchungen zu thermischen, chemischen und biologischen Bodenreinigungsverfahren. Schlussbericht fuer den Bearbeitungszeitraum 1990 bis 1994

    Energy Technology Data Exchange (ETDEWEB)

    Goetz, D; Bauske, B; Claussen, A; Glaeseker, W; Holz, C [Hamburg Univ. (Germany). Inst. fuer Bodenkunde

    1998-12-31

    The hazard potential of contaminated sites is evaluated by means of risk assessments. These can entail diverse measures being taken that may range from the mere observation of the site over protective and restricting measures, different encapsulations to ensure its safety as well as the shifting of contaminated matter, to the decontamination of the site (Council of Experts on Environmental Questions SRU, 1990). Of these measures, soil cleaning demands the greatest effort and should lastingly repair the damage without new damage being caused in another place. (orig.) [Deutsch] Das Gefaehrdungspotential kontaminierter Standorte wird ueber Gefaehrdungsabschaetzungen klassifiziert. Diese Einschaetzung kann zu verschiedenen Massnahmen fuehren. Sie reichen von der reinen Ueberwachung des Standortes ueber Schutz- und Beschraenkungsmassnahmen, Sicherung durch verschiedene Einkapselungen, Umlagerungsmassnahmen bis zur Dekontamination der verunreinigten Materialien (SRU, 1990). Die Bodenreinigung ist dabei die aufwendigste Massnahme und sollte zu einer endgueltigen Beseitigung des Schadens fuehren, ohne dass an anderer Stelle neue Lasten entstehen. (orig.)

  1. Effects of airplane emissions on the composition of the atmosphere: Investigations using a mesoscale chemical transport model; Der Einfluss von Flugzeugabgasen auf die Zusammensetzung der Atmosphaere: Untersuchungen mit einem mesoskaligen Chemie-Transport-Modell

    Energy Technology Data Exchange (ETDEWEB)

    Lippert, E.

    1996-12-31

    In the present work the impact of aircraft emissions on the atmospheric composition is studied using a mesoscale chemistry transport model. To simulate the impact of aircraft exhausts several modifications on the EURAD model system have been performed. The upper boundary of the model has been extended from 100 hPa up to 10 hPa. The vertical resolution of the model has been refined especially in tropopause altitudes extending the number of model layers from 15 to 29. Additionally the initialization and the treatment of the boundary conditions has been improved by coupling the trace gas concentration fields with the individual meteorological situation. To guarantee an adequate representation of the atmospheric chemistry the chemical mechanism CHEST has been developed and implemented into the chemistry transport model. CHEST treats the most important chemical processes of the troposphere and lower stratosphere. In the frame of the present work sensitivity studies with a box model and with the threedimensional chemistry transport model have been performed to investigate the impact of aircraft emissions upon the atmosphere. (KW) [Deutsch] In der vorliegenden Arbeit werden die Auswirkungen der Flugzeugemissionen auf die Zusammensetzung der Atmosphaere mit Hilfe eines mesoskaligen Chemie-Transport-Modells untersucht. Zur Simulation der Ausbreitung der Flugzeugabgase wurden am EURAD-Modell-System umfangreiche Veraenderungen vorgenommen. Der obere Modellrand des Chemie-Transport-Modells ist von 100 hPa auf 10 hPa erhoeht worden. Die vertikale Aufloesung des Modells wurde insbesondere im Tropopausenbereich durch eine Erhoehung der Gesamtzahl der Modellschichten von 15 auf 29 wesentlich verfeinert. Ausserdem ist die Initialisierung der Spurenstoffverteilung im Modell an die Dynamik gekoppelt worden. Dem Chemie-Transport-Modell stehen damit an die jeweilige meteorologische Situation angepasste Konzentrationsfelder zur Initialisierung und zur Behandlung der Fluesse durch den Modellrand bereit. Zur repraesentativen Behandlung der atmosphaerischen Chemie wurde der Chemiemechanismus CHEST entwickelt und in das Chemie-Transport-Modell implementiert. CHEST beruecksichtigt die bedeutendsten chemischen Prozesse der Troposphaere und der unteren Stratosphaere. (KW)

  2. The flexfuel tractor. Invesigations on the combustion behaviour of vegetable oil fuels and on the discernability of fossil and biogenic fuels; Der Flexfuel Traktor. Untersuchungen zum Verbrennungsverhalten von Pflanzenoelkraftstoffen und zur Unterscheidbarkeit fossiler und biogener Kraftstoffe

    Energy Technology Data Exchange (ETDEWEB)

    Dieringer, Stefanie

    2012-07-01

    Increasing energy prices, especially for fossil fuels, as well as the necessity to reduce CO{sub 2} emissions are emphasizing the advantages of self-produced vegetable oil fuels in agriculture. Monetary advantages are depending on basic conditions like farm size or tax legislation, which can be changing locally as well as temporarily. Due to the differing properties of diesel and vegetable oil fuel, engines have to be adapted to each fuel to fulfil performance requirements as well as emission limits and reliability. Knowing that there are advantages of vegetable oil compared to diesel fuel, though not always and everywhere present, it becomes obvious that the well known flexible fuel concept of passenger cars should be adapted for diesel engines of agricultural machines. So called flexfuel engines imply the detection of the fuel type and an automated adjustment of the engine control parameters without any manual action of an operator. Therefore, the first step consists of the evaluation of the combustion properties of rapeseed, sunflower, jatropha and false flax oil compared to diesel fuel. The tested vegetable oils showed very similar behaviour in the tested common rail diesel engine. Especially the limited emissions were met with the same engine control software with all vegetable oils. In consequence it is possible to realize a flexfuel engine using the two engine control maps available at the moment, one for diesel and the other one for vegetable oil fuels. For further investigations one oil type, namely rapeseed oil was selected to test the combustion behaviour of fuel blends made of diesel and vegetable oil. The goal was to determine the blend ratio of vegetable oil and diesel fuel at which the engine control software has to be changed from the diesel to the vegetable oil map automatically. If the fuel consists of 40% or more vegetable oil, the vegetable oil engine control map has to be selected in order to fulfil legal emission limits. Finally the feasibility to detect different fuel types, especially vegetable oils and diesel, but also blends of those fuels and additionally biodiesel, was evaluated. A fluid property sensor was utilized to measure the viscosity, the permittivity constant, the density and the temperature of different fuels and blends. At a fuel temperature of 40 C diesel, vegetable oil and biodiesel can be detected using only two of the sensor's three values. The accuracy of the sensor decreases with increasing viscosity of the fluid, thus two or all three measured values have to be used to determine the fuel type reliably. This is even more important, if not only straight fuels, but also unknown blends of different fuel types need to be detected, which is very likely in the daily use of a flexfuel vehicle. Having determined the reliability of this fluid property sensor in a temperature range of 25 to 60 C, an accuracy of 10 to 20% can be observed, which leads to a total detection accuracy of about 10 to 20% fuel blend differences. This is sufficient for engine operation with the two engine maps strategy. It was verified that a current stage 3A common rail for valve technology engine can be transferred into a flexfuel engine using only two engine control maps and selecting those based on a sensor based fuel detection. Once the interpolation between those engine control maps is enabled, the results of the combustion analysis of diesel-vegetable oil fuel blends can be utilized again. (orig.)

  3. Studies on the effectiveness of measures to maintain the integrity of pressurized components in German nuclear power plants. Final report; Untersuchungen zur Wirksamkeit von Massnahmen zur Sicherstellung der Integritaet druckfuehrender Komponenten in deutschen Kernkraftwerken. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Elmas, M.; Jendrich, U.; Michel, F.; Reck, H.; Schimpfke, T.; Walter, M.; Wenke, R.

    2013-03-15

    The overall objective of the project was to investigate the effectiveness of measures to maintain the as-built quality of the pressure-retaining components in German nuclear power plants. In particular, investigations were performed on the application of the break preclusion concept, existing monitoring systems and the significance of the pressure test as part of the inspection concept. Moreover, the KompInt knowledge base has been updated. Break preclusion for pipes was applied in all German plants already during planning or after commissioning to a varying extent. The basic features of the required assessments were considered in the German nuclear regulations for the first time by inclusion in the safety requirements for nuclear power plants of 2012. The requirements for assessments, differing in their degree of detail, in the interpretations of these safety requirements and in the safety standard KTA 3206 are still in the draft stage. For the first time, the vessels as well as housings of valves and pumps are also included in the concept. Through the use of advanced monitoring systems it was possible in German plants at an early stage to establish modes of operation that minimise the load on components, to carry out appropriate technical backfitting measures, and to identify damages. In plant areas where local water chemistry parameters may result that deviate from the specification, the effectiveness of water chemistry monitoring is limited. In this case, other operational measures must be taken. The results of the simulations performed with the help of the GRS-developed PROST computer code to determine the significance of pressure tests lead - in accordance with the results of operating experience evaluation - to the conclusion that pressure tests carried out within the pressure-retaining boundary contribute to safeguarding the integrity. The user-friendliness of the KompInt knowledge base has been increased by changing over to a new hardware, a software update and improvement of the user guidance. Its necessary update was performed based on a systematic inventory. By adding new data, documents and references, the contents of the individual modules have been extended.

  4. Power to gas. Investigation of energy storage options in the frame of the DVGW-innovation initiative; Power to Gas. Untersuchungen im Rahmen der DVGW-Innovationsoffensive zur Energiespeicherung

    Energy Technology Data Exchange (ETDEWEB)

    Mueller-Syring, Gert; Henel, Marco [DBI-GUT, Freiberg (Germany); Rasmusson, Hans [Deutsche Vereinigung des Gas- und Wasserfaches e.V. (DVGW), Bonn (Germany); Mlaker, Herwig [E.on Ruhrgas AG, Koeln (Germany); Koeppel, Wolfgang [European Bioinformatics Institute (EBI) (United Kingdom); Hoecher, Thomas [Verbundnetz Gas AG (VNG), Leipzig (Germany); Sterner, Michael; Trost, Tobias [Fraunhofer Institut fuer Windenergie und Energiesystemtechnik (IWES), Kassel (Germany)

    2011-07-01

    The existing natural gas grid is an efficient, safe, environmental friendly and accepted energy infrastructure. This infrastructure is able to convey hydrogen and renewable methane beyond its initial purpose to transport natural gas. Using this existing infrastructure to accommodate renewable gases will support the further development of renewable energies and their integration in the energy systems. Thus the natural gas grid can be a partner of renewable energies. (orig.)

  5. Energy and substance conversion in biogas plants. Results of measurement investigations of agricultural biogas plants in the Rheinland; Energie- und Stoffumsetzung in Biogasanlagen. Ergebnisse messtechnischer Untersuchungen an landwirtschaftlichen Biogasanlagen im Rheinland

    Energy Technology Data Exchange (ETDEWEB)

    Besgen, S.

    2005-08-15

    The current data situation on biogas technology is not extensive and is mainly based on laboratory testing. This was the starting point for a pilot project and the dissertation at hand, where data was collected from four agricultural biogas plants during a period of two years. These four plants are equipped with extensive measurement technology and are run under mesophilic temperature conditions. They utilize manure, renewable primary products and organic waste products. The measurements carried out cover balancing, i.e. determining the gas-output, production and usage of energy, as well as process analysis. The latter investigates parameters which permit statements on stability of the fermentation process and on the substances of contents of the substrate. Input and output of the plants were quantified during the measurement periods. Input is defined as organic substance, output as the production of electricity and heat from burning biogas in block-type thermal power stations. Concerning the latter, the thermal and electrical efficiency factor was calculated, indicating also the respective fuel oil proportion. Furthermore, the process energy demand in form of electricity and heat for running the plants was analysed. It was possible to define the quality of the biogas produced as well as the quantity of individual substrates based on standard gas calculations. The measurement programme gained valuable data for the practical use of biogas plants. The results will be helpful for planning and designing these plants. (orig.)

  6. Analytische Geometrie

    Science.gov (United States)

    Kemnitz, Arnfried

    Der Grundgedanke der Analytischen Geometrie besteht darin, dass geometrische Untersuchungen mit rechnerischen Mitteln geführt werden. Geometrische Objekte werden dabei durch Gleichungen beschrieben und mit algebraischen Methoden untersucht.

  7. Geschlechterstereotype im Einsatz

    Directory of Open Access Journals (Sweden)

    Erika Kegyes

    2007-11-01

    Full Text Available Die umfangreiche Monographie gehört zum Forschungsbereich der kritischen angewandten Linguistik (Critical Applied Linguistics und liegt sowohl theoretisch als auch praktisch im Schnittpunkt der gender- und werbesprachlichen Untersuchungen.

  8. Genetiese parameters van speenkafrf^ eienskappe by ...

    African Journals Online (AJOL)

    Genetiese en. Omgewingsparameters van 'n VIeisraskudde. Ph.D.-tesis,. Univ. van die Oranje-Vrystaat. VAN MARLE, J., 1964. Untersuchungen tiber Einfltisse von. Umwelt und Erbanlage auf die Gewichtsentwicklung von. Fleischrinden unter extensiven Weidebedingungen der. Versuchstation Armoedsvlakte in Stidafrika.

  9. Einige Beobachtungen an Anemonenfischen in der Karibischen See

    NARCIS (Netherlands)

    Albrecht, H.

    1977-01-01

    Unter Anemonenfischen verstehen wir hauptsächlich Arten der indopazifischen Gattung Amphiprion (Riffbarsche, Pomacentridae), die in Seeanemonen leben. Mariscal (1966) und neuerdings Allen (1975) haben die vielen Untersuchungen dieser Beziehung zusammengefasst. Aus der Literatur sind andere

  10. Actinides

    International Nuclear Information System (INIS)

    Martinot, L.; Fuger, J.

    1985-01-01

    The oxidation behavior of the actinides is explained on the basis of their electronic structure. The actinide elements, actinium, thorium, protactinium, uranium, neptunium, plutonium, americium, curium, berkelium, californium, einsteinium, fermium, mendelevium, nobelium, and laurencium are included. For all except the last three elements, the points of discussion are oxidation states, Gibbs energies and potentials, and potential diagram for the element in acid solution; and thermodynamic properties of these same elements are tabulated. References are cited following discussion of each element with a total of 97 references being cited. 13 tables

  11. Cold fusion reactions with 48Ca

    International Nuclear Information System (INIS)

    Gaeggeler, H.W.; Jost, D.T.; Tuerler, A.

    1989-04-01

    Cold fusion reactions with 48 Ca on the targets 208 Pb, 209 Bi, 197 Au, 184 W, 180 Hf are reported. The experiments were performed at the velocity filter SHIP of GSI. The maximum cross sections show a steep descent by about four orders of magnitude when going from 224 Th to 228 U as compound nuclei. Between uranium and einsteinium the cross sections stay rather low and increase by about two orders of magnitude for nobelium. For lawrencium the cross section decrease again. 7 figs., 1 tab., 38 refs

  12. High-accuracy coupled cluster calculations of atomic properties

    Energy Technology Data Exchange (ETDEWEB)

    Borschevsky, A. [School of Chemistry, Tel Aviv University, 69978 Tel Aviv, Israel and Centre for Theoretical Chemistry and Physics, The New Zealand Institute for Advanced Study, Massey University Auckland, Private Bag 102904, 0745 Auckland (New Zealand); Yakobi, H.; Eliav, E.; Kaldor, U. [School of Chemistry, Tel Aviv University, 69978 Tel Aviv (Israel)

    2015-01-22

    The four-component Fock-space coupled cluster and intermediate Hamiltonian methods are implemented to evaluate atomic properties. The latter include the spectra of nobelium and lawrencium (elements 102 and 103) in the range 20000-30000 cm{sup −1}, the polarizabilities of elements 112-114 and 118, required for estimating their adsorption enthalpies on surfaces used to separate them in accelerators, and the nuclear quadrupole moments of some heavy atoms. The calculations on superheavy elements are supported by the very good agreement with experiment obtained for the lighter homologues.

  13. High-accuracy coupled cluster calculations of atomic properties

    International Nuclear Information System (INIS)

    Borschevsky, A.; Yakobi, H.; Eliav, E.; Kaldor, U.

    2015-01-01

    The four-component Fock-space coupled cluster and intermediate Hamiltonian methods are implemented to evaluate atomic properties. The latter include the spectra of nobelium and lawrencium (elements 102 and 103) in the range 20000-30000 cm −1 , the polarizabilities of elements 112-114 and 118, required for estimating their adsorption enthalpies on surfaces used to separate them in accelerators, and the nuclear quadrupole moments of some heavy atoms. The calculations on superheavy elements are supported by the very good agreement with experiment obtained for the lighter homologues

  14. Investigations on gene-ecological effects due to simultaneously applicated environmental pollutants via shoot and root system in the forest tree species Norway spruce. Final report. Untersuchungen ueber genetisch-oekologische Auswirkungen simultaner Immissionsbelastungen des Spross- und Wurzelsystems der Baumart Fichte. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Scholz, F.; Geburek, T.

    1988-10-01

    Under controlled conditions detrimental substances were applied via the shoots and roots to study the induced selective effects in the forest tree species Picea abies. Clones, single trees progenies, and provenances were employed. As toxic substances aluminium (Al) and sulphur dioxide (SO{sub 2}) were applied using hydroponics and fumigation chambers. Genetic variation was remarkable. A combined application of the substances caused a higher growth depression and induced a higher damage of the needles compared to the effects of the single stress factors. Sensitive subsets had lower genetic variation compared to the respective plants which were more tolerant. Already results of field trials indicated that high genetic variation is useful for the stability of forest tree populations. The evidents of the present study confirm this hypothesis. (orig.) With 46 refs., 13 tabs., 19 figs.

  15. Examinations for quantifying the difference in radiation doses at the least favorable locations between facility sites in highly structured topographies (valleys) and in plane terrain (licensing procedures); Untersuchungen zur Quantifizierung des Unterschieds in der Dosisbelastung am unguenstigsten Aufpunkt zwischen Standorten in topographisch stark strukturiertem Gelaende (Tal-Lagen) und in ebenem Terrain (Genehmigungsverfahren)

    Energy Technology Data Exchange (ETDEWEB)

    Raskob, W. [Dr. Trippe Ingenieurgesellschaft mbH, Karlsruhe (Germany)

    1995-08-01

    The MCF wind field model and the LASAT Lagrange particle model served to study topography effects on the spreading of radionuclides. Concentrations in bottom layers of the atmosphere at maximum-dose positions in hilly country topography are up to a factor 6 higher than in plain country. For concentrations in the soil the results have a similar relation. (orig.)

  16. Magnetism and metal insulator transition in FeSi and FeGe. Ab Initio investigations of the electronic structure; Magnetismus und Metall-Isolator-Uebergang in FeSi und FeGe. Ab-initio-Untersuchungen der elektronischen Struktur

    Energy Technology Data Exchange (ETDEWEB)

    Neef, Matthias

    2007-03-19

    Aim of this thesis was to reach by a systematic study of different ab initio procedures an improved description of the electronic properties of FeSi and FeGe. Central result is the itinerant description of FeSi as a semiconductor in the neighbourhood of a ferromagnetic instability. The regardment of the nonlocal exchange in the effective one-particle approximation leads to a metastable magnetic state scarcely above the magnetic ground state. The application of the hybrid functional leads to a 1st order metal-isolator transition for large lattice parameters: FeSi transforms at increasement of the lattice parameter from an unmagnetic isolator to a magnetic metal. A similar behavior is found in the isostructural compound FeGe. The two systems FeSi and FeGe were systematically and detailedly analyzed by means of ab initio procedures. Thereby the structural, electronic, and magnetic properties were studied with DFT and HF calculations. Both calculations with spin polarization and without spin polarization were performed.

  17. Study on the regional and global rise in NO{sub x} and non-methane hydrocarbon concentrations in the upper troposphere and lower stratosphere as a consequence of airplane emissions. Final report; Untersuchungen zur regionalen und globalen Erhoehung der NO{sub x}- und Nichtmethankohlenwasserstoff-Konzentrationen in der oberen Troposphaere und der unteren Stratosphaere infolge Flugzeugemissionen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Rohrer, F

    1996-01-05

    In this project a chemical mechanism was developed for the upper troposphere which permits examining the photochemical formation of ozone. Using this mechanism it was found that at medium latitudes (at 10 km altitude in June) hydroxyl radical concentration and the rate of photochemical ozone formation to which it is coupled depend on NO{sub x} concentrations in a strongly non-linear manner, peaking at 110 ppt NO{sub x} and 200 pp NO{sub x}, respectively. Regarding the assessment of the effects of air traffic it was thus shown that in attempting to forecast changes in ozone concentration one must not only take aviation-related changes in NO{sub x} concentrations into account but also the forecasted absolute concentrations of NO{sub x}. The measured data were interpreted by combining a simplified model of NO{sub x} reactions with an existing three-dimensional transport model and comparing the measured and the calculated vertical NO profiles. It can be said that the 3D chemical transport model supplies realistic tropospheric NO{sub x} ratios at least for medium latitudes (49 to 56 N) in the months of May, June, July, December, and January. At these latitudes the tropospheric NO{sub x} budget is mainly governed by anthropogenic emissions. (orig./KW) [Deutsch] In diesem Projekt wurde ein Chemiemechanismus fuer die obere Troposphaere entwickelt, der es erlaubt, die photochemische Ozonbildung zu untersuchen. Mit diesem Mechanismus konnte fuer mittlere noerdliche Breiten (fuer 10 km Hoehe, Juni) gezeigt werden, dass die Hydroxylradikalkonzentration und die damit gekoppelte photochemische Ozonbildungsrate in stark nichtlinearer Weise von der Stickoxidkonzentration abhaengen und bei etwa 110 ppt NO{sub x} (bezw. 200 ppt NO{sub x} fuer die Ozonbildungsrate) ein Maximum durchlaufen. Fuer die Beurteilung der Auswirkungen des Flugverkehrs konnte deswegen gezeigt werden, dass die Voraussagen ueber Ozonveraenderungen nicht nur von der Aenderung der Stickoxidkonzentration durch den Flugverkehr abhaengen, sondern auch von den vorhergesagten Absolutkonzentrationen der Stickoxide. Fuer die Interpretation der Messdaten wurde ein vorhandenes 3 dimensionales Transportmodell mit einer einfachen Chemie der Stickoxide versehen und die gemessenen Vertikalprofile von NO mit berechneten verglichen. Es kann gesagt werden, dass das 3D-chemische Transportmodell realistische Stickoxidmischungsverhaeltnisse in der Troposphaere in mittleren Breiten (49 N bis 56 N) in den Monaten Mai, Juni und Juli sowie November, Dezember und Januar liefert. In diesen Breiten wird das troposphaerische Budget der Stickoxide hauptsaechlich durch anthropogene Emissionen bestimmt. (orig./KW)

  18. Investigation of radiological consequences of a serious accident in Swiss nuclear power plants on the drinking water supply and preventive measures in waterworks for securing drinking water quality and supply; Untersuchungen zu radiologischen Folgen schwerer Unfaelle in schweizerischen Kernkraftwerken auf die Trinkwasserversorgung und vorbeugende Massnahmen im Wasserwerk zur Absicherung der Trinkwasserqualitaet und -versorgung

    Energy Technology Data Exchange (ETDEWEB)

    Ustohalova, V.; Kueppers, C.; Claus, M. [Oeko-Institut e.V., Darmstadt (Germany)

    2016-07-01

    The radiological consequences of a serious accident in Swiss nuclear power plants on the drinking water supply was studied, preventive measures for securing the drinking water quality were elaborated. Based on the scaling of thermal power and burnup of the used nuclear fuel the fission product release in case of a severe accident was estimated for airborne and waterborne migration paths. In cities that use the rivers for their water drinking water supplies have to stop the water abstraction. The Swiss tolerance and limiting values for radionuclides in drinking water would be exceeded shortly after the accident and the hazardous situation would last for more than 90 days.

  19. Study on the uptake and distribution of gadolinium based contrast agents in biological samples using laser ablation with inductively coupled plasma mass spectroscopy; Untersuchungen zur Aufnahme und Verteilung von gadoliniumbasierten Kontrastmitteln in biologischen Proben mittels Laserablation mit induktiv gekoppelter Plasma-Massenspektrometrie

    Energy Technology Data Exchange (ETDEWEB)

    Lingott, Jana

    2016-01-05

    Gadolinium based contrast agents are used for magnetic resonance imaging. After their excretion by medicated patients they reach surface water passing waste water treatment plants where they are not removed sufficiently. The behavior of the contrast agents in the environment and the interaction with organisms was investigated in this work due to the toxicity of the free Gd{sup 3+} ion and the associated risks, such as accumulation in the human food chain. In this work, the two elemental analytical imaging methods laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and synchrotron radiation X-ray fluorescence analysis (SRXRF) have been used to investigate the uptake, distribution, and excretion of Gd-based contrast agents by various biological systems. Both methods were analytically characterized and compared for this application. The detection limits of gadolinium were determined under optimized conditions by LA-ICP-MS and SRXRF. With calibration by remains of dried elemental standard droplets detection limits of 0.78 pg absolute amount of gadolinium (LA-ICP-MS), respectively 89 pg (SRXRF) were reached. Based on filamentous algae as water plants the uptake and the excretion of Gd-based contrast agents were revealed. The dependence on concentration of the contrast agent in the exposition solution and the independence of temporal uptake within one to seven days were studied for duckweed. By LA-ICP-MS gadolinium was quantified in a leaf of cress plant. The verification of the results was performed by SRXRF and ICP-MS after digestion. Furthermore, the uptake and distribution of Gd-based contrast agents in higher organisms (water flea) were observed. The exact location of gadolinium was resolved by three-dimensional μ-computed tomography by the comparison of an exposed with a Gd-free water flea. In all studies, gadolinium was detected in the investigated exposed model organisms. It can be concluded that the contrast agents were taken from the environment.

  20. Investigations on the inactivation of selected bacteria and viruses during mesophilic and thermophilic anaerobic alkaline cofermentation of biological waste materials, food residues and other animal residues; Seuchenhygienische Untersuchungen zur Inaktivierung ausgewaehlter Bakterien und Viren bei der mesophilen und thermophilen anaeroben alkalischen Faulung von Bio- und Kuechenabfaellen sowie anderen Rest- und Abfallstoffen tierischer Herkunft

    Energy Technology Data Exchange (ETDEWEB)

    Hoferer, M. [Hohenheim Univ., Stuttgart (Germany). Inst. fuer Umwelt- und Tierhygiene sowie Tiermedizin mit Tierklinik

    2001-07-01

    The purpose of this study is to investigate the inactivation kinetics of a number of different bacteria (Salmonella Senftenberg, Escherichia coli O157, Enterococcus faecium) and viruses (Bovine Enterovirus (ECBO), Equine Rhinovirus (ERV), Poliovirus, Bovine Parvovirus (BPV)) during the process of anaerobic cofermentation. Experiments were conducted in a semi-technical biogas plant at the University of Hohenheim. The fermenter was fed with a mixture of slurry from pigs or cattle (75%) and leftovers (25%) and was run under mesophilic (30 C + 35 C) as well as under thermophilic temperature conditions (50 C + 55 C). Volume and filter-sandwich germ-carriers were specifically developed and/or optimised for these analyses. Parallel to the experiments at the University of Hohenheim and under almost identical process conditions, various viruses (African Swine Fever Virus, Pseudorabies Virus, Classical Swine Fever Virus, Foot and Mouth Disease Virus, Swine Vesicular Disease Virus) were examined at the Federal Research Centre for Virus Diseases of Animals in Tuebingen. The results obtained at each research institution are directly compared. (orig.)

  1. Experiments on the VERONA test facility on formation and decomposition of polyhalogenated dioxins and furans and other organic halogen compounds in the combustion process; Untersuchungen an der Technikumsanlage VERONA zur Bildung und zum Abbau von polyhalogenierten Dioxinen und Furanen und anderen Organohalogenverbindungen in Verbrennungsprozessen

    Energy Technology Data Exchange (ETDEWEB)

    Schueler, D.

    2002-09-01

    The study examines measures to reduce dioxin formation in thermal waste treatment. The VERONA pilot plant (VErbrennungsanlage mit feststehendem ROst und getrennter NAchbrennkammer - incineration plant with stationary grate and separate post-combustion chamber) was developed to carry out practical experiments. The experiments were conducted using wood and propane as basic combustible materials and with controlled dosage of various bromine-, chlorine- and copper-containing compounds. The behaviour of the following compounds was studied in the combustion chamber, after the post-combustion chamber and after the heat exchanger: PCPh, PBrPh, PCBz, PBrBz, PCDD/F and PBDD/F. Experiments involving the variation of various primary measures (moisture content of combustible material, air supply, temperature in the combustion chamber, quality of post-combustion, quantities and structures of halogen compounds) have shown that the quality of post-combustion plays a much greater role than the other measures. For this reason, a search was launched for indicators which can be measured readily and by means of which the quality of post-combustion in terms of organohalide decomposition can be evaluated, and which correlate closely with the dioxin concentrations after the heat exchanger. It became apparent that the congeners of the chlorophenols and of the chlorobenzenes, measured in various incineration stages, are not suited, nor is the CO content. (orig.)

  2. Comparison of magnetic resonance imaging signs and clinical findings in follow-up examinations in children and juveniles with temporomandibular joint involvement in juvenile idiopathic arthritis; Vergleich magnetresonanztomografischer und klinischer Befunde von Follow-up-Untersuchungen bei Kindern und Jugendlichen mit rheumatischer Temporomandibulararthritis

    Energy Technology Data Exchange (ETDEWEB)

    Mussler, A.; Schroeder, R.J. [Charite Berlin (Germany). Radiologie; Allozy, B. [Martin-Gropius-Krankenhaus, Eberswalde (Germany). Klinik fuer Kinder- und Jugendpsychiatrie; Landau, H. [Charite Berlin (Germany). Inst. fuer Kieferorthopaedie, Orthodontie und Kinderzahnmedizin; Kallinich, T. [Charite Berlin (Germany). Centrum fuer Frauen-, Kinder- und Jugendmedizin; Trauzeddel, R. [HELIOS Klinikum Berlin-Buch (Germany). Klinik fuer Kinder- und Jugendmedizin

    2010-01-15

    The aim of this study was to analyze the extent to which pathological findings of temporomandibular joint (TMJ) in magnetic resonance imaging (MRI) follow-up examinations are correlated with clinical symptoms in patients with TMJ involvement in juvenile ideopathic arthritis (JIA) over time. Data from 34 patients with TMJ involvement in JIA was retrospectively examined. Shortly after two clinical examinations, the first MRI and the follow-up MRI were performed. The MRI examinations took place with 1.5 T MRI. In both MRI examinations alterations on the condyle (MRI1: 88 %, MRT2: 91 %) and contrast enhancement (MRT1: 76 %, MRT2 65 %) were found most frequently. TMJ pain (65 %) and lower mouth opening capacity (65 %) were the number one finding in the first clinical examination. A statistically significant correlation was found between the alterations on the condyle and TMJ pain (p = 0.025) and between the alterations on the condyle and lower mouth opening capacity (p = 0.019). By comparing the results of the first MRI with the results of the follow-up MRI, we identified a trend towards a progression of TMJ arthritis, while the clinical follow-up showed an improvement in most patients. We found a discrepancy between the progressive or stable trends of pathological findings in follow-up MRI and the decrease in clinical symptoms over time. Therefore, follow-up examination by MRI shows important information for correct evaluation about the stage of TMJ arthritis and about the need for treatment. Consequently, follow-up examination by MRI is an appropriate addition to clinical examination in the therapeutic concept. (orig.)

  3. Microbial remediation of soil pollution from ore mining. Part 3: Cyanide removal and biosorption of heavy metals in mining and processing water; Untersuchungen zur mikrobiellen Sicherung von Erzbergbaualtlasten. Teilvorhaben 3: Cyanidabbau und Biosorption von Schwermetallen in Abwaessern aus Erzbergbau- und Aufbereitungsbetrieben. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Blumenroth, P.; Bosecker, K.

    1999-12-01

    1. Cyanide degradation: Of the cyanide- and thiocyanate-degrading bacteria, Burkholderia cepacia and Pseudomonas spec. were the most effective. 2. Biosorption: Of the isolates suited for biosorption of heavy metals, 597-A (non-identifiable) and 597-A2 (Aspergillus fumigatis) had the biggest potential. The sorption capacity of the fungi for metals varied with the C source used for their growth: apple juice > molasses > glucose. The fungi are not cyanide-sensitive and can even degrade cyanide. Living biomass had better metal sorption efficiencies than dead mycelium. The biosorption rates in waste water were usually higher than in broth. Depending on the metal composition and concentrations and on the exposure time and volume of the mycelia, up to 85 % of the initial concentration was removed from the liquid phase. The capacity of different biomasses for the sorption of metal mixtures was between 65 and 80 mg/g of dry matter depending on the experimental conditions, with peak rates up to 100 mg/g. [German] 1. Cyanidabbau: Von den zum Abbau von Cyaniden und Thiocyanat befaehigten Bakterien erwiesen sich Burkholderia cepacia und Pseudomonas spec. als am besten geeignet. 2. Biosorption: Von den zur Biosorption von Schwermetallen befaehigten Isolaten wiesen 597-A1 (nicht identifizierbar) und 597-A2 (Aspergillus fumigatus) das groesste Potential auf. Die Sorptionsleistung der Pilze fuer Metalle war abhaengig von der C-Quelle, die zur Anzucht verwendet wurde: Apfelsaft>Melasse>Glucose. Die Pilze sind unempfindlich gegenueber Cyanid und sogar zu dessen Abbau in der Lage. Lebende Biomasse sorbierte mehr Metalle als abgetoetetes Pilzmyzel. Die in Abwaessern ermittelten Biosorptionsraten waren meist hoeher als die in Medium erzielten Raten. Je nach Zusammensetzung und Konzentration der Metalle sowie Einwirkdauer und Menge des eingesetzten Pilzmyzels wurden bis zu 85% des Ausgangsgehaltes aus der Fluessigphase entfernt. Die Kapazitaet verschiedener Biomassen fuer die Sorption von Metallgemischen lag je nach Versuchsansatz bei bis zu 100 mg Metall/g Trockengewicht, meist jedoch zwischen 65-80 mg/g TG. (orig.)

  4. Material science studies on the formation and growth of pores in the production and creep of single-crystal nickel-based superalloys; Werkstoffwissenschaftliche Untersuchungen zur Bildung und zum Wachstum von Poren bei der Herstellung und beim Kriechen einkristalliner Nickelbasis-Superlegierungen

    Energy Technology Data Exchange (ETDEWEB)

    Buck, Heinrich Joergen

    2015-02-20

    Single crystal Ni-base superalloys (SX) are used for blades in fossil fuel fired power plants and aero engines. Here they have to withstand high mechanical stresses at temperatures close to their melting point. The blades are manufactured by a Bridgman type of directional solidification, followed by a multiple step heat treatment. During the dendritic solidification, pores can form due to undissolved gas, macroshrinkage by inadequate gating and microshrinkage caused by poor feeding between dendrites. Additional pores can form in the interdendritic regions during the multiple step heat treatment which follows solidification. It is believed, that these pores form on the basis of a Kirkendall effect which accounts for the fast diffusion of Al atoms away from microstructural regions with non-equilibrium γ/γ' eutectic. During creep, pores can grow and change their shapes. It has been shown, that during creep in the high temperature / low stress regime new pores form, which are smaller than those pores that can be found in the undeformed material. In the present work, the evolution of porosity in the single crystal Ni-base superalloy ERBO/1 during processing and creep is investigated. Quantitative microstructural analyses were performed on metallographic cross sections. Sampling fields of 4500 x 1000 μm{sup 2} were investigated by using a combination of scanning electron microscopy with quantitative image analysis. Interrupted creep tests with a miniature tensile creep specimen were performed with load direction parallel to left angle 100 right angle and left angle 110 right angle direction, respectively. Pore parameters (area, perimeter, Feret's diameter) for individual pores were obtained and two form factors were introduced. The evolution of the compiled statistical distributions of pore parameters and shape factors are discussed. The results are compared to recent findings by Link et al., 2006 and Maelzer et al., 2007. In the present study it was shown that the quantitative metallographic approach is able to qualitatively reproduce all important details of porosity evolution, which were identified by Link et al. using synchrotron radiation. Pores which the metallographic method detects directly after casting appear in a low density (17 pores/mm{sup 2}) and show very broad log-normal size distributions. Solidification pore sizes (in terms of pore areas on the metallographic cross section) can vary from 2 to 200 μm{sup 2}. During the multiple step homogenization heat treatment of ERBO/1, new pores form and the pore density increases to 34 pores/mm{sup 2}. Simultaneously, one can detect an increase in average pore sizes. The size distribution of pores shifts to higher values. During high temperature and low stress creep, new small pores form (pore density increases to values ranging from 139 pores/mm{sup 2} to 193 pores/mm{sup 2}) and the size distributions evolve from unimodal (as-cast and heat treated material state, prior to creep) to bimodal (early stages of creep). The present study furthermore represents the missing link between the synchrotron studies of Link et al., 2006 regarding the evolution of porosity and the metallographic investigations of Maelzer et al., 2007, who investigated the role of pores with respect to creep rupture. The advantage of the present study is that both, the investigation of porosity evolution and the investigation on the role of pores on creep rupture, were performed with one alloy at the same temperature/stress conditions. It has been shown, that the distribution of pores in the material and the alignment of pores relative to the loading direction are important. Maelzer et al. showed, that creep specimens with pores aligned parallel to the loading direction ([001] specimens) showed higher rupture strains compared to specimens, where pores were aligned perpendicular to the loading direction ([110] specimens). These findings have been confirmed by the present study. The metallographic results, presented in this work, suggest that creep rupture is associated with the formation of microcracks at larger solidification and heat treatment pores, which can grow, interlink and initiate final creep rupture. Creep pores appear, due to their size, to be less important with respect to creep rupture. The alignment of pores along the dendrites and their relative position to the loading direction are the key factors, that can limit creep life. Finally, the influence of the crystallographic orientation on the evolution of porosity was investigated. It has been shown, that there are no fundamental differences of the size and shape factor distributions, when [001] and [110] oriented specimens are compared, but there are differences in the appearance of crystallographic facets and an orientation dependency of pore growth is suggested.

  5. Quantification of volatile organic compounds in exhaled human breath. Acetonitrile as biomarker for passive smoking. Model for isoprene in human breath; Quantifizierung organischer Spurenkomponenten in der menschlichen Atemluft. Acetonitril als Biomarker fuer Passivrauchen. Modell fuer Isopren im Atem, Zusammenhang Isoprenkonzentration, Cholesterinsynthese, lebensmittelchemische Untersuchungen an Knoblauch und Zwiebel

    Energy Technology Data Exchange (ETDEWEB)

    Prazeller, P

    2000-03-01

    The topic of this thesis is the quantification of volatile organic compounds in human breath under various circumstances. The composition of exhaled breath reflects metabolic processes in the human body. Breath analysis is a non invasive technique which makes it most interesting especially for medical or toxicological applications. Measurements were done with Proton-Transfer-Reaction Mass-Spectrometry (PTR-MS). This technique combines the advantage of small fragmentation of chemical ionization with highly time resolved mass spectrometry. A big part of this work is about investigations of exposition due to tobacco smoke. After smoking cigarettes the initial increase and time dependence of some compounds in the human breath are monitored . The calculated decrease resulting only from breathing out the compounds is presented and compared to the measured decline in the breath. This allows the distinction whether breathing is the dominant loss of a compound or a different metabolic process remover it more efficiently. Acetonitrile measured in human breath is presented as a biomarker for exposition to tobacco smoke. Especially its use for quantification of passive smoking, the exposition to environmental tobacco smoke (ETS) is shown. The reached accuracy and the fast way of measuring of acetonitrile in human breath using PTR-MS offer a good alternative to common used biomarkers. Numerous publications have described measurements of breath isoprene in humans, and there has been a hope that breath isoprene analyses could be a non-invasive diagnostic tool to assess serum cholesterol levels or cholesterol synthesis rate. However, significant analytical problems in breath isoprene analysis and variability in isoprene levels with age, exercise, diet, etc. have limited the usefulness of these measurements. Here, we have applied proton-transfer-reaction mass spectrometry (PTR-MS) to this problem, allowing on-line detection of breath isoprene. We show that breath isoprene concentration increases within a few seconds after starting exercise or awakening during the night as a result of a rapid increase in heart rate, and then reaches a lower steady state when breath rate stabilizes. A gas exchange model was developed and shows excellent fit to breath isoprene measured during exercise. We demonstrated that atorvastatin therapy leads to a decrease in serum cholesterol and LDL levels and a parallel decrease in breath isoprene levels. This work suggests that there is constant endogenous production of isoprene during the day and night, and reaffirms the possibility that breath isoprene can be a non-invasive marker of cholesterologenesis, if care is taken to measure breath isoprene under standard conditions. The third part of the thesis presents results out of the field of food chemistry. The effectiveness of thermal deactivation of the enzyme allinase is demonstrated using breath analysis after eating garlic. With highly time resolved measurements we succeeded in monitoring reactions occurring when garlic is crushed and in distinguishing between aerobic and anaerobic steps. (author)

  6. Prediction of size and position of fracture relevant defects of samples fatigued in the VHCF area on the basis of metallographic examinations; Vorhersage der Groesse und der Lage bruchrelevanter Defekte von im VHCF-Bereich ermuedeter Proben auf Basis metallographischer Untersuchungen

    Energy Technology Data Exchange (ETDEWEB)

    Christ, Hans-Juergen; Grigorescu, Andrei; Kolyshkin, Anton [Siegen Univ. (Germany). Inst. fuer Werkstofftechnik; Kaufmann, Edgar [Siegen Univ. (Germany). Dept. Mathematik; Zimmermann, Martina [TU Dresden (Germany). Inst. fuer Werkstoffwissenschaft

    2016-07-15

    This paper aims to examine the connection between the material quality with regard to the size and spatial distribution of the defects and the size or position of the defects causing the fracture which determine the durability of components in the range of Very High Cycle Fatigue (VHCF). For this purpose, the quality of the metastable austenitic steel 1.4301 was characterized via metallographic examinations. Longitudinal and cross sections were taken from a sheet steel. Afterwards size and position of all defects were measured. The metallographic information acquired was used to create a statistical defect distribution model. On the basis of this model and the stress distribution in the most stressed area of the used fatigue samples, the distribution of size and position of the inclusions relevant for the fatigue failure could be predicted. The results of the modelling are in good agreement with the experimental observations regarding the positions of crack initiation on samples failing under VHCF circumstances.

  7. Studies on the widening of the variation of the fatty acid pattern in flax (Linum usitatissimum L. ) by means of interspecific hybridisation and in-vitro techniques. Untersuchungen zur Erweiterung der genetischen Variation des Fettsaeuremusters beim Lein (Linum usitatissimum L. ) mit Hilfe von Artkreuzungen und in vitro Techniken

    Energy Technology Data Exchange (ETDEWEB)

    Nickel, M.

    1993-01-01

    Oil flux genotypes with strongly divergent fatty acid compositions of the seed oil are vegetable raw materials of great interest to industrial users, notably to manufacturers of edible oils and dietetic products. Compared with the moderately variable fatty acid pattern of Linum usitatissimum that of wild forms shows a far greater scatter. The studies on the widening of the genetic variation of the fatty acid pattern in cultivated flax by means of interspecific hybridization and embryo cultures have revealed the possibilities offered by, and limits to, these methods. Optimisation of the embryo culture techniques have for the first time made it possible to regenerate plants from globular embryos obtained by interspecific hybridization between Linum usitatissimum and L. monogynum. (orig./EF)

  8. Studies on the use of SIR-C and X-SAR data for identification, demarcation, and assessment of forest ecosystems. Final report; Untersuchungen zum Einsatz von SIR-C und X-SAR Daten fuer die Identifizierung, Abgrenzung und Beurteilung von Waldoekosystemen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Johlige, A.; Foerster, B.; Ammer, U.

    1997-12-31

    The purpose of the present evaluation was to use SIR-C and X-SAR data for forest surveying and assess their suitability for this task. Amongst other work this included the discrimination of forest and non-forest, demarcation of cleared areas within forests, discrimination of different forest types, and assessment of the influence of foliation. The chief steps of the study were the preparation of radar data, accompanying aerial photo evaluation for the extraction of training and verification areas, and detailed signature analysis. Evaluation trials in ``Oberpfaffenhofen`` supertest area yielded unsatisfactory results when it came to discriminating different forest ecosystems. This can be attributed to the very heterogeneous and small-scale structure of the area and the absence of topographically coded X, C, and L band data. In the second study area, located in the ``Bavarian Forest National Park``, geocoded data of all three bands were available in the form of combined products. This permitted using the mask of the local angles of incidence to reduce the influence of relief. In this case distinguishability within wooded regions was also enhanced. A general finding was that ground resolution as it presents to the user is clearly poorer than the nominal resolution. What impressed us most was the high degree of weather-independence of the radar data. All data handled in this study were recorded under conditions that would have made photography impossible. (orig.) [Deutsch] Ziel der Auswertung ist es SIR-C/X-SAR Daten fuer die Waldbeobachtung einzusetzen und ihre Eignung dafuer zu bewerten. Zu loesende Teilaufgaben waren u.a. die Wald-Nichtwaldtrennung, die Abtrennung unbestockter Flaechen im Wald, Unterscheidung verschiedener Waldtypen selbst und die Beurteilung des Einflusses des Belaubungszustndes. Die zentralen Arbeitsschritte waren die Aufbereitung der Radardaten, die begleitende Luftbildauswertung zur Extraktion von Trainings- und Verifizierungsgebieten und die detailierte Signaturanalyse. Die Auswertungen im Supertestgebiet `Oberpfaffenhofen` fuehrten zu unbefriedigenden Ergebnissen bei der Unterscheidung verschiedener Waldoekosysteme. Als Gruende hierfuer werden die sehr heterogenen und kleinraeumigen Strukturen des Gebietes und das Fehlen von gelaendegeokodierten X, C- und L-Banddaten angesehen. Im zweiten Untersuchungsgebiet `Nationalpark Bayerischer Wald` standen in Form von Kombiprodukten geokodierte Daten aller drei Baender zur Verfuegung. Dadurch war eine Verminderung des Reliefeinflusses unter Einsatz der Maske der lokalen Einfallswinkel moeglich. Auch zeigte sich in diesem Fall eine erhoehte Unterscheidbarkeit innerhalb der bewaldeten Gebiete. Generell bleibt jedoch festzustellen, dass die tatsaechliche Bodenaufloesung fuer den Nutzer deutlich hinter der nominellen Aufloesung zurueckbleibt. Am meisten beeindruckt hat uns die hohe Wetterunabhaengigkeit der Radardaten. Alle hier bearbeiteten Daten entstanden unter Wetterbedingungen, bei denen optische Aufnahmen unmoeglich waren. (orig.)

  9. Studies on the 'air-grass-cow-milk' exposure pathway of airborne /sup 131/I from Wuergassen nuclear power plant in the 1980 grazing season. Untersuchungen zum Expositionspfad 'Luft-Gas-Kuh-Milch' fuer Jod 131 in der Abluft des Kernkraftwerkes Wuergassen waehrend der Weidezeit 1980

    Energy Technology Data Exchange (ETDEWEB)

    Haubelt, R; Burkhardt, J

    1983-12-01

    The measurements and statistics, which were much more detailed than the annual routine measurements, included /sup 131/I emission measurements on the stack, the registration of meteorological parameters, measurements of /sup 131/I concentrations in air, grass, and milk, and supplementary statistics on the farmers' animal keeping habits. The infant thyroid dose resulting from /sup 131/I in milk was found to be lower by at least one order of magnitude than the value calculated from the emission data for the point of maximum exposure according to the Guideline to Explain Sect. 45 StrlSchV. This result confirms the results of earlier investigations. The model calculation according to the Guideline yields a value of 30 mrem for incorporation of /sup 131/I into the infant thyroid via the ingestion pathway for the year 1980, i.e. 25 times the measured value. The possible reasons for this are discussed.

  10. Experimental and numerical analysis of the static and dynamic crack growth resistance behaviour of structural steels in the temperature range from 20 C to 350 C; Experimentelle und numerische Untersuchungen des statischen und dynamischen Risswiderstandsverhaltens verschiedener hoeherfester Baustaehle im Temperaturbereich von 20 C bis 350 C

    Energy Technology Data Exchange (ETDEWEB)

    Aurich, D.; Gerwien, P.; Huenecke, J.; Klingbeil, D.; Krafka, H.; Kuenecke, G.; Ohm, K.; Veith, H.; Wossidlo, P. [Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin (Germany); Haecker, R.; 1

    1998-11-01

    The crack growth resistance behaviour of the steels StE 460 and 22NiMoCr3-7 was determined in the temperature range from 23 C to 350 C by means of C(T), M(T), and ISO-V specimens tested under quasistatic and dynamic loads. The Russian steel 15Ch2NMFA-A was tested at room temperature and 50 C. In the steels StE 460 and 22 NiMoCr3-7, the minimum crack growth resistance is observed at about 250 C, with measured values always being higher for the latter steel type. The crack growth resistance behaviour of the tested materials correlates with the behaviour of flow curve, yield strength, and notch impact toughness as a function of temperature. Impact tests of ISO-V specimens give higher crack resistance values than quasistatic load tests, and the temperature dependence is significantly lower than those of specimens tested under static loads. A metallurgical analysis of the materials shows the causes of the dissimilar behaviour. The stretching zones determined for the C(T) specimen correspond to the toughness of the steels examined, and they are not much influenced by the temperature. The numerical analysis using damaging models for simulation of ductile crack growth is reported for all specimen types and two different temperatures each. (orig./CB) [Deutsch] Mit C(T)-, M(T)- sowie quasistatisch und dynamisch geprueften ISO-V-Proben wurde das Risswiderstandsverhalten fuer die Staehle StE 460 und 22NiMoCr3-7 im Temperaturbereich von 23 C bis 350 C ermittelt, waehrend der russische Stahl 15Ch2NMFA-A fuer Raumtemperatur und fuer 50 C untersucht wurde. Das Minimum der Risszaehigkeit stellt sich bei StE 460 und 22 NiMoCr3-7 um etwa 250 C ein, wobei die Werte fuer den 22NiMoCr3-7 bei allen Temperaturen wesentlich hoeher liegen als beim StE 460. Dabei korreliert das Risswiderstandsverhalten der untersuchten Werkstoffe mit dem Verhalten von Fliesskurven, Streckgrenzen und Kerbschlagzaehigkeiten in Abhaengigkeit von der Temperatur. Schlagartig beanspruchte ISO-V-Proben liefern hoehere Risswiderstandswerte als quasistatisch beanspruchte. Ebenso ist ihre Temperaturabhaengigkeit deutlich geringer im Vergleich zu den statischen Risswiderstandskurven. Eine metallkundliche Analyse der Werkstoffe zeigt die Ursachen fuer das unterschiedliche Risswiderstandsverhalten auf. Die fuer die C(T)-Probe ermittelten Stretchzonenweiten entsprechen dem Zaehigkeitsverhalten der untersuchten Staehle. Die Stretchzonenweite wird nicht signifikant durch die Versuchstemperatur beeinflusst. Die numerische Analyse mit Schaedigungsmodellen zur Simulation duktilen Rissfortschritts wird fuer alle Probenformen bei zwei unterschiedlichen Temperaturen durchgefuehrt. (orig./MM)

  11. Studies and modelling in the formation, growth, and separation behaviour of spheric and fibrous aerosols in the sub and super-micron range in technical processes by heterogeneous nucleation, heterogeneous multicomponent condensation; Untersuchungen und Modellbildung zum Bildungs-, Wachstums- und Abscheideverhalten von sphaerischen und faserfoermigen Aerosolen im sub- und supermikronen Groessenbereich in verfahrentechnischen Prozessen durch heterogene Nukleation, heterogene multikomponenten Kondensation

    Energy Technology Data Exchange (ETDEWEB)

    Haep, S.; Schmidt, K.G. [Duisburg Univ. (Gesamthochschule) (Germany). Fachgebiet Verfahrenstechnik/Umwelttechnik]|[Institut fuer Umwelttechnologie und Umweltanalytik e.V., Duisburg (Germany)

    1998-12-31

    This work`s scientific interest focuses on the study of the complex interactions of the phases in condensation processes in aerosol systems, both as a basis for `primary` separation techniques for particles of a given geometry, such as, for instance, asbestos fibres, and for the optimization of absorption processes, where particle elimination is a `secondary` effect. (orig.) [Deutsch] Im Mittelpunkt des wiss. Interesses dieser Arbeit steht daher die Untersuchung des komplexen Zusammenwirkens der Phasen bei Kondensationsvorgaengen in Aerosolsystemen sowohl als Grundlage fuer ein `primaeres` Abscheideverfahren fuer Partikeln beliebiger Geometrie, wie z.B. Asbestfasern, als auch fuer die Optimierung von Absorptionsprozessen, wo die Partikelabscheidung als `sekundaerer` Effekt nicht vorrangig im Mittelpunkt des Verfahrens steht. (orig.)

  12. Dose management for X-ray and CT. Systematic comparison of exposition values from two institutes to diagnostic reference levels and use of results for optimisation of exposition; Dosismanagement fuer konventionelles Roentgen und CT. Systematischer Vergleich der Expositionswerte zweier radiologischer Institute mit den diagnostischen Referenzwerten und Verwendung der Ergebnisse zur Optimierung der Strahlenexposition bei diagnostischen Untersuchungen

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, S.; Alejandre-Lafont, E.; Krombach, G.A. [University Hospital Giessen (Germany). Dept. of Radiology; Schmidt, T. [University Hospital Giessen (Germany). Dept. of Neuroradiology; Gizewski, E.R. [University Hospital Innsbruck (Austria). Dept. of Neuroradiology; Fiebich, M. [University of Applied Sciences, Giessen (Germany). Inst. of Medical Physics and Radiation Protection

    2014-08-15

    Purpose: In 2 institutions exposure values were evaluated and compared with the 2010 updated diagnostic reference levels (DRL) and possibilities for decreasing the dose assessed. Materials and Methods: Mean exposure values obtained during a 3-month period were calculated for all modalities (X-ray: imaging plate system and digital detector; dual-source 64- and 16- slice spiral CT) as well as examination types were compared to old diagnostic reference levels in addition to DRLs introduced in 2010. Then 10 examinations of all modalities and types were accompanied by a medical physicist and optimized stepwise if necessary. Results: The mean values of X-ray examinations were above DRL. All accompanied examinations were beyond DRL except lateral lumbar spine (LSP) and lateral thoracic X-ray, which were elevated due to statistical outliers from morbidly obese patients or patients with metallic implants. For a-p LSP tube voltage was increased. While image quality was maintained, dose area product (DAP) was reduced by 50% to 123 ±61 cGy.cm{sup 2} for LSP a-p and 30% for lateral LSP to 229 ± 116 cGy.cm{sup 2}. For CT examinations, dose was below DRL. Accompanied examinations of the lumbar spine performed on a 16-slice spiral CT demonstrated a result 68% above DRL with dose length product (DLP) of 840 ± 252 cGy . cm. For optimization, pitch and tube voltage were stepwise increased and DLP reduced below DRL. Conclusion: Systematic analysis of our internal exposure values on the occasion of adaptation of DRL is crucial for prompt detection of exceeded values independently from assessment by the responsible authority and initiation of proper measures for decreasing exposure dose. Hereby active dose management is attained. (orig.)

  13. Thermoluminescence and chemiluminescence measurement as routine screening method for identification of irradiated spices. Studies to establish limiting values for differentiation of irradiated and non-irradiated samples. Thermolumineszenz- und Chemilumineszenzmessungen als Routine-Methoden zur Identifizierung strahlenbehandelter Gewuerze. Untersuchungen zur Festlegung von Grenzwerten fuer die Unterscheidung bestrahlter von unbestrahlten Proben

    Energy Technology Data Exchange (ETDEWEB)

    Heide, L; Albrich, S; Mentele, E; Boegl, W

    1987-04-01

    The reported experiments with non-irradiated and ..gamma..-irradiated spices of different origin were conducted to determine the variation in chemiluminescence and thermoluminescence intensity for each individual spice. 29 spices from 7 to 10 different manufacturers have been examined, taking into account the influence of storage time. In order to evaluate the methods, the results are represented in diagrams and tables enabling light emission limits to be given for differentiation between irradiated and non-irradiated samples. The final section of this report contains a conclusive evaluation of the present state of chemiluminescence and thermoluminescence analysis for the detection of irradiated spices.

  14. Spectroscopic investigations on the complexation of Cm(III) and Eu(III) with organic model ligands and their binding mode in human urine (in vitro); Spektroskopische Untersuchungen zur Komplexbildung von Cm(III) und Eu(III) mit organischen Modellliganden sowie ihrer chemischen Bindungsform in menschlichem Urin (in vitro)

    Energy Technology Data Exchange (ETDEWEB)

    Heller, Anne

    2011-10-26

    In case of incorporation, trivalent actinides (An(III)) and lanthanides (Ln(III)) pose a serious health risk to humans. An(III) are artificial, highly radioactive elements which are mainly produced during the nuclear fuel cycle in nuclear power plants. Via hazardous accidents or nonprofessional storage of radioactive waste, they can be released in the environment and enter the human food chain. In contrast, Ln(III) are nonradioactive, naturally occurring elements with multiple applications in technique and medicine. Consequently it is possible that humans get in contact and incorporate both, An(III) and Ln(III). Therefore, it is of particular importance to elucidate the behaviour of these elements in the human body. While macroscopic processes such as distribution, accumulation and excretion are studied quite well, knowledge about the chemical binding form (speciation) of An(III) and Ln(III) in various body fluids is still sparse. In the present work, for the first time, the speciation of Cm(III) and Eu(III) in natural human urine (in vitro) has been investigated spectroscopically and the formed complex identified. For this purpose, also basic investigations on the complex formation of Cm(III) and Eu(III) in synthetic model urine as well as with the urinary relevant, organic model ligands urea, alanine, phenylalanine, threonine and citrate have been performed and the previously unknown complex stability constants determined. Finally, all experimental results were compared to literature data and predictions calculated by thermodynamic modelling. Since both, Cm(III) and Eu(III), exhibit unique luminescence properties, particularly the suitability of time-resolved laser-induced fluorescence spectroscopy (TRLFS) could be demonstrated as a method to investigate these metal ions in untreated, complex biofluids. The results of this work provide new scientific findings on the biochemical reactions of An(III) and Ln(III) in human body fluids on a molecular scale and contribute to a better understanding of the known macroscopic effects of these elements. Furthermore, they are the basis of subsequent in vivo investigations. (orig.)

  15. Establishment and use of a combined test system for assessing the toxicity of environmentally relevant pollutants in soil.- Optimization of keeping conditions in the laboratory and bionomic investigations. Final report; Etablierung und Anwendung eines kombinierten Testsystems zur Beurteilung der Toxizitaet umweltrelevanter Schadstoffe in Boeden. Optimierung der Laborhaltung und bionomische Untersuchungen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Dunger, W.; Mattern, D.; Reise, H.; Schulz, H.J.; Barth, V.; Roemer, M.; Voigtlaender, K.; Zimdars, B.

    1997-12-31

    In order to establish how organisms can be kept with low stress or free of stress in the laboratory, test species from the Oberlausitz region were chosen. The species belong to the groups of soil-living organisms Collembola, Isopoda, and Gastropoda. Keeping results may be considered as confirmed and as suitable for stress investigations. Successful optimization of keeping is only possible for a single species in each case (generalists excepted).- As applicable vital parameters both to confirm keeping success and to assess the impact of sublethal doses of stressors (heavy metals, insecticides), the following were established (in this order of sequence): reproductive success, growth (change of biomass, sloughing), mortality and, with restrictions, activity (running and foraging activity).- As expected, the effect of the heavy metals used was found to depend on their concentration. Increased mortality as a rule was only found in the wake of cadmium contaminations; reduced growth and, especially, reduced reproduction was triggered also by lead and zinc contaminations. With this regard, subtle differentiations were established. Use of Lindan in the specified dosage proved to have almost no impact during the (short) test period. (orig./MG)

  16. Cross-sectional environmental study comparing two highly polluted areas in Germany (Bitterfeld and Hettstedt) with a control region; Umweltmedizinische Untersuchungen im Raum Bitterfeld, im Raum Hettstedt und einem Vergleichsgebiet 1992-2000. Bd. 1: Textband. Bd. 2: Publikationen. Bd. 3: Untersuchungsdokumente und Frageboegen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Heinrich, J.; Frye, C.; Hoelscher, B.; Meyer, I.; Pitz, M.; Cyrys, J.; Schneller, H.; Wjst, M.; Wichmann, H.E.

    2001-10-01

    The aim of the environmental epidemiologic study was to determine possible negative effects on the health of children in the very polluted areas of Bitterfeld and Hettstedt in comparison to the less polluted areas of Anhalt-Zerbst (Eastern Germany). The time changes of the health parameters were recorded along with the running redevelopments during the time period of 6 years. The study design consisted of three repeated regional cross sectional studies in 1992/93, 1995/96 and 1998/99. In all, there was information of 7.611 questionnaires to be analysed (participation rate: 89%, 75% and 75%). Children living in the most polluted area of Hettstedt had a noticeable higher risk for non allergic respiratory diseases and symptoms compared to children living in the control area of Anhalt-Zerbst. During the time of the examinations in 1992 till 1999 a clear statistically significant decrease in the prevalences of these restrictions of health could be shown. Children without indoor pollutants in their homes profited most by the improvement of ambient air quality. The better lung function (FVC, FEV{sub 1}) between 1992 and 1999 underlines the improvement of the respiratory health. Children living in both polluted ares have allergies more often (physician's diagnosis, symptoms, allergy specific antibodies). The incidence of asthma, the bronchial hyperreactivity and atopic exzema increased, the prevalence of rhinitis and allergic sensitization did not increase. The body burden with lead and cadmium was higher in children living in polluted areas, but it decreased during the period of observation. In 1997, however, the lead concentration in blood increased a little, parallel to the higher lead concentration in settled dust in Hettstedt at that time. (orig.) [German] Ziel der umweltepidemiologischen Studie war es, moegliche gesundheitliche Beeitraechtigungen von Kindern in den Belastungsgebieten Bitterfeld und Hettstedt i. Vgl. zu dem wenig belasteten Gebiet Anhalt-Zerbst zu ermitteln. Darueber hinaus wurden die zeitlichen Veraenderungen der Gesundheitsparameter begleitend zu den laufenden Sanierungsmassnahmen ueber den Zeitraum von 6 Jahren erfasst. Das Studiendesign bestand aus 3 wiederholten regionalen Querschnittsuntersuchungen in den Jahren 1992/93, 1995/96 und 1998/99. Insgesamt lagen Informationen von 7611 Frageboegen zur Auswertung vor (Beteiligungsrate: 89%, 75% bzw. 75%). Fuer die Belastungsregion Hettstedt waren deutlich hoehere Risiken fuer nicht allergische respiratorische Erkrankungen und Symptome im Vergleich zu Kindern des Kontrollgebietes Anhalt-Zerbst nachweisbar. Waehrend des Untersuchungszeitraumes 1992-1999 zeigte sich eine deutlich statistisch signifikante Abnahme der Praevalenz dieser gesundheitlichen Einschraenkungen, Kinder ohne Exposition mit Innenraumschadstoffen im haeuslichen Bereich profitieren von der Verbesserung der Aussenluftbelastung am meisten. Fuer die Verbesserung der Atemwegsgesundheit sprachen auch bessere Lungenfunktionswerte (FVC, FEV{sub 1}) im Laufe des Beobachtungszeitraumes 1992-1999. Kinder aus den beiden Belastungsregionen hatten haeufiger Allergien (Arztdiagnose, Symptome, allergenspezifischer Antikoerper-Nachweis). Die Haeufigkeit des Asthmas, der bronchialen Hyperreaktivitaet und der Neurodermitis nahm zu; die Praevalenz des Heuschnupfens und der allergischen Sensibilisierung nicht. Die korporale Belastung mit Blei und Cadmium war bei Kindern in den belasteten Regionen erhoeht, nahm aber im Verlauf des Beobachtungszeitraumes ab. Allerdings folgten gestiegenen Bleigehalten im Sedimentationsstaub in Hettstedt im Jahre 1997 leicht gestiegene Blutbleikonzentrationen. (orig.)

  17. Fabrication of ultra-thin cerium oxide layers on Ru(0001) single crystal surfaces. Scanning tunneling microscopic and photoelectron spectroscopic studies on growth, structure and properties; Herstellung ultraduenner Ceroxidschichten auf Ru(0001)-Einkristallflaechen. Rastertunnelmikroskopische und photoelektronenspektroskopische Untersuchungen zu Wachstum, Struktur und Eigenschaften

    Energy Technology Data Exchange (ETDEWEB)

    Bouchtaoui, Mustapha

    2016-12-07

    The thesis at hand aims at a study of structure and properties of well-defined ultrathin CeO{sub 2} films supported on Ru(0001). Such systems may serve as model systems in heterogenous catalysis. The epitaxial growth of ceria films on Ru(0001) surface has been achieved by electron beam evaporation of metal Cer at low background oxygen pressure of 10{sup -6} mbar under ultrahigh-vacuum conditions at room temperature. Cerium oxide qualifies for proper oxygen-storage in oxidation reactions, and hence it widely used in heterogenous catalysis. The oxidation begins with the adsorption of CO on the CeO{sub 2}(111) surface, and it ends with participation of lattice oxygen leading to vacancy formation and CO{sub 2} desorption. We investigate the geometric structure by means of scanning tunneling microscopy and low energy electron diffraction. The coverage of 2.5 monolayers (ML) was sufficient to cover the substrate almost completely. We further analysed the interaction of CO with the CeO{sub 2}/Ru(0001) and the Pt/CeO{sub 2}/Ru(0001) systems. During the interaction process the ratio of Ce{sup 4+} and Ce{sup 3+} changes significantly. This ratio change as well as the effect of Pt evaporated onto the surface with respect to the reducibility of CeO{sub 2}/Ru(0001) in CO environment has been studied by X-ray photoemission spectroscopy and it has been confirmed with thermal desorption spectroscopy. It is revealed that the Pt-Nanoparticles with a height from 7.15 Aa to 9.73 Aa clearly enhances the reducibility of CeO{sub 2}.

  18. Scientific-technical studies on the nuclear safety and effectiveness of regulatory systems abroad (particularly in Eastern Europe and at INSC partners). Reactor construction lines and knowledge networks (LV-2); Wissenschaftlich-technische Untersuchungen zur nuklearen Sicherheit und Wirksamkeit regulatorischer Systeme im Ausland (insbesondere in Osteuropa und bei INSC-Partnern). Reaktorbaulinien und Wissensnetze (LV-2)

    Energy Technology Data Exchange (ETDEWEB)

    Richter, Wolfgang; Tosch, B.; Teske, H.; and others

    2017-06-15

    Within the BMUB project 3614R01520 with a term from 01.12.2014 to 31.05.2017, GRS has continued its work on the analysis and evaluation of nuclear safety, radiation protection and the effectiveness of regulatory systems abroad. This was done both by means of our own scientific and technical investigations as well as by our participation in international activities on questions of nuclear safety abroad as well as by tracking the development of selected new reactor concepts and the regulatory framework. The collection, elaboration, further development and maintenance of the necessary knowledge with regard to of nuclear safety abroad (particularly in Eastern Europe and INSC partners) was systematically continued. Other work packages were focused on the adaptation and pilot application of modern analytical methods and GRS programs to reactor plants of Russian design, as a rule together with competent partner organizations from the respective countries, as well as on the conceptual development of knowledge management methods and cooperation platforms. This work also included the pilot testing of selected suitable instruments for knowledge management. The present final report summarizes the results obtained in the 17 work packages of the project.

  19. Study on the safety during transportion of radioactive materials. Pt. 3. Coverage of the inspection conditions for packages. Final report work package 3; Untersuchungen zur Sicherheit bei der Befoerderung radioaktiver Stoffe. T. 3. Abdeckungsgrad der Pruefbedingungen fuer Versandstuecke. Abschlussbericht zum Arbeitspaket 3

    Energy Technology Data Exchange (ETDEWEB)

    Eberhardt, Holger; Eich, Patrick; Sentuc, Florence-Nathalie

    2014-08-15

    The report summarizes the state of science and technology and the inspection request according to the transport regulations SSR-6. The studies concerning different transport modes are evaluated with respect to accident data: air transport, maritime transport, rail transport and road transport. It has been shown that not enough appropriate information is available to quantify the accident probability. The IAEA transport regulations are considered to cover the thermal and mechanical loads to a large extent.

  20. LOREF: Air cooler optimisation with reduction of ice and frost formation - Optimisation of lamella air-coolers/evaporators of air/water heat pumps - Part 1: theoretical and experimental research; LOREF: Luftkuehler-Optimierung mit Reduktion von Eis- und Frostbildung - Optimierung des Lamellenluftkuehlers/Verdampfers von Luft/Wasser-Waermepumpen - Teil 1: theoretische und experimentelle Untersuchungen

    Energy Technology Data Exchange (ETDEWEB)

    Berlinger, L.; Imholz, M.; Albert, M.; Wellig, B.; Hilfiker, K.

    2008-04-15

    The use of air/water heat pumps for heating of houses is progressively increasing. It is to be expected that the average coefficient of performance (COP) can be improved substantially over the next decade. Its success will depend on controlling and reducing the formation of frost and ice which reduce the air flow and the heat and mass transfer in the fin tube evaporator. In the LOREF research project a mathematical-physical simulation program has been developed which permits to calculate the formation of condensate, ice and frost and also the pressure loss of the air as a function of space and time at any condition of the ambient air. The theoretical results have been validated by numerous experiments in which the air temperature and humidity, the temperature difference and the air velocity have been systematically varied. Particular emphasis has been given to the geometries of the fin tube evaporator. Several fin partitions along the cooler have been investigated. Using the simulation program the evaporator of a commercial heat pump was optimized and experimentally compared to the original evaporator. The resulting seasonal performance factors were nearly equal what confirms the small differences obtained by simulations. Nevertheless, the optimized evaporator features advantages in respect of the defrosting with ambient air because of its bigger fin spacing and the resulting decrease in pressure drop. The results of the LOREF research project are now the basis for the overall optimization of air/water heat pumps. (author)

  1. Combinatorial and conventional studies on new highly selective methanation catalysts for the removal of small amounts of CO from hydrogen-rich gas mixtures; Kombinatorische und konventionelle Untersuchungen zu neuen hochselektiven Methanisierungskatalysatoren zur Entfernung geringer Mengen an CO aus wasserstoffreichen Gasgemischen

    Energy Technology Data Exchange (ETDEWEB)

    Kraemer, Michael

    2008-04-15

    New tailor-made catalysts for the purification of hydrogen-rich reformates by the selective methanation of CO were developed using combinatorial methods. The optimization of the catalysts was achieved within 3 or 4 generations while Ni-based oxides generally proved most promising. Conventional validations confirmed the successive enhancement of the materials. All in all, a number of catalysts providing higher CO hydrogenation activities combined with a lower reactivity towards the undesired methanation of the excess CO{sub 2} in comparison to an industrial reference was discovered. The application of numerous characterization techniques to the optimization sequence Ni{sub 100} - Zr{sub 10}Ni{sub 90} - Re{sub 2}Zr{sub 10}Ni{sub 88} - Re{sub 0,6}Zr{sub 15}Ni{sub 84,4} resulted in the following model: The catalysts are present in their as-prepared state as mixed metal oxide, which is (partly) demixed during the reductive pretreatment. The resulting (Re)Ni-particles seem to represent the actual active component while ZrO{sub 2} could stabilize the dispersion. Alloying with Ni, Re seems to modify the surface of the catalyst in such a way that it only marginally interacts with CO{sub 2}. Solo methanation tests unambiguously reveal that the increase in selectivity is not connected to a competition between CO and CO{sub 2} for adsorption sites but is based on a loss of the intrinsic reactivity of the respective samples towards the methanation of CO{sub 2}. (orig.)

  2. Studies on II-VI and III-V semiconductor nanostructures. Introduction of the core/shell/shell structure and development of CdSe nanocrystals in an automatized procedure; Untersuchungen an II-VI und III-V Halbleiternanostrukturen. Einfuehrung der Core/shell/shell-Struktur und Darstellung von CdSe-Nanokristallen in einem automatisierten Verfahren

    Energy Technology Data Exchange (ETDEWEB)

    Mekis, I.

    2005-11-15

    The work in this dissertation is focused on the development and characterization of fluorescent II-VI and III-V-Nanomaterials. Highly luminescent and photostable Nanocrystals with narrow size distributions were prepared. It was shown that nearly monodisperse CdSe-Nanocrystals could be prepared from Cd(Ac){sub 2} and TOPSe in a mixture of TOPO/TOP/HDA/TDPA. Nearly monodisperse CdSe/CdS-Core/shell-Nanocrystals have been prepared in a one-pot-synthesis by injection of H{sub 2}S-Gas into a freshly prepared crude solution of CdSe. The passivation of the CdSe-core with an inorganic shell of CdS resulted in the drastic improvement of the photoluminescence-efficiency of the colloidal solution. Reproducible room-temperature quantum yields reached up to a value of 85%. Photostability investigations have proved the enhanced stability of CdSe/CdS-Nanocrystals compared to CdSe-Nanocrystals under illumination with UV-Light. A novel type of luminescent semiconductor nanocrystal structure has been developed, consisting of a CdSe core and two anorganic shells. Highly fluorescent and nearly monodisperse CdSe/CdS/ZnS- and CdSe/ZnSe/ZnS-Core/shell/shell-nanocrystals have been prepared via organometallic- and acetate-precursors. The Core/she ll/shell particles reached reproducible room-temperature quantum yields up to 85%. Photostability investigations among CdSe-core, CdSe/CdS-Core/shell- and CdSe/CdS/ZnS- Core/shell/-shell-nanocrystals under illumination with UV-light have proved the highest photostability of the Core/shell/shell-particles. The photostabilities of CdSe/ZnSe/ZnS-and CdSe/ZnS-nanocrystals were compared under illumination with intense laser-beam in air. Another part of this work focused on the development of an automated synthesis procedure of CdSe-nanocrystals by constructing and implementing a flow-reactor system. The size and structure of prepared nanocrystals depended considerably on the Cd:Se-precursorratio and the flow-rate. The preparation of CdSe using Cd(Ac)2 and TOPSe in a mixture of TOPO/TOP/HDA/TDPA consequently could be adapted to an automated synthesis procedure. In the last part of this work the preparation of GaAs-nanostructures is discussed. Amorphous nanostructures could be prepared by the use of Ga(C{sub 2}H{sub 5}){sub 3} and Triphenylarsane in a mixture of benzylether and TDPA by adjusting the coordinating force of the reaction mixture but the growth of nanocrystalline material could not be initiated. The preparation of GaAs-Bulk material was sucessful by the use of weakly coordinating solvents, such as TOP. (orig.)

  3. MR Imaging in patients with cardiac pacemakers and implantable cardioverter defibrillators. Consensus paper of the German Cardiac Society and the German Roentgen Society; MR-Untersuchungen bei Patienten mit Herzschrittmachern und implantierbaren Kardioverter-Defibrillatoren. Konsensuspapier der Deutschen Gesellschaft fuer Kardiologie (DGK) und der Deutschen Roentgengesellschaft (DRG)

    Energy Technology Data Exchange (ETDEWEB)

    Sommer, Torsten [DRK Krankenhaus, Neuwied (Germany). Klinik fuer Diagnostische und Interventionelle Radiologie; Bauer, Wolfgang [Deutsches Zentrum fuer Herzinsuffizienz Univ. Wuerzburg (Germany). Med. Klinik und Poliklinik I Univ. Klinikum Wuerzburg; Fischbach, Katharina [Universitaetsklinikum Magdeburg (Germany). Klinik fuer Radiologie und Nuklearmedizin; and others

    2017-03-15

    This joint consensus paper of the German Roentgen Society and the German Cardiac Society provides physical and electrophysiological background information and specific recommendations for the procedural management of patients with cardiac pacemakers (PM) and implantable cardioverter defibrillators (ICD) undergoing magnetic resonance (MR) imaging. The paper outlines the responsibilities of radiologists and cardiologists regarding patient education, indications, and monitoring with modification of MR sequences and PM/ICD reprogramming strategies being discussed in particular. The aim is to optimize patient safety and to improve legal clarity in order to facilitate the access of SM/ICD patients to MR imaging.

  4. Studies on the influence of processing methods on the corrosion characteristics of electroslag-tape-plating with NiMo16Cr16Ti. Untersuchungen zum Einfluss der Prozessfuehrung auf die Korrosionseigenschaften beim Elektroschlacke-Bandplattieren mit NiMo16Cr16Ti

    Energy Technology Data Exchange (ETDEWEB)

    Blum, J

    1991-01-01

    The aim of the project was to demonstrate an economic possibility of using NiMo16Cr16Ti reliably as a plating material with simple to use methods. For this, the electroslag and submerged arc welding with tape electrodes as a coating technology are compared with each other. As the research showed, it is possible to coat large surface area, thick walled components economically with NiMo16Cr16Ti using electroslag (RES) tape plating. The choice of powder is important for the hot crack freedom and the precipitation poverty and thus the corrosion resistance of the plating. The silicon content was proved to be of importance in the plating. With the right choice of powder, the second layer already possesses the endurance of laminated materials against intercrystalline corrosion in coating tests as well as against pitting in a 10% FeCl{sub 3} solution. The coating capability lies at 0.5 m{sup 2}/h. - In addition the use of video thermography for on-line surveillance of seam on RES plates is documented. The evaluation of the pictures makes possible the targeting of the external magnets and thus the influencing of the melting bath flux. (orig./RHM) With 80 figs., 12 tabs.

  5. Investigation on a-C:H:Me coated substrates as an alternative bipolar plate material in all-vanadium redox-flow batteries; Untersuchungen an a-C:H:Me beschichteten Substraten zur Eignung als alternatives Bipolarplattenmaterial fuer waessrige Vanadium Redox-Flow Batterien

    Energy Technology Data Exchange (ETDEWEB)

    Richards, Justin Frederick

    2015-07-01

    A crucial aspect of advancing in renewable energies is the development of affordable decentralized storage systems for the local or regional distribution grid. A technology with great potential is the all-vanadium redox-flow battery (VRFB) with the distinct feature of individual scalable power and capacity. The present work focusses on one of the essential parts in the redox-flow cell; the bipolar plates. By the application of metallic substrates instead of state-of-the-arte graphite composite plates, the design of the cell isn't limited anymore to the mechanical properties or fabrication process of the material. Although metals possess high ductility, which eases the production of such plates, they are prone to corrosion in the high acidic environment of the battery electrolyte. Therefore in this study amorphous carbon coatings (a-C:H) are investigated for corrosion protection. To attain the need of high electrical conductivity the carbon matrices is doped with a metallic element. Preferably refractory metals such as titanium, vanadium, chromium and tungsten were investigated as possible dopants. The electrochemical tests of the samples revealed less degradation the higher the coating thickness was. This can be found on all metallic substrates (material number: 1.4301, 3.7165 and 3.3535). Regarding the hydrogen overpotential, which is an essential value for the suppression of side reactions on the anode, the dominating factor was found to be the sort of doping material as well as the composition of the metallic adhesive layer between coating and substrate. Pores in the coating originate from defects in the substrates as well as from contaminations during the coating process. To understand the degradation mechanism an in-situ-corrosion cell was developed. By the means of these results, delamination could be found to be the predominant factor concerning degradation mechanisms at cathodic potentials. The degradation is initialized at the defects or at the edges of a pore in the coatings, where higher concentrations of metallic carbides are assumed to catalyze hydrogen evolution. SECM measurements proved to be an useful and powerful tool to investigate corrosion at a-C:H:Me coatings at defects which cannot be resolved by light microscopic measurements. The validation of metallic substrates coated with a 6,61 μm a-C:H:Ti (20 at % Ti) on an coldrolled stainless steel strip (1.4301) showed acceptable performance in real laboratory cells. Despite the fact of showing a faster decreasing cell efficiency than the graphite composite plates, the a-C:H:Ti coatings proved to affect the hydrogen evolution overpotential less than the graphite material when cathodically stressed. Although the defect density and size of an a-C:H:Ti coatings on 1.4301 stainless steel has to be reduced, the mechanical properties and also their possibility to be mass produced showed that coated metallic bipolar plates can be an alternative bipolar plate material for all-vanadium redox flow batteries.

  6. Studies on the reactive deposition of TiN{sub x} and TiO{sub x} in a DC magnetron plasma; Untersuchungen zur reaktiven Abscheidung von TiN{sub x} und TiO{sub x} in einem DC-Magnetronplasma

    Energy Technology Data Exchange (ETDEWEB)

    Wrehde, Stefan

    2009-10-30

    In the present thesis experiments in a magnetron coating plasma on the (rea