The development of the space HVAC sector during the past 25 years is reviewed. It is shown how the importance of room climate has increased, as illustrated, e.g., by the concepts of 'thermal comfort', 'comfort', and 'sick building syndrome'. A sequel will be published in the next issue of KK. (orig.) [German] Der folgende Beitrag ist eine Bestandsaufnahme im Hinblick auf technologische Entwicklungen in der Klima- und Lueftungstechnik der letzten 25 Jahre, ein Zeitraum in dem sich einiges veraendert hat. Gleichzeitig wird deutlich, welcher Wandel sich bei der Bedeutung des Raumklimas in Gebaeuden vollzogen hat, indem beispielsweise Begriffe wie ''Behaglichkeit'', ''Komfort'' aber auch ''Sick Building Syndrom'' eine immer groessere Rolle spiel(t)en. Die Fortsetzung in der naechsten ...
The failure rate of dashpots has been determined on the basis of the results of annually recurring function tests on hydraulic dashpots, in order to determine the effects of longer test cycles on the safety of systems GKN I and GKN II. The use of a calculation method made it possible to establish the number of defective dashpots in the system as a whole. A subsequent investigation illustrated the way in which this figure changes when the test interval is increased from four to ten years, and the effects of this on system safety. (orig.) [Deutsch] Zur Ermittlung der Auswirkungen verlaengerter Pruefzyklen auf die Sicherheit der Anlagen GKN I und GKN II wurde, basierend auf Ergebnisse der jaehrlichen Funktionspruefung an hydraulischen Stossbremsen, die Fehlerrate der Stossbremsen bestimmt. Mit Hilfe eines Berechnungsverfahrens konnte die Anzahl maengelbehafteter Stossbremsen in der Gesamtanlage bestimmt werden. Eine anschliessende Untersuchung zeigte, wie sich dieser ...
Nickel-based alloys are presently used as brazing filler metals for components which undergo mechanical stress in corrosive conditions, f. e. heat exchangers. When soldering chrome containing steel parts with nickel based brazing filler metals additionally containing boron and silicon a reaction of chrome and boron can occur. This evolution of chromium borides, depositing on grain boundaries, causes a lack of chrome in the steel part. A drop of the chrome content in the parts below 13 % leads to a loss of corrosion resistance. It is possible to change the microstructure of brazing joints by modification with chromium and molybdenum. Continuous brittle phases could be successfully avoided with this modification. Furthermore it could be shown that the choice of additives, the heating respectively cooling rate and the brazing temperature have important influence on the microstructure evolution and therefore on the mechanical and corrosive properties of joints. (Abstract Copyright [2008], ...
Electric cars can be recharged via charging stations, battery exchange, or induction cable lanes in asphalted roads. The users' wishes remain unexplored, so a number of technologies are competing in this sector.
Already, MR Imaging is superior in diagnostic imaging of joints in many cases; however, there have been recent developments, which are the subjects of this paper. With gradient-echo sequences acquired in 3D technique, it is possible to produce high-resolution images of joints in acceptable scantime, because gradient-echo sequences are less time-consuming than convential SE sequences. With the acquisition of two echoes, phase difference between water and fat protons have to be considered. 3D Imaging is capable of displaying complex pathology in a superior way, which should be useful in preoperative planning. Tissue contrast is altered by fat saturation or magnetization transfer in order to achieve better conspicuity of lesions. Although diagnostic value of some of these options is not yet clear and further clinical studies are needed, they are a promising possibility for improving MR Imaging of the joints. (orig.) [Deutsch] In der Gelenkdiagnostik gibt es einige neuere Entwicklungen in ...
Proactive qualification is today an integral part of the development process for steam turbines used in steam and combined cycle power plants. By providing experimentally based `random` variables, such as the steam path efficiency and blading reliability, it makes a valuable contribution to the economic `random` variables of the power plant, e.g. the rate of return, as viewed by the customer. One of the areas in which proactive product and process qualification plays an important role is the development of LP steam paths. (orig.) [Deutsch] Die proaktive Qualifikation ist heute fester Bestandteil des Entwicklungsprozesses bei Dampfturbinen, die fuer den Einsatz in Dampf- und Kombikraftwerken bestimmt sind. Sie leistet mit Hilfe experimentell ermittelter `Zufalls`-Variablen, wie z.B. Wirkungsgrad der Fluten und Zuverlaessigkeit der Beschaufelungen, einen wertvollen Beitrag zu den fuer die Kunden wichtigen wirtschaftlichen `Zufalls`-Variablen des Kraftwerks, ...
Meltdown and gasification of waste in an oxygen atmosphere ('2sv' process) is an economically efficient alternative to energetic and thermal utilisation of biomass. Organic pollutants are split at temperatures up to 2000 C in a reducing atmosphere. The process uses elements of the oxygen cupola furnace for melting and gasification of many different waste fractions, e.g. polluted waste wood, household refuse and bulk waste, old tyres, light shredder fractions, sewage sludge, etc. [German] Die Sauerstoff-Schmelz-Vergasung ('2sv') stellt eine wirtschaftliche Alternative zur energetischen Nutzung von Biomassen wie auch zur thermischen Abfallverwertung dar. Organische Schadstoffe werden bei diesem neuen Verfahren bei Temperaturen bis zu 2000 C unter reduzierenden Bedingungen aufgespalten. Das Verfahren nutzt Elemente des Sauerstoff-Kupolofens fuer die Schmelzvergasung und eignet sich fuer zahlreiche Abfallarten ...
Full text: The excessive use of chemical pesticides to control agricultural pests is becoming alarming. The objective of this study is to search for biopesticides of plant origin that could be used to control one of the major pest of fruit production; the Mediterranean fruit fly (Ceratitis capitata Wied.). A colony of the Lebanese wild strain of this insect was reared under laboratory condition to provide biological material. The insecticidal activity of the essential oils extracted from aromatic plants in Lebanon was assessed. The tested plants are: Foeniculum vulgare, Thymbra spicata, Artemisia herba alba, Origanum syriacum, Ruta chalepensis, Lavandula stoechas, Salvia fruticosa, Mentha microphylla, Juniperus oxycedrus, Rosmarinus officinalis, Myrtus communis, Laurus nobilis and Ocimum gratissimum. Results show that essential oils isolated from F. vulgare, T. spicata, A. herba alba, O. syriacum and R. chalepensis have promising insecticidal potential. (author)
The microelectronic cable diagnosis is a substantial tool to determine destruction free the residual strength and the lifetime of laid PE/XLPE medium voltage cables. Fundamentals of the ageing diagnosis and a cost reduced inspection concept are the `Isothermal-Relaxation-Current` Analysis and the Neuro-Fuzzy evaluation software. These new tools are able to determine the ageing status of the investigated cable without any references. The authors also show that the test breakdown during the assessment of the ageing status of criterial systems can be reduced by this approach. The cable diagnosis equipment KDA is also useful for the steering of investment as well as for preventive maintenance. (orig.) [Deutsch] Die zerstoerungsfreie dielektrische Kabeldiagnostik kann heute einen wesentlichen Beitrag zur Bestimmung der Restfestigkeit und der Restlebensdauer eines PE/VPE-isolierten Mittelspannungskabels leisten. Basis der Alterungsdiagnose und des Konzeptes zur kostensparenden Pruefung ist ...
Internal combustion engines with mechanically driven superchargers are known for good performance at low engine speeds and fast response times under fluctuating loads. Application engineers can choose between superchargers with and without internal compression - the familiar roots (blower) type or true compressors - for supercharging an internal combustion engine. This article by DaimlerChrysler describes two options for improving the partial load behaviour of mechanically supercharged internal combustion engines with compressors. (orig.) [German] Die Aufladung mit mechanisch angetriebenen Verdraengerladern zeichnet sich durch guten Druckaufbau bei niedrigen Drehzahlen und gute Dynamik bei Lastwechseln aus. Fuer die Applikation am Verbrennungsmotor koennen Maschinen ohne innere Verdichtung - wie die bekannten Roots-Geblaese - oder Maschinen mit innerer Verdichtung - Kompressoren im eigentlichen Sinne - zum Einsatz kommen. In diesem Beitrag von DaimlerChrysler sind ...
The rate at which full-scale technology transfer takes place depends on the quality of the supply companies, i.e. training, organisational development and product infrastructure. These parameters are discussed for the example of a water mill, and a flow diagram is presented. [Deutsch] Wie rasch ein umfassender Transfer in Frage kommt, entscheidet sich mit der Qualitaet und dem Niveau der zuliefernden Betriebe. Hierbei sind Ausbildung, Organisationsentwicklung und Produktionsinfrastruktur besonders angesprochen. Fuer eine Wassermuehle werden diese Parameter konkret eroertert und an Durchlaufdiagrammen erlaeutert. (GL)
A Paderborn group of builder-owners decided in favour of so-called concrete core activation or isothermal component tempering as an alternative to conventional air conditioning. Results are now available for the first year of operation. [German] Am eigenen Neubau hat eine Paderborner Bauherrengemeinschaft die sogenannte Betonkernaktivierung - oder wie es die Bauherren nennen, isotherme Baukoerpertemperierung - als Alternative zu einer konventionellen Klimaanlage installiert. Inzwischen liegen die Messergebnisse von der ueber einjaehrigen Betriebszeit vor. (orig.)
There are many applications that necessitate reliable and permanent power supply, e.g. power stations, airports, computer centers or hospitals. The stationary battery systems must be monitored by efficient systems, e.g. Batlog. (orig.) [Deutsch] Viele Anwendungen verlangen eine permanent verfuegbare und zuverlaessige Stromversorgung. Kraftwerke, Flughaefen, Rechenzentren oder Krankenhaeuser muessen ihre Prozesse auch bei einem Netzausfall oder einer Versorgungsunterbrechung weiterbetreiben. Dies gelingt nur, wenn sich der entsprechende Energiespeicher in einsatzbereitem Zustand befindet. Die Ueberwachung der stationaeren Batterieanlagen erfordert leistungsfaehige Systeme wie Batlog. (orig.)
Damage survey of protective coats of modern gas turbine blade shows that most damages are not due to classic wear mechanisms such as oxydation or high-temperature corrosion but caused by foreign bodies, poor coating during manufacturing, or operation-caused cracks. Mere visual inspection of cracks is often not sufficient to tell whether cracks are superficial or whether they have already progressed into the base material. Non-destructive methods such as ultrasonic inspection or eddy-current testing are helpful tools but there is not yet a fully matured testing concept at hand. Metallographical tests can give important information about crack mechanisms and thermal, chemical and mechanical stresses.(orig.) [German] Die Schadenerfahrung mit Schutzschichten moderner Gasturbinenschaufeln zeigt, dass die meisten Schaeden nicht auf die klassischen Verbrauchsmechanismen wie Oxydation und Hochtemperaturkorrosion zurueckzufuehren sind, sondern durch Fremdkoerper, ...
Modern commercial alloys are not suited for future steam turbines of operating temperatures beyond 700 C. {gamma}'-hardened alloys like Waspaloy have good mechanical characteristics but have defects when large batches are melted. {gamma}'/{gamma}''-hardened alloys like Inconel 706, on the other hand, are easy to produce but have insufficient microstructural long-term stability and insufficient creep strength. Mixed crystal solidified alloys like Inconel 617 have excessive yield stress at forging temperatures. Two new alloys were therefore developed. Results so far show that they have good production characteristics but insufficient mechanical characteristics. The reasons for this are currently under investigation. (orig.) [German] Die heutigen kommerziellen Legierungen sind nicht geeignet fuer den Einsatz in zukuenftigen Dampfturbinen mit Betriebstemperaturen oberhalb 700 C. {gamma}'-gehaertete Legierungen wie Waspaloy ...
The contribution attempts a definition of the concepts of ``technical facilities`` and ``facility management``. [Deutsch] Um mit der Ueberschrift zu beginnen: Was ist Gebaeudetechnik? Die Antwort ist nicht ganz einfach. An der TU Berlin gibt es einen Ingenieur-Studiengang mit dieser Bezeichnung. Es hat etwas mit dem Gebaeude, aber nicht viel mit Architektur zu tun, wie manchmal faelschlich angenommen wird. Um solche Missverstaendnisse gar nicht erst aufkommen zu lassen, hat sich die Gruppe des Vereins Deutscher Ingenieure, die sich mit der Gebaeudetechnik beschaeftigt, als `VDI-Gesellschaft Technische Gebaeudeausruestung` bezeichnet. (orig.)
ZusammenfassungUbelkeit und Erbrechen stellen zwei Symptome dar, die grundlich untersucht worden sind und bei Krebspatienten haufig auftreten. Die meisten Studien haben sich bislang mit Haufigkeit und Management dieser beiden Symptome befasst. Das Ziel dieser Studie bestand darin, ein besseres Verstandnis dafur zu entwickeln, wie Krebspatienten ihre Symptome erleben-insbesondere Ubelkeit und Erbrechen nach Chemotherapie-und welche Auswirkungen diese Symptome auf den Tagesablauf der Patienten haben. Neun Frauen mit unterschiedlichen Krebsleiden und Chemotherapie Regimes wurden zwecks Chemotherapie stationar aufgenommen und nahmen an der Studie teil. Es wurden halbstrukturierte Interviews einschliesslich einer Inhaltsanalyse in Anlehnung an Kvale durchgefuhrt (Klarung und Entwicklung neuer B...
Facility management has long been regarded as a cost reduction measure, but it is also a means of raising the financial worth of a building so that landlords can get higher rents or sell the building at a better price. [German] Lange Zeit wurde Facility Management als eine Massnahme zur Kostensenkung angesehen. Heutzutage zeigt sich immer mehr, dass das Facility Management sehr viel umfassender zu verstehen ist: Der Wert eines Gebaeudes bemisst sich nicht allein an einer niedrigen Kostenquote, sondern er soll umfassend Investoren wie Mietern den hoechst moeglichen Nutzen bringen. Nicht allein der kostenguenstige Betrieb ist entscheidend, sondern der Wert des Gebaeudes muss insgesamt gesteigert werden. (orig.)
After cooling ceilings and source ventilation, simple air conditioning systems like thermal activation of concrete cores are gaining general acceptance. Parallel to this, ground source cooling systems are reducing the need for cold generation. Air conditioning systems of this type are favoured by producers of floor heating systems looking for a new market segment. [German] Nach Kuehldecken und Quellueftung gewinnen jetzt einfach aufgebaute Raumklimaanlagen, wie die thermische Betonkernaktivierung, immer mehr Anhaenger. Parallel dazu werden Verfahren zur Erdkaeltenutzung entwickelt, die den Anteil kuenstlich erzeugter Kaelte weiter zurueckdraengen. Forciert wird diese Art der Klimatisierung insbesondere durch die Hersteller von Fussbodenheizungen, fuer die sich hier ein neues Marktsegment eroeffnet. (orig.)
Elektrochemische Potentialmessungen (auch Potentialfeldmessungen) haben sich seit Jahren bewahrt, Bereiche mit aktiver chloridinduzierter Korrosion an tausalzexponierten Bauwerken, wie z. B. Bruckentafeln sowie Zwischendecks und Bodenplatten von Parkhausern und Tiefgaragen nachzuweisen. Bereits 1990 erschien die erste Fassung des Merkblatts B3 der DGZfP. Das DAfStb Heft 422 (1991) - Prufung von Beton Empfehlungen und Hinweise zu DIN 1048 - enthielt die Potentialfeldmessung bzw. das Merkblatt B3 im Anhang. In Deutschland liegen somit zwei Jahrzehnte Erfahrungen mit den entsprechenden Regelwerken und naturlich auch in der praktischen Anwendung vor. In der Praxis zeigte sich jedoch auch, dass die Anwendung verbessert werden muss. Die Potentialmessung wurde vielfach sogar falsch durchgefuhrt, ...
More than 200 years after the birth of the steam engine, the first thermal engine ever invented, thermal engines such as steam turbines, gas turbines or internal combustion engines are still driving most generators for electric power generation, most machines, and most vehicles, and this will remain so until far into the next century. (orig.) [Deutsch] Mit Waermekraftmaschinen wie Dampfturbinen, Gasturinen und Verbrennungsmotoren werden auch heute - mehr als 200 Jahre nach der technischen Reife der Dampfmaschine (der ersten Waermekraftmaschine) - die meisten Generatoren zur Stromerzeugung, die meisten Arbeitsmaschinen und die meisten Fahrzeuge angetrieben. Und dabei wird es auch bis weit in das 21. Jahrhundert bleiben. (orig.)
Only two types of 110-kV-cables: Namely XLPE-Cables and External-Gas-Pressure-Cables will be reinstalled in the Federal Republic of Germany. XLPE-Cables have been already developed for higher voltages. An idea how the external-gas-pressure-cable could be made fit for higher voltage levels will be given in this paper. (orig.) [Deutsch] In der Bundesrepublik Deutschland werden in der Zukunft nur noch zwei Kabeltypen der 110-kV-Ebene den Kabelmarkt beherrschen, naemlich: VPE-Kabel und Gasaussendruck-Kabel. Waehrend VPE-Kabel auch fuer hoehere Spannungsebenen bereits entwickelt worden sind, wird im folgenden vorgeschlagen, wie auch das Prinzip der Gasaussendruck-Kabel zu hoeheren Spannungen hin erweitert werden kann. (orig.)
The present contribution focuses on the input side of individual process techniques. It shows on the basis of example calculations how two parameters describing the incinerable (residual) waste that are of particular importance for unconventional thermal treatment methods, namely ``pollutant load`` and ``calorific value``, can be influenced by a recycling stage and then further by mechanical-biological pretreatment. [Deutsch] Im folgenden soll das Hauptaugenmerk auf die Inputseite zu den einzelnen thermischen Verfahren gelegt werden und anhand einer Beispielrechnung aufgezeigt werden, wie sich die fuer einen Einsatz in nichtkonventionellen thermischen Verfahren besonders wichtigen Parameter des aufbereiteten (Rest)Abfalls `Schadstoffbelastung` und `Heizwert` zunaechst durch eine Verwertung und weiter durch eine mechanisch-biologische Vorbehandlung veraendern. (orig./SR)
There are alarming scenarios that state that global heating caused by anthropogenic gaseous emissions will melt the ice caps of Greenland and the Antarctic. This would cause flooding of coastal regions on a global scale. The floods are expected already in the next century, but there are no realistic assessments of the extent of the danger. (orig.) [Deutsch] Alarmierenden Szenarien zufolge koennten durch eine globale Erwaermung, die der Mensch mit dem Ausstoss von Treibhausgasen in die Atmosphaere verursacht, die Eiskappen auf der Antarktis und Groenland abschmelzen. Schon im kommenden Jahrhundert wuerden dadurch weite kuestennahe Gebiete ueberflutet. Noch aber laesst sich schwer abschaetzen, wie real die Gefahr ist. (orig.)
This report describes work carried out in the context of TurboTech Interim for the development of a system for monitoring stationary gas turbines for approaching the stability limit of the compressor. The requirements for the system components were defined and the suitability of different types and positions of pressure sensors were examined and evaluated. It was found very early in the work that, due to the complexity of the object being monitored, one would not succeed in finding a simple criterion for monitoring the pump limit. Rather, apart from the selection of suitable sensors and optimum positions, one must analyse the present signals in different ways and create a decision matrix from this. Existing work on this subject is mostly concerned with the phenomena in the context of experiments on experimental compressors or is not suitable for the requirements of stationary industrial gas turbines. The project is being carried out in the context of TurboTech II with the main aims of: ...
Compared to the reference year of 1990, CO{sub 2} emissions of the Federal Republic of Germany have been curbed by about 12%, primarily as a result of industrial backfitting and pollution abatement measures accomplished in the industrial infrastructure of the new Federal Laender of Germany. Federal Government policy sticks to the previous commitment, to reduce carbon dioxide emissions by 25% by the year 2005. Current forecasts and scenarios of future greenhouse gas emissions show that only immediate adherence to a very stringent reduction policy might ensure that this ambitious goal will be achieved. In this context, any change of the baseline data and scenarios hitherto used for progonostic assessments is a crucial factor, so that the article here discusses the impacts of a change in the nuclear generation scenario, as recently ventilated by the German Federal Government, and expected effects on public power supply. (orig./CB) [Deutsch] Ausgehend von dem Bezugsjahr 1990 sind die ...
Since enterprises operating offices and facilities at geographically distributed sites have been establishing an intranet for inter-office communication at the management level, the idea of integrating another intranet for multi-site technological facility management comes naturally. The Aachen-based technology enterprise Eurem for this purpose developed a Network and Security concept with solutions that can be customized for linking a variety of computerized control and monitoring systems. The package includes a modular substation named modUS, which is open to the field side as well as to the management side, is capable of efficiently and reliably performing the facility management functions by way of remote controlling via intranets. (orig./CB) [Deutsch] Nachdem in den Unternehmen mit verteilten Liegenschaften die unterschiedlichsten Buerokommunikationssysteme ueber eigene Netzwerke verbunden werden, liegt es nahe, auch verteilte Gebaeudeautomationssysteme in diese Vernetzung ...
The amounts of lead and cadmium produced and processed in these days are considerable. As a result, our environment is increasingly polluted by heavy metals and industrial installations, motor vehicles or incinerating plants appear to be among the main culprits here. Air and water are the media permitting the entry of heavy metals into our natural environment where they accumulate in the soil and then gradually migrate into the plants. Their further transport in the food constitutes the third step in the environmental spread of heavy metals. The consumption of muscle and organ meats, of vegetables, fruits, canned food and drinking water is unavoidably associated with some ingestion of lead and cadmium. The degree to which they are taken up and stored in different tissues is determined by absorption properties and the nutritional state of the organism. Cadmium tends to accumulate in the kidneys, lead is mainly stored in the bones. A continuously increasing uptake finally results in ...
Against the background of more severe limitation of particle emission in all application areas of Diesel engines, it is necessary to monitor the particle emission, but also the chemical composition of the particles. The basis of assessing particle emission is formed by gravimetric determination of the particle concentration from exhaust gas diluted with particle-free ambient air, with a maximum temperature of 52 degrees C at the sampling position. While it is already possible, using the part flow dilution system, to take samples locally, previously the subsequent particle determination and characterisation could only be done in a chemical laboratory. For this reason, the C/S particle measurement process was developed as an alternative to gravimetry, which can be used locally, eg: on ships and which makes it possible to determine the particle mass and composition. This process is based on a thermographic carbon and sulphate determination. Comparative investigations were done both on ...
In this study, the bend properties of the single-crystalline molybdenum brazed by using Mo-40%Ru alloys containing boron of 1-6 mass%Ru alloy for the improvement of the joint strength was determined. (orig.) [Deutsch] Durchgefuehrt wurde die Herstellung von Verbindungen aus einkristallinem Molybdaen. Hierbei kamen Mo-40%Ru-Legierungen mit 1 bis 6 Gew.-% Bor als Lotmaterialien zum Einsatz. Festigkeit und Duktilitaet der Verbindungen wurden mittels 3-Punkt-Biegepruefung bei Raumtemperatur und unter fluessigem Stickstoff ermittelt. Die Bruchflaechen der Proben wurden mit Hilfe eines Rasterelektronenmikroskopes untersucht. Die Ergebnisse lassen sich wie folgt zusammenfassen: Der optimale Borgehalt bezueglich Festigkeit und Duktilitaet der geloeteten Verbindung liegt bei 2 Gew.-%. Die entsprechende Probe hat bei einem Biegewinkel von 100 bei Raumtemperatur nicht versagt. Auch unter fluessigem Stickstoff zeigte diese Probe eine Festigkeit in der Groessenordnung des ...
A century of technical development put steam turbines on a high level regarding efficiency and reliability. This procedure is still ongoing. The technological-commercial point of view - influenced intensively by liberalisation of the energy-market - makes great demands on field services. Well suited concepts in service and modernization are the solutions, as shown in NPP Emsland upgrade. [German] Ein Jahrhundert technischer Entwick lung brachte Dampfturbinen auf ein hohes Niveau bezueglich Effizienz und Zuverlaessigkeit. Dieser Vorgang ist auch in der heutigen Zeit nicht ab geschlossen. Die technologisch-wirtschaftliche Betrachtungs weise '' von der Liberalisierung des Strommarktes intensiv beeinflusst '' stellt dementsprechend hohe Anforderungen auch an den Kraftwerksservice. Massgeschneiderte Modernisierungs- und Servicekonzepte sind die Antwort, wie das Beispiel Kernkraftwerk Emsland zeigt. (orig.)
Magnetic fields can be compensated by opposing fields. This principle can be applied for reducing the magnetic fields emanating from high-voltage transmission lines or found in residential or commercial buildings. The article shows a number of concrete options for reducing magnetic fields in the vicinity of high-voltage lines through appropriate conductor configuration on the one hand, and a novel method using Helmholtz coils for compensating those fields in buildings. (orig.) [Deutsch] Magnetische Felder koennen durch Gegenfelder kompensiert werden. Dieses Prinzip laesst sich sowohl auf Hochspannungsleitungen als auch auf Wohn- und Arbeitsraeume uebertragen. Der Artikel zeigt konkrete Moeglichkeiten, wie einerseits Magnetfelder von Hochspannungsleitungen durch eine geeignete Konfiguration der Leiter reduziert werden koennen, und beschreibt andererseits eine neue Methode zur Reduktion solcher Felder in Wohn- und Arbeitsraeumen mittels Helmholtz-Spulen. (orig.)
Within the context of practice-oriented constraints the speed and output power control of power plant turbines represents a big challenge for engineers for designing low order controllers with only a few parameter settings and in order to meet the requirements of the Deutsche Verbundgesellschaft. The results of a detailed study of the current standard and an improvement of the speed dynamic for load rejections are shown. (orig.) [German] Die Regelung der Drehzahl und die Leistung von Kraftwerksturbinen stellt im Rahmen von praxisorientierten Nebenbedingungen, wie z.B. dem Einsatz von Reglern geringer Ordnung mit wenigen Einstellparametern und den Vorgaben der Deutschen Verbundgesellschaft, eine grosse Herausforderung fuer den Entwicklungsingenieur dar. Die Ergebnisse einer ausfuehrlichen Untersuchung des bisherigen Standards und einer Verbesserung der Drehzahldynamik bei sogenannten Abfangpruefungen werden vorgestellt. (orig.)
A computer program for optimization of modular cogeneration plants is introduced. Computer calculation fundamentals are discussed referring to examples which elucidate the verification of the calculated data by measured data or empirical values. The results obtained as one optimizes plants by varying their size or by splitting them into modules are introduced referring to examples. Sensitivity analyses are made to investigate the influence of parameters such as fuel prices, electricity tariffs and interest rates. (orig.) [Deutsch] Im vorliegenden Beitrag wird ein Computerprogramm zur Optimierung von BHKW-Anlagen vorgestellt. Zunaechst werden in einem ersten Schritt die Berechnungsgrundlagen an einem Beispiel in Hinblick auf ihre Ueberpruefung durch Messdaten oder durch Erfahrungswerte diskutiert. Dann werden in einem zweiten Schritt exemplarisch die Ergebnisse einer Optimierung durch Variation der Gesamtanlagengroesse auf Aufsplittung der Anlage in Module vorgestellt. Schliesslich wird ...
Verification of guarantees mostly calls for measurements on the spot. The paper deals with the guarantees that apply to small hydroelectric power stations. Already when planning a plant it should be decided what guarantees are to be demanded and how they can be verified. Specifically, measurements to verify guaranteed performance and efficiency on the spot are dealt with. Details are not given. Rather, the report wants to give an overview of methods and aspects to be taken heed of. For in-depth information, the reader is referred to the corresponding standards and guidelines. (orig.) [Deutsch] Zur Ueberpruefung von Garantien ist meistens die Durchfuehrung von Messungen vorort notwendig. Es werden die Garantien behandelt, die bei Kleinwasserkraftanlagen in Frage kommen. Bereits bei der Planung der Anlage sollte entschieden werden, welche Garantien gefordert werden sollen und wie sie ueberprueft werden koennen. Es wird speziell auf die messtechnische Ueberpruefung ...
Despite successful reduction of the general lead exposure, this heavy metal is still a matter of public concern due to the fact that associations with intellectual impairment or delayed puberty are found to correlate with very low lead blood concentrations. Lead in tap water is still an important contribution to lead exposure which may cause health risk for infants. Therefore, lead pipes should be completely sanitated by exchange against pipes made from more healthy materials. (orig.) [German] Trotz erfolgreicher Reduktion der allgemeinen Belastung ist Blei auch heute noch umweltmedizinisch relevant, weil es moeglicherweise bei niedrigeren als bisher angenommenen Belastungen gesundheitlich nachteilige Wirkungen, insbesondere waehrend der fruehkindlichen Entwicklung des Nervensystems, ausloest. Insbesondere Blei aus bleiernen Trinkwasserleitungen ist eine Belastung, die fuer Saeuglinge und Kleinkinder nach wie vor ein gesundheitliches Risiko darstellen kann. Solche ...
The harnessing and enhanced use of renewable energy today is a matter of lively debate and much concern. Amazingly, hydro power is either rarely considered in these discussions or viewed in a negative light. But hydro power continues to be the most important source of renewable energy, and its use potential is considerable and should be taken into account when, for instance, agreeing on or implementing carbon dioxide reduction targets. Small hydro power stations are an effective means of harnessing existing energy potentials. (orig.) [Deutsch] Ueber die Nutzung und den Ausbau regenerativer Energien wird heutzutage lebhaft diskutiert und gerungen. Es mag erstaunen, dass in diesen Diskussionen die Wasserkraft kaum Beachtung findet oder in einem schlechten Licht gesehen wird. Dabei ist die Wasserkraft nach wie vor bei weitem die wichtigsten Quelle regenerativer Energie, und sie besitzt ein beachtliches Ausbaupotential, das man wenigstens ins Kalkuel ziehen sollte, ...
A good knowledge of medfly population dynamics is necessary to control it. Population dynamics are being studied by means of the Jackson trap with trimedlure attractant (male, sex-pheromone). Weekly sampling of wild medfly populations was started in June at Aabde and in August at Sour and Jbeil. Trap surveys of medfly density will be carried for at least one year before sterile males releases are started against a long-established infestation. Since populations can vary with season and in different parts of an infested area. Knowledge of this variation is needede to determine when releases should start, because they should begin, just after or during a population decline. Field evaluation will include, ecological data on medfly population distribution number, host preference, and medfly overwintering. Surveys of medfly adults and larvae, host species, and phenology, temperature and medfly history, all will be used to guide the control program, specifically the sterile fly releases. 3 ...
The results of these investigations can be summarised as follows: At simulated operating stress most naturally occuring faults in welded- and cast iron parts develop cracks and can be assessed for reliability under fatigue-,creep- and creep fatigue behaviour according to the laws of fracture mechanics. The empirically determined correlation between the real fault size and the ultrasonic inspection results (height of echo, echo dynamics, sound weakening) lead to better assessment of real fault extension in turbine components. It is very important to adapt the method of inspection and assessment to the type of possible fault.(orig.) [German] Die bei diesen Untersuchungen ermittelten Ergebnisse lassen sich wie folgt zusammenfassen: - Die Mehrzahl der untersuchten natuerlichen Fehlstellen in den Schmiede- und Gussstuecken verhalten sich unter den simulierten Betriebsbeanspruchungen rissartig und sind damit mittels den bruchmechanischen Gesetzen in ihrem ...
A team at the Paul Scherrer Institute (PSI) recently achieved a breakthrough in the development of an environment-friendly and rechargeable battery with novel electrodes. The energy storage density of a rechargeable 12 V/20 Ah zinc/air battery could be increased to 100 watt hours per kilogramme - three times as much as conventional lead accumulators. 20-Ah cells could be charged and discharged 55 times in 1000 hours without any loss of capacity worth mentioning. This is a remarkable cycle stability. (orig.) [German] Einem Team des Paul Scherrer Instituts (PSI) ist kuerzlich bei der Entwicklung einer umweltfreundlichen und wiederaufladbaren Batterie mit neuartigen Elektroden der Durchbruch gelungen. Dabei konnte die Energiespeicherdichte einer wiederaufladbaren 12 V/20 Ah-Zink-Luft-Batterie auf 100 Wattstunden pro Kilogramm gesteigert werden - dreimal soviel wie bei konventionellen Bleiakkumulatoren. 20-Ah-Zellen konnten in 1000 Stunden ohne nennenswerte ...
Developments in the past 10 -15 years in the fiels of `steel`, `boilers`, `steam turbines` and `environmental protection` show that the advanced coal dust furnace technology is another option of clean coal technology. The contribution discusses some of the current problems facing the main partners of the coal sector, e.g. coal producers, public utilities and suppliers of steel, boilers and turbines. (orig./GL) [Deutsch] Die Entwicklung der vergangenen 10-15 Jahre in den Bereichen `Stahl`, `Kessel`, `Dampfturbinen` und `umweltschutztechnische Anlagen` verdeutlicht, dass die fortgeschrittene Kohlestaubfeuerungstechnologie ebenfalls eine Option der `Clean Coal Technologies` ist. Im Rahmen dieses kurzen Aufsatzes wird nun versucht, einige zeitgemaesse Problemkreise der Hauptakteure des Strommarktes, wie z.B. des Kohlefoerderers, der Stromproduzenten und der Stahl-, Kessel- sowie Turbinenhersteller anzudeuten. (orig./GL)
The current discussion on worldwide climate change suggests that the current situation is unusual or extreme, and that climate changes never - or hardly ever - occurred in the centuries before. The author discusses whether this is really the case, and whether air pollution abatement measures can really help. His answers are based on the findings of palaeoclimatology. [German] Verfolgt man die Diskussion um den derzeitigen Klimawandel, so gewinnt man den Eindruck, Aussergewoehnliches und Extremes wuerde geschehen, und man bekommt zudem ueber Beratungsgremien und Medien vermittelt, dass sich in den Jahrhunderten vor dem heutigen Klimawandel das Klima nicht oder nur wenig geaendert hat. Es wird auch der Eindruck erweckt, man koenne das Klima stabilisieren und durch Emissionsminderungsmassnahmen das Klima schuetzen. Ist Klimaschutz eine loesbare Herausforderung oder ueberschaetzen wir Menschen unsere Moeglichkeiten? Man kann versuchen, sich an die Beantwortung dieser Frage heranzutasten, ...
The basis of assessment for particulate exhaust emissions is the gravimetric analysis of the particle concentration of diluted exhaust gases at temperatures below 52 C. This is very time consuming and takes sufficient sensitivity at low particulate emission rates like downstream of particle filters. For this reason the C/S-method, based on the thermographic analysis of carbon and sulfur, has been developed as an alternative to the gravimetric anallysis. This method yields particle mass as well as the main particle compounds. Comparisons between both methods have been carried out for heavy duty and automobile diesel engines as well as road vehicles and large diesel engines. The tests were conducted with commercial diesel fuel and also with other fuels, such as heavy oils. It could be shown that the C/S-procedure yields the same results as the gravimetric procedure independent of engine, engine mode and kind of fuel. The analysis of all important particulate compounds - elemental carbon ...
The role of high-resolution computed tomography (HRCT) and magnetic resonance imaging (MRI) in the diagnosis of preoperative and postoperative complications caused by acquired cholesteatomas will be described in this paper. The pre- and postoperative imaging of the temporal bone was performed with HRCT and MRI. HRCT and MRI were performed in the axial and coronal plane. MRI was done with T2 weighted and T1 weighted sequences both before and after the intravenous application of contrast material. All imaging findings were confirmed clinically or surgically. The preoperative cholesteatoma-caused complications depicted by HRCT included bony erosions of the ossicles, scutum, facial canal in the middle ear, tympanic walls including the tegmen tympani, and of the labyrinth. The preoperative cholesteatoma-caused complications depicted by MRI included signs indicative for labyrinthitis, and brain abscess. Postoperative HRCT depicted bony erosions caused by recurrent cholesteatoma, bony defects ...
CT and MRI of acquired abnormalities of the inner ear and cerebello-pontine angle present themselves with very typical findings. The imaging should be adapted to the pathology looked for and either CT or MRI should be used alone or in combination.CT, especially high resolution CT (HRCT), provides an excellent bone contrast, while MRI has a much superior soft tissue contrast. Acute inflammatory changes of the inner ear are solely depicted by contrast-enhanced MRI. HRCT excellently depicts osseous changes of the inner ear and cerebellopontine angle such as chronic ossifying labyrinthitis occurring after acute labyrinthitis, otosclerotic or traumatic changes. Tumorous changes not yielding to bony changes are best delineated by MRI. Posttraumatic hemorrhage and chronic fibrotic changes within the labyrinth are depicted by MRI, only. In conclusion HRCT and MRI are excellent methods to delineate acquired abnormalities of the inner ear and cerebello-pontine angle. HRCT best depicts osseous ...
Wood is currently having a renaissance as a domestic fuel. Wood pellets, usually about 8 mm in diameter and 40 mm long and produced from sawmill and wood processing residues by pressing without binders, are gaining general acceptance. According to a market analysis of Solar Promotion GmbH, Pforzheim, about 4,800 pellet-fuelled heating systems with automatic fuel supply and with a total thermal capacity of 35 kW are in operation in Germany, and 2000 new ones were installed in 2000. [German] Holz als Brennstoff erlebt in vielen Heizkellern und Kaminen eine Renaissance. Und zwar nicht in Form von Holzscheiten, sondern als kleine Presslinge, meist mit einem Durchmesser von acht und einer Laenge von bis zu 40 Millimetern. Als Abfallprodukt von Saegewerken und Holz verarbeitenden Betrieben werden die so genannten Pellets unter hohem Druck und ohne Bindemittel wie beispielsweise Leim hergestellt. Und dieser neue Brennstoff findet immer mehr Anhaenger. So sind im ...
Technical innovations such as the availability of movable patient platforms and the introduction of 32-channel systems have made whole-body MRI for tumor staging feasible. In addition, the development of dual-modality PET/CT systems offers the opportunity to perform anatometabolic tumor staging with whole-body coverage in a single session. Based on an increase in patient survival when applying a stage-adapted therapy in different malignant diseases the relevant question relates to the accuracies of whole-body MRI and whole-body PET/CT for TNM staging. This review article addresses whole-body tumor staging with MRI and FDG-PET/CT with special emphasis on diagnostic accuracies for staging different malignant diseases. (orig.) [German] Technische Neuerungen, wie die Verfuegbarkeit beweglicher Tischaufsaetze oder die Einfuehrung von 32-Kanal-Systemen, haben die Ganzkoerperbildgebung mit der MRT ermoeglicht. Die Entwicklung kombinierter PET/CT-Systeme bereitet den Weg ...
A new emissivity measurement device with inductive sample heating is described. The disc shaped samples can be measured between 800 C and 2000 C in vacuum or in each available gas atmosphere. Two kinds of surface temperature measurement methods are described, one by measuring in a blackbody hole and one by measuring at the surface without additional measures to correct emissivity. Total normal and spectral emissivity at wavelengths between 0,5 {mu}m and 8,3 {mu}m of various high temperature materials like platinum and Pt-Rh-alloys, siliconcarbide and molybdenum disilicide have been measured. From the investigated materials a few have been selected as reference samples for comparative emissivity measurements fullfilling the requirement of stability on air up to 400 C to 1000 C in order to ensure reproducibility of the results at different measurement conditions in air and in vacuum. (orig.) [Deutsch] Der Aufbau einer neuen Messapparatur fuer Emissionsgradmessungen bei Temperaturen ...
Many features from the background for an intensified application of fracture mechanics concepts in many industries world-wide. These include requirements for a permanent increase of the level of performance of technical components and structures by the introduction of new materials, joining technologies and design principles, the problem of ageing components and life extension, an increased emphasis on non-destructive in-service inspection combined with improved NDT techniques, and also a number of failure events caused by fatigue and fracture The aim of the present paper is to give a brief state-of-the-art review on how fracture mechanics is applied in different industrial branches today. This is based on standards and guidelines in the aerospace industry, in the nuclear and fossil power generation, in the chemical and petrochemical and the pipeline industry, in civil engineering, offshore technique and other fields. Based on the review an outlook is given on a future development that ...
The research project's objective is to create a decision help for owners of residential buildings for several families regarding the renewal of decentralized heating and warm water preparation systems in the flats. The focus lies on a comparison of the costs of typical systems on the basis of a full cost calculation. This is done by taking into consideration the intentions of residential building companies like the reduction of additional costs to be paid by the tenants (both for social reasons and to make the flats easier to rent), low investment costs, low maintenance costs, energy saving, tenants' claims for comfort and acceptance by the tenants, economical reasons, especially regarding flats fully amortized (activation in the balance sheet). In addition to the quantitative comparison, the advantages and disadvantages of the different systems were also compared to one another from the qualitative point of view. [German] Ziel des Forschungsvorhabens ist die ...
Blades of modern steam turbines are designed for high efficiency and operational safety. Modern computer programs enable optimisation of design but factors like manufacturing, assembly, operation and downtimes still play an important role. Damage statistics show that blade damage still quite frequent. Selected cases from the Allianz damage assessment centre show some of the more frequent damage mechanisms. Damage is often caused when several factors come together. Prevention of follow-up damage requires early identification of beginning damage.(orig.) [German] Die Auslegung der Beschaufelung moderner Dampfturbinen hat die Vorgabe, einen hohen Wirkungsgrad bei gleichzeitig hoher Betriebssicherheit zu erreichen. Mit den heute zur Verfuegung stehenden Rechenprogrammen ist eine entsprechende Optimierung realisierbar. Fuer die langzeitige Betriebsbewaehrung haben aber Einflussgroessen aus Fertigung, Montage, Betrieb und Stillstand auch heute noch die gleiche Bedeutung ...
The high-strength and ultra high-strength steels developed and produced by Thyssen Krupp Stahl make a major contribution to automotive lightweighting. Proven and newly-developed coatings are used to meet increasingly important corrosion protection requirements. Design for materials, optimized forming and joining processes and the use of modern simulation techniques help to exploit the potential of the new steels. Future development work will focus on reducing the density of steels without compromising their well-known advantages - in particular their strength. The use of high-strength and ultra high-strength steels in the automotive industry is on the increase. Steel will remain the material of choice for auto manufacture, above all due to its potential for cost-efficient lightweight construction and its full recyclability. (orig.) [German] Einen wesentlichen Beitrag zum Leichtbau im Automobil leisten die von Thyssen Krupp Stahl entwickelten und hergestellten hoeher- und hoechstfesten ...
The presented paper describes the formulation of the fractional mass balances which are used to calculate the concentration and size distribution of char in the balance cells of a circulating fluidized bed boiler. In case of using the shrinking core model additionally the distribution of conversion of the char particles is calculated. Basically two reaction models (a shrinking particle and a shrinking core model) are available to describe the combustion process. The model considers all essential physico/chemical phenomena (primary fragmentation, attrition, mass transfer to gas phase) which have to be taken into account for the description of the combustion process. The model is part of an overall simulation program for circulating fluidized bed boilers. This engineering simulator has been developed to return the main performance parameters of such systems like temperature along the furnace height, size distribution of balanced solid components, heat flows at the different heat ...
A phenomenological model of the heat transfer in direct injection diesel engines was developed. Utilizing the thermodynamic results of a combustion model as an input, the model is able to predict the temporal variation of the heat losses from the cylinder gas to the cylinder walls. Additionally, the division into isothermal combustion chamber subsurfaces allows the consideration of the spatial variation of the wall heat fluxes. The physical mechanisms such as flow dependent convection, heat radiation due to hot soot particles and isolation effects of deposited soot layers are described in detail. Thus the effects of these mechanisms on the overall heat transfer can be studied. The heat transfer model was verified successfully by the comparison to measured wall heat fluxes in a single-cylinder direct injection diesel engine. It is shown that the effects of engine speed and load, turbocharging and soot deposition can be predicted with good accuracy. [German] Es wurde ein ...
The position paper will provide the basis for further strategies on offshore wind power development in consideration of ecological and conservation aspects. [German] Das Positionspapier des Bundesministeriums fuer Umwelt, Naturschutz und Reaktorsicherheit (BMU) einschliesslich des Umweltbundesamtes (UBA) und des Bundesamtes fuer Naturschutz (BfN) ist Ergebnis der Arbeiten der BMU-Projektgruppe 'Windenergienutzung im Offshore-Bereich im Hinblick auf die BMU-Anliegen'. Es beschreibt den derzeitigen Stand einer Strategie zur umwelt- und naturvertraeglichen Erschliessung der Windenergienutzung auf See (Offshore). Es bildet die Grundlage fuer die Weiterentwicklung dieser Strategie und dabei insbesondere zur Abstimmung mit den Anliegen anderer Bundesressorts und den Kuestenlaendern, sowie zur intensiveren Einbeziehung beteiligter Verbaende und Fachkreise. Vor dem Hintergrund der zur Genehmigung eingereichten Antraege fuer Offshore-Windparks, mangelnder Erfahrung der ...
More than two and a half years of monitoring of a passive house school and day-care centre in Frankfurt a. M. show comfortable indoor climate and good air quality. The space heat consumption is low and shows savings of approximately 90 % as compared to average existing schools. Excellent performance was also achieved in terms of primary energy. The results of further analyses of the efficient ventilation system with heat recovery, the perimeter insulation as an alternative to floor slab insulation and the influence of the air change due to the entrance door are presented. (Abstract Copyright [2008], Wiley Periodicals, Inc.) [German] Ueber zweieinhalb Jahre Monitoring einer Passivhaus-Schule und Kindertagesstaette (KiTa) in Frankfurt a.M. zeigt behagliche raumklimatische Bedingungen bei guten Luftqualitaeten. Die Heizwaermeverbrauchswerte liegen wie erwartet niedrig und zeigen Einsparungen um 90 % gegenueber dem Durchschnitt im Bestand. Auch primaerenergetisch ...
As a partner in this project, Siemens Power Generation investigated the crack propagation characteristics of short cracks in CMSX4. This involved crack propagation tests under dynamic and static load, creep tests on samples of different geometries, and life calculations, with the following results: No typical short cracking behaviour was observed under dynamic loads. Short crack propagation at 950 C under static load is well described by the fracture mechanical parameter C* integral. Notched bar creep tests showed longer times to cracking for notched bars. [German] In dem Verbundprojekt hat Siemens Power Generation u.a. die Untersuchungen von Rissausbreitungsverhalten von Kurzenrissen in CMSX4 als Hauptaufgabe bekommen. Dabei wurden Rissausbreitungsversuche unter dynamischer und statischer Belastung, Kriechversuche an Proben verschiedener Geometrie und Lebensdauerberechnung durchgefuehrt. Die wesentlichen Ergenisse sind wie folgt kurz zusammengefasst. Bei ...
Buildings in the USA are commonly not perceived as energy efficient and sustainable. Considering this, it comes as a surprise that the LEED (Leadership in Energy and Environmental Design) certification system is leading the process to certify ''Green Buildings'' despite the broad range of certification systems in countries such as BREEAM in England, CASBEE in Japan, HQE in France, Green Star in Australia, and most recently DGNB in Germany. International companies are pursuing the LEED certification due to its worldwide applicability - over 20,000 buildings in 76 countries are currently registered. (Abstract Copyright [2009], Wiley Periodicals, Inc.) [German] Die USA sind nicht gerade fuer oekologisches und energieeffizientes Bauen bekannt. Umso erstaunlicher ist es, dass das LEED-Zertifizierungssystem (Leadership in Energy and Environmental Design) neben anderen landesspezifischen Systemen wie z. B. BREEAM in England, CASBEE in ...
In 1991/1992, VEAG decided to convert its 500 MW plants at Jaenschwalde and Boxberg to the latest state of technology. This even included the discharge of the cleaned flue gas through the existing cooling towers. The site of the flue gas desulphurization plant and also the existing cooling tower shells required routeing of the clean gas lines similar to the routes in the existing plants of RWE. The positive experience accrued with the pipework material `glass-fibre reinforced vinyl ester resin` has also led to the selection of this material here. The universally positive experience gained from existing clean gas lines via cooling towers by very different power station operators induced VEAG and its partners also to equip new construction operations in the new Federal states with this technology. (orig.) [Deutsch] In den Jahren 1991/1992 entschloss sich die VEAG, ihre 500-MW-Anlagen Jaenschwalde und Boxberg auf den neuesten Stand der Technik umzuruesten. Hierzu gehoerte auch die ...
The evaluation of possible manufacture-based defects in turbine shafts and housings for component serviceability relevance is of particular interest not only in post-manufacturing NDT but also in evaluation of NDT results obtained by in-service inspections of components with long service lives. The results discussed in the paper are summarized as follows: Most of the examined natural defects in the forgings and castings behave like cracks under the simulated operating conditions and hence may well be evaluated by fracture mechanical methods for their serviceability relevance determined by crack propagation under fatigue, creep and creep-fatigue stress. The empirical correlation of true defect size and US testing results (echo signal, echodynamics, attenuation) permits improved determination of true defect sizes in the turbine components. Care has to be taken to select the proper testing and evaluation methods in compliance with defect types. (orig./MM) [Deutsch] Die ...
In early March, 2000 a modern electron-beam welding facility for both series and one-off production of valves bodies (500 kg, up to 50 mm wall thickness) was commissioned at Josch Strahlschweisstechnik. Welding is performed under a fine vacuum. This permits not only the welding of components subject to acceptance inspection (HP0 approval), but also of special materials such as titanium, molybdenum, tungsten, Hastelloy and copper, and also their pairings. Products are developed and readied for production using modern 3D CAD software. A modern nine-axis control system makes it possible to produce sockets in pipe-on-pipe joints. (orig.) [German] Anfang Maerz 2000 wurde eine moderne Elektronenstrahlschweissanlage fuer die Herstellung von Armaturengehaeusen in Grossserien oder auch fuer Einzelfertigung (500 kg, bis 50 mm Wanddicke) bei der Josch Strahlschweisstechnik in Betrieb genommen. Die Schweissungen erfolgen im Feinvakuum. Somit koennen neben dem Schweissen abnahmepflichtiger Bauteile ...
Following the conventional X-ray diagnosis of the skull and upper cervical spine, CT proved to be the primary diagnostic method after a skull and brain injury: For all 4 cases we succeeded in detecting the occipital condyle fracture and in determing its size and location by reconstructions (coronal, sagittal, 3-D). In the case of complex occompanying injuries like soft tissue hematomas (cerebral, in the spinal cord, and the soft tissue of the neck) or for the detection of brain stem contusion, MRT had significant advantages. MRT can offer a higher image quality in soft tissue, especially in the spinal cord and the brain. (orig.) [Deutsch] Im Anschluss an die konventionelle Roentgendiagnostik des Schaedels und der Halswirbelsaeule, erwies sich die Computertomographie als primaer einzusetzendes diagnostisches Verfahren, nach erlittenem Schaedel-Hirn-Trauma. In allen Faellen gelang der exakte Frakturnachweis an den Okzipitalkondylen, die Bestimmung des Frakturausmasses und die genaue ...
Experiments for lifetime prediction of the first wall are being carried out within the framework of the European fusion reactor programme. Defects such as notches and cavities may develop in the first wall and may initiate under cyclic thermal stress cracking processes which may reduce the service life of the material. For examination of crack growth, specimens with defined initial notches were prepared and subjected to cyclic thermal loads. The paper shows that the eddy current method is suitable for detecting and revealing the crack growth processes even under conditions of complex geometry, as e.g. cracks in inner bores. The experiments indicated particularly susceptible, critical spots in the first wall and yielded crack growth rates of use for lifetime calculations. (orig./CB) [Deutsch] Im Rahmen des europaeischen Fusionsreaktorprogramms werden Untersuchungen zur Lebensdauervorhersage der Ersten-Wand durchgefuehrt. Die Erste-Wand kann Fehler in Form von Lunkern und Kerben ...
Nuclear medicine and magnetic resonance imaging (MRI) are widely used in cardiac diagnostics. Both techniques have been carefully evaluated and are equivalent for the assessment of regional and global wall motion as well as the evaluation of ejection fraction and cardiac volumes, though MRI is herein currently seen as gold standard. For evaluation of myocardial perfusion, extensive data exist for nuclear imaging, that, next to high diagnostic accuracy for evaluation of coronary artery disease, show incremental prognostic information and allow for independent risk stratification. Because of rapid technical advance, myocardial perfusion imaging has also become feasible with cardiac MRI. Results of recent studies are promising, but the data are few compared to perfusion scintigraphy. For viability assessment in patients with ischemic cardiomyopathy, positron emission tomography (PET) with FDG is currently seen as gold standard. However, single photon emission computed tomography (SPECT) ...
The thermochemical calculations performed with a large number of elements to describe the chemical system in a Phebus FP test allow the following conclusions: The metallic absorber materials play a significant role in fission product speciation. At around 1000 C and above, silver iodide is the dominant iodine carrier in a full steam atmosphere in both FPT0 and FPT1. At lower temperatures, cadmium iodide takes over. In a reduced environment, indium iodide becomes important. Caesium iodide does certainly appear; at certain test conditions it becomes the major iodine transporting vehicle. But its role is not greater than that of the other iodides. It has more chances in FPT1 than in FPT0. Chlorine, which was present in FPT0 as a contaminant in relatively large amounts, does not prevent the iodine from forming Csl. Both share the caesium like partners. The evolution of caesium chloride and iodide proceeds in parallel. When CsCl is abundant, Csl is strong, too. Should boron be added to the ...
Tumours lesions of the temporal bone and of the cerebello-pontine angle are rare.This tumours can be separated into benign and malignant lesions. In this paper the CT and MRI characteristica of tumours of the temporal bone and the cerebello-pontane angle will be demonstrated. High resolution CT (HRCT) as usually performed in the axial plane are using a high resolution bone window level setting, coronal planes are the reconstructed from the axial data set or will be obtained directly. With the MRI FLAIR sequence in the axial plane the whole brain will be scanned either to depict or exclude a tumour invasion into the brain. After this,T2-weighted fast spin echo sequences or fatsuppressed inversion recovery sequences in high resolution technique in the axial plane will be obtained from the temporal bone and axial T1-weighted spinecho sequences before and after the intravenous application of contrast material will be obtained of this region. Finally T1-weighted spinecho sequences in high ...
The transport-relevant basic data recorded within the framework of a federation-wide transport data survey made in 1986 are the best-founded source at present for determining the transport volume of other radioactive materials in different economic areas of the Federal Republic of Germany. Due to the high recording rates, a sufficiently complete survey can be provided in particular with regard to the transport volume (e.g.transports/consignments/cargos, transport distance) - with the exception of transport by ship - for the ranges of application in reserach, medicine and technology. However, as regards the radiologically relevant basic data and transport modalities, the information supplied by the transporting agencies is incomplete. A table gives a comprehensive survey of type and scope of the transport volume of other radioactive materials in the Federal Republic of Germany (excluding the GDR) for transport by road, rail and air. The table also includes data on the dose rate of ...
This feasibility study of the uve Institut fuer Technische Chemie und Umweltschutz GmbH discusses the scientific and technical fundamentals of a catalytic process for complete removal of organic pollutants (PAH, H-HC, PCB, phenols, nitro-aromatics and organometallic compounds, e.g. from polluted soil and groundwater) by thermal-catalytic cracking and conversion into simple gases. The process is based on the catalytic reaction of the hydrocarbon compounds with water vapour in the temperature range of 700-900 degrees centigrade. The resulting gas mixtures consist mainly of hydrogen, carbon monoxide, carbon dioxide and methane which can be used as fuels, e.g. for heating or in gas engines. The process is an alterntive to combustion. It is therefore well suited whenever the pollutant to be removed is already mixed with water or water vapour and wherever in-situ removal would be too great a hazard. [Deutsch] Die vorliegende Machbarkeitsstudie aus dem uve Institut fuer Technische Chemie und ...
The ECOTEC is a mass-efficient gasoline DOHC 4-valve per cylinder engine with balance shafts, chain driven camshafts and roller finger followers with hydraulic lash adjusters for valve actuation. It has lightweight aluminium components such as camcover, cylinder head, cylinder block, lower crankcase and structural oil pan. Other features include composite intake manifold and a coil-on-plug ignition cassette. The ECOTEC combustion system and engine architecture are optimized for low engine out and tail pipe emissions. It also includes several designed-in 'green' features for environmental benefits. The product design, development and validation process drew upon the best knowledge and practices available worldwide both inside and outside General Motor. The manufacturing systems were also designed by leveraging the best available knowledge around the world resulting in implementation of world class processes and error proofing to achieve the competitive edge in product ...
The European Court of Justice has defined a clear means by which waste utilisation methods can be distinguished from waste disposal methods in a logical, well-understandable manner. With its stringent definition of ''utilisation'' this judgement points the way to quality-oriented waste management practices. We do not share the often voiced fear that this decision will lead to an increased incineration of compound wastes in industrial plants such as cement works. From the fact that, according to the decision by the European Court of Justice, wastes destined for utilisation fulfil a certain purpose and therefore, if not available in sufficient quantity must be replaced by primary raw materials, it follows that these wastes are required to fulfil specific quality criteria. This is rarely the case, if at all, with compound wastes. From the viewpoint of Luxembourg the decision by the European Court of Justice can be regarded as a positive impulse towards ...
Normally, the alloy NiMo28 is used in the solution annealed and quenched condition in which it has a face centred cubic matrix structure. The matrix of the material is supersaturated with molybdenum and, at temperatures above 800 C, has a tendency to form intermetallic precipitates such as the Ni{sub 4}Mo-ordered phase leading to the embrittlement of the NiMo28-ordered phase leading to the embrittlement of the NiMo28 alloy during hot working. For this reason, the aim of these investigations was to optimise the alloy by reducing its tendency to embrittle. The TEM-analyses carried out served to investigate the precipitation of the material as a function of its iron content after ageing at 700 C. The change in hardness and in the lattice constants of the NiMo28-specimens with iron content were also determined. To improve the hot working properties of this material it is recommended that the iron content be kept to about 3.2 mass % in order to reduce the tendency of the alloy to ...
To study the biogeochemical behaviour, mobility and transport of trace metals in seawater (Se, Mo, Cd, Pb, Hg, Cu, Co, Fe, Ni, Zn), in suspended particulate matter (Mo, Cd, Pb, Cu, Co, Fe, Ni, Zn, Al, Mn) and in sediments of the inner and outer coastal regions, samples were collected on 3 separate cruises during a one year period (Mai 1993 - April 1994) at 20 stations in the coastal area of Mecklenburg-Vorpommern. Standard hydrographic parameters, nutrients and dissolved oxygen were also measured. Priority was taken to establish the methods for the determination of molybdenum and selenium. To study the behaviour of these two elements in detail, longterm measurements were carried out weekly between January 1993 and June 1994 at the `Messsteg/Warnemuende`. Because of parallel measurements correlations to biological, chemical and hydrographic parameters have been tested. The total database is summarized in the Appendix. The results are presented in 30 figures and 13 tables and are ...
During their life, intervertebral discs undergo degenerative changes which need not necessarily become lesions. Conventional X-rays do not provide information on the condition of the intervertebral discs, so MRT or CT are recommended as primary techniques as they are non-invasive. Invasive methods like myelography and especially discography should not be used unless a case is highly problematic. In infants with pains in the back, MRT should be carried out as early as possible as there is nearly always an organic cause. (orig.) [German] Die Bandscheibe ist im Laufe des Lebens degenerativen Veraenderungen unterworfen, die klinisch zu Beschwerden fuehren koennen, aber nicht fuehren muessen. Konventionlle Roentgenaufnahmen lassen zwar die Hoehenminderung des Bandscheibenfachs und begleitende knoecherne Veraenderungen erkennen, nicht aber den Zustand der Bandscheibe selbst. Die Beurteilung der Bandscheibe und des Knochens gelingt mit der CT, die parallel zum Bandscheibenfach durchgefuehrt ...
Primary malignant lymphoma of the brain is a disease of unknown etiology, which is increasing in incidence and has an unfavorable prognosis. Despite the lack of specific changes on CT or MRI in most cases, these procedures may typically facilitate the diagnosis: A focal-enhancing mass with subependymal spread on CT or MRI and hyperattenuation on nonenhanced CT are the most reliable features in the diagnosis of primary malignant lymphoma of the brain. Peritumoral edema and mass effect are usually not prominent features. On unenhanced CT scans they usually appear homogeneously isodense to mildly hyperdense relative to the gray matter. On MRI these tumors are slightly hypointense on T1-weighted images and slightly hpyerintense on PD- and T2-weighted images relative to the gray matter. On CT and MRI enhancement is usually homogeneous. Contrast-enhanced MRI, with its multiplanar capability, lack of bone-induced artifacts, and high-contrast resolution, is likely to reveal subependymal spread ...
Magnetic resonance imaging (MRI) of the lung is challenging because of substantial drawbacks. However, lung pathologies that are associated with increased attenuation values in CT enhance visualization in MRI: proton density is increased and tissue-air interfaces, resulting in susceptibility artifacts, are reduced in pneumonia, pneumonitis, edema, and carcinoma. On the other hand, many lung diseases result in shortness of breath, so that patients cannot hold their breath for long periods. Therefore, fast imaging techniques are required which should also allow for high spatial resolution so that small lesions can be detected. Calcifications and air pockets within lesions are not readily recognized with MRI. Thin section CT is standard for the diagnosis of pneumonia. With parallel imaging techniques, MRI examination of the lungs can be performed with short periods of breath holding, which allow for sub-centimeter resolution in the z-axis. Especially for follow-up examinations in ...
60 patients between 17 and 72 years of age were investigated. First, an enteroclysis was performed in typical manner. The applicated methylcellulosis was blended with positive oral MR contrast media (Magnevist oral, Schering). After enteroclysis, MRI of the abdomen was performed using T1- and T2-weighted breathhold sequences (Flash 2D pre- and postcontrast and TSE) in axial and coronal planes. The length of the affected bowel and the stenosis seen with enteroclysis correlated well with the visible thickening of the small bowel wall and the stenosis seen in MRI. Using MRI, additional findings could be obtained in 28 patients, such as fistulas, abscesses or a hydronephrosis, or a better assessment of the stenosis was possible with MRI, because of the avoidance of overshadowing of the affected bowel loop with MRI. A brilliant MR-tomographic imaging of the small bowel is possible under the condition, that the small bowel contrast is optimal. The main prerequisite is a large filling volume ...
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 ...
The first commercial vehicle, built by Gottlieb Daimler in Cannstatt (Germany), head foto, had been the begin of a new transport technology around the world. Benz had been consolidated 1926 with Daimler to the Daimler-Benz AG with a new vehicle programme; all trucks over 5 t payload would be powered since 1935 by diesel engines only. Worldwide all-wheel drived vehicles had been under development for different purposes. After 1945 the European Automobil industry launched at first former types followed by new designed and improved types. The eight-wheeler used since the twentees in England conquered Switzerland, and in 1984 Germany too. The development of gear boxes and drive axles had been influenced on the drive train demands depending of the engine output and speed and the increased GTW. The future of the commercial vehicles will be determined by the European legislation, higher economy and reduced-pollutant Euro II and later Euro III engines, further by the cooperation of the truck ...
Surface structure analysis, i.e. metallographic analysis of component surfaces with the aid of replicas, is an established method of component monitoring and the only reliable non-destructive method for detecting and analyzing beginning creep damage in the form of creep pores. Creep pore development provides a basis for component condition analysis. It must be noted, however, that the modern martensitic 9-12 % Cr steels - like the established steels 10CrMo9-10 (P22) und X20CrMoV12-1 - have comparatively high creep fracture deformation rates in fatigue tests. This raises the question if these steels can be judged on the basis of data for established steels. The results so far suggest that even with low pore densities (single pores), a higher degree of damage and a shorter time until failure must be assumed. [German] Eine bewaehrte Methode der Bauteilueberwachung stellt die Oberflaechengefuegeuntersuchung, d. h. die metallografische Untersuchung der Bauteiloberflaeche mit Hilfe von ...
Low-cost titanium alloy components are getting increasing attention in aerospace applications. Cost reductions are possible in the alloys themselves and in the production techniques. The former aspect is less promising as titanium alloys are costly to produce. Of course, there are some new developments like the (alpha plus beta) alloy Ti-6 Al-2 Fe-0.2 Si (TIMETAL 62S) and the beta-alloy Ti-6.8 Mo-4.5 Fe-1.5 Al (TIMETAL LCB), in which low-cost iron replaces costly beta alloying elements like vanadium or molybdenum, but these will be used mainly on the mass production markets, e.g. motor car construction. In consequence, optimisation of production methods is the more promising option. Near net shape processes will reduce the production cost and improve the fly-to-buy ratio. Some of these production processes are explained. [Deutsch] Die Herstellung preiswerter Bauteile aus Titanlegierungen gewinnt auch in der Luft- und Raumfahrt zunehmend an Bedeutung. Zwei Wege werden hier beschritten: ...
FLUTAN is a highly vectorized computer code for 3D fluiddynamic and thermal-hydraulic analyses in Cartesian or cylinder coordinates. It is related to the family of COMMIX codes originally developed at Argonne National Laboratory, USA, and particularly to COMMIX-1A and COMMIX-1B, which were made available to FZK in the frame of cooperation contracts within the fast reactor safety field. FLUTAN 2.0 is an improved version of the FLUTAN code released in 1992. It offers some additional innovations, e.g. the QUICK-LECUSSO-FRAM techniques for reducing numerical diffusion in the k-{epsilon} turbulence model equations; a higher sophisticated wall model for specifying a mass flow outside the surface walls together with its flow path and its associated inlet and outlet flow temperatures; and a revised and upgraded pressure boundary condition to fully include the outlet cells in the solution process of the conservation equations. Last but not least, a so-called visualization option based on VISART ...
A new generation of lead alloys for making lead batteries is being introduced in highly developed countries. A very important characteristic of these alloys is the presence of Ca, Al and Sn. Such alloys have the property of stabilizing the amount of gas emitted as a result of the decomposition of the electrolyte on the level of pure lead i.e. significantly smaller than lead alloys containing Se e.g. PbSb 1.7Se. Such alloys have not been produced in Poland so far. - In this paper we are presenting the method and equipment used to produce a pilot portion of PbSnCaAl alloy (mass approximately 80 Mg) on an industrial scale at HMN ''Szopienice'' S.A. lead refinery. We also present the results of the tests regarding the chemical homogeneity of the alloy produced, as well as its structural and casting properties. On the basis of the tests conducted it has been found that the method is industrially adequate and as such it has been introduced into the ...
The aim of the presented investigation was to gain information about the behaviour of the initiation and growth of intercrystalline creep cracks during creep deformation from the evaluation of metallographic micrographs. The austenitic steel X10 NiCrAlTi 32 20 HT (Alloy 800 HT) was investigated by carrying out creep tests at 800 and 900 C with different nominal stresses until fracture. Additional tests are carried out on certain creep strains in the late tertiary creep stage. The creep tests are followed by a metallographic investigation of the crept specimens. The statistical distribution of the microcrack lengths was used to estimate the rate of crack initiation and crack growth. It is found that the rate of growth of the intercrystalline creep cracks in Alloy 800 HT is dependent on the applied stress and the creep strain reached. The rate of growth of long cracks was only slightly higher than that of short cracks and was lower than predictions based on fracture mechanics concepts. ...
Maintenance of power stations so far operated on the concept of using or extending the expected service life of a machine or plant as far as possible in order to avoid early and costly replacement. This was done by means of time-oriented maintenance, inspection and repair, otherwise called preventive maintenance. A European study on maintenance methods totals the cost of these measures at between 140 to 200 billion DM. One way of reducing these costs is 'predictive maintenance'. Estimated savings are about 8 percent or between 12 and 16 billion DM per year. Predictive maintenance identifies irregulaties of machine parts at an early point in time by means of condition monitoring and can help to cut costs: unplanned repairs can be avoided; repairs can be fitted into production schedules; production will not be disturbed to to unforeseen repairs, optimised spare part warehousing helps to cut costs. Predictive maintenance aims at keeping availability high, give maximum ...
CT-Expo is a novel MS Excel application for assessing the radiation doses delivered to patients undergoing CT examinations, based on computational methods that were used to analyze the data collected in the German survey on CT practice in 1999. The program enables the calculation of all dose quantities of practical value, such as axial dose free-in-air, weighted CTDI, dose-length product, effective dose and uterine dose. In contrast to existing programs for CT dose assessment, CT-Expo offers a number of unique features, such as gender-specific dose calculation for all age groups (adults, children, newborns), applicability to all existing scanner models including correction of scanner-specific influences, and the possibility of comparison with the results from the German CT survey on CT practice. Three different application modules offer free and standardized dose calculations as well as a comprehensive benchmarking section including guidance on dose optimization. The program is ...
Purpose: `Exoscopic` and endoscopic identification of colorectal pathologies via MRI. Methods: 5 patients (36-88 years), two normal and three with different colorectal pathologies (diverticular disease, polyps and carcinoma of the colon), were examined by MRI after colonoscopy. Subsequent to filling of the colon with a gadolinium-water mixture under MRI-monitoring, 3D-data sets of the colon were acquired in prone and supine positions over a 28 sec breathold interval. Subsequently multiplanar T{sub 1}-weighted 2D-sequences were acquired before and following i.v. administration of Gd-DTPA (0.1 mmol/kg BW). All imaging was performed in the coronal orientation. The 3D-data were interactively analysed based on various displays: Maximum intensity projection (MIP), surface shadowed display (SSD), multiplanar reconstruction (MPR), virtual colonoscopy (VC). Results: All of the colorectal pathologies could be interactively diagnosed by MPR. On MIP images some pathologies were missed. VC ...
Storing electrical energy in batteries is not a viable option for sustaining a country's energy economy. The mass and volume, as well as the costs, of electrochemical components required for this would be beyond all reason. Nevertheless, in certain applications the storage of electrical energy does have significant advantages over other technologies. For example, electrically powered road vehicles emit no exhaust fumes and very little noise at their place of operation. In this way they contribute substantially to air and noise pollution control in urban areas. Photovoltaic applications permit environmentally friendly electricity applications in places remote from the public grid where conventional solutions are prohibitively expensive. More than in the past, battery systems today have to meet a wide range of technical, economic and ecological requirements in order to be marketable. This is why the ''Zoxy'' zinc-air battery system was ...
In the future even more than in the past, nuclear power will be indispensable in the present industrialized countries and in those still under development. The safe, nonpolluting, and economic supply of energy to mankind in the future includes so many different problems that the technology of the high-temperature reactor at its present level of development, and with the possibilities is offers above and beyond those provided by other, established, technologies, does not have to mark the end of some old line of development, but rather should be seen as the starting point of a development offering promise for the future. It is for this very reason that the extensive, valuable knowledge and experience accumulated in the construction, operation, and decommissioning of the AVR and THTR plants, the development of the HTR module and other variants and, last, but not least, the valuable results of projects such as PNP, NFE, and HHT, must be preserved at the research centers and with former ...
The staging of patients with multiple myeloma demands sensitive imaging methods for the assessment of the skeletal system. MRI allows for direct visualization of the bone marrow which exhibits five different infiltration patterns in multiple myeloma: 1. normal appearance of the bone marrow, 2. focal involvement, 3. homogeneous diffuse infiltration, 4. combined diffuse and focal infiltration, 5. ''salt and pepper'' pattern with inhomogeneous bone marrow signals due to multiple fat islands. The combination of T1w-SE and STIR sequences is best suited for detecting all infiltration patterns and for the differential diagnoses e. g. hemangiomas. With parallel imaging in MRI, acquisition times can be markedly reduced and whole-body screening of the bone marrow can be achieved within 30 min. MRI is superior to radiography for the detection of focal as well as diffuse infiltration. Multidetector computed tomography and especially 16- and 64-detector row ...
From autumn this year, the FRJ-2 of the Research Center Juelich will be supplying molybdenum targets to the Institut National des Radioelements in Fleurus, Belgium - which deals in medical radio-isotopes worldwide - thus helping to meet the need for technetium-99, which is used in the medical profession for diagnostic purposes because of its favourable radiological characteristics. Technetium-99 is formed as a result of the radioactive decay of molybdenum-99. For many years now, molybdenum has been produced by the irradiation of uranium in research reactors, so that the initiation of molybdenum production in the FRJ-2 is not especially new. What is unusual, however, are the particular peripheral conditions which result from the combination of the irradiation requirements, a predetermined target design and the technical characteristics of the reactor and which necessitated special solutions. This applies especially to the handling of the targets after irradiation, which is much more ...
The further optimisation and improvement of the efficiency of internal combustion engines require the realisation of new technologies leading to a distinctively faster warm-up behaviour of the coolant and lubricants as well as of the engine components after a cold start. In order to achieve reduced fuel consumption and exhaust gas emissions with the help of heat management, the design criteria of innovative cooling systems need to be reflected and adapted to future requirements. The use of intelligent components within the cooling system, such as the 'Stand Alone Rotary Valve' as a thermostat's substitute or the use of coolant pumps with a rotary valve integrated into the pump's inlet chamber, offer new ways to realise in a decisively quicker and more flexible way the appropriate heating up and cooling down procedures at varying driving conditions. A description of both of the intelligent components for the cooling system is given in this paper. The ...
Which imaging modalities are appropriate for the Differential diagnosis of Rheumatic diseases. MRI has far most the highest sensitivity and is unequaled in its brilliant presentation of Anatomy and Pathology. But it is sometimes forgotten, that this is at least in part the result of carefully selected sequences, dedicated to the expected result. In a method totally independent of any result, this should not be the case. In contrary this method should be highly standardised and regardless what will be the findings. This is true for Plain X-ray. It will be shown, that already the outer silhouette of the soft parts with different features of swelling, and differences in density and even more - defects or appositions of the bony silhouette in the majority of cases at least will allow to classify the patient for a group of diseases and in many cases will lead to a definite diagnosis. Differential diagnoses like Rheumatoid Arthritis versus Psoriatic Arthritis or simply but not always simple ...
A cooperative effort of the Center for Solar Energy and Hydrogen Research (ZSW) and Phototronics Solartechnik GmbH (PST) aimed at the transfer of highly efficient solar cells developed on a laboratory scale, to large-area thin-film solar modules suitable for production. This work was based on research and development at the Institute for Physical Electronics (IPE) of Stuttgart University and ZSW on one hand, and on the know-how of PST in regard to large-area module fabrication on the other hand. The various thin-film layers of the cells and modules comprize molybdenum as rear contact, copper-indium(gallium)-diselenide (CIGS) as absorber material, the combination of cadmium sulphide (CdS) and ZnO as window layer. To produce these layers on large areas (30x30 cm{sup 2}), equipment was constructed and procedures were developed. Monolithic series connection of cells, used in other thin-film technologies, was studied and optimized by suitable patterning procedures, such as laser-scribing, ...
1. In order to carry out isothermic crystal growth experiments of YBCO the 123 primary crystallization field was determined by means of phase diagram investigations and crystal growth experiments at different oxygen partial pressure. 2. YBCO single crystals of high crystallographic perfection were grown and conclusions on the flux pinning mechanism were drawn. 3. By means of Liquid Phase Epitaxy (LPE) single crystalline (Tc{approx}90 K; {Delta}T{<=}0.5 K) c- and a,b- YBCO fils have been prepared on NdGaO{sub 3} and LaGaO{sub 3} substrates. The films were characterized structurally and magnetically. 4. Our fist melt textured YBCO ``single crystals`` possess intracrystalline critical current densities >10{sup 4} A/cm{sup 2} at B{<=}2T. The irreversibility inductions are {<=}6 T at 77 K. A simple demonstrator was constructed together with the IFW Dresden and a growth model was developed. 5. Using above all torque magnetometer measurements we separated intrinsic pinning effects ...
Purpose: For planning the therapeutic strategies and estimating the prognosis in esophageal cancer, N-staging is very important. To date, MRI still is of minor importance as imaging modality of the mediastinum despite promising developments in the past, like ECG-gating or 'averaging' sequences, e.g. LOTA (Long-term averaging), which facilitate mediastinal and thoracic MR-imaging. In a prospective approach, the value of MRI based N-staging was examined with respect to LOTA-sequences. Material and Methods: Within from weeks prior to esophagectomy, standardized MRI of the esophagus was performed in 15 patients (10 squamous-cell-carcinomas and 5 adenocarcinomas) using a 1.5 T whole body scanner. Imaging quality was classified based on depiction of aortic wall or tracheal wall layers. Criteria for malignant infiltration were a diameter of more than 15 mm or a round appearance of a lymph node together with GD-DTPA enhancement. All data were blinded and separately read by ...
Aim: Today, MRI is an integral part of the presurgical evaluation of patients suffering from partial epilepsy. These patients frequently show focal morphological abnormalities with potential epileptogenic character and surgical resection of these lesions is associated with superior postsurgical outcome as to seizure frequency. Apart from easily detectable defects, such as post-traumatic lesions or cerebral infarction, as wide variety of mainly small abnormalities can be detected using MRI. Methods: In this study, 484 patients suffering from partial epilepsy of temporal or frontal onset were evaluated for the incidence of different lesions in this population. Results: All lesions found were included without evaluating their potential epileptogenicity, which remains to be proven using other procedures (EEG, SPECT, PET, etc.). Involvement of the hippocampal formation was a major finding in temporal lobe epilepsy, which could be detected as sclerosis (T2w-images), atrophy (T2w-TSE or ...
We report for the first time about a micromachined mass flow sensor directly integrated between the double guidance and the needle seat into the body of a Common Rail (CR) injection nozzle. The thermal measurement principle was chosen because gaseous as well as liquid mass flows can be determined fast and precisely. Additionally, with glass-ceramic materials fabricated in a low cost batch process, a high temperature and especially pressure stable substrate can be used. The flow sensitive thin film is realized by an e-beam evaporated 110 nm thick molybdenum (Mo) layer. The latter is electrically characterized by the resistivity of {rho} = 8.2 x 10{sup -7} {omega} m ({+-}2%) at room temperature as well as by the first {alpha}=4.5 x 10{sup -4} K{sup -1} ({+-}5%) and second {beta}=3.0 x 10{sup -6} K{sup -2} ({+-}12%) temperature coefficients of resistance up to 300 C. The static temperature field at and around the thin film sensor on the glass-ceramic substrate is investigated with an IR ...
Low energy buildings promise significant energy savings and help climate preservation by cutting down on annual heating requirements to values below 70 kWh per m{sup 2} dwelling space. It is expected that low energy constructions will become the common standard by the year 2000 as a result of the forthcoming energy saving ordinance. For making the introduction and implementation of this standard successful, practical experience will be essential. For this reason, the state government of Hesse has supported respective pilot projects 1987. In 1989 the funding programme `30 low energy buildings in Hesse` has been established. Consecutively - between 1989 and 1993 - 29 buildings were erected. At first, the thermal quality of the crafted building construction including the ventilation systems was checked. Consecutively, energy consumption, indoor and outdoor temperatures were measured over a time span of several years. The experience of the inhabitants was surveyed. The `Institut Wohnen und ...
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