WorldWideScience
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Verlauf des lokoregionären Prostatakarzinoms unter Diätveränderung und Nahrungsmittelergänzung: Longitudinale Beobachtung über mehr als 3 Jahre  

Directory of Open Access Journals (Sweden)

Full Text Available Einleitung: Auftreten und Verlauf des lokal begrenzten Prostatakarzinoms wird durch Diätveränderungen beeinflußt. Wir haben untersucht, ob durch Veränderung der Diätgewohnheiten und Substitution von Nahrungsergänzungsmittel (Active Surveillance der klinische Verlauf des Karzinoms beeinflußt oder eine radikale Behandlung aufgeschoben oder gar vermieden werden kann. Material und Methode: Wir verfolgten den klinischen Verlauf und die PSA-Werte von 13 Patienten mit einem stanzbioptisch verifizierten organbegrenzten Prostatakarzinom. Allen Patienten mit einem T-Stadium 3 mit einem PSA 10 ng/ml und einem Gleasonscore 7 wurde eine Active Surveillance-Strategie mit zusätzlichen Diätempfehlungen und Nahrungsergänzungsmitteln anstelle einer radikalen Prostatektomie offeriert. Alle Patienten erhielten hierfür täglich als Nahrungsmittelergänzung eine Mischung an Radikalfängern (Karotinoide, Selen, Flavonoide, Vit. A, E und Phytoöstrogene. Alle Patienten wurden routinemäßig einmal pro Jahr mindestens 8-fach biopsiert. PSA-Werte und eine rektale Untersuchung wurde alle drei Monate durchgeführt. Eine radikale Prostatektomie wurde im Falle eines zweimaligen konsekutiven PSA-Anstieges und/oder eines suspekten Tastbefundes und/oder einer Ausdehnung der Anzahl positiver Stanzen bei wiederholten Biopsien durchgeführt. Resultate: Wir überschauen nun median 21 Monate (5?90 einer Active Surveillance-Strategie bei 13 Männern (medianes Alter: 65. Bei 3 Männern führte ein konsekutiver PSA-Anstieg zur Planung einer radikalen Prostatektomie (1 Patient verstarb vor der Operation an einer intrazerebralen Blutung, einer verweigerte den Eingriff. Beim verbliebenen Patienten führten wir 14 Monaten nach Diagnosestellung eine Schnittrand-negative Prostatektomie eines pT2c-Gleason-6-Tumors durch (PSA 0 ng/ml frei nach 11 Monaten Follow-up. Von allen Patienten, die initial maximal bis zu 2 positive Gewebsproben hatten, konnte bei 38 % in den Kontrollbiopsien kein Tumor mehr nachgewiesen werden, bei 46 % blieb die Anzahl der positiven Biopsien gleich. Keiner der Patienten ist bis jetzt klinisch apparent geworden. Konklusion: Eine diätetische Unterstützung (Active Surveillance kann den klinischen Verlauf des organbegrenzten Karzinoms günstig beeinflussen. Diese Therapieoption kann Patienten in Hinblick auf eine Lebensqualitätsorientierte Lebenserwartung auch von mehr als 10 Jahren angeboten werden. Voraussetzung ist ein strenger Follow-up und eine entsprechende Compliance.

Schlarp OM

2006-01-01

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Costs for heating and hot water more than halved; Kosten fuer Warmwasser und Heizung mehr als halbiert. Eine moderne Solaranlage deckt zwei Drittel des Energiebedarfs fuer die Warmwasserbereitung in einem Ferienhaus  

Energy Technology Data Exchange (ETDEWEB)

This article describes how solar technology provides three-quarters of the water-heating energy requirements of a Swiss chalet in Riederalp. Advances in solar heating technology and the reduction of prices over the past few years are discussed. The installation, which uses vacuum-tube collectors that are integrated into the balustrades of the south-facing balconies of the three-storey chalet with holiday apartments, is briefly described. The partial financial support provided by the local authorities is discussed as is the word-of-mouth propaganda triggered off in this mountain resort which has led to increased interest in the combination of solar energy and traditional heating forms.

Haag, J.

2005-07-01

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Hashimoto-Thyreoiditis: Mehr als nur Schilddrüsenhormonmangel?  

Directory of Open Access Journals (Sweden)

Full Text Available Eine Autoimmunthyreoiditis wird häufig mit einer Vielzahl von Beschwerden in Verbindung gebracht. Die Gründe hierfür sind vielgestaltig. Neue Erkenntnisse zum Wirkmechanismus von Schilddrüsenhormonen im zentralen Nervensystem stellen erstmals eine mögliche molekulare Erklärung für individuell unterschiedliche neurokognitive Manifestationen von Schilddrüsenfunktionsstörungen dar und könnten deshalb auch ein unterschiedliches Ansprechen auf eine Schilddrüsenhormonsubstitutionstherapie "trotz Euthyreose" bei Patienten mit Hashimoto- Thyreoiditis und anderen Ursachen einer Hypothyreose erklären.

Führer D

2010-01-01

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Musterbildung in Mehr-Komponenten-Membranen  

OpenAIRE

Biologische Membranen bestehen aus einer Vielzahl von verschiedenen Komponenten und dienen als selektive Barrieren, die das Innere von Zellen vor Einflüssen aus der Umgebung schützen. Als einfache Modelle dieser sehr komplexen Biomembranen dienen Multi-Komponenten-Membranen aus einer kleinen Anzahl von Lipidsorten. Da die Dicke von Lipidmembranen sehr klein ist im Vergleich zu ihrer Fläche, können wir sie als zweidimensionale Systeme behandeln, die sich in verschiedene thermodynamischen P...

Rouhiparkouhi, Tahereh

2013-01-01

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Headaches. More than just sinusitis; Kopfschmerzen. Mehr als nur Sinusitis  

Energy Technology Data Exchange (ETDEWEB)

Headaches are among the commonest somatic complaints seen in clinical practice. The International Headache Society differentiates about 190 types of headaches. This article focuses on the variety of secondary headaches with a radiologically identifiable cause. (orig.)

Knauth, Michael [Universitaetsklinikum Goettingen (Germany). Abt. Neuroradiologie

2011-09-15

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Use of fuel cells in multi-MW-thermal power plants; Brennstoffzelleneinsatz im Mehr-MW-Heizkraftwerk  

Energy Technology Data Exchange (ETDEWEB)

Natural gas fuel cells with phosphoric acid electrolyte today are already used in small series of compact units ranging up to 500 kW electric capacity. They thus represent a successful contribution to decentralised power production through cogeneration. Their use in multi-MW thermal power stations is technically possible and, in view of their low emissions and great efficiency, a very attractive alternative. This technology merits intensive development work in order to acquire through practical experience the know-how for bringing costs down to an acceptable level. Manufacturers and operators will need to prepare themselves for modifications regarding the operation and maintenance of these larger plants. The results of a feasibility study for a 1.5 MW thermal power plant presented in this article could come in useful here. (orig.) [Deutsch] Erdgasbetriebene Brennstoffzellen mit Phosphorsaeure-Elektrolyt werden heute bereits in Kleinserien als kompakte Einheiten mit einer elektrischen Leistung von bis zu 500 kW gebaut und mit Erfolg in der dezentralen Energieerzeugung auf Basis der Kraft-Waerme-Kopplung betrieben. Der Einsatz in Mehr-MW-Heizkraftwerken ist ebenfalls moeglich und sollte unter dem Aspekt einer schadstoffarmen und effizienten Energieerzeugung intensiv weiter verfolgt werden, um ueber die gewonnenen Erfahrungen die angestrebten Kostenziele zu erreichen. Technologiebedingt muessen sich Hersteller und Betreiber auf die veraenderten Anforderungen bezueglich Betrieb und Wartung rechtzeitig einstellen. Die nachfolgend vorgestellten Ergebnisse einer Machbarkeitsstudie fuer ein 1,5-MW-Heizkraftwerk koennen dabei hilfreich sein. (orig.)

Lezuo, A. [Siemens AG, Erlangen (Germany); Knappstein, H. [Thyssengas GmbH, Duisburg (Germany); Langnickel, U. [Gas-, Elektrizitaets- und Wasserwerke Koeln AG (GEW) (Germany); Nymoen, H. [Ruhrgas AG, Essen (Germany)

1995-09-01

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"Mehr als, bloss Bucher" Die Bibliothek Gellerup. Vom "Buchcontainer" zum Community Centre: Ein Beispiel aus Danemark.  

DEFF Research Database (Denmark)

Kapitlet handler om bibliotekets mulige rolle som facilitator af empowermentprocesser og social inklusion i marginaliserede byområder med Community Center Gellerup som eksempel. Bidraget indgår i en antologi baseret på et forskningsseminar på Humboldt-Universitat, Berlin om bibliotekers rolle for interkulturel dialog m.v.

Andersen, John; Frandsen, Martin

2008-01-01

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Hydrogen - more than just a mobile application; Wasserstoff - mehr als nur eine mobile Anwendung  

Energy Technology Data Exchange (ETDEWEB)

The securing of a reliable, economical and environmentally friendly energy supply is one of the greatest challenges of the 21st century. Using the energy concept, the Federal Government formulates guidelines for such an energy supply and describes for the first time the way for the age of renewable energy. It is all about the development and implementation of an overall long-term strategy for the time period up to 2050.

Pitschak, Bernd [Hydrogenics GmbH, Gladbeck (Germany)

2013-03-15

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More than only heat protection. Heat insulation composite systems; Mehr als nur Waermeschutz. Waermedaemmverbundsysteme  

Energy Technology Data Exchange (ETDEWEB)

Thermal energy composite systems are used in order to protect the outer walls of buildings against heat losses. The contribution under consideration reports on the advantages of such composite systems. Such a thermal energy composite system should be utilized only if it is certificated by the Centre of Competence in Civil Engineering (Berlin, Federal Republic of Germany). The single components of the thermal energy composite system as well as their processing are regulated in this certification.

Anon.

2012-07-01

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Mehr als eine politische Lehrstunde : V. Baltische Studenten-Seminar in Darmstadt  

Index Scriptorium Estoniae

16.-21. novembrini 2010 toimunud viienda balti üliõpilasseminari keskpunktis oli teemadekompleks demokraatiast Baltimaades. Arutleti ka demokraatiakogemuse üle kahel viimasel sajandil Saksamaal. Jugendherberges alanud seminar jätkus Darmstadtis ja lõppes Saksa-Balti Seltsi 60nda juubeli tähistamisega. Viie päeva temaatika haaras Baltimaade ja Euroopa kultuuri, poliitikat ja ajalugu

2010-01-01

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Utilization level utilizes more than the effectiveness; Nutzungsgrad nutzt mehr als Wirkungsgrad  

Energy Technology Data Exchange (ETDEWEB)

By virtue of a damage at the turbine gear of the hydroelectric power plant Luisenthal of the Thuringian distant water supply, a new turbine runner had to be provided in order to achieve a better adjustment of the turbine to the new operating details. The maximum efficiency was nearly constant in the redesign of the runner of the Francis turbine. The progress of the efficiency with the hydraulic performance shows a flat optimum resulting in a utilisation level of nearly 14% being relevant for the operator.

Mueller, Martin [Hochschule Ulm (Germany); Treiber, Gerd [TWA Wasserkraft-Anlagenbau GmbH, Ilmtal (Germany); Linz, Hans-Dieter [Thueringer Fernwasserversorgung (TFW), Erfurt (Germany)

2013-02-01

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A review on weaknesses and strengths of delivering Mehr housing project in terms of achieving economical goals  

OpenAIRE

Housing is one of the most important sections of development in a country and its economic importance has put it in the center of attention. It can cause rise and depression of habitation by its extended economic aspects. Mehr Housing plan is a state run housing project in most cities started 2007 in Iran to protect and provide cheap housing for poor people and young couples. Mehr housing project by its large scale and wide dimensions can affect the society’s economy. Therefore, to investig...

Ali Karshenasan; Mahsa Beiranvand

2013-01-01

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A review on weaknesses and strengths of delivering Mehr housing project in terms of achieving economical goals  

Directory of Open Access Journals (Sweden)

Full Text Available Housing is one of the most important sections of development in a country and its economic importance has put it in the center of attention. It can cause rise and depression of habitation by its extended economic aspects. Mehr Housing plan is a state run housing project in most cities started 2007 in Iran to protect and provide cheap housing for poor people and young couples. Mehr housing project by its large scale and wide dimensions can affect the society’s economy. Therefore, to investigate weaknesses and strengths of this project in terms of economic and applying necessary reformation can increase the success probability of this project. For this purpose, this study assess the weaknesses and strengths of Mehr housing of province of Khorram Abad in Iran for achieving economic goals and also presents solutions to better access to these goals. Time scope of the present study is 6 months of 2011 and the second 3 months of 2012. The methodology is applicable in terms of goal and is descriptive survey in terms of nature. In this study, a combined method of interviewing to experts and distributing a questionnaire among the applicants of Mehr housing has been used for data collecting. Among strengths of Khorram Abad in economic section, employment and urban landfill pattern reformation can be implied. In addition, among weaknesses of this project are lack of proper first design and technical justification of the project and use of only 2 shabby fabrics.

Ali Karshenasan

2013-09-01

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Soil Surface Attributes Prediction Using Digital Topographic Model in Mehr Catchment, Sabzevar, Khorasan Province  

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Full Text Available Conventional soil survey methods for soils within the watersheds in Iran require a significant budget with many soil surveyors and much time. Additionally, no accurate and reliable information exists on the spatial variability of superface soil parameters in order to predict the soil loss by different models (RUSLE, PISAC, EUPOSEM, MORGAN. Also information on planning and management activities is lacking. These limitations call for methods of estimating soil properties using minimum sampling derived from important terrain parameters. This study was performed to develop soil-landscape models in three geological units (E2Sc, Ku, Plc, in a part of Mehr- watershed, Sabzevar. Six soil variables selected for this study were topsoil clay, gravel, sand, organic matter content, field capacity and bulk density measured at 316 sites on a regular 100m grid. Topographic attributes were calculated by a digital elevation model with 100m spacing. Finally, multiple linear regression analyses relating soil to topographic attributes were performed and then models were validated by additional sample points (78 of 316. The developed regression models showed significant relationships between surface soil properties and topographic attributes such as elevation, slope, aspect, wetness index, stream power index and sediment transport index. The mean errors and root mean square errors in the validation of the models were low and acceptable. The regression equations could explain only 26 to 72 % of the variability measured in the soil attributes in the watershed scale with 100m spacing.

Sh. Ayobi

2006-07-01

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Qualitative Evaluation of Land Suitability for Extensive Grazing in Mehr Watershed, Sabzevar, Khorasan Province  

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Full Text Available Overgrazing is the most important agent which causes accelerated soil erosion and land degradation in arid and semi-arid zones of Iran. Appropriate planning and land use in these areas based on land suitability evaluation provide a suitable base for conserving the land and controling desertification. Land evaluation identifies possible alternatives in land use which will more effectively meet national or local needs and assists in assessing the consequences of these alternatives. Extensive grazing refers to the land utilization type in which animals feed in natural pastures. This study was performed to evaluate physical potential of the given watershed for grazing by sheep and goats, and assess the limiting factors for the land utilization type in Mehr watershed, Sabzevar, Khorasan province. Land qualities which were evaluated include accessibility to animals, soil erodibility, moisture availability, rooting conditions, salinity and alkalinity, and drinking water availability for animals. Above mentioned land qualities were assessed by appropriate land characteristics. The requirement of grazing land utilization type was defined in terms of rated land characteristics. Matching of requirements of LUT with the land qualities of each pixel of DEM (prepared in 200×200m by GIS software resulted in a rating for every land characteristics. Some characteristics such as slope, aspect, and distance to drinking water for animals were calculated directly by GIS. Land index for every pixel was calculated by square root method. Finally, qualitative and physical land suitability classes were determined based on land indices and classified to polygons which would be suitable in grazing management. The results were interpreted under two different scenarios. In the first scenario, drinking water for animals was supplied by permanent sources and in the second one, the supplying of water was developed to temporary rivers besides the permanent sources. With the analysis of spatial modeling it was possible to assess the land suitability with higher accuracy. Overall results showed that the given area was not highly suitable for grazing at all. The most limiting factors included moisture availability for plant growth, slope, rock fragment and outcrops and distance to drinking water. Also during the late winter, spring and early summer, when the seasonal rivers were supplying the drinking water, the limitation of given area was decreased.

Sh. Ayoubi

2006-10-01

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Adipositastherapie: Nahrung als Intervention  

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Full Text Available Die Behandlung der Adipositas bedarf einer umfassenden Therapie, wobei die Nahrung als Intervention nicht mehr ausschließlich auf Kalorienreduktion bezogen werden darf. Die ursprüngliche Bedeutung des Begriffes "Diät" im Sinne einer grundlegend vernünftigen Lebensführung muß neu bewertet und in eine lebendige Form der Gesundheitsvorsorge eingebunden werden. Mit einer differenzierten Diagnose der Adipositas kann mit verschiedenen ernährungstherapeutischen Ansätzen individuell geholfen werden. Die Sinnhaftigkeit von Formuladiäten, Diät- und Lightprodukten bedarf dringend einer fachspezifischen Information. Neben den entsprechenden Nährstoffempfehlungen hat ein Ernährungsprogramm aber auch der Durchführbarkeit und der Compliance der Patienten zu genügen. Damit soll dem "Risikofaktor Diät" entgegengesteuert und dem Hilfeschrei unserer Patienten Folge geleistet werden.

Wallner SJ

2001-01-01

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Heat recovery gain more than doubled. Heat recovery system controller; Rueckwaermezahl mehr als verdoppelt. WRG-Controller  

Energy Technology Data Exchange (ETDEWEB)

The hospital at Munich-Bogenhausen, which is a top level hospital with more than 1000 beds, modernised its heat recovery system first installed in the eighties of last century. A modern high-efficiency integrated recirculation system was installed instead. The system has a novel heat recovery controller which not only detects deviations from optimal operation but also identifies the causes. The system supplier, Konvekta AG of St.Gallen, Switzerland, is able to guarantee a heat recovery rate of 87 percent on a long-term basis. The energy cost for preheating of the ambient air was reduced by 78 percent as compared to the original system. (orig.)

Voit, Christian [Kulle und Hofstetter, TGA Consulting, Muenchen (Germany); Niederer, Martin [Konvekta AG, St. Gallen (Switzerland)

2009-03-15

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Der Glaube als Erkenntnisquelle  

Directory of Open Access Journals (Sweden)

Full Text Available Seit ihrer Kanonisation 1998 und Ernennung zur Mit-Patronin Europas 1999 steht die 1942 in Auschwitz ermordete Phänomenologin Edith Stein, 1922 vom jüdischen zum christlichen Glauben konvertiert und 1933 als Benedicta vom Kreuz in den Kölner Karmel eingetreten, mehr denn je im Blickfeld der Öffentlichkeit. Die Bedeutung ihrer wissenschaftlichen Arbeit u. a. als Assistentin von Edmund Husserl in Freiburg und als Dozentin am Deutschen Institut für wissenschaftliche Pädagogik in Münster, aber auch in privaten Studien wurden im Juli 2000 im Rahmen eines Symposiums des Internationalen Edith Stein Instituts in Würzburg diskutiert. Die Beiträge der vorliegenden Publikation beleuchten breit gefächert Aspekte des Werks und seiner Interpretation mit dem Ziel, die Philosophin neu zu entdecken und die bisherige Forschung zu intensivieren.

Andrea Hartwig

2004-03-01

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Computed tomography guidance. Fluoroscopy and more; CT-Steuerung. Fluoroskopie und mehr  

Energy Technology Data Exchange (ETDEWEB)

Although ultrasound and magnetic resonance imaging are competitive imaging modalities for the guidance of needle-based interventions, computed tomography (CT) is the only modality suitable for image-guided interventions in all regions of the body, including the lungs and bone. The ongoing technical development of CT involves accelerated image acquisition, significantly improved spatial resolution, CT scanners with an extended gantry diameter, acceleration of the procedure through joystick control of relevant functions of interventional CT by the interventional radiologist and tube current modulation to protect the hands of the examiner and radiosensitive organs of the patient. CT fluoroscopy can be used as a real-time method (the intervention is monitored under continuous CT fluoroscopy) or as a quick check method (repeated acquisitions of individual CT fluoroscopic images after each change of needle or table position). For the two approaches, multislice CT fluoroscopy (MSCTF) technique with wide detectors is particularly useful because even in the case of needle deviation from the center slice the needle tip is simultaneously visualised in the neighboring slices. With the aid of this technique a precise placement of interventional devices is possible even in angled access routes and in the presence of pronounced respiratory organ movements. As the reduction of CT fluoroscopy time significantly reduces radiation exposure for the patient and staff, the combination of a quick check technique and a low milliampere technique with multislice CT fluoroscopy devices is advantageous. (orig.) [German] Obwohl sonographisch und magnetresonanztomographisch gesteuerte Interventionen ernstzunehmende Konkurrenzverfahren sind, kann die Computertomographie als einzige bildgebende Modalitaet zur Steuerung von Interventionen in allen Koerperregionen (einschliesslich Lunge und Knochen) eingesetzt werden. Die technischen Weiterentwicklungen der Computertomographie beinhalten eine beschleunigte Bildakquisition, eine deutlich verbesserte raeumliche Aufloesung, CT-Scanner mit erweiterter Gantryoeffnung, eine Beschleunigung des Eingriffs durch eine intrainterventionelle Steuerung wesentlicher Funktionen des Interventions-CT ueber eine spezielle Bedieneinheit durch den interventionellen Radiologen selbst sowie die Angular Beam Modulation zur Schonung der Hand des Untersuchers und strahlensensibler Organe des Patienten. Die CT-Fluoroskopie (CTF) kann als Echtzeitverfahren (die Intervention wird unter kontinuierlicher CT-Durchleuchtung ueberwacht) oder als Quick-check-Verfahren (wiederholte Aufnahmen einzelner CT-Durchleuchtungsbilder nach jeder Aenderung der Nadel- oder Tischposition) verwendet werden. Fuer die beiden Vorgehensweisen ist insbesondere die Mehrschicht-CT-Fluoroskopie(MSCTF)-Technik mit breiten Detektoren hilfreich, da auch bei Abweichungen aus der Schicht die Nadelspitze in den gleichzeitig akquirierten Nachbarschichten mit abgebildet wird. Mit dieser Technik ist eine millimetergenaue Nadelplatzierung auch bei angulierten Zugangswegen und ausgepraegten atemabhaengigen Bewegungen der Patientenanatomie moeglich. Da eine Verringerung der CT-Durchleuchtungszeit zu einer deutlich reduzierten Strahlenbelastung fuer den Patient und das Personal fuehrt, ist die Kombination der Quick-check-Technik mit einer Low-Milliampere-Technik an MSCTF-faehigen Geraeten zu empfehlen. (orig.)

Paprottka, P.M.; Reiser, M.F.; Trumm, C.G. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Campus Grosshadern, Angiographie und Interventionelle Radiologie, Institut fuer Klinische Radiologie, Muenchen (Germany); Helmberger, T. [Staedt. Klinikum Muenchen, Klinikum Bogenhausen, Institut fuer Diagnostische und Interventionelle Radiologie, Neuroradiologie und Nuklearmedizin, Muenchen (Germany)

2013-11-15

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MRI of esophagus. N staging and more...; MRT des Oesophagus. N-Staging und mehr...  

Energy Technology Data Exchange (ETDEWEB)

Esophageal disease is common. Fluoroscopy with or without fast cine-sequences is able to depict swallowing dynamics precisely and therefore is used in cases with swallowing disturbance, achalasia or diverticula etc. It is performed in addition to primary endoscopy. There is no evidence based indication for MRI in these settings as it is not to rule out postsurgical fistula and incompetence. Endoscopy and endosonography are gold standard for the depiction as well as staging of esophageal tumors hence differentiation of the esophageal wall layers and detection of suspicious lymph nodes is possible. And from both, biopsies may be taken. New techniques as OCT (optical coherence tomography) can demonstrate in situ carcinoma and therefore helps to decide for limited treatments as mucosectomy. For today multimodular treatment strategies in esophageal carcinoma the T-stage will lead to the treatment decision whereas the nodal-stage will give information about the prognosis. As a matter of fact endoscopy is unable to pass a stenosis esophageal tumor in up to 50% of the cases and will therefore not be able to give precise information on both T- and N-stage resulting in a good indication for MRI. Fetal MRI of the chest is a new topic in which MRI seems to be superior to ultrasonography. (orig.) [German] Erkrankungen des Oesophagus sind haeufig. Die Durchleuchtungsuntersuchung, ggf. mit schnellen Cinesequenzen, vermag exakt die Dynamik des Schluckakts darzustellen und wird regelhaft bei Fragestellungen wie ''Verschlucken'' und ''Globusgefuehl'', Verdacht auf Achalsie etc. sowie bei der Suche nach Divertikeln eingesetzt und ergaenzt die primaere Endoskopie. Die MRT besitzt hier derzeit keinen gesicherten Stellenwert - ebenso wie bei der haeufigsten Indikation zur Oesophagus-Breischluck-Untersuchung in der Klinik, der Frage nach Paravasation und Fistelung nach oesophagogastralen Eingriffen. Die exakten Lokalisation eines Oesophagustumors erfolgt durch die Endoskopie als unangefochtenem Goldstandard, die heute unter Verwendung der Endosonographie nicht nur in der Lage ist, die Wandschichten des Oesophagus darzustellen, sondern auch lokoregionaere Lymphknoten zu detektieren vermag und von beidem, wenn suspekt, auch bioptisches Material gewinnen laesst. Neuere Verfahren wie die OCT (optical coherence tomography) versetzen den Endoskopiker zusaetzlich in die Lage, auch Carcinomata in situ zu erkennen und limitierte Behandlungen wie die Mukosektomie einzusetzen. Bei der heute ueblichen multimodalen Therapie des Oesophaguskarzinoms entscheiden die Lage und das T-Stadium ueber die therapeutische Strategie, das N-Stadium ueber die Prognose. Doch ist der Oesophagus bei der Diagnose ''Oesophaguskarzinom'' in 30-50% der Faelle insbesondere mit dem Endosonographieschallkopf nicht passierbar, sodass hier eine klare Indikation zur MRT besteht. Ein neues Feld stellt die intrauterine Diagnostik des fetalen Thorax und der Oesophagusatresie dar. Hier zeichnet sich eine deutlicher diagnostischer Vorteil gegenueber der Sonographie ab. (orig.)

Krupski-Berdien, G. [Krankenhaus Reinbek St.-Adolf- Stift, Abteilung fuer diagnostische und interventionelle Radiologie, Reinbek (Germany)

2007-02-15

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Mehr als 1500 Jahre homoerotische Literatur auf der Iberischen Halbinsel A Survey of over 1500 Years of Gay and Lesbian Literature in Spain and Portugal  

Directory of Open Access Journals (Sweden)

Full Text Available Mit diesem Buch wird ein kaum bekanntes Kapitel der spanischen und portugiesischen Literaturgeschichte aufgeschlagen. Es macht die sozialen und kulturellen Veränderungen des Lebens von schwulen und lesbischen Menschen auf der iberischen Halbinsel im Spiegel der Literatur und durch lebendige Autor/-innenportraits deutlich. Dabei werden nicht nur die deutlichen positiven Veränderungen der letzten 30 Jahre thematisiert, sondern eine fesselnde historische Perspektive zahlreicher Facetten homoerotischer Literatur bis zurück in die andalusische Literatur des Mittelalters aufgezeigt.This book tackles a rarely known chapter in Spanish and Portuguese history of literature. The articles in the anthology document the social and cultural changes in gay and lesbian life on the Iberian peninsula as portrayed in literature. The articles do not only talk about the positive changes brought about by the queer liberation movement during the last thirty years, but offer a fascinating historical perspective on queer writing and queer life ranging from medieval Andalusian literature to present day fiction.

Guido Müller

2002-07-01

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„Vertrauen ist besser, weil Kontrolle nutzt nix!“ – Safer Internet Aktionsmonat 2011 Mehr als 200 Schulen machen mit: Projekte und Ideen aus österreichischen Schulen  

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Full Text Available Am 8. Februar 2011 fand bereits zum achten Mal der Europäische Safer Internet Day statt. In diesem Jahr waren die österreichischen Aktivitäten rund um den Safer Internet Day erstmals nicht nur auf einen einzelnen Tag konzentriert, sondern verteilt auf einen ganzen Monat. Unter dem EU-weiten Motto „It's more than a game, it's your life!“ hatten Saferinternet.at und das Bundesministerium für Unterricht, Kunst und Kultur eingeladen, eigene Projekte zu starten und vorzustellen.

Barbara Buchegger

2011-03-01

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Wie kommt mehr "Familie" in die "Work-Life-Balance"? – Familienorientierung in der medizinischen Aus-, Weiterbildung und Berufstätigkeit [How to add more "Family" to the Work-Life-Balance? – Family Friendliness in Medical Under- and Postgraduate Studies and the Workplace  

Directory of Open Access Journals (Sweden)

Full Text Available [english] Today universities have to compete for the best brains more than ever before. The issues of reconciliation of work/study and family and the work-life balance have become increasingly important recently in higher education policy development as higher education institutions in the competition for the best minds are already forced to tackle these issues, some of which are still novel to them, as they are faced with demographic change. High dropout rates among students with children, increasing shortages of physicians and high sector emigration and high levels of childlessness among graduates serve as indicators for urgent action towards more family-oriented university and faculty strategies.But how can medical schools, hospitals and (teaching hospitals achieve a family-oriented profile? Which key players, which areas of higher education management are relevant to management and decision-making structures? What exemplary measures for designing family-friendly medical studies and work places offer success?The underrepresentation of women in the next generation of scientists also poses an additional challenge to the development of an innovative higher education policy if it is to be sustainable. Thus strategies promoting the next generation and family orientation are key factors for a future-oriented higher education policy. These factors should therefore be seen as leadership strategies which will introduce measures that will make (redesign the university’s profile. To this end, a holistic approach which will lead to fundamental reforms of higher education structures which are outlined below and illustrated with examples are a prerequisite for successful implementation.[german] Hochschulen stehen mehr denn je im Wettbewerb um kluge Köpfe. Die Themen „Vereinbarkeit von Beruf/Studium und Familie“ und „Work-Life-Balance“ haben daher in der jüngsten hochschulpolitischen Entwicklung an Dynamik und Triebkraft gewonnen: Hochschulen im Wettbewerb um exzellente Köpfe müssen sich schon vor dem Hintergrund des demographischen Wandels diesen für sie zum Teil noch neuen Herausforderungen stellen. Hohe Studienabbruchquoten unter Studierenden mit Kindern, steigender Mediziner(innenmangel und deutliche Abwanderungsraten, hohe Kinderlosigkeit unter Akademiker(innen erscheinen dabei als Indikatoren für einen dringenden Handlungsbedarf hin zu einer familienorientierten Hochschul- und Fakultätsstrategie.Wie aber können medizinische Fakultäten, Kliniken und (Lehr-Krankenhäuser ein familienorientiertes Profil gewinnen? Welche Akteurinnen und Akteure, welche Handlungsfelder des Hochschulmanagements sind für die Leitungs- und Entscheidungsstrukturen relevant? Welche exemplarischen Maßnahmen für eine familiengerechtere Gestaltung des Studien- und Arbeitsortes „Medizin“ könnten Erfolg versprechend sein? Die Unterrepräsentanz von Frauen beim wissenschaftlichen Nachwuchs stellt darüber hinaus eine zusätzliche Herausforderung dar, für die eine innovative Hochschulpolitik weitere Maßnahmen entwickeln sollte, um zukunftsfähig zu sein. Nachwuchsförderungsstrategien und Familienorientierung sind demnach entscheidende Faktoren für eine zukunftsorientierte Hochschulpolitik. Diese Faktoren sollten deshalb als Führungsstrategien begriffen werden, um Maßnahmen einzuleiten, die das Profil der Hochschule dahingehend (umgestalten. Voraussetzung für eine erfolgreiche Implementierung ist dabei ein holistisches Konzept, das zu grundlegenden Reformen der Hochschulstrukturen führt, die im Folgenden skizziert und anhand von Beispielen illustriert werden sollen.

De Ridder, Daniela

2012-04-01

24

Topiramat als Phasenprophylaktikum - ein Fallbericht  

Directory of Open Access Journals (Sweden)

Full Text Available Topiramat ist ein neues Antiepileptikum mit einem breiten Wirkspektrum. Aktuelle klinische Studien geben Hinweise darauf, daß Topiramat stimmungsstabilisierende Eigenschaften besitzt und somit effizient in der Behandlung der bipolaren affektiven Störung sein könnte. Vor dem Hintergrund dieser Studienberichte, behandelten wir eine 41jährige, erstmals vor 10 Jahren erkrankte Patientin mit der Diagnose einer therapierefraktären, bipolaren affektiven Störung (Rapid-Cycling mit Topiramat. Im Rahmen ihrer Erkrankung wurde die Patientin insgesamt 12mal stationär aufgenommen und meist aufgrund von akuten manischen Episoden behandelt. Dabei kamen seit 1991 folgende Phasenprophylaktika zur Anwendung: Carbamazepin, Valproat und Lamotrigin ? zuletzt nur mit mäßigem Erfolg. Daraufhin wurde zu Beginn einer neuerlichen manischen Episode ambulant eine Therapie mit Topiramat begonnen. Acht Wochen nach Therapiestart kam die Patientin in stationäre Behandlung. Der Aufenthalt dauerte weniger als drei Wochen; Topiramat wurde von der Patientin gut vertragen. Infolge eines belastenden Lebensereignisses kam es unter kontinuierlicher Therapie mit Topiramat zu einer Destabilisierung des psychischen Zustandsbildes (manische Symptome. Durch eine ambulante Erhöhung der Topiramatdosis bei gleichzeitiger Gabe von Risperidon und Clonazepam konnte jedoch eine neuerliche manische Episode erstmals ambulant behandelt werden. Die Patientin erhält derzeit 200 mg Topiramat pro Tag und ist seit mehr als 20 Monaten nahezu beschwerdefrei.

Letmaier M

2001-01-01

25

Public acceptance must be strengthened. The wind power industry must react to new protests and abandon projects if necessary; ''Es ist noch viel mehr Ueberzeugungsarbeit notwendig''. Windszene muss auf neue Proteste reagieren: auch auf Projekte verzichten  

Energy Technology Data Exchange (ETDEWEB)

Planners of wind power projects must do more to further public acceptance in West Germany, especially in the Eifel and Muensterland regions where tempers are running high. [German] Die Windkraft-Planer muessen noch viel mehr Ueberzeugungsarbeit im Westen der Republik leisten. Vor allem in der Eifel und im Muensterland geht es zurzeit hoch her. (orig.)

Koepke, R.

2001-06-01

26

AMANDA und DØ als Testumgebung für das LHC Computing Grid  

CERN Document Server

Die in Bau befindlichen Experimente am Large Hadron Collider LHC am CERN bei Genf werden größere Datenmengen produzieren und mehr Rechenzeit benötigen als jedes bisherige Experiment in der Hochenergiephysik. Diese Anforderung werden nur noch mit Hilfe von Grid-Technologien in einem weltweiten Verbund lösbar sein. Mit Hilfe der Dissertation sollen 2 laufende Experimente in die schon jetzt vorhandenen Grid-Initiativen eingebunden werden, um daraus Rückschlüsse auf deren weitere Entwicklung zu ziehen. Die Arbeit beginnt mit einer Einleitung in den physikalischen Rahmen und mit einer Motivation für die Notwendigkeit zur Anwendung neuer Technologien im Bereich des Computings. Danach werden die Experimente vorgestellt und eine Einleitung in das Grid-Computing gegeben. Die folgenden zwei Kapitel befassen sich dann mit der Anwendung von Techniken des Grid-Computings im Rahmen des AMANDA- und des DØ-Experiments. Beide sind laufende Experimente mit aktiver Datennahme. Die Simulationssoftware dieser Experimente...

Harenberg, Torsten

27

In search of the limit 90 g/km CO{sub 2} for vehicles weighing more than 1500 kg?; Auf der Suche nach der Grenze 90 g/km CO{sub 2} bei mehr als 1500 kg Fahrzeuggewicht?  

Energy Technology Data Exchange (ETDEWEB)

A reduction of the CO{sub 2} emitted by our motor vehicles is one of the primary research and development goals. Natural gas - as an alternative fuel - has ideal properties for achieving an appreciable reduction in emissions. This is due not only to the approximate 23% more favorable hydro-carbon ratio (H-Gas) of natural gas (high-grade gas) relative to gasoline or diesel, but also to the high knock-resistance properties of the 'natural gas fuel', which can significantly increase the degree of motor efficiency. This article by FKFS describes the technical implementation of a consistent consumption minimization concept based on a hybrid, downsized, turbocharged combustion engine. (orig.)

Bargende, M. [Forschungsinstitut fuer Kraftfahrwesen und Fahrzeugmotoren Stuttgart (FKFS) (Germany)]|[Stuttgart Univ. (Germany). Inst. fuer Verbrennungsmotoren und Kraftfahrwesen; Berner, H.J. [Forschungsinstitut fuer Kraftfahrwesen und Fahrzeugmotoren Stuttgart (FKFS) (Germany)

2005-10-01

28

Energy Conservation Regulation 2002: request for exemption in accordance with paragraph 3 section (3): more confusion than clarity; EnEV 2002: Antrag auf Befreiung nach Paragraph 3 Absatz (3): Mehr Ungereimtheiten als Klarheit  

Energy Technology Data Exchange (ETDEWEB)

The application of the Energy Conservation Regulation currently causes major problems. Sad highlight of the execution chaos and the corresponding helplessness of the planer for technical building equipment is the recommendation: 'Use the exception paragraph 3 - section (3) as a rule and avoid the numerous hindrances'. (orig.) [German] Bei der Anwendung der Energieeinsparverordung (EnEV) treten derzeit grosse Probleme auf. Trauriger Hoehepunkt des Vollzugs-Chaos und der damit verbundenen Hilflosigkeit bei den TGA-Planern ist die Empfehlung: 'Mach die Ausnahme Paragraph 3 - Absatz (3) zur Regel und geh den vielen Ungereimtheiten aus dem Weg'. (orig.)

Jagnow, K. [Trainings- und Weiterbildungszentrum Wolfenbuettel e.V. an der FH Braunschweig (Germany); Wolff, D. [Fachbereich Versorgungstechnik der FH Braunschweig/Wolfenbuettel (Germany)

2002-11-01

29

Thermal construction unit activation with supply air gains significance. Ceilings cooling - supply air heating - more than 50 % energy conservation; Thermische Bauteilaktivierung mit Zuluft gewinnt an Bedeutung. Decke kuehlen - Zuluft erwaermen - mehr als 50% Energie einsparen  

Energy Technology Data Exchange (ETDEWEB)

In the year 2001, in Stuttgart (Federal Republic of Germany) the first office building was established which uses a thermal construction unit activation with air as cooling agent. Today, the system ''Concret-cool'' already is installed in more than 40 buildings. Computations show that due to the room heating by means of internally finned ventilation pipes embedded in concrete more than 50 % less energy in comparison to comparable systems can be used. In his Green Building project ''Skyline Tower'' in Munich (Federal Republic of Germany), also star architect Helmut Jahn uses the know-how of the manufacturer of ventilation systems from Stuttgart. As one of the first multi-storied buildings in Munich, ''Skyline Tower'' with its 23 floors was prized with the pre-certificate of the German quality seal ''sustainable building ''in gold.

Schmid, Wolfgang

2009-05-15

30

Culture and Healthcare in Medical Education: Migrants' Health and Beyond [Medizin und ethnisch-kulturelle Vielfalt in der medizinischen Ausbildung: "Migrantenmedizin" und mehr  

Directory of Open Access Journals (Sweden)

Full Text Available [english] One of the main challenges for teaching programs on immigration, ethnic diversity and health is to transform the commonplace notion of “culture” into a helpful tool for medical training and practice. This paper presents the teaching approach of an interdisciplinary course on “migrants’ health” established at the University of Giessen since 2004, which has recently been complemented by a thematically related collaboration with two universities in Latin America (Ecuador, Peru. The overall goal is to translate the abstract philosophy of into medical practice, and to provide students with the insights, attitudes and skills needed for a fruitful use of concepts like “culture”, “ethnicity” and “migration background”. A key feature of the course is the strong commitment to ethnography as an important means for looking under the surface of superficial attributions to culture, and for grasping the interplay of medicine and health with cultural, social, religious, economic and legal aspects in its particular local and/or individual shape. Three elements of the course are presented to illustrate this approach: First, a unit on Islam and Medicine, as important parts of the local immigrant community are Muslims. The second one deals with psychosomatic aspects, because in case of immigrants, complex symptoms and disease representations like somatisation are easily misinterpreted as “cultural”. The third element consists of a unit with specialized social workers form outside the university, who provide direct insights into the living conditions and health problems of local immigrant communities. [german] Eine der zentralen Herausforderungen für Lehrprojekte zum Thema Medizin und ethnisch-kulturelle Vielfalt besteht in der Vermittlung eines angemessenen Konzepts von „Kultur“. Vor allem gilt es, den exklusiven Fokus auf als „fremd“ wahrgenommene Bevölkerungsgruppen und die Gefahr oberflächlicher kulturelle Zuschreibungen zu überwinden. Der vorliegende Beitrag stellt den Ansatz eines interdisziplinären Kurses zur „Migrantenmedizin“ an der Justus-Liebig-Universität Gießen vor, der jüngst durch ein Kooperationsprojekt zur Stärkung interkultureller Aspekte in der medizinischen Ausbildung mit zwei lateinamerikanischen Universitäten ergänzt wurde (in Ecuador und Peru. Durch den internationalen Vergleich soll das abstrakte Prinzip „think global and teach local“ für den medizinischen Bereich nutzbar gemacht werden. Gleichzeitig wird die Bedeutung der Ethnographie für eine sinnvolle Verwendung von Begriffen wie „Kultur“, „Ethnizität“ oder „Migrationshintergrund“ auch in der Medizin betont. Als wichtigste Forschungsmethode der Kultur- und Sozialanthropologie vermittelt die Ethnographie differenzierte Einblicke in die jeweils konkrete Ausprägung der komplexen Zusammenhänge zwischen Krankheit, Medizin und „Kultur“ – jenseits von Stereotypien und unter explizitem Einschluss der im Einzelfall relevanten sozialen, religiösen, ökonomischen und rechtlichen, aber auch medizinischen Aspekte. Der Artikel verdeutlicht die Umsetzung dieser Perspektive in der medizinischen Ausbildung exemplarisch anhand von drei Lehreinheiten des Kurses an der JLU Gießen: Ein Modul zum Thema „Islam und Medizin“, eines zu psychosomatischen Aspekten und eine dritte Einheit, in der Sozialarbeiterinnen eines lokalen Migrationsdienstes unmittelbare Einblicke in die reale Lebenswirklichkeit von Migrant/innen vermitteln.

Soydan, Nedim

2010-05-01

31

Der Glaube als Erkenntnisquelle Belief as the source of knowledge  

Directory of Open Access Journals (Sweden)

Full Text Available Seit ihrer Kanonisation 1998 und Ernennung zur Mit-Patronin Europas 1999 steht die 1942 in Auschwitz ermordete Phänomenologin Edith Stein, 1922 vom jüdischen zum christlichen Glauben konvertiert und 1933 als Benedicta vom Kreuz in den Kölner Karmel eingetreten, mehr denn je im Blickfeld der Öffentlichkeit. Die Bedeutung ihrer wissenschaftlichen Arbeit u. a. als Assistentin von Edmund Husserl in Freiburg und als Dozentin am Deutschen Institut für wissenschaftliche Pädagogik in Münster, aber auch in privaten Studien wurden im Juli 2000 im Rahmen eines Symposiums des Internationalen Edith Stein Instituts in Würzburg diskutiert. Die Beiträge der vorliegenden Publikation beleuchten breit gefächert Aspekte des Werks und seiner Interpretation mit dem Ziel, die Philosophin neu zu entdecken und die bisherige Forschung zu intensivieren.Since her canonisation and her appointment as Martyr and Co-Patroness of Europe in 1999, Edith Stein has, more than ever, been in the public eye. Murdered in Auschwitz in 1942, the phenomenologist converted from Judaism to Catholicism in 1922 and entered the Carmel of Cologne in 1933 as Teresa Benedicta of the Cross. In July 2000, at a symposium of the International Edith Stein Institute in Wurzburg, the significance of her academic work (among other things as an assistant to Edmund Husserl in Freiburg and as a lecturer at the German Institute for Pedagogy in Munster was discussed. The wide-ranging contributions in this publication highlight aspects of this work and its interpretation with the aim of rediscovering the philosopher and of intensifying research conducted to date.

Andrea Hartwig

2004-03-01

32

Explosionsfeste Transportbehälter – mehr Sicherheit für das Transportwesen  

Directory of Open Access Journals (Sweden)

Full Text Available Weltweit ist eine Zunahme terroristischer Aktivitäten zu verzeichnen, sodass allgemein damit gerechnet werden muss, dass auch das zivile Verkehrs- und Transportwesen ein bevorzugtes Ziel terroristischer Anschläge darstellt. Mehrfach wurden schon Sprengkörper in Transportmittel des öffentlichen und zivilen Personen- aber auch Güterverkehrs eingeschleust, um die Bevölkerung durch materielle Zerstörung und massive Personenschäden einzuschüchtern und zu beängstigen. Daher ist eine Anpassung der sich derzeit im Einsatz befindlichen Transportbehälter an die geänderten Rahmenbedingungen unerlässlich, um auch den Schutz vor Sprengkörpern, die gemeinsam mit dem Handgepäck in Luft-, Land- und Wasserfahrzeuge eingeschleust werden, zu gewährleisten. The worldwide increase of terrorist activities leads to the assumption that the civilian transportation and traffic system, too, is a preferred target of terrorist attacks. Several times, explosive charges have already been smuggled into means of public transport and also of goods traffic to intimidate and frighten the population through material destruction and massive personal damage. This is why it is necessary to adapt the containers currently used to the changed conditions, to guarantee the protection against explosives that are smuggled into aircrafts, surface vehicles and watercraft with the hand luggage.

Dipl.-Kff. Johanna Haag

2007-04-01

33

Reizdarmsyndrom: Mehr Augenmerk auf die Psyche  

Directory of Open Access Journals (Sweden)

Full Text Available Die Prävalenz des Reizdarmsyndroms hat sich in den vergangenen Jahren kaum verändert, obwohl es wesentlich stärker in den Fokus ärztlicher Bemühungen gerückt ist. Zu einem wesentlichen Anteil liegt dies an der Komplexität der Erkrankung und ihrem Ursprung an der Schnittstelle zwischen physischem und psychischem Geschehen. Neue Ergebnisse unterstreichen die Bedeutung psychotherapeutischer Ansätze und dabei insbesondere diejenige der bauchzentrierten Hypnose im Gesamtkonzept der stufenweisen Behandlung der Patienten mit Reizdarmsyndrom.

Moser G

2014-01-01

34

Strategien für mehr Arbeit und soziale Gerechtigkeit  

OpenAIRE

Der Beitrag vom Vorsitzenden des DGB, Dieter Schulte beschäftigt sich mit den politischen und strategischen Konsequenzen der beschäftigungspolitischen Untätigkeit von Politik und Wirtschaft. Jürgen Hoffmann umreißt die gewerkschaftspolitischen Handlungsspielräume unter den Bedingungen von globalisierten Ökonomien, insbesondere im Hinblick auf soziale Gerechtigkeit und ökologische Vernunft. Hans Jürgen Sattler und Walter Siebel thematisieren die sozialen und beschäftigungswirksamen F...

Schulte, Dieter

1997-01-01

35

More wind turbines please; Mehr Muehlen erbeten  

Energy Technology Data Exchange (ETDEWEB)

After Nordrhein-Westfalen and Schleswig-Holstein, Bavaria is the third German state to issue a wind power decree. Many of the wind power industry's demands have been considered, but there is still criticism. Some parties demand amendments.

Zimmermann, Joerg-Rainer

2012-02-15

36

Wortbildungsangaben als Hilfe für den Zugriff auf andere Datentypen und als Hilfe bei kommunikativen und kognitiven Informationsbedürfnissen  

DEFF Research Database (Denmark)

"Grundsätzlich können unendlich umfangreiche Mengen" von Daten eingespeist werden, schreiben Ulrike Haß und Ulrich Schmitz in der Einleitung zum Themaheft "Lexikographie im Internet" (Lexicographica 26, 2010). Das ist zwar nicht korrekt, da man zwar enorm große Mengen in einer lexikographischen Datenbank erfassen kann, aber sicher nicht unendlich viele. Schwerwiegender ist jedoch der Denkfehler, der daher rührt, dass die beiden Herausgeber den Unterschied zwischen einer Datenbank und einem Wörterbuch nicht beachten: "Je mehr Informationen angeboten werden, desto schwerer wird es dem Nutzer, genau die zu finden, die er braucht." (Haß/Schmitz 2010, 4). Dies gilt nur dann, wenn auch Internetwörterbücher notwendigerweise polyfunktionale Wörterbücher sein sollen, die alle Daten von der lexikographischen Datenbank zeigen, wie es die meisten Papirwörterbücher tun. Entsprechend gilt, dass Bonusangaben eher unnütz sind ("Sind Wörterbücher ausschließlich dazu da, Fragen zu beantworten? Nein, sie sollten auch zu Fragen anregen, solange sie doch auch in irgendeinem Zusammenhang mit Bildung stehen." (Haß/Schmitz 2010, 10)). Man sollte grundsätzlich trennen zwischen der Datenbank und den daraus erstellten Wörterbüchern. Wenn man monofunktionale Wörterbücher konzipiert, verschwindet das Problem vom Informationstress nicht, kann aber größtenteils vermieden werden. Dieses Problem stellt sich in besonderem Masse zu Wortbildungsangaben, die für einige Informationsbedürfnisse wichtig, für andere irrelevant sind, d.h. in einigen Wörterbüchern nützlich sind, in anderen nicht. Prinzipiell gilt, dass Wortbildungsangaben nicht mitgenommen werden sollen für Rezeptionswörterbücher. Auch für Produktionswörterbücher gilt, dass Angaben von allen möglichen Wortbildungen zum Informationsstress führen, dass man stattdessen eine geringe Anzahl der prototypischen Wortbildungen anführen soll (hierzu mehr im Vortrag). Schließlich können sehr reichhaltige Wortbildungsangaben und auch Wortbildungsregeln in vielen Fällen in einem kognitiven Wörterbuchnützlich sein, d.h. in einem Informationswerkzeug, das möglichst viel Wissen bieten will. Wortbildungsdaten in der Datenbank können auch eine andere Funktion erfüllen, und zwar als Zugriffshilfe auf Daten in anderen Wörterbuchartikeln, wenn eine bestimmte Wortbildung nicht lemmatisiert ist. Die morphologischen theoretischen Überlegungen, die metalexikographischen zu monofunktionalen Informationswerkzeugen, sowie Prinzipien des Zugriffs auf Daten mithilfe von Wortbildungsdaten einer Datenbank werden anhand einer Datenbank vorgestellt, aus der insgesamt sechs Wörterbücher herausgezogen werden.

Bergenholtz, Henning

2013-01-01

37

Kinematografische Propaganda und Zensur in Österreich-Ungarn von 1914–1918 als gescheitertes kybernetisches Modell  

Directory of Open Access Journals (Sweden)

Full Text Available (Medien-Pädagogik, verstanden als Medienverbund zur programmierten "Unterrichtung" einer breiten Masse wurde bereits vor 1914 erfahren. Zweifelsohne kam es jedoch während dem Ersten Weltkrieg zu einer intensiven Orchestrierung der zur Verfügung stehenden Medien. Die angestrebte Volkserziehung kann dabei als kybernetisches Regelkreismodell betrachtet werden. Als ganz spezielles systemimmanentes Instrument, stellte sich dabei das Kino heraus. Anfangs etwas zögerlich, verstand man es mit Verlauf des Krieges auch in der Donaumonarchie, die Möglichkeiten der bewegten Bilder immer umfassender auszunützen. Das Kino sollte als Regler, dem Publikum Führungsgrößen vor Augen führen und das einzelne Individuum gleichzeitig zu einer Art Selbstregulation auffordern. Vorstellungs- und Wertewelten der Menschen sollten homogenisiert werden und das System in dieser Weise stabilisieren. Offenes Feedback war unerwünscht; Grundstimmungen und Diskurse innerhalb der Bevölkerung blieben jedoch nicht unbemerkt und wurden auf der Leinwand bearbeitet, wobei begründete Befürchtungen, Zweifel und Ängste, zu entkräften versucht wurden. Mit fortschreitender Kriegsdauer taten sich Zensur und Propaganda immer schwerer, ein geschöntes Bild der Situation glaubhaft darzustellen. Schließlich vermochte das Flimmern der Leinwände, die Botschaften des Systems nicht mehr zu vermitteln. Das kybernetische Modell der Volkserziehung über Kamera und Leinwand, welches die Gesellschaft militärisch überprägte, Überlegenheit predigte, Gewalt normalisierte und das kriegsbedingte Sterben humanisierte, musste letztlich scheitern. Der vorliegende Artikel soll einen kurzen Einblick in den Aufbau dieses – letztlich gescheiterten – regulativen Werkes der kinematografischen Propaganda und Zensur in Österreich-Ungarn geben, wobei der Fokus auf der dokumentarischen Berichterstattung vom Krieg liegt, die eine vermeintliche Realität repräsentieren sollte.

Paul Winkler

2014-12-01

38

AL Amyloidosis  

OpenAIRE

Abstract Definition of the disease AL amyloidosis results from extra-cellular deposition of fibril-forming monoclonal immunoglobulin (Ig) light chains (LC) (most commonly of lambda isotype) usually secreted by a small plasma cell clone. Most patients have evidence of isolated monoclonal gammopathy or smoldering myeloma, and the occurrence of AL amyloidosis in patients with symptomatic multiple myeloma or other B-cell lymphoproliferative disorders is unusual. The key event in the development o...

Desport Estelle; Bridoux Frank; Sirac Christophe; Delbes Sébastien; Bender Sébastien; Fernandez Béatrice; Quellard Nathalie; Lacombe Corinne; Goujon Jean-Michel; Lavergne David; Abraham Julie; Touchard Guy; Fermand Jean-Paul; Jaccard Arnaud

2012-01-01

39

Kritische Mangelperfusion als wichtigster pathophysiologischer Faktor für die Behandlung des ischämischen Insults  

Directory of Open Access Journals (Sweden)

Full Text Available Die Verminderung der Blutversorgung von Arterien des Gehirns als Ursache des Schlaganfalls führt zu plötzlich eintretenden funktionellen Ausfällen, bei längerem Bestehen zu irreversiblen neurologischen und morphologischen Defekten. Für das funktionell gestörte, aber morphologisch noch intakte Gewebe - die Penumbra - besteht die Möglichkeit der Erholung, wenn die Durchblutung innerhalb einer kurzen Zeitspanne - dem therapeutischen Fenster - wieder auf ein ausreichendes Niveau angehoben wird. Die Identifikation von irreversibel geschädigtem ischämischem Gewebe und dessen Differenzierung von der nur funktionell gestörten Penumbra ist für die Einleitung erfolgversprechender therapeutischer Maßnahmen von entscheidender Bedeutung. Dies kann durch funktionelle bildgebende Verfahren erfolgen, wobei der Positronenemissionstomographie (PET zur Quantifizierung von Durchblutung und Energiestoffwechsel und zur Darstellung der Benzodiazepinrezeptoren als Marker der neuronalen Integrität eine besondere wissenschaftliche Bedeutung zukommt. Damit konnten in den ersten Stunden nach Insult mehr als 50 % des endgültigen Infarkts dem bereits irreversibel geschädigten Gewebe und 20 % der Penumbra zugeordnet werden. Nur ein relativ kleiner Anteil - etwa 12 % des endgültigen Infarkts - betraf Gewebe, das in den ersten Stunden ausreichend perfundiert war. Der raschen Reperfusion kommt somit in der Therapie des Schlaganfalls die größte Bedeutung zu, während Maßnahmen, die mit biochemischen, molekularen oder entzündlichen Noxen interferieren sollen, bisher klinisch nicht erfolgreich waren. Die Effizienz der Reperfusionstherapie durch systemische Thrombolyse wurde in kontrollierten Studien unter Beweis gestellt; auch die breitere Anwendung in der klinischen Routinebehandlung ist bei Berücksichtigung der Ein- und Ausschlußkriterien ohne vergrößertes Risiko möglich, wobei die Erfolgsraten mit den Studienergebnissen vergleichbar sind.

Heiss W-D

2002-01-01

40

High-performance vacuum tubes for more energy efficiency. Building-integrated CPC vacuum tube collectors unite several functions.; Hochleistungs-Vakuumroehren fuer mehr Energieeffizienz. Gebaeudeintegrierte CPC-Vakuumroehren-Kollektoren vereinen mehrere Funktionen  

Energy Technology Data Exchange (ETDEWEB)

The performance of solar collectors primarily contributes to increased efficiency and reduced operating costs of solar thermal systems. With the use of building-integrated CPC vacuum tube collectors an extremely high energy yield is achieved on a smaller collector gross area. As a building-integrated system solution the CPC facade provide panels in addition to its use as spandrel panels within the glazed buildings not only an architectural design element, but unite as a multifunctional component for several functions. [German] Die Leistungsfaehigkeit der Solarkollektoren traegt primaer zur Effizienzsteigerung und Reduzierung der Betriebskosten einer Solarthermieanlagen bei. Mit dem Einsatz gebaeudeintegrierter CPC-Vakuumroehrenkollektoren wird auf einer kleineren Kollektorbruttoflaeche ein extrem hoher Energieertrag erreicht. Als gebaeudeintegrierte Systemloesung bieten die CPC-Fassadenkollektoren neben dem Einsatz als Bruestungselemente auch innerhalb der verglasten Gebaeuden nicht nur ein architektonisches Gestaltungselement, sondern vereinen als multifunktionaler Bestandteil noch mehrere Funktionen.

Theiss, Eric

2013-10-15

41

The transjugular portosystemic stent shunt (TIPSS) as an intervention in clinical complication of portal hypertension; Der transjugulaere portosystemische Stentshunt (TIPSS) als Intervention bei klinischen Komplikationen der portalen Hypertonie  

Energy Technology Data Exchange (ETDEWEB)

Most frequent complications in patients with liver cirrhosis are due to portal hypertension. Beside ascites circumvent vessles formate with vasodilatation. Due to counterregulation a secondary hyperaldosteronism develops with release of vasocontrictive agents. If conservative and endoscopic methods fail, indication for building a portosystemic shunt is given. The TIPSS procedure is less invasive than the surgical method of Warren-Shunt, so the radiological intervention has replaced surgery. Reducing the portal pressure by the shunt, the clinical complications change for the better. Still problems are defined as hepatic encephalopathy and right ventricular heart failure. Regular follow up investigations have to be performed to detect complications in the shunt. Using regular clinical and radiological check up TIPSS is of clinical benefit with good long term results. (orig.) [German] Die haeufigsten Komplikationen bei Patienten mit einer Leberzirrhose lassen sich auf das Vorliegen einer portalen Hypertension zurueckfuehren. Neben einer Aszitesbildung kommt es zur Vasodilatation mit Ausbildung portaler Umgehungskreislaeufe, gegenregulatorisch zu einem sekundaeren Hyperaldosteronismus und Ausschuettung vasokonstriktiver Substanzen. Sind mittels konservativer und endoskopischer Methoden die Komplikationen nicht mehr zu beherrschen, ist die Indikation zur Shuntanlage gegeben. Wegen der geringeren Invasivitaet einer TIPSS-Anlage gegenueber der operativen Methode eines Warren-Shunts hat sich die interventionell radiologische Methodik in den letzten Jahren immer mehr durchgesetzt. Durch den mittels Shuntanlage reduzierten Pfortaderdruck kommt es zu einer deutlichen klinischen Besserung der unterschiedlichen Komplikationen. Als klinisch problematische Symptome bei der Shuntanlage sind die hepatische Enzephalopathie und eine Zunahme der Rechtsherzbelastung zu werten. Um Komplikationen im Bereich des Shunts frueh zu erkennen, muss dieser engmaschig kontrolliert werden. Unter enger klinischer und radiologischer Kontrolle ist die Anlage eines intrahepatischen portosystemischen Shunts jedoch auch als laengerfristig effektive Methode zu werten, mit einer deutlichen Verbesserung der klinischen Symptomatik. (orig.)

Thalhammer, A.; Jacobi, V.; Schwarz, W.; Balzer, J.; Abolmaali, N.; Vogl, T.J. [Frankfurt Univ. (Germany). Zentrum der Radiologie

2001-10-01

42

ALS Association  

Science.gov (United States)

... and nationwide advocacy while also empowering people with Lou Gehrig's Disease and their families to live fuller lives by providing them with compassionate care and support. ... on this website are owned and copyrighted by The ALS Association. ©2014 Lou Gehrig® used with permission of the Rip Van ...

43

Al Composites  

Science.gov (United States)

In the present study, cold spraying technique was used to fabricate a metal matrix composite (MMC) that consists of Ni matrix and 20 vol.% Ni3Al particles at two different particle sizes as reinforcement. This study intends to investigate the effect of reinforcement particle size on microstructural and mechanical properties of cold sprayed MMCs. Two different Ni3Al powders with nominal particle size of -45 to +5 and +45 to 100 ?m were used as reinforcement in this study. Cold sprayed Ni-Ni3Al samples were subjected to the microstructural observation and characterization prior to any mechanical testing. Then, samples were tested using nano-indentation, Knoop hardness, Vickers hardness, and Resonance frequency to evaluate their mechanical properties. No significant changes were observed in microstructural characteristics due to different particle sizes. The results obtained from a variety of mechanical testings indicated that the increasing reinforcement particle size resulted in the slight reduction of mechanical properties such as elastic modulus and hardness in cold sprayed MMCs. The mechanical interlock between deposited particles defines the bonding strength in cold sprayed samples. Small size particles have a higher velocity and impact resulting in stronger interlock between deformed particles.

Chandanayaka, Tharaka; Azarmi, Fardad

2014-05-01

44

Eta, the symbol of rational company policy; Eta als Branchen- und Unternehmensleitbild  

Energy Technology Data Exchange (ETDEWEB)

Successful operation of a company today requires the readiness and the ability to keep up an open and permanent dialogue with the public, with social institutions, and also with the company employees. Next to the economic criteria, e.g. market position and profitability, it is the social acceptance that has become a key criterion. A company strategy based on economic criteria alone is no longer sufficient; also, a lack of social acceptance will sooner or later also have negative effects on the economic situation. (orig.) [Deutsch] Die Bereitschaft und die Faehigkeit, mit den Buergern sowie mit den Institutionen unserer Gesellschaft, aber auch mit den eigenen Mitarbeitern in einen permanenten und offenen Dialog zu treten, ist fuer moderne Unternehmen zu einem lebensnotwendigen Erfolgsfaktor geworden. Neben unternehmenswirtschaftlichen Kriterien wie der Marktposition und der Rentabilitaet hat sich die Akzeptanz im gesellschaftlichen Umfeld zu einem Schluesselkriterium entwickelt. Ein Denken ausschliesslich in wirtschaftlichen Kategorien erweist sich immer mehr als unzureichend, zumal ein Mangel an Akzeptanz frueher oder spaeter auch die wirtschaftliche Situation negativ beeinflussen wird. (orig.)

Cahn von Seelen, U.

1995-06-12

45

Genetic Testing for ALS  

Science.gov (United States)

... with ALS and Caregivers Newly Diagnosed ALS Registry Military Veterans Augmentative Communication Caregivers Resources ALS Insight Newsletter ... 2014 Related PDFs FYI Genetic Testing Related Factsheets Nursing Management in ALS NEALS Clinical Trial Search Glutamate ...

46

Amyotrophic Lateral Sclerosis (ALS)  

Science.gov (United States)

... 212-420-7387 ALS Therapy Development Institute 300 Technology Square Suite 400 Cambridge, MA 02139 info@als. ... Genetic mutation linked to inherited forms of ALS, dementia Scientists have identified the most common genetic cause ...

47

ALS (Amyotrophic Lateral Sclerosis)  

Science.gov (United States)

Amyotrophic Lateral Sclerosis (ALS) Fact Sheet Clinical Trials Natural History and Biomarkers of C9ORF72 ALS and FTD The purpose ... can I get more information? What is amyotrophic lateral sclerosis? Amyotrophic lateral sclerosis (ALS), sometimes called Lou ...

48

Greater safety through lean management?; Mehr Arbeitssicherheit durch Lean Management?  

Energy Technology Data Exchange (ETDEWEB)

Undertakings have to adopt very quickly to the new framework and conditions of international competition and the changed limiting conditions of production processes. New management strategies and organizational structures are discussed, and these include slogans such as `lean management`, `business re-engineering` or even `the fractural undertaking`. Departmental thinking is now replaced by orientation towards customers and business processes, which ultimately serve the customer and should satisfy his interests. In conclusion, the contribution of employment protection to the actual business processes is discussed. (orig.) [Deutsch] Die Unternehmen muessen sich sehr schnell an die neuen Rahmenbedingungen der internationalen Wettbewerbssituation und die veraenderten Randbedingungen der Produktionsprozesse anpassen. Neue Managementstrategien und Organisationsformen werden diskutiert, Schlagworte dabei sind Lean Management, Business Reengineering oder auch das Fraktale Unternehmen. Das Abteilungsdenken wird jetzt abgeloest durch eine Orientierung an Kunden und an Geschaeftsprozessen, die letztlich dem Kunden diesen und ihn zufriedenstellen sollen. Konsequenterweise wird dabei auch der Beitrag des Arbeitsschutzes zu den eigentlichen Geschaeftsprozessen diskutiert. (orig.)

Bauer, W. [Fraunhofer Inst. fuer Arbeitswirtschaft und Organisation, Stuttgart (Germany)

1997-08-01

49

Kurokawa's secret. Or: Why you need lemonade to feed more than 10 kW of solar power into the public grid; Kurokawas Geheimnis. Oder: Warum man in Japan Brause braucht, um mehr als zehn Kilowatt Solarstrom ans Netz zu bringen  

Energy Technology Data Exchange (ETDEWEB)

Japan was among the first countries to think about solar power in gigawatt dimensions, but then the country opted increasingly for nuclear power. Now, after the earthquake and tsunami in March and with the ongoing nuclear catastrophe, there appears to be a renaissance of renewable energy sources and especially photovoltaic conversion. To make it happen, the government must take steps and permit competition in the energy market.

Krause, Matthias B.

2011-05-15

50

Underground- and surface technologies for joint flooding of gas caves; Unter- und Uebertagetechnik als Einheit zur Flutung von Gaskavernen  

Energy Technology Data Exchange (ETDEWEB)

After 20 years of operation the oldes caves in the Bernburg storage VNG AG had to repair the facilities. This required flooding of the caves from the start. At the same time geomechanical reserves which were reevaluated on the basis of redimensioning could be used by deepening. Flooding and relocation of the displaced gas should not disturb gas storage and brine extraction. As one of the caves was filled with gas for the first time it was possible to use the brine. Flooding and gas filling were coupled. [Deutsch] Nach mehr als 20jaehriger Betriebszeit der aeltesten Kavernen auf dem Speicher Bernburg stand fuer die VNG AG die Aufgabe der Reparatur. Der Umfang der Arbeiten machte von Anfang an das vollstaendige Fluten der Kavernen erforderlich. Gleicheitig ergab sich dabei die Moeglichkeit, seinerzeit verbliebene geomechanische Reserven, die auf Basis einer auf aktuelle Erkenntnisse beruhenden Neudimensionierung bewertet wurden, durch Nachsolung auszuschoepfen. Die Heranfuehrung des Flutmediums und die Umlagerung des verdraengten Gases sollten ohne nachteilige Rueckwirkung auf den Gasspeicher- und Solegewinnungsbetrieb erfolgen. Da zu diesem Zeitpunkt eine Kaverne in der Phase der Gaserstbefuellung stand, konnte die ausgetragene Sole genutzt werden. Flutprozess und Gaserstbefuellung wurden somit im direkt gekoppelten Betrieb durchgefuehrt. (orig./MSK)

Raudonus, K.; Miersch, D. [UGS GmbH, Mittenwalde (Germany); Haensler, G. [Verbundnetz Gas AG, Leipzig (Germany)

1998-12-31

51

Four-dimensional data assimilation as a method for coupling two meteorological model systems of different scales; Vierdimensionale Datenassimilation als Methode zur Kopplung zweier verschiedenskaliger meteorologischer Modellsysteme  

Energy Technology Data Exchange (ETDEWEB)

A method of coupling two meteorological models of different scales must meet certain requirements: First, even a big difference in resolution between the two models must not produce disturbances in the smaller-scale model. This means that most nesting approaches are unfit for the purpose. The method presented here is not limited to meteorological models. It can be enhanced without much difficulty to dispersion models taking account of chemical atmospheric reactions, as e.g. in the CTM of the EURAD model or in DRAIS as an enhancement of the KAMM version. [German] Das Ziel dieser Arbeit bestand in der Entwicklung eines geeigneten Kopplungsverfahrens zweier verschiedenskaliger meteorologischer Modelle, das in einem Ein-Weg-Nesting dem kleinerskaligen Modell ermoeglicht, sowohl instationaere superskalige Verhaeltnisse als auch modellinterne kleinraeumige Prozesse miteinander zu verbinden. Im Rahmen des Projektes TFS mussten hierbei entscheidende Bedingungen an das Kopplungsverfahren gestellt werden. Allen voran darf vor allem ein auch grosser Unterschied in der Aufloesung der beiden verschiedenskaligen Modelle keine kuenstlichen Stoerungen im kleinerskaligen Modell produzieren. Somit scheiden die sonst ueblichen Nestingansaetze fuer diesen Fall aus. Das Verfahren ist derart konzipiert, dass es sich nicht auf rein meteorologische Modelle beschraenkt. Eine Ausweitung auf Ausbreitungsmodelle unter Beruecksichtigung chemischer Reaktionen in der Atmosphaere, wie sie etwa im CTM des EURAD-Modells oder im DRAIS als Erweiterung der KAMM-Version zur Verfuegung stehen, stellt keinen allzu grossen Schritt mehr dar. (orig.)

Wilms-Grabe, W.

2001-10-01

52

Primary AL Amyloidosis  

Science.gov (United States)

... be administered in combination with other treatments. REVLIMID (lenalidomide) (CC-5013) is a immunomodulatory drug; a derivative ... AL amyloidosis. Findings from initial trials indicate that lenalidomide can be effective in treating AL amyloidosis. There ...

53

Pornographie als Metapher  

Directory of Open Access Journals (Sweden)

Full Text Available In diesem Artikel werden unterschiedliche metaphorische Verwendungen des Pornografiebegriffs und deren Implikationen untersucht. Während die Existenz von Pornografie der feministischen Anti-Porno-Bewegung als Erklärung für die anhaltende Diskriminierung von Frauen in westlichen Gesellschaften dient, nutzen rechtskonservative Kräfte den Pornografievorwurf als Rechtfertigung für die Zensur von als deviant empfundenen Identitäten und sexuellen Praktiken.

Caroline Schubarth

2010-02-01

54

What Is ALS?  

Science.gov (United States)

... l ateral s clerosis (ALS), often referred to as "Lou Gehrig's Disease," is a progressive neurodegenerative disease that affects nerve ... to remember that ALS is a quite variable disease; no two people will have the same journey or experiences. ... by The ALS Association. ©2010 Lou Gehrig® used with permission of the Rip Van Winkle ...

55

Volver al desarrollo  

Directory of Open Access Journals (Sweden)

Full Text Available El desarrollo, categoría empleada para expresar el crecimiento económico, surge durante la "guerra fría" y si bien fue propuesta por teóricos metropolitanos, se asumió en Latinoamérica como parte de los instrumentos disponibles para lograr el crecimiento y alternativa al socialismo. El desarrollo mantuvo su vigencia entre 1945 y 1975, cuando al advenimiento del neoliberalismo fue paulatinamente retirado de la agenda de las preocupaciones nacionales e internacionales. Al iniciarse el siglo xxi, el fracaso del mercado autorregulado trajo de nueva cuenta al debate los problemas del desarrollo, lo que obliga a revisarlo críticamente, tanto como al concepto mismo para mostrar su carácter colonial, si se quiere construir caminos ajenos al neoliberal y superar los problemas que han hecho de Latinoamérica una de las regiones más desiguales del mundo.

Jaime Ornelas Delgado

2012-01-01

56

Del latín al rumano  

Directory of Open Access Journals (Sweden)

Full Text Available

Marius Sala, Del latín al rumano. Versión española de Valeria Neagu, París, Unión Latina - Bucarest, Univers enciclopedic, 2002. El texto se dirige al lector corriente, no especialista, y por eso el aparato técnico-bibliográfico no se presenta en el curso de la exposición.

Montes Giraldo José Joaquín

2003-06-01

57

[Phenotypic variation in ALS].  

Science.gov (United States)

Making a diagnosis of typical amyotrophic lateral sclerosis (ALS) is not a tough job, but when it comes to atypical forms of motor neuron disease (MND) which are not uncommon in clinical setting, we may have some difficulty to diagnose ALS/MND. There is striking phenotypic variation in sporadic ALS/MND, such as frail arm syndrome (brachial amyotrophic diplegia), pseudopolyneuritic form, hemiplegic type, ALS/MND with markedly extended involvement beyond the motor system, and MND with basophilic inclusion bodies. These variations must be recognized if physicians are to tailor advice on disease progression, prognosis, drug therapy, and care to the needs of the individual. Clinical trials of new therapeutic agents have been performed, on the assumption that patients with ALS/MND have the same underlying etiology, addressing the heterogeneous population of the patients under a single diagnostic category. This can be detrimental to the well-being of the individual, because clinical heterogeneity may mask drug effects in clinical trials. The attempt to categorize subgroups based on the clinical and pathological backgrounds within the spectrum of ALS/MND may be a critical step in facilitating clinical research in ALS/MND. Definition of clinicopathologic syndromes in patients with ALS/MND is an important challenging task that cannot be ignored. PMID:17432191

Sasaki, Shoichi

2006-11-01

58

Al - BASED CAST COMPOSITES  

Directory of Open Access Journals (Sweden)

Full Text Available The economy is very important feature nowadays in themarket. The researches are playing an important role inengineering field to increase the life of machine parts /components and decrease the cost. The compositematerials have the potential to replace widely used steeland aluminium due to their good characteristics withbetter performance. The Al-based composites have foundextensive applications in automobile industries andaerospace industries due to their increased stiffness,strength, thermal conductivity and wear resistanceproperties. A number of particulate phases have beenemployed in the Al-alloy matrix. The cast aluminiumceramicparticulate composites are finding applications inpistons, connecting rods, cylinder liner, engine cylinderblock, electrical contacts etc.The present investigation isbased on study of the effect of particulate phase on theSEM study, micro-hardness, elastic modulus, tensilestrength and the wear behaviour of Al-5 % SiC-7 % Fe,Al-10 % SiC-6 % Fe and Al-15 % SiC-5 % Fe composites.

Rakesh Kumar Yadav

2011-08-01

59

[Environmental factors in ALS].  

Science.gov (United States)

ALS is likely to be a disorder of multifactorial origin. Among all the factors that may increase the risk of ALS, environmental ones are being studied for many years, but in the recent years, several advances have pointed to a new interest in their potential involvement in the disease process, especially for the cyanotoxin BMAA. Food containing BMAA has been found on Guam, a well-known focus of ALS/parkinsonism/dementia and high levels of BMAA have been identified into the brain of these patients. The BMAA cyanotoxin is potentially ubiquitous and have also been found into the food of patients who died from ALS both in Europe and USA. BMAA can be wrongly integrated into the protein structure during mRNA traduction, competing with serine. This may induce abnormal protein folding and a subsequent cell death. Heavy metals, such as lead or mercury may be directly toxic for neuronal cells. Several works have suggested an increased risk of ALS in individuals chronically exposed to these metals. Exposure to pesticides has been suggested to be linked to an increased risk of developing ALS. The mechanism of their toxicity is likely to be mediated by paraoxonases. These proteins are in charge of detoxifying the organism from toxins, and particularly organophosphates. To date, there are insufficient scientific data to suggest that exposure to electromagnetic fields may increase the risk of having ALS. We are particularly missing longitudinal cohorts to demonstrate that risk. PMID:24703731

Juntas-Morales, Raul; Pageot, Nicolas; Corcia, Philippe; Camu, William

2014-05-01

60

ALS synchrotron radiation shielding  

International Nuclear Information System (INIS)

This note discusses the assumptions and results of synchrotron radiation shielding estimates for ALS bend magnet and wiggler beamlines. Estimates of gas bremsstrahlung production are not included and are dealt with elsewhere

61

About ALS: FAQ  

Science.gov (United States)

... a wealth of new scientific understanding about the physiology of this disease. Lou Gehrig , with whom ALS ... that this substance may be safely given. Some sports medicine experts and trainers are unsure about potential ...

62

Selbstkritik als wissenschaftliches Projekt?  

Directory of Open Access Journals (Sweden)

Full Text Available Wallner kritisiert die aktuelle feministische Darstellung der rund 30jährigen Geschichte der Mädchenarbeit als „Legendenbildung“ (S. 9: Sie verkürze und verschweige im Interesse einer Selbst-Heroisierung und sei daher ideologisch. Als eine derjenigen, die seit zwanzig Jahren feministische Mädchenarbeit und -politik betreibt, arbeitet die Autorin damit auch ihre eigenen (Nicht-Bezugnahmen kritisch auf. Ihr grundlegendes Interesse ist es, eine aus ihrer Sicht erforderliche Neupositionierung der Mädchenarbeit in der Jugendhilfe im Zeitalter von Gender Mainstreaming zu befördern.

Barbara Scholand

2007-11-01

63

Leakage current behaviors of Al/ZrO2/Al and Al/YSZ/Al devices  

Science.gov (United States)

The leakage current behaviors of Al/ZrO2/Al and Al/yttria stabilized zirconia (YSZ)/Al devices are investigated for resistive random access memory (RRAM) applications. A silicon oxide layer (450 nm) is first formed on a Si wafer by thermal oxidation. Onto it an Al bottom electrode (270 nm), a ZrO2 or YSZ nano-film (75 nm), and an Al top electrode (270 nm) are sequentially deposited by sputtering. These RRAM devices exhibit ohmic behaviors in the low-field region, while Schottky and Poole–Frenkel emissions take over in the high-field regions. Both the Schottky and trap barrier levels are decreased when monoclinic ZrO2 is replaced by cubic YSZ in the metal/oxide/metal structure. This is attributed not only to the higher symmetry crystal structure and lower binding energy of YSZ, but also to the formation of more oxygen vacancies and their re-distribution associated with yttria doping.

Yeh, Tsung-Her; Lin, Ruei-De; Cherng, Bo-Ruei; Cherng, Jyh-Shiarn

2015-01-01

64

Industrial residues as an external carbon source in denitrification; Industrielle Reststoffe als externe Kohlenstoffquelle fuer die Denitrifikation  

Energy Technology Data Exchange (ETDEWEB)

Biological waste water treatment requires biologically readily degradable carbon in order to permit elimination of as much nitrogen as possible. Often now this type of carbon is no longer present in waste water in an appropriate quantity, so that external carbon must be added. Apart from industrially fabricated substrates, the use of industrial residues and waste products as well as of partial waste water streams with a high organic pollutant load is lately being considered for cost reasons. But this is not altogether harmless. Those partial streams may contain substances that inhibit denitrification, impose an additional burden on subsequent cleaning stages or may even pass them unmodified, so that they are emitted into the environment and pose an ecological hazard potential. Hence, industrial residual products need to be specifically selected for use as an external carbon source in denitrification. A suitable strategy is described and demonstrated by means of different examples. (orig.) [German] In der biologischen Abwasserbehandlung ist fuer eine weitestgehende Stickstoffelimination oftmals biologisch gut abbaubarer Kohlenstoff im Abwasser nicht (mehr) in ausreichendem Masse vorhanden. Dann ist die Zugabe einer sog. externen Kohlenstoffquelle erforderlich. Neben industriell hergestellten Substraten wird in letzter Zeit aus Kostengruenden vielfach der Einsatz industrieller Rest- und Abfallstoffe sowie organisch hochbelasteter Abwasserteilstroeme erwogen. Dies ist jedoch nicht unproblematisch, da in diesen Stoffstroemen auch Substanzen enthalten sein koennen, die die Denitrifikation hemmen, nachfolgende Reinigungsstufen zusaetzlich belasten oder diese sogar unveraendert passsieren, dadurch in die Umwelt emittiert werden und damit moeglicherweise aus oekologischer Sicht ein Gefahrenpotential darstellen koennen. Es muss also eine besondere Auswahl der Pruefung industrieller Reststoffe im Hinblick auf den Einsatz als externe Kohlenstoffquelle in der Denitrifikation erfolgen. Hierzu wird eine geeignete Strategie vorgestellt und anhand verschiedener Beispiele erlaeutert. (orig.)

Schories, G. [TECON GmbH, Clausthal-Zellerfeld (Germany); Geissen, S.U.; Vogelpohl, A. [Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany). Inst. fuer Thermische Verfahrenstechnik

1999-07-01

65

In service monitoring based on fatigue analyses, possibilities and limitations; Ermuedungsanalysen als Hilfsmittel zur Betriebsueberwachung, Moeglichkeiten und Grenzen  

Energy Technology Data Exchange (ETDEWEB)

German LWR reactors are equipped with monitoring systems which are to enable a comparison of real transients with load case catalogues and fatigue catalogues for fatigue analyses. The information accuracy depends on the accuracy of measurements, on the consideration of parameters influencing fatigue (medium, component surface, component size, etc.), and on the accuracy of the load analyses. The contribution attempts a critical evaluation, also inview of the fact that real fatigue damage often are impossible to quantify on the basis of fatigue analyses at a later stage. The effects of the consideration or non-consideration of various influencing factors are discussed, as well as the consequences of the scatter of material characteristics on which the analyses are based. Possible measures to be taken in operational monitoring are derived. (orig.) [German] In der Bundesrepublik Deutschland ist in allen Leichtwasserreaktoren eine mehr oder weniger aufwendige Betriebsueberwachung installiert, die anhand von betrieblichen Messdaten (Druck, Temperatur, Massenstrom) und unter Einbeziehung lokaler Temperaturmessstellen den Vergleich der tatsaechlich auftretenden Transienten mit den in den Lastfallkatalogen und in den Ermuedungshandbuechern fuer die Ermuedungsanalysen zugrunde gelegten ermoeglichen sollen. Die daraus abgeleiteten Aussagen zum tatsaechlich erreichten Erschoepfungsgrad des ueberwachten Bauteiles haengen wesentlich von der Genauigkeit der Messwerterfassung, der Beruecksichtigung von das Ermuedungsverhalten beeinflussenden Faktoren (Medium, Oberflaechengestaltung, Bauteilgroesse,...) und der Genauigkeit der Beanspruchungsanalyse ab. Der Beitrag hat eine kritische Wertung zum Ziel auch unter dem Gesichtspunkt, dass tatsaechlich aufgetretene Ermuedungsschaeden bei einer Nachbewertung anhand von Ermuedungsanalysen oft nicht verifiziert werden koennen. Dazu wird beispielhaft auf die Auswirkungen der Beruecksichtigung oder Nichtberuecksichtigung verschiedener Einflussfaktoren und die Folgerung aus der Streuung der den Analysen zugrunde liegenden Werkstoffkennwerte eingegangen. Als Folgerung aus Ergebnissen werden moegliche aus diesen Betrachtungen fuer die Betriebsueberwachung abzuleitende Massnahmen diskutiert. (orig.)

Dittmar, S. [TUeV NORD SysTec GmbH und Co. KG, Hamburg (Germany); Binder, F. [TUeV Sued Industrie Service GmbH, Muenchen (Germany)

2004-07-01

66

Fortschritt als Fortschrittsdiskurs  

Directory of Open Access Journals (Sweden)

Full Text Available Zur Erzielung gesellschaftlichen Fortschritts in demokratisch verfassten Gesellschaften soll die Mo?glichkeit am Fortschrittsdiskurs teilnehmen zu ko?nnen fu?r alle Mitglieder der Gesellschaft als selbstversta?ndliche Pra?misse gelten. Fortschritt wird also als Bewusstseinsbildung dem Fortschritt selbst gegenu?ber und als Entscheidungs- und Handlungsfa?higkeit auf individueller und gesellschaftlicher Ebene definiert. Dies setzt entsprechende Maßnahmen zur Befa?higung dazu voraus, die alle Mitglieder der Gesellschaft erfassen. Dabei ist der Bildungsbereich angesprochen, insbesondere der Schulunterricht. Neben dem in der aktuellen blidungspolitischen Debatte forcierten Fokus auf den Aspekt der Kompetenzorientierung, der hier nicht infrage gestellt wird, ist als notwendige Erga?nzung ein reflexionsorientierter Schulunterricht in allen Bildungsfa?chern einzufordern und umzusetzen. Im Weiteren beschreibt der Text den Weg von der Brauchbarkeit zur Bedeutsamkeit von schulischem Wissen durch Relevanzreflexionsprovokationen im Schulunterricht, um Sinn und Bedeutung der vermittelten Bildungsinhalte zu verhandeln. Am Beispiel von Mathematik als Bildungsfach wird der Inhalt von reflexionsorientertem Unterricht verdeutlicht. Daru?ber hinaus beschreibt der Text eine Reihe von konkreten Fallbeispielen aus der aktuell versuchsweise durchgefu?hrten Unterrichtspraxis in Mathematik.

Rainer Schmid-Zartner

2014-12-01

67

Rapidly solidified NiAl and FeAl  

Science.gov (United States)

Melt spinning was used to produce rapidly solidified ribbons of the B2 intermetallics NiAl and FeAl. Both Fe-40Al and Fe-45Al possessed some bend ductility in the as spun condition. The bend ductility of Fe-40Al, Fe-45Al, and equiatomic NiAl increased with subsequent heat treatment. Heat treatment at approximately 0.85 T (sub m) resulted in significant grain growth in equiatomic FeAl and in all the NiAl compositions. Low bend ductility in both FeAl and NiAl generally coincided with intergranular failure, while increased bend ductility was characterized by increasing amounts of transgranular clevage fracture.

Gaydosh, D. J.; Crimp, M. A.

1985-01-01

68

ALS superbend magnet performance  

Energy Technology Data Exchange (ETDEWEB)

The Lawrence Berkeley National Laboratory has been engaged in the design, construction and testing of four superconducting dipoles (Superbends) that are installed in three arcs of the Advanced Light Source (ALS), with the fourth magnet as a spare. This represents a major upgrade to the ALS providing an enhanced flux and brightness at photon energies above 10 keV. In preparation for installation, an extensive set of tests and measurements have been conducted to characterize the magnetic and cryogenic performance of the Superbends and to fiducialize them for accurate placement in the ALS storage ring. The magnets are currently installed, and the storage ring is undergoing final commissioning. This paper will present the results of magnetic and cryogenic testing.

Marks, Steve; Zbasnik, John; Byrne, Warren; Calais, Dennis; Chin, Michael; DeMarco, Richard; Fahmie, Michael; Geyer, Alan; Krupnick, Jim; Ottens, Fred; Paterson, James A.; Pipersky, Paul; Robin, David S.; Schlueter, RossD.; Steier, Christoph; Wandesforde, Alan

2001-12-10

69

Pornographie als Metapher  

Directory of Open Access Journals (Sweden)

Full Text Available In diesem Artikel werden unterschiedliche metaphorische Verwendungen des Pornografiebegriffs und deren Implikationen untersucht. Während die Existenz von Pornografie der feministischen Anti-Porno-Bewegung als Erklärung für die anhaltende Diskriminierung von Frauen in westlichen Gesellschaften dient, nutzen rechtskonservative Kräfte den Pornografievorwurf als Rechtfertigung für die Zensur von als deviant empfundenen Identitäten und sexuellen Praktiken.This article examines different metaphorical uses of the term pornography and the resulting implications. While the existence of pornography for the feminist anti-porno movement serves as factor in the continuing discrimination of women in western societies, conservative powers on the right use the allegation of pornography as a justification for censorship of those identities and sexual practices deemed deviant.

Caroline Schubarth

2010-03-01

70

ALS superbend magnet performance  

International Nuclear Information System (INIS)

The Lawrence Berkeley National Laboratory has been engaged in the design, construction and testing of four superconducting dipoles (Superbends) that are installed in three arcs of the Advanced Light Source (ALS), with the fourth magnet as a spare. This represents a major upgrade to the ALS providing an enhanced flux and brightness at photon energies above 10 keV. In preparation for installation, an extensive set of tests and measurements have been conducted to characterize the magnetic and cryogenic performance of the Superbends and to fiducialize them for accurate placement in the ALS storage ring. The magnets are currently installed, and the storage ring is undergoing final commissioning. This paper will present the results of magnetic and cryogenic testing

71

ALS superbend magnet system  

International Nuclear Information System (INIS)

The Lawrence Berkeley National Laboratory is preparing to upgrade the Advanced Light Source (ALS) with three superconducting dipoles (Superbends). In this paper we present the final magnet system design which incorporates R and D test results and addresses the ALS operational concerns of alignment, availability, and economy. The design incorporates conduction-cooled Nb-Ti windings and HTS current leads, epoxy-glass suspension straps, and a Gifford-McMahon cryocooler to supply steady state refrigeration. We also present the current status of fabrication and testing

72

ALS superbend magnet system  

Energy Technology Data Exchange (ETDEWEB)

The Lawrence Berkeley National Laboratory is preparing to upgrade the Advanced Light Source (ALS) with three superconducting dipoles (Superbends). In this paper we present the final magnet system design which incorporates R&D test results and addresses the ALS operational concerns of alignment, availability, and economy. The design incorporates conduction-cooled Nb-Ti windings and HTS current leads, epoxy-glass suspension straps, and a Gifford-McMahon cryocooler to supply steady state refrigeration. We also present the current status of fabrication and testing.

Zbasnik, J.; Wang, S.T.; Chen, J.Y.; DeVries, G.J.; DeMarco, R.; Fahmie, M.; Geyer, A.; Green, M.A.; Harkins, J.; Henderson, T.; Hinkson, J.; Hoyer, E.H.; Krupnick, J.; Marks, S.; Ottens, F.; Paterson, J.A.; Pipersky, P.; Portmann, G.; Robin, D.A.; Schlueter, R.D.; Steier, C.; Taylor, C.E.; Wahrer, R.

2000-09-15

73

Lou Gehrig's Disease (ALS)  

Science.gov (United States)

... ALS to get around. A machine called a ventilator (say: VEN-ti-lay-ter) can help a someone breathe. In addition, a nurse or other health assistant may come to the person's home to provide care that the family cannot handle ...

74

Ausbildung als zentrale Aufgabe  

Science.gov (United States)

Anders als Lesen und Schreiben zählen Grundkenntnisse in Statistik heute noch nicht zu den Voraussetzungen einer sinnvollen Teilhabe am Sozialgeschehen. Und auch in der akademischen Statistik-Ausbildung gibt es noch einiges zu tun. Das vorliegende Kapitel zeichnet die Geschichte dieser akademischen Ausbildung an deutschen Universitäten nach dem zweiten Weltkrieg nach, stellt aktuelle Defizite vor und weist auf mögliche Verbesserungen hin.

Krämer, Walter; Schmerbach, Sibylle

75

Mercaptursäure und Nukleosidaddukt im Harn als Biomarker in 1-Hydroxymethylpyren-exponierten Ratten  

Science.gov (United States)

1-Methylpyren (MP) ist hepatokanzerogen in neugeborenen männlichen Mäusen. Durch Hydroxylierung an der benzylischen Stelle und anschließende Sulfonierung wird MP zu DNA-reaktivem 1-Sulfooxymethylpyren (SMP) aktiviert. In der Ratte führt die Exposition des benzylischen Alkohols, 1-Hydroxymethylpyren (HMP), zur DNA-Adduktbildung in verschiedenen Geweben. Eventuelle Konsequenz der Toxifizierung ist die Ausscheidung entsprechender Mercaptursäure und Nukleosidaddukt im Harn, welche aufgrund ihrer Herkunft als Biomarker eignen könnten. In dieser Arbeit wird die Ausscheidung der Mercaptursäure und des N2-Desoxyguanosinadduktes in HMP-exponierten Ratten untersucht. Nach der Applikation von HMP bzw. MP wurden weniger als 1 % der Dosis als MPMA über Urin und Faeces ausgeschieden (0 - 48 h). Die Ausscheidung erfolgt hauptsächlich in den ersten 24 h nach der Applikation. MPdG konnte weder in Urin noch in Faeces der HMP-behandelten Tieren identifiziert werden. Nach direkter SMP-Applikation wurde MPdG nur in sehr geringe Menge (weniger als 0,9 ppm in 12 h) im Urin gefunden. Aufgrund der geringen Menge eignet sich MPdG nicht als Biomarker. MPMA dagegen, lässt sich analytisch gut erfassen. Es sollte daher untersucht werden, ob MPMA die Toxifizierung des HMP wiederspiegelt. Die Voraussetzung dafür ist die Kenntnisse über das Metabolismusmuster von HMP. Es wurde daher umfassende Untersuchungen zum Metabolismus des HMP durchgeführt. Die Ergebnisse zeigten, dass mehr als 80 % der Metaboiten in ihrer oxidierten Form (PCS, deren Glucuronsäure-Konjugate sowie phenolische Sulfatester der PCS) ausgeschieden wurden. Demnach spielt die Oxidation des HMP zu PCS eine sehr wichtige Rolle bei der Detoxifizierung und Ausscheidung von HMP. Ferne konnte nachgewiesen werden, dass die Enzyme Alkohol- und Aldehyd-Dehydrogenase an der Oxidation von HMP beteiligt waren. Die Inhibitoren Disulfiram und Ethanol der o. g. Enzyme wurde daher zur Modulation der Detoxifizierung in vivo eingesetzt. Die Veränderungen in der Toxifizierung von HMP zu SMP wurden durch die SMP-Konzentration im Plasma, die DNA-Addukthäufigkeit und die MPMA-Ausscheidung erfasst. Die Vorbehandlung von Disulfiram und Ethanol führte zu tendentielle Erhöhung der SMP-Konzentration im Plasma, DNA-Addukthäufigkeit in der Leber und die MPMA-Ausscheidung. Bemerkenswert ist jedoch, dass bereits eine Dosis von 0,2 g Ethanol/kg Körpermasse bereits zu statistisch signifikanten Erhöhungen der MPMA-Ausscheidung bei weiblichen Ratten. 1-Methylpyrene is hepatocarcinogenic in rodents. It is metabolized primarily to 1-hydroxymethylpyrene (HMP) by various cDNA-expressed rat and human cytochromes P450. HMP is activated to a highly reactive sulfuric acid ester, 1-sulfooxymethylpyrene (SMP), by sulphotransferases. In the rat, this activation pathway leads to the formation of DNA adducts in various tissues. Possible consequences of the toxification could be the excretion of the corresponding mercapturic acid and nucleosidadduct in urine and feces. Because of their origin, these substances should reflex the toxification process may be used as biomarkers. We investigate the excretion of 1-methylpyrenyl-mercapturic acid (MPMA) and the excretion of N2-(1-methylpyrenyl)-desoxyguanosin (MPdG) in urine and feces of HMP-treated rats. These studies showed that only a minor portion ( 30 %). Minor metabolites were phenolic sulpho conjugates of HMP (< 5 %). The glucuronic acid conjugate of HMP was found in very s

Ma, Lan

2002-01-01

76

ALS Project Management Manual  

Energy Technology Data Exchange (ETDEWEB)

This manual has been prepared to help establish a consistent baseline of management practices across all ALS projects. It describes the initial process of planning a project, with a specific focus on the production of a formal project plan. We feel that the primary weakness in ALS project management efforts to date stems from a failure to appreciate the importance of ''up-front'' project planning. In this document, we present a guide (with examples) to preparing the documents necessary to properly plan, monitor, and control a project's activities. While following the manual will certainly not guarantee good project management, failure to address the issues we raise will dramatically reduce the chance of success. Here we define success as meeting the technical goals on schedule and within the prescribed budget.

Krupnick, Jim; Harkins, Joe

2000-05-01

77

ALS insertion devices  

Science.gov (United States)

The Advanced Light Source (ALS), the first US third generation synchrotron radiation source, is currently under construction at the Lawrence Berkeley Laboratory. The low-emittance, 1.5 GeV electron storage ring and the insertion devices are specifically designed to produce high brightness beams in the UV to soft X-Ray range. The planned initial complement of insertion devices includes four 4.6 m long undulators, with period lengths of 3.9 cm, 5.0 cm (2) and 8.0 cm, and a 2.9 m long wiggler of 16 cm period length. Undulator design is well advanced and fabrication has begun on the 5.0 cm and 8.0 cm period length undulators. This paper discusses ALS insertion device requirements; general design philosophy; and design of the magnetic structure, support structure/drive systems, control system and vacuum system.

Hoyer, E.; Chin, J.; Halbach, K.; Hassenzahl, W. V.; Humphries, D.; Kincaid, B.; Lancaster, H.; Plate, D.

1991-08-01

78

ALS insertion devices  

International Nuclear Information System (INIS)

The Advanced Light Source (ALS), the first US third generation synchrotron radiation source, is currently under construction at the Lawrence Berkeley Laboratory. The low-emittance, 1.5 GeV electron storage ring and the insertion devices are specifically designed to produce high brightness beams in the UV to soft X-Ray range. The planned initial complement of insertion devices includes four 4.6 m long undulators, with period lengths of 3.9 cm, 5.0 cm (2) and 8.0 cm, and a 2.9 m long wiggler of 16 cm period length. Undulator design is well advanced and fabrication has begun on the 5.0 cm and 8.0 cm period length undulators. This paper discusses ALS insertion device requirements; general design philosophy; and design of the magnetic structure, support structure/drive systems, control system and vacuum system. 18 refs., 9 figs., 5 tabs

79

/Al-Si Composite  

Science.gov (United States)

The cyclic fatigue characteristics of spray-deposited SiCp/Al-Si composite were investigated in comparison with the unreinforced Al-Si alloy. The as-extruded specimens were cyclically deformed with fully reversed loading under a range of total strain amplitudes. The results show that the cyclic response characteristics for the reinforced and unreinforced materials are similar to each other. Both the composite and matrix alloys display cyclic hardening under total strain amplitude of 0.35-0.5%. Otherwise, the composite exhibits higher degree of strain hardening than that of the matrix alloy. Dislocation substructure developed during cyclic deformation was analyzed using transmission electron microscopy. The discrepancy between dislocation substructures obtained from processing compared to its development during cyclic strain loading is thought to give rise to the observed cyclic stress response behavior. Fractographic analysis shows that particle/matrix debonding and particle cracking are the main mechanisms of failure in the SiC particle-reinforced composite.

Li, Wei; Chen, Jian; Hu, Yongle; Cong, Li; Sun, YouPing; Yang, JiMing

2014-08-01

80

Diffusion of Al during hot consolidation of FeAl  

International Nuclear Information System (INIS)

During the consolidation process of a fine-grained FeAl material local diffusion of Al and C takes place out from the FeAl phase into the encapsulating steel. Al and C transport was studied through recording of concentration profiles, using energy dispersive X-ray analysis with both scanning and transmission electron microscopy, together with microstructural developments and an associated model analysis. The role of processing environment is also discussed. The diffusion coefficient of Al in FeAl is about 10-11 m2/s at 1150 deg. C for the material studied, with grain sizes between 0.5 and 5 ?m. Grain boundaries are concluded to have a large effect on the global diffusion of Al in FeAl, even at the high temperature investigated here

81

„Vertrieben 1938“ – Sonder-Blogserie im Van Swieten Blog der Medizinischen Universität Wien: Work in Progress über die mehr als 143 an der Medizinischen Fakultät der Universität Wien entlassenen Professoren und Dozenten / "Displaced 1938" – a special run in the Van Swieten Blog at the Medical University Vienna: Work in progress about 143+ professors and university teachers displaced from the Medical Faculty at the University Vienna  

Directory of Open Access Journals (Sweden)

Full Text Available Since 11th March 2008 the university library at the Medical University Vienna runs the special blog series "Displaced 1938" as part of its regular Van Swieten Blog (http://ub.meduniwien.ac.at/blog/. Each day one out of 143 displaced professors and university teachers is introduced in a seperate weblog posting. Biographies from a dissertation in the library's repositoy were scanned for this particular purpose. Moreover the corresponding publications from and about the displaced persons in stock of the branch library of the history of medicine were electronically catalogued in the library's OPAC. The postings also refer to pictures and documents in the picture archives and manuscript collection at the Medical University Vienna. Links to appropriate free internet web sites are offered in the postings to further inform on the displaced professors and university teachers.

Bauer, Bruno

2008-06-01

82

Multi-agent communication for the realization of business-processes  

OpenAIRE

Internet und Informationstechnik finden immer mehr Verwendung in alltäglichen Geschäftsaktivitäten und als Folge dessen, werden neue Lösungen und Verfahren gebraucht, um der steigenden Komplexität gerecht zu werden. Insbesondere Bereiche wie System- und Organizations- Interoperabilität, wie auch dienst-orientierte Architekturen (SOA) haben demzufolge mehr Aufmerksamkeit bekommen. Dabei sind Web Services zur bevorzugten Technologie geworden. Tatsächlich haben diese Techniken Probleme in...

Leo?n Soto, Esteban

2013-01-01

83

Mohrrübenpolitik: Zielvereinbarungen zwischen reflexivem Management und fortgeschrittener Erbsenzählung  

OpenAIRE

Zielvereinbarungen finden - der Literaturlage zufolge - rasch zunehmende Verbreitung. Das mag damit erklärt werden, daß sie als Universalwerkzeug betrieblicher Gestaltung dienen können, sich gar zu einem machtvollen Mittel strategischen Managements entwickeln lassen. Einen „Quantensprung zu mehr Leistung“ verspricht etwa Bühner (2000), „mehr Motivation durch Transparenz, bessere Führung durch Controlling, und höhere Leistung durch Fairness.“ Abgesehen von der üblichen Unkenntni...

Moldaschl, Manfred

2007-01-01

84

Interdisziplinäre Rechtsforschung zwischen Rechtswirklichkeit, Rechtsanalyse und Rechtsgestaltung  

OpenAIRE

Die Frage "Wie wirkt Recht?" war das Thema des ersten internationalen wissenschaftlichen Kongresses der deutschsprachigen rechtssoziologischen Fachgesellschaften im September 2008 in Luzern. Über 250 Teilnehmende aus 10 Ländern verfolgten mehr als 160 Referate, welche eine ungeahnte Lebendigkeit der inter- und transdisziplinären Rechtsforschung dokumentierten, einem Fachgebiet, welches in den vergangenen 30 Jahren kaum mehr öffentliche Resonanz fand. Die einzelnen Fachrichtungen wie etwa ...

2009-01-01

85

Pilot-scale process development for the purification of the recombinant antibody 2G12 from transgenic tobacco  

OpenAIRE

Die Produktion von rekombinanten therapeutischen Proteinen erfährt ein mehr und mehr steigendes Interesse. Dies kommt sowohl durch den ansteigenden Bedarf als auch durch das Erreichen einer Produktionskapazität von rekombinanten Therapeutika. Transgene Pflanzen bilden hier ein ergänzendes Produktionssystem zur den bereits etablierten Produktionsplattformen. Die Etablierung einer neuen Plattform erfordert allerdings die Entwicklung eines Aufreinigungsprozesses, der von der Produktionspflanz...

Lobedann, Martin

2009-01-01

86

Schizophrenia as a disconnection syndrome. Studies with functional magnetic resonance imaging and structural equation modeling; Schizophrenie als Diskonnektionssyndrom. Studien mit funktioneller Magnetresonanztomographie und Strukturgleichungsmodellen  

Energy Technology Data Exchange (ETDEWEB)

Aside from characteristic psychopathological symptoms, cognitive deficits are a core feature of schizophrenia. These deficits can only be addressed within the context of widespread functional interactions among different brain areas. To examine these interactions, structural equation modeling (SEM) was used for the analysis of fMRI datasets. In a series of studies, both in antipsychotic-treated and drug-free schizophrenic patients, a pattern of enhanced thalamocortical functional connectivity could be observed as an indicator for possible disruptions of frontostriatal thalamocortical circuitry. Moreover, drug-free patients and those receiving typical antipsychotic drugs were characterized by reduced interhemispheric corticocortical connectivity. This difference relative to normal controls was less in patients under atypical antipsychotic drugs. The results could be interpreted as a beneficial effect of atypical antipsychotic drugs on information processing in schizophrenic patients. The present findings are consistent with the model of schizophrenia as a disconnection syndrome and earlier concepts of ''cognitive dysmetria'' in schizophrenia. (orig.) [German] Neben der charakteristischen psychopathologischen Symptomatik stellen kognitive Defizite ein zentrales Merkmal der Schizophrenie dar. Diese Defizite koennen nur im Kontext miteinander interagierender Hirnareale verstanden werden. Zur Untersuchung dieser funktionellen Wechselbeziehungen wurden Strukturgleichungsmodelle (''structural equation modeling'', SEM) zur Auswertung von fMRT-Datensaetzen verwendet. In einer Untersuchungsreihe bei schizophrenen Patienten ergab sich sowohl bei antipsychotisch behandelten als auch bei unbehandelten Patienten ein Muster gesteigerter thalamokortikaler funktioneller Konnektivitaet als Hinweis auf eine moegliche Stoerung fronto-striato-thalamo-kortikaler Regelkreise. Unbehandelte Patienten und Patienten unter typischen Antipsychotika zeichneten sich zudem durch eine reduzierte interhemisphaerische kortikokortikale Konnektivitaet aus. Dieser Unterschied zu den Gesunden war bei den Patienten unter atypischen Antipsychotika nicht mehr in dieser Auspraegung zu beobachten, was als Ausdruck einer moeglichen positiven Beeinflussung der Informationsverarbeitung bei Patienten unter Atypika interpretiert werden koennte. Die erhaltenen Ergebnisse sind konsistent mit dem Modell der Schizophrenie als einem Diskonnektionssyndrom und frueheren Konzeptionen einer ''kognitiven Dysmetrie'' als Grundlage kognitiver Defizite bei dieser Erkrankung. (orig.)

Schloesser, R. [Universitaet Jena, Psychiatrische Klinik (Germany); Universitaet Jena, Psychiatrische Klinik, Jena (Germany); Wagner, G.; Koehler, S.; Sauer, H. [Universitaet Jena, Psychiatrische Klinik (Germany)

2005-02-01

87

Optical gain characteristics in Al-rich AlGaN/AlN quantum wells  

Energy Technology Data Exchange (ETDEWEB)

The optical gain characteristics of Al-rich AlGaN/AlN quantum wells (QWs) were assessed by the variable stripe length method at room temperature. An Al{sub 0.79}Ga{sub 0.21}N/AlN QW with a well width of 5?nm had a large optical gain of 140?cm{sup ?1}. Increasing the excitation length induced a redshift due to the gain consumption and the consequent saturation of the amplified spontaneous emission. Moreover, a change in the dominant gain polarization with Al composition, which was attributed to switching of the valence band ordering of strained AlGaN/AlN QWs at Al compositions of ?0.8, was experimentally demonstrated.

Oto, Takao; Banal, Ryan G.; Funato, Mitsuru; Kawakami, Yoichi, E-mail: kawakami@kuee.kyoto-u.ac.jp [Department of Electronic Science and Engineering, Kyoto University, Kyoto 615-8510 (Japan)

2014-05-05

88

Optical gain characteristics in Al-rich AlGaN/AlN quantum wells  

International Nuclear Information System (INIS)

The optical gain characteristics of Al-rich AlGaN/AlN quantum wells (QWs) were assessed by the variable stripe length method at room temperature. An Al0.79Ga0.21N/AlN QW with a well width of 5?nm had a large optical gain of 140?cm?1. Increasing the excitation length induced a redshift due to the gain consumption and the consequent saturation of the amplified spontaneous emission. Moreover, a change in the dominant gain polarization with Al composition, which was attributed to switching of the valence band ordering of strained AlGaN/AlN QWs at Al compositions of ?0.8, was experimentally demonstrated

89

Atención al paciente crítico  

Directory of Open Access Journals (Sweden)

Full Text Available

El presente artículo resume la experiencia docente-investigativa sobre la atención al paciente crítico, desde un enfoque que describe problemas inherentes a los sistemas cardiovasculares, respiratorio y neurológico, considerados sistemas vitales del ser humano. Se pretende describir una serie de metas, que orientan la intervención del profesional de enfermería y sustentan la planeación, ejecución, control y evaluación de intervenciones específicas, encaminadas a detectar oportunamente las complicaciones o tratar problemas complejos en el grupo de pacientes críticamente enfermos.

Parra Vargas Myriam

1993-08-01

90

Huerta al alba  

Scientific Electronic Library Online (English)

Full Text Available Efraín Huerta nació en Silao, Guanajuato, en 1914, y murió en el D. F. en 1982. En este año 2014, se cumplen setenta años de la aparición de Los hombres del alba. Si la generación Contemporáneos marca el antes y el después de la poesía mexicana actual, Huerta, con la edición de su libro en 1944, es [...] un referente obligado si se pretende llegar al lugar de donde es oriunda la poesía moderna y contemporánea mexicana. A partir del contexto ideológico que le toca vivir al poeta guanajuatense en la capital, que dejó huella profunda en sus primeros libros, se pone en relieve el giro de 180 grados que, después de aquella primera etapa, dieron los poemas que constituyen Los hombres del alba a la poesía mexicana. Abstract in english Efraín Huerta was born in Silao, Guanajuato, México, in 1914. He died in Mexico City in 1982. This year (2014) is the 70th anniversary of the apparition of Los hombres del alba. If the Contemporáneos generation marks a before and after of the current Mexican poetry, then Huerta, with the publication [...] of his book in 1944, is a obligatory point of reference in order to arrive to where modern and contemporary Mexican poetry hails. The ideological context, in which this poet lived in the capital city, marked his first books. Moreover, it is emphasized the 180 degrees turn that, after this first stage, the poems that constitute Los hombres del alba gave to Mexican poetry.

Carlomagno, Sol Tlachi.

2014-12-01

91

Derivados vinculados al seguro.  

Directory of Open Access Journals (Sweden)

Full Text Available El presente trabajo tiene como objetivo la presentación de los derivados financieros como instrumentos de cobertura de los riesgos del seguro, así como de los principales proyectos que se desarrollan a través de los mismos, como por ejemplo los derivados sobre el clima. Hay que tener presente las pérdidas multimillonarias ocasionadas en casos como el de la banca Baring’s, o el de Orange County, por citar algunas, que si bien ciertos autores afirman que están en relación directa con el uso de estos productos, no podemos olvidar que los instrumentos derivados se desarrollaron con el objetivo principal de proteger al usuario de la posible volatilidad del activo subyacente. Ya en la industria aseguradora los derivados vinculados a tal actividad son instrumentos donde el pago se condiciona a la ocurrencia de su suceso de siniestro, o serie de sucesos múltiples que disparen las pérdidas. Tras el repaso efectuado y la descripción que este tipo de instrumentos puede tener en la gestión del riesgo por parte de la industria aseguradora, concluiremos con la exposición de las relaciones con el reaseguro tradicional así como una breve referencia al futuro de este tipo de instrumentos

De Paz Cobo, Sonia

2003-01-01

92

"Mediman" – Smartphone als Plattform zum Lernen? ["Mediman" – The smartphone as a learning platform?  

Directory of Open Access Journals (Sweden)

Full Text Available [english] Mobile devices with a connection to the internet – smartphones – are seen all over the place since the popular introduction of the Apple iPhone. Similar products existed but no company managed to combine simplicity and functionality so seamlesly. Their market share increases constantly and web sites get optimised for the small display sizes (often referred to as „responsive webdesign“ otherwise the usability lacks. Students seem to like smartphones aswell and a good question is if and to what extend those devices can play a role in e-learning.„Mediman“, an adaptation of the common game Hangman has been developed for smartphones. Test users asked to complete an online questionnaire. So far, only few e-learning applications for smartphones seem to exist. This is reflected in the low usage frequency. Especially the fact that most of the test users wear a smartphone with them all the time makes it an ideal learning plattform. Short learning sessions were rated more important than continuous text. The majority of the 11 test users rated Mediman as well developed. The foremost question whether a smartphone e-learning application is feasible must be answered positive – acceptance in the test user group was shown. E-learning applications on smartphones will be an important topic in the future as market shares increase constantly. Further studies are required due to the small number of partitipants in our survey. [german] Mobile Endgeräte mit Internetzugang (Smartphones sind seit Apples revolutionärer iPhone-Markteinführung nicht mehr aus dem Alltag wegzudenken und erfreuen sich ausgesprochener Beliebtheit. Ihr Marktanteil wächst stetig und Webseitenbetreiber kommen nicht umher, ihre Webseiten an die neuen kleinen Displaygrößen und Bedienungstechniken anzupassen – häufig als „Responsive Webdesign“ beschrieben. Anwendungen, die nicht für die Anzeige auf kleinen Bildschirmen optimiert sind, schränken den Bedienkomfort ein. Auch bei Studierenden sind Smartphones sehr verbreitet und so stellt sich die Frage, ob sie nicht auch als Plattform für Lernanwendungen dienen können.„Mediman“, eine Portierung des klassischen Spielprinzips von Galgenmännchen, wurde für Smartphones entwickelt. Testbenutzer wurden dann gebeten, einen Onlinefragebogen auszufüllen. Zur Zeit scheinen nur wenige Lernanwendungen für Smartphones zu existieren, was sich in der eingeschränkten Benutzungshäufigkeit widerspiegelt. Vor allem die Tatsache, dass Smartphone-Besitzer ihre Geräte meist bei sich tragen, wird als ideale Voraussetzung gesehen, die Geräte für Lernanwendungen einzusetzen. Hier scheint vor allem das Lernen in kurzen Sitzungen von Interesse. Mediman wurde von der Mehrzahl der 11 Testbenutzer als gut umgesetzte Beispielanwendung bewertet. Die zentrale Frage der Umsetzbarkeit einer Smartphone-Lernanwendung wurde damit erreicht – die notwendige Akzeptanz scheint vorhanden.Für die Zukunft ist mit einer zunehmenden Verbreitung von Smartphones zu rechnen, sodass Lernanwendungen und –szenarien für Endgeräte mit kleinen Bildschirmen optimiert werden sollten. Aufgrund der geringen Fallzahl in der Onlineumfrage sollten weitere Untersuchungen angeschlossen werden.

Boeder, Niklas

2013-02-01

93

Editorial: Cartas al Editor  

Directory of Open Access Journals (Sweden)

Full Text Available En todas las revistas biomédicas del mundo existe una sección habitual denominada como el título de este editorial y que en Colombia Médica la llamamos correspondencia. Este espacio tiene como objetivo fundamental que los lectores escriban a los autores (investigadores comentando los artículos que se han publicado en números anteriores de la revista. Las cartas son, entonces, breves comentarios de desacuerdo o acuerdo (conceptual, metodológico, interpretativo sobre falencias ubicadas por un lector alerta al tema debatido en cualquiera de las secciones como en los artículos originales, editoriales, revisiones, presentación de casos, etc. publicados previamente en la revista. Las cartas deben permitir el intercambio de opiniones y formas de pensar y analizar los problemas planteados entre los autores y los lectores. En ocasiones una serie de cartas motivadas por un artículo original puede ser tan o más interesante como el artículo que generó la correspondencia. Las cartas son también un formato adecuado para comunicar un hecho novedoso de una observación clínica juiciosa no descrita antes. Un ejemplo de ello es la carta de un gineco-obstetra australiano cuando informó a Lancet los primeros efectos adversos informados de la talidomida. Colombia Médica, a pesar de mantener vigente esta sección, no ha sido muy afortunada en establecer una buena cultura del envío de cartas al editor. Pero últimamente han llegado juiciosas observaciones a las cuales se les ha dado prioridad en su publicación. Toda carta que comenta los hallazgos de un artículo es enviada a los autores para su respuesta, porque ello genera el debate académico buscado, y luego se publican, tanto la carta como su respuesta. El Estilo Vancouver recomienda que la carta y su respuesta deban ser breve, no pasar de dos o tres párrafos y contener sólo cuatro o cinco referencias. En lo posible (a menos que sea indispensable no presentar ni cuadros ni gráficos. El título de la carta debe ser informativo, innovativo y obviamente relacionado con el tema a presentar. La carta debe referirse en forma clara y explícita al hecho que la motiva y a partir de ahí seguir un esquema expositivo progresivo. Los párrafos siguientes deben ser la argumentación a favor o en contra, o los comentarios adicionales que se quieren hacer. Luego debe seguir una pequeña discusión de estos aportes y se debe finalizar con una conclusión. Las cartas son finalmente una indicador bibliométrico de la lectura juiciosa de quienes leen la revista. Por ello los editores buscamos y facilitamos el envío de ellas. En Colombia Médica queremos estimular que nos escriban y ojalá nuestros lectores se vuelvan socios muy activos en el proceso de comunicación científica y para ello utilicen nuestra sección de correspondencia.

Guillermo Llanos

2006-06-01

94

Cd-Sb-Al system  

International Nuclear Information System (INIS)

The methods of differential-thermal, microstructural analyses and measuring microhardness are used to investigate the phase diagrams of polythermal sections CdSb-AlSb, CdSb-Al, Cd-AlSb, Cdsub(0.5)Alsub(0.5)-Sb, CdSb-Alsub(0.2)Cdsub(0.8) of the ternary system Cd-Sb-Al. The liquidus projection of the Cd-Sb-Al system is plotted; it has been found that the surface of aluminium antimonide formation occupies a large part of the phase diagram in the field of which the lamination region is located

95

Corrosion behaviour of Al/SiC and Al/Al2O3 nanocomposites  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english In the present investigation, the static immersion corrosion behavior of Al/Al2O3 and Al/SiC nanocomposites in 1 M HCl acidic solution was evaluated. The nanocomposites were fabricated using conventional powder metallurgy (P/M) route. The effect of nanoparticulates size and volume fraction on the co [...] rrosion behavior of nanocomposites was studied. The durations of the corrosion tests ranged from 24 to 120 hours and the temperatures of the solution ranged from ambient to 75 ºC. The corrosion rates of the nanocomposites were calculated using the weight loss method. The results showed that both Al/SiC and Al/Al2O3 MMNCs have lower corrosion rates than the pure Al matrix. Such behavior was noticed at both ambient and higher temperatures. Generally, the Al/Al2O3 nanocomposites exhibited lower corrosion rates than the Al/SiC nanocomposites. The Al/Al2O3 (60 nm) nanocomposites exhibited the highest corrosion resistance among all the investigated nanocomposites. The corrosion rate was found to be reduced by increasing of the exposure time and the volume fraction of the nanoparticulates, while it was found to be increased by increasing of the nanoparticulates size and the solution temperature.

Tamer Samir, Mahmoud; El-Sayed Yousef, El-Kady; Ayed Saad Merzen, Al-Shihiri.

2012-12-01

96

Corrosion behaviour of Al/SiC and Al/Al2O3 nanocomposites  

Directory of Open Access Journals (Sweden)

Full Text Available In the present investigation, the static immersion corrosion behavior of Al/Al2O3 and Al/SiC nanocomposites in 1 M HCl acidic solution was evaluated. The nanocomposites were fabricated using conventional powder metallurgy (P/M route. The effect of nanoparticulates size and volume fraction on the corrosion behavior of nanocomposites was studied. The durations of the corrosion tests ranged from 24 to 120 hours and the temperatures of the solution ranged from ambient to 75 ºC. The corrosion rates of the nanocomposites were calculated using the weight loss method. The results showed that both Al/SiC and Al/Al2O3 MMNCs have lower corrosion rates than the pure Al matrix. Such behavior was noticed at both ambient and higher temperatures. Generally, the Al/Al2O3 nanocomposites exhibited lower corrosion rates than the Al/SiC nanocomposites. The Al/Al2O3 (60 nm nanocomposites exhibited the highest corrosion resistance among all the investigated nanocomposites. The corrosion rate was found to be reduced by increasing of the exposure time and the volume fraction of the nanoparticulates, while it was found to be increased by increasing of the nanoparticulates size and the solution temperature.

Tamer Samir Mahmoud

2012-12-01

97

ALS Performance Summary - Update  

Energy Technology Data Exchange (ETDEWEB)

High Energy Density Physics (HEDP) experiments play an important role in corroborating the improved physics codes that underlie LLNL's Stockpile Stewardship mission. Conducting these experiments, whether on the National Ignition Facility (NIF) or another national facility such as Omega, will require not only improvement in the diagnostics for measuring the experiment, but also detailed knowledge of the as-built target components and assemblies themselves. To assist in this effort, a defined set of well-known reference standards designed to represent a range of HEDP targets have been built and are being used to quantify the performance of different characterization techniques [Hibbard, et al. 2004]. Without the critical step of using reference standards for qualifying characterization tools there can be no verification of either commercial or internally-developed characterization techniques and thus an uncertainty in the input to the physics code models would exist.

Waters, A M; Brown, W D; Martz, Jr., H E

2004-09-30

98

Oxidation of Al(111)  

Science.gov (United States)

The oxidation of Al(111) has been studied with a wide range of experimental and theoretical tools. Despite this attention it has only been with the use of MEIS that it has been possible to establish that at oxygen exposures of up to 100 L there is no detectable subsurface oxygen. The oxygen concentration increases smoothly with exposure up to 200 L and furthermore it has been found that oxidation induces an enhanced aluminium atom yield in the surface peak. The location of the surface adsorption site was not possible with normal methods of blocking and shadowing, however the site has been determined with the use of an energy-modulation method. This has identified the most probable site to be a C site.

O'Connor, D. J.; Wouters, E. R.; van der Gon, A. W. Denier; Vrijmoeth, J.; Zagwijn, P. M.; Slijkerman, W. F. J.; Frenken, J. W. M.; van der Veen, J. F.

1993-05-01

99

Epitaxial growth of Al/Al2O3 multilayer structures  

International Nuclear Information System (INIS)

In order to obtain Al-Al2O3 quantum effect devices, it is necessary to deposit epitaxially Al on Al2O3 and Al2O3 on Al. We have already obtained an epitaxial Al/Al2O3/Al structures on Si(111). In this paper, we have deposit Al/Al2O3/Al structures on Si(111), and investigated the crystallinity by using RBS. (author)

100

The hydrogen economy. When there is no more oil. The creation of the worldwide energy web and the redistribution of power on earth; Die H{sub 2}-Revolution. Wenn es kein Oel mehr gibt. Mit neuer Energie fuer eine gerechte Weltwirtschaft  

Energy Technology Data Exchange (ETDEWEB)

The author explains that the next great economic era will be powered by hydrogen. Drawing on a variety of well-balanced research studies, his premise is that the world must switch from a fossil-fuel economy to a hydrogen based economy. This must happen soon for three reasons: the imminent peak of global oil production, the increased concentration of remaining oil reserves in the Middle East one of the most politically and socially unstable regions of the world and the steady heating up of the world atmosphere from fossil-fuel dependency. This revolution will make energy available to each country, not just the wealthiest nations, and would be the first democratic energy regime in history. [German] Das Zeitalter der fossilen Brennstoffe (Kohlenwasserstoffzeitalter) ist an einem kritischen Punkt angelangt. In dem Buch von Jeremy Rifkin beweisen nach einem kurzen Abriss der Energiegeschichte akribisch angefuehrte umfangreiche Statistiken, dass das Erdoel und Erdgas spaetestens 2010 spuerbar knapp sein wird. Die wenigen verbliebenen Erdoelreserven liegen ausserdem ueberwiegend in politisch instabilen Gebieten. Bei steigender Oelknappheit treiben die alternativ verwendeten anderen fossilen Energiequellen die globale Erwaermung voran und gefaehrden das Oekosystem der Erde. Jeremy Rifkin sieht den einzigen Ausweg in einer neuen, auf Wasserstoff basierenden Weltwirtschaft. Die ''Dekarbonisierung'' der Energie, die unvermeidlich zur Wasserstoffzukunft fuehren wird, ist abzusehen. Wasserstoff wird eine basisdemokratische, nachhaltige Energie- und Brennstoffquelle der Zukunft, unabhaengig von Oelimporten. Brennstoffzellen auf Wasserstoffbasis koennen den Energiebedarf der gesamten Menschheit ueber einen sehr langen Zeitraum decken. Die realisierung einer neuen dezentralen Form der Energienutzung und demokratischen Energiekontrolle durch Millionen von Verbrauchern (lokalen Kleinstkraftwerken mit Brennstoffzellen), angeschlossen an ein weltweites Wasserstoffenergienetz, um damit Energie untereinander tauschen zu koennen und mit Ueberschuessen handeln zu koennen, wird eine demokratische Reglobalisierung von unten bedeuten. Die Zeit der wenigen grossen Energiekonzerne wird von einer Epoche vieler kleiner, unabhaengiger Versorger abgeloest. Oekonomische, soziale und und oekologische Netzwerke werden entstehen als Teil eines gesamtweltlichen Organismus und ein neues Sicherheits- und Unabhaengigkeitsgefuehl aller Buerger hervorrufen. Die eindeutigen Vorteile von Wasserstoff bestehen darin, dass Wasserstoff ueberall existiert, unbegrenzt verfuegbar ist und keine schaedlichen Kohlendioxidemissionen produziert. Diese Energie wird auch erschwinglich fuer Laender, die heute keinen Zugang zu Energie und Wohlstand haben. Ja gerade die Entwicklungslaender koennten den ersten Schritt in die nachhaltige Wasserstoffnutzung machen mit Sonnenenergie als Katalysator. Die ersten Brennstoffzellen auf Waserstoff-Basis werden bereits vielseitig eingesetzt, jedoch ist die Wasserstofferzeugung immer noch teuer und der meiste Wasserstoff wird aus Erdgas und anderen fossilen Brennstoffen gewonnen. In absehbarer Zeit koennte Wasserstoff mit erneuerbaren Energien produziert und billiger werden. Selbst in den Vorstandsetagen fuehrender Energieunternehmen sowie bei politischen Entscheidungstraegern erfreut sich Jules Vernes Vision von einer Zukunft im Zeichen des Wasserstoffs grosser Aufmerksamkeit und sie bemuehen sich auch schon jetzt um.

Rifkin, J.

2002-07-01

101

Beta decays of 25Na, 25Al and 29Al  

International Nuclear Information System (INIS)

The radioactivities 25Na, 25Al, and 29Al were produced in the 23Na(t,p)25Na, 24Mg(d,n)25Al, and 27Al(t,p)29Al reactions using a 3.5 MV Van de Graaff. ?-radiations were measured by means of a target-transfer system and a Ge(Li) detector with or without Compton suppression. Decay schemes derived for 25Na and 29Al are in general agreement with earlier results, but with improved accuracy of branching ratios and much sharper limits on the intensities of certain unobserved ?- and ?-ray transitions. Precision measurements of the energies of principal ?-rays gave results in keV for the listed decaying bodies as follows: 25Na - 1611.716(11); 25Al - 1611.708(11); and 29Al - 1273.361(9). The energy determinations of the 25Mg 1612 keV ?-transition measured in the decay of 25Na and 25Al differ by 8 +- 9 eV. (orig.)

102

Half life of 26Al  

International Nuclear Information System (INIS)

The half-life of 26Al has been redetermined because of suggestions of an error in the accepted value based on its use in calculating 21Ne production rates from cosmic rays in meteorites. Two solutions of 26Al were analyzed for the specific radioactivity and mass spectrometric determination of the 26Al concentration. The half-life obtained for 26Al was 7.05 x 105 years +- 3.7% at the two sigma level. This is identical to the accepted value of 7.16 x 105 years and indicates that problems with the 21Ne production rate is not due to an erroneous half-life

103

On the cathodic dissolution of Al and Al alloys  

International Nuclear Information System (INIS)

Highlights: • The cathodic dissolution of pure Al and AA6061 aluminum alloy is measured. • Cathodic dissolution of Al occurs with a stoichiometry of 4.62 ± 0.22 OH?/Al3+ over several orders of magnitude of cathodic current. • Cathodic dissolution of SiO2 observed at high cathodic current. • Mg2+ species precipitated on the surface perhaps in the form of MgSiO3. • Aln[Fem,Mn1?m]Si phases serve as local cathodes forming “trenches” around the intermetallic particles. - Abstract: The cathodic dissolution of aluminum and aluminum alloys is a potentially important but poorly understood phenomenon. In this work, the dissolution of pure Al and AA6061 aluminum alloy under cathodic polarizations was investigated. The dissolution rates of the base metal and minor alloying elements were measured in real time using atomic emission spectroelectrochemistry. These data were used to verify the stoichiometry of 4.62 ± 0.22 hydroxides per dissolved Al ion for pure Al. It was found that at high cathodic currents, the cathodic dissolution of SiO2 was observed while Mg2+ species precipitated on the surface perhaps in the form of MgSiO3. These precipitated solid phases did not alter the OH/Al stoichiometry. The Aln[Fem,Mn1?m]Si phases appear to serve as local cathodes accelerating Al dissolution leading to the formation of “trenches” around the intermetallic particles

104

Al versus Si competition in FeSiAl alloys  

Energy Technology Data Exchange (ETDEWEB)

In FeSiAl alloys, when Si substitutes for Al, important changes take place in the magnetism as well as in the structural properties. Alloys in the two composition series Fe{sub 75}Al{sub 25-x}Si{sub x} (x=0, 7.5, 12.5, 17.5, 25) and Fe{sub 70}Al{sub 30-x}Si{sub x} (x=0, 9, 15, 21, 30) were prepared by induction melting; afterwards they were crushed and then annealed in order to recover the DO{sub 3} stable phase. The deformed FeAl samples show larger lattice parameters than the ordered ones; however, this difference ({delta}a) decreases when Si substitutes for Al until it becomes zero (i.e. until the ordered samples and the deformed ones have the same lattice parameters). This trend is the same for both sample series and does not depend on the Fe content of the alloy. However, the magnetization has a different behaviour depending on the Fe content. For deformed Fe{sub 75}Al{sub 25-x}Si{sub x} alloys the saturation magnetization decreases with increasing Si content while for Fe{sub 70}Al{sub 30-x}Si{sub x} deformed alloys the saturation magnetization has a plateau in which the saturation magnetization values do not vary.

Legarra, E. [Dpto. Electricidad y Electronica, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco (UPV/EHU), CP 644, 48080 Bilbao (Spain)], E-mail: estibaliz.legarra@ehu.es; Apinaniz, E. [Dpto. Fisica Aplicada I, Escuela de Ingenieria Tecnica Superior, Universidad del Pais Vasco, Alameda de Urquijo s/n 48013 Bilbao (Spain); Plazaola, F. [Dpto. Electricidad y Electronica, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco (UPV/EHU), CP 644, 48080 Bilbao (Spain); Jimenez, J.A. [Centro Nacional de Investigaciones Metalurgicas (CENIM), Avda. Gregorio del amo 8, 28040 Madrid (Spain); Pierna, A.R. [Chemical Engineering and Environmental Department, UPV/EHU, Box 1379, 20008 San Sebastian (Spain)

2008-10-15

105

Al versus Si competition in FeSiAl alloys  

International Nuclear Information System (INIS)

In FeSiAl alloys, when Si substitutes for Al, important changes take place in the magnetism as well as in the structural properties. Alloys in the two composition series Fe75Al25-xSix (x=0, 7.5, 12.5, 17.5, 25) and Fe70Al30-xSix (x=0, 9, 15, 21, 30) were prepared by induction melting; afterwards they were crushed and then annealed in order to recover the DO3 stable phase. The deformed FeAl samples show larger lattice parameters than the ordered ones; however, this difference (?a) decreases when Si substitutes for Al until it becomes zero (i.e. until the ordered samples and the deformed ones have the same lattice parameters). This trend is the same for both sample series and does not depend on the Fe content of the alloy. However, the magnetization has a different behaviour depending on the Fe content. For deformed Fe75Al25-xSix alloys the saturation magnetization decreases with increasing Si content while for Fe70Al30-xSix deformed alloys the saturation magnetization has a plateau in which the saturation magnetization values do not vary

106

Alexandria (Al Iskandariya), Egypt  

Science.gov (United States)

This image of Alexandria was taken by astronauts on board the International Space Station in December 2000 using an Electronic Still Camera. A wider-angle view (STS088-739-90) taken from the Space Shuttle in December 1998 is available for context. Alexandria (Al Iskandariya) occupies a T-shaped peninsula and strip of land separating the Mediterranean from Lake Mariout. Originally the town was built upon a mole (stone breakwater) called Heptastadium, which joined the island of Pharos (see referenced website, below) to the mainland. Since then sedimentary deposits have widened the mole. Since 1905, when the 370,000 Alexandrians lived in an area of about 4 sq km between the two harbors, the city (population 4 million; see referenced website, below) has grown beyond its medieval walls and now occupies an area of about 300 sq km. The Mahmudiya Canal, connecting Alexandria with the Nile, runs to the south of the city and, by a series of locks, enters the harbor of the principal port of Egypt (note ships). The reddish and ochre polygons west of Lake Mariout are salt-evaporation, chemical-storage, and water-treatment ponds within the coastal lagoon. Reference Youssef Halim and Fatma Abou Shouk, 2000, Human impacts on Alexandria's marine environment: UNESCO, Coastal Regions and Small Islands Unit (CSI), Coastal Management Sourcebooks 2 (accessed December 20, 2000) Additional photographs taken by astronauts can be viewed at NASA-JSC's Gateway to Astronaut Photography of Earth. Image ISS001-ESC-5025 provided by the Earth Sciences and Image Analysis Laboratory, Johnson Space Center.

2002-01-01

107

Undulators at the ALS  

International Nuclear Information System (INIS)

At Lawrence Berkeley Laboratory's (LBL) Advanced Light Source (ALS), three 4.6 m long undulators have been completed, tested and installed. A fourth is under construction. The completed undulators include two 5.0 cm period length, 89 period devices (U5.0s) which achieve a 0.85 T effective field at a 14 mm minimum gap and a 8.0 cm period length, 55 period device (U8.0) that reaches a 1.2 T effective field at a 14 mm minimum gap. The undulator under construction is a 10.0 cm period length, 43 period device (U10.0) that is designed to achieve 0.98 T at a 23 mm gap. Undulator magnetic gap variation (rms) is within 25 microns over the periodic structure length. Reproducibility of the adjustable magnetic gap has been measured to be within +/- 5 microns. Gap adjusting range is from 14 mm to 210 mm, which can be scanned in one minute. The 5.1 m long vacuum chambers are flat in the vertical direction to within 0.74 mm and straight in the horizontal direction to within 0.08 mm over the 4.6 m magnetic structure sections. Vacuum chamber base pressures after UHV beam conditioning are. in the mid 10-11 Torr range and storage ring operating pressures with full current are in the low 10-10 Torr range. Measurements show that the uncorrelated magnetic field errors are 0.23%, and 0.20% for the two U5.Os and the U8.0 respectively and that the field integrals are small over the 1 cm by 6 cm beam aperture. Device description, fabrication, and measurements are presented

108

Fabrication of Nb/AlOx/Al/AlOx/Nb junctions for voltage standard applications  

International Nuclear Information System (INIS)

We present an overdamped superconductor-insulator-normal-insulator-superconductor (SINIS) junction technology for ac voltage standard applications. Modifying our standard Nb-junction process, we developed a simple process for Nb/AlOx/Al/AlOx/Nb-junction circuits. A Josephson arbitrary waveform synthesizer device which consisted of a 100-SINIS-junction array embedded in a 50 ? coplanar waveguide was fabricated and successfully tested

109

Ceramic high temperature proton conductors as a membrane concept for oxidative coupling of methane; Keramische Hochtemperatur-Protonenleiter als Membrankonzept fuer die oxidative Kopplung von Methan  

Energy Technology Data Exchange (ETDEWEB)

Research activitites in the field of oxidative methane coupling during the past five years indicate a trend towards new reactor concepts. Ten years of intensive research worldwide have shown that a significant increase of the C{sub 2} yield cannot be achieved by improved catalysts alone. The key issue of all concepts is a suitable combination of reaction and separation. There are various suggestions: Cyclic reaction control (riser/regenerator principle) for a two-stage process; a combination of reaction and product separation by means of adsorption (chromatographic reactor), or local separation of the reaction partners by means of membranes. Ceramic solid electrolytes are the most promising type of membrane. In contrast to oxide ion conductors, comparatively little is known about ceramic high-temperature proton conductors. The best known of these is SrCe{sub 0}.95Yb{sub 0}.05O{sub 3}/x (SCYO). Although CHIANG et al. were able to produce small amounts of C{sub 2} hydrocarbons from methane with pelleted SCYO membranes and Ag electrodes, they were only able to do so with 100% C{sub 2} selectivity, i.e. without formation of total oxidation products. [Deutsch] Die Forschungsaktivitaeten auf dem Gebiet der oxidativen Methankopplung waehrend der vergangenen fuenf Jahre zeigen einen Trend zu neuen Reaktorkonzepten, nachdem zehn Jahre weltweiter intensiver Anstrengungen deutlich gemacht haben, dass eine signifikante Steigerung der C{sub 2}-Ausbeute allein durch Katalysatorverbesserungen nicht mehr zu erwarten ist. Kernpunkt all dieser Konzepte ist eine geeignete Kombination von Reaktion und Stofftrennung. Neben der zeitlichen Trennung der Reaktionsschritte durch zyklische Reaktionsfuehrung (Riser/Regenerator-Prinzip) und der Kombination von Reaktion und Produktabtrennung durch Absorption (chromatographischer Reaktor) wird auch eine oertliche Trennung der Reaktionspartner mit Hilfe von Membranen vorgeschlagen. Keramische Festkoerperelektrolyten stellen dabei den aussichtsreichsten Membrantyp dar. Im Gegensatz zu Oxidionenleitern sind keramische Hochtemperatur-Protonenleiter noch verhaeltnismaessig wenig erforscht. Der bekannteste Vertreter dieser Stoffklasse ist SrCe{sub 0,95}Yb{sub 0,05}O{sub 3-x} (SCYO). Mit tablettenfoermigen SCYO-Membranen und Ag als Elektrodenmaterial konnten CHIANG et al. zwar nur geringe Mengen an C{sub 2}-Kohlenwasserstoffen aus Methan erzeugen, allerdings bei 100% C{sub 2}-Selektivitaet, d.h. ohne Bildung von Totaloxidationsprodukten. (orig.)

Langguth, J. [Erlangen-Nuernberg Univ., Erlangen (Germany). Lehrstuhl fuer Technische Chemie 1; Dittmeyer, R. [Erlangen-Nuernberg Univ., Erlangen (Germany). Lehrstuhl fuer Technische Chemie 1; Hofmann, H. [Erlangen-Nuernberg Univ., Erlangen (Germany). Lehrstuhl fuer Technische Chemie 1; Tomandl, G. [TU Bergakademie Freiberg (Germany). Inst. fuer Keramische Werkstoffe

1997-03-01

110

76 FR 35938 - The Designation of Othman al-Ghamdi Also Known as Al Umairah al-Ghamdi, Also Known as Uthman al...  

Science.gov (United States)

...DEPARTMENT OF STATE [Public Notice 7505] The Designation of Othman al-Ghamdi Also Known as Al Umairah al- Ghamdi, Also Known as Uthman al-Ghamdi, Also Known as Uthman al- Ghamidi, Also Known as Uthman Ahmad Uthman al-Ghamdi, Also...

2011-06-20

111

estigma tolerable al estigma intolerable  

Directory of Open Access Journals (Sweden)

cristalización pasa por dos referentes de interacción y relación social al interior del espacio escolar. El primero está constituido por parámetros de normalidad y anormalidad a partir de la localización de estigmas. El segundo se encuentra, a contrapelo de la tendencia anterior, tratando de diluir los efectos de los estigmas al señalarlos como una práctica de tipificación social intolerable o inaceptable.

Nelson Arteaga Botello

2006-01-01

112

Das Geschlechterverhältnis als „irreduzible Alterität“  

Directory of Open Access Journals (Sweden)

Full Text Available Es ist das Verdienst konstruktivistischer Theoriebildungen, eine grundlegende Kritik an biologisch abgeleiteten und essentialistisch begründeten Aussagen über Geschlechtlichkeit geleistet zu haben. Das der Identitätskonstruktion vorausliegende Problem, die erkenntnistheoretische Dimension, wurde dabei jedoch weitgehend ausgeblendet. Auf der Grundlage dieser Problematik expliziert Anke Drygala in dem vorliegenden Buch die Voraussetzungen und möglichen Perspektiven des Ansatzes eines „Denkens der Differenz“ zweier Geschlechter, wie er u. a. von den Philosophinnen Geneviève Fraisse und Luce Irigaray vertreten wird. Während Geneviève Fraisse den Begriff der „Geschlechterdifferenz“ einführt, mit dem das Geschlechterverhältnis als solches zum Gegenstand der Untersuchung werden kann, denkt Luce Irigaray das Geschlechterverhältnis als „irreduzible Alterität“, in dem sich die Geschlechter nicht als gleiche oder verschiedene gegenübertreten, sondern sich in ihrer jeweiligen Andersheit als unbegreiflich und unerfassbar wechselseitig anerkennen.

Petra Ruers

2006-11-01

113

Alergia al látex: Una revisión  

Scientific Electronic Library Online (English)

Full Text Available La alergia al látex de hule natural, se ha convertido en un problema importante de salud en los trabajadores de la salud y en pacientes con espina bífida e intervenciones quirúrgicas múltiples. El tratamiento curativo con inmunoterapia no produce una solución al problema.Las medidas preventivas perm [...] iten reducir la incidencia de la alergia al látex y son una mejor estrategia para intervenir en este problema de salud pública. Con el objetivo de aumentar el conocimiento sobre el problema de alergia al látex, discutimos los aspectos relacionados con historia, epidemiología, diagnóstico, prevención y tratamiento. Se definen los términos sensibilización y alergia y se describen los aspectos químicos del látex de hule natural y de sus proteínas. La definición de grupos de riesgo permite desarrollar una estrategia en las intituciones de salud que disminuye la exposición y como consecuencia las manifestaciones clínicas de los individuos sensibilizados

Oscar, Porras Madrigal.

114

Corrosion behaviour of Al/SiC and Al/Al2O3 nanocomposites  

OpenAIRE

In the present investigation, the static immersion corrosion behavior of Al/Al2O3 and Al/SiC nanocomposites in 1 M HCl acidic solution was evaluated. The nanocomposites were fabricated using conventional powder metallurgy (P/M) route. The effect of nanoparticulates size and volume fraction on the corrosion behavior of nanocomposites was studied. The durations of the corrosion tests ranged from 24 to 120 hours and the temperatures of the solution ranged from ambient to 75 ºC. The corrosion ra...

Tamer Samir Mahmoud; El-Sayed Yousef El-Kady; Ayed Saad Merzen Al-Shihiri

2012-01-01

115

Comparing the Thermodynamic Behaviour of Al(1)+ZrO2(s) to Al(1)+Al2O3(s)  

Science.gov (United States)

In an effort to better determine the thermodynamic properties of Al(g) and Al2O(g). the vapor in equilibrium with Al(l)+ZrO2(s) was compared to the vapor in equilibrium with Al(l)+Al2O3(s) over temperature range 1197-to-1509K. The comparison was made directly by Knudsen effusion-cell mass spectrometry with an instrument configured for a multiple effusion-cell vapor source (multi-cell KEMS). Second law enthalpies of vaporization of Al(g) and Al2O(g) together with activity measurements show that Al(l)+ZrO2(s) is thermodynamically equivalent to Al(l)+Al2O3(s), indicating Al(l) remained pure and Al2O3(s) was present in the ZrO2-cell. Subsequent observation of the Al(l)/ZrO2 and vapor/ZrO2 interfaces revealed a thin Al2O3-layer had formed, separating the ZrO2-cell from Al(l) and Al(g)+Al2O(g), effectively transforming it into an Al2O3 effusion-cell. This behavior agrees with recent observations made for Beta-NiAl(Pt) alloys measured in ZrO2 effusion-cell.

Copland, Evan

2004-01-01

116

Corrosion Behavior of Al-Al3Ni and Al-Al2Cu Functionally Graded Materials Fabricated by a Centrifugal Method  

Science.gov (United States)

Intermetallic compounds, such as Al3Ni and Al2Cu, are effective for enhancing the mechanical properties of an alloy. Al-Al3Ni and Al-Al2Cu functionally graded materials (FGMs) might be attractive materials for advanced materials. Al-Al3Ni and Al-Al2Cu FGMs were fabricated by a centrifugal method; the centrifugal method is an extremely effective method for fabricating FGMs. Al-Al3Ni and Al-Al2Cu FGMs that had a graded distribution of intermetallic compounds could be produced by this in-situ centrifugal method. Particle size, particle shape and the distribution of intermetallic compounds were controlled by varying the content of the alloy element (Ni, Cu) in the master alloy, the cooling rate in casting and the gravity number. The casting mechanism is explained in terms of the microstructures of the Al-Al3Ni and Al-Al2Cu FGMs fabricated by this method. The corrosion behavior of the FGMs was investigated by electrochemical analysis. Polarization curves of the FGMs in a borate solution were measured by a potentiodynamic method. The presence of Al2Cu exerted a larger effect on the corrosion behavior of the FGMs than Al3Ni. Analysis of the polarization curve parameters was effective for evaluating the corrosion resistance of the FGMs.

Noda, Kazuhiko; Miyahara, Keita; Watanabe, Yoshimi

2008-02-01

117

Reconstruction of the New Museum in Berlin - building physics and ventilation aspects of the transparent roof design.; Wiederaufbau des Neuen Museums Berlin - Bauklimatik als Bindeglied zwischen Bauphysik und TGA-Planung  

Energy Technology Data Exchange (ETDEWEB)

The roof interstice at the New Museum in Berlin is used as an example to illustrated that, for large, continuous air spaces with external glazing, conventional design tools are often inadequate for answering strategic questions relating to building physics (condensation or ice formation) or building services design (ventilation dimensioning). This may lead to oversizing or design uncertainty. An integrated design procedure that goes beyond the limits of the individual fields involved would be superior to the conventional approach stipulated by the Fee Structure for Architects and Engineers, which is split into separate specialist areas. This is the only way of resolving interface issues between the individual fields. However, such an approach requires higher-level design tools and is associated with greater design effort. Nevertheless, the example of the reconstruction of the New Museum in Berlin shows that increased design effort can not only avoid design uncertainty, but can also lead to significantly reduced demand for building services hardware. The additional design expense is therefore often more than compensated through savings. (Abstract Copyright [2004], Wiley Periodicals, Inc.) [German] Am Beispiel des Glasdach-Zwischenraums des Neuen Museums in Berlin wird aufgezeigt, dass die herkoemmlichen Planungswerkzeuge bei grossen, zusammenhaengenden Luftraeumen mit Aussenverglasungen haeufig nicht ausreichen, um uebergreifende Fragestellungen der Bauphysik (Tauwasseranfall bzw. Eisbildung) und der TGA-Planung (Dimensionierung der Lueftung) ausreichend zu beantworten. Dies kann zu Ueberdimensionierungen und Planungsunsicherheiten fuehren. Eine dem herkoemmlichen Planungsverlauf nach HOAI mit aufgeteilten Leistungsbildern deutlich ueberlegene Vorgehensweise ist in der integralen Planung ueber die Grenzen der einzelnen Fachbereiche hinaus zu sehen. Nur so kann die Schnittstellenproblematik zwischen den einzelnen Fachbereichen aufgeloest werden. Ein solches Vorgehen erfordert jedoch hoeherwertige Planungswerkzeuge und ist mit einem hoeheren Planungsaufwand verbunden. Das Beispiel des Wiederaufbaus des Neuen Museums in Berlin zeigt jedoch, dass ein erhoehter Planungsaufwand nicht nur zur Vermeidung von Planungsunsicherheiten, sondern darueber hinaus auch zur Minimierung der erforderlichen Gebaeudetechnik fuehren kann. Der Mehraufwand bei der Planung wird somit durch Einsparungen mehr als ausgeglichen. (Abstract Copyright [2004], Wiley Periodicals, Inc.)

Pueltz, Gunter [Mueller-BBM GmbH, Robert-Koch-Strasse 11, D-82152 Planegg (Germany)

2004-10-01

118

Electron-impact ionization of Al^2+ and Al  

Science.gov (United States)

Electron-impact ionization cross sections are calculated for Al^2+ and Al. The non-perturbative R-Matrix with PseudoStates (RMPS) method was used to calculate the direct ionization of the 3s and 2p subshells and the indirect ionization of the 2p subshell for Al^2+ in a single, comprehensive calculation. This model agrees well with the experimental measurement of Thomason and Peart [1]. For Al, the RMPS and time-dependent close coupling methods are used to calculate cross sections for incident energies ranging from 5 to 30 eV. The non-perturbative close-coupling methods are found to be substantially lower than the perturbative distorted-wave cross sections due to electron correlation effects in both the direct ionization and indirect excitation-autoioniozation contributions. In addition, the close-coupling cross sections are found to be in good agreement with experiment [2]. [4pt] [1] J. W. Thomason and B. Peart J Phys B 31 L 201 (1998)[0pt] [2] R. S. Freund et al Phys. Rev. A 41 3575 (1990)

Wu, Di; Loch, S. D.; Ballance, C. P.; Abdel-Naby, Sh. A.; Pindzola, M. S.

2012-06-01

119

Bound and resonant surface states at the (110) surfaces of AlSb, AlAs, and AlP  

International Nuclear Information System (INIS)

The dispersion curves E(k-bar) have been calculated for bound and resonant (110) surface states of AlSb, AlAs, and AlP. AlSb is predicted to have no surface states within the bulk fundamental band gap, but AlAs and AlP are predicted to have surface state band minima which are very near the conduction band edge, and could lie either within the gap or immediately above the edge

120

Vom Gewohnheitstier zur reflektierten Nutzung – Ein Diskussionsanstoß über Betriebssysteme und Programmnutzung nachzudenken  

Directory of Open Access Journals (Sweden)

Full Text Available Das Nutzungsverhalten bei digitalen Medien entspringt mehr der Gewohnheit als dem vorhandenen Angebot. Ein kleiner Einblick in die Philosophie und Möglichkeiten der Nutzung von Freier Software.

Christian Berger

2010-06-01

121

Al-Madh?hib al-??f?yah f? Falimb?nj f? al-Qarnayn al-Th?min ‘Ashr wa al-T?si’ ‘Ashr  

Directory of Open Access Journals (Sweden)

Full Text Available This article attempts to trace the Islamic intellectual tradition of Palembang praying particular attention to the scholarly form that was shaped and molded by the Ulama. In addition, this article attempts to identify the characteristics of the Palembang Ulama, and draw comparisons between this group and the Ulama of the earlier Sufi period in Aceh. Of the several Ulama of Palembang who are the focus of this article, the most important are Shihab al-Din bin 'Abd Allah Muammad, Kemas Fakbr al-Din, Muhammad Muhyi al-Din, and of course, the most prominent, 'Abd al-Samad al-Falimbaani.Copyright (c 2014 by SDI. All right reserved.DOI: 10.15408/sdi.v8i2.690

Ahmad Syahid

2014-03-01

122

Vormundschaftsrecht als Grundlage politischer Herrschaft  

Directory of Open Access Journals (Sweden)

Full Text Available In ihrer beachtlichen und sehr gewissenhaft dokumentierten Arbeit über vormundschaftliche Regentschaften im 16. und 17. Jahrhundert beschreibt Pauline Puppel unter ausführlichem Bezug auf zeitgenössische Literatur und Archivalien sowohl die allgemeine Rechtslage im damaligen Reich als auch die Anwendungsfälle in Hessen, wo zwischen 1500 und 1700 insgesamt viermal eine Landgräfin als Vormünderin des Fürsten zur Regentin ihres Landes wurde. Dies steht exemplarisch für eine bereits in der Frühen Neuzeit mögliche und nicht einmal ganz seltene Form politischer Frauenherrschaft, die bisher oft nicht hinreichend gewürdigt wurde. Puppels Untersuchung ist in zwei Hauptteile gegliedert. Der erste Teil (Das juristische Regelwerk“, S. 34-143 behandelt die zeitgenössischen Rahmenbedingungen der durch Frauen ausgeübten Vormundschaft und Regentschaft. Der zweite Abschnitt („Die Landgräfinnen von Hessen als Regentinnen“, S. 144-307 befasst sich mit der Ausfüllung dieser Regeln durch konkrete Fallbeispiele in Gestalt von Leben und Regentschaft der regierenden Landgräfinnen von Hessen.

Arne Duncker

2006-07-01

123

More effectivity in the gas supply through network codes; Mehr Effektivitaet bei der Gasversorgung durch Netzkodizes  

Energy Technology Data Exchange (ETDEWEB)

Already in the year 2003, the European Commission has regulated the complete opening of the market by means of the regulation 2003/55/EG in order to develop the European Single Market positively. Practically, in Germany industrial customers can freely choose their gas suppliers since 1st July, 2004, while private customers can choose their gas suppliers since 1st July, 2007. The regulation 2003/55/EG is valid for the gas market inclusive natural gas, liquefied natural gas (LNG), biogas, gas from biomass and any other types of gas which can be transported through the natural gas distribution system.

Kremer, Andreas [EVB Energy Solutions GmbH, Velbert (Germany). EVB Akademie

2013-02-15

124

Better reliability in the projecting of geothermal wells; Mehr Sicherheit bei der Planung von Erdwaermesonden  

Energy Technology Data Exchange (ETDEWEB)

GEOWATT AG is working on new methods of measurement that will improve the quality of dimensioning of geothermal probes. This includes a new method for implementation and evaluation of thermal response tests (TRT) of geothermal probes. As a result, the vertical variation of thermal rock properties is identified as well as underground water flow if existent. The new method uses the cableless data logger NIMO-T, which records continuous temperature depth profiles of the geothermal probe before and after the TRT. (orig.)

Forrer, Silkanny; Megel, Thomas; Rohner, Ernst; Wagner, Roland [GEOWATT AG, Zurich (Switzerland)

2008-05-15

125

Airborne aerial power line inspection; Luftgestuetzte Inspektion von Freileitungssystemen. Helikopter fuer Inspektionen heute nicht mehr wegzudenken  

Energy Technology Data Exchange (ETDEWEB)

Germany is proud: in 2007 the energy customers had to accept only 19 min of power cut on average. One reason for this is the good maintenance of the aerial power lines. It is not possible to achieve this without the use of helicopters. To make this method more effective Pergam-Suisse used the existing knowledge and experience from the airborne gas leak detection to realize a concept for power line inspection: A 4-axis stabilized gimbal, equipped with a measuring high resolution thermal imaging camera, a visual camera and a GPS module for mounting on several types of helicopters. (orig.)

Horn, B.A. [NDT Application, Pergam-Suisse AG, Zuerich (Switzerland)

2008-11-03

126

Energy conservation potentials of up to 35% and more; Einsparpotenziale von 35 % und mehr  

Energy Technology Data Exchange (ETDEWEB)

The automobile industry sets standards in many areas such as in the topic energy efficiency. Thus, the innovation alliance 'Green Carbody Technologies' aims to realizes a car body manufacturing with 50% lower energy consumption. One of the subprojects within the research project concerned itself with an energy efficient air conditioning of switch control boxes. The company Rittal GmbH and Co. KG (Herborn, Federal Republic of Germany) is involved in this subproject. First results of this subproject are described now.

Heimberg, Thorsten; Knetsch, Joerg; Martin, Lars; Wagner, Steffen [Rittal GmbH und Co. KG, Herborn (Germany)

2013-04-01

127

Greater efficiency for man and machine; Mehr Effizienz fuer Mensch und Maschine  

Energy Technology Data Exchange (ETDEWEB)

With its new family of shunting locomotives, Vossloh Locomotives sets new standards in technology, safeguarding of investment and consultancy. Alongside three diesel-hydraulic models, the standard portfolio now also includes two diesel-electric models with power output of up to 1,800 kilowatts. The latter models have been designed such that Vossloh will be able to supply spare parts at short notice over a service life of up to 30 years. All locomotives are based on a modular architecture that can be adapted to individual and country-specific requirements depending on the application. In addition, Vossloh has developed innovative tools for the new loco family that enable operators to analyse their locomotives' fuel consumption and optimise it according to their use. (orig.)

Ramcke, Bernd; Hildebrandt, Tim [Vossloh Locomotives GmbH, Kiel (Germany)

2010-09-15

128

Risked a lot and won a lot more; Viel gewagt, mehr gewonnen  

Energy Technology Data Exchange (ETDEWEB)

What do 7,300 inhabitants with a 90 hectare great ammunition depot of the Bundeswehr? They build a bioenergy park. This courageous decision not only attracts hordes of visitors to Saerbeck, it also provides for regular incomes. [German] Was fangen 7.300 Einwohner mit einem 90 ha grossen Munitionsdepot der Bundeswehr an? Sie bauen einen Bioenergiepark. Die mutige Entscheidung lockt nicht nur Heerscharen von Besuchern nach Saerbeck, sie sorgt auch fuer regelmaessige Einnahmen.

Thomas, Torsten

2013-07-05

129

Auf dem Weg zu mehr Gleichheit? Sozialpolitik in Brasilien und Chile nach dem „Linksruck“  

Directory of Open Access Journals (Sweden)

Full Text Available In dem Beitrag werden die sozialpolitischen Initiativen in der Regierungsperiode von Michelle Bachelet (2006–2011 in Chile und von Luiz Inácio Lula da Silva (2003–2011 in Brasilien dargestellt. Beide sozialdemokratischen Regierungen markieren im jeweiligen nationalen Kontext einen Linksruck. Die Untersuchung geht der Frage nach, ob die Reformen eine gleichheitsfördernde Wirkung entfaltet haben und einen Bruch mit neoliberalen Paradigmen in der Sozialpolitik bedeuten. Um die aktuellen Veränderungen einschätzen zu können, werden diese in einen größeren historischen und politökonomischen Kontext eingebettet. Die Analyse der Wohlfahrtsregime der beiden Länder stützt sich auf den institutionalistischen Zugang von Esping-Andersen. Mit Bezug auf Kategorien wie Universalisierung, De-Kommodifizierung/Anti-Wert, De-Familialisierung und Informalität wagen die AutorInnen am Ende eine Einschätzung, inwiefern unter Lula und Bachelet sozialdemokratische Politik betrieben wurde.

Karin Fischer

2012-03-01

130

X-ray can do more; ''Roentgen'' kann noch mehr  

Energy Technology Data Exchange (ETDEWEB)

Radiography is not the only technology for characterising components and materials. Other methods which make use of X-ray radiation to characterise materials include X-ray fluorescence analysis (RFA) and, a technique still neglected to date, X-ray diffractometry (XRD) including small-angle X-ray scattering (SAXS) and X-ray reflectometry (XRR, GISAXS). This paper presents the capabilities, limits and application areas of these other X-ray techniques, which add to the range of nondestructive material characterisation methods beside classical radiography. Material analyses of brass materials are used as examples.

Spiess, Lothar [Technische Univ. Ilmenau (Germany). Inst. fuer Werkstofftechnik; Teichert, Gerd [Technische Univ. Ilmenau (Germany). MFPA Weimar Pruefzentrum Schicht- und Materialeigenschaften

2013-07-01

131

Biogas - more courage to compete in the market; Biogas. Mehr Mut zum Markt  

Energy Technology Data Exchange (ETDEWEB)

Biogas has excellent prospects for becoming the fastest growing renewable energy resource in Germany over the coming decades. Its great versatility in application (electricity, heat, drive energy), and its good storability open up a wide array of opportunities. However, the biogas industry will harm itself if it continues to insist on the enactment of a renewable gas feed law with statutory remuneration rates. This would not only curb the profit opportunities that result from the great versatility of biologically produced gas but would even create economic risks. What the market really needs on the other hand is nondiscriminatory access for biomethane suppliers to the German natural gas grid and their participation in the market as equal partners.

Pasch, Karl-Heinz [EnD-I AG, Halle (Saale) (Germany)

2010-06-15

132

[Joint involvement in AL amyloidosis].  

Science.gov (United States)

This review is aimed at defining the frequency, the clinical, biological and radiological presentation and the therapeutic possibilities for AL amyloid arthropathies. The frequency of AL amyloid arthropathy is estimated to be between 2 and 5%. There is usually a bilaterally progressive symmetrical arthritis of multiple joints (predominantly in the upper limb joints) with a chronic evolution. Neurologic or cutaneous symptoms are common. The analysis of synovial fluid sediments is a key test for the diagnosis of amyloid arthropathy. Patients with amyloid arthropathy must be screened for monoclonal gammapathies. The synovectomy is the best symptomatic treatment. A better knowledge of the pathogenesis of amyloid deposits should permit to improve therapeutical strategies. PMID:10519016

Blanco, P; Viallard, J F; Bonotto, B; Buy, E; Pellegrin, J L; Leng, B

1999-06-01

133

Development of Al^+ optical clocks  

Science.gov (United States)

Low sensitivity to electromagnetic fields and a narrow natural line width have enabled the ^1S0 -- ^3P0 transition in Al^+ to achieve 8.6 x 10-18 accuracy. This allows for precise gravitational red-shift measurements with possible applications in geodesy, hydrology, and other fundamental tests of physics. However, the current laboratory system is not yet usable for these applications, due to the complexity of operation. We report recent progress towards the goals of higher accuracy and simplified non-laboratory operation of Al+ clocks.

Chen, Jwo-Sy; Ni, Kang-Kuen; Chou, Chin-Wen; Wineland, David J.; Rosenband, Till

2012-06-01

134

The ?-decay of 22Al  

International Nuclear Information System (INIS)

In an experiment performed at the LISE3 facility of GANIL, we studied the decay of 22Al produced by the fragmentation of a 36Ar primary beam. A ?-decay half-life of T1/2=91.1±0.5 ms was measured. The ?-delayed one- and two-proton emission as well as ?-? and ?-delayed ?-decays were measured and allowed us to establish a partial decay scheme for this nucleus. New levels were determined in the daughter nucleus 22Mg. The comparison with model calculations strongly favours a spin-parity of I?=4+ for the ground state of 22Al. (orig.)

135

AlN/Al dual protective coatings on NdFeB by DC magnetron sputtering  

International Nuclear Information System (INIS)

AlN/Al dual protective coatings were prepared on NdFeB by DC magnetron sputtering in a home-made industrial apparatus. Comparing with Al coating, AlN/Al coatings have a denser structure of an outmost AlN amorphous layer following an inner Al columnar crystal layer. The coatings and NdFeB substrate combine well, and moreover, there is occurrence of metallurgy bonding in the interface layer. Both Al and AlN/Al coatings have a good protective ability to NdFeB. Especially, the corrosion resistance of AlN/Al coated NdFeB is improved largely. AlN/Al and Al protective coatings not only do not deteriorate the magnetic properties of NdFeB, but contribute to their slight increase.

136

Identification of Candida albicans ALS2 and ALS4 and Localization of Als Proteins to the Fungal Cell Surface  

OpenAIRE

Additional genes in the growing ALS family of Candida albicans were isolated by PCR screening of a genomic fosmid library with primers designed from the consensus tandem-repeat sequence of ALS1. This procedure yielded fosmids encoding ALS2 and ALS4. ALS2 and ALS4 conformed to the three-domain structure of ALS genes, which consists of a central domain of tandemly repeated copies of a 108-bp motif, an upstream domain of highly conserved sequences, and a domain of divergent sequences 3? of the...

Hoyer, L. L.; Payne, T. L.; Hecht, J. E.

1998-01-01

137

Glassy behavior of interface states in Al-AlOx-Al tunnel junctions  

CERN Document Server

We present results of a study of tunnel junction aging in which the early time dynamics are captured by in situ monitoring of electrical properties of Al-AlOx-Al planar tunnel junctions beginning when the deposition of the counterelectrode is complete. The observed stretched exponential dependences of the conductance and the capacitance manifest hierarchically constrained dynamics imposed by correlated relaxations of interface traps. Bias voltage is used as a control parameter to create bias-dependent aging trajectories that exhibit memory and age-dependent relaxations. Simple tunnel barrier and equivalent circuit modeling provide a comprehensive understanding of this novel and unexpected glassy behavior that appears to be unique to tunnel junctions and has important implications for technical applications.

Nesbitt, J R; Nesbitt, Jeremy R.; Hebard, Arthur F.

2005-01-01

138

"PULS." – ein Blog als Online-Magazin für Medizinstudierendeder Goethe-Universität Frankfurt ["PULS." – a Blog-based Online-Magazine for Students of Medicine of the Goethe University Frankfurt  

Directory of Open Access Journals (Sweden)

Full Text Available [english] In the context of nationwide protests 2009 also students of the faculty of medicine/dentistry at Goethe-University in Frankfurt demanded more transparency and communication. To satisfy these demands, a web 2.0-tool offered an innovative solution: A blog-based online-magazine for students and other faculty-members.The online-magazine „PULS.“ is realized with the share-ware blog-software (wordpress version 3.1.3 and is conceived and written by an online-journalist. „PULS.“ is available from .The articles are generated from own investigations and from ideas of different groups of the faculty– deanship, students and lecturers. A user-analysis is conducted with the open-source software Piwik and considers the data security. Additionally, every year an anonymous online-user-survey (Survey Monkey is conducted.“PULS.” is continuously online since 14.02.2010 and has published 806 articles (state: 27.11.2012 and has about 2400 readers monthly. The content focuses on the needs of Frankfurt medical students. The close cooperation with different groups of the faculty - deanship, students and lecturers - furthermore guarantees themes relevant to the academic faculty. “PULS.” flanks complex projects and decisions with background-information and communicates them understandable.The user-evaluation shows a growing number of readers and a high acceptance for the online-magazine, its themes and its style. The web 2.0-tool “Blog” and the web-specific language comply with media habits of the main target group, the students of the faculty medicine/dentistry.Thus, “PULS.” has proven as a suitable and strategic instrument. It pushes towards a higher transparency, more communication and a stronger identification of the students with their faculty.[german] Im Herbst 2009 forderten Studierende im Rahmen landesweiter Proteste auch am Fachbereich Medizin/Zahnmedizin der Goethe-Universität Frankfurt mehr Transparenz und Kommunikation zu Angelegenheiten ihres Studiums. Einen innovativen Lösungsansatz, um diesen Forderungen nachzukommen, bietet eines der Web 2.0 Werkzeuge: ein auf einer Blog-Software basierendes Online-Magazin für Studierende und andere Mitglieder des Fachbereichs.Das öffentlich zugängliche Online-Magazin „PULS.“ ( wird mit einer freien Blog-Software (wordpress Version 3.1.3. realisiert und von einer Online-Redakteurin konzipiert und geschrieben. Die Beiträge entstehen nach eigenen Recherchen sowie aus Anregungen und Gesprächen mit verschiedenen Personengruppen des Fachbereichs. Die datenschutzkonforme Auswertung der Zugriffe erfolgt über eine open-source Webanalyse-Software (Piwik. Zusätzlich werden jährlich mit dem Online-Umfrage-Tool Survey Monkey die Nutzer anonym befragt.„PULS.“ ist seit dem 14.02.2010 ununterbrochen online und hat seitdem 806 Beiträge (Stand: 27.11.2012 publiziert und wird von ca. 2400 Besuchern monatlich gelesen. Das Themenspektrum ist zentriert auf die Anliegen der Frankfurter Medizin- und Zahnmedizinstudierenden. Die enge Zusammenarbeit mit verschiedenen Gruppierungen des Fachbereichs – Dekanat, Studierende und Lehrende – garantiert darüber hinaus ein fachbereichs-relevantes Themenspektrum. Das Online-Magazin begleitet komplexe Projekte und Entscheidungen mit Hintergrundinformationen und kommuniziert sie verständlich. Eine jährliche Nutzer-Evaluierung zeigt eine wachsende Leserzahl und eine sehr hohe Zustimmung für das Online-Magazin, seine Inhalte und seinen Stil. Das Web 2.0-Medium „Blog“ und seine web-typische Sprache entsprechen dem Medienverhalten der Zielgruppe, d.h. den Studierenden des Fachbereichs Medizin. „PULS.“ hat sich als ein geeignetes und strategisches Instrument erwiesen, um größere Transparenz, mehr Kommunikation und letztendlich eine stärkere Identifikation der Studierenden mit ihrem Fachbereich voranzutreiben.

Nürnberger, Frank

2013-02-01

139

Nuclear spectroscopy of 26Al  

International Nuclear Information System (INIS)

The tensor analyzing powers T20 and the cross sections for the reaction 28Si(d vector, ?)26Al to levels in 26Al with excitation energies up to 6 MeV have been measured at thetasub(lab)=1750. The bombarding energy was varied in steps of 0.5 MeV from 10.0 to 12.5 MeV. Comparison of the measured T20 values with theoretical predictions, taking into account the finite-angle effect, has led to assignments of natural or unnatural parity to some fifty levels in 26Al. Two levels with Jsup(?)=0- could be identified on the basis of such a comparison. A (probable) assignment of Jsup(?)=0+ could be made to two levels in 26Al on the basis of a very low observed cross section. The information on spin-parity combinations found in this work was combined with spectroscopic data from other reactions to deduce new unambiguous Jsup(?) assignments for 33 levels and Jsup(?) restrictions for another three levels. (orig.)

140

Eine wasserdurchlässige Dampfbremse als Hygrodiode  

DEFF Research Database (Denmark)

Hohe Feuchtigkeit unde freies Wasser in Baukonstruktionen könne zu Bauphysikalischen Problemen und Schäden führen. Vor allem während der Bauphase eingebrachchtes oder durch Risse eindringendes Wasser, das bei ungünstigen Konstruktionen nur schlecht austrocknet, wird in der Winterperiode durch Diffusionsprozesse noch erhöht. Eine wasserdurchlässige Dampfbremse als Hygrodiode erlaubt die sichere kapillare Rückführung des Wassers zur Raumseite, wo es verdunsten kann.

Sagelsdorff, Ralph; Rode, Carsten

1997-01-01

141

DOSIS AL FETO EN RADIODIAGNOSTICO  

Directory of Open Access Journals (Sweden)

Full Text Available Se discute los efectos de la irradiación al feto y sus consecuencias, según dosis recibida, considerando la eventual suspensión de embarazo por esta causaIrradiation and its effects over fetus are discussed. Also the eventuality of termination of gestation from this cause is considered

Mauricio Vergara E.

2005-01-01

142

ASK Talks with Al Diaz  

Science.gov (United States)

Following the release of the Columbia Accident Investigation Board (CAIB) Report, Alphonso (Al) Diaz, Goddard Center director, was asked by NASA Administrator Sean O'Keefe to head up the Agency's response. The Diaz team, as it came to be known, was changed with making sure the CAIB Report did not become another dusty volume on a shelf of old Agency reviews.

Diaz, Alphonso; OKeefe, Sean

2004-01-01

143

Atomic and electronic structure of ultra-thin Al/AlOx/Al interfaces  

CERN Document Server

Interfaces between metals based on AlO$_{x}$ represent the most popular basis for Josephson junctions or, more recently, also for junctions exhibiting substantial tunneling magneto-resistance. We have performed a computational study of possible local geometric structures of such interfaces at the ab-initio DFT/GGA level of approximation to complement recent experimental data on ultra-thin AlO$_{x}$-based interfaces. We present two competing structures that we characterise with their electronic properties: fragmentation and interface energies.

Dieskova, M; Bokes, P

2006-01-01

144

First principles calculation of ac conductance for Al-BDT-Al and Al-Cn-Al systems  

Directory of Open Access Journals (Sweden)

Full Text Available We perform first-principles calculation to investigate the dynamic conductance of atomic wires of the benzenedithiol (BDT as well as carbon chains with different length in contact with two Al(100 electrodes (Al-Cn-Al. Our calculation is based on the combination of the non-equilibrium Green's function and the density functional theory. For ac conductance, there are two theories that ensures the current conservation: (1. the global formula which is a phenomenological theory that partitions the total displacement current into each leads so that the current is conserved.(2. the local formula which is a microscopic theory that includes Coulomb interaction explicitly so that the current is conserved automatically. In this work, we use the local formula to calculate the dynamic conductance, especially the emittance. We give a detailed comparison and analysis for the results obtained from two theories. Our numerical results show that the global formula overestimates the emittance by two orders of magnitude. We also obtain an inequality showing that the emittance from global formula is greater than that from local formula for real atomic structures. For Al-Cn-Al structures, the oscillatory behavior as the number of carbon chain N varies from even to odd remains unchanged when local formula is used. However, the prediction of local formula gives rise to opposite response when N is odd (inductive-like as compared with that of global formula. Therefore, one should use the local formula for an accurate description of ac transport in nanoscale structures. In addition, the ‘size effect’ of the ac emittance is analyzed and can be understood by the kinetic inductance. Since numerical calculation using the global formula can be performed in orbital space while the local formula can only be used in real space, our numerical results indicate that the calculation using the local formula is extremely computational demanding.

Jia-Ning Zhuang

2011-12-01

145

The temperature dependence of elasticity modulus for TiAl and Ni3Al – basic alloy components for turbine rotor blade. ????????????? ??????????? ?????? ????????? ??????????????? TiAl ? Ni3Al – ???????? ??????????? ??????? ??? ??????? ??????? ??????.  

Directory of Open Access Journals (Sweden)

Full Text Available Possibility of theoretical determination of elastic characteristics for intermetallides on the example of TiAl and Ni3Al on the base of electrostatic nature of elasticity is demonstrated. Elaborated method is able for using for computing modeling of mono- and polycrystal materials under conditions of experimental data absence. ????????? ?????????? ?????????????? ??????????? ????????????? ??????????? ?????? ???? ?? ?????? ?????????????????? ??????? ????????? ??????????????? ?? ??????? TiAl ? Ni3Al. ????????????? ????? ????? ???????????? ??? ????????????? ????????????? ????- ? ??????????????????? ?????????? ? ???????? ?????????? ????????????????? ??????.

?. ?. ????????

2013-01-01

146

Electrowinning Al from Al2S3 in Molten Salt :  

OpenAIRE

In order to investigate an alternative process for the production of primary aluminum via a sulfide intermediate, the electrochemical behavior of Al2S3 in molten salt has been studied on a laboratory scale. The effects of electrolyte composition, temperature, and cell design on the cell performance have been investigated. Temperature and cryolite addition have positive effects on the current density. Increasing the anode-to-cathode surface area (closer to unity) and shortening the interelectr...

Xiao, Y.; Plas, D. W.; Bohte, J.; Lans, S. C.; Sandwijk, A.; Reuter, M. A.

2007-01-01

147

Synthesis of NiAl, CoAl intermetallics and NiAl-Nb and CoAl-Co composites from elemental powders via solid state reactions  

International Nuclear Information System (INIS)

NiAl, CoAl intermetallics and NiAl-Nb, CoAl-Co composites were synthesized in solid state from elemental powders. Blends of ultrafine powders were high pressure consolidated to full density. This was followed by heat treatments, resulting in multistage solid state reactive diffusion. The phase composition and microstructure of obtained materials were investigated employing X-ray diffraction, SEM/EDX and TEM. The sequence of reactions in consolidated powder blends was determined, the kinetics of formation of different phases was measured. For Ni-Al-Nb blends, formation of only Ni-Al intermetallic phases including NiAl was detected in temperature range 425 C--550 C. Followed heat treatment at higher temperatures resulted information of NiAl-Nb composite. Phase stability of NiAl-Nb and CoAl-Co composites was investigated in temperature range 800 C--1,100 C

148

High quality Nb/Al-AlOx/Nb Josephson junction  

International Nuclear Information System (INIS)

We have improved the quality of Nb/Al-AlOx/Nb Josephson junctions and obtained the most excellent junction characteristics ever obtained for all refractory Josephson junctions. The V/sub m/ values (the product of the critical current and the subgap resistance measured at 2 mV) are 88 mV at the critical current density I/sub j/ = 500 A/cm2 and 72 mV at I/sub j/ = 1000 A/cm2. The V/sub m/ values are larger than 40 mV up to I/sub j/ of 2400 A/cm2. The high V/sub m/ values are important to obtain the low subgap leakage current and not to reduce the transfer current to the load in Josephson circuit. These characteristics have been achieved by improving the quality of the Nb film and optimizing the Al thickness. We have also confirmed that I/sub j/ can be controlled by both the oxidation pressure and time in the range of 40--4600 A/cm2

149

AlSb/InAs/AlSb quantum wells  

Science.gov (United States)

Researchers studied the InAs/AlSb system recently, obtaining 12nm wide quantum wells with room temperature mobilities up to 28,000 cm(exp 2)/V center dot S and low-temperature mobilities up to 325,000 cm(exp 2)/V center dot S, both at high electron sheet concentrations in the 10(exp 12)/cm(exp 2) range (corresponding to volume concentrations in the 10(exp 18)/cm(exp 2) range). These wells were not intentionally doped; the combination of high carrier concentrations and high mobilities suggest that the electrons are due to not-intentional modulation doping by an unknown donor in the AlSb barriers, presumably a stoichiometric defect, like an antisite donor. Inasmuch as not intentionally doped bulk AlSb is semi-insulating, the donor must be a deep one, being ionized only by draining into the even deeper InAs quantum well. The excellent transport properties are confirmed by other observations, like excellent quantum Hall effect data, and the successful use of the quantum wells as superconductive weak links between Nb electrodes, with unprecendentedly high critical current densities. The system is promising for future field effect transistors (FETs), but many processing problems must first be solved. Although the researchers have achieved FETs, the results so far have not been competitive with GaAs FETs.

Kroemer, Herbert

1990-01-01

150

Diffusion AlSi-MeCrAlY coatings obtained on intermetallic ?-TiAl phase  

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Full Text Available Purpose: The development of new protective coatings for TiAl intermetallics was conducted. The MeCrAlYAlSi slurry was used with different amount of aluminium-silicon powder in the binder.Design/methodology/approach: The slurry consisting of aluminium and silicon powder with the addition of MeCrAlY powder were used during the procedure. The inorganic solution made from chromic and phosphoric acid was applied as a binder. The preliminary research of microstructure of obtained coatings was conducted.Findings: The obtained coating consisting of 3 or 4 zones (depending on chemical composition of the slurry was obtained during the annealing process (950°C/4h.Research limitations/implications: The research results revealed the possibility of obtaining coatings with complex phase and chemical composition.Practical implications: Many problems connected with sedimentation of heavier MeCrAlY powder were observed.Originality/value: The copletele new technologies was described in article

M. Góral

2012-12-01

151

Transient oxidation of Al-deposited Fe-Cr-Al alloy foil  

International Nuclear Information System (INIS)

The oxide phases formed on an Al-deposited Fe-Cr-Al alloy foil and an Fe-Cr-Al alloy foil of the same levels of Al and (La+Ce) contents, and their oxidation kinetics have been studied in air at 1173 and 1373 K using TGA, XRD and SEM. Al deposition promotes the growth of metastable aluminas (?-Al2O3, ?-Al2O3). Scales consisting of ?-Al2O3 and a small amount of ?-Al2O3 develop on the Al-deposited foil at 1173 K and exhibit the whisker-type morphology. In the early stage of oxidation at 1373 K, thick scales consisting of ?-Al2O3 and ?-Al2O3 grow rapidly on the Al-deposited foil. The transformation from ?-Al2O3 to ?-Al2O3 is very fast, and the scales result in only ?-Al2O3. In contrast, ?-Al2O3 scales containing a minor amount of FeAl2O4 develop on the alloy foil. The growth rate of ?-Al2O3 scales on the Al-deposited foil is smaller than that on the alloy foil and very close to that on NiAl at 1373 K. (orig.)

152

Structure and stability of the AlX and AlX- species  

International Nuclear Information System (INIS)

The electronic and geometrical structures of the ground and low-lying excited states of the diatomic AlX and AlX- series (X=H, Li, Be, B, C, N, O, and F) are calculated by the coupled-cluster method with all singles and doubles and noniterative inclusion of triples using a large atomic natural orbital basis. All the ground-state AlX molecules except for AlF can attach an additional electron and form ground-state AlX- anions. The ground-state AlBe-, AlB-, AlC-, AlN-, and AlO- anions possess excited states that are stable toward autodetachment of an extra electron; AlBe- also has a second excited state. Low-lying excited states of all AlX but AlN can attach an extra electron and form anionic states that are stable with respect to their neutral (excited) parent states. The ground-state AlLi-, AlBe-, AlB-, AlN-, and AlO- anions are found to be thermodynamically more stable than their neutral parents. The most stable is AlO-, whose dissociation energy to Al+O- is 6.4 eV. Correspondingly, AlO possesses the largest electron affinity (2.65 eV) in the series. copyright 1999 American Institute of Physics

153

Structure and stability of the AlX and AlX- species  

Science.gov (United States)

The electronic and geometrical structures of the ground and low-lying excited states of the diatomic AlX and AlX- series (X=H, Li, Be, B, C, N, O, and F) are calculated by the coupled-cluster method with all singles and doubles and noniterative inclusion of triples using a large atomic natural orbital basis. All the ground-state AlX molecules except for AlF can attach an additional electron and form ground-state AlX- anions. The ground-state AlBe-, AlB-, AlC-, AlN-, and AlO- anions possess excited states that are stable toward autodetachment of an extra electron; AlBe- also has a second excited state. Low-lying excited states of all AlX but AlN can attach an extra electron and form anionic states that are stable with respect to their neutral (excited) parent states. The ground-state AlLi-, AlBe-, AlB-, AlN-, and AlO- anions are found to be thermodynamically more stable than their neutral parents. The most stable is AlO-, whose dissociation energy to Al+O- is 6.4 eV. Correspondingly, AlO possesses the largest electron affinity (2.65 eV) in the series.

Gutsev, Gennady L.; Jena, Puru; Bartlett, Rodney J.

1999-02-01

154

MTBE experts' discussion: Environmental pollution from MTBE fuel additives. Proceedings; MTBE-Fachgespraech: Umweltbelastungen durch die Nutzung von MTBE (Methyl-tertiaer-butylether) als Kraftstoffzusatz. Tagungsband  

Energy Technology Data Exchange (ETDEWEB)

MTBE is a volatile, water-soluble, oxygen-containing liquid with a high octane rating. It hardly absorbs to the soil matrix, is hardly degradable by biological means, and moves in groundwater at practically the same speed as the groundwater itself. This makes it an important groundwater hazard. The main problem is the low taste and smell threshold concentration of MTBE, because of which contaminated water is unfit for drinking. MTBE has been used as a fuel additive in the USA since the seventies and in Germany since the eighties for a better antiknock rating. MTBE concentrations depend on the fuel quality, ranging from 0.3 percent in normal gasoline and 1.6 percent in super gasoline to 6-12 percent by volume in SuperPlus and Optimax fuels. At this conference, which comprised nine lectures and a round of detailed discussions, measured concentrations of MTBE in air, precipitations, surface water and groundwater were presented, and the possibilities of modelling were discussed. The attendants of the meeting agreed that in view of the available data and at the present state of knowledge concerning the sources and fate of MTBE in environmental media, MTBE cannot be excluded as a groundwater pollutant. (orig.) [German] MTBE ist eine leichtfluechtige, gut wasserloesliche, sauerstoffhaltige Fluessigkeit mit hoher Oktanzahl. Es sorbiert fast nicht an die Bodenmatrix, ist sehr schlecht biologisch abbaubar und bewegt sich im Grundwasser praktisch mit der gleichen Geschwindigkeit wie das Grundwasser selbst. Aufgrund dieser Eigenschaften stellt MTBE eine Gefahr fuer das Grundwasser dar. Problematisch aus Sicht der Wasserversorgung ist die niedrige Geruchs- und Geschmacksschwelle von MTBE, weshalb kontaminiertes Wasser nicht mehr als Trinkwasser brauchbar ist. MTBE wird seit Mitte der 70er Jahre in den USA und seit Anfang der 80er Jahre in Deutschland dem Benzin zugesetzt, um die Klopffestigkeit zu verbessern. Der MTBE-Gehalt haengt von der Benzin-Qualitaet ab: Waehrend Normalbenzin bei uns durchschnittlich 0,3% und Super 1,6% MTBE enthalten, liegen die Werte fuer SuperPlus und Optimax bei etwa 6-12% Vol-%. In neun Fachvortraegen und einer ausfuehrlichen Diskussionsrunde, die in dem vorliegenden Tagungsband wiedergegeben sind, wurden Messdaten zur Konzentration von MTBE in Luft, Niederschlag, Oberflaechen- und Grundwasser vorgestellt und die Moeglichkeiten einer Modellbildung eroertert. Die Teilnehmer des Fachgespraechs waren sich einig, dass die derzeitige Datenlage und die Kenntnisse zum Vorkommen und zu den Verbreitungswegen von MTBE in den Umweltmedien keinesfalls geeignet sind, abschliessend Entwarnung zu geben und eine Grundwassergefaehrdung durch MTBE auszuschliessen. (orig.)

NONE

2002-07-01

155

Blut ist dicker als Wasser  

Directory of Open Access Journals (Sweden)

Full Text Available Der Band basiert auf Beiträgen des an der Humboldt-Universität zu Berlin angesiedelten Forschungsprojektes „Verwandtschaft als Repräsentation sozialer Ordnung und sozialer Praxis: Kulturen der Zusammengehörigkeit im Kontext sozialer und reproduktionsmedizinischer Transformationsprozesse”. In dreizehn Artikeln wird anhand der Länder Deutschland, Türkei und Großbritannien der Frage nachgegangen: „Wie macht man Verwandtschaft?“ Angesichts des unaufhaltsamen Voranschreitens der Reproduktionsmedizin ist die Lektüre dieses Bandes vorbehaltlos zu empfehlen.

Susanne Benöhr-Laqueur

2008-03-01

156

Al Margen de las Cooperativas  

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Full Text Available El sistema Cooperativista, propiamente hablando, no viene a constituir una doctrina económica, es más bien una práctica, un modo de proceder en provecho de determinada agrupación de individuos que se asocian para defenderse de la usura del comercio y del intermediarismo parasitario. "El movimiento cooperativo es tan viejo como la revolución industrial, y ha crecido paralelamente a ella, podría decirse como una protesta en contra del sistema capitalista industrial. Generalmente se considera que tres principios fundamentales determinan su carácter distintivo. 1-Se esfuerza por dar "servido al costo" a sus miembros antes que beneficiarse del negocio con el público en general. El servicio de un grupo organizado se considera como un medio para obtener el máximum de eficacia con mínimo de desperdicio. 2-Insiste en que los beneficios pecuniarios se distribuyan al miembro como productor, después de deducir solamente el interés del capital al tipo que compite, y los salarios y jornales de los trabajadores. 3-Mantiene el control democrático del negocio por todos los participantes en él".

Gutiérrez Estrada Julio

1941-04-01

157

Armaflex in Burj al Arab; Armaflex im Burj al Arab  

Energy Technology Data Exchange (ETDEWEB)

This article describes the Burj al Arab in Dubai, the unique seven-star high-rise hotel. The construction of the hotel, that is built on 250 piles driven into the sand of an artificial island in the Persian Gulf, is described. In particular, various special materials used in the building are described, as are the luxurious fittings and furnishings of the hotel. The cooling and air-conditioning installations that are necessary as a result of the desert climate of Dubai are described and the use of 'Armaflex' elastomer insulating material for the insulation of refrigeration machines and cold-water piping is discussed.

Steiner, B.

2003-07-01

158

The Collections - Dar al-Athar al-Islamiyyah  

Science.gov (United States)

Regarded by experts as one of a handful of the most comprehensive collections of Islamic art in the world, the al-Sabah holdings in Kuwait feature 20,000 objects from geographically and chronologically diverse locations. Nine categories - Metals, Ceramics, Glass, Ivory & Wood, Jewelry & Hardstone, Numismatics, Rugs & Textiles, Manuscripts & Calligraphy, and Stone & Stucco - can be accessed from the collections page with the click of a mouse. Within each category, short essays contextualize the beautiful photographs of ancient, medieval, and modern Islamic art in a wide variety of mediums and styles.

159

77 FR 73732 - In the Matter of Amendment of the Designation of al-Qa'ida in Iraq, aka Jam'at al Tawhid wa'al...  

Science.gov (United States)

...The al-Zarqawi Network, aka al-Tawhid, aka Tanzim Qa`idat al-Jihad fi Bilad al-Rafidayn, aka The Organization of al-Jihad's...of Operations in the Land of the Two Rivers, aka Tanzeem qa'idat al Jihad/Bildad al Raafidaini, as a Foreign Terrorist...

2012-12-11

160

Alergia al semen / Semen allergy  

Scientific Electronic Library Online (English)

Full Text Available La alergia al semen comprende una variedad de síntomas tanto locales como sistémicos causados por reacciones de hipersensibilidad inmediata y caracterizados por títulos elevados de IgE. El objetivo de este estudio es describir el caso de una paciente con alergia al semen: mujer de 21 años de edad qu [...] e presenta ardor y sensación de quemazón en el área genital luego de tener contacto con el semen de su pareja. El análisis seminal del compañero sexual no presenta ningún tipo de alteración. Los síntomas desaparecen con el uso de condón o con la práctica del coito interrumpido. La alergia al semen es una alteración, que si bien es poco frecuente, puede afectar los deseos de concepción de las mujeres que la presentan, es un fenómeno poco estudiado por lo que se requieren más reportes para su caracterización. Abstract in english Semen allergy includes several local and systemic symptoms caused by immediate hypersensitivity reactions and it is characterized by high levels of IgE. The objective of this study was to describe the case of a patient with semen allergy. A 21 year-old woman experienced itching and burning sensation [...] in the genital area after contact with the semen of her sexual partner. Semen analysis was normal. Symptoms disappear with the use of condom or the practice of coitus interruptus. Semen allergy is a condition, although rare, can affect the desire of conceiving in women who suffers it. It is a briefly studied phenomenon which requires more reports for proper characterization.

Laura, Franco Cuadros; Jenniffer, Puerta Suárez; Ángela, Cadavid Jaramillo; Walter, Cardona Maya.

2013-12-01

161

Jongerenwerk als werkplaats voor professionalisering  

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Full Text Available Partnership approach as alternate professionalization strategy for youth work In the Netherlands, there is a growing debate on the need for the professionalization of youth work practice. There is a consensus on the necessity and relevance of professionalization. Opinions differ however on the appropriate pathways towards professionalization. Classic professionalization strategies, with a focus on the gathering of scientific experimental evidence, often do not match with the complex and flexible nature of youth work practice. To gain insight in alternative strategies, providers of youth work and study programs in Amsterdam joined forces and set up Youth Spot, a research and practice centre for youth work. This article describes how the centre, youth work organizations, education and researchers cooperate in the professionalization of youth work. On the one hand this article provides insight in youth work’s own professionalism and, on the other hand, it offers experiences with an alternate professionalization strategy. Jongerenwerk als werkplaats voor professionalisering Dit artikel beschrijft hoe opleidingen, welzijnsorganisaties en onderzoekers samenwerken in de professionalisering van het jongerenwerk tegen de achtergrond van het debat over professionalisering van de sociaal agogische beroepen. Het probleem met klassieke professionaliseringstrategieën, met wetenschappelijke experimentele kennis als norm, is dat zij niet altijd goed aansluiten bij de complexiteit en flexibiliteit van de uitvoeringspraktijk. Vraag is: wat dan wel? In Amsterdam richten opleidingen en werkveld in 2008 Youth Spot op, het onderzoek- en praktijkcentrum voor jongerenwerk, met als doel om gezamenlijk te werken aan de profilering, professionalisering en praktijkontwikkeling van het jongerenwerk. Dit artikel belicht de aanleiding voor het ontstaan van Youth Spot, de structuur van de samenwerking, de ervaringen met de wijze van samen werken en de meerwaarde voor de professionalisering van het grootstedelijk jongerenwerk. Daarmee biedt dit artikel enerzijds een kijkje in de keuken van het (grootstedelijke jongerenwerk en anderzijds biedt zij inzicht in ervaringen met alternatieve professionalisering strategieën.

Judith Metz

2012-03-01

162

The ALS Gun Electronics system  

International Nuclear Information System (INIS)

The ALS Gun Electronics system has been designed to accommodate gun with a custom made socket and high speed electronics circuit which is capable of producing single and multiple electron bunches with time jitters measured at better than 50 PS. The system generates the gated RF signal at ground level before sending it up to the 120 KV-biased gun deck via a fiber optic cable. The current pulse width as a function of grid bias, using an Eimac 8847A planar triode simulating an electron gun, was measured to show the relationship between the two parameters

163

Dichtung als Blüte der Wahrheit  

Directory of Open Access Journals (Sweden)

Full Text Available Kaum eine andere Schriftstellerin hat so konsequent – man ist versucht, zu sagen: so ernsthaft – mit fremden Identitäten gespielt wie Else Lasker-Schüler, die sich selbst als Tino von Bagdad oder Prinz Jussuf von Theben imaginierte und ihren Freunden erfindungsreiche Namen beilegte. Realität und Phantasie flossen in ihrem Leben und Werk stets zusammen. Sigrid Bauschinger, ehemalige Professorin an der University of Massachusetts und bereits 1980 mit einer umfangreichen Studie über Else Lasker-Schüler hervorgetreten (Else Lasker-Schüler. Ihr Werk und ihre Zeit, hat es nun unternommen, auf Grundlage bisher unveröffentlicher Dokumente eine neue Biographie der bedeutenden Wuppertaler Autorin zu verfassen.

Susanne Gramatzki

2006-03-01

164

Bioética frente al paciente moribundo  

Scientific Electronic Library Online (English)

Full Text Available Se realizó un estudio descriptivo, retrospectivo y transversal en el Servicio de Cuidados Intermedios del Hospital Clinicoquirúrgico "Dr. Ambrosio Grillo Portuondo" de Santiago de Cuba, con el objetivo de analizar la aplicación de la bioética frente al paciente moribundo. El universo estuvo constitu [...] ido por 42 fallecidos en el segundo semestre de 1996. Las principales causas de muerte fueron las neumopatías inflamatorias y los accidentes vasculares encefálicos, con predominio de los varones mayores de 60 años; la mayoría de los enfermos al fallecer tenía pérdida de la conciencia, no siempre afectada por enfermedad; en uno de ellos por indicación facultativa al estar acoplado a ventiladores artificiales. La participación de la enfermera y la relación activopasiva, que es la fundamental en relación con el cumplimiento de los principios bioéticos, resultó positiva en todos los casos. Se actuó con beneficencia y justicia al respetar la autonomía del moribundo, donde el consentimiento informado desempeñó un papel importante, sin llegar a la práctica de la eutanasia en ninguna de sus variantes, ya que este proceder en nuestra sociedad implicaría un delito de homicidio. Abstract in english A descriptive, retrospective and cross-sectional study was conducted at the Service of Intermediate Care of the "Dr. Ambrosio Grillo Portuondo" Clinical and Surgical Hospital, in Santiago de Cuba, aimed at analyzing the application of bioethics in the dying patient. The universe was composed of 42 p [...] ersons that died in the second semester of l996. The main causes of death were the inflammatory lung diseases and the cerebrovascular accidents, with predominance of males over 60. On dying, most of the patients had lost conciousness, which was not always affected by the disease. One of them was coupled to artifical ventilators by facultative indication. The participation of the nurse and the active-passive relation , that is the fundamental in connection with the fulfillment of the bioethical principles, was positive in all cases. The moribund?s autonomy was respected and the reported consent played an important role. Euthanasia was not applied in any of its variants, since this procedure in our society will be considered as a homicide.

Laides, Luna Vázquez; Mariela, Valiente Duany; José Miguel, Goderich Lalán.

2000-08-01

165

Bioética frente al paciente moribundo  

Directory of Open Access Journals (Sweden)

Full Text Available Se realizó un estudio descriptivo, retrospectivo y transversal en el Servicio de Cuidados Intermedios del Hospital Clinicoquirúrgico "Dr. Ambrosio Grillo Portuondo" de Santiago de Cuba, con el objetivo de analizar la aplicación de la bioética frente al paciente moribundo. El universo estuvo constituido por 42 fallecidos en el segundo semestre de 1996. Las principales causas de muerte fueron las neumopatías inflamatorias y los accidentes vasculares encefálicos, con predominio de los varones mayores de 60 años; la mayoría de los enfermos al fallecer tenía pérdida de la conciencia, no siempre afectada por enfermedad; en uno de ellos por indicación facultativa al estar acoplado a ventiladores artificiales. La participación de la enfermera y la relación activopasiva, que es la fundamental en relación con el cumplimiento de los principios bioéticos, resultó positiva en todos los casos. Se actuó con beneficencia y justicia al respetar la autonomía del moribundo, donde el consentimiento informado desempeñó un papel importante, sin llegar a la práctica de la eutanasia en ninguna de sus variantes, ya que este proceder en nuestra sociedad implicaría un delito de homicidio.A descriptive, retrospective and cross-sectional study was conducted at the Service of Intermediate Care of the "Dr. Ambrosio Grillo Portuondo" Clinical and Surgical Hospital, in Santiago de Cuba, aimed at analyzing the application of bioethics in the dying patient. The universe was composed of 42 persons that died in the second semester of l996. The main causes of death were the inflammatory lung diseases and the cerebrovascular accidents, with predominance of males over 60. On dying, most of the patients had lost conciousness, which was not always affected by the disease. One of them was coupled to artifical ventilators by facultative indication. The participation of the nurse and the active-passive relation , that is the fundamental in connection with the fulfillment of the bioethical principles, was positive in all cases. The moribund?s autonomy was respected and the reported consent played an important role. Euthanasia was not applied in any of its variants, since this procedure in our society will be considered as a homicide.

Laides Luna Vázquez

2000-08-01

166

Het Rijksmuseum als historisch museum  

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Full Text Available Het vorig jaar heropende Rijksmuseum afficheert zich expressis verbis alsMuseum van Nederland. Het pretendeert ‘kunst, geschiedenis en mensente verbinden’ en doet dat aan de hand van voorwerpen die het museumsinds zijn oprichting verzamelt. Nadat enkele redactieleden van dit blad denieuwe presentatie hadden aanschouwd, speciaal met het oog op de manierwaarop kunst en geschiedenis in samenhang worden gepresenteerd, kwambij de redactie de behoefte op om het hoe en waarom van de Nederlandsegeschiedenis die ons in Cuypers’ zalen in de eenentwintigste eeuw wordtvoorgehouden, onder een professioneel historische loep te nemen.

Catrien Santing

2014-03-01

167

The Cd-Sb-Al system  

Energy Technology Data Exchange (ETDEWEB)

This study of the Cd-Sb-Al ternary system if of interest because of the cadmium and aluminum antimonides which have semiconductor properties and have found practical applications. The authors study the physicochemical interaction in the Cd-Sb-Al system along the following cuts: CdSb-Al-Sb, CdSb-Al, Cd-A-Sb, Cd /SUB 0.5/ -Sb-Al /SUB 0.2/ Cd /SUB 0.8/ , Cd/sub 3/Al-Sb, and CdAl/sub 3/-Sb. The projection to the liquidus of the Cd-Sb-Al system has been constructed. It was determined that the separation surface of aluminum antimonide occupies a large part of the diagram, in the field of which the stratification region is located.

Belotskii, D.P.; Kotsyumakha, M.P.; Lesina, L.V.; Lundich, N.S.; Makhova, M.K.; Noval' kovskii, N.F.

1985-12-01

168

Suicidio por salto al vacío  

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Full Text Available La tendencia al suicidio se asocia con problemas de soledad, abandono sicológico en la infancia, drogadicción, enfermedades graves, etc. Y en pacientes psiquiátricos es más común tras ser dados de alta. En Argentina los suicidios aumentaron en 25% de 1990 a 1992, y el 78 % de las víctimas fueron de sexo masculino. La proporción por salto al vacío aumentó , especialmente en áreas urbanas. En 40 casos argentinos hubo introducción basal del fémur (25%, fractura del calcáneo en 17%, fracturas de pelvis o cuello del fémur en 7% y estallido hepático en 20%.Suicidal tendencies are associated with loneliness, lack of psychological attention during childhood, drug addiction, serious illness, etc., In psyciatric patients, it is more frequent shortly after they are dismissed from the hospital. In Argentina, the suicide rate increased by 25% from 1990 to 1992, and 78% of the victims are males. The proportion that jumped to death increased, particularly inurban areas. In 40 Argentinian cases there was a basalpenetration of the femur (25%, fracture of the calcaneus bone (17%, fracture of pelvis o femur cervix (7% and explosion of the liver (20%.

Braulio Ernesto P. Linares

1995-05-01

169

Suicidio por salto al vacío  

Scientific Electronic Library Online (English)

Full Text Available SciELO Costa Rica | Language: Spanish Abstract in spanish La tendencia al suicidio se asocia con problemas de soledad, abandono sicológico en la infancia, drogadicción, enfermedades graves, etc. Y en pacientes psiquiátricos es más común tras ser dados de alta. En Argentina los suicidios aumentaron en 25% de 1990 a 1992, y el 78 % de las víctimas fueron de [...] sexo masculino. La proporción por salto al vacío aumentó , especialmente en áreas urbanas. En 40 casos argentinos hubo introducción basal del fémur (25%), fractura del calcáneo en 17%, fracturas de pelvis o cuello del fémur en 7% y estallido hepático en 20%. Abstract in english Suicidal tendencies are associated with loneliness, lack of psychological attention during childhood, drug addiction, serious illness, etc., In psyciatric patients, it is more frequent shortly after they are dismissed from the hospital. In Argentina, the suicide rate increased by 25% from 1990 to 19 [...] 92, and 78% of the victims are males. The proportion that jumped to death increased, particularly inurban areas. In 40 Argentinian cases there was a basalpenetration of the femur (25%), fracture of the calcaneus bone (17%), fracture of pelvis o femur cervix (7%) and explosion of the liver (20%).

Braulio Ernesto, P. Linares; Félix Antonio, Bikic.

1995-05-01

170

Bipolar characteristics of AlGaN/AlN/GaN/AlGaN double heterojunction structure with AlGaN as buffer layer  

International Nuclear Information System (INIS)

Highlights: •2DEG and 2DHG coexist in the AlGaN/AlN/GaN/AlGaN DH-structure. •The sheet densities of 2DEG and 2DHG vary with buffer Al content and GaN thickness. •The conditions for the disappearance of 2DHG are discussed. •Increasing buffer Al content provides better electron confinement. •Dislocation scattering is reduced in the DH-structure. -- Abstract: This is a theoretical study of AlGaN/AlN/GaN/AlGaN double heterojunction (DH) structure with AlGaN as buffer layer. Our calculation shows that as the buffer Al content increases, though two-dimensional electron gas (2DEG) sheet density decreases, the channel back-barrier caused by polarization-induced electric field in GaN provides better electron confinement. And under certain conditions the DH-structure shows bipolar characteristics, with an additional two-dimensional hole gas (2DHG) formed at GaN/AlGaN interface. The influence of the buffer Al content and GaN channel thickness on the 2DEG and 2DHG sheet densities are investigated, and the conditions for the disappearance of 2DHG are discussed. Also, the mobility inhibited by dislocation scattering is enhanced in DH-structure due to the enhancement of screening effect of the 2DEG

171

Elevated temperature compressive properties of reaction milled NiAl-AlN and Zr-doped NiAl-AlN composites  

Science.gov (United States)

Previous studies of a single lot of NiAl powder which had been ground under high intensity conditions in liquid nitrogen (cryomilling) indicated that this processing leads to a high strength, elevated temperature NiAl-AlN composite. Because this was the first known example of the use of the reaction milling process to produce a high temperature composite, the reproducibility of this technique was unknown. Two additional lots of NIAl powder and a lot of a Zr-doped NiAl powder have been cryomilled, and analyses indicate that AlN was formed within a NiAl matrix in all three cases. Compression testing between 1200 K and 1400 K has shown that the deformation resistance of these heats is similar to that of the first lot of NiAl-AlN; thus cryomilling can improve the creep resistance of NiAl by a factor of six. Based on this work, it is concluded that cryomilling of NiAl powder to form high temperature, high strength NiAl-AlN composites is a reproducible process.

Whittenberger, J. D.; Luton, Michael J.

1992-01-01

172

Analysis and chemometry of heavy metal concentrations in the Saale, Ilm and Unstrut as a basis for assessing the pollutant level and the prospects for success of sanitation measures. Final report; Analyse und chemometrische Bewertung von Schwermetallgehalten der Saale, Ilm und Unstrut als Bestandsaufnahme und zur Abschaetzung der Auswirkungen von Sanierungsmassnahmen. Abschlussbericht  

Energy Technology Data Exchange (ETDEWEB)

Since the mid-1980`s, heavy metal characterisation was carried out on sediments of selected sections of the river Saale and methodical work was done on the analysis of flowing water at the Friedrich Schiller University at Jena. However, there was no comprehensive and current information about the state of contamination along the whole course of the river before. The most important aim was therefore the first and current stocktaking of this extent of contamination of the water, sediment and suspended matter of the Saale. The basis of these considerations was formed by about 15,000 determined features in water samples and more than 1,000 examinations of suspended matter and 4,600 examinations of sediment. In the characterisation of contamination of flowing watercourses, it was generally usual to evaluate the change of individual features according to geographic or time aspects. The application of methods of multi-variate statistics makes it possible to identify anthropogenic and geogenic sources and to discover latent connections. A comprehensive evaluation of the actual contamination situation is possible in this way. (orig./SR) [Deutsch] Seit Mitte der achtziger Jahre werden an der Friedrich-Schiller-Universitaet Jena Schwermetallcharakterisierungen an Sedimenten ausgewaehlter Flussabschnitte der Saale sowie methodische Arbeiten zur Fliessgewaesseranalytik durchgefuehrt. Umfassende und aktuelle Informationen ueber den Belastungszustand entlang des gesamten Flussablaufes gab es jedoch bisher nicht. Wichtigstes Ziel war deshalb eine in diesem Umfang erstmalige und aktuelle Bestandsaufnahme zur Belastung von Wasser, Sediment und Schwebstoffe der Saale. Die Grundlage dieser Betrachtungen bilden ca. 15.000 bestimmte Merkmale in Wasserproben und mehr als 1.000 Schwebstoff- und 4.600 Sedimentuntersuchungen. Bei der Belastungscharakterisierung von Fliessgewaessern ist es derzeit allgemein ueblich, die Aenderung einzelner Merkmale nach geographischen oder zeitlichen Aspekten zu bewerten. Die Anwendung von Methoden der multivariaten Statistik ermoeglicht die Identifizierung anthropogener und geogener Quellen und die Aufdeckung latenter Zusammenhaenge. Damit ist eine umfassende Bewertung der tatsaechlichen Belastungssituation moeglich. (orig./SR)

Einax, J.W.; Truckenbrodt, D.; Kampe, O.

1997-09-01

173

SAP-like ultrafine-grained Al composites dispersion strengthened with nanometric AlN  

Energy Technology Data Exchange (ETDEWEB)

This paper reports the development of novel Sinter-Aluminum-Pulver (SAP)-like Al–AlN nanocomposites via replacing the native Al{sub 2}O{sub 3} thin films on fine Al powder with a large volume fraction of in situ formed nanometric AlN dispersoids. Fine gas-atomized Al powder (d{sub 50}=1.3 µm) compacts were first partially nitrided at 590 °C in flowing nitrogen, controlled by a small addition of Sn (0.3–0.4 wt%), and subsequently consolidated by hot direct extrusion. The resulting Al–AlN composites consisted of submicrometric Al grains reinforced with nanometric AlN dispersoids together with some nanometric Al{sub 2}O{sub 3} dispersoids. An Al–13 vol% AlN nanocomposite fabricated this way achieved exceptional ultimate tensile strength of 227 MPa, yield strength of 195 MPa and Young's modulus of 66 GPa at 300 °C, superior to typical SAP materials and coarse grained Al–AlN composites. In addition, the Al–13 vol% AlN nanocomposite exhibited good thermal stability up to 500 °C. The strengthening mechanism is discussed.

Balog, M., E-mail: martin.balog@savba.sk [Institute of Materials and Machine Mechanics, The Slovak Academy of Sciences, Racianska 75, 83102 Bratislava (Slovakia); The University of Queensland, School of Mechanical and Mining Engineering, ARC CoE for Design in Light Metals, Brisbane, Qld 4072 (Australia); Krizik, P. [Institute of Materials and Machine Mechanics, The Slovak Academy of Sciences, Racianska 75, 83102 Bratislava (Slovakia); Yan, M. [The University of Queensland, School of Mechanical and Mining Engineering, ARC CoE for Design in Light Metals, Brisbane, Qld 4072 (Australia); Simancik, F. [Institute of Materials and Machine Mechanics, The Slovak Academy of Sciences, Racianska 75, 83102 Bratislava (Slovakia); Schaffer, G.B. [The University of Queensland, School of Mechanical and Mining Engineering, ARC CoE for Design in Light Metals, Brisbane, Qld 4072 (Australia); Qian, M. [The University of Queensland, School of Mechanical and Mining Engineering, ARC CoE for Design in Light Metals, Brisbane, Qld 4072 (Australia); RMIT University, School of Aerospace, Mechanical and Manufacturing Engineering, GPO Box 2476, Melbourne, VIC 3001 (Australia)

2013-12-20

174

SAP-like ultrafine-grained Al composites dispersion strengthened with nanometric AlN  

International Nuclear Information System (INIS)

This paper reports the development of novel Sinter-Aluminum-Pulver (SAP)-like Al–AlN nanocomposites via replacing the native Al2O3 thin films on fine Al powder with a large volume fraction of in situ formed nanometric AlN dispersoids. Fine gas-atomized Al powder (d50=1.3 µm) compacts were first partially nitrided at 590 °C in flowing nitrogen, controlled by a small addition of Sn (0.3–0.4 wt%), and subsequently consolidated by hot direct extrusion. The resulting Al–AlN composites consisted of submicrometric Al grains reinforced with nanometric AlN dispersoids together with some nanometric Al2O3 dispersoids. An Al–13 vol% AlN nanocomposite fabricated this way achieved exceptional ultimate tensile strength of 227 MPa, yield strength of 195 MPa and Young's modulus of 66 GPa at 300 °C, superior to typical SAP materials and coarse grained Al–AlN composites. In addition, the Al–13 vol% AlN nanocomposite exhibited good thermal stability up to 500 °C. The strengthening mechanism is discussed

175

Aspectos Introductorios al Crédito Documentario  

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Full Text Available En el comercio internacional uno de los temas de mayor importancia para los agentes del mercado es la incorporación de mecanismos contractuales que les blinden de seguridad y garantía suficientes de que su contraparte cumplirá lo prometido. Las cartas de crédito contribuyen a ese propósito. Al crearse como mecanismos que confieren a ambas partes un alto grado de seguridad de que las condiciones pactadas en el contrato internacional, especialmente el de compraventa, serán cumplidas por cada una de las partes, todo, gracias a la participación o intermediación de una institución financiera, se constituyen en instrumentos necesarios para el normal desarrollo del comercio internacional. El presente texto estudia, a manera de introducción, el crédito documentario valiéndose de la abundante doctrina y jurisprudencia que en la materia se ha generado en el ámbito local e internacional alrededor de la figura.

Maximiliano Rodríguez Fernández

2009-07-01

176

Biodigestor: una aproximación al diseño  

Directory of Open Access Journals (Sweden)

Full Text Available EI estudio y evaluación de los Sistemas de Biogas forma parte de la Electiva Técnica "Sistemas Alternativos de Energía", ofrecida por la Facultad de Ingeniería. EI presente artículo es un producto de dicho curso e intenta ser informativo, estando centra do en el proceso del diseño preliminar. Las ecuaciones han sido extraídas de diversas fuentes y se pretende dar las pautas de evaluación técnica de cualquier Biodigestor, sin tocar los problemas prácticos y de experiencia que de ello se deriva. Agradezco la colaboración prestada por los estudiantes Guillermo Garcés y Pedro A. Cuervo y en especial al Ingeniero Arturo Martínez R. por su participación en la parte correspondiente a Biogas en el curso mencionado.

Julio Mario Rodríguez Devis

2011-11-01

177

Magnetic anisotropy of UFe6Al6  

International Nuclear Information System (INIS)

A comparative study of magnetization in UFe6Al6 and LuFe6Al6 single crystals gives clear evidence for the magnetic state of uranium in UFe6Al6. Both compounds exhibit the easy-plane type of magnetic anisotropy, however, the anisotropy energy in UFe6Al6, characterized by the anisotropy constants K1=-7.3 MJ m-3 and K2=-1.25 MJ m-3 at 2 K, exceeds by an order of magnitude that in LuFe6Al6. Anisotropy within the easy plane in the ferromagnetic state and anisotropy in the paramagnetic range, both absent in LuFe6Al6, are observed in UFe6Al6.

178

Transient oxidation of Al-deposited Fe-Cr-Al alloy foil  

Energy Technology Data Exchange (ETDEWEB)

The oxide phases formed on an Al-deposited Fe-Cr-Al alloy foil and an Fe-Cr-Al alloy foil of the same levels of Al and (La+Ce) contents, and their oxidation kinetics have been studied in air at 1173 and 1373 K using TGA, XRD and SEM. Al deposition promotes the growth of metastable aluminas ({theta}-Al{sub 2}O{sub 3}, {gamma}-Al{sub 2}O{sub 3}). Scales consisting of {theta}-Al{sub 2}O{sub 3} and a small amount of {alpha}-Al{sub 2}O{sub 3} develop on the Al-deposited foil at 1173 K and exhibit the whisker-type morphology. In the early stage of oxidation at 1373 K, thick scales consisting of {theta}-Al{sub 2}O{sub 3} and {alpha}-Al{sub 2}O{sub 3} grow rapidly on the Al-deposited foil. The transformation from {theta}-Al{sub 2}O{sub 3} to {alpha}-Al{sub 2}O{sub 3} is very fast, and the scales result in only {alpha}-Al{sub 2}O{sub 3}. In contrast, {alpha}-Al{sub 2}O{sub 3} scales containing a minor amount of FeAl{sub 2}O{sub 4} develop on the alloy foil. The growth rate of {alpha}-Al{sub 2}O{sub 3} scales on the Al-deposited foil is smaller than that on the alloy foil and very close to that on NiAl at 1373 K. (orig.) 13 refs.

Andoh, A. [Nisshin Steel Co., Ltd., Osaka (Japan). Steel and Technol. Dev. Lab.; Taniguchi, S.; Shibata, T. [Dept. of Materials Science and Processing, Osaka Univ. (Japan)

1997-12-31

179

Reactive Plasma Spraying of Fine Al2O3/AlN Feedstock Powder  

Science.gov (United States)

Reactive plasma spraying (RPS) is a promising technology for in situ formation of aluminum nitride (AlN) coatings. Recently, AlN-based coatings were fabricated by RPS of alumina (Al2O3) powder in N2/H2 thermal plasma. This study investigated the feasibility of RPS of a fine Al2O3/AlN mixture and the influence of the plasma gases (N2, H2) on the nitriding conversion, and coating microstructure and properties. Thick AlN/Al2O3 coatings with high nitride content were successfully fabricated. The coatings consist of h-AlN, c-AlN, Al5O6N, ?-Al2O3, and a small amount of ?-Al2O3. Use of fine particles enhanced the nitriding conversion and the melting tendency by increasing the surface area. Furthermore, the AlN additive improved the AlN content in the coatings. Increasing the N2 gas flow rate improved the nitride content and complete crystal growth to the h-AlN phase, and enhanced the coating thickness. On the other hand, though the H2 gas is required for plasma nitriding of the Al2O3 particles, increasing its flow rate decreased the nitride content and the coating thickness. Remarkable influence of the plasma gases on the coating composition, microstructure, and properties was observed during RPS of the fine particles.

Shahien, Mohammed; Yamada, Motohiro; Yasui, Toshiaki; Fukumoto, Masahiro

2013-12-01

180

Orientation of Al3Ti platelets in Al-Al3Ti functionally graded material manufactured by centrifugal method  

International Nuclear Information System (INIS)

Al-Al3Ti functionally graded materials (FGMs) were manufactured by the centrifugal method with a commercial ingot of Al-5 mass% Ti master alloy. The alloy was melted at a liquid/solid coexisting temperature, at which Al3Ti remains as a solid, and then it was cast into a thick-walled ring. It was found that the Al-Al3Ti functionally graded material can be successfully fabricated by the centrifugal method. It was also found that the volume fraction of the Al3Ti can be increased by repetition of the centrifugal method. Since the shape of Al3Ti particles in a commercial alloy ingot is that of a platelet, the Al3Ti particles are arranged with their platelet planes nearly perpendicular to the radial direction. The orientation effects become stronger when the G number becomes larger. Although the final centrifugal casting was conducted under a very large centrifugal force for the specimen cast three times, the orientation effects were weaker than those in the specimen cast one time. From these observations, it is concluded that the origin of orientation of Al3Ti platelets can be attributed to the angular velocity gradient of the melt along the radial direction produced by the difference in the viscosity. (orig.)

181

Influence of modifier on base Al and Si on structure and elongation Al-7%Si alloy  

OpenAIRE

A homogenous modifier with Al and Si obtained by the rapid solidification at a cooling rate equal to v=200 K/s was applied to the modification of the Al-7%Si alloy. The different modifiers were obtained by means of the Al-Si alloys. The components Al, Al-7%Si and Al-12%Si were put into crucible containing the liquid Al-7%Si alloy and kept for one minute to obtain a new homogenous alloy which after break-up was homogenous modifier. Both, effect of cooling rate applied to obtain modifier and we...

Lipin?ski, T.

2008-01-01

182

Joining of Al-Al micro foils by ultrasonic friction welding  

International Nuclear Information System (INIS)

The ultrasonic friction welding (UFW) method was employed to realize the joining of 20-25 ?m thick Al-Al foils without the introduction of difference to parents materials, since the conventional UFW puts more focus on large scale of bulk metal materials. The monomer and post-joining Al foils were analyzed and compared including surface roughness, thickness uniformity, and interface characteristics by using white light interfere profiler (WLI), optical microscope (OM) and scanning electron microscope (SEM). The experimental results indicate that the high quality Al-Al foils components and one kind of Al-Al device are well prepared by our improved UFW. (authors)

183

Ab initio molecular dynamics of Al irradiation-induced processes during Al(2)O(3) growth  

OpenAIRE

Al bombardment induced structural changes in alpha-Al(2)O(3) (R-3c) and gamma-Al(2)O(3) (Fd-3m) were studied using ab initio molecular dynamics. Diffusion and irradiation damage occur for both polymorphs in the kinetic energy range from 3.5 to 40 eV. However, for gamma-Al(2)O(3)(001) subplantation of impinging Al causes significantly larger irradiation damage and hence larger mobility as compared to alpha-Al(2)O(3). Consequently, fast diffusion along gamma-Al(2)O(3)(001) gives rise to prefere...

Music, Denis; Nahif, Farwah; Sarakinos, Kostas; Friederichsen, Niklas; M Schneider, Jochen

2011-01-01

184

Ibn al-?Arab? and Ab? Yaz?d al-Bist?m?  

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Full Text Available Many Sufis appear in Ibn al-?Arab?’s al-Fut?h?t al-Makkiyya, a treatise in which the author puts forward his principal ideas. Ab? Yaz?d al-Bist?m? is mentioned in this work 143 times, more than any other Sufi. The present article seeks to examine Ibn al-?Arab?’s attitude toward his Sufi predecessor by considering al-Bist?mi’s personality as it appears in Ibn al-?Arab?, as well as Ibn al-?Arab?’s views on al-Bist?m?’s Sufi practice, his presence as a model of moral conduct and his mystical philosophical notions. Ibn al-?Arab? does not accept all the notions and statements expressed by al-Bist?m?. Sometimes he mitigates al-Bist?mi’s daring assertions and thus reveals his unfavorable attitude toward shatah?t. However, in some cases al-Bist?m?’s statements serve as corroboration for Ibn al-?Arab?’s theses.

Aparecen muchos sufíes en la obra de Ibn al-?Arab? al-Fut?h?t al-Makkiyya, un tratado en el que el autor presenta sus ideas principales. En esta obra se menciona a Ab? Yaz?d al-Bist?mi un total de 143 veces, más que a cualquier otro sufí. Este artículo tiene el propósito de examinar la actitud de Ibn al-?Arab? hacia su predecesor sufí considerando la personalidad de al-Bist?m? tal y como aparece en la obra de Ibn al-?Arab?, además de analizar las ideas de Ibn al-?Arab? sobre las prácticas al-Fut?h?t sufíes de al-Bist?m?, su presencia como modelo de conducta moral y sus ideas filosóficas místicas. Ibn al-?Arab? no acepta todas las ideas y declaraciones de al-Bist?mi. A veces suaviza sus afirmaciones más atrevidas y de esta manera revela su actitud negativa hacia šatah?t. Sin embargo, en algunos casos Ibn al-?Arab? se sirve de las afirmaciones de al-Bist?mi para corroborar sus tesis.

Abrahamov, Binyamin

2011-12-01

185

XAFS Study of the Al K-Edge in NaAlH4  

OpenAIRE

Al K-edge (1561.1 eV) XANES and EXAFS spectra of unoxidized NaAlH4, a hydrogen storage material, have been recorded in He atmosphere in a special in situ low-energy cell. The XANES spectrum of NaAlH4 is reported and compared to that of oxidized NaAlH4, thus illustrating the power of XANES spectroscopy as a quick qualitative check of the NaAlH4. For the EXAFS data, reliable fits of the Al K-edge spectra could be obtained when all scattering contributions, i.e., Al-H, Al-Na, and Al-Al, were inc...

Balde?, C. P.; Mijovilovich, A. E.; Koningsberger, D. C.; Eerden, A. M. J.; Smith, A. D.; Jong, K. P.; Bitter, J. H.

2007-01-01

186

Influences of Al particles on the microstructure and property of electrodeposited Ni-Al composite coatings  

Science.gov (United States)

Ni-Al composite coatings with different contents of Al microparticles were prepared from a conventional Watt bath. The influences of Al particle loadings in the bath on the surface morphology, composition, texture, grain size, microstrain, residual stress and anti-corrosion of the Ni-Al composite coating were investigated. The friction coefficients of the coatings at 200 °C were also evaluated by a pin-on-disctribometer. The results showed that the surface morphology of the coatings changed from pyramid + colonied structure to colonied structure with increasing Al particle loadings. The (2 0 0) preferred orientation for pure Ni coating evolved to random orientation with increasing Al particle loadings. The grain size obtained the minimum value of 72.28 nm at Al particle loading of 100 g/L and the microstrain of the coating increased with increasing the Al particle loadings. The incorporation of Al particles decreased the residual stress of the electro-deposited coating and all the coatings deposited at different Al particle loadings possessed low residual stress. As the Al particle loading increased, the anti-corrosion of the Ni-Al coatings increased owing to the combined effect of increasing Al content in the coatings and the texture evolution from (2 0 0) plane to (1 1 1) plane. The wear result suggested that the increasing Al particle content did not improve the wear performance of the Ni-Al composite coatings.

Cai, Fei; Jiang, Chuanhai

2014-02-01

187

[FTLD/ALS as TDP-43 proteinopathies].  

Science.gov (United States)

Frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS) often coexist in the same patients: FTLD/MND. However, it is unclear whether FTLD/MND can be distinguished from ALS or FTLD. TAR DNA binding protein 43 KDa (TDP-43) has been identified as the major component of the ubiquitin-positive inclusion bodies in ALS, FTLD, and FTLD/MND. On the basis of this finding, a new concept of neurodegenerative disorders, namely TDP-43 proteinopathy, has been proposed for these disorders. In ALS, more than 30 mutations of the TDP-43 gene have been identified. The clinical features and neuropathological findings of ALS with TDP-43 mutation are identical to those of sporadic ALS. Therefore, TDP-43 plays a primary role in the pathogenesis of ALS. In contrast, only few patients with FTLD phenotype have TDP-43 mutations. Therefore, we have speculated that TDP-43 does not play a primary role in the pathogenesis of FTLD. The analysis of distribution of TDP-43 inclusion bodies in ALS patients revealed that ALS has two subtypes: (1) limited in the motor neuron system and (2) extended into the frontotemporal lobe. Additionally, causative genes of familial FTLD/MND have not been mapped to TDP-43. These results suggest that FTLD/MND is a disease distinct from FTLD and ALS. PMID:21921552

Ishihara, Tomohiko; Ariizumi, Yuko; Shiga, Atsushi; Yokoseki, Akio; Sato, Tatsuya; Toyoshima, Yasuko; Kakita, Akiyoshi; Takahashi, Hitoshi; Nishizawa, Masatoyo; Onodera, Osamu

2010-11-01

188

Electron momentum distribution and charge transfer study of FeAl, CoAl, and NiAl  

International Nuclear Information System (INIS)

Charge transfer and electron momentum distribution of transition metal alloys FeAl, CoAl, and NiAl are studied using the ?-ray Compton scattering technique. The results support the model where the charge transfer takes place from aluminium to the transition metal. A proper solid state calculation is, however, required in order to explain the details of the electronic properties of these alloys. (author)

189

Al-Si/Al2O3 in situ composite prepared by displacement reaction of CuO/Al system  

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Full Text Available Al2O3 particle-reinforced ZL109 composite was prepared by in situ reaction between CuO and Al. The microstructure was observed by means of OM, SEM and TEM. The Al2O3 particles in sub-micron sizes distribute uniformly in the matrix, and the Cu displaced from the in situ reaction forms net-like alloy phases with other alloy elements. The hardness and the tensile strength of the composites at room temperature have a slight increase as compared to that of the matrix. However, the tensile strength at 350 ? has reached 90.23 MPa, or 16.92 MPa higher than that of the matrix. The mechanism of the reaction in the CuO/Al system was studied by using of differential scanning calorimetry(DSC and thermodynamic calculation. The reaction between CuO and Al involves two steps. First, CuO reacts with Al to form Cu2O and Al2O3 at the melting temperature of the matrix alloy, and second, Cu2O reacts with Al to form Cu and Al2O3 at a higher temperature. At ZL109 casting temperature of 750–780 ?, the second step can also take place because of the effect of exothermic reaction of the first step.

Zhang Jing

2010-02-01

190

Insostenibilidad: aproximación al conflicto socioecológico  

Scientific Electronic Library Online (English)

Full Text Available SciELO Argentina | Language: Spanish Abstract in spanish La preocupación por el impacto humano sobre el entorno está documentada desde la Antigüedad. Situaciones de insostenibilidad han conducido en varios momentos de la historia a retrocesos en las condiciones de vida de la población. Si bien el impacto ambiental de las culturas preindustriales se encont [...] raba restringido fundamentalmente al ámbito local, con la revolución industrial las consecuencias de la presión sobre el medio ambiente crecieron exponencialmente, sobrepasando la localidad para alcanzar dimensiones globales. La búsqueda de un estadio o un desarrollo que sea sostenible implica la necesidad de comprender el conflicto socio-ecológico en su perspectiva histórica. Observamos que sus dimensiones básicas están presentes desde la etapa eotécnica hasta nuestros días. En el centro del debate se encuentra la necesidad de comprender la génesis de la ideología del progreso y del dominio de la naturaleza. La sostenibilidad es, en definitiva, una búsqueda compleja que implica una corrección de las causas de la insostenibilidad. La sensibilidad al riesgo y a la crisis de insostenibilidad se ha incrementado de forma considerable, en un momento en que se observa una cierta pérdida de legitimidad de la política representativa. La participación es, hoy más que nunca, uno de los imperativos de la búsqueda de la sostenibilidad. Abstract in english The concern about the human impact on the environment is documented since ancient times. Situations of unsustainability led at various times in history to setbacks in the living conditions of the population. While the environmental impact of preindustrial cultures was limited primarily to local leve [...] l, with the industrial revolution the consequences of the pressure on the environment grew exponentially, surpassing the locality to achieve global dimensions. The search for a sustainable stadium or development leads to the need to understand the socio-ecological conflict in its historical perspective. We note that their basic dimensions are present from the eotechnic phase until today. At the center of the debate is the need to understand the genesis of the ideology of progress and the domain of nature. Environmental conflicts in preindustrial cultures are often linked to agricultural production, waste from the activities of some guilds, sanitation problems in cities and energy demand. Sustainability is a complex search that involves a correction of the causes of unsustainability. Sensitivity to risk and to the unsustainability crisis has increased considerably, and a loss of legitimacy of representative politics is perceived. Participation is, more than ever, one of the imperatives of the search for sustainability.

Josep, Lobera.

2008-12-01

191

Insostenibilidad: aproximación al conflicto socioecológico  

Directory of Open Access Journals (Sweden)

Full Text Available La preocupación por el impacto humano sobre el entorno está documentada desde la Antigüedad. Situaciones de insostenibilidad han conducido en varios momentos de la historia a retrocesos en las condiciones de vida de la población. Si bien el impacto ambiental de las culturas preindustriales se encontraba restringido fundamentalmente al ámbito local, con la revolución industrial las consecuencias de la presión sobre el medio ambiente crecieron exponencialmente, sobrepasando la localidad para alcanzar dimensiones globales. La búsqueda de un estadio o un desarrollo que sea sostenible implica la necesidad de comprender el conflicto socio-ecológico en su perspectiva histórica. Observamos que sus dimensiones básicas están presentes desde la etapa eotécnica hasta nuestros días. En el centro del debate se encuentra la necesidad de comprender la génesis de la ideología del progreso y del dominio de la naturaleza. La sostenibilidad es, en definitiva, una búsqueda compleja que implica una corrección de las causas de la insostenibilidad. La sensibilidad al riesgo y a la crisis de insostenibilidad se ha incrementado de forma considerable, en un momento en que se observa una cierta pérdida de legitimidad de la política representativa. La participación es, hoy más que nunca, uno de los imperativos de la búsqueda de la sostenibilidad.The concern about the human impact on the environment is documented since ancient times. Situations of unsustainability led at various times in history to setbacks in the living conditions of the population. While the environmental impact of preindustrial cultures was limited primarily to local level, with the industrial revolution the consequences of the pressure on the environment grew exponentially, surpassing the locality to achieve global dimensions. The search for a sustainable stadium or development leads to the need to understand the socio-ecological conflict in its historical perspective. We note that their basic dimensions are present from the eotechnic phase until today. At the center of the debate is the need to understand the genesis of the ideology of progress and the domain of nature. Environmental conflicts in preindustrial cultures are often linked to agricultural production, waste from the activities of some guilds, sanitation problems in cities and energy demand. Sustainability is a complex search that involves a correction of the causes of unsustainability. Sensitivity to risk and to the unsustainability crisis has increased considerably, and a loss of legitimacy of representative politics is perceived. Participation is, more than ever, one of the imperatives of the search for sustainability.

Josep Lobera

2008-12-01

192

interna y al diálogo transcultural  

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Full Text Available Inspirado en los conceptos de An-Na´im (1995 del discurso interno y el diálogo transcultural, este artículo está focalizado en el análisis de dos herramientas que usan los practicantes de derecho y los usuarios del Consultorio Jurídico Rural de Fredonia (Antioquia durante su interacción y que, de ser estimuladas adecuadamente, pueden derivar no solo en procesos pedagógicos de refl exión sobre presupuestos fundamentales en materia de derechos, sino que también pueden llegar a constituirse en estrategias que permitan la actualización de las expectativas de los propios sujetos frente a su cultura. Para el caso de los practicantes, se explora en el tránsito entre dos lenguajes, uno eminentemente jurídico y otro coloquial, donde se da un acercamiento al lenguaje y valores de los consultantes. Ya en lo que atañe a los usuarios del Consultorio Jurídico, el análisis se construye en torno a la red local de consejos, pieza clave a partir de la cual se articulan ideas y valores de los actores sobre su entorno, pero donde el hilo conductor es la intención de resolver un confl icto por la vía jurídica.

Silvia Monroy \\u00C1lvarez

2007-01-01

193

Reply to Vance et al.  

Energy Technology Data Exchange (ETDEWEB)

In our report of a family with a motor and sensory polyneuropathy that was linked to chromosome 3q, we classified this neuropathy as a form of hereditary motor and sensory neuropathy II (HMSN II, also known as {open_quotes}CMT2{close_quotes}). Doubts have been raised by Vance et al. as to whether this neuropathy should be classified as hereditary sensory autonomic neuropathy I (HSAN I) instead of HMSN II. While it is reasonable to raise such doubts, we believe that the neuropathy is best designated as HMSN II for the reasons described below. The group of disorders described as HSAN are characterized by primary or predominant involvement of sensory and autonomic neurons that fail to develop or that undergo atrophy and degeneration. These disorders were extensively reviewed by Dyck and Ohta, who initially described them as the hereditary sensory neuropathies (HSN). It was Dyck who subsequently suggested that these disorders be designated HSAN rather than HSN, because of the presence of autonomic involvement. 8 refs.

Woon-Chee Yee; Elliott, J.L; Kwon, J.M.; Goodfellow, P. [Washington Univ. School of Medicine, St. Louis, MO (United States)

1996-07-01

194

Memory effect of Al-rich AlN films synthesized with rf magnetron sputtering  

International Nuclear Information System (INIS)

Al-rich AlN thin film, which is deposited onto n-type Si substrate by radio frequency sputtering of Al target in an argon and N2 gas mixture, can exhibit a large memory effect as a result of charge trapping in the Al nanoparticles/nanoclusters embedded in the AlN matrix. For the metal-insulator-semiconductor structure with a 60 nm Al-rich AlN thin film, a voltage of -15 V applied to the metal electrode for 10-6 s causes a flatband voltage shift of ?1.5 V. Both electron trapping and hole trapping are possible, depending on the polarity of the applied voltage. In addition, whether the electron trapping or the hole trapping is the dominant process also depends on the charging time and the magnitude of the voltage. The Al-rich AlN thin films provide the possibility of memory applications with low cost

195

Influence of modifier on base Al and Si on structure and elongation Al-7%Si alloy  

Directory of Open Access Journals (Sweden)

Full Text Available A homogenous modifier with Al and Si obtained by the rapid solidification at a cooling rate equal to v=200 K/s was applied to the modification of the Al-7%Si alloy. The different modifiers were obtained by means of the Al-Si alloys. The components Al, Al-7%Si and Al-12%Si were put into crucible containing the liquid Al-7%Si alloy and kept for one minute to obtain a new homogenous alloy which after break-up was homogenous modifier. Both, effect of cooling rate applied to obtain modifier and weight in weight modifier concentration in the melt on structure and elongations of Al-7%Si alloy are determined. A structural, and elongations resulting from the Al-7%Si alloy treatment by modifiers are studied in details.

T. Lipi?ski

2008-08-01

196

High pressure studies of UFe5Al7 and UFe7Al5 actinide compounds  

International Nuclear Information System (INIS)

The ternary inter-metallic compounds, UFe5Al7 and UFe7Al5, crystallize in a tetragonal ThMn12 type structure. In the as-cast samples a residual phase of FeAl (?2%wt) was identified in the grain boundaries. The amount of the residual cubic phase of FeAl was determined by Rietveld analysis and reduced by the annealing process. UFe5Al7 and UFe7Al5 maintain the tetragonal symmetry as a function of pressure, while FeAl keeps the cubic structure as was determined by the Rietveld analysis. The volume-pressure curve calculated from the X-ray analysis gives V/V0=0.87 for UFe5Al7 at 26.0 GPa and 0.89 at 24.6 GPa for UFe7Al5. (author)

197

Electron channelling enhanced microanalysis on Ni-Al-Mn and Al-Mn-Si  

International Nuclear Information System (INIS)

Atom location by channelling enhanced microanalysis (ALCHEMI) was performed for Ni-Al-Mn compounds and Al-Mn-Si quasicrystals. For Ni75Al25-xMnx (x=5,9) with the L12-type structure, an occupation fraction of Mn atoms at the Ni site was quantitatively determined using planar channelling conditions. The occupation fraction increases with the Mn concentration or by quenching the compound from high temperature. In quasicrystals of Al74Mn20Si6 and Al68Mn20Ru8Si4, axial channelling conditions were used to locate Si and Ru, respectively. It was shown that Si atoms occupy the Al site in Al74Mn20Si6 whereas Ru atoms occupy the site different from that of Al in Al68Mn20Ru8Si4. (author)

198

Synthesis and characterization of TiAl/?-Al2O3 nanocomposite by mechanical alloying  

International Nuclear Information System (INIS)

TiAl/?-Al2O3 nanocomposite was synthesized by mechanical alloying of the Al and TiO2 powder mixture. The powder particles were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). It was found that the mechanochemical reaction between Al and TiO2 gradually took place through intermediate stages during milling, resulted in the formation of disordered fcc-TiAl and Al2O3 phases. The in situ processing involved two steps in which diffusion of Ti into Al is prominent. Annealing of milled product led to transition of metastable fcc-TiAl into equilibrium ?-TiAl. The crystallite size of phases in produced nanocomposite powder estimated to be about 50 nm.

199

The strengthening effect of Al atoms into Mg-Al alloy: A first-principles study  

International Nuclear Information System (INIS)

To investigate the strengthening effect of Al atoms into Mg-Al alloy, the tensile and fracture processes of three supercell models Mg54, Mg53Al and Mg51Al3(I) were simulated using first-principles calculations. These simulations present directly the strain-stress relationships and the ideal tensile strengths for three models. The results show that the ideal tensile strength for Mg51Al3(I) noticeably increases but slightly drops for Mg53Al, compared with Mg54. By means of charge density and density of states analyses, we find that for Mg51Al3(I), Al atom on the (0 0 0 1) plane draws many electrons from neighbouring Mg atoms, leading to the formation of strong covalent bond between Al and Mg.

200

Tensile Behavior of Al2o3/feal + B and Al2o3/fecraly Composites  

Science.gov (United States)

The feasibility of Al2O3/FeAl + B and Al2O3/FeCrAlY composites for high-temperature applications was assessed. The major emphasis was on tensile behavior of both the monolithics and composites from 298 to 1100 K. However, the study also included determining the chemical compatibility of the composites, measuring the interfacial shear strengths, and investigating the effect of processing on the strength of the single-crystal Al2O3 fibers. The interfacial shear strengths were low for Al203/FeAl + B and moderate to high for Al203/FeCrAlY. The difference in interfacial bond strengths between the two systems affected the tensile behavior of the composites. The strength of the Al203 fiber was significantly degraded after composite processing for both composite systems and resulted in poor composite tensile properties. The ultimate tensile strength (UTS) values of the composites could generally be predicted with either rule of mixtures (ROM) calculations or existing models when using the strength of the etched-out fiber. The Al2O3/FeAl + B composite system was determined to be unfeasible due to poor interfacial shear strengths and a large mismatch in coefficient of thermal expansion (CTE). Development of the Al2O3/FeCrAlY system would require an effective diffusion barrier to minimize the fiber strength degradation during processing and elevated temperature service.

Draper, S. L.; Eldridge, J. I.; Aiken, B. J. M.

1995-01-01

201

Aproximación crítica al Gobierno de Alvaro Uribe  

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Full Text Available Una aproximación crítica al gobierno de Álvaro Uribe Vélez constituye un aporte para leer las dimensiones de la crisis nacional en el entramado de la política y la economía. Resaltando los contextos internacionales más determinantes, al igual que los propósitos más significativos de la gestión del gobierno. Con un aserto conclusivo: Al colapso del Sistema económico se suma el colapso del modelo político.

RICARDO SANCHEZ

2003-06-01

202

Development and phase transformation of Al2O3 scales formed on Al-deposited Fe-Cr-Al alloy foil; Jochaku aluminium mekki Fe-Cr-Al gokin hakujo no Al2O3 himaku seicho kyodo  

Energy Technology Data Exchange (ETDEWEB)

The effects of Al deposition on formation of the Al2O3 scales and their phase transformation were studied by the oxidation test conducted at 1073 to 1373K in air, using an Al-deposited foil having almost the same composition as a Fe-2OCr-5Al alloy foil, where a 50 by 60mm specimen was exposed to heating/cooling cycles in an electrical furnace. The specimen was measured for its weight each time it was cooled to room temperature, to establish the oxidation curve. The major findings are described below. Metastable Al2O3 is easily formed on the Al-deposited foil, its transformation into the {alpha}-Al2O3 phase being slow. By contrast, scales mainly composed of {alpha}-Al2O3 is formed on the Al alloy film during the initial stage of the oxidation test. Al2O3 in the scales is transformed into the {gamma}, {gamma} + {theta}, {gamma} + {theta} + {alpha}, and {alpha}-Al2O3 phase with oxidation time. The transformation of the {theta} to {alpha}-Al2O3 phase is accompanied by formation of Fe(Cr, Al)2O4 on the Al-deposited foil and a Fe-based spinel oxide of FeAl2O4 on the alloy foil. 28 refs., 17 figs., 4 tabs.

Ando, A. [Nisshin Steel Co. Ltd., Tokyo (Japan); Taniguchi, S.; Shibata, T. [Osaka University, Osaka (Japan)

1998-09-30

203

27Al NMR measurement of fcc Al configurations in as-quenched Al85Ni11Y4 metallic glass and crystallization kinetics of Al nanocrystals  

International Nuclear Information System (INIS)

The crystallization of melt spun Al85Ni11Y4 ribbon has been studied through systematic heat treatment in the 200–550 °C temperature range using the techniques of nuclear magnetic resonance (NMR) spectroscopy, electrical resistivity, differential scanning calorimetry (DSC) and X-ray diffraction (XRD). 27Al NMR spectroscopy provides a direct and sensitive method for determining the atomic fraction of ?-Al and analysis of the ?-Al crystallization kinetics. NMR results revealed low concentrations (3.9 at.%) of ?-Al configuration in the as-quenched material and confirm that they have ?-Al short-range order. The ability of NMR to directly detect the ?-Al configuration in the as-quenched state is compared and contrasted with XRD. Volume fractions of ?-Al phase calculated from NMR are also compared and contrasted with that calculated from XRD for samples subjected to isothermal annealing. Qualitative and quantitative agreement between the two techniques is found after the XRD fractions are corrected according to literature methods. Heat treatment at moderate temperatures (200 °C) is shown to result in transformation kinetics dominated by the growth of ?-Al consistent with heterogeneous nucleation, while higher temperatures (300 °C) lead to kinetics consistent with growth from homogeneous nucleation sites.

204

Ternary invariant point at 374°C in the three phase region AlSb-Al-Zn inside the Al-Sb-Zn ternary system  

OpenAIRE

Al-Sb-Zn ternary system was investigated in the three phase region Al-AlSb-Zn, using differential thermal analysis (DTA), differential scanning calorimetry (DSC) and scanning electron microscope equipped with energy dispersive spectrometer (SEM-EDS). The position and temperature of the invariant eutectic L ? AlSb + ?-Al + ? - Zn point inside Al-AlSb-Zn region was experimentally determined. To confirm the obtained results X-ray powder diffraction analysis or XRD was also done. All re...

Klan?nik G.; Medved J.

2011-01-01

205

Processing and mechanical properties of directionally solidified NiAl/NiAlTa alloys  

International Nuclear Information System (INIS)

Promising creep strengths were found for a directionally solidified NiAl-NiAlTa alloy when compared to other NiAl based intermetallics. The directionally solidified alloy had an off-eutectic composition that resulted in microstructures consisting of NiAl dendrites surrounded by aligned eutectic regions. The room temperature toughness of the two phase alloy was similar to that of polycrystalline NiAl even with the presence of the brittle Laves phase NiAlTa. Alloying additions that may improve the room temperature toughness by producing multiphase alloys are discussed

206

Sterol Biosynthesis Inhibition by Paclobutrazol Induces Greater Aluminum (Al) Sensitivity in Al-Tolerant Rice  

OpenAIRE

Al tolerance is one of the main growth and yield limiting factor in world and mechanism for Al-tolerance or Al-sensitivity yet to be clarified. We previously reported Japonica rice (Oryza sariva L.) cultivar Rikuu-20 as Al-sensitive, whereas a closely related cultivar that is a descendant of Rikuu-20, Rikuu-132, was Al tolerant. The objective of the present study was to clarify the role of plasma membrane lipid layer for Al tolerance in rice. The previously stated two cultivars were co...

Tawaraya, K.; Akhter, A.; Wagatsuma, T.; Khan, M. S. H.

2009-01-01

207

Evaluation of Methods of Soldering AlSi and AlSi-SiC Particle Composite Al Foams  

Science.gov (United States)

The cellular structure and unique properties of aluminum foams are the reason of their numerous applications and interests in respect of their joining. The paper includes the characterization of the essence of properties and application of aluminum and aluminum composite foams, the limitations, and possibilities of their soldering. The aim of the research is the consideration of methods of soldering AlSi foams and AlSi-SiC composite foams, and the joint structure. EDS and XRD investigations of the AlSi-SiC composite foams' joints were done. The possibility of soldering AlSi9 foams and AlSi9-SiC composite foams using S-Bond 220 solder was confirmed, and higher tensile strength of the joint than the parent material was also ascertained

Nowacki, Jerzy; Moraniec, Kacper

2015-01-01

208

Composition and precipitation inhomogeneities in melt-spun Al-Cu and Al-Zn ribbons  

International Nuclear Information System (INIS)

Non-uniform distributions of solute content in the supersaturated ? Al matrix and inhomogeneous precipitation of metastable/stable phases have been studied in rapidly solidified Al-Cu and Al-Zn ribbons. Double peaked X-ray diffraction lines from the ? Al matrix were observed in three as-quenched Al-Cu alloys and one annealed Al-Zn alloy. For as-quenched Al-Cu ribbons, variations in composition, microstructure and precipitate density across the ribbons results from local differences in coolingrates. These differences originate from recalescence during the solidification. The double peaked diffraction lines for these alloys corresponds to two compositions of the ? Al phase with less copper solute in the topside than in the wheelside of the ribbons. Subsequently, annealing of the samples leads to inhomogeneous precipitation of the metastable ?' phase across the whole thickness of the ribbons. Such inhomogeneities do not appear in as-quenched Al-Zn alloys which are quenched into a single ? Al phase. Splitting of the diffraction lines in the annealed ribbons arises from differences in the composition of two different ? Al matrix phases. The ? Al phase between the R phase lamellae has low zinc content, while the ? Al phase where high densities of G.P. zones are retained has higher zinc concentration. (orig.)

209

Preparation and Thermoelectric Properties of YbAl3 Thermoelectric Materials with Excessive Al  

Science.gov (United States)

A method to prepare YbAl3 sample with an accurate stoichiometric ratio has been developed by a melting, quenching, annealing and spark plasma sintering (SPS) method. A series of YbAl3 thermoelectric materials with nominal compositions YbAl3+x (x = 0-0.3, ?x = 0.1) have been prepared using the method. We have explored the effects of the excessive Al on phase compositions, microstructure and transport properties. The quenched samples are composed of YbAl3, YbAl2, Yb, and Al. All the annealed samples are composed of main phase YbAl3 and a trace of Al; some annealed samples with x = 0 and x = 0.1 still contain a trace of YbAl2. The SPSed samples with x ? 0.1 are composed of single-phase YbAl3, though a trace of YbAl2 still occured in the SPSed sample with x = 0. The electrical conductivity, Seebeck coefficient, power factor, thermal conductivity and ZT values are first increased with increasing x in the range of 0-0.2 and then decreased when x > 0.2. These thermoelectric properties evolutions originate from the change of densities and chemical composition induced by the excessive Al. The highest ZT value reaches 0.28 at 300 K for the SPSed sample with x = 0.2.

He, Dan-qi; Zhao, Wen-Yu; Mu, Xin; Zhou, Hong-yu; Zhang, Qing-jie

2015-01-01

210

Al compositional inhomogeneity of AlGaN epilayer with a high Al composition grown by metal-organic chemical vapour deposition  

International Nuclear Information System (INIS)

The Al compositional distribution of AlGaN is investigated by cathodoluminescence (CL). Monochromatic CL images and CL spectra reveal a lateral Al compositional inhomogeneity, which corresponds to surface hexagonal patterns. Cross-sectional CL images show a relatively uniform Al compositional distribution in the growth direction, indicating columnar growth mode of AlGaN films. In addition, a thin AlGaN layer with lower Al composition is grown on top of the buffer AlN layer near the bottom of the AlGaN epilayer because of the larger lateral mobility of Ga adatoms on the growth surface and their accumulation at the grain boundaries

211

Proton threshold states in 26Al  

International Nuclear Information System (INIS)

The energy levels of 26Al between Esub(x) = 6.3 and 6.5 MeV, corresponding to proton threshold energies in the 25Mg + p reaction from Esub(p) = 0 to 200 keV, have been investigated using the reactions 27Al(3He,?)26Al and 24Mg(3He,p)26Al. Despite early work reporting a doublet at Esub(x) = 6346 keV and Esub(x) = 6362 keV, most subsequent work reported a single state with conflicting spin and parity assignments. Our work clearly establishes the presence of the doublet and resolves the conflicts. We find that there are six states in this excitation energy region, including a new state at Esub(x) = 6410 +- 5 keV. The l-values leading to possible spin and parity assignments for all these states have been made using DWBA. We conclude however that only three of these six states may contribute to the production of 26Al by the 25Mg(p,?) reaction in the MgAl cycle and the new structure of 26Al reported here can substantially increase the production rate of 26Al in stellar reactions. (orig.)

212

High temperature deformation of Nb-18 Al  

International Nuclear Information System (INIS)

This paper reports on specimens of Nb-18 at.% Al, bend-tested at 20 degrees C, 1200 degrees C, and 1600 degrees C, and the deformed microstructures were characterized using TEM to determine phase distributions and slip systems. Material deformed at 20 degrees C showed brittle fracture and was characterized by large grains of a Nb-Al phase showing B2 ordering. Lamellar colonies of heavily dislocated massively transformed Nb3Al (A15) were present at grain boundaries. The slip system for dislocations in Nb3Al was determined to {100}/left-angle 001 right-angle, with defects typically extending in left-angle 011 right-angle directions. Fracture at 1200 degrees C was ductile, and TEM observations revealed a bcc Nb-Al(ss) matrix with second phase growth of Nb3Al and a-Al2O3. The Nb3Al phase contained total dislocations and slip-induced planar defects on {100} planes terminating in partial dislocations. In tilting experiments, the planar defects exhibited stacking fault contrast consistent with a displacement vector of R = a/4

213

Diana Al-Hadid: Identity and Heritage  

Science.gov (United States)

Diana Al-Hadid's sculptures reflect the many locations, cultures, histories, and mythologies that have shaped her as an artist. In large-scale works which have the appearance of architectural ruins, Al-Hadid employs imagery drawn from many diverse interests including science and technology, history, and literature. She also incorporates images and…

Jungerberg, Tom; Smith, Anna; Borsh, Colleen

2012-01-01

214

Bonding in CoAl and NiAl metal alloys using multipole and MEM techniques  

International Nuclear Information System (INIS)

The precise electron density distribution and bonding in metal alloys CoAl and NiAl is characterized using MEM (maximum entropy method) and multipole method. Reported X-ray single crystal data have been utilized for this purpose. Clear evidence of the metal bonding between the constituent atoms in these two systems has been obtained. The mid-bond electron densities in these systems are found to be 0.358 and 0.251 e/A3, respectively for CoAl and NiAl in the MEM analysis. The two-dimensional maps and one-dimensional electron density profiles have been constructed and analyzed. The thermal vibration of the individual atoms Co, Ni and Al has also been studied and reported. The contraction of atoms in CoAl and expansion of Ni and contraction of Al atom in NiAl is found from the multipole analysis, in line with the MEM electron density distribution

215

Grain refinement of cast Al alloys by Al-B master alloy  

Energy Technology Data Exchange (ETDEWEB)

The effects of boron on the grain refinement of Al alloys are investigated. Small addition of boron has no effects on the grain refinement of pure aluminum and Si free Al alloys. These alloys are, however, well grain-refined with low Si content of 0.1{proportional_to}0.5 mass%. The binary hypoeutectic Al-Si alloys are also refined by boron addition independently on the Si concentration. The grain refining effects are kept after long holding times, high holding temperature on the melt conditions and remelting. The boride particles in the Al-B master alloy do not act as effective nuclei of {alpha}-Al and it is doubtful whether the heterogeneous nucleation of {alpha}-Al occurs directly on AlB{sub 2}. The grain refinement mechanism should be focused on the reactions of Al-Si-B ternary system. (orig.)

Yaguchi, K. [Tokyo Inst. of Tech. (Japan). Dept. of Metallurgical Engineering; Tezuka, H.; Sato, T.; Kamio, A.

2000-07-01

216

De las fuentes al público  

Scientific Electronic Library Online (English)

Full Text Available SciELO Venezuela | Language: Spanish Abstract in portuguese A responsabilidade social do jornalista científico se inicia com a abordagem de suas fontes, passa pela redação de seu texto e termina com o impacto que este gera em sua audiência. Suas fontes são a matéria prima. Fazer as perguntas adequadas às fontes adequadas, para conseguir a informação que mais [...] se aproxime à realidade, é o desafio do jornalista que divulga a ciência. O texto discute os conceitos de verdade científica e verdade jornalística, e fala sobre as diferenças e as semelhanças entre científicos e jornalistas, para concluir fazendo uma reflexão ao exercício da reportagem em ciência, onde tanto as fontes como a necessidade de conhecer o perfil do público que tem acesso a nossa informação são elementos chave. Abstract in spanish La responsabilidad social del periodista científico se inicia con el abordaje de sus fuentes, pasa por la redacción de su texto y termina con el impacto que éste genera en su audiencia. Sus fuentes son la materia prima. Hacer las preguntas adecuadas a las fuentes adecuadas, para conseguir la informa [...] ción que más se acerque a la realidad, es el desafío del reportero que divulga la ciencia. El texto discute los conceptos de verdad científica y verdad periodística, y habla sobre las diferencias y las semejanzas entre científicos y periodistas, para concluir haciendo una reflexión al ejercicio de la reportería en ciencia, donde tanto las fuentes como la necesidad de conocer el perfil del público que tiene acceso a nuestra información son elementos clave. Abstract in english The social responsibility of the science journalist starts with the approach to the sources, runs through the writing of the text and ends with the impact that the latter generates in his audience. His sources are the raw material. The challenge of the reporter diffusing science is to make the adequ [...] ate questions to the adequate sources, in order to obtain the information that comes the closest to reality. The text discusses concepts of scientific truth and of journalistic truth, and deals with the similarities and differences between scientists and journalists, to conclude with a reflexion on the practice of reporting in science, where the sources as well as the need to know the profile of the public with access to our information, are key elements.

Lisbeth, Fog.

2002-02-01

217

Band Structure of AlSb Nanoclusters  

Directory of Open Access Journals (Sweden)

Full Text Available Ab initio restricted Hartree-Fock method within the framework of large unit cell formalism is used to investigate the band structure of AlSb nanoclusters. Large unit cells of 8, 16, 54, 64 and 128 atoms are used to analyze the cohesive energy, energy gap, valence bandwidth, and the density of states of the energy levels for AlSb nanoclusters. The results of the present work revealed that the band structure of AlSb nanoclusters differs significantly from that of the bulk AlSb crystal. Also, it is found that the valence band width and the cohesive energy (absolute value increase as the AlSb crystal size increases, and they tend to stabilize for nanoclusters of more than 50 atoms.

Haider I. Isa

2012-08-01

218

Threshold states in 26Al revisited  

International Nuclear Information System (INIS)

Threshold states in 26Al have been re-examined using the 27Al(3He,?)26Al and 25Mg(3He,d?)26Al reactions in order to resolve apparent ambiguities in some of the previously reported properties of these states. In particular, the s-wave resonance strength reported at E=37 keV is now found to be located at Esub(c.m.)=57.54 keV, and the proton width for the 374 keV resonance has been revised to GAMMAsub(p)=0.82 eV. These results have been used to calculate a new resonance strength of ??= 1.6 x 10-13 eV for the 57.54 keV resonance. As a result, the stellar production rate for 26Al is increased by a factor approx.=3-38 for temperatures T9=0.05-0.1. (orig.)

219

The wobbler mouse, an ALS animal model  

DEFF Research Database (Denmark)

This review article is focused on the research progress made utilizing the wobbler mouse as animal model for human motor neuron diseases, especially the amyotrophic lateral sclerosis (ALS). The wobbler mouse develops progressive degeneration of upper and lower motor neurons and shows striking similarities to ALS. The cellular effects of the wobbler mutation, cellular transport defects, neurofilament aggregation, neuronal hyperexcitability and neuroinflammation closely resemble human ALS. Now, 57 years after the first report on the wobbler mouse we summarize the progress made in understanding the disease mechanism and testing various therapeutic approaches and discuss the relevance of these advances for human ALS. The identification of the causative mutation linking the wobbler mutation to a vesicle transport factor and the research focussed on the cellular basis and the therapeutic treatment of the wobbler motor neuron degeneration has shed new light on the molecular pathology of the disease and might contribute to the understanding the complexity of ALS

Moser, Jakob Maximilian; Bigini, Paolo

2013-01-01

220

Kinetics of oxidation of Zn 5 Al and Zn 55 Al alloys alloyed by erbium  

International Nuclear Information System (INIS)

This article is devoted to influence of temperature and chemical composition on kinetics of oxidation of Zn 5 Al and Zn 55 Al alloys alloyed by erbium. The influence of temperature and chemical composition on kinetics of oxidation of Zn 5 Al and Zn 55 Al alloys alloyed by erbium is studied by means of thermogravimetry method with continuous samples weighing. Zinc, aluminium A 7 and its alloy with erbium (10%) are chosen as initial materials for alloys synthesis.

221

Spray forming of Al-Fe-Cr-Ti and Al-Si-Li alloys  

OpenAIRE

This work presents an investigation of the spray forming and downstream processing of Al alloys that are difficult to produce in bulk by conventional solidification processing: Al-Fe-Cr-Ti alloys for intermediate temperature applications and Al-Si-Li alloys for high stiffness, low density applications in fast moving machinery. For the Al-Fe-Cr-Ti alloys, spray forming is being investigated to allow the scale-up of alloy compositions previously explored only as ribbons or powders in traditiona...

Banjongprasert, C.; Hogg, Sc; Palmer, Ig; Grennan-heaven, N.; Stone, Ic; Grant, Ps

2007-01-01

222

Phase constituents of Al-rich U-Mo-Al alloys examined by transmission electron microscopy  

International Nuclear Information System (INIS)

To supplement the understanding of diffusional interactions involving Al-rich region of the U-Mo-Al system, alloys with composition 85.7Al-11.44U-2.86Mo and 87.5Al-10U-2.5Mo in at.%, were examined to determine the equilibrium phase constituents at 500 deg. C. These alloys were triple arc-melted, homogenized at 500 deg. C for 200 h, and water-quenched to preserve the high temperature microstructure. X-ray diffraction, scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (XEDS), and transmission electron microscopy (TEM) with high angle annular dark field (HAADF) imaging via scanning transmission electron microscopy (STEM) were employed for the characterization. Alloy specimens for TEM/STEM were prepared using site-specific focused ion beam (FIB) in situ lift-out (INLO) technique. Despite the homogenization time and temperature, five different phases, namely fcc-Al solid solution, cubic-UAl3, orthorhombic-UAl4, hexagonal-U6Mo4Al43 and diamond cubic-UMo2Al20, were observed. Based on U-Al, U-Mo and Al-Mo binary phase diagrams, previously proposed U-Mo-Al isotherms, and the solidification microstructure of these alloys, the Al-rich region of the equilibrium ternary isotherm at 500 deg. C was constructed. The fcc-Al solid solution, orthorhombic-UAl4, and diamond cubic-UMo2Al20 which were determined to be the equilibrium phases in 85.7Al-11.44 be the equilibrium phases in 85.7Al-11.44U-2.86Mo and 87.5Al-10U-2.5Mo alloys.

223

Thermal stability of TiAlN and nanocomposite TiAlSiN thin films.  

Science.gov (United States)

TiAlN and TiAlSiN coatings were synthesized by a cathodic arc deposition process. Titanium, Ti50Al50 alloy and AlSi (88 at.% of Al and 12 at.% of Si) alloy targets were adopted as the cathode materials. X-ray diffraction analyses revealed that Ti0.5Al0.5N and Ti49Al0.44Si0.07N possess a B1-NaCl crystal structure. The lattice constants of the Ti0.5Al0.5N and Ti0.49Al0.44Si0.07N calculated from XRD pattern were 0.418 nm and 0.422 nm, respectively. For the high temperature oxidation test, the coated samples were annealed at 900 degrees C in air atmosphere for 2 hours. In this study, the deposited Ti0.5Al0.5N had completely transformed to TiO2 and Al2O3, and Ti0.49Al0.44Si0.07N remained the as-deposited structure after oxidation treatment. It indicated that Ti0.49Al0.44Si0.07N possesses superior oxidation resistance than Ti0.5Al0.5N, due to the amorphous SiNx phase existed in the nanocomposite structure. The different oxidation mechanisms of Ti50Al50N and Ti0.49Al0.44Si0.07N at high temperature of 900 degrees C are developed in this study. PMID:19441466

Yang, Sheng-Min; Chang, Yin-Yu; Lin, Dong-Yih; Wang, Da-Yung; Wu, Weite

2009-02-01

224

The annealing behaviour of hydrogen implanted into Al metal and Al-Si alloy  

International Nuclear Information System (INIS)

In the present experiment, we have investigated how defects and elements as additive play a role as trap site by observing the annealing behaviour of hydrogen implanted into Al and Al-Si alloy. It was found that hydrogen is trapped as molecules in grain boundaries of Si in Al. (author)

225

Consolidation of Al2O3/Al Nanocomposite Powder by Cold Spray  

Science.gov (United States)

While the improvement in mechanical properties of nanocomposites makes them attractive materials for structural applications, their processing still presents significant challenges. In this article, cold spray was used to consolidate milled Al and Al2O3/Al nanocomposite powders as well as the initial unmilled and unreinforced Al powder. The microstructure and nanohardness of the feedstock powders as well as those of the resulting coatings were compared. The results show that the large increase in hardness of the Al powder after mechanical milling is preserved after cold spraying. Good quality coating with low porosity is obtained from milled Al. However, the addition of Al2O3 to the Al powder during milling decreases the powder and coating nanohardness. This lower hardness is attributed to non-optimized milling parameters leading to cracked particles with insufficient Al2O3 embedding in Al. The coating produced from the milled Al2O3/Al mixture also showed lower particle cohesion and higher amount of porosity.

Poirier, Dominique; Legoux, Jean-Gabriel; Drew, Robin A. L.; Gauvin, Raynald

2011-01-01

226

Al-?ar?qah al-Naqshaband?yah al-Kh?lid?yah f? Minangkabau: Dir?sat Makh???at al-Manhal al-‘Adhb? li Dhikr al-Qalb  

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Full Text Available This article provides new evidence that differs from the previous studies on the presence and dynamics of the teachings of Naqshabandiyah Khalidiyah sufi order in Minangkabau. The article shows that Naqshabandiyah Khalidiyah sufi order had come and develop in Minangkabau at the beginning of the 19th century through the east cost of West Sumatra under the influence and effort made by Shaykh Isma'il al-Khalidi al-Minangkabawi. This article therefore attempts to place Shaykh Isma'il al-Khalidi al-Minangkabawi in accordance with his role as the central figure of Naqshabandiyah sufi order in Minangkabau.Copyright (c 2014 by SDI. All right reserved.DOI: 10.15408/sdi.v18i2.435

Syofyan Hadi

2011-08-01

227

High temperature sulphide corrosion of TiAlNb and TiAlAg alloys  

International Nuclear Information System (INIS)

The sulfidation behaviour of binary Ti-48Al and ternary Ti-52Al-2Nb, Ti-51.2Al-5Nb, TI-48 Al-10Nb and Ti-45.9Al-15Nb (at%) alloys were studied in sulphur vapour atmosphere at 900 oC in the pressure range 10-1000 Pa. Binary TiAl and ternary TiAlNb TiAlAg intermetallic alloys were prepared by mechanical alloying (MA) process. After annealing at 1250 oC for 2 hrs in vacuum all three kinds of alloys were crystalline including two main phases ?-TiAl and ?2-Ti3Al with grain size in the range from about 0.2 to 1 ?m. Some amounts of ?-Ti, AlNb3 and Ag3Al were also detected. In the present study the influence of the niobium and silver additions to TiAl on the sulphidation kinetics, microstructure and chemical composition was investigated. Sulphidation of the TiAlNb and TiAlAg alloys in sulphur vapour atmosphere at 900 0C in the pressure range 10 - 1000n Pa followed parabolic or parabolic-linear rate law depending on the time of reaction. The amounts of sulfidation increased with increasing addition of niobium in the range from 2 - 15 at.%. In the case of Ti-49Al-2Ag alloy sulphidation kinetics was much faster in comparison with other alloy compositions, caused probably by an Ag-Al liquid phase formation. The sulphide scales formed on TiAlNb with 2 - 15 at.% of Nb and TiAl - 2 at.% Ag alloys had multi-layered structures of three different layers. It was observed that outermost sulphide layer is ricd that outermost sulphide layer is rich in Al2S3 with addition of some amount of Ti-sulphides and outer layer is rich in Ti-sulphides. The inner layer consisted of mixture of Ti-sulphides and Al2S3. Ti-sulphides were represented by TiS, Ti3S4, TiS2, Ti5S8 depending on the sulphidation conditions, p(S2) = 10-1000 Pa. The cross-sectional microstructure and phase composition of the reaction products were examined by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDS) and X-ray diffraction analysis (XRD). (author)

228

Low resistance Mo/Al/Mo/Au ohmic contact scheme to InAlN/AlN/GaN heterostructure  

Energy Technology Data Exchange (ETDEWEB)

Mo/Al/Mo/Au metallization scheme was investigated to develop low-resistance ohmic contacts on InAlN/AlN/GaN field-effect transistor heterostructure using a pre-metallization surface treatment with SiCl{sub 4} plasma in a reactive ion etching system and a relatively low-temperature anneal at 650 C. The contact resistance and specific contact resistivity were dramatically improved to as low as 0.15 {omega} mm and 7.8 x 10{sup -7}{omega} cm{sup 2} at 650 C, respectively. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Lee, Jaesun; Yan, Minjun; Ofuonye, Benedict; Jang, Jaehyung; Adesida, Ilesanmi [Micro and Nanotechnology Laboratory, Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, IL 61801 (United States); Gao, X. [Micro and Nanotechnology Laboratory, Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, IL 61801 (United States); IQE RF LLC, Somerset, NJ 08873 (United States); Guo, Shiping [IQE RF LLC, Somerset, NJ 08873 (United States)

2011-07-15

229

Strength of Al and Al-Mg/alumina bonds prepared using ultrahigh vacuum diffusion bonding  

International Nuclear Information System (INIS)

The authors have measured the cross-breaking strength of Al and Al-Mg alloys bonded with alumina. Diffusion bonding of Al and Al-Mg alloys requires significantly more bonding time than previously thought to obtain complete bonding. In contrast to previous diffusion bonding studies, fracture morphologies are similar to those obtained in bonds formed by liquid phase reaction; i.e., bonds are as strong or stronger than the ceramic; and fracture tends to propagate in the metal for pure Al and near the interface in the ceramic for the alloys. There are indications that the fracture morphology depends on Mg content and therefore on plasticity in the metal

230

Effects of hydrogen absorption in TbNiAl and UNiAl  

International Nuclear Information System (INIS)

Although hydrides of intermetallic compounds are used extensively as hydrogen-storage media, little is known about the exact nature of metal-hydrogen interactions. However, this knowledge is of essential importance for the understanding of thermodynamics and other properties. Hydrides (deuterides) of TbNiAl and UNiAl have been widely studied because of drastic increase of magnetic ordering temperature under hydrogenation. Here the authors report neutron-diffraction results of the three deuterides, TbNiAlD1.28, TbNiAlD0.8a nd UNiAlD2.23

231

Interdiffusion in Diffusion Couples: U-Mo v. Al and Al-Si  

International Nuclear Information System (INIS)

Interdiffusion and microstructural development in the U-Mo-Al system was examined using solid-to-solid diffusion couples consisting of U-7wt.%Mo, U-10wt.%Mo and U-12wt.%Mo vs. pure Al, annealed at 600 deg C for 24 hours. The influence of Si alloying addition (up to 5 wt.%) in Al on the interdiffusion microstructural development was also examined using solid-to-solid diffusion couples consisting of U-7wt.%Mo, U-10wt.%Mo and U-12wt.%Mo vs. pure Al, Al-2wt.%Si, and Al-5wt.%Si annealed at 550 deg C up to 20 hours. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electron probe microanalysis (EPMA) were employed to examine the development of a very fine multiphase intermetallic layer. In ternary U-Mo-Al diffusion couples annealed at 600 deg C for 24 hours, interdiffusion microstructure varied of finely dispersed UAl3, UAl4, U6Mo4Al43, and UMo2Al20 phases while the average composition throughout the interdiffusion zone remained constant at approximately 80 at.% Al. Interdiffusion microstructure observed by SEM/TEM analyses and diffusion paths drawn from concentration profiles determined by EPMA appear to deviate from the assumption of 'local thermodynamic equilibrium,' and suggest that interdiffusion occurs via supersaturated UAl4 followed by equilibrium transformation into UAl3, U6Mo4Al43, UAl4 and UMo2Al20 phases. Similar observation was made for U-Mo vs. Al diffusion couples annealed at 550 deg C. The addition of Si (up to 5 wt.%) in Al signe addition of Si (up to 5 wt.%) in Al significantly reduced the thickness of the intermetallic layer by changing the constituent phases of the interdiffusion zone developed in U-Mo vs. Al-Si diffusion couples. Specifically, the formation of (U,Mo)(Al,Si)3 with relatively large solubility for Mo and Si, along with UMo2Al20 phases was observed along with disappearance of U6Mo4Al43 and UAl4 phases. Simplified understanding based on U-Al, U-Si, and Mo-Si binary phase diagrams is discussed in the light of the beneficial effect of Si alloying addition.

232

The influence of Al content on the Zener relaxation of Fe-Al alloys  

International Nuclear Information System (INIS)

The effect of Al content on the Zener relaxation peak of annealed Fe-Al alloys has been investigated using a computer-controlled automatic inverted torsion pendulum through the method of free decay and forced vibration. It has been shown that alloys with medium Al contents show strong relaxation while lower or higher Al contents lead to relatively weak Zener relaxation peaks. The Zener relaxation in Fe-Al alloys originates from the next-nearest-neighbour atom pairs and their interaction rather than the nearest-neighbour atom pairs. The latter may not produce Zener relaxation because of the ordered structure, which suppresses Zener relaxation

233

Point defects in FeAl  

International Nuclear Information System (INIS)

Point defects in annealed B2-phase FeAl samples in the range 47-53 at.% Fe were studied using 57Fe Moessbauer spectroscopy. Spectra were analyzed using local environment models according to which point defects in atomic shells close to probe atoms induce shifts in the nuclear monopole interaction. For well-annealed samples, better results were obtained assuming only the presence of FeAl anti site and VFe vacancy defects, and not of AlFe antisite defects. Monopole interactions of 57Fe probes on the Fe and Al sublattices having no defects in the first two shells were about +0.27 and -0.03 mm s-1, respectively,with respect to Fe in ?-Fe metal. The shifts induced by FeAl and VFe defects in the first shells of Fe probes on the Fe and Al sublattices were -0.15 and -0.24 mm s-1, respectively, and, in the second shells, +0.06 and 0.011 mm s-1. In addition to structural defects needed to accommodate deviations from stoichiometry, annealed samples were found to contain several percents of FeAl and VFe defects due to lattice disorder, with greater disorder in Fe-deficient alloys

234

NiAl-Based microstructurally toughened composites  

Science.gov (United States)

Intermetallic NiAl-based composites with dramatically higher energy absorption capability and damage tolerance have been demonstrated. The approach consisted of incorporating continuous tubular 304 stainless steel toughening regions throughout the majority phase NiAl matrix. To compensate for the increase in density resulting from the 304 stainless steel, B4C particulate was added to the NiAl so that the overall composite density was within 5 pct of the value for monolithic NiAl. The notched Charpy impact energy absorption of the B4C/NiAl/304 stainless steel composites was in the range of 15 to 90 J/cm2, compared to a value of 0.8 J/cm2 for NiAl. The higher energies were measured on samples that deflected the crack front more extensively during failure. A model has been developed that is consistent with the energy absorption values measured during notched impact testing of the composites. Finally, significant room-temperature tensile strains (20 to 35 pct) were achieved due to constrained yielding of the 304 stainless steel, which prevented composite failure after the NiAl regions had cracked.

Nardone, Vincent C.; Strife, James R.

1991-01-01

235

Hot-electron drift velocity in AlGaN/AlN/AlGaN/GaN camelback channel  

International Nuclear Information System (INIS)

Nanosecond pulses were employed to study hot-electron transport in a nominally undoped Al0.33Ga0.67N/AlN/{Al0.1Ga0.9N/GaN} heterostructure where the mobile electrons are spread in a composite {Al0.1Ga0.9/GaN} dual channel exhibiting a camelback electron density profile at high electric fields. The highest velocity of ?1.6× 107 cm s?1 was obtained at electric field of 160 kV cm?1 in the channel with the electron density of 0.8 × 1013?cm?2 owing to its proximity to the LO-phonon–plasmon resonance. (fast track communication)

236

Reactivity of aluminum cluster anions with ammonia: Selective etching of Al11- and Al12-  

International Nuclear Information System (INIS)

Reactivity of aluminum cluster anions toward ammonia was studied via mass spectrometry. Highly selective etching of Al11- and Al12- was observed at low concentrations of ammonia. However, at sufficiently high concentrations of ammonia, all other sizes of aluminum cluster anions, except for Al13-, were also observed to deplete. The disappearance of Al11- and Al12- was accompanied by concurrent production of Al11NH3- and Al12NH3- species, respectively. Theoretical simulations of the photoelectron spectrum of Al11NH3- showed conclusively that its ammonia moiety is chemisorbed without dissociation, although in the case of Al12NH3-, dissociation of the ammonia moiety could not be excluded. Moreover, since differences in calculated Aln-+NH3 (n=9-12) reaction energies were not able to explain the observed selective etching of Al11- and Al12-, we concluded that thermodynamics plays only a minor role in determining the observed reactivity pattern, and that kinetics is the more influential factor. In particular, the conversion from the physisorbed Aln-(NH3) to chemisorbed AlnNH3- species is proposed b>3- species is proposed as the likely rate-limiting step.

237

Spin reorientation in Al/Metglas 2605S2/Al trilayers induced by magnetoelastic effect  

Science.gov (United States)

Mössbauer spectroscopy, in a broad temperature interval of 12-425 K, has been applied to investigate the spin reorientation dynamics caused by the temperature induced magnetoelastic effect on Al(x ?m)/Metglas 2605S2 (20 ?m)/Al(x ?m) trilayers (x =0; 2.5; 5 and 20). It was found that the angle between the average sample magnetization and gamma ray direction (perpendicular to the sample plane) depends on the Al layer thickness. For temperatures smaller than 260 K, saturation of spin reorientation, which can be controlled by adjusting the Al thickness, was reached for Al thicknesses larger than and equal to 5 ?m. For a 20 ?m Al thickness, changes in the F57e atom spin and charge densities have also been observed. A simple spin model has been proposed to describe qualitatively the spin reorientation effect as well as the influence of the Al thickness on the spin reorientation sensitivity.

Moscon, P. S.; Passamani, E. C.; Larica, C.; Takeuchi, A. Y.; Sánchez, F. H.; Zélis, P. Mendoza; Baggio-Saitovitch, Elisa

2008-09-01

238

Solar-blind ultraviolet AlInN/AlGaN distributed Bragg reflectors  

Science.gov (United States)

A 13.5-pair Al0.98In0.02N/Al0.77Ga0.23N distributed Bragg reflector (DBR) was grown by molecular beam epitaxy on an AlN template substrate. The DBR exhibited a peak reflectivity of 83.9% at 246 nm within the deep solar-blind ultraviolet region and a stopband width of 18 nm. The average refractive index contrast for the DBR was 9.25% at 246 nm, which is relatively high compared with that of a traditional Al(Ga)N/(Al)GaN DBR. Simulated results indicated that a 25.5-pair Al0.98In0.02N/Al0.77Ga0.23N DBR will provide a reflectivity higher than 99% and a 19 nm wide stopband with a center wavelength of 246 nm.

Zhang, Lili; Dong, Kexiu; Chen, Dunjun; Liu, Yanli; Xue, Junjun; Lu, Hai; Zhang, Rong; Zheng, Youdou

2013-06-01

239

Some aspects of anelastic and microplastic creep of pure Al and two Al-alloys  

Energy Technology Data Exchange (ETDEWEB)

Anelastic creep of pure Al, commercial Al-Cu and a binary Al-Cu alloy has been measured at room temperature by means of a high resolution laser interferometer. The irreversible component of the deformation was also quantified from measurements of the anelastic creep recovery. The dependence of the deformation-time curves on thermal treatment and cold work is analyzed. The mechanisms responsible for the room temperature anelastic creep are discussed. Materials loaded below their elastic limit can present either a pure anelastic behavior (commercial Al-Cu) or additional viscoelastic creep (pure Al, high purity Al-Cu). For commercial Al-Cu, the presence of an irreversible deformation appears to be mainly related to the state of the surface. A viscoelastic after effect has been measured for this alloy after a Cu-electroplating treatment. As a typical result for room temperature creep, the irreversible deformation depends logarithmically on load time. (orig.).

Sgobba, S. (Lab. de Metallurgie Mecanique, Dept. des Materiaux, Ecole Polytechnique Federale de Lausanne (Switzerland)); Kuenzi, H.U. (Lab. de Metallurgie Mecanique, Dept. des Materiaux, Ecole Polytechnique Federale de Lausanne (Switzerland)); Ilschner, B. (Lab. de Metallurgie Mecanique, Dept. des Materiaux, Ecole Polytechnique Federale de Lausanne (Switzerland))

1993-11-01

240

Some aspects of anelastic and microplastic creep of pure Al and two Al-alloys  

International Nuclear Information System (INIS)

Anelastic creep of pure Al, commercial Al-Cu and a binary Al-Cu alloy has been measured at room temperature by means of a high resolution laser interferometer. The irreversible component of the deformation was also quantified from measurements of the anelastic creep recovery. The dependence of the deformation-time curves on thermal treatment and cold work is analyzed. The mechanisms responsible for the room temperature anelastic creep are discussed. Materials loaded below their elastic limit can present either a pure anelastic behavior (commercial Al-Cu) or additional viscoelastic creep (pure Al, high purity Al-Cu). For commercial Al-Cu, the presence of an irreversible deformation appears to be mainly related to the state of the surface. A viscoelastic after effect has been measured for this alloy after a Cu-electroplating treatment. As a typical result for room temperature creep, the irreversible deformation depends logarithmically on load time. (orig.)

241

High quality AlGaN grown on ELO AlN/sapphire templates  

Science.gov (United States)

The defect structure and the homogeneity of 1-3 µm thick AlxGa1-xN layers grown on epitaxially laterally overgrown (ELO) AlN on patterned AlN/sapphire templates have been investigated in dependence on the miscut direction of the c-plane sapphire substrates, the etching depth into the sapphire and the Al concentration. It was found that shallowly etched AlN/sapphire templates with a 0.25° miscut toward the a-plane provide a smooth surface of ELO AlN and therefore a good Al homogeneity in the overgrown Al0.8Ga0.2N layer. The threading dislocation density in these layers is as low as 5×108 cm-2.

Zeimer, U.; Kueller, V.; Knauer, A.; Mogilatenko, A.; Weyers, M.; Kneissl, M.

2013-08-01

242

Oxidation of Al2O3 continuous fiber-reinforced/NiAl composites  

Science.gov (United States)

The 1200 C and 1300 C isothermal and cyclic oxidation behavior of Al2O3 continuous fiber-reinforced/NiAl composites were studied. Oxidation resulted in formation of Al2O3 external scales in a similar manner as scales formed on monolithic NiAl. The isothermal oxidation of an Al2O3/NiAl composite resulted in oxidation of the matrix along the fiber/matrix interface near the fiber ends. This oxide acted as a wedge between the fiber and the matrix, and, under cyclic oxidation conditions, led to further oxidation along the fiber lengths and eventual cracking of the composite. The oxidation behavior of composites in which the Al2O3 fibers were sputter coated with nickel prior to processing was much more severe. This was attributed to open channels around the fibers which formed during processing, most likely as a result of the diffusion of the nickel coating into the matrix.

Doychak, J.; Nesbitt, J. A.; Noebe, R. D.; Bowman, R. R.

1992-01-01

243

Suspected variables among Al Sufi stars.  

Science.gov (United States)

In the tenth century Al Sufi compiled a catalogue of some 1100 stars. J.E. Gore, around 1900, wrote extensively on the magnitudes of these stars. On intercomparing them with a few other catalogues, Gore surmised that some 38 stars appeared to show secular variations. Here all the Al Sufi magnitudes have been compared with numerous additional sources, but smooth secular variations are not substantiated although some stars seem to have undergone comparatively sudden changes after about 1600. About 70 Al Sufi stars are now named or suscpected variable stars, but nearly all with amplitudes under 0.3 V.

Hoffleit, D.

244

Ni{sub 3}Al aluminide alloys  

Energy Technology Data Exchange (ETDEWEB)

This paper provides a brief review of the recent progress in research and development of Ni{sub 3}Al and its alloys. Emphasis has been placed on understanding low ductility and brittle fracture of Ni{sub 3}Al alloys at ambient and elevated temperatures. Recent studies have resulted in identifying both intrinsic and extrinsic factors governing the fracture behavior of Ni{sub 3}Al alloys. Parallel efforts on alloy design using physical metallurgy principles have led to properties for structural use. Industrial interest in these alloys is high, and examples of industrial involvement in processing and utilization of these alloys are briefly mentioned.

Liu, C.T.

1993-10-01

245

MICROSTRUCTURE OF CVD - Al2O3  

OpenAIRE

The reaction mechanisms of CVD-Al2O3 are briefly reviewed. Two independent reaction paths exist, one of which is rate limited by a volume reaction and the second one by a surface reaction. Al2O3 crystallizes in several different phases. The ?-structure is the stable phase at normal deposition temperature (950-1050°C). The metastable ?-phase is the second most commonly occurring phase. It is shown that ? - and ? - Al2O3 nucleate on pure TiC (111) facets with well defined lattice orientati...

Chatfield, C.; Lindstro?m, J.; Sjo?strand, M.

1989-01-01

246

The effects of LT AlN buffer thickness on the optical properties of AlGaN grown by MOCVD and Al composition inhomogeneity analysis  

International Nuclear Information System (INIS)

We have investigated the growth of AlGaN epilayers on a sapphire substrate by metalorganic chemical vapour deposition using various low-temperature (LT) AlN buffer thicknesses. Combined scanning electron microscopy and cathodoluminescence investigations reveal the correlation between the surface morphology and optical properties of AlGaN films in a microscopic scale. It is found that the suitable thickness of the LT AlN buffer for high quality AlGaN growth is around 20 nm. The Al compositional inhomogeneity of the AlGaN epilayer is attributed to the low lateral mobility of Al adatoms on the growing surface

247

Crack-free thick AlGaN grown on sapphire using AlN/AlGaN superlattices for strain management  

Science.gov (United States)

We report on an AlN/AlGaN superlattice approach to grow high-Al-content thick n+-AlGaN layers over c-plane sapphire substrates. Insertion of a set of AlN/AlGaN superlattices is shown to significantly reduce the biaxial tensile strain, thereby resulting in 3-?m-thick, crack-free Al0.2Ga0.8N layers. These high-quality, low-sheet-resistive layers are of key importance to avoid current crowding in quaternary AlInGaN multiple-quantum-well deep-ultraviolet light-emitting diodes over sapphire substrates.

Zhang, J. P.; Wang, H. M.; Gaevski, M. E.; Chen, C. Q.; Fareed, Q.; Yang, J. W.; Simin, G.; Khan, M. Asif

2002-05-01

248

Evolution of deformation texture in Al/Al–Mg/Al composite sheets during cold-roll cladding  

International Nuclear Information System (INIS)

Highlights: ? Al/Al–Mg/Al composite sheets were fabricated by roll cladding. ? EBSD analysis captured the heterogeneity of deformation texture in each component layer. ? The deformation history from the FEA was used to simulate the evolution of deformation texture. ? The simulations revealed how the friction-induced shear component of Lij affects the development of shear–strain texture. - Abstract: Al/Al–Mg/Al composite sheets were fabricated by roll cladding to investigate the evolution of deformation texture through the thickness direction. Electron backscatter diffraction (EBSD) was used to analyze the heterogeneity of deformation texture in each component layer of the composite sheets. Finite element analysis (FEA) was conducted to simulate the deformation history in each component layer during roll cladding. The deformation history from the FEA was used in a full-constraints polycrystal model to simulate the evolution of deformation texture through the thickness direction during roll cladding. The simulation results revealed that the development of distinct shear–strain texture components in the clad layer could be explained by the friction-induced shear component of a velocity gradient tensor.

249

Sterol Biosynthesis Inhibition by Paclobutrazol Induces Greater Aluminum (Al Sensitivity in Al-Tolerant Rice  

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Full Text Available Al tolerance is one of the main growth and yield limiting factor in world and mechanism for Al-tolerance or Al-sensitivity yet to be clarified. We previously reported Japonica rice (Oryza sariva L. cultivar Rikuu-20 as Al-sensitive, whereas a closely related cultivar that is a descendant of Rikuu-20, Rikuu-132, was Al tolerant. The objective of the present study was to clarify the role of plasma membrane lipid layer for Al tolerance in rice. The previously stated two cultivars were compared to determine mechanisms underlying variations in Al tolerance. The sensitive cultivar Rikuu-20 showed increased permeability of the Plasma Membrane (PM and greater Al uptake within 24 h of Al treatment. Lipid composition of the PM differed between these cultivars was considered to be the primary account for the difference in Al tolerance. The tolerant cultivar Rikuu-132 showed a less PM permeabilization and Al accumulation which was drastically decreased in presence of paclobutrazol, a sterol metabolism inhibitor which reduces ?5-sterols and accumulates abnormal sterols by inhibiting obtusifoliol-14?-demethylase. The tolerant cultivar Rikuu-132 had lower phospholipids than that of sensitive cultivar Rikuu-20, suggesting that the PM of Rikuu-132 is less negatively charged and less permeabilized than that of Rikuu-20. We used inhibitor of ?5-sterol synthesis to alter the ratio of phospholipids to ?5-sterols in both cultivars. These inhibitors reduced Al tolerance in Rikuu-132 whereas Al tolerance of Rikuu-20 was unchanged suggesting that PM lipid composition greatly regulating Al tolerance in rice.

K. Tawaraya

2009-01-01

250

Electroforming and Ohmic contacts in Al-Al2O3-Ag diodes  

Science.gov (United States)

Electroforming of metal-insulator-metal (MIM) diodes is a non-destructive dielectric breakdown process that changes the diode from its initial high resistance state (HRS) to a low resistance state (LRS). After electroforming, resistance switching memories (RSMs) use voltages to switch from HRS to LRS and back. Many MIM combinations are proposed for use in RSMs. In many cases conduction in the LRS is nearly temperature independent at low temperatures; an Ohmic contact with a barrier to electron injection of ˜0 eV results from electroforming. Electroforming of Al-Al2O3-Ag diodes with amorphous anodic Al2O3 thicknesses between 12 and 41 nm has been studied. Two anodizing electrolytes have been used; 0.1 M ammonium pentaborate (bor-H2O) and a solution of 0.1 M of ammonium pentaborate per liter of ethylene glycol (bor-gly). Polarization of Al2O3 and negative charge in Al2O3 are much larger when Al2O3 is formed in bor-H2O solution than when Al is anodized in bor-gly solution. Electroforming of Al-Al2O3-Ag diodes results in an Ohmic contact at the Al-Al2O3 interface, voltage-controlled negative resistance (VCNR) in the current-voltage (I-V) characteristics, electroluminescence (EL), and electron emission into vacuum (EM) from filamentary conducting channels. Two distinct modes of electroforming occur for Al-Al2O3-Ag diodes. ?-forming occurs for 2.5 V ? VS ? 5 V, where VS is the applied voltage. It is characterized by an abrupt current jump with the simultaneous appearance of EL and EM. ?-forming occurs for VS ? 7 V. I-V curves, EL, and EM develop gradually and are smaller than for ?-forming. Electroforming occurs more readily for diodes with Al2O3 formed in bor-H2O that have greater defect densities. Fully developed I-V curves have similar VCNR, EL, and EM after ?-forming or ?-forming. A model is proposed in which excited states of F-centers, oxygen vacancies in amorphous anodic Al2O3, form defect conduction bands. Electroforming that results in an Ohmic contact requires injection of positive charge at the Al-Al2O3 interface. ?-forming is the result of ionization of F-center recombination centers with energies that are close to the Al Fermi level. Hole injection by high-field ionization of valence band states of Al2O3 causes ?-forming.

Hickmott, T. W.

2012-03-01

251

Interdiffusion in Diffusion Couples: U-Mo v. Al and Al-Si  

Energy Technology Data Exchange (ETDEWEB)

Interdiffusion and microstructural development in the U-Mo-Al system was examined using solid-tosolid diffusion couples consisting of U-7wt.%Mo, U-10wt.%Mo and U-12wt.%Mo vs. pure Al, annealed at 600°C for 24 hours. The influence of Si alloying addition (up to 5 wt.%) in Al on the interdiffusion microstructural development was also examined using solid-to-solid diffusion couples consisting of U-7wt.%Mo, U-10wt.%Mo and U-12wt.%Mo vs. pure Al, Al-2wt.%Si, and Al-5wt.%Si annealed at 550°C up to 20 hours. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electron probe microanalysis (EPMA) were employed to examine the development of a very fine multiphase intermetallic layer. In ternary U-Mo-Al diffusion couples annealed at 600°C for 24 hours, interdiffusion microstructure varied of finely dispersed UAl3, UAl4, U6Mo4Al43, and UMo2Al20 phases while the average composition throughout the interdiffusion zone remained constant at approximately 80 at.% Al. Interdiffusion microstructure observed by SEM/TEM analyses and diffusion paths drawn from concentration profiles determined by EPMA appear to deviate from the assumption of “local thermodynamic equilibrium,” and suggest that interdiffusion occurs via supersaturated UAl4 followed by equilibrium transformation into UAl3, U6Mo4Al43, UAl4 and UMo2Al20 phases. Similar observation was made for U-Mo vs. Al diffusion couples annealed at 550°C. The addition of Si (up to 5 wt.%) in Al significantly reduced the thickness of the intermetallic layer by changing the constituent phases of the interdiffusion zone developed in U-Mo vs. Al-Si diffusion couples. Specifically, the formation of (U,Mo)(Al,Si)3 with relatively large solubility for Mo and Si, along with UMo2Al20 phases was observed along with disappearance of U6Mo4Al43 and UAl4 phases. Simplified understanding based on U-Al, U-Si, and Mo-Si binary phase diagrams is discussed in the light of the beneficial effect of Si alloying addition.

D. D. Keiser, Jr.; E. Perez; B. Yao; Y. H. Sohn

2009-11-01

252

Analysis of mechanical properties of nanocrystalline Al+?-Al2O3 composites using molecular dynamics simulation  

International Nuclear Information System (INIS)

In this article, mechanical properties of nanocrystalline Al+?-Al2O3 composites are investigated using molecular dynamics simulations. The configurations of matrix and volume fraction of ?-Al2O3 may affect the mechanical properties of the particle reinforced metal-matrix composites and are taken into account. The potentials for the Al+?-Al2O3 system developed by Xin Lai et al. are adopted to depict the interactions between Al and ?-Al2O3. Monocrystal Al and Bicrystal Al based ?-Al2O3 particle reinforced nanocomposites are modelled respectively. Results show that: (1) volume fraction of the particles has no explicit effects on the elastic modulus and ultimate strength in both monocrystal Al and bicrystal Al based matrix nanocomposites, (2) disappearance of valley in the stress-strain curve of bicrystal Al results from existence of dislocation in matrix of various orientations.

253

RESPUESTA HIPERTENSIVA AL ESFUERZO EN PACIENTES PREHIPERTENSOS  

Directory of Open Access Journals (Sweden)

Full Text Available Se realizó un estudio descriptivo para conocer la respuesta hipertensiva al esfuerzo en pacientes prehipertensos atendidos en consulta externa de medicina interna de hospital "Manuel Ascunce Domenech" de Camagüey durante el año 2005. El universo ascendió a 40 pacientes, a los cuales se les aplicó una encuesta con variables según criterios bibliográficos: grupos de edades, factores de riesgo y respuesta hipertensiva al esfuerzo. Los datos se procesaron mediante el programa estadístico Microstat. El grupo de edad que predominó fue el de 35-52 años con el 45.7 %; los factores de riesgo que con mayor frecuencia se presentaron fueron el hábito de fumar y el antecedente patológico familiar de enfermedad cardiovascular prematura; la respuesta presora ligera al esfuerzo fue la más frecuente con el 59.37 % y se presentó en más de la mitad de los pacientes prehipertensos. Se observó que la respuesta hipertensiva al esfuerzo se asoció de manera significativa a factores de riesgo.

Tom\\u00E1s Noel Santana T\\u00E9llez

2007-01-01

254

The Al-B-Nb-Ti system  

International Nuclear Information System (INIS)

The thermodynamic description of the ternary system Al-B-Ti is obtained by modelling the Gibbs energy of all individual phases in the system using the CALPHAD approach. The model parameters have been evaluated using the computer optimization technique PARROT based on the available descriptions of the constituent binary systems Al-B, B-Ti and Al-Ti recently published and relevant experimental information on phase equilibria for the ternary system. For the ternary system Al-B-Ti the reaction scheme, projection of the liquidus, solidus and solvus surfaces, selected vertical and isothermal sections are calculated using the proposed thermodynamic description. An acceptable agreement between the calculations and experimental data is achieved

255

CALCULUL CINETOSTATIC AL MECANISMELOR PLANETARE CILINDRICE  

Directory of Open Access Journals (Sweden)

Full Text Available În lucrare se prezint? o metod? analitic? pentru calculul cinetostatic al mecanismului planetarmonomobil cu dou? ro?i din?ate centrale. Se consider? mai întâi cazul general al schemelor cinematice cu dou?ro?i din?ate solidare tip satelit, în dou? variante practice (multiplicator ?i reductor de tura?ie. Este men?ionatcazul particular al mecanismelor planetare cu o singur? roat? satelit cu angrenare dubl? (exterioar? ?iinterioar?. Pe baza modelului de analiz? cinetostatic? a mecanismului planetar monomobil cu dou? ro?i din?atecentrale, în finalul lucr?rii se abordeaz? o problem? practic? de calcul cinetostatic al unui mecanism planetarcilindric simplu folosit la capul de frezat pentru prelucrarea ro?ilor din?ate cilindrice cu din?i curbi înhipocicloid?.

P?un ANTONESCU

2012-05-01

256

Spin excitations in CePdAl  

Energy Technology Data Exchange (ETDEWEB)

The heavy-fermion compound CePdAl orders antiferromagnetically below the Neel temperature T{sub N} = 2.7 K. Heat capacity measurements reveal a Kondo temperature of T{sub K} {approx} 5 K. Magnetic order can be continuously suppressed by Ni doping on the Pd site or application of hydrostatic pressure and a quantum critical point is approached. Moreover, as inferred from neutron scattering, geometrical frustration is present in CePdAl. So far, no detailed microscopic measurements have been published on the crystalline electric field (CEF) excitations in CePdAl. Here, we report on our inelastic neutron scattering on CePdAl powder samples to study the characteristic energy scales. The measurements yield the CEF excitations and the quasielastic spin fluctuations. Two excited CEF levels have been detected at {approx} 240 K and > 400 K. The results are compared to the thermodynamic measurements.

Woitschach, S.; Stockert, O.; Steglich, F. [Max-Planck-Institut CPfS, Dresden (Germany); Koza, M. [Institut Laue-Langevin, Grenoble (France); Fritsch, V.; Loehneysen, H. v. [Karlsruher Institut fuer Technologie, Physikalisches Institut, Karlsruhe (Germany)

2012-07-01

257

Substitutional alloy of Ce and Al.  

Science.gov (United States)

The formation of substitutional alloys has been restricted to elements with similar atomic radii and electronegativity. Using high-pressure at 298 K, we synthesized a face-centered cubic disordered alloy of highly dissimilar elements (large Ce and small Al atoms) by compressing the Ce(3)Al intermetallic compound >15 GPa or the Ce(3)Al metallic glass >25 GPa. Synchrotron X-ray diffraction, Ce L(3)-edge absorption spectroscopy, and ab initio calculations revealed that the pressure-induced Kondo volume collapse and 4f electron delocalization of Ce reduced the differences between Ce and Al and brought them within the Hume-Rothery (HR) limit for substitutional alloying. The alloy remained after complete release of pressure, which was also accompanied by the transformation of Ce back to its ambient 4f electron localized state and reversal of the Kondo volume collapse, resulting in a non-HR alloy at ambient conditions. PMID:19188608

Zeng, Qiao-Shi; Ding, Yang; Mao, Wendy L; Luo, Wei; Blomqvist, Andreas; Ahuja, Rajeev; Yang, Wenge; Shu, Jinfu; Sinogeikin, Stas V; Meng, Yue; Brewe, Dale L; Jiang, Jian-Zhong; Mao, Ho-Kwang

2009-02-24

258

Genetic architecture of ALS in Sardinia.  

Science.gov (United States)

Conserved populations, such as Sardinians, displaying elevated rates of familial or sporadic amyotrophic lateral sclerosis (ALS) provide unique information on the genetics of the disease. Our aim was to describe the genetic profile of a consecutive series of ALS patients of Sardinian ancestry. All ALS patients of Sardinian ancestry, identified between 2008 and 2013 through the Italian ALS Genetic Consortium, were eligible to be included in the study. Patients and controls underwent the analysis of TARDBP, C9ORF72, SOD1, and FUS genes. Genetic mutations were identified in 155 out of 375 Sardinian ALS cases (41.3%), more commonly the p.A382T and p.G295S mutations of TARDBP and the GGGGCC hexanucleotide repeat expansion of C9ORF72. One patient had both p.G295S and p.A382T mutations of TARDBP and 8 carried both the heterozygous p.A382T mutation of TARDBP and a repeat expansion of C9ORF72. Patients carrying the p.A382T and the p.G295S mutations of TARDBP and the C9ORF72 repeat expansion shared distinct haplotypes across these loci. Patients with cooccurrence of C9ORF72 and TARDBP p.A382T missense mutation had a significantly lower age at onset and shorter survival. More than 40% of all cases on the island of Sardinia carry a mutation of an ALS-related gene, representing the highest percentage of ALS cases genetically explained outside of Scandinavia. Clinical phenotypes associated with different genetic mutations show some distinctive characteristics, but the heterogeneity between and among families carrying the same mutations implies that ALS manifestation is influenced by other genetic and nongenetic factors. PMID:25123918

Borghero, Giuseppe; Pugliatti, Maura; Marrosu, Francesco; Marrosu, Maria Giovanna; Murru, Maria Rita; Floris, Gianluca; Cannas, Antonino; Parish, Leslie D; Occhineri, Patrizia; Cau, Tea B; Loi, Daniela; Ticca, Anna; Traccis, Sebastiano; Manera, Umberto; Canosa, Antonio; Moglia, Cristina; Calvo, Andrea; Barberis, Marco; Brunetti, Maura; Pliner, Hannah A; Renton, Alan E; Nalls, Mike A; Traynor, Bryan J; Restagno, Gabriella; Chiò, Adriano

2014-12-01

259

The Al-B-Nb-Ti system  

International Nuclear Information System (INIS)

The thermodynamic description of the binary system Al-Ti is obtained by modelling the Gibbs energy of all individual phases using the CALPHAD approach. The model parameters have been evaluated by means of the computer optimization module PARROT, available within Thermo-Calc, taking into account recent experimental data and critically assessed information on phase equilibria and thermodynamic properties. The calculations are in close agreement with the experimental data on both phase equilibria and thermodynamics in the entire Al-Ti system

260

Structure of decagonal Al-Ni-Rh.  

Science.gov (United States)

The crystal structure of the decagonal phase in the system Al-Ni-Rh (d-Al-Ni-Rh) was analyzed in the five-dimensional embedding approach based on single-crystal synchrotron X-ray diffraction data. The structure can be described as a quasiperiodic packing of partially overlapping decagonal and pentagonal columnar clusters with ??21?Å diameter and ??4?Å period along the tenfold axis. PMID:25080252

Logvinovich, Dmitry; Simonov, Arkadiy; Steurer, Walter

2014-08-01

261

Magnetic Properties of Disordered Fe3Al  

Science.gov (United States)

The magnetic properties of Fe3Al powders prepared by filing the ingot in both as-filed and annealed form are studied. Results of Mössbauer, X-ray diffraction and DC magnetization studies show that the magnetic properties are modified due to formation of non-magnetic Fe3AlC0.5 phase due to C intercalated on filing. The hyperfine fields obtained are explained in terms of nearest and next nearest neighbor configurations of 57Fe.

Nehra, J.; Kabra, K.; Jani, S.; Ranjith, P. M.; Lakshmi, N.; Venugopalan, K.

2011-07-01

262

Magnetism of Al-Mn quasicrystals  

Energy Technology Data Exchange (ETDEWEB)

The effect of symmetry and concentration of Mn on the magnetism of Al-Mn quasicrystals has been investigated through self-consistent density-functional calculations using molecular clusters and supercell band-structure schemes. A single Mn atom surrounded by 54 Al atoms in an icosahedral or a cuboctahedral structure is found to be nonmagnetic. However, as the Mn concentration is increased, moments develop on Mn sites whose magnitude and coupling depend on their location.

Liu, F.; Khanna, S.N.; Magaud, L.; Jena, P. (Physics Department, Virginia Commonwealth University, Richmond, Virginia 23284-2000 (United States)); de Coulon, V.; Reuse, F. (Institut de Physique Experimentale, Ecole Polytechnique Federale de Lausanne, PHB-Ecublens, Lausanne (Switzerland)); Jaswal, S.S.; He, X. (Department of Physics and Astronomy, The University of Nebraska-Lincoln, 260 Behlen Laboratory, Lincoln, Nebraska 68588-0111 (United States)); Cyrot-Lackman, F. (Laboratoire d' Etudes des Proprietes Electroniques des Solides, Centre National de la Recherche Scientifique, Boite Postale 166X, 38042 Grenoble, CEDEX France ( ))

1993-07-01

263

Corrosion behavior of solid solution (Ti,Al)N as a function of Al concentration  

Energy Technology Data Exchange (ETDEWEB)

In this work, a series of (Ti, Al) N coatings with different Al contents were deposited on 304 stainless steel substrates by Hollow Cathode Discharge (HCD) method. The coatings were grown on 304 stainless steel substrates at 400 C. The coatings were characterized using energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), atomic force microscopy (AFM), and microhardness test. The XRD confirmed the transition from TiN phase to (Ti, Al) N phase and then to AlN phase with increasing Al concentration in the solid solution. It was found that with increasing Al concentration the hardness of the coatings initially increased up to a maximum value of about 30 GPa at around 32 at.% of Al and then the coating hardness decreased rapidly with further increase of Al content (Al > 32 at.%). The potentiodynamic polarization analysis was carried out in 3.5 wt.% NaCl solutions to study the corrosion resistance of the coatings. From the corrosion test it can be inferred that the amount of Al atoms in the coatings plays an important role for reducing the corrosion. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Larijani, M.M.; Seyedi, H. [Nuclear Science and Technology Research Institute, P. O. Box 31485-498, Karaj (Iran, Islamic Republic of); Manouchehrian, M. [Department of Physics, Science Faculty, South Tehran Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Yari, M. [Engineering Department Materials, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of)

2012-08-15

264

AuAl2 and PtAl2 as potential plasmonic materials  

International Nuclear Information System (INIS)

Highlights: •The electronic structure dielectric functions of PtAl2, AuAl2 and intermediate alloys were calculated. •The experimental reflectivity and EELS for PtAl2 showed good agreement with the theoretical spectra. •The yellow color of PtAl2 is associated with a bulk plasmon at 3 eV. •These materials are good candidates for applications in plasmonics. -- Abstract: The dielectric functions of PtAl2, AuAl2 and hypothetical intermediate alloys of the two in the form of AuxPt1?xAl2 were calculated from first principles using density functional theory (DFT) and the random phase approximation (RPA). From these, the reflectivity, electron energy-loss spectra (EELS) and small sphere extinction spectra are predicted. The experimental reflectivity and EELS were measured for PtAl2 and showed good agreement with the theoretical spectra. The yellow color of PtAl2 is associated with a bulk plasmon at 3 eV. We predict that the optical properties of hypothetical intermediate alloys would show a smooth evolution with composition. The details of this change can be understood by examination of the underlying density of states (DOS). The predicted small sphere extinction spectra and quality factors show a strong surface plasmon resonance for these materials, with PtAl2 having the optimum performance. The results indicate that these materials are good candidates for applications in plasmonics

265

Magnetism in Fe4Al13 and related FeAl intermetallics  

Science.gov (United States)

We report the results of an experimental study of FeAl alloys, including Fe4Al13, FeAl2 and Fe2Al5. By using NMR, dc magnetic susceptibility, and specific heat, we found that Fe4Al13 and Fe2Al5 are non-magnetic with some dilute magnetic moments, while FeAl2 can be characterized as a concentrated local moment system. Fe4Al13 is a decagonal quasicrystal approximant with 102 atoms in its unit cell. The ^27Al NMR spin-lattice relaxation indicates a very narrow pseudogap in the electronic density of states [g(E)] in the vicinity of the Fermi energy. The observations could be fit assuming a parabolic variation of g(E), consistent with observations in other quasicrystals and approximants. NMR lineshape measurements also agree with this analysis, and show that the system is dilute-magnetic, in strong contrast to the FeAl2 ordered intermetallic. We use specific heat to analyze the dilute moment density. This work was supported by the Robert A. Welch Foundation, Grant No. A-1526, by the National Science Foundation (DMR-0103455), and by Texas A&M University through the Telecommunications and Informatics Task Force.

Chi, Ji; Li, Yang; Gou, Weiping; Goruganti, V.; Rathnayaka, K. D. D.; Ross, Joseph H., Jr.

2006-03-01

266

Al/sub 3/Li precipitate modification in an Al-Li-Zr alloy  

International Nuclear Information System (INIS)

An Al-2.34Li-1.07Zr (weight percent) alloy was produced using rapid solidification processing in an attempt to modify the ?' (Al/sub 3/Li) precipitate found in the Al-Li binary system to a complex Al/sub 3/(Li,Zr) phase. Such a modification is expected to increase fracture toughness and ductility by decreasing shear localization, which is a major drawback in Al-Li alloys. A novel microstructure is presented in which a zirconium-rich phase present as fine spheres or discontinuously precipitated rods (with diameters of 6 to 20 nm) is subsequently enveloped by ?' during aging at 1900C. Electron diffraction effects, energy-dispersive X-ray analysis in scanning transmission electron microscopy, and preliminary electron energy loss spectroscopy results indicate that the precipitate phase stable at 5000C is Al/sub 3/(Li/sub x/,Zr/sub 1-x/), where x appears to be 0.45 to 0.8. This is in contrast to the Al-Li and AL-Zr binary systems, in which the equilibrium phases at 5000C for these solute levels are aluminum solid solution and Al/sub 3/Zr in an aluminum matrix, respectively. The alloy shows longitudinal strength-ductility combinations which are significantly better than those of a low-zirconium control alloy and which compare quite favorably with those of other Al-Li alloys

267

Thermodynamics and surface properties of liquid Al-Ga and Al-Ge alloys  

Energy Technology Data Exchange (ETDEWEB)

The surface properties of Al-Ga and Al-Ge liquid alloys have been theoretically investigated at a temperature of 1100 K and 1220 K respectively. For the Al-Ga system, the quasi chemical model for regular alloy and a model for phase segregating alloy systems were applied, while for the Al-Ge system the quasi chemical model for regular and compound forming binary alloys were applied. In the case of Al-Ga, the models for the regular alloys and that for the phase segregating alloys produced the same value of order energy and same values of thermodynamic and surface properties, while for the Al-Ge system, the model for the regular alloy reproduced better the thermodynamic properties of the alloy. The model for the compound forming systems showed a qualitative trend with the measured values of the thermodynamic properties of the Al-Ge alloy and suggests the presence of a weak complex of the form Al{sub 2}Ge{sub 3}. The surface concentrations for the alloys show that Ga manifests some level of surface segregation in Al-Ga liquid alloy while the surface concentration of Ge in Al-Ge liquid alloy showed a near Roultian behavior below 0.8 atomic fraction of Ge. (orig.)

Anusionwu, B.C. [Abdus Salam Int. Centre for Theoretical Physics, Trieste (Italy); Federal University of Technology, Department of Physics, Owerri (Nigeria); Adebayo, G.A. [Abdus Salam Int. Centre for Theoretical Physics, Trieste (Italy); University of Agriculture, Department of Physics, Abeokuta (Nigeria); Madu, C.A. [Federal University of Technology, Department of Physics, Owerri (Nigeria)

2009-11-15

268

Thermoluminescence properties of AlN ceramics  

DEFF Research Database (Denmark)

The paper describes thermoluminescence (TL) properties of AlN:Y2O3 ceramics irradiated with ionising radiation. A high TL sensitivity of AlN:Y2O3 ceramics to radiation encouraged a study of the AlN ceramics for application as a dosimetric material. The paper presents experimental data on: glow curve, emission spectrum, dose response, energy dependence, influence of heating rate and fading rate. The measured TL characteristics were compared with those of well-known, widely used TLDs, i.e. LiF:Mg,Ti, LiF:Mg,Cu,P and Al2O3:C. It is concluded that AlN:Y2O3 ceramics showing a radiation sensitivity which is approximately 50 times greater than that of LiF:Mg,Ti is an interesting dosimetry material; however due to a high fading rate of the TL of AlN:Y2O3 on storage at room temperature, a further development of the material for improving the fading characteristics is needed for its application for dosimetry purposes. (C) 1998 Elsevier Science Ltd. All rights reserved.

Trinkler, L.; Christensen, P.

1998-01-01

269

Modeling of precipitation in Al alloys  

Energy Technology Data Exchange (ETDEWEB)

Objective was the development of a computational model of precipitation from a supersaturated alloy solid solution. The model is based on the formalism of chemical-reaction-rate theory combined with classical descriptions of precipitate thermodynamic properties and a mean-field treatment of diffusion-limited growht and coarsening. For the case of precipitation of Al{sub 3}Sc in supersaturated Al-Sc alloys, it is demonstrated how the model can be used to calculate number densities and size distributions of precipitates as a function of aging time and temperature, including effects of continuous cooling and thermally generated point defects. Application of the model to a specific alloy system requires knowledge of diffusion data, point defect energetics, and thermodynamic properties for bulk phases and interphase interfaces. For interfaces and point defects, thermodynamic data can be difficult to measure and reliable values of defect free energies are often unavailable. For this reason, part of the efforts were devoted to applying semiempirical and first-principles atomistic techniques to the calculation of interfacial and point-defect thermodynamic properties. This report discusses applications for interphase interfaces in the Al-Ag, Al-Sc, and Al-Li alloy systems. We also describe atomistic work aimed at understanding the energetics of vacancy clusters in Al. These clusters serve as sinks for isolated vacancies during aging and their growth can lead to more complex defects, such as dislocation loops, that act as heterogeneous nucleation sites.

Asta, M.; Foiles, S.M.; Wolfer, W.G. [Sandia National Labs., Livermore, CA (United States)] [and others

1996-10-01

270

Phase relationships in the Al-rich region of the Al-Cu-Er system  

International Nuclear Information System (INIS)

Research highlights: ? One ternary phase ?1-Al8Cu4Er in Al-rich region with a composition of 59.4-60.4 at.% Al, 32.2-33.8 at.% Cu, and 6.4-7.7 at.% Er is observed in both as-cast and annealed alloys. At 673 K, the binary Al3Er phase dissolves about 3.51 at.% Cu. ? The calculated solidification paths (based on the CALPHAD method) of as-cast alloys are in agreement with the experimental results. ? It can be found that the resultant thermodynamic database can be applied to case studies of as-cast alloys, showing that the literature thermodynamic description of the Al-Cu-Er system is reliable as a working basis for computer-assisted alloy design. - Abstract: The Al-rich region of the ternary Al-Cu-Er system is investigated using the method of X-ray diffraction, scanning electron microscopy with energy dispersive X-ray spectroscopy. Phase equilibria in the Al-rich region of the Al-Cu-Er system at 673 K have been obtained, and the microstructures of as-cast alloys in the Al-rich region are also investigated. One ternary phase ?1-Al8Cu4Er with a composition of 59.4-60.4 at.% Al, 32.2-33.8 at.% Cu, and 6.4-7.7 at.% Er is observed in both as-cast and annealed alloys. At 673 K, the binary Al3Er phase dissolves about 3.51 at.% Cu. The calculated solidification paths (based on the CALPHAD method) of as-cast alloys are in agreement with the experimental results. results.

271

Degradasi Lapisan Aluminida pada Paduan Intermetalik ?2-Ti3Al / ?-TiAl Akibat Oksidasi Siklik  

Directory of Open Access Journals (Sweden)

Full Text Available Two-phase inter-metallic alloy ?2-Ti3Al/?-TiAl is developed to operated at high temperature in oxidative environment. However its oxidation rate can not be tolerated due to formation of TiO2 which is not protective. If the alloy is used in gas turbine that often have thermal cycle, it will cause cracking and flaking oxide crust. Coating is correct solution to improve properties of this alloy so that it can be used at high temperature. By enriching the material surface with significant amount of Al element there will be a formation of Al2O3 protective oxide. The method applied to get formation of Al2O3 is the pack cementation. This study discusses of characteristic coating and oxide crust formation at two-phase inter-metallic alloy of ?2-Ti3Al/?-TiAl from pack aluminizing process Abstract in Bahasa Indonesia; Paduan intermetalik dua fasa ?2-Ti3Al/?-TiAl dikembangkan untuk operasi temperature tinggi dalam lingkungan oksidatif. Namun laju oksidasinya tidak dapat ditolelir karena akan teroksidasi membentuk kerak oksida TiO2 yang tidak protektif. Pada Mesin turbin gas yang seringkali mengalami siklus thermal, dapat mengakibatkan peretakan (cracking dan pengelupasan (spalling kerak oksida. Coating merupakan solusi yang tepat agar paduan ini dapat digunakan pada temperature tinggi. Dengan memperkaya permukaan benda kerja dengan unsur Al sehingga material mampu membentuk kerak oksida protektif Al2O3 saat teroksidasi. Metoda pelapisan temperature tinggi yang sering diterapkan untuk keperluan ini adalah pack cementation. Studi ini membahas sebagian dari hasil pengujian oksidasi siklik. Khususnya pembahasan karakteristik coating dan kerak oksida yang terbentuk pada paduan intermetalik dua fasa ?2-Ti3Al/?-TiAl hasil pack aluminizing. Kata kunci: Coating, cyclic oxidation, pack aluminizing.

Toto Saputra

2008-01-01

272

Improving arc joining of Al to steel and Al to stainless steel  

International Nuclear Information System (INIS)

Highlights: ? Al alloy was joined to galvanized steel with assistance of ultrasonic vibration. ? Ultrasonic vibration during GTAW increased the joint strength by 27%. ? Al alloy was joined to stainless steel with Zn-15Al flux-cored filler wire. ? Postweld heat treatment doubled or even tripled the joint strength. ? Weld solidification microstructure was explained based on ternary phase diagrams. - Abstract: Gas-tungsten arc welding (GTAW) with controlled heat input could avoid the formation of massive brittle Al–Fe intermetallics during solidification in dissimilar-metal joining of aluminum to steel. In the first part of the present study an Al–Mg alloy was joined to galvanized steel by GTAW with an Al–Si filler metal. The weld solidification microstructure was explained based on the Al–Mg–Si phase diagram. Ultrasonic vibration during GTAW increased the joint strength by 27%. Grain refinement, decreased Fe–Al intermetallics, and increased microhardness in both the heat-affected zone and the weld were observed, thus explaining the improved joint strength. In the second part, an Al–Mg alloy was joined to 304 stainless steel using a Zn-15Al filler metal with a noncorrosive flux core. The weld solidification microstructure was explained based on the Al–Zn–Mg phase diagram. Postweld heat treatment (PWHT) at 280 °C for 30 min doubled or even tripled the joint strength depending on the Al-sheet thickness. Dissolution of coarse Zn-rich particles ah particles at the weld/steel interface was observed after PWHT, thus eliminating these weak particles from the interface. The formation of Zn-rich particles near the interface and their dissolution by PWHT were explained based on the Al–Fe–Zn phase diagram.

273

Improving arc joining of Al to steel and Al to stainless steel  

Energy Technology Data Exchange (ETDEWEB)

Highlights: Black-Right-Pointing-Pointer Al alloy was joined to galvanized steel with assistance of ultrasonic vibration. Black-Right-Pointing-Pointer Ultrasonic vibration during GTAW increased the joint strength by 27%. Black-Right-Pointing-Pointer Al alloy was joined to stainless steel with Zn-15Al flux-cored filler wire. Black-Right-Pointing-Pointer Postweld heat treatment doubled or even tripled the joint strength. Black-Right-Pointing-Pointer Weld solidification microstructure was explained based on ternary phase diagrams. - Abstract: Gas-tungsten arc welding (GTAW) with controlled heat input could avoid the formation of massive brittle Al-Fe intermetallics during solidification in dissimilar-metal joining of aluminum to steel. In the first part of the present study an Al-Mg alloy was joined to galvanized steel by GTAW with an Al-Si filler metal. The weld solidification microstructure was explained based on the Al-Mg-Si phase diagram. Ultrasonic vibration during GTAW increased the joint strength by 27%. Grain refinement, decreased Fe-Al intermetallics, and increased microhardness in both the heat-affected zone and the weld were observed, thus explaining the improved joint strength. In the second part, an Al-Mg alloy was joined to 304 stainless steel using a Zn-15Al filler metal with a noncorrosive flux core. The weld solidification microstructure was explained based on the Al-Zn-Mg phase diagram. Postweld heat treatment (PWHT) at 280 Degree-Sign C for 30 min doubled or even tripled the joint strength depending on the Al-sheet thickness. Dissolution of coarse Zn-rich particles at the weld/steel interface was observed after PWHT, thus eliminating these weak particles from the interface. The formation of Zn-rich particles near the interface and their dissolution by PWHT were explained based on the Al-Fe-Zn phase diagram.

Dong Honggang, E-mail: donghg@dlut.edu.cn [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116085 (China); Yang Liqun [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116085 (China); Dong Chuang [Key Lab of Materials Modification, Dalian University of Technology, Ministry of Education, Dalian 116085 (China); Kou Sindo [Department of Materials Science and Engineering, University of Wisconsin, 1509 University Ave, Madison, WI 53706 (United States)

2012-02-01

274

Natural and synthetic flavonoid derivatives with potential antioxidant and anticancer activities  

OpenAIRE

Die Familie der Flavonoide ist als Naturprodukte sehr gut bekannt und findet sich in einem Großteil der Pflanzenfamilie wieder. Mehr als 8000 verschiedene Flavonoide wurden zum jetzigen Zeitpunkt aus Quellen natürlichen Ursprungs isoliert. Die strukturellen Unterschiede dieser Flavonoide, sowie deren Wirkung gegen Krebs, Schutz vor Krebsentstehung, Antioxidantien-Aktivität, kardiovaskulärer und hepatischer Schutz sowie antibakterielle, antifungizide als auch antivirale Aktivität, spiegel...

Mohammed, Hamdoon

2009-01-01

275

Optical microcavities and enhanced electroluminescence from electroformed Al-Al2O3-Ag diodes  

International Nuclear Information System (INIS)

Electroluminescence (EL) and electron emission into vacuum (EM) occur when a non-destructive dielectric breakdown of Al-Al2O3-Ag diodes, electroforming, results in the development of a filamentary region in which current-voltage (I-V) characteristics exhibit voltage-controlled negative resistance. The temperature dependence of I-V curves, EM, and, particularly, EL of Al-Al2O3-Ag diodes with anodic Al2O3 thicknesses between 12?nm and 30?nm, has been studied. Two filters, a long-pass (LP) filter with transmission of photons with energies less than 3.0?eV and a short-pass (SP) filter with photon transmission between 3.0 and 4.0?eV, have been used to characterize EL. The voltage threshold for EL with the LP filter, VLP, is ?1.5?V. VLP is nearly independent of Al2O3 thickness and of temperature and is 0.3–0.6?V less than the threshold voltage for EL for the SP filter, VSP. EL intensity is primarily between 1.8 and 3.0?eV when the bias voltage, VS ? 7?V. EL in the thinnest diodes is enhanced compared to EL in thicker diodes. For increasing VS, for diodes with the smallest Al2O3 thicknesses, there is a maximum EL intensity, LMX, at a voltage, VLMX, followed by a decrease to a plateau. LMX and EL intensity at 4.0?V in the plateau region depend exponentially on Al2O3 thickness. The ratio of LMX at 295?K for a diode with 12?nm of Al2O3 to LMX for a diode with 25?nm of Al2O3 is ?140. The ratio of EL intensity with the LP filter to EL intensity with the SP filter, LP/SP, varies between ?3 and ?35; it depends on Al2O3 thickness and VS. Enhanced EL is attributed to the increase of the spontaneous emission rate of a dipole in a non-resonant optical microcavity. EL photons interact with the Ag and Al films to create surface plasmon polaritons (SPPs) at the metal-Al2O3 interfaces. SPPs generate large electromagnetic fields in the filamentary region of the electroformed Al-Al2O3-Ag diode, which then acts as an optical microcavity. A model is proposed for electronic processes in electroformed Al-Al2O3-Ag diodes

276

Optical microcavities and enhanced electroluminescence from electroformed Al-Al2O3-Ag diodes  

Science.gov (United States)

Electroluminescence (EL) and electron emission into vacuum (EM) occur when a non-destructive dielectric breakdown of Al-Al2O3-Ag diodes, electroforming, results in the development of a filamentary region in which current-voltage (I-V) characteristics exhibit voltage-controlled negative resistance. The temperature dependence of I-V curves, EM, and, particularly, EL of Al-Al2O3-Ag diodes with anodic Al2O3 thicknesses between 12 nm and 30 nm, has been studied. Two filters, a long-pass (LP) filter with transmission of photons with energies less than 3.0 eV and a short-pass (SP) filter with photon transmission between 3.0 and 4.0 eV, have been used to characterize EL. The voltage threshold for EL with the LP filter, VLP, is ˜1.5 V. VLP is nearly independent of Al2O3 thickness and of temperature and is 0.3-0.6 V less than the threshold voltage for EL for the SP filter, VSP. EL intensity is primarily between 1.8 and 3.0 eV when the bias voltage, VS ? 7 V. EL in the thinnest diodes is enhanced compared to EL in thicker diodes. For increasing VS, for diodes with the smallest Al2O3 thicknesses, there is a maximum EL intensity, LMX, at a voltage, VLMX, followed by a decrease to a plateau. LMX and EL intensity at 4.0 V in the plateau region depend exponentially on Al2O3 thickness. The ratio of LMX at 295 K for a diode with 12 nm of Al2O3 to LMX for a diode with 25 nm of Al2O3 is ˜140. The ratio of EL intensity with the LP filter to EL intensity with the SP filter, LP/SP, varies between ˜3 and ˜35; it depends on Al2O3 thickness and VS. Enhanced EL is attributed to the increase of the spontaneous emission rate of a dipole in a non-resonant optical microcavity. EL photons interact with the Ag and Al films to create surface plasmon polaritons (SPPs) at the metal-Al2O3 interfaces. SPPs generate large electromagnetic fields in the filamentary region of the electroformed Al-Al2O3-Ag diode, which then acts as an optical microcavity. A model is proposed for electronic processes in electroformed Al-Al2O3-Ag diodes.

Hickmott, T. W.

2013-12-01

277

Alpha and beta stabilizer character of Al in Zr-Nb-Al alloys  

International Nuclear Information System (INIS)

The T?/?+? of Zr5Nb and Zr5Nb2Al (weight %) were determined in order to observe the alpha-stabilizer character of Al in ternary Zr-Nb-Al alloys. Techniques employed were change of resistivity with temperature in dynamic experiences, and metallography of samples quenched to room temperature after isothermal annealings. The T?/?+? of the ternary resulted 17 ± 8 deg C higher than that of the binary alloy. In addition, taking into account the results of previous investigations of the transformation of beta on quenching Zr-Nb-Al alloys from the beta field to room temperature, it is concluded that the beta-stabilizer character of Nb is stronger than the alpha-stabilizer character of Al in these Zr alloys, and that the Al can have important influence on the mechanical properties by the appearance of TRIP effect. (Author)

278

Structure and mechanical properties of Al-12%Si alloy with fast cooling Al-12%Si  

Directory of Open Access Journals (Sweden)

Full Text Available A homogenous modifier obtained by the rapid solidification at a cooling rate equal to v=300 K/s was applied to the modification of the Al-12%Si alloy. The different modifiers were obtained by means of the Al-Si alloys. The components Al-12%Si were put into crucible containing the liquid Al-12%Si alloy and kept for one minute to obtain a new homogenous alloy which after break-up was homogenous modifier. Both, effect of cooling rate applied to obtain modifier and weight in weight modifier concentration in the melt on structure, tensile strength, elongations and hardness of Al-12%Si alloy are determined. A structural, physical and mechanical properties resulting from the Al-12%Si alloy treatment by modifiers are studied in details.

T. Lipi?ski

2008-08-01

279

Models for frozen-free-split phenomena in e- -irradiated Al and Al-Fe  

International Nuclear Information System (INIS)

Samples of pure Al and Al containing 400 atppm Fe have been irradiated with electrons at 4.2 K and annealed at subsequently higher temperatures. During the annealing program in pure Al, the growth and decay of two pairs of mechanical relaxation peaks was observed, and in Al-Fe of one pair. The members of each pair grow and decay in a parallel fashion. They are explained as being due to the stress induced occupation of two different sets of elastic energy levels via two different relaxation modes by the reorientation of the same defect. For the pairs in pure Al and for the pair observed in Al-Fe atomistic models are given based on computer simulation studies

280

Thermal Properties in the MgAl2O4-Al2O3 System  

Energy Technology Data Exchange (ETDEWEB)

Compositional effects on the thermal diffusivity in the MgAl2O4-Al2O3 system were studied. The lowest thermal diffusivity, 0.0258 +/-5% cm/s, was measured between 79.8 and 83.9 wt% Al2O3 quenched from various temperatures between 1500 and 1700C. All of the chemistries in this range extend past the solvus, but still form a singe super-saturated spinel solid solution, regardless of quenching tempeature. A super-saturated metastable solid solution region was observed at 1500, 1600, and 1700C extending to 83.9, 85.2, and 87.1 wt% Al2O3, respectively. Beyond 83.9% Al2O3 a significant increase in thermal diffusivity, 11.7%, was observed and its attributed to precipiation of Al2O3 through spinodal decomposition.

Wilkerson, Dr. Kelley R. [Missouri University of Science and Technology; Smith, Jeffrey D [ORNL; Hemrick, James Gordon [ORNL

2013-01-01

281

{sup 27}Al NMR studies of NpPd{sub 5}Al{sub 2}  

Energy Technology Data Exchange (ETDEWEB)

We present {sup 27}Al NMR studies for a single crystal of the Np-based superconductor NpPd{sub 5}Al{sub 2}(T{sub c}=4.9K). We have observed a five-line {sup 27}Al NMR spectrum with a center line and four satellite lines separated by first-order nuclear quadrupole splittings. The Knight shift clearly drops below T{sub c}. The temperature dependence of the {sup 27}Al nuclear spin-lattice relaxation rate shows no coherence peak below T{sub c}, indicating that NpPd{sub 5}Al{sub 2} is an unconventional superconductor with an anisotropic gap. The analysis of the present NMR data provides evidence for strong-coupling d-wave superconductivity in NpPd{sub 5}Al{sub 2}.

Chudo, H., E-mail: chudo.hiroyuki@jaea.go.j [Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Sakai, H.; Tokunaga, Y.; Kambe, S. [Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Aoki, D.; Homma, Y.; Shiokawa, Y. [Institute for Materials Research, Tohoku University, Oarai, Ibaraki 311-1313 (Japan); Haga, Y.; Ikeda, S.; Matsuda, T.D. [Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Onuki, Y. [Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Yasuoka, H. [Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan)

2009-10-15

282

27Al NMR studies of NpPd5Al2  

International Nuclear Information System (INIS)

We present 27Al NMR studies for a single crystal of the Np-based superconductor NpPd5Al2(Tc=4.9K). We have observed a five-line 27Al NMR spectrum with a center line and four satellite lines separated by first-order nuclear quadrupole splittings. The Knight shift clearly drops below Tc. The temperature dependence of the 27Al nuclear spin-lattice relaxation rate shows no coherence peak below Tc, indicating that NpPd5Al2 is an unconventional superconductor with an anisotropic gap. The analysis of the present NMR data provides evidence for strong-coupling d-wave superconductivity in NpPd5Al2.

283

27Al NMR studies of NpPd 5Al 2  

Science.gov (United States)

We present 27Al NMR studies for a single crystal of the Np-based superconductor NpPd 5Al 2(Tc=4.9 K). We have observed a five-line 27Al NMR spectrum with a center line and four satellite lines separated by first-order nuclear quadrupole splittings. The Knight shift clearly drops below Tc. The temperature dependence of the 27Al nuclear spin-lattice relaxation rate shows no coherence peak below Tc, indicating that NpPd 5Al 2 is an unconventional superconductor with an anisotropic gap. The analysis of the present NMR data provides evidence for strong-coupling d-wave superconductivity in NpPd 5Al 2.

Chudo, H.; Sakai, H.; Tokunaga, Y.; Kambe, S.; Aoki, D.; Homma, Y.; Shiokawa, Y.; Haga, Y.; Ikeda, S.; Matsuda, T. D.; ?nuki, Y.; Yasuoka, H.

2009-10-01

284

Protective Al2O3 scale formation on NbAl3-base alloys  

Science.gov (United States)

The oxidation of NbAl3 with additions of Cr and Y was studied to determine the mechanisms of the beneficial effects of these elements upon oxidation. Cr additions to the binary NbAl3 alloy of up to 6.8 at. percent reduced the scale growth rates and promoted alpha-Al2O3 formation over much longer times relative to binary NbAl3. A major effect of Cr is to form a layer of AlNbCr at the metal/scale interface, which is inherently more oxidation-resistant than the matrix alloy in the long term. Yttrium additions to a Cr-containing alloy improved the scale growth rate and adherence and changed the scale microstructure to mimic that of a typical protective Al2O3 scale.

Doychak, J.; Hebsur, M. G.

1991-01-01

285

Nanocrack-induced leakage current in AlInN/AlN/GaN  

International Nuclear Information System (INIS)

Here we report on the study of nano-crack formation in Al1?xInxN/AlN/GaN heterostructures, on its association with composition fluctuation and on its local electrical properties. It is shown here that indium segregation at nano-cracks and threading dislocations originating from the non-pseudomorphic AlN interlayer could be the cause of the high reverse-bias gate leakage current of Ni/Au Schottky contacts on Al1?xInxN/AlN/GaN heterostructures and significantly affects the contact rectifying behavior. Segregation of indium around crack tips in Al1?xInxN acting as conductive paths was assessed with conductive atomic force microscopy.

286

A first-principles investigation of the phase stability of Ti2AlC with Al vacancies  

International Nuclear Information System (INIS)

Ti2AlC was predicted to bear Al-vacancy down to a sub-stoichiometry of Ti2Al0.5C. The phase instability beyond a critical Al content was attributed to occupation of the Ti-Al anti-bonding orbital, which reduces the coupling strength between Ti2C slab and Al atomic plane. The migration energy barrier of Al self-diffusion along the (0 0 0 1) plane was low, 0.83 eV, resulting in rapid out-diffusion of Al during oxidation and decomposition of Ti2AlC at high temperatures

287

Stabilization of itinerant (band) magnetism in FeAl by Ga substitution for Al  

International Nuclear Information System (INIS)

Band structure calculations of FeGa1-xAlx have been performed, to further investigate the stability of ferromagnetism in FeAl. The Stoner parameter increases by about 20% at the FeGa end. This is also confirmed by our spin-polarized calculations. We conclude that Ga substitution for Al is likely to stabilize the elusive (or illusive) ferromagnetic state in FeAl. [copyright] 2001 American Institute of Physics

288

A note on Wang et al's attack on Zhang et al's multiparty quantum secret sharing  

International Nuclear Information System (INIS)

Recently, Wang et al (2008 Phys. Lett. A 373 65) proposed an attack on Zhang et al's (2007 Opt. Commun. 269 418) multiparty quantum secret sharing scheme, in which the first and the last agent are reported to be able to cooperatively eavesdrop on all the secret messages without being detected. In this paper, we show that in Wang et al's attack, on average no more than half the secret messages can be eavesdropped. (paper)

289

Some aspects of anelastic and microplastic creep of pure Al and two Al-alloys  

OpenAIRE

Anelastic creep of pure Al, commercial Al-Cu and a binary Al-Cu alloy has been measured at room temperature by means of a high resolution laser interferometer. The irreversible component of the deformation was also quantified from measurements of the anelastic creep recovery. The dependence of the deformation-time curves on thermal treatment and cold work is analyzed. The mechanisms responsible for the room temperature anelastic creep are discussed. Materials loaded below their elastic limit ...

Sgobba, S.; Ku?nzi, H. -u; Ilschner, B.

1993-01-01

290

Effect of the interface in laminated composites of Al-1100 and Al-2024  

International Nuclear Information System (INIS)

Laminated composites consisting of alternating layers of Al-1100 and Al-2024 were produced by hot rolling, with 45% Al-2024 volume fraction. These composites were subjected to cyclic thermal treatment (various numbers of cycles) and to isothermal treatment (various numbers of cycles) and to isothermal treatment (at peak temperature and for times equivalent to those of the thermal cycles. Microhardness, tensile and fatigue crack arrester modes) were studied in the initial state and after treatments. (E.G.)

291

Two-Phase (TiAl+TiCrAl) Coating Alloys for Titanium Aluminides  

Science.gov (United States)

A coating for protecting titanium aluminide alloys, including the TiAl gamma + Ti3Al (alpha(sub 2)) class, from oxidative attack and interstitial embrittlement at temperatures up to at least 1000 C. is disclosed. This protective coating consists essentially of titanium, aluminum. and chromium in the following approximate atomic ratio: Ti(41.5-34.5)Al(49-53)Cr(9.5-12.5)

Brady, Michael P. (Inventor); Smialek, James L. (Inventor); Brindley, William J. (Inventor)

1998-01-01

292

From Ti–Al- to Ti–Al–N-sputtered 2D materials  

OpenAIRE

Abstract This paper reviews thin films constituted by elements based on the Ti–Al–N system, bearing in mind the role of the condensed phases in the development of structural components and functional devices. In recent decades, the Ti–Al, Ti–N and Al–N nanocrystalline binary systems have rapidly attracted research and industry interest. These systems have revealed a great performance via atomic-level structural control, making it possible to tailor new atomic structures and morphol...

Vieira, Maria; Ramos, Ana; Castanho, Jose?; Oliveira, Joa?o; Cavaleiro, Albano

2007-01-01

293

Lowest ionization potentials of Al2  

Science.gov (United States)

Potential curves for the lowest two electronic states, X 2Sigma(+)g and A 2Pi(u), of Al2(+) were computed using complete active space SCF/multireference CI wave functions and large Gaussian basis sets. The lowest observable vertical ionization potential, to Al2(+) X 2Sigma(+)g, of the Al2 X 3 Pi(u) ground state is calculated to occur around 6.1 eV, in excellent agreement with the experimental range of 6.0 to 6.42 eV obtained in recent cluster ionization studies by Cox and co-workers. The second vertical ionization potential, to Al2(+) A 2Pi(u), occurs near 6.4 eV, also within the experimental range. The adiabatic IP of 5.90 eV is in good agreement with the value of 5.8 to 6.1 eV deduced by Hanley and co-workers from the difference in thresholds between collision induced dissociation processes of Al3(+). The computed IP values are somewhat larger than those deduced from branching ratios in cluster fragmentation experiments by Jarrold and co-workers. The observation of an ionization threshold below 6.42 eV is shown to be incompatible with an Al2 ground electronic state assignment of 3Sigma(-)g, but the separation between the two lowest states of Al2 is so small that it is likely that both are populated in the experiments, so that this does not provide unambiguous support for the recent theoretical assignment of the ground state as 3Pi(u).

Bauschlicher, Charles W., Jr.; Barnes, Leslie A.; Taylor, Peter R.

1989-01-01

294

The lowest ionization potentials of Al2  

Science.gov (United States)

Potential curves for the lowest two electronic states (X 2 sigma g + and A 2 pi u) of Al2(+) were computed using complete active space SCF/multireference CI wave functions and large Gaussian basis sets. The lowest observable vertical ionization potential (to Al2(+) X 2 sigma g +) of the Al2 X 3 pi u ground state is calculated to occur around 6.1 eV, in excellent agreement with the experimental range of 6.0 to 6.42 eV obtained in recent cluster ionization studies by Cox and co-workers. The second vertical ionization potential (to Al2(+) A 2 pi u) occurs near 6.4 eV, also within the experimental range. The adiabatic IP of 5.90 eV is in good agreement with the value of 5.8 to 6.1 eV deduced by Hanley and co-workers from the difference in thresholds between collision induced dissociation processes of Al3(+). The computed IP values are somewhat larger than those deduced from branching ratios in cluster fragmentation experiments by Jarrold and co-workers. The observation of an ionization threshold below 6.42 eV is shown to be incompatible with an Al2 ground electronic state assignment of 3 sigma g -, but the separation between the two lowest states of Al2 is so small that it is likely that both are populated in the experiments, so that this does not provide unambiguous support for the recent theoretical assignment of the ground state as 3 pi u.

Bauschlicher, Charles W., Jr.; Barnes, Leslie A.; Taylor, Peter R.

1988-01-01

295

Wallada Bint al Mustakfi entre dos culturas  

Directory of Open Access Journals (Sweden)

Full Text Available La princesa cordobesa Wallada Bint al Mustakfi bil-lah, hija del califa al Mustakfi Muhammad Ibn Abdel Rahman Ibn Obaidil-lah Ibn Al Nasir lidin Al-lah era una poetisa estimable, a quien los grandes poetas no podían superar. Era una mujer única, guapa y decente. Mantenía una relación sentimental con el  poeta y visir Ibn Zaydún. Dicha pasión, narrada por los poemas escritos por ambos amantes, se terminó por la separación debida a los celos, también de ambos;  al poeta le gustó la voz de una esclava de la princesa. Eso dio rabia a la última. Movido también por los celos, Ibn Zaydún dedicó una epístola satírica al visir Ibn Abdús, que estaba enamorado de Wallada. Tal hecho también irritó a la princesa. A pesar de tener amantes y admiradores, Wallada murió sin casarse al  día 2 de safar de 480 (o 484 de la Híjira pasando los ochenta años Me han llamado la atención el carácter tan culto, independiente y liberal de aquella mujer, su relación amorosa con Ibn Zaydún que no acabó felizmente y los muchos años que vivió sin casasre. Parece que la vida de la princesa hispano-musulmana llamó también la atención de muchos escritores árabes y españoles. Prueba de ello son varias obras literarias escritas en árabe y en español sobre Wallada e Ibn Zaydún. Por consiguiente, me resulta muy interesante realizar un estudio comparativo sobre este tema averiguando si, o no, la diferencia de culturas influiría en las opiniones  de los autores sobre la vida sentimental de aquella poetisa cordobesa.

shreen Mahmoud Al Refai

2013-10-01

296

Short-period superlattices of AlN/Al0.08Ga0.92N grown on AlN substrates  

International Nuclear Information System (INIS)

High-quality short-period superlattices of AlN/Al0.08Ga0.92N have been grown by gas-source molecular-beam epitaxy with ammonia on Al face of AlN (0001) substrates. A significant reduction was achieved in the dislocation density, down to 3x108 cm-2. Complete removal of residual Al2O3 surface oxide is needed in order to obtain low dislocation density in homoepitaxy on AlN. We show that the presence of Al2O3 islands with the surface coverage as low as 0.2% results in increased dislocation density

297

Ternary invariant point at 374°C in the three phase region AlSb-Al-Zn inside the Al-Sb-Zn ternary system  

Directory of Open Access Journals (Sweden)

Full Text Available Al-Sb-Zn ternary system was investigated in the three phase region Al-AlSb-Zn, using differential thermal analysis (DTA, differential scanning calorimetry (DSC and scanning electron microscope equipped with energy dispersive spectrometer (SEM-EDS. The position and temperature of the invariant eutectic L ? AlSb + ?-Al + ? - Zn point inside Al-AlSb-Zn region was experimentally determined. To confirm the obtained results X-ray powder diffraction analysis or XRD was also done. All results were compared to the calculated isopleth phase diagrams using Thermo-Calc software (TCW 5. All calculations were done using the SSOL4 data base.

Klan?nik G.

2011-01-01

298

Micro Arc Oxidation of Wire Arc Sprayed Al-Mg6, Al-Si12, Al Coatings on Low Alloyed Steel  

OpenAIRE

Micro arc oxidation of wire arc sprayed Al-Mg6, Al-Si12 and Pure Al coatings on low carbon steel has been performed. The coatings have been analyzed using optic microscope, scanning electron microscopy, X-ray diffraction and surface roughness tester. At the same time, voltage and current regimes are investigated during the process. Then after MAO process, uniform Al2O3 ceramic coatings have been deposited on surface of Al-Mg6, Al-Si12 and Al coate...

Levent Cenk Kumruoglu; Fatih Ustel; Ahmet Ozel; Abdullah Mimaroglu

2011-01-01

299

77 FR 40492 - Revocation of Class D Airspace; Andalusia, AL; and Amendment of Class E Airspace; Fort Rucker, AL  

Science.gov (United States)

...also updates the geographic coordinates of the above airport; Cairns AAF, Ft. Rucker, AL; and Florala Municipal, AL, to be...ASO AL E5 Fort Rucker, AL [Amended] Fort Rucker, Cairns AAF, AL (Lat. 31[deg]16'33'' N., long....

2012-07-10

300

Solid state synthesis of Al-based amorphous and nanocrystalline Al-Nb-Si and Al-Zr-Si alloys  

Energy Technology Data Exchange (ETDEWEB)

This study concerns the development of high-specific-strength Al-based amorphous and/or nanocrystalline alloys by mechanical alloying of Al{sub 40}Tm{sub 40}Si{sub 20} and Al{sub 30}TM{sub 40}Si{sub 30} (TM=transition metal, Nb and Zr) elemental powder blends by high-energy ball milling. Microstructure of the milled product in different stages of milling has been characterized by X-ray diffraction, high-resolution transmission electron microscopy and energy-dispersive X-ray spectroscopy. Both the systems are amenable to partial solid state amorphisation and development of a composite microstructure comprising varying amounts of nanocrystalline face-centred cubic Nb- or Zr-based solid solution and amorphous phase by appropriate hours of milling. The body-centred to face-centred cubic polymorphic change in Nb or Zr seems closely related to grain refinement and plastic strain. (orig.)

Manna, I. [Metallurgical and Materials Engineering Dept., I. I. T., Kharagpur (India); Chattopadhyay, P.P. [Dept. of Metallurgy, B. E. Coll. (D. U.), Howrah (India); Banhart, F. [Dept. of Electron Microscopy, Univ. of Ulm, Ulm (Germany); Fecht, H.-J. [Materials Div., Univ. of Ulm, Ulm (Germany); Inst. for Nanotechnology, Research Center, Karlsruhe (Germany)

2003-07-01

301

Structure and mechanical properties of Al-12%Si alloy with fast cooling Al-12%Si  

OpenAIRE

A homogenous modifier obtained by the rapid solidification at a cooling rate equal to v=300 K/s was applied to the modification of the Al-12%Si alloy. The different modifiers were obtained by means of the Al-Si alloys. The components Al-12%Si were put into crucible containing the liquid Al-12%Si alloy and kept for one minute to obtain a new homogenous alloy which after break-up was homogenous modifier. Both, effect of cooling rate applied to obtain modifier and weight in weight modifier conce...

Lipin?ski, T.

2008-01-01

302

Effect of Crystalline State of Anodized Porous Al2O3/Al as Supports by Hydration  

Directory of Open Access Journals (Sweden)

Full Text Available The porous alumina as a plate catalytic support was prepared by anodization. Effects of hydration condition on the property of alumina supports were studied. The samples were characterized by XRD, SEM, BET and etc. to illustrate the Al2O3/Al forming mechanism. The results show that the best hydration temperature is 80¡?at which the amorphous alumina can be transformed into AlOOH, and become ?-Al2O3 after 500¡?alcination. Meanwhile, the monoliths catalytic carriers have a superior stability for crystalline structures in the steam atmosphere at high temperature.

ZHANG Qi, JIANG Zhong-Rui, SUN Dong-Mei, HAN Da-Ying, ZHU Zi-Bin

2012-07-01

303

Thermodynamic properties of alloys of the Al-Co and Al-Co-Sc systems  

Science.gov (United States)

Enthalpies of mixing for melts of the binary Al-Co system at 1870 K in the range 0 phase diagram of the Al-Co system, the thermodynamic properties of liquid and solid alloys of the Al-Co system over a wide range of temperatures and compositions are calculated using a software package of our own design, based on the model of ideal associated solutions (IAS). The enthalpies of mixing and the liquidus surface of the phase diagram of the ternary Al-Co-Sc system over the interval of concentrations are estimated by modeling with data on binary boundary subsystems. All of the components of both the binary Al-Co and ternary Al-Co-Sc systems tend to interact with one another quite strongly: ? H min(Al-Co) = -32.5 kJ/mol at x Co = 0.44; ? H min(Al-Co-Sc) = -46 kJ/mol for Al0.4Co0.3Sc0.3 (estimated).

Shevchenko, M. A.; Berezutskii, V. V.; Ivanov, M. I.; Kudin, V. G.; Sudavtsova, V. S.

2014-05-01

304

Strain Rates and Grain Growth in Al 5754 and Al 6061 Friction Stir Spot Welds  

Science.gov (United States)

The stir zone temperature and microstructures are compared in friction stir spot welds produced in Al 5754 and Al 6061 alloys. Electron backscattered diffraction was used to determine the relationship between tool rotation speed during welding and final stir zone grain size. Comparison of the grain sizes in rapidly quenched welds with those in air-cooled joints confirmed that grain growth occurred only in Al 6061 spot welds. There was no evidence of abnormal grain growth in the stir zones of Al 6061 welds; the final grain size could be represented using an Arrhenius equation. The strain rates during welding were determined by incorporating the stir zone temperature and average subgrain sizes in quenched spot welds in the Zener-Hollomon relation. When the tool rotation speed increased from 750 to 3000 RPM, the strain rate values ranged from 180 to 497 s-1 in Al 5754 spot welds and from 55 to 395 s-1 in Al 6061 spot welds. It is suggested that a no-slip boundary condition may be appropriate during numerical modeling of Al 5754 and 6061 friction stir spot welding. This is not the case during Al 7075, Al 2024, and Mg-alloy AZ91 spot welding because spontaneous melting facilitates slippage at the tool contact interface.

Gerlich, A.; Yamamoto, M.; North, T. H.

2007-06-01

305

Al-matrix composite materials reinforced by Al-Cu-Fe particles  

Energy Technology Data Exchange (ETDEWEB)

Al-matrix material composites were produced using hot isostatic pressing technique, starting with pure Al and icosahedral (i) Al-Cu-Fe powders. Depending on the processing temperature, the final reinforcement particles are either still of the initial i-phase or transformed into the tetragonal {omega}-Al0{sub 0.70}Cu{sub 0.20}Fe{sub 0.10} crystalline phase. Compression tests performed in the temperature range 293K - 823K on the two types of composite, i.e. Al/i and Al/{omega}, indicate that the flow stress of both composites is strongly temperature dependent and exhibit distinct regimes with increasing temperature. Differences exist between the two composites, in particular in yield stress values. In the low temperature regime (T {<=} 570K), the yield stress of the Al/{omega} composite is nearly 75% higher than that of the Al/i composite, while for T > 570K both composites exhibit similar yield stress values. The results are interpreted in terms of load transfer contribution between the matrix and the reinforcement particles and elementary dislocation mechanisms in the Al matrix.

Bonneville, J; Laplanche, G; Joulain, A; Gauthier-Brunet, V; Dubois, S, E-mail: joel.bonneville@univ-poitiers.f [Universite de Poitiers, PHYMAT, CNRS-UMR 6630, SP2MI, F-86962 Chasseneuil (France)

2010-07-01

306

Al-matrix composite materials reinforced by Al-Cu-Fe particles  

International Nuclear Information System (INIS)

Al-matrix material composites were produced using hot isostatic pressing technique, starting with pure Al and icosahedral (i) Al-Cu-Fe powders. Depending on the processing temperature, the final reinforcement particles are either still of the initial i-phase or transformed into the tetragonal ?-Al00.70Cu0.20Fe0.10 crystalline phase. Compression tests performed in the temperature range 293K - 823K on the two types of composite, i.e. Al/i and Al/?, indicate that the flow stress of both composites is strongly temperature dependent and exhibit distinct regimes with increasing temperature. Differences exist between the two composites, in particular in yield stress values. In the low temperature regime (T ? 570K), the yield stress of the Al/? composite is nearly 75% higher than that of the Al/i composite, while for T > 570K both composites exhibit similar yield stress values. The results are interpreted in terms of load transfer contribution between the matrix and the reinforcement particles and elementary dislocation mechanisms in the Al matrix.

307

CASTABILITY OF Al-Li-Mg AND Al-Li-Cu-Mg ALLOYS  

OpenAIRE

The objective of the present work is to study the casting characteristics of various Al-Li alloys, which include fluidity and strengths of the alloys and their interaction with cast molds. Materials investigated are Al-Li-Mg and Al-Li-Cu-Mg alloys with Li content of 2.5 wt%. The results show that sand molds with resin binders are good for Al-Li casting. Ceramic coatings can further reduce the metal-mold interactions. However, the permeability is also reduced by coating. The fluidity of Li-bea...

Tong, C.; Yao, L.; Nieh, C.; Chang, C.; Hsu, S.

1987-01-01

308

(Al,Ga)N overgrowth over AlN ridges oriented in [1120] and [1100] direction  

Energy Technology Data Exchange (ETDEWEB)

Epitaxial lateral overgrowth of 1.5 {mu}m wide AlN ridges with 1.5 {mu}m spacing with AlGaN or AlN was investigated by electron microscopy and cathodoluminescence. Overgrowth of [1100] oriented stripes leads to relatively smooth c-plane AlGaN surfaces while on [1120] oriented stripes strongly facetted surfaces evolve. The growth on the different facets leads to strong compositional fluctuations. These fluctuations can be prevented by the growth of binary AlN over the ridges instead of AlGaN. Only the [1100] oriented ridges formed smooth surfaces, suitable for subsequent deposition of AlGaN with homogeneous composition. The lateral epitaxial overgrowth leads to a remarkable reduction in threading dislocation density as shown by TEM and X-ray diffraction. The critical thickness of AlN before cracking was significantly increased in comparison to unpatterned growth. The resulting AlN template is a promising ultraviolet transparent template for LED. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Kueller, V.; Knauer, A.; Zeimer, U.; Rodriguez, H.; Weyers, M. [Ferdinand-Braun-Institut, Leibniz-Institut fuer Hoechstfrequenztechnik, Gustav-Kirchhoff-Str. 4, 12489 Berlin (Germany); Mogilatenko, A. [Institut fuer Physik, Humboldt-Universitaet-Berlin, Newtonstr. 15, 12489 Berlin (Germany); Kneissl, M. [Ferdinand-Braun-Institut, Leibniz-Institut fuer Hoechstfrequenztechnik, Gustav-Kirchhoff-Str. 4, 12489 Berlin (Germany); Institut fuer Festkoerperphysik, Technische Universitaet Berlin, Hardenbergstr. 36, 10623 Berlin (Germany)

2011-07-15

309

Moessbauer study of phase transformation in an Al-rich AlFe alloy  

International Nuclear Information System (INIS)

The type of intermetallic compounds formed in low alloyed Al-Fe material depends strongly upon the cooling rate during solidification. The equilibrium phase, Al3Fe is reported to form at cooling rates below 1 K/s. This phase is replaced by different metastable compounds in case of rapid solidification-Al6Fe: 1-10 K/s ; 3-11 K/s; AlxFe: 0.5-6 K/s; AlmFe and Al9Fe2: 10 K/s. The cooling rate in DC casting processes usually exceeds 1 K/s, thus the Al-Fe compounds formed in commercial pure aluminium and aluminium alloys, which generally contain a certain amount of iron, are mainly metastable. During homogenization of casting these phases may transform into stable Al3Fe modifying the workability and chemical properties of the material. This is the reason why the investigation of phase transformation in Al-Fe system is of such great importance. This paper describes experiments for studying kinetics of the Al6Fe -> Al3Fe transformation. 8 refs., 8 figs., 1 tab

310

27Al-NMR study of RPd2Al3 (R = Ce, Pr, Nd) system  

International Nuclear Information System (INIS)

Magnetic properties of RPd2Al2Al3 (R=Ce,Pr,Nd) system have been investigated by 27Al-NMR. An anisotropic hyperfine field Aani in the basal plane is negative for R = Pr and Nd, while Aani is positive for R = Ce, suggesting that f-p transferred hyperfine field contributes to the anisotropic Knight shift. From T1 = constant relation, the exchange interaction for R = Pr is estimated to be 560 K and is much larger than that for R = Ce and Nd. It was found in PrPd2Al3 that NMR intensity and (T1T)-1 decrease strongly near 30 K. (orig.)

311

Achieving conductive high Al-content AlGaN alloys for deep UV photonics  

Science.gov (United States)

Recent progresses in epitaxial growth and fundamental studies on electrical and optical properties of high Al-content AlGaN alloys with Si, Mg, and Zn doping are presented. For Si doped Al xGa1- xN, the Si activation energy was determined for x = 0 up to 1, and the resistivity of n-Al xGa1- xN was found to increases by one order of magnitude when Al content is increased by ~ 8%. From photoluminescence (PL) studies, three groups of deep impurity transitions were observed, related with deep level acceptors involving cation vacancy and its complexes: (VIII) 3-, (VIII-complex)2, and (VIII-complex) 1-, which are electron traps and compensating centers. By optimizing the growth processes to reduce the densities of cation vacancy and its complexes, the n-type conductivity of Al xGa1- xN was significantly improved. A record low room temperature n-type resistivity of 0.0075 ?•cm has been obtained for Al 0.7Ga 0.3N, and n-type conduction in pure AlN has also been achieved. We also review the electrical and optical measurement results of Mgdoped AlGaN and AlN. It was found that the overall material quality and conductivity of Mg-doped AlN are strongly correlated with the PL emission intensity of the nitrogen vacancy (V N 3+) related transition. Improved conductivity was obtained by suppressing the V N 3+ related emission line, which was attributed to the reduced hole compensation by V N 3+. With the identification of the emission peaks associated with V N 3+ hole compensating centers, the p-type conductivity of high Al-content AlGaN alloys was improved by monitoring and suppressing the intensity of the V N 3+ related emission lines. P-type conduction in Al xGa1- xN (x > 0.7) was confirmed at elevated temperatures (> 700 K). The possibility of using Zn as an alternative p-type dopant was also studied. It was found that contrary to the calculation, the energy level of Zn acceptor in AlN was about 0.74 eV, which is 0.23 eV deeper than Mg level in AlN.

Fan, Z. Y.; Lin, J. Y.; Jiang, H. X.

2007-02-01

312

Study on Mg/Al Weld Seam Based on Zn–Mg–Al Ternary Alloy  

Directory of Open Access Journals (Sweden)

Full Text Available Based on the idea of alloying welding seams, a series of Zn–xAl filler metals was calculated and designed for joining Mg/Al dissimilar metals by gas tungsten arc (GTA welding. An infrared thermography system was used to measure the temperature of the welding pool during the welding process to investigate the solidification process. It was found that the mechanical properties of the welded joints were improved with the increasing of the Al content in the Zn–xAl filler metals, and when Zn–30Al was used as the filler metal, the ultimate tensile strength could reach a maximum of 120 MPa. The reason for the average tensile strength of the joint increasing was that the weak zone of the joint using Zn–30Al filler metal was generated primarily by ?-Al instead of MgZn2. When Zn–40Al was used as the filler metal, a new transition zone, about 20 ?m-wide, appeared in the edge of the fusion zone near the Mg base metal. Due to the transition zones consisting of MgZn2- and Al-based solid solution, the mechanical property of the joints was deteriorated.

Liming Liu

2014-02-01

313

The PtAl? and PtAl2? anions: Theoretical and photoelectron spectroscopic characterization  

International Nuclear Information System (INIS)

We report a joint photoelectron spectroscopic and theoretical study of the PtAl? and PtAl2? anions. The ground state structures and electronic configurations of these species were identified to be C?v, 1?+ for PtAl?, and C2v, 2B1 for PtAl2?. Structured anion photoelectron spectra of these clusters were recorded and interpreted using ab initio calculations. Good agreement between theory and experiment was found. All experimental features were successfully assigned to one-electron transitions from the ground state of the anions to the ground or excited states of the corresponding neutral species

314

Magnetic structure of Fe-Si-Al films implanted with Al and N ions  

International Nuclear Information System (INIS)

Changes in the magnetic structure of Fe-Si-Al films due to Al and N ion implantation were studied by 57Fe Conversion Electron Moessbauer Spectrometry (CEMS). The peaks of the magnetic sextets due to the crystalline films became broader by implantation with 5*1016 Al/cm2, suggesting the formation of amorphous phases. In the CEM spectrum of one sample with large grains implanted with 1*1017 Al/cm2 a crystalline ?-Fe phase appeared. N implantation with the same dose did not amorphize the sample but the components with high magnetic hyperfine fields were enhanced. (author) 18 refs.; 5 figs.; 3 tabs

315

Bush lubas al-Zarqawi järglase kinni püüda / Aadu Hiietamm  

Index Scriptorium Estoniae

USA president George W. Bush teatas, et tapetud terrorivõrgustiku al Qaeda Iraagi haru liidri Abu Musab al-Zarqawi järglaseks nimetatud Abu Hamsa al-Muhajir on kuulutatud enim tagaotsitavaks terroristiks

Hiietamm, Aadu, 1954-

2006-01-01

316

Growth behaviors of intermetallic compound layers in Cu/Al joints brazed with Zn–22Al and Zn–22Al–0.05Ce filler metals  

International Nuclear Information System (INIS)

Highlights: • The evolution of interfacial compounds in Cu/Al brazed joints was released. • Adding Ce reduce the growth rate of IMCs as well as the ripening flux of CuAl2. • Adding Ce increased the diffusion activation energy of CuAl2. - Abstract: The structure development and growth rate of intermetallic compounds in Cu/Al brazed joint formed under aging treatment were investigated in this paper. Trace amount of rare earth Ce (0.05 wt.%) was added into Zn–22Al filler metal in order to reform the properties of the Cu/Al joint. The interfacial morphology and constituent phases at the interface were examined by the scanning electron microscopes (SEM) and X-ray energy dispersion spectrometry (EDS), respectively. The growth kinetics of intermetallic compounds formed in both systems (Zn–22Al and Zn–22Al–0.05Ce) was also investigated under different aging conditions. The results indicated that interface structure of Cu/Al brazed joints changed from CuAl2/CuZn3 to CuAl2/CuAl/CuZn3 and finally to ?/CuAl2/CuAl/CuZn3 during aging. The growth rate of intermetallic compounds observed in the Zn–22Al system was higher than that in Zn–22Al–0.05Ce. Meanwhile, the activation energy of CuAl2 phase increased from 76.9 kJ/mol to 87.6 kJ/mol with the 0.05 wt.% Ce addition. The results also revealed that the joint brazed with Zn–22Al–0.05Ce constantly possessed higher shear strength than that of Zn–22Al throughout the aging treatment. The addition of Ce into the Zn–22Al filler metal decreased the thickness of the intermetallic compound layer produced in the aging, resulting in higher fracture toughness

317

Angular distribution of interstellar 26Al  

International Nuclear Information System (INIS)

Although the detection by HEAO 3 of 26Al in the interstellar medium has profound consequences for nucleosynthesis, the origins of the 26Al cannot be determined without information on its angular distribution. Both as an aid to further HEAO 3 and Solar Maximum Mission data analysis and also for observational planning for Gamma-Ray Observatory, we present angular distributions and local concentrations of 26Al for five different assumptions about its distribution in the galactic disk: it is proportional to sigma/sub CO/ (case A); it is proportional to sigma/sub CO/ times a galactic metallicity gradient (case B); it is proportional to average disk brightness B(R) (case C); it is proportional to total gas sigma/sub CO/ +sigma/sub HI/ (case D); it is proportional to nova rate (case E). Physical justifications of these assumptions are given. Only the nova distribution, strongly peaked toward the galactic center, will be easily distinguishable from the others, although they also have significant differences that will be discernible with adequate counting statistics. We find for these distributions that the present average isotopic ratio at the solar galactocentric radius is 26Al/27Al = 5 x 10-6 to within a factor of 2: too large for steady state supernova nucleosynthesis but too small to provide an explanation of 26Mg excess in Allende inclusions

318

Survey and alignment at the ALS  

International Nuclear Information System (INIS)

This paper describes survey and alignment at the Lawrence Berkeley National Laboratory's Advanced Light Source (ALS) accelerators from 1993 to 1995. The ALS is a 1.0 - 1.9 GeV electron accelerator producing extremely bright synchrotron light in the UV and soft-X-ray wavelengths. At the ALS, electrons are accelerated in a LINAC to 50 MeV, injected into a booster ring for further acceleration and finally injected into the storage ring. This is shown schematically in Figure 1. The storage ring, some 200 m in circumference, has been run with electron currents above 400 mA with lifetimes as high as 24 hours. The ALS is a third generation light source and requires for efficient storage ring operation, magnets aligned to within 150 mm of their ideal position. To accomplish this a network of monuments was established and their positions measured with respect to one another. The data was reduced using GEONET'' and STAR*NET'' software. Using the monuments as reference points, magnet positions were measured and alignment confirmed using the Kem Electronic Coordinate Determination System (ECDS''). A number of other papers dealing with survey and alignment (S ampersand A) at the ALS have been written that may further elucidate some details of the methods and systems described in this paper

319

Photoemission from Al Alloys during Tensile Deformation  

Science.gov (United States)

We report simultaneous measurements of strain and photoelectron emission intensity from high purity Al (1350), Al-Mg (5052), Al-Mn (3003), Al-Cu (2024) and Al-Mg-Si (6061) alloys under uniaxial tension due to pulsed excimer laser radiation (248-nm). The photoemission signals are sensitive to deformation-induced changes in surface morphology, including the formation of slip lines and slip bands. In the early stages of deformation (strain Â¡Ü 0.03), the photoemission intensity increases gradually in a nonlinear fashion. Depending on sample composition and heat treatment, the photoemission intensity subsequently grows linearly until the accumulated strain reaches about 0.20. Finally, the photoemission intensity increases parabolically until failure. The onset of strain localization corresponds to the transition from linear to parabolic growth. A constitutional model incorporating microstructure evolution and work-hardening during tensile deformation is proposed to qualitatively interpret the growth of the photoemission signals as a function of strain. The photoemission signals from the tested alloys are interpreted in terms of the effect of surface treatment, work function, microstructure, and composition on the development of dislocation structures during deformation.

Cai, Mingdong; Langford, Stephen; Levine, Lyle; Dickinson, Thomas

2004-03-01

320

Cd ion implantation in AlN  

International Nuclear Information System (INIS)

Highlights: ? Cd ion implanted in AlN thin films. ? XRD shows damage produced during implantation. ? Annealing recovers damage in low fluence sample. ? RBS/C measurements show that Cd occupies substitutional sites. ? Cd can be a good candidate for p-type doping. - Abstract: AlN thin films were implanted with cadmium, to fluences of 1 × 1013 and 8 × 1014 at/cm2. The implanted samples were annealed at 950 °C under flowing nitrogen. Although implantation damage in AlN is known to be extremely stable the crystal could be fully recovered at low fluences. At high fluences the implantation damage was only partially removed. Implantation defects cause an expansion of the c-lattice parameter. For the high fluence sample the lattice site location of the ions was studied by Rutherford Backscattering/Channelling Spectrometry. Cd ions are found to be incorporated in substitutional Al sites in the crystal and no significant diffusion is seen upon thermal annealing. The observed high solubility limit and site stability are prerequisite for using Cd as p-type dopant in AlN.

321

Medien als Lernform und die Trimediale Redaktion  

Directory of Open Access Journals (Sweden)

Full Text Available Der vorliegende Artikel beschreibt ein Konzept für eine handlungsorientierte Medienpädagogik im Bildungsbereich. Im Mittelpunkt steht dabei die SO!-Campusredaktion, die als Methode für expansives Lernen die Möglichkeit bietet, unabhängig von Thema oder Medium die Verantwortung für den Lernprozess in die Hände der Lernenden zu legen. Der Dokumentation von Reflexion über den Lernprozess wird dabei eine besondere Bedeutung zugesprochen. Gleichzeitig werden unterschiedliche mediale Gestaltungsmöglichkeiten (Audio/Radio, Video/Fernsehen und Zeitung – sowohl als Print- als auch als Onlinemedium vorgestellt, die durch das Konzept BYOD – bring your own device – auch einfach und niederschwellig im Bildungskontext umsetzbar sind. Dadurch ergeben sich innovative Möglichkeiten, einen Lernprozess sichtbar zu machen und gleichzeitig eine Grundlage für eine alternative Leistungsbeurteilung anzubieten. Die SO!-Campusredaktion wird derzeit an der Pädagogischen Hochschule Salzburg in Kooperation mit dem Communitysender FS1 und der Radiofabrik entwickelt und erprobt. Community Medien nehmen als MedienpartnerInnen eine bedeutende Stellung ein: Durch ihren offenen Zugang zu Know How und Equipment sowie durch die Möglichkeit, Medienproduktionen über die verfügbaren Distibutionskanäle (Radiofrequenz oder Sendeplatz einer breiten Bevölkerung zugänglich zu machen, gewinnt die Medienpädagogik einen wichtigen Mehrwert in ihrer schulischen und außerschulischen Arbeit. (Dieser Artikel knüpft an den Artikel "BYOD, Smartphonefilme und webbasierte Videoschnittprogramme" der Medienimpulse, Ausgabe 2/2014, an.

Wolf Hilzensauer

2015-01-01

322

MOSQUE ARCHITECTURE AS A SUSTAINABLE BUILDING IN URBAN (Case Study: Al Markas Al Islamic Mosque Makassar  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Mosque Architecture is a part of Islamic architecture. Mosque should be fused with elements of nature because its function as a place to pray to God who created the universe. Al Markas Al Islamic Makassar mosque is used as a center of Islamic aspirations of the people and the government to accommodate all the activities of moslems in Makassar. Through this function, the provision of Al Markas Al Islamic mosque began from the desire of Islamic societies in Makassar, which wants the Islamic center to be equipped with facilities and infrastructure as well as architectural, monumental buildings and structures that can be last for hundreds of years (continuous, blend with the environment, and also can be used by the public. Having regard to the function of a mosque especially at the Al Markas Al Islamic Makassar mosque, then the problem that arise is how the Al Markas Al Islamic mosque can be survived/sustainable  in order  to function  as a place  of worship  and  as a center  of Islam.  This research  is a descriptive qualitative research that is trying to generate data in the form of systematic and accurate picture of the object of study. The sustaiprophetlity  of Al Markas AL Islamic mosque can be known through the concept of Islam  in accordance with the view of Islam as well as the sustaiprophetlity of the buildings that seen in the spatial pattern of the mosque, appearance, natural lighting, natural ventilation, and user behavior of the mosque. Keywords: mosque architecture, sustaiprophetlity, view of Islam     Abstrak Arsitektur masjid merupakan bagian dari arsitektur Islam. Bangunan masjid sebaiknya dapat menyatu dengan unsur alam karena masjid difungsikan sebagai wadah dalam bersujud/sembahyang  kepada Allah SWT yang menciptakan alam semesta ini. Masjid Al Markas Al Islamic Makassar merupakan kompleks kegiatan Islam yang digunakan sebagai pusat aspirasi masyarakat  dan pemerintahan  yang dapat menampung  seluruh kegiatan  umat Islam di Makassar. Melalui fungsi inilah maka  pengadaan masjid Al Markas Al-Islamic bermula dari keinginan masyarakat Islam di kota Makassar, yang mana menginginkan pusat kegiatan Islam yang dilengkapi dengan sarana dan prasarana juga bangunannya monumental yang secara arsitektur dan struktur bisa bertahan sampai ratusan tahun (berkelanjutan, dan menyatu dengan lingkungannya  serta dapat digunakan  oleh masyarakat  luas. Dengan memperhatikan  fungsi masjid terutama pada masjid Al Markas Al Islamic Makassar maka permasalahan yang muncul adalah bagaimanakah arsitektur  masjid  Al  Markas  Al  Islamic  dapat  bertahan/berkelanjutan   agar  dapat  difungsikan  sebagai  tempat beribadah dan sebagai pusat kegiatan Islam. Penelitian ini merupakan penelitian deskriptif yang bersifar kualitatif yaitu penelitian yang berusaha menghasilkan data berupa gambaran yang sistematis dan akurat dari objek kajian. Keberlanjutan  masjid Al Markas Al Islamic dapat diketahui melalui penyatuan konsep masjid Al Markas Al Islamic sesuai  dengan  pandangan  Islam  serta  keberlanjutan  dilihat  pada  bangunan  yakni  pola  tata  ruang  masjid, penampilan, pencahayaan dan penghawaan alami serta perilaku pemakai masjid. Kata Kunci : Arsitektur masjid, keberlanjutan, pandangan Islam

Imriyanti Imriyanti

2013-12-01

323

Comments on optimization of the boron content in FeAl (40 at.% Al) alloys  

International Nuclear Information System (INIS)

In a recent paper, Webb, Juliet and Lefort indicated, based on tensile tests of two boron-doped FeAl alloys and one undoped FeAl alloy, that they had determined the optimum concentration of boron for good ductility to be 48 appm (12 wppm) in Fe-40Al (compositions given in atomic percent throughout). It is the author's view that this is not the case for the following reasons: (1) The Fe-40Al alloys studied by Webb et al. contained 42:4, (heat number-sign 1), 45.7 (heat number-sign 2) and 39.7 (heat number-sign 3) atomic percent Al. (2) The maximum solubility of an element may depend on the presence of other elements. (3) Other workers, notably Liu and George have obtained greater elongations in Fe-40Al in air (4.3%) than the 2.5% obtained by Webb et al. with a greater boron concentration (300 wppm as opposed to 12 wppm). Similarly, Crimp et al. found little difference in the tensile behavior of slow-cooled Fe-40Al with boron levels in the range 500 to 2000 wppm, with a ductility at 3% elongation that was comparable to the highest obtained by Webb et al. (4) Boron in FeAl presumably partitions between the lattice and the grain boundaries. (5) The grain size in the boron-free alloys studied by Webb et al. was larger at 54 ?m than in the boron-doped alloys (37 ?m and 27 ?m for the alloys containing 12 and 80 wppm B, respectively). (6) When tensile tests are performed on FeAl in air, the ductility is reduced due to water vapor. To some extent boron may ameliorate this esome extent boron may ameliorate this environmental effect. Thus, differences in ductility in air are not necessarily due to intrinsic behavior but may be due to a reduced environmental effect in boron-doped alloys. (7) Webb et al. conducted their tensile tests at a strain rate of 3 x 10-2s-1

324

Mg-doped Al-rich AlGaN alloys for deep UV emitters  

Science.gov (United States)

Mg doped Al-rich AlGaN epilayers with Al content as high as 0.7 is needed for obtaining deep UV LEDs with wavelengths shorter than 300 nm. This is one of the most crucial layers in deep UV LEDs and plays an important role for electron blocking and affects the hole injection into the active layer. Not only is this layer critical for the efficiency of deep UV LEDs, it could also introduce long wavelength emission components in UV LEDs. However, it is difficult to obtain high quality Mg doped Al-rich AlGaN epilayers and the resistivity of the grown films is usually extremely high. We report here on the growth, optical and electrical properties of Mg doped Al0.7Ga0.3N epilayers. Mg doped Al0.7Ga0.3N epilayers of high crystalline and optical qualities have been achieved after optimizing MOCVD growth conditions. Moreover, we have obtained a resistivity around 12,000 ? cm (near the theoretical limit with Mg doping) at room temperature and confirmed p-type conduction at elevated temperatures for optimized Mg-doped Al0.7Ga0.3N epilayers. The growth conditions of the optimized epilayer have been incorporated into deep UV LEDs with wavelength shorter than 300 nm. A significant enhancement in power output with a reduction in forward voltage, Vf, was obtained by employing this optimized Mg doped Al0.7Ga0.3N epilayer as an electron blocking layer. The long wavelength emission components in deep UV LEDs were also significantly suppressed. The fundamental limit for achieving p-type Al-rich AlGaN alloys is also discussed.

Nakarmi, Mim L.; Kim, Kyoung Hoon; Zhu, Kai; Lin, Jing Yu; Jiang, Hong Xing

2004-10-01

325

Corrosion behaviour of Al/Al3Ti and Al/Al3Zr functionally graded materials produced by centrifugal solid-particle method: Influence of the intermetallics volume fraction  

OpenAIRE

Intermetallic particles, Al3Ti and Al3Zr were formed in Al–5mass%Ti and Al–5mass%Zr alloys, respectively, by centrifugal casting, in order to create functionally graded materials (FGMs). At present, no information is available on the influence of the amount of intermetallics on the electrochemical properties of these alloys. In this paper, the corrosion resistance of Al/Al3Ti and Al/Al3Zr FGMs was investigated by open-circuit measurements, potentiodynamic polarization and electrochemi...

Ferreira, S. C.; Rocha, L. A.; Ariza, E.; Sequeira, P. D.; Watanabe, Yoshimi; Fernandes, J. C. S.

2011-01-01

326

Experimental analysis of the intermediary phases AlB2,AlB12 and TiB2 in the Al-B and Al-Ti-B systems  

International Nuclear Information System (INIS)

The phases AlB2,AlB12 and TiB2 were studied in Al-rich Al-B and Al-Ti-B alloys produced by several different sample fabrication methods. The samples were examined using light optical microscopy (LOM), energy dispersive X-ray spectroscopic analysis (EDS) and X-ray diffraction analysis (XRD). The results indicate that only a limited solubility of Al in TiB2 and Ti in AlB2 exists, hence a continuous compound (Al,Ti)B2 is not stable. (orig.)

327

Boron strengthening in FeAl  

Energy Technology Data Exchange (ETDEWEB)

The effect of boron on the strength of B2-structured FeAl is considered as a function of composition, grain size and temperature. Boron does not affect the concentrations of antisite atoms or vacancies present, with the former increasing and the latter decreasing with increasing deviation from the stoichiometric composition. When vacancies are absent, the strength increase per at. % B per unit lattice strain, {Delta}{sigma}/({Delta}c x {epsilon}) increases with increasing aluminum concentration, but when vacancies are present (>45 at. % Al), {Delta}{sigma}/({Delta}c x {epsilon}) decreases again. Boron increases grain size strengthening in FeAl. B strengthening is roughly independent of temperature up to the yield strength peak but above the point, when diffusion-assisted deformation occurs, boron strengthening increases dramatically.

Baker, I.; Li, X.; Xiao, H.; Klein, O.; Nelson, C. [Dartmouth Coll., Hanover, NH (United States). Thayer School of Engineering; Carleton, R.L.; George, E.P. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.

1998-11-01

328

Synthesis of intercalated Al-hydroxy-montmorillonite  

Directory of Open Access Journals (Sweden)

Full Text Available Montmorillonita procedente de Durango, México, de composición (Si3.88Al0.12(Al1.41Mg0.59O10(OH2(Ca0.07Mg0.11Na0.28K0.06, área superficial 42.07 m2g-1, espaciamiento d001 12.50 Å, y volumen de poro 0.002 cm3g-1, fue intercalada con el oligómero de Al. La arcilla modificada desarrolló un área superficial de 287.86 m2g-1, volumen de poro 0.103 cm3g-1, y espaciamiento d001 18.70 Å. Se deshidrata a 70 °C reduciendo el espaciamiento d001 a 17.29 Å; su deshidroxilación se inicia a 150 °C y a 300 °C perdió 1.92 % en peso, modificando d001 a 17.34 Å.

M. de Lourdes Ch\\u00E1vez-Garc\\u00EDa

2006-01-01

329

Hydrogenation properties of Mg-Al alloys  

DEFF Research Database (Denmark)

In this paper the properties of Mg-Al alloys in relation to hydrogen storage are reviewed. The main topics of this paper are materials preparation, hydrogen capacity, thermodynamics of hydride formation, and the kinetics of hydride formation and decomposition. Hydrogenation of Mg-Al leads to disproportionation with the formation of magnesium hydride and metallic aluminum as the final product. Experimental evidence renders this process reversible. It is observed that the enthalpy of hydride formation of magnesium is lowered upon alloying with Al due to a slightly endothermic disproportionation reaction. Further, it is found that the kinetics of hydrogenation, as well dehydrogenation, may be significantly improved by alloying compared to pure Mg. The expense of these improvements of the hydrogenation/dehydrogenation properties is a lower gravimetric hydrogen density in the hydrogenated product, (C) 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.

Andreasen, Anders

2008-01-01

330

Grain boundary characterization in Ni3Al  

International Nuclear Information System (INIS)

Grain boundaries in both pure and boron doped Ni3Al have been studied using a variety of electron microscopy techniques. Small angle boundary structures were examined in both bicrystal and polycrystalline specimens. Dislocations with Burgers vector a/2 right-angle 110 left-angle are observed in the presence of boron, while dislocations with Burgers vector a right-angle 100 left-angle are observed in the absence of boron. A possible explanation for this behaviour is the presence of a disordered layer at the interface in boron doped Ni3Al. The addition of boron to Ni3Al was seen to induce faceting of grain boundaries, and to afford the boundaries some protection from etching. Using electron backscatter diffraction patterns, the frequency of occurrence of grain boundary types was found to be unchanged by the addition of boron

331

MEGA. Higher energy-efficiency through systematic user information - Final report; MEGA. Mehr Energieeffizienz durch gezielte Anwenderinformationen - Schlussbericht  

Energy Technology Data Exchange (ETDEWEB)

Individuals are empowered to conserve energy and natural resources when provided with motivational and personalized information on its use. By presenting information about the energy consumption from the home's energy meters along with recommended actions, the residential customer becomes aware of how in/efficiently energy is consumed within his home and can decide on how to act to conserve. This information can provide an accurate metric of how effective a conservation action is even to inhabitants that are not yet knowledgeable about or self-motivated by the monetary and ecologic rewards of conserving. This project was designed to build knowledge on technically and economically feasible ways to create an awareness of energy (especially electricity) for the sake of conservation. Specifically, it implements an exemplar prototype of a highly effective energy feedback system that is an interactive, real-time, in-home display. Toward this goal, four system architecture configuration proposals, a set of system requirements, and ideal system features are synthesized; they are based on the results of the research that evaluates effectiveness of existing energy-efficiency and -conservation methods and studies related technologies. Three of the four systems proposed represent energy technologies expected to be available within the next decade. The fourth system proposal is a demonstration prototype designed for implementation in the iHomeLab. This prototype is an open, modular, robust, cross-platform software framework that collects data, processes, and presents it interactively and visually on hardware available in most households. The results of this project both indicate that the creation of such energy feedback systems appear beneficial and also provide guidelines for their design. However, further development of infrastructure and elaboration of design is foreseen as necessary for this system to be suitable for mass deployment. (author)

Fercu, M.; Kistler, R. [Hochschule Luzern Technik und Architektur, CEESAR - iHomeLab, Horw (Switzerland); Egli, A. [Hochschule Luzern Technik und Architektur, ISIS, Horw (Switzerland); Gallati, J. [Hochschule Luzern Technik und Architektur, Wirtschaft, Horw (Switzerland)

2010-09-15

332

More safety in the medium-voltage network by casting resin transformers; Mehr Sicherheit im Mittelspannungs-Netz durch Giessharztransformatoren  

Energy Technology Data Exchange (ETDEWEB)

Drying transformers or casting resin transformers are employed at places where oil-isolated transformers may not be used for safety reasons. Characteristics such as operational safety and long life span ensure greatest possible safety with wind power stations, in water protection zones, in multi-storied buildings and in each subway railway station or rapid-transit railway station. A further substantial characteristic is in demand: the very good fire behaviour. Drying transformers not only are difficulty inflammable, but also go out by one self. In addition the transformers are maintenance-free, have a compact design, are easily installable and make no high requirements to the maintenance staff. Drying transformers are ecologically beneficial and can be recycled well. Therefore, drying transformers are indispensable in the public and industrial power supply.

Tschaetsch, H.U.

2006-07-15

333

Urbane Neoliberalisierung – ein Plädoyer für etwas mehr Differenz. Kommentar zu Margit Mayers „Urbane soziale Bewegungen in der neoliberalisierenden Stadt“  

Directory of Open Access Journals (Sweden)

Full Text Available [Dieser Artikel ist Teil einer Debatte] In ihrem Beitrag nimmt Margit Mayer die neoliberale Stadt und urbane soziale Bewegungen in globaler Perspektive in den Blick. Die auch von Margit Mayer maßgeblich vorangetriebene Diskussion, die sich in der letzten Dekade zwischen Urban Studies, lokaler Politik- und Bewegungsforschung durchaus konstruktiv am „actually existing neoliberalism“ (Brenner/Theodore 2002 abgearbeitet hat, wird mit Blick auf die dieser Diskussion ursprünglich inneliegenden regulationstheoretischen Herausforderungen kritisch gegengelesen. Der Kommentar verweist zudem auf einige theoretische Leerstellen, die in der Folge zu empirischen Ungenauigkeiten führen.

Volker Eick

2013-07-01

334

Forming simulation + innovative heater concepts = greater energy-efficiency; Umformsimulation fuehrt zusammen mit innovativen Erwaermerkonzepten zu mehr Energieeffizienz  

Energy Technology Data Exchange (ETDEWEB)

Innovative heating strategies based on multi-converter-systems allow a robust and energy efficient process control for hot forging processes. Taking into account these state of the art concepts in Simufact.forming, a software solution for metal forming process simulation, leads to significant quality improvement in terms of simulation results. Undreamed-of possibilities open up due to the coupling of those two technologies to design optimized manufacturing processes robust and faultless. (orig.)

Wohlmuth, Michael; Schafstall, Hendrik [simufact engineering gmbh, Hamburg (Germany)

2010-03-15

335

Nature's powerhouse. Innovative technologies for a more sustainable future; Kraftwerk Natur. Innovative Technologien fuer mehr Nachhaltigkeit  

Energy Technology Data Exchange (ETDEWEB)

Across the globe, our hunger for energy continues to grow. Yet climate change and dwindling fossil fuel supplies are forcing us to rethink our energy policy and turn increasingly to renewable resources. Achieving a sustainable energy mix and eco-friendly mobility options demands innovative technologies. And that is where Linde's gas and plant engineering specialists come in, developing efficient processes and providing crucial momentum for a greener future. (orig.)

Anon.

2013-09-01

336

Modernisation of hydrogenerators. Upgrading of power plants for more efficiency; Modernisierung von Hydrogeneratoren. Kraftwerks-Upgrade fuer mehr Effizienz  

Energy Technology Data Exchange (ETDEWEB)

Ever since the construction of the first alternating current hydroelectric power plant with a performance of 12.5 kW in the year 1882, the number and performance of hydroelectric power plants had increased substantially. For example, the hydroelectric power plant at the Three Gorges Dam in the People's Republic of China has a total performance of 22,500 MW. The isolation systems of the hydrogenerators have a limited lifetime and have to be exchanged after fifty years usually. Under this aspect, the authors of the contribution under consideration reports on the upgrading of hydrogenerators for more efficiency.

Allen, John

2012-07-01

337

Prognostic factors in ALS: A critical review  

OpenAIRE

We have performed a systematic review to summarize current knowledge concerning factors related to survival in ALS and to evaluate the implications of these data for clinical trials design. The median survival time from onset to death ranges from 20 to 48 months, but 10–20% of ALS patients have a survival longer than 10 years. Older age and bulbar onset are consistently reported to have a worse outcome. There are conflicting data on gender, diagnostic delay and El Escorial criteria. The rat...

Chio, Adriano; Logroscino, Giancarlo; Hardiman, Orla; Swingler, Robert; Mitchell, Douglas; Beghi, Ettore; Traynor, Bryan G.

2009-01-01

338

CONTRIBUCIONES DE LA LOGÍSTICA AL DESARROLLO SOSTENIBLE  

Directory of Open Access Journals (Sweden)

Full Text Available Se pretende con este documento presentar algunas reflexiones de la forma como la logística puede ayudar al desarrollo sostenible de las organizaciones. Para este propósito se han consultado fuentes bibliográficas nacionales e internacionales, analizando algunas estadísticas. Se muestra el estado actual de la logística en Colombia. Al final, se relacionan valiosas conclusiones que pueden tomarse como reflexión y punto de partida en el apasionante mundo de los sistemas logísticos y su impacto en la productividad y competitividad de las empresas actuales con tendencia a los procesos de producción y distribución más limpios y sostenibles.

DIANA PAOLA BALLESTEROS RIVEROS

2009-01-01

339

Das „neue“ Private. Familie als intime Gefühlsgemeinschaft  

Directory of Open Access Journals (Sweden)

Full Text Available Methodisch versteht sich die Habilitationsschrift als Beitrag zur Rekonstruktion moderner politischer Philosophie. Als zentraler Ansatzpunkt dient das Familienkonzept von Rousseau, seine Schriften werden auf Geschlechterkonstruktionen und bürgerliche Geschlechterordnungen hin untersucht. Grundanliegen der Studie ist es, Bürgerlichkeit unter ihrem zentralen Aspekt des Privaten zu betrachten und in den Kontext moderner kontraktualistischer Philosophie zu stellen. Die Autorin vertritt die Ausgangsthese, Rousseau müsse eine „Schlüsselstellung“ (S. 9 in der Geschichte der bürgerlichen Geschlechter- und Familienordnung zugesprochen werden. Durch ihn sei die Trennung des Privaten vom Öffentlichen eingeleitet und festgeschrieben worden.

Regina Harzer

2006-11-01

340

ANÁLISIS ESTRUCTURAL PROSPECTIVO APLICADO AL SISTEMA LOGÍSTICO  

Directory of Open Access Journals (Sweden)

Full Text Available La intención de este trabajo es compartir con los lectores una forma de hacer análisis estructural prospectivo al sistema logístico. Para ello, se hace un breve recorrido histórico de este método de escenarios, conociendo los aportes de Godet y Duperrin, luego se presenta una breve descripción del método con sus objetivos y fases, la identificación de variables en el sistema logístico del sector de las confecciones en Pereira, localización de las relaciones en la matriz de análisis estructural, la búsqueda de las variables clave, planos de motricidad y al final se exponen para reflexión algunas conclusiones.

DIANA PAOLA BALLESTEROS RIVEROS

2008-01-01

341

Fatigue behaviour of Al-matrix composites  

Energy Technology Data Exchange (ETDEWEB)

The cyclic deformation behaviour and fatigue lives of different Al-matrix composites reinforced by alumina reinforcements were investigated under total strain control mode at room temperature. The composites differ in either matrix strength (peak aged vs. overaged AA6061 alloy and soft Al99.85, respectively) and/or type of reinforcement (particles, Saffil short fibres and Almax continuous fibres). The damage evolution was characterized by compliance experiments within individual stress-strain hysteresis loops. The differences of the material behaviour are discussed with respect to matrix strength and reinforcement geometry. (Abstract Copyright [2004], Wiley Periodicals, Inc.)

Hartmann, O. [Institut fuer Werkstoffwissenschaften, Lehrstuhl I, Universitaet Erlangen-Nuernberg, Martensstr. 5, D-91058 Erlangen (Germany); Herrmann, K.; Biermann, H. [Institut fuer Werkstofftechnik, Technische Universitaet Bergakademie Freiberg, Gustav-Zeuner-Str. 5, D-09599 Freiberg (Germany)

2004-07-01

342

Niedermolekulare Verbindungen aus Spinnen als chemische Sensoren  

DEFF Research Database (Denmark)

Spinnen sind für viele Ökosysteme wichtig, und als Hauptfeinde von Insekten verfügen sie über eine Fülle von niedermolekularen Naturstoffen mit faszinierenden biologischen Wirkungen. Die Isolierung und die biologische Charakterisierung dieser Verbindungen sind wohlbekannt, aber erst kürzlich wurden sie als Leitstrukturen für die Entwicklung, Synthese und biologische Untersuchung synthetischer Analoga verwendet. Weit weniger erforscht sind hingegen Verbindungen, die der Kommunikation von Spinnen dienen. Vor kurzem wurden jedoch auf dem Gebiet der Pheromone und Allomone aus Spinnen neue Erkenntnisse erhalten, die wir hier zusammenfassen und mit früheren Ergebnissen in Zusammenhang bringen. Abschließend geben wir einen Ausblick auf künftige Untersuchungen an dieser Art von Verbindungen.

Olsen, Christian Adam; Kristensen, Anders S.

2011-01-01

343

Diffusion bonding of gamma-TiAl using modified Ti/Al nanolayers  

International Nuclear Information System (INIS)

Highlights: ? Ti/Al multilayers are promising interlayers for getting joins between titanium aluminides. ? When Ti/Al multilayers are doped with Ag or Cu it is observed a higher reactivity of the multilayers. ? A doped Ti/Al multilayer decreases the temperature of the process and the quality of the bonding increases. - Abstract: Solid state diffusion bonding has been successfully employed to join ?-TiAl alloys. Processed in vacuum, at high temperature and pressure, the thin interfaces and the lack of structural discontinuity across the interface are the main advantage of this joining technique. An interlayer made of alternated Ti and Al nanometric layers that increases the diffusivity at the joint interface, was used in order to assist the bonding process of ?-TiAl alloys. The use of Ti/Al interlayer has efficiently reduced the joining temperature. Sound joints have been achieved at a temperature of 900 °C under a pressure of 50 MPa in vacuum. In the present work Cu was added as third element to the Ti/Al multilayers and its effect improved the bonding quality. The interface microstructure was studied by scanning and transmission electron microscopy.

344

Oxidation kinetics of Zn 5 Al and Zn 55 Al alloys doped by beryllium  

International Nuclear Information System (INIS)

This article is devoted to influence of temperature and chemical composition on oxidation kinetics of Zn 5 Al and Zn 55 Al alloys doped by beryllium in solid condition. Thus, the thermogravimetry method with continuous weighting of samples is used. Zink, aluminium and its alloy with beryllium are used as initial materials. The oxidation true velocity as well as apparent activation energy are found.

345

Melting, Processing, and Properties of Disordered Fe-Al and Fe-Al-C Based Alloys  

Science.gov (United States)

This article presents a part of the research work conducted in our laboratory to develop lightweight steels based on Fe-Al alloys containing 7 wt.% and 9 wt.% aluminum for construction of advanced lightweight ground transportation systems, such as automotive vehicles and heavy-haul truck, and for civil engineering construction, such as bridges, tunnels, and buildings. The melting and casting of sound, porosity-free ingots of Fe-Al-based alloys was accomplished by a newly developed cost-effective technique. The technique consists of using a special flux cover and proprietary charging schedule during air induction melting. These alloys were also produced using a vacuum induction melting (VIM) process for comparison purposes. The effect of aluminum (7 wt.% and 9 wt.%) on melting, processing, and properties of disordered solid solution Fe-Al alloys has been studied in detail. Fe-7 wt.% Al alloy could be produced using air induction melting with a flux cover with the properties comparable to the alloy produced through the VIM route. This material could be further processed through hot and cold working to produce sheets and thin foils. The cold-rolled and annealed sheet exhibited excellent room-temperature ductility. The role of carbon in Fe-7 wt.% Al alloys has also been examined. The results indicate that Fe-Al and Fe-Al-C alloys containing about 7 wt.% Al are potential lightweight steels.

Satya Prasad, V. V.; Khaple, Shivkumar; Baligidad, R. G.

2014-09-01

346

Synthesis of nanostructured AlN by solid state reaction of Al and diaminomaleonitrile  

Energy Technology Data Exchange (ETDEWEB)

The solid state reaction of diaminomaleonitrile (DAMN) with aluminum via both mechanochemical and thermal treatment routes was studied by X-ray diffraction and Fourier transform infrared spectroscopy. During the milling process, the reaction starts with the deammoniation of the DAMN molecules, followed by the formation of nanostructured AlN powder as the main solid product after milling for 7 h. The reactivity of the mixed powder was also investigated during the conventional thermal treatment process using differential scanning calorimetry, derivative thermogravimetry and thermogravimetric analysis. The results reveal that DAMN starts to polymerize at 192 Degree-Sign C by the elimination of the amine groups. Furthermore, increasing the annealing temperature leads to the formation of a nitrogen-containing carbonaceous material with the structure similar to non-crystalline carbon. However, no evidence for the formation of AlN was observed in the annealed samples even at temperatures as high as the Al melting point. - Graphical abstract: AlN nanoparticles obtained after milling of Al and diaminomaleonitrile (DAMN) for 12 h. Highlights: Black-Right-Pointing-Pointer Solid state reaction of diaminomaleonitrile (DAMN) with Al was studied via mechanochemical and thermal treatment routs. Black-Right-Pointing-Pointer Nanocrystalline AlN was successfully synthesized by the mechanochemical process. Black-Right-Pointing-Pointer The C/N material was formed by polymerization of DAMN during the thermal treatment process. Black-Right-Pointing-Pointer No reaction between DAMN and Al was detected during the thermal treatment method.

Rounaghi, S.A., E-mail: s.a.rounaghi@gmail.com [Department of Materials Engineering, Ferdowsi University of Mashhad. P.O. Box no. 91775-1111, Mashhad (Iran, Islamic Republic of); IFW Dresden, Institut fuer Komplexe Materialien, Postfach 27 01 16, Dresden D-01171 (Germany); Eshghi, H., E-mail: heshghi@ferdowsi.um.ac.ir [Department of Chemistry, Ferdowsi University of Mashhad. P.O. Box no. 91775-1436, Mashhad (Iran, Islamic Republic of); Kiani Rashid, A.R.; Vahdati Khaki, J. [Department of Materials Engineering, Ferdowsi University of Mashhad. P.O. Box no. 91775-1111, Mashhad (Iran, Islamic Republic of); Samadi Khoshkhoo, M.; Scudino, S. [IFW Dresden, Institut fuer Komplexe Materialien, Postfach 27 01 16, Dresden D-01171 (Germany); Eckert, J. [IFW Dresden, Institut fuer Komplexe Materialien, Postfach 27 01 16, Dresden D-01171 (Germany); TU Dresden, Institut fuer Werkstoffwissenschaft, Dresden D-01062 (Germany)

2013-02-15

347

Optical investigation on the valence band structure of AlGaN with low Al content  

Energy Technology Data Exchange (ETDEWEB)

For the binary semiconductors GaN and AlN, the crystal field splitting determining the valence band structure changes from {approx}+20 meV (GaN) to {approx}-200 meV (AlN), whereas the spin orbit splitting should remain constant at {approx} 20 meV. Therefore, for unstrained AlGaN ternary layers an interchange of the character of the topmost valence band from {gamma}{sub 9} to {gamma}{sub 7} is theoretically expected for an Al content in the range of 5-10%, manifesting itself mainly in a change of polarization of optical transitions. Strain in epitaxial layers alters the situation and shifts this crossing point. Literature reports experimental values ranging from 20% to 75% Al for the crossover. We present results of temperature dependent photoluminescence and reflectivity experiments on AlGaN layers with Al content ranging from 0 to 30%, and find different contributions from free and bound excitons. The Al content and strain were determined from multiple HRXRD reflections, and entered in a 6 x 6 k.p model calculation. We discuss our experimental spectra on the basis of this calculation.

Meisch, Tobias; Neuschl, Benjamin; Thonke, Klaus [Institut of Quantum Matter, Ulm University, 89069 Ulm (Germany); Lipski, Frank; Forghani, Kamran; Scholz, Ferdinand [Institut of Optoelectronics, Ulm University, 89069 Ulm (Germany); Feneberg, Martin [Institut fuer Experimentelle Physik, Abt. Materialphysik, Otto-von-Guericke-Universitaet Magdeburg, Universitaetsplatz 2, 39106 Magdeburg (Germany)

2011-07-01

348

Alloy inhomogeneity and carrier localization in AlGaN sections and AlGaN/AlN nanodisks in nanowires with 240-350 nm emission  

Science.gov (United States)

We present structural and optical studies of AlGaN sections and AlGaN/AlN nanodisks (NDs) in nanowires grown by plasma-assisted molecular beam epitaxy. The Al-Ga intermixing at Al(Ga)N/GaN interfaces and the chemical inhomogeneity in AlGaN NDs evidenced by scanning transmission electron microscopy are attributed to the strain relaxation process. This interpretation is supported by the three-dimensional strain distribution calculated by minimizing the elastic energy in the structure. The alloy inhomogeneity increases with the Al content, leading to enhanced carrier localization signatures in the luminescence characteristics, i.e., red shift of the emission, s-shaped temperature dependence, and linewidth broadening. Despite these effects, the emission energy of AlGaN/AlN NDs can be tuned in the 240-350 nm range with internal quantum efficiencies around 30%.

Himwas, C.; den Hertog, M.; Dang, Le Si; Monroy, E.; Songmuang, R.

2014-12-01

349

27Al-NQR Study on Novel Phase Transition in CeOs2Al10  

International Nuclear Information System (INIS)

We have performed 27Al-NQR measurements in CeOs2Al10 which exhibits a novel phase transition at T0=29 K The NQR parameters determined for all the Al sites in ambient pressure were compared with those in CeRu2Al10 with T0=27 K and CeFe2Al10 with no phase transition. The distinct NQR splitting just below T0=32.5 K under pressure 0.66 GPa ensures an enhancement of T0 and a homogeneous transition. Despite the increase of T0, the nuclear spin-lattice relaxation rate 1/Tl is suppressed over whole range of temperature than in ambient pressure. The characteristic features of no critical slowing down at T0 and of the remarkable decrease of 1/T1T starting at T > T0 become prominent under pressure, suggesting an approach to Kondo semiconductor in a valence fluctuation regime.

350

27Al-NQR Study on Novel Phase Transition in CeOs2Al10  

Science.gov (United States)

We have performed 27Al-NQR measurements in CeOs2Al10 which exhibits a novel phase transition at T0=29 K The NQR parameters determined for all the Al sites in ambient pressure were compared with those in CeRu2Al10 with T0=27 K and CeFe2Al10 with no phase transition. The distinct NQR splitting just below T0=32.5 K under pressure 0.66 GPa ensures an enhancement of T0 and a homogeneous transition. Despite the increase of T0, the nuclear spin-lattice relaxation rate 1/Tl is suppressed over whole range of temperature than in ambient pressure. The characteristic features of no critical slowing down at T0 and of the remarkable decrease of 1/T1T starting at T > T0 become prominent under pressure, suggesting an approach to Kondo semiconductor in a valence fluctuation regime.

Matsumura, M.; Inagaki, T.; Kato, H.; Nishioka, T.; Tanida, H.; Sera, M.

2012-12-01

351

Structural and local electrical properties of AlInN/AlN/GaN heterostructures  

Science.gov (United States)

GaN layers and Al1-xInxN/AlN/GaN heterostructures have been studied by scanning probe microscopy methods. Threading dislocations (TDs), originating from the GaN (0 0 0 1) layer grown on sapphire, have been investigated. Using Current-Atomic Force Microscopy (C-AFM) TDs have been found to be highly conductive in both GaN and AlInN, while using semi-contact AFM (phase-imaging mode) indium segregation has been traced at TDs in AlInN/AlN/GaN heterostructures. It has been assessed that In segregation is responsible for high conductivity at dislocations in the examined heterostructures.

Minj, A.; Cavalcoli, D.; Cavallini, A.

2012-08-01

352

Electrical Characteristics of Ti/Al Contacts on AlInN:Mg/GaN Heterostructures  

Science.gov (United States)

The electrical characteristics of a Ti/Al metal contact on Mg-doped AlInN/GaN heterostructures were investigated using a transmission line model. The as-deposited Ti/Al contact exhibited near Ohmic contact with a specific contact resistance of 1.78×10-2 ? cm2, while the thermal annealing performed at 600 °C led to better Ohmic contact with a contact resistance of 9.38×10-4 ? cm2. This could be attributed to the formation of a direct Ohmic path connecting the contact and the two-dimensional electron gas beneath an AlInN:Mg barrier upon thermal annealing, namely, a spike contact through the indiffusion of Al as verified from secondary ion mass spectroscopy. Current-voltage-temperature measurements showed an insignificant temperature dependence in both the sheet resistance and the contact resistance, which seemed to be associated with the distinctive feature of the spike contact.

Kim, Seongjun; Kim, Hee Jin; Choi, Suk; Lochner, Zachary; Ryou, Jae-Hyun; Dupuis, Russell D.; Ahn, Kwang-Soon; Kim, Hyunsoo

2013-10-01

353

Serious Flaws in Korf et al.'s Analysis on Time Complexity of A*  

CERN Document Server

Understanding the effect of a heuristic on the time complexity of the well-known A* search algorithm has been a subject of a large research body in AI. Among those researches is Korf et al.'s analysis (Korf & Reid, 1998; Korf et al., 2001; Korf, 2000a; Korf, 2000b), which concluded that the effect of a heuristic is to reduce the effective depth rather than effective branching factor. Since this conclusion conflicts with both previous analysis and recent analysis by other authors, we try to investigate the causes of such contradictions and finally find out that Korf et al.'s analysis has many serious flaws from which their main conclusion was drawn.

Dinh, Hang

2008-01-01

354

Properties and structure of oxidized coatings deposited onto Al-Cu and Al-Mg alloys  

Science.gov (United States)

The results of new studies of creating protective oxide coatings based on Al2O3 (Si, Mn) and deposited onto aluminum alloys using electrolyte-plasma oxidation are presented. An analysis is performed by scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), X-ray diffraction, Rutherford backscattering of 4He+ and protons, nanoindentation, scratching, friction coefficient measurements, and acoustic emission measurements. The results demonstrate that the deposited coatings have a high quality, hardness, and wear resistance and a low thermal diffusivity. Apart from Al2O3, the coatings are found to have Si, Mn, C, and Ca. The stoichiometry of the coatings is determined. The density and hardness of the coatings are close to those of ?-Al2O3 in the coating on an Al-Cu (D-16) substrate, and these values of the coating on an Al-Mg (S006) are lower by a factor of 1.5.

Pogrebnyak, A. D.; Kylyshkanov, M. K.; Tyurin, Yu. N.; Kaverina, A. Sh.; Yakushchenko, I. V.; Borisenko, A. A.; Postol'ny, B. A.; Kulik, I. A.

2012-06-01

355

In situ microscopy of rapidly heated nano-Al and nano-Al/WO3 thermites  

International Nuclear Information System (INIS)

The initiation and reaction mechanism of nano-Al and nano-Al thermites in rapid heating environments is investigated in this work. A semiconductor-based grid/stage was used, capable of in situ heating of a sample from room temperature to 1473 K, and at a rate of 106 K/s, inside an electron microscope. Nano-Al was rapidly heated in a transmission electron microscope, and before and after images indicate that the aluminum migrates through the shell, consistent with a diffusion-based mechanism. A nano-Al/WO3 composite was then heated in a scanning electron microscope. The results indicate that a reactive sintering mechanism is occurring for the nano-Al/WO3 thermite, as the products are found to be in surface contact and significantly deformed after the heating pulse.

356

Microstructure and nanoindentation hardness of Al/Al3Sc multilayers  

International Nuclear Information System (INIS)

In the present paper, we discuss the fabrication, characterization and mechanical properties of a unique multilayer system constructed of aluminum and scandium. Thin film deposition techniques have been used to create high-quality polycrystalline multilayered films consisting of inherently soft Al layers (6-100 nm thick) separated by thin (0.5-5 nm) layers of Al3Sc. We use X-ray diffraction, transmission electron microscopy and in situ wafer curvature to characterize the microstructure and intermixing of the Al/Al3Sc multilayer films produced by sputter deposition for this work. The accompanying hardness results show that layering with nanoscale coherent Al3Sc layers increases the hardness by between 200 and 500% over that of a pure aluminum film

357

An impedance study of complex Al/Cu-Al2O3 electrode  

International Nuclear Information System (INIS)

Electrochemical impedance spectroscopy (EIS) was used to investigate different Cu deposition regimes on Al surface obtained by internal electrolysis and to characterize properties of fabricated electrodes. EIS experimental data confirmed that Cu deposition by internal electrolysis is realized and the complex electrode system is obtained. The main difficulty in preparation of Al/Cu electrodes is to prevent aluminium oxidation before and during electrochemical deposition of Cu particles. In this work NaCl, CH3COONa, K2SO4, mono- and diammonium citrate electrolytes were examined to determine their suitability for impedance measurements. Al/Cu-Al2O3 electrode composition was approved by equivalent circuit analysis, optical and scanning electron microscope methods. The most optimal Cu deposition mode using internal electrolysis was determined. The obtained results are promising for future electrochemical fabrication of nanostructures directly on Al surfaces by internal electrolysis.

358

The anodic and cathodic dissolution of Al and Al-Cu-Mg alloy  

Energy Technology Data Exchange (ETDEWEB)

Atomic emission spectroelectrochemistry (AESEC) was used to monitor the release of Al from 99.99% aluminum (1199 alloy) and Al, Mg, and Cu from 2024 Al alloy in 30 g/l NaCl electrolyte as a function of pH. The cathodic dissolution of Al was demonstrated and attributed to an increase in the pH at the interface due to the water reduction reaction. The dissolution of Mg was also observed but was a more complex function of current probably depending on the interfacial pH and the Al dissolution rate. The detachment of copper-rich particles was observed as very rapid spectroscopic emission transients (peak width < 10 ms).

Mokaddem, M.; Volovitch, P. [Laboratoire de physicochimie des surfaces, UMR7045, Ecole Nationale Superieure de Chimie de Paris, ParisTech, 11, rue Pierre et Marie Curie, Paris (France); Rechou, F.; Oltra, R. [Institut CARNOT de Bourgogne, Electrochimie Interfaciale-Corrosion, UMR5209, Universite de Bourgogne, Dijon (France); Ogle, K., E-mail: kevin-ogle@enscp.f [Laboratoire de physicochimie des surfaces, UMR7045, Ecole Nationale Superieure de Chimie de Paris, ParisTech, 11, rue Pierre et Marie Curie, Paris (France)

2010-04-15

359

The anodic and cathodic dissolution of Al and Al-Cu-Mg alloy  

International Nuclear Information System (INIS)

Atomic emission spectroelectrochemistry (AESEC) was used to monitor the release of Al from 99.99% aluminum (1199 alloy) and Al, Mg, and Cu from 2024 Al alloy in 30 g/l NaCl electrolyte as a function of pH. The cathodic dissolution of Al was demonstrated and attributed to an increase in the pH at the interface due to the water reduction reaction. The dissolution of Mg was also observed but was a more complex function of current probably depending on the interfacial pH and the Al dissolution rate. The detachment of copper-rich particles was observed as very rapid spectroscopic emission transients (peak width < 10 ms).

360

Al2O3 adherence on CoCrAl alloys  

International Nuclear Information System (INIS)

Adherence of protective oxides on NiCrAl and CoCrAl superalloys has been promoted by a dispersion of a highly oxygen reactive element or its oxide being produced within the protection system. Two aspects of this subject are investigated here: the use of Al2O3 as both the dispersion and protective oxide; and the production of an HfO2 dispersion while simultaneously aluminizing the alloy. It was found that an Al2O3 dispersion will act to promote the adherence of an external scale of Al2O3 to a degree comparable to previously tested dispersions and an HfO2 dispersion comparable to that produced by a Rhines pack treatment is produced during aluminization

361

Temperature dependence of the activity of Al in dilute Ni(Al) solid solutions  

International Nuclear Information System (INIS)

Activities of dilute Al solid solutions in Ni are determined from a first-principles approach. Both thermal lattice vibration and electronic contributions to free energies are considered and compared. Vibrational contributions tend to dominate the temperature dependencies of the free energies, though electron thermal effects are significant. Calculations show opposing temperature trends for the formation enthalpies and entropies, leading to a partial cancellation of their role in the overall energetics. Nevertheless, their remaining temperature effects are strong. Over the temperature range, 400 K< T<1700 K, the Al activity coefficient varies by 15 orders of magnitude, due to the relative strength of Al-Ni and Al-Al bonds. The Ni activity coefficient only varies less than 4% over the same range. Calculational results compare well with available experimental data. The thermodynamic principles elucidated from the calculations are used to provide a fundamental interpretation

362

Analysis of interface trap states in InAlN/AlN/GaN heterostructures  

Science.gov (United States)

Gate-source frequency-dependent capacitance and conductance measurements were performed on the In0.17Al0.83N/AlN/GaN heterostructure field-effect transistor with side-Ohmic contacts to study the characteristics of trap states at the interface between InAlN and GaN. The values of interface trap state density and time constant were determined to be (0.96-3.36) × 1013 cm-2 eV-1 and (0.29-1.61) ?s, respectively. We calculated the strain in the InAlN barrier layer under the gate and found that the InAlN barrier layer was compressively strained with the in-plane strain of 1.31%. This is a possible reason for such a high interface trap state density which is not as low as supposed in the lattice-matched heterostructures.

Zhou, Yang; Lin, Zhaojun; Luan, Chongbiao; Zhao, Jingtao; Yang, Qihao; Yang, Ming; Wang, Yutang; Feng, Zhihong; Lv, Yuanjie

2014-09-01

363

Superstructures on thin Al 2O 3 grown on Ni 3Al(0 0 1)  

Science.gov (United States)

Thin ordered layers of Al 2O 3 grown on a metallic Ni 3Al(0 0 1) substrate were studied using UHV STM and LEED. The oxidation of the substrate at 800 K and 1100 K forms different structural phases of Al 2O 3. Oxidation of Ni 3Al(0 0 1) at 800 K leads to a simple surface pattern, while oxidation at 1100 K results in a variety of surface patterns revealing superimposed quasi-periodic superstructures larger than expected from a simple moiré model. Atomic resolution achieved with STM on the Al 2O 3 surface allows us to determine all possible mutual orientations of the crystalline lattices. The spectroscopic STM d I/d V plots indicated different electronic properties at various points on the oxide superstructure. We conjecture that they can be attributed to ordering of structural patches distributed in a regular way.

Kurnosikov, O.; Flipse, C. F. J.; Swagten, H. J. M.; Koopmans, B.; de Jonge, W. J. M.

2006-09-01

364

Bonding characters of Al-containing bulk metallic glasses studied by 27Al NMR  

International Nuclear Information System (INIS)

We report very small 27Al metallic shifts in a series of Cu-Zr-Al bulk metallic glasses. This observation and the Korringa type of spin-lattice relaxation behavior suggest that s-character wavefunctions weakly participate in bonding and opens the possibility of enhanced covalency (pd hybridization) with increasing Al concentration, in good agreement with elastic constants and hardness measurements. Moreover, ab initio calculations show that this bonding character originates from the strong Al 3p band and Zr 4d band hybridization since their atomic energy levels are closer to each other while the Al 3s band is localized far below the Fermi level. This study might provide a chemical view for understanding flow and fracture mechanisms of these bulk glass-forming alloys.

365

Atomic structure of Zr-Cu-Al and Zr-Ni-Al amorphous alloys  

Energy Technology Data Exchange (ETDEWEB)

We report on the atomic structure via pair distribution function (PDF) analysis of metallic glasses of the Zr-Cu-Al and Zr-Ni-Al families. The PDFs were evaluated from the X-ray diffraction data. Transmission X-ray diffraction spectra of the investigated samples were measured using monochromatic, high-energy synchrotron radiation. In this work we demonstrate the effect of composition on the pair distribution functions. A variation of first PDF peak shape was observed on modification of Cu and Al content. A split of the first PDF peak was found to be more pronounced in Zr-Ni-Al than in Zr-Cu-Al glasses suggesting differences in their atomic structures.

Antonowicz, J. [Faculty of Physics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw (Poland); SIMAP-LTPCM, Institut National Polytechnique de Grenoble, BP 75, 38402 St-Martin-d' Heres Campus (France)], E-mail: antonowi@if.pw.edu.pl; Louzguine-Luzgin, D.V. [WPI Advaced Institute for Materials Research, Tohoku University, Katahira 2-1-1, Aoba-Ku, Sendai 980-8577 (Japan); Yavari, A.R. [SIMAP-LTPCM, Institut National Polytechnique de Grenoble, BP 75, 38402 St-Martin-d' Heres Campus (France); European Synchrotron Radiation Facility, 6 rue Jules Horowitz, BP220, 38043 Grenoble Cedex (France); Georgarakis, K. [SIMAP-LTPCM, Institut National Polytechnique de Grenoble, BP 75, 38402 St-Martin-d' Heres Campus (France); Stoica, M. [IFW Dresden, Institute for Complex Materials, P.O. Box 270116, D-01171 Dresden (Germany); Vaughan, G. [European Synchrotron Radiation Facility, 6 rue Jules Horowitz, BP220, 38043 Grenoble Cedex (France); Matsubara, E. [Faculty of Engineering, Kyoto University, Kyoto University, Kyoto 606-8511 (Japan); Inoue, A. [WPI Advaced Institute for Materials Research, Tohoku University, Katahira 2-1-1, Aoba-Ku, Sendai 980-8577 (Japan)

2009-03-05

366

Atomic structure of Zr-Cu-Al and Zr-Ni-Al amorphous alloys  

International Nuclear Information System (INIS)

We report on the atomic structure via pair distribution function (PDF) analysis of metallic glasses of the Zr-Cu-Al and Zr-Ni-Al families. The PDFs were evaluated from the X-ray diffraction data. Transmission X-ray diffraction spectra of the investigated samples were measured using monochromatic, high-energy synchrotron radiation. In this work we demonstrate the effect of composition on the pair distribution functions. A variation of first PDF peak shape was observed on modification of Cu and Al content. A split of the first PDF peak was found to be more pronounced in Zr-Ni-Al than in Zr-Cu-Al glasses suggesting differences in their atomic structures

367

Different magnetic behaviour of the Kondo compounds Al3Ce and Al11Ce3  

International Nuclear Information System (INIS)

Neutron diffraction experiments on the Al3Ce and Al11Ce3 compounds have been performed on the multidetector of the I.L.L. high flux reactor. No magnetic structure has been detected on the Al3Ce compound down to 20 mK. This confirms the non magnetic ground state of Al3Ce. For Al11Ce3, two magnetic structures have been observed: a ferromagnetic one at 4.2 K and an antiferromagnetic one at 2 K. The antiferromagnetic structure, which corresponds to a propagation vector (0,0,1/3), implies a strong reduction of the magnetic moment of determined sites; this reflects the Kondo character of the compounds

368

Structural and local electrical properties of AlInN/AlN/GaN heterostructures  

Energy Technology Data Exchange (ETDEWEB)

GaN layers and Al{sub 1-x}In{sub x}N/AlN/GaN heterostructures have been studied by scanning probe microscopy methods. Threading dislocations (TDs), originating from the GaN (0 0 0 1) layer grown on sapphire, have been investigated. Using Current-Atomic Force Microscopy (C-AFM) TDs have been found to be highly conductive in both GaN and AlInN, while using semi-contact AFM (phase-imaging mode) indium segregation has been traced at TDs in AlInN/AlN/GaN heterostructures. It has been assessed that In segregation is responsible for high conductivity at dislocations in the examined heterostructures.

Minj, A.; Cavalcoli, D. [Dipartimento di Fisica, Universita di Bologna, Viale Berti Pichat 6/2, 40127 Bologna (Italy); Cavallini, A., E-mail: anna.cavallini@unibo.it [Dipartimento di Fisica, Universita di Bologna, Viale Berti Pichat 6/2, 40127 Bologna (Italy)

2012-08-01

369

Structural and local electrical properties of AlInN/AlN/GaN heterostructures  

International Nuclear Information System (INIS)

GaN layers and Al1-xInxN/AlN/GaN heterostructures have been studied by scanning probe microscopy methods. Threading dislocations (TDs), originating from the GaN (0 0 0 1) layer grown on sapphire, have been investigated. Using Current-Atomic Force Microscopy (C-AFM) TDs have been found to be highly conductive in both GaN and AlInN, while using semi-contact AFM (phase-imaging mode) indium segregation has been traced at TDs in AlInN/AlN/GaN heterostructures. It has been assessed that In segregation is responsible for high conductivity at dislocations in the examined heterostructures.

370

An impedance study of complex Al/Cu-Al2O3 electrode  

Science.gov (United States)

Electrochemical impedance spectroscopy (EIS) was used to investigate different Cu deposition regimes on Al surface obtained by internal electrolysis and to characterize properties of fabricated electrodes. EIS experimental data confirmed that Cu deposition by internal electrolysis is realized and the complex electrode system is obtained. The main difficulty in preparation of Al/Cu electrodes is to prevent aluminium oxidation before and during electrochemical deposition of Cu particles. In this work NaCl, CH3COONa, K2SO4, mono- and diammonium citrate electrolytes were examined to determine their suitability for impedance measurements. Al/Cu-Al2O3 electrode composition was approved by equivalent circuit analysis, optical and scanning electron microscope methods. The most optimal Cu deposition mode using internal electrolysis was determined. The obtained results are promising for future electrochemical fabrication of nanostructures directly on Al surfaces by internal electrolysis.

Denisova, J.; Katkevics, J.; Erts, D.; Viksna, A.

2011-06-01

371

Different magnetic behaviour of the Kondo compounds Al3Ce and Al11Ce3  

International Nuclear Information System (INIS)

Neutron diffraction experiments on the Al3Ce and Al11Ce3 compounds have been performed on the multidetector of the ILL high flux reactor. No magnetic structure has been detected on the Al3Ce compound down to 20 m K. This confirms the non-magnetic ground state of Al3Ce. For Al11Ce3, two magnetic structures have been observed: a ferromagnetic one at 4.2 K and an antiferromagnetic one at 2 K. The antiferromagnetic structure, which corresponds to a propagation vector (0, 0, 1/3), implies a strong reduction of the magnetic moment of determined sites; this reflects the Kondo character of the compounds. (orig.)

372

Formation of gamma'-Ni3Al via the Peritectoid Reaction: gamma plus beta (+Al2O3) equals gamma'(+Al2O3)  

Science.gov (United States)

The activities of Al and Ni were measured using multi-cell Knudsen effusion-cell mass spectrometry (multi-cell KEMS), over the composition range 8 - 32 at.%Al and temperature range T = 1400 - 1750 K in the Ni-Al-O system. These measurements establish that equilibrium solidification of gamma'-Ni3Al-containing alloys occurs by the eutectic reaction, L (+ Al2O3) = gamma + beta (+ Al2O3), at 1640 plus or minus 1 K and a liquid composition of 24.8 plus or minus 0.2 at.%Al (at an unknown oxygen content). The {gamma + beta + Al2O3} phase field is stable over the temperature range 1633 - 1640 K, and gamma'-Ni3Al forms via the peritectiod, gamma + beta (+ Al2O3) = gamma'(+ Al2O3), at 1633 plus or minus 1 K. This behavior is inconsistent with the current Ni-Al phase diagram and a new diagram is proposed. This new Ni-Al phase diagram explains a number of unusual steady state solidification structures reported previously and provides a much simpler reaction scheme in the vicinity of the gamma'-Ni3Al phase field.

Copland, Evan

2008-01-01

373

Formation of gamma(sup prime)-Ni3Al via the Peritectoid Reaction: gamma + beta (+ Al2O3)=gamma(sup prime)(+ Al2O3)  

Science.gov (United States)

The activities of Al and Ni were measured using multi-cell Knudsen effusion-cell mass spectrometry (multi-cell KEMS), over the composition range 8-32 at.%Al and temperature range T=1400-1750 K in the Ni-Al-O system. These measurements establish that equilibrium solidification of gamma(sup prime)-Ni3Al-containing alloys occurs by the eutectic reaction, L (+ Al2O3)=gamma + Beta(+ Al2O3), at 1640 +/- 1 K and a liquid composition of 24.8 +/- 0.2 at.%al (at an unknown oxygen content). The {gamma + Beta (+Al2O3} phase field is stable over the temperature range 1633-1640 K, and gamma(sup prime)-Ni3Al forms via the peritectoid, gamma + Beta (+ Al2O3)=gamma(sup prime) (+ Al2O3), at 1633 +/- 1 K. This behavior is consistent with the current Ni-Al phase diagram and a new diagram is proposed. This new Ni-Al phase diagram explains a number of unusual steady-state solidification structures reported previously and provides a much simpler reaction scheme in the vicinity of the gamma(sup prime)-Ni2Al phase field.

Copeland, Evan

2008-01-01

374

Microstructural defects modeling in the Al-Mo system  

International Nuclear Information System (INIS)

In this work we have utilized computer simulation techniques to study microstructural defects, such as point defects and interfaces, in the Al-Mo alloy. Such alloy is taken as a model to study the Al(fcc)/U-Mo(bcc) interface. The EAM interatomic potential used has been fitted to the formation energy and lattice constant of the AlMo3 intermetallic. Formation of vacancies for both components Al and Mo and anti-sites, AlMo and MoAl, as well as vacancy migration was studied in this structure. We found that the lowest energy defect complex that preserves stoichiometry is the antisite pair AlMo+MoAl, in correspondence with other intermetallics of the same structure. Our results also suggest that the structure of the Al(fcc)/Mo(bcc) interface is unstable, while that of the Al(fcc)/Al5Mo interface is stable, as observed experimentally. (author)

375

Retention of chromium by modified Al-Bentonite Retenção de cromo por Al-bentonita modificada  

Directory of Open Access Journals (Sweden)

Full Text Available Retention of chromium (III from a tanning wastewater by modified Al-bentonites was studied. One bentonite from San Juan province, Argentina, was used. Al-bentonite was prepared by contact of bentonite with hydrolyzed OH-Al solutions (0.10 M in Al for 24 hours. The modified Al-bentonites were obtained by: a treatment with 0.5 M sodium chloride; b with 0.5 M sodium chloride adjusted at pH 8; and c treatment with an hexametaphosphate solution after sodium addition. Then, the samples were dried at 100 °C and heated at 500 °C. The chromium (III retention by samples was carried out in batch system putting in contact the material with a 2000 ppm Cr tannery waste at different times. The retained chromium was characterized by analyzing the supernatant using UV-visible spectroscopy. The different chromium retention was correlated with structural characteristics of the solids.Foi estudada a retenção de cromo (III de águas residuais por meio de Al-bentonitas modificadas. Foi usada uma bentonita da província de San Juan, Argentina. As bentonitas-Al forma preparadas colocando-as em contato com soluções (0,10 M Al hydrolizadas de OH-Al durante 24 horas. As bentonitas-Al modidicadas foram obtidas por meio de: a tratamento com cloreto de sódio 0,5 M; b com cloreto de sódio 0,5 M sodium com pH ajustado para 8; e c tratamento com uma solução de hexametafosfato após a adição de sódio. As amostras foram então secas a 100 °C e aquecidas a 500 °C. A retenção do cromo (III pelas amostras foi feita em lotes colocando o material em contato em diferentes tempos com um resíduo contendo 2000 ppm de cromo. O cromo retido foi caracterizado por meio de análise do sobrenadante usando espectroscopia UV-visível. As diferentes retenções de cromo foram correlacionadas com características estruturais dos sólidos.

C. Volzone

2002-09-01

376

Wear characteristics of Al-AlN composites produced in-situ by nitrogenation  

Science.gov (United States)

In the present scenario most of the parts used in automobile and aerospace industries are made of composites. Aluminium metal has a very high strength to weight ratio. Al-AlN metal matrix composites have excellent mechanical properties like good wear resistance, high hardness and high strength to weight ratio which are obtained from low density of aluminium and high hardness and wear resistance of AlN. Therefore, use of Al-AlN MMC leads to advantages in automobile industries as it reduces fuel consumption and gives better structural strength. The composites can be produced ex-situ by introducing AlN as reinforcement into the metal matrix and in- situ by nitrogenation process. In the present process Al-AlN composites were fabricated by treating molten aluminium with a mixture of CaO and NH4Cl and held at temperature range at 750-930°C and then cast into a metal mould. Addition of CaO to NH4Cl is found to have a more pronounced effect as a nitrogenation agent in comparison with NH4Cl in the molten aluminium in the temperature range of 700- 1000°C. Castings of aluminium and Al-AlN composites were prepared by mixing different ratios of aluminium and NH4Cl, at different casting temperatures and holding time. Wear resistance and hardness of the samples were determined, and microstructure studies were carried out. The composite formed using higher amount of NH4Cl had higher hardness and wear resistance.

Pradhan, S.; Jena, S. K.; Patnaik, S. C.; Swain, P. K.; Majhi, J.

2015-02-01

377

AuAl{sub 2} and PtAl{sub 2} as potential plasmonic materials  

Energy Technology Data Exchange (ETDEWEB)

Highlights: •The electronic structure dielectric functions of PtAl{sub 2}, AuAl{sub 2} and intermediate alloys were calculated. •The experimental reflectivity and EELS for PtAl{sub 2} showed good agreement with the theoretical spectra. •The yellow color of PtAl{sub 2} is associated with a bulk plasmon at 3 eV. •These materials are good candidates for applications in plasmonics. -- Abstract: The dielectric functions of PtAl{sub 2}, AuAl{sub 2} and hypothetical intermediate alloys of the two in the form of Au{sub x}Pt{sub 1?x}Al{sub 2} were calculated from first principles using density functional theory (DFT) and the random phase approximation (RPA). From these, the reflectivity, electron energy-loss spectra (EELS) and small sphere extinction spectra are predicted. The experimental reflectivity and EELS were measured for PtAl{sub 2} and showed good agreement with the theoretical spectra. The yellow color of PtAl{sub 2} is associated with a bulk plasmon at 3 eV. We predict that the optical properties of hypothetical intermediate alloys would show a smooth evolution with composition. The details of this change can be understood by examination of the underlying density of states (DOS). The predicted small sphere extinction spectra and quality factors show a strong surface plasmon resonance for these materials, with PtAl{sub 2} having the optimum performance. The results indicate that these materials are good candidates for applications in plasmonics.

Keast, V.J., E-mail: vicki.keast@newcastle.edu.au [School of Mathematical and Physical Sciences, The University of Newcastle, Callaghan, NSW 2308 (Australia); Zwan, B. [School of Mathematical and Physical Sciences, The University of Newcastle, Callaghan, NSW 2308 (Australia); Supansomboon, S.; Cortie, M.B. [Institute for Nanotechnology, University of Technology, Sydney, NSW 2007 (Australia); Persson, P.O.Å. [Thin Film Physics Division, Department of Physics, Chemistry, and Biology (IFM), Linköping University, SE-581 83 Linköping (Sweden)

2013-11-15

378

Management of respiratory symptoms in ALS.  

LENUS (Irish Health Repository)

Respiratory insufficiency is a frequent feature of ALS and is present in almost all cases at some stage of the illness. It is the commonest cause of death in ALS. FVC is used as important endpoint in many clinical trials, and in decision-making events for patients with ALS, although there are limitations to its predictive utility. There are multiple causes of respiratory muscle failure, all of which act to produce a progressive decline in pulmonary function. Diaphragmatic fatigue and weakness, coupled with respiratory muscle weakness, lead to reduced lung compliance and atelectasis. Increased secretions increase the risk of aspiration pneumonia, which further compromises respiratory function. Bulbar dysfunction can lead to nutritional deficiency, which in turn increases the fatigue of respiratory muscles. Early recognition of respiratory decline and symptomatic intervention, including non-invasive ventilation can significantly enhance both quality of life and life expectancy in ALS. Patients with respiratory failure should be advised to consider an advance directive to avoid emergency mechanical ventilation.

Hardiman, Orla

2012-02-01

379

Management of respiratory symptoms in ALS.  

LENUS (Irish Health Repository)

Respiratory insufficiency is a frequent feature of ALS and is present in almost all cases at some stage of the illness. It is the commonest cause of death in ALS. FVC is used as important endpoint in many clinical trials, and in decision-making events for patients with ALS, although there are limitations to its predictive utility. There are multiple causes of respiratory muscle failure, all of which act to produce a progressive decline in pulmonary function. Diaphragmatic fatigue and weakness, coupled with respiratory muscle weakness, lead to reduced lung compliance and atelectasis. Increased secretions increase the risk of aspiration pneumonia, which further compromises respiratory function. Bulbar dysfunction can lead to nutritional deficiency, which in turn increases the fatigue of respiratory muscles. Early recognition of respiratory decline and symptomatic intervention, including non-invasive ventilation can significantly enhance both quality of life and life expectancy in ALS. Patients with respiratory failure should be advised to consider an advance directive to avoid emergency mechanical ventilation.

Hardiman, Orla

2011-03-01

380

Kinematics of Disease Progression in Bulbar ALS  

Science.gov (United States)

The goal of this study was to investigate the deterioration of lip and jaw movements during speech longitudinally in three individuals diagnosed with bulbar amyotrophic lateral sclerosis (ALS). The study was motivated by the need to understand the relationship between physiologic changes in speech movements and clinical measures of speech…

Yunusova, Yana; Green, Jordan R.; Lindstrom, Mary J.; Ball, Laura J.; Pattee, Gary L.; Zinman, Lorne

2010-01-01

381

U-ALS: A Ubiquitous Learning Environment  

Science.gov (United States)

The diffusion of the use of the learning virtual environments presents a great potential for the development of an application which meet the necessities in the education area. In view of the importance of a more dynamic application and that can adapt itself continuously to the students' necessities, the "U-ALS" (Ubiquitous Adapted Learning…

Piovesan, Sandra Dutra; Passerino, Liliana Maria; Medina, Roseclea Duarte

2012-01-01

382

Al/Cl2 molten salt battery  

Science.gov (United States)

Molten salt battery has been developed with theoretical energy density of 5.2 j/kg (650 W-h/lb). Battery, which operates at 150 C, can be used in primary mode or as rechargeable battery. Battery has aluminum anode and chlorine cathode. Electrolyte is mixture of AlCl3, NaCl, and some alkali metal halide such as KCl.

Giner, J.

1972-01-01

383

Al-Ghazali on Moral Education  

Science.gov (United States)

Al-Ghazali (1058-1111 CE) is probably the most influential scholar, philosopher, theologian, legal expert, religious reformer and mystic in the history of Islam. Although he wrote extensively about education, and particularly about moral education, this writing is scattered through a number of different works and has received less scholarly…

Alavi, Hamid Reza

2007-01-01

384

The Science of al-Biruni  

OpenAIRE

Al-Biruni (973-1048) was one of the greatest scientists of all times. He was an astronomer, mathematician and philosopher, and studied physics and natural sciences. In this paper, we will discuss some of his experimental methods and some instruments he used.

Sparavigna, Amelia Carolina

2013-01-01

385

Joint SSRTNet/ALS-MES Workshop report  

International Nuclear Information System (INIS)

This joint workshop brought together experimentalists and theorists interested in synchrotron radiation and highlighted subjects relevant to molecular environmental science (MES). The strong mutual interest between the participants resulted in joint sessions on the first day, followed by more specialized parallel sessions on the second day. Held in conjunction with the Advanced Light Source (ALS) Users' Association Annual Meeting at the Lawrence Berkeley National Laboratory (Berkeley Lab), the Synchrotron Radiation Research Theory Network (SRRTNet) workshop was co-organized by Michel Van Hove (Berkeley Lab and University of California, Davis) and Andrew Canning (Berkeley Lab), while David Shuh (Berkeley Lab) organized the ALS-MES workshop. SRRTNet is a global network that promotes the interaction of theory and experiment (http://www.cse.clrc.ac.uk/Activity/SRRTnet). The ALS-MES project is constructing Beamline 11.0.2.1-2, a new soft x-ray beamline for MES investigations at photon energies from 75 eV to 2 keV, to provide photons for wet spectroscopy end stations and an upgraded scanning transmission x-ray microscope (STXM). The ALS-MES beamline and end stations will be available for users in the late fall of 2002

386

Quasiparticle relaxation times in clean Al films  

International Nuclear Information System (INIS)

Double tunnel junctions S1-S2-S3 (Al-Al-Pb:Bi, mounted on sapphire substrates in vacuum) have been used to measure the inelastic (tau/sub i/) and elastic (tau/sub e/) scattering times in the center Al film (T/sub c/=1.28 K). The current peak at V/sub d/1= +- (Vertical BarV/sub g/Vertical Bar+(?1-?3)/e) and the current step at V/sub d/2= +- (Vertical BarV/sub g/Vertical Bar-(?1+?3)/e) provide complementary data on tau/sub i/(E,T*) and tau/sub e/(E,T*) in S2 over the energy range 1.5?(0)1 which through the BCS gap equation yields T(1. We assume T(1=T(2=T* and T3=T/sub s/ the substrate temperature which is measured directly. The measured generator junction power per unit area P/sub g/, T*, and T/sub s/ yield P/sub g/=11(T/sup asterisk4/-T/sup asterisk4//sub s/) mW cm-2, in good agreement with the calculations by Kaplan for an Al-sapphire interface. A fit of our data for tau/sub i/ with theory gives a value of (1.0 +- 0.14) x 10-7 sec for tau0, the characteristic electric-phonon scattering time

387

Synthesis of Ti-Al porous perform  

Directory of Open Access Journals (Sweden)

Full Text Available Purpose: Article describes production method of intermetallic porous perform for reinforcing of composite materials. Usefulness of the high temperature self-propagating synthesis (SHS, with appropriate modification, to produce perform for production of composite was evaluated.Design/methodology/approach: Mixture of aluminum and titanium powder was cold isostatically pressed (CIPed and produced cylindrical pill was ignited in microwave field. Obtained structure usually have open porosity what enables for pressure infiltration with molten metal. The investigations of the structure of preforms on the scanning electron microscope (SEM were made.Findings: The produced performs in most cases reveal open porosity, uniform morphology and are suitable for infiltration process. After reaction Al-Ti compounds form partly globular structure with microhardness much higher than substratesResearch limitations/implications: In the actual stages of this work proposed method can be used for manufacturing of porous performs, which mainly contain Al3Ti. During reaction, mixture compacts with the molar ratio of Al/Ti=1 were transformed into inhomogeneous structure.Practical implications: Obtained perform can be widely used as the reinforcement to produce hybrid composite materials by the infiltration method. Aluminum casting alloys can be locally reinforced to improve hardness and resistance to oxidization at high temperature.Originality/value: Article is valuable for persons engaged in production of casting composite materials reinforced with porous perform. Proposed method allows to incorporate hard structures from Al-Ti compounds into aluminum casting.

K. Naplocha

2008-02-01

388

Electrochemical formation of Al-Tm intermetallics in eutectic LiCl-KCl melt containing Tm and Al ions  

Science.gov (United States)

This work focuses on investigating the electrochemical formation of Al-Tm and Al-Li-Tm alloys in LiCl-KCl-AlCl3-Tm2O3 melt on both W and Al electrodes. Thermodynamic calculation and electrochemical behavior of LiCl-KCl melt containing both AlCl3 and Tm2O3 showed that AlCl3 can chlorinate Tm2O3 to release Tm(III) ions. Three kinds of Al-Tm intermetallics at about -1.26, -1.32 and -1.43 V were detected by means of various electrochemical measurement techniques, i.e. cyclic voltammetry, square wave voltammetry and open circuit chronopotentiometry. Potentiostatic and galvanostatic electrolysis were carried out on Al and W electrodes to prepare Al-Tm and Al-Li-Tm alloys, respectively. The composition of Al-Li-Tm alloys was analyzed by inductive coupled plasma atomic emission spectrometer (ICP-AES).

Li, Xing; Yan, Yong-De; Zhang, Mi-Lin; Tang, Hao; Ji, De-Bin; Han, Wei; Xue, Yun; Zhang, Zhi-Jian

2014-09-01

389

ELECTROLYSIS OF SWINE MANURE EFFLUENTS USING THREE DIFFERENT ELECTRODES Fe-Fe, Al-Al AND Fe-Al  

Directory of Open Access Journals (Sweden)

Full Text Available Swine effluent with high organic strength need to be treated to make it suitable for applying to crop/pasture fields, or discharging to any waterways. Electrocoagulation is a relatively simpler and cheaper technique over biological and chemical treatment methods currently used to treat high-strength industrial and municipal wastewater. The performance of an electrocoagulation system mainly depends on the pH, Electrical Conductivity (EC of the medium, Chemical Oxygen Demand (COD loading rates and catalytic activity of the electrodes used. In this research, a study was conducted to compare the pollutant removal efficiencies of three electrodes (Fe-Fe, Al-Al and Fe-Al with three electric current levels (500, 1000 and 2000 mA while treating swine manure effluents. The electrochemical cell consisted of two parallel rectangular plates (90×25×1.5 mm of Iron (Fe-Fe, Aluminum (Al-Al and Iron-Aluminum (Fe-Al, later on described as hybrid electrodes; immersed in a beaker with 550 mL swine effluents and powered by a Direct Current (DC supply. All studies were conducted in batches at room temperature. In general, removal efficiencies were increased with increasing current densities and electrolysis times for electrodes evaluated. Aluminum electrodes outperformed iron and hybrid (iron-aluminum electrodes in removing Total Phosphorus (TP at all current density levels tested. Overall, use of hybrid electrodes resulted in better COD removal. For the same treatment times (1200 s at higher current density (21 mA cm-2, hybrid electrodes removed about 100% COD, which are about 1.9 and 1.3 times higher than those of aluminum and iron electrodes, respectively. Iron electrodes showed the highest removal efficiency (85% for Total Organic Carbon (TOC at 21 mA cm-2 current density and 1200 s treatment time. Overall, lower Specific Electrical Energy Consumptions (SEECs per kg of Pollutants (TP, COD and TOC were estimated for the aluminum electrodes than the other electrodes combination.

S. Rahman

2014-01-01

390

Al-Batin Alluvial Fan, Southern Iraq  

Directory of Open Access Journals (Sweden)

Full Text Available Al-Batin alluvial fan is one of the largest alluvial fans in Iraq, especially in the Iraqi Southern Desert. Its eastern and southern limits form parts of the Iraqi-Kuwait international borders. The fan is deposited by Wadi Al-Batin, the last apex being on the southern limits of the main wide depression formed by the active Abu Jir-Euphrates Fault Zone. The main trend of the fan is almost SW-NE. The length and the maximum width of the fan are 110.192 Km and 119.1 Km, respectively, whereas the slope along its length is 0.7°. The fan is covered by gypcrete sheet with thickness varying from (0.5 - 1.5 m. Four stages were recognized within the fan, which is dated to be Pleistocene in age. The four stages are marked by clear height differences. The deposition of the alluvial fan is highly affected by the activity of the active Abu Jir-Euphrates Fault Zone, which is represented on the surface as a wide shallow depression in which the fan is laid down by Wadi Al-Batin. The continuous deposition of the fan has affected the course of the Euphrates Formation within Hammar Marsh and also the course of Khor Al-Zubair in its upper reaches south of Al-Qurna, where the Euphrates and Tigris rivers merge together. Also there is a trace of ancient distributary of the Euphrates River that was flowing directly to the Arabian Gulf, through an estuary, which is abandoned and does not exist anymore.

Varoujan K. Sissakian

2014-10-01

391

Influence of Schottky drain contacts on the strained AlGaN barrier layer of AlGaN/AlN/GaN heterostructure field-effect transistors  

International Nuclear Information System (INIS)

Rectangular Schottky drain AlGaN/AlN/GaN heterostructure field-effect transistors (HFETs) with different gate contact areas and conventional AlGaN/AlN/GaN HFETs as control were both fabricated with same size. It was found there is a significant difference between Schottky drain AlGaN/AlN/GaN HFETs and the control group both in drain series resistance and in two-dimensional electron gas (2DEG) electron mobility in the gate—drain channel. We attribute this to the different influence of Ohmic drain contacts and Schottky drain contacts on the strained AlGaN barrier layer. For conventional AlGaN/AlN/GaN HFETs, annealing drain Ohmic contacts gives rise to a strain variation in the AlGaN barrier layer between the gate contacts and the drain contacts, and results in strong polarization Coulomb field scattering in this region. In Schottky drain AlGaN/AlN/GaN HFETs, the strain in the AlGaN barrier layer is distributed more regularly. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

392

Reactive milling synthesis of nanocrystalline Al-Cu/Al{sub 2}O{sub 3} nanocomposite  

Energy Technology Data Exchange (ETDEWEB)

Nanocrystalline Al-4 wt% Cu alloy reinforced with nanometric Al{sub 2}O{sub 3} particles was synthesized by in situ reactive milling of Al and CuO powder mixture. X-ray diffraction (XRD), differential thermal analysis (DTA) and transmission electron microscopy (TEM) techniques were employed to study the mechanically induced solid state reaction between the blended powders. The mechanical milling stages were studied by scanning electron microscopy (SEM), bulk density measurement and laser particle size analyzer. It was shown that the reaction between Al and CuO occurs progressively as the mechanical milling continues, leading to formation of nanoscaled alumina particles. The grain refinement of the matrix by severe plastic deformation also resulted in the formation of nanocrystalline Al-Cu alloy. It was determined that the FCC Al (Cu) solid solution has a lattice parameter of 4.04 A, average crystallite size of about 50 nm and lattice strain of 0.35%. The size of alumina particles was in the range of 10-50 nm and they were mostly distributed at the grain boundaries. The processed nanocomposite powder has fine and equiaxed particles with relatively high bulk density. This paper presents structural evolution and morphological changes occurring during attrition milling of Al-CuO powder mixture.

Arami, H. [Department of Materials Science and Engineering and Institute for Nanoscience and Nanotechnology, Sharif University of Technology, P.O. Box 11365-9466, Azadi Avenue, Tehran (Iran, Islamic Republic of); Simchi, A. [Department of Materials Science and Engineering and Institute for Nanoscience and Nanotechnology, Sharif University of Technology, P.O. Box 11365-9466, Azadi Avenue, Tehran (Iran, Islamic Republic of)], E-mail: simchi@sharif.edu

2007-08-25

393

Reactive milling synthesis of nanocrystalline Al-Cu/Al2O3 nanocomposite  

International Nuclear Information System (INIS)

Nanocrystalline Al-4 wt% Cu alloy reinforced with nanometric Al2O3 particles was synthesized by in situ reactive milling of Al and CuO powder mixture. X-ray diffraction (XRD), differential thermal analysis (DTA) and transmission electron microscopy (TEM) techniques were employed to study the mechanically induced solid state reaction between the blended powders. The mechanical milling stages were studied by scanning electron microscopy (SEM), bulk density measurement and laser particle size analyzer. It was shown that the reaction between Al and CuO occurs progressively as the mechanical milling continues, leading to formation of nanoscaled alumina particles. The grain refinement of the matrix by severe plastic deformation also resulted in the formation of nanocrystalline Al-Cu alloy. It was determined that the FCC Al (Cu) solid solution has a lattice parameter of 4.04 A, average crystallite size of about 50 nm and lattice strain of 0.35%. The size of alumina particles was in the range of 10-50 nm and they were mostly distributed at the grain boundaries. The processed nanocomposite powder has fine and equiaxed particles with relatively high bulk density. This paper presents structural evolution and morphological changes occurring during attrition milling of Al-CuO powder mixture

394

High-performance nonvolatile Al/AlOx/CdTe:Sb nanowire memory device  

International Nuclear Information System (INIS)

Here we demonstrate a room temperature processed nonvolatile memory device based on an Al/AlOx/CdTe:Sb nanowire (NW) heterojunction. Electrical analysis shows an echelon hysteresis composed of a high-resistance state (HRS) and a low-resistance state (LRS), which can allow it to write and erase data from the device. The conductance ratio is as high as 106, with a retention time of 3 × 104 s. Moreover, the SET voltages ranged from +6 to +8 V, whilst the RESET voltage ?0 V. In addition, flexible memory nano-devices on PET substrate with comparable switching performance at bending condition were fabricated. XPS analysis of the Al/AlOx/CdTe:Sb NW heterojunction after controlled Ar+ bombardment reveals that this memory behavior is associated with the presence of ultra-thin AlOx film. This Al/AlOx/CdTe:Sb NW heterojunction will open up opportunities for new memory devices with different configurations. (paper)

395

Neutronic comparison of the nuclear fuels U3Si2/Al and U-Mo/Al  

International Nuclear Information System (INIS)

The search for materials that allow the fabrication of nuclear fuels with higher uranium densities comes from the mid 50s. Today, a high density and low enriched nuclear fuel based on ?-UMo alloys is the most promising fuel to replace the U3Si2/Al dispersion fuel used worldwide in research and material test reactors. Alloys of uranium-molybdenum are prepared with 6 to 10% Mo addition and can be manufactured as dispersion or monolithic fuels. The aim of this paper is to compare the infinite multiplication factor (K?), obtained through neutronic calculation with the code Scale 6, for aluminum coated plates reflected in all directions containing U3Si2/Al and U-Mo/Al dispersion fuels. The U3Si2/Al dispersion fuel used in the calculation has an uranium density of 4 gU/cm3 and the U-Mo-Al dispersion fuels have densities ranging from 4 to 7.52 gU/cm3 and 7 and 10% Mo addition. The results show that the K? calculated for U-Mo/Al fuels is lower than that for U3Si2/Al fuel and increases between the uranium densities of 4 and 5 gU/cm3 and decreases for higher uranium densities. (author)

396

Probing the role of calmodulin in Al toxicity in maize.  

Science.gov (United States)

The role of calmodulin on Al toxicity was studied in two maize (Zea mays L.) inbred lines, Cat 100-6 (Al-tolerant) and S 1587-17 (Al-sensitive). Increasing levels of Al induced the release of malate at similar rate by roots of both genotypes, while the exudation of citrate, a stronger Al-binding compound, was 3.5 times higher in Cat 100-6 seedlings exposed to 16.2x10(-6) Al(3+) activity. The calmodulin inhibitor trifluoperazine significantly reduced the root growth in both genotypes, mimicking the main effect of Al. However, when Cat 100-6 and S 1587-17 seedlings were challenged with Al in conjunction with trifluoperazine, no further reduction in root growth or any other effect of Al toxicity was observed. The rate of Al-induced citrate exudation by both genotypes was not affected by treatment with trifluoperazine or calmidazolium, another calmodulin inhibitor. The Al(3+) interaction with cytoplasmic CaM was estimated using models for the binding of Al(3+) and Mg(2+) with CaM and physiological concentrations of citrate, CaM, InsP(3), ATP, ADP, Al(3+) and Mg(2+). In this simulation, Al(3+) associated with citrate and InsP(3), but not with CaM. We conclude that calmodulin is not relevant to the physiological processes leading to the Al tolerance in maize, nor is it a primary target for Al toxicity. PMID:11557073

Jorge, R A; Menossi, M; Arruda, P

2001-10-01

397

Calculation of Gibbs energy of Zr-Al-Ni, Zr-Al-Cu, Al-Ni-Cu and Zr-Al-Ni-Cu liquid alloys based on quasiregular solution model  

Energy Technology Data Exchange (ETDEWEB)

With the effects of electronic structure and atomic size being introduced, the mixing enthalpy as well as the Gibbs energy of the ternary Zr-Al-Cu, Ni-Al-Cu, Zr-Ni-Al and quaternary Zr-Al-Ni-Cu systems are calculated based on quasiregular solution model. The computed results agree well with the experimental data. The sequence of Gibbs energies of different systems is: G {sub Zr-Al-Ni-Cu} < G {sub Zr-Al-Ni} < G {sub Zr-Al-Cu} < G {sub Cu-Al-Ni}. To Zr-Al-Cu, Ni-Al-Cu and Zr-Ni-Al, the lowest Gibbs energy locates in the composition range of X {sub Zr} 0.39-0.61, X {sub Al} = 0.38-0.61; X {sub Ni} = 0.39-0.61, X {sub Al} = 0.38-0.60 and X {sub Zr} = 0.32-0.67, X {sub Al} = 0.32-0.66, respectively. And to the Zr-Ni-Al-Cu system with 66.67% Zr, the lowest Gibbs energy is obtained in the region of X {sub Al} = 0.63-0.80, X {sub Ni} = 0.14-0.24.

Li, H.Q. [Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Yang, Y.S. [Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China)]. E-mail: ysyang@imr.ac.cn; Tong, W.H. [Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Wang, Z.Y. [Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China)

2007-01-31

398

Calculation of Gibbs energy of Zr-Al-Ni, Zr-Al-Cu, Al-Ni-Cu and Zr-Al-Ni-Cu liquid alloys based on quasiregular solution model  

International Nuclear Information System (INIS)

With the effects of electronic structure and atomic size being introduced, the mixing enthalpy as well as the Gibbs energy of the ternary Zr-Al-Cu, Ni-Al-Cu, Zr-Ni-Al and quaternary Zr-Al-Ni-Cu systems are calculated based on quasiregular solution model. The computed results agree well with the experimental data. The sequence of Gibbs energies of different systems is: G Zr-Al-Ni-Cu Zr-Al-Ni Zr-Al-Cu Cu-Al-Ni. To Zr-Al-Cu, Ni-Al-Cu and Zr-Ni-Al, the lowest Gibbs energy locates in the composition range of X Zr 0.39-0.61, X Al = 0.38-0.61; X Ni = 0.39-0.61, X Al = 0.38-0.60 and X Zr = 0.32-0.67, X Al = 0.32-0.66, respectively. And to the Zr-Ni-Al-Cu system with 66.67% Zr, the lowest Gibbs energy is obtained in the region of X Al = 0.63-0.80, X Ni = 0.14-0.24

399

Influence of loading on wear of composite material FeAl-Al2O3  

Directory of Open Access Journals (Sweden)

Full Text Available In the paper, the authors showed the results of studies on influence of production conditions on composite material properties during intermetalic phase Fe-Al reinforced by Al2O3 particles. It was assessed that the quantity, size and condition of the surface of applied reinforcement has a significant influence on properties of composite material. Improvement of tribologic properties and resistance to erosion wear of the material was noted together with decrease in size of the particles used as reinforcement of the composite material. The use of Al2O3 particles covered with nickel layer as reinforcement substantially improved properties of studied composite material.

A. Patejuk

2007-04-01

400

Structure of 26Al studied by one - nucleon transfer reaction 27Al(d,t  

Directory of Open Access Journals (Sweden)

Full Text Available The excited states of 26Al have been produced and studied using 27Al(d,t reaction with 25 MeV deuteron as projectile. Optical model potential parameters were extracted from the measured elastic scattering angular distribution. Zero range distorted wave Born approximation analysis for the ground and 0.223 MeV states of 26Al have been done. The spectroscopic factors calculated for these states are found to be in good agreement with the previously reported values.

Srivastava Vishal

2015-01-01

401

Assessment of coronary heart diseases in diabetics in al-Madinah al-Munawarah  

OpenAIRE

Omar al-Nozha1, Moaz Mojadadi2, Mohamed Mosaad1,3, Mohamed F El-Bab2,41Department of Medicine, 2Department of Physiology, College of Medicine, Taibah University, al-Madinah al-Munawarah, Kingdom of Saudi Arabia; 3Department of Medicine, 4Department of Physiology, Faculty of Medicine, Suez Canal University, Ismailia, EgyptBackground: Coronary heart disease is highly prevalent and a major cause of morbidity and mortality in diabetic patients. The aim of this study was to assess the major risk f...

al-Nozha O; Mojadadi M; Mosaad M; Mf, El-bab

2012-01-01

402

Adherent Al2O3 scales formed on undoped NiCrAl alloys  

Science.gov (United States)

Changes in the spalling behavior of Al2O3 scales formed on an undoped NiCrAl alloy are described. Two samples of Ni-15Cr-13Al (wt pct), one a control and the other sanded, were subjected to 25 oxidation cycles. It is observed that adherent scales formed on the sanded sample; however, the control sample had speckled, spalled scales. The data reveal that the adherent scales are caused by repeated removal of surface layers after each oxidation cycle. It is determined that interfacial segregation of sulfur influences spallation and sulfur removal increases bonding. The effect of moisture on scale adhesions is investigated.

Smialek, James L.

1987-01-01

403

DX centers in AlAs and GaAs-AlAs selectively doped superlattices  

OpenAIRE

DX centers have been investigated using deep level transient spectroscopy (DLTS) in Si doped AlAs and in selectively doped GaAs-AlAs superlattices (SLs) grown by molecular beam epitaxy. The activation energy for thermal emission is Ea = 0.42 eV in both the SLs and AlAs layers. For the first time a study of the capture in a SL reveals a capture activation energy Ecap = 0.36 cV, which locates the DX at Et?60 meV below the conduction miniband. Taking into account the measured energies and t...

Ababou, S.; Marchand, J.; Mayet, L.; Guillot, G.; Mollot, F.

1991-01-01

404

Ab-initio total energy calculations of cleavage decohesion and shear processes in NiAl, FeAl and ?-TiAl ordered alloys  

Science.gov (United States)

The fracture and deformaton behaviour of ordered NiAl, FeAl and ?-TiAl were studied on the basis of FLMTO total energy calculations of the ?-surface and cleavage decohesion. For the first time, based on ab-initio calculations of generalized stacking fault (gsf) energetics , the structure of the dislocation core was constructed in the scope of the Peierls-Nabarro model with generalized restoring force law. Estimates of the Peierls stress show the correct preferred slip systems for NiAl (100) and for FeAl (110) with the latter prefered mainly because of its low APB energy. In addition, the peculiarities of the ?-surface also make important contributions to dislocation core formation. Differences of the shear and cleavage decohesion of ?-TiAl from ordered B2 NiAl and FeAl will be discussed.

Medvedeva, N. I.; Gornostyrev, Yu. N.; Mryasov, O. N.; Novikov, D. L.; Freeman, A. J.

1996-03-01

405

Valence subband coupling effect on polarization of spontaneous emissions from Al-rich AlGaN/AlN quantum wells.  

Science.gov (United States)

The optical polarization properties of Al-rich AlGaN/AlN quantum wells (QWs) were investigated using the theoretical model based on the k·p method. Numerical results show that there is valence subband coupling which can influence the peak emission wavelength and emission intensity for TE and TM polarization components from Al-rich AlGaN/AlN QWs. Especially the valence subband coupling could be strong enough when CH1 is close to HH1 and LH1 subbands to modulate the critical Al content switching dominant emissions from TE to TM polarization. It is believed that the valence subband coupling may give important influence on polarization properties of spontaneous emissions and should be considered in designing high efficiency AlGaN-based ultraviolet (UV) LEDs. PMID:23262689

Lu, Huimin; Yu, Tongjun; Yuan, Gangcheng; Jia, Chuanyu; Chen, Genxiang; Zhang, Guoyi

2012-12-01

406

Micro Arc Oxidation of Wire Arc Sprayed Al-Mg6, Al-Si12, Al Coatings on Low Alloyed Steel  

Directory of Open Access Journals (Sweden)

Full Text Available Micro arc oxidation of wire arc sprayed Al-Mg6, Al-Si12 and Pure Al coatings on low carbon steel has been performed. The coatings have been analyzed using optic microscope, scanning electron microscopy, X-ray diffraction and surface roughness tester. At the same time, voltage and current regimes are investigated during the process. Then after MAO process, uniform Al2O3 ceramic coatings have been deposited on surface of Al-Mg6, Al-Si12 and Al coated steel. The ceramic coatings are mainly composed of Al2O3 phase. The compound coatings show high hardness and significant improvement of corrosion resistance property.

Levent Cenk Kumruoglu

2011-07-01

407

Amorphous Al1?xTix, Al1?xVx, and Al1?xFex phases in the hydrogen cycled TiCl3, VCl3 and FeCl3 enhanced NaAlH4 systems  

International Nuclear Information System (INIS)

Highlights: ? Quantification of amorphous Al1?xTMx phases in H cycled TMCln enhanced NaAlH4. ? Composite nano surface morphology between crystalline/amorphous Al1?xTMx: TM = Ti, V. ? All Fe atoms consumed within 1?xFex on NaAlH4 surface. ? Amorphous Al1?xTix is Ti poor, 1?xVx reaches 28 at.% V. - Abstract: The twice hydrogen (H) cycled planetary milled (PM) and cryo milled (CM) NaAlH4 + xTMCl3 (transition metal (TM) = Ti, V, Fe) systems (x > 0.1) have been studied by high resolution synchrotron X-ray diffraction, and high resolution transmission electron microscopy (TEM). Intense primary amorphous (a-) Al1?xTMx halos are evident in diffraction data of PM samples for V and Fe, and in CM samples for Ti, V, and Fe. Weaker primary amorphous Al1?xTix halos are evident in PM samples for Ti. The Ti poor a-Al1?xTix phase observed for NaAlH4 + xTiCl3 (x > 0.1) ranges in composition from a-Al86.5Ti13.5 ? a-Al92Ti8. High resolution TEM studies of the Al1?xVx phases in the H cycled PM NaAlH4 + 0.1VCl3 system demonstrates that a nanoscopic composite morphology can exihology can exist between face centred cubic (fcc) crystalline (c-) Al1?xVx and a-Al1?xVx phases, with the c-Al1?xVx/a-Al1?xVx composite embedded on the NaAlH4 surface. The amorphous Al1?xVx reaches ca. 28 at.% V.

408

Optimization of AlGaN-based spacer layer for InAlN/GaN interfaces  

Energy Technology Data Exchange (ETDEWEB)

AlGaN-based spacer layers for lattice-matched and nearly lattice matched InAlN/GaN interfaces were examined in Al{sub 2}O{sub 3}/InAlN/AlGaN/AlN/GaN structures. An Al{sub 2}O{sub 3} overlayer was deposited to investigate the characteristics under positive bias by capacitance-voltage (C-V) measurement. The C-V characteristic for a sample with an Al{sub 0.38}Ga{sub 0.62}N/AlN double spacer layer indicated unfavorable electron accumulation at the InAlN/AlGaN interface inside the barrier under positive bias. To suppress the unfavorable accumulation, attempts were made to increase the Al molar fraction of the AlGaN layer to reduce the conduction band discontinuity and interface charge at InAlN/AlGaN interface. An Al{sub 0.44}Ga{sub 0.56}N/AlN double spacer layer and an Al{sub 0.44}Ga{sub 0.56}N single spacer layer of almost the same total thickness were investigated. Although both spacer layers result in normal C-V characteristics without the indication of unfavorable electron accumulation, the InAlN layer on a 1.5-nm-thick Al{sub 0.44}Ga{sub 0.56}N single spacer layer exhibited superior surface morphology without deteriorating the mobility of the two-dimensional electron gas despite the absence of the AlN layer. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Akazawa, M.; Hashizume, T. [Research Center for Integrated Quantum Electronics, Hokkaido University, Sapporo (Japan); JST-CREST, Sanbancho, Chiyoda-ku, Tokyo (Japan); Gao, B. [Research Center for Integrated Quantum Electronics, Hokkaido University, Sapporo (Japan); Hiroki, M.; Yamahata, S.; Shigekawa, N. [NTT Photonics Laboratories, NTT Corporation, Atsugi, Kanagawa (Japan)

2012-03-15

409

Alloy inhomogeneity and carrier localization in AlGaN sections and AlGaN/AlN nanodisks in nanowires with 240-350 nm emission  

OpenAIRE

The Al-Ga intermixing at Al(Ga)N/GaN interfaces in nanowires and the chemical inhomogeneity in AlxGa1-xN/AlN nanodisks (NDs) are attributed to the strain relaxation process. This interpretation is supported by the three-dimensional strain distribution calculated by minimizing the elastic energy in the structure. The alloy inhomogeneity increases with Al content, leading to enhanced carrier localization signatures in their optical characteristics i.e. red shift of the emissio...

Himwas, C.; Hertog, M. Den; Dang, Le Si; Monroy, E.; Songmuang, R.

2014-01-01

410

Reactive hot pressing and mechanical properties of TiAl3/Ti3AlC2/Al2O3in situ composite  

International Nuclear Information System (INIS)

Highlights: ? Dense TiAl3/Ti3AlC2/Al2O3 composite is prepared via an in situ reactive/hot pressing method. ? The in situ reactive procedure is investigated in detailed based on thermodynamic analysis and microstructure observation. ? The high temperature compressive property is improved by introducing Ti3AlC2 phase. ? The toughening mechanism of TiAl3/Ti3AlC2/Al2O3 composite is summarized. - Abstract: Dense TiAl3/Ti3AlC2/Al2O3 composite was synthesized from Al, TiO2 and TiC powder mixture at 1250 °C and 50 MPa for 10 min using an in situ reaction/hot-pressing method. The reaction kinetic, microstructure, mechanical properties and toughening mechanism of the fabricated composite were investigated. TiO was found to be the transitional phase, and the reaction path for the Al/TiO2/TiC system was proposed. The composite achieved Vickers Hardness, three-point bending strength and fracture toughness of ?8.4 GPa, ?658.9 MPa and ?7.9 MPa/m1/2, respectively. Analysis of microstructure/crack propagation paths interaction revealed that crack deflection, crack bridging, and pull-out of the Ti3AlC2 particles were the main mechanism responsible for the toughening. The compressive strength of the in situ composite was much higher than that of as-cast TiAl3 and could be maintained even at 1000 °C. This was mainly attributed to the cooperative strengthening introduced by Ti3AlC2 and Al2O3

411

Interfacial thermal stability in BN-coated continuous Al2O3 fiber-reinforced NiAl composites  

International Nuclear Information System (INIS)

The microstructural changes at the interfaces in a NiAl composite reinforced with BN-coated continuous single crystal Al2O3 fibers were studied by analytical electron microscopy and high-resolution electron microscopy (HREM) after annealing at 1000 deg. C for 100 h and 500 h. Both NiAl/BN and BN/Al2O3 interfaces exhibited excellent stability during annealing, as did the AlN layer formed at NiAl/BN interface during processing. In the case of contamination which was introduced through the use of a glue during diffusion bonding of the composite, significant changes of the microstructure at both NiAl/BN and BN/Al2O3 interfaces were observed. A continuous reaction layer formed at the BN/Al2O3 interface during annealing. The reaction product was identified by electron diffraction as Al18B4O33. We propose to attribute this to the reaction: 9Al2O3+2B2O3?Al18B4O33. Many nanoparticles were observed in the BN matrix near the BN(AlN)/NiAl interface in the as-fabricated composite. Neither the AlN layer nor these nanoparticles grew during annealing. HREM images of the precipitates revealed a structure distinctly different from that of the BN matrix. B, C, N and Al were detected in these precipitates by EELS analysis

412

New developments in state-specific multireference coupled-cluster theory  

OpenAIRE

Die Coupled-Cluster-Theorie basierend auf einer Slater-Determinante als Referenz ist eine der erfolgreichsten Ansätze in der Quantenchemie zur Beschreibung von Atomen und Molekülen. Um deren Anwendbarkeit auf Systeme mit entarteten oder quasientarteten Elektronenkonfigurationen zu erweitern, wurden sogenannte Multireferenz-Coupled-Cluster-Ansätze entwickelt, die mehr als eine Referenzdeterminante verwenden. Eine der vielversprechendsten Formulierungen der Multireferenz-Coupled-Cluster-Theo...

Prochnow, Eric

2010-01-01

413

Microstructural and macroscopic aspects of the plasticity of complex metallic alloys  

OpenAIRE

Komplexe intermetallische Phasen (CMAs) stellen eine Materialklasse dar deren Kristallstrukturen auf außergewöhnlich großen Einheitszellen, mit bis zu mehr als eintausend Atomen beruhen. Aufgrund ihrer besonderen strukturellen Merkmale unterscheidet sich das plastische Verformungsverhalten dieser Phasen maßgeblich von konventionellen, aus strukturell einfachen Systemen bekannten Verformungs-mechanismen. In der vorliegenden Arbeit wurde die Plastizität der drei Legierungssysteme µ-Al-Mn ...

Roitsch, Stefan

2008-01-01

414

Growth and characterization of a high-quality Al0.45Ga0.55N layer with AlGaN/AlN superlattices  

Science.gov (United States)

We report the growth and characterization of a Si-doped, n-type AlGaN layer with 45% Al composition. For the application of n-type AlGaN layers with high Al compositions in ultraviolet emitters, we fabricated an n-Al0.45Ga0.55N layer with high crystalline quality and high electrical conductivity by inserting Al0.85Ga0.15N/AlN superlattices (SLs) to prevent cracks prior to growing the n-type AlGaN layer. The dislocation density in the n-AlGaN layer with a 45% Al composition and SLs was less than 2.4 × 1010 cm-2, which was lower than the dislocation density of 5.3 × 1010 cm-2 for the n-AlGaN layer without SLs. The resistivity, mobility, and free-electron concentration in the n-type Al0.45Ga0.55N layer with SLs were 2.2 × 10-2 ?·cm, 55.0 cm2/V-s, and 5.0 × 1018 cm-3 at room temperature, respectively.

Jeon, Seong-Ran; Park, Si-Hyun

2013-10-01

415

?????? ???????? ??????? ??????? 75 ?76 ?? ???? ????? Tafasir al-mufassirin al-qudama' li-l-ayatayn 75 wa 76 min surat al-Nahl (Ancient Interpretations of Surat an-Nahl 75 & 76)  

OpenAIRE

This article in Arabic surveys interpretations of the parabolic imagery in Qur'an 16:75-76 found in the classical commentators al-Tabari (d. 923), al-Razi (d. 1209), al-Qurtubi (d. 1272), al-Baydawi (d. 1282 or 1291), Ibn Kathir (d. 1373) and al-Jalalayn--Jalal al-Din al-Mahalli (d. 1459) and Jalal al-Din al-Suyuti (d. 1505). The full bibliographical reference in Arabic is: ????? ???. "?????? ???????? ??????? ??????? 75 ?76 ?? ???? ?????....

Hoover, Jon

2007-01-01

416

THE METHODOLOGY OF AL-MATURIDI’S QUR’ANIC EXEGESIS: Study of Ta’wilat Ahl al-Sunnah  

OpenAIRE

According to Islamic theology, al-Maturidi is one of the three prominent Muslim theologians of Ahl al-Sunnah wa al-Jama‘ah who are called aqt\\ab madhhab Ahl al-Sunnah wa’l-Jama‘ah (the leaders of Sunnite school of thought). In addition to his reputation as a theologian, al-Maturidi actually was competent in various Islamic sciences. In Qura’nic exegesis, he has Ta’wilat Ahl al-Sunnah or Ta’wilat al-Qur’an. Unfortunately, this fact isn’t known well by Islamic researchers. This ...

Ahmad Choirul Rofiq

2009-01-01

417

Recrystallization of FeAl and Ni3Al with and without boron  

International Nuclear Information System (INIS)

Since the brittleness of many strongly ordered intermetallic compounds at low temperature makes imparting sufficient strain for recrystallization difficult, there have been few reports of their recrystallization kinetics. The present paper reports a short study of the recrystallization kinetics of both polycrystalline Ni3Al and FeAl with and without boron, both of which have limited ductility at room temperature in the unalloyed polycrystalline state. In the present research, because of the difficulty of imparting sufficient deformation for recrystallization to both FeAl and boron-free Ni3Al, a hardness indentation method was used to study recrystallization. The idea is to introduce indentation and then determine the temperature at which recrystallization was initiated around the indentation after one hour. In this way, the effect of alloy stoichiometry and of boron on the recrystallization kinetics can be qualitatively assessed

418

Local stress-induced effects on AlGaAs/AlOx oxidation front shape  

Energy Technology Data Exchange (ETDEWEB)

The lateral oxidation of thick AlGaAs layers (>500?nm) is studied. An uncommon shape of the oxide tip is evidenced and attributed to the embedded stress distribution, inherent to the oxidation reaction. Experimental and numerical studies of the internal strain in oxidized Al{sub x}Ga{sub 1?x}As/GaAs structures were carried out by dark-field electron holography and finite element methods. A mapping of the strain distribution around the AlGaAs/oxide interface demonstrates the main role of internal stress on the shaping of the oxide front. These results demonstrate the high relevance of strain in oxide-confined III-V devices, in particular, with over-500-nm thick AlOx confinement layers.

Chouchane, F.; Almuneau, G., E-mail: almuneau@laas.fr; Arnoult, A.; Lacoste, G.; Fontaine, C. [CNRS, LAAS, 7 avenue du colonel Roche, F-31400 Toulouse (France); Univ de Toulouse, UPS, LAAS, F-31400 Toulouse (France); Cherkashin, N. [Univ de Toulouse, UPS, LAAS, F-31400 Toulouse (France); CNRS, CEMES, 29 Rue Jeanne Marvig, 31055 Toulouse Cedex 4 (France)

2014-07-28

419

Nb/Al-AlOx/Nb junctions with controllable critical current density for qubit application  

International Nuclear Information System (INIS)

Nb/Al-AlOx/Nb tunnel junctions with controllable critical current density JC are fabricated using the standard selective Nb etching process. Tunnel barriers are formed in different oxygen exposure conditions (oxygen pressure P and oxidation time t), giving rise to JC ranging from 100 A/cm2 to above 2000 A/cm2. JC shows a familiar linear dependence on P × t in logarithmic scales. We calculate the energy levels of the phase- and flux-type qubits using the achievable junction parameters and show that the fabricated Nb/Al-AlOx/Nb tunnel junctions can be used conveniently for quantum computation applications in the future. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

420

Plasma etching of AlN/AlGaInN superlattices for device fabrication  

International Nuclear Information System (INIS)

We report a study of plasma etching of GaN, AlN, and AlN/AlGaN superlattices for the processing of deep ultraviolet light emitting diodes. Etching was carried out using inductively coupled plasma of chlorine diluted with argon under reactive ion etching conditions. Using parameters selected for etch rate, anisotropy, and surface smoothness, we study etching of n- and p-type superlattices. The former etches at a rate of 250 nm/min, which is intermediate to that of AlN and GaN, while the latter exhibits a slower etch rate of 60 nm/min. Based on these studies, we prepare low-leakage p-n junctions and mesa light emitting diodes with peak emission at 280 nm

421

Mechanical properties of Al2O3/Al bi-layer coated AZ91 magnesium alloy  

International Nuclear Information System (INIS)

An Al2O3/Al bi-layered coating has been successfully deposited on AZ91 magnesium alloy using a filtered cathodic arc deposition system and favorable corrosion resistance has been demonstrated by our previous experiments. In this work, the mechanical properties of an Al2O3/Al bi-layered coating are studied by nanoindentation and nanoscratch. X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and scanning electron microscopy (SEM) are employed to characterize the structure of the coating. The surface hardness and elastic modulus of coated alloy are found to be enhanced dramatically. The coating also exhibits excellent bonding strength. In addition, the failure process of the coating during scratch is discussed.

422

Ag/Al2O3/FeAl(110): Electronic structure and NO2 adsorption  

Science.gov (United States)

Ag/Al2O3 systems are widely studied as catalysts in the selective catalytic reduction of NOx with hydrocarbons. The exact nature of the active sites and the role of the Ag clusters in such reactions is still not fully understood. In this study, we characterize thermally evaporated Ag clusters on the ultrathin alumina film produced by oxidizing FeAl(110). ARPES demonstrates the evolution of Ag cluster electronic structure and morphology with increasing Ag coverage. Changes in electronic binding energy distinguish charged from metallic clusters. Vibrational EELS of NO2 adsorbed on the Ag/Al2O3/FeAl(110) system elucidates the nature of the NOx binding site and the changes in the surface chemistry both as a function of Ag cluster size and NOx adsorption temperature.

Patterson, Matthew; Kizilkaya, Orhan; Kurtz, Richard; Sprunger, Phillip

2011-03-01

423

'Videokunst on tõsine asi,' räägib kunstnik Al Paldrock / Al Paldrok ; interv. Tiiu Leis  

Index Scriptorium Estoniae

Intervjuu Pärnu filmipäevade (2.-4. apr.) ühe peakorraldaja, Helsingis Kuvataide akadeemias video- ja keskkonnakunsti õppinud Al Paldrokiga filmipäevadest (kus esitatakse nii video-, reklaam- kui dokumentaalfilme), eesti filmist ja videokunstist, rühmitusest 'Vedelik'

Paldrok, Al, 1969-

1998-01-01

424

From Al4B2O9 nanorods to AlOOH (boehmite) hierarchical nanoarchitectures  

International Nuclear Information System (INIS)

Complex hierarchical nanoarchitectures of AlOOH (boehmite) have been synthesized from the prefabricated Al4B2O9 nanorods based on a hydrothermal self-assembled process without employing any templates/substrates or surfactants. XRD patterns, SEM and TEM images were used to characterize the products. The boehmite nanostructures which exhibit two hierarchies are built by small crystal strips that contain even smaller one-dimensional nanorods. The length of the small crystal strips is about 2 ?m and their diameter is about 100 nm in the middle section. Our investigation shows that the Al4B2O9 nanorods could separate the process of nucleation and growth, which is favoured for the formation of the hierarchical self-assembled nanoarchitectures. The growth mechanism has been proposed by the detailed microscopy observations. The thermal stability of the Al4B2O9 nanorods under hydrothermal conditions has also been discussed

425

AlInGaAs/AlGaAs strained single-quantum-well diode lasers  

International Nuclear Information System (INIS)

In this paper diode lasers with a strained AlInGaAs active layer and AlGaAs confining and cladding layers on GaAs substrates are reported for the first time. Broad-stripe devices were fabricated in GRIN-SCH SQE and SCH SQW structures that contain a single AlyInxGa1-x-yAs quantum well with 0.23 ? x ? 0.2 and 0.05 ? y ? 0.18. For Al0.18In0.20Ga0.62As, the emission wavelength is 814 nm. For a cavity length L = 1500 ?m, the threshold current density is as low as 103 A cm-2. For L = 280 ?m, the differential quantum efficiency is 90 percent. Preliminary tests of cw operation suggest that these lasers are more reliable than GaAs/AlGaAs lasers

426

ERPs and chronometry of face recognition: following-up Seeck et al. and George et al.  

Science.gov (United States)

Seeck et al. found that event-related potentials (ERPs) evoked by repeated and non-repeated face photographs differ as early as 50-70ms post-onset. They thus suggested that faces are recognized at these latencies, in contrast with current opinions in ERP literature. However, the similar latencies obtained by George et al. for stimuli not perceived as faces suggest that Seeck et al.'s differences could index repetition rather than face recognition per se. To address this issue, we used matched faces of known and unknown persons. We found the earliest differences between the ERPs to these faces between 76 and 130 ms. These results, which are consistent with other data, suggest that the differentiation of faces takes approximately 100 ms of processing time in humans. PMID:9855278

Debruille, J B; Guillem, F; Renault, B

1998-10-26

427

Adherent Al2O3 scales produced on undoped NiCrAl alloys  

Science.gov (United States)

Repeated oxidation and polishing of high purity Ni-15Cr-13Al has dramatically changed its cyclic oxidation behavior from nonadherent to adherent. No apparent change in scale phase, morphology or interface structure occurred during this transition, dismissing any mechanism based on pegging, vacancy sink, or growth stress. The principle change that did occur was a reduction in the sulfur content from 10 ppmw to 3 ppmw after 25 cycles at 1120 C. These observations are used to support the model of Al2O3 scale adherence put forth by Smeggil et al. which claims that Al2O3 scale spallation occurs due to sulfur segregation and bond deterioration at the oxide-metal interface.

Smialek, James L.

1986-01-01

428

Davidson y la crítica al empirismo  

Directory of Open Access Journals (Sweden)

Full Text Available Este artículo examina la crítica que Donald Davidson realiza a una de las doctrinas filosóficas más ampliamente aceptadas: el empirismo. El empirismo mantiene desde distintas perspectivas que la apelación a la experiencia es crucial para explicar alguno de nuestros más importantes conceptos y logros epistemológicos. Como se mostrará, la crítica de Davidson al empirismo es de gran calado, pues no sólo señala las incoherencias internas que algunas posiciones empiristas pueden plantear, sino los problemas que cualquier propuesta empirista está condenada a suscribir. Así mantiene que la experiencia, incluso en sus presentaciones más prometedoras, no puede realizar las tareas que los filósofos empiristas le encomiendan. Se finalizará argumentando que algunos intentos empiristas de evitar las críticas de Davidson fallan al reconocer el verdadero alcance de las mismas.

Jes\\u00FAs Coll M\\u00E1rmol

2008-01-01

429

Geschlecht als Vexierbild? Gender as a Puzzle?  

Directory of Open Access Journals (Sweden)

Full Text Available Jede Geschichte hat eine Vorgeschichte. Es ist das Verdienst von Rainer Herrn, mit dem hier angezeigten Buch die Frühgeschichte von Transgender auf- und nachgezeichnet zu haben, die sich in Berlin im ersten Drittel des 20. Jahrhunderts zugetragen hat. Verknüpft ist diese Geschichte vor allem mit dem Namen Magnus Hirschfeld, der bislang in erster Linie als Vorkämpfer für die Entkrimininalisierung der Homosexualität wahrgenommen wurde. Einen passenderen Titel als Schnittmuster des Geschlechts hätte der Autor für sein Buch nicht finden können.Every history has a prehistory. Rainer Herrn has produced an