WorldWideScience

Sample records for mehr als halbiert

  1. More than just a converter; Mehr als nur ein Umwandler

    Energy Technology Data Exchange (ETDEWEB)

    Wilming, Wilhelm

    2013-08-06

    Inverter can convert more than alternating current. With the presented new products at the INTERSOLAR in Munich the manufacturers are responding to the increased demands. [German] Wechselrichter koennen mehr als nur Wechselstrom umwandeln. Mit den auf der INTERSOLAR in Muenchen vorgestellten Produktneuheiten reagieren die Hersteller auf die gestiegenen Anforderungen.

  2. Mehr Last als Lust – Ein weiterer Sammelband zu „(Frauen-Körper“ More Encumbrance than Enjoyment

    Directory of Open Access Journals (Sweden)

    Paula-Irene Villa

    2006-11-01

    Full Text Available Dieser Band vereint acht heterogene Aufsätze zu „Lust und Last am eigenen Körper“ von Frauen. Alle Beiträge gehören zum Spektrum psychologischer Reflexion; die Themen reichen dabei von Sport über Kochen und Essen bis Schönheit, die Zugänge von Psychoanalyse über experimentelle Psychologie bis hin zu freier Assoziation auf der Grundlage klinisch-praktischer Arbeit. Ein roter Faden durch die Beiträge ist nicht erkennbar und so wirkt die Vielfalt beliebig. So unterschiedlich die Beiträge sind, so unterschiedlich ist auch ihre Qualität. Leider kommen einige Artikel über die unkritische Zusammenstellung anderer Arbeiten nicht hinaus, die meisten nehmen kaum Bezug auf das inzwischen breite und institutionalisierte Feld der (sozial- und kulturwissenschaftlichen Körperforschung. Doch haben manche Aufsätze interessante empirische Einblicke zu bieten, die zur weiteren Reflexion anregen, und einige wenige Beiträge sind so differenziert, dass sich mit ihnen weiterdenken und -forschen lässt. Insgesamt bereitet die Lektüre des Buches weder ‚Einsteiger/-innen‘ noch ‚Fortgeschrittenen‘ der wissenschaftlichen Beschäftigung mit (Frauen-Körpern Lust, sondern erweist sich – bis auf Ausnahmen, die allerdings auch in ausführlicherer Form anderenorts publiziert wurden – eher als Last. Ärgerlich und alles andere als argumentativ überzeugend ist darüber hinaus das in manchen Texten enthaltene, mehr oder minder explizit artikulierte, ‚Feminismus- bzw. Frauenforschungs-Bashing‘.This volume joins together eight heterogeneous essays by women under the theme “enjoyment and encumbrance of the body.” All of the contributions belong within the spectrum of psychological reflection; the themes range from sports, cooking and eating, and beauty, to the process of psychoanalysis, experimental psychology, and free-association based on clinical practice. The thread throughout the contributions remains indiscernible and thus the multiplicity seems arbitrary. And while the contributions vary, so too their quality. Unfortunately, some of the articles do not go beyond the uncritical compilation of other works and the majority of the essays barely make reference to the broad and long institutionalized field of research on the body in both social and cultural studies. However, some of the essays do offer interesting empirical insights that inspire the reader to reflect further and a select few are so wide-ranging that the reader can utilize the material for continued contemplation and research. Overall, academic scholars of (female bodies, be they “beginners” or more “advanced,” will not enjoy reading the essays in this book, but rather—with few exceptions, which, it fairs mentioning, have already been published elsewhere—find reading an encumbrance. What makes the book even more infuriating and everything but argumentatively convincing is that some of the texts engage in more or less explicitly articulated bashing of feminism and women’s studies.

  3. Mehr als ein Rechtshandbuch. Hinweise zur Arbeit von Frauen- und Gleichstellungsbeauftragten More Than a Legal Handbook. Details on the Work of Women’s and Equal Opportunity Commissioners

    Directory of Open Access Journals (Sweden)

    Arne Duncker

    2008-07-01

    Full Text Available Das vorliegende Handbuch für Frauen- und Gleichstellungsbeauftragte ist auch ein Rechtshandbuch, aber es geht in seinen Inhalten darüber hinaus. Etwa ein Drittel des Werkes behandelt außerrechtliche Fragen. Insgesamt ist das Werk als Leitfaden für die Praxis konzipiert und soll fortlaufend durch Nachlieferungen ergänzt werden; einige Rechtsmaterien, z. B. das Gleichstellungsrecht der meisten Bundesländer, sind gegenwärtig noch nicht enthalten. Während mit dem Arbeitsrecht ein zentraler Bereich der Gleichstellungspraxis recht umfassend und überwiegend gut behandelt wird und an verschiedenen weiteren Punkten teils hervorragende Teilbearbeitungen vorliegen, weist die Darstellung eines anderen zentralen Rechtsgebiets, des Familienrechts, gravierende Mängel auf. Insgesamt kann das Werk in seiner derzeitigen Form noch nicht vorbehaltlos empfohlen werden.The handbook for Women’s and Equal Opportunity Commissioners is also a legal handbook, but it goes beyond this in its contents. About a third of the work deals with extra-legal questions. In general, the work is conceived as a guideline for practice and the intention is that continual additions will supplement the work; some legal materials, for example the equality laws of most federal states, are currently not included. While a central area of equality praxis is extensively and for the most part appropriately handled through employment law and there are some excellent studies of other points, the handbook points to grave deficits in another area of law, and that is family law. Overall, the work cannot be recommended in its current form without reservations.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-09-15

    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.)

  5. Linnamaastike kaitse on osa arengust / Jukka Jokilehto, Mehr Azar Soheil ; intervjueerinud Liisa Pakosta

    Index Scriptorium Estoniae

    Jokilehto, Jukka

    2010-01-01

    Vestlus soome arhitekti, Nova Gorica ülikooli professori, UNESCO ja ICOMOSi konsultandi Jukka Jokilehto ja tema abikaasa, pärslannast arhitekti Mehr Azar Soheiliga. Ka Tallinna vanalinnast maailmapärandi komitees valmivate linnamaastike kaitseks mõeldud soovituste valguses, linna arengust sadama suunas. Eestikeelsena ilmus J. Jokilehto raamat "Arhitektuuri konserveerimise ajalugu" (Tallinn : Eesti Kunstiakadeemia, 2010)

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.)

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

    DEFF Research Database (Denmark)

    Andersen, John; Frandsen, Martin

    2008-01-01

    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.

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

    Index Scriptorium Estoniae

    2010-01-01

    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

  9. Expressionsbibliotheken als Werkzeuge für die Entwicklung von Subunit-Impfstoffen und neuartigen Detektionsmolekülen für Orthopockenviren

    OpenAIRE

    Miller, Lilija

    2011-01-01

    Nach der erfolgreichen globalen Ausrottung der Pockenkrankheit wurde die Pocken¬impfung aufgrund seltener aber schwerer Komplikationen eingestellt. Heute, nach mehr als 30 Jahren, weist die Mehrheit der Welt-Bevölkerung keinen Immun¬schutz mehr auf. Gleichzeitig steigt neben der Häufigkeit zoonotischer Pockenvirus¬infektionen mit Affen- oder Kuhpockenviren auch die Angst vor Bioterror-Anschlägen mit Variolaviren. Diese Entwicklungen unterstreichen die Notwendigkeit von Projekten, die vo...

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

    Directory of Open Access Journals (Sweden)

    Sh. Ayobi

    2006-07-01

    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.

  11. Communication technology in process automation - more than a field bus; Kommunikationstechnik in der Prozessautomatisierung - mehr als Feldbus

    Energy Technology Data Exchange (ETDEWEB)

    Schwibach, Martin [BASF SE, Ludwigshafen (Germany)

    2009-07-01

    In recent years, communication technology has come to play an increasingly important role in process automation. For many decades, standardized 4-20 mA electrical signals, which had replaced earlier pneumatic systems, remained the communication basis for nearly all automation technology applications. It was only in the 1990s, along with the sudden, exponential growth of IT, that a wind of change began sweeping through automation technology as well. This has had a profound and lasting impact on system architectures. Terms like HART, OPC and field bus are now familiar automation vocabulary. Networked automation systems have become the norm, and crosssystem communication, horizontal and vertical information integration, and remote access are routine. Reliability and availability. Sustainability and investment protection. These are the basic requirements that every new solution has to fulfill before it can be successfully employed in process plants. What does this mean in concrete terms? The use of modern communication technologies must not bypass the requirements made on previous and existing data transmission technologies. All current requirement profiles for conventional transmission systems must also be satisfied by network-based technologies, from field bus through to wireless. This is particularly important with regard to functional safety, availability, explosion protection, and EMC. More advanced requirements, such as interoperability, IT security or diagnostics must also be met. Over the years, NAMUR has published a series of papers on these topics which can serve as guidelines. The potentials for using modern communication technologies clearly lie in those areas where conventional solutions have proved uneconomic or unsuitable. Rather than simply achieving fault-free system operation, the overriding goal when implementing and further developing communication structures in automation technology should therefore always be to create new, value-adding applications that bring concrete benefits to the user. (orig.)

  12. Mehr als 85% aller Granularzellen im menschlichen Kleinhirn entstehen postnatal - ohne Unterschied zwischen plötzlichem Kindstod und Kontrollfällen

    OpenAIRE

    Kiessling, Maren

    2013-01-01

    Ziel der Hauptuntersuchung der vorliegenden Arbeit war die Überprüfung der Hypothese, dass sich beim plötzlichen Kindstod („sudden infant death syndrome“; SIDS) im Vergleich zu alters- und geschlechtsgematchten Kontrollen (d.h. bei Kindern, die innerhalb des ersten Lebensjahres nicht an SIDS verstorben waren), im Kleinhirn veränderte Gesamtzahlen von Purkinjezellen und Granularzellen finden. Hintergrund dieser Hypothese waren (i) Spekulationen in der Literatur über eine mögliche Rolle des Kle...

  13. EU ecodesign regulation. More as only a light bulb ban; EU-Oekodesign-Richtlinie. Mehr als ein Gluehbirnenverbot

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Corinna [Oeko-Institut e.V., Freiburg (Germany)

    2011-10-15

    Within a broader public, the EU Ecodesign Directive (Directive 2009/125/EC) was known and notoriously as a 'light bulb ban'. This resulted in strong emotions. But it has shown an impact in many other areas - usually unnoticed and often for the financial and practical benefits of the consumers. Now, the EU Commission wants to go one step further.

  14. CCSVI - Ein Erfahrungsbericht: Mehr Fragen als Antworten - mit einem Kommentar aus neurologischer Sicht von W. Lang, Wien

    Directory of Open Access Journals (Sweden)

    Peloschek P

    2011-01-01

    Full Text Available Obwohl schon seit über 100 Jahren bekannt ist, dass durch nahezu jeden demyelinisierten Herd (Plaque bei Multipler Sklerose (MS ein Blutgefäß läuft, konnte bisher kein kausaler Zusammenhang zwischen einer Erkrankung der zerebralen Venen und MS dargestellt werden. Nach der Beschreibung des Syndroms der chronischen zerebrospinalen venösen Insuffizienz (CCSVI im Jahr 2008 entwickelte sich ein, durch neuen Medien (Google, Facebook, Blogs etc. potenzierter, außergewöhnlich hoher Druck vonseiten zahlreicher Patientengruppen auf Ärzteschaft und Industrie, der hoffnungsgebenden Hypothese einer durch CCSVI bedingten ?venösen MS? nachzugehen. Dieser Bericht soll einen nüchternen Überblick über die fraglich ursächliche Beteiligung der Venen geben, um dem Leser die Möglichkeit zu geben, sich ein eigenes Bild zu machen.

  15. Adipositastherapie: Nahrung als Intervention

    Directory of Open Access Journals (Sweden)

    Wallner SJ

    2001-01-01

    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.

  16. Weniger ist mehr. Über die Theorie und Anwendung von schwachen und unscharfen Messungen in der Quantenmechanik

    OpenAIRE

    Konrad, Thomas

    2003-01-01

    In dieser Arbeit wird eine spezielle Klasse verallgemeinerter Messungen in der Quantenmechanik untersucht. Es handelt sich um sogenannte unscharfe Messungen. Mathematisch sind sie durch vertauschende Effekte und reine Operationen (d.h. reine Zustände werden durch den Messprozess auf reine Zustände abgebildet) gekennzeichnet. Physikalisch bedeutet das, man kann sie als Messungen herkömmlicher Messgrößen wie z.B. Energie, Ort oder Spin auffassen, und sie produzieren kein klassi...

  17. Barbara Paul, Johanna Schaffer: Mehr(wert queer – Queer Added (Value. Visuelle Kultur, Kunst und Gender-Politiken – Visual Culture, Art, and Gender Politics. Bielefeld: transcript Verlag 2009.

    Directory of Open Access Journals (Sweden)

    Julia Jäckel

    2010-03-01

    Full Text Available ‚Mehr Queer‘ lautet die Programmatik der Autor/-innen des Sammelbandes, die sich in ihren Beiträgen mit ästhetischen und politischen Praxen auseinandersetzen, welche die Ordnungsparameter der Binarität und Heterosexualität verunsichern. Der Titel Mehr(wert queer schließt dabei an ökonomische Semantiken an, um die Verwobenheit von symbolischer Kunst und ökonomischen Realitäten in den Blick zu bekommen, aber auch um aktiv an Umdeutungen mitzuwirken. Im Mittelpunkt stehen visuelle Kunst- und Bilderpolitiken, die Normalitätsdiskurse um Sexualität, Geschlecht und Begehren hinterfragen. Die Autor/-innen kommen aus den Kunst- und Kulturwissenschaften, den Medienwissenschaften, der Philosophie, aber auch aus der künstlerischen sowie der kunst- und kulturpolitischen Praxis.“More queer”: this is the program of the authors of this collected volume, who in their essays confront this program with aesthetic and political practice that disrupts the organizational frameworks provided by binary thinking and heterosexuality. The title Mehr(wert queer [Added (value queer] thus picks up on economic semantics in order to bring into focus the entanglement of symbolic art with economic realities, but also to contribute actively to reinterpretation. Central to the study is visual art and image politics, which question normative discourse surrounding sexuality, gender, and desire. The authors come from Art History and Cultural Studies, Media Studies, and Philosophy, but also artistic as well as art and culture political practice.

  18. Der Glaube als Erkenntnisquelle

    Directory of Open Access Journals (Sweden)

    Andrea Hartwig

    2004-03-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.)

  20. ASSESSMENT SPATIAL VARIABILITY OF SOIL ERODIBILITY BY USING OF GEOSTATISTIC AND GIS (Case study MEHR watershed of SABZEVAR

    Directory of Open Access Journals (Sweden)

    Ayoubi, S.A

    2005-05-01

    Full Text Available Soil erodibility is one of the key factors on some sediment and soil erosion models such as USLE, MUSLE, RUSLE, AUSLE (USLE modified in LS factor and MMF and represents like K factor and is function of particle distribution, organic mater, soil structure and ermeability. Traditional methods do not take spatial variability and estimate precision of variables in to consideration and amount of them are constant across the whole of soil series .This study was performed to assess spatial variability of soil erodibility and its relevant variables at MEHR watershed from Khorasan province, in northern Iran. Interested network was designed by 110 samples like nested- systematic with distance about 50, 100, 250 and 500 meter across the study area by preparing point map at GIS. Sampling points were identified in field by an Global Positioning system. Soil sampling was done at depth of 0-5cm of ground surface and permeability was studied at depth of 5-30 cm. Some soil properties such as particle distribution and organic mater were measured at laboratory. Particle size distribution was determined by Hydrometer method and Organic matter was measured by wet oxidation approach. Then spatial analysis was done. Variography analysis on soil attributes according to soil erodibility, showed that Gaussian, exponential and spherical models were the most models to predict spatial variability of soil parameters. The range of spatial dependencies was changed from 320 to 3200 m. Soil attribute maps prepared by kriging technique using models parameters. Then soil attributes were composed by Wischmeier (1978 formula in Illwis media to calculate K factor. Amount of soil erodibility changed from 0.13 to 0.91 that it's maximum and minimum was identified in east and southwest of studiedarea. Soil spatial variability pattern, is similar to silt pattern due to high effect of silt on soil rodibility, Also that is partially confirmed with geology map, indicated which soil erodibility attribute controlled by parent material. High amount of soil erodibility in southwest area of given study area showed need to more attention for conservation the soil and control erosion.

  1. Bakterielle Produktion von geschneiderten Wachsestern : Verwendung von Pflanzenöl und Einzelkomponenten als Kohlenstoffquelle und Wachsester-Precursor

    OpenAIRE

    Jenschke, Constanze

    2010-01-01

    Die bakterielle Produktion geschneiderter Wachsester (WE) durch das Bakterium Alcanivorax jadensis T9 auf Pflanzenöl und anderen organischen Substanzen wurde nachgewiesen. Ein Screening von mehr als 50 Bakterien zeigte, dass viele davon WE auf verschiedenen Pflanzenölen produzierten. Auf Rapsöl (RP) erzeugte WE ähnelten den WE des menschlichen Sebums. n-Fettsäuren, n-Alkohole, n-Alkane oder Triacylglyceride führten überwiegend zu WE mit direkt vom Substrat abgeleiteten Säure- und Alko...

  2. We experience more than we comprehend. Quantum physics and quaesions of life; Wir erleben mehr als wir begreifen. Quantenphysik und Lebensfragen

    Energy Technology Data Exchange (ETDEWEB)

    Duerr, H.P.; Oesterreicher, M.

    2007-07-01

    The quantum physics has been arrived by thinking and experimenting to revolutioning knowledges, which determine our world, also if only few have understood these theories in their real sense. The present book follows the question, whether and how far a consciousness trained by quantum physics can reach more directly to the understanding of questions of life and religious questions than a thinking, which is obliged to classical physics. It deals especially with fundamental existential questions: The theme of personal responsibility, the value of the indivdual existence, the evaluation of the personal I-you relation. Hans Peter Duerr, a personality with guiding qualities, as they are necessary in the new milennium, is the ideal speech partner for the deimension of this theme. The connections of natural sciences and religion, ecology, and sociological change have always driven the Heisenberg successo. How can we speech about that, which science cannot comprehend?. What means self, identity, responsibilit for the quantum physicist? An exciting meeting.

  3. 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)

    Guido Müller

    2002-07-01

    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.

  4. 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)

    De Ridder, Daniela

    2012-04-01

    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.

  5. Wind power engineering - Development and contribution to power supply; Windenergietechnik - Entwicklung und Beitrag zur Stromversorgung

    Energy Technology Data Exchange (ETDEWEB)

    Kleinkauf, W. [Kassel Univ. (Gesamthochschule) (Germany). Inst. fuer Elektrische Energietechnik; Hoppe-Kilpper, M. [Institut fuer Solare Energieversorgungstechnik (ISET), Kassel (Germany)

    2000-06-01

    The technology and the use of wind energy in Germany has impressively demonstrated that Federal and State programmes, but especially legal measures such as the electricity feed-in law as a minimum price regulation, are able to introduce developments which surpass even high expectations. Within 7 years, due to reliable conditions and technical progress, plant size was able to be increased almost ten-fold with plant availability boosted to over 98% and generating costs halved. In 1999, plants with approximately 4 GW will have been installed in Germany, which contribute more than 1.5% of the total electricity production. Wind energy technology, at least regionally, has become an economic factor in Germany and has created more than 10,000 jobs, Europe-wide this number is twice as much. Through extrapolation or a slight weakening in growth rates of new converter installations of recent years, a further increase in the proportion of wind energy in Germany, to about 5%, will be possible by the year 2007. (orig.) [German] Die Technik und Nutzung der Windenergie hat in Deutschland eindrucksvoll unter Beweis gestellt, dass begleitende Programme des Bundes und der Laender, insbesondere aber gesetzliche Massnahmen wie das Stromeinspeisungsgesetz als Mindestpreisregelung, in der Lage sind Entwicklungen einzuleiten, die selbst hoch gesteckte Erwartungen weit uebertreffen koennen. Innerhalb von 7 Jahren konnten aufgrund verlaesslicher Bedingungen und des technischen Fortschrittes die Anlagengroesse fast verzehnfacht, die Anlagenverfuegbarkeit auf ueber 98% gesteigert und die Stromgestehungskosten etwa halbiert werden. 1999 werden Windenergieanlagen mit ca. 4 GW in Deutschland installiert sein, die mit gut 1,5% zur Stromerzeugung beitragen werden. Damit ist die Windenergietechnik - zumindest regional - in Deutschland zu einem Wirtschaftsfaktor geworden und hat insgesamt mehr als 10000 Arbeitsplaetze geschaffen, europaweit sind es mehr als das Doppelte. Bei Fortschreibung bzw. leichter Abschwaechung der Wachstumsraten von den WEA-Neuinstallationen der letzten Jahre wird eine weitere Steigerung des Windstromanteils in Deutschland auf rund 5% bis 2007 moeglich sein. (orig.)

  6. AMANDA und DØ als Testumgebung für das LHC Computing Grid

    CERN Document Server

    Harenberg, Torsten

    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...

  7. What do we know more than 2012 on the accident progression in Fukushima? What is the actual state of the plant?; Was wissen wir heute mehr als 2012 ueber den Unfallablauf in Fukushima? Wie ist der heutige Zustand der Anlage?

    Energy Technology Data Exchange (ETDEWEB)

    Maqua, Michael [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) mbH, Koeln (Germany)

    2015-06-01

    The contribution includes the official statistics on the accident following the earthquake and tsunami on March 11, 2011 on the Japanese island Honshu and the nuclear power plant Fukushima Daiichi. The plant was automatically shutdown as consequence of the earthquake. New calculations allow the reconstruction of the accident progress and the meltdown. Estimations of the released radioactivity, esp. the radionuclides I-131 and Cs-137 into the atmosphere and the ocean are summarized. The construction of water cleaning facilities for the contaminated waste water in the leaking tanks, water-tight barriers and the planning for the enclosure for the destroyed reactor buildings are described.

  8. 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)

    Soydan, Nedim

    2010-05-01

    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.

  9. ALS Association

    Science.gov (United States)

    ... The ALS Association. Read More » Walk to Defeat ALS® Season Starts Now is the time to put ... walking shoes! Read More » The Leader in Global ALS Research The ALS Association has committed $99 million ...

  10. Strategien für mehr Arbeit und soziale Gerechtigkeit

    OpenAIRE

    Schulte, Dieter

    1997-01-01

    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 Folgen auf ...

  11. Der Glaube als Erkenntnisquelle Belief as the source of knowledge

    Directory of Open Access Journals (Sweden)

    Andrea Hartwig

    2004-03-01

    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.

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

    DEFF Research Database (Denmark)

    Bergenholtz, Henning

    2013-01-01

    "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.

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

    Directory of Open Access Journals (Sweden)

    Paul Winkler

    2014-12-01

    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.

  14. AL Amyloidosis

    OpenAIRE

    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

    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...

  15. AL Amyloidosis

    Directory of Open Access Journals (Sweden)

    Desport Estelle

    2012-08-01

    Full Text Available 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 of AL amyloidosis is the change in the secondary or tertiary structure of an abnormal monoclonal LC, which results in instable conformation. This conformational change is responsible for abnormal folding of the LC, rich in ? leaves, which assemble into monomers that stack together to form amyloid fibrils. Epidemiology AL amyloidosis is the most common type of systemic amyloidois in developed countries with an estimated incidence of 9 cases/million inhabitant/year. The average age of diagnosed patients is 65 years and less than 10% of patients are under 50. Clinical description The clinical presentation is protean, because of the wide number of tissues or organs that may be affected. The most common presenting symptoms are asthenia and dyspnoea, which are poorly specific and may account for delayed diagnosis. Renal manifestations are the most frequent, affecting two thirds of patients at presentation. They are characterized by heavy proteinuria, with nephrotic syndrome and impaired renal function in half of the patients. Heart involvement, which is present at diagnosis in more than 50% of patients, leading to restrictive cardiopathy, is the most serious complication and engages prognosis. Diagnostic methods The diagnosis relies on pathological examination of an involved site showing Congo red-positive amyloid deposits, with typical apple-green birefringence under polarized light, that stain positive with an anti-LC antibody by immunohistochemistry and/or immunofluorescence. Due to the systemic nature of the disease, non-invasive biopsies such as abdominal fat aspiration should be considered before taking biopsies from involved organs, in order to reduce the risk of bleeding complications. Differential diagnosis Systemic AL amyloidosis should be distinguished from other diseases related to deposition of monoclonal LC, and from other forms of systemic amyloidosis. When pathological studies have failed to identify the nature of amyloid deposits, genetic studies should be performed to diagnose hereditary amyloidosis. Management Treatment of AL amyloidosis is based on chemotherapy, aimed at controlling the underlying plasma clone that produces amyloidogenic LC. The hematological response should be carefully checked by serial measurements of serum free LC. The association of an alkylating agent with high-dose dexamethasone has proven to be effective in two thirds of patients and is considered as the current reference treatment. New agents used in the treatment of multiple myeloma are under investigation and appear to increase hematological response rates. Symptomatic measures and supportive care is necessary in patients with organ failure. Noticeably, usual treatments for cardiac failure (i.e. calcium inhibitors, ?-blockers, angiotensin converting enzyme inhibitors are inefficient or even dangerous in patients with amyloid heart disease, that should be managed using diuretics. Amiodarone and pace maker implantation should be considered in patients with rhythm or conduction abnormalities. In selected cases, heart and kidney transplantation may be associated with prolonged patient and graft survival. Prognosis Survival in AL amyloidosis depends on the spectrum of organ involvement (amyloid heart disease being the main prognosis factor, the severity of individual organs involved and haematological response to treatment.

  16. Ventilation in passive houses - good and bad experience gained as planner and user; Lueftung in Passivhaeusern gute und schlechte Erfahrungen - als Planer und Benutzer

    Energy Technology Data Exchange (ETDEWEB)

    Oehler, S. [oehler und arch kom architekten ingenieure, Bretten (Germany)

    2001-02-01

    The more a house is insulated, the more important are ventilation and illumination. This interrelation seems to have been forgotten again in the meantime. At present each new building in Europe is constructed air-sealed. Most building owners have some kind of strange idea about how fesh air finds its way through the outer walls to the interior. They imagine 'breathing walls'. This process does not occur in a single house as well as it does not happen in the space station MIR. If you want fresh air in order to improve your ability to concentrate, to feel more awake, or simply to improve your life expectation or if you do not want to live in rooms with used air or a draught, then you do not have any other remedy than to install a controlled ventilation plant. There is no alternative. In many known cases mouldy and completely wet outer walls can be avoided by a ventilation plant. (orig.) [German] Je mehr man ein Haus daemmt, desto wichtiger werden damit Lueftung und Belichtung. Diesen Zusammenhang scheint man zwischenzeitlich wieder vergessen zu haben. Heute wird in Europa jeder Neubau praktisch luftdicht hergestellt, jedoch haben die meisten Bauherren nach wie vor die diffuse Vorstellung, dass die frische Luft irgendwie durch die Aussenwaende ihren Weg nach innen finden wird. Man stellt sich 'atmende Waende' vor. Dieser Vorgang findet bei einem Haus genau so wenig statt wie bei der Weltraumstation MIR. Wenn Sie frische Luft haben moechten, um ihre Konzentrationsfaehigkeit, Ihre Wachsamkeit oder schlicht Ihre Lebenserwartung zu verbessern oder wenn Sie einfach nicht mehr in einem abgestandenen Mief oder einem zugigen Raum leben moechten, dann bleibt Ihnen nichts anderes uebrig, als eine kontrollierte Lueftungsanlage einzubauen. Dazu gibt es keinerlei Alternative. In vielen bekannten Faellen lassen sich damit auch schimmelige und durchgfeuchtete Aussenwaende vermeiden. (orig.)

  17. 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 ...

  18. Spondyloarthritis oder Morbus Bechterew: Neue Klassifikation der axialen Spondyloarthritis mit Morbus Bechterew als Endstadium

    Directory of Open Access Journals (Sweden)

    Schirmer M

    2011-01-01

    Full Text Available Mit einer Prävalenz von 0,6?1,9 % ist die axiale Spondyloarthritis (SpA der Sammelbegriff für eine Gruppe von entzündlichen rheumatischen Krankheiten, die vor allem das axiale Skelett und die Insertionsstellen der Sehnen am Knochen (Enthesen betreffen. Je nach Subtyp der SpA besteht eine unterschiedlich starke Assoziation mit dem MHC-I-Antigen HLA-B27. Entsprechend der ?Assessment of Spondyloarthritis International Society? (ASAS wird die SpA anhand der prädominant betroffenen Region in die periphere und die axiale Form unterteilt. Die aktuelle Klassifikation der axialen SpA erfolgt mittels der 2009 veröffentlichten ASAS-Kriterien. Bei Sakroiliitis in der Bildgebung müssen ? 1 SpAParameter, bei positivem HLA-B27-Befund ? 2 andere SpA-Parameter für die Klassifikation als SpA vorhanden sein. SpA-Parameter sind entzündlicher Rückenschmerz, Arthritis, Familienanamnese, Uveitis anterior, entzündliche Darmerkrankung, Psoriasis, Daktylitis, Enthesitis, gutes Ansprechen auf NSAR und HLA-B27-Positivität. Die Sensitivität dieser Kriterien liegt bei 82,9 %, die Spezifität bei 84,4 %. Für die axiale Beteiligung der Psoriasis arthropathica werden auch die ähnlichen CASPAR-Kriterien verwendet. Für die Klassifikation des Morbus Bechterew werden die 1984 modifizierten New York-Kriterien verwendet, bei denen neben spezifischen klinischen Kriterien radiologisch eine Sacroiliitis Grad 2 oder mehr bilateral oder Grad 3?4 unilateral vorhanden sein muss. Bei schwerem Verlauf kann prinzipiell jede Form der SpA mit einer axialen Beteiligung in einen Morbus Bechterew übergehen. Somit ist der Morbus Bechterew sowohl ein Subtyp der SpA, als auch eine mögliche Spätform anderer Subtypen. Zur Verlaufs- bzw. Therapiekontrolle werden sowohl bei axialer SpA als auch bei Morbus Bechterew spezifische Scores verwendet, um Krankheitsaktivität und Funktionsveränderungen zu dokumentieren (BASFI, BASDAI, ASDAS.

  19. 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)

    Krause, Matthias B.

    2011-05-15

    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.

  20. Our new buildings consume more energy than they should. Evaluation of consumption data of domestic buildings. Metering and evaluation of energy consumption in buildings with efficient thermal insulation; Unsere neuen Haeuser verbrauchen mehr als sie sollten. Bedarfs- und Verbrauchsdatenauswertung - Wohngebaeude - Untersuchung zur Ermittlung und Bewertung von Energieverbraeuchen im hochwaermegedaemmten Bauen

    Energy Technology Data Exchange (ETDEWEB)

    Gniechwitz, Timo (comp.)

    2010-03-15

    Optimum energetic standards in both new and older buildings, with a highly positive energy balance, is a general goal that requires consequent action and should be based on practical measurements rather than on theories. This is also important in view of the goal of climate protection. The Arbeitsgemeinschaft fuer zeitgemaesses Bauen e.V. (Association for Modern Building Construction) intends to promote the careful use of materials and energy resources. It has been investigating innovative products and new energy standards for several decades by studies that provided a basis for construction standards. The present publication presents consumption data that were acquired and evaluated in buildings with efficient thermal insulation. The theoretical data were compared with the measurements in order to obtain a better basis for economic efficiency calculations. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-12-31

    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)

  2. Amyotrophic Lateral Sclerosis (ALS)

    Science.gov (United States)

    NINDS Amyotrophic Lateral Sclerosis (ALS) Information Page Clinical Trials Natural History and Biomarkers of C9ORF72 ALS and FTD The purpose of ... Trials Organizations Additional resources from MedlinePlus What is Amyotrophic Lateral Sclerosis (ALS)? Amyotrophic lateral sclerosis (ALS), sometimes called Lou ...

  3. Intentionalität als Kippfigur

    OpenAIRE

    Grüttemeier, Ralf

    1999-01-01

    Doppeldeutige Bilder, die - je nach Einstellung ihres Betrachters - den Schattenriß am Fenster als Einbruch oder Flucht interpretieren lassen oder - wie im von Grüttemeyer gewählten Beispiel - die Wittgensteinsche Zeichnung als Ente oder Hase, sind uns als Kippfiguren bekannt. Die Intentionalität - in literarischen Texten ganz anders als in wissenschaftlichen - kann sich in vielfacher Weise auch als Kippfigur literarischer Interpretation darstellen, wenn das, was uns der Dichter sagen will, s...

  4. Mitochondrial pathobiology in ALS

    OpenAIRE

    Martin, Lee J.

    2011-01-01

    Amyotrophic lateral sclerosis (ALS) is the third most common human adult-onset neurodegenerative disease. Some forms of ALS are inherited, and disease-causing genes have been identified. Nevertheless, the mechanisms of neurodegeneration in ALS are unresolved. Genetic, biochemical, and morphological analyses of human ALS as well as cell and animal models of ALS reveal that mitochondria could have roles in this neurodegeneration. The varied functions and properties of mitochondria might render ...

  5. Initial Symptoms of ALS

    Science.gov (United States)

    ... world without ALS Join this nationwide movement by walking for those affected by ... cup, while another person may experience a change in vocal pitch when speaking. ALS is typically a disease that ...

  6. Pornographie als Metapher

    Directory of Open Access Journals (Sweden)

    Caroline Schubarth

    2010-02-01

    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.

  7. 57Fe in Al

    International Nuclear Information System (INIS)

    Moessbauer spectra of 57Fe in an Al-rich matrix were measured and evaluated. To study the Al6Fe phase, a stable Al6(MnFe) phase was prepared and Moessbauer parameters obtained. To explain the structure of the Al13Fe4 phase spectrum, the spectrum was measured with an externally applied field of 50 kOe. Moessbauer parameters were investigated of supersaturated Al-Fe alloys with Fe concentration ranging from 0.5 to 5.0 at-%. (A.K.)

  8. Volver al desarrollo

    Directory of Open Access Journals (Sweden)

    Jaime Ornelas Delgado

    2012-01-01

    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.

  9. Self-shunted Al/AlOx/Al Josephson junctions

    CERN Document Server

    Lotkhov, S V; Balashov, D V; Khabipov, M I; Buchholz, F I; Zorin, A B

    2006-01-01

    Self-shunted aluminum Josephson junctions with high-transparency barriers were fabricated using the shadow-evaporation technique and measured at low temperatures, T=25 mK. Due to high junction transparency, the IV-characteristics were found to be of only small hysteresis with retrapping-to-switching current ratio of up to 80%. The observed critical currents were close to the Ambegaokar-Baratoff values (up to 80-100%). Good barrier quality was confirmed by the low subgap leakage currents in the quasiparticle branches, which makes the self-shunted Al junctions promising for application in integrated RSFQ-qubit circuitry.

  10. Schulabsentismus als Forschungsgegenstand

    OpenAIRE

    Ricking, Heinrich

    2003-01-01

    Die von Herrn Ricking vorgelegte Arbeit "Schulabsentismus als Forschungsgegenstand - Eine narrative Metaanalyse zum Schulabsentismus" ist von ihrer Themenstellung her als innovativ, eigenständig, bisher kaum bzw. in dieser Form nicht bearbeitet und fachlich hoch relevant einzuschätzen. Die wissenschaftliche Auseinandersetzung mit diesem Thema - insbesondere eine erfahrungswissenschaftlich besser abgesicherte - und mit den Fragen nach den Grundlagen, Ursachen, Begleitfaktoren, Wechselwi...

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.)

  12. Relevanz der 2,4-Dienoyl-CoA Reduktase von Leishmania mexicana und major auf die Virulenz

    OpenAIRE

    Paape, Daniel

    2010-01-01

    Bestandteil dieser Arbeit waren zwei Proteomanalysen des Parasiten Leishmania mexicana. In der ersten wurde das Proteom von aus ihrem intrazellulären Habitat aufgereinigten Amastigoten, mit dem Proteom von Promastigoten, der extrazellulären Lebensform, verglichen. Der Fokus der zweiten Proteomanalyse war die Identifizierung von bei Amatigoten sezernierten Proteinen. Insgesamt wurden mehr als 1800 Proteine identifiziert, von denen mehr als 740 zuvor noch nicht detektiert worden waren. Die...

  13. 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

  14. Altern als Widerstand

    Directory of Open Access Journals (Sweden)

    Roberta Maierhofer

    2005-07-01

    Full Text Available Gullettes kulturwissenschaftliche Untersuchung Aged by Culture ist wie bereits ihre zwei vorangehenden Werke, die sich mit Altern beschäftigen – Safe at Last in the Middle Years: The Invention of the Midlife Progress Novel (1988 und Declining to Decline. Cultural Combat and the Politics of the Middle (1997 –, von großem persönlichen Engagement und durch ein politisches Anliegen motiviert. Sowohl die Dringlichkeit als auch der Widerstand, den Gullette, die sich als „age critic“ definiert, als moralische und politische Notwendigkeit postuliert, werden in der Zweiteilung der Abhandlung angesprochen: „Cultural Urgencies“ und „Theorizing Age Resistantly“. Während Gullette den Begriff „aged by culture“ bereits in Declining to Decline einführt, stellt sie ihn nun in den Mittelpunkt ihrer Untersuchung. Das Buch ist einerseits einer gesellschaftspolitischen Analyse der USA gewidmet, andererseits wird eine Theorie des Widerstands gegenüber Altersdiskriminierung entwickelt.

  15. Pornographie als Metapher

    Directory of Open Access Journals (Sweden)

    Caroline Schubarth

    2010-03-01

    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.

  16. Carta al Editor

    Directory of Open Access Journals (Sweden)

    José Andrés Burgos Zuleta

    2010-06-01

    Full Text Available La medicina al basarse generalmente en la clínica, correlacionaexámenes complementarios y organiza un diagnóstico y tratamiento, es una disciplina donde es imprescindible saber recolectar, analizar, interpretar y concretar una respuesta adecuada, es así que la información que se recibe es esencial para el desempeño médico.La certeza es una realidad que se da en algunas situaciones y enotras las probabilidades establecen conclusiones. Lo normal muchas veces se define sobre la base de criterios estadísticos, basados en riesgos poblacionales que no necesariamente se aplican al caso boliviano.

  17. 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

  18. X-ray detection with Nb/Al/AlOx/Al/Nb tunneling junctions

    International Nuclear Information System (INIS)

    A whole wafer fabrication procedure using selective etching of refractory materials to produce Nb- or Ta/Al/AlOx/Al/Nb tunneling detectors is discussed. Fabrication aspects and preliminary results are presented. (author) 2 figs., 5 refs

  19. Nucleosynthesis of 26Al

    International Nuclear Information System (INIS)

    A burst of interest has followed the discovery in the galactic plane of the 1.8 MeV gamma line attached to the decay of 26Al. We discuss the relative merits of supernovae, novae, massive and supermassive mass-losing stars as potential sources of this expressive isotope

  20. Bâb al–Yaman

    Directory of Open Access Journals (Sweden)

    Roman Stadnicki

    2006-10-01

    Full Text Available Bâb al–Yaman, porte méridionale de la ville de Sanaa, est devenue, un siècle après sa reconstruction, à la fois le symbole d’une identité urbaine héritée et l’emblème de la vitalité politique et culturelle du Yémen. C’est l’analyse de la persistance et de la symbolisation d’une forme urbaine archétypale qui est ici proposée à travers une triple lecture : celle des perceptions des citadins qui recentrent la porte dans les pratiques spatiales, celle, interprétative, des représentations iconographiques de Bâb al–Yaman qui s’inscrivent dans un processus de valorisation des richesses patrimoniales et culturelles du pays, et, enfin, celle des discours de quelques acteurs institutionnels qui font de la porte un objet de revendications.One century after its reconstruction, the southern gate of Sana’a, Bâb al–Yaman, has become not only the symbol of an ancient urban identity but also the emblem of Yemen’s political and cultural vitality. This article analyses the persistence and the symbolization of such an archetypal urban form through three levels of interpretations: first, the city dwellers’ perceptions, which replace the gate in spatial practices; then the iconographic representations of Bâb al–Yaman, which are in line with the process of promotion of Yemen’s patrimonial and cultural treasures; and last but not least, the discourse analysis of some institutional actors, who have turned the gate into an object of claim.

  1. ALS renewal moves forward

    International Nuclear Information System (INIS)

    As the result of an extensive long-term planning process involving all its stakeholders-management, staff, and users-the ALS has seen its future and is aggressively moving ahead to implement its vision for keeping the facility at the cutting edge for the next 2-3 decades. The evolving strategic plan now in place aims to renew the ALS so it can address a new generation of fundamental questions about size dependent and dimensional-confinement phenomena at the nanoscale; correlation and complexity in physical, biological, and environmental systems; and temporal evolution, assembly, dynamics and ultrafast phenomena. The renewal spans three areas: (1) increased staffing at beamlines to support the growing user community and safety professionals to keep an increasingly complex facility hazard free; (2) implementing advances in accelerator, insertion device, beamline, and detector technology that will make it possible for ALS users to address emerging grand scientific and technological challenges with incisive world-class tools; and (3) construction of a user support building and guest housing that will increase the safety and user friendliness of the ALS by providing users office, meeting, experiment staging, and laboratory space for their work and on-site accommodations at reasonable rates

  2. MDA ALS Caregiver's Guide

    Science.gov (United States)

    ... that arise when a loved one has a progressive, debilitating illness. These pages contain practical and emotional strategies for being an effective caregiver. The MDA ALS Caregiver’s Guide is meant to give guidance, assistance and advice in many aspects of caring for a person you love who ...

  3. aplicación al monopolio constitucional?

    Directory of Open Access Journals (Sweden)

    Miguel \\u00C1ngel Fern\\u00E1ndez Gonz\\u00E1lez

    2005-01-01

    Full Text Available El autor reflexiona sobre si a través de la Casación la Corte Suprema de Justicia se involucraría en el control de constitucionalidad, al considerar la Constitución como ley en sentido amplio del término, con lo cual el control concentrado de constitucionalidad en el Tribunal Constitucional que pretende la reforma constitucional se encontraría con algunos problemas. El autor reflexiona sobre la materia desde la perspectiva de un constitucionalismo que denomina humanista en contraposición a un constitucionalismo estatalista, estableciendo el enfoque básico del primero, su evolución y estado actual, fortaleciendo la fuerza normativa de la Constitución como lo hace el artículo 6° de la Carta Fundamental, además de la obligación de todo Tribunal de interpretar la Constitución en conformidad con la Constitución, posición que adecuadamente fundamentada lo lleva a concluir que la reforma constitucional en curso, no confiere la interpretación de la Constitución únicamente al Tribunal Constitucional, sino que ella debe ser aplicada en conformidad a la Constitución por todos los Tribunales.

  4. 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

  5. Introducción al comportamiento estructural

    OpenAIRE

    Cervera Bravo, Jaime; Jaenicke Cendoya, Ignacio; Ruiz Palomeque, Luis Gerardo; Sanchez Quiroga, Luis; Asenjo, Jose?

    1982-01-01

    Texto de introducción al panorama teórico (y de aplicación) necesario para abordar el análisis y el proyecto de las estructuras de edificación: Se detallan los problemas abordados así como el lenguaje y los conceptos básicos de la teoría y sus relaciones con la realidad física y constructiva, de la que se presenta una tipología básica. Se presentan las relaciones fundamentales entre conceptos (y sus expresiones matemáticas).

  6. 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

  7. 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)

    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

    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.)

  8. Carta al Editor

    Directory of Open Access Journals (Sweden)

    Jean Pierre Delmont

    2009-06-01

    Full Text Available Estimada Editora en Jefe¡Le felicito por la calidad de vuestra Revista y el trabajo realizado! ¡Al igual que Usted, soy un amante de laciencia (se utiliza 2 veces esta palabra en el título de vuestra Revista! y persuadido que debe ser la base denuestro trabajo. Por supuesto la medicina no es solamente una ciencia. Fue originalmente filosofía y ética, conlos griegos en el Siglo V a.C., arrancándola de las manos de los sacerdotes o brujos, y obligando a los médicosa seguir reglas morales (Juramento Hipocrático Además es un arte (no en su sentido estético sino de oficio,de artesanía.

  9. Gliricidia sepium al establecimiento

    Directory of Open Access Journals (Sweden)

    J. L. Valle

    2004-01-01

    Full Text Available Se asoció Cenchrus ciliaris (Cc y Gliricidia sepium (Gs para evaluar la producción de biomasa y la composición química de los forrajes en la fase de establecimiento, en el estado de Morelos, México, en condiciones de trópico seco. Se empleó un análisis de varianza con diseño en bloques al azar, en donde T1 fue pasto solo, T2 Cc más Gs con 5,000 plantas ha-1 y el T3 Cs más Gs con 14,285 plantas ha-1. Se midió la producción de forraje individual y asociado con materia seca (t MS/Ha, la altura (A en cm, la proteína cruda (PC%, las fracciones de fibra (FDN% y FDA% y la digestibilidad in vitro de la materia seca (DIVMS%. El T3 tuvo una mejor producción de biomasa (P0.05. La asociación de 14,285 plantas ha-1 de G. sepium con pasto Cenchrus ciliaris mejoró la producción de biomasa y la disponibilidad total de nutrientes por superficie cultivada al establecimiento

  10. Huerta al alba

    Scientific Electronic Library Online (English)

    Carlomagno, Sol Tlachi.

    2014-12-01

    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.

  11. COMENTARIO AL CASO PINOCHET

    Scientific Electronic Library Online (English)

    Alberto, Contreras Clunes.

    Full Text Available El fallo en el caso Pinochet tiene distintas formas de ser analizado. De partida, desde un punto de vista político, también constitucional, del derecho penal. Sin embargo, nos abocaremos al estudio desde el punto de vista procesal, en especial a lo referido al Debido Proceso. Para ello se analizará [...] los presupuestos, la solución dada por la Excma. Corte Suprema y las consecuencias del mismo. Además, se criticará la solución dada, desde la óptica de las garantías procesales del imputado, contenidas en el nuevo proceso penal y lo dispuesto en la Constitución y la Convención Americana de Derechos Humanos. Finalmente, se argumentará en favor de una interpretación finalista y armónica de la Constitución y los tratados internacionales de derechos humanos. Abstract in english The verdict of the Pinochet Case has different ways of being analyzed: from the political, the constitutional, and the penal law points of view. However, we will approach this study from the legal point of view, especially to that referred to as the Proper Process. To do this, the budgets, the solut [...] ion given by the Most Excellent Supreme Court, and its consequences will be analyzed. Furthermore, the given solution will be criticized from the point of view of the legal guarantees of the accused contained in the new penal process and what is contained in the Constitution and in the American Convention of Human Rights. In conclusion, we will argue in favor of a final and harmonious interpretation of the Constitution and the international agreement of human rights.

  12. COMENTARIO AL CASO PINOCHET

    Directory of Open Access Journals (Sweden)

    Alberto Contreras Clunes

    2002-01-01

    Full Text Available El fallo en el caso Pinochet tiene distintas formas de ser analizado. De partida, desde un punto de vista político, también constitucional, del derecho penal. Sin embargo, nos abocaremos al estudio desde el punto de vista procesal, en especial a lo referido al Debido Proceso. Para ello se analizará los presupuestos, la solución dada por la Excma. Corte Suprema y las consecuencias del mismo. Además, se criticará la solución dada, desde la óptica de las garantías procesales del imputado, contenidas en el nuevo proceso penal y lo dispuesto en la Constitución y la Convención Americana de Derechos Humanos. Finalmente, se argumentará en favor de una interpretación finalista y armónica de la Constitución y los tratados internacionales de derechos humanos.The verdict of the Pinochet Case has different ways of being analyzed: from the political, the constitutional, and the penal law points of view. However, we will approach this study from the legal point of view, especially to that referred to as the Proper Process. To do this, the budgets, the solution given by the Most Excellent Supreme Court, and its consequences will be analyzed. Furthermore, the given solution will be criticized from the point of view of the legal guarantees of the accused contained in the new penal process and what is contained in the Constitution and in the American Convention of Human Rights. In conclusion, we will argue in favor of a final and harmonious interpretation of the Constitution and the international agreement of human rights.

  13. al trasplante de órganos

    Directory of Open Access Journals (Sweden)

    Mar\\u00EDa \\u00C1ngeles P\\u00E9rez San Gregorio

    2005-01-01

    Full Text Available El trasplante de órganos es una alternativa terapéutica para aquellos pacientes que tienen problemas graves en el funcionamiento de un órgano vital: corazón, hígado, pulmón, etc. Dada la relevancia de este tema, en el presente estudio teórico analizamos los principales problemas psicológicos asociados al trasplante de órganos. Concretamente, hemos tenido en cuenta los siguientes apartados: 1 Repercusiones psicológicas del trasplante de órganos en los pacientes: delirium, trastornos sexuales, trastornos del estado de ánimo, trastornos de ansiedad, fantasías sobre el donante, insatisfacción con la imagen corporal y otros trastornos; 2 variables psicosociales que influyen en las repercusiones psicológicas asociadas al trasplante de órganos: apoyo familiar, trastornos psicológicos en los familiares, hospitalización, expectativas pre y post-trasplante, estrategias de afrontamiento, duración de la enfermedad, etiología del trasplante, procedencia del órgano implantado y otras variables; 3 fases psicológicas en los trasplantados renales, hepáticos y cardíacos en función de diferentes periodos temporales de comparación; 4 calidad de vida en los trasplantados y variables que la predicen: adherencia terapéutica, hospitalización, apoyo familiar, expectativas hacia el trasplante y etiología del trasplante; y 5 repercusiones psicológicas del trasplante de órganos en los familiares, teniendo en cuenta la influencia que ejerce el apoyo social sobre la salud mental de estos familiares.

  14. Derivados vinculados al seguro.

    Directory of Open Access Journals (Sweden)

    De Paz Cobo, Sonia

    2003-01-01

    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

  15. Benefits for Military Veterans with ALS

    Science.gov (United States)

    Home About ALS About Us Our Research In Your Community Advocate Help fight ALS Donate What you can do to #ChallengeALS For People with ALS and Caregivers Newly Diagnosed Clinical Trials Familial ALS ...

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

    Directory of Open Access Journals (Sweden)

    Boeder, Niklas

    2013-02-01

    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.

  17. Studies of 27Al NMR in EuAl4

    Science.gov (United States)

    Niki, H.; Nakamura, S.; Higa, N.; Kuroshima, H.; Toji, T.; Yogi, M.; Nakamura, A.; Hedo, M.; Nakama, T.; ?nuki, Y.; Harima, H.

    2015-03-01

    EuAl4 orders antiferromagnetically at TN ? 16 K with an effective magnetic moment of 8.02 ?B. In the paramagnetic phase, the magnetic susceptibility of EuAl4 follows the Curie-Weiss law with a positive Curie-Weiss temperature ?P = +14 K. The antiferromagnetic state is changed into the field induced ferromagnetic state at a critical field Hc of approximately 2 T. In order to microscopically investigate the magnetic and electronic properties in EuAl4, the NMR measurements of EuAl4 have been carried out at temperatures between 2 and 300 K, applying an external magnetic field of approximately 6.5 T. The 27Al NMR spectra corresponding to Al(I) and Al(II) sites are obtained. From the 27Al NMR spectra, the isotropic part Kiso and anisotropic part Kaniso of Knight shift, and nuclear quadrupole frequncy ?Q are obtained. The Kiso and Kaniso shift to negative side with decreasing temperature due to the RKKY interaction. These temperature dependences follow the Curie-Weiss law with ?P = +14 K, which is consistent with that of the magnetic susceptibility. From the K – ? plot, the values of the hyperfine fields Hhf_iso and Hhf_aniso are -3.231 and -0.162 kOe/?B for Al(I) site, and -1.823 and -0.264 kOe/?B for Al(II) site, respectively. The values of ?Q of 27Al nucleus for Al(I) and Al(II) sites are approximately 0.865 and 0.409 MHz, respectively. The nuclear relaxation time T1 of 27Al NMR for both sites is almost constant in the paramagnetic phase, while the value of 1/T1 is abruptly decreased in the ordered ferromagnetic state.

  18. Schleswig-Holstein Energie 2020. Green paper. More power, more economy. - Schleswig-Holstein; Schleswig-Holstein Energie 2020. Gruenbuch. Mehr Energie. Mehr Wirtschaft - Schleswig-Holstein

    Energy Technology Data Exchange (ETDEWEB)

    Sauer, G.W. (comp.)

    2007-06-15

    The paper shows that Schleswig-Holstein, Germany's northermost state, will by 2020 be capable of covering more than 100 percent of its power demand on the basis of wind power and biomass. Wind power is an important technological, economic, labour-political and exports factor. (orig.)

  19. APROXIMACIÓN AL CONSTITUCIONALISMO POPULAR

    Directory of Open Access Journals (Sweden)

    Daniel Eduardo Florez Muñoz

    2012-04-01

    Full Text Available RESUMOEn el presente trabajo se expondrán las principales líneas de pensamiento de la corriente de pensamiento iusconstitucional norteamericana conocida como Popular Constitutionalism. Al interior de la cual se realiza un frontal cuestionamiento de las bases democráticas que presuntamente detentan las lecturas del constitucionalismo soportadas en la desconfianza hacia la intervención de pueblo como instancia de decisión política concreta. Palavras- chave: Constitución, Pueblo, Tribunal Constitucional, Control de Constitucionalidad. APPROACH TO POPULAR CONSTITUTIONALISM ABSTRACT In this paper we will present the main lines of thought school of thought known as American iusconstitucional Popular Constitutionalism. Inside the front which makes a questioning of the alleged hold democratic foundations of constitutionalism readings supported the suspicion of the involvement of people, as an actual politic decision. Key-words: Constitution, People, Constitutional Court, Judicial Review. SUMÁRIO1. Introducción 2. Los Orígenes: La clausura del universo político. 3. La Objeción Contramayoritaria. 4. En qué se reconoce el Constitucionalismo Popular? 5. Tipología del Constitucionalismo Popular.

  20. Religionspädagogik als Fachdidaktik

    Directory of Open Access Journals (Sweden)

    Andrea Lehner-Hartmann

    2014-07-01

    Full Text Available ENGLISH: One chapter of the Austrian National Education Report 2012 explicitly discusses the role of special subject didactics in educational contexts. The considerations of the present paper are due to the fact, that the report is not concerned with religious didactics. Within the academic dialogue between theological disciplines, religious education (as an academic discipline is often connoted with the narrow understanding as “the theory of religious education in schools”. From the perspectives of other specific subject didactics and educational policy it does not seem to be evident, that religious education as an academic discipline also performs tasks of religious didactics. The present paper discusses examples of divergent views on this topic and identifies challenges for subject didactics in general. Finally, it formulates desiderata for the further development of religious didactics based on the analysis of its status quo. DEUTSCH: Im nationalen Bildungsbericht des österreichischen BIFIE des Jahres 2012 gibt es ein eigenes Kapitel über die Rolle der Fachdidaktiken. In diesem Text kommt die Fachdidaktik Religion nicht vor. Diese Wahrnehmung ist der Ausgangspunkt für die Überlegungen dieses Beitrages: Religionspädagogik wird im Gespräch zwischen den theologischen Fächern oft – verkürzt – als Theorie des Religionsunterrichtes, und damit als Fachdidaktik des Unterrichtsfaches Religion wahrgenommen. Anders verhält es sich offenbar aus einer Außenperspektive: Von Seiten anderer Fachdidaktiken oder auch von Seiten der Bildungspolitik ist es nicht von vorneherein evident, dass Religionspädagogik auch die Aufgabe einer Fachdidaktik Religion wahrnimmt. Dieser Beitrag nennt Beispiele für diese divergierenden Sichtweisen, geht Herausforderungen an Fachdidaktik insgesamt nach und formuliert auf der Grundlage einer Analyse des IST-Standes der Fachdidaktik Religion Desiderate für deren Weiterentwicklung.

  1. PENSAR AL SUR

    Directory of Open Access Journals (Sweden)

    Juan Obarrio

    2013-07-01

    Full Text Available Resumen:Este articulo explora la cuestion de la definicion y territorialidad del Sur Global, evocando categorias que en el pasado han definido el espacio del "tercer mundo" o "mundo en desarrollo", y como estas han dado paso a una nueva conceptualizacion a partir de los debates sobre globalizacion. Se postula al Sur como una forma de vida, y como un espacio de historias paralelas de poder, capital y subjetivacion.A partir de esta discusion, se plantea de que manera en el presente el Sur Global es un espacio de produccion innovador de teorizacion sobre lo social, que genera sus propias disciplinas y marcos epistemologicos.Palabras Claves: Sur Global , globalizacion, epistemologia Abstract:This article explored the definition and territorial scope of teh Global South, evoking past categories that have defined the space of the "Third world" or teh "developing world", and how they have paved the way to new conceptualiziations, since the beginning of the debate on globalization. The essays posits the South as a form of life and as a space of parallel histories of power, capital and subjectivation.Departing from this discussion, the essay poses the question about the way in which currently the Global Southconstitutes an innovative space of theorization of the social,qhich generates its own disciplines and epistemological frameworks. Keywords: Global South, globalization, epistemology

  2. EL CÁNTARO AL AGUA

    Scientific Electronic Library Online (English)

    Pablo R, Arango.

    2007-09-01

    Full Text Available Este artículo es una respuesta a las objeciones que plantean Ignacio Ávila y Leonardo Cárdenas contra mi defensa de la metafísica esencialista. Se insiste en que el esencialismo puede ser compatible con la relatividad conceptual, y en que dicha metafísica puede hacer frente a la objeción según la cu [...] al debe irrespetar la máxima de que dos expresiones coextensivas son intercambiables salva veritate. Contra las observaciones de Cárdenas, se muestra que el esencialismo puede hacer uso, sin problemas, de ejemplos que apelan a los hechos institucionales, y que la idea de que sólo puede haber modalidades de dicto constituye una petición de principio si se la utiliza como argumento contra el esencialismo. Abstract in english This paper replies to independent objections by Ignacio Ávila and Leonardo Cárdenas against my defense of an essentialist metaphysics. I argue, again, that essentialism may be compatible with conceptual relativity, and that such metaphysics can face the objection according to which it is forced to b [...] e disrespectful of the dictum that two coextensive statements are interchangeable salva veritate. Against Cárdenas' views, I show that essentialism may use, without trouble, examples that appeal to institutional facts, and that the idea that there can be only de dicto modalities is question begging if it is used as an argument against essentialism.

  3. Is there a paraneoplastic ALS?

    Science.gov (United States)

    Corcia, Philippe; Gordon, Paul H; Camdessanche, Jean-Philippe

    2015-06-01

    Our objective was to examine the strength of evidence in support of the paraneoplastic syndrome (PNS) as one cause of ALS and, if the association appears more likely than chance, determine which features of ALS imply concurrent malignancy. We reviewed the literature on concurrent ALS and neoplasia assessing the strength of evidence for the association. Most accounts of ALS and neoplasm are case reports or small uncontrolled series. In order of strength of evidence, three clinical situations that support a paraneoplastic aetiology for ALS are: 1) laboratory evidence of well-characterized onconeuronal antibodies, most often anti-Hu, anti-Yo or anti-Ri; 2) co-occurrence of ALS and a neoplasm known to cause PNS, usually lymphoma or cancer of the breast; and 3) combined ALS and a neoplasm not classically associated with PNS, without detectable onconeuronal antibodies. Clinical features that warrant evaluation of neoplasm include upper motor neuron disease in elderly females, rapid progression, non-motor signs, and young onset. In conclusion, most examples of ALS and neoplasm do not constitute a classically established PNS. Rare instances of elevated onconeuronal antibody titres or typical neoplasm, implies that, albeit rare, the PNS is one of a multitude of causes of ALS. PMID:25285651

  4. 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

  5. Al versus Si competition in FeSiAl alloys

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

  6. The cathodic dissolution of Al, Al{sub 2}Cu, and Al alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ogle, K., E-mail: kevin-ogle@chimie-paristech.f [Ecole Nationale Superieure de Chimie de Paris, ParisTech, 11 rue Pierre et Marie Curie, 75005 Paris (France); Serdechnova, M.; Mokaddem, M.; Volovitch, P. [Ecole Nationale Superieure de Chimie de Paris, ParisTech, 11 rue Pierre et Marie Curie, 75005 Paris (France)

    2011-01-15

    The cathodic dissolution of aluminum has been investigated for 99.99% Al, synthetic Al{sub 2}Cu, and three Al-Cu-Mg alloys: AA2024, AA7050, and AA2214 offering a range of over two orders of magnitude in hydrogen reduction activity. Atomic emission spectroelectrochemistry (AESEC) was used to directly measure the dissolution rate of the alloy components as a function of the cathodic current during potential sweep and potential step experiments. It was found that for all samples, regardless of the cathodic current density, the stoichiometric ratio of OH produced to Al dissolved varied between 1.4 and 1.8. This value is interpreted in terms of a simple model in which hydroxide generation, Al(OH){sub 3} formation/dissolution, and Al(OH){sub 4}{sup -} diffusion are kinetically coupled together. The selective dissolution of Mg and Cu is also measured and discussed.

  7. The cathodic dissolution of Al, Al2Cu, and Al alloys

    International Nuclear Information System (INIS)

    The cathodic dissolution of aluminum has been investigated for 99.99% Al, synthetic Al2Cu, and three Al-Cu-Mg alloys: AA2024, AA7050, and AA2214 offering a range of over two orders of magnitude in hydrogen reduction activity. Atomic emission spectroelectrochemistry (AESEC) was used to directly measure the dissolution rate of the alloy components as a function of the cathodic current during potential sweep and potential step experiments. It was found that for all samples, regardless of the cathodic current density, the stoichiometric ratio of OH produced to Al dissolved varied between 1.4 and 1.8. This value is interpreted in terms of a simple model in which hydroxide generation, Al(OH)3 formation/dissolution, and Al(OH)4- diffusion are kinetically coupled together. The selective dissolution of Mg and Cu is also measured and discussed.

  8. estigma tolerable al estigma intolerable

    Directory of Open Access Journals (Sweden)

    Nelson Arteaga Botello

    2006-01-01

    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.

  9. Das Altern als gesamtgesellschaftliche Herausforderung -Konsequenzen des Wandels von Altersideen und Lebensläufen für betriebliche Arbeitsgestaltung und die Sozialpolitik

    OpenAIRE

    Franiek, Corinna

    2008-01-01

    Die Relevanz der Themen Alter, Altern, sowie demographischer Wandel wurde gerade in jüngster Zeit deutlich. Die ARD widmete sich ab dem 21. April 2008 für eine Woche verstärkt dem Thema „Mehr Zeit zu Leben“ und zeigte Chancen einer alternden Gesellschaft auf. Am 14. Juli 2008 wurde in Halle feierlich die Leopoldina zur „Nationalen Akademie der Wissenschaften“ ernannt, welche sich auch dem Thema demographischer Wandel widmen will und zusammen mit „acatech“ einen Bericht über ?...

  10. Als.html">Indian Academy of Sciences - Special issues of journAls

    Indian Academy of Sciences (India)

    indian academy of sciences - special issues of journAls journAls | special issues of journAls | special issues of journAls sadhana pramana proceedings journal journal proceedings bulletin of materiAls science proceedings ...

  11. ELECTROREFLECTANCE OF THIN FILM Al-ZnS-Al SANDWICHES

    OpenAIRE

    Chabrier, G.; Moustaide, A.; Niquet, G.; Vernier, P.

    1983-01-01

    The electroreflectance (ER) spectra of thin ZnS films have been measured by applying a sinusoidal voltage to Al-ZnS-Al sandwiches. Reflectance variation with applied voltage have been analyzed with a lock-in amplifier. Odd (linear) components due to interfacial layers have been separated from even (quadratic) ones due to the whole film. Structural disorder, specific of thin films, might explain the large broadening of the extrema and make the low field approximation valid.

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

    OpenAIRE

    M. Góral; G. Moskal

    2012-01-01

    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 condu...

  13. Experimental and simulation investigations of tensile response of (Al2O3f/Al)w/2024Al composite

    International Nuclear Information System (INIS)

    Tensile response of a 2024Al alloy reinforced with Al2O3f/Al composite wires [(Al2O3f/Al)w/2024Al composite] has been investigated by both performing tensile tests and using the finite element method (FEM). Microstructure and tensile fracture surfaces of (Al2O3f/Al)w/2024Al composites were examined using optical microscope (OM) and scanning electron microscope (SEM), respectively. It is found that the longitudinal tensile response of (Al2O3f/Al)w/2024Al composite is nearly elastic up to failure. The longitudinal tensile strength of (Al2O3f/Al)w/2024Al composite reaches its fiber bundle strength and the longitudinal elastic modulus is consistent with that predicted using the rule of mixture. The contribution of matrix is negligible to the longitudinal tensile strength but not to the modulus of elasticity. Coating composite wires (CWs) with Ni can improve the interfacial bonding between the CWs and 2024Al alloy. Diffusion annealing can further improve the interfacial bonding. The transverse tensile strength is dependent strongly on the interfacial bonding between the CWs and 2024Al alloy. The stronger the interfacial bonding, the higher the transverse tensile strength. Following the diffusion annealing, ageing treatment can improve the transverse tensile strength of (Al2O3f/Al)w/2024Al sub>O3f/Al)w/2024Al composite to a higher level due to the increased strength of matrix 2024Al alloy. To reveal the fracture mode of (Al2O3f/Al)w/2024Al composite under transverse loading, the transverse tensile response of a model material, (Al2O3f/matrix1)w/matrix2 composite, whose microstructure is similar to that of the (Al2O3f/Al)w/2024Al composite, was analyzed using FEM. FEM results indicate that, under transverse loading, the stress distribution in the (Al2O3f/matrix1)w/matrix2 composite depends on the strength of matrix2. When matrix1 and matrix2 are both pure Al, failure initiates in matrix1. When matrix1 is pure Al and matrix2 is aged 2024Al alloy, however, failure initiates in matrix2 (2024Al). Therefore, for (Al2O3f/Al)w/2024Al composites with weak interfacial bonding between CWs and 2024Al matrix, cracks initiate at interfaces between the CWs and 2024Al matrix and propagate along the interfaces and then through 2024Al matrix, resulting in the global fracture. For (Al2O3f/Al)w/2024Al composite with strong interfacial bonding between CWs and 2024Al matrix, cracks initiate in either pure Al or 2024Al alloy and then propagate in both Al and 2024Al, resulting in the global fracture

  14. What happened to Sayf al-Rijal?

    OpenAIRE

    Sher Banu A.L. Khan

    2012-01-01

    Sayf al-Rijal is the least known Sheikh al-Islam, the highest religious appointee in the court of Aceh Dar al-Salam, in the seventeenth century. Yet, he replaced the renowned Sheikh Nur al-Din in 1643 and in turn was succeeded by another famous ulama Abd al- Ra’uf al-Sinkili in 1661. As of date, there is very little information on al-Rijal and his writings after he won the struggle against al-Raniri and was appointed as the Sheikh al-Islam by Sultanah SafiatuddinSyah in 1643. So, what happene...

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

    Science.gov (United States)

    Copland, Evan

    2004-01-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Karin Fischer

    2012-03-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-09-15

    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.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-06-15

    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.

  19. Das Informatik-Forum Stuttgart - mehr Dialog zwischen Theorie und Anwendung notwendig

    Science.gov (United States)

    Hieber, Ludwig

    Mit der Gründung des Informatik- Forum Stuttgart wird seit 1996 eine Plattform angeboten, die den Dialog zwischen der universitären Forschung, der Informatikausbildung und der IT-Wirtschaft in der Region Stuttgart intensivieren soll. In der Informatik hat sich eine Lücke zwischen Theorie und Anwendung entwickelt. Es ist nicht erkennbar, dass diese Lücke kleiner wird, eher das Gegenteil zeichnet sich ab. Verglichen mit anderen Branchen besteht die Gefahr, dass Anwender wesentlich später von Erkenntnissen aus der Forschung profitieren. Der entstandene Interaktionsstau zwischen Theorie und Anwendung der Informatik sollte abgebaut werden. An einigen Beispielen wird aufgezeigt, wo das besonders wichtig erscheint.

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

    Science.gov (United States)

    Noda, Kazuhiko; Miyahara, Keita; Watanabe, Yoshimi

    2008-02-01

    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.

  1. Als/matersci/materiAlsScience.html">Indian Academy of Sciences - Bulletin of MateriAls Science

    Indian Academy of Sciences (India)

    indian academy of sciences - bulletin of materiAls science recent advances in materiAls and processes proc. fifth annual general meeting of materiAls research society proc. sixth annual general meeting of materiAls research soceity india-japan seminar on new materiAls of the international unions of materiAls research societies presented at the india-japan seminar on computational mate ...

  2. On the Security of Liaw et al.'s Scheme

    CERN Document Server

    Awasthi, Amit K

    2008-01-01

    Recently, Liaw et al. proposed a remote user authentication scheme using smartcards. They claimed a number of features of their scheme, e.g. a dictionary of verification tables is not required to authenticate users; users can choose their password freely; mutual authentication is provided between the user and the remote system; the communication cost and the computational cost are very low; users can update their password after the registration phase; a session key agreed by the user and the remote system is generated in every session; and the nonce-based scheme which does not require a timestamp (to solve the serious time synchronization problem) etc. In this paper We show that Liaw et al.'s scheme does not stand with various security requirements and is completely insecure. Keywords: Authentication, Smartcards, Remote system, Attack.

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

    Directory of Open Access Journals (Sweden)

    Christian Berger

    2010-06-01

    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.

  4. Personalidad y tolerancia al dolor

    Directory of Open Access Journals (Sweden)

    JES\\u00DAS M.\\u00AA CARRILLO

    2005-01-01

    Full Text Available Se examina la relación de algunas variables de personalidad -EPQ-A (Eysenck y Eysenck, 1975, NEO-PI (McCrae y Costa, 1988 y STA -personalidad esquizotípica- y STB -personalidad límite-, de Claridge y Broks (1984, con la tolerancia al dolor experimental inducido mediante agua fría (cold pressor test, según el procedimiento de Staats, Heckmat y Staats (1998 en una muestra filtrada mediante un cuestionario sobre dolor crónico, dolores de cabeza, de espalda, artritis, síndrome de Raynaud, y personas bajo medicación. La tolerancia al dolor experimental se evaluó mediante el Umbral del dolor (tiempo en segundos desde la introducción de la mano en el agua hasta el primer informe de dolor, Mantenimiento del dolor (duración en segundos de la inmersión de la mano desde la aparición del umbral hasta su retirada y Tolerancia al dolor (duración total en segundos de la inmersión de la mano desde su introducción hasta su retirada. Un análisis correlacional, factorial y de regresión por pasos mostraron un efecto cruzado entre medidas de ansiedad (tolerancia negativa al dolor y psicoticismo, siendo psicoticismo junto con control emocional predictores de tolerancia positiva al dolor. En cuanto a psicoticismo, parece que son sus elementos de naturaleza paranoide y de "dureza" los que afectan a una percepción atenuada del dolor.

  5. Everyday Life with ALS: A Practical Guide

    Science.gov (United States)

    ... in this one. Back to top Resources MDA ALS Division The Muscular Dystrophy Association, one of the ... 572-1717. Back to top General Resources About ALS In addition, consult the MDA ALS Caregiver’s Guide, ...

  6. 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)

    Ahmad Syahid

    2014-03-01

    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

  7. Vormundschaftsrecht als Grundlage politischer Herrschaft

    Directory of Open Access Journals (Sweden)

    Arne Duncker

    2006-07-01

    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.

  8. Al-Qaeda Since 911

    OpenAIRE

    Brahimi, Alia

    2012-01-01

    Seconds after smiling at her local MP and shaking his hand, Roshonara Choudhry plunged a knife into his stomach. The attack on Stephen Timms in May 2010 was not the most high profile assault inspired by al- Qaeda, nor was it fatal. It did, however, offer a commentary on the changing nature of the terrorist threat since 9/11, al-Qaeda’s major impact on international relations as well as its major failure, and the intimate, perhaps inevitable, connection between the two.

  9. 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.)

  10. Production of Al nanocomposite reinforced by Fe-Al intermetallic, Al4C3 and nano-Al2O3 particles using wet milling in toluene

    International Nuclear Information System (INIS)

    Highlights: ? Production of Al nanocomposite reinforced by Fe-Al intermetallic, Al4C3 and nano-Al2O3 particles using wet milling in toluene. ? Production of Al4C3 particles from mechanochemical reaction of Al with PCA. ? Effect of second phase particles on sintering. - Abstract: Al matrix nanocomposites were produced by wet milling of Al and nano-alumina powders in a toluene media. X-ray diffraction patterns, inductively coupled plasma, carbon measurement analysis and scanning electron microscopy show that impurities introduced by decomposition of toluene and abrasion of balls and vials are uniformly dispersed in the Al matrix as Al4C3 and Fe-Al intermetallic particles. Though producing homogenous nanocomposites, these second phase particles seem to have a retarding effect on densification of nanocomposite powders.

  11. "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)

    Nürnberger, Frank

    2013-02-01

    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.

  12. VENEZUELA: OTRA ALTERNATIVA AL NEOLIBERALISMO

    Directory of Open Access Journals (Sweden)

    Huber Fern\\u00E1ndez Gonz\\u00E1lez

    2008-01-01

    con las fuerzas que se oponen al cambio y que aún no han sido derrotadas totalmente. Estas fuerzas, aunque están desprestigiadas política y socialmente, cuentan con poder económico, financiero, militar, con los medios de comunicación a su favor y con el apoyo incondicional de los Estados Unidos.

  13. Un controesempio al Modus Ponens

    Directory of Open Access Journals (Sweden)

    Vann McGee

    2010-11-01

    Full Text Available La traduzione dell’articolo è stata resa possibile grazie al consenso dell’autore e del Journal of Philosophy. Riferimenti originali: Vann McGee (1985: “A Counterexample to Modus Ponens”, Journal of Philosophy, Vol. 82, No. 9 (Sep. 1985, pp. 462-47. [N.d.T.

  14. Cathodic electrochemiluminescence at double barrier Al/Al2O3/Al/Al2O3 tunnel emission electrodes

    International Nuclear Information System (INIS)

    Double insulating barrier tunnel emission electrodes were fabricated by adding a new pure aluminum layer upon oxidized aluminum electrodes by vacuum evaporation and thermally oxidizing the new aluminum layer in air at room temperature. Resulting Al/Al2O3/Al/Al2O3 electrodes allow the use of various aluminum alloys in the electrode body necessary for hardness or shaping ability of the electrode while obtaining the luminescence properties of pure aluminum oxide. During electrical excitation of luminescent labels by cathodic hot electron injection into aqueous electrolyte solution, the background noise is mainly based on high-field-induced solid-state electroluminescence and F-center luminescence of the outer aluminum oxide film. The more defect states and/or impurity centers the outer oxide film contains, the higher is the background emission intensity. The present electrode fabrication method provides a considerable improvement in signal-to-noise ratio for time-resolved electrochemiluminescence (TR-ECL) measurements when the original native oxide film of the electrode body contains luminescence centers displaying long-lived luminescence. The excellent performance of the present electrodes is demonstrated by extremely low-level detection of Tb(III) chelates, luminol, Pt(II) coproporphyrin and Tb(III) labels in an immunometric immunoassay by time-resolved electrochemiluminescence

  15. Eine wasserdurchlässige Dampfbremse als Hygrodiode

    DEFF Research Database (Denmark)

    Sagelsdorff, Ralph; Rode, Carsten

    1997-01-01

    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.

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

    OpenAIRE

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

    1998-01-01

    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...

  17. 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)

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

    2013-01-01

    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. ????????????? ????? ????? ???????????? ??? ????????????? ????????????? ????- ? ??????????????????? ?????????? ? ???????? ?????????? ????????????????? ??????.

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

    Directory of Open Access Journals (Sweden)

    M. Góral

    2012-12-01

    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

  19. Beta decay of 24Al

    International Nuclear Information System (INIS)

    The ?+ decay of 24Al has been studied with a Ge(Li)-NaI(Tl) escape-suppression spectrometer. The number of 24Mg ? transitions observed following 24Al decay has been increased from 19 to 44. Definite new ?+ branches were observed to 24Mg levels at 105 76, 108 21, and 113 14 keV. An enhanced E2 transition from the 4+ 9301-keV level to the 2+ 7349-keV level was sought for and found. A probable 8439?7349 4+?2+ transition was also observed. The contribution of these new experimental results to an elucidation of the band structure of 24Mg is discussed

  20. Sui controesempi al Modus Ponens

    Directory of Open Access Journals (Sweden)

    Giorgio Sbardolini

    2010-11-01

    Full Text Available In McGee (1985 si presentano tre controesempi al modus ponens (MP, e si argomenta di come esistano restrizioni alla validità di questa regola deduttiva. Nel presente articolo, intendo ridiscutere questi tre controesempi a MP mostrando perché non colgono il bersaglio, e presentare altri casi in cui l'applicazione di MP non sembra efficace.In [McGee, 1985] si presentano 3 controesempi al modus ponens (MP, e si argomenta di come esistano restrizioni alla validità di questa regola deduttiva. Nel presente articolo, intendo ridiscutere questi 3 controesempi a MP mostrando perché non colgono il bersaglio, e presentare altri casi in cui l'applicazione di MP non sembra efficace.

  1. 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

  2. Wat als Rusland niet ratificeert?

    OpenAIRE

    Mm, Berk; Mgj, Elzen Den

    2012-01-01

    Ratificatie van het Kyoto Protocol (KP) door Rusland, noodzakelijk voor de inwerkingtreding van het Kyoto Protocol, is nog steeds onzeker. Dit rapport evalueert een aantal opties voor behoud van het KP in het geval Rusland niet (op afzienbare termijn) ratificeert. Het rapport laat zien dat de milieu-effectiviteit van sommige alternatieven beter is dan het huidige KP door de hoeveelheid surplus emissieruimte (hot air) die wordt vermeden als Rusland niet ratificeert. Teg...

  3. Wat als Rusland niet ratificeert?

    OpenAIRE

    Mm, Berk; Mgj, Elzen Den

    2007-01-01

    Ratificatie van het Kyoto Protocol (KP) door Rusland, noodzakelijk voor de inwerkingtreding van het Kyoto Protocol, is nog steeds onzeker. Dit rapport evalueert een aantal opties voor behoud van het KP in het geval Rusland niet (op afzienbare termijn) ratificeert. Het rapport laat zien dat de milieu-effectiviteit van sommige alternatieven beter is dan het huidige KP door de hoeveelheid surplus emissieruimte (hot air) die wordt vermeden als Rusland niet ratificeert. Tegelijke...

  4. Laser-driven performance of the Al/Al2O3/Al multi-layer flyer

    Science.gov (United States)

    Chen, Shaojie; Wu, Lizhi; Shen, Ruiqi; Ye, Yinghua; Hua, Tianli

    2013-12-01

    To assess the effect of the Al2O3 layer on the performance of a laser-driven flyer, the photonic Doppler velocimetry (PDV) and the polyvinylidene fluoride (PVDF) piezoelectric film were used. The experiment results show that because of the addition of Al2O3 insulation layer the velocity of the Al/Al2O3/Al multi-layer flyer decreased 4.8% in comparison with the Al single-layer flyer, but the impact stress increased 61.4%, up to 870 MPa at 248 mJ laser energy. Moreover, the planarity and the integrity of the flyer plate were improved.

  5. Laser-driven performance of the Al/Al2O3/Al multi-layer flyer

    International Nuclear Information System (INIS)

    To assess the effect of the Al2O3 layer on the performance of a laser-driven flyer, the photonic Doppler velocimetry (PDV) and the polyvinylidene fluoride (PVDF) piezoelectric film were used. The experiment results show that because of the addition of Al2O3 insulation layer the velocity of the Al/Al2O3/Al multi-layer flyer decreased 4.8% in comparison with the Al single-layer flyer, but the impact stress increased 61.4%, up to 870 MPa at 248 mJ laser energy. Moreover, the planarity and the integrity of the flyer plate were improved. (paper)

  6. AlN nanoparticle-reinforced nanocrystalline Al matrix composites: Fabrication and mechanical properties

    International Nuclear Information System (INIS)

    To improve the specific strength and stiffness of Al-based composites, AlN/Al nanoparticles were in-situ synthesized by arc plasma evaporation of Al in nitrogen atmosphere and consolidated by hot-pressing to fabricate AlN nanoparticle-reinforced nanocrystalline Al composites (0-39 vol.% AlN). Microstructure characterization shows that AlN nanoparticles homogeneously distribute in the matrix of Al nanocrystalline, which forms atomically bonded interfaces of AlN/Al. The hardness and the elastic modulus of the nanocomposite have been improved dramatically, up to 3.48 GPa and 142 GPa, respectively. Such improvement is believed to result from the grain refinement strengthening and the interface strengthening (load transfer) between the Al matrix and AlN nanoparticles

  7. Angles et grandeur d'Euclide à Kamal al-Din al-Farisi

    CERN Document Server

    Rashed, Roshdi

    2015-01-01

    This is the first comprehensive treatment of the history of the angle from Euclid to classical Arabic mathematics. The volume presents critically edited texts, with translations and commentaries, of Greek and Arabic philosophers and mathematicians including Euclid, Simplicius, al-Nayr?z?, Avicenna, Ibn al-Haytham, al-T?s?, al-Sh?r?z?, and al-F?ris?.

  8. Emerging mechanisms of molecular pathology in ALS.

    Science.gov (United States)

    Peters, Owen M; Ghasemi, Mehdi; Brown, Robert H

    2015-05-01

    Amyotrophic lateral sclerosis (ALS) is a devastating degenerative disease characterized by progressive loss of motor neurons in the motor cortex, brainstem, and spinal cord. Although defined as a motor disorder, ALS can arise concurrently with frontotemporal lobal dementia (FTLD). ALS begins focally but disseminates to cause paralysis and death. About 10% of ALS cases are caused by gene mutations, and more than 40 ALS-associated genes have been identified. While important questions about the biology of this disease remain unanswered, investigations of ALS genes have delineated pathogenic roles for (a) perturbations in protein stability and degradation, (b) altered homeostasis of critical RNA- and DNA-binding proteins, (c) impaired cytoskeleton function, and (d) non-neuronal cells as modifiers of the ALS phenotype. The rapidity of progress in ALS genetics and the subsequent acquisition of insights into the molecular biology of these genes provide grounds for optimism that meaningful therapies for ALS are attainable. PMID:25932674

  9. Jongerenwerk als werkplaats voor professionalisering

    Directory of Open Access Journals (Sweden)

    Judith Metz

    2012-03-01

    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.

  10. Alergia al semen / Semen allergy

    Scientific Electronic Library Online (English)

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

    2013-12-01

    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.

  11. Bioética frente al paciente moribundo

    Directory of Open Access Journals (Sweden)

    Laides Luna Vázquez

    2000-08-01

    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.

  12. Synthesis of AlON and MgAlON Ceramics and Their Chemical Corrosion Resistance

    OpenAIRE

    Wang, Xidong

    2001-01-01

    In view of the excellent mechanical, chemical and opticalproperties, AlON (Aluminum oxynitride) as well as MgAlON(Magnesium Aluminum oxynitride) have drawn the attention ofmaterials scientists in past decades. In this thesis,thermodynamic properties, synthesis and corrosion resistance tooxygen and slag of AlON and MgAlON ceramics have beeninvestigated. Gibbs energy of AlON and MgAlON with different compositionsand temperatures were estimatedby using thermodynamicquasi-parabola rule. Phase sta...

  13. Suicidio por salto al vacío

    Scientific Electronic Library Online (English)

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

    1995-05-01

    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%. 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%).

  14. Suicidio por salto al vacío

    Directory of Open Access Journals (Sweden)

    Braulio Ernesto P. Linares

    1995-05-01

    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%.

  15. Rethinking ALS: the FUS about TDP-43

    OpenAIRE

    Lagier-tourenne, Clotilde; Cleveland, Don W.

    2009-01-01

    Mutation in TDP-43, a DNA/RNA binding protein, causes an inherited form of Amyotrophic Lateral Sclerosis (ALS). Combination of its mislocalization in most incidences of sporadic ALS (as well as other neurodegenerative disorders) with discovery of ALS-causing mutations in FUS/TLS, another DNA/RNA binding protein, has initiated a paradigm shift in understanding ALS pathogenesis. TDP-43 and FUS/TLS have striking structural and functional similarities, implicating alterations in RNA processing as...

  16. Comparison of TiAlN, AlCrN, and AlCrN/TiAlN coatings for cutting-tool applications

    Science.gov (United States)

    Sampath Kumar, T.; Balasivanandha Prabu, S.; Manivasagam, Geetha; Padmanabhan, K. A.

    2014-08-01

    Monolayer and bilayer coatings of TiAlN, AlCrN, and AlCrN/TiAlN were deposited onto tungsten carbide inserts using the plasma enhanced physical vapor deposition process. The microstructures of the coatings were characterized using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The SEM micrographs revealed that the AlCrN and AlCrN/TiAlN coatings were uniform and highly dense and contained only a limited number of microvoids. The TiAlN coating was non-uniform and highly porous and contained more micro droplets. The hardness and scratch resistance of the specimens were measured using a nanoindentation tester and scratch tester, respectively. Different phases formed in the coatings were analyzed by X-ray diffraction (XRD). The AlCrN/TiAlN coating exhibited a higher hardness (32.75 GPa), a higher Young's modulus (561.97 GPa), and superior scratch resistance ( L CN = 46 N) compared to conventional coatings such as TiAlN, AlCrN, and TiN.

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

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Enchao, E-mail: ecpeng@semi.ac.cn [Key Lab of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083 (China); Wang, Xiaoliang [Key Lab of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083 (China); ISCAS-XJTU Joint Laboratory of Functional Materials and Devices for Informatics, P.O. Box 912, Beijing 100083 (China); Xiao, Hongling; Wang, Cuimei; Yin, Haibo; Chen, Hong; Feng, Chun; Jiang, Lijuan [Key Lab of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083 (China); Hou, Xun [ISCAS-XJTU Joint Laboratory of Functional Materials and Devices for Informatics, P.O. Box 912, Beijing 100083 (China); Wang, Zhanguo [Key Lab of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083 (China)

    2013-11-05

    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.

  18. 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

  19. Al-Al3Ni eutectic alloy and Al/WC(Ni) composite directionally solidified under microgravity and normal gravity

    Science.gov (United States)

    Luo, X.; Huang, Q.; Liu, B.; Zhang, X.; Li, Y.

    Directional solidification of Al-Al3 Ni eutectic alloy and Al/WC(Ni) composite were performed in the Multi-function Crystal Growing Furnace on board the unmanned Chinese Shenzhou II spacecraft and on the ground respectively. The specimens were investigated applying metallographic, SEM, XRD and image analysis techniques. The results show that, for the Al-Al3 Ni eutectic alloy, 1) microgravity condition is beneficial to eliminate solidification defects; 2) the Al3 Ni rods precipitated in the space sample are short and array somewhat random compared with that in the ground sample, which are longer and parallel to the growth direction; 3) different preferred orientations, Al(111) in the sample solidified under microgravity and Al3 Ni(200) in the sample solidified in 1g, were observed respectively; 4) the mean spacing between Al3 Ni rods obtained under microgravity comes near to that in normal gravity. Moreover, the inter-rod spacing distribution obtained in space is more convergent. In the Al/WC(Ni) composite, an obvious migration of WC(Ni) particles in Al matrix was observed in the space sample but not in the ground sample. It could be concluded that gravity condition had a strong influence on the solidification behavior of materials .

  20. Cyclic oxidation resistance of a reaction milled NiAl-AlN composite

    Science.gov (United States)

    Lowell, Carl E.; Barrett, Charles A.; Whittenberger, J. D.

    1990-01-01

    Based upon recent mechanical property tests a NiAl-AlN composite produced by cryomilling has very attractive high temperature strength. This paper focuses on the oxidation resistance of the NiAl-AlN composite at 1473 and 1573 K as compared to that of Ni-47Al-0.15Zr, one of the most oxidation resistant intermetallics. The results of cyclic oxidation tests show that the NiAl-AlN composite has excellent properties although not quite as good as those of Ni-47Al-0.15Zr. The onset of failure of the NiAl-AlN was unique in that it was not accompanied by a change in scale composition from alumina to less protective oxides. Failure in the composite appears to be related to the entrapment of AlN particles within the alumina scale.

  1. 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

  2. Biodigestor: una aproximación al diseño

    Directory of Open Access Journals (Sweden)

    Julio Mario Rodríguez Devis

    2011-11-01

    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.

  3. y los obstáculos al cambio

    Directory of Open Access Journals (Sweden)

    Cecilia Cadena Inostroza

    2004-01-01

    Full Text Available El trabajo analiza la administración pública a la luz de los cambios políticos. Parte del marco del institucionalismo histórico presentando a las instituciones como conjuntos de pautas de actuación que condicionan a los actores incluso más allá de su voluntad. Las transformaciones políticas en México no se han traducido en acciones que ofrezcan un trato igualitario a los ciudadanos frente al poder público con una más eficiente administración. Ésta se conformó históricamente como mecanismo clientelar que si bien permitió el funcionamiento del poder, limitó la eficiencia. Los cambios estructurales en el país son condición necesaria pero no suficiente para la transformación política democrática, en consecuencia ha de tomarse en cuenta la reforma de la administración pública.

  4. DE LA BIOPOLÍTICA AL CAMPO

    Directory of Open Access Journals (Sweden)

    Mauro Benente

    2009-01-01

    Full Text Available En el presente trabajo se realiza una breve aproximación a los conceptos de biopolítica y tanatopolítica. Para ello se trabajará, principalmente, con las obras de Michel Foucault, Roberto Esposito y Giorgio Agamben, intentando relevar tanto coincidencias como disidencias en la reflexión que los autores hacen sobre la temática. Luego de realizar una aproximación conceptual a la biopolítica, se mostrará que mientras para Foucault y para Espósito el surgimiento del fenómeno se da con la modernidad, para Agamben su origen es correlativo al origen mismo de la soberanía. Finalmente, y tras mostrar la coincidencia de la biopolítica con la tanatopolítica ¿para lo cual se profundizará en algunas reflexiones aportadas por Roberto Esposito- se abordará la problemática de los campos tal como lo hace Giorgio Agamben.

  5. teoría de respuesta al ítem

    Directory of Open Access Journals (Sweden)

    Mar\\u00EDa Ester Aguerri

    2007-01-01

    Full Text Available En el estudio del funcionamiento diferencial del ítem (DIF - differential item functioning la medición de su tamaño proporciona información relevante. Entre las medidas del DIF más utilizadas se encuentra el logaritmo de la razón común de las posibilidades de Mantel-Haenszel (Mantel-Haenszel Log Odds Ratio, MH-LOR. En el trabajo que se informa se analiza la similitud de los resultados al aplicar MH-LOR y una medida obtenida en el marco de la teoría de respuesta al ítem (TRI, a la que se denomina LOR-TRI, sobre datos reales y sobre datos simulados sin DIF. Los datos reales corresponden a una prueba de 20 ítem de razonamiento verbal, respondida por egresados del ciclo medio de enseñanza y por alumnos universitarios. Cada ítem presenta un par de palabras - base entre las cuales existe algún tipo de relación y cuatro opciones de pares de palabras entre las que se debe elegir aquel cuya relación sea la más cercana a la del par base. Para los datos simulados se consideraron las respuestas a un test de 20 ítem generadas según el modelo logístico de tres parámetros. Los grupos fueron elegidos de una población normal estándar con tamaño mues tral 1,000 y se efectuaron 100 repeticiones. Tan to para los datos reales como para los simulados el modelo logístico adecuado es el de tres parámetros, sin embargo se observó que el ajuste del modelo de Rasch condujo a resultados de LOR-TRI, similares a MH-LOR. Para los respectivos errores estándar se observó la misma particularidad en cuanto a la similitud, siendo ésta aún más destacada.

  6. Al?qat ?arakat Nashr al-Isl?m wa al-Tarb?yah al-Isl?miyyah f? ?ultanah Aceh

    Directory of Open Access Journals (Sweden)

    Eri Rosatria

    2014-03-01

    Full Text Available The emergence of such great 'ulama' in the Sultanate of Aceh, north of Sumatra, as Hamzah Fansuri (Hamzah al-Fansuri, Syamsuddin Sumatrani (Shams al-Din al-Sumatrani, Nuruddin Arraniri (Nur al-Din al-Raniri and Abdurrauf Singkel ('Abd al-Rauf al-Sinkili could lead one to pose an important questions. Why they emerged in the Sultanate of Aceh and not in other part of Nusantara. This study argues that that their emergence had closely to do with the fact that activity of Islamic learning was strongly supported by the Acehnese sultans.Copyright (c 2014 by SDI. All right reserved.DOI: 10.15408/sdi.v3i1.815

  7. Magnetism in bcc Fe-Al alloy

    International Nuclear Information System (INIS)

    The magnetic moment ?, hyperfine field Bhf and isomer shift IS at the Fe site in bcc Fe-Al alloys were calculated from first principle. Contrary to the belief that Al atoms reside in the iron lattice as magnetic holes, it was found that the local magnetic moment of Fe is decreased when Al is at a nearest neighbour site (NN), while it increases if Al is at a next-nearest neighbour site (NNN). Consequently, the average ? per Fe atom was found to be, initially, independent of Al content. Assuming a linear dependence of ?Fe on the number of Al atoms at NN and NNN sites, we calculated the average ?, which was found to agree with experimental results of cold worked alloys for disordered Fe-Al alloy. On the other hand, antiferromagnetic coupling appears in the CsCl ordered structures. The average Bhf was also calculated and compared to experimental data and the trends in the IS are considered. (orig.)

  8. 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.)

  9. Eutectic microstructures of Al-ThA13 and Al-UA14 alloys

    International Nuclear Information System (INIS)

    This paper deals on the microstructures of systems Al-ThAl3 and Al-UAL4, which are composed by a non faceted phase (aluminium) and an intermetallic phase (ThAl3 or UAL4) which is normally faceted phase. (C.M.)

  10. 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)

  11. Precipitation of (Al,Si)3Sc in an Al-Sc-Si alloy

    International Nuclear Information System (INIS)

    Three-dimensional atom probe has been applied to investigate the solubility of Si in Al3Sc in an Al-0.16Sc-0.05Si alloy. It was found that L12-structured Si-containing Al3Sc precipitates formed after the alloy was aged at 300 oC. Results of first-principles calculation indicated that Si atoms tend to substitute Al sites in Al3Sc, and thus the precipitates can be represented as (Al,Si)3Sc. The (Al,Si)3Sc was found to have a dramatic precipitation-strengthening effect in the cast alloy.

  12. Mechanochemically synthesized Fe3Al-Al2O3 nanocomposite

    International Nuclear Information System (INIS)

    Fe3Al-Al2O3 nanocomposite powder was successfully synthesized by mechanochemical route starting from Fe2O3 and Al powder mixture. The resulting nanocomposite powder was consolidated at 1400 deg. C for 1 h. The phase transformation and microstructural characterization during mechanochemical reaction and sintering were investigated by X-ray diffractometry (XRD) and scanning electron microscopy (SEM). The results showed that during ball milling the Fe2O3-Al combustion reaction directly produces the Fe3Al-Al2O3 nanocomposite. The consolidated Fe3Al-Al2O3 part had an ultrafine uniform structure without 'core-rim' feature consisting of an interconnected network of Fe3Al and Al2O3 phases

  13. Mechanochemical synthesis of (Fe,Ti)3Al-Al2O3 nanocomposite

    International Nuclear Information System (INIS)

    Formation mechanism of (Fe,Ti)3Al-Al2O3 nanocomposite prepared by mechanical alloying of Fe, Al and TiO2 with molar ratio of 6:7:3 was studied. The structural changes of powder particles during mechanical alloying were investigated by X-ray diffractometery. Morphology and microstructure of powder particles were characterized by scanning electron microscopy. It was found that during mechanical alloying Al first reacts with TiO2 leading to the gradual formation of crystalline Ti and amorphous Al2O3 phases. In the second stage Ti and remaining Al diffuse into the Fe lattice and as a result a Fe(Al,Ti) solid solution develops. This structure transformed to (Fe,Ti)3Al intermetallic compound at longer milling times. Heat treatment of this structure led to the crystallization of Al2O3 and ordering of (Fe,Ti)3Al phases.

  14. Atom probe analysis of AlN interlayers in AlGaN/AlN/GaN heterostructures

    International Nuclear Information System (INIS)

    Atom probe tomography was used to characterize AlN interlayers in AlGaN/AlN/GaN heterostructures grown by plasma-assisted molecular beam epitaxy (PAMBE), NH3-based molecular beam epitaxy (NH3-MBE), and metal-organic chemical vapor deposition (MOCVD). The PAMBE-grown AlN interlayer had the highest purity, with nearly 100% of group-III sites occupied by Al. The group-III site concentrations of Al for interlayers grown by NH3-MBE and MOCVD were ?85% and ?47%, respectively. Hall measurements were performed to determine the two-dimensional electron gas mobility and sheet concentration. Sheet concentrations were ?25%–45% higher with molecular beam epitaxy than with MOCVD, and these results matched well with atom probe data.

  15. Atom probe analysis of AlN interlayers in AlGaN/AlN/GaN heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Mazumder, Baishakhi; Kaun, Stephen W.; Speck, James S. [Materials Department, University of California, Santa Barbara, California 93106 (United States); Lu, Jing; Keller, Stacia; Mishra, Umesh K. [Electrical and Computer Engineering Department, University of California, Santa Barbara, California 93106 (United States)

    2013-03-18

    Atom probe tomography was used to characterize AlN interlayers in AlGaN/AlN/GaN heterostructures grown by plasma-assisted molecular beam epitaxy (PAMBE), NH{sub 3}-based molecular beam epitaxy (NH{sub 3}-MBE), and metal-organic chemical vapor deposition (MOCVD). The PAMBE-grown AlN interlayer had the highest purity, with nearly 100% of group-III sites occupied by Al. The group-III site concentrations of Al for interlayers grown by NH{sub 3}-MBE and MOCVD were {approx}85% and {approx}47%, respectively. Hall measurements were performed to determine the two-dimensional electron gas mobility and sheet concentration. Sheet concentrations were {approx}25%-45% higher with molecular beam epitaxy than with MOCVD, and these results matched well with atom probe data.

  16. Nanoindentation hardness, texture and microstructure of ?-Al2O3 and ?-Al2O3 coatings

    International Nuclear Information System (INIS)

    Nanoidentation responses of Al2O3 coatings obtained using chemical vapour deposition on cemented carbides were studied and related to the Al2O3 modification and microstructure. Five different Al2O3 layers were studied: (i) ?-Al2O3, (ii) ?-Al2O3, obtained through the ? ? ? phase transformation, (iii) as-grown ?-Al2O3 with (101-bar 2) texture, (iv) as-grown ?-Al2O3 with (101-bar 4) texture and (v) as-grown ?-Al2O3 with (0001) texture. All the Al2O3 coatings were deposited to a thickness of at least 6 ?m onto identical WC - 6 wt.% Co cemented carbide substrates. Nanoindentation was performed on taper-section specimens. The microstructure, phase and texture were elucidated by using transmission electron microscopy, scanning electron microscopy and X-ray diffraction. Nanoindentation responses of the as-grown, textured ?-Al2O3 coatings were compared with ?-Al2O3 and ?-Al2O3 formed as a result of the ? ? ? phase transformation. The as-grown, textured ?-Al2O3 layers exhibited clearly a higher hardness and Young's modulus than the ?-Al2O3 and the ?-Al2O3 layers formed as a result of the phase transformation. Only slight differences iy slight differences in hardness and modulus could be detected between the (101-bar 2), (101-bar 4) and (0001) textured ?-Al2O3 films. Among these the (101-bar 2) textured ?-Al2O3 coating exhibited the lowest hardness and modulus. Opposite to earlier reports, the present investigation clearly showed that ?-Al2O3 exhibited both the lowest hardness and Young's modulus as compared with the other studied coatings. It is emphasised that the earlier nanoindentation investigations that were intended to deal with ?-Al2O3 were in fact performed on transformed ?-Al2O3

  17. Novel TARDBP mutations in Nordic ALS patients

    DEFF Research Database (Denmark)

    Chiang, Huei-Hsin; Andersen, Peter M

    2012-01-01

    Amyotrophic lateral sclerosis (ALS) is a neurodegenerative syndrome primarily affecting the upper and lower motor neurons. A characteristic neuropathological finding in ALS patients is neuronal inclusions positive for TAR DNA-binding protein 43 (TDP-43). Subsequently, mutations in the gene encoding TDP-43, TARDBP, proved to be involved in the development of ALS. We thus sequenced TARDBP in 177 Nordic ALS patients and found two previously reported (p.A90V and p.S379P) and two novel (p.G357R and p.R361T) missense variations in three familial ALS patients. The p.A90V and p.G357R variations were detected in the same patient and p.R361T was present in a family with both ALS and frontotemporal dementia-ALS. None of the missense variations were present in 200 neurologically healthy controls. However, p.A90V has also been reported in healthy individuals by others. Thus, the data suggest that these variations are rare and p.G357R, p.R361T and p.S379P are likely pathogenic but further functional characterization is needed to prove their pathogenicity. The mutation frequency in TARDBP in Nordic ALS patients was 1.7%. The ALS cohort was highly selected for a positive family history suggesting that mutations in TARDBP generally are a rare cause of ALS in Nordic countries.

  18. Insostenibilidad: aproximación al conflicto socioecológico

    Scientific Electronic Library Online (English)

    Josep, Lobera.

    2008-12-01

    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 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.

  19. Electrical stress effect on Josephson tunneling through ultrathin AlOx barrier in Nb/Al/AlOx/Nb junctions

    OpenAIRE

    Tolpygo, Sergey K.; Amparo, Denis

    2008-01-01

    The effect of dc electrical stress and breakdown on Josephson and quasiparticle tunneling in Nb/Al/AlOx/Nb junctions with ultrathin AlOx barriers typical for applications in superconductor digital electronics has been investigated. The junctions' conductance at room temperature and current-voltage (I-V) characteristics at 4.2 K have been measured after the consecutive stressing of the tunnel barrier at room temperature. Electrical stress was applied using current ramps with ...

  20. The effect of thermal annealing on the properties of Al-AlOx-Al single electron tunneling transistors

    OpenAIRE

    Scherer, H.; Weimann, Th.; A. B. Zorin; Niemeyer, J

    2001-01-01

    The effect of thermal annealing on the properties of Al-AlOx-Al single electron tunneling transistors is reported. After treatment of the devices by annealing processes in forming gas atmosphere at different temperatures and for different times, distinct and reproducible changes of their resistance and capacitance values were found. According to the temperature regime, we observed different behaviors as regards the resistance changes, namely the tendency to decrease the resi...

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

    Directory of Open Access Journals (Sweden)

    Zhang Jing

    2010-02-01

    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.

  2. interna y al diálogo transcultural

    Directory of Open Access Journals (Sweden)

    Silvia Monroy \\u00C1lvarez

    2007-01-01

    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.

  3. Respuestas al neoliberalismo en Argentina

    Scientific Electronic Library Online (English)

    Patricia, Davolos; Laura, Perelman.

    Full Text Available Hacia finales de la década pasada comienza a cobrar dinamismo la protesta social en Argentina como respuesta a la crisis resultante de las políticas neoliberales que dominaron la escena nacional en los noventa. En ese contexto, grupos de trabajadores ocupan empresas en riesgo de cerrar sus puertas, [...] organizándose para operarlas en forma autogestionaria. Aquí se estudian las características del mercado de trabajo, así como las tradiciones y los recursos que permitieron a los trabajadores llevar adelante este tipo de acciones, delineando distintas trayectorias que otorgaron inteligibilidad al fenómeno analizado. Abstract in english Towards the end of the past decade, social protests in Argentina started to gain strength and become more dynamic in response to the crisis that ensued from the neoliberal policies that were predominant in said country during the 1990's. In such framework, workers' groups started to take over compan [...] ies who were at risk of shutting down, thus organizing themselves to manage and operate said companies under a self-rule scheme. This paper reviews the labor market characteristics as well as the traditions and resources that enabled workers to undertake and advance such kind of actions, through an outline of various courses of action that provided intelligibility to the situation and events being reviewed.

  4. DOLOR LUMBAR RELACIONADO AL EMBARAZO

    Scientific Electronic Library Online (English)

    Milan, Munjin L; Francisco, llabaca G; Juan, Rojas B.

    Full Text Available El dolor lumbar ha sido considerado la complicación más frecuente del embarazo, a pesar de ello, su etiopatogenia aún es controvertida. La prevalencia en nuestro medio es desconocida, y el tratamiento se basa para muchos médicos solo en el reposo, medida que no tiene sustento en la literatura. En es [...] ta revisión, nos centramos en la historia clínica, terminología, mecanismos fisiológicos teóricamente implicados, factores de riesgo, prevalencia y proponemos un enfoque de tratamiento del dolor lumbar asociado al embarazo Abstract in english The low back pain has been considered the most frequent complication of pregnancy, despite this fact, etiology and pathophysiology is unclear at present time. The prevalence in our country is unknown, and the treatment is based on in rest-periods for the most physicians, instead literature rationali [...] ty. In our research, based in the literature, we focus in the history, terminology, theoretical physiological mechanism, risk factors, prevalence and we propose pathways for treatment of pregnancy-related low back pain

  5. Na3Al(AsO42

    Directory of Open Access Journals (Sweden)

    Noura Fakhar Bourguiba

    2013-02-01

    Full Text Available The structure of the title compound trisodium aluminium bis(arsenate, Na3Al(AsO42, is built up from AlO4 and AsO4 corner-sharing tetrahedra, forming an undulating two-dimensional framework parallel to (100. The layers are constituted of large Al6As6O36 rings made up from six AlO4 and AsO4 tetrahedra in which two sodium cations are situated, the third sodium cation being located in the interlayer space. The structural relationships between the title compound and Na3Fe(PO42, NaAlCo(PO42 and Al5Co3(PO48 are discussed.

  6. Aproximación crítica al Gobierno de Alvaro Uribe

    Directory of Open Access Journals (Sweden)

    RICARDO SANCHEZ

    2003-06-01

    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.

  7. 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)

  8. [Nordosteuropa als Geschichtsregion] / Hans-Jürgen Bömelburg

    Index Scriptorium Estoniae

    Bömelburg, Hans-Jürgen

    2009-01-01

    Arvustus: Nordosteuropa als Geschichtsregion : Beiträge des III. Internationalen Symposiums zur deutschen Kultur und Geschichte im europäischen Nordosten vom 20.-22. September 2001 in Tallinn (Estland)

  9. 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.

  10. Respuesta inmune adaptativa al rotavirus

    Directory of Open Access Journals (Sweden)

    Manuel A. Franco

    2004-03-01

    Full Text Available

    El rotavirus (RV es un importante patógeno humano y el estudio de la respuesta inmune específica de éste en humanos, es un buen modelo para caracterizar la respuesta inmune de la mucosa intestinal (1. Nuestros estudios han tenido como objetivo la caracterización fenotípica y funcional de las células T y B específicas de RV con énfasis importante en la expresión de marcadores de migración intestinal. Estas células son estudiadas en muestras de sangre periférica de niños y adultos recientemente infectados con RV. Los análisis se hicieron por citometría de flujo y ELISPOT. Estudio de células T: los adultos sanos presentan bajas frecuencias circulantes tanto de LT CD4+, como de LT CD8+ específicos de RV que secretan INF_ .

    Significativamente mayores porcentajes de éstas células se detectaron en adultos sintomáticos infectados por RV. Sin embargo, las frecuencias de LT específicos de RV en todos los grupos de estudio fueron muy bajas comparadas con las observadas para otros patógenos.

    Sorprendentemente, en niños sintomáticos infectados por RV se detectaron bajas frecuencias de LT CD8+ circulantes específicos de RV secretando INF-g y muy pocos o ningún LT CD4+ secretando INF-g o LT CD4+ y CD8+ al secretar IL-13 o IL4 (2,3. Esto sugiere que el RV es un inductor relativamente pobre de células T de memoria secretando estas citoquinas. Los LT circulantes CD4+ , INF-g.+ específicos de RV presentes en adultos sanos, expresan en su mayoría el receptor de migración intestinal a4b7(3.

    Estudio de las células B (3,4: las células vírgenes circulantes CD19+, IgD+ y de memoria CD19+, IgDespecíficas de RV se identifican por citometría de flujo por la coexpresión de marcadores de superficie y de Ig de membrana específica del virus, con la ayuda de un antígeno viral acoplado a la proteína de fluorescencia verde (GFP. Las CSA se caracterizan funcionalmente por ELISPOT y fenotípicamente por citometría de flujo. Durante la fase aguda de infección en niños, los LB IgD- circulantes específicos de RV son predominantemente células grandes CD38alto, CD27alto, CD138+/-, CCR6-, a4b7 +, CCR9+, CCR10+, CLA-, L-Selectina int/- y sIgM+, sIgG-, sIgA+/ - Este fenotipo muy probablemente corresponde a CSA y plasmablastos con capacidad de migrar al intestino.

    Durante la convalescencia, el fenotipo cambia a células pequeñas y grandes CD38int/-, CD27int/-, CCR6+, a4b7+/-, CCR9+/- y CCR10-, muy probablemente representando células de memoria, algunas con capacidad de migrar al intestino y otras con capacidad de permanecer en la circulaci

  11. Interdiffusion in U 3Si-Al, U 3Si 2-Al, and USi-Al dispersion fuels during irradiation

    Science.gov (United States)

    Kim, Yeon Soo; Hofman, Gerard L.

    2011-03-01

    Uranium-silicide compound fuel dispersion in an Al matrix is used in research and test reactors worldwide. Interaction layer (IL) growth between fuel particles and the matrix is one of performance issues. The interaction layer growth data for U 3Si, U 3Si 2 and USi dispersions in Al were obtained from both out-of-pile and in-pile tests. The IL is dominantly U(AlSi) 3 from out-of-pile tests, but its (Al + Si)/U ratio from in-pile tests is higher than the out-of-pile data, because of amorphous behavior of the ILs. IL growth correlations were developed for U 3Si-Al and U 3Si 2-Al. The IL growth rates were dependent on the U/Si ratio of the fuel compounds. During irradiation, however, the IL growth rates did not decrease with the decreasing U/Si ratio by fission. It is reasoned that transition metal fission products in the IL compensate the loss of U atoms by providing chemical potential for Al diffusion and volume expansion by solid swelling and gas bubble swelling. The addition of Mo in U 3Si 2 reduces the IL growth rate, which is similar to that of UMo alloy dispersion in a silicon-added Al matrix.

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

    OpenAIRE

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

    2009-01-01

    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...

  13. n-type conductivity control of AlGaN with high Al mole fraction

    Energy Technology Data Exchange (ETDEWEB)

    Katsuno, Takuya; Liu, Yuhuai; Miyake, Hideto; Hiramatsu, Kazumasa [Department of Electrical and Electronic Engineering, Faculty of Engineering, Mie University, 1577 Kurima machiya, Tsu, Mie 514-8507 (Japan); Li, Dabing [Satellite Venture Business Laboratory, Mie University, 1577 Kurima machiya, Tsu, Mie 514-8507 (Japan); Shibata, Tomohiko; Tanaka, Mitsuhiro [NGK Insulators, Ltd., 2-56 Suda-cho, Mizuho-ku, Nagoya, 467-8530 (Japan)

    2006-06-15

    Silicon doped Al{sub x}Ga{sub 1-x}N with high Al mole fraction was grown using epitaxial AlN as a underlying layer by low-pressure metalorganic vapor phase epitaxy. n-type conductivity control of high quality Si-doped Al{sub x}Ga{sub 1-x}N was achieved successfully. Structural, electrical and optical properties were investigated for various Al mole fractions, flow rates of silicon, and Al{sub x}Ga{sub 1-x}N thickness, respectively. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  14. Observation of triatomic species with conflicting aromaticity: AlSi2- and AlGe2-.

    Science.gov (United States)

    Zubarev, Dmitry Yu; Boldyrev, Alexander I; Li, Xi; Wang, Lai-Sheng

    2006-05-25

    We created mixed triatomic clusters, AlCGe(-), AlSi(2)(-), and AlGe(2)(-), and studied their electronic structure and chemical bonding using photoelectron spectroscopy and ab initio calculations. Excellent agreement between theoretical and experimental photoelectron spectra confirmed the predicted global minimum structures for these species. Chemical bonding analysis revealed that the AlSi(2)(-) and AlGe(2)(-) anions can be described as species with conflicting (sigma-antiaromatic and pi-aromatic) aromaticity. The AlCGe(-) anion represents an interesting example of chemical species which is between classical and aromatic. PMID:16706418

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

    OpenAIRE

    Klan?nik G.; Medved J.

    2011-01-01

    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...

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

    Science.gov (United States)

    Nowacki, Jerzy; Moraniec, Kacper

    2015-01-01

    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

  17. Preparation and Thermoelectric Properties of YbAl3 Thermoelectric Materials with Excessive Al

    Science.gov (United States)

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

    2015-06-01

    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.

  18. De las fuentes al público

    Scientific Electronic Library Online (English)

    Lisbeth, Fog.

    2002-02-01

    Full Text Available 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.

  19. Durability Assessment of TiAl Alloys

    Science.gov (United States)

    Draper, Susan L.; Lerch, Bradley A.

    2008-01-01

    The durability of TiAl is a prime concern for the implementation of TiAl into aerospace engines. Two durability issues, the effect of high temperature exposure on mechanical properties and impact resistance, have been investigated and the results are summarized in this paper. Exposure to elevated temperatures has been shown to be detrimental to the room temperature ductility of gamma alloys with the most likely mechanisms being the ingress of interstitials from the surface. Fluorine ion implantation has been shown to improve the oxidation resistance of gamma alloys, and ideally it could also improve the environmental embrittlement of high Nb content TiAl alloys. The effect of F ion implantation on the surface oxidation and embrittlement of a third generation, high Nb content TiAl alloy (Ti-45Al-5Nb-B-C) were investigated. Additionally, the ballistic impact resistance of a variety of gamma alloys, including Ti-48Al-2Cr- 2Nb, Ti-47Al-2Cr-2Nb, ABB-2, ABB-23, NCG359E, 95A and Ti-45Al-5Nb-B-C was accessed. Differences in the ballistic impact properties of the various alloys will be discussed, particularly with respect to their manufacturing process, microstructure, and tensile properties.

  20. Quantitatively Probing the Al Distribution in Zeolites

    Energy Technology Data Exchange (ETDEWEB)

    Vjunov, Aleksei; Fulton, John L.; Huthwelker, Thomas; Pin, Sonia; Mei, Donghai; Schenter, Gregory K.; Govind, Niranjan; Camaioni, Donald M.; Hu, Jian Z.; Lercher, Johannes A.

    2014-06-11

    The degree of substitution of Si4+ by Al3+ in the oxygen-terminated tetrahedra (Al T-sites) of zeolites determines the concentration of ion-exchange and Brønsted acid sites. As the location of the tetrahedra and the associated subtle variations in bond angles influence the acid strength, quantitative information about Al T-sites in the framework is critical to rationalize catalytic properties and to design new catalysts. A quantitative analysis is reported that uses a combination of extended X-ray absorption fine structure (EXAFS) analysis and 27Al MAS NMR spectroscopy supported by DFT-based molecular dynamics simulations. To discriminate individual Al atoms, sets of ab initio EXAFS spectra for various T-sites are generated from DFT-based molecular dynamics simulations allowing quantitative treatment of the EXAFS single- and multiple-photoelectron scattering processes out to 3-4 atom shells surrounding the Al absorption center. It is observed that identical zeolite types show dramatically different Al-distributions. A preference of Al for T-sites that are part of one or more 4-member rings in the framework over those T-sites that are part of only 5- and 6-member rings in the HBEA150 sample has been determined from a combination of these methods. This work was supported by the U. S. Department of Energy (DOE), Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences.

  1. Diana Al-Hadid: Identity and Heritage

    Science.gov (United States)

    Jungerberg, Tom; Smith, Anna; Borsh, Colleen

    2012-01-01

    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…

  2. Studies on SiC(p) reinforced Al-Al sub 3 Ni eutectic matrix composites

    International Nuclear Information System (INIS)

    An investigation on processing of Al-5.69wt% Ni eutectic with SiC particulate composites is reported. The intermetallic composites are prepared by elemental powder metallurgy route and sintered at two different temperatures, i.e., 600 degree C and 620 degree C. Results show that the metal matrix was Al-Al sub 3 Ni eutectic. The phase analysis by XRD identified the presence of Al sub 3 Ni and Al as dominant phases together with silicon and Al sub 4 C sub 3 phase as minor phases. The Al sub 4 C sub 3 and Si phases are formed during sintering due to SiC-Al interface reaction. SEM micrographs also reveal the formation of microvoid surrounding the SiC particle

  3. The wobbler mouse, an ALS animal model

    DEFF Research Database (Denmark)

    Moser, Jakob Maximilian; Bigini, Paolo

    2013-01-01

    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

  4. Atomic structure of FeAl?001?

    Science.gov (United States)

    Wang, C. P.; Jona, F.; Gleason, N. R.; Strongin, D. R.; Marcus, P. M.

    1993-12-01

    The atomic structure of a clean {001} surface of the ordered binary alloy FeAl with 46 at% Al (lattice parameter 2.904 Å) has been determined by low-energy electron diffraction analysis. The bulk structure is of the CsCl-type. The top surface plane is shown to be an Al layer, with an Fe plane for the second layer. The first interlayer spacing (between Al and Fe) is found to be contracted by 14.6%, while the second interlayer spacing (between Fe and Al) is found to be expanded by 4%. A sputter-cleaned but not annealed surface of this alloy is found to have ordered regions of predominantly bcc Fe{001}.

  5. Half-life of 26Al

    International Nuclear Information System (INIS)

    We have measured the half-life of 26Al because data on 21Ne production rates in meteorites has indicated that the half-life may have been too low by 30--40 %. We produced 24Al using the 26Mg(p,n)26Al reaction on thick natural Mg, the yield being calculated from cross section data. The activity of two such samples was measured with a Ge(Li) detector and the calculated half-life is t/sub 1/2/ = (7.8 +- 0.5) x 105 years, in agreement with the accepted half-life of 26Al:t/sub 1/2/ = (7.16 +- 0.32) x 105 years. Therefore, another explanation must be found for the anomalous 21Ne production rate based on 26Al ages in meteorites

  6. NiAl alloys for structural uses

    Science.gov (United States)

    Koss, D. A.

    1991-01-01

    Alloys based on the intermetallic compound NiAl are of technological interest as high temperature structural alloys. These alloys possess a relatively low density, high melting temperature, good thermal conductivity, and (usually) good oxidation resistance. However, NiAl and NiAl-base alloys suffer from poor fracture resistance at low temperatures as well as inadequate creep strength at elevated temperatures. This research program explored macroalloying additions to NiAl-base alloys in order to identify possible alloying and processing routes which promote both low temperature fracture toughness and high temperature strength. Initial results from the study examined the additions of Fe, Co, and Hf on the microstructure, deformation, and fracture resistance of NiAl-based alloys. Of significance were the observations that the presence of the gamma-prime phase, based on Ni3Al, could enhance the fracture resistance if the gamma-prime were present as a continuous grain boundary film or 'necklace'; and the Ni-35Al-20Fe alloy was ductile in ribbon form despite a microstructure consisting solely of the B2 beta phase based on NiAl. The ductility inherent in the Ni-35Al-20Fe alloy was explored further in subsequent studies. Those results confirm the presence of ductility in the Ni-35Al-20Fe alloy after rapid cooling from 750 - 1000 C. However exposure at 550 C caused embrittlement; this was associated with an age-hardening reaction caused by the formation of Fe-rich precipitates. In contrast, to the Ni-35Al-20Fe alloy, exploratory research indicated that compositions in the range of Ni-35Al-12Fe retain the ordered B2 structure of NiAl, are ductile, and do not age-harden or embrittle after thermal exposure. Thus, our recent efforts have focused on the behavior of the Ni-35Al-12Fe alloy. A second parallel effort initiated in this program was to use an alternate processing technique, mechanical alloying, to improve the properties of NiAl-alloys. Mechanical alloying in the conventional sense requires ductile powder particles which, through a cold welding and fracture process, can be dispersion strengthened by submicron-sized oxide particles. Using both the Ni-35Al-Fe alloys to contain approx. 1 v/o Y2O3. Preliminary results indicate that mechanically alloyed and extruded NiAl-Fe + Y2O3 alloys when heat treated to a grain-coarsened condition, exhibit improved creep resistance at 1000 C when compared to NiAl; oxidation resistance comparable to NiAl; and fracture toughness values a factor of three better than NiAl. As a result of the research initiated on this NASA program, a subsequent project with support from Inco Alloys International is underway.

  7. Production of high-purity 26Al

    International Nuclear Information System (INIS)

    26Al is a positron emitting radioisotope of aluminium and has a half-life of 7.16x105y. In addition to annihilation ?-rays of 511 keV, there are three high energy ?-rays 1129 (2.4%), 1809 (99.73%) and 2938 (0.27%) keV. 26Al is the only radioisotope of aluminium available for radiochemical applications, the half-lives of the other aluminium isotopes are seconds and minutes. The usage of 26Al is very important in the investigations of the metabolism of Al in human body (for example in Alzheimer disease studies) or as a tracer in radiochemical studies. But 26Al is such a long-lived isotope that the task of producing it in tangible amounts is a very difficult one. (author). 2 refs

  8. Density and atomic volume in liquid Al-Fe and Al-Ni binary alloys

    Energy Technology Data Exchange (ETDEWEB)

    Plevachuk, Yu. [Ivan Franko National Univ., Lviv (Ukraine). Dept. of Metal Physics; Egry, I.; Brillo, J.; Holland-Moritz, D. [Deutsches Zentrum fuer Luft- und Raumfahrt, Koeln (Germany). Inst. fuer Raumsimulation; Kaban, I. [Chemnitz Univ. of Technolgy (Germany). Inst. of Physics

    2007-02-15

    The density of liquid Al-Fe and Al-Ni binary alloys have been determined over a wide temperature range by a noncontact technique combining electromagnetic levitation and optical dilatometry. The temperature and composition dependences of the density are analysed. A negative excess volume correlates with the negative enthalpy of mixing, compound forming ability and chemical short-range ordering in liquid Al-Fe and Al-Ni alloys. (orig.)

  9. Micromechanisms of fracture and fatigue in Ti3Al based and TiAl based intermetallics

    OpenAIRE

    James, A.; Chave, R.; Hippsley, C.; Bowen, P.

    1993-01-01

    Micromechanisms of fracture and fatigue crack growth resistance in specific Ti3Al based and TiAl based intermetallics are reviewed. Effects of test temprature, environment and microstructure on crack growth resistance are considered in detail for several Ti3Al and TiAl based intermetallic systems under development. The implications of these studies for the structural reliability of these materials is also addressed briefly.

  10. Thermal stability of TiAlN and nanocomposite TiAlSiN thin films.

    Science.gov (United States)

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

    2009-02-01

    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

  11. AL(0) in municipal waste incinerator ash

    Science.gov (United States)

    Stipp, S. L.; Ronsbo, J. G.; Zunic, T. B.; Christensen, T. H.

    2003-04-01

    Disposal of municipal waste is a challenge to society. Waste volume is substantially decreased by incineration but residual ash usually contains a number of toxic components which must be immobilised to insure environmental protection. One element, chromium, is mobile and toxic in its oxidised state as Cr(VI) but it can be reduced to Cr(III) and immobilised. Reduction can be promoted by ash treatment with Fe(0) or Fe(II), but recent evidence shows that at least some Cr(VI) is reduced spontaneously in the ash. Aspects of ash behaviour suggest metallic aluminium as the reducing agent, but no direct evidence of Al(0) has been found until now. We examined filter ash from an energy-producing, municipal-waste incinerator (Vest-forbrænding) near Copenhagen. X-ray diffraction (XRD) identified expected salts of Na, K and Ca such as halite, sylvite, calcite, anhydrite and gypsum as well as quartz, feldspar and some hematite. Wave-dispersive electron microprobe produced elemen-tal maps of the ash; Al-rich areas were analysed quantitatively by comparison with standards. We identified metallic Al particles, averaging 50 to 100 micrometers in di-ameter, often with a fractured, glassy border of aluminum oxide. The particles were porous, explaining fast Cr(VI) reduction and they contained thin exsolution lamellae of Al-alloys of Pb and Cu or Mn, Fe and Ag, which provide clues of the Al(0) origin in the waste. Sometimes Al(0) occurred inside glassy globes of Al2O3. Time-of-flight secondary ion mass spectroscopy (TOF-SIMS) and X-ray photoelectron spectroscopy (XPS) proved that surface Al concentrations on ash particles were below detection, confirming reactivity of the Al(0) bulk. The persistence of reduced Al through the highly oxidising combustion procedure comes as a surprise and is a benefit in the immobilisation of Cr(VI) from municipal-waste incineration residues.

  12. Tribological properties of Al6061-Al2O3 nanocomposite prepared by milling and hot pressing

    International Nuclear Information System (INIS)

    Tribological properties of bulk Al6061-Al2O3 nanocomposite prepared by mechanical milling and hot pressing were investigated. Al6061 chips were milled for 30 h to achieve a homogenous nanostructured powder. A 3 vol.% Al2O3 nanoparticles (?30 nm) were added to the Al6061 after 15 and 30 h from the beginning of milling. The milling times with Al2O3 in these two samples were then 15 h and 30 min, respectively. Additionally, 3 vol.% Al2O3 (1 ?m and 60 ?m) was added to the Al6061 after 15 h of milling; where, the micron size Al2O3 in these two samples, was milled 15 h with the matrix. Hot pressing of milled samples was executed at 400 oC under 128 MPa pressure in a uniaxial die. The hot pressed samples were characterized by micro-hardness test, bulk density measurements, pin on disc wear test, and finally scanning electron microscopy observations. Fifteen hour-milled nanocomposite with nanoscale Al2O3, showed improvement in wear resistance and bulk density compared with that of 30 min-milled nanocomposites due to better dispersion of Al2O3 nanoparticles, improved surface quality of nanocomposite particles before pressing and more grain refinement of Al matrix. Moreover, increasing the reinforcement size increased the wear rate because of reduction in relative density, hardness and inter-particle spacing.

  13. 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)

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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)

  15. Al?Al 3Ni eutectic alloy and AL/WC(NI) composite directionally solidified under microgravity and normal gravity

    Science.gov (United States)

    Luo, X.-H.; Huang, Q.; Liu, B.-D.; Zhang, X.-M.; Li, Y.-Y.

    2003-07-01

    Directional solidification of Al?Al 3Ni eutectic alloy and Al/WC(Ni) composite were performed in the Multi-functional Crystal Growing Furnace on board the unmanned Chinese Shenzhou II spacecraft and on the ground respectively. The microstructures of the samples were investigated applying metallographic, SEM, XRD and image analysis techniques. Many differences were found between the space samples and the ground samples. It could be concluded that gravity condition had a strong influence on the solidification behavior of materials. The temperature gradient driven convection, i.e. Marangoni Convection, played an apparent role on the formation of solidification microstructure under microgravity.

  16. Formation of Ta-Al intermetallics by combustion synthesis involving Al-based thermite reactions

    Energy Technology Data Exchange (ETDEWEB)

    Yeh, C.L., E-mail: clyeh@fcu.edu.t [Department of Aerospace and Systems Engineering, Feng Chia University, 100 Wenhwa Road, Seatwen, Taichung 40724, Taiwan (China); Wang, H.J. [Department of Aerospace and Systems Engineering, Feng Chia University, 100 Wenhwa Road, Seatwen, Taichung 40724, Taiwan (China)

    2010-02-18

    Thermite-based combustion synthesis was conducted to investigate in situ formation of tantalum aluminides (Ta{sub 2}Al, TaAl, TaAl{sub 2}, and TaAl{sub 3}) and Al{sub 2}O{sub 3} from the powder compacts of Al and Ta{sub 2}O{sub 5} under a molar ratio ranging from Al/Ta{sub 2}O{sub 5} = 13/3 to 28/3. Effects of the sample stoichiometry on the combustion behavior and degree of phase conversion were studied. Experimental evidence showed that upon ignition, the synthesis reaction proceeded in a self-sustaining manner featuring a planar combustion front or two localized reaction zones traveling spirally. The combustion front temperature varies between 1135 and 1460 {sup o}C. In agreement with composition dependence of the reaction exothermicity, the reaction front velocity in the axial direction increased from 5.8 to 7.2 mm/s with molar ratio of Al/Ta{sub 2}O{sub 5} from 13/3 to 16/3, beyond which the flame velocity decreased substantially. The slowest reaction front with an axial velocity of 1.15 mm/s was observed in the sample of Al/Ta{sub 2}O{sub 5} = 28/3. Based upon the XRD analysis, in situ formation of the composites composed of Al{sub 2}O{sub 3} and tantalum aluminides was confirmed. For the samples with Al contents of Al/Ta{sub 2}O{sub 5} = 13/3-18/3, an increase in the Al/Ta{sub 2}O{sub 5} ratio improved the production of tantalum aluminides and caused the change in the dominant aluminide phase from Ta{sub 2}Al, TaAl, to TaAl{sub 2}. Due to lack of adequate reaction time, the phase conversion was not stoichiometrically achieved in the samples of Al/Ta{sub 2}O{sub 5} = 13/3-18/3. However, it was found that the slower reaction front provided longer reaction time to complete the phase conversion almost stoichiometrically in the samples of Al/Ta{sub 2}O{sub 5} = 22/3-28/3, which yielded the Al-rich phases TaAl{sub 2} and/or TaAl{sub 3} in the final products.

  17. Formation of Ta-Al intermetallics by combustion synthesis involving Al-based thermite reactions

    International Nuclear Information System (INIS)

    Thermite-based combustion synthesis was conducted to investigate in situ formation of tantalum aluminides (Ta2Al, TaAl, TaAl2, and TaAl3) and Al2O3 from the powder compacts of Al and Ta2O5 under a molar ratio ranging from Al/Ta2O5 = 13/3 to 28/3. Effects of the sample stoichiometry on the combustion behavior and degree of phase conversion were studied. Experimental evidence showed that upon ignition, the synthesis reaction proceeded in a self-sustaining manner featuring a planar combustion front or two localized reaction zones traveling spirally. The combustion front temperature varies between 1135 and 1460 oC. In agreement with composition dependence of the reaction exothermicity, the reaction front velocity in the axial direction increased from 5.8 to 7.2 mm/s with molar ratio of Al/Ta2O5 from 13/3 to 16/3, beyond which the flame velocity decreased substantially. The slowest reaction front with an axial velocity of 1.15 mm/s was observed in the sample of Al/Ta2O5 = 28/3. Based upon the XRD analysis, in situ formation of the composites composed of Al2O3 and tantalum aluminides was confirmed. For the samples with Al contents of Al/Ta2O5 = 13/3-18/3, an increase in the Al/Ta2O5 ratio improved the production of tantalum aluminides and caused the change iantalum aluminides and caused the change in the dominant aluminide phase from Ta2Al, TaAl, to TaAl2. Due to lack of adequate reaction time, the phase conversion was not stoichiometrically achieved in the samples of Al/Ta2O5 = 13/3-18/3. However, it was found that the slower reaction front provided longer reaction time to complete the phase conversion almost stoichiometrically in the samples of Al/Ta2O5 = 22/3-28/3, which yielded the Al-rich phases TaAl2 and/or TaAl3 in the final products.

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

    Science.gov (United States)

    Perez, E.; Ewh, A.; Liu, J.; Yuan, B.; Keiser, D. D., Jr.; Sohn, Y. H.

    2009-11-01

    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 °C. These alloys were triple arc-melted, homogenized at 500 °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-UAl 3, orthorhombic-UAl 4, hexagonal-U 6Mo 4Al 43 and diamond cubic-UMo 2Al 20, 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 °C was constructed. The fcc-Al solid solution, orthorhombic-UAl 4, and diamond cubic-UMo 2Al 20 which were determined to be the equilibrium phases in 85.7Al-11.44U-2.86Mo and 87.5Al-10U-2.5Mo alloys.

  19. Fabrication of Nb and Ta/Al/AlOx/Al/Nb tunneling junction X-ray detectors: a list of problems

    International Nuclear Information System (INIS)

    A whole wafer fabrication procedure using selective etching of refractory materials to produce Nb- or Ta/Al/AlOxAl/Nb tunneling X-ray detectors is discussed. Fabrication aspects and preliminary results are presented. (orig.)

  20. 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

  1. 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.

  2. Atomistic Modeling of RuAl and (RuNi) Al Alloys

    Science.gov (United States)

    Gargano, Pablo; Mosca, Hugo; Bozzolo, Guillermo; Noebe, Ronald D.; Gray, Hugh R. (Technical Monitor)

    2002-01-01

    Atomistic modeling of RuAl and RuAlNi alloys, using the BFS (Bozzolo-Ferrante-Smith) method for alloys is performed. The lattice parameter and energy of formation of B2 RuAl as a function of stoichiometry and the lattice parameter of (Ru(sub 50-x)Ni(sub x)Al(sub 50)) alloys as a function of Ni concentration are computed. BFS based Monte Carlo simulations indicate that compositions close to Ru25Ni25Al50 are single phase with no obvious evidence of a miscibility gap and separation of the individual B2 phases.

  3. Formation of AlFeSi phase in AlSi12 alloy with Ce addition

    OpenAIRE

    Kores, S.; Vonc?ina, M.; Kosec, B.; Medved, J.

    2012-01-01

    The influence of cerium addition on the solidification sequence and microstructure constituents of the Al-Si alloys with 12,6 mass % Si was examined. The solidification was analyzed by a simple thermal analysis. The microstructures were examined with conventional light and scanning electron microscopy. Ternary AlSiCe phase was formed in the Al-Si alloys with added cerium during the solidification process. AlSiCe and ?-AlFeSi phases solidified together in the region that solidified the last. ...

  4. The magnetostriction of PrAl2 and TbAl2

    International Nuclear Information System (INIS)

    The magnetostriction of single crystals of PrAl2 and TbAl2 has been measured throughout the ordered state. The magnetoelastic constants M2sup(#betta#) and M2sup(epsilon) have been determined. Previous work has already established that the point-charge model accounts satisfactorily for the magnetoelastic constants of NdAl2. The present results show that this model applies equally well to TbAl2 and would probably do so for PrAl2 if better values for the cubic crystal field parameters could be obtained. (author)

  5. 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)

  6. [A strategy to develop effective ALS therapy].

    Science.gov (United States)

    Mitsumoto, Hiroshi

    2007-04-01

    In the early 1990s, a number of major events took place in the history of the treatment and science of ALS. A cause of familial ALS, the mutation of superoxide dismutase 1, was discovered and very shortly after, an animal model expressing the human SOD1 mutation for familial ALS was generated. Around the same time, the first medication for the treatment of ALS, riluzole, was approved. Clinical neurologists started to focus more attention on quality of life and standardizing care for patients with ALS, including devising approaches for presenting and discussing the diagnosis, using aggressive symptomatic treatments, and developing a multidisciplinary care system. Since then, nutritional and respiratory care has markedly improved. Respiratory care for those with terminal ALS in Japan has been distinct and perhaps more effective compared to the rest of the world, and this unique experience must be broadly published and shared with others. In 1999, the ALS Treatment Guidelines were published by the American Academy of Neurology and are now under revision. A monitoring system to determine the impact the Guidelines had on actual patient care has taught us that caregivers have only slowly accepted the recommendation to improve quality of care. The team approach, using a multidisciplinary care system from diagnosis to the end of life, is essential to improve care for both the patient and family. Coinciding with the progress in ALS treatment, basic science and translational research also produced dramatic progress in ALS drug discovery. Over the past 15 years, more than 25 potential drugs have been tested in randomized controlled trials. Despite this progress, we have no medications other than riluzole. Although it may be true that ALS research is in its early stages compared to research in other diseases with no cure--it is probably behind cancer research by at least 20 or 30 years--we need to drastically change our approach to drug development. At a national level, we need to create a strong, cohesive team with support from a number of funding agencies, oversight from a regulatory agency, and investigators who all think "outside the box." In addition, we should obtain ideas and suggestions from accomplished experts outside of the field of ALS and put competition aside as we work together to develop strategic plans for the ALS drug development that is essential to beat this devastating disease. PMID:17447525

  7. Lattice misfit variation of Al3(Ti, V, Zr) in Al-Ti-V-Zr alloys

    International Nuclear Information System (INIS)

    It seems likely that high-strength Al-base alloys useful up to 698K can be developed in view of the behavior of nickel base superalloys which resist degradation of mechanical properties to 75 pct of their absolute melting temperature. For high temperature Al alloys, the dispersed hardening phase must not undergo phase transformation to an undesirable phase during long time exposure at the temperature of interest. An additional factor to be considered is the stability of the hardening phase with respect to Ostwald ripening. This coarsening resistance is necessary so that the required strength level can be maintained after the long-time service at high temperatures. A good lattice matching between the intermetallic compound and the aluminum matrix is necessary to promote a low interfacial energy and thus, a low driving force for particle coarsening. In this paper, several Al-base systems containing transition metal elements for potential elevated temperature use were suggested based on low values of diffusivities and solubilities. The equilibrium crystal structures of Al3Ti, Al3V and Al3Zr are tetragonal DO22, DO22 and DO23, respectively. At the temperatures of interest, around 698K, vanadium and titanium are mutually substitutable in the form of Al3(Ti, V). Much of titanium and vanadium can be substituted for zirconium in the DO23-type Al3Zr compound, creating Al33Zr compound, creating Al3(Ti, Zr) and Al3(V, Zr), respectively

  8. Substrate bias effect on Al-Si and Al-Ge thin film structure

    International Nuclear Information System (INIS)

    Phase-separated Al-Si and Al-Ge films, composed of Al cylinders embedded in an amorphous Si and Ge matrix, respectively, were investigated by sputtering method with substrate bias voltage. In the Al-Si system, the period of Al cylinders was increased by applying a negative bias voltage to the substrate, which is consistent with the simulation results. On the other hand, the diameter of Al cylinders increased up to a bias voltage of - 80 V, and then it began decreasing beyond - 100 V accompanied by the appearance of a chain-like arrangement of Al cylinders. In the Al-Ge system, the period and diameter of Al cylinders increased by applying a negative bias voltage. However, in the Ge-rich film prepared at a high bias voltage, relatively large dots with low area density were observed. Transmission electron microscope observation revealed that the film was composed of AlGe ?2 phase as a matrix and Al-rich amorphous dots

  9. Nanoindentation Study of Al356-Al2O3 Nanocomposite Prepared by Ball Milling

    Directory of Open Access Journals (Sweden)

    Y. Mazaheri

    2010-10-01

    Full Text Available In this study ball milling of Al356 and Al2O3 powder mixture was carried out in order to produce Al356-Al2O3 nano-composite containing 20 vol.% Al2O3. The structural evolution and morphological changes of powder particles during ball milling were studied by X-ray diffractometery and scanning electron microscopy analysis. As a result of ball milling Al2O3 particles were uniformly dispersed in Al356 matrix. Furthermore the crystallite size of the Al356 decreased to 25 nm after ball milling for 10 h. Morphological studies of powder particles indicated that the powder particle size continuously decreases with increasing milling time. Hardness and elastic modulus values of powder particles were measured by nanoindentation method. It was found that the hardness and elastic modulus of Al356-20 vol.% Al2O3 nanocomposite were about 216 Hv and 86 GPa, respectively which is higher than 75 Hv and 74 GPa for as-received Al356.

  10. Microstructure and mechanical properties of Al2O3-Al composite coatings deposited by plasma spraying

    International Nuclear Information System (INIS)

    Al2O3 and Al2O3-Al composite coatings were prepared by plasma spraying. Phase composition of powders and as-sprayed coatings was determined by X-ray diffraction (XRD), while optical microscopy (OM) and scanning electron microscopy (SEM) were employed to investigate the morphology of impacted droplets, polished and fractured surface, and the element distribution in terms of wavelength-dispersive spectrometer (WDS). Mechanical properties including microhardness, adhesion and bending strength, fracture toughness and sliding wear rate were evaluated. The results indicated that the addition of Al into Al2O3 was beneficial to decrease the splashing of impinging droplets and to increase the deposition efficiency. The Al2O3-Al composite coating exhibited homogeneously dispersed pores and the co-sprayed Al particles were considered to be distributed in the splat boundary. Compared with Al2O3 coating, the composite coating showed slightly lower hardness, whereas the coexistence of metal Al phase and Al2O3 ceramic phase effectively improved the toughness, strength and wear resistance of coatings

  11. Microstructure and mechanical properties of Al 2O 3-Al composite coatings deposited by plasma spraying

    Science.gov (United States)

    Yin, Zhijian; Tao, Shunyan; Zhou, Xiaming; Ding, Chuanxian

    2008-01-01

    Al 2O 3 and Al 2O 3-Al composite coatings were prepared by plasma spraying. Phase composition of powders and as-sprayed coatings was determined by X-ray diffraction (XRD), while optical microscopy (OM) and scanning electron microscopy (SEM) were employed to investigate the morphology of impacted droplets, polished and fractured surface, and the element distribution in terms of wavelength-dispersive spectrometer (WDS). Mechanical properties including microhardness, adhesion and bending strength, fracture toughness and sliding wear rate were evaluated. The results indicated that the addition of Al into Al 2O 3 was beneficial to decrease the splashing of impinging droplets and to increase the deposition efficiency. The Al 2O 3-Al composite coating exhibited homogeneously dispersed pores and the co-sprayed Al particles were considered to be distributed in the splat boundary. Compared with Al 2O 3 coating, the composite coating showed slightly lower hardness, whereas the coexistence of metal Al phase and Al 2O 3 ceramic phase effectively improved the toughness, strength and wear resistance of coatings.

  12. Short range order in Al-Fe-Nb, Al-Fe-Ce and Al-Ni-Ce metallic glasses

    International Nuclear Information System (INIS)

    Short range order of amorphous samples with Al90Fe7Nb3, Al90Fe5Ce5 and Al90Ni5Ce5 nominal composition (in at.%) was studied by X-ray diffraction (XRD) at room temperature (RT). The total structure factors STot(Q) and the reduced atomic distribution function G(r) were derived from the diffracted intensity IM(Q). All the STot(Q) factors are composed by an initial prepeak followed by a main peak and a second peak with two components. Though the general aspect of the different samples is similar they present slight differences in details that are discussed as a function of the composition and compared with available data in the literature. While in the Al-(Fe, Ni)-Ce alloys two distinct components were observed for the first peak of the G(r) function, a unique broad peak was observed in the Nb containing alloy. The pair correlation function, g(r), for Al90Fe10 at 200 K have been calculated with molecular dynamics simulation (MDS) and it is in good agreement with the experimental results obtained from Al90Fe7Nb3 showing that size effects can be neglected in this sample.

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

    Directory of Open Access Journals (Sweden)

    K. Tawaraya

    2009-01-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-11-01

    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.

  15. Effect of Al compounds on soil pH and bioavailability of Al in two acid soils

    OpenAIRE

    IQBAL, Md. Toufiq

    2012-01-01

    Two aluminum compounds, AlCl3 and Al(OH)3, were used to determine the effect of Al compounds on pH and bioavailability of Al in 2 acid soils. Both soils were incubated for periods of 3, 10, and 30 days. Al-tolerant (ET8) and Al-sensitive (ES8) wheat seedlings were used as a testing plant to confirm bioavailability of Al3+ in soil solution. Both soils were acidified through the addition of Al compounds to detect the maximum Al3+ toxicity level of these compounds. The results showed that the Al...

  16. CALCULUL CINETOSTATIC AL MECANISMELOR PLANETARE CILINDRICE

    Directory of Open Access Journals (Sweden)

    P?un ANTONESCU

    2012-05-01

    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?.

  17. RESPUESTA HIPERTENSIVA AL ESFUERZO EN PACIENTES PREHIPERTENSOS

    Directory of Open Access Journals (Sweden)

    Tom\\u00E1s Noel Santana T\\u00E9llez

    2007-01-01

    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.

  18. Johann Barvitius als Mäzen im rudolfinischen Prag.

    Czech Academy of Sciences Publication Activity Database

    Šron?k, Michal

    -, ?. 8 (2008), s. 49-57. ISSN 1213-5372 Institutional research plan: CEZ:AV0Z80330511 Keywords : Rudolfine art * Hans von Aachen * Johann Barvitius Subject RIV: AL - Art, Architecture, Cultural Heritage

  19. [Nordosteuropa als Geschichtsregion] / Hans-Jürgen Bömelburg

    Index Scriptorium Estoniae

    Bömelburg, Hans-Jürgen

    2009-01-01

    Nordosteuropa als Geschichtsregion. Beiträge des III. Internationalen Symposiums zur deutschen Kultur und Geschichte im europäischen Nordosten vom 20.-22. September 2001 in Tallinn. Lübeck : Verlag Schmidt-Römhild 2006. (Veröffentlihungen der Aue-Stiftung. 17)

  20. Na?ar?yat al-Fan?’ f? al-Tur?th al-??f? al-Ind?n?s?: Dir?sah Ta?l?l?yah

    Directory of Open Access Journals (Sweden)

    Masri Elmahsyar Bidin

    2009-08-01

    Full Text Available This article attempts to analyze deeply concept of fana' that expanded by Indonesian Sufis such as Hamzah Fansuri and Muhammad Nat'is aI' Banjari, in relation with other Sufis in the Muslim zeroed such as lbnu 'Arabi, Abi Yazid al-Bustami, and al-Ghazali. Connection with Indian philosophy like Nirvana and Yoga will also be explored. In the courses of its development, the concept of fana' has triggered controversies in intellectual community, and even there it yielded some prejudices among them that this concept was religious deviation in the Muslim world. This can be seen for example in the cases of al-Hallaj as he said "And al-Haq (I am the God, and Siti Jenar as he said "there is no Siti Jenar, there is God".Copyright (c 2014 by SDI. All right reserved.DOI: 10.15408/sdi.v16i2.484

  1. In Situ Fabrication of AlN Coating by Reactive Plasma Spraying of Al/AlN Powder

    Directory of Open Access Journals (Sweden)

    Mohammed Shahien

    2011-10-01

    Full Text Available Reactive plasma spraying is a promising technology for the in situ formation of aluminum nitride (AlN coatings. Recently, it became possible to fabricate cubic-AlN-(c-AlN based coatings through reactive plasma spraying of Al powder in an ambient atmosphere. However, it was difficult to fabricate a coating with high AlN content and suitable thickness due to the coalescence of the Al particles. In this study, the influence of using AlN additive (h-AlN to increase the AlN content of the coating and improve the reaction process was investigated. The simple mixing of Al and AlN powders was not suitable for fabricating AlN coatings through reactive plasma spraying. However, it was possible to prepare a homogenously mixed, agglomerated and dispersed Al/AlN mixture (which enabled in-flight interaction between the powder and the surrounding plasma by wet-mixing in a planetary mill. Increasing the AlN content in the mixture prevented coalescence and increased the nitride content gradually. Using 30 to 40 wt% AlN was sufficient to fabricate a thick (more than 200 µm AlN coating with high hardness (approximately 1000 Hv. The AlN additive prevented the coalescence of Al metal and enhanced post-deposition nitriding through N2 plasma irradiation by allowing the nitriding species in the plasma to impinge on a larger Al surface area. Using AlN as a feedstock additive was found to be a suitable method for fabricating AlN coatings by reactive plasma spraying. Moreover, the fabricated coatings consist of hexagonal (h-AlN, c-AlN (rock-salt and zinc-blend phases and certain oxides: aluminum oxynitride (Al5O6N, cubic sphalerite Al23O27N5 (ALON and Al2O3. The zinc-blend c-AlN and ALON phases were attributed to the transformation of the h-AlN feedstock during the reactive plasma spraying. Thus, the zinc-blend c-AlN and ALON phases were not included in the feedstock and were not formed through nitriding of the Al.

  2. La crítica wittgensteiniana al lenguaje privado

    Scientific Electronic Library Online (English)

    María Teresa, Muñoz Sánchez.

    2009-06-01

    Full Text Available Este artículo hace una exposición del argumento wittgensteiniano contra el lenguaje privado como un ataque al tradicional mentalismo egocéntrico moderno. Al mismo tiempo, defiende una concepción alternativa de la normatividad epistémica y la justificación lingüística de raigambre wittgensteiniana. [...] Abstract in english This article underscores Wittgenstein's argument against private language as an attack on the traditional self-centered modern mentalism. At the same time, it defends a conception of epistemic normativity and linguistic justification from a wittgensteinian point of view. [...

  3. Structure and stability of Al$_2$Fe

    OpenAIRE

    Mihalkovic?, M.; Widom, M.

    2011-01-01

    We employ first principles total energy and phonon calculations to address the structure and stability of Al$_2$Fe. This structure, which is reported as stable in the assessed Al-Fe phase diagram, is distinguished by an unusually low triclinic symmetry. The initial crystallographic structure determination additionally featured an unusual hole large enough to accommodate an additional atom. Our calculations indicate the hole must be filled, but predict the triclinic structure...

  4. Countering Al-Qaeda’s Single Narrative

    OpenAIRE

    Philipp Holtmann

    2013-01-01

    What form should a counter-narrative to al-Qaeda’s single narrative take? Its claim “Islam is under attack” successfully integrates multiple Muslim grievances into one meta-narrative. It has found credibility beyond an extremist fringe of Muslim societies and has been far more successful and attractive than any counter narrative that has been devised so far by Western counter-terrorist strategists. The question if al-Qaeda’s meta-narrative merely creates an external sc...

  5. vibraciones al paso de un tren

    Directory of Open Access Journals (Sweden)

    Jes\\u00FAs Otero Yugat

    2007-01-01

    Full Text Available El presente artículo resume los modelos empleados para representar las vibraciones generadas al paso de un tren, así como también su transmisión al entorno. Estos métodos permiten determinar la respuesta dinámica de la vía ferroviaria, considerando las fuerzas desarrolladas en el área de contacto ruedacarril, el perfil de irregularidades de la rueda, la impedancia del terreno y los mecanismos de transmisión hacia el hastial del túnel. Adicionalmente, se presenta una revisión de las técnicas de detección de vibraciones más usuales.

  6. Effects of Al substitution on goethite formation

    OpenAIRE

    Premoli, Alessandra Maria; Melis, Pietro; Gessa, Carlo Emanuele; Deiana, Salvatore Andrea

    1984-01-01

    Goethites containing up to 32.7 mole % Al were synthesized and characterized through diffractometry, spectrometry, DSC and chemical techniques. Results indicate that crystal growth was favoured or hindered depending on the percentage of aluminum incorporated into the structure. Goethites to which 5-10 mole % Al were initially added crystallized best, as shown by the highest crystallite dimensions calculated from X-ray and Mössbauer analyses, and by the lowest surface areas values. Over su...

  7. Veränderte Genexpression als Grundlage für vaskuläres Remodeling

    Directory of Open Access Journals (Sweden)

    Lang I

    2000-01-01

    Full Text Available Gefäßwandumbau oder "vascular remodeling" ist definiert als Änderung im Gefäßkaliber, oft ohne Veränderung der Gesamtgewebsmasse. Die Verfügbarkeit des intravaskulären Ultraschalls hat dazu geführt, Gefäßremodeling als dynamischen Prozeß zu beobachten. Zelltod, Zellwachstum, Zellmigration und Produktion oder Abbau extrazellulärer Matrix sind durch die Expression von Genen in der Gefäßwand gesteuert. Anhand von Analysen solcher Genexpressionsmuster in verschiedenen Gefäßgebieten wird die Signifikanz des Forschungskonzepts "Genexpression in der Gefäßwand" an Beispielen illustriert.

  8. Continuous germanene layer on al(111).

    Science.gov (United States)

    Derivaz, Mickael; Dentel, Didier; Stephan, Régis; Hanf, Marie-Christine; Mehdaoui, Ahmed; Sonnet, Philippe; Pirri, Carmelo

    2015-04-01

    Germanene, a 2D honeycomb structure similar to silicene, has been fabricated on Al(111). The 2D germanene layer covers uniformly the substrate with a large coherence over the Al(111) surface atomic plane. It is characterized by a (3 × 3) superstructure with respect to the substrate lattice, shown by low energy electron diffraction and scanning tunnelling microscopy. First-principles calculations indicate that the Ge atoms accommodate in a very regular atomic configuration with a buckled conformation. PMID:25802988

  9. Periodistas: el acceso al mercado laboral

    OpenAIRE

    Lez, Francisco Javier Caro Gonz U. E.; Nez Marin, Gloria Jim U. E.

    2006-01-01

    El presente estudio analiza la situación profesional de los Licenciados en Periodismo en España. Para ello esta investigación sigue la lógica del proceso de acceso al mercado laboral, es decir, se estudia, en primer lugar, la oferta de egresados y las demandas del sector; a continuación, se analiza la forma en la que un titulado en la Licenciatura de Periodismo accede al mercado laboral y el tiempo que tarda en hacerlo; y por último, se examinan los medios de comunicació...

  10. 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.

  11. Mechanical alloying of Al and Zn

    International Nuclear Information System (INIS)

    Mechanical alloying by ball milling is a useful tool for producing materials far from thermodynamic equilibrium. This technique enhances the solubility of solute which is due to a large fraction of grain boundaries and generation of very high density of dislocations. A project has been initiated for alloying Zn with Al. As received powders of Al and Zn were examined in scanning electron microscope (SEM) and the Size range of Al and Zn were found to be 1-125 micro meter and 50-850 micro meter respectively. In order to reduce the particle size, Zn powder was milled using different ball to powder weight ratio in a planetary ball mill. A ratio of 20:1 was then selected and used to produce an alloy of Al with 10 wt % Zn. Pellets of the alloy powders were prepared using a load of 5 tons for 3 minutes. The alloy powders and pellets were examined in SEM and analyzed by electron probe micro analyzer (EPMA). X-ray diffraction (XRD) patterns of the pellets were taken. SEM, EPMA and XRD examinations confirm that alloying has taken place with enhancement in solubility of Zn in Al. Increase in Vickers's micro hardness of the alloy as compared to that of Al has been observed. In this paper, these results would be presented and discussed. (author)

  12. 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

  13. Spectroscopic analysis of the open 3d subshell transition metal aluminides: AlV, AlCr, and AlCo

    Science.gov (United States)

    Behm, Jane M.; Brugh, Dale J.; Morse, Michael D.

    1994-10-01

    Three open 3d subshell transition metal aluminides, AlV, AlCr, and AlCo, have been investigated by resonant two-photon ionization spectroscopy to elucidate the chemical bonding in these diatomic molecules. The open nature of the 3d subshell results in a vast number of excited electronic states in these species, allowing bond strengths to be measured by the observation of abrupt predissociation thresholds in a congested optical spectrum, giving D00(AlV)=1.489±0.010 eV, D00(AlCr)=2.272±0.009 eV, and D00(AlCo)=1.844±0.002 eV. At lower excitation energies the presence of discrete transitions has permitted determinations of the ground state symmetries and bond lengths of AlV and AlCo through rotationally resolved studies, giving r0` (AlV, ?`=0)=2.620±0.004 Å and r0` (AlCo, ?`=3)=2.3833±0.0005 Å. Ionization energies were also measured for all three species, yielding IE(AlV)=6.01±0.10 eV, IE(AlCr)=5.96±0.04 eV, and IE(AlCo)=6.99±0.17 eV. A discussion of these results is presented in the context of previous work on AlCu, AlNi, AlCa, and AlZn.

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

    Directory of Open Access Journals (Sweden)

    Toto Saputra

    2008-01-01

    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.

  15. Predicting glass-forming compositions in the Al-La and Al-La-Ni systems

    Energy Technology Data Exchange (ETDEWEB)

    Gargarella, P., E-mail: p.gargarella@ifw-dresden.de [IFW Dresden, Institut fuer Komplexe Materialien, Helmholtzstrasse 20, D-01069, Dresden (Germany); de Oliveira, M.F. [Departamento de Engenharia de Materiais, Aeronautica e Automobilistica, Universidade de Sao Paulo, Av. Trabalhador Sancarlense, 400, 12560-970, Sao Carlos, Sao Paulo (Brazil); Kiminami, C.S. [Departamento de Engenharia de Materiais, Universidade Federal de Sao Carlos, Rod. Washington Luis Km 235, 13565-905, Sao Carlos (Brazil); Pauly, S.; Kuehn, U. [IFW Dresden, Institut fuer Komplexe Materialien, Helmholtzstrasse 20, D-01069, Dresden (Germany); Bolfarini, C.; Botta, W.J. [Departamento de Engenharia de Materiais, Universidade Federal de Sao Carlos, Rod. Washington Luis Km 235, 13565-905, Sao Carlos (Brazil); Eckert, J. [IFW Dresden, Institut fuer Komplexe Materialien, Helmholtzstrasse 20, D-01069, Dresden (Germany); Institut fuer Werkstoffwissenschaft, Technische Universitaet Dresden, D-01062, Dresden (Germany)

    2011-06-15

    Research highlights: > The glass-forming ability of the Al-La and Al-La-Ni systems was studied using the {lambda}* and the {lambda}.{Delta}e criteria. > Both criteria predicted with just 1% at. of error the best glass-former verified so far in the Al-La system. > Four new glass-former compositions could be predicted in the Al-La-Ni system using the {lambda}.{Delta}e criterion. > The best glass-former reported so far in the Al-La-Ni system was found. - Abstract: In this work, a criterion considering the topological instability ({lambda}) and the differences in the electronegativity of the constituent elements ({Delta}e) was applied to the Al-La and Al-Ni-La systems in order to predict the best glass-forming compositions. The results were compared with literature data and with our own experimental data for the Al-La-Ni system. The alloy described in the literature as the best glass former in the Al-La system is located near the point with local maximum for the {lambda}.{Delta}e criterion. A good agreement was found between the predictions of the {lambda}.{Delta}e criterion and literature data in the Al-La-Ni system, with the region of the best glass-forming ability (GFA) and largest supercooled liquid region ({Delta}T{sub x}) coinciding with the best compositional region for amorphization indicated by the {lambda}.{Delta}e criterion. Four new glassy compositions were found in the Al-La-Ni system, with the best predicted composition presenting the best glass-forming ability observed so far for this system. Although the {lambda}.{Delta}e criterion needs further refinements for completely describe the glass-forming ability in the Al-La and Al-La-Ni systems, the results demonstrated that this criterion is a good tool to predict new glass-forming compositions.

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

    Science.gov (United States)

    Hickmott, T. W.

    2013-12-01

    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.

  17. 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

  18. More momentum instead of mass. Network control by municipal public utilities; Mehr Schwung statt Masse. Netzsteuerung durch Stadtwerke

    Energy Technology Data Exchange (ETDEWEB)

    Schwarzburger, Heiko

    2013-10-01

    Inverters can simulate the inertia of the turbine and generator from conventional power plants. Therefore the fossil power power plants blocks are unnecessary. From 2017 solar farms have to enable this function. [German] Wechselrichter koennen die Traegheit der Turbinen und Generatoren aus herkoemmlichen Kraftwerken nachbilden. Damit werden die fossilen Bloecke ueberfluessig. Ab 2017 muessen Solarparks diese Funktion ermoeglichen.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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)

  20. 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.

  1. 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)

  2. Ultraviolet photoluminescence excitation spectroscopy of AlGaN and AlN

    Energy Technology Data Exchange (ETDEWEB)

    Feneberg, Martin [Abteilung Materialphysik, Otto-von-Guericke-Universitaet, Magdeburg (Germany); Institut fuer Quantenmaterie, Gruppe Halbleiterphysik, Universitaet Ulm (Germany); Neuschl, Benjamin; Meisch, Tobias; Thonke, Klaus [Institut fuer Quantenmaterie, Gruppe Halbleiterphysik, Universitaet Ulm (Germany); Metzner, Robert; Garke, Bernd; Goldhahn, Ruediger [Abteilung Materialphysik, Otto-von-Guericke-Universitaet, Magdeburg (Germany)

    2011-07-01

    We present first results of photoluminescence excitation spectroscopy on AlN thin films and high aluminum content AlGaN layers. These studies were performed at the DORIS III synchrotron, DESY, Hamburg. The origin of observed deep emission bands in AlN can be distinguished between substrate and epilayer. In high aluminum content AlGaN, position and shape of the ordinary absorption edge can be observed. These data are compared to the ordinary dielectric function obtained by spectroscopic ellipsometry and to low temperature photoluminescence spectra obtained by ArF excimer laser excitation ({lambda}= 193 nm). We discuss possible origins of so-called ''near band-gap'' luminescence in AlGaN. Furthermore, the experimental data allows insight into energy positions of semi-core level states in AlGaN, which opens a way to determine the Fermi level energy in these materials.

  3. Microscopic Properties of Long-Period Ordering in Al-Rich TiAl Alloys

    Science.gov (United States)

    Hata, S.; Nakano, T.; Kuwano, N.; Itakura, M.; Matsumura, S.; Umakoshi, Y.

    2008-07-01

    The ordering mechanism of long-period superstructures (LPSs) in Al-rich TiAl alloys has been investigated by high-resolution transmission electron microscopy (HRTEM). The LPSs are classified in terms of arrangements of base clusters with different shapes and compositions formed in Ti-rich (002) layers of L10-TiAl matrix: square Ti4Al, fat rhombus Ti3Al, and lean rhombus Ti2Al type clusters. The HRTEM observations revealed that antiphase boundaries of long-range-ordered LPS domains and short-range-ordered microdomains are constructed by various space-filling arrangements of the base clusters. Such a microscopic property characterized by the base clusters and their arrangements is markedly analogous to that of the {left< {{text{1,1/2,0}}} rightrangle } * special-point ordering alloys such as Ni-Mo.

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

    Science.gov (United States)

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

    1998-01-01

    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)

  5. 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.)

  6. Revisiting the Al/Al2O3 Interface: Coherent Interfaces and Misfit Accommodation

    OpenAIRE

    Ghanshyam Pilania; Thijsse, Barend J.; Hoagland, Richard G.; Ivan Lazi?; Valone, Steven M.; Xiang-Yang Liu

    2014-01-01

    We study the coherent and semi-coherent Al/?-Al2O3 interfaces using molecular dynamics simulations with a mixed, metallic-ionic atomistic model. For the coherent interfaces, both Al-terminated and O-terminated nonstoichiometric interfaces have been studied and their relative stability has been established. To understand the misfit accommodation at the semi-coherent interface, a 1-dimensional (1D) misfit dislocation model and a 2-dimensional (2D) dislocation network model have been studied. F...

  7. Revisiting the Al/Al?O? interface: coherent interfaces and misfit accommodation:

    OpenAIRE

    Pilania, G.; Thijsse, B. J.; Hoagland, R. G.; Lazic, I.; Valone, S. M.; Liu, X. Y.

    2014-01-01

    We study the coherent and semi-coherent Al/?-Al2O3 interfaces using molecular dynamics simulations with a mixed, metallic-ionic atomistic model. For the coherent interfaces, both Al-terminated and O-terminated nonstoichiometric interfaces have been studied and their relative stability has been established. To understand the misfit accommodation at the semi-coherent interface, a 1-dimensional (1D) misfit dislocation model and a 2-dimensional (2D) dislocation network model have been studied. F...

  8. The effect of thermal annealing on the properties of Al-AlOx-Al single electron tunneling transistors

    CERN Document Server

    Scherer, H; Zorin, A B; Niemeyer, J C; Weimann, Th.

    2001-01-01

    The effect of thermal annealing on the properties of Al-AlOx-Al single electron tunneling transistors is reported. After treatment of the devices by annealing processes in forming gas atmosphere at different temperatures and for different times, distinct and reproducible changes of their resistance and capacitance values were found. According to the temperature regime, we observed different behaviors as regards the resistance changes, namely the tendency to decrease the resistance by annealing at T = 200 degree C, but to increase the resistance by annealing at T = 400 degree C. We attribute this behavior to changes in the aluminum oxide barriers of the tunnel junctions. The good reproducibility of these effects with respect to the changes observed allows the proper annealing treatment to be used for post-process tuning of tunnel junction parameters. Also, the influence of the annealing treatment on the noise properties of the transistors at low frequency was investigated. In no case did the noise figures in t...

  9. Chemical Trend of Superconducting Transition Temperature in Hole-doped Delafossite of CuAlO_2, AgAlO_2 and AuAlO_2

    OpenAIRE

    Nakanishi, Akitaka; Katayama-yoshida, Hiroshi

    2012-01-01

    We have performed the first-principles calculations about the superconducting transition temperature T_c of hole-doped delafossite CuAlO_2, AgAlO_2 and AuAlO_2. Calculated T_c are about 50 K(CuAlO_2), 40 K(AgAlO_2) and 3 K(AuAlO_2) at maximum in the optimum hole-doping concentration. The low T_c of AuAlO_2 is attributed to the weak electron-phonon interaction caused by the low covalency and heavy atomic mass.

  10. Microstructure and grain boundary relaxation in ultrafine-grained Al/Al oxide composites

    International Nuclear Information System (INIS)

    The microstructure and grain boundary relaxation in ultrafine-grained Al/Al oxide composites were studied by electron microscopy observation and internal friction measurement, respectively. Both the microstructure and the internal friction behavior of the composites were strongly influenced by the thermomechanical treatment parameters. All the Al particles were still covered by the native amorphous oxide shells in those composites sintered at T < 823 K, and no indication of Al grain boundary relaxation was detected. Some Al oxide shells were cracked, resulting in the formation of a few Al-Al grain boundaries between adjacent particles in the sample sintered at 823 K, and one internal friction peak centered at ?440 K was detected. All the oxide shells were broken into small fragments in those samples sintered at T ? 843 K, and two internal friction peaks were detected, one prominent peak at ?440 K and one weak peak at ?540 K. A microstructure with a bimodal grain size distribution of Al was formed via partial recrystallization after thermomechanical treatment of the sample sintered at 893 K, and two internal friction peaks with comparable intensity were detected. The internal friction peaks were associated with the relaxation of Al grain boundary in the composites.

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

    Directory of Open Access Journals (Sweden)

    Liming Liu

    2014-02-01

    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.

  12. Kit?b al-Tu?fah al-R?gib?n wa al-Radd ‘al? ‘Aq?dah al-Wuj?d?yah bi F?limb?nj fi al-Qarn al-Th?min ‘Ashar al-M?l?d?

    Directory of Open Access Journals (Sweden)

    Nyimas Umi Kalsum

    2004-12-01

    Full Text Available This article tries to discuss one of religion waorks written by al-Palimbani, Tuhfah al-Ragibin, presented the discussion of the author's response towards wujudiyyah, a text that widely spread in Palembang at the time. In line with al-Raniri in Aceh, al-Palimbani divided wujudiyyah's doctrine into two categories: wujudiyyah mulhid and wujudiyyah muwahhid.Copyright (c 2014 by SDI. All right reserved.DOI: 10.15408/sdi.v11i3.597

  13. Structure and composition of MCrAlY coatings modified by Al additions

    OpenAIRE

    Brossa, F.; D'Angelo, D; Gandini, E

    1993-01-01

    Plasma spray techniques have been used to increase the Al content on existing NiCoCrAlY films in order to obtain high temperature resistant coatings on Ni-base superalloys for gas turbine applications. Surface alloying has been produced by thermal diffusion under vacuum of the Al and MCrAlY films. This treatment reduces the surface roughness and increases the coating density by sealing its porosity. The aluminides formed have been analyzed in terms of their structural composition and oxidatio...

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

    Directory of Open Access Journals (Sweden)

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

    2012-07-01

    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.

  15. UNDERSTANDING THE MULTIDIMENSIONAL ISLAMIC FAITH THROUGH ‘ABD AL-GHANI AL-NABULUSI’S MYSTICAL PHILOSOPHY

    Directory of Open Access Journals (Sweden)

    Naoki Yamamoto

    2013-12-01

    Full Text Available This paper tries to present a new perspective on Islamic faith and Muslim identity to Muslim minorities who are challenged in practicing or following Islamic law in non-Islamic countries or non-Muslims in the contemporary world. It will uncover the multidimensional perspective of the concept of faith based on sin (dhanb and repentance (tawbah through the mystical philosophy of a Syrian scholar, Abd al-Ghani al-Nabulusi (d. 1143/1741 of the 18th century Ottoman Damascus who contributed to the field of Sufism particularly based on Ibn ‘Arabi’s thought of wahdat al-wujud (oneness of being and insan kamil (the perfect man. Nabulusi believes that anyone who lived during the inexistence of prophet’s revelation, inhabited an isolated place cut off from information about Islam, or lived in dar al-harb and did not make a hijra to dar al-islam could not be regarded as sinful in their deeds. However, faith in Allah is essential and infidelity is not forgiven regardless whether or not they live in dar al-islam or dar al-harb. Further, Nabulusi insists that true faith can be achieved by understanding the sin of existence; the ignorance of the difference of existence between Allah and men.  [Artikel ini menjelaskan identitas keberagamaan umat Islam minoritas yang dituntut untuk menerapkan syariat, namun harus hidup di negara non-muslim, dengan mendiskusikan perspektif multidimensional terhadap konsep dosa dan tobat seperti dikembangkan oleh Abd al-Ghan? al-Nabulus? (1143/1741, seorang sufi pemikir Syria, khususnya  wahdat al-wuj?d dan insan kamil, yang hidup di masa kesultanan Usmani di Damaskus. Nabulus? berkeyakinan bahwa siapa saja yang hidup sebelum turunnya wahyu di masa Nabi, hidup di daerah terpencil yang tidak mengenal Islam, atau hidup di dar al-harb dan tidak hijrah ke dar al-islam, tidaklah dibebani dosa atas perbuatannya. Namun demikian, iman kepada Allah amatlah penting dan kekufuran tidaklah dimaafkan, baik seseorang tersebut hidup di dar al-islam ataupun dar al-harb. Nabulus? beranggapan bahwa iman yang hakiki bisa dicapai dengan memahami dosa eksistensial, yaitu kegagalan dalam memahami perbedaan antara Allah dan manusia.] Keywords: Ibn ‘Arab?, wahdat al-wuj?d, dar al-harb

  16. Stagnation of the exploitation of Al ores and the depression of world prices of Al

    OpenAIRE

    Slavkovský Jozef

    1999-01-01

    In the contribution, data on Al ? a metal of the 20th century are compiled together with the problems of genesis of the Al mineral raw ma-terials as well as types of bauxite and Al-laterite deposits. Furthermore, an overview of the world exploitation of bauxite during 1935-1980 is given along with the prognoses to 2000 and present situation (1992-1996). Overviews of the production of Al follows, providing its rela-tion to the bauxite exploitation. Contrary to the prognoses, a stabilization ...

  17. Glassy ferromagnetism in Al-doped 4H-SiC: AlSi-V complexes

    Science.gov (United States)

    Yang, Mao; Shi, Jun-jie

    2010-07-01

    The recent observed glassy ferromagnetism in Al-doped 4 H-SiC is investigated using first principles calculations. We find that the formation energy of V is significantly reduced by Al atoms doped in SiC. The Al Si- V complex induces a half-filled narrow a level in the band gap and contributes a net local moment of 1 ?. The exchange parameter J can be either positive or negative along different directions. Both the strong anisotropy of J and the correlation effects of the a level can lead to a glassy ferromagnetism in Al-doped 4 H-SiC.

  18. The Dissociation Energies of AlH2 and AlAr

    Science.gov (United States)

    Ricca, Alessandra; Partridge, Harry; Bauschlicher, Charles W., Jr.; Visscher, Luuk; Langhoff, Stephen R. (Technical Monitor)

    1995-01-01

    The D(sub 0) values for AlH2 and AlAr are computed using the coupled cluster approach in conjunction with large basis sets. Basis set superposition and spin-orbit effects are accounted for as they are sizeable due to the small binding energy. The computed dissociation energy for AlAr is 101 /cm , which is 83% of the experimental value (122.4/ cm). Our best estimate for the H2 binding energy in AlH2 is 40 +/- 28 /cm.

  19. Guinier-Preston zones in Al-rich Al-Cu and Al-Ag single crystals

    DEFF Research Database (Denmark)

    Schönfeld, B.; Malik, A.

    1997-01-01

    Guinier-Preston zones in -Ag and -Cu were investigated by diffuse X-ray and neutron scattering. In Al-3 at% Ag no differences are found between zones formed above and below 500 K (epsilon- and eta-zones, respectively). Their average Ag concentration is (80 +/- 10) at%, and the Ag concentration decreases by 10-15% from shell to core of the zones. In Al-1.75 at% Cu, Guinier-Preston I zones are dominantly monolayers with a Cu fraction of (84 +/- 2) at%.

  20. Medien als Lernform und die Trimediale Redaktion

    Directory of Open Access Journals (Sweden)

    Wolf Hilzensauer

    2015-01-01

    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.

  1. 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

  2. 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

  3. Bush lubas al-Zarqawi järglase kinni püüda / Aadu Hiietamm

    Index Scriptorium Estoniae

    Hiietamm, Aadu, 1954-

    2006-01-01

    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

  4. Deletion of ALS5, ALS6 or ALS7 increases adhesion of Candida albicans to human vascular endothelial and buccal epithelial cells

    OpenAIRE

    Zhao, Xiaomin; Oh, Soon-hwan; Hoyer, Lois L.

    2007-01-01

    C. albicans yeast forms deleted for ALS5, ALS6 or ALS7 are more adherent than a relevant control strain to human vascular endothelial cell monolayers and buccal epithelial cells. In the buccal and vaginal reconstituted human epithelium (RHE) disease models, however, mutant and control strains caused a similar degree of tissue destruction. Deletion of ALS5 or ALS6 significantly slowed growth of the mutant strain; this phenotype was not affected by addition of excess uridine to the culture medi...

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

    Directory of Open Access Journals (Sweden)

    Imriyanti Imriyanti

    2013-12-01

    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

  6. Preliminary Data for the 27Al(p,p'?1)27Al, 27Al(p,p'?2)27Al and 27Al(p,p' ?2-1)27Al Reactions at CMAM-UAM

    International Nuclear Information System (INIS)

    For low energies we used a) the two resonances of the nuclear reaction ''2''7Al(p,?)''2''8Si at 991.7 and 1316.8 keV on thick commercial (Goodfellow) target, and for high energies, as recommended during the 1st RCM b) RBS from MnSnO and the reaction ''1''1B(p,?)8Be on thin samples. For case a) the real terminal voltage has been computed from the equation TVreal = 1/2 (Eres - Vext + Elost) while in case b) it has been deduced from a system of 3 kinematical equations that are solved for the beam energy E0 and then provide E0 = Vext + 2TVreal. The combination of the two data sets gives a calibration curve that associates the real to the nominal terminal voltage. The Scattering Chamber: Installed together with the accelerator in 2002 by HVEE, the Standard Beamline at CMAM is a multipurpose line, mainly used for 'classical' IBA techniques as well as Ion-Beam Modification of Materieals (IBMM) over small areas. It has a 420 mm diameter experimental chamber, equipped with a 4 axis goniometer. A Reverse Electrode Coaxial Ge (ReGe) at 135 degrees with respect to the beam direction and a LaBr3 detector at 45 degree are used temporarily for gamma ray spectroscopy. Two implanted silicon detectors (one fixed and one movable) are used for charged particle detection. Only the fixed detector has been used in the PIGE cross-section measurements. Gamma-ray Detectors Efficiency: The absolamma-ray Detectors Efficiency: The absolute efficiency of both the ReGe and Lanthanum Bromide (LaBr3) gamma detectors has been measured using calibrated sources in two different set-ups. In our 'ToF chamber' we used 133Ba and 22Na sources (5%). Then the measured absolute efficiencies Eabs have been fitted with a power function and rescaled (by the squared ratio of target detector distances) to the 'Standard chamber' geometry, where cross sections have been measured. In a second step the ReGe and LaBr3 detector efficiency has been calibrated with 137Cs and 60Co sources (1%). The graph for the ReGe detector takes into account also preliminary Montecarlo calculations, while the LaBr3 graph is limited to the data obtained with sources. Target Preparation: The samples were prepared with the magnetron sputtering technique. A calibration of the sputtering system at CMAM was performed in order to control the thickness of the Al and Ag layers. For the sputtering calibration six different samples were prepared: three samples with Ag and three with Al. Each sample was prepared with a different sputtering time, the thicknesses of the different Ag and Al layers were determined with the RBS technique. The simulations of the layers were performed with the program RBX. With this calibration we calculated the sputtering time necessary for the nominal thicknesses required for this experiment: 15 ?g/cm2 of Al over 45 ?g/cm2 of Ag; the substrate was a carbon foil of 56 ?g/cm2. A double check is ongoing on the Al and Au thickness using alpha particle RBS: therefore our cross-section values are not to be taken as absolute values yet. Cross-Section Measurements on Al: We scanned the energy range from 2500 keV to 3200 keV in 10 keV steps. As part of the IAEA CRP program we have measured the 27Al(p,p'?1 27 Al (E? = 844 keV), the 27Al(p,p'?2)27Al(E? = 1014 keV) and the 27Al(p,p'?2-1)27Al (E? = 171 keV); the 171 keV peak is isolated on a well subtractable background. The need to measure the target thickness precisely and re-check the MC efficiency calculations for the moment prevents the assignment of an absolute cross-section value. The analysis of further peaks like 27Al(p,??)24Mg ( E? = 1369 keV) and 27Al(p,?)28Si (E? = 1779 keV) is difficult because their peak shape is not gaussian and the peak-to-background ratio is high. Higher energy peaks do not produce, at the energies scanned, statistically significant yields. In the first part of the experiment it became evident that the collimation slits just before the STD chamber were producing a variable aluminium gamma background, most probably generated in the aluminium parts that hold the tantalum slits and depending

  7. Sistemas auditivos anclados al hueso: perspectiva actual

    Directory of Open Access Journals (Sweden)

    Karin Mayt\\u00E9 Dur\\u00E1n Morales

    2013-01-01

    Full Text Available La tecnología de los sistemas auditivos anclados al hueso se adoptó a partir de la investigación dental en implantes de titanio y su proceso de osteointegración. Inicialmente, los sistemas auditivos anclados al hueso se introdujeron para reemplazar los dispositivos de vibración ósea, para pacientes incapaces de usar auxiliares auditivos de conducción aérea (pacientes con cavidades de mastoidectomía, otorrea recurrente, atresia aural congénita. La aplicación más reciente es como método de transmisión transcraneal de la señal en casos de hipoacusia sensorineural unilateral, como neurinoma del acústico, hipoacu- sia súbita, enfermedad de Ménière y otros. En este artículo se revisan la historia de los sistemas auditivos anclados al hueso, su tecnología, sus indicaciones, la cirugía para su colocación, las complicaciones y resultados.

  8. Mechanically alloyed Al-Li powders

    International Nuclear Information System (INIS)

    Mechanically alloyed powders with the composition Al0.7Li0.3 are synthesized. Materials milled for different times are studied using electron microscopy, X-ray diffraction, and thermal analysis. A solid solution of Li in Al (?-phase) is formed with as much as 10 at.% of dissolved Li. The LiAl intermetallic ?-phase is readily produced by mechanical alloying but disappears after extended milling times. The final product of milling for 102 h consists of an X-ray amorphous phase. Mechanically alloyed powders heated in inert environment exhibit several weak exothermic reactions between 420 and 700 K, and two endothermic reactions, around 810 and 870 K. All the observed relaxation processes become less pronounced and eventually become undetectable as the milling time increases and an amorphous material is produced

  9. Hydrogenation properties of Mg-Al alloys

    DEFF Research Database (Denmark)

    Andreasen, Anders

    2008-01-01

    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.

  10. Boron strengthening in FeAl

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

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

    OpenAIRE

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

    2011-01-01

    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...

  12. Structure and stability of the Al14 halides Al14In- (n=1-11): Can we regard the Al14 core as an alkaline earthlike superatom?

    Science.gov (United States)

    Han, Young-Kyu; Jung, Jaehoon

    2006-08-01

    We have studied the structures and stabilities of Al14In- (n=1-11) clusters at the density functional level of theory. The experimentally observed Al14In- (n =3, 5, 7, 9, and 11) [Bergeron et al., Science 307, 231 (2005)] are found to be stable both kinetically and thermodynamically. Al14I3-, not Al14I-, is the first member of the Al14In- series in the mass spectrometric experiment, which is ascribable to the low kinetic stability of the Al14I- cluster. The Al14 core in Al14I3- is close to neutral Al14, both electronically and structurally. Population analysis shows that charge transfer occurs from the Al cluster to the I atoms, where the populations for Al14 vary from -0.70(Al14I-) to +0.96(Al14I11-). The Al14I5- and Al14I7- clusters have the structure of Al14I3- as a core framework, but, for n =9 and 11, we found many more stable isomers than the isomers having the Al14I3- core. In particular, the shape of Al14 in the Al14I11- cluster is a hexagonal wheel-shaped form, which was observed in the x-ray experiment for the metalloid complex [Al14{N(SiMe3)2}6I6Li(OEt2)2]-[Li(OEt2)4]+•toluene [Köhnlein et al., Angew. Chem., Int. Ed. 39, 799 (2000)]. We have demonstrated that a simple jellium model cannot describe the structure and stability of the iodine-doped aluminum clusters, although it is successful for describing those of aluminum clusters. The electronic and geometric changes of the Al14- cluster due to the presence of iodines are very similar to the case of a magic cluster Al13-. It can be concluded from our electronic and structural analysis that one cannot regard the Al14 core as an alkaline earthlike superatom in the Al14 iodide clusters.

  13. Isothermal cross-sections of Sr-Al-Ge and Ba-Al-Ge systems at 673 K

    International Nuclear Information System (INIS)

    X-ray and microstructural analyses are used to study phase equilibria in Sr-Al-Ge and Ba-Al-Ge systems. Existence of SrAl2Ge2, Sr(Al, Ge)2 Ba(Al, Ge)2, Sr3Al2Ge2, Ba3Al2Ge2 ternary compounds is confirmed, a new BaGe4 binary compound and also new ternary compounds of approximate composition Sr57Al30Ge13 and Ba20Al40Ge40, which crystal structure is unknown, are detected. Aluminium solubility in SrAl4 and BaAl4 binary compounds (0.05 atomic fraction) is determined. Ba(Al, Ge)2 compound homogeneity region is defined more exactly (aluminium content varies from 0.27 to 0.51 at. fractions)

  14. Magnetic Properties of NdAl2

    DEFF Research Database (Denmark)

    Bak, P.

    1974-01-01

    The magnetic properties of NdAl2 are calculated using a Hamiltonian including crystal-field and isotropic exchange interaction terms. A two-dimensional mean-field theory is evaluated to calculate single-crystal magnetization curves. It is shown that the magnetic properties can be understood using the crystal-field parameters derived from the magnetic exciton spectrum measured by Houmann et al. by means of inelastic neutron scattering. The combined lambda -Schottky anomaly in the heat capacity is explained. No additional parameters are introduced.

  15. Disorder and epitaxy: Cr on Al?001?

    Science.gov (United States)

    Kim, S. K.; Jona, F.; Marcus, P. M.

    1996-04-01

    Deposition of small amounts (about {1}/{2} of a monolayer) of Cr onto a clean Al{001} surface completely destroys the long-range order in the top 4 or 5 layers of the substrate, as shown by the absence of low-energy electron diffraction (LEED) spots. However, prolonged deposition of Cr produces films which are epitaxial and probably also pseudomorphic with the Al substrate as indicated by quantitative LEED analysis. This observation shows that long-range order of the substrate is not necessary for epitaxial growth of ultrathin metal films.

  16. Traduciendo un nobel caribeño al español

    Directory of Open Access Journals (Sweden)

    Edna Tordecilla

    2008-05-01

    Full Text Available Traducir The Prodigal inevitablemente implica embarcarse con Derek Walcott en un viaje en el que se aprehenden, se disfrutan y se sufren las sensaciones vividas por un ser de herencia multicolor y para quien, al expresar la vida con todas sus alegrías y sinsabores, el arco iris es insuficiente, ya sea que tome un pincel o una pluma. Implica también cruzar virtualmente fronteras geográficas, expandir un poco las fronteras del lenguaje y viajar hacia atrás en la línea del tiempo para visitar lugares y personas conocidas y desconocidas. Al final del camino, el alma llega un poco robusta, ha sido muy bien alimentada y ejercitada.

  17. The ALS Storage Ring RF System

    International Nuclear Information System (INIS)

    The ALS Storage Ring RF System is characterized by the use of the following features: (1) High power loading of two single cell cavities. (2) The use of a tubular ceramic input window employing aperture coupling. (3) The use of waveguide filters and matchers designed for HOM absorption. (4) A comprehensive HOM monitoring system. (5) The use of waveguide water-wedge loads for the magic tee and circulator loads. The results of cavity measurements and high power tests are reported together with the performance of the system during the commissioning and operation phases of the ALS project. Plans for future window development are discussed

  18. The beta-decay of 22Al

    CERN Document Server

    Achouri, N L; Lewitowicz, M; Blank, B; Äystö, J; Canchel, G; Czajkowski, S; Dendooven, P; Emsallem, A; Giovinazzo, J; Guillet, N; Jokinen, A; Laird, A M; Longour, C; Peräjärvi, K; Smirnova, N; Stanoiu, M; Thomas, J C

    2006-01-01

    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 beta-decay half-life of 91.1 +- 0.5 ms was measured. The beta-delayed one- and two-proton emission as well as beta-alpha and beta-delayed gamma 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 4+ for the ground state of 22Al.

  19. Status of the AlCap experiment

    OpenAIRE

    Litchfield, R. Phillip

    2015-01-01

    The AlCap experiment is a joint project between the COMET and Mu2e collaborations. Both experiments intend to look for the lepton-flavour violating conversion $\\mu + A \\rightarrow e + A$, using tertiary muons from high-power pulsed proton beams. In these experiments the products of ordinary muon capture in the muon stopping target are an important concern, both in terms of hit rates in tracking detectors and radiation damage to equipment. The goal of the AlCap experiment is ...

  20. Defect structures in ordered intermetallics; grain boundaries and surfaces in FeAl, NiAl, CoAl and TiAl

    Science.gov (United States)

    Mutasa, Batsirai Manyara

    Ordered intermetallics based on transition metal aluminides have been proposed as structural materials for advanced aerospace applications. The development of these materials, which have the advantages of low density and high operating temperatures, have been focused on the aluminides of titanium, nickel and iron. Though these materials exhibit attractive properties at elevated temperatures, their utilization is limited due to their propensity for low temperature fracture and susceptibility to decreased ductility due to environmental effects. A major embrittlement mechanism at ambient temperatures in these aluminides has been by the loss of cohesive strength at the interfaces (intergranular failure). This study focuses on this mechanism of failure, by undertaking a systematic study of the energies and structures of specific grain boundaries in some of these compounds. The relaxed atomistic grain boundary structures in B2 aluminides, FeAl, NiAl and CoAl and L10 gamma-TiAl were investigated using molecular statics and embedded atom potentials in order to explore general trends for a series of B2 compounds as well as TiAl. The potentials used correctly predict the proper mechanism of compositional disorder of these compounds. Using these potentials, point defects, free surface energies and various grain boundary structures of similar energies in three B2 compounds, FeAl, NiAl and CoAl were studied. These B2 alloys exhibited increasing anti-phase boundary energies respectively. The misorientations chosen for detailed study correspond to the Sigma5(310) and Sigma5(210) boundaries. These boundaries were investigated with consideration given to possible variations in the local chemical composition. The effects of both boundary stoichiometry and bulk stoichiometry on grain boundary energetics were also considered. Defect energies were calculated for boundaries contained in both stoichiometric and off-stoichiometric bulk. The surface energies for these aluminides were also calculated so that trends concerning the cohesive energy of the boundaries could be studied. The implications of stoichiometry, the multiplicity of the boundary structures and possible transformations between them for grain boundary brittleness are also discussed.

  1. ANÁLISIS ESTRUCTURAL PROSPECTIVO APLICADO AL SISTEMA LOGÍSTICO

    Directory of Open Access Journals (Sweden)

    DIANA PAOLA BALLESTEROS RIVEROS

    2008-01-01

    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.

  2. High quality Nb/Al-AlOx/Nb Josephson junctions. Technological development and macroscopic quantum experiments

    International Nuclear Information System (INIS)

    This work describes the development of a technology for producing high-quality submicron Nb/Al-AlOx/Nb Josephson junctions. The resulting components in different experiments have not previously observed macroscopic quantum effects have been demonstrated. Furthermore, Nb-based phase qubits have been designed, fabricated and measured, the longer coherence times than the related components from the literature.

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

    Science.gov (United States)

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

    2014-09-01

    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.

  4. Influence of Al contents on alpha-case formation of Ti-xAl alloys

    International Nuclear Information System (INIS)

    Alpha-case (?-case) formations between Al2O3 mold and Ti-xAl alloys were investigated for the economic Ti-xAl alloys net-shape forming. The ?-case formation reaction was examined in a plasma arc melting furnace. The ?-case reactions between mold and Ti-xAl alloys were characterized by optical microscopy and a hardness tester. When the Al concentration of Ti-xAl alloys was more than 30 at.%, there were no ?-case formation reactions. For the clear examination of the phenomenon, its ?-case formation mechanism was elucidated by an electron probe micro-analyzer, transmission electron microscopy, and thermodynamic calculations. The ?-case was formed not only by interstitial oxygen elements but also by substitutional metallic elements dissolved from mold materials. Therefore, in the case of more than 30 at.% Ti-xAl alloys, there were neither interstitial nor substitutional ?-case formations since Ti-xAl alloys have both negligible solubility of oxygen and low activity in molten states

  5. Characterization of nanophase Al-oxide/Al powders by electron energy-loss spectroscopy.

    Science.gov (United States)

    Fernández; Sánchez-López; Caballero; Martin; Vacher; Ponsonnet

    1998-08-01

    Al nanoparticles were prepared by the inert gas condensation method. After passivation with oxygen and air exposure we obtained a powdered sample of an Al-oxide/Al nanocomposite material. In the present paper we describe the use of the electron energy-loss spectroscopy (EELS) technique in a transmission electron microscope to characterize such nanostructured powders compared with a microcrystalline commercial aluminium foil. Energy-filtered images showed the presence of an alumina overlayer of approximately 4 nm covering the aluminium nanoparticles (23 nm in diameter). EELS analysis enabled us to determine the total amount of Al2O3 and metallic Al and the structure of the alumina passivation overlayer in the sample. In particular, the extended energy-loss fine structure analysis of the data showed a major presence of Al tetrahedrally coordinated with oxygen in the alumina passivation layer of Al nanoparticles instead of the octahedral coordination found for a conventional Al foil. This surprising effect has been attributed to the nanoscopic character of the grains. The analysis of the electron-loss near-edge structure also determines the presence of a certain degree of aggregation in this kind of powdered sample as result of the coalescence of the nanocrystalline grains. The procedure presented here may have the potential to solve other problems during characterization of nanostructured materials. PMID:9767485

  6. The semi-experimental equilibrium structures of AlCCH and AlNC

    Science.gov (United States)

    Mück, Leonie Anna; Thorwirth, Sven; Gauss, Jürgen

    2015-05-01

    Based on experimental rotational constants available in the literature (Walker and Gerry, Chem. Phys. Lett. 278, 9 (1997); Walker et al., J. Mol. Spectrosc. 209, 178 (2001); Sun et al., Chem. Phys. Lett. 553, 11 (2012)) [14,17,19] for five isotopologues of AlCCH and three isotopologues of AlNC as well as quantum-chemical computations for the vibrational corrections to rotational constants, the semi-experimental structures of these two aluminum compounds are determined. These empirical equilibrium structures (AlCCH: re (Alsbnd C) = 1.957 Å, re (Csbnd C) = 1.222 Å, re (Csbnd H) = 1.065 Å; AlNC: re (Alsbnd N) = 1.850 Å, re (Nsbnd C) = 1.181 Å) compare favorably with theoretical best-estimate structures obtained using highly accurate coupled-cluster calculations in combination with sophisticated extrapolation and additivity schemes, i.e., the deviations are smaller than 0.002 Å, but significant deviations are noted in comparison with previously determined experimental structures. Good agreement is also reached between calculations and experimental values for the relevant spectroscopic parameters of AlCCH and AlNC, indicating the predictive power of state-of-the-art high-level quantum-chemical calculations.

  7. Infarto agudo al miocardio asociado al uso de cocaína: ¿una entidad diferente?

    Scientific Electronic Library Online (English)

    Alberto, Fuenzaiida; Martín, Valdebenito; Alejandro, Fajuri.

    Full Text Available El interesante trabajo presentado por Veas et al¹ en este número de la revista genera ciertas interrogantes sobre la fisiopatología y manejo de aquellos pacientes que están cursando un infarto agudo al miocardio con supradesnivel del ST y que refieren consumo reciente de cocaína. [...

  8. Electronic states and spin-forbidden cooling transitions of AlH and AlF.

    Science.gov (United States)

    Wells, Nathan; Lane, Ian C

    2011-11-14

    The feasibility of laser cooling AlH and AlF is investigated using ab initio quantum chemistry. All the electronic states corresponding to the ground and lowest two excited states of the Al atom are calculated using multi-reference configuration interaction (MRCI) and the large AV6Z basis set for AlH. The smaller AVQZ basis set is used to calculate the valence electronic states of AlF. Theoretical Franck-Condon factors are determined for the A(1)?? X(1)?(+) transitions in both radicals and found to agree with the highly diagonal factors found experimentally, suggesting computational chemistry is an effective method for screening suitable laser cooling candidates. AlH does not appear to have a transition quite as diagonal as that in SrF (which has been laser cooled) but the A(1)?? X(1)?(+) transition transition of AlF is a strong candidate for cooling with just a single laser, though the cooling frequency is deep in the UV. Furthermore, the a(3)?? X(1)?(+) transitions are also strongly diagonal and in AlF is a practical method for obtaining very low final temperatures around 3 ?K. PMID:21842049

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

    Science.gov (United States)

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

    2014-09-01

    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.

  10. Beta decay of 24Al and 24Al/sup m/

    International Nuclear Information System (INIS)

    The ?+ decays of 24Al and 24Al/sup m/ have been studied with a Ge(Li) detector. Ten ?+ branches including weak transitions to 24Mg levels at 10576, 10824, 11017 and 11318 keV were observed. The super-allowed ?+ decay of 24Al/sup m/ and two additional branches from 24Al/sup m/ were also detected. The resulting log ft values and GT matrix elements are compared to shell model calculations by Brown, Chung and Wildenthal, which are quite successful in accounting for the data. From ? decay and M1 transition strengths it is concluded that the analog of the 24Al/sup m/ ground state is split between two closely spaced 1+ levels in 24Mg. An isospin violating matrix element of a 50 keV is inferred

  11. 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.)

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

    Science.gov (United States)

    Sullivan, Kyle T.; Chiou, Wen-An; Fiore, Richard; Zachariah, Michael R.

    2010-09-01

    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.

  13. Nucleation and growth of the ?'(AlAg2) precipitate in Al-Ag(-Cu) alloys

    International Nuclear Information System (INIS)

    Precipitation of the ?'(AlAg2) phase was investigated in Al-Ag(-Cu) alloys using high-resolution transmission electron microscopy and scanning transmission electron microscopy. Precipitation commenced with segregation of Ag to stacking faults, followed by thickening in steps corresponding to single unit cell height ledges. In conjunction with gradual segregation of Ag and Al into ordered layers, this yielded ?' phase platelets with a thickness of either 2 or 3 x the AlAg2c-lattice parameter. Plates with a thickness of 2c(AlAg2) could not achieve self-accommodation of the shape strain for transformation. Further thickening of the precipitates was slow, despite considerable Ag segregation around the precipitates. Growth by the addition of single unit cell height ledges is expected to lead to an additional shear strain energy barrier to ledge nucleation and this may contribute to a process of nucleation-limited growth.

  14. 26Mg(p,n)26Al and 23Na(?,n)26Al reactions

    International Nuclear Information System (INIS)

    Cross sections for the 26Mg(p,n)26Al reaction were measured from threshold at 4.988 MeV to 5.820 MeV. Cross sections for the 23Na(?,n)26Al reaction were measured from threshold at 3.483 MeV to 4.597 MeV. In each case, separate measurements were to the ground state and to the first and second excited states of 26Al. Cross sections for the inverse reactions were calculated and reaction rate factors relating to the destruction of 26Al in a supernova environment were determined. Astrophysical implications relating to the observation of live and extinct 26Al are discussed. Excitation functions for several additional exit channels for the 26Mg + rho and 23Na + ? reactions are reported

  15. 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

  16. FABRICATION OF Al/Al2O3 FGM ROTATING DISC

    Directory of Open Access Journals (Sweden)

    A. B. Sanuddin

    2012-06-01

    Full Text Available This study presents a method of fabricating a disc made of Al/Al2O3 functionally graded materials (FGM, using a powder metallurgy manufacturing process. The aim is to develop a processing method for a rotating disc made of FGM, by stacking the slurry, layer by layer in a radial direction. A three-layer functionally graded material of Al/Al2O3 is fabricated with compositions of 10, 20, 30 vol.% Al2O3. The ceramic composition increases from the discs inner (centre to the outer. The combination of these materials can offer the ability to withstand high temperature conditions whilst maintaining strength in extreme environments.

  17. Liquidus temperatures of Na3AlF6-AlF3-CaF2-KF-LiF-Al2O3 melts

    Directory of Open Access Journals (Sweden)

    Peng J.P.

    2014-01-01

    Full Text Available Temperatures for the primary crystallization of Na3AlF6-AlF3-CaF2-KF-LiF-Al2O3 system adopted in aluminum electrolysis process were determined by thermal analysis. An empirical equation was derived to describe the liquidus temperatures for the primary crystallization of this multicomponent electrolyte system: t/?=1011 + 0.7w(AlF3 - 0.232w(AlF32 - 7.65w(Al2O3 + 0.523w(Al2O32 - 8.96w(LiF + 0.043w(LiF2 - 3.32w(KF - 0.12w(KF2 - 3.28w(CaF2 +0.037w(CaF22 + 0.091w(AlF3w(LiF + 0.074w(AlF3w(KF + 0.084w(AlF3w(CaF2 - 0.27w(Al2O3w(LiF, where w(AlF3 denotes the mass fraction of excess aluminum fluoride with respect to cryolite. While w(Al2O3 ranges from 2% to 4%, w(LiF, w(KF and w(CaF2 from 0 to 7%, and the molar ratio of NaF/AlF3 from 2.2 to 3.

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

    Directory of Open Access Journals (Sweden)

    C. Volzone

    2002-09-01

    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.

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

    Science.gov (United States)

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

    2015-02-01

    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.

  20. The modulation structure induced changes in mechanical properties of TiAlN/Al2O3 multilayers

    International Nuclear Information System (INIS)

    TiAlN/Al2O3 multilayers which had different separate layer thickness of TiAlN or Al2O3 were synthesized by sputtering Ti3Al and Al2O3 targets with N2 and Ar gases. The influence of modulation periods and modulation ratios on structure and properties of TiAlN/Al2O3 multilayers was investigated using scanning electron microscopy, X-ray diffraction, X-ray Photoelectron Spectroscopy, surface profiler, and nanoindenter. Compared to TiAlN layer with only (2 0 0) preferred orientation, TiAlN/Al2O3 multilayers were crystallized with orientations in the TiAlN (1 1 1), TiAlN (2 2 2) and AlN (1 0 0). Besides, weak Al2O3 (0 2 2) orientation is observed, when modulation period is 8.9 nm. The maximum hardness about 36.6 GPa was obtained at modulation period of 10.4 nm and modulation ratio of 10:1. The hardness and the toughness of TiAlN/Al2O3 multilayers increase as individual TiAlN layer thickness increases

  1. Ternary Dy-Er-Al magnetic refrigerants

    Science.gov (United States)

    Gschneidner, Jr., Karl A. (Ames, IA); Takeya, Hiroyuki (Ibaraki, JP)

    1995-07-25

    A ternary magnetic refrigerant material comprising (Dy.sub.1-x Er.sub.x)Al.sub.2 for a magnetic refrigerator using the Joule-Brayton thermodynamic cycle spanning a temperature range from about 60K to about 10K, which can be adjusted by changing the Dy to Er ratio of the refrigerant.

  2. Management of respiratory symptoms in ALS.

    LENUS (Irish Health Repository)

    Hardiman, Orla

    2011-03-01

    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.

  3. Thermal mixing of Al-Fe multilayers

    International Nuclear Information System (INIS)

    Al-Fe multilayers have been mixed by thermal treatment and their evolution followed by conversion electron Moessbauer spectroscopy. The initial and final states have been characterized by Rutherford backscattering spectrometry. The results are compared with those previously obtained in the ion beam mixing of similar systems. (orig.)

  4. 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

  5. EMBRIOPATÍAS ASOCIADAS AL USO DE MISOPROSTOL

    Scientific Electronic Library Online (English)

    Andrea, Osorío O; Juan Guillermo, Rodríguez A; Osear, Plzarro R; Axel, Paredes V; Susana, Aguilera P.

    Full Text Available Se presenta un caso clínico de síndrome de Moebius y artrogriposis asociado al uso de misoprostol durante el primer trimestre de gestación [...] Abstract in english We present a case of Moebius syndrome and arthrogriposis associated to the use of misoprostol during the first trimester of gestation. [...

  6. Synthesis of Ti-Al porous perform

    Directory of Open Access Journals (Sweden)

    K. Naplocha

    2008-02-01

    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.

  7. The Science of al-Biruni

    CERN Document Server

    Sparavigna, Amelia Carolina

    2013-01-01

    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.

  8. Management of respiratory symptoms in ALS.

    LENUS (Irish Health Repository)

    Hardiman, Orla

    2012-02-01

    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.

  9. Yusuf al-Qaradawi dan Sumbangan Pemikirannya

    OpenAIRE

    Zulkifli Hasan

    2013-01-01

    Yusuf al-Qaradawi merupakan salah seorang sarjana Islam yang amat berpengaruh dan terulung dalam zaman ini. Beliau terkenal dengan pandangan kesederhanaan dari kacamata mereka yang mengikuti sumbanganpemikirannya dan dianggap sebagai sarjana Islam yang kontroversial oleh lawannya. Beliau juga merupakan sarjana yang syumul, pemimpin yang intelektual, aktivis sosial, Muslim yang beriltizam, penulis prolifik, aktivis Islam dan bekas ahli pergerakan Muslim Brotherhood. Memandangkan kepentingan pe...

  10. Al-Biruni and the Mathematical Geography

    OpenAIRE

    Sparavigna, Amelia Carolina

    2014-01-01

    Abu Raihan Al-Biruni (973 - 1048) is considered one of the intellectual giants of humankind. He was an astronomer, physicist and geographer, that distinguished himself as linguist and historian too. Here we discuss his major contributions to the mathematical geography of Middle Ages

  11. Thermodynamics and Kinetics of the Formation of Al2O3/ MgAl2O4/MgO in Al-Silica Metal Matrix Composite

    Science.gov (United States)

    Sreekumar, V. M.; Ravi, K. R.; Pillai, R. M.; Pai, B. C.; Chakraborty, M.

    2008-04-01

    The formation of Al2O3, MgAl2O4, and MgO has been widely studied in different Al base metal matrix composites, but the studies on thermodynamic aspects of the Al2O3/ MgAl2O4/MgO phase equilibria have been limited to few systems such as Al/Al2O3 and Al/SiC. The present study analyzes the Al2O3/MgAl2O4 and MgAl2O4/MgO equilibria with respect to the temperature and the Mg content in Al/SiO2 system using an extended Miedema model. There is a linear and parabolic variation in Mg with respect to the temperature for MgAl2O4/MgO and Al2O3/MgAl2O4 equilibria, respectively, and the influence of Si and Cu in the two equilibria is not appreciable. The experimental verification has been limited to MgAl2O4/MgO equilibria due to the high Mg content (?0.5 wt pct) required for composite processing. The study has been carried out on two varieties of Al/SiO2 composites, i.e., Al/Silica gel and Al/Micro silica processed by liquid metallurgy route (stir casting route). MgO is found to be more stable compared to MgAl2O4 at Mg levels ?5 and 1 wt pct in Al/Silica gel and Al/Micro silica composites, respectively, at 1073 K. MgO is also found to be more stable at lower Mg content (3 wt pct) in Al/Silica gel composite with decreasing particle size of silica gel from 180 micron to submicron and nanolevels. The MgO to MgAl2O4 transformation has taken place through a series of transition phases influenced by the different thermodynamic and kinetic parameters such as holding temperature, Mg concentration in the alloy, holding time, and silica particle size.

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

    Directory of Open Access Journals (Sweden)

    S. Rahman

    2014-01-01

    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.

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

    Science.gov (United States)

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

    2014-09-01

    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).

  14. High noise suppression using magnetically isotropic (CoFe-AlN)/(AlN) multilayer films

    Science.gov (United States)

    Kijima, Hanae; Ohnuma, Shigehiro; Masumoto, Hiroshi; Shimada, Yutaka; Endo, Yasushi; Yamaguchi, Masahiro

    2015-05-01

    Magnetically isotropic (CoFe-AlN)n/(AlN)n+1 multilayer films, in which the number of CoFe-AlN magnetic layers n ranged from 1 to 27, were prepared by radio frequency sputtering to achieve noise suppression at gigahertz frequencies. The soft CoFe-AlN magnetic layers consisted of nanometer-sized CoFe ferromagnetic grains embedded in an insulating AlN amorphous matrix, while the insulating AlN layers comprised AlN columnar crystals. All films showed a similar frequency dependence of permeability and ferromagnetic resonance of 1.7 GHz. Noise suppression was evaluated using a microstrip line as a noise source by determining the in-line conductive loss and the near-field intensity picked up by magnetic field detective probes. High noise suppression effects were observed in every direction in the film plane. Maximum noise suppression values amounted to 60% for the in-line conductive loss and -20 dB for the magnetic near-field intensity at around 1.7 GHz in the 27-layer film. These high-frequency noise suppression levels may be attributed to eddy current losses and ferromagnetic resonance.

  15. Thermoelectric Powers of Cells With NaF-AlF3-Al2O3 Melts

    Science.gov (United States)

    Flem, Belinda E.; Xu, Qian; Kjelstrup, Signe; Sterten, Åsmund

    2001-07-01

    A thermodynamic description of the Peltier heat at the aluminum and the oxygen electrode in the system NaF-AlF3-Al2O3 is given. The thermoelectric power in melts with molar ratios n NaF/n AlF3 from 3.0 to 1.0, saturated with alumina are measured. Seebeck coefficients for molten fluoride electrolytes saturated with alumina, electrolytes that are relevant for aluminum electrowinning electrolysis cells, are reported. The results allow determinations of Peltier heats of aluminum, oxygen and carbon electrodes in NaF-AlF3 electrolytes saturated with alumina. For molar ratios of n NaF/n AlF3 between 2.6 and 1.2, there is a Peltier heating of the aluminum cathode. This heating is in the same order of magnitude as the electrolyte Joule heat, when the current density is 0.7 A cm-2. For molar ratio n NaF/n AlF3 equal to 1.0 the Peltier effect at the aluminum electrode approaches zero. From theoretical considerations we expect a drop also for molar ratio 3.0. For the anode we report a Peltier cooling that is larger than the heat produced by the anodic overvoltage, in melts with NaF/AlF3 molar ratio between 2.6 and 1.2 saturated with alumina.

  16. Stagnation of the exploitation of Al ores and the depression of world prices of Al

    Directory of Open Access Journals (Sweden)

    Slavkovský Jozef

    1999-03-01

    Full Text Available In the contribution, data on Al ? a metal of the 20th century are compiled together with the problems of genesis of the Al mineral raw ma-terials as well as types of bauxite and Al-laterite deposits. Furthermore, an overview of the world exploitation of bauxite during 1935-1980 is given along with the prognoses to 2000 and present situation (1992-1996. Overviews of the production of Al follows, providing its rela-tion to the bauxite exploitation. Contrary to the prognoses, a stabilization or stagnation has been observed in the exploitation of bauxite and production of Al during nineties, which a tendency is directly reflected in the world price of this commodity. When analyzing the Al prices for a longer period, some serious deviations can be noticed, that however presently represent a long-term minimum. We hope the stagnation of the production and the price decline are only temporary and new possibilities of the utilization of Al will be found soon.

  17. Effect of speciation transformation on the coagulation behavior of Al(13) and Al(13) aggregates.

    Science.gov (United States)

    Wu, Xiaohong; Ye, Changqing; Wang, Dongsheng; Ge, Xiaopeng; Tang, Hongxiao

    2009-01-01

    Flocculation of kaolin suspension with aluminium fractal polycations was investigated as a function of aluminium concentration and pH. Aluminium flocculants included Al(13) and Al(13) aggregates with OH/Al ratio of 2.6 and 2.8, respectively. The flocculation kinetics and floc size distribution were monitored by light scattering. The characterization of flocculants showed that the tridecatmer Al(13) and bridged [Al(13)](n) with out-sphere structure were the dominant species for all flocculants in a wide pH range. The coagulation results indicated that the pre and in situ-formed [Al(13)](n) play a key role in removing particles. With the increasing concentration of [Al(13)](n), coagulation mechanisms were transformed from charge-neutralization, electro-patch coagulation to bridge-aggregation. Moreover, sweep-flocculation was involved at higher dosage besides other three mechanisms when amorphous aluminium oxides formed. Hence, chemical interaction between particles and flocculants evolved from surface adsorption to surface precipitation for aluminium polycations by virtue of species transformation. PMID:19237777

  18. Defects associated with nanostructures in AlZnMg and AlCu(Mg) alloys

    International Nuclear Information System (INIS)

    The present work reports on the positron annihilation study addressing the structural and chemical characterization of solute aggregates containing open volumes (vacancies and/or misfit regions at precipitate - matrix interfaces) in AlZnMg, AlCu and AlCuMg alloys. High resolution transmission electron microscopy results for selected aging conditions are also presented. Two main points are discussed: (i) differentiation of the origin of hardening during artificial aging between the AlZnMg and AlCu(Mg) alloy systems, (ii) structural origin of secondary aging at low temperature , after a few minutes of high temperature exposure. It is shown that in AlZnMg alloys hardening at a high temperature is concomitant with the loss of coherency; on the contrary, in AlCu(Mg) alloys hardening is associated with coherent structures. Positron lifetime coincidence Doppler broadening data taken during secondary aging indicate that the residual solute supersaturation leads to the formation of coherent Zn-Mg-v (or Cu-Mg-v) aggregates. (author)

  19. 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)

  20. Calculation of the structure of the Al(331) stepped surface

    International Nuclear Information System (INIS)

    Car-Parinello-like calculations have been used to compute the relaxation of the Al(331) surface, with results that are in remarkable agreement with the low-energy electron-diffraction analysis of Adams and So(?)renson. Rapid screening of the steps on Al(331) is illustrated by comparing its charge density and relaxations to those of Al(110) and Al(111)

  1. Kinetics of the ?-AlFeSi to ?-Al(FeMn)Si transformation in Al-Mg-Si alloys:

    OpenAIRE

    Kuijpers, N.C.W.

    2004-01-01

    Among all the process steps of the production of aluminium extrusion products, the homogenisation of Al-Mg-Si aluminium billets is a very important one, since it gives significant changes in the microstructure of the alloy, leading to an improved extrudability of the material and improved properties of the final extruded product. During this homogenisation process the aluminium billets are annealed in a furnace for a few hours at a temperature of approximately 585 °C. One import...

  2. Ferromagnetic ordering in NpAl2: Magnetic susceptibility and 27Al nuclear magnetic resonance

    Science.gov (United States)

    Martel, L.; Griveau, J.-C.; Eloirdi, R.; Selfslag, C.; Colineau, E.; Caciuffo, R.

    2015-08-01

    We report on the magnetic properties of the neptunium based ferromagnetic compound NpAl2. We used magnetization measurements and 27Al NMR spectroscopy to access magnetic features related to the paramagnetic and ordered states (TC=56 K). While very precise DC SQUID magnetization measurements confirm ferromagnetic ordering, they show a relatively small hysteresis loop at 5 K reduced with a coercive field HCo~3000 Oe. The variable offset cumulative spectra (VOCS) acquired in the paramagnetic state show a high sensitivity of the 27Al nuclei spectral parameters (Knight shifts and line broadening) to the ferromagnetic ordering, even at room temperature.

  3. Conocer y comprender al otro: la comunicación intercultural de Al-Qaeda

    Directory of Open Access Journals (Sweden)

    Evelyn Norma Castro M\\u00E9ndez

    2013-01-01

    Full Text Available La red islamista Al-Qaeda es una de las organizaciones más conocidas en el mundo occidental. En este artículo se presentan los resultados de un análisis discursivo realizado a los mensajes emitidos por la red en el marco de los atentados contra Estados Unidos (2001, Madrid (2004 y Londres (2005, con el fin de responder a las siguientes preguntas: ¿cuál fue el propósito de estos mensajes y qué nos dicen de sus emisores? Al estudiar estos procesos de comunicación intercultural se obtendrán elementos para conocer y comprender al otro más allá de los estereotipos mediáticos que se han construido en su entorno.

  4. DX centers in AlAs and GaAs-AlAs selectively doped superlattices

    OpenAIRE

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

    1991-01-01

    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...

  5. A crystalline oxide passivation for Al2O3/AlGaN/GaN

    Science.gov (United States)

    Qin, Xiaoye; Dong, Hong; Kim, Jiyoung; Wallace, Robert M.

    2014-10-01

    In situ X-ray photoelectron spectroscopy and low energy electron diffraction are performed to study the formation of a crystalline oxide on the AlGaN surface. The oxidation of the AlGaN surface is prepared by annealing and remote N2 + O2 plasma pretreatments resulting in a stable crystalline oxide. The impact of the oxide on the interface state density is studied by capacitance voltage (C-V) measurements. It is found that a remote plasma exposure at 550 °C shows the smallest frequency dispersion. Crystalline oxide formation may provide a novel passivation method for high quality AlGaN/GaN devices.

  6. Superconductivity of Al/Al2O3 interface formed by shock-wave pressure

    Science.gov (United States)

    Palnichenko, A. V.; Shakhrai, D. V.; Avdonin, V. V.; Vyaselev, O. M.; Khasanov, S. S.

    2015-05-01

    A mixture of Al and ? -Al2O3 has been subjected to a shock-wave pressure of ? 170 kbar, followed by vacuum-encapsulating and quenching of the product to liquid nitrogen. The ac magnetic susceptibility measurements of the samples have revealed metastable superconductivity with Tc ? 37 K, characterized by glassy dynamics of the shielding currents below Tc . Comparison of the ac susceptibility and the dc magnetization measurements infers that the superconductivity arises within the interfacial granular layer formed between metallic Al and its oxide due to the shock-wave treatment.

  7. Improvement of Fixing Problems in Lin et al.`s OSPA Protocol

    Directory of Open Access Journals (Sweden)

    Jau-Ji Shen

    2006-01-01

    Full Text Available Recently, Yoon et al. proposed an improved scheme to solve the problems of replay attack and denial of service attack in the Lin et al.`s OSPA scheme. Their scheme can simply update user password, provides mutual authentication between the user and remote server and has more efficient performance by reducing the number of hash operations. In this study, an improved scheme is shown to be vulnerable to the insider attack and smart card loss problem and propose an enhancement of the protocol to solve these problems.

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

    Directory of Open Access Journals (Sweden)

    Srivastava Vishal

    2015-01-01

    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.

  9. Dynamic structure mediated by graphitelike Al nets on the Al2Cu (001) surface

    OpenAIRE

    Serkovic Loli, L.; Gaudry, Emilie; Fourne?e, V.; Weerd, M. -c; Ledieu, J.

    2012-01-01

    A detailed study of the (001) surface of the Al2Cu crystal using both experimental and ab initio computational methods is presented in this work. The combination of both approaches gives many arguments to match the surface plane with a bulk truncated surface model terminated by incomplete Al planes. The missing rows of Al atoms lead to a 2?2×?2R 45° surface reconstruction with two domains rotated by 90° from each other. Ab initio calculations demonstrate that the energetic cost associa...

  10. Precipitation mechanism of Al-substituted tobermorite using hydrothermal reaction

    Science.gov (United States)

    Abe, Kazuki; Maeda, Hirotaka; Ishida, Emile H.

    2010-11-01

    We examined the addition of different crystal phases of alumina (?-Al2O3, ?-Al2O3) to slurries consisting of quartz and slaked lime for synthesis of Al-substituted tobermorite. XRD results showed that Al-substituted tobermorite formed after the reaction. It was clear that two kinds of Al-substituted tobermorite synthesized using different alumina crystal phases shows different morphologies. The difference in the reactivity of the Al2O3 had an influence in the hydrothermal reaction environment. The coordination number and chemical bonding-state of Al caused the different morphology of the tobermorite.

  11. Density of Low-Temperature KF-AlF3 Aluminum Baths with Al2O3 and AlPO4 Additives

    Science.gov (United States)

    Vasková, Zuzana; Kontrík, Martin; Mlynáriková, Jarmila; Bo?a, Miroslav

    2015-02-01

    The density of the KF-AlF3 melts of various KF and AlF3 ratio with Al2O3 and AlPO4 addition has been measured using the Archimedean method. On the basis of the obtained density data the molar volumes of the melts were calculated. These molar volumes decrease with concentration of Al2O3 or AlPO4. In the system containing AlPO4, the relation between cryolite ratios (CRs) vs slopes of molar volume trend lines was identified with excellent correlation factor of R 2 = 0.9844, while in the system containing Al2O3 a discontinuity at CR = 2.5 can be observed.

  12. Cu-AlN INTERFACE : ELECTRONIC STRUCTURE AND ADHESION

    OpenAIRE

    Ohuchi, F.

    1988-01-01

    Adhesion of Cu to AlN has been studied by semi-quantitative adhesion measurements. We show for the first time that the adhesion strength of Cu to AlN is strongly dependent on the AlN surface crystallographic orientations. The origin of the adhesion was attributed to the intrinsic nature of Cu-AlN interactions, where Cu prefers to bond to Al.

  13. Functional applications of Al·Al2O3 nanowires : laser assisted ?-Al2O3 synthesis and fabrication of micro-/nanostructured surfaces for cell compatibility studies

    OpenAIRE

    Aktas, Oral Cenk

    2009-01-01

    In jüngster Zeit konnten eindimensionale (1D) Nanostrukturen beträchtliches Interesse sowohl der Nanowissenschaften als auch der Anwender der Nanotechnologie auf sich ziehen. Insbesondere 1D heterostrukturelle Nanodrähte, kombiniert aus zwei unterschiedlichen Materialien, beispielsweise Metall-Metalloxid-Zusammensetzungen, verfügen über bedeutendes Potential für verschiedenste photonische und elektronische Anwendungen. So bilden die zuerst von Veith et al. beschriebenen Al·Al2O3-Kern-H...

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.)

  15. Behandlung vorwiegend psychisch orientierter, klimakterischer Beschwerden mit der fixen Kombination eines Traubensilberkerzen- und eines Johanniskrautextraktes (Remifemin(R plus

    Directory of Open Access Journals (Sweden)

    Blohmer JU

    2006-01-01

    Full Text Available Außer an klimakterischen Beschwerden mit einem überwiegend vegetativ-vasomotorischen Erscheinungsbild (Hitzewallungen leidet eine große Anzahl von Wechseljahrespatientinnen unter Symptomen mit einer ausgeprägten psychischen Komponente (depressive Verstimmungszustände. Viele klassische Wechseljahrestherapeutika haben oftmals gerade hier eine therapeutische Lücke. So sollte nun im Rahmen einer doppelblinden, randomisierten, placebokontrollierten, klinischen Prüfung an 301 Frauen, die unter klimakterischen Beschwerden mit einer ausgeprägten psychischen Symptomatik litten, die Wirksamkeit der fixen Kombination zweier Extrakte aus Traubensilberkerze (Actaea, syn. Cimicifuga racemosa und Johanniskraut (Hypericum perforatum untersucht werden. Nach einer achtwöchigen Hochdosisphase wurde die Dosis für die restlichen 8 Wochen halbiert. Die klimakterischen Beschwerden wurden anhand der Menopause Rating Scale (MRS-I, die psychischen Beschwerden anhand der Hamilton Depression Scale 17 (HAMD-17 ausgewertet. Im Ergebnis zeigte sich, daß die Verummedikation deutlich wirksamer als Placebo war. Die Gruppendifferenz des MRS-Gesamtscores (0,14 Punkte, 95%-Konfidenzintervall: 0,11?0,17 bzw. 30,4 %-Punkte; Prä/Post-Vergleich fiel signifikant (p 0,001 zugunsten der Verummedikation aus. Der Prä/Post-Vergleich des HAMD-17-Gesamtscores zeigte signifikant (p 0,001 eine Gruppendifferenz von 5,5 Punkten (95%-Konfidenzintervall: 4,6?6,5 Punkte bzw. 29,1 %-Punkte zugunsten der Verummedikation. Somit konnte gezeigt werden, daß die Einnahme der fixen Kombination von Traubensilberkerze und Johanniskraut signifikant und klinisch relevant wirksamer als Placebo ist. Hinsichtlich der Reduktion klimakterischer Beschwerden und besonders zur Behandlung von deren psychischer Komponente stellt sie eine wirksame und gleichzeitig sichere therapeutische Möglichkeit dar.

  16. Vollzug und Sprache Physischer Geographie und die Frage geographischen Takts

    OpenAIRE

    B. Zahnen

    2011-01-01

    Der Aufsatz versteht sich als ein Beitrag zu der sozial- oder kulturwissenschaftlichen Diskussion der Humangeographie um die Möglichkeit der Einbeziehung einer Dimension der Natur bzw. der ?Materialität?, zugleich aber auch als ein theoretischer Entwurf einer ?Physischen Geographie im starken Sinne?, die nicht mehr in dichotomer Entgegensetzung zur Humangeographie zu verstehen ist und die Möglichkeit bietet, genuin geographische Prozesse und Seinswei...

  17. Microstructure and grain growth of nanosized materials

    OpenAIRE

    Rane, Gayatri Koyar

    2012-01-01

    Die einzigartigen Eigenschaften nanokristalliner Materialien waren sowohl aufgrund wissenschaftlichen Interesses, als auch wegen ihrer technologischen Bedeutung seit mehr als zwei Jahrzehnten Gegenstand zahlreicher Forschungsarbeiten. Die extrem hohe Grenzfläche pro Einheitsvolumen von nanokristallinen Materialien hat einen signifikanten Einfluss auf die Eigenschaften dieser Materialien und die beobachteten spezifischen Besonderheiten in den Eigenschaften lassen sich auf die nanokristalline ...

  18. Vom Dämonischen. Zur politischen Medientheorie des Daniel Suarez

    Directory of Open Access Journals (Sweden)

    Alessandro Barberi

    2012-12-01

    Full Text Available Die Romane des Programmierers Daniel Suarez sind weit mehr als reine Fiktionen. Seine terminatorischen Inszenierungen des Endkampfs zwischen Maschinen und Menschen basieren auf äußerst realen Studien zu derzeitigen (Kriegs-Technologien, die als politische Steuerungsmedien eingesetzt werden.This is a review of Daniel Suarez's books Daemon (2009, Darknet (2011 and Kill Decision (2013.

  19. Video storybook reading as a remedy for vocabulary deficits. Outcomes and processes

    OpenAIRE

    Verhallen, Marian J. A. J.; Bus, Adriana G.

    2009-01-01

    Ein erheblicher Prozentsatz der Kinder in niederländischen Kindergärten hat einen so erheblichen Rückstand in der Zweitsprachkompetenz, dass sie kaum von dem als Mittel gegen Vokabeldefizite gepriesenen Lesen von Kinderbüchern profitieren können. Das erste Forschungsziel dieser Studie war zu testen, ob junge Kinder mit eingeschränkter Zweitsprachkompetenz von einem wiederholten Lesen digitaler Geschichten mit integrierten Videosequenzen mehr profitieren als vom Lesen digitaler Geschicht...

  20. Survival of spinoffs and other startups: First evidence for the private sector in Germany, 1976 - 2008

    OpenAIRE

    Fackler, Daniel; Schnabel, Claus

    2013-01-01

    Anhand eines Datensatzes, der 50 Prozent aller Betriebe der deutschen Privatwirtschaft enthält, zeigt diese Studie, dass Spinoffs zum Gründungszeitpunkt größer sind und mehr qualifizierte sowie erfahrene Mitarbeiter beschäftigen als andere Neugründungen. Unter Berücksichtigung dieser und weiterer Faktoren zeigt sich, dass Spinoffs im Vergleich zu anderen Neugründungen höhere Überlebenschancen haben. Die Ergebnisse zeigen sowohl für West- als auch Ostdeutschland sowie für alle unte...

  1. Classical and quantum investigations of four-dimensional maps with a mixed phase space

    OpenAIRE

    Richter, Martin

    2012-01-01

    Für das Verständnis einer Vielzahl von Problemen von der Himmelsmechanik bis hin zur Beschreibung von Molekülen spielen Systeme mit mehr als zwei Freiheitsgraden eine entscheidende Rolle. Aufgrund der Dimensionalität gestaltet sich ein Verständnis dieser Systeme jedoch deutlich schwieriger als bei Systemen mit zwei oder weniger Freiheitsgraden. Die vorliegende Arbeit soll zum besseren Verständnis der klassischen und quantenmechanischen Eigenschaften getriebener Systeme mit zwei Freihe...

  2. Cells of the haemostatic system as targets for pathogenic hantaviruses

    OpenAIRE

    Lütteke, Nina

    2010-01-01

    Hantaviren sind einzelsträngige RNA-Viren, die zur Familie der Bunyaviridae gehören. In den letzten Jahren haben sie immer mehr Aufmerksamkeit als “emerging viruses” auf sich gezogen, welche zunehmend Relevanz als humanpathogene Erreger gewinnen. Sie verursachen, abhängig vom Hantavirustyp, zwei verschiedene Krankheitsbilder: das hämorrhagische Fieber mit renalem Syndrom (HFRS) und das kardiopulmonale Syndrom (HCPS). Beide Syndrome sind mit Veränderungen in der vaskulären Permeabilität, akute...

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

    Index Scriptorium Estoniae

    Paldrok, Al, 1969-

    1998-01-01

    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'

  4. 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)

  5. The Entrepreneurs Characteristic from al-Quran and al-Hadis

    Directory of Open Access Journals (Sweden)

    P. R. M. Faizal

    2013-04-01

    Full Text Available Entrepreneurship is a part of Islamic economics and businesses. Entrepreneurship is the pursuit of opportunity beyond resources controlled. Prophet Muhammad SAW and his companions are examples of this. There are a lot of Muslims that are successful entrepreneurs in the world and Islam always invites all Muslims to be an innovative and active entrepreneurs. Unfortunately, Muslims have lost their confidence, their characters and souls through the time. This research aims to analyse the characteristic of entrepreneurs from al-Quran and al-Sunah. This research also concludes that Islam is not opposite with entrepreneurship. Islam warmly invites all Muslims to be entrepreneurs in their life by given the rules that should be followed by all Muslims which are derive from al-Quran and al-Hadis.

  6. Microstructural Analysis of Al/Al2O3/Gr Powder Composites Produced by Mechanical Alloying

    Directory of Open Access Journals (Sweden)

    Gheorghe Iacob

    2011-09-01

    Full Text Available Powder samples of Al/Al2O3/Gr hybrid composites with different weight percents were obtained by mechanical alloying in a high energy ball mill. The aim of this study is to investigate the effect of alumina and graphite particles content on the microstructure of Al/Al2O3/Gr hybrid composites. Results obtained using Scanning Electron Microscopy (SEM as well as Energy-Dispersive X-ray Spectroscopy (EDS show that the addition of alumina particles as the reinforcement has a drastic effect on the size and morphology of the composite powders. Also, the addition of graphite particles as one of the reinforcing components is presumed to improve tribological properties by forming a graphite-rich lubricant film between the sliding surfaces.

  7. Fabrication and properties of functionally graded NiAl/Al2O3 composites

    Science.gov (United States)

    Miller, D. P.; Lannutti, J. J.; Noebe, R. D.

    1993-01-01

    A modified sedimentation process was used in the production of a functionally gradient material (FGM), NiAl/Al2O3. A simple finite element model was used to guide our design and fabrication efforts by estimating residual stress states as a function of composite structure. This approach could lead to tailored designs that enhance or avoid specific residual stress states. Thermal cycling tests were factored into the model to predict time dependent or steady-state internal temperature and stress profiles. Four-point bend tests were conducted to establish the mechanical load-displacement behavior of a single interlayer FGM at room temperature, 800 and 1000 K. Room temperature bend strength of the FGM was 3-4 times that of the base NiAl. At elevated temperatures, composite fracture occurred in a gradual, noncatastrophic mode involving NiAl retardation of a succession of cracks originating in the alumina face.

  8. Electronic structure and interatomic bonding in Al10V

    International Nuclear Information System (INIS)

    On the basis of ab initio calculations we analysed the electron density distribution in the elementary cell of the compound Al10V. We found covalent bonding between certain atoms. The Al-V bonds of enhanced covalency are linked into -Al-V-Al-V- chains that extend over the whole crystal. The chains intersect at each V site and together form a Kagome network of corner-sharing tetrahedra. The large voids of this network are filled by Z16 Friauf polyhedra consisting of Al atoms only. The skeleton of the Friauf polyhedron has the form of a truncated tetrahedron and consists of 12 strongly bonded Al atoms. These Al-Al bonds also have covalent character. The bonding is dominated by sp2 hybridization. The centre of the Friauf polyhedron may be empty or occupied by an Al atom. The thermodynamic stability of the phase is investigated. The Al21V2 phase with occupied voids is at low temperatures less stable than Al10V. The Al10V structure can be considered as a special case of the Al18Cr2Mg3 structural class. We have found the same picture of bonding as we report here for Al10V for several other aluminium-rich alloys belonging to the Al18Cr2Mg3 structural class also

  9. Geschlecht als Vexierbild? Gender as a Puzzle?

    Directory of Open Access Journals (Sweden)

    Konstanze Plett

    2006-07-01

    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 accomplished work that records and traces the early history of transgendered people in Berlin during the first third of the twentieth century. This history is particularly connected to the name Magnus Hirschfeld, who, till now, has been primarily perceived as a pioneering campaigner for the decriminalization of homosexuality. The author could not have found a more appropriate title for his book than Patterns of Gender (Schnittmuster des Geschlechts.

  10. Foucault y su crítica al humanismo

    Directory of Open Access Journals (Sweden)

    Ignacio B\\u00E1rcenas Monroy

    2007-01-01

    Full Text Available El objetivo del presente trabajo es determinar el significado de la frase ?la muerte del Hombre? en la filosofía contemporánea. Para ello se comienza por dar un panorama general del lugar que ocupa esta reflexión en la filosofía contemporánea. Después se muestra que, a partir de los análisis de Michel Foucault, el hombre es una invención reciente, pues no ha sido una constante en la historia del pensamiento. En seguida se describen aquellos saberes que tienen como objeto de estudio al hombre, mostrando que en lugar de darnos una respuesta sobre lo que éste sea, antes bien lo disuelven, más aún las ciencias humanas producen mecanismos de poder que normalizan a los seres humanos. Se concluye que una reflexión así planteada promueve la indagación de nuevas formas para pensar al ser humano, alejadas de un viejo humanismo.

  11. Homenaje al Dr. Fernando Merino Niño

    Directory of Open Access Journals (Sweden)

    Lisbeth Berrueta

    2013-12-01

    Full Text Available encuentra tu pasión y hazla posible, dale un propósito a tu vida por encima de todo; que la motivación por alcanzar tus metas sea siempre mayor que el temor al fracaso” Anónimo FERNANDO MERINO NINO (1946-2011 DEDICO SU VIDA A SU PASION MÁS GRANDE: LA INVESTIGACION. Nació en España y a los 7 años de edad se mudó con su familia a Caracas, Venezuela, en donde creció y se obtuvo su título de Médico Cirujano a los 22 años de edad, en las aulas de la ilustre Universidad Central de Venezuela (UCV. Posteriormente, continuo su formación académica en Búfalo en el estado de Nueva York, USA, donde obtuvo el grado de Doctor en Ciencias y luego regresa a Venezuela e inicia su carrera como investigador en el Centro de Medicina Experimental del Instituto Venezolano de Investigaciones Científicas (IVIC y paralelamente como profesor de la UCV adscrito al Instituto Anatomopatológico de la Universidad Central de Venezuela. Fernando

  12. Observable Proxies For 26 Al Enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Fryer, Christopher L [Los Alamos National Laboratory; Young, Patrick A [Los Alamos National Laboratory; Ellinger, Carola I [ASU; Arnett, William D [UNIV ARIZONA

    2008-01-01

    We consider the cospatial production of elements in supernova explosions to find observationally detectable proxies for enhancement of {sup 26}Al in supernova ejecta and stellar systems. Using four progenitors we explore a range of 1D explosions at different energies and an asymmetric 3D explosion. We find that the most reliable indicator of the presence of {sup 26}Al in unmixed ejecta is a very low S/Si ratio ({approx} 0.05). Production of N in O/S/Si-rich regions is also indicative. The biologically important element P is produced at its highest abundance in the same regions. Proxies should be detectable in supernova ejecta with high spatial resolution multi wavelength observations, but the small absolute abundance of material injected into a proto-planetary disk makes detection unlikely in existing or forming stellar/planetary systems.

  13. Ni{sub 3}Al technology transfer

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K.; Viswanathan, S.; Santella, M.L. [Oak Ridge National Lab., TN (United States)] [and others

    1997-04-01

    Ductile Ni{sub 3}Al and Ni{sub 3}Al-based alloys have been identified for a range of applications. These applications require the use of material in a variety of product forms such as sheet, plate, bar, wire, tubing, piping, and castings. Although significant progress has been made in the melting, casting, and near-net-shape forming of nickel aluminides, some issues still remain. These include the need for: (1) high-strength castable composition for many applications that have been identified; (2) castability (mold type, fluidity, hot-shortness, porosity, etc.); (3) weld reparability of castings; and (4) workability of cast or powder metallurgy product to sheet, bar, and wire. The four issues listed above can be {open_quotes}show stoppers{close_quotes} for the commercial application of nickel aluminides. This report describes the work completed to address some of these issues during FY 1996.

  14. Countering Al-Qaeda’s Single Narrative

    Directory of Open Access Journals (Sweden)

    Philipp Holtmann

    2013-04-01

    Full Text Available What form should a counter-narrative to al-Qaeda’s single narrative take? Its claim “Islam is under attack” successfully integrates multiple Muslim grievances into one meta-narrative. It has found credibility beyond an extremist fringe of Muslim societies and has been far more successful and attractive than any counter narrative that has been devised so far by Western counter-terrorist strategists. The question if al-Qaeda’s meta-narrative merely creates an external scapegoat for problems that are to a great extent internal to Arab and Muslim societies should be the subject of an intensive, if not heated discussion within the counter-narrative debate.

  15. Corrientes Del Pensamiento En Al-Andalús

    Directory of Open Access Journals (Sweden)

    Montada, Josep Puig

    2007-01-01

    Full Text Available Três tendências principais do pensamento islâmico - a teologia racional, a filosofia e o sufismo - desenvolveram-se na Península Ibérica durante o domínio árabe. Todas elas tiveram origem do leste islâmico e incorporaram pensadores judeus que viviam em al-Andalus. As relações entre essas tendências foram por vezes conflituosas; mas também foram positivas no caso de pensadores que procuraram harmonizar a filosofia e o sufismo (Avempace e Ibn Tufail ou a filosofia e a teologia racional (Averróis e Maimônides. Three main trends of Islamic thought – rational theology, philosophy and Sufism – developed on the Iberian Peninsula during its Arab domination. All three have their origins in the Islamic East and incorporated Jewish thinkers who lived in al-Andalus. The relations among these main trends were often conflictive, but also positive in the case of thinkers who wanted to harmonize philosophy and Sufism (Avempace, Ibn Tufayl or philosophy and rational theology (Averroes, Maimonides.

  16. Impedance measurements of components for the ALS

    International Nuclear Information System (INIS)

    The high current and short bunch length of the ALS beam make the machine susceptible to beam instabilities over a frequency range extending to 13 GHz and beyond. All components of the storage ring have been carefully designed to minimize the impedance presented to the beam, and assemblies have been laid out to avoid resonant enclosures between components. Novel bellows shields allowing considerable mechanical movement while maintaining a low impedance are described. Results are presented of impedance measurements of ALS components and assemblies of components, using a precision coaxial wire technique in frequency domain, extending to frequencies beyond cut-off. All measurements were performed at the Lambertson Beam Electrodynamics Laboratory of the Center for Beam Physics at LBL

  17. Antiferromagnetic behaviour of Tb2Al alloy

    International Nuclear Information System (INIS)

    The structural, thermal and magnetic properties ol the Tb2Al alloy have been investigated by AC/DC magnetic susceptibility, specific heat, X-ray and neutron diffraction measurements. DC and AC-magnetic susceptibility results are consistent with an AFM order at TN = 52 K. The specific heat data show a lambda anomaly associated to the magnetic transition with a peak at 52 K (cord = 99 J/molTbK). The analysis of thermodiffractograms of neutron diffraction patterns indicates that, below the ordering temperature, the magnetic reflections can be indexed with a commensurate lattice related to the crystallographic cell (Pmna) by a propagation vector k = (1/2, 1/2, 1/2). The results are compared with those reported for other magnetic rare earth alloys of R2Al-type (with R = Nd, Gd and Dy).

  18. Status of the AlCap experiment

    CERN Document Server

    Litchfield, R Phillip

    2015-01-01

    The AlCap experiment is a joint project between the COMET and Mu2e collaborations. Both experiments intend to look for the lepton-flavour violating conversion $\\mu + A \\rightarrow e + A$, using tertiary muons from high-power pulsed proton beams. In these experiments the products of ordinary muon capture in the muon stopping target are an important concern, both in terms of hit rates in tracking detectors and radiation damage to equipment. The goal of the AlCap experiment is to provide precision measurements of the products of nuclear capture on Aluminium, which is the favoured target material for both COMET and Mu2e. The results will be used for optimising the design of both conversion experiments, and as input to their simulations. Data was taken in December 2013 and is currently being analysed.

  19. A model of Fe3+-Kaolinite, Al3+-Goethite, Al3+-Hematite equilibria in laterites

    OpenAIRE

    Trolard, F.; Tardy, Yves

    1989-01-01

    Cet article propose un modèle thermodynamique, basé sur un équilibre idéal solide-solution, pour le système Fe2O3-Al2O3-SiO2-H2O prenant en compte les activités de l'eau et de la silice. Le modèle permet de calculer la quantité des phases présentes, les pourcentages de substitution en Al et Fe pour la geothite, l'hématite, la Kaolinite ainsi que la stabilité des phases sous différentes conditions.

  20. From Umm al Qab to Biban al Muluk: The orientation of Royal Tombs in Ancient Egypt

    OpenAIRE

    Belmonte, Juan Antonio; González-García, A. César; Shaltout, Mosalam; Fekri, Magdi; Miranda, Noemi

    2008-01-01

    [EN]This paper presents a preliminary approach to the problem of royal tomb orientation in ancient Egypt from the early dynastic mausoleums at the necropolis of Umm al Qab to the impressive subterranean chambers of the tombs at the Valley of the Kings (Biban al Muluk). This clearly shows that the correct orientation of the monuments, from the earlier mastabas to the later hypogea, was mandatory and that the sky plays a key role in understanding ancient Egyptian funerary monuments.

  1. AlB2 to Laves phase transition in ThAl2 under pressure

    International Nuclear Information System (INIS)

    In the structural map for dialuminides based on Miedema parameters, the compound ThAl2, which crystallizes in the AlB2 structure at ambient conditions, falls in the region of Laves phase (MgCu2) compounds. Using four probe electrical resistance and Be gasketed X-ray diffraction measurements, we have shown that only moderate pressure (?0.3 GPa) is required to transform it to the structure predicted by the structural map. (orig.)

  2. Effect of al content on reaction laser sintering of Ni-Al powder

    OpenAIRE

    Qin L; Hu J; Cui C.; Wang H; Guo Z

    2008-01-01

    Laser reactive sintering, i.e., laser-induced self-propagating reaction sintering synthesis was used for the preparation of nickel aluminide intermetallic compounds. The experimental parameters controlling the ignition step such as ignition time and adiabatic temperature were calculated as a function of initial stoichiometry. Al mole ratio in initial powder mixture was varied from 25% to 50% for controlling adiabatic temperature. The increase in Al powder content resulted in the rise in adiab...

  3. DX centers in AlAs and GaAs-AlAs selectively doped superlattices

    Science.gov (United States)

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

    1991-07-01

    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 E_a = 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 E_cap = 0.36 cV, which locates the DX at E_t? 60 meV below the conduction miniband. Taking into account the measured energies and trap concentrations, we show that the DX observed in the SLs lies in the AlAs layers. Des mesures de spectroscopie capacitives effectuées sur AlAs et sur des super-réseaux (SR) GaAs-AlAs dopés sélectivement et épitaxiés par jets moléculaires montrent que le centre DX a une énergie apparente E_a = 0.42 eV aussi bien dans AlAs que dans les SR. Pour la première fois, une étude de la capture menée sur un SR nous permet de remonter à l'énergie d'activation de la section efficace de capture qui est dans notre cas de 0.36 eV, ce qui positionne le DX à E_t? 60 meV de la minibande de conduction. La nature et la position de DX sont discutées en tenant compte de l'énergie et de la concentration du DX pour chaque structure, et nous montrons que le DX observé est lié au silicium dans les couches AlAs.

  4. Insect herbivores and neighbourhood effects in plant communities of Al Jabal Al Akhdar, Libya

    OpenAIRE

    Abdlrahman,, Abdlrahman Y.A.

    2011-01-01

    Neighbouring plants in the locale of an individual plant may help or hinder it in the task of defence against herbivores, depending on their levels of defence (chemical or physical), and their interactions with potential herbivores. Such ‘neighborhood effects’ are part of the complex network of species interactions that structure ecological communities. This thesis sets out to test whether there are neighbourhood effects on insect herbivory among the plants of the Al Jabal Al Akhdar regio...

  5. Interfaces in AlCu-Al2O3 Metal Matrix Composites Studied by Mechanical Spectroscopy

    OpenAIRE

    Parrini, L.; Schaller, R.

    1996-01-01

    Mechanical spectroscopy has been used for studying the relaxation of the mechanical and thermal stresses, which are built at the fibre-matrix interfaces in AlCu-Al2O3 Metal Matrix Composites (MMCs). The interface strength has been evaluated by the stress dependent damping which exhibits a peak of solid friction. This peak is interpreted as due to interface microcracking. Relaxation of thermal stresses during thermal cycling has been studied by transitory effects which appear at low temperatur...

  6. AlCu-Al2O3 metal matrix composites studied by thermoelectric power measurements

    OpenAIRE

    Parrini, L.; Schaller, R.

    1993-01-01

    Metal matrix composite materials Al-4%Cu reinforced with different volumetric fractions of Al2O3 (Saffil) fibers were produced by "squeeze casting". The composites were characterized by thermoelectric power measurements, in order to identify the effect of the fibers on the precipitation of Cu and the microstructure of the alloy. The formation of Guinier-Preston zones was found to be slowed down by the presence of fibers, while the formation of ?' precipitates was favoured in the composites. ...

  7. Structure formation of AlMg2-AlN composite cast in electromagnetic field

    OpenAIRE

    M. Cholewa; M. Staszewski; M. Soza?ska; B. Formanek

    2007-01-01

    Purpose: Basic material concept, technology and some results of studies on aluminum matrix composite with dispersive aluminum nitride reinforcement was shown. Studied composites were manufactured with use f ex-situ technique and powder metallurgy.Design/methodology/approach: Aluminum nitride powder was manufactured in process of self-evolving high-temperature synthesis SHS. Composite powder Al-AlN was obtained using mechanical alloying. Composite castings were manufactured in stir casting pro...

  8. Magnetism of UPtAl and UIrAl; LDA+U calculations

    International Nuclear Information System (INIS)

    We report on electronic structure calculations of UPtAl and UIrAl ternary uranium based intermetallic compounds. Calculations were performed in the framework of density functional theory using LDA+U exchange correlation potential. Full relaxation of U and J parameters was performed with the aim of obtaining correct total magnetic moments on uranium site. These parameters are then used in subsequent analysis of magnetic moments (including spin and orbital components) and hybridization effects

  9. Mechanical properties of laminated composites of Al 1100/Al 2024 in three aging states

    International Nuclear Information System (INIS)

    Laminated composites consisting of alternating layers of Al 2024 were produced by hot rolling, with a volume fraction of 49% of Al 2024. These composites used in nuclear reactor tecnology, were given under-aging, aging and over-aging heat treatments at 448k for 1h, 4h and 96h, respectively. Tests of microhardness, tension and fatigue in the divider orientation were performed. (Author)

  10. Corrosion of Al-7075 by uranium hexafluoride

    International Nuclear Information System (INIS)

    The results of the Al-7075 corrosion by uranium hexafluoride are presented in this work. The kinetic study shows that corrosion process occurs by two temperature dependent mechanism and that the alloy can be safely used up to 1400C. The corrosion film is formed by uranium oxifluoride with variable composition in depth. Two alternative corrosion models are proposed in order to explain the experimental results, as well as the tests taht will be carried out to confirm one of them

  11. En torno al sentido del dolor

    Directory of Open Access Journals (Sweden)

    Otto D\\u00F6rr Zegers

    2006-01-01

    Full Text Available El dolor y el sufrimiento han acompañado al hombre desde siempre. Lo encontramos en los mitos más antiguos y en el Libro del Génesis. Yahvé le dice a la mujer ?Parirás con dolor? (Cap. 3, Vers. 16 y al hombre, ?Ganarás el pan con el sudor de tu frente? (Cap. 3, Vers. 19 y poco antes le había dicho que de ahora en adelante la vida le daría ?espinas y abrojos? (Cap. 3, Vers. 18. Hay al menos dos tipos de dolores: el dolor-sensación y el dolor-sentimiento (Auersperg. El primero es más localizado, brusco en su aparición y pasa sin dejar huellas. Es el caso del dolor provocado por un pinchazo o una quemadura. El segundo es más difuso y pático, tiene una duración mayor y pasa en forma paulatina. Es el caso de la cefalea, del colon irritable, del dolor de columna, etc. Este tipo de dolor físico abunda en las enfermedades psíquicas, particularmente en la depresión. En sus formas enmascaradas, todo el cuadro gira en torno a la experiencia dolorosa, permaneciendo el compromiso del ánimo y el de los ritmos vitales en una suerte de penumbra. En el dolor es el cuerpo el que duele. En el sufrimiento, en cambio, lo que duele es el significado de lo que me ocurre. Ambos tienen al menos dos rasgos en común: el primero es su carácter pático, vale decir, que nos suceden, que no dependen de nuestra voluntad, y el segundo es que ambos aíslan, interrumpen nuestra relación con el mundo. El autor intenta responder la pregunta por el posible sentido del dolor desde una perspectiva histórica y una hermenéutica...

  12. ?-Synuclein Modification in an ALS Animal Model

    OpenAIRE

    Yang, Eun Jin; Choi, Sun-mi

    2013-01-01

    Amyotrophic lateral sclerosis (ALS) is a progressively paralytic neurodegenerative disease that can be caused by mutations in Cu/Zn-superoxide dismutase 1 (SOD1). Transgenic mice that overexpress mutant SOD1 develop paralysis and accumulate aggregates of mutant protein in the brainstem and spinal cord. Bee venom (BV), which is also known as apitoxin, is extracted from honeybees and is commonly used in oriental medicine for the treatment of chronic rheumatoid arthritis and osteoarthritis. The ...

  13. Combating Al Qaeda's Splinters: Mishandling Suicide Terrorism

    OpenAIRE

    Atran, Scott

    2004-01-01

    The past three years saw more suicide attacks than the last quarter century. Most of these were religiously motivated. While most Westerners have imagined a tightly coordinated transnational terrorist organization headed by Al Qaeda, it seems more likely that nations under attack face a set of largely autonomous groups and cells pursuing their own regional aims. Repeated suicide actions show that massive counterforce alone does not diminish the frequency or intensity of suicide attack. Like p...

  14. Webjihadism : the case of al Qaeda

    OpenAIRE

    Coutinho, Sara

    2012-01-01

    O presente trabalho examina a forma como o terrorismo Islâmico moderno e a al Qaeda em particular utilizam a Internet e as tecnologias dos novos media. Procura identificar e analisar as várias utilizações e determinar em que medida esta presença na Web contribui para a progressão da causa da jihad global. Assente em fontes primárias de especialistas e numa selecção de relatórios de monitorização de sites radicais Islâmicos, a pesquisa identifica e analisa as várias aplicações ...

  15. Al Qaeda as a Tournament: Empirical Evidence

    OpenAIRE

    Caruso, Raul

    2008-01-01

    This short paper aims to find an empirical evidence that al Qaeda behaves as a contest organizer rewarding an indivisible prize – namely, official membership and economic rewards – to candidate extremists groups. Would-be terrorists must then compete with each other to prove their commitment and ability. Hence to maximize their own probability of winning the prize, each group (maximizes its effort) tries to make attacks at least equally destructive as the foregoing attacks. The testable i...

  16. Commissioning experiences of the ALS booster synchrotron

    International Nuclear Information System (INIS)

    Installation of the ALS booster synchrotron proper was completed on April 30, 1991, and commissioning has just begun. Circulating beam around the booster was observed on the first day of operation, May 3, 1991. The beam was visible for about 400 turns. In this paper we describe the status and commissioning experience of the 1.5-GeV electron synchrotron accelerator. 14 refs., 2 figs., 4 tabs

  17. Plasma Spraying of FeAl Intermetalics.

    Czech Academy of Sciences Publication Activity Database

    Mušálek, Radek; Skiba, Tomáš; Ková?ík, O.; Colmenares-Angulo, J.R.

    Vol. Special Issue Part A Workshop 2009. Prague : Czech Technical University in Prague, 2009, s. 174-175. ISBN 978-80-01-04286-1. - (CTU REPORTS). [Workshop 2009. Prague (CZ), 16.02.2009-20.02.2009] Institutional research plan: CEZ:AV0Z20430508 Keywords : plasma spraying * Fe-Al * intermetallics * fatigue testing Subject RIV: JI - Composite Materials http://workshop.cvut.cz/2006/download.php?source=ws2009.pdf

  18. Un camino al éxito: la creatividad

    OpenAIRE

    Luis Carlos Torres Soler

    2011-01-01

    Al conocer un poco la creatividad, vemos inmediatamente que es importante para el mantenimiento de nuestra cultura; luego hay que destinar tiempo para el desarrollo del espíritu creativo. Además, debemos desarrollar el arte del comportamiento persistente y reflexivo, y destinar tiempo suficiente para crecer y florecer. Debemos partir de que la creatividad es un proceso desordenado, que es totalmente personal, que es un viaje a lo desconocido. También hay que destacar que no hay tratado alg...

  19. Problemas psicológicos asociados al trasplante de órganos

    OpenAIRE

    Rez San Gregorio, Mar U. Eda U. C. Ngeles P. U. E.; Edguez, Agust U. Edn Mart U. Edn Rodr U.; Edguez, Antonio Gal U. E. N. Rodr U.

    2005-01-01

    El trasplante de órganos es una alternativa terapéutica para aquellos pacientes que tienen problemas graves en el funcionamiento de un órgano vital: corazón, hígado, pulmón, etc. Dada la relevancia de este tema, en el presente estudio teórico analizamos los principales problemas psicológicos asociados al trasplante de órganos. Concretamente, hemos tenido en cuenta los siguientes apartados: 1) Repercusiones psicológicas del trasplante de órganos en los pacientes: deli...

  20. Manufacturing Al/Mg composite materials

    OpenAIRE

    Neugebauer, Reimund; John, C; Popp, M.

    2011-01-01

    The manufacturing of innovative lightweight materials and their further processing by forming allows functional dimensioning of components in addition to lightweight design. Accordingly, workpieces can be produced that have locally differing component properties. The new lateral extrusion process of composites produces near net shape lightweight composites. This process application is particularly useful when producing corrosion-resistant Al/Mg composites since it facilitates combining the fa...

  1. ?+ depolarization in AlGd alloys

    International Nuclear Information System (INIS)

    The ?+ depolarization rate in dilute AlGd alloys containing 50 and 450 atomic ppm Gd was measured in a transverse field of 80 Oe over the temperature range 6-300 K. For both alloys, ? increased dramatically above 200 K, reaching values of 0.69 and 0.93 ?s-1, respectively, near room temperature. The results are interpreted as providing evidence for a thermally-activated trapping mechanism. (Auth.)

  2. Estado nutricional materno y peso al nacer

    Directory of Open Access Journals (Sweden)

    Marianela de la C Prendes Labrada

    2001-02-01

    Full Text Available Se realizó un estudio analítico de cohorte en el Policlínico "Raúl Gómez" entre enero de 1996 y septiembre de 1997 con el objetivo de relacionar el estado nutricional materno con el peso al nacer. Concluyeron el estudio 305 gestantes en las que se determinó edad, hábito de fumar, peso, talla, valoración ponderal inicial, incremento transgestacional y peso al nacer. Se aplicó Chi cuadrado y se determinó el riesgo relativo. El peso adecuado, el incremento transgestacional de 8 kg o más y la talla > o = 150 cm se asociaron con el peso al nacer > o = 3 000 g. La talla menor de 150 cm, peso bajo III y IV y las fumadoras aportaron con mayor frecuencia recién nacidos con peso entre 2 500 y 2 999 g. El riesgo de bajo peso al nacer fue mayor entre las gestantes con peso bajo I-II-III-IV, con incremento transgestacional menor de 8 kg y en las fumadorasAn analytic cohort study was conducted in "Raúl Gómez" Polyclinic between January, 1996, and September, 1997, aimed at relating the maternal nutritional status with birth weight. Age, smoking habit, weight, height, initial ponderal assessment, transgestational weight gain and birth weight were determined among the 305 pregnant women that concluded the study. The adequate weight, the transgestational weight gain of 8 kg or more and the height > or = 150 cm were associated with a birth weight > or = 3000 g. Women with the lowest height of 150 cm, low weight III and IV and the smokers had more frequently newborn infants between 2 500 and 2 999 g. The low birth weight risk was higher among the expectants with low weight I-II-II-IV, with a transgestational weight gain under 8 kg and among smokers

  3. Kant à la Davidson: Maximen als Proeinstellungen

    OpenAIRE

    Oliver Petersen

    2009-01-01

    Was sind Maximen gemäß Kants Moralphilosophie? Diese Frage entsteht, da Kant zwar eine Explikation von ‚Maxime‘ als ‚subjektives Prinzip des Wollens‘ angibt, diese Explikation aber selbst wieder sehr dunkel bleibt und schwer verständlich ist. Zur Beantwortung dieser Frage werde ich in einem ersten Teil versuchen, plausible Kandidaten dafür zu ermitteln, was unter Maximen zu verstehen ist. Dabei wird sich zeigen, dass Kandidaten, die aus Davidsons Handlungstheorie stammen, sehr gee...

  4. Rolling textures in Al-Mg alloys

    Energy Technology Data Exchange (ETDEWEB)

    Koizumi, M.; Inagaki, H. [Shonan Inst. of Technol., Fujisawa (Japan). Dept. of Mech. Eng.; Kohara, S. [Science Univ. of Tokyo, Noda, Chiba (Japan). Dept. of Materials Science and Technology

    2000-01-01

    In order to clarify the effect of Mg in solid solution on the development of rolling textures in Al, Al-Mg alloys containing Mg up to 9% were quenched into water from the temperature of the solution treatment and cold rolled 95%. Their rolling textures were investigated with the orientation distribution function analysis. It was found that the rolling texture of Al generally became considerably weak with increasing amount of Mg in solution. At Mg content below 3%, {l_brace}123{r_brace} left angle 634 right angle decreased much more rapidly with increasing Mg content than the other two main components of the rolling texture, i.e. {l_brace}112{r_brace} left angle 111 right angle and {l_brace}110{r_brace} left angle 112 right angle. This was ascribed to anisotropic solution hardening. At medium Mg content, i.e. in the range between 3 and 5%, {l_brace}110{r_brace} left angle 112 right angle increased at the expense of {l_brace}112{r_brace} left angle 111 right angle. This was attributed to shear banding which occurred frequently in this range of Mg content. At Mg content above 5%, all main components of the rolling texture were decreased with increasing Mg content significantly, yielding more random rolling textures. Since densities of shear bands were so high, and since interactions and intersections among different variants of shear bands took place frequently, slip rotations resulting in the normal rolling textures were suppressed in Al-high-Mg alloys. (orig.)

  5. Model for metabolic resistance against ALS inhibitors

    Directory of Open Access Journals (Sweden)

    Richter, Otto

    2014-02-01

    Full Text Available Due to herbicide selection pressure metabolic resistance has evolved in many weed species. In this paper we analyse the interaction between the branched chain amino acid (BBC pathway and detoxifying pathways for herbicide breakdown. The four phase detoxification pathway of herbicides comprising the action of P450, GST, glycosyltransferase and ABC transporter is modelled by a system of coupled enzyme kinetic reactions represented by nonlinear differential equations. The herbicide under consideration inhibits the enzyme ALS, which is the key enzyme for the biosynthesis of branched amino acids. For the kinetics of ALS a Monod approach is employed with a binding site for the inhibitor. Synthetic and detoxification pathways are coupled. The model is used to study the production of branched amino acids under the action of ALS inhibitors for different structures and modes of action of the detoxification pathway. The model is capable of generating typical dose response curves and their shift in dependence of the activity pattern of the enzymes of the detoxification pathway of the inhibitor.

  6. al ciudadano: Caso Alcaldía de Maracaibo

    Directory of Open Access Journals (Sweden)

    Norcka Fern\\u00E1ndez-Colina

    2005-01-01

    Full Text Available El objetivo de esta investigación fue explorar la administración de la política de información al ciudadano en la Alcaldía de Maracaibo durante el período 1990-2000, como antecedente a la promulgación de postulados que valorizan la información y sus políticas en la Constitución de 1999. La metodología consistió en la revisión de referentes teóricos, aplicación de un cuestionario semiestructurado a los concejales y personal directivo de la Alcaldía y revisión de documentos de gestión local. Los resultados evidencian que las políticas de información al ciudadano se agrupan en: capacitación, recursos para la gestión de la información, medios de comunicación y mecanismos de participación; el modelo de gestión aplicado fue básicamente burocrático con ciertos visos participativos; en la formulación de las mismas prevaleció la pasividad del ciudadano y en la implementación no se reportaron indicios de seguimiento y control, solo cifras de actividades ejecutadas en las memorias anuales. Se concluye que la administración de políticas de información al ciudadano en el periodo estudiado, no representó una tarea prioritaria sino un complemento del resto de las políticas existentes en otros sectores.

  7. An ALS [Advanced Light Source] handbook

    International Nuclear Information System (INIS)

    This booklet aims to provide the prospective user of the Advanced Light Source with a concise description of the radiation a researcher might expect at his or her experimental station. The focus is therefore on the characteristics of the light that emerges from insertion devices and bending magnets and on how components of the beam lines further alter the properties of the radiation. The specifications and operating parameters of the ALS injection system and storage ring are of only peripheral interest. To this end, Sections 3 and 5 and most of Section 4 are devoted to summary presentations, by means of performance plots and tabular compilations, of radiation characteristics at the ALS--spectral brightness, flux, coherent power, resolution, time structure, etc.--assuming a representative set of four undulators and one wiggler and a corresponding set of five beam lines. As a complement to these performance summaries, Section 1 is a general introductory discussion of synchrotron radiation and the ALS, and Section 2 provides a compendious introduction to the characteristics of synchrotron radiation from bending magnets, wigglers, and undulators. In addition, Section 4 briefly introduces the theory of diffraction grating and crystal monochromators. 15 refs., 28 figs., 5 tabs

  8. Studies on Al Kidirate and Kapoeta meteorites

    International Nuclear Information System (INIS)

    Moessbauer spectroscopy (20-300 K), magnetic susceptibility measurements (77-350 K), scanning electron microscopy and X-ray diffraction experiments have been performed on two meteorite samples: one from an old fall (Kapoeta) and another from a very recent fall (Al Kidirate). The two specimens differ in their mineralogy. Chondrules appear to be absent in Kapoeta and it is probably a pyroxene-plagioclase achondrite with ferrohypersthene as the most abundant mineral. On the other hand, the Al Kidirate meteorite is an ordinary chondrite and the specimen consists of olivine, orthopyroxene, troilite and kamacite. The Moessbauer measurements confirm the above characterization, showing a paramagnetic doublet for the Kapoeta sample and at least two paramagnetic doublets and magnetic sextets for the Al Kidirate specimens. The former were assigned to Fe in pyroxene sites, while the latter was assigned to Fe in pyroxene, olivine, Fe-S and Fe-Ni alloys. The difference in the mineralogy of the two meteorites has also been reflected in the temperature-dependent magnetic susceptibility. The magnetization and the hyperfine interaction parameters will be discussed in relation to the mineralogy. (orig.)

  9. Tolerancia al co en celdas de combustible

    Directory of Open Access Journals (Sweden)

    BIBIAN HOYOS

    2008-01-01

    Full Text Available El entendimiento completo del proceso de adsorción y posterior oxidación de moléculas de CO en platino es de fundamental importancia para el desarrollo de celdas de combustible poliméricas que operan a baja temperatura. En este trabajo se presenta una revisión de las cinco estrategias experimentales más importantes en la búsqueda de mejorar la tolerancia al CO: disminución del potencial de inicio de la reacción de oxidación, reducción de la cantidad de CO adsorbido, utilización de pequeñas cantidades de oxígeno en la corriente de alimentación al ánodo, aumento de la temperatura de operación y limpieza del CO a la entrada. Aunque se han desarrollado catalizadores bastante promisorios (PtMo y PdAu, todavía se sigue considerando a la mezcla Pt-Ru como el catalizador anódico más eficiente para combustibles que contienen 10 ppm de CO o más. La estrategia de inyectar oxígeno al ánodo parece promisoria pero requiere el desarrollo de nuevas membranas más resistentes y de la implementación de condiciones más seguras de operación de la celda. El diseño estructural de ánodos especiales con múltiples capas soportando catalizadores específicos para cada tipo de combustible puede ser una estrategia muy atractiva.

  10. Aberrant immunoglobulin synthesis in AL amyloid

    International Nuclear Information System (INIS)

    Bone marrow cells obtained from 13 patients with biopsy documented AL disease were incubated in short term culture with radioactive amino acids. Immunologic precipitation of cytoplasm and secreted material was performed and the precipitates analyzed on SDS containing polyacrylamide gels. All the patients synthesized excess free light chains and light chain dimers. In addition, 8 of 13 patients synthesized molecules smaller than intact light chains which were precipitable with anti-L-chain constant region sera. Two of thirteen patients synthesized heavy chain fragments. These data show that some patients with AL disease synthesize L-chain fragments and suggest that these aberrant synthetic products may play a role in the pathogenesis of AL deposition. Over the last decade investigation of the amyloidoses has been dominated by the identification and structural analysis of fibrillar material in tissue deposits by either immunologic or biochemical techniques. The rewards of these approaches are apparent with six (at last count) distinct molecules being identified as the major fibrillar components of hereditary acquired and local forms of the disease (1). In addition, by inference, physiologically soluble proteins which are related to the fibrillar material have been implicated as precursors of the fibrils. Experimentally however, the steps whereby the soluble presumed precursors are transformed into the insoluble fibrillar deposits have been difficult to define. For the ms have been difficult to define. For the moment it appears that both different precursors and different mechanisms of biogenesis may be discovered for each of the amyloid diseases

  11. Mortalidad atribuible al alcohol en Cataluña: 1994

    Directory of Open Access Journals (Sweden)

    Alsedá Graells Miquel

    1998-01-01

    Full Text Available FUNDAMENTO: El objetivo de este estudio es evaluar la contribución del consumo de alcohol a la mortalidad en Cataluña durante 1994, así como su contribución a las muertes prematuras. MÉTODOS: En este estudio se han utilizado los datos de las causas de muerte en Cataluña durante 1994 del Servei d'Informació i Estudis de la Direcció General de Recursos Sanitaris del Departament de Sanitat i Seguretat Social de Catalunya. Las fracciones atribuibles al alcohol están basadas en las utilizadas en el estudio de la mortalidad relacionada con el alcohol en Estados Unidos en 1987. RESULTADOS: El 5,3% de las muertes en Cataluña durante 1994 estuvieron relacionadas con el consumo de alcohol. Esta mortalidad fue del 6,5% entre los hombres y del 3,9% entre las mujeres. La categoría diagnóstica que más contribuyó al número de muertes fue la de las neoplasias malignas (29,3%. El estudio de las muertes prematuras muestra que los accidentes no intencionales son la causa más importante (52,3%. En esta categoría diagnóstica los accidentes con vehículos a motor son los principales responsables de los años potenciales de vida perdidos (APVP. La media de APVP por cada muerte atribuible al alcohol hasta la edad de 65 fue de 7,5. CONCLUSIONES: Este estudio muestra la magnitud que tiene el alcohol como problema de salud pública en Cataluña.

  12. Fabrication and Characterization of Al/p-CuInAlSe2 Thin Film Schottky Diodes

    Directory of Open Access Journals (Sweden)

    Usha Parihar

    2013-05-01

    Full Text Available Al/p-CuInAlSe2 polycrystalline schottky diodes fabricated by flash evaporation method were undertaken for their electrical analysis at room temperature. Diode parameters of the undertaken diodes were then derived from the current-voltage (I-V as well as capacitance-voltage (C-V characteristics. It has been observed that the schottky barrier height deduced from the room temperature I-V is lower to that obtained from the C-V characteristics and is attributed to the fact that I-V analysis includes both the image force and dipole lowering effects and is also reduced by the tunneling and leakage currents. The slope variation of the frequency dependent C – 2-V characteristics for the Al/p-CuInAlSe2 Schottky diode at varying frequency values from 50 kHz to 1 MHz suggests a large density of slow traps or interface states at the M-S junction. As emerging from the parameters values energy band diagram of Al and P-CuInAlSe2 has been reconstructed.

  13. Structure and stability of Al2Fe and Al5Fe2

    Science.gov (United States)

    Widom, Michael; Mihalkovic, Marek

    2012-02-01

    We employ first principles total energy and phonon calculations to address the structure and stability of Al2Fe and Al5Fe2. The observed structure of Al2Fe, which is reported as stable in the assessed Al-Fe phase diagram, is distinguished by an unusually low triclinic symmetry. The initial crystallographic structure determination additionally featured an unusual hole large enough to accommodate an additional atom. Our calculations indicate the hole must be filled, but predict the triclinic structure is unstable relative to a simpler tetragonal structure based on the prototype Mo Si2. This tetragonal structure is interesting because it is predicted to be nonmagnetic, electrically insulating and high density, while the triclinic structure is magnetic, metallic and low density. We reconcile this seeming contradiction by demonstrating a high vibrational entropy that explai ns why the triclinic structure is stable at high temperatures. Finally, we note that orthorhombic Al5Fe2 is also destabilized by the tetragonal structure but may be stabilized at high temperatures, again by vibrational entropy and partial occupancy associated with the diffusion of Al atoms along channels.

  14. Room Temperature Radiolytic Synthesized Cu@CuAlO2-Al2O3 Nanoparticles

    Science.gov (United States)

    Abedini, Alam; Saion, Elias; Larki, Farhad; Zakaria, Azmi; Noroozi, Monir; Soltani, Nayereh

    2012-01-01

    Colloidal Cu@CuAlO2-Al2O3 bimetallic nanoparticles were prepared by a gamma irradiation method in an aqueous system in the presence of polyvinyl pyrrolidone (PVP) and isopropanol respectively as a colloidal stabilizer and scavenger of hydrogen and hydroxyl radicals. The gamma irradiation was carried out in a 60Co gamma source chamber with different doses up to 120 kGy. The formation of Cu@CuAlO2-Al2O3 nanoparticles was observed initially by the change in color of the colloidal samples from colorless to brown. Fourier transform infrared spectroscopy (FTIR) confirmed the presence of bonds between polymer chains and the metal surface at all radiation doses. Results of transmission electron microscopy (TEM), energy dispersive X-ray spectrometry (EDX), and X-ray diffraction (XRD) showed that Cu@CuAlO2-Al2O3 nanoparticles are in a core-shell structure. By controlling the absorbed dose and precursor concentration, nanoclusters with different particle sizes were obtained. The average particle diameter increased with increased precursor concentration and decreased with increased dose. This is due to the competition between nucleation, growth, and aggregation processes in the formation of nanoclusters during irradiation. PMID:23109893

  15. Room Temperature Radiolytic Synthesized Cu@CuAlO2-Al2O3 Nanoparticles

    Directory of Open Access Journals (Sweden)

    Alam Abedini

    2012-09-01

    Full Text Available Colloidal Cu@CuAlO2-Al2O3 bimetallic nanoparticles were prepared by a gamma irradiation method in an aqueous system in the presence of polyvinyl pyrrolidone (PVP and isopropanol respectively as a colloidal stabilizer and scavenger of hydrogen and hydroxyl radicals. The gamma irradiation was carried out in a 60Co gamma source chamber with different doses up to 120 kGy. The formation of Cu@CuAlO2-Al2O3 nanoparticles was observed initially by the change in color of the colloidal samples from colorless to brown. Fourier transform infrared spectroscopy (FTIR confirmed the presence of bonds between polymer chains and the metal surface at all radiation doses. Results of transmission electron microscopy (TEM, energy dispersive X-ray spectrometry (EDX, and X-ray diffraction (XRD showed that Cu@CuAlO2-Al2O3 nanoparticles are in a core-shell structure. By controlling the absorbed dose and precursor concentration, nanoclusters with different particle sizes were obtained. The average particle diameter increased with increased precursor concentration and decreased with increased dose. This is due to the competition between nucleation, growth, and aggregation processes in the formation of nanoclusters during irradiation.

  16. Room Temperature Radiolytic Synthesized Cu@CuAlO(2)-Al(2)O(3) Nanoparticles.

    Science.gov (United States)

    Abedini, Alam; Saion, Elias; Larki, Farhad; Zakaria, Azmi; Noroozi, Monir; Soltani, Nayereh

    2012-01-01

    Colloidal Cu@CuAlO(2)-Al(2)O(3) bimetallic nanoparticles were prepared by a gamma irradiation method in an aqueous system in the presence of polyvinyl pyrrolidone (PVP) and isopropanol respectively as a colloidal stabilizer and scavenger of hydrogen and hydroxyl radicals. The gamma irradiation was carried out in a (60)Co gamma source chamber with different doses up to 120 kGy. The formation of Cu@CuAlO(2)-Al(2)O(3) nanoparticles was observed initially by the change in color of the colloidal samples from colorless to brown. Fourier transform infrared spectroscopy (FTIR) confirmed the presence of bonds between polymer chains and the metal surface at all radiation doses. Results of transmission electron microscopy (TEM), energy dispersive X-ray spectrometry (EDX), and X-ray diffraction (XRD) showed that Cu@CuAlO(2)-Al(2)O(3) nanoparticles are in a core-shell structure. By controlling the absorbed dose and precursor concentration, nanoclusters with different particle sizes were obtained. The average particle diameter increased with increased precursor concentration and decreased with increased dose. This is due to the competition between nucleation, growth, and aggregation processes in the formation of nanoclusters during irradiation. PMID:23109893

  17. Reactive HIPIMS with auxiliary Al electrode for ZnO:Al thin film deposition

    International Nuclear Information System (INIS)

    In this paper a new technique is proposed for precise doping control of ZnO:Al thin films deposited in reactive High Power Impulse Magnetron Sputtering (HIPIMS). An auxiliary aluminum electrode was added to a reactive Ar/O2 pulsed magnetron with planar Zn target in order to obtain a controlled doping of ZnO films. Al neutral density in gas phase has been controlled by the discharge current and the biasing voltage on the auxiliary electrode (which influence the ion bombardment of the electrode) and measured by laser resonant absorption spectroscopy. The fraction of Al dopant in the deposited films was estimated by X-ray Photoelectron Spectroscopy (XPS) measurements. The goal of this work was to correlate Al density measured in the gas phase with Al concentration in the deposited films. It was also investigated the effect of the aluminum concentration on the structural, electrical and optical properties of ZnO:Al thin films deposited by HIPIMS. The internal microstructure and chemical composition of the deposited films was examined by X-ray difractometry (XRD) and X-ray Photoelectron Spectroscopy (XPS). The optical properties of the deposited films were studied by UV/VIS and photoluminescence spectroscopy.

  18. A comparative wear study on Al-Li and Al-Li/SiC composite

    Energy Technology Data Exchange (ETDEWEB)

    Okumus, S. Cem, E-mail: cokumus@sakarya.edu.tr; Karslioglu, Ramazan, E-mail: cokumus@sakarya.edu.tr; Akbulut, Hatem, E-mail: cokumus@sakarya.edu.tr [Sakarya University Engineering Faculty, Department of Metallurgical and Materials Engineering, Esentepe Campus, 54187, Sakarya (Turkey)

    2013-12-16

    Aluminum-lithium based unreinforced (Al-8090) alloy and Al-8090/SiCp/17 vol.% metal matrix composite produced by extrusion after spray co-deposition. A dry ball-on disk wear test was carried out for both alloy and composite. The tests were performed against an Al{sub 2}O{sub 3} ball, 10 mm in diameter, at room temperature and in laboratory air conditions with a relative humidity of 40-60%. Sliding speed was chosen as 1.0 ms{sup ?1} and normal loads of 1.0, 3.0 and 5.0 N were employed at a constant sliding distance of 1000 m. The wear damage on the specimens was evaluated via measurement of wear depth and diameter. Microstructural and wear characterization was carried out via scanning electron microscopy (SEM). The results showed that wear loss of the Al-8090/SiC composite was less than that of the Al-8090 matrix alloy. Plastic deformation observed on the wear surface of the composite and the matrix alloy, and the higher the applied load the greater the plastic deformation. Scanning electron microscopy examinations of wear tracks also reveal that delamination fracture was the dominant wear mechanism during the wear progression. Friction coefficient was maximum at the low applied load in the case of the Al-8090/SiC composite while a gradual increase was observed with applied load for the matrix alloy.

  19. A comparative wear study on Al-Li and Al-Li/SiC composite

    Science.gov (United States)

    Okumus, S. Cem; Karslioglu, Ramazan; Akbulut, Hatem

    2013-12-01

    Aluminum-lithium based unreinforced (Al-8090) alloy and Al-8090/SiCp/17 vol.% metal matrix composite produced by extrusion after spray co-deposition. A dry ball-on disk wear test was carried out for both alloy and composite. The tests were performed against an Al2O3 ball, 10 mm in diameter, at room temperature and in laboratory air conditions with a relative humidity of 40-60%. Sliding speed was chosen as 1.0 ms-1 and normal loads of 1.0, 3.0 and 5.0 N were employed at a constant sliding distance of 1000 m. The wear damage on the specimens was evaluated via measurement of wear depth and diameter. Microstructural and wear characterization was carried out via scanning electron microscopy (SEM). The results showed that wear loss of the Al-8090/SiC composite was less than that of the Al-8090 matrix alloy. Plastic deformation observed on the wear surface of the composite and the matrix alloy, and the higher the applied load the greater the plastic deformation. Scanning electron microscopy examinations of wear tracks also reveal that delamination fracture was the dominant wear mechanism during the wear progression. Friction coefficient was maximum at the low applied load in the case of the Al-8090/SiC composite while a gradual increase was observed with applied load for the matrix alloy.

  20. UV photoluminescence spectroscopy of AlGaN alloys with different Al-contents

    Energy Technology Data Exchange (ETDEWEB)

    Reich, Christoph; Schlegel, Jessica; Stellmach, Joachim; Vogt, Patrick; Kneissl, Michael [Technische Universitaet Berlin, Institut fuer Festkoerperphysik, Hardenbergstr. 36, 10623 Berlin (Germany)

    2011-07-01

    AlGaN alloys are very promissing materials for ultraviolet (UV) light emitting diodes and lasers in the spectral range between 360 nm and 200 nm. However, for high efficiency devices further improvement of material quality and better understanding of the optical properties is needed. In order to investigate the influence of the composition and defect density on the emission characteristics we have characterized AlGaN layers with different Al-content using temperature dependent and excitation power dependent UV photoluminescence (PL) spectroscopy. The samples were grown by metalorganic vapor phase epitaxy either on (0001) GaN/sapphire or on (0001) AlN/sapphire to minimize lattice mismatch within the entire composition range. We observe a decrease in the PL intensity and an increase in the full width at half maximum with higher Al-content, which can be attributed to a reduction of the crystal quality as well as an increase in composition fluctuation. The emission characteristics and the temperature dependence of the bandgap energy for different AlGaN compositions are discussed.

  1. A comparative wear study on Al-Li and Al-Li/SiC composite

    International Nuclear Information System (INIS)

    Aluminum-lithium based unreinforced (Al-8090) alloy and Al-8090/SiCp/17 vol.% metal matrix composite produced by extrusion after spray co-deposition. A dry ball-on disk wear test was carried out for both alloy and composite. The tests were performed against an Al2O3 ball, 10 mm in diameter, at room temperature and in laboratory air conditions with a relative humidity of 40-60%. Sliding speed was chosen as 1.0 ms?1 and normal loads of 1.0, 3.0 and 5.0 N were employed at a constant sliding distance of 1000 m. The wear damage on the specimens was evaluated via measurement of wear depth and diameter. Microstructural and wear characterization was carried out via scanning electron microscopy (SEM). The results showed that wear loss of the Al-8090/SiC composite was less than that of the Al-8090 matrix alloy. Plastic deformation observed on the wear surface of the composite and the matrix alloy, and the higher the applied load the greater the plastic deformation. Scanning electron microscopy examinations of wear tracks also reveal that delamination fracture was the dominant wear mechanism during the wear progression. Friction coefficient was maximum at the low applied load in the case of the Al-8090/SiC composite while a gradual increase was observed with applied load for the matrix alloy

  2. The Gendering of «Death» in Kit?b al-‘Iqd al-Far?d

    Directory of Open Access Journals (Sweden)

    El Cheikh, Nadia Maria

    2010-12-01

    Full Text Available This article studies a subsection of the adab compilation of Ibn ‘Abd Rabbih’s, al-‘Iqd al-far?d, namely “The Book of Lamentations, Condolences, and Elegies”. The article analyzes al-‘Iqd’s ideological function, specifically, the way gender is organized through the occasion of death. It locates what seems to be «repressed» in the text attempting to determine what material was ignored, buried, end edited, and how priorities were arranged. It is the contention of this article that al-‘Iqd, as an exemplary text, not only reflects a dominant ideology, but contributes towards the dominant discourse by shaping mental and social life.

    Este artículo estudia la sección de la recopilación de adab del ‘Iqd al-far?d de Ibn ‘Abd Rabbih llamada “El Libro de Lamentaciones, Condolencias y Elegías”. Se analiza la función ideológica del ‘Iqd, concretamente la manera en que se organiza el género con ocasión de la muerte. Localiza lo que parece haberse «reprimido» en el texto en un intento por determinar el material que fue pasado por alto, enterrado o alterado, y estudia la organización de sus prioridades. El artículo sostiene que el ‘Iqd, en su función de texto ejemplar, no se limita a reflejar una ideología dominante sino que hace una contribución al discurso dominante por su manera de dar forma a la vida intelectual y social.

  3. Comportamiento productivo y reproductivo al parto y al destete en cerdas de siete líneas genéticas

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Garc\\u00EDa-Mungu\\u00EDa

    2014-01-01

    Full Text Available El objetivo del estudio fue evaluar los efectos de línea genética (LG, número de parto (NP y sala de parto (S en el tamaño de la camada nacida viva (TCNV, el número de lechones nacidos muertos por camada (LNM, e l tamaño de la camada al nacimiento (TCN y al destete (TCD, los pesos de la camada al nacimiento (PCN y al destete (PCD, el consumo diario de alimento de la cerda (CDA y las pérdidas de peso (PPL y grasa dorsal (PGD de la cerda en la lactancia. Además de los efectos fijos LG, NP y S, el modelo incluyó las covariables TCN para PCN y TCD para PCD. Se encontraron diferencias ( P< 0.0026 entre LG para TCN, TCNV, LNM y CDA. El NP sólo fue significativo ( P <0.0001 para CDA, S sólo lo fue ( P< 0.0380 para LNM. Las cerdas de tres o más partos tuvieron mayor CDA (4.5 ± 0.2 kg que las de primero o segundo partos (3.4 ± 0.2 kg. Se requiere reforzar la atención al parto y dura nte la lactancia para reducir la muerte de lechones al parto y en la lactancia; así como evitar que la cerda pierda d emasiado peso y grasa dorsal con el fin de reducir el deterioro del comportamiento productivo y reproductivo postd estete.

  4. Softening Kinetics in High Al and High Al-Nb-Microalloyed Steels

    Science.gov (United States)

    Pereda, B.; Aretxabaleta, Z.; López, B.

    2015-03-01

    Double-hit torsion tests were performed in order to study the effect of high Al levels (up to 2 wt.%) and Nb microalloying (up to 0.07 wt.%) on the static softening kinetics of 0.2%C-2%Mn steels. The addition of 1%Al leads to a delay in the softening kinetics due to solute-drag effect, equivalent to that exerted by 0.027%Nb. For the 2%Al steels, at temperatures below 1000 °C, ? ? ? phase transformation occurs after deformation, resulting in a larger retardation of the softening kinetics. At temperatures higher than 1000 °C, Nb in solid solution also contributes to the retardation of the static softening kinetics, and at lower temperatures NbC strain-induced precipitation leads to incomplete softening for the 1%Al steel, and to a complex interaction between softening, phase transformation, and NbC strain-induced precipitation for the 2%Al-Nb steels. The effect of Al on the static softening kinetics was quantified and introduced in a model developed in previous works for the prediction of the austenite microstructural evolution. In order to validate the results of the model, multipass torsion tests were carried out at conditions representative of hot strip and plate rolling mills. Model predictions show reasonable agreement with the results obtained at different deformation conditions.

  5. Study of strain softening behavior of Al-Al3Sc multilayers using microcompression testing

    International Nuclear Information System (INIS)

    Multilayer thin films with bilayer thicknesses in the nanometer range have been reported to have very high strengths. A previous study has shown that Al-Al3Sc multilayers, with bilayer thicknesses as small as 6 nm, have hardnesses as high as ?3 GPa as measured by sharp tip nanoindentation. In the present study, we have avoided some of the complications associated with sharp tip nanoindentation by directly measuring the yield strengths and strain hardening/softening properties of Al-Al3Sc multilayers using microcompression testing methods with a nanoindenter. The results show the expected trend of increasing yield strength with decreasing bilayer thickness, and compare favorably with estimates of the yield strengths based on sharp tip nanoindentation. During deformation, the Al-Al3Sc multilayer pillars with smaller bilayer spacings experience considerable strain softening, resulting in a 'flat-top mushroom' shape after deformation. We have developed a numerical model to account for this inhomogeneous deformation behavior and to calculate stress-strain relationships during strain softening. A new transmission electron microscopy study of a deformed pillar shows that the softening is a result of destruction of the layered structure due to shearing and rotation.

  6. Cross resistance to herbicides of five ALS-inibiting groups and sequencing of the ALS gene in Cyperus difformis L

    OpenAIRE

    Ferrero, Aldo; Vidotto, Francesco

    2009-01-01

    Resistance to ALS-inhibiting herbicides in Cyperus difformis has evolved rapidly in many rice areas worldwide. This study identified the mechanism of resistance, assessed cross-resistance patterns to all five chemical groups of ALS-inhibiting herbicides in four C. difformis biotypes, and attempted to sequence the ALS gene. Whole-plant and ALS enzyme activity dose-response assays indicated that the WA biotype was resistant to all ALS-inhibiting herbicides evaluated. The IR biotype was resistan...

  7. Neue Techniken in der Neurorehabilitation

    Science.gov (United States)

    Riener, Robert

    Zentralmotorische Lähmungen durch Schädigungen im Hirn oder Rückenmark stellen weltweit ein großes sozialmedizinisches Problem dar. In Deutschland treten mehr als 250.000 neue Schlaganfälle pro Jahr auf. Zudem leben in Deutschland mehr als 40.000 Menschen mit Querschnittlähmung. Dazu kommen Patienten mit Schädel-Hirn-Trauma, Zerebralparesen, Multipler Sklerose, Parkinson oder Entzündungen und Tumoren des zentralen Nervensystems. Solche zentralmotorische Pathologien können durch manuelle oder automatisierte Bewegungstherapien erfolgreich behandelt werden. Dabei wird durch ein häufiges, repetitives Bewegen von Körpersegmenten die Lern- und Anpassungsfähigkeit des Gehirns und Rückenmarks genutzt. Ist eine Heilung oder Behandlung nicht mehr möglich, so können zahlreiche Techniken dazu beitragen, Bewegungsfunktionen zu unterstützen, so dass die Patienten alltägliche Aktivitäten normal ausführen können und in die Gesellschaft reintegriert werden.

  8. Regulation of the Bacillus subtilis alsS, alsD, and alsR genes involved in post-exponential-phase production of acetoin.

    OpenAIRE

    Renna, M. C.; Najimudin, N.; Winik, L. R.; Zahler, S. A.

    1993-01-01

    Acetoin is a major extracellular product of Bacillus subtilis grown on glucose and other fermentable carbon sources. The enzymes responsible for the formation of acetoin, acetolactate synthase, and acetolactate decarboxylase are synthesized in detectable amounts only in cells that have reached stationary phase. We have cloned and sequenced the genes encoding these enzymes, alsS and alsD, as well as a gene, alsR, that regulates their expression. alsS and alsD appear to compose a single operon,...

  9. Effect of the composition of Al-Li alloys on the quantitative relation between the ?'(Al3Li), S1(Al2MgLi), and T1(Al2CuLi) phases

    Science.gov (United States)

    Betsofen, S. Ya.; Antipov, V. V.; Grushin, I. A.; Knyazev, M. I.; Khokhlatova, L. B.; Alekseev, A. A.

    2015-01-01

    Al-Li alloys are considered. A quantitative approach to the determination of the ratio of the fractions of the binary and ternary intermetallic phases in Al-Mg(Cu)-Li alloys is developed on the basis of chemical and phase composition balance equations and the experimentally measured lattice parameter of the ? solid solution. The ratio of the fractions of the ?'(Al3Li) and S1(T1) phases in Al-Mg(Cu)-Li alloys is shown to be determined by the ratio of the mole fractions of Li and Mg(Cu). Equations are proposed for calculating the weight fractions of the S1(Al2MgLi), T1(Al2CuLi) and ?'(Al3Li) phases in domestic and foreign Al-Mg-Li alloys 1420, 1424, 5090 and Al-Cu-Li alloys 1440, 1460, 1461, 1441, 1469, 2090, 2095, 8090, and Weldalite 049.

  10. Pure AlN layers in metal-polar AlGaN/AlN/GaN and AlN/GaN heterostructures grown by low-temperature ammonia-based molecular beam epitaxy

    Science.gov (United States)

    Kaun, Stephen W.; Mazumder, Baishakhi; Fireman, Micha N.; Kyle, Erin C. H.; Mishra, Umesh K.; Speck, James S.

    2015-05-01

    When grown at a high temperature (820 °C) by ammonia-based molecular beam epitaxy (NH3-MBE), the AlN layers of metal-polar AlGaN/AlN/GaN heterostructures had a high GaN mole fraction (?0.15), as identified by atom probe tomography in a previous study (Mazumder et al 2013 Appl. Phys. Lett. 102 111603). In the study presented here, growth at low temperature (improved purity of the AlN layers grown at low temperature was correlated to a dramatic increase in the sheet density of the two-dimensional electron gas (2DEG) at the AlN/GaN heterointerface. Through application of an In surfactant, metal-polar AlN(3.5 nm)/GaN and AlGaN/AlN(2.5 nm)/GaN heterostructures grown at low temperature yielded low 2DEG sheet resistances of 177 and 285 ?/?, respectively.

  11. The Calculation of Fe-Al-O Interaction Coefficient

    International Nuclear Information System (INIS)

    Aluminum is a very common deoxidizer in steel-making processes. The solubility of oxygen in molten iron decreases with increasing aluminum content. For the deoxidation process, the solubility of oxygen in Fe-Al melts decreases with increasing aluminum content. When %Al is increased to 0.34 wt.%, %O decreases to 6.4 ppm, which is the lowest point of the FeAl2O4 curve. Then the Al2O3 curve appears and replaces the FeAl2O4 curve, where the interconnection point of the two curves is the coexistence point of FeAl2O4 and Al2O3 phases. When %Al is increased to 0.4%, the %O decreases to 6.35 ppm, which is the lowest point of the Al2O3 curve. The solubility of oxygen in Fe-Al alloys is about 6.35 ppm with 0.4 wt.% aluminum at 1873 K. Liquid FeO-Al2O3, hercynite (FeAl2O4), and alumina (Al2O3) are three possible products during the deoxidation process. Based on thermodynamic calculation, the value of the interaction coefficient of eoAl was determined as -0.75 at 1873 K. This value is in good agreement with experimental curves in the literature.

  12. Enhanced Light Extraction in AlInGaN UV Light-Emitting Diodes by an Embedded AlN/AlGaN Distributed Bragg Reflector

    International Nuclear Information System (INIS)

    A novel kind of AlInGaN ultraviolet (UV) light-emitting diode (LED) with an embedded AlN/Al0.3Ga0.7N distributed Bragg reflector (DBR) is proposed to enhance light extraction efficiency (LEE). The simulation technique we adopt to calculate the LEE of LEDs is based on the theory of spontaneous emission in a layered medium, the well-known mode-matching technique and the scattering matrix approach. The AlN/Al0.3Ga0.7N DBR was intentionally designed to have peak reflectivity at the LED emission wavelength and the optical properties of the DBR were simulated by using the transfer matrix method. A high LEE of 45.7% at 370 nm wavelength was predicted for a proposed AlInGaN UV LED consisting of 24 periods of the AlN/Al0.3Ga0.7N DBR, which is 1.5 times of that of the conventional AlInGaN UV LED. The investigation shows that the AlN/Al0.3Ga0.7N DBR grown on GaN templates with sapphire as a substrate by MOCVD can enhance the LEE effectively and would be very promising for the fabrication of high performance GaN-based UV LEDs

  13. Spatial and temporal mapping of Al and AlO during oxidation in pulsed laser ablation of LaAlO3

    International Nuclear Information System (INIS)

    We present the first spatio-temporal mapping of two simultaneously present species in a plasma used for pulsed laser deposition. We apply laser induced fluorescence spectroscopy (LIF) to map ground state populations of Al and AlO in plasma plumes generated by ablation of LaAlO3 in an O2 or Ar atmosphere. Around a specific distance from the target, we observe Al vanish simultaneously with the turnup of AlO. This can be assigned to the oxidation of Al in the background atmosphere occurring after a sufficient slowing of the expanding Al front. This is consistent with the absence of such effects when argon is taken as background. A quantitative evaluation of data promises to reveal important dynamical reaction and deposition parameters for identification of the origin of specific properties of PLD grown films such as 2-dimensional conductive interfaces

  14. Effects of AlN and AlGaN Interlayer on Properties of InAlN/GaN Heterostructures

    International Nuclear Information System (INIS)

    InAlN/GaN heterojunction structures are grown on two-inch c-face(0001) sapphire substrates by metalorganic chemical vapour deposition. AlN and AlGaN interlayers are intentionally inserted into the structure to improve the electrical properties. The lowest sheet resistance of 359?/sq and the highest room-temperature two-dimensional electron gas (2DEG) mobility of 1051 cm2 V?1s?1 is obtained in the structure with AlN thickness of 1.3 nm. The structure with AlN thickness of 2 nm exhibits the highest 2DEG concentration of 1.84 × 1013 cm?2. The sample with an AlGaN interlayer gives a smoother surface morphology compared to the one using an AlN interlayer, indicating potential applications of this technique in device fabrication. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  15. AlGaN nanocolumns and AlGaN/GaN/AlGaN nanostructures grown by molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Ristic, J.; Sanchez-Garcia, M.A.; Ulloa, J.M.; Calleja, E. [Departamento de Ingenieria Electronica, ETSI Telecomunicacion, Universidad Politecnica de Madrid, Ciudad Universitaria, 28040 Madrid (Spain); Sanchez-Paramo, J.; Calleja, J.M. [Departamento de Fisica de Materiales, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Jahn, U.; Trampert, A.; Ploog, K.H. [Paul-Drude-Institut fuer Festkoerperelektronik, Hausvogteiplatz 5-7, 10117 Berlin (Germany)

    2002-12-01

    This work reports on the characterization of hexagonal, single crystal AlGaN nanocolumns with diameters in the range of 30 to 100 nm grown by molecular beam epitaxy on Si(111) substrates. The change of the flux ratio between the Al and the total III-element controls the alloy composition. The Al composition trend versus the Al flux is consistent both with the E{sub 2} phonon energy values measured by inelastic light scattering and the luminescence emission peaks position. High quality low dimensional AlGaN/GaN/AlGaN heterostructures with five GaN quantum discs, 2 and 4 nm thick, embedded into the AlGaN columns, were designed in order to study the quantum confinement effects. (Abstract Copyright [2002], Wiley Periodicals, Inc.)

  16. Liquidus temperatures of Na3AlF6-AlF3-CaF2-KF-LiF-Al2O3 melts

    OpenAIRE

    Peng J.P.; Di Y.Z.; Wang Y.W.; Bai Y.B.; Feng N.X.

    2014-01-01

    Temperatures for the primary crystallization of Na3AlF6-AlF3-CaF2-KF-LiF-Al2O3 system adopted in aluminum electrolysis process were determined by thermal analysis. An empirical equation was derived to describe the liquidus temperatures for the primary crystallization of this multicomponent electrolyte system: t/?=1011 + 0.7w(AlF3) - 0.232w(AlF3)2 - 7.65w(Al2O3) + 0.523w(Al2O3)2 - 8.96w(LiF) + 0.043w(LiF)2 - 3.32w(KF) - 0.12w(KF)2 - 3.28w(CaF2) +0.037w(CaF2)2 + 0....

  17. Investigation of thermal conductivity and microstructure of the ?-Al2O3 particulate reinforced aluminum composites (Al/Al2O3-MMC) by powder metallurgy method

    International Nuclear Information System (INIS)

    The thermal conductivity of the ?-Al2O3 particulate reinforced aluminum composites (Al/Al2O3-MMC) prepared by powder metallurgy method have been investigated. The thermal conductivity shows linear dependence on temperature in the investigated range. The increase in the thermal conductivity of the composites with decreasing Al2O3 particles size could be due to greater stability of the thermal conductive paths for smaller Al2O3 particles. In addition, when composites are heated, the heat will tend to flow through the Al particles and electric charge flows where resistance is lowest. It is seen that the thermal conductivity decrease with increasing Al2O3 volume fraction.

  18. Effects of Al content on structure and mechanical properties of hot-rolled ZrTiAlV alloys

    International Nuclear Information System (INIS)

    Highlights: • Phase structure is greatly dependent on the Al content. • Intermetallic compound will precipitates while Al content is over 6.9 wt%. • Equiaxed ?-phase grains present in the hot-rolled alloy with 6.9 wt% Al. • Alloys with Al content from 3.3 wt% to 5.6 wt% have good mechanical properties. - Abstract: Zirconium alloys show attractive properties for astronautic applications where the most important factors are anti-irradiation, corrosion resistance, anti-oxidant, very good strength-to-weight ratio. The effects of Al content (2.2–6.9 wt%) on structure and mechanical properties of the hot-rolled ZrTiAlV alloy samples were investigated in this study. Each sample of the hot-rolled ZrTiAlV alloys with Al contents from 2.2 wt% to 5.6 wt% is composed of the ? phase and ? phase, meanwhile, the relative content of the ? phase increased with the Al content. However, the (ZrTi)3Al intermetallic compound was observed as the Al content increased to 6.9 wt%. Changes of phase compositions and structure with Al content distinctly affected mechanical properties of ZrTiAlV alloys. Yield strength of the alloy with 2.2 wt% Al is below 200 MPa. As Al content increased to 5.6 wt%, the yield strength, tensile strength and elongation of the examined alloy are 1088 MPa, 1256 MPa and 8%, respectively. As Al content further increased to 6.9 wt%, a rapid decrease in ductility was observed as soon as the (ZrTi)3Al intermetallic compound precipitated. Results show that the ZrTiAlV alloys with Al contents between 3.3 wt% and 5.6 wt% have excellent mechanical properties

  19. The experimental investigation of phase equilibria in the Al-rich corner within the ternary Al–Mn–Be system

    International Nuclear Information System (INIS)

    Highlights: •We investigated the constitution of the Al-rich corner of the Al–Mn–Be system. •Be4AlMn is a thermodynamically stable phase in the Al-corner of the Al–Mn–Be system. •The T-phase (Al15Mn3Be2) is not a stable phase in the Al-corner at 600 °C. •The ?-Al4Mn phase is a stable phase in the Al-corner at 600 °C. •T-phase is a stable phase at 750 °C. -- Abstract: This work investigated the constitution of the Al-rich corner within the ternary Al–Mn–Be phase diagram using SEM + EDS, AES, XRD and DSC. With respect to the results, an isothermal cross-section at 600 °C was established, as well as a prediction of the apparent liquidus projection in the Al-corner. Be4AlMn is a thermodynamically stable phase in the Al-rich corner of the ternary phase diagram. The other ternary T-phase, usually designated as Al15Mn3Be2, formed during solidification in alloys with Be:Mn atomic ratios of less than 4:1, and having more than 1.5 at.% Mn. This phase is not a stable phase in the Al-rich corner at 600 °C. In contrast, the ?-Al4Mn phase is a stable one. The T-phase is stable over a rather large part of the phase diagram at least within a temperature range close to 750 °C, where it is in equilibrium with the Al-rich liquid phase, and Be4AlMn

  20. Chemical etching of AlN and InAlN in KOH solutions

    Energy Technology Data Exchange (ETDEWEB)

    Vartuli, C.B.; Lee, J.W.; MacKenzie, J.D.; Pearton, S.J.; Abernathy, C.R. [Univ. of Florida, Gainesville, FL (United States); Zolper, J.C.; Shul, R.J. [Sandia National Labs., Albuquerque, NM (United States); Ren, F. [Lucent Technologies, Murray Hill, NJ (United States). Bell Labs.

    1997-12-31

    Wet chemical etching of AlN and In{sub x}Al{sub 1{minus}x}N was investigated in KOH-based solutions as a function of etch temperature, and material quality. The etch rates for both materials increased with increasing etch temperatures, which was varied from 20 C to 80 C. The crystal quality of AlN prepared by reactive sputtering was improved by rapid thermal annealing at temperatures to 1,100 C with a decreased wet etch rate of the material measured with increasing anneal temperature. The etch rate decreased approximately an order of magnitude at 80 C etch temperature after a 1,100 C anneal. The etch rate for In{sub 0.19}Al{sub 0.82}N grown by Metal Organic Molecular Beam Epitaxy was approximately three times higher for material on Si than on GaAs. This corresponds to the superior crystalline quality of the material grown on GaAs. Etching of In{sub x}Al{sub 1{minus}x}N was also examined as a function of In composition. The etch rate initially increased as the In composition changed from 0 to 36%, and then decreased to 0 {angstrom}/min for InN. The activation energy for these etches is very low, 2.0 {+-} 0.5 kcal{center_dot}mol{sup {minus}1} for the sputtered AlN. The activation energies for InAlN were dependent on In composition and were in the range 2--6 kcal{center_dot}mol{sup {minus}1}. GaN and InN layers did not show any etching in KOH at temperatures up to 80 C.

  1. Al-Ca and Al-Fe metal-metal composite strength, conductivity, and microstructure relationships

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyong June

    2011-12-01

    Deformation processed metal-metal composites (DMMC’s) are composites formed by mechanical working (i.e., rolling, swaging, or wire drawing) of two-phase, ductile metal mixtures. Since both the matrix and reinforcing phase are ductile metals, the composites can be heavily deformed to reduce the thickness and spacing of the two phases. Recent studies have shown that heavily drawn DMMCs can achieve anomalously high strength and outstanding combinations of strength and conductivity. In this study, Al-Fe wire composite with 0.07, 0.1, and 0.2 volume fractions of Fe filaments and Al-Ca wire composite with 0.03, 0.06, and 0.09 volume fractions of Ca filaments were produced in situ, and their mechanical properties were measured as a function of deformation true strain. The Al-Fe composites displayed limited deformation of the Fe phase even at high true strains, resulting in little strengthening effect in those composites. Al-9vol%Ca wire was deformed to a deformation true strain of 13.76. The resulting Ca second-phase filaments were deformed to thicknesses on the order of one micrometer. The ultimate tensile strength increased exponentially with increasing deformation true strain, reaching a value of 197 MPa at a true strain of 13.76. This value is 2.5 times higher than the value predicted by the rule of mixtures. A quantitative relationship between UTS and deformation true strain was determined. X-ray diffraction data on transformation of Al + Ca microstructures to Al + various Al-Ca intermetallic compounds were obtained at the Advanced Photon Source at Argonne National Laboratory. Electrical conductivity was measured over a range of true strains and post-deformation heat treatment schedules.

  2. Ma'ruf al-Rusafi : His Life and Works

    OpenAIRE

    Md. Joynul Haque

    2012-01-01

    The humanist Iraqi poet, Ma?ruf al-Rusafi born in al-Rusafa district of Baghdad in 1875 A.D, his early education was confined to the traditional Kuttab (Quranic School). He later joined „Al-Rushdiyya?Military School in Baghdad, but left after three years, having failed the course. Then he was fortunate in having al-Shaikh Mahmud Shukri alAlusi, an authority in Arabic, as his guide for twelve years, who introducrd him to Islamic Priciples, Sciences, Sufism and Linguistics.Al-Rusafi began...

  3. Synthesis, crystal structures, and hydrogen-storage properties of Eu(AlH4)2 and Sr(AlH4)2 and of their decomposition intermediates, EuAlH5 and SrAlH5.

    Science.gov (United States)

    Pommerin, André; Wosylus, Aron; Felderhoff, Michael; Schüth, Ferdi; Weidenthaler, Claudia

    2012-04-01

    Complex Eu(AlH(4))(2) and Sr(AlH(4))(2) hydrides have been prepared by a mechanochemical metathesis reaction from NaAlH(4) and europium or strontium chlorides. The crystal structures were solved from powder X-ray diffraction data in combination with solid-state (27)Al NMR spectroscopy. The thermolysis pathway was analyzed in detail, allowing identification of new intermediate EuAlH(5)/SrAlH(5) compounds. Rehydrogenation experiments indicate that the second decomposition step is reversible. PMID:22404046

  4. Ferromagnetic Cu-doped AlN nanorods

    International Nuclear Information System (INIS)

    Copper-doped AlN (AlN:Cu) nanorods were grown on catalyst-free Si substrates by chemical vapour deposition. The AlN:Cu nanorods exhibited the wurtzite structure with a growth direction along the c-axis. Ferromagnetic ordering of the AlN:Cu nanorods was observed at room temperature by an alternating gradient magnetometer. The spontaneous magnetization and the coercivity of the AlN:Cu nanorods are about 0.38 emu cm-3 and 100 Oe, respectively. The results reveal that Cu is a potential nonmagnetic dopant for AlN

  5. Microstructure and mechanical properties of Ti{sub 2}AlC-reinforced TiAl composites

    Energy Technology Data Exchange (ETDEWEB)

    Ai, Taotao; Yu, Qi; Feng, Xiaoming; Zhang, Yingtang; Li, Wenhu [Shaanxi University of Technology, Hanzhong (China). School of Materials Science and Engineering; Liu, Fang [Shaanxi University of Technology, Hanzhong (China). School of Management

    2014-11-15

    Ti{sub 2}AlC/TiAl composites were successfully in-situ synthesized by reaction hot pressing using Ti, Al, TiC and CNTs as starting materials. The results indicate that the as-sintered composites mainly consist of Ti{sub 2}AlC and TiAl phases. The mechanical properties of the 23 wt.% Ti{sub 2}AlC/TiAl composite exhibit the highest values, with a flexural strength and fracture toughness of 652.5 ± 76.8 MPa and 6.6 ± 0.5 MPa m{sup 1/2}, respectively. The complex structure coupled with dispersed Ti{sub 2}AlC micro-particulates is responsible for the enhancement in the strength. Toughening of the composite is mainly attributed to crack deflection, crack bridging, crack branching and pull-out of the Ti{sub 2}AlC particles, as well as transgranular cracking.

  6. Characterization of Al2O3 coatings oxidized from Al with different proportion of seed crystals at a lower temperature

    International Nuclear Information System (INIS)

    Al layer with ?-Al2O3 seed crystals was prepared on the surface of 316L stainless steel (SS) by a double cathodes discharge technique, in which the mixed targets of pure Al doped with different proportions of ?-Al2O3 were used. Then, Al2O3 coatings were obtained after plasma oxidization at 580 °C. The phase composition, microstructure and morphology of the coatings were studied respectively by means of glancing-angle (1°) X-ray diffractometry (GAXRD) and scanning electron microscopy (SEM). Furthermore, the bonding force and corrosion resistance of the coatings were measured. The results indicated that ?-Al2O3 nucleated and grew surrounding the seed crystals as the Volmer–Weber Mode. The Al2O3 coating was compact, performing a good corrosion resistance and metallurgical bonding. The inducing effects of ?-Al2O3 with different fractions were discussed. ?-Al2O3 (5.5 wt.%) was distributed in the Al layer when the target possessing 10% ?-Al2O3 was used. After plasma oxidation, 65.54 wt.% ?-Al2O3 was obtained which was 10.34% more than that obtained by the oxidation of pure Al at the same condition. However, the inducing effects became weak with the further increment of content of ?-Al2O3 seed crystals.

  7. Interdiffusion between U(Mo,Pt) or U(Mo,Zr) and Al or Al A356 alloy

    Science.gov (United States)

    Komar Varela, C.; Mirandou, M.; Aricó, S.; Balart, S.; Gribaudo, L.

    2009-12-01

    Solid state reactions in chemical diffusion couples U-7 wt.%Mo-0.9 wt.%Pt/Al at 580 °C and U-7 wt.%Mo-0.9 wt.%Pt/Al A356 alloy, U-7 wt.%Mo-1 wt.%Zr/Al and U-7 wt.%Mo-1 wt.%Zr/Al A356 alloy at 550 °C were characterized. Results were obtained from optical and scanning electron microscopy, electron probe microanalysis and X-ray diffraction. The UAl 3, UAl 4 and Al 20Mo 2U phases were identified in the interaction layers of ?U(Mo,Pt)/Al and ?U(Mo,Zr)/Al diffusion couples. Al 43Mo 4U 6 ternary compound was also identified in ?U(Mo,Zr)/Al due to the decomposition of ?U(Mo,Zr) phase. The U(Al,Si) 3 and U 3Si 5 phases were identified in the interaction layers of ?U(Mo,Pt)/Al A356 and ?U(Mo,Zr)/Al A356 diffusion couples. These phases are formed due to the migration of Si to the interaction layer. In the diffusion couple U(Mo,Zr)/Al A356, Zr 5Al 3 phase was also identified in the interaction layer. The use of synchrotron radiation at Brazilian Synchrotron Light Laboratory (LNLS, CNPq, Campinas, Brazil) was necessary to achieve a complete crystallographic characterization.

  8. Interdiffusion between U(Mo,Pt) or U(Mo,Zr) and Al or Al A356 alloy

    International Nuclear Information System (INIS)

    Solid state reactions in chemical diffusion couples U-7 wt.%Mo-0.9 wt.%Pt/Al at 580 deg. C and U-7 wt.%Mo-0.9 wt.%Pt/Al A356 alloy, U-7 wt.%Mo-1 wt.%Zr/Al and U-7 wt.%Mo-1 wt.%Zr/Al A356 alloy at 550 deg. C were characterized. Results were obtained from optical and scanning electron microscopy, electron probe microanalysis and X-ray diffraction. The UAl3, UAl4 and Al20Mo2U phases were identified in the interaction layers of ?U(Mo,Pt)/Al and ?U(Mo,Zr)/Al diffusion couples. Al43Mo4U6 ternary compound was also identified in ?U(Mo,Zr)/Al due to the decomposition of ?U(Mo,Zr) phase. The U(Al,Si)3 and U3Si5 phases were identified in the interaction layers of ?U(Mo,Pt)/Al A356 and ?U(Mo,Zr)/Al A356 diffusion couples. These phases are formed due to the migration of Si to the interaction layer. In the diffusion couple U(Mo,Zr)/Al A356, Zr5Al3 phase was also identified in the interaction layer. The use of synchrotron radiation at Brazilian Synchrotron Light Laboratory (LNLS, CNPq, Campinas, Brazil) was necessary to achieve a complete crystallographic characterization.

  9. Relationship between the growth rate and Al incorporation of AlGaN by metalorganic chemical vapor deposition

    International Nuclear Information System (INIS)

    Research highlights: The growth rate and its relationship with Al content of MOCVD-grown AlGaN alloy films are investigated. It is found that both parasitic reaction and competitive adsorption play important roles in determining the growth rate and Al incorporation in AlGaN. Low reactor pressure and a decrease of absolute amount of Ga atoms arriving on the substrate may lead to a higher Al content in AlGaN film. The research results are helpful to control the Al content of AlGaN during the materials growth. - Abstract: The growth rate and its relationship with growth conditions of AlGaN alloy films by metalorganic chemical vapor deposition (MOCVD) are investigated. It is found that both parasitic reaction and competitive adsorption play important roles in determining the growth rate and Al incorporation in AlGaN. Low reactor pressure can weaken parasitic reactions, thus increasing the Al composition. In addition, a decrease of absolute amount of Ga atoms arriving on the substrate may lead to a lower Ga competitive power, and then a higher Al content in AlGaN film.

  10. Fabrication of Al/Al3Ti Functionally Graded Materials by Reaction Centrifugal Mixed-Powder Method

    Science.gov (United States)

    El-Hadad, Shimaa; Sato, Hisashi; Miura-Fujiwara, Eri; Watanabe, Yoshimi

    2011-01-01

    Formation of compositional gradient in Al/Al3Ti Functionally graded materials (FGMs) fabricated by the centrifugal method (CM) depends mainly on the centrifugal force and the processing temperature. In this study, a novel centrifugal method, reaction centrifugal mixed-powder method (RCMPM), was proposed to fabricate Al/Al3Ti FGMs under fixed centrifugal force (G=80). The effects of RCMPM processing temperature on the formation of Al3Ti intermetallics, its morphology and its distribution in the fabricated Al/Al3Ti FGMs have been investigated. Fine granular Al3Ti were observed at relatively lower processing temperature while the known coarse platelet-like particles of Al3Ti could be achieved at higher casting temperatures. Moreover, Ti3Al intermetallics compound and unreacted Ti phases are also observed along with Al3Ti particles. In addition, distribution of Al3Ti intermetallics size and their volume fraction showed a significant change when the Al/Al3Ti FGMs processed at different temperatures relative to the liquidus temperature of the master alloy.

  11. Structural and mechanical characterization of Al-based composite reinforced with heat treated Al2O3 particles

    International Nuclear Information System (INIS)

    Highlights: • Al2O3 crystals added to the metal matrix of the liquid aluminum. • Heat treatment applied on the Al2O3 powders, changed the morphology of the powders. • Heat treatment of particles results in finer grins and subsequently more wettability. • Addition of heat treated alumina to A356 could increase the mechanical properties. - Abstract: In this study, the addition of 1.00 wt.% Al2O3 crystals to the metal matrix of the liquid aluminum was studied. In order to investigate the influence of heat treatment on activation of Al2O3 powders and mechanical properties of Al–Al2O3 composites, the Al2O3 particles were heated at 1000 °C. X-ray Diffraction (XRD) analysis used to characterize the crystal lattice of Al2O3 and its variation during heat treatment. The size and morphology of the Al2O3 grains was evaluated by Scanning Electron Microscopy (SEM). The results showed a considerable change in morphology of Al2O3 grains during the heat treatment. Mechanical evaluation such as hardness, compression and wear tests showed enhancement in the properties of Al–1.00 wt.% heat treated Al2O3 vs. Al–1.00 wt.% Al2O3 composite

  12. Hf dopants in ?'-Ni3Al alloy

    Science.gov (United States)

    Ivanovski, V. N.; Ceki?, B.; Umi?evi?, A.; Beloševi?-?avor, J.; Schumacher, G.; Koteski, V.; Barudzija, T.

    2013-08-01

    The Time Differential Perturbed Angular (TDPAC) measurements of nuclear quadrupole interactions (NQIs) at 181Ta ion probe in the polycrystalline intermetallic alloy ?'-Ni3Al doped with 0.2 at. % Hf were performed in the temperature range 78-1230 K, in order to determine the lattice location of Hf atoms in the ordered ?'-Ni3Al structure. The two NQIs obtained are discussed within the present L12 cubic structure and a tetragonal distortion of L12 to another two DO22 and L60 type structures. The first low frequency NQI at the site of the 181Ta ion-probe after substitution of aluminum for hafnium in DO22 at ambient temperature, is vQ1(300 K) = 39(1) MHz with ?1 = 0. The corresponding high frequency value on the second crystallographic site in L60, is vQ2(300 K) = 204(14) MHz with ?2 = 0.47(11). These two NQI's have different temperature behavior. The presence of both DO22 and L60 tetragonal distortions of the parent cubic L12 lattice, detected after adding 0.2 at. % Hf, are with modulations to the lattice constant (a) with a ratio (c/a), 2.04 and 0.87, respectively. Ab initio calculations of electronic and structural properties and hyperfine parameters at the 181Ta ion probe of the ?'-Ni3Al-0.2 at. % Hf alloy were performed using the full potential augmented plane wave plus local-orbital (APW+lo) method as implemented in the WIEN2k code. The accuracy of the calculations and comparison with the experimental results enabled us to identify the observed hyperfine interactions and to infer the EFG sign that cannot be measured in conventional TDPAC measurements.

  13. Altern als Widerstand Aging as Resistance

    Directory of Open Access Journals (Sweden)

    Roberta Maierhofer

    2005-07-01

    Full Text Available Gullettes kulturwissenschaftliche Untersuchung Aged by Culture ist wie bereits ihre zwei vorangehenden Werke, die sich mit Altern beschäftigen – Safe at Last in the Middle Years: The Invention of the Midlife Progress Novel (1988 und Declining to Decline. Cultural Combat and the Politics of the Middle (1997 –, von großem persönlichen Engagement und durch ein politisches Anliegen motiviert. Sowohl die Dringlichkeit als auch der Widerstand, den Gullette, die sich als „age critic“ definiert, als moralische und politische Notwendigkeit postuliert, werden in der Zweiteilung der Abhandlung angesprochen: „Cultural Urgencies“ und „Theorizing Age Resistantly“. Während Gullette den Begriff „aged by culture“ bereits in Declining to Decline einführt, stellt sie ihn nun in den Mittelpunkt ihrer Untersuchung. Das Buch ist einerseits einer gesellschaftspolitischen Analyse der USA gewidmet, andererseits wird eine Theorie des Widerstands gegenüber Altersdiskriminierung entwickelt.Gullette’s cultural studies based analysis Aged by Culture is marked by great personal engagement and motivated by political goals, as are her two previous texts that deal with aging: Safe at Last in the Middle Years: The Invention of the Midlife Progress Novel (1988 and Declining to Decline. Cultural Combat and the Politics of the Middle (1997. Both the urgency as well as the resistance that Gullette, who defines herself as an “age critic,” postulates as a moral and political necessity are addressed in the two parts of the text: “Cultural Urgencies” and “Theorizing Age Resistantly.” Whereas Gullette had already introduced the concept “aged by culture” in Declining to Decline, now she has placed it at the center of her examination. On the one hand, the book is devoted to a sociopolitical analysis of the USA; on the other hand, it develops a theory of resistance to age discrimination.

  14. ANÁLISIS DE LA CRÍTICA SOCIAL AL MARKETING

    Scientific Electronic Library Online (English)

    RAYMOND, PRADA DAZA.

    2002-09-01

    Full Text Available Cada vez un mayor número de analistas y críticos sociales asocian el marketing con el consumo exagerado, y afirman que las empresas a menudo planifican la obsolescencia de sus productos con el ánimo de que los compradores adquieran nuevas versiones que incorporan muy pocas mejoras funcionales. Pero, [...] además, aseveran que la publicidad agrega demasiados costos al precio de los productos y que la ganancia bruta de los fabricantes es exagerada. Las críticas se extienden al señalamiento de abusos en el poder político de algunos grupos de industrias y a la discriminación de distritos habitados por familias de bajos ingresos. Al compás de las respuestas de los mercadólogos, los consumidores se organizan y cobra relevancia el concepto de que el marketing debe ser socialmente responsable y que los compradores potenciales pueden educar sus deseos más superfluos y caprichosos. Abstract in english An ever increasing number of analysts and social critics associate marketing with conspicuous consumption, even to the point of claiming that firms often engage in the planned obsolescence of their products with a view to selling newer versions with few if any functional improvements. Furthermore, t [...] hey claim that advertising adds a stiff surcharge to such products and that manufacturer´s profits are excessive. Such critics also point to abuses of the political power wielded by certain industries, and even to discrimination agains residents of low-income areas. The revelations of market analysts and critics have led to the formation of consumer´s groups and to the belief that marketing must exercise social responsibility. Potential buyers are also urged to rein in their more superfluous and whimsical desires.

  15. Polvos de Al-Al3Ti obtenidos mediante aleado mecánico y tratamiento térmico

    Directory of Open Access Journals (Sweden)

    Gallardo, J. M.

    2005-12-01

    Full Text Available Mixed powders of aluminium and titanium (10 wt % have been mechanically alloyed in an Attritor mill. A metastable solution of titanium in an aluminium matrix is obtained. Changes produced on shape and particle size, structure and microstructure, have been studied when milling time varies between 2 and 10 h. The final processing is carried out for a milling time of 10 h, with approximately 9 wt % of titanium dissolved in the matrix. Finally, a heat treatment is carried out at different temperatures, up to a maximum of 625 °C, which produces the precipitation of different phases such as different structures of Al3Ti and Al4C3. The appearance of these second phases is characterized according to the selected heat treatment temperature.Polvos mezclados de aluminio y titanio (10 % en peso han sido aleados mecánicamente en un molino Attritor, obteniéndose una solución metaestable de titanio en la matriz de aluminio. Se han estudiado los cambios producidos en la forma y tamaño de las partículas, estructura y microestructura, al variar el tiempo de molienda entre 2 y 10 h. El procesado final se realiza para un tiempo de 10 h, habiéndose disuelto aproximadamente un 9 % en peso de titanio. Finalmente, se realiza un tratamiento térmico a diversas temperaturas, hasta un máximo de 625 °C, lo que produce la precipitación de diversas fases, como distintas estructuras de Al3Ti y Al4C3. La aparición de estas segundas fases es caracterizada en función de la temperatura de tratamiento utilizada.

  16. Properties of an AlGaN/AlN distributed-Bragg-reflector structure

    Science.gov (United States)

    Zhang, Li-Li; Liu, Zhan-Hui; Huang, Xiao-Gu; Li, Qing-Fang; Zhang, Rong; Xie, Zi-Li; Xiu, Xiang-Qian

    2014-10-01

    An AlGaN/AlN distributed-Bragg-reflector (DBR) structure with a high Al content was grown by using plasma-assisted molecular beam epitaxy (PA-MBE). The properties of the sample were characterized by using the transmission electron microscopy, high-resolution X-ray diffraction, atomic force microscopy, and reflectivity spectrum measurements. The reciprocal space mapping analysis indicated that the strain in the AlGaN layers was partially relaxed. The morphology of the DBR exhibited a surface covered by grains (average size of about 130 nm), and the surface roughness was about 2 nm. The spectral measurements showed that the DBR structure presented a peak reflectivity of 68.8% at the center wavelength of 247 nm, which indicated that this DBR structure could work in the deep solar-blind UV region with acceptable reflectivity. However, the optical properties of the DBR structure were deteriorated by the fluctuation of the Al composition, non-uniformity of the layer thickness, the blurry, rough interface in the DBR structure, and so on.

  17. Creep strength of centrifugally cast Al-rich TiAl alloys

    International Nuclear Information System (INIS)

    High-temperature creep of a binary Al60Ti40 (at.%) alloy in the as-cast state and after annealing at 1223 K for 200 h which produced nearly lamellar ?-TiAl + r-Al2Ti microstructure was studied utilizing creep compression tests in a temperature range between 1173 and 1323 K in air. The material was manufactured by centrifugal casting. Microstructural characterization was carried out employing light-optical scanning (SEM) and transmission electron microscopy (TEM) as well as X-ray diffraction (XRD) analyses. It is shown that the alloy exhibits reasonable creep resistance at 1173 K, especially in relation to its low density of around 3.8 g/cm3. Stress exponents calculated as n = ?log (strain rate)/?log (stress) = 4 were found to be relatively constant for the temperature and stress regime investigated. This indicates that dislocation climb may be the rate controlling creep mechanism. The assessment of creep tests conducted at identical stress levels and varying temperatures yielded activation energies for creep of around Q = 457 kJ/mol in the as-cast condition. This value is significantly higher than those found in literature for interdiffusion of Al or Ti in ?-TiAl. It is concluded that the difference is a due to the instability of the microstructure of the as-cast multi-phase alloy.

  18. Magnetic properties of PrPdAl and NdPdAl

    International Nuclear Information System (INIS)

    Magnetic phase transitions of the ternary intermetallic compounds PrPdAl and NdPdAl with hexagonal ZrNiAl type crystal structure were investigated by means of specific heat and neutron diffraction experiments. The triangular coordination symmetry of the magnetic rare-earth atoms on site 3f gives rise to geometrical frustration and leads to incommensurate antiferromagnetic structures. PrPdAl undergoes magnetic phase transitions at TN,1=4.2 K and TN,2?1.5 K. The magnetic structure at 1.5 K corresponds to a propagation vector k=[1/2, 0, ?], ?=0.398, and the ordered Pr(2) moments of 1.9 ?B are significantly reduced below the value 3.1 ?B for Pr(1) and Pr(3). NdPdAl shows magnetic phase transitions at TN,1=5 K and TN,2=4 K. The magnetic propagation vector shows a pronounced temperature dependence above TN,2 and locks in to k=[1/4, 0, ?], ?=0.444, below TN,2. (orig.)

  19. Compactibility of Al/Al2O3 Isotropic Composite with Variation of Holding Time Sintering.

    Directory of Open Access Journals (Sweden)

    Eddy S Siradj

    2008-11-01

    Full Text Available The requirement of component with structural ability, light weight and also strength is increasing base on Metal Matrix Composites (MMCs by aluminum as matrix (AMCs. A structural ability is connected to composites compactibility which is depend on quality of interfacial bounding. Powder metallurgy is one of method to produce composite with powder mixing, compacting and sintering. Volume fractions reinforced and sintering time can influence composites compactibility. Volume fractions reinforced variable can produce different reinforcement effect. Beside that, on sintering enables the formation of new phase during sintering time. In this research, Al/Al2O3 isotropic composites are made with aluminum as matrix and alumina (Al2O3 as reinforced. Volume fraction reinforced used 10%. 20%. 30% and 40%. Sintering temperature and compaction pressure are each 600oC and 15 kN. The tests that applied are compression and metallographic test. The result that obtained is optimum compactibility of Al/Al2O3 composite reached at holding time 2 hour. During sintering, new phase can occur that is aluminum oxides (alumina, with unstable properties. The best volume fraction reinforced and holding time sintering are 40% and 2 hours.

  20. Revisiting the Al/Al?O? interface: coherent interfaces and misfit accommodation.

    Science.gov (United States)

    Pilania, Ghanshyam; Thijsse, Barend J; Hoagland, Richard G; Lazi?, Ivan; Valone, Steven M; Liu, Xiang-Yang

    2014-01-01

    We study the coherent and semi-coherent Al/?-Al2O3 interfaces using molecular dynamics simulations with a mixed, metallic-ionic atomistic model. For the coherent interfaces, both Al-terminated and O-terminated nonstoichiometric interfaces have been studied and their relative stability has been established. To understand the misfit accommodation at the semi-coherent interface, a 1-dimensional (1D) misfit dislocation model and a 2-dimensional (2D) dislocation network model have been studied. For the latter case, our analysis reveals an interface dislocation structure with a network of three sets of parallel dislocations, each with pure-edge character, giving rise to a pattern of coherent and stacking-fault-like regions at the interface. Structural relaxation at elevated temperatures leads to a further change of the dislocation pattern, which can be understood in terms of a competition between the stacking fault energy and the dislocation interaction energy at the interface. Our results are expected to serve as an input for the subsequent dislocation dynamics models to understand and predict the macroscopic mechanical behavior of Al/?-Al2O3 composite heterostructures. PMID:24670940

  1. Revisiting the Al/Al2O3 Interface: Coherent Interfaces and Misfit Accommodation

    Science.gov (United States)

    Pilania, Ghanshyam; Thijsse, Barend J.; Hoagland, Richard G.; Lazi?, Ivan; Valone, Steven M.; Liu, Xiang-Yang

    2014-01-01

    We study the coherent and semi-coherent Al/?-Al2O3 interfaces using molecular dynamics simulations with a mixed, metallic-ionic atomistic model. For the coherent interfaces, both Al-terminated and O-terminated nonstoichiometric interfaces have been studied and their relative stability has been established. To understand the misfit accommodation at the semi-coherent interface, a 1-dimensional (1D) misfit dislocation model and a 2-dimensional (2D) dislocation network model have been studied. For the latter case, our analysis reveals an interface dislocation structure with a network of three sets of parallel dislocations, each with pure-edge character, giving rise to a pattern of coherent and stacking-fault-like regions at the interface. Structural relaxation at elevated temperatures leads to a further change of the dislocation pattern, which can be understood in terms of a competition between the stacking fault energy and the dislocation interaction energy at the interface. Our results are expected to serve as an input for the subsequent dislocation dynamics models to understand and predict the macroscopic mechanical behavior of Al/?-Al2O3 composite heterostructures. PMID:24670940

  2. Infrared spectra of aluminum hydrides in solid hydrogen: Al2H4 and Al2H6.

    Science.gov (United States)

    Wang, Xuefeng; Andrews, Lester; Tam, Simon; DeRose, Michelle E; Fajardo, Mario E

    2003-07-30

    The reaction of laser-ablated Al atoms and normal-H(2) during co-deposition at 3.5 K produces AlH, AlH(2), and AlH(3) based on infrared spectra and the results of isotopic substitution (D(2), H(2) + D(2) mixtures, HD). Four new bands are assigned to Al(2)H(4) from annealing, photochemistry, and agreement with frequencies calculated using density functional theory. Ultraviolet photolysis markedly increases the yield of AlH(3) and seven new absorptions for Al(2)H(6) in the infrared spectrum of the solid hydrogen sample. These frequencies include terminal Al-H(2) and bridge Al-H-Al stretching and AlH(2) bending modes, which are accurately predicted by quantum chemical calculations for dibridged Al(2)H(6), a molecule isostructural with diborane. Annealing these samples to remove the H(2) matrix decreases the sharp AlH(3) and Al(2)H(6) absorptions and forms broad 1720 +/- 20 and 720 +/- 20 cm(-1) bands, which are due to solid (AlH(3))(n). Complementary experiments with thermal Al atoms and para-H(2) at 2.4 K give similar spectra and most product frequencies within 2 cm(-1). Although many volatile binary boron hydride compounds are known, binary aluminum hydride chemistry is limited to the polymeric (AlH(3))( solid. Our experimental characterization of the dibridged Al(2)H(6) molecule provides an important link between the chemistries of boron and aluminum. PMID:15369378

  3. Ethik als transdisziplinärer Ansatz für Geschlechterforschung

    Directory of Open Access Journals (Sweden)

    Regina Harzer

    2007-07-01

    Full Text Available „Ethik“ hat Hochkonjunktur, theoretisch und praktisch. Tierethik, Medizin- und Bioethik, Rechtsethik und Neuroethik, um nur einige aktuelle Auseinandersetzungen mit rekonstruierten und modernisierten Moralphilosophien zu nennen. „Ethikräte“ schießen wie Pilze aus dem Boden: Im Bereich des Sports ebenso wie im Rahmen kulturell-religiöser Gegenwartsdiskurse. Von daher verwundert es nicht, dass auch die Kategorie „Geschlecht“ ethischen Überprüfungen unterzogen wird. Im vorliegenden Sammelband werden Grundanliegen der feministischen Ethik aber nicht nur anhand feministischer Einzelbeschreibungen untersucht, sondern in den Kontext von unterschiedlichen Disziplinanforderungen gestellt. Deshalb präsentiert sich das Buch auch als Gang durch die Wissenschaften selbst.

  4. Carta al presidente del Colegio Médico

    Directory of Open Access Journals (Sweden)

    Giulio Alfredo Maccacaro

    2014-01-01

    Full Text Available Este texto reproduce la carta escrita por Giulio Alfredo Maccacaro (1924-1977 al pre- sidente del Colegio Médico de Milán, publicada en 1972 en el libro La medicine del capitale de Jean-Claude Polack. Luego de más de 40 años, esta reedición en la sección Memoria e Historia tiene por objetivo recuperar la figura de Giulio Maccacaro, no como trayectoria individual, sino inscripto en un movimiento colectivo –junto a Giovanni Berlinguer, Franco Basaglia y tantos otros– que replanteó el papel de la medicina y logró conjugar la práctica científica con un fuerte compromiso social.

  5. para medir adicción al amor en adolescentes

    Directory of Open Access Journals (Sweden)

    Blanca Estela Retana Franco

    2005-01-01

    Full Text Available La llamada ?adicción al amor? no es privativa de cierto grupo de individuos, máxime en etapas de la vida en las que se inicia el proceso de atracción y cortejo. Dado lo anterior, resultó importante desarrollar un instrumento para medir dicha adicción en los adolescentes. El instrumento, con validez y confiabilidad robustas, comprendió 45 reactivos y se aplicó a 300 estudiantes de secundaria. Los resultados indican la presencia de diez factores: dependencia, necesidad apremiante, alivio, celos, fisiología, emociones negativas, no adicción, cuidado de la relación, obsesión y resistencia. Se discuten el concepto y su impacto en la salud de individuos y parejas.

  6. Del presidente tlatoani al presidente gerente

    Directory of Open Access Journals (Sweden)

    Asael Mercado Maldonado

    2009-01-01

    Full Text Available El concepto de presidente tlatoani se relaciona con las formas de poder existentes en el México prehispánico, pertinentes para investigar su origen y uso desde una perspectiva del ejercicio del poder. En este artículo analizamos el símbolo del tlatoani como detentador único del máximo poder político que ha tenido vigencia en México, cuando menos desde 1917 -El jefe máximo de la revolución constitucionalista-, caracterizando al presidencialismo mexicano durante todo el siglo XX. La forma del presidente gerente prácticamente comienza con Carlos Salinas de Gortari hasta la fecha.

  7. Homenaje al Dr. Fernando Merino Niño

    OpenAIRE

    Lisbeth Berrueta; Siham Salmen

    2013-01-01

    encuentra tu pasión y hazla posible, dale un propósito a tu vida por encima de todo; que la motivación por alcanzar tus metas sea siempre mayor que el temor al fracaso” Anónimo FERNANDO MERINO NINO (1946-2011) DEDICO SU VIDA A SU PASION MÁS GRANDE: LA INVESTIGACION. Nació en España y a los 7 años de edad se mudó con su familia a Caracas, Venezuela, en donde creció y se obtuvo su título de Médico Cirujano a los 22 años de edad, en las aulas de la ilus...

  8. Thermodynamic properties of Al-Ce melts

    International Nuclear Information System (INIS)

    Thermodynamic modeling of Al-Ce melts was performed at a total pressure p = 105 Pa in an argon atmosphere over the temperature and concentration ranges 1773-2373 K and 0 ? xCe ? 1, respectively, corresponding to the liquid-phase region of the phase diagram of the system. The concentration and temperature dependences of the thermodynamic characteristics of the melts and the contents of melt components and gas phase components over the melts were calculated, the temperatures, enthalpies, and entropies of the liquid-gas transition were determined, and the phase diagram of the liquid-liquid + gas-gas transition was obtained

  9. Recrystallization in Al-Mn-Cr Alloys

    Directory of Open Access Journals (Sweden)

    D. B. Goel

    1980-07-01

    Full Text Available The recrystallization behaviour of pure aluminium and three Al-1wt per cent Mn alloys containing 0.0,0.1 and o.5 per cent Cr as ternary additions has been studied at 90 per cent deformation and at 300 degree centigrade temperatures. It has been observed that Mn and Cr retard the softening process. The presence of 0.1 per cent Cr is useful in lowering the softening rates, whereas o.5 per cent Cr enhances the softening of the alloy. The results are discussed on the basis of the role of precipitate particles and dissolved solute atoms on recrystallization behaviour.

  10. Orbit stability of the ALS storage ring

    International Nuclear Information System (INIS)

    The Advanced Light Source (ALS) storage ring, a synchrotron light source of the third generation, is specified to maintain its electron orbit stable within one tenth of the rms beam size. In the absence of a dedicated orbit feed-back system, several orbit-distorting effects were investigated, aided by a new interactive simulation tool, the code TRACY V. The effort has led to a better understanding of the behavior of a variety of accelerator subsystems and in consequence produced a substantial improvement in day-to-day orbit stability

  11. Ibn al-Haytham and geometry

    CERN Document Server

    Rashed, Roshdi

    2013-01-01

    Theory of Conics, Geometrical Constructions and Practical Geometry: A History of Arabic Sciences and Mathematics Volume 3, provides a unique primary source on the history and philosophy of mathematics and science from the mediaeval Arab world. The present text is complemented by two preceding volumes of A History of Arabic Sciences and Mathematics, which focused on founding figures and commentators in the ninth and tenth centuries, and the historical and epistemological development of 'infinitesimal mathematics' as it became clearly articulated in the oeuvre of Ibn al-Haytham.

  12. en torno al ciclo del agua

    Directory of Open Access Journals (Sweden)

    Mar\\u00EDa Rosa Miracle Sol\\u00E9

    2006-01-01

    Full Text Available La sostenibilidad ambiental está relacionada directamente con el ciclo del agua y las intervenciones del hombre sobre el mismo, tanto en su extracción, uso y eliminación. La conservación del suelo y la vegetación dependen invariablemente del impacto acumulado de este proceso. La perspectiva de un cambio climático mayor, con el subsecuente aumento de las temperaturas en el planeta, implica transformaciones radicales en el ciclo del agua, y por ende, en su disponibilidad y utilización. Para ello se hace imperioso mejorar radicalmente el ahorro del agua, aumentando al mismo tiempo los sistemas de depuración y eficiencia en el regadío. La autora propone una seria de medidas en esta dirección.

  13. U-Mo/Al-Si interaction: Influence of Si concentration

    International Nuclear Information System (INIS)

    Within the framework of the development of low enriched nuclear fuels for research reactors, U-Mo/Al is the most promising option that has however to be optimised. Indeed at the U-Mo/Al interfaces between U-Mo particles and the Al matrix, an interaction layer grows under irradiation inducing an unacceptable fuel swelling. Adding silicon in limited content into the Al matrix has clearly improved the in-pile fuel behaviour. This breakthrough is attributed to an U-Mo/Al-Si protective layer around U-Mo particles appeared during fuel manufacturing. In this work, the evolution of the microstructure and composition of this protective layer with increasing Si concentrations in the Al matrix has been investigated. Conclusions are based on the characterization at the micrometer scale (X-ray diffraction and energy dispersive spectroscopy) of U-Mo7/Al-Si diffusion couples obtained by thermal annealing at 450 deg. C. Two types of interaction layers have been evidenced depending on the Si content in the Al-Si alloy: the threshold value is found at about 5 wt.% but obviously evolves with temperature. It has been shown that for Si concentrations ranging from 2 to 10 wt.%, the U-Mo7/Al-Si interaction is bi-layered and the Si-rich part is located close to the Al-Si for low Si concentrations (below 5 wt.%) and close to the U-Mo for higher Si concentrations. For Si weight fraction in the Al alloy lower than 5 wt.%, the Si-rich sub-layer (close to Al-Si) consists of U(Al, Si)3 Al-Si) consists of U(Al, Si)3 + UMo2Al20, when the other sub-layer (close to U-Mo) is silicon free and made of UAl3 and U6Mo4Al43. For Si weight concentrations above 5 wt.%, the Si-rich part becomes U3(Si, Al)5 + U(Al, Si)3 (close to U-Mo) and the other sub-layer (close to Al-Si) consists of U(Al, Si)3 + UMo2Al20. On the basis of these results and of a literature survey, a scheme is proposed to explain the formation of different types of ILs between U-Mo and Al-Si alloys (i.e. different protective layers).

  14. Micro-structural evaluation of Ti/Al/Ni/Au ohmic contacts with different Ti/Al thicknesses in AlGaN/GaN HEMTs

    Energy Technology Data Exchange (ETDEWEB)

    Mahajan, Somna S., E-mail: somnamahajan@gmail.com; Dhaul, Anuradha; Laishram, Robert; Kapoor, Sonalee; Vinayak, Seema; Sehgal, B.K.

    2014-04-01

    Highlights: • Ohmic contacts with four different Ti/Al metal thickness ratios were fabricated on undoped Al{sub .28}Ga{sub .72}N/GaN HEMT under various annealing cycles using Rapid thermal processor. • Ohmic contact with Ti/Al metal thickness ratio, 1/5 showed superior quality in terms of R{sub c} and surface morphology. • Ni–Al alloy segregation on the surface as analyzed by EDAX seems to be related to bumpy surface morphology. • Ohmic contact with Ti/Al metal ratio 1/5 showed the presence of TiN by X-ray diffraction analysis. This was further confirmed by SIMS analysis. • The lower level of elemental Ti and Al at the surface of the contact with Ti/Al metal thickness ratio 1/5 compared to the other contacts indicated lower oxidation possibility and therefore superior quality ohmic contacts with the metal ratio 1/5. - Abstract: In this work, ohmic contacts were formed by varying the Ti/Al thickness ratio in the metal stack of Ti/Al/Ni/Au on Al{sub .28}Ga{sub .72}N/GaN HEMT epistructure followed by annealing in the temperature range 740–860 °C by rapid thermal processor (RTP). The contacts were electrically characterized for contact resistance (R{sub c}) and the sheet resistance (R{sub s}) of AlGaN/GaN epistructure. The ohmic contacts formed by Ti/Al metal thickness ratio of 1/5 exhibited lowest R{sub c} values and better surface morphology compared to the contacts formed by other Ti/Al metal thickness ratios. The difference observed in the electrical characterization of these contacts was correlated with their X-ray diffraction (XRD) and secondary ion mass spectroscopy (SIMS) analyses. The surface morphology of the ohmic metal post annealing showed two distinct regions in scanning electron microscope (SEM) images. The energy dispersive X-ray analysis (EDAX) identified these regions as Ni–Al and Au–Al rich. Ni–Al rich region is believed to be responsible for rough morphology. Further, the contact formed with Ti/Al metal thickness ratio 1/5 showed less number of elemental Al and Ti atoms and therefore was correlated with lower oxidation probability of the contact compared to ohmic contact formed by other metal thickness ratios.

  15. Micro-structural evaluation of Ti/Al/Ni/Au ohmic contacts with different Ti/Al thicknesses in AlGaN/GaN HEMTs

    International Nuclear Information System (INIS)

    Highlights: • Ohmic contacts with four different Ti/Al metal thickness ratios were fabricated on undoped Al.28Ga.72N/GaN HEMT under various annealing cycles using Rapid thermal processor. • Ohmic contact with Ti/Al metal thickness ratio, 1/5 showed superior quality in terms of Rc and surface morphology. • Ni–Al alloy segregation on the surface as analyzed by EDAX seems to be related to bumpy surface morphology. • Ohmic contact with Ti/Al metal ratio 1/5 showed the presence of TiN by X-ray diffraction analysis. This was further confirmed by SIMS analysis. • The lower level of elemental Ti and Al at the surface of the contact with Ti/Al metal thickness ratio 1/5 compared to the other contacts indicated lower oxidation possibility and therefore superior quality ohmic contacts with the metal ratio 1/5. - Abstract: In this work, ohmic contacts were formed by varying the Ti/Al thickness ratio in the metal stack of Ti/Al/Ni/Au on Al.28Ga.72N/GaN HEMT epistructure followed by annealing in the temperature range 740–860 °C by rapid thermal processor (RTP). The contacts were electrically characterized for contact resistance (Rc) and the sheet resistance (Rs) of AlGaN/GaN epistructure. The ohmic contacts formed by Ti/Al metal thickness ratio of 1/5 exhibited lowest Rc values and better surface morphology compared to the contacts formed by other Ti/Al metal thickness ratios. The difference observed in the electrical characterization of these contacts was correlated with their X-ray diffraction (XRD) and secondary ion mass spectroscopy (SIMS) analyses. The surface morphology of the ohmic metal post annealing showed two distinct regions in scanning electron microscope (SEM) images. The energy dispersive X-ray analysis (EDAX) identified these regions as Ni–Al and Au–Al rich. Ni–Al rich region is believed to be responsible for rough morphology. Further, the contact formed with Ti/Al metal thickness ratio 1/5 showed less number of elemental Al and Ti atoms and therefore was correlated with lower oxidation probability of the contact compared to ohmic contact formed by other metal thickness ratios

  16. Growth and characterization of TiAlN/CrAlN superlattices prepared by reactive direct current magnetron sputtering

    International Nuclear Information System (INIS)

    TiAlN and CrAlN coatings were prepared using a reactive direct current magnetron sputtering system from TiAl and CrAl targets. Structural characterization of the coatings using x-ray diffraction (XRD) revealed the B1 NaCl structure of TiAlN and CrAlN coatings with a prominent reflection along the (111) plane. The XPS data confirmed the bonding structures of TiAlN and CrAlN single layer coatings. Subsequently, nanolayered multilayer coatings of TiAlN/CrAlN were deposited on silicon and mild steel (MS) substrates at different modulation wavelengths (?) with a total thickness of approximately 1.0 ?m. The modulation wavelengths were calculated from the x-ray reflectivity data using modified Bragg's law. TiAlN/CrAlN multilayer coatings were textured along (111) for ?<200 A and the XRD patterns showed the formation of superlattice structure for coatings deposited at ?=102 A. The x-ray reflectivity data showed reflections of fifth and seventh orders for multilayer coatings deposited at ?=102 and 138 A, respectively, indicating the formation of sharp interfaces between TiAlN and CrAlN layers. The cross-sectional scanning electron microscopy image of TiAlN/CrAlN multilayer coatings indicated a noncolumnar and dense microstructure. A maximum hardness of 39 GPa was observed for TiAlN/CrAlN multilayer coatings deposited at ?=93 A, which was higher than the rule-of-mixture value (30 GPa) for TiAlN and CrAlN. Study of thermal stability of the coatings in air using micro-Ramanhe coatings in air using micro-Raman spectroscopy indicated that the TiAlN/CrAlN multilayer coatings were stable up to 900 deg. C in air. TiAlN/CrAlN multilayer coatings also exhibited improved corrosion resistance when compared to the MS substrate

  17. Comparison of CrAlN layers obtained with one (CrAl) or two targets (Cr and Al) by magnetron sputtering

    International Nuclear Information System (INIS)

    The aim of this study is to compare the properties of CrAlN coatings obtained by magnetron sputtering with one (CrAl) or two targets (Cr and Al). The influence of parameters such as the target bias voltage, the working pressure, the deposition time and the bias voltage applied on the Cr or Al targets on the properties of the layers was studied. We characterized the films by X-ray Diffraction, Scanning Electron Microscopy, coupled with Energy Dispersive Spectroscopy, nanoindentation and their residual stresses were also determined. The optimal films obtained with both methods are well crystallized, well-adherent to the substrate, and contained similar amounts of Al (20–30 at.%). The optimal coatings synthesized with one target presented properties not as good as those realized with two targets. Nevertheless, films made with one target showed a lower frictional coefficient probably due to composition control. The lack of compositional control with the use of one target limits the optimization process. With two targets, we have greater control over the film composition. This leads to higher hardness, lower stresses, and improved Young's modulus over films produced with a single CrAl target. Additionally, the morphologies are different (columnar with CrAl and dense with Cr and Al). To conclude, it seems more justified to work if possible with two independent targets. - Highlights: ? CrAlN layers obtained with a (Cr75Al25) target or Cr and Al independent targets. ? Lr Cr and Al independent targets. ? Lower friction coefficient and better crystallinity obtained with a sintered target. ? Al content of layers obtained with a sintered target limited and fixed. ? Better tribological properties of layers obtained with two targets. ? No economical, practical and scientific interest to work with a sintered target.

  18. Hydrogen Sensors Based on AlGaN/AlN/GaN Schottky Diodes

    International Nuclear Information System (INIS)

    Pt/AlGaN/AlN/GaN Schottky diodes are fabricated and characterized for hydrogen sensing. The Pt Schottky contact and the Ti/Al/Ni/Au ohmic contact are formed by evaporation. Both the forward and reverse currents of the device increase greatly when exposed to hydrogen gas. A shift of 0.3V at 300K is obtained at a fixed forward current after switching from N2 to 10%H2+N2. The sensor responses under different concentrations from 50ppm H2 to 10%H2+N2 at 373K are investigated. Time dependences of the device forward current at 0.5V forward bias in N2 and air atmosphere at 300 and 373K are compared. Oxygen in air accelerates the desorption of the hydrogen and the recovery of the sensor. Finally, the decrease of the Schottky barrier height and sensitivity of the sensor are calculated

  19. Resumen del libro: El transporte como soporte al desarrollo de Colombia. Una visión al 2040

    Directory of Open Access Journals (Sweden)

    Jorge Acevedo

    2009-05-01

    Full Text Available El propósito fundamental de este texto es que los lectores interesados tengan una visión global del libro "El transporte como soporte al desarrollo de Colombia. Una visión al 2040", trabajo interdisciplinario realizado por un grupo de profesores de la Universidad de los Andes y publicado por la misma Universidad. A continuación se resume en forma condensada algunos de los planteamientos y resultados de este libro, cuyo propósito fundamental no es predecir el futuro en tan largo plazo, sino plantear una visión prospectiva que estimule el debate sobre importantes decisiones de política pública que el país debe tomar en el corto plazo y que repercutirán decididamente en el largo plazo. Los méritos del trabajo pertenecen al grupo de autores, pero las omisiones e interpretaciones de este resumen son exclusiva responsabilidad de su autor.

  20. Characteristics of high Al content AlGaN grown by pulsed atomic layer epitaxy

    International Nuclear Information System (INIS)

    Al0.91Ga0.09N epilayers have been obtained by pulsed atomic layer epitaxy (PALE) technique on sapphire (0 0 0 1) substrates. Deep ultraviolet (DUV) photoluminescence (PL) spectroscopy and Raman scattering spectrum have been employed to study the optical transitions in Al0.91Ga0.09N epilayers. We found the exciton-phonon interaction by fitting the asymmetric PL peak, in which the transverse optical phonon (TO) and the longitudinal optical (LO) phonon are the main contributor. The abnormal S-shaped temperature dependence of the PL band peak is less pronounced or has disappeared. Further analysis shows that there possibly exists a high density of deeper localized state (?90 meV) in Al0.91Ga0.09N. The formation of these localized states provides a favorable condition for efficient light emission.

  1. AlGaN/AlN distributed Bragg reflectors for deep ultraviolet wavelengths

    Energy Technology Data Exchange (ETDEWEB)

    Moe, Craig G.; Wu, Yuan; Speck, James S. [Materials Department, College of Engineering, University of California, Santa Barbara, CA 93106 (United States); Piprek, Joachim; Keller, Stacia [Electrical and Computer Engineering Department, College of Engineering, University of California, Santa Barbara, CA 93106 (United States); DenBaars, Steven P. [Materials Department, College of Engineering, University of California, Santa Barbara, CA 93106 (United States); Electrical and Computer Engineering Department, College of Engineering, University of California, Santa Barbara, CA 93106 (United States); Emerson, David [Cree, Inc. 4600 Silicon Dr, Durham, NC 27703 (United States)

    2006-06-15

    Distributed Bragg reflectors with up to 21 periods consisting of AlN and Al{sub 0.58}Ga{sub 0.42}N layers were grown by metalorganic chemical vapor deposition. A periodic structure and good interface quality was verified by both transmission electron microscopy and X-ray diffraction, and was shown to be dependent on the composition of the underlying AlGaN base layer. Reflectivities of 49.8% at 285 nm and 66.6% at 245 nm were obtained with ten period superlattices. A reflectivity of 82.8% at 278 nm was measured for a twenty period structure. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

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

    International Nuclear Information System (INIS)

    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 AlxGa1?xAs/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.

  3. Al-Jazeera... varsti BBC asemel / Merle Krigul

    Index Scriptorium Estoniae

    Krigul, Merle

    2005-01-01

    Ülemaailmne televisiooni-impeerium, mille üks osa on ka uudistekanal Al-Jazeera, kavatseb laieneda. Tulemas on uus Al-Jazeera lastekanal ja spordikanal, rahvusvaheline inglisekeelse uudistekanal. Lisa: BBC püüab araabiakeelset turgu

  4. Alimentación al pecho y uso de la leche humana

    Directory of Open Access Journals (Sweden)

    2000-01-01

    Full Text Available Este documento sobre política de alimentación al pecho reemplaza al documento previo de la Academia Americana de Pediatría, reflejando los considerables avances que han ocurrido en los años recientes en el conocimiento científico sobre los beneficios de la alimentación al pecho, en los mecanismos subyacentes a estos beneficios y en la práctica de la alimentación al pecho. Este documento resume los beneficios de la alimentación al pecho para el niño, la madre y la nación, y plantea a partir del mismo principios para guiar al pediatra y otros proveedores de cuidados de salud, en la iniciación y mantenimiento de la alimentación al pecho. Este documento también delinea los diferentes modos en los cuales el pediatra puede promover, proteger, y apoyar la alimentación al pecho, no solo en su práctica individual sino también en el hospital, la facultad, la comunidad y la nación.

  5. Microstructure and properties of Mg-Al binary alloys

    Directory of Open Access Journals (Sweden)

    ZHENG Wei-chao

    2006-11-01

    Full Text Available The effects of different amounts of added Al, ranging from 1 % to 9 %, on the microstructure and properties of Mg-Al binary alloys were investigated. The results showed that when the amount of added Al is less than 5%, the grain size of the Mg-Al binary alloys decreases dramatically from 3 097 ?m to 151 ?m with increasing addition of Al. Further addition of Al up to 9% makes the grain size decrease slowly to 111 ?m. The ?-Mg dendrite arms are also refined. Increasing the amount of added Al decreases the hot cracking susceptibility of the Mg-Al binary alloys remarkably, and enhances the micro-hardness of the ?-Mg matrix.

  6. Suurajatolla Ali al-Sistani saabus Najaffi / Kalev Vilgats

    Index Scriptorium Estoniae

    Vilgats, Kalev

    2004-01-01

    Mässulise shiiidivaimuliku Moqtada al-Sadri Mahdi armee võitlejad on pidanud Najafis USA vägedega lahinguid juba kolm nädalat. Iraagi kõrgeim shiiiavaimulik suurajatolla Ali al-Sistani kutsub kõiki iraaklasi endaga Najaffi marssima, et lahingutele lõpp teha

  7. Irradiation behaviour of UAl3-Al and UAl2-Al dispersion fuel plates

    International Nuclear Information System (INIS)

    UAl3-Al and UAl2-Al dispersion fuel plates were prepared and irradiated in a pressurized water loop of the FR 2 (Karlsruhe). The irradiation tests were to give information on the chemical reaction of the UAlsub(x) particles with the Al matrix and on the swelling of the fuel plates by fission products, particularly by fission gas. After irradiation, the fuel plates did not show cladding failures by blister or crack formation in any case, which could be attributed to the irradiation behaviour of the fuel. To examine the overheating behaviour of irradiated fuel plates, annealing tests ('blister tests') were made at 200, 300, 400 and 5000C. The irradiation-induced reaction of the fuel particles with the Al matrix was followed by quantitative evaluation of microstructure components in micrographs of the fuel section. That evaluation was supported by some microprobe analyses and by microhardness measurements. The results show that Al-base dispersion fuels containing UAl3 or UAl2 are likewise suited for high burnups in research reactors. A uranium burnup of 40% is permissible in any case, independent of irradiation temperature at least up to 1800C. Above a burnup of 30 to 40%, fission product precipitation processes will strongly influence the behaviour of the dispersion fuel. The reaction of UAl3 and UAl2 fuel particles with the Al matrix results in the formation of a non-stoichiometric UAl4 phase, whose composition is about UAl5. However, that does not increase the volume percentage of the particles at high burnup. (orig./GSCH)

  8. DEGRADACIÓN FOTOCATALÍTICA DE FENOL EMPLEANDO ARCILLAS PILARIZADAS CON Al-Fe y Al-Cu

    Scientific Electronic Library Online (English)

    Jury, Ñungo-Moreno; J. G., Carriazo; S., Moreno; R. A., Molina.

    2011-09-01

    Full Text Available En el presente trabajo se muestra la pilarización de una arcilla colombiana tipo bentonita con los sistemas Al-Fe y Al-Cu, y la evaluación de su actividad fotocatalítica en la eliminación de fenol en medio acuoso diluido. Los sólidos obtenidos se caracterizaron por difracción de rayos X (DRX) y capa [...] cidad de intercambio catiónico (CIC), mostrando la efectiva modificación vía pilarización. La evaluación de la actividad catalítica de los sólidos revela el potencial de aplicación de éstos en la degradación de compuestos orgánicos contaminantes en medio acuoso mediante procesos fotoasistidos con radiación UV. Los resultados evidencian una mayor actividad fotocatalítica para la arcilla modificada con hierro y una mayor selectividad de la arcilla modificada con cobre hacia la formación de CO2 y H2O. Abstract in english In this work the pillaring of a Colombian natural clay (bentonite) with the Al-Fe and Al-Cu systems, and the assessment of their photocatalytic activity in the phenol elimination in aqueous solution are shown. The obtained solids were characterized by X-ray diffraction analyses and cationic exchange [...] capacity, showing the effective modification via pillaring. The catalytic activity assessment of the solids confirms the potential application of these catalysts on the organic pollutants degradation in aqueous medium by means of catalytic processes photo-assisted with UV radiation. The results show a higher photocatalytic activity for the Al-Fe-pillared clay and a higher selectivity for the Al-Cu-pillared clay towards the formation of CO2 and H2O.

  9. Mul??a?ah ‘Ammah ‘an al-Kutub al-?afr? f? al-Ma‘?hid al-D?n?yah

    Directory of Open Access Journals (Sweden)

    Affandi Mochtar

    2014-03-01

    Full Text Available Islamic intellectual tradition in Indonesia, among others, enriched by literature dars (textbooks that classical Arabic is still maintained boarding school until today. Literature known as the Kitab Kuning (KK it marks an important phase that arises from contact archipelago-Middle East more intensive and institutionalized in the scientific world of Islam in Indonesia since the early 16th century until the late 18th century. Until now in the Islamic tradition, the books became major elements that distinguish it from the modern education system. He is transmitted from one generation to the next as if not to appreciate the development and changes in society. But the question; justified in boarding schools of Islamic scholarship so static? If not, why KK used as the main reference for generations? Is not Islam supposed al-Quran and al-Hadith which they referenced?Copyright (c 2014 by SDI. All right reserved.DOI: 10.15408/sdi.v3i2.809

  10. Berkeley Lab's ALS generates femtosecond synchrotron radiation

    CERN Document Server

    Robinson, A L

    2000-01-01

    A team at Berkeley's Advanced Light Source has shown how a laser time-slicing technique provides a path to experiments with ultrafast time resolution. A Lawrence Berkeley National Laboratory team has succeeded in generating 300 fs pulses of synchrotron radiation at the ALS synchrotron radiation machine. The team's members come from the Materials Sciences Division (MSD), the Center for Beam Physics in the Accelerator and Fusion Research Division and the Advanced Light Source (ALS). Although this proof-of principle experiment made use of visible light on a borrowed beamline, the laser "time-slicing" technique at the heart of the demonstration will soon be applied in a new bend magnet beamline that was designed specially for the production of femtosecond pulses of X-rays to study long-range and local order in condensed matter with ultrafast time resolution. An undulator beamline based on the same technique has been proposed that will dramatically increase the flux and brightness. The use of X-rays to study the c...

  11. Modeling extrusion of particulate Al matrix composites

    International Nuclear Information System (INIS)

    Mechanical forming, notably at high temperatures to minimize cracking and particle-matrix degradation, of particulate Al matrix composites prepared by liquid metal mixing is an effective, rapid and inexpensive means of final fabrication into components. A hot torsion project on alloys and composites of 6061, A356, 7075 and 2618 with 10 to 20% of Al2O3 or SiC determined hot strength and ductility, constitutive constants and microstructural evolution. The modeling of extrusion of the various particulate metal matrix composites was conducted by DEFORM finite element analysis to develop strain rate, stress and temperature distributions through the peak load and into steady state following development of the hot zone. The relative load-stroke curves for these materials were determined for several billet temperatures, extrusion ratios and ram speeds. The extrudability was estimated on the basis of load, ductility and microstructure developed. The last is estimated from the torsion substructure which is very heterogeneous exhibiting regions of (i) subgrains (less recovered than the bulk alloy), (ii) non-cellular dense clouds of dislocations, and (iii) small highly misoriented cells potentially dynamic recrystallization nuclei which did not grow. (author)

  12. Estrategia, Orientación al Mercado y Desempeño Organizacional

    Directory of Open Access Journals (Sweden)

    Carmen Berenice Ynzunza Cort\\u00E9s

    2013-01-01

    Full Text Available La pequeña industria desempeña una función crucial en la economía y el desarrollo de los países. De acuerdo con datos del Instituto Nacional de Estadística y Geografía [1], la PYME en México representa el 99.1% de la estructura empresarial. Sin embargo, el nivel de desarrollo alcanzado, producto de la globalización, ha sido bajo en comparación a otros países. Por ello, dentro de los objetivos de investigación planteados en este trabajo están el analizar el impacto que las fuerzas de mercado tienen sobre las estrategias competitivas prospectoras y analizadoras; y determinar el vínculo existente entre las capacidades de orientación al mercado, la estrategia competitiva y el desempeño organizacional, en 116 Pymes del sector industrial del Estado de Querétaro, mediante un modelo estructural con un muestreo de conveniencia no probabilístico. Los resultados indican que las fuerzas del mercado afectan las estrategias competitivas prospectoras y analizadoras y que éstas favorecen la creación de las capacidades necesarias para generar una ventaja competitiva como la orientación al mercado, encontrándose que ésta capacidad organizacional es un factor importante para el crecimiento y el desempeño organizacional.

  13. Kant à la Davidson: Maximen als Proeinstellungen

    Directory of Open Access Journals (Sweden)

    Oliver Petersen

    2009-10-01

    Full Text Available Was sind Maximen gemäß Kants Moralphilosophie? Diese Frage entsteht, da Kant zwar eine Explikation von ‚Maxime‘ als ‚subjektives Prinzip des Wollens‘ angibt, diese Explikation aber selbst wieder sehr dunkel bleibt und schwer verständlich ist. Zur Beantwortung dieser Frage werde ich in einem ersten Teil versuchen, plausible Kandidaten dafür zu ermitteln, was unter Maximen zu verstehen ist. Dabei wird sich zeigen, dass Kandidaten, die aus Davidsons Handlungstheorie stammen, sehr geeignete Kandidaten sind. In einem zweiten Teil sollen diese Kandidaten dann ‚auf Herz und Nieren‘ geprüft werden. Dazu werde ich in Anlehnung an Rüdiger Bittner diskutieren, ob die Kandidaten, die sich im ersten Teil als die plausibelsten erweisen, gewisse Grundanforderungen an Maximen erfüllen (An die auf der Annahme, Maximen seien die hier favorisierten Kandidaten, beruhende Maximenkonzeption gibt es folgende zwei Grundanforderungen: erstens die Möglichkeit der Explikation, was es heißt, dass eine Maxime vorliegt, auch wenn ihr nicht gefolgt wird, zweitens die Möglichkeit der Unterscheidung zwischen dem Befolgen einer Maxime und dem Handeln lediglich gemäß einer Maxime. Und ich werde mich dazu ferner der Frage widmen, ob bestimmte Kritiken, die an – nicht identischen, aber – ähnlichen Kandidaten für Maximen vorgebracht wurden, auch für die hier präsentierten Kandidaten einschlägig sind. Schließlich werde ich in diesem zweiten Teil noch gewisse Schwächen der von mir favorisierten Maximenkonzeptionen erläutern, die man unabhängig von Bittners Kritikpunkten konstatieren könnte.

  14. Strain mapping along Al-Pb interfaces

    International Nuclear Information System (INIS)

    Local strains at particle-matrix hetero-interfaces in an Al-Pb composite produced by high-energy ball-milling were measured by means of geometric phase analysis (GPA) on the basis of high-resolution transmission electron microscope (HRTEM) images. A through-focus series of 10 experimental micrographs was used to retrieve the complex exit-face wave function and subsequently to calculate the components of the strain tensor using Pb as the reference lattice. The strain analysis revealed considerable strain for the interface regions with compressive strain for the Pb side and tensile strain for the Al side. The strained zones extend up to 2-3 lattice spacings on either side of the interface. The interface regions are not sheared or significantly rotated, which shows that the whole state of the interface is elastically strained but not plastically deformed. A new possible interpretation of the melting behaviour of the Pb particles in terms of the strains is discussed.

  15. Mechanical alloying of Ge with Al

    International Nuclear Information System (INIS)

    Mechanical Alloying (MA) is a useful tool for producing homogeneous materials far from thermodynamic equilibrium. This technique enhances the solubility of a solute in a solvent. A project has been initiated for preparing Al-Ge alloys with different concentration of Ge by high-energy ball milling. Four Al- x wt%Ge (x = 2,5,8 and 11) alloys using ball to powder ratio of 20:1 were produced. Scanning electron microscope (SEM) attached with electron probe micro analyzer (EPMA) is used to characterize the microstructure after milling. Agglomerates of powder particles after milling were observed and the size of the agglomerates increased with the increase in milling time up to 100h. Flakes and multi layers structure were observed after 120h milling. X-ray diffraction (XRD) patterns show that more milling is required for the complete homogenization of the alloy. Micro hardness increases with the increase in milling time. In this paper preliminary results would be presented and discussed. (author)

  16. Aproximación psicológica al comportamiento de automedicación

    Directory of Open Access Journals (Sweden)

    Natalia Díaz-Caycedo

    2014-05-01

    Full Text Available La automedicación es un fenómeno global creciente que tradicionalmente se ha definido como la acción individual de consumir un medicamento o seguir un tratamiento sin prescripción médica. Sin embargo, esta visión se ha quedado corta ante las manifestaciones contemporáneas del fenómeno que van más allá del autocuidado y se asocia cada vez más al consumo masivo de medicamentos inducido por la publicidad. En ese sentido, este artículo presenta las definiciones y las teorías explicativas de la automedicación ofrecidas por la literatura científica, especialmente aquellas que enfatizan en la dimensión del autocuidado (por ejemplo, el concepto de la Zoofarmacognosia y desarrolla una nueva hipótesis sobre la automedicación, como comportamiento individual de consumo, explicada por un posicionamiento cognitivo causal simple acerca de la acción de los medicamentos, facilitado por la publicidad y el mercadeo de estos. Se concluye al mostrar la importancia de contrarrestar el efecto de la publicidad mediante la educación del consumidor acerca del riesgo que implica la complejidad de la automedicación a partir de la acción de los medicamentos en el organismo.

  17. Wet chemical etching of AlN and InAlN in KOH solutions

    Energy Technology Data Exchange (ETDEWEB)

    Vartuli, C.B.; Pearton, S.J.; Lee, J.W.; Abernathy, C.R.; Mackenzie, J.D. [Univ. of Florida, Gainesville, FL (United States). Dept. of Materials Science and Engineering; Zolper, J.C.; Shul, R.J. [Sandia National Labs., Albuquerque, NM (United States); Ren, F. [Bell Labs., Murray Hill, NJ (United States). Lucent Technologies

    1996-11-01

    Wet chemical etching of AlN and In{sub x}Al{sub 1{minus}x}N was investigated in KOH-based solutions as a function of etch temperature and material quality. The etch rates for both materials increased with increasing etch temperatures, which was varied from 20 to 80 C. The crystal quality of AlN prepared by reactive sputtering was improved by rapid thermal annealing at temperatures to 1,100 C, with a decreased wet etch rate of the material measured with increasing anneal temperature. The etch rate decreased approximately an order of magnitude at 80 C etch temperature after an 1,100 C anneal. The etch rate for In{sub 0.19}Al{sub 0.81}N grown by metallorganic molecular beam epitaxy was approximately three times higher for material on Si than on GaAs. This corresponds to the superior crystalline quality of the material grown on GaAs. Etching of In{sub x}Al{sub 1{minus}x}N was also examined as a function of In composition. The etch rate initially increased as the In composition changed from 0 to 36%, and then decreased to 0 {angstrom}min for InN. The authors also compared the effect of doping concentration on etch rate. Two InAlN samples of similar crystal quality were also etched; one was fully depleted with n < 10{sup 16} cm{sup {minus}3} (2.6% In) and the other n {approximately} 5 {times} 10{sup 18} cm{sup {minus}3} (3.1% In). At low etch temperature, the rates were similar, but above 60 C the n-type sample etched faster, approximately three times faster at 80 C. The activation energy for these etches is very low, 2.0 {+-} 0.5 kcal/mol for the sputtered AlN. The activation energies for InAlN were dependent on In composition and were in the range 2 to 6 kcal/mol. GaN and InN layers did not show any etching in KOH at temperatures up to 80 C.

  18. Al-Qahira al-Jahida : A Novel of Najib Mahfouz

    OpenAIRE

    Abu tahir mahmood

    2012-01-01

    Among the major figures in the development of Arabic fiction, none has received higher international acclaim than Najib Mahfouz (1911-2006), who in 1988 became the first Arab writer to win the Noble Prize for literature. He was an inspiration to all writers, not just on account of his genius but also through the example of his determination and dedication. Mahfouz pushed the Arabic novel and particularly al-Qahira al-Jadida forward by leaps and bounds, in terms of structure, characterization,...

  19. Effect of al content on reaction laser sintering of Ni-Al powder

    Directory of Open Access Journals (Sweden)

    Qin L.

    2008-01-01

    Full Text Available Laser reactive sintering, i.e., laser-induced self-propagating reaction sintering synthesis was used for the preparation of nickel aluminide intermetallic compounds. The experimental parameters controlling the ignition step such as ignition time and adiabatic temperature were calculated as a function of initial stoichiometry. Al mole ratio in initial powder mixture was varied from 25% to 50% for controlling adiabatic temperature. The increase in Al powder content resulted in the rise in adiabatic temperature and the morphology change of nickel aluminide compounds from needle-like to blocky.

  20. Wetting kinetics and bonding of Al and Al alloys on {alpha}-SiC

    Energy Technology Data Exchange (ETDEWEB)

    Laurent, V. [Ecole Nationale Superieure d`Electrochimie et d`Electrometallurgie, 38 - Grenoble (France). Lab. de Thermodynamique et Physico-Chimie Metallurgiques; Rado, C. [Ecole Nationale Superieure d`Electrochimie et d`Electrometallurgie, 38 - Grenoble (France). Lab. de Thermodynamique et Physico-Chimie Metallurgiques; Eustathopoulos, N. [Ecole Nationale Superieure d`Electrochimie et d`Electrometallurgie, 38 - Grenoble (France). Lab. de Thermodynamique et Physico-Chimie Metallurgiques

    1996-01-01

    The wetting behaviour of aluminium on basal planes of {alpha}-SiC single crystals was investigated between 1000 and 1200 K by the sessile drop technique in high vacuum. The experiments were focused on wetting kinetics to determine the mechanisms controlling the rate of spreading and to identify all the characteristic contact angles formed during an isothermal experiment. Pure Al and Al alloys with silicon, copper and tin were studied. In some experiments SiC substrates covered by a silica layer 10-50 nm thick were used. (orig.)

  1. UNDERSTANDING THE MULTIDIMENSIONAL ISLAMIC FAITH THROUGH ‘ABD AL-GHANI AL-NABULUSI’S MYSTICAL PHILOSOPHY

    OpenAIRE

    Naoki Yamamoto

    2013-01-01

    This paper tries to present a new perspective on Islamic faith and Muslim identity to Muslim minorities who are challenged in practicing or following Islamic law in non-Islamic countries or non-Muslims in the contemporary world. It will uncover the multidimensional perspective of the concept of faith based on sin (dhanb) and repentance (tawbah) through the mystical philosophy of a Syrian scholar, Abd al-Ghani al-Nabulusi (d. 1143/1741) of the 18th century Ottoman Damascus who contributed to t...

  2. Martensitic Transformation in CuAlMn and CuAlNi Melt Spun Ribbons

    OpenAIRE

    Dutkiewicz, J.; Morgiel, J.; Czeppe, T.; Cesari, E.

    1997-01-01

    The martensitic transformation was studied in CuAlMn and CuAlNi alloys transforming at elevated temperatures i.e. 70 - 250 °C. All alloys possessed mixed 18R and 2H structure of martensite. Splat quenching caused a direct formation of martensite and a considerable decrease of the grain size from about 100 µm in the bulk (in spite of TiB additions) down to about 2 µm. The martensite was less prone to stabilization as in bulk water quenched alloys. The DO3 domains size was not altered in rib...

  3. Crystalline Textures on the Al-Ni-Co Quasicrystal Surface

    OpenAIRE

    Erbudak, Mehmet; LONGCHAMP, Jean-Nicolas; Weisskopf, Yves

    2005-01-01

    We have generated cubic Al alloys as commensurate single crystals on the tenfold-symmetry surface of the quasicrystalline Al-Ni-Co alloy by ion bombarding its surface. We find that the crystal-quasicrystal interface contains several alignments of mutual high-symmetry directions and planes. In order to explore the structural matching conditions at the crystal-quasicrystal interface, we have grown Al films on the decagonal surface of Al-Ni-Co by vapor deposition. The initial growth mo...

  4. Aluminum metabolism studied by 26Al tracer using AMS technique

    International Nuclear Information System (INIS)

    By accelerator mass spectrometry (AMS), we studied aluminum metabolism using 26Al as a tracer. To investigate the role of aluminum toxicity in the etiology of amyotrophic lateral sclerosis (ALS) and Alzheimer's disease, aluminum incorporation into the rat cerebrum was studied. When healthy rats were injected intraperitoneally with 26Al, a considerable amount of the tracer was incorporated into the brain within only 5 days after the injection. This 26Al accumulation was apparently irreversible, since it persisted even after 75 days. (author)

  5. New Ti alloy without Al and V for medical implants

    Energy Technology Data Exchange (ETDEWEB)

    Okazaki, Y. [Ministry of Int. Trade and Ind., Tsukuba, Ibaraki (Japan). Mech. Eng. Lab.; Ito, Y. [Kobe Steel Ltd., Tokyo (Japan). Titanium Metals Technology Dept.

    2000-05-01

    The use of the titanium alloy TiAl6V4 for implants is increasing, although the elements Al and V do not show favorable tissue reactions. Therefore the authors developed a new Ti alloy without V and Al. The tests for corrosion resistance, mechanical properties and biocompatibility reveal that the new Zr-, Nb-, and Ta-containing alloy may replace TiAl6V4. (orig.)

  6. Thermo-Mechanical Behavior of NiAl Thin Films

    OpenAIRE

    Wellner, Patrick

    2003-01-01

    Dünne Schichten auf der Basis von intermetallischem NiAl finden ihren Einsatz als Schutzschichten für Hochtemperaturanwendungen aufgrund ihrer ausgezeichneten Oxidationsbeständigkeit. Mangelnde mechanische Stabilität der Schichten kann allerdings durch das Auftreten von thermischen Spannungen zum Schichtversagen führen. In dieser Arbeit wird der Einfluss der Schichtdicke (0.2 bis 3.1 µm) und des Al-Gehalts (45 bis 52 at % Al) auf die Bruchzähigkeit und den Widerstand gegenüber plas...

  7. Enhancement of CO detection in Al doped graphene

    OpenAIRE

    Ao, Z. M.; Yang, J.; Li, S.; Jiang, Q.

    2008-01-01

    A principle of enhancement CO adsorption was developed theoretically by using density functional theory through doping Al into graphene. The results show that the Al doped graphene has strong chemisorption of CO molecule by forming Al-CO bond, where CO onto intrinsic graphene remains weak physisorption. Furthermore, the enhancement of CO sensitivity in the Al doped graphene is determined by a large electrical conductivity change after adsorption, where CO absorption leads to...

  8. ACOUSTIC EMISSION DURING DEFORMATION OF Al-Li ALLOYS

    OpenAIRE

    Furukawa, M.; Miura, Y.; Nemoto, M.

    1987-01-01

    The relationship between tensile elongation and acoustic emission (AE) detected during compressive deformation of Al-Li and Al-Li-Zr alloys has been investigated for a range of microstructure. For comparison, AE measurements have been carried out for Al-Cu and commercial 7050 alloys. In the polycrystalline binary Al-Li alloys, the most pronounced AE was detected in the underaged condition during the onset of plastic deformation. The AE increased with increasing Li content, attained a maximum ...

  9. Growth of Al on a W(110) surface

    International Nuclear Information System (INIS)

    Using low energy electron diffraction and low energy ion scattering spectroscopy, we investigated the growth mode of Al on a W(110) surface at room temperature and at 1000 K. We found that Al grew on the W(110) surface in the Frank–van der Merwe mode when the W substrate was kept at room temperature during Al deposition. It was found that at a coverage higher than 2 monolayer (ML) in Al grown at room temperature, Al atoms had a well-ordered face centered cubic (fcc) (111) surface. The [11¯0] direction of the Al grown at room temperature on the (111) surface was parallel to the [001] direction of the W(110) substrate surface. When the temperature of the W substrate was kept at 1000 K, the adsorbed Al atoms grew in the Volmer–Weber mode. The 1.5 ML Al/W(110) surface prepared at 1000 K shows two domains of the fcc Al(111) surfaces along with a W(110) surface. We also found that the early stage of Al film growth shows W(110) structure. However as the film becomes thicker (above 3.5–4 layers) the Al face is turned into fcc (111) face. - Highlights: ? We investigated the growth behavior of Al on the W(110) surface. ? Al grew in the Frank–van der Merwe mode when the W was kept at room temperature. ? Al grew in the Volmer–Weber mode when the W was kept at 1000 K. ? The Al film grown at room temperature has the (111) surface. ? [11¯0] direction on the Al(111) was the same as [001] on the W(110) substrate.

  10. Seminoma: puesta al día / Seminoma: an update

    Scientific Electronic Library Online (English)

    B., Álvarez Moratinos; S., Angulo Acosta; J., Barrio Cortes; G., García González; A., Domínguez Gordillo; J.C., Alpuente Román; A., Moreno Reyes; JA., Cabrera Cabrera.

    2013-03-01

    Full Text Available Objetivos: Revisar y actualizar los aspectos epidemiológicos, factores de riesgo (con especial atención a los aspectos genéticos e inmunohistoquímicos), diagnósticos y terapéuticos del seminoma. Material y Métodos: Se ha realizado una revisión de la literatura en la base de datos PUBMED, utilizando [...] la palabra clave principal »seminoma», y los subtítulos (subheadings) «diagnóstico», «epidemiologia», «etiología», «genética, «mortalidad» y «tratamiento», sin restricciones en cuanto al tipo de estudio, seleccionando aquellos artículos considerados de interés para una revisión. La información se ha completado con otras fuentes bibliográficas como guías clínicas de referencia, registros de cáncer y tratados de Oncología y Urología. Se ha restringido la búsqueda a artículos en inglés o castellano. Así mismo se ha utilizado el Programa de Vigilancia, Epidemiología y Resultados Finales del Instituto Nacional del Cáncer (SEER) para obtener datos de incidencia y mortalidad de cáncer en los Estados Unidos, y de GLOBOCAN para los datos referentes a otros 184 países del mundo. Resultados: Se han revisado un total de 3.131 artículos, con un periodo de búsqueda objeto de la revisión comprendido entre el 1 de enero de 1990 y el 31 de marzo del 2012, incluyendo un total de 51 revisiones sobre la epidemiología del tumor, 23 sobre los factores de riesgo genético, 66 revisiones sobre los distintos aspectos del diagnóstico y tratamiento, un estudio prospectivo y tres estudios randomizados, incluyéndose así mismo las directrices de 3 Guías Clínicas. Conclusiones: El tumor de células germinativas del testículo (TCGT) supone el tumor sólido más frecuente en los varones entre los 20 y 34 años, representando, el seminoma, entre el 40 y el 50% de todos ellos. Los factores de riesgo son múltiples, congénitos y adquiridos, destacándose entre ellos la predisposición familiar y bilateralidad, la criptorquidia y la acción de determinados agentes carcinógenos químicos considerados como disruptores endocrinos, que podrían favorecer el desarrollo de estos tumores. El aumento del volumen testicular y la palpación de un nódulo duro, doloroso o no, y de tamaño variable es el síntoma más frecuente de presentación. En el diagnóstico juega un importante papel la ecografía testicular y los marcadores tumorales AFP y ?-hCG, sustancias onco-fetales que, además, son muy útiles en la estadificación y monitoreo de la respuesta al tratamiento. Actualmente se disponen de tres sistemas de estadificación de estos tumores que, utilizados de manera conjunta, permiten al equipo multidisciplinar realizar un tratamiento adaptado al riesgo, alcanzándose tasas de supervivencia específica superiores al 98% a los 5 años. El tratamiento del seminoma en el estadio I es la orquiectomía radical como primer gesto terapéutico, existiendo algunas discrepancias sobre el tratamiento adyuvante. Actualmente se consideran tres opciones: la vigilancia, la quimioterapia basada en derivados del platino y la radioterapia. Para los estadios II y III, las opciones tras la cirugía radical son la radioterapia con o sin quimioterapia. Abstract in english Objectives: To review and update the epidemiological aspects, risk factors (mainly genetic and immunohistochemical aspects), diagnosis and treatment of the seminoma. Material and Methods: A literature review has been carried out, using the keyword «seminoma» and the subheadings «diagnosis», «epidemi [...] ology», «etiology», «genetics», «mortality» and «treatment» without restrictions on types of study, selecting those articles considered of interest for a review. Information has been completed with other bibliographic references as clinical guidelines, cancer registries and Oncology and Urology texts. The search was limited to articles in English and Spanish. The Surveillance, Epidemiology and End Results Program (SEER) has also been used to obtain data on cancer incidence and mortality in the US, while GLOBOCAN was utilized to

  11. Seminoma: puesta al día Seminoma: an update

    Directory of Open Access Journals (Sweden)

    B. Álvarez Moratinos

    2013-03-01

    Full Text Available Objetivos: Revisar y actualizar los aspectos epidemiológicos, factores de riesgo (con especial atención a los aspectos genéticos e inmunohistoquímicos, diagnósticos y terapéuticos del seminoma. Material y Métodos: Se ha realizado una revisión de la literatura en la base de datos PUBMED, utilizando la palabra clave principal »seminoma», y los subtítulos (subheadings «diagnóstico», «epidemiologia», «etiología», «genética, «mortalidad» y «tratamiento», sin restricciones en cuanto al tipo de estudio, seleccionando aquellos artículos considerados de interés para una revisión. La información se ha completado con otras fuentes bibliográficas como guías clínicas de referencia, registros de cáncer y tratados de Oncología y Urología. Se ha restringido la búsqueda a artículos en inglés o castellano. Así mismo se ha utilizado el Programa de Vigilancia, Epidemiología y Resultados Finales del Instituto Nacional del Cáncer (SEER para obtener datos de incidencia y mortalidad de cáncer en los Estados Unidos, y de GLOBOCAN para los datos referentes a otros 184 países del mundo. Resultados: Se han revisado un total de 3.131 artículos, con un periodo de búsqueda objeto de la revisión comprendido entre el 1 de enero de 1990 y el 31 de marzo del 2012, incluyendo un total de 51 revisiones sobre la epidemiología del tumor, 23 sobre los factores de riesgo genético, 66 revisiones sobre los distintos aspectos del diagnóstico y tratamiento, un estudio prospectivo y tres estudios randomizados, incluyéndose así mismo las directrices de 3 Guías Clínicas. Conclusiones: El tumor de células germinativas del testículo (TCGT supone el tumor sólido más frecuente en los varones entre los 20 y 34 años, representando, el seminoma, entre el 40 y el 50% de todos ellos. Los factores de riesgo son múltiples, congénitos y adquiridos, destacándose entre ellos la predisposición familiar y bilateralidad, la criptorquidia y la acción de determinados agentes carcinógenos químicos considerados como disruptores endocrinos, que podrían favorecer el desarrollo de estos tumores. El aumento del volumen testicular y la palpación de un nódulo duro, doloroso o no, y de tamaño variable es el síntoma más frecuente de presentación. En el diagnóstico juega un importante papel la ecografía testicular y los marcadores tumorales AFP y ?-hCG, sustancias onco-fetales que, además, son muy útiles en la estadificación y monitoreo de la respuesta al tratamiento. Actualmente se disponen de tres sistemas de estadificación de estos tumores que, utilizados de manera conjunta, permiten al equipo multidisciplinar realizar un tratamiento adaptado al riesgo, alcanzándose tasas de supervivencia específica superiores al 98% a los 5 años. El tratamiento del seminoma en el estadio I es la orquiectomía radical como primer gesto terapéutico, existiendo algunas discrepancias sobre el tratamiento adyuvante. Actualmente se consideran tres opciones: la vigilancia, la quimioterapia basada en derivados del platino y la radioterapia. Para los estadios II y III, las opciones tras la cirugía radical son la radioterapia con o sin quimioterapia.Objectives: To review and update the epidemiological aspects, risk factors (mainly genetic and immunohistochemical aspects, diagnosis and treatment of the seminoma. Material and Methods: A literature review has been carried out, using the keyword «seminoma» and the subheadings «diagnosis», «epidemiology», «etiology», «genetics», «mortality» and «treatment» without restrictions on types of study, selecting those articles considered of interest for a review. Information has been completed with other bibliographic references as clinical guidelines, cancer registries and Oncology and Urology texts. The search was limited to articles in English and Spanish. The Surveillance, Epidemiology and End Results Program (SEER has also been used to obtain data on cancer incidence and mortality in the US, while GLOBOCAN was utilized to obtain data on other 184 countries.

  12. Individual two level fluctuators in the tunneling conductance of Al/AlOx/Al Josephson junctions for superconducting qubits

    Science.gov (United States)

    Nugroho, Christopher; Orlyanchik, Vladimir; van Harlingen, Dale

    2014-03-01

    Two level system (TLS) defects in AlOx tunnel barriers can lead to low-frequency 1 / f critical current noise and losses in coherent superconducting circuits. Understanding the nature of these defects and how to eliminate them are critical in order to achieve ultra-long coherence times. We present measurements of the tunneling conductance of ultrasmall, A quantum-limited tunneling at lower temperatures. Tracking the TLS switching rates as a function of the applied voltage bias provides an estimate of the TLS charge dipole moment. In some quantum tunneling limited TLSs we have observed a non-equilibrium enhancement of the switching rates that cannot be explained by simple dissipative heating of the TLSs. Further investigations into these TLS defects may lead to the identification of their physical origins and strategies to eliminate them. Research funded by the Intelligence Advanced Research Projects Activity (IARPA).

  13. MCrAlY bond coat with enhanced Yttrium layer

    Energy Technology Data Exchange (ETDEWEB)

    Jablonski, Paul D; Hawk, Jeffrey A

    2015-04-21

    One or more embodiments relates to an MCrAlY bond coat comprising an MCrAlY layer in contact with a Y--Al.sub.2O.sub.3 layer. The MCrAlY layer is comprised of a .gamma.-M solid solution, a .beta.-MAl intermetallic phase, and Y-type intermetallics. The Y--Al.sub.2O.sub.3 layer is comprised of Yttrium atoms coordinated with oxygen atoms comprising the Al.sub.2O.sub.3 lattice. Both the MCrAlY layer and the Y--Al.sub.2O.sub.3 layer have a substantial absence of Y--Al oxides, providing advantage in the maintainability of the Yttrium reservoir within the MCrAlY bulk. The MCrAlY bond coat may be fabricated through application of a Y.sub.2O.sub.3 paste to an MCrAlY material, followed by heating in a non-oxidizing environment.

  14. Al-Zarqawi - terrorist või kangelane? / Kalev Kask

    Index Scriptorium Estoniae

    Kask, Kalev

    2005-01-01

    Ilmunud ka: Meie Maa 29. juuni lk. 5. Jordaanias sündinud palestiinlane Abu Musab al-Zarqawi, õige nimega Ahmed Fadel al-Khalaylah, on rühmituse Jama'at al-Tawhid wal Jihad juht ja hetkel kuulsaim sõjapealik Iraagis, kes on pühendanud oma elu võitlusele USA vastu

  15. Morphology stability of Al3BC phase in aluminum alloys

    International Nuclear Information System (INIS)

    Highlights: • Al3BC show hexagonal prism and tetrakaidecahedron morphologies. • The morphology and size of Al3BC remain stable at 1073–1573 K. • The growth mechanism of Al3BC crystals was proposed. • The strengthening effect of Al3BC on A356 alloy was investigated. -- Abstract: In this work, Al3BC was synthesized as the main reaction product in an Al–8B–2C master alloy by using the liquid–solid sintering reaction method. Morphologies of Al3BC crystals were investigated by field emission scanning electron microscopy (FESEM), which indicated that the morphology as well as the size of Al3BC remain stable at 1073–1573 K and its growth mechanism was also discussed. Since {101¯1} facets have the highest growth rate, Al3BC crystal tends to form the hexagonal prism (equilibrium crystal shape), with {101¯0} and {0 0 0 1} (or {0 0 0 3}) facets being exposed. However, Al3BC crystal also appears in tetrakaidecahedron (non-equilibrium shape), caused by the melt environment. Furthermore, the effect of Al3BC on the tensile strength and elongation of A356 alloy was studied. This work enriches the morphological characteristics about Al3BC and puts forward a new strengthening phase in particle-reinforced composite area

  16. Magnetic phase transition of TbPdAl

    International Nuclear Information System (INIS)

    TbPdAl crystallizes in an orthorhombic low-temperature modification (LTM) with TiNiSi-type structure and in a hexagonal high-temperature modification (HTM) with ZrNiAl-type structure. Powder neutron diffraction experiments on TbPdAl were started to investigate magnetic phase transitions of LTM and HTM samples. (author) 3 figs., 2 refs

  17. Optical dispersion and thermal expansion of garnets Lu3Al5O12, Er3Al5O12, Y3Al5O12

    International Nuclear Information System (INIS)

    The thermal expansion coefficients of Lu3Al5O12, Er3Al5O12, Y3Al5O12 garnets for 290-1570 K are determined according to the temperature dependences of the lattice parameters. The refractive indexes of these garnets are measured in the 0.435-1.25 ?m wavelength range using the least deviation method and the coefficients in the dispersion formulae are calculated

  18. Dilatometry and differential scanning calorimetry of Al-U3Si2, Al-UAlx and Al-U3O8 fuel composites

    International Nuclear Information System (INIS)

    In the present paper, coefficient of linear expansion, specific heat and melting point of Al-36 v/o U3Si2, Al-30 v/o UAlx and Al-30 v/o U3O8 fuel composites were measured between room temperature and 550 degC using a high temperature dilatometer differential scanning calorimeter. (author). 4 refs. 4 figs., 1 tab

  19. MARINE BIOLOGICAL REPORT IN THE NU?BAT AL-DAHR F? ?A?Â?IB AL-BARR WA-AL-BA?R

    DEFF Research Database (Denmark)

    Provencal, Philippe

    2014-01-01

    I det arabiske geografiske værk NU?BAT AL-DAHR F? ?A???IB AL-BARR WA-AL-BA?R (færdigskrevet mellem 1324 og 1327) fra omtales seks dyr fra Adenbugten. Det dreje sig om savrokke, kuglefisk, pilrokke, pindsvinefisk og hvalhaj. Det sidste dyr har ikke kunnet bestemmes. Artiklen bringer en oversættelse af optegnelsen til engelsk samt både en filologisk som en biologisk kommentar.

  20. Improved AlGaN/GaN HEMTs Grown on Si Substrates Using Stacked AlGaN/AlN Interlayer by MOCVD

    International Nuclear Information System (INIS)

    AlGaN/GaN high electron mobility transistors (HEMTs) are grown on 2-inch Si (111) substrates by MOCVD. The stacked AlGaN/AlN interlayer with different AlGaN thickness and indium surfactant doped is designed and optimized to relieve the tensile stress during GaN epitaxial growth. The top 1.0?m GaN buffer layer grown on the optimized AlGaN/AlN interlayer shows a crack-free and shining surface. The XRD results show that GaN(002) FWHM is 480 arcsec and GaN(102) FWHM is 900 arcsec. The AGaN/GaN HEMTs with optimized and non-optimized AlGaN/AlN interlayer are grown and processed for comparison and the dc and rf characteristics are characterized. For the dc characteristics of the device with optimized AlGaN/AlN interlayer, maximum drain current density Idss of 737mA/mm, peak transconductance Gm of 185mS/mm, drain leakage current density Ids of 1.7?A/mm, gate leakage current density Igs of 24.8 ?A/mm and off-state breakdown voltage VBR of 67 V are achieved with Lg/Wg/Lgs/Lgd = 1/10/1/1 ?m. For the small signal rf characteristics of the device with optimized AlGaN/AlN interlayer, current gain cutoff frequency fT of 8.3 GHz and power gain cutoff frequency fmax of 19.9 GHz are achieved with Lg/Wg/Lgs/Lgd = 1/100/1/1 ?m. Furthermore, the best rf performance with fT of 14.5 GHz and fmax of 37.3 GHz is achieved with a reduced gate length of 0.7?m. (condensed matter: electronic structure, electrical, magnetic, and optical properties)