Science.gov

Sample records for stationaere und transiente

  1. Transiente Abstrahlung, Einkopplung und Streuung der Schlitzantennen im EMV-Umfeld

    NASA Astrophysics Data System (ADS)

    Ehlen, T.

    2014-11-01

    The radiation, reception and reradiating of the thin slot antenna with arbitrary transient time waveforms are derived in time domain and compared with numerical field simulation results. The equations are suitable for estimating typical pulsed EMI-Interference responses and penetration through loaded and not loaded slots in metal shields like bluetooth and wlan antennas including the radiation impedance. Examples are given for LEMP, NEMP and HPEM waveforms. The derived formulas are transferred in system theory based block diagrams.

  2. Branchen und Unternehmensbereiche

    NASA Astrophysics Data System (ADS)

    Kramer, Regine

    Dieses Kapitel gibt einen Überblick über die Haupteinsatzgebiete von Mathematikern, Informatikern, Naturwissenschaftlern und Ingenieuren in den wichtigsten Wirtschaftsbranchen und Unternehmensbereichen. Dabei werden ausbildungsnahe Aufgabenbereiche ebenso beschrieben wie eher fachferne Tätigkeiten und neben den klassischen Branchen und Berufsbildern auch neue Tätigkeitsfelder für MINT-Fachkräfte beschrieben.

  3. Information und Kommunikation

    NASA Astrophysics Data System (ADS)

    Wesoly, Michael; Ohlhausen, Peter; Bucher, Michael; Hichert, Rolf; Korge, Gabriele; Schnabel, Ulrich; Gairola, Arun; Reichwald, Ralf; Habicht, Hagen; Möslein, Kathrin; Schwarz, Torsten; Schönsleben, Paul; Scherer, Eric; Schloske, Alexander; Adlbrecht, Gerald; Federhen, Jens

    Wissen ist mittlerweile unverzichtbar für den entscheidenden Vorsprung auf dem Markt. Unabhängig davon, ob sich das Wissen in Innovationen, neuen Produkten und Dienstleistungen oder in der Verbesserung interner Unternehmensprozesse manifestiert: Wissen ist Treiber von Innovation, Wissen bringt Schnelligkeit und Wissen ist die Voraussetzung für Problemlösungen [40]. Wissensmanagement ist daher der Schlüssel für Unternehmenserfolg und bezeichnet den "bewussten und systematischen Umgang mit der Ressource Wissen und den zielgerichteten Einsatz von Wissen in der Organisation“ [6]. In dieser umfassenden Sichtweise ist Wissensmanagement ein Begriff, der Konzepte, Strategien und Methoden umfasst.

  4. Welt und Wirkungsprinzip

    NASA Astrophysics Data System (ADS)

    Landgraf, Werner

    1997-05-01

    Modell einer kausalen Bewirkung der Welt, und logische, geometrische, physikalische Interprätation dieser Kausalmenge und Fortwirkung der frühsten ihrer sukzessiv als echt Neues bewirkten und durch Vorhandenes oder Späteres nicht darstellbaren oder widerrufbaren Ereignisse als Dimensionen und sie verkörpernde primäre Naturkräfte, mit Korrespondenz zur beobachteten Welt und ihrer grundlegendsten Eigenschaften. Wirklich ist nur was wirkt, wo und wie. Entsprechend ist im Bogenelement statt der Eigenzeit die variante Anzahl Wirkungen relevant, 0 ≈ 1/h2 dS2 - 1/tpl2 (dt2 - 1/c2 {dq12 + G02/G2 [dq2,32 - ...]}) mit G0 = c4lpl/Epl ≈ G. Die heutigen Dimensionen und Naturkräfte entstanden in dieser Reihenfolge, haben 'komplementäre' aber gleichwertige statische und dynamische Aspekte, entsprechend ihren Termen in Bogenelement bzw. Vierervektor, aus derem Vergleich sowie mit denen ihrer Nachbarn folgen Grundgleichungen bzw. Erhaltungssätze. Jeweils individuelle Eigenschaften wie ihre Naturkonstante konkretisieren sie und tragen zu gattungsmäßigen wie globale Affinität und Äquivalenzen bei. Ältestes Gebiet oder räumlicher Rand jeder Dimension sind die ersten vom Vorgänger bewirkten Ereignisse, selbst raumzeitlicher Ursprung des Nachfolgers, dort einmalig und ewig maximal rotverschoben fortwirkend und nicht lokalisierbar, um neue Elementareinheiten verschieden und lichtartig mit deren Verhältnis oder dem ihrer globalen Zustandsgrößen als konstanten Anfangsimpuls, Expansion, Längen- oder Ereignisdichte zueinander. Der Übergang vom diskreten Modell weniger Informationen zum Kontinuum und die Korrespondenz zur Physik ist problemlos, Details wie ein kontinuierlicher, abrupter oder ganz fehlender Abfall der Metrik beim ältesten Gebiet sind aber nur durch Beobachtungen entscheidbar. Erörtert werden allgemeine und individuelle Eigenschaften und ihre Konsequenzen der Dimensionen mit ihren Kräften, selbst und im Verhältnis zueinander, etwa ihrer begrenzten

  5. Lymph- und Immunsystem

    NASA Astrophysics Data System (ADS)

    Perry, Steven F.

    Alle Lebewesen müssen sich gegen Eindringlinge wehren. Ihre Abwehrmechanismen wirken auf verschiedenen Ebenen, von übergeordneten Feindvermeidungsstrategien und Putzverhalten bis hin zu molekularen Erkennungs- und Tötungsmechanismen. Da Eindringlinge über Kontaktflächen mit der Außenwelt, wie z.B. Körperoberfläche, Darmwand und Atmungsoberflächen, in den Organismus gelangen, sind an diesen Stellen immer primäre Abwehrmechanismen zu finden. Dazu zählen (1) Schleimabsonderung (Schleimhäute bei allen Schädeltieren, Fischkiemen, epidermale Schleimdrüsen (Fische, Amphibien)), (2) Stoffwechselgifte und antibakteriell wirkende Substanzen in der Haut (Fische, Amphibien) und im Speichel (Amnioten), (3) Flimmerepithelien zum Abtransport von Eindringlingen und (4) starke Keratinbildung in der mehrschichtigen Epidermis und schützende Strukturen wie Schuppen, Federn und Haare (Amnioten) (S. 20). Auch die starke Säurebildung im Magen kann als Schutz gegen Eindringlinge betrachtet werden.

  6. Geoinformation und Staat

    NASA Astrophysics Data System (ADS)

    Zypries, Brigitte

    2002-09-01

    Geoinformationen besaßen als Grundlage militärischer Interventionen schon immer einen hohen Stellenwert für den Staat. Im Zeitalter der modernen Informations- und Kommunikationstechnologien wächst in demokratischen Staaten die Bedeutung von Geodaten weit über den Verteidigungsbereich hinaus. Brigitte Zypries, Staatssekretärin im Bundesministerium des Innern (BMI) und Vorsitzende des Interministeriellen Ausschusses für Geoinformationswesen (IMAGI), sprach mit Dipl.-Geogr. Ute C. Bauerüber die Anwendung und Koordinierung von Geodaten in Politik und Staat.

  7. Integument und Anhangsorgane

    NASA Astrophysics Data System (ADS)

    Schliemann, Harald

    Das Integument umhüllt den Wirbeltierkörper lückenlos. In der embryonalen Mundbucht (Stomodaeum) und der Afterbucht (Proctodaeum) grenzt es an die Auskleidung des Darmrohres. Über die generelle Bedeutung einer Haut als Abgrenzung zwischen Körperinnenraum und Außenmedium hinaus hat es bei Schädeltieren ein breites Spektrum von Funktionen. Die wichtigsten sind: Mechanischer Schutz durch Verhornungen und Verknöch erungen; Wundheilung; Schutz vor Wasserverlust; Schutz vor Infektionen durch bakterizide Drüsensekrete und immunkompetente Zellen; Schutz vor kurzwelliger Strahlung durch Pigmente; Schutz vor Überwärmung durch Schweißdrüsensekrete und Schutz vor Wärmeverlust durch Federn und Haare; Ausbildung lokomotorisch wichtiger Strukturen wie Federn, Flug- und Schwimmhäute, Krallen und Hufe; Redukt ion des Strömungswiderstandes durch Dämpfungshaut; Abgabe von Sekreten zur Ernährung (Milch); Ausbildung von Strukturen zu Nahrungserwerb und_-bearbeitung, z. B. Zähne, Barten;

  8. Milch, Milchprodukte, Analoge und Speiseeis

    NASA Astrophysics Data System (ADS)

    Coors, Ursula

    Die Produktpalette Milch und Erzeugnisse aus Milch beinhaltet Konsummilch, die aus Milch oder Bestandteilen der Milch hergestellten Milcherzeugnisse wie Sauermilch-, Joghurt-, Kefir-, Buttermilch-, Sahne-, Kondensmilch-, Trockenmilch- und Molkenerzeugnisse, Milchmisch- und Molkenmischprodukte (Produkte mit beigegebenen Lebensmitteln), Milchzucker, Milcheiweißerzeugnisse, Milchfette und Käse.

  9. Neuausrichtung und Konsolidierung

    NASA Astrophysics Data System (ADS)

    Grohmann, Heinz

    Mit der Wahl von Wolfgang Wetzel zum Vorsitzenden der Deutschen Statistischen Gesellschaft im Jahre 1972 begann eine 32jährige Ära, in der die praktische und die theoretische Statistik in einem ausgewogenen Verhältnis gepflegt wurden. Ein regelmäßiger vierjähriger Wechsel im Vorsitz stärkte die Gemeinschaft und die praktische wie die wissenschaftliche Arbeit gleichermaßen. Die jährlichen Hauptversammlungen behandelten gesellschaftlich aktuelle wie zukunftsorientierte Themen, und die Ausschüsse sowie weitere Veranstaltungen gaben Gelegenheit zur Förderung und Pflege einer Vielzahl von Arbeitsgebieten der Statistik. Darüber wird nicht nur in diesem Kapitel, sondern auch in den Teilen II und III des Bandes berichtet.

  10. Falten und fliegen: Papierflieger und ihre Physik

    NASA Astrophysics Data System (ADS)

    Gruber, Werner

    2004-09-01

    Mit Papierfliegern können wichtige Eigenschaften der Aerodynamik anschaulich vermittelt werden: ein Blatt Papier, ein paar Faltungen und schon kann man experimentieren. Allerdings sind beim Trimmen des Fliegers einige Punkte zu beachten. Besonders wichtig ist die Y-Stellung der Flügel, die ihm Flugstabilität verleiht. Ist der Flieger fertig, dann gilt es, die dem Modell am besten angepasste Wurftechnik herauszufinden. Dazu variiert man Wurfgeschwindigkeit und Abwurfwinkel. Den Boden kann ein Papierflieger auf vier prinzipiell verschiedenen Flugkurven erreichen: Optimal ist die Gerade, dann fliegt er am weitesten.

  11. Messung und Analyse

    NASA Astrophysics Data System (ADS)

    Bathelt, Hartmut; Scheinhardt, Michael; Sell, Hendrik; Sottek, Roland; Guidati, Sandro; Helfer, Martin

    Für die Beurteilung von Akustik und Fahrkomfort eines Fahrzeugs gilt in der Fahrzeugentwicklung immer noch der alte Grundsatz: "Der Kunde fährt nicht am Prüfstand, sondern auf der Straße“. Daher werden Gesamtbeurteilungen des Entwicklungsstandes und Konkurrenzvergleiche (Benchmarking) nach wie vor auf der Straße durchgeführt, meist auf ausgewählten Fahrbahnen am Prüfgelände oder im Rahmen der regelmäßigen Winter- und Sommererprobungen unter extremen Witterungsverhältnissen.

  12. Getreide, Brot und Feine Backwaren

    NASA Astrophysics Data System (ADS)

    von Grabowski, Hans-Uwe; Rolfe, Birgit

    Getreide und Getreideerzeugnisse sind ebenso wie Brot und Feine Backwaren nach dem Lebensmittel- und Futtermittel-Gesetzbuch (LFGB) [1] Lebensmittel im Sinne des Artikels 2 der VO (EG) Nr. 178/2002 (BasisVO) (s. auch Kap. 1.6/2.4.1/3.2). Gesetzlich festgelegte Begriffsbestimmungen gibt es für diese Lebensmittel nicht. Man muss sich daher allgemeiner Verkehrsauffassungen bedienen, wie sie von der Deutschen Lebensmittelbuch-Kommission in Form von Leitsätzen erarbeitet und veröffentlicht wurden [2]. Der Gesundheitsschutz und der Schutz des Verbrauchers vor Täuschung sind in der Basis-VO und dem LFGB geregelt.

  13. Unternehmens- und Marktstatistik

    NASA Astrophysics Data System (ADS)

    Grömling, Michael; Scheinost, Ulrich

    Deutschland verfügt über ein gut ausgebautes System amtlicher und nicht amtlicher Unternehmens- und Marktstatistiken, das sich in einem fortwährenden Wandel befindet. Wird es sinnvoll genutzt, können für einzelne Marktteilnehmer wie für die gesamte Gesellschaft kostspielige Fehlentwicklungen vermieden werden. Dazu bedarf es eines sachkundigen Überblicks über die Vielfalt der Statistiken und der zwischen ihnen bestehenden Beziehungen sowie einer ständigen Anpassung an die wirtschaftliche Entwicklung. Als eine mögliche Orientierung kann der auf der Güter- und Faktorebene zu beobachtende Wandel dienen. Einer adäquaten Abbildung der ökonomischen Realität stehen in Deutschland mit seiner starken Verrechtlichung der Statistik jedoch mancherlei Schwierigkeiten im Wege. Teilweise tiefgreifende Reformbestrebungen sind vor allem auf europäischer Ebene im Gange. Als eine ergebnisorientierte Innovation für das Gesamtsystem der Unternehmens- und Marktstatistik wird ein modular aufgebautes System vorgestellt, das auch bei unterschiedlichen und sich wandelnden Rahmenbedingungen schrittweise realisiert werden kann.

  14. Datenintegration und Deduplizierung

    NASA Astrophysics Data System (ADS)

    Bleiholder, Jens; Schmid, Joachim

    In Unternehmen liegen viele Daten heutzutage immer seltener vollständig an einem einzigen physikalischen Ort vor, sondern sind weltweit verteilt. Dies liegt zum einen an der immer besser gewordenen Infrastruktur, die eine solche Verteilung auf einfache Art und Weise ermöglicht, und zum anderen an der Tatsache, dass viele Unternehmen weltweit tätig sind. So fallen Daten weltweit an, werden aber jeweils lokal - vor Ort - gespeichert. Daher müssen oft mehrere Datenquellen genutzt werden, um einen aktuellen, vollständigen und genauen Überblick über die vorhandenen Daten zu gewinnen. Datenintegration hilft, indem sie Daten aus mehreren Quellen zusammenführt und einheitlich darstellt. Diese integrierten Daten können genutzt werden, um sich einen Überblick über das Unternehmen zu verschaffen, z.B. wenn Unternehmen fusionieren und nur noch eine Kundendatenbank bestehen bleiben soll, oder wenn zu einem Kunden die Daten aus den verschiedenen Fachabteilungen zusammengeführt werden sollen. Anhand eines solchen Beispiels, der Integration von Kundendaten zu Kfz- und Lebensversicherungen erläutern wir im Folgenden einzelne Techniken.

  15. Mikrostrukturtechnik und Biomaterialien

    NASA Astrophysics Data System (ADS)

    Guber, Andreas E.; Saile, Volker; Weibezahn, Karl-Friedrich

    In der Biomedizintechnik zeichnet sich derzeit ein Trend zu einer verstärkten Miniaturisierung des operativen Instrumentariums und der Peripheriegeräte ab, da zur sicheren Durchführung vieler minimal invasiv auszuführender chirurgischer Eingriffe sehr kleine Instrumente und Zusatzgeräte benötigt werden. Weiterhin werden für verschiedene Anwendungen im Life-Sciences-Bereich, wie z. B. innerhalb der klinischen Diagnostik und der pharmazeutischen Chemie, in zunehmendem Masse Komponenten mit eingearbeiteten Mikrostrukturen benötigt. Mit den inzwischen verfügbaren mikrotechnischen Herstellungsverfahren (siehe Kapitel 40.2) ist man in der Lage, unterschiedliche geometrische Formen von kleinen dreidimensionalen Bauteilen und Baugruppen im Mikrometerbereich zu fertigen. Für spezielle Anwendungen können aber auch Strukturen im Bereich von einigen 100 nm erzeugt werden. Mikrostrukturierte Komponenten und Baugruppen können entweder in Form von Implantaten in den menschlichen Körper gelangen oder in extrakorporal einsetzbaren Geräten zum Einsatz kommen (siehe Kapitel 40.3). Dabei ist zwischen Kurzzeit- und Langzeitimplantaten zu unterscheiden. Typische Kurzzeitimplantate sind beispielsweise Operationsinstrumente während eines operativen Eingriffes und für kurze Zeiträume gelegte Spezialkatheter zur gezielten Entnahme von Körpersäften oder zur temporären Medikamentenapplikation. Zur Kategorie der Langzeitimplantate gehören beispielsweise auf Dauer eingesetzte Gefässendoprothesen (Stents), Herzschrittmacher, Cochleaimplantate, miniaturisierte Medikamentendosiersysteme auf Basis mikrofluidischer Baugruppen (Mikropumpen, Mikrokanäle, etc.), implantierbare Arrays von Mikroelektroden, welche innerhalb der Neurobionik verstärkt Anwendung finden werden, sowie in der Zukunft auch künstliche Organe.

  16. Karamell und Schokolade optimal

    NASA Astrophysics Data System (ADS)

    Eichhorn, Andreas

    In verschiedenen Situationen in Technik, Wirtschaft oder Politik ist man daran interessiert unter einer Anzahl von möglichen Entscheidungen die jeweils beste auszuwählen, also die optimale Entscheidung zu treffen, die den größtmöglichen Nutzen bringt. In den meisten Fällen sind Nutzen und Entscheidungsalternativen nicht exakt gegeben, Entscheidungen werden dann entweder sprachlichargumentativ ausgewählt und begründet oder gar aus dem Bauch heraus gefällt. In manchen Fällen ist es aber möglich, Entscheidungsalternativen und Nutzen in Zahlen und Formeln so auszudrücken, dass über diese Beschreibung im Prinzip die optimalen Entscheidungen und der maximale Nutzen festgelegt sind. Dabei ist zu beachten, dass bei mehreren (gleichzeitig oder hintereinander) zu treffenden Entscheidungen gewisse Abhängigkeiten zu berücksichtigen sind, bezüglich der möglichen Alternativen. Wenn beispielsweise die Umsetzung einer bestimmten (Teil-)Entscheidung mit bestimmten Kosten verbunden wäre, so stünde dieser Geldbetrag für andere Entscheidungen nicht mehr zur Verfügung.

  17. Technikwissenschaft - Erfinden und Entdecken

    NASA Astrophysics Data System (ADS)

    Linnemann, Gerhard

    Umrissen wird das allgemeine Ziel der Technikwissenschaft, konstruktiv zu verwerten und nicht-natürlich Entdeckbares zu erfinden. Wir befinden uns in einer Umwälzung der Technik im Verlauf der wissenschaftlich-technischen Revolution, auf dem Wege zu einem neuen Techniktyp. Dieser schafft und nutzt die künstliche Intelligenz. Dazu benötigt der in der Technik tätige Mensch spezielle Kenntnisse und Erfahrungen in kreativ-konstruktiver, -gestalterischer und erfinderischer Sicht mit dem Einsatz spezieller Strukturen und Sprachen. Vorschläge zur Arbeitsweise in der Technik werden gegeben.Translated AbstractTechnological Science-Invent and DiscoverThe general aim of engineering science is outlined to utilize results constructively and to invent something that cannot be discovered in nature. We are now in a period of transformation of technology in the course of scientific-technological revolution, on the way to a new type of technology. This new type creates and utilizes artificial intelligence. For this, man acitive in this field requires special knowledge and experiences in a creative, constructive, design-oriented and ultimately inventive way by deploying special structures and languages. There are also made some proposals concerning the method of working in the field of technology.

  18. Patentierung und Patentlage

    NASA Astrophysics Data System (ADS)

    Herrmann, Uwe

    Gewerbliche Schutzrechte nehmen in der nationalen Rechts- und Wirtschaftsordnung sowie auch auf internationaler Ebene stetig an Bedeutung zu. Sie dienen dem Schutz geistigen Eigentums und sind für jeden Gewerbetreibenden nicht nur im Hinblick darauf von Bedeutung, eigene Rechte zu sichern, sondern auch insofern von Relevanz, dass ein Verstoß gegen Rechte Dritter zu vermeiden ist. Zu den gewerblichen Schutzrechten gehören unter anderem Kennzeichenrechte, Geschmacksmusterrechte sowie die sogenannten technischen Schutzrechte in Form des Patents sowie des Gebrauchsmusters. Die folgenden Ausführungen befassen sich ausschließlich mit den technischen Schutzrechten und geben eine kurze Einführung in die Voraussetzungen, das Entstehen und den Wegfall sowie in die Wirkungen technischer Schutzrechte. Beleuchtet wird die Situation im Wesentlichen im Hinblick auf nationale technische Schutzrechte, d. h. auf Deutsche Patente und Gebrauchsmuster sowie auf Europäische Patente, die Schutz in Deutschland entfalten. Die Möglichkeit der Erlangung von Schutzrechten im außereuropäischen Ausland wird nur am Rande gestreift.

  19. Tipps und Tricks

    NASA Astrophysics Data System (ADS)

    Häger, Wolfgang; Bauermeister, Dirk

    Hier wollen wir einige uns nützlich erscheinende Hinweise zur Arbeit mit dem Inventor geben. Dabei geht es vor allem darum, das Arbeiten mit dem Inventor zu vereinfachen. Die Beispiele stellen eine unvollständige Aufzählung dar und sollen dazu anregen, nach alternativen Vorgehensweisen zu suchen (hier sei noch einmal ausdrücklich auf das Internet verwiesen).

  20. Kometen und Asteroiden

    NASA Astrophysics Data System (ADS)

    Borgeest, Ulf; Staude, Jakob; Hahn, Gerhard; Harris, Alan W.; Jaumann, Ralf; Köhler, Ulrich; Kührt, Ekkehard; Schulz, Rita; Neukum, Gerhard; Arnold, Gabriele; Keller, Horst Uwe; Denk, Tilmann; Müller, Thomas; Wulff, André; Maruhn, Nicolaus; Fischer, Daniel; Trieloff, Mario; Althaus, Tilmann

    Contents: Die Kleinkörper des Sonnensystems. Kern, Koma und Schweife. Ziele der Planetenforschung. ROSETTA: Naherkundung von Kometen. Asteroiden: Trümmer aus planetarer Urzeit. Kleinkörper im Infrarotweltall. Selbs beobachten! Apocalypse - not now! Meteoriten - Boten aus der Urzeit des Sonnensystems.

  1. Wirkstoffe, Medikamente und Mathematische Bildverarbeitung

    NASA Astrophysics Data System (ADS)

    Bauer, Günter J.; Lorenz, Dirk A.; Maaß, Peter; Preckel, Hartwig; Trede, Dennis

    Die Entwicklung neuer Medikamente ist langwierig und teuer. Der erste Schritt ist hierbei die Suche nach neuen Wirkstoffkandidaten, die für die Behandlung bislang schwer therapierbarer Krankheiten geeignet sind. Hierfür stehen der Pharma- und Biotechnologieindustrie riesige Substanzbibliotheken zur Verfügung. In diesen Bibliotheken werden die unterschiedlichsten Substanzen gesammelt, die entweder synthetisch hergestellt oder aus Pilzen, Bakterienkulturen und anderen Lebewesen gewonnen werden können.

  2. Pyropheophorbide und a as a catabolite of ethylene-induced chlorophyll und a degradation

    SciTech Connect

    Shimokawa, Keishi; Hashizume, Akihito ); Shioi, Yuzo )

    1990-05-01

    An enzyme extract prepared from ethylene-induced degreening Citrus fruits contains chlorophyll (Chl) degrading enzymes. The fate of Chl carbons during an enzymatic degradation was investigated using Chl {und a}-{sup 14}C. Accompanying the disappearance of labelled Chl {und a}, pheophorbide {und a} and pyropheophorbide {und a} appeared and accumulation of pyropheophorbide {und a} was observed. HydroxyChl {und a} was also detected, but this is thought to be an artifact during chromatography. Unlike ethylene-induced Citrus fruits (in vivo), further degradation of pyropheophorbide {und a} did not occur in vitro enzyme system. This suggests that there is a lack of enzyme(s) and/or cofactor(s) for further degradation. It is concluded that Chl {und a} degraded enzymatically by the following order: Chl {und a}, chlorophyllide {und a}, pheophorbide {und a} and pyropheophorbide {und a}.

  3. Bildanalyse in Medizin und Biologie

    NASA Astrophysics Data System (ADS)

    Athelogou, Maria; Schönmeyer, Ralf; Schmidt, Günther; Schäpe, Arno; Baatz, Martin; Binnig, Gerd

    Heutzutage sind bildgebende Verfahren aus medizinischen Untersuchungen nicht mehr wegzudenken. Diverse Methoden - basierend auf dem Einsatz von Ultraschallwellen, Röntgenstrahlung, Magnetfeldern oder Lichtstrahlen - werden dabei spezifisch eingesetzt und liefern umfangreiches Datenmaterial über den Körper und sein Inneres. Anhand von Mikroskopieaufnahmen aus Biopsien können darüber hinaus Daten über die morphologische Eigenschaften von Körpergeweben gewonnen werden. Aus der Analyse all dieser unterschiedlichen Arten von Informationen und unter Konsultation weiterer klinischer Untersuchungen aus diversen medizinischen Disziplinen kann unter Berücksichtigung von Anamnesedaten ein "Gesamtbild“ des Gesundheitszustands eines Patienten erstellt werden. Durch die Flut der erzeugten Bilddaten kommt der Bildverarbeitung im Allgemeinen und der Bildanalyse im Besonderen eine immer wichtigere Rolle zu. Gerade im Bereich der Diagnoseunterstützung, der Therapieplanung und der bildgeführten Chirurgie bilden sie Schlüsseltechnologien, die den Forschritt nicht nur auf diesen Gebieten maßgeblich vorantreiben.

  4. Beschallungstechnik, Beschallungsplanung und Simulation

    NASA Astrophysics Data System (ADS)

    Ahnert, Wolfgang; Goertz, Anselm

    Die primäre Aufgabe einer Lautsprecheranlage ist es, Musik, Sprache oder auch Signaltöne und Geräusche wiederzugeben. Diese können von einem Tonträger kommen (CD, Sprachspeicher), von einem anderen Ort übertragen (Zuspielung über Radio, TV, Telefon) oder vor Ort erzeugt werden. Letzteres umfasst Konzerte, Ansprachen, Durchsagen oder künstlerische Darbietungen, bei denen es meist darum geht, eine bereits vorhandene Quelle einer größeren oder weiter verteilten Anzahl von Personen zugänglich zu machen.

  5. Transient tachypnea - newborn

    MedlinePlus

    TTN; Wet lungs - newborns; Retained fetal lung fluid; Transient RDS; Prolonged transition; Neonatal - transient tachypnea ... As the baby grows in the womb, the lungs make a special fluid. This fluid fills the ...

  6. Faszination Weltall. Sehen und Verstehen.

    NASA Astrophysics Data System (ADS)

    Humphrey, C.

    This book is a German translation, by T. Bührke, of the English original "The amateur astronomer's pathfinder" published in 1992. Contents: 1. Die Erde im Universum. 2. Der Nachthimmel. 3. Die Erforschung von Raum und Zeit.

  7. Renaturierung und Management von Heiden

    NASA Astrophysics Data System (ADS)

    Härdtle, Werner; Assmann, Thorsten; van Diggelen, Rudy; von Oheimb, Goddert

    Heiden zählen zu den ältesten und besonders reizvollen Kulturlandschaften Nordwesteuropas. Sie sind bezeichnend für nährstoffarme Böden in wintermilden Gebieten mit hohen Sommerniederschlägen. Während Heiden vor wenigen Jahrhunderten noch weit verbreitet und für manche Landschaften sogar prägend waren, hat sich ihr Areal heute auf wenige, meist in Naturschutzgebieten gelegene Restbestände verkleinert. Zu diesem Rückgang haben maßgeblich Änderungen der Landnutzung, aber auch Nährstoffeinträge aus umgebenden Agrarflächen und atmogene Depositionen beigetragen. In den meisten Ländern der Europäischen Union sind Heiden heute gesetzlich geschützte Ökosysteme, da diese, neben ihrem Erholungswert für den Menschen, Pflanzen- und Tierarten beherbergen, die außerhalb von Heiden nicht oder kaum überlebensfähig sind.

  8. Komet Halley: Bahnelemente und Perihelzeiten

    NASA Astrophysics Data System (ADS)

    Landgraf, Werner

    1985-02-01

    Verbesserte Bahnelemente und Perihelzeiten -2316 bis 2284 für Komet Halley. Zusammenfassung der für ein breiteres Publikum relevantesten Ergebnisse von "On the Motion of Comet Halley". ESTEC EP/14.7/6184 Final Report

  9. Transient drainage summary report

    SciTech Connect

    1996-09-01

    This report summarizes the history of transient drainage issues on the Uranium Mill Tailings Remedial Action (UMTRA) Project. It defines and describes the UMTRA Project disposal cell transient drainage process and chronicles UMTRA Project treatment of the transient drainage phenomenon. Section 4.0 includes a conceptual cross section of each UMTRA Project disposal site and summarizes design and construction information, the ground water protection strategy, and the potential for transient drainage.

  10. Transient Ischemic Attack

    MedlinePlus

    Transient Ischemic Attack TIA , or transient ischemic attack, is a "mini stroke" that occurs when a blood clot blocks an artery for a short time. The only ... TIA is that with TIA the blockage is transient (temporary). TIA symptoms occur rapidly and last a ...

  11. Welt und Wirkungsprinzip (2nd Aufl.)

    NASA Astrophysics Data System (ADS)

    Landgraf, Werner

    2010-03-01

    Modell einer kausalen Bewirkung der Welt, und logische, geometrische, physikalische Interprätation dieser Kausalmenge und Fortwirkung der frühsten ihrer sukzessiv als echt Neues bewirkten und durch Vorhandenes oder Späteres nicht darstellbaren oder widerrufbaren Ereignisse als Dimensionen und sie verkörpernde primäre Naturkräfte, mit Korrespondenz zur beobachteten Welt und ihrer grundlegendsten Eigenschaften. Wirklich ist nur was wirkt, wo und wie. Entsprechend ist im Bogenelement statt der Eigenzeit die variante Anzahl Wirkungen relevant, 0 ≈ 1/h2 dS2 - 1/tpl2 (dt2 - 1/c2 {dq12 + G02/G2 [dq2,32 - ...]}) mit G0 = c4lpl/Epl ≈ G. Die heutigen Dimensionen und Naturkräfte entstanden in dieser Reihenfolge, haben 'komplementäre' aber gleichwertige statische und dynamische Aspekte, entsprechend ihren Termen in Bogenelement bzw. Vierervektor, aus derem Vergleich sowie mit denen ihrer Nachbarn folgen Grundgleichungen bzw. Erhaltungssätze. Jeweils individuelle Eigenschaften wie ihre Naturkonstante konkretisieren sie und tragen zu gattungsmäßigen wie globale Affinität und Äquivalenzen bei. Ältestes Gebiet oder räumlicher Rand jeder Dimension sind die ersten vom Vorgänger bewirkten Ereignisse, selbst raumzeitlicher Ursprung des Nachfolgers, dort einmalig und ewig maximal rotverschoben fortwirkend und nicht lokalisierbar, um neue Elementareinheiten verschieden und lichtartig mit deren Verhältnis oder dem ihrer globalen Zustandsgrößen als konstanten Anfangsimpuls, Expansion, Längen- oder Ereignisdichte zueinander. Der Übergang vom diskreten Modell weniger Informationen zum Kontinuum und die Korrespondenz zur Physik ist problemlos, Details wie ein kontinuierlicher, abrupter oder ganz fehlender Abfall der Metrik beim ältesten Gebiet sind aber nur durch Beobachtungen entscheidbar. Erörtert werden allgemeine und individuelle Eigenschaften und ihre Konsequenzen der Dimensionen mit ihren Kräften, selbst und im Verhältnis zueinander, etwa ihrer begrenzten

  12. Kernspaltung und Westintegration Beispiel österreich

    NASA Astrophysics Data System (ADS)

    Forstner, Christian

    Während des Kalten Krieges erreichte in Europa sowohl die Verflechtung physikalischer Forschung mit Staat, Politik und Industrie als auch deren öffentliche Verhandlung und Bewertung eine qualitativ neuartige Dimension. Dieser Aspekt tritt am schärfsten in der Geschichte der Kernphysik und Kerntechnik hervor.

  13. [Evidenzbasierte Leitlinien, Anspruch und Wirklichkeit].

    PubMed

    Gutsch, Johannes; Reif, Marcus; Müller-Hübenthal, Boris; Matthiessen, Peter F

    2016-01-01

    Mit der Konzeption der «Evidenzbasierten Medizin» und den «Evidenzbasierten Leitlinien» soll mithilfe von Formalisierungsprozeduren die ärztliche Irrtumsanfälligkeit kalkulierbar gemacht werden. Quantifizierte objektive Aussagen über die therapeutische Wirksamkeit einer Behandlung sollen die individuelle ärztliche Beurteilung der therapeutischen Wirksamkeit überflüssig machen. Damit kommt der Befolgung von formalen Regeln die entscheidende Rolle bei der Beantwortung der Frage nach dem Wahrheitsgehalt und dem Wirklichkeitsbezug zu. Im Rahmen evidenzbasierter Leitlinien werden vorrangig die Ergebnisse randomisierter kontrollierter Studien (RCT) oder Meta-Analysen solcher Studien herangezogen. Am Beispiel der S3-Leitlinie «Malignes Melanom» wird hier eine evidenzbasierte Urteilsbildung zur Wirksamkeit einer unkonventionellen Therapie - hier mit einem Mistelpräparat - analytisch nachvollzogen. Die für die Beurteilung dieser unkonventionellen Therapie herangezogene randomisierte Studie wird genauer methodisch analysiert. Obwohl sie keine statistisch basierte Aussage zulässt, wurde eine Leitlinienempfehlung auf Basis dieser Studie abgeleitet. Es wird gezeigt, dass 1) allein die Existenz einer einzigen RCT mit hoher Evidenz gleichgesetzt wird, 2) die Ergebnisse trotz beträchtlicher Fehlinterpretationen in eine S3-Leitlinie einfließen und 3) Meinungen anstelle kritischer wissenschaftlicher Analysen verarbeitet werden. Unsere Untersuchung zeigt, dass noch so ausgefeilte epistemologische und methodologische Formalien den Arzt nicht von der Pflicht entbinden, auf Basis seiner ärztlichen Erfahrung und professionellen Kompetenz den Realitätswert der ihm zur Verfügung stehenden Information zu beurteilen. PMID:27161555

  14. [Vegetarische und vegane Ernährung bei Kindern - Stand der Forschung und Forschungsbedarf].

    PubMed

    Keller, Markus; Müller, Stine

    2016-01-01

    Die Praxis vegetarischer Ernährungsformen ist in Deutschland im letzten Jahrzehnt deutlich angestiegen. Allerdings ist der Anteil vegetarischer und veganer Kinder dabei unbekannt. Studien mit Erwachsenen zeigen das präventive Potenzial, aber auch potenzielle Schwachstellen pflanzenbasierter Kostformen. Die Vorteile und Risiken einer vegetarischen bzw. veganen Ernährung im Kindesalter wurden bisher jedoch relativ selten untersucht. Außerdem lassen das unterschiedliche Alter der Kinder, das heterogene Studiendesign sowie die teilweise geringe Probandenzahl der Studien keine verbindlichen Aussagen zu. In dieser Übersichtsarbeit werden die Ergebnisse der wenigen Studien zu vegetarisch und vegan ernährten Kindern (< 12 Jahren) in Nordamerika und Europa zusammengefasst. Demnach lag die Zufuhr von Nahrungsenergie und Makronährstoffen vegetarischer und veganer Kinder meist näher an den Empfehlungen der Fachgesellschaften als die Ernährung gleichaltriger Mischkostkinder. Ebenso wiesen vegetarisch und vegan ernährte Kinder eine höhere Zufuhr von und bessere Versorgung mit verschiedenen Vitaminen und Mineralstoffen auf. Häufiger zeigten sich jedoch Defizite bei Vitamin B12, Zink, Kalzium, Eisen und Vitamin D. Das Wachstum und die Entwicklung vegetarisch und vegan ernährter Kinder entsprachen weitgehend den Referenzstandards, wobei sie dazu tendierten, leichter, schlanker und (< 5 Jahren) auch kleiner zu sein. Aufgrund der unzureichenden Studienlage besteht erheblicher Forschungsbedarf zu den Auswirkungen einer vegetarischen und veganen Ernährung im Kindesalter.

  15. [Vegetarische und vegane Ernährung bei Kindern - Stand der Forschung und Forschungsbedarf].

    PubMed

    Keller, Markus; Müller, Stine

    2016-01-01

    Die Praxis vegetarischer Ernährungsformen ist in Deutschland im letzten Jahrzehnt deutlich angestiegen. Allerdings ist der Anteil vegetarischer und veganer Kinder dabei unbekannt. Studien mit Erwachsenen zeigen das präventive Potenzial, aber auch potenzielle Schwachstellen pflanzenbasierter Kostformen. Die Vorteile und Risiken einer vegetarischen bzw. veganen Ernährung im Kindesalter wurden bisher jedoch relativ selten untersucht. Außerdem lassen das unterschiedliche Alter der Kinder, das heterogene Studiendesign sowie die teilweise geringe Probandenzahl der Studien keine verbindlichen Aussagen zu. In dieser Übersichtsarbeit werden die Ergebnisse der wenigen Studien zu vegetarisch und vegan ernährten Kindern (< 12 Jahren) in Nordamerika und Europa zusammengefasst. Demnach lag die Zufuhr von Nahrungsenergie und Makronährstoffen vegetarischer und veganer Kinder meist näher an den Empfehlungen der Fachgesellschaften als die Ernährung gleichaltriger Mischkostkinder. Ebenso wiesen vegetarisch und vegan ernährte Kinder eine höhere Zufuhr von und bessere Versorgung mit verschiedenen Vitaminen und Mineralstoffen auf. Häufiger zeigten sich jedoch Defizite bei Vitamin B12, Zink, Kalzium, Eisen und Vitamin D. Das Wachstum und die Entwicklung vegetarisch und vegan ernährter Kinder entsprachen weitgehend den Referenzstandards, wobei sie dazu tendierten, leichter, schlanker und (< 5 Jahren) auch kleiner zu sein. Aufgrund der unzureichenden Studienlage besteht erheblicher Forschungsbedarf zu den Auswirkungen einer vegetarischen und veganen Ernährung im Kindesalter. PMID:27160086

  16. Restaurierung von Seen und Renaturierung von Seeufern

    NASA Astrophysics Data System (ADS)

    Grüneberg, Björn; Ostendorp, Wolfgang; Leßmann, Dieter; Wauer, Gerlinde; Nixdorf, Brigitte

    Süßwasserseen haben als ökosysteme und Lebensraum für Pflanzen und Tiere eine herausragende Bedeutung für die Artenvielfalt auf der Erde und prägen als Landschaftselemente unsere natürliche Umwelt. Seen fungieren als natürliche Stoffsenken, vor allem für Kohlenstoff und Nährstoffe, aber auch als Senken für in ihren Einzugsgebieten emittierte gelöste und feste Schadstoffe. Darüber hinaus ist Wasser eine wichtige Naturressource. Süßwasserseen stellen in den meisten Regionen der Erde lebenswichtige Quellen für die Versorgung mit Trinkwasser und tierischem Eiweiß (Fischfang) dar. Sie dienen als Wasserspeicher für die landwirtschaftliche und industrielle Nutzung. Auch für Erholungsaktivitäten des Menschen kommt ihnen eine große Bedeutung zu.

  17. Bewegungsapparat: Postcraniales Skelett und Muskulatur

    NASA Astrophysics Data System (ADS)

    Fischer, Martin S.

    Der Bewegungsapparat bestimmt die Form des Wirbeltierkörpers. So lässt sich z. B. aus der Gestalt eines Fisches auf seine bevorzugt e Schwimmweise schließen (S. 61). Bei den aquatisch en Schädeltieren dominiert die Fortbewegung mit axialem Antrieb; bei den meisten Tetrapoda findet sich eine Kombination aus axialem Antrieb und Bewegung durch Gliedmaßen. Selbst beim höchst spezialisierten Gang, der bipeden Bewegung des Menschen, sind Torsionsbewegungen des Rumpfes noch maßgeblich und bestimmen auch die Grundform des menschlichen Körpers (z. B. die Taille). Obwohl die verschiedenen Antriebsmechanismen eine funktionelle Einheit bilden, werden im Folgenden das Axialskelett sowie der Schulter- und Beckengürtel mit den zugehörigen Extremitäten getrennt besprochen.

  18. Kosmologie und Teilchenphysik.

    NASA Astrophysics Data System (ADS)

    Appenzeller, I.

    This book is a selection of 17 articles published in the journal "Spektrum der Wissenschaft". The original English versions of the papers were first published in "Scientific American". Contents: 1. Einführung (I. Appenzeller). 2. Sehr große Strukturen im Universum (J. O. Burns). 3. Die großräumigen Eigenbewegungen der Galaxien (A. Dressler). 4. Dunkle Materie im Universum (L. M. Krauss). 5. Der doppelte Beta-Zerfall (M. K. Moe, S. P. Rosen). 6. Quark-Lepton Familien (D. B. Cline). 7. Beschleunigerexperimente testen kosmologische Theorien (D. N. Schramm, G. Steigman). 8. Das Rätsel der kosmologischen Konstanten (L. Abbott). 9. Das Higgs-Boson (M. J. G. Veltman). 10. Die Suche nach dem Protonenzerfall (J. M. LoSecco, F. Reines, D. Sinclair). 11. Das inflationäre Universum (A. H. Guth, P. J. Steinhardt). 12. Die fünfte Dimension (E. Schmutzer). 13. Die verborgenen Dimensionen der Raumzeit (D. Z. Freedman, P. van Nieuwenhuizen). 14. Ist die Natur supersymmetrisch? (H. E. Haber, G. L. Kane). 15. Schwerkraft und Antimaterie (T. Goldman, R. J. Hughes, M. M. Nieto). 16. Superstrings (M. B. Green). 17. Kosmische Strings (A. Vilenkin).

  19. Perception of acoustic transients

    NASA Astrophysics Data System (ADS)

    Howard, J. H., Jr.

    1984-01-01

    The research investigates the role of knowledge based or top-down processing in the perception of nonlinguistic, transient signals. The experiments address issues in transient pattern classification, target observation, attentional focusing, auditory induction, and computer based performance aids. The theoretical significance and naval relevance of the research is considered.

  20. High-energy transients.

    PubMed

    Gehrels, Neil; Cannizzo, John K

    2013-06-13

    We present an overview of high-energy transients in astrophysics, highlighting important advances over the past 50 years. We begin with early discoveries of γ-ray transients, and then delve into physical details associated with a variety of phenomena. We discuss some of the unexpected transients found by Fermi and Swift, many of which are not easily classifiable or in some way challenge conventional wisdom. These objects are important insofar as they underscore the necessity of future, more detailed studies. PMID:23630376

  1. Transient nucleation in glasses

    NASA Technical Reports Server (NTRS)

    Kelton, K. F.

    1991-01-01

    Nucleation rates in condensed systems are frequently not at their steady state values. Such time dependent (or transient) nucleation is most clearly observed in devitrification studies of metallic and silicate glasses. The origin of transient nucleation and its role in the formation and stability of desired phases and microstructures are discussed. Numerical models of nucleation in isothermal and nonisothermal situations, based on the coupled differential equations describing cluster evolution within the classical theory, are presented. The importance of transient nucleation in glass formation and crystallization is discussed.

  2. [Transient epileptic amnesia].

    PubMed

    Muramatsu, Kazuhiro; Yoshizaki, Takahito

    2016-03-01

    Transient amnesia is one of common clinical phenomenon of epilepsy that are encountered by physicians. The amnestic attacks are often associated with persistent memory disturbances. Epilepsy is common among the elderly, with amnesia as a common symptom and convulsions relatively uncommon. Therefore, amnesia due to epilepsy can easily be misdiagnosed as dementia. The term 'transient epileptic amnesia (TEA)' was introduced in the early 1990s by Kapur, who highlighted that amnestic attacks caused by epilepsy can be similar to those occurring in 'transient global amnesia', but are distinguished by features brevity and recurrence. In 1998, Zeman et al. proposed diagnostic criteria for TEA.

  3. Abdichtungen im Verbund mit Fliesen und Platten

    NASA Astrophysics Data System (ADS)

    Platts, Thomas

    Abdichtungen im Verbund mit Fliesen und Platten, im Folgenden auch als Verbundabdichtungen oder mit Kurzzeichen als AIV bezeichnet, haben sich in der Baupraxis insbesondere in Innenräumen wegen des vereinfachten konstruktiven Aufbaus gegenüber Bahnenabdichtungen nach DIN 18195-5 [14.1] in der Mehrzahl der Ausführungen durchgesetzt und bewährt. Sie können im Innen- und Außenbereich angeordnet werden und sind dadurch gekennzeichnet, dass die Nutzschicht in Boden- und Wandbereichen im Dünnbettverfahren unmittelbar auf die Abdichtung aufgebracht wird. Aufwändige Zwischenschichten oder Einbauteile wie armierter Putz, Telleranker etc. entfallen (Bild 14.1) und es lassen sich geringere Aufbauhöhen realisieren.

  4. Gamma ray transients

    NASA Technical Reports Server (NTRS)

    Cline, Thomas L.

    1987-01-01

    The discovery of cosmic gamma ray bursts was made with systems designed at Los Alamos Laboratory for the detection of nuclear explosions beyond the atmosphere. HELIOS-2 was the first gamma ray burst instrument launched; its initial results in 1976, seemed to deepen the mystery around gamma ray transients. Interplanetary spacecraft data were reviewed in terms of explaining the behavior and source of the transients.

  5. The LOFAR Transients Pipeline

    NASA Astrophysics Data System (ADS)

    Swinbank, John D.; Staley, Tim D.; Molenaar, Gijs J.; Rol, Evert; Rowlinson, Antonia; Scheers, Bart; Spreeuw, Hanno; Bell, Martin E.; Broderick, Jess W.; Carbone, Dario; Garsden, Hugh; van der Horst, Alexander J.; Law, Casey J.; Wise, Michael; Breton, Rene P.; Cendes, Yvette; Corbel, Stéphane; Eislöffel, Jochen; Falcke, Heino; Fender, Rob; Grießmeier, Jean-Mathias; Hessels, Jason W. T.; Stappers, Benjamin W.; Stewart, Adam J.; Wijers, Ralph A. M. J.; Wijnands, Rudy; Zarka, Philippe

    2015-06-01

    Current and future astronomical survey facilities provide a remarkably rich opportunity for transient astronomy, combining unprecedented fields of view with high sensitivity and the ability to access previously unexplored wavelength regimes. This is particularly true of LOFAR, a recently-commissioned, low-frequency radio interferometer, based in the Netherlands and with stations across Europe. The identification of and response to transients is one of LOFAR's key science goals. However, the large data volumes which LOFAR produces, combined with the scientific requirement for rapid response, make automation essential. To support this, we have developed the LOFAR Transients Pipeline, or TraP. The TraP ingests multi-frequency image data from LOFAR or other instruments and searches it for transients and variables, providing automatic alerts of significant detections and populating a lightcurve database for further analysis by astronomers. Here, we discuss the scientific goals of the TraP and how it has been designed to meet them. We describe its implementation, including both the algorithms adopted to maximize performance as well as the development methodology used to ensure it is robust and reliable, particularly in the presence of artefacts typical of radio astronomy imaging. Finally, we report on a series of tests of the pipeline carried out using simulated LOFAR observations with a known population of transients.

  6. Physik gestern und heute Das Eiskalorimeter

    NASA Astrophysics Data System (ADS)

    Heering, P.

    2003-07-01

    Kalorimetrische Messungen gehören heute zum experimentellen Standardrepertoire im Bereich der Thermodynamik und der physikalischen Chemie. Das erste Gerät für derartige Messungen entwickelten Ende des 18. Jahrhunderts die französischen Wissenschaftler Antoine Laurent Lavoisier und Pierre Simon de Laplace.

  7. Calibration of acoustic transients.

    PubMed

    Burkard, Robert

    2006-05-26

    This article reviews the appropriate stimulus parameters (click duration, toneburst envelope) that should be used when eliciting auditory brainstem responses from mice. Equipment specifications required to calibrate these acoustic transients are discussed. Several methods of calibrating the level of acoustic transients are presented, including the measurement of peak equivalent sound pressure level (peSPL) and peak sound pressure level (pSPL). It is hoped that those who collect auditory brainstem response thresholds in mice will begin to use standardized methods of acoustic calibration, so that hearing thresholds across mouse strains obtained in different laboratories can more readily be compared.

  8. The Transient Universe

    NASA Astrophysics Data System (ADS)

    Shappee, Benjamin John

    When one looks at the night sky, one usually gets the impression of a static and constant universe. Quite apart from appearances, the sky is teeming with violent, variable, and transient events that shape our universe. These capricious objects are not only penetrating probes into physical conditions too extreme for earthbound laboratories, but they are also useful tools to measure the universe. In this dissertation, I investigate the observational and theoretical properties of three classes of transient/variable objects: thermonuclear supernovae, Cepheid variable stars, and active galactic nuclei.

  9. Symmetriebrechung und Emergenz in der Kosmologie.

    NASA Astrophysics Data System (ADS)

    Mainzer, K.

    Seit der Antike wird der Aufbau des Universums mit einfachen und regulären (symmetrischen) Grundstrukturen verbunden. Diese Annahme liegt selbst noch den Standardmodellen der relativistischen Kosmologie zugrunde. Demgegenüber läßt sich die Emergenz neuer Strukturen von den Elementarteilchen über Moleküle bis zu den komplexen Systemen des Lebens als Symmetriebrechung verstehen. Symmetriebrechung und strukturelle Komplexität bestimmen die kosmische Evolution. Damit zeichnet sich ein fachübergreifendes Forschungsprogramm von Physik, Chemie und Biologie ab, in dem die Evolution des Universums untersucht werden kann.

  10. Transient neonatal zinc deficiency.

    PubMed

    Krieger, I; Alpern, B E; Cunnane, S C

    1986-06-01

    We report an infant who developed clinical manifestations of zinc deficiency during the first month of life although the diet was adequate for zinc and no other causes could be ascertained. The diagnosis was confirmed by low plasma-zinc concentrations and a positive response to zinc treatment. The fatty acid profile of plasma phospholipids was typical of zinc deficiency (ie, arachidonic acid was markedly decreased). The transient nature of this disorder was evident when no relapse occurred after cessation of zinc therapy and plasma-zinc and arachidonic acid concentrations remained normal. Several explanations for the development of transient neonatal zinc deficiency are offered. The observation demonstrates that occasional infants may have requirements for zinc that are beyond the intakes of the conventional RDA. PMID:3717070

  11. Reactor System Transient Code.

    1999-07-14

    RELAP3B describes the behavior of water-cooled nuclear reactors during postulated accidents or power transients, such as large reactivity excursions, coolant losses or pump failures. The program calculates flows, mass and energy inventories, pressures, temperatures, and steam qualities along with variables associated with reactor power, reactor heat transfer, or control systems. Its versatility allows one to describe simple hydraulic systems as well as complex reactor systems.

  12. Bright Transients discovered by PSST

    NASA Astrophysics Data System (ADS)

    Smith, K. W.; Wright, D.; Smartt, S. J.; Huber, M.; Chambers, K. C.; Flewelling, H.; Willman, M.; Primak, N.; Schultz, A.; Gibson, B.; Magnier, E.; Waters, C.; Tonry, J.; Wainscoat, R. J.; Denneau, L.; Stalder, B.; Heinze, A.; Sherstyuk, A.; Foley, R. J.; Jha, S. W.; Rest, A.; Scolnic, D.

    2016-04-01

    Seven bright transients have been discovered as part of the Pan-STARRS Survey for Transients (PSST). Information on all objects discovered by the Pan-STARRS Survey for Transients is available at http://star.pst.qub.ac.uk/ps1threepi/ (see Huber et al. ATel #7153).

  13. Bright Transients discovered by PSST

    NASA Astrophysics Data System (ADS)

    Smith, K. W.; Wright, D.; Smartt, S. J.; Huber, M.; Chambers, K. C.; Flewelling, H.; Willman, M.; Primak, N.; Schultz, A.; Gibson, B.; Magnier, E.; Waters, C.; Tonry, J.; Wainscoat, R. J.; Foley, R. J.; Jha, S. W.; Rest, A.; Scolnic, D.

    2016-03-01

    Seven bright transients have been discovered as part of the Pan-STARRS Survey for Transients (PSST). Information on all objects discovered by the Pan-STARRS Survey for Transients is available at http://star.pst.qub.ac.uk/ps1threepi/ (see Huber et al. ATel #7153).

  14. Bright Transients discovered by PSST

    NASA Astrophysics Data System (ADS)

    Smith, K. W.; Wright, D.; Smartt, S. J.; Young, D. R.; Huber, M.; Chambers, K. C.; Flewelling, H.; Willman, M.; Primak, N.; Schultz, A.; Gibson, B.; Magnier, E.; Waters, C.; Tonry, J.; Wainscoat, R. J.; Foley, R. J.; Jha, S. W.; Rest, A.; Scolnic, D.

    2016-08-01

    Six bright transients have been discovered as part of the Pan-STARRS Survey for Transients (PSST). Information on all objects discovered by the Pan-STARRS Survey for Transients is available at http://star.pst.qub.ac.uk/ps1threepi/ (see Huber et al. ATel #7153).

  15. Two Transients discovered by PSST

    NASA Astrophysics Data System (ADS)

    Smith, K. W.; Wright, D.; Smartt, S. J.; Young, D. R.; Huber, M.; Chambers, K. C.; Flewelling, H.; Willman, M.; Primak, N.; Schultz, A.; Gibson, B.; Magnier, E.; Waters, C.; Tonry, J.; Wainscoat, R. J.; Foley, R. J.; Jha, S. W.; Rest, A.; Scolnic, D.

    2016-08-01

    Two transients have been discovered as part of the Pan-STARRS Survey for Transients (PSST). Information on all objects discovered by the Pan-STARRS Survey for Transients is available at http://star.pst.qub.ac.uk/ps1threepi/ (see Huber et al. ATel #7153).

  16. Advanced PFBC transient analysis

    SciTech Connect

    White, J.S.; Bonk, D.L.

    1997-05-01

    Transient modeling and analysis of advanced Pressurized Fluidized Bed Combustion (PFBC) systems is a research area that is currently under investigation by the US Department of Energy`s Federal Energy Technology Center (FETC). The object of the effort is to identify key operating parameters that affect plant performance and then quantify the basic response of major sub-systems to changes in operating conditions. PC-TRAX{trademark}, a commercially available dynamic software program, was chosen and applied in this modeling and analysis effort. This paper describes the development of a series of TRAX-based transient models of advanced PFBC power plants. These power plants burn coal or other suitable fuel in a PFBC, and the high temperature flue gas supports low-Btu fuel gas or natural gas combustion in a gas turbine topping combustor. When it is utilized, the low-Btu fuel gas is produced in a bubbling bed carbonizer. High temperature, high pressure combustion products exiting the topping combustor are expanded in a modified gas turbine to generate electrical power. Waste heat from the system is used to raise and superheat steam for a reheat steam turbine bottoming cycle that generates additional electrical power. Basic control/instrumentation models were developed and modeled in PC-TRAX and used to investigate off-design plant performance. System performance for various transient conditions and control philosophies was studied.

  17. ON DETECTING TRANSIENT PHENOMENA

    SciTech Connect

    Belanger, G.

    2013-08-10

    Transient phenomena are interesting and potentially highly revealing of details about the processes under observation and study that could otherwise go unnoticed. It is therefore important to maximize the sensitivity of the method used to identify such events. In this article, we present a general procedure based on the use of the likelihood function for identifying transients which is particularly suited for real-time applications because it requires no grouping or pre-processing of the data. The method makes use of all the information that is available in the data throughout the statistical decision-making process, and is suitable for a wide range of applications. Here we consider those most common in astrophysics, which involve searching for transient sources, events or features in images, time series, energy spectra, and power spectra, and demonstrate the use of the method in the case of a weak X-ray flare in a time series and a short-lived quasi-periodic oscillation in a power spectrum. We derive a fit statistic that is ideal for fitting arbitrarily shaped models to a power density distribution, which is of general interest in all applications involving periodogram analysis.

  18. Satellitenbewegung, band III: Natiirliche und gesteuerte bewegung.

    NASA Astrophysics Data System (ADS)

    Jochim, E. F.

    2014-12-01

    Im dritten Band der Satellitenbewegung werden in fortlaufender Nummerierung einige für Untersuchungen der Bewegung der künstlichen Satelliten wichtige Grundlagen der Astrodynamik mit ausführlichen mathematischen Formelsystemen behandelt. Dazu zählen die unterschiedlichen Aspekte der Bewegung der natürlichen Himmelskörper, die Steuerung und Kontrolle von künstlichen Objekten, und insbesondere die für eine Satellitenbahnanalyse wichtigen physikalischen Beeinflussungen einer Satellitenbewegung. Mathematisch entscheidend ist die Wahl geeigneter Bahnparameter, die ein bestimmtes Bewegungsproblem widerspruchsfrei und singularitätenfrei zu behandeln gestatten. Für die Behandlung routinemäßiger Aufgabenstellungen der Satellitenbewegung, in erster Linie einer präzisen Bahnbestimmung und Bahnverbesserung, kann auf eine Fülle von lehrbuchartigen Monographien verwiesen werden, so dass diese Problematik in der vorliegenden Arbeit nur angedeutet werden soll.

  19. Simulation und virtuelle Realität

    NASA Astrophysics Data System (ADS)

    von Estorff, Otto; Markiewicz, Marian; Özkan, Ali; Zaleski, Olgierd; Blumrich, Reinhard; Genuit, Klaus; Fiebig, André

    Mit Hilfe akustischer Berechnungen ist es möglich, aufwendige Messungen an Fahrzeugprototypen deutlich zu reduzieren. Dieses Kapitel gibt einen kurzen Überblick über die wichtigsten derzeit verfügbaren Methoden. Dabei wird zunächst auf Elementverfahren, wie die Finite-Elemente-Methode (FEM) und die Boundary-Elemente-Methode (BEM), näher eingegangen. Während diese vor allem im tieffrequenten Bereich eingesetzt werden, kommen bei höheren Frequenzen vermehrt Verfahren zum Einsatz, die auf Energieformulierungen beruhen. Exemplarisch wird hier die Funktionsweise und der Einsatz der Statistischen-Energie-Analyse (SEA) erläutert. Anhand von repräsentativen Beispielen werden die Einsatzmöglichkeiten und Grenzen der verschiedenen Verfahren aufgezeigt, wobei vor allem auch auf Vergleiche zwischen Rechnung und Messung eingegangen wird.

  20. Hochschule fur Film und Fernsehen (Babelsberg).

    ERIC Educational Resources Information Center

    Neumann, Roland

    1992-01-01

    Describes the Hochschule fur Film und Fernsehen, an institution of higher education for the study of film and television production in Babelsberg, Germany (formerly the German Democratic Republic). Discusses the major reorientations in the school caused by Germany's reunification. (SR)

  1. Kosmische Katastrophen und der Ursprung der Religion.

    NASA Astrophysics Data System (ADS)

    Hoyle, F.

    This book is a German translation, by V. Delavre, from the English original "The origin of the Universe and the origin of religion", published in 1993. Contents: E. Sens: Die unterbrochene Musikstunde. Einleitung zur deutschen Ausgabe. C. Ryskamp: Einführung. R. N. Anshen: Vorwort. F. Hoyle: Kosmische Katastrophen und der Ursprung der Religion - Die Folgen der Respektabilität; Eiszeiten und Kometen; Die allgemeine Situation in den Nacheiszeiten; Kometen und der Ursprung der Religionen; Der Übergang zu Mittelalter und Neuzeit. Diskussionsbeiträge: Ruth Nanda Anshen, Freeman Dyson, Paul Oscar Kristeller, John Archibald Wheeler, James Schwartz, Roger Shinn, Milton Gatch, Philip Solomon, Norman Newell. F. Hoyle: Schlußwort. A. Tollmann: Nachwort zur deutschen Ausgabe.

  2. Workshop on Radio Transients

    NASA Astrophysics Data System (ADS)

    Croft, Steve; Gaensler, Bryan

    2012-04-01

    abstract-type="normal">SummaryWe are entering a new era in the study of variable and transient radio sources. This workshop discussed the instruments and the strategies employed to study those sources, how they are identified and classified, how results from different surveys can be compared, and how radio observations tie in with those at other wavelengths. The emphasis was on learning what common ground there is between the plethora of on-going projects, how methods and code can be shared, and how best practices regarding survey strategy could be adopted. The workshop featured the four topics below. Each topic commenced with a fairly brief introductory talk, which then developed into discussion. By way of preparation, participants had been invited to upload and discuss one slide per topic to a wiki ahead of the workshop. 1. Telescopes, instrumentation and survey strategy. New radio facilities and on-going projects (including upgrades) are both studying the variability of the radio sky, and searching for transients. The discussion first centred on the status of those facilities, and on projects with a time-domain focus, both ongoing and planned, before turning to factors driving choices of instrumentation, such as phased array versus single pixel feeds, the field of view, spatial and time resolution, frequency and bandwidth, depth, area, and cadence of the surveys. 2. Detection, pipelines, and classification. The workshop debated (a) the factors that influence decisions to study variability in the (u,v) plane, in images, or in catalogues, (b) whether, and how much, pipeline code could potentially be shared between one project and another, and which software packages are best for different approaches, (c) how data are stored and later accessed, and (d) how transients and variables are defined and classified. 3. Statistics, interpretation, and synthesis. It then discussed how (i) the choice of facility and strategy and (ii) detection and classification schemes

  3. Thermal transient anemometer

    DOEpatents

    Bailey, James L.; Vresk, Josip

    1989-01-01

    A thermal transient anemometer having a thermocouple probe which is utilized to measure the change in temperature over a period of time to provide a measure of fluid flow velocity. The thermocouple probe is located in the fluid flow path and pulsed to heat or cool the probe. The cooling of the heated probe or the heating of the cooled probe from the fluid flow over a period of time is measured to determine the fluid flow velocity. The probe is desired to be locally heated near the tip to increase the efficiency of devices incorporating the probe.

  4. Thermal transient anemometer

    DOEpatents

    Bailey, J.L.; Vresk, J.

    1989-07-18

    A thermal transient anemometer is disclosed having a thermocouple probe which is utilized to measure the change in temperature over a period of time to provide a measure of fluid flow velocity. The thermocouple probe is located in the fluid flow path and pulsed to heat or cool the probe. The cooling of the heated probe or the heating of the cooled probe from the fluid flow over a period of time is measured to determine the fluid flow velocity. The probe is desired to be locally heated near the tip to increase the efficiency of devices incorporating the probe. 12 figs.

  5. Transient neonatal tyrosinaemia.

    PubMed

    Rice, D N; Houston, I B; Lyon, I C; Macarthur, B A; Mullins, P R; Veale, A M; Guthrie, R

    1989-01-01

    Children who had presented with transient neonatal tyrosinaemia (TNT) were compared with a group of unaffected controls at 7-9 years of age. A comprehensive psychometric assessment revealed significant differences between the groups in adaptive behaviour, psycholinguistic abilities, and speed of learning. In nearly all components of the tests used, higher levels of TNT were associated with lower levels of performance. This study demonstrates that TNT, a condition commonly regarded as benign in the short term, has long-term effects which may be detrimental to the child in school.

  6. Transient enthalpy probe development

    NASA Astrophysics Data System (ADS)

    Bennett, Brian K.

    A reliable diagnostic probe has been developed to measure the local enthalpy in high-pressure, arc heated test streams that simulate atmospheric reentry conditions. The probe employs the double sonic-throat technique and is designed for the sweep (transient) mode to survive the severe heating environment. Tests in the high-pressure arc heater facilities show that, under certain conditions, the enthalpy probe measurements are in good agreement with enthalpy profiles inferred from heat flux measurements using the theory of Fay and Riddell (1958).

  7. The Rapid Transient Surveyor

    NASA Astrophysics Data System (ADS)

    Baranec, Christoph; Tonry, John; Wright, Shelley; Tully, R. Brent; Lu, Jessica R.; Takamiya, Marianne Y.; Hunter, Lisa

    2016-01-01

    The next decade of astronomy will be dominated by large area surveys (see the detailed discussion in the Astro-2010 Decadal survey and NRC's recent OIR System Report). Ground-based optical transient surveys, e.g., LSST, ZTF and ATLAS and space-based exoplanet, supernova, and lensing surveys such as TESS and WFIRST will join the Gaia all-sky astrometric survey in producing a flood of data that will enable leaps in our understanding of the universe. There is a critical need for further characterization of these discoveries through high angular resolution images, deeper images, spectra, or observations at different cadences or periods than the main surveys. Such follow-up characterization must be well matched to the particular surveys, and requires sufficient additional observing resources and time to cover the extensive number of targets.We describe plans for the Rapid Transient Surveyor (RTS), a permanently mounted, rapid-response, high-cadence facility for follow-up characterization of transient objects on the U. of Hawai'i 2.2-m telescope on Maunakea. RTS will comprise an improved robotic laser adaptive optics system, based on the prototype Robo-AO system (formerly at the Palomar 1.5-m and now at the Kitt Peak 2.2-m telescope), with simultaneous visible and near-infrared imagers as well as a near-infrared integral field spectrograph (R~100, λ = 850 - 1830 nm, 0.15″ spaxels, 8.7″×6.0″ FoV). RTS will achieve an acuity of ~0.07″ in visible wavelengths and < 0.16″ in the near infrared leading to an increase of the infrared point-source sensitivity against the sky background by a factor of ~9, crucial for efficient near-infrared spectroscopy.RTS will allow us to map the dark matter distribution in the z < 0.1 local universe with ten times better accuracy and precision than previous experiments. ATLAS will discover several thousand SNIae per year, measuring SNIa peak brightness, and decline rates, while RTS will measure reddening by dust, confirm SN type and

  8. Characterizing Nanoscale Transient Communication.

    PubMed

    Chen, Yifan; Anwar, Putri Santi; Huang, Limin; Asvial, Muhamad

    2016-04-01

    We consider the novel paradigm of nanoscale transient communication (NTC), where certain components of the small-scale communication link are physically transient. As such, the transmitter and the receiver may change their properties over a prescribed lifespan due to their time-varying structures. The NTC systems may find important applications in the biomedical, environmental, and military fields, where system degradability allows for benign integration into life and environment. In this paper, we analyze the NTC systems from the channel-modeling and capacity-analysis perspectives and focus on the stochastically meaningful slow transience scenario, where the coherence time of degeneration Td is much longer than the coding delay Tc. We first develop novel and parsimonious models to characterize the NTC channels, where three types of physical layers are considered: electromagnetism-based terahertz (THz) communication, diffusion-based molecular communication (DMC), and nanobots-assisted touchable communication (TouchCom). We then revisit the classical performance measure of ϵ-outage channel capacity and take a fresh look at its formulations in the NTC context. Next, we present the notion of capacity degeneration profile (CDP), which describes the reduction of channel capacity with respect to the degeneration time. Finally, we provide numerical examples to demonstrate the features of CDP. To the best of our knowledge, the current work represents a first attempt to systematically evaluate the quality of nanoscale communication systems deteriorating with time.

  9. Transient congenital hypothyroidism

    PubMed Central

    Bhavani, Nisha

    2011-01-01

    Transient thyroid function abnormalities in the new born which revert back to normal after varying periods of time are mostly identified in the neonatal screening tests for thyroid and are becoming more common because of the survival of many more premature infants. It can be due to factors primarily affecting the thyroid-like iodine deficiency or excess, maternal thyroid-stimulating hormone receptor (TSHR) antibodies, maternal use of antithyroid drugs, DUOX 2 (dual oxidase 2) mutations, and prematurity or those that affect the pituitary-like untreated maternal hyperthyroidism, prematurity, and drugs. Most of these require only observation, whereas some, such as those due to maternal TSHR antibodies may last for upto three-to-six months and may necessitate treatment. Isolated hyperthyrotropinemia (normal Tetraiodothyronine (T4) and high Thyroid Stimulating hormone (TSH)) may persist as subclinical hypothyroidism in childhood. Transient hypothyroxinemia (low T4 and normal TSH) is very common in premature babies. The recognition of these conditions will obviate the risks associated with unnecessary thyroxine supplementation in childhood and parental concerns of a life long illness in their offspring. PMID:21966647

  10. Tycho Brahe - Instrumentenbauer und Meister der Beobachtungstechnik

    NASA Astrophysics Data System (ADS)

    Wolfschmidt, Gudrun

    Vor der Erfindung des Fernrohrs war der dänische Astronom Tycho Brahe (1546 - 1601) der bedeutendste beobachtende Astronom. Von seinem Observatorium Uraniborg auf der - damals dänischen - Insel Hven ist heute noch der Grundriß erkennbar, von Stjerneborg sind die Fundamente erhalten, die Kuppeln in den 1950er Jahren ergänzt. In der Astronomie-Ausstellung im Deutschen Museum gibt es ein Modell der Sternwarte Uraniborg und der zugehörigen Instrumente (Maßstab 1:10); das größere Modell wurde dem Technischen Museum in Malmö geschenkt. Die Instrumente, die er in den Observatorien Uraniborg und Stjerneborg benutzte, sind nicht erhalten. Aber es gibt gute Beschreibungen der Instrumente (Halbkreis, Quadranten, Sextanten, Armillarsphären, Triquetrum, Himmelsglobus) in seinem Buch Astronomiae instauratae mechanica (Wandsbek 1598). Eine Nachbildung des großen hölzernen Quadranten kann man im Runden Turm in Kopenhagen sehen. Zwei Sextanten, hergestellt für Tycho um 1600 von Jost Bürgi und Erasmus Habermel, gibt es noch im Nationalmuseum für Technik in Prag. Ähnlichkeiten von Tychos Instrumenten mit Groß-Instrumenten aus dem islamischen Kulturkreis sind auffällig. Tycho Brahes Meßgeräte markieren einen großen Fortschritt in der Entwicklung astronomischer Instrumente und Meßtechniken und bilden die Grundlage für den weiteren Fortschritt der Positionsastronomie und der damit verbundenen Tabellenwerke. Die Nachwirkungen sind bis ins 17. und 18. Jahrhundert nachweisbar.

  11. The joy of transient chaos

    SciTech Connect

    Tél, Tamás

    2015-09-15

    We intend to show that transient chaos is a very appealing, but still not widely appreciated, subfield of nonlinear dynamics. Besides flashing its basic properties and giving a brief overview of the many applications, a few recent transient-chaos-related subjects are introduced in some detail. These include the dynamics of decision making, dispersion, and sedimentation of volcanic ash, doubly transient chaos of undriven autonomous mechanical systems, and a dynamical systems approach to energy absorption or explosion.

  12. The joy of transient chaos

    NASA Astrophysics Data System (ADS)

    Tél, Tamás

    2015-09-01

    We intend to show that transient chaos is a very appealing, but still not widely appreciated, subfield of nonlinear dynamics. Besides flashing its basic properties and giving a brief overview of the many applications, a few recent transient-chaos-related subjects are introduced in some detail. These include the dynamics of decision making, dispersion, and sedimentation of volcanic ash, doubly transient chaos of undriven autonomous mechanical systems, and a dynamical systems approach to energy absorption or explosion.

  13. The Zwicky Transient Facility

    NASA Astrophysics Data System (ADS)

    Kulkarni, Shrinivas R.

    2016-01-01

    The Zwicky Transient Facility (ZTF) has been designed with a singular focus: a systematic exploration of the night sky at a magnitude level well suited for spectral classification and follow up with the existing class of 4-m to 10-m class telescopes. ZTF is the successor to the Palomar Transient Factory (PTF). The discovery engine for ZTF is a 47 square degree camera (realized through 16 e2V monolithic CCDs) that fills the entire focal plane of the 48-inch Oschin telescope of the Palomar Observatory. Single 30-s epoch sensitivity is about 20.5 in g and R bands. The Infarared Processing & Analysis Center (IPAC) is the data center for ZTF. ZTF is a public-private partnership with equal contributions from a consortium of world-wide partners and an NSF MSIP grant. Forty percent of ZTF time is set aside for two major community surveys: a 3-day cadence survey of high latitudes (to mimic LSST) and a time domain survey of the entire Northern Galactic plane. We expect first light in February 2017 and begin a 3-year survey starting summer of 2017. The first year will be spent on building up deep reference images of the sky (a must for transient surveys). During the second year IPAC will deliver near archival quality photometric products within 12 hours of observations. By comparison to reference images photometric alerts will be sent out. Year 3 will see the near real-time release of image differencing products. A Community Science Advisory Committee (CSAC), chaired by S. Ridgway (NOAO), has been set up to both advise the PI and to ensure that the US community's interests are well served. Astronomers interested in getting a head start on ZTF may wish to peruse the data releases from PTF. Young people (or young at heart) may wish to attend the annual summer school on PTF/ZTF (August, Caltech campus). The Principal Investigator (PI) for the project is S. Kulkarni and the Project Scientist is Eric Bellm.For further details please consult http://www.ptf.caltech.edu/ztf

  14. Transient complex peroxisomal interactions

    PubMed Central

    Bonekamp, Nina A.; Schrader, Michael

    2012-01-01

    Mitochondria and peroxisomes are ubiquitous subcellular organelles that fulfill essential metabolic functions, rendering them indispensable for human development and health. Both are highly dynamic organelles that can undergo remarkable changes in morphology and number to accomplish cellular needs. While mitochondrial dynamics are also regulated by frequent fusion events, the fusion of mature peroxisomes in mammalian cells remained a matter of debate. In our recent study, we clarified systematically that there is no complete fusion of mature peroxisomes analogous to mitochondria. Moreover, in contrast to key division components such as DLP1, Fis1 or Mff, mitochondrial fusion proteins were not localized to peroxisomes. However, we discovered and characterized novel transient, complex interactions between individual peroxisomes which may contribute to the homogenization of the often heterogeneous peroxisomal compartment, e.g., by distribution of metabolites, signals or other “molecular information” via interperoxisomal contact sites. PMID:23336019

  15. Perturbations for transient acceleration

    SciTech Connect

    Vargas, Cristofher Zuñiga; Zimdahl, Winfried; Hipólito-Ricaldi, Wiliam S. E-mail: hipolito@ceunes.ufes.br

    2012-04-01

    According to the standard ΛCDM model, the accelerated expansion of the Universe will go on forever. Motivated by recent observational results, we explore the possibility of a finite phase of acceleration which asymptotically approaches another period of decelerated expansion. Extending an earlier study on a corresponding homogeneous and isotropic dynamics, in which interactions between dark matter and dark energy are crucial, the present paper also investigates the dynamics of the matter perturbations both on the Newtonian and General Relativistic (GR) levels and quantifies the potential relevance of perturbations of the dark-energy component. In the background, the model is tested against the Supernova type Ia (SNIa) data of the Constitution set and on the perturbative level against growth rate data, among them those of the WiggleZ survey, and the data of the 2dFGRS project. Our results indicate that a transient phase of accelerated expansion is not excluded by current observations.

  16. Transient infrared transmission spectroscopy

    SciTech Connect

    Jones, R.W.; McClelland, J.F. )

    1990-10-15

    Transient infrared transmission spectroscopy is a new method that can acquire analytically useful transmission spectra from moving, optically thick solids. No sample preparation is required. The spectra are of sufficient quality for accurate quantitative compositional analysis. The method works by the creation of a thin, short-lived, chilled layer at the sample surface. Blackbody-like thermal emission from the bulk of the sample is selectively absorbed as it passes through the chilled layer, so the transmission spectrum of the layer is superimposed on the observed thermal emission. Spectra of polycarbonate, beeswax, and copolymers of methyl and butyl methacrylate are presented. Compositional analysis of the methacrylate copolymers with a standard error or prediction of only 0.87 mol % is demonstrated.

  17. Transient infrared transmission spectroscopy.

    PubMed

    Jones, R W; McClelland, J F

    1990-10-15

    Transient infrared transmission spectroscopy is a new method that can acquire analytically useful transmission spectra from moving, optically thick solids. No sample preparation is required. The spectra are of sufficient quality for accurate quantitative compositional analysis. The method works by the creation of a thin, short-lived, chilled layer at the sample surface. Blackbody-like thermal emission from the bulk of the sample is selectively absorbed as it passes through the chilled layer, so the transmission spectrum of the layer is superimposed on the observed thermal emission. Spectra of polycarbonate, beeswax, and copolymers of methyl and butyl methacrylate are presented. Compositional analysis of the methacrylate copolymers with a standard error of prediction of only 0.87 mol % is demonstrated.

  18. Leitbilder und Handlungsstrategien für die Raumentwicklung in Deutschland. Entwicklungs-, Umsetzungs- und Fortschreibungsprozess der Bund-Länder-Strategie für Städte und Regionen

    NASA Astrophysics Data System (ADS)

    Issaoui, Mariam; Sinz, Manfred

    2010-09-01

    Die Ministerkonferenz für Raumordnung stellte im Mai 2010 fest, dass sich die „Leitbilder und Handlungsstrategien für die Raumentwicklung in Deutschland“ (2006) bewährt haben und bei der Gestaltung der räumlichen Entwicklung umgesetzt werden. Um die Leitbilder den sich verändernden wirtschaftlichen, sozialen und naturräumlichen Rahmenbedingungen anzupassen und die Erkenntnisse aus dem bisherigen Diskussions- und Umsetzungsprozess in Politik und Praxis einzubeziehen, sind sie zu ergänzen und weiterzuentwickeln. Im Mittelpunkt der Fortschreibung werden die Themen „Partnerschaften und Strategien für Stadtregionen und ländliche Räume“, „Mobilität und Logistik“ sowie „Klimaschutz und Energieversorgung“ stehen.

  19. Die neue Kosmologie. Von Dunkelmaterie, GUTs und Superhaufen.

    NASA Astrophysics Data System (ADS)

    Cornell, J.

    This book is a German translation, by M. Röser, of the American original "Bubbles, voids, and bumps in time: the new cosmology", published 1989 (see 49.003.045). Contents: 1. Die Entdeckung des Weltalls: Eine Einleitung (A. P. Lightman). 2. Die Vermessung des Weltalls: Rotverschiebungen und Standardkerzen (R. P. Kirshner). 3. Die Kartierung des Weltalls: Scheiben und Blasen (M. J. Geller). 4. Die Bestimmung der Masse im Weltall: Dunkelmaterie und fehlende Masse (V. C. Rubin). 5. Der Beginn des Weltalls: Urknall und kosmische Inflation (A. H. Guth). 6. Die Ausweitung des Weltalls: Das Weltraumteleskop und Perspektiven für die nächsten 20 Jahre (J. E. Gunn).

  20. Summer 1993 Transient Student Report.

    ERIC Educational Resources Information Center

    Kent State Univ., Warren, OH. Office of Institutional Research.

    A study was conducted by the Trumbull Campus (TC) of Kent State University, in Ohio, to determine the motivations, objectives, and level of satisfaction of transient students, or students pursuing a degree at another institution but enrolled in courses at TC. Surveys were mailed to 50 transient students enrolled in summer 1993, with completed…

  1. Zwischen Web 2.0, virtuellen Welten und Game-based Learning - Einsatzszenarien und Prototypen im Hochschulumfeld

    NASA Astrophysics Data System (ADS)

    Pongratz, Hans

    Web 2.0, virtuelle Welten und Game-based Learning werden als Allheilmittel moderner Wissensvermittlung an Hochschulen genannt. Dieser Artikel beschreibt nach einer Einführung in die Thematik Einsatzszenarien und Prototypen im Hochschulumfeld anhand ausgewählter Web 2.0-Dienste, der virtuellen Welt Second Life, eines an der TUM entwickelten Frameworks für Gamebased Learning Applikationen und eines Lernspiels. Diese werden anhand von konkreten Lehr- und Lernszenarien vorgestellt und anhand der bisherigen Erfahrungen in diesem Bereich kritisch beleuchtet.

  2. Wilhelm Julius Foerster und die "Vereinigung von Freunden der Astronomie und kosmischen Physik" (1891 bis 1914).

    NASA Astrophysics Data System (ADS)

    Tiemann, K.-H.

    Am 19. Mai 1891 wurde ins Leben gerufen die "Vereinigung von Freunden der Astronomie und der kosmischen Physik (nachfolg.: V.A.P.) - eine der beiden institutionellen Vorläufer der sich 1953 konstituierenden "Vereinigung der Sternfreunde".

  3. Transient catalytic combustor model

    NASA Technical Reports Server (NTRS)

    Tien, J. S.

    1981-01-01

    A quasi-steady gas phase and thermally thin substrate model is used to analyze the transient behavior of catalytic monolith combustors in fuel lean operation. The combustor response delay is due to the substrate thermal inertia. Fast response is favored by thin substrate, short catalytic bed length, high combustor inlet and final temperatures, and small gas channel diameters. The calculated gas and substrate temperature time history at different axial positions provides an understanding of how the catalytic combustor responds to an upstream condition change. The computed results also suggest that the gas residence times in the catalytic bed in the after bed space are correlatable with the nondimensional combustor response time. The model also performs steady state combustion calculations; and the computed steady state emission characteristics show agreement with available experimental data in the range of parameters covered. A catalytic combustor design for automotive gas turbine engine which has reasonably fast response ( 1 second) and can satisfy the emission goals in an acceptable total combustor length is possible.

  4. Gravitation und Kosmologie. Eine Einführung in die allgemeine Relativitätstheorie.

    NASA Astrophysics Data System (ADS)

    Sexl, R. U.; Urbantke, H. K.

    Contents: 1. Physikalische Grundlagen. 2. Riemannsche Geometrie. 3. Gravitationstheorie. 4. Experimentelle Tests. 5. Kosmologie. 6. Gravitationswellen. 7. Neue differentialgeometrische Methoden. 8. Sternbau und Gravitationskollaps. 9. Felder im Riemannschen Raum. 10. Gravitation und Feldtheorie. 11. Gravitation und Eichtheorie.

  5. Transient upsets in microprocessor controllers

    NASA Technical Reports Server (NTRS)

    Glaser, R. E.; Masson, G. M.

    1981-01-01

    The modeling and analysis of transient faults in microprocessor based controllers are discussed. Such controllers typically consist of a microprocessor, read only memory storing and application program, random access memory for data storage, and input/output devices for external communications. The effects of transient faults on the performance of the controller are reviewed. An instruction level perspective of performance is taken which is the basis of a useful high level program state description of the microprocessor controller. A transition matrix is defined which determines the controller's response to transient fault arrivals.

  6. Transient overvoltages on cable sheaths

    NASA Astrophysics Data System (ADS)

    Dabringhaus, H. G.

    1983-08-01

    Transient overvoltage on the sheaths of high voltage cables with single point sheath earthing or cross bonding of the cable sheaths involve danger for the cable and the joints. The investigations of transient overvoltages in the case of a switching operation on a 110 kV single core oil filled cable with single sided sheath earthing are reported. A comparison between measured transient voltage variations and those calculated with the help of a traveling wave analyzer program shows very good agreement. The investigations showed that with single point sheath earthing, the unearthed sheath end ought to be protected against overvoltages.

  7. Transient characteristics of rocket turbopumps

    NASA Astrophysics Data System (ADS)

    Shimura, Takashi; Watanabe, Mitsuo

    Transient characteristics of high-speed, high-pressure cryogenic turbopumps for rocket engines were examined experimentally by starting and stopping several rocket turbopumps rapidly by gas turbine drive. Aspects of transient characteristics studied were instantaneous pump head coefficient and pump efficiency, cavitation growth in the inducer during rapid acceleration, effects of the starting mode related to the propulsion system mission, and transient behavior of a self-balancing type axial thrust balancing system. Based on the test results, the feasibility of definite starting modes for the LE-5 turbopump was confirmed and the self-balancing type axial thrust balancing system for the LE-7 LOX turbopump was completed.

  8. Transient nucleation in condensed systems

    NASA Technical Reports Server (NTRS)

    Kelton, K. F.; Greer, A. L.; Thompson, C. V.

    1983-01-01

    Using classical nucleation theory we consider transient nucleation occurring in a one-component, condensed system under isothermal conditions. We obtain an exact closed-form expression for the time dependent cluster populations. In addition, a more versatile approach is developed: a numerical simulation technique which models directly the reactions by which clusters are produced. This simulation demonstrates the evolution of cluster populations and nucleation rate in the transient regime. Results from the simulation are verified by comparison with exact analytical solutions for the steady state. Experimental methods for measuring transient nucleation are assessed, and it is demonstrated that the observed behavior depends on the method used. The effect of preexisting cluster distributions is studied. Previous analytical and numerical treatments of transient nucleation are compared to the solutions obtained from the simulation. The simple expressions of Kashchiev are shown to give good descriptions of the nucleation behavior.

  9. Differential Diagnosis of Transient Amnesia

    PubMed Central

    Croft, P. B.; Heathfield, K. W. G.; Swash, M.

    1973-01-01

    In a group of 39 consecutive patients attending neurological clinics with transient amnesia patients with transient global amnesia formed the largest group; others suffered from epilepsy, migraine, temporal lobe encephalitis, or psychogenic fugues. In most cases the clinical features suggested the aetiology, but an electroencephalogram recorded as soon after the attack as possible may help in distinguishing amnesia due to temporal lobe epilepsy. PMID:4758521

  10. Transient Tsunamis in Lakes

    NASA Astrophysics Data System (ADS)

    Couston, L.; Mei, C.; Alam, M.

    2013-12-01

    A large number of lakes are surrounded by steep and unstable mountains with slopes prone to failure. As a result, landslides are likely to occur and impact water sitting in closed reservoirs. These rare geological phenomena pose serious threats to dam reservoirs and nearshore facilities because they can generate unexpectedly large tsunami waves. In fact, the tallest wave experienced by contemporary humans occurred because of a landslide in the narrow bay of Lituya in 1958, and five years later, a deadly landslide tsunami overtopped Lake Vajont's dam, flooding and damaging villages along the lakefront and in the Piave valley. If unstable slopes and potential slides are detected ahead of time, inundation maps can be drawn to help people know the risks, and mitigate the destructive power of the ensuing waves. These maps give the maximum wave runup height along the lake's vertical and sloping boundaries, and can be obtained by numerical simulations. Keeping track of the moving shorelines along beaches is challenging in classical Eulerian formulations because the horizontal extent of the fluid domain can change over time. As a result, assuming a solid slide and nonbreaking waves, here we develop a nonlinear shallow-water model equation in the Lagrangian framework to address the problem of transient landslide-tsunamis. In this manner, the shorelines' three-dimensional motion is part of the solution. The model equation is hyperbolic and can be solved numerically by finite differences. Here, a 4th order Runge-Kutta method and a compact finite-difference scheme are implemented to integrate in time and spatially discretize the forced shallow-water equation in Lagrangian coordinates. The formulation is applied to different lake and slide geometries to better understand the effects of the lake's finite lengths and slide's forcing mechanism on the generated wavefield. Specifically, for a slide moving down a plane beach, we show that edge-waves trapped by the shoreline and free

  11. Detecting aseismic transients using seismicity

    NASA Astrophysics Data System (ADS)

    Reverso, T.; Marsan, D.; Helmstetter, A.

    2013-12-01

    Aseismic deformation transients occur in different tectonic context. In subduction zones, aseismic slip events are of paramount importance for understanding earthquake hazard, and for estimating the potential for future mega-thrust events. Aseismic slip is however difficult to detect except for the largest cases using GPS data. Here, we propose a systematic detection of aseismic deformation transients based on seismicity data alone. We search for transient increases in background seismicity rate, that would indicate the presence of an aseismic event. To that purpose, we make use of an ETAS model in space and time, to distinguish earthquakes due to background processes from aftershocks. We optimize the model parameters, and test the sensitivity of the results with changes in parameters. Given the 'best' model, we measure the statistical significance of the departure of the local (in time and space) background rate with the 'normal' background rate. Significant departure then indicates the need to temporary increase the background rate in order to explain the observed earthquake occurrences. We thus can single out such episodes of aseismic transients, and characterize their duration and spatial extent. Applying this method to the Aleutian subduction zone reveals several instances of aseismic deformation transients, at various spatial and temporal scales. We further investigate how these transients are organized along the subduction interface, and in time.

  12. Herstellung von Chitosan und einige Anwendungen

    NASA Astrophysics Data System (ADS)

    Struszczyk, Marcin Henryk

    2001-05-01

    1. Die Deacetylierung von crabshell - Chitosan führte gleichzeitig zu einem drastischen Abfall der mittleren viscosimetrischen Molmasse ( Mv), insbesondere wenn die Temperatur und die Konzentration an NaOH erhöht werden. Diese Parameter beeinflussten jedoch nicht den Grad der Deacetylierung (DD). Wichtig ist jedoch die Quelle des Ausgangsmaterials: Chitin aus Pandalus borealis ist ein guter Rohstoff für die Herstellung von Chitosan mit niedrigem DD und gleichzeitig hoher mittlerer Mv, während Krill-Chitin (Euphausia superba) ein gutes Ausgangsmaterial zur Herstellung von Chitosan mit hohem DD und niedrigem Mv ist. Chitosan, das aus Insekten (Calliphora erythrocephala), unter milden Bedingungen (Temperatur: 100°C, NaOH-Konzentration: 40 %, Zeit: 1-2h ) hergestellt wurde, hatte die gleichen Eigenschaften hinsichtlich DD und Mv wie das aus Krill hergestellte Chitosan. Der Bedarf an Zeit, Energie und NaOH ist für die Herstellung von Insekten-Chitosan geringer als für crabshell-Chitosan vergleichbare Resultaten für DD und Mv. 2. Chitosan wurde durch den Schimmelpilz Aspergillus fumigatus zu Chitooligomeren fermentiert. Die Ausbeute beträgt 25%. Die Chitooligomere wurden mit Hilfe von HPLC und MALDI-TOF-Massenspektrmetrie identifiziert. Die Fermentationsmischung fördert die Immunität von Pflanzen gegen Bakterien und Virusinfektion. Die Zunahme der Immunität schwankt jedoch je nach System Pflanze-Pathogen. Die Fermentation von Chitosan durch Aspergillus fumigatus könnte eine schnelle und billige Methode zur Herstellung von Chitooligomeren mit guter Reinheit und Ausbeute sein. Eine partiell aufgereinigte Fermentationsmischung dieser Art könnte in der Landwirtschaft als Pathogeninhibitor genutzt werden. Durch kontrollierte Fermentation, die Chitooligomere in definierter Zusammensetzung (d.h. definierter Verteilung des Depolymerisationsgrades) liefert, könnte man zu Mischungen kommen, die für die jeweilige Anwendung eine optimale Bioaktivität besitzen. 3

  13. The Transient Radio Sky

    NASA Astrophysics Data System (ADS)

    Keane, E. F.

    2010-11-01

    The high time-resolution radio sky represents unexplored astronomical territory where the discovery potential is high. In this thesis I have studied the transient radio sky, focusing on millisecond scales. As such, this work is concerned primarily with neutron stars, the mostpopulous member of the radio transient parameter space. In particular, I have studied the well known radio pulsars and the recently identified group of neutron stars which show erratic radio emission, known as RRATs, which show radio bursts every few minutes to every few hours. When RRATs burst onto the scene in 2006, it was thought that they represented a previously unknown, distinct class of sporadically emitting sources. The difficulty in their identification implies a large underlying population, perhaps larger than the radio pulsars. The first question investigated in this thesis was whether the large projected population of RRATs posed a problem, i.e. could the observed supernova rate account for so many sources. In addition to pulsars and RRATs, the various other known neutron star manifestations were considered, leading to the conclusion that distinct populations would result in a `birthrate problem'. Evolution between the classes could solve this problem -- the RRATs are not a distinct population ofneutron stars.Alternatively, perhaps the large projected population of RRATs is an overestimate. To obtain an improved estimate, the best approach is to find more sources. The Parkes Multi-beam Pulsar Survey, wherein the RRATs were initially identified, offered an opportunity to do just this. Abouthalf of the RRATs showing bursts during the survey were thought to have been missed, due to the deleterious effects of impulsive terrestrial interference signals. To remove these unwanted signals, so that we could identify the previously shrouded RRATs, we developed newinterference mitigation software and processing techniques. Having done this, the survey was completely re-processed, resulting in

  14. Bemerkungen zur Relativitätstheorie und zu den Quanten

    NASA Astrophysics Data System (ADS)

    Bergmann, Peter G.

    Die theoretischen und experimentellen Grundlagen von Gravitations- und Quantenphysik, die Beziehung beider Theorien und die Bedeutung wesentlicher Begriffe, wie Observable, werden diskutiert.Translated AbstractRemarks on Relativity and on Quantum TheoryThe theoretical and experimental foundations of gravitation and quantum physics are discussed as well as the relation of these two theories and the role of basic notions like observables.

  15. Vom Urknall zum Zerfall. Die Welt zwischen Anfang und Ende.

    NASA Astrophysics Data System (ADS)

    Fritzsch, H.

    Contents: Der Tanz mit dem Ozean. Galaktische Landkarte. Das Maß der Dinge. Der würfelnde Gott der Quantenphysik. Geheimnisvolle Felder. Materie und Antimaterie. Quarks - Urstoff unserer Welt. Zerfallende Protonen und die Einheit der Physik. Der Zauberofen. Das überschaubare Universum. Das explodierende Universum. Nachhall der Schöpfung. Der achtfache Weg der kosmischen Entwicklung. Das Ende der Welt. Einheit in der Vielfalt. Das geistige Universum. Gott und das absurde Universum.

  16. Das menschliche Gehör und Grundlagen der Psychoakustik

    NASA Astrophysics Data System (ADS)

    Genuit, Klaus; Sottek, Roland

    Das menschliche Gehör ist ein äußerst komplexes Empfangs- und Signalverarbeitungssystem. Es ist als Schallanalysator in Leistungsfähigkeit und Vielseitigkeit von technisch-analytischen Verfahren nach wie vor unerreicht. Die Signalverarbeitung läuft auf Grundlage komplexer Prozesse ab, die in ihrer Gesamtheit bislang nicht vollständig erfasst sind. Verschiedene Modelle zur gehörgerechten Zeit- und Frequenzanalyse ahmen jene komplexen Prozesse und Verarbeitungsmechanismen nach, die im menschlichen Gehör vollzogen werden.

  17. Ökologische Grundlagen und limitierende Faktoren der Renaturierung

    NASA Astrophysics Data System (ADS)

    Rosenthal, Gert; Eichberg, Carsten

    In den dicht besiedelten und agrarisch besonders intensiv genutzten Regionen Mittel- und Westeuropas ist seit Ende des Zweiten Weltkrieges ein fortschreitender Verlust an naturnahen ökosystemen mit hoher biologischer Vielfalt zu verzeichnen. Spätestens seit den 1970er-Jahren ist daher die Neuschaffung und Wiederherstellung gefährdeter Lebensräume und Biozönosen zunehmend in den Mittelpunkt von Naturschutzmaßnahmen gerückt (Bakker 1989, Muller et al. 1998, Bakker und Berendse 1999). Aufgrund fehlender wissenschaftlicher Grundlagen und praktischer Erfahrungen wurden Renaturierungsmaßnahmen anfangs fast durchweg nach dem trial and error-Prinzip durchgeführt. Im Vordergrund standen dabei zunächst die Wiederherstellung adäquater abiotischer Standortbedingungen sowie die Reorganisation traditioneller Nutzungsmanagements. Bei Ersterem ging es neben der Wiedervernässung entwässerter Feuchtgebiete (Pfadenhauer und Grootjans 1999) vor allem darum, Eutrophierungseffekte zu beseitigen und die Produktivität des Standortes auf das Niveau der Zielgemeinschaft zurückzuführen (Gough und Marrs 1990, Oomes et al. 1996, Snow et al. 1997, Tallowin et al. 1998).

  18. Supraleitung und Interkontinentalraketen „On-line computing“ zwischen Militär, Industrie und Wissenschaft

    NASA Astrophysics Data System (ADS)

    Knolle, Johannes; Joas, Christian

    Der zweite Weltkrieg und der Kalte Krieg veränderten nicht nur das Verhältnis zwischen Militär, Industrie und Wissenschaft, sondern auch die wissenschaftliche Praxis von Physikern und anderen Wissenschaftlern. In den 1950er Jahren stellte die Entwicklung von Interkontinentalraketen die Auftragnehmer des Militärs in der Industrie vor komplexe Fragestellungen, zu deren Lösung sie auf die Expertise von Wissenschaftlern angewiesen waren. Industrieunternehmen gründeten eigene Forschungseinheiten zur Lösung technischer und wissenschaftlicher Probleme.

  19. Darwin, Engels und die Rolle der Arbeit in der biologischen und kulturellen Evolution des Menschen

    NASA Astrophysics Data System (ADS)

    Reichholf, Josef H.

    Im Jahre 1876, 5 Jahre nach Erscheinen von Darwins Buch über die Evolution des Menschen und die sexuelle Selektion (Darwin 1871), veröffentlichte Friedrich Engels den berühmt gewordenen Essay "Anteil der Arbeit an der Menschwerdung des Affen“ (Engels 1876). Die Kernfrage darin lautet in Kurzform: Warum hat der Mensch eigentlich ein Bedürfnis nach Arbeit? Engels Antwort wird nachfolgend näher betrachtet und vom gegenwärtigen Kenntnisstand aus beurteilt. Wie sich zeigen wird, beantworten seine Überlegungen die Frage nicht wirklich. Sie ist weiterhin offen. Es können lediglich einige zusätzliche Anhaltspunkte zur Diskussion gestellt werden. Angesichts des drängenden Problems millionenfacher Arbeitslosigkeit und der Forderungen nach einem "Grundrecht auf Arbeit“ kommt den Überlegungen zum möglichen Ursprung des Bedürfnisses nach Arbeit mehr als nur akademisches Interesse zu.

  20. Transient Faults in Computer Systems

    NASA Technical Reports Server (NTRS)

    Masson, Gerald M.

    1993-01-01

    A powerful technique particularly appropriate for the detection of errors caused by transient faults in computer systems was developed. The technique can be implemented in either software or hardware; the research conducted thus far primarily considered software implementations. The error detection technique developed has the distinct advantage of having provably complete coverage of all errors caused by transient faults that affect the output produced by the execution of a program. In other words, the technique does not have to be tuned to a particular error model to enhance error coverage. Also, the correctness of the technique can be formally verified. The technique uses time and software redundancy. The foundation for an effective, low-overhead, software-based certification trail approach to real-time error detection resulting from transient fault phenomena was developed.

  1. Transient voltage oscillations in coils

    SciTech Connect

    Chowdhuri, P.

    1985-01-01

    Magnet coils may be excited into internal voltage oscillations by transient voltages. Such oscillations may electrically stress the magnet's dielectric components to many times its normal stress. This may precipitate a dielectric failure, and the attendant prolonged loss of service and costly repair work. Therefore, it is important to know the natural frequencies of oscillations of a magnet during the design stage, and to determine whether the expected switching transient voltages can excite the magnet into high-voltage internal oscillations. The series capacitance of a winding significantly affects its natural frequencies. However, the series capacitance is difficult to calculate, because it may comprise complex capacitance network, consisting of intra- and inter-coil turn-to-turn capacitances of the coil sections. A method of calculating the series capacitance of a winding is proposed. This method is rigorous but simple to execute. The time-varying transient voltages along the winding are also calculated.

  2. Cohabitation Duration and Transient Domesticity.

    PubMed

    Golub, Andrew; Reid, Megan; Strickler, Jennifer; Dunlap, Eloise

    2013-01-01

    Research finds that many impoverished urban Black adults engage in a pattern of partnering and family formation involving a succession of short cohabitations yielding children, a paradigm referred to as transient domesticity. Researchers have identified socioeconomic status, cultural adaptations, and urbanicity as explanations for aspects of this pattern. We used longitudinal data from the 2001 Survey of Income and Program Participation to analyze variation in cohabitation and marriage duration by race/ethnicity, income, and urban residence. Proportional hazards regression indicated that separation risk is greater among couples that are cohabiting, below 200% of the federal poverty line, and Black but is not greater among urban dwellers. This provides empirical demographic evidence to support the emerging theory of transient domesticity and suggests that both socioeconomic status and race explain this pattern. We discuss the implications of these findings for understanding transient domesticity and make recommendations for using the Survey of Income and Program Participation to further study this family formation paradigm.

  3. Haptische Modellierung und Deformation einer Kugelzelle

    NASA Astrophysics Data System (ADS)

    Schippritt, Darius; Wiemann, Martin; Lipinski, Hans-Gerd

    Haptische Simulationsmodelle dienen in der Medizin in erster Linie dem Training operativer Eingriffe. Sie basieren zumeist auf physikalischen Gewebemodellen, welche eine sehr genaue Simulation der biomechanischen Eigenschaften des betreffenden Gewebes erlauben, aber gleichzeitig sehr rechenintensiv und damit zeitaufwändig in der Ausführung sind. Die menschliche Wahrnehmung kann allerdings auch eine ungenaue haptische Modellierung psychooptisch ausgleichen. Daher kann es sinnvoll sein, haptische Simulationen auch mit nicht vollständig physikalisch definierten Deformationsmodellen durchzuführen. Am Beispiel der haptischer Simulation einer in-vitro Fertilisation wird gezeigt, dass durch die Anwendung eines geometrischen Deformationsmodells eine künstliche Befruchtung unter realistischen experimentellen Bedingungen in Echtzeit haptisch simuliert und damit trainiert werden kann.

  4. Biochips und ihr Einsatz in der Lebensmittelanalytik

    NASA Astrophysics Data System (ADS)

    Huber, Ingrid; Zeltz, Patric

    Mit der Verbreitung des Begriffes "Biochip“ in den biotechnologischen Medien wurde Ende der 1990er-Jahre zunächst der Eindruck erweckt, dass die Computerelektronik in die molekularbiologischen Anwendungen eingestiegen ist [18]. In nur wenigen Jahren hat sich die Biochiptechnologie zu einem Verfahren entwickelt, das aus der molekularbiologischen Grundlagenforschung nicht mehr wegzudenken ist und über eine Vielzahl von Einsatzbereichen verfügt. Die Biochiptechnologie ermöglicht die Miniaturisierung von DNA-, RNA- bzw. Proteinanalytik in hochparallelen Formaten. Dieser hohe Parallelisierungsgrad ist einer der wesentlichen Vorteile dieser Technik gegenüber klassischen molekularbiologischen Methoden. Sie wird heutzutage vor allem in der Genomforschung eingesetzt, für Genexpressionsstudien, zum Screening von single nucleotide polymorphisms (SNPs), in der pharmakogenetischen Forschung sowie in der Erforschung von Erbkrankheiten und in der Krebsforschung [1, 7, 19]. Neben vielen weiteren Bereichen finden Biochips auch spezielle Anwendungen in der Lebensmittelanalytik.

  5. Studies of Transient Meteor Activity

    NASA Technical Reports Server (NTRS)

    Jenniskens, Peter M. M.

    2002-01-01

    Meteoroids bombard Earth's atmosphere daily, but occasionally meteor rates increase to unusual high levels when Earth crosses the relatively fresh ejecta of comets. These transient events in meteor activity provide clues about the whereabouts of Earth-threatening long-period comets, the mechanisms of large-grain dust ejection from comets, and the particle composition and size distribution of the cometary ejecta. Observations of these transient events provide important insight in natural processes that determine the large grain dust environment of comets, in natural phenomena that were prevalent during the time of the origin of life, and in processes that determine the hazard of civilizations to large impacts and of man-made satellites to the periodic blizzard of small meteoroids. In this proposal, three tasks form a coherent program aimed at elucidating various aspects of meteor outbursts, with special reference to planetary astronomy and astrobiology. Task 1 was a ground-based effort to observe periods of transient meteor activity. This includes: (1) stereoscopic imaging of meteors during transient meteor events for measurements of particle size distribution, meteoroid orbital dispersions and fluxes; and (2) technical support for Global-MS-Net, a network of amateur-operated automatic counting stations for meteor reflections from commercial VHF radio and TV broadcasting stations, keeping a 24h vigil on the level of meteor activity for the detection of new meteor streams. Task 2 consisted of ground-based and satellite born spectroscopic observations of meteors and meteor trains during transient meteor events for measurements of elemental composition, the presence of organic matter in the meteoroids, and products generated by the interaction of the meteoroid with the atmosphere. Task 3 was an airborne effort to explore the 2000 Leonid meteor outbursts, which are anticipated to be the most significant of transient meteor activity events in the remainder of the

  6. Transient classification and novae ejecta

    NASA Astrophysics Data System (ADS)

    Williams, Robert

    2016-07-01

    A third parameter, in addition to luminosity and rate of brightness decline, derived from the spectra of transients is suggested as a means of more accurately classifying objects in outburst. Principal component analysis of the spectra of transients is suggested as the best way to determine the third parameter. A model is suggested for novae ejecta that is based on the ballistic ejection of an ensemble of clouds having a wide range of sizes. Short term brightness fluctuations of novae, the formation of dust, and the production of X-ray emission follow naturally from such a picture of the evolving clouds.

  7. Modeling a Transient Catalytic Combustor

    NASA Technical Reports Server (NTRS)

    Tien, J. S.

    1985-01-01

    Transient model of monolith catalytic combustor presented in report done under NASA/DOE contract. Model assumes quasi-steady gas phase and thermally "thin" solid. In gas-phase treatment, several quasi-global chemical reactions assumed capable of describing CO and unburnt hydrocarbon emissions in fuel-lean operations. In steady-state computation presented, influence of selected operating and design parameters on minimum combustor length studied. When fast transient responses required, both steady and unsteady studies made to achieve meaningful compromise in design.

  8. Elektronische Citizen Cards in Deutschland und Europa

    NASA Astrophysics Data System (ADS)

    Kowalski, Bernd

    Meine sehr geehrten Damen und Herren, der Bedarf an elektronischen Identitäten entsteht durch die wachsende Mobilität der Gesellschaft bei einem gleichzeitig steigenden Bedarf an Onlinepräsenz. Diese elektronischen Identitäten machen natürlich auch vor den staatlichen Ausweisen nicht halt, wie zum Beispiel dem Reisepass, aber auch dem Personalausweis und weiteren Ausweisdokumenten. Wobei es bei den staatlich herausgegebenen oder kontrollierten Ausweisen immer um zwei verschiedene Dinge geht: Einmal um die hoheitliche Funktion, wie zum Beispiel beim Reisepass. Hier geht es zum Beispiel darum, in einem Europa mit gefallenen Grenzen und bei freiem Reiseverkehr für alle Personen, die in diesem Raum wohnen, insbesondere auch im Schengener Raum, die Möglichkeit zu schaffen, auch künftig noch Personenkontrollen durchzuführen. Auch der Reiseverkehr über die europäischen Grenzen hinaus ist insofern ein Problem, da die Identitätenprüfung an den Grenzkontrollen immer schwieriger wird. Deswegen braucht man an dieser Stelle Möglichkeiten, um eine Personenüberprüfung durchzuführen, um feststellen zu können, dass diese Person auch zum Dokument gehört.

  9. Therapeutisches Management kutaner und genitaler Warzen.

    PubMed

    Ockenfels, Hans Michael

    2016-09-01

    Mindestens 10 % der Bevölkerung erkranken während ihres Lebens an einer Infektion mit humanen Papillomaviren (HPV), welche sich klinisch anhand der Ausbildung kutaner oder genitaler Warzen manifestiert. Obwohl Warzen ubiquitär sind, existieren keine definierten Behandlungen. Warzen zeigen, insbesondere in den ersten sechs Monaten, eine erhöhte Selbstheilungsrate. Dieser Umstand erschwert die Interpretation von Studien, da häufig Patienten mit Neuinfektionen zusammen mit Patienten mit Altinfektionen behandelt werden. Lokalisationen, Größe und Dicke der Warzen sind ebenfalls in den meisten Fällen nicht berücksichtigt. Ziel dieses Übersichtsartikels ist eine Analyse des vorliegenden Studienmaterials, unter der für den klinischen Alltag so wichtigen Berücksichtigung von Subtypen und Lokalisationen. Insbesondere die Abgrenzung zwischen frischen und chronisch-therapieresistenten Verrucae vulgares spiegelt sich in einem Therapiealgorithmus wider. Bei genitalen Warzen wird der Therapiealgorithmus deutlicher durch das Ausmaß der infizierten Fläche als durch das Alter der Warzen bestimmt. Bei immunkompetenten Personen muss es mit den hier aufgezeigten therapeutischen Methoden immer das Ziel sein, eine komplette Abheilung zu erzielen. PMID:27607029

  10. Herstellung von Chitosan und einige Anwendungen

    NASA Astrophysics Data System (ADS)

    Struszczyk, Marcin Henryk

    2001-05-01

    1. Die Deacetylierung von crabshell - Chitosan führte gleichzeitig zu einem drastischen Abfall der mittleren viscosimetrischen Molmasse ( Mv), insbesondere wenn die Temperatur und die Konzentration an NaOH erhöht werden. Diese Parameter beeinflussten jedoch nicht den Grad der Deacetylierung (DD). Wichtig ist jedoch die Quelle des Ausgangsmaterials: Chitin aus Pandalus borealis ist ein guter Rohstoff für die Herstellung von Chitosan mit niedrigem DD und gleichzeitig hoher mittlerer Mv, während Krill-Chitin (Euphausia superba) ein gutes Ausgangsmaterial zur Herstellung von Chitosan mit hohem DD und niedrigem Mv ist. Chitosan, das aus Insekten (Calliphora erythrocephala), unter milden Bedingungen (Temperatur: 100°C, NaOH-Konzentration: 40 %, Zeit: 1-2h ) hergestellt wurde, hatte die gleichen Eigenschaften hinsichtlich DD und Mv wie das aus Krill hergestellte Chitosan. Der Bedarf an Zeit, Energie und NaOH ist für die Herstellung von Insekten-Chitosan geringer als für crabshell-Chitosan vergleichbare Resultaten für DD und Mv. 2. Chitosan wurde durch den Schimmelpilz Aspergillus fumigatus zu Chitooligomeren fermentiert. Die Ausbeute beträgt 25%. Die Chitooligomere wurden mit Hilfe von HPLC und MALDI-TOF-Massenspektrmetrie identifiziert. Die Fermentationsmischung fördert die Immunität von Pflanzen gegen Bakterien und Virusinfektion. Die Zunahme der Immunität schwankt jedoch je nach System Pflanze-Pathogen. Die Fermentation von Chitosan durch Aspergillus fumigatus könnte eine schnelle und billige Methode zur Herstellung von Chitooligomeren mit guter Reinheit und Ausbeute sein. Eine partiell aufgereinigte Fermentationsmischung dieser Art könnte in der Landwirtschaft als Pathogeninhibitor genutzt werden. Durch kontrollierte Fermentation, die Chitooligomere in definierter Zusammensetzung (d.h. definierter Verteilung des Depolymerisationsgrades) liefert, könnte man zu Mischungen kommen, die für die jeweilige Anwendung eine optimale Bioaktivität besitzen. 3

  11. Dorfentwicklung und Dorferneuerung . Die neuen Bundesländer

    NASA Astrophysics Data System (ADS)

    Bender, Oliver; Richter, Horst P.

    1997-03-01

    Das 1975 in Kraft getretene Bundesraumordnungsprogramm forderte, in allen Landesteilen angemessene und gleichwertige Lebensbedingungen herzustellen. Mit der Novellierung des Flurbereinigungsgesetzes 1976 bzw. dem Zukunftsinvestitionsprogramm 1977 bis 1980 startete die Dorfentwicklung/Dorferneuerung nicht zuletzt als Initiative zur Konjunkturbelebung im ländlichen Raum. Seit 1984 ist sie Bestandteil der von Bund und Ländern getragenen Gemeinschaftsaufgabe "Verbesserung der Agrarstruktur und des Küstenschutzes" (GAK) und liegt im Zuständigkeitsbereich der Landwirtschaftsministerien. Die Dorferneuerungsprogramme der Länder werden aus Mitteln der GAK, der EU und des Landes finanziert. Neben Ortssanierungen nach dem Städtebauförderungsgesetz bzw. Baugesetzbuch stellen sie das wichtigste Instrument zur Förderung von ländlichen Orten und Gemeinden dar. Nach der Vereinigung wurde das Dorferneuerungsrecht auf die neuen Bundesländer übertragen, indem man sich zunächst an den Regelungen der jeweiligen Partnerländer im Westen orientierte. Doch hatten sich die Dörfer in Ost- und Westdeutschland nach dem Zweiten Weltkrieg völlig unterschiedlich entwickelt, so dass sich im Osten ein erweiterter Handlungsbedarf zeigte. Für Fachleute aus Politik, Verwaltung, Wissenschaft und freien Planungsberufen, nicht zuletzt für angewandt arbeitende Geographen, stellten sich neue Herausforderungen.

  12. Der neue Kosmos. Einführung in die Astronomie und Astrophysik

    NASA Astrophysics Data System (ADS)

    Unsöld, Albrecht; Baschek, Bodo

    Der neue Kosmos bietet in überschaubarem Umfang eine zusammenhängende Einführung in das Gesamtgebiet der Astronomie und Astrophysik. Aus den Bereichen: Klassische Astronomie und Planetensystem, Instrumente und Beobachtungsverfahren, Sonne und Sterne, Milchstraße und Galaxien, Kosmologie, Entstehung des Planetensystems, Entwicklung der Erde und des Lebens werden die Beobachtungsmethoden und die Ergebnisse astronomischer Forschung sowie deren theoretische Grundlagen und wechselseitigen Zusammenhänge vermittelt. Die aktualisierte 7. Auflage berücksichtigt den raschen Fortschritt astronomischer Forschung der letzten drei Jahre von unserem Planetensystem und den Entdeckungen zahlreicher Planeten bei anderen Sternen, über die fernsten Galaxien und Quasare bis zur Entwicklung der modernen Kosmologie.

  13. Renaturierung von subalpinen und alpinen Ökosystemen

    NASA Astrophysics Data System (ADS)

    Krautzer, B.; Klug, Brigitte

    Die große Vielfalt an alpinen und subalpinen Ökosystemen auf waldfreien Standorten stellt besonders hohe Anforderungen an Planung und Durchführung von Renaturierungsmaßnahmen. Zunehmende Meereshöhe, starke Hangneigungen und extreme klimatische Verhältnisse im Gebirge bedingen zudem seit jeher natürliche Erosionsprozesse. Die zahllosen menschlichen Aktivitäten der letzten Jahrzehnte, gepaart mit unzureichenden Begrünungsmaßnahmen, erhöhen dieses Risiko noch um ein Vielfaches: Geländekorrekturen im Zuge von Skipistenbauten, Almrevitalisierungen, Forst- und Almwegebauten, Maßnahmen zur Verbesserung der touristischen Infrastruktur oder Wildbach- und Lawinenverbauungen. Nur durch Verwendung von hochwertigem, dem Standort angepasstem Pflanzen-oder Saatgutmaterial in Kombination mit der passenden Begrünungstechnik kann dieser Bedrohung dauerhaft entgegengewirkt werden. Dabei sind folgende limitierende Faktoren besonders zu beachten.

  14. Strahlen-und kinetische Waffen: Neue Waffentechniken und Rüstungskontrolle

    NASA Astrophysics Data System (ADS)

    Neuneck, Götz

    Laserstrahlen, Mikrowellen oder elektromagnetische Beschleuniger lassen sich nicht nur für zivile, sondern für militärische Zwecke einsetzen. Die Aufgabe einer vorbeugenden Rüstungskontrolle wäre es, diese wie andere künftige Waffentechnologien auf ihren destabilisierenden Charakter hin zu untersuchen und ihre Stationierung zu beschränken oder zu verhindern.

  15. Exploring the Optical Transient Sky with the Palomar Transient Factory

    NASA Astrophysics Data System (ADS)

    Rau, Arne; Kulkarni, Shrinivas R.; Law, Nicholas M.; Bloom, Joshua S.; Ciardi, David; Djorgovski, George S.; Fox, Derek B.; Gal-Yam, Avishay; Grillmair, Carl C.; Kasliwal, Mansi M.; Nugent, Peter E.; Ofek, Eran O.; Quimby, Robert M.; Reach, William T.; Shara, Michael; Bildsten, Lars; Cenko, S. Bradley; Drake, Andrew J.; Filippenko, Alexei V.; Helfand, David J.; Helou, George; Howell, D. Andrew; Poznanski, Dovi; Sullivan, Mark

    2009-12-01

    The Palomar Transient Factory (PTF) is a wide-field experiment designed to investigate the optical transient and variable sky on time scales from minutes to years. PTF uses the CFH12k mosaic camera, with a field of view of 7.9 deg2 and a plate scale of 1'' pixel-1, mounted on the Palomar Observatory 48 inch Samuel Oschin Telescope. The PTF operation strategy is devised to probe the existing gaps in the transient phase space and to search for theoretically predicted, but not yet detected, phenomena, such as fallback supernovae, macronovae, .Ia supernovae, and the orphan afterglows of gamma-ray bursts. PTF will also discover many new members of known source classes, from cataclysmic variables in their various avatars to supernovae and active galactic nuclei, and will provide important insights into understanding galactic dynamics (through RR Lyrae stars) and the solar system (asteroids and near-Earth objects). The lessons that can be learned from PTF will be essential for the preparation of future large synoptic sky surveys like the Large Synoptic Survey Telescope. In this article we present the scientific motivation for PTF and describe in detail the goals and expectations for this experiment.

  16. Spectroscopic Classifications of Optical Transients with SOAR

    NASA Astrophysics Data System (ADS)

    Hounsell, R. A.; Miller, J. A.; Pan, Y.-C.; Foley, R. J.; Jha, S. W.; Rest, A.; Scolnic, D.; Smith, K. W.; Wright, D.; Smartt, S. J.; Huber, M.; Chambers, K. C.; Flewelling, H.; Willman, M.; Primak, N.; Schultz, A.; Gibson, B.; Magnier, E.; Waters, C.; Tonry, J.; Wainscoat, R. J.

    2016-06-01

    We report the following classifications of optical transients from spectroscopic observations with the Goodman spectrograph on the SOAR 4-m telescope. Targets were supplied by the Pan-STARRS Survey for Transients (PSST).

  17. Superresolution microscopy with transient binding.

    PubMed

    Molle, Julia; Raab, Mario; Holzmeister, Susanne; Schmitt-Monreal, Daniel; Grohmann, Dina; He, Zhike; Tinnefeld, Philip

    2016-06-01

    For single-molecule localization based superresolution, the concentration of fluorescent labels has to be thinned out. This is commonly achieved by photophysically or photochemically deactivating subsets of molecules. Alternatively, apparent switching of molecules can be achieved by transient binding of fluorescent labels. Here, a diffusing dye yields bright fluorescent spots when binding to the structure of interest. As the binding interaction is weak, the labeling is reversible and the dye ligand construct diffuses back into solution. This approach of achieving superresolution by transient binding (STB) is reviewed in this manuscript. Different realizations of STB are discussed and compared to other localization-based superresolution modalities. We propose the development of labeling strategies that will make STB a highly versatile tool for superresolution microscopy at highest resolution. PMID:26773299

  18. [Transient abnormal Q-waves].

    PubMed

    Godballe, C; Hoeck, H C; Sørensen, J A

    1990-01-01

    We present a case of transient abnormal Q-waves (TAQ) and a review of the literature. TAQ are defined as abnormal Q-waves, which disappear within ten days. They are most often seen in patients with ischemic heart disease (IHD) but are also seen in other conditions. Brief episodes of myocardial ischemia giving rise to reversible biochemical and ultrastructural myocardial changes, resulting in transient ECG changes, provide an accepted theory for the pathogenesis of TAO. Investigations have shown that the occurrence of exercise-induced TAQ may be a symptom of IHD. It is impossible to distinguish TAQ from Q-waves induced by myocardial infarction. Appearance of TAQ during exercise-testing frequently indicates IHD. PMID:2301045

  19. Model refinement using transient response

    SciTech Connect

    Dohrmann, C.R.; Carne, T.G.

    1997-12-01

    A method is presented for estimating uncertain or unknown parameters in a mathematical model using measurements of transient response. The method is based on a least squares formulation in which the differences between the model and test-based responses are minimized. An application of the method is presented for a nonlinear structural dynamic system. The method is also applied to a model of the Department of Energy armored tractor trailer. For the subject problem, the transient response was generated by driving the vehicle over a bump of prescribed shape and size. Results from the analysis and inspection of the test data revealed that a linear model of the vehicle`s suspension is not adequate to accurately predict the response caused by the bump.

  20. Superresolution microscopy with transient binding.

    PubMed

    Molle, Julia; Raab, Mario; Holzmeister, Susanne; Schmitt-Monreal, Daniel; Grohmann, Dina; He, Zhike; Tinnefeld, Philip

    2016-06-01

    For single-molecule localization based superresolution, the concentration of fluorescent labels has to be thinned out. This is commonly achieved by photophysically or photochemically deactivating subsets of molecules. Alternatively, apparent switching of molecules can be achieved by transient binding of fluorescent labels. Here, a diffusing dye yields bright fluorescent spots when binding to the structure of interest. As the binding interaction is weak, the labeling is reversible and the dye ligand construct diffuses back into solution. This approach of achieving superresolution by transient binding (STB) is reviewed in this manuscript. Different realizations of STB are discussed and compared to other localization-based superresolution modalities. We propose the development of labeling strategies that will make STB a highly versatile tool for superresolution microscopy at highest resolution.

  1. Transient Ablation of Teflon Hemispheres

    NASA Technical Reports Server (NTRS)

    Arai, Norio; Karashima, Kei-ichi; Sato, Kiyoshi

    1997-01-01

    For high-speed entry of space vehicles into atmospheric environments, ablation is a practical method for alleviating severe aerodynamic heating. Several studies have been undertaken on steady or quasi-steady ablation. However, ablation is a very complicated phenomenon in which a nonequilibrium chemical process is associated with an aerodynamic process that involves changes in body shape with time. Therefore, it seems realistic to consider that ablation is an unsteady phenomenon. In the design of an ablative heat-shield system, since the ultimate purpose of the heat shield is to keep the internal temperature of the space vehicle at a safe level during entry, the transient heat conduction characteristics of the ablator may be critical in the selection of the material and its thickness. This note presents an experimental study of transient ablation of Teflon, with particular emphasis on the change in body shape, the instantaneous internal temperature distribution, and the effect of thermal expansion on ablation rate.

  2. Pressure transient in liquid lines

    SciTech Connect

    Sun, J.G.; Wang, X.Q.

    1995-07-01

    The pressure surge that results from a step change of flow in liquid pipelines, commonly known as water hammer, was analyzed by an eigenfunction method. A differential-integral Pressure wave equation and a linearized velocity equation were derived from the equations of mass and momentum conservation. Waveform distortion due to viscous dissipation and pipe-wall elastic expansion is characterized by a dimensionless transmission number K. The pressure surge condition, which is mathematically singular, was used in the solution procedure. The exact solutions from numerical calculation of the differential-integral equation provide a complete Pressure transient in the pipe. The problems are also calculated With the general-purpose computer code COMMIX, which solves the exact mass conservation equation and Navier-Stokes equations. These solutions were compared with published experimental results, and agreement was good. The effect of turbulence on the pressure transient is discussed in the light of COMMIX calculational results.

  3. Transient simulation of absorption machines

    NASA Astrophysics Data System (ADS)

    Anand, D. K.; Allen, R. W.; Kumar, B.

    A model for a water-cooled Lithium-Bromide/water absorption chiller is presented. Its transient response both during the start-up phase and during the shut-off period is predicted. The simulation model incorporates such influencing factors as the thermodynamic properties of the working fluid, the absorbent, the heat-transfer configuration of different components of the chiller and related physical data. The time constants of different components are controlled by a set of key parameters that have been identified. The results show a variable but at times significant amount of time delay before the chiller capacity gets close to its steady-state value. The model is intended to provide an insight into the mechanism of build-up to steady-state performance. By recognizing the significant factors contributing to transient degradation, steps can be taken to reduce such degradation.

  4. Nonlinear Diffusion and Transient Osmosis

    NASA Astrophysics Data System (ADS)

    Akira, Igarashi; Lamberto, Rondoni; Antonio, Botrugno; Marco, Pizzi

    2011-08-01

    We investigate both analytically and numerically the concentration dynamics of a solution in two containers connected by a narrow and short channel, in which diffusion obeys a porous medium equation. We also consider the variation of the pressure in the containers due to the flow of matter in the channel. In particular, we identify a phenomenon, which depends on the transport of matter across nano-porous membranes, which we call “transient osmosis". We find that nonlinear diffusion of the porous medium equation type allows numerous different osmotic-like phenomena, which are not present in the case of ordinary Fickian diffusion. Experimental results suggest one possible candidate for transiently osmotic processes.

  5. ATLAS discoveries of optical transients

    NASA Astrophysics Data System (ADS)

    Tonry, J.; Denneau, L.; Stalder, B.; Heinze, A.; Sherstyuk, A.; Rest, A.; Smith, K. W.; Smartt, S. J.

    2016-09-01

    We report the following transients found by the ATLAS survey (see Tonry et al. ATel #8680). ATLAS is a twin 0.5m telescope system on Haleakala and Mauna Loa. The first unit is operational on Haleakala is robotically surveying the sky. Two filters are used, cyan and orange (denoted c and o, all mags in AB system), more information is on http://www.fallingstar.com.

  6. ATLAS discoveries of optical transients

    NASA Astrophysics Data System (ADS)

    Tonry, J.; Denneau, L.; Stalder, B.; Heinze, A.; Sherstyuk, A.; Rest, A.; Smith, K. W.; Smartt, S. J.

    2016-06-01

    We report the following transients found by the ATLAS survey (see Tonry et al. ATel #8680). ATLAS is a twin 0.5m telescope system on Haleakala and Mauna Loa. The first unit is operational on Haleakala is robotically surveying the sky. Two filters are used, cyan and orange (denoted c and o, all mags in AB system), more information is on http://www.fallingstar.com.

  7. ATLAS discoveries of optical transients

    NASA Astrophysics Data System (ADS)

    Tonry, J.; Denneau, L.; Stalder, B.; Heinze, A.; Sherstyuk, A.; Rest, A.; Smith, K. W.; Smartt, S. J.

    2016-08-01

    We report the following transients found by the ATLAS survey (see Tonry et al. ATel #8680). ATLAS is a twin 0.5m telescope system on Haleakala and Mauna Loa. The first unit is operational on Haleakala is robotically surveying the sky. Two filters are used, cyan and orange (denoted c and o, all mags in AB system), more information is on http://www.fallingstar.com.

  8. Nonlinear transient simulation of transformers

    SciTech Connect

    Pierrat, L.; Tran-Quoc, T. |; Montmeat, A.

    1995-12-31

    In this paper, a nonlinear model of transformer which takes into account both the saturation and the hysteresis is proposed. In order to simulate transient phenomena in transformers, a system of equations is presented. The digital simulation of the energization and de-energization of a three-phase distribution transformer is studied. Ferroresonant phenomena in iron core transformers supplied through capacitive links are presented. Finally, the influence of MOV arresters on overvoltage reduction is investigated.

  9. ATLAS discoveries of optical transients

    NASA Astrophysics Data System (ADS)

    Tonry, J.; Denneau, L.; Stalder, B.; Heinze, A.; Sherstyuk, A.; Rest, A.; Smith, K. W.; Smartt, S. J.

    2016-10-01

    We report the following transients found by the ATLAS survey (see Tonry et al. ATel #8680). ATLAS is a twin 0.5m telescope system on Haleakala and Mauna Loa. The first unit is operational on Haleakala is robotically surveying the sky. Two filters are used, cyan and orange (denoted c and o, all mags in AB system), more information is on http://www.fallingstar.com.

  10. Possible Nearby Transient discovered by PSST

    NASA Astrophysics Data System (ADS)

    Wright, D.; Smith, K. W.; Smartt, S. J.; Huber, M.; Chambers, K. C.; Flewelling, H.; Willman, M.; Primak, N.; Schultz, A.; Gibson, B.; Magnier, E.; Waters, C.; Tonry, J.; Wainscoat, R. J.; Foley, R. J.; Jha, S. W.; Rest, A.; Scolnic, D.

    2016-01-01

    A transient, which is a possible nearby supernova, has been discovered as part of the Pan-STARRS Survey for Transients (PSST). Information on all objects discovered by the Pan-STARRS Survey for Transients is available at http://star.pst.qub.ac.uk/ps1threepi/ (see Huber et al. ATel #7153).

  11. Entwicklungsperspektiven von Social Software und dem Web 2.0

    NASA Astrophysics Data System (ADS)

    Raabe, Alexander

    Der Artikel beschäftigt sich zunächst mit dem derzeitigen und zukünftigen Einsatz von Social Software in Unternehmen. Nach dem großen Erfolg von Social Software im Web beginnen viele Unternehmen eigene Social Software-Initiativen zu entwickeln. Der Artikel zeigt die derzeit wahrgenommenen Einsatzmöglichkeiten von Social Software im Unternehmen auf, erörtert Erfolgsfaktoren für die Einführung und präsentiert mögliche Wege für die Zukunft. Nach der Diskussion des Spezialfalles Social Software in Unternehmen werden anschließend die globalen Trends und Zukunftsperspektiven des Web 2.0 in ihren technischen, wirtschaftlichen und sozialen Dimensionen dargestellt. Wie aus den besprochenen Haupttrends hervorgeht, wird die Masse an digital im Web verfügbaren Informationen stetig weiterwachsen. So stellt sich die Frage, wie es in Zukunft möglich sein wird, die Qualität der Informationssuche und der Wissensgenerierung zu verbessern. Mit dem Einsatz von semantischen Technologien im Web wird hier eine revolutionäre Möglichkeit geboten, Informationen zu filtern und intelligente, gewissermaßen verstehende" Anwendungen zu entwerfen. Auf dem Weg zu einem intelligenten Web werden sich das Semantic Web und Social Software annähern: Anwendungen wie Semantic Wikis, Semantic Weblogs, lightweight Semantic Web-Sprachen wie Microformats oder auch kommerzielle Angebote wie Freebase von Metaweb werden die ersten Vorzeichen einer dritten Generation des Webs sein.

  12. Darwinische Kulturtheorie - Evolutionistische und "evolutionistische`` Theorien sozialen Wandels

    NASA Astrophysics Data System (ADS)

    Antweiler, Christoph

    Evolutionistische Argumentationen außerhalb der Biologie sind weit verbreitet. Wenn sie vertreten werden, heißt das mitnichten, dass sie notwendigerweise von darwinischen Argumenten geprägt sind. Wenn man Evolution und Kultur aus explizit darwinischer Perspektive zusammen bringt, bedeutet das noch lange nicht unbedingt Soziobiologie. Und es bedeutet sicherlich nicht Sozialdarwinismus. Dieser Beitrag soll einen Überblick der so genannten evolutionären Ansätze bzw. evolutionistischen Ansätze zu menschlichen Gesellschaften bzw. Kulturen geben. Es soll gezeigt werden, was in den Ansätzen analytisch zu trennen ist und was synthetisch zusammen gehört. Mein Beitrag ist nicht wissenschaftsgeschichtlich angelegt, sondern systematisch ausgerichtet und hat zwei Schwerpunkte (Antweiler 2008; Antweiler 2009b). Zum einen geht es um kausale Zusammenhänge von organischer Evolution und gesellschaftlichem Wandel. Auf der anderen Seite werden Analogien zwischen biotischer und kultureller Evolution erläutert, die als spezifische Ähnlichkeiten dieser beiden als grundsätzlich verschieden gesehenen Prozesse aufgefasst werden. Dadurch wird die Frage aufgeworfen, ob die Evolution von Organismen einerseits und die Transformation von Gesellschaften bzw. Kulturen andererseits, spezielle Fälle eines allgemeinen Modells von Evolution darstellen.

  13. Transient-mode multipactor discharge

    NASA Astrophysics Data System (ADS)

    Graves, T. P.; Spektor, R.; Stout, P.; Axley, A.

    2009-08-01

    Multipactor discharge is a resonant condition in which electrons impact material surfaces in phase with an alternating rf or microwave electric field. A growing and/or sustained discharge requires the electrode secondary electron coefficient, δ(Ee), to be greater than unity at the impacting electron energy (Ee). E1, the minimum energy for δ =1, is highly dependent on electrode surface preparation and conditioning, and contaminated surfaces will generally experience a lower E1 than the same clean or "conditioned" surface. A transient mode of multipactor discharge can exist when the multipactor electron energy distribution occurs near E1. The transient nature of such a discharge is shown to result from dynamic changes in E1 due to multipactor conditioning and surface contamination. Experimental data depict transient-mode multipactor (TMM) discharges at a range of rf voltages and chamber pressures for both copper and aluminum electrodes. TMM was detected using a biased current probe, and these events were undetectable by third harmonic diagnostics at chamber pressures below 1×10-3 torr. Discharge parameters such as charge density, period, and duty cycle are shown to be related to both the rf voltage and the chamber pressure. Monte Carlo simulation results support the experimental findings, showing an exponential decrease in the resonant electron population with increasing E1.

  14. Transient Response in LMFBR System.

    1999-04-26

    SSC-L (the Super System Code) calculates the thermohydraulic response of loop-type liquid metal fast breeder reactor (LMFBR) systems during operational, incidental, and accidental transients, especially natural circulation events. Modules simulated and parameters calculated include: core flow rates and temperatures, loop flow rates and temperatures, pump performance, and heat exchanger operation. Additionally, SSC-L accounts for all plant protection and plant control systems. Although the primary emphasis is on transients for safety analysis, SSC-L can be usedmore » for many other applications, such as scoping analysis for plant design and specification of various components. Any number of user-specified loops, pipes, and nodes are permitted. Both single- and two-phase thermal-hydraulics are used in a multi-channel core representation. Inter-assembly flow redistribution is accounted for using a detailed fuel pin model. The heat transport system geometry is user-specified. SSC-L provides steady-state and transient options and a restart capability. Input is free format in a modular structure that makes use of abstract data management techniques.« less

  15. Spectral signatures of penumbral transients

    SciTech Connect

    Reardon, K.; Tritschler, A.

    2013-12-20

    In this work we investigate the properties of penumbral transients observed in the upper photospheric and chromospheric region above a sunspot penumbra using two-dimensional spectroscopic observations of the Ca II 854.21 nm line with a 5 s cadence. In our 30 minutes of observations, we identify several penumbral-micro jets (PMJs) with cotemporal observations from Dunn Solar Telescope/IBIS and Hinode/SOT. We find that the line profiles of these PMJ events show emission in the two wings of the line (±0.05 nm), but little modification of the line core. These are reminiscent of the line profiles of Ellerman bombs observed in plage and network regions. Furthermore, we find evidence that some PMJ events have a precursor phase starting 1 minute prior to the main brightening that might indicate initial heating of the plasma prior to an acoustic or bow shock event. With the IBIS data, we also find several other types of transient brightenings with timescales of less than 1 minute that are not clearly seen in the Hinode/SOT data. The spectral profiles and other characteristics of these events are significantly different from those of PMJs. The different appearances of all these transients are an indicator of the general complexity of the chromospheric magnetic field and underscore the highly dynamic behavior above sunspots. It also highlights the care that is needed in interpreting broadband filter images of chromospheric lines, which may conceal very different spectral profiles, and the underlying physical mechanisms at work.

  16. Igniter heater EMI transient test

    NASA Technical Reports Server (NTRS)

    Cook, M.

    1989-01-01

    Testing to evaluate Redesigned Solid Rocket Motor igniter heater electromagnetic interference (EMI) effects on the Safe and Arm (S and A) device was completed. It was suspected that EMI generated by the igniter heater and it's associated electromechanical relay could cause a premature firing of the NASA Standard Initiators (NSIs) inside the S and A. The maximum voltage induced into the NSI fire lines was 1/4 of the NASA specified no-fire limit of one volt (SKB 26100066). As a result, the igniter heaters are not expected to have any adverse EMI effects on the NSIs. The results did show, however, that power switching causes occasional high transients within the igniter heater power cable. These transients could affect the sensitive equipment inside the forward skirt. It is therefore recommended that the electromechanical igniter heater relays be replaced with zero crossing solid state relays. If the solid state relays are installed, it is also recommended that they be tested for EMI transient effects.

  17. Das CARNOTsche Paradigma und seine erkenntnistheoretischen Implikationen

    NASA Astrophysics Data System (ADS)

    Schöpf, Hans-Georg

    Der vorliegende historisch-kritische Essay führt die Eigentümlichkeiten der klassischen phänomenologischen Thermodynamik auf das von CARNOT geschaffene Paradigma zurück und greift einige damit zusammenhängende Fragen auf.Translated AbstractCARNOT's Paradigm and its Epistemological ImplicationsThe present historic-critical essay traces the pecularities of classical phenomenological thermodynamics back to the paradigm, created by CARNOT, and takes up some questions to which this paradigm gives rise.

  18. Transient combustion in hybrid rockets

    NASA Astrophysics Data System (ADS)

    Karabeyoglu, Mustafa Arif

    1998-09-01

    Hybrid rockets regained interest recently as an alternative chemical propulsion system due to their advantages over the solid and liquid systems that are currently in use. Development efforts on hybrids revealed two important problem areas: (1) low frequency instabilities and (2) slow transient response. Both of these are closely related to the transient behavior which is a poorly understood aspect of hybrid operation. This thesis is mainly involved with a theoretical study of transient combustion in hybrid rockets. We follow the methodology of identifying and modeling the subsystems of the motor such as the thermal lags in the solid, boundary layer combustion and chamber gasdynamics from a dynamic point of view. We begin with the thermal lag in the solid which yield the regression rate for any given wall heat flux variation. Interesting phenomena such as overshooting during throttling and the amplification and phase lead regions in the frequency domain are discovered. Later we develop a quasi-steady transient hybrid combustion model supported with time delays for the boundary layer processes. This is integrated with the thermal lag system to obtain the thermal combustion (TC) coupled response. The TC coupled system with positive delays generated low frequency instabilities. The scaling of the instabilities are in good agreement with actual motor test data. Finally, we formulate a gasdynamic model for the hybrid chamber which successfully resolves the filling/emptying and longitudinal acoustic behavior of the motor. The TC coupled system is later integrated to the gasdynamic model to obtain the overall response (TCG coupled system) of gaseous oxidizer motors with stiff feed systems. Low frequency instabilities were also encountered for the TCG coupled system. Apart from the transient investigations, the regression rate behavior of liquefying hybrid propellants such as solid cryogenic materials are also studied. The theory is based on the possibility of enhancement

  19. [Leben im Eismeer - Tauchuntersuchungen zur Biologie arktischer Meerespflanzen und Meerestiere

    PubMed

    Lippert; Karsten; Wiencke

    2000-01-01

    Die Maske wird nochmals auf Dichtigkeit überprüft, der Knoten der Sicherungsleine mit zwei halben Schlägen fixiert, dann rutscht die Taucherin von der Eiskante in das kalte Wasser. Eine halbe Stunde vergeht, bevor ihr Kopf wieder aus dem Eisloch auftaucht und sie ein großes Sammelnetz nach oben reicht, gefüllt mit verschiedenen Arten von Makroalgen. Obwohl noch große Flächen des Kongsfjordes im arktischen Spitzbergen zugefroren sind und das Festland von einer dicken Schneedecke bedeckt ist, hat unter Wasser in den Algenwäldern bereits der Sommer und damit die Saison der Meeresbiologen begonnen.

  20. Diagnose und Therapie einer Depression im höheren Lebensalter – Einflüsse von Patienten- und Arztmerkmalen

    PubMed Central

    von dem Knesebeck, Olaf; Bönte, Markus; Siegrist, Johannes; Marceau, Lisa; Link, Carol; McKinlay, John

    2013-01-01

    Zusammenfassung Studienergebnissee aus dem englischsprachigen Raum zeigen, dass diagnostische und therapeutische Entscheidungen von Hausärzten bei der Versorgung von depressiven Patienten systematischen Einflüssen unterliegen, und dass sowohl Merkmale des Arztes als auch des Patienten unabhängig vom Krankheitsbild Einfluss auf diese Entscheidungen haben. In der vorliegenden Arbeit werden Ergebnisse einer deutschen Studie präsentiert, in der die Einflüsse von Patienten- und Arztmerkmalen auf diagnostische und therapeutische ärztliche Entscheidungen bei einer Depression untersucht wurden. Unter Anwendung eines faktoriellen Experimentaldesigns spielten professionelle Schauspieler in Videofilmen die Rolle von Patienten, die Symptome für eine depressive Erkrankung äußern. In den Videofilmen, die alle auf einem identischen Skript basieren, wurden systematisch die Patientenmerkmale Alter (55 vs. 75 Jahre), Geschlecht und sozialer Status (Hausmeister vs. Lehrer) variiert. Die randomisierte Ärztestichprobe wurde nach dem Arztgeschlecht und professioneller Erfahrung (< 5 vs. > 15 Jahre) geschichtet. Der Videofilm wurde insgesamt 128 niedergelassenen Ärzten für Allgemeinmedizin und hausärztlich tätigen Internisten in ihrer Praxis vorgespielt. Danach wurden die Ärzte zu unterschiedlichen Aspekten von Diagnose und Therapie befragt. Es wurde erhoben, ob der Arzt dem Patienten über das gezeigte Gespräch hinausgehende Fragen stellen würde, welche Diagnosen er für wahrscheinlich hält, wie sicher er sich mit seiner Diagnose ist, welche diagnostischen Tests er anordnen würde, ob er den Patienten überweisen würde oder ob er Medikamente verordnen oder ihm Empfehlungen zur Änderung seines Lebensstils geben würde. Die Ergebnisse weisen darauf hin, dass sowohl die Diagnose als auch die Therapie einer Depression durch niedergelassene Hausärzte in Deutschland nur geringfügig durch die untersuchten Merkmale der Patienten und der behandelnden Ärzte beeinflusst wird

  1. Transient-induced climate drift

    SciTech Connect

    Johansson, A.; Reinhold, B.; Saha, S. )

    1993-05-01

    The climate drift of various quantities associated with deep, planetary-scale, equilibrated, transient Rossby waves are estimated for the Southern Hemisphere extratropical summer as revealed by the DERF II (Dynamical Extended Range Forecasting) dataset. It is found that the vertical structures of these waves systematically become too baroclinic during the course of integration. There are two time scales associated with this climate drift. There is one very short time scale, estimated to be of the order of one day, when the waves become more barotropic. It is followed by a period when the wave baroclinicity monotonically increases, and after roughly 10 days the model structures appear to have reached their statistically equilibrated state. In the meantime, the kinetic energy of the transient waves decreases substantially to roughly half the observed value. After this initial drop, however, the transient kinetic energy increases again, and it is not clear if an equilibrium value has been reached after 30 days, which is the limit of the DERF II dataset. This third time scale is not found in the quantities directly associated with the vertical structures per se, but it is hypothesized to be a consequence of these errors. A theory is utilized that in a simplified way takes into account the processes that determine the vertical structure of baroclinic waves as well as their robustness as a means of understanding the processes leading to these errors. The implications from this theory are that the formulation and magnitude of the dissipative and diffusive processes in the model are the most likely problem, but there are other possibilities. 37 refs., 10 figs.

  2. Transient eddy current flow metering

    NASA Astrophysics Data System (ADS)

    Forbriger, J.; Stefani, F.

    2015-10-01

    Measuring local velocities or entire flow rates in liquid metals or semiconductor melts is a notorious problem in many industrial applications, including metal casting and silicon crystal growth. We present a new variant of an old technique which relies on the continuous tracking of a flow-advected transient eddy current that is induced by a pulsed external magnetic field. This calibration-free method is validated by applying it to the velocity of a spinning disk made of aluminum. First tests at a rig with a flow of liquid GaInSn are also presented.

  3. Transient thermal convection in microgravity

    NASA Technical Reports Server (NTRS)

    Dressler, R. F.

    1981-01-01

    The unsteady two-dimensional thermal convection in a cylinder due to a transient acceleration solved for a step-function excitation. From this, the solution was obtained for an arbitrary time-dependent acceleration. The solutions are valied for sufficiently low Rayleigh numbers and therefore, relevant to microgravity fields. As an example, two graphs are presented for he convection resulting from the movement of an astronaut inside the Shuttle. The analysis can be applied to obtain any other convective flows such as those caused by g-jitter or variable rotation of the Shuttle.

  4. Observations of Solar Radio Transients

    NASA Astrophysics Data System (ADS)

    Paige, Giorla

    2011-05-01

    A low frequency radio telescope has been recently been constructed on the campus of the The College of New Jersey (TCNJ) and has begun conducting observations at 20MHz as part of NASA'a Radio Jove program. This instrument is capable of observations of solar radio emission including strong prompt radio emission associated with solar burst events. We will discuss solar observations conducted with this instrument as well as an effort to conduct coincident observations with the Eight-meter-wavelength Transient Array (ETA) and the Long Wavelength Array (LWA).

  5. Transient Wellbore Fluid Flow Model

    1982-04-06

    WELBORE is a code to solve transient, one-dimensional two-phase or single-phase non-isothermal fluid flow in a wellbore. The primary thermodynamic variables used in solving the equations are the pressure and specific energy. An equation of state subroutine provides the density, quality, and temperature. The heat loss out of the wellbore is calculated by solving a radial diffusion equation for the temperature changes outside the bore. The calculation is done at each node point in themore » wellbore.« less

  6. The Women of "Kabale und Liebe": A Teaching Approach

    ERIC Educational Resources Information Center

    Stephan, Naomi I.

    1976-01-01

    The three female characters in Schiller's "Kabale und Liebe" are analyzed. The article questions the value of using this play in a college curriculum because of the oppressive and unenlightened roles of the female characters. (TL)

  7. Konstruieren von Pkw-Karosserien: Grundlagen, Elemente und Baugruppen, Vorschriftenübersicht, Beispiele mit CATIA V4 und V5

    NASA Astrophysics Data System (ADS)

    Grabner, Jörg; Nothhaft, Richard

    Die Faszination, die vom Auto ausgeht, ist und bleibt ungebrochen. Entsprechend interessant ist es, sich vor dem Hintergrund konventioneller Konstruktionstechniken über die virtuelle Produktentwicklung von Pkw-Karosserien an modernen CAD-Arbeitsplätzen informieren zu können. Die Autoren führen in die Grundlagen ein und zeigen anhand von Beispielen und zahlreichen Abbildungen, wie mit dem System CATIA der Rohbau sowie die Ausstattung innen und au=C3=9Fen konstruiert werden. Darüber hinaus wird das so genannte "Package" an Beispielen beschrieben, also das Management und die Harmonisierung der Anforderungen an die Bauräume (z.

  8. Einstellung und Wissen von Lehramtsstudierenden zur Evolution - ein Vergleich zwischen Deutschland und der Türkei

    NASA Astrophysics Data System (ADS)

    Graf, Dittmar; Soran, Haluk

    Es wird eine Untersuchung vorgestellt, in der Wissen und Überzeugungen von Lehramtsstudierenden aller Fächer zum Thema Evolution an zwei Universitäten in Deutschland und der Türkei erhoben worden sind. Die Befragung wurde in Dortmund und in Ankara durchgeführt. Es stellte sich heraus, dass ausgeprägte Defizite im Verständnis der Evolutionsmechanismen herrschen. Viele Studierende, insbesondere aus der Türkei, sind nicht von der Faktizität der Evolution überzeugt. Dies gilt sowohl für Studierende mit Fach Biologie als auch für Studierende mit anderen Fächern. Näher untersucht worden sind die Faktoren, die die Überzeugungen zur Evolution beeinflussen können, was ja in Anbetracht der hohen Ablehnungsrate der Evolution von besonderem Interesse ist. Das Vertrauen in die Wissenschaft spielt hierbei eine besondere Rolle: Wer der Wissenschaft vertraut, ist auch eher von der Evolution überzeugt, als diejenigen, die skeptisch gegenüber der Wissenschaft sind.

  9. Physik gestern und heute Von der Metallstange zum Hochenergielaser

    NASA Astrophysics Data System (ADS)

    Heering, Peter

    2002-05-01

    Im Mai 1752 wurde in Marly bei Paris auf Anregung des amerikanischen Forschers und Politikers Benjamin Franklin erstmals die elektrische Natur des Blitzes nachgewiesen. Damals beschrieb Franklin auch eine technische Vorrichtung, die als Schutz von Gebäuden vor Blitzschlägen dienen sollte: den Blitzableiter. Diese aus heutiger Sicht scheinbar triviale Vorrichtung wurde aber keineswegs unmittelbar akzeptiert. Und bis heute ist die Forschung zum Schutz von Einrichtungen vor Blitzschlägen nicht abgeschlossen.

  10. Transient effects in Herschel/PACS spectroscopy

    NASA Astrophysics Data System (ADS)

    Fadda, Dario; Jacobson, Jeffery D.; Appleton, Philip N.

    2016-10-01

    Context. The Ge:Ga detectors used in the PACS spectrograph onboard the Herschel space telescope react to changes of the incident flux with a certain delay. This generates transient effects on the resulting signal which can be important and last for up to an hour. Aims: The paper presents a study of the effects of transients on the detected signal and proposes methods to mitigate them especially in the case of the unchopped mode. Methods: Since transients can arise from a variety of causes, we classified them in three main categories: transients caused by sudden variations of the continuum due to the observational mode used; transients caused by cosmic ray impacts on the detectors; transients caused by a continuous smooth variation of the continuum during a wavelength scan. We propose a method to disentangle these effects and treat them separately. In particular, we show that a linear combination of three exponential functions is needed to fit the response variation of the detectors during a transient. An algorithm to detect, fit, and correct transient effects is presented. Results: The solution proposed to correct the signal for the effects of transients substantially improves the quality of the final reduction with respect to the standard methods used for archival reduction in the cases where transient effects are most pronounced. Conclusions: The programs developed to implement the corrections are offered through two new interactive data reduction pipelines in the latest releases of the Herschel Interactive Processing Environment.

  11. Transient simulation of absorption machines

    NASA Astrophysics Data System (ADS)

    Anand, D. K.; Allen, R. W.; Kumar, B.

    1982-08-01

    This paper presents a model for a water-cooled Lithium-Bromide/water absorption chiller and predicts its transient response both during the start-up phase and during the shutoff period. The simulation model incorporates such influencing factors as the thermodynamic properties of the working fluid, the absorbent, the heat-transfer configuration of different components of the chiller and related physical data. The time constants of different components are controlled by a set of key parameters that have been identified in this study. The results show a variable but at times significant amount of time delay before the chiller capacity gets close to its steady-state value. The model is intended to provide an insight into the mechanism of build-up to steady-state performance. By recognizing the significant factors contributing to transient degradation, steps can be taken to reduce such degradation. The evaluation of the residual capacity in the shut-off period will yield more realistic estimates of chiller COP for a chiller satisfying dynamic space cooling load.

  12. PRISMATIC CORE COUPLED TRANSIENT BENCHMARK

    SciTech Connect

    J. Ortensi; M.A. Pope; G. Strydom; R.S. Sen; M.D. DeHart; H.D. Gougar; C. Ellis; A. Baxter; V. Seker; T.J. Downar; K. Vierow; K. Ivanov

    2011-06-01

    The Prismatic Modular Reactor (PMR) is one of the High Temperature Reactor (HTR) design concepts that have existed for some time. Several prismatic units have operated in the world (DRAGON, Fort St. Vrain, Peach Bottom) and one unit is still in operation (HTTR). The deterministic neutronics and thermal-fluids transient analysis tools and methods currently available for the design and analysis of PMRs have lagged behind the state of the art compared to LWR reactor technologies. This has motivated the development of more accurate and efficient tools for the design and safety evaluations of the PMR. In addition to the work invested in new methods, it is essential to develop appropriate benchmarks to verify and validate the new methods in computer codes. The purpose of this benchmark is to establish a well-defined problem, based on a common given set of data, to compare methods and tools in core simulation and thermal hydraulics analysis with a specific focus on transient events. The benchmark-working group is currently seeking OECD/NEA sponsorship. This benchmark is being pursued and is heavily based on the success of the PBMR-400 exercise.

  13. Special issue on transient plasmas

    NASA Astrophysics Data System (ADS)

    Bailey, James; Hoarty, David; Mancini, Roberto; Yoneda, Hitoki

    2015-11-01

    This special issue of Journal of Physics B: Atomic, Molecular and Optical Physics is dedicated to the "spectroscopy of transient plasmas" covering plasma conditions produced by a range of pulsed laboratory sources including short and long pulse lasers, pulsed power devices, and free electron lasers (FELs). The full range of plasma spectroscopy up to high energy bremsstrahlung radiation, including line broadening analysis for application to data recorded with the ChemCam instrument on the Mars Science Laboratory rover Curiosity, is covered. This issue is timely as advances in optical lasers and x-ray FELs (XFEL) are enabling transient plasma to be probed at higher energies and shorter durations than ever before. New XFEL facilities being commissioned in Europe and Asia are adding to those operating in the US and Japan and the ELI high power laser project in Europe, due to open this year, will provide short pulse lasers of unprecedented power. This special issue represents a snapshot of the theoretical and experimental research in dense plasmas, electron kinetics, laser-induced breakdown spectroscopy of low temperature plasmas, inertial confinement fusion and non-equilibrium atomic physics using spectroscopy to diagnose plasmas produced by optical lasers, XFELs and pulsed-power machines.

  14. Postseismic relaxation and transient creep

    USGS Publications Warehouse

    Savage, J.C.; Svarc, J.L.; Yu, S.-B.

    2005-01-01

    Postseismic deformation has been observed in the epicentral area following the 1992 Landers (M = 7.3), 1999 Chi-Chi (M = 7.6), 1999 Hector Mine (M = 7.1), 2002 Denali (M = 7.9), 2003 San Simeon (M = 6.5), and 2004 Parkfield (M = 6.0) earthquakes. The observations consist of repeated GPS measurements of the position of one monument relative to another (separation ???100 km). The early observations (t < 0.1 year) are well fit by the function a' + c'log(t), where t is the time after the earthquake and a' and c' are constants chosen to fit the data. Because a log(t) time dependence is characteristic of transient (primary) creep, the early postseismic response may be governed by transient creep as Benioff proposed in 1951. That inference is provisional as the stress conditions prevailing in postseismic relaxation are not identical to the constant stress condition in creep experiments. The observed logarithmic time dependence includes no characteristic time that might aid in identifying the micromechanical cause.

  15. Sticktechnologie für medizinische Textilien und Tissue Engineering

    NASA Astrophysics Data System (ADS)

    Karamuk, Erdal; Mayer, Jörg; Wintermantel, Erich

    Textile Strukturen werden in grossem Ausmass als medizinische Implantate eingesetzt, um Weich- und Hartgewebe zu unterstützen oder zu ersetzen. Im Tissue Engineering gewinnen sie an Bedeutung als scaffolds, um biologische Gewebe in vitro zu züchten für anschliessende Implantation oder extrakorporale Anwendungen. Textilien sind gewöhnlich anisotrope zweidimensionale Strukturen mit hoher Steifigkeit in der Ebene und geringer Biegesteifigkeit. Durch eine Vielzahl textiler Prozesse und durch entsprechende Wahl des Fasermaterials ist es möglich, Oberfläche, Porosität und mechanische Anisotropie in hohem Masse zu variieren. Wegen ihrer einzigartigen strukturellen und mechanischen Eigenschaften können faserbasierte Materialien in weitem Masse biologischem Gewebe nachgeahmt werden [1]. Gesticke erweitern das Feld von technischen und besonders medizinischen Textilien, denn sie vereinen sehr hohe strukturelle Variabilität mit der Möglichkeit, mechanische Eigenschaften in einem grossen Bereich einzustellen, um so die mechanischen Anforderungen des Empfängergewebes zu erfüllen (Abb. 42.1).

  16. Zahlen und Rechenvorgänge auf unterschiedlichen Abstraktionsniveaus

    NASA Astrophysics Data System (ADS)

    Rödler, Klaus

    "Das Verständnis geht langsam vor sich!" Diesen wichtigen Satz hörte ich bei einem Vortrag von Martin Lowsky. Auf die hier behandelte Fragestellung übertragen heißt das: Was eine Zahl ist und wie ich sie im Rechenvorgang einsetzen und interpretieren kann, das erschließt sich erst allmählich. Die Zahl des Rechenanfängers ist nicht dieselbe wie die des kompetenten Rechners und es ist nicht die Zahl des Lehrers oder der Lehrerin. Die Zahlen sind nur auf der Oberfläche der Worte und Zeichen gleich. Im Innern, im Verständnis, sind sie völlig verschieden! Ich glaube, dass die Missachtung dieser Divergenz dazu führt, dass manche Kinder in für den Lehrer und Lehrerin nicht nachvollziehbaren Routinen stecken bleiben, einfachste Informationen nicht wirklich integrieren. Die auf beiden Seiten wachsende Verunsicherung durch die nicht erkannte und daher nicht kommunizierbare Diskrepanz im inneren Zahlkonzept stört den allmählichen Aufbau strukturierter Zahlvorstellungen.

  17. S1-Leitlinie zur UV-Phototherapie und Photochemotherapie.

    PubMed

    Herzinger, Thomas; Berneburg, Mark; Ghoreschi, Kamran; Gollnick, Harald; Hölzle, Erhard; Hönigsmann, Herbert; Lehmann, Percy; Peters, Thorsten; Röcken, Martin; Scharffetter-Kochanek, Karin; Schwarz, Thomas; Simon, Jan; Tanew, Adrian; Weichenthal, Michael

    2016-08-01

    Die heilsame Wirkung des Sonnenlichts war teilweise schon im Altertum bekannt und fand in der zweiten Hälfte des 19. Jahrhunderts wieder zunehmend Beachtung. Den Beginn der modernen Phototherapien markiert die Entwicklung einer Apparatur zur ultravioletten Bestrahlung der Hauttuberkulose durch Finnsen zu Beginn des zwanzigsten Jahrhunderts. Zur Therapie von Hauterkrankungen finden beinahe ausschließlich die spektralen Bereiche unterhalb des sichtbaren Lichtes (ultraviolett) Anwendung. Seit den 1970er Jahren stehen zunehmend leistungsfähige künstliche Strahlenquellen bereit für die Therapie mit UVB, UVA und die Kombination von UVA mit Photosensibilisatoren (Photochemotherapie). Hohe strukturelle und prozedurale Qualitätsstandards sind unabdingbare Voraussetzung für die Durchführung einer gleichermaßen wirkungsvollen wie auch sicheren Phototherapie. Die Leitlinie formuliert den aktuellen Konsens führender Experten auf dem Gebiet der Phototherapie in Bezug auf die Indikationen für die jeweiligen Therapieverfahren, deren Gegenanzeigen und Nebenwirkungen und insbesondere für die Wahl der korrekten Dosis zu Beginn und im Verlauf einer Therapie sowie das Management von Nebenwirkungen. PMID:27509439

  18. VDI-Richtlinien - mit Technischen Regeln Wirtschaftlichkeit erhöhen und Standards setzen

    NASA Astrophysics Data System (ADS)

    Mandelartz, Johannes

    Der Verein Deutscher Ingenieure e.V. (VDI) ist ein gemeinnütziger, wirtschaftlich und politisch unabhängiger, technisch-wissenschaftlicher Verein von Ingenieuren und Naturwissenschaftlern. Mit über 137 000 persönlich zugeordneten Mitgliedern ist er eine der größten Ingenieur-Vereinigungen Europas und gilt in Deutschland als führender Sprecher der Technik und der Ingenieure. 1856 gegründet, hat er viele für die Technik wesentliche Entwicklungen in Gang gesetzt, so im Bereich der technischen Überwachung, der technischen Regelsetzung und Normung, der Arbeitsstudien, im gewerblichen Rechtsschutz und im Patentwesen. Seit seiner Gründung sieht es der VDI als seine Aufgabe, "das Zusammenwirken aller geistiger Kräfte der Technik im Bewusstsein ethischer Verantwortung zu fördern“ und die Lebensmöglichkeiten aller Menschen durch Entwicklung und sinnvoller Anwendung technischer Mittel zu verbessern.

  19. Spectroscopic Classifications of Optical Transients with SOAR

    NASA Astrophysics Data System (ADS)

    Foley, R. J.; Hounsell, R. A.; Downing, S.; Pan, Y.-C.; Scolnic, D.; Jha, S. W.; Rest, A.; Smith, K. W.; Wright, D.; Smartt, S. J.; Huber, M.; Chambers, K. C.; Flewelling, H.; Willman, M.; Primak, N.; Schultz, A.; Gibson, B.; Magnier, E.; Waters, C.; Tonry, J.; Wainscoat, R. J.

    2015-07-01

    We report the following classifications of optical transients from spectroscopic observations with the Goodman spectrograph (wavelength range 3100 - 7100) on the Southern Astrophysical Research (SOAR) telescope.

  20. A Case of Transient Global Amnesia

    PubMed Central

    Mccroskey, Aidan L.; Deyerle, Branden A.

    2016-01-01

    Transient global amnesia is a clinical syndrome characterized by the sudden onset of anterograde amnesia, accompanied by repetitive questioning, sometimes with a retrograde component, lasting up to 24 hours, without compromise of other neurologic function. Neuroimaging after an acutetransient global amnesia event often shows transient perturbation of specific hippocampal circuits that are involved in memory processing. Critical clinical distinctions, such as between transient global amnesia and other forms of transient amnesic episodes, as well as important clues to the underlying pathophysiologies are herein reviewed. Finally, we discuss the role of hippocampal insufficiency in the neurobiology of delusions. PMID:27354927

  1. Transients with the Fermi GBM

    NASA Astrophysics Data System (ADS)

    Hui, Michelle; Fermi GBM Team

    2016-03-01

    The Fermi Gamma-ray Burst Monitor (GBM) is an all-sky monitoring instrument sensitive to energies from 8 keV to 40 MeV. Its primary science objective is observing gamma-ray bursts (GRBs) in support of the Large Area Telescope, which are both part of the Fermi Gamma-ray Space Telescope. Over the past 7 years of operation, the GBM has detected over 240 GRBs per year and provided timely GCN notices for follow-up observations. In addition to GRBs, Galactic transients, solar flares, and terrestrial gamma-ray flashes have also been observed. With several instruments coming online recently, such as the gravitational wave detectors Advanced LIGO/Virgo and the very high energy surveying instrument HAWC, now is an opportune time for multi-messenger collaboration in counterpart search of gravitational waves and GRBs.

  2. Transient Dendritic Solidification Experiment (TDSE)

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The Transient Dendritic Solidification Expepriment (TDSE) is being developed as a candidate for flight aboard the International Space Station. TDSE will study the growth of dendrites (treelike crystalline structures) in a transparent material (succinonitrile or SCN) that mimics the behavior of widely used iron-based metals. Basic work by three Space Shuttle missions of the Isothermal Dendritic Growth Expepriment (IDGE) is yielding new insights into virtually all industrially relevant metal and alloy forming operations. The TDSE is similar to IDGE, but will maintain a constant temperature while varying pressure on the dendrites. Shown here is an exploded view of major elements of TDSE. A similar view is available with labels. The principal investigator is Matthew Koss of College of the Holy Cross in Worcester, MA. Photo credit: NASA/Marshall Space Flight Center (MSFC)

  3. Transient Dendritic Solidification Experiment (TDSE)

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The Transient Dendritic Solidification Experiment (TDSE) is being developed as a candidate for flight aboard the International Space Station. TDSE will study the growth of dendrites (treelike crystalline structures) in a transparent material (succinonitrile or SCN) that mimics the behavior or widely used iron-based metals. Basic work by three Space Shuttle missions of the Isothermal Dendritic Growth Experiment (IDGE) is yielding new insights into virtually all industrially relevant metal and alloy forming operations. The TDSE is similar to IDGE, but will maintain a constant temperature while varying pressure on the dendrites. Shown here is an exploded view of major elements of the TDSE. A similar view is availble without labels. The principal investigator is Matthew Koss of College of the Holy Cross in Worcester, MA. Photo credit: NASA/Marshall Space Flight Center (MSFC)

  4. Adaptation to transient postural perturbations

    NASA Technical Reports Server (NTRS)

    Andres, Robert O.

    1992-01-01

    This research was first proposed in May, 1986, to focus on some of the problems encountered in the analysis of postural responses gathered from crewmembers. The ultimate driving force behind this line of research was the desire to treat, predict, or explain 'Space Adaptation Syndrome' (SAS) and hence circumvent any adverse effects of space motion sickness on crewmember performance. The aim of this project was to develop an easily implemented analysis of the transient responses to platform translation that can be elicited with a protocol designed to force sensorimotor reorganization, utilizing statistically reliable criterion measures. This report will present: (1) a summary of the activity that took place in each of the three funded years of the project; (2) discussion of experimental results and their implications for future research; and (3) a list of presentations and publications resulting from this project.

  5. Regulatory Analysis of Reactivity Transients

    SciTech Connect

    Beyer, Carl E.; Clifford, Paul M.; Geelhood, Kenneth J.; Voglewede, John C.

    2009-08-01

    This paper will describe modifications made to the FRAPCON-3 and FRAPTRAN fuel performance codes and models that impact reactivity initiated accident (RIA) analyses. The modified models include an upper bound empirical and best estimate release models for fast transients, and a revised fuel failure model that accounts for ductile and brittle failure. Because experimental data exists for discrete test conditions, the codes and models are used to interpolate and to some extent, to extrapolate these test conditions. An upper bound empirical model for release is used to establish new recommended release fractions for long-lived and short lived (radioactive) isotopes for RIA events in Regulatory Guide 1.183. A best estimate release model is used in FRAPTRAN 1.4 based on grain boundary gas concentrations from FRAPCON-3.4 to predict release for RIA events. Code and model predictions will be compared to failure and release data from RIA tests to demonstrate accuracy.

  6. X33 Transient Liftoff Analysis

    NASA Technical Reports Server (NTRS)

    Peck, Jeff; Brunty, Joseph

    2000-01-01

    The successful design of a launch vehicle requires the careful characterization of the various loads the structure will experience over its lifetime. Many of the most demanding load environments occur during the launch/ascent phase of a mission, typically defined as the point of engine start through engine cut off. One of the critical events during the launch phase is the liftoff event. This event imparts high loads on the vehicle due to transient events such as thrust build-up and vehicle release. This paper describes the theory and procedures used to calculate structural loads due to the liftoff event for the Lockheed-Martin X33 technology demonstrator vehicle. These procedures were developed at NASA's Marshall Space Flight Center and verified previously on other advanced launch system concepts and the Space Shuttle system.

  7. Nicolaus Copernicus Gesamtausgabe. Band VI/1. Documenta Copernicana: Briefe (Texte und Übersetzungen).

    NASA Astrophysics Data System (ADS)

    Kühne, A.

    Im Auftrage der Kommission für die Copernicus-Gesamtausgabe, herausgegeben von H. M. Nobis und M. Folkerts. Band VI/1 wurde bearbeitet von A. Kühne unter Mitarbeit von F. Boockmann und S. Kirschner und Verwendung der Vorarbeiten von H. M. Nobis.

  8. Transient global amnesia: an extensive case report.

    PubMed Central

    Gordon, B; Marin, O S

    1979-01-01

    A case of transient global amnesia was studied in detail. Of note was a temporally extensive, although quite patchy, retrograde amnesia during the event for information recallable at other times. While a consolidation block can explain the anterograde amnesia in transient global amnesia, the profound retrograde amnesia requires an additional block in the retrieval of old, established memories. PMID:469566

  9. Transient thermal stress recovery for structural models

    NASA Technical Reports Server (NTRS)

    Walls, William

    1992-01-01

    A method for computing transient thermal stress vectors from temperature vectors is described. The three step procedure involves the use of NASTRAN to generate an influence coefficient matrix which relates temperatures to stresses in the structural model. The transient thermal stresses are then recovered and sorted for maximum and minimum values. Verification data for the procedure is also provided.

  10. Stability Test for Transient-Temperature Calculations

    NASA Technical Reports Server (NTRS)

    Campbell, W.

    1984-01-01

    Graphical test helps assure numerical stability of calculations of transient temperature or diffusion in composite medium. Rectangular grid forms basis of two-dimensional finite-difference model for heat conduction or other diffusion like phenomena. Model enables calculation of transient heat transfer among up to four different materials that meet at grid point.

  11. Ökophysik: Plaudereien über das Leben auf dem Land, im Wasser und in der Luft

    NASA Astrophysics Data System (ADS)

    Nachtigall, W.

    Prof. em. Dr. rer. nat. Werner Nachtigall, geb. 1934, war als Zoophysiologe und Biophysiker Leiter des Zoologischen Instituts der Universität des Saarlandes in Saarbrücken. In Forschung und Ausbildung hat er sich insbesondere mit Aspekten der Technischen Biologie und Bionik befasst und mit seinen Forschergruppen viele Basisdaten insbesondere zur Ökologie, Physiologie und Physik des Fliegens und Schwimmens aber auch zur Stabilität beispielsweise der Gräser erarbeitet. Lebewesen überraschen immer wieder durch ihre "Biodiversität", ihre hochspezifischen Ausgestaltungen und Anpassungen.

  12. Transient repression of the lac operon.

    PubMed

    Tyler, B; Loomis, W F; Magasanik, B

    1967-12-01

    Severe transient repression of constitutive or induced beta-galactosidase synthesis occurs upon the addition of glucose to cells of Escherichia coli growing on glycerol, succinic acid, or lactic acid. Only mutants particularily well adapted to growth on glucose exhibit this phenomenon when transferred to a glucose-containing medium. No change in ribonucleic acid (RNA) metabolism was observed during transient repression. We could show that transient repression is pleiotropic, affecting all products of the lac operon. It occurs in a mutant insensitive to catabolite repression. It is established much more rapidly than catabolite repression, and is elicited by glucose analogues that are phosphorylated but not further catabolized by the cell. Thus, transient repression is not a consequence of the exclusion of inducer from the cell, does not require catabolism of the added compound, and does not involve a gross change in RNA metabolism. We conclude that transient repression is distinct from catabolite repression. PMID:4864411

  13. Synchronizing noisy nonidentical oscillators by transient uncoupling

    NASA Astrophysics Data System (ADS)

    Tandon, Aditya; Schröder, Malte; Mannattil, Manu; Timme, Marc; Chakraborty, Sagar

    2016-09-01

    Synchronization is the process of achieving identical dynamics among coupled identical units. If the units are different from each other, their dynamics cannot become identical; yet, after transients, there may emerge a functional relationship between them—a phenomenon termed "generalized synchronization." Here, we show that the concept of transient uncoupling, recently introduced for synchronizing identical units, also supports generalized synchronization among nonidentical chaotic units. Generalized synchronization can be achieved by transient uncoupling even when it is impossible by regular coupling. We furthermore demonstrate that transient uncoupling stabilizes synchronization in the presence of common noise. Transient uncoupling works best if the units stay uncoupled whenever the driven orbit visits regions that are locally diverging in its phase space. Thus, to select a favorable uncoupling region, we propose an intuitive method that measures the local divergence at the phase points of the driven unit's trajectory by linearizing the flow and subsequently suppresses the divergence by uncoupling.

  14. Transient Eddies in the UCLA GCM

    NASA Technical Reports Server (NTRS)

    White, G. H.

    1985-01-01

    The simulation of transient eddies in the nine level UCLA general circulation model (GCM) was examined and compared to observations, with emphasis on the Northern Hemisphere winter. Qualitatively, the UCLA GCM reproduces many features of the observed circulation and the relationship between the time mean flow and transient eddies; however, the magnitudes of transient eddies in the UCLA GCM, particularly at frequencies lower than those associated with baroclinic instability, appear to be much less than those observed. The pattern of low level transient eddy heat fluxes were similar to observations and acted to dissipate the low level seasonal mean temperature field. The simulated transient eddy kinetic energy at 300 mb is given for eddies of all time scales shorter than a season.

  15. Galactic transients from the OGLE survey

    NASA Astrophysics Data System (ADS)

    Mroz, Przemek

    2016-07-01

    For many years, there were not any systematic, large-scale surveys for transients in the Milky Way and the Magellanic Clouds. This gap is being filled by discoveries from the OGLE survey, which has been regularly monitoring the densest sky regions (the Galactic bulge and disk, the Magellanic System) for over twenty years. The OGLE collection of Galactic transients contains several dozen classical novae and over a thousand other cataclysmic variables. I will tell how to select transients from billions of sources observed by the OGLE every night. I will show how the properties of classical novae depend on the underlying stellar population (and the star formation history). I will also discuss the preliminary results of the search for transients in the Milky Way disk from the OGLE-IV Galaxy Variability Survey. Finally, I will show some transients of yet unknown origin and present the OGLE-IV real time monitoring systems.

  16. Informationsqualität - Definitionen, Dimensionen und Begriffe

    NASA Astrophysics Data System (ADS)

    Rohweder, Jan Philipp; Kasten, Gerhard; Malzahn, Dirk; Piro, Andrea; Schmid, Joachim

    Die Verbesserung und Sicherstellung der Informationsqualität wird in immer mehr Unternehmen als eigenständige Managementaufgabe von großer Wichtigkeit begriffen. IQ-Management ist ein elementarer Baustein in Systemintegrationsprojekten. Aber auch in bestehenden Prozessen mit heterogenen Datenquellen und Informationsnutzern ist eine hohe Informationsqualität die Grundvoraussetzung für funktionierende betriebliche Abläufe. Voraussetzung für ein effektives IQ-Management ist die Bewertung der Informationsqualität [Lee et al. 2006, S. 13 und S. 27]. In vielen Unternehmen ist Informationsqualität nur ein gefühlter Wert. Die meisten Anwender bringen ein gewisses Misstrauen den Daten gegenüber zum Ausdruck, dies jedoch ohne genaue Angabe der Fehlerart und -häufigkeit. Nicht selten werden kostspielige Projekte angestoßen, um die Informationsqualität zu verbessern, ohne sich vor einer IQ-Maßnahme durch eine Analyse ein genaues Bild über die tatsächlichen Probleme zu verschaffen. Nur auf der Basis einer umfassenden Bewertung der Informationsqualität können die notwendigen Ressourcenentscheidungen herbeigeführt, Ziele gesetzt und der Erfolg des IQ-Management beurteilt werden.

  17. Herschel und die Zukunft der Fern-Infrarot-Astronomie

    NASA Astrophysics Data System (ADS)

    Linz, Hendrik

    2015-06-01

    Schon lange ist die beobachtende Astronomie den engen Grenzen des optisch Sichbaren entwachsen und hat fast alle Bereiche des elektromagnetischen Spektrums für sich dienstbar gemacht. Im sogenannten nahen und mittleren Infrarot (Wellenlängen zwischen 1-30 μm) sowie im Millimeter- und Radio-Regime (Wellenlängen zwischen 1 mm und 10 m) ist die Erdatmosphäre relativ gut durchlässig für elektromagnetische Signale oder hat zumindest eine Vielzahl von spektral begrenzten Transmissionsfenstern, die astronomische Beobachtungen zumindest von höheren Bergen aus möglich machen. Allerdings ist das sogenannte Ferne Infrarot (FIR, 30-300 μm Wellenlänge) von der Erde aus fast völlig unzugänglich für astronomische Beobachtungen. Selbst für die besten Beobachtungsplätze der Erde bleibt die atmosphärische Transmission durch die immense Wasserdampf- Absorption auf ein absolutes Minimum beschränkt. Jedoch erlaubt uns das FIR Zugang zu Informationen, die sehr nützlich sind für die astrophysikalische Forschung und komplementär zu anderen Wellenlängen-Bereichen.

  18. Messen, Kalibrieren, Eichen in der Radiologie: Prinzipien und Praxis

    NASA Astrophysics Data System (ADS)

    Wagner, Siegfried R.

    Nach einleitender Erläuterung der unterschiedlichen Meßbedingungen in der Strahlentherapie und im Strahlenschutz werden die metrologischen Probleme am Beispiel der Größenkategorie Äquivalentdosis diskutiert. Als spezielle Größen werden effektive Äquivalentdosis und Umgebungs-Äquivalentdosis eingeführt. Es wird gezeigt, wie richtiges Messen durch ein konsistentes System von Bauartanforderungen an Meßgeräte, durch Kalibrieren und durch Eichen gewährleistet werden kann. Die Bedeutung von Meßunsicherheiten und Fehlergrenzen wird erläutert und ihre Auswirkung auf die Interpretation von Meßergebnissen behandelt.Translated AbstractMeasurements, Calibration, Verification in Radiology: Principles and PracticeThe different measuring conditions in radiotherapy and in radiation protection are discussed in the introduction. Then, the metrological problems are discussed exemplarily with the dose equivalent as a category of quantity. Effective dose equivalent and ambient dose equivalent are introduced as special quantities. It is demonstrated, how correct measurements can be secured by a consistent system of instrument pattern requirements, by calibration and verification. The importance of uncertainties of measurements and of error limits is illustrated and their influence on the interpretation of the results of measurements is treated.

  19. Current status of the Explosive Transient Camera. [automated sky survey instument sensitive to optical transients

    NASA Technical Reports Server (NTRS)

    Vanderspek, Roland; Doty, John P.; Ricker, George R.

    1992-01-01

    The current configuration and performance of the Explosive Transient Camera (ETC), a wide-field sky monitor capable of detecting short-timescale optical transients, are briefly reviewed, as are plans for future improvements. The primary objective of the ETC is to detect an optical transient that is spatially and temporally coincident with a gamma-ray burster. However, the ETC is sensitive to all sources of short-timescale optical transients and will conduct a systematic survey of the night sky for all optical transients. Results of preliminary observations of the night sky conducted since January 1991 are summarized, and long-term variability searches with the ETC are discussed.

  20. Transient shocks beyond the heliopause

    SciTech Connect

    Fermo, R. L.; Pogorelov, N. V.; Burlaga, L. F.

    2015-09-30

    The heliopause is a rich, dynamic surface affected by the time-dependent solar wind. Stream interactions due to coronal mass ejections (CMEs), corotating interaction regions (CIRs), and other transient phenomena are known to merge producing global merged interaction regions (GMIRs). Numerical simulations of the solar wind interaction with the local interstellar medium (LISM) show that GMIRs, as well other time-dependent structures in the solar wind, may produce compression/rarefaction waves and shocks in the LISM behind the heliopause. These shocks may initiate wave activity observed by the Voyager spacecraft. The magnetometer onboard Voyager 1 indeed observed a few structures that may be interpreted as shocks. We present numerical simulations of such shocks in the year of 2000, when both Voyager spacecraft were in the supersonic solar wind region, and in 2012, when Voyager 1 observed traveling shocks. In the former case, Voyager observations themselves provide time- dependent boundary conditions in the solar wind. In the latter case, we use OMNI data at 1 AU to analyze the plasma and magnetic field behavior after Voyager 1 crossed the heliospheric boundary. Numerical results are compared with spacecraft observations.

  1. Transient shocks beyond the heliopause

    DOE PAGESBeta

    Fermo, R. L.; Pogorelov, N. V.; Burlaga, L. F.

    2015-09-30

    The heliopause is a rich, dynamic surface affected by the time-dependent solar wind. Stream interactions due to coronal mass ejections (CMEs), corotating interaction regions (CIRs), and other transient phenomena are known to merge producing global merged interaction regions (GMIRs). Numerical simulations of the solar wind interaction with the local interstellar medium (LISM) show that GMIRs, as well other time-dependent structures in the solar wind, may produce compression/rarefaction waves and shocks in the LISM behind the heliopause. These shocks may initiate wave activity observed by the Voyager spacecraft. The magnetometer onboard Voyager 1 indeed observed a few structures that may bemore » interpreted as shocks. We present numerical simulations of such shocks in the year of 2000, when both Voyager spacecraft were in the supersonic solar wind region, and in 2012, when Voyager 1 observed traveling shocks. In the former case, Voyager observations themselves provide time- dependent boundary conditions in the solar wind. In the latter case, we use OMNI data at 1 AU to analyze the plasma and magnetic field behavior after Voyager 1 crossed the heliospheric boundary. Numerical results are compared with spacecraft observations.« less

  2. POET: POlarimeters for Energetic Transients

    NASA Technical Reports Server (NTRS)

    Hill, J. E.; McConnell, M. L.; Bloser, P.; Legere, J.; Macri, J.; Ryan, J.; Barthelmy, S.; Angelini, L.; Sakamoto, T.; Black, J. K.; Hartmann, D. H.; Kaaret, P.; Zhang, B.; Ioka, K.; Nakamura, T.; Toma, K.; Yamazaki, R.; Wu, X.

    2008-01-01

    POET (Polarimeters for Energetic Transients) is a Small Explorer mission concept proposed to NASA in January 2008. The principal scientific goal of POET is to measure GRB polarization between 2 and 500 keV. The payload consists of two wide FoV instruments: a Low Energy Polarimeter (LEP) capable of polarization measurements in the energy range from 2-15 keV and a high energy polarimeter (Gamma-Ray Polarimeter Experiment - GRAPE) that will measure polarization in the 60-500 keV energy range. Spectra will be measured from 2 keV up to 1 MeV. The POET spacecraft provides a zenith-pointed platform for maximizing the exposure to deep space. Spacecraft rotation will provide a means of effectively dealing with systematics in the polarization response. POET will provide sufficient sensitivity and sky coverage to measure statistically significant polarization for up to 100 GRBs in a two-year mission. Polarization data will also be obtained for solar flares, pulsars and other sources of astronomical interest.

  3. Transient liquid phase ceramic bonding

    DOEpatents

    Glaeser, Andreas M.

    1994-01-01

    Ceramics are joined to themselves or to metals using a transient liquid phase method employing three layers, one of which is a refractory metal, ceramic or alloy. The refractory layer is placed between two metal layers, each of which has a lower melting point than the refractory layer. The three layers are pressed between the two articles to be bonded to form an assembly. The assembly is heated to a bonding temperature at which the refractory layer remains solid, but the two metal layers melt to form a liquid. The refractory layer reacts with the surrounding liquid and a single solid bonding layer is eventually formed. The layers may be designed to react completely with each other and form refractory intermetallic bonding layers. Impurities incorporated into the refractory metal may react with the metal layers to form refractory compounds. Another method for joining ceramic articles employs a ceramic interlayer sandwiched between two metal layers. In alternative embodiments, the metal layers may include sublayers. A method is also provided for joining two ceramic articles using a single interlayer. An alternate bonding method provides a refractory-metal oxide interlayer placed adjacent to a strong oxide former. Aluminum or aluminum alloys are joined together using metal interlayers.

  4. Monitoring of Transient Lunar Phenomena

    NASA Astrophysics Data System (ADS)

    Barker, Timothy; Farber, Ryan; Ahrendts, Gary

    2014-06-01

    Transient Lunar Phenomena (TLP’s) are described as short-lived changes in the brightness of areas on the face of the Moon. TLP research is characterized by the inability to substantiate, reproduce, and verify findings. Our current research includes the analysis of lunar images taken with two Santa Barbara Instrument Group (SBIG) ST8-E CCD cameras mounted on two 0.36m Celestron telescopes. On one telescope, we are using a sodium filter, and on the other an H-alpha filter, imaging approximately one-third of the lunar surface. We are focusing on two regions: Hyginus and Ina. Ina is of particular interest because it shows evidence of recent activity (Schultz, P., Staid, M., Pieters, C. Nature, Volume 444, Issue 7116, pp. 184-186, 2006). A total of over 50,000 images have been obtained over approximately 35 nights and visually analyzed to search for changes. As of March, 2014, no evidence of TLPs has been found. We are currently developing a Matlab program to do image analysis to detect TLPs that might not be apparent by visual inspection alone.

  5. Transient shocks beyond the heliopause

    NASA Astrophysics Data System (ADS)

    Fermo, R. L.; Pogorelov, N. V.; Burlaga, L. F.

    2015-09-01

    The heliopause is a rich, dynamic surface affected by the time-dependent solar wind. Stream interactions due to coronal mass ejections (CMEs), corotating interaction regions (CIRs), and other transient phenomena are known to merge producing global merged interaction regions (GMIRs). Numerical simulations of the solar wind interaction with the local interstellar medium (LISM) show that GMIRs, as well other time-dependent structures in the solar wind, may produce compression/rarefaction waves and shocks in the LISM behind the heliopause. These shocks may initiate wave activity observed by the Voyager spacecraft. The magnetometer onboard Voyager 1 indeed observed a few structures that may be interpreted as shocks. We present numerical simulations of such shocks in the year of 2000, when both Voyager spacecraft were in the supersonic solar wind region, and in 2012, when Voyager 1 observed traveling shocks. In the former case, Voyager observations themselves provide time- dependent boundary conditions in the solar wind. In the latter case, we use OMNI data at 1 AU to analyze the plasma and magnetic field behavior after Voyager 1 crossed the heliospheric boundary. Numerical results are compared with spacecraft observations.

  6. IQM-Reifegradmodell für die Bewertung und Verbesserung des Information Lifecycle Management Prozesses

    NASA Astrophysics Data System (ADS)

    Baškarada, Saša; Gebauer, Marcus; Koronios, Andy; Gao, Jing

    Heutige Organisationen produzieren und speichern mehr Informationen als je zuvor. Der resultierende Informationsüberfluss, zusammen mit einem Mangel an Qualitätssicherung für das Information Lifecycle Management, führt zu einem unsicheren Status der Informationsqualität in vielen Organisationen. Weiterhin hat sich herausgestellt, dass das Bewerten, Verbessern und Steuern der Informationsqualität ein offenkundig schwieriges Unterfangen ist. Dieses Kapitel stellt ein Modell zur Bewertung und Verbesserung der Information Quality Management Capability Maturity (IQM-Reifegrad) vor. Es wird ein Satz von Kriterien vorgestellt, der aus Literaturrecherche und Fallstudien abgeleitet wurde. Die Reifegradindikatoren werden validiert und in einem mehrstufigen Reifegradmodell durch eine Delphi-Studie gruppiert. Das abgeleitete IQM-Reifegradmodell hilft Organisationen ihre bestehenden Praktiken im IQM zu bewerten und potentielle Lücken und Verbesserungsstrategien zu ermitteln.

  7. Endoskopie, minimal invasive chirurgische und navigierte Verfahren in der Urologie

    NASA Astrophysics Data System (ADS)

    Grosse, Joachim; von Walter, Matthias; Jakse, Gerhard

    Betrachtet man die letzten 100 Jahre der Urologie in Deutschland seit Gründung ihrer Fachgesellschaft 1906 in Stuttgart, so sind sicherlich die letzten 25 Jahre von umfassenden Entwicklungen mit z. T. vollständigen Umwälzungen bisheriger Therapien und Methoden auf urologischen Fachgebiet gekennzeichnet. In erster Linie handelte es sich dabei um minimal invasive endoskopische Techniken wie perkutane Nierenchirurgie, Ureterorenoskopie, videoendoskopisch unterstütze transurethrale Elektroresektionen der Prostata und von Blasentumore sowie die Laparoskopie. Sie führten zu besseren operativen Ergebnissen und einer deutlichen Senkung der Morbidität der entsprechenden Behandlung urologischer Krankheitsbilder, mit der Konsequenz, dass einige bisher als Standard gültige offene Operationsverfahren abgelöst wurden.

  8. Apparatus Characterizes Transient Voltages in Real Time

    NASA Technical Reports Server (NTRS)

    Medelius, Pedro

    2005-01-01

    The figure shows a prototype of a relatively inexpensive electronic monitoring apparatus that measures and records selected parameters of lightning-induced transient voltages on communication and power cables. The selected parameters, listed below, are those most relevant to the ability of lightning-induced transients to damage electronic equipment. This apparatus bridges a gap between some traditional transient-voltage recorders that record complete waveforms and other traditional transient-voltage recorders that record only peak values: By recording the most relevant parameters and only those parameters this apparatus yields more useful information than does a traditional peak-value (only) recorder while imposing much smaller data-storage and data-transmission burdens than does a traditional complete-waveform recorder. Also, relative to a complete-waveform recorder, this apparatus is more reliable and can be built at lower cost because it contains fewer electronic components. The transients generated by sources other than lightning tend to have frequency components well below 1 MHz. Most commercial transient recorders can detect and record such transients, but cannot respond rapidly enough for recording lightning-induced transient voltage peaks, which can rise from 10 to 90 percent of maximum amplitude in a fraction of a microsecond. Moreover, commercial transient recorders cannot rearm themselves rapidly enough to respond to the multiple transients that occur within milliseconds of each other on some lightning strikes. One transient recorder, designed for Kennedy Space Center earlier [ Fast Transient-Voltage Recorder (KSC- 11991), NASA Tech Briefs, Vol. 23, No. 10, page 6a (October 1999)], is capable of sampling transient voltages at peak values up to 50 V in four channels at a rate of 20 MHz. That recorder contains a trigger circuit that continuously compares the amplitudes of the signals on four channels to a preset triggering threshold. When a trigger signal

  9. Characterizing SI Engine Transient Fuel Consumption in ALPHA

    EPA Science Inventory

    Examine typical transient engine operation encountered over the EPA's vehicle and engine testing drive cycles to characterize that transient fuel usage, and then describe the changes made to ALPHA to better model transient engine operation.

  10. Transients in a circulating fluidized bed boiler

    NASA Astrophysics Data System (ADS)

    Baskakov, A. P.; Munts, V. A.; Pavlyuk, E. Yu.

    2013-11-01

    Transients in a circulating fluidized bed boiler firing biomass are considered. An attempt is made to describe transients with the use of concepts applied in the automatic control theory. The parameters calculated from an analysis of unsteady heat balance equations are compared with the experimental data obtained in the 12-MW boiler of the Chalmers University of Technology. It is demonstrated that these equations describe the transient modes of operation with good accuracy. Dependences for calculating the time constants of unsteady processes are obtained.

  11. Tracking Steady Light Sources Amid Luminous Transients

    NASA Technical Reports Server (NTRS)

    Kissh, Frank; Fowski, Walter; Miklus, Kenneth; Abreu, Rene; Bolin, Kenneth; Flynn, David

    1994-01-01

    The Transient Event Rejection for Acquisition and Tracking (TERAT) algorithm governs operation of image-data-acquisition and -processing system. TERAT processes digitized image data to acquire (that is, identify) candidate steady source of light, validate candidate source, and track validated source, all in presence of real or apparent luminous transients represented in image data. Source of light tracked could be star or distant luminous beacon. Transients caused by impacts of ionizing radiation on imaging array of photodetectors or by unsteady light sources not meant to be tracked. TERAT functions with limited data-processing resources. TERAT algorithm currently operational on NASA's TOPEX mission.

  12. Transient studies of capillary-induced flow

    NASA Technical Reports Server (NTRS)

    Reagan, M. K.; Bowman, W. J.

    1993-01-01

    This paper presents the numerical and experimental results of a study performed on the transient rise of fluid in a capillary tube. The capillary tube problem provides an excellent mechanism from which to launch an investigation into the transient flow of a fluid in a porous wick structure where capillary forces must balance both adverse gravitational effects and frictional losses. For the study, a capillary tube, initially charged with a small volume of water, was lowered into a pool of water. The behavior of the column of fluid during the transient that followed as more water entered the tube from the pool was both numerically and experimentally studied.

  13. Transient epileptic amnesia: a concise review.

    PubMed

    Asadi-Pooya, Ali A

    2014-02-01

    Transient epileptic amnesia (TEA) is a distinctive syndrome and comprises episodic transient amnesia with an epileptic basis, without impairment of other aspects of cognitive function. Additional interictal memory deficits are common in TEA. An epileptic origin, after other etiologies have been excluded, should be considered and carefully investigated in patients complaining of isolated memory disturbances, particularly with recurrent short-lasting amnesic attacks. In all suspected cases of epilepsy, a detailed clinical history is of paramount importance, but ancillary tests including EEG and MRI could be very helpful. Transient epileptic amnesia is typically a benign and treatable condition. Future studies should investigate the exact mechanism(s) of this unique syndrome.

  14. Fermi-LAT Observations of Galactic Transients

    NASA Technical Reports Server (NTRS)

    Hays, Elizabeth

    2011-01-01

    This slide presentation reviews the observations of Galactic transients by the Large Area Telescope (LAT) on the Fermi Gamma Ray Space Telescope. The LAT is producing spectacular results for the GeV transient sky, some of which are shown and reviewed. Some of the results in the GeV range that are discussed in this presentation are: (1) New blazars and unidentified transients (2) the jet of the Cygnus X-3 microquasar (3) gamma rays from V407 Cygni nova (4) Fast high-energy gamma-ray flares from the Crab Nebula

  15. Transient period process control for continuous manufacturing

    SciTech Connect

    Nembhard, H.B.; Birge, J.R.

    1994-12-31

    We develop a multiple objective nonlinear control model to optimize decision variables for correlated process characteristics during a transient phase. Given a continuous manufacturing process we show how to use the model to improve operations from startup to the end of the transient period (when steady-state is reached). We also show how to identify the end of the transient period and compare performance using the model during steady-state to traditional SPC techniques that assume the process is in statistical control.

  16. Transient resonances in the inspirals

    NASA Astrophysics Data System (ADS)

    Hinderer, Tanja; Flanagan, Eanna

    2009-05-01

    We show that the two body problem in general relativity in the highly relativistic regime has a qualitatively new feature: the occurence of transient resonances. The resonances occur when the ratio of polar and radial orbital frequencies, which is slowly evolving under the influence of gravitational radiation reaction, passes through a low order rational number. The resonances make the orbit more sensitive to changes in the initial data (though not quite chaotic), and are genuine non-perturbative effects that are not seen at any order in the standard post-Newtonian expansion used for two body systems at large separation. Our results directly apply to an important potential source of gravitational waves, namely the gradual inspiral of compact objects into much more massive black holes. Exploiting observations of these gravitational waves to map the spacetime geometry of black holes is contingent upon accurate theoretical models (templates) of the binary dynamics. At present, only the leading order in the mass ratio gravitational waveforms can be computed. Corrections to the waveform's phase due to resonance effects scale as the square root of the inverse of the mass ratio and are characterized by sudden jumps in the time derivatives of the phase. We numerically estimate the net size of these corrections and find indications that the phase error is of order a few cycles for mass ratios ˜10^- 3 but will be significant (of order tens of cycles) for mass ratios ˜10-6. Computations of these corrections will require the computation of pieces of the forcing terms in the equations of motion which are currently unknown.

  17. Endotoxin Deactivation by Transient Acidification

    PubMed Central

    Ribeiro, Melina M.; Xu, Xiumin; Klein, Dagmar; Kenyon, Norma S; Ricordi, Camillo; Felipe, Maria Sueli S.; Pastori, Ricardo L.

    2015-01-01

    Recombinant proteins are an important tool for research and therapeutic applications. Therapeutic proteins have been delivered to several cell types and tissues and might be used to improve the outcome of the cell transplantation. Recombinant proteins are propagated in bacteria, which will contaminate them with the lypopolysacharide-endotoxin found in the outer bacterial membrane. Endotoxin could interfere with in vitro biological assays and is the major pathological factor, which must be removed or inactivated before in vivo administration. Here we describe a one-step protocol in which the endotoxin activity on recombinant proteins is remarkably reduced by transient exposure to acidic conditions. Maximum endotoxin deactivation occurs at acidic pH below their respective isoelectric point (pI). This method does not require additional protein purification or separation of the protein from the endotoxin fraction. The endotoxin level was measured both in vitro and in vivo. For in vitro assessment we have utilized Limulus Amebocyte Lysate method for in vivo the pyrogenic test. We have tested the above-mentioned method with 5 different recombinant proteins including a monoclonal antibody clone 5c8 against CD154 produced by hybridomas. More than 99% of endotoxin was deactivated in all of the proteins, the recovery of the protein after deactivation varied between maximum 72.9 and minimum 46.8%. The anti CD154 clone 5c8 activity remained unchanged as verified by the measurement of binding capability to activated lymphocytes. Furthermore, the effectiveness of this method was not significantly altered by urea, commonly used in protein purification. This procedure provides a simple and cost-efficient way to reduce the endotoxin activity in antibodies and recombinant proteins. PMID:20412635

  18. MICA Observations of Coronal Transients

    NASA Astrophysics Data System (ADS)

    Stenborg, G.; Schwenn, R.; Srivastava, N.

    1999-10-01

    Dynamical processes are well known to occur in the inner solar atmosphere, many of them giving origin to spectacular eruptions known as coronal mass ejections. The projected velocity of propagation of these events ranges from less than 100 km/sec to greater than 1200 km/sec. In order to study the initial evolution of the faster processes it is necessary to image the inner corona at a very high cadence. Although ground-based observations of the corona are strongly affected by sky conditions they allow imaging at a high temporal resolution as compared to coronagraphic observations from space. In the recently inaugurated German-Argentinean Solar-Observatory at El Leoncito, San Juan, Argentina, a mirror coronagraph (MICA) daily images the inner solar corona with high temporal and spatial resolution in two spectral ranges: the well known green (~1.8 MK) and red (~1.0 MK) coronal lines at 5303 A and 6374 A respectively. It is essentially similar in design to LASCO-C1 on board SOHO, its field-of-view ranging from 1.05 to 2.0 solar radii from the sun center. Thus, it is ideally suited to observe the hot material and reveal the fast processes that occur in the coronal plasma. In the last year MICA has recorded several fast and not so fast green line transients at a high temporal resolution. In this work we will present observations of a few such events. This study would allow us to have a better understanding of the conditions that trigger the coronal mass ejections and their propagation in the inner solar corona.

  19. Cable coupling lightning transient qualification

    NASA Technical Reports Server (NTRS)

    Cook, M.

    1989-01-01

    Simulated lightning strike testing of instrumentation cabling on the redesigned solid rocket motor was performed. Testing consisted of subjecting the lightning evaluation test article to simulated lightning strikes and evaluating the effects of instrumentation cable transients on cables within the system tunnel. The maximum short-circuit current induced onto a United Space Boosters, Inc., operational flight cable within the systems tunnel was 92 A, and the maximum induced open-circuit voltage was 316 V. These levels were extrapolated to the worst-case (200 kA) condition of NASA specification NSTS 07636 and were also scaled to full-scale redesigned solid rocket motor dimensions. Testing showed that voltage coupling to cables within the systems tunnel can be reduced 40 to 90 dB and that current coupling to cables within the systems tunnel can be reduced 30 to 70 dB with the use of braided metallic sock shields around cables that are external to the systems tunnel. Testing also showed that current and voltage levels induced onto cables within the systems tunnel are partially dependant on the cables' relative locations within the systems tunnel. Results of current injections to the systems tunnel indicate that the dominant coupling mode on cables within the systems tunnel is not from instrumentation cables but from coupling through the systems tunnel cover seam apertures. It is recommended that methods of improving the electrical bonding between individual sections of the systems tunnel covers be evaluated. Further testing to better characterize redesigned solid rocket motor cable coupling effects as an aid in developing methods to reduce coupling levels, particularly with respect to cable placement within the systems tunnel, is also recommended.

  20. Terror mit Atomwaffen: reale Gefahr? Nukleare und Radiologische Waffen

    NASA Astrophysics Data System (ADS)

    Harigel, Gert G.

    2006-01-01

    Können Terroristen sich nukleare Massenvernichtungswaffen beschaffen? Dazu müssten sie ausreichende Mengen an waffenfähigem, spaltbarem Material stehlen. Selbst der Bau einer primitiven Atombombe erfordert einen hohen technischen Aufwand und Spezialisten. Wahrscheinlicher ist deshalb der Diebstahl einer kleinen taktischen Kernwaffe. Alternativ könnten Terroristen sich radioaktives Material aus zivilen Quellen beschaffen und daraus eine Schmutzige Bombe bauen. Eine solche radiologische Waffe wäre keine echte Massenvernichtungswaffe, doch ihre psychologische Wirkung könnte stark sein. Das macht sie für Terroristen attraktiv, weswegen diese Gefahr ernst genommen werden muss.

  1. Reflexionseigenschaften von Windenergieanlagen im Funkfeld von Funknavigations- und Radarsystemen

    NASA Astrophysics Data System (ADS)

    Sandmann, S.; Divanbeigi, S.; Garbe, H.

    2015-11-01

    Die hier behandelte Untersuchung befasst sich mit den Störungen des elektrischen Feldes einer Doppler Very High Frequency Omnidirectional Radio Range Navigationsanlage (DVOR) in der Gegenwart von Windenergieanlagen (WEA). Hierfür wird die Feldstärke auf 25 konzentrischen Kreisbahnen, sog. Orbit Flights verschiedener Höhen und mit verschiedenen Radien rund um die DVOR-Anlage numerisch simuliert. Insbesondere werden die Einflüsse diverser Parameter der WEA wie deren Anzahl, Position, Rotorwinkel, Turmhöhe und Rotordurchmesser auf die Feldverteilung herausgestellt, sowie die Anwendbarkeit der Simulationsmethode Physical Optics (PO) durch Vergleich der Simulationsergebnisse mit denen der Multi Level Fast Multipol Method (MLFMM) untersucht.

  2. Primary progressive aphasia and transient global amnesia

    PubMed Central

    Graff-Radford, Jonathan; Josephs, Keith A.

    2014-01-01

    Objective To report three patients with history of transient global amnesia who developed primary progressive aphasia. Patients Three patients presenting to the Neurology clinic with language complaints Setting Tertiary care center Results We describe three patients with a history of transient global amnesia who were subsequently diagnosed with primary progressive aphasia. All patients had recurrent attacks of transient global amnesia. The diagnoses of primary progressive aphasia were supported by speech pathology evaluations, neuropsychometric testing and imaging findings. PET scans, for example, revealed left posterior frontal hypometabolism in one patient, predominately left temporal-parietal hypometabolism in another while single-photon emission computed tomography demonstrated decreased perfusion in the anterior left temporal and frontal lobe in the third. Conclusions There may be a relationship between recurrent transient global amnesia and the development of primary progressive aphasia. PMID:22410450

  3. Transient topographical amnesia: a case report.

    PubMed

    Mazzoni, M; Del Torto, E; Vista, M; Moretti, P

    1993-12-01

    We describe the case of a 56 year old female, with history of migraine since adolescence, who experienced two episodes of transient topographical disorientation in the absence of intellectual deterioration or evident focal cerebral lesions.

  4. Transient thermal analysis of fluid systems

    NASA Technical Reports Server (NTRS)

    Chandler, G. D.; Trust, R. D.

    1977-01-01

    Computer program performs transient thermal analysis of any 2-node to 200-node-thermal network, which transports heat by fluid flow convection. Program can be modified to add conduction along tubes and radiation.

  5. Transient Phenomena: Opportunities for New Discoveries

    NASA Technical Reports Server (NTRS)

    Lazio, T. Joseph W.

    2010-01-01

    Known classes of radio wavelength transients range from the nearby (stellar flares and radio pulsars) to the distant Universe (gamma-ray burst afterglows). Hypothesized classes of radio transients include analogs of known objects, such as extrasolar planets emitting Jovian-like radio bursts and giant-pulse emitting pulsars in other galaxies, to the exotic, such as prompt emission from gamma-ray bursts, evaporating black holes and transmitters from other civilizations. Time domain astronomy has been recognized internationally as a means of addressing key scientific questions in astronomy and physics, and pathfinders and Precursors to the Square Kilometre Array (SKA) are beginning to offer a combination of wider fields of view and more wavelength agility than has been possible in the past. These improvements will continue when the SKA itself becomes operational. I illustrate the range of transient phenomena and discuss how the detection and study of radio transients will improve immensely.

  6. Transient transfection of purified Babesia bovis merozoites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Transient transfection of intraerythrocytic Babesia bovis parasites has been previously reported. In this study, we describe the development and optimization of methods for transfection of purified B. bovis merozoites using either nucleofection (Amaxa) or conventional electroporation (Gene Pulser II...

  7. Transient Wave Envelope Elements for Wave Problems

    NASA Astrophysics Data System (ADS)

    Astley, R. J.

    1996-04-01

    A novel family of infinite wave envelope elements is described which can be used in conjunction with conventional finite elements to model the transient wave equation in unbounded regions. The elements are obtained by applying an inverse Fourier transformation to a mapped wave envelope formulation in the frequency domain. The discrete transient equations obtained in this way can be applied to two-dimensional and three-dimensional problems without restriction, being valid over a full range of excitation frequencies. The effectiveness and accuracy of the method is demonstrated in application to simple test cases which involve the calculation of transient sound fields generated by pulsating spheres and cylinders excited from rest in an unbounded region. Test solutions are compared to analytic solutions and to finite element solutions obtained by using large computational grids which extend beyond the region influenced by the transient disturbance.

  8. Concurrent algorithms for transient FE analysis

    NASA Technical Reports Server (NTRS)

    Ortiz, M.; Nour-Omid, B.

    1989-01-01

    Information on concurrent algorithms for transient finite element analysis is given in viewgraph form. Information is given on concurrent dynamic algorithms, interprocessor communication, the performance of the BAR problem on the 32 Processor Hypercube, computational efficiency and accuracy analysis.

  9. Detection of Radio Transients from Supernovae

    NASA Astrophysics Data System (ADS)

    Schmitt, Christian

    2011-05-01

    A core-collapse supernova (SN) would produce an expanding shell of charged particles which interact with the surrounding magnetic field of the progenitor star producing a transient radio pulse. Approximately one supernova event per century is expected in a galaxy. The radio waves emitted are detectable by a new generation of low-frequency radio telescope arrays. We present details of an ongoing search for such events by the Eight-meter-wavelength Transient Array (ETA) and the Long Wavelength Array (LWA).

  10. Transient ischemic attack presenting in an elderly patient with transient ophthalmic manifestations.

    PubMed

    Jain, Sparshi; Saxena, Tishu; Singh, Sweta; Singh, Nidhi

    2016-01-01

    Transient ischemic attack (TIA) is a transient neurological deficit of cerebrovascular origin without infarction which may last only for a short period and can have varying presentations. We report a case of 58-year-old male with presenting features of sudden onset transient vertical diplopia and transient rotatory nystagmus which self-resolved within 12 h. Patient had no history of any systemic illness. On investigating, hematological investigations and neuroimaging could not explain these sudden and transient findings. A TIA could possibly explain these sudden and transient ocular findings in our patient. This case report aims to highlight the importance of TIA for ophthalmologists. We must not ignore these findings as these could be warning signs of an impending stroke which may or may not be detected on neuroimaging. Thus, early recognition, primary prevention strategies, and timely intervention are needed.

  11. Elektronenröhrenforschung nach 1945 Telefunkenforscher in Ost und West und das Scheitern des Konzepts der „Gnom-Röhren“ in Erfurt

    NASA Astrophysics Data System (ADS)

    Dörfel, Günter; Tobies, Renate

    Elektronenröhren standen wegen ihrer Rüstungsrelevanz nach Kriegsende unter dem Vorbehalt der Besatzungsmächte. Unter dem Druck eigener materieller Defizite erlaubte und initiierte die sowjetische Besatzungsmacht Entwicklungen dazu eher als die westlichen Alliierten. Daraus resultierten bemerkenswerte Innovationen und Vorsprünge im Gebiet von Miniaturröhren.

  12. Transient Cognitive Dynamics, Metastability, and Decision Making

    PubMed Central

    Rabinovich, Mikhail I.; Huerta, Ramón; Varona, Pablo; Afraimovich, Valentin S.

    2008-01-01

    The idea that cognitive activity can be understood using nonlinear dynamics has been intensively discussed at length for the last 15 years. One of the popular points of view is that metastable states play a key role in the execution of cognitive functions. Experimental and modeling studies suggest that most of these functions are the result of transient activity of large-scale brain networks in the presence of noise. Such transients may consist of a sequential switching between different metastable cognitive states. The main problem faced when using dynamical theory to describe transient cognitive processes is the fundamental contradiction between reproducibility and flexibility of transient behavior. In this paper, we propose a theoretical description of transient cognitive dynamics based on the interaction of functionally dependent metastable cognitive states. The mathematical image of such transient activity is a stable heteroclinic channel, i.e., a set of trajectories in the vicinity of a heteroclinic skeleton that consists of saddles and unstable separatrices that connect their surroundings. We suggest a basic mathematical model, a strongly dissipative dynamical system, and formulate the conditions for the robustness and reproducibility of cognitive transients that satisfy the competing requirements for stability and flexibility. Based on this approach, we describe here an effective solution for the problem of sequential decision making, represented as a fixed time game: a player takes sequential actions in a changing noisy environment so as to maximize a cumulative reward. As we predict and verify in computer simulations, noise plays an important role in optimizing the gain. PMID:18452000

  13. Four RNA families with functional transient structures

    PubMed Central

    Zhu, Jing Yun A; Meyer, Irmtraud M

    2015-01-01

    Protein-coding and non-coding RNA transcripts perform a wide variety of cellular functions in diverse organisms. Several of their functional roles are expressed and modulated via RNA structure. A given transcript, however, can have more than a single functional RNA structure throughout its life, a fact which has been previously overlooked. Transient RNA structures, for example, are only present during specific time intervals and cellular conditions. We here introduce four RNA families with transient RNA structures that play distinct and diverse functional roles. Moreover, we show that these transient RNA structures are structurally well-defined and evolutionarily conserved. Since Rfam annotates one structure for each family, there is either no annotation for these transient structures or no such family. Thus, our alignments either significantly update and extend the existing Rfam families or introduce a new RNA family to Rfam. For each of the four RNA families, we compile a multiple-sequence alignment based on experimentally verified transient and dominant (dominant in terms of either the thermodynamic stability and/or attention received so far) RNA secondary structures using a combination of automated search via covariance model and manual curation. The first alignment is the Trp operon leader which regulates the operon transcription in response to tryptophan abundance through alternative structures. The second alignment is the HDV ribozyme which we extend to the 5′ flanking sequence. This flanking sequence is involved in the regulation of the transcript's self-cleavage activity. The third alignment is the 5′ UTR of the maturation protein from Levivirus which contains a transient structure that temporarily postpones the formation of the final inhibitory structure to allow translation of maturation protein. The fourth and last alignment is the SAM riboswitch which regulates the downstream gene expression by assuming alternative structures upon binding of SAM

  14. Four RNA families with functional transient structures.

    PubMed

    Zhu, Jing Yun A; Meyer, Irmtraud M

    2015-01-01

    Protein-coding and non-coding RNA transcripts perform a wide variety of cellular functions in diverse organisms. Several of their functional roles are expressed and modulated via RNA structure. A given transcript, however, can have more than a single functional RNA structure throughout its life, a fact which has been previously overlooked. Transient RNA structures, for example, are only present during specific time intervals and cellular conditions. We here introduce four RNA families with transient RNA structures that play distinct and diverse functional roles. Moreover, we show that these transient RNA structures are structurally well-defined and evolutionarily conserved. Since Rfam annotates one structure for each family, there is either no annotation for these transient structures or no such family. Thus, our alignments either significantly update and extend the existing Rfam families or introduce a new RNA family to Rfam. For each of the four RNA families, we compile a multiple-sequence alignment based on experimentally verified transient and dominant (dominant in terms of either the thermodynamic stability and/or attention received so far) RNA secondary structures using a combination of automated search via covariance model and manual curation. The first alignment is the Trp operon leader which regulates the operon transcription in response to tryptophan abundance through alternative structures. The second alignment is the HDV ribozyme which we extend to the 5' flanking sequence. This flanking sequence is involved in the regulation of the transcript's self-cleavage activity. The third alignment is the 5' UTR of the maturation protein from Levivirus which contains a transient structure that temporarily postpones the formation of the final inhibitory structure to allow translation of maturation protein. The fourth and last alignment is the SAM riboswitch which regulates the downstream gene expression by assuming alternative structures upon binding of SAM. All

  15. Rückwärtsintegration - Zu den Verhältnissen Gymnasium, Hochschule und Arbeitswelt

    NASA Astrophysics Data System (ADS)

    Schmid, Gerhard; Heppner, Winfried; Focht, Eva

    In seiner 2007 erschienen Sammlung von Vorträgen und Essays beschäftigt sich Wolfgang Frühwald, mit der Frage "Wieviel Wissen brauchen wir?“ [1] Die Kernproblematik moderner Wissenschaft und Forschung sieht der Autor, emeritierter Ordinarius für Neuere Deutsche Literaturwissenschaft und von 1992 bis 1997 Präsident der Deutschen Forschungsgemeinschaft, einerseits in der zunehmenden Spezialisierung der Wissenschaftsbereiche, andererseits in der Gefahr der Abkoppelung der Naturwissenschaften von den Geisteswissenschaften. Wiederholt plädiert er dafür, über der rasanten Entwicklung beispielsweise in der Biologie und Physik, die historische, gesellschaftliche und besonders die ethische Dimension der Forschung nicht zu übersehen und fordert eine übergeordnete Theorie der Wissenschaft, die nur im Dialog zwischen den einzelnen Fachgebieten zu entwickeln sei.

  16. Transient triggering of near and distant earthquakes

    USGS Publications Warehouse

    Gomberg, J.; Blanpied, M.L.; Beeler, N.M.

    1997-01-01

    We demonstrate qualitatively that frictional instability theory provides a context for understanding how earthquakes may be triggered by transient loads associated with seismic waves from near and distance earthquakes. We assume that earthquake triggering is a stick-slip process and test two hypotheses about the effect of transients on the timing of instabilities using a simple spring-slider model and a rate- and state-dependent friction constitutive law. A critical triggering threshold is implicit in such a model formulation. Our first hypothesis is that transient loads lead to clock advances; i.e., transients hasten the time of earthquakes that would have happened eventually due to constant background loading alone. Modeling results demonstrate that transient loads do lead to clock advances and that the triggered instabilities may occur after the transient has ceased (i.e., triggering may be delayed). These simple "clock-advance" models predict complex relationships between the triggering delay, the clock advance, and the transient characteristics. The triggering delay and the degree of clock advance both depend nonlinearly on when in the earthquake cycle the transient load is applied. This implies that the stress required to bring about failure does not depend linearly on loading time, even when the fault is loaded at a constant rate. The timing of instability also depends nonlinearly on the transient loading rate, faster rates more rapidly hastening instability. This implies that higher-frequency and/or longer-duration seismic waves should increase the amount of clock advance. These modeling results and simple calculations suggest that near (tens of kilometers) small/moderate earthquakes and remote (thousands of kilometers) earthquakes with magnitudes 2 to 3 units larger may be equally effective at triggering seismicity. Our second hypothesis is that some triggered seismicity represents earthquakes that would not have happened without the transient load (i

  17. Transient simulation of molten salt central receiver

    NASA Astrophysics Data System (ADS)

    Doupis, Dimitri; Wang, Chuan; Carcorze-Soto, Jorge; Chen, Yen-Ming; Maggi, Andrea; Losito, Matteo; Clark, Michael

    2016-05-01

    Alstom is developing concentrated solar power (CSP) utilizing 60/40wt% NaNO3-KNO3 molten salt as the working fluid in a tower receiver for the global renewable energy market. In the CSP power generation cycle, receivers undergo a daily cyclic operation due to the transient nature of solar energy. Development of robust and efficient start-up and shut-down procedures is critical to avoiding component failures due to mechanical fatigue resulting from thermal transients, thus maintaining the performance and availability of the CSP plant. The Molten Salt Central Receiver (MSCR) is subject to thermal transients during normal daily operation, a cycle that includes warmup, filling, operation, draining, and shutdown. This paper describes a study to leverage dynamic simulation and finite element analysis (FEA) in development of start-up, shutdown, and transient operation concepts for the MSCR. The results of the FEA also verify the robustness of the MSCR design to the thermal transients anticipated during the operation of the plant.

  18. Transient particle emission measurement with optical techniques

    NASA Astrophysics Data System (ADS)

    Bermúdez, Vicente; Luján, José M.; Serrano, José R.; Pla, Benjamín

    2008-06-01

    Particulate matter is responsible for some respiratory and cardiovascular diseases. In addition, it is one of the most important pollutants of high-speed direct injection (HSDI) passenger car engines. Current legislation requires particulate dilution tunnels for particulate matter measuring. However for development work, dilution tunnels are expensive and sometimes not useful since they are not able to quantify real-time particulate emissions during transient operation. In this study, the use of a continuous measurement opacimeter and a fast response HFID is proven to be a good alternative to obtain instantaneous particle mass emissions during transient operation (due to particulate matter consisting mainly of soot and SOF). Some methods and correlations available from literature, but developed for steady conditions, are evaluated during transient operation by comparing with mini-tunnel measurements during the entire MVEG-A transient cycle. A new correlation was also derived from this evaluation. Results for soot and SOF (obtained from the new correlation proposed) are compared with soot and SOF captured with particulate filters, which have been separated by means of an SOF extraction method. Finally, as an example of ECU design strategies using these sort of correlations, the EGR valve opening is optimized during transient operation. The optimization is performed while simultaneously taking into account instantaneous fuel consumption, particulate emissions (calculated with the proposed correlation) and other regulated engine pollutants.

  19. A Quantitative Study of the Characteristics of Transient and Non-Transient Students in Nevada Elementary Schools

    ERIC Educational Resources Information Center

    Parr, Andrew Joseph

    2010-01-01

    The purpose of this research was to determine whether transient or mobile students attain lower levels of academic achievement than non-transient students and to identify the characteristics distinguishing transient from non-transient students. The study analyzed the assessment results, student characteristics, and school factors for approximately…

  20. Chemotaxis Control of Transient Cell Aggregation

    PubMed Central

    2015-01-01

    Chemotaxis affords motile cells the ability to rapidly respond to environmental challenges by navigating cells to niches favoring growth. Such a property results from the activities of dedicated signal transduction systems on the motility apparatus, such as flagella, type IV pili, and gliding machineries. Once cells have reached a niche with favorable conditions, they often stop moving and aggregate into complex communities termed biofilms. An intermediate and reversible stage that precedes commitment to permanent adhesion often includes transient cell-cell contacts between motile cells. Chemotaxis signaling has been implicated in modulating the transient aggregation of motile cells. Evidence further indicates that chemotaxis-dependent transient cell aggregation events are behavioral responses to changes in metabolic cues that temporarily prohibit permanent attachment by maintaining motility and chemotaxis. This minireview discusses a few examples illustrating the role of chemotaxis signaling in the initiation of cell-cell contacts in bacteria moving via flagella, pili, or gliding. PMID:26216846

  1. Chemotaxis Control of Transient Cell Aggregation.

    PubMed

    Alexandre, Gladys

    2015-10-01

    Chemotaxis affords motile cells the ability to rapidly respond to environmental challenges by navigating cells to niches favoring growth. Such a property results from the activities of dedicated signal transduction systems on the motility apparatus, such as flagella, type IV pili, and gliding machineries. Once cells have reached a niche with favorable conditions, they often stop moving and aggregate into complex communities termed biofilms. An intermediate and reversible stage that precedes commitment to permanent adhesion often includes transient cell-cell contacts between motile cells. Chemotaxis signaling has been implicated in modulating the transient aggregation of motile cells. Evidence further indicates that chemotaxis-dependent transient cell aggregation events are behavioral responses to changes in metabolic cues that temporarily prohibit permanent attachment by maintaining motility and chemotaxis. This minireview discusses a few examples illustrating the role of chemotaxis signaling in the initiation of cell-cell contacts in bacteria moving via flagella, pili, or gliding.

  2. WIDGET: Ultra Bright Optical Transients Search

    NASA Astrophysics Data System (ADS)

    Urata, Y.; Lin, H.-M.; Tashiro, M.; Widget Team

    2010-12-01

    The WIDeField telescope for Gamma-ray burst Early Timing (WIDGET) is used for a fully automated, ultra-wide-field survey aimed at detecting the prompt optical emission associated with Gamma-ray Bursts (GRB). WIDGET surveys the HETE-2 and Swift/BAT pointing directions covering a total field of view of 62x62 degree every 10 seconds using an unfiltered system. This monitoring survey allows exploration of the optical emission before the gamma-ray trigger. At the same time, WIDGET is the quite unique instrument to explore ultra-bright optical transients with high time resolution. Combination with the MAXI survey, WIDGET has higher potential to make simultaneous discoveries of optical counterparts for high energy transients. We developed the serendipitous transient finding pipeline. We report the preliminary results.

  3. Transient expression technologies: past, present, and future.

    PubMed

    Geisse, Sabine; Voedisch, Bernd

    2012-01-01

    The first protocols describing transient gene expression in mammalian cells for the rapid generation of recombinant proteins emerged more than 10 years ago as an alternative to the establishment of stable, often amplified clonal cell lines, and relieved somewhat the bias against mammalian cell systems as being too complicated, labor intensive, and tedious to serve as a source for tool proteins in industrial research and academia. Over the past decade, these attempts have been refined and optimized, giving rise to expression protocols applicable in every lab in dependence on available tools, equipment, and envisaged outcome. This chapter summarizes the development of transient expression technologies over the past decade up to its current status and provides an outlook into what may be the future of transient technology development.

  4. Transient misfolding dominates multidomain protein folding

    PubMed Central

    Borgia, Alessandro; Kemplen, Katherine R.; Borgia, Madeleine B.; Soranno, Andrea; Shammas, Sarah; Wunderlich, Bengt; Nettels, Daniel; Best, Robert B.; Clarke, Jane; Schuler, Benjamin

    2015-01-01

    Neighbouring domains of multidomain proteins with homologous tandem repeats have divergent sequences, probably as a result of evolutionary pressure to avoid misfolding and aggregation, particularly at the high cellular protein concentrations. Here we combine microfluidic-mixing single-molecule kinetics, ensemble experiments and molecular simulations to investigate how misfolding between the immunoglobulin-like domains of titin is prevented. Surprisingly, we find that during refolding of tandem repeats, independent of sequence identity, more than half of all molecules transiently form a wide range of misfolded conformations. Simulations suggest that a large fraction of these misfolds resemble an intramolecular amyloid-like state reported in computational studies. However, for naturally occurring neighbours with low sequence identity, these transient misfolds disappear much more rapidly than for identical neighbours. We thus propose that evolutionary sequence divergence between domains is required to suppress the population of long-lived, potentially harmful misfolded states, whereas large populations of transient misfolded states appear to be tolerated. PMID:26572969

  5. Earthquake triggering by transient and static deformations

    USGS Publications Warehouse

    Gomberg, J.; Beeler, N.M.; Blanpied, M.L.; Bodin, P.

    1998-01-01

    Observational evidence for both static and transient near-field and far-field triggered seismicity are explained in terms of a frictional instability model, based on a single degree of freedom spring-slider system and rate- and state-dependent frictional constitutive equations. In this study a triggered earthquake is one whose failure time has been advanced by ??t (clock advance) due to a stress perturbation. Triggering stress perturbations considered include square-wave transients and step functions, analogous to seismic waves and coseismic static stress changes, respectively. Perturbations are superimposed on a constant background stressing rate which represents the tectonic stressing rate. The normal stress is assumed to be constant. Approximate, closed-form solutions of the rate-and-state equations are derived for these triggering and background loads, building on the work of Dieterich [1992, 1994]. These solutions can be used to simulate the effects of static and transient stresses as a function of amplitude, onset time t0, and in the case of square waves, duration. The accuracies of the approximate closed-form solutions are also evaluated with respect to the full numerical solution and t0. The approximate solutions underpredict the full solutions, although the difference decreases as t0, approaches the end of the earthquake cycle. The relationship between ??t and t0 differs for transient and static loads: a static stress step imposed late in the cycle causes less clock advance than an equal step imposed earlier, whereas a later applied transient causes greater clock advance than an equal one imposed earlier. For equal ??t, transient amplitudes must be greater than static loads by factors of several tens to hundreds depending on t0. We show that the rate-and-state model requires that the total slip at failure is a constant, regardless of the loading history. Thus a static load applied early in the cycle, or a transient applied at any time, reduces the stress

  6. A CCD integrated circuit for transient recorders

    NASA Technical Reports Server (NTRS)

    Balch, J. W.; Mcconaghy, C. F.

    1976-01-01

    A 50 MHz CCD integrated circuit is described that was developed for use in transient analog signal recorders to sample and time expand transient signals. The integrated circuit achieves an effective 200 MHz sample rate by using four 32 stage peristaltic CCDs to sample the transient signal four times each clock period. Dual frequency, 4 phi clocking is used to sample and time expand the sampled data. The output signals of the four CCDs are multiplexed on chip into a single low frequency output data line. When operated with 50 MHz/165 KHz 4 phi clocks, this circuit has a 200 MHz sample rate, a record length of 640 nanoseconds, a time expansion factor of 303, and overall signal to noise ratio of 40:1. The signal to noise ratio is limited by fixed pattern noise of the four CCDs.

  7. Transient thermal camouflage and heat signature control

    NASA Astrophysics Data System (ADS)

    Yang, Tian-Zhi; Su, Yishu; Xu, Weikai; Yang, Xiao-Dong

    2016-09-01

    Thermal metamaterials have been proposed to manipulate heat flux as a new way to cloak or camouflage objects in the infrared world. To date, however, thermal metamaterials only operate in the steady-state and exhibit detectable, transient heat signatures. In this letter, the theoretical basis for a thermal camouflaging technique with controlled transient diffusion is presented. This technique renders an object invisible in real time. More importantly, the thermal camouflaging device instantaneously generates a pre-designed heat signature and behaves as a perfect thermal illusion device. A metamaterial coating with homogeneous and isotropic thermal conductivity, density, and volumetric heat capacity was fabricated and very good camouflaging performance was achieved.

  8. Transient astronomy with the Gaia satellite.

    PubMed

    Hodgkin, Simon T; Wyrzykowski, Łukasz; Blagorodnova, Nadejda; Koposov, Sergey

    2013-06-13

    Gaia is a cornerstone European Space Agency astrometry space mission and a successor to the Hipparcos mission. Gaia will observe the whole sky for 5 years, providing a serendipitous opportunity for the discovery of large numbers of transient and anomalous events, e.g. supernovae, novae and microlensing events, gamma-ray burst afterglows, fallback supernovae, as well as theoretical or unexpected phenomena. In this paper, we discuss our preparations to use Gaia to search for transients at optical wavelengths, and briefly describe the early detection, classification and prompt publication of anomalous sources. PMID:23630374

  9. Transient Rayleigh scattering from single semiconductor nanowires

    SciTech Connect

    Montazeri, Mohammad; Jackson, Howard E.; Smith, Leigh M.; Yarrison-Rice, Jan M.; Kang, Jung-Hyun; Gao, Qiang; Tan, Hark Hoe; Jagadish, Chennupati

    2013-12-04

    Transient Rayleigh scattering spectroscopy is a new pump-probe technique to study the dynamics and cooling of photo-excited carriers in single semiconductor nanowires. By studying the evolution of the transient Rayleigh spectrum in time after excitation, one can measure the time evolution of the density and temperature of photo-excited electron-hole plasma (EHP) as they equilibrate with lattice. This provides detailed information of dynamics and cooling of carriers including linear and bimolecular recombination properties, carrier transport characteristics, and the energy-loss rate of hot electron-hole plasma through the emission of LO and acoustic phonons.

  10. Modeling system for conducted transient analysis

    SciTech Connect

    Mahoney, T.L.

    1983-01-01

    A computer simulation system has been developed which facilitates the analysis of electrical/electronic systems. Sponsored by the Naval Air Systems Command to investigate power interface transient problems, the program is called the Navy Power Systems Simulator. The simulator is used as a system engineering tool which generates and processes models of virtually any electrical network. It is simple to use and capable of automatically producing a complex system's steady state or transient output response. An engineering friendly computer interface has been achieved by the extensive use of interactive graphics and menu-driven prompting.

  11. Iterative phase retrieval strategy of transient events.

    PubMed

    Ng, Tuck Wah; Chua, Adrian Sau Ling

    2012-01-20

    Important nuances of a process or processes in action can be obtained from the phase retrieval of diffraction patterns for analysis of transient events. A significant limitation associated with the iterative approach is that predictive input functions are needed and can result in situations of nonconvergence. In dealing with a transient event recorded as a series of Fourier magnitude patterns, such a hit-and-miss characteristic, on the surface, appears computationally daunting. We report and demonstrate a strategy here that effectively minimizes this by using a prior retrieved frame as the predictive function for the current retrieval process. PMID:22270666

  12. Experimental verification of transient nonlinear acoustical holography.

    PubMed

    Jing, Yun; Cannata, Jonathan; Wang, Tianren

    2013-05-01

    This paper presents an experimental study on nonlinear transient acoustical holography. The validity and effectiveness of a recently proposed nonlinear transient acoustical holography algorithm is evaluated in the presence of noise. The acoustic field measured on a post-focal plane of a high-intensity focused transducer is backward projected to reconstruct the pressure distributions on the focal and a pre-focal plane, which are shown to be in good agreement with the measurement. In contrast, the conventional linear holography produces erroneous results in this case where the nonlinearity involved is strong. Forward acoustic field projection was also carried out to further verify the algorithm. PMID:23654362

  13. LMR Transient Calculation Code System (version 5).

    1993-09-01

    Version: 00 The Liquid Metal Reactor (LMR) may undergo an unscrammed Transient Over-Power (TOP) or a Loss of Heat Sink (LOHS) type of accident involving power, temperature, and reactivity changes. The LTC (LMR Transient Calculation) Program calculates the time dependent reactor temperatures, reactivities, and power of the LMR after the initiation of the accident. A printout of the results including the input table of data is offered after the program run. No graphics are usedmore » in the program and the LTC.EXE (Quick Basic compiled) can make use of a math co-processor if available (GW Basic doesn't).« less

  14. Experimental verification of transient nonlinear acoustical holography.

    PubMed

    Jing, Yun; Cannata, Jonathan; Wang, Tianren

    2013-05-01

    This paper presents an experimental study on nonlinear transient acoustical holography. The validity and effectiveness of a recently proposed nonlinear transient acoustical holography algorithm is evaluated in the presence of noise. The acoustic field measured on a post-focal plane of a high-intensity focused transducer is backward projected to reconstruct the pressure distributions on the focal and a pre-focal plane, which are shown to be in good agreement with the measurement. In contrast, the conventional linear holography produces erroneous results in this case where the nonlinearity involved is strong. Forward acoustic field projection was also carried out to further verify the algorithm.

  15. Transient astronomy with the Gaia satellite.

    PubMed

    Hodgkin, Simon T; Wyrzykowski, Łukasz; Blagorodnova, Nadejda; Koposov, Sergey

    2013-06-13

    Gaia is a cornerstone European Space Agency astrometry space mission and a successor to the Hipparcos mission. Gaia will observe the whole sky for 5 years, providing a serendipitous opportunity for the discovery of large numbers of transient and anomalous events, e.g. supernovae, novae and microlensing events, gamma-ray burst afterglows, fallback supernovae, as well as theoretical or unexpected phenomena. In this paper, we discuss our preparations to use Gaia to search for transients at optical wavelengths, and briefly describe the early detection, classification and prompt publication of anomalous sources.

  16. Transient aspects of stream interface signatures

    SciTech Connect

    Crooker, N.U.; Shodhan, S.; Forsyth, R.J.; Burton, M.E.; Gosling, J.T.; Fitzenreiter, R.J.; Lepping, R.P.

    1999-06-01

    Although stream interfaces are steady-state, corotating boundaries between slow and fast solar wind, their signatures are sometimes associated with transient features. Here the authors illustrate two modes of association: interfaces trailing interplanetary coronal mass ejections (ICMEs) at 1 AU and interfaces within ICMEs in the range 4--5 AU. The former are readily understood as boundaries between transient slow wind and steady-state fast wind, where the ICMEs add variability to the interface signatures. The latter are puzzling and may be related to evolution of interfaces.

  17. Transient Molecular Transfer During Vacuum Testing

    NASA Technical Reports Server (NTRS)

    Perry, Radford L.

    2011-01-01

    A common question in contamination budgeting involves the loss of collected volatiles during ambient I&T activity under vacuum and the resultant cross-contamination from outgassing. (1) How much of the material collected under ambient conditions evaporates under vacuum? (2) Why do pristine surfaces sometimes show increased molecular contamination after vacuum bakeout? (3) How much of the collected molecular contamination is transient (i.e. migratory) and how much is permanent? Measuring the transient deposition may be accomplished using a thermally passive QCM

  18. Biocatalytic Pathway Selection in Transient Tripeptide Nanostructures.

    PubMed

    Pappas, Charalampos G; Sasselli, Ivan R; Ulijn, Rein V

    2015-07-01

    Structural adaption in living systems is achieved by competing catalytic pathways that drive assembly and disassembly of molecular components under the influence of chemical fuels. We report on a simple mimic of such a system that displays transient, sequence-dependent formation of supramolecular nanostructures based on biocatalytic formation and hydrolysis of self-assembling tripeptides. The systems are catalyzed by α-chymotrypsin and driven by hydrolysis of dipeptide aspartyl-phenylalanine-methyl ester (the sweetener aspartame, DF-OMe). We observed switch-like pathway selection, with the kinetics and consequent lifetime of transient nanostructures controlled by the peptide sequence. In direct competition, kinetic (rather than thermodynamic) component selection is observed.

  19. Transient inhibitory seizures mimicking crescendo TIAs.

    PubMed

    Lee, H; Lerner, A

    1990-01-01

    Somatic inhibitory seizures are thought to occur rarely. We describe a patient with somatic inhibitory seizures who initially presented with a clinical picture of crescendo transient ischemic attacks. He did not improve with anticoagulation, but the episodes ceased promptly after the administration of an anticonvulsant.

  20. Intermittent/transient faults in digital systems

    NASA Technical Reports Server (NTRS)

    Masson, G. M.; Glazer, R. E.

    1982-01-01

    Containment set techniques are applied to 8085 microprocessor controllers so as to transform a typical control system into a slightly modified version, shown to be crashproof: after the departure of the intermittent/transient fault, return to one proper control algorithm is assured, assuming no permanent faults occur.

  1. Laser spectroscopy and dynamics of transient species

    SciTech Connect

    Clouthier, D.J.

    1993-12-01

    The goal of this program is to study the vibrational and electronic spectra and excited state dynamics of a number of transient sulfur and oxygen species. A variety of supersonic jet techniques, as well as high resolution FT-IR and intracavity dye laser spectroscopy, have been applied to these studies.

  2. Thermally triggered degradation of transient electronic devices.

    PubMed

    Park, Chan Woo; Kang, Seung-Kyun; Hernandez, Hector Lopez; Kaitz, Joshua A; Wie, Dae Seung; Shin, Jiho; Lee, Olivia P; Sottos, Nancy R; Moore, Jeffrey S; Rogers, John A; White, Scott R

    2015-07-01

    Thermally triggered transient electronics using wax-encapsulated acid, which enable rapid device destruction via acidic degradation of the metal electronic components are reported. Using a cyclic poly(phthalaldehyde) (cPPA) substrate affords a more rapid destruction of the device due to acidic depolymerization of cPPA.

  3. Video Storytelling in a Transient, Volunteer Organization

    ERIC Educational Resources Information Center

    Katzeff, Cecilia; Ware, Vanessa

    2007-01-01

    To make sense of and learn about work environments, people actively construct their own knowledge and share stories of their experience. Telling stories is particularly challenging in a transient organization where people are hired on a voluntary, temporary basis. Such is the case of a nonprofit music festival organization in Sweden, which is…

  4. Transient Microphonic Effects In Superconducting Cavities

    SciTech Connect

    Thomas Powers; G. Davis; Lawrence King

    2005-07-10

    A number of experiments were performed on an installed and operational 5-cell CEBAF cavity to determine the minimum time required to reestablish stable gradient after a cavity window arc trip. Once it was determined that gradient could be reestablished within 10 ms by applying constant power RF signal in and a voltage controlled Oscillator-phase locked loop based system (VCO-PLL), a second experiment was performed to determine if stable gradient could be reestablished using a fixed frequency RF system with a simple gradient based closed loop control system. During this test, instabilities were observed in the cavity forward power signal, which were determined to be microphonic in nature. These microphonic effects were quantified using a cavity resonance monitor and a VCO{_}PLL RF system. Two types of microphonic effects were observed depending on the type of arc event. If the arc occurred in the vacuum space between the warm and cold windows, the transient frequency shift was about 75 Hz peak-to-peak. If the arc occurred on the cavity side of the cold window the transient frequency shift was about 400 Hz peak-to-peak. The background microphonics level for the tested cavity was approximately 30 Hz peak-to-peak. Experimental results, analysis of the resultant klystron power transients, the decay time of the transients, and the implications with respect to fast reset algorithms will be presented.

  5. Structure determination of transient transcription complexes.

    PubMed

    Cramer, Patrick

    2016-08-15

    The determination of detailed 3D structures of large and transient multicomponent complexes remains challenging. Here I describe the approaches that were used and developed by our laboratory to achieve structure solution of eukaryotic transcription complexes. I hope this collection serves as a resource for structural biologists seeking solutions for difficult structure determination projects. PMID:27528766

  6. Interpreting signals from astrophysical transient experiments

    PubMed Central

    O’Brien, Paul T.; Smartt, Stephen J.

    2013-01-01

    Time-domain astronomy has come of age with astronomers now able to monitor the sky at high cadence, both across the electromagnetic spectrum and using neutrinos and gravitational waves. The advent of new observing facilities permits new science, but the ever-increasing throughput of facilities demands efficient communication of coincident detections and better subsequent coordination among the scientific community so as to turn detections into scientific discoveries. To discuss the revolution occurring in our ability to monitor the Universe and the challenges it brings, on 25–26 April 2012, a group of scientists from observational and theoretical teams studying transients met with representatives of the major international transient observing facilities at the Kavli Royal Society International Centre, UK. This immediately followed the Royal Society Discussion Meeting ‘New windows on transients across the Universe’ held in London. Here, we present a summary of the Kavli meeting at which the participants discussed the science goals common to the transient astronomy community and analysed how to better meet the challenges ahead as ever more powerful observational facilities come on stream. PMID:23630383

  7. Neurodevelopmental outcome of transient neonatal intracerebral echodensities.

    PubMed

    Appleton, R E; Lee, R E; Hey, E N

    1990-01-01

    The later neurodevelopmental progress of 15 babies who had neonatal periventricular echodensities or flares in the absence of any intraventricular bleeding or subsequent cystic degeneration was studied. At follow up four infants had neurological abnormalities, including spastic diplegia (n = 2). These findings suggest that transient flares may represent mild periventricular leucomalacia with consequent mild neurological dysfunction. PMID:2407199

  8. Detecting aseismic strain transients from seismicity data

    USGS Publications Warehouse

    Llenos, A.L.; McGuire, J.J.

    2011-01-01

    Aseismic deformation transients such as fluid flow, magma migration, and slow slip can trigger changes in seismicity rate. We present a method that can detect these seismicity rate variations and utilize these anomalies to constrain the underlying variations in stressing rate. Because ordinary aftershock sequences often obscure changes in the background seismicity caused by aseismic processes, we combine the stochastic Epidemic Type Aftershock Sequence model that describes aftershock sequences well and the physically based rate- and state-dependent friction seismicity model into a single seismicity rate model that models both aftershock activity and changes in background seismicity rate. We implement this model into a data assimilation algorithm that inverts seismicity catalogs to estimate space-time variations in stressing rate. We evaluate the method using a synthetic catalog, and then apply it to a catalog of M???1.5 events that occurred in the Salton Trough from 1990 to 2009. We validate our stressing rate estimates by comparing them to estimates from a geodetically derived slip model for a large creep event on the Obsidian Buttes fault. The results demonstrate that our approach can identify large aseismic deformation transients in a multidecade long earthquake catalog and roughly constrain the absolute magnitude of the stressing rate transients. Our method can therefore provide a way to detect aseismic transients in regions where geodetic resolution in space or time is poor. Copyright 2011 by the American Geophysical Union.

  9. Interpreting signals from astrophysical transient experiments.

    PubMed

    O'Brien, Paul T; Smartt, Stephen J

    2013-06-13

    Time-domain astronomy has come of age with astronomers now able to monitor the sky at high cadence, both across the electromagnetic spectrum and using neutrinos and gravitational waves. The advent of new observing facilities permits new science, but the ever-increasing throughput of facilities demands efficient communication of coincident detections and better subsequent coordination among the scientific community so as to turn detections into scientific discoveries. To discuss the revolution occurring in our ability to monitor the Universe and the challenges it brings, on 25-26 April 2012, a group of scientists from observational and theoretical teams studying transients met with representatives of the major international transient observing facilities at the Kavli Royal Society International Centre, UK. This immediately followed the Royal Society Discussion Meeting 'New windows on transients across the Universe' held in London. Here, we present a summary of the Kavli meeting at which the participants discussed the science goals common to the transient astronomy community and analysed how to better meet the challenges ahead as ever more powerful observational facilities come on stream. PMID:23630383

  10. Inhomogeneous Forcing and Transient Climate Sensitivity

    NASA Technical Reports Server (NTRS)

    Shindell, Drew T.

    2014-01-01

    Understanding climate sensitivity is critical to projecting climate change in response to a given forcing scenario. Recent analyses have suggested that transient climate sensitivity is at the low end of the present model range taking into account the reduced warming rates during the past 10-15 years during which forcing has increased markedly. In contrast, comparisons of modelled feedback processes with observations indicate that the most realistic models have higher sensitivities. Here I analyse results from recent climate modelling intercomparison projects to demonstrate that transient climate sensitivity to historical aerosols and ozone is substantially greater than the transient climate sensitivity to CO2. This enhanced sensitivity is primarily caused by more of the forcing being located at Northern Hemisphere middle to high latitudes where it triggers more rapid land responses and stronger feedbacks. I find that accounting for this enhancement largely reconciles the two sets of results, and I conclude that the lowest end of the range of transient climate response to CO2 in present models and assessments (less than 1.3 C) is very unlikely.

  11. Transient (lightning) protection for electronic measurement devices

    SciTech Connect

    Black, L.L.

    1995-12-01

    Electronic measurement devices have become a major part of the oil and gas business today. All of these devices operate on an electrical voltage. Any voltage introduced into the system that is beyond the predetermined tolerance will cause degradation of performance or in some cases failure of the device. The extent of the damage depends upon the dielectric strength of the circuit in question and upon the available energy. As electronic measurement devices are further developed to incorporate more solid state circuitry and operate at lower voltage levels the more susceptible they become to transients. Along with transient protection, the user must also be concerned with intrinsic safety requirements of the device to be protected. The devices and techniques used to protect the equipment from transients do not, in all cases, guarantee the user certification for use in hazardous environments. As a note of reference, some of the techniques listed in this paper as examples would not be allowed in hazardous areas without the addition of other devices to further isolate or clamp the available energy to a safe level. In other words, as the industry moves forward to improve the overall accuracy of the measurement system and adds data availability via communication networks, the transient protection scheme must become more sophisticated.

  12. Circuit controls transients in SCR inverters

    NASA Technical Reports Server (NTRS)

    Moore, E. T.; Wilson, T. G.

    1964-01-01

    Elimination of starting difficulties in SCR inverters is accomplished by the addition of two taps of the output winding of the inverter. On starting or under transient loads, the two additional taps deliver power through diodes without requiring quenching of SCR currents in excess of normal starting load.

  13. Transient Non Lin Deformation in Fractured Rock

    1998-10-14

    MATLOC is a nonlinear, transient, two-dimensional (planer and axisymmetric), thermal stress, finite-element code designed to determine the deformation within a fractured rock mass. The mass is modeled as a nonlinear anistropic elastic material which can exhibit stress-dependent bi-linear locking behavior.

  14. The Zwicky transient facility observing system

    NASA Astrophysics Data System (ADS)

    Smith, Roger M.; Dekany, Richard G.; Bebek, Christopher; Bellm, Eric; Bui, Khanh; Cromer, John; Gardner, Paul; Hoff, Matthew; Kaye, Stephen; Kulkarni, Shrinivas; Lambert, Andrew; Levi, Michael; Reiley, Dan

    2014-07-01

    The Zwicky Transient Facility (ZTF) is a synoptic optical survey for high-cadence time-domain astronomy. Building upon the experience and infrastructure of the highly successful Palomar Transient Factory (PTF) team, ZTF will survey more than an order of magnitude faster than PTF in sky area and volume in order to identify rare, rapidly varying optical sources. These sources will include a trove of supernovae, exotic explosive transients, unusual stellar variables, compact binaries, active galactic nuclei, and asteroids. The single-visit depth of 20.4 mag is well matched to spectroscopic follow-up observations, while the co-added images will provide wide sky coverage 1.5 - 2 mag deeper than SDSS. The ZTF survey will cover the entire Northern Sky and revisit fields on timescales of a few hours, providing hundreds of visits per field each year, an unprecedented cadence, as required to detect fast transients and variability. This high-cadence survey is enabled by an observing system based on a new camera having 47 deg2 field of view - a factor of 6.5 greater than the existing PTF camera - equipped with fast readout electronics, a large, fast exposure shutter, faster telescope and dome drives, and various measures to optimize delivered image quality. Our project has already received an initial procurement of e2v wafer-scale CCDs and we are currently fabricating the camera cryostat. International partners and the NSF committed funds in June 2014 so construction can proceed as planned to commence engineering commissioning in 2016 and begin operations in 2017. Public release will allow broad utilization of these data by the US astronomical community. ZTF will also promote the development of transient and variable science methods in preparation for the seminal first light of LSST.

  15. Diagnosing transient ionization in dynamic events

    NASA Astrophysics Data System (ADS)

    Doyle, J. G.; Giunta, A.; Madjarska, M. S.; Summers, H.; O'Mullane, M.; Singh, A.

    2013-09-01

    Aims: The present study aims to provide a diagnostic line ratio that will enable the observer to determine whether a plasma is in a state of transient ionization. Methods: We use the Atomic Data and Analysis Structure (ADAS) to calculate line contribution functions for two lines, Si iv 1394 Å and O iv 1401 Å, formed in the solar transition region. The generalized collisional-radiative theory is used. It includes all radiative and electron collisional processes, except for photon-induced processes. State-resolved direct ionization and recombination to and from the next ionization stage are also taken into account. Results: For dynamic bursts with a decay time of a few seconds, the Si iv 1394 Å line can be enhanced by a factor of 2-4 in the first fraction of a second with the peak in the line contribution function occurring initially at a higher electron temperature due to transient ionization compared to ionization equilibrium conditions. On the other hand, the O iv 1401 Å does not show such any enhancement. Thus the ratio of these two lines, which can be observed with the Interface Region Imaging Spectrograph, can be used as a diagnostic of transient ionization. Conclusions: We show that simultaneous high-cadence observations of two lines formed in the solar transition region may be used as a direct diagnostic of whether the observed plasma is in transient ionization. The ratio of these two lines can change by a factor of four in a few seconds owing to transient ionization alone.

  16. Organization of extratropical transients during El Nino

    SciTech Connect

    Hoerling, M.P. ); Ting, Mingfang )

    1994-05-01

    Four observed El Nino-Southern Oscillation (ENSO) events are studied to determine the mechanisms responsible for the anomalous extratropical atmospheric circulation during northern winter. A parallel analysis of a GCM's response to El Nino is performed in order to assess if similar mechanisms are operative in the model atmosphere. The observed stationary wave anomalies over the Pacific/North American (PNA) region are found to be similar during the four winters despite appreciable differences in sea surface temperatures. The anomalous transient vorticity fluxes are remarkably robust over the North Pacific during each even, with an eastward extension of the climatological storm track leading to strong cyclonic forcing near 40[degrees]N, 150[degrees]W. This forcing is in phase with the seasonal mean Aleutian trough anomaly suggesting the important of eddy-mean flow interaction. By comparison, the intersample variability of the GCM response over the PNA region is found to exceed the observed inter-El Nino variability. This stems primarily from a large variability in the model's anomalous transients over the North Pacific. Further analysis reveals that extratropical vorticity transients are the primary mechanism maintaining the stationary wave anomalies over the PNA region during all four observed ENSO winters. In the case of the GCM, the organization of transient eddies is ill defined over the North Pacific, a behavior indicative of model error. A physical model is proposed to explain the robustness of the tropical controlling influence of the extratropical transients in nature. A simple equatorial Pacific heat source directly forces a tropical anticyclone whose phase relative to the climatological tropical anticyclone leads to an eastward extension of the subtropical jet stream. This mechanism appears to be equally effective for a heat source located either in the central or eastern Pacific basin. 36 refs., 14 figs.

  17. Entwicklung und methodische Verbesserung der Arbeitssicherheit in der Instandhaltung

    NASA Astrophysics Data System (ADS)

    Galinski, Marek

    Die Hüttenwerke Krupp Mannesmann gehören zu den führenden Stahlherstellern in Europa. Die Instandhaltung ist einerseits den Anlagen vor Ort zugeordnet, andererseits gibt es für werksweite bzw. spezielle Themen eine zentrale Instandhaltung. Die im Folgenden beschriebenen Methoden wurden für das gesamte Unternehmen entwickelt, jedoch je nach Organisationseinheit unterschiedlich adaptiert und unterschiedlich intensiv verfolgt. Die zentrale Instandhaltung hat insbesondere in den letzten 12 Jahren der Arbeitssicherheit einen hohen Stellenwert beigemessen, und hervorragende Ergebnisse erzielt. So ist die Unfallhäufigkeit in der zentralen Instandhaltung von ca. 30 anzeigepflichtigen Unfällen pro eine Million verfahrener Stunden vor ca. 15 Jahren auf Null in 2007 gesunken! In 2008 konnte dieses hervorragende Ergebnis gehalten werden. Zwei Jahre unfallfrei! Wer hätte das vor 15 Jahren gedacht? Der Schwerpunkt des Beitrags liegt auf der Erläuterung der Ansatzpunkte mit denen dieses Ergebnis erreicht wurde und der Darstellung der Methoden incl. der Anpassung an die veränderten Ansatzpunkte in den betroffenen Bereichen. Die beschriebenen Methoden sind in der zentralen Instandhaltung so angewendet worden.

  18. Ultrafast triggered transient energy storage by atomic layer deposition into porous silicon for integrated transient electronics.

    PubMed

    Douglas, Anna; Muralidharan, Nitin; Carter, Rachel; Share, Keith; Pint, Cary L

    2016-04-14

    Here we demonstrate the first on-chip silicon-integrated rechargeable transient power source based on atomic layer deposition (ALD) coating of vanadium oxide (VOx) into porous silicon. A stable specific capacitance above 20 F g(-1) is achieved until the device is triggered with alkaline solutions. Due to the rational design of the active VOx coating enabled by ALD, transience occurs through a rapid disabling step that occurs within seconds, followed by full dissolution of all active materials within 30 minutes of the initial trigger. This work demonstrates how engineered materials for energy storage can provide a basis for next-generation transient systems and highlights porous silicon as a versatile scaffold to integrate transient energy storage into transient electronics. PMID:26984120

  19. Exploring the transient sky: from surveys to simulations

    NASA Astrophysics Data System (ADS)

    Carbone, Dario

    2016-01-01

    The transient sky is very important to study the dynamics of the Universe on human timescales. Transient sources are seen in every band of the electromagnetic spectrum, from low radio frequencies to gamma-ray energies, and produced by nearby flare stars to cosmological gamma-ray bursts.We have performed a transient survey of four different fields with the LOw Frequency Array (LOFAR) at 150 MHz. LOFAR is a new generation radio interferometer which is observing at very low radio frequencies, a so far relatively unexplored frequency domain for transient searches. No credible transients were detected in our survey, but we were able to set stringent upper limits on the transient surface density using three new statistical methods. We also calculated the transient surface density as a function of the timescale of the transients, and established that the upper limits we can set vary up to two orders of magnitude for different timescales.We have explored the complex relation between flux density, timescale and transient surface density, and developed a simulation method to calculate the transient rate as a function of both the flux and the duration of transients for different shapes of their lightcurves and for a given observing strategy. This method is independent of the nature of transient sources, and the instrument or the frequency of the observations. Therefore, this provides a tool for transient surveys carried out by current and future observatories across the electromagnetic spectrum.

  20. Physik gestern und heute: Fragwürdiges beim Millikan-Versuch

    NASA Astrophysics Data System (ADS)

    Heering, Peter

    2006-09-01

    Robert A. Millikan erhielt 1923 als erster amerikanischer Physiker den Nobelpreis für Physik. Geehrt wurde er für seine Präzisionsmessungen zum Photoeffekt und zur experimentellen Bestimmung der elektrischen Elementarladung. Millikans Experimente zur Elementarladung sind auch heute noch ein Standardthema im schulischen Physikunterricht, gleichzeitig werfen sie aber eine Reihe von wissenschaftstheoretischen und ethisch relevanten Fragen auf.

  1. Quantenphysik und Gravitation Äquivalenzprinzip gilt auch für Quantenobjekte

    NASA Astrophysics Data System (ADS)

    Fray, Sebastian; Hänsch, Theodor W.; Weitz, Martin

    2005-03-01

    Gravitationstheorie und die Quantentheorie zu einer gemeinsamen Theorie vereinheitlichen, das ist eines der ungelösten Probleme der modernen Physik. Garchinger und Tübinger Wissenschaftler haben nun das Äquivalenzprinzip, einen Eckstein der Gravitationstheorie, mit der Methode der Atominterferometrie, die sich der quantenmechanischen Natur von Atomen bedient, überprüft.

  2. Blick in das kalte Weltall. Protosterne, Staubscheiben und schwarze Löcher.

    NASA Astrophysics Data System (ADS)

    Mezger, P. G.

    Contents: 1. Radioastronomie: Ein neues Fenster ins Weltall öffnet sich. Die Entwicklung der Radioastronomie. Vom Anfang der Welt: Der Urknall. Die Milchstraße und ihr infrarotes Bild. Sterne und interstellare Materie. Die Suche nach den Protosternen. Der Zentralbereich der Milchstraße. Im Zentrum der Milchstraße: Ein schwarzes Loch mit einer Akkretionsscheibe? 2. Der Wissenschaftsbetrieb.

  3. [COPD und Klangtherapie: Pilotstudie zur Wirksamkeit einer Behandlung mit Körpertambura bei COPD-Patienten].

    PubMed

    Hartwig, Bernhard; Schmidt, Stefan; Hartwig, Isabella

    2016-01-01

    Hintergrund: Erkrankungen der Atemorgane treten mit steigendem Alter öfter auf, nehmen weltweit zu und sind häufige Ursachen für Morbidität und Mortalität. In dieser Pilotstudie wurde der Frage nachgegangen, ob eine einmalige 10-minütige Behandlung mit einer Körpertambura eine signifikante und effektive Verbesserung der Lungenfunktion von Patienten mit chronisch-obstruktiver Lungenerkrankung (COPD; GOLD-Stadium A oder B) erbringen kann. Patienten und Methoden: 54 Probanden konnten je zur Hälfte in eine Behandlungsgruppe (Körpertambura) und eine aktive Kontrollgruppe (Atemtherapie) randomisiert werden. Eine Bestimmung der Lungenfunktionsmessparameter «Einsekundenkapazität» (FEV1) und «inspiratorische Vitalkapazität» (IVC) zu den Zeitpunkten T1 (Baseline), T2 (direkt nach Behandlung) und als Follow-up etwa 3 Wochen nach T1 (T3). Ergebnisse: Die Behandlungsgruppe zeigte sich der Kontrollgruppe in beiden Werten signifikant überlegen. Die Zeit-×-Gruppe-Interaktion (Varianzanalyse) ergab p = 0,001 (FEV1) bzw. p = 0,04 (IVC). Die Behandlungsgruppe zeigte bei beiden Werten eine Verbesserung von klinischer Relevanz. Schlussfolgerung: Diese Ergebnisse zeigen, dass die Klangbehandlung mittels einer Körpertambura - neben den schulmedizinischen, leitliniengerechten Therapien - eine zusätzliche, nebenwirkungsarme, aber durchaus klinisch wirksame Option für die Behandlung von COPD-Patienten darstellen kann, um deren Lebensqualität zu stabilisieren und zu verbessern. PMID:27606616

  4. Single Event Transients in Linear Integrated Circuits

    NASA Technical Reports Server (NTRS)

    Buchner, Stephen; McMorrow, Dale

    2005-01-01

    On November 5, 2001, a processor reset occurred on board the Microwave Anisotropy Probe (MAP), a NASA mission to measure the anisotropy of the microwave radiation left over from the Big Bang. The reset caused the spacecraft to enter a safehold mode from which it took several days to recover. Were that to happen regularly, the entire mission would be compromised, so it was important to find the cause of the reset and, if possible, to mitigate it. NASA assembled a team of engineers that included experts in radiation effects to tackle the problem. The first clue was the observation that the processor reset occurred during a solar event characterized by large increases in the proton and heavy ion fluxes emitted by the sun. To the radiation effects engineers on the team, this strongly suggested that particle radiation might be the culprit, particularly when it was discovered that the reset circuit contained three voltage comparators (LM139). Previous testing revealed that large voltage transients, or glitches appeared at the output of the LM139 when it was exposed to a beam of heavy ions [NI96]. The function of the reset circuit was to monitor the supply voltage and to issue a reset command to the processor should the voltage fall below a reference of 2.5 V [PO02]. Eventually, the team of engineers concluded that ionizing particle radiation from the solar event produced a negative voltage transient on the output of one of the LM139s sufficiently large to reset the processor on MAP. Fortunately, as of the end of 2004, only two such resets have occurred. The reset on MAP was not the first malfunction on a spacecraft attributed to a transient. That occurred shortly after the launch of NASA s TOPEX/Poseidon satellite in 1992. It was suspected, and later confirmed, that an anomaly in the Earth Sensor was caused by a transient in an operational amplifier (OP-15) [KO93]. Over the next few years, problems on TDRS, CASSINI, [PR02] SOHO [HA99,HA01] and TERRA were also attributed

  5. Spectroscopic Classifications of Optical Transients with Mayall/KOSMOS

    NASA Astrophysics Data System (ADS)

    Pan, Y.-C.; Miller, J.; Foley, R. J.; Jha, S. W.; Rest, A.; Scolnic, D.

    2016-04-01

    We report the following classifications of optical transients from spectroscopic observations with the KOSMOS on the Mayall telescope. Targets were supplied by the Pan-STARRS Survey for Transients (PSST).

  6. SPIRITS Discoveries of New Infrared Transients and Variables

    NASA Astrophysics Data System (ADS)

    Jencson, J. E.; Kasliwal, M. M.; Tinyanont, S.; Cao, Y.; Prince, T.; Lau, R. M.; Perley, D.; Masci, F.; Helou, G.; Armus, L.; Surace, J.; Dyk, S. D. Van; Cody, A.; Boyer, M. L.; Khan, R.; Bond, H. E.; Monson, A.; Bally, J.; Levesque, E.; Williams, R.; Whitelock, P. A.; Mohamed, S.; Gehrz, R. D.; Amodeo, S.; Shenoy, D.; Carlon, R.; Cass, A.; Corgan, D.; Dykhoff, D.; Faella, J.; Gburek, T.; Smith, N.; Cantiello, M.; Langer, N.; Ofek, E.; Johansson, J.; Parthasarathy, M.; Fox, O.; Hsiao, E.; Phillips, M.; Morrell, N.; Gonzalez, C.; Contreras, C.

    2016-04-01

    We report several recently discovered mid-infrared transients/strong variables found in the course of the Spitzer InfraRed Intensive Transients Survey (SPIRITS), using Spitzer Early Release Data (ATel #6644, #7929, #8688).

  7. Diagnostic Considerations in Patients Presenting with Transient Vision Loss.

    PubMed

    Jun, Bokkwan

    2016-01-01

    A complete history is essential for determining whether the underlying etiology of transient vision loss is from an ischemic or a nonischemic condition that originates in the eye or elsewhere. Ischemic transient vision loss constitutes a transient ischemic attack and requires a full work-up for ischemic stroke. If carotid artery stenosis is found, early intervention may improve the clinical outcome. This article highlights the diagnostic considerations in the evaluation of patients with transient vision loss. PMID:27039494

  8. Ultrafast triggered transient energy storage by atomic layer deposition into porous silicon for integrated transient electronics

    NASA Astrophysics Data System (ADS)

    Douglas, Anna; Muralidharan, Nitin; Carter, Rachel; Share, Keith; Pint, Cary L.

    2016-03-01

    Here we demonstrate the first on-chip silicon-integrated rechargeable transient power source based on atomic layer deposition (ALD) coating of vanadium oxide (VOx) into porous silicon. A stable specific capacitance above 20 F g-1 is achieved until the device is triggered with alkaline solutions. Due to the rational design of the active VOx coating enabled by ALD, transience occurs through a rapid disabling step that occurs within seconds, followed by full dissolution of all active materials within 30 minutes of the initial trigger. This work demonstrates how engineered materials for energy storage can provide a basis for next-generation transient systems and highlights porous silicon as a versatile scaffold to integrate transient energy storage into transient electronics.Here we demonstrate the first on-chip silicon-integrated rechargeable transient power source based on atomic layer deposition (ALD) coating of vanadium oxide (VOx) into porous silicon. A stable specific capacitance above 20 F g-1 is achieved until the device is triggered with alkaline solutions. Due to the rational design of the active VOx coating enabled by ALD, transience occurs through a rapid disabling step that occurs within seconds, followed by full dissolution of all active materials within 30 minutes of the initial trigger. This work demonstrates how engineered materials for energy storage can provide a basis for next-generation transient systems and highlights porous silicon as a versatile scaffold to integrate transient energy storage into transient electronics. Electronic supplementary information (ESI) available: (i) Experimental details for ALD and material fabrication, ellipsometry film thickness, preparation of gel electrolyte and separator, details for electrochemical measurements, HRTEM image of VOx coated porous silicon, Raman spectroscopy for VOx as-deposited as well as annealed in air for 1 hour at 450 °C, SEM and transient behavior dissolution tests of uniformly coated VOx on

  9. Transient One-dimensional Pipe Flow Analyzer

    1986-04-08

    TOPAZ-SNLL, the Transient One- dimensional Pipe flow AnalyZer code, is a user-friendly computer program for modeling the heat transfer, fluid mechanics, and thermodynamics of multi-species gas transfer in arbitrary arrangements of pipes, valves, vessels, and flow branches. Although the flow conservation equations are assumed to be one-dimensional and transient, multidimensional features of internal fluid flow and heat transfer may be accounted for using the available quasi-steady flow correlations (e.g., Moody friction factor correlation and variousmore » form loss and heat transfer correlations). Users may also model the effects of moving system boundaries such as pistons, diaphragms, and bladders. The features of fully compressible flow are modeled, including the propagation of shocks and rarefaction waves, as well as the establishment of multiple choke points along the flow path.« less

  10. Biocatalytic Pathway Selection in Transient Tripeptide Nanostructures.

    PubMed

    Pappas, Charalampos G; Sasselli, Ivan R; Ulijn, Rein V

    2015-07-01

    Structural adaption in living systems is achieved by competing catalytic pathways that drive assembly and disassembly of molecular components under the influence of chemical fuels. We report on a simple mimic of such a system that displays transient, sequence-dependent formation of supramolecular nanostructures based on biocatalytic formation and hydrolysis of self-assembling tripeptides. The systems are catalyzed by α-chymotrypsin and driven by hydrolysis of dipeptide aspartyl-phenylalanine-methyl ester (the sweetener aspartame, DF-OMe). We observed switch-like pathway selection, with the kinetics and consequent lifetime of transient nanostructures controlled by the peptide sequence. In direct competition, kinetic (rather than thermodynamic) component selection is observed. PMID:26014441

  11. Transient sexual precocity and ovarian cysts.

    PubMed Central

    Lyon, A J; De Bruyn, R; Grant, D B

    1985-01-01

    Nine girls presenting under the age of 7 years with unsustained sexual precocity are described. Large ovarian cysts were detected by ultrasound in three and laparotomy in one. In two girls the symptoms resolved after surgical removal of the cyst; the other seven had spontaneous remission of symptoms, but in two of these transient breast development and bleeding recurred: further ovarian cyst formation was found in one of these patients. Endocrine studies performed before resolution of the cysts showed raised plasma oestradiol concentrations (64 to 440 pmol/l) in three girls and no appreciable rise in plasma luteinising hormone after gonadotrophin releasing hormone stimulation in two. We conclude that ovarian cyst formation with spontaneous resolution may cause transient sexual precocity in girls, and that ultrasound examination is an effective means of diagnosing and following these patients. Images Figure p820-b PMID:3901933

  12. Zero-gravity transient thermal mixing simulation

    NASA Technical Reports Server (NTRS)

    Lands, J. F., Jr.; Ried, R. C., Jr.

    1971-01-01

    The experimental program described is an outgrowth of independent investigations into alternate redesign concepts for the Apollo SM cryogenic oxygen storage system. The experiments were continued, after the redesign was established, to provide physical insight into transient thermal mixing in zero-gravity and to aid in the characterization of the system performance in flight. Zero-gravity heat transfer and fluid mixing were simulated experimentally through an analogy between unsteady heat conduction and species diffusion. To further support numerical analyses of the cryogenic oxygen storage system, the experimental investigation was extended to include a cubical tank geometry, representative of existing numerical models. In general, the transient flow patterns in the cubical tank are far more complex than those of the spherical tank and the extent of fluid mixing is significantly greater but less repeatable.

  13. On Transients in Detached Bridgman Growth

    NASA Technical Reports Server (NTRS)

    Mazuruk, K.; Volz, M. P.

    2011-01-01

    In detached Bridgman growth, a gap exists between the growing crystal and the crucible wall. According to crystal shape stability theory, only specific gap widths will be dynamically stable. Beginning with a crystal diameter that differs from stable conditions, the transient crystal growth process is analyzed. The transient shapes are calculated assuming that the growth angle is constant. Anisotropy and dynamic contact angle effects are considered. In microgravity, dynamic stability depends only on capillary effects and is decoupled from heat transfer. However, heat transfer will influence the crystal-melt interface shape. The local angles and the crystal-melt-vapor triple junction are analyzed and the applicability of the Herring formula is discussed. A potential microgravity experiment is proposed which would enhance our understanding of the detached growth dynamic stability problem.

  14. Transient failure behavior of HT9

    SciTech Connect

    Huang, F.H.

    1994-07-01

    Alloy HT9 has-been chosen as candidate materials for fast and fusion reactor applications because the.material exhibits excellent resistance to void swelling. However, ferritic alloys are known to undergo a ductile-brittle transition as the test temperature is decreased. This inherent problem has limited their applications to reactor component materials subjected to low neutron exposures. Despite the ductile-brittle transition problem, results show that the materials exhibit superior resistance to fracture under very high neutron fluences at irradiation temperatures above 380C. Results also show that the transient behavior for HT9 cladding specimens taken from the fuel column region and cladding taken from outside the fuel column or unirradiated cladding are the same. HT9 cladding maintained its transient strength with irradiation to a fluence of 9 {times} 10{sup 22} n/cm{sup 2} (E > 0.1 MeV).

  15. Transient Growth in Internal Solitary Waves

    NASA Astrophysics Data System (ADS)

    Helfrich, Karl; Passaggia, Pierre-Yves; White, Brian

    2015-11-01

    Internal solitary waves of large amplitude are common in the atmosphere and ocean and play an important role in mixing and transport. While these waves can propagate over long distances, observations suggest they are susceptible to a range of instabilities, which promote breakdown, overturning, and mixing. To gain insight into these instabilities, we consider the optimal transient growth of a family of solitary waves, which are solutions to the Dubreil-Jacotin-Long (DJL) equation for increasing phase speed and varying background stratification. Optimal initial disturbances are computed by means of direct-adjoint iterations of the Navier-Stokes system in the Boussinesq approximation. The most amplified disturbances resemble Kelvin-Helmholtz instabilities and are localized near the bottom of the wave, where the Richardson number is minimum, and are maximized for short time horizons. The optimal transient growth of these perturbations is shown to increase with the phase speed. Implications for breakdown and mixing will be discussed.

  16. A physically transient form of silicon electronics.

    PubMed

    Hwang, Suk-Won; Tao, Hu; Kim, Dae-Hyeong; Cheng, Huanyu; Song, Jun-Kyul; Rill, Elliott; Brenckle, Mark A; Panilaitis, Bruce; Won, Sang Min; Kim, Yun-Soung; Song, Young Min; Yu, Ki Jun; Ameen, Abid; Li, Rui; Su, Yewang; Yang, Miaomiao; Kaplan, David L; Zakin, Mitchell R; Slepian, Marvin J; Huang, Yonggang; Omenetto, Fiorenzo G; Rogers, John A

    2012-09-28

    A remarkable feature of modern silicon electronics is its ability to remain physically invariant, almost indefinitely for practical purposes. Although this characteristic is a hallmark of applications of integrated circuits that exist today, there might be opportunities for systems that offer the opposite behavior, such as implantable devices that function for medically useful time frames but then completely disappear via resorption by the body. We report a set of materials, manufacturing schemes, device components, and theoretical design tools for a silicon-based complementary metal oxide semiconductor (CMOS) technology that has this type of transient behavior, together with integrated sensors, actuators, power supply systems, and wireless control strategies. An implantable transient device that acts as a programmable nonantibiotic bacteriocide provides a system-level example.

  17. Deflagration transient study of the CIF incinerator

    SciTech Connect

    Hang, T.

    2000-01-03

    The Consolidated Incineration Facility (CIF) treats solid and liquid RCRA hazardous and mixed wastes generated at the Savannah River Site (SRS). The transient responses of the CIF system to a deflagration, caused by an accidental charge of a modest quantity of solvent (e.g. toluene) into the rotary kiln, were a major safety concern. Using a dynamic computer model, a study was conducted to analyze the transient system responses to the rapid temperature and pressure surge in the kiln. The objective of the study was to determined the maximum pressure, temperature, and gas flow rate in each CIF component (rotary kiln, secondary combustion chamber, quencher, scrubber/cyclone, mist eliminator, reheaters, HEPAs, and ID fans). The resulting data provided a basis for the subsequent structural analysis. This paper will describe the CIF deflagration study in some detail, and present the results of the simulation scenarios.

  18. Transient phenomena in rotary-kiln incineration

    SciTech Connect

    Linak, W.P.; Kilgroe, J.D.; McSorley, J.A.; Wendt, J.O.L.; Dunn, J.E.

    1989-01-01

    This paper describes results of an ongoing experimental investigation at the U.S. EPA into the waste properties and kiln parameters that determine both the instantaneous intensity and the total magnitude of transient puffs leaving the kiln. (NOTE: The batch introduction of waste-filled drums or containers into practical rotary-kiln incinerators can lead to transient overcharging conditions which, for brevity, are here denoted as 'puffs.') The experimental apparatus utilized was a 73-kW laboratory rotary-kiln simulator. Surrogate solid wastes (plastic rods) and surrogate liquid wastes (on corncob sorbent in cardboard containers) were investigated. A statistically designed parametric study was used to determine the extent to which waste and kiln variables (e.g., charge mass, charge surface area, charge composition, kiln temperature, and kiln rotation speed) affected the intensity (hydrocarbon peak height) and magnitude (hydrocarbon peak area) of puffs.

  19. Spectral Kurtosis statistics of transient signals

    NASA Astrophysics Data System (ADS)

    Nita, G. M.

    2016-05-01

    We obtain analytical approximations for the expectation and variance of the Spectral Kurtosis estimator in the case of Gaussian and coherent transient time domain signals mixed with a quasi-stationary Gaussian background, which are suitable for practical estimations of their signal-to-noise ratio and duty-cycle relative to the instrumental integration time. We validate these analytical approximations by means of numerical simulations and demonstrate that such estimates are affected by statistical uncertainties that, for a suitable choice of the integration time, may not exceed a few per cent. Based on these analytical results, we suggest a multiscale Spectral Kurtosis spectrometer design optimized for real-time detection of transient signals, automatic discrimination based on their statistical signature, and measurement of their properties.

  20. Steady and transient regimes in hydropower plants

    NASA Astrophysics Data System (ADS)

    Gajic, A.

    2013-12-01

    Hydropower plant that has been in operation for about 30 years has to be reconstructed. They have already installed 12 Kaplan turbines, the largest in the world at that time. The existing CAM relationship was determined based on hydraulic model tests and checked by efficiency on-site tests. It was also tested based on turbine bearing vibrations. In order to discover vibrations and long cracks on stay vanes detailed on-site measurements were performed. Influence of the modification of the trailing edges on the dynamic stresses of the stay vanes is also shown. In order to improve power output transient regimes were analyzed, both experimentally and numerically. Reversible hydropower plant, a pioneer in Europe since it was the first Pump storage power plant constructed with the highest head pump-turbines in the world. Analyses of transient regimes discover some problems with S-shaped characteristics coupled with non-symmetrical penstock.

  1. Characterization of highly transient EUV emitting discharges

    NASA Astrophysics Data System (ADS)

    van der Mullen, Joost; Kieft, Erik; Broks, Bart

    2006-07-01

    The method of disturbed Bilateral Relations (dBR) is used to characterize highly transient plasmas that are used for the generation of Extreme Ultra Violet (EUV), i.e. radiation with a wavelength around 13.5 nm. This dBR method relates equilibrium disturbing to equilibrium restoring processes and follows the degree of equilibrium departure from the global down to the elementary plasma-level. The study gives global values of the electron density and electron temperature. Moreover, it gives a method to construct the atomic state distribution function (ASDF). This ASDF, which is responsible for the spectrum generated by the discharge, is found to be far from equilibrium. There are two reasons for this: first, systems with high charge numbers radiate strongly, second the highly transient behaviour makes that the distribution over the various ionization stages lags behind the temperature evolution.

  2. Transient One-dimensional Pipe Flow Analyzer

    SciTech Connect

    1986-04-08

    TOPAZ-SNLL, the Transient One- dimensional Pipe flow AnalyZer code, is a user-friendly computer program for modeling the heat transfer, fluid mechanics, and thermodynamics of multi-species gas transfer in arbitrary arrangements of pipes, valves, vessels, and flow branches. Although the flow conservation equations are assumed to be one-dimensional and transient, multidimensional features of internal fluid flow and heat transfer may be accounted for using the available quasi-steady flow correlations (e.g., Moody friction factor correlation and various form loss and heat transfer correlations). Users may also model the effects of moving system boundaries such as pistons, diaphragms, and bladders. The features of fully compressible flow are modeled, including the propagation of shocks and rarefaction waves, as well as the establishment of multiple choke points along the flow path.

  3. Transient expression assays in tobacco protoplasts.

    PubMed

    Vanden Bossche, Robin; Demedts, Brecht; Vanderhaeghen, Rudy; Goossens, Alain

    2013-01-01

    The sequence information generated through genome and transcriptome analysis from plant tissues has reached unprecedented sizes. Sequence homology-based annotations may provide hints for the possible function and roles of particular plant genes, but the functional annotation remains nonexistent or incomplete for many of them. To discover gene functions, transient expression assays are a valuable tool because they can be done more rapidly and at a higher scale than generating stably transformed tissues. Here, we describe a transient expression assay in protoplasts derived from suspension cells of tobacco (Nicotiana tabacum) for the study of the transactivation capacities of transcription factors. To enhance throughput and reproducibility, this method can be automated, allowing medium-throughput screening of interactions between large compendia of potential transcription factors and gene promoters.

  4. Transient behavior in the Lorenz model

    NASA Astrophysics Data System (ADS)

    Kravtsov, S.; Sugiyama, N.; Tsonis, A. A.

    2014-12-01

    Dynamical systems like the one described by the three-variable Lorenz model may serve as metaphors for complexity in nature. When natural systems are perturbed by external forcing factors, they tend to relax back to their equilibrium conditions after the forcing has shut off. Here we investigate the behavior of such transients in the Lorenz model by studying its trajectories initialized far away from the asymptotic attractor. Perhaps somewhat surprisingly, these transient trajectories exhibit complex routes and, among other things, sensitivity to initial conditions akin to that of the asymptotic behavior on the attractor. Thus, similar extreme events may lead to widely different variations before the perturbed system returns back to its statistical equilibrium.

  5. Time Transient Effects in Heterogeneous Permselective Systems

    NASA Astrophysics Data System (ADS)

    Green, Yoav; Park, Sinwook; Yossifon, Gilad

    2015-03-01

    The passage of an electric current through a permselective medium (membranes/nanochannels) under an applied electric field is characterized by the formation of ionic concentration gradients which result in regions of depleted and enriched ionic concentration at opposite ends of the medium, i.e. concentration polarization (CP). In this work, we study the time-transient behavior of the concentration and electric potential distributions in a realistic two dimensional and three layered system (i.e. microchannel-permselective medium-microchannel device). We provide an analytical solution for the concentration under the simplifying assumptions of local-electroneutrality, ideal permselectivity and negligible convection while the electric potential is solved numerically. It is shown that time transient effects occur over the diffusive time scale until steady-state is achieved. The numerical steady state solution is compared with previous analytical results and good quantitative behavior is observed.

  6. Transient Diabetes Insipidus Following Cardiopulmonary Bypass.

    PubMed

    Ekim, Meral; Ekim, Hasan; Yilmaz, Yunus Keser; Bolat, Ali

    2015-04-01

    Diabetes insipidus (DI) results from inadequate output of Antidiuretic Hormone (ADH) from the pituitary gland (central DI) or the inability of the kidney tubules to respond to ADH (nephrogenic DI). ADH is an octapeptide produced in the supraoptic and paraventricular nuclei of the hypothalamus and stored in the posterior lobe of the pituitary gland. Cardiopulmonary Bypass (CPB) has been shown to cause a six-fold increased circulating ADH levels 12 hours after surgery. However, in some cases, ADH release may be transiently suppressed due to cardioplegia (cardiac standstill) or CPB leading to DI. We present the postoperative course of a 60-year-old man who developed transient DI after CPB. He was successfully treated by applying nasal desmopressin therapy. Relevant biochemical parameters should be monitored closely in patients who produce excessive urine after open heart surgery.

  7. Transient phenomena in compressor stations during surge

    SciTech Connect

    Botros, K.K. )

    1994-01-01

    Transient phenomena are generally inherent in the operation of compressor stations: These are either fast or slow transients. A model describing the governing equation for the gas dynamics, control system, compressor and turbine shaft inertias has been developed. The effect of these inertias is manifested by an example of a compressor station operating near the surge control line. Another example deals with a station that has a cooler placed in the recycle path. This alters the rate at which the compressor shaft decelerates upon shutdown and may cause backward spinning depending on the relative magnitude of the shaft inertia with respect to the cooler volume. Backward spinning of compressor shaft has detrimental effects on dry seals and is undesirable. It was found that by keeping the recycle value closed upon shutdown, the rate of shaft deceleration will be reduced.

  8. Nonlinear transient analysis via energy minimization

    NASA Technical Reports Server (NTRS)

    Kamat, M. P.; Knight, N. F., Jr.

    1978-01-01

    The formulation basis for nonlinear transient analysis of finite element models of structures using energy minimization is provided. Geometric and material nonlinearities are included. The development is restricted to simple one and two dimensional finite elements which are regarded as being the basic elements for modeling full aircraft-like structures under crash conditions. The results indicate the effectiveness of the technique as a viable tool for this purpose.

  9. A new mechanism for lunar transient phenomena

    SciTech Connect

    Zito, R.R. )

    1989-12-01

    Lunar transient phenomena, which are changes in lunar surface brightness observed over the course of four centuries, are presently characterized by a novel mechanism in which electrodynamic effects associated with rock fracturing could account for the sporadic optical pulses noted near specific lunar features. It is suggested that only mild seismic activity, or perhaps thermal cracking, may be required for the activation of the proposed mechanism. 22 refs.

  10. Sprites, elf transients, and positive ground strokes

    SciTech Connect

    Boccippio, D.J.; Boldi, R.; Williams, E.R.

    1995-08-25

    In two summertime mesoscale convective systems (MCSs), mesospheric optical sprite phenomena were often coincident with both large-amplitude positive cloud-to-ground lightning and transient Schumann resonance excitations of the entire Earth-ionosphere cavity. These observations, together with earlier studies of MCS electrification, suggest that sprites are triggered when the rapid removal of large quantities of positive charge from an areally extensive charge layer stresses the mesosphere to dielectric breakdown. 46 refs., 7 figs., 1 tab.

  11. Monitoring transients in low inductance circuits

    DOEpatents

    Guilford, R.P.; Rosborough, J.R.

    1985-10-21

    The instant invention relates to methods of and apparatus for monitoring transients in low inductance circuits and to a probe utilized to practice said method and apparatus. More particularly, the instant invention relates to methods of and apparatus for monitoring low inductance circuits, wherein the low inductance circuits include a pair of flat cable transmission lines. The instant invention is further directed to a probe for use in monitoring pairs of flat cable transmission lines.

  12. ATLAS discovery of an optical transient

    NASA Astrophysics Data System (ADS)

    Tonry, J.; Denneau, L.; Stalder, B.; Heinze, A.; Sherstyuk, A.; Rest, A.; Smith, K. W.; Smartt, S. J.

    2016-08-01

    We report the following transient found by the ATLAS survey (see Tonry et al. ATel #8680). ATLAS is a twin 0.5m telescope system on Haleakala and Mauna Loa. The first unit is operational on Haleakala is robotically surveying the sky. Two filters are used, cyan and orange (denoted c and o, all mags in AB system), more information is on http://www.fallingstar.com.

  13. Reactivity Transients in Nuclear Research Reactors

    SciTech Connect

    2015-01-01

    Version 01 AIREMOD-RR is a point kinetics code which can simulate fast transients in nuclear research reactor cores. It can also be used for theoretical reactor dynamics studies. It is used for research reactor kinetic analysis and provides a point neutron kinetic capability. The thermal hydraulic behavior is governed by a one-dimensional heat balance equation. The calculations are restricted to a single equivalent unit cell which consists of fuel, clad and coolant.

  14. Validity of Darcy's law under transient conditions

    USGS Publications Warehouse

    Mongan, C.E.

    1985-01-01

    Darcy 's Law, which describes fluid flow through porous materials, was developed for steady flow conditions. The validity of applying this law to transient flows has been mathematically verified for most ground-water flow conditions. The verification was accomplished through application of Hankel transforms to linearized Navier-Stokes equations which described flow in a small diameter cylindrical tube. The tube was chosen to represent a single pore in a porous medium. (USGS)

  15. Tracking transient temperatures with liquid crystals

    NASA Technical Reports Server (NTRS)

    Grodzka, P. G.; Facemire, B. R.

    1975-01-01

    The theoretical basis of the use of the liquid crystal technique to obtain transient thermal data is discussed. Results of calibrations of liquid crystal temperature sensors are given. The effects of crystal aging, lighting effects, observer bias, etc., on accuracy are discussed. The sensitivity of liquid crystal tapes as sensors of dynamic temperature changes is quite high. The accuracy of the technique is determined primarily by the type of calibration apparatus used.

  16. 40 CFR 86.1333-90 - Transient test cycle generation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 20 2013-07-01 2013-07-01 false Transient test cycle generation. 86... Procedures § 86.1333-90 Transient test cycle generation. (a) The heavy-duty transient engine cycles for Otto... question must be used. The generation of the maximum torque curve is described in § 86.1332. (3) The...

  17. 40 CFR 86.1333-90 - Transient test cycle generation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 19 2011-07-01 2011-07-01 false Transient test cycle generation. 86... Procedures § 86.1333-90 Transient test cycle generation. (a) The heavy-duty transient engine cycles for Otto... question must be used. The generation of the maximum torque curve is described in § 86.1332. (3) The...

  18. 40 CFR 86.1333-90 - Transient test cycle generation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 20 2012-07-01 2012-07-01 false Transient test cycle generation. 86... Procedures § 86.1333-90 Transient test cycle generation. (a) The heavy-duty transient engine cycles for Otto... question must be used. The generation of the maximum torque curve is described in § 86.1332. (3) The...

  19. 40 CFR 86.1333-90 - Transient test cycle generation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Transient test cycle generation. 86... Procedures § 86.1333-90 Transient test cycle generation. (a) The heavy-duty transient engine cycles for Otto... question must be used. The generation of the maximum torque curve is described in § 86.1332. (3) The...

  20. PSST discovery of a faint transient in NGC 6012

    NASA Astrophysics Data System (ADS)

    Smith, K. W.; Wright, D.; Smartt, S. J.; Young, D. R.; Huber, M.; Chambers, K. C.; Flewelling, H.; Willman, M.; Primak, N.; Schultz, A.; Gibson, B.; Magnier, E.; Waters, C.; Tonry, J.; Wainscoat, R. J.; Foley, R. J.; Jha, S. W.; Rest, A.; Scolnic, D.

    2016-06-01

    A transient object has been discovered near NGC 6012 as part of the Pan-STARRS Survey for Transients (PSST). Information on all objects discovered by the Pan-STARRS Survey for Transients is available at http://star.pst.qub.ac.uk/ps1threepi/ (see Huber et al. ATel #7153).

  1. Defect energy levels from current transient recording

    NASA Astrophysics Data System (ADS)

    Momayezi, Michael

    1991-07-01

    Silicon detectors are widely used in high energy physics in vertexing and calorimetry applications. The radiative environment will introduce defects with energy levels in the bandgap into the crystals. At the high levels of radiation present at proton accelerators the defect concentration will easily approach or exceed the doping concentration of the usual high ohmic material. DLTS, the most common technique for defect characterization is known to fail under these conditions. To study heavy radiation damage in silicon detectors a new method has been developed. Using a DLTS-like pulser setup, the current transient from trap emptying is recorded on a fast digital scope being read out by a microcomputer. This is repeatedly done during a temperature scan. The time integral of the current transient equals the number of traps present and the activation enthalpy is found from the temperature dependence of the emission life time. If there is more than one energy level present the individual components may be extracted by a fitting procedure from the then multiexponential current transient. The sensitivity reached so far is, noise and systematics considered, ˜10 9 traps. Lifetimes between 5 μs and 5 ms are covered.

  2. Transient Thermoelectric Solution Employing Green's Functions

    NASA Technical Reports Server (NTRS)

    Mackey, Jon; Sehirlioglu, Alp; Dynys, Fred

    2014-01-01

    The study works to formulate convenient solutions to the problem of a thermoelectric couple operating under a time varying condition. Transient operation of a thermoelectric will become increasingly common as thermoelectric technology permits applications in an increasing number of uses. A number of terrestrial applications, in contrast to steady-state space applications, can subject devices to time varying conditions. For instance thermoelectrics can be exposed to transient conditions in the automotive industry depending on engine system dynamics along with factors like driving style. In an effort to generalize the thermoelectric solution a Greens function method is used, so that arbitrary time varying boundary and initial conditions may be applied to the system without reformulation. The solution demonstrates that in thermoelectric applications of a transient nature additional factors must be taken into account and optimized. For instance, the materials specific heat and density become critical parameters in addition to the thermal mass of a heat sink or the details of the thermal profile, such as oscillating frequency. The calculations can yield the optimum operating conditions to maximize power output andor efficiency for a given type of device.

  3. Aeroelastic Modeling of a Nozzle Startup Transient

    NASA Technical Reports Server (NTRS)

    Wang, Ten-See; Zhao, Xiang; Zhang, Sijun; Chen, Yen-Sen

    2014-01-01

    Lateral nozzle forces are known to cause severe structural damage to any new rocket engine in development during test. While three-dimensional, transient, turbulent, chemically reacting computational fluid dynamics methodology has been demonstrated to capture major side load physics with rigid nozzles, hot-fire tests often show nozzle structure deformation during major side load events, leading to structural damages if structural strengthening measures were not taken. The modeling picture is incomplete without the capability to address the two-way responses between the structure and fluid. The objective of this study is to develop a tightly coupled aeroelastic modeling algorithm by implementing the necessary structural dynamics component into an anchored computational fluid dynamics methodology. The computational fluid dynamics component is based on an unstructured-grid, pressure-based computational fluid dynamics formulation, while the computational structural dynamics component is developed under the framework of modal analysis. Transient aeroelastic nozzle startup analyses at sea level were performed, and the computed transient nozzle fluid-structure interaction physics presented,

  4. Bounds on Transient Instability for Complex Ecosystems

    PubMed Central

    2016-01-01

    Stability is a desirable property of complex ecosystems. If a community of interacting species is at a stable equilibrium point then it is able to withstand small perturbations to component species’ abundances without suffering adverse effects. In ecology, the Jacobian matrix evaluated at an equilibrium point is known as the community matrix, which describes the population dynamics of interacting species. A system’s asymptotic short- and long-term behaviour can be determined from eigenvalues derived from the community matrix. Here we use results from the theory of pseudospectra to describe intermediate, transient dynamics. We first recover the established result that the transition from stable to unstable dynamics includes a region of ‘transient instability’, where the effect of a small perturbation to species’ abundances—to the population vector—is amplified before ultimately decaying. Then we show that the shift from stability to transient instability can be affected by uncertainty in, or small changes to, entries in the community matrix, and determine lower and upper bounds to the maximum amplitude of perturbations to the population vector. Of five different types of community matrix, we find that amplification is least severe when predator-prey interactions dominate. This analysis is relevant to other systems whose dynamics can be expressed in terms of the Jacobian matrix. PMID:27327511

  5. Transient mixed chimerism for allograft tolerance.

    PubMed

    Oura, Tetsu; Hotta, Kiyohiko; Cosimi, A B; Kawai, Tatsuo

    2015-04-01

    Mixed chimerism discovered in Freemartin cattle by Ray Owen 70 years ago paved the way for research on immune tolerance. Since his discovery, significant progress has been made in the effort to induce allograft tolerance via mixed chimerism in various murine models. However, induction of persistent mixed chimerism has proved to be extremely difficult in major histocompatibility complex mismatched humans. Chimerism induced in humans tends to either disappear or convert to full donor chimerism, depending on the intensity of the conditioning regimen. Nevertheless, our studies in both NHPs and humans have clearly demonstrated that renal allograft tolerance can be induced by transient mixed chimerism. Our studies have shown that solid organ allograft tolerance via transient mixed chimerism 1) requires induction of multilineage hematologic chimerism, 2) depends on peripheral regulatory mechanisms, rather than thymic deletion, for long-term maintenance, 3) is organ specific (kidney and lung but not heart allograft tolerance are feasible). A major advantage of tolerance induction via transient mixed chimerism is exclusion of the risk of graft-versus-host disease. Our ongoing studies are directed toward improving the consistency of tolerance induction, reducing the morbidity of the conditioning regimen, substituting clinically available agents, such as Belatacept for the now unavailable anti-CD2 monoclonal antibody, and extending the protocol to recipients of deceased donor allografts.

  6. Transient eddies in the MACDA Mars reanalysis

    NASA Astrophysics Data System (ADS)

    Mooring, Todd A.; Wilson, R. John

    2015-10-01

    We present a survey of the transient eddy activity in the Mars Analysis Correction Data Assimilation (MACDA) reanalysis. The spatial structure and propagation characteristics of the eddies are emphasized. Band-pass-filtered variance and covariance fields are found to be zonally modulated, indicating a longitude dependence of the typical amplitudes of Martian transient eddies. Considerable repeatability of the eddy field spatial structures is found across Mars years, including a roughly wave number 3 pattern of low-level eddy meridional temperature transport (v'T'¯) in the northern hemisphere that is evident before and after winter solstice and a possible tendency for northern hemisphere eddy kinetic energy maxima to be located above low-lying areas. Southern hemisphere eddy fields tend to feature two local maxima, one roughly south of Tharsis and the other associated with Hellas. Eddies are weakened near winter solstice in both hemispheres and were generally weakened in the northern hemisphere during the 2001 (Mars year 25) global dust storm, albeit with little change in spatial patterns. Because the transient eddies propagate in space, we also used a teleconnection map-based technique to estimate their phase velocities. Eddy propagation at the surface is found to follow topography, a phenomenon less evident at higher altitude. Possible physical mechanisms underlying the documented eddy phenomena are discussed.

  7. Coupling analysis of transient cardiovascular dynamics.

    PubMed

    Müller, Andreas; Riedl, Maik; Penzel, Thomas; Bonnemeier, Hendrik; Kurths, Jürgen; Wessel, Niels

    2013-04-01

    The analysis of effects from coupling in and between systems is important in data-driven investigations as practiced in many scientific fields. It allows deeper insights into the mechanisms of interaction emerging among individual smaller systems when forming complex systems as in the human circulatory system. For systems featuring various regimes, usually only the epochs before and after a transition between different regimes are analyzed, although relevant information might be hidden within these transitions. Transient behavior of cardiovascular variables may emerge, on the one hand, from the recovery of the system after a severe disturbance or, on the other hand, from adaptive behavior throughout changes of states. It contains important information about the processes involved and the relations between state variables such as heart rate, blood pressure, and respiration. Therefore, we apply an ensemble approach to extend the method of symbolic coupling traces to time-variant coupling analysis. These new ensemble symbolic coupling traces are capable of determining coupling direction, strength, and time offset τ from transient dynamics in multivariate cardiovascular data. We use this method to analyze data recorded during an orthostatic test to reveal a transient structure that cannot be detected by classic methods.

  8. Transient amorphous calcium phosphate in forming enamel.

    PubMed

    Beniash, Elia; Metzler, Rebecca A; Lam, Raymond S K; Gilbert, P U P A

    2009-05-01

    Enamel, the hardest tissue in the body, begins as a three-dimensional network of nanometer size mineral particles, suspended in a protein gel. This mineral network serves as a template for mature enamel formation. To further understand the mechanisms of enamel formation we characterized the forming enamel mineral at an early secretory stage using X-ray absorption near-edge structure (XANES) spectromicroscopy, transmission electron microscopy (TEM), FTIR microspectroscopy and polarized light microscopy. We show that the newly formed enamel mineral is amorphous calcium phosphate (ACP), which eventually transforms into apatitic crystals. Interestingly, the size, shape and spatial organization of these amorphous mineral particles and older crystals are essentially the same, indicating that the mineral morphology and organization in enamel is determined prior to its crystallization. Mineralization via transient amorphous phases has been previously reported in chiton teeth, mollusk shells, echinoderm spicules and spines, and recent reports strongly suggest the presence of transient amorphous mineral in forming vertebrate bones. The present finding of transient ACP in murine tooth enamel suggests that this strategy might be universal. PMID:19217943

  9. Experimental Investigation of Transient Sublimator Performance

    NASA Technical Reports Server (NTRS)

    Sheth, Rubik B.; Stephan, Ryan A.; Leimkuehler, Thomas O.

    2012-01-01

    Sublimators have been used as heat rejection devices for a variety of space applications including the Apollo Lunar Module and the Extravehicular Mobility Unit (EMU). Sublimators typically operate with steady-state feedwater utilization at or near 100%. However, sublimators are currently being considered for operations in a cyclical topping mode, which represents a new mode of operation for sublimators. Sublimators can be used as a supplemental heat rejection device during mission phases where the environmental temperature or heat rejection requirement changes rapidly. This scenario may occur during low lunar orbit, low earth orbit, or other planetary orbits. In these mission phases, the need for supplemental heat rejection will vary between zero and some fraction of the overall heat load. In particular, supplemental heat rejection is required for the portion of the orbit where the radiative sink temperature exceeds the system setpoint temperature. This paper will describe the effects of these transient starts and stops on the feedwater utilization during various feedwater timing scenarios. Experimental data from various scenarios is analyzed to investigate feedwater consumption efficiency under the cyclical conditions. Start up utilization tests were conducted to better understand the transient performance. This paper also provides recommendations for future sublimator design and transient operation.

  10. Transient absolute robustness in stochastic biochemical networks.

    PubMed

    Enciso, German A

    2016-08-01

    Absolute robustness allows biochemical networks to sustain a consistent steady-state output in the face of protein concentration variability from cell to cell. This property is structural and can be determined from the topology of the network alone regardless of rate parameters. An important question regarding these systems is the effect of discrete biochemical noise in the dynamical behaviour. In this paper, a variable freezing technique is developed to show that under mild hypotheses the corresponding stochastic system has a transiently robust behaviour. Specifically, after finite time the distribution of the output approximates a Poisson distribution, centred around the deterministic mean. The approximation becomes increasingly accurate, and it holds for increasingly long finite times, as the total protein concentrations grow to infinity. In particular, the stochastic system retains a transient, absolutely robust behaviour corresponding to the deterministic case. This result contrasts with the long-term dynamics of the stochastic system, which eventually must undergo an extinction event that eliminates robustness and is completely different from the deterministic dynamics. The transiently robust behaviour may be sufficient to carry out many forms of robust signal transduction and cellular decision-making in cellular organisms. PMID:27581485

  11. Transient Clumps in Saturn's F Ring

    NASA Astrophysics Data System (ADS)

    Meinke, B. K.; Esposito, L. W.; Sremcevic, M.

    2011-10-01

    The Cassini Ultraviolet Imaging Spectrograph has detected 27 statistically significant features in 101 occultations by Saturn's F ring since July 2004. Of those 27 features, 17 likely correspond to transient clumps of material. We calculate from these observations the total number and total mass of transient clumps in the F ring. Constraints from observations place an upper limit on the number and total mass of such clumps. In turn, an upper limit on mass indicates that the clumps are not solid, spherical objects, rather they are loosely-packed, triaxial ellipsoids elongated in azimuth and vertically flattened. The total mass of clumps in the F ring is thus 6.1 x 1014 kg, the equivalent of a 6.8 km icy moon with a density equivalent to that of Prometheus. The differences in optical depth and morphology of the 17 significant features considered here also lead us to believe porosity differences exist among clumps. We investigate how the size distribution of clumps of different porosities evolves and how compaction of such clumps could lead to denser states that resemble moonlets, which describes 2 of the 17 features observed. The results presented here lead to a better model of how transient clumps form, evolve, and survive.

  12. Transient Numerical Modeling of Catalytic Channels

    NASA Technical Reports Server (NTRS)

    Struk, Peter M.; Dietrich, Daniel L.; Miller, Fletcher J.; T'ien, James S.

    2007-01-01

    This paper presents a transient model of catalytic combustion suitable for isolated channels and monolith reactors. The model is a lumped two-phase (gas and solid) model where the gas phase is quasi-steady relative to the transient solid. Axial diffusion is neglected in the gas phase; lateral diffusion, however, is accounted for using transfer coefficients. The solid phase includes axial heat conduction and external heat loss due to convection and radiation. The combustion process utilizes detailed gas and surface reaction models. The gas-phase model becomes a system of stiff ordinary differential equations while the solid phase reduces, after discretization, into a system of stiff ordinary differential-algebraic equations. The time evolution of the system came from alternating integrations of the quasi-steady gas and transient solid. This work outlines the numerical model and presents some sensitivity studies on important parameters including internal transfer coefficients, catalytic surface site density, and external heat-loss (if applicable). The model is compared to two experiments using CO fuel: (1) steady-state conversion through an isothermal platinum (Pt) tube and (2) transient propagation of a catalytic reaction inside a small Pt tube. The model requires internal mass-transfer resistance to match the experiments at lower residence times. Under mass-transport limited conditions, the model reasonably predicted exit conversion using global mass-transfer coefficients. Near light-off, the model results did not match the experiment precisely even after adjustment of mass-transfer coefficients. Agreement improved for the first case after adjusting the surface kinetics such that the net rate of CO adsorption increased compared to O2. The CO / O2 surface mechanism came from a sub-set of reactions in a popular CH4 / O2 mechanism. For the second case, predictions improved for lean conditions with increased external heat loss or adjustment of the kinetics as in the

  13. ALL TRANSIENTS, ALL THE TIME: REAL-TIME RADIO TRANSIENT DETECTION WITH INTERFEROMETRIC CLOSURE QUANTITIES

    SciTech Connect

    Law, Casey J.; Bower, Geoffrey C.

    2012-04-20

    We demonstrate a new technique for detecting radio transients based on interferometric closure quantities. The technique uses the bispectrum, the product of visibilities around a closed loop of baselines of an interferometer. The bispectrum is calibration independent, resistant to interference, and computationally efficient, so it can be built into correlators for real-time transient detection. Our technique could find celestial transients anywhere in the field of view and localize them to arcsecond precision. At the Karl G. Jansky Very Large Array (VLA), such a system would have a high survey speed and a 5{sigma} sensitivity of 38 mJy on 10 ms timescales with 1 GHz of bandwidth. The ability to localize dispersed millisecond pulses to arcsecond precision in large volumes of interferometer data has several unique science applications. Localizing individual pulses from Galactic pulsars will help find X-ray counterparts that define their physical properties, while finding host galaxies of extragalactic transients will measure the electron density of the intergalactic medium with a single dispersed pulse. Exoplanets and active stars have distinct millisecond variability that can be used to identify them and probe their magnetospheres. We use millisecond timescale visibilities from the Allen Telescope Array and VLA to show that the bispectrum can detect dispersed pulses and reject local interference. The computational and data efficiency of the bispectrum will help find transients on a range of timescales with next-generation radio interferometers.

  14. Transient Sub-Poissonian Distribution for Single-Mode Lasers

    NASA Technical Reports Server (NTRS)

    Zang, J. Y.; Gu, Q.; Tian, L. K.

    1996-01-01

    In this paper, the transient photon statistics for single-mode lasers is investigated by making use of the theory of quantum electrodynamics. By taking into account of the transitive time l,we obtain the master equation for Jaynes-Cummings model. The relation between the Mandel factor and the time is obtained by directly solving the master equation. The result shows that a transient phenomenon from the transient super-Poissonian distribution to the transient sub-Poissonian distribution occurs for single-mode lasers. In addition, the influences of the thermal light field and the cavity loss on the transient sub-Poissonian distribution are also studied.

  15. Transient fault behavior in a microprocessor: A case study

    NASA Technical Reports Server (NTRS)

    Duba, Patrick

    1989-01-01

    An experimental analysis is described which studies the susceptibility of a microprocessor based jet engine controller to upsets caused by current and voltage transients. A design automation environment which allows the run time injection of transients and the tracing from their impact device to the pin level is described. The resulting error data are categorized by the charge levels of the injected transients by location and by their potential to cause logic upsets, latched errors, and pin errors. The results show a 3 picoCouloumb threshold, below which the transients have little impact. An Arithmetic and Logic Unit transient is most likely to result in logic upsets and pin errors (i.e., impact the external environment). The transients in the countdown unit are potentially serious since they can result in latched errors, thus causing latent faults. Suggestions to protect the processor against these errors, by incorporating internal error detection and transient suppression techniques, are also made.

  16. Kernschmelze Der nachhaltige Einfluss von Nuklearwaffen auf Politik und Wirtschaft

    NASA Astrophysics Data System (ADS)

    Greiner, Bernd

    "Was sollen wir von einer Kultur halten, der die Ethik stets als wesentliches Element des menschlichen Lebens galt, die aber - außer in fachlicher oder spieltheoretischer Terminologie - nicht in der Lage war, über die Möglichkeit zu sprechen, nahezu alle Menschen zu töten?" Der Fragesteller gehört zu den berühmtesten Physikern des 20. Jahrhunderts und zu den nach wie vor Umstrittensten. über ihn wurde in den 1960er Jahren ein international viel beachtetes Theaterstück geschrieben, vor wenigen Jahren gar eine Oper.

  17. Was leistet ein Sportler? Kraft, Leistung und Energie im Muskel

    NASA Astrophysics Data System (ADS)

    Thaller, Sigrid; Mathelitsch, Leopold

    2006-01-01

    Der Leistungsbegriff ist im Sport weiter gefasst als in der Physik. In beiden Fällen liegt der Fokus jedoch auf einer pro Zeiteinheit erfolgten Energieumsetzung. Allerdings gibt die rein physikalische Leistung nicht immer Auskunft über den Energieumsatz der Muskeln. Die Muskelkraft hängt von der Kontraktionsgeschwindigkeit des Muskels ab. Ein Muskel verhält sich also anders als eine Feder. Für den Hochleistungssport müssen die Energieumsätze der Muskeln durch spezielle Trainings- und Nahrungsprogramme optimiert werden.

  18. Zu einer inhaltsorientierten Theorie des Lernens und Lehrens der biologischen Evolution

    NASA Astrophysics Data System (ADS)

    Wallin, Anita

    Der Zweck dieser Studie (zwecks Überblick siehe dazu Abb. 9.1) war zu untersuchen, wie die Schüler der Sekundarstufe II ein Verständnis von der Theorie der biologischen Evolution entwickeln. Vom Ausgangspunkt "Vorurteile der Schüler“ ausgehend wurden Unterrichtssequenzen entwickelt und drei verschiedene Lernexperimente in einem zyklischen Prozess durchgeführt. Das Wissen der Schüler wurde vor, während und nach den Unterrichtssequenzen mit Hilfe von schriftlichen Tests, Interviews und Diskussionsrunden in kleinen Gruppen abgefragt. Etwa 80 % der Schüler hatten vor dem Unterricht alternative Vorstellungen von Evolution, und in dem Nachfolgetest erreichten circa 75 % ein wissenschaftliches Niveau. Die Argumentation der Schüler in den verschiedenen Tests wurde sorgfältig unter Rücksichtnahme auf Vorurteile, der konzeptionellen Struktur der Theorie der Evolution und den Zielen des Unterrichts analysiert. Daraus konnten Einsichten in solche Anforderungen an Lehren und Lernen gewonnen werden, die Herausforderungen an Schüler und Lehrer darstellen, wenn sie anfangen, evolutionäre Biologie zu lernen oder zu lehren. Ein wichtiges Ergebnis war, dass das Verständnis existierender Variation in einer Population der Schlüssel zum Verständnis von natürlicher Selektion ist. Die Ergebnisse sind in einer inhaltsorientierten Theorie zusammengefasst, welche aus drei verschiedenen Aspekten besteht: 1) den inhaltsspezifischen Aspekten, die einzigartig für jedes wissenschaftliche Feld sind; 2) den Aspekten, die die Natur der Wissenschaft betreffen; und 3) den allgemeinen Aspekten. Diese Theorie kann in neuen Experimenten getestet und weiter entwickelt werden.

  19. Influence of defects on excess charge carrier kinetics studied by transient PC and transient PA

    SciTech Connect

    Feist, H.; Kunst, M.; Swiatkowski, C.

    1997-07-01

    By comparison of transient photoconductivity (TPC) and transient photoinduced absorption (PA) the influence of the density of states in the bandgap on excess charge carrier kinetics is studied for a-Si:H films deposited at different temperatures and for state of the art a-Si:H films in two different states of light soaking. In both series the rising deep defect density leads to an enhancement of electron trapping rather than recombination via deep defects. The samples deposited at temperatures lower than 250 C additionally show a lower effective electron mobility, i.e., a broader conduction band tail.

  20. Charakterisierung von Sulfotransferasen im Gastrointestinaltrakt von Mensch und Ratte und Aktivierung von Promutagenen in V79-Zellen, die eine intestinale Form (1B1) des Menschen und der Ratte exprimieren

    NASA Astrophysics Data System (ADS)

    Teubner, Wera

    2001-05-01

    Die Ausstattung der gastrointestinalen Mukosa des Menschen und der Ratte mit Sulfotransferasen wurde mit Hilfe von Immunodetektion und Enzymaktivitätsmessungen untersucht. In Proben aus Colon und Rektum von 39 Personen wurden die Formen h1A1, h1A3 und h1B1 identifiziert, wobei in einer weiteren Probe, die als einzige von einem an Colitis Ulcerosa erkrankten Patienten stammte, keine Sulfotransferasen nachgewiesen werden konnten. Bei der Immunblot-Analyse war das Expressionsmuster der einzelnen Formen in allen Proben ähnlich. In wenigen Proben waren die relativen Signalintensitäten der h1A1 und der h1B1 um die Hälfte erniedrigt. Der Gehalt von SULT an zytosolischem Protein zeigte einen bis zu 8 - 10fachen Unterschied, er betrug jedoch bei zwei Dritteln der Proben zwischen 0,15 und 0,3 (h1A1 und h1A3) bzw. 0,6 und 0,8 Promille (h1B1). Die Variation konnte nicht auf Alter, Geschlecht oder Krankheitsbild der Patienten zurückgeführt werden. Auch der für die allelischen Varianten der h1A1 beschriebene Effekt auf die Enzymaktiviät bzw. Stabilität konnte in der Menge an immunreaktivem Protein nicht in diesem Ausma detektiert werden. Die Allelhäufigkeit von h1A1*R und h1A1*H war gegenüber der gesunden Bevölkerung nicht verändert. In den sieben Proben aus dem Dünndarm (Coecum, viermal Ileum, Jejunum) konnten zusätzlich die Formen h1E1 und h2A1 identifiziert werden. Ein möglicherweise der Form h1C1 entsprechendes Protein wurde im Magen detektiert. Im Vergleich zum Menschen war die Expression in der Ratte stärker auf die Leber konzentriert. Während beim Menschen in allen untersuchten Abschnitten Sulfotransferasen in Mengen detektiert wurden, die in zwei Fällen (h1B1 und h1A3) sogar den Gehalt in der Leber überstiegen, beschränkte sich die Expression in der Ratte auf im Vergleich zur Leber geringe Mengen im Magen und Dickdarm. Nachgewiesen wurden die r1B1, r1A1 sowie eine nicht identifizierte Form von 35kD, bei der es sich vermutlich um die r1C2 handelt. Im

  1. Modeling seismic swarms triggered by aseismic transients

    NASA Astrophysics Data System (ADS)

    Llenos, Andrea L.; McGuire, Jeffrey J.; Ogata, Yosihiko

    2009-04-01

    The rate of earthquake occurrence varies by many orders of magnitude in a given region due to variations in the stress state of the crust. Our focus here is on variations in seismicity rate triggered by transient aseismic processes such as fluid flow, fault creep or magma intrusion. While these processes have been shown to trigger earthquakes, converting observed seismicity variations into estimates of stress rate variations has been challenging. Essentially aftershock sequences often obscure changes in the background seismicity rate resulting from aseismic processes. Two common approaches for estimating the time dependence of the underlying driving mechanisms are the stochastic Epidemic Type Aftershock Sequence model (ETAS) [Ogata, Y., (1988), Statistical models for earthquake occurrences and residual analysis for point processes, J. Am. Stat. Assoc., 83, 9-27.] and a physical approach based on the rate- and state-model of fault friction [Dieterich, J., (1994), A constitutive law for rate of earthquake production and its application to earthquake clustering, J. Geophys. Res., 99, 2601-2618.]. The models have different strengths that could be combined to allow more quantitative studies of earthquake triggering. To accomplish this, we identify the parameters that relate to one another in the two models and examine their dependence on stressing rate. A particular conflict arises because the rate-state model predicts that aftershock productivity scales with stressing rate while the ETAS model assumes that it is time independent. To resolve this issue, we estimate triggering parameters for 4 earthquake swarms contemporaneous with geodetically observed deformation transients in various tectonic environments. We find that stressing rate transients increase the background seismicity rate without affecting aftershock productivity. We then specify a combined model for seismicity rate variations that will allow future studies to invert seismicity catalogs for variations in

  2. Sleep Modifications in Acute Transient Global Amnesia

    PubMed Central

    Della Marca, Giacomo; Mazza, Marianna; Losurdo, Anna; Testani, Elisa; Broccolini, Aldobrando; Frisullo, Giovanni; Marano, Giuseppe; Morosetti, Roberta; Pilato, Fabio; Profice, Paolo; Vollono, Catello; Di Lazzaro, Vincenzo

    2013-01-01

    Study Objective: Transient global amnesia (TGA) is a temporary memory loss characterized by an abrupt onset of antero-grade and retrograde amnesia, totally reversible. Since sleep plays a major role in memory consolidation, and in the storage of memory-related traces into the brain cortex, the aims of the present study were: (1) to evaluate changes in sleep macro-structure in TGA; (2) to assess modifications in sleep micro-structure in TGA, with particular reference to the arousal EEG and to cyclic alternating pattern (CAP); (3) to compare sleep parameters in TGA patients with a control group of patients with acute ischemic events (“minor stroke” or transient ischemic attack [TIA]) clinically and neuroradiologically “similar” to the TGA. Methods: TGA group: 17 patients, (8 men and 9 women, 60.2 ± 12.5 years). Stroke or TIA (SoT) group: 17 patients hospitalized in the Stroke Unit for recent onset of minor stroke or TIA with hemispheric localization; healthy controls (HC) group: 17 healthy volunteers, matched for age and sex. Patients and controls underwent full-night polysomnography. Results: In the multivariate analysis (conditions TGA, SoT, and HC) a significant effect of the condition was observed for sleep efficiency index, number of awakenings longer 1 min, REM latency, CAP time, and CAP rate. TGA and SoT differed only for CAP time and CAP rate, which were lower in the TGA group. Conclusions: Microstructural modification associated with TGA could be consequent to: (1) hippocampal dysfunction and memory impairment; (2) impairment of arousal-related structures (in particular, cholinergic pathways); (3) emotional distress. Citation: Della Marca G; Mazza M; Losurdo A; Testani E; Broccolini A; Frisullo G; Marano G; Morosetti R; Pilato F; Profice P; Vollono C; Di Lazzaro V. Sleep modifications in acute transient global amnesia. J Clin Sleep Med 2013;9(9):921-927. PMID:23997704

  3. Detection of Transient Signals from Extraterrestrial Technologies

    NASA Astrophysics Data System (ADS)

    Tarter, J. C.

    2003-05-01

    If you were an engineer and wanted to build a beacon with which to attract the attention of any emerging technological civilizations in the Milky Way galaxy, how would you do it? SETI 2020: A Roadmap for the Search for Extraterrestrial Intelligence (a recent report of the SETI Science and Technology Working Group) describes a number of different beacon scenarios, as well as examples of leakage radiation, all of which would lead to signal types that appear as transients in the sky of any given receiving civilization. Most SETI searches to date have been ill-matched to the problem of finding transient signals; the dwell time on source has been short, and the same directions have not been revisited very often. Both the Omnidirectional SETI System (OSS) proposed in SETI 2020, and the Allen Telescope Array (ATA) will offer greatly improved opportunities for detecting radio transients, whether they are from technological or astrophysical sources. The ATA should be operational within a few years, but the OSS will not be affordable until Moore's Law has significantly reduced the cost for the compute power needed to form all beams on the sky and all frequency channels in the spectrometers. This is estimated to be { ˜ 1016}-10{21} ops depending on the total collecting area of the array. Nevertheless, the opportunity to build a radio-fly's-eye or radio camera (suggested by Robert Dixon in 1988) is now getting close enough to warrant prototyping and construction of small size arrays and receivers; several programs are underway.

  4. Simulated transient behavior of HT9 cladding

    SciTech Connect

    Cannon, N.S.; Huang, F.H.; Hamilton, M.L.

    1988-09-01

    Simulated transient tests were performed on sections of HT9 fast- reactor fuel pin cladding irradiated to a fast fluence of nearly 16 /times/ 10/sup 22/ n/cm/sup 2/ at temperatures ranging from 370 to 620/degree/C. After removing fuel, these specimens were internally pressurized and heated at one of several constant rates (0.56, 5.6, or 110/degree/C/s) until specimen failure occurred. A slight reduction of strength was observed in irradiated cladding, particularly at 110/degree/C/s, when compared with transient results from unirradiated HT9 control specimens; however, this strength reduction did not correlate with either fluence or irradiation temperature. A small reduction of ductility was also observed for irradiated cladding failing at temperatures above 800/degree/C at the lower heating rates (0.56 or 5.6/degree/C/s); irradiated cladding was generally more ductile at 110/degree/C/s than unirradiated HT9 cladding. The HT9 cladding results were compared with similar transient data obtained previously from 20% Cold-Worked Type 316 Stainless Steel (316 SS) cladding. In the unirradiated state, this austenitic cladding is stronger and less ductile than HT9 cladding. However, the 316 SS cladding undergoes a significant loss of strength and ductility during irradiation when in contact with oxide fuel, by a mechanism labeled the fuel adjacency effect (FAE). The FAE is believed to be liquid metal embrittlement from fission products. The HT9 fuel pin cladding remained as strong or stronger than the 316 SS cladding when irradiated in contact with fuel, showing no evidence of the FAE up to the high fluences reported here. The ductility of the irradiated HT9 fuel pin cladding remained significantly greater than that of irradiated 316 SS cladding. 14 refs., 11 figs., 1 tab.

  5. Transient Pressure Test Article Test Program

    NASA Technical Reports Server (NTRS)

    Vibbart, Charles M.

    1989-01-01

    The Transient Pressure Test Article (TPTA) test program is being conducted at a new test facility located in the East Test Area at the National Aeronautics and Space Administration's (NASA's) Marshall Space Flight Center (MSFC) in Huntsville, Alabama. This facility, along with the special test equipment (STE) required for facility support, was constructed specifically to test and verify the sealing capability of the Redesigned Solid Rocket Motor (RSRM) field, igniter, and nozzle joints. The test article consists of full scale RSRM hardware loaded with inert propellant and assembled in a short stack configuration. The TPTA is pressurized by igniting a propellant cartridge capable of inducing a pressure rise rate which stimulates the ignition transient that occurs during launch. Dynamic loads are applied during the pressure cycle to simulate external tank attach (ETA) strut loads present on the ETA ring. Sealing ability of the redesigned joints is evaluated under joint movement conditions produced by these combined loads since joint sealing ability depends on seal resilience velocity being greater than gap opening velocity. Also, maximum flight dynamic loads are applied to the test article which is either pressurized to 600 psia using gaseous nitrogen (GN2) or applied to the test article as the pressure decays inside the test article on the down cycle after the ignition transient cycle. This new test facility is examined with respect to its capabilities. In addition, both the topic of test effectiveness versus space vehicle flight performance and new aerospace test techniques, as well as a comparison between the old SRM design and the RSRM are presented.

  6. Blade loss transient dynamic analysis of turbomachinery

    NASA Technical Reports Server (NTRS)

    Stallone, M. J.; Gallardo, V.; Storace, A. F.; Bach, L. J.; Black, G.; Gaffney, E. F.

    1982-01-01

    This paper reports on work completed to develop an analytical method for predicting the transient non-linear response of a complete aircraft engine system due to the loss of a fan blade, and to validate the analysis by comparing the results against actual blade loss test data. The solution, which is based on the component element method, accounts for rotor-to-casing rubs, high damping and rapid deceleration rates associated with the blade loss event. A comparison of test results and predicted response show good agreement except for an initial overshoot spike not observed in test. The method is effective for analysis of large systems.

  7. Slow-blue PanSTARRS transients

    NASA Astrophysics Data System (ADS)

    MacLeod, Chelsea L.; Bruce, Alastair; Lawrence, Andy; Ward, Martin; Collinson, James; Elvis, Martin; Gezari, Suvi; Smartt, Steven; Smith, Ken; Wright, Darryl; Fraser, Morgan

    2015-01-01

    Photometric and spectroscopic monitoring of 50 blue, nuclear "transients" in PanSTARRS-1 has revealed different types of extremely variable AGN. The majority show a gradual brightening by ~2 mag from the SDSS observation a decade ago and may represent a new class of AGN microlensed by foreground galaxies. Spectra from the William Herschel Telescope identify these as z~1 AGN with atypical spectroscopic properties. We present an analysis of their photometric and spectroscopic variability in an effort to constrain the detailed structure of the source AGN.

  8. Optical "anti-transient" detected by MASTER

    NASA Astrophysics Data System (ADS)

    Denisenko, D.; Gorbovskoy, E.; Lipunov, V.; Balanutsa, P.; Yecheistov, V.; Tiurina, N.; Kornilov, V.; Belinski, A.; Shatskiy, N.; Chazov, V.; Kuznetsov, A.; Zimnukhov, D.; Krushinsky, V.; Zalozhnih, I.; Popov, A.; Bourdanov, A.; Punanova, A.; Ivanov, K.; Yazev, S.; Budnev, N.; Konstantinov, E.; Chuvalaev, O.; Poleshchuk, V.; Gress, O.; Parkhomenko, A.; Tlatov, A.; Dormidontov, D.; Senik, V.; Yurkov, V.; Sergienko, Y.; Varda, D.; Sinyakov, E.; Shurpakov, S.; Shumkov, V.; Podvorotny, P.; Levato, H.; Saffe, C.; Mallamaci, C.; Lopez, C.; Podest, F.

    2013-02-01

    We have started the search for the disappearing stars (optical "anti-transients", OATs) in the MASTER database. The first result is the detection of a deep (~3.5 magnitudes) fading of the bright star TYC 2505-672-1 whose variability was previously unknown. This star has the coordinates 09 53 10.00 +33 53 52.7 and magnitudes V=10.71, B=12.51 in Tycho2 catalogue and J=7.61, H=6.78, K=6.57 in 2MASS.

  9. Three Decades of Explosive High Energy Transients

    NASA Technical Reports Server (NTRS)

    Kouveliotou, Chryssa

    2013-01-01

    Gamma-Ray Bursts are the most brilliant explosions in space. The first GRB was discovered on 1967, just 40 years ago. It took several years and multiple generations of space and ground instruments to unravel some of the mysteries of this phenomenon. However, many questions remain open today. I will discuss the history, evolution and current status of the GRB field and its contributions in our understanding of the transient high energy sky. Finally, I will describe how GRBs can be utilized in future missions as tools, to probe the cosmic chemical evolution of the Universe and the star formation rates.

  10. Cardiogenic embolism producing crescendo transient ischemic attacks.

    PubMed

    Geraghty, Patrick J; Oak, Jack; Choi, Eric T

    2005-09-01

    Lateralizing, repetitive transient ischemic attacks are characteristic of symptomatic carotid bifurcation atherosclerotic plaques. We report a case in which a cardiogenic embolus, after lodging at the left carotid bifurcation, produced crescendo episodes of expressive aphasia and mild right upper extremity weakness. Complete neurological recovery was achieved following emergent carotid embolectomy and endarterectomy. This case demonstrates that the laminar nature of internal carotid blood flow may result in the localization of embolic events to a single region of the cerebral vasculature, regardless of the source lesion in the carotid artery. The role of endoluminal techniques in the diagnosis and management of such lesions is discussed.

  11. Transient upset models in computer systems

    NASA Technical Reports Server (NTRS)

    Mason, G. M.

    1983-01-01

    Essential factors for the design of transient upset monitors for computers are discussed. The upset is a system level event that is software dependent. It can occur in the program flow, the opcode set, the opcode address domain, the read address domain, and the write address domain. Most upsets are in the program flow. It is shown that simple, external monitors functioning transparently relative to the system operations can be built if a detailed accounting is made of the characteristics of the faults that can happen. Sample applications are provided for different states of the Z-80 and 8085 based system.

  12. Transient auditory hallucinations in an adolescent.

    PubMed

    Skokauskas, Norbert; Pillay, Devina; Moran, Tom; Kahn, David A

    2010-05-01

    In adolescents, hallucinations can be a transient illness or can be associated with non-psychotic psychopathology, psychosocial adversity, or a physical illness. We present the case of a 15-year-old secondary-school student who presented with a 1-month history of first onset auditory hallucinations, which had been increasing in frequency and severity, and mild paranoid ideation. Over a 10-week period, there was a gradual diminution, followed by a complete resolution, of symptoms. We discuss issues regarding the diagnosis and prognosis of auditory hallucinations in adolescents.

  13. Transient infantile hyperthyrotropinaemia. Report of a case.

    PubMed Central

    Miyai, K; Amino, N; Nishi, K; Fujie, T; Nakatani, K; Nose, O; Harada, T; Yabuuchi, H; Doi, K; Yamamoto, T; Satake, R; Tsuruhara, T; Oura, T

    1979-01-01

    A case of transient hyperthyrotropinaemia was found by mass screening for neonatal hypothyroidism using the paired TSH assay method. The patient was a baby boy born at term after a normal pregnancy who grew without any abnormal signs or symptoms. For the first 7 months after birth, his serum TSH was abnormally high while his total serum T4, T3, and free T4, T3 were within normal limits, exept for slightly low free T4 level at 7 months. The raised serum TSH decreased spontaneously to within normal limits after he was 9 months old. PMID:533303

  14. Transient thermal response of ablating bodies

    NASA Technical Reports Server (NTRS)

    Arai, N.; Karashima, K.-I.

    1979-01-01

    A numerical study of transient thermal response of a blunt-nosed axisymmetric body made of Teflon is presented using a two-layer thermal model. It is shown that phase change and transverse heat conduction have a considerable effect on the internal temperature field. Comparison of the numerical results with experimental data shows that the single-layer thermal model does not predict the real feature of the thermal field, whereas the results of the two-layer thermal model agree reasonably well with the experiment.

  15. Modeling of transient heat pipe operation

    NASA Technical Reports Server (NTRS)

    Colwell, G. T.; Hartley, J. G.

    1985-01-01

    The overall goal is to gain a better understanding of the transient behavior of heat pipes operating under both normal and adverse conditions. Normal operation refers to cases where the capillary structure remains fully wetted. Adverse operation occurs when drying, re-wetting, choking, noncontinuum flow, freezing, thawing etc., occur within the heat pipe. The work was redirected towards developing the capability to predict operational behavior of liquid metal heat pipes used for cooling aerodynamic structures. Of particular interest is the startup of such heat pipes from an initially frozen state such as might occur during re-entry of a space vehicle into the Earth's atmosphere or during flight of hypersonic aircraft.

  16. Asiago spectroscopic observation of four transients

    NASA Astrophysics Data System (ADS)

    Ochner, P.; Benetti, S.; Cappellaro, E.; Elias-Rosa, N.; Pastorello, A.; Tartaglia, L.; Terreran, G.; Tomasella, L.; Turatto, M.

    2015-08-01

    The Asiago Transient Classification Program (Tomasella et al. 2014, AN, 335, 841) reports the spectroscopic classification of PSN J23164332+3359476 in UGC 12474, discovered by C. Emmanouilidi; PS15bom in SDSS J232637.06-001723.0, discovered by the PS1 Science Consortium (Atel #7864); PSN J02484234+1418454 in UGC 2282, discovered by S. Leonini, M. Conti, P. Rosi, L.M. Tinjaca Ramirez and G. Guerrini of the Italian Supernovae Search Project (ISSP); and ASASSN-15mr, discovered by the All Sky Automated Survey for SuperNovae (ASAS-SN; ATel #7811).

  17. Transient acceleration in f(T) gravity

    NASA Astrophysics Data System (ADS)

    Qi, Jing-Zhao; Yang, Rong-Jia; Zhang, Ming-Jian; Liu, Wen-Biao

    2016-02-01

    Recently an f(T) gravity based on the modification of teleparallel gravity was proposed to explain the accelerated expansion of the universe. We use observational data from type Ia supernovae, baryon acoustic oscillations, and cosmic microwave background to constrain this f(T) theory and reconstruct the effective equation of state and the deceleration parameter. We obtain the best-fit values of parameters and find an interesting result that the constrained f(T) theory allows for the accelerated Hubble expansion to be a transient effect.

  18. Transient absorption spectroscopy of laser shocked explosives

    SciTech Connect

    Mcgrane, Shawn D; Dang, Nhan C; Whitley, Von H; Bolome, Cindy A; Moore, D S

    2010-01-01

    Transient absorption spectra from 390-890 nm of laser shocked RDX, PETN, sapphire, and polyvinylnitrate (PVN) at sub-nanosecond time scales are reported. RDX shows a nearly linear increase in absorption with time after shock at {approx}23 GPa. PETN is similar, but with smaller total absorption. A broad visible absorption in sapphire begins nearly immediately upon shock loading but does not build over time. PVN exhibits thin film interference in the absorption spectra along with increased absorption with time. The absorptions in RDX and PETN are suggested to originate in chemical reactions happening on picosecond time scales at these shock stresses, although further diagnostics are required to prove this interpretation.

  19. Transient Heat Transfer in TCAP Coils

    SciTech Connect

    Steimke, J.L.

    1999-03-09

    The Thermal Cycling Absorption Process (TCAP) is used to separate isotopes of hydrogen. TCAP involves passing a stream of mixed hydrogen isotopes through palladium deposited on kieselguhr (Pd/k) while cycling the temperature of the Pd/k. Kieselguhr is a silica mineral also called diatomite. To aid in the design of a full scale facility, the Thermal Fluids Laboratory was used by the Chemical and Hydrogen Technology Section to compare the heat transfer properties of three different configurations of stainless steel coils containing kieselguhr and helium. Testing of coils containing Pd/k and hydrogen isotopes would have been more prototypical but would have been too expensive. Three stainless steel coils filled with kieselguhr were tested; one made from 2.0 inch diameter tubing, one made from 2.0 inch diameter tubing with foam copper embedded in the kieselguhr and one made from 1.25 inch diameter tubing. It was known prior to testing that increasing the tubing diameter from 1.25 inch to 2.0 inch would slow the rate of temperature change. The primary purpose of the testing was to measure to what extent the presence of copper foam in a 2.0" tubing coil would compensate for the effect of larger diameter. Each coil was connected to a pressure gage and the coil was evacuated and backfilled with helium gas. Helium was used instead of a mixture of hydrogen isotopes for reasons of safety. Each coil was quickly immersed in a stirred bath of ethylene glycol at a temperature of approximately 100 degrees Celsius. The coil pressure increased, reflecting the increase in average temperature of its contents. The pressure transient was recored as a function of time after immersion. Because of the actual process will use Pd/k instead of kieselguhr, additional tests were run to determine the differences in thermal properties between the two materials. The method was to position a thermocouple at the center of a hollow sphere and pack the sphere with Pd/k. The sphere was sealed, quickly

  20. Transient Heat Transfer in TCAP Coils

    SciTech Connect

    Steimke, J.L.

    1999-03-09

    The Thermal Cycling Absorption Process (TCAP) is used to separate isotopes of hydrogen. TCAP involves passing a stream of mixed hydrogen isotopes through palladium deposited on kieselguhr (Pd/k) while cycling the temperature of the Pd/k. Kieselguhr is a silica mineral also called diatomite. To aid in the design of a full scale facility, the Thermal Fluids Laboratory was used by the Chemical and Hydrogen Technology Section to compare the heat transfer properties of three different configurations of stainless steel coils containing kieselguhr and helium. Testing of coils containing Pd/k and hydrogen isotopes would have been more prototypical but would have been too expensive. Three stainless steel coils filled with kieselguhr were tested; one made from 2.0 inch diameter tubing, one made from 2.0 inch diameter tubing with foam copper embedded in the kieselguhr and one made from 1.25 inch diameter tubing. It was known prior to testing that increasing the tubing diameter from 1.25 inch to 2.0 inch would slow the rate of temperature change. The primary purpose of the testing was to measure to what extent the presence of copper foam in a 2.0 tubing coil would compensate for the effect of larger diameter. Each coil was connected to a pressure gage and the coil was evacuated and backfilled with helium gas. Helium was used instead of a mixture of hydrogen isotopes for reasons of safety. Each coil was quickly immersed in a stirred bath of ethylene glycol at a temperature of approximately 100 degrees Celsius. The coil pressure increased, reflecting the increase in average temperature of its contents. The pressure transient was recored as a function of time after immersion. Because of the actual process will use Pd/k instead of kieselguhr, additional tests were run to determine the differences in thermal properties between the two materials. The method was to position a thermocouple at the center of a hollow sphere and pack the sphere with Pd/k. The sphere was sealed, quickly

  1. Transient Mixed Convection Validation for NGNP

    SciTech Connect

    Smith, Barton; Schultz, Richard

    2015-10-19

    The results of this project are best described by the papers and dissertations that resulted from the work. They are included in their entirety in this document. They are: (1) Jeff Harris PhD dissertation (focused mainly on forced convection); (2) Blake Lance PhD dissertation (focused mainly on mixed and transient convection). This dissertation is in multi-paper format and includes the article currently submitted and one to be submitted shortly; and, (3) JFE paper on CFD Validation Benchmark for Forced Convection.

  2. Transient surface tension in miscible liquids.

    PubMed

    Lacaze, Laurent; Guenoun, Patrick; Beysens, Daniel; Delsanti, Michel; Petitjeans, Philippe; Kurowski, Pascal

    2010-10-01

    Evidence of the existence of a transient surface tension between two miscible fluid phases is given. This is done by making use of a density matched free of gravity perturbations, binary liquid of isobutyric acid and water, which presents a miscibility gap and is studied by light scattering. The experiment is performed very near the critical point of the binary liquid, where the diffusion of phases is extremely slow. The surface tension is deduced from the evolution of the structure factor obtained from low angle light scattering. The latter evolution is successfully analyzed in terms of a local equilibrium diffusive approach that makes explicit how the surface tension decreases with time. PMID:21230286

  3. THE HIGH ENERGY TRANSIENT EXPLORER TRIGGERING ALGORITHM

    SciTech Connect

    E. FENIMORE; M. GALASSI

    2001-05-01

    The High Energy Transient Explorer uses a triggering algorithm for gamma-ray bursts that can achieve near the statistical limit by fitting to several background regions to remove trends. Dozens of trigger criteria run simultaneously covering time scales from 80 msec to 10.5 sec or longer. Each criteria is controlled by about 25 constants which gives the flexibility to search wide parameter spaces. On orbit, we have been able to operate at 6{sigma}, a factor of two more sensitive than previous experiments.

  4. Transient magmatic convection prolonged by solidification

    NASA Technical Reports Server (NTRS)

    Brandeis, Genevieve; Marsh, Bruce D.

    1990-01-01

    Fluid dynamic experiments have been conducted on the solidification of a paraffin layer, in order to elucidate the transient stage of convection created in cooling magma by the fact that strong changes in viscosity with crystallization lock up within an inwardly propagating crust much buoyancy that would otherwise be available to drive convection. The interior of the magma remains isothermal, and the temperature decreases uniformly until it is locked at the convective liquidus; the crystals are fine hairlike dendrites without major compositional differentiations. Measurements over time are presented of crust thickness, convective velocity, and heat transfer.

  5. Future Transient Testing of Advanced Fuels

    SciTech Connect

    Jon Carmack

    2009-09-01

    The transient in-reactor fuels testing workshop was held on May 4–5, 2009 at Idaho National Laboratory. The purpose of this meeting was to provide a forum where technical experts in transient testing of nuclear fuels could meet directly with technical instrumentation experts and nuclear fuel modeling and simulation experts to discuss needed advancements in transient testing to support a basic understanding of nuclear fuel behavior under off-normal conditions. The workshop was attended by representatives from Commissariat à l'Énergie Atomique CEA, Japanese Atomic Energy Agency (JAEA), Department of Energy (DOE), AREVA, General Electric – Global Nuclear Fuels (GE-GNF), Westinghouse, Electric Power Research Institute (EPRI), universities, and several DOE national laboratories. Transient testing of fuels and materials generates information required for advanced fuels in future nuclear power plants. Future nuclear power plants will rely heavily on advanced computer modeling and simulation that describes fuel behavior under off-normal conditions. TREAT is an ideal facility for this testing because of its flexibility, proven operation and material condition. The opportunity exists to develop advanced instrumentation and data collection that can support modeling and simulation needs much better than was possible in the past. In order to take advantage of these opportunities, test programs must be carefully designed to yield basic information to support modeling before conducting integral performance tests. An early start of TREAT and operation at low power would provide significant dividends in training, development of instrumentation, and checkout of reactor systems. Early start of TREAT (2015) is needed to support the requirements of potential users of TREAT and include the testing of full length fuel irradiated in the FFTF reactor. The capabilities provided by TREAT are needed for the development of nuclear power and the following benefits will be realized by the

  6. Transient simulation of ram accelerator flowfields

    NASA Astrophysics Data System (ADS)

    Drabczuk, Randall P.; Rolader, G.; Dash, S.; Sinha, N.; York, B.

    1993-01-01

    This paper describes the development of an advanced computational fluid dynamic (CFD) simulation capability in support of the USAF Armament Directorate ram accelerator research initiative. The state-of-the-art CRAFT computer code has been specialized for high fidelity, transient ram accelerator simulations via inclusion of generalized dynamic gridding, solution adaptive grid clustering, and high pressure thermo-chemistry. Selected ram accelerator simulations are presented that serve to exhibit the CRAFT code capabilities and identify some of the principle research/design Issues.

  7. Transient simulation of ram accelerator flowfields

    NASA Astrophysics Data System (ADS)

    Sinha, N.; York, B. J.; Dash, S. M.; Drabczuk, R.; Rolader, G. E.

    1992-10-01

    This paper describes the development of an advanced computational fluid dynamic (CFD) simulation capability in support of the U.S. Air Force Armament Directorate's ram accelerator research initiative. The state-of-the-art CRAFT computer code has been specialized for high fidelity, transient ram accelerator simulations via inclusion of generalized dynamic gridding, solution adaptive grid clustering, high pressure thermochemistry, etc. Selected ram accelerator simulations are presented which serve to exhibit the CRAFT code's capabilities and identify some of the principal research/design issues.

  8. Transient vibration of thin viscoelastic orthotropic plates

    NASA Astrophysics Data System (ADS)

    Soukup, J.; Valeš, F.; Volek, J.; Skočilas, J.

    2011-02-01

    This article deals with solutions of transient vibration of a rectangular viscoelastic orthotropic thin 2D plate for particular deformation models according to Flügge and Timoshenko-Mindlin. The linear model, a general standard viscoelastic body, of the rheologic properties of a viscoelastic material was applied. The time and coordinate curves of the basic quantities displacement, rotation, velocity, stress and deformation are compared. The results obtained by an approximate analytic method are compared with numerical results for 3D plate generated by FEM application and with experimental investigation.

  9. Sustained Perceptual Deficits from Transient Sensory Deprivation

    PubMed Central

    Sanes, Dan H.

    2015-01-01

    Sensory pathways display heightened plasticity during development, yet the perceptual consequences of early experience are generally assessed in adulthood. This approach does not allow one to identify transient perceptual changes that may be linked to the central plasticity observed in juvenile animals. Here, we determined whether a brief period of bilateral auditory deprivation affects sound perception in developing and adult gerbils. Animals were reared with bilateral earplugs, either from postnatal day 11 (P11) to postnatal day 23 (P23) (a manipulation previously found to disrupt gerbil cortical properties), or from P23-P35. Fifteen days after earplug removal and restoration of normal thresholds, animals were tested on their ability to detect the presence of amplitude modulation (AM), a temporal cue that supports vocal communication. Animals reared with earplugs from P11-P23 displayed elevated AM detection thresholds, compared with age-matched controls. In contrast, an identical period of earplug rearing at a later age (P23-P35) did not impair auditory perception. Although the AM thresholds of earplug-reared juveniles improved during a week of repeated testing, a subset of juveniles continued to display a perceptual deficit. Furthermore, although the perceptual deficits induced by transient earplug rearing had resolved for most animals by adulthood, a subset of adults displayed impaired performance. Control experiments indicated that earplugging did not disrupt the integrity of the auditory periphery. Together, our results suggest that P11-P23 encompasses a critical period during which sensory deprivation disrupts central mechanisms that support auditory perceptual skills. SIGNIFICANCE STATEMENT Sensory systems are particularly malleable during development. This heightened degree of plasticity is beneficial because it enables the acquisition of complex skills, such as music or language. However, this plasticity comes with a cost: nervous system development

  10. Der Kalte Krieg in der Peripherie Griechische Physiker und Atomenergie nach dem Zweiten Weltkrieg

    NASA Astrophysics Data System (ADS)

    Vlahakis, George N.

    Die vorliegende Arbeit analysiert Ansichten griechischer Physiker zur Atomenergie und deren mögliche Anwendung nach dem Zweiten Weltkrieg, insbesondere während des Kalten Kriegs. Einerseits werden Ansichten von Physik- Professoren griechischer Universitäten präsentiert - beispielsweise von Dimitrios Hondros, der Student von Arnold Sommerfeld und Mitarbeiter von Peter Debye in München war, und andererseits wird die Politik der griechischen Regierung für die Etablierung eines Forschungsinstitutes diskutiert, das der Entwicklung der Atomenergie dienen sollte; ebenfalls wird eine öffentliche Meinungsumfrage zu diesen Thema, die in den Tageszeitungen der damaligen Zeit präsentiert wurde, diskutiert.

  11. Chaos für die Schule!: Nichtlinearität und Strukturbildung

    NASA Astrophysics Data System (ADS)

    Nordmeier, Volkhard; Schlichting, Hans Joachim

    2003-01-01

    Modellsysteme können Schülern die Grundlagen der nichtlinearen Physik anschaulich vermitteln. Sie schlagen so einen Bogen von der Schulphysik zur aktuellen Forschung. Ein solches Modellsystem ist das chaotische Wasserrad, das Lehrer auf einfache Weise für den Schulunterricht nachbauen können. Im Wesentlichen steuert der Zufluss des Wassers das Verhalten des Wasserrads. Wächst er, so durchläuft das Rad von der geordneten, gleichförmigen Drehung bis zum Chaos verschiedene Phasen von Bewegungsfiguren. Das Experiment kann grundlegende Modelle und Begriffe der Chaostheorie demonstrieren: lokale und globale Bifurkationen und verschiedene Übergänge ins Chaos.

  12. Das Prinzip Bewegung - Herz und Gehirn als Metaphern des menschlichen Lebens

    NASA Astrophysics Data System (ADS)

    Otis, Laura

    In diesem Jahr, in dem wir Charles Darwins gedenken, möchte ich etwas riskieren und eine Frage erörtern, die für die Literatur ebenso wie für die Biologie zentral ist: Was ist das Leben? Die Antwort auf diese Frage finden wir nicht in der Bibliothek und nicht im Labor, zumindest nicht an diesen erkenntnisproduzierenden Stellen allein. Als Literaturwissenschaftlerin und ehemalige Naturwissenschaftlerin glaube ich, dass wir das Leben nur verstehen werden, wenn wir seinen Wirkungen überall nachforschen, inklusive in der Literatur.

  13. Von Donuts und Zucker: Mit Neutronen biologische Makromoleküle erforschen

    NASA Astrophysics Data System (ADS)

    May, Roland P.

    2003-05-01

    Für die Erforschung von Biomolekülen bieten Neutronen einzigartige Eigenschaften. Vor allem ihre unterschiedliche Wechselwirkung mit dem natürlichen Wasserstoff und seinem schweren Isotop Deuterium ermöglicht tiefe Einblicke in Struktur, Funktion und Dynamik von Proteinen, Nukleinsäuren und Biomembranen. Bei vielen Fragestellungen zur Strukturaufklärung gibt es kaum oder keine Alternative zum Neutron. Das Institut Laue-Langevin trägt Bahnbrechendes zum Erfolg der Neutronen-Methoden in der Biologie bei.

  14. Suchmaschinen und Informationsqualität: Status quo, Problemfelder, Entwicklungstendenzen

    NASA Astrophysics Data System (ADS)

    Maaß, Christian; Gräfe, Gernot

    Das Thema Informationsqualität wird in den vorangegangenen Beiträgen umfangreich betrachtet. Die dabei geführte Diskussion zielt vordergründig auf organisatorische Dimensionen der Datenqualität, die strukturierte Datenanalyse oder Datenmanagementprozesse im Unternehmen ab. Dabei liegt ein Großteil der zur Unterstützung von Entscheidungsprozessen herangezogenen Informationen in Datenbanksystemen bzw. in einem Data Warehouse vor. Auf Basis verschiedener Analysetools (z. B. Online-Analytical-Processing) lassen sich diese Informationen dann systematisch auswerten. Allerdings können Entscheidungen nicht allein aufgrund der unternehmensintern vorliegenden Informationen getroffen werden. Vielmehr gilt es auch die aus der Unternehmensumwelt relevanten Informationen zu verarbeiten, die zum Teil über das Internet zugänglich sind. Im Gegensatz zu unternehmensinternen Datenbanksystemen handelt es sich beim Internet um ein schwach strukturiertes und offenes Netzwerk, weshalb die im Unternehmenskontext eingesetzten Analysetools kaum weiterhelfen, um Informationen mit hoher Qualität herauszufiltern. In dieser Situation spielen Suchmaschinen eine wichtige Rolle, um Informationen zu identifizieren und anhand verschiedener Kriterien in Form einer Suchergebnisseite zu sortieren.

  15. Organization of the und R chromosome region in maize

    SciTech Connect

    Kermicle, J.

    1989-07-01

    Maize is highly polymorphic in pattern of anthocyanin pigmentation. That portion of the total variation which is attributable to one gene is revealed when alleles from various sources are incorporated into a standard line by backcrossing before comparison under uniform environments. The variation associated with such collections of {und R} alleles is discontinuous, suggesting the presence of discrete units of function. Alleles comprising more than one such element constitute an allelic complex or gene family. An objective of the early years of investigation under this grant was to work out the arrangement of genic elements in such allelic complexes. Elements in a complex are identified by independent mutation and separability by recombination, the latter serving also to order them in the chromosome. Alleles having from one to three elements each were represented among five accessions of the colored-seed, colored-plant class ({und R-r}). Nine different genic elements were identified. This line of inquiry has been de-emphasized in recent years in deference to investigating the organization of individual genic elements. We have focused on a set of readily distinguished elements that were identified or produced in the analysis of allelic complexes. 7 refs., 1 tab.

  16. Temperature-Centric Evaluation of Sensor Transients

    NASA Astrophysics Data System (ADS)

    Ayhan, Tuba; Muezzinoglu, Kerem; Vergara, Alexander; Yalcin, Mustak

    2011-09-01

    Controllable sensing conditions provide the means for diversifying sensor response and achieving better selectivity. Modulating the sensing layer temperature of metal-oxide sensors is a popular method for multiplexing the limited number of sensing elements that can be employed in a practical array. Time limitations in many applications, however, cannot tolerate an ad-hoc, one-size-fits-all modulation pattern. When the response pattern is itself non-stationary, as in the transient phase, a temperature program also becomes infeasible. We consider the problem of determining and tuning into a fixed optimum temperature in a sensor array. For this purpose, we present an empirical analysis of the temperature's role on the performance of a metal-oxide gas sensor array in the identification of odorants along the response transient. We show that the optimal temperature in this sense depends heavily on the selection of (i) the set of candidate analytes, (ii) the time-window of the analysis, (iii) the feature extracted from the sensor response, and (iv) the computational identification method used.

  17. Solarwind Transient flows and Associated Forbush Decrease

    NASA Astrophysics Data System (ADS)

    Kaushik, S. C.; Subhash Chandra Kaushik

    2011-12-01

    In this study we discuss the behavior of cosmic rays during the phase of highly intense or ultra intense geomagnetic storms, as shocks driven by energetic coronal mass ejections (CME's) and other interplanetary (IP) transients are mainly responsible for initiating large and intense geomagnetic storms. Observational results indicate that galactic cosmic rays (CR) coming from deep surface interact with these abnormal solar and IP conditions and suffer modulation effects. In this paper a systematic study has been performed to analyze the CRI variation during super storms i.e. very intense geomagnetic storms with Dst index ≥ -100 nT. The neutron monitor data of three stations Oulu (Rc = 0.77 GV), Climax (Rc = 2.97 GV) and Huancayo (Rc = 13.01 GV) well distributed over different latitudes and hourly values of IMF parameters derived from satellite observations near Earth IP medium from OMNI Data base is used for the period spanning over solar cycles 20, 21, 22 and 23. It is found that AP and AE indices show rise before the forward turnings of IMF, while the Dst index shows a classic storm time decrease. The analysis indicates that the magnitude of all the responses depends on BZ component of IMF being well correlated with solar maximum and minimum periods. Transient decrease in CRI with slow recovery is observed during the storm phase duration.

  18. Transient ponderomotive effects in superconducting cavities

    SciTech Connect

    Kirk Davis; Thomas Powers

    2005-07-10

    A number of experiments were performed on an installed and operational 5-cell CEBAF cavity to determine the minimum time required to re-establish stable gradient after a cavity window arc trip. Once it was determined that gradient could be re-established within 10 ms by applying constant power RF signal in a voltage controlled Oscillator-phase locked loop based system (VCO-PLL), a second experiment was performed to determine if stable gradient could be re-established using a fixed frequency RF system with a simple gradient based closed loop control system. During this test, fluctuations were observed in the cavity forward power signal, the source of which was later determined to be pondero-motive in nature. These ponderomotive induced vibrations were quantified using a cavity resonance monitor and a VCO-PLL RF system. Experimental results, analysis of the resultant klystron power transients, the decay time of the transients, and the implications with respect to fast reset algorithms will be presented.

  19. Transient Thermoelectric Generator: An Active Load Story

    NASA Astrophysics Data System (ADS)

    Stockholm, J. G.; Goupil, C.; Maussion, P.; Ouerdane, H.

    2015-06-01

    Under stationary conditions, the optimization of maximum power output and efficiency of thermoelectric generators (TEG) is a well-known subject. Use of a finite-time thermodynamics (FTT) approach to the description of TEGs has demonstrated that there exists a closed feedback effect between the output electrical load value and the entering heat current. From the practical point of view, this effect is strongly evidenced by the use of direct current (DC-to-DC) converters as active loads. Both transient conditions and FTT contribute to a complex landscape of the optimization of the power and efficiencies of a TEG. It has been claimed that the use of inductive load may lead to a strong enhancement of the efficiency, and the frequency response of a TEG as a band-pass filter has also been recently reported. We consider these results using a classical linear Onsager approach of a TEG operating under transient conditions. We show that a trans-admittance may be defined as a coupling element between the input and the output, leading to the observed electric-to-thermal feedback. We discuss recent experiments on a TEG connected to an active load, which is reported to boast an efficiency exceeding the usual stationary DC thermoelectric efficiency.

  20. Detecting Thermal Cloaks via Transient Effects.

    PubMed

    Sklan, Sophia R; Bai, Xue; Li, Baowen; Zhang, Xiang

    2016-09-08

    Recent research on the development of a thermal cloak has concentrated on engineering an inhomogeneous thermal conductivity and an approximate, homogeneous volumetric heat capacity. While the perfect cloak of inhomogeneous κ and inhomogeneous ρcp is known to be exact (no signals scattering and only mean values penetrating to the cloak's interior), the sensitivity of diffusive cloaks to defects and approximations has not been analyzed. We analytically demonstrate that these approximate cloaks are detectable. Although they work as perfect cloaks in the steady-state, their transient (time-dependent) response is imperfect and a small amount of heat is scattered. This is sufficient to determine the presence of a cloak and any heat source it contains, but the material composition hidden within the cloak is not detectable in practice. To demonstrate the feasibility of this technique, we constructed a cloak with similar approximation and directly detected its presence using these transient temperature deviations outside the cloak. Due to limitations in the range of experimentally accessible volumetric specific heats, our detection scheme should allow us to find any realizable cloak, assuming a sufficiently large temperature difference.

  1. Heritable Change Caused by Transient Transcription Errors

    PubMed Central

    Halliday, Jennifer A.; Herman, Christophe

    2013-01-01

    Transmission of cellular identity relies on the faithful transfer of information from the mother to the daughter cell. This process includes accurate replication of the DNA, but also the correct propagation of regulatory programs responsible for cellular identity. Errors in DNA replication (mutations) and protein conformation (prions) can trigger stable phenotypic changes and cause human disease, yet the ability of transient transcriptional errors to produce heritable phenotypic change (‘epimutations’) remains an open question. Here, we demonstrate that transcriptional errors made specifically in the mRNA encoding a transcription factor can promote heritable phenotypic change by reprogramming a transcriptional network, without altering DNA. We have harnessed the classical bistable switch in the lac operon, a memory-module, to capture the consequences of transient transcription errors in living Escherichia coli cells. We engineered an error-prone transcription sequence (A9 run) in the gene encoding the lac repressor and show that this ‘slippery’ sequence directly increases epigenetic switching, not mutation in the cell population. Therefore, one altered transcript within a multi-generational series of many error-free transcripts can cause long-term phenotypic consequences. Thus, like DNA mutations, transcriptional epimutations can instigate heritable changes that increase phenotypic diversity, which drives both evolution and disease. PMID:23825966

  2. Automated Classification of Transient and Variable Sources

    NASA Astrophysics Data System (ADS)

    Donalek, Ciro; Graham, M.; Mahabal, A. A.; Djorgovski, S. G.; Drake, A. J.; Yang, M.; Maker, A.; Duan, V.

    2013-01-01

    Better and faster technology is increasing the amount of collected data in many scientific fields, all of them requiring a common task: extract knowledge from massive, multi parametric data sets, as rapidly and efficiently possible. Most systems today rely on a delayed human judgment and this “manual” approach will simply not scale to the next generation of surveys thus the need of a machine learning approach. We present a sleeping expert framework that makes use of many different ensembles of classifiers (eg, kNN, Neural Networks, Bayesian Networks, Decision Trees) that can be activated according to the input data; results from the single classifiers are then combined in order to achieve a better classification rate. Using data sets extracted from the ongoing Catalina Real-Time Transient Surveys (CRTS), we show the results obtained applying this framework to different astronomical problems (eg, classifying transients on the basis of features describing the light curves, systematic search of CV). Moreover, we illustrate a variety of feature selection strategies used to identify the subsets that give the most information; given the high number of parameters this is quickly becoming a crucial task in analyzing astronomical data sets.

  3. Transient phenomena in rotary kiln incineration

    SciTech Connect

    Linak, W.P.; Kilgroe, J.D.; Wendt, J.O.; Mc Sorley, J.A.; Dunn, J.E.

    1986-01-01

    This paper describes results of an ongoing experimental investigation at the U.S. Environmental Protection Agency into the waste properties and kiln parameters that determine both the instantaneous intensity and the total magnitude of transient puffs leaving the kiln. The experimental apparatus utilized was a 73 kW (250,000 Btu/hr) laboratory rotary kiln simulator. Surrogate solid wastes in the form of plastic rods and surrogate liquid wastes on corncob sorbent in cardboard containers were investigated. A statistically designed parametric study was used to determine the extent to which waste and kiln variables (such as charge mass, charge surface area, charge composition, kiln temperature, and kiln rotation speed) affected the intensity (hydrocarbon peak height) and magnitude (hydrocarbon peak area) of puffs. Results demonstrate the relative ease with which failure conditions are achieved, even at high excess air values and high kiln temperatures. Transient puffs arising from even innocuous surrogate wastes can contain a number of hazardous compounds. Increasing kiln temperature and kiln rotation speed can cause an adverse effect on puff intensity, probably due to increased devolatilization rates.

  4. Nonlinear transient analysis of joint dominated structures

    NASA Technical Reports Server (NTRS)

    Chapman, J. M.; Shaw, F. H.; Russell, W. C.

    1987-01-01

    A residual force technique is presented that can perform the transient analyses of large, flexible, and joint dominated structures. The technique permits substantial size reduction in the number of degrees of freedom describing the nonlinear structural models and can account for such nonlinear joint phenomena as free-play and hysteresis. In general, joints can have arbitrary force-state map representations but these are used in the form of residual force maps. One essential feature of the technique is to replace the arbitrary force-state maps describing the nonlinear joints with residual force maps describing the truss links. The main advantage of this replacement is that the incrementally small relative displacements and velocities across a joint are not monitored directly thereby avoiding numerical difficulties. Instead, very small and 'soft' residual forces are defined giving a numerically attractive form for the equations of motion and thereby permitting numerically stable integration algorithms. The technique was successfully applied to the transient analyses of a large 58 bay, 60 meter truss having nonlinear joints. A method to perform link testing is also presented.

  5. Inferring sparse networks for noisy transient processes.

    PubMed

    Tran, Hoang M; Bukkapatnam, Satish T S

    2016-01-01

    Inferring causal structures of real world complex networks from measured time series signals remains an open issue. The current approaches are inadequate to discern between direct versus indirect influences (i.e., the presence or absence of a directed arc connecting two nodes) in the presence of noise, sparse interactions, as well as nonlinear and transient dynamics of real world processes. We report a sparse regression (referred to as the l1-min) approach with theoretical bounds on the constraints on the allowable perturbation to recover the network structure that guarantees sparsity and robustness to noise. We also introduce averaging and perturbation procedures to further enhance prediction scores (i.e., reduce inference errors), and the numerical stability of l1-min approach. Extensive investigations have been conducted with multiple benchmark simulated genetic regulatory network and Michaelis-Menten dynamics, as well as real world data sets from DREAM5 challenge. These investigations suggest that our approach can significantly improve, oftentimes by 5 orders of magnitude over the methods reported previously for inferring the structure of dynamic networks, such as Bayesian network, network deconvolution, silencing and modular response analysis methods based on optimizing for sparsity, transients, noise and high dimensionality issues. PMID:26916813

  6. Detecting Thermal Cloaks via Transient Effects

    PubMed Central

    Sklan, Sophia R.; Bai, Xue; Li, Baowen; Zhang, Xiang

    2016-01-01

    Recent research on the development of a thermal cloak has concentrated on engineering an inhomogeneous thermal conductivity and an approximate, homogeneous volumetric heat capacity. While the perfect cloak of inhomogeneous κ and inhomogeneous ρcp is known to be exact (no signals scattering and only mean values penetrating to the cloak’s interior), the sensitivity of diffusive cloaks to defects and approximations has not been analyzed. We analytically demonstrate that these approximate cloaks are detectable. Although they work as perfect cloaks in the steady-state, their transient (time-dependent) response is imperfect and a small amount of heat is scattered. This is sufficient to determine the presence of a cloak and any heat source it contains, but the material composition hidden within the cloak is not detectable in practice. To demonstrate the feasibility of this technique, we constructed a cloak with similar approximation and directly detected its presence using these transient temperature deviations outside the cloak. Due to limitations in the range of experimentally accessible volumetric specific heats, our detection scheme should allow us to find any realizable cloak, assuming a sufficiently large temperature difference. PMID:27605153

  7. Inferring sparse networks for noisy transient processes

    NASA Astrophysics Data System (ADS)

    Tran, Hoang M.; Bukkapatnam, Satish T. S.

    2016-02-01

    Inferring causal structures of real world complex networks from measured time series signals remains an open issue. The current approaches are inadequate to discern between direct versus indirect influences (i.e., the presence or absence of a directed arc connecting two nodes) in the presence of noise, sparse interactions, as well as nonlinear and transient dynamics of real world processes. We report a sparse regression (referred to as the -min) approach with theoretical bounds on the constraints on the allowable perturbation to recover the network structure that guarantees sparsity and robustness to noise. We also introduce averaging and perturbation procedures to further enhance prediction scores (i.e., reduce inference errors), and the numerical stability of -min approach. Extensive investigations have been conducted with multiple benchmark simulated genetic regulatory network and Michaelis-Menten dynamics, as well as real world data sets from DREAM5 challenge. These investigations suggest that our approach can significantly improve, oftentimes by 5 orders of magnitude over the methods reported previously for inferring the structure of dynamic networks, such as Bayesian network, network deconvolution, silencing and modular response analysis methods based on optimizing for sparsity, transients, noise and high dimensionality issues.

  8. Detecting Thermal Cloaks via Transient Effects.

    PubMed

    Sklan, Sophia R; Bai, Xue; Li, Baowen; Zhang, Xiang

    2016-01-01

    Recent research on the development of a thermal cloak has concentrated on engineering an inhomogeneous thermal conductivity and an approximate, homogeneous volumetric heat capacity. While the perfect cloak of inhomogeneous κ and inhomogeneous ρcp is known to be exact (no signals scattering and only mean values penetrating to the cloak's interior), the sensitivity of diffusive cloaks to defects and approximations has not been analyzed. We analytically demonstrate that these approximate cloaks are detectable. Although they work as perfect cloaks in the steady-state, their transient (time-dependent) response is imperfect and a small amount of heat is scattered. This is sufficient to determine the presence of a cloak and any heat source it contains, but the material composition hidden within the cloak is not detectable in practice. To demonstrate the feasibility of this technique, we constructed a cloak with similar approximation and directly detected its presence using these transient temperature deviations outside the cloak. Due to limitations in the range of experimentally accessible volumetric specific heats, our detection scheme should allow us to find any realizable cloak, assuming a sufficiently large temperature difference. PMID:27605153

  9. Detecting Thermal Cloaks via Transient Effects

    NASA Astrophysics Data System (ADS)

    Sklan, Sophia R.; Bai, Xue; Li, Baowen; Zhang, Xiang

    2016-09-01

    Recent research on the development of a thermal cloak has concentrated on engineering an inhomogeneous thermal conductivity and an approximate, homogeneous volumetric heat capacity. While the perfect cloak of inhomogeneous κ and inhomogeneous ρcp is known to be exact (no signals scattering and only mean values penetrating to the cloak’s interior), the sensitivity of diffusive cloaks to defects and approximations has not been analyzed. We analytically demonstrate that these approximate cloaks are detectable. Although they work as perfect cloaks in the steady-state, their transient (time-dependent) response is imperfect and a small amount of heat is scattered. This is sufficient to determine the presence of a cloak and any heat source it contains, but the material composition hidden within the cloak is not detectable in practice. To demonstrate the feasibility of this technique, we constructed a cloak with similar approximation and directly detected its presence using these transient temperature deviations outside the cloak. Due to limitations in the range of experimentally accessible volumetric specific heats, our detection scheme should allow us to find any realizable cloak, assuming a sufficiently large temperature difference.

  10. Experimental insights into transient volcanic eruption

    NASA Astrophysics Data System (ADS)

    Alatorre-Ibarguengoitia, M.; Scheu, B.; Dingwell, D. B.; Ramos-Hernandez, S.; de Arcia, P.

    2014-12-01

    The explosive expansion of mixtures of pressurized gases and pyroclasts within volcanic conduits and volcanic flows is a complex process that cannot be directly observed. Here, we present the results of shock-tube experiments with volcanic particles which exhibit remarkable similarities to the ejection dynamics of transient eruptions. Upon rapid decompression (from 2-11 MPa argon pressure to atmospheric pressure Pa = 0.1 MPa), loose particles are vertically accelerated and ejected into a large tank filled with air at atmospheric conditions. Our experimental results show that: 1) time-scales of the mechanical coupling between pyroclasts and the gas phase control the mixture dynamics and different regimes can be defined in terms of the Stokes number according to the particles grain-size; 2) As suggested by previous studies, we found that the pseudo-gas approximation is a reasonable approximation in transient eruptions only under certain conditions (constrained here experimentally); 3) the non-linear decay of the particles velocities with time is related with the conduit depth and the initial volume of the expanding material. Our results broaden the impact of previous experimental studies and provide fundamental information for numerical models of eruptive dynamics.

  11. Light Echoes of Transients and Variables

    NASA Astrophysics Data System (ADS)

    Rest, Armin

    2012-04-01

    abstract-type="normal">SummaryTycho Brahe's observations of a supernova in 1572 challenged the contemporaneous European view of the cosmos that the celestial realm was unchanging. 439 years later we have once again seen the light that Tycho saw, as some of the light from the 1572 supernova is reflected off dust and is only now reaching Earth. These light echoes, as well as ones detected from other transients and variables, give us a very rare opportunity in astronomy: direct observation of the cause (the supernova explosion) and the effect (the supernova remnant) of the same astronomical event. Furthermore, in some cases we can compare light echoes at different angles around a supernova remnant, and thus investigate possible asymmetry in the supernova explosion. In addition, in cases where the scattering dust is favorably positioned, the geometric distance to the SN remnant can be determined using polarization measurements. These techniques have been successfully applied to various transients in the last decade, and the talk gave an overview of the scientific results and techniques, with a particular focus on the challenges we will face in the current and upcoming wide-field time-domain surveys.

  12. Transient electrochemistry: beyond simply temporal resolution.

    PubMed

    Zhou, X-S; Mao, B-W; Amatore, C; Compton, R G; Marignier, J-L; Mostafavi, M; Nierengarten, J-F; Maisonhaute, E

    2016-01-01

    Some physicochemical intrigues for which transient electrochemistry was necessary to solve the problem are summarized in this feature article. First, we highlight the main constraints to be aware of to access to low time scales, and particularly focus on the effects of stray capacitances. Then, the electron transfer rate constant measured for redox molecules in a self-assembled monolayer configuration is compared to the conductance measured through the same systems, but at the single molecule level. This evidences strong conformational changes when molecules are trapped in the nanogap created between both electrodes. We also report about dendrimers, for which a short electrochemical perturbation induces creation of a diffusion layer within the molecule, allowing the electron hopping rate to be measured and analyzed in terms of molecular motions of the redox centers. Finally, we show that transient electrochemistry provides also useful information when coupled to other methodologies. For example, when an ultrasonic field drives very fast movements of a bubble situated above the electrode surface, the motion can be detected indirectly through a modification of the diffusion flux. Another field concerns pulse radiolysis, and we describe how the reactivity (at the electrode or within the solution) of radicals created by a radiolytic pulse can be quantified, widening the possibilities of electrochemistry to operate in biological media.

  13. GTRAN- TRANSIENT ANALYSIS OF GAS PIPING SYSTEMS

    NASA Technical Reports Server (NTRS)

    TROVILLION T A

    1994-01-01

    The GTRAN program was developed to solve transient, as well as steady state, problems for gas piping systems. GTRAN capabilities allow for the analysis of a variety of system configurations and components. These include: multiple pipe junctions; valves that change position with time; fixed restrictions (orifices, manual valves, filters, etc.); relief valves; constant pressure sources; and heat transfer for insulated piping and piping subjected to free or forced convection. In addition, boundary conditions can be incorporated to simulate specific components. The governing equations of GTRAN are the one-dimensional transient gas dynamic equations. The three equations for pressure, velocity, and density are reduced to numerical equations using an implicit Crank-Nicholson finite difference technique. Input to GTRAN includes a description of the piping network, the initial conditions, and any events (e.g. valve closings) occuring during the period of analysis. Output includes pressure, velocity, and density versus time. GTRAN is written in FORTRAN 77 for batch execution and has been implemented on a DEC VAX series computer. GTRAN was developed in 1983.

  14. Compact Femtosecond-Millisecond Transient Absorption Spectrometer

    NASA Astrophysics Data System (ADS)

    Carroll, Elizabeth; Hill, Melissa; Madsen, Dorte; Malley, Konstantin; Larsen, Delmar

    2008-03-01

    The measurement of population dynamics in biological, chemical, and solid-state samples occurring over 10-15-10^1 seconds requires a combination of transient absorption techniques, typically involving different laser systems and detection electronics (e.g. femtosecond transient absorption and nanosecond flash photolysis). The difficulty in exactly matching excitation conditions often prohibits connecting ultrafast and longer time measurements, particularly in samples exhibiting nonlinear kinetics. We present a simple solution to bridge the femtosecond and microsecond domains with an inexpensive modification of a kHz amplified Ti:Sapphire laser. By introducing a secondary pulse-picker between the laser oscillator (75 MHz) and amplifier, we can electronically delay unamplified 800-nm probe pulses in 13.3-ns steps. The 5-nJ pulses seed a photonic crystal fiber to produce a supercontinuum (450-1100 nm) for broadband probing. We demonstrate the system capability by resolving formation and decay dynamics, spanning 10 decades (10-14-10-4 s), of photoexcited solvated electrons in sinapic acid, and triplet states and quinonoid intermediates in Vitamin B6.

  15. Transient hyporeninemic hypoaldosteronism in acute glomerulonephritis.

    PubMed

    Watanabe, Toru; Nitta, Koju

    2002-11-01

    While hyporeninemic hypoaldosteronism (HH) has been well described in relation to chronic renal diseases, transient HH has rarely been reported. Here we present a 9-year-old boy with acute glomerulonephritis who developed hyperkalemia, which persisted for a period of 3 weeks despite normal values of creatinine clearance and an absence of acidosis. He was diagnosed as having HH because of low basal plasma renin activity and serum aldosterone level. Renal biopsy showed diffuse endocapillary proliferative glomerulonephritis. There were no apparent pathological changes in the juxtaglomerular apparatus (JGA). Rapid adrenocorticotropic hormone administration increased adequately both serum aldosterone and cortisol levels. Responses of both plasma renin activity and serum aldosterone level following the furosemide upright provocation were blunted in the hyperkalemic acute phase, but recovered in the normokalemic convalescent phase. Serum levels of human atrial natriuretic peptide were within normal range, both in the hyperkalemic and normokalemic phases. These results suggested that a transient dysfunction of the JGA, without volume expansion or structural damage of the JGA, caused HH in this patient.

  16. Fuzzy logic -- artificial neural networks integration for transient identification

    SciTech Connect

    Ikonomopoulos, A.; Tsoukalas, L.H. . Dept. of Nuclear Engineering); Uhrig, R.E. . Dept. of Nuclear Engineering Oak Ridge National Lab., TN )

    1991-01-01

    A methodology is presented that integrates pretrained artificial neural networks (ANNs) with rule-based fuzzy logic systems, for the purpose of distinguishing different transients in a Nuclear Power Plant (NPP). In general this approach appears to provide timely, concise and task specific information about the status of a system under consideration. The pretrained neural network typifies different transient scenarios and derives membership functions which independently represent individual transients. The overall system successfully performs transient identification, in a time span faster or at least comparable to that of transient development. In order to examine the proposed methodology simulated accidents are used. The results obtained demonstrate the excellent noise tolerance of ANNs and suggest a new approach for transient identification.

  17. Fuzzy logic -- artificial neural networks integration for transient identification

    SciTech Connect

    Ikonomopoulos, A.; Tsoukalas, L.H.; Uhrig, R.E. |

    1991-12-31

    A methodology is presented that integrates pretrained artificial neural networks (ANNs) with rule-based fuzzy logic systems, for the purpose of distinguishing different transients in a Nuclear Power Plant (NPP). In general this approach appears to provide timely, concise and task specific information about the status of a system under consideration. The pretrained neural network typifies different transient scenarios and derives membership functions which independently represent individual transients. The overall system successfully performs transient identification, in a time span faster or at least comparable to that of transient development. In order to examine the proposed methodology simulated accidents are used. The results obtained demonstrate the excellent noise tolerance of ANNs and suggest a new approach for transient identification.

  18. Elektrische Phänomene des Körpers und ihre Detektion

    NASA Astrophysics Data System (ADS)

    Bolz, Armin; Kikillus, Nicole; Moor, Claudius

    Im menschlichen Körper verfügen sowohl Nerven- als auch Muskelzellen über die Eigenschaft, intra- und extrazelluläre Ionenkonzentrationen zu verschieben und damit die Potenzialverteilung in ihrer Umgebung zu beeinflussen. Über unterschiedliche Synchronisationsverfahren sind makroskopische Zellverbände zusätzlich in der Lage, koordiniert ihre Felder zu verändern und somit auch signifikante, an der Körperoberfläche messbare elektrische Signale zu erzeugen. Das vorliegende Kapitel beschreibt zunächst die elektrophysiologischen Grundlagen elektrischer Signale des menschlichen Körpers, die Synchronisationsmechanismen und die daraus entstehenden Felder, insbesondere das Elektrokardiogramm (EKG), das Elektroenzephalogramm (EEG) sowie das Elektromyogramm (EMG). Im Anschluss daran werden die wesentlichen Grundlagen der Messtechnik zur Erfassung bioelektrischer Phänomene erläutert. Einige Beispielapplikationen runden diesen Beitrag ab.

  19. Modulare LDAP-Server-, -Protokoll und - Funktionserweiterungen am Beispiel von OpenLDAP

    NASA Astrophysics Data System (ADS)

    Pluta, Daniel

    In diesem Artikel wird ein Standardisierungsvorschlag für eine LDAP-Protokollerweiterung und deren Referenzimplementierung in Form einer modularen Erweiterung für die LDAP-Software-Suite des OpenLDAPProjektes vorgestellt. Nach einer Einführung in und einem Überblick über die wichtigsten OpenLDAP-Komponenten stellen wir unseren Lösungsansatz vor und gehen auf seine technischen Details ein. Ziel dieses Overlays ist die Implementierung einer neuen Funktionalität, die vom LDAP-Protokoll bisher nicht vorgesehen ist: Der Umfang der Suchergebnismenge soll serverseitig, dezentral und in der Granularität ganzer Objekte in Abhängigkeit von der aktuellen Serverzeit (konfigurierbar) eingeschränkt werden.

  20. Kosteneffiziente Honbearbeitung durch intelligente und flexible Verknüpfung von autarken Honzentren

    NASA Astrophysics Data System (ADS)

    Roth, Günther

    Die Planungsabteilungen in der Automobilindustrie werden vor immer größere Herausforderungen gestsellt. Der zur Verfügung stehende Zeitraum zu einer seriensicheren Umsetzung der entwicklungs- und produktionstechnischen Forderungen wird von Projekt zu Projekt kürzer. Aufgrund des hohen Wettbewerbsdrucks und daraus resultierenden erforderlichen Kostenoptimierungen, die schnelleren Timeto-market-und Innovationszyklen und die vermeintlich zur Kundenbindung erforderlichen, kaum mehr überschaubaren Diversifizierungen in den Modellpaletten lassen den Planungshorizont immer kürzer werden. Die zu beschaffenden Fertigungsanlagen sollen aber in den nächsten 8-12 Jahren all die Varianten produzieren können, die heute nur teilweise oder noch gar nicht bekannt sind.

  1. Jahre Entwicklung der Instandhaltung - von der ausfallorientierten Instandhaltung zum gemeinsamen TPM und RCM

    NASA Astrophysics Data System (ADS)

    Iske, Friedhelm

    Zur Einleitung meines Beitrages möchte ich von einem Gespräch mit einem Mitarbeiter berichten, das ich als junger Vorgesetzter einer Instandhaltungsgruppe 1988 führte. Der engagierte Mitarbeiter feierte damals sein vierzigjähriges Dienstjubiläum und war stolz auf das von ihm Geleistete sowie auf den besonderen Einsatz seiner Altersgruppe, die nach dem Zweiten Weltkrieg das Werk wieder aufgebaut hatte. Auf meine Frage, was denn damals die erste Aufgabe in der Firma war, bekam ich kurz und knapp und mit einer Selbstverständlichkeit die selbstbewusste Antwort: "Unser Pferd füttern und mit dem Pferd die innerbetrieblichen Transporte erledigen“. Als junger, technisch orientierter Vorgesetzter war ich über diese Antwort sehr überrascht. Gedanklich weit entfernt war die Vorstellung, dass in der Vergangenheit Transporte mit einem Pferd erledigt wurden.

  2. Classification of Transient Phenomena in Distribution System using wavelet Transform

    NASA Astrophysics Data System (ADS)

    Sedighi, Alireza

    2014-05-01

    An efficient procedure for classification of transient phenomena in distribution systems is proposed in this paper. The proposed method has been applied to classify some transient phenomena such as inrush current, load switching, capacitor switching and single phase to ground fault. The new scheme is based on wavelet transform algorithm. All of the events for feature extraction and test are simulated using Electro Magnetic Transient Program (EMTP). Results show high accuracy of proposed method.

  3. Integrated transient thermal-structural finite element analysis

    NASA Technical Reports Server (NTRS)

    Thornton, E. A.; Dechaumphai, P.; Wieting, A. R.; Tamma, K. K.

    1981-01-01

    An integrated thermal structural finite element approach for efficient coupling of transient thermal and structural analysis is presented. Integrated thermal structural rod and one dimensional axisymmetric elements considering conduction and convection are developed and used in transient thermal structural applications. The improved accuracy of the integrated approach is illustrated by comparisons with exact transient heat conduction elasticity solutions and conventional finite element thermal finite element structural analyses.

  4. Simulation of centrifugal compressor transient performance for process plant applications

    SciTech Connect

    MacDougal, I.; Elder, R.L.

    1983-01-01

    The development of a theoretical model capable of simulating centrifugal compressor transient performance (including compressor surge) is detailed. Simulation results from a Fortran computer program are compared with measured compressor transient data. Good simulation of compressor transients between stable operating points, and compressor presurge flow oscillations has been obtained. General application criteria are presented for the geometric distribution of model elements within a compressor system. Model applications and future work are outlined.

  5. Highlights of Transient Plume Impingement Model Validation and Applications

    NASA Technical Reports Server (NTRS)

    Woronowicz, Michael

    2011-01-01

    This paper describes highlights of an ongoing validation effort conducted to assess the viability of applying a set of analytic point source transient free molecule equations to model behavior ranging from molecular effusion to rocket plumes. The validation effort includes encouraging comparisons to both steady and transient studies involving experimental data and direct simulation Monte Carlo results. Finally, this model is applied to describe features of two exotic transient scenarios involving NASA Goddard Space Flight Center satellite programs.

  6. Searching for Low-Frequency Radio Transients from Supernovae

    NASA Astrophysics Data System (ADS)

    Tsai-Wei, Jr.; Cutchin, Sean; Kothari, Manthan; Schmitt, Christian; Kavic, Michael; Simonetti, John

    2011-10-01

    Supernovae events may be accompanied by prompt emission of a low-frequency electromagnetic transient. These transient events are created by the interaction of a shock wave of charged particles created by SN core-collapse with a stars ambient magnetic field. Such events can be detected in low-frequency radio array. Here we discuss an ongoing search for such events using two radio arrays: the Long Wavelength Array (LWA) and Eight-meter-wavelength Transient Array (ETA).

  7. Laser-induced transient grating setup with continuously tunable period

    SciTech Connect

    Vega-Flick, A.; Eliason, J. K.; Maznev, A. A.; Nelson, K. A.; Khanolkar, A.; Abi Ghanem, M.; Boechler, N.; Alvarado-Gil, J. J.

    2015-12-15

    We present a modification of the laser-induced transient grating setup enabling continuous tuning of the transient grating period. The fine control of the period is accomplished by varying the angle of the diffraction grating used to split excitation and probe beams. The setup has been tested by measuring dispersion of bulk and surface acoustic waves in both transmission and reflection geometries. The presented modification is fully compatible with optical heterodyne detection and can be easily implemented in any transient grating setup.

  8. Three-dimensional transient analysis capability in SIMULATE-3

    SciTech Connect

    Borkowski, J.; Rhodes, J. III; Esser, P.; Smith, K.

    1994-12-31

    Transient analysis capability has been added to the advanced nodal methodology of SIMULATE-3. The transient modules couple a transient version of the steady-state nodal method QPANDA with a one-dimensional, bundle-by-bundle thermal-hydraulic feedback module. The accuracy of the code has been assessed by using several benchmark problems, including the LMW benchmark and the Nuclear Energy Agency Committee on Reactor Physics (NEACRP) pressurized water reactor (PWR) rod ejection benchmarks.

  9. Applying hydraulic transient analysis: The Grizzly Hydro Project

    SciTech Connect

    Logan, T.H.; Stutsman, R.D. )

    1992-04-01

    No matter the size of the hydro plant, if it has a long waterway and will operate in peaking mode, the project designer needs to address the issue of hydraulic transients-known as water hammer-early in the design. This article describes the application of transient analysis to the design of a 20-MW hydro plant in California. In this case, a Howell Bunger valve was used as a pressure regulating valve to control transient pressures and speed rise.

  10. Transient Phenomena in Multiphase and Multicomponent Systems: Research Report

    NASA Astrophysics Data System (ADS)

    Zur Beurteilung von Stoffen in der Landwirtschaft, Senatskommission

    2000-09-01

    Due to the reinforced risk and safety-analysis of industrial plants in chemical and energy-engineering there has been increased demand in industry for more information on thermo- and fluiddynamic effects of non-equilibria during strong transients. Therefore, the 'Deutsche Forschungsgemeinschaft' initiated a special research program focusing on the study of transient phenomena in multiphase systems with one or several components. This book describes macroscopic as well as microscopic transient situations. A large part of the book deals with numerical methods for describing transients in two-phase mixtures. New developments in measuring techniques are also presented.

  11. Transients in the synchronization of asymmetrically coupled oscillator arrays

    NASA Astrophysics Data System (ADS)

    Cantos, C. E.; Hammond, D. K.; Veerman, J. J. P.

    2016-09-01

    We consider the transient behavior of a large linear array of coupled linear damped harmonic oscillators following perturbation of a single element. Our work is motivated by modeling the behavior of flocks of autonomous vehicles. We first state a number of conjectures that allow us to derive an explicit characterization of the transients, within a certain parameter regime Ω. As corollaries we show that minimizing the transients requires considering non-symmetric coupling, and that within Ω the computed linear growth in N of the transients is independent of (reasonable) boundary conditions.

  12. Fundamental study on transient bubble (slug) behavior by characterizing transient forces of solid particles in fluidized beds

    SciTech Connect

    Kono, H.O.

    1991-01-01

    The objective of this work is to recognize and interpret the signals of transient motion of bubbles (slugs) in fluidized beds by measuring and utilizing the signals of transient motion of solid particles. The two signals were measured simultaneously and also synchronized by using the TTL signal technique in the same fluidized beds. Also, a simultaneous study of video bubble image, transient force and pressure signals was initiated in a two dimensional fluidized bed. we successfully synchronized three signals so that the relationship of bubble behavior and force pressure signals can be identified and characterized. It has been found that bubble image can well be correlated to the transient force signal of solid particles under certain conditions in three dimensional fluidized beds. Accordingly, it seems that the transient force signals can significantly help understanding the transient motion of bubbles (slugs), which is important to design the fluidized beds.

  13. Fundamental study on transient bubble (slug) behavior by characterizing transient forces of solid particles in fluidized beds. 1990 Annual report

    SciTech Connect

    Kono, H.O.

    1991-01-01

    The objective of this work is to recognize and interpret the signals of transient motion of bubbles (slugs) in fluidized beds by measuring and utilizing the signals of transient motion of solid particles. The two signals were measured simultaneously and also synchronized by using the TTL signal technique in the same fluidized beds. Also, a simultaneous study of video bubble image, transient force and pressure signals was initiated in a two dimensional fluidized bed. we successfully synchronized three signals so that the relationship of bubble behavior and force pressure signals can be identified and characterized. It has been found that bubble image can well be correlated to the transient force signal of solid particles under certain conditions in three dimensional fluidized beds. Accordingly, it seems that the transient force signals can significantly help understanding the transient motion of bubbles (slugs), which is important to design the fluidized beds.

  14. Schönheit und andere Provokationen - Eine neue evolutionsbiologische Theorie der Kunst

    NASA Astrophysics Data System (ADS)

    Junker, Thomas

    Die Evolution hat viele spektakuläre Phänomene hervorgebracht - von der Eleganz des Vogelflugs über die gigantischen Körper der Dinosaurier und die farbenprächtige Vielfalt der Korallenriffe bis hin zu ihrem jüngsten Geniestreich - der menschlichen Kunst. Die schönen Künste - Malerei, Bildhauerei und Architektur, Theater, Tanz, Oper und Filmkunst, Musik und Literatur - Produkte der Evolution? Diese Vorstellung mutet vielen Menschen fremd an, aber wie könnte es anders sein? Denn wenn Charles Darwin recht hat, dann sind nicht nur die körperlichen Merkmale der Menschen als Antworten auf die Erfordernisse des Lebens entstanden, sondern auch ihre geistigen Fähigkeiten und Verhaltensweisen. Im Jahr 1859 hatte er auf den letzten Seiten seines berühmten Buches über die Entstehung der Arten eine kühne Prophezeiung gemacht: Durch die Evolutionstheorie werde es "zu einer bemerkenswerten Revolution in der Naturwissenschaft kommen […]. Die Psychologie wird auf die neue Grundlage gestellt, dass jede geistige Kraft und Fähigkeit notwendigerweise durch graduelle Übergänge erworben wird“ (Darwin 1859, S. 484, 488; Junker 2008).

  15. Transient growth of damped baroclinic waves

    NASA Technical Reports Server (NTRS)

    Farrell, B.

    1985-01-01

    A solution of the linear initial value problem for the model of Eady with the inclusion of Ekman damping is presented. This model exhibits large transient growth of perturbations for synoptic cyclone spatial scales and a realistic value of the vertical turbulent viscosity coefficient despite the fact that all normal modes are exponentially decaying. Similar results are found for the model of Charney, implying that exponential instability cannot, in general, serve to explain the occurrence of cyclone scale disturbances in midlatiudes. Rather these are seen to arise additionally and perhaps predominantly from the release of mean flow potential energy by favorably configured initial perturbations. The Petterssen criterion for midlatitude cyclogenesis results naturally from this development as does its extension to the formation of subtropical monsoon depressions. Implications for the maintenance of midlatitude temperature gradients are discussed.

  16. Recurrences of transient synovitis of the hip.

    PubMed Central

    Illingworth, C M

    1983-01-01

    Thirty six children with transient synovitis of the hip had a total of 80 recurrences, 69 of them personally observed, and 11 described by the mother. No features distinguished the initial attack of those who had a recurrence from that of the 18 children who have not so far had a recurrence. We analysed the total of 126 episodes. In 72 there was evidence of an associated infection from the history, clinical signs, and a raised antistreptolysin O titre or isolation of a pathogen from a throat swab. The prognosis is difficult to assess because the symptoms, signs, and special investigations are not specific. Recurrences can occur after many years without symptoms. PMID:6614977

  17. The Swift Burst and Transient Telescope (BAT)

    NASA Technical Reports Server (NTRS)

    Mushotzky, Richard

    2008-01-01

    The Swift Burst and Transient telescope (BAT) has surveyed the entire sky for the last 3.5 years obtaining the first sensitive all sky survey of the 14-195 kev sky. At high galactic latitudes the vast majority of the detected sources are AGN. Since hard x-rays penetrate all but Compton thick obscuring material (Column densities of 1.6324 atms/sq cm) this survey is unbiased with respect to obscuration, host galaxy type, optical , radio or IR properties. We will present results on the broad band x-ray properties, the nature of the host galaxies, the luminosity function and will discuss a few of the optical, IR and x-ray results in detail.

  18. Monitoring transients in low inductance circuits

    DOEpatents

    Guilford, Richard P.; Rosborough, John R.

    1987-01-01

    A pair of flat cable transmission lines are monitored for transient current spikes by using a probe connected to a current transformer by a pickup loop and monitoring the output of the current transformer. The approach utilizes a U-shaped pickup probe wherein the pair of flat cable transmission lines are received between the legs of the U-shaped probe. The U-shaped probe is preferably formed of a flat coil conductor adhered to one side of a flexible substrate. On the other side of the flexible substrate there is a copper foil shield. The copper foil shield is connected to one end of the flat conductor coil and connected to one leg of the pickup loop which passes through the current transformer. The other end of the flat conductor coil is connected to the other leg of the pickup loop.

  19. Delayed transient post-traumatic quadriplegia.

    PubMed

    Al-Shaaibi, Khaloud; Kariyattil, Rajeev

    2015-03-01

    Transient neurological deficit following cervical trauma have been reported following sports injuries, and has been referred to as cervical cord neurapraxia. The so-called "whiplash injuries" following minor motor vehicle collisions usually do not produce any neurological deficit. Here we report the case of a whiplash type of injury presenting with a delayed onset neurological deficit, which was followed by rapid and complete recovery. The patient, an otherwise healthy 34-year-old male, attended the emergency department of Sultan Qaboos University Hospital following a rear-end motor vehicle collision. We present images showing degenerative disc disease causing spinal canal narrowing and mild cord compression in the patient, but no spinal instability. Differential diagnoses are also discussed. PMID:25960840

  20. Transient Analysis of a Magnetic Heat Pump

    NASA Technical Reports Server (NTRS)

    Schroeder, E. A.

    1985-01-01

    An experimental heat pump that uses a rare earth element as the refrigerant is modeled using NASTRAN. The refrigerant is a ferromagnetic metal whose temperature rises when a magnetic field is applied and falls when the magnetic field is removed. The heat pump is used as a refrigerator to remove heat from a reservoir and discharge it through a heat exchanger. In the NASTRAN model the components modeled are represented by one-dimensional ROD elements. Heat flow in the solids and fluid are analyzed. The problem is mildly nonlinear since the heat capacity of the refrigerant is temperature-dependent. One simulation run consists of a series of transient analyses, each representing one stroke of the heat pump. An auxiliary program was written that uses the results of one NASTRAN analysis to generate data for the next NASTRAN analysis.

  1. [Cerebral infarction and transient ischemic attack].

    PubMed

    Sahara, Noriyuki; Kuwashiro, Takahiro; Okada, Yasushi

    2016-04-01

    Japanese Guidelines for the Management of Stroke 2015 was published. Here, we describe several points revised from the 2009 edition about "Cerebral infarction and transient ischemic attack (TIA)". The revision points are as follows; 1. Extension of possible time window of intravenous recombinant tissue-plasminogen activator treatment (from within 3 hours to within 4.5 hours); 2. Antiplatelet therapy in acute stage (dual antiplatelet therapy (DAPT) for non-cardioembolic ischemic stroke or TIA); 3. Endovascular recanalization therapy in acute stage; 4. Antiplatelet therapy in chronic stage (Cilostazol is recommended similar to aspirin or clopidogrel); 5. Non-vitamin K antagonist oral anticoagulants (NOACs) for non-valvular atrial fibrillation (NVAF) stroke or TIA patients; 6. Management of TIA. We explain the revised points of the guideline in the text.

  2. FibroScan® and transient elastography.

    PubMed

    Kemp, William; Roberts, Stuart

    2013-07-01

    The use of non-invasive tests to stage the severity of liver disease (ie. scarring) is now well established in the management of patients with chronic liver disease. This is because assessment of liver scarring provides prognostic information and assists in establishing treatment priorities. One such technique, transient elastography (TE), is a simple, safe and efficient way to estimate liver scarring. FibroScan® (EchoSens, Paris) is the most popular non-invasive device used to assess liver 'hardness' (or stiffness) via TE in Australia. When performed in the appropriate clinical setting, TE provides a reliable method of detecting cirrhosis and excluding significant fibrosis, particularly when the results are supported by clinical and laboratory data.

  3. Characteristics of Transient Boiling Heat Transfer

    SciTech Connect

    Liu, Wei; Monde, Masanori; Mitsutake, Y.

    2002-07-01

    In this paper, one dimensional inverse heat conduction solution is used for a measurement of pool boiling curve. The experiments are performed under atmospheric pressure for copper, brass, carbon steel and gold. Boiling curves, including unsteady transition boiling region, are found can be traced fairly well from a simple experiment system by solving inverse heat conduction solution. Boiling curves for steady heating and transient heating, for heating process and cooling process are compared. Surface behavior around CHF point, transition boiling and film-boiling regions are observed by using a high-speed camera. The results show the practicability of the inverse heat conduction solution in tracing boiling curve and thereby supply us a new way in boiling heat transfer research. (authors)

  4. A magnetohydrodynamic theory of coronal loop transients

    NASA Technical Reports Server (NTRS)

    Yeh, T.

    1982-01-01

    The physical and geometrical characteristics of solar coronal loop transients are described in an MHD model based on Archimedes' MHD buoyancy force. The theory was developed from interpretation of coronagraphic data, particularly from Skylab. The brightness of a loop is taken to indicate the electron density, and successive pictures reveal the electron enhancement in different columns. The forces which lift the loop off the sun surface are analyzed as an MHD buoyancy force affecting every mass element by imparting an inertial force necessary for heliocentrifugal motion. Thermal forces are responsible for transferring the ambient stress to the interior of the loop to begin the process. The kinematic and hydrostatic buoyancy overcome the gravitational force, and a flux rope can then curve upward, spiralling like a corkscrew with varying cross section around the unwinding solar magnetic field lines.

  5. Electron Acceleration by Transient Ion Foreshock Phenomena

    NASA Astrophysics Data System (ADS)

    Wilson, L. B., III; Turner, D. L.

    2015-12-01

    Particle acceleration is a topic of considerable interest in space, laboratory, and astrophysical plasmas as it is a fundamental physical process to all areas of physics. Recent THEMIS [e.g., Turner et al., 2014] and Wind [e.g., Wilson et al., 2013] observations have found evidence for strong particle acceleration at macro- and meso-scale structures and/or pulsations called transient ion foreshock phenomena (TIFP). Ion acceleration has been extensively studied, but electron acceleration has received less attention. Electron acceleration can arise from fundamentally different processes than those affecting ions due to differences in their gyroradii. Electron acceleration is ubiquitous, occurring in the solar corona (e.g., solar flares), magnetic reconnection, at shocks, astrophysical plasmas, etc. We present new results analyzing the dependencies of electron acceleration on the properties of TIFP observed by the THEMIS spacecraft.

  6. Robust optimization with transiently chaotic dynamical systems

    NASA Astrophysics Data System (ADS)

    Sumi, R.; Molnár, B.; Ercsey-Ravasz, M.

    2014-05-01

    Efficiently solving hard optimization problems has been a strong motivation for progress in analog computing. In a recent study we presented a continuous-time dynamical system for solving the NP-complete Boolean satisfiability (SAT) problem, with a one-to-one correspondence between its stable attractors and the SAT solutions. While physical implementations could offer great efficiency, the transiently chaotic dynamics raises the question of operability in the presence of noise, unavoidable on analog devices. Here we show that the probability of finding solutions is robust to noise intensities well above those present on real hardware. We also developed a cellular neural network model realizable with analog circuits, which tolerates even larger noise intensities. These methods represent an opportunity for robust and efficient physical implementations.

  7. Transient Loschmidt echo in quenched Ising chains

    NASA Astrophysics Data System (ADS)

    Lupo, Carla; Schiró, Marco

    2016-07-01

    We study the response to sudden local perturbations of highly excited quantum Ising spin chains. The key quantity encoding this response is the overlap between time-dependent wave functions, which we write as a transient Loschmidt Echo. Its asymptotics at long time differences contain crucial information about the structure of the highly excited nonequilibrium environment induced by the quench. We compute the echo perturbatively for a weak local quench but for arbitrarily large global quench, using a cumulant expansion. Our perturbative results suggest that the echo decays exponentially, rather than power law as in the low-energy orthogonality catastrophe, a further example of quench-induced decoherence already found in the case of quenched Luttinger liquids. The emerging decoherence scale is set by the strength of the local potential and the bulk excitation energy.

  8. Transient myeloproliferative disorder with partial trisomy 21.

    PubMed

    Takahashi, Takahide; Inoue, Akira; Yoshimoto, Junko; Kanamitsu, Kiichiro; Taki, Tomohiko; Imada, Masahide; Yamada, Mutsuko; Ninomiya, Shinsuke; Toki, Tsutomu; Terui, Kiminori; Ito, Etsuro; Shimada, Akira

    2015-11-01

    Myeloid malignancy with Down syndrome (ML-DS) is estimated to have a step-wise leukemogenesis including GATA1 mutation. Trisomy 21 is essential for ML-DS; however, we do not know exactly which gene or genes located on chromosome 21 are necessary for the ML-DS. We report a female infant with transient myeloproliferative disorder (TMD) and partial trisomy 21. SNP array analysis showed 10 Mb amplification of 21q22.12-21q22.3, which included DYRK1A, ERG, and ETS but not the RUNX1 gene. With two other reported TMD cases having partial trisomy 21, DYRK1A, ERG, and ETS were the most likely genes involved in collaboration with the GATA1 mutation. PMID:26138905

  9. Transient Radiation Darkening Features in VISAR Window

    SciTech Connect

    G. D. Stevens; K. J. Moy

    2001-06-01

    We have studied and characterized radiation-induced changes in the index of refraction of materials used in Z experiments. Interferometric measurements of the radiation-induced change in the real part, n, of the complex index of refraction, N = n + iK, have been made in lithium fluoride (LiF), sapphire, and fused silica samples. Our results indicate that the index changes are small, with {delta}n/n {approx} 1 x 10{sup -5}/kGy. In addition, we have characterized the dose dependence of the radiation-induced transient radiation darkening (TRD) of these materials, which is related to K, the imaginary part of the refractive index. We have also measured time-resolved spectral profiles of TRD in LiF and sapphire, and have examined the results in terms of known color centers and possible colloid aggregation.

  10. Fetal cytomegalovirus infection manifesting as transient pancytopenia.

    PubMed

    Kiyokoba, Ryo; Hidaka, Nobuhiro; Sakata, Yukiyo; Hachisuga, Kazuhisa; Fukushima, Kotaro; Kato, Kiyoko

    2015-08-01

    We encountered a patient with a fetal cytomegalovirus infection manifesting as pancytopenia and thoracic hypoplasia. The fetal anemia was treated by transfusion via the umbilical cord, and did not progress after 22 weeks' gestation. The neutropenia resolved spontaneously, and only thrombocytopenia was persistent at birth. The severe thoracic hypoplasia led to pulmonary hypertension and required intensive postnatal respiratory management. Our experience suggests that pancytopenia is a possible manifestation in fetuses infected with cytomegalovirus. This may be transient, resolving spontaneously during fetal life; however, caution should be taken with blood counts, particularly platelet counts, after delivery. In addition, clinicians should carefully follow the thoracic volume in cytomegalovirus-infected fetuses and consider the possibility of postnatal severe respiratory insufficiency.

  11. Deep level transient spectroscopy in resistive layers

    SciTech Connect

    Hunt, C.E.; Ng, Kim . Dept. of Electrical and Computer Engineering)

    1989-06-01

    This work investigates the application of the Deep Level Transient Spectroscopy (DLTS) technique to resistive semiconductor thin films, such as Silicon-On-Insulator (SOI) and thin layer of GaAs formed on semi-insulating material. Schottky diodes made on these materials were used in this study. The effect of the series resistance inherent in these types of thin-film test structures on the interpretation of data obtained from the measurement apparatus is discussed. It is observed that inverted DLTS signals occur in these structures because of the high series resistance. It is shown that ignoring this effect can lead to erroneous values of the activation energy and the density of traps. 2 refs.

  12. Solar transients due to cometary impacts

    NASA Astrophysics Data System (ADS)

    Ibadov, Subhon; Ibodov, Firuz

    2016-07-01

    It is analytically shown that cometary impact with the Sun at high velocities (about 600 km/s) leads, due to such aerodynamic effects as the nucleus crushing and transversal expansion of the crushed mass within the solar chromosphere, to impulse generation of hot, 10^7 K, plasma owing to fast thermalization of the comet nucleus kinetic energy in a relatively very thin layer near solar photosphere: solar transient. This process includes also generation of a strong shock wave and eruption of hot photospheric-comet nucleus matter into space above the solar chromosphere. Coordinated spectral observations of sun-grazing /impacting comets and solar flares with high-resolution space telescopes like SDO are of interest for the physics of comets as well as prognosis of solar flares.

  13. TRUMP. Transient & S-State Temperature Distribution

    SciTech Connect

    Elrod, D.C.; Turner, W.D.

    1992-03-03

    TRUMP solves a general nonlinear parabolic partial differential equation describing flow in various kinds of potential fields, such as fields of temperature, pressure, or electricity and magnetism; simultaneously, it will solve two additional equations representing, in thermal problems, heat production by decomposition of two reactants having rate constants with a general Arrhenius temperature dependence. Steady-state and transient flow in one, two, or three dimensions are considered in geometrical configurations having simple or complex shapes and structures. Problem parameters may vary with spatial position, time, or primary dependent variables, temperature, pressure, or field strength. Initial conditions may vary with spatial position, and among the criteria that may be specified for ending a problem are upper and lower limits on the size of the primary dependent variable, upper limits on the problem time or on the number of time-steps or on the computer time, and attainment of steady state.

  14. [Cerebral infarction and transient ischemic attack].

    PubMed

    Sahara, Noriyuki; Kuwashiro, Takahiro; Okada, Yasushi

    2016-04-01

    Japanese Guidelines for the Management of Stroke 2015 was published. Here, we describe several points revised from the 2009 edition about "Cerebral infarction and transient ischemic attack (TIA)". The revision points are as follows; 1. Extension of possible time window of intravenous recombinant tissue-plasminogen activator treatment (from within 3 hours to within 4.5 hours); 2. Antiplatelet therapy in acute stage (dual antiplatelet therapy (DAPT) for non-cardioembolic ischemic stroke or TIA); 3. Endovascular recanalization therapy in acute stage; 4. Antiplatelet therapy in chronic stage (Cilostazol is recommended similar to aspirin or clopidogrel); 5. Non-vitamin K antagonist oral anticoagulants (NOACs) for non-valvular atrial fibrillation (NVAF) stroke or TIA patients; 6. Management of TIA. We explain the revised points of the guideline in the text. PMID:27333757

  15. Isolated unilateral idiopathic transient hypoglossal nerve palsy

    PubMed Central

    Ahmed, Syed Viqar; Akram, Muhammad Saqub

    2014-01-01

    A 52-year-old Caucasian man presented with sudden onset of difficulty in moving his tongue to the left with preceding left-sided headache with no neck pain. Earlier, he had self-limiting chest infection without rashes or tonsillar enlargement. His medical and surgical history was unremarkable with no recent trauma. Oral examination revealed difficulty in protruding his tongue to the left with muscle bulk loss and fasciculation on the same side, suggesting left hypoglossal nerve palsy. Examination of the rest of the cranial nerves and nervous system was normal. The patient's oropharyngeal and laryngeal examination was unremarkable with no cervical lymphadenopathy. He had normal laboratory investigations and cerebrospinal fluid examination. Extensive imaging of the head, neck and chest failed to reveal any pathology. Further review by an otorhinologist and rheumatologist ruled out any other underlying pathology. He made a good recovery without treatment. English literature search revealed very few cases of idiopathic, transient, unilateral hypoglossal nerve palsy. PMID:24969070

  16. Transient simulation of superconducting synchronous machines

    NASA Astrophysics Data System (ADS)

    Koronides, A. G.

    1980-11-01

    A computer model is developed to study the electromechanical interactions between superconducting generators and power systems during various fault conditions. A large set of equivalent circuits is used to represent the eddy currents on the finite length electromagnetic cylindrical shields which surround the superconducting field winding. The armature and field windings are represented by coupled circuits as in conventional generator models. The rotor turbine shaft dynamics are introduced in the model by a set of lumped masses representing the various stages of the turbine and the rotor, connected by springs representing the shaft. The electrical and mechanical equations of the machine are related by the air gap torque equation in a large system of simultaneous, nonlinear differential equations. The developed computer algorithms used to study the transient behavior of a 300 MCA superconducting generator and the results are reported.

  17. A Catalog of Coronal "EIT Wave" Transients

    NASA Technical Reports Server (NTRS)

    Thompson, B. J.; Myers, D. C.

    2005-01-01

    SOHO Extreme Ultraviolet Imaging Telescope (EIT) data have been visually searched for coronal "EIT wave" transients over the period beginning 24 March 1997 extending through 24 June 1998. The dates covered start at the beginning of regular high-cadence (more than 1 image every 20 minutes) observations, ending at the 4-month interruption of SOHO observations in mid-1998. 176 events are included in this catalog. The observations range from "candidate" events, which were either weak or had insufficient data coverage, to events which were well-defined and were clearly distinguishable in the data. Included in the catalog are times of the EIT images in which the events are observed, diagrams indicating the observed locations of the wavefronts and associated active regions, and the speeds of the wavefronts. The measured speeds of the wavefronts varied from less than 50 to over 700 km/sec with "typical" speeds of 200-400 Msec.

  18. Transient aero-thermal simulations for TMT

    NASA Astrophysics Data System (ADS)

    Vogiatzis, Konstantinos

    2014-08-01

    Aero-thermal simulations are an integral part of the design process for the Thirty Meter Telescope (TMT). These simulations utilize Computational Solid-Fluid Dynamics (CSFD) to estimate wind jitter and blur, dome and mirror seeing, telescope pointing error due to thermal drift, and to predict thermal effects on performance of components such as the primary mirror segments. Design guidance obtained from these simulations is provided to the Telescope, Enclosure, Facilities and Adaptive Optics groups. Computational advances allow for model enhancements and inclusion of phenomena not previously resolved, such as transient effects on wind loading and thermal seeing due to vent operation while observing or long exposure effects, with potentially different flow patterns corresponding to the beginning and end of observation. Accurate knowledge of the Observatory aero-thermal environment will result in developing reliable look-up tables for effective open loop correction of key active optics system elements, and cost efficient operation of the Observatory.

  19. Transient calorimetric diagnostics for plasma processing

    NASA Astrophysics Data System (ADS)

    Bornholdt, Sven; Kersten, Holger

    2013-08-01

    This paper reports on an improvement of the calorimetric method for the determination of energy fluxes from plasma towards substrates by using a transient technique. It provides a short overview of the traditional method used for characterization of plasma-wall-interactions during plasma processing. The mathematical framework of the method and possible implications are discussed. It is shown how the method can be improved to obtain additional and detailed information about the energy influx in a shorter measurement time. For this purpose, the probe bias (if applied), which has commonly been kept constant is varied like in Langmuir probe measurements. The experimental validation of the theoretical considerations emphasizes the potential of the method for control in plasma processing. The possibility how the passive calorimetric probe can be used in continuous measurements for process monitoring without any feedback loops used by other probes, is finally discussed.

  20. Program for the Analysis of Reactor Transients

    2002-01-29

    This program is designed for use in predicting the course of and consequence of nondestructive accidents in research and test reactor cores. It is intended primarily for the analysis of plate type research and test reactors and has been subjected to extensive comparisons with the SPERT I and SPERT II experiments. These comparisons were quite favorable for a wide range of transients up to and including melting of the clad. Favorable comparisons have also beenmore » made for TRIGA reactor pulses in pin geometry. The PARET/ANL code has been used by the RERTR (Reduced Enrichment Research and Test Reactor) Program for the safety evaluation of many of the candidate reactors for reduced enrichment.« less

  1. LONG GAMMA-RAY TRANSIENTS FROM COLLAPSARS

    SciTech Connect

    Woosley, S. E.; Heger, Alexander E-mail: alex@physics.umn.edu

    2012-06-10

    In the collapsar model for common gamma-ray bursts (GRBs), the formation of a centrifugally supported disk occurs during the first {approx}10 s following the collapse of the iron core in a massive star. This only occurs in a small fraction of massive stellar deaths, however, and requires unusual conditions. A much more frequent occurrence could be the death of a star that makes a black hole and a weak or absent outgoing shock, but in a progenitor that only has enough angular momentum in its outermost layers to make a disk. We consider several cases where this is likely to occur-blue supergiants with low mass-loss rates, tidally interacting binaries involving either helium stars or giant stars, and the collapse to a black hole of very massive pair-instability supernovae. These events have in common the accretion of a solar mass or so of material through a disk over a period much longer than the duration of a common GRB. A broad range of powers is possible, 10{sup 47}-10{sup 50} erg s{sup -1}, and this brightness could be enhanced by beaming. Such events were probably more frequent in the early universe where mass-loss rates were lower. Indeed, this could be one of the most common forms of gamma-ray transients in the universe and could be used to study first generation stars. Several events could be active in the sky at any one time. Recent examples of this sort of event may have been the Swift transients Sw-1644+57, Sw-2058+0516, and GRB 101225A.

  2. Impaired picture recognition in transient epileptic amnesia.

    PubMed

    Dewar, Michaela; Hoefeijzers, Serge; Zeman, Adam; Butler, Christopher; Della Sala, Sergio

    2015-01-01

    Transient epileptic amnesia (TEA) is an epileptic syndrome characterized by recurrent, brief episodes of amnesia. Transient epileptic amnesia is often associated with the rapid decline in recall of new information over hours to days (accelerated long-term forgetting - 'ALF'). It remains unknown how recognition memory is affected in TEA over time. Here, we report a systematic study of picture recognition in patients with TEA over the course of one week. Sixteen patients with TEA and 16 matched controls were presented with 300 photos of everyday life scenes. Yes/no picture recognition was tested 5min, 2.5h, 7.5h, 24h, and 1week after picture presentation using a subset of target pictures as well as similar and different foils. Picture recognition was impaired in the patient group at all test times, including the 5-minute test, but it declined normally over the course of 1week. This impairment was associated predominantly with an increased false alarm rate, especially for similar foils. High performance on a control test indicates that this impairment was not associated with perceptual or discrimination deficits. Our findings suggest that, at least in some TEA patients with ALF in verbal recall, picture recognition does not decline more rapidly than in controls over 1week. However, our findings of an early picture recognition deficit suggest that new visual memories are impoverished after minutes in TEA. This could be the result of deficient encoding or impaired early consolidation. The early picture recognition deficit observed could reflect either the early stages of the process that leads to ALF or a separable deficit of anterograde memory in TEA. Lastly, our study suggests that at least some patients with TEA are prone to falsely recognizing new everyday visual information that they have not in fact seen previously. This deficit, alongside their ALF in free recall, likely affects everyday memory performance.

  3. Harnessing quantum transport by transient chaos.

    PubMed

    Yang, Rui; Huang, Liang; Lai, Ying-Cheng; Grebogi, Celso; Pecora, Louis M

    2013-03-01

    Chaos has long been recognized to be generally advantageous from the perspective of control. In particular, the infinite number of unstable periodic orbits embedded in a chaotic set and the intrinsically sensitive dependence on initial conditions imply that a chaotic system can be controlled to a desirable state by using small perturbations. Investigation of chaos control, however, was largely limited to nonlinear dynamical systems in the classical realm. In this paper, we show that chaos may be used to modulate or harness quantum mechanical systems. To be concrete, we focus on quantum transport through nanostructures, a problem of considerable interest in nanoscience, where a key feature is conductance fluctuations. We articulate and demonstrate that chaos, more specifically transient chaos, can be effective in modulating the conductance-fluctuation patterns. Experimentally, this can be achieved by applying an external gate voltage in a device of suitable geometry to generate classically inaccessible potential barriers. Adjusting the gate voltage allows the characteristics of the dynamical invariant set responsible for transient chaos to be varied in a desirable manner which, in turn, can induce continuous changes in the statistical characteristics of the quantum conductance-fluctuation pattern. To understand the physical mechanism of our scheme, we develop a theory based on analyzing the spectrum of the generalized non-Hermitian Hamiltonian that includes the effect of leads, or electronic waveguides, as self-energy terms. As the escape rate of the underlying non-attracting chaotic set is increased, the imaginary part of the complex eigenenergy becomes increasingly large so that pointer states are more difficult to form, making smoother the conductance-fluctuation pattern.

  4. Arecibo Pulsar and Transient Surveys Using ALFA

    NASA Astrophysics Data System (ADS)

    Cordes, J. M.

    2008-02-01

    A large scale survey for pulsars and transients is being conducted at the Arecibo Observatory using the Arecibo L-band Feed Array (ALFA). Data acquisition so far has been with correlation spectrometers that analyze a 0.1 GHz bandwidth at 1.4 GHz. The 256 frequency channels limit dispersion smearing to 1.2 ms at DMmax = 103 pc cm-3 while the sampling interval of 64 μs equals the dispersion smearing at DM~54 pc cm-3, providing high sensitivity to millisecond pulsars with standard periods out to implied distances of several kpc at low Galactic latitudes. In early 2008, we will use a new set of polyphase filter bank systems that provide the same time and frequency resolutions but over ALFA's full 0.3 GHz bandwidth. Currently the survey covers sky positions within 5° of the Galactic plane that are reachable with Arecibo. Preliminary results are given for some of the discoveries made so far, which include millisecond pulsars, a relativistic binary pulsar, a likely counterpart of a Compton GRO/EGRET gamma-ray source, and transient pulsars (including `RRATs''). We discuss the methodology of the survey, which includes archival of raw survey data at the Cornell Center for Advanced Computing and processing at distributed sites. The survey and follow up observations, which include timing observations, multiwavelength searches for orbital companions in the case of binary pulsars, etc. are organized through the Pulsar-ALFA (PALFA) Consortium. We expect the Galactic plane survey to continue until at least 2010, most likely involving multiple passes on each sky position to optimize detection of variable sources. The ALFA system will also be used to survey intermediate Galactic latitudes for millisecond pulsars, relativistic binaries with large systemic velocities, and runaway pulsars that will escape the Galaxy.

  5. Impaired picture recognition in transient epileptic amnesia.

    PubMed

    Dewar, Michaela; Hoefeijzers, Serge; Zeman, Adam; Butler, Christopher; Della Sala, Sergio

    2015-01-01

    Transient epileptic amnesia (TEA) is an epileptic syndrome characterized by recurrent, brief episodes of amnesia. Transient epileptic amnesia is often associated with the rapid decline in recall of new information over hours to days (accelerated long-term forgetting - 'ALF'). It remains unknown how recognition memory is affected in TEA over time. Here, we report a systematic study of picture recognition in patients with TEA over the course of one week. Sixteen patients with TEA and 16 matched controls were presented with 300 photos of everyday life scenes. Yes/no picture recognition was tested 5min, 2.5h, 7.5h, 24h, and 1week after picture presentation using a subset of target pictures as well as similar and different foils. Picture recognition was impaired in the patient group at all test times, including the 5-minute test, but it declined normally over the course of 1week. This impairment was associated predominantly with an increased false alarm rate, especially for similar foils. High performance on a control test indicates that this impairment was not associated with perceptual or discrimination deficits. Our findings suggest that, at least in some TEA patients with ALF in verbal recall, picture recognition does not decline more rapidly than in controls over 1week. However, our findings of an early picture recognition deficit suggest that new visual memories are impoverished after minutes in TEA. This could be the result of deficient encoding or impaired early consolidation. The early picture recognition deficit observed could reflect either the early stages of the process that leads to ALF or a separable deficit of anterograde memory in TEA. Lastly, our study suggests that at least some patients with TEA are prone to falsely recognizing new everyday visual information that they have not in fact seen previously. This deficit, alongside their ALF in free recall, likely affects everyday memory performance. PMID:25506793

  6. TRANSIENT LUNAR PHENOMENA: REGULARITY AND REALITY

    SciTech Connect

    Crotts, Arlin P. S.

    2009-05-20

    Transient lunar phenomena (TLPs) have been reported for centuries, but their nature is largely unsettled, and even their existence as a coherent phenomenon is controversial. Nonetheless, TLP data show regularities in the observations; a key question is whether this structure is imposed by processes tied to the lunar surface, or by terrestrial atmospheric or human observer effects. I interrogate an extensive catalog of TLPs to gauge how human factors determine the distribution of TLP reports. The sample is grouped according to variables which should produce differing results if determining factors involve humans, and not reflecting phenomena tied to the lunar surface. Features dependent on human factors can then be excluded. Regardless of how the sample is split, the results are similar: {approx}50% of reports originate from near Aristarchus, {approx}16% from Plato, {approx}6% from recent, major impacts (Copernicus, Kepler, Tycho, and Aristarchus), plus several at Grimaldi. Mare Crisium produces a robust signal in some cases (however, Crisium is too large for a 'feature' as defined). TLP count consistency for these features indicates that {approx}80% of these may be real. Some commonly reported sites disappear from the robust averages, including Alphonsus, Ross D, and Gassendi. These reports begin almost exclusively after 1955, when TLPs became widely known and many more (and inexperienced) observers searched for TLPs. In a companion paper, we compare the spatial distribution of robust TLP sites to transient outgassing (seen by Apollo and Lunar Prospector instruments). To a high confidence, robust TLP sites and those of lunar outgassing correlate strongly, further arguing for the reality of TLPs.

  7. Rapidly Rising Transients from the Subaru Hyper Suprime-Cam Transient Survey

    NASA Astrophysics Data System (ADS)

    Tanaka, Masaomi; Tominaga, Nozomu; Morokuma, Tomoki; Yasuda, Naoki; Furusawa, Hisanori; Baklanov, Petr V.; Blinnikov, Sergei I.; Moriya, Takashi J.; Doi, Mamoru; Jiang, Ji-an; Kato, Takahiro; Kikuchi, Yuki; Kuncarayakti, Hanindyo; Nagao, Tohru; Nomoto, Ken'ichi; Taniguchi, Yuki

    2016-03-01

    We present rapidly rising transients discovered by a high-cadence transient survey with the Subaru telescope and Hyper Suprime-Cam. We discovered five transients at z = 0.384-0.821, showing a rate of rise faster than 1 mag per day in the restframe near-ultraviolet wavelengths. The fast rate of rise and brightness are most similar to SN 2010aq and PS1-13arp, for which ultraviolet emission was detected within a few days after the shock breakout. The lower limit of the event rate of rapidly rising transients is ˜9% of core-collapse supernova rates, assuming the duration of rapid rise to be 1 day. We show that the light curves of the three faint objects agree with the cooling envelope emission from the explosion of red supergiants. The other two luminous objects, however, are brighter and faster than the cooling envelope emission. We interpret these two objects to be the shock breakout from a dense wind with a mass loss rate of ˜10-3 {M}⊙ yr-1, as also proposed for PS1-13arp. This mass loss rate is higher than that typically observed for red supergiants. The event rate of these luminous objects is ≳1% of the core-collapse supernova rate, and thus our study implies that more than ˜1% of massive stars can experience intense mass loss a few years before the explosion. Based (in part) on data collected at Subaru Telescope, which is operated by the National Astronomical Observatory of Japan.

  8. Multiscale Transient Signal Detection: Localizing Transients in Geodetic Data Through Wavelet Transforms and Sparse Estimation Techniques

    NASA Astrophysics Data System (ADS)

    Riel, B.; Simons, M.; Agram, P.

    2012-12-01

    Transients are a class of deformation signals on the Earth's surface that can be described as non-periodic accumulation of strain in the crust. Over seismically and volcanically active regions, these signals are often challenging to detect due to noise and other modes of deformation. Geodetic datasets that provide precise measurements of surface displacement over wide areas are ideal for exploiting both the spatial and temporal coherence of transient signals. We present an extension to the Multiscale InSAR Time Series (MInTS) approach for analyzing geodetic data by combining the localization benefits of wavelet transforms (localizing signals in space) with sparse optimization techniques (localizing signals in time). Our time parameterization approach allows us to reduce geodetic time series to sparse, compressible signals with very few non-zero coefficients corresponding to transient events. We first demonstrate the temporal transient detection by analyzing GPS data over the Long Valley caldera in California and along the San Andreas fault near Parkfield, CA. For Long Valley, we are able to resolve the documented 2002-2003 uplift event with greater temporal precision. Similarly for Parkfield, we model the postseismic deformation by specific integrated basis splines characterized by timescales that are largely consistent with postseismic relaxation times. We then apply our method to ERS and Envisat InSAR datasets consisting of over 200 interferograms for Long Valley and over 100 interferograms for Parkfield. The wavelet transforms reduce the impact of spatially correlated atmospheric noise common in InSAR data since the wavelet coefficients themselves are essentially uncorrelated. The spatial density and extended temporal coverage of the InSAR data allows us to effectively localize ground deformation events in both space and time with greater precision than has been previously accomplished.

  9. Follow-up/light-curves of transients from the Catalina Realtime Transient Survey

    NASA Astrophysics Data System (ADS)

    Mahabal, Ashish; Drake, Andrew; Djorgovski, S. G.; Christiansen, Eric

    2011-08-01

    We propose to obtain multicolor light curves of interesting optical transients (OTs) discovered in the Catalina Realtime Transient Survey (CRTS). CRTS discovers OTs by obtaining repeated unfiltered CCD images of the same part of the sky. We have so far found ~ 3300 OTs including SNe, CV, blazars, AGN and many rarer classes. While a monochromatic survey can detect transients, their physical classification, interpretation and prioritization for a further follow- up - and thus the net scientific returns from the survey - depend crucially on the light curve and color information. We would obtain such information for objects which defy an immediate classification, or where such information would provide useful astrophysical information on its own (e.g., SN light curves). The most interesting events may then be followed up spectroscopically. Discovery of the rare, unusual, or even previously unknown types of OTs is one of the key priorities. These measurements will help us sharpen strategies for the future OT follow-up work, as well as to develop and improve the novel machine learning tools for automated classification of OTs, an essential enabling technology for the present and future synoptic surveys, including the LSST. In order to maximize the scientific returns for the entire community, we will be making all data immediately public (as we have started doing for the 2011A term).

  10. Static and Transient Cavitation Threshold Measurements for Mercury

    SciTech Connect

    Moraga, F.; Taleyarkhan, R.P.

    1999-11-14

    Transient and static cavitation thresholds for mercury as a function of the cover gas (helium or air), and pressure are reported. Both static and transient cavitation onset pressure thresholds increase linearly with cover gas pressure. Additionally, the cavitation thresholds as a function of dissolved gases were also measured and are reported.

  11. 47 CFR 90.214 - Transient frequency behavior.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Transient frequency behavior. 90.214 Section 90... PRIVATE LAND MOBILE RADIO SERVICES General Technical Standards § 90.214 Transient frequency behavior. Transmitters designed to operate in the 150-174 MHz and 421-512 MHz frequency bands must maintain...

  12. 47 CFR 90.214 - Transient frequency behavior.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Transient frequency behavior. 90.214 Section 90... PRIVATE LAND MOBILE RADIO SERVICES General Technical Standards § 90.214 Transient frequency behavior. Transmitters designed to operate in the 150-174 MHz and 421-512 MHz frequency bands must maintain...

  13. 17 CFR 270.3a-2 - Transient investment companies.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 17 Commodity and Securities Exchanges 4 2014-04-01 2014-04-01 false Transient investment companies. 270.3a-2 Section 270.3a-2 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION (CONTINUED) RULES AND REGULATIONS, INVESTMENT COMPANY ACT OF 1940 § 270.3a-2 Transient investment...

  14. 17 CFR 270.3a-2 - Transient investment companies.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 17 Commodity and Securities Exchanges 3 2012-04-01 2012-04-01 false Transient investment companies. 270.3a-2 Section 270.3a-2 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION (CONTINUED) RULES AND REGULATIONS, INVESTMENT COMPANY ACT OF 1940 § 270.3a-2 Transient investment...

  15. 47 CFR 90.214 - Transient frequency behavior.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Transient frequency behavior. 90.214 Section 90... PRIVATE LAND MOBILE RADIO SERVICES General Technical Standards § 90.214 Transient frequency behavior. Transmitters designed to operate in the 150-174 MHz and 421-512 MHz frequency bands must maintain...

  16. 17 CFR 270.3a-2 - Transient investment companies.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 17 Commodity and Securities Exchanges 3 2011-04-01 2011-04-01 false Transient investment companies. 270.3a-2 Section 270.3a-2 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION (CONTINUED) RULES AND REGULATIONS, INVESTMENT COMPANY ACT OF 1940 § 270.3a-2 Transient investment...

  17. 47 CFR 90.214 - Transient frequency behavior.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Transient frequency behavior. 90.214 Section 90... PRIVATE LAND MOBILE RADIO SERVICES General Technical Standards § 90.214 Transient frequency behavior. Transmitters designed to operate in the 150-174 MHz and 421-512 MHz frequency bands must maintain...

  18. 17 CFR 270.3a-2 - Transient investment companies.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 17 Commodity and Securities Exchanges 3 2013-04-01 2013-04-01 false Transient investment companies. 270.3a-2 Section 270.3a-2 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION (CONTINUED) RULES AND REGULATIONS, INVESTMENT COMPANY ACT OF 1940 § 270.3a-2 Transient investment...

  19. 47 CFR 90.214 - Transient frequency behavior.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Transient frequency behavior. 90.214 Section 90... PRIVATE LAND MOBILE RADIO SERVICES General Technical Standards § 90.214 Transient frequency behavior. Transmitters designed to operate in the 150-174 MHz and 421-512 MHz frequency bands must maintain...

  20. [THERAPY OF TRANSIENT LACTASE INSUFFICIENCY OF CHILDREN IN PECTORAL AGE].

    PubMed

    Marushko, Yu V; Iovitsa, T V

    2015-01-01

    Thus, we have discovered that the children of the first half-year of life have different degrees of severity of transient lactase insufficiency basing on the results of hydrogen respiratory test. It was set that the starting dose of enzyme lactase must depend on the degree of severity of displays of transient lactase insufficiency, taking into account the indexes of hydrogen respiratory test.

  1. Spectroscopic Classifications of Optical Transients with SOAR/Goodman

    NASA Astrophysics Data System (ADS)

    Miller, J. A.; Hounsell, R. A.; Pan, Y.-C.; Kilpatrick, C. D.; Foley, R. J.; Jha, S. W.; Rest, A.; Scolnic, D.

    2016-08-01

    We report a classification of optical transients from spectroscopic observations with the Goodman spectrograph on the SOAR telescope. Targets were supplied by the All-Sky Automated Survey for Supernovae (ASAS-SN) and the Pan-STARRS Survey for Transients (PSST).

  2. Spectroscopic Classifications of Optical Transients with Mayall/KOSMOS

    NASA Astrophysics Data System (ADS)

    Pan, Y.-C.; Foley, R. J.; Jha, S. W.; Rest, A.; Scolnic, D.

    2016-06-01

    We report the following classifications of optical transients from spectroscopic observations with KOSMOS on the KPNO Mayall 4-m telescope. Targets were supplied by the Pan-STARRS Survey for Transients (PSST), All-Sky Automated Survey for Supernovae (ASAS-SN) and MASTER.

  3. Spectroscopic Classifications of Optical Transients with Mayall/KOSMOS

    NASA Astrophysics Data System (ADS)

    Pan, Y.-C.; Kilpatrick, C. D.; Siebert, M. R.; Foley, R. J.; Jha, S. W.; Rest, A.; Scolnic, D.

    2016-08-01

    We report the following classifications of optical transients from spectroscopic observations with KOSMOS on the KPNO Mayall 4-m telescope. Targets were supplied by the Pan-STARRS Survey for Transients (PSST) and the All-Sky Automated Survey for Supernovae (ASAS-SN).

  4. 17 CFR 270.3a-2 - Transient investment companies.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Transient investment companies... (CONTINUED) RULES AND REGULATIONS, INVESTMENT COMPANY ACT OF 1940 § 270.3a-2 Transient investment companies... which an issuer owns or proposes to acquire investment securities (as defined in section 3(a) of the...

  5. Transient flow thrust prediction for an ejector propulsion concept

    NASA Technical Reports Server (NTRS)

    Drummond, Colin K.

    1989-01-01

    A method for predicting transient thrust augmenting ejector characteristics is introduced. The analysis blends classic self-similar turbulent jet descriptions with a mixing region control volume analysis to predict transient effects in a new way. Details of the theoretical foundation, the solution algorithm, and sample calculations are given.

  6. Network Connectivity for Permanent, Transient, Independent, and Correlated Faults

    NASA Technical Reports Server (NTRS)

    White, Allan L.; Sicher, Courtney; henry, Courtney

    2012-01-01

    This paper develops a method for the quantitative analysis of network connectivity in the presence of both permanent and transient faults. Even though transient noise is considered a common occurrence in networks, a survey of the literature reveals an emphasis on permanent faults. Transient faults introduce a time element into the analysis of network reliability. With permanent faults it is sufficient to consider the faults that have accumulated by the end of the operating period. With transient faults the arrival and recovery time must be included. The number and location of faults in the system is a dynamic variable. Transient faults also introduce system recovery into the analysis. The goal is the quantitative assessment of network connectivity in the presence of both permanent and transient faults. The approach is to construct a global model that includes all classes of faults: permanent, transient, independent, and correlated. A theorem is derived about this model that give distributions for (1) the number of fault occurrences, (2) the type of fault occurrence, (3) the time of the fault occurrences, and (4) the location of the fault occurrence. These results are applied to compare and contrast the connectivity of different network architectures in the presence of permanent, transient, independent, and correlated faults. The examples below use a Monte Carlo simulation, but the theorem mentioned above could be used to guide fault-injections in a laboratory.

  7. Transient platoon aerodynamics and bluff body flows

    NASA Astrophysics Data System (ADS)

    Tsuei, Lun

    There are two components of this experimental work: transient vehicle platoon aerodynamics and bluff-body flows. The transient aerodynamic effects in a four-vehicle platoon during passing maneuvers and in-line oscillations are investigated. A vehicle model is moved longitudinally parallel to a four-car platoon to simulate passing maneuvers. The drag and side forces experienced by each platoon member are measured using strain gauge balances. The resulting data are presented as dimensionless coefficients. It is shown that each car in the platoon experiences a repulsive side force when the passing vehicle is in the neighborhood of its rear half. The side force reverses its direction and becomes an attractive force when the passing vehicle moves to the neighborhood of its front half. The drag force experienced by each platoon member is increased when the passing vehicle is in its proximity. The effects of the lateral spacing and relative velocity between the platoon and the passing vehicle, as well as the shape of the passing vehicle, are also investigated. Similar trends are observed in simulations of both a vehicle passing a platoon and a platoon overtaking a vehicle. During the in-line oscillation experiments, one of the four platoon members is forced to undergo longitudinal periodic motions. The drag force experienced by each platoon member is determined simultaneously during the oscillations. The effects of the location of the oscillating vehicle, the shape of the vehicles and the displacement and velocity amplitudes of the oscillation are examined. The results from the transient conditions are compared to those from the steady tests in the same setup. In the case of a four-car platoon, the drag variations experienced by the vehicles adjacent to the oscillating vehicle are discussed using a cavity model. It is found that when the oscillating car moves forward and approaches its upstream neighbor, itself and its downstream neighbor experiences an increased drag

  8. Time of flight transients in the dipolar glass model

    NASA Astrophysics Data System (ADS)

    Novikov, S. V.; Tyutnev, A. P.; Schein, L. B.

    2012-07-01

    Using Monte Carlo simulation we investigated time of flight current transients predicted by the dipolar glass model for a random spatial distribution of hopping centers. Behavior of the carrier drift mobility was studied at room temperature over a broad range of electric field and sample thickness. A flat plateau followed by j∝t-2 current decay is the most common feature of the simulated transients. Poole-Frenkel mobility field dependence was confirmed over 5-200 V/μm as well as its independence of the sample thickness. Universality of transients with respect to both field and sample thickness has been observed. A simple phenomenological model to describe simulated current transients has been proposed. Simulation results agree well with the reported Poole-Frenkel slope and shape of the transients for a prototype molecularly doped polymer.

  9. Swift/BAT and MAXI/GSC broadband transient monitor

    NASA Astrophysics Data System (ADS)

    Sakamoto, Takanori; Oda, Ryoma; Mihara, Tatehiro; Yoshida, Atsumasa; Arimoto, Makoto; Barthelmy, Scott D.; Kawai, Nobuyuki; Krimm, Hans A.; Nakahira, Satoshi; Serino, Motoko

    2016-06-01

    We present a newly developed broadband transient monitor using the Swift Burst Alert Telescope (BAT) and the MAXI Gas Slit Camera (GSC) data. Our broadband transient monitor keeps vigil for high-energy transient sources from 2 keV to 200 keV in seven energy bands by combining the BAT (15-200 keV) and the GSC (2-20 keV) data. Currently, daily and 90-minute (one orbit) averaged light curves are available for 106 high-energy transient sources. This transient monitor is available to the public through our web server, http://yoshidalab.mydns.jp/bat_gsc_trans_mon/, for wider use by the community. We discuss a daily sensitivity of our monitor and possible future improvements on our pipeline.

  10. Analysis of DC offset Influence on Transient Signal

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Lin, J.; Zhou, G. H.

    2006-10-01

    Based on the characteristic of transient signal and the principle of floating-point data acquisition circuit, the influences of DC offset on transient signal are analyzed. And the conclusion can be obtained that the singularity and saturation distortions in transient signals can be produced by DC offset through the detailed principle analysis, the limits calculation of DC offset, and waveform simulation while the DC offset is present in floating-point amplifier circuit of floating-point data acquisition circuit. At the same time, the distributions of distortions in those conditions that the single and several theoretic transient signals and also in actual measured transient signal are compared and discussed. Finally, the corresponding solutions are given according to the main factors which produce the waveform distortion. In a word, this research can provide useful references for the adjustment of floating-point receiver and the analysis of waveform distortion.

  11. A New Adaptive Mother Wavelet for Electromagnetic Transient Analysis

    NASA Astrophysics Data System (ADS)

    Guillén, Daniel; Idárraga-Ospina, Gina; Cortes, Camilo

    2016-01-01

    Wavelet Transform (WT) is a powerful technique of signal processing, its applications in power systems have been increasing to evaluate power system conditions, such as faults, switching transients, power quality issues, among others. Electromagnetic transients in power systems are due to changes in the network configuration, producing non-periodic signals, which have to be identified to avoid power outages in normal operation or transient conditions. In this paper a methodology to develop a new adaptive mother wavelet for electromagnetic transient analysis is proposed. Classification is carried out with an innovative technique based on adaptive wavelets, where filter bank coefficients will be adapted until a discriminant criterion is optimized. Then, its corresponding filter coefficients will be used to get the new mother wavelet, named wavelet ET, which allowed to identify and to distinguish the high frequency information produced by different electromagnetic transients.

  12. Community assembly: alternative stable states or alternative transient states?

    PubMed Central

    Fukami, Tadashi; Nakajima, Mifuyu

    2011-01-01

    The concept of alternative stable states has long been a dominant framework for studying the influence of historical contingency in community assembly. This concept focuses on stable states, yet many real communities are kept in a transient state by disturbance, and the utility of predictions for stable states in explaining transient states remains unclear. Using a simple model of plant community assembly, we show that the conditions under which historical contingency affects community assembly can differ greatly for stable versus transient states. Differences arise because the contribution of such factors as mortality rate, environmental heterogeneity and plant-soil feedback to historical contingency changes as community assembly proceeds. We also show that transient states can last for a long time relative to immigration rate and generation time. These results argue for a conceptual shift of focus from alternative stable states to alternative transient states for understanding historical contingency in community assembly. PMID:21790934

  13. Interface Evolution During Transient Pressure Solution Creep

    NASA Astrophysics Data System (ADS)

    Dysthe, D. K.; Podladchikov, Y. Y.; Renard, F.; Jamtveit, B.; Feder, J.

    When aggregates of small grains are pressed together in the presence of small amounts of solvent the aggregate compacts and the grains tend to stick together. This hap- pens to salt and sugar in humid air, and to sediments when buried in the Earths crust. Stress concentration at the grain contacts cause local dissolution, diffusion of the dissolved material out of the interface and deposition on the less stressed faces of the grains{1}. This process, in geology known as pressure solution, plays a cen- tral role during compaction of sedimentary basins{1,2}, during tectonic deformation of the Earth's crust{3}, and in strengthening of active fault gouges following earth- quakes{4,5}. Experimental data on pressure solution has so far not been sufficiently accurate to understand the transient processes at the grain scale. Here we present ex- perimental evidence that pressure solution creep does not establish a steady state inter- face microstructure as previously thought. Conversely, cumulative creep strain and the characteristic size of interface microstructures grow as the cubic root of time. A sim- ilar transient phenomenon is known in metallurgy (Andrade creep) and is explained here using an analogy with spinodal dewetting. 1 Weyl, P. K., Pressure solution and the force of crystallization - a phenomenological theory. J. Geophys. Res., 64, 2001-2025 (1959). 2 Heald, M. T., Cementation of Simpson and St. Peter Sandstones in parts of Okla- homa, Arkansas and Missouri, J. Geol. Chicago, 14, 16-30 (1956). 3 Schwartz, S., Stöckert, B., Pressure solution in siliciclastic HP-LT metamorphic rocks constraints on the state of stress in deep levels of accretionary complexes. Tectonophysics, 255, 203-209 (1996). 4 Renard, F., Gratier, J.P., Jamtveit, B., Kinetics of crack-sealing, intergranular pres- sure solution, and compaction around active faults. J. Struct. Geol., 22, 1395-1407, (2000). 5 Miller, S. A., BenZion, Y., Burg, J. P.,A three-dimensional fluid-controlled earth

  14. What Oceanographers are Learning From Transient Tracers

    NASA Astrophysics Data System (ADS)

    Jenkins, W. J.

    2002-12-01

    A number of substances have been released into the environment on a global scale from humankind's activities. Observation of the passage of these tracers into and through the oceans is providing us with a remarkable opportunity to examine the rates, pathways, and mechanics by which material fluxes occur. Such information is critical to our understanding of how the ocean participates in the grand biogeochemical cycles, the earth system, and long-term climate regulation. This understanding is important for forecasting and possibly ameliorating natural and anthropogenic global change. How we extract this information from the evolving distributions of transient tracers is in itself an unfolding story. In general, there are three basic but related approaches that are used. The first involves "pathway visualization" whereby the observed distributions highlight the routes whereby these tracers propagate into the ocean interior. Observations from the WOCE and other programs provide us with compelling pictures of transient tracer distributions never before seen. This visualization provides geographic information about where the tracers have reached, and within some broad time-scale. A second approach involves the diagnosis of various transport properties directly from the observed fields, whether by regression calculations, inversions, or Green function estimates. Such calculations often lead to some estimate of the flow field, such as advection or turbulent mixing rates; or to a measure of inherent biogeochemical reactivity, such as adsorption, consumption, or particulate transport. A related approach involves the direct calculation of "tracer ages", which provide some measure of the ventilation time-scale of the water masses. Such a calculation, however, has subtle issues associated with it. Finally, comparison of observed tracer fields with prognostic model calculations has been used for evaluation and intercomparison of model performance. So what are we learning from

  15. Transient High-Pressure Fuel Injection

    NASA Astrophysics Data System (ADS)

    Jarrahbashi, Dorrin

    Break-up and atomization of liquid fuel jet during transient injection process has a significant effect on the Diesel engine combustion efficiency and pollution. The mechanisms responsible for liquid jet instability and break-up at high pressure, during the transient start-up and steady mass flux periods, has been investigated using Navier-Stokes and level-set computations. Via post-processing, the role of vorticity dynamics is examined and shown to reveal crucial new insights. An unsteady, axisymmetric full-jet case is solved. Then, a less computationally intensive case is studied with a segment of the jet core undergoing temporal instability; agreement with the full-jet calculation is satisfactory justifying the segment analysis for three-dimensional computation. The results for surface-shape development are in agreement with experimental observations and other three-dimensional computations; the initial, axisymmetric waves at the jet surface created by Kelvin-Helmholtz instability distort to cone shapes; next, three-dimensional character develops through an azimuthal instability that leads to the creation of streamwise vorticity, lobe shapes on the cones, and formation of liquid ligaments which extend from lobes on the cones. The cause of this azimuthal instability has been widely described as a Rayleigh-Taylor instability. However, additional and sometimes more important causes are identified here. Counter-rotating, streamwise vortices within and around the ligaments show a relationship in the instability behavior for jets flowing into like-density fluid; thus, density difference cannot explain fully the three-dimensional instability as previously suggested. Furthermore, the formation of ligaments that eventually break into droplets and the formation of streamwise vorticity are caused by the same vortical dynamics. Waviness is identified on the ligaments which should result in droplet formation. The nonlinear development of the shorter azimuthal waves and

  16. Transient aphasias after left hemisphere resective surgery

    PubMed Central

    Wilson, Stephen M.; Lam, Daniel; Babiak, Miranda; Perry, David; Shih, Tina; Hess, Christopher P.; Berger, Mitchel S.; Chang, Edward F.

    2015-01-01

    Object Transient aphasias are often observed in the first few days in patients who undergo surgical resection in the language-dominant hemisphere. The aims of this prospective study were to characterize the incidence and nature of these aphasias, and to determine whether there are relationships between location of the surgical site and deficits in specific language domains. Methods 110 patients undergoing resection to the language-dominant hemisphere participated in the study. Patients’ language was evaluated prior to surgery, 2-3 days post-surgery, and 1 month post-surgery using the Western Aphasia Battery and the Boston Naming Test. Voxel-based lesion-symptom mapping was used to identify relationships between the location of the surgical site assessed by MRI, and deficits in fluency, information content, comprehension, repetition, and naming. Results 71% of patients were classified as aphasic based on the Western Aphasia Battery 2-3 days post-surgery, with deficits observed in each of the language domains examined. Fluency deficits were associated with resection of the precentral gyrus and adjacent inferior frontal cortex. Reduced information content of spoken output was associated with resection of the ventral precentral gyrus and posterior inferior frontal gyrus (pars opercularis). Repetition deficits were associated with resection of the posterior superior temporal gyrus. Naming deficits were associated with resection of ventral temporal cortex, with mid temporal and posterior temporal damage more predictive of naming deficits than anterior temporal damage. By 1 month post-surgery, nearly all language deficits were resolved, and no language measure except for naming differed significantly from pre-surgical levels. Conclusions These findings show that transient aphasias are very common after left hemisphere resective surgery, and that the precise nature of the aphasia depends on the specific location of the surgical site. This patient cohort provides a unique

  17. Transient Point Infiltration In The Unsaturated Zone

    NASA Astrophysics Data System (ADS)

    Buecker-Gittel, M.; Mohrlok, U.

    The risk assessment of leaking sewer pipes gets more and more important due to urban groundwater management and environmental as well as health safety. This requires the quantification and balancing of transport and transformation processes based on the water flow in the unsaturated zone. The water flow from a single sewer leakage could be described as a point infiltration with time varying hydraulic conditions externally and internally. External variations are caused by the discharge in the sewer pipe as well as the state of the leakage itself. Internal variations are the results of microbiological clogging effects associated with the transformation processes. Technical as well as small scale laboratory experiments were conducted in order to investigate the water transport from an transient point infiltration. From the technical scale experiment there was evidence that the water flow takes place under transient conditions when sewage infiltrates into an unsaturated soil. Whereas the small scale experiments investigated the hydraulics of the water transport and the associated so- lute and particle transport in unsaturated soils in detail. The small scale experiment was a two-dimensional representation of such a point infiltration source where the distributed water transport could be measured by several tensiometers in the soil as well as by a selective measurement of the discharge at the bottom of the experimental setup. Several series of experiments were conducted varying the boundary and initial con- ditions in order to derive the important parameters controlling the infiltration of pure water from the point source. The results showed that there is a significant difference between the infiltration rate in the point source and the discharge rate at the bottom, that could be explained by storage processes due to an outflow resistance at the bottom. This effect is overlayn by a decreasing water content decreases over time correlated with a decreasing infiltration

  18. Simulation Prediction of Transient Dropwise Condensation

    NASA Astrophysics Data System (ADS)

    Macner, Ashley; Daniel, Susan; Steen, Paul

    2014-11-01

    In order to design effective surfaces for large-scale dropwise condensation, an understanding of how surface functionalization affects drop growth and coalescence is needed. The long term technological goal is a set of design conditions to help NASA achieve maximum heat transfer rates of waste heat generated from electronics and habitable environments under microgravity conditions. Prediction of condenser surface heat transfer performance requires accurate simulation and modeling of the evolution of populations of drops in time. At shorter times, drops are primarily isolated and grow mainly by condensation onto the liquid-gas interface. At longer times, drops grow mainly by coalescence with neighbors. Simulation of dropwise condensation on a neutrally wetting surface and comparison with our previous experimental results is reported. A steady-state single drop conduction model is empirically fitted to determine a temperature profile that captures the drop size evolution. The simulation accurately predicts the continuous time evolution of number-density of drops, drop-size distributions, total condensate volume, fractional coverage, and median drop-size for both transient and steady states, all with no free parameters. This work was supported by a NASA Office of the Chief Technologist's Space Technology Research Fellowship.

  19. Development of a transient internal probe diagnostic

    NASA Astrophysics Data System (ADS)

    Spanjers, G. G.; Galambos, J. P.; Bohnet, M. A.; Jarboe, T. R.; Christiansen, W. H.; Wurden, G. A.; Wright, B. L.; Smith, R. J.

    1992-10-01

    The transient internal probe (TIP) diagnostic is a novel method for probing the interior of hot magnetic fusion plasmas. In the TIP scheme, a probe is fired, using a two-stage light gas gun, through a hot plasma at velocities up to 5 km/s, and makes direct, local measurements of the internal magnetic field structure. The data are relayed to the laboratory optical detection system using an incident laser that is directed through a Faraday rotator payload acting as a magneto-optic sensor. Ablative effects are avoided by minimizing the probe size, limiting the time that the probe is in the hot plasma, and encasing the probe with a diamond cladding. The degree to which the diamond probe cladding is susceptible to ablative effects will determine the plasma density and temperature regime in which the TIP diagnostic can be used. If the TIP suffers significant ablation it is an indication that the diagnostic is not usable on this hot and dense of a plasma (or that greater velocity must be imparted to the probe to further minimize the time that it is in the plasma). A quantitative experimental study of the ablation rates of diamond is planned as part of the TIP development. The integrated TIP system will be functional in 1992 and installed on the Helicity Injected Torus (HIT) [T. R. Jarboe, Fusion Tech. 15, 9 (1989)] at the University of Washington.

  20. High-energy emission from transients.

    PubMed

    Hinton, J A; Starling, R L C

    2013-06-13

    Cosmic explosions dissipate energy into their surroundings on a very wide range of time scales: producing shock waves and associated particle acceleration. The historical culprits for the acceleration of the bulk of Galactic cosmic rays are supernova remnants: explosions on approximately 10(4) year time scales. Increasingly, however, time-variable emission points to rapid and efficient particle acceleration in a range of different astrophysical systems. Gamma-ray bursts have the shortest time scales, with inferred bulk Lorentz factors of approximately 1000 and photons emitted beyond 100 GeV, but active galaxies, pulsar wind nebulae and colliding stellar winds are all now associated with time-variable emission at approximately teraelectron volt energies. Cosmic photons and neutrinos at these energies offer a powerful probe of the underlying physical mechanisms of cosmic explosions, and a tool for exploring fundamental physics with these systems. Here, we discuss the motivations for high-energy observations of transients, the current experimental situation, and the prospects for the next decade, with particular reference to the major next-generation high-energy observatory, the Cherenkov Telescope Array. PMID:23630380

  1. Viscoelastic Transient of Confined Red Blood Cells

    PubMed Central

    Prado, Gaël; Farutin, Alexander; Misbah, Chaouqi; Bureau, Lionel

    2015-01-01

    The unique ability of a red blood cell to flow through extremely small microcapillaries depends on the viscoelastic properties of its membrane. Here, we study in vitro the response time upon flow startup exhibited by red blood cells confined into microchannels. We show that the characteristic transient time depends on the imposed flow strength, and that such a dependence gives access to both the effective viscosity and the elastic modulus controlling the temporal response of red cells. A simple theoretical analysis of our experimental data, validated by numerical simulations, further allows us to compute an estimate for the two-dimensional membrane viscosity of red blood cells, ηmem2D ∼ 10−7 N⋅s⋅m−1. By comparing our results with those from previous studies, we discuss and clarify the origin of the discrepancies found in the literature regarding the determination of ηmem2D, and reconcile seemingly conflicting conclusions from previous works. PMID:25954871

  2. Transient pulsed radio emission from a magnetar.

    PubMed

    Camilo, Fernando; Ransom, Scott M; Halpern, Jules P; Reynolds, John; Helfand, David J; Zimmerman, Neil; Sarkissian, John

    2006-08-24

    Anomalous X-ray pulsars (AXPs) are slowly rotating neutron stars with very bright and highly variable X-ray emission that are believed to be powered by ultra-strong magnetic fields of >10(14) G, according to the 'magnetar' model. The radio pulsations that have been observed from more than 1,700 neutron stars with weaker magnetic fields have never been detected from any of the dozen known magnetars. The X-ray pulsar XTE J1810-197 was revealed (in 2003) as the first AXP with transient emission when its luminosity increased 100-fold from the quiescent level; a coincident radio source of unknown origin was detected one year later. Here we show that XTE J1810-197 emits bright, narrow, highly linearly polarized radio pulses, observed at every rotation, thereby establishing that magnetars can be radio pulsars. There is no evidence of radio emission before the 2003 X-ray outburst (unlike ordinary pulsars, which emit radio pulses all the time), and the flux varies from day to day. The flux at all radio frequencies is approximately equal--and at >20 GHz XTE J1810-197 is currently the brightest neutron star known. These observations link magnetars to ordinary radio pulsars, rule out alternative accretion models for AXPs, and provide a new window into the coronae of magnetars. PMID:16929292

  3. Analysis of electrical transients created by lightning

    NASA Technical Reports Server (NTRS)

    Nanevicz, J. E.; Vance, E. F.

    1980-01-01

    A series of flight tests was conducted using a specially-instrumented NASA Learjet to study the electrical transients created on an aircraft by nearby lightning. The instrumentation included provisions for the time-domain and frequency-domain recording of the electrical signals induced in sensors located both on the exterior and on the interior of the aircraft. The design and calibration of the sensors and associated measuring systems is described together with the results of the flight test measurements. The results indicate that the concept of providing instrumentation to follow the lightning signal from propagation field, to aircraft skin current, to current on interior wiring is basically sound. The results of the measurement indicate that the high frequency signals associated with lightning stroke precursor activity are important in generating electromagnetic noise on the interior of the aircraft. Indeed, the signals produced by the precursors are often of higher amplitude and of longer duration that the pulse produced by the main return stroke.

  4. Extreme Transients in the High Energy Universe

    NASA Technical Reports Server (NTRS)

    Kouveliotou, Chryssa

    2013-01-01

    The High Energy Universe is rich in diverse populations of objects spanning the entire cosmological (time)scale, from our own present-day Milky Way to the re-ionization epoch. Several of these are associated with extreme conditions irreproducible in laboratories on Earth. Their study thus sheds light on the behavior of matter under extreme conditions, such as super-strong magnetic fields (in excess of 10^14 G), high gravitational potentials (e.g., Super Massive Black Holes), very energetic collimated explosions resulting in relativistic jet flows (e.g., Gamma Ray Bursts, exceeding 10^53 ergs). In the last thirty years, my work has been mostly focused on two apparently different but potentially linked populations of such transients: magnetars (highly magnetized neutron stars) and Gamma Ray Bursts (strongly beamed emission from relativistic jets), two populations that constitute unique astrophysical laboratories, while also giving us the tools to probe matter conditions in the Universe to redshifts beyond z=10, when the first stars and galaxies were assembled. I did not make this journey alone I have either led or participated in several international collaborations studying these phenomena in multi-wavelength observations; solitary perfection is not sufficient anymore in the world of High Energy Astrophysics. I will describe this journey, present crucial observational breakthroughs, discuss key results and muse on the future of this field.

  5. Three years of Transients with Fermi GBM

    NASA Technical Reports Server (NTRS)

    Wilson-Hodge, Colleen A.

    2012-01-01

    The Gamma-ray Burst Monitor (GBM) is an all-sky monitoring instrument, sensitive between 8 keV and 40 MeV, with a primary objective of supporting the Large Area Telescope (LAT) in observations of Gamma-Ray Bursts (GRBs). Both instruments are part of the Fermi Gamma-ray Space Telescope. Together, the GBM and LAT instruments have provided ground-breaking measurements of GRBs that have, after 10 years of focus on GRB afterglows, inspired renewed interest in the prompt emission phase of GRBs and the physical mechanisms that fuel them. In addition to GRB science, GBM has made significant contributions to the astrophysics of galactic transient sources including long-term variations in the Crab nebula, spin state transitions in accretion powered pulsars, state transitions in black hole X-ray binaries, and unprecedented time-resolved spectral studies of soft gamma-ray repeater bursts. Closer to home, GBM also contributes to solar flare and terrestrial gamma flash science.

  6. TEMPEST. Transient 3-D Thermal-Hydraulic

    SciTech Connect

    Eyler, L.L.

    1992-01-31

    TEMPEST is a transient, three-dimensional, hydrothermal program that is designed to analyze a range of coupled fluid dynamic and heat transfer systems of particular interest to the Fast Breeder Reactor (FBR) thermal-hydraulic design community. The full three-dimensional, time-dependent equations of motion, continuity, and heat transport are solved for either laminar or turbulent fluid flow, including heat diffusion and generation in both solid and liquid materials. The equations governing mass, momentum, and energy conservation for incompressible flows and small density variations (Boussinesq approximation) are solved using finite-difference techniques. Analyses may be conducted in either cylindrical or Cartesian coordinate systems. Turbulence is treated using a two-equation model. Two auxiliary plotting programs, SEQUEL and MANPLOT, for use with TEMPEST output are included. SEQUEL may be operated in batch or interactive mode; it generates data required for vector plots, contour plots of scalar quantities, line plots, grid and boundary plots, and time-history plots. MANPLOT reads the SEQUEL-generated data and creates the hardcopy plots. TEMPEST can be a valuable hydrothermal design analysis tool in areas outside the intended FBR thermal-hydraulic design community.

  7. GRB070610: A Curious Galactic Transient

    NASA Technical Reports Server (NTRS)

    Kasliwal, M. M.; Kulkrarni. S. R.; Cameron, P. B.; Nakar, E.; Ofek, E. O.; Rau, A.; Soderberg, A. M.; Campana, S.; Bloom, J. S.; Perley, D. A.; Pollack, L. K.; Barthelmy, S.; Cummings, J.; Gehrels, N.; Krimm, H. A.; Markwardt, C. B.; Sato, G.; Chandra, P.; Frail, D.; Fox, D. B.; Price, P. A.; Berger, E.; Krivonos, R. A.; Grebenev, S. A.; Sunyaev, R. A.

    2007-01-01

    GRB 070610 is a typical high-energy event with a duration of 5s.Yet within the burst localization we detect a highly unusual X-ray and optical transient, SwiftJ195509.6+261406. We see high amplitude X-ray and optical variability on very short time scares even at late times. Using near-infrared imaging assisted by a laser guide star and adaptive optics, we identified the counterpart of SwiftJl95509.6+261406. Late-time optical and near-infrared imaging constrain the spectral type of the counterpart to be fainter than a K-dwarf assuming it is of Galactic origin. It is possible that GRB 070610 and Swift J195509.6+261406 are unrelated sources. However, the absence of a typical X-ray afterglow from GRB 070610 in conjunction with the spatial and temporal coincidence of the two motivate us to suggest that the sources are related. The closest (imperfect) analog to Swift J195509.6+261406 is V4641 Sgr, an unusual black hole binary. We suggest that Swift J195509.6+261406 along with V4641 Sgr define a sub-class of stellar black hole binaries -- the fast X-ray novae. We further suggest that fast X-ray novae are associated with bursts of gamma-rays. If so, GRB 070610 defines a new class of celestial gamma-ray bursts and these bursts dominate the long-duration GRB demographics

  8. [Takotsubo syndrome. Transient left ventricular dyskinesia].

    PubMed

    Pérez Pérez, F M; Sánchez Salado, J

    2014-03-01

    The Takotsubo syndrome, also called transient apical dyskinesia syndrome, was first described in Japan in the 1990s. It is a rare entity found in almost 1% of all patients with suspicion of acute coronary syndrome. It usually affects postmenopausal women with a few cardiovascular risk factors. It is characterized by angina-type chest pain, electrocardiographic changes, elevation of the enzymes of myocardial injury, absence of coronary obstruction on angiography, and a characteristic left ventricular anteroapical dyskinesia, which returns to normal within a few days. Severe emotional stress is the most common trigger for this syndrome. The aetiopathogenesis of this syndrome remains to be defined. This syndrome has been considered a clinical condition since 2001, when a series of 88 cases was published. It is a disease with a partially known mechanism, characterised by the morphology adopted by the left ventricle secondary to hypokinesis or dyskinesia of the apical segments, and hypercontractility of basal segments. Unlike acute coronary syndrome, patients with left ventricle dysfunction do not have atherothrombotic disease in the coronary arteries. In addition, the alterations described are reversible. Some clinical diagnostic criteria have been proposed, although they are still controversial, as well as in the complementary examinations required for diagnosis.

  9. Transient Mixing Driven by Buoyancy Flows

    NASA Technical Reports Server (NTRS)

    Duval, W. M. B.; Batur, C.; Zhong, H.

    2002-01-01

    Mixing driven by buoyancy-induced flows is of particular interest to microgravity processes, as the body force that governs the intensity of flow fields can be directly controlled. We consider a model experimental system to explore the dynamics of mixing which employs two miscible liquids inside a cavity separated initially by a divider. The two liquids are oriented vertically inside a rectangular cavity with constant width and height, and varying depths to span the range of a Hele-Shaw cell to a 3-D configuration. The two miscible liquids can be sufficiently diluted and died, for example water and deuterium oxide, such that a distinct interface exists across the divider. The transient mixing characteristic of the two fluids is addressed by following the Lagrangian history of the interface for various aspect ratios in the z-plane (depth variation) as well as a range of pulling velocities of the divider. The mixing characteristics of the two fluids are quantified from measurement of the length stretch of the interface and its flow field using respectively image processing techniques and Particle Imaging Velocimetry. Scaling analysis shows that the length stretch depends on four governing parameters, namely the Grashof number (Gr), Schmidt number (Sc), aspect ratio (Ar), and Reynolds number (Re). Variation of the Schmidt number is taken into account through thermophysical property variation. Thus our problem reduces to a codimension three bifurcation in parametric space for Gr, Ar, and Re.

  10. Solar activity and explosive transient eruptions

    NASA Astrophysics Data System (ADS)

    Ambastha, Ashok

    2016-07-01

    We discuss active and explosive behavior of the Sun observable in a wide range of wavelengths (or energies) and spatio-temporal scales that are not possible for any other star. On the longer time scales, the most notable form of solar activity is the well known so called 11-year solar activity cycle. On the other hand, at shorter time scales of a few minutes to several hours, spectacular explosive transient events, such as, solar flares, prominence eruptions, and coronal mass ejections (CMEs) occur in the outer layers of solar atmosphere. These solar activity cycle and explosive phenomena influence and disturb the space between the Sun and planets. The state of the interplanetary medium, including planetary and terrestrial surroundings, or "the space weather", and its forecasting has important practical consequences. The reliable forecasting of space weather lies in continuously observing of the Sun. We present an account of the recent developments in our understanding of these phenomena using both space-borne and ground-based solar observations.

  11. Transient pulsed radio emission from a magnetar.

    PubMed

    Camilo, Fernando; Ransom, Scott M; Halpern, Jules P; Reynolds, John; Helfand, David J; Zimmerman, Neil; Sarkissian, John

    2006-08-24

    Anomalous X-ray pulsars (AXPs) are slowly rotating neutron stars with very bright and highly variable X-ray emission that are believed to be powered by ultra-strong magnetic fields of >10(14) G, according to the 'magnetar' model. The radio pulsations that have been observed from more than 1,700 neutron stars with weaker magnetic fields have never been detected from any of the dozen known magnetars. The X-ray pulsar XTE J1810-197 was revealed (in 2003) as the first AXP with transient emission when its luminosity increased 100-fold from the quiescent level; a coincident radio source of unknown origin was detected one year later. Here we show that XTE J1810-197 emits bright, narrow, highly linearly polarized radio pulses, observed at every rotation, thereby establishing that magnetars can be radio pulsars. There is no evidence of radio emission before the 2003 X-ray outburst (unlike ordinary pulsars, which emit radio pulses all the time), and the flux varies from day to day. The flux at all radio frequencies is approximately equal--and at >20 GHz XTE J1810-197 is currently the brightest neutron star known. These observations link magnetars to ordinary radio pulsars, rule out alternative accretion models for AXPs, and provide a new window into the coronae of magnetars.

  12. Three Decades of High Energy Transients

    NASA Technical Reports Server (NTRS)

    Kouveliotou, Chryssa

    2012-01-01

    Gamma-Ray Bursts are the most brilliant explosions in space. The first GRB was discovered on 1967, just over 40 years ago. It took several years and multiple generations of space and ground instruments to unravel some of the mysteries of this phenomenon. However, many questions remain open today. I will discuss the history, evolution and current status of the GRB field and its contributions in our understanding of the transient high energy sky. Finally, I will describe how GRBs can be utilized in future missions as tools, to probe the cosmic chemical evolution of the Universe Magnetars are magnetically powered rotating neutron stars with extreme magnetic fields (over 10(exp 14) Gauss). They were discovered in the X- and gamma-rays where they predominantly emit their radiation. Very few sources (roughly 24) have been found since their discovery in 1987. NASA's Fermi Gamma-ray Space Telescope was launched June 11, 2009; since then the Fermi Gamma-ray Burst Monitor (GBM) recorded emission from several magnetar sources. In total, six new sources were discovered between 2008 and 2011, with a synergy between Swift, RXTE, Fermi and the Interplanetary Network (IPN). I will give a short history of magnetars and describe how this, once relatively esoteric field, has emerged as a link between several astrophysical areas including Gamma-Ray Bursts.

  13. Automated Fluid Feature Extraction from Transient Simulations

    NASA Technical Reports Server (NTRS)

    Haimes, Robert

    1998-01-01

    In the past, feature extraction and identification were interesting concepts, but not required to understand the underlying physics of a steady flow field. This is because the results of the more traditional tools like iso-surfaces, cuts and streamlines were more interactive and easily abstracted so they could be represented to the investigator. These tools worked and properly conveyed the collected information at the expense of much interaction. For unsteady flow-fields, the investigator does not have the luxury of spending time scanning only one 'snap-shot' of the simulation. Automated assistance is required in pointing out areas of potential interest contained within the flow. This must not require a heavy compute burden (the visualization should not significantly slow down the solution procedure for co-processing environments like pV3). And methods must be developed to abstract the feature and display it in a manner that physically makes sense. The following is a list of the important physical phenomena found in transient (and steady-state) fluid flow: Shocks; Vortex ores; Regions of Recirculation; Boundary Layers; Wakes.

  14. Automated Fluid Feature Extraction from Transient Simulations

    NASA Technical Reports Server (NTRS)

    Haimes, Robert; Lovely, David

    1999-01-01

    In the past, feature extraction and identification were interesting concepts, but not required to understand the underlying physics of a steady flow field. This is because the results of the more traditional tools like iso-surfaces, cuts and streamlines were more interactive and easily abstracted so they could be represented to the investigator. These tools worked and properly conveyed the collected information at the expense of much interaction. For unsteady flow-fields, the investigator does not have the luxury of spending time scanning only one "snap-shot" of the simulation. Automated assistance is required in pointing out areas of potential interest contained within the flow. This must not require a heavy compute burden (the visualization should not significantly slow down the solution procedure for co-processing environments like pV3). And methods must be developed to abstract the feature and display it in a manner that physically makes sense. The following is a list of the important physical phenomena found in transient (and steady-state) fluid flow: (1) Shocks, (2) Vortex cores, (3) Regions of recirculation, (4) Boundary layers, (5) Wakes. Three papers and an initial specification for the (The Fluid eXtraction tool kit) FX Programmer's guide were included. The papers, submitted to the AIAA Computational Fluid Dynamics Conference, are entitled : (1) Using Residence Time for the Extraction of Recirculation Regions, (2) Shock Detection from Computational Fluid Dynamics results and (3) On the Velocity Gradient Tensor and Fluid Feature Extraction.

  15. Investigation of Transient Performance for a Sublimator

    NASA Technical Reports Server (NTRS)

    Leimkuehler, Thomas O.; Sheth, Rubik; Stephan, Ryan A.

    2009-01-01

    Sublimators have been used as heat rejection devices for a variety of space applications including the Apollo Lunar Module and the Extravehicular Mobility Unit (EMU). Sublimators typically operate with steady-state feedwater utilization at or near 100%. However, sublimators are currently being considered to operate in a cyclical topping mode during low lunar orbit for Altair and possibly Orion, which represents a new mode of operation for sublimators. In this mission phase, the sublimator will be repeatedly started and stopped during each orbit to provide supplemental heat rejection for the portion of the orbit where the sink temperature exceeds the system setpoint temperature. This paper will investigate the effects of these transient starts and stops on the feedwater utilization during various feedwater timing scenarios. The X-38 sublimator, which represents the state of the art in sublimator technology, was used to understand this behavior and to quantify the feedwater performance. Data from various scenarios will be analyzed to investigate feedwater utilization under the cyclical conditions. This paper will also provide recommendations for future sublimator designs and/or feedwater control.

  16. Gas-Dynamic Transients Flow Networks

    1987-09-01

    TVENT1P predicts flows and pressures in a ventilation system or other air pathway caused by pressure transients, such as a tornado. For an analytical model to simulate an actual system, it must have (1) the same arrangement of components in a network of flow paths; (2) the same friction characteristics; (3) the same boundary pressures; (4) the same capacitance; and (5) the same forces that drive the air. A specific set of components used formore » constructing the analytical model includes filters, dampers, ducts, blowers, rooms, or volume connected at nodal points to form networks. The effects of a number of similar components can be lumped into a single one. TVENT1P contains a material transport algorithm and features for turning blowers off and on, changing blower speeds, changing the resistance of dampers and filters, and providing a filter model to handle very high flows. These features make it possible to depict a sequence of events during a single run. Component properties are varied using time functions. The filter model is not used by the code unless it is specified by the user. The basic results of a TVENT1P solution are flows in branches and pressures at nodes. A postprocessor program, PLTTEX, is included to produce the plots specified in the TVENT1P input. PLTTEX uses the proprietary CA-DISSPLA graphics software.« less

  17. Transient Receptor Potential Channels in the Vasculature

    PubMed Central

    Earley, Scott; Brayden, Joseph E.

    2015-01-01

    The mammalian genome encodes 28 distinct members of the transient receptor potential (TRP) superfamily of cation channels, which exhibit varying degrees of selectivity for different ionic species. Multiple TRP channels are present in all cells and are involved in diverse aspects of cellular function, including sensory perception and signal transduction. Notably, TRP channels are involved in regulating vascular function and pathophysiology, the focus of this review. TRP channels in vascular smooth muscle cells participate in regulating contractility and proliferation, whereas endothelial TRP channel activity is an important contributor to endothelium-dependent vasodilation, vascular wall permeability, and angiogenesis. TRP channels are also present in perivascular sensory neurons and astrocytic endfeet proximal to cerebral arterioles, where they participate in the regulation of vascular tone. Almost all of these functions are mediated by changes in global intracellular Ca2+ levels or subcellular Ca2+ signaling events. In addition to directly mediating Ca2+ entry, TRP channels influence intracellular Ca2+ dynamics through membrane depolarization associated with the influx of cations or through receptor- or store-operated mechanisms. Dysregulation of TRP channels is associated with vascular-related pathologies, including hypertension, neointimal injury, ischemia-reperfusion injury, pulmonary edema, and neurogenic inflammation. In this review, we briefly consider general aspects of TRP channel biology and provide an in-depth discussion of the functions of TRP channels in vascular smooth muscle cells, endothelial cells, and perivascular cells under normal and pathophysiological conditions. PMID:25834234

  18. Hippocampal CA1 Ripples as Inhibitory Transients

    PubMed Central

    Krishnan, Giri P; Fellous, Jean-Marc; Bazhenov, Maxim

    2016-01-01

    Memories are stored and consolidated as a result of a dialogue between the hippocampus and cortex during sleep. Neurons active during behavior reactivate in both structures during sleep, in conjunction with characteristic brain oscillations that may form the neural substrate of memory consolidation. In the hippocampus, replay occurs within sharp wave-ripples: short bouts of high-frequency activity in area CA1 caused by excitatory activation from area CA3. In this work, we develop a computational model of ripple generation, motivated by in vivo rat data showing that ripples have a broad frequency distribution, exponential inter-arrival times and yet highly non-variable durations. Our study predicts that ripples are not persistent oscillations but result from a transient network behavior, induced by input from CA3, in which the high frequency synchronous firing of perisomatic interneurons does not depend on the time scale of synaptic inhibition. We found that noise-induced loss of synchrony among CA1 interneurons dynamically constrains individual ripple duration. Our study proposes a novel mechanism of hippocampal ripple generation consistent with a broad range of experimental data, and highlights the role of noise in regulating the duration of input-driven oscillatory spiking in an inhibitory network. PMID:27093059

  19. Transient particle acceleration associated with solar flares.

    PubMed

    Chupp, E L

    1990-10-12

    Understanding how individual charged particles can be accelerated to extreme energies (10(20) electron volts), remains a foremost problem in astrophysics. Within our solar system, the active sun is capable of producing, on a short time scale, ions with energies higher than 25 gigaelectron volts. Satellite and ground-based observation over the past 30 years have greatly increased our knowledge of the properties of transient bursts of energetic particles emitted from the sun in association with solar flares, but a real understanding of the solar flare particle acceleration process requires greatly refined experimental data. On the practical side, it is also imperative that this problem be solved if man is to venture, for long periods of time, beyond the protective umbrella of Earth's magnetic field, which excludes much of the biologically damaging solar energetic particles. It is only through an understanding of the basic acceleration problem that we can expect to be able to predict the occurrence of a solar flare with lethal solar radiations. For our knowledge of these effects to advance, a new space mission dedicated to studying the high-energy aspects of solar flares at high spatial and energy resolution will be required.

  20. Transient dynamics capability at Sandia National Laboratories

    NASA Technical Reports Server (NTRS)

    Attaway, Steven W.; Biffle, Johnny H.; Sjaardema, G. D.; Heinstein, M. W.; Schoof, L. A.

    1993-01-01

    A brief overview of the transient dynamics capabilities at Sandia National Laboratories, with an emphasis on recent new developments and current research is presented. In addition, the Sandia National Laboratories (SNL) Engineering Analysis Code Access System (SEACAS), which is a collection of structural and thermal codes and utilities used by analysts at SNL, is described. The SEACAS system includes pre- and post-processing codes, analysis codes, database translation codes, support libraries, Unix shell scripts for execution, and an installation system. SEACAS is used at SNL on a daily basis as a production, research, and development system for the engineering analysts and code developers. Over the past year, approximately 190 days of CPU time were used by SEACAS codes on jobs running from a few seconds up to two and one-half days of CPU time. SEACAS is running on several different systems at SNL including Cray Unicos, Hewlett Packard PH-UX, Digital Equipment Ultrix, and Sun SunOS. An overview of SEACAS, including a short description of the codes in the system, are presented. Abstracts and references for the codes are listed at the end of the report.

  1. Transient analysis of a chemical synaptic transmission.

    PubMed

    Melkonian, D S

    1993-01-01

    The statistical dynamics of an impulse induced quanta turnover is studied by means of a nonstationary stochastic model--double barrier synapse--resulting from a previously developed mathematical theory of chemical synaptic transmission. An essential aspect of nonstationarities of the model is that the interpool quanta transfers follow binomial distribution at impulse arrival time, while in the absence of stimulation they obey Yule-Furry statistics. Under a variety of conditions, corresponding to those in actual experiments, the transient behaviour of the model is simulated and analysed in detail. As a result, the quantitative description of immediate and delayed components of synaptic action is introduced. If simulations of quantal fluctuations are performed numerically, then for the treatment of dynamic regularities, besides numerical procedures, an analytical method of envelopes is developed. It is supported by the theorems which reduce behaviour of the double-barrier synapse to the super-position of simpler solutions for single-barrier systems. With short-term facilitation quantitative analysis and simulations, the synaptic resonance phenomenon is theoretically predicted: different resonant frequencies are found at different levels of facilitation. The importance of this phenomenon treated as a clue to the information processing capabilities of a chemical synapse is discussed. PMID:8097407

  2. Gas-core reactor power transient analysis

    NASA Technical Reports Server (NTRS)

    Kascak, A. F.

    1972-01-01

    The gas core reactor is a proposed device which features high temperatures. It has applications in high specific impulse space missions, and possibly in low thermal pollution MHD power plants. The nuclear fuel is a ball of uranium plasma radiating thermal photons as opposed to gamma rays. This thermal energy is picked up before it reaches the solid cavity liner by an inflowing seeded propellant stream and convected out through a rocket nozzle. A wall-burnout condition will exist if there is not enough flow of propellant to convect the energy back into the cavity. A reactor must therefore operate with a certain amount of excess propellant flow. Due to the thermal inertia of the flowing propellant, the reactor can undergo power transients in excess of the steady-state wall burnout power for short periods of time. The objective of this study was to determine how long the wall burnout power could be exceeded without burning out the cavity liner. The model used in the heat-transfer calculation was one-dimensional, and thermal radiation was assumed to be a diffusion process.

  3. PoET: Polarimeters for Energetic Transients

    NASA Technical Reports Server (NTRS)

    McConnell, Mark; Barthelmy, Scott; Hill, Joanne

    2008-01-01

    This presentation focuses on PoET (Polarimeters for Energetic Transients): a Small Explorer mission concept proposed to NASA in January 2008. The principal scientific goal of POET is to measure GRB polarization between 2 and 500 keV. The payload consists of two wide FoV instruments: a Low Energy Polarimeter (LEP) capable of polarization measurements in the energy range from 2-15 keV and a high energy polarimeter (Gamma-Ray Polarimeter Experiment - GRAPE) that will measure polarization in the 60-500 keV energy range. Spectra will be measured from 2 keV up to 1 MeV. The PoET spacecraft provides a zenith-pointed platform for maximizing the exposure to deep space. Spacecraft rotation will provide a means of effectively dealing with systematics in the polarization response. PoET will provide sufficient sensitivity and sky coverage to measure statistically significant polarization for up to 100 GRBs in a two-year mission. Polarization data will also be obtained for solar flares, pulsars and other sources of astronomical interest.

  4. The placenta: a multifaceted, transient organ.

    PubMed

    Burton, Graham J; Fowden, Abigail L

    2015-03-01

    The placenta is arguably the most important organ of the body, but paradoxically the most poorly understood. During its transient existence, it performs actions that are later taken on by diverse separate organs, including the lungs, liver, gut, kidneys and endocrine glands. Its principal function is to supply the fetus, and in particular, the fetal brain, with oxygen and nutrients. The placenta is structurally adapted to achieve this, possessing a large surface area for exchange and a thin interhaemal membrane separating the maternal and fetal circulations. In addition, it adopts other strategies that are key to facilitating transfer, including remodelling of the maternal uterine arteries that supply the placenta to ensure optimal perfusion. Furthermore, placental hormones have profound effects on maternal metabolism, initially building up her energy reserves and then releasing these to support fetal growth in later pregnancy and lactation post-natally. Bipedalism has posed unique haemodynamic challenges to the placental circulation, as pressure applied to the vena cava by the pregnant uterus may compromise venous return to the heart. These challenges, along with the immune interactions involved in maternal arterial remodelling, may explain complications of pregnancy that are almost unique to the human, including pre-eclampsia. Such complications may represent a trade-off against the provision for a large fetal brain.

  5. Transient flows and pressure waves in pipes

    SciTech Connect

    Wang, X.Q.; Sun, J.G.; Sha, W.T.

    1994-06-01

    Transient laminar flows and pressure-wave propagations in pipes connected with components, commonly known as water hammer, are analyzed. The system studied consists of a constant-pressure vessel, a uniform circular pipe, a valve between them, and a receiver vessel. A pressure-wave equation and a linearized velocity equation are derived from the equations of mass and momentum conservation. Waveform distortion due to viscous dissipation and pipe-wall elastic expansion is characterized by a dimensionless transmission number, K. The coefficients of the damping of the pressure waves were found to be related to the roots of the Bessel function J{sub 0}. An exact solution of the pressure-wave equation was obtained numerically. The relationship between the distortion of a traveling wave and the transmission number K was studied. The problem is also calculated with a general-purpose computer code, COMMIX, which solves the exact mass conservation equation and Navier-Stokes equations. The COMMIX calculational results agreed well with the analytical solutions.

  6. A Catalog of Coronal "EIT Wave" Transients

    NASA Technical Reports Server (NTRS)

    Thompson, B. J.; Myers, D. C.

    2009-01-01

    Solar and Heliospheric Observatory (SOHO) Extreme ultraviolet Imaging Telescope (EIT) data have been visually searched for coronal "EIT wave" transients over the period beginning from 1997 March 24 and extending through 1998 June 24. The dates covered start at the beginning of regular high-cadence (more than one image every 20 minutes) observations, ending at the four-month interruption of SOHO observations in mid-1998. One hundred and seventy six events are included in this catalog. The observations range from "candidate" events, which were either weak or had insufficient data coverage, to events which were well defined and were clearly distinguishable in the data. Included in the catalog are times of the EIT images in which the events are observed, diagrams indicating the observed locations of the wave fronts and associated active regions, and the speeds of the wave fronts. The measured speeds of the wave fronts varied from less than 50 to over 700 km s(exp -1) with "typical" speeds of 200-400 km s(exp -1).

  7. The placenta: a multifaceted, transient organ

    PubMed Central

    Burton, Graham J.; Fowden, Abigail L.

    2015-01-01

    The placenta is arguably the most important organ of the body, but paradoxically the most poorly understood. During its transient existence, it performs actions that are later taken on by diverse separate organs, including the lungs, liver, gut, kidneys and endocrine glands. Its principal function is to supply the fetus, and in particular, the fetal brain, with oxygen and nutrients. The placenta is structurally adapted to achieve this, possessing a large surface area for exchange and a thin interhaemal membrane separating the maternal and fetal circulations. In addition, it adopts other strategies that are key to facilitating transfer, including remodelling of the maternal uterine arteries that supply the placenta to ensure optimal perfusion. Furthermore, placental hormones have profound effects on maternal metabolism, initially building up her energy reserves and then releasing these to support fetal growth in later pregnancy and lactation post-natally. Bipedalism has posed unique haemodynamic challenges to the placental circulation, as pressure applied to the vena cava by the pregnant uterus may compromise venous return to the heart. These challenges, along with the immune interactions involved in maternal arterial remodelling, may explain complications of pregnancy that are almost unique to the human, including pre-eclampsia. Such complications may represent a trade-off against the provision for a large fetal brain. PMID:25602070

  8. Large Angle Transient Dynamics (LATDYN) user's manual

    NASA Technical Reports Server (NTRS)

    Abrahamson, A. Louis; Chang, Che-Wei; Powell, Michael G.; Wu, Shih-Chin; Bingel, Bradford D.; Theophilos, Paula M.

    1991-01-01

    A computer code for modeling the large angle transient dynamics (LATDYN) of structures was developed to investigate techniques for analyzing flexible deformation and control/structure interaction problems associated with large angular motions of spacecraft. This type of analysis is beyond the routine capability of conventional analytical tools without simplifying assumptions. In some instances, the motion may be sufficiently slow and the spacecraft (or component) sufficiently rigid to simplify analyses of dynamics and controls by making pseudo-static and/or rigid body assumptions. The LATDYN introduces a new approach to the problem by combining finite element structural analysis, multi-body dynamics, and control system analysis in a single tool. It includes a type of finite element that can deform and rotate through large angles at the same time, and which can be connected to other finite elements either rigidly or through mechanical joints. The LATDYN also provides symbolic capabilities for modeling control systems which are interfaced directly with the finite element structural model. Thus, the nonlinear equations representing the structural model are integrated along with the equations representing sensors, processing, and controls as a coupled system.

  9. Lightcurve Based Classification Of Transients Events

    NASA Astrophysics Data System (ADS)

    Donalek, Ciro; Graham, M. J.; Mahabal, A.; Djorgovski, S. G.; Drake, A. J.; Moghaddam, B.; Turmon, M.; Chen, Y.; Sharma, N.

    2012-01-01

    In many scientific fields, a new generation of instruments is generating exponentially growing data streams, that may enable significant new discoveries. The requirement to perform the analysis rapidly and objectively, coupled with the huge amount of data available, implies a need for an automated event detection, classification, and decision making. In astronomy, this is the case with the new generation of synoptic sky surveys, that discover an ever increasing number of transient events. However, not all of them are equally interesting and worthy of a follow-up with limited resources. This presents some unusual classification challenges: the data are sparse, heterogeneous and incomplete; evolving in time; and most of the relevant information comes from a variety of archival data and contextual information. We are exploring a variety of machine learning techniques, using the ongoing CRTS sky survey as a testbed: Bayesian Network, [dm,dt] histograms, Decision Trees, Neural Networks, Symbolic Regression. In this work we focus on the lightcurve based classification using an hierarchical approach where some astrophysically motivated major features are used to separate different groups of classes. Proceeding down the classification hierarchy every node uses those classifiers that are demonstrated to work best for that particular task.

  10. Evolution und Kreationismus im Schulunterricht aus Sicht Großbritanniens. Ist Evolution eine Sache der Akzeptanz oder des Glaubens?

    NASA Astrophysics Data System (ADS)

    Williams, James D.

    Ist Kreationismus eine Weltanschauung oder eine falsche Vorstellung? Ausgehend vom Standpunkt der Naturwissenschaft ist der Unterschied wichtig. Falsche Vorstellungen können herausgefordert und durch gründliche wissenschaftliche Lehre korrigiert werden. Weltanschauungen sind Teil eines etablierten Glaubenssystems, und diese Überzeugungen sind von Natur aus schwer zu verändern (Cohen 1992).

  11. Swift/BAT and MAXI/GSC broadband transient monitor

    NASA Astrophysics Data System (ADS)

    Sakamoto, Takanori; Oda, Ryoma; Mihara, Tatehiro; Yoshida, Atsumasa; Arimoto, Makoto; Barthelmy, Scott Douglas; Kawai, Nobuyuki; Krimm, Hans A.; Nakahira, Satoshi; Serino, Motoko

    2016-04-01

    "Time-domain astronomy" is one of the frontier field of astronomy for the next decade. Since the most of the transient sources show the temporal variation in a broad spectral range, it would be ideal to have the real time transient monitor which covers a wide energy band. We present the newly developed broadband transient monitor using the Swift Burst Alert Telescope (BAT) and the MAXI Gas Slit Camera (GSC) data. Our broadband transient monitor monitors high-energy transient sources from 2 keV to 200 keV in seven energy bands by combining the BAT (15-200keV) and the GSC (2-20keV) data. Currently, daily and 90-minute (one orbit) averaged light curves are available for 106 high-energy transient sources. Our broadband transient monitor is available to the public through our web server, http://yoshidalab.mydns.jp/bat_gsc_trans_mon/, for wider use by the community. We discuss the daily sensitivity of our monitor and possible future improvements to our pipeline.

  12. VAST: An ASKAP Survey for Variables and Slow Transients

    NASA Astrophysics Data System (ADS)

    Murphy, Tara; Chatterjee, Shami; Kaplan, David L.; Banyer, Jay; Bell, Martin E.; Bignall, Hayley E.; Bower, Geoffrey C.; Cameron, Robert A.; Coward, David M.; Cordes, James M.; Croft, Steve; Curran, James R.; Djorgovski, S. G.; Farrell, Sean A.; Frail, Dale A.; Gaensler, B. M.; Galloway, Duncan K.; Gendre, Bruce; Green, Anne J.; Hancock, Paul J.; Johnston, Simon; Kamble, Atish; Law, Casey J.; Lazio, T. Joseph W.; Lo, Kitty K.; Macquart, Jean-Pierre; Rea, Nanda; Rebbapragada, Umaa; Reynolds, Cormac; Ryder, Stuart D.; Schmidt, Brian; Soria, Roberto; Stairs, Ingrid H.; Tingay, Steven J.; Torkelsson, Ulf; Wagstaff, Kiri; Walker, Mark; Wayth, Randall B.; Williams, Peter K. G.

    2013-02-01

    The Australian Square Kilometre Array Pathfinder (ASKAP) will give us an unprecedented opportunity to investigate the transient sky at radio wavelengths. In this paper we present VAST, an ASKAP survey for Variables and Slow Transients. VAST will exploit the wide-field survey capabilities of ASKAP to enable the discovery and investigation of variable and transient phenomena from the local to the cosmological, including flare stars, intermittent pulsars, X-ray binaries, magnetars, extreme scattering events, interstellar scintillation, radio supernovae, and orphan afterglows of gamma-ray bursts. In addition, it will allow us to probe unexplored regions of parameter space where new classes of transient sources may be detected. In this paper we review the known radio transient and variable populations and the current results from blind radio surveys. We outline a comprehensive program based on a multi-tiered survey strategy to characterise the radio transient sky through detection and monitoring of transient and variable sources on the ASKAP imaging timescales of 5 s and greater. We also present an analysis of the expected source populations that we will be able to detect with VAST.

  13. The Palomar Transient Factory: System Overview, Performance, and First Results

    NASA Astrophysics Data System (ADS)

    Law, Nicholas M.; Kulkarni, Shrinivas R.; Dekany, Richard G.; Ofek, Eran O.; Quimby, Robert M.; Nugent, Peter E.; Surace, Jason; Grillmair, Carl C.; Bloom, Joshua S.; Kasliwal, Mansi M.; Bildsten, Lars; Brown, Tim; Cenko, S. Bradley; Ciardi, David; Croner, Ernest; Djorgovski, S. George; van Eyken, Julian; Filippenko, Alexei V.; Fox, Derek B.; Gal-Yam, Avishay; Hale, David; Hamam, Nouhad; Helou, George; Henning, John; Howell, D. Andrew; Jacobsen, Janet; Laher, Russ; Mattingly, Sean; McKenna, Dan; Pickles, Andrew; Poznanski, Dovi; Rahmer, Gustavo; Rau, Arne; Rosing, Wayne; Shara, Michael; Smith, Roger; Starr, Dan; Sullivan, Mark; Velur, Viswa; Walters, Richard; Zolkower, Jeff

    2009-12-01

    The Palomar Transient Factory (PTF) is a fully-automated, wide-field survey aimed at a systematic exploration of the optical transient sky. The transient survey is performed using a new 8.1 square degree camera installed on the 48 inch Samuel Oschin telescope at Palomar Observatory; colors and light curves for detected transients are obtained with the automated Palomar 60 inch telescope. PTF uses 80% of the 1.2 m and 50% of the 1.5 m telescope time. With an exposure of 60 s the survey reaches a depth of mg' ≈ 21.3 and mR ≈ 20.6 (5σ, median seeing). Four major experiments are planned for the five-year project: (1) a 5 day cadence supernova search; (2) a rapid transient search with cadences between 90 s and 1 day (3) a search for eclipsing binaries and transiting planets in Orion; and (4) a 3π sr deep H-alpha survey. PTF provides automatic, real-time transient classification and follow-up, as well as a database including every source detected in each frame. This paper summarizes the PTF project, including several months of on-sky performance tests of the new survey camera, the observing plans, and the data reduction strategy. We conclude by detailing the first 51 PTF optical transient detections, found in commissioning data.

  14. Capture-recapture survival models taking account of transients

    USGS Publications Warehouse

    Pradel, R.; Hines, J.E.; Lebreton, J.D.; Nichols, J.D.

    1997-01-01

    The presence of transient animals, common enough in natural populations, invalidates the estimation of survival by traditional capture- recapture (CR) models designed for the study of residents only. Also, the study of transit is interesting in itself. We thus develop here a class of CR models to describe the presence of transients. In order to assess the merits of this approach we examme the bias of the traditional survival estimators in the presence of transients in relation to the power of different tests for detecting transients. We also compare the relative efficiency of an ad hoc approach to dealing with transients that leaves out the first observation of each animal. We then study a real example using lazuli bunting (Passerina amoena) and, in conclusion, discuss the design of an experiment aiming at the estimation of transience. In practice, the presence of transients is easily detected whenever the risk of bias is high. The ad hoc approach, which yields unbiased estimates for residents only, is satisfactory in a time-dependent context but poorly efficient when parameters are constant. The example shows that intermediate situations between strict 'residence' and strict 'transience' may exist in certain studies. Yet, most of the time, if the study design takes into account the expected length of stay of a transient, it should be possible to efficiently separate the two categories of animals.

  15. Analysis of Stable and Transient Protein-Protein Interactions

    PubMed Central

    Byrum, Stephanie; Smart, Sherri K.; Larson, Signe; Tackett, Alan J.

    2012-01-01

    The assembly of proteins into defined complexes drives a plethora of cellular activities. These protein complexes often have a set of more stably interacting proteins as well as more unstable or transient interactions. Studying the in vivo components of these protein complexes is challenging as many of the techniques used for isolation result in the purification of only the most stable components and the transient interactions are lost. A technology called transient isotopic differentiation of interactions as random or targeted (transient I-DIRT) has been developed to identify these transiently interacting proteins as well as the stable interactions. Described here are the detailed methodological approaches used for a transient I-DIRT analysis of a multi-subunit complex, NuA3, that acetylates histone H3 and functions to activate gene transcription. Transcription is known to involve a concert of protein assemblies performing different activities on the chromatin/gene template, thus understanding the less stable or transient protein interactions with NuA3 will shed light onto the protein complexes that function synergistically, or antagonistically, to regulate gene transcription and chromatin remodeling. PMID:22183593

  16. Zivilisationsdynamik: Treiber Technik, Folgen und Konsequenzen. Civilisation dynamics: driving force technology, results and consequences

    NASA Astrophysics Data System (ADS)

    Jischa, Michael F.

    2010-11-01

    Die Menschheitsgeschichte ist untrennbar mit der Nutzung von Materie, Energie und Information verbunden. Im Laufe der Geschichte sind Produktivität, Bevölkerung und Ressourcenverbrauch ständig angestiegen, seit dem vergangenen Jahrhundert mit zunehmender Beschleunigung. In den früh industrialisierten Ländern entwickelte sich vor wenigen Jahrzehnten eine Bewusstseinswende, die Segnungen der Technik wurden zunehmend kritisch beurteilt. Das führte zur Formulierung des Leitbildes Nachhaltigkeit und unterschiedlichen Ansätzen, dieses zu operationalisieren, aus Sicht der Ingenieure mit dem Konzept Technikbewertung. Nach den Natur- und den Ingenieurwissenschaften haben die Gesellschaftswissenschaften diese Themen aufgegriffen, was zu einer teilweisen Annäherung der Zwei Kulturen geführt hat. Weiter sind Überlegungen entstanden, Lehr- und Forschungsinhalte zu überdenken, um auf die Weltprobleme (in der Sprache des Club of Rome) angemessen reagieren zu können. In jüngerer Zeit wurden Energieszenarien vorgestellt, deren Kernaussage unmissverständlich lautet: Die Zukunft gehört den erneuerbaren Energien.

  17. Molekulare Methoden zum Nachweis, zur Quantifizierung und zum Monitoring der Mykotoxinbildung lebensmittelrelevanter Pilze

    NASA Astrophysics Data System (ADS)

    Geisen, Rolf

    Schimmelpilze kommen ubiquitär vor und spielen besonders bei pflanzlichen Lebensmitteln und Rohprodukten eine besondere Rolle als Verderbsorganismen. Es wird geschätzt, dass 20-25 % der jährlichen Produktion an pflanzlichen Produkten durch Schimmelpilze verdorben werden (Smith et al., 1994). Viele der lebensmittelrelevanten Schimmelpilze sind zudem in der Lage, Mykotoxine, toxische Sekundärmetabolite, zu bilden, was das Ausmaß des Problems deutlich macht. Die wichtigsten mykotoxinbildenden Spezies gehören zu den Fusarien (Trichothecene, Fumonisine, Zearalenon), Aspergillen (Aflatoxin, Ochratoxin, Cyclopiazonsäure) und Penicillien (Patulin, Ochratoxin). Für viele Mykotoxine, wie die Aflatoxine, Ochratoxin, Fumonisine und Trichothecene sind Grenzwerte erlassen worden, die die Verkehrsfähigkeit betroffener Produkte regeln. Die Einhaltung der Grenzwerte kann sehr genau durch offizielle chemisch-analytische Methoden, wie HPLC, GC-MS etc. kontrolliert werden. Diese analytischen Methoden sind aber für die Anwendung eines HACCP-Ansatzes zur Kontrolle der Mykotoxinbildung nur bedingt geeignet, da sie Endpunktkontrollen darstellen und nur das über eine längere Zeit gebildete Mykotoxin bestimmen. Sie sagen daher nichts über die biologischen Bedingungen zur Zeit der Bildung durch den Pilz aus.

  18. [Beweggründe von Krebspatienten für und gegen die Inanspruchnahme der Misteltherapie].

    PubMed

    Gschwendtner, Kathrin M; Holmberg, Christine; Weis, Joachim

    2016-01-01

    Einleitung: Die Misteltherapie ist im deutschsprachigen Raum ein häufig angewandtes komplementärmedizinisches Verfahren (KM) in der Onkologie. Diese Studie hatte das Ziel, die Beweggründe für oder gegen eine Inanspruchnahme der Misteltherapie zu untersuchen und Themenfeldern zuzuordnen. Patienten und Methoden: Es wurden qualitative leitfadengestützte Interviews mit Krebspatienten geführt. Der Interviewleitfaden fragte nach der Inanspruchnahme von KM, der Motivation zur Inanspruchnahme, Informationsverhalten und -bedürfnissen zu KM sowie nach der Krebserkrankung. Um die Beweggründe für die Inanspruchnahme oder Nichtinanspruchnahme der Misteltherapie zu verstehen, wurden die Interviews inhaltsanalytisch ausgewertet. Ergebnisse: Insgesamt wurden Interviews mit 88 Krebspatienten geführt, davon nutzen 18 (20,5%) die Misteltherapie. Die Beweggründe für oder gegen eine Inanspruchnahme der Misteltherapie ließen sich den 2 Themenfeldern «Wahrgenommene Indikation» und «Abwägungen bei der Entscheidungsfindung» zuordnen. Diskussion und Schlussfolgerungen: Mit der Misteltherapie wird sowohl ein Einfluss auf das Tumorwachstum als auch eine supportive Wirkung assoziiert. Anwender sehen die Misteltherapie als sicheres Verfahren; Nichtnutzer befürchten eher Neben- oder Wechselwirkungen. Die Empfehlung von Fachpersonal spielt eine wichtige Rolle bei der Inanspruchnahme. Zum Teil waren die Nichtnutzer interessiert an der Anwendung der Misteltherapie, befanden sich jedoch noch im Klärungsprozess.

  19. Renaturierung von Feuchtgrünland, Auengrünland und mesophilem Grünland

    NASA Astrophysics Data System (ADS)

    Rosenthal, Gert; Hölzel, Norbert

    Grünland stellt in Mitteleuropa fast ausschließlich eine Kulturformation dar, die in der Naturlandschaft abgesehen von extremen Trocken- und Nassstandorten sowie klimatisch ungünstigen Gebieten oberhalb der alpinen Waldgrenze nur kleinflächig vertreten war.Die natürlichen Standorte der heutigen Grünlandarten waren in Mitteleuropa bis in das Atlantikum hinein Wälder oder natürlicherweise waldfreie ökosysteme, wie z.B. Röhricht- und Ufervegetation sowie Biberwiesen in Flussauen, Niedermoore, Randlaggs von Regenmooren, Waldlichtungen oder Lawinenbahnen (Ellenberg 1952, 1996). Die Naturlandschaft der heutigen Grünlandstandorte war durch die natürliche Dynamik der vorherrschenden Waldökosysteme mit ihren Entwicklungsstadien und natürlichen Störungsereignissen (Stürme, überschwemmungen etc.) geprägt. Der Flächenanteil des Grünlandes vergrößerte sich erst durch Beweidung und Heumahd durch den Menschen und seine Haustiere.

  20. Die Deutsche Statistische Gesellschaft in der Weimarer Republik und während der Nazidiktatur

    NASA Astrophysics Data System (ADS)

    Wilke, Jürgen

    Nach anfänglichen Schwierigkeiten durch den 1. Weltkrieg erlangte die Deutsche Statistische Gesellschaft (DStatG) unter dem renommierten Statistiker und Vorsitzenden der DStatG, Friedrich Zahn, durch eine Vielzahl von Aktivitäten hohes Ansehen. Es gab Bestrebungen, Statistiker aus allen Arbeitsfeldern der Statistik in die DStatG zu integrieren, wobei die "Mathematische Statistik" nur zögerlich akzeptiert wurde (Konjunkturforschung, Zeitreihenanalyse). Nach der Machtübernahme 1933 durch Adolf Hitler geriet die DStatG in das Fahrwasser nationalsozialistischer Ideologie und Politik (Führerprinzip, Gleichschaltung des Vereinswesens). Damit war eine personelle Umstrukturierung in der DStatG verbunden. Politisch Missliebige und rassisch Verfolgte mussten die DStatG verlassen (Bernstein, Freudenberg, Gumbel u.a.). Unter den Statistikern gab es alle Abstufungen im Verhalten zum Regime von Ablehnung und zwangsweiser Anpassung über bereitwilliges Mitläufertum bis zu bewusster Täterschaft. Besonders die Bevölkerungsstatistik wurde durch die NS- Rassenpolitik auf lange Sicht diskreditiert. Im Rahmen von Wirtschaftsplanung und Aufrüstung wurden neue zukunftsträchtige statistische Modelle (Grünig, Bramstedt, Leisse) entwickelt.