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Dissertations / Theses on the topic 'Niob'

Author: Grafiati
Published: 4 June 2021
Last updated: 26 April 2022

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1

Hellwig, Olav. "Oxidation of epitaxial Nb(110) films oxygen dissolution and oxide formation /." [S.l. : s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=959851933.

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2

Song, Gang. "Hydrogen in thin niobium films." [S.l. : s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=961906529.

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3

Dornheim, Martin. "Spannungen, Dehnungen und Lage der Phasengrenzen in dünnen Nb- und Y-Schichten bei Wasserstoffbe- und -entladung." [S.l.] : [s.n.], 2002. http://deposit.ddb.de/cgi-bin/dokserv?idn=965265641.

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4

Dietrich, Christof. "Rastertunnelmikroskopische Charakterisierung von Tunnelkontakten zur Herstellung Coulomb-blockierter Systeme bei Raumtemperatur." [S.l. : s.n.], 2006. http://nbn-resolving.de/urn:nbn:de:bsz:289-vts-56921.

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5

Barták, Tomáš. "Fyzikálně-chemické aspekty přípravy intermetalik TiAl obsahujících niob." Doctoral thesis, Vysoké učení technické v Brně. Fakulta chemická, 2014. http://www.nusl.cz/ntk/nusl-233383.

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Prezentovaná práce se zabývá vakuovým indukčním tavením intermetalické slitiny Ti-46Al-7Nb (at. %) v žáruvzdorných kelímcích na bázi Y2O3. Byla provedena série taveb pro teploty přehřátí taveniny 1630, 1680 and 1730 C a při různých dobách výdrže na této teplotě v rozmezí 5 až 30 minut. Ze slitin ztuhlých v tavících kelímcích byly připraveny metalografické výbrusy, které sloužily k hodnocení mikrostruktury a vyhodnocení složení fází. Pro získání těchto dat byly použity metosy elektronové mirkoskopie SEM a EDS. Kvantitativní hodnocení mikrostruktury, zejména obsahu oxidické faze ve slitině, bylo provedeno pomocí software Adaptive Contrast Control (ACC). Analýza obsahu kyslíku ve ztuhlé slitině byla provedena metodou IGF (fúze v inertním plynu). V této práci jsou pochody na rozhraní slitina/oxidický kelímek posuzovány také z termodynamického hlediska a to s použitím aktivit jednotlivých složek v systému. Data prezentovaná v této práci mohou být použita pro nastavení a optimalizaci procesů tavení intermetalik TiAlNb.
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6

Cura, Christian [Verfasser]. "Magnetostriktionsmessungen an supraleitenden Borkarbid- und Niob-Einkristallen / Christian Cura." Aachen : Shaker, 2003. http://d-nb.info/1179040570/34.

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7

Erdem, Esra [Verfasser]. "Mikroseigerungsverhalten von Niob in unterschiedlichen Erstarrungsstrukturen für Stahlstrangguss / Esra Erdem." Aachen : Shaker, 2011. http://d-nb.info/1080764259/34.

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8

Hochstuhl, P. [Verfasser]. "Gitterinstabilitaet und metastabile Phasen in Niob-Titan-Supraleitern / P. Hochstuhl." Karlsruhe : KIT-Bibliothek, 2016. http://d-nb.info/1196632286/34.

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9

Berendes, Antje. "Nitridierung von Vanadium und Niob mit einer Thermowaage bzw. dem rapid thermal processing." [S.l.] : [s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=971574464.

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10

Flach, S. [Verfasser]. "Untersuchung der Anregungsfunktionen fuer ³He-Reaktionen mit Niob und Yttrium / S. Flach." Karlsruhe : KIT-Bibliothek, 2010. http://d-nb.info/1188431722/34.

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11

Schwarz, W. [Verfasser]. "Charakterisierung von Tunnelbarrieren durch Leitfaehigkeitsmessungen an Niob-Nioboxid-Blei Kontakten / W. Schwarz." Karlsruhe : KIT-Bibliothek, 2011. http://d-nb.info/1189178257/34.

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12

Wollmann, Philipp. "Synthese und Funktion nanoskaliger Oxide auf Basis der Elemente Bismut und Niob." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-85784.

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Am Beispiel von ferroelektrischen Systemen auf Bismut-Basis (Bismutmolybdat, Bismutwolframat und Bismuttitanat) und von Strontiumbariumniobat werden neue Möglichkeiten zur Synthese solcher Nanopartikel aufgezeigt. Die Integration der Nanopartikel in transparente Nanokompositmaterialien und die Entwicklung neuer Precursoren für die Herstellung von Dünnschichtproben gehen den Untersuchungen zur Anwendung als elektrooptische aktive Materialien voraus. Durch weitere Anwendungsmöglichkeiten in der Photokatalyse, dem Test dampfadsorptiver Eigenschaften mit Hilfe eines neuartigen Adsorptionstesters (Infrasorb) und auch mit Hilfe der Ergebnisse der ferroelektrischen Charakterisierung von gesinterten Probenkörpern aus einem Spark-Plasma-Prozess wird ein gesamtheitlicher Überblick über die vielfältigen Aspekte in der Arbeit mit nanoskaligen, ferroelektrischen Materialien gegeben.
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13

Kobertz, Dietmar. "Thermodynamic studies of pure and of manganese doped lead titanate and sodium niobate with perovskite structure." Doctoral thesis, Katowice : Uniwersytet Śląski, 2014. http://hdl.handle.net/20.500.12128/5538.

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Praca zawiera wyniki termodynamicznych badań kryształów tytanianu ołowiu oraz niobianu sodu – czystych oraz domieszkowanych manganem. Zostały określone wartości entalpii, entropii, energii Gibbs’a, i aktywności chemicznej badanych kryształów. Badania zostały wykonane przy zastosowaniu pomiarów ciepła właściwego kryształów oraz badania produktów odparowanych do fazy gazowej, przy użyciu komórki Knudsena i spektrometrii masowej. Dane termodynamiczne zostały wyprowadzone poprzez zestawienie pomiarów odnoszących się do fazy stałej i gazowej. Zostały zidentyfikowane produkty rozkładu tytanianu ołowiu i niobianu sodu występujące w fazie gazowej, zmierzone ich ciśnienia parcjalne w zależności od temperatury i wyznaczone wartości stałych równowagowych. Określono entalpie ich sublimacji, formowania, reakcji. Wyznaczono zmiany entropii oraz entalpii związane z występującymi przemianami fazowymi. Wykazano długo-czasową stabilność badanych materiałów w warunkach wysokotemperaturowej równowagi termodynamicznej w oparciu o obliczoną niską wartość aktywności chemicznej. Wykazano, że domieszka manganu zmniejsza stabilność badanych kryształów. Pokazano, że jony manganu podstawiają się w miejsce jonów tytanu albo niobu, potwierdzając niektóre wcześniejsze wyniki i rozstrzygając sprzeczności znane z literatury. W oparciu o analizę ciepła właściwego określono w tych materiałach cechy strukturalnych przemian fazowych stowarzyszonych ze zmianą uporządkowania: paraelektrycznego, ferroelektrycznego i antyferroelektrycznego.
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14

Piosczyk, B. [Verfasser]. "Experimentelle Untersuchungen an supraleitenden Wendelresonatoren aus Niob im 100 MHz-Bereich / B. Piosczyk." Karlsruhe : KIT-Bibliothek, 2010. http://d-nb.info/1187253006/34.

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15

Bechlars, Bettina. "Synthese und Charakterisierung neuer Heterodimetallchalkogencluster der Elemente Niob und Tantal mit elektronenreichen Übergangsmetallen." [S.l. : s.n.], 2007. http://digbib.ubka.uni-karlsruhe.de/volltexte/1000006965.

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16

Grundner, M. [Verfasser]. "Oberflaechenuntersuchungen an Niob fuer supraleitende Resonatoren mittels der Roentgen-Photoelektronenspektroskopie und der Auger-Elektronenspektroskopie / M. Grundner." Karlsruhe : KIT-Bibliothek, 2010. http://d-nb.info/1188749641/34.

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17

Tomanic, Tihomir [Verfasser], and H. von [Akademischer Betreuer] Löhneysen. "Untersuchung des elektronischen Oberflächenzustands von Ag-Inseln auf supraleitendem Niob(110) / Tihomir Tomanic ; Betreuer: H. von Löhneysen." Karlsruhe : KIT-Bibliothek, 2012. http://d-nb.info/1025114337/34.

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18

Rammer, Barbara [Verfasser]. "Einfluss von Niob, Tantal, Molybdän und Wolfram auf die Hochtemperaturchlorbeständigkeit NiAl-basierter Werkstoffe und Beschichtungen / Barbara Rammer." Aachen : Shaker, 2014. http://d-nb.info/1053903952/34.

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19

Bechlars, Bettina [Verfasser], and D. [Akademischer Betreuer] Fenske. "Synthese und Charakterisierung neuer Heterodimetallchalkogencluster der Elemente Niob und Tantal mit elektronenreichen Übergangsmetallen / Bettina Bechlars ; Betreuer: D. Fenske." Karlsruhe : KIT-Bibliothek, 2007. http://d-nb.info/1186011270/34.

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20

Kneisel, P. [Verfasser]. "Zur Abhaengigkeit des Oberflaechenwiderstandes anodisierter Niob-Resonatoren von der Hochfrequenz-Feldstaerke zwischen 2 und 4 GHz / P. Kneisel." Karlsruhe : KIT-Bibliothek, 2010. http://d-nb.info/1187253448/34.

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21

Geisler, Stefanie. "Einfluss von Mikrolegierungselementen auf das Umwandlungs- und Entfestigungsverhalten warmgewalzter Stähle mit sehr niedrigem Kohlenstoffgehalt." Düsseldorf Verl. Stahleisen, 2008. http://d-nb.info/997725885/04.

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22

Oettinger, Marcus. "Nanoteilchen als Ausgangspunkt für künstliche Pinningzentren in Supraleitern." [S.l. : s.n.], 2007. http://nbn-resolving.de/urn:nbn:de:bsz:289-vts-61108.

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23

Rubitschek, Felix Verfasser], Hans-Jürgen [Akademischer Betreuer] Maier, and Gunter [Akademischer Betreuer] [Kullmer. "Biokompatible ultrafeinkörnige Niob-Zirkonium Legierungen - Integrität unter mechanischer und korrosiver Beanspruchung / Felix Rubitschek. Betreuer: Hans-Jürgen Maier ; Gunter Kullmer." Paderborn : Universitätsbibliothek, 2012. http://d-nb.info/1036553299/34.

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24

Rubitschek, Felix Verfasser], Hans Jürgen [Akademischer Betreuer] [Maier, and Gunter [Akademischer Betreuer] Kullmer. "Biokompatible ultrafeinkörnige Niob-Zirkonium Legierungen - Integrität unter mechanischer und korrosiver Beanspruchung / Felix Rubitschek. Betreuer: Hans-Jürgen Maier ; Gunter Kullmer." Paderborn : Universitätsbibliothek, 2012. http://nbn-resolving.de/urn:nbn:de:hbz:466:2-10272.

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25

Behrens, Niklas [Verfasser], Frank [Akademischer Betreuer] Endres, and Ulrich [Akademischer Betreuer] Kunz. "Elektrochemische Untersuchungen von reaktiven Substanzen in Ionischen Flüssigkeiten: eine Studie über Aminoorganosilane und Niob / Niklas Behrens ; Frank Endres, Ulrich Kunz." Clausthal-Zellerfeld : Technische Universität Clausthal, 2020. http://d-nb.info/1231362707/34.

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26

Straub, Rainer. "Abbildung von Flussquanten in YBa 2 Cu 3O7 -x SQUIDs und Josephsonströmen in YBa 2 Cu 3O7-x-Niob Kontakten." [S.l. : s.n.], 2003. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB10873186.

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27

Bresler, Johannes [Verfasser], Mathias [Akademischer Betreuer] Göken, Mathias [Gutachter] Göken, and Helmut [Gutachter] Clemens. "Einfluss der Legierungselemente Niob, Tantal und Zirkonium auf das Hochtemperaturverhalten volllamellarer Titanaluminide / Johannes Bresler ; Gutachter: Mathias Göken, Helmut Clemens ; Betreuer: Mathias Göken." Erlangen : FAU University Press, 2020. http://d-nb.info/1203377843/34.

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28

Wollmann, Philipp [Verfasser], Stefan [Akademischer Betreuer] Kaskel, and Ulrich [Akademischer Betreuer] Simon. "Synthese und Funktion nanoskaliger Oxide auf Basis der Elemente Bismut und Niob / Philipp Wollmann. Gutachter: Stefan Kaskel ; Ulrich Simon. Betreuer: Stefan Kaskel." Dresden : Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2012. http://d-nb.info/1068442832/34.

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29

Clausing, Aline [Verfasser], Klaus [Akademischer Betreuer] Stöwe, Klaus [Gutachter] Stöwe, and Marc [Gutachter] Armbrüster. "Synthese und Charakterisierung Niob- und Tantal-dotierter Zinnoxide als potentielle Katalysatorträgermaterialien für Brennstoffzellen / Aline Clausing ; Gutachter: Klaus Stöwe, Marc Armbrüster ; Betreuer: Klaus Stöwe." Chemnitz : Technische Universität Chemnitz, 2019. http://d-nb.info/1215909896/34.

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30

Sen, S. [Verfasser]. "Der Einfluss von Bor auf das Zeitstand- und Kriechverhalten des unstabilisierten und Niob-stabilisierten Stahles X8CrNi 1613 im unbestrahlten und bestrahlten Zustand / S. Sen." Karlsruhe : KIT-Bibliothek, 2010. http://d-nb.info/118793304X/34.

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31

Grünzweig, Matthias Sebastian Peter [Verfasser], and Dieter [Akademischer Betreuer] Kölle. "Inbetriebnahme und Modifikation eines Tieftemperatur-Raster-Polarisations-Mikroskops (TTRPM) und Abbildung der lokalen Flussdichteverteilung in supraleitenden Niob-Proben / Matthias Sebastian Peter Grünzweig ; Betreuer: Dieter Kölle." Tübingen : Universitätsbibliothek Tübingen, 2015. http://d-nb.info/1163320811/34.

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32

Frejd, Julia. "Magnetic Mineralogy of Nb-bearing Carbonatites from Oldoinyo Dili (Tanzania)." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-445837.

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Niobium (Nb) and Rare Earth Elements (REE’s) have in recent years received considerable attention because of their importance to the modern technical industry, and more specifically the enhanced sustainability that comes with them. The main source for Nb and REE’s on Earth are carbonatites and associated alkaline silicate rocks. This report examines the magnetic properties of rocks from the Oldoinyo Dili carbonatite complex in northern Tanzania. Previous workers have suggested a link between the Fe-bearing mineralogy and the formation of Nb-mineralizations at Oldoinyo Dili. This hypothesis is further examined in this report by combining detailed petrographic observations and withnew measurements of magnetic susceptibility. The aim is to see if any correlation exists between occurrence of Nb-mineralizations and the types of Fe-minerals present at Oldoinyo Dili. Based on the magnetic susceptibility measurements, at least two different species of Fe-minerals arefound in the examined samples. These are characterized by different magnetic trends during heating/cooling and also by their separate Curie temperatures (Tc). In combination with the petrographic observations these minerals are interpreted to be magnetite (Fe2O4) with Tc ~580°C, and a mineral that most likely represents a solid solution between ilmenite (FeTiO3) and hematite (Fe2O3) with Tc ~300°C. Here, no clear link between the type of opaque mineral(s) present and the total Nb content of the carbonatites can be conclusively determined based on the petrography and the magnetic measurements alone. Although the results of this report provide an important first step towards understanding the relationship between Nb-mineralizations and the magnetic mineralogy at Oldoinyo Dili, more detailed analyses of the mineral chemistry is a necessity to fully understand their complex relations and the specific conditions under which they formed.<br>Niob (Nb) och sällsynta jordartsmetaller (REE’s) har på senare år fått stor uppmärksamhet för sin betydelse för den moderna tekniska industrin, och specifikt för den förhöjda hållbarhet som de bidrar med. Den huvudsakliga källan till Nb och REE’s på jorden är karbonatiter och associerade alkalisilikater. Denna rapport undersöker de magnetiska egenskaperna för karbonatit-komplexet Oldoinyo Dili i norra Tanzania. Forskare har tidigare anat att det finns en koppling mellan Fe-bärande mineralogi och bildandet av Nb-mineraliseringar vid Oldoinyo Dili. Denna hypotes undersöks vidare i denna rapport genom att kombinera detaljerade petrografiska observationer med nya mätningar av magnetisk susceptibilitet. Syftet är att undersöka om det finns någon korrelation mellan förekomst av Nb-mineraliseringar och de typer av järnmineral som finns vid Oldoinyo Dili. Baserat på de genomförda magnetiska susceptibilitets-mätningarna så finns det åtminstone två olika sorters järnmineral i de undersökta proverna. De karaktäriseras av olika magnetiska trender vid upphettning/nedkylning och även av sina olika Curietemperaturer (Tc). Kombinerat med petrografiska observationer uttolkas att dessa mineral är magnetit (Fe2O4) med Tc ~580°C, samt en mineral som troligen är en solid solution av ilmenit (FeTiO3) och hematit (Fe2O3) med Tc ~300°C. Det går inte att senågon tydlig koppling mellan förekommande opaka mineral och det totala Nb-innehållet i karbonatiterna med säkerhet enbart utifrån petrografin och de genomförda magnetiska mätningarna. Resultaten av denna rapport utgör ett bra första steg mot att förstå relationen mellan Nb-mineraliseringar och den magnetiska mineralogin för Oldoinyo Dili, men mer detaljerade analyser av mineralkemin är nödvändigt för att till fullo förstå de komplexa förhållanden som råder vid bildning av dessa.
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33

Kumar, Golden. "Structural and magnetic characterization of Nd-based Nd-Fe and Nd-Fe-Co-Al metastable alloys." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2005. http://nbn-resolving.de/urn:nbn:de:swb:14-1118153436094-69139.

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The aim of the present work is to characterize a metastable hard magnetic phase referred to as &amp;quot;A1&amp;quot; in Nd-Fe alloys, which forms as a part of the fine eutectic depending on the composition and cooling rate. In order to define the range of composition for the formation of A1, Nd100-xFex (x = 20, 25, 40) alloys are cooled at about 150 K/s. The results indicate that for a cooling rate of 150 K/s, the hypereutectic Nd100-xFex (x = 20) alloys solidify into hard magnetic A1 whilst the hypoeutectic alloys (x = 40) show the formation of Nd2Fe17 crystallites. However, no sample cooled at 150 K/s shows the peaks of Nd5Fe17 as expected from the equilibrium Nd-Fe phase diagram. The effect of cooling rate on the formation of hard magnetic A1 is studied by investigating the Nd80Fe20 alloys cooled at different rates. The microstructure of hard magnetic Nd80Fe20 alloys displays a fine eutectic-like matrix consisting of Nd-richer and Fe-richer regions. The Nd-richer regions are identified as dhcp Nd and fcc Nd-Fe solid solution. However, the Fe-richer regions also referred to as A1, are diffuse and give an average composition of Nd56Fe44. These regions yield complex electron diffraction patterns, which do not match with any known Nd-Fe phase. HRTEM images of the Fe-richer regions reveal the presence of 5-10 nm crystallites embedded in an amorphous phase. Thus the Fe-richer regions of the hard magnetic Nd80Fe20 specimens are not a single homogeneous phase rather they are mixture of finely dispersed nanocrystallites in an amorphous phase. The demagnetization curves the hard magnetic Nd80Fe20 measured at temperatures above 30 K are typical of a hard magnetic material. The coercivity increases from 0.48 to 4.4 T with the temperature decreasing from 300 to 55 K. The demagnetization curves change from single to two-phase type when the temperature approaches 29 K, ordering temperature of fcc Nd-Fe solid solution. The measurements of initial magnetization, field dependence of coercivity, and temperature dependence of coercivity suggest the Stoner-Wohlfarth type magnetization reversal process for the hard magnetic A1. The values of anisotropy constant are estimated by fitting the magnetization data to the law-of-approach to saturation. The temperature dependence of anisotropy constant and the coercivity indicate that the origin of coercivity is magnetic anisotropy. A cluster model with sperimagnetic arrangement of Nd and Fe spins is used to explain the hard magnetic behavior of the mold-cast Nd80Fe20. Structural and magnetic properties of multicomponent Nd60Co30-xFexAl10 (0 &amp;lt; x &amp;lt; 30) alloys are compared with the binary Nd-Fe alloys. Magnetic measurements of the multicomponent alloys show that the magnetic properties are controlled by the fraction of the Fe content. The coercivity of the Nd60Co30-xFexAl10 mold-cast rods does not vary much with the Fe-content for more than 10 at.% Fe but the remanence and the maximum magnetization increase linearly with the Fe content. The temperature dependence of coercivity, effective anisotropy constant, and anisotropy field are identical to those for the binary Nd80Fe20 mold-cast rod. These results clearly suggest that the binary Nd80Fe20 and the multicomponent Nd60Co30-xFexAl10 (x &amp;gt; 5) mold-cast rods are magnetically identical.
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34

Schnell, Bernd [Verfasser]. "Einfluß von Kupfer- und Niob-Zusatz auf die Phasenbildung und die magnetischen Eigenschaften von rascherstarrten und wärmebehandelten TM-Silicium-Bor- und TM-Zirconium-Bor-Legierungen mit TM = Eisen, Kobalt und Nickel / Bernd Schnell." Aachen : Shaker, 2007. http://d-nb.info/1164339303/34.

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35

Kumar, Golden. "Structural and magnetic characterization of Nd-based Nd-Fe and Nd-Fe-Co-Al metastable alloys." Doctoral thesis, Technische Universität Dresden, 2004. https://tud.qucosa.de/id/qucosa%3A24505.

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The aim of the present work is to characterize a metastable hard magnetic phase referred to as &amp;quot;A1&amp;quot; in Nd-Fe alloys, which forms as a part of the fine eutectic depending on the composition and cooling rate. In order to define the range of composition for the formation of A1, Nd100-xFex (x = 20, 25, 40) alloys are cooled at about 150 K/s. The results indicate that for a cooling rate of 150 K/s, the hypereutectic Nd100-xFex (x = 20) alloys solidify into hard magnetic A1 whilst the hypoeutectic alloys (x = 40) show the formation of Nd2Fe17 crystallites. However, no sample cooled at 150 K/s shows the peaks of Nd5Fe17 as expected from the equilibrium Nd-Fe phase diagram. The effect of cooling rate on the formation of hard magnetic A1 is studied by investigating the Nd80Fe20 alloys cooled at different rates. The microstructure of hard magnetic Nd80Fe20 alloys displays a fine eutectic-like matrix consisting of Nd-richer and Fe-richer regions. The Nd-richer regions are identified as dhcp Nd and fcc Nd-Fe solid solution. However, the Fe-richer regions also referred to as A1, are diffuse and give an average composition of Nd56Fe44. These regions yield complex electron diffraction patterns, which do not match with any known Nd-Fe phase. HRTEM images of the Fe-richer regions reveal the presence of 5-10 nm crystallites embedded in an amorphous phase. Thus the Fe-richer regions of the hard magnetic Nd80Fe20 specimens are not a single homogeneous phase rather they are mixture of finely dispersed nanocrystallites in an amorphous phase. The demagnetization curves the hard magnetic Nd80Fe20 measured at temperatures above 30 K are typical of a hard magnetic material. The coercivity increases from 0.48 to 4.4 T with the temperature decreasing from 300 to 55 K. The demagnetization curves change from single to two-phase type when the temperature approaches 29 K, ordering temperature of fcc Nd-Fe solid solution. The measurements of initial magnetization, field dependence of coercivity, and temperature dependence of coercivity suggest the Stoner-Wohlfarth type magnetization reversal process for the hard magnetic A1. The values of anisotropy constant are estimated by fitting the magnetization data to the law-of-approach to saturation. The temperature dependence of anisotropy constant and the coercivity indicate that the origin of coercivity is magnetic anisotropy. A cluster model with sperimagnetic arrangement of Nd and Fe spins is used to explain the hard magnetic behavior of the mold-cast Nd80Fe20. Structural and magnetic properties of multicomponent Nd60Co30-xFexAl10 (0 &amp;lt; x &amp;lt; 30) alloys are compared with the binary Nd-Fe alloys. Magnetic measurements of the multicomponent alloys show that the magnetic properties are controlled by the fraction of the Fe content. The coercivity of the Nd60Co30-xFexAl10 mold-cast rods does not vary much with the Fe-content for more than 10 at.% Fe but the remanence and the maximum magnetization increase linearly with the Fe content. The temperature dependence of coercivity, effective anisotropy constant, and anisotropy field are identical to those for the binary Nd80Fe20 mold-cast rod. These results clearly suggest that the binary Nd80Fe20 and the multicomponent Nd60Co30-xFexAl10 (x &amp;gt; 5) mold-cast rods are magnetically identical.
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Bocharova, Ekaterina. "Mechanisch legierte hochfeste nanokristalline Cu-Nb-Leitermaterialien." Doctoral thesis, [S.l.] : [s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=976787628.

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Gevorkyan, Jirair. "Biochemical Characterization of the NifB Enzyme and NifB-cofactor." Doctoral diss., University of Central Florida, 2013. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5634.

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The Mo-nitrogenase complex is composed of two components, Fe-protein and MoFe-protein. This complex is able to catalyze the reduction of N2 through the MgATP dependent transfer of electrons from the Fe-protein Fe4S4 cluster to the MoFe-protein P-cluster and, subsequently, to the iron-molybdenum cofactor (FeMo-co). FeMo-co is a Fe7S9MoC-(R)-homocitrate cluster and has two biosynthetic precursors, NifB-co and L-cluster, of unknown structure and composition. The biosynthesis of FeMo-co is an enigmatic process that minimally requires NifB, NifEN, Fe-protein, MoO42-, (R)-homocitrate and S-adenolsylmethionine. A means to isolate the NifB enzyme for characterization has been developed through use of a GST-fusion tag. Double recombination of A. vinelandii strains with a constructed vector has yielded strains capable of nif promoter regulated expression of GST-NifB. Extracts of strains containing GST-NifB were shown to activate the Mo-nitrogenase complex in biochemical complementation assays. Mass spectroscopy was then used to verify successful isolation of GST-NifB by GSH-Sepharose affinity purification. The number of NifB-co ligand binding sites and ligand types were examined by EXAFS analysis of samples containing selenol and thiol ligands. A Fe6S9C model for NifB-co was optimized to best fit the EXAFS data, where a 2-fold discrepancy in binding sites implied by thiol or selenol only ligand samples suggests Fe-(?2S)-Fe binding in the absence of Se. Samples containing heterogeneous ligand types indicated that NifX bound NifB-co ligates to four cysteine residues and one molecule of DTT.<br>Ph.D.<br>Doctorate<br>Chemistry<br>Sciences<br>Chemistry
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Bengone, Olivier. "Étude des propriétés électroniques et structurales de NiO massif et des surfaces NiO(001) et NiO(111)." Metz, 2000. http://docnum.univ-lorraine.fr/public/UPV-M/Theses/2000/Bengone.Olivier.SMZ0043.pdf.

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Dans ce travail, nous avons étudié la structure électronique de l'oxyde de nickel massif, ainsi que les effets de reconstruction structurale des surfaces NiO(001) et NiO(111) terminée par un plan d'atomes d'oxygène. Pour se faire, nous avons utilise la méthode des ondes planes augmentées par projection (PAW), qui permet de déterminer la configuration géométrique et électronique de l'état fondamental grâce au concept de minimisation globale de la fonctionnelle énergie totale, développé par Car-Parrinello. Afin de tenir compte des effets de corrélation pour les électrons d, qui jouent un rôle prépondérant dans les propriétés électroniques de NiO, nous avons implémenté une correction de Hubbard multi-orbitales (LDA + U). Ceci nous a permis de reproduire correctement l'état fondamental antiferromagnétique isolant, ainsi que les propriétés optiques de NiO massif. Nous avons égalemment appliqué cette méthode aux surfaces NiO(001) et NiO(111). Les effets de reconstruction et les modifications de la structure électronique de la surface (001) de NiO comparé au volume restent faibles. En revanche, la surface polaire (111) en reconstruction octopolaire p(22) terminée par un plan d'atomes d'oxygène présente de profondes modifications dans la structure électronique ainsi que de relaxation atomiques.
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Barksten, Kajsa, and Louise Hansson. "Humankapital i årsredovisningar : -skillnaden mellan nio kunskaps- och nio industriföretag." Thesis, Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-33345.

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Humankapital har ökat i betydelse då allt fler företag har blivit så kallade kunskapsföretag, vilka inriktar sig på att skapa värde genom att endast erbjuda personalens kunskap, kompetens och erfarenhet. Humankapitalet menar forskare, är en tillgång för företaget och borde därför också redovisas som en sådan, precis som företagets andra tillgångar. Dock får inte humankapital i dagens läge tas upp som en tillgång i den finansiella rapporten. Det redovisas därför ofta frivilligt av företagen i hållbarhetsredovisningar. Kunskapsföretagen borde enligt forskare vara de som redovisar absolut mest information om sitt humankapital, då det är företags viktigaste tillgång. Forskare menar också att företagens storlek är en faktor som påverkar hur mycket humankapital som redovisas. Är detta verkligheten? Syftet med denna uppsats är att undersöka om det finns några skillnader i hur kunskapsföretag och industriföretag redovisar sitt humankapital i sin årsredovisning samt om företagets storlek påverkar mängden humankapital som återfinns i företagens årsredovisningar. Metoden som används var en kvalitativ dokumentundersökning. I empiri och analys kapitlet finns företagssammanfattningar och vad Scoreboarden gav för resultat. Resultatet redovisas utefter Scoreboardens olika kategorier: anställda, anställdas utbildning, anställdas välmående och motivation, övrig kvalitativ information, styrelse och ledning. Resultatet analyseras också utefter kategori för att underlätta överskådligheten och analysen. Vi delar sedan upp Scoreboarden i två övergripande kategorier: ”Anställda” och ”Ledande befattningshavare”. En analys görs av dessa övergripande kategorier. ”Anställda” består av kategorierna: anställda, anställdas utbildning, anställdas välmående och motivation samt övrig kvalitativ information. ”Ledande befattningshavare” består av: styrelse och ledning. Sist analyseras skillnaden mellan företagens totala redovisning av humankapital. Slutsatser som kan dras utifrån undersökningen är att det finns en skillnad mellan kunskapsföretag och industriföretag om vi bryter ner informationen. Kunskapsföretagen redovisar mer information om ”Anställda”, medan industriföretagen redovisar mer om ”Ledande befattningshavare”. Studeras den totala bilden är skillnaderna mindre. Dock finner vi att industriföretagens redovisning av humankapital påverkas av företagets storlek, medan kunskapsföretaget inte uppvisar en sådan trend.<br>Human capital has become increasingly important as more companies have become so called knowledge-based enterprises, which focuses on creating value by offering their staff knowledge, skills and experience. The human capital is, according to scientists, an asset to the company and should therefore be recognized as such, just like the company's other assets. However, human capital cannot be recognized as an asset in the financial report. Firms therefore often report this information voluntarily in sustainability reports. According to researchers, the knowledge companies should be the one that presents the most information regarding its human capital, since it is such a company's most important asset. Researchers also believe that corporate size is a factor that affects how much human capital is reported. Is this reality? The purpose of this paper is to investigate whether there are any differences in how knowledge- and industry enterprises reports its human capital in its annual report, and if the company's size affects the amount of human capital that can be found in corporate annual reports. The method used was a qualitative document examination. In the empirical evidence and analysis chapter, the reader can find company summaries and the results the scoreboard gave us. The results are reported according to the Scoreboards different categories: employees, employee training, employee well-being and motivation, other qualitative information, the board and management. The results are also analyzed by category to facilitate transparency and the analysis. We then divided the scoreboard into two overall categories: "Employees" and "Senior Management". An analysis is made of these overall categories. "Employee" is composed of the categories: employees, employee training, employee well-being and motivation and other qualitative information. "Senior management" consists of: Board and management. Finally, the difference between a company's overall human capital reporting is analyzed. The conclusions that can be drawn from the survey are that there is a difference between knowledge- and industry enterprises when they are broken down by categories. Knowledge Enterprises presents more information about "Employees", while industrial companies report more about "Senior Management". Looking at the total picture, the differences are minor; however, we find that the industrial firms' reporting of human capital is influenced by firm size, while the knowledge company does not exhibit such a trend.
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40

Chowdhury, Madhumita. "NiOx Based Resistive Random Access Memories." University of Toledo / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1325535812.

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41

Mayer-Uhma, Tobias. "Von molekularen Precursoren zu Oxidphasen im System V2O5 / Nb2O5. Darstellung, Eigenschaften, katalytische Aktivität." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2004. http://nbn-resolving.de/urn:nbn:de:swb:14-1107505327269-01068.

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In this work, mixed alkoxides of general formula [V(O)Nbx(OR)(3+5x)] (R = n-C3H7 and C2H5, x = 1, 4.5 and 9) are obtained. They are used to prepare complex (V/Nb)-pentoxides. Different spectroscopic methods, for example UV/VIS, resonance raman, infrared, temperature dependant 51V NMR and two dimensional 1H or 13C NMR, are used to elucidate structural details. It can be shown that the alkoxide precursor is a mixture of monomers and dimers which exchange very quickly. 2 % [V(O)Nb(OPr)8] (Pr = propyl) exists in a 0.1 molar solution. This complex is in equilibrium with V(O)(OPr)3 and Nb(OPr)5. Nb(OPr)5 itself exchanges with [Nb(OPr)5]2. For nuclear magnetic resonance experiments the exchange has to be slowed down using low temperatures.Controlled hydrolysis at 5 °C of a mixture of V(O)(OPr)3 and [Nb(OEt)5]2 in propanol leads to a clear transparent gel. The ratio of V : Nb is 1 : 1, 1 : 4.5 or 1 : 9, and oxalic acid is used as a chelating agent. Moreover, a dried product of a frozen solution of ammonium vanadate and ammonium oxyoxalatoniobate in water is found to be an appropriate precursor for the fore-mentioned oxides. Thermal decomposition of the gels and of the freeze dried products is monitored thermoanalytically and mass spectrometrically.The compositions of the resulting phases are examined and compared with the composition obtained via conventional synthesis (sintering of powder mixtures). Phases VNbxO(2.5+2.5x) (x = 1, 4.5 and 9) are obtained through the sol-gel technique and freeze drying at distinctly lower temperatures. VNbO5 crystallizes between 400 and 650 °C and V4Nb18O55 between 550 and 750 °C. A clean, non-reduced phase, VNb9O25, crystallizes above 1100 °C in oxygen. Below this temperature, solid solutions of V2O5 in TT- or M-Nb2O5 exist. Conventionally, pure VNbO5 is not obtainable. Some sol-gel synthesized products have the advantage of a more complete phase formation. In this way, a new phase of composition VNb9O25 can be found. The phase is homöotypic to M-Nb2O5.An additional advantage of the sol-gel synthesis lies in relatively high surface areas. Adversely, carbon remaining from the alcohol groups favours the thermodynamically stable phase VNb9O25 over the phase V4Nb18O55. Consequently, the freeze drying method seems to be the best way to get metastable phases in the system V2O5/x·Nb2O5.The formation of the complex oxides is controlled through the thermodynamics at phase boundaries. Therefore, to get mixed phases, structurally similar starting materials are preferred. In other words, using V2O5 and TT-Nb2O5 as starting materials the mixed phase similar to TT-Nb2O5 can be obtained. B-Nb2O5 as precursor yields another mixed phase similar to B-Nb2O5. In this work, this effect is called the &amp;quot;structure directing effect&amp;quot;. It is explained through the consumption of free enthalpy at the phase boundaries.As an additional point, catalytic activities of the complex oxides are examined. Because of a synergism of the known good activity of V2O5 and the good selectivity of Nb2O5, a strongly enhanced activity of the mixed oxides is found. Large surface areas further improve the activity. Connections between oxygen partial pressure, band gap and catalytic activity are found. A dilution of V2O5 in Nb2O5 down to 10 mol-% also causes an enhancement of catalytic activity<br>In der Arbeit werden durch die Synthese gemischter Alkoxide der Gesamtzusammensetzung [V(O)Nbx(OR)(3+5x)] (R = n-C3H7 und C2H5, x = 1, 4,5 und 9) sowie gefriergetrockneter Pulver Ausgangssubstanzen für gemischte, komplexe Vanadium- und Nioboxide erhalten. Untersuchungen mittels UV/VIS-, Resonanz-Raman- und IR-Spektroskopie sowie temperaturabhängiger 51V- und zweidimensionaler 1H-/13C NMR-Spektroskopie zeigen, dass es sich bei der Alkoxid-Vorstufe um ein Gemisch aus monomeren und dimeren Einheiten handelt, die in schnellem Gleichgewicht miteinander stehen. So liegt [V(O)Nb(OPr)8] als Donorkomplex vor, der im Gleichgewicht mit VO(OPr)3 und Nb(OPr)5 steht. Nb(OPr)5 steht wiederum im Gleichgewicht mit [Nb(OPr)5]2. Die Bildung und der Zerfall des Donorkomplexes erfolgen bei Raumtemperatur so schnell, dass er nur durch UV/VIS- und Resonanz-Raman-Spektroskopie sichtbar wird; bei der Kernresonanzspektroskopie muss der Austausch durch tiefe Temperaturen verlangsamt werden.Mittels kontrollierter Hydrolyse einer Mischung aus VO(OPr)3 und [Nb(OEt)5]2 in Propanol mit Oxalsäure als Chelatbildner und der Verlangsamung der Kondensation über die Erniedrigung der Temperatur wird ein homogenes, transparentes Gel aus V2O5 und Nb2O5 hergestellt. Daneben wird durch eine Lösung aus Ammoniumvanadat und Ammoniumoxyoxalatoniobat ein für die Gefriertrocknung geeigneter Precursor zur Synthese der Oxidphasen gefunden. Die Zersetzung des Gels und der gefriergetrockneten Pulver werden mittels DTA, TG und Massenspektrometrie untersucht und die Phasenausbildung mit der Reaktion von konventionellen Festkörpergemengen verglichen.Die dabei entstehenden metastabilen und thermodynamisch stabilen Phasen VNbxO(2,5+2,5x) (x = 1, 4,5 und 9) sind durch das Sol-Gel-Verfahren sowie durch die Gefriertrocknung bei deutlich niedrigeren Temperaturen und mit geringerem Fremdphasenanteil als bei der konventionellen Synthese erhältlich. VNbO5 existiert bis 650 °C, V4Nb18O55 bis 750 °C, darüber wandelt sich jede Zusammensetzung in VNb9O25 bzw. in verschiedene Nb2O5-Modifikationen und V2O5 um. Die Sol-Gel-Methode liefert im Vergleich zur Gefriertrocknung bei 900-1100 °C den Vorteil der schnelleren Phasenausbildung durch die größere Homogenität der Vorstufe. So erhält man Zwischenstufen, die sonst nur mit Beimengungen zu synthetisieren sind. In diesem Zusammenhang kann erstmalig eine zu M-Nb2O5 homöotype Verbindung der Zusammensetzung VNb9O25 erhalten werden. Ein weiterer Vorteil der Sol-Gel-Synthese ist der Erhalt größerer Oberflächen nach der Zersetzung. Nachteilig erscheinen jedoch bei einer Synthese bei tiefen Temperaturen (500-800 °C) die Alkoholatreste. So entstehen wesentlich eher die thermodynamisch begünstigten Phasen, z. B. VNb9O25 vor V4Nb18O55 und V4Nb18O55 vor VNbO5. Weiterhin macht sich die komplizierte Präparation der Gele bemerkbar; daher stellt im Allgemeinen die Gefriertrockung die Methode der Wahl dar.Die Ausbildung der komplexen Oxide erfolgt stark geprägt durch die Thermodynamik an den Phasengrenzen. Daher erfolgt eine bevorzugte Ausbildung strukturähnlicher Mischphasen. Diese erstmalig in diesem Ausmaß festgestellte Tatsache wird in der Arbeit der Strukturdirigierende Effekt genannt. Eine Erklärung dieses Effektes erfolgt anhand des Verbrauchs der Freien Enthalpie an den Phasengrenzen.Aufgrund eines Synergismus der Eigenschaften von V2O5 und Nb2O5 bei der oxidativen Dehydrierung von Propan zu Propen (relativ hohe katalytische Aktivität von V2O5 und hohe Selektivität von Nb2O5) wird eine überproportional hohe katalytische Aktivität bei den Mischoxiden erhalten. Die durch die unkonventionellen Methoden erhaltenen großen Oberflächen verbessern die Aktivität weiter. Es können Zusammenhänge festgestellt werden zwischen der Sauerstoffabgabetendenz, der Redoxkraft, der Bandlücke der Mischoxide und der katalytischen Aktivität. Die Einzigartigkeit des Nb2O5-Wirtsgitters bewirkt bei der Verdünnung von V2O5 darin eine hohe katalytische Leistungssteigerung
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Galv?o, Thiago Barros. "Regula??o coordenada da mobiliza??o de lip?dios e prote?nas por horm?nios, fontes de carbono e nitrog?nio durante o crescimento p?s-germinativo em Girassol." Universidade Federal do Rio Grande do Norte, 2012. http://repositorio.ufrn.br:8080/jspui/handle/123456789/12599.

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Made available in DSpace on 2014-12-17T14:03:40Z (GMT). No. of bitstreams: 1 ThiagoBG_DISSERT.pdf: 3417310 bytes, checksum: 231528fc9635d19058afc690137548e0 (MD5) Previous issue date: 2012-10-17<br>Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior<br>The mobilization of food reserves in storage tissues and allocation of their hydrolysis products in the growing axis are critical processes for the establishment of seedlings after germination. Therefore, it is crucial for mobilization of reserves to be synchronized with the growing axis, so that photosynthetic activity can be started before depletion of reserves. For this, integrative approaches involving different reserves, different hydrolysis products and interaction between storage and growing axis tissues, either through hormones or metabolites with signaling role, can contribute greatly to the elucidation of the regulation mechanisms for reserve mobilization. In this study, was hypothesized that hormones and metabolites have different actions on reserve mobilization, and there must be a crossed effect of sugars on the mobilization of proteins and amino acids on lipids and starch mobilization in sunflower seedlings. This study was conducted with seeds of sunflower (Helianthus annuus L.) hybrid Helio 253 using in vitro culture system. Seeds were germinated on Germitest? paper and grown on agar-water 4 g/L without addition of nutrients during 9 days after imbibition (DAI) for growth curve. To verify the effect of metabolites and hormones, seedlings were transferred in the 2nd DAI to agar-water 4 g/L supplemented with increasing concentrations of sucrose or L-glutamine, abscisic acid, gibberellic acid or indolebutyric acid. The results of this study confirm that the mobilization of lipids and storage proteins occurs in a coordinated manner during post-germination growth in sunflower, corroborating the hypothesis that the application of external carbon (sucrose) and nitrogen (L-glutamine) sources can delay the mobilization of these reserves in a crossed way. Moreover, considering the changes in the patterns of reserve mobilization and partition of their products in seedlings treated with different growth regulators, it is evident that the effects of metabolites and hormones must involve, at least in part, distinct mechanisms of action<br>A mobiliza??o das reservas nutritivas nos tecidos de armazenamento e a aloca??o de seus produtos de hidr?lise no eixo em crescimento s?o processos cr?ticos para o estabelecimento das pl?ntulas ap?s a germina??o das sementes. Assim sendo, ? necess?rio que a mobiliza??o das reservas seja sincronizada com o crescimento do eixo de forma que a atividade fotossint?tica tenha iniciado antes que as reservas sejam exauridas. Para isso, abordagens integrativas envolvendo as diferentes reservas, os diferentes produtos e o interc?mbio entre os tecidos de armazenamento e o eixo em crescimento, seja por interm?dio de horm?nios ou metab?litos com papel de sinaliza??o, podem contribuir sobremaneira para o esclarecimento dos mecanismos que regulam a mobiliza??o de reservas. Neste trabalho, foram levantadas as hip?teses de que o efeito de horm?nios e de metab?litos sobre a mobiliza??o das reservas ? diferente e de que deve existir um efeito cruzado de a??cares sobre a mobiliza??o de prote?nas e de amino?cidos sobre a mobiliza??o de lip?dios e amido em pl?ntulas de girassol. O presente trabalho foi desenvolvido com sementes de girassol (Helianthus annuus L.) h?brido Helio 253, utilizando sistema in vitro de cultura. As sementes foram germinadas em papel Germitest? e crescidas em meio ?gar-?gua 4g/L sem adi??o de nutrientes durante 9 dias ap?s a embebi??o (DAE) para a curva de crescimento. Para verificar o efeito de metab?litos e horm?nios, as pl?ntulas foram transferidas ao 2o DAE para meio ?gar-?gua 4 g/L suplementado com concentra??es crescentes de sacarose ou L-glutamina, ?cido absc?sico, ?cido giber?lico ou ?cido indolbut?rico. Os resultados deste trabalho confirmam que a mobiliza??o dos lip?dios e das prote?nas de reserva ocorre de forma coordenada durante o crescimento p?s-germinativo inicial em girassol, corroborando a hip?tese de que a aplica??o externa de fontes de carbono (sacarose) e nitrog?nio (L-glutamina) ? capaz de atrasar a mobiliza??o dessas reservas nutritivas de forma cruzada. Al?m disso, considerando as mudan?as nos padr?es de mobiliza??o das reservas e a parti??o dos seus produtos, proporcionadas pela aplica??o externa de diferentes reguladores do crescimento, ? evidente que os efeitos dos metab?litos e dos horm?nios devem envolver, pelo menos em parte, mecanismos de a??o distintos
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43

Karakas, Sen Asuman. "Functional analysis of NisB in nisin biosynthesis." Thesis, University of East Anglia, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327530.

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44

Landeira, Bruna Soares. "Efeitos da elimina??o de neur?nios infragranulares sobre a especifica??o de neur?nios supragranulares do c?rtex cerebral." Universidade Federal do Rio Grande do Norte, 2012. http://repositorio.ufrn.br:8080/jspui/handle/123456789/17023.

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Made available in DSpace on 2014-12-17T15:28:51Z (GMT). No. of bitstreams: 1 BrunaSL_DISSERT.pdf: 1891001 bytes, checksum: 1d482b920c53ec1f846060dbc2158ebb (MD5) Previous issue date: 2012-08-10<br>Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior<br>The cerebral cortex of mammals is histologically organized into different layers of excitatory neurons that have distinct patterns of connections with cortical or subcortical targets. During development, these cortical layers are established through an intricate combination of neuronal specification and migration in a radial pattern known as "insideout": deep-layer neurons are generated prior to upper-layer neurons. In the last few decades, several genes encoding transcription factors involved in the sequential specification of neurons destined to different cortical layers have been identified. However, the influence of early-generated neurons in the specification of subsequent neuronal cohorts remains unclear. To investigate this possible influence, we induced the selective death of cortical neurons from layer V and VI before the generation of layer II, III and IV neurons. Thus, we can evaluate the effects of ablation of early born neurons on the phenotype of late born neurons. Our data shows that one-day after ablation, layer VI neurons expressing the transcription factor TBR1 are newly generated while virtually no neuron expressing TBR1 was generated in the same age in control animals. This suggests that progenitors involved in the generation of neurons destined for superficial layers suffer interference from the selective death of neurons in deep layers, changing their specification. We also observed that while TBR1-positive neurons are located exclusively in deep cortical layers of control animals, many TBR1-positive neurons are misplaced in superficial layers of ablated animals, suggesting that the migration of cortical neurons could be controlled independently of neuronal phenotypes. Furthermore, we observed an increase in layer V neurons expressing CTIP2 and neurons expressing SATB2 and that these cells have changed their distributions. As a conclusion, our data indicate the existence of a mechanism of control exercised by the early-generated neurons in the cerebral cortex on the fate of the progenitors involved in the generation of the following cortical neurons. This mechanism could help to control the number of neurons in different layers and contribute to the establishment of different cortical areas<br>O c?rtex cerebral de mam?feros encontra-se histologicamente organizado em camadas de neur?nios excitat?rios que, por sua vez, apresentam distintos padr?es de conectividade com alvos corticais ou sub-corticais. Durante o desenvolvimento, estas camadas corticais s?o estabelecidas atrav?s de uma intrincada combina??o entre especifica??o neuronal e migra??o radial num padr?o conhecido como "inside-out" (de dentro para fora). Desta forma, por exemplo, neur?nios infragranulares nas camadas V e VI s?o gerados anteriormente aos neur?nios granulares da camada IV, que por sua vez s?o gerados antes dos supra-granulares das camadas II e III. Na ?ltima d?cada, foram identificados diversos genes codificando fatores de transcri??o envolvidos na especifica??o sequencial de neur?nios destinados ?s diferentes camadas corticais. No entanto, ainda pouco ? sabido sobre a influ?ncia dos neur?nios gerados previamente sobre a especifica??o das coortes neuronais subsequentes. Para investigar esta poss?vel influ?ncia, n?s utilizamos um m?todo de recombina??o g?nica (sistema Cre- Lox) para induzir a morte seletiva de neur?nios das camadas corticais V e VI antes da gera??o dos neur?nios das camadas II, III e IV. Dessa forma, pudemos avaliar os efeitos da abla??o de neur?nios infragranulares sobre o fen?tipo dos neur?nios gerados em seguida. Nossos dados mostraram que, um dia ap?s a abla??o, neur?nios da camada VI expressando o fator de transcri??o TBR1 voltaram a ser gerados enquanto praticamente nenhum neur?nio expressando TBR1 foi gerado na mesma idade em animais controle. Esse dado sugere que os progenitores envolvidos na gera??o de neur?nios destinados ?s camadas superficiais sofrem interfer?ncia da morte seletiva de neur?nios de camadas profundas, mudando sua especifica??o. Uma parte dos neur?nios TBR1 se estabeleceu na camada VI e outra migrou at? as camadas II e III, indicando que o controle dos padr?es migrat?rios pode ser independente dos fen?tipos neuronais. Al?m disso, observamos que na popula??o neuronal total tamb?m ocorreu um aumento na quantidade de neur?nios de camada V expressando CTIP2 e uma altera??o na distribui??o dessas c?lulas. O mesmo foi observado para neur?nios supragranulares expressando SATB2. Em conjunto, nossos dados indicam a exist?ncia de um mecanismo de controle exercido pelos neur?nios gerados inicialmente no c?rtex cerebral sobre o destino dos progenitores envolvidos na gera??o dos demais neur?nios corticais. Tal mecanismo poderia contribuir para o controle do n?mero de neur?nios em diferentes camadas e contribuir para o estabelecimento de diferentes ?reas corticais
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45

Shang, T., Q. F. Zhan, H. L. Yang, et al. "Effect of NiO inserted layer on spin-Hall magnetoresistance in Pt/NiO/YIG heterostructures." AMER INST PHYSICS, 2016. http://hdl.handle.net/10150/621346.

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We investigate spin-current transport with an antiferromagnetic insulator NiO thin layer by means of the spin-Hall magnetoresistance (SMR) over a wide range of temperature in Pt/NiO/Y3Fe5O12 (Pt/NiO/YIG) heterostructures. The SMR signal is comparable to that without the NiO layer as long as the temperature is near or above the blocking temperature of the NiO, indicating that the magnetic fluctuation of the insulating NiO is essential for transmitting the spin current from the Pt to YIG layer. On the other hand, the SMR signal becomes negligibly small at low temperature, and both conventional anisotropic magnetoresistance and the anomalous Hall resistance are extremely small at any temperature, implying that the insertion of the NiO has completely suppressed the Pt magnetization induced by the YIG magnetic proximity effect (MPE). The dual roles of the thin NiO layer are, to suppress the magnetic interaction or MPE between Pt and YIG, and to maintain efficient spin current transmission at high temperature. Published by AIP Publishing.
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46

Jackson, Rova Felice. "Mellan aiai och aei : Tystnad i Aischylos Niobe." Thesis, Stockholms universitet, Institutionen för kultur och estetik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-166143.

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The mythic story of Niobe, who loses her children due to hubris and is eventually transformed into a crying rock on Mount Sipylos, is well known and rearticulated throughout classical Greek literature. In this master’s thesis I aim to examine fragment 154a of Aeschylus’ lost tragedy Niobe in order to show the significance of the tragic re-enactment of silence and grief. Furthermore, I argue that the fragment of Aeschylus manifests political and aesthetic aspects that enable an immersed and widened understanding of the genre. Loraux (1997/2002) and Montiglio (2000) indicate that there might be a female correlate to the epic tradition of safeguarding honour after death. As I point out in this thesis, there is a potential gap in the study of how ancient Greek literature reenacts such alternative themes and experiences of memory and oblivion. A decisive consequence of the analysis is the new understanding of a tragic hero(ine) inverting the ancient epic tradition of remembrance, glory, and immortality typically accompanying male heroes. By means of classical perspectives on grief, as well as more recent studies of acoustic aesthetics in ancient Greek culture (Nooter 2017), the thesis demonstrates how Niobe can be viewed as a prime symbol of the tragic female, whose resistance to forget resonates throughout the tragic corpus.
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47

Todero, Domingos Roberto. "Dos conv?nios da administra??o p?blica." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2006. http://tede2.pucrs.br/tede2/handle/tede/4219.

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Made available in DSpace on 2015-04-14T14:34:00Z (GMT). No. of bitstreams: 1 388693.pdf: 2056913 bytes, checksum: a0f9d9bd3f371a671ec2a712db9faf29 (MD5) Previous issue date: 2006-12-13<br>A Disserta??o estuda, sistematiza e opina em rela??o ao assunto Conv?nios da Administra??o P?blica, notadamente no Brasil. O trabalho incide sobre tema que tem sido tratado, em nossa p?tria, de forma insuficiente, limitada e fragment?ria. O estudo examina as insufici?ncias e procede ? desestrutura??o dos principais entendimentos que distinguem os pactos de car?ter convenial em rela??o aos Contratos da Administra??o e os Contratos, quais sejam, os exames a partir, nas rela??es entre os part?cipes, das dicotonomias converg?ncia-antagonismo, ocorr?ncia ou n?o de obriga??es rec?procas, exist?ncia ou n?o de acordo de vontades para a forma??o de v?nculo jur?dico e obrigacional, a ocorr?ncia ou n?o da retirada unilateral e da den?ncia, a igualdade e a paridade ou a aus?ncia das mesmas. O trabalho caracteriza os tra?os fundamentais dos Conv?nios da Administra??o P?blica, e encontra os mesmos notadamente nos seguintes elementos: exist?ncia, nas rela??es entre os part?cipes, da coopera??o, colabora??o, coordena??o, parceria, aux?lio e/ou ajuda e, ainda, aus?ncia de lucro, pre?o e/ou remunera??o; compromisso no sentido de destinar recursos, verbas e contrapartidas para a realiza??o do objeto e do ajustado; obriga??o de utilizar, gerir, gerenciar e/ou administrar os recursos, verbas e contrapartidas de forma adequada, boa, correta, econ?mica e regular; sujei??o ? fiscaliza??o, controle e presta??o de contas sobre a realiza??o do objeto, o atendimento do acordado e o respeito ao ordenamento jur?dico nacional. Igualmente, constata que mesmo os tra?os apontados que, no seu conjunto, particularizam os Conv?nios da Administra??o P?blica, n?o impedem que se verifique a exist?ncia dos referidos elementos em outros Contratos. O estudo defende que os Conv?nios da Administra??o P?blica, inclusive pelas fragilidades das concep??es anotadas e pela desestrutura??o procedida nos denominados elementos que os distinguem dos Contratos, s?o pactos que se configuram como de natureza contratual. Considera, ainda, que os ajustes de natureza convenial, pela fisionomia diferenciada dos mesmos, t?m um regime jur?dico pr?prio no ?mbito dos acordos contratuais. O trabalho trata tamb?m de alguns poucos temas que se vinculam a tem?tica Conv?nios de forma mais particularizada, quais sejam, a quest?o dos part?cipes, e, ainda, da cria??o de organiza??es para a sua gest?o, como tamb?m da licita??o e procedimentos assemelhados nos mesmos pactos
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48

Kist, Luiza Wilges. "Associa??o entre horm?nios tireoideanos e temperamento." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2009. http://tede2.pucrs.br/tede2/handle/tede/5335.

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Made available in DSpace on 2015-04-14T14:50:54Z (GMT). No. of bitstreams: 1 410542.pdf: 194355 bytes, checksum: 1ebc57398ef39f3d171e80084726ad27 (MD5) Previous issue date: 2009-03-18<br>Temperament is the automatic emotional and motivational bias, influencing mood, behavior and personality development. Thyroid dysfunction is more prevalent in patients with mood disorder and may interfere with treatment responsiveness, but the relationship between thyroid function and temperament has been less studied. Methods: 143 subjects (103 females) who completed the Combined Emotional and Affective Temperament Scale were evaluated for TSH, free T4 and free T3 levels. Results: There was a significantly higher proportion of cyclothymics than euthymics in the high TSH group (>4 mIU/L, p<0.05). Female volunteers with TSH<4 mIU/L had significantly higher scores for anxious and lower scores for irritable temperaments. Among volunteers with TSH<4 mIU/L, there was a positive correlation of free T4 with apathetic temperament score (r=0.23, p<0.01). This correlation persisted in males (r=0.33, p=0.037) and females (r=0.22, p=0=0.026) and if only volunteers with no medication at all were included (r=0.23, p=0.015, n=108). Conclusion: Thyroid hormones seem to be associated with temperament in a non-linear way. Findings in patients with mood disorders and subclinical hypothyroidism cannot be generalized to understand the physiological role of thyroid hormones on emotion and affect.<br>O temperamento ? o vi?s autom?tico no terreno das emo??es e da motiva??o, influenciando humor, comportamento e o desenvolvimento da personalidade. A disfun??o da tireoide ? mais prevalente em pacientes com transtorno de humor e pode interferir na resposta ao tratamento. No entanto, a rela??o entre a fun??o da tireoide e o temperamento tem sido pouco estudada. M?todos: 143 sujeitos (103 mulheres) preencheram a Escala de Temperamento Afetivo e Emocional (ETAFE) e foram avaliados os n?veis s?ricos de TSH, T4 livre e T3 livre. Resultados: Houve uma propor??o significativamente maior de ciclot?micos do que eut?micos no grupo com TSH elevado (>4 mIU/L, p<0.05). Mulheres com TSH<4 mIU/L tiveram escores significativamente maiores de temperamento ansioso e menores de temperamento irrit?vel. Entre volunt?rios com TSH<4 mIU/L, houve uma correla??o positiva de T4 livre com escores de temperamento ap?tico (r=0.23, p<0.01). Esta correla??o persistiu em homens (r=0.33, p=0.037) e em mulheres (r=0.22, p=0=0.026) e na an?lise incluindo somente volunt?rios sem qualquer medica??o (r=0.23, p=0.015, n=108). Conclus?o: Os horm?nios tireoideanos parecem estar associados com o temperamento de modo n?o linear. Achados em pacientes com transtornos de humor e hipotireoidismo subcl?nico n?o podem ser generalizados para o entendimento do papel fisiol?gico dos horm?nios tireoideanos nos temperamentos afetivos e emocionais
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49

Abuetwirat, Inas Faisel. "Dielektrické vlastnosti tenkých vrstev oxidů niobu a tantalu." Doctoral thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2014. http://www.nusl.cz/ntk/nusl-233619.

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Dielektrická relaxační spektroskopie je jednou z užitečných metod pro studium molekulární dynamiky materiálů. Díky nedávnému pokroku v přístrojové a měřicí technice je dnes možné získat dielektrické spektrum v širokém frekvenčním intervalu a pro velice rozdílné materiály. Cílem mé práce bylo studium dielektrických relaxačních spekter a vodivosti oxidů titanu, niobu, tantalu, lanthanu a hafnia pro katody pracující na principu studené emise. Cílem výzkumu bylo analyzovat frekvenční a teplotní chování těchto oxidů, včetně jejich vodivosti, v širokém frekvenčním a teplotním rozsahu, a pokusit se stanovit původ relaxačního mechanismu. Vzhledem k tomu, že původně zadaný rozsah oxidů byl dosti široký, soustředila se pozornost pouze na oxidy tantalu a niobu, rovněž s ohledem na jejich aplikace v elektrolytických kondenzátorech. Elektrické, tepelné a mechanické (při zpracování) vlastnosti oxidů tantalu a niobu jsou dnes již dobře prozkoumány. K dispozici je však jen málo poznatků o jejich dielektrických relaxačních mechanismech. Výsledky získané pro Ta2O5 ukazují existence relaxačního maxima, nacházejícího se v experimentálně dostupném teplotním a frekvenčním intervalu 187 K – 385 K a 1 Hz – 10 MHz. Frekvence ztrátového maxima se řídí Arrheniovým zákonem s aktivační energií 0.048 eV. Ve vodivostních spektrech vykazují tenké vrstvy Ta2O5 na nízkých frekvencích ustálenou hodnotu a při vysokých frekvencích monotónní nárůst, který závisí na teplotě. Pozorovanou vodivost lze popsat mocninnou funkcí s exponentem nepatrně větším než jedna (tzv. superlineární závislost). Výsledky získané pro Nb2O5 v podobné teplotní a frekvenční oblasti, 218 K – 373 K, 1 Hz – 1 MHz rovněž ukazují jedno relaxační maximum. Frekvence ztrátového maxima se opět řídí Arrheniovým zákonem s poněkud vyšší aktivační energií 0.055 eV. Niobové kondenzátory vykazují vodivostní mechanismus shodný s kondenzátory tantalovými.
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50

Ren, Xinguo. "LDA + DMFT investigation of NiO." [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=979470986.

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