Teses / dissertações sobre o tema "H-111"
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1
Yanagita, Hiroshi. "Adsorbed states of H on Ni(111) and Rh(111) surfaces". 京都大学 (Kyoto University), 2000. http://hdl.handle.net/2433/181137.
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2
Gorgoi, Mihaela. "Electronic Properties of Phthalocyanines Deposited on H-Si(111)". Doctoral thesis, Universitätsbibliothek Chemnitz, 2007. http://nbn-resolving.de/urn:nbn:de:swb:ch1-200700213.
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Im Rahmen dieser Arbeit wurden vier Phthalocyanine untersucht: Metallfreies-Phthalocyanin (H2Pc), Kupferphthalocyanin (CuPc) und Fluor-substituiertes Phthalocyanin (F4CuPc und F16CuPc). Das Ziel dieser Arbeit ist die Charakterisierung der elektronischen und chemischen Eigenschaften der Grenzflächen zwischen diesen Molekülen und Silizium. Die Moleküle wurden durch organische Molekularstrahldeposition (OMBD) im Ultrahochvakuum auf wasserstoffpassivierte Si(111)-Substrate aufgedampft. Oberflächensensitive Messmethoden wie Photoemissionsspektroskopie (PES), Bremsstrahlung Isochromaten Spektroskopie (BIS oder IPES - Inverse Photoemissionsspektroskopie) und Spektroskopie der Röntgen-Absorptions-Feinstruktur (NEXAFS – Near Edge X-Ray Absorption Fine Structure) wurden zur Charakterisierung eingesetzt. Um eine Zuordnung der verschiedenen Komponenten in PES und IPES zu ermöglichen, wurden Methoden der Dichtefunktionaltheorie zur theoretischen Berechnung eingesetzt. Die Energieniveauanpassung an der Grenzfläche zwischen der organischen Schicht und der H-Si-Grenzfläche, sowie die Transportbandlücke von H2Pc, CuPc, F4CuPc und F16CuPc wurden mit Hilfe von PES und IPES bestimmt. Die NEXAFS-Messungen ermöglichten eine genaue Bestimmung der Molekülorientierung relativ zum Substrat. Die Auswertung der Daten zeigte unterschiedliche Molekülorientierungen in dünnen und dicken Filmen. Diese Änderungen wurden mit dem bandverbiegungsähnlichen Verlauf der HOMO-und LUMO-Positionen in Verbindung gebracht. Zusätzlich zu diesem Verhalten wiesen die Grenzflächen auch einen Grenzflächendipol auf, welcher durch die unterschiedlichen Austrittsarbeiten der Kontaktmaterialien hervorgerufen wird. Der Einfluss des Grads der Flouridierung wird durch eine ähnlichen Zunahme der Elektronenaffinität (EA), der Austrittsarbeit (WF) und der Ionisierungsenergie (IE) bestätigt. Die elektronischen Eigenschaften von Metall/organische-Schicht-Grenzflächen und von organischen Schichten unter Sauerstoffeinfluss wurden mit Hilfe von PES und IPES untersucht. Die Ag/Pc Grenzflächen zeigten eine Mischung aus HOMO-LUMO-Verschiebungen und Grenzflächendipolbildung. An den Ag/H2Pc- und Ag/F16CuPc- Grenzflächen wurde ein Ladungstransferkomplex gebildet. Auf der CuPc-Schicht physisorbiert das Ag lediglich und im Fall von F4CuPc wird Ladung zu Ag transferiert, wobei eine andauernde n-Typ-Dotierung an der Grenzfläche erzeugt wird. In Analogie zum Fall der Pc/H-Si Grenzfläche wiesen die Dipole, die hier gefunden wurden, eine lineare Abhängigkeit von EA, WF und IE auf und können durch die Differenz zwischen den Austrittsarbeiten vorausgesagt werden. Das Verhalten der dicken organischen Schichten unter Sauerstoffeinfluss kann in zwei Gruppen eingeteilt werden. Eine Gruppe, bestehend aus H2Pc und F4CuPc, wies nur schwache Wechselwirkung auf und der Sauerstoff physisorbiert auf der Pc-Schicht. Die beiden anderen Moleküle, CuPc und F16CuPc konnten einer Gruppe starker Wechselwirkung zugeordnet werden. CuPc bildet einen Ladungstransferkomplex mit Sauerstoff und auf F16CuPc wird eine polarisierte Schicht gebildetIn the context of this work four Phthalocyanine were studied: Metal-free Phthalocyanine (H2Pc), Copper Phthalocyanine (CuPc) and fluorine-substituted Phthalocyanine (F4CuPc and F16CuPc). The goal of this work is the electronic and chemical characteristics of the interfaces. The molecules were deposited by organic molecular beam deposition (OMBD) in the ultra high vacuum on hydrogen-passivated Si(111)-Substrate. Surface sensitive techniques such as photoemission spectroscopy (PES), bremsstrahlung isochromate spectroscopy (BIS or IPES - inverse photoemission spectroscopy) and near edge X-ray absorption fine structure spectroscopy (NEXAFS) were used for characterisation. Theoretical computations by density functional theory methods were employed, in order to assign different components in PES and IPES. The energy level alignment at the organic/H-Si interface, as well as the transport gap of H2Pc, CuPc, F4CuPc and F16CuPc were determined by PES and IPES. The NEXAFS measurements determine the exact molecular orientation with respect to the substrate. The evaluation of the data showed different molecular orientation in the thin and thick films. This change was correlated with the band bending like behaviours that emerged at these interfaces. In addition to the band bending like behaviour, the interfaces show also an interface dipole which is driven by the work function difference between the contact materials. The influence of the degree of fluorination is confirmed in the similar increase of the EA, WF and IE. The electronic properties of metal/organic layer interfaces and of organic layer under oxygen influence were examined by PES and IPES. The Ag/Pc interfaces show a mixture of HOMO-LUMO shifts and interface dipole formation. A charge transfer complex is formed in the case of Ag/H2Pc and Ag/F16CuPc interfaces. Ag is physisorbed atop the CuPc. Charge transfers from F4CuPc to Ag creating a continuous n-type doping at the interface. Similar to the Pc/H-Si interfaces the interface dipoles found here show a linear dependence on the EA, WF and IE and can be predicted by the difference in the work functions. The data evaluation of oxygen exposed thick films determined two groups of behaviours. The weak interaction group is represented by H2Pc and F4CuPc, Pcs on which oxygen is physisorbed. The strong interaction group contains the other two molecules CuPc and F16CuPc. CuPc forms a charge transfer complex with oxygen and on top of F16CuPc a polarized layer is formed
3
Hugelmann, Martin. "Erzeugung und Charakterisierung metallischer Nanostrukturen auf n-Si(111):H-Einkristalloberflächen". Karlsruhe : Univ.-Verl, 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=973495839.
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GUNTHER, ROLF. "Etudes des structures electroniques du si(111)-h(1x1) par photoemission angulaire". Paris 11, 1997. http://www.theses.fr/1997PA112443.
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Les etudes de photoemission fourni les resultats suivants : _ la surface si(111)-h(1x1) obtenue par voie chimique est effectivement d'une qualite esceptionelle. _ la preparation de la surface par voie chimique n'est pas completement maitrisee. Nous avons travaille sur une quarantaine d'echantillons : deux ou trois ont presente des spectres nettement superieurs aux autres. L'origine de cette difference n'est pas evidente. _ la finesse des raies a permis d'obtenir la position des etats de surfaces dans la bande de valanece ainsi que leur dispersion avec une grande precision. _ suite a ces resultats, des calculs lda et gw ont ete menes par l'equipe du professeur s. Louie a berkeley. Les calculs gw (quasi particules), montrent un accord remarquable avec nos resultats. _ les mesures sur les niveaux 2p du si a hv = 108 ev qui representent en principe le volume montrant les structures les plus fines jamais observees sur les niveaux de cur du si. Elles ont permis de montrer par ailleurs : - que la largeur a mi-hauteur de ces raies depend fortement de la preparation de la surface - que la plupart des valeurs donnees dans la litterature pour la duree de vie du trou ainsi que pour la contribution des phonons sont fausses. - que les mesures sur des surfaces differentes (si(111) hydrogene, photodesorbe, si(7x7) montrent clairement que la mesure de la duree de vie du trou par photoemission ne peut etre une technique fiable. _ les mesures de photoemission sur les niveaux de cur a hv = 130 ev (sensibilite a la surface) ont permis d'etudier les deplacements des niveaux de cur a la surface.
5
Haug, Kerstin Leigh 1971. "The unique reactions of surface bound H, bulk H, and gas phase H atoms with acetylene, ethylene and ethane on Ni(111)". Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/84737.
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Hugelmann, Martin [Verfasser]. "Erzeugung und Charakterisierung metallischer Nanostrukturen auf n-Si(111):H-Einkristalloberflächen / Martin Hugelmann". Karlsruhe : Univ.-Verl. Karlsruhe, 2004. http://d-nb.info/973495839/34.
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Razado-Colambo, Ivy. "Scanning Tunneling Microscopy and Photoelectron Spectroscopy Studies of Si(111) and Ge(111) Surfaces : Clean and Modified by H or Sn Atoms". Doctoral thesis, Linköpings universitet, Tekniska högskolan, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-17371.
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The (111) surfaces of Si and Ge were studied by scanning tunneling microscopy (STM) and photoelectron spectroscopy (PES) that are complementary techniques used to obtain structural and electronic properties of surfaces. The (111) surfaces have been of great interest because of the complex reconstructions formed by annealing. Adsorption of different types of atoms on these surfaces has been widely explored by many research groups. In this thesis work, both clean and modified Si(111) and Ge(111) surfaces were extensively studied to gain information about their atomic and electronic structures. Hydrogen plays a significant role in surface science, specifically in passivating dangling bonds of semiconductor surfaces. There has been a significant number of studies performed on hydrogen exposure of the Si(111)7x7 surface. However, most studies were done after higher exposures resulting in a 1x1 surface. In this thesis work, low hydrogen exposures were employed such that the 7x7 structure was preserved. STM images revealed that the hydrogen atoms preferentially adsorb on the rest atoms at elevated temperatures. A hydrogen terminated rest atom dangling bond is no longer visible in the STM image and the surrounding adatoms become brighter. This implies that there is a charge transfer back to the adatoms. Three types of Htermination (1H, 2H and 3H) were studied in detail by analysing the line profiles of the apparent heights. There are still unresolved issues regarding the electronic structure of the Ge(111)c(2x8) surface. By combining STM, angle-resolved photoelectron spectroscopy (ARPES), and theoretical calculations, new results about the electronic structure of the clean surface have been obtained in this thesis. A more detailed experimental surface band structure showing seven surface state bands is presented. A split surface state band in the photoemission data matched a split between two types of rest atom bands in the calculated surface band structure. A highly dispersive band close to the Fermi level was identified with states below the adatom and rest atom layers and is therefore not a pure surface state. The bias dependent STM images which support the photoemission results were in agreement with simulated images generated from the calculated electronic structure of the c(2x8) surface. Many studies have been devoted to hydrogen adsorption on Si(111)7x7 but only a few have dealt with Ge(111)c(2x8). In this work, hydrogen adsorption on Ge(111)c(2x8) has been studied using STM and ARPES. The preferred adsorption site is the rest atom. As a consequence of the adsorption on the rest atom there is a reverse charge transfer to the adatoms, which makes them appear brighter in the filled-state STM images. Photoemission results showed that for the H-exposed surface, the surface states associated with the rest-atom dangling bonds decreased in intensity while a new peak appeared in the close vicinity of the Fermi level which is not present in the spectrum of the clean surface. This is a clear evidence of a semiconducting to metallic transition of the Ge(111)c(2x8) surface. A higher H exposure on the Ge(111)c(2x8) surface was also done which resulted in a 1x1 surface. The electronic structure was investigated using ARPES. Two surface states were observed that are related to the Ge-Ge backbonds and the Ge-H bonds. Sn/Ge(111) has attracted a lot of attention from the surface science community because of the interesting phase transition from the RT-(√3x√3) phase to the LT-(3x3) phase. Previously, the Sn/Ge(111)√3x√3 surface was considered to be just a simple α- phase surface on which the Sn atoms sit on the T4 sites. However, a core-level study of the RT-(√3x√3) surface showed two components in the Sn 4d core-level spectra which implies that there are two inequivalent Sn atoms. The transition was later on explained by the dynamical fluctuation model. There have been different models proposed for the Sn/Ge(111)3x3 structure such as the 2U1D, 1U2D and IDA models. In this thesis work, the surface was studied using STM. The optimum √3x√3 surface was determined by performing different sample preparations. The LT STM images of the 3x3 surface were investigated and they showed that there are different types of Sn atoms such as up and down atoms. A histogram of the apparent height distribution revealed two peaks, a sharper peak associated with the up atoms and a broader peak for the down atoms. The height distribution was used to produce simulated Sn 4d core-level spectra and the line shape was compared to that of experimental spectra.
8
Zahl, Percy. "Oberflächenspannung auf Si(111): Heteroepitaxie von Ge und CaF2, Adsorption von H und Sb". [S.l. : s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=961158336.
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Zheng, Chaozhi. "Coverage, step and quantum effects on surface diffusion of H on Pt(111) surfaces /". View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?PHYS%202004%20ZHENG.
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Wickard, Todd DeVere. "The First Attachment and Post-Functionalization of Polybutadiene and Thio-Click Functionalized Polybutadiene on H-Terminated Si(111)". BYU ScholarsArchive, 2009. https://scholarsarchive.byu.edu/etd/2035.
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I report the attachment of polymers with pendant vinyl groups to hydrogen-terminated silicon(111) (Si(111)-H) under mild conditions. 1,2-addition polybutadiene (Mw 3200-3500) was attached to Si(111)-H at room temperature with visible light. I also report the partial functionalization, in solution, of 1,2-addition polybutadiene with various thiols using thiol-click chemistry. These compounds bind to Si(111)-H via visible light activation. The partially functionalized polybutadienes allow further functionalization at the surface through unreacted carbon-carbon double bonds. Surfaces were characterized with contact angle goniometry, spectroscopic ellipsometry, X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS), and atomic force microscopy (AFM).
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Sauter, Markus [Verfasser], e H. von [Akademischer Betreuer] Löhneysen. "Untersuchungen eindimensionaler Strukturen auf vizinalen Si(111):Au-Oberflächen mit Rastertunnelmikroskopie und -spektroskopie / Markus Sauter. Betreuer: H. von Löhneysen". Karlsruhe : KIT-Bibliothek, 2009. http://d-nb.info/1014221889/34.
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Thiele, Cornelius [Verfasser], e H. von [Akademischer Betreuer] Löhneysen. "STM Characterization of Phenylene-Ethynylene Oligomers on Au(111) and their Integration into Carbon Nanotube Nanogaps / Cornelius Thiele. Betreuer: H. von Löhneysen". Karlsruhe : KIT-Bibliothek, 2014. http://d-nb.info/1052933467/34.
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Laliberté, Marc-André. "Études de la réactivité du Pt(111) et de la liaison C-H---O=C : Applications en catalyse hétérogène et assemblage moléculaire". Thesis, Université Laval, 2009. http://www.theses.ulaval.ca/2009/26253/26253.pdf.
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Chuang, Tzu-Hung [Verfasser], J. [Akademischer Betreuer] Kirschner, G. [Akademischer Betreuer] Schmidt e H. [Akademischer Betreuer] Wende. "High wave-vector magnon excitations in ultrathin Fe(111) films grown on Au/W(110) and Fe(001) films grown on Ir(001) / Tzu-Hung Chuang. Betreuer: J. Kirschner ; G. Schmidt ; H. Wende". Halle, Saale : Universitäts- und Landesbibliothek Sachsen-Anhalt, 2013. http://d-nb.info/1033306665/34.
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Rouissi, Zied [Verfasser], Dieter [Akademischer Betreuer] Schmeißer, Ehrenfried [Akademischer Betreuer] Zschech e Christian [Akademischer Betreuer] Pettenkofer. "Role of substrates morphology and chemistry in ALD HfO₂ on Si(111)-H terminated surfaces as model / Zied Rouissi ; Dieter Schmeißer, Ehrenfried Zschech, Christian Pettenkofer". Cottbus : BTU Cottbus - Senftenberg, 2017. http://d-nb.info/1136904441/34.
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Musgrave, Charles Bruce Goddard William A. Goddard William A. "Molecular mechanics and ab initio simulations of silicon (111) surface reconstructions, semiconductors and semiconductor superlattices, H abstraction for nanotechnology, polysilane, and growth of CVD diamond /". Diss., Pasadena, Calif. : California Institute of Technology, 1995. http://resolver.caltech.edu/CaltechETD:etd-10192007-104223.
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Graubner, Sebastian [Verfasser], H. [Gutachter] Riess, P. [Gutachter] Wust e W. [Gutachter] Fiegler. "Klinischer Verlauf und Analyse des Rezidivmusters von 111 Patienten mit anaplastischem Astrozytom oder Glioblastoma multiforme nach Operation und lokaler Strahlentherapie / Sebastian Graubner ; Gutachter: H. Riess, P. Wust, W. Fiegler". Berlin : Humboldt-Universität zu Berlin, 2005. http://d-nb.info/1207666602/34.
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Curcella, Alberto. "Looking for silicene: studies of silicon deposition on metallic and semiconductor substrates". Master's thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amslaurea.unibo.it/9314/.
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Nel presente lavoro espongo i risultati degli esperimenti svolti durante la mia internship all’Institut des NanoSciences de Paris (INSP), presso l’Università Pierre et Marie Curie (Paris VI), nel team "Phisico-Chimie et Dynamique des Surfaces", sotto la supervisione del Dott. Geoffroy Prévot. L’elaborato è stato redatto e in- tegrato sotto la guida del Dott. Pasquini, del dipartimento di Fisica e Astronomia dell’Università di Bologna. La tesi s’inserisce nel campo di ricerca del silicene, i.e. l’allotropo bidimensionale del silicio. Il cosidetto free-standing silicene è stato predetto teoricamente nel 2009 utilizzando calcoli di Density Functional Theory, e da allora ha stimolato un’intensa ricerca per la sua realizzazione sperimentale. La sua struttura elettronica lo rende particolarmente adatto per eventuali appli- cazioni tecnologiche e sperimentali, mentre lo studio delle sue proprietà è di grande interesse per la scienza di base.
Nel capitolo 1 presento innanzitutto la struttura del silicene e le proprietà previste dagli studi pubblicati nella letteratura scientifica. In seguito espongo alcuni dei risultati sperimentali ottenuti negli ultimi anni, in quanto utili per un paragone con i risultati ottenuti durante l’internship.
Nel capitolo 2 presento le tecniche sperimentali che ho utilizzato per effettuare le misure. Molto tempo è stato investito per ottenere una certa dimistichezza con gli apparati in modo da svolgere gli esperimenti in maniera autonoma.
Il capitolo 3 è dedicato alla discussione e analisi dei risultati delle misure, che sono presentati in relazione ad alcune considerazioni esposte nel primo capitolo.
Infine le conclusioni riassumono brevemente quanto ottenuto dall’analisi dati. A partire da queste considerazioni propongo alcuni esperimenti che potrebbero ulteriormente contribuire alla ricerca del silicene. I risultati ottenuti su Ag(111) sono contenuti in un articolo accettato da Physical Review B.
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Jakob, Sebastian Bernhard Ludwig [Verfasser], Werner [Akademischer Betreuer] Schindler e Katharina [Akademischer Betreuer] Krischer. "The n-Si(111):H Surface in Contact with an Aqueous Electrolyte: Surface States, Electrochemical Charge Transfer, and Nanoscale Structuring / Sebastian Bernhard Ludwig Jakob. Gutachter: Katharina Krischer ; Werner Schindler. Betreuer: Werner Schindler". München : Universitätsbibliothek der TU München, 2013. http://d-nb.info/1038787203/34.
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Janke, Svenja Maria. "Theoretical Description of Hydrogen Atom Scattering off Noble Metals". Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2016. http://hdl.handle.net/11858/00-1735-0000-0028-87A3-4.
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Scharff, Christina. "Young women's dis-identification with feminism : negotiating heteronormativity, neoliberalism and difference". Thesis, London School of Economics and Political Science (University of London), 2009. http://etheses.lse.ac.uk/111/.
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This thesis explores young women's relationship with feminism, contributing to an enhanced understanding of feminist dis-identification. Feminist research offers various explanations for young women's repudiation of feminism; this study adds a further dimension to current debates by adopting a performative approach which explores how difference, and particularly sexuality, mediates young women's responses to feminism. Employing and developing the broader theoretical frameworks of postfeminism, individualisation, neoliberalism, and difference, this thesis intervenes in current debates by highlighting the role of heteronormativity in negotiations of feminism. The study is based on forty, semi-structured qualitative in-depth interviews with a diverse group of German and British women, aged 18-35. A discursive analysis of the interviews provides an insight into young women's talk, thoughts, and feelings about feminism. Exemplifying a postfeminist logic, two broad patterns were discernable in the research participants' talk: feminism was either considered as valuable, but anachronistic and therefore irrelevant to the present, or fiercely repudiated as extreme and dogmatic. While most research participants reported they would not call themselves a feminist, their stance towards feminism shifted depending on the cultural resources they drew on to discuss feminist politics. Reflecting the broader cultural currents of neoliberalism and individualisation, the respondents frequently rejected the need for a collective movement by positioning themselves as individuals who were capable of negotiating structural constraints autonomously. The research participants were aware of persistent gender inequalities, but located them predominantly in the public sphere and/or 'other' parts of the world, claiming they had not personally experienced gender discrimination. Feminists were overwhelmingly portrayed and constructed as unfeminine, man-hating, and lesbian. Although the respondents could not name any concrete examples of feminists who corresponded to this stereotype, the construction of 'the feminist' haunted their accounts. As the performative approach illustrates, discussions of feminism gave rise to complex negotiations and performative citations of normative femininity. Performances of femininity were racialized and classed, intersecting with feminist dis-identification in multiple ways. The perception of feminism as inclusive or exclusive figured as an important theme in the interviews. This thesis adds to our understanding of feminist dis-identification by employing various theoretical tools, drawing on empirical accounts, and by revealing the structuring role of heteronormativity in negotiations of feminism.
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Rodriguez, De Rodriguez Maria Del Pilar. "Production de biodiesel ?? partir d'une huile mod??le de microalgues par voie de catalyse enzymatique h??t??rog??ne". Mémoire, Universit?? de Sherbrooke, 2014. http://savoirs.usherbrooke.ca/handle/11143/111.
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Le biodiesel, consid??r?? comme une solution pour remplacer le p??trodiesel est un sujet de recherche mondial. Un des principaux probl??mes associ??s au d??veloppement industriel du biodiesel est la source de mati??re premi??re ainsi que le proc??d?? de transformation. Ainsi, la pr??sente ??tude a pour but de trouver une source de mati??re premi??re durable pour la production industrielle de biodiesel et de d??terminer le proc??d?? de transformation de la mati??re premi??re, le plus appropri??, ainsi que les meilleures conditions op??ratoires. Durant la premi??re ??tape de ce projet, une source de mati??re premi??re durable a ??t?? s??lectionn??e : les microalgues. Le proc??d?? de transformation ??tudi?? est la transest??rification enzymatique. L???huile d???olive, huile ayant une composition en acides gras similaires ?? celle de l???huile de la microalgue Chlorella protothecoides, a ??t?? choisie pour effectuer les r??actions. Pendant la deuxi??me ??tape, le proc??d?? de standardisation de la r??action (bior??acteur de 5 mL) consistait ?? faire varier : le type de catalyseur (lipases de Candida antarctica (Novozym?? 435) et de Thermomyces lanuginosus (TL I150)), la concentration du catalyseur (7 ?? 14 % m/mhuile), la temp??rature de r??action (25 ?? 50 ??C) et le ratio molaire alcool:huile (3:1 ?? 4:1) ; la vitesse d???agitation ??tant de 150 rpm pour toutes les r??actions. Des techniques d???optimisation telle que la preincubation de l???enzyme ont ??t?? ??galement essay??es. Le rendement en esters alkyliques de la r??action de transest??rification enzymatique de l???huile en fonction du temps est la variable de contr??le pour toutes les r??actions. La standardisation des variables du proc??d?? a ??t?? faite en fonction de la r??duction du temps de r??action et du rendement en esters alkyliques. Un rendement ??lev?? en esters alkyliques de 92 % (m/m) a ??t?? obtenu sous les conditions op??ratoires suivantes : une concentration de catalyseur (TL I150) de 7 % (m/mhuile), une temp??rature de r??action de 25 ??C, un ratio molaire alcool:huile de 3:1 et un temps de r??action de 4 h ; la lipase a ??t?? preincub??e pendant 6 h avant la r??action de transest??rification. Le temps de r??action, un des param??tres importants lors du proc??d?? de standardisation des variables, a ??t?? r??duit de 24 ?? 4 h. Un autre param??tre significatif de la r??action est la temp??rature : une temp??rature de 25 ??C a ??t?? utilis??e; cette temp??rature de r??action est faible et rend le proc??d?? au niveau industriel plus attrayant.
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Ayadi, Wassef. "Implementation of an H controller for the helicopter BK 117". Düsseldorf VDI-Verl, 2008. http://d-nb.info/98864150X/04.
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Bungaro, Claudia. "Dynamical properties of clean and H-covered W(110) surfaces". Doctoral thesis, SISSA, 1995. http://hdl.handle.net/20.500.11767/3951.
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In recent years, the availability of high-resolution surface-sensitive experimental
techniques such as Helium atom scattering (HAS) and electron energy loss spectroscopy
(EELS) has opened new perspectives in the study of the dynamical properties
of solid surfaces. In particular, a great deal of experimental data are now
available on the phonon dispersions of surfaces of insulator, semiconductors, and
metals [1]. Among transition metals, the vibrational properties of the hydrogenated
W(llO) surface have attracted much attention because they display unusual and
unexpected features which are still poorly understood [2-6]. When a full monolayer
of hydrogen is adsorbed, the surface phonon spectrum undergoes a dramatic change
and an anomalous behavior appears.
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Milazzo, Rachele Maria Gabriella. "Electroless Silver Deposition on (100) and (111) Silicon Wafers, Fabrication of Nanowires and Nanopillars by Assisted Etching". Doctoral thesis, Università di Catania, 2013. http://hdl.handle.net/10761/1293.
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Le nanoscienze e i nanomateriali promettono particolari ed entusiasmanti applicazioni, grazie alla scoperta delle loro proprietà chimico fisiche sensibili alla loro dimensione.
La realizzazione di nanostrutture di silicio, la crescita di nanowires in particolare, è di rilevante importanza nel settore della microelettronica per lo studio e l applicazione degli effetti di riduzione di scala.
I processi di crescita solitamente richiedono l utilizzo di precursori pericolosi, di temperature elevate e di apparecchiature in grado di sostenere queste condizioni di crescita.
L attacco chimico assistito da metallo è stato proposto come una valida alternativa ai processi impiegati nella fabbricazione di nanofili di silicio a basso costo.
L apparato sperimentale necessario per la sua attuazione è estremamente semplice, i processi sono svolti a temperatura ambiente e la qualità dei nanofili di silicio ottenuti è elevata poiché essi derivano semplicemente dall agglomerazione di scavi generati sul substrato. Il processo richiede la deposizione di un film di metallo nobile che aumenterà localmente la velocità di ossidazione del silicio, in una soluzione ossidante. L acido fluoridrico partecipa alla reazione rimuovendo il silicio ossidato.
La tecnica è di facile realizzazione ma la comprensione di tutti i processi chimico fisici che la compongono è tutt altro che semplice e al momento non è presente un modello che riesca ad interpretare tutti i dati sperimentali presenti in letteratura.
In questo lavoro di tesi si è cercato di contribuire alla descrizione fenomenologica del processo, ponendo particolare attenzione allo step di deposizione electroless del metallo nobile realizzato tramite immersione in una soluzione contente ioni Ag+ e Acido Fluoridrico.
La generazione di nanoclusters di argento su silicio è stata investigata, nel capitolo 1, per tempi che vanno da 1s a 160s, con RBS (Rutherford Backscattering Spectroscopy), SEM (Scanning Electron Microscopy) e cross section TEM (Transmission Electron Microscopy).
Il capitolo 2 è stato dedicato alla comprensione della dipendenza del processo di deposizione dall orientazione cristallografica del substrato, studiando l evoluzione dei nanoclusters di Ag su Silicio (100) e Silicio (111) in due distinte configurazioni: singola, deponendo i due substrati in maniera separata e simultanea, tramite l utilizzo di superfici (100) e (111), ottenute sul medesimo substrato con l attacco chimico anisotropo in soluzioni alcaline.
I risultati mostrano che nel primo caso, la quantità e la morfologia dell Ag depositato dipende poco dall'orientazione cristallografica. Se le due superfici sono simultaneamente presenti e contigue sullo stesso substrato invece, si instaura un meccanismo autoselettivo per la deposizione che risulta accentuata sui piani (100). Importante è anche il contributo del trasporto di massa che accentua la deposizione sulle zone convesse di transizione tra i due piani coinvolti.
Lo studio dell attacco assistito da metallo sui campioni depositati, capitolo 3, ha messo in evidenza il ruolo svolto dalla dimensione del metallo sulla direzione di attacco. Esso risulta anisotropo al di sotto di una certa estensione e con un basso livello di interconnessione tra i clusters. L anisotropia dell attacco è eliminata quando i clusters possiedono dimensione estesa e sono totalmente interconnessi.
I risultati ottenuti sono stati applicati su un substrato di silicio con le superfici (100) e (111) di dimensioni ridotte e il meccanismo autoselettivo per la deposizione è risultato accentuato. In questa configurazione, i piani (100) che risultano essere coperti da aggregati di Ag di dimensioni estese, sono stati attaccati, sulle superfici (111) ricoperti con piccoli clusters, invece l attacco ha prodotto solo un sottile strato poroso superficiale. La struttura risultante è un insieme ordinato di Nanopillars con dimensione media di 600nm.
26
Co?lho, Maria Reis Valois. "Altera??es fisiol?gicas e metab?licas em Hyptis fruticosa Salzm. ex. Beth e Ocimum gratissimum L. sob diferentes regimes h?dricos". Universidade Estadual de Feira de Santana, 2014. http://localhost:8080/tede/handle/tede/111.
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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES
Hyptis fruticosa Salzm. Ex. Benth and Ocimum gratissimum Lindi are species from lamiaceae family of great medicinal importance, notwithstanding, they have been goals of few studies related to the cultivation techniques. Therefore, the study?s goal was to evaluate the behavior and tolerance of plants of H. fruticosa and O. gratissimum cultivated in vases submitted to different levels of evapotranspired water reposition during thirteen days (H. fruticosa) and nine days (O. gratissimum). The experiment was made in greenhouse under randomized complete block design with four treatments (100, 75, 50 and 0% of evapotranspired water reposition). It was verified that there were not any significant difference of total dry mass and leaf area among the treatments in the species H. fruticosa and O. gratissimum. Both of them presented the lowest values of relative water content, water potential, chlorophylls and carotenoids in the water reposition 0% treatment. In O. gratissimum, there was the decrease in net assimilation of carbon, stomatal conductance and transpiration with the water deficit increase, but the CO2 inside concentration was higher in the water reposition 0% treatment. The two species presented amino acid accumulation, proline, soluble proteins and soluble carbohydrate according to the water deficit increase. The essential oil content increased with the water availability increment in O. gratissimum, but it did not present the significant difference among the treatments in H. fruticosa. O. gratissimum revealed itself more sensitive and H. fruticosa more tolerant to the water deficiency.
Hyptis fruticosa Salzm. ex. Benth e Ocimum gratissimum Lindl. s?o esp?cies da fam?lia lamiaceae de grande import?ncia medicinal, no entanto, t?m sido objetos de poucos estudos relacionados ?s t?cnicas de cultivo. Assim, o objetivo deste trabalho foi avaliar o comportamento e toler?ncia de plantas de H. fruticosa e O. gratissimum cultivadas em vasos submetidas a diferentes n?veis de reposi??o de ?gua evapotranspirada durante o per?odo de treze dias (H. fruticosa) e nove dias (O. gratissimum). O experimento foi realizado em telado sob delineamento em blocos casualizados com quatro tratamentos (100, 75, 50 e 0% de reposi??o de ?gua evapotranspirada). Verificou-se que n?o houve diferen?as significativas da massa seca total e ?rea foliar entre os tratamentos nas esp?cies H. fruticosa e O. gratissimum. As duas esp?cies apresentaram os menores valores de teor relativo de ?gua, potencial h?drico, clorofilas e caroten?ides no tratamento 0% de reposi??o de ?gua. Em O. gratissimum, houve redu??o da assimila??o l?quida de carbono, condut?ncia estom?tica e transpira??o com o aumento do d?ficit h?drico, por?m a concentra??o interna de CO2 foi superior no tratamento 0% de reposi??o de ?gua. As duas esp?cies apresentaram ac?mulo de amino?cidos livres, prolina, prote?nas sol?veis e carboidratos sol?veis de acordo com o aumento do d?ficit h?drico. O teor de ?leo essencial aumentou com o incremento da disponibilidade h?drica em O. gratissimum, mas n?o apresentou diferen?a significativa entre os tratamentos em H. fruticosa. A esp?cie O. gratissimum mostrou-se mais sens?vel e H. fruticosa mais tolerante ? defici?ncia h?drica.
27
Lens, Lotte H. L. [Verfasser]. "Advanced chemical investigations of the volatile element flerovium (Fl, Z=114) / Lotte H. L. Lens". Mainz : Universitätsbibliothek Mainz, 2020. http://d-nb.info/1205842527/34.
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28
Paige, Mikell Atkin. "Modular synthesis of Annonaceous acetogenins and their activity against H-116 human solid colon tumor cells". Full text, Acrobat Reader required, 2003. http://viva.lib.virginia.edu/etd/diss/ArtsSci/Chemistry/2003/Paige/Dissertation.pdf.
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29
Tomanic, Tihomir [Verfasser], e 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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30
GOTA, SUSANA. "Developpement de la diffraction des photoelectrons a basse energie cinetique a l'aide du rayonnement synchrotron. Application a l'etude des surfaces inp(110) et h/inp(110)". Paris 6, 1993. http://www.theses.fr/1993PA066103.
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Nous avons combine la diffraction de photoelectrons a basse energie cinetique avec la photoemission angulaire excitee par rayonnement synchrotron afin de developper une nouvelle technique adaptee a l'etude des surfaces propres. Nous l'avons teste en etudiant la relaxation de la surface clivee inp(110). Le deplacement des niveaux de cur in 4d et p 2p des atomes de surface par rapport a ceux du volume nous a permis de remonter aux diagrammes de photodiffraction azimutaux respectifs de la surface et du volume. Les resultats deduits independamment a partir de chacun ces niveaux permettent de degager des conclusions analogues. On observe une forte difference de modulations entre les diagrammes de photodiffraction de surface et de volume, qui a pour origine la difference d'environnement de l'atome emetteur dans chacun des cas. Nous obtenons, apres comparaison a des calculs en diffusion simple, un angle de relaxation de 28 en bon accord avec les valeurs proposees dans la litterature. La diffusion simple est donc une bonne description du processus physique a basse energie cinetique du photoelectron. Ceci est du a l'importante contribution de la surface ou la probabilite de diffusion multiple reste faible. Nous avons ensuite etudie les changements structuraux de cette surface apres adsorption d'une faible dose d'hydrogene atomique. Les premiers resultats mettent en evidence une modification structurale de la surface qui va dans le sens d'une derelaxation du substrat
31
Stockford, Chloe Anne. "A structural analysis of H₂O on Cu{110} using a novel low flux Fibre-Optic LEED apparatus". Thesis, University of Cambridge, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609230.
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32
Kompe, Carsten. "Etude des nuages moléculaires associés aux régions H II Sharpless 135, 112, 142 et 247, régions de formation d'étoiles". Bordeaux 1, 1988. http://www.theses.fr/1988BOR10560.
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Quatre regions hii galactiques du catalogue de sharpless ont ete observees dans les raies rotationnelles de **(13)co et **(12)co (j = 1 -> 0). Leur structure spatiale, leur temperature cinetique et leur masse sont determinees et comparees aux valeurs obtenues grace aux donnees iras a 100 mu m. Des complexes de gaz ont ete mis en evidence pour lesquels les nuages moleculaires associes aux regions hii etudiees ne sont que de simples fragments
33
Kompe, Carsten. "Etude des nuages moléculaires associés aux régions H II Sharpless 135, 112, 142 et 247, régions de formation d'étoiles". Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb376147652.
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34
Helali, Zeineb. "Etude de la coadsorption de H et CO sur une série de méteaux supportés par le rutile TiO2 (110)". Paris 6, 2013. http://www.theses.fr/2013PA066089.
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Nous proposons une étude fondamentale qui vise à aider à déterminer le mécanisme le plus probable thermodynamiquement pour la réaction de Fischer- Tropsch en fonction de la nature du métal, M = K-Zn. Les résultats ont montré que les métaux interagissent plus fortement sur la surface parfaite. En outre, nous avons examiné les structures électroniques obtenues en appliquant une correction d’Hubbard. Ceci nous a permis d’avoir des états plus localisés. Cette correction n’influence pas de beaucoup la force d’interaction si la pénalité +U reste modérée. Par conséquent, nous avons conclu que l’étude énergétique qui suivra pourra raisonnablement être réalisée en PW91 et avec la surface parfaite. L’adsorption de H sur ces métaux supportés a montré qu’une interaction M-H forte nécessite au moins deux électrons disponibles au transfert. L’adsorption de CO est particulièrement plus forte pour Cr et Cu : le support permet de vider des niveaux antiliants de M et stabilise donc l’interaction. Nous avons étudié également la formation des complexe HCO et HOC qui peuvent présenter soit un début soit une fin d’une étape de la réaction de Fischer–Tropsch. Nous avons montré que la 1ère étape de cette réaction dépendait de la nature de M. Pour Sc, Ti et V, le mécanisme le plus probable est l’hydrogénation de CO en premier suivie par la dissociation de C-O. Au contraire, pour Fe, Co et Ni, ce mécanisme paraît plus difficile. Finalement, nous avons proposé une nouvelle méthodologie pour modéliser le slab deTiO2. Nous avons donc proposé un slab saturé du côté non réactif par H2O dissociée. Les résultats ont montré une nette diminution des oscillations avec une convergence plus rapideWe propose a fundamental study aimed to determine the most favorable thermodynamically first step of the Fischer-Tropsch reaction based on the nature of M =K…Zn. The results showed that M interacts more strongly with the TiO2(110) perfect surface. We have examined in detail the electronic structures by applying a Hubbard correction. This allowed us to have more localized states. This correction does not influence by much the interaction if the penalty applied remains moderate. Therefore, we concluded that the energetic study which will be conducted later will be in PW91 and using the perfect surface as a support. The H adsorption on these supported metals showed that a strong M-H interaction requires at least two electrons available for the transfer. In the case of the CO adsorption, the interaction force increased particularly for Cr and Cu : the support can empty antibonding levels of M and stabilizes the interaction. We have also studied the formation of hydrogenated complexes, HCO and HOC, which may be a beginning or an end of this catalysis. We have shown that the elementary first step depends on the nature of the metal. For Sc, Ti and V, the most likely mechanism is the hydrogenation of CO in the first place followed by the dissociation of the CO bond. On the contrary, for M = Fe- Ni, this mechanism seems to be more difficult. Finally, we proposed a new methodology to improve the modeling of TiO2 slab. We have therefore proposed a saturated slab of the unreactive side by a dissociated H2O molecule. The results showed a significant reduction of the allowing faster convergence compared to other models proposed in the literature
35
Mourad, Suleiman Ali. "Early Islam between myth and history : Al-Hasan Al-Basri (d. 110 H = 728 CE) and the formation of his legacy in classical Islamic scholarship /". Leiden : Brill, 2006. http://catalogue.bnf.fr/ark:/12148/cb40104430n.
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36
Boucherie, Joël. "Modélisation des transferts thermiques et solutaux lors de la croissance cristalline de CdTe dans te par la méthode T. H. M. Expérience AMF 117-eureca 1". Bordeaux 1, 1991. http://www.theses.fr/1991BOR10624.
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L'etude numerique des mouvements de la phase fluide et de leur interaction sur le processus de croissance de monocristaux de cdte par t. H. M. Est effectuee par une methode de volumes finis. Nous avons integre a la convection thermique l'aspect convectif d'origine solutal. Dans les conditions aux limites, deux types de frontieres actives (interfaces fluide-solide) et non-actives (parois de l'ampoule) sont integres. Apres avoir determine les grandeurs caracteristiques adimensionnelles, des resultats sont presentes en configuration simplifiee de la zone fluide delimitee par des interfaces planes et rigides dans une premiere partie et dans l'ampoule entiere dans une seconde partie. Nous mettons alors en evidence des phenomenes convectifs oscillatoires periodiques
37
Delmastro, D. "EFFECT OF THE LOSS OF RIBONUCLEASE H ACTIVITY ON GENOME INSTABILITY: FROM DNA DAMAGE TOLERANCE TO RETROTRANSPOSITION". Doctoral thesis, Università degli Studi di Milano, 2015. http://hdl.handle.net/2434/273893.
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Preserving the entire set of hereditary instructions necessary for life of every organism, genome integrity and identity maintenance is a serious concern for cells. Genomic DNA is continuously endangered by exogenous and endogenous factors and one of the most common source of genome instability was recently detected to be the misincorporation of ribonucleotides (rNTPs) during DNA synthesis. RNA is more susceptible than DNA to spontaneous hydrolysis, so the presence of rNMPs in the genome may render chromosomes more unstable. Moreover, embedded rNMPs induce replication forks stalling and alter the B-conformation of a dsDNA, resulting in replication stress. Normally, rNMPs in DNA are processed by Ribonuclease H (RNase H) enzymes, which cleave the RNA of RNA:DNA hybrids allowing the reconstruction of a dsDNA molecule. Cells lacking RNase H activity can survive thanks to the Post-Replication Repair mechanism, which includes an error free pathway, the Template Switch, and a more mutagenic pathway that relies on the ability of special enzymes to replicate across damaged DNA, the Translesion Synthesis (TLS). Here, we focus on the contribution of the three TLS Polymerases (Rev1, Pol-zeta and Pol-eta ) to genomic-rNMPs tolerance and incorporation. We previously demonstrated that Pol-zeta efficiently replicates rNMPs-containing DNA and that Rev1 plays a non-catalytic role in supporting this function (Lazzaro et al. 2012). In this study we observed that Rev1 has also a non-catalytic role in preventing Pol-eta function. Surprisingly, the polymerase activity of Pol-eta appeared to be toxic for cells where dNTP pools, necessary for replication, are downregulated by hydroxyurea (HU), and lead to cell death when the RNase H is missing. Furthermore, we provide evidence that, in our sperimental conditions, Pol-eta toxicity is due to its tendency to introduce rNMPs during the TLS when the dNTP levels are low. Our findings describe an unexpected mechanism for TLS that could be relevant to replication stress in cells defective in RNase H, including humans stricken from diseases associated with RNase H defects like the Aicardi-Goutieres Syndrome (AGS). AGS is an autoimmune disease characterized by high levels of interferon-alpha in the serum and cerebrospinal fluid. Due to the fact that identified mutations fall in genes implicated in nucleic acid metabolism or signalling, and that an emerging source of immunostimulatory nucleic acids are fragments derived from endogenous retroelements, a recent hypothesis states that the pathological immune response could be driven by aberrant accumulation of retroelements intermediates. We then decide to use S.cerevisiae as model system to investigate the role of RNase H2 in retroelements mobility and try to link it to the possible molecular origin of AGS. We found that yeast RNase H can block the retrotransposition process and, once replaced yeast enzymes with wild type or AGS mutated forms of human RNase H2, we noticed that one of the three tested mutations causes the loss of the RNase H protective function against the mutagenic potential of retroelements. Even if preliminary, these findings could guide the way to better understand the molecular causes of AGS.
38
Dersan, Duygu. "Responses To International Changes:a Neoclassical Realist Analysis Of Syrian Foreign Policy, 1990-2005". Phd thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12615043/index.pdf.
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This work aims to analyze the responses of Syria to two international changes comparatively. After the end of the Cold War, US initiated a foreign policy doctrine based on American hegemony. This policy was firstly manifested in the war on Iraq as a response to the Iraqi invasion of Kuwait on January 17, 1991. It was noteworthy to see Syria aligning with the US during the Gulf War (1990-1991), as the country had been allied against the US during the Cold War period. Syria was also the first state accepting US proposal for a peace conference known as Madrid Peace Conference. All these developments reveal that Syria had been cooperated with the US in the aftermath of the Cold War. The second international change analyzed within the framework of this study is the September 11 events. Following the September 11 attacks, the US declared a &ldquowar on terror&rdquo
to recover its superpower position and intervened in Afghanistan and then Iraq. In that process, Syria opted for countering the US and became the leading critique of the invasion of Iraq. This study examines the different responses of Syria to the end of the Cold War and the post-September 11 period through using neoclassical realism as a model.
39
Novarina, D. "MECHANISMS PRESERVING GENOME INTEGRITY IN SACCHAROMYCES CEREVISIAE". Doctoral thesis, Università degli Studi di Milano, 2013. http://hdl.handle.net/2434/215589.
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The integrity of the genome is continuously jeopardized by endogenous reactive byproducts of cellular metabolism and genotoxic insults by environmental agents, as well as by the DNA transactions (replication, transcription and recombination) required for cell survival and proliferation. Failure of the mechanisms deputed to the maintenance of genome integrity leads to genome instability, which is a hallmark of cancer and a driving force of tumorigenesis. To fully understand the mechanisms leading to genome instability and the cellular pathways counteracting them, three basic tasks must be achieved: i) identify all the genes implicated in the control of genome integrity; ii) unravel their biological role; iii) define the mechanistic molecular details of the processes in which they are implicated. This thesis describes work performed in the budding yeast Saccharomyces cerevisiae to explore the genome stability landscape at all these three levels. This model system is extremely useful for two main reasons: a) its high genetic tractability allows the application of genome-wide genetic screenings; b) the large conservation of the genome integrity pathways allows to extend the findings obtained in yeast to other eukaryotic organisms.
We performed a genome-wide screen, based on the overexpression of the DDC2 DNA damage checkpoint gene in the yeast deletion collection, to identify genome stability genes on the basis of spontaneous accumulation of endogenous DNA damage in the corresponding mutant strains. Our screen identified several genes implicated in the control of genome integrity, highlighting, in particular, a key role for pathways protecting against oxidative stress. We present here the preliminary characterization of a new genome integrity gene, VID22.
We also investigated the mechanisms counteracting a newly discovered source of genome instability, namely ribonucleotides (rNTPs) incorporated in genomic DNA during replication. We uncovered a role for RNase H enzymes, template switch pathways and Pol ζ translesion polymerase in protecting from misincorporated rNTPs. Given that mutations in any of the three human RNase H2 subunits were proven to cause Aicardi-Goutiéres Syndrome, these results might contribute to shed light on the complex and largely unknown pathogenetic mechanism of this rare genetic disease.
Finally, we studied the molecular details underlying the role of Rad9 mediator protein in DNA damage checkpoint activation, exploring the dynamics of Rad9 dimerization, chromatin binding, CDK-dependent phosphorylation and checkpoint activation in G1 and M phases of the cell cycle; in particular, we characterized an M-phase specific pathway for checkpoint activation which is relies on Rad9-Dpb11 interaction.
40
EKER, ARMAND. "Resultats et facteurs pronostiques du retrecissement valvulaire aortique opere au stade iii ou iv de la classification de la n. Y. H. A. : a propos de 112 patients operes entre 1972 et 1990". Lyon 1, 1991. http://www.theses.fr/1991LYO1M120.
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Celik, Celen. "Old Allies Facing New Threats: The Transatlantic Relations Within The Framework Of Nato". Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12608884/index.pdf.
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The September 11 terrorist attacks brought a discourse on the transatlantic rift to the
agenda of international community. In fact, at the end of the CW, the emergence of
the US as the leading hegemonic power gave way to transatlantic divergences
concerning security perceptions and strategies of the post-CW era. Also, NATO has
been challenged with these drastic changes in the international system. Yet, owing to
the initiatives taken for the transformation of the Atlantic alliance during the 1990s,
NATO maintained its relevance for the new world order. However, the divergences
of the US and Europeans on their strategies to deal with the post-September 11
security threats led to another discussions about the future of NATO. Indeed, as the
US&rsquopost-September 11 unilateral policies deepened the transatlantic rift already underway since the end of the CW, on the way to Iraq war, NATO turned out to be the place where the divisions between the allies were reflected the most. Hence, the US&rsquo
preferences for ad hoc coalitions of the willing understanding damaged the longduring multilateral alliance by leading to a secondary role for NATO during the US&rsquo
Afghanistan and Iraq campaigns. That is why, time is needed to see whether the old allies facing new threats can reconcile their differences in the name of a renewed transatlantic security cooperation through the initiatives taken within NATO?
42
Deger, Deniz. "The Evolution Of Central Eurasia Policy Of The Us In The Post-soviet Era And The Geopolitics Of The Caspian Oil". Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607703/index.pdf.
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The objective of this thesis is to analyze the US Central Eurasia Policy in the period between 1991 and 2006. Within this context, the purpose is to figure out the foremost motive behind the US&rsquos strategic engagement in the region with a due regard to changing geopolitical context with the demise of the Soviet Union. The main argument rests upon the assumption that the US regional policy is primarily motivated by geopolitical imperatives as the Central Eurasian region becomes the primary springboard for the attainment of global supremacy. Within this respect, energy is only one aspect of the ongoing geopolitical competition. That the geopolitical priorities are preponderant to geoeconomic interests are basically observed by the intense geostrategic struggle over dominating the prospective oil and gas pipelines from the region. Eventually, within the confines of this thesis, it is deduced that the ultimate parameters of the geopolitical struggle, the framework of which was specified by the United States, have revealed themselves more explicitly in the aftermath of the September 11, which only reinforced the strategic significance of Central Eurasia in coping with the new geopolitical fault lines of the 21st century. Within this regard, Central Eurasia has transformed into an implicit geostrategic standoff between the United States on the one hand, and Russia and China on the other. Accordingly, the fact that the United States could by no means remain complacent about the fate of Central Eurasia against such a backdrop of high geopolitical fluidity in the overall Eurasian continent is most relevant to the possibility of rising potential aspirants for global dominance that would challenge the United States in the long term.
43
Hengstebeck, Thomas. "Measurement of the energy spectrum of the BL Lac object PG1553+113 with the MAGIC telescope in 2005 and 2006". Doctoral thesis, [S.l.] : [s.n.], 2007. http://deposit.ddb.de/cgi-bin/dokserv?idn=985223839.
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Larsabal, Etienne. "Découverte des motifs souples de classe A : une nouvelle classe de sites d' interaction ADN-protéines chez les procaryotes et eucaryotes inférieurs". Paris 6, 2005. http://www.theses.fr/2005PA066216.
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45
Gustafson, Melissa Brown. "The Valuation of Literature: Triangulating the Rhetorical with the Economic Metaphor". Diss., CLICK HERE for online access, 2004. http://contentdm.lib.byu.edu/ETD/image/etd510.pdf.
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46
Farro, Lazo Jorge. "Implementación de Sistema Integrador de Comunicaciones de Voz y Datos para el Gobierno Regional de Lima - Utilizando Plataforma Cisco Unified Communications Manager 7.0". Bachelor's thesis, Universidad Ricardo Palma, 2010. http://cybertesis.urp.edu.pe/handle/urp/87.
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Technology nowadays is evolving at rates that surpass anything imagination could perceive and
it certainly affects every public or private enterprise. Well, according to this topic, I’m
suggesting the improvement of the communications network of the Regional Government of
Lima based on an integrated data and voice platform which includes a Cisco Centralized IP
Telephony solution, called Cisco Unified Communications Manager 7.0, that works as a main
element in order to achieve meaningful and complete management of internal and external
telephone calls within MPLS Networks. Regional Government of Lima has been chosen because
of its importance related to the economic activities of the population and the support that could
be brought by an institution which could make success and generate productivity about rapid
administrative processes .
The thesis is divided into distinct chapters that make up the context of the investigation
which involves network planning and design as an iterative process, encompassing topological
design, network realization, IT asset sourcing and operations planning. For this purpose,
information about the old and non sophisticated network status was raised. Costs and more
details such as hardware and software features and more ways to make this network work so
much better, with all the resources at its disposal, will be found on this whole solution
47
Russo, Florence. "Matériaux multicaloriques : Application à de nouveaux systèmes de refroidissement". Thesis, Lyon, INSA, 2015. http://www.theses.fr/2015ISAL0097/document.
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Le domaine du refroidissement est en constante expansion, le système actuel est basé sur la compression/décompression des fluides. Face aux problèmes environnementaux et économiques que ce système présente (natures des fluides frigorigènes et leurs recyclages, nuisances sonores et vibratoires, réglementations contraignantes), de nouvelles solutions techniques alternatives émergent. Ainsi ce travail de thèse porte sur de nouveaux systèmes de refroidissement basés sur les effets électrocalorique et magnétocalorique, respectivement présents dans des films minces de polymère fluoré et dans des composites à matrice polymère et à charges magnétocaloriques. A travers des caractérisations physico-chimiques, électriques, électrocaloriques et magnétocaloriques ces travaux se proposent d’identifier l’origine de l’effet électrocalorique dans des films minces de terpolymère P(VDF-TrFE-CTFE) ferroélectrique relaxeur, mais également d’étudier l’influence de la dispersion des particules magnétocaloriques La(Fe,Si)H dans une matrice polymère de poly(propylène) sur le phénomène magnétocalorique. De plus, dans le cadre de cette thèse, un appareil de mesure directe de l’effet électrocalorique a été développé avec le Dr. Basso de l’INRIM de Turin. La comparaison avec la méthode de mesure indirecte permet d’aborder ce phénomène d’un point de vue thermodynamique afin de faire le point sur la validité des hypothèses thermodynamiques utilisées dans le cas d’un polymère ferroélectrique relaxeurThe cooling sector is in constant expansion, the current system is based on the compression/decompression of fluids. In front of environmental and economic problems of this system (nature of frigorigen fluids and their recycling, noise and vibration issues, restrictive regulations), new alternative technological solutions emerge. Thus this thesis provides new cooling systems based on the magnetocaloric and electrocaloric effects respectively present in thin films of fluoropolymer and composites with polymer matrix and magnetocaloric loads. Through physicochemical, electrical, electrocaloric and magnetocaloric characterizations, this work intends to identify the origin of electrocaloric effect in thin terpolymer films P(VDF-TrFE-CTFE) which is a ferroelectric relaxor, but also to study the influence of the magnetocaloric particles La(Fe,Si)H dispersion in a polymer matrix of poly(propylene) on the magnetocaloric phenomenon. In addition, as part of this thesis, a direct measurement device of the electrocaloric effect was developed with Dr. Basso from the INRIM of Turin. The comparison with the indirect measurement method comes up with this phenomenon from a thermodynamic point of view to take stock of the validity of thermodynamic assumptions used in the case of a ferroelectric polymer relaxor
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Eda, Benlioglu. "Bilateral Relations Between The Us And Saudi Arabia: 1990-2003". Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/2/12606797/index.pdf.
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The objective of this thesis is to analyze the bilateral relations between the US and Saudi Arabia in the period between 1990 and 2003. In this context, the aim is to find out an answer to the question of how the relations between the US-Saudi Arabia have strained after September 11. Accordingly, the thesis contains four main parts. In the first part of the study, the historical background of US-Saudi relations up to the 1990-1991 Gulf Crisis, which was based on oil for security exchange, is studied. In the second part of the study, the security dilemma of Saudi Arabia, the challenges Saudi Arabia faced during the 1990s, and how these challenges affected its relations with the US are discussed. In the third part, September 11 and how global issues like war on terrorism, war in Iraq and democratization in the Middle East came into the agenda of the relationship is scrutinized. Accordingly, this thesis has reached to the following conclusions: First, after September 11, the relations between the two countries became more problematic and have affected by both global issues as well as domestic debates in both countries. Second, despite increasingly problematic nature of the relationship, the two countries managed to continue their strategic relationship, particularly as regards to &ldquowar on terrorism&rdquo
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Pezzotti, Simone. "DFT-MD simulations and theoretical SFG spectroscopy to characterize H-Bonded networks at aqueous interfaces : from hydrophobic to hydrophilic environments Structural definition of the BIL and DL: a new universal methodology to rationalize non-linear χ(2)(ω) SFG signals at charged interfaces, including χ(3)(ω) contributions What the Diffuse Layer (DL) Reveals in Non-Linear SFG Spectroscopy 2D H-Bond Network as the Topmost Skin to the Air-Water Interface Combining ab-initio and classical molecular dynamics simulations to unravel the structure of the 2D-HB-network at the air-water interface 2D-HB-Network at the air-water interface: A structural and dynamical characterization by means of ab initio and classical molecular dynamics simulations Spectroscopic BIL-SFG Invariance Hides the Chaotropic Effect of Protons at the Air-Water Interface Molecular hydrophobicity at a macroscopically hydrophilic surface Graph theory for automatic structural recognition in molecular dynamics simulations DFT-MD of the (110)-Co3O4 cobalt oxide semiconductor in contact with liquid water, preliminary chemical and physical insights into the electrochemical environment". Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLE008.
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Améliorer notre connaissance de la structure de l'eau dans l'environnement spécial offert par une interface est essentiel pour la compréhension de nombreux phénomènes naturels et applications technologiques. Pour révéler cette structure interfaciale de l'eau, des techniques capables de fournir des informations microscopiques, de manière sélective, pour cette couche interfaciale (BIL) sont nécessaires. Dans le présent travail de thèse, nous avons donc étudié les interfaces aqueuses au niveau moléculaire, en couplant la modélisation théorique à partir de simulations DFT-MD avec les spectroscopies SFG et THz-IR. En développant de nouveaux protocoles/outils d'investigation associant simulations DFT-MD et spectroscopie SFG, en particulier pour la rationalisation plus complexe des interfaces chargées, nous avons fourni une compréhension globale de l'effet des conditions interfaciales d'hydrophilicité, de pH, de force ionique sur le réseau des liaisons-H formé dans la couche interfaciale BIL, sur ses signatures spectroscopiques et sur son impact sur les propriétés physico-chimiques. Nous avons montré pour la première fois que, dans des conditions suffisamment hydrophobes, l'eau interfaciale crée des réseaux des liaisons-H bidimensionnels, révélé expérimentalement par les spectres THz-IR. Le réseau-2D dicte la dynamique de l'eau interfaciale, le potentiel de surface, l'acidité de surface, la tension superficielle et la thermodynamique d'hydratation des solutés hydrophobes. Cet "ordre horizontal" aux interfaces hydrophobes est opposé à "l'ordre verticale" obtenu aux interfaces hydrophiles. Nous avons aussi révélé comment les ions et les conditions de pH modifient ces arrangements structurauxImproving our knowledge on water H-Bonded networks formed in the special environment offered by an interface is pivotal for our understanding of many natural phenomena and technological applications. To reveal the interfacial water arrangement, techniques able to provide detailed microscopic information selectively for the interfacial layer are required. In the present thesis work, we have hence investigated aqueous interfaces at the molecular level, by coupling theoretical modeling from DFT-MD simulations with SFG & THz-IR spectroscopies. By developing new investigation protocols/tools, coupling DFT-MD simulations and SFG spectroscopy, in particular for the more complex rationalization of charged interfaces, we have provided a global comprehension of the effect of various interfacial conditions (hydrophilicity, pH, ionic strength) on the HB-Network formed in the interfacial layer (BIL), on its spectroscopic signatures and on its impact on physico-chemical properties. We have shown for the first time that, in sufficiently hydrophobic conditions, BIL interfacial water creates special 2-Dimensional HB-Networks, experimentally revealed by one specific THz-IR marker band. Such 2D-network dictates HBs and orientational dynamics of interfacial water, surface potential, surface acidity, water surface tension and thermodynamics of hydration of hydrophobic solutes. Such "horizontal ordering” of water at hydrophobic interfaces is found opposite to the “vertical ordering” of water at hydrophilic interfaces, while coexistence of the two orders leads to disordered interfacial water in intermediate hydrophilic/hydrophobic conditions. Both DFT-MD and SFG further revealed how ions & pH conditions alter these BIL-water orders
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Gonçalves, Fabricio Mota. "Evapotranspiração e coeficientes de cultivo (KC) da cana-de-açúcar irrigada por gotejamento subsuperficial". reponame:Repositório Institucional da UFC, 2010. http://www.repositorio.ufc.br/handle/riufc/18596.
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GONÇALVES, Fabricio Mota. Evapotranspiração e coeficientes de cultivo (KC) da cana-de-açúcar irrigada por gotejamento subsuperficial. 2010. 64 f. Dissertação (Mestrado em engenharia agrícola)- Universidade Federal do Ceará, Fortaleza-CE, 2010.Submitted by Elineudson Ribeiro (elineudsonr@gmail.com) on 2016-06-21T18:44:18Z No. of bitstreams: 1 2010_dis_fmgoncalves.pdf: 3909193 bytes, checksum: b818df330f21fcd52b71e61d84782c03 (MD5)
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Sugar cane is one of the crops with the highest level of water consumption, with a high evapotranspiration demand throughout most of its cycle. Knowledge of the sugar cane water demand, the time that irrigation should be applied, and how to irrigate the crop are becoming increasingly important for the sustainable development of irrigated sugar cane cultivation, especially in areas of low water availability, as it is the case in northea stern Brazil. The experiment was carried out at the Curu Experimental Field (property of the Embrapa Tropical Agroindustry), located in the Curu-Paraipaba Irrig ation Project, city of Paraipaba-CE (3 ° 29 '20''S, 39 ° 9' 45''W and elevation 30m), in order to determine the evapotrans piration and crop coefficients (Kc) of sugarcane (Saccharum L. officinarium), subsurface drip-irrigated. It was used the SP 6949 sugar cane variety, planted in a spacing of 1.8 m between double rows and 0.4 m between rows within the double row. As to t he irrigation, we used one lateral water line for each double row, buried at a depth of 0.15 m, w ith self-compensating drip emitters, with a flow rate of 1 L h-1, spaced 0.5 m on the water line. The crop was irrigated daily and there were three fertigations per week. The irrigation de pth was periodically adjusted, keeping the soil water potential between -8 kPa to -20 kPa. The crop evapotranspiration (ETc) was determined using a wei ghing lysimeter with a surface area of 2.25 m 2. The reference evapotranspiration (ETo) was estimated by the FAO Penman-Monteith method. The durations of the phenological stages of cane sugar were estimated through analysis of soil cover, with the use of digital images. Durations of 31, 49, 237 and 118 days were observed, respectively for initial, crop development, mid-season and late season stages. The yields achieved within and outside the lysimeter were respectively 144.4 and 108.8 t ha -1 . The total ETc observed during the cycle of the sugar cane was 1074.1 m m, with maximum values of 6.6 mm d-1 during the mid-season stage. Observed Kc values for initial, mid-season and late season stages were respectively 0.23, 1 .03 and 0.50. In the crop development stage, the relationship between Kc and the (crop) soil cover was represented with good accuracy by a negative quadratic model.
A cana-de-açúcar é uma das culturas com maior consumo de água, apresentando uma alta demanda evapotranspirativa ao longo da maior parte do seu ciclo. O conhecimento das necessidades hídricas da cana-de-açúcar, do momento de aplicação da água requerida pela mesma e a forma de aplicação torna-se cada vez mais importante para o desenvolvimento sustentável da sua produção irrigada, principalmente em regiões de pouca disponibilidade hídrica, como é o caso da região Nordeste do Brasil. O experimento foi conduzido no Campo Experimental do Curu, pertencente à Embrapa Agroindústria Tropical localizado no Perímetro Irrigado Curu-Paraipaba, município de Paraipaba-CE (3° 29’ 20’’ S, 39° 9’ 45’’ W e altitude de 30 m), com o objetivo de determinar a evapotranspiração e os coeficientes de cultivo (Kc) da cana-de-açúcar (Saccharum officinarium L.), irrigada por gotejamento subsuperficial. Utilizou-se a variedade de cana SP 6949, plantada no espaçamento de 1,8 m entre fileiras duplas e 0,4 m entre linhas dentro da fileira dupla. Na irrigação utilizou-se uma linha lateral para cada fileira dupla, enterrada na profundidade de 0,15 m, com gotejadores autocompensantes, com vazão de 1 L h-1, espaçados de 0,5 m na linha. A cultura foi irrigada com freqüência diária e foram realizadas três fertirrigações por semana. A lâmina de irrigação foi ajustada periodicamente, mantendo-se o potencial de água no solo entre -8 kPa e -20 kPa. A evapotranspiração da cultura (ETc) foi determinada utilizando-se um lisímetro de pesagem com área superficial de 2,25 m2. A evapotranspiração de referência (ETo) foi estimada pelo método FAO Penman-Monteith. As durações das fases fenológicas da cana-de-açúcar foram estimadas por meio da análise da cobertura do solo pela cultura, determinada com o uso de imagens digitais. Foram observadas durações de 31, 49, 237 e 118 dias, para as fases inicial, de desenvolvimento, intermediária e final, respectivamente. A produtividade alcançada dentro e fora do lisímetro foi de 144,4 e 108,8 t ha-1, respectivamente. A ETc total observada durante o ciclo da cana-de-açúcar foi de 1.074,1 mm, com valores máximos da ordem de 6,6 mm d-1 durante a fase intermediária. Foram observados valores de Kc iguais a 0,23, 1,03 e 0,50, para as fases inicial, intermediária e final, respectivamente. Na fase de desenvolvimento vegetativo a relação entre o Kc e a cobertura do solo pela cultura foi representada com bastante exatidão por um modelo quadrático negativo.