Dissertations / Theses on the topic 'YVO3'
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Novelli, Fabio. "In search of selective excitations for studying out-of-equilibrium properties in strongly correlated electron systems and high temperature superconductors." Doctoral thesis, Università degli studi di Trieste, 2013. http://hdl.handle.net/10077/8588.
Full textNegli ossidi dei metalli di transizione le correlazioni elettroniche, magnetiche e reticolari sono all’origine di peculiari proprietà fisiche come la resistenza magnetica colossale e la superconduttività ad alta temperatura critica. La spettroscopia risolta in tempo è uno strumento unico per separare il contributo dei singoli gradi di libertà. Inoltre, tale tecnica può essere usata per indurre transizioni di fase non-termiche nella materia condensata. In particolare, scegliendo appositi impulsi pompa in combinazione con impulsi sonda in grado di misurarne gli effetti, è possibile “guidare” la materia nello stato fisico desiderato tramite un’eccitazione selettiva. I primi capitoli della tesi introducono lo stato dell’arte, le tecniche sperimentali e i modelli usati per studiare le proprietà ottiche dei cristalli fuori equilibrio. I capitoli successivi sono dedicati a singoli materiali: abbiamo eseguito misure di riflettività risolte in tempo con pompa nel visibile e sonda ad ampio spettro (1-3 eV) su alcuni isolanti di Mott (YVO3 e La2CuO4) e superconduttori (YBa2Cu3O7-d), e con pompa THz (1 THz~4 meV) su GaAs. YVO3 è un prototipico isolante di Mott e mostra una varietà di fasi caratterizzate da peculiari ordini orbitali e magnetici in funzione della temperatura. In questo sistema le eccitazioni ottiche sono direttamente collegate al grado di libertà orbitale, magnetico o elettronico, ma la loro interpretazione è controversa. Eseguendo misure di riflettività risolte in tempo e frequenza abbiamo dimostrato che le due transizioni ottiche ad energie minori (1.8 eV e 2.4 eV) appartengono alla stessa banda: in particolare, la transizione a 1.8 eV è interpretabile come un eccitone di Hubbard, ovvero uno stato quasi legato stabilizzato da una diminuzione di energia cinetica. Inoltre, abbiamo suggerito l’interpretazione della fase metastabile (che sopravvive almeno fino a 1 ns dopo la foto-eccitazione) come una fase disordinata di spin, e che il materiale potrebbe pertanto essere utilizzato come interruttore magnetico ultra-veloce (F.Novelli et al., Phys. Rev. B 86, 165135, 2012). Per studiare la dipendenza della risposta ottica transiente dei cuprati dalla lunghezza d’onda della pompa ci siamo concentrati sul La2CuO4. I nostri risultati dimostrano che l’effetto degli impulsi di pompa non può sempre essere trattato come semplice perturbazione della temperatura del sotto-sistema elettronico, poiché dinamiche molto diverse vengono rivelate quando l’energia degli impulsi di pompa è maggiore o minore dell’energia del gap di trasferimento di carica, che si trova a circa 2 eV. In particolare foto-eccitare sopra gap è analogo ad un aumento di temperatura, mentre foto-eccitare sotto gap “indurisce” il gap di trasferimento di carica. Ciò suggerisce l’esistenza di eccitazioni a bassa energia che inducono una rinormalizzaizione non termica del gap (in preparazione). Per studiare l’interazione fra grado di libertà vibrazionale e grado di libertà elettronico nei sistemi a forte correlazione elettronica abbiamo utilizzato impulsi di pompa con lunghezza d’onda centrale pari a 800 nm e impulsi di sonda nell’intervallo 400-1200 nm su film sottili di YBa2Cu3O7-d drogato in modo ottimale. Le oscillazioni della riflettività transiente palesano due fononi con frequenze di pochi THz che coinvolgono rispettivamente vibrazioni, pressoché pure, di Ba e Cu. Mentre il modo del rame è indipendente, il modo del bario risulta chiaramente accoppiato alla fase superconduttiva. L’ampiezza delle oscillazioni del modo del bario aumenta sotto la temperatura critica e la sua distribuzione spettrale è modificata quando il condensato viene sciolto dagli impulsi di pompa. I nostri risultati offrono una nuova prospettiva nell’interpretazione della dinamica delle transizioni inter-banda dei cuprati che subiscono forti modificazioni sotto TC (in preparazione). Abbiamo studiato un regime misto nell’interazione fra luce e materia tramite misure risolte in fase dell’effetto Franz-Keldysh nell’arseniuro di gallio. L’effetto Franz-Keldysh consiste nella perturbazione delle proprietà ottiche di un semiconduttore in una regione energetica intorno al gap a seguito dell’applicazione di un campo elettrico. Le misure sono state effettuate con impulsi di pompa ultra corti a singolo ciclo ottico nella regione spettrale del terahertz, e impulsi di sonda ad ampio spettro nella regione spettrale del visibile. Regolando l’intensità degli impulsi di pompa abbiamo studiato sia l’effetto Franz-Keldysh dinamico che un nuovo regime di saturazione in cui la “memoria” è importante, ovvero in cui la risposta ottica intorno al gap dipende da una funzione integrale del campo elettrico applicato. I nostri risultati potrebbero essere utili nell’ambito della strumentazione ottica ultra-veloce (F. Novelli et al., Scientific Reports 3, 1227, 2013). In conclusione, abbiamo dimostrato che le eccitazioni selettive sono certamente possibili in diversi ossidi dei metalli di transizione tramite tecniche spettroscopiche ultra-veloci risolte in tempo e frequenza: importanti informazioni fisiche possono essere ottenute regolando il contenuto energetico degli impulsi laser utilizzati.
XXV Ciclo
1984
Preda, Cristina-Elena. "Laser Nd3+:YVO4: dynamique et conduite optimale." Phd thesis, Université des Sciences et Technologie de Lille - Lille I, 2007. http://tel.archives-ouvertes.fr/tel-00169859.
Full textUne première partie présente deux méthodes mises au point pour la génération d'impulsions de forme arbitraire (triangle, gaussienne, impulsion à deux bosses) en dépit de la propension du laser à fournir des impulsions "sécante-hyperbolique". Dans les deux cas un Algorithme Génétique (AG) détermine les paramètres du signal de conduite optimal. Si pour la première méthode ce signal est construit à partir de fonctions élémentaires, pour la seconde il résulte d'une interpolation entre points de collocation fixés par l'AG.
Les outils développés (couplage captures rapides/traitements en temps réel par AG) ont été mis à profit pour étudier la validité des différents modèles décrivant la dynamique des lasers de classe B fonctionnant en régime monomode ou bi-raie. L'AG est alors utilisé pour comparer l'évolution temporelle de l'intensité émise par le laser à celle calculée à partir du modèle. Ils permettent ainsi d'identifier le modèle le mieux adapté et de déterminer ses paramètres.
La bonne connaissance que nous avons de la dynamique de notre laser nous a incité à effectuer une étude détaillée d'effets étonnants induits par une modulation temporelle asymétrique du pompage. Les expériences réalisées constituent la première mise en évidence sur un laser d'un effet "cliquets" similaire à celui proposé par Feynman pour extraire de l'énergie d'un mouvement erratique.
Preda, Cristina-Elena. "Laser Nd³+ : YVO4 : dynamique et conduite optimale." Lille 1, 2007. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/2007/50376-2007-Preda.pdf.
Full textZogo, Mboulou Guy Bertrand. "Étude en spectroscopies optiques du composé laser YVO4:Nd3+." Sherbrooke : Université de Sherbrooke, 1998.
Find full textKallestad, Scott D. "An Annotated Bibliography of Selected Repertoire for Alto Saxophone and Piano for Developing College-Level Alto Saxophonists, with an Analysis of Yvon Bourrel's Sonate Pour Alto Saxophone Et Piano." Thesis, connect to online resource, 2005. http://www.unt.edu/etd/all/Dec2005/kallestad%5Fscott%5Fd/index.htm.
Full textSystem requirements: Adobe Acrobat Reader. Accompanied by 3 recitals, recorded Sept. 18, 1995, Mar. 11, 1996, and Mar. 22, 2004. Includes bibliographical references (p. 90-95).
Mialon, Geneviève. "Monocristaux YVO4:Ln à l'échelle nanométrique : Mécanismes de fluorescence et « upconversion »." Phd thesis, Ecole Polytechnique X, 2009. http://pastel.archives-ouvertes.fr/pastel-00005661.
Full textMialon, Geneviève. "Monocristaux YVO4:Ln à l’échelle nanométrique : Mécanismes de fluorescence et « upconversion »." Palaiseau, Ecole polytechnique, 2009. http://pastel.paristech.org/5661/01/th%C3%A8se_vf.pdf.
Full textLepage, Martin. "Mort et naissance de Christophe Ulric et L'ombre et le double d'Yvon Rivard : lecture mythocritique d'une quête spirituelle." Thesis, Université Laval, 2010. http://www.theses.ulaval.ca/2010/26855/26855.pdf.
Full textFreitag, Markus Verfasser], Hermann [Akademischer Betreuer] [Ney, and Francois [Akademischer Betreuer] Yvon. "Investigations on machine translation system combination / Markus Freitag ; Hermann Ney, Francois Yvon." Aachen : Universitätsbibliothek der RWTH Aachen, 2016. http://d-nb.info/1130871827/34.
Full textTrefon-Radziejewska, Dominika. "Wpływ domieszkowania na zależności temperaturowe dyfuzyjności cieplnej monokryształów YAG, YVO4 i GdCOB." Rozprawa doktorska, Katowice : Uniwersytet Śląski, 2012. https://repolis.bg.polsl.pl/dlibra/docmetadata?showContent=true&id=44225.
Full textTrefon-Radziejewska, Dominika. "Wpływ domieszkowania na zależności temperaturowe dyfuzyjności cieplnej monokryształów YAG, YVO4 i GdCOB." Doctoral thesis, Katowice : Uniwersytet Śląski, 2012. http://hdl.handle.net/20.500.12128/5344.
Full textFreitag, Markus [Verfasser], Hermann [Akademischer Betreuer] Ney, and Francois [Akademischer Betreuer] Yvon. "Investigations on machine translation system combination / Markus Freitag ; Hermann Ney, Francois Yvon." Aachen : Universitätsbibliothek der RWTH Aachen, 2016. http://d-nb.info/1130871827/34.
Full textRoberge, Benoît. "Transitions de phase dans le YVO[indice inférieur 3]." Mémoire, Université de Sherbrooke, 2012. http://hdl.handle.net/11143/5773.
Full textCamargo, Andrea Simone Stucchi de. "Caracterização espectroscópica de possíveis meios ativos para lasers de Nd3+ e Tm3+." Universidade de São Paulo, 2003. http://www.teses.usp.br/teses/disponiveis/76/76132/tde-06062007-180625/.
Full textIn this work we have made an important contribution to the growing research of new laser materials that can be pumped by low cost diode lasers or by the Upconversion process to operate in the near-infrared and visible spectral regions. Three kinds of hosts, doped with the rare earth ions (Nd3+ and Tm3+) were studied, and they present potential characteristics as laser active media. Single crystal fibers of yttrium and gadolinium orthovanadates grown by LHPG are very attractive for the construction of compact lasers due to the versatility and low cost of the growing process. A neodymium-doped YVO4 fiber adapted to an end-pump laser cavity presented efficient emission at 1.064 µm, similar to that obtained for a Czochralski grown bulk crystal. A study of ion-ion and host-ion interactions was done for GaLaS glass to investigate the influence of these processes on fluorescence quantum efficiencies. For GaLaS:Tm3+, positive gain was estimated at 1,8 µm and it was also observed that the 1,47 µm emission is efficient under appropriate pumping. Finally, transparent PLZT ferroelectric ceramic samples were characterized and the results also point out that PLZT:Nd3+ might become a potential laser host.
Aubé, Lanctôt Amélie. "Figurations monstrueuses dans trois oeuvres de Josée Yvon : étude précédée du recueil Désirs fous." Mémoire, Université de Sherbrooke, 2012. http://hdl.handle.net/11143/6488.
Full textParadis, Odile. "La quête du héros romanesque dans Pour un petit chien gris de Yvon Mauffret." Thèse, Université du Québec à Trois-Rivières, 1985. http://depot-e.uqtr.ca/6117/1/000555037.pdf.
Full textCâmara, Sarita Silva. "Propriedades luminescentes Upconversion do YVO4:Er,Yb aplicadas ao estudo forense de resíduo de tiro." reponame:Repositório Institucional da UnB, 2014. http://repositorio.unb.br/handle/10482/16861.
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Este trabalho trata da avaliação da utilização do ortovanadato de ítrio dopado com Er3+ e Yb3+ como marcador luminescente upconversion para a identificação de resíduo de tiro (GSR) e codificação de munições. O YVO4: 2% Er3+,Yb3+ foi sintetizado por combustão, variando-se a concentração de itérbio entre 0,5 e 8 mol%. Este material foi caracterizado por difração de raios X de pó, microscopia eletrônica de varredura, espectroscopia por dispersão de energia e espectroscopia de fluorescência, e apresentou resultados satisfatórios para ser incorporado em munições a fim de possibilitar a identificação dos GSR e codificar munições. Os materiais sintetizados com maiores concentrações de itérbio apresentaram maiores intensidades de luminescência por upconversion, sendo possível identificar visualmente a luminescência do material tanto em processo downconversion (exc = 254 nm) quanto em processo up conversion (exc = 980 nm). A incorporação desse material nas munições e as análises dos resíduo de tiro gerados indicaram que o YVO4:Er3+,Yb3+ possui as características necessárias para serem utilizados como marcadores de GSR, tais como a alta estabilidade térmica e a elevada intensidade luminescente. Também foi possível identificar visualmente a luminescência das partículas coletadas nos resíduos de tiro (exc = 254 e 980 nm). Além das propriedades ópticas, o YVO4:Er3+,Yb3+ impõe uma assinatura química aos resíduos de tiro, permitindo a sua identificação inequívoca. Estes resultados evidenciaram que o sistema YVO4:Er3+,Yb3+ apresenta alto potencial para ser utilizado como marcador para munição, de forma isolada ou associada a outro marcador - o que permite não só a identificação dos resíduos de tiro como também a codificação de munições. ______________________________________________________________________________ ABSTRACT
This work is about the evaluation of using yttrium orthovanadate doped with Er3+ and Yb3+ as an upconverting luminescent taggant for identifying gunshot residue (GSR) and encoding ammunition. The YVO4: 2% Er3+,Yb3+ was synthesized by combustion process varying the concentration of ytterbium between 0.5 and 8 mol%. This material was characterized by X-ray diffraction powder, scanning electron microscopy, energy dispersive spectroscopy and fluorescence spectroscopy, and good results were achieved in order to incorporate this material as GSR taggants and ammunition encoders. The materials synthesized with higher concentrations of ytterbium showed higher intensities of upconversion luminescence, and it was possible to visually identify the luminescence of the material in both processes such as downconversion (exc = 254 nm) and upconversion ((exc = 980 nm). The incorporation of this material in ammunition and analysis of the gunshot residues indicated that YVO4:Er3+,Yb3+ has the characteristics necessary to be used as a GSR taggant, such as high thermal stability and high luminescence intensity. It was also possible to visually identify the luminescence of the particles collected in gunshot residue (exc = 254 e 980 nm). Besides the optical properties, the YVO4:Er3+,Yb3+ imposes a chemical signature on GSR, allowing their unequivocal identification. These results showed that the YVO4:Er3+,Yb3+ system has a high potential to be used as ammunition taggant, both isolated or associated with other taggantes. This fact allows both the identification of gunshot residue and ammunition encoding.
Boucly, Jean-Christophe. "Magnétisme, mystique et ésotérisme chrétiens chez quelques disciples de Nizier Anthelme Philippe : Chapas, Georges Descormier, Emmanuel Lalande, Yvon Le Loup, Marcel Roche, André Dumas (1890-1940)." Thesis, Paris, EPHE, 2015. http://www.theses.fr/2015EPHE5014.
Full textStudying the disciples of Philippe makes it possible to underline the importance of the "pharmakologic" function in religion: magnetism was the mysterious and sometimes troubling force that made it possible to restore balance to the fluids. The Christianism of the disciples of Philippe led them to underline the importance of prayer and to imagine a superior magnetism, a "spiritual magnetism", but they often retained the magnetic oriented terminology: there were still "fluids", "rays" and "energies". The various actors, highly influenced by the occultism of their time, actually imported exogenous elements into a Western esotericism that was originally Christian, such as animal magnetism and the Easternising speculations of the Anglo-Saxon Theosophists in order to foreshadow, in the end, the "mystic-esoteric nebulous" of trends more or less tied to the "New Age" of the second half of the 20th century
Larsen, Marianne. "La figure du langage et le problème de l'origine dans L'Ombre et le double d'Yvon Rivard." Thesis, Université Laval, 2008. http://www.theses.ulaval.ca/2008/25267/25267.pdf.
Full textBarnscheidt, Yvo [Verfasser]. "Einfluss von Kohlenstoff-Deltaschichten auf die Defektausbreitung in der Germaniumepitaxie / Yvo Barnscheidt." Hannover : Gottfried Wilhelm Leibniz Universität, 2021. http://d-nb.info/1238222862/34.
Full textDelen, Xavier. "Amplificateurs laser à cristaux massifs pompés par diode : fibres cristallines Yb : YAG et cristaux Nd : YVO4." Phd thesis, Palaiseau, Institut d'optique théorique et appliquée, 2013. http://pastel.archives-ouvertes.fr/pastel-00996931.
Full textRoy, Daphnée. "(en) revenir suivi de Josée Yvon et ses Filles-commandos bandées : le potentiel révolutionnaire des marginales." Master's thesis, Université Laval, 2020. http://hdl.handle.net/20.500.11794/66688.
Full textChouinard, Stéphanie. "Comment " faire société " en Acadie du Nouveau-Brunswick: à société civile dans oeuvre de Joseph Yvon Thériault." Thesis, University of Ottawa (Canada), 2011. http://hdl.handle.net/10393/28917.
Full textLehnen, Patrick Verfasser], Hermann [Akademischer Betreuer] [Ney, and Franccois [Akademischer Betreuer] Yvon. "Maximum entropy models for sequences: scaling up from tagging to translation / Patrick Lehnen ; Hermann Ney, Franccois Yvon." Aachen : Universitätsbibliothek der RWTH Aachen, 2017. http://d-nb.info/1169915221/34.
Full textLehnen, Patrick [Verfasser], Hermann [Akademischer Betreuer] Ney, and Franccois [Akademischer Betreuer] Yvon. "Maximum entropy models for sequences: scaling up from tagging to translation / Patrick Lehnen ; Hermann Ney, Franccois Yvon." Aachen : Universitätsbibliothek der RWTH Aachen, 2017. http://d-nb.info/1169915221/34.
Full textIchalalene, Zahia. "Étude par spectroscopies Fourier et Raman du matériau laser YVO¦4 dopé au néodyme." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ56916.pdf.
Full textIchalalene, Zahia. "Étude par spectroscopies Fourier et Raman du matériau laser YVO[4] dopé au néodyme." Sherbrooke : Université de Sherbrooke, 2000.
Find full textFillenberg, Simon B. [Verfasser], and Yves A. [Akademischer Betreuer] Muller. "Structural and functional studies of the bacterial transcriptional regulators YvoA and DasR / Simon B. Fillenberg. Gutachter: Yves A. Muller." Erlangen : Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 2015. http://d-nb.info/1075838487/34.
Full textZogo, Mboulou Guy Bertrand. "Étude en spectroscopies optiques du composé laser YVO[indice inférieur 4]:Nd[indice supérieur 3+]." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape15/PQDD_0014/MQ35716.pdf.
Full textIchalalène, Zahia. "Étude par spectroscopies Fourier et Raman du matériau laser YVO[indice]4 dopé au néodyme." Mémoire, Université de Sherbrooke, 1999. http://savoirs.usherbrooke.ca/handle/11143/4432.
Full textErmeneux, Frank-Sébastien. "Cristallogénèse, spectroscopie optique (linéaire et non-linéaire) et propriétés laser des composés Y2O3 et YVO4 dopés par les ions Nd3+, Er3+ ou Tm3+." Lyon 1, 1999. http://www.theses.fr/1999LYO10226.
Full textHermier, Jean-Pierre. "Etude du bruit quantique dans les microlasers semi-conducteurs a cavite verticale (vcsels) et les lasers a solide nd : yvo 4." Paris 6, 2000. http://www.theses.fr/2000PA066518.
Full textGuerchi, Driss. "Équation de Born-Green-Yvon pour un système à deux dimensions : cas isotrope et anisotrope (application à une collection de cristallites d'Au sur un substrat (100)KCl)." Thèse, Université du Québec à Trois-Rivières, 1994. http://depot-e.uqtr.ca/5011/1/000612900.pdf.
Full textDrees, Jan Yvo [Verfasser], Liu Hao [Akademischer Betreuer] Tjeng, Alexander [Akademischer Betreuer] Komarek, Michael [Akademischer Betreuer] Loewenhaupt, and Vladimir [Akademischer Betreuer] Hinkov. "Magnetism in layered Nickelates and Cobaltates / Jan Yvo Drees. Betreuer: Liu Hao Tjeng ; Alexander Komarek. Gutachter: Liu Hao Tjeng ; Michael Loewenhaupt ; Vladimir Hinkov." Dresden : Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://d-nb.info/1083463209/34.
Full textDrees, Jan Yvo [Verfasser], Liu Hao Akademischer Betreuer] Tjeng, Alexander [Akademischer Betreuer] Komarek, Michael [Akademischer Betreuer] [Loewenhaupt, and Vladimir [Akademischer Betreuer] Hinkov. "Magnetism in layered Nickelates and Cobaltates / Jan Yvo Drees. Betreuer: Liu Hao Tjeng ; Alexander Komarek. Gutachter: Liu Hao Tjeng ; Michael Loewenhaupt ; Vladimir Hinkov." Dresden : Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://d-nb.info/1083463209/34.
Full textBouwmans, Géraud. "Microlasers : Dynamique de Couplage et de Polarisation." Phd thesis, Université des Sciences et Technologie de Lille - Lille I, 2001. http://tel.archives-ouvertes.fr/tel-00083926.
Full textL'étude expérimentale du couplage de deux lasers continus a mis en évidence trois régimes dynamiques différents qui apparaissent successivement à mesure que les fréquences propres des cavités des lasers se rapprochent : i) lasers quasi indépendants, ii) instabilités périodiques et chaotiques et iii) verrouillage de phase des lasers.
Le modèle développé pour rendre compte des caractéristiques du couplage introduit un coefficient de couplage complexe. Il reproduit de façon remarquable l'ensemble des résultats expérimentaux et de plus a permis de proposer une méthode fiable de mesure du coefficient de couplage. Une étude détaillée du recouvrement entre les modes des lasers et le profil non uniforme du gain et de l'indice de réfraction a permis d'établir une expression analytique reproduisant correctement l'évolution des parties réelle et imaginaire du coefficient de couplage en fonction de la distance entre lasers.
La dynamique de polarisation des microlasers YAG, et en particulier des lasers Nd3+,Cr4+:YAG, met en jeu la biréfringence liée aux contraintes locales, l'anisotropie de gain induite par un faisceau de pompe polarisé linéairement et de celle de l'absorbant saturable. Suivant l'importance relative de ces différentes anisotropies, le laser peut émettre dans l'un et/ou l'autre des modes propres de la biréfringence ou avoir une polarisation orientée de façon privilégiée suivant l'un des axes cristallins de l'absorbant.
Les observations expérimentales ont pu être reproduites analytiquement et/ou numériquement à l'aide d'un modèle qui rend compte de l'évolution temporelle des composantes du champ selon les axes propres de la biréfringence ainsi que celle de leur phase relative. L'anisotropie du gain est décrite par deux coefficients d'anisotropie respectivement relatifs à la pompe et au laser. L'anisotropie de l'absorbant saturable est prise en compte grâce à l'introduction d'inversions de populations associées à chacun des axes cristallins.
Nigoghossian, Karina [UNESP]. "Membranas de celulose bacteriana contendo nanopartículas de 'YVO IND. 4': 'YB POT. 3+': 'ER POT. 3+'/'HO POT. 3+' para aplicações envolvendo conversão ascendente de energia." Universidade Estadual Paulista (UNESP), 2013. http://hdl.handle.net/11449/108483.
Full textMembranas de celulose bacteriana (CB) foram preparadas contendo nanopartículas (NPs) para conversão ascendente de energia de YVO4:Yb3+:Er3+/Ho3+ e ftalocianina de cloroalumínio (AlClPc), um fotossensibilizador utilizado na terapia fotodinâmica (TFD). As membranas obtidas foram testadas visando seu potencial para aplicação como sensibilizadoras de processos fotoativados na TFD. O desenvolvimento deste novo biomaterial baseou-se no ideal de aplicar estas membranas topicamente sobre a área a ser tratada para que ocorra a liberação do fotossensibilizador e a ativação deste possa ser feita localmente por iluminação no infravermelho, que é convertida em luz visível pelas NPs por conversão ascendente de energia. A excitação no infravermelho é vantajosa para aplicação em sistema biológico, pois permite penetração mais profunda da luz nos tecidos em comparação a luz visível. As propriedades de emissão das nanopartículas foram otimizadas, explorando as condições de síntese e diferentes concentrações relativas dos dopantes, a fim de se obter maior rendimento de conversão infravermelho-vermelho e a emissão na região de absorção/excitação do fotoativo. As NPs YVO4:Yb3+:Ho3+ (79:20:1) se mostraram mais adequadas para tal aplicação, por apresentarem maior intensidade de emissão entre 630 e 690 nm (banda de absorção da AlClPc). A CB foi produzida com diferentes características em relação à espessura e transparência, exibindo até 90 % de transmissão óptica. Os resultados mostraram a viabilidade de se incorporar o fotossensibilizador e as nanopartículas luminescentes na matriz polimérica de CB para administração do fármaco, mantendo-se as propriedades luminescentes de ambos os compostos inseridos no polímero. A eficiência de incorporação (EI) de AlClPc foi estudada para diferentes membranas. Observou-se maior EI para as membranas mais finas com menor concentração de AlClPc. Os estudos de permeação...
Bacterial cellulose membranes were prepared containing upconverting nanoparticles of YVO4:Yb3+:Er3+/Ho3+ and a photosensitizer, Aluminum phthalocyanine chloride (AlClPc). The membranes were tested aiming applications as sensitizers in photoactivated processes (photodynamic therapy - PDT). The development of this new biomaterial was based on the purpose of applying these membranes topically over the area to be treated to release of the photosensitizer and its activation will occur locally under infrared light, that will be converted in visible light by upconverting nanoparticles. Emission properties have been optimized and the material with composition (mol%) YVO4:Yb3+:Ho3+ (79:20:1) showed up adequate with highest emission at the spectral region of absorption/excitation of the photoactive (630- 690nm). BC membranes production have also been optimized regarding thickness and optical transmission. Results showed that the incorporation of the photoactive molecules together with the upconverting nanoparticles is feasible. The photoactive incorporation efficiency was studied. Thinner membranes lead to higher relative efficiencies. Skin permeation and retention in vitro tests have been performed by using Franz cells and pigs ears as skin models. After 6, 12 and 24 hours, AlClPc was retained at the stratum corneum (0.5 g.cm-2) and dermis/epidermis (0.3 g.cm-2). The release system developed here presents potential for topical administration without possibility of systemic absorption that could lead to generalized photosensitization of the patient. The photosensitization through the visible upconverted emission of the nanoparticles under infrared excitation was observed. The 680 nm emission of the AlClPc together with the suppression of the red emission of the nanoparticles were clear evidence of the energy transfer process. Moreover the photophysical properties were evaluated at 1270 nm. The AlClPc oxygen generation was observed in the new...
Nigoghossian, Karina. "Membranas de celulose bacteriana contendo nanopartículas de 'YVO IND. 4': 'YB POT. 3+': 'ER POT. 3+'/'HO POT. 3+' para aplicações envolvendo conversão ascendente de energia /." Araraquara, 2013. http://hdl.handle.net/11449/108483.
Full textCo-orientador: Antonio Claudio Tedesco
Banca: Maria Palmira Daflon Gremião
Banca: Rogéria Rocha Gonçalves
Resumo: Membranas de celulose bacteriana (CB) foram preparadas contendo nanopartículas (NPs) para conversão ascendente de energia de YVO4:Yb3+:Er3+/Ho3+ e ftalocianina de cloroalumínio (AlClPc), um fotossensibilizador utilizado na terapia fotodinâmica (TFD). As membranas obtidas foram testadas visando seu potencial para aplicação como sensibilizadoras de processos fotoativados na TFD. O desenvolvimento deste novo biomaterial baseou-se no ideal de aplicar estas membranas topicamente sobre a área a ser tratada para que ocorra a liberação do fotossensibilizador e a ativação deste possa ser feita localmente por iluminação no infravermelho, que é convertida em luz visível pelas NPs por conversão ascendente de energia. A excitação no infravermelho é vantajosa para aplicação em sistema biológico, pois permite penetração mais profunda da luz nos tecidos em comparação a luz visível. As propriedades de emissão das nanopartículas foram otimizadas, explorando as condições de síntese e diferentes concentrações relativas dos dopantes, a fim de se obter maior rendimento de conversão infravermelho-vermelho e a emissão na região de absorção/excitação do fotoativo. As NPs YVO4:Yb3+:Ho3+ (79:20:1) se mostraram mais adequadas para tal aplicação, por apresentarem maior intensidade de emissão entre 630 e 690 nm (banda de absorção da AlClPc). A CB foi produzida com diferentes características em relação à espessura e transparência, exibindo até 90 % de transmissão óptica. Os resultados mostraram a viabilidade de se incorporar o fotossensibilizador e as nanopartículas luminescentes na matriz polimérica de CB para administração do fármaco, mantendo-se as propriedades luminescentes de ambos os compostos inseridos no polímero. A eficiência de incorporação (EI) de AlClPc foi estudada para diferentes membranas. Observou-se maior EI para as membranas mais finas com menor concentração de AlClPc. Os estudos de permeação...
Abstract: Bacterial cellulose membranes were prepared containing upconverting nanoparticles of YVO4:Yb3+:Er3+/Ho3+ and a photosensitizer, Aluminum phthalocyanine chloride (AlClPc). The membranes were tested aiming applications as sensitizers in photoactivated processes (photodynamic therapy - PDT). The development of this new biomaterial was based on the purpose of applying these membranes topically over the area to be treated to release of the photosensitizer and its activation will occur locally under infrared light, that will be converted in visible light by upconverting nanoparticles. Emission properties have been optimized and the material with composition (mol%) YVO4:Yb3+:Ho3+ (79:20:1) showed up adequate with highest emission at the spectral region of absorption/excitation of the photoactive (630- 690nm). BC membranes production have also been optimized regarding thickness and optical transmission. Results showed that the incorporation of the photoactive molecules together with the upconverting nanoparticles is feasible. The photoactive incorporation efficiency was studied. Thinner membranes lead to higher relative efficiencies. Skin permeation and retention in vitro tests have been performed by using Franz cells and pigs ears as skin models. After 6, 12 and 24 hours, AlClPc was retained at the stratum corneum (0.5 g.cm-2) and dermis/epidermis (0.3 g.cm-2). The release system developed here presents potential for topical administration without possibility of systemic absorption that could lead to generalized photosensitization of the patient. The photosensitization through the visible upconverted emission of the nanoparticles under infrared excitation was observed. The 680 nm emission of the AlClPc together with the suppression of the red emission of the nanoparticles were clear evidence of the energy transfer process. Moreover the photophysical properties were evaluated at 1270 nm. The AlClPc oxygen generation was observed in the new...
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Monek, Daniel Glenn. "A comparative style analysis of five early-to-mid sixteenth-century lamentation composers : Juan Escribano, Costanzo Festa, Elezear Genet (Carpentras), Cristóbal de Morales, and Yvo Nau." Thesis, University of Edinburgh, 1999. http://hdl.handle.net/1842/22502.
Full textGuillot-Noël, Olivier. "Probabilites de transition et largeur des raies d'absorption dans la matrice laser yvo 4:nd : interactions nd-nd et nd-matrice, effets de champ cristallin, liaison chimique." Paris 6, 1998. http://www.theses.fr/1998PA066508.
Full textPhilippe, Céline. "Elvis Gratton : mythe et microcosme." Thèse, Université d'Ottawa / University of Ottawa, 2011. http://hdl.handle.net/10393/20240.
Full textFleury, Blaise. "NANOPARTICULES LUMINESCENTES D'YVO4 DOPÉ LANTHANIDES: MÉCANISME DE FORMATION ET APPLICATIONS EN COUCHES MINCES." Phd thesis, Ecole Polytechnique X, 2013. http://pastel.archives-ouvertes.fr/pastel-00822149.
Full textVallières, Gabrielle. "D'une littérature de la souveraineté vers une souveraineté littéraire : l'ironie dans le discours essayistique de Liberté de 1980 à 1986." Master's thesis, Université Laval, 2018. http://hdl.handle.net/20.500.11794/32883.
Full textMainguy, Jacinthe. "Représenter l'artiste au Québec : entre la petite société, la mémoire, la nation et la réception de l'art." Thèse, Université d'Ottawa / University of Ottawa, 2011. http://hdl.handle.net/10393/20454.
Full textVareille-Dahan, Claudie. "L'homme sauvage dans le décor architectural en France." Thesis, Tours, 2014. http://www.theses.fr/2014TOUR2004.
Full textAt first, we look for how the character of the Wild Man, hairy, sylvan, medieval symbol of strength and nature, is represented in literature, inspiring through its enlightened embodiment in book margins, letters and large pictures, as well as in the narrative or apotropaic décor of buildings. Then, we analyse its use in all the social types of the seal in which Hairy Men hold armorials; and its transposition, whether in pair or in couple, in the minor arts but above all in the architectural décor. This typology enabled us to choose our examples on the edges of the kingdom, in Brittany and Flanders, then amongst printers. As Scots who emigrated to France and servants of the Crown, Yvon du Fou and Charles II de Chaumont d’Amboise, are perfect illustrations of the systematic use of the Wild Man. Finally, we compare the various formats of the heraldic works in the French public, private and religious places, with our European neighbours’ practices, despite the depredations that occurred in various periods, linked to either politics or ignorance
Manz, Alyssa Sarah Jane Hennings. "Probing Heterogeneous Dynamics One Molecule at a Time: Polystyrene near the Glass Transition." Thesis, 2019. https://doi.org/10.7916/d8-ge1m-yv03.
Full textLarsen, Marianne. "La figure du langage et le problème de l'origine dans L'ombre et le double d'Yvon Rivard /." 2008. http://www.theses.ulaval.ca/2008/25267/25267.pdf.
Full textHuang, Feng-Ming, and 黃豐銘. "Synthesis and photoluminescence of Eu3+-doped YVO4 phosphors." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/8pu39g.
Full text國立虎尾科技大學
光電與材料科技研究所
96
In order to reduce the volatility of vanadium, the sol-gel method is used to prepare the YVO4 and Eu3+-doped YVO4 phosphors. The YVO4 phase was formed at the beginning of 500℃and the optimum condition for YVO4 powders is calcined at 800℃ for 3 hr. The activation energy of crystallization and grain growth for YVO4 is ~ 207.251 kJ/mol and ~ 21.127 kJ/mol, respectively. In addition, europium-activated yttrium vanadate phosphor was synthesized by the sol-gel method. The precursor powders were heated at 800℃ for 3 hr to obtain the good crystallinity with better luminescence properties. XRD results indicate that there is not the second phase presented with increasing the Eu3+ ion concentrations up to 50 mol%. In the photoluminescent (PL) studies, excitation at 318 nm in terms of Eu3+ concentrations in YVO4 powders shows that the YVO4 phosphors display bright red luminescence at about 618 nm belonging to 5D0→7F2 electric dipole transition, and a weak band in the orange region of 5D0→7F1 transition at 594 nm. The time-resolved 5D0→7F2 transition presents a single exponential decay behavior revealing the decay mechanism of the 5D0→7F2 transition is a single decay component between Eu3+ ions only. The saturation of the emission intensity excited by intra-4f transitions occurs when the Eu3+ concentration is 10 mol% with a CIE color coordinate of x=0.6627;y=0.3367 Concentration quenching is active when x > 0.1.
葉宗哲. "Self Q-Switching in Diode-Pumped Nd :YVO4 Lasers." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/66544082762962855043.
Full text東海大學
物理學系
91
The paper examines phenomenon of self-induced great pulse that occur in a plano-concave resonator of diode-pumped Nd:YVO4 without any optical item. Occurring self-Q-switched has two reservations. The resonator length should be crossed through half-spherical length, and output coupling should misalign the optical axis. Some parameters such as SQS second threshold, pulse width, and average power are measured in relation to the pump power, radius of curvature of output coupler. Until now, We get the lowest pulse width 2.75ns by using a 1cm and 98% reflectivity of output coupler. The pulse second threshold is 291mW and repetition rate is 25.1kHz ,and the peak power is 14000 times larger than average output power.
Wang, Yu-Ming, and 王祐銘. "Synthesis and Photo-Luminescent Properties of YVO4:Pr3+ Phosphors." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/jqcbh5.
Full text國立虎尾科技大學
光電與材料科技研究所在職專班
101
In this study, YVO4 was selected as the host material and doped with different concentrations of Pr3+ ions which were synthesized using solid-state reaction method. The structure, micrographics and photoluminescence properties of the synthesized phosphors were investigated by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and fluorescence spectrophotometer, respectively. The XRD results showed that the crystal structure of YVO4:Pr3+ phosphors calcined 1100℃for 8 hr can be attributed to the Orthorhombic structure for YVO4. The SEM images show the particles are irregular, but more uniform distribution for Pr3+ ion concentration is 0.3 mol%. The excitation spectra of YVO4:Pr3+ shows a broad excitation band in the wavelength range of 250-350 nm resulting from the charge transfer transition of Pr3+-O2-. In the wavelength region of 450-500 nm, originates from the f-f transition of 3H4-3P2 within Pr3+ 4f electron configuration. The emission spectra for YVO4:Pr3+ phosphor show that there are the 3P0→3H4, 3H5, 3H6 and 1D2→3H4 transition of Pr3+ ion under an excitation wavelength of 458 nm. The maximum emission intensity is obtained for YVO4 doped with 0.3 mol% Pr3+ ions with a CIE chromaticity coordinates of (x=0.272, y=0.188) and Rc=18.51Å.