Teses / dissertações sobre o tema "Pr6111"
Crie uma referência precisa em APA, MLA, Chicago, Harvard, e outros estilos
Veja os 27 melhores trabalhos (teses / dissertações) para estudos sobre o assunto "Pr6111".
Ao lado de cada fonte na lista de referências, há um botão "Adicionar à bibliografia". Clique e geraremos automaticamente a citação bibliográfica do trabalho escolhido no estilo de citação de que você precisa: APA, MLA, Harvard, Chicago, Vancouver, etc.
Você também pode baixar o texto completo da publicação científica em formato .pdf e ler o resumo do trabalho online se estiver presente nos metadados.
Veja as teses / dissertações das mais diversas áreas científicas e compile uma bibliografia correta.
King, Richard Jay. "Immediate passage : the narrative of Joel H. Brown, with a critical essay on form and style in the sea voyage narrative". Thesis, St Andrews, 2008. http://hdl.handle.net/10023/550.
Texto completo da fonteIrion, Herve Stangler. "Cerâmica varistora à base de SnO2 dopada com Pr6O11". UNIVERSIDADE ESTADUAL DE PONTA GROSSA, 2006. http://tede2.uepg.br/jspui/handle/prefix/1391.
Texto completo da fonteIn this work it was investigated the influence the in influence of the doping Pr6O11 in the electrical conductivity and in the microstructural properties in the basic ternary system (98,95 – x)%Sn02 1,0% Co0 0,05%Ta205. The used concentration of the doping Pr6011 had varied in 0,05%, 0.5% in mol, remaining constant the concentrations for the Co0 and Ta205. The processing applied was the conventional method of mixture of oxides in ambient atmosphere. The samples had been conformed in 50 MPa and sintered in 1350°C for 2 hours. After the sintering the densification of ceramics was verified with a value of 93,63% for the system with 0,1% in mol of Pr6011. The study of the electrical properties for the varistor system Sn02.Co0.Ta205 Pr6011 was carried out in continuous current in the ambient temperature and in function of the temperature. It was observed that the variation in the concentration of Pr6011 modifies the electrical behavior of the ceramics. The electrical parameters found are of [alfa]= 8,0, Er= 319 volts/cm and Vb= 0,66 volts/barrier for basic ternary system and [alfa]= 17,0 Er= 853 volts/cm and Vb= 1,15 volts/barrier with the addition of 0,10% in mol of Pr6011. The system with 0,05% mol 0.1% in mol Pr6011 presents the same value of the non linearity coefficient of the system with 0,1% in mol, however, with lower values of rupture tension and barrier tension (Er= 708 volts/cm and Vb= 0,98 volts/barrier). To concentration above of 0,1% in mol of Pr6011, the increase of the concentration of this doping, starts to be deleterious to the varistor characteristics. This effects is due to the increase in the concentration of the stannate of praseodymium phase (Pr2Sn207). This crystalline phase with the cassiterita phase (Sn02)was characterized by DRX and EDS and quantified by the refinement of Rietveld.
Neste trabalho investigou-se a influência do dopante Pr6O11 na condutividade elétrica e nas propriedades microestruturais no sistema ternário básico (98,95-x)%SnO2.1,0%CoO.0,05%Ta2O5. As concentrações utilizadas do dopante Pr6O11 variaram em 0,05%, 0,1%, 0,3% e 0,5% em mol, mantendo-se constante as concentrações para o CoO e Ta2O5 . O processamento empregado foi o método convencional de mistura dos óxidos. As amostras foram conformadas a 50 MPa e, sinterizadas a 1350ºC por 2 horas em atmosfera ambiente. Após a sinterização verificou-se densificação das cerâmicas, com valor de 93,63% para o sistema com 0,1% em mol de Pr6O11. O estudo das propriedades elétricas para o sistema varistor SnO2.CoO.Ta2O5 Pr6O11 foi realizado em corrente contínua a temperatura ambiente e, em função da temperatura. Observou-se que a variação na concentração de Pr6O11 altera o comportamento elétrico das cerâmicas. Os parâmetros elétricos encontrados são de [alfa] = 8,0, Er= 319 volts/cm e Vb= 0,66 volts/barreira para o sistema ternário básico e, [alfa] = 17,0, Er= 853 volts/cm e Vb = 1,15 volts/barreira com a adição de 0,10% em mol de Pr6O11. O sistema com 0,05% em mol de Pr6O11 apresenta o mesmo valor do coeficiente de não linearidade do sistema com 0,1 % em mol, entretanto, com valores menores de tensão de ruptura e tensão de barreira (Er= 708 volts/cm e Vb= 0,98 volts/barreira). Para concentrações acima de 0,1% em mol de Pr6O11, o aumento da concentração desse dopante, passa a ser deletério para as características varistoras. Esse efeito é devido ao aumento na concentração da fase cristalina estanato de praseodímio (Pr2Sn2O7). Essa fase cristalina, juntamente com a fase cassiterita (SnO2), foi caracterizada por DRX e por EDS e, quantificadas pelo refinamento de Rietveld.
Zinatloo-Ajabshir, S., e M. Salavati-Niasari. "Facile Solvent-Less Preparation, Characterization and Investigation of Photocatalytic Properties of Pr6O11 Nanostructures". Thesis, Sumy State University, 2015. http://essuir.sumdu.edu.ua/handle/123456789/42498.
Texto completo da fonteOlegario, Renata Cristina. "ESTUDO DOS SISTEMAS CeO2(1-x) :Pr6O11(x); CeO2(1-x):Fe2O3(x) E CeO2(0,95-x): Pr6O11(0,05):Fe2O3(x) PARA APLICAÇÃO COMO PIGMENTOS INORGÂNICOS DE BAIXA TOXICIDADE". UNIVERSIDADE ESTADUAL DE PONTA GROSSA, 2012. http://tede2.uepg.br/jspui/handle/prefix/2098.
Texto completo da fonteConselho Nacional de Desenvolvimento Científico e Tecnológico
This study focused on the Cerium oxide (CeO2) based pigmenting systems, doped with Praseodymium oxide (Pr6O11) and hematite (Fe2O3 – iron oxide) synthesized through the solid state reaction (OM – oxide mixture) and the Pechini method. Simultaneously, CeO2-Pr6O11-Fe2O3 ternary system pigments were synthesized through OM, with the addition of mineralizers. The samples synthesized through OM were wet homogeneized, in isopropyl alcohol, in a horizontal ball mill for 18 hours and dried in oven at 110 C, then thermally treated at 1300 ºC for 3 hours. In samples synthesized through the Pechini method, the process started from the synthesis of the polymeric resin, formed by the citric acid reaction, glycol ethyl, water and the desired oxide salts, kept in thermal blanket at 150 C, under constant agitation for 2 hours, following two thermal treatments at 300 C for 2 hours, and then one at 900 C for 3 hours. After the thermal treatment the pigmenting systems were characterized through XRD, UV-Vis reflectance spectroscopy, scanning electronic microscopy, Raman spectroscopy and thermal analysis, determining the phases present, the colorimetric parameters, band gap values, micro-structural agglomerations and thermal and chemical stability to glass enamel. Single phase pigments were obtained in the binary system CeO2-Pr6O11, with addition of up to 10% Pr6O11 synthesized through OM and up to 3% Pr6O11 synthesized through the Pechini method, whereas the binary system CeO2-Fe2O3, presented single phase only in OM synthesis, with concentrations up to 2% of Fe2O3. More intense shades were obtained in pigments with addition of up to 5% mol praseodymium oxide in the CeO2-Pr6O11 system, and with up to 3% mol iron oxide in the CeO2-Fe2O3 system. The ternary system CeO2-Pr6O11-Fe2O3 presented secondary phase PrFeo3, remaining this phase even with the addition of mineralizers. The pigments applied to low temperature frits (LTF) and windscreen glass (WSG) showed chemically and thermally resistant at 800 C, free of surface defects on the ceramic plates, presenting better dispersion and color homogeneity.
A presente pesquisa estudou os sistemas pigmentantes à base de óxido de cério (CeO2) dopados com óxido de praseodímio (Pr6O11) e hematita (Fe2O3 - óxido de ferro), sintetizados pelo método de reação de estado sólido (mistura de óxidos - MO) e pelo método Pechini. Paralelamente foram sintetizados pelo método MO, pigmentos do sistema ternário CeO2-Pr6O11-Fe2O3 com adição de mineralizadores. As amostras sintetizadas por MO foram homogeneizadas a úmido, em álcool isopropílico, em um moinho de bolas horizontal por 18 horas e secas em estufa a 110 C, e tratadas termicamente a 1300 C por 3 horas. Nas amostras sintetizadas pelo método Pechini partiu-se da síntese da resina polimérica, formada pela reação de ácido cítrico, etileno glicol, água e os sais contendo os íons metálicos dos óxidos pretendidos, mantida em manta térmica a 150 C, sob agitação constante, por 2 horas, sendo tratadas termicamente duas vezes a 300 C por 2 horas, e, na sequência, a 900 C por 3 horas. Após tratamento térmico os sistemas pigmentantes foram caracterizados por difração de raios X, espectroscopia de reflectância na região do UV-Vis, microscopia eletrônica de varredura, espectroscopia Raman e análise térmica, sendo determinadas as fases presentes, os parâmetros colorimétricos, valores de band gap, aglomerações micro estruturais e a estabilidade térmica e química frente à esmaltação vítrea. Pigmentos de fase única foram obtidos no sistema binário CeO2-Pr6O11, com adição de até 10% de Pr6O11 sintetizado por MO e com até 3% de Pr6O11 sintetizado por Pechini; já no sistema binário CeO2-Fe2O3, fase única somente em sínteses por MO, com concentrações até 2% de Fe2O3. Tonalidades mais intensas foram obtidas nos pigmentos com adição de até 5% mol de óxido de praseodímio no sistema CeO2-Pr6O11, e com adição de até 3% mol de óxido de ferro no sistema CeO2-Fe2O3. O sistema ternário CeO2-Pr6O11-Fe2O3 apresentou fase secundária PrFeO3, persistindo esta fase mesmo com adição de mineralizadores. Os pigmentos aplicados em frita de baixa temperatura (FBT) e vidro de pára-brisa (VPB) se mostraram resistentes química e termicamente a 800 ºC, sem presença de defeitos superficiais nas placas cerâmicas, apresentando melhor dispersão e homogeneidade da cor.
Casali, Graziela Pereira. "Pigmentos cerâmicos nanométricos a base de CeO2 dopado com Pr6O11, NiO e CoO". Universidade Federal de São Carlos, 2005. https://repositorio.ufscar.br/handle/ufscar/6362.
Texto completo da fonteUniversidade Federal de Minas Gerais
In the last few years, the study of ceramic materials has increased very fast, mainly studies related to advanced ceramics. The several applications of these materials as ceramic pigments in nanometric scale justify more and more the need for a better understanding of the influence of the dopant addition on the final properties. In this present work, it was studied structural and morphological properties of ceramic pigments based on CeO2 doped with different molar percentages of praseodymium, nickel and cobalt. These properties were also analyzed under the influence of oxidizer (O2) and inert (N2) atmospheres applying different calcination temperatures. The goal of this work was to obtain nanosized ceramic pigments with. The chemical route adopted to obtain materials was the polymeric precursor method. It was obtained stable nanosized pigments, being observed the predominance of the dark red, brown and gray colors for systems doped with praseodymium, nickel and cobalt, respectively.
Nos últimos anos, o estudo de materiais cerâmicos vem evoluindo muito rapidamente, principalmente os estudos relacionados com cerâmicas avançadas. As diversas aplicações envolvendo estes materiais, tal como pigmentos cerâmicos com partículas nanométricas, justificam cada vez mais a necessidade de uma melhor compreensão da influência da adição de dopantes nas propriedades finais. No presente trabalho propõe-se analisar e estudar as propriedades estruturais e morfológicas de pigmentos cerâmicos a base de CeO2 dopado com diferentes porcentagens molares de praseodímio, níquel e cobalto. Estas propriedades, também foram analisadas sob a influência da adição de atmosfera oxidante (O2) e inerte (N2) nas diferentes temperaturas de calcinação. Um dos principais objetivos foi o de obter pigmentos cerâmicos com tamanho de partícula nanométrica. O processo químico adotado para a obtenção dos pós foi o método dos precursores poliméricos. Foram obtidos pigmentos nanométricos estáveis, observando-se a predominância das cores vermelho marrom e cinza escuro para os sistemas de céria dopados com praseodímio, níquel e cobalto, respectivamente.
De, Rancourt Yoann. "Dispersion de charges d'oxydes de terres rares, Er2O3 et Pr6O11, dans une matrice polymère". Thesis, Montpellier 2, 2013. http://www.theses.fr/2013MON20202.
Texto completo da fonteThis thesis focuses on the incorporation of mineral fillers of erbium oxide, Er2O3, and praseodymium oxide, Pr6O11, in an elastomeric polymer matrix, in the context of an industrial project to replace the lead in radiation protection equipment. The actual purpose of this thesis was to improve the dispersion of the fillers in the matrix through chemical treatment processes of these particles. Various types of surface functionalization were used to compatibilize them with an organic matrix, in particular by grafting compounds such as phosphonic acids. Hence, several phosphonic acids have been successfully used for the functionalization of both types of fillers. The characterization of these functionalizations is an important part of this project. Innovative analysis techniques, both direct and indirect have been used for this purpose, namely Py-GC/MS to detect the chemical compounds anchored to the surface of the fillers, X-ray fluorescence and FTIR spectroscopy with a quantification target, but also a study of sedimentation kinetics of the fillers in an organic medium. Finally, composites were obtained by mixing the fillers, untreated and treated, with a polyurethane matrix. Tensile tests have clearly shown an improvement of mechanical properties for some of the composites, due to the functionalization of the fillers by phosphonic acids
Beynon, Richard Jonathon. "'Ugly Lovely' : being a work of creative writing with accompanying critical commentary". Thesis, University of Sussex, 2013. http://sro.sussex.ac.uk/id/eprint/47227/.
Texto completo da fonteWorley, Christiana. "Rising Star". Thesis, St Andrews, 2007. http://hdl.handle.net/10023/321.
Texto completo da fonteRadcliffe, Mark. "What happens to bruised or damaged nurses?" Thesis, University of Sussex, 2014. http://sro.sussex.ac.uk/id/eprint/51407/.
Texto completo da fonteEckstein, Sue. "Homage or damage - the scope and limitation of autobiographical fiction". Thesis, University of Sussex, 2011. http://sro.sussex.ac.uk/id/eprint/7583/.
Texto completo da fontePestell, Alex. "Geoffrey Hill : poetry, criticism and philosophy". Thesis, University of Sussex, 2012. http://sro.sussex.ac.uk/id/eprint/39686/.
Texto completo da fonteDownes, Gareth J. "James Joyce, Catholicism and heresy : with specific reference to Giordano Bruno". Thesis, University of St Andrews, 2002. http://hdl.handle.net/10023/14800.
Texto completo da fonteGallant, Deborah Anderson. "K 'N' T and the accompanying critical analysis of creative process". Thesis, St Andrews, 2008. http://hdl.handle.net/10023/484.
Texto completo da fonteLowe, Sarah Elizabeth. "Players and performances in early modern Gloucester, Tewkesbury and Bristol". Thesis, University of Gloucestershire, 2008. http://eprints.glos.ac.uk/3394/.
Texto completo da fonteWaldvogel, Audrey. "Mise au point d'un catalyseur performant pour la chaîne de procédé Power-to-Methane et étude cinétique". Thesis, Strasbourg, 2017. http://www.theses.fr/2017STRAF077/document.
Texto completo da fonteThe environmental (global warming) and political (increase of the renewable electric farm) context leads to a mutation of the French energy landscape. Synthetic methane is presented as a energy carrier for storing and transporting renewable electricity in overproduction while recycling CO2, a process called Power-to-Methane. One of the objectives of the thesis is to develop an active catalyst for the co-methanation of a post-co-electrolysis mixture H2/CO/CO2/H2O/CH4 (CHOCHCO ANR project). A Ni/CZP type catalyst was synthesized in this purpose. The optimization of the coprecipitation synthesis by the combination of the precipitating salt (NH4)2CO3 and the surfactant CTAB has led to a high performance catalyst (absence of alkaline poison and increase of the specific surface area) able to produce CH4 at low temperature (250 °C) with a high yield. The catalyst showed a satisfactory resistance to carbon deposition and sintering deactivation, which is a key point for the intermittent operating conditions of the process. A kinetic model, of the Langmuir-Hinshelwood type, was developed for the first time on a Ni/CZP type catalyst
Smith, Warwick. "War and space in English fiction, 1940-1950". Thesis, University of Sussex, 2016. http://sro.sussex.ac.uk/id/eprint/61022/.
Texto completo da fonteClark, Samantha Jane. "The subtle ether : writing into the 'space between'". Thesis, University of St Andrews, 2017. http://hdl.handle.net/10023/16028.
Texto completo da fonteChalmers, Aimée Y. "The singin lass : a reflection on the life of the poet Marion Angus (1865-1946) in the form of an account of her life and work, and three extracts from 'Blackthorn', a novel". Thesis, University of St Andrews, 2010. http://hdl.handle.net/10023/1846.
Texto completo da fonteBarber, Rosalind. "Writing Marlowe as writing Shakespeare". Thesis, University of Sussex, 2012. http://sro.sussex.ac.uk/id/eprint/39699/.
Texto completo da fonteNewell, Marilee. "The wyvern's tale : a thought experiment in Bakhtinian dual chronotope occupation". Thesis, University of St Andrews, 2010. http://hdl.handle.net/10023/2154.
Texto completo da fonteLyall, Scott. "The politics of place in the work of Hugh MacDiarmid". Thesis, University of St Andrews, 2004. http://hdl.handle.net/10023/14752.
Texto completo da fontePhillips, Malcolm. "Experiment and representation : the domestic surreal in contemporary British and American poetry". Thesis, University of St Andrews, 2004. http://hdl.handle.net/10023/14707.
Texto completo da fonteSan, Yo-min, e 沈祐民. "A study on the varistor properties for Pr6O11-ZnO varistor". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/62455422525509440156.
Texto completo da fonte國立成功大學
資源工程學系碩博士班
95
In this study, ZnO varistor doped with Pr6O11, Co3O4, were prepared using traditional solid-state reaction method. In order to decrease the sintering temperature, trace additive, Na2CO3, was added as a sintering aid. The effects of the additive, sintering temperatures, cooling rate on the microstructures and electrical properties of (Pr,Co,Na)-added ZnO ceramics were investigated using XRD, XPS, FESEM, and EPMA. The observed results can be described as follows: 1. The samples added Na2CO3 possessed better varistor properties. 2. Better varistor properties can be obtained for the samples with much crystalline PrOx phase. 3. For the sample with a slow cooling rate, O2 had a much time to diffuse at grain boundary which resulted in the more adsorption of O2 on the surfaces of the grains. Therefore the superior varistor properties were obtained for the sample with a slow cooling rate compared to the sample with a rapid cooling rate. For the sample with a rapid cooling rate, PrOx phase was observed to be rich in triple point, which resulted in the degradation of varistor properties. In conclusion, the Pr-doped ZnO ceramics added with Na2CO3, sintered at 1200oC, and at cooling rate of 2oC/min can obtain the best varistor properties: α is 19.6 , Eb is 637.6 V/mm, and IL is 285μA.
"Pigmentos cerâmicos nanométricos a base de CeO2 dopado com Pr6O11, NiO e CoO". Tese, Biblioteca Digital de Teses e Dissertações da Universidade Federal de São Carlos, 2005. http://www.bdtd.ufscar.br/tde_busca/arquivo.php?codArquivo=930.
Texto completo da fontelo, hong-wen, e 羅鴻文. "Effects of Fe2O3 addition on the microstructure and electrical properties of ZnO-Co3O4-Pr6O11-based varistors". Thesis, 2009. http://ndltd.ncl.edu.tw/handle/74025130847054469310.
Texto completo da fonte國立成功大學
資源工程學系碩博士班
97
In this study, ZnO-Pr6O11-Co3O4 based varistors were prepared using a conventional solid-state reaction and sintering process. The effects of Fe2O3 addition on the microstructure and varistor properties were investigated. PrOx phases were found to locate at grain-boundaries uniformly as proper amount of Fe2O3 was added. This will promote the diffusion and chemisorptions of excess oxygen ions at the grain-boundaries, which enhances the varistor property. The energy barrier heights of the grain-boundary for the samples were measured using impedance spectroscopy and observed that when the Fe2O3 addition concentration was increased to 0.001mol%, the barrier height can be increased, which improved the varistor behavior. However, as the addition concentration of Fe2O3 was increased above 0.005mol%, most PrOx phase(s) were found to locate at the triple points, and form the second phase, ZnFe2O4, which resulted in the deterioration of the varistor property.
Kerby, Martin Charles. "Watching from the wings : the life of Sir Philip Gibbs". Phd thesis, 2010. http://hdl.handle.net/1885/150050.
Texto completo da fonteEngledow, Sarah Elizabeth Sylvia. "The anomaly : a contextual introduction to the novels of James Kelman, 1984-1994". Phd thesis, 2002. http://hdl.handle.net/1885/151059.
Texto completo da fonte