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Angers, Dominique. "[XAPA] and the eschatology of Hebrews." Online full text .pdf document, available to Fuller patrons only, 2003. http://www.tren.com.
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Ballart, Jordi. "Phonological variation in Barcelona Catalan : the Xava accent." Thesis, Queen Mary, University of London, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.409782.
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Tedesco, Julio Cesar Guimarães 1973. "Estudo magnético e calorimétrico sobre a série TbxPr1-xAl2." [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/277272.
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Orientadores: Adelino de Aguiar Coelho, Lisandro Pavie CardosoTese (doutorado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin
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Resumo: Neste trabalho propomos o estudo de algumas propriedades magnéticas e do efeito magnetocalórico (EMC) de compostos da família TbxPr1-xAl2, onde x = 0,1; 0,2; 0,25; 0,3; 0,4; 0,5 e 0,75. É fato conhecido que dois elementos terras-raras se acoplam antiferromagneticamente quando inseridos em uma rede cristalina do tipo (R,R¿)Al2 se um deles é um elemento terra-rara leve o outro pesado. Desta forma, era esperado que as amostras desta série apresentassem um ordenamento ferrimagnético, o que foi confirmado pelos nossos dados. Comparamos nossos resultados com sistemas semelhantes e com eles fomos capazes de entender a origem de algumas características e aspectos físicos dos materiais, incluindo o EMC. Alguns compostos estudados aqui apresentaram o efeito magnetocalórico inverso, que acontece devido à competição entre as duas subredes magnéticas acopladas antiferromagneticamente. Observamos também os comportamentos da temperatura de transição magnética e dos parâmetros de rede em função da concentração de Tb, e verificamos o deslocamento dos picos do EMC associados à temperatura de transição (TC). Algumas propriedades importantes na aplicação destes materiais em refrigeração magnética foram levantadas e comparadas com a literatura. Verificamos que dois membros da série apresentaram o efeito de Exchange Bias (EB) e, em analogia com sistemas bicamadas FM-AFM em filmes finos, fomos capazes de entender e explicar este efeito. Acreditamos que o efeito de Exchange Bias está associado à forte anisotropia apresentada pelos compostos Tb0.3Pr0.7Al2 e Tb0.25Pr0.75Al2 que ocorre em temperaturas extremamente baixas e à magnetização dos elétrons polarizados de condução. Identificamos também as temperaturas de compensação (propriedades características deste tipo de sistema) nestes compostos
Abstract: In this work we studied some magnetic properties and the magnetocaloric effect (MCE) of the series of compounds TbxPr1-xAl2, where x = 0.1, 0.2, 0.25, 0.3, 0.4, 0.5 and 0.75. It is known from the literature that the moments of a light and a heavy rare earth are antiferromagnetically coupled when they are inserted in a crystal lattice and this was confirmed by our analysis of the experimental data. We compared our results with similar systems and we were able to understand the origin of some features and physical aspects of those materials, including the magnetocaloric effect (MCE). Some compounds show the inverse MCE, associated to the competition between the two magnetic sublattices antiferromagnetically coupled. We also observed the behavior of the magnetic transition temperature (TC) and lattice parameters as a function of the concentration ('x¿), with a corresponding MCE peak shift. Some important properties regarding the application of these materials in magnetic refrigeration are discussed. Two members of the family of compounds show a shifted hysteresis curve which was assigned to the Exchange Bias (EB) effect in analogy with FM-AFM bilayers systems in thin films. We believe that the EB effect is associated with strong unidirectional anisotropy of the magnetic sublattices appeared in Tb0.3Pr0.7Al2 and Tb0.25Pr0.75Al2, which occurs at low temperatures, and with the magnetization of the polarized conduction electrons. We also identified the compensation temperature (characteristic properties of this type of system) in these compounds
Doutorado
Física
Doutor em Ciências
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Santos, Carlos C?sar Rodrigues ds. "Estrat?gias de manejo do pastejo para capim-xara?s." UFVJM, 2014. http://acervo.ufvjm.edu.br/jspui/handle/1/834.
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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES)
Objetivou-se com este estudo, avaliar os efeitos de duas estrat?gias de pastejo intermitente, com 24 dias fixos de descanso e com 95% de intercepta??o luminosa em capim-xara?s. O experimento foi conduzido na Fazenda Experimental do Moura, pertencente ? Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), localizada no Munic?pio de Curvelo, Minas Gerais. Para a avalia??o das caracter?sticas produtivas, estruturais e bromatol?gicas foi utilizado o delineamento inteiramente casualizado com medidas repetidas no tempo, com quatro ciclos de pastejo e duas estrat?gias de pastejo. Para o consumo dos animais foi utilizado o delineamento inteiramente casualizado em arranjo fatorial 2 x 3, sendo duas estrat?gias de pastejo e tr?s dias de ocupa??o, e para a taxa de lota??o utilizou-se o arranjo 2 x 4 (duas estrat?gias e quatro ciclos de pastejo). N?o houve efeito para as vari?veis: disponibilidade, estrutura e composi??o bromatol?gica da forragem, com exce??o para intercepta??o luminosa e prote?na bruta, onde o tratamento com IL obteve maior valor de intercepta??o luminosa (2,73% superior que o DF) e menor teor de PB (1,08% inferior ao tratamento DF). Para o consumo de mat?ria seca houve efeito (P<0,05) entre os dias de ocupa??o, sendo os maiores valores encontrados no primeiro dia (9,84 kg de MS) e os menores no terceiro dia de ocupa??o (6,21 kg de MS). A taxa de lota??o foi 0,76 UA maior para a estrat?gia de manejo com IL, quando comparada ao tratamento DF. Assim, tendo em vista a praticidade de ado??o, boas condi??es edafoclim?ticas, o manejo de pastejo com intensifica??o dos dias fixos apresenta grande potencialidade para uso de pasto.
Disserta??o (Mestrado Profissional) ? Programa de P?s-Gradua??o em Sa?de, Sociedade e Ambiente, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2014.
ABSTRACT The objective of this study was to evaluate the effects of two intermittent grazing strategies, with 24 fixed resting days and 95% light interception in Xara?s grass. The experiment was conducted at the Moura Experimental Farm, belonging to Universidade Feseral dos Vales do Jequitinhonha e Mucuri (UFVJM), in Curvelo, Minas Gerais. For the evaluation of productive, structural and nutritive characteristics, we used a completely randomized design with repeated measures in the time, with four grazing cycles and two grazing strategies. For consumption of animals, we used a completely randomized design, in a 2 x 3 factorial, with two grazing strategies and three days of occupation, and 2 x 4 scheme (two strategies and four cycles of grazing) for stocking rate. There was no effect for the variables: availability, structure and chemical composition of forage, except for light interception and crude protein, in which treatment with LI showed the highest value of light interception (2.73% higher than the fixed days) and lower content of CP (1.08% lower than the fixed days treatment). There was effect for dry matter intake (P <0.05) between the days of occupation, and the highest values found on the first day (9.84 kg DM) and the lowest on the third day of occupation (6.21 kg DM). The stocking rate was 0.76 AU added to the management strategy with LI compared to treatment fixed days. Thus, taking into account practicality of adoption, good soil and climatic conditions, grazing management with intensification of fixed days shows great potential for pasture use.
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Moot, Dennis. "Visual Culture, Crises Discourse and the Politics of Representation: Alternative Visionsof Africa in Film and News Media." Ohio University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1596021641358625.
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Xaba, Morena Samuel. "Synthesis and modelling of Tungsten catalysts for alkene metathesis / Morena Samuel Xaba." Thesis, North-West University, 2011. http://hdl.handle.net/10394/7620.
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The aim of this study was to investigate, theoretically and experimentally, the W(O–2,6–C6H3Cl2)2Cl4
catalyst and to synthesise ‘cage’ alicyclic ligands that will help retain the catalyst during the
membrane separation process. Furthermore, molecular modelling was used in order to explain the
metal–ligand coordination, the active sites in carbosilane dendritic catalysts and to investigate the
mechanistic steps of the W(O–2,6–C6H3Cl2)2Cl4 catalyst in the metathesis of 1–octene.
The W(O–2,6–C6H3X2)2X4 (X = Cl, Br and Ph) catalytic system has been reported in literature, and
the complex with X = Cl substituent was found to have higher activity than the complex with Br and
Ph substituents. However, the complex with Br and Ph substituents were found to have high
selectivity but lower activity. The metathesis of 1–octene by the W(O–2,6–C6H3Cl2)2Cl4 system was
investigated and the results matched well with literature. A theoretical study was done on the
metathesis mechanism of 1–octene in the presence of carbosilane dendritic catalysts and the
W(O–2,6–C6H3Cl2)2Cl4 catalytic system. The electronic energy profiles were plotted by using a
Potential Energy Surface (PES) scan. The preferred routes in the activation steps and in the
catalytic cycles were predicted. The activation steps of the two carbosilane dendritic catalysts are
different from the activation step of the W(O–2,6–C6H3Cl2)2Cl4 catalyst, but the catalytic cycle is in
agreement with that of W(O–2,6–C6H3Cl2)2Cl4. Electronic energy gaps, orbital symmetry and the
orientation of ligands or 1–octene with metal complexes were calculated and analysed. A striking
observation is that in the coordination of the metal complex with either the ligand or 1–octene the
smallest energy gap of the frontier orbitals is always between the lowest unoccupied molecular
orbitals (LUMO) of the metal complex and the highest occupied molecular orbitals (HOMO) of the
ligand/alkene. It was also observed on the energy profiles that the heptylidene species is more
stable than the methylidene species.
Two ‘cage’ alicyclic compounds which differ in their periphery, the “cage divinyl ether” and “cage
diallyl ether” were synthesised and obtained in good yields. Attempts to synthesise dendritic
catalysts/complexes with these ligands as cores of the dendritic catalysts were undertaken. An
electrophilic addition reaction of HCl and Cl2 on the double bonds was observed. An energy gap
analysis of these ligands with the W(O–2,6–C6H3Cl2)2Cl4 system was undertaken. It was found that
the LUMO of W(O–2,6–C6H3Cl2)2Cl4 and the HOMO of the “cage alicyclic compounds” showed a
good possibility of coordination. However, the orbital symmetry and orientation of the metal and
ligand does not permit the coordination of the ligands with the metal complex. In–situ metathesis of
“cage alicyclic compounds” as ligands with W(O–2,6–C6H3Cl2)2Cl4 as catalyst did not give any
metathesis products.Thesis (M.Sc. (Chemistry))--North-West University, Potchefstroom Campus, 2012.
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Johansson, Anna, and Christina Bäck. "Produktionsplaneringsrutiner för manuella svetsresurser." Thesis, University West, Department of Technology, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:hv:diva-795.
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Sousa, Alysson Ericeira. "A PERFORMANCE DO CONTADOR DE HISTÓRIA CONTEMPORÂNEO: a experiência do grupo Xama Teatro." Universidade Federal do Maranhão, 2014. http://tedebc.ufma.br:8080/jspui/handle/tede/12.
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Previous issue date: 2014-01-31Aiming to comprehend the issues related to the storyteller s performance on contemporary days, this essay analyzes the experience of XamaTeatro group, having as a reference the spectacle A carroça é nossa . In order for that, it is discussed about the historical path that has led to disappearance and resurgence of storytellers on urban centers, taking in consideration the concepts of memory, tradition and modernity as well as the studies concerning performance, performativity and theatricality on contemporary scene. The essay results from a qualitative investigation based on a narrative research on which I analyze the training laboratories and the spectacles performed by this research s object group.
Visando a compreender as questões relacionadas à performance do contador de histórias na contemporaneidade, o trabalho analisa a experiência do grupo Xama Teatro, tendo como referência o espetáculo A carroça é nossa. Para tanto, discorre sobre o percurso histórico que levou ao desaparecimento e ao ressurgimento dos contadores de histórias nos centros urbanos, levando em consideração os conceitos de memória, tradição e modernidade, assim como os estudos sobre performance, performatividade e teatralidade na cena contemporânea. O trabalho é resultado de uma investigação qualitativa com base na pesquisa narrativa em que analiso os laboratórios de formação e os espetáculos realizados pelo grupo objeto da pesquisa.
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Xaba, Mgadla Isaac. "Management development as a task of school managers at institutional level / Mgadla Isaac Xaba." Thesis, Potchefstroom University for Christian Higher Education, 1999. http://hdl.handle.net/10394/8995.
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This study investigated management development as a task of school managers by
focusing on: • the need for a new education management development approach in South African schools; • the nature and scope of management development; • the international and national perspectives on the education management development practice; • current education management development activities in Gauteng schools; and • an education management development model for Gauteng schools.
The literature study exposed the need for a new education management development
approach in South African schools, the nature, scope and major aspects of
management development. Furthermore, management development approaches,
techniques and methods as well as guidelines for a new holistic approach are
described. The investigation into the education management development practice for
school managers exposed advanced levels in this regard in the UK and USA.
Malaysia, Zimbabwe and Namibia are engaged in customising effective programmes
for school managers. South Africa is focusing on a holistic approach, with a
significant step taken being, the establishment of the National Institute for Education
Management Development.
The empirical study consisted of a structured questionnaire distributed to a sample
population of I 08 school principals, 80 deputy principals and 210 heads of
departments to investigate their management development needs, experiences and
activities. Main findings revealed a lack of training for school management,
uncoordinated education management development programmes, with existing ones
being reactions to crisis situations, and ill-defined management roles for school
managers. School principals seem solely responsible for school management, thus
exposing a need for a school-based management development approach.
The management development model developed for Gauteng schools focuses on
whole-school development, recognises the participatory management vision of the
new education system, includes stakeholder involvement in education management
development and provides school managers with a model that employs the ODE
Quality Assurance Framework.
The major recommendations flowing from this study include customising education
management linguistics for South Africa, defining job descriptions for school
managers, preparing and inducing school managers, setting education management
qualifications for education management posts and institutionalising the National
Institute for Education Management Development.Thesis (PhD)--PU for CHE, 1999
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Oliveira, Rodrigo Gomes. "Fertilizantes organominerais no crescimento e valor nutritivo de Urochloa brizantha, em diferentes umidades do solo." UFVJM, 2017. http://acervo.ufvjm.edu.br/jspui/handle/1/1532.
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Incluir a Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) como ag?ncia financiadora.Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2017-12-20T20:56:06Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) rodrigo_gomes_oliveira.pdf: 944492 bytes, checksum: 3b83af9fb0686a20d237cd521e8852eb (MD5)
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A pecu?ria exerce uma grande import?ncia nas exporta??es brasileiras. ? uma atividade econ?mica desenvolvida em ?reas rurais que consiste na cria??o de gado, caracterizada pela depend?ncia no uso de pastagens devido ao menor custo de produ??o. Com isso ? necess?rio uma grande ?rea de pastagens bem estruturada e com folhas e perfilhos de boa qualidade para suprir as exig?ncias do rebanho, tendo com isso uma boa lucratividade. Atualmente, uma das esp?cies forrageira que se encontra amplamente difundida no pa?s, ? a Urochloa brizantha (Syn. Brachiaria brizantha). Tal ocorr?ncia ? devida essa gram?nea, ter boa adapta??o a solos menos f?rteis, de textura arenosa e tolerar altas satura??es de alum?nio. Por?m, nas ?reas utilizadas para cultivo destas pastagens muitas se encontram com algum grau de degrada??o devido ? falta de manuten??o, em especial a falta de aduba??o e irriga??o. Propor tecnologias que auxiliem no desempenho dessas pastagens e proporcionem sua recupera??o torne-se essencial. Entre alternativas para diminuir a severidade desses problemas, o uso da irriga??o nos per?odos de veranicos pode ser uma t?cnica a ser usada, por?m existem regi?es no pa?s que a ?gua ? escassa e com isso essa t?cnica ? inv?lida. Outra op??o ? o uso de fertilizantes, por?m ? uma atividade de alto custo, com isso produtores procuram fertilizantes cada vez mais eficazes. O uso de fertilizantes organominerais vem se destacando, devido conter uma parte org?nica na sua formula??o e esta por sua vez, faz com que a libera??o dos nutrientes seja de forma mais lenta, promovendo menores perdas, al?m de auxiliar na reten??o de ?gua no solo.
Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Produ??o Vegetal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2017.
Livestock farming is of great importance in brazilian exports. It is an economic activity developed in rural areas that consists of the cattle raising, characterized by the dependence on the use of pastures due to the lower cost of production. This requires a large, well-structured pasture area with good quality leaves and tillers to meet the requirements of the herd, thus making a good profitability. Currently, one of the forage species that is widely distributed in the country, is Urochloa brizantha (Syn. Brachiaria brizantha). Such occurrence is due to this grass, to have good adaptation to less fertile soils, of sandy texture and to tolerate high saturations of aluminum. However, in the areas used for cultivation of these pastures many are found to have some degree of degradation due to lack of maintenance, especially the lack of fertilization and irrigation. Proposing technologies that aid in the performance of these pastures and make their recovery become essential. Among alternatives to reduce the severity of these problems, the use of irrigation in summer periods may be a technique to be used, however there are regions in the country that water is scarce and thus this technique is invalid. Another option is the use of fertilizers, but it is a high-cost activity, with producers seeking more and more effective fertilizers. The use of organomineral fertilizers has been highlighted, due to the fact that it contains an organic part in its formulation and this, in turn, causes the release of nutrients to be slower, promoting lower losses, besides helping to retain water in the soil.
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Vasconcelos, Gisele Soares de. "Ator-contador: a voz que canta, fala e conta nos espetáculos do Grupo Xama Teatro." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/27/27156/tde-22092016-143149/.
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O trabalho analisa os processos criativos da escritura do texto e escritura do corpo na rapsódia Minha Mãe Preta e nos espetáculos A Carroça é Nossa, A Besta Fera e As Três Fiandeiras, do grupo Xama Teatro. O grupo, com sede em São Luís, Maranhão, desenvolve seus espetáculos tendo como ponto de partida a arte de narrar. Nas produções artísticas do grupo ganha destaque a figura do ator-contador: aquele que canta, conta e fala, que reveza o narrador e a personagem, a primeira e a terceira pessoa. O ator-contador constrói seus passos a partir dos rastros dos rapsodos e griots, do sujeito épico, dos brincantes e narradores anônimos. Com o pé fincado na memória, na tradição e na oralidade, ele fala de si e também fala do outro; com o poder da palavra mescla histórias reais e ficcionais. Para a manifestação da figura do ator-contador são necessárias algumas condições. Entre elas: o uso de uma voz que evoca elementos ausentes; o pensamento do neutro que produz o espaçamento entre a fala e a ação; a noção do espectador como público-ouvinte; o uso de uma fala direta para o público; a criação autoral de obras com textos de vocação oral; a escrita de uma dramaturgia híbrida que mescla os modos épico, lírico e dramático; a inserção do dramaturgo-contador no processo de criação, de forma conjugada com os atores-contadores.This research paper analyzes the creative processes of both text and body writings of the rhapsody Minha Mãe Preta (My Black Mother), and the presentations A Carroça é Nossa (The Cartwheel is Ours), A Besta Fera (The Stupid Beast), and As Três Fiandeiras (The Three Spinners). The Xama Teatro Group, established in the city of São Luís, in the State of Maranhão, develops its presentations having the art of narrating as its starting point. In its artistic productions, the character of the actor-storyteller stands out: he is the one that sings, tells stories and talks, switching from the persona to the narrator, from the first to the third person. The actor-storyteller builds up his steps as from the path of rapsodos and griots, from the epic subject, from the brincantes (players), and from the anonym narrators. With his foot planted in memory, tradition and orality, he speaks of himself and also speaks of others, combining both real and fictional stories. In order to manifest the character of the actor-storyteller, some settings are necessary. Among them: the use of a voice that evokes missing elements; the neutral thought that produces the spacing between speech and action; the notion of the observer being the public listener; the use of a direct speech to the public; the authorial creation of works with oral vocation texts; the writing of a hybrid dramaturgy that mixes the epic, lyric and dramatic modes; the insertion of the playwright-storyteller in the creation process, in a conjugated way with actors-storytellers.
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Rudra, Alok. "Epitaxie en phase vapeur à partir d'organométalliques de GaAs et de Ga1-xAlx pour applications photovoltaïques multispectrales." Grenoble 2 : ANRT, 1987. http://catalogue.bnf.fr/ark:/12148/cb37609596s.
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Bertin, Carolina Sieja. "Sob a sobra de um xale: um estudo sobre a estética de The Shawl, de Cynthia Ozick." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/8/8147/tde-04102013-133412/.
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A Shoá (calamidade, em hebraico) é um dos temas mais pesquisados de todos os tempos, seja por seu caráter perverso, seja por ter modificado a maneira segundo a qual a sociedade lida com a violência. Diante disso, há um tópico especial que chama a atenção: as vítimas e as conseqüências sofridas por elas. É nesse universo que surge The Shawl (1989), o aclamado livro da norte-americana Cynthia Ozick. Tendo em vista a grande complexidade do livro, o presente trabalho examinará a maneira que a autora encontrou para representar tal condição de quem foi exposto à loucura e à violência, e que acabou por criar novas relações entre o seu passado e seu presente, principalmente através de símbolos já conhecidos e de imagens que vão além da cristalização. Nossa hipótese é de verificar, através do estudo dos elementos do texto que vão desde as relações entre os elementos lingüísticos, até a composição das personagens como, no caos aparente, a narrativa encontra sua especificidade estética, por meio do caminho inverso que vai do símbolo às imagens na construção do Real.The Shoah (which means calamity in Hebrew) is one of the most researched topics of all times, either by its perverse character, either because it has modified the way in which society deals with violence. Therefore, there is a special topic that draws societys attention: the victims and the consequences suffered by them. It is in this atmosphere that The Shawl (1989), Cynthia Ozicks acclaimed book, arises. Having in mind the complexity of the book, this work will examine the way the author found to represent the condition of who was exposed to madness and violence, and eventually create new relations between their past and their present, mainly through known symbols and images that go beyond crystallization. Our hypothesis is to verify, through the study of the text elements - from the relationship between the linguistic elements to the composition of the characters - how the narrative finds its aesthetic specificity through the reverse path that goes from symbol to images in the construction of the Real, in the apparent chaos.
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Du, Preez Jenny Bozena. "Re-imagining love and intimacy in the poetry of Gabeba Baderoon, Ingrid De Kok, and Makhosazana Xaba." Thesis, Nelson Mandela Metropolitan University, 2014. http://hdl.handle.net/10948/d1020039.
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This dissertation explores the ways in which the poetry of Gabeba Baderoon, Ingrid de Kok and Makhosazana Xaba challenge the sexist discourses that allow for the exploitation of women‘s bodies. It will also examine how they re-imagine the script 1 of heterosexual romantic love which places women in a submissive position and closes down possibilities for human connections which do not fit within the narrow strictures of this notion of love. The poems selected come from Baderoon‘s two collections, The Dream in the Next Body (2005) and A Hundred Silences (2006), an anthology of Ingrid de Kok‘s poetry spanning all her previous collections entitled Seasonal Fires: New and Selected Poems (2006), and Makhosazana‘s Xaba‘s first poetry collection, These Hands (2005). All three of these contemporary, South African, woman poets present critiques of the sexual exploitation of women and offer explorations of romantic love, relationships and sexual intimacy alternative to contemporary, patriarchal heteronormativity. This analysis will take cognizance of the influence of apartheid and colonial history on the formation of gender politics. It will also examine the representation of women as sexual objects and the spectacularized and graphic depictions of sex and how these poets can be seen to re-present women and re-script sex. Whilst Baderoon and De Kok are concerned with re-imagining heterosexual romantic love and sexual intimacy, their rethinking of love can also be read as useful in engaging with 'queer'2 sexuality and romantic love outside of the heterosexual norm along with Xaba, who is concerned with lesbian desire. Finally, all three poets experiment with traditional poetic form and techniques and it is through this experimentation with poetic language, and the employment of what Julia Kristeva calls the semiotic, that these poets are able to re-imagine love and intimacy. Thus they might be said, to use Kristeva‘s phrase, to stage a 'revolution in poetic language'.
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Alves, Danilo de Oliveira. "Consumo de forragem e produ??o de leite de vacas mesti?as em pastagem de capim-xara?s." UFVJM, 2013. http://acervo.ufvjm.edu.br:8080/jspui/handle/1/321.
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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES)
Objetivou-se, com este trabalho, avaliar a influ?ncia de duas estrat?gias de pastejo de lota??o intermitente, dias fixos de rebrota??o (24 dias) e com desfolha??o aos 95% de IL sobre o consumo de forragem e produ??o do leite de vacas mesti?as Holand?s x Zebu, manejadas em pasto de capim-xara?s. O experimento foi conduzido na Fazenda Experimental do Moura, localizada no Munic?pio de Curvelo, Minas Gerais. Ambas as estrat?gias de pastejo avaliadas (dias fixos e 95% de IL), foram constitu?das por 9 piquetes de aproximadamente 3000 m?, nos quais os animais foram manejados por meio do m?todo de pastejo de lota??o intermitente. Foram utilizadas oito vacas lactantes como animais-teste, em quatro ciclos de pastejo. O ?xido cr?mico foi utilizado como indicador externo e como indicador interno. Foram utilizados a fibra insol?vel em detergente ?cido indigest?vel (FDAi) e a fibra em detergente neutro indigest?vel (FDNi), para determina??o do consumo da MS da forragem. Para isto foram utilizadas amostras do pasto ingerido (extrusa ruminal e pastejo simulado). Para avalia??o da produ??o de leite, foi utilizado o delineamento em Change-over, com efeitos de per?odos e para consumo de mat?ria seca foi utilizado o delineamento inteiramente casualizado em arranjo fatorial 2 x 3 x 4, sendo duas estrat?gias de pastejo, tr?s dias de ocupa??o e quatro repeti??es (animais). As estrat?gias de manejo influenciaram a disponibilidade de massa de forragem pr?-pastejo, com m?dias de 715,6 e 566,4 Kg de MS/ha para IL 95% e DF, respectivamente. Esta diferen?a entre os tratamentos foi obtida sem que a dura??o m?dia dos ciclos fosse afetada, 27,3 e 27 dias para IL e DF, respectivamente, fato este que proporcionou o incremento de 26,3% na disponibilidade de forragem apenas com a estrat?gia de pastejo que preconiza os aspectos fisiol?gicos da planta para colheita. O acr?scimo na produ??o de forragem do tratamento baseado em 95% de IL em compara??o ao tratamento DF resultou em aumento de 11,4% na taxa de lota??o (4,14 e 3,72 UA/ha, respectivamente). A produ??o individual das vacas e a produ??o individual corrigida para 3,5% de gordura n?o foram afetadas pelas estrat?gias de pastejo. A produ??o de leite por unidade de ?rea (kg/ha/dia) foi superior (P<0,05) para o manejo IL, que apresentou 55,75Kg em rela??o ao manejo DF com 49,44Kg. O consumo de forragem n?o foi alterado pelas estrat?gias de pastejo. A estrat?gia de pastejo 95% de IL proporcionou maior taxa de lota??o e maior produ??o de leite por ?rea. O dia de ocupa??o no piquete altera o consumo de mat?ria seca e a produ??o de leite corrigida para 3,5% de gordura.
Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Zootecnia, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2013.
ABSTRACT The objective of this study was to evaluate the influence of two strategies intermittent stocking , fixed days of regrowth (24 days) and the 95 % defoliation IL on forage intake and milk production of crossbred Holstein x Zebu managed on xara?s grass pasture. The experiment was conducted at the Fazenda Experimental Moura, located in the municipality of Curvelo , Minas Gerais. Both grazing strategies evaluated (fixed days and 95% IL), consisted of nine paddocks of approximately 3000 m?, in which the animals were housed by the method of intermittent stocking. Eight cows lactating animals as test in four cycles of pasture. The chromic oxide was used as an external and internal indicator. It was used insoluble fiber, indigestible acid detergent (FDAi) and indigestible neutral detergent fiber (INDF) to determine the consumption of the MS fodder. For this we used samples of pasture intake (ruminal extrusa and simulated grazing). For evaluation of milk production was used in Change-over design , with effect from periods and for dry matter intake was used completely randomized design in a factorial 2 x 3 x 4, two grazing strategies, three days of occupation and four replicates (animals). Management strategies influenced the availability of herbage mass pre -grazing, with averages of 715.6 and 566.4 kg DM/ha for 95 % IL and DF, respectively. This difference between treatments was obtained without the average duration of the cycles were affected, 27.3 and 27 days for IL and DF, respectively, a fact which provided the increase of 26.3 % in forage availability only strategy grazing which advocates the physiological aspects of the plant to harvest. The increase in forage production treatment based on 95 % of IL compared to DF treatment resulted in 11.4% increase in stocking rate (4.14 and 3.72 AU/ha, respectively). The production of individual cows and individual production for 3.5 % fat were not affected by grazing strategies. The milk production per unit area (kg/ha/day) was higher (P < 0.05) for IL management, which had 55.75 kg compared to DF management with 49.44. The forage intake was not altered by grazing strategies .The strategy grazing 95 % of IL provided higher stocking rate and higher milk yield per day of occupation in area. One day of paddock occupation alter the dry matter intake and milk production corrected to 3.5 % fat.
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MENDOZA, CARREÑO Sandra Johana. "Laser aleatório, conversão ascendente de frequência e auto-conversão de frequência em nanocristais de NdxY1.0-XAl3(BO3)4." Universidade Federal de Pernambuco, 2016. https://repositorio.ufpe.br/handle/123456789/24440.
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CAPES
Este trabalho foi dedicado ao estudo dos lasers aleatórios, conversão ascendente de frequência, e a resposta não linear de segunda ordem em nanocristais de borato de alumínio contendo ítrio e neodímio. Serão discutidos temas como espalhamento da luz por nanopartículas, intensidade de retroespalhamento, ganho em meios desordenados, as transições energéticas entre os íons de neodímio, o segundo harmônico do feixe de excitação e do feixe de emissão, a soma de frequências, tempo de vida dos níveis de energia do neodímio, correlacionando as emissões características obtidas nos experimentos com a teoria de conversão ascendente de frequência assistida por um fóton para três transições permitidas no íon de neodímio. Quanto aos resultados serão apresentados (1) a primeira observação de laser aleatório em nanocristais de borato de alumínio com ítrio e neodímio, .−(), na temperatura ambiente, através da análise do comportamento da emissão espectral e temporal oriunda da transição 43/2 → 411/2 em torno de 1.06 (2) observação da resposta não linear de segunda ordem, para diferentes concentrações de neodímio; (3) a conversão ascendente de frequência para NdAB (()) associada a quatro diferentes transições ópticas. Os resultados apresentaram outra forma de analisar a cinética temporal da emissão do laser aleatório, permitindo uma separação da fração de emissão estimulada e espontânea e a comparação desse resultado com o estreitamento da largura de linha, típico de lasers aleatórios. Além disso, é apresentada uma análise da resposta da não linearidade de segunda ordem das amostras e a conversão ascendente de frequências assistida por um fóton com relação à dependência da temperatura e os tempos de vida dos níveis do 3+ nas várias amostras estudadas.
This work was dedicated to the study of random lasers, frequency up conversion, and nonlinear response of second order in nanocrystals of aluminum borate containing yttrium and neodymium. We discuss topics such as light scattering by nanoparticles, backscattering intensity gain in disordered media, energy transitions between energy levels of the neodymium ions, the second harmonic of the excitation beam and the beam emission, sum frequency, lifetime between two energy levels of nedoymium, correlating features emissions obtained in experiments with up conversion theory often assisted by a photon to three transitions allowed in the neodymium ion. The main results presented are: (1) the first observation of random laser in nanocrystals of yttrium aluminum borate and neodymium, .−(), at room temperature, by analyzing the behavior of the spectral and temporal signals associated to the transition 43/2 → 411/2around 1064nm, (2) observation of the nonlinear response of second order, to different concentrations of neodymium; (3) and up conversion frequency NdAB (()) nanocrystals associated with four different optical transitions. The results showed another way to analyze the temporal kinetics of emission of the random laser, allowing a separation of the stimulated and spontaneous emissions and comparing the results with the linewidth narrowing, typical of random laser. Also the second-order response of the samples and up conversion frequency assisted by one photon with respect to the temperature dependence and lifetime of the Nd3+ levels for the several samples studied.
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Rore, Guajardo Marisa del Carmen. "Estudio del endurecimiento en aleaciones Cu-xAl-xNi,CON x=3,5 y 7% at." Tesis, Universidad de Chile, 2012. http://www.repositorio.uchile.cl/handle/2250/111356.
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Ingeniera Civil MecánicaLas aleaciones ternarias Cu-Al-Ni, presentan en el extremo rico en Cu, una solución sólida α de estructura fcc, donde el Al y Ni ocupan posiciones de sustitución. Es sabido que las aleaciones Cu-Al-Ni de estructura inicial fase α, no necesariamente al equilibrio, endurecen por recocido. Durante el desarrollo de esta investigación, año 1994, al revisar la literatura, se encuentra que la mayor parte de las investigaciones originales, respecto al endurecimiento por recocido de las aleaciones Cu-Al-Ni, son previas al año 1950, sin el uso de Microscopía Electrónica de Transmisión (TEM), sino basadas principalmente en análisis por Microscopía Óptica. Una investigación (CANMET, 1977), utiliza Microscopía Óptica, Extracción Química y Microsonda Electrónica. La motivación de este trabajo, es estudiar el endurecimiento por recocido de tres aleaciones ternarias Cu-xAl-xNi, con x = 3, 5 y 7% at., de estructura inicial monofásica α, con técnicas de análisis por Microdureza Vickers (100 g), Microscopía Óptica, agregando la técnica de Microscopía Electrónica de Transmisión TEM. Particularmente, en este trabajo, es de interés verificar si tal endurecimiento se debe principalmente a precipitado de una o más fases, precipitado de partículas finas Ni3Al o precipitado de NiAl, entre otros posibles mecanismos. Debido al tamaño de los precipitados que se trate, la técnica de TEM es aquí realmente necesaria para correlacionar las propiedades y microestructura. Mediante observaciones de TEM sobre la muestra, la Imagen obtenida, permite buscar defectos cristalográficos, como dislocaciones y su comportamiento, y con el Diagrama Difracción de electrones, realizar el análisis radiocristalográfico para identificar las distintas fases cristalinas presentes en la muestra, comparando el Diagrama de la muestra con los Diagramas Patrón clasificados sistémicamente en el atlas publicado por la A.S.T.M. Para los recocidos se consideran tiempos de 1 y 3 h, y temperaturas entre 200 y 800 C. La aleación con x= 3 % at no endurece ni presenta modificaciones en su estructura. Las aleaciones con x= 5 y 7 %at si exhiben endurecimiento por recocido; en cada gráfico Dureza versus Temperatura de Recocido, se observa un máximo de dureza para temperaturas de 550-600 [C]. Este endurecimiento se puede asociar, mediante TEM, a la precipitación de finas partículas esféricas de la fase Ni3Al, con un diámetro medio de 0,02-0,03 μm. Nuestros resultados permiten también ayudar a precisar la ubicación del límite α/α + Ni3Al en el diagrama de equilibrio Cu-Ni-Al a 600C. Los resultados obtenidos serán relevantes para motivar y proponer recomendaciones para continuar el desarrollo de esta línea de investigación, para posteriores investigaciones del endurecimiento en aleaciones Cu-Al-Ni, mediante técnicas de análisis de TEM y Difracción de Rayos X, entre otras, y ampliar el campo de aplicación de estas aleaciones.
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Ruhlmann, Sandrine. "Le partage des prémices et du fond de la marmite : Essai d'anthropologie des pratiques alimentaires chez les Mongols Xalx." Phd thesis, Ecole des Hautes Etudes en Sciences Sociales (EHESS), 2006. http://tel.archives-ouvertes.fr/tel-00346618.
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Les Mongols Xalx (Halh) se définissent comme un peuple d'éleveurs nomades et des mangeurs de viande. Sur fond monographique, la thèse présente une anthropologie des pratiques alimentaires des familles d'éleveurs nomades des steppes et des familles urbaines sédentarisées appartenant aux mêmes réseaux de relations et d'entraides socioéconomiques. À partir d'une étude des techniques d'appropriation des aliments, de leur catégorisation, de leurs traitements culinaires de préparation et de cuisson, de distribution (étiquette) et de consommation (manières de boire et de manger), de tri des restes pour leur conservation et du sort réservé aux déchets, sont analysées les pratiques alimentaires ordinaires et celles relevant de l'hospitalité, ainsi que les pratiques alimentaires extra-ordinaires de fête (naissance) et de revers de fête (mort). Le fil rouge de la thèse est le partage alimentaire, qui confère aux aliments d'autres qualités que nutritives. Selon qu'elles sont cuites ou crues, les nourritures sont offertes à des êtres humains vivants, à des âmes de morts récents, aux mânes des ancêtres, aux esprits maîtres de la nature ou aux divinités bouddhiques pour bénéficier en retour de nombreux bienfaits, et aux âmes des morts errantes pour éviter des malheurs. L'analyse anthropologique révèle en filigrane comment trois systèmes idéologiques -- celui légué par le régime communiste athéiste, le bouddhisme déclaré aujourd'hui religion officielle et le chamanisme qui émerge sous une forme réinterprétée -- cohabitent dans l'esprit des familles après plusieurs périodes historiques d'affrontements et de persécutions.
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Wong, Alan Lip Yau. "Study of Inâ‚â†-â†xâ†-â†yGaâ†xAlâ†yAs multiple quantum well infrared photodetectors grown on GaAs substrates." Thesis, University of Hull, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.273817.
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Sebastião, Lindomar Lili. "Mulher Terena: dos papéis tradicionais para atuação sociopolítica - SenoTêrenoe - kixoku ko´ítukeyea mekuke yoko kóóyene xapa viyénoxapa yoko nâti." Pontifícia Universidade Católica de São Paulo, 2012. http://tede2.pucsp.br/handle/handle/2308.
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Previous issue date: 2012-04-17Fundação Ford
This work program of the Master of Social Sciences, Catholic University of Sao Paulo - PUCSP first contextualizes the Terena people in their historical trajectory from the output of the Paraguayan Chaco. The contact with Brazilian society to the present day, with the focus on the analysis of changes occurring in the cultural sphere of women's roles within their community Terena. Identify which elements were fundamental to this change, pointing to the functions and practices of women and their current social and political field in the village, absorbing new elements from outside, incorporating them into the cultural tradition as a sum. In the mid-nineties start an intensification of women's presence in discussions involving the internal issues. Participation in the sectors covering positions of command, such as associations of women presence in traditional leadership role in school education as teachers, principals of schools in the dual role: the school administration and articulating domestic and foreign policy, presence in universities and search the office of city councilor in the Brazilian national politics, giving a new signification of being a woman Terena
O presente trabalho de Mestrado do programa de Ciências Sociais da Pontifícia Universidade Católica de São Paulo PUCSP, primeiramente contextualiza o povo Terena em sua trajetória histórica desde a saída do Chaco Paraguaio. O contato com a sociedade brasileira até os dias atuais, dando o enfoque na análise das transformações ocorridas no âmbito cultural dos papéis da mulher Terena dentro de sua comunidade. Identifica quais elementos foram fundamentais para esta mudança da mulher no campo social e político da aldeia, apontando para as funções e práticas tradicionais e suas atuais, absorvendo novos elementos vindos de fora, incorporando-os à tradição como soma cultural. Em meados da década de noventa inicia-se uma intensificação da presença das mulheres nas discussões que envolvem as questões internas. A participação nos setores que abrangem cargos de comando, tais como as associações das mulheres, presença na liderança tradicional, atuação na educação escolar como professoras, diretoras de escolas no duplo papel: administração escolar e articuladora da política interna e externa, presença nas universidades e a busca pelo cargo de vereadora na política nacional brasileira, proporcionando uma nova ressignificação do ser mulher Terena
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Sasaki, Yoshikazu. "Synthesis of cis-Xaa-Pro type dipeptide isosteres with samarium(2) diiodide or organocopper reagents." 京都大学 (Kyoto University), 2007. http://hdl.handle.net/2433/137118.
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Xaba, Aupa Josiah. "An evaluation of the administration of social grants as poverty alleviation strategy at the Sedibeng District Municipality / Aupa Josiah Xaba." Thesis, North-West University, 2006. http://hdl.handle.net/10394/2471.
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Nishino, Yoichi, Takahiro Sugiura, Suguru Tanaka, Yuko Tamada, Yusuke Sandaiji, Hidetoshi Miyazaki, Manabu Inukai, et al. "Soft X-ray photoemission study of thermoelectric alloys Fe2−x−yIryV1+xAl and Fe2−xV1+x−yTiyAl." Elsevier, 2011. http://hdl.handle.net/2237/20776.
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Moreau, Stéphane. "Structure de la phase metastable zr 1 xal xo 2 x / 2 elaboree par voie chimique : effet de la synthese." Orléans, 1999. http://www.theses.fr/1999ORLE2016.
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La cristallisation de poudres amorphes d'oxydes mixtes elaborees a partir de precurseurs liquides intervient souvent a des temperatures (400\c-900\c) pour lesquelles la diffusion est tres limitee. Elle peut conduire par exemple a des phases metastables ou a une extension des domaines de solutions solides. Dans le cas de la zircone, ce mode d'elaboration permet l'obtention de solutions solides etendues a temperature ambiante avec des dopants de taille tres inferieure a zr 4 +. L'etude du systeme zro 2-al 2o 3 a ete entreprise afin de montrer l'influence de la synthese des precurseurs amorphes sur la limite de solubilite de al 2o 3 dans l'oxyde de zirconium et de mieux comprendre les mecanismes de stabilisation de la zircone par un cation de taille reduite comme al 3 +. La solution solide metastable zr 1 xal xo 2 x / 2 a ete obtenue par cristallisation de precurseurs amorphes synthetises par precipitation et atomisation. L'extension du domaine de solution solide est fonction de la synthese. Le comportement a la cristallisation de ces precurseurs a pu etre correle a l'environnement local de l'aluminium. La diffraction des rayons x et la spectroscopie raman ont mis en evidence une symetrie de type quadratique pour cette solution solide. De plus, les spectroscopies d'absorption x (exafs du zirconium) et de rmn (mas et multi-quanta mas 2 7al) ont ete mise en uvre afin de determiner la structure locale autour des cations zr 4 + et al 3 + et de preciser la localisation des lacunes d'oxygene. L'etude du systeme ternaire zro 2-y 2o 3-al 2o 3 a permis de montrer l'effet de la presence d'un cation de grande taille comme y 3 + sur la repartition des lacunes et la distribution des cations al 3 + dans la structure. Enfin, l'etude complementaire des systemes zro 2-fe 2o 3 et zro 2-ga 2o 3 a montre une difference de comportement du cation al 3 + par rapport a des cations de taille analogue comme fe 3 + et ga 3 +.
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Andrade, Rodrigo Duarte. "Caracter?sticas estruturais e [produtivas] das cultivares Marandu e Xara?s adubadas com nitrog?nio e pot?ssio em diferentes intervalos ap?s o corte." UFVJM, 2009. http://acervo.ufvjm.edu.br:8080/jspui/handle/1/717.
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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (Capes)
Objetivou-se avaliar o efeito de diferentes intervalos de aplica??o de N e K2O, ap?s o corte, nas caracter?sticas estruturais e produtivas das cultivares Marandu e Xara?s de Brachiaria brizantha. Foram conduzidos dois experimentos em casa de vegeta??o, em esquema fatorial 4 x 2, no delineamento em blocos casualizados, com quatro repeti??es. No experimento 1, ap?s o desbaste das plantas nos vasos, foram aplicadas doses semanais de 50 mg dm-3 de N e K2O, at? uma semana antes do corte de uniformiza??o, totalizando quatro aplica??es, e, ap?s o corte, foram aplicadas doses de 50 mg dm-3 de N e de K2O nos intervalos 0; 3; 6 e 9 dias, sendo as cultivares avaliadas com 44 dias de rebrota??o. No experimento 2, foi aplicada dose ?nica de 50 mg dm-3 de N de K2O, uma semana antes do corte de uniformiza??o e, ap?s o corte, foram aplicados 100 mg dm-3 de N e de K2O nos intervalos 0; 4; 8 e 12 dias, avaliando-se as cultivares com 39 dias de rebrota??o. No experimento 1, somente a produ??o de mat?ria seca e a rela??o l?mina/colmo foram influenciadas pelo intervalo de aplica??o dos adubos. J? no experimento 2, o n?mero total de folhas, o n?mero de folhas expandidas, o n?mero de folhas mortas e o comprimento laminar acumulado foram influenciados pelo intervalo de forma linear negativa, enquanto a produ??o de mat?ria seca apresentou resposta quadr?tica ao aumento do intervalo de aduba??o. Nas condi??es estudadas, conclui-se que a cv. Marandu apresenta maior n?mero de folhas e de perfilhos que a cv. Xara?s, que, por sua vez, apresenta maior altura, produ??o de mat?ria seca, rela??o l?mina/colmo e produ??o da rebrota??o. A aplica??o dos adubos nitrogenado e pot?ssico imediatamente ap?s o corte apresenta melhores resultados para as caracter?sticas estruturais, exceto para n?mero de folhas mortas. A produ??o de mat?ria seca por vaso e por planta ? maximizada com a aduba??o entre quatro e cinco dias ap?s o corte.
Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Produ??o Vegetal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2009.
ABSTRACT The objective was to evaluate the effect of differents intervals of N and K2O application after the cut in the structural and productives characteristics of the cultivars Marandu and Xara?s of Brachiaria brizantha. Two experiments mere conducted in a greenhouse, in a 4x2 factorial scheme, in a randomized block design with four repetitions. In experiment one, after the plants thinning in the vases, were applied weekly dosage of 50 mg dm-3 of N and K2O, until one week before the standardized cut, in total of four applications, and after the cut, were applied doses of 50 mg dm-3 of N and of K2O, in the intervals 0; 3; 6 and 9 days, been the cultivars evaluated with 44 days of regrowth. In experiment two, were applied unique dose of 50 mg dm-3 of N and of K2O, one week before the standardized cut and, after the cut were applied 100 mg dm-3 of N and of K2O in the intervals 0; 4; 8 and 12 days, evaluating the cultivars with 39 days of regrowth. In experiment one, only the dry material production and the relation leaf-stem were influenced for the intervals of fertilizer application. Already in the experiment two, total number of leaves, number of expanded leaves, number of dead leaves and accumulated laminar length were influenced for the interval in a negative linear form way, while the dry material production presents a quadratic answer to adubation intervals increase. In studied conditions, the conclusion is that cultivar Marandu presents bigger number of leaves and of tillers than the cultivar Xara?s, that presents bigger height, production of dry material, relation leaf-stem and regrowth production. The nitrogen fertilizer and potassium application immediately after the cut presents better results for the structural characteristics, except for number of dead leaves. The dry material production per vase and per plant is maximized with the adubation between four and five days after the cut.
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Seelam, Uma Maheswara. "STRUCTURAL CHARACTERIZATION OF SPUTTER-DEPOSITED SS304+XAL (X = 0, 4, 7 AND 10 WT.%) COATINGS AND MECHANICALLY MILLED TI, ZR AND." Doctoral diss., University of Central Florida, 2010. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3527.
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Study of the metastable phases obtained by non-equilibrium processing techniques has come a long way during the past five decades. New metastable phases have often given new perspectives to the research on synthesis of novel materials systems. Metastable materials produced by two non-equilibrium processing methods were studied for this dissertation- 304-type austenitic stainless steel (SS304 or Fe-18Cr-8Ni)+aluminum coatings produced by plasma enhanced magnetron sputter-deposition (PEMS) and nanocrystalline Ti, Zr and Hf powders processed by mechanical milling (MM). The objective of the study was to understand the crystallographic and microstructural aspects of these materials. Four SS304+Al coatings with a nominal Al percentages of 0, 4, 7 and 10 wt.% in the coatings were deposited on an SS304 substrate by PEMS using SS304 and Al targets. The as-deposited coatings were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and three-dimensional atom probe microscopy (3DAP). Surface morphology and chemical analysis were studied by SEM. Phase identification was carried out by XRD and TEM. The microstructural features of all the coatings, as observed in the TEM, consisted of columnar grains with the columnar grain width (a measure of grain size) increasing with an increase in the Al content. The coatings had grains with average grain sizes of about 100, 290, 320 and 980 nm, respectively for 0, 4, 7 and 10 wt.% Al. The observed grain structures and increase in grain size were related to substrate temperature during deposition. XRD results indicated that the Al-free coating consisted of the non-equilibrium ferrite and sigma phases. In the 4Al, 7Al and 10Al coatings, equilibrium ferrite and B2 phases were observed but no sigma phase was found. In 10Al coating, we were able to demonstrate experimentally using 3DAP studies that NiAl phase formation is preferred over the FeAl phase at nano scale. During mechanical milling of the hexagonal close packed (HCP) metals Hf, Ti and Zr powders, unknown nanocrystalline phases with face centered cubic (FCC) structure were found. The FCC phases could be either allotropes of the respective metals or impurity stabilized phases. However, upon MM under high purity conditions, it was revealed that the FCC phases were impurity stabilized. The decrease in crystallite size down to nanometer levels, an increase in atomic volume, lattice strain, and possible contamination were the factors responsible for the transformation.Ph.D.
Department of Mechanical, Materials and Aerospace Engineering;
Engineering and Computer Science
Materials Science & Engr PhD
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KENTZINGER, EMMANUEL. "Ordre et mobilite atomique dans les alliages cubiques centres : diffusion de neutrons dans fe#1#-#xal#x et simulations monte-carlo." Université Louis Pasteur (Strasbourg) (1971-2008), 1996. http://www.theses.fr/1996STR13113.
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Pour comprendre l'interdependance de l'ordre et de la mobilite atomique dans les alliages et composes intermetalliques ordonnes sur un reseau cubique centre (phases b2 et do#3), une etude experimentale de l'ordre local et des enthalpies de migration par diffusion diffuse et inelastique de neutrons a ete entreprise dans le systeme fe#1#-#xal#x en fonction de la concentration (x = 0. 2, 0. 25, 0. 3) et de la temperature (300 k a 1373 k). Pour modeliser cette interdependance, des simulations monte carlo (mc) des cinetiques de mise en ordre a longue distance ont ete effectuees dans les phases b2 et do#3. Les energies d'interaction de paires effectives (eip) ont ete obtenues dans fe#7#5al#2#5 a 1373 k par une analyse dans l'espace reciproque de l'intensite de diffusion diffuse due a l'ordre a courte distance suivant la methode de variation des amas. La valeur obtenue pour l'eip entre premiers voisins sera un des parametres d'entree du modele mc developpe pour la structure do#3. Les enthalpies de migration (h#m) ont ete deduites de la determination des spectres de phonons. Elles decroissent avec la concentration (minimum a la stoechiometrie fe#3al) et la temperature, mais semblent peu sensibles a l'etat d'ordre. L'effet de l'ordre sur h#m n'apparait clairement que lors d'une discussion comparative dans le cadre du modele monte carlo des valeurs de h#m pour deux composes fe#3al et fe#3si de stabilites differentes. Ce modele, qui montre une forte contribution des eip a l'enthalpie de migration tant dans la phase b2 que do#3, contribution d'autant plus elevee que la concentration de lacunes est faible, permet en outre d'interpreter d'autres resultats experimentaux tels que l'augmentation de l'enthalpie d'activation (h#a) de la diffusion avec la mise en ordre b2 dans les alliages feco ou fe#3al ou encore la decroissance de h#a avec les ecarts a la stoechiometrie dans feal b2
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Seelam, Uma Maheswara Rao. "Structural characterization of sputter-deposited SS304+xAl (x = 0, 4, 7 and 10 wt.%) coatings and mechanically milled Ti, Zr and Hf powders." Orlando, Fla. : University of Central Florida, 2010. http://purl.fcla.edu/fcla/etd/CFE0003161.
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HANNA, BAKRAJI ELIAS. "Etude de la position des atomes d'oxygene dans le reseau de ga#1#xal#xas prepare par epitaxie en phase vapeur a partir d'organometalliques." Paris 11, 1990. http://www.theses.fr/1990PA112074.
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Nous avons etudie la localisation de l'impurete oxygene dans des couches minces de ga#1##xal#xas preparees par epitaxie en phase vapeur a partir de composes organometalliques (arsine, trimethylaluminium, trimethylgallium). La concentration totale en oxygene a ete mesuree par activation avec des helions 3 d'energie 3 mev et suivant la reaction nucleaire #1#6o(#3he,p)#1#8f. Cette concentration varie entre quelques ppm (en poids) et quelques dizaines de ppm; elle augmente avec le pourcentage d'aluminium dans la couche. A pourcentage d'aluminium fixe, elle ne varie que peu avec le debit d'arsine. La position des atomes d'oxygene dans le reseau de ga#1##xal#xas a ete determinee en combinant l'activation par les helions 3, avec la canalisation de ces particules dans le reseau cristallin de la couche. Nous avons observe qu'a concentration d'aluminium fixee, la proportion d'atomes d'oxygene en position interstitielle augmente avec le de it d'arsine et qu'a debit d'arsine fixe, elle augmente avec la concentration totale en oxygene. Ce phenomene est explique en faisant l'hypothese que l'oxygene se place d'abord sur des sites d'arsenic inoccupes (cas d'un faible debit d'arsine). Ensuite, ce sont les sites interstitiels qui sont occupes par l'oxygene. Enfin, une methode experimentale de mesure des pouvoirs d'arret en canalisation a ete mise au point. Nous avons montre qu'a 3 mev, la perte d'energie des penetrant dans un reseau cristallin de gaas en posdition aleatoire est superieure d'environ 30% a celle observee avec unc cristal en position de canalisation suivant une direction <100>. Ces resultats restent a exploiter dans de futures experiences combinant canalisation et reactions nucleaires
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PONCE, FARFAN JILBERTO, and J. L. GAUTIER. "Caracterisation physico-chimique et electrochimique des spinelles ni#xal#1#-#xmn#2o#4 prepares par une methode sol-gel et par co-precipitation des sels metalliques." Université Louis Pasteur (Strasbourg) (1971-2008), 1994. http://www.theses.fr/1994STR13210.
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A la difference de l'electrode a hydrogene qui presente une cinetique rapide sur de nombreux substrats, l'electrode a oxygene est un systeme de grande irreversibilite, ce qui conduit a une perte de tension excessive dans la cellule. L'electrode a oxygene pose des problemes relevant principalement de la science des materiaux. Les materiaux qui ont ete utilises en tant qu'electrocatalyseurs pour cette electrode sont nombreux. Parmi ceux-ci, on trouve principalement les oxydes mixtes de structure spinelle et perovskite. Afin de mieux comprendre les parametres agissant sur l'activite electrocatalytique de ces oxydes, les spinelles de formule generale ni#xal#1#-#xmn#2o#4 (x=0 ; 0,2 ; 0,35 ; 0,5 ; 0,8 ; 1) ont ete preparees par trois methodes differentes: la coprecipitation des hydroxydes et des oxalates et une voie sol gel utilisant les carboxylates metalliques comme precurseurs. Nous avons constate que les temperatures et les temps de traitement thermique sont inferieurs pour les composes prepares par la methode sol-gel. La caracterisation structurale de cette serie de composes a ete realisee a l'aide de mesures cristallographiques, de conductivite electrique, de degre d'oxydation global, de la spectroscopie infrarouge et de mesures magnetiques. L'ensemble de ces mesures ont permis d'etablir la repartition ionique la plus probable dans les oxydes etudies. Nous avons montre que l'augmentation de la teneur en nickel se traduit par un changement des etats d'oxydation du manganese, par une augmentation des sites actifs et par consequent de l'activite electrocatalytique vis a vis du degagement et de la reduction de l'oxygene. Les composes prepares par la methode sol-gel presentent neanmoins une performance superieure a celle presentee par les composes prepares par coprecipitation
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DELACARTE, VALERIE, and Daniel Vivien. "Cristallogenese et etude spectroscopique de l'aluminate de strontium lanthane sr#1#-#xla#xmg#xal#1#2#-#xo#1#9 (asl) dope nd, cr, nd-cr ou pr. Proprietes laser de l'asl : nd." Paris 6, 1994. http://www.theses.fr/1994PA066543.
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L'asn, sr#1#-#xnd#xmg#xal#1#2#-#xo#1#9 (sr#1#-#xnd#x) est un materiau laser prometteur decouvert recemment. Nous nous sommes interesses a l'asl:nd (sr#1#-#xnd#yla#x#-#y) pour lesquels les taux de strontium et de neodyme, responsables respectivement de la non congruence de la fusion et des proprietes laser, peuvent varier independamment. Les spectroscopies d'absorption et d'emission sont etudiees en fonction de la composition des cristaux synthetises au four a concentration de rayonnement. On assiste a une extinction de la fluorescence due a des interactions fortes entre ions nd#3#+. L'intensite de fluorescence est maximale pour environ 10% de neodyme. Les meilleures compositions sont synthetisees par tirage czochralski. Les cristaux sr#1#-#xnd#yla#x#-#y avec 1-x 0,6 ou 1-x = 0,7 et y 0,1 sont a fusion congruente. Pour les autres compositions, l'ecart a la non congruence est d'autant plus grand que le taux de strontium est eleve et le taux de lanthane faible. Les tests laser en pompage par diode a 796 nm mettent en vedette le cristal sr#0#,#7nd#0#,#1la#0#,#2 pour lequel le rendement differentiel atteint 47%. Un tirage reussi a l'echelle industriel pour la composition sr#0#,#7nd#0#,#1la#0#,#2 permet de dire que l'asl: nd est desormais en phase de developpement. Dans une deuxieme etape, l'etude du chrome dans l'asl: cr revele la presence de 4 sites occupes par cr#3#+, de paires et de triades de chrome. Les cristaux codopes d'asl: nd, cr sont ensuite elabores et on montre l'existence des transferts d'energie cr nd tres efficaces. Ceci laisse prevoir une augmentation forte du rendement de l'emission laser de nd#3#+, en pompage par lampe flash, grace a l'introduction de chrome. Enfin, le cristal de composition sr#0#,#7nd#0#,#1la#0#,#2cr#0#,#0#5 est synthetise par tirage czochralski a l'echelle industrielle. Sa taille et sa qualite permettent de poursuivre ce travail en effectuant des tests laser en pompage par lampe flash. Enfin, les cristaux sr#0#,#7pr#yla#0#,#3#-#y avec y = 0,02 ; 0,05 et 0,10 ont ete synthetises par tirage czochralski et leur proprietes optiques etudiees. Compte tenu des resultats obtenus, on espere observer l'effet laser de l'asl: pr a des longueurs d'onde interessantes en particulier dans le visible
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Doménech, Villa Vicente Ramón. "Gustos y disgustos del Lentiscar de Cartagena (1689), de Ginés Campillo de Bayle. Estudio y edición crítica." Doctoral thesis, Universidad de Alicante, 2017. http://hdl.handle.net/10045/73411.
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En la segunda mitad del siglo XVII, el clérigo ilicitano Ginés Campillo de Bayle (Elx, ca. 1640 — id., 19 de abril de 1711), desarrolló su labor literaria en el campo de la poesía, el teatro y la narrativa, al mismo tiempo que desempeñaba sus funciones eclesiásticas. Durante más de tres siglos, tanto el autor como su obra han permanecido casi ignorados, a pesar de encontrar referencias a ambos en numerosas publicaciones. Ginés Campillo de Bayle es el reflejo y ejemplo de una época de la literatura catalana en lengua castellana, que debe ser recuperada y tenida en cuenta dentro de un contexto determinado. El valor y riqueza literaria de estas aportaciones queda en la actualidad fuera de cualquier duda o prejuicio. Este trabajo intenta, por un lado, estudiar la figura y la obra de Ginés Campillo de Bayle y, especialmente, su novela más conocida, Gustos y disgustos del Lentiscar de Cartagena (Valencia, 1689), de la que se realiza, también su primera edición crítica. Contextualizada en una época concreta, en la que Ginés Campillo de Bayle forma parte de una extensa nómina de escritores con características semejantes, se recupera la obra para realizar un análisis profundo que refleja una recepción e influencias procedentes de uno de los períodos más destacados y significativos de las literaturas hispánicas: el Siglo de Oro castellano. A través de la obra de Ginés Campillo de Bayle no solo es posible asistir a un ejemplo y modelo de características y estilos previos definidos, sino a un completo paseo por un amplio abanico de influencias, tamizados a través de su particular filtro y su peculiar óptica, que hacen de esta obra un buen ejemplo de la literatura cortesana de las tierras hispánicas en el siglo XVII.
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Taravel, Condat Carol. "Influence des conditions d'élaboration sur la microstructure de solidification lors de la trempe sur roue d'alliages Fe₇₅Al₂₅ et Fe₍₇₅-ₓ₎Al₂₅Bₓ₍₀, ₀₅₋₁₎ (pds%)." Grenoble INPG, 1991. http://www.theses.fr/1991INPG0106.
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Les mécanismes de solidification dans les alliages Fe#7#5Al#2#5 et Fe#7#5#-#xAl#2#5B#x#(#0#,#0#5#-#1#) (pds%) élaborés par trempe de coulée plane sur roue sont analyses, nous dégageons l'influence des paramètres d'élaboration sur la microstructure finale des rubans (taille et forme des grains, structure dendritique, texture). Les structures de solidifications sont interprétées a l'aide d'un modèle thermique simulant le refroidissement et la solidification des alliages Fe#7#5Al#2#5 dans la flaque; entre autre, nous étudions avec précision les contributions du coefficient de transfert thermique sur la germination, la recalescence, et la déstabilisation du front de solidification. Par ailleurs, des mesures pyrométriques réalisées a la surface des rubans pendant la trempe ainsi qu'une étude de recuits a hautes températures, expliquent l'influence de l'atmosphère sur la microstructure finale des rubans, les rubans élaborés sous vide subissant une importante croissance des grains a l'état solide dans l'atmosphère de trempe des leur décollement de la roue. De façon générale, les rubans présentent une zone de grains equiaxes cote roue surmontée d'une couche de grains colonnaires débouchant cote libre. L'épaisseur de la zone équiaxe par rapport a celle de la zone colonnaire augmente avec l'épaisseur du ruban et diminue quand on rajoute du bore. Ces résultats sont discutes a l'aide du modèle théorique
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Bagudanch, Frigolé Isabel. "Incremental sheet forming applied to the manufacturing of biocompatible polymer prostheses." Doctoral thesis, Universitat de Girona, 2017. http://hdl.handle.net/10803/461838.
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Incremental Sheet Forming (ISF) technology has been mainly applied on metallic sheets during the last years. ISF is used due to its flexibility, low costs, low batch production, production of complex geometries and customized prodcuts. For this reason ISF seems to be the ideal process for prosthesis production.
The main objective of the thesis is to study the ISF technology, considering Single Point Incremental Forming (SPIF) and Two Point Incremental Forming (TPIF) variants, on biocompatible polymers to obtain a real customized cranial implant. The methodology is based on the following steps: a) Experimental work in SPIF to produce basic geometries using non-biocompatible and biocompatible polymers, b) Study of the influence of the process parameters, c) Case study: customized cranial implant. Achieving the objectives established in these stages will permit to improve the knowledge about ISF process in order to successfully manufacture customized implants at a low cost and reduced time-to-marketLa tecnologia de deformació incremental de xapa (ISF) s’ha aplicat majoritàriament en metalls durant els últims anys. Aquesta tecnologia es caracteritza per la flexibilitat del procés amb costos baixos, producció en lots petits, obtenció de geometries complexes i personalització del producte, el que fa que un dels camps d’aplicació de la tecnologia sigui la fabricació de pròtesis. L’objectiu principal és el d’estudiar la tecnologia ISF, en les seves variants de Single Point Incremental Forming (SPIF) i Two Point Incremental Forming (TPIF), sobre polímers biocompatibles per obtenir una pròtesi de crani personalitzada. La metodologia es basa en: a) Experimentació en SPIF de geometries bàsiques utilitzant polímers no biocompatibles i biocompatibles, b) Determinació de la influència dels paràmetres de procés, c) Cas d’estudi: pròtesi de crani personalitzada. L’assoliment d’aquestes etapes permetrà obtenir satisfactòriament pròtesis personalitzades de crani amb un baix cost i un temps de fabricació reduït
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Freeman, Janine Beverly. "The transfer of ideology in the post-independence French African novel: Sembene Ousmanes's Xala in translation." Thesis, 1994. https://hdl.handle.net/10539/24689.
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I declare that this research project is my own unaided work. It is
submitted in partial fulfilment for the degree of Master of Arts in
translation, at the University of the Witwatersrand, Johannesburg, It has
not been submitted before for any degree or examination at any other
university.This projeot examines Clive Wake's translation of Xala a neo-colonial French African novel by Sembene Ousmane' (1973) focusing on the manner in which the ideological content of the novel is approached and dealt with in translation. A comparison of passages in the source text chosen on the basis of their ideological contribution to the novel with the corresponding passages in this large text, forms the basis of the study. (Abbreviation abstract)
Andrew Chakane 2018
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Gachanja, Peter Mwaura. "Sembene se révolte contre la corruption politique une étude du Mandat, Xala et Le dernier de l'Empire /." 2009. http://purl.galileo.usg.edu/uga%5Fetd/gachanja%5Fpeter%5Fm%5F200908%5Fma.
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Babatunde, Samuel Olufemi. "Engagement et militantisme dans le Docker Noir (1956), les Bouts de bois de Dieu (1960) et Xala (1973) de Sembène Ousmane." Thesis, 2015. http://hdl.handle.net/10500/19617.
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Text in FrenchMember of the union of black workers in the port of Marseille, in France, and an eyewitness to the misery of black workers in the European environment, Sembène Ousmane, in 1956, wrote, using his personal experiences, his first book entitled The Black Docker. In this novel, he describes the sufferings of the working class, the struggle between colonisers and colonised. In 1960, he uses as a pretext the strike of the Senegalese railway workers in 1937 to write a book entitled God's Bits of Wood. In this story where two forces clashed, on one hand, the colonised struggling against the colonial system and want, at all costs, to improve their living conditions, and on the other hand, the colonisers that are in support of their colonialist ideals and refuse the changes, the author tells the epic story of strikers in Senegal and their relentless struggles against the colonisers to change their living conditions for better. In 1973, an eyewitness of the daily realities of his native country, Senegal, after gaining national sovereignty, Sembène Ousmane wrote and published a book entitled Xala. In this book, he describes the evils of neo-colonialism and criticises the new African middle class, born after independence. After reading these novels, one notes that Sembène Ousmane, a defender of freedom, denounces the injustices done to the blacks, both in the colonial era as well as in the post colonial period. This is why from a book to another, he continues tirelessly his struggle against colonialism and neo-colonialism, evoking the sufferings and tragedies endured by the Africans. It occurs constantly in his imaginary creations, a theme, or better still a dialectical; commitment and militancy. What does he mean by « commitment » and « militancy » ? How do these two concepts manifest themselves in the works of the Senegalese writer? What strategy does he propose to the oppressed in the struggle against the oppressors? What means has he put at the disposal of the disinherited struggling to break the yoke of oppression and exploitation in order to achieve freedom and equality?
Membre du syndicat des travailleurs noirs, au port de Marseille, en France, et témoin oculaire de la misère vécue par les ouvriers noirs dans ce milieu européen, Sembène Ousmane, en 1956, écrit, en se servant de ses expériences personnelles, son premier ouvrage intitulé Le Docker noir. Dans ce roman, il décrit la souffrance de la classe ouvrière, la lutte entre colonisateurs et colonisés. En 1960, il se sert d’un prétexte, la grève des ouvriers sénégalais en 1937, pour écrire un ouvrage intitulé Les Bouts de bois de Dieu. Dans ce récit, où s’affrontent deux forces, d’une part les colonisés qui luttent contre le système colonial et veulent, à tout prix, l’amélioration de leurs conditions de vie, et d’autre part, les colonisateurs qui soutiennent les idéaux colonialistes et refusent le changement, l’auteur relate l’histoire épique des grévistes au Sénégal, et la lutte implacable qu’ils mènent contre les colonisateurs pour le changement de leurs conditions de vie. En 1973, témoin oculaire des réalités quotidiennes de son pays natal, le Sénégal, après son accession à la souveraineté nationale, Sembène Ousmane écrit et publie, un ouvrage intitulé Xala. Dans ce livre, il décrit les méfaits du néocolonialisme et critique la nouvelle classe bourgeoise africaine, née après l’indépendance. Après lecture des trois romans, on constate que Sembène Ousmane, défenseur de la liberté, dénonce les injustices faites aux Noirs, aussi bien à l’époque coloniale qu’à la période postcoloniale. C’est pourquoi, d’un ouvrage à l’autre, il continue, inlassablement, sa lutte contre le colonialisme et le néocolonialisme, en évoquant les souffrances et les drames endurés par les Africains. Il revient, constamment, dans ses créations imaginaires, à une thématique, ou mieux une dialectique, l’engagement et le militantisme. Qu’entend-il par « engagement » et « militantisme »? Comment ces deux lexèmes se manifestent-ils dans les écrits de cet écrivain sénégalais? Quelles stratégies propose-t-il aux opprimés dans la lutte qui les oppose aux oppresseurs? Quels moyens met-il a la disposition des déshérités en lutte pour briser le joug de l’oppression et celui de l’exploitation afin d’obtenir la liberté et l’égalité?
Linguistics and Modern Languages
D. Litt. et Phil. (French)
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Ntita, Samuel Beya. "Proces d'alienation de l'intellectuel dans les romans sub-Saharaiens Francophones : Xala D'O. sembene, le pacte de Sang de P.N. Nkashama et L'Histoire du fou de M. Beti." Thesis, 2019. http://hdl.handle.net/10500/26668.
Full textAbstract:
Text in French, with abstracts in French and EnglishAu lendemain des indépendances africaines, les écrivains tentent de dénoncer, sinon l’aliénation des intellectuels, du moins ce que le peuple désignait sous ce terme dans les excolonies françaises et belges. Le recours fréquent, dans la construction du récit, à la thématique de la faute de l’intellectuel se présente comme résultat d’un manquement au rôle qui lui revient. Pour mener à bien notre enquête, la théorie utilisée est l’Analyse de contenu thématique (A.C.T.) de Pierre Lannoy. Ce modèle aidera à cerner tout ce qui menace l’équilibre de l’édifice social. Cependant l’étude de l’aliénation des intellectuels a montré que l’émergence d’une crise semblable relève d’une série de causes complexes. Sa compréhension fait appel à de multiples champs scientifiques : sociologie, psychologie, économie, […] La seule solution est le compromis pour tous. C’est une vaine prétention que de vouloir établir ici un bilan exhaustif : l’étude de l’image de l’intellectuel ne peut qu’être évolutive.
In the aftermath of African independence, writers tried to denounce, if not the alienation of intellectuals, at least what people meant by this term in the former French and Belgian colonies. Frequent recourse to the theme of the fault of the intellectual in the construction of the narrative is presented as the result of a failure to fulfil the role that was assigned to him. To carry out our investigation, the theory used is Pierre Lannoy's Thematic Content Analysis (T.C.A.). This model will help to identify anything that threatens the balance of the social edifice. However, the study of the alienation of intellectuals has shown that the emergence of a similar crisis is due to a series of complex causes. Its understanding involves multiple scientific fields: sociology, psychology, economics, [...] The only solution is compromise for all. It is a vain claim to want to establish an exhaustive assessment here: the study of the image of the intellectual can only be evolutionary.
Classics and World Languages
D. Litt. et Phil. (French)
39
Ho, Ping-Long, and 何秉隆. "Superconducting Properties of Novel Superconducters (Mg1-xAlx)B2." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/64360718387589772730.
Full textAbstract:
碩士國立中山大學
物理學系研究所
90
Abstract In the light of the tremendous progress that has been made in raising the transition temperature of the copper oxide superconductors. At present, the highest reported values of Tc for non-copper-oxide bulk superconductivity are 33 K in CsxRbyC60, and 30 K in Ba1-xKxBiO3. The recent discovery of superconductivity at 39 K in the sample binary ceramic compound magnesium diboride, MgB2(ref. 1), was therefore surprising. Indeed, this material has been known and structurally characterized since the mid 1950s, and is readily available from chemical suppliers. Here we try to addition of electrons to MgB2, through partial substitution of Al for Mg and a structural transition in Mg1-xAlxB2
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Chou, Yu-Feng, and 周鈺峰. "Study on High-Temperature Oxidation of (MoSi2)100-XAlX and Ni2TiAl." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/85750260771067636837.
Full textAbstract:
碩士國立臺灣海洋大學
材料工程研究所
102
The oxidation behavior of (MoSi2)90Al10, (MoSi2)80Al20, and Ni2TiAl alloys was studied over the temperature range of 700~ 1200℃ in dry air. The effect of Al addition on high temperature oxidation resistance of MoSi2 was explored. The effect of oxygen partial pressure on the oxidation of Ni2TiAl at 1000℃ was also investigated. The results showed that the oxidation kinetics of (MoSi2)90Al10 and (MoSi2)80Al20 followed a multiple-stage parabolic-rate law at 700~ 1200℃. The parabolic kinetics indicates that ionic diffusion is the rate-determining step during the oxidation. The addition of Al can effectively prevent the volatilization of MoO3 for MoSi2. The scales formed on the alloys consisted mostly of α-Al2O3 and minor SiO2. The oxidation kinetics of Ni2TiAl also followed the parabolic-rate law at 700~ 1200℃, with its oxidation rates gradually increasing with temperature. The scales formed on the alloy at 700~ 800℃ consisted mostly of TiO2, NiTiO3, and Al2TiO3. The α-Ni layer has taken place beneath the scale. In addition, duplex scales formed on the alloy at 900~ 1200℃ consisted of NiO (≧1000℃), TiO2, NiTiO3, and NiAl2O4 in the outer layer, and of TiO2, NiTiO3, NiAl2O4, Al2O3, and metallic α-Ni in the inner layer. α-Ni layer has also taken place beneath the scale. The kp values of the alloy were independent of oxygen partial pressure, indicating that the scaling behavior of the alloy exhibited an N-type semiconductivity.
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Xaba, Nqobile. "Use of amaranth as feedstock for bio-ethanol production / Nqobile Xaba." Thesis, 2014. http://hdl.handle.net/10394/12230.
Full textAbstract:
The depletion of fossil fuel reserves and global warming are the two main factors contributing to the current demand in clean and renewable energy resources. Biofuels are renewable energy resources and have an advantage over other renewable resources due to biofuels having a zero carbon footprint and most feedstock is abundant. The use of biofuels brought about major concerns and these include food, water and land security. The use of lignocellulose as bioethanol feedstock can provide a solution to the food, water and security concerns. Biofuels such as bioethanol can be produced from lignocellulose by breaking down the structure of lignocellulose liberating fermentable sugars. Amaranth lignocellulose has a potential to be used as a feedstock for bioethanol production because amaranth plants has a high yield of biomass per hectare, require very little to no irrigation and have the ability to withstand harsh environmental conditions.
The aim of this study was to investigate the viability of amaranth as a feedstock for bioethanol production by using alkaline assisted microwave pretreatment. Alkaline pretreatment of amaranth using Ca(OH)2, NaOH and KOH at various concentrations (10-50 g kg-1 of alkaline solution in water) was carried out at different energy input (6-54 kJ/g). The pretreated broth was enzymatically hydrolysed using Celluclast 1.5L, Novozyme 188 and Tween 80 at pH 4.8 and 50oC for 48 hours. The hydrolysate was further fermented to ethanol using Saccharomyces cerevisiae at a pH of 4.8 and 30oC for 48 hours. The effect of microwave pretreatment on amaranth lignocellulose was evaluated using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The monomeric sugars and ethanol were quantified using high performance liquid chromatography (HPLC).
A maximum sugar yield of 0.36 g/g of biomass was obtained for pretreatment with 30 g kg-1 Ca(OH)2 solution in water, 0.24 g/g of biomass was obtained for pretreatment with 50 g kg-1 NaOH solution in water and 0.21g/g of biomass was obtained for pretreatment with 50 g kg-1 KOH solution in water at 32 kJ/g of energy input. After enzymatic hydrolysis the yields increased to 0.43 g/g, 0.63 g/g and 0.52 g g-1 of biomass for Ca(OH)2 , KOH and NaOH pretreated biomass respectively. The highest ethanol yield obtained was found to be 0.18 g/g of biomass from fermentation of KOH pretreated broth. The ethanol yield obtained from fermentation of Ca(OH)2 and NaOH pretreated broth was 0.13 g/g of biomass and 0.15 g/g of biomass respectively. The results showed that an increase in concentration of alkaline solution and an increase in energy input liberate more sugars. A decrease in biomass loading was found to increase the total sugar yield. Pretreatment with KOH was found to liberate
more pentose sugars than the other alkaline solutions. The morphological changes shown by
the SEM images showed that microwave irradiation is effective in breaking the structure of
amaranth lignocellulose. The structural changes shown by the FTIR also validated that
alkaline bases were effective in breaking the lignin, cellulose and hemicellulose linkages and
liberating more sugars in the process. This work has demonstrated the enormous potential
that amaranth lignocellulose has on being a feedstock for bioethanol production.MSc (Engineering Sciences in Chemical Engineering), North-West University, Potchefstroom Campus, 2014
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CHUAN, LIU KUN, and 劉坤泉. "Low Temperature Specific Heat in Sm2-yCeyCuO4 and V1-xAlx System." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/12039182190357647016.
Full textAbstract:
碩士國立中正大學
物理系
89
We had measured the electronic specific heats, gT=(π2/3)κ2BN(EF)T，for V1-xAlx (x=0.18，0.20，0.22，0.24，0.26) alloys at liquid-helium temperatures to deduce the elcetron-phonon enhanced electronic density of states at Fermi level N(EF).The values of D were then obtained through the Einstein relation 1/ρ0=De2N(0)/(1+λ) ，whereρ0 was the measured resistivity,and the e-ph coupling constantλ~0.46(Ref.4) was used. Antiferromagnetic ordering of the rare-earth ions in Sm2CuO4 has been found (TN~5.9 K).For Sm1.85Ce0.15CuO4+d(d=0.07) TN is lowered to be~4.6 K, and Sm1.85Ce0.15CuO4+d(d=-0.03) TN~4.7 K. For Sm1.85Ce0.15CuO4+d(d=-0.03) the magnetic entropy saturates rapidly above TN to be ~1.85Rln2,indicating that the Sm+3 ions are substituting by Ce+4 ions.
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Cheng-YuWang and 王程鈺. "NMR investigation of electronic properties in the Heusler-type compounds Ru2VGa1-xAlx." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/u2v44h.
Full textAbstract:
碩士國立成功大學
物理學系
104
SUMMARY We report the results of a 51V Nuclear Magnetic Resonance (NMR) study on the Heusler-type compounds Ru2VGa1-xAlx (x=0, 0.25, 0.5, 0.75, 1). Ru2VGa crystallizes in the L21 structure, and Ru2VAl crystallizes in the B2 structure. All materials of the series sample possess high electrical resistivity as compared to ordinary metals. The temperature-dependent NMR spin-lattice relaxation rates 1/T1 for all materials follow a Korringa relation, indicative of metallic behavior. From the analysis of experimental 1/T1 data, we extract the V 3d partial Fermi-level density of states (DOS) for each individual compound. The obtained results indicate a small DOS at around the corresponding Fermi level for all samples of Ru2VGa1-xAlx. We also compare the experimental results with the theoretical electronic structures revealed from recent band structure calculations. Key words: Nuclear Magnetic Resonance, Heusler-type, relaxation, Korringa realation INTRODUCTION In 1903 Heusler-type intermetallic compounds, also called Heusler alloys, began to attract attention when Germany chemist Friedrich Heusler discovered a ferromagnetic compound Ru2MnSn which is synthesized by three non-magnetic elements, Ru, Mn and Sn. The generic formulas of Heusler-type alloys are X2YZ or XYZ. X2YZ is called full Heusler alloy and crystallizes in the L21 structure, while XYZ is called semi-Heusler alloy and crystallizes in the C1b structure. Compared to X2YZ, XYZ is formed by removing one of the X sites. X and Y atoms are transition metals, while Z atoms are the elements of groups IIIA~VA. The properties of these compounds are very wide, including metals, semiconductors and semimetals. Many Heusler alloys have potential to be thermoelectric materials, so these alloys attract much attention recently. The theoretical electronic properties of Ru2VGa1-xAlx were calculated by first principle density functional theory in a paper. And this paper indicated that the Fermi-level density of state (DOS) is dominated by Ru-d electrons and V-d electrons and the DOS are small for every samples. We used NMR technique to measure the properties of Ru2VGa1-xAlx. MATERIALS AND METHODS All samples were prepared by an arc-melting method and then annealed under 800 ºC for three days. Room temperature X-ray diffractions (XRD) on the powder Ru2VGa1-xAlx samples are displayed in Fig. 1. Ru2VGa crystallizes in the L21 structure while Ru2VAl in the B2 structure. Each XRD shows a single phase and all reflection peaks in the diffraction spectrum are in agreement with the corresponding structure. It is clear in Fig. 2. that the lattice parameter decreases with the Al concentration, indicative of a successful replacement between Ga and Al atoms in this series of samples. RESULT AND DISCUSSION Figure 4 shows the 51V NMR central transition line of each component. We determined the Knight shift from the peak position of each spectrum. The evolution of the 51V NMR Knight shift exhibits an opposite trend of the spin-lattice relaxation rate 1/T1T, as demonstrated in Fig. 5. This result suggests that both variations essentially arise from the change of the V-3d electronic states since the hyperfine field association with the core polarization via 3d electrons is negative. CONCLUSION From the analysis of 1/T1T, we can deduce the V-3d partial Fermi-level density of states with the results shown in Fig. 5. It is noted that our NMR results for the V-3d electronic states of Ru2VGa1-xAlx are quite consistent with those obtained from the theoretical band structure calculations.
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Po-HsunWang and 王柏勛. "Comparative NMR study of local electronic properties of XAl4 (X=Sr,Ba) intermetallics." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/87354836090301093212.
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Chi, Chang Kai, and 張凱棋. "Phase Transformation and Thermoelectric Performance of p-type FeSi2-XAlX Prepared by VAR." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/78709954171999297848.
Full textAbstract:
碩士國立中興大學
材料工程學研究所
93
Abstract In this study, we have prepared the bulk materials of p-type FeSi2-XAlX by means of Vacuum Arc Remelting (VAR). The materials subsequently were heat treated at 800℃ for various times to make them transfor into semiconducting β phase. The Composition, Phase transformation and thermoelectric properties were characterized by means of Inductively Coupled Plasma-Mass Spectrometer (ICP-MS), Electron Probe X-Ray Micro-Analyzer (EPMA), Differential Thermal Analysis (DTA), X-Ray Diffraction (XRD), Field-Emission SEM (FE-SEM) and thermoelectric measurement system, respectively. Shown by ICP-MS result, the mole ratio value of Si is less than the composition planned originally, so we added excess 4 wt% Si to all of the samples prepared. The results in DTA,XRD and FE-SEM, show that the heat treatment time for the appearance of β phase increases with increasing the content of Al-doped. The reason is that the reaction rates of both pertectoid and eutectoid reactions are slowed down due to the effect of lowering pertectoid and eutectoid temperature with Al dopant. It is evident that preferred orientation arises in the direction (2 0 0) at 2θ＝69.76° with Al-dopant. About the thermoelectric properties, the optimum figure of merit Z＝2.6*10-5(K-1) is composed of thermoelectric power S＝87.03（μV/K）, electrical resistivity ρ＝9.02*103（μΩ㎝） and thermal conductivity κ＝3.24（W/mK）, which was obtained in FeSi1.985Al0.015 after 16 hours 800℃ heat treatment. Because pure FeSi¬2 is an intrinsic semiconductor, the higher electrical resistivity was due to the lower carrier concentration and the higher energy gap. And the other sample which were doped with higher Al content. Possess lower values of the figure of merit than FeSi1.985Al0.015, because the transformation rate of β phase is too slow to obtain a better thermoelectric property within 16 hours.
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Senong, Doctor Kolodi. "Sofaya in paint: representations of human dignity in the work of Sekoto, Xaba and Mthethwa." Thesis, 2016. http://hdl.handle.net/10539/21885.
Full textAbstract:
A Research Report to the Faculty of Humanities, University of the
Witwatersrand, Johannesburg, in fulfillment of the requirements for the
degree of Master in Arts (Fine Art), 2016The core of the study for this MA examines expressions and understandings of human dignity/seriti, in the work of Gerard Sekoto (1913-1993), Nhlanhla Xaba (1960-2003), Zwelethu Mthethwa (b.1960) and in my own paintings. As such, the study probes, analyses and questions the intentions, writings on and readings of these artists’ work, as well as appropriate and build on their visual and representational languages. Underlying the research is the idea of black consciousness, and quest for an ideology of a more human and equal South Africa. The subject of my paintings evolves around seriti in Sofaya, an informal settlement in the northeast of Johannesburg, which is not located on official maps of the city. I set out this study with the argument, that all human beings retain seriti as a quality that bestows respectability and equality to them. The practical component is comprised of paintings in oil. The work tries to capture a personal and spiritual quality that I call seriti through explorations of colour, paint mark, and texture. I am curious about the concept of seriti as seen through everyday experiences. I am moved by the imaginative ability of both Sekoto and Xaba’s images that weave communal and socio-political narratives to portray, positively, people’s capacity to outlive harsh and conflicting living conditions. As a result of these influences, I employ dynamic brushwork, poetic colours, and expressive forms in an attempt to portray the realities, agency, and the place of Sofaya.
MT2017
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Shian, Lin Tzung, and 林宗賢. "The Effects of Al Substitution on the Hydrogenation Properties and Microstructures of LaNi5-xAlx Alloys." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/14690691909481982442.
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Jung, De-Ru, and 鍾德儒. "Influence of Se molecule structure on the microstructure of Cu(In1-xAlx)Se2 thin films." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/48577537702898105436.
Full textAbstract:
碩士國立中興大學
材料科學與工程學系所
100
Thin film solar cells based on the compound semiconductor CuInSe2 (CIS) have been proven to be a promising material with high absorption coefficient 3.6×105 cm-1. Also, it can be modified near surface defects and related junction properties. Up to now, it is demonstrated Cu(In,Ga)Se (CIGS) solar cells by three-stage evaporation with record high 20.3% efficiency at the Zentrum fuer Sonnenenergie und Wasserstoff-Forschung (ZSW). However, we must overcome challenge that is to combine low-cost and high efficiency requests on a large-scale for industrial application. Indeed, most of the researches prefer two-stage selenization and non-vacuum technology such as electrodeposition and ink. Among the method mentioned above, sputter-selenization is most widely used because its reproducible quality. CuAl/In precursor films with varying Cu/(In + Al) ratios were sequential-sputtered onto soda-lime glass substrates and subsequently selenium layer was deposited under high vacuum using thermally evaporated solid selenium. We then studied structural influence of CuIn1-xAlxSe thin films fabricated by selenization under over-pressure of selenium in a graphite box, specifically, the effect on the crystallinity of CIAS, which can be controlled by slenization parameters such as heating rate, annealed time and temperature. Besides, in accordance with these selenization conditions, the reaction pathways and phase evolution of the staked CuAl/In/Se precursors during CIAS formation were examined by X-ray diffraction and Raman spectrograph. It is concluded that the influence of heating rate and temperature on crystallization rate and diffusion rate for Se in the second stage. That is, the reaction pathways of selenide were not constant. In contrast, there are excessive CuxSe phase when temperature was increased to 350 and 550oC. CIAS thin films of different preferred orientations were obtained by varying the heating rates.
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CHI-WEN, WANG, and 王祺文. "A Study ofα, B2 and D03 Phases in Fe-10Mn-xAl Alloys." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/44913325111817655101.
Full textAbstract:
碩士國立臺灣科技大學
機械工程系
93
ABSTRACT The object of this thesis is to study the phase transformations between , B2 and D03 phases in Fe-Mn-Al alloys with fixed 10 wt.% Mn. The constituents of Al in the Fe-Mn-Al alloys are 7.9, 10.6, 12.0, 13.4 and 14.9 wt.%. The alloys were heated at 1000℃ for the solution treatment, and than aged at lower temperatures for the growth of the B2 and D03 phases. For the Fe-10Mn-7.9Al alloy, the upper limit for the existence of the D03 phase is between 450 and 475℃. For the Fe-10Mn-10.6Al alloy, that of the D03 phase is higher and between 525 and 540℃. The mechanism of the formation of the D03 phase is the traditional nucleation and growth of the D03 phase in the BCC matrix, i.e. α→α＋D03. No B2 phase was observed in the above two alloys. For the Fe-10Mn-12.0Al alloy, we observed B2 and D03 phases in the aging process. The upper limit for the existence of the B2 phase is between 650 and 700℃, and that of D03 phase is between 575 and 600℃. We found the upper limit for the existence of the B2 phase is between 800 and 850℃, and that of D03 phase is between 575 and 600℃ in the Fe-10Mn-13.4Al alloy. However, in the single phase region of D03 phase, the B2 and D03 phases grew at the same time during aging. The growth of D03 phase is reasonable, but it is quite mysterious for the growth of B2 phase in the single D03 phase region. We observed the upper limit for the existence of the B2 phase is between 900 and 950℃, and that of D03 phase is between 575 and 600℃ in the Fe-10Mn-14.9Al alloy. The mechanism for the formation of the B2 phase in the BCC matrix of the Fe-Mn-Al alloys is continuous ordering:α→B2→D03. The addition of the Mn had the effect to increase the upper limit temperature of the two-phase region, α＋D03, found in the Fe-Al alloys. We observed the precipitation of the L12 phase in the BCC matrix. The L12 phase is an Fe3AlC carbide in the Fe-Al-C system. The precipitation of the L12 phase indicated that the low carbon contents of the Fe-Mn-Al alloys could not prohibit the formation of the carbide. It is beyond the solubility limit of the carbon during the low-temperature aging. Therefore, the Fe(Mn)Al-carbide formed during the aging processes in the Fe-Mn-Al alloys.
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Shih, Fu-Yueh, and 施甫岳. "The Synthesis and Characterization of Magnetoplumbite-type Sr(Ga1-xAlx)12O19:R ( R = Eu3+ , Tb3+ , Cr3+ , Mn2+ ) Phosphors." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/37258061651739419558.
Full textAbstract:
碩士國立交通大學
應用化學系
87
This research is attempted to investigate the effect of host compositions, activator concentration, crystal structure, and temperature on the luminescent properties of magnetoplumbite-type Sr(Ga1-xAlx)12O19: R ( R = Eu3+ , Tb3+ , Cr3+ , Mn2+ ; 0 ≦x≦1.0) ( SGAO:R ) phosphors. The SGAO:R phases with R = Eu3+ , Tb3+ , Cr3+ , Mn2+ ) were prepared at 1,400℃ in the air via solid-state route, whereas the formation of SGAO:Mn2+ requires additional annealing under H2/Ar atmosphere at 1,000℃. The lattice dimensions of Sr(Ga1-xAlx)12O19: R were found to shrink gradually with increasing content of Al3+ dopant, as indicated by X-ray diffraction analysis. In addition, SrGa12O19 was found to be self-activating with emission wavelength (λem) of 429 nm, whereas SrAl12O19 is not, as indicated by cathodoluminescence (CL) measurements. On the other hand, with shrunk lattice dimensions the λem corresponding to 2E →4A2 transition in Sr(Ga1-xAlx)12O19:Cr3+ exhibited blue shift, whereas that corresponding to 4T1→6A1 transition in Sr(Ga1-xAlx)12O19:Mn2+ exhibited red shift. These observation can be rationalized by Tanabe-Sugano diagrams for octahedral Mn2+ and Cr3+ ions , respectively. On the contrary, theλem attributed to Sr(Ga1-xAlx)12O19:Eu3+ or Tb3+ phosphors remains unchanged with expanded lattice dimensions. Furthermore, we have also investigated the effect of activator concentration on the luminescent properties of SrM12O19:Eu3+ or Tb3+ ( M = Al, Ga ) and the optimal concentration was found to be 10 and 3 atom % for phases with Eu3+ and Tb3+ dopants, respectively. Theλem of typical R-lines of Cr3+ in SrM12O19: ( M = Al, Ga) has been determined to be 692.6 and 694.2 nm, respectively, and that attributed to 4T1→6A1 transition observed in SrGa12O19: Mn2+ was found to be 503 nm and highly dependent on the temperature, as indicated by temperature dependent photoluminescence (PL) emission studies. The PL and CL emission spectra of MgGa2O4: M ( M = Eu3+ , Tb3+ , Mn2+ ) phases were also investigated in this research.