Made available in DSpace on 2014-12-17T15:41:40Z (GMT). No. of bitstreams: 1 AnaCPC.pdf: 1447913 bytes, checksum: 8f65c2f6df911f6db297163eb551fb69 (MD5) Previous issue date: 2008-02-29 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The metalic oxides have been studies due to differents applications as materials semiconductor in solar cells, catalysts, full cells and, resistors. Titanium dioxide (TiO2) has a high electric conductivity due to oxygen vacancies. The Ce(SO4)2.2H2O doped samples TiO2 and TiO2 pure was obtained sol-gel process, and characterized by X-ray diffractometry,thermal analysis, and impedance spectroscopy. The X-ray diffraction patterns for TiO2 pure samples shows at 700?C anatase phase is absent, and only the diffraction peaks of rutile phase are observed. However, the cerium doped samples only at 900?C rutile in the phase present with peaks of cerium dioxide (CeO2). The thermal analysis of the TiO2 pure and small concentration cerium doped samples show two steps weight loss corresponding to water of hydration and chemisorbed. To larger concentration cerium doped samples were observed two steps weight loss in the transformation of the doped cerium possible intermediate species and SO3. Finally, two steps weight loss the end products CeO2 and SO3 are formed. Analyse electric properties at different temperatures and concentration cerium doped samples have been investigated by impedance spectroscopy. It was observed that titanium, can be substituted by cerium, changing its electric properties, and increased thermal stability of TiO2 anatase structure / Os ?xidos met?licos t?m sido muito estudados devido suas diversas aplica??es como materiais semicondutores em c?lulas solares, catalisadores, c?lulas combust?veis e resistores. O Di?xido de Tit?nio possui uma alta condutividade el?trica devido ?s suas vac?ncias de oxig?nio. Amostras de TiO2 puro, obtidas pelo m?todo sol-gel e dopadas com solu??es de Ce(SO4)2.2H2O, foram analisadas atrav?s de difratometria de raios-X, an?lise t?rmica e espectroscopia de imped?ncia. Atrav?s dos difratogramas de raios-X observou-se a transi??o completa das fases anat?sio-rutilo, para a amostra do TiO2 puro a partir de 700?C. Entretanto, para as amostras dopadas, essa transi??o s? ? completa a partir de 900?C, aparecendo picos correspondentes ao ?xido de c?rio. Atrav?s da an?lise t?rmica se observou uma perda de massa, para o TiO2 puro e dopado com a menor concentra??o de c?rio, correspondente ? desidrata??o e a ?gua quimissorvida. Para as amostras dopadas em uma maior concentra??o, foram observados dois est?gios de perda de massa, devido a decomposi??o do dopante em intermedi?rios e SO3. Essas amostras apresentaram mais duas perdas de massa devido a forma??o do CeO2 e SO3. A partir da espectroscopia de imped?ncia analisou-se as propriedades el?tricas das amostras em fun??o da temperatura de calcina??o e em fun??o da concentra??o do dopante. Tamb?m foi observado que o c?rio, por ter a capacidade de substituir o tit?nio na sua estrutura cristalina, modifica suas propriedades el?tricas e tem o poder de estabiliz?-lo termicamente em certas temperaturas

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第21096号 / 工博第4460号 / 新制||工||1693(附属図書館) / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 高岡 昌輝, 教授 田中 宏明, 准教授 大下 和徹 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

No / To analyze the fatty acid contents of Buddleja asiatica Lour, both the non-volatile oil and fat obtained from the n-hexane soluble sub-fraction were subjected to GC/MS using BSTFA (N,O-bis(trimethylsilyl) trifloroacetamide) derivatization. The oil showed the presence of six fatty acids including palmitic acid (46.75 %), linoleic acid (37.80 %), stearic acid (10.98 %), arachidic acid, margaric acid and lignoceric acid (< 3 %). Analysis of the fat revealed nine fatty acids including lignoceric acid (43.12 %), behenic acid (26.39 %), arachidic acid (9.29 %) and stearic acid (5.3 %). Cerotic acid, montanic acid, melissic acid and palmitic acid were found in low amounts (< 5 %) while trycosylic acid (4.83 %) was the only fatty acid with odd number of carbon atoms. The oil showed a low thermal stability. / Higher Education Commission Pakistan

Submitted by Angela Maria de Oliveira (amolivei@uepg.br) on 2018-11-06T17:35:07Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Geisa Liandra.pdf: 3414564 bytes, checksum: b9fc4d1a56d56c9c5c38f3f88871810e (MD5) / Made available in DSpace on 2018-11-06T17:35:07Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Geisa Liandra.pdf: 3414564 bytes, checksum: b9fc4d1a56d56c9c5c38f3f88871810e (MD5) Previous issue date: 2017-02-09 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Araucaria angustifolia (Bert.) O. Kuntze é uma conífera presente nas florestas brasileiras e as suas sementes apresentam alto teor de amido. Os pinhões utilizados nesta pesquisa foram provenientes de materiais genéticos e selecionados com base em testes preliminares por apresentarem temperatura de gelatinização inferior a 60ºC. Esta é considerada uma característica interessante e vantajosa, podendo economizar tempo e energia durante o processo de gelatinização do amido. O amido na sua forma natural apresenta limitações, portanto uma das alternativas é a hidrólise ácida que tem o intuito de alterar as suas propriedades físico-químicas. Este tratamento aliado a solução alcoólica apresenta a capacidade de recuperar grande parte do grânulo. O objetivo deste estudo foi identificar os efeitos da modificação ácida em meio aquoso e alcoólico de amidos de pinhão (A. angustifolia) com temperaturas de gelatinização abaixo de 60 ºC. As amostras foram avaliadas quanto ao pH e Colorimetria, por análise térmica (TG-DTA e DSC), pelo comportamento reológico (RVA), por análises estruturais (DRX e MEV) e por análises estatísticas (ANOVA e Tukey). A recuperação do grânulo de amido foi maior no meio aquoso e no meio alcoólico os valores ficaram próximos a 90% de recuperação. Os valores de pH comprovaram que o processo eliminou o ácido utilizado na modificação e a colorimetria identificou a coloração branca e levemente amarela para ambos os acessos, mostrando que os tratamentos não alteraram as características colorimétricas dos amidos de pinhão. Nas curvas TGDTA em ar sintético foram observadas três perdas de massa. As amostras nativas apresentaram diferença no DTA e as temperaturas finais demonstraram maior resistência térmica dos amidos. Nas curvas TG-DTA em nitrogênio foram encontradas duas perdas de massa. As amostras tratadas apresentaram semelhança no DTA e as temperaturas finais não foram alteradas devido à atmosfera inerte. Na análise de DSC, a Tc e a ∆Hgel não apresentaram diferenças significativas, apenas no To e Tp. Os tratamentos mais intensos mostraram leve resistência térmica e menor ∆Hgel. No RVA foi observado redução nos parâmetros de viscosidade conforme a intensidade do tratamento. O DRX identificou o padrão do tipo C para os amidos e a cristalinidade relativa aumentou conforme a intensidade da hidrólise ácida. Pelo MEV foram observadas alterações superficiais nos grânulos. Diante dos resultados encontrados, os amidos de pinhão demonstraram ser promissores para aplicações industriais visando specialties, ou seja, para produtos com escala reduzida. O intuito é estimular os pequenos produtores, proporcionar agregação de valor ao produto final e a manutenção da espécie A. angustifolia. / Araucaria angustifolia (Bert.) O. Kuntze is a conifer present in Brazilian forests and its seeds are high in starch. The pinhões used in this research were derived from genetic material and selected based on preliminary tests because they presented a gelatinization temperature below the 60 ºC. This is considered an interesting and advantageous feature, which can save time and energy during the starch gelatinization process. Starch in its natural form has limitations, so one of the alternatives is acid hydrolysis, which has the purpose of altering its physicochemical properties. This treatment combined with alcoholic solution has the ability to recover majority of the granule. The aim of this study was to identify the effects of acidic modification on aqueous and alcoholic solutions of pinhão starches (A. angustifolia) with gelatinization temperatures below of 60 ºC. The samples were evaluated for pH and Colorimetry by thermal analysis (TG-DTA e DSC), by rheological behavior (RVA), by structural analysis (XRD and SEM) and by statistical analysis (ANOVA and Tukey). The recovery of the starch granule was higher in the aqueous medium and in the alcoholic solution; the values were close to 90% recovery. The pH values showed that the process eliminated the acid used in the modification and the Colorimetry identified the white and slightly yellow coloration for both accessions, showing that the treatments did not alter the colorimetric characteristics of the pinhão starches. In the TG-DTA curves in synthetic air, three mass losses were observed. The native samples presented a difference in the DTA and the final temperatures showed a higher thermal resistance of the starches. In the TG-DTA curves in nitrogen, two mass losses were found. The treated samples showed similarity in DTA and the final temperatures were not changed due to the inert atmosphere. In the DSC analysis, Tc and ΔHgel did not show significant differences, only in To and Tp. The most intense treatments showed light thermal resistance and lower ΔHgel. In the RVA, a reduction in the viscosity parameters was observed according to the intensity of the treatment. XRD identified the type C pattern for starches and relative crystallinity increased as the acid hydrolysis rate increased. Superficial changes in the granules were observed by SEM. Considering the results found, the pinhão starches demonstrated to be promising for industrial applications aiming specialties, that is, for products with reduced scale. The intention is to stimulate small producers, provide benefits to the final product and the maintenance of the species A. angustifolia.

The work deals with the preparation and study of polyphosphate composites. Aluminum phosphates provide some unusual properties like high-heat resistance in terms of inorganic binders. The addition of chromium in the form of Cr2O3 or directly the bond with the aluminum-chromium-phosphate can improve the properties of this binder. Highly viscous Al2Cr(H2PO4)9 and Al3Cr(H2PO4)12 binders were prepared by dissolving Al(OH)3 and CrO3 in 85% phosphoric acid, and mixed with Al2O3 and Cr2O3 fillers. The composites were cured in the furnace at 150 °C for 24 h under pressure of 10 MPa. During the annealing at temperatures up to 1 500 °C changes in chemical structure of the cured composites were observed, leading to the understanding of the creation of crystalline phases and their eventual changes. The characterization of binders was mainly based on FT-IR, EDAX, TG-DTA and optical microscopy analyses.