Orientador: Rosiane Lopes da Cunha / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-03T10:00:46Z (GMT). No. of bitstreams: 1 Cavallieri_AngeloLuizFazani_M.pdf: 989418 bytes, checksum: babcf5e74dc6ff4aa7b552001a22f631 (MD5) Previous issue date: 2003 / Resumo: Proteínas e polissacarídeos correspondem a biopolímeros muito utilizados pela indústria de alimentos devido às suas características funcionais, porém apresentam uma incompatibilidade natural quando em soluções. Sistemas compostos por proteínas do soro e xantana foram avaliados neste trabalho em diferentes condições de pH, com as proteínas nativas e desnaturadas termicamente. Análises de eletroforese em gel de poliacrilamida foram realizadas para verificar o efeito do tratamento térmico nas proteínas do soro, mostrando que o aquecimento de soluções de proteínas do soro a 80oe por trinta minutos causou a formação de grandes agregados protéicos estabilizados principalmente por interações dissulfídicas. Estes agregados tiveram influência marcante no comportamento de fases destas proteínas com a xantana. Soluções nativas de isolado protéico de soro 5% (p/p) e xantana entre 0,01 % a 1 % se revelaram compatíveis, porém quando as proteínas foram termicamente desnaturadas, estes sistemas se mostraram termodinamicamente incompatíveis, separando em duas fases. Um diagrama de fases capaz de descrever a região de incompatibilidade termodinâmica desses sistemas foi determinado, porém limitações experimentais atribuídas principalmente à ineficiência da ultracentrifugação na separação das fases incompatíveis quando as soluções possuem elevada viscosidade impediu a determinação da binodal de equilíbrio. O principal mecanismo termodinâmico envolvido na incompatibilidade termodinâmica seria a baixa entropia quando as proteínas do soro estão agregadas, porém efeitos de volume excluído entre os agregados e as grandes moléculas de xantana também poderiam estar envolvidos nesta incompatibilidade, principalmente quando as soluções são diluídas. A técnica reológica conhecida como compressão biaxial imperfeita com lubrificação foi adequada na determinação de diferenças de consistência de géis ácidos de isolado protéico de soro 7% (p/p). As soluções (48h armazenamento/10°C) apresentaram estabilização de pH entre 3,36 e 5,63 e os índices de comportamento do fluido em regime extensional variaram entre 0,19 e 0,43, enquantoque..os. Indices .deconsistência . extensional. variaramentre.131.eA127 kPa.sn, indicando o caráter pseudoplástico destes géis. Os géis mais consistentes foram obtidos nos pHs 4,73 e 5,10. Interações dissulfídicas foram responsáveis pela estabilização dos agregados no tratamento térmico e podem estar envolvidas no processo de gelificação, enquanto que interações eletrostáticas seriam as principais envolvidas na agregação das proteínas durante a redução do pH / Abstract: Proteins and polysaccharides are two biopolymers widely used in food industry for their functional characteristics, but these biopolymers show natural thermodynamic incompatibility in solution. Native and heat denatured whey proteins and xanthan systems were studied in this work in different pH conditions. Polyacrylamide gel electrophoresis (PAGE) analysis was used to verify the effect of heat treatment on whey proteins showing that the experimental conditions (80OC for 30 minutes) caused protein aggregation in large aggregates stabilized mainly by disulfíde interactions. The large protein aggregates had great influenceon phase behavior between such proteins and xanthan. Native whey protein (5% w/w) and xanthan (0,01-1% w/w) solutions are soluble, but such solutions beco me not soluble and show thermodynamic incompatibility, when the proteins are heat denatured. A phase diagram was established and it was able to describe the concentration region of ingredients incompatibility. The binodal line was not drawn due to experimental limitations, probably associated to the inefficiency of the uJtracentrifugation to separate the incompatible phases of high viscosity. Low mixture entropy due to protein aggregation is the main thermodynamic event leading to phase separation of this systems, but excluded volume effects between protein aggregates and great xanthan molecules could be involved in this incompatibility, mainly for diluted solutions. Imperfect lubricated squeezing flow viscosimetry analysis was able to distinguish consistency differences in acidified whey protein isolate (7% w/w) gels. The pH of whey protein solutions (48h storage/10°C) was stabilized between 3,36 and 5,63 and the flow index values under extensional fJow were between 0,19 and 0,43, while the consistency index values under extensíonal flow were between 131 and 4127 kPa.sn, indicating the shear thinning behavior of such gels. The strongest gels were obtaíned in the pH range between 4,73 and 5,10. Disulphide interactions were responsible for protein aggregation caused by the heat treatment, while eJectrostatic interactions could be the mainly factor determining protein aggregation duríng pH reduction / Mestrado / Mestre em Engenharia de Alimentos

Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第16852号 / 工博第3573号 / 新制||工||1540(附属図書館) / 29527 / 京都大学大学院工学研究科材料工学専攻 / (主査)教授 田中 功, 教授 乾 晴行, 准教授 宇田 哲也 / 学位規則第4条第1項該当

The aim of that diploma thesis is low power transformer simulation via its substitutitional circuitry.As Instrument for matematical description of model and simulation of various operating situations with different amplitude and types of load was used Labview software. The software was simultaneously used for real transformer measurement and to compare these results with calculated values. The created program is also applied for measuring excercise for students. In The thesis is described measured transformer in terms of final elements method in FEMM software and there is showed the procedure of its design.

This diploma thesis is focused on the study of the structural phase transitions in intermetallic compounds LaPd2(Al,Ga)2 by low-temperature x-ray powder diffraction and macroscopic measurements on single crystals. The results obtained from powder diffraction at room temperature confirm that the compounds crystallize in tetragonal CaBe2Ge2 structure type (space group P4/nmm). At low temperature all the compounds undergo the same structural phase transition by lowering the symmetry to the orthorhombic space group Cmma. Although the structural transformation is of first order, the transition is not-manifested in step-like change of the phase at a certain temperature, but occurs in a broader temperature interval. In this interval the different phases coexist and transform gradually from high- to low- temperature phase. After application of hydrostatic pressure the structural transition is shifted to higher temperatures. Despite that the low temperature structures are of the same type, there is a difference between compounds containing Ga and Al in the discontinuity of the lattice parameters resulting in a distinct anomaly in electrical resistivity. In pressures >0.6 GPa this characteristic anomaly on single crystalline CePd2Al2 is changed, indicating a pressure- induced change of the low-temperature...

In this work we report on physical properties of Nd2RhIn8 and Nd2IrIn8 rare-earth intermetallic compounds from the RmTnX{2n+3m} compound family. The compounds crystallize in the P4/mmm space group. Both compounds are anti-ferromagnetic with Néel temperatures TN of 10.8 K, 12.5 K respectively and their magnetization curves show characterisic step-like transitions at low temperatures. The measured M(T) and/or M(H) magnetization curves were used to determine magnetic phase diagrams for field along the c-axis. The specific heat of Nd2IrIn8 was analyzed at temperatures T<TN with respect to the dimensionality of the magnetic excitations. In the T>TN region the Schottky specific heat and susceptibility were compared to calculations based on the crystal field scheme in Nd2IrIn8 obtained by ab-initio methods. Powered by TCPDF (www.tcpdf.org)

This thesis focuses on the study of magnetic properties of three 5f electron itinerant ferromagnets UCo0.990Ru0.010Al, UCoGa and URhGa and investigation of their phase diagrams. The single crystals of high-quality were prepared by Czochralski method for all three compounds. The physical properties at ambient pressure were studied by macroscopic methods (magnetization, electrical transport and heat capacity measurements) and also by magnetic force microscopy (MFM). The measurements were done under various external conditions (high pressure, low temperatures, high magnetic field). Through all these measurements and external conditions we investigated the interesting physical properties and the ferromagnetic phase diagrams. Effect of different conditions during the preparation and the thermal treatment on UCoGa was studied on two different single crystals. We show that annealing leads to improved quality of samples and the gallium evaporation from the melt during the growth leads to lower quality in parts of the ingot closer to melt. MFM images of UCoGa below the ordering temperature show domain branching and narrow magnetic domains wall made only of neighboring atoms with opposing moments. We have grown first ever single crystal of URhGa with ferromagnetic ordering temperature TC = 41 K. Anomalous maximum in...

Among the many non-equilibrium processes encountered in nature we deal with two different but related aspects. One is the non-equilibrium relaxation process that is at the origin of \'aging phenomena••, and the other one is a non-equilibrium phase transition, called ••dynamic phase transition••. One of the main purposes of our research is to explore more realistic situations than studied previously. Indeed, in the study of aging phenomena certain kinds of disorder effects are considered, and we introduce the ••surface•• as a spatial boundary to the system undergoing the dynamic phase transition. In order to observe these processes as clearly as possible, we study in both cases simple spin systems. Using Monte Carlo simulations we first investigate aging in three-dimensional Ising spin glasses as well as in two-dimensional Ising models with disorder quenched to low temperatures. The time-dependent dynamical correlation length L(t) is determined numerically and the scaling behavior of various two-time quantities as a function of L(t)/L(s) is discussed where t and s are two different times. For disordered Ising models deviations of L(t) from algebraic growth law show up. The generalized scaling forms as a function of L(t)/L(s) reveal a generic simple aging scenario for Ising spin glasses as well as for disordered Ising ferromagnets. We also study the local critical phenomena at a dynamic phase transition by means of numerical simulations of kinetic Ising models with surfaces subjected to a periodic oscillating field. We examine layer-dependent quantities, such as the period-averaged magnetization per layer Q(z) and the layer susceptibility ¥ö(z), and determine local critical exponents through finite size scaling. Both for two and three dimensions, we find that the values of the surface exponents differ from those of the equilibrium critical surface. It is revealed that the surface phase diagram of the non-equilibrium system is not identical to that of the equilibrium system in three dimensions. / Ph. D.

権利表示を行うこと, 出典表示を行うこと, 出版社版へのリンクを表示すること / 京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第19488号 / 理博第4148号 / 新制||理||1596(附属図書館) / 32524 / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)教授 大西 明, 准教授 菅沼 秀夫, 教授 田中 貴浩 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第21104号 / 工博第4468号 / 新制||工||1694(附属図書館) / 京都大学大学院工学研究科材料工学専攻 / (主査)教授 杉村 博之, 教授 田中 功, 准教授 野瀬 嘉太郎 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第20915号 / 理博第4367号 / 新制||理||1627(附属図書館) / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)准教授 菅沼 秀夫, 教授 田中 貴浩, 教授 川合 光 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM