Orientador: Hidekasu Matsumoto / Banca: Wyser Jose Yamakami / Banca: João Paulo Pereira Marcicano / Resumo: Este trabalho discute a viabilidade da substituição do estabilizante térmico a base de chumbo pelo de cálcio-zinco na produção de tubos de pvc rígido, através de análise em resultados experimentais, obtidos diretamente na indústria. De forma objetiva, foi descrito o processo de fabricação, bem como as matérias primas utilizadas e os ensaios , utilizados durante a fabricação. Foram realizados vários ensaios em doze lotes, de seis tubos de diferentes bitolas, produzidos nas plantas de Penápolis(S.P) e Simões Filho(BA), do grupo Asperbrás, de acordo com normas ditadas pela ABNT. Para cada produto (tubo), foram produzidos dois lotes distintos, um com estabilizante a base de chumbo e o outro com estabilizante a base de cálcio-zinco. A princípio, manteve-se iguais, todas as outras características de processamento, permitindo assim uma melhor análise dos resultados obtidos. Os dados obtidos, depois de analisados, permite-nos concluir,que sob o ponto de vista técnico, essa mudança é inteiramente satisfatória, pois conseguimos uma melhora significativa nas propriedades físicas do produto final, aumento de produtividade em torno de 6%, diminuição do índice de lotes rejeitados e por fim a eliminação definitiva do chumbo nas formulações das blendas, atendendo os apelos dos ecologistas e ambientalistas. Já sob o ponto de vista econômico, ficou claro, que, considerando apenas os custos diretos dos dois produtos, os estabilizantes a base de cálcio-zinco, são mais caros cerca de 25%, quando comparados aos de chumbo. Porém, quando utilizados em formulações de compostos, em quantidades adequadas ao processo, juntamente com os outros componentes, essa diferença pode praticamente se anular, viabilizando economicamente a tal mudança. / Abstract: In this work it was discussed the viability of substituting the thermo stabilizer based on lead by the calcium-zinc in the production of rigid PVC pipes, through analysis of experimental results obtained directly from the industry. Briefly, it was described the process of manufacture, as well as, the materials and assays used during the manufacturer. It were performed several assays in twelve portions of six pipes with different diameters, produced in the factories of Penápolis, São Paulo and Simões Filho, Bahia, Brazil, belonging to the Asperbras group, according to the rules from ABNT (Brazilian Association of Technical Rules). For each product (pipe) it were produced two distinct groups, one with the stabilizing based on lead and the other with the calcium-zinc stabilizing. At first, it was maintained unchanged all the other characteristics of processing, allowing a better analysis of the obtained results. The analyzed data allow the conclusion that according to the technical point of view, this change is totally satisfactory, since we got a good improvement in the physical properties of the final product, as well as, an increase in the yield around 6%, in addition to a decrease in the non-acceptable portions. At the end, it was obtained a definitive elimination of lead in the blends formulations, in accordance to the ecologists and environmentalist's appeals. Under the economical point of view it has become clear, that if consider just the direct costs of the two products, the stabilizers based on calcium-zinc are around 25% more expensive when compared to the lead based products. However, when utilize the calcium-zinc stabilizers in appropriated formulations of compounds and in quantities appropriated to the process, with the other components, this difference is not significant, turning viable this new formulation. / Mestre

Orientador: Ana Rita Morales / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-25T09:26:38Z (GMT). No. of bitstreams: 1 Silva_MayaraPollyaneCalderaroda_M.pdf: 15566719 bytes, checksum: 69f8e0b6d9d762e986aa7a4cd0a23609 (MD5) Previous issue date: 2014 / Resumo: Neste estudo, foram preparadas amostras de ABS variando-se as concentrações de um aditivo estabilizador a luz ultravioleta (UV) do tipo HALS (Tinuvin 770), um absorvedor (Cyasorb 5411) e negro de fumo. Um planejamento experimental 2³ foi realizado para estudar a influência destes aditivos e suas diferentes concentrações nas propriedades de ponto de amolecimento Vicat, resistência ao impacto IZOD e resistência à tração, antes de se realizar ensaios de envelhecimento. O aditivo HALS utilizado apresentou influências negativas sobre algumas propriedades analisadas, sendo a temperatura de amolecimento Vicat a propriedade que mais apresentou perda significativa com o aumento da concentração dos aditivos nas amostras. Para melhor avaliar este efeito, ensaios de caracterização foram realizados. Os resultados de Calorimetria Exploratória Diferencial (DSC) e Análise Térmica Dinâmico-Mecânica (DMTA), apresentaram diminuição na temperatura de transição vítrea (Tg) com o aumento dos aditivos estabilizadores à luz ultravioleta nas formulações, estando estes resultados em concordância com os ensaios de ponto de amolecimento Vicat realizados. O aditivo Tinuvin 770 tem em sua composição o componente sebacato, (CH2)8, que pode ser utilizado como plastificante para baixar a Tg dos polímeros. A perda das propriedades acima citadas pode ser devido à presença deste componente no aditivo HALS, Tinuvin 770. Neste trabalho também foi avaliada a eficiência das diferentes concentrações dos aditivos nas amostras após envelhecimento. As amostras foram submetidas ao envelhecimento acelerado com lâmpadas UVA por 1008 h para análise do desempenho dos aditivos utilizados. Os resultados dos testes mecânicos mostraram que o negro de fumo é bastante efetivo como absorvedor e apresentou boa interação com aditivo HALS, protegendo o polímero da degradação / Abstract: In this study, samples of ABS varying the concentration of a stabilizer additive ultraviolet (UV) type HALS (Tinuvin 770), an absorber (Cyasorb 5411) and carbon black were prepared. An experimental design 2 ³ was conducted to study the influence of these additives and their different concentrations in the properties of Vicat softening point, IZOD impact resistance and tensile strength before performing aging tests. The HALS additive had negative influence on some properties, the Vicat softening temperature showed the most significant loss when the concentration of additives was increased in the samples. To further evaluate this effect, characterization tests were performed. The results of Differential Scanning Calorimetry (DSC) and Dynamic Mechanical (DMTA) Thermal analysis showed a decrease in the glass transition temperature (Tg), with the increase of the UV light stabilizers in formulations, showing that these results are in agreement with the tests performed for Vicat softening point. Tinuvin 770 additive has in its composition the component sebacate, (CH2)8, which can be used as a plasticizer to lower the Tg of polymers. The loss of the aforementioned properties may be due to the presence of this component in the additive HALS Tinuvin 770. In this study it was also evaluated the effectiveness of different concentrations of additives in the samples after aging. The samples were subjected to accelerated aging with UVA lamps by 1008 h to analyze the performance of the additives used. The results of mechanical tests showed that carbon black is very effective as absorber and had good interaction with HALS additive, protecting the polymer from degradation / Mestrado / Ciencia e Tecnologia de Materiais / Mestra em Engenharia Química

This thesis studies the relationship of income tax progressivity and output volatility. Using our dataset of 31 OECD countries and Bayesian model averaging (BMA) approach to address the model uncertainty issue, we find positive evidence that higher income tax progressivity leads to lower output volatility. This effect is robust to different prior specifications in BMA and to different tax progressivity measures, including our newly constructed measure which is based on the slope of the average tax curve. We also find a strong effect of tax progressivity on the consumption volatility and the volatility of hours worked which we see as the main channels for the reducing effect of tax progressivity on output volatility.

京都大学 / 新制・課程博士 / 博士(医学) / 甲第23408号 / 医博第4753号 / 新制||医||1052(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 中山 健夫, 教授 古川 壽亮, 教授 村井 俊哉 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Presented diploma thesis was focused on study of influence of stabilizers and other components on final quality of mixtures for ice-cream production. This thesis was worked out in cooperation with Frujo Co., Ltd., Tvrdonice to find out the most suitable stabilizer with positive influence on the quality of final product. In experimental part six mixtures of stabilizers, three mixtures for ice-cream production and particular ingredients for production of mixtures for ice-cream production were analysed. Saccharides and lipids were analysed only in mixtures of stabilizers. Content of saccharides was analyzed using spectrophotometry and HPLC/RI. Lipid components were analysed by TLC. Viscosity was measured by rotatory viscosimeter and the differences of flow curves of each mixture with different stabilizers were monitored. Based on viscosity measurements some ice-creams with different stabilizers were chosen for sensory analysis. Mixture of stabilizers “Stobicol” was analysed for active compounds and antioxidant stability. Microbiological stability was tested in all of the stabilizers and also in particular ingredients including final mixture for ice-cream production. In three ice-cream mixtures of different flavour protein composition was measured by microfluidic electrophoresis. The highest content of total and reducing saccharides was determined in hydrolyzed samples. The highest values of total saccharides were found in mixture of stabilizers “Meyprogen”, the highest values of reducing saccharides were detected in stabilizer “Swissgum”. Content of triglycerides was found out almost in all of the measured mixtures of stabilizers using TLC method even though according to formulas provided by producers there should not be any. Diglycerides were detected in “Meyprogen” too even though this mixture of stabilizers should contain only saccharides. Based on results of rheology measurements and in connection with sensory analysis “Meyprogen” stabilizer could be recommended as the best material for the industrial production.

Orientador: Geraldo de Freitas Maciel / Resumo: Esta pesquisa tem como principal objetivo verificar experimentalmente a presença de instabilidades na superfície livre de escoamentos lamosos, em canal com 10 metros de comprimento. Estes escoamentos, quando em condições favoráveis de vazão e inclinação, podem constituir um domínio favorável à geração de roll waves, instabilidades que evoluem adquirindo característica periódica e que se propagam com amplitudes, comprimentos e velocidade de propagação bem definidas. O fluido teste utilizado nos ensaios foi uma mistura de água+argila caulinítica (representativo do material lamoso em desastres naturais), confeccionada com uma concentração em volume de 25% e caracterizada reologicamente pelo modelo de Herschel Bulkley. Foram testados dois surfactantes (estabilizantes químicos), Tween 80 e goma xantana, para estabilizar os parâmetros reológicos da mistura, tendo a goma xantana garantido maior tempo de estabilização. A aferição da superfície livre foi realizada por meio de sistema não-intrusivo (transdutor ultrassônico), que se mostrou eficiente para aferição de ondas íngremes e de pequenas amplitudes. Os resultados de ensaios experimentais exploratórios foram confrontados com o modelo matemático 1D desenvolvido pelo grupo de pesquisa. / Abstract: This project has as main objective to experimentally verify the presence of instabilities in the free surface of muddy flows in a ten meter long channel. These flows, when situated under favorable flow and slope conditions may constitute a favorable domain for the generation of roll waves, instabilities that evolve acquiring periodic characteristics and propagate itself with well-defined amplitudes, lengths and velocity. The test fluid used in the experiment was a mixture between water + kaolinitic clay (representative of the muddy material in natural disasters), made with a 25% volume concentration and rheologically characterized by the Herschel Bulkley model. Two surfactants (chemical stabilizers), Tween 80 and xanthan gum, were tested to stabilize the rheological parameters of the mixture, with the xanthan gum ensuring longer stabilization time. The free surface measurement was performed using a non-intrusive system (ultrasonic transducer), which proved to be efficient for the measurement of steep waves with small amplitudes. The results of exploratory experimental tests were compared with the 1D mathematical model developed by the research group. / Mestre

Synthetic antioxidants and UV-stabilizers are additives used in plastic products in order to protect the polymers from degradation caused by oxygen and ultraviolet light. Few studies have been performed about the presence of these compound groups in the environment and there is very sparse data on their distribution in the environment in Sweden. The objective of this study was to investigate the presence of ten common antioxidants and UV-stabilizers and two antioxidant metabolites [2-tert-butyl-4-methoxyphenol (1); 2,6-di-tert-butyl-4-methylphenol (2); 3,5-ditert-butyl-4-hydroxybenzaldehyde (3); 2,6-ditert-butylcyclohexa-2,5-diene-1,4-dione (4); 1,3,5-tris[(4-tert-butyl-3-hydroxy-2,6-dimethylphenyl)-methyl]-1,3,5-triazinane-2,4,6-trione (5); tris(2,4-ditert-butylphenyl) phosphite (6); [3-[3-(3,5-ditert-butyl-4-hydroxyphenyl)propanoyloxy]-2,2-bis[3-(3,5-ditert-butyl-4-hydroxyphenyl)propanoyloxymethyl]-propyl]3-(3,5-ditert-butyl-4-hydroxyphenyl)propanoate (7); octadecyl 3-(3,5-ditert-butyl-4-hydroxyphenyl)propanoate (8); 2-tert-butyl-4-(5-tert-butyl-4-hydroxy-2-methylphenyl)sulfanyl-5-methylphenol (9); bis(2,2,6,6-tetramethylpiperidin-4-yl) decanedioate;2-hydroperoxy-2-methylpropane; octane (10); bis(3,3,5,5-tetramethylpiperidin-4-yl) decanedioate (11) and 4-methylhexyl-3-[3-(benzotriazol-2-yl)-5-tert-butyl-4-hydroxyphenyl]propanoate (12)] in water and snow in Stockholm and its surroundings. A method was developed for the determination in water by solid phase extraction (SPE) in order to extract and concentrate the compounds, followed by analysis by liquid chromatography – electrospray – tandem mass spectrometry (LC-ESI-MS/MS). Three compounds (2, 4, 11) were excluded from the method development since (2) and (11)could not generate a signal on the mass spectrometer whereas (4) could not produce a linear response. Due to the wide range of physicochemical properties of the analytes low recoveries were observed. Sampled water and snow from the Stockholm area was analysed and (3) and (9) were found in two of the water samples whereas (10) was observed in all water samples, below the quantification limit. Due to the lack of time, no methods were developed for the determination of the selected plastic additives in other environmental compartments.

Light chain (AL) amyloidosis is a disease that occurs due to the presence of a small plasma-cell clone, which produces amyloidogenic light chains. These chains can misfold and aggregate, leading to the deposition of amyloid fibrils in tissues. If left untreated or if treatment is ineffective, this can result in irreversible organ dysfunction and eventual death. Current therapeutic treatments generally target and remove the clonal plasma cell population responsible for secreting full-length light chains which is not always effective or safe, however, a different approach to halt pathological LC misfolding would be to inhibit the amyloidogenesis cascade at its starting point. Small molecules have been identified that have the ability to bind to highly conserved residues in the interface between heavy and light chains which can be used to potentially impede the process of amyloid fibril deposition before the native FL LC can misfold or undergo proteolysis to form amyloid fibrils. To test whether small-molecule kinetic stabilizers are effective in stabilizing light chains, we measured the ability of the small molecule to bind to LCs, and the ability of light chains to aggregate and unfold in the absence and presence of small-molecule. Our findings suggest that the binding of stabilizers to the interface between variable domains of the LC dimer can increase equilibrium stability and decrease the rate of aggregation, thereby delaying the onset of amyloid formation.

No description available.

O interesse sobre o mercado de produtos vegetarianos e veganos tem crescido muito na última década, sendo que novos produtos alimentícios fortificados são continuamente introduzidos nesse segmento. Como grande parte do público vegano possui deficiências na ingestão de vitaminas D3 e B12, torna-se interessante o desenvolvimento de produtos com adição dessas vitaminas como fortificantes de alimentos. O objetivo principal desta Dissertação foi produzir e caracterizar um gel de pectina carregado de emulsão, incorporando vitaminas D3 e B12. As emulsões foram produzidas com óleo de linhaça como fase dispersa e inulina associada à goma arábica como estabilizantes. A emulsão foi produzida por método de alto cisalhamento, em tampão citrato (pH 4,0) (devido à melhor estabilidade da vitamina B12 em tal pH) e em baixa temperatura (30 °C) para minimizar a degradação de vitamina D3. As emulsões foram avaliadas utilizando difração a laser, se apresentando estáveis ao longo de 30 dias de estocagem e com diâmetro médio de 2,75 ± 0,25 µm. A vitamina D3 não sofreu degradação no período avaliado. Os géis foram produzidos com pectina de baixo grau de metoxilação amidada (pectina LMa) utilizando-se uma concentração de 4 % (g/g), a 60 °C, com 30 % (g/g) de sacarose, 0,1 % (g/g) de CaCl2.2H2O, em tampão citrato (pH 4,0). Substituiu-se 60 % (g/g) da água da matriz do gel pela emulsão e foram obtidos géis carregados firmes. Através de ensaios reológicos e de compressão uniaxial foi possível verificar que os géis carregados possuem uma rede estrutural mais forte do que o gel não-carregado, mostrando que as partículas são ativas. O gel carregado com 40 % de substituição da fase aquosa foi o gel mais forte, a ele adicionou-se as vitaminas. A vitamina B12 se mostrou estável, assim como os parâmetros colorimétricos dos géis carregados e dos géis nãocarregados após 30 dias. Assim, foi possível produzir géis de pectina carregados de emulsão, incorporando-se as vitaminas D3 e B12, que se mostraram estáveis ao longo do tempo de armazenamento. / Interest in the vegetarian and vegan product market has grown sharply over the past decade, with new fortified food products being continuously introduced into this market segment. As a large part of the vegan public has deficiencies in the intake of vitamins D3 and B12, it becomes interesting to develop products with addition of these vitamins as food fortifiers. The main objective of this research was to produce and characterize an emulsion-laden pectin gel incorporating vitamins D3 and B12. The emulsions were produced with flaxseed oil as dispersed phase and inulin associated with gum arabic as stabilizers. The emulsion was produced by the high shear method, in citrate buffer (pH 4.0) (due to the improved stability of vitamin B12 at such pH) and at low temperature (30 °C) to minimize vitamin D3 degradation. The emulsions were evaluated using laser diffraction, being stable over 30 days of storage and with an average diameter of 2.75 ± 0.25 µm. Vitamin D3 was not degraded in the evaluated period. The gels were produced with low amidated methoxylation pectin (LMa pectin) using a concentration of 4% (w/w) at 60°C with 30% (w/w) sucrose, 0.1% (w/w) of CaCl2.2H2O in citrate buffer (pH 4.0). The emulsion replaced a percentage of 60% (w/w) of the gel matrix aqueous phase and strong emulsion-filled gels were obtained. Through rheological and uniaxial compression tests, it was possible to verify that the emulsion-filled gels have a stronger structural lattice than the uncharged gel, showing that the particles are active. The gel filled with 40% aqueous phase replacement was the strongest gel therein, and the vitamins were added to it. Vitamin B12 was shown to be stable, as were the colorimetric parameters of filled and unfilled gels after 30 days. Therefore, it was possible to produce emulsion-filled pectin gels and to incorporate vitamins D3 and B12, which were shown to be stable over the storage time.