Дисертації з теми "Concentrated mass"

Non-stationary vibrations of complex mechanical systems that can be considered in the form of beams and plates with various mechanical features are investigated. Modeling of features (concentrated masses, additional supports and stiffeners) is made by replacing their influence with non-stationary concentrated forces (reactions), which are determined from the solution of Volterra integral equations using Tikhonov's regularizing algorithm.

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CAPES
Nesta pesquisa objetivou-se avaliar os efeitos da suplementação concentrada sobre o desempenho de novilhas de corte em pastejo no período das águas. O experimento foi realizado em propriedade rural localizada no município de Rondonópolis-MT nas coordenadas geográficas Latitude 16°28’ S e Longitude 54° 38’W. O Período experimental foi de dezembro de 2013 a maio de 2014, com duração 136 dias. Os tratamentos, constituídos pelo fornecimento de suplementação concentrada ao nível de 0; 0,5 e 1,0% do peso corporal (PC) dos animais, foram distribuídos em um delineamento em blocos casualisados com duas repetições (área). Cada uma das seis áreas experimentais foi composta por oito piquetes de 0,1 hectares e por uma área de 200 m2 de livre acesso aos animais, na qual foram alocados os comedouros e bebedouros. O método do pastejo adotado foi o de lotação rotacionada com carga animal variável. Foram utilizadas 36 novilhas (animais testes) com peso corporal (PC) médio 249,3 Kg e aproximadamente 16 meses de idade. Estes animais foram pesados no início e final do experimento após jejum de sólidos e líquidos de 14h. Outras dezesseis novilhas (animais reguladores) de iguais composições genéticas e contemporâneas aos animais testes foram adicionadas e removidas das áreas experimentais sempre que houve a necessidade de se ajustar a taxa de lotação à capacidade de suporte dos pastos. O ganho de peso diário dos animais testes foi utilizado para estimar o desempenho individual das novilhas. O ganho de peso por área (kg/ha) foi calculado com base nos ganhos de pesos individuais médios dos animais testes e no número de animais totais (testes e reguladores) de cada área experimental, animais dia/ha. Os componentes da massa de forragem (lâmina foliar, colmo e material senescente), e composição química da forragem foram estimados por ciclo de pastejo, a partir da amostragem de três piquetes de cada área experimental. Em cada um destes piquetes foram coletadas, no pré-pastejo e no pós-pastejo, três amostras de forragens para determinação dos componentes da massa de forragem. Para a composição química foi coletada, no pré-pastejo, uma amostra de forragem por piquete. A análise financeira por tratamento foi realizada considerando como receita a quantidade de arrobas produzidas e o preço de venda da arroba e como desembolsos os gastos com suplemento mineral, concentrado, adubos, vermífugo e mão de obra. As variáveis relacionadas à forragem foram analisadas estatisticamente considerando a estrutura da matriz de covariâncias composta simétrica com a utilização do procedimento MIXED do programa SAS. As variáveis relacionadas ao desempenho dos animais foram analisadas utilizando-se o procedimento GLM do mesmo programa. As médias foram comparadas pelo teste de tukey a 5% de probabilidade. Foram observados ganhos de pesos de individuais de 0,562; 0,746 e 0,895 kg/dia para os animais que receberam 0; 0,50 e 1,0% do PC de suplemento concentrado, respectivamente. Valores médios de 653, 958 e 1438 kg/ha de ganho de peso e 5,44; 6,02 e 7,70 UA/ha de taxa de lotação foram obtidos com 0; 0,50 e 1,0% do PC de suplementação concentrada, respectivamente. Não houve efeito de tratamento sobre a massa de lâmina foliar, massa de colmo, massa de material morto e massa de forragem total no pré-pastejo e no pós-pastejo. Todavia, essas variáveis foram influenciadas pelo ciclo de pastejo. As alturas do pasto no pré-pastejo foram influenciadas pela suplementação concentrada, com valores de 37,2; 37,6 e 42,9 cm para os níveis de suplementação concentrada de 0; 0,50 e 1,0% do PC, respectivamente. A composição química da forragem no pré-pastejo não foi alterada pelas estratégias de suplementação concentrada, com valores médios de médios de 7,7; 8,9 e 8,3% de PB e 64,1; 63,8 e 64,4% de FDN para os níveis de 0; 0,50 e 1,0% do PC de suplementação concentrada, respectivamente. A margem bruta obtida foi de 1081,5; 1131,6 e 1242,2 R$/ha para os níveis de 0; 0,50 e 1,0% do PC, respectivamente. A suplementação concentrada de novilhas de corte em pastejo no período das águas intensifica os ganhos de pesos individuais e por área e contribui com a rentabilidade do sistema de produção.
This study aimed to evaluate the effects of concentrate supplementation on performance of grazing beef heifers in the rainy season. The experiment was conducted in a rural property in the city of Rondonópolis-MT, located in the geographical coordinates Latitude 16°28’S, Longitude 54°38’W. The experimental period was from December of 2013 to May of 2014, lasting 136 days. The treatments were consisted of concentrated supplementation at the level of 0; 0.5 and 1.0% of body weight (BW) of the animals, being distributed in a randomized blocks with two repetitions (area). Each of the six experimental areas was composed of eight paddocks of 0.1 hectares and an area of 200 m2 with free access to the animals, in which the feeders and water drinkers were allocated. The grazing method adopted was the rotational stocking with variable stocking rate. It was used 36 heifers (testing animals) with BW with average of 249.3 kg and approximately 16 months old. These animals were weighed at the beginning and end of the experiment after 14 hours of solid and liquid fasting. Other 16 heifers (regulators animals) of the same genetic and contemporary compositions to the testing animals were added and removed from the experimental areas whenever there was a need to adjust the stocking rate on the pasture carrying capacity. The animal testing daily weight gain was used to estimate the performance of individual heifers. The weight gain per area (kg/ha) was calculated based on the average of individual weight gain of the testing animals and the total number of animals (testing and regulators) of each experimental area, animals day/ha. The components of the herbage mass (leaf blade, stem and senescent material) accumulation of forage and chemical composition of the forage were estimated by grazing cycle, from the sample of three paddocks of each experimental area. In each of these paddocks were collected three samples of forage, in the pre-grazing and post-grazing, to determine the mass of the components of forage. For the chemical composition, was collected a sample of forage per paddock in the pre-grazing. The financial analysis by treatment was carried out considering as revenue the amount of kilos produced and the selling price of kilos and as disbursements the expenditures on mineral supplement, concentrate, fertilizers, vermicides and labor. The variables related to the forage were analyzed statistically considering the structure of the compound symmetric covariance matrix using the SAS PROC MIXED. The variables related to the performance of the animals were analyzed using the GLM procedure of the same program. The averages were compared by Tukey test at 5% probability. It was observed individual gain of 0.562; 0.746 and 0.895 kg/day in animals were fed with 0; 0.50 and 1.0% of BW of concentrated supplement, respectively. Mean values of 653; 958 and 1438 kg/ha of weight gain and 5.44; 6.02 and 7.70 AU/ha of stocking rates were obtained with 0; 0.50 and 1.0% of concentrated supplementation of PC, respectively. There was no treatment effect on the leaf blade mass, stem mass, dead material mass and forage mass of the pre-grazing and post-grazing. However, these variables were influenced by grazing cycle. The grass heights in the pre-grazing were influenced by concentrated supplementation, with values of 37.2; 37.6 and 42.9 cm for the levels of supplementation of 0; 0.50 and 1.0% of BW, respectively. The forage chemical composition in the pre-grazing was not affected by concentrate supplementation strategies, with average mean values of 7.7; 8.9 and 8.3% crude protein and 64.1; 63.8 and 64.4% of NDF to levels of 0; 0.50 and 1% of concentrated supplementation of BW, respectively. The gross margin obtained was 1081.5; 1131.6 and 1242.2 R$/ha for levels of 0; 0.50 and 1.0% of BW, respectively. The concentrated supplementation of grazing beef heifers in the rainy season intensifies the individual weight gain by area and contributes to the production system profitability.

L’optimisation de l’incorporation et de la libération de principes actifs dans les produits formulés constitue un des enjeux majeurs des industries pharmaceutiques et cosmétiques. L'objectif principal de notre étude est de proposer un modèle prédictif de la diffusion de petites sondes au sein des émulsions concentrées. Pour cela, il a fallu considérer à la fois la formulation d’émulsions concentrées stables et leur caractérisation rhéologique et structurelle ainsi que la prédiction des paramètres de transfert des sondes au sein des émulsions concentrées. On entend par paramètres de transfert, tous les paramètres permettant de caractériser les différents mécanismes de transfert de sondes dans les émulsions concentrées pris en compte dans notre système, à savoir le coefficient de diffusion dans les phases continue et dispersée, le coefficient de transfert à l’interface eau/huile, le coefficient de partage à l’équilibre de la sonde entre les deux phases de l’émulsion. Une nouvelle approche de caractérisation de la structure des émulsions concentrée a permis l’obtention des paramètres importants de structure (taille des gouttes et épaisseur du film de la phase continue). L’étude détaillée des mécanismes et processus diffusionnels est réalisée avec la prise en compte des résultats liés à la caractérisation structurelle du système d’étude. Ainsi, un modèle de diffusion fondé sur une approche phénoménologique est proposé pour prédire l'évolution des profils de concentration de la sonde dans les émulsions concentrées. Les cinétiques expérimentales de libération des sondes sont comparables à celles simulées par le modèle sans paramètres ajustables. Cette comparaison montre une bonne adéquation entre le modèle de diffusion et l’expérience
In the field of controlled release technology for new drugs, models that can predict its delivery during application are important for device design. The main objective of this work is to develop a predictive model able to describe the drug delivery from highly concentrated water-in-oil emulsions. These systems consist of deformed droplets dispersed in a continuous film. Their structure’s characteristics make them favourable for their use as releasing devices. A combination of different transfer mechanisms has been implemented in a mathematical model in order to simulate release experiments under different operating conditions (volume fraction, oil/surfactant ratio). A sensitivity analysis has been performed to point out the most relevant parameters affecting the drug’s release: drug partition and diffusion coefficients. Partition coefficient of the drug for different surfactant concentrations has been obtained through a predictive thermodynamic model UNIFAC, and the diffusion coefficient using Chang and Wilke equations in addition to the Stefan- Maxwell development. An original and simple technique has been used to determine indirectly the mean droplet size of the concentrated emulsions, through measurements of continuous phase’s thickness by analysis of incoherent polarized steady light transport through emulsion samples. In a general view, the diffusion model proposed for small drug diffusion in concentrated emulsions, which was first proposed for diluted emulsions, predicts successfully the evolution of mandelic acid concentrations during release experiments undertaken in perfect sink conditions

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A secagem é um processo termodinâmico, em que há transferência simultânea de calor e a remoção da umidade de um material poroso. Os produtos argilosos quando expostos a uma secagem sem controle pode sofrer fissuras e deformações, reduzindo sua qualidade póssecagem. Este trabalho tem como objetivo estudar teórico e experimentalmente a transferência de calor e massa em sólidos com forma complexa com, com ênfase a secagem de materiais cerâmicos argilosos. Neste trabalho desenvolveu-se um modelo matemático para descrever as trocas de calor e massa durante o processo de secagem, utilizando o método da capacitância global em corpos vazados. A solução analítica das equações governantes foi feita usando o método de separação de variáveis. Foram realizados experimentos de caracterização química e terrmo-hídrica da argila, e secagem de materiais cerâmicos argilosos vazados e com formas não-convencionais, em diferentes temperaturas (60, 70, 80, 90 e 100ºC). Resultados da composição química e granulometria da argila, e cinéticos de perda de massa e aquecimento das peças cerâmicas são apresentados e analisados. Verificou-se que o processo de perda de umidade ocorre a uma velocidade mais baixa do que o aquecimento do material cerâmico, que a temperatura e forma do corpo afetam fortemente os fenômenos de transporte de calor e massa, que a secagem a baixa temperatura favorece a redução de problemas no material pós secagem e melhoramento na qualidade final, e que os números de Biot de transferência de calor e de massa influenciam diretamente no tempo que o produto atinge sua condição de equilíbrio. A comparação entre o teor de umidade e temperatura preditos pelo modelo matemático proposto e os dados experimentais permitiu a estimativa dos coeficientes de transferência de massa e calor na superfície do material, com boa precisão.
Drying is a thermodynamic process, in which there is simultaneous heat transfer and moisture removal of a porous material. Clay products exposed to drying without control may suffer cracks and deformations, reducing its quality post-drying. This work aims to study theoretical and experimental the drying of solids with complex shape. It was developed a mathematical model to describe heat and mass transfer during the drying process, using the global capacitance method of hollow bodies. The analytical solution of the governing equations was made using the variable separation method. It were realized experiments of chemical and thermo-hydric characterization of clay, and drying of hollow and non-conventional clay ceramic materials at different emperatures (60, 70, 80, 90 and 100ºC). Results of the chemical composition and granulometry, and mass loss and heating of ceramic parts are presented and analyzed. It was verified that the moisture loss process occurs at a lower velocity than the heating of the ceramic material, the temperature and body shape strongly affect heat and mass transport phenomena, drying at low temperature favors the reduction of the problems in the material post-drying and improvement in the final quality, and that Biot numbers of heat and mass transfer directly affect the time to the product to reach its equilibrium condition. Comparison between predicted and experimental moisture content and temperature permitted estimative of the convective heat and mass transfer coefficients at the surface of the material, with good precision.

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O processo de secagem consiste na remoção de umidade de um material através do aquecimento, envolvendo mecanismo simultâneo de transferência de calor e massa entre o material e o ar de secagem, sendo uma importante etapa na conformação de um material cerâmico e argiloso. Neste sentido, este trabalho objetiva a simulação da secagem de sólidos vazados e com forma arbitraria. Para descrever o processo de secagem de materiais porosos utilizou-se o método da capacitância global. A aplicação tem sido feita para a secagem de materiais cerâmicos afim de obter resultados cinéticos de perda de massa e calor dos mesmos. Foram simulados diferentes casos variando-se a forma do corpo, de onde obteve-se as cinéticas de secagem (perda da umidade) e aquecimento do sólido (aumento de temperatura). Observou-se que o processo de perda de umidade ocorre numa menor velocidade que o aquecimento do material cerâmico, pois a sua difusividade térmica é muito superior a difusividade de massa, e que o formato do sólido, particularmente a sua relação área/volume afeta fortemente os fenômenos de transporte de calor e massa.
The drying process consists of the removal of moisture from a material through heating, involving simultaneous heat and mass transfer between the material and the drying air, being an important step in the formation of a clay and ceramic material. In this sense, this work aims at simulating the drying of cast and cast solids. To describe the drying process of porous materials, the global capacitance method was used. The application has been made for the drying of ceramic materials in order to obtain kinetic results of loss of mass and heat of the same. Different cases were simulated by varying the shape of the body, from which the kinetics of drying (loss of moisture) and heating of the solid (temperature increase) were obtained. It was observed that the process of moisture loss occurs at a slower rate than the heating of the ceramic material, because its thermal diffusivity is much higher than mass diffusivity, and that the shape of the solid, particularly its area / volume ratio strongly affects The phenomena of heat and mass transport.

Orientador : Yong Kun Park
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Mestrado
Mestre em Ciência de Alimentos

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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior
The objective of this work was to evaluate the effect of supplements feeding on growth of calves grazing a Panicum maximum cv. Momba?a pasture during the dry season. The experimental design was a randomized blocks with three treatments and three replications. The treatments were: mineral salt ad libidum; multiple mixture (MM) fed at 0.2% of live weight (PV); and, concentrate feed (SC) fed at 0.7% of PV. Thirty six weaned calves averaging eight months and 192 kg of initial live weight were utilized. The masses and pasture components, nutritive value and rate of forage growth were evaluated. Animal performance was measured as average daily gain (ADG) and live weight gain (LWG). The supplemental feeding was adjusted after weighing. There was no difference between periods for forage mass and leaf: stem ratio. The highest values for forage green mass, leaf blades mass and stem percentage were observed in the first trial period. The canopy height and the available forage on offer did not differ among treatments. The percentage of dead was higher for the last periods of evaluation. The leaf: stem ratio and the leaf percentage were greater in the second period. There was significant difference (p<0,05) among treatments for the ADG and were 250, 460 and 770 g/day for salt, MM and SC, respectively. The biggest LWG was observed in the treatment SC. contents of PB, DIVMO, NDF and LDA on leaf blades, thatched roofs and dead material dead not differ among treatments. The highest GPV was observed in the SC treatment. The contents of PB, DIVMO, NDF and LDA for leaf blades stem and dead material did not differ among treatments. Independent of the use supplements , it is possible to keep steers gaining weight, during dry season, since the stocking rate is appropriately adjusted
O objetivo deste trabalho foi avaliar o efeito de suplementos na recria de bovinos em pastos de Panicum maximum cv. Momba?a na ?poca seca. Utilizou-se o delineamento experimental de blocos ao acaso, com tr?s tratamentos e tr?s repeti??es. Os tratamentos constitu?ram-se de: sal mineral ? vontade; mistura m?ltipla (MM), fornecida a 0,2% do peso vivo (PV); e, suplemento concentrado (SC), fornecido a 0,7% do PV. Foram utilizados 36 bezerros desmamados, com idade m?dia de oito meses e peso m?dio inicial de 192 kg. Mensalmente, os pastos foram amostrados para as estimativas de altura, massa de forragem (MF), massa de forragem verde (MFV), massa de l?mina foliar (MLF), porcentagens de folha (PF), colmo (PC) e morto (PM), rela??o folha:colmo (RFC) e folha:n?o folha, oferta de forragem e taxa de ac?mulo de forragem (TAF), sendo os dados agrupados em quatro per?odos. Os animais foram pesados a cada 28 dias e a produ??o animal foi avaliada quanto ao ganho m?dio di?rio (GMD) e ganho de peso vivo por ?rea (GPV). A quantidade de suplemento foi ajustada a cada pesagem. N?o houve diferen?a entre per?odos para a massa de forragem e rela??o folha:colmo. Os maiores valores para massa de forragem verde, massa de l?mina foliar e porcentagem de colmo foram observados no primeiro per?odo de avalia??o. A altura do dossel e a oferta de forragem n?o diferiram entre os tratamentos. A porcentagem de material morto foi maior nos ?ltimos per?odos de avalia??o. A rela??o folha:n?o folha e a porcentagem de l?mina foliar foram maiores no segundo per?odo. O GMD foi de 250, 460 e 770 g/animal/dia, respectivamente, para sal, MM e SC. O maior GPV foi observado no tratamento SC. Os teores de PB, DIVMO, FDN e LDA nas l?minas foliares, colmo e material morto n?o diferiram entre os tratamentos. Independente do uso de suplementos, ? poss?vel manter o ganho de peso dos animais durante a esta??o seca, desde que a taxa de lota??o seja ajustada de forma adequada

La contamination bactérienne des concentrés plaquettaires (CPs) représente le risque le plus fréquent d'infection transmise par transfusion. Malgré les progrès techniques accomplis dans le dépistage des agents infectieux, le risque de transmission de ces agents par transfusion ne peut encore être considéré comme totalement maîtrisé. Nous avons pu développer une méthode de détection par la technique de MALDI-TOF. Notre protocole permet une détection dans un délai de 8 heures à de faibles concentrations bactériennes.Nous avons évalué les performances d’un automate d’hémoculture, le VersaTREK, par rapport au Bactec, qui est fréquemment utilisé par les centres de transfusion. Nos résultats démontrent son intérêt dans la détection de la contamination bactérienne des CPs. Afin de caractériser l’origine de la contamination bactérienne, nous avons comparé, dans une étude rétrospective, les espèces bactériennes identifiées dans les hémocultures des patients de l’hôpital de la Timone, à celles identifiées dans des poches de CPs contaminés. Les espèces responsables de la contamination des CPs sont essentiellement issues de la flore cutanée. Elles sont donc différentes des espèces responsables d’épisodes de bactériémies.Ainsi, ce travail propose de nouvelles méthodes de détection de la contamination bactérienne. La mise en œuvre de ces nouvelles stratégies de diagnostic couplées à une meilleure connaissance de la prévalence et de l’origine de la contamination bactérienne des CPs pourrait permettre d’améliorer davantage la prévention et la réduction de la morbi-mortalité induite par une transfusion de CPs
Bacterial contamination of platelet concentrates (PCs) is the most common risk of transfusion-transmitted infection. Despite better control of the elements of the technical progress achieved in the detection of infectious agents, the risk of transmission of these agents by transfusion cannot yet be considered as totally mastered. We have developed a method for detecting PCs contamination by MALDI-TOF. To the best of our knowledge, this is the first time that MALDI-TOF is used in the detection of microbial contamination in a complex medium such as PCs. Our protocol allows detection within 8 hours at low bacterial concentrations. In a second step, we evaluated the performance of a blood culture machine, VersaTREK®, compared to Bactec®, frequently used by transfusion centers. Our results demonstrate its interest in the detection of bacterial contamination of PCs. In order to characterize the origin of bacterial contamination of PCs, we compared in a retrospective study, bacterial species identified in patients' blood cultures treated at the Timone hospital, with those identified in infected PC units. The species responsible for the contamination of the PCs are mainly resulting from the cutaneous flora and are therefore different from the species responsible for episodes of bacteremia.Thus, this work proposes new methods for detecting bacterial contamination. The implementation of these new diagnostic strategies coupled with a better knowledge of the prevalence and origin of bacterial contamination of PCs could further improve the prevention and reduction of both morbidity and mortality induced by blood transfusion of PCs

Дисертаційна робота присвячена виявленню закономірностей процесу концентрування водних розчинів сульфатної кислоти випаровуванням в потік нейтрального газу за умов зовнішнього підведення теплоти. Такий процес дозволяє понизити температуру теплоносія, який використовується для нагрівання розчину кислоти, і відповідно відмовитись від дефіцитних видів палива. У дисертації представлено результати експериментального дослідження впливу нейтрального газу та режимних параметрів процесу на інтенсивність процесу концентрування розчину. Запропоновано методику визначення швидкості випаровування розчину кислоти та експериментально встановлено її залежності від складу розчину. Проведено дослідження тепло- і масопереносу при концентруванні, визначено величини потоків теплоти при теплообміні між рідкою і газовими фазами, встановлено умови, за яких теплообмінний потік міняє напрям. Отримано емпіричні рівняння для розрахунку швидкості випаровування розчину кислоти та коефіцієнтів тепло – і масовіддачі при його концентруванні. У результаті моделювання зазначеного процесу встановлено закономірності зміни складу розчину в часі для періодичного процесу і від величини потоку початкового розчину для безперервного процесу при різних режимах концентрування. Розроблено пропозиції щодо апаратурного оформлення цього процесу на основі типового ємнісного апарату і апарату плівкового типу, а також методику розрахунку періодичного і безперервного процесів концентрування в ємнісному концентраторі.
Диссертационная работа посвящена выявлению закономерностей процесса концентрирования водных растворов серной кислоты испарением в поток нейтрального газа при внешнем подводе теплоты. Такой процесс позволяет снизить температуру используемого для нагревания раствора кислоты теплоносителя, и соответственно отказаться от дефицитных видов топлива. В диссертации представлены результаты экспериментального исследования влияния нейтрального газа и режимных параметров процесса на интенсивность процесса концентрирования раствора. Предложена методика определения скорости испарения раствора кислоты и экспериментально установлены ее зависимости от состава раствора. Проведено исследование тепло- и массопереноса при концентрировании, определены величины потоков теплоты при теплообмене между жидкой и газовыми фазами, установлены условия, при которых теплообменный поток меняет направление. Получены эмпирические уравнения для расчета скорости испарения раствора кислоты и коэффициентов тепло- и массоотдачи при его концентрировании. В результате моделирования отмеченного процесса установлены закономерности изменения состава раствора во времени для периодического процесса и от величины потока начального раствора для непрерывного процесса при разных режимах концентрирования. Разработаны предложения по аппаратурному оформлению этого процесса на основе унифицированного емкостного аппарата и аппарата пленочного типа, а также методику расчета периодического и непрерывного процессов концентрирования в емкостном концентраторе.
The thesis presents the results of an experimental investigation of the influence of indifferent gas, which is injected into the free space above acid solution or bubbled through it, and operating conditions of the process on the intensity of the solution concentration process. A method of determining the acid solution evaporation rate has been suggested, and its dependences on the solution composition that confirm the presence of the critical acid concentration in the solution, at which the acid (H2SO4 monohydrate) starts evaporating along with water, have been determined experimentally. It has been shown that, within the range of solution concentration values before and after the critical concentration, the dependences of the evaporation rate on the solution composition are of a different nature. The study of concentration heat transfer and mass transfer has been carried out, the heat flux values at heat exchange between liquid and gaseous phases have been determined, and the conditions, at which the heat-exchange flow changes its direction, have been ascertained. By means of modelling the aforementioned process, the regularities of the solution composition change over time for a batch process and the dependences on the initial solution flow value for a continuous process at different concentration conditions have been determined. The suggestions have been made concerning the equipment needed for this process on the basis of a standard capacitive apparatus and a film apparatus, as well as the methods of calculating the batch and continuous concentration processes in the capacitive concentrator.

Au cours de ces dernières décennies, des études ont étés menées pour identifier plusieurs traceurs des matériaux du cycle du combustible nucléaire, dans le cadre de la lutte contre la prolifération nucléaire. Ces matériaux sont généralement collectés lors d’inspections dans des installations nucléaires, ou saisis lors de contrôles de trafics illicites. Les informations fournies par ces traceurs sont parcellaires et ne permettent pas de déterminer avec exactitude la provenance et l’historique industriel de ces matériaux.Le but de ce travail de thèse est de démontrer le potentiel de l’utilisation des isotopes du molybdène pour le traçage des matériaux du cycle du combustible nucléaire. Le choix s’est porté sur le molybdène car en raison de la similarité de leurs propriétés chimiques, le molybdène et l’uranium sont étroitement associés dans les minerais d’uranium et tout au long de la chaîne de purification de l’uranium. L’étude s’est focalisée sur une partie de l’amont du cycle du combustible, depuis l’extraction des minerais d’uranium jusqu’à la production des concentrés miniers d’uranium : divers procédés physiques et chimiques sont appliqués, à la fois pour purifier l’uranium et abaisser la concentration en molybdène.Au cours de cette étude, une nouvelle méthode de séparation du molybdène a été développée pour caractériser sa composition isotopique dans des minerais, minéraux et concentrés miniers d’uranium. La variabilité des compositions isotopiques du molybdène dans un gisement d’uranium est principalement due aux mécanismes d’adsorption et/ou de précipitation du molybdène. Les gisements magmatiques et sédimentaires ont des compositions isotopiques différentes, ce qui permet ainsi leurs distinctions. Les concentrés miniers d’uranium produits à partir de ces deux types de gisements ont des compositions isotopiques similaires aux minerais. Ces résultats soulignent ainsi le potentiel des isotopes du molybdène comme traceur des origines des concentrés miniers d’uranium. Cependant, un fractionnement des isotopes du molybdène a été établi lors de la production des concentrés miniers d’uranium pour deux usines au Niger. Les procédés de purification de l’uranium tels que la lixiviation, l’extraction par solvant et la précipitation ont été reproduits en laboratoire sur des échantillons réels pour expliquer le fractionnement isotopique du molybdène lors de la production des concentrés miniers. Au cours de ces procédés, le fractionnement peut être positif (lixiviation), négatif (extraction par solvant, précipitation à l’eau oxygénée) ou nul (précipitation à l’ammoniaque). Dans le cas des échantillons du Niger, la somme de ces procédés est négative, dans le sens des données expérimentales que nous avons obtenues, démontrant ainsi également le potentiel de l’utilisation des isotopes du molybdène comme traceur des procédés de transformations des matériaux du cycle du combustible nucléaire
Nuclear forensics aims at determining the age, provenance as well as industrial or storage history of uranium ores and uranium ore concentrates that are part of the nuclear fuel cycle. Several potential tracers have already been identified for this purpose. However, these tracers are not providing always unambiguous information. This study is focused on establishing Mo isotopes as a new tracer of uranium ore provenance and of ore processing for its application in nuclear forensics. Molybdenum and uranium share a number of common geochemical properties. In the nuclear fuel cycle, molybdenum is an impurity that is difficult to separate during uranium extraction and purification processes, while its concentration is required to be lower than some specification limits. We focused this study on the first part of the nuclear fuel cycle, from the uranium ores extraction to the production of uranium ore concentrates.We developed an enhanced separation method for Mo from a uranium-rich matrix (uranium ores, uranium minerals, uranium ore concentrates) in order to analyze the mass fractionation induced by processes typical of the nuclear fuel cycle. Molybdenum isotopic compositions in uranium ores depend of adsorption and precipitation processes. The δ98Mo values of sedimentary uranium ores is shifted to negative values relative to magmatic ores. This provides a means of distinguishing these types of uranium ores. Uranium ores concentrates produced from both uranium ore natures (magmatic and sedimentary) have Mo isotope compositions similar to the uranium ores. These results suggest that molybdenum isotopes have a strong potential of as a tracer for identifying the origin of the uranium ore concentrates. However, Mo isotopes fractionations were established during the production of uranium ore concentrates in the both Niger mills. We reproduced in laboratory the lixiviation, solvent extraction and precipitation processes to explain these observations. The Mo isotopes fractionation is positive for the lixiviation process, negative for the solvent extraction and precipitation with hydrogen peroxide, and null for ammonia precipitation. In the case of the Niger samples, the sum of these processes is negative and agrees with our experimental data. Mo isotopes have a strong potential as a tracer for identifying the origin and transformation of uranium in the nuclear fuel cycle, in the framework of nuclear forensics

Dans un avion, un hélicoptère ou un lanceur actuel, des milliers de capteurs, pour la plupart non critiques sont utilisés pour la mesure de divers paramètres (températures, pressions, positions...) Les résultats sont ensuite acheminés par des fils vers les calculateurs de bord qui les traitent. Ceci implique la mise en place de centaines de kilomètres de câbles (500 km pour un avion de ligne) dont le volume est considérable. Il en résulte une grande complexité de conception et de fabrication, des problèmes de fiabilité, notamment au niveau des connexions, et une masse importante. Par ailleurs l'instrumentation de certaines zones est impossible car leur câblage est difficilement envisageable par manque d'espace. En outre, s'il est souvent intéressant d'installer de nouveaux capteurs pour faire évoluer un aéronef ancien, l'installation des câbles nécessaires implique un démantèlement partiel, problématique et coûteux, de l'appareil. Pour résoudre ces problèmes, une idée innovante a émergé chez les industriels de l'aéronautique : commencer à remplacer les réseaux filaires reliant les capteurs d'un aéronef et leur centre de décision par des réseaux sans fil. Les technologies de communication sans fil sont aujourd'hui largement utilisées dans les marchés de l'électronique de grande consommation. Elles commencent également à être déployées pour des applications industrielles comme l'automobile ou le relevé à distance de compteurs domestiques. Cependant, remplacer des câbles par des ondes représente un défi technologique considérable comme la propagation en milieu confiné, la sécurité, la sureté de fonctionnement, la fiabilité ou la compatibilité électromagnétique. Cette thèse est motivée d'une part par l'avancée non négligeable dans le milieu aérospatial que pourrait être l'établissement d'un réseau sans fil à bord d'aéronefs dans la résolution de problématique classiques comme l'allégement et l'instrumentation. Il en résulterait donc : * Une meilleure connaissance de l'environnement et de la santé de l'aéronef * Un gain sur le poids. * Un gain en flexibilité. * Un gain en malléabilité et en évolutivité. * Un gain sur la complexité. * Un gain sur la fiabilité D'autre part, étant donnée la complexité de la conception de ce réseau de capteur sans fil, il a été nécessaire d'appliquer une méthodologie évolutive et adaptée mais inspirée de l'ingénierie système. Il est envisageable, vu le nombre de sous-systèmes à considérer, que cette méthodologie soit réutilisable pour d'autre cas pratiques. Une étude aussi complète que possible a été réalisée autour de l'existant déjà établi sur le sujet. En effet, on peut en lisant ce mémoire de thèse avoir une idée assez précise de ce qui a été fait. Une liste a été dressée de toutes les technologies sans fil en indiquant leur état de maturité, leurs avantages et leurs inconvénients afin de préciser les choix possibles et les raisons de ces choix. Des projets de capteurs sans fil ont été réalisés, des technologies sans fil performantes et personnalisables ont été développées et arrivent à maturité dans des secteurs variés tels que la domotique, la santé, l'automobile ou même l'aéronautique. Cependant aucun capteur sans fil n'a été véritablement installé en milieu aérospatial car de nombreux verrous technologiques n'ont pas été levés. Fort des expériences passées, et de la maturité qu'ont prise certaines technologies, des conclusions ont été tirées des projets antérieurs afin de tendre vers des solutions plus viables. Une fois identifiés, les verrous technologiques ont été isolés. Une personnalisation de notre solution a été à envisager afin de remédier tant que faire se peut à ces points bloquants avec les moyens mis à disposition. La méthodologie appliquée nous a permis d'identifier un maximum de contraintes, besoins et exigences pour mieux focaliser les efforts d'innovation sur les plus importantes et choisir ainsi les technologies les plus indiquées.

碩士
國立臺灣大學
工程科學及海洋工程學研究所
92
The purpose of this study was focused on using the inner support and the additional centralization mass to refashion the fixed end sequare homogenous plate , and the subsequent improvement of the sound radiaton . We uses the radiation mode to find out the fundamental modes of more effective sound radiation . Then , the modes was broken by inner support with subsequently improved by additional centralization mass . All the supporting postion , the loading size and position of the additional mass are the topic of our study . The mathematical model was analyzed by semi-analytical method . We use the characteristics that the close form derived from the fundamental function and resonance frequency of homogenous plate , combining with structural dynamic and matrix , to deduce the result that the modified fundamental function and resonance frequency will save the CPU time effectively . We had proven it by simple experiment . The results revealed that , for single frequency noise , the plate vibration can be improved immediately and effectively if we used the refashion technology to change the resonance frequency for more than 5 Hz . Besides , it also can be applied to noise with arbitrary frequency to find out the best refashion position . We had proven that , even though with the different resonance frequency and noise peak frequency , the refashioned plate did reduce the general sound radiation effectively .

碩士
國立成功大學
系統及船舶機電工程學系碩博士班
94
The purpose of this thesis is to extend the continuous-mass transfer matrix method (CTMM) to determine the natural frequencies and associated mode shapes of the uniform or non-uniform Timoshenko beams carrying any number of point masses, rotary inertias, translational springs and rotational springs with various classical or non-classical boundary conditions. To this end, a continuous Timoshenko beam is subdivided into several beam segments with any two adjacent beam segments connected by a node, and then each kind of concentrated elements is attached to each node. So, it is easy to establish the mathematical model of a uniform or non-uniform Timoshenko beam with various boundary conditions by only adjusting the cross-sectional area and length of each beam segment, and the associated physical quantity for each kind of concentrated elements. Thus, for a free-free beam, one requires only to set each of the stiffness constant of translational springs and rotational springs at its two ends to be equal to zero. In addition, the shear deformation and rotary inertia effects, the natural frequencies and associated mode shapes of the uniform or non-uniform beam carrying various concentrated elements are determined with Euler beam theory and Timoshenko beam theory.

A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy. 27 January 2016.
The direct and inverse spectral problems for an inhomogeneous string with an interval of zero density and a concentrated mass at the end point moving with damping are investigated. The partial differential equation is mapped into an ordinary differential equation using separation of variables which in turn is transformed into a Sturm-Liouville differential equation with boundary conditions depending on these parathion variable. The Marchenko approach is employed in the inverse problem to recover the potential, density and other parameters from the knowledge of the two spectra and length of the string.

Very selective and highly sensitive ways to detect peptides or proteins of interest remain important goals in proteomics applications. This dissertation focuses on the use of amphiphilic polymeric materials that self-assemble as reverse micelles in apolar solvents as part of a liquid-liquid extraction methodology to selectively extract and concentrate peptides from aqueous solutions. After extraction the polymer-peptide mixtures are amenable to direct analysis by mass spectrometry (MS) using matrix-assisted laser desorption/ionization (MALDI). The polymeric materials that self-assemble in apolar solvents have charged interiors that allow oppositely-charged peptides to readily migrate into the aggregate's core, while similarly-charged peptides do not. This charge complementarity can be controlled by varying aqueous phase pH such that peptides having a narrow range of a pI values can be selectively isolated. Insights into the extraction mechanism and how these materials can potentially open the way for multidimensional separations were also studied. Furthermore, amino acid-specific covalent labels are introduced inside the reverse micelles to selectively react with the extracted peptides having the amino acid of interest. This reaction leads to a mass signature that can be used to identify peptides with amino acids of interest. In addition, bulk ampholytic gels and small commercial surfactants were investigated as extraction materials. Overall, our results reveal that the amphiphilic polymeric reverse micelles are far superior for selectively and efficiently extracting peptides from complex mixtures.

碩士
世新大學
傳播管理學研究所(含碩專班)
103
In recent years, aesthetic medicine care product was famous in Taiwan, The doctor made a low-sensitive care product and not added to preservative. This product demand successes in aesthetic medicine care product market, the market worth to 2 billion year, and stable grew up. The drugstore said about 20% customer most like went to drugstore than department store buy aesthetic medicine care product. Cosmed store said aesthetic medicine care product grow up 10% last year, especial under 25 years people grow up about 50%. Product positioning was market positioning core point, the company chose targeting market had to set up product positioning and try to attract targeting customers. The product positioning in order to increase product sales, it was company planed marketing strategy important data, how to find customer demands and thoughts was the study point. Integrated qualitative research and created attempt, the research purposes： 1.Using IBLT technique and laddering technique guide customer what thinking about Hyaluronic Acid & Vitamin Repair Mask. 2.Combing Means-end chains theory and laddering technique how about Hyaluronic Acid & Vitamin Repair Mask attributes, consequence, value and functional value, psychology value. 3.Induction customer mind map and consensus map about Hyaluronic Acid & Vitamin Repair Mask, and purpose product positioning.