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1
Cintra, Patricia. "Parâmetros nutricionais e hematológicos de ratos alimentados com soja (Glycine Max L.) geneticamente modificada". Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/9/9131/tde-20122017-150702/.
Testo completoAbstract (sommario):
No presente trabalho foi estudado o efeito do consumo de soja geneticamente modificada e de sua parental em parâmetros nutricionais e hematológicos em ratos em crescimento. Farinha de soja, desengordurada e autoclavada, foi incorporada em rações experimentais: 12% de proteína para o 1° ensaio e 10% para 2° ensaio. As rações com soja foram suplementadas com aminoácidos essenciais (Ieucina, lisina, metionina e vali na) no 2° ensaio, devido a menor concentração desses aminoácidos nas rações do 1° ensaio quando comparadas ao grupo controle, perfil confirmado pelo aminograma. Ratos Wistar (n=64) foram alimentados, ad libitum, com rações controle (AIN-93G) e rações com a farinha de soja por 28 (1° ensaio) e 32 dias (2° ensaio). Para avaliação do aproveitamento biológico da proteína da dieta e da qualidade protéica, foram realizadas análises de nitrogênio na carcaça dos animais, nas fezes e na urina que foram coletadas ao longo de 2 períodos de balanço de 6 dias cada ensaio. Os parâmetros nutricionais avaliados foram : Coeficiente de eficácia alimentar (CEA), Coeficiente de eficácia protéica (PER), Coeficiente de eficiência líquida da proteína (NPR), Valor biológico da proteína (BV), Coeficiente de utilização líquida da proteína (NPU), digestibilidade protéica e o \"Escore químico corrigido pela digestibilidade real da proteína\". Para avaliação do estado nutricional foram avaliadas as concentrações de albumina, proteínas totais e IGF-1 no plasma. Como parâmetros hematológicos, foram avaliados o hemograma completo, mielograma e esplenograma. Os resultados obtidos demonstraram que animais alimentados com soja GM e sua parental apresentaram desenvolvimento semelhante ao grupo controle (caseína). Os valores de CEP e NPR encontrados nos 2 ensaios mostram que a proteína de soja é nutricionalmente adequada. A oferta protéica de 10% com suplementação com aminoácidos essenciais favoreceu no desenvolvimento dos animais, visto que foi observado aumento de peso em média de 50g, PER e NPR melhores quando comparados com a oferta protéica de 12% sem suplementação. Nos dois ensaios, os valores de digestibilidade dos grupos alimentados com soja foram inferiores aos do grupo controle, resultado evidenciado pela maior dificuldade das enzimas digestivas em digerirem a proteína vegetal, maior perda de aminoácidos endógenos e quantidade de fibra insolúvel presente na soja. O valor de POCAA de 85% demonstra bom aproveitamento dos grupos com soja. Não houve diferença estatística nos parâmetros plasmáticos estudados, bem como nos resultados hematológicos sugerindo que o consumo de soja, convencional ou GM, não altera o estado nutricional dos animais.In the present work, the effects of genetically modified (GM) soybean and its parental on nutritional and hematological parameters in growing rats were studied. Autoclaved, fat-free soybean flour was added to experimental diets: 12% protein in the first assay and 10% in the second assay. The soybean diets were supplemented with essential amino acids (Ieucine, Iysine, methionine and valine) in the second assay, since such amino acids presented a lower concentration in the diets of the first experiment, as confirmed by the aminogram. Wistar rats (n= 64) were fed a control diet (AIN-93G) and diets supplemented with soybean flour (parental and GM) ad libitum over 28 days (1st experiment) and 32 days (2nd experiment). For evaluating the biological utilization of dietary protein and protein quality, nitrogen analyses were carried out on the animal carcasses, feces and urine. Feces and urine were collected along two 6-day periods within each assay. The following nutritional parameters were evaluated: feed efficiency ratio (FER), protein efficiency ratio (PER), net protein ratio (NPR), biological value (BV), net protein utilization (NPU), protein digestibility and protein digestibility corrected by amino acid (POCM) score. For evaluating the nutritional status, plasma albumin, total proteins and IGF-1 were analysed. Complete hemogram, myelogram and splenogram were used as hematological parameters. The results indicate that animals fed the GM soybean and its parental showed a similar growth rate to the control group (casein). PER and NPR values found in both assays show that soybean protein is nutritionally adequate. A diet containing 10% protein supplemented with essential amino acids favored the growth of the animals in comparison to a diet containing 12% protein without amino acid supplementation. In both assays, the protein digestibility in soybean-fed groups was lower than in the control group, a result evidenced by a greater difficulty of enzymes in digesting vegetal proteins, a greater loss of endogenous amino acids and the presence of insoluble dietary fiber in the soybean. A POCM value of 85% showed a good protein utilization in the soybean-fed groups. No statistically significant differences were observed in the plasmatic and hematological parameters among the groups, suggesting that consumption of soybean (either GM or parental) does not alter the nutritional status of the animals.
2
Haus, Andrea. "Classroom experiments ökonomische Experimente als Unterrichtsmethode". Schwalbach/Ts. Wochenschau-Verl, 2009. http://d-nb.info/995506701/04.
Testo completo
3
Šikula, Pavel. "Analýza rizik ve vztahu k různým zaměřením ekonomických experimentů". Master's thesis, Vysoké učení technické v Brně. Ústav soudního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-233065.
Testo completoAbstract (sommario):
The diploma thesis deals with analysis of risks in relation to various focus (or types) of economic experiments. On the basis of background research suggests entirely new classification of economic experiments and subsequently examines general structure of economic experiment. Performed analysis then identifies major risks of experimental economics, analyses them and proposes possible countermeasures. Outputs of the work substantially enrich and extend current theory. Their utilization is expected in theory and practice, for purpose of scientific research or specific objectives of companies and institutions.
4
Sexton, Christine June. "Designing industrial experiments with restricted experimental resources". Thesis, University of Southampton, 1998. https://eprints.soton.ac.uk/50646/.
Testo completoAbstract (sommario):
This thesis presents two procedures for designing industrial experiments with restricted experimental resources. First, a two-stage approach is developed using the D- and Ds-optimality criteria in combination, to focus information into the effects of most relevance to the robust engineering design of a product. The method is demonstrated by finding a design for a study on gas sensors. The second approach forms the major contribution of this thesis. Semicontrolled experiments are developed for use in situations where the factor values cannot be pre-determined, although the way in which they are combined with other factors can be controlled. This situation arises when the costs of measuring components in a product, or of making one-off components, prevents the use of a conventional factorial experiment. In the method, samples of the components are obtained and features of interest are measured. The components are then combined in products for testing to give combinations of the factor values which will maximise the information on the factorial effects under investigation. This method is particularly useful when derived factors, that is, factors defined as functions of variables from one or more components, are of engineering interest. An exchange algorithm is presented for finding optimal designs for semi-controlled experiments and demonstrated on a small pilot study on a gear pump. An extension of the algorithm is provided to design experiments when some factors can be pre-set in the conventional way, but others cannot. The issues of power and the size of experiment for a semi-controlled study are also addressed through simulated experiments.
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Luiz, Rodrigo de Lima [UNESP]. "Experimentos de eletrostática como metodologia de aprendizagem significativa". Universidade Estadual Paulista (UNESP), 2018. http://hdl.handle.net/11449/158320.
Testo completoAbstract (sommario):
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Neste trabalho, foi pesquisada uma forma alternativa de aplicação de experimentos em sala de aula, na qual os alunos foram responsáveis pela confecção deles e não meros expectadores que observaram o professor realizar a atividade experimental. Assim, os estudantes produziram, executaram e tiraram suas conclusões acerca das atividades propostas. Propôs-se, neste trabalho, a aplicação de uma sequência didática para abordar eletrostática utilizando atividades experimentais, como metodologia de aprendizagem significativa, proposta por David Ausubel. Antes da realização dos experimentos, o tema foi contextualizado através de vídeos que mostravam situações intrigantes no cotidiano dos alunos, envolvendo eletrostática. Também foi abordada a história da eletricidade com suas principais descobertas e como os conceitos científicos foram evoluindo ao longo do tempo. Em seguida, utilizando materiais de baixo custo e fáceis de serem encontrados e seguindo roteiros experimentais, os alunos construíram experimentos que permitiram a verificação dos três processos de eletrização: atrito, contato e indução. Também, verificaram a distribuição de cargas em condutores em equilíbrio eletrostático, a blindagem eletrostática e o poder das pontas. O trabalho visou despertar o interesse e motivação dos alunos nas aulas de Física, desenvolvendo suas habilidades em seguir roteiros simples, coletar e analisar dados, além de aplicar os conceitos, abordados em sala, em situações de seu cotidiano.
In this work, an alternative way of applying experiments in the classroom has been investigated, in which the students were responsible by their confections and not mere spectators who observed the teacher to perform an experimental activity. Thus, students produced, performed, and concluded on the proposed activities. It was proposed, in this work, the application of a Didactic Sequence to approach electrostatic using experimental activities, as significant learning methodology, proposed by David Ausubel. Before the experiments, the theme was contextualized through videos that showed intriguing situations in the daily life of students, involving electrostatics. It was also discussed the electricity history with its main discoveries, and how scientific concepts were developed over time. Then, using inexpensive, easy-to-find materials and following experimental script, the students constructed experiments that allowed the verification of the three electrification processes: friction, contact and induction. Also, they verified the charges distribution in conductors in electrostatic equilibrium, the electrostatic shield and the power of the tips. The aim of this work was to arouse student’s interest and motivation in physics classes, developing their skills in following simple scripts, collecting and analyzing data, and applying the concepts, addressed in the classroom, in everyday situations.
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Kang, Lulu. "Computer and physical experiments: design, modeling, and multivariate interpolation". Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/34805.
Testo completoAbstract (sommario):
Many problems in science and engineering are solved through experimental investigations. Because experiments can be costly and time consuming, it is important to efficiently design the experiment so that maximum information about the problem can be obtained. It is also important to devise efficient statistical methods to analyze the experimental data so that none of the information is lost. This thesis makes contributions on several aspects in the field of design and analysis of experiments. It consists of two parts. The first part focuses on physical experiments, and the second part on computer experiments.
The first part on physical experiments contains three works. The first work develops Bayesian experimental designs for robustness studies, which can be applied in industries for quality improvement. The existing methods rely on modifying effect hierarchy principle to give more importance to control-by-noise interactions, which can violate the true effect order of a system because the order should not depend on the objective of an experiment. The proposed Bayesian approach uses a prior distribution to capture the effect hierarchy property and then uses an optimal design criterion to satisfy the robustness objectives. The second work extends the above Bayesian approach to blocked experimental designs. The third work proposes a new modeling and design strategy for mixture-of-mixtures experiments and applies it in the optimization of Pringles potato crisps. The proposed model substantially reduces the number of parameters in the existing multiple-Scheffé model and thus, helps the engineers to design much smaller experiments.
The second part on computer experiments introduces two new methods for analyzing the data. The first is an interpolation method called regression-based inverse distance weighting (RIDW) method, which is shown to overcome some of the computational and numerical problems associated with kriging, particularly in dealing with large data and/or high dimensional problems. In the second work, we introduce a general nonparametric regression method, called kernel sum regression. More importantly, we make an interesting discovery by showing that a particular form of this regression method becomes an interpolation method, which can be used to analyze computer experiments with deterministic outputs.
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Ferreira, Danilo Cardoso [UNESP]. "Elaboração de um material didático aplicado ao ensino de física para utilização do experimento virtual da dupla fenda". Universidade Estadual Paulista (UNESP), 2015. http://hdl.handle.net/11449/132892.
Testo completoAbstract (sommario):
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
A mecânica quântica é uma das áreas da Física que surgiu em meados de 1900 e permanece em desenvolvimento até os dias atuais. Diversos aparatos tecnológicos são consequência deste importante ramo da Física que também contribui com a Medicina, Matemática, Filosofia, Literatura e Biologia. Logo, é imprescindível que o contato com esta ciência ocorra no contexto do ensino médio. Para inserir o estudante no mundo da mecânica quântica, isto é, na física do infinitamente pequeno, o aluno deve abandonar o pensamento clássico e pensar em termos do comportamento quântico e do indeterminismo no processo de medida, isto é, desenvolver a capacidade de abstração. Sendo este, o objetivo deste trabalho. Para tanto, foi escolhido o experimento da dupla fenda que permite trabalhar com a dualidade onda-partícula do elétron e do fóton. Por meio deste experimento, o aluno pode ser inserido paulatinamente numa trajetória rumo a descrição quântica necessária para o exame dos fenômenos subatômicos. A análise experimental é cuidadosamente realizada com o auxílio de laboratórios virtuais, disponibilizados gratuitamente em sítios eletrônicos, os quais representam um recurso que permite realizar procedimentos experimentais que necessitariam de grande aparato laboratorial. O experimento da dupla fenda é analisado em três etapas, relatadas a seguir: (i) a dupla fenda com partículas clássicas; (ii) a dupla fenda com ondas clássicas e; (iii) a dupla fenda com objetos quânticos como elétrons e fótons. O objetivo é demonstrar o comportamento dual do elétron. Posteriormente, para concluir de forma precisa e justificar o comportamento quântico do elétron é apresentado o princípio da indeterminação de Heisenberg e suas implicações filosóficas. Sendo assim, o objetivo central desta pesquisa é buscar integrar o comportamento quântico, que acontece na escala atômica, principalmente no contexto do ensino médio. Algumas orientações sobre como aplicar este trabalho em outros níveis de ensino aparecem no decorrer do texto e nos apêndices. Apresentando o comportamento dual, onda–partícula, do elétron, a interpretação probabilística e o princípio de incerteza. Acreditamos que o aluno será capaz de compreender um grande número de fenômenos que acontece em escalas que não são do domínio da mecânica clássica quando, em contato com estes temas. Este tema faz parte do conteúdo de física moderna contemporânea que vem sendo abordado em livros textos e vestibulares. Além disso, algumas das novas tecnologias utilizam a física quântica, desde microscópios eletrônicos, nanotecnologia, computação quântica, semicondutores, diodos (incluindo o LED), transistores, computadores, tablets, GPS, satélites, radares, aviões, lasers, scanners de código de barras, sistemas militares de defesa, CD e Blu-Ray players, criptografia, células fotoelétricas, sensores diversos, basicamente, tudo que é eletrônico. Um dos objetivos do trabalho é verificar quais os conhecimentos prévios o corpo discente possui, antes do contato com o conteúdo de física quântica, ou seja, o que faz parte do senso comum sobre este tema. Além disso, pretendemos verificar se o aluno consegue: i) distinguir, no final da aplicação desta pesquisa, que as leis da física em escalas atômicas são diferentes das leis da física clássica, ii) a importância da mecânica quântica na tecnologia e na sociedade.
Quantum mechanics is one of the areas of physics that emerged in mid-1900 and remains in development to the current day. Several technological devices are a result of this important branch of physics that also helps to Medicine, Mathematics, Philosophy, Literature and Biology. Therefore, it is essential that contact with this science occurs at the high school level, what actually occurs in a limited way, when it happens. To place the student in the world of quantum mechanics, that is, the infinitely small of physics, the student must leave the classical thought and think in terms of the quantum behavior and indeterminacy in the measurement process, namely to develop the capacity for abstraction. This is accurately the aim of this work. Thus, the double-slit experiment that lets you work with the wave-particle duality of the electron and the photon was chosen. Through this experiment, students can be gradually inserted on a path toward quantum description necessary for the examination of subatomic phenomena. The experimental analysis is carefully performed with the aid of virtual laboratories, available for free in electronic sites, which represent a resource to perform experimental procedures that would require large laboratory apparatus. The double slit experiment is analyzed in the following three steps, reported: (i) the slit paired with classical particles; (ii) the double slit and with classical waves; (iii) the double slit with quantum objects such as electrons and photons. The goal is to demonstrate the electron dual behavior. Later to complete accurately and justify the electron quantum behavior shows the principle of indeterminacy of Heisenberg and its philosophical implications. Thus, the main objective of this research is to seek to integrate quantum behavior, which takes place at the atomic scale, especially in the high school level. Some guidance on how to apply this work in other levels of education appear throughout the text and in the appendices. Introducing the dual behavior wave-particle, the electron, the probabilistic interpretation and the uncertainty principle. We believe that students will be able to understand a number of phenomena that occurs on scales that are not the classical mechanics of the domain when in contact with these topics. This topic is part of the contemporary modern physics content that is being addressed in texts and entrance exam books. In addition, some of the new technologies using quantum physics, from electronic microscopes, nanotechnology, quantum computing, semiconductors, diodes (including LED), transistors, computers, tablets, GPS, satellites, radar, aircraft, lasers, code scanners bars, military defense systems, CD and Blu-Ray players, encryption, photoelectric cells, various sensors, basically, everything is electronic. One of the goals of the work is to check what prior knowledge the student body has, before contact with quantum physics content, so the part of common sense on this issue. In addition, we intend to verify that the student is able to: i) distinguish, at the end of the application of this research, that the laws of physics at atomic scales are different from the laws of classical physics, ii) the importance of quantum mechanics in technology and society.
8
Heidor, Renato. "Tributirina apresenta atividade quimiopreventiva quando administrada isoladamente, mas não em associação com a vitamina A, em ratos submetidos a modelo de carcinogênese de cólon". Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/9/9132/tde-11072016-110536/.
Testo completoAbstract (sommario):
Avaliou-se a atividade quimiopreventiva da tributirina (TB), e da vitamina A (VA) administradas em associação ou não, antes, durante e após a iniciação em ratos submetidos a modelo de carcinogênese de cólon. Ratos Wistar receberam VA [1 mg/100 g de p.c (grupo VA)], tributirina [200 mg/100 g de p.c (grupo TB)] ou associação de VA com TB (grupo VA+TB). Ratos tratados com óleo de milho e maltodextrina serviram como controle (GC). Avaliou-se a presença de focos de criptas aberrantes (FCA) e sua localização nos cólons, além de danos e do padrão de metilação global do DNA na mucosa colônica. No cólon total, distal e proximal, o grupo TB apresentou menor (p<0,05) número de FCA com 4 ou mais criptas/cm2, considerados mais agressivos, em relação ao GC. Quanto aos danos no DNA, os grupos VA, TB e VA+TB apresentaram cometas de comprimentos menores (p<0,05) em comparação ao GC. Não houve diferenças estatisticamente significantes quanto ao padrão de metilação global do DNA. Assim, TB consiste em agente quimiopreventivo promissor da carcinogênese de cólon quando administrada isoladamente, mas não em associação com a VA. 15Chemopreventive activities of tributyrin (TB) and vitamin A (VA) were administered in combination or not, before, during and after the initiation in rats subjected to carcinogenesis model of colon. Wistar rats received VA [1 mg/100 g of b.w (group VA)], tributyrin [200 mg/100 g of b.w (TB group)] or association of VA with BD (group VA + TB). Rats treated with corn oil and maltodextrin were used as control (GC). The presence of aberrant foci crypts (ACF) was evaluated and their location in colon tissue was determined. In addition, DNA damages and the global pattern of DNA methylation in colonic cells was measured. In total colon as in distal and proximal portions, the TB group presented lower (p <0.05) number of ACF with 4 or more crypts/cm2 in comparison to the GC group. The number of ACF with 4 or more crypts /cm2 was used as criteria of aggressiveness. In relation to the damage of DNA, the VA, VA + TB and TB groups exhibits smaller nucleoids lengths (p <0.05) compared to the GC group. There were no statistically significant differences on the global pattern of DNA methylation. So TB is promising chemopreventive agent in carcinogenesis of the colon when administered alone, but not in combination with the VA.
9
Arunachalam, Subramaniam. "Experimental investigation into superabrasive reaming using design of experiments". Thesis, University of Hertfordshire, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.263025.
Testo completo
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Fernandes, Tais Motta. "Estudo da absorção aparente da clorofila do espinafre em ensaio com cães". Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/9/9132/tde-09012018-165944/.
Testo completoAbstract (sommario):
O interesse pela clorofila vem crescendo recentemente devido a divulgação de dados que atribuem a esta substância muitos efeitos benéficos à saúde, introduzindo a possibilidade desta molécula oferecer proteção contra o desenvolvimento de doenças crônico-degenerativas e cânceres, agindo como um antioxidante e inibindo a mutagênese. Entretanto, as evidências científicas destas ações são ainda controversas. Perguntas estão surgindo a cerca do local de ocorrência de tais propriedades, se no intestino, antes da absorção, ou se devido a uma ação sistêmica, após absorção. O objetivo deste trabalho foi estudar as mudanças químicas da clorofila durante sua passagem pelo trato gastrointestinal, a absorção aparente e a detecção de derivados da clorofila no sangue. O estudo foi realizado durante 10 dias com 12 cães (Canis familiaris) divididos em 2 grupos. O grupo controle recebeu uma dieta comercial atendendo as exigências nutricionais, enquanto que o grupo teste recebeu a mesma dieta adicionada de 0,8% de espinafre liofilizado e 0,35% de óxido do cromo (como um indicador não absorvível). Foi realizada coleta parcial das fezes e após análise, a absorção aparente foi calculada. Em um segundo ensaio, o sangue foi coletado em 0, 15, 30, 45, 60, 90, 120 e 150 minutos após a ingestão da dieta que continha 10% de espinafre liofilizado. Os pigmentos do espinafre, da dieta, das fezes e do sangue foram extraídos com acetona 80%, isolados e quantificados por CLAE. Os resultados mostraram que a feofitinização foi a via predominante. Somente feofitinas a e b foram encontradas nas fezes. A absorção aparente da clorofila variou entre 4 e 6%. Entretanto, não foi possível detectar a presença de clorofila nem de seus derivados no plasma sanguíneo. Estes achados sugerem que os eventuais efeitos benéficos da clorofila devem ocorrer predominantemente no intestino e caso haja alguma passagem para o sangue, esta molécula parece ser rapidamente metabolizada a fim de prevenir efeitos tóxicos relacionados com a atividade fotossintética.In recent years there has been a growing interest on chlorophyll due to disclosing reports attributing to this substance manifold health benefits, introducing the possibility of this molecule protecting against the development of chronic-degenerative diseases and cancer, acting as an antioxidant and by inhibition of mutagenesis. However, the scientific evidences of these actions are still controversial. Questions have been raised about where these properties take place, if in the gut before absorption or if they are due to a post-absorption systemic action. The purpose of this research was to study the chemical changes of chlorophyll during its passage through the gastrointestinal tract, the apparent absorption and the appearance of any chlorophyll derivative in blood. The study was carried out during 1 O days in twelve dogs (Canis familiaris) divided into 2 groups. The control group received a commercial diet attending their nutritional requirements, while the test group received the same diet to which 0.8% of freeze-dried spinach and 0.35% of chromium oxide (as a non-absorbable indicator) were added. Partial collection and analysis of excreta was carried out and apparent absorption was calculated. ln a second experiment, blood was collected at 0, 15, 30, 45, 60, 90, 120 and 150 min after the intake of the diet, which contained 10% freeze-dried spinach. Pigments in spinach, diet, excreta and blood were extracted with 80% acetone, isolated and quantified by HPLC. The results showed that pheophitinization was the predominant pathway. Only pheophytins a and b were found in excreta. Apparent absorption of chlorophyll ranged from 4 to 6%. However, it was not possible to detect the presence of chlorophyll or any of its metabolites in blood plasma. These findings suggest that eventual beneficial effects of chlorophyll may occur predominantly in the gut and in case that some uptake occurs, the molecule seems to be metabolized fast enough in order to prevent toxic photosynthetic activity related effects.
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Eugster, Manuel J. A. "Benchmark Experiments". Diss., lmu, 2011. http://nbn-resolving.de/urn:nbn:de:bvb:19-129904.
Testo completo
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Tano, Clara Tsugumi Nakamura. "Avaliação histológica do tecido adiposo da pele de ratas sob ação de cafeína e Cafeisilane® C". Universidade de São Paulo, 2003. http://www.teses.usp.br/teses/disponiveis/9/9139/tde-09042015-125901/.
Testo completoAbstract (sommario):
Hidrolipodistrofia ginóide é uma alteração genuína e loco-regional do panículo adiposo subcutâneo determinante do formato corporal característico da mulher. Várias substâncias ativas podem ser empregadas como anticelulíticos, sendo selecionado para esse trabalho a cafeína e o silício orgânico da cafeína (Cafeisilane® C). Foram desenvolvidas formulações cosméticas (9 emulsões empregando como base cera emulsionante não iônica e 3 géis utilizando polímero carboxivinílico e 1 gel a base de hidroxietilcelulose) contendo cafeína 4,0% p/p; cafeína e benzoato de sódio, ambos a 4,0% p/p e Cafeisilane® C 6,0% p/p e, as mesmas foram submetidas ao estudo de estabilidade acelerada nas seguintes condições: 4° C, ciclos alternados gela/degela (-10° C/45° C), 45° C, -10° C, 22° C e luz solar indireta. Das formulações avaliadas foram selecionadas uma emulsão não iônica e um gel de hidroxietilcelulose para o estudo \"in vivo\" em modelo animal, a fim de avaliar a ação lipolítica da cafeína e Cafeisilane® C. Após análise histológica do dorso depilado das ratas de linhagem Wistar, tanto a cafeína como o Cafeisilane® C apresentaram melhor resposta quando incorporados em emulsão não iônica, ocorrendo redução no diâmetro das células adiposas em 17% para a cafeína e 16% para o Cafeisilane® C. Nesta última preparação, também ocorreu redução de 32% no número de células adiposas. Da forma cosmética gel, apenas o que utilizou como base a hidroxietilcelulose com Cafeisilane® C promoveu redução de 26% no número de adipócitos quando comparado com o gel controle.Gynoid hydrolipodystrophy is a genuine and regional alteration of the hypodermis, a subcutaneous tissue that determines the characteristic format of the female\'s body. Several active substances can be added in anticellulite cosmetics and in this research there were selected caffeine and siloxanetriol alginate caffeine (Cafeisilane® C). There were developed different cosmetic formulations (9 emulsions with nonionic emulsifying wax, 3 gels with carboxyvinilic polymer and 1 gel with hydroxyethyl cellulose) employing caffeine 4,0% w/w; caffeine and sodium benzoate, both 4,0% w/w, and Cafeisilane® C 6,0% w/w. Formulations above were submitted to the stress testing: 4° C, alternate freeze/thaw cycles (-10° C/45° C), 45° C, -10° C, 22° C and indirect sunlight, as the conditions. We selected one nonionic emulsion and the hydroxyethyl cellulose gel for the in vivo study in animal model for the evaluation of the lypolitic activity of caffeine and Cafeisilane® C. After histological analysis of Wistar\'s depilated back (female rats), as much caffeine as Cafeisilane® C resulted better answers when incorporated in nonionic emulsion, with diameter reduction of the fatty cells in 17% for caffeine and 16% for Cafeisilane® C. Within the Cafeisilane® C emulsion, reduction of 32% in the number of fatty cells occurred. Only hydroxyethyl cellulose gel with Cafeisilane® C promoted the reduction of 26% in the adipocytes numbers, when compared with the control gel.
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Quan, Aaron. "Batch Sequencing Methods for Computer Experiments". The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1401462464.
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Leatherman, Erin Rae. "Optimal predictive designs for experiments that involve computer simulators". The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1376393067.
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Kiouranis, Neide Maria Michellan [UNESP]. "Experimentos mentais no ensino de ciências: implementação de uma sequência didática". Universidade Estadual Paulista (UNESP), 2009. http://hdl.handle.net/11449/102017.
Testo completoAbstract (sommario):
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kiouranis_nmm_dr_bauru.pdf: 28976036 bytes, checksum: 3a8492dd7821465a9e1d894cc6bdd088 (MD5)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Esta pesquisa é fruto do desenvolvimento de uma sequência didática sobre o comportamento das entidades físicas: partícula, onde e partícula-onda no Experimento da Supla Fenda, numa versão adaptada de Feynman e colaboradores e foi desenvolvida com estudantes de terceira série do ensino superior do curso de Química, disciplina Química Quântica, de uma universidade pública estadual. O objetivo geral do estudo foi discutir os fundamentos e práticas de experimentos mentais, tendo como parâmetro a utilização de diversas alternativas didáticas e seus desdobramentos para o ensino nas disciplinas científicas. A pesquisa de cunho qualitativo ancora-se nos fundamentos dos experimentos mentais e tem por base as teorias que visam promover a comunicação verbal e escrita dos conhecimentos científicos. O problema de pesquisa originou-se das dificuldades que os estudantes demonstravam em sala de aula para explicar e debater suas idéias, de maneira significativa, inteligível e dinâmica, quando estas exigiam deles o domínio da verbalização de conhecimentos científicos sobre o experimento da dupla fenda. Para interpretação e análise dos dados, utilizou-se a vertente interpretativa por meio de instrumentos e técnicas que permitem, principalmente, a descrição e interpretação de fatos e fenômenos, a recuperação de sentidos, tendo como base a investigação interpretativa do conjunto de materiais empíricos que se transformaram em textos. Os resultados revelam que os procedimentos didáticos utilizados são relevantes por possibilitarem a problematização, a discussão, o uso da imaginação e da linguagem verbal e escrita, pouco usuais em contextos de aulas de Química Quântica. Com relação aos textos, tanto aqueles transcritos das discussões e das falas dos estudantes quanto os que foram produzidos durante o desenvolvimento da pesquisa, por solicitação do professor...
This research is the result of the development of a didactic sequence on the behavior of physical entities: particle, wave and wave-particle in the Double-Slit Experiment, in an adapted version from Feynman and assistants, which was developed with university students from the third grade of the Chemistry course, in the discipline of Quantum Chemistry, at a Brazilian public state university. The study aimed to discuss the fundaments and practices of thought experiments by using several didactic alternatives and its unfoldings to the teaching of scientific disciplines. The research, of qualitative basis, is anchored to the fundaments of thought experiments grounded on theories aiming to promote verbal and written communication of scientific knowledge. The research problem focuses on the difficulties that the students show in the classroom in order to explain and discuss their ideas when theses require that they master verbalization of scientific knowledge on the double-slit experiment in a meaningful, significant and dynamic manner. To the purpose of data interpretation and analysis, we used the interpretative perspective by means of the methodological and theoretical. Results revealed that the didactic procedures used are relevant since they allow problematization, discussion, the use of imagination and of verbal and written language, quite rare in classroom contexts of Quantum Chemistry. Regarding the texts, both the ones transcribed during the discussions and the students' speeches and those produced during the development of the research, required by the teacher, deserve attention. The text productions were found considerably reduced, fragmented, lacking progression and continuity of ideas, and also lacking the interconnected sequence of the parts that constitute an articulated whole. By means of discourse analysis, we detected loss of the line of unity that assures its interpretability... (Complete abstract click electronic access below)
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Jhunjhunwala, Tanushree Jhunjhunwala. "Essays in Behavioral and Experimental Economics". The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu152388532104035.
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Souza, Ana Cristina de. "Avaliação das populações celulares e da atividade proliferativa de precursores hematopoéticos esplênicos de camundongos submetidos à desnutrição protéica". Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/9/9136/tde-10022015-164159/.
Testo completoAbstract (sommario):
A desnutrição altera o sistema imunológico, freqüentemente modificando a resposta do hospedeiro frente a patógenos e predispondo o indivíduo à infecções. Neste trabalho, utilizando ensaios clonogênicos e imunofenotipagem, avaliamos os efeitos da desnutrição protéica em precursores hematopoéticos esplênicos. Camundongos Swiss Webster, machos, com dois a três meses de idade, foram alimentados com ração contendo 4% e 20% de proteína constituindo os grupos desnutridos e controle, respectivamente. A fonte protéica das rações foi a caseína. Os animais foram mantidos em gaioleiros metabólicos, sob temperatura ambiente de 22° a 25°C e ciclo de luz de 12 horas. A desnutrição experimental foi induzida após período de adaptação às condições do gaioleiro metabólico. O consumo de ração, de água e a variação do peso corporal inicial, foram avaliados a cada 48 horas. Após a perda de 20-25% do peso corpóreo inicial, foram colhidas amostras sangüíneas para a verificação do perfil hematológico, determinação das concentrações séricas de proteínas e da albumina. As células esplênicas foram colhidas para a realização do esplenograma, dos ensaios clonogênicos e da imunofenotipagem, utilizando-se painel de anticorpos monoclonais. Para a obtenção de progenitores granulocíticos (CFC-GM), empregou-se a associação dos fatores de crescimento G-CSF (1ng) e GM-CSF (0,1ng). A obtenção de progenitores granulocíticos e eritróides (CFC-Mix) se deu pela associação dos fatores de crescimento IL-3 (1ng) e EPO (5UI). Os resultados obtidos indicaram redução significativa no grupo desnutrido, do consumo de ração e peso corpóreo, das concentrações séricas de proteínas totais e albumina, bem como do volume do hematócrito, concentração de hemoglobina e do número global de leucócitos. A celularidade esplênica também apresentou redução significativa no grupo desnutrido, quando comparada a do grupo controle. Nos ensaios clonogênicos, o grupo desnutrido apresentou menor formação de \"clusters\" e de colônias frente aos fatores de crescimento utilizados. Na imunofenotipagem, o mesmo grupo apresentou aumento na percentagem de células CD34+, bem como de precursores linfóides T, identificados por anti CD2 e anti CD5 e de precursores linfóides B, identificados por anti CD19 e anti CD22. Estes resultados sugerem que a desnutrição protéica induz, in vivo, a redução das células primitivas e bloqueio maturativo em células precursoras esplênicas. Os ensaios clonogênicos indicaram que as células de animais desnutridos não respondem adequadamente aos fatores de crescimento, sugerindo alterações em receptores e, ou processos transducionais e, ou transcricionais.Malnutrition usually affects the immune system, most of the times modifying the immunological response to pathogens, predisposing the individuals to infections. In this work the effect of protein malnutrition on splenic hematological precursors were investigated by clonogenic assays and immunephenotyping. Two months old male Swiss Webster mice were fed with chow containing 4% and 20% casein, respectively the deprived and the control groups. The animals were observed in metabolic cages, at 22-25° C and light-controlled during 12 hours. The experimental procedure was started after the animals were accustomed to the environment. The chow and water consumption as well as the weight were recorded every 48 hours. Soon after a 20-25% weight loss, blood samples were collected in order to determine hematological parameters, and serum protein and albumin. The splenic cells were collected and used to do the splenogram, clonogenic assays and immunephenotyping with monoclonal antibodies. Growth factors G-CSG (1 ng) and GM-CSF(0.1 ng) combination were employed to obtain the granulocytic progenitors CFC-GM. The growth factors IL-3 and EPO (5 UI) association were used to obtain the granulocytic and erythroid progenitors (CFC-Mix). The obtained data indicated significative reduction of weight, chow consumption, serum proteins, blood hematocrit, hemoglobin concentration and leucocytes in the deprived group. The deprived group splenic cellularity exhibited decrease in comparison to the control group as well. The clonogenic assays disclosed decreased formation of clusters and colonies at exposure to specific growth factors in the deprived group. In this group the immunephenotyping showed CD34+ cells increase, as well as linfoid T precursors, identified by anti CD2 and anti CD5, as well as linfoid B precursors, identified by anti CD19 and anti CD22. These data suggest that protein malnutrition leads, in vivo, to primitive cells reduction and progenitor cells maturative blocking. The clonogenic assays indicated that the hematopoietic cells from deprived animals did not respond to growth factors, suggesting that receptors, transduction and, or transcriptional modifications may have occurred.
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Sainudiin, R. "Machine Interval Experiments". Thesis, University of Canterbury. Mathematics and Statistics, 2005. http://hdl.handle.net/10092/2833.
Testo completoAbstract (sommario):
A statistical experiment is a mathematical object that provides a framework for statistical inference, including hypothesis testing and parameter estimation, from observations of an empirical phenomenon. When observations in the continuum
of real numbers are not empirically measurable to infinite precision and when conventional floating-point computations used in the inference procedure are not exact, the statistical experiment can become epistemologically invalid. The family of measures of the conventional statistical experiment indexed by a compact finite dimensional continuum is extended to the complete metric space of all compact subsets (of a certain form) of the index set. This is accomplished by the natural interval extension of the likelihood function. The extended experiment allows a statistical decision made with the aid of a computer to be equivalent to a numerical proof of its global optimality. Three open problems in computational statistics were solved using the extended experiment: (1) parametric bootstraps of likelihood ratio test statistics for finite mixture models, (2) rigorous maximum likelihood estimates of the branch lengths of a phylogenetic tree with a fixed topology or shape and (3) Monte Carlo sampling from a multi-modal target density with sharp peaks or witches’ hats.
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Larson, Richard Winston. "Portable controls experiments". Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/74445.
Testo completoAbstract (sommario):
Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2012.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 88).
Experiments for controls classes like MIT's 2.004 require large lab setups and expensive equipment such as oscilloscopes and function generators. We developed a series of controls experiments based on National Instruments' myDAQ platform. These experiments, which are small enough to fit on a single PCB board and weigh less than a pound, allow students to work on controls labs at their own pace wherever they please, increasing the ease of learning. We designed and prototyped a double integrator experiment and a DC motor experiment. We implemented the control software in NI LabView, and we have produced accompanying documentation. We will make the circuit layouts, controller software, and lab documentation available to the public through the NI myDAQ website. Other schools will be able to use our designs in their courses.
by Richard Winston Larson.
S.B.
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Pretorius, Werner. "Experiments in inhumanity". Master's thesis, University of Cape Town, 2008. http://hdl.handle.net/11427/10702.
Testo completoAbstract (sommario):
Includes abstract.Experiments in Inhumanity utilises for its setting the recognisable suburban backdrop of a mid to late nineties and early 21st century Cape Town and Pretoria. It focuses its attention around a specific white, middle class experience within pop-culture, making many references to music, television and film. In so doing it enters the debate as to how influential pop culture may be on teen behaviour, such as violence within relationships and peer groups. It throws elements like morose suburban existence, family dynamics and dysfunctional behaviour (specifically of a sexual nature) into the melting pot and attempts thereby to illustrate a fictional situation, which illuminates how youth culture might produce juvenile delinquency. It follows the lives of siblings Michael and Alison and gives a window into the formative years of these characters as they struggle to find and sustain meaningful relationships. The characters' problems stem from a sexually traumatic incident in childhood. The novel investigates how, faced with the same starting point, the two characters achieve vastly different outcomes. The novel uses German philosopher Friedrich Nietzsche's idea of Eternal Recurrence as a motif, suggesting a repetitive, cyclical experience in the lives of the characters. It supposes a finite set of events recurring over an infinite time span. It also experiments with narrative structure, breaking up a predictable - or expected - chronology while still attempting to retain a well-structured, suspenseful plot. The seemingly out-of-sync chronology has the purpose of reflecting the confusion inherent in the lives of the characters, as they attempt to reconstruct or extract meaning from a tortured existence.
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Suits, Julia Halyburton. "Experiments in sculpture". The Ohio State University, 1987. http://rave.ohiolink.edu/etdc/view?acc_num=osu1303326764.
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Perianayagam, Somasundaram. "Reproducing Software Experiments". Diss., The University of Arizona, 2011. http://hdl.handle.net/10150/145386.
Testo completoAbstract (sommario):
Computational science software experiments are hard to reproduce because external data sets could have changed, software used in the original experiment cannot be reconstructed, or the input parameters for an experiment may not be documented. We have developed a set of tools called Rex to aid in reproducing software experiments. They enable one to record an experiment and archive its apparatus, replay experiments, run new experiments on a recorded apparatus, and compare two recorded experiments. Rex can handle sequential, multiprocess, and multithreaded programs. It does not require any modification to applications or the operating system on which they execute. The implementation of the Rex tools is based on being able to trap and compare the system calls made by an experiment. This dissertation discusses the challenges in reproducing software experiments and describes Rex's design and implementation. It also evaluates the execution and space overhead of the Rex tools.
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FALCÃO, Larissa Catão Tenório. "Analysis of human-centric software engineering experiments: a systematic mapping study". Universidade Federal de Pernambuco, 2016. https://repositorio.ufpe.br/handle/123456789/17930.
Testo completoAbstract (sommario):
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Dissertacao - Larissa Falcao - Final - Correcoes Biblioteca - Entrega.pdf: 1172723 bytes, checksum: b0a57a917a5abab25c66870d353d906f (MD5)Made available in DSpace on 2016-09-28T12:40:17Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertacao - Larissa Falcao - Final - Correcoes Biblioteca - Entrega.pdf: 1172723 bytes, checksum: b0a57a917a5abab25c66870d353d906f (MD5) Previous issue date: 2016-02-18
CNPq
Software Engineering professionals need to have information about new support mechanisms to decide, not at random, what option is best adapting it needs. One way of obtaining this information is through empirical studies that make the mechanisms used to support the design and development of software, be evaluated in practice. Thus, scientific research through experiments and empirical studies are fundamental during the evaluation of any new technology to software development. In this context, researchers perform experiments to check their proposals under controlled conditions. Therefore, experiments are an important category of empirical studies and are the classical approach for identifying cause-effect relationships. The goal of this dissertation is qualitatively and quantitatively characterizes and analyze human-centric experiments in software engineering, published in three journals andthree conferences proceedings from 2003 to 2013. To reach this objective was performed a systematic mapping study that includes all full papers published at EASE, ESEM, ICSE, ESEJ, JSS, TSE. Based on manual searches in those important conferences and journals in Software Engineering, were analyzed 3671 papers. 244 primary studies were identified as relevant, reporting experiments. In these experiments, we obtained qualitative and quantified data about authors and institutions, subjects, tasks performed, environment, replication and threats to validity. From the analysis performed, this work conclude that despite guidelines exist now, there is a large gap in the report of the experiments. The main contribution of this work is to provide the reporting status of human-centric software engineering experiments and how this field has matured. This work also proposes a list of information that an experiment report expected to have.
Profissionais de engenharia de software precisam ter informações sobre os novos mecanismos de apoio, a fim de decidir sem ser ao acaso, qual é a melhor opção que se adapta ao que se precisa. Uma maneira de obter essas informações é através de estudos empíricos, que permitem que os mecanismos utilizados para apoiar a concepção e desenvolvimento de software sejam avaliados na prática. Assim, a pesquisa científica através de experimentos e estudos empíricos são de fundamental importância na avaliação de qualquer nova tecnologia para desenvolvimento de software. Pesquisadores realizam experimentos para verificar as suas propostas sob condições controladas. Portanto, os experimentos são uma categoria importante de estudos empíricos e são a abordagem clássica para identificar relações de causaefeito. O objetivo deste trabalho é caracterizar qualitativa e quantitativamente, e analisar experimentos centrados em humanos em engenharia de software, publicados em três jornais e três conferências de 2003 a 2013. Para atingir este objetivo foi realizado um estudo de mapeamento sistemático que inclui todos os artigos completos publicados no EASE, ESEM, ICSE, ESEJ, JSS, TSE. Com base em pesquisas manuais nessas importantes conferências e periódicos em Engenharia de Software, foram analisados 3671 artigos. 244 estudos primários foram identificados como relevantes, relatando experimentos. Nesses experimentos foram obtidos dados qualitativos e quantificados sobre autores e instituições, participantes, tarefas realizadas, o ambiente, replicação e ameaças à validade. A partir da análise realizada, este trabalho conclui que apesar dos guias existirem agora, há uma grande lacuna no relatório desses experimentos. A principal contribuição deste trabalho é fornecer o status dos relatórios de experimentos centrados em humanos em engenharia de software e como este campo amadureceu. Este trabalho também propõe uma lista de informações que um relatório de experimento deve ter.
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Bai, Xin. "Correction of the magnetic field values of E781 SELEX spectrometer system, using a sign correction approach". Virtual Press, 2001. http://liblink.bsu.edu/uhtbin/catkey/1217400.
Testo completoAbstract (sommario):
In this thesis, the current vs. magnetic field relationships for four magnets, M1, M2, M3, and Hyperon of FNAL Experiment E781 (the charm baryon study) havel,een studied on the basis of algorithms involving sign corrections pertaining to remedying incorrect FNAL EPICURE readout system's current and magnetic field values for E78 I's 4 magnets.After analyzing previous BSU personnel's work involving re-averaging of the current and magnetic field output values for E78 1, further research was carried out in this thesis activity regarding the correction of the algebraic signs of certain current and magnetic field values in the FNAL EPICURE read out values inputted into E781' data bank.Firstly, a code was developed to merge the four files of current and magnetic fields for the four magnets of E78 1, all into one file. Then, an algorithm for a sign correction program was developed in order to both sort the merged data and correct the current and magnetic field signautomatically.In order to obtain a better understanding of the effect of the incorrect sign for a magnet's current and magnetic field on analysis results, a statistical result was summarized. Finally, some conclusions were obtained.Department of Physics and Astronomy
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Zhang, Ying. "Online experimenter : an evaluation of experiments conducted under local and remote conditions". Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/5542.
Testo completoAbstract (sommario):
When conducting experiments, researchers traditionally work in a lab setting
where they have access to specialized equipment and can meet their subjects faceto-
face. This is definitely the way that traditional experiments in behavioral
research are carried out. However, with the growing need for recruiting
experiment participants from different social and cultural backgrounds, it may be
difficult to design a traditional lab experiment for the research. Moreover, highly
specialized lab equipment cannot always be easily accessed, and the costs of
commuting present financial constraints. We explored the necessity of co
presence in experimentation by evaluating a facility to determine whether
experiments conducted in a non co-present context would achieve the same
scientific outcomes as the ones conducted in a traditional lab context. The facility
that we used was designed to allow researchers’ access to a sophisticated lab for
the purpose of experimentation in educational research. There are two research
goals explored in this thesis: (1) to evaluate the relative efficacies of running an
experiment under co-present and non co-present conditions, and (2) to assess
whether the participants’ experience differs in the experimental process between
the co-present and non co-present condition.
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Valks, Pamela. "Bayesian decision theoretic approach to experimental design with application to usability experiments". Thesis, University of Sunderland, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.414851.
Testo completoAbstract (sommario):
This thesis looks at the practicality of applying a Bayesian Decision Theoretic approach to the design of HCI usability experiments. It looks at the particular issues involved in following the Bayesian experimental design framework of developing a stochastic model, eliciting priors and utility functions and choosing the option with the maximum expected utility. HeI usability testing may involve user and analyst experimentation and various courses of action may be employed using either one or both types of experiment. The thesis shows that HeI usability experiments can be represented diagrammatically by a decision tree so that courses of action and consequences can be shown in sequential order and consequently that decision theory can be applied to experimental design. A structure of three decisions is proposed for the user experiment where the design of the experiment is a decision within the larger decision of whether to launch or rewrite. A structure of a single decision is proposed for the analyst experiment. The thesis shows that stochastic models can be developed which give solutions using realistic priors and utility functions. For the user experiment the problem of a joint prior distribution for two dependent binomial parameters is overcome by developing a method using copula functions. For the analyst experiment a two factor capturerecapture model for the identification of potential HeI problems is developed. Two ways of representing the utility function, either in terms of monetary rewards only or as a bivariate utility function, are investigated. The thesis shows that for realistic utility functions both ways require numerical methods to calculate the expected utilities, but a bivariate utility function has computational and elicitation advantages. Hel usability experiments pose many questions including the following. Should a user experiment be performed is it better to launch or rewrite without performing an experiment? If a user experiment is performed what is the optimal number of subjects? After a user experiment is it better to launch or rewrite? What is the optimal number of analysts to take part in an experiment? How many problems are remaining in the system after an analyst experiment? This thesis shows how models currently described in the HCI literature can be generalised using a Bayesian Decision Theoretic approach and used to give answers to these questions.
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Wood, Nicole E. "Conducting Experiments: On the Connections Between Experimental Art Praxes and Performance Studies". OpenSIUC, 2015. https://opensiuc.lib.siu.edu/dissertations/1047.
Testo completoAbstract (sommario):
This dissertation explores experimentation--across experimental music, experimental theatre, and experimental film, in addition to the term's etymology, scientific usage, and colloquial deployment--in order to derive a deeper understanding of what we mean when we say an artwork is experimental, and how this term can help us understand current artistic praxes and products emerging from performance studies contexts. In this document, I advocate for the term experimental performance as both an umbrella term and as a specific genre name for the artistic activity of contemporary artists working between experimental theatre and performance art, often within performance studies contexts. Ultimately, citing the historical richness of experimental art and its long-standing relationship to the academy as evidence, I advocate for the further academic acknowledgement of experimental performance.
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Woldu, Essayas Gebrewahid, e Fareed Ahmed Jokhio. "Experiments with Vehicle Platooning". Thesis, Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-5621.
Testo completoAbstract (sommario):
This thesis is concerned with an experimental platform for studying cooperative driving and techniques for embedded systems programming. Cooperative driving systems use vehicle-to-vehicle and vehicle-to-infrastructure communication for safe, smooth and efficient transportation. Cooperative driving systems are considered as a promising solution for traffic situations such as blind crossings. For the thesis work we use a robotic vehicle known as PIE (Platform for Intelligent Embedded Systems) equipped with a wireless communication device, electrical motors and controlled via a SAM7-P256 development board. For the infrastructure side we use a SAM7-P256 development board equipped with nRF24l01. Vehicle to vehicle and base station to vehicle communication is established and different platooning scenarios are implemented. The scenarios are similar to platooning scenarios from the Grand Cooperative Driving Challenge GCDC1. The performance of the platoon control algorithm is measured in terms of throughput (a measure of string stability), smoothness and safety, where the safety requirements serve as pass/fail criteria.
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Kiesel, Nikolai. "Experiments on Multiphoton Entanglement". Diss., lmu, 2007. http://nbn-resolving.de/urn:nbn:de:bvb:19-77291.
Testo completo
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Häggqvist, Sören. "Thought experiments in philosophy". Doctoral thesis, Stockholms universitet, Filosofiska institutionen, 1996. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-81418.
Testo completo
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Tan, Joseph K. H. "Graphics : theories & experiments". Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/29304.
Testo completoAbstract (sommario):
The primary justification of this research lies in the current thinking among graphics theorists and Management Information Systems researchers that different forms of information representation facilitate different types of tasks, and that it is the task characteristics which essentially influence performance with a given information presentation.
Three experiments were designed to investigate hypotheses drawn from the literature testing the relative strengths and weaknesses of various graphical representations for answering a series of questions. Three forms of graph format were studied comprising bars, symbols, and lines. Time is the primary dependent variable of interest in this research. Accuracy is a secondary criterion. The tasks investigated involved the extraction of relationships among elementary classes of information depicted on various attribute components of time series data: (1) Dependent Variable (DV) component (namely, information on scale-values, level relationships, and trends); (2) Primary Independent Variable (PIV) component (namely, information on abscissa time period); and (3) Secondary Independent Variable (SIV) component (namely, information on dataset classification).
Experiment 1 tasks involved the extraction of the DV scale-value (QT), DV level relationship (Q2), and DV trend (Q3) based on specific time period information on the PIV component. Results indicated that lines took longest for Q1 when compared to bars and symbols. Conversely, experiment 2 tasks involved the extraction of time period information based on a specific DV scale-value (Q1), the DV level relationship between two points (Q2), or the DV trend among several points (Q3). No statistically significant time differences were found among the various graph formats. However, lines were less accurate to use than bars for answering Q1.
Experiment 3 tasks involved the extraction of dataset information from the SIV component based solely on a specific DV scale-value (Q1), the DV level relationship between two points (Q2), or the DV trend among several points (Q3). Results revealed that the time required for answering either Q2 or Q3 was longest with bars.
Together, these results strongly indicated that the degree of support provided by a particular graph format for a particular task is heavily dependent upon the matching of task characteristics with graph format characteristics. Having information related to either the answer or question anchored on the x-axis and/or y-axis was found to influence task performance with the different graph formats investigated. Also, information complexity of graphics was found to be a function of time periods and/or datasets. There was only partial evidence to suggest the influence of individual characteristics on performance.Business, Sauder School of
Graduate
32
Soest, Gijs van. "Experiments on random lasers". [S.l. : Amsterdam : s.n.] ; Universiteit van Amsterdam [Host], 2001. http://dare.uva.nl/document/59235.
Testo completo
33
Jelercic, David. "Experiments in annular combustors". Thesis, Imperial College London, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.251891.
Testo completo
34
Kelly, Stephen William. "Experiments in implicit learning". Thesis, University of Glasgow, 1997. http://theses.gla.ac.uk/4989/.
Testo completoAbstract (sommario):
This thesis examines two paradigms from the area of implicit learning in detail. The literature suggests that the invariance detection paradigm of McGeorge and Burton (1990) gives rise to unconscious knowledge held at a conceptual level with the decision process served by a 'nearest-neighbour' similarity mechanism. The experiments in this thesis suggest that several aspects of this task do indeed seem to agree with present conceptions of unconscious knowledge but no evidence could be found that this knowledge is held at a conceptual level or that specific similarity plays any role in this task. Instead the experiments in this thesis suggest that this task may be better understood in terms of an abstraction mechanism which acquires perceptual information. Using the invariance detection paradigm, this thesis examines the effect of two types of task which measure performance above an 'objective threshold' of awareness. Performance on each task was not the same, suggesting that one cannot assume all direct tests measure the same knowledge despite being similar in nature. In addition, the finding that only the more sensitive of the two tasks could elicit information in the invariance detection paradigm suggests that the knowledge is extremely difficult to elicit. This also is a property of implicit learning and points to the digit invariance task being mediated by unconscious mechanisms. The finding of robust invariance detection in laboratory tasks suggests that one might expect to find similar learning for real world invariance. No evidence for this could be found, which suggests that either implicit learning is a laboratory artefact or that real world invariance learning does not operate in the same way that laboratory experiments suggest. These results suggest that laboratory experiments are required which replicate conditions under which real world learning might occur.
35
Sanders, M. "Experiments in rotenoid biosynthesis". Thesis, University of Nottingham, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376182.
Testo completo
36
Howe, Ethan (Ethan Gabriel Grief). "Simulated pion photoproduction experiments". Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/32903.
Testo completoAbstract (sommario):
Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Physics, 2005.Includes bibliographical references (leaf 18).
Introduction: In this paper, I will be assessing the capabilities of the Neutral Meson Spectrometer (NMS) detector in a planned experiment at the High Intensity Gamma Source at Duke University. I will review the relevant theory and set out the importance of this experiment. I will describe the proposed apparatus and how I have modeled it in my simulation. I will explain the data we wish to draw from the experiment and present results as to how well I believe this setup will perform.
by Ethan Howe.
S.B.
37
Skelley, James P. (James Paul). "Experiments in expression recognition". Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/37063.
Testo completoAbstract (sommario):
Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2005.Includes bibliographical references (p. 39-41).
Despite the significant effort devoted to methods for expression recognition, suitable training and test databases designed explicitly for expression research have been largely neglected. Additionally, possible techniques for expression recognition within an Man-Machine-Interface (MMI) domain are numerous, but it remains unclear what methods are most effective for expression recognition. In response, this thesis describes the means by which an appropriate expression database has been generated and then enumerates the results of five different recognition methods as applied to that database. An analysis of the results of these experiments is given, and conclusions for future research based upon these results is put forth.
by James P. Skelley.
M.Eng.
38
Banzaert, Amy 1976. "Experiments in service learning". Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/42312.
Testo completoAbstract (sommario):
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2006.Includes bibliographical references (p. 82-86).
Service learning, an educational method that involves the application of academic work to projects that benefit under-served communities, was explored in two complementary forms. First, the development of an alternative form of charcoal made from sugarcane agricultural waste is discussed, including product and process characterization and improvement. The motivation for the project is to establish an alternative cooking fuel that is less detrimental than existing options based on three criteria: health risks, environmental impact, and affordability. A method for improving the speed and safety of a critical process step is presented, and initial test findings demonstrate that the product generally matches the cooking parameters of the benchmark, the wood charcoal that this project seeks to replace. Second, the introduction of service learning pedagogy into three core mechanical engineering classes at MIT - 2.002 Mechanics and Materials II, 2.006 Thermo-Fluids Engineering II, and 2.009 Product Engineering Processes - is explored. Curricular materials, service projects, and assessment methods were developed and implemented. Based on initial research, the pedagogy is effective when integrated into the class well, meaning a project was chosen that was academically rigorous and matched both the curricular goals of the class and the needs of the community partner. In addition, positive social, career-oriented, and cognitive outcomes for students are evident, particularly for women and minority students. Use of service learning in 2.009 is also explored over four years, and positive results from interviews studying the interest in service learning by MIT mechanical engineering faculty are presented.
by Amy Banzaert.
S.M.
39
Fong, Nathan Minsheng. "Field experiments in retailing". Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/68959.
Testo completoAbstract (sommario):
Thesis (Ph. D.)--Massachusetts Institute of Technology, Sloan School of Management, 2011.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 75-81).
This dissertation consists of two essays on tactical issues in retailing. The first essay compares the price sensitivity of private label and national brand products. A large-scale field experiment shows that private label demand is less price sensitive than national brand demand. The estimates from the experimental study are then compared with estimates using the same retailer's transaction history. This allows the evaluation of several methods for controlling for the endogeneity of prices in non-experimental studies. Measuring price sensitivity in the historical data without accounting for endogeneity performs poorly. Instrumental variables estimates with commodity prices as instruments and regression discontinuity estimates also differ from the experimental benchmark. However, estimates using wholesale prices as an instrument closely replicate the experimental estimates. These findings indicate that the wholesale price is an effective instrument for retail price. The second essay shows how targeted offers can affect customer search activity. It has become common practice for retailers to personalize direct marketing offers based on customer transaction histories. Targeted email offers featuring products similar to a customer's previous purchases generate higher response rates, but also have the potential to affect customer search behavior. A closely matched offer may encourage a customer to start the search process, leading to increased search activity. Alternatively, providing customers with closely matched offers may weaken their incentives to search beyond the targeted items. In a field experiment using email offers sent by an online wine retailer, targeted offers result in less search activity on the retailer's website. In a second study, transaction data from an online ticket exchange shows that, after receiving targeted offers, customers are less likely to broaden their purchasing to new genres. These findings indicate that targeted offers carry a hidden cost: a decrease in customer exploration and discovery.
by Nathan Minsheng Fong.
Ph.D.
40
Turaev, Michael. "Numerical Experiments in Billiards". Thesis, Uppsala universitet, Institutionen för fysik och astronomi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-279462.
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K/Bidy, Gilles. "XML META-DATA EXPERIMENTS". International Foundation for Telemetering, 2007. http://hdl.handle.net/10150/604549.
Testo completoAbstract (sommario):
ITC/USA 2007 Conference Proceedings / The Forty-Third Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2007 / Riviera Hotel & Convention Center, Las Vegas, NevadaAs part of the technology upgrades driven by the iNet initiative, there is a need to establish a meta-data standard to describe configuration information for the system under test. The technology identified for such a standard is XML and XSD schemas. This paper presents findings from various experiments to import and export existing telemetry configuration information to XML based on the new Meta-data model. In addition, this paper will discuss the possible conversions to and from the existing IRIG TMATS standard.
42
Freixas, Angel Luis. "Surface plasmon resonance experiments". FIU Digital Commons, 2007. http://digitalcommons.fiu.edu/etd/3417.
Testo completoAbstract (sommario):
In this study, a Surface Plasmon Resonance (SPR) optical sensor, based on Kretschmann configuration, was designed and constructed. SPR is a useful tool for obtaining quantitative kinetic and affinity information on biomolecular interactions.
The resolution and the sensitivity of our homemade SPR system was determined and optimized by using thiols and sucrose solutions. The data were normalized and processed to increase the resolution of the system. The sensograms were obtained and the kinetic constants were analyzed. The sensogram of the thiols solutions illustrated the process of association of the thiols on gold surface. The sensogram of the sucrose solutions shown, that the sucrose doesn't have association on gold surface.
43
Koutra, Vasiliki. "Designing experiments on networks". Thesis, University of Southampton, 2017. https://eprints.soton.ac.uk/416580/.
Testo completoAbstract (sommario):
Designing experiments on networks challenges an assumption common in classical experimental designs, which is that the response observed on a unit is unaffected by treatments applied to other units. This assumption is referred to as `non-interference'. This thesis aims at improving the design efficiency and validity of networked experiments by relaxing the non-interference assumption, where efficiency stands for low variance of the estimated quantities (precision) and validity for unbiased quantities (accuracy). We develop flexible and effective methods for designing experiments on networks (with a special focus on social networks) by combining the well-established methodology of optimal design theory with the most relevant features of network theory. We provide evidence that conventional designs such as randomised designs are inefficient compared to a systematic approach that accounts for the connectivity structure that underlies the experimental units. We investigate the impact of the network structure on the effciency and validity of the experimental design. There is evidence that the experimental design is determined by the small-scale properties of networks. We also develop an algorithmic approach for finding efficient designs by utilising the network symmetry as defined by the automorphism group of the underlying graph. This approach reduces considerably the search time for finding a good design in moderate-sized networks. It works by decomposing the network into symmetric and asymmetric subgraphs and consequently decomposing the design problem into simpler problems on these subgraphs. Moreover, we suggest a framework for finding optimal block designs, while taking into account the interrelations of groups of units within a network. In doing so, the units are initially divided into blocks, using spectral clustering techniques and the concept of modularity, prior to assigning the treatments. We study how the structural properties of the network communities affect the optimal experimental design and its properties. We also make a transition from experiments on social networks to experiments in agriculture showing the diversity of applications this research can address. In particular, we obtain optimal designs with two blocking factors while handling different definitions of neighbour structures related to either the distance among plots or the farmer operations. Throughout this thesis, several optimal designs on networks are obtained using a simple exchange algorithm, which is implemented in the R programming language.
44
Wotschka, Marco. "Experiments in Compressing Wikipedia". Ohio University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1376909207.
Testo completo
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Kim, Michael 1973. "Experiments on powder metals". Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/47843.
Testo completoAbstract (sommario):
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1998.Includes bibliographical references (leaves 138-142).
This thesis describes an experimental program aimed at the development of elastic-plastic constitutive relations for cold compaction of ANCOR MH-100 iron powder. A systematic experimental program consisting of triaxial compression, torsion ring shear, uniaxial strain compression, and simple compression test systems has been conducted to investigate the room temperature deformation response of powders ranging from a relative density of n = 0.4 - 0.9. A torsion ring shear apparatus has been designed and fabricated to investigate the frictional behavior of iron powder. The torsion ring shear apparatus is also used to examine the important interface frictional behavior between the powder compact and confinement dies.
by Michael Kim.
S.M.
46
Raponi, Damiano. "Trends in virtuality: experiments". Doctoral thesis, Università Politecnica delle Marche, 2016. http://hdl.handle.net/11566/243122.
Testo completoAbstract (sommario):
Negli ultimi anni la ricerca si sta concentrando nello sviluppo di innovative soluzioni per la progettazione orientate alla riduzione dei tempi di sviluppo, dei costi e l’incremento della qualità permettendo alle aziende di ridurre il time-to-market. Tra le soluzioni più rilevanti, le tecnologie AR/MR/VR permettono di realizzare prototipi virtuali in alta fedeltà che possono essere utilizzati per svolgere test con utenti reali. Spesso però le aziende rivedono le loro tecniche di prototipazione in base al prodotto che stanno sviluppando, non ottimizzando così i costi di sviluppo e non prendendo in considerazione le caratteristiche psicofisiche dell’utente reale.
Il lavoro svolto in questa tesi si concentra quindi sulla definizione di un appropriato framework integrato con i tradizionali processi di progettazione ed in grado di supportare le scelte dei progettisti nello sviluppo di prototipi virtuali in alta fedeltà al fine di sperimentare in contesti reali le soluzioni progettuali adottate.
Per raggiungere questo obbiettivo è stata creata una metodologia basata su un approccio UCD in accordo al quale il cliente viene coinvolto in tutte le fasi del metodo. Al fine di validare questa metodologia sono stati implementati una serie di strumenti di VP. Inoltre, i risultati dell’applicazione del metodo proposto con gli strumenti di VP implementati hanno permesso di sviluppare un sistema di VR interattivo e riconfigurabile adatto ad attrezzare laboratori per far vivere all’utente una User Experience completa.
La ricerca svolta è stata applicata a tre casi studio riguardanti lo studio di innovative interfacce utenti per vari contesti d’uso: a) una piattaforma web-based in grado di supportare il processo contract residenziale, b) un’innovativa soluzione per il monitoraggio dei parametri fisiologici di un utente e la creazione di percorsi benessere personalizzati, c) una interfaccia utente applicata ad una doccia ad elevata usabilità per persone anziane e con difficoltà visive.In the last years, research is focusing on the development of innovative design solutions aimed at reducing development time, costs and increase the quality enabling the companies to reduce the time-to-market. Among the most relevant solutions, the AR/MR/VR technologies allow to realize High-Fidelity virtual prototypes that can be used to carry out tests with real users. Nevertheless, the companies review their prototyping techniques according to the product that are developing, not optimizing the development costs and not taking into account the psychophysical characteristics of the real user. The work presented in this thesis is therefore focused on the definition of a structured framework integrated in the traditional design process and able to support the designers choices for the development of High-Fidelity virtual prototypes in order to experiment the adopted design solution in real context. In order to achieve this goal a methodology is defined. It is based on a User-Centered Design approach according to which the customer is involved in all steps. With the purpose to validate the proposed methodology a set of VP tools are implemented. In addition, the results from the methodology application with the implemented VP tools allow to develop an interactive and reconfigurable Virtual Reality system suitable to equip a laboratory in order to create a complete Virtual User Experience. The overall framework is applied to three real industrial case studies. All concern the study of innovative User Interfaces for various contexts of use: a) a web-based platform to properly support contract furniture, b) an innovative solution to monitor the physiological parameters of a user and therefore to create customized wellness routes, c) a User Interface applied to a shower with high usability for elderly and visual impaired people.
47
Musau, Andrew. "Game Experiments with Communication". Doctoral thesis, Università degli studi di Trento, 2015. https://hdl.handle.net/11572/369111.
Testo completoAbstract (sommario):
Economic experiments allow the investigator to achieve a controlled variation of some particular variable of interest, holding constant other background conditions. However, as it relates to communication, such a controlled variation may not be straightforward to achieve. We critically evaluate the design and implementation of game experiments in economics, and provide a review of the literature focusing mainly on bargaining and trust games (Chapter 1). Following some established results of anticipated communication in the dictator game, we investigate whether strategic considerations crowd out anticipatory effects of communication in the ultimatum game (Chapter 2). Finally, we identify and implement an experimental design that examines the role of first-mover anticipated communication on the inter-player strategic power dynamics that exist in a symmetric simultaneous move prisoners' dilemma and a sequential move investment game (Chapter 3).
48
Musau, Andrew. "Game Experiments with Communication". Doctoral thesis, University of Trento, 2015. http://eprints-phd.biblio.unitn.it/1620/1/Musau_Thesis.pdf.
Testo completoAbstract (sommario):
Economic experiments allow the investigator to achieve a controlled variation of some particular variable of interest, holding constant other background conditions. However, as it relates to communication, such a controlled variation may not be straightforward to achieve. We critically evaluate the design and implementation of game experiments in economics, and provide a review of the literature focusing mainly on bargaining and trust games (Chapter 1). Following some established results of anticipated communication in the dictator game, we investigate whether strategic considerations crowd out anticipatory effects of communication in the ultimatum game (Chapter 2). Finally, we identify and implement an experimental design that examines the role of first-mover anticipated communication on the inter-player strategic power dynamics that exist in a symmetric simultaneous move prisoners' dilemma and a sequential move investment game (Chapter 3).
49
Sullivan, Peter C. "Studies on the internalization and intracellular transport of horseradish peroxidase in Chinese hamster ovary cells". Diss., Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/49910.
Testo completoAbstract (sommario):
Soluble horseradish peroxidase (HRP) is internalized by Chinese hamster ovary cells, a cell line of fibroblastic origin (Adams et al., 1982). We have confirmed this result by showing no inhibition of uptake in the presence of divalent cation chelators (EGTA Mg or EDTA), excess (19 mg/ml) yeast mannan (an inhibitor of uptake through a mannose/N-acetylglucosamine receptor) or using periodate treated HRP. Periodate treatment destroys the ring structure of sugars on HRP which have hydroxyl groups on adjacent ring carbons, eliminating sugar mediated uptake of HRP. Once internalized, HRP is found in endocytic vesicles which by HRP-cytochemical staining, show deposits which rim the luminal face of vesicle membrane. Once HRP is in lysosomes, cytochemical deposits are luminal. To test if HRP is actually associated with vesicle membrane, a hypotonic lysis assay was used. Postnuclear supernatants (PNS) from cells pulse labeled with HRP were lysed and the percent of HRP sedimenting with a high speed membrane fraction was used as a measure of membrane association. After a pulse, >60% of the total HRP internalized was pelletable. Hypotonic lysis of a PNS at different pH and temperature showed no significant difference in "pelletability" from 4℃ to 37℃ at neutral pH and only a slight decrease in "pelletability" with increased temperature (4℃ to 37℃) at pH M.6. Binding of HRP in a membrane preparation was pH and temperature stable. Uptake of native HRP in the presence of yeast mannan (19 mg/ml) or using periodate treated HRP also had little effect on "pelletability", suggesting the absence of sugar specific binding in endocytic vesicles. Using the hypotonic lysis assay of a PNS after different chase times, HRP dissociation from membrane was observed over a 30 minute chase period. Internalized HRP in the presence of yeast mannan (19 mg/ml), intravesicular pH elevators HEPES (40 mM) or monensin (10 μM), or substances which should deplete cellular ATP NaF/KCN (2 mM /1 mM), showed no inhibition of dissociation kinetics. A chase at 17℃ inhibited dissociation of HRP over the entire 30 minute period. This HRP binding site(s) appears unique to endocytic vesicles.
A minimum of four steps in transport have been identified based on their sensitivity to inhibitors. HRP transport, identified by Percoll density gradient fractionation, was inhibited at 17°C and was sensitive to pH elevators (NH₄Cl, monensin, HEPES) and ATP depletion (NaF/KCN). Inhibition of transport appeared to be independent of HRP dissociation except at early temperature sensitive step(s). These results suggest that transport inhibition may be due to an effect on a) inhibition of membrane dissociation (early step(s)) and alteration of membrane fluidity (later steps) by reduced temperature and b) transmembrane events by pH elevators and ATP depletion.Ph. D.
incomplete_metadata
50
Rode, Edward James. "Rhodium-zeolite hydroformylation of propylene". Diss., Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/71252.
Testo completoAbstract (sommario):
The purpose of this research was to characterize the rhodium exchanged NaX and NaY zeolites as propylene hydroformylation catalysts. Catalytic activity was measured in a differential bed reactor. Flow in situ infrared spectroscopy was used to probe the coordination chemistry of the zeolite modified rhodium carbonyls.
The catalytic activity of rhodium zeolites at atmospheric pressure and between 100-150ºC was measured. The rate of n-butyraldehyde production was approximately 5x10⁻³ moles/g-
Rh hr at 150°C. Regioselectivity was dependent upon pretreatment. Precarbonylation with carbon monoxide, drying with air, and heating with N₂ prior to hydroformylation conditions produced a straight to branched isomer ratio (n/i) of 1.9-2.3. Partial reduction with 10% H₂ in N₂ at 127°C lowered n/i to 1.3. Hydrogenation to propane was 3-10 times faster than the hydroformylation rate at 150°C.
Catalytic activity was sensitive to cation exchange conditions. Rhodium form, pH, temperature, and salt concentration altered catalyst behavior. Only RhCl₃•3H₂O preparations on NaY zeolite produced above 80ºC, a pH above 4, and a salt concentration of 0.1N NaCl were required in order to produce an active hydroformylation catalyst. Ammine complexes did not activate under any circumstances.
It was found that the degree of hydration controlled the formation of rhodium carbonyls. On NaY, the hydrated rhodium zeolite reacted with CO at 120ºC to form Rh₆(CO)₁₆. By drying the zeolite in air at 190ºC, two rhodium dicarbonyls, Rh(CO)₂(Oz)₂-NaY and Rh(CO)₂(Oz)(H₂O)-NaY, were formed. The rhodium carbonyls were reacted with n-hexyl diphenylphosphine to determine rhodium locations. Rh(CO)₂(Oz)₂-NaY was located at the surface while the other two species were located within the zeolite cages. One dicarbonyl species, Rh(CO)₂(Oz)₂-NaX, was observed on NaX. It was determined by reactions with phosphines that this species resides in the zeolite cages.
Reaction intermediates identified by FTIR under hydroformylation conditions suggested that the heterogeneous catalyst proceeds through a mechanism similar to that occurring in solution. Heterogeneous reaction orders also agreed with those reported for homogeneous hydroformylations.
Addition of dimethylphenylphosphine (DMP) to the rhodium zeolites significantly increased regioselectivity. Rates were slightly less than those from the unmodified rhodium carbonyls. However, the phosphine modified rhodium zeolites deactivated within 16 hours. Continuous exposure to DMP decreased the rate of deactivation.Ph. D.