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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
291

Controle termohigrométrico microambiental para roedores de laboratório através da tecnologia termoelétrica: montagem, avaliação de desempenho do equipamento e teste de climatização em ratos (Rattus norvegicus) / Microenvironmental thermohygrometric control for laboratory rodents by means of thermoelectric technology: assembly, performance evaluation of equipment and acclimation in rats (Rattus norvegicus)

Alexandre Martinewski 05 October 2007 (has links)
Um condicionador de ar para biotérios foi montado com módulos termoelétricos de efeito Peltier. Para troca térmica, foram testados: 1. dissipação externa a ar, com &delta;t de 14°C, rendimento de 16,46%, consumo de 1212 W/h e, 2. dissipação externa água, com &delta;t de 21°C, rendimento de 46,02%, consumo de 524 W/h. A simulação matemática de operação, com mistura de ar não condicionado, mostrou que o sistema pode servir, na dissipação a ar, a aproximadamente 91 microisoladores padrão rato e a aproximadamente 137, na dissipação a água. Quando comparado com um sistema de compressão de freon, o termoelétrico mostrou economia de 26% na implantação e 38% no consumo elétrico por BTU gerado. O sistema termoelétrico mostrou ainda, precisão de &plusmn; 0,1°C, nas temperaturas experimentais, o que é impossível num sistema de freon. Para os testes em animais foram empregados Ratos wistar, mantidos individualmente, em gaiolas metabólicas de arame, sem abrigo, em sistema microambiental, sob fluxo direto de ar a 0,6 m/s, nas temperaturas de 22°, 24°, 26°, 28° e 30°C (E I, E II, E III, E IV e E V). A ingestão de ração e o ganho de peso foram comparados ao final de 5 dias (ANOVA; Tukey-Kramer). No total, 7 grupos de 15 animais cada foram comparados. Para a faixa de 22°C foram utilizados 3 grupos, sendo um grupo experimental e dois grupos controle (CI e C II). Um deles foi mantido em condições ambientais semelhantes a biotérios convencionais sob ventilação geral diluidora (VGD) - C I. O outro grupo controle (C II) foi mantido no interior do equipamento de ventilação microambiental, porém, sem o direcionamento de ar, simulando a VGD. Os resultados obtidos demonstraram claramente que animais mantidos sob ventilação microambiental direta a 26°, 28° e 30° (E III, E IV e E V) apresentaram o mesmo ganho de massa corpórea que animais do grupo C I (22 &plusmn; 2°C). Os grupos E I e E II apresentaram menor ganho de massa corpórea quando comparados a C I (p<0,001 em ambas comparações). O ganho de peso de todos os grupos experimentais apresentou diferença estatística, quando comparado ao C II, exceto o grupo E V que obteve índice de ganho de peso equivalente a C II. A ingestão de ração de todos os grupos se manteve praticamente constante. O grupo E V apresentou uma redução na ingestão de ração quando comparado aos grupos C I, E I e E II (p<0,01; p<0,01; p<0,001 respectivamente). O grupo E III ingeriu menos ração que os grupos C I (p<0,05) e E II (p<0,05). / An air-conditioner for animal facility was assembled with Peltier effect thermoelectric modules. For external exchanger, had been tested: 1. external air dissipation: &delta;t = 14°C; 16,46% of efficiency; 1212 W/h of power consumption and, 2. external water dissipation: &delta;t = 21°C; 46,02% of efficiency; 524 W/h of power consumption. A mathematical simulation of operation, with not conditional air mixture, showed that the system can supply, with air dissipation, to &asymp; 91 microisolator rat cages and to &asymp; 137, with water dissipation. When compared with a freon system, the thermoelectric system shows economy of 26% in implantation and 38% in the electric consumption by generated BTU. The thermoelectric system showed too, a precision of ± 0,1°C, at experimental temperatures, what is impossible in a freon system. For animal tests, Wistar rats had been kept individually, in metabolic wire cages, without shelter, in microenvironmental system, under direct air flow at 0,6 m/s, under temperatures of 22°, 24°, 26°, 28° and 30° C (E I, E II, E III, E IV and E V). The food ingestion and the weight gain had been compared in the end of 5 days (ANOVA; Tukey-Kramer). In the total, 7 groups, 15 animals each, had been compared. For the 22°C temperature, had been used 3 groups, one experimental and two controls (C I e C II). One of them was kept in similar ambient of conventional laboratory animal rooms conditions (general diluitory ventilation, GDV) - C I. The other control group (C II) was kept in the interior of the equipment of microenvironmental ventilation, however, without the direct air flow, simulating the GDV. The gotten results demonstrate clearly that animal kept under direct microenvironmental ventilation at 26°, 28° and 30°C (E III, E IV and E V) have the same gain of corporal mass that C I group (22 &plusmn; 2°C). The E I and E II had less corporal mass gain when compared to C I (p<0,001 for the two comparisons). The weight gain for all the experimental groups, when compared to C II, presents statistical differences, except E V group, that was equal to C II. The food ingestion of all the groups was constant. The E V group presented a reduction in the food ingestion when compared with the groups C I , E I and E II (p<0,01; p<0,01; p<0,001 respectively). The E III group ingested less ration than C I (p<0,05) and E II (p<0,05) groups.
292

Coordenação modular: acepções contemporâneas / Modular coordination: contemporary acceptations

Marina Rosa Crespo 23 May 2017 (has links)
A coordenação modular é um sistema para ordenação relativa de dimensões, espaços e componentes construtivos. Sua aplicação tem manifestações remotas por princípios que controlam a composição e fixam escalas convenientes para as partes e o todo, todavia foi a produção seriada industrial que determinou o papel que a disciplina teria no século XX. No Brasil, seu desenvolvimento aconteceu entre as décadas de 1950 e 1970, quando foi determinada a formatação fundamental da disciplina. Identifica-se a partir da década de 1980 um intervalo nas discussões específicas que durou até a virada do século, quando foi recuperado o interesse pela área. É consenso entre os autores que ainda não houve no Brasil sucesso na implantação de modelos abrangentes da coordenação modular, mas faltam análises atualizadas. O objetivo da dissertação - examinar o desenvolvimento da disciplina no Brasil após 1986 - está fundamentado em indícios de que as discussões recentes não se aprofundam em temas atuais e de que há um enfraquecimento de uma visão integrada do problema. As principais conclusões indicam que o desenvolvimento da construção civil vem sendo acompanhado do afastamento da arquitetura de etapas da produção, o que afeta o exercício da coordenação modular e que o programa habitacional e as ações políticas de financiamento foram determinantes para a retomada das pesquisas. Entretanto, há ecos dos modelos estabelecidos pelo setor privado, com ênfase à racionalização e à aplicação de componentes industriais. Diante disso, destaca-se que a coordenação modular, como campo da coordenação dimensional, está ligada às necessidades humanas. / Modular coordination is a system for relative ordering of dimensions, spaces, and building components. Its application presents remote manifestations through principles that control the design and set suitable scales for the parts and the whole. Nevertheless, the industrial mass production defined the role that the subject would play during the 20th century. In Brazil, its development took place between the 1960s and the 1970s; period that several authors consider decisive in what regards the subject\'s fundamental formatting. From the 1980s on, the specific debates about the matter went through a gap that lasted until the turn of the century when the interest in the field resurfaced. It is consensual among authors that Brazil still has not been successful to implement comprehensive modular coordination standards, but there is a lack of up-to-date analysis as well. The objective of the dissertation - to examine the discipline\'s development in Brazil after 1986 - is based on indications that recent discussions are leaving aside current issues and that there is a weakening of an integrated view of the matter. The main conclusions indicate that a dissociation between architecture and construction has accompanied the building industry\'s development, which affects the application of modular coordination. Moreover, the housing program and the research funding were decisive for the resumption of the field; nonetheless, there are echoes from the models established by the private sector, with emphasis on the rationalization and application of industrial components. In this context, it should be noted that modular coordination, as a field of dimensional coordination, is linked to human needs.
293

Reciclagem de painéis fotovoltaicos e recuperação de metais. / Recycling of photovoltaic modules and metals recovery.

Prado, Pedro Forastieri de Almeida 01 November 2018 (has links)
Com a expansão do emprego de módulos fotovoltaicos para geração energética, surge o desafio do descarte adequado desse resíduo de equipamento eletroeletrônico. Através da elaboração de um processo multietapas, esse desafio torna-se possível de ser abordado. O presente estudo possui o objetivo de recuperar os materiais presentes nos módulos fotovoltaicos de silício cristalino e de silício amorfo. Diversas técnicas de caracterização física e química foram empregadas para determinar-se composição dos módulos fotovoltaicos e consequentemente o fluxo de processos necessários para recuperação dos materiais identificados. Foi identificado que o módulo de silício cristalino possuía no semicondutor alguns metais como prata (na concentração de 0,063% em massa do módulo) e silício, e na fase polimérica polidimetilsiloxano como encapsulante e PET como backsheet. A separação e recuperação dos polímeros foi realizada através do uso da teoria de dissolução de solventes de Hildebrand, abordando aspectos termodinâmicos e cinéticos. A separação ocorreu em 24h a 860rpm mergulhando-se os módulos em isopropanol, podendo ocorrer separação em até 6h a 860rpm utilizando-se tetrahidrofurano. A lixiviação da prata a partir do semicondutor foi possível com ácido sulfúrico 4mol.L-1, 95°C, sob adição de 6mL de peróxido de hidrogênio a cada 15min, alcançando-se 100% de lixiviação em 2h. Alterando-se a temperatura para 30°C a lixiviação foi completa apenas em 6h de experimento Precipitou-se a prata em solução na forma de cloreto de prata com adição de cloreto de sódio. O módulo de silício amorfo continha EVA na fração polimérica e silício, germânio, prata, estanho e índio (concentração 0,34g/m2 do módulo) na fração metálica, observados tanto por micrografias quanto por análise química quantitativa. A calcinação a 400°C permitiu a remoção do EVA e liberação dos contatos de prata. A lixiviação de índio foi de 100% para uma solução 1mol.L-1 de ácido fosfórico a 75°C, sob 800rpm de agitação e relação sólido-líquido 1g.10mL-1 em 1h. / As the photovoltaic module market grows, an increasingly challenging scenario arises for solar modules end of life management. Such a scenario can be tackled through a process comprising multiple steps. This study has the objective to recover materials present in photovoltaic modules of crystalline silicon and amorphous silicon. Several characterization techniques (physical and chemical) were employed to determine the composition of the modules and thus the process flow needed to recover the identified materials. Along the process, it was noticed that the crystalline silicon module had in its semiconductor metals such as silver (in concentration of at least 0,063% in weight of module) and silicon. Also polydimethylsiloxane was identified as encapsulant and polyethylene therephtalate as backsheet. A separation and recovery of these materials was possible using the theory of solvent dissolution of Hildebrand, comprising thermodynamics and kinetics. The separation occurred in 24h at 860rpm, rising the modules in isopropyl alcohol and potentially reaching 6h at 860rpm when rising them in tetrahydrofuran. The silver leaching from the semiconductor phase was possible in sulphuric acid 4 mol.L-1, 95°C, under addition of 6mL of hydrogen peroxide every 15min, reaching 100% silver leached in 2h. Shifting the temperature to 30°C, the leaching would occur completely only after 6h of experiment. The silver was precipitated as a chloride from the solution by addition of sodium chloride. The amorphous silicon module showed that EVA was present in the polymeric phase and silicon, germanium, silver, tin and indium (the last one at concentration of 0,34g/m2 in area of the module) in the metallic phase, observed on the micrographies and chemical analyses. Calcination was performed at 400°C, removing the EVA and freeing the silver contacts. Indium was 100% leached with a 1mol.L-1 phosphoric acid solution at 75°C, under 800rpm and solid-liquid ratio of 1g.10mL-1 in 1h.
294

Optimization of Back Reflectors for Bifacial Photovoltaic Modules

January 2019 (has links)
abstract: Demand for green energy alternatives to provide stable and reliable energy solutions has increased over the years which has led to the rapid expansion of global markets in renewable energy sources such as solar photovoltaic (PV) technology. Newest amongst these technologies is the Bifacial PV modules, which harvests incident radiation from both sides of the module. The overall power generation can be significantly increased by using these bifacial modules. The purpose of this research is to investigate and maximize the effect of back reflectors, designed to increase the efficiency of the module by utilizing the intercell light passing through the module to increase the incident irradiance, on the energy output using different profiles placed at varied distances from the plane of the array (POA). The optimum reflector profile and displacement of the reflector from the module are determined experimentally. Theoretically, a 60-cell bifacial module can produce 26% additional energy in comparison to a 48-cell bifacial module due to the 12 excess cells found in the 60-cell module. It was determined that bifacial modules have the capacity to produce additional energy when optimized back reflectors are utilized. The inverted U reflector produced higher energy gain when placed at farther distances from the module, indicating direct dependent proportionality between the placement distance of the reflector from the module and the output energy gain. It performed the best out of all current construction geometries with reflective coatings, generating more than half of the additional energy produced by a densely-spaced 60-cell benchmark module compared to a sparsely-spaced 48-cell reference module.ii A gain of 11 and 14% was recorded on cloudy and sunny days respectively for the inverted U reflector. This implies a reduction in the additional cells of the 60-cell module by 50% can produce the same amount of energy of the 60-cell module by a 48-cell module with an inverted U reflector. The use of the back reflectors does not only affect the additional energy gain but structural and land costs. Row to row spacing for bifacial systems(arrays) is reduced nearly by half as the ground height clearance is largely minimized, thus almost 50% of height constraints for mounting bifacial modules, using back reflectors resulting in reduced structural costs for mounting of bifacial modules / Dissertation/Thesis / Masters Thesis Mechanical Engineering 2019
295

USING AUTOENCODER TO REDUCE THE LENGTH OF THE AUTISM DIAGNOSTIC OBSERVATION SCHEDULE (ADOS)

Daghustani, Sara Hussain 01 March 2018 (has links)
This thesis uses autoencoders to explore the possibility of reducing the length of the Autism Diagnostic Observation Schedule (ADOS), which is a series of tests and observations used to diagnose autism spectrum disorders in children, adolescents, and adults of different developmental levels. The length of the ADOS, directly and indirectly, causes barriers to its access for many individuals, which means that individuals who need testing are unable to get it. Reducing the length of the ADOS without significantly sacrificing its accuracy would increase its accessibility. The autoencoders used in this thesis have specific connections between layers that mimic the sectional structure of the original ADOS. Autoencoders reduce the length of the ADOS by conducting its dimensionality through combining original variables into new variables. By examining the weights of variables entering the reduced diagnostic, this thesis explores which variables are prioritized and deprioritized by the autoencoder. These information yields insights as to which variables, and underlying concepts, should prioritize in a shorter ADOS. After training, all autoencoders used were able to reduce dimensionality with minimal accuracy losses. Examination of weights yielded many keen insights as to which ADOS variables are the least important to their modules and can thus be eliminated or deprioritized in a reduced diagnostic. In particular, the observation of self-injurious behavior was declared entirely unnecessary in the first three modules of the ADOS, a finding that corroborates other recent experimental results in the domain. This observation suggests that the solutions converged upon by the model have real-world significance.
296

Utah History Learning Activity Modules that Enhance Positive Affective Behavior and Develop Critical and Creative Thinking

Young, Katherine A. 01 May 1979 (has links)
The purpose of this paper was to produce supplementary curriculum materials which would provide junior high school Utah history students with growth experiences in critical thinking, creative thinking, and positive affective values. These materials were produced in the form of forty separate, self-contained learning activity modules using the study of presentday Utah or Utah history as a focus of study. Each Utah history learning activity module consists of two parts: (1) information, and (2) learning activities. The activities engage students to work with factual data to solve problems; to explore moral, ethical, or other controversial issues; or to otherwise develop hypotheses useful in developing critical thinking, creative thinking, or positive affective behavior. Individual differences are met within most modules by alternative activities for students with differing interests and abilities.
297

Qualidade da água e caracterização do perifíton na produção de juvenis de tilápia do nilo em viveiros escavados com o uso de substratos /

January 2019 (has links)
Resumo: O objetivo deste trabalho foi avaliar a influência da produção de perifíton na qualidade da água em viveiros escavados de produção intensiva (7 t/ha1) de juvenis de tilápia do Nilo (Oreochromis niloticus) com baixa renovação da água (6,2% dia-1). O experimento foi iniciado em maio/2018 a julho/2018 com alevinos de tilápia do Nilo com peso médio de 2 gramas e foi encerrado quando os peixes atingiram o peso médio de 35 gramas. Cada unidade experimental foi representada por um viveiro escavado de 130 m2, com água de entrada e saída independentes. O delineamento experimental constou de dois tratamentos e três repetições, sendo testada presença ou ausência de substrato nos viveiros escavados. No tratamento com inclusão de substrato atrator, foram instalados módulos compostos por hastes de bambu ocupando 50% da área superficial do viveiro. Em cada viveiro, foram inseridos módulos de substratos desprotegidos e protegidos dos peixes. Os resultados mostraram que a temperatura, condutividade elétrica, transparência, pH e alcalinidade da água não foram alterados pela produção de perifíton nos substratos de bambu na produção de perifíton nos viveiros escavados no cultivo de juvenis de tilápias do Nilo. A comunidade perifítica presente nos substratos de bambu nas condições deste experimento foi classificada como heterotrófica durante todo o período experimental. A proporção na inserção de substratos de bambu em 50% da área de superfície da água dos viveiros foi suficiente para proporciona... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The objective of this work was to evaluate the influence of the insertion of the bamboo substrate on the water quality in intensive nursery (7 t/ha1) of juvenile Nile tilapia (Oreochromis niloticus) with low water renewal (6.2% Day-1). The experiment was started in 2018/May to 2018/July with Nile tilapia fingerlings with an average weight of 2 grams and was closed when the fish reached the average weight of 35 grams. Each experimental unit was represented by a nursery excavated of 130 m2, with water of independent entrance and exit. The experimental design consisted of two treatments and three replicates, being tested the presence or absence of substrate in the excavated nurseries. In the treatment with inclusion of substrate attractor, modules composed of bamboo stems occupying 50% of the surface area of the nursery were installed. In each nursery, substrate modules were inserted unprotected and protected from fish. The results showed that the temperature, electrical conductivity, transparency, pH and alkalinity of the water were not altered by the inclusion of bamboo substrates in the production of periphyton in nurseries excavated in the cultivation of Nile tilapia juveniles. The periphytic community present in the bamboo substrates under the conditions of this experiment was classified as heterotrophic throughout the experimental period. The proportion in the insertion of bamboo substrates in 50% of the water surface area of the nurseries was sufficient to provide the mai... (Complete abstract click electronic access below) / Mestre
298

An Investigation into the Use of B-Nodes and State Models for Computer Network Technology and Education

KOHLI, Gurpreet, gkohli@student.ecu.edu.au January 2006 (has links)
This thesis consists of a series of internationally published, peer reviewed, conference research papers and one journal paper. The papers evaluate and further develop two modelling methods for use in Information Technology (IT) design and for the educational and training needs of students within the area of computer and network technology. The IT age requires technical talent to fill positions such as network managers, web administrators, e-commerce consultants and network security experts as IT is changing rapidly, and this is placing considerable demands on higher educational institutions, both within Australia and internationally, to respond to these changes.
299

Configurations de connexions de selles et échanges d'intervalles généralisés dans l'espace des modules des différentielles quadratiques

Boissy, Corentin 11 December 2007 (has links) (PDF)
On étudie des familles rigides de connexions de selles sur des surfaces de demi-translation. Les configurations correspondantes sont une première étape pour comprendre la géométrie à l'infini des strates de l'espace des modules des différentielles quadratiques. On étend un résultat de Masur et Zorich en classifiant ces configurations pour chaque composante connexe de strate dès que le genre est supérieur à cinq. <br /><br />On regarde ensuite de façon plus fine des dégénérescences particulières et on prouve en particulier qu'une strate n'admet qu'un seul bout topologique lorsque le genre est zéro.<br /><br />Le lien entre surfaces de translation et échanges d'intervalles fournit un outil puissant pour l'étude du flot de Teichmüller. On propose une généralisation de cette représentation au cadre des différentielles quadratiques. On relie les propriétés géométriques et dynamiques de ces applications à des critères combinatoires explicites portant sur les permutations généralisées associées.
300

Etude et test d'un module accélérateur supraconducteur pour le projet Spiral2

Longuevergne, D. 19 November 2009 (has links) (PDF)
Le projet SPIRAL2, en phase de construction au GANIL à Caen, viendra augmenter les capacités de production et d'accélération de l'actuelle installation SPIRAL. Cette extension consiste en la construction d'une zone de production d'isotopes radioactifs associée à un accélérateur linéaire supraconducteur. Ce dernier permet l'accélération de faisceaux de deutons de 5 mA à 40 MeV ainsi que d'une grande variété d'ions (protons, deutons, ions ayant un rapport charge/masse de 1/3) jusqu'à une énergie de 14.5 MeV/u et un courant de 1 mA. Le taux de fission visé (~ 1014 fissions/s) ainsi que cette grande polyvalence d'accélération sont rendus possible grâce à l'utilisation de la technologie supraconductrice. L'étude, la conception et l'intégration des modules accélérateurs supraconducteurs de la partie haute énergie ont été effectuées à l'Institut de Physique Nucléaire d'Orsay (IPNO). Le travail de thèse présenté ici s'inscrit dans ce contexte. Dans un premier temps, les cavités accélératrices supraconductrices de type quart-d'onde ont été validées et caractérisées d'un point de vue électromagnétique et mécanique en cryostat de qualification (-269 °C). Par la suite, un module accélérateur totalement équipé a été qualifié en configuration dite « machine ». Des études plus spécifiques ont également été menées sur l'effet 100K, les microphonies et la caractérisation du système d'accord en fréquence par plongeur mobile, système novateur pour les cavités supraconductrices. La validation des performances du module accélérateur à travers ce travail de thèse a donné lieu au lancement de la phase de fabrication des cavités accélératrices et des cryomodules.

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