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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.
1

Estudo de um sistema de análise de preferências climáticas para animais convencionais de laboratório por tecnologia de ventilação microambiental e avaliações biológicas. I. Avaliação da eficiência de um protótipo, para o estudo de parâmetros ambientais, resultados parciais verificados em ratos (Rattus norvegicus) / A climatic chamber employing Intracage Ventilation System to evaluated house condition of laboraroty animals and to biological assays in thermoregulation studies. Partial evaluation in rats (Rattus norvegicus)

Chaguri, Luziane do Carmo Andrade Guinski 10 September 2009 (has links)
Projetos desenvolvidos para instalações de animais de laboratório adotam limites estreitos de ventilação e de climatização de ambientes a fim de assegurar um ambiente definido na sala de animais, denominada de macroambiente. Entretanto o tratamento do ar de uma sala não atinge, de forma eficiente, a gaiola em que o animal se encontra alojado (microambiente). O desenvolvimento de sistemas de ventilação microambiental (VMA), que possibilita um fluxo unidirecional de ar forçado para o interior das gaiolas dos animais; associado à modernas tecnologias de termoeletricidade, termosensores e termocontroladores permitem um acurado controle de variáveis climáticas em sistemas microambientais para roedores. No entanto, nota-se carência de dados no que se refere ao binômio temperatura e velocidade do ar para estes sistemas. O objetivo deste estudo foi o desenvolvimento de uma Câmera de Preferencia Climática (CPC) do tipo labiritno que permitisse analise da escolha de ambientes (binômio temperatura e velocidade do ar) para roedores de laboratório. O sistema de Ventilação Microambiental (VMA), possibilitou a climatização da CPC, que foi dividida em quatro sub-camaras, em temperaturas pré-determinadas de 22, 26, 30 e 34oC, todas à uma velocidade de ar de 0,3m/s. A CPC foi mantida numa sala climatizada a 18 ± 2 Co, por um sistema convencional de compressão do freon® para conforto humano. A massa de ar destinada a cada uma das sub-camaras era aquecida via resistência elétrica, controlada eletronicamente, para cada uma das temperaturas pré-determinadas. O comportamento exploratório dos ratos na CPC foi registrado pelo sistema de analise comportamental Ethovision Color-Pro 2.3® e analisado pelos parâmetros de tempo de permanência (Tp) (min.), freqüência de entrada (N) dos animais em cada sub-câmara climatizada e distancia percorrida (cm) dentro da CPC, em um período de 48 horas. Os testes físicos realizados com o equipamento mostraram que este foi capaz de manter as temperaturas pré-determinadas na faixa de &pludmn; 0,1 oC e velocidade de ar constante. Os resultados parciais da analise estatística do comportamento exploratório de ratos demonstraram que, no grupo controle, ou seja, onde as quatro sub-camaras estavam climatizadas em 22 Co, o Tp dos animais em cada uma das sub-camaras foi igual, evidenciando que as condições climáticas eram idênticas e portanto não houve preferência. No grupo experimental, ou seja, com as quatro camaras climatizadas em 22, 26, 30 e 34oC, aleatoriamente, o ratos demonstraram o maior Tp, ou seja, sua preferencia pelas menores temperaturas, 22 e 26oC; à despeito da velocidade de ar de 0,3 m/s, no interior das camaras.A CPC mostrou-se eficiente para estabelecer simulações do microambiente, em termos de preferência climática de roedores mantidos em laboratório. A CPC se mostra como um sistema eficiente também para estudos sobre a termoregulação em ensaios biológicos com animais, como os estudos de neurotoxinas do veneno de aranha Phoneutria nigriventer / Projects concerned with laboratory animals facilities usually adopt narrow range of ventilation and climatization variables to assure the define ambient. Such projects are concerned to the animal room (macro-environmental ambient) and this technology have a limitated operation to reach the micro-environmental (animal cages) ambients. The development of the intracage ventilation systems (ICV), which operating by an air influx inside the cages, beside the new technology on thermoelectric modules, thermosensitive and thermocontrolers materials, allows an accurate control of the microclimatic variables for animal enclosure. For this purpose we developed an experimental prototype, a climatic preference chamber (CPC) that allows to laboratory animal (e.g. rats) choose their preferred ambient under a different temperature conditionated chambers by the ICV thecnology, simulating the animal cage enclosure condition. That technology is characterized by delivery of air insufflation of 0.3 m/s, and regulated with differents temperatures in each chamber (22, 26, 30 and 34oC). The exploratory behavior of the rat at multiplechoise preference test was registered by Ethovision Color-Pro 2.3® system. This system allowed to the analysis of the climatic preference defined by the parameter time spent in different microclimates conditions. The analyses of the exploratory behavior demonstrated that rats spent much time in smaller temperature microclimates, as a 22 and 26 oC, indicating a preference for cooler ambients, in spite of the ICV air speed of 0,3m/s. The aim of this work is simulate laboratory animal housing condition to study the microclimate preference and also in termoregulation studies with laboratory rodents assays, like neurotoxins of the the spider Phoneutria nigriventer venom, that is an important tool to biochemical studies
2

Estudo de um sistema de análise de preferências climáticas para animais convencionais de laboratório por tecnologia de ventilação microambiental e avaliações biológicas. I. Avaliação da eficiência de um protótipo, para o estudo de parâmetros ambientais, resultados parciais verificados em ratos (Rattus norvegicus) / A climatic chamber employing Intracage Ventilation System to evaluated house condition of laboraroty animals and to biological assays in thermoregulation studies. Partial evaluation in rats (Rattus norvegicus)

Luziane do Carmo Andrade Guinski Chaguri 10 September 2009 (has links)
Projetos desenvolvidos para instalações de animais de laboratório adotam limites estreitos de ventilação e de climatização de ambientes a fim de assegurar um ambiente definido na sala de animais, denominada de macroambiente. Entretanto o tratamento do ar de uma sala não atinge, de forma eficiente, a gaiola em que o animal se encontra alojado (microambiente). O desenvolvimento de sistemas de ventilação microambiental (VMA), que possibilita um fluxo unidirecional de ar forçado para o interior das gaiolas dos animais; associado à modernas tecnologias de termoeletricidade, termosensores e termocontroladores permitem um acurado controle de variáveis climáticas em sistemas microambientais para roedores. No entanto, nota-se carência de dados no que se refere ao binômio temperatura e velocidade do ar para estes sistemas. O objetivo deste estudo foi o desenvolvimento de uma Câmera de Preferencia Climática (CPC) do tipo labiritno que permitisse analise da escolha de ambientes (binômio temperatura e velocidade do ar) para roedores de laboratório. O sistema de Ventilação Microambiental (VMA), possibilitou a climatização da CPC, que foi dividida em quatro sub-camaras, em temperaturas pré-determinadas de 22, 26, 30 e 34oC, todas à uma velocidade de ar de 0,3m/s. A CPC foi mantida numa sala climatizada a 18 ± 2 Co, por um sistema convencional de compressão do freon® para conforto humano. A massa de ar destinada a cada uma das sub-camaras era aquecida via resistência elétrica, controlada eletronicamente, para cada uma das temperaturas pré-determinadas. O comportamento exploratório dos ratos na CPC foi registrado pelo sistema de analise comportamental Ethovision Color-Pro 2.3® e analisado pelos parâmetros de tempo de permanência (Tp) (min.), freqüência de entrada (N) dos animais em cada sub-câmara climatizada e distancia percorrida (cm) dentro da CPC, em um período de 48 horas. Os testes físicos realizados com o equipamento mostraram que este foi capaz de manter as temperaturas pré-determinadas na faixa de &pludmn; 0,1 oC e velocidade de ar constante. Os resultados parciais da analise estatística do comportamento exploratório de ratos demonstraram que, no grupo controle, ou seja, onde as quatro sub-camaras estavam climatizadas em 22 Co, o Tp dos animais em cada uma das sub-camaras foi igual, evidenciando que as condições climáticas eram idênticas e portanto não houve preferência. No grupo experimental, ou seja, com as quatro camaras climatizadas em 22, 26, 30 e 34oC, aleatoriamente, o ratos demonstraram o maior Tp, ou seja, sua preferencia pelas menores temperaturas, 22 e 26oC; à despeito da velocidade de ar de 0,3 m/s, no interior das camaras.A CPC mostrou-se eficiente para estabelecer simulações do microambiente, em termos de preferência climática de roedores mantidos em laboratório. A CPC se mostra como um sistema eficiente também para estudos sobre a termoregulação em ensaios biológicos com animais, como os estudos de neurotoxinas do veneno de aranha Phoneutria nigriventer / Projects concerned with laboratory animals facilities usually adopt narrow range of ventilation and climatization variables to assure the define ambient. Such projects are concerned to the animal room (macro-environmental ambient) and this technology have a limitated operation to reach the micro-environmental (animal cages) ambients. The development of the intracage ventilation systems (ICV), which operating by an air influx inside the cages, beside the new technology on thermoelectric modules, thermosensitive and thermocontrolers materials, allows an accurate control of the microclimatic variables for animal enclosure. For this purpose we developed an experimental prototype, a climatic preference chamber (CPC) that allows to laboratory animal (e.g. rats) choose their preferred ambient under a different temperature conditionated chambers by the ICV thecnology, simulating the animal cage enclosure condition. That technology is characterized by delivery of air insufflation of 0.3 m/s, and regulated with differents temperatures in each chamber (22, 26, 30 and 34oC). The exploratory behavior of the rat at multiplechoise preference test was registered by Ethovision Color-Pro 2.3® system. This system allowed to the analysis of the climatic preference defined by the parameter time spent in different microclimates conditions. The analyses of the exploratory behavior demonstrated that rats spent much time in smaller temperature microclimates, as a 22 and 26 oC, indicating a preference for cooler ambients, in spite of the ICV air speed of 0,3m/s. The aim of this work is simulate laboratory animal housing condition to study the microclimate preference and also in termoregulation studies with laboratory rodents assays, like neurotoxins of the the spider Phoneutria nigriventer venom, that is an important tool to biochemical studies
3

Gouttes millimétriques d'eau en milieu confiné : comportement au cours du séchage / Millimetric water drops in confined spaces : behavior during drying

Portuguez, Etienne 15 December 2016 (has links)
Ce travail vise à améliorer la compréhension des mécanismes particuliers du séchage des matériaux céramiques. Cette étape est cruciale lors de la création d’une pièce. En effet, outre l’optimisation de la composition de l’échantillon, la température ainsi que l’humidité relative doivent être contrôlées afin que la perte de masse et le retrait n’entraînent pas l’apparition de contraintes pouvant mener à la création de fissures qui, suite à un traitement thermique, endommageront la pièce finale. Dans un premier temps et après une présentation des différents mécanismes connus du séchage, cette thèse met en avant un ensemble de montages conçus au sein d’une enceinte climatique instrumentée. À l’aide de ces derniers,une première étude portant sur le comportement en température et en humidité du liquide de façonnage seul est réalisée. Ce liquide a ensuite été introduit entre deux substrats identiques et parallèles pour reproduire le cas d’un ménisque au sein d’une porosité. Les contacts hydrophiles et hydrophobes ont alors été étudiés. Enfin, des expériences de séchage ont été menées sur des matériaux céramiques afin de corréler les différentes observations. Les résultats obtenus démontrent l’importance d’un compromis dans le choix des paramètres de séchage. La température et l’humidité relative influencent non seulement la cinétique du procédé lors du départ de l’eau, mais modifient également le contact avec la phase solide de la pièce céramique. En fin de séchage, la rupture des ponts liquides est brutale et peut expliquer certains phénomènes macroscopiques observés lors du séchage de pièces de tailles industrielles. / This work aims at improving the understanding of the specific mechanisms of the drying of ceramic materials. This step is crucial when manufacturing a piece. Indeed, besides the optimization of the sample composition, the temperature and the relative humidity have to be controlled so that the weight loss andthe shrinkage do not cause any stress development, leading to cracks formation which can damage the final piece after a heat treatment. After a presentation of the different known drying mechanisms, this thesis highlights a set of measuring benches conceived within an instrumented climatic chamber. A firststudy concerning the behavior of the shaping liquid as a function of temperature and relative humidity isrealized. Then, this liquid is inserted between two parallel and identical substrates in order to reproduce the case of a liquid bridge within a pore. The hydrophilic and hydrophobic contacts are then studied.Finally, drying experiences are carried out on ceramic materials to correlate the different observations.The obtained results demonstrate the importance of a compromise when selecting the drying parameters.The temperature and the relative humidity not only influence the kinetics of the process during the liquiddeparture, but also modify the contact with the solid phase of the ceramic piece. At the end of drying, the rupture of liquid bridges is brutal and can explain some macroscopic phenomena observed when dryinglarge pieces.
4

Matematicko-fyzikální analýza klimatické komory / Mathematical-physical analysis of climatic chamber

Repko, Ilia January 2018 (has links)
This work deals with the mathematical and physical analysis of the climatic chambers. The theoretical part describes the issue of climatic chambers, software SolidWorks and ANSYS Fluent, basic equations describing fluid status and fluid turbulence. The practical part of the thesis is to create the model of climatic chamber in CAD system SolidWorks and simulation of flow and and temperature distribution by ANSYS Fluent. At the end of the work the results are analyzed and evaluated.
5

Regulační systém pro klimatické zkušební komory / Regulation system for climatic test chambers

Burian, Jan January 2018 (has links)
This paper contains 5 main parts. The first deals with the general description and properties of the climatic chambers, their individual parts and how these parts work. The second part deals with the chamber of Angelantoni CH 340. In detail is described how the chamber works and there is description of this chamber up to individual parts. The third part deals with the reconstruction project, the possibilities of reconstruction and the method that the chamber reconstructed. The fourth part describes the hardware that had to be selected and replaced and which parts of the chamber had to be modified. In the last part is a description of the program that controls the chamber after the reconstruction.
6

Experimentální studium ekologie kriticky ohroženého druhu rozchodníku huňatého / Ecology of critically endangered \kur{Sedum villosum}-experimental study

DILLINGEROVÁ, Hana January 2019 (has links)
The aim of this diploma thesis was to elaborate a literature survey and especially to conduct an experimental study of ecological demands of the critically endangered species Sedum villosum. The localities, on which S. villosum formely occurred, disappeared largely because of habitat destruction by draining and plowing of wet meadows, or by the abandonment followed by development of high vegetation and biomass accumulation. Therefore, this work could contribute to the knowledge of shadow influence and surrounding vegetation concurency on seed germination and flowering of this species. Retrieved knowledge can be later used for rescue program realization (repatriation options, strengthening populations, habitat requirements). The experiments showed a significant negative effect of the shading and the presence of surrounding vegetation (sedges, brown mosses and peat mosses) on germination and flowering of S. villosum. Furthermore, it was found that S. villosum is able to germinate directly on water surface, with seed germination even higher than on wet soil. The experimental sowing, planting and subsequent monitoring of germination, growth and survival of S. villosum at the rehabilitated area of Knížecí Pláně (NP Šumava) showed that it is possible to strengthen S. villosum population by sowing and planting autochthonous material on prepared areas with a torn down turf. As an acceptable tools seems to be using mulch from mown in the area of the original population. Similar process can be used in the future for restoring historical localities of this species.
7

Návrh a realizace vylepšeného měřicího zařízení pro testování induktivních snímačů v klimatické komoře / Design and implementation of improved measuring device for inductive sensors testing in temperature chamber

Šimůnek, Patrik January 2020 (has links)
This thesis deals with the analysis of the measuring equipment for the testing of inductive sensors in the climatic chamber, which mainly highlights the faults and deficiencies of this device. Based on this analysis, a new measurement system is designed to eliminate these or all the deficiencies. Several new useful features are added to the new design of the measuring system.
8

Zjišťování klimatických vlivů na degradaci různých typů fotovoltaických článků / Determination of climatic factor on the degradation of various solar cells types

Peroutka, Tomáš January 2015 (has links)
In this work are discussed photovoltaic cells. There are also discussed basic concepts of radiation source for solar cells. Also mentioned the issue of semiconductors and even the history and evolution of the solar cells. A large part deals with possibilities of photovoltaic cells degradation. In one chapter is an attempt to bring some types of photovoltaic cells and a description of the production of these modules.The practical part deals with photovoltaic modules degradation and its evaluation. Following part compares measured values with the values provided by producer of photovoltaic modules.
9

SW pro ovládání klimatických zkoušek / SW for control of climate tests

Fedor, Denis January 2017 (has links)
This thesis deals with control of a specific climate chamber used for various climate tests. Therefore its elaboration starts with the identification of properties of this climate chamber and basic design of its control. This is followed by measuring the temperature distribution in its internal space in order to verify the usability of this climate chamber. The thesis also does not omit a description of the communication options between climate chamber and application for control of climate tests. The next part of this thesis concerns the design and implementation of the application for control of climate tests itself. On its output is a report of the performed climate test. In the end this thesis contains the description of program testing in the real operation of the company and other possible improvements of the implemented program.
10

Vzduchotěsnost obvodových konstrukcí a kritických detailů / Air tightness of building structures and critical details

Vávra, Petr January 2015 (has links)
In thesis is dealt with problematic of how the value of air permeability may be affected by properties for water vapour diffusion with regard to OSB material There were chosen two main brands of OSB at Czech trade market Two specimens of OSB with different thickness were chosen for each brand. As a first the specimens were tested for air tightness to work out a value of air permeability for each specimen. Afterwords, the testing was conducted for gaining properties of water vapour diffusion on each specimen. As a final assessment was analysed the impact of properties of water vapour diffusion on the air tightness for each specimen. The general meaning of gaining higher air tightness with higher water vapour resistance was proved . It was shown that with raising thickness is usually gotten higher value of water vapour diffusion resistance. However it could not mean getting high air tightness. The crucial parameter is the quality of the material for gaining higher resistance against water vapour diffusion as well as for higher airtightness.

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