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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

Koncept på ett hydrauliskt mothåll / Concept of a hydraulic counter hold

Sharef, Hajan, Potari, Marek January 2016 (has links)
New technology in the automotive industry is the key to success. Therefore, it is appreciated when people come with new design ways to solve problems. This leads to innovation in the automotive industry that will lead to better and more environmentally friendly cars. This report presents a concept on a pushing counter lever spring which provides the same characteristics of force curve as a diaphragm spring in a pressure plate of a car has. The mechanism is to be used for long-term testing and evaluating clutch pedals. The work describes the development process and the manufacture of a prototype. The program Creo (CAD / 3D) is largely used to construct the components. As are the subprograms Mechanism Design and Simulate to simulate the movement and loads. Excel is a great help at the theoretical calculation of the mechanism and to evaluate the theory behind the concept. The result shows how to simulate a diaphragm spring in the pressure plate in a car for long-term testing of clutch pedals. The goal is to accurately mimic the force curve of a diaphragm spring, in order to design better pedals, and thus reduce the weight on the pedals to in turn reduce fuel consumption to protect the environment is one of the most important factors of all in the automotive industry.
2

O conceito de equilíbrio hidráulico e termodinâmico da água no solo aplicado ao estudo da curva de retenção e murchamento de plantas / The concept of hydraulic and thermodynamic equilibrium of soil water applied to the study of soil water retention curve and plant wilting

Torres, Lorena Chagas 19 February 2016 (has links)
Estimativas sobre alterações climáticas globais têm aumentando a demanda por estudos sobre propriedades dos solos relativamente secos e limitações impostas à absorção de água pelas plantas em condições de escassez hídrica. Neste estudo, fatores que influenciam a retenção da água no solo e o murchamento de plantas foram avaliados com base no conceito de equilíbrio da água no solo. Objetivou-se com este estudo: (i) avaliar a confiabilidade de medições do conteúdo de água no solo sob altas sucções matriciais em câmaras de pressão, usando como referência a técnica de ponto de orvalho (ii) avaliar as interações entre espécies de plantas e solos com diferentes classes texturais no ponto de murcha permanente (iii) investigar as relações entre equilíbrio hidráulico da água no solo e murchamento de plantas a partir do conceito de corte hidráulico. Para tanto, um experimento para avaliar a influência dos tipos de solos e espécies de plantas, no ponto de murcha permanente foi conduzido em casa de vegetação da Escola Superior de Agricultura \"Luiz de Queiroz\" da Universidade de São Paulo, Piracicaba, São Paulo. Avaliou-se o murchamento de plantas de girassol (Helianthus annuus L.), milho (Zea mays L.) e soja (Glycine max L.). Os solos utilizados no estudo foram coletados na camada superficial (0-10 cm) em quatro áreas, selecionadas com o objetivo de obter classes texturais contrastantes, localizadas no município de Piracicaba, São Paulo, Brasil. Sub-amostras foram utilizadas para determinação da distribuição do tamanho de partículas e atributos químicos. Amostras indeformadas foram coletadas para a determinação da curva de retenção da água no solo pela técnica de câmaras de pressão. Adicionalmente, amostras deformadas foram utilizadas para determinação das características de retenção da água no solo pela técnica do ponto de orvalho em altos valores de sucções matriciais. Os dados de retenção de água no solo foram ajustados a modelos empíricos para estimativas da sucção matricial e conteúdo de água relacionada à água em equilíbrio hidráulico (água residual). Foram observadas similaridades nas determinações das características de retenção da água no solo entre as técnicas de câmaras de pressão e ponto de orvalho, sugerindo a boa drenagem das amostras de solo em câmaras de pressão. Interações significativas foram observadas entre os tipos de solos e espécies de plantas no ponto de murcha permanente, indicando que o movimento de água no contínuo solo-planta-atmosfera foi dependente de resistências relacionadas tanto ao solo quanto às plantas. Ou seja, tanto à capacidade do solo em transportar água até raízes, quanto à habilidade das plantas em absorver a água transportada, assim como, aos processos de regulação de água que ocorrem nas plantas. A abordagem baseada no conteúdo de água residual para o intervalo de sucções matriciais de 0 a 15.000 hPa não foi adequada para ilustrar a condição de equilíbrio hidráulico da água no solo, definidos pelo corte hidráulico, e relações com as sucções matriciais em ocorre o murchamento de plantas. / Estimates about climate changes have increased the demand for studies of the properties of relatively dry soil and limitations on the plants water uptake in conditions of water scarcity. In this study, factors influencing the soil water retention and wilting plants were evaluated based on the concept of soil water equilibrium. The objectives of this study were: (i) to evaluate the reliability measurements of the soil water retention on pressure plate apparatus at high matric suctions using as reference the dew point meter (ii) to evaluate the interactions between soil types and plant species at permanent wilting point (iii) investigate the relationship between the hydraulic equilibrium of soil water and the plant wilting based on the hydraulic cut-off concept. A pot experiment to evaluate the effect of plant and soil types at permanent wilting point was carried out in a greenhouse at the Agricultural\'s College \"Luiz de Queiroz\" from University of São Paulo in Piracicaba, São Paulo, Brazil. Soil samples were collected at the topsoil (0-10 cm) from four different locations around the city of Piracicaba, São Paulo, Brazil. Subsamples were taken to determine the particle size distribution and chemical analysis. To determine soil water retention curve 30 soil samples were collected with undisturbed soil cores. The soils were selected to have a range of texture and organic carbon content. The wilting was evaluated using plants of sunflower (Helianthus annuus L.), maize (Zea mays L.) and soybean (Glycine max L.). The soil water retention data were fitted to the empirical models for estimating the matric suction and water content related soil water at hydraulic equilibrium (residual water content). Similar soil water content were observed for measurements at pressure plate apparatus and dew point meter, suggesting good drainage of the soil samples in pressure plate apparatus for the dry range of soil water retention curve. Significant interactions were observed between soil types and plant species at permanent wilting point, indicating that the water movement in the soil-plant-atmosphere continuum was dependent of resistances related to soil and the plants properties. The approach based on the residual water content for the matric suctions from 0 to 15,000 hPa was not adequate to illustrate the hydraulic equilibrium of the soil water defined by the cut-hydraulic and relations with the matric suction at wilting plants.
3

O conceito de equilíbrio hidráulico e termodinâmico da água no solo aplicado ao estudo da curva de retenção e murchamento de plantas / The concept of hydraulic and thermodynamic equilibrium of soil water applied to the study of soil water retention curve and plant wilting

Lorena Chagas Torres 19 February 2016 (has links)
Estimativas sobre alterações climáticas globais têm aumentando a demanda por estudos sobre propriedades dos solos relativamente secos e limitações impostas à absorção de água pelas plantas em condições de escassez hídrica. Neste estudo, fatores que influenciam a retenção da água no solo e o murchamento de plantas foram avaliados com base no conceito de equilíbrio da água no solo. Objetivou-se com este estudo: (i) avaliar a confiabilidade de medições do conteúdo de água no solo sob altas sucções matriciais em câmaras de pressão, usando como referência a técnica de ponto de orvalho (ii) avaliar as interações entre espécies de plantas e solos com diferentes classes texturais no ponto de murcha permanente (iii) investigar as relações entre equilíbrio hidráulico da água no solo e murchamento de plantas a partir do conceito de corte hidráulico. Para tanto, um experimento para avaliar a influência dos tipos de solos e espécies de plantas, no ponto de murcha permanente foi conduzido em casa de vegetação da Escola Superior de Agricultura \"Luiz de Queiroz\" da Universidade de São Paulo, Piracicaba, São Paulo. Avaliou-se o murchamento de plantas de girassol (Helianthus annuus L.), milho (Zea mays L.) e soja (Glycine max L.). Os solos utilizados no estudo foram coletados na camada superficial (0-10 cm) em quatro áreas, selecionadas com o objetivo de obter classes texturais contrastantes, localizadas no município de Piracicaba, São Paulo, Brasil. Sub-amostras foram utilizadas para determinação da distribuição do tamanho de partículas e atributos químicos. Amostras indeformadas foram coletadas para a determinação da curva de retenção da água no solo pela técnica de câmaras de pressão. Adicionalmente, amostras deformadas foram utilizadas para determinação das características de retenção da água no solo pela técnica do ponto de orvalho em altos valores de sucções matriciais. Os dados de retenção de água no solo foram ajustados a modelos empíricos para estimativas da sucção matricial e conteúdo de água relacionada à água em equilíbrio hidráulico (água residual). Foram observadas similaridades nas determinações das características de retenção da água no solo entre as técnicas de câmaras de pressão e ponto de orvalho, sugerindo a boa drenagem das amostras de solo em câmaras de pressão. Interações significativas foram observadas entre os tipos de solos e espécies de plantas no ponto de murcha permanente, indicando que o movimento de água no contínuo solo-planta-atmosfera foi dependente de resistências relacionadas tanto ao solo quanto às plantas. Ou seja, tanto à capacidade do solo em transportar água até raízes, quanto à habilidade das plantas em absorver a água transportada, assim como, aos processos de regulação de água que ocorrem nas plantas. A abordagem baseada no conteúdo de água residual para o intervalo de sucções matriciais de 0 a 15.000 hPa não foi adequada para ilustrar a condição de equilíbrio hidráulico da água no solo, definidos pelo corte hidráulico, e relações com as sucções matriciais em ocorre o murchamento de plantas. / Estimates about climate changes have increased the demand for studies of the properties of relatively dry soil and limitations on the plants water uptake in conditions of water scarcity. In this study, factors influencing the soil water retention and wilting plants were evaluated based on the concept of soil water equilibrium. The objectives of this study were: (i) to evaluate the reliability measurements of the soil water retention on pressure plate apparatus at high matric suctions using as reference the dew point meter (ii) to evaluate the interactions between soil types and plant species at permanent wilting point (iii) investigate the relationship between the hydraulic equilibrium of soil water and the plant wilting based on the hydraulic cut-off concept. A pot experiment to evaluate the effect of plant and soil types at permanent wilting point was carried out in a greenhouse at the Agricultural\'s College \"Luiz de Queiroz\" from University of São Paulo in Piracicaba, São Paulo, Brazil. Soil samples were collected at the topsoil (0-10 cm) from four different locations around the city of Piracicaba, São Paulo, Brazil. Subsamples were taken to determine the particle size distribution and chemical analysis. To determine soil water retention curve 30 soil samples were collected with undisturbed soil cores. The soils were selected to have a range of texture and organic carbon content. The wilting was evaluated using plants of sunflower (Helianthus annuus L.), maize (Zea mays L.) and soybean (Glycine max L.). The soil water retention data were fitted to the empirical models for estimating the matric suction and water content related soil water at hydraulic equilibrium (residual water content). Similar soil water content were observed for measurements at pressure plate apparatus and dew point meter, suggesting good drainage of the soil samples in pressure plate apparatus for the dry range of soil water retention curve. Significant interactions were observed between soil types and plant species at permanent wilting point, indicating that the water movement in the soil-plant-atmosphere continuum was dependent of resistances related to soil and the plants properties. The approach based on the residual water content for the matric suctions from 0 to 15,000 hPa was not adequate to illustrate the hydraulic equilibrium of the soil water defined by the cut-hydraulic and relations with the matric suction at wilting plants.
4

Objektivizace opěrné báze kojenců na přelomu prvního a druhého trimenonu pomocí tlakového senzoru Conformat - pilotní studie / Objectification of supporting base of infants at the edge of third and fourth month via using a pressure plate Conformat - pilot study

Janoušek, David January 2016 (has links)
The goal of this thesis is to contribute to discovering a method which can lead to objectification of support base of infants in prone position at the edge of third and fourth month. The motor development during first six months is described in this thesis based on literature search. Part of the thesis is dedicated to selected primitive reflexes and postural reactions. Furthermore, the work deals with objectification of support base of infants at the edge of third and fourth month. In the study were evaluated 10 infants (5 males and 5 females) with average age 14,01 ± 2,2 weeks. Distribution of support was assessed in three situations such as prone position, prone position with maximal rotation of head to the left and prone position with maximal rotation of head to the right. The results did not show significant difference in weight bearing the left and right upper extremity in prone position. However there was a significant difference in weight bearing in the upper extremities during head rotation. The upper extremity on the side of rotation was more loaded. The weight applied to the upper and lower extremities was significantly different in every evaluated situation. Upper extremities were always weighted more. Keywords Supporting base, developmental kinesiology, postural reactions, primitive...
5

Capillary pore-size distribution and equilibrium moisture content of wood determined by means of pressure plate technique

Zauer, Mario, Meissner, Frank, Plagge, Rudolf, Wagenführ, André 23 June 2020 (has links)
This paper deals with the determination of the capillary pore-size distribution (CPSD) and equilibrium moisture content (EMC) of untreated and thermally modified (TM) Norway spruce [Picea abies (L.) Karst.] by means of the pressure plate technique (PPT). Desorption experiments were conducted at very high values of relative humidity (RH) in the range between 99.2% and 100%. The thermal modification of spruce results in an alteration of the CPSD, owing to the formation of intercellular cracks in the middle lamella, as a result of cell-wall compression. The desorption curves for both untreated and TM spruce show an extremely upward bend at 99.97% RH. This step reflects an EMC of 38.1% for untreated spruce and 33.8% for TM spruce. None of the samples shrunk during the PPT measurements. Following desorption experiments at 97.4% RH, all samples shrunk. This step reflects an EMC of 27.9% for untreated spruce and 21.7% for TM spruce.

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