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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.
41

Úprava držáku celohliníkového chladiče / Modification of Aluminium Cooler Holder

Malovaný, Daniel January 2013 (has links)
The purpose of this thesis is to overview the basic design solutions of full aluminum radiators. By finite element method to check the first generation of full aluminum low temperature radiator bracket and based on this calculation to modify the design to reduce tension in the critical areas. At the end of this thesis to evaluate the new design.
42

Model-Based Design and Analysis of Thermal Systems for the Ohio State EcoCARMobility Challenge Vehicle

Dalke, Phillip Allen January 2020 (has links)
No description available.
43

A Numerical Study of Radiative Fin Performance with an Emphasis on Geometry and Spacecraft Applications

DeBortoli, Nicholas Sante January 2021 (has links)
No description available.
44

Vehicle engine cooling systems: assessment and improvement of wind-tunnel based evaluation methods

Ng, Eton Yat-Tuen, eton_ng@hotmail.com January 2002 (has links)
The high complexity of vehicle front-end design, arising from considerations of aerodynamics, safety and styling, causes the airflow velocity profile at the radiator face to be highly distorted, leading to potentially reduced airflow volume for heat dissipation. A flow visualisation study showed that the bumper bar significantly influenced the cooling airflow, leading to three-dimensional vortices in its wake and generating an area of relatively low velocity across at least one third of the radiator core. Since repeatability and accuracy of on-road testing are prejudiced by weather conditions, wind-tunnel testing is often preferred to solve cooling airflow problems. However, there are constraints that limit the accuracy of reproducing on-road cooling performance from wind-tunnel simulations. These constraints included inability to simulate atmospheric conditions, limited tunnel test section sizes (blockage effects) and lack of ground effect simulations. The work presented in this thesis involved use of on-road and wind-tunnel tests to investigate the effects of most common constraints present in wind tunnels on accuracy of the simulations of engine cooling performance and radiator airflow profiles. To aid this investigation, an experimental technique for quantifying radiator airflow velocity distribution and an analytical model for predicting the heat dissipation rate of a radiator were developed. A four-hole dynamic pressure probe (TFI Cobra probe) was also used to document flow fields in proximity to a section of radiator core in a wind tunnel in order to investigate the effect of airflow maldistribution on radiator heat-transfer performance. In order to cope with the inability to simulate ambient temperature, the technique of Specific Dissipation (SD) was used, which had previously been shown to overcome this problem.
45

Estimação de parâmetros para um modelo dinâmico de Pára-raios de óxido de zinco. / Estimation of parameters for a dynamic model of zinc oxide arresters.

LIRA, George Rossany Soares de. 03 October 2018 (has links)
Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-10-03T19:27:05Z No. of bitstreams: 1 GEORGE ROSSANY SOARES DE LIRA - DISSERTAÇÃO PPGEE 2008..pdf: 11715881 bytes, checksum: f5c4cfbc8945b506fbbbd6de0fb62705 (MD5) / Made available in DSpace on 2018-10-03T19:27:05Z (GMT). No. of bitstreams: 1 GEORGE ROSSANY SOARES DE LIRA - DISSERTAÇÃO PPGEE 2008..pdf: 11715881 bytes, checksum: f5c4cfbc8945b506fbbbd6de0fb62705 (MD5) Previous issue date: 2008-03-14 / CNPq / Neste trabalho é apresentada uma técnica de estimação de parâmetros para um modelo dinâmico de pára-raios de óxido de zinco (ZnO). Esta técnica baseia-se no ajuste das formas de onda da tensão residual fornecida pelo modelo de pára-raios de ZnO e aquela medida em laboratório, para um impulso de corrente atmosférico (forma de onda 8/20 /xs) de 10 kA. Os resultados fornecidos pelo modelo ajustado demonstraram boa concordância com os dados medidos. Avaliou-se também, o comportamento do modelo de pára-raios, com os parâmetros ajustados, diante impulsos de alta corrente (forma de onda 4/10 /us), os quais são transitórios mais severos do que aqueles utilizados para estimar os parâmetros do modelo. Os resultados obtidos neste estudo apresentaram boa precisão. Por fim, é apresentado um estudo comparativo dos resultados fornecidos pelo modelo de pára-raios, ajustado através da técnica de estimação de parâmetros, com aqueles fornecidos por modelos e procedimentos de ajuste comumente empregados na literatura. Os resultados fornecidos pela técnica de estimação proposta foram mais precisos que todos os demais, além de apresentar as vantagens de dispensar o conhecimento das características físicas dos pára-raios de ZnO e o uso de procedimentos manuais que visam o ajuste dos parâmetros do modelo através de tentativas e erros. / In this work is shown a parameter identification technique for a dynamic metal-oxide surge arrester model. This technique was based on the fitting of the residual voltages measured and obtained from the surge arrester model, from the 10 kA lighting current impulse (waveshape 8/20 //s). The results obtained from the fitted surge arrester model presented a very good accuracy. It was also evaluated, the behavior of the fitted arrester model under high current impulse (waveshape 4/10 (is), which are most severe transients than those used to estimate the arrester model parameters. The results obtained in that study presented good agreement compared to the measured data. At last, it was presented a comparative study of the results provided by the fitted surge arrester model with those provided by models e adjust procedures usually made in the literature. The results provided by the proposed parameter identification technique were more accuratc than the results obtained from the other procedures. Besides, the technique has the advantages of no need to know the metal oxide surge arresters physical characteristics and no use manual procedures, based on try and error, to adjust the arrester model parameters.
46

Segurança alimentar através da determinação de 2-alcilciclobutanonas em alimentos processados por radiação ionizante / Food safety through the determination of 2-alcilciclobutanonas in processed foods by ionizing radiation

ALVES, RODRIGO M. 22 December 2016 (has links)
Submitted by Marco Antonio Oliveira da Silva (maosilva@ipen.br) on 2016-12-22T12:14:15Z No. of bitstreams: 0 / Made available in DSpace on 2016-12-22T12:14:15Z (GMT). No. of bitstreams: 0 / A irradiação de alimentos é um meio de preservação de alimentos onde se utiliza uma técnica de processamento que expõe os alimentos a uma radiação ionizante controlada de alta energia. O tratamento realizado com o uso das radiações ionizantes em alimentos tem muitas aplicações tecnologicamente e tecnicamente viáveis incluindo a capacidade de melhorar a segurança microbiológica, reduzir os níveis de bactérias patogénicas, inibir a germinação de tubérculos, aplicação fitossanitária, conservar alimentos armazenados ou a estabilidade de armazenamento e também é utilizada para aumentar a vida de prateleira de determinados produtos devido à redução da contaminação por microrganismos. Em função do aumento do comércio internacional de alimentos e das crescentes exigências regulatórias dos mercados consumidores, cada vez mais países importadores e exportadores têm demonstrando interesse na irradiação de alimentos e desenvolvido pesquisas na aplicação prática desta tecnologia e de métodos de detecção do tratamento. Inúmeras pesquisas foram realizadas mundialmente, resultando em eficientes protocolos para identificar quais alimentos foram ou não irradiados. Até então, o \"mito\" que alimentos irradiados não poderiam ser detectados e que não eram formados quaisquer produtos únicos da radiação foi substituído pelo conhecimento que muitas mudanças podem ocorrer nos alimentos irradiados e essas mudanças poderiam ser utilizadas como ferramentas para identificar essa tecnologia. O processamento por radiação resulta em formações de padrões característicos de hidrocarbonetos saturados, aldeídos, metil e etil ésteres e 2-alcilciclobutanonas, dependendo da composição do ácido graxo do lipídio que compõe o alimento. Com isso a proposta do trabalho foi levantar dados para comparar os efeitos das diferentes doses de radiação gama e de elétrons em alimentos que possuem gordura para verificar as possíveis alterações decorrentes do uso da irradiação, como a presença de 2-Alcilciclobutanonas e também, mostrar os principais equipamentos utilizados para a irradiação de alimentos e suas categorias, com o objetivo de informar o publico em geral. / Dissertação (Mestrado em Tecnologia Nuclear) / IPEN/D / Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP
47

Návrh vytápění a větrání pro „Emotivní dům“ / Heating and ventilation in the „Emotivní dům“

Brázda, Jan January 2017 (has links)
This master’s thesis deals with the design of the heating and ventilation system for the ‘Emotivní dům’ which was designed by the author of this thesis. The first part of the thesis provides an overview of the project and the architectural design of the house. In the next part, the calculation of the heat loss and the design of the heating and ventilation system is described. War-air heating/ventilation is used in in the habitable rooms of the house with the hydronic system utilized in other spaces. The floor heating is used in the bathrooms and the other non-habitable spaces, such as the garage, are heated with radiators. A natural gas boiler is used as a heat source for both space heating and domestic hot water heating. The thesis contains the floor plans of the house as well as technical drawings of the heating and ventilation system.
48

Forenzní analýza prostředí IoT ze stop síťové komunikace / Forensic Analysis of the IoT Environment from Network Communication Traces

Slámová, Hana January 2021 (has links)
The goal of this master's thesis is a creation of dataset capturing selected users' activities, network analysis of this dataset, design and implementation of method to detect selected users' activities and discussion of achieved results. 4 devices have been chosen for the creation of this dataset.
49

Tepelná čerpadla ve vytápění / Heat pumps in heating systems

Zaťková, Miroslava January 2013 (has links)
This master´s thesis addresses heating of the new three - storey office building, which is located in Brno Pisárky. The heating system is designed as a low-temperature system with forced circulation of water using mostly panel radiators. As the heat source was designed two variants. The first heat source is the heat pump air - water, which is installationed inside. The second heat source is a gas condensing boiler. The part of design is preparation hot water. Ventilation of the building is equal-forced. Experimental part of master´s thesis is focused on measuring the amount of electricity produced per year by photovoltaic panels on the existing house in Brno Pisárky. Thesis also includes measuring outdoor temperature and intensity of solar radiation. The result is a comparison of the need for electricity for the heat pump for heating family house, total electricity consumption family house and amount of electricity produced by photovoltaic panels.
50

Vytápění objektu hotelového typu plynovým médiem a alternativním zdrojem / Hotel type building heating gas and alternative media source

Byrtus, Miroslav January 2014 (has links)
Proposal for heating the building of the hotel type. The first part describes the detailed description and analysis of heat sources proposed in the third part, which are gas-fired condensing boilers, fireplaces and stoves. In the second part we find two technical solutions involvement boiler room. The third section contains solutions for selected variants.

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