655 resultados para Medições


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In this paper we developed a prototype for dynamic and quantitative analysis of the hardness of metal surfaces by penetration tests. It consists of a micro-indenter which is driven by a gear system driven by three-rectified. The sample to be tested is placed on a table that contains a load cell that measures the deformation in the sample during the penetration of micro-indenter. With this prototype it is possible to measure the elastic deformation of the material obtained by calculating the depth of penetration in the sample from the difference of turns between the start of load application to the application of the load test and return the indenter until the complete termination of load application. To determine the hardness was used to measure the depth of plastic deformation. We used 7 types of steel trade to test the apparatus. There was a dispersion of less than 10% for five measurements made on each sample and a good agreement with the values of firmness provided by the manufacturers.

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Na confeção de refeições em cozinhas profissionais, há uma grande geração de calor, substâncias químicas, fumo, vapor de água e odores que vão afetar o ambiente térmico e a qualidade do ar, pondo em causa as condições de trabalho dos seus profissionais. Com o presente trabalho pretendeu-se estudar as condições térmicas a que os trabalhadores estão sujeitos quando confecionam os alimentos. Neste estudo, foram efetuadas medições em diferentes locais em várias cozinhas. Os dados recolhidos foram comparados com a tabela de valores climáticos recomendáveis com base nos dados da ACT. Verificou-se excedências aos valores considerados aceitáveis para as atividades realizadas. Complementarmente, foram inquiridos os trabalhadores, de forma a obter uma avaliação subjetiva e poder comparar com os resultados das medições.

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Metal substrates were coated by thermal spraying plasma torch, they were positioned at a distance of 4 and 5 cm from the nozzle exit of the plasma jet. The starting materials were used for deposition of tantalum oxide powder and aluminium. These two materials were mixed and ground into high-energy mill, then immersed in the torch for the production of alumina coating infused with particles of tantalum with nano and micrometric size. The spraying equipment used is a plasma torch arc not transferred, which operating in the range of 250 A and 80 V, was able to produce enough heat to ignite aluminothermic between Ta2O5 and aluminum. Upon reaching the plasma jet, the mixing powders react with the heat of the blaze, which provides sufficient energy for melting aluminum particles. This energy is transferred through mechanisms of self-propagating to the oxide, beginning a reduction reaction, which then hits on the surface of the substrate and forms a coating on which a composite is formed by a junction metal - ceramic (Ta +Al2O3). The phases and quantification of each were obtained respectively by X-ray diffraction and the Rietveld method. Morphology by scanning electron microscopy and chemical analysis by energy dispersive spectroscopy EDS. It was also performed measurements of the substrate roughness, Vickers microhardness measurements in sprays and determination of the electron temperature of the plasma jet by optical emission spectroscopy EEO. The results confirmed the expectation generated around the end product of spraying the mixture Ta2O5 + Al, both in the formation of nano-sized particles and in their final form. The electron excitation temperature was consistent with the purpose of work, in addition, the thermodynamic temperature was efficient for the reduction process of Ta2O5. The electron excitation temperature showed values of 3000, 4500 and 8000 K for flows10, 20 and 30 l / min respectively, these values were taken at the nozzle exit of the plasma jet. The thermodynamic temperature around 1200 ° C, was effective in the reduction process of Ta2O5

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Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Civil e Ambiental, 2016.

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Dissertação de Mestrado Integrado em Medicina Veterinária

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Dissertação (mestrado)—Universidade de Brasília, Faculdade Gama, Programa de Pós-Graduação em Engenharia Biomédica, 2015.

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The objective of this study is to assess the natural light of the classrooms sectors, at Universidade Federal do Rio Grande do Norte. It was applied the Post-Occupation Evaluation technique, by using questionnaires and brightness levels measurements inside the classrooms. In order to check the users satisfaction degree, it was initially done a general approach on the related aspects to natural light: their characteristics, availability, sources, opening systems and evaluating tools. It was also determined the necessary brightness levels for the activities development in the classroom and the Post-Occupation Evaluation technique used in the search analyses. Then, it was made the UFRN Campus` characterization; the models` definition which formed the data collection basis; the detailing of the procedures used in the research, the processing description and the data analysis. Subsequently, the results that clarify the issues raised were shown through quantitative and / or qualitative data analyses. This research notes a high level of satisfaction by the users, despite some problems such as the reflections occurrence on the board, the lack of uniformity and, occasionally, the brightness low levels

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This research presents a study investigating the correlation between the environmental-physycal charcateristics of cities and the formation of its micro-climates. The study was conducted in the central area of Fortaleza characterized as a stable and consolidated area, where the city originated and currently faces serious problems in its urban dynamics. The points of measurements were determined by the elaboration and analysis of topography maps, height of buildings, land use, type of surface coating and vegetation, following the methodology of Katzschner (1997). A zoning map was then determined, according to common morphological characteristics of the 12 measurement points, which were based on a set of Romero s (2001) bioclimatic criteria. Air measurements, temperature, humidity, intensity and direction of winds were made in transect form in two different circuits in the study area, with six points of data collection in each area, in three different times: 6:00 am, 1:00pm and 7:00pm, during two periods of the year: August 2008 and March 2009. The results verified the influence of different environmental-physical types in the behavior of the climatic variables that were collected. A verticalização tão condenada em algumas situações se bem equilibrada e controlada pode reduzir as temperaturas do ar através do sombreamento dos espaços urbanos e possibilidade de maior permeabilidade a ventilação natural. The highest average air temperature and lower humidity were recorded at the point I at all times. This situation may have been in result of the high density, poor vegetation and extended paving of the ground. According to the results, it s clear the positive influence vegetation has on easing air temperature. Another indicator observed that areas with a greater variation in building heights tend to present decreased average air temperature. High rise structure, planned in accordance to urban air quality parameters, can reduce air temperatures by the shading of urban spaces and the possibility of greater penetration of natural ventilation

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Doutoramento em Engenharia Florestal e dos Recursos Naturais - Instituto Superior de Agronomia - UL

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Mestrado em Engenharia Agronómica - Instituto Superior de Agronomia - UL

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The recent tendency to utilize parking lots for other purposes has demonstrated that more time has been spent by visitors, mainly in great cities. Therefore, this paper investigates the thermal comfort and the air quality indoors in areas specifically used as parking lots by analyzing the direct relation between such environments and vehicular pollution. The thermal comfort and the quality of air indoors in parking lots with different architectonic typology (ground-floor and underground) are also studied, aiming to contribute to the proposition of suitable new areas designated to human usage. Field research was done, in two distinct periods within different weather conditions (January and July) in, two naturally cooled, parking lots located in Natal - RN. The internal environment agents were measured by using tools for air temperature, humidity, speed and direction; interviews with employees and visitors and chemical analysis through appropriate tools to analyze specific material, carbon monoxide and ozone. The results showed that chemical agents densely concentrate mostly in the closed parking space, aggravated by weather conditions, which dissatisfied the visitors. Still, it was shown that architectonic typology, alongside topographical aspects compromise internal environmental conditions, which increases the retention of pollution, leading to dissatisfactory thermal comfort levels and becoming less suitable for usage by visitors considering air and thermal comfort aspects. Consequently, they are not suitable for human stay due to the poor quality of the indoor air

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Dissertação de Mestrado, Ciências Biomédicas, Departamento de Ciências Biomédicas e Medicina, Universidade do Algarve, 2016

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Mestrado em Engenharia Agronómica - Especialização em Horto-fruticultura e Viticultura - Instituto Superior de Agronomia - UL

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The Noise Pollution causes degradation in the quality of the environment and presents itself as one of the most common environmental problems in the big cities. An Urban environment present scenario and their complex acoustic study need to consider the contribution of various noise sources. Accordingly to computational models through mapping and prediction of acoustic scene become important, because they enable the realization of calculations, analyzes and reports, allowing the interpretation of satisfactory results. The study neighborhood is the neighborhood of Lagoa Nova, a central area of the city of Natal, which will undergo major changes in urban space due to urban mobility projects planned for the area around the stadium and the consequent changes of urban form and traffic. Thus, this study aims to evaluate the noise impact caused by road and morphological changes around the stadium Arena das Dunas in the neighborhood of Lagoa Nova, through on-site measurements and mapping using the computational model SoundPLAN year 2012 and the scenario evolution acoustic for the year 2017. For this analysis was the construction of the first acoustic mapping based on current diagnostic acoustic neighborhood, physical mapping, classified vehicle count and measurement of sound pressure level, and to build the prediction of noise were observed for the area study the modifications provided for traffic, urban form and mobility work. In this study, it is concluded that the sound pressure levels of the year in 2012 and 2017 extrapolate current legislation. For the prediction of noise were numerous changes in the acoustic scene, in which the works of urban mobility provided will improve traffic flow, thus reduce the sound pressure level where interventions are expected

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The present study deals with the relationship between urban vegetation and climate. The process whereby the Parque das Dunas a 1,172 ha green area in the city of Natal, State of Rio Grande do Norte exerts influence on the climate of the city is analyzed. The hypothesis on which the present work rests is that the green area referred to acts upon the climate of the city. The study is based on the analysis of climatic factors and elements of this green area and of the city of Natal. In order to give rise to final recommendations, a methodology grounded on a quantitative and qualitative standpoint has been used. The data were collected both within and without the limits of the Parque das Dunas area. Secondary and primary data resulting from the measurements taken by the researcher and her work group have been used. The aim was to contribute to the understanding of the influence of vegetation on the climate of a city having a warm and humid climate. A historical and environmental characterization of the Parque das Dunas was then sought. The local climatic factors and the elements of the climate have been studied within the scope of the city of Natal. A comparative study between the climatic elements within and without the limits of the Parque das Dunas area from the survey of technical data and the systematization of the information collected has been made, aiming at proposing a set of bioclimatic recommendations for the urban design in Natal. The results of such work allowed for the validation of the important role that the Parque das Dunas plays in the climate of Natal. This has led to the acknowledgement of the relevance of the green areas on the climate of cities. They bring about important benefits to the process of rendering agreeable the climate in the urban environment by providing pleasant microclimates that give a valuable contribution to the environmental comfort of urban nuclei having the same size of Natal