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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.
11

"Desenvolvimento e construção de blocos de concreto radioativo para a calibração de espectrômetros gama portáteis e aerotransportados, utilizados em exploração mineral e de hidrocarbonetos" / Development and Building of Radioactive Concrete Pads for calibration of the airborne and ground gamma-ray spectrometers, used in mineral exploration and hydrocarbons

Dionisio Uendro Carlos 14 March 2006 (has links)
Oito blocos transportáveis para calibração foram construídos para serem utilizados como padrões de concentração na calibração de espectrômetros gama portáteis e aerotransportados. Todo o procedimento de construção é descrito em detalhe. Os blocos, com dimensões de 1 m x 1 m x 0,30 m e massas variando entre 593 kg e 673 kg, devem a sua radioatividade à adição de diferentes quantidades de feldspato potássico (ortoclásio), caldasito e areia monazítica à massa de concreto. As concentrações de potássio, urânio e tório variam significativamente de um bloco para outro atingindo valores máximos de 5,7% de K, 45,6 ppm eU e 137 ppm eTh. A distribuição do fluxo de radiação gama proveniente da superfície dos blocos de concreto e a magnitude das heterogeneidades na concentração dos elementos radioativos foi determinada experimentalmente. Como exemplo de aplicação apresenta-se o resultado da calibração de um espectrômetro gama portátil. / Eight transportable calibration pads were built in to be used as concentration standards for portable and airborne gamma spectrometers calibrations. The pads construction procedure is described in full detail. The pads, with dimensions of 1 m x 1 m x 0,30 m and masses between 593 kg and 673 kg were made radioactive by the addition of different amounts of k-feldspar, caldasite and monazitic sand to the concrete masses. The potassium, uranium and thorium concentration vary significantly in the pads, reaching maximum values of 5,7% of K, 45,6 ppm eU and 137 ppm eTh. The distribution of the gamma radiation flux from the pads surfaces and the heterogeneity magnitudes of the radioactive elements concentration were experimentally established. An example of gamma spectrometer calibration is presented.
12

Extendable ladder cover solution for swedish fire vehicles

Molbeck Blyth, Marco Aurelio, Acosta Vega, María Isabel January 2016 (has links)
The following thesis project has been done in direct collaboration with Autokaross i Floby AB Rescue Vehicle Department, in Sweden.  The report contains the design development of a protective cover against weather conditions for the extendable ladder in a fire vehicle.   The aim of the report has been to develop a functional and low cost solution cover for the FEL on a fire truck, which is allocated on the roof, with the express intention of providing adequate access and protection against weather conditions in Nordic countries, so as to prevent premature deterioration of the FEL unit. The company has set the technical and conceptual boundaries, with the help of the two previous concepts currently used, the BMC and the ACP.   The initial requirements laid out by the company were expressed through a number of specific demands which can be categorized in two main points:   Cost: Designing a solution keeping in mind cost limits, assembly cost and time, and space optimization. This was done by taking into account the two existing solutions, particularly the BMC, which represents the lowest, cost wise and function wise. Therefore it was used as the basis on which to apply improvements, rather than trying to lower the high cost on the overqualified function of the ACP.   Function: Providing the adequate protection and access to the FEL. In this case, the problem was solved by establishing the correct degree of protection relevant to the Nordic weather conditions and FEL needs, and regarding the access, this was assured by fully automating the opening/closing process with the existing extraction operating system of the FEL.     The result of this report is a concept solution which meets the company’s demands, obtained by creative detailing, together with an analysis regarding possible considerations that could improve the creative detailing result in this report in the form of future work.     The report documents the process that has taken place in exploration, concept generation, concept evaluation, concept selection, and detailed CAD development. Each section shows the requirements and adjustments taken to fulfil the company’s needs.

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