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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

The early development of the reflecting telescope in Britain

Simpson, Allen David Cumming January 1981 (has links)
The first effective demonstration of a telescope using reflecting optics was made by Isaac Newton, and his invention was given widespread publicity by the Royal Society of London in 1672. Newtonts instrument was closely associated with the introduction of his new theory of the nature of white light and colour, and for Newton his telescopes practicability remained important to the acceptance of his optical theory. Newtonts telescope, influenced to some extent by the earlier work of James Gregory, encouraged the Royal Society to promote more ambitious trials, but instruments by Robert Hooke and Christopher Cock, and by Newton himself, achieved only limited success. Renewed interest in the reflector followed its re- emergence in Newtonts Opticks of 1704. John Hadleyes successful revival of Newtones instrument led in turn to the establishment in London of competitive commercial manufacture of reflectors in the early 18th century, and by 1710 the market was dominated by the instruments of James Short. Contemporary references to the reflecting telescopes of Newton and others have been analysed to allow the historical development of this work to be established more reliably, and to propose a relationship between the various instruments that may be ascribed to Newton. The emphasis has therefore been placed on the instrumentation itself, on practical detail, and on questions of provenance.
42

An experimental study of techniques in thermoluminescence dating

Colvin, Glenn Geoffrey January 1981 (has links)
The phenomenon of thermoluminescence (TL) cannot yet be said to be completely understood, and cases of anomalous results from TL dating programmes are not infrequent, although explanations are rarely given. It is therefore useful to put TL dating into a firmer physical framework in which all relevant phenomena can be adequately described, whence the best action can be taken to avoid spurious results. However, TL dating embraces many varied aspects of physics, and a solution to all the problems is not a simple task. This thesis is intended to be an experimental study of some of the main physical techniques in thermoluminescence dating. Following a brief review of the whole field, selected areas presented here have been investigated in more detail. A new TL reader has been implemented with novel design features, including microprocessor controlled heating cycles, a switch-mode power supply direct current heating, all based on a modular concept to facilitate future improvements in the hardware. The use of a microprocessor as the heating controller should enable further development (eg. data collection and processing) to be a straightforward task. Non-linear heating profiles can be generated for glow curve analysis and for providing pre-heat zones. The radioisotope content of ceramics and soils is important in TL dating, and a comparison of commonly used radio assay techniques has been made with the aim of assigning a minimum detectable activity to each technique for a given required accuracy. The analytical methods have been applied to various ceramic samples, and the derived dose rates within the shards are calculated and presented for comparison. Some theoretical aspects of TL described in this thesis include a computer model to simulate common TL phenomena, which is used to investigate the effects of varying the model parameters. A complete solution of the equations determining glow curve shapes produced by hyperbolic heating profiles is presented, with techniques for extracting the mathematical constants describing the model, from them. A brief intercomparison of five quartz samples of differing origins is presented with a trace element analysis of the samples to determine whether there exists a correlation between trace element concentration and the magnitude of the TL properties.
43

Robustness of Kalman filter-based fault detection methods

Newman, Ronald Scott January 1982 (has links)
No description available.
44

Guided wave inspection of embedded cylindrical structures

Beard, Malcolm David January 2002 (has links)
No description available.
45

The non-destructive testing of plates using ultrasound Lamb waves

Alleyne, David N. January 1991 (has links)
No description available.
46

Rotable designs : construction and considerations in the robust design of experiments

Huda, S. January 1981 (has links)
No description available.
47

Projeto de um laboratorio integrado de calibracao de instrumentos no IPEN / Project of an integrated calibration laboratory of instruments at IPEN

BARROS, GUSTAVO A.S.J. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:26:20Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:04:32Z (GMT). No. of bitstreams: 0 / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
48

Projeto de um laboratorio integrado de calibracao de instrumentos no IPEN / Project of an integrated calibration laboratory of instruments at IPEN

BARROS, GUSTAVO A.S.J. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:26:20Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:04:32Z (GMT). No. of bitstreams: 0 / O Laboratório de Calibração de Instrumentos do Instituto de Pesquisas Energéticas e Nucleares oferece serviços de calibração de detectores de radiação utilizados em radioproteção, radiodiagnóstico e radioterapia, para o IPEN e também para instalações externas, públicas e particulares. Uma parte de suas instalações estão localizadas no prédio principal, junto com outros laboratórios e salas de estudo, e uma outra parte num prédio isolado, semienterrado (Bunker). Para a otimização, a modernização e principalmente a segurança, os laboratórios situados no prédio principal precisam ser transferidos para um local isolado. Neste trabalho foi desenvolvido um projeto de um laboratório integrado, que será uma expansão do atual Laboratório de Calibração de Instrumentos do IPEN. Para isto, foram feitos levantamentos radiométricos no local escolhido e levantadas todas as necesidades da equipe quanto a espaço e disposição das salas. No projeto, os laboratórios com equipamentos de radiação X, e fontes radioativas alfa e beta ficaram isolados numa parte do prédio, e as blindagens das paredes foram determinadas, dependendo do uso de cada laboratório. / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
49

Projeto e implementação do equipamento para tomografia com nêutrons do IPEN-CNEN/SP / Design and development of a neutron tomography facility at the IPEN-CNEN/SP

SCHOUERI, ROBERTO M. 22 June 2016 (has links)
Submitted by Claudinei Pracidelli (cpracide@ipen.br) on 2016-06-22T12:49:00Z No. of bitstreams: 0 / Made available in DSpace on 2016-06-22T12:49:00Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado em Tecnologia Nuclear) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
50

Projeto e implementação do equipamento para tomografia com nêutrons do IPEN-CNEN/SP / Design and development of a neutron tomography facility at the IPEN-CNEN/SP

SCHOUERI, ROBERTO M. 22 June 2016 (has links)
Submitted by Claudinei Pracidelli (cpracide@ipen.br) on 2016-06-22T12:49:00Z No. of bitstreams: 0 / Made available in DSpace on 2016-06-22T12:49:00Z (GMT). No. of bitstreams: 0 / Na presente dissertação, foi desenvolvido um equipamento para tomografia com nêutrons que está operacional e instalado no canal de irradiação 14 do Reator Nuclear de Pesquisas IEA-R1 do IPEN-CNEN/SP. As imagens apresentadas neste trabalho, são de objetos que foram selecionados de modo a realçarem uma das principais aplicações da técnica, que é o estudo de materiais hidrogenados mesmo se envoltos por espessa camada de alguns metais. Neste equipamento, uma tomografia completa pode ser obtida em 400 s, com uma resolução espacial máxima de 205 μm. Estas características são comparáveis às dos equipamentos mais desenvolvidos em operação em outros países, e propiciam imagens com qualidade suficiente para que sejam realizadas análises tanto qualitativas quanto quantitativas dos objetos inspecionados. A implementação da técnica da tomografia com nêutrons abre a possibilidade de novas linhas de pesquisa, pois disponibiliza uma nova ferramenta para inspeção de objetos, que fornece uma visão da sua estrutura interna, que nem sempre é possível por métodos de imageamento bidimensional. / Dissertação (Mestrado em Tecnologia Nuclear) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

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