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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.
51

Světový trh s osvětlovací technikou a pozice ČR na tomto trhu / Global lighting market and a position of the Czech Republic in this market

Šimetková, Tereza January 2015 (has links)
This thesis is focused on the analysis of the global lighting market and the assessment of the current position of the Czech Republic in this market. The first part is devoted to the theoretical introduction in the field of lighting technology. Furthermore, the thesis deals with the relation between lighting market and energy sector, especially with regard to energy efficiency policy. The market analysis is concentrated primarily on general lighting, which forms the largest and the most important lighting market segment. The development of the Czech lighting market is then discussed in the context of the global as well as the European market. Additionally, the thesis includes analysis of current trends in lighting technology and research conducted among manufacturers of lighting.
52

ON-MACHINE MEASUREMENT OF WORKPIECE FORM ERRORS IN ULTRAPRECISION MACHINING

Gomersall, Fiona January 2016 (has links)
Ultraprecision single point diamond turning is required to produce parts with sub-nanometer surface roughness and sub-micrometer surface profiles tolerances. These parts have applications in the optics industry, where tight form accuracy is required while achieving high surface finish quality. Generally, parts can be polished to achieve the desired finish, but then the form accuracy can easily be lost in the process rendering the part unusable. Currently, most mid to low spatial frequency surface finish errors are inspected offline. This is done by physically removing the workpiece from the machining fixture and mounting the part in a laser interferometer. This action introduces errors in itself through minute differences in the support conditions of the over constrained part on a machine as compared to the mounting conditions used for part measurement. Once removed, the fixture induced stresses and the part’s internal residual stresses relax and change the shape of the generally thin parts machined in these applications. Thereby, the offline inspection provides an erroneous description of the performance of the machine. This research explores the use of a single, high resolution, capacitance sensor to quickly and qualitatively measure the low to mid spatial frequencies on the workpiece surface, while it is mounted in a fixture on a standard ultraprecision single point diamond turning machine after a standard facing operation. Following initial testing, a strong qualitative correlation exists between the surface profiling on a standard offline system and this online measuring system. Despite environmental effects and the effects of the machine on the measurement system, the capacitive system with some modifications and awareness of its measurement method is a viable option for measuring mid to low spatial frequencies on a workpiece surface mounted on an ultraprecision machine with a resolution of 1nm with an error band of ±5nm with a 20kHz bandwidth. / Thesis / Master of Applied Science (MASc)

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