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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

Technologie obrábění tvrdých materiálů nástroji s definovanou geometrií břitu / Hard machining with defined geometry edge tools

Bukáček, Zdeněk January 2009 (has links)
This master’s thesis is concerned with subject matter hard machining with defined geometry edge tools. Aim master’s thesis is analysis and parameters evaluation machined surface at hard machining. This master’s thesis contain a characteristic of hard materials, used technology for cutting operation, but also tools and cutting conditions suitable for hard machining. In the conclusion are parameters evaluation machined surface the workpiece.
12

Funções de predição espacial de propriedades do solo / Spatial prediction functions of soil properties

Rosa, Alessandro Samuel 27 January 2012 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / The possibility of mapping soil properties using soil spatial prediction functions (SSPFe) is a reality. But is it possible to SSPFe to estimate soil properties such as the particlesize distribution (psd) in a young, unstable and geologically complex geomorphologic surface? What would be considered a good performance in such situation and what alternatives do we have to improve it? With the present study I try to find answers to such questions. To do so I used a set of 339 soil samples from a small catchment of the hillslope areas of central Rio Grande do Sul. Multiple linear regression models were built using landsurface parameters (elevation, convergence index, stream power index). The SSPFe explained more than half of data variance. Such performance is similar to that of the conventional soil mapping approach. For some size-fractions the SSPFe performance can reach 70%. Largest uncertainties are observed in areas of larger geological heterogeneity. Therefore, significant improvements in the predictions can only be achieved if accurate geological data is made available. Meanwhile, SSPFe built on land-surface parameters are efficient in estimating the psd of the soils in regions of complex geology. However, there still are questions that I couldn t answer! Is soil mapping important to solve the main social and environmental issues of our time? What if our activities were subjected to a social control as in a direct democracy, would they be worthy of receiving any attention? / A possibilidade de mapear as propriedades dos solos através do uso de funções de predição espacial de solos (FPESe) é uma realidade. Mas seria possível construir FPESe para estimar propriedades como a distribuição do tamanho de partículas do solo (dtp) em um superfície geomorfológica jovem e instável, com elevada complexidade geológica e pedológica? O que seria considerado um bom desempenho nessas condições e que alternativas temos para melhorá-lo? Com esse trabalho tento encontrar respostas para essas questões. Para isso utilizei um conjunto de 339 amostras de solo de uma pequena bacia hidrográfica de encosta da região Central do RS. Modelos de regressão linear múltiplos foram construídos com atributos de terreno (elevação, índice de convergência, índice de potência de escoamento). As FPESe explicaram mais da metade da variância dos dados. Tal desempenho é semelhante àquele da abordagem tradicional de mapeamento de solos. Para algumas frações de tamanho o desempenho das FPESe pode chegar a 70%. As maiores incertezas ocorrem nas áreas de maior heterogeneidade geológica. Assim, melhorias significativas nas predições somente poderão ser alcançadas se dados geológicos acurados forem disponibilizados. Enquanto isso, FPESe construídas a partir de atributos de terreno são eficientes em estimar a dtp de solos de regiões com geologia complexa e elevada instabilidade. Mas restam dúvidas que não consegui resolver! O mapeamento de solos é importante para a resolução dos principais problemas sociais e ambientais do nosso tempo? E se nossas atividades estivessem submetidas ao controle da população como em uma democracia direta, seriam elas dignas de receber atenção?
13

Využití analýzy parametrů textury povrchu při výrobě pistole / Use of surface texture parameters analysis in the manufacture of a pistol

Rožnovský, Michal January 2019 (has links)
The diploma thesis deals with the analysis of surface texture parameters during pistol production. The aim of the diploma thesis was to formulate requirements for pistol quality, to analyze the existing production process of the chosen pistol component, to analyze the texture of the functional surface after selected technological operations with a proposal for correction of the manufacturing process and recommendations for practice. The work includes mapping the life cycle of the pistol with a focus on the technological procedure of processing the main part of the pistol - the slide of the pistol. The surface texture of surface texture is also described, depending on the measurement of the defined area. Based on 250 measured and evaluated surface texture parameters, recommendations for correction of the manufacturing process and recommendations for the design and development of the pistol were formulated.
14

Experimentální ověření pasivních prvků tepelné regulace družic / Experimental study on satellite´s passive thermal-regulation units

Mateášik, Timko Marek January 2021 (has links)
Diplomová práca sa zaoberá vplyvom termálnych medzivrstiev na tepelnú kontaktnú vodi- vosť a tepelný kontaktný odpor. Práca sa zameriava na aplikáciu termálnych medzivrstiev pre vylepšenie tepelnej kontaktnej vodivosti v tepelnom spínači a v kozmických zariade- niach obecne. Teoretická časť práce stručne skúma rôzne pasívne termálne kontrolné systémy použí- vane v kozmických zariadeniach, vrátane termálnych medzivrstiev, a vysvetľuje pozadie tejto práce. Táto práca ďalej skúma rôzne termálne medzivrstvy, predovšetkým povlaky a fólie, a uvádza výber vhodnej termálnej medzivrstvy. Experimentálna časť práce skúma povrchové parametre, tepelnú vodivosť a mikrotvr-dosť medených vzoriek, ktoré slúžia ako substrát pre povlak čistého striebra. Ďalej rieši podmienky merania, metódy vyhodnocovania a samotné experimentálne merania. Experimentálne merania sú vykonané v termo-vákuovej testovacej komore a na základe výsledkov sú vyvodené závery. Pre ďalšiu prácu sú uvedené doporučenia.

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