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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.
1

Estudo da eletrodeposição e eletrocorrosão em suportes metálicos, para uso em biossensores eletroquímicos.

EULÁLIO, Hugo Yves Cordeiro. 21 November 2017 (has links)
Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2017-11-21T21:46:23Z No. of bitstreams: 1 Hugo Yves Cordeiro Eulálio - Dissertação PPG-CEMat - 2016..pdf: 9966635 bytes, checksum: 5ea265c58dad0db100d0e913e7338764 (MD5) / Made available in DSpace on 2017-11-21T21:46:23Z (GMT). No. of bitstreams: 1 Hugo Yves Cordeiro Eulálio - Dissertação PPG-CEMat - 2016..pdf: 9966635 bytes, checksum: 5ea265c58dad0db100d0e913e7338764 (MD5) Previous issue date: 2016-02-29 / Um dos desafios da atualidade está em encontrar métodos simples, rápidos e seletivos para determinações específicas de compostos variados nas mais diversas aplicações. Um componente fundamental para os biossensores, tratase do transdutor, responsável por transformar e conduzir os sinais gerados devido as reações entre analito alvo e biorreceptor. Em testes iniciais viu-se que a deposição se soltava facilmente da superfície do eletrodo então com o intuito de melhorar a condutividade dos eletrodos foi realizado eletrodeposições do composto Sb/Sb2O3 nas superfícies dos suportes metálicos e visando uma melhor adesão do eletrodepositado nos metais foram realizadas eletrocorrosões nestes suportes com solução de HCl. O objetivo deste trabalho foi analisar o comportamento de suportes metálicos para transdutores, submetidos a eletrodeposição de antimônio e de óxido de antimônio (Sb/Sb2O3) e ao processo de eletrocorrosão ácida, para o emprego em biossensores. Com a finalidade de identificar qual composto estava sendo depositado no metal, para visualizar a morfologia e o recobrimento e, ainda, confirmar essa possível melhor adesão realizou-se caracterizações como: microscopia eletrônica de varredura, difração de raios x, análise gravimétrica das amostras, análise da rugosidade superficial e testes de adesividade do depositado. A partir dos difratogramas foi possível observar a eletrodeposição do Sb metálico na superfície metálica. As imagens obtidas por MEV mostraram morfologias distintas que variaram dependendo do metal utilizado, da metodologia utilizada, porém todos apresentaram uma característica pulverulenta, pois são facilmente arrancados da superfície. O teste de gravimetria acusou que o cobre é mais sensível a corrosão que o aço inox. O teste de adesão mostrou que na média o cobre obteve uma maior adesão, porém a amostra que teve maior adesão foi utilizando uma fita de aço. Conclui-se que dentre os dois suportes metálicos escolhidos, levando em consideração apenas o tratamento superficial e a metodologia utilizada, o aço inox é o melhor suporte a ser empregado. / One of nowadays' challenges is to find simple, fast and selective methods for specific determinations of various compounds in various applications. A key component to the biosensor, is the transducer, responsible for transforming and lead the signals generated due to reactions between the target analyte and biorreceptor. In initial tests it was seen that the deposition easily let go of the electrode surface then, to improve the conductivity, they were conducted electrodeposition compound Sb / Sb2O3 on the surfaces of metal brackets and to better adhesion of the electroplated in metals were performed electroerosions on these stands with HCl solution. The aim of this study was to analyze the metal brackets behavior for transducers subjected to electrodeposition of antimony and antimony oxide (Sb / Sb2O3) and acid electroerosion process, for use in biosensors. In order to identify which compound was being deposited on the metal, to see the morphology and the coating and also confirm this possible better adhesion some characterizations were done, as scanning electron microscopy, X-ray diffraction, gravimetric analysis of the samples, analysis of surface roughness and deposited adhesion tests. From the XRD patterns was observed only the electrodeposition of Sb metallic on the metal surface. The images obtained by SEM showed distinct morphologies that varied depending on the metal used, the methodology used, but all had a powdery characteristic, because they are easily torn from the surface. The gravimetric test showed that copper is more sensitive to corrosion than stainless steel. The adhesion test showed that the average copper obtained an increased adhesion, but the sample had adhesion was greater using a steel tape. It is concluded that among the two metal supports chosen, taking into account only the surface treatment and the methodology used, the stainless steel is the best support to be used.
2

Racionalizace technologického procesu elektroerozivního obrábění hloubení / The rationalization of technological process of electrical discharge sinking

Maršálek, Jaroslav January 2009 (has links)
The aim of my work is the rationalization of an elektroerosive process of sinking during the production of a die in a given firm on a sinking machine Agie Hyperspark 3HS. This machine was compared with an existing device in Kovolit Modřice, a publicly held company. And subsequently it was tried several variations of setting. Afterwards it was chosen the most optimal setting for consecutive production of concrete die.
3

Elektroerozivní drátové řezání. / Wire Electrical Discharge Machining.

Bartoš, Pavel January 2011 (has links)
This work deals with analysis of EDM wire cutting technology and aims to assess the current situation and the real possibilities of EDM wire cutting usage in a small engineering company. Furthermore, it addresses manufacturing technology of a model component and the subsequent economic evaluation.
4

Pokrokové metody dělení materiálů se zaměřením na laser, vodní paprsek, elektroerosivní řezání drátem a hloubení / Advanced methods of material division focusing on laser, water jet, electroerosive wire cutting and drilling

JANOVÁ, Jana January 2017 (has links)
In the introductory part of the work carried out the theoretical research of advanced methods of cutting. Chosen methods are laser, water jet and EDM wire cutting and trenching the wire. There is described the history, the principle of separation and classification. The practical part of these methods are discussed in detail with emphasis on their use in practice. The text is supplemented with illustrative examples of products. Finally, the work focuses on the comparison of the described methods. Overall, the work is conceived as a methodological text useful in teaching this topic.
5

Trendy vývoje nástrojů pro výrobu dutin forem / Trend development of tools for production sinuses forms

Fišer, Michal January 2008 (has links)
This thesis descibes questions of tools for production of shape hollows focused especially on milling and electroerosion machining. Here you can find individual tools included their description and characteristics, toolmakers and their news. Here are mentioned methods and contemporary trend of cutting. Here is comparison of several tools in concrete applications. Included is also list of basic types of milling tools clamping. In conclustion there is mentioned further development of tools and their using.
6

Návrh progresivní technologie výroby střižného nástroje. / Projection advanced production technology of shearing tool.

Vejrek, Tomáš January 2010 (has links)
Proposal progressive technology of production shearing tools. Description shearing tools and shear of the process, analysis current technology production shearing tools. Proposition two variant technology production given to dies method conventional and unconventional, elaboration technological progress and programmes on choice NC machinery, their comparison and technical economic evaluation in fine with recommendation for usage practically.

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