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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

The Studying about Major Factors of Manufacture in LED Backlight Module

Chen, Chun-Ho 17 June 2010 (has links)
In the LCD display products source section LED light display product is OK to replace the traditional CCFL light display products, especially in the NB computer and computer monitor are almost over two to three years CCFL products will be completely out of the market. The LCD itself does not glow and need another light source to support it. Backlight module can provide light source to LCD display product. In the early the light source of backlight module is CCFL. But LED light source is going to replace CCFL from 2007. Most of all new developments in the field of the NB computer backlight module changes light source from CCFL to LED. Even the computer monitor light source is starting to use LED too. The development technologies and production quality of the LED backlight module are significant challenges in LED backlight module factory. The purpose of this study was to identify development technologies and production technologies factors of bottlenecks, and finding a solution. And can provide some help to LED backlight module industry terms. This study selects ' 8D process ' to be analysis model. And collect 5 backlight module factories development experience and production status data. Hope these data through 8D analysis process can find the major related factors of development technologies and production technologies. In-depth research, look forward to finding out the production technologies relevant factors oppression ' technical specification ' production. This study is expected to be able to find some effect LED backlight module process yield factor, then apply the stratification out product issues and process issues, this study is intended for process issue do take an in-depth look at the problem and solution, but about product issue will be' design solutions ' way to describe. I believe this research can help LED backlight module industry to reduce production cost and improve the development speed.
2

Recuperação de zinco e índio de monitores de computadores sucateados

Ana Cristina Vieira Zuccheratte 08 March 2013 (has links)
Este trabalho apresenta o estudo de recuperação de índio (In) e zinco (Zn) presentes em telas de monitores de computadores sucateados, por meio de técnicas hidrometalúrgicas. O trabalho foi subdividido em duas partes distintas: dissolução dos metais In e Zn mediante digestão ácida do pó de revestimento da tela de monitores e separação dos metais pela técnica de extração por solventes. Na etapa de dissolução dos metais, investigou-se a influência das seguintes variáveis de processo: tipo de reagente, relação ácido/amostra, tempo de reação e temperatura. Após a otimização dos parâmetros do processo, obteve-se uma dissolução de índio superior a 95% e de Zn superior a 99,5%. Foi obtido um licor contendo 9,8 g/L de zinco, 1,49 g/L de índio e 102 g/L de sulfato, contendo como impureza 0,016 g/L de ferro, e acidez de 2,2 mol/L (pH = 0,34). Após a definição das melhores condições de abertura química, a amostra foi processada para a obtenção do licor para a realização dos experimentos de extração por solventes. Foram realizados experimentos descontínuos de extração por solventes para a verificação da viabilidade técnica e melhores condições de separação dos metais, e um experimento contínuo para o carregamento do solvente. Na etapa de extração, as variáveis de processo investigadas foram: tipo de extratante, pH do licor e tempo de reação. Os experimentos foram realizados na relação volumétrica aquoso/orgânico (A/O) igual a 1 e concentração de extratante de 1,0 mol/L. Os extratantes investigados foram: DEHPA, IONQUEST 801 e CYANEX 272. O estudo das variáveis foi realizado apenas com os dois primeiros extratantes. Os experimentos de reextração foram realizados com HCl e H2SO4, na relação volumétrica de 1:1 e em diferentes concentrações dos ácidos. Os experimentos de bancada indicaram que a separação dos metais pode ser realizada usando DEHPA 1,0 mol/L como extratante, o H2SO4 1,0 mol/L como agente de lavagem, para a reextração dos elementos coextraídos com o índio (principalmente Zn), e HCl 3,0 mol/L para a reextração do In do orgânico carregado. / This work presents the study of recovery of indium (In) and zinc (Zn) present in computer monitor screens by means of hydrometallurgical techniques. This work was divided into two distinct parts: one is the dissolution of the metals In and Zn through acid digestion of the sample and the separation of the metals through solvent extraction technique. In the acid dissolution, the influence of the following process variables was investigated: type of reagent, acid/sample ratio, time of reaction and temperature. Following the optimisation of the parameters of the process, dissolution of indium above 98% and of Zinc over 99.5% was achieved. A liquor containing 9.8 g/L of zinc, 1.49 g/L of indium and 102 g/L of sulphate having as impurity 0.016 g/L of iron, and acidity of 2.2 mol/L (pH = 0.34) was obtained. After the optimization of the chemical opening conditions, the sample were processed in order to obtain the liquor for the solvent extraction experiments. Batch experiments of solvent extraction aiming at verifying the technical viability and best conditions for the separation of the metals and a continuous experiment to load the solvent were carried out. In the extraction phase, the process variables investigated were: type of extractant, pH of the liquor, and reaction time. The experiments were carried out at an aqueous/organic (A/O) volumetric ratio equal 1:1 and concentration of extractant 1.0 mol/L. The extractants investigated were DEHPA, IONQUEST 801 and CYANEX 272. The study of the variables was carried out with DEHPA and IONQUEST 801. The stripping experiments were carried out with HCl and H2SO4, at a volumetric ratio 1 with different acids concentrations. The batch experiments indicated that the separation of the metals In and Zn can be done using DEHPA 1 mol/L as extractant, H2SO4 1 mol/L as scrubbing agent and HCl 3 mol/L as stripping agent. After defining the best conditions for the extraction, scrubbing and stripping steps a continuous experiment was programmed. The McCabe-Thiele diagrams indicated that 3 extractions stages and 7 stripping stages was enough to extract and strip the In from the liquor and the loaded organic respectively. Due to the small amount of the liquor, the continuous experiment contemplate only the extraction and scrubbing steps. The experiment was done in mixer-settler cells, with capacity of 70 mL in the mixer and 250 mL in the settler, in a counter current system. The stripping step was carried out in batches simulating the counter current system. The continuous experiment (extraction and scrubbing steps) were carried out with the use of DEHPA 1.0 mol/L as the extractant agent and a solution of H2SO4 1.0 mol/L as the scrubbing agent in order to remove the impurities extracted. Four extraction stages and 4 stages were employed in each step, using a volumetric ratio A/O equal 5:1 in the extraction and a volumetric ration O/A equal 4:1 in the scrubbing step. A loaded organic containing 7.5 g/L of In and 0.003 g/L of Zn and a raffinad containing 9.4 g/L Zn and less than 0.001 g/L of In were obtained from a liquor containing 9.8 g/L and 1.49 g/L. The content of the metals in the stripped solution were 26.7 g/L de In e 0.001 g/L de Zn.

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