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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.
31

Estimativa da geração de sucata de bateria de chumbo-ácido como ferramenta de gestão de resíduos eletroeletrônicos

CABRAL NETO, João Pinto 20 April 2016 (has links)
Submitted by Irene Nascimento (irene.kessia@ufpe.br) on 2016-07-18T18:34:17Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação_João Cabral_PPGECAM.pdf: 1516222 bytes, checksum: 1dfca4d9fc8997484046f1a4b3ca8fde (MD5) / Made available in DSpace on 2016-07-18T18:34:17Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação_João Cabral_PPGECAM.pdf: 1516222 bytes, checksum: 1dfca4d9fc8997484046f1a4b3ca8fde (MD5) Previous issue date: 2016-04-20 / O trabalho versa sobre a problemática do crescimento da geração de um tipo de resíduo eletroeletrônico: a bateria de chumbo-ácido. Os resíduos de equipamentos eletroeletrônicos são objeto de diversas pesquisas mundo afora, não somente devido ao seu crescimento acelerado, mas também porque muitos são fontes de materiais perigosos ao meio ambiente e à saúde pública. Nesse contexto, estão as baterias automotivas, cuja produção está vinculada à fabricação de carros e a sua própria vida útil. A maior parte das baterias comercializadas no Brasil são do tipo chumbo-ácido, cujos resíduos contêm grandes quantidades de chumbo que poderiam ser aproveitadas. Dessa maneira, esse trabalho teve como objetivo principal a construção de um modelo matemático para a projeção futura de sucatas de bateria, considerando fatores tais como mercado de venda de automóveis (carro passeio) e vida útil das baterias. Para tanto, foi construída uma série temporal, a partir da análise histórica de venda de veículos, composta por dados de 10 anos. Com o levantamento das informações, foram utilizadas ferramentas de análise de séries temporais para a identificação da existência de características como tendência e/ou sazonalidade na série de dados. Comprovada a existência de tais características, foi realizada a suavização da série e, posteriormente, a proposição do método estatístico de previsibilidade, observando as hipóteses de utilização de médias móveis, suavizações simples, dupla ou tripla. O modelo matemático deste estudo poderá tornar possível o planejamento adequado, por parte de empresas e governo, quanto à política de gerenciamento dos resíduos de acumuladores, considerando a logística reversa, como objetivo a ser alcançado. / The paper aims to introduce the issue from the growing generation of a type of electronic waste: a lead-acid battery. Waste of electrical and electronic equipment are the subject of several studies around the world, not only because of its rapid growth, but also because many are sources of hazardous materials to the environment and public health. Most batteries sold in Brazil are the lead-acid type, whose waste contains large amounts of lead that could be harnessed. Thus, this work aims to build a mathematical model for the future projection of battery scrap, considering factors such as car sales market (passenger car) and battery life. To this end, a time series will be built from the historical analysis of car sales, comprising data for 10 years. From the survey information will be used time series analysis tools for identifying the existence of trend and/or seasonality. If proven such characteristics, the smoothing of the series will be held and subsequently proposing the statistical method of predictability, noting the chances of using moving averages, simple smoothing, double or triple. The mathematical model of this study will make possible the proper planning on the part of business and government, as the management policy of waste batteries, considering the reverse logistics as a goal to be achieved.
32

Nulové opravy ve výrobním procesu / Zero Rework in Production

Děcký, Marek January 2008 (has links)
This diploma thesis handles with problems of reducing the production costs. The costs are connected with produce of scraps on Opel Delta project, where is the zero rework process booted. This work contains analysis of scraps for several periods and etablished actions to decrease inception of scraps.
33

Optimalizace výrobního procesu / Optimization of production process

Olšák, Jiří January 2012 (has links)
The aim of this thesis is to reduce the cost of poor quality in the chosen production process. Specifically I focused on the winding lines at the production of rotors, which are components of electronic brake systems (EBS) and heating and ventilation systems of cars. The thesis was worked out in accordance with an announced Six Sigma project in the company. I also dealt with the Six Sigma strategy in the theoretical part. The chosen tools are applied afterwards in the practical part, especially in define, measure and analyse phases. The output of this thesis is an analysis of all possible causes of high scrap ratio in the stated production process. I also proposed to adopt measures for cutting the cost of poor quality in the chosen production process.
34

Drapákový manipulátor / Grab manipulator

Mlčoch, Petr January 2014 (has links)
The subject of this thesis is a design of an aluminium scrap handling device. This device works in a roofed-over hall and it is stationary. Introduction to this thesis brings the usual machines used for handling of metal waste as alternatives to this device, and the reasons why these do not fulfil the customer’s demands. The work contains kinematics lay-out and force analysis. The shape and dimensions of the design derive from these chapters. The following part deals with the description of the major parts including the hydraulic system which provides all the working movements of the device. The conclusion comprises of the retroactive check of the device’s tipping load, calculation of the rollover resistance, stress analysis of the boom and the stick. The work includes the general assembly drawing and subassembly drawings of the boom and the stick.
35

Exhaust gas emissions from a prototype scrap tire incinerator/wastewater treatment plant sludge dryer

Tober, M. Lyn 29 August 2008 (has links)
In conjunction with Atlantic Pacific Engineering and the Henry County Public Service Authority, Virginia Tech’s Environmental Engineering program measured the emissions from an experimental scrap tire incinerator/wastewater treatment plant sludge dryer. This report recounts the techniques used and the results obtained during this testing. The Virginia Department of Environmental Quality supplied a list of pollutants of permitting interest which included a variety of criteria pollutants, toxics, and metals. Sampling for all the listed compounds required adherence to EPA Methods 5, 201A, 29, 0010, 0011, 0030, 6, 7D, 26A, and 18. Emissions testing transpired during the incinerator’s 72-hour test burn: 0800 October 30th to 0800 November 2nd, 1995. Due to time constraints, only part of one nonpotable water sampling series was completed rather than the proposed duplicate testing using both drying agents: nonpotable water and sludge. High particulate (57 lb/hr) and metal (21.4 lb/hr total) emissions indicate a fairly significant amount of air pollution control equipment will be necessary for a commercial plant. Both nitrogen oxides and sulfur dioxide had low emission rates: 1.73 lb/hr and 0.64 lb/hr, respectively, due to the nonpotable water spray acting as a fairly efficient scrubber removing a great deal of nitrogen oxides, sulfur dioxide, and some metals. Because of sample analysis preparation problems, no organics results were obtained. Commercial development of this incinerator will have to include a sizable quantity of air pollution control equipment: a $5 million plant will need approximately $1 million worth of control equipment. / Master of Science
36

Mesclas de gÃneros no Orkut: o caso do scrap / Mixing genres in Orkut: the case of scrap.

Vicente de Lima Neto 02 December 2009 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / O objetivo desta pesquisa foi descrever as relaÃÃes intergenÃricas constitutivas do scrap do Orkut. Nossa hipÃtese foi que o fenÃmeno da intergenericidade, analisado pela LinguÃstica de Texto, nÃo dava conta de algumas peculiaridades que aconteciam no scrap, o qual permite em sua constituiÃÃo misturas de gÃneros de naturezas distintas. Para o alcance deste objetivo, apoiamo-nos na base epistemolÃgica das formulaÃÃes filosÃficas de Bakhtin para o conceito de linguagem e no aparato teÃrico da LinguÃstica de Texto e da SociorretÃrica para compreender o funcionamento dos gÃneros numa dada cultura. Num primeiro momento da dissertaÃÃo, fizemos uma discussÃo sobre o que entendemos por gÃnero e por gÃneros digitais e discutimos as categorias que nos ajudaram a analisar os dados, a saber, a convergÃncia de mÃdias, a hipertextualidade e a transmutaÃÃo. Num segundo momento, procedemos à anÃlise empÃrica de scraps a qual evidenciou existirem tipos distintos de mesclas de gÃneros no Orkut, alÃm da intergenericidade. Para a construÃÃo dos dados, reportamo-nos Ãs bases da pesquisa qualitativo-interpretativa e fizemos uma investigaÃÃo durante dois anos no site de relacionamentos Orkut, em busca de scraps que apresentavam em sua constituiÃÃo traÃos de mais de dois gÃneros. Desta anÃlise, foi possÃvel verificar que o scrap tornou-se um dos eventos comunicativos de constituiÃÃo das mais complexas na Internet, jà que permite mesclas de gÃneros de pelo menos trÃs formas distintas: mescla por intergenericidade prototÃpica; mescla por co-ocorrÃncia de gÃneros e mescla por gÃneros casualmente ocorrentes. Isso permitiu-nos afirmar a intergenericidade, da forma como estava sendo estudada, nÃo dava conta de todos os tipos de misturas de gÃneros que se constroem na Web e fora dela, portanto à um conceito que mereceu ser repensado, de forma que nÃo envolvesse, numa relaÃÃo entre gÃneros, somente forma e funÃÃo de dois gÃneros distintos.
37

Improved mapping of steel recycling from an industrial perspective

Gauffin, Alicia January 2015 (has links)
The results from this study show that it is possible to obtain data series on the steel scrap collection based on mass balance model on the crude steel production figures by steelmaking reactor type and additional knowledge on process metallurgy as well as information on inputs and outputs into the reactors with an area correlation coefficient of 0,91 compared to data obtained from trade statistics. Furthermore, the study shows that based on a new method it is possible to calculate the time duration of mass flows on a continuous basis. Furthermore, two complementary statistical dynamic material flow models that can be used to calculate the societal recycling rates of steel was constructed. These statistical models contribute to a standardized way of obtaining consistent results. The new models are able to segregate the non-recirculated amounts of steel into the hibernating steel stock available for future collection from the amounts of losses based on statistics. The results show that it is possible to calculate the amounts of steel scrap available for steelmaking at a given point in time. In addition, based on the new models it is possible to calculate recycling trends in society. Also, the models are able to calculate robust forecasts on the long-term availability of steel scrap, and test if forecast demand of steel scrap exceeds a full recovery. This due to that the steel scrap generation is a function of the collection rate of steel scrap. Also, a method for obtaining representative samplings on the alloy content in steel scrap called random sampling analysis (RSA) was developed. The results from the RSA show that it is possible to optimize the recovery of valuable elements in the production process of steelmaking based on the information on the composition of steel scrap. / <p>QC 20151020</p>
38

A critical analysis of management and disposal options of plastic waste in Hong Kong

Ho, Yuet-wah., 何月華. January 2000 (has links)
published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management
39

Pre-treatment processing of household plastic packaging waste

Blackstock, Ross January 2016 (has links)
A research report submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, in fulfilment of the requirements for the degree of Masters in Engineering. Johannesburg, 2016 / The purpose of this investigation was to investigate whether or not it would be possible to separate blow moulded and injection moulded waste plastics using two techniques; air classification and ballistic separation. Air classification and ballistic separation are two techniques that separate different types of material according to size, shape and density. Previous research, together with new measurements, has suggested that blow mould plastics tend to be thinner in terms of wall thickness than injection moulded plastics meaning that air classification could be used to separate each type of plastic. The material used for the study was supplied by a Romanian recycler and was a mixture of High Density Polyethylene and polypropylene. Two additional samples, one Polyethylene rich and the other polypropylene rich, were also included in the research. The first part of the study involved measuring different characteristics of the material to determine how to go about performing the different air classification experiments. The second part of the study focused on separating the different material samples using different air classifier systems and a ballistic separation system. The third part of the study focused on processing the samples from part 2 (air classification) into test specimens for further mechanical and melt flow property measurements. After measuring the mechanical and melt flow properties of the different samples it was found that air classification did not substantially improve the mechanical or melt flow properties of the material. The study did, however, show that there is a strong correlation between polymer type and melt flow properties. High Density polypropylene is generally used for blow mould applications whereas polypropylene is generally used for injection mould applications. Separating the material according to polymer type therefore means that the material is, to an extent, also sorted according to melt flow properties. / MT2017
40

Desenvolvimento de métodos alternativos ao fire assay para a determinação Ag, Au e Pd em sucata eletrônica por ICP-OES e WDSXRF / Development of alternative methods to Fire Assay for the determination of Ag, Au and Pd in electronic scrap by ICP-OES and WDSXRF

Margatho, Vinícius Salles 15 December 2017 (has links)
As sucatas eletrônicas são hoje consideradas como matéria prima de alto valor agregado e economicamente viável, devido à presença de metais preciosos (e.g. prata, ouro, platina e paládio) em sua composição. Em geral, a comercialização é baseada no teor de metais preciosos e cobre, sendo assim, as análises químicas desempenham papel fundamental nesse ambiente de negócios. O método mais empregado para esse tipo de análise, considerado padrão é o Fire Assay, que consiste na extração dos analitos da matriz tornando determinação final praticamente livre de interferências. Entretanto o Fire Assay é um método susceptível a erros sistemáticos devido ao grande número de etapas, lento, caro e ambientalmente insustentável devido à quantidade de reagentes utilizados e resíduos gerados (e.g. chumbo). Diante dessas importantes desvantagens, o desenvolvimento de métodos que apresentem exatidão, precisão, boa frequência analítica, custo e que gere poucos resíduos se tornam necessários para a melhoria do controle de qualidade desses materiais. Sendo assim, o objetivo dessa pesquisa foi o desenvolvimento de método para a determinação simultânea de Au, Ag e Pd por espectrometria de emissão óptica com plasma indutivamente acoplado (ICP OES) e espectroscopia de fluorescência de raios-x por comprimento de ondas (WDSXRF), usando diferentes estratégias de preparação de amostras. As sucatas eletrônicas se caracterizam por serem heterogêneas, além disso, o material possui grande quantidade de metais como Al, Cu e Fe na composição fazendo com que a comunição seja um elemento chave no método e determinante da frequência analítica. Considerando esta dificuldade as amostras foram moídas em moinho oscilatório de discos de em diferentes tempos a fim de se investigar a influencia do tamanho de partículas para estudo de representatividade e precisão além da influencia do tamanho de partículas nas determinações por WDSXRF devido ao efeito sombra. Para os analises por WDSXRF as amostras com 40 minutos de moagem e preparadas com fusão com ferro e enxofre demonstraram boas correlações quando comprados ao Fire Assay. As dissoluções das amostras para analises em ICP OES ocorreu em duas etapas, a 1&#170; com HNO3 (aquecimento em chapa) para evitar passivação do ouro e a 2&#170; com 10 ml de água régia, usando o programa do forno de micro-ondas, com rampa de 160 °C a 210 °C (30 min). Foi observado que o excesso de Cl- formou complexos que inibiram perdas de Ag+ pro precipitação. As soluções finais foram analisadas no ICP OES e as concentrações obtidas foram comparadas ao método de Fire Assay. O método proposto mostrou boa correção para todos os elementos ao método padrão. A reprodutibilidade para Au foi de 4,1% (n=15 amostras) e a recuperação média comparada ao método padrão foi de 102%. Com base nos resultados obtidos pode-se dizer que o método proposto é comparável ao Fire Assay quanto à precisão e limites de detecção, apresentando melhores respostas quanto à frequência analítica, custo e geração de resíduos / Electronic scraps are today considered as raw material of high added value and economically viable, due to the presence of precious metals (e.g. silver, gold, platinum and palladium) in your composition. In general, the marketing is based on the content of precious metals and copper, therefore, chemical analysis plays a key role in this business environment. The method employed for this kind of analysis, considered standard, is the Fire Assay, which consists of the extraction of analytes in the array, making final determination virtually free of interference. However the Fire Assay is a method susceptible to systematic errors due to the large number of steps, slow, expensive and environmentally unsustainable due to the amount of reagents used and waste generated (e.g. lead). On these important disadvantages, the development of methods which have accuracy, precision, good analytical cost and frequency that generate few residues become necessary for the improvement of the quality control of these materials. Therefore, the objective of this research was the development of method for the simultaneous determination of Au, Ag and Pd by optical emission spectrometry with inductively coupled plasma (ICP OES) and fluorescence spectroscopy for x-ray wavelengths (WDSXRF), using different sampling strategies. Electronic scraps are characterized for being heterogeneous, in addition, the material possesses large amount of metals such as Al, Cu and Fe in the composition so that the communication is a key element in determining the frequency and analytical method. Considering this difficulty the samples were ground into oscillatory grinder discs at different times in order to investigate the influence of the particle size for study of representativeness and accuracy beyond the influence of the particle size determination by WDSXRF due to the shadow effect. For the analysis by WDSXRF samples with 40 minutes of grinding and prepared with merger with iron and sulfur showed good correlations when purchased the Fire Assay. The dissolutions of the samples for analysis in ICP-OES occurred in two steps, first with HNO3 (heating plate) to avoid gold passivation and the 2nd with 10 ml of aqua regia, by using the microwave oven, with 160 °C ramp to 210 °C (30 min). It was observed that the excess of Cl-formed complex that inhibit loss of Ag+ by precipitation. The final solutions were analysed at the ICP OES and the concentrations obtained were compared to the method of Fire Assay. The proposed method showed good fix for all elements to the standard method. Reproducibility for Au was 4.1% (n = 15 samples) and the average recovery compared to the standard method was 102%. Based on the results obtained can be said that the proposed method is comparable to the Fire Assay for accuracy and limits of detection, showing best answers regarding the analytical frequency, cost and waste generation.

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