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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

Biogeochemical characterization of metalliferous wastes and potential role of arbuscular mycorrhizae in their phytoremediation

Chaudhry, Tariq M., University of Western Sydney, Faculty of Informatics, Science and Technology January 1999 (has links)
Phytoremediation is an innovative technology employing plants for reclamation of soils that have been polluted by industrial contaminants. While it is frequently slower than traditional physicochemical remediation techniques, there are, however, many significant advantages including simplicity, low cost, improvement of soil structure and microbiological fertility. While various hyperaccumulators have been reported from Europe and the USA, there is a need to identify Australian species. This study reports a number of metal accumulators following a soil and vegetation survey of two metal contaminated sites in New South Wales, the spoil (filtercake) heaps of the BHP (Broken Hill Propriety ) steelworks at Port Kembla and the abandoned mine at Sunny Corner. BHP is the largest manufacturer of steel in Australia. The Port Kembla is the largest single steel manufacturing site. Solid by-products from this site totalled 3.1 million tons in 1988. The Sunny Corner mine site was mainly a silver mine which operated over approximately 100 hectares 1184 to 1922 and produced over 100 tonnes of silver during that period. The soil and water in and around the site is heavily contaminated with metals and is distinctly acidic. It was concluded that Ricinus communis, Sonchus oleraceus, baeckea utilis, Poa labillardieri and Pinus radiata are options for heavy metal phytoremediation of contaminated Australian soils. Arbuscular Mycorrhizal infection (particular with Glomus and Gigaspora strains) should be promoted for optimum growth. / Doctor of Philosophy (PhD)
2

Caracterização de toxicidade de efluentes de usina siderúrgica mediante bioensaios com microorganismos / Characterization of steel mill´s effluents toxicity using bioassays Microtox and Ames

Barreto, José Carlos Nunes 21 July 1995 (has links)
Cubatão, na Baixada Santista ficou caracterizada na década de 70 pelo caos ambiental propiciado pela instalação de dezenas de indústrias de base, sem planejamento territorial urbano adequado, sem estudo de impacto ambiental e com poucos equipamentos de controle de poluição do ar, solo e água. Dentre as indústrias sediadas no pólo industrial de Cubatão, a siderúrgica é responsável pela poluição das águas do estuário santista com a maior carga tóxica e 60por cento de Fenol e 70por cento de Metal Pesado, do total lançado por todas as indústrias do Polo. Este trabalho faz levantamento bibliográfico nacional e internacional sobre poluição hídrica de Siderúrgicas notadamente coquerias e mostra pesquisa de campo realizada em 13 campanhas, com amostragens junto a saída de efluentes no porto da empresa no estuário santista. Os resultados das amostras no ponto responsável pelos efluentes das fábricas de coqueria, laminação, aciaria e altos fornos, indicam toxicidade em 80por cento das campanhas e mutagenicidade de moderada a alta em 75por cento das amostras pesquisadas. Os resultados dos bioensaios utilizados, Microtox e Ames, respectivamente para toxicidade aguda e mutagenicidade, foram comparados aos dos últimos trabalhos realizados na COSIPA em 1986 e 1993, e aos relatórios do órgão controlador, CETESB de 1992 e 1994. Abrem - se discussões sobre os resultados que apontam o particulado presente na amostra como tóxico e mutagênico e induzem à proposta de recirculação e reaproveitamento total à jusante da empresa, de todas águas servidas descartadas no processo, a exemplo de países do 1º Mundo que convivem com a produção do aço / Cubatão, situated in the low lying basin behind the porto f Santos on the coast of the state of São Paulo, Brazil, was notorious during the seventies for the environmental chaos produced by the dozens of basic industries and the lack of adequate urban planning, of studies of the environmental impact caused and with negligible resources for the control of pollution, whether of the air, soil or water. Among the factories located in the industrial park of Cubatão, the steelworks is responsible for the largest toxic contribution as also for 60per cent of the fenol and 70per cent of the heavy metals of the overall total of these substances expelled by the factories of the industrial park. A survey of the literature, both national and international, dealing with the associated coke producing plants, was undertaken and presents field research carried out in the course of 13 campaigns giving the results of samples colleted close to the effluents in the company´s port in the Santos estuay. The results of the bioassays used to assess acute toxicity and mutagenicity, Microtox and Ames respectively, were compared with those found in the last researths undertaken by COSIPA in 1986 and 1993 and with those given in the reports of CETESB, the organ responsible for pollution control, in 1992 and 1994. The results which show that the particles presents in the samples were toxic and mutagenic are discussed and lay the foundation for the proposal that the totality of the water used shoud be returned to above the plant in such away as to permit its constant re use, in accordance with the example given by countries of the first world which have learnt to live with the nead for the production of steel
3

Caracterização de toxicidade de efluentes de usina siderúrgica mediante bioensaios com microorganismos / Characterization of steel mill´s effluents toxicity using bioassays Microtox and Ames

José Carlos Nunes Barreto 21 July 1995 (has links)
Cubatão, na Baixada Santista ficou caracterizada na década de 70 pelo caos ambiental propiciado pela instalação de dezenas de indústrias de base, sem planejamento territorial urbano adequado, sem estudo de impacto ambiental e com poucos equipamentos de controle de poluição do ar, solo e água. Dentre as indústrias sediadas no pólo industrial de Cubatão, a siderúrgica é responsável pela poluição das águas do estuário santista com a maior carga tóxica e 60por cento de Fenol e 70por cento de Metal Pesado, do total lançado por todas as indústrias do Polo. Este trabalho faz levantamento bibliográfico nacional e internacional sobre poluição hídrica de Siderúrgicas notadamente coquerias e mostra pesquisa de campo realizada em 13 campanhas, com amostragens junto a saída de efluentes no porto da empresa no estuário santista. Os resultados das amostras no ponto responsável pelos efluentes das fábricas de coqueria, laminação, aciaria e altos fornos, indicam toxicidade em 80por cento das campanhas e mutagenicidade de moderada a alta em 75por cento das amostras pesquisadas. Os resultados dos bioensaios utilizados, Microtox e Ames, respectivamente para toxicidade aguda e mutagenicidade, foram comparados aos dos últimos trabalhos realizados na COSIPA em 1986 e 1993, e aos relatórios do órgão controlador, CETESB de 1992 e 1994. Abrem - se discussões sobre os resultados que apontam o particulado presente na amostra como tóxico e mutagênico e induzem à proposta de recirculação e reaproveitamento total à jusante da empresa, de todas águas servidas descartadas no processo, a exemplo de países do 1º Mundo que convivem com a produção do aço / Cubatão, situated in the low lying basin behind the porto f Santos on the coast of the state of São Paulo, Brazil, was notorious during the seventies for the environmental chaos produced by the dozens of basic industries and the lack of adequate urban planning, of studies of the environmental impact caused and with negligible resources for the control of pollution, whether of the air, soil or water. Among the factories located in the industrial park of Cubatão, the steelworks is responsible for the largest toxic contribution as also for 60per cent of the fenol and 70per cent of the heavy metals of the overall total of these substances expelled by the factories of the industrial park. A survey of the literature, both national and international, dealing with the associated coke producing plants, was undertaken and presents field research carried out in the course of 13 campaigns giving the results of samples colleted close to the effluents in the company´s port in the Santos estuay. The results of the bioassays used to assess acute toxicity and mutagenicity, Microtox and Ames respectively, were compared with those found in the last researths undertaken by COSIPA in 1986 and 1993 and with those given in the reports of CETESB, the organ responsible for pollution control, in 1992 and 1994. The results which show that the particles presents in the samples were toxic and mutagenic are discussed and lay the foundation for the proposal that the totality of the water used shoud be returned to above the plant in such away as to permit its constant re use, in accordance with the example given by countries of the first world which have learnt to live with the nead for the production of steel
4

Estudo do efeito da adi??o da esc?ria de aciaria no processamento e propriedades finais de telhas cer?micas

R?go, Vilson Ribamar 21 September 2010 (has links)
Made available in DSpace on 2014-12-17T14:07:06Z (GMT). No. of bitstreams: 1 VilsonRR_TESE.pdf: 4774332 bytes, checksum: b653e020c564d2ea65edb56c41828fda (MD5) Previous issue date: 2010-09-21 / This research presents an overview of the addition steelwork dust of ceramic shingles in order to contribute to the utilization use of such residue. The ceramic industry perspective in the Brazilian State of Piau? is quite promising. Unlike other productive sectors, the ceramic industry uses basically natural raw materials. Its final products are, in short, the result of transforming clay compounds. These raw materials are composed primarily of aluminum oxide, silicon, iron, sodium, magnesium, end calcium, among others. It was verified that steelwork dust is composed primarily of these same oxides, so that its incorporation in to structural ceramics is a very reasonable idea. Both clay and steelwork powder were characterized by AG, XRF, XRD, TGA and DTA. In addition, steelwork dust samples containing (0%, 5%, 10%, 15%, 20% and 25%) were extruded and burned at 800?C, 850?C, 900?C and 950?C. Then t echnological tests of linear shrinkage, water uptake, apparent porosity, apparent density and flexural strengthwere carried at. The results showed the possibility of using steelwork powder in ceramic shingles until 15% significant improvement in physical and mechanical properties. This behavior shows the possibility of burning at temperatures lower than 850?C, thus promoting a product final cost reduction / Neste trabalho ? estudado o efeito da adi??o da esc?ria de aciaria em massas cer?micas para ind?strias de cer?mica vermelha, visando contribuir com o aproveitamento desses rejeitos. Foi feito uma avalia??o da sua adi??o ? massa cer?mica para produ??o de telhas. O panorama da ind?stria cer?mica no estado do Piau? ? bastante promissor. Diferente de outros setores produtivos, o setor cer?mico utiliza, basicamente, mat?rias-primas naturais. O seu produto final ?, em suma, o resultado da transforma??o de compostos argilominerais. Essas mat?rias-primas s?o compostas, basicamente, de ?xidos de alum?nio, sil?cio, ferro, s?dio, magn?sio, c?lcio, dentre outros. Verificou-se que a esc?ria de aciaria ? composta principalmente por esses mesmos ?xidos, de forma que sua incorpora??o ? massa de cer?mica estrutural ? uma ideia absolutamente razo?vel. Foram caracterizadas as mat?rias-primas argila e esc?ria de aciaria por AG, FRX, DRX, TGA e DTA. Tamb?m foram conformados por extrus?o e queimados nas temperaturas de 800?C, 850 ?C, 900?C e 950?C corpos-deprova com 0%, 5%, 10%, 15%, 20% e 25% de teor de esc?ria de aciaria. Em seguida, foram realizados ensaios tecnol?gicos de retra??o linear, absor??o de ?gua, porosidade aparente, massa espec?fica aparente e resist?ncia mec?nica ? flex?o. Os resultados mostraram a possibilidade de se utilizar at? 15% de esc?ria de aciaria na massa cer?mica para telhas. At? essa dosagem, melhorias consider?veis nas caracter?sticas f?sicas e mec?nicas avaliadas foram observadas. O estudo tamb?m mostrou a possibilidade de queima em temperaturas mais baixas que 850?C, promovendo, assim, uma redu??o dos custos finais do produto
5

Skivbytesrobotik i tuff miljö : Utvärdering och förslag på förbättringsåtgärder / Robotics for change of abrasives in tough environment : Evaluation and improvement suggestions

Reichenwallner, Christopher, Tegevall, Erik January 2017 (has links)
Examensarbetet har utförts under 10 veckor i uppdrag av Outokumpu Stainless AB via Uppsala universitet. Outokumpus produktion i Avesta tillverkar rostfritt stål, där en del av det producerade stålet slipas för att få en finare yta och minska defekter. I sliphallen finns 8st slipmaskiner som alla måste servas med nya slipskivor när de gamla är nedslipade. Detta utförs av två robotar som automatiskt ska åka ut i sliphallen och byta ut de gamla slipskivorna. Problematiken ligger i dessa robotar, vars automation endast fungerar fullt ut ett fåtal av gångerna. Examensarbetet gick således ut på att utvärdera dessa robotar samt generera förslag på förbättringsåtgärder. En stor del av arbetet fokuserades på analys av den befintliga skivbytesprocessen. Efter att förståelse erhållits för dagens process utfördes undersökningar i syfte att finna de faktorer som orsakar stopp i automationen samt dess konsekvenser. Till sist genererades lösningsförslag vars syften är att öka andelen automatiska byten. De huvudsakliga orsakerna till stoppen i automationen grundar sig i processens utformning, dess krav på precision och att ett flertal komponenter måste harmoniera för att byten ska fungera automatiskt. Bortsett från processens utformning är smuts, slitage, ej anpassad reglering och bristande rutiner faktorer som sätter stopp för automationen. Konsekvenser av problemet är säkerhetsrisker, frustration, tidsförluster för operatörer och ekonomiska förluster. Den instabila skivbytesprocessen påverkar i dagsläget inte nödvändigtvis ledtider på produkterna, men tvingar operatörer att byta slipskivor för tidigt vilket resulterar i outnyttjade slipskivor. Att öka andel automatiska byten är möjligt men kräver mycket arbete. Rutiner är viktigt, särskilt angående linjering av slipmaskinerna, vilket är en förutsättning för att det ska fungera. Även utbyte av slitna komponenter, optimering av reglertekniken och mindre programändringar är lösningar till en ökad andel automatiska byten. För att minska kostnaden för outnyttjade slipskivor krävs det att processen kan utföras snabbare och utan att påverka produktionen. Om företaget ska implementera en alternativ lösning är det viktigt att denna lösning inte kräver att operatörer behöver befinna sig i sliphallen. Detta grundar sig i säkerhetsrisker och minskad produktionskapacitet. Lösningen bör vara adaptiv för att ej behöva förlita sig på linjerade maskiner eller snäva toleranser. / This thesis in Mechanical engineering has been performed at the stainless steel manufacturer Outokumpu Stainless AB, through Uppsala University. At the company's production site some of the produced steel slabs are going through hot grinding in order to get the required surface finish, depending on the customer's demand on quality. There are 8 grinding machines in the grinding station, each of those needs to be provided with new abrasives when the old ones get to worn out. Two robots are installed to execute the abrasives change operation automatically, where each robot maintains 4 grinding machines, two coarse and two fine. This changing process is currently working fully automatically around one percent of the times which constitutes a problem. The thesis is about evaluation and improvement suggestions of this process, where the proportion of succeeded automatically replaced abrasives is in focus. A big part of the work has been based on analysing the existing process in purpose of understanding it fully. After enough knowledge about the process was achieved, investigations about the deficiencies of the process were conducted. Finally improvement suggestions were generated. The main cause of the automation failure is based on the process design and its precision requirements. The environment is tough and the forces are big which affects the process negatively. In addition there are a several components that need to harmonize in order for the abrasives replacement to work properly. Aside from the design of the process other critical factors are dust, component wear, deficient adapted regulation and lacking of alignment routines. Consequences of the failed automatically abrasive replaces are reduced safety, frustration among operators, time loss and economical losses. When the automation stops, the operators have to manually correct the errors alongside the grinding machines in the grinding area. The unstable processes does not necessarily affect the value-adding lead time but forces operators to change the abrasives too early which results in losses in form of non-fully utilized abrasives. Increasing the proportion of automatically fulfilled replaced abrasives is possible but requires much work. Routines are important, especially with alignment of the grinding machines which is a prerequisite for the process to succeed. Replacing of wear damaged components, optimizing the regulation and smaller programming changes are also solutions that contribute to an increasing proportion. To minimize the cost of unutilized abrasives the process is required to perform faster and without interfering with the production.   If the company wants to implement a different solution in form of an investment it is important that the solution does not require operators to be inside the grinding area. This is based on safety issues, also the risk of interrupting the production and creating a bottleneck, which can be crucial under more demanding periods. The solution should be a faster, more adaptive system and should not have to rely on alignment and narrow tolerances.
6

A dinâmica socioespacial recente do município de Açailândia-MA / The recent socio-spatial dynamics of the municipality of Açailândia-MA

Belfort, Gilson dos Santos 14 June 2016 (has links)
Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-05-24T18:30:55Z No. of bitstreams: 1 GilsonSantosBelfort.pdf: 3480064 bytes, checksum: bc02e50ed9344a4c0797917758fe305a (MD5) / Made available in DSpace on 2017-05-24T18:30:55Z (GMT). No. of bitstreams: 1 GilsonSantosBelfort.pdf: 3480064 bytes, checksum: bc02e50ed9344a4c0797917758fe305a (MD5) Previous issue date: 2016-06-14 / This dissertational work is to analyze the recent socio-spatial dynamics of the municipality of Açailândia (MA), which was separated from the city of Imperatriz in 1981, and that in a short time of political emancipation, became one of the largest economic centers of the State of Maranhão, highlighting mainly in agriculture, with the highlight the cattle and the steel industry. In the construction of the dissertation, he tried to structure the same, taking into account the theoretical study of the categories territory and territoriality on the perspective of Economic Geography, from there we tried to understand the process of formation of the space of the city of Açailândia, then leaving for an analysis of the economic dynamics of the city, from the 1990s, when large enterprises were already actively working. Wanted also observe and analyze the impact of steel enterprises in the economic of the municipality and at the last moment to turn the attention to the study and analysis of the recent socio-spatial dynamics Açailândia. / O presente trabalho dissertativo tem por objetivo analisar a Dinâmica Socioespacial recente do município de Açailândia (MA), que foi desmembrado da cidade de Imperatriz no ano de 1981, e que em pouco tempo de emancipação politica, tornou-se um dos maiores polos econômicos do Estado do Maranhão, destacando-se principalmente no setor siderúrgico e na agropecuária, tendo como ênfase a bovinocultura. Na construção da dissertação, procurou-se estruturar a mesma, levando em consideração o estudo teórico das categorias território e territorialidade sobre a perspectiva da Geografia Econômica, onde se buscou entender o processo de formação do espaço geográfico do município de Açailândia, partindo então para uma análise da dinâmica socioeconômica do município, a partir da década de 1990, quando os empreendimentos siderúrgicos já estavam funcionando ativamente, e a agropecuária estava em evidencia nessa porção territorial do oeste maranhense. Procura-se ainda nesta pesquisa observar e analisar os impactos dos empreendimentos siderúrgicos na econômica do município, e no último momento a atenção volta-se para o estudo e análises da recente dinâmica socioespacial de Açailândia.

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