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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

Catalytic reduction of nitric oxide by carbon monoxide or hydrogen over a Monel metal catalyst

Crawford, Ian Stewart. January 1987 (has links) (PDF)
Includes summary. Includes bibliographies.
12

The determination of a strategy for the implementation of learnerships in the catalytic converter canning industry in the Eastern Cape

Heather, Keith Buxmann January 2002 (has links)
The Eastern Cape Region, once had sufficient job seekers with automotive component manufacturing skills and experience. Indications are that this pool has been desiccated. The draining of skills out of the area is starting to affect growth potential and competitiveness in the industry in the area. In 1998, the Skills Development Act was passed to implement the National Skills Development Plan, and to encourage employers to train personnel. The strategy promotes a three faceted approach to encourage the development of skills; Workplace Skills Development Plans, Learnerships and Sector Specific Initiatives. This study will focus on the implementation of learnerships in the Catalytic Converter Canning Industry. The aim of this research is to verify the skills shortages; identify which skills are required by the Catalytic Converter Canning Industry in the Eastern Cape and propose a strategy of addressing these needs by means of learnerships. By studying the Legislation supporting the National Skills Development Plan, conducting a literature study, and interviewing knowledgeable people in the industry, the skills requirements of the industry were identified. Thereafter, a questionnaire was drawn up and completed together with representatives from Eberspächer South Africa, Faurecia Exhaust Systems South Africa, Precision Exhaust Systems and Tenneco Automotive South Africa, the active manufacturers of catalytic converters, for OEM’s worldwide, who are based in the Eastern Cape Region. The empirical study confirmed the findings of the research and skills deficiencies were identified. In conclusion, a strategy is proposed whereby the Catalytic Converter Canning Industry could address the skills shortage by the implementation and development of learnerships.
13

Exploring Neoteric Solvent Extractants: Applications in the Removal of Sorbates From Solid Surfaces and Regeneration of Automotive Catalytic Converters

Subramanian, Bhargavi 03 July 2007 (has links)
No description available.
14

An electrochemical study of the oxidation of platinum employing ozone as oxidant and chloride as complexing agent / by B.M.S. Mogwase.

Mogwase, Boitumelo Mmamopedi Sarah January 2012 (has links)
Motor car exhaust catalysts are some of the most important users of platinum, and much attention is given to the recycling of scrap platinum from spent exhaust systems. The dissolution of platinum from waste exhausts was previously only possible by pyrometallurgical processes or by the use of aggressive chemicals, such as aqua regia and cyanide, all of which, however, cause pollution problems. Recently the potential for the development of hydrometallurgical processes was identified. These processes are more efficient and more environmentally friendly than traditional processes. It was the aim of this study to investigate the oxidation of platinum with ozone as oxidizing agent in the presence of chloride as complexing agent. The influence of various factors, such as chloride ion concentration, pH and temperature were studied thermodynamically and electrochemically in order to achieve efficient leaching. The thermodynamic investigation, leading to the construction of Pourbaix diagrams of platinum in the presence of chloride, confirmed the possibility of the formation of stable aqueous complexes, as well as platinum oxides. From the electrochemical results obtained it can be concluded that ozone may be useful as an oxidizing agent, but according to the leaching results obtained, ozone holds few benefits compared to aqua regia and cyanide, although they still present some environmental challenges. The relatively low percentages of recovery obtained with leaching may be attributed to the rapid decomposition of ozone, which is affected by several factors, such as temperature, pH, initial concentration of ozone, ionic strength and stirring rate. Further optimisation of these factors can possibly prove ozone to be a useful oxidizing agent for the recovery of platinum. / Thesis (MSc (Chemistry))--North-West University, Potchefstroom Campus, 2013.
15

An electrochemical study of the oxidation of platinum employing ozone as oxidant and chloride as complexing agent / by B.M.S. Mogwase.

Mogwase, Boitumelo Mmamopedi Sarah January 2012 (has links)
Motor car exhaust catalysts are some of the most important users of platinum, and much attention is given to the recycling of scrap platinum from spent exhaust systems. The dissolution of platinum from waste exhausts was previously only possible by pyrometallurgical processes or by the use of aggressive chemicals, such as aqua regia and cyanide, all of which, however, cause pollution problems. Recently the potential for the development of hydrometallurgical processes was identified. These processes are more efficient and more environmentally friendly than traditional processes. It was the aim of this study to investigate the oxidation of platinum with ozone as oxidizing agent in the presence of chloride as complexing agent. The influence of various factors, such as chloride ion concentration, pH and temperature were studied thermodynamically and electrochemically in order to achieve efficient leaching. The thermodynamic investigation, leading to the construction of Pourbaix diagrams of platinum in the presence of chloride, confirmed the possibility of the formation of stable aqueous complexes, as well as platinum oxides. From the electrochemical results obtained it can be concluded that ozone may be useful as an oxidizing agent, but according to the leaching results obtained, ozone holds few benefits compared to aqua regia and cyanide, although they still present some environmental challenges. The relatively low percentages of recovery obtained with leaching may be attributed to the rapid decomposition of ozone, which is affected by several factors, such as temperature, pH, initial concentration of ozone, ionic strength and stirring rate. Further optimisation of these factors can possibly prove ozone to be a useful oxidizing agent for the recovery of platinum. / Thesis (MSc (Chemistry))--North-West University, Potchefstroom Campus, 2013.
16

Elementos do grupo da platina (Pt, Pd e Rh) emitidos por conversores cataliticos de automoveis: um estudo realizado em solos localizados as margens da Rodovia dos Bandeirantes no Estado de Sao Paulo

MORCELLI, CLAUDIA P.R. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:49:39Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:03:11Z (GMT). No. of bitstreams: 1 09987.pdf: 6803672 bytes, checksum: c070bf0956c20ddeb4d6cb89d8d1535c (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP / FAPESP:00/02118-9
17

Elementos do grupo da platina (Pt, Pd e Rh) emitidos por conversores cataliticos de automoveis: um estudo realizado em solos localizados as margens da Rodovia dos Bandeirantes no Estado de Sao Paulo

MORCELLI, CLAUDIA P.R. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:49:39Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:03:11Z (GMT). No. of bitstreams: 1 09987.pdf: 6803672 bytes, checksum: c070bf0956c20ddeb4d6cb89d8d1535c (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP / FAPESP:00/02118-9
18

An analysis of the performance of a South African stainless steel manufacturer in localising the demand for corrosion resistant steels within the Eastern Cape catalytic converter industry

Soiné, Robert Paul January 2004 (has links)
Commercial decisions are been made with respect to the competitive advantage of manufacturing catalytic converters in South Africa. This thesis identifies those factors relating to the sourcing of stainless steel and the impact it has of securing future business in a competitive environment. The catalytic converter industry requires the support of a stainless steel plant that provides high quality products at a competitive price, while keeping abreast with international developments.
19

Rozpouštěcí charakteristiky platinových kovů z automobilových katalyzátorů. / Leaching characterization of platinum group elements from automotive catalytic converters

Štědrý, Robin January 2011 (has links)
The distribution of platinum group elements and increase of thein emissions in the environment are mostly related to the use of automobile catalyst. The antropogenic emissions of these noble metals accumulate aloung the roads. The methods such as ICP-OES and XRD were used for determinativ of phase and elemental composition of these samples. The matrix of the gasoline catalyst is composed of Al, Ce oxides with Pt-Pd-Rh coatings. Matrix of diesel catalyst is composed of cordierite with Pt coatings. ICP-MS was used for determination Pt, Pd and Rh. Before the analysis was performed such as pre-concetration fire assay fusion into a NiS button. The leaching characterization of Pt, Pd and Rh was examined during kinetic batch experiments in sodium chloride (1g/l, NaCl), 20 mM Na2P4O7 (NaPyr), fulvic acid (FK, DOC 50 mg/L) and 20 mM citric acid . The results show, that the dissolution of Pt and Pd is the fastest in citric acid and sodium pyrophosphate. Sodium chloride in the concentrations employed, which could be derived from melt waters formed during winter road treatment, does not have a substantiv impal on the speciation and mobilization of Pt and Pd. Organic acid does not have significantly impct on the release of Pt and Pd to the solution. The calculated normalized bulk released NRi values in the range 0,16...
20

Análises experimental, teórica e computacional do escoamento dos gases de exaustão no conversor catalítico platina/paládio instalado em um motor de combustão interna a etanol / Experimental, theoretical, and computational analysis of exhaust gases flow in catalytic converter platinum-palladium of internal combustion engine burning ethanol

Martins, Keyll Carlos Ribeiro 29 June 2006 (has links)
O trabalho consiste em análises experimental, teórica e computacional do escoamento dos gases de exaustão através de um conversor catalítico platina-paládio, instalado num motor de combustão interna movido a etanol. Foram realizados ensaios dinanométricos no motor para análise das medidas experimentais no sistema de exaustão e para aquisição de valores das propriedades termodinâmicas, de transporte e de concentrações químicas, os quais serviram de dados iniciais para a simulação computacional desenvolvida com a utilização dos softwares CFX e MFIX. Os programas resolvem um conjunto de equações conservativas que permitem a análise da variação da pressão, temperatura, velocidade e composição química dos gases de escape ao longo do suporte monolítico. Além de avaliar a formação e os níveis das emissões provenientes da combustão da mistura ar-combustível. A eficiência catalítica no primeiro suporte do conversor foi de 11% THC, 100% NOx e 20% CO. Foi verificada uma diferença de 1,23% entre a velocidade média experimental e a simulada. Modelos matemáticos foram aplicados no estudo da perda de carga no conversor catalítico e na relação difusão-reação do consumo e formação das espécies químicas. / The thesis describes computational, experimental, and theoretical analysis of the exhaust gases flow through a Pt/Pd catalytic converter installed on internal combustion engine burning ethanol. The obtained values related to energy properties and mass transport in experimental tests is the base of initial values for development of the computational simulation by using CFX and MFIX software. The programs solves a group of conservative equations that allow to analysis of variation such as pressure, temperature, and also, velocity of exhausting gases along the monolithic support, moreover to evaluate the formation of gases and its emission levels on the incoming air-fuel mixture combustion and its respective chemical reactions of oxidation. The catalytic efficiency through the first monolith of the converter were about of 11% THC, 100% NOx e 20% CO. It was verified also a small difference of 1,2 % between the experimental and the simulated average velocity. In addition mathematical models were applied on the study of the load loss in catalytic converter, diffusion-reaction of the consumption and also formation of chemical species.

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