• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 348
  • 140
  • 50
  • 49
  • 21
  • 9
  • 9
  • 9
  • 9
  • 9
  • 9
  • 6
  • 6
  • 6
  • 5
  • Tagged with
  • 841
  • 292
  • 104
  • 99
  • 83
  • 74
  • 73
  • 67
  • 58
  • 55
  • 51
  • 51
  • 50
  • 45
  • 44
  • 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.
81

Novel fabrication techniques for solid oxide fuel cells

Payne, Clare Elizabeth Ann January 1996 (has links)
No description available.
82

Some aspects of trace analysis of metals

Dangolle, Champa D. P. January 1996 (has links)
No description available.
83

Pitch Production Using Solvent Extraction of Coal: Suitability as Carbon Anode Precursor

Mohammad Ali Pour, Mehdi 11 1900 (has links)
Albertan coal has been used to produce extracts as precursor for production of anode coke. Coal extractability was studied using digestion with Tetralin in a 500 ml reactor. Different operating conditions were tried and optimum conditions were chosen for runs with coal-derived solvents. Extracts from runs with coal-derived solvents and their hydrotreated versions were distilled and heat treated to produce pitches as coke precursors. Coking experiments were performed using a molten salt bath furnace. Coal, solvents, pitches and cokes were characterized to study the effects of process chemistry on coke anisotropy. Coke anisotropy was studied using image analysis of polarized light optical micrographs and x-ray diffraction. Aromaticity of the pitch was found to be the key parameter controlling coke anisotropy. Solvent was found to be the most important factor contributing to pitch aromaticity. Heat treated products of high aromaticity yield the highest coke conversion and anisotropy. / Chemical Engineering
84

Coal pyrolysis in a fixed bed reactor

Gonenc, Zubeyde Sermin January 1989 (has links)
No description available.
85

Removal of cadmium from wet process phosphoric acid by cation exchange

Booker, Nicholas Anthony January 1989 (has links)
No description available.
86

Estudo preliminar do fracionamento de terras raras medias e pesadas em grupos com extracao por solventes

SOARES, PAULO S.M. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:37:40Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:00:21Z (GMT). No. of bitstreams: 1 05345.pdf: 9869797 bytes, checksum: 233848268ca6b451d04e82fb4874216e (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
87

Estudo para a extracao de uranio em acido fosforico comercial

NOGUEIRA, ANGELA C.R. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:31:52Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:01:09Z (GMT). No. of bitstreams: 1 02245.pdf: 2619284 bytes, checksum: 920d3ab52801f80334d14ea5aa1bf92b (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
88

Estudo da precipitacao continua de diuranato de amonio para producao de oxido de uranio (IV) ceramico

ARAUJO, JOSE A. de 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:23:09Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:03:28Z (GMT). No. of bitstreams: 1 00458.pdf: 3328296 bytes, checksum: d5c7186d59620ba04c5e89553bd39c20 (MD5) / Dissertacao (Mestrado) / IEA/D / Escola Politecnica, Universidade de Sao Paulo - POLI/USP
89

Effect of process variables on the kinetic and thermodynamic parameters of platinum solvent extraction by cyanex 921

Kumwimba, Ghislain Mutamba January 2012 (has links)
Thesis(MTech( Engineering))--Cape Peninsula University of Technology, 2012 / Platinum is a precious metal which may be processed under acidic conditions. Accordingly, the extraction of platinum from an acidic chloride media is of immense practical importance. In this study, the extraction of platinum was investigated in a Pt(IV)-HCl-Cyanex 921 matrix in order to establish the effect of temperature, extractant concentration, pH and the initial platinum concentration which had been used in the evaluated solvent extraction (SX) process. The extractant phase contained a mixture of Cyanex 921 and kerosene. In addition, the extraction mechanism of platinum, and the extracted species, are also described in the study, including the determination of the following: extraction ratio, extractant loading, distribution ratio, thermodynamic parameters, and the kinetic mechanism involved in the Pt(IV)-HCl-Cyanex 921 system used. Inductively coupled plasma emission spectroscopy (ICP-ES) was used to measure the platinum concentration in the aqueous phase with a mass balance being used to determine the concentration of platinum in the organic phase. Using a combination of the variables under investigation, the experiments which were evaluated indicated that it is possible to extract sufficient platinum chlorocomplex under the following conditions: pH of 1, Cyanex 921 concentration of 8% (v/v), temperature of 298 K and an initial platinum concentration of 55.22 mg/L. Under these conditions the maximum organic-phase loading of 253.9 mg/L was achieved as compared to the theoretical loading of 507.24 mg/L. The equilibrium loading of ~50% of the platinum chlorocomplex in the organic phase was achieved after 2400 seconds of reactor operation. In this case, a distribution ratio of 9.4 was achieved. This value was observed to be higher as compared to the other SX conditions evaluated in this study.
90

Removal and recovery of aluminium and sulphate ions from an alkaline medium using solvent extraction

Mpinga, Cleophace Ngoie January 2009 (has links)
Thesis submitted in fulfilment of the requirements for the degree Master of Technology: Chemical Engineering in the Faculty of Engineering at the Cape Peninsula University of Technology / Throughout the world, many water resources are polluted by industrial and domestic effluents, acid mine drainage, etc. The increasing awareness and concern about the environment has motivated in the recent years extensive research into developing new efficient, cost effective and environmentally sound technologies to treat industrial solutions bearing metals and sludges. From the literature review, much research has been, and is still being devoted to the performance of solvent extraction (SX) of aluminium or sulphate in acidic solutions and how to improve such performance. There is a general lack of information on liquid-liquid extraction of aluminium or sulphate in an alkaline solution. Thus, the need for a systematic investigation into the solvent extraction of aluminium and sulphate in an alkaline medium was important. This thesis focuses on the study of solvent extraction of aluminium and sulphate from alkaline solutions using Trioctylmethylammonium chloride, (Aliquat 336), in Kerosene as diluent.

Page generated in 0.0517 seconds