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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.
191

Optimisation of scale-up of chromatography / by Christopher Brett Colby.

Colby, Christopher Brett January 1997 (has links)
Bibliography: leaves 225-230. / xxi, 235 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis investigates the scale-up of an ion-exchange chromatographic system to manufacture whey growth factor extract (WGFE) from cheese whey. Key scale-up problems are identified and discussed. Alternative scale-up methodologies required to overcome several of these problems are considered. / Thesis (Ph.D.)--University of Adelaide, Dept. of Chemical Engineering, 1997?
192

Use of affordable technology for the sensitive and specific diagnosis of onchocerciasis (river blindness) /

Guzmán Laparra, Gabriel Eduardo, January 2002 (has links)
Diss. (sammanfattning) Stockholm : Karol. inst., 2002. / Härtill 6 uppsatser.
193

The application of ion-exchanged clay as corrosion inhibiting pigments in organic coatings

Chrisanti, Santi, January 2008 (has links)
Thesis (Ph. D.)--Ohio State University, 2008. / Title from first page of PDF file. Includes bibliographical references (p. 245-251).
194

Adsorption of proteins by ion exchange resins with application to specific agglutination

Donaldson, Paul. January 1947 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1947. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 70-[72]).
195

Ion-exchange sample probe for laser ablation-ICP-AES /

Yip, Hung-chiu. January 1998 (has links)
Thesis (M. Phil.)--University of Hong Kong, 1998. / Includes bibliographical references (leaf 154).
196

Simulation of ion exchange processes using neuro-fuzzy reasoning /

Van den Bosch, Magali Marie. January 1900 (has links)
Thesis (MTech (Chemical Engineering)) -- Cape Peninsula University of Technology, 2009. / Includes bibliographical references (leaves 81-83). Also available online.
197

Sorption properties of natural zeolites for the removal of ammonium and chromium ions in aqueous solution

Ndayambaje, Guillaume January 2011 (has links)
>Magister Scientiae - MSc / There are huge amount of natural clinoptilolite available in South Africa which can be utilised for wastewater treatment of ammonia and chromium if their characteristics are properly known. However, these deposits have not been well characterised but in this study, the untreated clinoptilolite materials were fully characterised using techniques such as SEM-EDS, HRTEM-SAED, XRD, XRF, FTIR and BET. After acid pretreatment with several extractions, the pretreated samples were again characterised using the above mentioned techniques. These pretreated materials were used for NH₄⁺ and Cr³⁺ adsorption of wastewater. The three natural South African clinoptilolite samples used in this study were from ECCA Holdings (ESC and EHC samples) and Pratley (PC sample) deposits obtained from Western Cape and KwaZulu-Natal Province respectively. This study revealed that the chemical composition and mineral phases of South African clinoptilolites vary considerably from site to site, even clinoptilolite mined from the same deposit sites. The XRD analyses showed that Pratley clinoptilolite (PC) was the most pure clinoptilolite sample (81.41 %) compared to the purity of EHC (67.88 %) and ESC (44.0 %) sample. The ECCA Holdings untreated clinoptilolite samples contained dense phases such as quartz which was not found in Pratley sample. Quartz was found to be the most dominant impurity in both ECCA Holding sample. The cation exchange capacity (CEC) of ESC, EHC and PC samples were found to be 1.23, 1.81 and 2.90 meq/g respectively and these results were compared to that of XRF analyses. The acid solutions of 0.02 and 1.0 M HCl were used to pretreat natural clinoptilolite to determine the optimum acid concentration and number of extractions required to fully replace the exchangeable cations. The pretreatment results showed that 0.02 M HCl was the optimum acid concentration for acid pretreatment of clinoptilolite samples. Between 7 and 22 extractions were required to remove Na⁺, K⁺, Ca²⁺ and Mg²⁺ without causing much dealumination of the framework. Sodium ion was found to be weakly bound cation in the clinoptilolite framework, since it could be completely exchanged by H⁺ after 7 extractions with 0.02 M HCl acid solution. Potassium ion was found to be strongly bound in the clinoptilolite framework since it could not be completely exchanged during the acid pretreatment process even after 22 extractions. The HRTEM-SAED and BET results showed that ESC, EHC and PC were all polycrystalline and microporous materials respectively. It was found that the adsorption capacity of the treated Pratley clinoptilolite sample was increased by 36 % for NH₄⁺ removal, compared to that of the untreated PC sample. The adsorption study results showed that the pretreatment of clinoptilolite samples using 150 mL volumes of 0.02 M HCl with 7 acid extractions at 25 °C for ESC pretreated and EHC pretreated. The pretreatment of PC sample at 22 extractions could remove high percentage of NH₄⁺ (98.11 %) within a short contact time of 10 min. The pretreated Pratley clinoptilolite sample was found to be the best NH₄⁺ adsorbent (98.11 % NH₄⁺ removal) compared to EHC treated (93.89 % NH₄⁺ removal) and ESC treated (75.00 % NH₄⁺ removal) clinoptilolite samples. However, acid-pretreated Pratley clinoptilolite did not sufficiently remove Cr³⁺ (16.10 %) from synthetic wastewater showing that it is not a good adsorbent for this particular metal ion removal. Despite several studies that have been conducted on clinoptilolite, no study has been carried out on the pretreatment and comparison of sorption capacity of different South African clinoptilolites for the removal of NH₄⁺ from wastewater. This study has been able improve on the acid-pretreatment procedure for clinoptilolite. This study demonstrated that it is not only the acid concentration that is important but also the number of extractions needed to remove all the exchangeable cations from the clinoptilolite framework. This study has also been able to prove that South African clinoptilolite can treated ammonia from wastewater.
198

Cromatografia de ions aplicada na especia‡ao de cromio hexavalente em amostras de interesse ambiental

MARQUES, MARIA N. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:43:29Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:58:25Z (GMT). No. of bitstreams: 1 06497.pdf: 7575269 bytes, checksum: 3551f60999aef01a16217b24b89a7f9b (MD5) / Mestrado (Dissertacao) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
199

Transformacao de sulfato de torio em nitrato de torio por resina de troca ionica

PEREIRA, WALTER 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:36:42Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:59:08Z (GMT). No. of bitstreams: 1 04228.pdf: 1369368 bytes, checksum: 9359a42d983a5041a2b1e9d46808ee7d (MD5) / Dissertacao (Mestrado) - IPEN / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
200

Uso da voltametria cíclica e da espectroscopia de impedância eletroquímica na determinação da área superficial ativa de eletrodos modificados à base de carbono / Use a cyclic voltammetry and electrochemical impedance spectroscopy for the determination of active surface area of modified carbon-based electrodes

SOUZA, LETICIA L. de 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:34:05Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:59:48Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

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