kim thoa pham | University of Gloucestershire (original) (raw)

Papers by kim thoa pham

Research paper thumbnail of Synthesis of nano-structured polypyrrole/copper electrodes for nitrate and nitrite electroreductionReport submitted to the 5th International Workshop on Advanced Materials Science and Nanotechnology IWAMSN, Hanoi, 9–12 November 2010

Advances in Natural Sciences: Nanoscience and Nanotechnology, 2010

Nanostructured polypyrrole film was synthesized onto a copper electrode in solutions of oxalic an... more Nanostructured polypyrrole film was synthesized onto a copper electrode in solutions of oxalic and salicylic acids and their buffers. The electrooxidation of pyrrole to form polypyrrole film and the electroreduction of nitrate and nitrite ions at synthesized Ppy modified copper electrodes (Ppy/Cu) in potassium chloride aqueous solutions were studied using chronoamperometry. The nanoporous structure of the synthesized Ppy films was characterized by scanning electron microscopy (SEM). Nitrate and nitrite reduction were performed by an electrochemical method under potentiostatic conditions. The Ppy/Cu electrodes prepared in the oxalate buffer and salicylic acid solutions perform more stable catalytic activity for nitrate reduction; their service life is about ten times longer than that for the electrodes prepared in oxalic acid solution. After 20 h of electrolysis, the nitrite was reduced completely with 100% efficiency and the nitrate was reduced with 35% efficiency.

Research paper thumbnail of Hydrogeological investigation in the Mekong Delta around Ho-Chi-Minh City (South Vietnam) by electric tomography

Comptes Rendus Geoscience, 2002

In the Mekong Delta (South Vietnam), the agglomeration of Ho-Chi-Minh (HCM) City, with more than ... more In the Mekong Delta (South Vietnam), the agglomeration of Ho-Chi-Minh (HCM) City, with more than 5 million inhabitants, is confronted with a dramatic shortage of fresh water supply because of the pollution of several aquifers at different depths. The electric tomography, obtained by concurrent inversion of two complementary geoelectrical methods, the Vertical Electrical Sounding (VES) and the Magneto-Telluric Sounding (MTS), turned out to be very efficient to provide a complete electrical image of the underground from the surface until about 800 m depth. This methodology constitutes a very cheap guide for the evaluation of the quality of the groundwater resources in the vast alluvial plain of the Mekong Delta. To cite this article: V.N. Pham et al., C. R. Geoscience 334 (2002) 733-740.  2002 Académie des sciences / Éditions scientifiques et médicales Elsevier SAS electric tomography / hydrogeological investigation / groundwater quality / Mekong Delta Résumé -Investigation hydrogéologique dans le delta du Mékong, autour de la ville de Ho-Chi-Minh (Sud-Vietnam), par tomographie électrique. Dans le delta du Mékong au Sud Vietnam, l'agglomération de Ho-Chi-Minh (HCM), avec plus de 5 millions d'habitants, est confrontée à un énorme problème d'alimentation en eau potable, du fait de la pollution des diverses nappes aquifères superficielles et profondes. La tomographie électrique, obtenue par inversion conjointe de deux méthodes géoélectriques complémentaires, le sondage électrique (SE) et le sondage magnéto-tellurique (SMT), se révèle très efficace pour fournir une image électrique complète du sous-sol, depuis la surface jusqu'à une profondeur de 800 m environ. Cette méthodologie constitue un guide très économique dans l'évaluation de la qualité des ressources d'eau souterraine dans la vaste plaine alluviale du delta du Mékong. Pour citer cet article : V.N. Pham et al., C. R. Geoscience 334 (2002) 733-740.  2002 Académie des sciences / Éditions scientifiques et médicales Elsevier SAS tomographie électrique / investigation hydrogéologique / qualité de l'eau souterraine / delta du Mékong

Research paper thumbnail of Deep Ground-Water Investigation by Combined VES/MTS Methods Near Ho Chi Minh City, Viet Nam

Ground Water, 1994

In the agglomeration of Ho Chi Minh City (HCMC), South Viet Nam, located near the eastern edge of... more In the agglomeration of Ho Chi Minh City (HCMC), South Viet Nam, located near the eastern edge of the Mekong Delta, both superficial Quaternary and deep Tertiary Alluvium may contain brackish or saline water from ground surface to great depths. The combination of two complementary geophysical methods, the Vertical Electrical Sounding (VES) for shallow investigation, and the Magnetotelluric Sounding (MTS) for deep investigation, gives a more complete electrical image of the sedimentary series from the surface to the deep crystalline basement. It turned out to be very efficient in delineating the ground-water contamination in both superficial and deep aquifers. The combined results reveal a close correlation of the extent of the contamination with the paleo-geomorphology of laterites, and subsequently with the paleorelief during the Tertiary and Quaternary periods. A simple guide for hydrogeological investigation is proposed in connection with the present topography and the Tertiary tectonics.

Research paper thumbnail of Trial participation and vaccine desirability for Vi polysaccharide typhoid fever vaccine in Hue City, Viet Nam: Trial participation and vaccine desirability, Hue City

Tropical Medicine & International Health, 2006

Objectives: To identify demand for Vi typhoid fever vaccine for school-age children; obstacles an... more Objectives: To identify demand for Vi typhoid fever vaccine for school-age children; obstacles and interval; controlled clinical trial; controlled study; demography; disease severity; double blind procedure;

Research paper thumbnail of Synthesis of nano-structured polypyrrole/copper electrodes for nitrate and nitrite electroreductionReport submitted to the 5th International Workshop on Advanced Materials Science and Nanotechnology IWAMSN, Hanoi, 9–12 November 2010

Advances in Natural Sciences: Nanoscience and Nanotechnology, 2010

Nanostructured polypyrrole film was synthesized onto a copper electrode in solutions of oxalic an... more Nanostructured polypyrrole film was synthesized onto a copper electrode in solutions of oxalic and salicylic acids and their buffers. The electrooxidation of pyrrole to form polypyrrole film and the electroreduction of nitrate and nitrite ions at synthesized Ppy modified copper electrodes (Ppy/Cu) in potassium chloride aqueous solutions were studied using chronoamperometry. The nanoporous structure of the synthesized Ppy films was characterized by scanning electron microscopy (SEM). Nitrate and nitrite reduction were performed by an electrochemical method under potentiostatic conditions. The Ppy/Cu electrodes prepared in the oxalate buffer and salicylic acid solutions perform more stable catalytic activity for nitrate reduction; their service life is about ten times longer than that for the electrodes prepared in oxalic acid solution. After 20 h of electrolysis, the nitrite was reduced completely with 100% efficiency and the nitrate was reduced with 35% efficiency.

Research paper thumbnail of Hydrogeological investigation in the Mekong Delta around Ho-Chi-Minh City (South Vietnam) by electric tomography

Comptes Rendus Geoscience, 2002

In the Mekong Delta (South Vietnam), the agglomeration of Ho-Chi-Minh (HCM) City, with more than ... more In the Mekong Delta (South Vietnam), the agglomeration of Ho-Chi-Minh (HCM) City, with more than 5 million inhabitants, is confronted with a dramatic shortage of fresh water supply because of the pollution of several aquifers at different depths. The electric tomography, obtained by concurrent inversion of two complementary geoelectrical methods, the Vertical Electrical Sounding (VES) and the Magneto-Telluric Sounding (MTS), turned out to be very efficient to provide a complete electrical image of the underground from the surface until about 800 m depth. This methodology constitutes a very cheap guide for the evaluation of the quality of the groundwater resources in the vast alluvial plain of the Mekong Delta. To cite this article: V.N. Pham et al., C. R. Geoscience 334 (2002) 733-740.  2002 Académie des sciences / Éditions scientifiques et médicales Elsevier SAS electric tomography / hydrogeological investigation / groundwater quality / Mekong Delta Résumé -Investigation hydrogéologique dans le delta du Mékong, autour de la ville de Ho-Chi-Minh (Sud-Vietnam), par tomographie électrique. Dans le delta du Mékong au Sud Vietnam, l'agglomération de Ho-Chi-Minh (HCM), avec plus de 5 millions d'habitants, est confrontée à un énorme problème d'alimentation en eau potable, du fait de la pollution des diverses nappes aquifères superficielles et profondes. La tomographie électrique, obtenue par inversion conjointe de deux méthodes géoélectriques complémentaires, le sondage électrique (SE) et le sondage magnéto-tellurique (SMT), se révèle très efficace pour fournir une image électrique complète du sous-sol, depuis la surface jusqu'à une profondeur de 800 m environ. Cette méthodologie constitue un guide très économique dans l'évaluation de la qualité des ressources d'eau souterraine dans la vaste plaine alluviale du delta du Mékong. Pour citer cet article : V.N. Pham et al., C. R. Geoscience 334 (2002) 733-740.  2002 Académie des sciences / Éditions scientifiques et médicales Elsevier SAS tomographie électrique / investigation hydrogéologique / qualité de l'eau souterraine / delta du Mékong

Research paper thumbnail of Deep Ground-Water Investigation by Combined VES/MTS Methods Near Ho Chi Minh City, Viet Nam

Ground Water, 1994

In the agglomeration of Ho Chi Minh City (HCMC), South Viet Nam, located near the eastern edge of... more In the agglomeration of Ho Chi Minh City (HCMC), South Viet Nam, located near the eastern edge of the Mekong Delta, both superficial Quaternary and deep Tertiary Alluvium may contain brackish or saline water from ground surface to great depths. The combination of two complementary geophysical methods, the Vertical Electrical Sounding (VES) for shallow investigation, and the Magnetotelluric Sounding (MTS) for deep investigation, gives a more complete electrical image of the sedimentary series from the surface to the deep crystalline basement. It turned out to be very efficient in delineating the ground-water contamination in both superficial and deep aquifers. The combined results reveal a close correlation of the extent of the contamination with the paleo-geomorphology of laterites, and subsequently with the paleorelief during the Tertiary and Quaternary periods. A simple guide for hydrogeological investigation is proposed in connection with the present topography and the Tertiary tectonics.

Research paper thumbnail of Trial participation and vaccine desirability for Vi polysaccharide typhoid fever vaccine in Hue City, Viet Nam: Trial participation and vaccine desirability, Hue City

Tropical Medicine & International Health, 2006

Objectives: To identify demand for Vi typhoid fever vaccine for school-age children; obstacles an... more Objectives: To identify demand for Vi typhoid fever vaccine for school-age children; obstacles and interval; controlled clinical trial; controlled study; demography; disease severity; double blind procedure;