Element cycling during the transition from alkaline to acidic environment in an active porphyry copper tailings impoundment, Chuquicamata, Chile

2014 ◽  
Vol 140 ◽  
pp. 23-40 ◽  
Author(s):  
Jochen Smuda ◽  
Bernhard Dold ◽  
Jorge E. Spangenberg ◽  
Kurt Friese ◽  
Max R. Kobek ◽  
...  
Keyword(s):  
Porphyry Copper ◽  
Acidic Environment ◽  
Element Cycling ◽  
Copper Tailings ◽  
Tailings Impoundment

Microbial communities in a porphyry copper tailings impoundment and their impact on the geochemical dynamics of the mine waste

2007 ◽  
Vol 9 (2) ◽  
pp. 298-307 ◽  
Author(s):  
Nouhou Diaby ◽  
Bernhard Dold ◽  
Hans-Rudolf Pfeifer ◽  
Christof Holliger ◽  
D. Barrie Johnson ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Mine Waste ◽  
Porphyry Copper ◽  
Copper Tailings ◽  
Tailings Impoundment

MICROBIAL STUDY OF THE MARINE SHORE PORPHYRY COPPER TAILINGS DEPOSIT BAHIA DE ITE, PERU

2006 ◽  
Vol 2006 (2) ◽  
pp. 493-497
Author(s):  
Nouhou Diaby ◽  
Bernhard Dold ◽  
Christof Holliger ◽  
Rodolfo Vicetti ◽  
Ezio Buselli
Keyword(s):  
Porphyry Copper ◽  
Copper Tailings ◽  
Microbial Study

Low Molecular Weight Carboxylic Acids in Oxidizing Porphyry Copper Tailings

2005 ◽  
Vol 39 (8) ◽  
pp. 2515-2521 ◽  
Author(s):  
Bernhard Dold ◽  
David W. Blowes ◽  
Ralph Dickhout ◽  
Jorge E. Spangenberg ◽  
Hans-Rudolf Pfeifer
Keyword(s):  
Molecular Weight ◽  
Carboxylic Acids ◽  
Porphyry Copper ◽  
Low Molecular Weight ◽  
Copper Tailings

pH Dependent Release Potential of Natural Polymers in Sustained Release of Ornidazole From Colon Targeted Delivery System)

2019 ◽  
Vol 9 (02) ◽  
Author(s):  
Sharma Pankaj ◽  
Tailang Mukul
Keyword(s):  
Drug Release ◽  
Delivery System ◽  
Targeted Delivery ◽  
Guar Gum ◽  
Acidic Environment ◽  
Natural Polymers ◽  
Weight Variation ◽  
Curve Determination ◽  
Preformulation Studies

The aim of present work was to prepare colon specific delivery system of Ornidazole using different ratio of shellac, zein and guar gum. From study of various literature it revealed that shellac, zein and guar gum released drug from dosage form at the pH of 6.9, 11.5, 7-9 respectively. The main problem associated with colon targeted drug delivery system is degradation of drug in the acidic environment of stomach to circumvent the present problem different combinations of shellac, zein and guar gum were employed in the formulation of colon targeted tablet. Several preformulation parameters were determined such as melting point, FTIR spectroscopy, preparation of calibration curve, determination of λmax and partition coefficient. After the preformulation studies, next steps were preparation of core tablets, evaluation of core of tablets and coating of tablets. The data obtained from preformulation study seven formulations were developed and evaluated for various parameters. Based on evaluated parameter such as weight variation, friability, dissolution study, invitro drug release etc. the F7 formulation show better results colon targeted tablets. Drug content in F7 formulation was 95% and drug release after 6 hrs was 96%. Formulation containing combination of shellac, zein and guar gum released least amount of drug in the acidic environment of stomach and released most of the drug in colon. It is evide

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