http://nopr.niscair.res.in/handle/123456789/2772 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/2878 Title: Bioleaching of low-grade copper ore using indigenous microorganisms <br/> <br/>Authors: Pradhan, D; Pal, S; Sukla, LB; Chaudhury, G Roy; Das, T <br/> <br/>Abstract: Investigations have been carried out on the iron oxidation rate of Acidithiobacillus ferrooxidans, the bacteria used in bioleaching process. It was observed that the regeneration time of the bacteria is reduced from 168 to 16 h by repeated sub-culturing, which in turn gave rise to higher iron oxidation rate thus increasing the kinetics of the process. This active strain was utilized for bioleaching of low-grade copper ore by varying two parameters namely, pH and pulp density. It was observed that around 30% of copper could be leached at an initial pH and pulp density of 2 and 20% (m/v) respectively. <br/> <br/>Page(s): 588-592 Wed, 29 Oct 2008 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/2877 Title: Validated liquid chromatographic method for simultaneous estimation of albendazole and ivermectin in tablet dosage form <br/> <br/>Authors: Waldia, Anil; Gupta, Shubash; Issarani, Roshan; Nagori, Badri P <br/> <br/>Abstract: A reverse phased liquid chromatography (LC) method was developed and validated for simultaneous estimation of albendazole and ivermectin in tablet dosage form. The isocratic LC analysis was performed on NUCLEODUR C18 RP column (250 x 4.6 mm, 5 µ) using mobile phase composed of acetonitrile, methanol and water in ratio of 60:30:10 (v/v/v) at a flow rate of 1.8 mL/min. Quantitation was performed using UV detector at 245 nm and the run time was 20 min. The retention times were found to be 3.56 min for albendazole and 10.08 min for ivermectin. The analytical method was validated according to ICH guidelines. The linearity was observed in the range of 400–800 and 6–12 μg/mL with correlation coefficient, r=0.9975 and 0.9969 for albendazole and ivermectin respectively. The relative standard deviation values for repeatability and intermediate precision studies were less than 2%, and the accuracy (% recovery) was greater than 98% for both the drugs. The method was successfully applied for market sample analysis and mean percentage assay values were 98.68±0.28 and 98.67±0.50 for albendazole and ivermectin respectively. The present method is precise and accurate and can be used for the routine estimation of albendazole and ivermectin in tablet dosage forms. <br/> <br/>Page(s): 617-620 Wed, 29 Oct 2008 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/2876 Title: Development of Zn-Co alloy coatings by pulsed current from chloride bath <br/> <br/>Authors: Thangaraj, V; Udayashankar, N K; Hegde, A Chitharanjan <br/> <br/>Abstract: Zinc-M (where M = Ni, Co and Fe) alloy is of great interest owing to their better mechanical and corrosion properties compared with pure zinc coatings. Corrosion resistance of Zn-Co alloy coatings can be improved considerably by pulse plating. The paper details the optimization of Zn-Co alloy bath using pulsed current and details the superiority of pulse plating over direct current plating. Electroplating of Zn-Co alloys over mild steel was carried out under different conditions of pulse parameters like duty cycle, frequency and peak current density. The production and properties of the deposits were found to be influenced by pulse parameters employed. Within the ranges studied, the bath follows anomalous codeposition with preferential deposition of less noble zinc. The influence of current density on %wt. of Co in the deposit and cathode current efficiencies was studied. It was observed that the deposit at average current density of 5.0 A.dm⁻², 50% duty cycle and 100 Hz frequency showed excellent corrosion resistance with fine structure. The peak performance of pulse electrodeposit against corrosion was attributed to the change in the surface homogeneity as evidenced by scanning electron microscope (SEM) image. The drastic decrease of corrosion rate in pulse electrodeposit was attributed to the formation of semiconductor films on the surface as supported by impedance spectroscopy signals. <br/> <br/>Page(s): 581-587 Wed, 29 Oct 2008 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/2875 Title: Zinc-poly (aniline) rechargeable battery assembled with aqueous electrolyte <br/> <br/>Authors: Dalui, Bharat Chandra; Basumallick, I N; Ghosh, Susanta <br/> <br/>Abstract: The electrochemical behaviours of electro-synthesized poly(aniline) (PANI) cathode and commercial zinc anode in an aqueous electrolyte were investigated. The poly(aniline) sulphate cathodes were synthesized by galvanostatic oxidation of aniline from a sulphuric acid bath on platinum substrate and characterized by UV-Visible and FTIR spectroscopy. The electrolyte is comprised of ammonium sulphate and zinc sulphate dissolved in double distilled water. The slow scan linear voltammetry (Tafel plot) for the commercial zinc anode was recorded in this electrolyte and compared with its behaviour in chloride electrolyte. A negative shift of the open circuit potential of 55 mV, decrease in exchange current density of one order, and increase of cathodic Tafel slope in this sulphate electrolyte was observed. The above facts enhance the cell potential and the reversibility of the cell having the configuration, PANI || (NH₄)₂SO₄, ZnSO₄ (aq) || Zn. A discharge pleato with an average discharge potential of 1.1 V, which varied depending on the discharge current density, was observed for this reversible cell. The maximum discharge capacity, observed from this cell in the sulphate electrolyte, is 137 mAh.g⁻¹. <br/> <br/>Page(s): 576-580 Wed, 29 Oct 2008 22:58:59 GMT