In a recent article [J. Rajagopalan, J.H. Han, M.T.A. Saif, Science 315 (2007) 1831–1834], we have reported substantial (50–100%) plastic strain recovery in freestanding nanocrystalline metal films (grain size 50–65 nm) after unloading. The strain recovery was time dependent and thermally activated. Here we model the time evolution of this strain recovery in terms of a thermally activated dislo...

Heavy metal remediation of aqueous streams is of special concern due to recalcitrant and persistency of heavy metals in environment. Conventional treatment technologies for the removal of these toxic heavy metals are not economical and further generate huge quantity of toxic chemical sludge. Biosorption is emerging as a potential alternative to the existing conventional technologies for the rem...

A hydrmetallurgical study based on the extraction of Zn and Pb from a Nigerian sphalerite mineral leached with 4 M hydrochloric acid has been undertaken. Triphenylphosphite (TPP) has proved to be very effective for the extraction of zinc. With 2 M TPP and at ambient temperature of 25±2°C; 35.71% and 66.7% of Pb and Zn were extracted, respectively, into the organic phase within 60 min. The recov...

a hydrmetallurgical study based on the extraction of zn and pb from a nigerian sphalerite mineral leached with 4 m hydrochloric acid has been undertaken. triphenylphosphite (tpp) has proved to be very effective for the extraction of zinc. with 2 m tpp and at ambient temperature of 25±2°c; 35.71% and 66.7% of pb and zn were extracted, respectively, into the organic phase within 60 min. the recov...

the oxidative coupling of methane (ocm) over m-na-mn/sio2 catalysts (m=w, cr, nb and v) was investigated using a continuous-flow quartz reactor at 775°c, 1 atm and 100 cm3min-1 gas flow rates, and correlated with the observed structure and redox properties.the interaction effects of the metal-metal and metal-support on the methane conversion and c2+ yield were investigated using x-ray diffracti...

This paper presents a unique approach for magnesium dosage in struvite precipitation by Mg metal corrosion. The experimental results showed that using an air bubbling column filled with Mg metal and graphite pellets for the magnesium dosage was the optimal operation mode, which could significantly accelerate the corrosion of the Mg metal pellets due to the presence of graphite granules. The rea...

The electrocoagulation/flotation process is a novel approach in mining industry that is implemented to return Cu metal to the production cycle, which improves copper recovery and reduces waste water. In this research work, the response surface methodology was applied to optimize the factors effective in Cu metal recovery and sludge volume produced from thickener overflow. To this end, the D-opt...

The present paper put forth the isolation and complete characterization of three bacterial isolates from different sites of East Calcutta Wetland (ECW). These isolates show tolerance to heavy metals like Ag, Al, Cu, Cr, Co, Ni, Pb and were found to be efficient metal accumulators as evident from Energy Dispersive X Ray Fluorescence (EDXRF) analysis and Transmission Electron Microscopy (TEM). Be...

This paper reviewed over 100 articles on the subject of the mechanism of catalyst layer (CL) degradation and the effect of various contaminations in the polymer electrolyte membrane fuel cell (PEMFC). Also the recovery of PEMFC via different types of methods, the causes and fundamental mechanisms of cell degradation and their influence on long- term performance of PEM fuel cell were discussed i...