A thermal analysis investigation of the hydriding properties of nanocrystalline mg-ni based alloys prepared by high energy ball milling

A thermal analysis study of the hydrogen loading characteristics of nanocrystalline Mg-Ni alloys (Ni content ranging from 0.1 at% to 10 at%) has been carried out in 3 MPa hydrogen, employing the techniques of differential scanning calorimetry and thermogravimetric analysis (TGA). The measurements confirmed the nonequilibrium state of the samples as prepared by the mechanical alloying technique. An enthalpy associated with the stabilisation of the alloys on first heating in hydrogen was found for all the samples studied. The magnitude of this enthalpy increased with the nickel content of the alloy. All the samples showed rapid uptake of hydrogen at 3 MPa pressure, indicating that the nickel was thus playing a very active role at the alloy surface in dissociating hydrogen and so enabling more rapid hydride formation by the alloy. This catalytic activity of the nickel decreased with temperature cycling over the range 80°C to 500°C. Although TGA analysis, carried out at the end of the cycling period, gave the hydrogen content as 1.1 wt% to 1.7 wt% for the alloys, this is well short of the theoretical amounts expected (7.6 wt% for MgH2), indicating that the samples had become deactivated during cycling. No evidence was found of the intermetallic Mg,Ni prior to or after hydriding

Thermal analysis investigation of hydriding properties of nanocrystalline Mg-Ni- and Mg-Fe-based alloys prepared by high-energy ball milling

The hydrogen loading characteristics of nanocrystalline Mg, Mg–Ni (Ni from 0.1 to 10 at.%), and Mg–Fe (Fe from 1 to 10 at.%) alloys in 3 MPa H2 were examined using high pressure differential scanning calorimetry and thermogravimetric analysis. All samples showed rapid uptake of hydrogen. A decrease in the onset temperature for hydrogen absorption was observed with increasing Ni and Fe alloy content, but the thermal signatures obtained suggested that only Mg was involved in the hydriding reaction; i.e., no clear evidence was found for the intermetallic hydrides Mg2NiH4 and Mg2FeH6. Hydrogen loading capacity decreased with temperature cycling, and this was attributed to a sintering process in the alloy, leading to a reduction in the specific surface available for hydrogen absorption

Financial Inclusion and Social Protection: A Case for India Post

Analysis of empirical evidence from three Indian states suggests that financial inclusion strategies may be inefficient if designed without accounting for the government social protection programmes. Social protection programmes generate additional needs for financial services among the poor, meeting which can also deepen the impact of such programmes. Being a government department and the largest financial service-providing network, India Post may be most suitably located to implement such synergistic strategies. An examination of the official data on India Post indicates that the approach of diversifying its financial products to target higher-end clients in largely urban areas may not be appropriate due to its competitive disadvantage. We argue that delivery of financial services through post offices, built around social protection, may contribute to financial inclusion in rural areas while improving revenues of India Post