Life-time measurement of ^7Be in beryllium metal(II. Radiochemistry)

The decay rate of ^7Be (nucleus of electron-capture decay) was measured in Be metal. The half life of ^7Be in Be metal (Be metal (^7Be)) is found to be 53.12±0.05 days. We have found that the decay rate of ^7Be in Be metal is almost corresponding to that in graphite host, Lithium fluoride host etc. reported within the errors

Hydrogen/deuterium absorption capacity of Pd nanomaterials and its relation with heat generated upon loading of hydrogen isotope gases

Abstract: Using Sievert's method, hydrogen/deuterium absorption capacity was measured for Pd nanopowder and nanocomposites of nanoPd/ γ Al2O3 and nanoPd/ZrO2. For these materials, heat evolution upon loading of hydrogen isotope gases was also measured by a flow calorimeter. In order to identify the properties of metallic Pd nanoparticles, both measurements were conducted repeatedly three or four times without exposing the samples to air. It was found that both apparent absorption capacity and heat evolution depended strongly on the degree of oxidation of Pd. The amount of the oxidized Pd in each sample was estimated from the difference between the apparent and the true values of hydrogen/deuterium absorption capacity and used to evaluate the heat generated from chemical reactions. The hydrogen absorption capacity at 1MPa was found to be slightly smaller than that of Pd bulk for all the Pd nanomaterials studied. The heat evolution was composed of two stages, i.e., the first stage during pressurizing the samples from 0 to 1MPa and the second stage where the the sample was kept under a fixed pressure of 1MPa. The heat generated in the first stage was largely explained by taking into account two chemical reactions, i.e., the water formation reaction and the hydride/deuteride formation reaction. It was noted that in the second stage, where the heat generated from chemical reactions was hardly expected to occur, a small heat power was observed intermittently when the samples were loaded with deuterium gas