H_2 Dissociative Adsorption at the Armchair Edges of Graphite

We investigate and discuss how hydrogen behaves at the edges of a graphite sheet, in particular the armchair edge. Our density functional theory-based calculations results show that, in contrast to the zigzag edge [cf., e-J. Surf. Sci. Nanotech. 2 (2004) 77], regardless of orientation, there is an activation barrier hindering H_2 dissociation at the armchair edges. And once they do get dissociatively adsorbed at the armchair edges, we find that it would be extremely hard to desorb the H from their adsorption sites at the armchair edges. Furthermore, we also found that, consistent with our earlier conclusions [cf., J. Phys. Soc. Jpn. 72 (2003) 1867], it is unlikely that we would find a whole H_2 in between plain graphite sheets.Comment: 4 pages, 5 figures, preprin

A Study on Maturity Model of Open Source Software Community to Estimate the Quality of Products

AbstractOpen Source Software (OSS) is a new paradigm to develop software by community, in which groups of developer collaborating each other. The method becomes very popular because the products of OSS projects, such as source code, documents, results of tests, are published by open-license. One of noticeable features of OSS is openness of project. Anyone can access the products of OSS projects. It is expected that the quality of products could be higher than those developed by conventional methods, as more people access OSS products and the chance to find defect could be larger. However, there are no established methods for the evaluation of OSS, neither actual terms of the evaluation of OSS. We propose an evaluation method, which is based on the maturity model of OSS development community

Growth of Cu-1.1at.% Sn and Cu-1.7at.% In Alloy Single Crystals

Attempts have been made to grow large single crystals of Cu-1.1at.% Sn and Cu-1.7at.% In alloys from the melt by the Bridgman method. Microscopic observation of the chemically etched surfaces and sections of the alloy ingots has shown that they contain a few large grains, if the growing condition is properly chosen, but otherwise they consist of columnar grains. The growth direction of the columnar grains determined by the X-ray Laue method exhibits a slight preference of the and directions for the Cu-Sn alloy and the and directions for the Cu-In alloy. A concentration profile in the grain investigated by EPMA has shown an appreciable fluctuation in as-grown crystals and an annealing in vacuum at 900℃ for 100 hr has resulted in a homogenization. The alloy crystals thus heat-treated provide the specimens suitable to LEED studies