53 research outputs found

    Investigation of structure and hydrogen bonding of super-hydrous phase B (HT) under pressure using first principles density functional calculations

    Get PDF
    High pressure behaviour of superhydrous phase B(HT) of Mg10Si3O14(OH)4 (Shy B) is investigated with the help of density functional theory based first principles calculations. In addition to the lattice parameters and equation of state, we use these calculations to determine the positional parameters of atoms as a function of pressure. Our results show that the compression induced structural changes involve cooperative distortions in the full geometry of the hydrogen bonds. The bond bending mechanism proposed by Hofmeister et al [1999] for hydrogen bonds to relieve the heightened repulsion due to short H--H contacts is not found to be effective in Shy B. The calculated O-H bond contraction is consistent with the observed blue shift in the stretching frequency of the hydrogen bond. These results establish that one can use first principles calculations to obtain reliable insights into the pressure induced bonding changes of complex minerals.Comment: 16 pages, 4 figure

    The features of decision making process in international companies. Are companies in control of their own decisions?

    No full text
    The following article deals with the main causes of irrational decision making process in companies and with respective solutions to make decisions more rational and effective. With the aid of relevant literature, the ways managers, groups and leaders make decisions in reality will be clarified. Besides, the solutions to rational decisions examined through the perspective of managers, leaders and groups. Thus, the background of this article is the question “Are companies in control of their own decisions?” In addition, this paper includes relevant information about the features of decision making process, basic types of decisions, describes the most essential approach in management regarding to decision making and presents the top worst and best business decisions of all time
    corecore