Diffusion MRI modelling from first principles

ER modelling from first relational principles

Entity-Relationship modelling is a popular technique for data modelling. Despite its popularity and wide spread use, it lacks a firm semantic foundation. We propose a translation of an ER-model into relation algebra, suggesting that this kind of algebra does provide suitable mechanisms for establishing a formal semantics of Entity-Relationship modelling. The work reported on here deals first wi...

Adsorption and diffusion of water on graphene from first principles

Jie Ma,1 Angelos Michaelides,2,* Dario Alfè,3 Laurids Schimka,4 Georg Kresse,4 and Enge Wang5,1 1Institute of Physics, Chinese Academy of Sciences, Box 603, Beijing 100190, China 2London Centre for Nanotechnology & Department of Chemistry, University College London, London WC1H 0AJ, UK 3Department of Earth Sciences & Department of Physics and Astronomy & London Centre for Nanotechnology, London...

Hydrogen influence on diffusion in nickel from first-principles calculations

First-principles based modelling of ferroelectrics

The application of first-principles computational methods to the study of ferroelectric perovskites has greatly expanded our theoretical understanding of this important class of materials. These methods have most recently been applied to an increasingly wide range of ferroelectric materials, with special attention to their lattice dynamics, phase transitions, and dielectric and piezoelectric pr...

First-principles modelling of magnesium titanium hydrides.

Mixing Mg with Ti leads to a hydride Mg(x)Ti((1 - x))H(2) with markedly improved (de)hydrogenation properties for x ≤ 0.8, as compared to MgH(2). Optically thin films of Mg(x)Ti((1 - x))H(2) have a black appearance, which is remarkable for a hydride material. In this paper we study the structure and stability of Mg(x)Ti((1 - x))H(2), x = 0-1 by first-principles calculations at the level of dens...