Spinor model of a perfect fluid and their applications in Bianchi type-I and FRW models

Different characteristic of matter influencing the evolution of the Universe has been simulated by means of a nonlinear spinor field. Exploiting the spinor description of perfect fluid and dark energy evolution of the Universe given by an anisotropic Bianchi type-I (BI) or isotropic Friedmann-Robertson-Walker (FRW) one has been studied.Comment: 10 pages, 8 Figure

Ultrahard Multilayer Coatings

We have developed a new multilayer a-tC material that is thick stress-free, adherent, low friction, and with hardness and stiffness near that of diamond. The new a-tC material is deposited by J pulsed-laser deposition (PLD) at room temperature, and fully stress-relieved by a short thermal anneal at 600°C. A thick multilayer is built up by repeated deposition and annealing steps. We measured 88 GPa hardness, 1100 GPa Young's modulus, and 0.1 friction coefficient (under high load). Significantly, these results are all well within the range reported for crystalline diamond. In fact, this material, if considered separate from crystalline diamond, is the 2nd hardest material known to man. Stress-free a-tC also has important advantages over thin film diamond; namely, it is smooth, processed at lower temperature, and can be grown on a much broader range of substrates. This breakthrough will enable a host of applications that we are actively pursuing in MEMs, sensors, LIGA, etc

URBAN FIELDS IN THE MAKING: NEW EVIDENCE FROM A DANISH CONTEXT

This paper analyses the development of the scale of spatial interaction in Denmark and its consequences for commute patterns around the country's two largest cities. The methods used are GIS-based mapping of commuter flows and analysis of the changing correlation between centrality and commuting from 1982 to 2002. The distances bridged by commuting and the size of functional regions have expanded markedly. The consequences for commute patterns depend on the regional context. In the case of the capital area, the expanding scale of interaction is equivalent to an expanded commuter field around the capital. The significance of the centre of the capital for commuting has increased from 1982 to 2002. In the case of East Jutland, where many mid-sized historical centres are located close to each other, the development is in the direction of a polycentric urban region with decreased significance of any single centre in attracting and focusing the commute pattern. Copyright (c) 2005 by the Royal Dutch Geographical Society KNAG.