29,547 research outputs found
Imaging the phase of an evolving Bose-Einstein condensate wavefunction
We demonstrate a spatially resolved autocorrelation measurement with a
Bose-Einstein condensate (BEC) and measure the evolution of the spatial profile
of its quantum mechanical phase. Upon release of the BEC from the magnetic
trap, its phase develops a form that we measure to be quadratic in the spatial
coordinate. Our experiments also reveal the effects of the repulsive
interaction between two overlapping BEC wavepackets and we measure the small
momentum they impart to each other
Labour Management for Profit and Welfare in Extensive Sheep Farming
Sheep welfare is an emerging topic in research and food marketing, and recent studies suggest that farm labour is a key factor for both animal welfare and productivity in extensive sheep farming systems, although little research has been done into labour utilisation in these systems. This paper reports field data collection on two commercial farms and the use of a linear programming (LP) model to link labour economics and animal welfare analysis. The model maximises the number of ewes to clooked after over the lambing period, when constrained by labour availability for various key tasks and by a pre-determined level of sheep welfare. The results show a trade-off between welfare level and labour input per sheep. Dropping tasks with less significant welfare and productivity consequences is an effective way of increasing carrying capacity (from 977 ewes/shepherd to 1428), as is working longer hours (1174 ewes/shepherd) or only doing the legal minimum of welfare checking (labour reduced from 0.68 min/ewe to 0.44 min/ewe) . The field data suggest that farmers currently provide high welfare, and that, despite much time spent away from the flock (e.g. driving), they spend a large amount of time (39% of total) with their sheep.Labour, Sheep, Linear Programming, Animal Welfare, Livestock Production/Industries, Q10, Q19, Y1,
Variable Conductance Heat Pipe Technology
A research and development program in variable conductance heat pipe technology is reported. The project involved: (1) theoretical and/or experimental studies in hydrostatics, (2) hydrodynamics, (3) heat transfer into and out of the pipe, (4) fluid selection, and (5) materials compatibility. The development, fabrication, and test of the space hardware resulted in a successful flight of the heat pipe experiment on the OAO-3 satellite. A summary of the program is provided and a guide to the location of publications on the project is included
Fundamental Oscillation Periods of the Interlayer Exchange Coupling beyond the RKKY Approximation
A general method for obtaining the oscillation periods of the interlayer
exchange coupling is presented. It is shown that it is possible for the
coupling to oscillate with additional periods beyond the ones predicted by the
RKKY theory. The relation between the oscillation periods and the spacer Fermi
surface is clarified, showing that non-RKKY periods do not bear a direct
correspondence with the Fermi surface. The interesting case of a FCC(110)
structure is investigated, unmistakably proving the existence and relevance of
non-RKKY oscillations. The general conditions for the occurrence of non-RKKY
oscillations are also presented.Comment: 34 pages, 10 figures ; to appear in J. Phys.: Condens. Mat
Ethical and compliance-competence evaluation: a key element of sound corporate governance
Motivated by the ongoing post-Enron refocusing on corporate governance and the shift by the Financial Services Authority (FSA) in the UK to promoting compliance- competence within the financial services sector, this paper demonstrates how template analysis can be used as a tool for evaluating compliance-competence. Focusing on the ethical dimension of compliance-competence, we illustrate how this can be subjectively appraised. We propose that this evaluation technique could be utilised as a starting point in informing senior management of corporate governance issues and be used to monitor and demonstrate key compliance and ethical aspects of an institution to external stakeholders and regulators
Spiral vortices traveling between two rotating defects in the Taylor-Couette system
Numerical calculations of vortex flows in Taylor-Couette systems with counter
rotating cylinders are presented. The full, time dependent Navier-Stokes
equations are solved with a combination of a finite difference and a Galerkin
method. Annular gaps of radius ratio and of several heights are
simulated. They are closed by nonrotating lids that produce localized Ekman
vortices in their vicinity and that prevent axial phase propagation of spiral
vortices. Existence and spatio temporal properties of rotating defects, of
modulated Ekman vortices, and of the spiral vortex structures in the bulk are
elucidated in quantitative detail.Comment: 9 pages, 9 figure
Numerical simulations on the 4d Heisenberg spin glass
We study the 4d Heisenberg spin glass model with Gaussian nearest-neighbor
interactions. We use finite size scaling to analyze the data. We find a
behavior consistent with a finite temperature spin glass transition. Our
estimates for the critical exponents agree with the results from
epsilon-expansion.Comment: 11 pages, LaTeX, preprint ROMA1 n. 105
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