Contributions of Vacuum and Plasmon Modes to the Force on a Small Sphere near a Plate

The force on a small sphere with a plasma model dielectric function and in the presence of a perfectly reflecting plane is considered. The contribution of both the vacuum modes of the quantized electromagnetic field and of plasmon modes in the sphere are discussed. In the case that the plasmon modes are in their ground state, quasi-oscillatory terms from the vacuum and plasmon parts cancel one another, leading a monotonic attractive force. If the plasmon modes are not in the ground state, the net force is quasi-oscillatory. In both cases, the sphere behaves in the same way as does an atom in either its ground state or an excited state.Comment: 7 pages, no figures, talk presented at "Quantum Fields under External Conditions - 2005", Barcelona, Spain, September 200

Apollo oxygen tank stratification analysis, volume 2

An analysis of flight performance of the Apollo 15 cryogenic oxygen tanks was conducted with the variable grid stratification math model developed earlier in the program. Flight conditions investigated were the CMP-EVA and one passive thermal control period which exhibited heater temperature characteristics not previously observed. Heater temperatures for these periods were simulated with the math model using flight acceleration data. Simulation results (heater temperature and tank pressure) compared favorably with the Apollo 15 flight data, and it was concluded that tank performance was nominal. Math model modifications were also made to improve the simulation accuracy. The modifications included the addition of the effects of the tank wall thermal mass and an improved system flow distribution model. The modifications improved the accuracy of simulated pressure response based on comparisons with flight data

Convergence and divergence dynamics in British and French business schools: how will the pressure for accreditation influence these dynamics?

This paper focuses on convergence and divergence dynamics among leading British and French business schools and explores how the pressure for accreditation influences these dynamics. We illustrate that despite historical differences in approaches to management education in Britain and France, these approaches have converged partly based on the influence of the American model of management education but more recently through the pursuit of accreditation, in particular AASCB and EQUIS. We explore these dynamics through the application of the resource-based view of the firm and institutional theory and suggest that whilst achieving accreditation is a necessary precursor for international competition, it is no longer a form of competitive advantage. The pursuit of accreditation has fostered a form of competitive mimicry reducing national distinctiveness. The resource-based view of the firm suggests that the top schools need a more heterogeneous approach that is not easily replicable if they are to outperform the competitors. Consequently, the convergence of management education in Britain and France will become a new impetus for divergence. We assert that future growth and competitive advantage might be better achieved through the reassertion of national, regional and local cultural characteristics

Coalescent simulation in continuous space:Algorithms for large neighbourhood size

Many species have an essentially continuous distribution in space, in which there are no natural divisions between randomly mating subpopulations. Yet, the standard approach to modelling these populations is to impose an arbitrary grid of demes, adjusting deme sizes and migration rates in an attempt to capture the important features of the population. Such indirect methods are required because of the failure of the classical models of isolation by distance, which have been shown to have major technical flaws. A recently introduced model of extinction and recolonisation in two dimensions solves these technical problems, and provides a rigorous technical foundation for the study of populations evolving in a spatial continuum. The coalescent process for this model is simply stated, but direct simulation is very inefficient for large neighbourhood sizes. We present efficient and exact algorithms to simulate this coalescent process for arbitrary sample sizes and numbers of loci, and analyse these algorithms in detail

Computational Efficiency of Frequency-- and Time--Domain Calculations of Extreme Mass--Ratio Binaries: Equatorial Orbits

Gravitational waveforms and fluxes from extreme mass--ratio inspirals can be computed using time--domain methods with accuracy that is fast approaching that of frequency--domain methods. We study in detail the computational efficiency of these methods for equatorial orbits of fast spinning Kerr black holes, and find the number of modes needed in either method --as functions of the orbital parameters-- in order to achieve a desired accuracy level. We then estimate the total computation time and argue that for high eccentricity orbits the time--domain approach is more efficient computationally. We suggest that in practice low--$m$ modes are computed using the frequency--domain approach, and high--$m$ modes are computed using the time--domain approach, where $m$ is the azimuthal mode number.Comment: 19 figures, 6 table

Experience and Assessment of the DOE/NASA Mod-1 2000 Kw Wind Turbine Generator at Boone, North Carolina

The Mod 1 program objectives are defined. The Mod 1 wind turbine is described. In addition to the steel blade operated on the wind turbine, a composite blade was designed and manufactured. During the early phase of the manufacturing cycle of Mod 1A configuration was designed that identified concepts such as partial span control, a soft tower, and upwind teetered rotors that were incorporated in second and third generation industry designs. The Mod 1 electrical system performed as designed, with voltage flicker characteristics within acceptable utility limits

Scattering of quantum wave packets by shallow potential islands: a quantum lens

We consider the problem of quantum scattering of a localized wave packet by a weak Gaussian potential in two spatial dimensions. We show that, under certain conditions, this problem bears close analogy with that of focusing (or defocusing) of light rays by a thin optical lens: Quantum interference between straight paths yields the same lens equation as for refracted rays in classical optics

Strain monitoring of tapestries: results of a three-year research project

The outcomes of an interdisciplinary research project between conservators and engineers investigating the strain experienced by different areas of a tapestry are described. Two techniques were used: full-field monitoring using digital image correlation (DIC) and point measurements using optical fibre sensors. Results showed that it is possible to quantify the global strain across a discrete area of a tapestry using DIC; optical fibre and other sensors were used to validate the DIC. Strain maps created by the DIC depict areas of high and low strain and can be overlaid on images of the tapestry, creating a useful visual tool for conservators, custodians and the general public. DIC identifies areas of high strain not obvious to the naked eye. The equipment can be used in situ in a historic house. In addition the work demonstrated the close relationship between relative humidity and strain

Greenstone belts: Their components and structure

Greenstone sucessions are defined as the nongranitoid component of granitoid-greenstone terrain and are linear to irregular in shape and where linear are termed belts. The chemical composition of greenstones is described. Also discussed are the continental environments of greenstone successions. The effects of contact with granitoids, geophysical properties, recumbent folds and late formation structures upon greenstones are examined. Large stratigraphy thicknesses are explained