9,675 research outputs found

    Theater Air Forces

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    This morning I shall discuss the principles and doctrines of Air Force combat units in the role of support in a theater campaign. During the past several years you will remember the controversies going around Washington and the Pentagon about air power, Sim­ilarly, I know most of you, at one time or another, have participated in friendly arguments as to which system, the Navy, or the Air Force was the most effective. From my experience and study of the principles and doctrine of the use of air power in a combat theater, I can see no important difference

    Boundary changing operators in the O(n) matrix model

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    We continue the study of boundary operators in the dense O(n) model on the random lattice. The conformal dimension of boundary operators inserted between two JS boundaries of different weight is derived from the matrix model description. Our results are in agreement with the regular lattice findings. A connection is made between the loop equations in the continuum limit and the shift relations of boundary Liouville 3-points functions obtained from Boundary Ground Ring approach.Comment: 31 pages, 4 figures, Introduction and Conclusion improve

    Self-organized metal nanostructures through laser driven thermocapillary convection

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    When ultrathin metal films are subjected to multiple cycles of rapid melting and resolidification by a ns pulsed laser, spatially correlated interfacial nanostructures can result from a competition among several possible thin film self-organizing processes. Here we investigate self-organization and the ensuing length scales when Co films (1-8 nm thick) on SiO_{\text{2}} surfaces are repeatedly and rapidly melted by non-uniform (interference) laser irradiation. Pattern evolution produces nanowires, which eventually break-up into nanoparticles exhibiting spatial order in the nearest neighbor spacing, \lambda_{NN2}.The scaling behavior is consistent with pattern formation by thermocapillary flow and a Rayleigh-like instability. For h_{0}\leq2 nm, a hydrodynamic instability of a spinodally unstable film leads to the formation of nanoparticles.Comment: 10 pages, 3 figure

    Health, Climate Change and Energy Vulnerability: A Retrospective Assessment of Strategic Health Authority Policy and Practice in England

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    Background: A number of policy documents suggest that health services should be taking climate change and sustainability seriously and recommendations have been made to mitigate and adapt to the challenges health care providers will face. Actions include, for example, moving towards locally sourced food supplies, reducing waste, energy consumption and travel, and including sustainability in policies and strategies. A Strategic Health Authority (SHA) is part of the National Health Service (NHS) in England. They are responsible for developing strategies for the local health services and ensuring high-quality performance. They manage the NHS locally and are a key link between the U.K. Department of Health and the NHS. They also ensure that national priorities are integrated into local plans. Thus they are in a key position to influence policies and practices to mitigate and adapt to the impact of climate change and promote sustainability.Aim: The aim of this study was to review publicly available documents produced by Strategic Health Authorities (SHA) to assess the extent to which current activity and planning locally takes into consideration climate change and energy vulnerability.Methods: A retrospective thematic content analysis of publicly available materials was undertaken by two researchers over a six month period in 2008. These materials were obtained from the websites of the 10 SHAs in England. Materials included annual reports, plans, policies and strategy documents.Results: Of the 10 SHAs searched, 4 were found to have an absence of content related to climate change and sustainability. Of the remaining 6 SHAs that did include content related to climate change and energy vulnerability on their websites consistent themes were seen to emerge. These included commitment to a regional sustainability framework in collaboration with other agencies in the pursuit and promotion of sustainable development.Results indicate that many SHAs in England have yet to embrace sustainability, or to integrate preparations for climate change and energy vulnerability within their organisational strategies. Evidence also suggests that SHAs that have recognised the importance of sustainability within their documentation and policies have yet to fully demonstrate this in practice through the implementation of these policies.Conclusions: Further research is required to investigate means by which SHAs (U.K.) and agencies responsible for health service policy in other countries may be enabled to include a greater consideration of sustainability and climate change within their policies, and to find effective ways of implementing these policies within daily working practice

    Equivalences between spin models induced by defects

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    The spectrum of integrable spin chains are shown to be independent of the ordering of their spins. As an application we introduce defects (local spin inhomogeneities in homogenous chains) in two-boundary spin systems and, by changing their locations, we show the spectral equivalence of different boundary conditions. In particular we relate certain nondiagonal boundary conditions to diagonal ones.Comment: 14 pages, 16 figures, LaTeX, Extended versio

    Low temperature shape relaxation of 2-d islands by edge diffusion

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    We present a precise microscopic description of the limiting step for low temperature shape relaxation of two dimensional islands in which activated diffusion of particles along the boundary is the only mechanism of transport allowed. In particular, we are able to explain why the system is driven irreversibly towards equilibrium. Based on this description, we present a scheme for calculating the duration of the limiting step at each stage of the relaxation process. Finally, we calculate numerically the total relaxation time as predicted by our results and compare it with simulations of the relaxation process.Comment: 11 pages, 5 figures, to appear in Phys. Rev.

    Structure of the two-boundary XXZ model with non-diagonal boundary terms

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    We study the integrable XXZ model with general non-diagonal boundary terms at both ends. The Hamiltonian is considered in terms of a two boundary extension of the Temperley-Lieb algebra. We use a basis that diagonalizes a conserved charge in the one-boundary case. The action of the second boundary generator on this space is computed. For the L-site chain and generic values of the parameters we have an irreducible space of dimension 2^L. However at certain critical points there exists a smaller irreducible subspace that is invariant under the action of all the bulk and boundary generators. These are precisely the points at which Bethe Ansatz equations have been formulated. We compute the dimension of the invariant subspace at each critical point and show that it agrees with the splitting of eigenvalues, found numerically, between the two Bethe Ansatz equations.Comment: 9 pages Latex. Minor correction

    Drip cooling of lactating sows

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    Twenty eight sows and gilts were used to evaluate the value of drip sprinkling to reduce heat stress in lactating sows. Respiration rates for sprinkled sows were significantly lower than those of controls. Daily feed intake was significantly higher for wetted sows versus the unwetted controls. No differences were observed between groups on number of pigs born alive, dead, number weaned or pig birth weight.; Swine Day, Manhattan, KS, November 10, 198
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