4,243 research outputs found

    The contribution of ecological footprinting to planning policy development: using REAP to evaluate policies for sustainable housing construction

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    The complexity of the sustainable-development policy goal is such that policy makers are searching for tools to enable them to evaluate and develop policy directions. To date, ecological footprinting has been used mainly for raising awareness of environmental impacts but it also has considerable potential as a policy tool, enabling policy makers in their strategic work. The paper presents an application of a specific ecological footprinting development, the REAP (Resource and Energy Analysis Programme) tool, to a current policy issue, the promotion of sustainable construction. Using the London Plan of the Greater London Authority as a case study, it considers the strengths and weaknesses of this approach and how it can contribute to policy development

    An L^2-Index Theorem for Dirac Operators on S^1 * R^3

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    An expression is found for the L2L^2-index of a Dirac operator coupled to a connection on a UnU_n vector bundle over S1×R3S^1\times{\mathbb R}^3. Boundary conditions for the connection are given which ensure the coupled Dirac operator is Fredholm. Callias' index theorem is used to calculate the index when the connection is independent of the coordinate on S1S^1. An excision theorem due to Gromov, Lawson, and Anghel reduces the index theorem to this special case. The index formula can be expressed using the adiabatic limit of the η\eta-invariant of a Dirac operator canonically associated to the boundary. An application of the theorem is to count the zero modes of the Dirac operator in the background of a caloron (periodic instanton).Comment: 14 pages, Latex, to appear in the Journal of Functional Analysi

    Ab-initio elastic tensor of cubic Ti0.5_{0.5}Al0.5_{0.5}N alloy: the dependence of the elastic constants on the size and shape of the supercell model

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    In this study we discuss the performance of approximate SQS supercell models in describing the cubic elastic properties of B1 (rocksalt) Ti0.5_{0.5}Al0.5_{0.5}N alloy by using a symmetry based projection technique. We show on the example of Ti0.5_{0.5}Al0.5_{0.5}N alloy, that this projection technique can be used to align the differently shaped and sized SQS structures for a comparison in modeling elasticity. Moreover, we focus to accurately determine the cubic elastic constants and Zener's type elastic anisotropy of Ti0.5_{0.5}Al0.5_{0.5}N. Our best supercell model, that captures accurately both the randomness and cubic elastic symmetry, results in C11=447C_{11}=447 GPa, C12=158C_{12}=158 GPa and C44=203C_{44}=203 GPa with 3% of error and A=1.40A=1.40 for Zener's elastic anisotropy with 6% of error. In addition, we establish the general importance of selecting proper approximate SQS supercells with symmetry arguments to reliably model elasticity of alloys. In general, we suggest the calculation of nine elastic tensor elements - C11C_{11}, C22C_{22}, C33C_{33}, C12C_{12}, C13C_{13}, C23C_{23}, C44C_{44}, C55C_{55} and C66C_{66}, to evaluate and analyze the performance of SQS supercells in predicting elasticity of cubic alloys via projecting out the closest cubic approximate of the elastic tensor. The here described methodology is general enough to be applied in discussing elasticity of substitutional alloys with any symmetry and at arbitrary composition.Comment: Submitted to Physical Review

    Assessment into the usage of levetiracetam in a canine epilepsy clinic

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    The modalities of Iranian soft power: from cultural diplomacy to soft war

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    Through exploring Iran's public diplomacy at the international level, this article demonstrates how the Islamic Republic's motives should not only be contextualised within the oft-sensationalised, material or ‘hard’ aspects of its foreign policy, but also within the desire to project its cultural reach through ‘softer’ means. Iran's utilisation of culturally defined foreign policy objectives and actions demonstrates its understanding of soft power's potentialities. This article explores the ways in which Iran's public diplomacy is used to promote its soft power and craft its, at times, shifting image on the world stage

    Quantum effects in the evolution of vortices in the electromagnetic field

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    We analyze the influence of electron-positron pairs creation on the motion of vortex lines in electromagnetic field. In our approach the electric and magnetic fields satisfy nonlinear equations derived from the Euler-Heisenberg effective Lagrangian. We show that these nonlinearities may change the evolution of vortices.Comment: REVTEX4 and 5 EPS figure
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