8,491 research outputs found

    Priorities for sustainable turfgrass management: a research and industry perspective

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    This paper provides a brief review and assessment of the key environmental, regulatory and technical issues facing the turfgrass sector with specific reference to the European context. It considers the range of externalities or ‘drivers for change' facing the industry, and the challenges and opportunities available for promoting and achieving more sustainable turfgrass management within the sports, landscape and amenity sectors. The analysis confirms that there are a number of key areas where a concerted research and industrial effort is required. These include responding to the pressures from government demands for greater environmental regulation, the increasing pressure on natural resources (notably water, energy and land), the emerging role of turf management in supporting ecosystem services and enhancing biodiversity, the continued need to promote integrated pest management, and the looming challenges posed by a changing climate, and urgent need to adapt. Whilst many of these externalities appear to be risks to the sports turf industry, there will also be significant opportunities, for those where the labour, energy and agronomic costs are minimized and where the drive to adopt a multifunctional approach to sportsturf management is embraced

    PROCUREMENT STRATEGIES TO MEET FUNCTIONAL REQUIREMENTS IN WHEAT SHIPMENTS

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    Consistency of functional characteristics in wheat is a concern confronting buyers and sellers. This research analyzes the cost and risk of different procurement strategies for importers. A stochastic simulation model is used to determine the probability of a functional characteristic being satisfied subject to quality targets. Joint probabilities of meeting specifications and costs were determined for alternative functional characteristics. Results indicate that, as more specific characteristics are incorporated into a contract, the probabilities of meeting end-use requirements increase. Specific characteristics come with a higher cost, due to increased testing costs related to identity preservation. The results are summarized as cost/risk tradeoffs confronting buyers in wheat procurement.buying strategies, location, variety, functional characteristic tests, costs, risks, Crop Production/Industries, International Relations/Trade,

    HUMAN RIGHTS AND THE GENEVA CONVENTIONS

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    Today, there are two distinct bodies of law namely Human Rights Law and International Law of Armed Conflict. The latter often referred to as International Humanitarian Law, since it aims at reducing suffering during armed conflict. The Geneva Conventions of 1949 have a prominent place within International Law of Armed Conflict. It is also important, because the biggest part of International Law of Armed Conflict is regulated in these Conventions. Although there is close relation between the two bodies of law, but there are some differences, in particular, in applicability of its norms. Human Rights Law applicable in peacetime while International Law of Armed Conflict applicable in wartime. This article explains those issues in brief

    Invertible Dirac operators and handle attachments on manifolds with boundary

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    For spin manifolds with boundary we consider Riemannian metrics which are product near the boundary and are such that the corresponding Dirac operator is invertible when half-infinite cylinders are attached at the boundary. The main result of this paper is that these properties of a metric can be preserved when the metric is extended over a handle of codimension at least two attached at the boundary. Applications of this result include the construction of non-isotopic metrics with invertible Dirac operator, and a concordance existence and classification theorem.Comment: Accepted for publication in Journal of Topology and Analysi

    Dilaton-Axion hair for slowly rotating Kerr black holes

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    Campbell et al. demonstrated the existence of axion ``hair'' for Kerr black holes due to the non-trivial Lorentz Chern-Simons term and calculated it explicitly for the case of slow rotation. Here we consider the dilaton coupling to the axion field strength, consistent with low energy string theory and calculate the dilaton ``hair'' arising from this specific axion source.Comment: 13 pages + 1 fi

    Mapping the Wigner distribution function of the Morse oscillator into a semi-classical distribution function

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    The mapping of the Wigner distribution function (WDF) for a given bound-state onto a semiclassical distribution function (SDF) satisfying the Liouville equation introduced previously by us is applied to the ground state of the Morse oscillator. Here we give results showing that the SDF gets closer to the corresponding WDF as the number of levels of the Morse oscillator increases. We find that for a Morse oscillator with one level only, the agreement between the WDF and the mapped SDF is very poor but for a Morse oscillator of ten levels it becomes satisfactory.Comment: Revtex, 27 pages including 13 eps figure

    Determination of electromagnetic medium from the Fresnel surface

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    We study Maxwell's equations on a 4-manifold where the electromagnetic medium is described by an antisymmetric (22)2\choose 2-tensor Îș\kappa. In this setting, the Tamm-Rubilar tensor density determines a polynomial surface of fourth order in each cotangent space. This surface is called the Fresnel surface and acts as a generalisation of the light-cone determined by a Lorentz metric; the Fresnel surface parameterises electromagnetic wave-speed as a function of direction. Favaro and Bergamin have recently proven that if Îș\kappa has only a principal part and if the Fresnel surface of Îș\kappa coincides with the light cone for a Lorentz metric gg, then Îș\kappa is proportional to the Hodge star operator of gg. That is, under additional assumptions, the Fresnel surface of Îș\kappa determines the conformal class of Îș\kappa. The purpose of this paper is twofold. First, we provide a new proof of this result using Gr\"obner bases. Second, we describe a number of cases where the Fresnel surface does not determine the conformal class of the original (22)2\choose 2-tensor Îș\kappa. For example, if Îș\kappa is invertible we show that Îș\kappa and Îș−1\kappa^{-1} have the same Fresnel surfaces.Comment: 23 pages, 1 figur
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