7,459 research outputs found

    A Method for Broad-Scale Environmental Evaluation as Applied in an Environmental Analysis of Central Ohio

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    Author Institution: Ohio Biological SurveyA general but comprehensive environmental analysis of the environmental resources of a large region may be conducted utilizing an analysis/index matrix and maps of the analyzed resources. This methodology, previously applied to the 10,976 square mile Central Ohio Water Development Region, incorporates ecologically sound data in a format intelligible to decision makers. Resource maps of the region were completed with features rated, where possible, according to relative significance. Two gridded, summary, composite maps, one for natural components and one for human components, were then compiled. Each grid cell on the natural composite map indexes the significant features in that cell and the land use analog of the ecological serai stage (one of four categories) predominant in that cell. The analog is a comprehensive indicator of the relative degree of natural ecological integrity in the cell. Each grid cell on the human composite map indexes the significant features in that cell and the fair market land value category (one of four categories) predominant in the cell. The land value category is a comprehensive indicator of the human value attributed to that area. The two values for each grid cell on both composite maps are inserted into an analysis/index matrix to yield one of three final analysis/index values. These values, one from a natural perspective and one from a human perspective, indicate areas of overall, relative environmental importance. The natural and the human composite maps may be combined to indicate the areas of potential conflict and tradeoff between these two value systems

    The politics of punishment in colonial Mauritius, 1766-1887

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    The history of imprisonment in British colonial Mauritius is intertwined with its political economy, most especially the relationship between metropolitan government and plantation owners. Whether labour was predominantly enslaved, apprenticed or indentured, incarceration was part of a broader process through which the regulation of the colonial workforce was taken from the private to the public sphere and became associated with economic development. Nevertheless, prisoners both challenged and used prison regimes as vehicles for the improvement of their lives. Mauritian jails were intensely political arenas in which the changing nature of colonial relations and the regulation of labour was both expressed and contested

    Spacetime Groups

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    A spacetime group is a connected 4-dimensional Lie group G endowed with a left invariant Lorentz metric h and such that the connected component of the isometry group of h is G itself. The Newman-Penrose formalism is used to give an algebraic classification of spacetime groups, that is, we determine a complete list of inequivalent spacetime Lie algebras, which are pairs, (g, n), with g being a 4-dimensional Lie algebra and n being a Lorentzian inner product on g. A full analysis of the equivalence problem for spacetime Lie algebras is given which leads to a completely algorithmic solution to the problem of determining when two spacetime Lie algebras are isomorphic. The utility of our classification is demonstrated by a number of applications. The results of a detailed study of the Einstein field equations for various matter fields on spacetime groups are given, which resolve a number of open cases in the literature. The possible Petrov types of spacetime groups that, generically, are algebraically special are completely characterized. Several examples of conformally Einstein spacetime groups are exhibited. Finally, we describe some novel features of a software package created to support the computations and applications of this paper

    Three-Dimensional Spin-Orbit Coupling in a Trap

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    We investigate the properties of an atom under the influence of a synthetic three-dimensional spin-orbit coupling (Weyl coupling) in the presence of a harmonic trap. The conservation of total angular momentum provides a numerically efficient scheme for finding the spectrum and eigenfunctions of the system. We show that at large spin-orbit coupling the system undergoes dimensional reduction from three to one dimension at low energies, and the spectrum is approximately Landau level-like. At high energies, the spectrum is approximately given by the three-dimensional isotropic harmonic oscillator. We explore the properties of the ground state in both position and momentum space. We find the ground state has spin textures with oscillations set by the spin-orbit length scale

    The DifferentialGeometry Package

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    This is the entire DifferentialGeometry package, a zip file (DifferentialGeometry.zip) containing (1) a Maple Library file, DifferentialGeometryUSU.mla, (2) a Maple help file DifferentialGeometry.help, (3) a Maple Library file, DGApplicatons.mla. This is the latest version of the DifferentialGeometry software; it supersedes what is released with Maple. Installation instruction

    A New Non-Inheriting Homogeneous Solution of the Einstein-Maxwell Equations with Cosmological Term

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    We find a new homogeneous solution to the Einstein-Maxwell equations with a cos- mological term. The spacetime manifold is R Ă— S3. The spacetime metric admits a simply transitive isometry group G = R Ă— SU(2) and is Petrov type I. The spacetime is geodesically complete and globally hyperbolic. The electromagnetic field is non- null and non-inheriting: it is only invariant with respect to the SU(2) subgroup and is time-dependent in a stationary reference frame

    The Principle of Symmetric Criticality in General Relativity

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    We consider a version of Palais' Principle of Symmetric Criticality (PSC) that is applicable to the Lie symmetry reduction of Lagrangian field theories. PSC asserts that, given a group action, for any group-invariant Lagrangian the equations obtained by restriction of Euler-Lagrange equations to group-invariant fields are equivalent to the Euler-Lagrange equations of a canonically defined, symmetry-reduced Lagrangian. We investigate the validity of PSC for local gravitational theories built from a metric. It is shown that there are two independent conditions which must be satisfied for PSC to be valid. One of these conditions, obtained previously in the context of transverse symmetry group actions, provides a generalization of the well-known unimodularity condition that arises in spatially homogeneous cosmological models. The other condition seems to be new. The conditions that determine the validity of PSC are equivalent to pointwise conditions on the group action alone. These results are illustrated with a variety of examples from general relativity. It is straightforward to generalize all of our results to any relativistic field theory.Comment: 46 pages, Plain TeX, references added in revised versio

    Dehydration studies on bovine spermatozoa

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    This bulletin reports on Department of Dairy Husbandry Research Project 54, Artificial Insemination--P. [2].Digitized 2007 AES.Includes bibliographical references (page 35)
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