25,457 research outputs found

    Defining the Debate on Controlling Biological Weapons

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    Looks at the 1972 Biological and Toxins Weapons Convention, and outlines the series of measures being negotiated by the world community to create a strong, effective, and enforceable biological weapons treaty

    Properties of periodic arrays of symmetric complementary structuresand their application to grid amplifiers

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    Deschamps' theorem for n-terminal complementary structures is reviewed. An extension to Deschamps' theorem for a class of three-terminal bounded structures with one axis of symmetry is presented. It is shown that, for these structures, a simple relationship between the impedances of the odd mode of the original structure and the admittances of the even mode of the complementary structure exists, and that these modes are orthogonal. Using this, a self-complementary grid amplifier is designed and the measured results are presented

    Self-Complementary Structures and Their Application in Grid Amplifiers

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    An extension to Deschamps’s theorem for a class of 3-terminal bounded structures with one axis of symmetry is presented. For these structures, a simple relationship between the impedance matrix of the odd mode excitation of the original structure and the admittance matrix of the even mode excitation of its complement exists. Using this, a self-complementary grid amplifier is designed and the measured results are presented

    Carbon deposition model for oxygen-hydrocarbon combustion. Task 6: Data analysis and formulation of an empirical model

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    The formation and deposition of carbon (soot) was studied in the Carbon Deposition Model for Oxygen-Hydrocarbon Combustion Program. An empirical, 1-D model for predicting soot formation and deposition in LO2/hydrocarbon gas generators/preburners was derived. The experimental data required to anchor the model were identified and a test program to obtain the data was defined. In support of the model development, cold flow mixing experiments using a high injection density injector were performed. The purpose of this investigation was to advance the state-of-the-art in LO2/hydrocarbon gas generator design by developing a reliable engineering model of gas generator operation. The model was formulated to account for the influences of fluid dynamics, chemical kinetics, and gas generator hardware design on soot formation and deposition

    Application of remote sensing in estimating evapotranspiration in the Platte river basin

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    A 'resistance model' and a mass transport model for estimating evapotranspiration (ET) were tested on large fields of naturally subirrigated alfalfa. Both models make use of crop canopy temperature data. Temperature data were obtained with an IR thermometer and with leaf thermocouples. A Bowen ratio-energy balance (BREB) model, adjusted to account for underestimation of ET during periods of strong sensible heat advection, was used as the standard against which the resistance and mass transport models were compared. Daily estimates by the resistance model were within 10% of estimates made by the BREB model. Daily estimates by the mass transport model did not agree quite as well. Performance was good on clear and cloudy days and also during periods of non-advection and strong advection of sensible heat. The performance of the mass transport and resistance models was less satisfactory for estimation of fluxes of latent heat for short term periods. Both models tended to overestimate at low LE fluxes

    Welfare Effects of UzbekistanĂ­s Foreign Exchange Regime

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    In addition to transferring about 16 percent of GDP from exporters to importers, UzbekistanĂ­s quasi-fiscal multiple exchange rate regime generates identifiable welfare losses of 2-8 percent of GDP on import markets and up to 15 percent on export markets. These excess burdens have increased substantially with the growing difference among exchange rates. The welfare analysis allows some conclusions regarding the optimal reform strategy: (i) welfare losses will decline overproportionally as exchange rates unify, (ii) exchange rate unification should be supplemented by changing the explicit fiscal system; (iii) at a minimum, Uzbekistan would benefit from moving to an explicit fiscal regime. Copyright 2001, International Monetary Fund

    Identification and evaluation of linear damping models in beam vibrations

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    Sensitive method, identifying effective damping mechanisms, involves comparing experimentally determined ratio of first to second mode magnification factors related to common point on beam. Cluster size has little effect on frequencies of elements, magnification factor decreases with cluster size, and viscous and stress damping are dominant damping mechanisms

    The index of projective families of elliptic operators

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    An index theory for projective families of elliptic pseudodifferential operators is developed. The topological and the analytic index of such a family both take values in twisted K-theory of the parametrizing space, X. The main result is the equality of these two notions of index when the twisting class is in the torsion subgroup of H^3(X;Z). The Chern character of the index class is then computed.Comment: Published by Geometry and Topology at http://www.maths.warwick.ac.uk/gt/GTVol9/paper11.abs.htm

    Height Discrimination in Employment

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    This Article looks critically at heightism, i.e., prejudice or discrimination against a person on the basis of his or her height. Although much scholarship has focused on other forms of trait-based discrimination—most notably weight and appearance discrimination, both of which indirectly involve height as a component—little has focused on “pure” height discrimination. Nevertheless, within the past five years courts, scholars, and legislatures have increasingly tackled these non-traditional forms of discrimination. As such, this Article endeavors to fill the gap in the existing scholarship. This Article specifically focuses on heightism in the workplace, with an emphasis on prejudice against short people because of the unique disadvantages they face vis-à-vis their taller counterparts. It examines the ways that existing federal antidiscrimination laws—namely Title VII of the Civil Rights Act of 1964 and the Americans with Disabilities Act of 1990—do and do not protect against height-based prejudice in the workplace. Moreover, after briefly examining state and local remedies for height discrimination, including state antidiscrimination laws, this Article considers but ultimately rejects enacting a federal law that would flatly prohibit all height-based employment decisions. Although a comprehensive prohibition would be easiest to administer, such a prohibition would prove both gratuitous and unwise. Instead, this Article recommends modest changes to federal regulations and increased state and local enforcement
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