17,909 research outputs found

    Resonance absolute quantum reflection at selected energies

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    The possibility of the resonance reflection (100 % at maximum) is revealed. The corresponding exactly solvable models with the controllable numbers of resonances, their positions and widths are presented.Comment: 5 pages, 2 figure

    NUTRITION CONSIDERATIONS IN FOOD SELECTION

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    The importance of nutrition consideration to households in food selection is instrumental in the development of information programs to promote public health and to market healthy food. Using a national telephone survey of 2880 U.S. households, this study examines the role and influence of socio-economic characteristics and lifestyle on a household meal plannerÂ’s consideration of four dietary components in food selection. Household income, children in households, geographic location, and gender, age, education, and lifestyle of meal planners affected the consideration of dietary components in food selection. The results provide a basis for developing education programs that focus on the particular dietary considerations of identified demographic subgroups.Food Consumption/Nutrition/Food Safety,

    RELATIVE AND ABSOLUTE RISK FORMAT IN ELICITING WILLINGNESS-TO-PAY FOR BEEF IRRADIATION

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    The relationship between the valuation of reduced risk through irradiation and framing of risk information was determined using absolute and relative risk formats. A double-bounded CV survey was used to measure willingness-to-pay (WTP) for irradiated beef among 740 U.S. households. Results show that the WTP was sensitive to the risk formats.beef irradiation, relative risk format, absolute risk format, willingness-to-pay, double-bounded CV questions, Consumer/Household Economics,

    Constitutional Aspects of Approval of Share Transactions

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    Perfect State Transfer: Beyond Nearest-Neighbor Couplings

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    In this paper we build on the ideas presented in previous works for perfectly transferring a quantum state between opposite ends of a spin chain using a fixed Hamiltonian. While all previous studies have concentrated on nearest-neighbor couplings, we demonstrate how to incorporate additional terms in the Hamiltonian by solving an Inverse Eigenvalue Problem. We also explore issues relating to the choice of the eigenvalue spectrum of the Hamiltonian, such as the tolerance to errors and the rate of information transfer.Comment: 8 pages, 2 figures. Reorganised, more detailed derivations provided and section on rate of information transfer adde

    Continuity of symplectically adjoint maps and the algebraic structure of Hadamard vacuum representations for quantum fields on curved spacetime

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    We derive for a pair of operators on a symplectic space which are adjoints of each other with respect to the symplectic form (that is, they are sympletically adjoint) that, if they are bounded for some scalar product on the symplectic space dominating the symplectic form, then they are bounded with respect to a one-parametric family of scalar products canonically associated with the initially given one, among them being its ``purification''. As a typical example we consider a scalar field on a globally hyperbolic spacetime governed by the Klein-Gordon equation; the classical system is described by a symplectic space and the temporal evolution by symplectomorphisms (which are symplectically adjoint to their inverses). A natural scalar product is that inducing the classical energy norm, and an application of the above result yields that its ``purification'' induces on the one-particle space of the quantized system a topology which coincides with that given by the two-point functions of quasifree Hadamard states. These findings will be shown to lead to new results concerning the structure of the local (von Neumann) observable-algebras in representations of quasifree Hadamard states of the Klein-Gordon field in an arbitrary globally hyperbolic spacetime, such as local definiteness, local primarity and Haag-duality (and also split- and type III_1-properties). A brief review of this circle of notions, as well as of properties of Hadamard states, forms part of the article.Comment: 42 pages, LaTeX. The Def. 3.3 was incomplete and this has been corrected. Several misprints have been removed. All results and proofs remain unchange

    ANALYSIS OF CONSUMER ATTITUDES TOWARD NEW FRIED FOOD PREPARED FROM COWPEA FLOUR

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    American consumers are exposed to thousands of new food products on supermarket shelves each year. For new products, such as akara products, it is crucial to determine consumer preferences and buying intentions. In this study, 346 randomly selected consumers were surveyed to reveal their preference for five akara products prepared from cowpea flour. Preference data were analyzed through use of a multi-ordered response model. Model results indicate that socio-demographic factors were weakly linked to explaining consumer preferences while product characteristics were much more important in preference considerations.Consumer/Household Economics,

    Prevalence of sulfonamide resistance genes in bacterial isolates from manured agricultural soils and pig slurry in the United Kingdom

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    Prevalence of three sulfonamide resistance genes, sul1, sul2 and sul3 and sulfachloropyridazine (SCP) resistance was determined in bacteria isolated from UK manured agricultural clay soils and slurry samples, over a two year period. Slurry from tylosin-fed pigs amended with SCP and oxytetracycline (OTC) was used for manuring. Sul gene positive isolates were further screened for the presence of class 1 and 2 integrons. Phenotypic resistance to SCP was significantly higher in pig slurry and post application soil than in pre-application soil. Of 5isolates, 23 % carried sul1, 18 % sul2 and 9 % sul3 only. Two percent of isolates contained all three sul genes. Class 1 and class 2 integrons were identified in 5 % and 11.7 % of sul positive isolates. In previous reports, sul1 was linked to class 1 integrons, but in this study only 8 % of sul1 positive isolates carried the intI1 gene. Sulfonamide resistant pathogens were identified in slurry amended soil and soil leachate, including Shigella flexneri, Aerococcus spp. and Acinetobacter baumanni, suggesting a potential environmental reservoir. Sulfonamide resistance in Psychrobacter, Enterococcus and Bacillus spp. is reported for the first time, and this study also provides the first description of the genotype sul1, sul2 and sul3 outside the Enterobacteriacae, and in the soil environment

    Optimization of Flapping Airfoils for Maximum Thrust and Propulsive Efficiency

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    A numerical optimization algorithm based on the steepest decent along the variation of the optimization function is implemented for maximizing the thrust and/or propulsive efficiency of a single flapping airfoil. Unsteady, low speed laminar flows are computed using a Navier-Stokes solver on moving overset grids. The flapping motion of the airfoil is described by a combined sinusoidal plunge and pitching motion. Optimization parameters are taken to be the amplitudes of the plunge and pitching motions, and the phase shift between them. Computations are performed in parallel in a work station cluster. The numerical simulations show that high thrust values may be obtained at the expense of reduced efficiency. For high efficiency in thrust generation, the induced angle of attack of the airfoil is reduced and large scale vortex formations at the leading edge are prevented.
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