3,441 research outputs found

    Faculty Recital:Jeffrey A. Gray, bass trombone

    Get PDF

    SEAFOOD SAFETY PERCEPTIONS AND THEIR EFFECTS ON ANTICIPATED CONSUMPTION UNDER VARYING INFORMATION TREATMENTS

    Get PDF
    This paper identifies factors that influence consumers' seafood safety perceptions and examines how these perceptions affect consumers' anticipated consumption when consumers are provided with additional information relevant to seafood. A recursive system of equations is specified describing consumers' safety perceptions as a function of past experience with seafood, recreational harvest activities, and risk-taking behavior, and describing the influence of safety perceptions on consumers' anticipated demand response to hypothetical information concerning seafood. A telephone survey of randomly selected Rhode Island consumers provided data for the analysis.Food Consumption/Nutrition/Food Safety,

    Calculating Nonlocal Optical Properties of Structures with Arbitrary Shape

    Full text link
    In a recent Letter [Phys. Rev. Lett. 103, 097403 (2009)], we outlined a computational method to calculate the optical properties of structures with a spatially nonlocal dielectric function. In this Article, we detail the full method, and verify it against analytical results for cylindrical nanowires. Then, as examples of our method, we calculate the optical properties of Au nanostructures in one, two, and three dimensions. We first calculate the transmission, reflection, and absorption spectra of thin films. Because of their simplicity, these systems demonstrate clearly the longitudinal (or volume) plasmons characteristic of nonlocal effects, which result in anomalous absorption and plasmon blueshifting. We then study the optical properties of spherical nanoparticles, which also exhibit such nonlocal effects. Finally, we compare the maximum and average electric field enhancements around nanowires of various shapes to local theory predictions. We demonstrate that when nonlocal effects are included, significant decreases in such properties can occur.Comment: 30 pages, 12 figures, 1 tabl

    ECONOMICS OF VARIABLE RATE NEMATICIDE FOR SUGAR BEETS

    Get PDF
    The benefit of applying fumigant for control of the sugar beet nematode on a variable versus uniform rate basis is examined. Compared to fumigating an entire filed at a constant full-label rate, varialbe rate application provides a savings ranging from 31/ac(heavilyinfestedfield)to31/ac (heavily infested field) to 69/ac (lightly infested field).Crop Production/Industries,

    Gating NO Release from Nitric Oxide Synthase

    Get PDF
    We have investigated the kinetics of NO escape from Geobacillus stearothermophilus nitric oxide synthase (gsNOS). Previous work indicated that NO release was gated at position 223 in mammalian enzymes; our kinetics experiments include mutants at that position along with measurements on the wild type enzyme. Employing stopped-flow UV–vis methods, reactions were triggered by mixing a reduced enzyme/N-hydroxy-l-arginine complex with an aerated buffer solution. NO release kinetics were obtained for wt NOS and three mutants (H134S, I223V, H134S/I223V). We have confirmed that wt gsNOS has the lowest NO release rate of known NOS enzymes, whether bacterial or mammalian. We also have found that steric clashes at positions 223 and 134 hinder NO escape, as judged by enhanced rates in the single mutants. The empirical rate of NO release from the gsNOS double mutant (H134/I223V) is nearly as rapid as that of the fastest mammalian enzymes, demonstrating that both positions 223 and 134 function as gates for escape of the product diatomic molecule

    LIF AND RAMAN SPECTROSCOPY IN UNDERGRADUATE LABS USING GREEN DIODE-PUMPED SOLID-STATE LASERS

    Get PDF
    Electronic spectroscopy of molecular iodine vapor has long been studied in undergraduate physical chemistry teaching laboratories, but the effectiveness of emission work has typically been limited by availability of instrumentation. This talk shows how to make inexpensive green diode-pumped solid-state (DPSS) lasers easily tunable for efficient, selective excitation of I2_{2}. Miniature fiber-optic spectrometers then enable rotationally resolved fluorescence spectroscopy up to v" = 42 near 900 nm with acquisition times of less than one minute. DPSS lasers are also versatile excitation sources for vibrational Raman spectroscopy, which is another common exercise that has been limited by lack of proper instrumentation in the teaching laboratory. This talk shows how to construct a simple accessory for commercial fluorimeters to record vibrational Raman spectra and depolarization ratios for CCl4_{4} and C2_{2}Cl4_{4} as part of a lab exercise featuring molecular symmetry

    Effects of patch size and number within a simple model of patchy colloids

    Get PDF
    We report on a computer simulation and integral equation study of a simple model of patchy spheres, each of whose surfaces is decorated with two opposite attractive caps, as a function of the fraction χ\chi of covered attractive surface. The simple model explored --- the two-patch Kern-Frenkel model --- interpolates between a square-well and a hard-sphere potential on changing the coverage χ\chi. We show that integral equation theory provides quantitative predictions in the entire explored region of temperatures and densities from the square-well limit χ=1.0\chi = 1.0 down to χ0.6\chi \approx 0.6. For smaller χ\chi, good numerical convergence of the equations is achieved only at temperatures larger than the gas-liquid critical point, where however integral equation theory provides a complete description of the angular dependence. These results are contrasted with those for the one-patch case. We investigate the remaining region of coverage via numerical simulation and show how the gas-liquid critical point moves to smaller densities and temperatures on decreasing χ\chi. Below χ0.3\chi \approx 0.3, crystallization prevents the possibility of observing the evolution of the line of critical points, providing the angular analog of the disappearance of the liquid as an equilibrium phase on decreasing the range for spherical potentials. Finally, we show that the stable ordered phase evolves on decreasing χ\chi from a three-dimensional crystal of interconnected planes to a two-dimensional independent-planes structure to a one-dimensional fluid of chains when the one-bond-per-patch limit is eventually reached.Comment: 26 pages, 11 figures, J. Chem. Phys. in pres

    Novel Characteristics of Valveless Pumping

    Get PDF
    This study investigates the occurrence of valveless pumping in a fluidfilled system consisting of two open tanks connected by an elastic tube. We show that directional flow can be achieved by introducing a periodic pinching applied at an asymmetrical location along the tube, and that the flow direction depends on the pumping frequency. We propose a relation between wave propagation velocity, tube length, and resonance frequencies associated with shifts in the pumping direction using numerical simulations. The eigenfrequencies of the system are estimated from the linearized system, and we show that these eigenfrequencies constitute the resonance frequencies and the horizontal slope frequencies of the system; 'horizontal slope frequency' being a new concept. A simple model is suggested, explaining the effect of the gravity driven part of the oscillation observed in response to the tank and tube diameter changes. Results are partly compared with experimental findings.Art. no. 22450

    Chemical-Equilibrium Analysis with Adjoint Derivatives for Propulsion Cycle Analysis

    Full text link
    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143118/1/1.B36215.pd
    corecore