4,948 research outputs found

    COMPARING END-USE VALUES FOR NORTH DAKOTA HARD RED SPRING WHEAT VARIETIES

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    Markets for agricultural products may be inefficient when signals do not adequately reflect product characteristics important to market participants. Although preferences can be explicitly stated through price premiums or characteristic values can be determined via hedonic methods, the problem is compounded when product quality information is costly to obtain. Bundling of quality traits by variety can serve to signal product quality. A procedure is developed in this paper to derive the value of different varieties in meeting buyer demands. An application to the hard red spring market wheat both validates the ability of the procedure to distinguish among varieties, as well as provides empirical support to the existence of Akerlof's lemon market in the release of wheat varieties.Agricultural markets, product quality, distance functions, wheat, Crop Production/Industries, Marketing,

    An Investigation of Ionic Wind Propulsion

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    A corona discharge device generates an ionic wind and thrust, when a high voltage corona discharge is struck between sharply pointed electrodes and larger radius ground electrodes. The objective of this study was to examine whether this thrust could be scaled to values of interest for aircraft propulsion. An initial experiment showed that the thrust observed did equal the thrust of the ionic wind. Different types of high voltage electrodes were tried, including wires, knife-edges, and arrays of pins. A pin array was found to be optimum. Parametric experiments, and theory, showed that the thrust per unit power could be raised from early values of 5 N/kW to values approaching 50 N/kW, but only by lowering the thrust produced, and raising the voltage applied. In addition to using DC voltage, pulsed excitation, with and without a DC bias, was examined. The results were inconclusive as to whether this was advantageous. It was concluded that the use of a corona discharge for aircraft propulsion did not seem very practical

    AGRICULTURAL VALUE ADDED: PROSPECTS FOR NORTH DAKOTA

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    Introduction: This report provides an overview of the important factors affecting investments in agricultural value-added ventures. The introductory section outlines current research on factors important in the location of economic activity. Research applied to specific agricultural value-added ventures, such as food manufacturing and livestock feeding and finishing operations, are discussed. A listing of resources available to entrepreneurs considering value-added investments concludes the introductory section. Following the introductory section are short overviews of industries that already have, or may have, potential for increasing economic activity in the state. All are based on the important foundation of agriculture in the state's economy or upon the natural resource base giving the state a comparative advantage in investments in alternative energy or resource-based recreation.Agribusiness,

    Radiometer offsets and count conversion coefficients for the Earth Radiation Budget Experiment (ERBE) spacecraft for the years 1984, 1985, and 1986

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    A compendium is presented of the ground and inflight scanner and nonscanner offsets and count conversion (gain) coefficients used for the Earth Radiation Budget Experiment (ERBE) production processing of data from the ERBS, NOAA-9, and NOAA-10 satellites for the 1 Nov. 1984 to 31 Dec. 1986

    Biology and management of river herring and shad in Virginia : Annual report, Anadromous Fish Project 1974

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    This annual report covers the period October, .1973 through September, 1974. It is the seventh report generated by\u27 the project, with 3-year completion reports prepared in 1970 and 1973. The project· is continuing at VIMS and each year allows stronger conclusions to be made concerning trends in the basic population parameters studied. The 1970-1973 completion report was widely distributed in Virginia, libraries at fishery science institutes, and throughout the National Marine Fisheries Service. The completion report analyzed data from the entire history of the project. In many cases the entire summarized data core for a particular segment was presented, e.g. mortality rates and age composition of the run since 1966. Some jobs were presented in final. analysis form, because they were made inactive after 1973. The history of the foreign fleet activities was presented with an analysis of their effect on the anadromous alosids. \u2

    Hydrodynamic Stability Criterion for Colloidal Gelation under Gravity

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    Attractive colloids diffuse and aggregate to form gels, solid-like particle networks suspended in a fluid. Gravity is known to strongly impact the stability of gels once they are formed. However, its effect on the process of gel formation has seldom been studied. Here, we simulate the effect of gravity on gelation using both Brownian dynamics and a lattice-Boltzmann algorithm that accounts for hydrodynamic interactions. We work in a confined geometry to capture macroscopic, buoyancy-induced flows driven by the density mismatch between fluid and colloids. These flows give rise to a stability criterion for network formation, based on an effective accelerated sedimentation of nascent clusters at low volume fractions that disrupts gelation. Above a critical volume fraction, mechanical strength in the forming gel network dominates the dynamics: the interface between the colloid-rich and colloid-poor region moves downward at an ever decreasing rate. Finally, we analyze the asymptotic state, the colloidal gel-like sediment, which we find not to be appreciably impacted by the vigorous flows that can occur during the settling of the colloids. Our findings represent the first steps toward understanding how flow during formation affects the life span of colloidal gels.Comment: 14 pages, 15 figures, 3 movie
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