3,932 research outputs found

    A method of predicting flow rates required to achieve anti-icing performance with a porous leading edge ice protection system

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    An analytical method was developed for predicting minimum flow rates required to provide anti-ice protection with a porous leading edge fluid ice protection system. The predicted flow rates compare with an average error of less than 10 percent to six experimentally determined flow rates from tests in the NASA Icing Research Tunnel on a general aviation wing section

    Forecasting and Hedging Crop Input Prices

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    Replaced with edited version of paper 12/23/08.Farm Management,

    Art for the Home-Schooled Student: A Document Analysis of Art Curricula Commonly Used by Georgia Home-Schoolers

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    The purpose of this study was both to determine the most popular art curricula used by home-schooled students in Georgia and also to access whether or not these curricula align with State and National Standards for art education as well as current trends in the field. This research was approached from a document analysis standpoint and individual curriculum documents were examined and evaluated. Seven curricula/teaching resources were identified as the most popular in the state of Georgia and these were evaluated individually to identify themes, which were then compared to themes present in the National and State Standards for art education. While there was some overlap in themes from the curricula examined and the State and National Standards, it was determined that on the whole the curricula made no concerted effort to adhere to these standards

    Milking Machine Maintenance

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    Human/Farm Animal Relationships

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    There are various combinations of human beings and farm animals. This paper attempts to evaluate those few studies of humans handling farm animals within a prescribed environment. Personality traits of dairy farmers and livestock people as determined by the Eysenck Personality Inventory (Eysenck 1977) need further study (Seabrook 1974; Arave and Brown 1979). Seabrook\u27s sample size was small (20 herds) and these herds were criticized for having low yields while Arave and Brown\u27s questionnaire did not go far enough

    Resonant leptogenesis in a predictive SO(10) grand unified model

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    An SO(10) grand unified model considered previously by the authors featuring lopsided down quark and charged lepton mass matrices is successfully predictive and requires that the lightest two right-handed Majorana neutrinons be nearly degenerate in order to obtain the LMA solar neutrino solution. Here we use this model to test its predictions for baryogenesis through resonant-enhanced leptogenesis. With the conventional type I seesaw mechanism, the best predictions for baryogenesis appear to fall a factor of three short of the observed value. However, with a proposed type III seesaw mechanism leading to three pairs of massive pseudo-Dirac neutrinos, resonant leptogenesis is decoupled from the neutrino mass and mixing issues with successful baryogenesis easily obtained.Comment: 22 pages including 1 figure; published version with reference adde

    Explicit SO(10) Supersymmetric Grand Unified Model for the Higgs and Yukawa Sectors

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    A complete set of fermion and Higgs superfields is introduced with well-defined SO(10) properties and U(1) x Z_2 x Z_2 family charges from which the Higgs and Yukawa superpotentials are constructed. The structures derived for the four Dirac fermion and right-handed Majorana neutrino mass matrices coincide with those previously obtained from an effective operator approach. Ten mass matrix input parameters accurately yield the twenty masses and mixings of the quarks and leptons with the bimaximal atmospheric and solar neutrino vacuum solutions favored in this simplest version.Comment: Published version appearing in PRL in which small modifications to original submission and a paragraph concerning proton decay appea

    Evaluation of a pneumatic boot deicing system on a general aviation wing model

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    The aerodynamic characteristics of a typical modern general aviation airfoil were investigated with and without a pneumatic boot ice protection system. The ice protection effectiveness of the boot was studied. This includes the change in drag on the airfoil with the boot inflated and deflated, the change in drag due to primary and residual ice formation, drag change due to cumulative residual ice formation, and parameters affecting boot effectiveness. Boot performance was not affected by tunnel total temperature or velocity. Marginal effect in performance was associated with angle of attack. Significant effects on performance were caused by variations in droplet size, LWC, ice cap thickness inflation pressure, and surface treatment

    Icing tunnel tests of a glycol-exuding porous leading edge ice protection system on a general aviation airfoil

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    A glycol-exuding porous leading edge ice protection system was tested. Results show that the system is very effective in preventing ice accretion (anti-ice mode) or removing ice from an airfoil. Minimum glycol flow rates required for anti-icing are a function of velocity, liquid water content in the air, ambient temperature, and droplet size. Large ice caps were removed in only a few minutes using anti-ice flow rates. It was found that the shed time is a function of the type of ice, size of the ice cap, angle of attack, and glycol flow rate. Wake survey measurements show that there is no significant drag penalty for the installation or operation of the system tested
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