Improved numerical methods for turbulent viscous recirculating flows

The hybrid-upwind finite difference schemes employed in generally available combustor codes possess excessive numerical diffusion errors which preclude accurate quantative calculations. The present study has as its primary objective the identification and assessment of an improved solution algorithm as well as discretization schemes applicable to analysis of turbulent viscous recirculating flows. The assessment is carried out primarily in two dimensional/axisymetric geometries with a view to identifying an appropriate technique to be incorporated in a three-dimensional code

Neutralino Dark Matter in the Left-Right Supersymmetric Model

We study the neutralino sector of the left-right supersymmetric model. In addition to the possibilities available in the minimal supersymmetric model, the neutralino states can be superpartners of the U(1)_{B-L} gauge boson, the neutral SU(2)_R neutral gauge boson, or of the Higgs triplets. We analyze neutralino masses and determine the parameter regions for which the lightest neutralino can be one of the new pure states. We then calculate the relic density of the dark matter for each of these states and impose the constraints coming from the rho parameter, the anomalous magnetic moment of the muon, b -> s gamma, as well as general supersymmetric mass bounds. The lightest neutralino can be the bino, or the right-wino, or the neutral triplet higgsino, all of which have different couplings to the standard model particles from the usual neutralinos. A light bino satisfies all the experimental constraints and would be the preferred dark matter candidate for light supersymmetric scalar masses, while the right-wino would be favored by intermediate supersymmetric mass scales. The neutral triplet Higgs fermion satisfies the experimental bounds only in a small region of the parameter space, for intermediate to heavy supersymmetric scalar masses.Comment: 31 pages, 8 figures, one table and references added, to be published in Phys. Rev.

Efecto de los daños causados por el insecto escudo verde (Palomena prasina L.) en las características cualitativas de la avellana

This study was conducted in 2018 to determine the effects of green shield bug damage (GD) on the chemical properties of the hazelnut cultivar “Tombul”. The proximate composition, protein, total lipid (TL), carbohydrate, total ash ratio (TA), vitamin E (VE), total phenolics, energy values (EV), color value, fatty acid composition, total fatty acids, lipid oxidation, and nutritional quality index properties of the kernel were detected in relation to the "bug damage". The level of TL, TA, VE, EV, monounsaturated fatty acids (MUFA), and unsaturated/saturated fatty acids (UFA/SFA) were found to be lower in GD kernels than in good kernels (GK). Although the GD kernels had higher iodine, free fatty acidity, and peroxide levels, they showed lower oleic/linoleic acid levels, and rancimat values. In addition, the GD kernels contained lower PUFA/SFA and hypocholesterolemic/hypercholesterolemic ratios but higher atherogenicity and thrombogenicity index values.Este estudio se realizó en 2018 para determinar el efecto del daño del insecto escudo verde (DV) en las propiedades químicas del cultivar de avellana "Tombul". La composición proximal, proteína, lípidos totales (LT), carbohidratos, relación total de cenizas (CT), vitamina E (VE), fenólicos totales, valores de energía (E), color, composición de ácidos grasos, ácidos grasos totales, oxidación de lípidos e índice de calidad nutricional se determinaron en relación con los daños causados por el insecto. Se encontró que el nivel de LT, CT, VE, E, ácidos grasos monoinsaturados (MUFA) y ácidos grasos insaturados/saturados (UFA/SFA) fue menor en los granos de DV que en los granos buenos (GB). Aunque los granos de DV tienen niveles más altos de yodo, acidez, grasa libre y peróxidos, tienen niveles más bajos de la relación ácido oleico/linoleico y de los valores de rancimat. Además, los granos de DV tienen una relación más baja PUFA/SFA y de hipocolesterolémica/hipercolesterolémica, pero tienen valores de índice de aterogenicidad y trombogenicidad más altos

Leachate treatment technique utilizing fly ash as a low cost sorbent

This study was carried out to design a system for the inexpensive treatment of ash pond effluent or leachate. Twelve different coals were burned in three different types of coal fired boilers to determine the influence of coal composition, ash fusion temperatures, boiler additives, combustion conditions and co-firing of natural gas or oil with the coal, on the composition of the fly ash and bottom ash as well as the leaching and sorbate characteristics of the fly ash produced. The trace elemental analysis consisting of Ti, Cd, Sn, Ni, Pb, Mo, Cu, Cr. Zn, Mn, Ba, and V in the twelve coals and their respective fly and bottom ashes. In addition, the leaching characteristics of the fly ashes with respect to pH, Cd, B, Sn, Ni, Pb, Mo, Cu, Cr, Zn, Mn and Fe have been defined. The results indicate that in the combustion of low ash fusion coals, the Sn, Ni, Mo, Cu, Cr and Mn tend to concentrate in the bottom ash, whereas the Ti, Zn and Ba tend to concentrate in the fly ash. For the high fusion coal, Sn, Cd, Pb, Mo, Cu, Cr, Ba and V in the parent coal concentrate in the bottom ash and Ti, Ni, Zn and Mn in the fly ash. An increase in boiler temperatures were observed to favor lower concentrations of the above trace elements in fly ash particles produced from low ash fusion coals. Also, smaller fly ash particles were found to contain higher concentrations of the above trace elements when compared to that present in larger fly ash particles produced from the same coal. The addition of the additive LPA-40 (which contains sulfur compounds to alter the sensitivity of the fly ash) to the combustion gases appears partially responsible for the amount of sulfur found on the surface of the fly ash particles. Leaching of Cd, B, Sn, Ni, Pb, Mo, Cu, Cr, Zn, Mu and Fe from the fly ash was found to be directly proportional to (1) the amount of these trace elements present in the fly ash, (2) decrease in pH, (3) decreases in boiler temperatures and (4) increases in ash fusion temperatures. Fly ash particles which in general leached the least amount of the above elements exhibited the best sorbate characteristics

FOOD SAFETY IN THE MEAT INDUSTRY: A REGULATORY QUAGMIRE

Food Consumption/Nutrition/Food Safety, Livestock Production/Industries,

FIRMS, INCENTIVES, AND THE SUPPLY OF FOOD SAFETY: A FORMAL MODEL OF GOVERNMENT ENFORCEMENT

Recent instances of significant food safety breeches in both meat and biotechnology challenge traditional safety efforts. A formal model utilizing agency theory is used to explore the power relationships between the regulator and the firm. Fundamental issues effecting firms' supply of safety are demonstrated and alternative corrective mechanisms are discussed.Food Consumption/Nutrition/Food Safety,

CP-Odd Phase Effects in a Left-Right Symmetric Chargino Sector

The left-right supersymmetric model contains a right-handed gaugino, as well as several higgsinos, in addition to the minimal supersymmetric model. Thus several CP-noninvariant phases appear in this sector. We analyze their impact on chargino masses and find that only two combinations are physically relevant. We then study the production of charginos in e+e- annihilation and chargino decays into a sneutrino and a lepton, and investigate the effects of CP-phases. We also study the CP-odd asymmetry in the production and subsequent decay at the linear collider with longitudinally polarized beams and find a large enhancement when the decay channel to the right sneutrino is available. The effects of the phases in the left-right supersymmetric chargino sector are different from the minimal supersymmetric standard model, and signals from this sector would be able to distinguish between different gauge symmetries.Comment: 24 pages, 11 figures, minor clarifications in the model part, to be published in Phys. Rev.

Quantal description of nucleon exchange in stochastic mean-field approach

Nucleon exchange mechanism is investigated in central collisions of symmetric heavy-ions in the basis of the stochastic mean-field approach. Quantal diffusion coefficients for nucleon exchange are calculated by including non-Markovian effects and shell structure. Variances of fragment mass distributions are calculated in central collisions of ${}^{40}$Ca + ${}^{40}$Ca, ${}^{48}$Ca + ${}^{48}$Ca and ${}^{56}$Ni + ${}^{56}$Ni systems