42,796 research outputs found

    Comparison of the Effects of Coconut Oil and Soyabean Oil on TSH Level and Weight Gain in Rabbits

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    The present study was conducted on 12 albino rabbits of either sex and weighing between 1-1.5kg to see the influence of coconut oil and soyabean oil on serum TSH levels and weight gain for a period of 12 weeks.  The rabbits were divided into 2 groups of six each.  Rabbits in group 1 were fed on coconut oil and in group 2 were fed on soyabean oil in addition to their standard diet.  At the end of 12 weeks we found that rabbits fed on soyabean oil had significant increase in TSH levels (p= 0.003) and gained more weight (p=0.000) when compared to rabbits fed on coconut oil

    Quantum-Chromodynamic Potential Model for Light-Heavy Quarkonia and the Heavy Quark Effective Theory

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    We have investigated the spectra of light-heavy quarkonia with the use of a quantum-chromodynamic potential model which is similar to that used earlier for the heavy quarkonia. An essential feature of our treatment is the inclusion of the one-loop radiative corrections to the quark-antiquark potential, which contribute significantly to the spin-splittings among the quarkonium energy levels. Unlike ccˉc\bar{c} and bbˉb\bar{b}, the potential for a light-heavy system has a complicated dependence on the light and heavy quark masses mm and MM, and it contains a spin-orbit mixing term. We have obtained excellent results for the observed energy levels of D0D^0, DsD_s, B0B^0, and BsB_s, and we are able to provide predicted results for many unobserved energy levels. Our potential parameters for different quarkonia satisfy the constraints of quantum chromodynamics. We have also used our investigation to test the accuracy of the heavy quark effective theory. We find that the heavy quark expansion yields generally good results for the B0B^0 and BsB_s energy levels provided that M1M^{-1} and M1lnMM^{-1}\ln M corrections are taken into account in the quark-antiquark interactions. It does not, however, provide equally good results for the energy levels of D0D^0 and DsD_s, which indicates that the effective theory can be applied more accurately to the bb quark than the cc quark.Comment: 17 pages of LaTeX. To appear in Physical Review D. Complete PostScript file is available via WWW at http://gluon.physics.wayne.edu/wsuhep/jim/heavy.p

    Bc spectroscopy in a quantum-chromodynamic potential model

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    We have investigated BcB_c spectroscopy with the use of a quantum-chromodynamic potential model which was recently used by us for the light-heavy quarkonia. We give our predictions for the energy levels and the EE1 transition widths. We also find, rather surprisingly, that although BcB_c is not a light-heavy system, the heavy quark effective theory with the inclusion of the mb1m_b^{-1} and mb1lnmbm_b^{-1}\ln m_b corrections is as successful for BcB_c as it is for BB and BsB_s.Comment: 10 page ReVTeX pape

    Conservation equations and physical models for hypersonic air flows in thermal and chemical nonequilibrium

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    The conservation equations for simulating hypersonic flows in thermal and chemical nonequilibrium and details of the associated physical models are presented. These details include the curve fits used for defining thermodynamic properties of the 11 species air model, curve fits for collision cross sections, expressions for transport properties, the chemical kinetics models, and the vibrational and electronic energy relaxation models. The expressions are formulated in the context of either a two or three temperature model. Greater emphasis is placed on the two temperature model in which it is assumed that the translational and rotational energy models are in equilibrium at the translational temperature, T, and the vibrational, electronic, and electron translational energy modes are in equilibrium at the vibrational temperature, T sub v. The eigenvalues and eigenvectors associated with the Jacobian of the flux vector are also presented in order to accommodate the upwind based numerical solutions of the complete equation set

    Surface Impedance Determination via Numerical Resolution of the Inverse Helmholtz Problem

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    Assigning boundary conditions, such as acoustic impedance, to the frequency domain thermoviscous wave equations (TWE), derived from the linearized Navier-Stokes equations (LNSE) poses a Helmholtz problem, solution to which yields a discrete set of complex eigenfunctions and eigenvalue pairs. The proposed method -- the inverse Helmholtz solver (iHS) -- reverses such procedure by returning the value of acoustic impedance at one or more unknown impedance boundaries (IBs) of a given domain, via spatial integration of the TWE for a given real-valued frequency with assigned conditions on other boundaries. The iHS procedure is applied to a second-order spatial discretization of the TWEs on an unstructured staggered grid arrangement. Only the momentum equation is extended to the center of each IB face where pressure and velocity components are co-located and treated as unknowns. The iHS is finally closed via assignment of the surface gradient of pressure phase over the IBs, corresponding to assigning the shape of the acoustic waveform at the IB. The iHS procedure can be carried out independently for different frequencies, making it embarrassingly parallel, and able to return the complete broadband complex impedance distribution at the IBs in any desired frequency range to arbitrary numerical precision. The iHS approach is first validated against Rott's theory for viscous rectangular and circular ducts. The impedance of a toy porous cavity with a complex geometry is then reconstructed and validated with companion fully compressible unstructured Navier-Stokes simulations resolving the cavity geometry. Verification against one-dimensional impedance test tube calculations based on time-domain impedance boundary conditions (TDIBC) is also carried out. Finally, results from a preliminary analysis of a thermoacoustically unstable cavity are presented.Comment: As submitted to AIAA Aviation 201

    A robust pseudo-inverse spectral filter applied to the Earth Radiation Budget Experiment (ERBE) scanning channels

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    Computer simulations of a least squares estimator operating on the ERBE scanning channels are discussed. The estimator is designed to minimize the errors produced by nonideal spectral response to spectrally varying and uncertain radiant input. The three ERBE scanning channels cover a shortwave band a longwave band and a ""total'' band from which the pseudo inverse spectral filter estimates the radiance components in the shortwave band and a longwave band. The radiance estimator draws on instantaneous field of view (IFOV) scene type information supplied by another algorithm of the ERBE software, and on a priori probabilistic models of the responses of the scanning channels to the IFOV scene types for given Sun scene spacecraft geometry. It is found that the pseudoinverse spectral filter is stable, tolerant of errors in scene identification and in channel response modeling, and, in the absence of such errors, yields minimum variance and essentially unbiased radiance estimates

    Gamma-Gamma Directional Correlations in Pr144

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