1,454 research outputs found

    In Vitro Analysis of Antioxidant Activities of Oxalis Corniculata Linn. Fractions in Various Solvents

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    As part of our search for natural antioxidants, this work presents an evaluation of antioxidant activities of methanolic extract of Oxalis corniculata and its sub-fractions in hexane, chloroform, ethyl acetate, n-butanol and water. The total phenolic contents in terms of μg of gallic acid equivalents per mg of dried mass were approximately 21.0, 28.2, 34.5, 162.0, 70.0, and 49.2 in methanolic, hexane, chloroform, ethyl acetate, n-butanolic and aqueous fractions respectively, while the flavonoid contents in these solvents were 362.4, 214.1, 317.1, 177.1, 98.8 and 53.5 respectively in terms of μg of rutin per mg of dried mass. In DPPH assay, the ethyl acetate fraction showed the highest free radical scavenging activity, 24.0% with 1 mg/mL concentration. The second strongest fraction was chloroform (21.5%). The EC50 and TEC50 values of the methanolic extract were 3.63 mg/mL and 23 min respectively. The FRAP values in terms of μg of ascorbic acid equivalents per mg of dried mass for these solvents were 288.0, 1705.3, 437.1, 72.0, 28.0, and 44.0 respectively while total antioxidant activity measured by phosphomolybdate assay in terms of μg of ascorbic acid equivalents per mg of dried mass were 50.0, 117.0, 78.6, 57.8, 3.4 and 8.3 respectively. All the samples showed remarkable ability to inhibit lipid peroxidation exhibiting much better and sustainable peroxidation inhibitory activity than the standard butylated hydroxyanisole

    Monopole Percolation in pure gauge compact QED

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    The role of monopoles in quenched compact QED has been studied by measuring the cluster susceptibility and the order parameter nmax/ntotn_{max}/n_{tot} previously introduced by Hands and Wensley in the study of the percolation transition observed in non-compact QED. A correlation between these parameters and the energy (action) at the phase transition has been observed. We conclude that the order parameter nmax/ntotn_{max}/n_{tot} is a sensitive probe for studying the phase transition of pure gauge compact QED.Comment: LaTeX file + 4 PS figures, 12 pag., Pre-UAB-FT-308 ILL-(TH)-94-1

    ABO and Rh Blood Group Distribution Among Kunbis (Maratha) population of Amravati District, Maharashtra

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    The present study reports the distribution of ABO and Rh blood groups among the Kunbis (Maratha) population of Amravati district. The phenotypic frequency of blood group B is observed highest (33.06) percent, O (31.04), A (27.02) and AB is lowest (08.33) percent. The phenotypic frequency of Rh negative is (04.26) percent. TheKunbis (Maratha) population shows close genetic relationship with the Gujratis

    An Experiment to Evaluate Skylab Earth Resources Sensors for Detection of the Gulf Stream

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    The author has identified the following significant results. An experiment to evaluate the Skylab earth resources package for observing ocean currents was performed in the Straits of Florida in January 1974. Data from the S190 photographic facility, S191 spectroradiometer and S192 multispectral scanner, were compared with surface observations. The anticyclonic edge of the Gulf Stream could be identified in the Skylab S190A and B photographs, but the cyclonic edge was obscured by clouds. The aircraft photographs were judged not useful for spectral analysis because vignetting caused the blue/green ratios to be dependent on the position in the photograph. The spectral measurement technique could not identify the anticyclonic front, but mass of Florida Bay water which was in the process of flowing into the Straits could be identified and classified. Monte Carlo simulations of the visible spectrum showed that the aerosol concentration could be estimated and a correction technique was devised

    The Phases and Triviality of Scalar Quantum Electrodynamics

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    The phase diagram and critical behavior of scalar quantum electrodynamics are investigated using lattice gauge theory techniques. The lattice action fixes the length of the scalar (``Higgs'') field and treats the gauge field as non-compact. The phase diagram is two dimensional. No fine tuning or extrapolations are needed to study the theory's critical behovior. Two lines of second order phase transitions are discovered and the scaling laws for each are studied by finite size scaling methods on lattices ranging from 646^4 through 24424^4. One line corresponds to monopole percolation and the other to a transition between a ``Higgs'' and a ``Coulomb'' phase, labelled by divergent specific heats. The lines of transitions cross in the interior of the phase diagram and appear to be unrelated. The monopole percolation transition has critical indices which are compatible with ordinary four dimensional percolation uneffected by interactions. Finite size scaling and histogram methods reveal that the specific heats on the ``Higgs-Coulomb'' transition line are well-fit by the hypothesis that scalar quantum electrodynamics is logarithmically trivial. The logarithms are measured in both finite size scaling of the specific heat peaks as a function of volume as well as in the coupling constant dependence of the specific heats measured on fixed but large lattices. The theory is seen to be qualitatively similar to λϕ4\lambda\phi^{4}. The standard CRAY random number generator RANF proved to be inadequateComment: 25pages,26figures;revtex;ILL-(TH)-94-#12; only hardcopy of figures availabl

    Chiral transition and monopole percolation in lattice scalar QED with quenched fermions

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    We study the interplay between topological observables and chiral and Higgs transitions in lattice scalar QED with quenched fermions. Emphasis is put on the chiral transition line and magnetic monopole percolation at strong gauge coupling. We confirm that at infinite gauge coupling the chiral transition is described by mean field exponents. We find a rich and complicated behaviour at the endpoint of the Higgs transition line which hampers a satisfactory analysis of the chiral transition. We study in detail an intermediate coupling, where the data are consistent both with a trivial chiral transition clearly separated from monopole percolation and with a chiral transition coincident with monopole percolation, and characterized by the same critical exponent ν0.65\nu \simeq 0.65. We discuss the relevance (or lack thereof) of these quenched results to our understanding of the \chupiv\ model. We comment on the interplay of magnetic monopoles and fermion dynamics in more general contexts.Comment: 29 pages, 13 figures included, LaTeX2e (elsart

    Monopole Percolation in the Compact Abelian Higgs Model

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    We have studied the monopole-percolation phenomenon in the four dimensional Abelian theory that contains compact U(1) gauge fields coupled to unitary norm Higgs fields. We have determined the location of the percolation transition line in the plane (βg,βH)(\beta_g, \beta_H). This line overlaps the confined-Coulomb and the confined-Higgs phase transition lines, originated by a monopole-condensation mechanism, but continues away from the end-point where this phase transition line stops. In addition, we have determined the critical exponents of the monopole percolation transition away from the phase transition lines. We have performed the finite size scaling in terms of the monopole density instead of the coupling, because the density seems to be the natural parameter when dealing with percolation phenomena.Comment: 13 pages. REVTeX. 16 figs. included using eps

    Conjugate Refractive-Reflective Homogeniser in a 500x Cassegrain Concentrator: Design and Limits

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    This is the author accepted manuscript. The final version is available from IET via the DOI in this recordThere is another ORE record for this publication: http://hdl.handle.net/10871/19792In this study, we present the conjugate refractive reflective homogeniser (CRRH) to be used in a 500× Cassegrain photovoltaic concentrator. The CRRH is a dielectric crossed v-trough lined with a reflective film whilst maintaining an air gap between them. This air gap between the two surfaces helps in trapping the scattered light from the refractive geometry and ensures both total internal reflection and standard reflection of the escaped rays. A 10-42% drop in optical efficiency has been shown to occur due to varying the surface roughness of the homogeniser in these ray trace simulations for the Cassegrain setup. The CRRH increased the overall optical efficiency by a maximum of 7.75% in comparison with that of a standard refractive homogeniser simulated within the same concentrator system. The acceptance angle and flux distribution of these homogenisers was also investigated. The simple shape of the CRRH ensures easy manufacturing and produces a relatively uniform irradiance distribution on the receiver. The theoretical benefit of the CRRH is also validated via practical measurements. Further research is required but a 6.7% power increase was measured under a 1000 W/m2 solar simulator at normal incidence for the experimental test.Department of Science and Technology (DST), IndiaEngineering and Physical Sciences Research Council (EPSRC

    On the Logarithmic Triviality of Scalar Quantum Electrodynamics

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    Using finite size scaling and histogram methods we obtain numerical results from lattice simulations indicating the logarithmic triviality of scalar quantum electrodynamics, even when the bare gauge coupling is chosen large. Simulations of the non-compact formulation of the lattice abelian Higgs model with fixed length scalar fields on L4L^{4} lattices with LL ranging from 66 through 2020 indicate a line of second order critical points. Fluctuation-induced first order transitions are ruled out. Runs of over ten million sweeps for each LL produce specific heat peaks which grow logarithmically with LL and whose critical couplings shift with LL picking out a correlation length exponent of 0.50(5)0.50(5) consistent with mean field theory. This behavior is qualitatively similar to that found in pure λϕ4\lambda\phi^{4}.Comment: 9 page

    String tension in gonihedric 3D Ising models

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    For the 3D gonihedric Ising models defined by Savvidy and Wegner the bare string tension is zero and the energy of a spin interface depends only on the number of bends and self-intersections, in antithesis to the standard nearest-neighbour 3D Ising action. When the parameter kappa weighting the self-intersections is small the model has a first order transition and when it is larger the transition is continuous. In this paper we investigate the scaling of the renormalized string tension, which is entirely generated by fluctuations, using Monte Carlo simulations This allows us to obtain an estimate for the critical exponents alpha and nu using both finite-size-scaling and data collapse for the scaling function.Comment: Latex + postscript figures. 8 pages text plus 7 figures, spurious extra figure now removed
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