Finite Size Analysis of the U(1) Phase Transition using the World-sheet Formulation

We present a high statistics analysis of the pure gauge compact U(1) lattice theory using the the world-sheet or Lagrangian loop representation. We have applied a simulation method that deals directly with (gauge invariant) integer variables on plaquettes. As a result we get a significant amelioration of the simulation that allows to work with large lattices avoiding the metaestability problems that appear using the standard Wilson formulation.Comment: 14 pages, 4 figures. REVTEX and eps

The Lagrangian Loop Representation of Lattice U(1) Gauge Theory

It is showed how the Hamiltonian lattice $loop$ $representation$ can be cast straightforwardly in the Lagrangian formalism. The procedure is general and here we present the simplest case: pure compact QED. This connection has been shaded by the non canonical character of the algebra of the fundamental loop operators. The loops represent tubes of electric flux and can be considered the dual objects to the Nielsen-Olesen strings supported by the Higgs broken phase. The lattice loop classical action corresponding to the Villain form is proportional to the quadratic area of the loop world sheets and thus it is similar to the Nambu string action. This loop action is used in a Monte Carlo simulation and its appealing features are discussed.Comment: 13 pp, UAB-FT-341/9

Monopole Percolation in pure gauge compact QED

The role of monopoles in quenched compact QED has been studied by measuring the cluster susceptibility and the order parameter $n_{max}/n_{tot}$ 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 $n_{max}/n_{tot}$ 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

CERAMIC CORES FOR TURBINE BLADES : A TOOLING PERSPECTIVE

Blade/vane components used in aerospace turbines are of twisted aerofoil shape, made by the process of investment casting, using Ni based super-alloy materials. These castings operate at turbine inlet temperatures (TET) close to the melting point of the alloy, in order to maximize thermal efficiency and thrust of the engine. The castings are made hollow, with intricate features such as turbulator, pin-fin, etc built-in to maximize the effect of heat transfer during forced cooling through internal passages. The hollow geometry in the castings is produced during the investment casting process by using a suitable ceramic core made from Silica or Alumina based mixes. These ceramic cores are high pressure injected by forcing the ceramic mix into dedicated molds or dies. Development of such dies is an involved process by itself, addressing issues right from ceramic mix behavior to manufacturability of the injection mould. The present paper attempts to highlight issues related to tooling development for ceramic cores used in investment cast turbine blade/vane components

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

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 the Compact Abelian Higgs Model

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 $(\beta_g, \beta_H)$. 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

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

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

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

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

Cold atoms in non-Abelian gauge potentials: From the Hofstadter "moth" to lattice gauge theory

We demonstrate how to create artificial external non-Abelian gauge potentials acting on cold atoms in optical lattices. The method employs $n$ internal states of atoms and laser assisted state sensitive tunneling. Thus, dynamics are communicated by unitary $n\times n$-matrices. By experimental control of the tunneling parameters, the system can be made truly non-Abelian. We show that single particle dynamics in the case of intense U(2) vector potentials lead to a generalized Hofstadter butterfly spectrum which shows a complex ``moth''-like structure. We discuss the possibility to employ non-Abelian interferometry (Aharonov-Bohm effect) and address methods to realize matter dynamics in specific classes of lattice gauge fields.Comment: 5 pages, 3 figure

The Phases and Triviality of Scalar Quantum Electrodynamics

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 $6^4$ through $24^4$. 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 $\lambda\phi^{4}$. The standard CRAY random number generator RANF proved to be inadequateComment: 25pages,26figures;revtex;ILL-(TH)-94-#12; only hardcopy of figures availabl