32,597 research outputs found
SU(2) potentials in quantum gravity
We present investigations of the potential between static charges from a
simulation of quantum gravity coupled to an SU(2) gauge field on and simplicial lattices. In the well-defined phase of the
gravity sector where geometrical expectation values are stable, we study the
correlations of Polyakov loops and extract the corresponding potentials between
a source and sink separated by a distance . In the confined phase, the
potential has a linear form while in the deconfined phase, a screened Coulombic
behavior is found. Our results indicate that quantum gravitational effects do
not destroy confinement due to non-abelian gauge fields.Comment: 3 pages, contribution to Lattice 94 conference, uuencoded compressed
postscript fil
Estuary and barrier island study
The author has identified the following significant results. Scan line distortion is apparent in ERTS-1 imagery, imparting a serrated-edge appearance to shorelines. This feature however does not hinder observation and interpretation of broad features such as shoaling areas and sediment plumes. Shoaling in the backshore areas and inlets is easily discernible in spectral bands 4 and 5. Contrast between land and water is especially striking in spectral band 7, allowing easy identification of tidal flat areas
Direct application of UNIFAC activity coefficient computer programs to the calculation of solvent activities and .chi.-parameters for polymer solutions
Application of UNIFAC computer calculations to polymer solutions does not seem to make sense because of the value of the solvent activity: close to 1.000 over a considerable range of concentrations (up to 90% of polymer). A simple procedure is proposed to calculate solvent activity coefficients, and thus X-parameters, such that the easily available UNIFAC computer programs may be applied directly, without any modification
Microparticle impact sensor measures energy directly
Construction of a capacitor sensor consisting of a dielectric layer between two conductive surface layers and connected across a potential source through a sensing resistor permits measurement of energy of impinging particles without degradation of sensitivity. A measurable response is produced without penetration of the dielectric layer
Multicanonical Recursions
The problem of calculating multicanonical parameters recursively is
discussed. I describe in detail a computational implementation which has worked
reasonably well in practice.Comment: 23 pages, latex, 4 postscript figures included (uuencoded
Z-compressed .tar file created by uufiles), figure file corrected
Phase diagram of Regge quantum gravity coupled to SU(2) gauge theory
We analyze Regge quantum gravity coupled to SU(2) gauge theory on , and simplicial lattices. It turns out that
the window of the well-defined phase of the gravity sector where geometrical
expectation values are stable extends to negative gravitational couplings as
well as to gauge couplings across the deconfinement phase transition. We study
the string tension from Polyakov loops, compare with the -function of
pure gauge theory and conclude that a physical limit through scaling is
possible.Comment: RevTeX, 14 pages, 5 figures (2 eps, 3 tex), 2 table
Biased Metropolis-Heat-Bath Algorithm for Fundamental-Adjoint SU(2) Lattice Gauge Theory
For SU(2) lattice gauge theory with the fundamental-adjoint action an
efficient heat-bath algorithm is not known so that one had to rely on
Metropolis simulations supplemented by overrelaxation. Implementing a novel
biased Metropolis-heat-bath algorithm for this model, we find improvement
factors in the range 1.45 to 2.06 over conventionally optimized Metropolis
simulations. If one optimizes further with respect to additional overrelaxation
sweeps, the improvement factors are found in the range 1.3 to 1.8.Comment: 4 pages, 2 figures; minor changes and one reference added; accepted
for publication in PR
The Failure of Local and Federal Prosecutors to Curb Police Brutality
Although police departments across the country have attempted to ameliorate the hostility between police officers and the cumminity, through careful screening of applicants, minority recruitment, and community policing, police brutality remains a problem within our urban cities. This Essay will first argue that police brutality is largely ignored. Second, it will examine the obstacles facing local and federal prosecutors in obtaining convictions. Then it will compare the advantages and disadvantages of delegating primary responsibility for these cases to the state versus the federal level. Finally, it will argue that, although there are obstacles and advantages for both local and federal prosecutors, ultimately justice is best seved when police brutality is primarily pursued by local prosecutors
Transport in nanofluidic systems: a review of theory and applications
In this paper transport through nanochannels is assessed, both of liquids and of dissolved molecules or ions. First, we review principles of transport at the nanoscale, which will involve the identification of important length scales where transitions in behavior occur. We also present several important consequences that a high surface-to-volume ratio has for transport. We review liquid slip, chemical equilibria between solution and wall molecules, molecular adsorption to the channel walls and wall surface roughness. We also identify recent developments and trends in the field of nanofluidics, mention key differences with microfluidic transport and review applications. Novel opportunities are emphasized, made possible by the unique behavior of liquids at the nanoscale
- …