92,894 research outputs found
On automorphic points in polarized deformation rings
For a fixed mod automorphic Galois representation, -adic automorphic Galois representations lifting it determine points in universal deformation space. In the case of modular forms and under some technical conditions, B\"{o}ckle showed that every component of deformation space contains a smooth modular point, which then implies their Zariski density when coupled with the infinite fern of Gouv\^{e}a-Mazur. We generalize B\"{o}ckle's result to the context of polarized Galois representations for CM fields, and to two dimensional Galois representations for totally real fields. More specifically, under assumptions necessary to apply a small theorem and an assumption on the local mod representation, we prove that every irreducible component of the universal polarized deformation space contains an automorphic point. When combined with work of Chenevier, this implies new results on the Zariski density of automorphic points in polarized deformation space in dimension three
What Do We Mean When We Talk about the 'Political Class'?
This is the peer reviewed version of the following article: Allen, Peter, and Paul Cairney. "What Do We Mean When We Talk about the âPolitical Classâ?." Political Studies Review (2015), which has been published in final form at http://dx.doi.org/10.1111/1478-9302.12092. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving
Configurational Temperature in Membrane Simulations Using Dissipative Particle Dynamics
The use of excessively long timesteps in dissipative particle dynamics
simulations may produce simulation artifacts due to the generation of
configurations which are not representative of the desired canonical ensemble.
The configurational temperature, amongst other quantities, may be used to
assess the extent of the deviation from equilibrium. This paper presents
results for simulations of models of water, and lipid bilayer membranes, to
illustrate the nature of the problems.Comment: 13 pages, 7 figures, RevTex
Different Melting Behavior in Pentane and Heptane Monolayers on Graphite; Molecular Dynamics Simulations
Molecular dynamics simulations are utilized to study the melting transition
in pentane (C5H12) and heptane (C7H16), physisorbed onto the basal plane of
graphite at near-monolayer coverages. Through use of the newest, optimized
version of the anisotropic united-atom model (AUA4) to simulate both systems at
two separate coverages, this study provides evidence that the melting
transition for pentane and heptane monolayers are significantly different.
Specifically, this study proposes a very rapid transition from the solid
crystalline rectangular-centered (RC) phase to a fluid phase in pentane
monolayers, whereas heptane monolayers exhibit a slower transition that
involves a more gradual loss of RC order in the solid-fluid phase transition.
Through a study of the melting behavior, encompassing variations where the
formation of gauche defects in the alkyl chains are eliminated, this study
proposes that this gradual melting behavior for heptane monolayers is a result
of less orientational mobility of the heptane molecules in the solid RC phase,
as compared to the pentane molecules. This idea is supported through a study of
a nonane monolayer, which gives the gradual melting signature that heptane
monolayers also seem to indicate. The results of this work are compared to
previous experiment over pentane and heptane monolayers, and are found to be in
good agreement
The directional contact distance of two ellipsoids: Coarse-grained potentials for anisotropic interactions
Copyright @ 2005 American Institute of Physics.We obtain the distance of closest approach of the surfaces of two arbitrary ellipsoids valid at any orientation and separation measured along their intercenter vector. This directional distance is derived from the elliptic contact function. The geometric meaning behind this approach is clarified. An elliptic pair potential for modeling arbitrary mixtures of elliptic particles, whether hard or soft, is proposed based on this distance. Comparisons with Gay-Berne potentials are discussed. Analytic expressions for the forces and torques acting on the elliptic particles are given.This research has been supported by GlaxoSmith-Klin
Novel crystal phase in suspensions of hard ellipsoids
We present a computer simulation study on the crystalline phases of hard
ellipsoids of revolution. For aspect ratios greater than or equal to 3 the
previously suggested stretched-fcc phase [D. Frenkel and B. M. Mulder, Mol.
Phys. 55, 1171 (1985)] is replaced by a novel crystalline phase. Its unit cell
contains two ellipsoids with unequal orientations. The lattice is simple
monoclinic. The angle of inclination of the lattice, beta, is a very soft
degree of freedom, while the two right angles are stiff. For one particular
value of beta, the close-packed version of this crystal is a specimen of the
family of superdense packings recently reported [Donev et al., Phys. Rev. Lett.
92, 255506 (2004)]. These results are relevant for studies of nucleation and
glassy dynamics of colloidal suspensions of ellipsoids.Comment: 4 pages, 4 figure
Conducting a thermal conductivity survey
A physically transparent approximate theory of phonon decay rates is presented starting from a pair potential model of the interatomic forces in an insulator or semiconductor. The theory applies in the classical regime and relates the 3-phonon decay rate to the third derivative of the pair potential. Phonon dispersion relations do not need to be calculated, as sum rules relate all the needed quantities directly to the pair potential. The Brillouin zone averaged phonon lifetime turns out to involve a dimensionless measure of the anharmonicity multiplied by an effective density of states for 3-phonon decay. Results are given for rare gas and alkali halide crystals. For rare gases, the results are in good agreement with more elaborate perturbation calculations. Comparison to experimental data on phonon linewidths and thermal conductivity are made
Self-acting lift-pad geometry for circumferential seals: A noncontacting concept
A segmented circumferential seal with lift pads for hydrodynamic action was analyzed over ranges of speed and sealed pressure. Performance predictions, which predicted noncontact operation for speeds as high as 600 revolutions per second at sealed pressures to 86 N/sq cm, are discussed. Performance tests were performed on the seals and compared with the performance predictions
Self-acting geometry for noncontact seals
Performance ot two self acting seal designs for a liquid oxygen (LOX) turbopump was predicted over ranges of pressure differential and speed. Predictions were compared with test results. Performance of a radial face seal for LOX was predicted up to 448 N/cu cm and 147 m/sec. Performance of a segmented circumferential seal for helium was predicted up to 69 N/cu cm and 189 m/sec. Results confirmed predictions of noncontact operation. Qualitative agreement between test and analysis was found. The LOX face seal evidently operated with mostly liquid in the self acting geometry and mostly gas across the dam
Circular 53
The regeneration of interior Alaskaâs commercial forest lands is mandated by
Alaskaâs Forest Resources and Practices Act (1979). This act requires that regeneration
be established adequate to ensure a sustained yield on forested lands from
which the timber has been harvested. Post-logging regeneration efforts now are
aimed at exposing mineral soil for the natural seeding of white spruce. Soil exposure
has been accomplished by blade scarifying with a crawler tractor which
provides large seed sites or by using a Bracke-type patch scarifier which produces
small seed sites of about 2 ft2. Arlidge (1967) reports that larger seedbeds have
greater regeneration success than smaller ones. Some researchers have found that
the regeneration of the larger plots may be too successful, requiring weeding and
precommercial thinning to bring stocking to satisfactory levels (Zasada and Grigal
1978). The Alaska Division of Forestry (DOF) has not been satisfied with the
cost or effectiveness of either of these site-preparation practices.Introduction -- Methods -- Results and Discussion: Contractor #2, Contractor #3 -- Comparisons -- Conclusions -- Resources Cite
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