Shear flow, viscous heating, and entropy balance from dynamical systems

A consistent description of a shear flow, the accompanied viscous heating, and the associated entropy balance is given in the framework of a deterministic dynamical system, where a multibaker dynamics drives two fields: the velocity and the temperature distributions. In an appropriate macroscopic limit their transport equations go over into the Navier-Stokes and the heat conduction equation of viscous flows. The inclusion of an artificial heat sink can stabilize steady states with constant temperatures. It mimics a thermostating algorithm used in non-equilibrium molecular-dynamics simulations.Comment: LaTeX 2e (epl.cls + sty-files for Europhys Lett included); 7 pages + 1 eps-figur

Melting of Hard Cubes

The melting transition of a system of hard cubes is studied numerically both in the case of freely rotating cubes and when there is a fixed orientation of the particles (parallel cubes). It is shown that freelly rotating cubes melt through a first-order transition, whereas parallel cubes have a continuous transition in which positional order is lost but bond-orientational order remains finite. This is interpreted in terms of a defect-mediated theory of meltingComment: 5 pages, 3 figures included. To appear in Phys. Rev.

Performance, Politics and Media: How the 2010 British General Election leadership debates generated ‘talk’ amongst the electorate.

During the British General Election 2010 a major innovation was introduced in part to improve engagement: a series of three live televised leadership debates took place where the leader of each of the three main parties, Labour, Liberal Democrat and Conservative, answered questions posed by members of the public and subsequently debated issues pertinent to the questions. In this study we consider these potentially ground breaking debates as the kind of event that was likely to generate discussion. We investigate various aspects of the ‘talk’ that emerged as a result of watching the debates. As an exploratory study concerned with situated accounts of the participants experiences we take an interpretive perspective. In this paper we outline the meta-narratives (of talk) associated with the viewing of the leadership debates that were identified, concluding our analysis by suggesting that putting a live debate on television and promoting and positioning it as a major innovation is likely to mean that is how the audience will make sense of it – as a media event

Simulational Study on Dimensionality-Dependence of Heat Conduction

Heat conduction phenomena are studied theoretically using computer simulation. The systems are crystal with nonlinear interaction, and fluid of hard-core particles. Quasi-one-dimensional system of the size of $L_x\times L_y\times L_z(L_z\gg L_x,L_y)$ is simulated. Heat baths are put in both end: one has higher temperature than the other. In the crystal case, the interaction potential $V$ has fourth-order non-linear term in addition to the harmonic term, and Nose-Hoover method is used for the heat baths. In the fluid case, stochastic boundary condition is charged, which works as the heat baths. Fourier-type heat conduction is reproduced both in crystal and fluid models in three-dimensional system, but it is not observed in lower dimensional system. Autocorrelation function of heat flux is also observed and long-time tails of the form of $\sim t^{-d/2}$, where $d$ denotes the dimensionality of the system, are confirmed.Comment: 4 pages including 3 figure

Heat-denatured human immunodeficiency virus type 1 protein 24 antigen: prognostic value in adults with early-stage disease

CD4(+) lymphocyte count and human immunodeficiency virus (HIV) type 1 RNA level are useful for determining when to initiate antiretroviral therapy but are not used widely in developing countries due to the high cost. Heat-denatured protein 24 (p24) antigen is an inexpensive assay that predicts disease progression among persons with advanced disease but has not been assessed among persons with early-stage disease. Plasma levels of heat-denatured p24 antigen were quantified in baseline study-visit specimens obtained from injection drug users enrolled in a longitudinal cohort study of HIV-1 infection. Of the 494 study participants (median initial CD4(+) lymphocyte count, 518 lymphocytes/mm(3)), 90 (18%) progressed to acquired immunodeficiency syndrome within 5 years. p24 antigen level correlated with both CD4(+) lymphocyte count (r=-0.34; P5 pg/mL predicted disease progression, comparable with that of cutoff CD4(+) lymphocyte count 30,000 copies/mL. Heat-denatured p24 antigen level predicted subsequent clinical disease progression in early-stage HIV-1 infection and correlated with both CD4(+) lymphocyte count and HIV-1 RNA leve

Brownian Motors driven by Particle Exchange

We extend the Langevin dynamics so that particles can be exchanged with a particle reservoir. We show that grand canonical ensembles are realized at equilibrium and derive the relations of thermodynamics for processes between equilibrium states. As an application of the proposed evolution rule, we devise a simple model of Brownian motors driven by particle exchange. KEYWORDS: Langevin Dynamics, Thermodynamics, Open SystemsComment: 5 pages, late

Finite thermal conductivity in 1d lattices

We discuss the thermal conductivity of a chain of coupled rotators, showing that it is the first example of a 1d nonlinear lattice exhibiting normal transport properties in the absence of an on-site potential. Numerical estimates obtained by simulating a chain in contact with two thermal baths at different temperatures are found to be consistent with those ones based on linear response theory. The dynamics of the Fourier modes provides direct evidence of energy diffusion. The finiteness of the conductivity is traced back to the occurrence of phase-jumps. Our conclusions are confirmed by the analysis of two variants of this model.Comment: 4 pages, 3 postscript figure

Summary of Proposed Updates to the National Health Security Preparedness Index for 2015-2016

This report describes proposed updates in methodology and measures for the 2015-16 release of the National Health Security Preparedness Inde