The gas–liquid phase-transition singularities in the framework of the liquid-state integral equation formalism

6 pages, 4 figures.-- PACS: 64.70.Fx; 65.20.+w; 02.30.Rz; 62.10.+sThe singularities of various liquid-state integral equations derived from the Ornstein–Zernike relation and its temperature derivatives, have been investigated in the liquid–vapor transition region. As a general feature, it has been found that the existence of a nonsolution curve on the vapor side of the phase diagram, on which both the direct and the total correlation functions become complex—with a finite isothermal compressibility—also corresponds to the locus of points where the constant-volume heat capacity diverges, in consonance with a divergence of the temperature derivative of the correlation functions. In contrast, on the liquid side of the phase diagram one finds that a true spinodal (a curve of diverging isothermal compressibilities) is reproduced by the Percus–Yevick and Martynov–Sarkisov integral equations, but now this curve corresponds to states with finite heat capacity. On the other hand, the hypernetted chain approximation exhibits a nonsolution curve with finite compressibilities and heat capacities in which, as temperature is lowered, the former tends to diverge.E.L. acknowledges financial support of the Dirección General de Investigación Científica y Técnica under Grant No. FIS2004-02954-C03-01. This work has been carried out under the auspices of the exchange agreement between the Consejo Superior de Investigaciones Científicas and the Russian Academy of Sciencies, which supported the exchange visits of E.L. and G.S. in the past two years.Peer reviewe

Analysis of Control Measures for Vector-borne Diseases Using a Multistage Vector Model with Multi-Host Sub-populations

We propose and analyze an epidemiological model for vector borne diseases that integrates a multi-stage vector population and several host sub-populations which may be characterized by a variety of compartmental model types: subpopulations all include Susceptible and Infected compartments, but may or may not include Exposed and/or Recovered compartments. The model was originally designed to evaluate the effectiveness of various prophylactic measures in malaria-endemic areas, but can be applied as well to other vector-borne diseases. This model is expressed as a system of several differential equations, where the number of equations depends on the particular assumptions of the model. We compute the basic reproduction number $\mathcal R_0$, and show that if $\mathcal R_0\leqslant 1$, the disease free equilibrium (DFE) is globally asymptotically stable (GAS) on the nonnegative orthant. If $\mathcal R_0>1$, the system admits a unique endemic equilibrium (EE) that is GAS. We analyze the sensitivity of $R_0$ and the EE to different system parameters, and based on this analysis we discuss the relative effectiveness of different control measures.Comment: 42 pages, 3 figures. arXiv admin note: substantial text overlap with arXiv:1808.0757

Soudan 2 data acquisition and trigger electronics

The 1.1 kton Soudan 2 calorimetric drift-chamber detector is read out by 16K anode wires and 32K cathode strips. Preamps from each wire or strip are bussed together in groups of 8 to reduce the number of ADC channels. The resulting 6144 channels of ionization signal are flash-digitized every 200 ns and stored in RAM. The raw data hit patterns are continually compared with programmable trigger multiplicity and adjacency conditions. The data acquisition process is managed in a system of 24 parallel crates each containing an Intel 80C86 microprocessor, which supervises a pipe-lined data compactor, and allows transfer of the compacted data via CAMAC to the host computer. The 80C86's also manage the local trigger conditions and can perform some parallel processing of the data. Due to the scale of the system and multiplicity of identical channels, semi-custom gate array chips are used for much of the logic, utilizing 2.5 micron CMOS technology

The Kentucky Noisy Monte Carlo Algorithm for Wilson Dynamical Fermions

We develop an implementation for a recently proposed Noisy Monte Carlo approach to the simulation of lattice QCD with dynamical fermions by incorporating the full fermion determinant directly. Our algorithm uses a quenched gauge field update with a shifted gauge coupling to minimize fluctuations in the trace log of the Wilson Dirac matrix. The details of tuning the gauge coupling shift as well as results for the distribution of noisy estimators in our implementation are given. We present data for some basic observables from the noisy method, as well as acceptance rate information and discuss potential autocorrelation and sign violation effects. Both the results and the efficiency of the algorithm are compared against those of Hybrid Monte Carlo. PACS Numbers: 12.38.Gc, 11.15.Ha, 02.70.Uu Keywords: Noisy Monte Carlo, Lattice QCD, Determinant, Finite Density, QCDSPComment: 30 pages, 6 figure

Mixing of scalar glueballs and flavour-singlet scalar mesons

We discuss in detail the extraction of hadronic mixing strengths from lattice studies. We apply this to the mixing of a scalar glueball and a scalar meson in the quenched approximation. We also measure correlations appropriate for flavour-singlet scalar mesons using dynamical quark configurations from UKQCD. This enables us to compare the results from the quenched study of the mixing with the direct determination of the mixed spectrum. Improved methods of evaluating the disconnected quark diagrams are also presented.Comment: 23 pages, 5 postscript figure

The nucleon's strange electromagnetic and scalar matrix elements

Quenched lattice QCD simulations and quenched chiral perturbation theory are used together for this study of strangeness in the nucleon. Dependences of the matrix elements on strange quark mass, valence quark mass and momentum transfer are discussed in both the lattice and chiral frameworks. The combined results of this study are in good agreement with existing experimental data and predictions are made for upcoming experiments. Possible future refinements of the theoretical method are suggested.Comment: 24 pages, 9 figure

An estimate of the flavour singlet contributions to the hyperfine splitting in charmonium

We explore the splitting between flavour singlet and non-singlet mesons in charmonium. This has implications for the hyperfine splitting in charmonium

A Study of Cosmic Ray Composition in the Knee Region using Multiple Muon Events in the Soudan 2 Detector

Deep underground muon events recorded by the Soudan 2 detector, located at a depth of 2100 meters of water equivalent, have been used to infer the nuclear composition of cosmic rays in the "knee" region of the cosmic ray energy spectrum. The observed muon multiplicity distribution favors a composition model with a substantial proton content in the energy region 800,000 - 13,000,000 GeV/nucleus.Comment: 38 pages including 11 figures, Latex, submitted to Physical Review

Контент социальных медиа как условие эффективных коммуникаций малого бизнеса с потребителем (на примере компании "Полли-Вилли")

Актуальность проблем связана с динамикой роста популярности социальных медиа среди предпринимателей разного масштаба в России. В связи с этим необходимо сформировать методологию для наиболее эффективного применения инструментов, находящихся в арсенале социальных медиа. Объект – контент социальных медиа, формируемый для продвижения в социальных сетях. Предмет – подходы к технологиям создания контента для эффективной коммуникации предприятия малого бизнеса с потребителями. Проблема – отсутствие прописанных комплексных технологий, приемов и методов продвижения бизнеса в социальных медиа (Российский сегмент). Цель – разработка подходов к созданию эффективного контента для предприятий малого бизнеса.Objective: to develop the approaches of creating effective content for small businesses. Problem: the lack of prescribed complex technologies, techniques and methods of business promotion in social media (Russian Segment). Object: social media content generated for promotion in social networks. Subject: approaches to content creation technologies for effective communication between small businesses with consumers