Phase transition from hadronic matter to quark matter

We study the phase transition from nuclear matter to quark matter within the SU(3) quark mean field model and NJL model. The SU(3) quark mean field model is used to give the equation of state for nuclear matter, while the equation of state for color superconducting quark matter is calculated within the NJL model. It is found that at low temperature, the phase transition from nuclear to color superconducting quark matter will take place when the density is of order 2.5$\rho_0$ - 5$\rho_0$. At zero density, the quark phase will appear when the temperature is larger than about 148 MeV. The phase transition from nuclear matter to quark matter is always first order, whereas the transition between color superconducting quark matter and normal quark matter is second order.Comment: 18 pages, 11 figure

Fluid velocity measuring device

A fluid velocity measuring device is described which, when placed in a freestream fluid flow, causes vortices to be formed at a frequency proportional to the flow rate of the fluid. Sensors on the device generate electric signals with frequency proportional to the rate of vortex creation and with relative mean amplitudes indicative of fluid flow direction. Electric circuitry translates the electric signals into indications of fluid speed and direction

XSIL: Extensible Scientific Interchange Language

We motivate and define the XSIL language as a flexible, hierarchical, extensible transport language for scientific data objects. The entire object may be represented in the file, or there may be metadata in the XSIL file, with a powerful, fault-tolerant linking mechanism to external data. The language is based on XML, and is designed not only for parsing and processing by machines, but also for presentation to humans through web browsers and web-database technology. There is a natural mapping between the elements of the XSIL language and the object model into which they are translated by the parser. As well as common objects (Parameter, Array, Time, Table), we have extended XSIL to include the IGWDFrame, used by gravitational-wave observatories

La relación entre una nueva técnica de enseñanza de lenguas y las creencias tradicionales del alumnado

This paper explores the relationship between individuals’ expectations of language learning and their readiness to accept a particular language teaching paradigm. The participants are students in an upper-intermediate speaking class at a southern Hungarian university. The study reviews the typical kinds of language learning experience in the Hungarian educational context, which in turn form learners’ expectations, and discusses the implications that learners expectations may have for their own language learning and – should they become teachers themselves – for their own language teaching. The paper describes the three research perspectives that inform it: the task-based language teaching (TBLT) paradigm; classroom-based research; and learner beliefs. The two phases of the research had 56 participants engaged in two speaking tasks and, of these, 28 involved in one-on-one, semi-structured interviews. The respondents’ answers are discussed in terms of their experience of learning form and their teachers’ classroom management as well as their impressions of the speaking tasks they had just performed in the classroom. The paper then discusses the possibilities for methodological change in a context marked by traditional teaching and learning techniques.Este artículo explora la relación entre las expectativas de los alumnos al aprender idiomas y su predisposición para aceptar un cierto paradigma de enseñanza de la lengua. Los participantes son alumnos de una clase de conversación de nivel intermedio alto en una universidad del sur de Hungría. El estudio revisa los tipos de experiencias de aprendizaje de idiomas típicas del contexto educativo húngaro, que, a su vez afecta a las expectativas del alumnado, y analiza las consecuencias que las expectativas de los alumnos pudieran tener en su propio aprendizaje de lenguas y —en el caso de que lleguen a ser profesores— en como abordarían la enseñanza de idiomas. Se describen las tres perspectivas de investigación que conforman el artículo: el paradigma de enseñanza de lenguas por tareas, la investigación en el aula y las creencias del alumnado. Las dos fases de la investigación tuvieron cincuenta y seis participantes implicados en dos actividades de conversación, y de estos, veintiocho realizaron entrevistas individuales semiestructuradas. Las respuestas obtenidas se analizan teniendo en cuenta tanto su experiencia de aprendizaje como la gestión del la clase realizada por sus profesores así como también sus impresiones sobre las actividades de conversación que se habían llevado a cabo. Finalmente el artículo plantea distintas posibilidades para el cambio metodológico en un contexto marcado por una enseñanza y unas técnicas de aprendizaje tradicionales

Scale-free networks in complex systems

In the past few years, several studies have explored the topology of interactions in different complex systems. Areas of investigation span from biology to engineering, physics and the social sciences. Although having different microscopic dynamics, the results demonstrate that most systems under consideration tend to self-organize into structures that share common features. In particular, the networks of interaction are characterized by a power law distribution, $P(k)\sim k^{-\alpha}$, in the number of connections per node, $k$, over several orders of magnitude. Networks that fulfill this propriety of scale-invariance are referred to as ``scale-free''. In the present work we explore the implication of scale-free topologies in the antiferromagnetic (AF) Ising model and in a stochastic model of opinion formation. In the first case we show that the implicit disorder and frustration lead to a spin-glass phase transition not observed for the AF Ising model on standard lattices. We further illustrate that the opinion formation model produces a coherent, turbulent-like dynamics for a certain range of parameters. The influence, of random or targeted exclusion of nodes is studied.Comment: 9 pages, 4 figures. Proceeding to "SPIE International Symposium Microelectronics, MEMS, and Nanotechnology", 11-15 December 2005, Brisbane, Australi

In-medium electron-nucleon scattering

In-medium nucleon electromagnetic form factors are calculated in the quark meson coupling model. The form factors are typically found to be suppressed as the density increases. For example, at normal nuclear density and $Q^2 \sim 0.3 { GeV}^2$, the nucleon electric form factors are reduced by approximately 8% while the magnetic form factors are reduced by only 1 - 2%. These variations are consistent with current experimental limits but should be tested by more precise experiments in the near future.Comment: 14 pages, latex, 3 figure

ECONOMIC THRESHOLDS: AN APPLICATION TO FLORICULTURE

This paper introduces conjunctive optimal pest management and production decision rules applied to the floriculture industry. A grower is faced with optimally controlling multiple pests and applying cultural controls to maximize the expected net present value of benefits within a discrete time framework, subject to biological and marketing constraints.Crop Production/Industries,

OPTIMAL PEST CONTROL IN FLORICULTURE PRODUCTION OF ORNAMENTAL CROPS

We develop a conceptual bioeconomic model of floriculture production, wherein optimal decision rules depend on an intertemporal economic objective to maximize profits subject to economic and biological processes. The necessary conditions highlight intertemporal tradeoffs between aesthetic benefits and expected future net benefits of insect stocks, which have important policy implications.Research Methods/ Statistical Methods,