Vacancy-assisted domain-growth in asymmetric binary alloys: A Monte Carlo Study

A Monte Carlo simulation study of the vacancy-assisted domain growth in asymmetric binary alloys is presented. The system is modeled using a three-state ABV Hamiltonian which includes an asymmetry term. Our simulated system is a stoichiometric two-dimensional binary alloy with a single vacancy which evolves according to the vacancy-atom exchange mechanism. We obtain that, compared to the symmetric case, the ordering process slows down dramatically. Concerning the asymptotic behavior it is algebraic and characterized by the Allen-Cahn growth exponent x51/2. The late stages of the evolution are preceded by a transient regime strongly affected by both the temperature and the degree of asymmetry of the alloy. The results are discussed and compared to those obtained for the symmetric case.

Modeling premartensitic effects in Ni2MnGa: A mean-field and Monte Carlo simulation study

ic first-order transition line ending in a critical point. This critical point is responsible for the existence of large premartensitic fluctuations which manifest as broad peaks in the specific heat, not always associated with a true phase transition. The main conclusion is that premartensitic effects result from the interplay between the softness of the anomalous phonon driving the modulation and the magnetoelastic coupling. In particular, the premartensitic transition occurs when such coupling is strong enough to freeze the involved mode phonon. The implication of the results in relation to the available experimental data is discussed.

Comparison between molecular dynamics abd Monte Carlo simulations of an ordering process in a binary alloy

Ordering in a binary alloy is studied by means of a molecular-dynamics (MD) algorithm which allows to reach the domain growth regime. Results are compared with Monte Carlo simulations using a realistic vacancy-atom (MC-VA) mechanism. At low temperatures fast growth with a dynamical exponent x>1/2 is found for MD and MC-VA. The study of a nonequilibrium ordering process with the two methods shows the importance of the nonhomogeneity of the excitations in the system for determining its macroscopic kinetics.

Closure of the Monte Carlo dynamical equation in the spherical Sherrington-Kirkpatrick model

We study the analytical solution of the Monte Carlo dynamics in the spherical Sherrington-Kirkpatrick model using the technique of the generating function. Explicit solutions for one-time observables (like the energy) and two-time observables (like the correlation and response function) are obtained. We show that the crucial quantity which governs the dynamics is the acceptance rate. At zero temperature, an adiabatic approximation reveals that the relaxational behavior of the model corresponds to that of a single harmonic oscillator with an effective renormalized mass.

An efficient scheme for the evaluation of coding performance of high speed links incorporating joint error behaviour based on Monte Carlo Method

While channel coding is a standard method of improving a system’s energy efficiency in digital communications, its practice does not extend to high-speed links. Increasing demands in network speeds are placing a large burden on the energy efficiency of high-speed links and render the benefit of channel coding for these systems a timely subject. The low error rates of interest and the presence of residual intersymbol interference (ISI) caused by hardware constraints impede the analysis and simulation of coded high-speed links. Focusing on the residual ISI and combined noise as the dominant error mechanisms, this paper analyses error correlation through concepts of error region, channel signature, and correlation distance. This framework provides a deeper insight into joint error behaviours in high-speed links, extends the range of statistical simulation for coded high-speed links, and provides a case against the use of biased Monte Carlo methods in this setting

THz Plasma Waves in Field-Effect-Transistors: A Monte Carlo Study

Sensing with electromagnetic waves having frequencies in the Terahertz-range is a very attractive investigative method with applications in fundamental research and industrial settings. Up to now, a lot of sources and detectors are available. However, most of these systems are bulky and have to be used in controllable environments such as laboratories. In 1993 Dyakonov and Shur suggested that plasma waves developing in field-effect-transistors can be used to emit and detect THz-radiation. Later on, it was shown that these plasma waves lead to rectification and allows for building efficient detectors. In contrast to the prediction that these plasma waves lead to new promising solid-state sources, only a few weak sources are known up to now. This work studies THz plasma waves in semiconductor devices using the Monte Carlo method in order to resolve this issue. A fast Monte Carlo solver was developed implementing a nonparabolic bandstructure representation of the used semiconductors. By investigating simplified field-effect-transistors it was found that the plasma frequency follows under equilibrium conditions the analytical predictions. However, no current oscillations were found at room temperature or with a current flowing in the channel. For more complex structures, consisting of ungated and gated regions, it was found that the plasma frequency does not follow the value predicted by the dispersion relation of the gated nor the ungated device.

Noticiero monte hacho

Se presenta experiencia educativa que propone dar a conocer el peri??dico escolar como medio de acercamiento de la escuela a la comunidad. Se realiza en el CPR Monte Hacho en Cuesta de la Palma, Granada. Los objetivos son: potenciar e implicar a todos los miembros de la comunidad educativa; intentar que el peri??dico sea un cauce de informaci??n y conocimiento entre los diversos miembros de la comunidad educativa; desarrollar objetivos curriculares de educaci??n en valores; dar a conocer determinadas actividades que se han desarrollado tanto fuera como dentro del centro y que se consideren de inter??s; crear un canal de comunicaci??n entre el alumnado de las diferentes localidades, ya que aunque pertenecen al mismo centro s??lo coinciden en salidas y convivencias espor??dicas.

Itinerario did??ctico por el Monte Arab??

El cuaderno de campo est?? pensado para ser utilizado en el propio monte. Cada alumno debe disponer de un cuaderno. Las actividades propuestas son para desarrollar en el aula antes y despu??s de la salida. Aparecen tambi??n actividades para el itinerario. La duraci??n de la salida es de un d??a. Los contenidos son: historia geol??gica, geomorfolog??a, vegetaci??n, fauna, f??siles, rese??a hist??rica y situaci??n ecol??gica. Adem??s incluye un plano de ruta, un gui??n de campo, actividades y fichas de campo.

Protagonistas de rosa y azul : 100 libros para una educación no sexista.

Selección de cien títulos de libros cuyo objetivo es modificar la percepción sexista del mundo que impera en nuestra sociedad y facilitar y ayudar a la mujer para que recupere su propia historia y valore adecuadamente sus aportaciones a lo largo de la historia. Este libro ofrece a las madres y padres, educadoras y educadores un medio para utilizar la literatura infantil y juvenil como apoyo a una educación que facilite una visión más global y completa del mundo y de su historia. En su primera parte, se aportan ideas sobre el sexismo y sociedad y sexismo y literatura. La selección de libros está dividida por bloques de edad: 0-4 años, de 5 a 7, 8 a 10, 11 a 13 y de 14 en adelante.

Un monte protegido : el Valle.

Las ilustraciones son de Javier Alberdi

Descubre la Sierra de Pelayo y el Monte Atalaya : cultura e historia de la Región de Murcia.

Segundo premio en la segunda edición de premios a la elaboración de materiales de estudio sobre la Región de Murcia en la modalidad de primaria.

Alguazas, ochenta años de educación : 1927 Colegio Primo de Rivera, 2007 Colegio Monte Anaor.

Publicación conmemorativa del 80 aniversario del Colegio Monte Anaor en Alguazas (Murcia), donde se exponen conferencias, colaboraciones y actividades escolares que pretenden ofrecer una retrospectiva histórica de la enseñanza, el trabajo y los logros cosechados por las personas vinculadas al centro desde su apertura en 1927..