Non-diffusive transport in plasma turbulence: a fractional diffusion approach

Numerical evidence of non-diffusive transport in three-dimensional, resistive pressure-gradient-driven plasma turbulence is presented. It is shown that the probability density function (pdf) of test particles' radial displacements is strongly non-Gaussian and exhibits algebraic decaying tails. To model these results we propose a macroscopic transport model for the pdf based on the use of fractional derivatives in space and time, that incorporate in a unified way space-time non-locality (non-Fickian transport), non-Gaussianity, and non-diffusive scaling. The fractional diffusion model reproduces the shape, and space-time scaling of the non-Gaussian pdf of turbulent transport calculations. The model also reproduces the observed super-diffusive scaling

Chaotic dynamics and superdiffusion in a Hamiltonian system with many degrees of freedom

We discuss recent results obtained for the Hamiltonian Mean Field model. The model describes a system of N fully-coupled particles in one dimension and shows a second-order phase transition from a clustered phase to a homogeneous one when the energy is increased. Strong chaos is found in correspondence to the critical point on top of a weak chaotic regime which characterizes the motion at low energies. For a small region around the critical point, we find anomalous (enhanced) diffusion and L\'evy walks in a transient temporal regime before the system relaxes to equilibrium.Comment: 7 pages, Latex, 6 figures included, Contributed paper to the Int. Conf. on "Statistical Mechanics and Strongly Correlated System", 2nd Giovanni Paladin Memorial, Rome 27-29 September 1999, submitted to Physica

On the Quantum Mechanics for One Photon

This paper revisits the quantum mechanics for one photon from the modern viewpoint and by the geometrical method. Especially, besides the ordinary (rectangular) momentum representation, we provide an explicit derivation for the other two important representations, called the cylindrically symmetrical representation and the spherically symmetrical representation, respectively. These other two representations are relevant to some current photon experiments in quantum optics. In addition, the latter is useful for us to extract the information on the quantized black holes. The framework and approach presented here are also applicable to other particles with arbitrary mass and spin, such as the particle with spin 1/2.Comment: 15 pages, typos corrected, references added, corrections and improvements made owing to the anonymous referee's responsible and helpful remarks, accepted for publication in Journal of Mathematical Physics:

Uso de energía solar para la cocción de pan sustituido parcialmente por harina de quinoa (Chenopodium Quinoa Wild.)

Objetivos: 1) Estudiar las condiciones de funcionamiento de dos hornos solares: tipo caja y tipo tambor; 2) Evaluar la cocción de panes elaborados con harina de quinoa y 3) Estudiar la respuesta del consumidor en su aceptabilidad. Los panes con 0, 10, 15 y 20% de sustitución se hornearon y se midió radiación (W/m2 ), temperatura ambiente (°C) y temperatura interna del pan durante la cocción. Se realizaron pruebas de aceptabilidad con 112 consumidores. La hora local en que se alcanza la máxima temperatura interna del pan (tT°max), la velocidad de aumento de ésta (Va), el tiempo de duración de la cocción (Tdur) y el área bajo la curva (ABC) fueron las variables más afectadas por las condiciones de radiación y temperatura ambiente. El tipo de horno y el porcentaje de sustitución no fueron significativos en la aceptabilidad. Se observó una tendencia a valorar más el pan con 10% de quinoa.Aims: 1) to study the behavior of the working conditions of box type and drum solar cookers; 2) evaluate the cooking process of breads with quinoa flour and 3) study the consumer’s acceptability response. Four formulations were established with 0, 10, 15 and 20% of wheat flour substitution, and they were cooked into the cookers. Cookers working conditions–radiation (W/m2 ) and environment temperature (°C)- and internal temperature of the breads were measured during cooking process. Sensory acceptability tests were performed with 112 consumers. The cooking variables mostly affected by daily conditions of radiation and environment temperature were: local time at which the maximum temperature (tT°max) of breads was reached, rate of increase (Va), duration time (tdur) and area under the curve (ABC). The cooker type and % of quinoa were not significant on the sensory acceptability; therefore it was observed a tendency to prefer the bread with 10% of quinoa.Fil: Passamai, Victor Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Salta. Instituto de Investigaciones en Energía no Convencional; Argentina. Universidad Nacional de Salta. Facultad de Cs.exactas. Departamento de Fisica; ArgentinaFil: Armada, M.. Universidad Nacional de Salta. Consejo de Investigacion; Argentina. Universidad Nacional de Salta. Facultad de Ingenieria; ArgentinaFil: del Castillo, V.. Universidad Nacional de Salta. Consejo de Investigacion; ArgentinaFil: Goldner, Maria Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Salta. Instituto de Investigación para la Industria Química (i); Argentina. Universidad Nacional de Salta; Argentin

A nonstationary generalization of the Kerr congruence

Making use of the Kerr theorem for shear-free null congruences and of Newman's representation for a virtual charge ``moving'' in complex space-time, we obtain an axisymmetric time-dependent generalization of the Kerr congruence, with a singular ring uniformly contracting to a point and expanding then to infinity. Electromagnetic and complex eikonal field distributions are naturally associated with the obtained congruence, with electric charge being necesssarily unit (``elementary''). We conjecture that the corresponding solution to the Einstein-Maxwell equations could describe the process of continious transition of the naked ringlike singularitiy into a rotating black hole and vice versa, under a particular current radius of the singular ring.Comment: 6 pages, twocolum

Anomalous transport in Charney-Hasegawa-Mima flows

Transport properties of particles evolving in a system governed by the Charney-Hasegawa-Mima equation are investigated. Transport is found to be anomalous with a non linear evolution of the second moments with time. The origin of this anomaly is traced back to the presence of chaotic jets within the flow. All characteristic transport exponents have a similar value around $\mu=1.75$, which is also the one found for simple point vortex flows in the literature, indicating some kind of universality. Moreover the law $\gamma=\mu+1$ linking the trapping time exponent within jets to the transport exponent is confirmed and an accumulation towards zero of the spectrum of finite time Lyapunov exponent is observed. The localization of a jet is performed, and its structure is analyzed. It is clearly shown that despite a regular coarse grained picture of the jet, motion within the jet appears as chaotic but chaos is bounded on successive small scales.Comment: revised versio

Physical activity, fitness and adiposity: immigrants versus spanish scholars (Actividad física, condición física y adiposidad: inmigrantes versus escolares españoles)

The objective was to analyse the associations of physical fitness and patterns of physical activity with adiposity in native and foreign. This study was performed with 612 school students (8-10 years). Anthropometric measurements, physical fitness and activity patterns were studied. The results showed that students who practiced more physical activity had lower body mass index and higher levels of fitness. Immigrants had lower adiposity and higher participation in sport activities than native students. No differences between native and foreing students in levels were found, except for immigrant girls, who showed greater lower body strengh than the natives ones. In conclusion, immigrants from this study appear to have a healthier fitness, physical activity and adiposity than natives. El objetivo fue analizar las asociaciones entre los niveles de condición física, patrones de actividad física y adiposidad del alumnado nativo e inmigrante. Se estudiaron 612 niños (8-10 años) de colegios públicos, valorándose mediante pruebas antropométricas, condición física y cuestionario de hábitos de actividad física. Se observó que el alumnado que realizaba mayor actividad física presentaba menor índice de masa corporal y mayor condición física. El alumnado inmigrante presentó menor adiposidad y mayor participación en actividades deportivas. No encontramos diferencias en condición física, salvo en chicas inmigrantes, con mayor fuerza del tren inferior. En conclusión, los inmigrantes del presente estudio parecen poseer un perfil más saludable de condición física, actividad física y adiposidad que los nativos

Physical activity, fitness and adiposity: immigrants versus spanish scholars

El objetivo fue analizar las asociaciones entre los niveles de condición física, patrones de actividad física y adiposidad del alumnado nativo e inmigrante. Se estudiaron 612 niños (8-10 años) de colegios públicos, valorándose mediante pruebas antropométricas, condición física y cuestionario de hábitos de actividad física. Se observó que el alumnado que realizaba mayor actividad física presentaba menor índice de masa corporal y mayor condición física. El alumnado inmigrante presentó menor adiposidad y mayor participación en actividades deportivas. No encontramos diferencias en condición física, salvo en chicas inmigrantes, con mayor fuerza del tren inferior. En conclusión, los inmigrantes del presente estudio parecen poseer un perfil más saludable de condición física, actividad física y adiposidad que los nativos.The objective was to analyse the associations of physical fitness and patterns of physical activity with adiposity in native and foreign. This study was performed with 612 school students (8-10 years). Anthropometric measurements, physical fitness and activity patterns were studied. The results showed that students who practiced more physical activity had lower body mass index and higher levels of fitness. Immigrants had lower adiposity and higher participation in sport activities than native students. No differences between native and foreing students in levels were found, except for immigrant girls, who showed greater lower body strengh than the natives ones. In conclusion, immigrants from this study appear to have a healthier fitness, physical activity and adiposity than natives.Este estudio ha sido financiando por la de la Dirección General de Participación e Innovación Educativa, por la que se aprueban proyectos de investigación e innovación educativa y de elaboración de materiales curriculares de de la Consejería de Educación de Andalucía. RESOLUCIÓN de 14 de julio de 2010 (PIV-038/10), y con una beca del Ministerio de Ciencia e Investigación (JCI-2010-07055)