1,046 research outputs found
Generalized probabilities in statistical theories
In this review article we present different formal frameworks for the
description of generalized probabilities in statistical theories. We discuss
the particular cases of probabilities appearing in classical and quantum
mechanics, possible generalizations of the approaches of A. N. Kolmogorov and
R. T. Cox to non-commutative models, and the approach to generalized
probabilities based on convex sets
Presentación de un levantamiento geomorfológico como documento básico para trazar mapas de peligrosidad natural
[Resumen] El siguiente trabajo describe una leyenda geomorfologica aplicativa donde van a señalarse los procesos naturales. Cada uno de ellos tiene una manifestación temporal y espacial. Por ello va a darse mucha relevancia a las recurrencias específicas de cada proceso y, a la vez, una representación cartográfica de los fenómenos descritos. Las inestabilidades de ladera tendrán un seguimiento particular. A partir de un trabajo de síntesis, pueden superponerse todos los caracteres sobre el mapa geomorfologico con la finalidad de trazar mapas de peligrosidad natural..[Abstract] The next work shows an applied legend on geomorphology where is possible to carry out natural processes in order to study spatial and temporal features. At both processes is being affected to specific recurrence, spatial behaviour and thereby is subjected to mapping. After that, the local smalllandslides was based on a specific study. Along a synthesis approach it is possible to cover up the first geomorphological survey for depicting natural hazard maps
Perspectivas pedagógicas en geomorfología.
[Resumen] Los nuevos planes que se están poniendo en práctica en educación primaria y secundaria como consecuencia de la aplicación de la LOGSE, así como la reorganización de los estudios universitarios, contemplan algunos aspectos de geomorfología aplicada en varias asignaturas. El presente trabajo va a tratar cuestiones concernientes al área de conocimiento de Ciencias de la Tierra y del Espacio, concretamente se aborda la problemática que suponen las inundaciones. Para hacerlo accesible a los estudiantes se proponen juegos de simulación territorial que forman parte de un proyecto curricular que con carácter experimental venimos desarrollando en centros de enseñanza de La Rioja.[Abstract] At the present, the national education authorities of Spain are involved in the arrangements of the Education Act named LOGSE for aH knowledge levels as primary, secondary and thereby university departments outside of LOGSE are implementing some subjects on applied geomorphology. So as, at the next work a little features into the province of Earth and Environment Sciences and particulary flood problems also are treated. AH of material is available for accessing the environmental issues to students using territory role - play games. At last, the results are covered from an educational project developed in secondary schools of La Rioja region
Systematic perturbation calculation of integrals with applications to physics
In this paper we generalize and improve a method for calculating the period
of a classical oscillator and other integrals of physical interest, which was
recently developed by some of the authors. We derive analytical expressions
that prove to be more accurate than those commonly found in the literature, and
test the convergence of the series produced by the approach.Comment: 11 pages, 5 figure
Effect of long range spatial correlations on the lifetime statistics of an emitter in a two-dimensional disordered lattice
The effect of spatial correlations on the Purcell effect in a bidimensional
dispersion of resonant nanoparticles is analyzed. We perform extensive
calculations on the fluorescence decay rate of a point emitter embedded in a
system of nanoparticles statistically distributed according to a simple 2D
lattice-gas model near the critical point. For short-range correlations (high
temperature thermalization) the Purcell factors present a long-tailed statistic
which evolves towards a bimodal distribution when approaching the critical
point where the spatial correlation length diverges. Our results suggest
long-range correlations as a possible origin of the large fluctuations of
experimental decay rates in disordered metal films.Comment: 6 pages, 5 figure
The period of a classical oscillator
We develop a simple method to obtain approximate analytical expressions for
the period of a particle moving in a given potential. The method is inspired to
the Linear Delta Expansion (LDE) and it is applied to a large class of
potentials. Precise formulas for the period are obtained.Comment: 5 pages, 4 figure
Analysis of polymeric phenolics in red wines using different techniques combined with gel permeation chromatography fractionation
A multiple-step analytical method was developed to improve the analysis of polymeric phenolics in red wines. With a common initial step based on the fractionation of wine phenolics by gel permeation chromatography (GPC), different analytical techniques were used: high-performance liquid chromatography-diode array detection (HPLC-DAD), HPLC-mass spectrometry (MS), capillary zone electrophoresis (CZE) and spectrophotometry. This method proved to be valid for analyzing different families of phenolic compounds, such as monomeric phenolics and their derivatives, polymeric pigments and proanthocyanidins. The analytical characteristics of fractionation by GPC were studied and the method was fully validated, yielding satisfactory statistical results. GPC fractionation substantially improved the analysis of polymeric pigments by CZE, in terms of response, repeatability and reproducibility. It also represented an improvement in the traditional vanillin assay used for proanthocyanidin (PA) quantification. Astringent proanthocyanidins were also analyzed using a simple combined method that allowed these compounds, for which only general indexes were available, to be quantified. © 2005 Elsevier B.V. All rights reserved
Transition from Diffusive to Localized Regimes in Surface Corrugated Optical Waveguides
Exact calculations of the transmittance of surface corrugated optical
waveguides are presented. The elastic scattering of diffuse light or other
electromagnetic waves from a rough surface induces a diffusive transport along
the waveguide axis. As the length of the corrugated part of the waveguide
increases, a transition from the diffusive to the localized regime is observed.
This involves an analogy with electron conduction in nanowires, and hence, a
concept analogous to that of ``resistance'' can be introduced. We show an
oscillatory behavior of both the elastic mean free path and the localization
length versus the wavelength.Comment: 3 pages, REVTEX, 3 PS figure
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