Monte Carlo simulation of recrystallization

A Monte Carlo computer simulation technique, in which a continuum system is modeled employing a discrete lattice, has been applied to the problem of recrystallization. Primary recrystallization is modeled under conditions where the degree of stored energy is varied and nucleation occurs homogeneously (without regard for position in the microstructure). The nucleation rate is chosen as site saturated. Temporal evolution of the simulated microstructures is analyzed to provide the time dependence of the recrystallized volume fraction and grain sizes. The recrystallized volume fraction shows sigmoidal variations with time. The data are approximately fit by the Johnson-Mehl-Avrami equation with the expected exponents, however significant deviations are observed for both small and large recrystallized volume fractions. Under constant rate nucleation conditions, the propensity for irregular grain shapes is decreased and the density of two sided grains increases

Recursive linear estimation for discrete time systems in the presence of different multiplicative observation noises

This paper describes a design for a least mean square error estimator in discrete time systems where the components of the state vector, in measurement equation, are corrupted by different multiplicative noises in addition to observation noise. We show how known results can be considered a particular case of the algorithm stated in this paperState estimation, multiplicative noise, uncertain observations

Autogestión obrera: las colectivizaciones libertarias (España 1936-1938)

Con este trabajo se pretende dar a conocer, puesto que creo que es una parte poco conocida de nuestra historia reciente, la obra realizada en la España republicana, en un contexto de Guerra Civil, mayoritariamente por los anarquistas de la C.N.T. y en menor medida, pero nada despreciable, por los socialistas de la U.G.T.: LAS COLECTIVIZACIONES. Aquí se habla de la salida o solución que encontraron las clases más pobres de la sociedad española, es decir el proletariado del campo y ciudad, para no seguir muriéndose de hambre Estos hombres admirables tomaron las riendas de su destino y consiguieron, por un periodo breve en el tiempo dadas las circunstancias, ser dueños de sus decisiones sin necesidad de patronos, autogestionándose y asentando las bases de una Sociedad más justa.Grado en Relaciones Laborales y Recursos Humano

Optimal system size for complex dynamics in random neural networks near criticality

In this Letter, we consider a model of dynamical agents coupled through a random connectivity matrix, as introduced in [Sompolinsky et. al, 1988] in the context of random neural networks. It is known that increasing the disorder parameter induces a phase transition leading to chaotic dynamics. We observe and investigate here a novel phenomenon in the subcritical regime : the probability of observing complex dynamics is maximal for an intermediate system size when the disorder is close enough to criticality. We give a more general explanation of this type of system size resonance in the framework of extreme values theory for eigenvalues of random matrices.Comment: 11 pages, 2 figure

La lectura del paisaje, propuesta de etnociencias para la educación ambiental comunitaria

Una asociación civil promotora del desarrollo sostenible en 22 comunidades del estado Guanajuato, México, enmarca las actividades de Educación Ambiental Comunitaria (EAC) realizadas por 90 estudiantes del nivel preparatorio en un bosque de Encinos. La Lectura del Paisaje propuesta, centra focos de observación del entorno y propone la configuración de disposiciones para la alfabetización científica: el silencio, la escucha, la mirada y la curiosidad. Acciones analizadas desde registros etnográficos y videos construyen narrativas vinculadas a disposiciones éticas: respeto, aceptación; su singularidad radica en vehicular los contenidos científicos estéticamente con raíces culturales y étnicas

Performance optimization in switched reluctance motor drives

In this paper, switched reluctance motors (SRM) are proposed as an alternative for electric power assisted steering (EPAS) applications. A prototype machine has been developed as very attractive design for a steering electric motor, both from a cost and size perspective. A fourphase 8/6 SRM drive is designed for a rack type EPAS which should provide a maximum force of 10 kN. Two-dimension finite element analysis is used to validate the design

Anisotropic thermal magnetoresistance for an active control of radiative heat transfer

We predict a huge anisotropic thermal magnetoresistance (ATMR) in the near-field radiative heat transfer between magneto-optical particles when the direction of an external magnetic field is changed with respect to the heat current direction. We illustrate this effect with the case of two InSb spherical particles where we find that the ATMR amplitude can reach values of up to 800% for a magnetic field of 5 T, which is many orders of magnitude larger than its spintronic analogue in electronic devices. This thermomagnetic effect could find broad applications in the fields of ultrafast thermal management as well as magnetic and thermal remote sensing.Comment: 6 pages, 4 figure

Folklore e institucionalización.

Sin resume

A Theoretical Framework for Lagrangian Descriptors

This paper provides a theoretical background for Lagrangian Descriptors (LDs). The goal of achieving rigourous proofs that justify the ability of LDs to detect invariant manifolds is simplified by introducing an alternative definition for LDs. The definition is stated for $n$-dimensional systems with general time dependence, however we rigorously prove that this method reveals the stable and unstable manifolds of hyperbolic points in four particular 2D cases: a hyperbolic saddle point for linear autonomous systems, a hyperbolic saddle point for nonlinear autonomous systems, a hyperbolic saddle point for linear nonautonomous systems and a hyperbolic saddle point for nonlinear nonautonomous systems. We also discuss further rigorous results which show the ability of LDs to highlight additional invariants sets, such as $n$-tori. These results are just a simple extension of the ergodic partition theory which we illustrate by applying this methodology to well-known examples, such as the planar field of the harmonic oscillator and the 3D ABC flow. Finally, we provide a thorough discussion on the requirement of the objectivity (frame-invariance) property for tools designed to reveal phase space structures and their implications for Lagrangian descriptors

Non-Markovian Quantum Dynamics and Classical Chaos

We study the influence of a chaotic environment in the evolution of an open quantum system. We show that there is an inverse relation between chaos and non-Markovianity. In particular, we remark on the deep relation of the short time non-Markovian behavior with the revivals of the average fidelity amplitude-a fundamental quantity used to measure sensitivity to perturbations and to identify quantum chaos. The long time behavior is established as a finite size effect which vanishes for large enough environments.Comment: Closest to the published versio