1,257 research outputs found
Simulation of quantum zero-point effects in water using a frequency-dependent thermostat
Molecules like water have vibrational modes with a zero-point energy well
above room temperature. As a consequence, classical molecular dynamics
simulations of their liquids largely underestimate the energy of modes with a
higher zero-point temperature, which translates into an underestimation of
covalent interatomic distances due to anharmonic effects. Zero-point effects
can be recovered using path integral molecular dynamics simulations, but these
are computationally expensive, making their combination with ab initio
molecular dynamics simulations a challenge. As an alternative to path integral
methods, from a computationally simple perspective, one would envision the
design of a thermostat capable of equilibrating and maintaining the different
vibrational modes at their corresponding zero-point temperatures. Recently,
Ceriotti et al. (Phys. Rev. Lett. 102 020601 (2009)) introduced a framework to
use a custom-tailored Langevin equation with correlated noise that can be used
to include quantum fluctuations in classical molecular dynamics simulations.
Here we show that it is possible to use the generalized Langevin equation with
suppressed noise in combination with Nose-Hoover thermostats to efficiently
impose a zero-point temperature on independent modes in liquid water. Using our
simple and inexpensive method, we achieve excellent agreement for all atomic
pair correlation functions compared to the path integral molecular dynamics
simulation.Comment: 27 pages, 12 figs, Published versio
Religious experiences of travellers visiting the Royal Monastery of Santa Maria de Guadalupe (Spain)
El Real Monasterio de Guadalupe ha sido uno de los destinos religiosos más importantes de España desde el siglo XIV, cuando se encontró la escultura de madera negra de la Virgen María (esculpida en el siglo I d. C.). Fue declarado Patrimonio de la Humanidad por la Organización de las Naciones Unidas para la Educación, la Ciencia y la Cultura (UNESCO) en 1993 y actualmente es un turismo atracción de interés internacional. Es visitado por más de 60,000 turistas anualmente, incluidos peregrinos y otras personas interesadas en el patrimonio cultural y natural de la zona. El objetivo de este estudio fue descifrar las formas en que los turistas experimentan la religiosidad con diferentes motivaciones, es decir, para comprender mejor cómo la religión está vinculada al turismo a través de nociones encarnadas de la piedad en diferentes modalidades de turismo. Se entrevistó a un total de 242 visitantes en el verano de 2017. Se les preguntó sobre las principales motivaciones para sus visitas, que se clasificaron en cinco grupos (razones religiosas, culturales, ambientales, sociales y educativas) y se utilizaron como variables latentes en un modelo de ecuación estructural de camino (SEM). El modelo mostró un fuerte poder predictivo (R2 = 87.5%) informando una influencia positiva significativa de las motivaciones religiosas, culturales y ambientales en el turismo religioso en esta región.The Royal Monastery of Guadalupe has been one of the most important religious destinations in Spain since the 14th century, when the black wooden sculpture of the Virgin Mary (sculpted in the 1st century AD) was found. It was declared a World Heritage Site by United Nations Educational, Scientific and Cultural organization (UNESCO) in 1993 and is presently a tourism attraction of international interest. It is visited by more than 60,000 tourists annually, including pilgrims and other people interested in the cultural and natural heritage of the area. The aim of this study was to decipher ways that religiousness is experienced by tourists with different motivations, i.e., to better understand how religion is linked to tourism through embodied notions of godliness in different modalities of tourism. A total of 242 visitors were interviewed in the summer of 2017. They were asked about the main motivations for their visits, which were classified into five groups (religious, cultural, environmental, social, and educational reasons) and used as latent variables in a path structural equation model (SEM). The model showed strong predictive power (R2 = 87.5%) reporting a significant positive influence of religious, cultural, and environmental motivations on religious tourism in this region.peerReviewe
Religious travellers' improved attitude towards nature
La peregrinación es una de las formas más antiguas de turismo. Hoy en día, se está convirtiendo en un fenómeno de masas que puede conducir a graves problemas de degradación ambiental en sitios valiosos. En este trabajo, hemos analizado mediante un modelo de ecuación estructural cómo la conciencia religiosa se inspira en la religiosidad / espiritualidad de cada peregrino. Podría predecir sus efectos en los turistas con respecto a una actitud mejorada (es decir, sensibilizada y más sostenible) hacia la naturaleza. El estudio se llevó a cabo en Guadalupe, España, que es un destino de peregrinación comúnmente conocido desde 1389. Se encuestó a un total de 203 visitantes utilizando un cuestionario compuesto por 16 preguntas, divididas en 4 dimensiones (actitudes enriquecidas hacia la naturaleza, conciencia religiosa, desarrollo sostenible y desarrollo humano ambiental), que se utilizaron como construcciones en el modelo. Los resultados mostraron cómo la conciencia religiosa influye positivamente en el desarrollo sostenible (β = 0.657, t = 11.306) y el desarrollo humano ambiental (β = 0.566, t = 8.255) explicando el 75.6% de las actitudes más sensibles de los viajeros religiosos hacia la naturaleza. Nuestros hallazgos sugieren que aún se necesita una investigación más profunda, sobre el papel desempeñado por la religiosidad como una semilla para fomentar la sostenibilidad.Pilgrimage is one of the most ancient forms of tourism. Nowadays, it is becoming a mass phenomenon that can lead to serious problems of environmental degradation in valuable sites. In this work, we have analysed by means of a structural equation model how religious consciousness is inspired in the religiosity/spirituality of each pilgrim. It could predict its effects on tourists regarding an improved (i.e., sensitised and more sustainable) attitude towards nature. The study was carried out in Guadalupe, Spain, which is a commonly known pilgrimage destination since 1389. A total of 203 visitors were surveyed using a questionnaire composed of 16 questions, divided into 4 dimensions (enriched attitudes toward nature, religious consciousness, sustainable development, and environmental human development), which were used as constructs in the model. The results showed how religious consciousness positively influences sustainable development (β = 0.657, t = 11.306) and environmental human development (β = 0.566, t = 8.255) explaining 75.6% of religious travellers’ more sensitive attitudes towards nature. Our findings suggest that a deeper research, on the role played by religiosity as a seed of fostering sustainability, is still needed.• Research Institute for Sustainable Territorial Development (INTERRA). Patrocinio
• Universidad de Extremadura. AyudapeerReviewe
Thermal 3D CFD Simulation with Active Transparent Façade in Buildings
In recent years active façades have acquired greater importance given their capacity to improve the energy efficiency of buildings. One such type is the so-called Active Transparent Façade (ATF). A 3D numerical model based on computational fluid dynamics (CFD) and the Finite Element Method (FEM) has been generated to simulate the thermal performance of buildings equipped with this type of façade. This model is introduced for general application and allows the design parameters to be adapted for this system. The case study of Le Corbusier’s proposal for the City of Refuge in
Paris, the clearest example of previous use of an ATF is examined. In addition, a proposal is presented for the energy improvement of Le Corbusier’s original solution. In order to do so, the conditions for the supply of air into the ATF cavity and in the mechanical ventilation system are assessed to guarantee comfort conditions
Thermal 3D CFD Simulation with Active Transparent Façade in Buildings
In recent years active façades have acquired greater importance given their capacity to improve the energy efficiency of buildings. One such type is the so-called Active Transparent Façade (ATF). A 3D numerical model based on computational fluid dynamics (CFD) and the Finite Element Method (FEM) has been generated to simulate the thermal performance of buildings equipped with this type of façade. This model is introduced for general application and allows the design parameters to be adapted for this system. The case study of Le Corbusier’s proposal for the City of Refuge in
Paris, the clearest example of previous use of an ATF is examined. In addition, a proposal is presented for the energy improvement of Le Corbusier’s original solution. In order to do so, the conditions for the supply of air into the ATF cavity and in the mechanical ventilation system are assessed to guarantee comfort conditions
Nonlocal electron heat relaxation in a plasma shock at arbitrary ionization number
A recently obtained nonlocal expression for the electron heat flux valid for arbitrary ionization numbers Z is used to study the structure of a plane shock wave in a fully ionized plasma.
Nonlocal effects are only important in the foot of the electronic preheating region, where the electron temperature gradient is the steepest. The results are quantified as a function of a characteristic Knudsen number of that region. This work also generalizes to arbitrary values of Z previous results on plasma shock wave structure
Self-consistent, nonlocal electron heat flux at arbitrary ion charge number
A single, nonlocal expression for the electron heat flux, which closely reproduces known results at high and low ion charge number 2, and “exact” results for the local limit at all 2, is derived by solving the kinetic equation in a narrow, tail-energy range. The solution involves asymptotic expansions of Bessel functions of large argument, and (Z-dependent)order above or below it, corresponding to the possible parabolic or hyperbolic character of the kinetic equation; velocity space diffusion in self-scattering is treated similarly to isotropic thermalization of tail energies in large Z analyses. The scale length H characterizing nonlocal effects varies with Z, suggesting an equal dependence of any ad hoc flux limiter. The model is valid for all H above the mean-free path for thermal electrons
Estimating DSGE Models using Multilevel Sequential Monte Carlo in Approximate Bayesian Computation
21-25Dynamic Stochastic General Equilibrium (DSGE) models allow for probabilistic estimations with the aim of formulating macroeconomic policies and monitoring them. In this study, we propose to apply the Sequential Monte Carlo Multilevel algorithm and Approximate Bayesian Computation (MLSMC-ABC) to increase the robustness of DSGE models built for small samples and with irregular data. Our results indicate that MLSMC-ABC improves the estimation of these models in two aspects. Firstly, the accuracy levels of the existing models are increased, and secondly, the cost of the resources used is reduced due to the need for shorter execution time
Isometrías en la resolución de problemas y obras de arte
En este trabajo se resuelven dos problemas planteados en las asignaturas Bases Matemáticas y Diseño y Desarrollo del Currículo de los estudios de Maestro en Educación Primaria de la Universidad de Granada, con el contenido matemático común de las isometrías en el plano. En un problema de rebotes en el billar, la identificación de simetrías axiales se convierte en una interesante estrategia de resolución. En el problema de construcción de mosaicos, las isometrías permiten visualizar y comprender el proceso de creación de obras de arte. Estas actividades, propuestas por Francisco Fernández y Francisco Ruiz en los procesos formativos de maestros han favorecido que los estudiantes den mayor significado a sus conocimientos geométricos, de medida, de los mosaicos en la Alhambra y en la obra de Escher
Working with Student Teachers, Concepts of Elementary Students
En esta comunicación exponemos un trabajo de aula realizada con los estudiantes de la Facultad de
Ciencias de la Educación de la Universidad de Sevilla, de la modalidad de Educación Primaria que
cursan la asignatura de Didáctica de las Ciencias Experimentales durante el curso académico
2011/2012. Con esta experiencia hacemos patente una doble necesidad. Por un lado cambiar el
modelo dominante de enseñanza de las ciencias y por otro lado ser conscientes de que el
conocimiento práctico de los docentes debe superar dicotomías del tipo: teoría-práctica,
conocimiento científico y didáctico, etc. En este contexto se describe el modelo Formación de
Profesores para Investigar la Práctica con el que pretendemos que los futuros docentes aborden sus
problemas profesionales.This document presents a classroom carried out work with students on the Faculty of Education at
the University of Seville, of primary education in course of Didactics of Experimental Sciences
during the academic year 2011/2012. A double patent is needed with this experience. On the one
hand, change the dominant model of science education and in addition be aware that the knowledge
of teachers must overcome dichotomies such as: theory and practice, scientific knowledge and training, etc. In this context it is described the Teacher Training Model to Investigate the Practice
with which we intend future teachers address their professional problems
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