Browsing Física by Title
Now showing items 1-20 of 44
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A study of a coronal hole associated with a large filament eruption
(2017)We report the results of a detailed study of an equatorial coronal hole and a dimming region related to the eruptions of a nearby large filament and subsequent coronal mass ejections (CMEs). The dynamic eruptions of the ... -
A thermodynamic cycle for the solar cell
(2017-01-06)A solar cell is a heat engine, but textbook treatments are not wholly satisfactory from a thermodynamic standpoint, since they present solar cells as directly converting the energy of light into electricity, and the current ... -
Los albores de la física y el desarrollo de la meteorología en Costa Rica
(2002)El siguiente artículo describe algunos aspectos del desarrollo de la física en Costa Rica, con énfasis en el siglo XIX. El trabajo está basado en una investigación bibliográfica de fuentes históricas, donde se compilaron ... -
Algunas ideas para lograr un mayor desarrollo científico y tecnológico en Costa Rica
(2000)El propósito de este capítulo, el cual está basado en el trabajo de Fernández y Páez (2000), es describir las actividades en Ciencias Espaciales que se están llevando a cabo en Costa Rica, estas actividades están centradas ... -
Chandler wobble: Stochastic and deterministic dynamics
(2016-09-18)We propose a model of the Earth’s torqueless precession, the “Chandler wobble,” as a self-oscillation driven by positive feedback between the wobble and the centrifugal deformation of the portion of the Earth’s mass contained ... -
Cosmological Exact Solutions Set of a Perfect Fluid in an Anisotropic Space-Time in Petrov Type D
(2016-06)In this document a set of exact solutions is obtained by using the model of a perfect fluid on an homogeneous and anisotropic space-time that belongs to (Local Rotational Symmetry) Petrov’s type D. This solutions represent ... -
Design and Characterization of a High Vacuum Metals Deposition System based on Electron Beam Evaporation
(2010-08-03)We describe a high vacuum metals deposition system based ona variation of a pendant-drop type electron beam evaporator.This system uses a Molybdenum crucible as an evaporantinstead of a rod or wire usually used in ultrathin ... -
Diseño y caracterización de un enfriador de átomos de tipo “desacelerador Zeeman”
(2016)Nosotros presentamos un método que utiliza simultáneamente dos modelos matemáticos, con el objetivo de optimizar el diseño de un desacelerador Zeeman, con miras a la implementación de átomos ultrafríos a la física del ... -
Distribución espacial de impactos de eventos hidrometeorológicos en América Central
(2016)América Central está expuesta a la ocurrencia de eventos hidrometeorológicos a lo largo del año y los impactos que estos pueden provocar van a estar mayormente localizados en áreas donde las variables tanto naturales como ... -
Do Magnetic Fields Destroy Black Hole Accretion Disk g-Modes?
(2015-08-04)Diskoseismology, the theoretical study of normal-mode oscillations in geometrically thin, optically thick accretion disks, is a strong candidate for explaining some quasi-periodic oscillations in the power spectra of many ... -
El inflatón complejo
(1999) -
El inflatón complejo
(1999) -
Electronic structure of silicon-based nanostructures
(2007-08-30)We have developed a unifying tight-binding Hamiltonian that can account for the electronic properties of recently proposed Si-based nanostructures, namely, Si graphene-like sheets and Si nanotubes. We considered the sp3s∗ ... -
Estimation of Silicon Nanocrystalline Sizes from Photoluminescence Measurements of RF Co-Sputtered Si/SiO2 Films
(Materials Research Society Symposium Proceedings 737 (2003), 2003)A stochastic distribution of nanocrystalline sizes model is applied to fit photoluminescence (PL) spectra of luminescent Si nanocrystals in a Si/SiO2 matrix synthesized by RF co-sputtering on the top of quartz substrates. ... -
Exact solution of an ekpyrotic fluid and a primordial magnetic field in an anisotropic cosmological space-time of Petrov D
(2017)This document obtained and analyzed an exact solution of an ekpyrotic fluid (P = 5/3 µ) and a primordial magnetic field, so that the latter does not induce currents or electric fields. It is determined that the main role, ... -
Exact Solutions of a Chaplygin Gas in an Anisotropic Space-Time of Petrov D
(2017)This document obtains two exact solutions to the anisotropic spacetime of Petrov D by using the model of a perfect fluid. These solutions represent a scenario of a universe in which the pressure P and the energetic density ... -
(Hydro)climatological studies of climate change and variability in Central America
(2018-06-26)This is the presentation of Hugo Hidalgo at the CORDEX Central America and South America Training Workshop on Downscaling Techniques, in La Paz, Bolivia, June 25 to 27, 2018. -
Interaction of a quantum field with a rotating heat bath
(2018-08-01)The linear coupling of a rotating heat bath to a quantum field is studied in the framework of the Markovian master equation for the field's non-unitary time evolution. The bath's rotation induces population inversion for ...