Departamento de Física
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Dairy wastewater treatment by anaerobic fixed bed reactors from laboratory to pilot-scale plant: A case study in Costa Rica operating at ambient temperature
(Springer, 2013)The effect of hydraulic retention time in a range from 1.0-5.5 days was evaluated in a laboratory scale anaerobic fixed bed reactor packed with a hybrid material composed of tire rubber and zeolite. Under these conditions, ... -
Design, construction and experimental study of electric cum solar oven-II
(1989)As in many developing countries,35-401 of the population of Costa Rica still use firewood for domestic cooking.Considering the fact that Costa Rica is blessed with good sunshine,good hydroelectric potential,and there ... -
Design, construction and study of a hybrid solar food processor in the climate of Costa Rica
(Elsevier, 2007)During the last 25 years, the author has designed, constructed, studied and promoted solar oven, hybrid solar/electric oven, solar oven cum drier, solar cooker cum water heater and solar still. In different parts of the ... -
An evaluation of variables affecting the stability and performance of down-flow anaerobic fixed bed reactors treating piggery wastewater
(Taylor & Francis, 2006)The influence of the most important variables on the stability and performance of down-flow anaerobic fixed bed reactors treating piggery wastewater after primary sedimentation was evaluated at HRT in the range of 1-6 d ... -
High Specific Capacity of Lithium–Sulfur Batteries with Carbon Black/Chitosan- and Carbon Black/Polyvinylidene Fluoride-Coated Separators
(MDPI, 2022-03-17)In this research, the shuttle effect and the low sulfur activation of lithium–sulfur batteries were mitigated by coating the cathode side of Celgard 2400 separators with mixtures of carbon black/chitosan or carbon ... -
Aplicaciones del modelo de Barbaro et al. para el cálculo de la radiación solar global por medio de estimaciones de los componentes directos y difusos, en Limón y Puntarenas, Costa Rica, para el período 1970-1972
(Universidad Nacional (Costa Rica), 1987-01-01)El presente trabajo utiliza un modelo atmosférico propuesto por Barbaro et al., para el cómputo de la radiación solar global a través de las estimaciones de las componentes directa y difusa, en Limón y Puntarenas, Costa ... -
Estudio experimental y teórico de un horno solar práctico en el clima de Costa Rica
(Universidad Nacional (Costa Rica), 1986-01-01)Alrededor del 40% de la población costarricense utiliza leña para cocinar, lo que ha contribuido en buena medida al problema de la deforestación. Esto, junto con otras razones, le dio una idea al autor para diseñar, construir ... -
Estudio preliminar de tres modelos de destiladores solares para producir sal y agua potable
(Universidad Nacional (Costa Rica), 1986-01-01)Hemos construido tres alambiques solares de 0,5-1,0 m 2 de área para producir agua salada y potable, utilizando tecnología local y materiales locales. Hemos estudiado el rendimiento térmico de estos alambiques en función ... -
Determinación de la Altura dinámica a partir de perfiles de temperatura
(Universidad Nacional (Costa Rica), 1986-01-01)La altura dinámica se calcula solo a partir de los datos de temperatura mediante el uso de una relación TS media para proporcionar valores de salinidad. El método se ha aplicado a datos de cruceros: EASTROPIC (1967) y ... -
Coastal currents in the Eastern Gulf of Tehuantepec from coastal altimetry
(Advances in Space Research, 2018-06-02)we study the seasonal and interannual variability of the coastal currents along the eastern shelf of the Gulf of Tehuantepec. We use sea level from coastal altimetry distributed by the Centre de Topographie des Oceans et ... -
Properties of low-lying states in 65Co from lifetime measurements
(American Physical Society, 2019)The low-energy structure of Co65 was studied by means of γ-and fast-timing spectroscopy at the ISOLDE/CERN facility. The known level scheme of Co65 populated following the β-decay of Fe65 was expanded. The experimental ... -
Electrochemical Characterization of Mancozeb Degradation for Wastewater Treatment Using a Sensor Based on Poly (3,4-ethylenedioxythiophene) (PEDOT) Modified with Carbon Nanotubes and Gold Nanoparticles
(MDPI AG, 2019)Mancozeb is a worldwide fungicide used on a large scale in agriculture. The active component and its main metabolite, ethylene thiourea, has been related to health issues. Robust, fast, and reliable methodologies to quantify ... -
The magnetic dispersion
(Editorial de la Universidad Nacional, 1985-01-01)We present a study of the elastic scattering of an electron in a constant homogeneous magnetic field. The dependency of the cross section on the electron spin orientation is given. If the spin polarization is along or ... -
Influence of the Madden–Julian oscillation on Costa Rican mid-summer drought timing
(John Wiley and Sons Ltd, 2019)The Central American mid-summer drought (MSD) is the decline of precipitation during the middle of the wet season (July and August) over Central America and southern Mexico. It affects agriculture and favours the initiation ... -
Infragravity wave energy partitioning in the surf zone in response to wind-sea and swell forcing
(MDPI AG, 2019)An alongshore array of pressure sensors and a cross-shore array of current velocity and pressure sensors were deployed on a barred beach in southwestern Australia to estimate the relative response of edge waves and leaky ... -
Cladocera (Crustacea, Branchiopoda) of a temporary shallow pond from northern Colombia
(Universidad Nacional Mayor de San Marcos, 2019)Eighteen species of cladocerans are recorded from a temporary pond in northern Colombia; 12 of these records are new for La Guajira Department: Diaphanosoma brevireme Sars, 1901, D. dentatum Herbst, 1968, Sarsilotona ... -
Medidas topográficas en superficies atómicamente planas en condiciones ambiente mediante un microscopio de efecto túnel, un enfoque didáctico
(Universidad Nacional de Costa Rica, 2019-01-31)Uno de los grandes avances en la nanotecnología fue el desarrollo del microscopio de efecto túnel, herramienta que ha permitido poder manipular átomos, moléculas, estudiar el transporte electrónico en un solo átomo e incluso ... -
Deforestation processes in the livestock territory of La Vía Láctea, Matagalpa, Nicaragua
(Taylor and Francis Ltd., 2019-05-04)Land-use change is considered one of the main causes of environmental degradation. Thus, its analysis will allow stakeholders to make reasonable decisions for land management. The objective of the present study was ... -
Raman spectroscopy as a tool to evaluate oxygen effects on the response of polymer gel dosimetry
(Elsevier, 2019-05-06)Currently, advanced dosimeters like polymer gels are capable of obtaining reliable and accurate 3D dose distributions from correlations with the different polymerization degrees induced by incident radiation. Samples of ... -
Sobre el transporte de partículas en cuerpos oceánicos semicerrados (ING)
(Universidad Nacional (Costa Rica), 1984-07-01)El flujo residual ha mostrado tener una función relevante en el transporte de partículas en suspensión, larvas y algunos contaminantes, principalmente. Este se establece como consecuencia de la interacción entre la onda ...
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