Revista de Ciencia y Tecnología: Envíos recientes
Mostrando ítems 41-60 de 79
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Climatología del viento y oleaje frente a las costas de Costa Rica, parte 1.
(2009-04-29)The climatologically behavior of the wind and waves is studied around the Costa Rica's coasts using re-analysis data from wave forecasting numeric model. It is found that the wind in the Caribbean coasts of Costa Rica is ... -
Importancia de la batimetría de las planicies basales en la propagación de tsunamis transoceánicos
(2009-04-29)The initial form of a tsunami originated by an homogeneous seismic source consists on a simple wave front. While the tsunami propagates in deep water, this simple form suffers several modifications by the tsunami's interaction ... -
Nuevo método para la obtención de quitina
(2009-04-29)A simple method for the isolation of chitin is described. It is based on the solubility of the biopolymer in concentrated aqueous HCl at low temperature. The solubility diagram of the system chitin-HCl-H2O is discussed as ... -
Síntesis y caraterización del ligando tris-(2-tiosalicilamidoetil)amina y sus complejos de hierro e indio
(2009-01-13)The coordination chemistry of the hexadentate ligand, tris(2-thiosalicylamidoethyl)amine, (LH3), was studied. The reaction of the ligand trianion with iron(III) and indium(III) yields monomeric hexacoordinate complexes, ... -
Lignanos de Zanthoxylum acuminatum
(2009-01-13)From the aerial parts of Zanthoxylum acuminatum (Rutaceae) collected in Upala, Alajuela, Costa Rica were isolated the known lignans hinokinin, (+)-asarinin, (+)- piperitol, (+)-kobusin, and epi-kobusin. In addition to the ... -
Nuevas lactonas sesquiterpénicas de Perymenium grande
(2009-01-13)Three new sesquiterpenes lactonaes were isolated from the aerial parts of Perymenium grande Hemsl. (Asteraceae), collected around Rincón de la Vieja Volcano, Costa Rica. In addition to the three new lactones 1, 3 and 5; ... -
Identificación de modelos de orden reducido a partir de la curvatura de reacción del proceso
(2009-01-13)A general identification procedure is given, for first and second orders plus time delay models, that uses two or three arbitrary points over the process reaction curve. Two simplified versions of the methods are described: ... -
Aplicación de la tomografía axial computarizada para la detección de bolsas de humedad en madera seca de gmelina arborea (roxb.)
(2009-01-13)Due to its excellent growth rate and productivity, Gmelina arborea (Roxb.) is widely used for commercial reforestation in Costa Rica. However during the lumber drying process, the wooden boards show non-uniform values of ... -
Kinetics of the fischer esterification of palm fatty acids with isopropanol and butyl-cellosolve
(2009-01-13)Fischer esterification of the mixture of palm fatty acids can be achieved in 80% conversion, under conditions of reactive distillation and methanesulphonic acid as catalyst. The volatility of the H2O/alcohol azeotrope ... -
La cinética de la esterificación de ácidos carboxílocos es de segundo orden con repecto al alcohol
(2009-01-13)Esterification of carboxylic acids with alcohols is considered as AAC2 type reaction. The specific rate of esterification of acetic acid with methanol, in mixtures of acetonitrile-methanol showed a quadratic dependence on ... -
Modelación de la emisión de compuestos orgánicos volátiles en sistemas de aereación mediante un modelo de dos zonas simplificado
(2009-01-13)A new simplified mass-transfer model was developed to describe the volatile organic compounds (VOC) emission rates from diffused aeration systems. The model takes into consideration that the VOC mass transfer occurs in two ... -
EEfecto de contaminantes sobre la transferencia de oxígeno en sistemas de aeración analizado mediante un modelo de dos zonas simplificado
(2009-01-13)A series of unsteady-state reaeration tests were performed in a 1000 l tank at 1-10-3 normal m3/s diffused-air flow rate and 298,65 K water temperature. Three different types of impurities: soybean oil, surfactant, and ... -
Modelación de la transferencia de oxágeno en sistemas de aereación mediante un modelo de dos zonas simplificado
(2009-01-13)A new two zone simplified oxygen mass-transfer model with an analytical solution was proposed and used to analyze the unsteady state reaeration data of diffused reaeration systems in order to find the volumetric mass-transfer ... -
La lógica difusa en ingeniería: principios, aplicaciones y futuro
(2009-01-13)Fuzzy logic is a mathematical tool that mimics the way humans manage and process information. It is a method of great simplicity for processing of information, decision making and process control. This article discusses ... -
Curvatura en teorías generalizadas de Yang-Mills
(2009-01-13)The curvature in R1+3 spaces with a generalized Yang-Mills connection is studied and the results are analyzed. Other options borne by modifications of the base space are also studied and commented. The present situation ... -
Las cuerdas magnéticas
(2009-01-13)The conception of the magnetic string is presented; it is an infinitely thin bundle of magnetic flux lines. They are surrounded by a film of current that rotates around them, and are a solution of Maxwell’s equations. Their ... -
Monitoreo ambiental con detectores termoluminiscentes en Costa Rica
(2009-01-13)Using thermoluminiscent dosimeters (Harshaw TLD-200) the first set of Costa Rica data on absorbed doses in air from natural radiation is obtained. During the period September 1996 through October 2000 eight different sites ... -
Caracterización y determinación del potencial Aterogénico de quesos producidos en Costa Rica
(2009-01-13)Cardiovascular diseases have been one of the main causes of mortality during the past years in Costa Rica. Many risk factors associated to these disorders include the intake of high-fat diets, being cheese an example of ... -
Manejo responsable de los desechos radiactivos en la Universidad de Costa Rica
(2009-01-13)The Radiation Safety Program (RSP) of the University of Costa Rica established in 1990, handles the radioactive waste generated at the University. A centralized storage waste room is used by the Atomic, Nuclear and Molecular ... -
Visualización científica de lentes gravitacionales
(2011-02-16)Concepts related to gravitatonal lenses are discussed and applied to develope an interactive visualization tool that allow us to investigate them. Optimization strategies were performed to elaborated the tool. Some results ...