Volumen 24, Número 2
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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: ... -
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 ... -
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 ... -
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 ...
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