Química
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Elaboración de un lubricante potencialmente biodegradable de uso industrial a partir de quitosano, aceite de ricino y aditivos antioxidantes de origen natural
(2023-09-07)En la actualidad, la tecnología de los lubricantes se enfoca hacia la protección del medio ambiente. Sin embargo, la mayoría de los actuales lubricantes de uso industrial están conformados por aceites minerales como matriz ... -
Differential volatile organic compound expression in the interaction of Daldinia eschscholtzii and Mycena citricolor
(2023)Fungi exhibit a wide range of ecological guilds, but those that live within the inner tissues of plants (a.k.a. endophytes) are particularly relevant due to the benefits they sometimes provide to their hosts, such as ... -
Caracterización bioquímica y espectroscópica de la interacción del aptámero con componentes de la espora de clostridium difficile y la superficie de óxido de grafeno
(2023)Clostridioides difficile es un patógeno bacteriano formador de endosporas que causa infecciones asociadas al uso de antibióticos, primordialmente en entornos clínicos. Las esporas de C. difficile son altamente resistentes ... -
Alternative approaches to determine the efficiency of biomixtures used for pesticide degradation in biopurification systems
(2018)Biopurification systems were developed for the biological treatment of pesticide-containing wastewaters originated from agricultural production. They are aimed at reducing point-source contamination related to the ... -
Determination of adulterants of cocaine in Real banknotes in Brazil by HPLC-DAD
(2022)Cocaine is a tropane alkaloid extracted from coca leaves, a common bush found in Andean regions of South America. Many medicines are added to the final product to increase the profits, keeping similar or higher effects ... -
Development of an extraction method for the determination of inorganic anions (chloride, sulfate and phosphate) in edible oils from different origins by ion chromatography
(2018)The present work reports the development of ion chromatography conductivity based detection analytical method for the determination of some inorganic anions (chloride, sulfate and phosphate) in vegetable oils. The analytes ... -
Determination of acetate and formate in vegetable oils by ion chromatography after multivariate optimization of the extraction process using a Doehlert design
(2018)In this work, we present the development of a method for the determination of acetate and formate in vegetable oils by ion chromatography with conductometric detection following their extraction from samples using a diluted ... -
Microwave-Assisted Extraction of Chloride Followed by Ion Chromatography as an Alternative to the ASTM D6470 Method for the Determination of Crude Oil Salinity
(2020)The presence of chloride in crude oil can result in a number of drawbacks, with technical and economic impacts on the production of petroleum derivatives. For this reason, it must be carefully monitored in this kind of ... -
Determinación colorimétrica de hierro en agua potable mediante la utilización de imágenes obtenidas con el teléfono celular
(2023-03-09)La colorimetría de imágenes digitales se basa en la extracción de coordenadas de color de imágenes captadas con dispositivos como: escáneres, cámaras digitales y teléfonos celulares. El hierro es uno de los elementos más ... -
Desarrollo de sensores electroquímicos para la determinación de drogas sintéticas en fluidos biológicos y muestras de incautación
(2023-07-09)La cantidad de nuevas sustancias psicoactivas, popularmente conocidas con términos como: drogas emergentes, drogas de diseño, drogas sintéticas o drogas recreativas, aumenta en el mercado global de las drogas cada año. El ... -
Drying kinetics as Tool for the Assessment of Dynamic Porosity of Catalyst-Support Materials
(2018)Critical drying fraction data (xc) were obtained for a series of porous materials, frequently used as supports for heterogeneous catalysts. This kinetic parameter correlates well with the secondorder rate constants for ... -
Reactive Intermediates in the Photolysis of Furan, Thiophene and Pyrrole: The Dewar and the Ring Contraction forms
(1985-07-14)Five-member aromatic heterocycles have been known to undergo scrambling of the ring atoms upon photolysis. These reactions are characterized by their selectivity and several mechanisms have been proposed involving the ... -
Un método cromatográfico para la determinación de sacarosa en bebidas comerciales con azúcar añadida
(2023)Derivado del excesivo consumo de azúcar en la sociedad costarricense y la problemática derivada, en gran parte, por el consumo de bebidas comerciales con contenido alto de sacarosa, y su consecuente efecto sobre la salud ... -
Chemical Investigations of Tropical Medicinal Plants, XXI [1] Long Chain Alkyl Esters of Ferulic and p-Coumaric Acid from Bauhinia manca
(1986)Bauhibia manca (Leguminosae) is a vine growing in the lowland forests of Costa Rica and Panama [2]. In Costa Rica, an infusion of the stems and leaves is taken as an astringent and diuretic, and as a remedy for diabetes[3,4] ... -
Síntesis de derivados de la fenantrenoquinona con compuestos difuncionales
(1978)En este trabajo se comparó la reactividad del grupo metileno (-CH2-) en reacciones de condensación. Cuando el grupo metileneo está entre dos grupos carbonilos (compuestos 1,3-dicarbonílicos) la reactividad es mayor como ... -
Síntesis de nuevas Dibenzo[f,h]cinolinas
(1985)Synthesis of new Dibenzo[f,h]cinnolines. Condensation of the compounds 9-acetonyl-9-hydroxy-10-oxo-9,10-dihydrophenanthrene (2) and 9-(2-cyclopentanonyl)-9-hydroxy-10-oxo-9,10-dihydrophenanthrene (3) with hydrazine produced ... -
La estructura de la Diacetonafenantrenoquinona
(1971)The substance, diacetonephenanthrenequinone, long believed to have structure I or II, is found to have structure IV according to modern spectroscopic methods and chemical behavior. -
El Uso de Plaguicidas en América Latina: Tendencias e implicaciones ambientales (Memoria Encargada)
(1988)The current demand for pesticides in Latin America exceeds US $ 2000 million in value. Up to 1990, consumption is expected to rise by 7 to 12%. The use of pesticides has been fully accepted in Lati America as a readily ... -
Evaluación de los efectos de la contaminación atmosférica y el ángulo de exposición sobre la corrosión del acero de bajo carbono y acero galvanizado en la región del Valle Central Occidental (VCO) de Costa Rica
(2023-05)Costa Rica is a country that imports its metallic materials, this makes the evaluation of its corrosion losses of special interest, since they represent an average of 3% of the GDP. In particular, atmospheric corrosion is ... -
Reacciones del 2,2´-Tio-benzimidazol con Sulfato de Dimetilo
(1979)Se efectuó la reacción del 2,2´-tiobis-benzimidazol con el sulfato de dimetilo por pasos. Se comprobó la formación de: 1,1´-dimetil-2,2´-tiobis-benzimidazol (2) y del diperclorato del 1,1´,3,3´-tetrametil-2,2´-tiobisbenz ...
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