Browsing Escuela de Química by Title
Now showing items 262-281 of 298
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Química y actividad fisiológica de metabolitos secundarios presentes en el género Amyris (Rutaceae)
(Universidad Nacional [Costa Rica], 1986-01-01)La familia Rutaceae comprende 1.600 especies agrupadas en 150 géneros, que viven en zonas templadas y tropicales del mundo, siendo numerosas en el sur de África y en Australia (Engler, 1964). La mayoría son plantas ... -
Rainfall, groundwater, and surface water isotope data from extreme tropical cyclones (2016-2019) within the Caribbean Sea and Atlantic Ocean basins
(Elsevier, 2020-06)Under a changing climate, projections estimate that over the next thirty years, extreme Tropical Cyclones (TCs) will increase in frequency, with two to three times more Category 4 and 5 hurricanes in the Atlantic basin ... -
Recovery of acetate by anion exchange with consecutive CO2-expanded methanol desorption: A model-based approach
(Elsevier BV, 2018-04-07)Production of bio-based acetate is commonly hindered by the high costs of the downstream processing. In this paper, a model is developed to describe a new method that recovers acetate salts using anion exchange resins, and ... -
Relación del contenido de polifenoles en raíces de banano (Musa AAA CV gran enano) con sus poblaciones de Radopholus similis
(Universidad Nacional (Costa Rica), 2008)Se cuantificó la cantidad de fenoles y polifenoles presentes en raíces de banano (Musa AAA), inoculadas con cantidades controladas de Radopholus similis; para esto se preparó un testigo sin nematodos y luego tratamientos ... -
Renewable fatty acid ester production in Clostridium
(Nature Communications, 2021-07-16)Bioproduction of renewable chemicals is considered as an urgent solution for fossil energy crisis. However, despite tremendous efforts, it is still challenging to generate microbial strains that can produce target biochemical ... -
Residual nitrite in processed meat products in Costa Rica: Method validation, long-term survey and intake estimations
(Elsevier Ltd, 2021-05-12)Ingestion of high amounts of nitrite due processed meat consumption could produce negative effects in human health. Here, we investigate long-term residual sodium nitrite content in processed meat products in Costa Rica ... -
Residuos de plaguicidas en sedimentos de los ríos Poás, Poasito y Colorado por la actividad agrícola del área de recarga hídrica, en la zona alta del cantón de Poás-Alajuela
(Universidad Nacional (Costa Rica), 2004)El Servicio Fitosanitario del estado (Ministerio de Agricultura y Ganadería) se ha visto en la necesidad de plantear programas de monitoreo de residuos de plaguicidas. El presente estudio consiste en la valoración de la ... -
Revisiting the fundamentals of p-nitrophenol analysis for its application in the quantification of lipases activity. A graphical update
(Universidad Nacional (Costa Rica), 2020-07-31)p-Nitrophenol (pNP) is a widely used compound for analytical determinations of several esterases (EC. 3.1.1.X), including lipases (E.C. 3.1.1.3). Most enzymatic measurements employ pNP derivatives such as ... -
Scattering of light by colloidal aluminosilicate particles Produces the unusual sky-blue color of Río Celeste (Tenorio Volcano Complex, Costa Rica)
(2013-09-18)Río Celeste (Sky-Blue River) in Tenorio National Park (Costa Rica), a river that derives from the confluence and mixing of two colorless streams-Río Buenavista (Buenavista River) and Quebrada Agria (Sour Creek)-is renowned ... -
Self-assembly study of type I collagen extracted from male Wistar Hannover rat tail tendons
(BioMed Central Ltd, 2020-11-23)Background: Collagen, the most abundant protein in the animal kingdom, represents a promising biomaterial for regenerative medicine applications due to its structural diversity and self-assembling complexity. Despite ... -
Sistema automatizado de mantenimiento preventivo, predictivo y correctivo para el equipo y maquinaria del Ingenio El General
(Universidad Nacional (Costa Rica), 2003)El proceso de globalización, así como el proceso de integración de nuestra economía ha tratado de libre comercio en diferentes países, hace que cada día el sector industrial requiera eficientizar cada vez más sus procesos ... -
Síntesis de nanoprismas ramificados de oro con potenciales aplicaciones biotecnológicas
(Universidad Nacional (Costa Rica), 2020)Actualmente, las nanopartículas de oro son una interesante alternativa para ser utilizadas en diversas aplicaciones. Este trabajo se basó en la síntesis de nanopartículas anisotrópicas de oro, utilizando vesículas a base ... -
Síntesis de un bioplaguicida con potencial actividad antimicrobiana a partir de una matriz de quitosano modificada con cinamaldehído
(Universidad Nacional (Costa Rica), 2007)En la actualidad es cada vez más común el uso de bioplaguicidas, que son sustancias derivadas de materiales naturales o animales, que se caracterizan por presentar menor toxicidad que los productos sintéticos, ser efectivos ... -
Spatial and Temporal Variation of Stable Isotopes in Precipitation across Costa Rica: An Analysis of Historic GNIP Records
(2013-11-27)The location of Costa Rica on the Central American Isthmus creates unique microclimate systems that receive moisture inputs directly from the Caribbean Sea and the Pacific Ocean. In Costa Rica, stable isotope monitoring ... -
Stable isotopes reveal groundwater to river connectivity in a mesoscale subtropical watershed
(Taylor and Francis Ltd., 2021)The Corumbataí River basin (São Paulo, Brazil) has a critical situation regarding water availability due to the intensive use to support agriculture and urbanization, requiring scientific information to face water demand. ... -
Stable isotopic characterizacion of nitrate wet deposition in the tropical urban atmosphere of Costa Rica
(Springer, 2021-07-13)Increasing energy consumption and food production worldwide results in anthropogenic emissions of reactive nitrogen into the atmosphere. To date, however, little information is available on tropical urban environments where ... -
Stable isotopic characterization of nitrate wet deposition in the tropical urban atmosphere of Costa Rica
(Research Square, 2021)Increasing energy consumption and food production worldwide results in anthropogenic emissions of reactive nitrogen into the atmosphere. To date, however, little information is available on tropical urban environments where ... -
Synthesis of Dihydroindolo[2,3-c]carbazole as Potential Telomerase Inhibitor
(Journal of Heterocyclic Chemistry vol.53 no.3 762-766 2015, 2015-05-27)The dictyodendrins A-E were the first marine natural products that show inhibition of telomerase. A versatile and convergent route was described for the synthesis of derivatives of these pyrrolo[2,3-c]carbazole alkaloids ... -
The effect of solution environment and the electrostatic factor on the crystallisation of desmotropes of irbesartan
(Royal Society of Chemistry, 2019)The experimental conditions necessary for stabilising irbesartan (IBS) tautomers in solution and selectively obtaining the desmotropic crystal forms are presented herein. 1H and 2H tautomers were stabilized in specific ... -
The manufacture and properties of oil palm and pineapple leaf fiberboard panels
(WIT Transactions on Ecology and the Environment, 2014)Particleboards were manufactured from oil palm fruit, the oil palm mesocarp fiber of Elaeis guineensis, the leaves of pineapple (Ananas comosus) and the sawdust from three fast-growing species of trees (Gmelina arborea, ...
