Browsing Escuela de Química by Title
Now showing items 280-299 of 489
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Green Synthesis of Gold and Silver Nanoparticles from Plant Extracts and Their Possible Applications as Antimicrobial Agents in the Agricultural Area
(MDPI AG, 2020-09-07)Currently, metal nanoparticles have varied uses for different medical, pharmaceutical, and agricultural applications. Nanobiotechnology, combined with green chemistry, has great potential for the development of novel and ... -
Green Synthesis of Metal Nanoparticles from Plant Extracts, and Their Possible Application as Antimicrobial Agents in the Agricultural Area
(Multidisciplinary Digital Publishing Institute (MDPI) (Suiza), 2020)Currently, metal nanoparticles have varied uses for different medical, pharmaceutical, and agricultural applications. Nano-biotechnology combined with green chemistry has great potential for the development of novel and ... -
Groundwater age and recharge processes in a tropical volcanic aquifer
(Universidad Nacional (Costa Rica), 2019)La recarga de agua subterránea en acuíferos volcánicos altamente fracturados sigue siendo poco conocida en los trópicos húmedos. El rápido crecimiento demográfico y los cambios no regulados en el uso de la tierra dieron ... -
Groundwater and surface water connectivity within the recharge area of Guarani aquifer system during El Niño 2014–2016
(Wiley & Sons, 2018)Recharge areas of the Guarani Aquifer System (GAS) are particularly sensitive and vulnerable to climate variability; therefore, the understanding of infiltration mechanisms for aquifer recharge and surface run‐off generation ... -
Groundwater flow modeling using iMOD for Barva and Colima aquifers in the Central Valley of Costa Rica: validation of a conceptual model using tracer data
(Universidad Nacional de Salta, 2018)A stationary numerical model of groundwater flow was developed using iMOD to better understand the recharge processes within Barva and Colima aquifers (BCS), located in the northwestern region of the Central Valley of Costa ... -
Groundwater recharge mechanisms inferred from isoscapes in a complex tropical mountainous region
(AGU Publications, 2016-05-23)Stable isotope variations and groundwater recharge mechanisms remain poorly understood across the tropics, particularly in Central America. Here stable isotopes (δ18O and δ2H) in groundwater, surface water, and rainfall ... -
Hacia una gestión de reactivos y residuos químicos en los laboratorios de docencia de la Escuela de Química en la Universidad Nacional
(Universidad Nacional (Costa Rica), 2012)Las actividades académicas que se realizan en la Escuela de Química hacen indispensable la puesta en marcha de acciones orientadas a la consolidación de una gestión de los reactivos y residuos, especialmente en los ... -
Headwaters drive streamflow and lowland tracer export in a large-scale humid tropical catchment
(John Wiley and Sons Ltd, 2020)Headwaters are generally assumed to contribute the majority of water to downstream users, but how much water, of what quality and where it is generated are rarely known in the humid tropics. Here, using monthly monitoring ... -
Hydroclimatic and ecohydrological resistance/resilience conditions across tropical biomes of Costa Rica
(John Wiley & Sons (Estados Unidos), 2017)Water resources management in the tropics is challenged by climate variability and unregulated land use change and their impacts on the complex interactions between vegetation, soil, and atmosphere. This study focuses ... -
Hydrogeochemical baseline in a human altered landscape of the Central Pacific coast of Costa Rica
(Springer Nature, 2020)Abstract Groundwater pollution in tropical and human-altered coastal landscapes is receiving novel attention due to decreasing in annual recharge as a consequence of recurrent droughts and overexploitation, whereby saline ... -
Hydrogeological responses in tropical mountainous springs
(Taylor and Francis Ltd., 2018)This study presents a hydrogeochemical analysis of spring responses (2013–2017) in the tropical mountainous region of the Central Valley of Costa Rica. The isotopic distribution of δ18O and δ2 H in rainfall resulted ... -
Hydrological dataset of a sub-humid continental plain basin (Buenos Aires, Argentina)
(Elsevier, 2020)The Chaco-Pampean Plain (Argentina) is the strongest eco- nomic region and the most inhabited in the country, comprising approximately 66% of the country’s population (26,500 million) [1] . In this region, surface slopes ... -
Hydrometeorological Factors Controlling the Stable Isotopic Composition of Precipitation in the Highlands of South Ecuador
(American Meteorological Society (Estados Unidos), 2022-07)Knowledge about precipitation generation remains limited in the tropical Andes due to the lack of water stable isotope (WSI) data. Therefore, we investigated the key factors controlling the isotopic composition of precipitation ... -
Identificación de explosivos Orgánicos en Indicios Post-Explosión mediante GC-MS y GC-NPD
(Tecnológico de Costa Rica, 2020-07)Se implementó y validó un método para la identificación de explosivos por medio de cromatografía de gases acoplada a un detector de espectrometría de masa (GC-MS) y por cromatografía de gases de doble columna acoplada a ... -
Identificación de lignanas en hojas de Rollinia mucosa (JACQ) bail. Annonaceae
(Universidad Nacional (Costa Rica), 2001)El extracto etanólico obtenido por maceración de las hojas de Rollinia mucosa fue extraído sucesivamente con los siguientes disolventes de polaridad creciente: hexano, cloroformo y acetato de etilo. Diluciones alcohólicas ... -
Identificación de metabolitos secundarios con actividad antimicrobiana y capacidad antioxidante presentes en mieles de abejas sin aguijón procedentes de Costa Rica
(Universidad Nacional (Costa Rica), 2012-11)Valora mediante cromatografía en capa fina (CCF) la presencia de metabolitos secundarios con capacidad antioxidante y actividad antimicrobiana en 63 extractos en fase orgánica de mieles de abejas sin aguijón procedentes ... -
Identificación de Metabolitos Secundarios Concentrados en el Extracto Hidroalcohólico de Starchytarpheta mutabilis
(Universidad de Nacional (Costa Rica), 2003)La presente investigación describe el aislamiento y la identificación estructural de dos metabolitos y la identificación estructural de dos metabolismos secundarios que se concentran en el extracto hidroalcohólico obtenido ... -
Identificación de un principio presente en las hojas de Satureja viminea (Lamiaceae)
(Universidad Nacional (Costa Rica), 2007)La planta Satureja viminea, también conocida como Micromeria viminea Urb y M. obovata Venth entre los principales sinónimos (Morton, 1981) y conocida en nuestro país como menta; pertenece a la familia Lamiaceae, que ... -
Identificación y caracterización de quitooligómeros obtenidos por hidrólisis química del quitosano proveniente del camarón camello real (Heterocarpus vicarius)
(Universidad Nacional (Costa Rica), 2006)En esta investigación se evaluó la utilización del quitosano derivado del camarón camello real (Heterocarpus vicarius) para la obtención de quitooligómeros de bajo peso molecular. El camarón camello real corresponde a una ... -
Identification and Investigation of Autolysin Genes in Clostridium saccharoperbutylacetonicum Strain N1-4 for Enhanced Biobutanol Production
(American Society for Microbiology, 2021-03-11)Biobutanol is a valuable biochemical and one of the most promising biofuels. Clostridium saccharoperbutylacetonicum N1-4 is a hyperbutanol-producing strain. However, its strong autolytic behavior leads to poor cell stability, ...