Browsing Artículos científicos by Title
Now showing items 127-146 of 254
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Gestión de reactivos químicos en laboratorios de la Universidad Nacional
(Universidad Nacional (Costa Rica), 2013)Durante el 2008-2009 se realizó un diagnóstico de la gestión de reactivos químicos en los laboratorios de docencia e investigación de la Universidad Nacional, utilizando las siguientes ... -
GPS PrecipitableWater Vapor Estimations over Costa Rica: A Comparison against Atmospheric Sounding and Moderate Resolution Imaging Spectrometer (MODIS)
(MDPI, 2019)The quantification of water vapor in tropical regions like Central America is necessary to estimate the influence of climate change on its distribution and the formation of precipitation. This work reports daily estimations ... -
Green Solvents in Carbohydrate Chemistry: From Raw Materials to Fine Chemicals
(American Chemical Society, 2015)In recent decades, there has been an increasing effort to reduce the use of fossil fuels and oil derivatives, to decrease environmental pollution, and to counteract global warming. The use of biomass as raw material is ... -
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 ... -
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 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 ... -
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 ... -
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, ... -
Identifying groundwater recharge connections in the Moscow (USA) sub-basin using isotopic tracers and a soil moisture routing model
(Springer, 2016)Globally, aquifers are suffering from large abstrac tions resulting in groundwater level declines. These declines can be caused by excessive abstraction for drinking water, irrigation purposes or industrial use. Basaltic ... -
Impacto nacional e internacional en la promoción de las vocaciones científicas del Programa Mejoramiento de la Enseñanza de la Química(PMEQ)
(Universidad Nacional (Costa Rica), 2013)La labor extensionista de la Escuela de Química de la UNA en Costa Rica se ha visto reflejada desde sus inicios, en gran medida, por las actividades realizadas desde el Programa de Mejoramiento de la Enseñanza de la ... -
Implementing unmanned aerial systems equipped with Sniffer4D payloads for volcanic gas detection and data analysis used for forecasting volcanic eruptions
(Mersin Üniversitesi (Turquía), 2022)A consistent volcanic monitoring program is crucial to the safety of the population and the efficiency of the nation. Costa Rica´s National Commission for Risk Prevention the CNE helps manages this responsibility. Universidad ... -
Increased fibroblast metabolic activity of collagen scaffolds via the addition of propolis nanoparticles
(MDPI AG, 2020-07-13)Propolis natural extracts have been used since ancient times due to their antioxidant, anti-inflammatory, antiviral, and antimicrobial activities. In this study, we produced scaffolds of type I collagen, extracted from ... -
Influence of iron oxide nanoparticles on the rheological properties of hybrid chitosan ferrogels
(Elsevier, 2009)Magnetite nanoparticles have been successfully synthesized in the presence of chitosan using an in situ coprecipitation method in alkali media. This method allows obtaining chitosan ferrogels due to the simul taneous ...