Browsing Artículos científicos by Title
Now showing items 121-140 of 241
-
Fagodisuasión de extractos de Brugmansia candida (Solanaceae) en larvas de Hypsipyla grandella (Lepidoptera: Pyralidae)
(Universidad de Costa Rica (Costa Rica), 2018)Hypsipyla grandella is a key forest pest in Latin America and the Caribbean, where it has precluded attempts to establish commercial plantations of mahoganies (Swietenia spp.) and cedars (Cedrela spp.). In the search for ... -
First Measurements of Biogenic Hydrocarbons in Air in a Tropical Cloudy Forest, Monteverde, Costa Rica
(David Publishing Compan, 2011)Measurements of biogenic hydrocarbons in ambient air were carried out during 2008 in a cloud y tropical forest in Monteverde, Costa Rica. Isoprene, α-pinene, β-pinene, 3-carene, d-limonene and γ-terpinene were sampled by ... -
First measurements of methyl tert-butyl ether (MTBE) in the ambient air in San Jose, Costa Rica
(2014)A great interest has arisen in establishing the impact of organic compounds on human health and air quality, especially those compounds emitted by automotive traffic. Knowledge of urban air pollutant concentrations is ... -
Frontiers in páramo water resources research: A multidisciplinary assessment
(Elsevier (Países Bajos), 2023)Interdisciplinary knowledge is necessary to achieve sustainable management of natural resources. However, research is still often developed in an exclusively disciplinary manner, hampering the capacity to holistically ... -
Fuentes antropogénicas y naturales de contaminación atmosférica: estado del arte de su impacto en la calidad fisicoquímica del agua de lluvia y de niebla
(Tecnológico de Costa Rica, 2021-01)En este artículo se describe el estado del arte en relación con la influencia de las fuentes naturales y antropogénicas de los contaminantes atmosféricos en las características fisicoquímicas del agua de niebla y de lluvia ... -
Fungal biosynthesis of lignin-modifying enzymes from pulp wash and Luffa cylindrica for azo dye RB5 biodecolorization using modeling by response surface methodology and artificial neural network
(Elsevier, 2020-06-04)This study demonstrates the evaluation between the artificial neural network technique coupled to the genetic algorithm (ANN-GA) and the response surface methodology (RSM) for prediction of Reactive Black 5 (RB5) decolorization ... -
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 ...