Browsing Artículos científicos by Title
Now showing items 87-106 of 191
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Evaluación del funcionamiento de un sistema alternativo de humedales artificiales para el tratamiento de aguas residuales
(Universidad Nacional (Costa Rica), 2013)En Costa Rica, las aguas negras generalmente son depositadas en tanques sépticos en donde se dan procesos de sedimentación y el efluente se infiltra en el subsuelo. Esta actividad representa un gran riesgo para ... -
Evaluación del impacto ambiental en una industria gráfica, que utiliza impresión litográfica tipo “offset”
(Universidad Nacional (Costa Rica), 2021-01-31)La industria gráfica se dedica a la impresión de documentos, que utilizan diferentes tecnologías, una de estas es la impresión litográfica tipo “offset”. El proceso productivo de este tipo de industria, así como el uso de ... -
Evaluación estadística de los niveles de mercurio detectados en peces de pico, en Costa Rica, en el periodo 2003-2013
(Universidad Nacional (Costa Rica), 2016-07-31)Los peces de pico, como el marlín, el pez vela y el pez espada, son depredadores pelágicos superiores de la cadena alimenticia; los especímenes de gran tamaño contienen en sus tejidos niveles ... -
Evaluación farmacológica y química de Stachytarpheta jamaicensis (Verbenaceae)
(Universidad de Costa Rica, 1996)Afier intraperitoneal administration of gradual aqueous doses obtained from Stachytarpheta jamaicensis leaves, the following effects were observed in rats: a reduction of motor activity and the alarm reaction, ataxia, ... -
Evaluación Físico-Química de los Sedimentos en el Estero Tamarindo y sus tribuatrios, Guanacaste, Costa Rica
(Universidad Nacional (Costa Rica), 2012)Se evaluaron los sedimentos del estero Tamarindo y de los ríos que confluyen en él con el propósito de determinar el efecto de las actividades antropogénicas de las comunidades aledañas. Los parámetros escogidos ... -
Evaluación química y biológica del efecto de extractos de plantas contra Plasmodium berghei
(Universidad de Costa Rica, 1996)Extracts from thirteen species of plants were evaluated by "in vivo" antimalarial test against Plasmodium berghei effects. Significant activities were observed in the ethyl acetate and aqueous extracts, elaborated of ... -
Evaluating watershed health in Costa Rican national parks and protected areas
(Springer Science and Business Media Deutschland GmbH, 2020-08-11)Although the biodiversity of Costa Rican national parks, forests, and wetlands has been extensively surveyed, there has not been a watershed assessment that refects their baseline water quality. Undoubtedly, the infux of ... -
Evolution of the Main Crater, Irazú Volcano National Park, Costa Rica – Consumer Drones in professional research
(Advanced UAV, 2022)There has been significant cracking and erosion on the south crater wall of the Main Crater below the area where tourists gather to view the main feature of the park; The Main Crater. By deploying the EVO Lite+ drone system ... -
Exploration of Bioengineered Scaffolds Composed of Thermo-Responsive Polymers for Drug Delivery in Wound Healing
(MDPI AG, 2021-01-30)Innate and adaptive immune responses lead to wound healing by regulating a complex series of events promoting cellular cross-talk. An inflammatory response is presented with its characteristic clinical symptoms: heat, pain, ... -
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 ... -
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 ...