Browsing Artículos científicos by Title
Now showing items 110-129 of 243
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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, ... -
Exploring Dissolved Organic Carbon Variations in a High Elevation Tropical Peatland Ecosystem: Cerro de la Muerte, Costa Rica
(Frontiers Media (Suiza), 2022-01)Tropical peatlands are distributed mainly in coastal lowlands; however high elevation regions exhibit a large prevalence of small and fragmented peatlands that are mostly understudied. Artificial drainage of peatlands to ... -
Exploring the acid neutralizing effect in rainwater collected at a tropical urban area: Central Valley, Costa Rica
(Elsevier (Países Bajos), 2023)We report on the chemical and the carbon isotopic composition of dissolved inorganic carbon (DIC) of rainwater collected between May and October 2020 in the Central Valley, Costa Rica. Precipitation samples were ... -
Extracción y evaluación de taninos condensados a partir de la corteza de once especies maderables de Costa Rica
(Tecnológico de Costa Rica (Costa Rica), 2012)La naturaleza química de los taninos condensados los convierte en una fuente natural de compuestos orgánicos, con una aplicación potencialmente amplia para usos medicinales e industriales. La extracción y análisis de ... -
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 ...