Browsing Artículos científicos by Title
Now showing items 10-29 of 229
-
An in vivo model to study the anti-malaric capacity of plant extracts
(Universidad de Costa Rica, 1998)An in vivo model to study the antimalaric effect of plant extracts is described. White mice (25-30g body weight) are treated subcutaneously with 0.6ml of the diluted extract starting seven days before P. berghei infection; ... -
Analysis of Benzene Exposure Levels on Commuters Traveling within the Metropolitan Area of Costa Rica
(Scientific Research Publishing (China), 2015)This study reports the benzene exposure levels of commuters traveling within the metropolitan area of Costa Rica using personal cars, buses, and urban trains. 47 in-vehicle samples were collected in the 2014 wet season ... -
Analysis of energy transfer and ternary non-covalent filler/matrix/UV stabilizer interactions in carbon nanofiber and oxidized carbon nanofiber filled poly(methyl methacrylate) composites
(Elsevier, 2011-10-27)Ternary non-covalent interactions between carbon nanofibers (CNFs), oxidized carbon nanofibers (ox- CNFs), poly(methyl methacrylate) (PMMA) chains, and benzotriazole-containing UV stabilizers were analyzed using ... -
Analysis of non-covalent interactions between the nanoparticulate fillers and the matrix polymer as applied to shape memory performance
(The Royal Society of Chemistry, 2010)Non-covalent interactions between filler particles and polyurethanes were investigated using fluorescence emission spectroscopy. The results were used in the analysis of shape memory (SM) performance of polyurethanes. ... -
Análisis de las Olimpiadas Nacionales de Química en Costa Rica: Alcances y retos para la población joven
(Universidad Nacional (Costa Rica), 2012)La Escuela de Química ha promovido programas y proyectos académicos como las Olimpiadas de Química que estimulen y mejoren el aprendiza-je de esta ciencia. Como competencia se identifican estudiantes de alto desempeño ... -
Análisis de los accidentes químico-tecnológicos presentados en la gran área metropolitana durante el período de 1998-2005
(Universidad Nacional (Costa Rica), 2010)Durante el periodo 1998-2005, la unidad de Materiales Peligrosos del Instituto Nacional de Seguros (MATPEL) atendió 329 emergencias químico-tecnológicas en Costa Rica, de las cuales 255 ocurrieron en la Gran Área Metropolitana ... -
Announcing the call for the Issue Focus on the 2nd Costa Rican Biophysics Symposium—virtual meeting, March 2021
(Springer (Alemania), 2021)This Commentary is a call for submissions for the upcoming Issue Focus that will highlight some of the scientific topics discussed during the 2nd Costa Rica Biophysics Symposium. -
Anthrone and oxanthrone C,O-diglycosides from Picramnia teapensis
(Elsevier, 2000)Two C,O-diglycosylated compounds, the anthrone picramnioside F, and the oxanthrone mayoside C, were isolated from the stem bark of Picramnia teapensis, along with the previously reported anthraquinones, 1-O-b-d- and ... -
Antimicrobial activities of Marcgraviaceae species and isolation of a naphthoquinone from Marcgravia nervosa (Marcgraviaceae)
(NRC Research Press, 2015)The Marcgraviaceae is a neotropical plant family of lianas and shrubs distributed throughout Central and South America, mainly in evergreen and semi-evergreen tropical forests. In this study, extracts of 12 Marcgraviaceae ... -
Antimicrobial activity and physicochemical characterization of thermoplastic films based on bitter cassava starch, nanocellulose and rosemary essential oil
(SAGE Publications (Estados Unidos), 2022)Extended shelf-life of many foods is a modern requirement that has been achieved by means of fossil-based plastic films despite their environmental issues. Recently, starchbased, fully biodegradable thermoplastics are ... -
Antimicrobial Activity of Most Abundant Marine Macroalgae of the Caribbean Coast of Costa Rica
(Asian Economic and Social Society (AESS) (Estados Unidos), 2012)Marine ecosystems have a very large diversity of resources, most of them still partially unknown, and a few others exploited for development of new industrial and toxicological products. Seaweeds are directly exposed and ... -
Antioxidant and antimicrobial activity of two Costa Rican cultivars of ber (Ziziphus mauritiana): An underexploited crop in the American tropic
(Wiley Periodicals LLC, 2023-03-17)Ber is an antioxidant-rich fruit from Asia and has recently been cultured in Central America. The antioxidant capacity and antimicrobial activity of Z. mauritiana cultured of bers from Guanacaste, Costa Rica, were evaluated. ... -
Aplicación de un método para evaluar el impacto ambiental de proyectos de construcción de edificaciones universitarias
(2016)La evaluación de impacto ambiental consiste en la identificación y valoración de los impactos potenciales de proyectos respecto a los componentes físicos, químicos y biológicos, culturales, económicos y sociales, con el ... -
Aporte ambiental de la planta de tratamiento de aguas residuales Los Tajos en la remoción de contaminantes fisicoquímicos y microbiológicos
(Universidad Nacional, Costa Rica, 2022-01-31)The objective of the study was to analyze the environmental contribution, in terms of removal of physicochemical and microbiological pollutants, from the Los Tajos Wastewater Treatment Plant (WWTP) to the Torres River. ... -
Application of a Sulfur Removal Hydrometallurgical Process in a Lead-Acid Battery Recycling Plant in Costa Rica
(Scientific Research Publishing Inc., 2017)This study presents the implementation of a desulphurization process for lead recycling under different chemical and physical conditions using pyro-metallurgical processes. Desulphurization was done using a hydrometallurgical ... -
Aprovechamiento de la yuca amarga Manihot esculenta Crantz ) para la extracción de almidón y la producción de un material termoplástico (TPS)
(Universidad Nacional (Costa Rica), 2019)La versatilidad de los materiales poliméricos derivados de hidrocarburos fósiles ha beneficiado el desarrollo industrial, sin embargo, han ocasionado efectos adversos sobre el medio ambiente. Para minimizar estas consecuencias ... -
Arsenate removal by chitosan iron oxyhydroxide beads: Preparation, characterization, and adsorption studies
(Desalination Publications, 2021)This study compared arsenic removal from drinking water by two different adsorbents: iron-im-pregnated chitosan beads (Fe-ICB) and iron-doped chitosan beads (Fe-dCB). Scanning electron microscopy, X-ray diffraction (XRD), ... -
Arthropod biodiversity loss and the transformation of a tropical agro-ecosystem
(Chapman & Hall, 1997)The coffee (coffea arabica) agro-ecosystem in the Central Valley of Costa Rica was formerly characterized by a high vegetational diversity. This complex system has been undergoing a major transformation to capital-intensive ... -
Aspectos del contexto socioambiental que inciden en la contaminación del recurso hídrico en un cantón urbano
(Universidad Nacional (Costa Rica), 2021-07-01)El objetivo fue identificar y analizar los aspectos más relevantes del contexto socioambiental de un cantón urbano, que inciden en la contaminación del recurso hídrico. Se realizó una investigación descriptiva con un ... -
Ácido l-poliláctico (Pla) y nanotubos de carbono de pared múltiple (ntcpm) con potenciales aplicaciones industriales
(Universidad Nacional de Colombia, 2021)En términos generales, es bien conocida la cualidad que poseen algunos polímeros de cambiar sus propiedades físicas y químicas finales mediante la adición de nanopartículas a la matriz polimérica para producir un ...