Browsing Artículos científicos by Title
Now showing items 212-231 of 237
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Síntesis y caracterización de nanosílices funcionalizadas injertadas con 3-aminopropil trietoxisilano para ser utilizadas en adhesivos de poliuretano
(Universidad del País Vasco (España), 2007-03)En este trabajo se presentan los resultados obtenidos al modificar superficialmente una sílice pirogénica hidrófila comercial, con una superficie específica de 200 m2/g, a la que se le injertó 3-aminopropiltrietoxisilano. ... -
Síntesis, propiedades y aplicaciones de puntos cuánticos a base de carbono
(Revistes Catalanes amb Accés Obert, 2022)Los puntos cuánticos a base de carbono muestran propiedades ópticas y electrónicas de interés tecno-lógico debido a su confinamiento cuántico y el efecto de los grupos funcionales en sus bordes. Pueden ... -
Spatial and Temporal Variation of Stable Isotopes in Precipitation across Costa Rica: An Analysis of Historic GNIP Records
(2013-11-27)The location of Costa Rica on the Central American Isthmus creates unique microclimate systems that receive moisture inputs directly from the Caribbean Sea and the Pacific Ocean. In Costa Rica, stable isotope monitoring ... -
Stable isotopes reveal groundwater to river connectivity in a mesoscale subtropical watershed
(Taylor and Francis Ltd., 2021)The Corumbataí River basin (São Paulo, Brazil) has a critical situation regarding water availability due to the intensive use to support agriculture and urbanization, requiring scientific information to face water demand. ... -
Stable isotopic characterizacion of nitrate wet deposition in the tropical urban atmosphere of Costa Rica
(Springer, 2021-07-13)Increasing energy consumption and food production worldwide results in anthropogenic emissions of reactive nitrogen into the atmosphere. To date, however, little information is available on tropical urban environments where ... -
Structure and Properties of Biodegradable Polymers: Rolling Effect in Poly (butylene succinate) Sheets
(SAGE Publishing (Estados Unidos), 2004)Sheets made from poly (butylene succinate) (PBS) were prepared by extrusion. They have been studied under uniaxial drawing as a function of the draw condition. Changes in molecular orientation and crystallinity were ... -
Student Camps to Promote Scientific Vocations in STEM: The Quimi Camp Case
(Universidad Nacional (Costa Rica), 2023-06-01)[Objetivo] Desde el año 1988 y hasta el año 2018, el estudiantado de secundaria en Costa Rica debía aprobar un examen final para graduarse de la escuela secundaria, y ser elegible para una educación universitaria pública. ... -
Synthesis of Dihydroindolo[2,3-c]carbazole as Potential Telomerase Inhibitor
(Journal of Heterocyclic Chemistry vol.53 no.3 762-766 2015, 2015-05-27)The dictyodendrins A-E were the first marine natural products that show inhibition of telomerase. A versatile and convergent route was described for the synthesis of derivatives of these pyrrolo[2,3-c]carbazole alkaloids ... -
The effect of solution environment and the electrostatic factor on the crystallisation of desmotropes of irbesartan
(Royal Society of Chemistry, 2019)The experimental conditions necessary for stabilising irbesartan (IBS) tautomers in solution and selectively obtaining the desmotropic crystal forms are presented herein. 1H and 2H tautomers were stabilized in specific ... -
The manufacture and properties of oil palm and pineapple leaf fiberboard panels
(WIT Transactions on Ecology and the Environment, 2014)Particleboards were manufactured from oil palm fruit, the oil palm mesocarp fiber of Elaeis guineensis, the leaves of pineapple (Ananas comosus) and the sawdust from three fast-growing species of trees (Gmelina arborea, ... -
Tracing water sources and fluxes in a dynamic tropical environment from observations to modeling
(Frontiers in Earth Science, 2020-11-06)Tropical regions cover approximately 36% of the Earth’s landmass. These regions are home to 40% of the world’s population, which is projected to increase to over 50% by 2030 under a remarkable climate variability scenario ... -
Tracking the water fingerprints of Cocos Island: A stable isotope analysis of precipitation, surface water, and groundwater
(Revista de Biología Tropical, 2016)The use of stable isotopes of water, both δ2H and δ18O has provided novel insights in hydrological studies, ecological applications, understanding climate variability, and reconstructing paleoclimate. However, information ... -
Tratamiento de aguas residuales con tecnologías alternativas en una pequeña unidad doméstica–productiva
(Universidad Nacional (Costa Rica), 2013)Se evaluó el sistema de tratamiento de aguas residuales instalado en una pequeña unidad doméstica-productiva ubicada en la zona de Escazú de la provincia de San José, mediante la medición de la demanda bioquímica de ... -
Using Sniffer4D and SnifferV portable gas detectors for UAS monitoring of degassing at the Turrialba Volcano Costa Rica
(Advanced UAV, 2023)Since the completion of the first Sniffer UAS payload research article titled; Using UAS with Sniffer4D Payload to Document Volcanic Gas Emissions for Volcanic Surveillance: In this study the UAS system deployed carried ... -
Using UAS for monitoring the summit of the Arenal Volcano Costa Rica
(Mersin Üniversitesi (Turquía), 2023)The Arenal summit is seldom studied for several reasons. First, the eruptive activity has stopped since October 2010, second the active summit crater C is difficult to reach due to an intense steep climb through the tropical ... -
Using UAS with Sniffer4D payload to document volcanic gas emissions for volcanic surveillance
(Advanced UAV, 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 manage this responsibility. The ... -
Uso de nanomateriales en polímeros para la obtención de bioempaques en aplicaciones alimentarias
(Sociedad Química del Perú (Perú), 2011)La mayor parte de los materiales que se utilizan para el empaque de alimentos no son biodegradables. Con el fin de desarrollar materiales ecológicos se ha investigado distintos biopolímeros que se han limitado debido a ... -
Uso de plaguicidas en cultivos agrícolas como herramienta para el monitoreo de peligros en salud
(Universidad Nacional (Costa Rica), 2013)Costa Rica ha incrementado el uso de plaguicidas de mayor toxicidad, debido entre otras cosas al desarrollo de plagas más resistentes y la necesidad que tienen algunos productos agrícolas de exportación de mantener ... -
Utilización de la biomasa residual del cultivo de la piña (Ananas Comosus) para la desproteinización enzimática de desechos de la actividad camaronera
(Universidad Nacional (Costa Rica), 2013)Se realizó un estudio para comprobar la capacidad desproteinizante de extractos proteicos obtenidos a partir de desechos de rastrojo de piña a diferentes concentraciones sobre los sub-productos de la ... -
Validación de métodos rápidos de análisis para aguas dulces superficiales
(Universidad Nacional (Costa Rica), 2016)La Universidad Nacional, por intermedio del Laboratorio de Manejo del Recurso Hídrico (LAMRHI), realiza proyectos de investigación-extensión en los cuales se caracterizan físico química y biológicamente las aguas ...