Browsing Artículos científicos by Title
Now showing items 155-174 of 243
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Isolation and Characterization of Nanofibrillar Cellulose from Agave tequilana Weber Bagasse
(Hindawi Limited, 2019)The bagasse of Agave tequilana Weber is one of the most abundant agroindustrial wastes in the state of Jalisco. However, at the present time, there is no technical use for this waste, and its high availability makes it ... -
Isomerization of fatty acids: A cellular barrier mechanism in nanotechnology?
(Journal of Nanoscience and Nanotechnology Vol.17 1-9, 2017-01)This work is a kinetic study of the coupling reaction of 2-mercaptoethanol with methyl undecenoate and with methyl oleate through " click " chemistry. Reversibility and reactivity of each system were followed through Fourier ... -
Isotope hydrology and baseflow geochemistry in natural and human-altered watersheds in the Inland Pacific Northwest, USA
(2015-02-18)This study presents a stable isotope hydrology and geochemical analysis in the inland Pacific Northwest (PNW) of the USA. Isotope ratios were used to estimate mean transit times (MTTs) in natural and human-altered watersheds ... -
Isotope hydrology of a tropical coffee agroforestry watershed: Seasonal and event-based analyses
(Wiley & Sons, 2018)Stable isotope variations are extremely useful for flow partitioning within the hydrologic cycle but remain poorly understood throughout the tropics, particularly in watersheds with rapidly infiltrating soils, such as ... -
Isotopic composition and major ion concentrations of national and international bottled waters in Costa Rica
(Elsevier (Países Bajos), 2021)Global bottled water consumption has largely increased (14.35 billion gallons in 2020) [1], [2], [3], [4], [5] during the last decade since consumers are demanding healthier and safer forms of rehydration. Bottled water ... -
Isotopic composition in precipitation and groundwater in the northern mountainous region of the Central Valley of Costa Rica
(Taylor & Francis, 2016)The linkage between precipitation and recharge is still poorlyunderstood in the Central America region. This study focuses onstable isotopic composition in precipitation and groundwater in the northern mountainous region ... -
Isotopic variability (δ18O, δ2 H and d-excess) during rainfall events of the north American monsoon across the Sonora River Basin, Mexico
(Elsevier Ltd, 2021)The economic activities of the Sonora strongly depend on groundwater extraction, which is generally of recent meteoric origin. Understanding the hydrological functioning in this semi-arid region, located in northwestern Mexico, ... -
Key drivers controlling stable isotope variations in daily precipitation of Costa Rica: Caribbean Sea versus Eastern Pacific Ocean moisture sources
(Elsevier, 2016)Costa Rica is located on the Central American Isthmus, which receives moisture inputs directly from the Caribbean Sea and the Eastern Pacific Ocean. This location includes unique mountainous and lowland microclimates, but ... -
Key hydrological processes in the Del Azul Creek basin, sub-humid Pampean Plain
(Elsevier B.V., 2021-02)Groundwater plays an important role in the economic development of the Chaco-Pampean Plain (Argentina), where industry, agriculture and cattle farming are the main economic activities. The 66% of the country's population ... -
Kinetics of anaerobic degradation of screened dairy manure by upflow fixed bed digesters: Effect of natural zeolite addition
(Taylor & Francis, 2009)The effect of the hydraulic retention time (HRT) on the performance of two up-flow anaerobic fixed bed digesters (UFAFBDs) packed with waste tire rubber (D1) and waste tire rubber and zeolite (D2) as micro-organism ... -
Kinetics of Isothermal Degradation Studies in Adhesives by Thermogra vimetric Data: Effect of Hydrophilic Nanosilica Fillers on the Thermal Properties of Thermoplastic Polyurethane-Silica Nanocomposites
(Recent Patents on Nanotechnology, 2008)The kinetics of thermal degradation process on thermoplastic polyurethanes (TPUs) adhesives with hydrophilic nanosilicas was studied using isothermal thermogravimetric analysis within the temperature range from 360 °C ... -
Launching the SnifferV and Sniffer4D multigas detectors into the active crater of the Poás Volcano in Costa Rica using unmanned aerial systems
(Mersin Üniversitesi (Turquía), 2023)There are two Sniffer4D V2 devices we have been deploying in the field for scientific research with the Laboratory of Atmospheric Chemistry. We have successfully tested for volcanic emissions at the Turrialba volcano, Irazú ... -
Lead acid battery recycling in Costa Rica: A case study
(WIT Transactions on Ecology and the Environment, 2012)This work describes the production of secondary lead in a smelter located in Costa Rica. The only input of the plant is scrap automotive batteries. We describe the environmental management strategies used for waste ... -
Manejo de Mercancías Químicas peligrosas en puerto Caldera, Puntarenas, Costa Rica
(Universidad Nacional (Costa Rica), 2009)Puerto Caldera, ubicado en Puntarenas, Costa Rica, en uno de los puertos más importantes de Centroamérica, ya que a través de él se trasiegan por año aproximadamente 1.5 millones de toneladas métricas de carga de diferentes ... -
Materiales poliméricos compuestos obtenidos a partir de los residuos generados por la agroindustria de la caña de azúcar. Una alternativa adicional. II
(Universidad del País Vasco (España), 2008)En trabajos previos, en los que se ha utilizado residuos generados por la agroindustrialización de la caña de azúcar, se determinó que la utilización de un 70 % de melaza de caña de azúcar como sustituyente parcial del ... -
Maxonine, a novel alkaloid from Simira maxonii
(Elsevier, 1989)A novel alkaloid, maxonine, with an indole-pyrido-naphthyridine skeleton, has been isolated from . Its structure was elucidated on the basis of 2D NMR spectral data. A novel alkaloid, maxonine (1), with an indolepyrido-n ... -
Medicinal Water? The occurrence and fate of pharmaceuticals in aquatic environments A short communication
(Universidad Nacional (Costa Rica), 2012)Although very little is known about the transport, fate and toxic effects of medical compounds in aquatic environments, the presence of these compounds in potable water sources can no longer be overlooked. We can ... -
Mediciones y el modelaje de la concentración del dióxido de azufre y de la composición del agua de lluvia en los alrededores del Volcán Poás durante el 2017 en Costa Rica
(Corporación Gestión de Riesgos y Desastres GRID-Chile (Chile), 2024-01)Debido al aumento de la actividad del Volcán Poás en 2017, en Costa Rica, se realizaron muestreos en los alrededores del cráter activo para cuantificar la concentración de dióxido de azufre (SO2) y las características ... -
Methane Dynamics in a Tropical Serpentinizing Environment: The Santa Elena Ophiolite, Costa Rica
(Universidad Nacional (Costa Rica), 2017)Uplifted ultramafic rocks represent an important vector for the transfer of carbon and reducing power from the deep subsurface into the biosphere and potentially support microbial life through serpentinization. This ... -
Minimum requirements for publishing hydrogen, carbon, nitrogen, oxygen and sulfur stable-isotope delta results (IUPAC Technical Report)
(De Gruyter (Alemania), 2022)Stable hydrogen, carbon, nitrogen, oxygen and sulfur (HCNOS) isotope compositions expressed as isotope-delta values are typically reported relative to international standards such as Vienna Standard Mean Ocean Water ...