Browsing Escuela de Química by Title
Now showing items 316-335 of 476
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Insight into the stable isotopic composition of glacial lakes in a tropical alpine ecosystem: Chirripó, Costa Rica
(Wiley & Sons, 2018)Tropical high‐elevation lakes are considered sentinels of global climate change. This work characterizes the hydrological conditions of tropical alpine glacial lakes located in the highlands of Chirripó, Costa Rica, using ... -
Inventario de emisiones de mercurio en Costa Rica en el 2014 utilizando la herramienta del PNUMA en un nivel N2
(Universidad Nacional (Costa Rica), 2018)El Convenio de Minamata se firmó en octubre del 2013 buscando proteger la salud humana y el medio ambiente de las liberaciones y emisiones antropogénicas tanto de mercurio elemental como de los compuestos que contienen ... -
Inventario de gases de efecto de invernadero debidos al sector desechos, en el cantón de San Pablo de Heredia
(Universida Nacional, 2021-06-21)Se presenta en este informe la estimación de los gases de efecto invernadero (GEI) generados por la categoría de inventario correspondiente a residuos sólidos, en el Cantón de San Pablo de Heredia, para el año 2018. En el ... -
Inventario nacional de las emisiones antropogénicas de mercurio, utilizando la metodología propuesta por el PNUMA, para el establecimiento de políticas nacionales e internacionales relacionadas con el control de las emisiones, Costa Rica, 2008
(Universidad Nacional (Costa Rica), 2015-02)Se realizó un Inventario Nacional de las Emisiones de Mercurio para Costa Rica en el 2008 utilizando el Nivel 1 de dicha herramienta. La metodología se desarrolló en 3 etapas en la que primero se efectuó la búsqueda de la ... -
Inventario preliminar de emisiones atmosféricas (SO2, NOx y PTS) de diferentes sectores industriales en Costa Rica
(Universidad Nacional (Costa Rica), 2021-01-31)El uso de diversos combustibles, el incremento de la urbanización, y el desarrollo económico, han influido en la generación de contaminantes atmosféricos, tales como los NOx (óxidos de nitrógeno), el SO2 (dióxido de azufre) ... -
Investigating the impacts of biochar on water fluxes in 2 tropical agriculture using stable isotopes
(European Geosciences Union, 2020)Amending soils with biochar, a pyrolyzed organic material, is an emerging practice to potentially increase plant available water. However, it is not clear (1) to what extent biochar amendments increase soil water storage ... -
Irbesartan desmotropes: Solid-state characterization, thermodynamic study and dissolution properties
(Xi'an Jiaotong University, 2019-07-10)Irbesartan (IBS) is a tetrazole derivative and antihypertensive drug that has two interconvertible structures, 1H- and 2H-tautomers. The difference between them lies in the protonation of the tetrazole ring. In the ... -
Iridoids from the aerial parts of Verbena littoralis (Verbenaceae)
(Elsevier, 2004)The iridoids, 6S-hydroxy-8S-methyl-4-methylene-hexahydro-cyclopenta[c]pyran-3-one and 6S,9S-dihydroxy-8S-methyl-4- methylene-hexahydro-cyclopenta[c]pyran-3-one, were isolated from the aerial parts of Verbena littoralis. ... -
Isolation and Characterization of Nanocellulose Obtained from Industrial Crop Waste Resources by Using Mild Acid Hydrolysis
(Tech Science Press, 2018)Cellulose, microcrystalline cellulose and nanocellulose were prepared from three agricultural waste resources: pineapple leaf (PALF), banana rachis (BR), and sugarcane bagasse (SCB). Each waste resource was first converted ... -
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 ...