Browsing Química by Title
Now showing items 114-133 of 156
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Rapid shift in microbial community structure in a neutral hydrothermal hot spring from Costa Rica
(2020)In this work, we characterize the geochemistry and microbial community of Bajo las Peñas, a neutral (pH 6.5-7.4), hot spring (T = 62.0-68.0°C) located near Turrialba Volcano, Costa Rica. The microbiota at its two sources ... -
Reactivity and structure of derivatives of 2-hydroxy-1,4-naphthoquinone (lawsone)
(2007-11)The structures of two derivatives of 2-hydroxy-1,4-naphthoquinone (lawsone) are examined using the density functional theory (DFT) hybrid functional B3LYP. Using the optimized structure of lawsone acetate, the reactivity ... -
Removal of both N-nitrosodimethylamine and trihalomethanes precursors in a single treatment using ion exchange resins
(2017-11-01)Drinking water utilities are relying more than ever on water sources impacted by wastewater effluents. Disinfection/oxidation of these waters during water treatment may lead to the formation of several disinfection ... -
Removal of N-nitrosodimethylamine precursors with powdered activated carbon adsorption
(2016-01-01)The main objective of this study was to examine the roles of powdered activated carbon (PAC) characteristics (i.e., surface chemistry, pore size distribution, and surface area) in the removal of N-nitrosodimethylamine ... -
Reproducible molecular networking of untargeted mass spectrometry data using GNPS
(2020-05-13)Global Natural Product Social Molecular Networking (GNPS) is an interactive online small molecule–focused tandem mass spectrometry (MS2) data curation and analysis infrastructure. It is intended to provide as much chemical ... -
Richness and metallo-tolerance of cultivable fungi recovered from three high altitude glaciers from Citlaltépetl and Iztaccíhuatl volcanoes (Mexico)
(2020)In Mexico little is known about high-altitude glacial psychrotolerant or psychrophilic fungal species, with most glacial fungi isolated from polar environments or Alpine glaciers. It has been documented that some of these ... -
Room temperature gas-solid reaction of titanium on glass surfaces forming a very low resistivity layer
(2016-09)Titanium films were deposited on quartz, glass, polyamide and PET substrates in a high vacuum system at room temperature and their electrical resistance monitored in vacuo as a function of thickness. These measurements ... -
Sex pheromone components of Diatraea considerata (Heinrich) (Lep., Pyralidae)
(1998-08)Three aldehydes. (Z)-11-hexadecenal (Z11–16:Ald), (Z)-7-hexadecenal (Z7–16:Ald) and (Z)-13-octadecenal (Z13–18:Ald), in a ratio of 74:23:3 are female-produced sex pheromone components of the pyralid moth, Diatraea considerata ... -
Short communication: Effect of different kefir grains on the attributes of kefir produced with milk from Costa Rica
(2020)Kefir is an artisanal product that is gaining scientific attention due to its increase in consumption attributed to its potential health benefits. The effect on the quality attributes of kefir grains of different origin ... -
Síntesis y evaluación de complejos de cobre (I/II) con ligandos polipiridínicos como mediadores redox en celdas solares sensibilizadas con tintes
(2020)En las celdas solares sensibilizadas con tintes (DSSCs), el mediador redox en el electrolito permite la transferencia de cargas al regenerar las moléculas del tinte durante su operación. Se sintetizaron y caracterizaron ... -
Structural and functional role of anions in electrochemical water oxidation probed by arsenate incorporation into cobalt-oxide materials
(2019)Direct (photo)electrochemical production of non-fossil fuels from water and CO2 requires water-oxidation catalysis at near-neutral pH in the presence of appropriate anions that serve as proton acceptors. We investigate the ... -
Structure, chirality, and field testing of a male-produced aggregation pheromone of Asian palm weevilRhynchophorus bilineatus (Montr.) (Coleoptera: Curculionidae)
(1995-10)4-Methyl-5-nonanol is a male-produced aggregation pheromone of the Asian palm weevil,Rhynchophorus bilineatus (Montr.). The pheromone was identified by coupled gas chromatographic-electroantennographic detection (GC-EAD) ...