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Mostrando ítems 11-20 de 266
Aggregation Pheromones and Host Kairomones of West Indian Sugarcane Weevil, Metamasius hemipterus sericeus
(1997)
Coupled gas chromatographic–electroantennographic detection (GC-EAD) analyses and coupled GC-mass spectrometry (MS) of volatiles produced by male and female West Indian sugarcane weevils (WISW), Metamasius hemipterus ...
Evaluación de la capacidad del cemento Portland dopado con nanopartículas de TIO2 para la disminución de Pseudomonas aeruginosa y Escherichia coli en agua
(2022-10)
El abastecimiento de agua potable no es equitativo para la población mundial y este problema empeora debido al crecimiento poblacional, a la contaminación, al calentamiento global y a un inadecuado tratamiento de potabilización. ...
From Ideality to Simplicity: A Robust and Affordable Hydrogen Reference Electrode
(2020-02-01)
In electrochemistry, the concept of a reference electrode is fundamental. Introductory courses might mention the standard hydrogen electrode (SHE), its working principle, and its theoretical design; however, chances are ...
Screening of Latin American Plants for Cytotoxic Activity
(2006)
The SRB cytotoxicity assay was used to screen plant extracts, in a collaborative multinational OAS project involving Argentina, Bolivia, Colombia, Costa Rica, Guatemala, Nicaragua and Panama, against breast (MCF-7), lung ...
Optimization of semiochemical-based trapping of Metamasius hemipterus sericeus (Olivier) (Coleoptera: Curculionidae)
(1996-08)
Response of adults of the West Indian sugarcane weevil,Metamasius hemipterus sericeus, to various semiochemical treatments and physical trap designs was studied in southern Florida in field-grown banana and Canary Island ...
A facile method for the preparation of bishomopropargylic alcohols from acyl chlorides
(2014)
Controlled dilithiation of propargyl bromide with two equivalents of n-butyllithium, in the presence of
TMEDA, produces the operational equivalent of the dianion 1,3-dilithiopropyne. The latter reacts
efficiently with ...
Propargylation of Alkyl Halides: (E)-6,10-dimethyl-5,9-undecadien-1-yne and (E)-7,11-dimethyl-6,10-dodecadien-2-yn-1-ol
(1990)
El siguiente documento es parte de un experimento científico que se titula “Propargylation of Alkyl Halides: (E)-6,10-dimethyl-5,9-undecadien-1-yne and (E)-7,11-dimethyl-6,10-dodecadien-2-yn-1-ol”. El mismo fue realizado ...
Fungi with history: Unveiling the mycobiota of historic documents of Costa Rica
(2022-06-12)
Through nondestructive techniques, we studied the physicochemical characteristics and mycobiota of five key historic documents from Costa Rica, including the Independence Act of Costa Rica from 1821. We determined that for ...
Residuos, sorción y desorción del herbicida paraquat en suelos tropicales
(1987-11-24)
Se analizaron por espectrofotometría residuos del herbicida Paraquat en muestras de suelos tropicales de Costa Rica dedicados al cultivo del café y donde el Paraquat es aplicado desde hace alrededor de 20 años, una o dos ...
Neutral organic redox pairs based on sterically hindered hydroquinone/benzoquinone derivatives for dye-sensitized solar cells
(2018-06)
Substituted derivatives of hydroquinone/benzoquinone were studied as organic redox mediators in the electrolyte for dye-sensitized solar cells (DSSCs). Thus, di-tert-butylhydroquinone (DTHQ), thymohydroquinone (ThymHQ) and ...