Browsing Química by Title
Now showing items 87-106 of 123
-
Pheromone chirality of african palm weevil, Rhynchophorus phoenicis (F.) and palmetto weevil, Rhynthophorus crueniatus (F.) (Coleoptera: Curculionidae)
(1994-09)There are four stereoisomers of both 3-methyl-octan-4-ol, the aggregation pheromone of the African palm weevil,Rhynchophorus phoenicis (F.) and 5-methyl-octan-4-ol, the aggregation pheromone of the palmetto weevil,Rhynchophorus ... -
Pheromone chirality of asian palm weevils,Rhynchophorus ferrugineus (Oliv.) andR. vulneratus (Panz.) (Coleoptera: Curculionidae)
(1996-02)Production of 4-methyl-5-nonanol, and 4-methyl-5-nonanone by two sympatric Asian palm weevils,Rhynchophorus ferrugineus (Oliv.) andR. vulneratus (Panz.) suggested that enantiospecificity of either compound could impart ... -
Pristine but metal-rich Río Sucio (Dirty River) is dominated by Gallionella and other iron-sulfur oxidizing microbes
(2017-03)Whether the extreme conditions of acidity and heavy metal pollution of streams and rivers originating in pyritic formations are caused primarily by mining activities or by natural activities of metal-oxidizing microbes ... -
Producción de un detergente líquido ambientalmente preferible y estrategia de lanzamiento al mercado del Valle Central Occidental de Costa Rica
(2009)Se determinó la viabilidad de instalar una empresa de productos químicos preferibles para el ambiente, en el cantón de Poás de Alajuela, Costa Rica. Con este propósito se seleccionó una formulación de un detergente líquido ... -
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 ... -
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 ... -
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) ... -
Sudoku Puzzles for First-Year Organic Chemistry Students
(2007-04)We use sudoku puzzles to help the students (i) learn the correspondence between the names of the amino acids, their abbreviations, and codes and (ii) learn the correspondence between the names of the functional groups, ...