Química
Envíos recientes
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Polifenoides de Uncaria Tormentosa y propiedades fitoterapéuticas de uña de gato costarricense
(2012-12-18)Esta invención se refiere a extractos fenólicos conteniendo procianidinas, propelargonidinas y flavanolignanos, con propiedades/actividades potencialmente beneficiosas para la salud humana, y obtenidos a partir de las ... -
Estudio de aditivos anticorrosivos para las aleaciones comerciales de la batería alcalina alumino-aire
(2020)La sociedad actual está avanzando hacia un modelo energético más responsable y sostenible. La punta de lanza de esta necesaria tendencia es el uso de fuentes de energía renovables y la reducción de las emisiones de CO2 ... -
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 ... -
Tetraaquabis(2,3-dihydro-1,4-benzodioxine-2-carboxylato)calcium(II)
(2020)The acid–base reaction of 1,4-benzodioxane 2-carboxylic acid with calcium carbonate furnished the centrosymmetric title compound, [Ca(C9H7O4)2(H2O)4], in which the metal ion is octahedrally coordinated by two monodentate ... -
Bis(μ2-benzoato-κ2O,O′)bis(benzoato-κO)bis(ethanol-κO)bis(μ3-hydroxido)hexakis(μ-pyrazolato-κ2N,N′)hexacopper(II) ethanol disolvate
(2019)Trinuclear copper–pyrazolate entities are present in various Cu-based enzymes and nanojar supramolecular arrangements. The reaction of copper(II) chloride with pyrazole (pzH) and sodium benzoate (benzNa) assisted by ... -
1,3-Bis{[(2,6-dimethylphenyl)sulfanyl]methyl}benzene
(2019)The structure of the title compound, C24H26S2, an example of a pincer ligand with an SCS-chelation motif, illustrates the steric effects of the methyl groups in the thiophenyl rings at the 2- and 6-positions, forcing a ... -
Crystal structures and biological activity of 1,1,4-triphenyl-substituted 1,3-enyne compounds
(2019)1,3-Enyne structural motifs are versatile building blocks in organic synthesis and occur widely in various natural products with many of them being highly active as cytotoxic macrolides and antitumour antibiotics. This ... -
1-Nitro-4-(1-propyn-1-yl)benzene
(2019)The title compound, C9H7NO2, was prepared by alkynylation of 4-iodonitrobenzene with 1,3-dilithiopropyne in the presence of 1 equivalent of CuI and catalytic amounts of Pd(PPh3)2Cl2. The complete molecule is generated ... -
Co-adsorbing effect of bile acids containing bulky amide groups at 3β-position on the photovoltaic performance in dye-sensitized solar cells
(2019)Co-adsorbing molecules attain certain control in the surrounding of the dyes leading to enhanced efficiencies mainly by affecting the recombination of the photogenerated electrons and aggregation of dyes. Bile acids ... -
Calidad del Aire en la Sede Central Rodrigo Facio de la Universidad De Costa Rica
(2014-12)Este estudio vigiló la calidad del aire en la Sede Universitaria Rodrigo Facio de la Universidad de Costa Rica con el fin de mantener informadas a las autoridades universitarias, cantonales, del Ministerio de Ambiente y ... -
Aprovechamiento de los desechos de la industria del anodizado de aluminio en la síntesis de zeotipos tipo AlPO4-X y aplicación de estos en la captura de amoniaco
(2020)La finalidad de este trabajo fue llevar a cabo la síntesis de zeotipos tipo AlPO4-X utilizando desechos provenientes de la industria de anodizado de aluminio (DAAl-1) en sustitución de la fuente de aluminio, estos desechos ... -
Nickel-iron catalysts for electrochemical water oxidation – redox synergism investigated by in situ X-ray spectroscopy with millisecond time resolution
(2018)In future technological systems for chemical storage of renewable energy and production of non-fossil fuels, NiFe oxyhydroxides are prime candidates for efficient alkaline water oxidation (oxygen evolution reaction, OER). ... -
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 ... -
Heterogeneous Water Oxidation: Surface Activity versus Amorphization Activation in Cobalt Phosphate Catalysts
(2015)Is water oxidation catalyzed at the surface or within the bulk volume of solid oxide materials? This question is addressed for cobalt phosphate catalysts deposited on inert electrodes, namely crystallites of pakhomovskyite ... -
Influence of bitumen and aggregate polarity on interfacial adhesion
(2017)The quality of the bitumen–aggregate interface formed in an asphalt mixture is dictated by the physicochemical properties of both materials, such as surface polarity. In order to better understand the role of polarity on ... -
Superoxide dismutase based biosensor for the electrochemical determination of epinephrine
(2018)New amperometric biosensor for epinephrine was developed, using a screen printed carbon electrode with tetrathiafulvalene (5% v/w) incorporated into carbon ink (SPCTTFE). Electrodic surface was modified with nanoparticles ... -
Synthesis and characterization of new mixed-valent Mn(II)/Mn(III) and mixed metal Ni/Mn complexes
(2015)Microwave assisted synthesis and bench-top reactions are compared for Mn and Mn/Ni reaction systems with substituted salicylic acid (2-hydroxy-6-isopropyl-3-methylbenzoic-acid (SALOH2). When Mn salts are used, the microwave ... -
Biosensor for Aluminum(III) Based on α-Chymotrypsin Inhibition using a Disposable Screen-Printed Carbon Electrode and Acetyl-Tyrosine Ethyl Ester as Substrate
(2015)We report on a new amperometric assay for Al(III) ions based on the inhibition of α-chymotrypsin enzyme. The immobilization of the enzyme was performed on screen-printed carbon electrodes modified with gold nanoparticles ... -
Bile salts and derivatives: Rigid unconventional amphiphiles as dispersants, carriers and superstructure building blocks
(2015)Steroidal surfactants like bile salts have a rigid amphiphilic structure significantly different from the typical head–tail one. As a result, these molecules show peculiar features in their self-assembly behavior and ...
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