Acetaldehyde
Mostrando 13-24 de 303 artigos, teses e dissertações.
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13. Effects of CO2 pretreatment on the volatile compounds of dried Chinese jujube (Zizyphus jujuba Miller)
Abstract The aim of this study was to investigate whether anaerobic metabolites could induce volatile compounds and improve aroma of dried jujube (Ziziphus jujuba Miller). Jujube fruits were incubated in a polyvinyl chloride bag containing 5% CO2 and 95% N2 for up to 168 h at 25 °C and 3 samples were randomly removed every 6 h and oven dried to a moisture c
Food Sci. Technol. Publicado em: 13/04/2017
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14. An original method for producing acetaldehyde and diacetyl by yeast fermentation
Abstract In this study a natural culture medium that mimics the synthetic yeast peptone glucose medium used for yeast fermentations was designed to screen and select yeasts capable of producing high levels of diacetyl and acetaldehyde. The presence of whey powder and sodium citrate in the medium along with manganese and magnesium sulfate enhanced both biomas
Braz. J. Microbiol.. Publicado em: 2016-12
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15. Emissions of Criteria and Non-Criteria Pollutants by a Flex-Fuel Motorcycle
While criteria pollutants have established emission limits for motorcycles in Brazil, aldehydes limits have not been established and conclusive studies have not been found in the existing literature, despite the growing number of motorcycles using flex fuel in Brazil. This work presents results for the emissions of criteria pollutants, such as carbon monoxid
J. Braz. Chem. Soc.. Publicado em: 2016-12
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16. VAPOR-PHASE CATALYTIC CONVERSION OF ETHANOL INTO 1,3-BUTADIENE ON Cr-Ba/MCM-41 CATALYSTS
AbstractAl-MCM-41, 16%Ba/Al-MCM-41 and 1.4%Cr-16%Ba/Al-MCM-41 were used as catalysts in the vapor-phase catalytic conversion of ethanol. Physical-chemical properties of the catalysts and the effect of barium and chromium on the Al-MCM-41 activity and 1,3-butadiene yield were studied. The catalysts were characterized by X-ray diffraction (XRD), N2 physisorpti
Braz. J. Chem. Eng.. Publicado em: 2015-06
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17. Relationship between acetaldehyde concentration in mouth air and tongue coating volume
Objective Acetaldehyde is the first metabolite of ethanol and is produced in the epithelium by mucosal ALDH, while higher levels are derived from microbial oxidation of ethanol by oral microflora such as Candida species. However, it is uncertain whether acetaldehyde concentration in human breath is related to oral condition or local production of acetaldehy
J. Appl. Oral Sci.. Publicado em: 2015-02
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18. Estudo da oxidação parcial do etanol em catalisadores de Rh por DRIFTS
The partial oxidation of ethanol on γ-Al2O3, CeO2, ZrO2 and Ce xZr1-xO2 supported rhodium catalysts was investigated by Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS). The catalysts were characterized by temperature-programmed reduction (TPR) and cyclohexane dehydrogenation. DRIFTS studies on the partial oxidation of ethanol showed tha
Quím. Nova. Publicado em: 2013
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19. Avaliação de polimorfismos em genes de metabolismo do etanol e gene de reparo do DNA em pacientes portadores de câncer de boca / Evaluation of polymorphisms in genes of ethanol metabolism and DNA repair gene in patients with oral cancer
O carcinoma epidermóide é uma neoplasia que pode ter origem do revestimento mucoso de vários sítios das vias aerodigestivas superiores, sendo a língua o sítio primário com maior incidência. Entre os fatores de risco para a doença estão a idade, as mutações genômicas, o hábito tabagista e principalmente o consumo de etanol. O etanol é considera
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 30/08/2012
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20. Análise multiparamétrica da qualidade dos frutos, mostos e vinhos de jabuticaba / Multiparametric analysis of quality of fruits, musts and wines jabuticaba
Chemical parameters were monitored during the jabuticabas development, fermentation and ageing of its wine, by quantitative 1H NMR, spectrophotometric assays and standard methods of analysis. Data collected were analysed by variance (ANOVA), principal components (PCA), hierarchical cluster (HCA) and canonical correlation analyses (CCA). Jabuticabas developme
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 28/06/2012
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21. Platinum and nioubium based catalysts for the anode of polymer electrolyte membrane fuel cells fed with low molecular weight alcohols / Catalisadores a base de platina e nióbio para o ânodo da célula a combustível de membrana trocadora de prótons alimentada com alcoóis de baixa massa molecular
In this work, the methanol and ethanol electrochemical oxidation reactions are studied on platinum (Pt) and niobium (Nb) catalysts supported on high surface area carbon. The selected materials were PtNb/C, Pt-Nb2O5(amorphous) /C e Pt-Nb2O5(crystalline) /C, using as reference for comparison purposes the commercial catalyst 20% Pt-C E-TEK. The catalysts were p
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 25/01/2012
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22. Synthesis, characterization and catalytic properties of nanocrystaline Y2O3-coated TiO2 in the ethanol dehydration reaction
In the present study, TiO2 nanopowder was partially coated with Y2O3 precursors generated by a sol-gel modified route. The system of nanocoated particles formed an ultra thin structure on the TiO2 surfaces. The modified nanoparticles were characterized by high resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD) analysis, Zeta potent
Materials Research. Publicado em: 29/02/2012
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23. A fração volátil das aguardentes de cana produzidas no Brasil
The volatile fraction of sugar cane spirits plays a key role in the quality and acceptance of these beverages. The composition of this fraction is dependent on the way sugar cane collection, fermentation, distillation and aging are carried out. The materials used in these processes strongly influence chemical composition. Acetic acid, acetaldehyde, ethyl ace
Quím. Nova. Publicado em: 2012
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24. Chemical constituents from red algae Bostrychia radicans (Rhodomelaceae): new amides and phenolic compounds
This study describes the isolation and structural determination of two amides, isolated for the first time: N,4-dihydroxy-N-(2'-hydroxyethyl)-benzamide (0.019%) and N,4-dihydroxy-N-(2'-hydroxyethyl)-benzeneacetamide (0.023%). These amides, produced by the red macroalgae Bostrychia radicans, had their structures assigned by NMR spectral data and MS analyses.
Quím. Nova. Publicado em: 2012