Hydrocarbons
Mostrando 1-12 de 1045 artigos, teses e dissertações.
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1. Fast Catalytic Pyrolysis of Tetradecanoic Acid: Formation of Ketones as Intermediate Compounds in the Production of Hydrocarbons
This work aimed to compare two different catalysts in the production of a long chain ketone, intermediate in the production of hydrocarbons, during pyrolysis of tetradecanoic acid as a model fatty acid. The studied variables were the temperature, 450 and 600 ºC, and catalysts, γ-Al2O3 and Nb2O5, the latter has never been studied under such conditions. Pyro
Journal of the Brazilian Chemical Society. Publicado em: 2022
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2. A Physical Study to Explain Response Differences between the BID and FID Detectors for PAHs and Pesticides
The dielectric barrier discharge ionization detector (BID) is one of the most modern detectors commercially available for gas chromatography (GC). Its technology based on the sample ionization through the energy released from the helium plasma generation process gives it the ability to act as a universal detector and a greater response to various types of co
Journal of the Brazilian Chemical Society. Publicado em: 2022
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3. Biodiesel: An Overview II
The crescent number of scientific articles published per year shows that research on biodiesel continues to play an important role to support the growing demand for this biofuel. The second edition of Biodiesel: An Overview presents the worldwide research in the last 15 years. Microalgae biomass is the most studied raw material alternative in this period and
J. Braz. Chem. Soc.. Publicado em: 2021-07
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4. A Gas Chromatography Method for Simultaneous Quantification of Inorganic Gases and Light Hydrocarbons Generated in Thermochemical Processes
This paper reports a method for simultaneous determination of H2, O2, N2, CO, CO2, CH4, C2H2, C2H4, C2H6, C3H4 (propadiene and propyne), C3H6, C3H8 and C4H10 (n-butane and isobutane) by gas chromatography using thermal conductivity and flame ionization detectors. A single porous layer open tubular column (0.53 mm internal diameter ? 30 m length ? 30 µm thic
J. Braz. Chem. Soc.. Publicado em: 2021-06
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5. Effects of Polycyclic Aromatic Hydrocarbon Pendant-Armed Ligands on the Catecholase Activity of Dinuclear Copper(II) Complexes
Herein, we present three new binuclear copper(II) complexes containing different polycyclic aromatic hydrocarbons, able to catalyze the oxidation of 3,5-di-tert-butylcathecol, a model substrate for catechol oxidase. The ligands and complexes were successful characterized in solid and solution states. The structure of C1 was determined by X-ray crystallograph
J. Braz. Chem. Soc.. Publicado em: 2021-05
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6. Thermal and Catalytic Fast Pyrolysis of Oily Extracts of Microalgae: Production of Biokerosene
Three different microalgae species, Desmodesmus sp., Nannochloropsis oculata and Halamphora coffeaeformis were grown under controlled conditions. The resulting dry biomass was characterized by TG-DTA (thermogravimetry-differential thermal analysis) and extracted with three solvents having different polarities. The extracts gross mass yields varied from 2% us
J. Braz. Chem. Soc.. Publicado em: 2021-04
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7. EVALUATION OF THE CHEMICAL COMPOSITION AND STRUCTURE OF ASPHALTENES FROM THREE OFFSHORE BRAZILIAN BIODEGRADED HEAVY OILS
Asphaltenes fractions were extracted and purified from three heavy Brazilian oils. Their mass compositions of C, H, N, Ni and V were obtained from elemental analysis and S and O atomic percentages from EDS. The H/C ratios showed high degree of unsaturation, while the O atomic percentages indicated more pronounced biodegradation effects on two samples. Quanti
Quím. Nova. Publicado em: 2021-04
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8. Multivariate Optimization of Extraction Variables of PAH in Particulate Matter (PM10) in Indoor/Outdoor Air at Campos dos Goytacazes, Brazil
Polycyclic aromatic hydrocarbons (PAH) are products of incomplete combustion of biomass and fossil fuels, that are produced on a larger scale by anthropogenic sources. Burning sugarcane plantations can be a source of atmospheric PAH in regions where this culture predominates. Campos dos Goytacazes, Brazil, is surrounded by sugarcane crops that still use fire
J. Braz. Chem. Soc.. Publicado em: 2021-03
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9. The effects of adding garlic (Allium sativum L.) on the volatile composition and quality properties of yogurt
Abstract In this study, the effects of adding garlic (Allium sativum L.) of different origins on the volatile composition and quality properties of yogurt were investigated on day 1, 7 and 14 of storage. The addition of garlic did not cause a decrease in the total specific microorganism count (>107) in yogurt samples, and it led to a significant decrease in
Food Sci. Technol. Publicado em: 2020-12
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10. Simultaneous determination and difference evaluation of volatile components generated from ginseng fruit by HS-SPME Coupled with GC-MS according to fruit color
Abstract The volatile components of fruits of Panax ginseng C.A. Meyer analyzed to interpret whether fruits color affect volatile components. The volatile components in ginseng fruits cultured with 3 different clolors such as red fruits, yellow fruits and orange fruits were isolated by head-space solid-phase microextraction fiber (polydimethylsiloxane 100 μ
Food Sci. Technol. Publicado em: 2020-09
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11. A UNIFIED FORMULA FOR HYDROCARBONS WITH APPLICATIONS TO FUNCTIONAL GROUPS
Was supposed a numerical relationship between atoms of Hydrogen and Carbon in a hydrocarbon, assumption valid for all types of chains. In the proposed equation, variables such as number and types of carbon bonds are present, as well as the possible cycles. It was shown that the equation reduces to the known “general formulas” when applied to the type of
Quím. Nova. Publicado em: 20/07/2020
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12. Mango (Mangifera indica) Aroma Discriminate Cultivars and Ripeness Stages
Mango (Mangifera indica) has many nutritional attributes that stimulate its consumption, such as sweetness, balanced acidity and intense fruity aroma. In this study, it was demonstrated that both the variety and ripening stage have a significant impact on the aroma of mango. The volatile compound profile of “Tommy Atkins”, “palmer”, “espada” and
J. Braz. Chem. Soc.. Publicado em: 2020-07