Temperature Influence
Mostrando 1-12 de 2254 artigos, teses e dissertações.
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1. The Contribution of Meteorological Parameters and the COVID-19 Partial Lockdown on Air Quality in Rio de Janeiro, Brazil
This study evaluated the pollutant levels (NO2, SO2, CO, and O3), air quality index (AQI) and the influence of meteorological variables and coronavirus disease (COVID-19) pandemic on the air quality in Rio de Janeiro. The data set used comprises periods before (March-April, 2019) and during pandemic (March-April, 2020). According to the AQI results, on most
Journal of the Brazilian Chemical Society. Publicado em: 2023
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2. The Influence of the Platinum Weight Percentage in the Catalyst Formulation on the Performance of a High Temperature Ethanol Electroreformer Based on H3PO4 Doped Polybenzimidazole for Green Hydrogen Production
A vapor-fed high temperature proton exchange ethanol electroreformer has been developed based on the use of a H3PO4-doped polybenzimidazole membrane to produce green hydrogen. As a key parameter, this article describes the influence of platinum weight percent (wt.%) in the catalyst formulation from different commercial catalysts (20, 40, 60, 80 wt.% Pt/C and
Journal of the Brazilian Chemical Society. Publicado em: 2022
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3. Influence of shadowing in Sequoia sempervirens (D. Don) Endl. mini-stumps and mini-cuttings
ABSTRACT The aim of the work was to analyze the influence of variables such as shading, temperature and humidity in the production and rooting of mini-cuttings of Sequoia sempervirens (D. Dom) Endl. in a clonal mini-garden. The experiment was conducted at the Forest Nursery at the University of Santa Catarina State - CAV/UDESC, Lages - SC. The minicuttings w
Revista Ceres. Publicado em: 2022
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4. Interaction of Lead and Calcium with Biochar Produced from Cassava Waste: Perspectives for Agricultural and Environmental Application
Biochar from slow pyrolysis under controlled conditions is favorable in the transformation of waste into materials that serve as soil conditioners, and/or environmental remediation. Thus, this work aimed to produce and characterize biochar from cassava waste under different temperature conditions and evaluate interactions with Ca2+ and Pb2+ for agricultural
Journal of the Brazilian Chemical Society. Publicado em: 2022
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5. Development of a ceramic membrane for emulsion water-diesel treatment
Abstract The purpose of this study was the development of a low-cost ceramic tubular membrane, using inexpensive materials, namely natural clay, and graphite as a porogenic agent. Such a low-cost membrane can be used as filters or porous supports for the preparation of multilayer ceramic membranes. Extrusion was used as a shape-forming method for this purpos
Cerâmica. Publicado em: 2022
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6. Structural Characteristics of Lignite Char from Different Pyrolysis Reactors and the Influence on Their Gasification Reactivity
The gasification reactivity of coal char is affected by numerous experimental variables, and char structure is one of the dominant factors. In this work, Raman spectroscopy, powder X-ray diffraction (XRD), and N2 adsorption were used to investigate the physical and chemical structure of char prepared under different pyrolysis conditions. Three kinds of pyrol
Journal of the Brazilian Chemical Society. Publicado em: 2022
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7. Water footprint of Arabica coffee from “Matas de Minas” under shade management
ABSTRACT Studies related to climate change and agricultural value chains have in common the growing concern on conserving water resources. Thus, the concept of the water footprint stands out, which measures the amount of water (in volume) necessary to produce a unit (in mass) of a given product. Among Brazilian agricultural activities, coffee farming emerges
Revista Ceres. Publicado em: 2022
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8. Extraction optimization and antioxidant activity of Phyllanthus urinaria polysaccharides
Abstract Three extraction parameters including extraction time, material to solvent ratio, and extraction temperature for the extraction yield of Phyllanthus urinaria polysaccharides were optimized by response surface methodology. The results revealed that the optimal extraction process was extraction time of 5.3 h, extraction temperature of 93 °C, and mate
Food Sci. Technol. Publicado em: 2021-06
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9. STUDY ON THE OPTIMIZATION FOR THE SIZE OF FUEL CELL FLOW FIELD UNDER INADEQUATE AIR SUPPLY CONDITION
In this paper, the influence of the optimization for flow field size on the proton exchange membrane fuel cell (PEMFC) performance under the inadequate air supply of cathode was studied based on the three-dimensional, steady-state, and constant temperature PEMFC monomer model. Additionally, the effect of the optimization for hybrid factors, including length,
Quím. Nova. Publicado em: 2021-04
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10. The Stabilization of Asphaltenes in Different Crude Fractions: A Molecular Approach
The conditions of petroleum extraction may allow asphaltenes to precipitate, causing deposition that clogs wells, pipes and equipment, consequently reducing productivity. In this work, the solubility parameters and precipitation onset of polar fractions of heavy crudes from Brazilian fields were estimated using a simplified system of n-heptane/toluene mixtur
J. Braz. Chem. Soc.. Publicado em: 2021-04
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11. AVALIAÇÃO QUÍMICA DE LENHOS CARBONIZADOS DE Araucaria columnaris SOB DIFERENTES CONCENTRAÇÕES DE OXIGÊNIO COMO COMPARATIVO DE ANÁLISE DE charcoal FÓSSIL
In the face of environmental changes concerns, the study of climate change becomes essential to understand the life trajectory of planet earth. For this purpose, this work seeks to understand climate change and fluctuations in the amount of atmospheric oxygen across geological ages, carbonizing the Araucaria columnaris wood in varying oxygen concentrations,
Quím. Nova. Publicado em: 2021-03
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12. Influence of sintering parameters on the microstructure and mechanical properties of nanosized 3Y-TZP ceramics
Abstract The fracture toughness of 3Y-TZP ceramics obtained from a nanocrystalline powder with an optimized microstructure and highly transformable tetragonal grains was investigated. Samples of ZrO2-3 mol% Y2O3 were sintered at temperatures between 1250 and 1400 °C, with isothermal holding times of up to 16 h. Samples sintered at 1250 °C exhibited relativ
Cerâmica. Publicado em: 2021-03