Time Varying
Mostrando 1-12 de 932 artigos, teses e dissertações.
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1. Tailoring the properties of Y2O3 via synthesis parameters varied during the PVA-assisted sol-gel route
Abstract The effect of synthesis parameters on the microstructural behavior and morphology during the yttrium oxide (Y2O3) formation is reported. Y2O3 crystals were produced by a modified sol-gel route assisted by polyvinyl alcohol solution varying the calcination temperature and solution pH. The crystalline phase formation was investigated using X-ray powde
Cerâmica. Publicado em: 2023
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2. Zeólita NaA sintetizada sobre fibra de vidro como estratégia para otimização do abrandamento de águas duras
NaA ZEOLITE SYNTHESIZED OVER FIBERGLASS AS A STRATEGY FOR OPTIMIZING HARD WATER SOFTENING. Zeolite NaA has been successfully synthesized over glass fiber surface previously activated by alkaline treatment. By varying the time of the treatment and the amount of silica and alumina precursors used in the reaction mixture, a sample with higher zeolite concentrat
Química Nova. Publicado em: 2022
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3. Bioconjugation Between CdTe Quantum Dots and a Cationic Protein: An Analytical Method to Determine Protamine in Drug and Urine Samples
CdTe quantum dots (QD-CdTe) functionalized with mercaptosuccinic acid (MSA) were synthesized in an aqueous medium, varying synthesis time from 0.5 to 4 h. The nanoprobe were characterized by a direct relationship between synthesis time and QD size (2.61-3.04 nm). The QD-CdTe-MSA interacted with protamine (PT), a cationic protein, forming a bioconjugate, thus
J. Braz. Chem. Soc.. Publicado em: 2021-06
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4. MACROALGAE Fucus vesiculosus OIL: BIODIESEL PRODUCTION USING ALKALINE TRANSESTERIFICATION
This work studied the obtaining of methyl biodiesel and ethyl biodiesel using alkaline transesterification from macroalgae Fucus vesiculosos oil (FVO). FVO has 86.59% of its composition in unsaturated fatty acids, with a greater quantity of linoleic acid and oleic acid, a chemical composition near the soybean oil, the most used raw material for the productio
Quím. Nova. Publicado em: 2021-04
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5. 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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6. Large strain consolidation analyses of fine tailings disposal in mining pits
Abstract Herein, three-dimensional analyses of large strain consolidation applied to tail ings disposal in mining pits is studied. The main goal is to estimate filling time and, ac cordingly, the capacity of the pit. Other useful results, such as dry density profiles and water pore pressure generation are also obtained. Two different slimes from the iron or
REM, Int. Eng. J.. Publicado em: 2020-09
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7. Preserve Planet EARTH. If not you, WHO? If not Now, WHEN?
Abstract Herein, three-dimensional analyses of large strain consolidation applied to tail ings disposal in mining pits is studied. The main goal is to estimate filling time and, ac cordingly, the capacity of the pit. Other useful results, such as dry density profiles and water pore pressure generation are also obtained. Two different slimes from the iron or
REM, Int. Eng. J.. Publicado em: 2020-09
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8. Aqueous Extracts of the Castor Beans as a Corrosion Inhibitor of Mild Steel in HCl Media
The present work studied aqueous extracts of castor beans as a natural inhibitor of the corrosion of mild steel in 1 M HCl using gravimetric tests, potentiodynamic polarization curves, linear polarization method, electrochemical impedance measurements, surface analysis by scanning electron microscopy (SEM) and chemical characterization by Fourier transform i
J. Braz. Chem. Soc.. Publicado em: 2020-06
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9. Retorno Salarial do Overeducation: Viés de Seleção ou Penalização ao Excesso de Escolaridade?
Resumo Este paper investiga os efeitos salariais do overeducation, situação na qual trabalhadores exercem funções com escolaridade requerida inferior. Para isso, utilizou-se dados de graduados da Universidade Federal da Paraíba de 2003 a 2013. A estimação de um OLS com efeitos fixos dos indivíduos e das firmas, mais interações destes com o tempo co
Rev. Bras. Econ.. Publicado em: 2020-06
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10. Reporting the utilization and perspectives of different surface active agents for bread making
Abstract The present study was planned to use surfactants in different concentrations along with varying amounts of shortening in the form of gels to prepare breads. For that purpose, SSL, CSL, PS-60 and GMS were used at level of 0.25, 0.50, 0.75 and 1.00 parts in combination with shortening @ 4.00, 3.75, 3.50 and 3.25 parts. The dough having surfactants gel
Food Sci. Technol. Publicado em: 2020-06
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11. EXPERIMENTAL AND NUMERICAL ANALYSIS OF CHAOTIC ADVECTION AS AN EFFICIENT APPROACH TO MAXIMIZE HOMOGENEOUS LAMINAR MIXING IN A BATCH MIXER
Abstract In the present work, the impacts of effective parameters on the mixing of Stokes flows in a chaotic batch mixer are numerically and experimentally studied. The batch mixer consists of a container and two circular rotors where the rotors can rotate independently. To investigate the possibility of improving the mixing, the effect of non-constant speed
Braz. J. Chem. Eng.. Publicado em: 13/01/2020
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12. Effect of Scanning Speed on the Surface Roughness of Laser Metal Deposited Copper on Titanium Alloy
This paper reports on the effect of scanning speed on the laser deposited Cu on titanium alloy substrate. The experiments were conducted by varying the scanning speed from 0.3 m/min to 1.2 m/min while the laser power, the powder feed rate and the gas flow rate were kept constant. The laser deposited Cu were characterized through the evolving microstructure a
Mat. Res.. Publicado em: 20/12/2019