Stirring
Mostrando 1-12 de 290 artigos, teses e dissertações.
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1. Thermal Infrared Enthalpimetry Method for the Determination of Hypochlorite in Bleaching Solutions
Thermal infrared enthalpimetry (TIE) was used for hypochlorite determination in commercial hypochlorite-based bleaching solutions. Experimental parameters were evaluated for the reaction with a hydrogen peroxide solution. The most relevant conditions were 5% H2O2 (m/m) solution, stirring speed of 250 rpm, dispensing rate of 0.57 mL s-1, and 10 s after reacti
Journal of the Brazilian Chemical Society. Publicado em: 2022
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2. Processamento de catalisadores gastos de unidade de hidrodessulfurização profunda (ultra-deep HDS)
PROCESSING OF SPENT ULTRA-DEEP HYDRODESULFURIZATION CATALYSTS. This work discusses the recycling of spent NiMo/Al2O3 catalysts from ultra-deep hydrodesulfurization (HDS) units. They contain a refractory coke and fouling elements from the processed feedstocks. Samples were preoxidized (600 ºC) for 12 h using a very slow heating rate to eliminate coke and vol
Química Nova. Publicado em: 2022
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3. Mathematical modeling of whey foam mat drying
ABSTRACT This study aimed to fit mathematical models to whey foam drying processes in different air temperature conditions, to determine the effective diffusion coefficient and to obtain the activation energy. For foam formation, 5.0% Emustab® was added to the serum in mass and subjected to stirring in a domestic shaker for 15 min. After, it was spread onto
Rev. Ceres. Publicado em: 2021-08
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4. Dextran Sulfate/Pramlintide Polyelectrolyte Nanoparticles as a Promising Delivery System: Optimization, Evaluation of Supramolecular Interactions and Effect on Conformational Stability of the Peptide Drug
In this study, we investigated the feasibility to obtain nanoparticles (NPs) by assembling pramlintide (Pram) with dextran sulfate (DexS), as a new approach for mucosal peptide delivery. DexS/Pram NPs were prepared by dropwise addition of a Pram solution to a DexS solution under magnetic stirring. The physicochemical characteristics of NPs and molecular inte
J. Braz. Chem. Soc.. Publicado em: 2021-08
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5. PEACH PIT CHEMICALLY TREATED BIOMASS AS A BIOSORBENT FOR METFORMIN HYDROCHLORIDE REMOVAL: MODELING AND SORPTION MECHANISMS
ABSTRACT In this work, the potential of peach pit biosorption in the removal of the drug metformin hydrochloride from water is evaluated. Experiments are carried out in a closed batch system to evaluate the effect of the solution pH (2–10), temperature (25, 35 and 45 °C), stirring (100, 150 and 200 rpm) and chemical treatments. During the study, biosorben
Eng. Agríc.. Publicado em: 2021-04
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6. SIMPLE AND FAST DETERMINATION FOR GAMMA-HYDROXYBUTYRATE (GHB) IN URINE SAMPLE BY LLE AND GC-MS
Gamma-hydroxybutyrate (GHB) is a depressant of the central nervous system able to promote disinhibition, anterograde amnesia and its use is related to Drug-Facilitated Crimes (DFC). Urine is the biological matrix of choice for toxicological analysis in victims of rape and/or theft in suspected victims of DFC. The aim of this work was the development of a sim
Quím. Nova. Publicado em: 2021-02
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7. Optimization of Methodology for Determination of Inorganic Chromium Species in Sewage Sludge Samples by HPLC-ICP-MS/MS
This study developed a methodology for extracting and speciating CrIII and CrVI in sewage sludge by high performance liquid chromatography, inductively coupled plasma tandem mass spectrometry (HPLC-ICP-MS/MS). The optimal procedure was solid-liquid extraction in a water bath with stirring at 50 °C for 16 h and 50 mmol L−1 ethylenediaminetetraacetic acid (
J. Braz. Chem. Soc.. Publicado em: 2020-12
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8. Optimization and characterization of vinegar produced from rice bran
Abstract The vinegar is a millenary food, appreciated by consumers worldwide. The rice bran is a rice-processing by-product produced in a large scale, mainly employed in feed. This study describes a method for defatted rice bran (DRB) vinegar production by submerged fermentation, with optimized aeration and stirring conditions, evaluating its physico-chemica
Food Sci. Technol. Publicado em: 2020-09
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9. DETERMINATION OF THE PESTICIDES IN WATER USED IN THE CULTURE AND PROCESSING OF POTATOES
The contamination of water bodies by pesticide residues through direct flow, leaching and other methods has motivated the development of analytical methods for the determination of these compounds in water. A vortex-assisted liquid-liquid microextraction method followed by gas chromatography coupled to mass spectrometry for the determination of anilazine, li
Quím. Nova. Publicado em: 2020-09
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10. On the possibility of obtaining high-quality lyophilized collagen hydrolysate and its applicability in the sausage production
Abstract The paper discusses the issues of rational use of secondary collagen-containing raw material in the food industry, namely cattle by-products. The technology of obtaining collagen hydrolysate from this type of raw material with the subsequent freeze-drying is proposed, which maximizes the level of preservation of native properties and the expands the
Food Sci. Technol. Publicado em: 2020-09
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11. Simultaneous Transfer of Na+, K+, and Fe2+ Ions During Salting of Precooked Mushroom (Agaricus bisporus): Mathematical Modeling, Optimization, and Experimental Validation
The champignon mushroom has no antinutritional factors that can affect iron bioavailability. It is considered a functional food and can provide health benefits by presenting bioactive components. The simultaneous transfer of Na+, K+ and Fe2+ in the pre-cooked mushroom (Agaricus bisporus) was modeled and simulated by the finite element method (FEM). The Biot
J. Braz. Chem. Soc.. Publicado em: 2020-06
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12. BIODIESEL SYNTHESIS FROM WASTE COOKING OIL USING A VARIETY OF WASTE MARBLE AS HETEROGENEOUS CATALYSTS
Abstract The research article is based on biodiesel synthesis by the transesterification of waste cooking oil with methanol in the presence of heterogeneous catalysts prepared from different marble. Eight samples of marble were successfully converted into potential catalysts by calcination. The thermal treatment of waste marbles at 300oC-1000oC converted the
Braz. J. Chem. Eng.. Publicado em: 13/01/2020