Impurities
Mostrando 1-12 de 334 artigos, teses e dissertações.
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1. Sedimentation and rheological behavior of reactive and non-reactive magnesium hydroxide pulps for industrial spray dryer processing
Abstract Two different reactive concentrated magnesium hydroxide (HM) pulps, produced in a lab reactor mill, and a synthetic and non-reactive HM-pulp, for comparative analyses, have been prepared and studied. Sodium polyacrylate was selected as a dispersant for improving the HM pulp fluidity, with concentrations varying from 0.42% to 2.0% on a dry basis. The
Cerâmica. Publicado em: 2023
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2. Synthesis and Evaluation of Antibacterial Activity of 1,2,3-Triazole and Ether Derivatives of Paeonol
Multi-drug-resistant bacteria (MDR) are the cause of different infections and diseases that have affected humanity for a long time, and have been an emerging global health problem that has led to increased morbidity and mortality. The growing emergence of MDR bacteria has underlined the need for development and discovery of new antibacterial compounds. In th
Journal of the Brazilian Chemical Society. Publicado em: 2023
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3. Characterization of a complex carbonate-silicate apatite ore and its concentration by a two-stage anionic flotation method
Abstract A carbonate-silicate low weathering phosphate ore from an igneous origin deposit in Southeastern Brazil presents a challenge mainly for apatite flotation from its gangue minerals, calcite and dolomite, plus the presence of phlogopite, diopside, magnetite, richterite, ilmenite, vermiculite, quartz and many other minor impurities. Recently, selectivit
REM - International Engineering Journal. Publicado em: 2022
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4. Estimation of percentage of impurities in coffee using a computer vision system
RESUMO A qualidade e o valor da bebida do café podem ser afetados pela contaminação de impurezas durante a torra e moagem. Métodos que permitem o controle de qualidade do produto comercializado são importantes para atender aos padrões exigidos pelos consumidores e pela indústria. Objetivou-se neste estudo estimar o percentual de impurezas contidas no
Revista Brasileira de Engenharia Agrícola e Ambiental. Publicado em: 2022
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5. Characterization and mechanical properties of one-part geopolymer based on a pure metakaolin
Abstract Geopolymers are amorphous silicate polymers that have been extensively studied due to their applications, scientific and technical relevance, and their potential as cement in substitution to Portland. Much of the focus has been in the use of precursors and aggregates that are rarely pure and homogeneous with the use of tailings being very common. Th
REM - International Engineering Journal. Publicado em: 2022
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6. Purification of raw palygorskite: a comparative study involving different processes and dispersing agents
Abstract Palygorskite (Pal) is a natural clay mineral with fibrous morphology and high surface area. Depending on the geological origin, it presents impurities, such as quartz and carbonates, which can harm some of its properties. Therefore, this work seeks to define a viable methodology for the purification of a Brazilian Pal. Two types of mixing processes
Cerâmica. Publicado em: 2021-06
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7. DOES MOISTURE IN PODS INTERFERE WITH MECHANIZED HARVESTING OF PEANUTS?
ABSTRACT Although peanut harvesting results in significant losses, it has rarely been investigated. Thus, this study aimed to analyze the interference of different pod moisture contents on peanut harvesting and their influence on the process quality based on losses and impurities. An experiment was performed in a peanut seed producing area, in Luzitânia, di
Eng. Agríc.. Publicado em: 2021-02
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8. Brazilian Mineral Clays: Classification, Acid Activation and Application as Catalysts for Methyl Esterification Reactions
In this study, three raw Brazilian clays from João Pessoa, Paraíba State (Aço AP, AVL and Verde Lodo) were characterized before and after purification and acid activation. Several instrumental techniques were used, and the raw clays were classified as dioctahedral smectites with different compositions, where the AVL sample had the highest content of montm
J. Braz. Chem. Soc.. Publicado em: 2021-01
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9. Method for Cleaning Back-Produced Water from Polymer Flooding Operations to Determine Polymer Molar Mass Using Size-Exclusion Chromatography
One of the methods used by the oil industry to increase production is to inject water, containing polymer, into the reservoir. The viscosity of the aqueous solution is primarily responsible for the efficiency of this method, and is achieved using polymers with high molar mass. However, polymer degradation can occur during pumping and fluid displacement in th
J. Braz. Chem. Soc.. Publicado em: 2020-12
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10. AN APPROACH BASED ON ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY TO STUDY THE GLYCEROL/BIODIESEL GRAVITY SEPARATION
In this study, electrochemical impedance spectroscopy (EIS) is evaluated as a novel application in the biodiesel purification process. EIS is proposed as a tool to study the behavior of charge carriers produced from side reactions or dissociations of some impurities during the gravitational separation of glycerol dispersed in crude biodiesel after the transe
Quím. Nova. Publicado em: 2020-12
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11. Preparation of Fluorescent Carbon-Based Dots from Waste Tire Pyrolysis
The pyrolysis of waste tire has been proposed as an alternative route to its recycling producing residual oils that can be used as fuels. In this work, a physicochemical process to obtain carbon-based dots (CBD) from carbon black (CBL) derivatives of tires is described. For this, the CBL was treated with different acids to produce CBL1 and CBL2 particles sus
J. Braz. Chem. Soc.. Publicado em: 2020-11
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12. 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