Chemical Precipitation
Mostrando 1-12 de 266 artigos, teses e dissertações.
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1. Influence of Refinery Asphalt Residue Addition on Flow: A Study Using Waxy Model-System
One of the main phenomena causing problems in the oil industry is the precipitation of waxes, which can crystallize and form deposits, clogging lines and reducing flows. Many studies have been conducted seeking to overcome this problem, mainly through application of chemical to increase flow. Some studies have shown that the asphaltenes present in crude oil
Journal of the Brazilian Chemical Society. Publicado em: 2023
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2. Ferrimagnetic to paramagnetic transition and dielectric relaxation in Ni1-xZnxFe2O4 ferrites
Abstract The spinel ferrite system Ni1-xZnxFe2O4 (x=0-0.7, Δx=0.1) was prepared by wet chemical co-precipitation method using sulfates of respective metal ions. The electrical resistivity and dielectric properties of the prepared samples have been studied as a function of temperature, frequency, and Zn content (x). The DC resistivity (ϱ) was measured in th
Cerâmica. Publicado em: 2021-06
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3. Synthesis, Characterization and Exchange Reactions of Layered Double Hydroxides of Copper and Aluminum, Intercalated with Sulfate
Layered double hydroxides (LDHs) of Cu:Al in the molar ratio of 2:1, intercalated with sulfate, sulfate/(Li+, Na+, K+ or NH4+), NO3- and CO32-, were synthesized by co-precipitation with increasing pH. The materials were submitted to exchange reactions using B2SO4 (B = Li+, Na+, K+, NH4+) solutions in an attempt to replace previously intercalated cations or i
J. Braz. Chem. Soc.. Publicado em: 2021-01
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4. Analysis of carbonation and hydration of BOF steel slag for application as railway ballast
Abstract The reutilization of waste is a valuable alternative for the preservation of natural resources and the environment. In this sense, Basic Oxygen Furnace (BOF) steel slag is one of the most residues generated in steel the industry. It is estimated that for each ton of steel produced, about 150 kg of steel slag is generated in the BOF process. Generall
REM, Int. Eng. J.. Publicado em: 2020-12
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5. Evaluation of polyelectrolyte and emulsion covalent crosslink of chitosan for producing mesalasine loaded submicron particles
This study evaluates various techniques for producing mesalamine (5ASA)-loaded particles employing chitosan as a biopolymer: (1) the polyelectrolyte complexation of chitosan with phthalate hypromelose (HP), (2) the chemical crosslinking of chitosan with genipin and (3) the water-in-oil emulsion method associated with chemical crosslinking with genipin. Syste
Braz. J. Pharm. Sci.. Publicado em: 20/12/2019
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6. Produção de biossurfactantes: manoproteínas intracelulares e soforolipídios extracelulares por Saccharomyces cerevisiae
RESUMO Os biossurfactantes apresentam inúmeras aplicações ambientais e são produzidos por diversos microrganismos. Os provenientes da levedura Saccharomyces cerevisiae são pouco estudados para fins ambientais, sendo atóxicos. Objetivou-se o estudo da produção de biossurfactantes intra e extracelular por essa levedura, desenvolvida em meio de cultivo
Eng. Sanit. Ambient.. Publicado em: 20/12/2019
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7. Metals and dissolved organic carbon (DOC) of surface waters in two adjacent watersheds in the eastern Amazon
Resumo A intensificação do uso da terra na região da “Zona Bragantina”, uma área da Amazônia Oriental brasileira, acelerou as mudanças de paisagem da floresta primária para uma mistura de diferentes usos da terra: floresta (vegetação ripária), floresta secundária, pastagem, terra agrícola anual, terra cultivada perene, solo descoberto e veget
Rev. Ambient. Água. Publicado em: 28/11/2019
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8. Corrosion Resistance of Cu-Alloyed Precipitation Hardenable Duplex Stainless Steel ASTM A890 Grade 1B
Duplex stainless steels (DSS) are corrosion resistant alloys largely used in chemical and petrochemical industries. Some commercial DSS contain 0.5-1.0% copper addition to improve the corrosion resistance by reducing the corrosion rate in non-oxidizing environments. Higher copper addition (≥ 2%) can also hard by precipitation, especially when fine copper p
Mat. Res.. Publicado em: 07/11/2019
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9. HDL-PARTICLES SEPARATION EMPLOYING DIFFERENT PRECIPITATING AGENTS: FUNCTIONAL PROPERTIES OF THE IMPACT OF CHEMICAL PRECIPITATION ON LIPOPROTEIN PARTICLE-SIZE AND PARAOXONASE-1-ACTIVITY
First-generation methods used to quantify HDL-cholesterol have been used for decades. Therefore, first-generation precipitatingreagents still in use, the chemical impact on HDL-particles functionality (structure/activity-relationship) is not well-documented. The study aim was to identify the most efficient precipitating-reagent for lipoprotein separation to
Quím. Nova. Publicado em: 21/10/2019
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10. Phase Separation and Development of the Microstructure for Stainless Steel to Copper Alloy Weld Joints Using a Fiber Laser
ABSTRACT Stainless steel and copper alloys joints are often applied in aerospace, marine and power industries where both high thermal and electrical conductivity (Cu) and corrosion resistance (steel) are required. In the aerospace industry, in particular for the combustion chamber of rocket engines, copper and steel combinations offer perfect materials selec
J. Aerosp. Technol. Manag.. Publicado em: 10/10/2019
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11. Development of hollow fiber membranes with alumina and waste of quartzite
The development of ceramic membranes with different geometries and compositions extends the possibilities of industrial applications, inducing advantages in terms of increased permeability, membrane area by volume module and chemical, thermal and mechanical resistance. The use of low-cost raw materials is a trend that has grown in scientific research. The ai
Mat. Res.. Publicado em: 12/08/2019
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12. Evaluation of the use of fertilizer obtained from pharmaceutical effluent
Resumo A sustentabilidade envolve um número grande de aspectos. Entre eles, o de aproveitamento de nutrientes presentes em efluentes tratados com diferentes tipos de processos. Nos últimos anos, têm sido detectados danos ambientais decorrentes do despejo de fármacos e de efluentes da indústria farmacêutica, em função da difícil recalcitrância de al
Rev. Ambient. Água. Publicado em: 18/07/2019