Precipitation Chemistry
Mostrando 1-12 de 34 artigos, teses e dissertações.
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1. Films Formed on Carbon Steel in Sweet Environments - A Review
Corrosion of carbon steel pipelines in sweet environments has been extensively researched on oil and natural gas exploration and production in order to obtain efficient corrosion mitigation methods. Although the consequences of corrosion are known, the cause and mechanism by which a certain phenomenon occurs are still not well understood. Sweet corrosion is
J. Braz. Chem. Soc.. Publicado em: 04/07/2019
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2. Apatite multi-generations in the Três Estradas Carbonatite, Southern Brazil: physical and chemistry meaning and implications to phosphate ore quality
Abstract Carbonatites were recently discovered in Southern Brazil, which increased the interest to evaluate the economic potential of these uncommon rocks, especially the Três Estradas Carbonatite. Carbonates are the dominant minerals of fresh rock followed by apatite, but the weathering process makes apatite abundant. We focused on apatite from the carbona
Braz. J. Geol.. Publicado em: 01/07/2019
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3. Geochemistry, metamorphic evolution and tectonic significance of metabasites from Caçapava do Sul, southern Brazil
Abstract This paper proposes the generation and closure of a proto-ocean and formation of an island arc in the Neoproterozoic Passo Feio Metamorphic Complex (PFMC), Caçapava do Sul region, southern Brazil. The PFMC, São Gabriel Terrane, consists of a Neoproterozoic supracrustal metavolcano-sedimentary sequence intruded by the Caçapava Granite. The study u
Braz. J. Geol.. Publicado em: 29/04/2019
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4. UM ESTUDO TERMODINÂMICO DA CORROSÃO DOS AÇOS CARBONO PELO SULFETO DE HIDROGÊNIO - EXPLORANDO CONCEITOS DE EQUILÍBRIO QUÍMICO
This study addresses an inherent problem to the oil and natural gas exploration and production industry, the corrosion of pipes and tanks by H2S. H2S with water emulsified in the oil or H2S with the water vapor mixed in the gas, they make the acid environment leading to corrosion. This is commonly manifested by the formation of insoluble sulfides on the surf
Quím. Nova. Publicado em: 2018-05
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5. CALCULATION OF CONDITIONAL EQUILIBRIUM IN SERIAL MULTIPLE PRECIPITATION OF METAL SULFIDES WITH HYDROGEN SULFIDE STREAM GENERATED FROM SODIUM SULFIDE: A DIDACTIC TOOL FOR CHEMISTRY TEACHING
Hydrogen sulfide is presented in textbooks as toxic, environmentally unacceptable species, however some positive effects in human metabolism were discovered in the last decades. It is important to offer students also some new information about this compound. As didactic tool in this case may serve serial precipitation of Cd2+, Cu2+, Zn2+, Mn2+ and Pb2+ ions
Quím. Nova. Publicado em: 2016-07
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6. TREATMENT OF WASTE FROM ATOMIC EMISSION SPECTROMETRIC TECHNIQUES AND REUSE IN UNDERGRADUATE LAB CLASSES FOR QUALITATIVE ANALYSIS
Flame atomic absorption spectrometry (FAAS) and inductively coupled plasma optical emission spectrometry (ICP OES) are widely used in academic institutions and laboratories for quality control to analyze inorganic elements in samples. However, these techniques have been observed to underperform in sample nebulization processes. Most of the samples processed
Quím. Nova. Publicado em: 2015-11
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7. Aspectos da biogeoquímica dos rios Teles Pires e Cristalino - MT / Aspects of the biogeochemistry of Teles Pires and Cristalino rivers - MT
The Amazon basin occupies around 40% of the brazilian territory and contains more than 60% of the water resources of the country. Abundant and yet little exploited region water resources constitute a national treasure to which the nation can not turn its back. Besides changes in land use/cover, several hydroelectrical plants are planned for rivers in the reg
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 04/06/2012
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8. Dinâmica natural e ensino de Química para jovens e adultos : saberes e práticas de uma inovação curricular / Natural dynamics and teaching chemistry to adult education : knowledge and practices of curriculum innovation
The curricular innovation was applied and evaluated to understand terrestrial environments in order to teach chemical concepts. Contents were organized to understand a social and environmental problem. The issue was chosen to attract adult students. The houses of people in the city of Cajamar (in the Brazilian state of São Paulo) were destroyed or damaged b
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 28/07/2011
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9. Nanopartículas de ácido hialurônico produzidas por nanoprecipitação e reticulação química : processos e caracterização / Hyaluronic acid nanoparticles produced by nanoprecipitation and chemical crosslinking : processes and characterization
O ácido hialurônico (AH) é um mucopolissacarídeo natural, hidrofílico, composto de unidades alternadas de N-acetil-D-glicosamina e ácido D-glucurônico, unidas por ligações ?- 1,3 e ?-1,4. Ele possui diversas aplicações médicas, farmacêuticas e cosméticas, nas quais ele é usado na sua forma nativa ou reticulado, formando hidrogéis de alta visc
Publicado em: 2011
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10. Estudos químicos e anatômicos em espécies de Myrtaceae e Asteraceae e primeiros registros de coléteres em Myrtaceae / Chemical and anatomical studies in Myrtaceae and Asteraceae species and first report of colleters in Myrtaceae
This paper presents data on the chemical composition and antibacterial activity of volatile oils fron three Myrtaceae genera (Callistemon, Kunzea and Melaleuca) grown in Brazil, and one species of the Asteraceae family (Sphagneticola trilobata), ruderal and used in folk medicine. The volatile oils of Myrtaceae species were investigated for its chemical compo
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 20/12/2010
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11. Fracionamento de polifosfato de sódio e caracterização por RMN de 31P: um experimento para aulas de físico-química
This text describes an experiment on fractional precipitation of a polymer together with determination of average degree of polymerization by NMR. Commercial sodium polyphosphate was fractionated by precipitation from aqueous solution by adding increasing amounts of acetone. The polydisperse salt and nine fractions obtained from it were analyzed by 31P Nucle
Química Nova. Publicado em: 2010
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12. Programa de gerenciamento de resíduos químicos do CENA/USP: avaliação, ações de aperfeiçoamento e de extensão / Chemical waste management program of CENA/USP: assessment, improvement and extension actions
The generation of chemical waste in industry is very high, therefore the effluent discharge has been monitored by environmental inspections with greater intensity, to avoid environment contamination. The volume of waste generation is very small in universities, but the diversity is too large, what makes the treatment more difficult. Nevertheless, there are a
Publicado em: 2010