Elemental Chemistry
Mostrando 1-12 de 19 artigos, teses e dissertações.
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1. Modeling and prediction of sulfuric acid digestion analyses data from PXRF spectrometry in tropical soils
ABSTRACT Sulfuric acid digestion analyses (SAD) provide useful information to environmental studies, in terms of the geochemical balance of nutrients, parent material uniformity, nutrient reserves for perennial crops, and mineralogical composition of the soil clay fraction. Yet, these analyses are costly, time consuming, and generate chemical waste. This wor
Sci. agric. (Piracicaba, Braz.). Publicado em: 04/11/2019
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2. Surface modification of activated carbon by corona treatment
Surface modification may lead activated carbon (AC) to take on different properties. This study aimed to promote surface modification of activated carbons using corona treatment (electrical discharge). In this study, powdered commercial activated carbon was used. Activated carbons were subjected to corona treatment at different exposure times (2, 5, 8 and 10
An. Acad. Bras. Ciênc.. Publicado em: 21/03/2019
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3. Caracterização química elementar e identificação de fontes de obsidianas utilizando fluorescência de raios X com equipamento portátil (PXRF)
The study of archaeological and cultural heritage artifacts by means of analytical techniques with portable equipment has become increasingly routinely today. Various types of portable EDXRF equipment have been used in many different situations involving in situ analysis covering a wide range of geometries, detectors, current and voltage applied in the X-ray
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 26/03/2010
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4. CARACTERIZAÇÃO E QUANTIFICAÇÃO MINERALÓGICA DA FRAÇÃO ARGILA DO HORIZONTE Bi DE CAMBISSOLOS DA REGIÃO DE IRATI, PARANÁ, PELO MÉTODO DE RIETVELD
Para fazer uso dos benefícios decorrentes do desenvolvimento da agricultura é necessário conhecer propriedades físicas e químicas do solo que possibilitem a reposição de nutrientes por adubação mineral e orgânica de forma correta. Estas propriedades do solo variam em grande parte de acordo com o teor e composição dos minerais da fração argila.
Publicado em: 2010
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5. Synthesis and characterization of energetic thermoplastic elastomers for propellant formulations
Abstract: Synthesis and characterization of energetic ABA-type thermoplastic elastomers for propellant formulations has been carried out. Following the working plan elaborated, the synthesis and characterization of Poly 3-bromomethyl-3-methyl oxetane (PolyBrMMO), Poly 3- azidomethyl-3-methyl oxetane (PolyAMMO), Poly 3,3-bis-azidomethyl oxetane (PolyBAMO) and
J. Aerosp. Technol. Manag.. Publicado em: 2009-06
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6. Synthesis, characterization and application adsorptive of a new sililante agent immobilized on silica gel by different routes. / Síntese, caracterização e aplicação adsortiva de um novo agente sililante imobilizado na sílica gel por rotas distintas
The reaction between 3-aminopropyltriethoxysilane (AMPTS) with thioglycolic acid (TGA) resulted in a new sililante agent, AMPTGA. This matrix has nitrogen, oxygen and sulfur as basic centers, that have ability to adsorb metallic cations in solution. Immobilization of AMPTGA onto silica gel surface was developed by using conventional heterogeneous method, usi
Publicado em: 2009
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7. SÍNTESE, ESTUDOS ESPECTROSCÓPICOS E ESTRUTURAIS DE COMPLEXOS CONTENDO O LIGANTE 4,4- BIPIRIDINA, O ÂNION BARBITURATO E OS ÍONS METÁLICOS DA PRIMEIRA SÉRIE DE TRANSIÇÃO (Fe2+, Co2+, Ni2+, Cu2+ e Zn2+)
This work describes the synthesis and characterization of five new transition metal complexes of general formula MB2Bipy.10H2O (where M = Fe2+, Co2+, Ni2+, Cu2+ and Zn2+, B is barbiturate anion and Bipy is 4,4-bipyridine) . Several physical and spectroscopical techniques were used to characterize the compounds, such as elemental analysis (CHN), thermal analy
Publicado em: 2009
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8. Ditiocarbamatos derivados do glicoluril, ácido úrico, ácido parabânico e hidantoína: compostos de coordenação e uso como inibidores de corrosão do bronze
This thesis work is about dithiocarbamates compounds, their synthesis, study and application as corrosion inhibitors. The dithiocarbamates herein studied were synthesized from four substances: glycoluril, uric acid, parabanic acid and hydantoin. The pro-ligands were synthesized through reaction with CS2 and NaOH, characterized via elemental analysis (CHN) an
Publicado em: 2008
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9. Sintese e Caracterização de Derivados da Celulose Modificada com Anidridos Orgânicos : adsorção e Termodinamica de Interação com Cations Metalicos / Synthesis and characterization of cellulose derivatives with organic anhydrides : adsorption and interation thermodynamic metallic cations
Cellulose is a widely available biopolymer in nature and its draws considerable chemical interest due its various useful applications. The polysaccharide modification is primarily based on their hydroxyl group reactivity, which determines the carbohydrate chemistry and their related structures. The chemical modification of cellulose was carried out in a solv
Publicado em: 2007
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10. Talinum patens: Análise por ativação neutrônica instrumental e prospecção fitoquímica
The use of plants for many diseases treatment is a millenary knowledge. These are the great importance for the formation of actual medicine bases. Actually, more than 25 % of the all drugs prescribed in the world are obtained from plants. The medicinal plants and other vegetable materials market reach to around two billions dollars. The researches of natural
Publicado em: 2005
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11. Síntese e caracterização de substâncias semelhantes aos ácidos húmicos de carvão de eucalipto, e sua interação com diclorofenol, cálcio, manganês e alumínio / Synthesis and characterization of humic acid-like substances from eucalypt charcoal, and its interaction with diclorofenol, calcium, manganese and aluminium
A wide range of commercial products containing humic substances have been applied successfully in agricultural and environmental remediation systems. Regarding their beneficial remediation characteristics, there is a high potential to adsorb heavy metals and organic pollutants, thus reducing their bioavailability. Industrially, they are extracted from non-re
Publicado em: 2005
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12. "Fabricação e avaliação de microdispositivos para eletroforese com detecção eletroquímica" / "Fabrication and Evaluation of Electrophoresis Microdevices coupled with Electrochemical Detection"
This work describes the development of electrophoresis microchip fabricated by direct-printing and photolithographic processes. The channel structures of the devices fabricated by direct-printing process are defined by polyester films (base and cover) and by a toner layer (walls). The characterization of toner surface and composition were necessary for a bet
Publicado em: 2004