Dominant Particles
Mostrando 1-12 de 127 artigos, teses e dissertações.
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1. Phase transformation of kaolinite to hexagonal kalsilite using K2CO3
Abstract Hydrothermal synthesis of kalsilite was facilitated by the inclusion of potassium carbonate (K2CO3) as the source of the potassium ion. After a 24 h reaction at 220 °C, kaolin clay treated with 1.25 M K2CO3 showed the most significant peaks at 2θ of 28.5° and 34.7° by X-ray diffraction corresponding to the hexagonal kalsilite. In addition, field
Cerâmica. Publicado em: 2022
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2. Cation Vacancies in NiFe2O4 During Heat Treatments at High Temperatures: Structural, Morphological and Magnetic Characterization
Nickel ferrite (NiFe2O4) was synthesized by mixing stoichiometric amounts of α-Fe2O3 and NiO using mechanical milling and heat treatments at high temperatures. The physical characterization of the samples was carried out using X-ray diffraction, infrared and Raman spectroscopies, Mössbauer spectrometry, magnetization measurements, scanning electron microsc
Mat. Res.. Publicado em: 20/12/2019
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3. Mineralogy, magnetic susceptibility and geochemistry of Fe-rich Oxisols developed from several parent materials
ABSTRACT: Fe-rich Oxisols on mafic rocks in Brazil generally have high magnetic susceptibility with high contents of some trace elements. These are taxonomically similar soils; however, differences in magnetic and geochemical properties may affect agricultural or environmental usability and subsequent management. This study investigated the pedogenesis of Fe
Sci. agric. (Piracicaba, Braz.). Publicado em: 2018-09
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4. Levantamento dos níveis de radioatividade natural em águas do alto Vale do Ribeira à planície costeira do litoral sul do Estado de São Paulo / Assessment of natural radioctivity levels in waters from Higher Ribeira Valley until the southern Sao Paulo State coastal plain
The complex exchange of fluvial, subsurface and seawater within a coastal area directly affects global biogeochemical cycles and the application of isotopic tracers, mainly natural radionuclides from U and Th series, is a powerful tool to track sources and sinks of trace elements and nutrients to this systems. The unique Ra signature applied to quantify the
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 22/11/2010
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5. Oxidation and erosion-oxidation behavior of steels
The high temperature oxidation and erosion-oxidation (E-O) behavior of steels AISI 1020, 304, 310, and 410 were determined. These steels were selected to evaluate the effect of chromium content on its E-O resistance. The oxidation behavior was determined in a thermogravimetric analyzer. A test rig in which a specimen assembly was rotated through a fluidized
Materials Research. Publicado em: 2008-03
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6. Espectroscopia Mössbauer na caracterização de compostos ferrosos em solos e sua relação com retenção de fósforo
The chemical role of iron-bearing compounds on the dynamics of phosphorus in selected Brazilian latosols was investigated. The iron oxides were characterized in an attempt to assess their main chemical-mineralogical properties influencing the ion sorption mechanisms in those pedosystems. It was found that increasing total iron contents tend to increase the p
Química Nova. Publicado em: 2008
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7. Espectro de excitação para modelos de teorias quânticas de campo na rede: modelos puramente fermiônicos e modelos de cromodinâmica quântica / Excitation spectrum for quantum field theory models on the lattice: pure fermionic models and quantum chromodynamics models
In this thesis, we obtain, from a mathematically rigorous point of view, the low-lying energy-momentum spectrum of two $3+1$ dimensional imaginary time lattice quantum filed theory with fermion fields (we give explicit results for the case $d = 3$ and Dirac matrices): a pure fermionic model with quartic interaction in the $N$-component fermion field and a qu
Publicado em: 2008
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8. A influência das características da areia artificialmente britada nas propriedades do estado fresco do concreto
This work reports on the properties of the fresh state of concrete when different petrografic types of crushed sand are used. It focuses on the characteristics of these aggregates which exert a dominant influence on the concrete properties. To reach the main goal of this work, five different lithological types of crushed sand were used, which have been ident
Publicado em: 2008
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9. Comportamento estratégico dos agentes da cadeia produtiva do peixe na região de Dourados, MS
For the study of the Competitive Advantage of production chain from fish of the Estate of Mato Grosso do Sul, based on studies of Porter (1989) in his book Competitive Advantage Creating and Sustaining Superior Performance, which takes one of the theoretical chain in the strategic area. To create sustainable advantage competitive is the main goal of the orga
Publicado em: 2008
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10. Tratamento das pacientes sintomáticas portadoras de miomas uterinos através da associação das técnicas de embolização dos miomas e ligadura endovascular das artérias uterinas / Uterine artery embolization with polyvinyl-alcohol particles and metallic coils for the treatment of symptomatic patients with fibroids
Uterine fibroids are the most frequent benign tumors of the female genital tract. The tumors are symptomatic in about 30% of the cases, requiring medical treatment. In the present study, a total of 35 clinically symptomatic patients with ultrasonographic diagnosis of fibroids underwent endovascular treatment, which consisted of embolization of the uterine ar
Publicado em: 2007
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11. Controle e monitoramento em tempo real do regime de jorro estavel atraves da analise espectral / Control and monitoring on line of the steady regime in the spouted bed process by spectral analysis
This work describes the control and on line monitoring of the spouted bed steady regime using the gas-solid contact regimes identification method by pressure measurements. The work presents two main features: 1) the on line identification of fluid dynamic regimes in the spouted bed process based in the spectral analysis of the pressure fluctuations and 2) th
Publicado em: 2006
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12. Remote sensing of water circulation dynamic to the Curuai floodplain/Amazon River / Sensoriamento remoto da dinâmica de circulação da água do sistema planície de Curai/Rio Amazonas
In this research it is hypothesized that once water circulation in floodplains is driven by the so called flood-pulse, optical images acquired at different water levels, disregarding hydrological year can be applied to capture time-space variability in water masses types flowing into the Amazon River floodplain. The main objective in this research was to dev
Publicado em: 2005