Consulta: creatorFacets:"Batista,Marcelo Augusto"
Registros recuperados: 8
Data/hora: 09/06/2024 12:19:54

Thermal Transformation and Characterization of Synthetic Al-Substituted Maghemites (γ-Fe2-xAlxO3)
Provedor de dados: 90
Autores: Nonaka,Adriele Galeti; Batista,Marcelo Augusto; Inoue,Tadeu Takeyoshi; Costa,Antonio Carlos Saraiva da.
ABSTRACT Burning is a common practice in tropical areas and related changes in mineralogy might affect the chemical and physical behavior of soils. Maghemite is a common iron oxide in soils formed from basic rocks in tropical regions. This mineral and hematite are the main pigments in these soils and exhibit high magnetization stemming from the precursor magnetite formed during the weathering process of primary minerals. The objective of the present study was to analyze changes in color, magnetic suceptibility values, Fourier transform infrared spectroscopy (FTIR) spectra, and available Fe and Al contents extracted with 1 mol L-1 KCl during the process of thermal transformation of synthetic Al-maghemites into Al-hematites. Synthetic substituted maghemites...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Fourier Transform Infrared Spectroscopy; Color; Mass Specific Magnetic Susceptibility; KCl.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832016000100427

Structural and magnetic characterization of maghemites prepared from Al-substituted magnetites
Provedor de dados: 90
Autores: Batista,Marcelo Augusto; Costa,Antonio Carlos Saraiva da; Bigham,Jerry Marshal; Paesano Junior,Andrea; Berndt,Graciele; Inoue,Tadeu Takeyoshi; Nonaka,Adriele Galeti.
Synthetic aluminum-substituted maghemites were characterized by total chemical analysis, powder X-ray diffraction (XRD), Mössbauer spectroscopy (ME), and vibrating sample magnetometry (VSM). The aim was to determine the structural, magnetic, and hyperfine properties of γ-Fe2-xAl xO3 as the Al concentration is varied. The XRD results of the synthetic products were indexed exclusively as maghemite. Increasing Al for Fe substitution decreased the mean crystalline dimension and shifted all diffraction peaks to higher º2θ angles. The a0 dimension of the cubic unit cell decreased with increasing Al according to the equation a o = 0.8385 - 3.63 x 10-5 Al (R²= 0.94). Most Mössbauer spectra were composed of one sextet, but at the highest substitution rate of 142.5...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Isomorphous substitution; Hyperfine parameters; Spinel; Ferromagnetic.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832013000600013

Kinetics of Thermal Transformation of Synthetic Al-Maghemites into Al-Hematites
Provedor de dados: 90
Autores: Nonaka,Adriele Galeti; Batista,Marcelo Augusto; Costa,Antonio Carlos Saraiva da; Inoue,Tadeu Takeyoshi; Bonadio,Taiana Gabriela Moretti; Souza Junior,Ivan Granemann de.
ABSTRACT Maghemite (γ-Fe2O3) and hematite (α-Fe2O3) are important iron oxides in Brazilian soils derived from basalt. Maghemite can transform into hematite when exposed to high temperatures. However, isomorphic substitution (e.g., Al3+) may largely influence this process. We analyzed the kinetics of thermal transformation of Al-maghemites into Al-hematites and some of its mineralogical aspects. Synthetic substituted maghemites with different degrees of Al-substitution (0.0, 1.0, 2.0, 2.9, 3.8, 5.6, 6.7, 10.0, 12.0, and 17.1 mol% Al) were subjected to a temperature of 500±10 °C for 0, 5, 10, 16, 64, 128, 192, 360, 720, 2160, 3600, 5040, and 6480 min. After thermal treatment, samples were characterized by X ray diffraction (XRD), differential thermal...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Rietveld refinement; Thermal treatment; Mean crystallite dimension.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832017000100410

Aluminum in corn plants: influence on growth and morpho-anatomy of root and leaf
Provedor de dados: 90
Autores: Batista,Michelli Fernandes; Moscheta,Ismar Sebastião; Bonato,Carlos Moacir; Batista,Marcelo Augusto; Almeida,Odair José Garcia de; Inoue,Tadeu Takeyoshi.
Aluminum (Al) toxicity is one of the most limiting factors for productivity. This research was carried out to assess the influence of Al nutrient solution on plant height, dry weight and morphoanatomical alterations in corn (Zea mays L.) roots and leaves. The experiment was conducted in a greenhouse with five treatments consisting of Al doses (0, 25, 75, 150, and 300 µmol L-1) and six replications. The solutions were constantly aerated, and the pH was initially adjusted to 4.3. The shoot dry matter, root dry matter and plant height decreased significantly with increasing Al concentrations. Compared to the control plants, it was observed that the root growth of corn plants in Al solutions was inhibited, there were fewer lateral roots and the development of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Dry matter production; Height; Toxicity; Zea mays L.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832013000100018

Atributos físicos e carbono orgânico em latossolo vermelho sob diferentes sistemas de uso e manejo
Provedor de dados: 90
Autores: Viana,Eduardo Torres; Batista,Marcelo Augusto; Tormena,Cássio Antonio; Costa,Antonio Carlos Saraiva da; Inoue,Tadeu Takeyshi.
A compreensão e a quantificação do impacto dos sistemas de uso e manejo nos teores de C orgânico do solo (COS) e em propriedades físicas são fundamentais para o desenvolvimento de sistemas agrícolas sustentáveis. O objetivo deste trabalho foi avaliar alterações em alguns atributos físicos e COS de um Latossolo Vermelho da região noroeste do Paraná sob diferentes sistemas de uso e manejo: mata nativa, pastagem e as culturas de mandioca e de cana-de-açúcar. Foram coletadas amostras deformadas para determinação da textura, da densidade de partículas, do ensaio de Proctor normal e dos teores de matéria orgânica; e amostras indeformadas, para determinação da densidade do solo (Ds) e porosidade do solo. Os resultados indicaram que os sistemas de manejo estudados...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ensaio de Proctor; Porosidade; Densidade do solo; Degradação do solo.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832011000600025

Cristallochemical characterization of synthetic Zn-substituted maghemites (g-Fe2-xZn xO3)
Provedor de dados: 90
Autores: Batista,Marcelo Augusto; Costa,Antonio Carlos Saraiva da; Souza Junior,Ivan Granemann de; Bigham,Jerry Marshal.
Maghemite (g-Fe2O3) is the most usually found ferrimagnetic oxide in red basalt-derived soils. The variable degrees of ionic substitution of Fe3+ for different metals (e.g. Ti4+, Al3+, Mg2+, Zn2+, and Mn2+) and non-metals in the maghemite structure influence some cristallochemical features of this iron oxide. In this study, synthetic Zn-substituted maghemites were prepared by co-precipitation in alkaline aqueous media of FeSO4.7H2O with increasing amounts of ZnSO4.7H2O to obtain the following sequence of Fe3+ for Zn2+ substitutions: 0.0, 0.025, 0.05, 0.10, 0.15, 0.20, and 0.30 mol mol-1. The objective of this work was to evaluate the cristallochemical alterations of synthetic Zn-substituted maghemites. The dark black synthetic precipitated material was...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Iron oxides; X ray diffraction; Mass-specific magnetic susceptibility; Specific surface area; Isomorphic substitution.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832008000200011

Biometric Responses of Soybean to Different Potassium Fertilization Management Practices in Years with High and Low Precipitation
Provedor de dados: 90
Autores: Esper Neto,Michel; Minato,Evandro Antonio; Besen,Marcos Renan; Inoue,Tadeu Takeyoshi; Batista,Marcelo Augusto.
ABSTRACT Brazilian soybean producers commonly apply maintenance potassium (K) fertilization during cultivation to restore the K taken up by plants; however, this measure can modify the morphophysiological plant characteristics, since the functions of K are closely related with plant growth and development. This study assessed the morphological changes in soybean plants in response to K rates, sowing fertilization, and the application periods of K fertilization in a Latossolo Vermelho eutroférrico (Oxisol) under a no-tillage system, located in the municipality of Floresta, Paraná. A randomized block design was used in the experiment with four replications in a fully crossed factorial design (5 × 2 × 2). The experiment was carried out in two growing seasons...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Leaf area index; Correlation; Yield; Drought.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832018000100525

Mineral composition and dry mass production of the corn plants in response to phosphorus sources and aluminum concentration
Provedor de dados: 52
Autores: Batista,Marcelo Augusto; Pintro,José Carlos; Costa,Antonio Carlos Saraiva da; Tormena,Cássio Antonio; Bonato,Carlos Moacir; Batista,Michelli Fernandes.
The corn plants were evaluated with different phosphate fertilizer sources and aluminum (Al) concentrations in a sandy substrate. A totally randomized experiment design was set up with two corn plants in the pots containing 2 kg of a sandy substrate, two phosphate sources (Triple Super Phosphate - TSP or Arad Phosphate - AP) and four Al concentrations. When Al concentrations increased, pH (CaCl2) substrate values decreased. There was an increase in the calcium and phosphorus contents in the sandy substrates that received the TSP and AP sources. The calcium, magnesium, phosphorus, and potassium concentrations of the corn plant's shoot were higher in the TSP than without P and AP sources. When the Al concentration increased, the concentration values of the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Zea mays; Phosphate fertilizers; Solubility; Toxicity.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132009000300004