Iron Oxides
Mostrando 25-36 de 151 artigos, teses e dissertações.
-
25. Chemical-Mineralogical Characterization of Magnetic Materials from Magnetic Soils of the Southern Espinhaço Mountain Chain and of the Upper Jequitinhonha Valley, State of Minas Gerais, Brazil
ABSTRACT In the Southern Espinhaço Mountain Chain and in the Upper Jequitinhonha Valley, magnetic soils, in different pedogenetic stages, are found to be forming over intrusions of basic lithology. The essential chemical and mineralogical properties of samples from magnetic soil profiles from those two physiographic environments in the state of Minas Gerais
Rev. Bras. Ciênc. Solo. Publicado em: 27/03/2017
-
26. Modelling of Lead Migration from Electronic Waste to Mixtures of Kaolinite, Iron Oxides and Organic Matter
Improper disposal of electronic waste in the environment facilitates migration of heavy metals, especially lead, into the soil and can contribute to the bioavailability of this species. Based on a simplex-centroid mixture experimental design, small-scale tests were performed for incubation of printed circuit boards (PCBs) in mixtures containing organic matte
J. Braz. Chem. Soc.. Publicado em: 2016-05
-
27. Assessment of sugarcane harvesting residue effects on soil spectral behavior
ABSTRACT When the harvesting of sugarcane involves a mechanized process, plant residues remain on the soil surface, which makes proximal and remote sensing difficult to monitor. This study aimed to evaluate, under laboratory conditions, differences in the soil spectral behavior of surface layers Quartzipsamment and Hapludox soil classes due to increasing lev
Sci. agric. (Piracicaba, Braz.). Publicado em: 2016-04
-
28. Synthesis, Characterization and Applications of Iron Oxide Nanoparticles - a Short Review
ABSTRACT: Iron oxide is a mineral compound that shows different polymorphic forms, including hematite (α-Fe2O3), magnetite (Fe3O4) and maghemite (γ-Fe2O3). Solid propulsion technology nanoparticulate materials, such as hematite and maghemite, exhibit high performance on thermal decomposition of ammonium perchlorate. The enhanced catalytic effect of metalli
J. Aerosp. Technol. Manag.. Publicado em: 2015-09
-
29. Surfactant-Assisted Preparation of FeCu Catalyst for Fischer-Tropsch Synthesis
FeCu catalysts were prepared by co-precipitation method with or without the assistance of the surfactant, polyvinyl pyrrolidone (PVP), polyvinyl alcohol (PVA) or polyethylene glycol (PEG). The effect of surfactant on the structure and catalytic behavior of FeCu catalysts was investigated. The catalysts were characterized by inductively coupled plasma (ICP
J. Braz. Chem. Soc.. Publicado em: 2015-07
-
30. APLICAÇÃO DE ÓXIDOS DE FERRO NANOESTRUTURADOS COMO ADSORVENTES E FOTOCATALISADORES NA REMOÇÃO DE POLUENTES DE ÁGUAS RESIDUAIS
New techniques for treating wastewater, particularly the removal or degradation of organic pollutants and heavy metals, among other pollutants, have been extensively studied. The use of nanostructured iron oxides as adsorbent and photocatalyst for the removal of these contaminants has proved a promising approach, not only because of their high treatment effi
Quím. Nova. Publicado em: 2015-03
-
31. VIS-NIR SPECTROMETRY, SOIL PHOSPHATE EXTRACTION METHODS AND INTERACTIONS OF SOIL ATTRIBUTES
The objective of this study was to evaluate the relationships between the spectra in the Vis-NIR range and the soil P concentrations obtained from the PM and Prem extraction methods as well as the effects of these relationships on the construction of models predicting P concentration in Oxisols. Soil samples' spectra and their PM and Prem extraction solution
Quím. Nova. Publicado em: 2015-03
-
32. Field-scale spatial correlation between contents of iron oxides and CO2 emission in an Oxisol cultivated with sugarcane
Soil CO2 emission (FCO2) is one of the main sources of carbon release into the atmosphere. Moreover, FCO2 is related to soil attributes governing the transfer of gases from soil to the atmosphere. This study aimed firstly to describe the spatial variability of hematite (Hm), goethite (Gt), iron extracted with sodium dithionite-citrate-bicarbonate (Fed) conte
Sci. agric. (Piracicaba, Braz.). Publicado em: 2015-02
-
33. Feasibility of RF Sputtering and PIIID for production of thin films from red mud
During the extraction of aluminum from bauxite, a waste of oxides containing traces of heavy metals in a highly alkaline matrix, called Red Mud (RM), is produced. In this study RM is characterized and the feasibility of using it as a precursor for the production of thin films by Plasma Sputtering and by Plasma Immersion Ion Implantation and Deposition (PIIID
Mat. Res.. Publicado em: 26/10/2014
-
34. Pulsed dc discharge in the presence of active screen for nitriding of high carbon steel
A discharge of nitrogen - hydrogen mixture by 50 Hz pulsed dc in the presence of active screen cage is investigated by optical emission spectroscopy (OES). The aim is to identify the parameters (mixture ratio, filling pressure and current density) that may lead to high concentration of active species (N2, N2+ and N). The maximum concentration in this experim
Mat. Res.. Publicado em: 22/07/2014
-
35. Clay mineralogy and magnetic susceptibility of Oxisols in geomorphic surfaces
Studies analyzing the variability of clay minerals and magnetic susceptibility provide data for the delineation of site-specific management areas since many of their attributes are important to agronomy and the environment. This study aimed to evaluate the spatial variability of clay minerals, magnetic susceptibility, adsorbed phosphorus and physical attribu
Sci. agric. (Piracicaba, Braz.). Publicado em: 2014-06
-
36. Conversão química de no e co sobre catalisadores à base de óxidos de cobalto ou de ferro
Cobalt or iron oxides supported or not on zeolite Hbeta were prepared and evaluated in the reduction reaction of NO by CO in presence of O2, SO2 or H2O. XRD results evidenced the Hbeta structure and the formation of Co3O4 and Fe2O3. TPR-H2 analysis showed complete reduction of cobalt oxide at lower temperatures than for iron oxide. The catalysts are quite ac
Quím. Nova. Publicado em: 2014-04