Weathering products of two fragments of Dronino iron ungrouped meteorite found in the wet and drier clay sand were studied using X-ray diffraction and Mössbauer spectroscopy with a high velocity resolution. The products of metal oxidation in the internal and external surface layers were different for both fragments. The weathering products in fragment found in the wet clay sand contain magnetit...

The influence of prolonged ball milling on structural changes of hexagonal and spinel type complex iron oxides has been studied by x-ray diffraction and high resolution electron microscopy. The XRD and HREM results for ball milled SrFel2Olg ferrite show fast decomposition and formation of Fe203 and SrO simple oxides. Microstructural developments for a powder mixture of Co(OH)2 and Fe203 show th...

Fe/Zn oxides promoted with K and Cu selectively produce a-olefins at typical FischerTropsch synthesis conditions (2/1 H2/CO, 1 MPa, and 270°C). The simultaneous presence of K and Cu introduces a synergistic activity enhancement while maintaining the high oletrm selectivity obtained by alkali promotion. Structural and morphological differences in Fe-Zn oxides prepared from ammonium glycolate com...

Arsenic bioaccessibility varies with in vitro methods and soils. Four assays including unified BARGE method (UBM), Solubility Bioaccessibility Research Consortium method (SBRC), in vitro gastrointestinal method (IVG), and physiologically based extraction test (PBET), were used to determine As bioaccessibility in 11 contaminated soils (22-4,172 mg kg(-1)). The objective was to understand how bio...

Oxygen coordination of transition metals is a key for functional properties of transition-metal oxides, because hybridization of transition-metal d and oxygen p orbitals determines correlations between charges, spins and lattices. Strain often modifies the oxygen coordination environment and affects such correlations in the oxides, resulting in the emergence of unusual properties and, in some c...

-Selected Brazilian Oxisols were sampled and submitted to high-gradient magnetic separation (HGMS) to study the iron oxide-clay mineral associations. The soils, derived from four different parent materials, have mineralogy dominated mostly by hematite, goethite, and kaolinite. Gibbsite appears in most soil samples. The high-gradient magnetic separation showed good separation for some soils, as ...

Soil soluble nickel (Ni) concentration is very important for determining soil Ni toxicity. In the present study, the relationships between soil properties, total and soluble Ni concentrations in soils were developed in a wide range of soils with different properties and climate characteristics. The multiple regressions showed that soil pH and total soil Ni concentrations were the most significa...

Abstract In this work, we investigate alternative materials systems that, based on their intrinsic magnetic properties, have the potential to deliver enhanced heating power in fluid hyperthermia. The focus lies with high magnetization phases, namely iron-nitrogen (Fe-N), iron-boron (Fe-B) and iron-carbon (Fe-C) compounds, performance comparison conventionally used iron oxides, γ -Fe 2 O 3 , Fe ...