in this work, a bench-scale process was developed using mineral-processing methods to recover iron from a placer deposit located in bardaskan, khorasan-e-razavi, iran. the mineralogical studies were performed by x-ray diffraction (xrd), x-ray fluorescence (xrf), electron probe micro-analyzer (epma), and an optical microscope. these studies indicated that titanomagnetite, magnetite, and hematite...

[1] The global chemical transport model GEOS‐Chem, implemented with a dust‐iron dissolution scheme, was used to analyze the magnitude and spatial distribution of mineral dust and soluble‐iron (sol‐Fe) deposition to the South Atlantic Ocean (SAO). The comparison of model results with remotely sensed data shows that GEOS‐Chem can capture dust source regions in Patagonia and characterize the tempo...

The biomineralization of several magnetic iron minerals, including the iron oxide magnetite (Fe30 4 ; Fe 2I Fe/+04 ) and the iron sulfides greigite (Fe3S4 ) and pyrrhotite (Fe7SS)' can be mediated by bacteria as well as by other organisms. These minerals are known to be synthesized by procaryotes in one of two fundamentally different modes of biomineralization. The first is uncontrolled mineral...

The mineral compositions of the 8 wild edible fruits were investigated. Nitrogen, sodium, potassium, calcium, magnesium and phosphorus were analyzed as the major constituents of the fruits and iron, zinc, copper and manganese were identified as a minor constituent. Among all the mineral, Potassium were found in large quantity in all fruits. Ficus racemosa L., fruit contain the highest amount of...

Magnetotactic bacteria have evolved complex subcellular machinery to construct linear chains of magnetite nanocrystals that allow the host cell to sense direction. Each mixed-valent iron nanoparticle is mineralized from soluble iron within a membrane-encapsulated vesicle termed the magnetosome, which serves as a specialized compartment that regulates the iron, redox, and pH environment of the g...

Ferritin concentrates, stores, and detoxifies iron in most organisms. The iron is a solid, ferric oxide mineral (< or =4500 Fe) inside the protein shell. Eight pores are formed by subunit trimers of the 24 subunit protein. A role for the protein in controlling reduction and dissolution of the iron mineral was suggested in preliminary experiments [Takagi et al. (1998) J. Biol. Chem. 273, 18685-1...

Some bacteria utilize (semi)conductive iron-oxide minerals as conduits for extracellular electron transfer (EET) to distant, insoluble electron acceptors. A previous study demonstrated that microbe/mineral conductive networks are constructed in soil ecosystems, in which Geobacter spp. share dominant populations. In order to examine how (semi)conductive iron-oxide minerals affect EET paths of Ge...

PURPOSE In the human brain, minerals such as iron and calcium accumulate increasingly with age. They typically appear hypointense on T2*-weighted MRI sequences. This study aims to explore the differentiation and association between calcified regions and noncalcified iron deposits on clinical brain MRI in elderly, otherwise healthy subjects. MATERIALS AND METHODS Mineral deposits were segmente...

Environmental mineral particles such as asbestos are responsible for numerous respiratory diseases. In addition to effects related to their geometry, particles are now assumed to act by triggering an oxidative stress process. Iron-containing particles, in particular, can produce oxygen-activated species by oxidizing their iron. To evaluate the involvement of iron-containing particles in respira...