The magnitude and temperature-sensitivity of oxygen isotope fractionation in ferric oxide-water systems remain uncertain. In this study, three different synthetic methods are used to investigate the temperature dependence of the fractionation between water and hematite, akaganeite, and goethite at near-surface temperatures. Our results reveal two similarities among these ferric oxide-water syst...

Nanoparticulate composites of hydroxyapatite (HAp) and chitosan were synthesized by ultrasound-assisted sequential precipitation and characterized for their microstructure at the atomic scale, surface charge, drug release properties, and combined antibacterial and osteogenic response. Crystallinity of HAp nanoparticles was reduced because of the interference of the surface layers of chitosan wi...

Our study of the Seti River in far western Nepal shows that the solute chemistry of the river and its tributaries is strongly controlled by geology. The Seti flows through four distinct terranes, starting with the Tethyan sedimentary series (TSS) and Greater Himalayan series (GHS). TSS/GHS waters display Sr/Sr ratios of ,0.73 and high Sr and Ca, consistent with the composition of limestone and ...

The self-assembly of uniform single-crystalline microrods of organic dye Sudan II (1-(2,4- dimethylphenyl-azo)-2-naphthol) in solution was achieved by reprecipitation with the assistance of amphiphilic block copolymer Pluronic F127. It was found that the formation of F127 micelles was favorable for the production of uniform Sudan II microrods whereas individual F127 molecules favored the format...

Young basalts from Kilauea Volcano, Hawai'i, frequently feature opaque surface coatings, 1–80 μm thick, composed of amorphous silica and Fe-Ti oxides. These coatings are the product of interaction of the basaltic surface with volcanically-derived acidic fluids. Previous workers have identified these coatings in a variety of contexts on Hawai'i, but the timescales of coating development, coating...

BACKGROUND Calcium phosphate manufactured samples, prepared with hydroxyapatite, are used as either spacers or fillers in orthopedic surgery, but these implants have never been used under conditions of mechanical stress. Similar conditions also apply with cements. Many authors have postulated that cements are a useful substitute material when implanted in vivo. The aim of this research is to de...

The reprecipitation mechanisms and kinetics of γ' particles during cooling from supersolvus and subsolvus temperatures were studied in AD730(TM) Ni-based superalloy using Differential Thermal Analysis (DTA). The evolution in the morphology and distribution of reprecipitated γ' particles was investigated using Field Emission Gun Scanning Electron Microscopy (FEG-SEM). Depending on the cooling ra...

Experimental studies were conducted to identify the physical and chemical features of gold’s behaviour in hydrothermal processes linked ore formation involving CO2 oxidized deposits. With aid autoclave method, a temperature range between 200 400 °C, isochoric dependences PVT parameters concentrated sulphate chloride fluids plotted, both presence absence CO2. Our experiments established that sul...