Bacteria classified in species of the genus Leptothrix produce extracellular, microtubular, Fe-encrusted sheaths. The encrustation has been previously linked to bacterial Fe oxidases, which oxidize Fe(II) to Fe(III) and/or active groups of bacterial exopolymers within sheaths to attract and bind aqueous-phase inorganics. When L. cholodnii SP-6 cells were cultured in media amended with high Fe(I...

Nanoscale Ga particles down to 5 nm were fabricated by an explosion via an in situ electron-beam irradiation on microscale silica-covered Ga balls in a transmission electron microscope. The explosion is confirmed to be a Coulomb explosion because it occurs on the surface rather than in the whole body of the insulating silica-covered Ga micro-balls, and on the pure Ga nano-balls on the edge of c...

Laser interaction with nanoscale particles is distinct and different from laser-bulk material interaction, where a hot plasma is normally created. Here, we review our studies on 193 nm laser ablation of various nanoscale particles including NaCl, soot, polystyrene, and gold. The 20 ns laser beam with fluences up to 0.3 J/cm irradiates nanoparticles in a gas stream at laser repetition rates from...

Several important sediment geochemical factors (particle size, contact time, artificial sediment composition, acid volatile sulfide, and pure inorganic particles coated or uncoated with humic acid) were examined for their influences on the assimilation of Cd, Cr, and Zn in the marine clam Ruditapes philippinarum. Metal desorption and phase speciation were concurrently measured for these particl...

Using scanning tunneling microscopy, we demonstrate that the nucleation density of Fe islands on the surface of nanoscale Pb films oscillates with the film thickness, providing a direct manifestation of the quantum size effect on surface diffusion. The Fe adatom diffusion barriers were derived to be 204+/-5 and 187+/-5 meV on a 21 and 26 monolayer (ML) Pb film, respectively, by matching the kin...

Nanoscale zero-valent iron NZVI particles were synthesized by the aqueous phase borohydride reduction method, and the synthesized NZVI particles were used for the degradation of Basic Yellow 28 BY28 dye in aqueous solution. The influence of experimental variables such as reaction time, NZVI particle dosage and pH were studied on the decolorization of BY28. Mixing an aqueous solution of 100 mg L...

Biochar (BC) supported nanoscale zerovalent iron (nZVI) composite was synthesized and used as an activator for persulfate to enhance the trichloroethylene (TCE) removal in aqueous solutions. The degradation efficiency of TCE (0.15mmolL(-1)) was 99.4% in the presence of nZVI/BC (4.5mmolL(-1), nZVI to BC mass ratio was 1:5) and persulfate (4.5mmolL(-1)) within 5min, which was significantly higher...

Both a Cu-26 wt % Ag (Fe-free) alloy and Cu-26 wt % Ag-0.1 wt % Fe (Fe-doping) alloy were subjected to different heat treatments. We studied the precipitation kinetics of Ag and Cu, microstructure evolution, magnetization, hardness, strength, and electrical resistivity of the two alloys. Fe addition was incapable of changing the precipitation kinetics of Ag and Cu; however, it decreased the siz...

This paper describes the preparation and characterization of a new type of composite nanoparticle, where the structure consists of a nontoxic hydrogel polymer network that encapsulates a gold shell/silica core. These composite nanoparticles are being developed as photothermally responsive drug-delivery vehicles that undergo structural changes slightly above physiological temperature. A unique p...

We report on the characterization of metallurgical phases and their magnetism at the interfaces of nanoscale MgB(2)/Fe layered structures. MgB(2)/(57)Fe multilayers with varying layer thicknesses were prepared by vacuum deposition and investigated, before and after annealing by electrical resistance measurements, x-ray diffraction and (57)Fe conversion-electron Mössbauer spectroscopy (CEMS) dow...