The Lemoine tailings of Chibougamau, Quebec, Canada, were deposited as a pH-neutral mineral conglomerate consisting of aluminum-silicates, iron-aluminum-silicates, pyrite, chalcopyrite, and sphalerite. These tailings are colonized by an active population of Thiobacillus ferrooxidans which is localized to an acid zone occupying 40% of the tailings' surface. This population peaked at 7 x 10 most ...

Abstract During flight, many silicates (sand, dust, debris, fly ash, etc.) are ingested by an engine. They melt at high operating temperatures on the surface of thermal barrier coatings (TBCs) to form calcium-magnesium-aluminum-silicate (CMAS) amorphous settling. CMAS corrodes TBCs and causes problems, such as composition segregation, degradation, cracking, disbanding. As a new generation TBC c...

In the present study, several pre-polymerized coagulants of iron and aluminum were tested for their efficiency towards As(V) and As(III) removal from water sources. The results showed that the pre-polymerized coagulants of iron, such as poly-ferric sulfate and poly-ferric silicate chloride, were very efficient for As(V) removal. With regard to As(III) removal, among all examined coagulants, inc...

Selective catalysts for sustainable production of fuels and commodity chemicals are important due to the abundance of the raw materials in the nature. Most of these reactions require multiple active sites due to the complexity of the reactions involved. In view of this, we have synthesized a multifunctional catalyst for the selective synthesis of C4 hydrocarbons from ethanol. The reason for sel...

The photodarkening phenomenon in alumino-silicate glass preforms, doped with different ytterbium concentrations, was studied. The UV band, comprised between 180 and 350 nm, was examined before and after irradiation at 976 nm. The non-linear dependence of 240 nm band with concentration after infra-red irradiation was demonstrated and ascribed predominantly to Yb 3+ pair’s interaction. The emissi...

Mineralogy, microbial ecology, and mineral weathering in the subsurface are an intimately linked biogeochemical system. Although bacteria have been implicated indirectly in the accelerated weathering of minerals, it is not clear if this interaction is simply the coincidental result of microbial metabolism, or if it represents a speciŽ c strategy offering the colonizing bacteria a competitive ec...

High precision oxygen three-isotope ratios were measured for four mineral phases (olivine, low-Ca and high-Ca pyroxene, and plagioclase) in equilibrated ordinary chondrites (EOC) using a secondary ion mass spectrometer. Eleven EOCs were studied that cover all groups (H, L, LL) and petrologic types (4, 5, 6), including S1-S4 shock stages, as well as unbrecciated and brecciated meteorites. SIMS a...

[1] The electronic spin and valence states of Fe in post‐ perovskite ((Mg0.75Fe0.25)SiO3) have been investigated by synchrotron X‐ray diffraction, Mössbauer and X‐ray emission spectroscopy at 142 GPa and 300 K. Rietveld refinement of the X‐ray diffraction patterns revealed that our sample was dominated by CaIrO3‐type post‐perovskite. Combined Mössbauer and X‐ray emission results show that Fe in...