The precipitation of chromium(III), copper(II), manganese(II) and zinc(II) by biogenic hydrogen sulfide generated by sulfate-reducing bacteria, Desulfovibrio sp., and the degradation of total petroleum hydrocarbons (TPH) in the presence of heavy metal by Pseudomonas aeruginosa AT18 have been carried out. An anaerobic stirred tank reactor was used to generate hydrogen sulfide with Desulfovibrio ...

The very thin native oxide film on stainless steel, of the order of 2 nm, is known to be readily modified by immersion in aqueous media. In this paper, XPS and ToF-SIMS are employed to investigate the nature of the air-formed film and modification after water emmersion. The film is described in terms of oxide, hydroxide and water content. The preferential dissolution of iron is shown to occur o...

The effect of 5 different surface conditioning methods on bonding of metal brackets to cast dental alloys was examined. The surface conditioning methods were fine (30-microm) or rough (125-microm) diamond bur, sandblasting (50-microm or 110-microm aluminum oxide [Al2O3]), and silica coating (30-microm silica). Fifty disc-shaped specimens of 5 different alloys (gold-silver, palladium-silver, nic...

High operating temperatures can have very deleterious effects on the long-term performance of high-Cr, creep-resistant steels used, for example, in the structural components of power plants. For the popular creep-resistant steel X20CrMoV12.1 we analysed the processes of carbide growth using a variety of analytical techniques: transmission electron microscopy (TEM) and diffraction (TED), scannin...

In connection with the production of 46.2 min Mn via the Cr(d, n)-process, several separation techniques such as ion exchange chromatography, solid phase extraction, liquid–liquid extraction and co-precipitation have been investigated; the aim was to separate no-carrier-added radiomanganese from the bulk target chromium. Among the separation systems ∗MnII/CrIII , ∗MnII/CrVI and ∗MnIV/CrVI, the ...

deep cryogenic heat treatment is assumed as a supplementary heat treatment performed on steels before the finaltempering treatment to enhance the wear resistance and hardness of the steels. in this study, the effects of thedeep cryogenic heat treatment on the wear behavior and corrosion resistance of the 1.2080 tool steel were studiedusing the wear testing machine and polarization and impedance...

Morphological and chemical characteristics were determined for airborne tungsten particles in Fallon, Nevada, a town that is distinguishable environmentally by elevated airborne tungsten and cobalt. From samples of airborne dust collected previously at six different places in Fallon, tungsten-rich dust particles were isolated and analyzed with automated electron microprobe and wavelength-disper...