We examined the effects of hypoxia and sulphide levels on the ventilatory activity of Arenicola marina and determined whether ventilation compensates for oxygen deficiency and affects the mode of energy provision. A. marina ventilated intermittently, irrespective of ambient P(O2) and sulphide concentration. The ventilation rate was 28.5+/-16 ml h(-1) g(-1) wet mass during normoxia, but increase...

The product of the biological sulphate reduction is sulphide. High concentrations of molecular H2S (g) can be inhibitory for microbial activity, especially at a reactor pH of 6 to 7. This paper focuses on the effect of high sulphide concentrations on the sulphate reduction rates. The results of three investigations operating a continuous reactor, a column reactor and batchtest reactors have sho...

The lead–zinc ore is a typical low-grade complex polymetallic sulphide ore. Its mineralogy characterized by high content of cryptocrystalline graphite, low lead, zinc, and copper, fine grain size. However, the aggregation size sulfide mineral aggregations coarse, symbiotic relationship relatively simple. Conventional process treatment requires grinding into monomer dissociations followed prefer...

The structures of human carbonic-anhydrase-II complexes with the anionic inhibitors hydrogen sulphide (HS-) and nitrate (NO3-) have been determined by X-ray diffraction at 0.19-nm resolution from crystals soaked at pH 7.8 and 6.0, respectively. The modes of binding of these two anions differ markedly from each other. The strong inhibitor HS- replaces the native zinc-bound water/hydroxide (Wat26...

AIM Hydrogen sulphide (H2S) intoxication in man is frequently associated with a fatal outcome. In small animal models hydrogen sulphide has demonstrated profound protection against hypoxia. No reports that focus on a potential protective effect in humans have been published. METHODS The frequency and outcome of a large cohort of hydrogen sulphide intoxications is described. RESULTS From 198...

at the present time, flotation is the primary method for copper minerals separation from copper ores. the main copper ores that is extracted in the world is sulphide ore. the sulphide minerals are floated readily by using sulphydryl collectors. in the case of using xanthates , which are among the sulphydryl collectors, used more in the flotation of sulphide minerals of copper, the flotation of ...

Germanium/Zinc Sulphide (Ge/ZnS) single and multilayers are deposited by ion assisted electron beam deposition on Silicon substrates for applications in the 2-15 µm wavelength region. Refractive indices of Ge ZnS thin films extracted from measured reflectance transmittance spectra. Several types mid-infrared filters (high-, anti-reflection coatings dichroic filters) with a number layers ranging...