نتایج جستجو برای: sulphide minerals
تعداد نتایج: 25221 فیلتر نتایج به سال:
The majority of global petroleum is in the form of highly viscous heavy oil. Traditionally heavy oil in sands at shallow depths is accessed by large scale mining activities. Recently steam has been used to allow heavy oil extraction with greatly reduced surface disturbance. However, in situ thermal recovery processes can generate hydrogen sulphide, high levels of which are toxic to humans and c...
Zoothamnium niveum (Ciliophora, Oligohymenophora) is a giant, colonial marine ciliate from sulphide-rich, shallow-water habitats, obligatorily associated with the ectosymbiotic, chemoautotrophic, sulphide-oxidizing bacterium 'Candidatus Thiobios zoothamnicoli'. The aims of this study were to characterize the natural habitat and investigate growth, reproduction, survival and maintenance of the s...
1. The metabolism of diallyl disulphide was investigated in vitro with rat and human liver cell subfractions and ex vivo with an isolated perfused rat liver. 2. Diallyl disulphide was oxidized to diallylthiosulphinate by rat liver microsomes with an apparent K(m) = 0.86 +/- 0.1 mM and an apparent V(max) = 0.47 +/- 0.12 nmol min(-1) mg(-1) protein (mean +/- SE). Both cytochrome P450 (CYP) and fl...
In this study, grinding + flotation experiments were performed on the sample of complex Pb-Zn sulphide ore taken from Niğde (Ulukışla-Madenköy) region in Turkey. According to mineralogical analysis used experimental studies, it was determined that composition contains calcite, quartz, pyrite, chalcopyrite, hematite, goethite, limonite, gypsum, galena, sphalerite, jarosite, arsenopyrite and marc...
found around East-Pacific Rise hydrothermal vents is the giant tube-worm Riftia pachyptila Jones, 1981. This “autotrophic” animal is devoid of a digestive system and acquires metabolic energy from the oxidation of sulphide by chemolithoautotrophic bacteria that live symbiotically inside a specific, highly vascularized organ, the trophosome. Therefore, blood transport nutrients is a crucial issu...
The Muteh gold district is located about 70 km northeast of Golpaygan within Sanandaj-Sirjan metamorphic zone of Zagros Structural Belt. Geological studies show that the area had been under poly - phase metamorphism. Gold mineralization occurs in metamorphic complex which consists mainly of green schists, meta-volcanics, and gneisses. Shear zones are the host of gold mineralization, and intense...
Diamond-reinforced zinc sulphide composites have increased toughness as compared to that of pure zinc sulphide. While the mechanical properties of the composites are relatively insensitive to green state processing, the optical properties are greatly affected by the processing which governs the quality of diamond dispersion. Improved dispersion and hence good optical transmission have been achi...
A study was carried out to assess possible effects of low concentrations of hydrogen sulphide on respiratory function. The cohort comprised 26 male pulp mill workers (mean age 40.3, range 22-60 years) with a daily exposure to hydrogen sulphide in the workplace, and 10 volunteers, who had asthma (three men, mean age 40.7, range 33 to 50 years, and seven women, mean age 44.1, range 31 to 61 years...
Flow Injection Spectrophotometric Determination of Sulphide by Catalytic Reduction of Toluidine Blue
Sulphide was determined spectrophotometrically at 628 nm and pH 6.7 based on its catalytic reduction of toluidine blue in the presence of Se(IV) using a flow injection system. After optimization of the measuring conditions the calibration curve was found linear up to 25 mg/mL and the detection limit was 0.3 mg/mL (30 mL injections). The ...
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