Sulfur speciation was determined in real time in salt marsh microbial mats, subtidal sediments and hydrothermal vent diffuse flow waters using solid state gold-amalgam voltammetric microelectrodes. Chemical species were measured in situ without any sample manipulation or processing. The partially oxidized sulfur species detected were polysulfides, thiosulfate, elemental sulfur and tetrathionate...

This paper presents a focused review on the nanomaterials and associated transduction schemes that have been developed for the selective detection of hydrogen sulfide. It presents a quite comprehensive overview of the latest developments, briefly discusses the hydrogen sulfide detection mechanisms, identifying the reasons for the selectivity (or lack of) observed experimentally. It critically r...

The ability of streptomycetes to produce hydrogen sulfide is generally used for taxonomic purposes. It was found that the previously used method, the blackening of Peptone Iron Agar, does not clearly indicate formation of hydrogen sulfide. It was shown that the blackening of a lead acetate strip is the most accurate indicator for H(2)S-producing streptomycetes. A great variety of organic and in...

Nitric oxide (NO) and hydrogen sulfide (H2S) pathways are involved in the development of hypertension, a condition that can originate from early life. We examined whether asymmetric dimethylarginine (ADMA, a nitric oxide synthase inhibitor)/NO and H2S generating pathway contributed to programmed hypertension in offspring exposed to prenatal dexamethasone (DEX) and postnatal high-fat (HF) and wh...

In this study, turbulent compressible gas flow in a rectangular micro-channel is numerically investigated. The gas flow assumed to be in the subsonic regime up to Mach number about 0.7. Five low and high Reynolds number RANS turbulence models are used for modeling the turbulent flow. Two types of mesh are generated depending on the employed turbulence model. The computations are performed for R...

We have developed a novel colorimetric and ratiometric fluorescence probe for the selective and sensitive monitoring of hydrogen sulfide based on a dicyanoisophorone platform. An excellent linear relationship of fluorescence intensity ratio (I637/I558) (R(2) = 0.9867) versus hydrogen sulfide concentration in the range of 1-12 μM was obtained. This probe exhibited a remarkable fluorescence respo...

Membrane-based pervaporation (PV) has attracted much attention in the dehydration of organic solvents. Permeate pressure and feed flow rate are two important parameters, which affect membrane performance in pervaporation. The effects of these two parameters on the performance of a commercial poly (vinyl alcohol) membrane in the dehydration of benzene have been investigated in this work. The exp...

in the present work, a titanium-based ziegler-natta catalyst was employed to synthesize ultra molecular weight polyethylene in a slurry medium. the effect of different parameters such as ethylene pressure, temperature, catalyst composition, and hydrogen pressure was studied. as the results indicate, increasing either [al]/[ti] ratio or temperature causes polymerization rate to go through a maxi...