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Containing Sulfur (containing + sulfur)
Selected AbstractsPhosphonates Containing Sulfur and Selenium.CHEMINFORM, Issue 14 2005-Selenenyl, -Seleninyl Moieties, -Sulfenyl, -Sulfinyl, Studies on Nucleophilic Addition., Synthesis of Vinylphosphonates Bearing Abstract For Abstract see ChemInform Abstract in Full Text. [source] The N3+ Reactivity in Ionized Gases Containing Sulfur, Nitrogen, and Carbon OxidesCHEMPHYSCHEM, Issue 10 2006Giulia de Petris Prof. Dr. Abstract The N3+ reactivity with SO2, N2O, CO2, and CO is studied by mass spectrometric techniques under a wide range of pressures from 10,7 to 10,4 Torr. The kinetics, reaction mechanism, and role of vibrationally excited ions are investigated by experimental and theoretical methods. Key distinguishing features of the N3+ reactivity are evidenced by comparison to N+ and N2+ ions, which mainly undergo charge-exchange reactions. The N+ transfer to SO2 prompts formation of NO+ ions and neutral oxides NO and SO. The N+ transfer to N2O also leads to NO+ ions by a process not allowed by spin conservation rules. In both cases no reaction intermediate is detected, whereas CO2 and CO are captured to form the very stable NCO2+ and NCO+ ions. NCO2+ ions are characterized for the first time as strongly bound triplet ions of NOCO and ONCO connectivity. DFT and CCSD(T) computations have been carried out to investigate the structural and energetic features of the NCO2+ species and their formation process. [source] An experimental study on vapor condensation of wet flue gas in a plastic heat exchangerHEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 7 2001L. Jia Abstract An experimental system investigating condensation heat transfer of wet flue gas was set up, and the heat transfer performance of vapor-gas mixture with vapor condensation was discussed. The experimental results of laminar flow in a plastic longitudinal spiral plate heat exchanger were obtained and are in good agreement with the modified classical film model. It is shown that the plastic air preheater can avoid acid corrosion in the low-temperature field for the boiler using fuel containing sulfur and recover latent heat of the water vapor of the wet flue gas. Also some SO2 was scrubbed during the vapor condensing process in the heat exchanger. © 2001 Scripta Technica, Heat Trans Asian Res, 30(7): 571,580, 2001 [source] Effect of amino acids containing sulfur on dithiolopyrrolone antibiotic productions by Saccharothrix algeriensis NRRL B-24137JOURNAL OF APPLIED MICROBIOLOGY, Issue 2 2006N. Bouras Abstract Aims:, To study the effect of sulfur-containing amino acids (L-cysteine, L-cystine, L-methionine and DL-ethionine) on the production of dithiolopyrrolone antibiotics by Saccharothrix algeriensis NRRL B-24137. Methods and Results:, The production levels of dithiolopyrrolones were investigated by using high performance liquid chromatography in a chemically semi-synthetic medium. The production of the studied antibiotics depends upon the nature, concentration and the time of addition of these sources in the culture medium. Both cysteine and cystine favoured the specific productions of dithiolopyrrolones; iso-butyryl-pyrrothine (ISP) by cysteine, however butanoyl-pyrrothine, senecioyl-pyrrothine and tigloyl-pyrrothine by cystine, when added initially to the culture medium. The maximum specific productions of dithiolopyrrolones were observed in the presence of 5 mmol l,1 cystine for thiolutin, 5 mmol l,1 cysteine for ISP, and 10 mmol l,1 cystine for others studied dithiolopyrrolones as shown in Fig. 3. The production of these antibiotics was decreased when the concentrations of cysteine and cystine were in excess. All dithiolopyrrolone specific productions were strongly inhibited by addition of methionine and ethionine, without inhibition of mycelial growth. Figure 3. Effect of cysteine () and cystine () addition at different concentrations on specific production of thiolutin (a), senecioyl-pyrrothine (b), tigloyl-pyrrothine (c), iso-butyryl-pyrrothine (d) and butanoyl-pyrrothine (e). Specific dithiolopyrrolone productions are given as mg per g of biomass at the time of maximal productions during 96 h of fermentation. Conclusions:, Among all studied amino acids, cystine and cysteine can be used as supplements for improvement the production of dithiolopyrrolone antibiotics by S. algeriensis NRRL B-24137. Significance and Impact of the Study:, Dithiolopyrrolone antibiotics have many important applications for employing them as medicaments, particularly in the treatment of human and animal cancers. In the present work, the influence of containing-sulfur amino acids on dithiolopyrrolone antibiotic productions was studied. The obtained results can be employed for the optimization of the culture medium for the dithiolopyrrolone productions in higher quantities. [source] Improved properties of SBS-modified asphalt with dynamic vulcanizationPOLYMER ENGINEERING & SCIENCE, Issue 5 2002Guian Wen Storage-stable styrene-butadiene-styrene triblock copolymer (SBS)-modified asphalt was prepared by dynamic vulcanization. The vulcanization characteristics of the asphalt/SBS/sulfur blend were studied using a strain-controlled rheometer. The vulcanization of SBS in the asphalt resulted in a marked increase in the torque of the blend. In addition, the vulcanization of a butadiene rubber (BR)/sulfur blend was significantly influenced by the addition of asphalt through a curemeter. The existence of asphalt can accelerate the vulcanization of BR/sulfur blend and reduce its reversion. The preparation process of storage-stable SBS-modified asphalt by dynamic vulcanization was identified by a plot of the electric current versus time. The addition of sulfur to the SBS-modified asphalts resulted in the formation of chemically vulcanized network structures in the modified binders. The physical properties of the SBS-modified asphalt containing sulfur were compared to those of the modified binders without sulfur. The storage stability of the SBS-modified asphalt was effectively improved by the addition of sulfur. The rheological properties of the SBS-modified asphalts before and after adding sulfur were characterized by using dynamic shear rheometry and a rotational viscometer. As indicated by the monitored morphology, the compatibility and high-temperature storage stability of SBS-modified asphalts were improved by the addition of sulfur. [source] | ||||||||||