WorldWideScience

Sample records for 2-chloroethyl ethyl sulfide

  1. A Role for Mitochondrial Oxidative Stress in Sulfur Mustard Analog 2-Chloroethyl Ethyl Sulfide-Induced Lung Cell Injury and Antioxidant Protection

    OpenAIRE

    Gould, Neal S; White, Carl W; Day, Brian J.

    2008-01-01

    Sulfur mustards (SMs) have been used as warfare agents since World War I and still pose a significant threat against civilian and military personnel. SM exposure can cause significant blistering of the skin, respiratory injury, and fibrosis. No antidote currently exists for SM exposure, but recent studies, using the SM analog 2-chloroethyl ethyl sulfide (CEES), have focused on the ability of antioxidants to prevent toxicity. Although antioxidants can prevent CEES-induc...

  2. Role of MAP kinases in regulating expression of antioxidants and inflammatory mediators in mouse keratinocytes following exposure to the half mustard, 2-chloroethyl ethyl sulfide

    OpenAIRE

    Black, Adrienne T.; Joseph, Laurie B.; Casillas, Robert P.; Heck, Diane E.; Gerecke, Donald R.; Sinko, Patrick J; Laskin, Debra L.; Laskin, Jeffrey D.

    2010-01-01

    Dermal exposure to sulfur mustard causes inflammation and tissue injury. This is associated with changes in expression of antioxidants and eicosanoids which contribute to oxidative stress and toxicity. In the present studies we analyzed mechanisms regulating expression of these mediators using an in vitro skin construct model in which mouse keratinocytes were grown at an air-liquid interface and exposed directly to 2-chloroethyl ethyl sulfide (CEES), a model sulfur mustard vesicant. CEES (100...

  3. 2,6-Dithiopurine, a nucleophilic scavenger, protects against mutagenesis in mouse skin treated in vivo with 2-(chloroethyl) ethyl sulfide, a mustard gas analog

    Energy Technology Data Exchange (ETDEWEB)

    Boulware, Stephen [Division of Pharmacy and Toxicology, College of Pharmacy, The University of Texas at Austin, Dell Pediatric Research Institute, 1400 Barbara Jordan Blvd., Austin, TX 78723 (United States); Fields, Tammy; McIvor, Elizabeth; Powell, K. Leslie; Abel, Erika L. [Department of Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Science Park, Smithville, TX 78957 (United States); Vasquez, Karen M. [Division of Pharmacy and Toxicology, College of Pharmacy, The University of Texas at Austin, Dell Pediatric Research Institute, 1400 Barbara Jordan Blvd., Austin, TX 78723 (United States); MacLeod, Michael C., E-mail: mcmacleod@mdanderson.org [Department of Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Science Park, Smithville, TX 78957 (United States)

    2012-09-01

    Sulfur mustard [bis(2-chloroethyl)sulfide, SM] is a well-known DNA-damaging agent that has been used in chemical warfare since World War I, and is a weapon that could potentially be used in a terrorist attack on a civilian population. Dermal exposure to high concentrations of SM produces severe, long-lasting burns. Topical exposure to high concentrations of 2-(chloroethyl) ethyl sulfide (CEES), a monofunctional analog of SM, also produces severe skin lesions in mice. Utilizing a genetically engineered mouse strain, Big Blue, that allows measurement of mutation frequencies in mouse tissues, we now show that topical treatment with much lower concentrations of CEES induces significant dose- and time-dependent increases in mutation frequency in mouse skin; the mutagenic exposures produce minimal toxicity as determined by standard histopathology and immunohistochemical analysis for cytokeratin 6 and the DNA-damage induced phosphorylation of histone H2AX (γ-H2AX). We attempted to develop a therapeutic that would inhibit the CEES-induced increase in mutation frequency in the skin. We observe that multi-dose, topical treatment with 2,6-dithiopurine (DTP), a known chemical scavenger of CEES, beginning 1 h post-exposure to CEES, completely abolishes the CEES-induced increase in mutation frequency. These findings suggest the possibility that DTP, previously shown to be non-toxic in mice, may be useful as a therapeutic agent in accidental or malicious human exposures to SM. -- Highlights: ► 200 mM 2-(chloroethyl) ethyl sulfide (CEES) induces mutations in mouse skin. ► This dose of CEES is not overtly toxic, as assayed by histopathology. ► 2,6-Dithiopurine (DTP), applied after CEES-treatment, abolishes CEES-mutagenesis. ► This supports the idea that sulfur mustards exhibit long biological half-lives.

  4. Expression of proliferative and inflammatory markers in a full-thickness human skin equivalent following exposure to the model sulfur mustard vesicant, 2-chloroethyl ethyl sulfide

    International Nuclear Information System (INIS)

    Sulfur mustard is a potent vesicant that induces inflammation, edema and blistering following dermal exposure. To assess molecular mechanisms mediating these responses, we analyzed the effects of the model sulfur mustard vesicant, 2-chloroethyl ethyl sulfide, on EpiDerm-FTTM, a commercially available full-thickness human skin equivalent. CEES (100-1000 μM) caused a concentration-dependent increase in pyknotic nuclei and vacuolization in basal keratinocytes; at high concentrations (300-1000 μM), CEES also disrupted keratin filament architecture in the stratum corneum. This was associated with time-dependent increases in expression of proliferating cell nuclear antigen, a marker of cell proliferation, and poly(ADP-ribose) polymerase (PARP) and phosphorylated histone H2AX, markers of DNA damage. Concentration- and time-dependent increases in mRNA and protein expression of eicosanoid biosynthetic enzymes including COX-2, 5-lipoxygenase, microsomal PGE2 synthases, leukotriene (LT) A4 hydrolase and LTC4 synthase were observed in CEES-treated skin equivalents, as well as in antioxidant enzymes, glutathione S-transferases A1-2 (GSTA1-2), GSTA3 and GSTA4. These data demonstrate that CEES induces rapid cellular damage, cytotoxicity and inflammation in full-thickness skin equivalents. These effects are similar to human responses to vesicants in vivo and suggest that the full thickness skin equivalent is a useful in vitro model to characterize the biological effects of mustards and to develop potential therapeutics.

  5. Role of MAP kinases in regulating expression of antioxidants and inflammatory mediators in mouse keratinocytes following exposure to the half mustard, 2-chloroethyl ethyl sulfide

    International Nuclear Information System (INIS)

    Dermal exposure to sulfur mustard causes inflammation and tissue injury. This is associated with changes in expression of antioxidants and eicosanoids which contribute to oxidative stress and toxicity. In the present studies we analyzed mechanisms regulating expression of these mediators using an in vitro skin construct model in which mouse keratinocytes were grown at an air-liquid interface and exposed directly to 2-chloroethyl ethyl sulfide (CEES), a model sulfur mustard vesicant. CEES (100-1000 μM) was found to cause marked increases in keratinocyte protein carbonyls, a marker of oxidative stress. This was correlated with increases in expression of Cu,Zn superoxide dismutase, catalase, thioredoxin reductase and the glutathione S-transferases, GSTA1-2, GSTP1 and mGST2. CEES also upregulated several enzymes important in the synthesis of prostaglandins and leukotrienes including cyclooxygenase-2 (COX-2), microsomal prostaglandin E synthase-2 (mPGES-2), prostaglandin D synthase (PGDS), 5-lipoxygenase (5-LOX), leukotriene A4 (LTA4) hydrolase and leukotriene C4 (LTC4) synthase. CEES readily activated keratinocyte JNK and p38 MAP kinases, signaling pathways which are known to regulate expression of antioxidants, as well as prostaglandin and leukotriene synthases. Inhibition of p38 MAP kinase suppressed CEES-induced expression of GSTA1-2, COX-2, mPGES-2, PGDS, 5-LOX, LTA4 hydrolase and LTC4 synthase, while JNK inhibition blocked PGDS and GSTP1. These data indicate that CEES modulates expression of antioxidants and enzymes producing inflammatory mediators by distinct mechanisms. Increases in antioxidants may be an adaptive process to limit tissue damage. Inhibiting the capacity of keratinocytes to generate eicosanoids may be important in limiting inflammation and protecting the skin from vesicant-induced oxidative stress and injury.

  6. Role of TNFR1 in lung injury and altered lung function induced by the model sulfur mustard vesicant, 2-chloroethyl ethyl sulfide

    International Nuclear Information System (INIS)

    Lung toxicity induced by sulfur mustard is associated with inflammation and oxidative stress. To elucidate mechanisms mediating pulmonary damage, we used 2-chloroethyl ethyl sulfide (CEES), a model sulfur mustard vesicant. Male mice (B6129) were treated intratracheally with CEES (3 or 6 mg/kg) or control. Animals were sacrificed 3, 7 or 14 days later and bronchoalveolar lavage (BAL) fluid and lung tissue collected. Treatment of mice with CEES resulted in an increase in BAL protein, an indication of alveolar epithelial damage, within 3 days. Expression of Ym1, an oxidative stress marker also increased in the lung, along with inducible nitric oxide synthase, and at 14 days, cyclooxygenase-2 and monocyte chemotactic protein-1, inflammatory proteins implicated in tissue injury. These responses were attenuated in mice lacking the p55 receptor for TNFα (TNFR1-/-), demonstrating that signaling via TNFR1 is key to CEES-induced injury, oxidative stress, and inflammation. CEES-induced upregulation of CuZn-superoxide dismutase (SOD) and MnSOD was delayed or absent in TNFR1-/- mice, relative to WT mice, suggesting that TNFα mediates early antioxidant responses to lung toxicants. Treatment of WT mice with CEES also resulted in functional alterations in the lung including decreases in compliance and increases in elastance. Additionally, methacholine-induced alterations in total lung resistance and central airway resistance were dampened by CEES. Loss of TNFR1 resulted in blunted functional responses to CEES. These effects were most notable in the airways. These data suggest that targeting TNFα signaling may be useful in mitigating lung injury, inflammation and functional alterations induced by vesicants.

  7. Preparation and application of the sol-gel-derived acrylate/silicone co-polymer coatings for headspace solid-phase microextraction of 2-chloroethyl ethyl sulfide in soil.

    Science.gov (United States)

    Liu, Mingming; Zeng, Zhaorui; Fang, Huaifang

    2005-05-27

    Three types of novel acrylate/silicone co-polymer coatings, including co-poly(methyl acrylate/hydroxy-terminated silicone oil) (MA/OH-TSO), co-poly(methyl methacrylate/OH-TSO) (MMA/OH-TSO) and co-poly(butyl methacrylate/OH-TSO) (BMA/OH-TSO), were prepared for the first time by sol-gel method and cross-linking technology and subsequently applied to headspace solid-phase microextraction (HS-SPME) of 2-chloroethyl ethyl sulfide (CEES), a surrogate of mustard, in soil. The underlying mechanisms of the coating process were discussed and confirmed by IR spectra. The selectivity of the three types of sol-gel-derived acrylate/silicone coated fibers was studied, and the BMA/OH-TSO coated fibers exhibited the highest extraction ability to CEES. The concentration of BMA and OH-TSO in sol solution was optimized, and the BMA/OH-TSO (3:1)-coated fibers possessed the highest extraction efficiency. Compared with commercially available polyacrylate (PA) fiber, the sol-gel-derived BMA/OH-TSO (3:1) fibers showed much higher extraction efficiency to CEES. Therefore, the BMA/OH-TSO (3:1)-coated fibers were chosen for the analysis of CEES in soil matrix. The reproducibility of coating preparation was satisfactory, with the RSD 2.39% within batch and 3.52% between batches, respectively. The coatings proved to be quite stable at high temperature (to 350 degrees C) and in different solvents (organic or inorganic), thus their lifetimes (to 150 times) are longer than conventional fibers. Extraction parameters, such as the volume of water added to the soil, extraction temperature and time, and the ionic strength were optimized. The linearity was from 0.1 to 10 microg/g, the limit of detection (LOD) was 2.7 ng/g, and the RSD was 2.19%. The recovery of CEES was 88.06% in agriculture soil, 92.61% in red clay, and 101.95% in sandy soil, respectively.

  8. Degradation of the blister agent sulfur mustard, bis(2-chloroethyl) sulfide, on concrete.

    Science.gov (United States)

    Brevett, Carol A S; Sumpter, Kenneth B; Wagner, George W; Rice, Jeffrey S

    2007-02-01

    The products formed from the degradation of the blister agent sulfur mustard [bis(2-chloroethyl) sulfide] on concrete were identified using gas chromatography with mass spectrometry detection (GC/MSD), (1)H NMR, 2D (1)H-(13)C NMR and (13)C solid state magic angle spinning (SSMAS) NMR. In situ and extraction experiments were performed. Sulfur mustard was detected in the in situ (13)C SSMAS samples for 12 weeks, whereas less than 5% of the sulfur mustard was detected in extracts from the concrete monoliths after 8 days. Sulfonium ions and (2-chloroethylthio)ethyl ether (T) were observed on the in situ samples after a period of 12 weeks, whereas vinyl species and bis(2-chloroethyl) sulfoxide were observed in the extracts of the concrete monoliths within 24h. The differences between the extraction and the SSMAS data indicated that the sulfur mustard existed in the concrete in a non-extractable form prior to its degradation. Extraction methods alone were not sufficient to identify the products; methods to identify the presence of non-extractable degradation products were also required.

  9. Zinc oxide nanocubes as a destructive nanoadsorbent for the neutralization chemistry of 2-chloroethyl phenyl sulfide: A sulfur mustard simulant.

    Science.gov (United States)

    Kiani, Armin; Dastafkan, Kamran

    2016-09-15

    Zinc oxide nanocubes were surveyed for their destructive turn-over to decontaminate 2-chloro ethyl phenyl sulfide, a sulfur mustard simulant. Prior to the reaction, nanocubes were prepared through sol-gel method using monoethanolamine, diethylene glycol, and anhydrous citric acid as the stabilizing, cross linking/structure directing agents, respectively. The formation of nanoscale ZnO, the cubic morphology, crystalline structure, and chemical-adsorptive characteristics were certified by FESEM-EDS, TEM-SAED, XRD, FTIR, BET-BJH, H2-TPR, and ESR techniques. Adsorption and destruction reactions were tracked by GC-FID analysis in which the effects of polarity of the media, reaction time, and temperature on the destructive capability of the surface of nanocubes were investigated and discussed. Results demonstrated that maximum neutralization occurred in n-heptane solvent after 1/2h at 55°C. Kinetic study construed that the neutralization reaction followed the pseudo-second order model with a squared correlation coefficient and rate constant of 0.9904 and 0.00004gmg(-1)s(-1), respectively. Furthermore, GC-MS measurement confirmed the formation of 2-hydroxy ethyl phenyl sulfide (2-HEPS) and phenyl vinyl sulfide (PVS) as neutralization products that together with Bronsted and Lewis acid/base approaches exemplify the role of hydrolysis and elimination mechanisms on the surface of zinc oxide nanocubes. PMID:27309947

  10. Significance of porous structure on degradatin of 2 2' dichloro diethyl sulphide and 2 chloroethyl ethyl sulphide on the surface of vanadium oxide nanostructure

    International Nuclear Information System (INIS)

    Degradation of the king of chemical warfare agent, 2 2' dichloro diethyl sulphide (HD), and its simulant 2 chloroethyl ethyl sulphide (CEES) were investigated on the surface of porous vanadium oxide nanotubes at room temperature (30 ± 2°C ). Reaction kinetics was monitored by GC-FID technique and the reaction products were characterized by GC-MS. Data indicates that HD degraded faster relative to CEES inside the solid decontaminant compared to the reported liquid phase degradation of CEES and HD. Data explores the role of hydrolysis, elimination and oxidation reactions in the detoxification of HD and CEES and the first order rate constant and t1/2 were calculated to be 0.026 h-1, 26.6 h for CEES and 0.052 h-1, 13.24 h for HD. In this report faster degradation of HD compared to CEES was explained on the basis of porous structure.

  11. Inhibition of NADPH cytochrome P450 reductase by the model sulfur mustard vesicant 2-chloroethyl ethyl sulfide is associated with increased production of reactive oxygen species

    OpenAIRE

    Gray, Joshua P.; Mishin, Vladimir; Heck, Diane E.; Laskin, Debra L.; Laskin, Jeffrey D.

    2010-01-01

    Inhalation of vesicants including sulfur mustard can cause significant damage to the upper airways. This is the result of vesicant-induced modifications of proteins important in maintaining the integrity of the lung. Cytochrome P450’s are the major enzymes in the lung mediating detoxification of sulfur mustard and its metabolites. NADPH cytochrome P450 reductase is a flavin-containing electron donor for cytochrome P450. The present studies demonstrate that the sulfur mustard analog, 2-chloroe...

  12. Reactions of ruthenium hydrides with ethyl-vinyl sulfide.

    Science.gov (United States)

    Dahcheh, Fatme; Stephan, Douglas W

    2014-03-01

    The Ru-hydride precursors (Im(OMe)2)(PPh3)2RuHCl () and (Me2Im(OMe)2)(PPh3)2RuHCl () reacted with ethyl-vinyl-sulfide to give ((MeOCH2CH2)C3H2N2(CH2CH(OMe))RuCl(PPh3)2 () and ((MeOCH2CH2)C3Me2N2(CH2CH(OMe))RuCl(PPh3)2 (), respectively. Dissolution of () in C6D6 prompts formation of ((MeOCH2CH2)C5H6N2(CHCH)RuCl(PPh3)2 (). The analogous reactions of the bis-carbene Ru-hydride precursors (Im(OMe)2)(IMes)(PPh3)RuHCl (), (Im(OMe)2)(SIMes)(PPh3)RuHCl () and (Im(OMe)2)(IMes-Cl2)(PPh3)RuHCl () gave ((MeOCH2CH2)C3H2N2(CHCH)RuCl(PPh3)(NHC) (NHC = IMes (), SIMes (), IMes-Cl2 (), respectively. The formation of compounds () and () is thought to go through an initial insertion of the vinyl-fragment into the Ru-H prompting subsequent C-H activation and loss of diethyl sulfide. This yields () and (), while subsequent loss of methanol yields () and (-). PMID:24441082

  13. Accurate spectroscopic characterization of ethyl mercaptan and dimethyl sulfide isotopologues: a route toward their astrophysical detection

    Energy Technology Data Exchange (ETDEWEB)

    Puzzarini, C. [Dipartimento di Chimica, " Giacomo Ciamician," Università diBologna, Via F. Selmi 2, I-40126 Bologna (Italy); Senent, M. L. [Departamento de Química y Física Teóricas, Institsuto de Estructura de la Materia, IEM-C.S.I.C., Serrano 121, Madrid E-28006 (Spain); Domínguez-Gómez, R. [Doctora Vinculada IEM-CSIC, Departamento de Ingeniería Civil, Cátedra de Química, E.U.I.T. Obras Públicas, Universidad Politécnica de Madrid (Spain); Carvajal, M. [Departamento de Física Aplicada, Facultad de Ciencias Experimentales, Unidad Asociada IEM-CSIC-U.Huelva, Universidad de Huelva, E-21071 Huelva (Spain); Hochlaf, M. [Université Paris-Est, Laboratoire de Modélisation et Simulation Multi Echelle, MSME UMR 8208 CNRS, 5 boulevard Descartes, F-77454 Marne-la-Vallée (France); Al-Mogren, M. Mogren, E-mail: cristina.puzzarini@unibo.it, E-mail: senent@iem.cfmac.csic.es, E-mail: rosa.dominguez@upm.es, E-mail: miguel.carvajal@dfa.uhu.es, E-mail: majdi.hochlaf@u-pem.fr, E-mail: mmogren@ksu.edu.sa [Chemistry Department, Faculty of Science, King Saud University, PO Box 2455, Riyadh 11451 (Saudi Arabia)

    2014-11-20

    Using state-of-the-art computational methodologies, we predict a set of reliable rotational and torsional parameters for ethyl mercaptan and dimethyl sulfide monosubstituted isotopologues. This includes rotational, quartic, and sextic centrifugal-distortion constants, torsional levels, and torsional splittings. The accuracy of the present data was assessed from a comparison to the available experimental data. Generally, our computed parameters should help in the characterization and the identification of these organo-sulfur molecules in laboratory settings and in the interstellar medium.

  14. Synthesis of highly reactive polyisobutylene catalyzed by EtAlCl 2/Bis(2-chloroethyl) ether soluble complex in hexanes

    KAUST Repository

    Kumar, Rajeev Ananda

    2014-03-25

    The polymerization of isobutylene (IB) to yield highly reactive polyisobutylene (HR PIB) with high exo-olefin content using GaCl3 or FeCl3·diisopropyl ether complexes has been previously reported.1 In an effort to further improve polymerization rates and exo-olefin content, we have studied ethylaluminum dichloride (EADC) complexes with diisopropyl ether, 2-chloroethyl ethyl ether (CEEE), and bis(2-chloroethyl) ether (CEE) as catalysts in conjunction with tert-butyl chloride as initiator in hexanes at different temperatures. All three complexes were readily soluble in hexanes. Polymerization, however, was only observed with CEE. At 0 °C polymerization was complete in 5 min at [t-BuCl] = [EADC·CEE] = 10 mM and resulted in PIB with ∼70% exo-olefin content. Studies on complexation using ATR FTIR and 1H NMR spectroscopy revealed that at 1:1 stoichiometry a small amount of EADC remains uncomplexed. By employing an excess of CEE, exo-olefin contents increased up to 90%, while polymerization rates decreased only slightly. With decreasing temperature, polymerization rates decreased while molecular weights as well as exo-olefin contents increased, suggesting that isomerization has a higher activation energy than β-proton abstraction. Density functional theory (DFT) studies on the Lewis acid·ether binding energies indicated a trend consistent with the polymerization results. The polymerization mechanism proposed previously for Lewis acid·ether complexes1 adequately explains all the findings. © 2014 American Chemical Society.

  15. Aminoalkylated Merrifield Resins Reticulated by Tris-(2-chloroethyl Phosphate for Cadmium, Copper, and Iron (II Extraction

    Directory of Open Access Journals (Sweden)

    Mokhtar Dardouri

    2015-01-01

    Full Text Available We aimed to synthesize novel substituted polymers bearing functional groups to chelate heavy metals during depollution applications. Three polyamine functionalized Merrifield resins were prepared via ethylenediamine (EDA, diethylenetriamine (DETA, and triethylenetetramine (TETA modifications named, respectively, MR-EDA, MR-DETA, and MR-TETA. The aminoalkylated polymers were subsequently reticulated by tris-(2-chloroethyl phosphate (TCEP to obtain new polymeric resins called, respectively, MR-EDA-TCEP, MR-DETA-TCEP, and MR-TETA-TCEP. The obtained resins were characterized via attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR, elemental analysis (EA, and thermogravimetric (TGA, thermodynamic (DTA, and differential thermogravimetric (DTG analysis. The synthesized resins were then assayed to evaluate their efficiency to extract metallic ions such as Cd2+, Cu2+, and Fe2+ from aqueous solutions.

  16. Hydrogen sulfide production during yeast fermentation causes the accumulation of ethanethiol, S-ethyl thioacetate and diethyl disulfide.

    Science.gov (United States)

    Kinzurik, Matias I; Herbst-Johnstone, Mandy; Gardner, Richard C; Fedrizzi, Bruno

    2016-10-15

    Hydrogen sulfide (H2S) is produced by yeast during winemaking and possesses off-flavors reminiscent of rotten eggs. The production of H2S during fermentation has also been associated in the finished wine with the rise of additional volatile sulfur compounds (VSCs) with strong aromas of cooked onions and vegetables. To characterize these more complex VSCs produced from H2S, we performed fermentations in synthetic grape juice. H2S production was manipulated experimentally by feeding increasing concentrations of sulfate to mutant strains that are unable to incorporate H2S efficiently as part of the sulfur assimilation pathway. In finished wines from these mutants, three VSCs - ethanethiol, S-ethyl thioacetate and diethyl disulfide - increased proportionally to H2S. (34)S-labeled sulfate fed to the MET17-deleted strain was incorporated into same three VSCs, demonstrating that they are formed directly from H2S. PMID:27173572

  17. Potentiation in the intact rat of the hepatotoxicity of acetaminophen by 1,3-bis(2-chloroethyl)-1-nitrosourea.

    Science.gov (United States)

    Nakae, D; Oakes, J W; Farber, J L

    1988-12-01

    Studies of the killing of cultured hepatocytes by acetaminophen indicate that the cells are injured by an oxidative stress that accompanies the metabolism of the toxin (J. L. Farber et al. (1988) Arch. Biochem. Biophys. 267, 640-650). The present report documents that the essential features of the killing of cultured hepatocytes by acetaminophen are reproduced in the intact animal. Male rats had no evidence of liver necrosis 24 h after administration of up to 1000 mg/kg of acetaminophen. Induction of mixed function oxidase activity by 3-methylcholanthrene increased the hepatotoxicity of acetaminophen. Inhibition of glutathione reductase by 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) potentiated the hepatotoxicity of acetaminophen in male rats induced with 3-methylcholanthrene. Whereas the pretreatment with BCNU reduced the GSH content by 40%, a comparable depletion of GSH by diethylmaleate did not potentiate the toxicity of acetaminophen. The antioxidant diphenylphenylenediamine (25 mg/kg) and the ferric iron chelator deferoxamine (1000 mg/kg) prevented the liver necrosis produced by 500 mg/kg acetaminophen in rats pretreated with BCNU. Neither protective agent prevented the fall in GSH produced by acetaminophen. It is concluded the conditions of the irreversible injury of cultured hepatocytes by acetaminophen previously reported are not necessarily different from those that obtain in the intact rat with this toxin. PMID:3214175

  18. Pigment Changes Associated with Application of Ethephon ((2-Chloroethyl)phosphonic Acid) to Fig (Ficus carica L.) Fruits.

    Science.gov (United States)

    Puech, A A; Rebeiz, C A; Crane, J C

    1976-04-01

    The application of (2-chloroethyl)phosphonic acid (Ethephon) to ;Mission' fig fruits (Ficus carica L.) during late period II of their development stimulated ripening and change in color from green to bluish black within 8 days. Chlorophylls a and b decreased rapidly within 4 days after Ethephon treatment, and degradation continued at a decreasing rate for an additional 4 days, at which time the fruits had attained their maximum diameter and were considered fully ripe. Levels of beta-carotene, lutein, violaxanthin, and neoxanthin decreased in a pattern similar to that of chlorophylls a and b. The rates of beta-carotene and lutein degradation were initially greater than those of the xanthophyll pigments. Degradation rates of the various carotenoids were comparable 4 to 8 days after treatment.There was no measurable anthocyanin synthesis during a 2- to 4-day period following Ethephon treatment. Beyond this lag phase, anthocyanin accumulation was linear, and the amount of pigment synthesized was a function of both light intensity and duration. Although Ethephon promoted the rate of anthocyanin accumulation, it did not increase the total amount of pigment synthesized in treated fruits. Etiolation of fruits from the time of Ethephon treatment until maturity stimulated an increase in growth and completely inhibited anthocyanin production in the skin. Ethephon-treated fruits which ripened while etiolated were larger in diameter and higher in both fresh and dry weights than nonetiolated controls.

  19. In vivo potentiation of 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea by the radiation sensitizer benznidazole

    International Nuclear Information System (INIS)

    Recent studies in mouse tumor systems have indicated a potential therapeutic advantage in combining the radiosensitizer misonidazole (MISO) with cancer chemotherapy drugs. One agent the antitumor activity of which has been enhanced to a greater extent than its hematological or gastrointestinal toxicities is the nitrosourea, 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU). Recently, sensitizers more lipophylic than MISO have been reported to give greater tumor response enhancement when combined with CCNU. The present studies compared the potential therapeutic benefit of combining MISO (partition coefficient, 0.43) or benznidazole (BENZO) (partition coefficient, 8.5) in KHT sarcoma or RIF-1 tumor-bearing C3H mice. Both sensitizers were administered i.p. and given either 30 min before (BENZO) or simultaneously with (MISO) the chemotherapeutic agent. Survival of clonogenic tumor cells assessed 22 to 24 hr after treatment or in situ tumor growth delay were used as assays of tumor response. Normal tissue toxicity was determined using the drug dose yielding 50% animal lethality in 30 days end point. When combined with CCNU, doses of MISO (5.0 mmol/kg) or BENZO (0.3 mmol/kg) were found to yield approximately equivalent increases in both the tumor effect (enhancement ratio, approximately 1.8 to 2.0) and normal tissue toxicity (enhancement ratio approximately 1.3 to 1.4). Both sensitizers therefore led to a therapeutic benefit. However, although a approximately 10-fold lower dose of the more lipophylic sensitizer BENZO proved to be as effective as MISO at enhancing the tumoricidal effects of CCNU, this dose reduction did not result in a greater therapeutic gain for BENZO

  20. 1,3-Bis(2-chloroethyl)-1-nitrosourea-loaded bovine serum albumin nanoparticles with dual magnetic resonance–fluorescence imaging for tracking of chemotherapeutic agents

    Science.gov (United States)

    Wei, Kuo-Chen; Lin, Feng-Wei; Huang, Chiung-Yin; Ma, Chen-Chi M; Chen, Ju-Yu; Feng, Li-Ying; Yang, Hung-Wei

    2016-01-01

    To date, knowing how to identify the location of chemotherapeutic agents in the human body after injection is still a challenge. Therefore, it is urgent to develop a drug delivery system with molecular imaging tracking ability to accurately understand the distribution, location, and concentration of a drug in living organisms. In this study, we developed bovine serum albumin (BSA)-based nanoparticles (NPs) with dual magnetic resonance (MR) and fluorescence imaging modalities (fluorescein isothiocyanate [FITC]-BSA-Gd/1,3-bis(2-chloroethyl)-1-nitrosourea [BCNU] NPs) to deliver BCNU for inhibition of brain tumor cells (MBR 261-2). These BSA-based NPs are water dispersible, stable, and biocompatible as confirmed by XTT cell viability assay. In vitro phantoms and in vivo MR and fluorescence imaging experiments show that the developed FITC-BSA-Gd/BCNU NPs enable dual MR and fluorescence imaging for monitoring cellular uptake and distribution in tumors. The T1 relaxivity (R1) of FITC-BSA-Gd/BCNU NPs was 3.25 mM−1 s−1, which was similar to that of the commercial T1 contrast agent (R1 =3.36 mM−1 s−1). The results indicate that this multifunctional drug delivery system has potential bioimaging tracking of chemotherapeutic agents ability in vitro and in vivo for cancer therapy. PMID:27601895

  1. 1,3-Bis(2-chloroethyl)-1-nitrosourea-loaded bovine serum albumin nanoparticles with dual magnetic resonance-fluorescence imaging for tracking of chemotherapeutic agents.

    Science.gov (United States)

    Wei, Kuo-Chen; Lin, Feng-Wei; Huang, Chiung-Yin; Ma, Chen-Chi M; Chen, Ju-Yu; Feng, Li-Ying; Yang, Hung-Wei

    2016-01-01

    To date, knowing how to identify the location of chemotherapeutic agents in the human body after injection is still a challenge. Therefore, it is urgent to develop a drug delivery system with molecular imaging tracking ability to accurately understand the distribution, location, and concentration of a drug in living organisms. In this study, we developed bovine serum albumin (BSA)-based nanoparticles (NPs) with dual magnetic resonance (MR) and fluorescence imaging modalities (fluorescein isothiocyanate [FITC]-BSA-Gd/1,3-bis(2-chloroethyl)-1-nitrosourea [BCNU] NPs) to deliver BCNU for inhibition of brain tumor cells (MBR 261-2). These BSA-based NPs are water dispersible, stable, and biocompatible as confirmed by XTT cell viability assay. In vitro phantoms and in vivo MR and fluorescence imaging experiments show that the developed FITC-BSA-Gd/BCNU NPs enable dual MR and fluorescence imaging for monitoring cellular uptake and distribution in tumors. The T1 relaxivity (R1) of FITC-BSA-Gd/BCNU NPs was 3.25 mM(-1) s(-1), which was similar to that of the commercial T1 contrast agent (R1 =3.36 mM(-1) s(-1)). The results indicate that this multifunctional drug delivery system has potential bioimaging tracking of chemotherapeutic agents ability in vitro and in vivo for cancer therapy. PMID:27601895

  2. O6-alkylguanine-DNA alkyltransferase activity correlates with the therapeutic response of human rhabdomyosarcoma xenografts to 1-(2-chloroethyl)-3-(trans-4-methylcyclohexyl)-1-nitrosourea

    International Nuclear Information System (INIS)

    Immune-deprived female CBA/CaJ mice bearing xenografts of six different human rhabdomyosarcoma lines were treated with 1-(2-chloroethyl)-3-(trans-4-methylcyclohexyl)-1-nitrosourea (MeCCNU). Tumor responses were compared with levels of O6-methylguanine-DNA methyltransferase activity because of evidence indicating that repair of DNA interstrand cross-link precursors, mediated by the transferase, may be an important determinant of MeCCNU cytotoxicity. Levels of methyltransferase in tumor extracts were measured by determining the loss of O6-methylguanine from 3H-labeled methylated DNA. Five of the six tumor lines examined showed either no response to MeCCNU or regrowth after an incomplete response. In each instance, the extent of tumor regression correlated with the level of O6-methylguanine-DNA methyltransferase activity in tumor extracts. These results suggest that O6-methylguanine-DNA methyltransferase levels in human tumor cells may be a clinically useful predictor of sensitivity to the chloroethylnitrosoureas

  3. Miscoding properties of 1,N{sup 6}-ethanoadenine, a DNA adduct derived from reaction with antitumor agent 1,3-bis(2-chloroethyl)-1-nitrosourea

    Energy Technology Data Exchange (ETDEWEB)

    Hang, Bo; Guliaev, Anton B.; Chenna, Ahmed; Singer, B.

    2003-03-05

    1,N{sup 6}-Ethanoadenine (EA) is an exocyclic adduct formed from DNA reaction with the antitumor agent, 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU). To understand the role of this adduct in the mechanism of mutagenicity or carcinogenicity by BCNU, an oligonucleotide with a site-specific EA was synthesized using phosphoramidite chemistry. We now report the in vitro miscoding properties of EA in translesion DNA synthesis catalyzed by mammalian DNA polymerases (pols) {alpha}, {beta}, {eta} and {iota}. These data were also compared with those obtained for the structurally related exocyclic adduct, 1,N{sup 6}-ethenoadenine ({var_epsilon}A). Using a primer extension assay, both pols {alpha} and {beta} were primarily blocked by EA or {var_epsilon}A with very minor extension. Pol {eta} a member of the Y family of polymerases, was capable of catalyzing a significant amount of bypass across both adducts. Pol {eta} incorporated all four nucleotides opposite EA and {var_epsilon}A, but with differential preferences and mainly in an error-prone manner. Human pol {iota}, a paralog of human pol {eta}, was blocked by both adducts with a very small amount of synthesis past {var_epsilon}A. It incorporated C and, to a much lesser extent, T, opposite either adduct. In addition, the presence of an A adduct, e.g. {var_epsilon}A, could affect the specificity of pol {iota} toward the template T immediately 3 feet to the adduct. In conclusion, the four polymerases assayed on templates containing an EA or {var_epsilon}A showed differential bypass capacity and nucleotide incorporation specificity, with the two adducts not completely identical in influencing these properties. Although there was a measurable extent of error-free nucleotide incorporation, all these polymerases primarily misincorporated opposite EA, indicating that the adduct, similar to {var_epsilon}A, is a miscoding lesion.

  4. [Determination of tris (2-chloroethyl) phosphate in leather by gas chromatography-mass spectrometry coupled with mixed-mode sorbent solid phase extraction].

    Science.gov (United States)

    Zhang, Weiya; Zhu, Yuling; Wang, Chengyun; Li, Lixia; Zhang, Junqing; Xing, Jun

    2014-10-01

    Leather is one of the important exporting products to European Union (EU), and tris(2-chloroethyl) phosphate (TCEP) is a commonly used flame retardant in leather and leather products. Recently, TCEP has been classified as a kind of substance of very high concern (SVHC) by EU for its carcinogenicity and reproductive toxicity. But to date, there is not a recognized method for the determination of TCEP in leather and leather products due to the serious matrix interferences and relatively low recovery of TCEP. In this work, a home-made mixed-mode sorbent (Silica-WCX) with carboxyl and alkyl groups was tested as the sorbent of solid phase extraction (SPE) to extract TECP from leather. The results demonstrated that, making the carboxyl groups protonized under acidic condition, Silica-WCX exhibited better extraction performance towards TCEP over some frequently used commercial sorbents tested. After the optimization of the SPE conditions based on Silica-WCX, a method of gas chromatography/mass spectrometry (GC-MS) was established for the determination of TCEP in leather samples. The linear range for TCEP ranged from 0.10 to 100.0 μg/L and the limit of quantification (LOQ, S/N = 10) was 44.46 ng/kg. The recoveries of TCEP spiked in samples at varied levels were in the range of 91.45%-99.98% with the relative standard deviations (RSDs) of 4.33%-5.97%. The method is simple, sensitive and reliable for the analysis of TCEP in leather and leather products.

  5. HILIC-MS Determination of Genotoxic Impurity of 2-Chloro-N-(2-Chloroethyl)Ethanamine in the Vortioxetine Manufacturing Process.

    Science.gov (United States)

    Douša, Michal; Klvaňa, Robert; Doubský, Jan; Srbek, Jan; Richter, Jindřich; Exner, Marek; Gibala, Petr

    2016-02-01

    In the last decade, pharmaceutical regulatory agencies are focused on monitoring and evaluation of trace-level genotoxic impurities (GTIs) in drug substances, which requires manufacturers to deliver innovative approaches for their analysis and control. GTIs in the low p.p.m. level rising from the process of drug production have to be positively identified and quantified. Therefore, sensitive and selective analytical methods are necessary for required quantification level of these GTIs. Unfortunately, general guidance on how to develop strategy of the analysis and control of GTIs is currently missing in the pharmaceutical industry. Therefore, practical example of the analytical control of 2-chloro-N-(2-chloroethyl)ethanamine GTI in the vortioxetine (VOR) manufacturing process was demonstrated in this work. QDa mass detection with electrospray ionization in selected-ion recording mode was utilized for quantitation of GTIs. The method of hydrophilic interaction liquid chromatography coupled with mass spectrometry detection (HILIC-MS) was validated as per International Conference on Harmonization guidelines and was able to quantitate GTIs at 75 p.p.m. with respect to VOR. The HILIC-MS method was achieved using a Primesep B column (150 × 4.6 mm, 5.0 µm; Sielc, USA) using mobile phase consisting of 10 mM ammonium formate buffer pH 3.0 and acetonitrile (5 : 95, v/v) at 0.8 mL/min flow rate. The QDa mass detector was operated in the positive ion mode. Quadrupole mass analyzer was employed in selected-ion monitoring mode using target ion at m/z 142 as [M+H](+). PMID:26223463

  6. In vitro release of 1,3-bis (2-chloroethyl)-1-nitrosourea sustained-release microspheres and the distribution in rat brain tissues

    Institute of Scientific and Technical Information of China (English)

    Xia Li; Liping Guo; Qin Li

    2006-01-01

    BACKGROUND: The implantation of released chemotherapeutic drugs, which takes biodegradable polymer as vector, into the tumor site can get high concentration and release the drug for a long time, it can directly act on the tumor cells, and reduce the general toxicity.OBJECTIVE: To explore the in vitro and in vivo course of 1,3-bis (2-chloroethyl)-1-nitrosourea (BCNU) sustained-release from BCNU-loaded polylactide (PLA) microspheres (MS) and location in rat brain tissue.DESIGN: A repetitive measurement.SETTING: Central Pharmacy, General Hospital of Chinese People's Armed Police Forces.MATERIALS: Thirty male SD rats were used. PLA (Mr5000, batch number: KSL8377) was produced by Wako Pure Chemical Inc.,Ltd. (Japan); BCNU (batch number: 021121) by Tianjin Jinyao Amino Acid Co., Ltd.;BCNU-PLA-MS was prepared by the method of solvent evaporation and pressed into tablets (10 mg/tablet).High-performance liquid chromatography (HPLC) Agilent 1100 (USA); LS9800 liquid-scintillation radiometric apparatus (Beckman). Chromatographic conditions: Elite Hypersil ODS2 C18 chromatographic column (5 μm,4.6 mm ×150 mm); Mobile phase: methanol: water (50:50), flow rate was 1.0 mL per minute, wave length of ultraviolet detection was 237 nm, and the inlet amount of samples was 10 μL.METHODS: The experiments were carried out in the experimental animal center of the General Hospital of Chinese Armed Police from May 2004 to July 2005. ① In vitro BCNU-PLA-MS release test: BCNU-PLA-MS was prepared by the method of solvent evaporation, then placed in 0.1 mol/L phosphate buffered solution (PBS, pH 7.4, 37 ℃), part of MS were taken out at 1, 2, 3, 7, 10 and 15 days respectively, and the rest amount of BCNU in MS was determined by HPLC, then the curve of BCNU-PLA-MS release was drawn. ②In vivo BCNU-PLA-MS release and distribution test: The rats were anesthetized, then BCNU-PLA-MS were implanted to the site 1 mm inferior to the cortex of frontal lobe. Five rats were killed postoperatively

  7. Selenium Sulfide

    Science.gov (United States)

    Selenium sulfide, an anti-infective agent, relieves itching and flaking of the scalp and removes the dry, scaly particles ... Selenium sulfide comes in a lotion and is usually applied as a shampoo. As a shampoo, selenium sulfide usually ...

  8. Influence of glutathione and glutathione S-transferases on DNA interstrand cross-link formation by 1,2-bis(methylsulfonyl)-1-(2-chloroethyl)hydrazine, the active anticancer moiety generated by laromustine.

    Science.gov (United States)

    Penketh, Philip G; Patridge, Eric; Shyam, Krishnamurthy; Baumann, Raymond P; Zhu, Rui; Ishiguro, Kimiko; Sartorelli, Alan C

    2014-08-18

    Prodrugs of 1,2-bis(methylsulfonyl)-1-(2-chloroethyl)hydrazine (90CE) are promising anticancer agents. The 90CE moiety is a readily latentiated, short-lived (t1/2 ∼ 30 s) chloroethylating agent that can generate high yields of oxophilic electrophiles responsible for the chloroethylation of the O-6 position of guanine in DNA. These guanine O-6 alkylations are believed to be responsible for the therapeutic effects of 90CE and its prodrugs. Thus, 90CE demonstrates high selectivity toward tumors with diminished levels of O(6)-alkylguanine-DNA alkyltransferase (MGMT), the resistance protein responsible for O(6)-alkylguanine repair. The formation of O(6)-(2-chloroethyl)guanine lesions ultimately leads to the generation of highly cytotoxic 1-(N(3)-cytosinyl),-2-(N(1)-guaninyl)ethane DNA interstrand cross-links via N(1),O(6)-ethanoguanine intermediates. The anticancer activity arising from this sequence of reactions is thus identical to this component of the anticancer activity of the clinically used chloroethylnitrosoureas. Herein, we evaluate the ability of glutathione (GSH) and other low molecular weight thiols, as well as GSH coupled with various glutathione S-transferase enzymes (GSTs) to attenuate the final yields of cross-links generated by 90CE when added prior to or immediately following the initial chloroethylation step to determine the major point(s) of interaction. In contrast to studies utilizing BCNU as a chloroethylating agent by others, GSH (or GSH/GST) did not appreciably quench DNA interstrand cross-link precursors. While thiols alone offered little protection at either alkylation step, the GSH/GST couple was able to diminish the initial yields of cross-link precursors. 90CE exhibited a very different GST isoenzyme susceptibility to that reported for BCNU, this could have important implications in the relative resistance of tumor cells to these agents. The protection afforded by GSH/GST was compared to that produced by MGMT.

  9. Preclinical activity of 17 beta-[N-[N'-(2-chloroethyl)-N'-nitrosocarbamoyl]-L-alanyl]-5 alpha-dihydrotestosterone (E91) against tumour colony forming units and haematopoietic progenitor cells.

    Science.gov (United States)

    Rank, P; Peter, R; Depenbrock, H; Eisenbrand, G; Schmid, P; Pitzl, H; Hanauske, A R

    1999-06-01

    E91 (17 beta-[N-[N'-(2-chloroethyl)-N'-nitrosocarbamoyl]-L-alanyl]-5 alpha-dihydrotestosterone) (CNC-ala-DHT) is a newly synthesised alkylating compound consisting of N-[N'-(2-chloroethyl)-N'-nitrosocarbamoyl]-L-alanine (CNC-ala) as the alkylating moiety and of 5 alpha-dihydrotestosterone (DHT) as a steroid carrier molecule. We studied the antitumour activity of E91 (final concentrations: 0.1, 1, 10 and 30 mumol/l) against freshly explanted human tumours, using an in vitro soft agar cloning system. A total of 54 tumour samples was evaluated using 1 h-exposure and 51 tumour specimens were studied using a continuous exposure for 21-28 days. In addition, the compound's activity was compared with other clinically used anticancer agents. After short-term exposure, 49 of 53 evaluable specimens (92%) had adequate colony formation, as compared with 49 of 50 (98%) after long-term exposure. After short-term exposure, E91 exhibited only marginal antitumour activity. However, in long-term exposure experiments, E91 had marked and concentration-dependent antitumour activity (P 10 mumol/l, E91 was as active as the other clinically used antineoplastic agents and at 30 mumol/l, E91 was significantly more active than 5-fluorouracil (P = 0.041). E91 showed activity against a wide spectrum of tumour types. The highest activity was observed against colorectal carcinomas (3/4 tumour specimens inhibited at 30 mumol/l). Sensitivity was also high remarkable in breast cancer specimens with 3/6 specimens inhibited at 30 mumol/l. In vitro myelotoxicity was less than that of doxorubicin. At 30 mumol/l, E91 induced a reduction of colony forming units-granulocyte macrophage (CFU-GM) to only 53% of control and of CFU-GEMM to 20% of control. We conclude that because of broad activity and reduced myelotoxicity further clinical development of E91 appears warranted. PMID:10533486

  10. Synthesis, characterization, crystal structure determination and computational study of a new Cu(II) complex of bis [2-{(E)-[2-chloroethyl)imino]methyl}phenolato)] copper(II) Schiff base complex

    Science.gov (United States)

    Grivani, Gholamhossein; Vakili, Mohammad; Khalaji, Aliakbar Dehno; Bruno, Giuseppe; Rudbari, Hadi Amiri; Taghavi, Maedeh

    2016-07-01

    The copper (II) Schiff base complex of [CuL2] (1), HL = 2-{(E)-[2-chloroethyl) imino]methyl}phenol, has been synthesized and characterized by elemental (CHN) analysis, UV-Vis and FT-IR spectroscopy. The molecular structure of 1 was determined by single crystal X-ray diffraction technique. The conformational analysis and molecular structures of CuL2 were investigated by means of density functional theory (DFT) calculations at B3LYP/6-311G* level. An excellent agreement was observed between theoretical and experimental results. The Schiff base ligand of HL acts as a chelating ligand and coordinates via one nitrogen atom and one oxygen atom to the metal center. The copper (II) center is coordinated by two nitrogen atoms and two oxygen atoms from two Schiff base ligands in an approximately square planar trans-[MN2O2] coordination geometry. Thermogravimetric analysis of CuL2 showed that it was decomposed in five stages. In addition, the CuL2 complex thermally decomposed in air at 660 °C and the XRD pattern of the obtained solid showed the formation of CuO nanoparticles with an average size of 34 nm.

  11. Zmiany w składzie chemicznym ściany komórkowej źdźbła pszenicy traktomanej chlorkiem chlorocholiny (CCC [Changes in the cell walls of wheat culms treated utith 2-chloroethyl-trime-thyl-ammonium chloride (CCC

    Directory of Open Access Journals (Sweden)

    Maria Przeszlakowska

    2015-06-01

    Full Text Available The influence of 2-chloroethyl-trimethyl-ammonium chloride (CCC on the content of various constituents of the cell wall of the wheat culms var. Eka Nowa was investigated. Chromatographic analysis of the polysaccharides obtained from the cell wall of the wheat culms has been carried out. The content of pectic substances (pectins and protopectins in nodes and internodes of the wheat culms treated with CCC was determined.

  12. 21 CFR 584.200 - Ethyl alcohol containing ethyl acetate.

    Science.gov (United States)

    2010-04-01

    ... Ethyl alcohol containing ethyl acetate. The feed additive ethyl alcohol containing ethyl acetate meets the requirement of 27 CFR 21.62, being not less than 92.5 percent ethyl alcohol, each 100 gallons... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ethyl alcohol containing ethyl acetate....

  13. Comparative Analysis of Experiment Treating Benzene and CEES by Pulse Corona Plasma

    Institute of Scientific and Technical Information of China (English)

    Yan Xuefeng; Hu Zhen

    2005-01-01

    Based on an experiment treating benzene and 2-chloroethyl ethyl sulfide ( CEES )by pulse corona induced-plasma, the similarities and differences found in the experimental data and analytical results are analyzed in a comparative manner in this paper. The theory applied is also discussed.

  14. NTP Toxicology and Carcinogenesis Studies of Tris(2-chloroethyl) Phosphate (CAS No. 115-96-8) in F344/N Rats and B6C3F1 Mice (Gavage Studies).

    Science.gov (United States)

    1991-05-01

    Tris(2-chloroethyl) phosphate (TRCP), a flame-retardant plasticizer used in plastics, polymeric foams, and synthetic fibers, was studied as part of the National Toxicology Program's class study of trisalkyl phosphate flame retardants. Toxicology and carcinogenesis studies were conducted by administering TRCP (approximately 98% pure) in corn oil by gavage to groups of F344/N rats and B6C3F1 mice of each sex for 16 days, 16 weeks, or 2 years. Genetic toxicology studies were performed in Salmonella typhimurium and Chinese hamster ovary (CHO) cells. 16-Day Studies: There were no chemical-related deaths, differences in final mean body weight, or histopathological lesions in rats receiving 22 to 350 mg/kg TRCP or in mice receiving 44 to 700 mg/kg TRCP for 12 doses over 16 days. Serum cholinesterase activity in female rats receiving 175 or 350 mg/kg TRCP was reduced slightly (80% of control levels), but enzyme activity in dosed male rats and in mice was similar to that in controls. 16-Week Studies: Rats received 22 to 350 mg/kg TRCP for 16 weeks (female) or 18 weeks (male). Several male and female rats in the 175 or 350 mg/kg dose groups died from chemical toxicity. Final mean body weights of female rats receiving 350 mg/kg were 20% greater than those of controls; final mean body weights of the remaining groups of dosed female rats and dosed male rats were similar. Chemical-related neuronal necrosis occurred in the hippocampus and thalamus of female rats and, to a lesser extent, of male rats. Serum cholinesterase activity was reduced in females receiving 175 or 350 mg/kg TRCP. There were no chemical-related deaths, differences in final mean body weight, or differences in cholinesterase activity in mice receiving 44 to 700 mg/kg TRCP for 16 weeks. Tubule epithelial cells with enlarged nuclei (cytomegaly and karyomegaly) were observed in the kidneys of high-dose (700 mg/kg) male and female mice. 2-Year Studies: The 2-year studies in rats were conducted by administering 0

  15. Protective Effect of Liposome-Encapsulated Glutathione in a Human Epidermal Model Exposed to a Mustard Gas Analog

    OpenAIRE

    Victor Paromov; Sudha Kumari; Marianne Brannon; Kanaparthy, Naga S.; Hongsong Yang; Smith, Milton G.; Stone, William L

    2011-01-01

    Sulfur mustard or mustard gas (HD) and its monofunctional analog, 2-chloroethyl ethyl sulfide (CEES), or “half-mustard gas,” are alkylating agents that induce DNA damage, oxidative stress, and inflammation. HD/CEES are rapidly absorbed in the skin causing extensive injury. We hypothesize that antioxidant liposomes that deliver both water-soluble and lipid-soluble antioxidants protect skin cells from immediate CEES-induced damage via attenuating oxidative stress. Liposomes containing water-sol...

  16. 21 CFR 173.228 - Ethyl acetate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethyl acetate. 173.228 Section 173.228 Food and..., Lubricants, Release Agents and Related Substances § 173.228 Ethyl acetate. Ethyl acetate (CAS Reg. No. 141-78... the specifications of the Food Chemicals Codex, 1 (Ethyl Acetate; p. 372, 3d Ed., 1981), which...

  17. Use of ethyl glucuronide and ethyl sulphate in forensic toxicology

    OpenAIRE

    2009-01-01

    List of papers I. Høiseth G, Karinen R, Christophersen AS, Olsen L, Normann PT, Mørland J. (2007) A study of ethyl glucuronide in post-mortem blood as a marker of ante-mortem ingestion of alcohol. Forensic Sci Int 165:41-45 II. Høiseth G, Karinen R, Johnsen L, Normann PT, Christophersen AS, Mørland J. (2008) Disappearance of ethyl glucuronide during heavy putrefaction. For Sci Int. 176:147-51 III. Høiseth G, Kristoffersen L, Larssen B, Arnestad M, Hermansen NO, Mørland J.(2008) ...

  18. Ethyl diazoacetate synthesis in flow

    Directory of Open Access Journals (Sweden)

    Mariëlle M. E. Delville

    2013-09-01

    Full Text Available Ethyl diazoacetate is a versatile compound in organic chemistry and frequently used on lab scale. Its highly explosive nature, however, severely limits its use in industrial processes. The in-line coupling of microreactor synthesis and separation technology enables the synthesis of this compound in an inherently safe manner, thereby making it available on demand in sufficient quantities. Ethyl diazoacetate was prepared in a biphasic mixture comprising an aqueous solution of glycine ethyl ester, sodium nitrite and dichloromethane. Optimization of the reaction was focused on decreasing the residence time with the smallest amount of sodium nitrite possible. With these boundary conditions, a production yield of 20 g EDA day−1 was achieved using a microreactor with an internal volume of 100 μL. Straightforward scale-up or scale-out of microreactor technology renders this method viable for industrial application.

  19. SULFIDE METHOD PLUTONIUM SEPARATION

    Science.gov (United States)

    Duffield, R.B.

    1958-08-12

    A process is described for the recovery of plutonium from neutron irradiated uranium solutions. Such a solution is first treated with a soluble sullide, causing precipitation of the plutoniunn and uraniunn values present, along with those impurities which form insoluble sulfides. The precipitate is then treated with a solution of carbonate ions, which will dissolve the uranium and plutonium present while the fission product sulfides remain unaffected. After separation from the residue, this solution may then be treated by any of the usual methods, such as formation of a lanthanum fluoride precipitate, to effect separation of plutoniunn from uranium.

  20. Sulfide oxidation in a biofilter

    DEFF Research Database (Denmark)

    Pedersen, Claus Lunde; Liu, Dezhao; Hansen, Michael Jørgen;

    2012-01-01

    Observed hydrogen sulfide uptake rates in a biofilter treating waste air from a pig farm were too high to be explained within conventional limits of sulfide solubility, diffusion in a biofilm and bacterial metabolism. Clone libraries of 16S and 18S rRNA genes from the biofilter found no sulfide...

  1. Sulfide oxidation in a biofilter

    DEFF Research Database (Denmark)

    Pedersen, Claus Lunde; Dezhao, Liu; Hansen, Michael Jørgen;

    Observed hydrogen sulfide uptake rates in a biofilter treating waste air from a pig farm were too high to be explained within conventional limits of sulfide solubility, diffusion in a biofilm and bacterial metabolism. Clone libraries of 16S and 18S rRNA genes from the biofilter found no sulfide...

  2. 27 CFR 21.107 - Ethyl acetate.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Ethyl acetate. 21.107....107 Ethyl acetate. (a) 85 percent ester: (1) Acidity (as acetic acid). Not more than 0.015 percent by...); for incorporation by reference, see § 21.6(b).) When 100 ml of ethyl acetate are distilled by...

  3. Sulfide detoxification in plant mitochondria.

    Science.gov (United States)

    Birke, Hannah; Hildebrandt, Tatjana M; Wirtz, Markus; Hell, Rüdiger

    2015-01-01

    In contrast to animals, which release the signal molecule sulfide in small amounts from cysteine and its derivates, phototrophic eukaryotes generate sulfide as an essential intermediate of the sulfur assimilation pathway. Additionally, iron-sulfur cluster turnover and cyanide detoxification might contribute to the release of sulfide in mitochondria. However, sulfide is a potent inhibitor of cytochrome c oxidase in mitochondria. Thus, efficient sulfide detoxification mechanisms are required in mitochondria to ensure adequate energy production and consequently survival of the plant cell. Two enzymes have been recently described to catalyze sulfide detoxification in mitochondria of Arabidopsis thaliana, O-acetylserine(thiol)lyase C (OAS-TL C), and the sulfur dioxygenase (SDO) ethylmalonic encephalopathy protein 1 (ETHE1). Biochemical characterization of sulfide producing and consuming enzymes in mitochondria of plants is fundamental to understand the regulatory network that enables mitochondrial sulfide homeostasis under nonstressed and stressed conditions. In this chapter, we provide established protocols to determine the activity of the sulfide releasing enzyme β-cyanoalanine synthase as well as sulfide-consuming enzymes OAS-TL and SDO. Additionally, we describe a reliable and efficient method to purify OAS-TL proteins from plant material.

  4. Pallidol hexaacetate ethyl acetate monosolvate

    Directory of Open Access Journals (Sweden)

    Qinyong Mao

    2013-07-01

    Full Text Available The entire molecule of pallidol hexaacetate {systematic name: (±-(4bR,5R,9bR,10R-5,10-bis[4-(acetyloxyphenyl]-4b,5,9b,10-tetrahydroindeno[2,1-a]indene-1,3,6,8-tetrayl tetraacetate} is completed by the application of twofold rotational symmetry in the title ethyl acetate solvate, C40H34O12·C4H8O2. The ethyl acetate molecule was highly disordered and was treated with the SQUEEZE routine [Spek (2009. Acta Cryst. D65, 148–155]; the crystallographic data take into account the presence of the solvent. In pallidol hexaacetate, the dihedral angle between the fused five-membered rings (r.m.s. deviation = 0.100 Å is 54.73 (6°, indicating a significant fold in the molecule. Significant twists between residues are also evident as seen in the dihedral angle of 80.70 (5° between the five-membered ring and the pendent benzene ring to which it is attached. Similarly, the acetate residues are twisted with respect to the benzene ring to which they are attached [C—O(carboxy—C—C torsion angles = −70.24 (14, −114.43 (10 and −72.54 (13°]. In the crystal, a three-dimensional architecture is sustained by C—H...O interactions which encompass channels in which the disordered ethyl acetate molecules reside.

  5. Determination of tris(2-chloroethyl)phosphate in leather by gas chromatography-mass spectrometry coupled with mixed-mode sorbent solid phase extraction%混合模式吸附剂固相萃取-气相色谱-质谱法测定皮革中的磷酸三(2-氯乙基)酯

    Institute of Scientific and Technical Information of China (English)

    张伟亚; 朱玉玲; 王成云; 李丽霞; 张珺清; 邢钧

    2014-01-01

    磷酸三(2-氯乙基)酯(TCEP)是一种皮革生产中常用的加工助剂,其具有致癌、神经毒性和生殖毒性,被欧洲化学品管理局列入禁用的第二批授权物质清单。由于皮革产品基质复杂,采用常用的固相萃取( SPE)方法提取对TCEP的回收率不高。Silica-WCX是一种自制的含有羧基与烷基的新型混合模式吸附剂。研究表明,通过在酸性条件下使其羧基保持质子化状态,能有效增强 Silica-WCX 对极性化合物 TCEP 的萃取性能,使 TCEP 的回收率得到明显提高。本文以 Silica-WCX为 SPE材料,建立了测定皮革中 TCEP的 SPE-GC-MS方法。该方法的线性范围为0.10~100.0μg/L,定量限( S/N=10)为44.46 ng/kg,不同添加水平下 TCEP的平均回收率在91.45%~99.98%之间,相对标准偏差( RSD)在4.33%~5.97%之间。该方法简便快捷,灵敏度高,定量限低于欧盟《化学品的注册、评估、授权和限制》( registration,evaluation,authorization and restriction of chemicals,REACH)法规的限量要求,适用于皮革及其制品中 TCEP的测定。%Leather is one of the important exporting products to European Union( EU ),and tris(2-chloroethyl)phosphate(TCEP)is a commonly used flame retardant in leather and leath-er products. Recently,TCEP has been classified as a kind of substance of very high concern (SVHC)by EU for its carcinogenicity and reproductive toxicity. But to date,there is not a rec-ognized method for the determination of TCEP in leather and leather products due to the seri-ous matrix interferences and relatively low recovery of TCEP. In this work,a home-made mixed-mode sorbent( Silica-WCX)with carboxyl and alkyl groups was tested as the sorbent of solid phase extraction( SPE ) to extract TECP from leather. The results demonstrated that, making the carboxyl groups protonized under acidic condition,Silica-WCX exhibited better ex-traction performance towards TCEP

  6. 21 CFR 184.1293 - Ethyl alcohol.

    Science.gov (United States)

    2010-04-01

    ... is incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies are... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethyl alcohol. 184.1293 Section 184.1293 Food and... Substances Affirmed as GRAS § 184.1293 Ethyl alcohol. (a) Ethyl alcohol (ethanol) is the chemical C2H5OH....

  7. 40 CFR Appendix Ix to Part 264 - Ground-Water Monitoring List

    Science.gov (United States)

    2010-07-01

    ... acid, 2-chloroethyl 2- -1-methylethyl ester Arsenic (Total) Arsenic Barium (Total) Barium Benzene 71-43...*)- Ethylbenzene 100-41-4 Benzene, ethyl- Ethyl methacrylate 97-63-2 2-Propenoic acid, 2-methyl-, ethyl ester...

  8. Coupling of Alcohols over Alkali-Promoted Cobalt-Molybdenum Sulfide

    DEFF Research Database (Denmark)

    Christensen, Jakob Munkholt; Jensen, Peter Arendt; Schiødt, N.C.;

    2010-01-01

    Double or nothing: Higher alcohols are produced by the hydrogenation of CO with a K-promoted Co-MoS2/C catalyst. Ethanol, which is passed over the sulfide catalyst along with CO and H2, is mainly converted into 1-butanol, which indicates that alcohol condensation contributes to the build-up of hi......Double or nothing: Higher alcohols are produced by the hydrogenation of CO with a K-promoted Co-MoS2/C catalyst. Ethanol, which is passed over the sulfide catalyst along with CO and H2, is mainly converted into 1-butanol, which indicates that alcohol condensation contributes to the build......-up of higher alcohols over the sulfide catalyst. In a nitrogen atmosphere, ethanol is also in part converted into 1-butanol, although ethyl acetate is the major product....

  9. Environmental effect of rapeseed oil ethyl ester

    International Nuclear Information System (INIS)

    Exhaust emission tests were conducted on rapeseed oil methyl ester (RME), rapeseed oil ethyl ester (REE) and fossil diesel fuel as well as on their mixtures. Results showed that when considering emissions of nitrogen oxides (NOx), carbon monoxide (CO) and smoke density, rapeseed oil ethyl ester had less negative effect on the environment in comparison with that of rapeseed oil methyl ester. When fuelled with rapeseed oil ethyl ester, the emissions of NOx showed an increase of 8.3% over those of fossil diesel fuel. When operated on 25-50% bio-ester mixed with fossil diesel fuel, NOx emissions marginally decreased. When fuelled with pure rapeseed oil ethyl ester, HC emissions decreased by 53%, CO emissions by 7.2% and smoke density 72.6% when compared with emissions when fossil diesel fuel was used. Carbon dioxide (CO2) emissions, which cause greenhouse effect, decreased by 782.87 g/kWh when rapeseed oil ethyl ester was used and by 782.26 g/kWh when rapeseed oil methyl ester was used instead of fossil diesel fuel. Rapeseed oil ethyl ester was more rapidly biodegradable in aqua environment when compared with rapeseed oil methyl ester and especially with fossil diesel fuel. During a standard 21 day period, 97.7% of rapeseed oil methyl ester, 98% of rapeseed oil ethyl ester and only 61.3% of fossil diesel fuel were biologically decomposed. (author)

  10. A novel method for improving cerussite sulfidization

    Institute of Scientific and Technical Information of China (English)

    Qi-cheng Feng; Shu-ming Wen; Wen-juan Zhao; Qin-bo Cao; Chao L

    2016-01-01

    Evaluation of flotation behavior, solution measurements, and surface analyses were performed to investigate the effects of chloride ion addition on the sulfidization of cerussite in this study. Micro-flotation tests indicate that the addition of chloride ions prior to sulfidization can significantly increase the flotation recovery of cerussite, which is attributed to the formation of more lead sulfide species on the mineral surface. Solution measurement results suggest that the addition of chloride ions prior to sulfidization induces the transformation of more sul-fide ions from pulp solution onto the mineral surface by the formation of more lead sulfide species. X-ray diffraction and energy-dispersive spectroscopy indicate that more lead sulfide species form on the mineral surface when chloride ions are added prior to sulfidization. These results demonstrate that the addition of chloride ions prior to sulfidization can significantly improve the sulfidization of cerussite, thereby enhancing the flotation performance.

  11. Sulfide intrusion and detoxification in Zostera marina

    DEFF Research Database (Denmark)

    Hasler-Sheetal, Harald; Holmer, Marianne

    2014-01-01

    Sulfide intrusion in seagrasses represents a global threat to seagrasses. In contrast seegrasses grow in hostile sediments, where they are constantly exposed to sulfide intrusion. Little is known about the strategies to survive sulfide intrusion, if there are detoxification mechanisms and sulfur...... nutrition in general. By a global review of sulfide intrusion, coupled with a series of field studies and in situ experiments we elucidate sulfide intrusion and different strategies of seagrasses to sustain sulfide intrusion. Using stable isotope tracing, scanning electron microscopy with x-ray analysis...... to trace sulfur compounds and as well as metabolomics upon sulfide and anoxia exposure we identified different strategies to cope with sulfidic sediments. 1) Avoidance, by reoxidation of gaseous sulfide in the arenchyma to elemental sulfur and sulfate; where precipitation of sulfide occurred as non...

  12. Prevention of sulfide oxidation in sulfide-rich waste rock

    Science.gov (United States)

    Nyström, Elsa; Alakangas, Lena

    2015-04-01

    The ability to reduce sulfide oxidation in waste rock after mine closure is a widely researched area, but to reduce and/or inhibit the oxidation during operation is less common. Sulfide-rich (ca 30 % sulfur) waste rock, partially oxidized, was leached during unsaturated laboratory condition. Trace elements such as As and Sb were relatively high in the waste rock while other sulfide-associated elements such as Cu, Pb and Zn were low compared to common sulfide-rich waste rock. Leaching of unsaturated waste rock lowered the pH, from around six down to two, resulting in continuously increasing element concentrations during the leaching period of 272 days. The concentrations of As (65 mg/L), Cu (6.9 mg/L), Sb (1.2 mg/L), Zn (149 mg/L) and S (43 g/L) were strongly elevated at the end of the leaching period. Different alkaline industrial residues such as slag, lime kiln dust and cement kiln dust were added as solid or as liquid to the waste rock in an attempt to inhibit sulfide oxidation through neo-formed phases on sulfide surfaces in order to decrease the mobility of metals and metalloids over longer time scale. This will result in a lower cost and efforts of measures after mine closure. Results from the experiments will be presented.

  13. Mechanochemical reduction of copper sulfide

    DEFF Research Database (Denmark)

    Balaz, P.; Takacs, L.; Jiang, Jianzhong;

    2002-01-01

    The mechanochemical reduction of copper sulfide with iron was induced in a Fritsch P-6 planetary mill, using WC vial filled with argon and WC balls. Samples milled for specific intervals were analyzed by XRD and Mossbauer spectroscopy. Most of the reaction takes place during the first 10 min...... of milling and only FeS and Cu are found after 60 min. The main chemical process is accompanied by phase transformations of the sulfide phases as a result of milling. Djurleite partially transformed to chalcocite and a tetragonal copper sulfide phase before reduction. The cubic modification of FeS was formed...... first, transforming to hexagonal during the later stages of the process. The formation of off-stoichiometric phases and the release of some elemental sulfur by copper sulfide are also probable....

  14. Pyrophoric nature of iron sulfides

    Energy Technology Data Exchange (ETDEWEB)

    Walker, R. [Univ. of Surrey, Guildford (United Kingdom). Dept. of Materials Science and Engineering; Steele, A.D.; Morgan, D.T.B. [Shell Research Centre Ltd., Chester (United Kingdom). Thornton Research Centre

    1996-05-01

    Hydrogen sulfide, often present in crude oil tankers, can react with rust to form various sulfides including mackinawite (FeS), greigite (Fe{sub 3}S{sub 4}), and pyrite (FeS{sub 2}). The tendency for these compounds to react with oxygen in air to form potentially explosive mixtures depends upon their morphology and the environmental conditions. The experimentally determined heat of oxidation of finely divided mackinawite was {minus}7.45 kJ/g. For samples with a larger particle size and smaller surface area the values measured were lower due to incomplete oxidation of the sulfide. All the sulfides produced, whether from magnetite or acicular, prismatic or spherical geothite, were approximately spherical in form. The heat of oxidation of greigite was found to be approximately {minus}2100 kJ/mol, and the heat of formation of greigite is approximately {minus}320 kJ/mol.

  15. Hydrogen Sulfide Oxidation by Myoglobin.

    Science.gov (United States)

    Bostelaar, Trever; Vitvitsky, Victor; Kumutima, Jacques; Lewis, Brianne E; Yadav, Pramod K; Brunold, Thomas C; Filipovic, Milos; Lehnert, Nicolai; Stemmler, Timothy L; Banerjee, Ruma

    2016-07-13

    Enzymes in the sulfur network generate the signaling molecule, hydrogen sulfide (H2S), from the amino acids cysteine and homocysteine. Since it is toxic at elevated concentrations, cells are equipped to clear H2S. A canonical sulfide oxidation pathway operates in mitochondria, converting H2S to thiosulfate and sulfate. We have recently discovered the ability of ferric hemoglobin to oxidize sulfide to thiosulfate and iron-bound hydropolysulfides. In this study, we report that myoglobin exhibits a similar capacity for sulfide oxidation. We have trapped and characterized iron-bound sulfur intermediates using cryo-mass spectrometry and X-ray absorption spectroscopy. Further support for the postulated intermediates in the chemically challenging conversion of H2S to thiosulfate and iron-bound catenated sulfur products is provided by EPR and resonance Raman spectroscopy in addition to density functional theory computational results. We speculate that the unusual sensitivity of skeletal muscle cytochrome c oxidase to sulfide poisoning in ethylmalonic encephalopathy, resulting from the deficiency in a mitochondrial sulfide oxidation enzyme, might be due to the concentration of H2S by myoglobin in this tissue. PMID:27310035

  16. Demand boom boosts ethyl, butyl acetate

    International Nuclear Information System (INIS)

    US ethyl and butyl acetate markets are being described as 'extremely tight.' One major domestic producer is 'in a sold-out position' and has 'gone on sales control' with respect to these two products. Producers say that sales of both ethyl and butyl acetate have increased during the past year, and industry observers say they expect to see an April 1 price initiative of 2 cts to 3 cts/lb, and possibly a second increase in October. While one producer suggests that this market strength could be 'a sign that the coatings industry is turning around,' most agree that reformulation is the principal driver of growth. Ethyl acetate is said to be replacing methyl ethyl ketone in many formulations, while butyl acetate and butyl acetate blends are substituting for methyl isobutyl ketone. In addition, both ethyl and butyl acetate work as substitutes for xylene and toluene in certain applications. In an effort to conform to the requirements of the Clean Air Act of 1990 and to cooperate with the Environmental Protection Agency's 33/50 voluntary emissions reduction program, coatings manufacturers are moving as quickly as possible to eliminate solvents from their products. And although solvents as a whole will eventually see a dramatic decline in consumption, the temporary beneficiaries of reformulation will be certain of the oxygenated solvents, says Jeff Back, business manager at Kline ampersand Co

  17. Synthesis of furan from allenic sulfide derivatives

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In this paper, we report the synthesis of furan derivatives from allenic sulfides. By the reaction with NaH, β-Hydroxyl allenic sulfides were found to generate furan products in excellent yields with the removal of phenylthio group. β-Aldehyde allenic sulfides were found to give similar furan products with one more substituent when treated with additional nucleophilic reagents. β-ketone allenic sulfides can also cyclize to give furan derivatives with the promotion of P2O5.

  18. Synthesis of furan from allenic sulfide derivatives

    Institute of Scientific and Technical Information of China (English)

    PENG LingLing; ZHANG Xiu; MA Jie; ZHONG ZhenZhen; ZHANG Zhe; ZHANG Yan; WANG JianBo

    2009-01-01

    In this paper, we report the synthesis of furan derivatives from allenic sulfides. By the reaction with NaH.,β-Hydroxyl allenic sulfides were found to generate furan products in excellent yields with the removal of phenylthio group.β-Aldehyde allenic sulfides were found to give similar furan products with one more substituent when treated with additional nucleophilic reagents. β-ketone allenic sulfides can also cyclize to give furan derivatives with the promotion of P2O5.

  19. 30 CFR 250.604 - Hydrogen sulfide.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Hydrogen sulfide. 250.604 Section 250.604... OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Well-Workover Operations § 250.604 Hydrogen sulfide. When a well-workover operation is conducted in zones known to contain hydrogen sulfide (H2S) or...

  20. 30 CFR 250.808 - Hydrogen sulfide.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Hydrogen sulfide. 250.808 Section 250.808... OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Production Safety Systems § 250.808 Hydrogen sulfide. Production operations in zones known to contain hydrogen sulfide (H2S) or in zones where the presence of...

  1. 30 CFR 250.490 - Hydrogen sulfide.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Hydrogen sulfide. 250.490 Section 250.490... OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Hydrogen Sulfide § 250.490 Hydrogen... black lettering as follows: Letter height Wording 12 inches Danger. Poisonous Gas. Hydrogen Sulfide....

  2. 30 CFR 250.504 - Hydrogen sulfide.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Hydrogen sulfide. 250.504 Section 250.504... OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Well-Completion Operations § 250.504 Hydrogen sulfide. When a well-completion operation is conducted in zones known to contain hydrogen sulfide (H2S) or...

  3. Influence of arsenic on iron sulfide transformations

    NARCIS (Netherlands)

    Wolthers, M.; Butler, I.B.; Rickard, D.

    2007-01-01

    The association of arsenate, As(V), and arsenite, As(III), with disordered mackinawite, FeS, was studied in sulfide-limited (Fe:S = 1:1) and excess-sulfide (Fe:S = 1:2) batch experiments. In the absence of arsenic, the sulfide-limited experiments produce disordered mackinawite while the excess-sulfi

  4. Solid acid catalysed formation of ethyl levulinate and ethyl glucopyranoside from mono- and disaccharides

    DEFF Research Database (Denmark)

    Shunmugavel, Saravanamurugan; Riisager, Anders

    2012-01-01

    Sulfonic acid functionalised SBA-15 (SO3H-SBA-15), sulfated zirconia and beta, Y, ZSM-5 and mordenite zeolite catalysts have been applied for the dehydration of sugars to ethyl levulinate and ethyl-D-glucopyranoside (EDGP) using ethanol as solvent and reactant. The SO3H-SBA-15 catalyst showed a...... high catalytic activity for the selective conversion of fructose to ethyl levulinate (57%) and glucose to EDGP (80%) at 140 °C, whereas the disaccharide sucrose yielded a significant amount of both products. The SO3H-SBA-15 catalysts were found to be highly active compared to the zeolites under...

  5. STUDY OF HYDROGEN SULFIDE REMOVAL FROM GROUNDWATER

    Directory of Open Access Journals (Sweden)

    T. Lupascu

    2013-06-01

    Full Text Available The process of the hydrogen sulfide removal from the underground water of the Hancesti town has been investigated. By oxygen bubbling through the water containing hydrogen sulfide, from the Hancesti well tube, sulfur is deposited in the porous structure of studied catalysts, which decreases their catalytic activity. Concomitantly, the process of adsorption / oxidation of hydrogen sulfide to sulfate take place. The kinetic research of the hydrogen sulfide removal from the Hancesti underground water, after its treatment by hydrogen peroxide, proves greater efficiency than in the case of modified carbonic adsorbents. As a result of used treatment, hydrogen sulfide is completely oxidized to sulfates

  6. Fierce Competition in China's Ethyl Acetate Market

    Institute of Scientific and Technical Information of China (English)

    Wang Zichang

    2007-01-01

    @@ Ethyl acetate is used extensively in the coatings, inks, pharmaceuticals,adhesives, cosmetics and organic synthesis sectors. With the sustained stable growth of China's national economy, the construction and automobile sectors are developing rapidly and environmental protection laws and regulations are becoming stricter.

  7. 2-Ethyl-6-methylanilinium 4-methylbenzenesulfonate

    Directory of Open Access Journals (Sweden)

    Jiao Ye

    2009-02-01

    Full Text Available The title compound, C9H14N+·C7H7SO3−, contains a 2-ethyl-6-methylanilinium cation and a 4-methylbenzenesulfonic anion. The cations are anchored between the anions through N—H...O hydrogen bonds. Electrostatic and van der Waals interactions, as well as hydrogen bonds, maintain the structural cohesion.

  8. Study of the Reaction Cl + Ethyl Formate at 700-950 Torr and 297 to 435 K: Product Distribution and the Kinetics of the Reaction C2H5OC(═O) → CO2 + C2H5.

    Science.gov (United States)

    Kaiser, E W

    2016-05-26

    The kinetics and mechanism of the reaction of atomic chlorine with ethyl formate [Cl + CH3CH2O(C═O)H, reaction 1] have been examined. These experiments were performed at pressures of 760-950 Torr and temperatures from 297 to 435 K. Reactants and products were quantified by gas chromatography-flame ionization detector (GC/FID) analysis. The initial mixture contained ethyl formate, Cl2, and N2. Cl atoms were generated by UV photolysis of this initial mixture at 360 nm, which dissociates Cl2. The rate constant of reaction 1 was measured at 297 K relative to that of the reaction Cl + C2H5Cl (reaction 2), yielding the rate constant ratio k1/k2 = 1.09 ± 0.05. The final products formed from reaction 1 are ethyl chloroformate, 1-chloroethyl formate, and 2-chloroethyl formate. These products result from the reactions with Cl2 of the three free radicals formed by H atom abstraction from ethylformate in reaction 1. Based on the molar yields of these three chlorinated products, the yields of the three radicals formed from reaction 1 at 297 K are (25 ± 3) mole percent of CH3CH2O(C═O); (67 ± 5) mole percent of CH3CHO(C═O)H; and (8 ± 2) mole percent of CH2CH2O(C═O)H. A second phase of this experiment measured the rate constant of the decarboxylation of the ethoxy carbonyl radical [CH3CH2O(C═O) → CO2 + C2H5, reaction 4] relative to the rate constant of its reaction with Cl2 [CH3CH2O(C═O) + Cl2 → CH3CH2O(C═O)Cl + Cl, reaction 3a]. Over the temperature range 297 to 404 K at 1 atm total pressure, this ratio can be expressed by k4/k3a = 10(23.56±0.22) e(-(12700±375)/RT) molecules cm(-3). Estimating the value of k3a (which has not been measured) based on similar reactions, the expression k4 = 5.8 × 10(12) e(-(12700)/RT) s(-1) is obtained. The estimated error of this rate constant is ± a factor of 2 over the experimental temperature range. This rate expression is compared with recent ab initio calculations of the decarboxylation of the analogous methoxy

  9. Sulfide intrusion and detoxification in seagrasses ecosystems

    DEFF Research Database (Denmark)

    Hasler-Sheetal, Harald; Holmer, Marianne

    Sulfide intrusion in seagrasses represents a global threat to seagrasses and thereby an important parameter in resilience of seagrass ecosystems. In contrast seegrasses colonize and grow in hostile sediments, where they are constantly exposed to invasion of toxic gaseous sulfide. Remarkably little...... is known about the strategies of seagrasses to survive sulfide intrusion, their potential detoxification mechanisms and sulfur nutrition in general. By a global review of sulfide intrusion, coupled with a series of field studies and in situ experiments we elucidate sulfide intrusion and different...... strategies of seagrasses to sustain sulfide intrusion. Using stable isotope tracing, scanning electron microscopy with x-ray analysis, tracing sulfur compounds combined with ecosystem parameters we found different spatial, intraspecific and interspecific strategies to cope with sulfidic sediments. 1...

  10. Synthesis of 7-Ethyl-10-hydroxycamptothecin and Proposed Reaction Mechanism

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The improved 3-step preparation of a key antitumor agent, 7-ethyl-10-hydroxycamptothecin(SN-38), which consists of ethylation, oxidation and photo-chemical rearrangement, is described. The proposed reaction mechanism is also discussed.

  11. Interação de glyphosate com carfentrazone-ethyl Glyphosate - carfentrazone-ethyl interaction

    OpenAIRE

    R.C. Werlang; Silva, A. A.

    2002-01-01

    Foi conduzido um experimento em condições controladas para determinar a interação do carfentrazone-ethyl em mistura no tanque com o herbicida glyphosate, no controle de seis espécies de plantas daninhas. Glyphosate aplicado isoladamente na dose de 720 g ha-1 foi eficaz no controle de Amaranthus hybridus (100%), Desmodium tortuosum (100%), Bidens pilosa (99%), Eleusine indica (96%), Digitaria horizontalis (100%) e Commelina benghalensis (93%) aos 21 DAA. Carfentrazone-ethyl aplicado isoladamen...

  12. Redox Biochemistry of Hydrogen Sulfide*

    OpenAIRE

    Kabil, Omer; Banerjee, Ruma

    2010-01-01

    H2S, the most recently discovered gasotransmitter, might in fact be the evolutionary matriarch of this family, being both ancient and highly reduced. Disruption of γ-cystathionase in mice leads to cardiovascular dysfunction and marked hypertension, suggesting a key role for this enzyme in H2S production in the vasculature. However, patients with inherited deficiency in γ-cystathionase apparently do not present vascular pathology. A mitochondrial pathway disposes sulfide and couples it to oxid...

  13. Clean production of methyl ethyl ketone (MEK)

    International Nuclear Information System (INIS)

    Methyl ethyl ketone oxime (MEKO) was obtained by reaction of methyl ethyl ketone (MEK) with ammonia and hydrogen peroxide using titanium silicalite-1 (TS-1) as catalyst. The effect of reaction temperature, type of solvent, molar ratios of NH3/MEK, H2O2/MEK and mg catalyst/mmol MEK ratio was studied. Water was the most appropriate solvent to obtain high selectivity to oxime. 100% selectivity to MEKO and 60% conversion of MEK was obtained at 70 Celsius degrade using the following parameters: H2O2/MEK = 0,7 and NH3/MEK = 1,12. mg.catalyst/mmol MEK = 10,5. Little decrease in the catalytic activity was observed after reusing the catalysts twice suggesting that incorporated Ti in the MFI structure is rather stable under the studied conditions

  14. Synthesis of Ethyl Salicylate Using Household Chemicals

    Science.gov (United States)

    Solomon, Sally; Hur, Chinhyu; Lee, Alan; Smith, Kurt

    1996-02-01

    Ethyl salicylate is synthesized, isolated, and characterized in a three-step process using simple equipment and household chemicals. First, acetylsalicylic acid is extracted from aspirin tablets with isopropyl alcohol, then hydrolyzed to salicylic acid with muriatic acid, and finally, the salicylic acid is esterified using ethanol and a boric acid catalyst. The experiment can be directed towards high school or university level students who have sufficient background in organic chemistry to recognize the structures and reactions that are involved.

  15. Chemical and thermochemical aspects of the ozonolysis of ethyl oleate: decomposition enthalpy of ethyl oleate ozonide.

    Science.gov (United States)

    Cataldo, Franco

    2013-01-01

    Neat ethyl oleate was ozonized in a bubble reactor and the progress of the ozonolysis was followed by infrared (FT-IR) spectroscopy and by the differential scanning calorimetry (DSC). The ozonolysis was conducted till a molar ratio O3/C=C≈1 when the exothermal reaction spontaneously went to completion. A specific thermochemical calculation on ethyl oleate ozonation has been made to determine the theoretical heat of the ozonization reaction using the group increment approach. A linear relationship was found both in the integrated absorptivity of the ozonide infrared band at 1110 cm(-1) and the ozonolysis time as well as the thermal decomposition enthalpy of the ozonides and peroxides formed as a result of the ozonation. The DSC decomposition temperature of ozonated ethyl oleate occurs with an exothermal peak at about 150-155 °C with a decomposition enthalpy of 243.0 kJ/mol at molar ratio O3/C=C≈1. It is shown that the decomposition enthalpy of ozonized ethyl oleate is a constant value (≈243 kJ/mol) at any stage of the O3/C=C once an adequate normalization of the decomposition enthalpy for the amount of the adsorbed ozone is taken into consideration. The decomposition enthalpy of ozonized ethyl oleate was also calculated using a simplified thermochemical model, obtaining a result in reasonable agreement with the experimental value.

  16. Chemical and thermochemical aspects of the ozonolysis of ethyl oleate: decomposition enthalpy of ethyl oleate ozonide.

    Science.gov (United States)

    Cataldo, Franco

    2013-01-01

    Neat ethyl oleate was ozonized in a bubble reactor and the progress of the ozonolysis was followed by infrared (FT-IR) spectroscopy and by the differential scanning calorimetry (DSC). The ozonolysis was conducted till a molar ratio O3/C=C≈1 when the exothermal reaction spontaneously went to completion. A specific thermochemical calculation on ethyl oleate ozonation has been made to determine the theoretical heat of the ozonization reaction using the group increment approach. A linear relationship was found both in the integrated absorptivity of the ozonide infrared band at 1110 cm(-1) and the ozonolysis time as well as the thermal decomposition enthalpy of the ozonides and peroxides formed as a result of the ozonation. The DSC decomposition temperature of ozonated ethyl oleate occurs with an exothermal peak at about 150-155 °C with a decomposition enthalpy of 243.0 kJ/mol at molar ratio O3/C=C≈1. It is shown that the decomposition enthalpy of ozonized ethyl oleate is a constant value (≈243 kJ/mol) at any stage of the O3/C=C once an adequate normalization of the decomposition enthalpy for the amount of the adsorbed ozone is taken into consideration. The decomposition enthalpy of ozonized ethyl oleate was also calculated using a simplified thermochemical model, obtaining a result in reasonable agreement with the experimental value. PMID:23969233

  17. Theoretical study of the decomposition of ethyl and ethyl 3-phenyl glycidate.

    Science.gov (United States)

    Josa, Daniela; Peña-Gallego, Angeles; Rodríguez-Otero, Jesús; Cabaleiro-Lago, Enrique M

    2013-01-01

    The mechanism of the decomposition of ethyl and ethyl 3-phenyl glycidate in gas phase was studied by density functional theory (DFT) and MP2 methods. A proposed mechanism for the reaction indicates that the ethyl side of the ester is eliminated as ethylene through a concerted six-membered cyclic transition state, and the unstable intermediate glycidic acid decarboxylates rapidly to give the corresponding aldehyde. Two possible pathways for glycidic acid decarboxylation were studied: one via a five-membered cyclic transition state, and the other via a four-membered cyclic transition state. The results of the calculations indicate that the decarboxylation reaction occurs via a mechanism with five-membered cyclic transition state.

  18. Pulse radiolysis of aqueous solutions of ethyl acrylate and hydroxy ethyl acrylate

    Science.gov (United States)

    Safrany, A.; Biro, A.; Wojnarovits, L.

    1993-10-01

    Ethyl- and hydroxy ethyl acrylate show high reactivities with hydrated electron and hydroxyl radical intermediates of water radiolysis. The electron adduct reversibly protonate with pK values of 5.7 and 7.3. The adducts may take part in irreversible protonation at the β carbon atom forming α-carboxyl alkyl radicals. Same type of radical forms in reaction of acrylates with OH: at low concentration the adduct mainly disappear in self termination reactions. Above 5 mmol dm -1 the signals showed the startup of oligomerization.

  19. Kinetic Studies of Sulfide Mineral Oxidation and Xanthate Adsorption

    OpenAIRE

    Mendiratta, Neeraj K.

    2000-01-01

    Sulfide minerals are a major source of metals; however, certain sulfide minerals, such as pyrite and pyrrhotite, are less desirable. Froth flotation is a commonly used separation technique, which requires the use of several reagents to float and depress different sulfide minerals. Xanthate, a thiol collector, has gained immense usage in sulfide minerals flotation. However, some sulfides are naturally hydrophobic and may float without a collector. Iron sulfides, such as pyrite and pyrrho...

  20. Hydrogen sulfide and vascular relaxation

    Institute of Scientific and Technical Information of China (English)

    SUN Yan; TANG Chao-shu; DU Jun-bao; JIN Hong-fang

    2011-01-01

    Objective To review the vasorelaxant effects of hydrogen sulfide (H2S) in arterial rings in the cardiovascular system under both physiological and pathophysiological conditions and the possible mechanisms involved.Data sources The data in this review were obtained from Medline and Pubmed sources from 1997 to 2011 using the search terms "hydrogen sulfide" and ""vascular relaxation".Study selection Articles describing the role of hydrogen sulfide in the regulation of vascular activity and its vasorelaxant effects were selected.Results H2S plays an important role in the regulation of cardiovascular tone.The vasomodulatory effects of H2S depend on factors including concentration,species and tissue type.The H2S donor,sodium hydrosulfide (NarS),causes vasorelaxation of rat isolated aortic rings in a dose-dependent manner.This effect was more pronounced than that observed in pulmonary arterial rings.The expression of KATP channel proteins and mRNA in the aortic rings was increased compared with pulmonary artery rings.H2S is involved in the pathogenesis of a variety of cardiovascular diseases.Downregulation of the endogenous H2S pathway is an important factor in the pathogenesis of cardiovascular diseases.The vasorelaxant effects of H2S have been shown to be mediated by activation of KATP channels in vascular smooth muscle cells and via the induction of acidification due to activation of the CI/HCO3 exchanger.It is speculated that the mechanisms underlying the vasoconstrictive function of H2S in the aortic rings involves decreased NO production and inhibition of cAMP accumulation.Conclusion H2S is an important endogenous gasotransmitter in the cardiovascular system and acts as a modulator of vascular tone in the homeostatic regulation of blood pressure.

  1. Interação de glyphosate com carfentrazone-ethyl Glyphosate - carfentrazone-ethyl interaction

    Directory of Open Access Journals (Sweden)

    R.C. Werlang

    2002-04-01

    Full Text Available Foi conduzido um experimento em condições controladas para determinar a interação do carfentrazone-ethyl em mistura no tanque com o herbicida glyphosate, no controle de seis espécies de plantas daninhas. Glyphosate aplicado isoladamente na dose de 720 g ha-1 foi eficaz no controle de Amaranthus hybridus (100%, Desmodium tortuosum (100%, Bidens pilosa (99%, Eleusine indica (96%, Digitaria horizontalis (100% e Commelina benghalensis (93% aos 21 DAA. Carfentrazone-ethyl aplicado isoladamente controlou eficazmente C. benghalensis. As misturas de glyphosate nas doses de 252 e 720 g ha-1 com carfentrazone-ethyl nas doses de 15 e 30 g ha¹ demonstraram efeito aditivo no controle de A. hybridus, D. tortuosum e Bidens pilosa, à exceção das misturas de glyphosate na dose de 252 g ha-1 com as doses de 15 e 30 g ha-1 de carfentrazone-ethyl, que proporcionam efeito sinergístico no controle de D. tortuosum. A adição das duas doses de carfentrazone-ethyl antagonizou o efeito de glyphosate na menor dose (252 g ha-1 no controle de E. indica, apresentando, no entanto, efeito aditivo com o glyphosate na maior dose (720 g ha-1. Já para D. horizontalis, as misturas de carfentrazone-ethyl com glyphosate na menor dose (252 g ha-1 apresentaram efeito sinergístico no controle dessa espécie, demonstrando, ainda, efeito aditivo na mistura com glyphosate na dose de 720 g ha-1. A mistura de carfentrazone-ethyl com glyphosate proporcionou efeito aditivo no controle de C. benghalensis, independentemente das combinações de doses avaliadas. Os resultados deste experimento indicam que carfentrazone-ethyl apresenta comportamento diferenciado quanto à interação com glyphosate, dependendo da espécie de planta daninha e da dose dos herbicidas utilizados na mistura em tanque, sendo complementar na mistura em tanque com glyphosate, pois demonstrou efeito antagônico em poucas das combinações estudadas, prevalecendo seu efeito aditivo na mistura com glyphosate, no

  2. Variation in sulfide tolerance of photosystem II in phylogenetically diverse cyanobacteria from sulfidic habitats

    Science.gov (United States)

    Miller, Scott R.; Bebout, Brad M.

    2004-01-01

    Physiological and molecular phylogenetic approaches were used to investigate variation among 12 cyanobacterial strains in their tolerance of sulfide, an inhibitor of oxygenic photosynthesis. Cyanobacteria from sulfidic habitats were found to be phylogenetically diverse and exhibited an approximately 50-fold variation in photosystem II performance in the presence of sulfide. Whereas the degree of tolerance was positively correlated with sulfide levels in the environment, a strain's phenotype could not be predicted from the tolerance of its closest relatives. These observations suggest that sulfide tolerance is a dynamic trait primarily shaped by environmental variation. Despite differences in absolute tolerance, similarities among strains in the effects of sulfide on chlorophyll fluorescence induction indicated a common mode of toxicity. Based on similarities with treatments known to disrupt the oxygen-evolving complex, it was concluded that sulfide toxicity resulted from inhibition of the donor side of photosystem II.

  3. New biologically active hydrogen sulfide donors.

    Science.gov (United States)

    Roger, Thomas; Raynaud, Francoise; Bouillaud, Frédéric; Ransy, Céline; Simonet, Serge; Crespo, Christine; Bourguignon, Marie-Pierre; Villeneuve, Nicole; Vilaine, Jean-Paul; Artaud, Isabelle; Galardon, Erwan

    2013-11-25

    Generous donors: The dithioperoxyanhydrides (CH3 COS)2 , (PhCOS)2 , CH3 COSSCO2 Me and PhCOSSCO2 Me act as thiol-activated hydrogen sulfide donors in aqueous buffer solution. The most efficient donor (CH3 COS)2 can induce a biological response in cells, and advantageously replace hydrogen sulfide in ex vivo vascular studies. PMID:24115650

  4. Sulfide stress cracking of pipeline steels

    International Nuclear Information System (INIS)

    The problem of the sulfide stress corrosion cracking of pipeline steels and their welded joints have been presented for pipeline steels. Results of hydrogen sulfide stress cracking inhibitors and corrosion inhibitors of three types protective actions on pipeline steels of two grades petroleum range of products are given. (author)

  5. Ammonia and hydrogen sulfide removal using biochar

    Science.gov (United States)

    Reducing ammonia and hydrogen sulfide emissions from livestock facilities is an important issue for many communities and livestock producers. Ammonia has been regarded as odorous, precursor for particulate matter (PM), and contributed to livestock mortality. Hydrogen sulfide is highly toxic at elev...

  6. Sulfide toxicity kinetics of a uasb reactor

    Directory of Open Access Journals (Sweden)

    D. R. Paula Jr.

    2009-12-01

    Full Text Available The effect of sulfide toxicity on kinetic parameters of anaerobic organic matter removal in a UASB (up-flow anaerobic sludge blanket reactor is presented. Two lab-scale UASB reactors (10.5 L were operated continuously during 12 months. The reactors were fed with synthetic wastes prepared daily using glucose, ammonium acetate, methanol and nutrient solution. One of the reactors also received increasing concentrations of sodium sulfide. For both reactors, the flow rate of 16 L.d-1 was held constant throughout the experiment, corresponding to a hydraulic retention time of 15.6 hours. The classic model for non-competitive sulfide inhibition was applied to the experimental data for determining the overall kinetic parameter of specific substrate utilization (q and the sulfide inhibition coefficient (Ki. The application of the kinetic parameters determined allows prediction of methanogenesis inhibition and thus the adoption of operating parameters to minimize sulfide toxicity in UASB reactors.

  7. Crystal structure of 6-chloro-5-(2-chloroethyl-3-(propan-2-ylideneindolin-2-one

    Directory of Open Access Journals (Sweden)

    K. R. Roopashree

    2015-08-01

    Full Text Available The title compound, C13H13Cl2NO, has a 3-(propan-2-ylideneindolin-2-one core with a Cl atom and a chloroethyl substituent attached to the aromatic ring. Two atoms of the aromatic ring and the chloroethyl substituent atoms are disordered over two sets of sites with a refined occupancy ratio of 0.826 (3:0.174 (3. In the crystal, molecules are linked by pairs of N—H...O hydrogen bonds, forming inversion dimers with an R22(8 ring motif.

  8. 2-Chloroethyl 2-(5-bromo-3-methylsulfinyl-1-benzofuran-2-ylacetate

    Directory of Open Access Journals (Sweden)

    Uk Lee

    2009-05-01

    Full Text Available In the title compound, C13H12BrClO4S, the O atom and the methyl group of the methylsulfinyl substituent lie on opposite sides of the plane of the benzofuran fragment. There is a mean deviation of 0.016 (4 Å from the least-squares plane defined by the nine constituent benzofuran atoms. The crystal structure is stabilized by aromatic π–π interactions between the benzene rings of neighbouring molecules [centroid–centroid distance = 3.689 (7 Å]and by a weak C—H...π interaction between an H atom of the methylene group bonded to the carboxylate O atom and the benzene ring of an adjacent molecule. In addition, the crystal structure exhibits weak non-classical intermolecular C—H...O hydrogen bonds. The chloroethyl group is disordered over two positions, with refined site-occupancy factors of 0.767 (6 and 0.233 (6.

  9. Going the distance with ethyl alcohol

    International Nuclear Information System (INIS)

    If all had gone according to plan, ethyl alcohol would be in the driver's seat now, cruising down the highway and getting ready to speed into high gear. Instead, this renewable fuel, chemical reagent and solvent is navigating a complex obstacle course, watching warily for sharp turns and mixed signals. Globally, the supply and demand for all grades of ethyl alcohol is awry. Production of industrial-grade material is running at full throttle and prices are going up. Much of the upheaval over ethanol can be traced to the US Environmental Protection Agency and the renewable oxygenate standard (ROS) of the Clean Air Act. Under ROS, 15% of oxygenates used in gasoline sold this year was to be derived from a renewable source. Next month, that percentage was to have been doubled to 30%. Enticed by projections of upwards of 2 billion gal/yr of fermentation alcohol to comply with ROS, producers rushed to expand capacity. But to the producers' dismay, EPA was forced to backpedal on ROS. When representatives of the petroleum industry filed suit and won a stay, EPA rescinded its ROS regulation and ethanol producers were left in the lurch. High prices for corn is also putting the squeeze on inventories of industrial alcohol. Synthetic ethanol production, from ethylene for example, is booming, however. This paper discusses the ethanol market factors

  10. Primordial Xenon in Allende Sulfides

    Science.gov (United States)

    Lee, J. T.; Manuel, O. K.

    1995-09-01

    The Allende C3V carbonaceous chondrite incorporated isotopically anomalous components of several medium-heavy elements (Z=36-62) from nucleosynthesis [1]. Isotopically distinct Xe (Z=54) has been found in grains ranging from several _ to a few mm in size. Diamond [2] is the host of Xe that is enriched in isotopes produced by the very rapid p- and r-processes in a supernova explosion [3]. Silicon carbide [4] is the host of Xe that is enriched in the middle isotopes, 128-132Xe, produced by slow neutron capture [3] before a star reaches the supernova stage. The present study was undertaken to identify the isotopic composition of primitive Xe initially trapped in sulfides of the Allende meteorite. Two FeS mineral separates were analyzed by stepwise heating. One sample was first irradiated in a neutron flux to generate a tracer isotope, 131*Xe, by the 130Te(n, gamma beta-)131*Xe reaction. The release pattern of this tracer isotope, 131*Xe, closely paralleled the release of primordial 132Xe up to 950 degrees C, when the sulfide melted and released the bulk of its trapped Xe (Figure 1). The Xe released from both samples at 950 deg C was terrestrial in isotopic composition, except for enrichments from spallogenic and radiogenic components (Figure 2). From the results of this and earlier analyses of Xe in meteoritic FeS [5, 6, 7], we conclude that terrestrial-type Xe was dominant in the central region of the protoplanetary nebula, and it remains a major component in the FeS of diverse meteorites and in the terrestrial planets that are rich in Fe, S [8]. References: [1] Begemann F. (1993) Origin and Evolution of the Elements (N. Prantzos et al., eds.), 518-527, Cambridge Univ. [2] Lewis R. S. and Anders E. (1988) LPS XIX, 679-680. [3] Burbidge et al. (1957) Rev. Modern Phys., 29, 547-650. [4] Tang M. and Anders E. (1988) GCA, 52, 1235-1244. [5] Niemeyer S. (1979) GCA, 43, 843-860. [6] Lewis et al. (1979) GCA, 43, 1743-1752. [7] Hwaung G. and Manuel O. K. (1982) Nature, 299

  11. Pelletizing of sulfide molybdenite concentrates

    Science.gov (United States)

    Palant, A. A.

    2007-04-01

    The results of a pelletizing investigation using various binding components (water, syrup, sulfite-alcohol distillery grains, and bentonite) of the flotation sulfide molybdenite concentrate (˜84% MoS2) from the Mongolian deposit are discussed. The use of syrup provides rather high-strength pellets (>3 N/pellet or >300 g/pellet) of the required size (2 3 mm) for the consumption of 1 kg binder per 100 kg concentrate. The main advantage of the use of syrup instead of bentonite is that the molybdenum cinder produced by oxidizing roasting of raw ore materials is not impoverished due to complete burning out of the syrup. This fact exerts a positive effect on the subsequent hydrometallurgical process, decreasing molybdenum losses related to dump cakes.

  12. Adequate hydrogen sulfide, healthy circulation

    Institute of Scientific and Technical Information of China (English)

    DU Jun-bao; CHEN Stella; JIN Hong-fang; TANG Chao-shu

    2011-01-01

    Previously,hydrogen sulfide (H2S) was considered to be a toxic gas.However,recently it was discovered that it could be produced in mammals and even in plants,throughtheproductionandmetabolismof sulfur-containing amino acids.In mammals,H2S is mainly catalyzed by cystathionine-γ-lyase (CSE),cystathionin-β-lyase (CBS) and 3-mercaptopyruvate sulfurtransferase (MPST) with the substrate of L-cysteine.Endogenous H2S exerts many important physiological and pathophysiological functions,including hypotensive action,vasorelaxation,myocardial dilation,inhibition of smooth muscle cell proliferation,and antioxidatve actions.Importantly,it plays a very important role in the pathogenesis of systemic hypertension,pulmonary hypertension,atherosclerosis,myocardialinjury,angiogenesis,hyperhomocysteinemi aandshock.Therefore,H2S is now being considered to be a novel gasotransmitter after nitric oxide and carbon monoxide in the regulation of circulatory system.

  13. Structural studies in limestone sulfidation

    Energy Technology Data Exchange (ETDEWEB)

    Fenouil, L.A.; Lynn, S.

    1993-05-01

    This study investigates the sulfidation of limestone at high temperatures (700--900{degree}C) as the first step in the design of a High-Temperature Coal-Gas Clean-Up system using millimeter-size limestone particles. Several workers have found that the rate of this reaction significantly decreases after an initial 10 to 15% conversion of CaCO{sub 3} to CaS. The present work attempts to explain this feature. It is first established that millimeter-size limestone particles do not sinter at temperatures up to the CaCO{sub 3} calcination point (899{degree}C at 1.03 bar CO{sub 2} partial pressure). It is then shown that CaS sinters rapidly at 750 to 900{degree}C if CO{sub 2} is present in the gas phase. Scanning Electron Microscope (SEM) photographs and Electron Dispersive Spectroscopy (EDS) data reveal that the CaS product layer sinters and forms a quasi-impermeable coating around the CaCO{sub 3} grains that greatly hinders more H{sub 2}S from reaching the still unreacted parts of the stone. Moreover, most of the pores initially present within the limestone structure begin to disappear or, at least, are significantly reduced in size. From then on, subsequent conversion is limited by diffusion of H{sub 2}S through the CaS layer, possibly by S{sup 2{minus}} ionic diffusion. The kinetics is then adequately described by a shrinking-core model, in which a sharp front of completely converted limestone is assumed to progress toward the center of the pellet. Finally, experimental evidence and computer simulations using simple sintering models suggest that the CaS sintering, responsible for the sharp decrease in the sulfidation rate, is surface-diffusion controlled.

  14. Microbial control of hydrogen sulfide production

    Energy Technology Data Exchange (ETDEWEB)

    Montgomery, A.D.; Bhupathiraju, V.K.; Wofford, N.; McInerney, M.J. [Univ. of Oklahoma, Tulsa, OK (United States)] [and others

    1995-12-31

    A sulfide-resistant strain of Thiobacillus denitrificans, strain F, prevented the accumulation of sulfide by Desulfovibrio desulfuricans when both organisms were grown in liquid medium. The wild-type strain of T. denitrificans did not prevent the accumulation of sulfide produced by D. desulfuricans. Strain F also prevented the accumulation of sulfide by a mixed population of sulfate-reducing bacteria enriched from an oil field brine. Fermentation balances showed that strain F stoichiometrically oxidized the sulfide produced by D. desulfuricans and the oil field brine enrichment to sulfate. The ability of a strain F to control sulfide production in an experimental system of cores and formation water from the Redfield, Iowa, natural gas storage facility was also investigated. A stable, sulfide-producing biofilm was established in two separate core systems, one of which was inoculated with strain F while the other core system (control) was treated in an identical manner, but was not inoculated with strain F. When formation water with 10 mM acetate and 5 mM nitrate was injected into both core systems, the effluent sulfide concentrations in the control core system ranged from 200 to 460 {mu}M. In the test core system inoculated with strain F, the effluent sulfide concentrations were lower, ranging from 70 to 110 {mu}M. In order to determine whether strain F could control sulfide production under optimal conditions for sulfate-reducing bacteria, the electron donor was changed to lactate and inorganic nutrients (nitrogen and phosphate sources) were added to the formation water. When nutrient-supplemented formation water with 3.1 mM lactate and 10 mM nitrate was used, the effluent sulfide concentrations of the control core system initially increased to about 3,800 {mu}M, and then decreased to about 1,100 {mu}M after 5 weeks. However, in the test core system inoculated with strain F, the effluent sulfide concentrations were much lower, 160 to 330 {mu}M.

  15. Iron-sulfide crystals in probe deposits

    DEFF Research Database (Denmark)

    Laursen, Karin; Frandsen, Flemming

    1998-01-01

    Iron-sulfides were observed in deposits collected on a probe inserted at the top of the furnace of a coal-fired power station in Denmark. The chemical composition of the iron-sulfides is equivalent to pyrrhotite (FeS). The pyrrhotites are present as crystals and, based on the shape of the crystals......: (1) impact of low viscous droplets of iron sulfide; and (2) sulfur diffusion. Previous research on the influence of pyrite on slagging focused on the decomposition of pyrite into pyrrhotite and especially on the oxidation stage of this product during impact on the heat transfer surfaces...

  16. Phase Engineering of 2D Tin Sulfides.

    OpenAIRE

    Mutlu, Z; Wu, RJ; Wickramaratne, D.; Shahrezaei, S; Liu, C; Temiz, S; Patalano, A; M Ozkan; Lake, RK; Mkhoyan, KA; Ozkan, CS

    2016-01-01

    Tin sulfides can exist in a variety of phases and polytypes due to the different oxidation states of Sn. A subset of these phases and polytypes take the form of layered 2D structures that give rise to a wide host of electronic and optical properties. Hence, achieving control over the phase, polytype, and thickness of tin sulfides is necessary to utilize this wide range of properties exhibited by the compound. This study reports on phase-selective growth of both hexagonal tin (IV) sulfide SnS2...

  17. Production of ethyl alcohol from corn silage

    Energy Technology Data Exchange (ETDEWEB)

    Pieper, H.J.; Ponitz, H.

    1973-01-01

    Corn silage may be employed as a raw material for the production of ethyl alcohol when starch is first cracked by pressure cooking and subsequently saccharified by microbial amalyses. Cracking conditions are: pressure increase 1.6 atmosphere within 60 minutes; maximum maintained for 35 minutes. The fermentation is complete after 72 hours. Extract decreases of fermented mashes made from corn silage are less than when dried corn is used. In the most advantageous case the degree of fermentation was -0.2 weight % of the extract. The maximum yields of alcohol were 26.0.1. pure alcohol/100 kg corn silage and 61.2.1. pure alcohol/100 kg starch. The latter is 3.9.1. pure alcohol lower than when dried corn was used. Despite the high bacterial infection of corn silage practically infection-free processing is assured.

  18. Sulfide Intrusion and Detoxification in the Seagrass Zostera marina

    DEFF Research Database (Denmark)

    Hasler-Sheetal, Harald; Holmer, Marianne

    2015-01-01

    Gaseous sulfide intrusion into seagrasses growing in sulfidic sediments causes little or no harm to the plant, indicating the presence of an unknown sulfide tolerance or detoxification mechanism. We assessed such mechanism in the seagrass Zostera marina in the laboratory and in the field...... as sulfate throughout the plant. We conclude that avoidance of sulfide exposure by reoxidation of sulfide in the rhizosphere or aerenchyma and tolerance of sulfide intrusion by incorporation of sulfur in the plant are likely major survival strategies of seagrasses in sulfidic sediments....

  19. 2,6-Bis(9-ethyl-9H-carbazolylmethylenecyclohexanone

    Directory of Open Access Journals (Sweden)

    Abdullah M. Asiri

    2009-10-01

    Full Text Available The title compound, 2,6-bis(ethyl-9-ethyl-9H-carbazolylmethylenecyclohexanone has been synthesized by condensation of 9-ethylcarbazole-3-aldehyde and cyclohexanone in ethanol in the presence of pyridine. The structure of this new compound was confirmed by elemental analysis, IR, 1H NMR, 13C NMR and EI-MS spectral analysis.

  20. Solvent-free synthesis of some ethyl arylglyoxylates

    Institute of Scientific and Technical Information of China (English)

    Ji Ming Xiang; Bao Lin Li

    2009-01-01

    An efficient and convenient approach to synthesize of ethyl arylglyoxylates by solvent-free grinding was described. Eight ethyl arylglyoxylates had been synthesized by this method, this method provided several advantages such as little pollution, high yield, good selectivity, and simple workup procedure, their structures were confirmed by IR, 1HNMR.

  1. Formation of Copper Sulfide Artifacts During Electrolytic Dissolution of Steel

    Science.gov (United States)

    Tan, Jia; Pistorius, P. Chris

    2013-06-01

    Based on equilibrium considerations, copper sulfide is not expected to form in manganese-containing steel, yet previous workers reported finding copper sulfide in transmission electron microscope samples which had been prepared by electropolishing. It is proposed that copper sulfide can form during electrolytic dissolution because of the much greater stability of copper sulfide relative to manganese sulfide in contact with an electrolyte containing copper and manganese cations. This mechanism has been demonstrated with aluminum-killed steel samples.

  2. Calorimetric study of methyl and ethyl 2-thiophenecarboxylates and ethyl 2- and 3-thiopheneacetates

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro da Silva, Manuel A.V. [Centro de Investigacao em Quimica, Departament of Chemistry, Faculty of Science, University of Porto, Rua do Campo Alegre, 687, P-4169-007 Porto (Portugal)], E-mail: risilva@fc.up.pt; Santos, Ana Filipa L.O.M. [Centro de Investigacao em Quimica, Departament of Chemistry, Faculty of Science, University of Porto, Rua do Campo Alegre, 687, P-4169-007 Porto (Portugal)

    2009-08-15

    The standard (p{sup 0}=0.1MPa) molar enthalpies of formation, in the condensed phase, of the liquids methyl 2-thiophenecarboxylate, ethyl 2-thiophenecarboxylate, ethyl 2-thiopheneacetate, and ethyl 3-thiopheneacetate, at T = 298.15 K, were derived from the standard massic energies of combustion, in oxygen, to yield CO{sub 2} (g) and H{sub 2}SO{sub 4} . 115H{sub 2}O (aq), measured by rotating bomb combustion calorimetry. For these four compounds, the standard molar enthalpies of vaporization, {delta}{sub l}{sup g}H{sub m}{sup 0}, at T = 298.15 K, were obtained by high temperature Calvet microcalorimetry. The standard (p{sup 0}=0.1MPa) molar enthalpies of formation, in the gaseous phase, were derived from the experimental results and they are interpreted in terms of enthalpic increments of the introduction of a methylene group to the substituent chain. Moreover, the results are compared with the analogue benzene derivative.

  3. High temperature sulfide corrosion and transport properties of transition metal sulfides

    International Nuclear Information System (INIS)

    An overview is presented of the role of the defect and transport properties of transition metal sulfides on the kinetics and mechanism of high-temperature sulfide corrosion of metals and alloys. It has been shown that due to the very high concentration of defects in common metal sulfides, not only pure metals but also conventional high-temperature alloys (chromia and alumina formers) undergo very rapid degradation in highly sulfidizing environments. Refractory metals (Mo, Nb), on the other hands, are highly resistant to sulfide corrosion, their sulfidation rates being comparable with the oxidation rate of chromium. Also, alloying of common metals by niobium and molybdenum improve considerably corrosion resistance with respect to highly sulfidizing atmospheres. It has demonstrated that Al.-Mo and Al.-Mo-Si alloys shown excellent resistant to sulfidizing environments, these materials being also simultaneously oxidation resistant. Thus, new prospects have been created for the development of a new generation of coating materials, resistant to multicomponent sulfidizing-oxidizing atmospheres, often encountered in many branches of modern technology. (author)

  4. Inorganic sorbents for concentration of hydrogen sulfide

    International Nuclear Information System (INIS)

    Present work is devoted to application of inorganic sorbents for concentration of hydrogen sulfide. The elaboration of method is conducted under controlled concentrations of hydrogen sulphide from 1.00 til 0.01 mg/l.

  5. Managing hydrogen sulfide the natural way

    Energy Technology Data Exchange (ETDEWEB)

    Beasley, T.; Abry, R.G.F. [New Paradigm Gas Processing Ltd., Calgary, AB (Canada)

    2003-07-01

    This paper explores the benefits and costs associated with acid gas injection versus flaring and venting. It provides an update of Shell Paques biological gas desulfurization technology and the world's first high pressure application of the technology at the EnCana Bantry Project. The process is particularly well suited to treat sour (acid) natural gases that are currently being flared. It can also be used as an alternative to acid gas injection. Complete removal of hydrogen sulfide can be achieved by selective biotechnological conversion of hydrogen sulfide to elemental sulfur. Compared to conventional processes, this breakthrough technology achieves greater savings in terms of capital and operational costs. The Shell-Paque process produces up to 50 tonnes of sulfur per day with virtually complete conversion of hydrogen sulfide to elemental sulfur, resulting in no hydrogen sulfide based airborne emissions. 2 refs., 2 tabs., 35 figs.

  6. The Search for Interstellar Sulfide Grains

    Science.gov (United States)

    Keller, Lindsay P.; Messenger, Scott

    2010-01-01

    The lifecycle of sulfur in the galaxy is poorly understood. Fe-sulfide grains are abundant in early solar system materials (e.g. meteorites and comets) and S is highly depleted from the gas phase in cold, dense molecular cloud environments. In stark contrast, sulfur is essentially undepleted from the gas phase in the diffuse interstellar medium, indicating that little sulfur is incorporated into solid grains in this environment. It is widely believed that sulfur is not a component of interstellar dust grains. This is a rather puzzling observation unless Fe-sulfides are not produced in significant quantities in stellar outflows, or their lifetime in the ISM is very short due to rapid destruction. Fe sulfide grains are ubiquitous in cometary samples where they are the dominant host of sulfur. The Fe-sulfides (primarily pyrrhotite; Fe(1-x)S) are common, both as discrete 0.5-10 micron-sized grains and as fine (5-10 nm) nanophase inclusions within amorphous silicate grains. Cometary dust particles contain high abundances of well-preserved presolar silicates and organic matter and we have suggested that they should contain presolar sulfides as well. This hypothesis is supported by the observation of abundant Fe-sulfides grains in dust around pre- and post-main sequence stars inferred from astronomical spectra showing a broad 23 micron IR feature due to FeS. Fe-sulfide grains also occur as inclusions in bona fide circumstellar amorphous silicate grains and as inclusions within deuterium-rich organic matter in cometary dust samples. Our irradiation experiments show that FeS is far more resistant to radiation damage than silicates. Consequently, we expect that Fe sulfide stardust should be as abundant as silicate stardust in solar system materials.

  7. Mechanism of mechanical activation for sulfide ores

    Institute of Scientific and Technical Information of China (English)

    HU Hui-ping; CHEN Qi-yuan; YIN Zhou-lan; HE Yue-hui; HUANG Bai-yun

    2007-01-01

    Structural changes for mechanically activated pyrite, sphalerite, galena and molybdenite with or without the exposure to ambient air, were systematically investigated using X-ray diffraction analysis(XRD), particle size analysis, gravimetrical method, X-ray photo-electron spectroscopy(XPS) and scanning electron microscopy(SEM), respectively. Based on the above structural changes for mechanically activated sulfide ores and related reports by other researchers, several qualitative rules of the mechanisms and the effects of mechanical activation for sulfide ores are obtained. For brittle sulfide ores with thermal instability, and incomplete cleavage plane or extremely incomplete cleavage plane, the mechanism of mechanical activation is that a great amount of surface reactive sites are formed during their mechanical activation. The effects of mechanical activation are apparent. For brittle sulfide ores with thermal instability, and complete cleavage plane, the mechanism of mechanical activation is that a great amount of surface reactive sites are formed, and lattice deformation happens during their mechanical activation. The effects of mechanical activation are apparent. For brittle sulfide ores with excellent thermal stability, and complete cleavage plane, the mechanism of mechanical activation is that lattice deformation happens during their mechanical activation. The effects of mechanical activation are apparent. For sulfide ores with high toughness, good thermal stability and very excellent complete cleavage plane, the mechanism of mechanical activation is that lattice deformation happens during their mechanical activation, but the lattice deformation ratio is very small. The effects of mechanical activation are worst.

  8. Air-water transfer of hydrogen sulfide

    DEFF Research Database (Denmark)

    Yongsiri, C.; Vollertsen, J.; Rasmussen, M. R.;

    2004-01-01

    The emissions process of hydrogen sulfide was studied to quantify air–water transfer of hydrogen sulfide in sewer networks. Hydrogen sulfide transfer across the air–water interface was investigated at different turbulence levels (expressed in terms of the Froude number) and pH using batch...... experiments. By means of the overall mass–transfer coefficient (KLa), the transfer coefficient of hydrogen sulfide (KLaH2S), referring to total sulfide, was correlated to that of oxygen (KLaO2) (i.e., the reaeration coefficient). Results demonstrate that both turbulence and pH in the water phase play...... a significant role for KLaH2S. An exponential expression is a suitable representation for the relationship between KLaH2S and the Froude number at all pH values studied (4.5 to 8.0). Because of the dissociation of hydrogen sulfide, KLaH2S increased with decreasing pH at a constant turbulence level. Relative...

  9. Ethylated Urea - Ether - Modified Urea - Formaldehyde Resins,

    Directory of Open Access Journals (Sweden)

    Mathew Obichukwu EDOGA

    2006-07-01

    Full Text Available First, phenol - formaldehyde (PF and urea - formaldehyde (UFII resins were separately conventionally prepared in our laboratory. Also, UF resin synthesized from the acid modified synthesis procedure was synthesized in a purely acid medium of pH 1.0, FU molar ratio of 1.0 and at 50oC (one-stage acid modified-synthesis procedure. Subsequently, the UF resin II was modified during synthesis by incorporating ethylated urea-ether (EUER (i.e. UFIII and glycerol (GLYC (i.e. UFV cured with and without acid curing agent. The structural and physicochemical analyses of the various resin samples were carried out.The results showed that the unmodified UF resin (UF II synthesized in acid medium of pH 1.0, F/U molar ratio 1.0, and at 50oC, cured in absence of acid curing catalyst, showed features in their spectra which are consistent with a tri-, and/or tetra-substituted urea in the reaction to give a 3 - dimensional network cured UF resin. Modification of the UF resin(UF II with ethylated urea-ether and glycerol to produce UF resins III and respectively V prominently increased the absorbance of methylene and ether groups in the spectra which are consistent with increased hydrophobicity and improved hydrolytic stability. For the conventional UF resin (UF I, the only clear distinction between spectra for the UF resin II and UF resins (III/V is the presence of diminished peaks for methylene groups at 2.2 ppm. The relationship between the logarithmic viscosity of cured PF resin with time showed continuos dependence of viscosity with time during cure up to 70 minutes. Similar trends were shown by UF resins (III/V, cured in absence of acid catalyst. In contrast, the conventional UF resins I and UF IV (i.e. UF II cured with NH4CL showed abrupt discontinuity in viscosity with time just after about 20 minutes of cure.

  10. Characterization of environmental samples using ion trap-secondary ion mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Groenewold, G.S.; Appelhans, A.D.; Ingram, J.C.

    1998-02-01

    The detection of chemical warfare agent residues on environmental surfaces is an important analytical activity because of the potential for proliferation of these weapons, and for environmental monitoring in areas where they are stored. Historically, one of the most widely used agents has been bis(2-chloroethyl) sulfide, also known as mustard gas and HD. It was initially used in combat in 1917; by the end of the First World War, more than 16% of all casualties were due to chemicals, in most cases mustard. Manufacture of mustard is continuing to this day; consequently, there are ongoing opportunities for exposure. 2-Chloroethyl ethyl sulfide (CEES) is used as a simulant for mustard (HD) in a study to develop secondary ion mass spectrometry (SIMS) for rapid, semi-quantitative detection of mustard on soil. Using SIMS with single stage mass spectrometry, a signature for CEES can be unequivocally observed only at the highest concentrations (0.1 monolayer and above). Selectivity and sensitivity are markedly improved employing multiple-stage mass spectrometry using an ion trap. C{sub 2}H{sub 5}SC{sub 2}H{sub 4}{sup +} from CEES eliminates C{sub 2}H{sub 4} and H{sub 2}S, which are highly diagnostic. CEES was detected at 0.0012 monolayer on soil. A single analysis could be conducted in under 5 minutes.

  11. A Choline Oxidase Amperometric Bioassay for the Detection of Mustard Agents Based on Screen-Printed Electrodes Modified with Prussian Blue Nanoparticles

    Directory of Open Access Journals (Sweden)

    Fabiana Arduini

    2015-02-01

    Full Text Available In this work a novel bioassay for mustard agent detection was proposed. The bioassay is based on the capability of these compounds to inhibit the enzyme choline oxidase. The enzymatic activity, which is correlated to the mustard agents, was electrochemically monitored measuring the enzymatic product, hydrogen peroxide, by means of a screen-printed electrode modified with Prussian Blue nanoparticles. Prussian Blue nanoparticles are able to electrocatalyse the hydrogen peroxide concentration reduction at low applied potential (−50 mV vs. Ag/AgCl, thus allowing the detection of the mustard agents with no electrochemical interferences. The suitability of this novel bioassay was tested with the nitrogen mustard simulant bis(2-chloroethylamine and the sulfur mustard simulants 2-chloroethyl ethyl sulfide and 2-chloroethyl phenyl sulfide. The bioassay proposed in this work allowed the detection of mustard agent simulants with good sensitivity and fast response, which are excellent premises for the development of a miniaturised sensor well suited for an alarm system in case of terrorist attacks.

  12. Hydrogen sulfide can inhibit and enhance oxygenic photosynthesis in a cyanobacterium from sulfidic springs

    NARCIS (Netherlands)

    Klatt, Judith M.; Haas, Sebastian; Yilmaz, Pelin; de Beer, Dirk; Polerecky, Lubos

    2015-01-01

    We used microsensors to investigate the combinatory effect of hydrogen sulfide (H2S) and light on oxygenic photosynthesis in biofilms formed by a cyanobacterium from sulfidic springs. We found that photosynthesis was both positively and negatively affected by H2S: (i) H2S accelerated the recovery of

  13. Sulfide response analysis for sulfide control using a pS electrode in sulfate reducing bioreactors

    NARCIS (Netherlands)

    Villa Gomez, D.K.; Cassidy, J.; Keesman, K.J.; Sampaio, R.M.; Lens, P.N.L.

    2014-01-01

    Step changes in the organic loading rate (OLR) through variations in the influent chemical oxygen demand (CODin) concentration or in the hydraulic retention time (HRT) at constant COD/SO4 2- ratio (0.67) were applied to create sulfide responses for the design of a sulfide control in sulfate reducing

  14. On the cause of low thermal stability of ethyl halodiazoacetates

    Science.gov (United States)

    Mortén, Magnus; Hennum, Martin

    2016-01-01

    Summary Rates for the thermal decomposition of ethyl halodiazoacetates (halo = Cl, Br, I) have been obtained, and reported herein are their half-lives. The experimental results are supported by DFT calculations, and we provide a possible explanation for the reduced thermal stability of ethyl halodiazoacetates compared to ethyl diazoacetate and for the relative decomposition rates between the chloro, bromo and iodo analogs. We have also briefly studied the thermal, non-catalytic cyclopropanation of styrenes and compared the results to the analogous Rh(II)-catalyzed reactions. PMID:27559411

  15. Ethyl ester production from (RBD palm oil

    Directory of Open Access Journals (Sweden)

    Oscar Mauricio Martínez Ávila

    2010-07-01

    Full Text Available This work develops a methodology for obtaining ethyl esters from RBD (refined, bleached and deodorised palm oil by evaluating the oil’s transesterification and separation. Two catalysts were first tested (KOH and NaOH by studying the effect of water presence on the reaction. The separation process was then evaluated by using water and water-salt and water-acid mixtures, establishing the agent offering the best results and carrying out the purification stage. Raw materials and products were characterised for comparing the latter with those obtained by traditional means and verifying the quality of the esters so produced; minimum differences were found bet-ween both. The proposed methodology thus allows esters to be used as raw material in petrochemical industry applications. A more profitable process can be obtained compared to those used today, given the amounts of separation agent so established (1% H3PO4 solution, in water. The overall process achieved 74.4% yield, based on the oil being used.

  16. Stratospheric carbonyl sulfide (OCS) burden

    Science.gov (United States)

    Kloss, Corinna; Walker, Kaley A.; Deshler, Terry; von Hobe, Marc

    2015-04-01

    An estimation of the global stratospheric burden of carbonyl sulfide (OCS) calculated using satellite based measurements from the Atmospheric Chemistry Experiment - Fourier Transform Spectrometer (ACE-FTS) will be presented. OCS is the most abundant sulfur containing gas in the atmosphere in the absence of volcanic eruptions. With a long lifetime of 2-6 years it reaches the stratosphere where it is photolyzed and the sulfur oxidized and condensed to aerosols, contributing to the stratospheric aerosol layer. The aerosol layer is the one factor of the middle-atmosphere with a direct impact on the Earth's climate by scattering incoming solar radiation back to space. Therefore it is crucial to understand and estimate the different processes and abundances of the species contributing to the aerosol layer. However, the exact amount of OCS in the stratosphere has not been quantified yet. A study on the OCS mixing ratio distribution based on ACE-FTS data has already been made by Barkley et al. (2008), also giving an estimation for the total atmospheric OCS mass. ACE-FTS is an infrared solar occultation spectrometer providing high- resolution profile observations since 2004. In the scope of this work the focus lies on the stratospheric OCS burden, calculated by integrating the ACE profiles. A global overview on the stratospheric OCS amount in the past and present based on the ACE data as well as a look at regional and seasonal variability will be given. Furthermore, the results of this work will be useful for further studies on OCS fluxes and lifetimes, and in quantifying the contribution of OCS to the global stratospheric sulfur burden. Barkley et al., 2008, Geophys. Res. Lett., 35, L14810.

  17. Terahertz spectroscopy of hydrogen sulfide

    International Nuclear Information System (INIS)

    Pure rotational transitions of hydrogen sulfide (H2S) in its ground and first excited vibrational states have been recorded at room temperature. The spectrum comprises an average of 1020 scans at 0.005 cm−1 resolution recorded in the region 45–360 cm−1 (1.4 to 10.5 THz) with a globar continuum source using a Fourier transform spectrometer located at the AILES beamline of the SOLEIL synchrotron. Over 2400 rotational lines have been detected belonging to ground vibrational state transitions of the four isotopologues H232S, H233S, H234S, and H236S observed in natural abundance. 65% of these lines are recorded and assigned for the first time, sampling levels as high as J=26 and Ka=17 for H232S. 320 pure rotational transitions of H232S in its first excited bending vibrational state are recorded and analysed for the first time and 86 transitions for H234S, where some of these transitions belong to new experimental energy levels. Rotational constants have been fitted for all the isotopologues in both vibrational states using a standard effective Hamiltonian approach. Comprehensive comparisons are made with previously available data as well as the data available in HITRAN, CDMS, and JPL databases. The 91 transitions assigned to H236S give the first proper characterization of its pure rotational spectrum. -- Highlights: • Over 2400 lines are measured and assigned in the 45–360 cm−1 region. • New rotational transitions are assigned for four isotopologues of H2S. • Rotational transitions within the first excited state of H2S are assigned for the first time. • An improved rotational line list is presented

  18. [Reaction of 1,8-naphthyridine azides with ethyl acrylate].

    Science.gov (United States)

    Livi, O; Ferrarini, P L; Bertini, D; Tonetti, I

    1975-12-01

    The reaction of 1,8-naphthyridine azides with ethyl acrylate leads to the formation of 2-pyrazolines instead of 1,2,3-triazolines. Some of the compounds obtained have undergone pharmacological and microbiological (antibacterial) testing. PMID:1204828

  19. Binding Affinity of Novel Cyclodextrin Dimers to Ethyl Orange

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The interaction between ethyl orange (Eto, guest) and β-cyclodextrin dimers (1a~d, host) bridged with 2-t-butoxycarbonyl(Boc)-amino diacid was investigated. A remarkable synergic complexation of two cavities in host molecule was observed.

  20. Sulfide capacities of fayalite-base slags

    Science.gov (United States)

    Simeonov, S. R.; Sridhar, R.; Toguri, J. M.

    1995-04-01

    The sulfide capacities of fayalite-base slags were measured by a gas-slag equilibration technique under controlled oxygen and sulfur potentials similar to those encountered in the pyrometallurgical processing of nonferrous metals. The oxygen pressure range was from 10-9.5 to 10-11 MPa and the sulfur pressure range from 10-3 to 10-4.5 MPa, over a temperature range of 1473 to 1623 K. The slags studied were FeO-SiO2 at silica saturation and those with addition of CaO, MgO, and Al2O3 to determine their effect on sulfide capacities. For these slags, the sulfide capacities were found to vary from 10-3.3 to 10-5. The sulfide capacities increased with increasing temperature from 1473 to 1623 K. A comparison of the reported plant data on sulfur content of industrial slags shows good agreement with the present experimental results. The present data will be useful in estimating metal losses in slag due to metal sulfide entrainment in nonferrous smelters.

  1. Synthesis of magnetic rhenium sulfide composite nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Tang Naimei [Division of Molecular and Materials Simulation, Key Lab for Nanomaterials, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China); Tu Weixia [Division of Molecular and Materials Simulation, Key Lab for Nanomaterials, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China)], E-mail: tuwx@mail.buct.edu.cn

    2009-10-15

    Rhenium sulfide nanoparticles are associated with magnetic iron oxide through coprecipitation of iron salts with tetramethylammonium hydroxide. Sizes of the formed magnetic rhenium sulfide composite particles are in the range 5.5-12.5 nm. X-ray diffraction and energy-dispersive analysis of X-rays spectra demonstrate the coexistence of Fe{sub 3}O{sub 4} and ReS{sub 2} in the composite particle, which confirm the formation of the magnetic rhenium sulfide composite nanoparticles. The association of rhenium sulfide with iron oxide not only keeps electronic state and composition of the rhenium sulfide nanoparticles, but also introduces magnetism with the level of 24.1 emu g{sup -1} at 14 kOe. Surface modification with monocarboxyl-terminated poly(ethylene glycol) (MPEG-COOH) has the role of deaggregating the composite nanoparticles to be with average hydrodynamic size of 27.3 nm and improving the dispersion and the stability of the composite nanoparticles in water.

  2. Multidimensional chromatographic approach applied to the identification of novel aroma compounds in wine. Identification of ethyl cyclohexanoate, ethyl 2-hydroxy-3-methylbutyrate and ethyl 2-hydroxy-4-methylpentanoate.

    Science.gov (United States)

    Campo, E; Cacho, J; Ferreira, V

    2006-12-29

    A multidimensional chromatographic strategy has been developed and optimized with the purpose of identifying different odorants potentially relevant to the aroma and flavor of aged wines from Madeira or Sherry. Different techniques of extraction and fractionation were studied in order to get clear olfactometric and spectrometric signals from the target odorants. The best results were obtained with a dynamic headspace extraction followed by a fractionation on a normal phase medium pressure liquid chromatography on a silicagel column. Large volumes (50 microl) of the concentrated fractions were further analyzed in a dual gas chromatography-mass spectrometric system (GC-MS) equipped with two olfactometric ports. The strategy made it possible to identify in wine by first time the presence of the powerful strawberry-smelling compound, ethyl cyclohexanoate, and of two other novel fruity esters, ethyl 2-hydroxy-3-methylbutyrate and ethyl 2-hydroxy-4-methylpentanoate. Some other unidentified odorants could be isolated and their mass spectra are given. PMID:17069823

  3. Process intensification for the ethyl lactate synthesis : integrated pervaporation reactor

    OpenAIRE

    Pereira, C.S.M.; Silva, V.M.T.M.; Pinho, Simão; A. E. Rodrigues

    2011-01-01

    Ethyl lactate is an important organic ester, which is biodegradable, produced by renewable resources and can be used as food additive, perfumery, flavor chemicals, solvent and pharmaceutical preparations[1]. It is a green solvent and could replace a range of environment-damaging halogenated and toxic solvents (for example: Nmethylpyrrolidone, toluene)[2]. The conventional way to produce ethyl lactate is the esterification of lactic acid with ethanol in the presence of an acid cata...

  4. CHARACTERIZATION OF CAPTOPRIL-ETHYL CELLULOSE MICROSPHERES BY THERMAL ANALYSIS

    Directory of Open Access Journals (Sweden)

    RakeshGupta

    2010-06-01

    Full Text Available The objective of the present study was to study the physical characterization of Captopril-ethyl cellulose microspheres by thermal analysis such as Differential Scanning Calorimetry (DSC, Differential thermal analysis (DTA and Thermo gravimetry (TG. Drug polymer interaction can directly affect the dosage form stability, drug encapsulation into polymers and dissolution patterns. In this study thermal analysis has been carried out for the physical mixtures and microspheres of captopril and ethyl cellulose prepared by solvent evaporation method.

  5. A newly discovered xenobiotic metabolic pathway: Ethyl ester formation

    Energy Technology Data Exchange (ETDEWEB)

    Chou, R.C.; Wyss, R.; Huselton, C.A.; Wiegand, U.W. (F. Hoffmann-La Roche Ltd., Basel (Switzerland))

    1991-01-01

    Formation of etretinate, ethyl ester of acitretin, can be confirmed in vitro and in vivo using acitretin as the substrate. Etretinate was identified by LC/MS. The in vitro incubation was performed using rat and human liver 12000 g supernatant, and the in vivo experiment was conducted in rats after oral dosing of acitretin. The ethyl ester formation was greatly enhanced by addition of or dosing with ethanol.

  6. Ethyl coumarin-3-carboxylate: synthesis and chemical properties

    Directory of Open Access Journals (Sweden)

    Bakr F. Abdel-Wahab

    2014-03-01

    Full Text Available Ethyl coumarin-3-carboxylate occupies an important position in the organic synthesis and is used in production of biologically active compounds. Thus, the data published over the last few years on the methods of synthesis and chemical properties of ethyl coumarin-3-carboxylate are reviewed here for the first time. The reactions were classified as coumarin ring reactions and ester group reactions, and some of these reactions have been applied successfully to the synthesis of biologically and industrially important compounds.

  7. Ethyl glucuronide and ethyl sulfate in autopsy samples 27 years after death.

    Science.gov (United States)

    Politi, Lucia; Morini, Luca; Mari, Francesco; Groppi, Angelo; Bertol, Elisabetta

    2008-11-01

    The unique case of a 50-year-old known alcoholic whose corpse was exhumed 27 years after death is reported. The man apparently committed suicide by hanging, but many years later the case was questioned and homicide-linked to a long-lasting serial killer case-was suspected. Thus, the corpse was exhumed, and at the autopsy it was found to be naturally mummified. This fact permitted the analysis of body tissues with the aim to investigate the persistence of ethanol conjugates in the biological material 27 years after death. Fragments of liver and kidney, a blood clot, and a hair strand were collected and submitted to liquid chromatography tandem mass spectrometry analysis. Ethyl glucuronide (EtG) and ethyl sulfate (EtS) were identified and quantified in the liver, the kidney, and the blood clot. Hair analysis was found to be severely affected by ion suppression even after solid phase extraction. Consequently, EtG was identified in all hair segments (0-3 cm, 3-6 cm, and 6-10 cm), but no reliable quantification could be carried out. In summary, our findings demonstrate that, notwithstanding the expected conjugate degradation, EtG and EtS can be indicative of ante-mortem use of alcohol even many years after death.

  8. Transition Metal Catalyzed Synthesis of Aryl Sulfides

    Directory of Open Access Journals (Sweden)

    Chad C. Eichman

    2011-01-01

    Full Text Available The presence of aryl sulfides in biologically active compounds has resulted in the development of new methods to form carbon-sulfur bonds. The synthesis of aryl sulfides via metal catalysis has significantly increased in recent years. Historically, thiolates and sulfides have been thought to plague catalyst activity in the presence of transition metals. Indeed, strong coordination of thiolates and thioethers to transition metals can often hinder catalytic activity; however, various catalysts are able to withstand catalyst deactivation and form aryl carbon-sulfur bonds in high-yielding transformations. This review discusses the metal-catalyzed arylation of thiols and the use of disulfides as metal-thiolate precursors for the formation of C-S bonds.

  9. Sulfide and methane production in sewer sediments.

    Science.gov (United States)

    Liu, Yiwen; Ni, Bing-Jie; Ganigué, Ramon; Werner, Ursula; Sharma, Keshab R; Yuan, Zhiguo

    2015-03-01

    Recent studies have demonstrated significant sulfide and methane production by sewer biofilms, particularly in rising mains. Sewer sediments in gravity sewers are also biologically active; however, their contribution to biological transformations in sewers is poorly understood at present. In this study, sediments collected from a gravity sewer were cultivated in a laboratory reactor fed with real wastewater for more than one year to obtain intact sediments. Batch test results show significant sulfide production with an average rate of 9.20 ± 0.39 g S/m(2)·d from the sediments, which is significantly higher than the areal rate of sewer biofilms. In contrast, the average methane production rate is 1.56 ± 0.14 g CH4/m(2)·d at 20 °C, which is comparable to the areal rate of sewer biofilms. These results clearly show that the contributions of sewer sediments to sulfide and methane production cannot be ignored when evaluating sewer emissions. Microsensor and pore water measurements of sulfide, sulfate and methane in the sediments, microbial profiling along the depth of the sediments and mathematical modelling reveal that sulfide production takes place near the sediment surface due to the limited penetration of sulfate. In comparison, methane production occurs in a much deeper zone below the surface likely due to the better penetration of soluble organic carbon. Modelling results illustrate the dependency of sulfide and methane productions on the bulk sulfate and soluble organic carbon concentrations can be well described with half-order kinetics.

  10. Modeling of Sulfide Microenvironments on Mars

    Science.gov (United States)

    Schwenzer, S. P.; Bridges, J. C.; McAdam, A.; Steer, E. D.; Conrad, P. G.; Kelley, S. P.; Wiens, R. C.; Mangold, N.; Grotzinger, J.; Eigenbrode, J. L.; Franz, H. B.; Sutter, B.

    2016-01-01

    Yellowknife Bay (YKB; sol 124-198) is the second site that the Mars Science Laboratory Rover Curiosity investigated in detail on its mission in Gale Crater. YKB represents lake bed sediments from an overall neutral pH, low salinity environment, with a mineralogical composition which includes Ca-sulfates, Fe oxide/hydroxides, Fe-sulfides, amorphous material, and trioctahedral phyllosilicates. We investigate whether sulfide alteration could be associated with ancient habitable microenvironments in the Gale mudstones. Some textural evidence for such alteration may be pre-sent in the nodules present in the mudstone.

  11. Acute inhalation toxicity of carbonyl sulfide

    Energy Technology Data Exchange (ETDEWEB)

    Benson, J.M.; Hahn, F.F.; Barr, E.B. [and others

    1995-12-01

    Carbonyl sulfide (COS), a colorless gas, is a side product of industrial procedures sure as coal hydrogenation and gasification. It is structurally related to and is a metabolite of carbon disulfide. COS is metabolized in the body by carbonic anhydrase to hydrogen sulfide (H{sub 2}S), which is thought to be responsible for COS toxicity. No threshold limit value for COS has been established. Results of these studies indicate COS (with an LC{sub 50} of 590 ppm) is slightly less acutely toxic than H{sub 2}S (LC{sub 50} of 440 ppm).

  12. Sol-gel processing of metal sulfides

    Science.gov (United States)

    Stanic, Vesha

    Metal sulfides were synthesised via a sol-gel process using various metal alkoxides and hydrogen sulfide in toluene. Colloidal gels were prepared from germanium ethoxide, germanium isopropoxide, zinc tert-butoxide and tungsten (VI) ethoxide, whereas colloidal powder was produced from tungsten (V) dichloride ethoxide. Special precautions were necessary to protect the reaction mixture from water contamination which produced metal oxides. Results indicated that the main source of water is the hydrogen sulfide gas. In addition, synthesis of metal sulfides from a mixture of metal oxide and sulfide was demonstrated by the example of monoclinic germanium disulfide. It was produced by reaction of the sol-gel product with sulfur. Heat treatment of the sol-gel product and sulfur yielded single phase GeSsb2. The sol-gel prepared materials and their heat treated products were characterized by various methods. A chemical kinetics study of the functional groups -OR, -SH and Ssp{2-} was carried out for the sol-gel processing of GeSsb2 from of hydrogen sulfide and two different alkoxides, germanium ethoxide and germanium isopropoxide. The study was performed for different concentrations of precursors at different molar ratios and temperatures. The results indicate that the proposed reaction mechanism was simplified under appropriate reaction conditions. Experimentally determined rate constants of thiolysis and condensations demonstrate that thiolysis is slow and that condensations are fast steps, regardless of the studied reaction conditions. A study of the temperature effect on the reaction rate constant shows that it increases with temperature in accord with both Arrhenius law and transition-state theory. Activation energies, Esba, and activation parameters DeltaSsp{ddagger}, DeltaHsp{ddagger} and DeltaGsp{ddagger}, were determined for thiolysis and condensation reactions. The potentiometric tiration method was used for quantitative determination of germanium sulfide and

  13. Membrane for hydrogen recovery from streams containing hydrogen sulfide

    Science.gov (United States)

    Agarwal, Pradeep K.

    2007-01-16

    A membrane for hydrogen recovery from streams containing hydrogen sulfide is provided. The membrane comprises a substrate, a hydrogen permeable first membrane layer deposited on the substrate, and a second membrane layer deposited on the first layer. The second layer contains sulfides of transition metals and positioned on the on a feed side of the hydrogen sulfide stream. The present invention also includes a method for the direct decomposition of hydrogen sulfide to hydrogen and sulfur.

  14. Bile-acid-activated farnesoid X receptor regulates hydrogen sulfide production and hepatic microcirculation

    Institute of Scientific and Technical Information of China (English)

    Barbara Renga; Andrea Mencarelli; Marco Migliorati; Eleonora Distrutti; Stefano Fiorucci

    2009-01-01

    AIM: To investigate whether the farnesoid X receptor (FXR) regulates expression of liver cystathionase (CSE), a gene involved in hydrogen sulfide (H2S) generation. METHODS: The regulation of CSE expression in response to FXR ligands was evaluated in HepG2 cells and in wild-type and FXR null mice treated with 6-ethyl chenodeoxycholic acid (6E-CDCA), a synthetic FXR ligand. The analysis demonstrated an FXR responsive element in the 5'-flanking region of the human CSE gene. The function of this site was investigated by luciferase reporter assays, chromatin immunoprecipitation and electrophoretic mobility shift assays. Livers obtained from rats treated with carbon tetrachloride alone, or in combination with 6-ethyl chenodeoxycholic acid, were studied for hydrogen sulphide generation and portal pressure measurement. RESULTS: Liver expression of CSE is regulated by bile acids by means of an FXR-mediated mechanism. Western blotting, qualitative and quantitative polymerase chain reaction, as well as immunohistochemical analysis, showed that expression of CSE in HepG2 cells and in mice is induced by treatment with an FXR ligand. Administration of 6E-CDCA to carbon tetrachloride treated rats protected against the down-regulation of CSE expression, increased H2S generation, reduced portal pressure and attenuated the endothelial dysfunction of isolated and perfused cirrhotic rat livers. CONCLUSION: These results demonstrate that CSE is an FXR-regulated gene and provide a new molecular explanation for the pathophysiology of portal hypertension.

  15. Use of biogenic sulfide for ZnS precipitation

    NARCIS (Netherlands)

    Esposito, G.; Veeken, A.; Weijma, J.; Lens, P.N.L.

    2006-01-01

    A 600 ml continuously stirred tank reactor was used to assess the performance of a zinc sulfide precipitation process using a biogenic sulfide solution (the effluent of a sulfate-reducing bioreactor) as sulfide source. In all experiments, a proportional-integral (PI) control algorithm was used to co

  16. A physiologically based kinetic model for bacterial sulfide oxidation

    NARCIS (Netherlands)

    Klok, J.B.; Graaff, M. de; Bosch, P.L. van den; Boelee, N.C.; Keesman, K.J.; Janssen, A.J.W.M.

    2013-01-01

    In the biotechnological process for hydrogen sulfide removal from gas streams, a variety of oxidation products can be formed. Under natron-alkaline conditions, sulfide is oxidized by haloalkaliphilic sulfide oxidizing bacteria via flavocytochrome c oxidoreductase. From previous studies, it was concl

  17. T.O.C.S. : Hydrogen Sulfide Remission System

    OpenAIRE

    ECT Team, Purdue

    2007-01-01

    BioEnviroTech, Inc., (BET) developed Toxicity Odor Corrosion Sulfides (T.O.C.S.) Remission System for hydrogen sulfide reduction in municipal and industrial wastewater sewer, lift stations and force mains. This safe and cost effective biotreatment technology uses safe and natural bacteria to interrupt sulfide generation.

  18. Continuous production of palm biofuel under supercritical ethyl acetate

    International Nuclear Information System (INIS)

    Highlights: • Continuous synthesized biofuel from palm oil in supercritical ethyl acetate was examined. • Mass flow rate of palm oil and ethyl acetate mixture influent to biofuel production in continuous system. • Water addition to reacting mixture improves the production of fatty acid ethyl esters and triacetin. • The generated acetic acid from ETA hydrolysis can protect the products from thermal decomposition. - Abstract: The interesterification of palm oil in supercritical ethyl acetate (ETA) to produce fatty acid ethyl ester (FAEEs) or biofuel was conducted in a continuous tubular reactor. The density of the mixtures in the system was estimated using the Peng–Robinson equation of state process simulator, and the residence time was calculated. The effects of the reaction conditions, including the molar ratios of palm oil to ethyl acetate, the temperature, and the pressure, were investigated under various mass flow rates of the mixtures and optimized. The results showed that reaction temperatures above 653 K and long residence times affected the content of FAEEs and triacetin, a valuable by-product. The addition of water to the mixture in a 1:30:10 M ratio of palm oil to ethyl acetate to water at 653 K, 16 MPa, and a mixture mass flow rate of 1.5 g/min increased the total production of FAEEs and triacetin from 90.9 to 101.5 wt% in 42.4 min. The main finding of the present study is that triglyceride associated with ETA hydrolysis used to form acetic acid protected the products from decomposition at high temperatures and long residence times. The results will aid the selection of an efficient and economical process for alternative biofuel production from palm oil in supercritical ETA

  19. Measurement and biological significance of the volatile sulfur compounds hydrogen sulfide, methanethiol and dimethyl sulfide in various biological matrices

    NARCIS (Netherlands)

    Tangerman, Albert

    2009-01-01

    This review deals with the measurement of the volatile Sulfur compounds hydrogen sulfide, methanethiol and dimethyl sulfide in various biological matrices of rats and humans (blood, serum, tissues, urine, breath, feces and flatus). Hydrogen sulfide and methanethiol both contain the active thiol (-SH

  20. Measurement and biological significance of the volatile sulfur compounds hydrogen sulfide, methanethiol and dimethyl sulfide in various biological matrices.

    NARCIS (Netherlands)

    Tangerman, A.

    2009-01-01

    This review deals with the measurement of the volatile sulfur compounds hydrogen sulfide, methanethiol and dimethyl sulfide in various biological matrices of rats and humans (blood, serum, tissues, urine, breath, feces and flatus). Hydrogen sulfide and methanethiol both contain the active thiol (-SH

  1. Hydrogen Sulfide in Preeclampsia : Potential Therapeutic Implications

    NARCIS (Netherlands)

    Holwerda, Kim

    2015-01-01

    The thesis provide insights into the production and possible therapeutic effect of the gaseous molecule hydrogen sulfide (H2S) in preeclampsia (PE). H2S is an important molecule in the (human) body. It is among others involved in blood pressure regulation, stimulation of vascular growth and modulati

  2. Monitoring sulfide and sulfate-reducing bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Tanner, R.S.

    1995-12-31

    Simple yet precise and accurate methods for monitoring sulfate-reducing bacteria (SRB) and sulfide remain useful for the study of bacterial souring and corrosion. Test kits are available to measure sulfide in field samples. A more precise methylene blue sulfide assay for both field and laboratory studies is described here. Improved media, compared to that in API RP-38, for enumeration of SRB have been formulated. One of these, API-RST, contained cysteine (1.1 mM) as a reducing agent, which may be a confounding source of sulfide. While cysteine was required for rapid enumeration of SRB from environmental samples, the concentration of cysteine in medium could be reduced to 0.4 mM. It was also determined that elevated levels of yeast extract (>1 g/liter) could interfere with enumeration of SRB from environmental samples. The API-RST medium was modified to a RST-11 medium. Other changes in medium composition, in addition to reduction of cysteine, included reduction of the concentration of phosphate from 3.4 mM to 2.2 mM, reduction of the concentration of ferrous iron from 0.8 mM to 0.5 mM and preparation of a stock mineral solution to ease medium preparation. SRB from environmental samples could be enumerated in a week in this medium.

  3. The diagenesis of carbohydrates by hydrogen sulfide

    Science.gov (United States)

    Mango, Frank D.

    1983-08-01

    Carbohydrates react with hydrogen sulfide under low temperature (100° to 200°C) yielding a variety of organosulfur compounds including thiophenes, thiols, sulfides and sulfones. A polymer is also produced, whose elemental composition is within the range of natural coals. When reductive dehydration is carried out in the presence of hydrocarbon, organosulfur compounds are formed in the carbon number range of the hydrocarbon used. In these processes, an active hydrogen transfer catalyst is produced which facilitates the passage of hydrogen between normal paraffins and saccharide units, distributing sulfur between these two families primarily in the form of thiophene rings. The simplicity of these systems - H 2S, carbohydrates, H 2O, hydrocarbon - and the facility of the chemistry would suggest that the carbohydrates and hydrogen sulfide may be important agents in the diagenetic processes leading to petroleum and coal. Carbohydrate reduction by hydrogen sulfide may constitute an important route through which certain organosulfur compounds found in petroleum and coal entered these materials in early diagenesis.

  4. Density, viscosity, and saturated vapor pressure of ethyl trifluoroacetate

    International Nuclear Information System (INIS)

    Highlights: • Density of ethyl trifluoroacetate was measured and its thermal expansion coefficient was determined. • Viscosity of ethyl trifluoroacetate was measured and fitted to the Andrade equation. • Saturated vapor pressure of ethyl trifluoroacetate was reported. • The Clausius–Clapeyron equation was used to calculate the molar evaporation enthalpy of ethyl trifluoroacetate. - Abstract: The properties of ethyl trifluoroacetate (CF3COOCH2CH3) were measured as a function of temperature: density (278.08 to 322.50) K, viscosity (293.45 to 334.32) K, saturated vapor pressure (293.35 to 335.65) K. The density data were fitted to a quadratic polynomial equation, and the viscosity data were regressed to the Andrade equation. The correlation coefficient (R2) of equations for density and viscosity are 0.9997 and 0.9999, respectively. The correlation between saturated vapor pressures and temperatures was achieved with a maximum absolute relative deviation of 0.142%. In addition, the molar evaporation enthalpy in the range of T = (293.35 to 335.65) K was estimated by the Clausius–Clapeyron equation

  5. Recent findings on sinks for sulfide in gravity sewer networks

    DEFF Research Database (Denmark)

    Nielsen, Asbjørn Haaning; Hvitved-Jacobsen, Thorkild; Vollertsen, Jes

    2006-01-01

    Sulfide buildup in sewer networks is associated with several problems, including health impacts, corrosion of sewer structures and odor nuisance. In recent years, significant advances in the knowledge of the major processes governing sulfide buildup in sewer networks have been made. This paper...... summarizes this newly obtained knowledge and emphasizes important implications of the findings. Model simulations of the in-sewer processes important for the sulfur cycle showed that sulfide oxidation in the wetted biofilm is typically the most important sink for dissolved sulfide in gravity sewers. However......, sulfide emission and thereby potential hydrogen sulfide buildup in the sewer atmosphere is of particular importance in sewers constructed with large diameter pipes, in sewers constructed with steep slopes and in sewers conveying low pH wastewater. Precipitation of metal sulfides is only important when...

  6. Unimolecular Gas-Phase Thermolysis of Ethyl Acetate

    DEFF Research Database (Denmark)

    Egsgaard, Helge; Carlsen, Lars

    1983-01-01

    The unimolecular gas-phase thermolysis of ethyl acetate has been investigated by the Flash-Vacuum-Thermolysis/Field-Ionization Mass Spectrometry (FVT/FI-MS) method in combination with Collision Activation (CA) mass spectrometry at 1253K. Two predominant reactions are observed: elimination...... of ethylene affording acetic acid, the latter to some extent consecutively yielding ketene, and intramolecular oxygen to oxygen ethyl group migration. Additionally minor amounts of acetaldehyde is formed. The mechanistic aspects are discussed based on 18O and 18O/ 13C labelling....

  7. Assistance of ethyl glucuronide and ethyl sulfate in the interpretation of postmortem ethanol findings.

    Science.gov (United States)

    Krabseth, Hege; Mørland, Jørg; Høiseth, Gudrun

    2014-09-01

    Postmortem ethanol formation is a well-known problem in forensic toxicology. The aim of this study was to interpret findings of ethanol in blood, in a large collection of forensic autopsy cases, by use of the nonoxidative ethanol metabolites, ethyl glucuronide (EtG), and ethyl sulfate (EtS). In this study, according to previously published literature, antemortem ethanol ingestion was excluded in EtS-negative cases. Among 493 ethanol-positive forensic autopsy cases, collected during the study period, EtS was not detected in 60 (12 %) of the cases. Among cases with a blood alcohol concentration (BAC) of ≤ 0.54 g/kg, antemortem ethanol ingestion was excluded in 38 % of the cases, while among cases with a BAC of ≥ 0.55 g/kg, antemortem ethanol ingestion was excluded in 2.2 % of the cases. For all cases where ethanol was measured at a concentration >1.0 g/kg, EtS was detected. The highest blood ethanol concentration in which EtS was not detected was 1.0 g/kg. The median concentrations of EtG and EtS in blood were 9.5 μmol/L (range: not detected (n.d.) 618.1) and 9.2 μmol/L (range: n.d. 182.5), respectively. There was a statistically significant positive correlation between concentration levels of ethanol and of EtG (Spearman's rho=0.671, p<0.001) and EtS (Spearman's rho=0.670, p<0.001), respectively. In conclusion, this study showed that in a large number of ethanol-positive forensic autopsy cases, ethanol was not ingested before the time of death, particularly among cases where ethanol was present in lower blood concentrations. Routine measurement of EtG and EtS should therefore be recommended, especially in cases with BAC below 1 g/kg. PMID:24935750

  8. Sulfide Intrusion and Detoxification in the Seagrass Zostera marina.

    Directory of Open Access Journals (Sweden)

    Harald Hasler-Sheetal

    Full Text Available Gaseous sulfide intrusion into seagrasses growing in sulfidic sediments causes little or no harm to the plant, indicating the presence of an unknown sulfide tolerance or detoxification mechanism. We assessed such mechanism in the seagrass Zostera marina in the laboratory and in the field with scanning electron microscopy coupled to energy dispersive X-ray spectroscopy, chromatographic and spectrophotometric methods, and stable isotope tracing coupled with a mass balance of sulfur compounds. We found that Z. marina detoxified gaseous sediment-derived sulfide through incorporation and that most of the detoxification occurred in underground tissues, where sulfide intrusion was greatest. Elemental sulfur was a major detoxification compound, precipitating on the inner wall of the aerenchyma of underground tissues. Sulfide was metabolized into thiols and entered the plant sulfur metabolism as well as being stored as sulfate throughout the plant. We conclude that avoidance of sulfide exposure by reoxidation of sulfide in the rhizosphere or aerenchyma and tolerance of sulfide intrusion by incorporation of sulfur in the plant are likely major survival strategies of seagrasses in sulfidic sediments.

  9. The Evolution of Sulfide Tolerance in the Cyanobacteria

    Science.gov (United States)

    Miller, Scott R.; Bebout, Brad M.; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    Understanding how the function of extant microorganisms has recorded both their evolutionary histories and their past interactions with the environment is a stated goal of astrobiology. We are taking a multidisciplinary approach to investigate the diversification of sulfide tolerance mechanisms in the cyanobacteria, which vary both in their degree of exposure to sulfide and in their capacity to tolerate this inhibitor of photosynthetic electron transport. Since conditions were very reducing during the first part of Earth's history and detrital sulfides have been found in Archean sediments, mechanisms conferring sulfide tolerance may have been important for the evolutionary success of the ancestors of extant cyanobacteria. Two tolerance mechanisms have been identified in this group: (1) resistance of photosystem II, the principal target of sulfide toxicity; and (2) maintenance of the ability to fix carbon despite photosystem II inhibition by utilizing sulfide as an electron donor in photosystem I - dependent, anoxygenic photosynthesis. We are presently collecting comparative data on aspects of sulfide physiology for laboratory clones isolated from a variety of habitats. These data will be analyzed within a phylogenetic framework inferred from molecular sequence data collected for these clones to test how frequently different mechanisms of tolerance have evolved and which tolerance mechanism evolved first. In addition, by analyzing these physiological data together with environmental sulfide data collected from our research sites using microelectrodes, we can also test whether the breadth of an organism's sulfide tolerance can be predicted from the magnitude of variation in environmental sulfide concentration it has experienced in its recent evolutionary past and whether greater average sulfide concentration and/or temporal variability in sulfide favors the evolution of a particular mechanism of sulfide tolerance.

  10. Iron-sulfide redox flow batteries

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Guanguang; Yang, Zhenguo; Li, Liyu; Kim, Soowhan; Liu, Jun; Graff, Gordon L

    2016-06-14

    Iron-sulfide redox flow battery (RFB) systems can be advantageous for energy storage, particularly when the electrolytes have pH values greater than 6. Such systems can exhibit excellent energy conversion efficiency and stability and can utilize low-cost materials that are relatively safer and more environmentally friendly. One example of an iron-sulfide RFB is characterized by a positive electrolyte that comprises Fe(III) and/or Fe(II) in a positive electrolyte supporting solution, a negative electrolyte that comprises S.sup.2- and/or S in a negative electrolyte supporting solution, and a membrane, or a separator, that separates the positive electrolyte and electrode from the negative electrolyte and electrode.

  11. Speciation of arsenic in sulfidic waters

    Directory of Open Access Journals (Sweden)

    Ford Robert G

    2003-03-01

    Full Text Available Formation constants for thioarsenite species have been determined in dilute solutions at 25°C, ΣH2S from 10-7.5 to 10-3.0 M, ΣAs from 10-5.6 to 10-4.8 M, and pH 7 and 10. The principal inorganic arsenic species in anoxic aquatic systems are arsenite, As(OH30, and a mononuclear thioarsenite with an S/As ratio of 3:1. Thioarsenic species with S/As ratios of 1 : 1,2 : 1, and 4 : 1 are lesser components in sulfidic solutions that might be encountered in natural aquatic environments. Thioarsenites dominate arsenic speciation at sulfide concentrations > 10-4.3 M at neutral pH. Conversion from neutral As(OH30 to anionic thioarsenite species may regulate the transport and fate of arsenic in sulfate-reducing environments by governing sorption and mineral precipitation reactions.

  12. Iron-sulfide redox flow batteries

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Guan-Guang; Yang, Zhenguo; Li, Liyu; Kim, Soowhan; Liu, Jun; Graff, Gordon L

    2013-12-17

    Iron-sulfide redox flow battery (RFB) systems can be advantageous for energy storage, particularly when the electrolytes have pH values greater than 6. Such systems can exhibit excellent energy conversion efficiency and stability and can utilize low-cost materials that are relatively safer and more environmentally friendly. One example of an iron-sulfide RFB is characterized by a positive electrolyte that comprises Fe(III) and/or Fe(II) in a positive electrolyte supporting solution, a negative electrolyte that comprises S.sup.2- and/or S in a negative electrolyte supporting solution, and a membrane, or a separator, that separates the positive electrolyte and electrode from the negative electrolyte and electrode.

  13. Subsurface heaters with low sulfidation rates

    Energy Technology Data Exchange (ETDEWEB)

    John, Randy Carl; Vinegar, Harold J

    2013-12-10

    A system for heating a hydrocarbon containing formation includes a heater having an elongated ferromagnetic metal heater section. The heater is located in an opening in a formation. The heater section is configured to heat the hydrocarbon containing formation. The exposed ferromagnetic metal has a sulfidation rate that goes down with increasing temperature of the heater, when the heater is in a selected temperature range.

  14. Efficiently Dispersing Carbon Nanotubes in Polyphenylene Sulfide

    OpenAIRE

    Sommer, Kevin M; Pipes, R. Byron

    2013-01-01

    Thermal plastics are replacing conventional metals in the aerospace, sporting, electronics, and other industries. Thermal plastics are able to withstand relatively high temperatures, have good fatigue properties, and are lighter than metals. Unfortunately, they are not very electrically conductive. However, adding carbon nanotubes to thermal plastics such as polyphenylene sulfide (PPS) can drastically increase the plastic's conductivity at a low weight percent of nanotubes called the percolat...

  15. Hydrogen sulfide prodrugs—a review

    Directory of Open Access Journals (Sweden)

    Yueqin Zheng

    2015-09-01

    Full Text Available Hydrogen sulfide (H2S is recognized as one of three gasotransmitters together with nitric oxide (NO and carbon monoxide (CO. As a signaling molecule, H2S plays an important role in physiology and shows great potential in pharmaceutical applications. Along this line, there is a need for the development of H2S prodrugs for various reasons. In this review, we summarize different H2S prodrugs, their chemical properties, and some of their potential therapeutic applications.

  16. Hydrogen sulfide prodrugs—a review

    Science.gov (United States)

    Zheng, Yueqin; Ji, Xingyue; Ji, Kaili; Wang, Binghe

    2015-01-01

    Hydrogen sulfide (H2S) is recognized as one of three gasotransmitters together with nitric oxide (NO) and carbon monoxide (CO). As a signaling molecule, H2S plays an important role in physiology and shows great potential in pharmaceutical applications. Along this line, there is a need for the development of H2S prodrugs for various reasons. In this review, we summarize different H2S prodrugs, their chemical properties, and some of their potential therapeutic applications. PMID:26579468

  17. Solid Phase Synthesis of Ethyl β-Substituted Indolepropionates

    Institute of Scientific and Technical Information of China (English)

    刘占祥; 阮秀秀; 黄宪

    2003-01-01

    A facile solid phase synthesis of ethyl β-substituted indolepropionates is reported. Condensation between indole, polymer-supported cyclic malonic acid ester and aldehyde yielded the trimolecular adducts, which was cleaved by pyridine/EtOH to release the final products in good yield with high purity.

  18. (Z-Ethyl 2-(3-nitrobenzylidene-3-oxobutanoate

    Directory of Open Access Journals (Sweden)

    Xiaopeng Shi

    2008-12-01

    Full Text Available The title molecule, C13H13NO5, adopts a Z conformation at the C= C double bond. The ethoxy atoms of the ethyl ester group are disordered over two orientations in a 3:2 ratio. Weak intermolecular C—H...O hydrogen bonds help to establish the packing.

  19. Kinetics of Ethyl Acetate Synthesis Catalyzed by Acidic Resins

    Science.gov (United States)

    Antunes, Bruno M.; Cardoso, Simao P.; Silva, Carlos M.; Portugal, Ines

    2011-01-01

    A low-cost experiment to carry out the second-order reversible reaction of acetic acid esterification with ethanol to produce ethyl acetate is presented to illustrate concepts of kinetics and reactor modeling. The reaction is performed in a batch reactor, and the acetic acid concentration is measured by acid-base titration versus time. The…

  20. The ototoxic effects of ethyl benzene in rats

    NARCIS (Netherlands)

    Cappaert, N.L.M.; Klis, S.F.L.; Muijser, H.; Groot, J.C.M.J. de; Kulig, B.M.; Smoorenburg, G.F.

    1999-01-01

    Exposure to organic solvents has been shown to be ototoxic in animals and there is evidence that these solvents can induce hearing loss in humans. In this study, the effects of inhalation of the possibly ototoxic solvent ethyl benzene on the cochlear function and morphology were evaluated using thre

  1. Synthesis of Poly(2-Chloro Ethyl Vinylether) and Its Derivatives

    NARCIS (Netherlands)

    Nuyken, O.; Rieß, G.; Loontjens, J.A.; Linde, R. van der

    1995-01-01

    The cationic polymerization of 2-chloro ethyl vinylether (CEVE) is initiated by 1-iodo-1-(2-methylpropyloxy)ethane/(n-Bu)4NClO4. The monomer is consumed following first order kinetics. Molar masses are controlled by the ratio [M]:[I]. A rather narrow molar mass distribution is obtained. These observ

  2. 1-Ethyl-3-(2,4,6-trimethylphenylimidazolium tetrafluoroborate

    Directory of Open Access Journals (Sweden)

    Jin-Tao Guan

    2010-08-01

    Full Text Available The title compound, C14H19N2+·BF4−, was obtained by reaction of 1-ethyl-3-(2,4,6-trimethylphenylimidazolium tetrafluoroborate with sodium tetrafluoroborate. The imidazole ring makes a dihedral angle of 78.92 (13° with the benzene ring.

  3. Dissociation of the Ethyl Radical: An Exercise in Computational Chemistry

    Science.gov (United States)

    Nassabeh, Nahal; Tran, Mark; Fleming, Patrick E.

    2014-01-01

    A set of exercises for use in a typical physical chemistry laboratory course are described, modeling the unimolecular dissociation of the ethyl radical to form ethylene and atomic hydrogen. Students analyze the computational results both qualitatively and quantitatively. Qualitative structural changes are compared to approximate predicted values…

  4. Microaeration for hydrogen sulfide removal in UASB reactor.

    Science.gov (United States)

    Krayzelova, Lucie; Bartacek, Jan; Kolesarova, Nina; Jenicek, Pavel

    2014-11-01

    The removal of hydrogen sulfide from biogas by microaeration was studied in Up-flow Anaerobic Sludge Blanket (UASB) reactors treating synthetic brewery wastewater. A fully anaerobic UASB reactor served as a control while air was dosed into a microaerobic UASB reactor (UMSB). After a year of operation, sulfur balance was described in both reactors. In UASB, sulfur was mainly presented in the effluent as sulfide (49%) and in biogas as hydrogen sulfide (34%). In UMSB, 74% of sulfur was detected in the effluent (41% being sulfide and 33% being elemental sulfur), 10% accumulated in headspace as elemental sulfur and 9% escaped in biogas as hydrogen sulfide. The efficiency of hydrogen sulfide removal in UMSB was on average 73%. Microaeration did not cause any decrease in COD removal or methanogenic activity in UMSB and the elemental sulfur produced by microaeration did not accumulate in granular sludge. PMID:25270045

  5. Sulfide scaling in low enthalpy geothermal environments; A survey

    Energy Technology Data Exchange (ETDEWEB)

    Criaud, A.; Fouillac, C. (Bureau de Recherches Geologiques et Minieres (BRGM), 45 - Orleans (France))

    1989-01-01

    A review of the sulfide scaling phenomena in low-temperature environments is presented. While high-temperature fluids tend to deposit metal sulfides because of their high concentrations of dissolved metals and variations of temperature, pressure and fluid chemistry, low temperature media are characterized by very low metal content but much higher dissolved sulfide. In the case of the goethermal wells of the Paris Basin, detailed studies demonstrate that the relatively large concentrations of chloride and dissolved sulfide are responsible for corrosion and consequent formation of iron sulfide scale composed of mackinawite, pyrite and pyrrhotite. The effects of the exploitation schemes are far less important than the corrosion of the casings. The low-enthalpy fluids that do not originate from sedimentary aquifers (such as in Iceland and Bulgaria), have a limited corrosion potential, and the thin sulfide film that appears may prevent the progress of corrosion.

  6. Oxidation and Precipitation of Sulfide in Sewer Networks

    DEFF Research Database (Denmark)

    Nielsen, A. H.

    for the accumulation of metal sulfides in the biofilms. This was the case even when the iron concentration in the wastewater was increased approximately ten times compared to the in situ concentration. In aerobic biofilms, iron precipitation was apparently controlled by phosphate. Based on the experimental studies...... were studied in both wastewater and biofilms. Particular emphasis was on the importance of iron in the sulfur cycle. Iron is typically among the dominant metals in wastewater. The experiments showed that, ferric iron (Fe(III)) that was added to anaerobic wastewater was rapidly reduced to ferrous iron...... (Fe(II)) and precipitated subsequently with dissolved sulfide as ferrous sulfide (FeS). The ferrous sulfide precipitation was relatively fast, but not immediate. Despite the very low solubility of ferrous sulfide, initially present iron did not react completely with sulfide. This observation...

  7. Hydrogen Production via Steam Reforming of Ethyl Alcohol over Palladium/Indium Oxide Catalyst

    OpenAIRE

    Tetsuo Umegaki; Yusuke Yamada; Atsushi Ueda; Nobuhiro Kuriyama; Qiang Xu

    2009-01-01

    We report the synergetic effect between palladium and indium oxide on hydrogen production in the steam reforming reaction of ethyl alcohol. The palladium/indium oxide catalyst shows higher hydrogen production rate than indium oxide and palladium. Palladium/indium oxide affords ketonization of ethyl alcohol with negligible by-product carbon monoxide, while indium oxide mainly affords dehydration of ethyl alcohol, and palladium affords decomposition of ethyl alcohol with large amount of by-prod...

  8. INVESTIGATIONS ON BIOCHEMICAL PURIFICATION OF GROUND WATER FROM HYDROGEN SULFIDE

    OpenAIRE

    Yu. P. Sedlukho; Yu. O. Stankevich

    2015-01-01

    The paper considers problems and features of biochemical removal of hydrogen sulfide from ground water. The analysis of existing methods for purification of ground water from hydrogen sulfide has been given in the paper. The paper has established shortcomings of physical and chemical purification of ground water. While using aeration methods for removal of hydrogen sulfide formation of colloidal sulfur that gives muddiness and opalescence to water occurs due to partial chemical air oxidation....

  9. Extraction of Nanosized Cobalt Sulfide from Spent Hydrocracking Catalyst

    OpenAIRE

    Samia A. Kosa; Hegazy, Eman Z.

    2013-01-01

    The processes used for the extraction of metals (Co, Mo, and Al) from spent hydrotreating catalysts were investigated in this study. A detailed mechanism of the metal extraction process is described. Additionally, a simulation study was performed to understand the sulfidizing mechanism. The suggested separation procedure was effective and achieved an extraction of approximately 80–90%. In addition, the sulfidization mechanism was identified. This sulfidizing process for Co was found to involv...

  10. Limitation of Sulfide Capacity Concept for Molten Slags

    Science.gov (United States)

    Jung, In-Ho; Moosavi-Khoonsari, Elmira

    2016-04-01

    The sulfide capacity concept has been widely used in pyrometallurgy to define sulfur removal capacities of slags. Typically, the sulfide capacity is considered to be a unique slag property depending only on temperature regardless of partial pressures of oxygen and sulfur. In the present study, it is demonstrated that sulfide capacities of slags in particular those of Na2O-containing slags can vary with partial pressures of oxygen and sulfur due to large solubility of sulfide in Na2O-containing slag systems.

  11. Influence of iron on sulfide inhibition in dark biohydrogen fermentation.

    Science.gov (United States)

    Dhar, Bipro Ranjan; Elbeshbishy, Elsayed; Nakhla, George

    2012-12-01

    Sulfide impact on biohydrogen production using dark fermentation of glucose at 37 °C was investigated. Dissolved sulfide (S(2-)) at a low concentration (25mg/L) increased biohydrogen production by 54% relative to the control (without iron addition). Whereas on initial dissolved S(2-) concentration of 500 mg/L significantly inhibited the biohydrogen production with total cumulative biohydrogen decreasing by 90% compared to the control (without iron addition). At sulfide concentrations of 500 mg S(2-)/L, addition of Fe(2+) at 3-4 times the theoretical requirement to precipitate 100% of the dissolved S(2-) entirely eliminated the inhibitory effect of sulfide.

  12. Comparison of formalin-ethyl ether sedimentation, formalin-ethyl acetate sedimentation, and zinc sulfate flotation techniques for detection of intestinal parasites.

    OpenAIRE

    Truant, A L; Elliott, S H; Kelly, M T; Smith, J. H.

    1981-01-01

    Formalin-ethyl ether sedimentation, Formalin-ethyl acetate sedimentation, and zinc sulfate flotation techniques were compared using over 250 clinical parasitology specimens. Fifty positive specimens were identified, and a variety of parasites, including amoebae, flagellates, cestodes, nematodes, and trematodes, were encountered. The Formalin-ether and Formalin-ethyl acetate sedimentation procedures gave identical results for the detection of cysts, ova, and larvae, and these methods offered a...

  13. MEASURING METAL SULFIDE COMPLEXES IN OXIC RIVER WATERS WITH SQUARE WAVE VOLTAMMETRY. (R825395)

    Science.gov (United States)

    A sulfide identification protocol was developed to quantify specific metal sulfides that could exist in river water. Using a series of acid additions, nitrogen purges, and voltammetric analyses, metal sulfides were identified and semiquantified in three specific gr...

  14. Modeling Sulfides, pH and Hydrogen Sulfide Gas in the Sewers of San Francisco

    DEFF Research Database (Denmark)

    Vollertsen, Jes; Revilla, Nohemy; Hvitved-Jacobsen, Thorkild;

    2015-01-01

    An extensive measuring campaign targeted on sewer odor problems was undertaken in San Francisco. It was assessed whether a conceptual sewer process model could reproduce the measured concentrations of total sulfide in the wastewater and H2S gas in the sewer atmosphere, and to which degree...

  15. Reactions of methyl and ethyl radicals with uranium hexafluoride

    Science.gov (United States)

    Lyman, John L.; Laguna, Glenn

    1985-01-01

    We have measured the rates of reaction of both methyl and ethyl radicals with uranium hexafluoride (UF6) in the gas phase. The method we used was to photolyze samples of UF6 in the presence of either methane or ethane. The radicals produced by reaction of fluorine atoms with these species then react with either themselves or with UF6. We inferred the rate constants from ratios of the reaction products and the published rate constants for radical recombination. The diagnostic technique was gas chromatography. The resulting rate constants for reaction with UF6 were (1.6±0.8)×10-14 cm3 molecule-1 s-1 for methyl radicals and (4±2)×10-11 cm3 molecule-1 s-1 for ethyl radicals.

  16. Structural analysis of 1-ethyl-3-methylimidazolium bifluoride melt

    Science.gov (United States)

    Matsumoto, Kazuhiko; Hagiwara, Rika; Ito, Yasuhiko; Kohara, Shinji; Suzuya, Kentaro

    2003-01-01

    The structure of 1-ethyl-3-methylimidazolium bifluoride (EMImF · HF) melt has been analyzed at 333 K by a high-energy synchrotron X-ray diffraction method. The total correlation function of the EMImF · HF melt was similar to that of the solid state, indicating that not only the short range but also the intermediate-range ordering in the solid are partially preserved in the liquid state. The intra-molecular F-F correlation in the anions clearly appears in the total correlation function of the EMImF · HF melt, whereas prominent peaks are not observed in the case of a room temperature molten salt, 1-ethyl-3-methylimidazolium fluorohydrogenate.

  17. Structural analysis of 1-ethyl-3-methylimidazolium bifluoride melt

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Kazuhiko; Hagiwara, Rika. E-mail: hagiwara@energy.kyoto-u.ac.jp; Ito, Yasuhiko; Kohara, Shinji; Suzuya, Kentaro

    2003-01-01

    The structure of 1-ethyl-3-methylimidazolium bifluoride (EMImF {center_dot} HF) melt has been analyzed at 333 K by a high-energy synchrotron X-ray diffraction method. The total correlation function of the EMImF {center_dot} HF melt was similar to that of the solid state, indicating that not only the short range but also the intermediate-range ordering in the solid are partially preserved in the liquid state. The intra-molecular F-F correlation in the anions clearly appears in the total correlation function of the EMImF {center_dot} HF melt, whereas prominent peaks are not observed in the case of a room temperature molten salt, 1-ethyl-3-methylimidazolium fluorohydrogenate.

  18. Effect of ethyl oleate on drying characteristics of mulberries.

    Science.gov (United States)

    Doymaz, Ibrahim; Pala, Mehmet

    2003-10-01

    In this study, air-drying experiments in thin layers of mulberry grown in Istanbul, Turkey, were conducted. The effect of ethyl oleate solution on drying time of mulberry samples was investigated in a pilot air-dryer. When ethyl oleate was used as pretreatment solution, the drying time of samples was decreased. Drying curves were obtained using the Page model. The effective diffusivity varied from 2.326 x 10(-10) to 1.809 x 10(-9) m2/s the temperature range. The temperature dependence of the diffusivity coefficient was described by the Arrhenius type relationship. The activation energy for moisture diffusion was found to be 50.87 kJ/mol for treated samples and 51.85 kJ/mol for untreated samples. PMID:14609084

  19. Preparation of ethyl magnesium bromide for regiospecific analysis of triacylglycerols.

    Science.gov (United States)

    Ando, Yasuhiro; Tomita, Yuki; Haba, Yusuke

    2008-01-01

    This paper presents a procedure for preparation of a Grignard reagent, ethyl magnesium bromide, used for partial deacylation of triacylglycerols (TAG) in their regiospecific analysis. Magnesium turnings were reacted with ethereal solution of bromoethane in a screw-capped test tube to synthesize 2 mL of 1 M ethyl magnesium bromide. Continuously stirred with a vortex mixer, the reaction smoothly proceeded at room temperature. Regiospecific analysis of 1,3-distearoyl-2-oleoylglycerol using this product showed that fatty acid compositions of the sn-1(3) and sn-2 positions were contaminated by less than 2 mol% of fatty acids migrated from isomeric positions. The analyses of lard and cod liver/mackerel oil TAG showed typical distribution patterns of 16:0, 22:5n-3 and 22:6n-3 in pig and fish depot TAG. These results confirmed the view that the freshly prepared reagent is usable for regiospecific analysis of TAG.

  20. Elevated plasma creatinine due to creatine ethyl ester use.

    Science.gov (United States)

    Velema, M S; de Ronde, W

    2011-02-01

    Creatine is a nutritional supplement widely used in sport, physical fitness training and bodybuilding. It is claimed to enhance performance. We describe a case in which serum creatinine is elevated due to the use of creatine ethyl esther. One week after withdrawal, the plasma creatinine had normalised. There are two types of creatine products available: creatine ethyl esther (CEE) and creatine monohydrate (CM). Plasma creatinine is not elevated in all creatine-using subjects. CEE , but not CM, is converted into creatinine in the gastrointestinal tract. As a result the use of CEE may be associated with elevated plasma creatinine levels. Since plasma creatinine is a widely used marker for renal function, the use of CEE may lead to a false assumption of renal failure.

  1. Solubility of hydrogen sulfide in water

    International Nuclear Information System (INIS)

    The solubility of hydrogen sulfide in water, which is of importance in the design and analysis of the dual temperature process for the production of heavy water, has been measured in the temperature range 100 - 1800C at pressures up to 6670 kPa or the hydrate/H2S-rich liquid locus, whichever is lower at the particular temperature. Limited vapor phase data at 900, 1200, and 1500C were also obtained. Henry's coefficients have been determined from the experimental data. (orig./HK)

  2. Oxidation of Reduced Sulfur Species: Carbonyl Sulfide

    DEFF Research Database (Denmark)

    Glarborg, Peter; Marshall, Paul

    2013-01-01

    A detailed chemical kinetic model for oxidation of carbonyl sulfide (OCS) has been developed, based on a critical evaluation of data from the literature. The mechanism has been validated against experimental results from batch reactors, flow reactors, and shock tubes. The model predicts...... satisfactorily oxidation of OCS over a wide range of stoichiometric air–fuel ratios (0.5 ≤λ≤7.3), temperatures (450–1700 K), and pressures (0.02–3.0 atm) under dry conditions. The governing reaction mechanisms are outlined based on calculations with the kinetic model. The oxidation rate of OCS is controlled...

  3. Normal State of the Metallic Hydrogen Sulfide

    OpenAIRE

    Kudryashov, Nikolay A.; Kutukov, Alexander A.; Mazur, Evgeny A.

    2016-01-01

    Generalized theory of the normal properties of the metal in the case of the electron-phonon (EP) systems with not constant density of electronic states is used to examine the normal state of the SH3 and SH2 phase of the hydrogen sulfide at different pressures. The frequency dependence of the real and imaginary part of the self-energy part (SP) of the electron Green's function, the real and imaginary part of the complex renormalization of the electron mass, the real and imaginary part of the c...

  4. Adsorption-Desorption Characteristics of Chlorimuron-Ethyl in Soils

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The adsorption-desorption characteristics of chlorimuron-ethyl in soils were investigated to provide the basic data for evaluating the safety in field and the risk to water resource. The adsorption-desorption experiment was conducted by the batch equilibration and HPLC techniques; furthermore, data were analyzed with 5 mathematic models to describe the characteristics and mechanism of adsorption-desorption and translocation of the herbicide in soils. The results showed that the adsorption-desorption isotherms of chlorimuron-ethyl fitted for the Freundlich model well, and the physical reaction presents the main contribution during the adsorption-desorption process. The adsorption values (Kads-f) of chlorimuron-ethyl in 8 types of soil ranged from 0.798 to 6.891. The isotherms of 2# (Jiangxi clay) and 3# (Jiangxi sand loam)soils belong to the S-type curve, while the isotherms of another 6 type soils belong to the L-type isotherm. The results of desorption indicated that the hysteresis phenomena appeared during the desorption process, and the hysteresis coefficients(H) of the herbicides in 8 soils varied from 0.259-0.980. Furthermore, Kads-f and desorption values (Kdes-f) increased with the OM (%) and the clay content increasing, while the values decreased with the soils pH increasing. The H values decreased with the OM and the clay content increasing, and increased with the soils pH increasing. It can be concluded that the low adsorption abilities of chlorimuron-ethyl in test soils and un-reversible adsorption existed in the process, which will induce the great translocation of the herbicide after application in field. It can be transported to ground or groundwater causing risk to environments. The physical and chemical properties of soils, including the OM, the clay content, and the pH of soil were the dominating factors during the adsorption-desorption.

  5. Synthesis of new radiotracers based of Ethyl Ester

    International Nuclear Information System (INIS)

    The in vivo study of a biochemical or physiological process requires the synthesis of specific radiotracers but also the targeting of these compounds so that they can reach their target tissue. Methodologies original synthesis associated with radioisotopes used, the quantities and chemical forms often have to be available developed. The chemistry of metal complexes booming, we were able to use the ethyl ester combined with technetium, forming a stable radiotracer. Finally, a counting of radioactivity in different rat's organs completed our study. (Author)

  6. Mouse Mutagenesis Using N-Ethyl-N-Nitrosourea (ENU)

    OpenAIRE

    sprotocols

    2014-01-01

    Authors: Andrew P. Salinger and Monica J. Justice1 Corresponding author ([]()) ### INTRODUCTION This protocol describes chemical mutagenesis of male mice using N-ethyl-N-nitrosourea (ENU), which is the most efficient method for obtaining mouse mutations in phenotype-driven screens. A fractionated dose of ENU, an alkylating agent, can produce a mutation rate as high as 1.5 × 10e−3 in male mouse spermatogonial stem cells. Treatment with ENU pr...

  7. Measurement and Correlation of Solubilityof Ethyl Nitrite in Mixed Solvent

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    An experimental apparatus was used to measure the solubility of ethylnitrite in mixedsolvents under the lower pressure and higher temperature. The solubilitiesof ethyl nitrite inmixed solvents of ethanol-water at 15° C---40° C and ethanol-diethyloxalate at 20° C---40° C weredetermined. A Henry constant model has been improved, and the interaction parameters havebeen fitted from experimental data. The calculation results have been compared withexperimental data; the results obtained are satisfactory.

  8. Sensory reception of the primer pheromone ethyl oleate

    Science.gov (United States)

    Muenz, Thomas S.; Maisonnasse, Alban; Plettner, Erika; Le Conte, Yves; Rössler, Wolfgang

    2012-05-01

    Social work force distribution in honeybee colonies critically depends on subtle adjustments of an age-related polyethism. Pheromones play a crucial role in adjusting physiological and behavioral maturation of nurse bees to foragers. In addition to primer effects of brood pheromone and queen mandibular pheromone—both were shown to influence onset of foraging—direct worker-worker interactions influence adult behavioral maturation. These interactions were narrowed down to the primer pheromone ethyl oleate, which is present at high concentrations in foragers, almost absent in young bees and was shown to delay the onset of foraging. Based on chemical analyses, physiological recordings from the antenna (electroantennograms) and the antennal lobe (calcium imaging), and behavioral assays (associative conditioning of the proboscis extension response), we present evidence that ethyl oleate is most abundant on the cuticle, received by olfactory receptors on the antenna, processed in glomeruli of the antennal lobe, and learned in olfactory centers of the brain. The results are highly suggestive that the primer pheromone ethyl oleate is transmitted and perceived between individuals via olfaction at close range.

  9. 21 CFR 73.2995 - Luminescent zinc sulfide.

    Science.gov (United States)

    2010-04-01

    ... coloring externally applied facial makeup preparations and nail polish included under § 720.4(c)(7)(ix) and... zinc sulfide in facial makeup preparations shall not exceed 10 percent by weight of the final product. (2) Facial makeup preparations containing luminescent zinc sulfide are intended for use only...

  10. Effect of Soluble Sulfide on the Activity of Luminescent Bacteria

    Directory of Open Access Journals (Sweden)

    Feng Wang

    2012-05-01

    Full Text Available Sulfide is an important water pollutant widely found in industrial waste water that has attracted much attention. S2−, as a weak acidic anion, is easy hydrolyzed to HS and H2S in aqueous solution. In this study, biological tests were performed to establish the toxicity of sulfide solutions on luminescent bacteria. Considering the sulfide solution was contained three substances—S2−, HS and H2S—the toxicity test was performed at different pH values to investigate which form of sulfide increased light emission and which reduced light emission. It was shown that the EC50 values were close at pH 7.4, 8.0 and 9.0 which were higher than pH 5 and 10. The light emission and sulfide concentrations displayed an inverse exponential dose-response relationship within a certain concentration range at pH 5, 6.5 and 10. The same phenomenon occurred for the high concentration of sulfide at pH 7.4, 8 and 9, in which the concentration of sulfide was HS >> H2S > S2−. An opposite hormesis-effect appeared at the low concentrations of sulfide.

  11. Hydrogen sulfide: physiological properties and therapeutic potential in ischaemia.

    Science.gov (United States)

    Bos, Eelke M; van Goor, Harry; Joles, Jaap A; Whiteman, Matthew; Leuvenink, Henri G D

    2015-03-01

    Hydrogen sulfide (H2 S) has become a molecule of high interest in recent years, and it is now recognized as the third gasotransmitter in addition to nitric oxide and carbon monoxide. In this review, we discuss the recent literature on the physiology of endogenous and exogenous H2 S, focusing upon the protective effects of hydrogen sulfide in models of hypoxia and ischaemia.

  12. 40 CFR 425.03 - Sulfide analytical methods and applicability.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Sulfide analytical methods and applicability. 425.03 Section 425.03 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... § 425.03 Sulfide analytical methods and applicability. (a) The potassium ferricyanide titration...

  13. Hydrogen Sulfide and Polysulfides as Biological Mediators

    Directory of Open Access Journals (Sweden)

    Hideo Kimura

    2014-10-01

    Full Text Available Hydrogen sulfide (H2S is recognized as a biological mediator with various roles such as neuromodulation, regulation of the vascular tone, cytoprotection, anti-inflammation, oxygen sensing, angiogenesis, and generation of mitochondrial energy. It is produced by cystathionine β-synthase (CBS, cystathionine γ-lyase (CSE, and 3-mercaptopyruvate sulfurtransferase (3MST. The activity of CBS is enhanced by S-adenosyl methionine (SAM and glutathionylation, while it is inhibited by nitric oxide (NO and carbon monoxide (CO. The activity of CSE and cysteine aminotransferase (CAT, which produces the 3MST substrate 3-mercaptopyruvate (3MP, is regulated by Ca2+. H2S is oxidized to thiosulfate in mitochondria through the sequential action of sulfide quinone oxidoreductase (SQR, sulfur dioxygenase, and rhodanese. The rates of the production and clearance of H2S determine its cellular concentration. Polysulfides (H2Sn have been found to occur in the brain and activate transient receptor potential ankyrin 1 (TRPA1 channels, facilitate the translocation of nuclear factor erythroid 2-related factor 2 (Nrf2 to the nucleus, and suppress the activity of phosphatase and tensin homolog (PTEN by sulfurating (sulfhydrating the target cysteine residues. A cross talk between H2S and NO also plays an important role in cardioprotection as well as regulation of the vascular tone. H2S, polysulfides, and their cross talk with NO may mediate various physiological and pathophysiological responses.

  14. Calculation of sulfide capacities of multicomponent slags

    Science.gov (United States)

    Pelton, Arthur D.; Eriksson, Gunnar; Romero-Serrano, Antonio

    1993-10-01

    The Reddy-Blander model for the sulfide capacities of slags has been modified for the case of acid slags and to include A12O3 and TiO2 as components. The model has been extended to calculate a priori sulfide capacities of multicomponent slags, from a knowledge of the thermodynamic activities of the component oxides, with no adjustable parameters. Agreement with measurements is obtained within experimental uncertainty for binary, ternary, and quinary slags involving the components SiO2-Al2O3-TiO2-CaO-MgO-FeO-MnO over wide ranges of composition. The oxide activities used in the computations are calculated from a database of model parameters obtained by optimizing thermodynamic and phase equilibrium data for oxide systems. Sulfur has now been included in this database. A computing system with automatic access to this and other databases has been developed to permit the calculation of the sulfur content of slags in multicomponent slag/metal/gas/solid equilibria.

  15. First detection of doubly deuterated hydrogen sulfide

    CERN Document Server

    Vastel, C; Ceccarelli, C; Pearson, J

    2003-01-01

    This work was carried out with using the Caltech Submillimeter Observatory and presents the observational study of HDS and D2S towards a sample of Class 0 sources, and dense cores. We report the first detection of doubly deuterated hydrogen sulfide (D2S) in two dense cores and analyze the chemistry of these molecules aiming to help understand the deuteration processes in the interstellar medium. The observed values of the D2S/HDS ratio, and upper limits, require an atomic D/H ratio in the accreting gas of 0.1-1. The study presented in this Letter supports the hypothesis that formaldehyde, methanol and hydrogen sulfide are formed on the grain surfaces, during the cold pre-stellar core phase, where the CO depleted gas has large atomic D/H ratios. The high values for the D/H ratios are consistent with the predictions of a recent gas-phase chemical model that includes H3+ and its deuterated isotopomers, H2D+, D2H+ and D3+ (Roberts et al. 2003).

  16. Phase diagram measurements by Heat-flux DSC and thermodynamic calculations of the mixture of the Esters Ethyl undecanoate (C13H26O2) and Ethyl tridecanoate (C15H30O2)

    NARCIS (Netherlands)

    Schaftenaar, H.P.C.

    2006-01-01

    In this report a phase diagram is determined by heat flux DSC of the binary mixture Ethyl undecanoate and Ethyl tridecanoate. Our hypothesis for equilibrium phase behaviour is that the components Ethyl undecanoate and Ethyl tridecanoate do have the same crystal form and they have restricted miscibil

  17. Hierarchical Architecturing for Layered Thermoelectric Sulfides and Chalcogenides

    Directory of Open Access Journals (Sweden)

    Priyanka Jood

    2015-03-01

    Full Text Available Sulfides are promising candidates for environment-friendly and cost-effective thermoelectric materials. In this article, we review the recent progress in all-length-scale hierarchical architecturing for sulfides and chalcogenides, highlighting the key strategies used to enhance their thermoelectric performance. We primarily focus on TiS2-based layered sulfides, misfit layered sulfides, homologous chalcogenides, accordion-like layered Sn chalcogenides, and thermoelectric minerals. CS2 sulfurization is an appropriate method for preparing sulfide thermoelectric materials. At the atomic scale, the intercalation of guest atoms/layers into host crystal layers, crystal-structural evolution enabled by the homologous series, and low-energy atomic vibration effectively scatter phonons, resulting in a reduced lattice thermal conductivity. At the nanoscale, stacking faults further reduce the lattice thermal conductivity. At the microscale, the highly oriented microtexture allows high carrier mobility in the in-plane direction, leading to a high thermoelectric power factor.

  18. Effect of palladium on sulfide tarnishing of noble metal alloys.

    Science.gov (United States)

    Suoninen, E; Herø, H; Minni, E

    1985-10-01

    Electron spectroscopic studies of Au-Ag-Cu alloys of the type used for dental castings show that small additions (less than or equal to 3 wt%) of palladium reduce essentially the thickness of the sulfide layer formed on surfaces of samples treated in aqueous Na2S solutions. Relative to silver, palladium does not enrich in the sulfide, but statistically significant enrichment is found immediately below the sulfide layer. This enrichment probably takes place during the exposure of the substrate surface to atmosphere before the sulfiding treatment. The mechanism of the impeding effect of palladium on sulfiding is assumed to be a decrease in diffusion from the bulk alloy to the surface due to the enriched layer. The effect cannot be explained by changes in the electronic structure of the alloy due to palladium alloying.

  19. Influence of Water Salinity on Air Purification from Hydrogen Sulfide

    Directory of Open Access Journals (Sweden)

    Leybovych L.I.

    2015-12-01

    Full Text Available Mathematical modeling of «sliding» water drop motion in the air flow was performed in software package FlowVision. The result of mathematical modeling of water motion in a droplet with diameter 100 microns at the «sliding» velocity of 15 m/s is shown. It is established that hydrogen sulfide oxidation occurs at the surface of phases contact. The schematic diagram of the experimental setup for studying air purification from hydrogen sulfide is shown. The results of the experimental research of hydrogen sulfide oxidation by tap and distilled water are presented. The dependence determining the share of hydrogen sulfide oxidized at the surface of phases contact from the dimensionless initial concentration of hydrogen sulfide in the air has been obtained.

  20. DISSOLUTION OF PLUTONIUM CONTAINING CARRIER PRECIPITATE BY CARBONATE METATHESIS AND SEPARATION OF SULFIDE IMPURITIES THEREFROM BY SULFIDE PRECIPITATION

    Science.gov (United States)

    Duffield, R.B.

    1959-07-14

    A process is described for recovering plutonium from foreign products wherein a carrier precipitate of lanthanum fluoride containing plutonium is obtained and includes the steps of dissolving the carrier precipitate in an alkali metal carbonate solution, adding a soluble sulfide, separating the sulfide precipitate, adding an alkali metal hydroxide, separating the resulting precipitate, washing, and dissolving in a strong acid.

  1. Determination of low concentrations of the flotation reagent ethyl xanthate by sampled DC polarography and flow injection with amperometric detection.

    Science.gov (United States)

    Hidalgo, P; Gutz, I G

    2001-04-12

    A polarographic DC(tast) method with the static mercury drop electrode, SMDE, was developed for determination of the flotation collector ethyl xanthate (EtX) in the concentration range from 1x10(-5) to 8x10(-5) M. The potentiality of the method was demonstrated by evaluating the capacity of powdered galena ore (PbS) to adsorb EtX in a titration-like procedure. Sulfide could be determined simultaneously with EtX because in NaOH electrolyte their anodic waves are well separated (E(1/2) congruent with-0.72 and -0.42 V versus Ag/AgCl, respectively). In addition, a new FIA method was developed by adapting a simple device to the tip of the glass capillary of a mercury electrode and doing amperometric detection at a fixed potential of -0.1 V, always in the DC(tast) mode. No oxygen removal was required. Reproducible results were obtained at a frequency of 72 injections per h, with automatic renewal of the SMDE every second. The calibration curve for freshly prepared EtX standards rendered a straight line from 5x10(-6) to 8x10(-5) M with correlation coefficient of 0.997, suitable for real applications in flotation processes and its effluents. PMID:18968265

  2. Gas chromatography-mass spectrometry of ethyl palmitate calibration and resolution with ethyl oleate as biomarker ethanol sub acute in urine application study

    Science.gov (United States)

    Suaniti, Ni Made; Manurung, Manuntun

    2016-03-01

    Gas Chromatography-Mass Spectrometry is used to separate two and more compounds and identify fragment ion specific of biomarker ethanol such as palmitic acid ethyl ester (PAEE), as one of the fatty acid ethyl esters as early detection through conyugated reaction. This study aims to calibrate ethyl palmitate and develop analysis with oleate acid. This methode can be used analysis ethanol and its chemistry biomarker in ethanol sub-acute consumption as analytical forensic toxicology. The result show that ethanol level in urine rats Wistar were 9.21 and decreased 6.59 ppm after 48 hours consumption. Calibration curve of ethyl palmitate was y = 0.2035 x + 1.0465 and R2 = 0.9886. Resolution between ethyl palmitate and oleate were >1.5 as good separation with fragment ion specific was 88 and the retention time was 18 minutes.

  3. Synthesis of Diaryl Ethers, Diaryl Sulfides, Heteroaryl Ethers and Heteroaryl Sulfides under Microwave Heating

    Institute of Scientific and Technical Information of China (English)

    LI,Feng; ZOU,Jiong; WANG,Quan-Rui; TAO,Feng-Gang

    2004-01-01

    @@ Diaryl ether moiety is found in a pool of naturally occurring and medicinally important compounds.[1] As a consequent, considerable efforts have been devoted to the assembly of this framework.[2] Recently, we have developed a microwave heating version of the synthesis of diaryl ethers as well as aryl sulfides. Under our conditions, even the extremely electron-poor 4-nitrophenol works well and its reaction with 1-halo-4-nitrobenzenes produces 4-(nitrophenoxy)-benzonitriles in satisfactory yield. The scope of the present protocol has been expanded to hydroxylated six-membered heterocycles as well as 2-pyrimidinethiol with mildly activated aryl halides, affording heteroaryl ethers and respectively sulfides. The advantages of the present method include the wide substrate scope, no use of any metal catalysts, the ease of product isolation and high yields.

  4. Atomic layer deposition of aluminum sulfide thin films using trimethylaluminum and hydrogen sulfide

    International Nuclear Information System (INIS)

    Sequential exposures of trimethylaluminum and hydrogen sulfide are used to deposit aluminum sulfide thin films by atomic layer deposition (ALD) in the temperature ranging from 100 to 200 °C. Growth rate of 1.3 Å per ALD cycle is achieved by in-situ quartz crystal microbalance measurements. It is found that the growth rate per ALD cycle is highly dependent on the purging time between the two precursors. Increased purge time results in higher growth rate. Surface limited chemistry during each ALD half cycle is studied by in-situ Fourier transformed infrared vibration spectroscopy. Time of flight secondary ion-mass spectroscopy measurement is used to confirm elemental composition of the deposited films

  5. Banded sulfide-magnetite ores of Mauk copper massive sulfide deposit, Central Urals: Composition and genesis

    Science.gov (United States)

    Safina, N. P.; Maslennikov, V. V.; Maslennikova, S. P.; Kotlyarov, V. A.; Danyushevsky, L. V.; Large, R. R.; Blinov, I. A.

    2015-05-01

    The results of investigation of metamorphosed sulfide-magnetite ores from the Mauk deposit located within the Main Ural Fault at the junction of Tagil and Magnitogorsk massive sulfide zones are discussed. The ore-hosting sequence comprises metamorphic rocks formed from basalt, carbonaceous and carbonaceous-cherty siltstone, and lenticular serpentinized ultramafic bodies. The ores of the deposit are represented by banded varieties and less frequent breccia. The clastic origin of the banded ore is indicated by load casts at the bottom of sulfide beds, alternation of sulfide and barren beds, and the truncation of the growth zones of pyrite crystals. Pyrite, pyrrhotite, chalcopyrite, sphalerite, and magnetite are the major minerals of the banded ores. The internal structure of the listed minerals testifies to the deep metamorphic recrystallization of primary hydrothermal-sedimentary ores accompanied with deformation. Cubanite, pyrrhotite, mackinawite, greigite, and gold are enclosed in metacrysts of pyrite, magnetite, and chalcopyrite. The accessory minerals of the Pb-Bi-Te, Bi-Te, and Ag-Te systems as well as uraninite have been found at the Mauk deposit for the first time. Magnetite predominantly replaces pyrite and less frequently chalcopyrite, pyrrhotite, and gangue minerals. It was established that the major carriers of As and Co are crystals of metamorphic pyrite. Chalcopyrite is the major carrier of Zn, Sn, Te, Pb, Bi, and Ag. Admixture of Fe and Cu is typical of sphalerite, and Se and Ni are characteristic of pyrrhotite. Ti, V, Mn, Sb, As, Ba, and U are concentrated in magnetite. The banded ores of the Mauk deposit are suggested as having been transformed in several stages: diagenesis, anadiagenesis, epidiagenesis ( t 500°C).

  6. Azo dye decolorization assisted by chemical and biogenic sulfide

    Energy Technology Data Exchange (ETDEWEB)

    Prato-Garcia, Dorian [Laboratory for Research on Advanced Processes for Water Treatment, Unidad Académica Juriquilla, Instituto de Ingeniería, Universidad Nacional Autónoma de México, Blvd. Juriquilla 3001, Querétaro 76230 (Mexico); Cervantes, Francisco J. [División de Ciencias Ambientales, Instituto Potosino de Investigación Científica y Tecnológica, Camino a la Presa de San José 2055, San Luis Potosí 78216 (Mexico); Buitrón, Germán, E-mail: gbuitronm@ii.unam.mx [Laboratory for Research on Advanced Processes for Water Treatment, Unidad Académica Juriquilla, Instituto de Ingeniería, Universidad Nacional Autónoma de México, Blvd. Juriquilla 3001, Querétaro 76230 (Mexico)

    2013-04-15

    Highlights: ► Azo dyes were reduced efficiently by chemical and biogenic sulfide. ► Biogenic sulfide was more efficient than chemical sulfide. ► There was no competition between dyes and sulfate for reducing equivalents. ► Aromatic amines barely affected the sulfate-reducing process. -- Abstract: The effectiveness of chemical and biogenic sulfide in decolorizing three sulfonated azo dyes and the robustness of a sulfate-reducing process for simultaneous decolorization and sulfate removal were evaluated. The results demonstrated that decolorization of azo dyes assisted by chemical sulfide and anthraquinone-2,6-disulfonate (AQDS) was effective. In the absence of AQDS, biogenic sulfide was more efficient than chemical sulfide for decolorizing the azo dyes. The performance of sulfate-reducing bacteria in attached-growth sequencing batch reactors suggested the absence of competition between the studied azo dyes and the sulfate-reducing process for the reducing equivalents. Additionally, the presence of chemical reduction by-products had an almost negligible effect on the sulfate removal rate, which was nearly constant (94%) after azo dye injection.

  7. Azo dye decolorization assisted by chemical and biogenic sulfide

    International Nuclear Information System (INIS)

    Highlights: ► Azo dyes were reduced efficiently by chemical and biogenic sulfide. ► Biogenic sulfide was more efficient than chemical sulfide. ► There was no competition between dyes and sulfate for reducing equivalents. ► Aromatic amines barely affected the sulfate-reducing process. -- Abstract: The effectiveness of chemical and biogenic sulfide in decolorizing three sulfonated azo dyes and the robustness of a sulfate-reducing process for simultaneous decolorization and sulfate removal were evaluated. The results demonstrated that decolorization of azo dyes assisted by chemical sulfide and anthraquinone-2,6-disulfonate (AQDS) was effective. In the absence of AQDS, biogenic sulfide was more efficient than chemical sulfide for decolorizing the azo dyes. The performance of sulfate-reducing bacteria in attached-growth sequencing batch reactors suggested the absence of competition between the studied azo dyes and the sulfate-reducing process for the reducing equivalents. Additionally, the presence of chemical reduction by-products had an almost negligible effect on the sulfate removal rate, which was nearly constant (94%) after azo dye injection

  8. Sulfide elimination by intermittent nitrate dosing in sewer sediments

    Institute of Scientific and Technical Information of China (English)

    Yanchen Liu; Chen Wu; Xiaohong Zhou; David Z.Zhu; Hanchang Shi

    2015-01-01

    The formation of hydrogen sulfide in biofilms and sediments in sewer systems can cause severe pipe corrosions and health hazards,and requires expensive programs for its prevention.The aim of this study is to propose a new control strategy and the optimal condition for sulfide elimination by intermittent nitrate dosing in sewer sediments.The study was carried out based on lab-scale experiments and batch tests using real sewer sediments.The intermittent nitrate dosing mode and the optimal control condition were investigated.The results indicated that the sulfide-intermittent-elimination strategy by nitrate dosing is advantageous for controlling sulfide accumulation in sewer sediment.The oxidation-reduction potential is a sensitive indicator parameter that can reflect the control effect and the minimum N/S (nitrate/sulfide)ratio with slight excess nitrate is necessary for optimal conditions ofefficient sulfide control with lower carbon source loss.The opth-nal control condition is feasible for the sulfide elimination in sewer systems.

  9. MMT promises: how the Ethyl Corporation beat the federal ban

    International Nuclear Information System (INIS)

    The manganese-based MMT has been blended in gasoline fuel sold in Canada for almost 20 years. Invoking environmental health and consumer protection grounds, the federal government moved to prohibit the importation and inter-provincial trade of MMT in June 1997. Ethyl Corporation of Richmond, Virginia, the sole producers of MMT, claimed discriminatory treatment under NAFTA and sought $ 250 million in damages as compensation for alleged 'expropriation' of the company's investment interests. A stunning reversal of the Canadian government's decision occurred one year later. Canada agreed to pay Ethyl Corporation $ 13 million (representing legal fees and lost profits) and agreed to rescind the legislation and admit publicly that the use of MMT poses no environmental risk. The reversal was the result of the little-known Agreement on Internal Trade (AIT), a federal-provincial government agreement, intended to reduce 'non-tariff' barriers to inter-provincial trade and create greater economic union. The AIT is modelled on NAFTA and the Uruguay-round GATT, and treats relations between the Canadian provinces as if they were relations among sovereign states. In cases of conflict, provinces are entitled to seek resolution of complaints before dispute resolution panels. Some of the provinces voiced objection to the MMT legislation and Alberta, supported by three other provinces, filed an AIT complaint against the federal government for prohibiting the inter-provincial trade of MMT. The AIT dispute panel upheld Alberta's complaint. The decision was hailed as a 'triumph of principle over bad science'. It was an unmitigated success for Ethyl Corporation, and a humiliating defeat for the federal government. In this author's view, the MMT story is a clear example of yet another instrument by which corporate power can limit the capacity of democratically elected governments to act on behalf of the public good

  10. On the pelletizing of sulfide molybdenite concentrate

    International Nuclear Information System (INIS)

    Investigation results are discussed on the process of pelletizing with the use of various binders (water, syrup, sulfite-alcoholic residue and bentonite) for flotation sulfide molybdenite concentrate (∼84 % MoS2) of the Mongolian deposit. It is established that with the use of syrup rather strong pellets (>300 g/p) of desired size (2-3 mm) can be obtained at a binder flowrate of 1 kg per 100 kg of concentrate. The main advantage of using syrup instead of bentonite lies in the fact that in this instance no depletion of a molybdenum calcine obtained by oxidizing roasting of raw ore takes place due to syrup complete burning out. This affects positively subsequent hydrometallurgical conversion because of decreasing molybdenum losses with waste cakes

  11. A novel single-precursor nanoparticle growth technique for luminescent metal sulfides (cadmium sulfide, lead sulfide, zinc sulfide) with hydrophilic surface modification

    Science.gov (United States)

    Rama, Jason Eric

    In recent years luminescent semiconductor nanoparticles (quantum dots) have attracted considerable attention, mostly due to their size-dependent tunable spectroscopic properties. Currently, fluorescing particles are put to use as biological labels alongside, or even replacing, fluorescing molecular probes. They are characterized by very narrow and tunable (excitonic) emission bands and long-range stability even under illumination. In particular, the colloidal chemistry approach to luminescent nanoparticle fabrication has been favored due to its relative ease, and high size tunability. However, the development of highly monodisperse, size tunable, and highly stable aqueous colloidal suspension fabrication methodologies has to date been very limited. In this work, the synthesis of luminescent MS (M = Cd, Pb, Zn) nanoparticles was achieved through the development and implementation of three characteristically different reaction methodologies: a spontaneous precipitation reaction (the metal chloride method), a controlled precipitation reaction (the metal oxide method), and a novel controlled aqueous decomposition reaction (the metal ethyl xanthate method) in an alkylamine solvent of 4-dimethylaminopyridine (DMAP). Varying degrees of monodispersity were achieved for the various methods, as evidenced by the photoluminescence full-width at half-maximum (FWHM). Spectral widths range from 150 nm for spontaneous precipitation methods, to as small as 20 nm for each of the temperature-controlled nucleation and ripening methods. For each of the methods, attempts at size tunability through variation of precursor concentration, growth temperature and growth time were performed. This resulted in the demonstration of an ability to fabricate size-specified semiconducting nanoparticles in the sub-10 nm size range. A demonstration of aqueous-organic-aqueous phase transfer versatility of the metal ethyl xanthate-DMAP fabrication method advances the potential of this particular method

  12. Ethyl­enediaminium hemioxalate thio­cyanate

    OpenAIRE

    Narimani, Leila; Yamin, Bohari M.

    2010-01-01

    In the title compound, C2H10N2 2+·0.5(C2O4)2−·NCS−, the ethyl­enediaminium dication adopts a (+)-synclinal conformation with an N—C—C—N torsion angle of 62.64 (15)°. The oxalate dianion lies across an inversion centre. In the crystal structure, the ions are linked through N—H⋯N, N—H⋯O and C—H⋯S hydrogen bonds, leading to the formation of a three-dimensional network.

  13. Cytotoxic constituents of ethyl acetate fraction from Dianthus superbus.

    Science.gov (United States)

    Ding, Chengli; Zhang, Wu; Li, Jie; Lei, Jiachuan; Yu, Jianqing

    2013-01-01

    The ethyl acetate fraction (EE-DS) from Dianthus superbus was found to possess the cytotoxic activity against cancer cells in previous study. To investigate cytotoxic constituents, the bioassay-guided isolation of compounds from EE-DS was performed. Two dianthramides (1 and 2), three flavonoids (3-5), two coumarins (6 and 7) and three other compounds (8-10) were obtained. Structures of isolated compounds were identified by spectroscopic analysis. Cytotoxicity of the compounds against HepG2 cells was evaluated. Compound 1 showed the strongest cytotoxicity, compounds 10, 4, 3 and 5 had moderate cytotoxicity.

  14. Effect of radiation on wettability and floatability of sulfide minerals

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The feasibility for modifying the wettability and floatability of sulfide minerals by electron beam irradiation has been studied experimentally. The wettability of crystalline pyrite and floatability of some sulfide as pyrite, arsenopyrite, chalcopyrite and marmatite after irradiation were examined by flotation in a modified Hallimond tube. Experimental results show that the hydrophobicity of crystalline pyrite enhances with the increase of irradiation dose in a low dose range. And the flotation responses of sulfide minerals on irradiation dosevary with the mineral species and particle size. The floatability of minerals can be regulated by altering irradiation dose. An explanationfor the mechanism has been suggested based on the principle of radiation chemistry.

  15. Sulfide capacities of MnO-SiO2 slags

    Science.gov (United States)

    Reddy, Ramana G.; Blander, Milton

    1989-04-01

    Sulfide capacities of binary MnO-SiO2 slags at 1773 and 1923 K were calculated thermodynamically. Only known data, such as the standard free energy of formation of MnO and MnS and activities of MnO in the melt, are used in making calculations based on fundamental concepts. Excellent agreement is found between our calculations and published experimental data. Correlations of sulfide capacities, based on optical basicity using Pauling electronegativities or empirically deduced optical basicities, differ from the experimental data in both magnitude and concentration dependence. Our method provides useful predictions of sulfide capacities a priori.

  16. Optimization of the superconducting phase of hydrogen sulfide

    Energy Technology Data Exchange (ETDEWEB)

    Degtyarenko, N. N.; Masur, E. A., E-mail: eugen-mazur@mail.ru [National Research Nuclear University MEPhI (Russian Federation)

    2015-12-15

    The electron and phonon spectra, as well as the densities of electron and phonon states of the SH{sub 3} phase and the stable orthorhombic structure of hydrogen sulfide SH{sub 2}, are calculated for the pressure interval 100–225 GPa. It is found that the I4/mmm phase can be responsible for the superconducting properties of metallic hydrogen sulfide along with the SH{sub 3} phase. Sequential stages for obtaining and conservation of the SH{sub 2} phase are proposed. The properties of two (SH{sub 2} and SH{sub 3}) superconducting phases of hydrogen sulfide are compared.

  17. Optimization of the superconducting phase of hydrogen sulfide

    International Nuclear Information System (INIS)

    The electron and phonon spectra, as well as the densities of electron and phonon states of the SH3 phase and the stable orthorhombic structure of hydrogen sulfide SH2, are calculated for the pressure interval 100–225 GPa. It is found that the I4/mmm phase can be responsible for the superconducting properties of metallic hydrogen sulfide along with the SH3 phase. Sequential stages for obtaining and conservation of the SH2 phase are proposed. The properties of two (SH2 and SH3) superconducting phases of hydrogen sulfide are compared

  18. Effect of Soluble Sulfide on the Activity of Luminescent Bacteria

    OpenAIRE

    Feng Wang; Ling-Ling Wu; Hong-Wen Gao; Ying Shao

    2012-01-01

    Sulfide is an important water pollutant widely found in industrial waste water that has attracted much attention. S2−, as a weak acidic anion, is easy hydrolyzed to HS and H2S in aqueous solution. In this study, biological tests were performed to establish the toxicity of sulfide solutions on luminescent bacteria. Considering the sulfide solution was contained three substances—S2−, HS

  19. Ethyl Pyruvate Combats Human Leukemia Cells but Spares Normal Blood Cells.

    Science.gov (United States)

    Birkenmeier, Gerd; Hemdan, Nasr Y A; Kurz, Susanne; Bigl, Marina; Pieroh, Philipp; Debebe, Tewodros; Buchold, Martin; Thieme, Rene; Wichmann, Gunnar; Dehghani, Faramarz

    2016-01-01

    Ethyl pyruvate, a known ROS scavenger and anti-inflammatory drug was found to combat leukemia cells. Tumor cell killing was achieved by concerted action of necrosis/apoptosis induction, ATP depletion, and inhibition of glycolytic and para-glycolytic enzymes. Ethyl lactate was less harmful to leukemia cells but was found to arrest cell cycle in the G0/G1 phase. Both, ethyl pyruvate and ethyl lactate were identified as new inhibitors of GSK-3β. Despite the strong effect of ethyl pyruvate on leukemia cells, human cognate blood cells were only marginally affected. The data were compiled by immune blotting, flow cytometry, enzyme activity assay and gene array analysis. Our results inform new mechanisms of ethyl pyruvate-induced cell death, offering thereby a new treatment regime with a high therapeutic window for leukemic tumors. PMID:27579985

  20. Ethyl Pyruvate Combats Human Leukemia Cells but Spares Normal Blood Cells

    Science.gov (United States)

    Kurz, Susanne; Bigl, Marina; Buchold, Martin; Thieme, Rene; Wichmann, Gunnar; Dehghani, Faramarz

    2016-01-01

    Ethyl pyruvate, a known ROS scavenger and anti-inflammatory drug was found to combat leukemia cells. Tumor cell killing was achieved by concerted action of necrosis/apoptosis induction, ATP depletion, and inhibition of glycolytic and para-glycolytic enzymes. Ethyl lactate was less harmful to leukemia cells but was found to arrest cell cycle in the G0/G1 phase. Both, ethyl pyruvate and ethyl lactate were identified as new inhibitors of GSK-3β. Despite the strong effect of ethyl pyruvate on leukemia cells, human cognate blood cells were only marginally affected. The data were compiled by immune blotting, flow cytometry, enzyme activity assay and gene array analysis. Our results inform new mechanisms of ethyl pyruvate-induced cell death, offering thereby a new treatment regime with a high therapeutic window for leukemic tumors. PMID:27579985

  1. Adsorbate thermodynamics as a determinant of reaction mechanism: Pentamethylene sulfide on Mo(110)

    Energy Technology Data Exchange (ETDEWEB)

    Wiegand, B.C.; Friend, C.M.; Roberts, J.T. (Harvard Univ., Cambridge, MA (USA))

    The reactions of the totally unstrained, six-membered cyclic sulfide pentamethylene sulfide on Mo(110) have been investigated by using temperature-programmed reaction spectroscopy and X-ray photoelectron spectroscopy in an effort to identify the roles of ring size and strain in dictating reaction selectivity. Four gases products are detected in the temperature-programmed reaction of pentamethylene sulfide: dihydrogen at 380 and 590 K, pentane at 350 K, pentene at 345 K, and pentamethylene sulfide at 190 and 280 K. The kinetics for hydrocarbon production from pentamethylene sulfide are qualitatively different than for the four- and five-membered cyclic sulfides, trimethylene sulfide and tetrahydrothiophene.

  2. Micro-aeration for hydrogen sulfide removal from biogas

    Science.gov (United States)

    Duangmanee, Thanapong

    The presence of sulfur compounds (e.g. protein, sulfate, thiosulfate, sulfite, etc.) in the feed stream generates highly corrosive and odorous hydrogen sulfide during anaerobic digestion. The high sulfide level in the biogas stream is not only poisonous to many novel metal catalysts employed in thermo-catalytic processes but also reduces the quality of methane to produce renewable energy. This study used an innovative, low-maintenance, low-cost biological sulfide removal technology to remove sulfides simultaneously from both gas and liquid phase. ORP (Oxidation-Reduction-Potential) was used as the controlling parameter to precisely regulate air injection to the sulfide oxidizing unit (SOU). The microaeration technique provided just enough oxygen to partially oxidize sulfides to elemental sulfur without inhibiting methanogenesis. The SOU was equipped with a diffuser at the bottom for the dispersion of sulfide-laden biogas and injected air throughout the column. The SOU can be operated as a standalone unit or coupled with an anaerobic digester to simultaneously remove sulfide from the biogas and effluent. The integrated system was capable of reducing hydrogen sulfide in biogas from 2,450 to less than 2 ppmV with minimal sulfate production at the highest available sulfide loading rate of 0.24 kg/m3-day. More than 98% of sulfide removed was recovered as elemental sulfur. However, the standalone SOU was able to operate at high hydrogen sulfide loading of 1.46 kg/m 3-day at inlet sulfide concentration of 3000 ppmV and reduce the off-gas hydrogen sulfide concentrations to less than 10 ppmV. The experiment also revealed that the ORP controlled aeration was sensitive enough to prevent oxygen overdosing (dampening effect) during unexpected surges of aeration. Using generalized linear regression, a model predicting output H2S concentration based on input H2S concentrations, SOU medium heights, and biogas flow rates, was derived. With 95% confidence, output H2S concentration

  3. Biological and chemical sulfide oxidation in a Beggiatoa inhabited marine sediment

    DEFF Research Database (Denmark)

    Preisler, André; de Beer, Dirk; Lichtschlag, Anna;

    2007-01-01

    The ecological niche of nitrate-storing Beggiatoa, and their contribution to the removal of sulfide were investigated in coastal sediment. With microsensors a clear suboxic zone of 2-10 cm thick was identified, where neither oxygen nor free sulfide was detectable. In this zone most of the Beggiat...... were found, where they oxidize sulfide with internally stored nitrate. The sulfide input into the suboxic zone was dominated by an upward sulfide flux from deeper sediment, whereas the local production in the suboxic zone was much smaller. Despite their abundance, the calculated sulfide......, where they oxidize sulfide with internally stored nitrate. The sulfide input into the suboxic zone was dominated by an upward sulfide flux from deeper sediment, whereas the local production in the suboxic zone was much smaller. Despite their abundance, the calculated sulfide-oxidizing capacity...

  4. Electrical transport in ethyl cellulose–chloranil system

    Indian Academy of Sciences (India)

    P K Khare; R K Pandey; P L Jain

    2000-08-01

    The charge-transport behaviour in pure and chloranil (Chl) doped ethyl cellulose (EC) system has been studied by measuring the dependence of current on field, temperature, electrode material and dopant concentration. The role of doping molecular concentration in the polymer matrix and modification in the conduction characteristics are studied. Lowering of the activation energy due to doping was observed. The current was found to increase with an increase in the chloranil concentration. An explanation for this has been attempted on the basis of formation of molecular aggregates between chloranil molecules and ethoxy groups of ethyl cellulose. It is suggested that chloranil occupies interstitial positions between the polymer chains and assists in carrier transportation by reducing the hopping barriers. The current–voltage characteristics of different samples are analyzed using space charge limited current theory and quantitative information about the transport parameters is derived. The values of effective drift mobility and trapped charge carrier concentration which result in the build up of space charge have been calculated.

  5. Discovery of Methyl Acetate and Gauche Ethyl Formate in Orion

    CERN Document Server

    Tercero, B; Cernicharo, J; Nguyen, H V L; López, A; Caro, G M Muñoz

    2013-01-01

    We report on the discovery of methyl acetate, CH3COOCH3, through the detection of a large number of rotational lines from each one of the spin states of the molecule: AA species (A1 or A2), EA species (E1), AE species (E2), EE species (E3 or E4). We also report the detection, for the first time in space, of the $gauche$ conformer of ethyl formate, CH3CH2OCOH, in the same source. The trans conformer is also detected for the first time outside the galactic center source SgrB2. From the derived velocity of the emission of methyl acetate we conclude that it arises mainly from the compact ridge region with a total column density of (4.2+-0.5)E15 cm(-2). The derived rotational temperature is 150 K. The column density for each conformer of ethyl formate, trans and gauche, is (4.5+-1.0)E14 cm(-2). Their abundance ratio indicates a kinetic temperature of 135 K for the emitting gas and suggests that gas phase reactions could participate efficiently in the formation of both conformers in addition to cold ice mantle reac...

  6. Sulfide mineralization in ultramafic rocks of the Faryab ophiolite complex, southern Kerman

    OpenAIRE

    Mohammad Ali Rajabzadeh; Fatemeh Al Sadi

    2015-01-01

    Introduction Worldwide, Ni-Cu and PGE magmatic sulfide deposits are confined to the lower parts of stratiform mafic and ultramafic complexes. However, ophiolite mafic and ultramafic complexes have been rarely explored for sulfide deposits despite the fact that they have been extensively explored and exploited for chromite. Sulfide saturation during magmatic evolution is necessary for sulfide mineralization, in which sulfide melts scavenge chalcophile metals from the parent magma and conc...

  7. [Activity of hydrogen sulfide production enzymes in kidneys of rats].

    Science.gov (United States)

    Mel'nyk, A V; Pentiuk, O O

    2009-01-01

    An experimental research of activity and kinetic descriptions of enzymes participating in formation of hydrogen sulfide in the kidney of rats has been carried out. It was established that cystein, homocystein and thiosulphate are the basic substrates for hydrogen sulfide synthesis. The higest activity for hydrogen sulfide production belongs to thiosulfate-dithiolsulfurtransferase and cysteine aminotransferase, less activity is characteristic of cystathionine beta-synthase and cystathio-nine gamma-lyase. The highest affinity to substrate is registered for thiosulfate-dithiolsulfurtransferase and cystathionine gamma-lyase. It is discovered that the substrate inhibition is typical of all hydrogen sulfide formation enzymes, although this characteristic is the most expressed thiosulfat-dithiolsulfurtransferase. PMID:20387629

  8. Optimization of biological sulfide removal in a CSTR bioreactor.

    Science.gov (United States)

    Roosta, Aliakbar; Jahanmiri, Abdolhossein; Mowla, Dariush; Niazi, Ali; Sotoodeh, Hamidreza

    2012-08-01

    In this study, biological sulfide removal from natural gas in a continuous bioreactor is investigated for estimation of the optimal operational parameters. According to the carried out reactions, sulfide can be converted to elemental sulfur, sulfate, thiosulfate, and polysulfide, of which elemental sulfur is the desired product. A mathematical model is developed and was used for investigation of the effect of various parameters on elemental sulfur selectivity. The results of the simulation show that elemental sulfur selectivity is a function of dissolved oxygen, sulfide load, pH, and concentration of bacteria. Optimal parameter values are calculated for maximum elemental sulfur selectivity by using genetic algorithm as an adaptive heuristic search. In the optimal conditions, 87.76% of sulfide loaded to the bioreactor is converted to elemental sulfur.

  9. Hydrogen Sulfide Micro-Sensor for Biomass Fouling Detection Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Hydrogen Sulfide (H2S)is the leading chemical agent causing human fatalities following inhalation exposures. The overall aim of this project is to develop and...

  10. The hydrogen sulfide metabolite trimethylsulfonium is found in human urine

    Science.gov (United States)

    Lajin, Bassam; Francesconi, Kevin A.

    2016-06-01

    Hydrogen sulfide is the third and most recently discovered gaseous signaling molecule following nitric oxide and carbon monoxide, playing important roles both in normal physiological conditions and disease progression. The trimethylsulfonium ion (TMS) can result from successive methylation reactions of hydrogen sulfide. No report exists so far about the presence or quantities of TMS in human urine. We developed a method for determining TMS in urine using liquid chromatography-electrospray ionization-triple quadrupole mass spectrometry (LC-ESI-QQQ), and applied the method to establish the urinary levels of TMS in a group of human volunteers. The measured urinary levels of TMS were in the nanomolar range, which is commensurate with the steady-state tissue concentrations of hydrogen sulfide previously reported in the literature. The developed method can be used in future studies for the quantification of urinary TMS as a potential biomarker for hydrogen sulfide body pools.

  11. Selective adsorption of bacteria on sulfide minerals surface

    Institute of Scientific and Technical Information of China (English)

    JIA Chun-yun; WEI De-zhou; LIU Wen-gang; HAN Cong; GAO Shu-ling; WANG Yu-juan

    2008-01-01

    The adsorption of bacteria on sulfide minerals surface was studied, and the selective adsorption mechanism of cells on the sulfide minerals was investigated by means of FTIR, UVS and XPS. The results show that the three strains of bacteria adsorbed more preferentially on pyrite than on other two sulfide minerals surface at neutral and alkaline pH conditions. FTIR and UVS of three strains of bacteria indicate that there are more functional groups on their surface, such as O-H, C=O, N-H, C-O, and the content of saccharide is more than that of protein. The state of every element on sulfide minerals surface was analyzed by XPS. The empty orbital number of electronic shell of metal ions on minerals surface is important in selective adsorption process, and some stable constants of metal coordinates can be used to explain the contribution of some groups in saccharide of cell wall to the selective adsorption.

  12. Conspicuous veils formed by vibrioid bacteria on sulfidic marine sediment

    DEFF Research Database (Denmark)

    Thar, Roland Matthias; Kühl, Michael

    2002-01-01

    , but the bacteria have so far not been isolated in pure culture, and a detailed characterization of their metabolism is still lacking. The bacteria are colorless, gram-negative, and vibrioid-shaped (1.3- to 2.5- by 4- to 10-µm) cells that multiply by binary division and contain several spherical inclusions of poly......We describe the morphology and behavior of a hitherto unknown bacterial species that forms conspicuous veils (typical dimensions, 30 by 30 mm) on sulfidic marine sediment. The new bacteria were enriched on complex sulfidic medium within a benthic gradient chamber in oxygen-sulfide countergradients......-ß-hydroxybutyric acid. The cells have bipolar polytrichous flagella and exhibit a unique swimming pattern, rotating and translating along their short axis. Free-swimming cells showed aerotaxis and aggregated at ca. 2 µM oxygen within opposing oxygen-sulfide gradients, where they were able to attach via a mucous stalk...

  13. The hydrogen sulfide metabolite trimethylsulfonium is found in human urine

    OpenAIRE

    Bassam Lajin; Francesconi, Kevin A

    2016-01-01

    Hydrogen sulfide is the third and most recently discovered gaseous signaling molecule following nitric oxide and carbon monoxide, playing important roles both in normal physiological conditions and disease progression. The trimethylsulfonium ion (TMS) can result from successive methylation reactions of hydrogen sulfide. No report exists so far about the presence or quantities of TMS in human urine. We developed a method for determining TMS in urine using liquid chromatography-electrospray ion...

  14. An eco-friendly oxidation of sulfide compounds

    Indian Academy of Sciences (India)

    RAVINDRA B WAGH; SITARAM H GUND; JAYASHREE M NAGARKAR

    2016-08-01

    An improved green route has been developed for the oxidation of sulfide compounds. Albendazole is converted to ricobendazole or albendazole sulfone using H₂O₂ as an oxidant and H₂O as the solvent. High yields of the corresponding products were obtained by carrying out the reaction at room temperature. This synthetic method is environmentally clean and safe, operationally simple for the oxidation of other benzimidazole anthelmintics and various sulfide compounds.

  15. INVESTIGATIONS ON BIOCHEMICAL PURIFICATION OF GROUND WATER FROM HYDROGEN SULFIDE

    Directory of Open Access Journals (Sweden)

    Yu. P. Sedlukho

    2015-01-01

    Full Text Available The paper considers problems and features of biochemical removal of hydrogen sulfide from ground water. The analysis of existing methods for purification of ground water from hydrogen sulfide has been given in the paper. The paper has established shortcomings of physical and chemical purification of ground water. While using aeration methods for removal of hydrogen sulfide formation of colloidal sulfur that gives muddiness and opalescence to water occurs due to partial chemical air oxidation. In addition to this violation of sulfide-carbonate equilibrium taking place in the process of aeration due to desorption of H2S and CO2, often leads to clogging of degasifier nozzles with formed CaCO3 that causes serious operational problems. Chemical methods require relatively large flow of complex reagent facilities, storage facilities and transportation costs.In terms of hydrogen sulfide ground water purification the greatest interest is given to the biochemical method. Factors deterring widespread application of the biochemical method is its insufficient previous investigation and necessity to execute special research in order to determine optimal process parameters while purifying groundwater of a particular water supply source. Biochemical methods for oxidation of sulfur compounds are based on natural biological processes that ensure natural sulfur cycle. S. Vinogradsky has established a two-stage mechanism for oxidation of hydrogen sulfide with sulfur bacteria (Beggiatoa. The first stage presupposes oxidation of hydrogen sulphide to elemental sulfur which is accumulating in the cytoplasm in the form of globules. During the second stage sulfur bacteria begin to oxidize intracellular sulfur to sulfuric acid due to shortage of hydrogen sulfide.The paper provides the results of technological tests of large-scale pilot plants for biochemical purification of groundwater from hydrogen sulfide in semi-industrial conditions. Dependences of water quality

  16. Mechanism for SOFC anode degradation from hydrogen sulfide exposure

    Energy Technology Data Exchange (ETDEWEB)

    Lussier, A.; Dvorak, J.; Idzerda, Y.U. [Department of Physics, Montana State University, EPS Building, Room 264, Bozeman, MT 59717 (United States); Sofie, S. [Department of Mechanical and Industrial Engineering, Montana State University, 201E Roberts Hall, Bozeman, MT 59717 (United States)

    2008-07-15

    Recent results on solid oxide fuel cells with Ni/YSZ and Ni/GDC anodes reveal a mechanism for permanent performance degradation due to hydrogen sulfide exposure. Our results confirm the temporary performance decline observed by others but also reveal a mechanism for the long term permanent degradation. We find that hydrogen sulfide leads to nickel migration and depletion in the anode, thereby compromising electrical conductivity and cell performance. (author)

  17. Sulfide oxidation in fluidized bed bioreactor using nylon support material

    Institute of Scientific and Technical Information of China (English)

    Varsha Midha; M K Jha; Apurba Dey

    2012-01-01

    A continuous fluidized bed bioreactor(FBBR)with nylon support particles was used to treat synthetic sulfide wastewater at different hydraulic retention time of 25,50 and 75 min and upflow velocity of 14,17 and 20 m/hr.The effects of upflow velocity,hydraulic retention time and reactor operation time on sulfide oxidation rate were studied using statistical model.Mixed culture obtained from the activated sludge,taken from tannery effluent treatment plant,was used as a source for microorganisms.The diameter and density of the nylon particles were 2-3 mm and 1140 kg/m3,respectively.Experiments were carried out in the reactor at a temperature of(30± 2)℃,at a fixed bed height of 16 cm after the formation of biofilm on the surface of support particles.Biofilm thickness reached(42±3)μm after 15 days from reactor start-up.The sulfide oxidation,sulfate and sulfur formation is examined at all hydraulic retention times and upflow velocities.The results indicated that almost 90%-92% sulfide oxidation was achieved at all hydraulic retention times.Statistical model could explain 94% of the variability and analysis of variance showed that upflow velocity and hydraulic retention time slightly affected the sulfide oxidation rate.The highest sulfide oxidation of 92% with 70% sulfur was obtained at hydraulic retention time of 75 min and upflow velocity of 14 m/hr.

  18. Sulfide capacity of high alumina blast furnace slags

    Science.gov (United States)

    Shankar, Amitabh; Görnerup, Märten; Seetharaman, S.; Lahiri, A. K.

    2006-12-01

    Sulfide capacities of high alumina blast furnace slags were experimentally determined using the gas-slag equilibration technique. Two different slag systems were considered for the current study, namely, CaO-SiO2-MgO-Al2O3 quaternary and CaO-SiO2-MgO-Al2O3-TiO2 quinary system. The liquid slag was equilibrated with the Ar-CO-CO2-SO2 gas mixture. Experiments were conducted in the temperature range of 1773 to 1873 K. The effects of temperature, basicity, and the MgO and TiO2 contents of slags on sulfide capacity were studied. As expected, sulfide capacity was found to increase with the increase in temperature and basicity. At the higher experimental temperature, titania decreases the sulfide capacity of slag. However, at the lower temperature, there was no significant effect of titania on the sulfide capacity of slag. Sulfide capacity increases with the increase in MgO content of slag if the MgO content is more than 5 pct.

  19. Dihydrogen Activation by Titanium Sulfide Complexes

    Science.gov (United States)

    Sweeney, Zachary K.; Polse, Jennifer L.; Bergman*, Robert G.; Andersen*, Richard A.

    2005-01-01

    The titanocene sulfido complex Cp*2Ti(S)py (1, Cp* = pentamethylcyclopentadienyl; py = pyridine) is synthesized by addition of a suspension of S8 to a toluene solution of Cp*2Ti-(CH2CH2) (2) and py. The rate of rotation of the pyridine ligand in solution was determined by 1H NMR spectroscopy, and the structure of 1 was determined by X-ray crystallography. Complex 1 reacts reversibly with dihydrogen to give Cp*2Ti(H)SH (6) and py. Reaction of 1 with HD gives an equilibrium mixture of Cp*2Ti(D)SH and Cp*2Ti(H)SD; H2 and D2 are not formed in this reaction. 1D 1H NMR magnetization transfer spectra and 2D EXSY 1H NMR spectra of 6 in the presence of H2 show that in solution the H2, hydride, and hydrosulfido hydrogen atoms exchange. A four-center mechanism for this exchange is proposed. The EXSY studies show that the Ti–H and S–H hydrogens exchange with each other more rapidly than either of those hydrogens exchanges with external H2. A transient dihydrogen complex intermediate is proposed to explain this observation. The infrared spectrum of 6 shows an absorption assigned to the Ti–H stretching mode at 1591 cm−1 that shifts upon deuteration to 1154 cm−1. Reaction of 1 with trimethylsilane, diethylsilane, or dimethylsilane gives Cp*2-Ti(H)SSiMe3 (7), Cp*2Ti(H)SSiHEt2 (8), or Cp*2Ti(H)SSiHMe2 (9), respectively. The isotope effect for the reaction producing 7 has been measured, and a mechanism is proposed. Treatment of 1 with an additional equivalent of S8 results in the formation of the disulfide Cp*2Ti(S2) (4). Acetylene inserts into the Ti–S bond of 4 to produce the vinyl disulfide complex 5. The structures of 4 and 5 have been determined by X-ray diffraction. Compound 4 reacts with 2 in the presence of py to produce 1. Phosphines react with 4 in the presence of H2 to provide 6 and the corresponding phosphine sulfide. Reaction of hydrogen with 4 gives Cp*2-Ti(SH)2 (3). The reactions of 1 and 4 with dihydrogen provide a model for possible mechanisms of H2

  20. Hydrogen Sulfide and Endothelium-Dependent Vasorelaxation

    Directory of Open Access Journals (Sweden)

    Jerzy Bełtowski

    2014-12-01

    Full Text Available In addition to nitric oxide and carbon monoxide, hydrogen sulfide (H2S, synthesized enzymatically from l-cysteine or l-homocysteine, is the third gasotransmitter in mammals. Endogenous H2S is involved in the regulation of many physiological processes, including vascular tone. Although initially it was suggested that in the vascular wall H2S is synthesized only by smooth muscle cells and relaxes them by activating ATP-sensitive potassium channels, more recent studies indicate that H2S is synthesized in endothelial cells as well. Endothelial H2S production is stimulated by many factors, including acetylcholine, shear stress, adipose tissue hormone leptin, estrogens and plant flavonoids. In some vascular preparations H2S plays a role of endothelium-derived hyperpolarizing factor by activating small and intermediate-conductance calcium-activated potassium channels. Endothelial H2S signaling is up-regulated in some pathologies, such as obesity and cerebral ischemia-reperfusion. In addition, H2S activates endothelial NO synthase and inhibits cGMP degradation by phosphodiesterase 5 thus potentiating the effect of NO-cGMP pathway. Moreover, H2S-derived polysulfides directly activate protein kinase G. Finally, H2S interacts with NO to form nitroxyl (HNO—a potent vasorelaxant. H2S appears to play an important and multidimensional role in endothelium-dependent vasorelaxation.

  1. Anisotropic Optical Properties of Layered Germanium Sulfide

    CERN Document Server

    Tan, Dezhi; Wang, Feijiu; Mohamed, Nur Baizura; Mouri, Shinichiro; Sandhaya, Koirala; Zhang, Wenjing; Miyauchi, Yuhei; Ohfuchi, Mari; Matsuda, Kazunari

    2016-01-01

    Two-dimensional (2D) layered materials, transition metal dichalcogenides and black phosphorus, have attracted much interest from the viewpoints of fundamental physics and device applications. The establishment of new functionalities in anisotropic layered 2D materials is a challenging but rewarding frontier, owing to their remarkable optical properties and prospects for new devices. Here, we report the anisotropic optical properties of layered 2D monochalcogenide of germanium sulfide (GeS). Three Raman scattering peaks corresponding to the B3g, A1g, and A2g modes with strong polarization dependence are demonstrated in the GeS flakes, which validates polarized Raman spectroscopy as an effective method for identifying the crystal orientation of anisotropic layered GeS. Photoluminescence (PL) is observed with a peak at around 1.66 eV that originates from the direct optical transition in GeS at room temperature. Moreover, determination of the polarization dependent characteristics of the PL and absorption reveals...

  2. Hydrogen Sulfide and Cellular Redox Homeostasis

    Directory of Open Access Journals (Sweden)

    Zhi-Zhong Xie

    2016-01-01

    Full Text Available Intracellular redox imbalance is mainly caused by overproduction of reactive oxygen species (ROS or weakness of the natural antioxidant defense system. It is involved in the pathophysiology of a wide array of human diseases. Hydrogen sulfide (H2S is now recognized as the third “gasotransmitters” and proved to exert a wide range of physiological and cytoprotective functions in the biological systems. Among these functions, the role of H2S in oxidative stress has been one of the main focuses over years. However, the underlying mechanisms for the antioxidant effect of H2S are still poorly comprehended. This review presents an overview of the current understanding of H2S specially focusing on the new understanding and mechanisms of the antioxidant effects of H2S based on recent reports. Both inhibition of ROS generation and stimulation of antioxidants are discussed. H2S-induced S-sulfhydration of key proteins (e.g., p66Shc and Keap1 is also one of the focuses of this review.

  3. Hydrogen Sulfide and Cellular Redox Homeostasis

    Science.gov (United States)

    Xie, Zhi-Zhong; Liu, Yang; Bian, Jin-Song

    2016-01-01

    Intracellular redox imbalance is mainly caused by overproduction of reactive oxygen species (ROS) or weakness of the natural antioxidant defense system. It is involved in the pathophysiology of a wide array of human diseases. Hydrogen sulfide (H2S) is now recognized as the third “gasotransmitters” and proved to exert a wide range of physiological and cytoprotective functions in the biological systems. Among these functions, the role of H2S in oxidative stress has been one of the main focuses over years. However, the underlying mechanisms for the antioxidant effect of H2S are still poorly comprehended. This review presents an overview of the current understanding of H2S specially focusing on the new understanding and mechanisms of the antioxidant effects of H2S based on recent reports. Both inhibition of ROS generation and stimulation of antioxidants are discussed. H2S-induced S-sulfhydration of key proteins (e.g., p66Shc and Keap1) is also one of the focuses of this review. PMID:26881033

  4. Ethyl carbamate levels in selected fermented foods and beverages.

    Science.gov (United States)

    Canas, B J; Havery, D C; Robinson, L R; Sullivan, M P; Joe, F L; Diachenko, G W

    1989-01-01

    Ethyl carbamate (EC), also known as urethane, is an animal carcinogen and a by-product of fermentation. Because EC has been found in distilled spirits and wines, a variety of fermented foods and beverages were analyzed to assess its occurrence in other products. Previously described methods using a gas chromatograph-thermal energy analyzer with a nitrogen converter were modified for each matrix and gave recoveries of greater than 80%, with a limit of detection in the 1-2 micrograms/kg (ppb) range. A total of 152 test samples were analyzed; EC levels ranged from none found to 3 ppb in 15 cheeses, 6 teas, 12 yogurts, and 8 ciders; from none found to 13 ppb in 30 breads and 69 malt beverages; and from none found to 84 ppb in 12 soy sauces. Gas chromatography/mass spectrometry/mass spectrometry was used to confirm EC identity and to quantitate EC in selected food extracts. PMID:2592308

  5. GROUP TRANSFER POLYMERIZATION OF ETHYL ACRYLATE WITH LEWIS ACID CATALYST

    Institute of Scientific and Technical Information of China (English)

    XU Linyun; Wang Lei

    1989-01-01

    This paper reports the kinetics of group transfer polymerization (GTP) of ethyl acrylate (EA) with zinc iodide catalyst in 1,2- dichloroethane using dimethyl ketene methyl trimethylsilyl acetal ( MTS ) as initiator at 0 ℃ and above 0 ℃ . The amount of catalyst used was studied. When zinc iodide catalyst used is more than 10mol% relative to monomer, the rate of polymerization is proportional to the concentration of monomer, whereas zinc iodide catalyst used is less than 10 mol% of the monomer, the rate of polymerization is independent of the monomer concentration. In the GTP of EA an induction period was observed when the zinc iodide contents are less than 10 mol%. If the reaction temperature is over 0 ℃ , living species become unstable and diminish, leading to incomplete monomer conversion. The reaction curves equations are obtained. The polymers have narrow molecular weight distributions which are not changed as decreasing zinc iodide contents. The polydispersity is about 1.2.

  6. Hydroxide as general base in the saponification of ethyl acetate.

    Science.gov (United States)

    Mata-Segreda, Julio F

    2002-03-13

    The second-order rate constant for the saponification of ethyl acetate at 30.0 degrees C in H(2)O/D(2)O mixtures of deuterium atom fraction n (a proton inventory experiment) obeys the relation k(2)(n) = 0.122 s(-1) M(-1) (1 - n + 1.2n) (1 - n + 0.48n)/(1 - n + 1.4n) (1 - n + 0.68n)(3). This result is interpreted as a process where formation of the tetrahedral intermediate is the rate-determining step and the transition-state complex is formed via nucleophilic interaction of a water molecule with general-base assistance from hydroxide ion, opposite to the direct nucleophilic collision commonly accepted. This mechanistic picture agrees with previous heavy-atom kinetic isotope effect data of Marlier on the alkaline hydrolysis of methyl formate.

  7. Synthesis and crystal structure of ethyl benzimidazole-2-yl phosphonate

    Institute of Scientific and Technical Information of China (English)

    HU, Fang-Zhong; WENG, Lin-Hong; YANG, Hua-Zheng; ZOU, Xiao-Mao

    2000-01-01

    When N-cyanoimido- ( O, O-diethyl ) phosphonyl/ S-methyl thiocarbonate (1) was treated with o-phenylenediamine in the presence of Et3N in ethanol, diethyl benzimidazole-2-yl recrys phonate(2) was obtained and hydrolyzed during the recrys tallization in MeOH/H2O, generating ethyl benzimidazole-2-yl phosphonate(3). The crystal structure of compound 3 was determined by X-ray diffraction method. The crystals belong to monoclinic, space rgoup C2/c, a=1.78408(18), b=O. 83725(9), c=1.67401(18) nm, β= 118.997(2)°, v=2. 1870(4) nm3, z=8, Dc=1.374g/cm3, F(000)=944.The final R and wR are 0.0499 and 0.1436, respectively. The mechanism of the above reaction is also discussed.

  8. Synthesis and thermolysis of oxo chloro-2-ethyl-1.3.4-thiadiazole rhenium complex

    International Nuclear Information System (INIS)

    Present article is devoted to synthesis and thermolysis of oxo chloro-2-ethyl-1.3.4-thiadiazole rhenium complex. The synthesis method of oxo chloro-2-ethyl-1.3.4-thiadiazole rhenium complex is elaborated. The kinetics of its thermolysis process is studied. The thermodynamic functions of thermolysis process are evaluated.

  9. 40 CFR 180.212 - S-Ethyl cyclohexylethylthio-carbamate; tolerances for residues.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false S-Ethyl cyclohexylethylthio-carbamate; tolerances for residues. 180.212 Section 180.212 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Tolerances § 180.212 S-Ethyl cyclohexylethylthio-carbamate; tolerances for residues. (a) General....

  10. 40 CFR 721.538 - Phenol, 4-(1,1-dimethyl- ethyl)-, homopolymer.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Phenol, 4-(1,1-dimethyl- ethyl... Specific Chemical Substances § 721.538 Phenol, 4-(1,1-dimethyl- ethyl)-, homopolymer. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as phenol,...

  11. 77 FR 75859 - Pyraflufen-Ethyl; Extension of Time-Limited Pesticide Tolerances

    Science.gov (United States)

    2012-12-26

    ... was sufficient to establish tolerances for cattle, goat, horse, and sheep meat byproducts and milk...- ethyl temporary tolerances for cattle, goat, horse and sheep meat byproducts, and milk are ``safe'' and... time-limited tolerances for residues of pyraflufen-ethyl in or on cattle, meat byproducts; goat,...

  12. Differential susceptibility of rats and guinea pigs to the ototoxic effects of ethyl benzene

    NARCIS (Netherlands)

    Cappaert, NLM; Klis, SFL; Muijser, H; Kulig, BM; Ravensberg, LC; Smoorenburg, GF

    2002-01-01

    The present study was designed to compare the ototoxic effects of volatile ethyl benzene in guinea pigs and rats. Rats showed deteriorated auditory thresholds in the mid-frequency range, based on electrocochleography, after 550-ppm ethyl benzene (8 h/day, 5 days). Outer hair cell (OHC) loss was foun

  13. Application of substituted 2-(trimethylsilyl)ethyl esters to suppress diketopiperazine formation

    NARCIS (Netherlands)

    Borsuk, K.; Delft, F.L. van; Eggen, I.F.; Kortenaar, P.B.W. ten; Petersen, A.; Rutjes, F.P.J.T.

    2004-01-01

    The use of differently substituted 2-(trimethylsilyl)ethyl esters for C-terminal protection in peptide synthesis has been investigated. While the use of the unsubstituted 2-(trimethylsilyl)ethyl ester resulted in a substantial amount of diketopiperazine at the dipeptide stage, use of the correspondi

  14. Icosapent ethyl for the treatment of severe hypertriglyceridemia

    Directory of Open Access Journals (Sweden)

    Fares H

    2014-06-01

    Full Text Available Hassan Fares,1 Carl J Lavie,2,3 James J DiNicolantonio,4 James H O'Keefe,5 Richard V Milani2 1Department of Hospital Medicine, Ochsner Medical Center, New Orleans, LA, 2Department of Cardiovascular Diseases, John Ochsner Heart and Vascular Institute, Ochsner Clinical School, University of Queensland School of Medicine, New Orleans, LA, 3Department of Preventive Medicine, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA, 4Mid America Heart Institute at Saint Luke's Hospital, Kansas City, MO, 5Mid America Heart Institute, University of Missouri–Kansas City, Kansas City, MO, USA Abstract: Hypertriglyceridemia is a highly prevalent lipid abnormality and it is associated with atherosclerosis, with a growing body of evidence linking elevated triglycerides (TGs with cardiovascular disease. The current major omega-3 polyunsaturated fatty acids, eicosapentaenoic acid (EPA/docosahexaenoic acid (DHA combination, lowers serum TGs while often increasing levels of low-density lipoprotein cholesterol. Icosapent ethyl is an omega-3 polyunsaturated fatty acid with a 96% pure ethyl ester of EPA that has been recently approved for lowering TG levels in patients with very high TGs (≥500 mg/dL, and it does so without significantly affecting serum low-density lipoprotein cholesterol. The potential benefits of omega-3 fatty acid therapy for dyslipidemias will be discussed, including the potential pros and cons of EPA alone versus the more common and readily available EPA/DHA combination therapy. Keywords: triglycerides, low-density lipoprotein, eicosapentaenoic acid, docosahexaenoic acid

  15. Biomonitoring of N-ethyl-2-pyrrolidone in automobile varnishers.

    Science.gov (United States)

    Koslitz, Stephan; Meier, Swetlana; Schindler, Birgit Karin; Weiss, Tobias; Koch, Holger Martin; Brüning, Thomas; Käfferlein, Heiko Udo

    2014-12-01

    N-alkyl-2-pyrrolidones are important organic solvents for varnishes in industry. This study investigates exposure to N-ethyl-2-pyrrolidone (NEP) in varnishing of hard plastic components in an automobile plant. Two specific biomarkers of exposure, 5-hydroxy-N-ethyl-2-pyrrolidone (5-HNEP) and 2-hydroxy-N-ethylsuccinimide (2-HESI), were analyzed in urine samples of 14 workers. For this purpose, pre-shift, post-shift and next day pre-shift urine samples were collected midweek. Twelve workers performed regular work tasks (loading, wiping and packing), whereas two workers performed special work tasks including cleaning the sprayer system with organic solvents containing N-alkyl-2-pyrrolidones. Spot urine samples of nine non-exposed persons of the same plant served as controls. Median post-shift urinary levels of workers with regular work tasks (5-HNEP: 0.15 mg/L; 2-HESI: 0.19 mg/L) were ∼5-fold higher compared to the controls (0.03 mg/L each). Continuously increasing metabolite levels, from pre-shift via post-shift to pre-shift samples of the following day, were observed in particular for the two workers with the special working tasks. Maximum levels were 31.01 mg/L (5-HNEP) and 8.45 mg/L (2-HESI). No clear trend was evident for workers with regular working tasks. In summary, we were able to show that workers can be exposed to NEP during varnishing tasks in the automobile industry.

  16. Solubility of CO2 and H2S in the ionic liquid 1-ethyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate

    International Nuclear Information System (INIS)

    Highlights: • Measurement solubility of single gases CO2 and H2S in [C2mim][eFAP] ionic liquid. • Evaluation of Henry’s constants for solubility of CO2 and H2S in [C2mim][eFAP]. • Correlation of experimental data by the Redlich–Kwong equation of State. • Correlation of experimental data by the extended Henry’s law and Pitzer model. • Comparison of [C2mim][eFAP] with other ILs for gas sweetening and separation. -- Abstract: The solubility of two single gases carbon dioxide and hydrogen sulfide in the ionic liquid 1-ethyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate ([C2mim][eFAP]) was experimentally determined at temperatures from (303 to 353) K and pressures up to about 2.0 MPa. Results show that hydrogen sulfide is more soluble in that particular ionic liquid than carbon dioxide. At fixed temperature and pressure, the amount of dissolved H2S is more than twice the amount of CO2. The new experimental data were used to determine the Henry’s law constants, which again were used to derive some thermodynamic functions of the gas/solvent systems, such as, for example, the change of the partial molar Gibbs free energy of the gases upon solution in the ionic liquid. Two models were used to correlate the new experimental data: (1) a model comprised of the extended Henry’s law and Pitzer's virial expansion for the excess Gibbs free energy, and (2) a generic Redlich–Kwong (RK) cubic equation of state recently proposed for gas-ionic liquid systems. Both models are equally suited to correlate the experimental results. The (CO2 + H2S) selectivity of [C2mim][eFAP] was calculated from the RK EoS at various temperatures, pressures and CO2/H2S feed ratios and compared with the recently reported results for the selectivity of other ionic liquids

  17. Atmospheric measurements of carbonyl sulfide, dimethyl sulfide, and carbon disulfide using the electron capture sulfur detector

    Science.gov (United States)

    Johnson, James E.; Bates, Timothy S.

    1993-01-01

    Measurements of atmospheric dimethyl sulfide (DMS), carbonyl sulfide (COS), and carbon disulfide (CS2) were conducted over the Atlantic Ocean on board the NASA Electra aircraft during the Chemical Instrumentation Test and Evaluation (CITE 3) project using the electron capture sulfur detector (ECD-S). The system employed cryogenic preconcentration of air samples, gas chromatographic separation, catalytic fluorination, and electron capture detection. Samples collected for DMS analysis were scrubbed of oxidants with NaOH impregnated glass fiber filters to preconcentration. The detection limits (DL) of the system for COS, DMS, and CS2 were 5, 5, and 2 ppt, respectively. COS concentrations ranged from 404 to 603 ppt with a mean of 489 ppt for measurements over the North Atlantic Ocean (31 deg N to 41 deg N), and from 395 to 437 ppt with a mean of 419 ppt for measurements over the Tropical Atlantic Ocean (11 deg S to 2 deg N). DMS concentrations in the lower marine boundary layer, below 600-m altitude, ranged from below DL to 150 ppt from flights over the North Atlantic, and from 9 to 104 ppt over the Tropical Atlantic. CS2 concentrations ranged from below DL to 29 ppt over the North Atlantic. Almost all CS2 measurements over the Tropical Atlantic were below DL.

  18. Distribution and organoleptic impact of ethyl 2-methylbutanoate enantiomers in wine.

    Science.gov (United States)

    Lytra, Georgia; Tempere, Sophie; de Revel, Gilles; Barbe, Jean-Christophe

    2014-06-01

    The enantiomers of ethyl 2-methylbutanoate were assayed in several wines using chiral gas chromatography (β-cyclodextrin). Analyses of 37 commercial red wines from various vintages and origins revealed the almost exclusive presence of the S-enantiomeric form. The average concentration was ∼50 μg/L, but the oldest samples were found to contain higher ethyl 2-methylbutanoate levels than the youngest wines. The olfactory threshold of a racemic mixture of ethyl (2R)-2-methylbutanoate and ethyl (2S)-2-methylbutanoate (50:50, m/m) in dilute alcohol solution was 2.60 μg/L, almost twice that of the S-form, which was 1.53 μg/L. Ethyl (2S)-2-methylbutanoate and the racemic mixture of ethyl (2R)-2-methylbutanoate and ethyl (2S)-2-methylbutanoate had different aromatic nuances: the former was mainly defined by fruity descriptors, such as green apple (Granny Smith) and strawberry, whereas the latter had an unspecific, caustic, fruity, solvent odor. Sensory analysis revealed an enhancing effect of ethyl (2S)-2-methylbutanoate on the perception of fruity aromas in the matrices studied: the "olfactory threshold" of the fruity pool, consisting of esters found in red wines, in dilute alcohol solution alone was higher than that of the same mixture supplemented with 50 μg/L ethyl (2S)-2-methylbutanoate. The sensory profiles of these aromatic reconstitutions highlighted the contribution of ethyl (2S)-2-methylbutanoate to black-berry-fruit descriptors. PMID:24844693

  19. 9-Hydroxyfurodysinin-O-ethyl Lactone: A New Sesquiterpene Isolated from the Tropical Marine Sponge Dysidea arenaria

    Directory of Open Access Journals (Sweden)

    P. Karuso

    2005-10-01

    Full Text Available A new sesquiterpene, 9-hydroxyfurodysinin-O-ethyl lactone, has been isolated from a New Caledonian Dysidea arenaria, along with three known compounds. The possible incorporation of the ethyl ether from the extraction solvent is discussed.

  20. Dimethyl sulfide in the Amazon rain forest

    Science.gov (United States)

    Jardine, K.; Yañez-Serrano, A. M.; Williams, J.; Kunert, N.; Jardine, A.; Taylor, T.; Abrell, L.; Artaxo, P.; Guenther, A.; Hewitt, C. N.; House, E.; Florentino, A. P.; Manzi, A.; Higuchi, N.; Kesselmeier, J.; Behrendt, T.; Veres, P. R.; Derstroff, B.; Fuentes, J. D.; Martin, S. T.; Andreae, M. O.

    2015-01-01

    Surface-to-atmosphere emissions of dimethyl sulfide (DMS) may impact global climate through the formation of gaseous sulfuric acid, which can yield secondary sulfate aerosols and contribute to new particle formation. While oceans are generally considered the dominant sources of DMS, a shortage of ecosystem observations prevents an accurate analysis of terrestrial DMS sources. Using mass spectrometry, we quantified ambient DMS mixing ratios within and above a primary rainforest ecosystem in the central Amazon Basin in real-time (2010-2011) and at high vertical resolution (2013-2014). Elevated but highly variable DMS mixing ratios were observed within the canopy, showing clear evidence of a net ecosystem source to the atmosphere during both day and night in both the dry and wet seasons. Periods of high DMS mixing ratios lasting up to 8 h (up to 160 parts per trillion (ppt)) often occurred within the canopy and near the surface during many evenings and nights. Daytime gradients showed mixing ratios (up to 80 ppt) peaking near the top of the canopy as well as near the ground following a rain event. The spatial and temporal distribution of DMS suggests that ambient levels and their potential climatic impacts are dominated by local soil and plant emissions. A soil source was confirmed by measurements of DMS emission fluxes from Amazon soils as a function of temperature and soil moisture. Furthermore, light- and temperature-dependent DMS emissions were measured from seven tropical tree species. Our study has important implications for understanding terrestrial DMS sources and their role in coupled land-atmosphere climate feedbacks.

  1. Hydrogen sulfide and nervous system regulation

    Institute of Scientific and Technical Information of China (English)

    ZHOU Cheng-fang; TANG Xiao-qing

    2011-01-01

    Objective This review discusses the current status and progress in studies on the roles of hydrogen sulfide (H2S) in regulation of neurotoxicity,neuroprotection,and neuromodulator,as well as its therapeutic potential for neurodegenerative disorders.Data sources The data used in this review were mainly from Medline and PubMed published in English from 2001 to August 2011.The search terms were “hydrogen sulfide”,“neuron”,and “neurodegenerative disorders”.Study selection Articles regarding the regulation of neuronal function,the protection against neuronal damage and neurological diseases,and their possible cellular and molecular mechanisms associated with H2S were selected.Results The inhibited generation of endogenous H2S is implicated in 1-methy-4-phenylpyridinium ion,6-OHDA,and homocysteine-triggered neurotoxicity.H2S elicits neuroprotection in Alzheimer's disease and Parkinson's disease models as well as protecting neurons against oxidative stress,ischemia,and hypoxia-induced neuronal death.H2S offers anti-oxidant,anti-inflammatory and anti-apoptotic effects,as well as activates ATP-sensitive potassium channels and cystic fibrosis transmembrane conductance regulator Cl- channels.H2S regulates the long-term potentiation (LTP) and GABAB receptors in the hippocampus,as well as intracellular calcium and pH homeostasis in neurons and glia cells.Conclusions These articles suggest that endogenous H2S may regulate the toxicity of neurotoxin.H2S not only acts as a neuroprotectant but also serves as a novel neuromodulator.

  2. Electrical properties of seafloor massive sulfides

    Science.gov (United States)

    Spagnoli, Giovanni; Hannington, Mark; Bairlein, Katharina; Hördt, Andreas; Jegen, Marion; Petersen, Sven; Laurila, Tea

    2016-06-01

    Seafloor massive sulfide (SMS) deposits are increasingly seen as important marine metal resources for the future. A growing number of industrialized nations are involved in the surveying and sampling of such deposits by drilling. Drill ships are expensive and their availability can be limited; seabed drill rigs are a cost-effective alternative and more suitable for obtaining cores for resource evaluation. In order to achieve the objectives of resource evaluations, details are required of the geological, mineralogical, and physical properties of the polymetallic deposits and their host rocks. Electrical properties of the deposits and their ore minerals are distinct from their unmineralized host rocks. Therefore, the use of electrical methods to detect SMS while drilling and recovering drill cores could decrease the costs and accelerate offshore operations by limiting the amount of drilling in unmineralized material. This paper presents new data regarding the electrical properties of SMS cores that can be used in that assessment. Frequency-dependent complex electrical resistivity in the frequency range between 0.002 and 100 Hz was examined in order to potentially discriminate between different types of fresh rocks, alteration and mineralization. Forty mini-cores of SMS and unmineralized host rocks were tested in the laboratory, originating from different tectonic settings such as the intermediate-spreading ridges of the Galapagos and Axial Seamount, and the Pacmanus back-arc basin. The results indicate that there is a clear potential to distinguish between mineralized and non-mineralized samples, with some evidence that even different types of mineralization can be discriminated. This could be achieved using resistivity magnitude alone with appropriate rig-mounted electrical sensors. Exploiting the frequency-dependent behavior of resistivity might amplify the differences and further improve the rock characterization.

  3. Microbial control of hydrogen sulfide production in a porous medium

    Energy Technology Data Exchange (ETDEWEB)

    McInerney, M.J.; Wofford, N.Q. [Univ. of Oklahoma, Norman, OK (United States); Sublette, K.L. [Univ. of Tulsa, OK (United States)

    1996-12-31

    The ability of a sulfide- and glutaraldehyde-tolerant strain of Thiobacillus denitrificans (strain F) to control sulfide production in an experimental system of cores and formation water from the Redfield, Iowa natural gas storage facility was investigated. A stable, sulfide-producing biofilm was established in two separate core systems, one of which was inoculated with strain F, and the other core system (control) was treated in an identical manner, but was not inoculated with strain F. When formation water with 10 mM acetate and 5mM nitrate was injected into both core systems, the effluent sulfide concentrations in the control core system ranged from 200-460 {mu}M. In the test core system inoculated with strain F, the effluent sulfide concentrations were lower, ranging from 70-110 {mu}M. In order to determine whether strain F could control sulfide production under optimal conditions for sulfate-reducing bacteria, the electron donor was changed to lactate, and inorganic nutrients (nitrogen and phosphate sources) were added to the formation water. When nutrient-supplemented formation water with 3.1 mM lactate and 10 mM nitrate was used, the effluent sulfide concentrations of the control core system initially increased to about 3800 pM, and then decreased to about 1100 {mu}M after 5 wk. However, in the test core system inoculated with strain F, the effluent sulfide concentrations were much lower, 160-330 {mu}M. Nitrate consumption (5 mM) and high concentrations (101-1011 cells/mL) of strain F were detected in the test core system. An accumulation of biomass occurred in the influent lines during 2 mo of continuous operation, but only a small increase in injection pressure was observed. These studies showed that inoculation with strain F was needed for effective control of sulfide production, and that significant plugging or loss of injectivity owing to microbial inoculation did not occur. 7 refs., 3 figs., 1 tab.

  4. Sulfide Oxidation in the Anoxic Black-Sea Chemocline

    DEFF Research Database (Denmark)

    JØRGENSEN, BB; FOSSING, H.; WIRSEN, CO;

    1991-01-01

    that the measured H2S oxidation rates were 4-fold higher than could be explained by the downward flux of organic carbon and too high to balance the availability of electron acceptors such as oxidized iron or manganese. A nitrate maximum at the lower boundary of the O2 zone did not extend down to the sulfide zone.......The depth distributions of O2 and H2S and of the activity of chemical or bacterial sulfide oxidation were studied in the chemocline of the central Black Sea. Relative to measurements from earlier studies, the sulfide zone had moved upwards by 20-50 m and was now (May 1988) situated at a depth of 81......-99 m. Oxygen in the water column immediately overlying the sulfide zone was depleted to undetectable levels resulting in a 20-30-m deep intermediate layer of O2- and H2S-free water. Radiotracer studies with S-35-labelled H2S showed that high rates of sulfide oxidation, up to a few micromoles per liter...

  5. Species-specific enzymatic tolerance of sulfide toxicity in plant roots.

    Science.gov (United States)

    Martin, Nicole M; Maricle, Brian R

    2015-03-01

    Toxic effects of sulfide come from a poisoning of a number of enzymes, especially cytochrome c oxidase, which catalyzes the terminal step in mitochondrial aerobic respiration. Despite this, some estuarine plants live in sulfide-rich sediments. We hypothesized estuarine and flooding-tolerant species might be more tolerant of sulfide compared to upland species, and this was tested by measures of root cytochrome c oxidase and alcohol dehydrogenase activities in extracts exposed to sulfide. Enzyme activities were measured in 0, 5, 10, 15, and 20 μM sodium sulfide, and compared among 17 species of plants. Activities of alcohol dehydrogenase and cytochrome c oxidase were both reduced by increasing sulfide concentration, but cytochrome c oxidase was more sensitive to sulfide compared to alcohol dehydrogenase. Activities of cytochrome c oxidase were reduced to near zero at 5-10 μM sulfide whereas alcohol dehydrogenase activities were only reduced by about 50% at 10 μM sulfide. All species were sensitive to increasing sulfide, but to different degrees. Cytochrome c oxidase in flooding-sensitive species was decreased to near zero activity at 5 μM sulfide, whereas activities in some flooding-tolerant species were still detectable until 15 μM sulfide. Cytochrome c oxidase activities in some estuarine species were low even in the absence of sulfide, perhaps an adaptation to avoid sulfide vulnerability in their native, sulfide-rich habitat. This illustrates the potent metabolic effects of sulfide, and this is the first demonstration of varying sensitivities of cytochrome c oxidase to sulfide across organisms, making these data of novel importance.

  6. Simultaneous removal of sulfide, nitrate and acetate under denitrifying sulfide removal condition: Modeling and experimental validation

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Xijun; Chen, Chuan; Wang, Aijie; Guo, Wanqian; Zhou, Xu [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China); Lee, Duu-Jong, E-mail: djlee@ntu.edu.tw [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China); Department of Chemical Engineering, National Taiwan University, Taipei 106, Taiwan (China); Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan (China); Ren, Nanqi, E-mail: rnq@hit.edu.cn [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China); Chang, Jo-Shu [Research Center for Energy Technology and Strategy, National Cheng Kung University, Tainan, Taiwan (China)

    2014-01-15

    Graphical abstract: Model evaluation applied to case study 1: (A-G) S{sup 2−}, NO{sub 3}{sup −}-N, NO{sub 2}{sup −}-N, and Ac{sup −}-C profiles under initial sulfide concentrations of 156.2 (A), 539 (B), 964 (C), 1490 (D), 342.7 (E), 718 (F), and 1140.7 (G) mg L{sup −1}. The solid line represents simulated result and scatter represents experimental result. -- Highlights: • This work developed a mathematical model for DSR process. • Kinetics of sulfur–nitrogen–carbon and interactions between denitrifiers were studied. • Kinetic parameters of the model were estimated via data fitting. • The model described kinetic behaviors of DSR processes over wide parametric range. -- Abstract: Simultaneous removal of sulfide (S{sup 2−}), nitrate (NO{sub 3}{sup −}) and acetate (Ac{sup −}) under denitrifying sulfide removal process (DSR) is a novel biological wastewater treatment process. This work developed a mathematical model to describe the kinetic behavior of sulfur–nitrogen–carbon and interactions between autotrophic denitrifiers and heterotrophic denitrifiers. The kinetic parameters of the model were estimated via data fitting considering the effects of initial S{sup 2−} concentration, S{sup 2−}/NO{sub 3}{sup −}-N ratio and Ac{sup −}-C/NO{sub 3}{sup −}-N ratio. Simulation supported that the heterotrophic denitratation step (NO{sub 3}{sup −} reduction to NO{sub 2}{sup −}) was inhibited by S{sup 2−} compared with the denitritation step (NO{sub 2}{sup −} reduction to N{sub 2}). Also, the S{sup 2−} oxidation by autotrophic denitrifiers was shown two times lower in rate with NO{sub 2}{sup −} as electron acceptor than that with NO{sub 3}{sup −} as electron acceptor. NO{sub 3}{sup −} reduction by autotrophic denitrifiers occurs 3–10 times slower when S{sup 0} participates as final electron donor compared to the S{sup 2−}-driven pathway. Model simulation on continuous-flow DSR reactor suggested that the adjustment of

  7. Mutagenicity and antimutagenicity studies of DRDE-07 and its analogs against sulfur mustard in the in vitro Ames Salmonella/microsome assay.

    Science.gov (United States)

    Vijayan, Vinod; Pathak, Uma; Meshram, Ghansham Pundilikji

    2014-10-01

    Sulfur mustard (bis(2-chloroethyl) sulfide, SM), a chemical warfare agent, is classified as a class I human carcinogen by IARC. No effective antidote against this agent is available. The synthetic aminothiol, amifostine, earlier known as WR-2721, has been extensively used as a chemical radioprotector for normal tissues in cancer radiotherapy and chemotherapy. SM is a radiomimetic agent; this prompted us to evaluate the protective efficacy of amifostine and three of its analogs, DRDE-07 [S-2(2-aminoethylamino) ethyl phenyl sulphide], DRDE-30 [S-2(2-aminoethyl amino) ethyl propyl sulphide] and DRDE-35 [S-2(2-aminoethyl amino) ethyl butyl sulphide], against sulfur mustard-induced mutagenicity in the Ames Salmonella/microsome assay. The antidotes were also evaluated for possible mutagenic activity. DRDE-07 was mutagenic in strain TA104 in the absence of S9; DRDE-30 was mutagenic in strain TA100; amifostine and DRDE-35 did not show mutagenic activity in any of the five tester strains used. SM is mutagenic in strains TA97a and TA102, with or without S9 activation. In the antimutagenicity studies, DRDE-07 and DRDE-35 showed promising antimutagenic activity against SM in the absence of S9, in comparison to amifostine. DRDE-07 and DRDE-35 are promising protective agents against SM-induced mutagenicity.

  8. Joint stress of chlorimuron-ethyl and cadmium on wheat Triticum aestivum at biochemical levels

    International Nuclear Information System (INIS)

    Biochemical responses to joint stress of chlorimuron-ethyl and cadmium (Cd) in wheat Triticum aestivum were examined. The joint action of chlorimuron-ethyl and Cd weakened the inhibition of Cd or chlorimuron-ethyl on the formation of chlorophyll. It was deduced that wheat plants had the capability to protect themselves by increasing the activity of the antioxidant enzyme peroxidase (POD) with the exposure time. The joint effect of chlorimuron-ethyl and Cd on the superoxide dismutase (SOD) activity in leaves was additive, while the joint effect on the SOD activity in roots was determined by the interaction of chlorimuron-ethyl and Cd in wheat. It was also concluded that the change of malondialdehyde (MDA) content in wheat might not be a good biomarker in the oxidative damage by chlorimuron-ethyl, while a decrease in the soluble protein content and POD activity in roots could be considered as a biomarker in the damage of wheat by chlorimuron-ethyl and Cd. - Soluble protein content and peroxidase activity in seedlings were the biomarkers indicating joint stress of chemicals

  9. Diverse sulfur metabolisms from two subterranean sulfidic spring systems.

    Science.gov (United States)

    Rossmassler, Karen; Hanson, Thomas E; Campbell, Barbara J

    2016-08-01

    In sulfidic environments, microbes oxidize reduced sulfur compounds via several pathways. We used metagenomics to investigate sulfur metabolic pathways from microbial mat communities in two subterranean sulfidic streams in Lower Kane Cave, WY, USA and from Glenwood Hot Springs, CO, USA. Both unassembled and targeted recA gene assembly analyses revealed that these streams were dominated by Epsilonproteobacteria and Gammaproteobacteria, including groups related to Sulfurovum, Sulfurospirillum, Thiothrix and an epsilonproteobacterial group with no close cultured relatives. Genes encoding sulfide:quinone oxidoreductase (SQR) were abundant at all sites, but the specific SQR type and the taxonomic affiliation of each type differed between sites. The abundance of thiosulfate oxidation pathway genes (Sox) was not consistent between sites, although overall they were less abundant than SQR genes. Furthermore, the Sox pathway appeared to be incomplete in all samples. This work reveals both variations in sulfur metabolism within and between taxonomic groups found in these systems, and the presence of novel epsilonproteobacterial groups. PMID:27324397

  10. Sulfide Catalysts Supported on Porous Aromatic Frameworks for Naphthalene Hydroprocessing

    Directory of Open Access Journals (Sweden)

    Eduard Karakhanov

    2016-08-01

    Full Text Available This paper describes the first example of using porous aromatic frameworks as supports for sulfide catalysts for the hydrogenation of aromatic hydrocarbons. The synthesis of bimetallic Ni-W and Ni-Mo sulfides was performed by in situ decomposition of [(n-Bu4N]2[Ni(MeS42] (Me = W, Mo complexes, supported on mesoporous aromatic framework with a diamond-like structure. It is shown that the highest naphthalene conversions were achieved in the case of additional sulfidation with sulfur. After the reaction, catalysts were characterized by X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy. The activity of synthesized catalysts has been studied using naphthalene as a model substrate. The materials used in this study were substantially active in hydrogenation and slightly in hydrocracking of naphthalene.

  11. Extraction of Nanosized Cobalt Sulfide from Spent Hydrocracking Catalyst

    Directory of Open Access Journals (Sweden)

    Samia A. Kosa

    2013-01-01

    Full Text Available The processes used for the extraction of metals (Co, Mo, and Al from spent hydrotreating catalysts were investigated in this study. A detailed mechanism of the metal extraction process is described. Additionally, a simulation study was performed to understand the sulfidizing mechanism. The suggested separation procedure was effective and achieved an extraction of approximately 80–90%. In addition, the sulfidization mechanism was identified. This sulfidizing process for Co was found to involve an intermediate, the structure of which was proposed. This proposed intermediate was confirmed through simulations. Moreover, the activities of the spent and the regenerated catalyst were examined in the cracking of toluene. The modification of the spent catalyst through the use of different iron oxide loadings improved the catalytic activity.

  12. Mechanism of sulfide effect on viscosity of HPAM polymer solution

    Institute of Scientific and Technical Information of China (English)

    康万利; 周阳; 王志伟; 孟令伟; 刘述忍; 白宝君

    2008-01-01

    The effect of sulfide on HPAM solution viscosity was studied using BROOKFIELD DV-II viscometer,and the interaction mechanism was discussed.The HPAM solution viscosity was investigated through fully reducing sulfide by the addition of hydrogen peroxide oxidation,and the mechanism of increasing polymer viscosity was investigated.The experimental results also show that there is a critical concentration of 15 mg/L.Below it,the loss rate of HPAM solution viscosity increases more rapidly,but becomes slowly above the critical concentration.A theoretical guidance for oilfields to prepare polymer solution using sewage-water by eliminating sulfide,and it is also importance to prepare polymer solution using sewage-water and save fresh water.

  13. Investigation of chemical suppressants for inactivation of sulfide ores

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In order to investigate the effective control method of spontaneous combustion in the mining of sulfide ore deposits, This paper presents the testing results of several selected chemicals (water glass, calcium chloride, calcium oxide, magnesium oxide and their composites) as oxidation suppressants for sulfide ores. A weight increment scaling method was used to measure suppressant performance, and this method proved to be accurate, simple and convenient. Based on a large number of experiments, the test results show that four types of chemical mixtures demonstrate a good performance in reducing the oxidation rate of seven active sulfide ore samples by up to 27% to 100% during an initial 76 d period. The mixtures of water glass mixed with calcium chloride and magnesium oxide mixed with calcium chloride can also act as fire suppressants when used with fire sprinkling systems.

  14. Laser cleaning of sulfide scale on compressor impeller blade

    Science.gov (United States)

    Tang, Q. H.; Zhou, D.; Wang, Y. L.; Liu, G. F.

    2015-11-01

    Sulfide scale on the surface of a compressor impeller blade can considerably reduce the impeller performance and its service life. To prepare for subsequent remanufacturing, such as plasma spraying, it needs to be removed completely. In the corrosion process on an FV(520)B stainless steel, sulfide scale is divided into two layers because of different outward diffusion rates of Cr, Ni and Fe. In this paper, the cleaning threshold values of the upper and inner layers and the damage threshold value of the substrate were investigated using a pulsed fiber laser. To obtain experimental evidence, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and 3D surface profilometry were employed to investigate the two kinds of sulfide layers on specimens before, during, and after laser cleaning.

  15. Thermodynamics of Complex Sulfide Inclusion Formation in Ca-Treated Al-Killed Structural Steel

    Science.gov (United States)

    Guo, Yin-tao; He, Sheng-ping; Chen, Gu-jun; Wang, Qian

    2016-05-01

    Controlling the morphology of the sulfide inclusion is of vital importance in enhancing the properties of structural steel. Long strip-shaped sulfides in hot-rolled steel can spherize when, instead of the inclusion of pure single-phase MnS, the guest is a complex sulfide, such as an oxide-sulfide duplex and a solid-solution sulfide particle. In this study, the inclusions in a commercial rolled structural steel were investigated. Spherical and elongated oxide-sulfide duplex as well as single-phase (Mn,Ca)S solid solution inclusions were observed in the steel. A thermodynamic equilibrium between the oxide and sulfide inclusions was proposed to understand the oxide-sulfide duplex inclusion formation. Based on the equilibrium solidification principle, thermodynamic discussions on inclusion precipitation during the solidification process were performed for both general and resulfurized structural steel. The predicted results of the present study agreed well with the experimental ones.

  16. Thermodynamics of Complex Sulfide Inclusion Formation in Ca-Treated Al-Killed Structural Steel

    Science.gov (United States)

    Guo, Yin-tao; He, Sheng-ping; Chen, Gu-jun; Wang, Qian

    2016-08-01

    Controlling the morphology of the sulfide inclusion is of vital importance in enhancing the properties of structural steel. Long strip-shaped sulfides in hot-rolled steel can spherize when, instead of the inclusion of pure single-phase MnS, the guest is a complex sulfide, such as an oxide-sulfide duplex and a solid-solution sulfide particle. In this study, the inclusions in a commercial rolled structural steel were investigated. Spherical and elongated oxide-sulfide duplex as well as single-phase (Mn,Ca)S solid solution inclusions were observed in the steel. A thermodynamic equilibrium between the oxide and sulfide inclusions was proposed to understand the oxide-sulfide duplex inclusion formation. Based on the equilibrium solidification principle, thermodynamic discussions on inclusion precipitation during the solidification process were performed for both general and resulfurized structural steel. The predicted results of the present study agreed well with the experimental ones.

  17. Morphology and thermal studies of zinc sulfide and cadmium sulfide nanoparticles in polyvinyl alcohol matrix

    Science.gov (United States)

    Osuntokun, Jejenija; Ajibade, Peter A.

    2016-09-01

    Zn(II) and Cd(II) metal complexes of 1-cyano-1-carboethoxyethylene-2,2-dithiolato-κS,S'-bis(N,N-dimethylthiourea-κS) have been synthesized and characterized with analytical and spectroscopic techniques. The complexes were thermolysed in hexadecylamine at 200 °C to prepare ZnS and CdS nanoparticles. The nanoparticles were characterized with scanning electron microscope (SEM), transmission electron microscope (TEM), and powder X-ray diffraction (p-XRD). TEM images showed spherically shaped nanoparticles, whose sizes are in the range 4.33-7.21 nm for ZnS and 4.95-7.7 nm CdS respectively and XRD confirmed cubic crystalline phases for the nanoparticles. The optical band gap energy evaluated from the absorption spectra are 2.88 eV (430 nm) and 2.81 eV (440 nm) for the ZnS and CdS nanoparticles respectively. The as-prepared metal sulfide nanoparticles were further incorporated into polyvinyl alcohol (PVA) to give ZnS/PVA and CdS/PVA composites. The polymer nanocomposites were studied to investigate their morphology and thermal properties relative to the pure PVA. XRD diffractions indicated that the crystalline phases of the nanoparticles and the sizes in PVA matrices remained unaltered. Infra-red spectra studies revealed interactions between the PVA and the metal sulfide nanoparticles and TGA studies show that the ZnS/PVA and CdS/PVA nanocomposites exhibit better thermal stability than the pure PVA.

  18. Application of Borehole SIP Technique to Sulfide Mineral Exploration

    Science.gov (United States)

    Kim, Changryol; Park, Mi Kyung; Park, Samgyu; Sung, Nak Hoon; Shin, Seung Wook

    2016-04-01

    In the study, SIP (Spectral Induced Polarization) well logging probe system was developed to rapidly locate the metal ore bodies with sulfide minerals in the boreholes. The newly developed SIP logging probe employed the non-polarizable electrodes, consisting of zinc chloride (ZnCl2), sodium chloride (NaCl), gypsum (CaSO4·2H2O), and water (H2O), instead of existing copper electrodes, leading to eliminating the EM coupling effect in the IP surveys as much as possible. In addition, the SIP logging system is designed to make measurements down to maximum 500 meters in depth in the boreholes. The SIP well logging was conducted to examine the applicability of the SIP probe system to the boreholes at the ore mine in Jecheon area, Korea. The boreholes used in the SIP logging are known to have penetrated the metal ore bodies with sulfide minerals from the drilling investigations. The ore mine of the study area is the scarn deposits surrounded by the limestone or lime-silicate rocks in Ordovician period. The results of the SIP well logging have shown that the borehole segments with limestone or lime-silicate rocks yielded the insignificant SIP responses while the borehole segments with sulfide minerals (e.g. pyrite) provided the significant phase shifts of the SIP responses. The borehole segments penetrating the metal ore body, so-called cupola, have shown very high response of the phase shift, due to the high contents of the sulfide mineral pyrite. The phase shifts of the SIP response could be used to estimate the grade of the ore bodies since the higher contents of the sulfide minerals, the higher magnitudes of the phase shifts in the SIP responses. It is, therefore, believed that the borehole SIP technique can be applied to investigate the metal ore bodies with sulfide minerals, and that could be used to estimate the ore grades as a supplementary tool in the future.

  19. Hydrogen evolution from water through metal sulfide reactions

    International Nuclear Information System (INIS)

    Transition metal sulfides play an important catalytic role in many chemical reactions. In this work, we have conducted a careful computational study of the structures, electronic states, and reactivity of metal sulfide cluster anions M2SX− (M = Mo and W, X = 4–6) using density functional theory. Detailed structural analysis shows that these metal sulfide anions have ground state isomers with two bridging sulfide bonds, notably different in some cases from the corresponding oxides with the same stoichiometry. The chemical reactivity of these metal sulfide anions with water has also been carried out. After a thorough search on the reactive potential energy surface, we propose several competitive, energetically favorable, reaction pathways that lead to the evolution of hydrogen. Selectivity in the initial water addition and subsequent hydrogen migration are found to be the key steps in all the proposed reaction channels. Initial adsorption of water is most favored involving a terminal metal sulfur bond in Mo2S4− isomers whereas the most preferred orientation for water addition involves a bridging metal sulfur bond in the case of W2S4− and M2S5− isomers. In all the lowest energy H2 elimination steps, the interacting hydrogen atoms involve a metal hydride and a metal hydroxide (or thiol) group. We have also observed a higher energy reaction channel where the interacting hydrogen atoms in the H2 elimination step involve a thiol (–SH) and a hydroxyl (–OH) group. For all the reaction pathways, the Mo sulfide reactions involve a higher barrier than the corresponding W analogues. We observe for both metals that reactions of M2S4− and M2S5− clusters with water to liberate H2 are exothermic and involve modest free energy barriers. However, the reaction of water with M2S6− is highly endothermic with a considerable barrier due to saturation of the local bonding environment

  20. Vegetation successfully prevents oxidization of sulfide minerals in mine tailings.

    Science.gov (United States)

    Li, Yang; Sun, Qingye; Zhan, Jing; Yang, Yang; Wang, Dan

    2016-07-15

    The oxidization of metal sulfide in tailings causes acid mine drainage. However, it remains unclear whether vegetation prevents the oxidization of metal sulfides. The oxidization characteristics and microbial indices of the tailings in the presence of various plant species were investigated to explore the effects of vegetation on the oxidization of sulfide minerals in tailings. The pH, reducing sulfur, free iron oxides (Fed), chemical oxygen consumption (COC) and biological oxygen consumption (BOC) were measured. Key iron- and sulfur-oxidizing bacteria (Acidithiobacillus spp., Leptospirillum spp. and Thiobacillus spp.) were quantified using real-time PCR. The results indicate that vegetation growing on tailings can effectively prevent the oxidization of sulfide minerals in tailings. A higher pH and reducing-sulfur content and lower Fed were observed in the 0-30 cm depth interval in the presence of vegetation compared to bare tailings (BT). The COC gradually decreased with depth in all of the soil profiles; specifically, the COC rapidly decreased in the 10-20 cm interval in the presence of vegetation but gradually decreased in the BT profiles. Imperata cylindrica (IC) and Chrysopogon zizanoides (CZ) profiles contained the highest BOC in the 10-20 cm interval. The abundance of key iron- and sulfur-oxidizing bacteria in the vegetated tailings were significantly lower than in the BT; in particular, IC was associated with the lowest iron- and sulfur-oxidizing bacterial abundance. In conclusion, vegetation successfully prevented the oxidization of sulfide minerals in the tailings, and Imperata cylindrica is the most effective in reducing the number of iron- and sulfur-oxidizing bacteria and helped to prevent the oxidization of sulfide minerals in the long term. PMID:27093236

  1. Estimation of quizalofop ethyl residues in black gram (Vigna mungo L.) by gas liquid chromatography.

    Science.gov (United States)

    Mandal, Kousik; Sahoo, Sanjay Kumar; Battu, R S; Singh, Balwinder

    2014-01-01

    Quizalofop ethyl, a phenoxy propionate herbicide is used for post emergence control of annual and perennial grass weeds in broad-leaved crops in India. The experiments were designed to study the harvest time residues of quizalofop ethyl in black gram for two seasons. At harvest time, the residues of quizalofop ethyl on black gram seed, foliage and soil were found to be below the determination limit of 0.01 mg kg(-1) following a single application of the herbicide at 50 and 100 g a.i. ha(-1) for both the periods. Application of the herbicide is quite safe from a consumer and environmental point of view.

  2. Synthesis and characterization of PEG-coated poly(ethyl cyanoacrylate) nanoparticles

    Institute of Scientific and Technical Information of China (English)

    ZHAO Jin-hua; SUN Duo-xian

    2001-01-01

    Injectable nanoparticle carrier, poly (ethylene glycol)-coated poly (ethyl cyanoacrylate) has been prepared by a simple method. At First, synthesizing PEG macromonomer of poly(ethylene glycol) monomethyl ether with acryloyl chlo ride, then graft copolymer of poly(ethyl cyanoacrylate) and poly(ethylene glycol)was yield by free radical polymerization of ethyl cyanoacrylate with PEG macromonomer in toluene solvent. Characterization of the copolymer has been per formed by FTIR, 1H-NMR and GPC analysis. Nanoparticles were easily prepared from the obtained amphiphilic copolymer.

  3. The Sulfide Capacity of Iron Oxide-Rich Slags

    Science.gov (United States)

    Motlagh, M.

    1988-03-01

    The relationship between the sulfide capacity of slags rich in iron oxide and the sulfur partition ratio between the metal and slag is strongly related to the slag's iron oxide concentration. For slags containing little or no lime, this relationship is linear for a constant concentration of iron oxide in the slag. The effect of silica on changes in the sulfide capacity of slags rich in iron oxide is similar to that of basic steel-making slags, particularly at low activity of silica in slag.

  4. Experimental constraints on gold and silver solubility in iron sulfides

    Energy Technology Data Exchange (ETDEWEB)

    Pal' yanova, Galina [Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, 3, Koptyuga, Novosibirsk, 630090 (Russian Federation); Novosibirsk State University, Russia, 2, Pirogova, Novosibirsk, 630090 (Russian Federation); Mikhlin, Yuri [Institute of Chemistry and Chemical Technology, Siberian Branch of the Russian Academy of Sciences, Akademgorodok, 50/24, Krasnoyarsk, 660036 (Russian Federation); Kokh, Konstantin, E-mail: k.a.kokh@gmail.com [Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, 3, Koptyuga, Novosibirsk, 630090 (Russian Federation); Novosibirsk State University, Russia, 2, Pirogova, Novosibirsk, 630090 (Russian Federation); Siberian Physical–Technical Institute of Tomsk State University, 1, Novosobornaya, Tomsk, 634050 (Russian Federation); Karmanov, Nick [Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, 3, Koptyuga, Novosibirsk, 630090 (Russian Federation); Seryotkin, Yurii [Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, 3, Koptyuga, Novosibirsk, 630090 (Russian Federation); Novosibirsk State University, Russia, 2, Pirogova, Novosibirsk, 630090 (Russian Federation)

    2015-11-15

    Experiments were performed to determine crystallization of Fe,S-melts (pyriti≿ and troilitic with molar ratio S/Fe ratios of 2 and 1, respectively) containing traces of gold and silver at (Ag/Au){sub wt} ratios varying from 10 to 0.1. The solid products were studied by optical microscopy, scanning electron microscopy, X-ray powder diffraction (XRD), microprobe analysis, and X-ray photoelectron spectroscopy (XPS) in order to reveal the concentration limits of “invisible” gold and silver in magmatic iron sulfides, and to determine the influence of sulfur on forms of precious metals in the Fe–S system with different Ag/Au ratios. Au–Ag phases do not form inclusions but instead concentrate on the grain boundaries in the synthetic pyrrhotite and troilite, while pyrite comprises micro- (1–5 μm) and macroinclusions of Au–Ag alloys and Au–Ag sulfides. In “pyriti≿” systems, the fineness of alloys increases from 650 to 970‰ and the composition of sulfides changes from acanthite (Ag{sub 2}S) to uytenbogaardtite (Ag{sub 3}AuS{sub 2}) and petrovskaite (AgAuS) as the Ag/Au ratio decreases. The concentrations of “invisible” precious metals revealed in troilite were 0.040 ± 0.013 wt.% Au and 0.079 ± 0.016 wt.% Ag. Measured concentrations in pyrite and pyrrhotite were <0.024 wt.% Au and <0.030 wt.% Ag. The surface layers of iron sulfides probed with XPS were enriched in the precious metals, and in silver relative to gold, especially in the systems with Fe/S = 1, probably, due to depletion of the metallic alloy surfaces with gold. Au- and Ag-bearing iron sulfides crystallized primarily from melts may be the source of redeposited phases in hydrothermal and hypergene processes. - Highlights: • The samples of Fe–S–Au–Ag system were synthesized. • Coupled solubility of gold and silver in iron sulfides was specified. • Ag–Au inclusions on surfaces of iron sulfides are likely to be enriched in silver. • Au–Ag sulfides can exist along with

  5. Non-hydrolytic Sol-gel Synthesis of Tin Sulfides

    Science.gov (United States)

    Kaur, Rajvinder

    The non-hydrolytic sol-gel (NHSG) process is an effective low temperature route well known for preparing homogeneous metal oxides. Thermodynamically as well as kinetically favored products, which cannot be prepared with the traditional solid-state routes, can be produced using NHSG. This project is focused on the exploration of NHSG synthesis of binary tin sulfides. In the past few years, metal sulfides have been the subject of significant interest. Much effort has been devoted to understand these materials because of their potential applications in electronic, optical, and superconductor devices.4 Among these materials, tin sulfides are materials of technological importance, which are being explored as semiconductors, anode materials for Li ion batteries, photoconductors, photocatalysts and absorber layer materials in photovoltaic solar cell devices. All of these applications depend upon features like homogeneity, oxidation state, high surface area and purity of the materials. These properties can be difficult to achieve by employing traditional synthetic routes, which require high temperatures due to slow diffusion, limiting the products to thermodynamically stable phases and prohibiting control over properties like particle size and surface area. A variety of low temperature methods are being explored due to the increased demand for such advanced materials. This project is focused on exploring the NHSG approach to synthesize binary tin sulfides, with the main goal of establishing conditions for the targeted synthesis of different tin sulfide polymorphs with controlled particle size. Being non-oxide materials, tin sulfides can be air sensitive, which requires special attention in handling. All reactions were carried out in absence of oxygen. This project explores the reaction of tin halides with thioethers in a dry solvent medium, leading to the formation of tin sulfides. There are a number of synthetic parameters that can be varied for the NHSG approach. A

  6. Experimental constraints on gold and silver solubility in iron sulfides

    International Nuclear Information System (INIS)

    Experiments were performed to determine crystallization of Fe,S-melts (pyriti≿ and troilitic with molar ratio S/Fe ratios of 2 and 1, respectively) containing traces of gold and silver at (Ag/Au)wt ratios varying from 10 to 0.1. The solid products were studied by optical microscopy, scanning electron microscopy, X-ray powder diffraction (XRD), microprobe analysis, and X-ray photoelectron spectroscopy (XPS) in order to reveal the concentration limits of “invisible” gold and silver in magmatic iron sulfides, and to determine the influence of sulfur on forms of precious metals in the Fe–S system with different Ag/Au ratios. Au–Ag phases do not form inclusions but instead concentrate on the grain boundaries in the synthetic pyrrhotite and troilite, while pyrite comprises micro- (1–5 μm) and macroinclusions of Au–Ag alloys and Au–Ag sulfides. In “pyriti≿” systems, the fineness of alloys increases from 650 to 970‰ and the composition of sulfides changes from acanthite (Ag2S) to uytenbogaardtite (Ag3AuS2) and petrovskaite (AgAuS) as the Ag/Au ratio decreases. The concentrations of “invisible” precious metals revealed in troilite were 0.040 ± 0.013 wt.% Au and 0.079 ± 0.016 wt.% Ag. Measured concentrations in pyrite and pyrrhotite were <0.024 wt.% Au and <0.030 wt.% Ag. The surface layers of iron sulfides probed with XPS were enriched in the precious metals, and in silver relative to gold, especially in the systems with Fe/S = 1, probably, due to depletion of the metallic alloy surfaces with gold. Au- and Ag-bearing iron sulfides crystallized primarily from melts may be the source of redeposited phases in hydrothermal and hypergene processes. - Highlights: • The samples of Fe–S–Au–Ag system were synthesized. • Coupled solubility of gold and silver in iron sulfides was specified. • Ag–Au inclusions on surfaces of iron sulfides are likely to be enriched in silver. • Au–Ag sulfides can exist along with native gold in pyrite

  7. Searching for Trans Ethyl Methyl Ether in Orion KL

    CERN Document Server

    Tercero, B; López, A; Brouillet, N; Kolesniková, L; Motiyenko, R A; Margulès, L; Alonso, J L; Guillemin, J -C

    2015-01-01

    We report on the tentative detection of $trans$ Ethyl Methyl Ether (tEME), $t-CH_3CH_2OCH_3$, through the identification of a large number of rotational lines from each one of the spin states of the molecule towards Orion KL. We also search for $gauche$-$trans$-n-propanol, $Gt-n-CH_3CH_2CH_2OH$, an isomer of tEME in the same source. We have identified lines of both species in the IRAM 30m line survey and in the ALMA Science Verification data. We have obtained ALMA maps to establish the spatial distribution of these species. Whereas tEME mainly arises from the compact ridge component of Orion, Gt-n-propanol appears at the emission peak of ethanol (south hot core). The derived column densities of these species at the location of their emission peaks are $\\leq(4.0\\pm0.8)\\times10^{15} cm^{-2}$ and $\\leq(1.0\\pm0.2)\\times10^{15} cm^{-2}$ for tEME and Gt-n-propanol, respectively. The rotational temperature is $\\sim100 K$ for both molecules. We also provide maps of $CH_3OCOH$, $CH_3CH_2OCOH$, $CH_3OCH_3$, $CH_3OH$, a...

  8. Successful topical dissolution of cholesterol gallbladder stones using ethyl propionate.

    Science.gov (United States)

    Hofmann, A F; Amelsberg, A; Esch, O; Schteingart, C D; Lyche, K; Jinich, H; Vansonnenberg, E; D'Agostino, H B

    1997-06-01

    Topical dissolution of cholesterol gallbladder stones using methyl tert-butyl ether (MTBE) is useful in symptomatic patients judged too ill for surgery. Previous studies showed that ethyl propionate (EP), a C5 ester, dissolves cholesterol gallstones rapidly in vitro, but differs from MTBE in being eliminated so rapidly by the liver that blood levels remain undetectable. Our aim was to test EP as a topical dissolution agent for cholesterol gallbladder stones. Five high-risk patients underwent topical dissolution of gallbladder stones by EP. In three patients, the solvent was instilled via a cholecystostomy tube placed previously to treat acute cholecystitis; in two patients, a percutaneous transhepatic catheter was placed in the gallbladder electively. Gallstone dissolution was assessed by chromatography, by gravimetry, and by catheter cholecystography. Total dissolution of gallstones was obtained in four patients after 6-10 hr of lavage; in the fifth patient, partial gallstone dissolution facilitated basketing of the stones. In two patients, cholesterol dissolution was measured and averaged 30 mg/min. Side effects were limited to one episode of transient hypotension and pain at the infusion site; no patient developed somnolence or nausea. Gallstone elimination was associated with relief of symptoms. EP is an acceptable alternative to MTBE for topical dissolution of cholesterol gallbladder stones in high-risk patients. The lower volatility and rapid hepatic extraction of EP suggest that it may be preferable to MTBE in this investigational procedure.

  9. BAND-LIKE TEXTURE OF ETHYL-CYANOETHYL CELLULOSE MESOPHASE

    Institute of Scientific and Technical Information of China (English)

    HUANG Yong

    1991-01-01

    In the ethyl-cyanoethylcellulose ((E-CE)C)/dichloroacetic acid ( DCA ) cholesteric liquid crystalline solution, the band-like texture is formed when the mesophase aggregates with the disk-like texture grow to big enough and merge with each other with increasing concentration. The band-like texture is composed of parallel equidistant bright and dark alternative strips which are about 0.2-2.0 μm in width. In the band-like texture, the layers of ordered polymer chains are perpendicular to the solution film and the axes of helicoids are parallel to it. The width of the strips is different in different zones. Under the effect of an external magnetic field, the strips in the band-like texture first become wider and then narrower gradually. Moreover, the axes of helicoids in the (E-CE) C/DCA mesomorphic solution change from the direction normal to the magnetic field to the agreement with the magnetic field direction.

  10. Organomontmorillonites Modified with 2-Methacryloyloxy Ethyl Alkyl Dimethyl Ammonium Bromide

    Institute of Scientific and Technical Information of China (English)

    WANG Jian-quan; WU Wen-hui

    2007-01-01

    Organomontmorillonites (organo-MMT) were synthesized by means of montmorillonites (MMT) modified with a series of 2-methacryloyloxy ethyl alkyl dimethyl ammonium bromide (MAAB) having different alkyl chain lengths as cationic surfactants through a cationic exchanging reaction, and were characterized by FTIR, TG, elemental analysis, and XRD. The microenvironment of the organic interlayer such as the orientation and arrangement of the alkyl chains of MAAB, as well as the properties of nanocomposite hydrogels, were also investigated. The amount of organic components absorbed on interlayer and the basal spacing of organo-MMT both increase with the increasing of alkyl length of MAAB. When carbon number of alkyl chain is in the region of 8 to 14, the alkyl chains between layers would adopt a disordered gauche conformation; while the carbon number is 16, an ordered all-trans conformation with a vertical orientation would be found together with the disordered gauche conformation according to the results of XRD and FTIR. Due to the difference of microenvironment of organic interlayer, the Young's moduli of the nanocomposite hydrogels increased as the alkyl chains of MAAB became longer.

  11. Membrane Separation of 2-Ethyl Hexyl Amine/1-Decene

    KAUST Repository

    Bawareth, Bander

    2012-12-01

    1-Decene is a valuable product in linear alpha olefins plants that is contaminated with 2-EHA (2-ethyl hexyl amine). Using organic solvent nanofiltration membranes for this separation is quite challengeable. A membrane has to be a chemically stable in this environment with reasonable and stable separation factor. This paper shows that Teflon AF 2400 and cellulose acetate produced interesting results in 1-decene/2-EHA separation. The separation factor of Teflon AF 2400 is 3 with a stable permeance of 1.1x10-2 L/(m2·h·bar). Likewise, cellulose acetate gave 2-EHA/1-decene separation factor of 2 with a lower permeance of 3.67x10-3 L/(m2·h·bar). A series of hydrophilic membranes were tested but they did not give any separation due to high degree of swelling of 2-EHA with these polymers. The large swelling causes the membrane to lose its diffusivity selectivity because of an increase in the polymer\\'s chain mobility.

  12. Ethyl cyanide on Titan: Spectroscopic detection and mapping using ALMA

    CERN Document Server

    Cordiner, M A; Nixon, C A; Irwin, P G J; Teanby, N A; Charnley, S B; Mumma, M J; Kisiel, Z; Serigano, J; Kuan, Y -J; Chuang, Y -L; Wang, K -S

    2014-01-01

    We report the first spectroscopic detection of ethyl cyanide (C$_2$H$_5$CN) in Titan's atmosphere, obtained using spectrally and spatially resolved observations of multiple emission lines with the Atacama Large Millimeter/submillimeter array (ALMA). The presence of C$_2$H$_5$CN in Titan's ionosphere was previously inferred from Cassini ion mass spectrometry measurements of C$_2$H$_5$CNH$^+$. Here we report the detection of 27 rotational lines from C$_2$H$_5$CN (in 19 separate emission features detected at $>3\\sigma$ confidence), in the frequency range 222-241 GHz. Simultaneous detections of multiple emission lines from HC$_3$N, CH$_3$CN and CH$_3$CCH were also obtained. In contrast to HC$_3$N, CH$_3$CN and CH$_3$CCH, which peak in Titan's northern (spring) hemisphere, the emission from C$_2$H$_5$CN is found to be concentrated in the southern (autumn) hemisphere, suggesting a distinctly different chemistry for this species, consistent with a relatively short chemical lifetime for C$_2$H$_5$CN. Radiative transf...

  13. Dithiocarbamate Complexes as Single Source Precursors to Metal Sulfide Nanoparticles for Applications in Catalysis

    OpenAIRE

    Roffey, A. R.

    2014-01-01

    Herein we report the solvothermal decomposition of a range of metal dithiocarbamate complexes for the synthesis of metal sulfide nanoparticles. Metal sulfides exist in a variety of structural phases, some of which are known to be catalytically active towards various processes. The aim of this work was to synthesise a variety of different metal sulfide phases for future catalysis testing, particularly the iron sulfide greigite (Fe3S4, a thiospinel containing Fe2+ and Fe3+) which is to be teste...

  14. Combined use of fatty acid ethyl esters and ethyl glucuronide in hair for diagnosis of alcohol abuse: interpretation and advantages.

    Science.gov (United States)

    Pragst, F; Rothe, M; Moench, B; Hastedt, M; Herre, S; Simmert, D

    2010-03-20

    In this study the combined use of fatty acid ethyl esters (FAEE) and ethyl glucuronide (EtG) for diagnoses of chronically excessive alcohol abuse is investigated at 174 hair samples from driving ability examination, workplace testing and child custody cases for family courts and evaluated with respect to the basics of interpretation. Using the cut-off values of 0.50 ng/mg for FAEE and 25 pg/mg for EtG, both markers were in agreement in 75% of the cases with 103 negative and 28 positive results and there were 30 cases with FAEE positive and EtG negative and 13 cases with FAEE negative and EtG positive. As the theoretical basis of interpretation, the pharmacokinetics of FAEE and EtG is reviewed for all steps between drinking of ethanol to incorporation in hair with particular attention to relationships between alcohol dose and concentrations in hair. It is shown that the concentrations of both markers are essentially determined by the area under the ethanol concentration in blood vs. time curve AUC(EtOH), despite large inter-individual variations. It is demonstrated by calculation of AUC(EtOH) on monthly basis for moderate, risky and heavy drinking that AUC(EtOH) increases very strongly in the range between 60 and 120 g ethanol per day. This specific feature which is caused by the zero-order elimination of ethanol is a favorable prerequisite for a high discrimination power of the hair testing for alcohol abuse. From the consideration of the different profiles of FAEE and EtG along the hair and in agreement with the literature survey, a standardized hair segment 0-3 cm is proposed with cut-off values of 0.5 ng/mg for FAEE and 30 pg/mg for EtG. This improves also the agreement between FAEE and EtG results in the cases of the present study. A scheme for combined interpretation of FAEE and EtG is proposed which uses the levels of abstinence and the double of the cut-off values as criteria in addition to the cut-off's. Considering the large variations in the relationship

  15. Ethyl sulphate and ethyl glucuronide in vitreous humor as postmortem evidence marker for ethanol consumption prior to death.

    Science.gov (United States)

    Thierauf, Annette; Kempf, Jürgen; Perdekamp, Markus Grosse; Auwärter, Volker; Gnann, Heike; Wohlfarth, Ariane; Weinmann, Wolfgang

    2011-07-15

    To clarify the circumstances of death, the degree of inebriation is of importance in many cases, but for several reasons the determination of the ethanol concentration in post-mortem samples can be challenging and the synopsis of ethanol and the direct consumption markers ethyl glucuronide (EtG) and ethyl sulphate (EtS) has proved to be useful. The use of a rather stable matrix like vitreous humor offers further advantages. The aim of this study was to determine the concentrations of ethanol and the biomarkers in the robust matrix of vitreous humor and to compare them with the respective levels in peripheral venous blood and urine. Samples of urine, blood from the femoral vein and vitreous humor were taken from 26 deceased with suspected ethanol consumption prior to death and analyzed for ethanol, EtS and EtG. In the urine samples creatinine was also determined. The personal data, the circumstances of death, the post-mortem interval and the information about ethanol consumption prior to death were recorded. EtG and EtS analysis in urine was performed by LC-ESI-MS/MS, creatinine concentration was determined using the Jaffé reaction and ethanol was detected by HS-GC-FID and by an ADH-based method. In general, the highest concentrations of the analytes were found in urine and showed statistical significance. The mean concentrations of EtG were 62.8mg/L (EtG100 206.5mg/L) in urine, 4.3mg/L in blood and 2.1mg/L in vitreous humor. EtS was found in the following mean concentrations: 54.6mg/L in urine (EtS100 123.1mg/L), 1.8mg/L in blood and 0.9mg/L in vitreous humor. Ethanol was detected in more vitreous humor samples (mean concentration 2.0g/kg) than in blood and urine (mean concentration 1.6g/kg and 2.1g/kg respectively). There was no correlation between the ethanol and the marker concentrations and no statistical conclusions could be drawn between the markers and matrices.

  16. Identifying the Prospective Area of Sulfide Groundwater within the Area of Palvantash Oil and Gas Deposit

    Directory of Open Access Journals (Sweden)

    M. R. Zhurayev

    2014-03-01

    Full Text Available This paper describes the methodology of prospecting for sulfide groundwater in the area of Palvantash oil fields. In result of study allowed determining the favorable conditions for the sulfide waters formation, and mapping the areas of different sulfide water concentration. The relatively permeable areas were established and the water borehole positions were recommended.

  17. 76 FR 64022 - Hydrogen Sulfide; Community Right-to-Know Toxic Chemical Release Reporting

    Science.gov (United States)

    2011-10-17

    ... rule (December 1, 1993, 58 FR 63500). Hydrogen sulfide was listed under the criteria of EPCRA section... EPCRA section 313(d)(2)(B) (see 59 FR 61432, 61433, 61440-61442). Hydrogen sulfide has also been... adding hydrogen sulfide to the EPCRA section 313 list of toxic chemicals (58 FR 63500) (effective...

  18. Selective precipitation of heavy metals as controlled by a sulfide-selective electrode

    NARCIS (Netherlands)

    Veeken, A.H.M.; Vries, S.; Mark, van der A.

    2003-01-01

    Sulfide precipitation is superior to hydroxide precipitation for removal of heavy metals from wastewaters as it results in lower effluent concentrations and less interference from chelating agents. However, sulfide precipitation is not widely applied in practice because the dosing of sulfide cannot

  19. Sulfide-iron interactions in domestic wastewater from a gravity sewer

    NARCIS (Netherlands)

    Nielsen, A.H.; Lens, P.N.L.; Vollertsen, J.; Hvitved-Jacobsen, Th.

    2005-01-01

    Interactions between iron and sulfide in domestic wastewater from a gravity sewer were investigated with particular emphasis on redox cycling of iron and iron sulfide formation. The concentration ranges of iron and total sulfide in the experiments were 0.4-5.4 mg Fe L-1 and 0-5.1 mg S L-1, respectiv

  20. SULFIDE OXIDATION UNDER OXYGEN LIMITATION BY A THIOBACILLUS-THIOPARUS ISOLATED FROM A MARINE MICROBIAL MAT

    NARCIS (Netherlands)

    VANDENENDE, FP; VANGEMERDEN, H

    1993-01-01

    The colorless sulfur bacterium Thiobacillus thioparus T5, isolated from a marine microbial mat, was grown in continuous culture under conditions ranging from sulfide limitation to oxygen limitation. Under sulfide-limiting conditions, sulfide was virtually completely oxidized to sulfate. Under oxygen

  1. Thermochemical hydrogen production via a cycle using barium and sulfur - Reaction between barium sulfide and water

    Science.gov (United States)

    Ota, K.; Conger, W. L.

    1977-01-01

    The reaction between barium sulfide and water, a reaction found in several sulfur based thermochemical cycles, was investigated kinetically at 653-866 C. Gaseous products were hydrogen and hydrogen sulfide. The rate determining step for hydrogen formation was a surface reaction between barium sulfide and water. An expression was derived for the rate of hydrogen formation.

  2. H2S exposure elicits differential expression of candidate genes in fish adapted to sulfidic and non-sulfidic environments.

    Science.gov (United States)

    Tobler, Michael; Henpita, Chathurika; Bassett, Brandon; Kelley, Joanna L; Shaw, Jennifer H

    2014-09-01

    Disentangling the effects of plasticity, genetic variation, and their interactions on organismal responses to environmental stressors is a key objective in ecological physiology. We quantified the expression of five candidate genes in response to hydrogen sulfide (H2S) exposure in fish (Poecilia mexicana, Poeciliidae) from a naturally sulfide-rich environment as well as an ancestral, non-sulfidic population to test for constitutive and environmentally dependent population differences in gene expression patterns. Common garden raised individuals that had never encountered environmental H2S during their lifetime were subjected to short or long term H2S exposure treatments or respective non-sulfidic controls. The expression of genes involved in responses to H2S toxicity (cytochrome c oxidase, vascular endothelial growth factor, and cytochrome P450-2J6), H2S detoxification (sulfide:quinone oxidoreductase), and endogenous H2S production (cystathionine γ lyase) was determined in both gill and liver tissues by real time PCR. The results indicated complex changes in expression patterns that--depending on the gene--not only differed between organs and populations, but also on the type of H2S exposure. Populations differences, both constitutive and H2S exposure dependent (i.e., plastic), in gene expression were particularly evident for sulfide:quinone oxidoreductase, vascular endothelial growth factor, and to a lesser degree for cytochrome P450-2J6. Our study uncovered putatively adaptive modifications in gene regulation that parallel previously documented adaptive changes in phenotypic traits. PMID:24813672

  3. The structure of Aquifex aeolicus sulfide:quinone oxidoreductase, a basis to understand sulfide detoxification and respiration

    OpenAIRE

    Marcia, Marco; Ermler, Ulrich; Peng, Guohong; Michel, Hartmut

    2009-01-01

    Sulfide:quinone oxidoreductase (SQR) is a flavoprotein with homologues in all domains of life except plants. It plays a physiological role both in sulfide detoxification and in energy transduction. We isolated the protein from native membranes of the hyperthermophilic bacterium Aquifex aeolicus, and we determined its X-ray structure in the “as-purified,” substrate-bound, and inhibitor-bound forms at resolutions of 2.3, 2.0, and 2.9 Å, respectively. The structure is composed of 2 Rossmann doma...

  4. Isolation and Characterization Compounds From Hexane and Ethyl Acetate Fractions of Peperomia pellucida L.

    Directory of Open Access Journals (Sweden)

    Sri Hartati

    2015-09-01

    Full Text Available Peperomia pellucida was used traditionally in Indonesia for health treatment: wounds, boils, pimples, abscesses, abdominal pain, colic, gout, kidney, rheumatic pain, fatigue headache, furuncles, conjunctivitis and anti dermatogenic and also for dengue treatment. The isolation compounds from hexane and ethyl acetate fractions of Peperomia pellucida L. are conducted by maceration of the dry herbs sample with methanol and partition with hexane, ethyl acetate, butanol and water. The hexane and ethyl acetate fractions were fractionated by gravitation column chromatography and eluted successively with hexane, ethyl acetate and methanol by the gradient. The structure was elucidated base on spectroscopy data of NMR proton and carbon for one and two dimension, LCMS and FT-IR. The isolation founded three compounds are stigmasterol, analogue of pheophytin and β-sitosterol-D-glucopyranoside.

  5. Uses and benefits of omega-3 ethyl esters in patients with cardiovascular disease

    Directory of Open Access Journals (Sweden)

    Giacomo Levantesi

    2010-07-01

    Full Text Available Giacomo Levantesi, Maria Giuseppina Silletta, Roberto MarchioliLaboratory of Clinical Epidemiology of Cardiovascular Disease, Consorzio Mario Negri Sud, Chieti, ItalyAbstract: Much evidence on the favorable effects of omega-3 ethyl esters on cardiovascular morbidity and mortality has been obtained in studies performed in healthy subjects and in different clinical settings. Here the clinical effects of omega-3 ethyl ester administration in patients with previous myocardial infarction or heart failure are reviewed, together with a discussion of underlying mechanisms of action. The pharmacokinetic and pharmacodynamic properties of omega-3 ethyl esters, as well as evidence concerning their safety and tolerability, are also reported.Keywords: omega-3 ethyl esters, myocardial infarction, heart failure

  6. Synthesis and Anti-influenza Virus Activity of Ethyl 6-Bromo-5-hydroxyindole-3-carboxylate Derivatives

    Institute of Scientific and Technical Information of China (English)

    Yan Fang ZHAO; Jin Hua DONG; Ping GONG

    2004-01-01

    A series of ethyl 6-bromo-5-hydroxyindole-3-carboxylate derivatives were synthesized and their in vitro anti-influenza virus activity was evaluated. All the compounds were characterized by 1H NMR and MS.

  7. New HPLC method to determine ethyl carbamate in alcoholic beverages using fluorescence detection

    OpenAIRE

    Herbert, P; Santos, L.; Bastos, M.; Barros, P.; Alves, A.

    2002-01-01

    A new methodology to the quantification of ethyl carbamate (EC) has been developed. This method allows the analysis by HPLC of ethyl carbarnate in samples of wine, fortified wine, and wine brandy, by a precolumn derivatization with 9-xanthydrol, and fluorescence detection. This does not require previous sample extraction or concentration. The method presents an average recovery of 96% among samples studied, a detection limit of 4.2 mug/L, and an average intermediate precision of 6.3%. The com...

  8. Determination of Bioactive Components of Ethyl Acetate Fraction of Punica granatum Rind Extract

    OpenAIRE

    J. Sangeetha; Vijayalakshmi, K.

    2011-01-01

    Punica granatum belongs to a Punicaceae family. The Punica granatum is valued as a powerful medicinal plant and used in folk medicines. Hence the present investigation was carried out to determine the possible chemical components from ethyl acetate fraction of Punica granatum rind extract by GC-MS Technique. This analysis revealed that ethyl acetate fraction of Punica granatum rind extract contain Pyrogallol (41.88%), 5-Hydroxymethylfurfural (14.10%), D-Allose (9.17%), 2-Methoxy-1, 4-Benzened...

  9. N-[(9-Ethyl-9H-carbazol-3-ylmethylene]-3,4-dimethylisoxazol-5-amine

    Directory of Open Access Journals (Sweden)

    Abdullah Mohamed Asiri

    2010-05-01

    Full Text Available The title compound, N-[(9-ethyl-9H-carbazol-3-ylmethylene]-3,4-dimethylisoxazol-5-amine has been synthesized by reaction of 9-ethyl-9H-carbazole-3-carbaldehyde with 5-amino-3,4-dimethylisoxazole in the presence of acetic acid in ethanol. The structure of this new compound was confirmed by elemental analysis, IR, 1H-NMR, 13C-NMR and EI-MS spectral analysis.

  10. Measurement and Correlation of Solubility of Ethyl Nitrite in Mixed Solvent

    Institute of Scientific and Technical Information of China (English)

    庞建媛; 刘国维; 马沛生; 方越

    2000-01-01

    An experimental apparatus was used to measure the solubility of ethyl nitrite in mixed solvents under the lower pressure and higher temperature. The solubilities of ethyl nitrite in mixed solvents of ethanol-water at 15℃-40℃ and ethanol-diethyl oxalate at 20℃--40℃ were determined. A Henry constant model has been improved, and the interaction parameters have been fitted from experimental data. The calculation results have been compared with experimental data; the results obtained are satisfactory.

  11. COMPLEX REACTIONS OF ETHYL-GLUCOSIDES SYNTHESIS OVER ION EXCHANGE RESIN

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    IntroductionEthyl-glucoside was a tasty component of sakeand mirin, which was effective in deodorizing badsmell from fish and animal meats ['], softening saltytaste and improving all-around taste for food cooking.Sake has been used as cosmetic for skin treatment fora long time in Japan. Ethyl-glucoside, a typicalingredient in the sake, can reduce the hUrt of exposureto ultraviolat [z]. In addition, alkylglucoside was a newclass of nonionic suthetant, which was oftenapplicable in cosmetics, food emulsifier a...

  12. Catalyst-free ethyl biodiesel production from rice bran under subcritical condition

    Science.gov (United States)

    Zullaikah, Siti; Afifudin, Riza; Amalia, Rizky

    2015-12-01

    In-situ ethyl biodiesel production from rice bran under subcritical water and ethanol with no catalyst was employed. This process is environmentally friendly and is very flexible in term of feedstock utilization since it can handle relatively high moisture and free fatty acids (FFAs) contents. In addition, the alcohol, i.e. bioethanol, is a non-toxic, biodegradable, and green raw material when produced from non-edible biomass residues, leading to a 100% renewable biodiesel. The fatty acid ethyl esters (FAEEs, ethyl biodiesel) are better than fatty acid methyl esters (FAMEs, methyl biodiesel) in terms of fuel properties, including cetane number, oxidation stability and cold flow properties. The influences of the operating variables such as reaction time (1 - 10 h), ethanol concentration (12.5 - 87.5%), and pressurizing gas (N2 and CO2) on the ethyl biodiesel yield and purity have been investigated systematically while the temperature and pressure were kept constant at 200 °C and 40 bar. The optimum results were obtained at 5 h reaction time and 75% ethanol concentration using CO2 as compressing gas. Ethyl biodiesel yield and purity of 58.78% and 61.35%, respectively, were obtained using rice bran with initial FFAs content of 37.64%. FFAs level was reduced to 14.22% with crude ethyl biodiesel recovery of 95.98%. Increasing the reaction time up to 10 h only increased the yield and purity by only about 3%. Under N2 atmosphere and at the same operating conditions (5h and 75% ethanol), ethyl biodiesel yield and purity decreased to 54.63% and 58.07%, respectively, while FFAs level was increased to 17.93% and crude ethyl biodiesel recovery decreased to 87.32%.

  13. Hydrogen sulfide : role in vascular physiology and pathology

    NARCIS (Netherlands)

    Holwerda, Kim M.; Karumanchi, S. Ananth; Lely, A. Titia

    2015-01-01

    Purpose of reviewHydrogen sulfide (H2S), a colorless gas that is endogenously generated in mammals from cysteine, has important biological functions. Within the vasculature it regulates vessel tone and outgrowth of new vessels. This review summarizes recent literature on H2S signaling in the vascula

  14. Alloy selection for sulfidation: oxidation resistance in coal gasification environments

    Energy Technology Data Exchange (ETDEWEB)

    Bradshaw, R.W.; Stoltz, R.E.

    1980-01-01

    A series of iron-nickel-chromium and nickel-chromium alloys were studied for their combined sulfidation-oxidation resistance in simulated coal gasification environments. All alloys contained a minimum of 20 w/o chromium, and titanium and aluminum in the range 0 to 4 w/o. Corrosion resistance was evaluated at 1255/sup 0/K (1800/sup 0/F) in both high BTU and low BTU coal gasification atmospheres with 1 v/o H/sub 2/S. Titanium at levels greater than 1 w/o imparted significant sulfidation resistance due to an adherent, solid solution chromium-titanium oxide layer which prevented sulfur penetration. Aluminum was less effective in preventing sulfidation since surface scales were not adherent. Of the commercial alloys tested, Nimomic 81, Pyromet 31, IN801, and IN825 exhibited the best overall corrosion resistance. However, futher alloy development, tailored to produce solid solution chromium-titanium oxide scales, may lead to alloys with greater sulfidation-oxidation resistance than those investigated here.

  15. Adsorption characteristics of thiobacillus ferrooxidans on surface of sulfide minerals

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-she; XIE Xue-hui; LI Bang-mei; DONG Qing-hai

    2005-01-01

    By using thiobacillus ferrooxidans (T.f) from Qixiashan, Hubei Province, China, the adsorption characteristics of T.f on surface of sulfide mineral were studied. The influences of adsorption time, pH value, temperature, initial inoculated concentration of bacteria, concentration of sulfide mineral powder, and variety of minerals on the adsorption characteristics were firstly investigated by using the ninhydrin colorimetric method, and the changes of contact angles and Zeta potentials of mineral surface during the bacterial adsorption were then determined. The results show that when the leaching experiments are performed for a long time from several days to a month, the maximal quantity of adsorption of T.f on the surface of pyrite is obtained under the following conditions: leaching for 20 d, pH value in range of 1-2 and temperature at 30 ℃, respectively; when the bio-leaching experiments are performed for a shorter leaching time, the maximal quantity of adsorption is obtained under the conditions: bio-leaching for 2 h, at 2.4×10 7 cell/mL of initial inoculated bacteria concentration, and at 10% of mineral powder concentration; and the adsorption quantities are different form one sulfide mineral to another, and the adsorption of T.f on the surface of sulfide minerals includes three phases: increasing phase, stationary phase and decreasing phase.

  16. Luminescence in Sulfides: A Rich History and a Bright Future

    Directory of Open Access Journals (Sweden)

    Philippe F. Smet

    2010-04-01

    Full Text Available Sulfide-based luminescent materials have attracted a lot of attention for a wide range of photo-, cathodo- and electroluminescent applications. Upon doping with Ce3+ and Eu2+, the luminescence can be varied over the entire visible region by appropriately choosing the composition of the sulfide host. Main application areas are flat panel displays based on thin film electroluminescence, field emission displays and ZnS-based powder electroluminescence for backlights. For these applications, special attention is given to BaAl2S4:Eu, ZnS:Mn and ZnS:Cu. Recently, sulfide materials have regained interest due to their ability (in contrast to oxide materials to provide a broad band, Eu2+-based red emission for use as a color conversion material in white-light emitting diodes (LEDs. The potential application of rare-earth doped binary alkaline-earth sulfides, like CaS and SrS, thiogallates, thioaluminates and thiosilicates as conversion phosphors is discussed. Finally, this review concludes with the size-dependent luminescence in intrinsic colloidal quantum dots like PbS and CdS, and with the luminescence in doped nanoparticles.

  17. A coumarin-based colorimetric fluorescent probe for hydrogen sulfide

    Indian Academy of Sciences (India)

    Yanqiu Yang; Yu Liu; Liang Yang; Jun Liu; Kun Li; Shunzhong Luo

    2015-03-01

    A coumarin-based fluorescent probe for selective detection of hydrogen sulfide (H2S) is presented. This `off–on’ probe exhibited high selectivity towards H2S in aqueous solution with a detection limit of 30 nM. Notably, because of its dual nucleophilicity, the probe could avoid the interference of thiols and other sulfur containing compounds.

  18. Estimation of bacterial hydrogen sulfide production in vitro

    Directory of Open Access Journals (Sweden)

    Amina Basic

    2015-06-01

    Full Text Available Oral bacterial hydrogen sulfide (H2S production was estimated comparing two different colorimetric methods in microtiter plate format. High H2S production was seen for Fusobacterium spp., Treponema denticola, and Prevotella tannerae, associated with periodontal disease. The production differed between the methods indicating that H2S production may follow different pathways.

  19. Synthesis and photovoltaic application of coper (I) sulfide nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yue; Wadia, Cyrus; Ma, Wanli; Sadtler, Bryce; Alivisatos, A.Paul

    2008-06-24

    We present the rational synthesis of colloidal copper(I) sulfide nanocrystals and demonstrate their application as an active light absorbing component in combination with CdS nanorods to make a solution-processed solar cell with 1.6percent power conversion efficiency on both conventional glass substrates and flexible plastic substrates with stability over a 4 month testing period.

  20. Electrogenerative leaching of nickel sulfide concentrate with ferric chloride

    Institute of Scientific and Technical Information of China (English)

    王少芬; 方正; 王云燕; 陈阳国

    2004-01-01

    In order to utilize the chemical energy in hydrometallurgical process of sulfide minerals reasonably and to simplify the purifying process, the electrogenerative process was applied and a dual cell system was introduced to investigate FeCl3 leaching of nickel sulfide concentrate. Some factors influencing the electrogenerative leaching, such as electrode structure, temperature and solution concentration were studied. The results show that a certain quantity of electrical energy accompanied with the leached products can be acquired in the electrogenerative leaching process.The output current and power increase with the addition of acetylene black to the electrode. Varying the components of electrode just affects the polarization degree of anode. Increasing FeCl3 concentration results in a sharp increase in the output of the leaching cell when c(FeCl3) is less than 0.1 mol/L. The optimum value of NaCl concentration for electrogenerative leaching nickel sulfide concentrate with FeCl3 is 3.0 mol/L. Temperature influences electrogenerative leaching by affecting anodic and cathodic polarization simultaneously. The apparent activation energy is determined to be 34.63 kJ/mol in the range of 298 K to 322 K. The leaching rate of Ni2+ is 29.3% after FeCl3 electrogenerative leaching of nickel sulfide concentrate for 620 min with a filter bag electrode.

  1. Microbial Oxidation of Iron Sulfides in Anaerobic Environments

    DEFF Research Database (Denmark)

    Vaclavkova, Sarka

    Abstract (shortened): Iron sulfides (FeSx), representing 0.04-10 % of Danish dry soil weight, oxidize in a presence of oxygen, releasing sulfuric acid and free iron. Environmental impact of FeSx oxidation is commonly seen on agricultural sites cultivated by drainage as acid sulfate soil formation...

  2. Selective Sulfidation of Lead Smelter Slag with Sulfur

    Science.gov (United States)

    Han, Junwei; Liu, Wei; Wang, Dawei; Jiao, Fen; Qin, Wenqing

    2016-02-01

    The selective sulfidation of lead smelter slag with sulfur was studied. The effects of temperature, sulfur dosage, carbon, and Na salts additions were investigated based on thermodynamic calculation. The results indicated that more than 96 pct of zinc in the slag could be converted into sulfides. Increasing temperature, sulfur dosage, or Na salts dosage was conducive to the sulfidation of the zinc oxides in the slag. High temperature and excess Na salts would result in the more consumption of carbon and sulfur. Carbon addition not only promoted the selective sulfidation but reduced the sulfur dosage and eliminated the generation of SO2. Iron oxides had a buffering role on the sulfur efficient utilization. The transformation of sphalerite to wurtzite was feasible under reducing condition at high temperature, especially above 1273 K (1000 °C). The growth of ZnS particles largely depended upon the roasting temperature. They were significantly increased when the temperature was above 1273 K (1000 °C), which was attributed to the formation of a liquid phase.

  3. Magmatic sulfides in the porphyritic chondrules of EH enstatite chondrites

    CERN Document Server

    Piani, Laurette; Libourel, Guy; Tissandier, Laurent

    2016-01-01

    The nature and distribution of sulfides within 17 porphyritic chondrules of the Sahara 97096 EH3 enstatite chondrite have been studied by backscattered electron microscopy and electron microprobe in order to investigate the role of gas-melt interactions in the chondrule sulfide formation. Troilite (FeS) is systematically present and is the most abundant sulfide within the EH3 chondrite chondrules. It is found either poikilitically enclosed in low-Ca pyroxenes or scattered within the glassy mesostasis. Oldhamite (CaS) and niningerite [(Mg,Fe,Mn)S] are present in about 60% of the chondrules studied. While oldhamite is preferentially present in the mesostasis, niningerite associated with silica is generally observed in contact with troilite and low-Ca pyroxene. The chondrule mesostases contain high abundances of alkali and volatile elements as well as silica. Our data suggest that most of the sulfides found in EH3 chondrite chondrules are magmatic minerals that formed after the dissolution of S from a volatile-r...

  4. Adsorption of hydrogen sulfide on montmorillonites modified with iron.

    Science.gov (United States)

    Nguyen-Thanh, Danh; Block, Karin; Bandosz, Teresa J

    2005-04-01

    Sodium-rich montmorillonite was modified with iron in order to introduce active centers for hydrogen sulfide adsorption. In the first modification, interlayer sodium cations were exchanged with iron. In another modification, iron oxocations were introduced to the clay surface. The most elaborated modification was based on doping of iron within the interlayer space of aluminum-pillared clay. The modified clay samples were tested as hydrogen sulfide adsorbents. Iron-doped samples showed a significant improvement in the capacity for H2S removal, despite of a noticeable decrease in microporosity compared to the initial pillared clay. The smallest capacity was obtained for the clay modified with iron oxocations. Variations in adsorption capacity are likely due to differences in the chemistry of iron species, degree of their dispersion on the surface, and accessibility of small pores for H2S molecule. The results suggest that on the surface of iron-modified clay hydrogen sulfide reacts with Fe(+3) forming sulfides or it is catalytically oxidized to SO2 on iron (hydro)oxides. Subsequent oxidation may lead to sulfate formation.

  5. Solar thermal extraction of copper and zinc from sulfides

    Energy Technology Data Exchange (ETDEWEB)

    Guesdon, C.; Sturzenegger, M.

    2002-03-01

    A novel approach for extracting metals from metal sulfides is proposed. Key feature is the use of concentrated solar radiation to directly convert metal sulfides into the metal and sulfur. Such processes have the potential to produce metals with virtually zero emission of SO{sub 2} and CO{sub 2}. The feasibility of such a solar thermal extraction has been evaluated for zinc sulfide (Zn S) and copper(I)sulfide Cu{sub 2}S. Thermodynamic calculations suggest that for both processes heat recovery from the hot product is required to implement a viable process. Decomposition experiments have indicated that the high reactivity of Zn and S is not compatible with the energy requirement of heat recovery and that quenching will likely be needed to collect Zn. As an alternative, the addition of a mixture of O{sub 2} and steam (chemical quenching) is discussed. The extraction of Cu from Cu{sub 2}S appears less critical: Experiments under N{sub 2} revealed the formation of metallic Cu already at 1323 K. Natural separation of gaseous S from liquid Cu successfully prevents recombination of the two products and at least partial heat recovery can be envisaged. (author)

  6. ISE Analysis of Hydrogen Sulfide in Cigarette Smoke

    Science.gov (United States)

    Li, Guofeng; Polk, Brian J.; Meazell, Liz A.; Hatchett, David W.

    2000-08-01

    Many advanced undergraduate analytical laboratory courses focus on exposing students to various modern instruments. However, students rarely have the opportunity to construct their own analytical tools for solving practical problems. We designed an experiment in which students are required to build their own analytical module, a potentiometric device composed of a Ag/AgCl reference electrode, a Ag/Ag2S ion selective electrode (ISE), and a pH meter used as voltmeter, to determine the amount of hydrogen sulfide in cigarette smoke. Very simple techniques were developed for constructing these electrodes. Cigarette smoke is collected by a gas washing bottle into a 0.1 M NaOH solution. The amount of sulfide in the cigarette smoke solution is analyzed by standard addition of sulfide solution while monitoring the response of the Ag/Ag2S ISE. The collected data are further evaluated using the Gran plot technique to determine the concentration of sulfide in the cigarette smoke solution. The experiment has been successfully incorporated into the lab course Instrumental Analysis at Georgia Institute of Technology. Students enjoy the idea of constructing an analytical tool themselves and applying their classroom knowledge to solve real-life problems. And while learning electrochemistry they also get a chance to visualize the health hazard imposed by cigarette smoking.

  7. Micelle Mediated Trace Level Sulfide Quantification through Cloud Point Extraction

    Directory of Open Access Journals (Sweden)

    Samrat Devaramani

    2012-01-01

    Full Text Available A simple cloud point extraction protocol has been proposed for the quantification of sulfide at trace level. The method is based on the reduction of iron (III to iron (II by the sulfide and the subsequent complexation of metal ion with nitroso-R salt in alkaline medium. The resulting green-colored complex was extracted through cloud point formation using cationic surfactant, that is, cetylpyridinium chloride, and the obtained surfactant phase was homogenized by ethanol before its absorbance measurement at 710 nm. The reaction variables like metal ion, ligand, surfactant concentration, and medium pH on the cloud point extraction of the metal-ligand complex have been optimized. The interference effect of the common anions and cations was studied. The proposed method has been successfully applied to quantify the trace level sulfide in the leachate samples of the landfill and water samples from bore wells and ponds. The validity of the proposed method has been studied by spiking the samples with known quantities of sulfide as well as comparing with the results obtained by the standard method.

  8. Sulfide Formation And Its Impacts On A Developing Country

    DEFF Research Database (Denmark)

    Matias, Natércia; Mutuvúie, Raúl; Vollertsen, Jes;

    2014-01-01

    is expected in the near future, with the associated longer wastewater travel times and increasing problems of septicity and hydrogen sulfide gas impacts. In order to better understand the in-sewer processes under local conditions, evaluate risks and exemplify how to support general drainage systems planning...

  9. Potential Applications of Hydrogen Sulfide-Induced Suspended Animation

    NARCIS (Netherlands)

    H. Aslami; M.J. Schultz; N.P. Juffermans

    2009-01-01

    A suspended animation-like state has been induced in rodents with the use of hydrogen sulfide, resulting in hypothermia with a concomitant reduction in metabolic rate. Also oxygen demand was reduced, thereby protecting against hypoxia. Several therapeutic applications of induction of a hibernation-l

  10. Hydrogen sulfide : physiological properties and therapeutic potential in ischaemia

    NARCIS (Netherlands)

    Bos, Eelke M.; van Goor, Harry; Joles, Jaap A.; Whiteman, Matthew; Leuvenink, Henri G. D.

    2015-01-01

    Hydrogen sulfide (H2S) has become a molecule of high interest in recent years, and it is now recognized as the third gasotransmitter in addition to nitric oxide and carbon monoxide. In this review, we discuss the recent literature on the physiology of endogenous and exogenous H2S, focusing upon the

  11. Hydrogen sulfide release from dairy manure storages containing gypsum bedding

    Science.gov (United States)

    Recycled gypsum products can provide a cost-effective bedding alternative for dairy producers. Manufacturers report reduced odors, moisture and bacteria in the stall environment when compared to traditional bedding. Gypsum provides a sulfate source that can be converted to hydrogen sulfide under ana...

  12. 40 CFR 425.04 - Applicability of sulfide pretreatment standards.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Applicability of sulfide pretreatment standards. 425.04 Section 425.04 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS LEATHER TANNING AND FINISHING POINT SOURCE CATEGORY General Provisions § 425.04 Applicability of...

  13. Carbonyl Sulfides as Possible Intermediates in the Photolysis of Oxathiiranes

    DEFF Research Database (Denmark)

    Carlsen, Lars; Snyder, J. P.; Holm, A.;

    1981-01-01

    species and several dipolarophiles is rationlized in terms of a labile carbonyl suffide intermediate capable of facile sulfur extrusion from a long, weak O-S bond. Finally, the electronic absorption spectra of a series of para-substituted benzaldehyde O-sulfide model system have been calculated with CNDO...

  14. ETHYL CYANIDE ON TITAN: SPECTROSCOPIC DETECTION AND MAPPING USING ALMA

    Energy Technology Data Exchange (ETDEWEB)

    Cordiner, M. A.; Palmer, M. Y.; Nixon, C. A.; Charnley, S. B.; Mumma, M. J.; Serigano, J. [NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20771 (United States); Irwin, P. G. J. [Atmospheric, Oceanic and Planetary Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford, OX1 3PU (United Kingdom); Teanby, N. A. [School of Earth Sciences, University of Bristol, Wills Memorial Building, Queen’s Road, Bristol, BS8 1RJ (United Kingdom); Kisiel, Z. [Institute of Physics, Polish Academy of Sciences, Al. Lotnikøw 32/46, 02-668 Warszawa (Poland); Kuan, Y.-J.; Chuang, Y.-L. [National Taiwan Normal University, Taipei 116, Taiwan (China); Wang, K.-S., E-mail: martin.cordiner@nasa.gov [Institute of Astronomy and Astrophysics, Academia Sinica, Taipei 106, Taiwan (China)

    2015-02-10

    We report the first spectroscopic detection of ethyl cyanide (C{sub 2}H{sub 5}CN) in Titan’s atmosphere, obtained using spectrally and spatially resolved observations of multiple emission lines with the Atacama Large Millimeter/submillimeter Array (ALMA). The presence of C{sub 2}H{sub 5}CN in Titan’s ionosphere was previously inferred from Cassini ion mass spectrometry measurements of C{sub 2}H{sub 5}CNH{sup +}. Here we report the detection of 27 rotational lines from C{sub 2}H{sub 5}CN (in 19 separate emission features detected at >3σ confidence) in the frequency range 222–241 GHz. Simultaneous detections of multiple emission lines from HC{sub 3}N, CH{sub 3}CN, and CH{sub 3}CCH were also obtained. In contrast to HC{sub 3}N, CH{sub 3}CN, and CH{sub 3}CCH, which peak in Titan’s northern (spring) hemisphere, the emission from C{sub 2}H{sub 5}CN is found to be concentrated in the southern (autumn) hemisphere, suggesting a distinctly different chemistry for this species, consistent with a relatively short chemical lifetime for C{sub 2}H{sub 5}CN. Radiative transfer models show that C{sub 2}H{sub 5}CN is most concentrated at altitudes ≳200 km, suggesting production predominantly in the stratosphere and above. Vertical column densities are found to be in the range (1–5) × 10{sup 14} cm{sup −2}.

  15. Topical ethyl chloride fine spray. Does it have any antimicrobial activity?

    Energy Technology Data Exchange (ETDEWEB)

    Burney, K.; Bowker, K.; Reynolds, R.; Bradley, M

    2006-12-15

    Aim: The aim of this study was to assess whether ethyl chloride fine spray (Cryogesic[reg]) has antimicrobial activity. Material and methods: Blood agar plates supplemented with 5% horse blood were inoculated with five different organisms, coagulase-negative staphylococci (CNS), methicillin-sensitive Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), Streptococcus pyogenes and Enterococcus faecalis. The plates were assessed for growth inhibition at 24 and 48 h by the microbiologist and compared with the non-sprayed control plates. Results: The model showed a highly significant (p < 0.0001) reduction in bacterial count for the plates treated with fine ethyl chloride spray. The estimate of the percentage of bacteria remaining after spraying with ethyl chloride was 42.7%, with a 95% confidence interval of 35.9-50.9%. There was no evidence that the effect of ethyl chloride fine spray was different for the different organisms (p = 0.49). Conclusion: The use of ethyl chloride shows bacterial count reduction but the clinical implication of this needs to be determined. The authors postulate that any statistically significant reduction can only be helpful in reducing the infection rates. This coupled with the already proven local anaesthetic effects of ethyl chloride will make it an important tool for procedures like arthrocentesis and venepunctures.

  16. Topical ethyl chloride fine spray. Does it have any antimicrobial activity?

    International Nuclear Information System (INIS)

    Aim: The aim of this study was to assess whether ethyl chloride fine spray (Cryogesic[reg]) has antimicrobial activity. Material and methods: Blood agar plates supplemented with 5% horse blood were inoculated with five different organisms, coagulase-negative staphylococci (CNS), methicillin-sensitive Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), Streptococcus pyogenes and Enterococcus faecalis. The plates were assessed for growth inhibition at 24 and 48 h by the microbiologist and compared with the non-sprayed control plates. Results: The model showed a highly significant (p < 0.0001) reduction in bacterial count for the plates treated with fine ethyl chloride spray. The estimate of the percentage of bacteria remaining after spraying with ethyl chloride was 42.7%, with a 95% confidence interval of 35.9-50.9%. There was no evidence that the effect of ethyl chloride fine spray was different for the different organisms (p = 0.49). Conclusion: The use of ethyl chloride shows bacterial count reduction but the clinical implication of this needs to be determined. The authors postulate that any statistically significant reduction can only be helpful in reducing the infection rates. This coupled with the already proven local anaesthetic effects of ethyl chloride will make it an important tool for procedures like arthrocentesis and venepunctures

  17. Volcanogenic massive sulfide occurrence model: Chapter C in Mineral deposit models for resource assessment

    Science.gov (United States)

    Shanks, W.C. Pat; Koski, Randolph A.; Mosier, Dan L.; Schulz, Klaus J.; Morgan, Lisa A.; Slack, John F.; Ridley, W. Ian; Dusel-Bacon, Cynthia; Seal, Robert R., II; Piatak, Nadine M.; Shanks, W.C. Pat; Thurston, Roland

    2012-01-01

    Volcanogenic massive sulfide deposits, also known as volcanic-hosted massive sulfide, volcanic-associated massive sulfide, or seafloor massive sulfide deposits, are important sources of copper, zinc, lead, gold, and silver (Cu, Zn, Pb, Au, and Ag). These deposits form at or near the seafloor where circulating hydrothermal fluids driven by magmatic heat are quenched through mixing with bottom waters or porewaters in near-seafloor lithologies. Massive sulfide lenses vary widely in shape and size and may be podlike or sheetlike. They are generally stratiform and may occur as multiple lenses.

  18. Direct rapid determination of traces of sulfide in environment samples

    Institute of Scientific and Technical Information of China (English)

    郭方遒; 黄兰芳; 梁逸曾

    2002-01-01

    An improved ethylene blue method for determination of sulfide is developed. It has been adapted to a direct determination of sulfide by both common spectrophotometric method and total differential spectrophotometric method. In common spectrophotometric method, the calibration curve is A=1.69ρ+0.006 and the correlation coefficient is 0.9994.The apparent molar absorptivity is 5.42×104 L*mol-1*cm-1 and calibration curve is liner when ρ is in the range of 0-0.9 mg*L-1. In total differential spectrophotometric method, the calibration curve is A=9.25ρ+0.004 and the correlation coefficient is 0.9996. The apparent molar absorptivity is 2.96×105 L*mol-1*cm-1and calibration curve is liner when ρ is in the range of 0-0.10 mg*L-1. The sensitivity of this method is increased significantly compared with the former ethylene blue method. The speed of reaction is also faster than the former one. The limit of detection is found to be 1.0 ng*mL-1 by both common spectrophotometric method and total differential spectrophotometric method. Ten replicate analyses of a sample solution containing 100 ng*mL-1sulfide give a relative standard deviation of 1.8%. The effects of various cations and anions on the determination of sulfide are studied and procedures for removal of interference is described. The method is used for the determination of sulfide in environment samples with satisfactory results.

  19. Biogeographic Congruency among Bacterial Communities from Terrestrial Sulfidic Springs

    Directory of Open Access Journals (Sweden)

    Brendan eHeadd

    2014-09-01

    Full Text Available Terrestrial sulfidic springs support diverse microbial communities by serving as stable conduits for geochemically diverse and nutrient-rich subsurface waters. Microorganisms that colonize terrestrial springs likely originate from groundwater, but may also be sourced from the surface. As such, the biogeographic distribution of microbial communities inhabiting sulfidic springs should be controlled by a combination of spring geochemistry and surface and subsurface transport mechanisms, and not necessarily geographic proximity to other springs. We examined the bacterial diversity of seven springs to test the hypothesis that occurrence of taxonomically similar microbes, important to the sulfur cycle, at each spring is controlled by geochemistry. Complementary Sanger sequencing and 454 pyrosequencing of 16S rRNA genes retrieved five proteobacterial classes, and Bacteroidetes, Chlorobi, Chloroflexi, and Firmicutes phyla from all springs, which suggested the potential for a core sulfidic spring microbiome. Among the putative sulfide-oxidizing groups (Epsilonproteobacteria and Gammaproteobacteria, up to 83% of the sequences from geochemically similar springs clustered together. Abundant populations of Hydrogenimonas-like or Sulfurovum-like spp. (Epsilonproteobacteria occurred with abundant Thiothrix and Thiofaba spp. (Gammaproteobacteria, but Arcobacter-like and Sulfurimonas spp. (Epsilonproteobacteria occurred with less abundant gammaproteobacterial populations. These distribution patterns confirmed that geochemistry rather than biogeography regulates bacterial dominance at each spring. Potential biogeographic controls were related to paleogeologic sedimentation patterns that could control long-term microbial transport mechanisms that link surface and subsurface environments. Knowing the composition of a core sulfidic spring microbial community could provide a way to monitor diversity changes if a system is threatened by anthropogenic processes or

  20. Direct electrochemistry and electrocatalysis of horseradish peroxidase with hyaluronic acid-ionic liquid-cadmium sulfide nanorod composite material

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Zhihong [Institute of Nano-Science and Technology Center, Huazhong Normal University, Wuhan 430079 (China); Li Xia; Wang Yan [College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Zeng Yan [Institute of Nano-Science and Technology Center, Huazhong Normal University, Wuhan 430079 (China); Sun Wei, E-mail: sunwei@qust.edu.cn [College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Huang Xintang [Institute of Nano-Science and Technology Center, Huazhong Normal University, Wuhan 430079 (China)

    2010-06-18

    A new composite material consisted of hyaluronic acid (HA), ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF{sub 4}) and cadmium sulfide (CdS) nanorod was fabricated and used for the immobilization of horseradish peroxidase (HRP) on the surface of a carbon ionic liquid electrode (CILE), which was prepared with 1-ethyl-3-methyl-imidazolium ethylsulphate ([EMIM]EtOSO{sub 3}) as modifier. Spectroscopic results indicated that HRP remained its native structure in the composite film. Based on the synergistic effect of the materials used, an obvious promotion to the direct electron transfer efficient between HRP and CILE was achieved with a pair of well-defined redox peaks appeared in 0.1 mol L{sup -1} phosphate buffer solution, indicating the realization of the direct electrochemistry of HRP. The immobilized HRP showed good electrocatalytic activity towards the reduction of trichloroacetic acid and H{sub 2}O{sub 2} with the electrochemical parameters calculated. Based on the fabricated electrode, a new third-generation electrochemical biosensor was constructed with good stability and reproducibility.

  1. Pyrite formation and mineral transformation pathways upon sulfidation of ferric hydroxides depend on mineral type and sulfide concentration

    NARCIS (Netherlands)

    Peiffer, Stefan; Behrends, Thilo; Hellige, Katrin; Larese-Casanova, Philip; Wan, Moli; Pollok, Kilian

    2015-01-01

    The reaction of ferric (hydr)oxides with dissolved sulfide does not lead to the instantaneous production of thermodynamically stable products but can induce a variety of mineral transformations including the formation of metastable intermediates. The importance of the various transformation pathways

  2. Blood Components Prevent Sulfide Poisoning of Respiration of the Hydrothermal Vent Tube Worm Riftia pachyptila

    Science.gov (United States)

    Powell, Mar A.; Somero, George N.

    1983-01-01

    Respiration of plume tissue of the hydrothermal vent tube worm Riftia pachyptila is insensitive to sulfide poisoning in contrast to tissues of animals that do not inhabit vents. Permeability barriers may not be responsible for this insensitivity since plume homogenates are also resistant to sulfide poisoning. Cytochrome c oxidase of plume, however, is strongly inhibited by sulfide at concentrations less than 10 μ M. Factors present in blood, but not in cytosol, prevent sulfide from inhibiting cytochrome c oxidase. Avoidance of sulfide poisoning of respiration in Riftia pachyptila thus appears to involve a blood-borne factor having a higher sulfide affinity than that of cytochrome c oxidase, with the result that appreciable amounts of free sulfide are prevented from accumulating in the blood and entering the intracellular compartment.

  3. Galvanic coupling and its effect on origin potential flotation system of sulfide minerals

    Institute of Scientific and Technical Information of China (English)

    顾帼华; 戴晶平; 王晖; 邱冠周

    2004-01-01

    The galvanic coupling formed in origin potential flotation systems of sulfide minerals can be divided into three types: sulfide mineral-sulfide mineral-water system; sulfide mineral-steel ball-water system; and sulfide mineral-sulfide mineral-collector system. In this paper, taking lead, zinc, iron sulfide mineral systems for examples,several models of galvanic coupling were proposed and the effects of galvanic coupling on flotation were discussed. A galvanic contact between galena (or sphalerite) and pyrite contributes to decreasing the content of zinc in lead concentrate, and enhances remarkably the absorption of collector on the galena surface. During grinding, due to galvanic interactions between minerals and steel medium, Fe(OH)3 formed covers on the cathodic mineral surface, affecting its floatability.

  4. Simulation of sulfide buildup in wastewater and atmosphere of sewer networks.

    Science.gov (United States)

    Nielsen, A H; Yongsiri, C; Hvitved-Jacobsen, T; Vollertsen, J

    2005-01-01

    A model concept for prediction of sulfide buildup in sewer networks is presented. The model concept is an extension to--and a further development of--the WATS model (Wastewater Aerobic-anaerobic Transformations in Sewers), which has been developed by Hvitved-Jacobsen and co-workers at Aalborg University. In addition to the sulfur cycle, the WATS model simulates changes in dissolved oxygen and carbon fractions of different biodegradability. The sulfur cycle was introduced via six processes: 1. sulfide production taking place in the biofilm covering the permanently wetted sewer walls; 2. biological sulfide oxidation in the permanently wetted biofilm; 3. chemical and biological sulfide oxidation in the water phase; 4. sulfide precipitation with metals present in the wastewater; 5. emission of hydrogen sulfide to the sewer atmosphere and 6. adsorption and oxidation of hydrogen sulfide on the moist sewer walls where concrete corrosion may take place.

  5. Development of a novel antimicrobial film based on chitosan with LAE (ethyl-N(α)-dodecanoyl-l-arginate) and its application to fresh chicken.

    Science.gov (United States)

    Higueras, Laura; López-Carballo, Gracia; Hernández-Muñoz, Pilar; Gavara, Rafael; Rollini, Manuela

    2013-08-01

    Chitosan (CS) films incorporating the antimicrobial compound ethyl-N(α)-dodecanoyl-l-arginate (LAE) were developed for food packaging applications. Cast chitosan films were made with 1, 5 or 10% LAE and 20% glycerol in the film forming solution. Optical properties, release of LAE and antimicrobial activity of developed films was determined. The minimum inhibitory concentration (MIC) and the minimum biocide concentration (MBC) of LAE were determined. CS films with LAE were transparent and uniform, without discontinuities or visible particles and no visual differences could be perceived between CS and CS-LAE films. When in contact with an aqueous food simulant, the agent was fully released following a Fickian behavior in a few hours at 4 and 28°C. Antimicrobial activity of films against mesophiles, psychrophiles, Pseudomonas spp., colifoms, lactic acid bacteria, hydrogen sulfide-producing bacteria, yeast and fungi, was evaluated at two, six and eight days for its application on chicken breast fillets. Films were active against bacteria, yeasts and fungi in liquid and solid media. CS films evidenced antimicrobial activity in the range 0.47-2.96 log reductions, while CS-5%LAE film produced 1.78-5.81 log reduction. Results highlighted that LAE incorporation in a chitosan-based packaging structure may provide a relevant antimicrobial activity that could improve the stability of fresh poultry products.

  6. Conversion kinetics for smelt anions: cyanate and sulfide

    Energy Technology Data Exchange (ETDEWEB)

    DeMartini, N.

    2004-07-01

    Cyanate and sulfide are two anions found in the molten salts (smelt) from the kraft recovery boiler of the chemical recovery cycle. Their concentrations in smelt are significantly different, as are their origins. The concentration of cyanate in smelt ranges between 0.4 and 2.1 g OCN{sup -}/kg smelt while the concentration of sulfide ranges between 78 and 115 g S{sup 2-}/kg smelt. Cyanate is a by-product of black liquor combustion. It is formed from organic nitrogen compounds in black liquor during the char burning stage. The charge of the cyanate anion is balanced by the alkali metals found in smelt, namely sodium and potassium. It has been found that the nitrogen in cyanate represents about 30% of the nitrogen entering the recovery boiler with the black liquor. This flow is similar in magnitude to the flows of black liquor nitrogen exiting the recovery boiler as the gaseous compounds NO and N{sub 2}. The method for cyanate analysis used in this work is presented in the Methods chapter of this thesis and Paper I. The results from nitrogen balances at three European kraft pulp mills are discussed in this thesis and Papers II and III, with a focus on the fate of cyanate in the recovery boiler and recausticizing process. Cyanate exits the recovery boiler with the smelt and reacts to form ammonia in the recausticizing solutions of the chemical recovery cycle. Papers IV and V of this thesis focus on the rate of ammonia formation from cyanate in model solutions and in kraft green liquors. The experiments were carried out at temperatures of 80 to 95 deg C, which are temperatures similar to those found in the recausticizing process of a kraft pulp mill. The kinetic studies help clarify the catalytic effect of bicarbonate. A rate equation applicable for use in describing ammonia formation from cyanate in highly alkaline solutions such as pulp mill recovery streams is presented. The sulfide anion, on the other hand, is a desired product of black liquor combustion as the

  7. Assessing the neurotoxic potential of methyl ethyl ketoxime in rats.

    Science.gov (United States)

    Schulze, G E; Derelanko, M J

    1993-11-01

    The potential of methyl ethyl ketoxime (MEKO) to produce neurotoxicity following acute and subchronic exposure was studied in rats. A Functional Observational Battery, assessment of motor activity, and neuropathology evaluations were conducted in the context of acute and subchronic toxicity studies. Three independent studies are reported: a pilot time-effect study designed to determine the time course and time to peak effect following a single high dose of MEKO, a single-dose neurotoxicity study, and a subchronic (13-week) repeated-dose neurotoxicity study in rats. An acrylamide-positive control group was included in the acute and subchronic studies for comparison with MEKO. Following an acute oral exposure of MEKO at a dose level of 900 mg/kg, locomotor activity was decreased compared to control with maximum decreases occurring between 30 and 60 min following oral administration. In the acute study, transient treatment-related changes in ease of cage removal, ease of handling, and in posture and gait were observed 1 hr after dosing with 900 mg/kg MEKO, as were significant depressions in motor activity. Following a single 300 mg/kg dose, transient MEKO-related changes in gait and aerial righting reflex were noted 1 hr after dosing. All effects were reversible within 24 hr of dosing. The single 100 mg/kg dose of MEKO was without observable effects. No acrylamide-related behavioral effects were noted following a single 50 mg/kg dose. In the subchronic study, transient treatment-related changes in ease of cage removal, ease of handling, and in posture, gait, and aerial righting were observed at the 400 mg/kg/day dose level when assessments were conducted immediately after dose administration. No consistent behavioral effects were observed prior to daily dose administration even after 13 weeks of exposure, indicating a lack of cumulative behavioral effect. No consistent behavioral changes were noted at doses of 125 mg/kg/day and below. Significant dose

  8. Ethyl Pyruvate Ameliorates Hepatic Ischemia-Reperfusion Injury by Inhibiting Intrinsic Pathway of Apoptosis and Autophagy

    Directory of Open Access Journals (Sweden)

    Miao Shen

    2013-01-01

    Full Text Available Background. Hepatic ischemia-reperfusion (I/R injury is a pivotal clinical problem occurring in many clinical conditions such as transplantation, trauma, and hepatic failure after hemorrhagic shock. Apoptosis and autophagy have been shown to contribute to cell death in hepatic I/R injury. Ethyl pyruvate, a stable and simple lipophilic ester, has been shown to have anti-inflammatory properties. In this study, the purpose is to explore both the effect of ethyl pyruvate on hepatic I/R injury and regulation of intrinsic pathway of apoptosis and autophagy. Methods. Three doses of ethyl pyruvate (20 mg/kg, 40 mg/kg, and 80 mg/kg were administered 1 h before a model of segmental (70% hepatic warm ischemia was established in Balb/c mice. All serum and liver tissues were obtained at three different time points (4 h, 8 h, and 16 h. Results. Alanine aminotransferase (ALT, aspartate aminotransferase (AST, and pathological features were significantly ameliorated by ethyl pyruvate (80 mg/kg. The expression of Bcl-2, Bax, Beclin-1, and LC3, which play an important role in the regulation of intrinsic pathway of apoptosis and autophagy, was also obviously decreased by ethyl pyruvate (80 mg/kg. Furthermore, ethyl pyruvate inhibited the HMGB1/TLR4/ NF-κb axis and the release of cytokines (TNF-α and IL-6. Conclusion. Our results showed that ethyl pyruvate might attenuate to hepatic I/R injury by inhibiting intrinsic pathway of apoptosis and autophagy, mediated partly through downregulation of HMGB1/TLR4/ NF-κb axis and the competitive interaction with Beclin-1 of HMGB1.

  9. Cadmium sulfide and lead sulfide quantum dots in glass: Processing, growth, and optical absorption

    Science.gov (United States)

    Rao, Pratima Gattu Naga

    Glasses containing cadmium sulfide and lead sulfide particles were prepared, and their properties were studied. These particles exhibit quantum confinement behavior when they are smaller than their Bohr exciton radii. Quantum confinement leads to size dependence in the optical absorption of particles. This size dependence can tune the optical absorption of the material to a particular wavelength or energy and possibly enhances the nonlinear optical absorption of the particles. These properties have potential applications in photonic devices. To control the growth of these semiconductor particles in glass, the glass processing conditions were studied. CdS-doped glasses were initially prepared with CdO and ZnS. The sublimation temperature for ZnS is at 1185°C; whereas, CdO sublimes at 1559°C, and CdS at 980°C. Loss of both cadmium and sulfur was observed in open crucible melts, even when CdO and ZnS were used. Improvements in glass processing were made by use of preheat and a cover during the glass melting, resulting in better retention of both dopants. Direct CdS addition to the glasses was possible with these improvements, thus eliminating complications of zinc incorporation during the growth of the semiconductor particles. These methods were successfully applied to the synthesis of PbS-doped glasses. CdS and PbS particles were grown in alkali borosilicate glasses, and their optical absorption spectra were measured as a function of heat treatment temperature and time. The position of the absorption peak and edge shifted to longer wave-lengths, or lower energies, with longer heat treatments at a constant temperature. Both CdS and PbS particles exhibited quantum confinement. These measurements were used to calculate particle sizes from quantum confinement models. Comparisons with transmission electron microscopy (TEM) demonstrated that the 1-term effective-mass approximation was appropriate for estimating CdS particle sizes. A sophisticated four-band envelope

  10. The removal of hydrogen sulfide from gas streams using an aqueous metal sulfate absorbent : Part II. the regeneration of copper sulfide to copper oxide - An experimental study

    NARCIS (Netherlands)

    Ter Maat, H.; Hogendoorn, J. A.; Versteeg, G. F.

    2005-01-01

    Aim of this study was to investigate the possibilities for a selective and efficient method to convert copper(II) sulfide (CuS) into copper(II) oxide (CuO). The oxidation of copper sulfide has been studied experimentally using a thermogravimetric analyzer (TGA) at temperatures ranging from 450 to 75

  11. LUMINESCENCE OF CADMIUM SULFIDE QUANTUM DOTS IN FLUOROPHOSPHATE GLASSES

    Directory of Open Access Journals (Sweden)

    Z. O. Lipatova

    2015-03-01

    Full Text Available Cadmium sulfide quantum dots are perspective materials in optics, medicine, biology and optoelectronics. Fluorophosphate glasses, doped with cadmium sulfide quantum dots, were examined in the paper. Heat treatment led to the formation of quantum dots with diameters equal to 2.8 nm, 3.0 nm and 3.8 nm. In view of such changes in the quantum dots size the fundamental absorption edge shift and the luminescence band are being displaced to the long wavelengths. Luminescence lifetime has been found to be dependent on the registration wavelength in the range from 450 to 700 nm. Obtained fluorophosphate glasses with CdS quantum dots can find their application as fluorescent materials with intensive luminescence band and long excited-state natural lifetime.

  12. Oxygen-free atomic layer deposition of indium sulfide

    Science.gov (United States)

    Martinson, Alex B.; Hock, Adam S.; McCarthy, Robert; Weimer, Matthew S.

    2016-07-05

    A method for synthesizing an In(III) N,N'-diisopropylacetamidinate precursor including cooling a mixture comprised of diisopropylcarbodiimide and diethyl ether to approximately -30.degree. C., adding methyllithium drop-wise into the mixture, allowing the mixture to warm to room temperature, adding indium(III) chloride as a solid to the mixture to produce a white solid, dissolving the white solid in pentane to form a clear and colorless solution, filtering the mixture over a celite plug, and evaporating the solution under reduced pressure to obtain a solid In(III) N,N'-diisopropylacetamidinate precursor. This precursor has been further used to develop a novel atomic layer deposition technique for indium sulfide by dosing a reactor with the precursor, purging with nitrogen, dosing with dilute hydrogen sulfide, purging again with nitrogen, and repeating these steps to increase growth.

  13. L-Cysteine-assisted Synthesis of Copper Gallium Sulfide Microspheres

    Institute of Scientific and Technical Information of China (English)

    LIANG Xiao-juan; ZHONG Jia-song; CAI Qian; HUANG Hai-yu; LIU Hai-tao; XIANG Wei-dong; SUN Jun-cai

    2012-01-01

    An effective L-cysteine-assisted synthetic route has been successfully developed to prepare copper gallium sulfide(CuGaS2) microspheres under solvothermal conditions with CuCI2-2H2O,GaCl3 and L-cysteine as source materials,in which L-cysteine was used as the sulfide source and eomplexing molecule.The experiments revealed that the synthesized sample was of a typical CuGaS2 tetragonal structure.Moreover,the prepared CuGaS2 crystals consisting of microspheres made up of nanoflakes,and the diameter of the nanoflakes was about 20 nm.Raman spectrum of the obtained CuGaS2 exhibits a high-intensity peak of the A1 mode at 306 cm-1.Meanwhile,a possible growth mechanism was proposed based on the investigations.

  14. Fractal characteristics of nanocrystalline indium and gallium sulfide particles

    Energy Technology Data Exchange (ETDEWEB)

    Sastry, P.U., E-mail: psastry@barc.gov.i [Solid State Physics Division, Mumbai 400085 (India); Dutta, Dimple P. [Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2009-11-13

    The structure of nano-sized powders of indium sulfide (In{sub 2}S{sub 3}) and gallium sulfide (Ga{sub 2}S{sub 3}), prepared by single source precursor route has been investigated by small angle X-ray scattering technique. The particle morphology shows interesting fractal nature. For In{sub 2}S{sub 3}, the nanoparticle aggregates show a mass fractal with fractal dimension 2.0 that increases with longer time of thermal treatment. Below the length scale of about 20 nm, the particles have a rough surface with a surface fractal dimension of 2.8. Unlike In{sub 2}S{sub 3}, structure of Ga{sub 2}S{sub 3} exhibits a single surface fractal over whole q-range of study. The estimated particle sizes are in range of 5-15 nm and the results are supported by transmission electron microscope.

  15. 'Low-acid' sulfide oxidation using nitrate-enriched groundwater

    Science.gov (United States)

    Donn, Michael; Boxall, Naomi; Reid, Nathan; Meakin, Rebecca; Gray, David; Kaksonen, Anna; Robson, Thomas; Shiers, Denis

    2016-04-01

    Acid drainage (AMD/ARD) is undoubtedly one of the largest environmental, legislative and economic challenges facing the mining industry. In Australia alone, at least 60m is spent on AMD related issues annually, and the global cost is estimated to be in the order of tens of billions US. Furthermore, the challenge of safely and economically storing or treating sulfidic wastes will likely intensify because of the trend towards larger mines that process increasingly higher volumes of lower grade ores and the associated sulfidic wastes and lower profit margins. While the challenge of managing potentially acid forming (PAF) wastes will likely intensify, the industrial approaches to preventing acid production or ameliorating the effects has stagnated for decades. Conventionally, PAF waste is segregated and encapsulated in non-PAF tips to limit access to atmospheric oxygen. Two key limitations of the 'cap and cover' approach are: 1) the hazard (PAF) is not actually removed; only the pollutant linkage is severed; and, 2) these engineered structures are susceptible to physical failure in short-to-medium term, potentially re-establishing that pollutant linkage. In an effort to address these concerns, CSIRO is investigating a passive, 'low-acid' oxidation mechanism for sulfide treatment, which can potentially produce one quarter as much acidity compared with pyrite oxidation under atmospheric oxygen. This 'low-acid' mechanism relies on nitrate, rather than oxygen, as the primary electron accepter and the activity of specifically cultured chemolithoautotrophic bacteria and archaea communities. This research was prompted by the observation that, in deeply weathered terrains of Australia, shallow (oxic to sub-oxic) groundwater contacting weathering sulfides are commonly inconsistent with the geochemical conditions produced by ARD. One key characteristic of these aquifers is the natural abundance of nitrate on a regional scale, which becomes depleted around the sulfide bodies, and

  16. The bioleaching of different sulfide concentrates using thermophilic bacteria

    Science.gov (United States)

    Torres, F.; Blázquez, M. L.; González, F.; Ballester, A.; Mier, J. L.

    1995-05-01

    The bioleaching of different mineral sulfide concentrates with thermophilic bacteria (genus Sulfolobus @#@) was studied. Since the use of this type of bacteria in leaching systems involves stirring and the control of temperature, the influence of the type of stirring and the pulp density on dissolution rates was studied in order to ascertain the optimum conditions for metal recovery. At low pulp densities, the dissolution kinetic was favored by pneumatic stirring, but for higher pulp densities, orbital stirring produced the best results. A comparative study of three differential concentrates, one mixed concentrate, and one global concentrate was made. Copper and iron extraction is directly influenced by bacterial activity, while zinc dissolution is basically due to an indirect mechanism that is activated in the presence of copper ions. Galvanic interactions between the different sulfides favors the selective bioleaching of some phases (sphalerite and chalcopyrite) and leads to high metal recovery rates. However, the formation of galvanic couples depends on the type of concentrate.

  17. Health assessment document for hydrogen sulfide: review draft

    Energy Technology Data Exchange (ETDEWEB)

    Ammann, H.M.; Bradow, F.; Fennell, D.; Griffin, R.; Kearney, B.

    1986-08-01

    Hydrogen sulfide is a highly toxic gas which is immediately lethal in concentrations greater than 2000 ppm. The toxic end-point is due to anoxia to brain and heart tissues which results from its interaction with the celluar enzyme cytochrome oxidase. Inhibition of the enzyme halts oxidative metabolism which is the primary energy source for cells. A second toxic end-point is the irritative effect of hydrogen sulfide on mucous membranes, particularly edema at sublethal doses (250 to 500 ppm) in which sufficient exposure occurs before conciousness is lost. Recovered victims of exposure report neurologic symptoms such as headache, fatigue, irritability, vertigo, and loss of libido. Long-term effects are similar to those caused by anoxia due to other toxic agents like CO, and probably are not due to specific H/sub 2/S effects. H/sub 2/S is not a cumulative poison. No mutagenic, carcinogenic, reproductive, or teratogenic effects have been reported in the literature.

  18. Synthesis and characterization of cerium sulfide thin film

    Institute of Scientific and Technical Information of China (English)

    Ιshak Afsin Kariper

    2014-01-01

    Cerium sulfide (CexSy) polycrystalline thin film is coated with chemical bath deposition on substrates (commercial glass). Transmittance, absorption, optical band gap and refractive index are examined by using UV/VIS. Spectrum. The hexagonal form is observed in the structural properties in XRD. The structural and optical properties of cerium sulfide thin films are analyzed at different pH. SEM and EDX analyses are made for surface analysis and elemental ratio in films. It is observed that some properties of films changed with different pH values. In this study, the focus is on the observed changes in the properties of films. The pH values were scanned at 6–10. The optical band gap changed with pH between 3.40 to 3.60 eV. In addition, the film thickness changed with pH at 411 nm to 880 nm.

  19. Oxygen-free atomic layer deposition of indium sulfide

    Energy Technology Data Exchange (ETDEWEB)

    Martinson, Alex B.; Hock, Adam S.; McCarthy, Robert; Weimer, Matthew S.

    2016-07-05

    A method for synthesizing an In(III) N,N'-diisopropylacetamidinate precursor including cooling a mixture comprised of diisopropylcarbodiimide and diethyl ether to approximately -30.degree. C., adding methyllithium drop-wise into the mixture, allowing the mixture to warm to room temperature, adding indium(III) chloride as a solid to the mixture to produce a white solid, dissolving the white solid in pentane to form a clear and colorless solution, filtering the mixture over a celite plug, and evaporating the solution under reduced pressure to obtain a solid In(III) N,N'-diisopropylacetamidinate precursor. This precursor has been further used to develop a novel atomic layer deposition technique for indium sulfide by dosing a reactor with the precursor, purging with nitrogen, dosing with dilute hydrogen sulfide, purging again with nitrogen, and repeating these steps to increase growth.

  20. Effect of Potent Ethyl Acetate Fraction of Stereospermum suaveolens Extract in Streptozotocin-Induced Diabetic Rats

    Directory of Open Access Journals (Sweden)

    T. Balasubramanian

    2012-01-01

    Full Text Available To evaluate the antihyperglycemic effect of ethyl acetate fraction of ethanol extract of Stereospermum suaveolens in streptozotocin-(STZ- induced diabetic rats by acute and subacute models. In this paper, various fractions of ethanol extract of Stereospermum suaveolens were prepared and their effects on blood glucose levels in STZ-induced diabetic rats were studied after a single oral administration (200?mg/kg. Administration of the ethyl acetate fraction at 200?mg/kg once daily for 14 days to STZ-induced diabetic rats was also carried out. The parameters such as the fasting blood glucose, hepatic glycogen content, and pancreatic antioxidant levels were monitored. In the acute study, the ethyl acetate fraction is the most potent in reducing the fasting serum glucose levels of the STZ-induced diabetic rats. The 14-day repeated oral administration of the ethyl acetate fraction significantly reduced the fasting blood glucose and pancreatic TBARS level and significantly increased the liver glycogen, pancreatic superoxide dismutase, and catalase activities as well as reduced glutathione levels. The histopathological studies during the subacute treatment have been shown to ameliorate the STZ-induced histological damage of pancreas. This paper concludes that the ethyl acetate fraction from ethanol extract of Stereospermum suaveolens possesses potent antihyperglycemic and antioxidant properties, thereby substantiating the use of plant in the indigenous system of medicine.

  1. Antihyperglycemic effect of Hypericum perforatum ethyl acetate extract on streptozotocin-induced diabetic rats

    Institute of Scientific and Technical Information of China (English)

    Arokiyaraj S; Balamurugan R; Augustian P

    2011-01-01

    Objective: To evaluate the antihyperglycemic activity of ethyl acetate extract of Hypericum perforatum (H. perforatum) in streptozotocin (STZ)-induced diabetic rats. Methods: Acute toxicity and oral glucose tolerance test were performed in normal rats. Male albino rats were rendered diabetic by STZ (40 mg/kg, intraperitoneally). H. perforatum ethyl acetate extract was orally administered to diabetic rats at 50, 100 and 200 mg/kg doses for 15 days to determine the antihyperglycemic activity. Biochemical parameters were determined at the end of the treatment.Results: H. perforatum ethyl acetate extract showed dose dependant fall in fasting blood glucose (FBG). After 30 min of extract administration, FBG was reduced significantly when compared with normal rats. H. perforatum ethyl acetate extract produced significant reduction in plasma glucose level, serum total cholesterol, triglycerides, glucose-6-phosphatase levels. Tissue glycogen content, HDL-cholesterol, glucose-6-phosphate dehydrogenase were significantly increased compared with diabetic control. No death or lethal effect was observed in the toxic study.Conclusions:The results demonstrate that H. perforatum ethyl acetate extract possesses potent antihyperglycemic activity in STZ induced diabetic rats.

  2. Effect of vanillin and ethyl vanillin on cytochrome P450 activity in vitro and in vivo.

    Science.gov (United States)

    Chen, Xiao-min; Wei, Min; Zhang, Hai-mou; Luo, Cheng-hao; Chen, Yi-kun; Chen, Yong

    2012-06-01

    Food safety is of extreme importance to human health. Vanillin and ethyl vanillin are the widely used food additives and spices in foods, beverages, cosmetics and drugs. The objective of the present work was to evaluate the impact of vanillin and ethyl vanillin on the activities of CYP2C9, CYP2E1, CYP3A4, CYP2B6 and CYP1A2 in human liver microsomes (HLM) in vitro, and impact on the activities of CYP1A2, CYP2C, CYP3A and CYP2E1 in rat liver microsomes (RLM) in vivo. The in vitro results demonstrated that vanillin and ethyl vanillin had no significant effect on the activity of five human CYP450 enzymes with concentration ranged from 8 to 128 μM. However, after rats were orally administered vanillin or ethyl vanillin once a day for seven consecutive days, CYP2E1 activity was increased and CYP1A2 activity was decreased in RLM. The in vivo results revealed that drug interaction between vanillin/ethyl vanillin and the CYP2E1/CYP1A2-metabolizing drugs might be possible, and also suggested that the application of the above additives in foods and drugs should not be unlimited so as to avoid the adverse interaction.

  3. Ethyl Radical Ejection During Photodecomposition of Butanone on TiO2(110)

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, Michael A.

    2008-10-15

    The photodecomposition of acetone and butanone were examined on the (110) surface of rutile TiO2 using temperature programmed desorption (TPD) and photon stimulated desorption (PSD). In both cases, photodecomposition was proceeded by a required thermal reaction between the adsorbed ketone and coadsorbed oxygen resulting in a diolate species. The diolate photodecomposed by ejection of an organic radical from the surface leaving behind a carboxylate species. In the acetone case, only methyl radical PSD was detected and acetate was left on the surface. In the butanone case there was a possibility of either methyl or ethyl radical ejection, with propionate or acetate left behind, respectively. However, only ethyl radical PSD was detected and the species left on the surface (acetate) was the same as in the acetone case. The preference for ethyl radical ejection is linked to the greater thermal stability of the ethyl radical over that of the methyl radical. Unlike in the acetone case, where the ejected methyl radicals did not participate in thermal chemistry on the TiO2(110) surface after photoactivation of the acetone diolate, ethyl radicals photodesorbing at 100 K from butanone diolate showed a preference for dehydrogenation to ethene through the influence of coadsorbed oxygen. These results reemphasize the mechanistic importance of organic radical production during photooxidation reactions on TiO2 surface. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

  4. Laboratory SIP signatures associated with oxidation of disseminated metal sulfides

    Science.gov (United States)

    Placencia-Gómez, Edmundo; Slater, Lee; Ntarlagiannis, Dimitrios; Binley, Andrew

    2013-05-01

    Oxidation of metal sulfide minerals is responsible for the generation of acidic waters rich in sulfate and metals. When associated with the oxidation of sulfide ore mine waste deposits the resulting pore water is called acid mine drainage (AMD); AMD is a known environmental problem that affects surface and ground waters. Characterization of oxidation processes in-situ is challenging, particularly at the field scale. Geophysical techniques, spectral induced polarization (SIP) in particular, may provide a means of such investigation. We performed laboratory experiments to assess the sensitivity of the SIP method to the oxidation mechanisms of common sulfide minerals found in mine waste deposits, i.e., pyrite and pyrrhotite, when the primary oxidant agent is dissolved oxygen. We found that SIP parameters, e.g., phase shift, the imaginary component of electrical conductivity and total chargeability, decrease as the time of exposure to oxidation and oxidation degree increase. This observation suggests that dissolution-depletion of the mineral surface reduces the capacitive properties and polarizability of the sulfide minerals. However, small increases in the phase shift and imaginary conductivity do occur during oxidation. These transient increases appear to correlate with increases of soluble oxidizing products, e.g., Fe2 + and Fe3 + in solution; precipitation of secondary minerals and the formation of a passivating layer to oxidation coating the mineral surface may also contribute to these increases. In contrast, the real component of electrical conductivity associated with electrolytic, electronic and interfacial conductance is sensitive to changes in the pore fluid chemistry as a result of the soluble oxidation products released (Fe2 + and Fe3 +), particularly for the case of pyrrhotite minerals.

  5. Aromatic and heterocyclic perfluoroalkyl sulfides. Methods of preparation

    Directory of Open Access Journals (Sweden)

    Vladimir N. Boiko

    2010-08-01

    Full Text Available This review covers all of the common methods for the syntheses of aromatic and heterocyclic perfluoroalkyl sulfides, a class of compounds which is finding increasing application as starting materials for the preparation of agrochemicals, pharmaceutical products and, more generally, fine chemicals. A systematic approach is taken depending on the mode of incorporation of the SRF groups and also on the type of reagents used.

  6. Fabrication and applications of copper sulfide (CuS) nanostructures

    Science.gov (United States)

    Shamraiz, Umair; Hussain, Raja Azadar; Badshah, Amin

    2016-06-01

    This review article presents different fabrication procedures (under the headlines of solvothermal routes, aerosol methods, solution methods and thermolysis), and applications (photocatalytic degradation, ablation of cancer cells, electrode material in lithium ion batteries and in gas sensing, organic solar cells, field emission properties, super capacitor applications, photoelectrochemical performance of QDSCs, photocatalytic reduction of organic pollutants, electrochemical bio sensing, enhanced PEC characteristics of pre-annealed CuS film electrodes) of copper sulfide (Covellite).

  7. Formation of iron sulfide nodules during anaerobic oxidation

    OpenAIRE

    van Dongen, B. E.; Organic Geochemistry Unit, Bristol Biogeochemistry Research Centre, School of Chemistry, Cantock’s Close, Bristol University, Bristol BS8 1TS, United Kingdom; Roberts, A. P.; National Oceanography Centre, University of Southampton, Southampton, UK.; Schouten, S.; Department of Marine Biogeochemistry, Royal Netherlands Institute for Sea Research, P.O. Box 59, 1790 AB Den Burg, Texel, The Netherlands; Jiang, W-T; Department of Earth Sciences, National Cheng Kung University, Tainan 70101, Taiwan, PR China; Florindo, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Pancost, R. D.; Organic Geochemistry Unit, Bristol Biogeochemistry Research Centre, School of Chemistry, Cantock’s Close, Bristol University, Bristol BS8 1TS, United Kingdom

    2007-01-01

    The biomarker compositions of iron sulfide nodules (ISNs; upper Pliocene Valle Ricca section near Rome, Italy) that contain the ferrimagnetic mineral greigite (Fe3S4) were examined. In addition to the presence of specific terrestrial and marine biomarkers, consistent with formation in coastal marine sediments, these ISNs contain compounds thought to originate from sulfate reducing bacteria (SRB). These compounds include a variety of low-molecular-weight and branched alkanols and seve...

  8. Discrimination among iron sulfide species formed in microbial cultures.

    Science.gov (United States)

    Popa, R; Kinkle, B K

    2000-10-01

    A quantitative method for the study of iron sulfides precipitated in liquid cultures of bacteria is described. This method can be used to quantify and discriminate among amorphous iron sulfide (FeS(amorph)), iron monosulfide minerals such as mackinawite or greigite (FeS(min)), and iron disulfide minerals such as pyrite or marcasite (FeS(2min)) formed in liquid cultures. Degradation of iron sulfides is performed using a modified Cr(2+) reduction method with reflux distillation. The basic steps of the method are: first, separation of FeS(amorph); second, elimination of interfering species of S such as colloidal sulfur (S(c) degrees ), thiosulphate (S(2)O(3)(2-)) and polysulfides (S(x)(2-)); third, separation of FeS(min); and fourth, separation of FeS(2min). The final product is H(2)S which is determined after trapping. The efficiency of recovery is 96-99% for FeS(amorph), 76-88% for FeS(min), and >97% for FeS(2min). This method has a high reproducibility if the experimental conditions are rigorously applied and only glass conduits are used. A well ventilated fume hood must be used because of the toxicity and volatility of several reagents and products. The advantage relative to previously described methods are better resolution for iron sulfide species and use of the same bottles for both incubation of cultures and acid degradation. The method can also be used for Fe/S stoichiometry with sub-sampling and Fe analysis. PMID:11018273

  9. Delivering carbide ligands to sulfide-rich clusters.

    Science.gov (United States)

    Reinholdt, Anders; Herbst, Konrad; Bendix, Jesper

    2016-02-01

    The propensity of the terminal ruthenium carbide Ru(C)Cl2(PCy3)2 (RuC) to form carbide bridges to electron-rich transition metals enables synthetic routes to metal clusters with coexisting carbide and sulfide ligands. Electrochemical experiments show the Ru≡C ligand to exert a relatively large electron-withdrawing effect compared with PPh3, effectively shifting redox potentials.

  10. The use of 14C ethanolamine as a precursor

    International Nuclear Information System (INIS)

    Two new 2 chloroethyl nitrosoureas were labelled on two positions by 14C starting from Na14CN and using 14C ethanolamine as intermediate, i.e. on the carbon 2 of the 2 chloro ethyl group and on the carbon 2 of the cysteamine part. (author)

  11. Selective Facet Reactivity During Cation Exchange in Cadmium Sulfide Nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Sadtler, Bryce; Demchenko, Denis; Zheng, Haimei; Hughes, Steven; Merkle, Maxwell; Dahmen, Ulrich; Wang, Lin-Wang; Alivisatos, A. Paul

    2008-12-18

    The partial transformation of ionic nanocrystals through cation exchange has been used to synthesize nanocrystal heterostructures. We demonstrate that the selectivity for cation exchange to take place at different facets of the nanocrystal plays an important role in determining the resulting morphology of the binary heterostructure. In the case of copper I (Cu+) cation exchange in cadmium sulfide (CdS) nanorods, the reaction starts preferentially at the ends of the nanorods such that copper sulfide (Cu2S) grows inwards from either end. The resulting morphology is very different from the striped pattern obtained in our previous studies of silver I (Ag+) exchange in CdS nanorods where non-selective nucleation of silver sulfide (Ag2S) occurs. From interface formation energies calculated for several models of epitaxialconnections between CdS and Cu2S or Ag2S, we infer the relative stability of each interface during the nucleation and growth of Cu2S or Ag2S within the CdS nanorods. The epitaxial connections of Cu2S to the end facets of CdS nanorods minimize the formation energy, making these interfaces stable throughout the exchange reaction. However, as the two end facets of wurtzite CdS nanorods are crystallographically nonequivalent, asymmetric heterostructures can be produced.

  12. Sulfide Capacity in Ladle Slag at Steelmaking Temperatures

    Science.gov (United States)

    Allertz, Carl; Sichen, Du

    2015-12-01

    Sulfide capacity measurements were conducted at 1823 K and 1873 K (1550 °C and 1600 °C) for the quaternary Al2O3-CaO-MgO-SiO2 system, for typical compositions used in the ladle in steelmaking. A copper-slag equilibrium was used under controlled oxygen and sulfur potentials. The sulfide capacity is strongly dependent on the composition and it was found to increase with the basic oxides, while it decreases with increase of the acidic components. It was found that CaO is more effective in holding sulfur in the slag compared to MgO when replacing SiO2. For the present slag compositions, Al2O3 and SiO2 behaved similar with respect to sulfur, and no considerable effect could be recorded when replacing one for the other. The sulfide capacity was also found to be strongly dependent on the temperature, increasing with temperature. The present results were compared with industrial data from the ladle, after vacuum treatment, and they were in good agreement.

  13. [The balneotherapeutic components of sulfide-containing mineral waters].

    Science.gov (United States)

    Khutoryansky, V A; Gorshkov, A G

    2015-01-01

    It has been suggested in an early study that sulfanes may serve as a source of sulfur contained in hydrogen sulfide sources. We have performed derivatization of sulfanes, known to be present in the "Novonukutskaya" mineral water. The presence of polysulfanes in balneotherapeutic sulfide waters was confirmed by the HPLC-UV and chromato-mass spectrometric techniques. Derivatization of inorganic polysulfides was achieved by using the reaction with methyl iodide. It was shown that polysulfanes contained in the examined samples were metastable and disintegrated into So and H2S. Almost all molecular zero-valent sulfur was present in the form of S8. The application of HPLC allowed to determine the equilibrium concentration of molecular sulfur. The presence of the above compounds in therapeutic sulfide waters raises the question of the mechanism of their curative action. The authors hypothesize that it may be related to the high therapeutic potency of the substances obtained by steam distillation from the "Novonukutskaya" mineral water. PMID:26841531

  14. Oxidative decarboxylation of mandelic acid derivative by recombinant Escherichia coli: a novel method of ethyl vanillin synthesis.

    Science.gov (United States)

    Pan, Xiao-Xia; Li, Jing-Jing; Wang, Mei-Gui; He, Wen-Sen; Jia, Cheng-Sheng; Zhang, Xiao-Ming; Feng, Biao; Li, Da-Li; Zeng, Zeng

    2013-06-01

    The benzoylformate decarboxylase gene (mdlC) from Pseudomonas putida was expressed in Escherichia coli BL21(DE3). The recombinant strain together with E. coli/pET30a-mdlB converted (S)-3-ethoxy-4-hydroxymandelic acid (S-EMA) into ethyl vanillin without ethyl vanillin degradation. 4 g ethyl vanillin/l was obtained from 10 g EMA/l within 12 h at 30 °C. This is the first report on the biotransformation of (S)-EMA to ethyl vanillin.

  15. All-Weather Hydrogen Peroxide-Based Decontamination of CBRN Contaminants

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, George W. [U.S. Army Edgewood Chemical Biological Center (ECBC), Aberdeen Proving Ground, MD (United States); Procell, Lawrence R. [U.S. Army Edgewood Chemical Biological Center (ECBC), Aberdeen Proving Ground, MD (United States); Sorrick, David C. [U.S. Army Edgewood Chemical Biological Center (ECBC), Aberdeen Proving Ground, MD (United States); Lawson, Glenn E. [Naval Surface Warfare Center (NSWC), Dahlgren, VA (United States); Wells, Claire M. [Naval Surface Warfare Center (NSWC), Dahlgren, VA (United States); Reynolds, Charles M. [U.S. Army Cold Regions Research and Engineering Lab. (CRREL), Hanover, NH (United States); Ringelberg, D. B. [U.S. Army Cold Regions Research and Engineering Lab. (CRREL), Hanover, NH (United States); Foley, Karen L. [U.S. Army Cold Regions Research and Engineering Lab. (CRREL), Hanover, NH (United States); Lumetta, Gregg J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Blanchard, David L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2010-03-11

    A hydrogen peroxide-based decontaminant, Decon Green, is efficacious for the decontamination of chemical agents VX (S-2-(diisopropylamino)ethyl O-ethyl methylphosphonothioate), GD (Soman, pinacolyl methylphosphonofluoridate), and HD (mustard, bis(2-chloroethyl) sulfide); the biological agent anthrax (Bacillus anthracis); and radiological isotopes Cs-137 and Co-60; thus demonstrating the ability of this decontamination approach to ameliorate the aftermath of all three types of weapons of mass destruction (WMD). Reaction mechanisms afforded for the chemical agents are discussed as are rationales for the enhanced removal efficacy of recalcitrant 60Co on certain surfaces. Decontaminants of this nature can be deployed, and are effective, at very low temperatures (-32 °C), as shown for studies done with VX and HD simulants, without the need for external heat sources. Finally, the efficacy of a lower-logistics, dry decontaminant powder concentrate (utilizing the solid active-oxygen compounds peracetyl borate and Peroxydone) which can be reconstituted with water in the field prior to use, is presented.

  16. Zirconium doped nano-dispersed oxides of Fe, Al and Zn for destruction of warfare agents

    Energy Technology Data Exchange (ETDEWEB)

    Stengl, Vaclav, E-mail: stengl@uach.cz [Institute of Inorganic Chemistry AS CR v.v.i., 250 68 Rez (Czech Republic); Houskova, Vendula; Bakardjieva, Snejana; Murafa, Nataliya; Marikova, Monika [Institute of Inorganic Chemistry AS CR v.v.i., 250 68 Rez (Czech Republic); Oplustil, Frantisek; Nemec, Tomas [Military Technical Institute of Protection Brno, Veslarska 230, 628 00 Brno (Czech Republic)

    2010-11-15

    Zirconium doped nano dispersive oxides of Fe, Al and Zn were prepared by a homogeneous hydrolysis of the respective sulfate salts with urea in aqueous solutions. Synthesized metal oxide hydroxides were characterized using Brunauer-Emmett-Teller (BET) surface area and Barrett-Joiner-Halenda porosity (BJH), X-ray diffraction (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM) and energy-dispersive X-ray microanalysis (EDX). These oxides were taken for an experimental evaluation of their reactivity with sulfur mustard (HD or bis(2-chloroethyl)sulfide), soman (GD or (3,3'-Dimethylbutan-2-yl)-methylphosphonofluoridate) and VX agent (S-[2-(diisopropylamino)ethyl]-O-ethyl-methylphosphonothionate). The presence of Zr{sup 4+} dopant can increase both the surface area and the surface hydroxylation of the resulting doped oxides, decreases their crystallites' sizes thereby it may contribute in enabling the substrate adsorption at the oxide surface thus it can accelerate the rate of degradation of warfare agents. Addition of Zr{sup 4+} converts the product of the reaction of ferric sulphate with urea from ferrihydrite to goethite. We found out that doped oxo-hydroxides Zr-FeO(OH) - being prepared by a homogeneous hydrolysis of ferric and zirconium oxo-sulfates mixture in aqueous solutions - exhibit a comparatively higher degradation activity towards chemical warfare agents (CWAs). Degradation of soman or VX agent on Zr-doped FeO(OH) containing ca. 8.3 wt.% of zirconium proceeded to completion within 30 min.

  17. The Role of Hydrogen Sulfide in Evolution and the Evolution of Hydrogen Sulfide in Metabolism and Signaling.

    Science.gov (United States)

    Olson, Kenneth R; Straub, Karl D

    2016-01-01

    The chemical versatility of sulfur and its abundance in the prebiotic Earth as reduced sulfide (H2S) implicate this molecule in the origin of life 3.8 billion years ago and also as a major source of energy in the first seven-eighths of evolution. The tremendous increase in ambient oxygen ∼ 600 million years ago brought an end to H2S as an energy source, and H2S-dependent animals either became extinct, retreated to isolated sulfide niches, or adapted. The first 3 billion years of molecular tinkering were not lost, however, and much of this biochemical armamentarium easily adapted to an oxic environment where it contributes to metabolism and signaling even in humans. This review examines the role of H2S in evolution and the evolution of H2S metabolism and signaling. PMID:26674552

  18. A recovery installation for sodium sulfates, thiosulfates and sulfides from waste water resulting from hydrogen sulfide fabrication

    International Nuclear Information System (INIS)

    An installation for recovery of sodium sulfate and sulfur suspensions from waste water was conceived. It consists from a preheater, vacuum evaporator and a refrigerating system with drum and scraper. This equipment concentration the solution by eliminating in the first stage the water in the vacuum evaporator. The water resulting at this stage is chemically pure and can be discharged in the sewage sludge system. The concentrated solution is then directed to the refrigerating system with drum and scrapper. Here the sodium sulfates, thiosulfates and sulfides get crystallized onto the drum surface. The resulting aqueous solution to be discharged in the sewage sludge system is previously analyzed as in case of the absent of the recovery installation, but the amount of pollutants will be much lower because sulfates, thiosulfates and sulfides were already recovered as scales from the drum. These solid scales can be used in detergent industry

  19. Optimization of the production of ethyl esters by ultrasound assisted reaction of soybean oil and ethanol

    Directory of Open Access Journals (Sweden)

    S. Rodrigues

    2009-06-01

    Full Text Available Biodiesel is a renewable liquid fuel that can be produced by a transesterification reaction between a vegetable oil and an alcohol. This paper evaluates and optimizes the production of ethyl esters (biodiesel from soybean oil and ethanol. The reaction was carried out by applying ultrasound under atmospheric pressure and ambient temperature. Response surface methodology was used to evaluate the influence of alcohol to oil molar ratio and catalyst concentration on the yield of conversion of soybean oil into ethyl esters. The process resulted in a maximum yield of 91.8% after 30 minutes of reaction. The process variables alcohol to oil ratio and catalyst to oil ratio were statistically significant regarding the yield of ethyl esters. The optimal operating condition was obtained applying an alcohol to oil molar ratio of 10.2 and a catalyst to oil weight ratio of 0.0035.

  20. Papain-Catalyzed Chemoenzymatic Synthesis of Telechelic Polypeptides Using Bis(Leucine Ethyl Ester) Initiator.

    Science.gov (United States)

    Tsuchiya, Kousuke; Numata, Keiji

    2016-07-01

    In order to construct unique polypeptide architectures, a novel telechelic-type initiator with two leucine ethyl ester units is designed for chemoenzymatic polymerization. Glycine or alanine ethyl ester is chemoenzymatically polymerized using papain in the presence of the initiator, and the propagation occurs at each leucine ethyl ester unit to produce the telechelic polypeptide. The formation of the telechelic polypeptides is confirmed by (1) H NMR and MALDI-TOF mass spectroscopies. It is revealed by AFM observation that long nanofibrils are formed from the telechelic polyalanine, whereas a conventional linear polyalanine with a similar degree of polymerization shows granule-like structures. The telechelic polyglycine and polyalanine show the crystalline structures of Polyglycine II and antiparallel β-sheet, respectively. It is demonstrated that this method to synthesize telechelic-type polypeptides potentially opens up a pathway to construct novel hierarchical structures by self-assembly. PMID:26947148

  1. Direct Conversion of Cellulose into Ethyl Lactate in Supercritical Ethanol-Water Solutions.

    Science.gov (United States)

    Yang, Lisha; Yang, Xiaokun; Tian, Elli; Lin, Hongfei

    2016-01-01

    Biomass-derived ethyl lactate is a green solvent with a growing market as the replacement for petroleum-derived toxic organic solvents. Here we report, for the first time, the production of ethyl lactate directly from cellulose with the mesoporous Zr-SBA-15 silicate catalyst in a supercritical mixture of ethanol and water. The relatively strong Lewis and weak Brønsted acid sites on the catalyst, as well as the surface hydrophobicity, were beneficial to the reaction and led to synergy during consecutive reactions, such as depolymerization, retro-aldol condensation, and esterification. Under the optimum reaction conditions, ∼33 % yield of ethyl lactate was produced from cellulose with the Zr-SBA-15 catalyst at 260 °C in supercritical 95:5 (w/w) ethanol/water.

  2. TOXICOLOGICAL STUDIES AND CYTOTOXIC ACTIVITY OF ETHANOL AND ETHYL ACETATE EXTRACTS OF TECOMARIA CAPENSIS LEAVES

    Directory of Open Access Journals (Sweden)

    E. Tamil Jothi

    2013-06-01

    Full Text Available In the present study ethyl acetate and ethanol extracts of leaves of Tecomaria capensis was screened for cytotoxic activity. The cytotoxic activity was performed by two models. One was short term cytotoxicity and another was long term cytotoxicity. In short term cytotoxicity assay Dalton’s lymphoma ascites (DLA and Ehrlich ascites carcinoma (EAC cell lines were used and for long term L929 cell lines (Lungs fibroblast were used. In both methods ethyl acetate and ethanol extracts showed protective action against the cell lines. Comparing both extracts, ethanol extract has shown better cytotoxic activity than the ethyl acetate extract and in comparison of standard both extracts have moderate cytotoxic activity.

  3. Experimental Autoignition of C4-C6 Saturated and Unsaturated Methyl and Ethyl Esters

    CERN Document Server

    Bennadji, Hayet; Coniglio-Jaubert, Lucie; Billaud, Francis; Glaude, Pierre-Alexandre; Battin-Leclerc, Frédérique

    2009-01-01

    Autoignition delay times, ?, of methyl crotonate, methyl acrylate, ethyl butanoate, ethyl crotonate, and ethyl acrylate were studied in shock tube experiments. A series of mixtures diluted with argon, of varying fuel/oxygen equivalence ratios (?=0.25, 0.4, 1.0, and 2.0), were measured behind reflected shock waves over the temperature range of 1280-1930 K, pressure range of 7-9.65 atm, during which the logarithm of ? varies linearly as a function of the inverse temperature for all equivalence ratios. The ignition delay time decreases as temperature rises. The dependence of ? on temperature, and reactant concentrations is given in an empirical correlation. The results provide a database for the validation of small saturated and unsaturated esters kinetic mechanisms at elevated temperatures and pressure combustion.

  4. Direct Conversion of Cellulose into Ethyl Lactate in Supercritical Ethanol-Water Solutions.

    Science.gov (United States)

    Yang, Lisha; Yang, Xiaokun; Tian, Elli; Lin, Hongfei

    2016-01-01

    Biomass-derived ethyl lactate is a green solvent with a growing market as the replacement for petroleum-derived toxic organic solvents. Here we report, for the first time, the production of ethyl lactate directly from cellulose with the mesoporous Zr-SBA-15 silicate catalyst in a supercritical mixture of ethanol and water. The relatively strong Lewis and weak Brønsted acid sites on the catalyst, as well as the surface hydrophobicity, were beneficial to the reaction and led to synergy during consecutive reactions, such as depolymerization, retro-aldol condensation, and esterification. Under the optimum reaction conditions, ∼33 % yield of ethyl lactate was produced from cellulose with the Zr-SBA-15 catalyst at 260 °C in supercritical 95:5 (w/w) ethanol/water. PMID:26685114

  5. Influence of sulfide concentration on the corrosion behavior of pure copper in synthetic seawater

    Science.gov (United States)

    Taniguchi, Naoki; Kawasaki, Manabu

    2008-09-01

    Corrosion rate and stress corrosion cracking (SCC) behavior of pure copper under anaerobic conditions were studied by immersion tests and slow strain rate tests (SSRT) in synthetic seawater containing Na 2S. The corrosion rate was increased with sulfide concentration both in simple saline solution and in bentnite-sand mixture. The results of SSRT showed that copper was susceptible to intergranular attack; selective dissolution at lower sulfide concentration (less than 0.005 M) and SCC at higher sulfide concentration (0.01 M). It was expected that if the sulfide concentration in groundwater is less than 0.001 M, pure copper is possible to exhibit superior corrosion resistance under anaerobic condition evident by very low corrosion rates and immunity to SCC. In such a low sulfide environment, copper overpack has the potential to achieve super-long lifetimes exceeding several tens of thousands years according to long-term simulations of corrosion based on diffusion of sulfide in buffer material.

  6. Regulation of bacterial sulfate reduction and hydrogen sulfide fluxes in the central Namibian coastal upwelling zone

    DEFF Research Database (Denmark)

    Bruchert, V.; Jørgensen, BB; Neumann, K.;

    2003-01-01

    and the low capacity to oxidize and trap sulfide. The inner shelf break marks the seaward border of sulfidic bottom waters, and separates two different regimes of bacterial sulfate reduction. In the sulfidic bottom waters on the shelf, up to 55% of sulfide oxidation is mediated by the large nitrate......The coastal upwelling system off central Namibia is one of the most productive regions of the oceans and is characterized by frequently occurring shelf anoxia with severe effects for the benthic life and fisheries. We present data on water column dissolved oxygen, sulfide, nitrate and nitrite, pore...... water profiles for dissolved,sulfide and sulfate, S-35-sulfate reduction rates, as well as bacterial counts of large sulfur bacteria from 20 stations across the continental shelf and slope. The stations covered two transects and included the inner shelf with its anoxic and extremely oxygen...

  7. When can Electrochemical Techniques give Reliable Corrosion Rates on Carbon Steel in Sulfide Media?

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel; Hemmingsen, Tor; Nielsen, Lars Vendelbo;

    2005-01-01

    Effects of film formation on carbon steel in hydrogen sulfide media may corrupt corrosion rate monitoring by electrochemical techniques. Electrochemical data from hydrogen sulfide solutions, biological sulfide media and natural sulfide containing geothermal water have been collected and the process...... of film formation in sulfide solutions was followed by video. It can be shown that capacitative and diffusional effects due to porous reactive deposits tend to dominate the data resulting in unreliable corrosion rates measured by electrochemical techniques. The effect is strongly increased if biofilm...... in combination with ferrous sulfide corrosion products cover the steel surface. Corrosion rates can be overestimated by a factor of 10 to 100 with electrochemical techniques - both by linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS). Oxygen entering the system accelerates...

  8. Modeling of hydrogen sulfide oxidation in concrete corrosion products from sewer pipes.

    Science.gov (United States)

    Jensen, Henriette Stokbro; Nielsen, Asbjørn Haaning; Hvitved-Jacobsen, Thorkild; Vollertsen, Jes

    2009-04-01

    Abiotic and biotic oxidation of hydrogen sulfide related to concrete corrosion was studied in corrosion products originating from a sewer manhole. The concrete corrosion products were suspended in an acidic solution, mimicking the conditions in the pore water of corroded concrete. The removal of hydrogen sulfide and dissolved oxygen was measured in parallel in the suspension, upon which the suspension was sterilized and the measurement repeated. The results revealed the biotic oxidation to be fast compared with the abiotic oxidation. The stoichiometry of the hydrogen sulfide oxidation was evaluated using the ratio between oxygen and hydrogen sulfide uptake. The ratio for the biotic oxidation pointed in the direction of elemental sulfur being formed as an intermediate in the oxidation of hydrogen sulfide to sulfuric acid. The experimental results were applied to suggest a hypothesis and a mathematical model describing the hydrogen sulfide oxidation pathway in a matrix of corroded concrete.

  9. Microbial control of the production of hydrogen sulfide by sulfate-reducing bacteria.

    Science.gov (United States)

    Montgomery, A D; McLnerney, M J; Sublette, K L

    1990-03-01

    A sulfide-resistant ctrain of Thiobacillus denitrificans, strain F, prevented the accumulation of sulfide by Desulfovibrio desulfuricans when both organisms were grown in liquid medium or in Berea sandstone cores. The wild-type strain of T. denitrificans did not prevent the accumulation of sulfide produced by D. desulfuricans. Strain F also prevented the accumulation of sulfide by a mixed population of sulfate-reducing bacteria enriched from an oil field brine. Fermentation balances showed that strain F stoichiometrically oxidized the sulfide produced by D. desulfuricans and the oil field brine enrichment to sulfate. These data suggest that strain F would be effective in controlling sulfide production in oil reservoirs and other environments.

  10. Efeitos do trinexapac-ethyl sobre o crescimento e florescimento da grama-batatais Effects of trinexapac-ethyl on the growth and flowering of the bahiagrass

    Directory of Open Access Journals (Sweden)

    F.C.L. Freitas

    2002-12-01

    Full Text Available O objetivo deste trabalho foi avaliar a eficiência de doses do trinexapac-ethyl, bem como dos intervalos de aplicação após o corte no crescimento vegetativo e florescimento da grama-batatais (Paspalum notatum, na redução de cortes e na melhoria da qualidade do gramado. O ensaio foi conduzido no campus da Universidade Federal de Viçosa, em Viçosa-MG, entre os meses de dezembro de 1998 e março de 1999, em gramado estabelecido. O delineamento experimental foi o de blocos ao acaso, com 13 tratamentos e quatro repetições, distribuídos em esquema fatorial (6 x 2 + 1, com seis doses de trinexapac-ethyl (0,00; 0,25; 0,50; 0,75; 1,00; e 1,25 kg ha-1, aplicadas aos dois e cinco dias após o corte do gramado, e uma testemunha com cortes a cada três semanas. Foram efetuadas avaliações a três, seis, nove e doze semanas após o corte, para produção de biomassa seca total, altura e número de inflorescências. Verificou-se, para todas as características avaliadas, relação direta entre o aumento da dose do regulador de crescimento trinexapac-ethyl e o período de controle do crescimento vegetativo e do florescimento, evitando-se, com isso, cortes no gramado pelo período de até 12 semanas com a aplicação de 0,75 kg ha-1. Não se constatou efeito da época de aplicação e também de doses do trinexapac-ethyl sobre a coloração do gramado.The objective of this work was to evaluate the efficiency of doses and application intervals of trinexapac-ethyl on the vegetative growth and flowering of bahiagrass, to reduce clips and improve lawn quality. The experiment was conducted on the campus of the Federal University of Viçosa, in Viçosa-MG - Brazil, from December 1998 to March 1999, in an established lawn. The experiment was arranged in a randomized complete block design, with 13 treatments and four repetitions, distributed in a factorial scheme (6 x 2 + 1, with six doses of trinexapac-ethyl (0.00; 0.25; 0.50; 0.75; 1.00 and 1.25 kg ha-1

  11. Determination of the new anticancer agent KW 2149, 7-N-[2-[2-(gamma-L-glutamylamino)ethyl)dithio)ethyl]mitomycin C, an analogue of mitomycin C.

    Science.gov (United States)

    Pattyn, G; van Oosterom, A T; de Bruijn, E A; Tjaden, U R

    1991-03-01

    The new mitomycin 7-N-[2-[2-(gamma-L-glutamylamino)ethyl)dithio)ethyl] mitomycin C (KW 2149) (I) proved to be active against a wide variety of experimental tumours. In order to perform pharmacokinetic studies with the new drug in Phase I sessions, a fast and reliable method has been developed based on the data of previous assays for mitomycin C. XAD-2 was preferred for isolation of I from blood plasma. The recovery of I was 50% whereas that of mitomycin C was 85%. Optimal separation was obtained on octadecyl silica columns with methanol-water (45:55, v/v) as mobile phase, while ultraviolet absorbance detection was performed at 375 nm. The assay enabled determination of I in a plasma concentration range of 20-1000 ng/ml using porfiromycin as internal standard. PMID:1860933

  12. Inhibition of Sulfide Mineral Oxidation by Surface Coating Agents: Batch

    Science.gov (United States)

    Choi, J.; Ji, M. K.; Yun, H. S.; Park, Y. T.; Gee, E. D.; Lee, W. R.; Jeon, B.-H.

    2012-04-01

    Mining activities and mineral industries have impacted on rapid oxidation of sulfide minerals such as pyrite (FeS2) which leads to Acid Mine Drainage (AMD) formation. Some of the abandoned mines discharge polluted water without proper environmental remediation treatments, largely because of financial constraints in treating AMD. Magnitude of the problem is considerable, especially in countries with a long history of mining. As metal sulfides become oxidized during mining activities, the aqueous environment becomes acid and rich in many metals, including iron, lead, mercury, arsenic and many others. The toxic heavy metals are responsible for the environmental deterioration of stream, groundwater and soils. Several strategies to remediate AMD contaminated sites have been proposed. Among the source inhibition and prevention technologies, microencapsulation (coating) has been considered as a promising technology. The encapsulation is based on inhibition of O2 diffusion by surface coating agent and is expected to control the oxidation of pyrite for a long time. Potential of several surface coating agents for preventing oxidation of metal sulfide minerals from both Young-Dong coal mine and Il-Gwang gold mine were examined by conducting batch experiments and field tests. Powdered pyrite as a standard sulfide mineral and rock samples from two mine outcrops were mixed with six coating agents (KH2PO4, MgO and KMnO4 as chemical agents, and apatite, cement and manganite as mineral agents) and incubated with oxidizing agents (H2O2 or NaClO). Batch experiments with Young-Dong coal mine samples showed least SO42- production in presence of KMnO4 (16% sulfate production compared to no surface coating agents) or cement (4%) within 8 days. In the case of Il-Gwang mine samples, least SO42- production was observed in presence of KH2PO4 (8%) or cement (2%) within 8 days. Field-scale pilot tests at Il-Gwang site also showed that addition of KH2PO4 decreased sulfate production from 200 to

  13. Synthesis, characterization, and reactivity of sulfided hexanuclear molybdenum cluster compounds

    Energy Technology Data Exchange (ETDEWEB)

    Spink, D.

    1990-09-21

    Hexanuclear molybdenum clusters with mixed chloride and sulfide bridging ligands were prepared by reacting {alpha}-MoCl{sub 2} with sodium hydrosulfide in the presence of sodium butoxide. The resulting species, Mo{sub 6}Cl{sub (8-x)}S{sub x}{center dot}npy(x {congruent} 3.6, n {congruent} 4, py = pyridine), was pyrophoric and insoluble. The mixed sulfide chloride cluster species Mo{sub 6}S{sub 4}Cl{sub 4}{center dot}6OPEt{sub 3} and Mo{sub 6}S{sub {approximately}5}Cl{sub {approximately}3}{center dot}6PEt{sub 3} and Mo{sub 6}S{sub 8}{center dot}6PEt{sub 3} were isolated and characterized. Phosphorus-31 nuclear magnetic resonance, electron paramagnetic resonance, and UV/visible spectra were obtained for each fraction. The completely sulfided cluster, Mo{sub 6}S{sub 8}{center dot}6PEt{sub 3}, was prepared similarly and used in various experiments as a possible precursor to Chevrel phase materials of the type Mo{sub 6}S{sub 8}or M{sub n}Mo{sub 6}S{sub 8}. With the goal of removing all of the triethylphosphine ligands, Mo{sub 6}S{sub 8}{center dot}6PEt{sub 3} was reacted with the transition metal carbonyls molybdenum hexacarbonyl and dicobalt octacarbonyl. Reaction on the molecular sulfide cluster with copper(I) chloride in toluene gave a completely insoluble product. The reaction of Mo{sub 6}S{sub 8}{center dot}6PEt{sub 3} with propylene sulfide gave a product whose infrared spectra showed only very weak peaks associated with coordinated triethylphosphine. The elemental analysis of this product fit the formula Mo{sub 6}S{sub 8}{center dot}5SPEt{sub 3}. Reactivity of the outer ligands of the Mo{sub 6}S{sub 8}{center dot}npy and Mo{sub 6}S{sub 8}{center dot}(6{minus}x)PrNH{sub x} clusters were investigated. Crystalline Mo{sub 6}S{sub 8}{center dot}6THT was recovered from the reaction of the n-propylamine derivative with THT. A crystal structure determination was done. 87 refs., 12 fig., 15 tabs.

  14. Ethyl Formate: A Potential Disinfestation Treatment for Eucalyptus Weevil (Gonipterus platensis) (Coleoptera: Curculionidae) in Apples.

    Science.gov (United States)

    Agarwal, Manjree; Ren, Yonglin; Newman, James; Learmonth, Stewart

    2015-12-01

    Export of Pink Lady apples from Australia has been significantly affected by infestations of adult eucalyptus weevils (Gonipterus platensis Marelli). These weevils cling tenaciously to the pedicel of apple fruit when selecting overwintering sites. As a result, apples infested with live G. platensis adults lead to rejection for export. Since the Montreal Protocol restricted use of methyl bromide as postharvest treatment, it was necessary to consider alternative safer fumigants for disinfestation of eucalyptus weevil. Laboratory experiments were conducted using concentrations of 5, 10, 15, 20, 25, 30, 40, and 80 mg/liter of ethyl formate. Complete control (100% mortality) was achieved at 25-30 mg/liter of ethyl formate at 22-24°C for 24-h exposure without apples. However, with 90-95% of the volume full of apples, complete control was achieved at 40 mg/liter of ethyl formate at 22-24°C for 24-h exposure. No phytotoxicity was observed and after one day aeration, residue of ethyl formate declined to natural levels (0.05-0.2 mg/kg). Five ethyl formate field trials were conducted in cool storages (capacity from 250-900 tons) and 100% kill of eucalyptus weevils were achieved at 50-55 mg/liter at 7-10°C for 24 h. Ethyl formate has great potential for preshipment treatment of apples. Its use is considerably cheaper and safer than already existing fumigants like methyl bromide and phosphine.

  15. Silicate sulfidation and chemical differences between enstatite chondrites and Earth

    Science.gov (United States)

    Lehner, S. W.; Petaev, M. I.; Buseck, P. R.

    2013-12-01

    Isotopic similarity between the Earth-Moon system and enstatite chondrites (ECs) led to the idea that ECs were Earth's building blocks [1-3]. However, compared to Earth's mantle, ECs have low Fe0/Fe ratios, are enriched in volatile elements, and depleted in refractory lithophile elements and Mg [4]. Therefore, deriving Earth composition from ECs requires a loss of volatiles during or prior to accretion and sequestering a large fraction of Si in the deep Earth. Alternatively, the isotopic similarity between the Earth and ECs is explained by their formation from a common precursor that experienced different evolutionary paths resulting in the chemical difference [4]. The vestiges of such a precursor are still present in the unequilibrated ECs as FeO-rich silicates with O isotopic compositions identical to bulk ECs and Earth [5]. Conversion of such a precursor into the characteristic EC mineral assemblage requires high-temperature processing in an H-poor environment with high fS2 and fO2 close to that of the classic solar nebula [6], consistent with redox conditions inferred from Ti4+/Ti3+ ratios in EC pyroxene [7]. Under such conditions reaction of FeO-rich silicates with S-rich gas results in their replacement by the assemblage of FeO-poor silicates; Fe, Mg, Ca sulfides; free silica; and Si-bearing Fe,Ni metal alloy. The progressive sulfidation of ferromagnesian silicates in chondrules results in loss of Mg and addition of Fe, Mn, S, Na, K and, perhaps, other volatiles [6]. At the advanced stages of silicate sulfidation recorded in the metal-sulfide nodules [8], a portion of Si is reduced and dissolved in the Fe,Ni metal. This process is known to fractionate Si isotopes [9,10] and would explain the differences between the ECs and Earth's mantle [11]. The sulfidation of silicates also produces porous S-rich silica, a peculiar phase observed so far only in the ECs. It consists of a sinewy SiO2-rich framework enclosing numerous vesicles filled with beam

  16. Antifoaming materials in G.S. (Girlder sulfide) heavy water plants. Thermical stability. Pt. 2

    International Nuclear Information System (INIS)

    In Girlder sulfide (G.S.) heavy water plants hydrogen sulfide-water systems are inherentely foaming, so the adding of antifoaming materials is of great importance. These may be of high volatility, pyrolizable or chemically unstable in plant operation conditions (water and hydrogen sulfide at 2 MPa, up to 230 deg C). About twenty commercial surfactants were studied from the point of view of their thermical stability. (Author)

  17. Research of the Plasma Sulfide Layer Formed on the Nitrocarburizing Layer

    Institute of Scientific and Technical Information of China (English)

    LI Xin; MA Shi-ning; HU Chun-hua; QIU Ji; HUANG Yuan-lin

    2004-01-01

    Low-temperature sulfurizing after nitrocarburizing are compared with only low-temperature sulfurizing on the surface of CrMoCu alloyed cast iron, the surface morphologies and microstructures are investigated by SEM and EDS.Results show that under proper treatment parameters, there are sulfide layer on both of the surfaces, and can more easily obtain sulfide layers on the surface of nitrocarburizing. Forming mechanism of sulfides were also studied elementarily.

  18. High Temperature Corrosion of Fe-C-S Cast Irons in Oxidizing and Sulfidizing Atmospheres

    Institute of Scientific and Technical Information of China (English)

    Thuan-Dinh NGUYEN; Dong-Bok LEE

    2008-01-01

    The corrosion behavior of spheroidal graphite and flake graphite cast irons was studied in oxidizing and sulfidizing atmospheres between 600 and 800℃ for 50 h. The corrosion rate in the sulfidizing atmosphere was faster than that in air above 700℃, due to the formation of the Feo.975S sulfide. The corrosion rate of the spheroidal graphite cast iron was similar to that of the flake graphite cast iron.

  19. Regarding "Sulfide Capacity in Ladle Slag at Steelmaking Temperatures," C. Allertz, Du Sichen; MMTB 2015 December

    Science.gov (United States)

    Pelton, Arthur; Kang, Youn-Bae

    2016-09-01

    Allertz and Sichen measured sulfide contents of slags in equilibrium with Cu-S solutions. Results are in very good agreement with calculations by FactSage whose databases were developed by modeling other sets of data obtained under different conditions. However, when results are reported as sulfide capacities, significant errors may result if these are used to calculate sulfide contents at oxygen and sulfur potentials which differ from those of the experiments and/or are fixed by different means.

  20. Self-assembly of biomorphic carbon/sulfur microstructures in sulfidic environments

    OpenAIRE

    Cosmidis, Julie; Templeton, Alexis S.

    2016-01-01

    In natural and laboratory-based environments experiencing sustained counter fluxes of sulfide and oxidants, elemental sulfur (S0)—a key intermediate in the sulfur cycle—can commonly accumulate. S0 is frequently invoked as a biomineralization product generated by enzymatic oxidation of hydrogen sulfide and polysulfides. Here we show the formation of S0 encapsulated in nanometre to micrometre-scale tubular and spherical organic structures that self-assemble in sulfide gradient environments in t...

  1. Electron Impact Induced Reactions of Ethyl Acetate and Its Sulphur Analogues

    DEFF Research Database (Denmark)

    Egsgaard, Helge; Larsen, Elfinn; Carlsen, Lars

    1983-01-01

    The electron impact induced reactions of ethyl acetate and its sulphur analogues have been studied by application of collision activation mass spectrometry and isotopic labelling with H-2 and O-18. The [M-C2H4]+·, [M-CH3]+ and [M-H2O]+· were selected for detailed investigations.......The electron impact induced reactions of ethyl acetate and its sulphur analogues have been studied by application of collision activation mass spectrometry and isotopic labelling with H-2 and O-18. The [M-C2H4]+·, [M-CH3]+ and [M-H2O]+· were selected for detailed investigations....

  2. Determination of Bioactive Components of Ethyl Acetate Fraction of Punica granatum Rind Extract

    Directory of Open Access Journals (Sweden)

    J. Sangeetha

    2011-04-01

    Full Text Available Punica granatum belongs to a Punicaceae family. The Punica granatum is valued as a powerful medicinal plant and used in folk medicines. Hence the present investigation was carried out to determine the possible chemical components from ethyl acetate fraction of Punica granatum rind extract by GC-MS Technique. This analysis revealed that ethyl acetate fraction of Punica granatum rind extract contain Pyrogallol (41.88%, 5-Hydroxymethylfurfural (14.10%, D-Allose (9.17%, 2-Methoxy-1, 4-Benzenediol (8.34% and 2, 3 Dimethylfumaric acid (3.96% justifying the use of this plant to treat many disease in folk and herbal medicine.

  3. Direct Asymmetric Aldol Type Reaction with Ethyl Diazoacetate: Stereoselective Synthesis of α, β-Dihydroxy Esters

    Institute of Scientific and Technical Information of China (English)

    LIAO Ming-Yi; YAO Wen-Gang; FENG Hai-Tao; WANG Jian-Bo

    2003-01-01

    @@ Enantioselective aldol condensation under catalytic condition remains a challenging task in modern organic synthesis, and numerous efforts have been directed to this area. In particular, the direct catalytic asymmetric aldol reaction is very attractive considering the requirement of atom efficiency. This has been studied only recently, and several very practical processes have been developed. We have recently initiated a study on the direct asymmetric aldol type reaction with ethyl diazoacetate as nucleophile. Moderate enantioselectivities (65% ~91% ee ) were achieved in the condensation of aldehydes with ethyl diazoacetate catalyzed by the chiral complex of BINOL derivatives-Zr (OBu- t )4. [1

  4. The carcinogenic potential of ethyl carbamate (urethane): risk assessment at human dietary exposure levels

    OpenAIRE

    Schlatter, J; Werner K Lutz

    2012-01-01

    Ethyl carbamate is found in fermented foods: bread contains 3-15 ng/g, stone-fruit brandies 200-20,000 ngfg, and about one-third of table-wine samples analysed contained more than 10 ng/g. In animals, ethyl carbamate is degraded to C02, H20 and NH3, with intermediate formation ofethanol. This degradation has been shown tobe inhibited (postponed) in the mouse by ethanol concentrations in the blood of about 0.15% and higher. A quantitatively minor pathway involves a two-step oxidation of the et...

  5. Layered metal laurates as active catalysts in the methyl/ethyl esterification reactions of lauric acid

    Energy Technology Data Exchange (ETDEWEB)

    Lisboa, Fabio da Silva; Cordeiro, Claudiney S.; Wypych, Fernando, E-mail: wypych@ufpr.br [Centro de Pesquisas em Quimica Aplicada (CEPESQ), Departamento de Quimica, Universidade Federal do Parana, Curitiba, PR (Brazil); Gardolinski, Jose Eduardo F. da Costa [Laboratorio de Analise de Minerais e Rochas (LAMIR), Departamento de Geologia, Universidade Federal do Parana, Curitiba, PR (Brazil)

    2012-07-01

    In this work we report the synthesis, characterization and investigation of the catalytic activity of layered copper(II), manganese(II), lanthanum(III) and nickel(II) laurates in the methyl and ethyl esterification reactions of lauric acid. In the methyl esterification, conversions between 80 and 90% were observed for all catalysts, while for the ethyl esterification only manganese laurate showed reasonable catalytic activity, with conversions close to 75%. Reuse of copper and lanthanum laurates in three cycles of reaction was also investigated and both catalysts preserved the structure and retained catalytic activity close to that observed for the first reaction cycle. (author)

  6. Cyperus difformis L. resistance to pyrazosulfuron-ethyl herbicide and option controlResistência de Cyperus difformis L. ao herbicida pyrazosulfuron-ethyl e alternativas de controle

    Directory of Open Access Journals (Sweden)

    José Alberto Noldin

    2011-08-01

    Full Text Available Cyperus difformis L. is a weed occurrence in flooded rice, that it has been presenting control difficulty due to ALS inhibiting herbicides resistance. The objectives of this work was to determine necessary rate 50% control of the population (C50 and reduce 50% of the production the aerial dry mass (GR50 in resistant and susceptible biotypes of C. difformis and evaluate the control of these biotypes with alternative herbicides recommended for that species. For that, two experiments were performed at green house of FAEM/UFPel arranged in a completely randomized design, with four replicates. The experiment I were consisted of resistant (CYPDI 9 and susceptible of C. difformis biotype and rate of the pyrazosulfuron-ethyl herbicide, corresponding to 0, 0,5, 1, 1,5, 2, 2,5, 3, 4, 6, 8, 16, 32 and 64 times de registered rate (20g ha-1. The evaluated variables were visual control and aerial dry mass (MPAS to the 28 days after the application of the treatments (DAT. In the experiment II the treatments were consisted of the same biotype (CYPDI 9 and CYPDI 8, nine herbicides azimsulfuron (6g ha-1; bentazon (900g ha-1; bispyribac-sodium (48g ha-1; carfentrazone-ethyl (40g ha-1; ethoxysulfuron (72g ha-1; glyphosate (900g ha-1; penoxsulam (36g ha-1; propanil (3600g ha-1 and pyrazosulfuron-ethyl (20g ha-1 and checks that didn't applied herbicide. The evaluated variables were: visual control for the herbicides to the 14, 21 and 28 DAT, foliate area and MPAS to 28 DAT. Before the results, it can be concluded that the resistance of the C. difformis biotype to pyrazosulfuron-ethyl is elevated and it makes unfeasible her control for the herbicide and the herbicides carfentrazone-ethyl, bentazon e propanil holders of alternative action mechanisms to the pyrazosulfuron-ethyl, control the resistant biotype of C. difformis.Cyperus difformis L. é planta daninha ocorrente em lavouras de arroz irrigado, que tem apresentado dificuldade de controle devido à resistência a

  7. Biogenic hydrogen sulfide in the oil gas of Western Siberian fields

    Energy Technology Data Exchange (ETDEWEB)

    Yershov, V.A.; Chetverkina, V.N.; Nosova, V.S.; Shakirova, A.Kh.

    1984-01-01

    In connection with the discovery of biogenic hydrogen sulfide in the oil gas of Western Siberian fields, the quantity of hydrogen sulfide has been monitored and the dynamics of the development of the sulfate reduction processes and their features are examined. It is noted that in the absence of influences on the bacterial flora, it is necessary to eliminate hydrogen sulfide from natural gas or to use hydrogen sulfide corrosion inhibiters in order to suppress biocenosis in building gas processing plants and gas lift systems, in order to reduce equipment corrosion.

  8. Microbial oxidation of soluble sulfide in produced water from the Bakkeen Sands

    Energy Technology Data Exchange (ETDEWEB)

    Gevertz, D.; Zimmerman, S. [Agouron Institute, La Jolla, CA (United States); Jenneman, G.E. [Phillips Petroleum Company, Bartlesville, OK (United States)] [and others

    1995-12-31

    The presence of soluble sulfide in produced water results in problems for the petroleum industry due to its toxicity, odor, corrosive nature, and potential for wellbore plugging. Sulfide oxidation by indigenous nitrate-reducing bacteria (NRB) present in brine collected from wells at the Coleville Unit (CVU) in Saskatchewan, Canada, was investigated. Sulfide oxidation took place readily when nitrate and phosphate were added to brine enrichment cultures, resulting in a decrease in sulfide levels of 99-165 ppm to nondetectable levels (< 3.3 ppm). Produced water collected from a number of producing wells was screened to determine the time required for complete sulfide oxidation, in order to select candidate wells for treatment. Three wells were chosen, based on sulfide removal in 48 hours or less. These wells were treated down the backside of the annulus with a solution containing 10 mM KNO{sub 3} and 100 {mu}M NaH{sub 2}PO{sub 4}. Following a 24- to 72-hour shut-in, reductions in pretreatment sulfide levels of greater than 90% were observed for two of the wells, as well as sustained sulfide reductions of 50% for at least two days following startup. NRB populations in the produced brine were observed to increase significantly following treatment, but no significant increases in sulfate-reducing bacteria were observed. These results demonstrate the technical feasibility of stimulating indigenous populations of NRB to remediate and control sulfide in produced brine.

  9. Spectral induced polarization and electrodic potential monitoring of microbially mediated iron sulfide transformations

    Energy Technology Data Exchange (ETDEWEB)

    Hubbard, Susan; Personna, Y.R.; Ntarlagiannis, D.; Slater, L.; Yee, N.; O' Brien, M.; Hubbard, S.

    2008-02-15

    Stimulated sulfate-reduction is a bioremediation technique utilized for the sequestration of heavy metals in the subsurface.We performed laboratory column experiments to investigate the geoelectrical response of iron sulfide transformations by Desulfo vibriovulgaris. Two geoelectrical methods, (1) spectral induced polarization (SIP), and (2) electrodic potential measurements, were investigated. Aqueous geochemistry (sulfate, lactate, sulfide, and acetate), observations of precipitates (identified from electron microscopy as iron sulfide), and electrodic potentials on bisulfide ion (HS) sensitive silver-silver chloride (Ag-AgCl) electrodes (630 mV) were diagnostic of induced transitions between an aerobic iron sulfide forming conditions and aerobic conditions promoting iron sulfide dissolution. The SIP data showed 10m rad anomalies during iron sulfide mineralization accompanying microbial activity under an anaerobic transition. These anomalies disappeared during iron sulfide dissolution under the subsequent aerobic transition. SIP model parameters based on a Cole-Cole relaxation model of the polarization at the mineral-fluid interface were converted to (1) estimated biomineral surface area to pore volume (Sp), and (2) an equivalent polarizable sphere diameter (d) controlling the relaxation time. The temporal variation in these model parameters is consistent with filling and emptying of pores by iron sulfide biofilms, as the system transitions between anaerobic (pore filling) and aerobic (pore emptying) conditions. The results suggest that combined SIP and electrodic potential measurements might be used to monitor spatiotemporal variability in microbial iron sulfide transformations in the field.

  10. Formation of Iron Sulfide in Water-Body Sediment and Its Influence on Environment

    Institute of Scientific and Technical Information of China (English)

    YAN Lei; SUMI Katsuhiro

    2008-01-01

    Iron sulfide is an important reductive pollutant in aquatic sediment, so that increasing attentions have been paid to it in recent years. In this paper, the formation of iron sulfide in water-body sediment was introduced. Moreover, its adverse influences upon environment were summarized, including direct contribution to deficiency of dissolved oxygen in water, association with eutrophication in water-bodies and impact on geochemical sulfur cycle. Since conventional chemical analysis for iron sulfide has several disadvantages, new technique for rapid determination of iron sulfide on-line was prospected.

  11. The Terminal Oxidase Cytochrome bd Promotes Sulfide-resistant Bacterial Respiration and Growth.

    Science.gov (United States)

    Forte, Elena; Borisov, Vitaliy B; Falabella, Micol; Colaço, Henrique G; Tinajero-Trejo, Mariana; Poole, Robert K; Vicente, João B; Sarti, Paolo; Giuffrè, Alessandro

    2016-01-01

    Hydrogen sulfide (H2S) impairs mitochondrial respiration by potently inhibiting the heme-copper cytochrome c oxidase. Since many prokaryotes, including Escherichia (E.) coli, generate H2S and encounter high H2S levels particularly in the human gut, herein we tested whether bacteria can sustain sulfide-resistant O2-dependent respiration. E. coli has three respiratory oxidases, the cyanide-sensitive heme-copper bo3 enzyme and two bd oxidases much less sensitive to cyanide. Working on the isolated enzymes, we found that, whereas the bo3 oxidase is inhibited by sulfide with half-maximal inhibitory concentration IC50 = 1.1 ± 0.1 μM, under identical experimental conditions both bd oxidases are insensitive to sulfide up to 58 μM. In E. coli respiratory mutants, both O2-consumption and aerobic growth proved to be severely impaired by sulfide when respiration was sustained by the bo3 oxidase alone, but unaffected by ≤200 μM sulfide when either bd enzyme acted as the only terminal oxidase. Accordingly, wild-type E. coli showed sulfide-insensitive respiration and growth under conditions favouring the expression of bd oxidases. In all tested conditions, cyanide mimicked the functional effect of sulfide on bacterial respiration. We conclude that bd oxidases promote sulfide-resistant O2-consumption and growth in E. coli and possibly other bacteria. The impact of this discovery is discussed. PMID:27030302

  12. XAFS characterization of industrial catalysts: in situ study of phase transformation of nickel sulfide

    Science.gov (United States)

    Wang, J.; Jia, Z.; Wang, Q.; Zhao, S.; Xu, Z.; Yang, W.; Frenkel, A. I.

    2016-05-01

    The online sulfiding process for nickel-contained catalyst often ends up with a nickel sulfide mixture in refinery plant. To elucidate the local environment of nickel and its corresponding sulfur species, a model catalyst (nickel sulfide) and model thermal process were employed to explore the possibilities for characterization of real catalysts in industrial conditions. The present investigation shows effectiveness of in situ XANES and EXAFS measurements for studying the phase stability and phase composition in these systems, which could be used to simulate real sulfiding process in industrial reactions, such as hydrodesulfurizations of oil.

  13. Enhanced performance of denitrifying sulfide removal process under micro-aerobic condition

    International Nuclear Information System (INIS)

    The denitrifying sulfide removal (DSR) process with bio-granules comprising both heterotrophic and autotrophic denitrifiers can simultaneously convert nitrate, sulfide and acetate into di-nitrogen gas, elementary sulfur and carbon dioxide, respectively, at high loading rates. This study determines the reaction rate of sulfide oxidized into sulfur, as well as the reduction of nitrate to nitrite, would be enhanced under a micro-aerobic condition. The presence of limited oxygen mitigated the inhibition effects of sulfide on denitrifier activities, and enhanced the performance of DSR granules. The advantages and disadvantages of applying the micro-aerobic condition to the DSR process are discussed.

  14. Sulfur speciation and sulfide oxidation in the water column of the Black Sea

    Science.gov (United States)

    Luther, George W., III; Church, Thomas M.; Powell, David

    We have applied sulfur speciation techniques to understand the chemistry and cycling of sulfur in Black Sea waters. The only reduced dissolved inorganic sulfur species detected (above the low minimum detection limits of the voltammetric methods employed) in the water column was hydrogen sulfide. The maximum concentration of sulfide (423 μM) is similar to previous reports. Using a cathodic stripping square wave voltammetry (CSSWV) method for nanomolar levels of sulfide, we determined the precise boundary between the "free" hydrogen sulfide (sulfidic) zone and the upper (oxic/suboxic) water column at the two stations studied. This boundary has apparently moved up by about 50 m in the past 20 years. Our results help demonstrate three chemically distinct zones of water in the central basin of the Black Sea: (1) the oxic [0-65 m], (2) the anoxic/nonsulfidic [65-100 m] and (3) the sulfidic [>100 m]. Sulfide bound to metals ("complexed" sulfide) is observed in both the oxic and anoxic/nonsulfidic zones of the water column. This supports previous studies on metal sulfide forms. From the electrochemical data, it is possible to estimate the strength of the complexation of sulfide to metals (log K = 10 to 11). Thiosulfate and sulfite were below our minimum detectable limit (MDL) of 50 nM using CSSWV. Elemental sulfur (MDL 5 nM) was detected below the onset of the hydrogen sulfide zone (90-100 m) with a maximum of 30-60 nM near 120 m. The sulfur speciation results for the Black Sea are lower by one order of magnitude or more than other marine systems such as the Cariaco Trench and salt marshes. New HPLC techniques were applied to detect thiols at submicromolar levels. The presence of thiols (2-mercaptoethylamine, 2-mercaptoethanol, N-acetylcysteine and glutathione) is correlated with the remineralization of organic matter at the oxic and anoxic/nonsulfidic interface. Water samples collected from the upper 50 m of the sulfidic zone showed significant sulfide oxidation on

  15. Pd-NHC-Catalyzed Alkynylation of General Aryl Sulfides with Alkynyl Grignard Reagents.

    Science.gov (United States)

    Baralle, Alexandre; Yorimitsu, Hideki; Osuka, Atsuhiro

    2016-07-25

    Cross-coupling reactions of unactivated aryl sulfides with alkynylmagnesium chloride have been invented to afford 1-aryl-1-alkynes with the aid of a palladium/N-heterocyclic carbene complex. This reaction has by far the widest scope of all transformations utilizing aryl sulfides and alkynes, while known cross-coupling alkynylations of aryl-sulfur electrophiles require activated azaaryl sulfides, thiolactams, or arenesulfonyl chlorides. The alkynylation of aryl sulfides is compatible with typical protecting functional groups. The alkynylation is applied to the synthesis of benzofuran-based fluorescent molecules by taking advantage of characteristic organosulfur chemistry.

  16. Microbial community dynamics during the bioremediation process of chlorimuron-ethyl-contaminated soil by Hansschlegelia sp. strain CHL1.

    Science.gov (United States)

    Yang, Liqiang; Li, Xinyu; Li, Xu; Su, Zhencheng; Zhang, Chenggang; Zhang, Huiwen

    2015-01-01

    Long-term and excessive application of chlorimuron-ethyl has led to a series of environmental problems. Strain Hansschlegelia sp. CHL1, a highly efficient chlorimuron-ethyl degrading bacterium isolated in our previous study, was employed in the current soil bioremediation study. The residues of chlorimuron-ethyl in soils were detected, and the changes of soil microbial communities were investigated by phospholipid fatty acid (PLFA) analysis. The results showed that strain CHL1 exhibited significant chlorimuron-ethyl degradation ability at wide range of concentrations between 10μg kg-1 and 1000μg kg-1. High concentrations of chlorimuron-ethyl significantly decreased the total concentration of PLFAs and the Shannon-Wiener indices and increased the stress level of microbes in soils. The inoculation with strain CHL1, however, reduced the inhibition on soil microbes caused by chlorimuron-ethyl. The results demonstrated that strain CHL1 is effective in the remediation of chlorimuron-ethyl-contaminated soil, and has the potential to remediate chlorimuron-ethyl contaminated soils in situ.

  17. Synthesis of Comblike Poly(methyl methacrylate) by Atom Transfer Radical Polymerization with Poly(ethyl 2-bromoacrylate) as Macroinitiator

    Institute of Scientific and Technical Information of China (English)

    Yan SHI; Zhi Feng FU; Yu Dong ZHANG; Shu Ke JIAO

    2003-01-01

    Comblike poly(methyl methacrylate) was synthesized by atom transfer radical polymerization of methyl methacrylate with poly(ethyl 2-bromoacrylate) as a macroinitiator, which was prepared by conventional free radical polymerization of ethyl 2-bromoacrylate. The obtained comblike polymers were characterized by GPC and 1H NMR.

  18. Synthesis of 10-Ethyl Flavin: A Multistep Synthesis Organic Chemistry Laboratory Experiment for Upper-Division Undergraduate Students

    Science.gov (United States)

    Sichula, Vincent A.

    2015-01-01

    A multistep synthesis of 10-ethyl flavin was developed as an organic chemistry laboratory experiment for upper-division undergraduate students. Students synthesize 10-ethyl flavin as a bright yellow solid via a five-step sequence. The experiment introduces students to various hands-on experimental organic synthetic techniques, such as column…

  19. Extremely decreased release of prostaglandin E-like activity from chopped lung of ethyl linolenate-supplemented rats

    DEFF Research Database (Denmark)

    Hansen, Harald S.; Jensen, B.; Fjalland, B.

    1983-01-01

    Three groups of weanling male rats were reared on a fat-free diet for 13 weeks. One group received only the fat-free diet (FF rats), the other 2 groups received the fat-free diet and a daily supplement of 2 energy% ethyl linoleate ([n-6] rats), or 2 energy% ethyl linolenate ([n-3] rats). The...

  20. Microbial community dynamics during the bioremediation process of chlorimuron-ethyl-contaminated soil by Hansschlegelia sp. strain CHL1.

    Directory of Open Access Journals (Sweden)

    Liqiang Yang

    Full Text Available Long-term and excessive application of chlorimuron-ethyl has led to a series of environmental problems. Strain Hansschlegelia sp. CHL1, a highly efficient chlorimuron-ethyl degrading bacterium isolated in our previous study, was employed in the current soil bioremediation study. The residues of chlorimuron-ethyl in soils were detected, and the changes of soil microbial communities were investigated by phospholipid fatty acid (PLFA analysis. The results showed that strain CHL1 exhibited significant chlorimuron-ethyl degradation ability at wide range of concentrations between 10μg kg-1 and 1000μg kg-1. High concentrations of chlorimuron-ethyl significantly decreased the total concentration of PLFAs and the Shannon-Wiener indices and increased the stress level of microbes in soils. The inoculation with strain CHL1, however, reduced the inhibition on soil microbes caused by chlorimuron-ethyl. The results demonstrated that strain CHL1 is effective in the remediation of chlorimuron-ethyl-contaminated soil, and has the potential to remediate chlorimuron-ethyl contaminated soils in situ.

  1. 21 CFR 172.225 - Methyl and ethyl esters of fatty acids produced from edible fats and oils.

    Science.gov (United States)

    2010-04-01

    ... from edible fats and oils. 172.225 Section 172.225 Food and Drugs FOOD AND DRUG ADMINISTRATION... Methyl and ethyl esters of fatty acids produced from edible fats and oils. Methyl esters and ethyl esters of fatty acids produced from edible fats and oils may be safely used in food, subject to...

  2. In Situ Gene Expression Responsible for Sulfide Oxidation and CO2 Fixation of an Uncultured Large Sausage-Shaped Aquificae Bacterium in a Sulfidic Hot Spring.

    Science.gov (United States)

    Tamazawa, Satoshi; Yamamoto, Kyosuke; Takasaki, Kazuto; Mitani, Yasuo; Hanada, Satoshi; Kamagata, Yoichi; Tamaki, Hideyuki

    2016-06-25

    We investigated the in situ gene expression profile of sulfur-turf microbial mats dominated by an uncultured large sausage-shaped Aquificae bacterium, a key metabolic player in sulfur-turfs in sulfidic hot springs. A reverse transcription-PCR analysis revealed that the genes responsible for sulfide, sulfite, and thiosulfate oxidation and carbon fixation via the reductive TCA cycle were continuously expressed in sulfur-turf mats taken at different sampling points, seasons, and years. These results suggest that the uncultured large sausage-shaped bacterium has the ability to grow chemolithoautotrophically and plays key roles as a primary producer in the sulfidic hot spring ecosystem in situ.

  3. In Situ Gene Expression Responsible for Sulfide Oxidation and CO2 Fixation of an Uncultured Large Sausage-Shaped Aquificae Bacterium in a Sulfidic Hot Spring.

    Science.gov (United States)

    Tamazawa, Satoshi; Yamamoto, Kyosuke; Takasaki, Kazuto; Mitani, Yasuo; Hanada, Satoshi; Kamagata, Yoichi; Tamaki, Hideyuki

    2016-06-25

    We investigated the in situ gene expression profile of sulfur-turf microbial mats dominated by an uncultured large sausage-shaped Aquificae bacterium, a key metabolic player in sulfur-turfs in sulfidic hot springs. A reverse transcription-PCR analysis revealed that the genes responsible for sulfide, sulfite, and thiosulfate oxidation and carbon fixation via the reductive TCA cycle were continuously expressed in sulfur-turf mats taken at different sampling points, seasons, and years. These results suggest that the uncultured large sausage-shaped bacterium has the ability to grow chemolithoautotrophically and plays key roles as a primary producer in the sulfidic hot spring ecosystem in situ. PMID:27297893

  4. Wound healing properties of ethyl acetate fraction of Moringa oleifera in normal human dermal fibroblasts

    Directory of Open Access Journals (Sweden)

    Sivapragasam Gothai

    2016-03-01

    Full Text Available Background/Aim: Wounds are the outcome of injuries to the skin that interrupt the soft tissue. Healing of a wound is a complex and long-drawn-out process of tissue repair and remodeling in response to injury. A large number of plants are used by folklore traditions for treatment of cuts, wounds and burns. Moringa oleifera is an herb used as traditional folk medicine for the treatment of various skin wounds and associated diseases. The underlying mechanisms of wound healing activity of ethyl acetate fraction of M. oleifera leaves extract are completely unknown. Methods: In the current study, ethyl acetate fraction of Moringa oleifera leaves was investigated for its efficacy on cell viability, proliferation and migration (wound closure rate in human normal dermal fibroblast cells. Results: Results revealed that lower concentration (12.5 and micro;g/ml, 25 and micro;g/ml, and 50 and micro;g/ml of ethyl acetate fraction of M. oleifera leaves showed remarkable proliferative and migratory effect on normal human dermal fibroblasts. Conclusion: The present study suggested that ethyl acetate fraction of M. oleifera leaves might be a potential therapeutic agent for skin wound healing by promoting fibroblast proliferation and migration through increasing the wound closure rate corroborating its traditional use. [J Intercult Ethnopharmacol 2016; 5(1.000: 1-6

  5. N-acetylcysteine and hemodialysis treatment of a severe case of methyl ethyl ketone peroxide intoxication

    NARCIS (Netherlands)

    van Enckevort, C C G; Touw, D J; Vleming, L-J

    2008-01-01

    The plastic hardener methyl ethyl ketone peroxide (MEKP) is an unstable peroxide that releases free oxygen radicals. Ingestion of this compound induces widespread liver necrosis that is often fatal, extensive ulceration with subsequent scarring, and stenosis of the proximal digestive tract in surviv

  6. Mutation frequencies in ontogenetically different spikes of hexaploid wheat after ethyl methanesulphonate treatment

    DEFF Research Database (Denmark)

    Iqbal Khan, M.; Doll, Hans

    1968-01-01

    Seeds of hexaploid wheat were treated with ethyl methanesulphonate (EMS). The M1 generation was grown in a greenhouse, and the individual shoots of the plants were classified and marked according to their ontogeny. The sterility in M1 and the frequencies of chlorophyll and viable mutants segregat...

  7. Catalytic Combustion of Ethyl Acetate over Nanostructure Cobalt Supported ZSM-5 Zeolite Catalysts

    Institute of Scientific and Technical Information of China (English)

    NIAEI,Aligholi; SALARI,Dariush; HOSSEINI,Seyed Ali; KHATAMIAN,Masumeh; JODAEL,Azadeh

    2009-01-01

    Gas phase catalytic combustion of ethyl acetate,as one of volatile organic compounds(VOC),was studied on nanostructure ZSM-5.HZSM-5 and Co-ZSM-5 with different cobalt loadings. Nanostructure of ZSM-5 Was deter-mined by XRD,SEM and TEM. Catalytic studies were carried out under atmospheric pressure in a fixed bed reactor.Results showed that the Co-ZSM-5 catalysts had better activity than others and at temperatures below 350℃.amount of Co loading was mole effective on catalytic activity.The order of conversion of ethyl acetate over differ-ent Co loading is as follows:Co-ZSM-5(0.75 wt%)ethyl acetate,the lower the conversion yield,and oxygen concentration in catalytic oxidation conditions has not so large influence on conversion. Furthermore,the presence of water vapor in inlet gaseous feed has an inhibitive effect on ethyl acetate conversion and at the temperatures above 400℃,the effect decreases.

  8. Liver damage caused by hepatitis C viral infection and ethyl alcohol consumption

    Directory of Open Access Journals (Sweden)

    Kostić Velimir

    2006-01-01

    Full Text Available Background/Aim. Hepatitis C virus infection (HCV is a complex disease, most commonly chronicle (80-85%. The aim of this research was to determinate the level of the liver damage in the patients cansed by HCV in conjunction with consuming ethyl alcohol. Methods. The research included 15 patients with chronic HCV infection supported by the misuse of ethyl alcohol, as well. The diagnosis of C infection hepatitis was proved using the ELISA test and PCR method. Results. The results of the study showed the liver damage by both HCV infection and ethyl alcohol, which was verified by the presence of biochemical changes and patohystological processing of the patients (liver biopsy and prosection. Patohystological changes were at the level of liver cirrhosis and carcinoma (2 patients. There was a signficant difference between the two subgroups (p < 0.001 regarding the examined values γ-GT, PLT and PTV. The basic therapeutic procedure was to introduce this category of patients into alcohol abstinence, and, in a few patients, to apply the antivirus therapy, as well. Conclusion. Based on the number of the examined patients (n = 15, we could conclude that a prolonged ethyl alcohol misuse with the presence of HCV infection was in a correlation with the liver disease progression.

  9. Distribution and Organoleptic Impact of Ethyl 3-Hydroxybutanoate Enantiomers in Wine.

    Science.gov (United States)

    Lytra, Georgia; Cameleyre, Margaux; Tempere, Sophie; Barbe, Jean-Christophe

    2015-12-01

    Enantiomers of ethyl 3-hydroxybutanoate were assayed in 87 commercial wines from various vintages and origins, using chiral gas chromatography (β-cyclodextrin). Generally, ethyl 3-hydroxybutanoate levels were higher in red than in white wines of the same age. The average S/R enantiomeric ratio of this compound in red wine was approximately 75:25 (± 13), with an average total concentration of ∼ 450 (± 150) μg/L. In red wines, R-form levels increased gradually during aging, but no variations were observed in S-form concentrations. To our knowledge, no previous research had determined the enantiomeric distribution of this compound in wine. The olfactory threshold of the S-form in dilute alcohol solution was 21 mg/L, one-third that of the R-form: 63 mg/L. The S- and R-forms had different aromatic nuances. The olfactory threshold of their mixture (85:15, m/m) was 14 mg/L, indicating a simple additive effect in this binary mixture. Furthermore, the concentrations found in red wines were considerably below the olfactory threshold under the same experimental conditions. Sensory analysis revealed that ethyl 3-hydroxybutanoate (S/R, 85:15, m/m) had an enhancing effect on the perception of fruity aromas in the matrices studied. Sensory profiles highlighted the contribution of ethyl 3-hydroxybutanoate to red-berry and fresh-fruit descriptors, despite its subthreshold concentrations.

  10. Optimization of coproduction of ethyl acetate and n-butyl acetate by reactive distillation☆

    Institute of Scientific and Technical Information of China (English)

    Hui Tian; Suying Zhao; Huidong Zheng; Zhixian Huang

    2015-01-01

    Based on a previous investigation, a simulation model was used for optimization of coproduction of ethyl acetate and n-butyl acetate by reactive distil ation. An experimental setup was established to verify the simulated results. The effects of various operating variables, such as ethanol feed location, acetic acid feed location, feed stage of reaction mixture of acetic acid and n-butanol, reflux ratio of ethyl acetate reactive distillation column, and distil-late to feed ratio of n-butyl acetate column, on the ethanol/n-butanol conversions, ethyl acetate/n-butyl acetate purity, and energy consumption were investigated. The optimal results in the simulation study are as follows:ethanol feed location, 15th stage;acetic acid feed location, eighth stage;feed location of reaction mixture of acetic acid and n-butanol, eighth stage;reflux ratio of ethyl acetate reactive distillation column, 2.0;and distillate to feed ratio of n-butyl acetate, 0.6.

  11. Phytochemical screening and anticonvulsant studies of ethyl acetate fraction of Globimetula braunii on laboratory animals

    Directory of Open Access Journals (Sweden)

    Musa Mumammad Aliyu

    2014-04-01

    Conclusions: These results suggest that the ethyl acetate fraction of Globimetula braunii leaves extract possesses psychoactive compound that may be useful in the management of petit mal epilepsy and lend credence to the ethnomedical use of the plant in the management of epilepsy.

  12. Synthesis and Purification of Porphyrin-Schiff Base Using Ethyl Vanillin

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A novel porphyrin-Schiff base was synthesized via the condensation of 5-(4-aminophenyl)-10,15,20-triphenylporphyrin and ethyl vanillin. After analyzing the level of purification of the porphyrin-Schiff base, it was successfully separated. This porphyrin-Schiff base was characterized by using UV-Vis, IR, 1 H NMR and MS spectroscopy.

  13. Evaluation of ethyl N-(2-phenethyl) carbamate analogues as biofilm inhibitors of methicillin resistant Staphylococcus aureus.

    Science.gov (United States)

    Stephens, Matthew D; Yodsanit, Nisakorn; Melander, Christian

    2016-07-12

    A small molecule library consisting of 45 compounds was synthesized based on the bacterial metabolite ethyl N-(2-phenethyl) carbamate. Screening of the compounds revealed a potent analogue capabale of inhibiting several strains of Methicillin Resistant S. aureus biofilms with low to moderate micromolar IC50 values. PMID:27341658

  14. Ethyl benzene-induced ototoxicity in rats : a dose-dependent mild-frequency hearing loss

    NARCIS (Netherlands)

    Cappaert, N.L.M.; Klis, S.F.L.; Baretta, A.B.; Muijser, H.; Smoorenburg, G.F.

    2000-01-01

    Rats were exposed to ethyl benzene at 0, 300, 400 and 550 ppm for 8 hours/day for 5 consecutive days. Three to six weeks after the exposure, auditory function was tested by measuring compound action potentials (CAP) in the frequency range of 1-24 kHz and 2f1-f2 distortion product otoacoustic emissio

  15. Cosolvent Effect on the Tautomerism of Ethyl Acetoacetate in Supercritical CO2

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The effect of cosolvent cyclohexane, chloroform, and acetonitrile on the keto-enol tautomeric equilibrium of ethyl acetoacetate in supercritical CO2 was studied by UV-Vis spectroscopy over the pressure range from 76 to 110 bar at 308.15 K. It was found that the equilibrium constant decreases with increasing polarity of the cosolvents.

  16. Cytotoxic activities of ethyl acetate extract and a metabolite from a Monocillium species.

    Science.gov (United States)

    Khondkar, Proma; Rahman, M Mukhlesur; Islam, Anwarul

    2005-09-01

    The ethyl acetate soluble fraction of a cultural broth of a Monocillium species afforded the isolation of 5-hydroxymethylfurfural. Both the extract and 5-hydroxymethylfurfural showed significant cytotoxic activities in a brine shrimp bioassay and the LC(50) values were found to be 14.96 microg/mL and 23.71 microg/mL, respectively. PMID:16220580

  17. 78 FR 9938 - Ethyl Alcohol for Fuel Use: Determination of the Base Quantity of Imports

    Science.gov (United States)

    2013-02-12

    ... recent previous determination for the 2012 amount in the Federal Register on December 30, 2011 (76 FR... COMMISSION Ethyl Alcohol for Fuel Use: Determination of the Base Quantity of Imports AGENCY: United States.... Section 423(c) of the Tax Reform Act of 1986 (``the Act''), as amended (19 U.S.C. 2703 note), required...

  18. Thermodynamic properties of 1-ethyl-4-nitro-1,2,3-triazole

    Energy Technology Data Exchange (ETDEWEB)

    Blokhin, Andrey V., E-mail: blokhin@bsu.by; Kohut, Sviataslau V.; Kabo, Gennady J.; Stepurko, Elena N.; Paulechka, Yauheni U.; Voitkevich, Olga V.

    2013-08-10

    Graphical abstract: - Highlights: • Heat capacities and phase transition enthalpies for 1-ethyl-4-nitro-1,2,3-triazole were measured. • Enthalpy of formation for 1-ethyl-4-nitro-1,2,3-triazole was determined. • Vapor pressure and enthalpy of sublimation of 1-ethyl-4-nitro-1,2,3-triazole were found from Knudsen measurements. - Abstract: Temperature dependence of the heat capacity and the parameters of phase transitions of 1-ethyl-4-nitro-1,2,3-triazole (1ET) were studied between 5 and 370 K in a vacuum adiabatic calorimeter. Thermodynamic properties of the 1ET in the condensed state were obtained over the range of 0–370 K. Saturated vapor pressure for crystalline 1ET in the temperature ranges from 313 to 344 K and its enthalpy of sublimation were measured by the Knudsen effusion method. The standard enthalpy of formation for crystalline 1ET at 298.15 K was determined in a static bomb combustion calorimeter. From these data, the standard enthalpy of formation for gaseous 1ET was evaluated. The enthalpy of formation calculated using quantum chemical methods is in excellent agreement with the experimental value.

  19. Comparative Study Between Ethylbenzene Disproportionation Reaction and its Ethylation Reaction with Ethanol over ZSM-5

    KAUST Repository

    Tukur, N. M.

    2009-06-23

    Ethylation of ethylbenzene with ethanol has been studied over ZSM-5 catalyst in a riser simulator that mimics the operation of a fluidized-bed reactor. The feed molar ratio of ethylbenzene:ethanol is 1:1. The study was carried out at 350, 400, 450, and 500°C for reaction times of 3, 5, 7, 10, 13, and 15 s. Comparisons are made between the results of the ethylbenzene ethylation reaction with that of ethylbenzene disproportionation reaction earlier reported. The effect of reaction conditions on ethylbenzene reactivity, p-diethylbenzene selectivity, total diethylbenzene (DEB) isomers selectivity, p-DEB-to-m-DEB ratio, benzene-to-DEB molar ratio, and benzene selectivity, are reported. Benzene selectivity is about 10 times more in the EB disproportion reaction as compared to its ethylation reaction with ethanol at 350°C. In addition, the results showed a p-DEB/m-DEB ratio for the EB ethylation reaction varying between 1.2-1.7, which is greater than the equilibrium values. Increase in temperature shifts the alkylation/dealkylation equilibrium towards dealkylation, thereby decreasing conversion and selectivity to DEB. © Springer Science+Business Media, LLC 2009.

  20. Primary study of ethyl cellulose nanofiber for oxygen-enrichment membrane

    Directory of Open Access Journals (Sweden)

    Shen Jing

    2016-01-01

    Full Text Available Ethyl cellulose is widely used for oxygen-enrichment membrane, however, its nanofiber membrane was rarely developed though it behaves more excellent performance. This paper gives a preliminary study to produce oxygen-enrichment membrane by bubbfil spinning.

  1. ENZYMATIC PRODUCTION OF ETHYL OLEATE ESTER USING A LIPASE FROM CANDIDA ANTARCTICA B

    Directory of Open Access Journals (Sweden)

    N. Sampaio Neta

    2012-05-01

    Full Text Available Lipases are biocatalysts of great importance in different areas, being able to catalyze reactions in aqueous or organic media. Furthermore, these enzymes are capable of using several substrates being stable in a wide range of pH and temperatures. Lipases promote the esterification between fatty acids and ethanol producing oleate esters. The aim of this work is to produce ethyl oleate ester by enzymatic esterification of oleic acid with ethanol. A lipase from Candida antarctica type B was used at a temperature of 55 °C. The reaction was conducted using oleic acid, sodium sulfate anhydrous, lipase and ethanol, with a ratio of oleic acid (0.03 mol or 10 ml, lipase (0.1 mol or 0.01 g, sodium sulfate anhydrous (5 g and ethanol 99 % (100 ml. Several reaction times were studied, namely 48, 72, 96 and 120 hours. Nuclear Magnetic Resonance (1H and 13C and Infrared spectra confirmed the production of ethyl oleate ester for the studied conditions. The highest ethyl oleate production yield was obtained for 96 hours reaction time. Ethyl oleate esters have been reported to possess interesting applications in several industrial fields, such as food, aromatics, cosmetics, detergents, flavors and pharmaceuticals.

  2. Adsorption-desorption behaviour of chlorimuron-ethyl herbicide on homoionic clays

    Directory of Open Access Journals (Sweden)

    Archana Suyal

    2013-01-01

    Full Text Available Laboratory studies were conducted to determine the adsorption-desorption behaviour of Chlorimuron-ethyl herbicide on three homoionic clays (Kaolinite (K, Mica (M and Bentonite (B, which are found in Indian soils. The adsorption- desorption data of chlorimuron-ethyl fitted well to Freundlich adsorption- desorption isotherm model (R² = 0.755 to 0.986. The computed valued of log K and 1/n varied from 4.0199 (B-Cu to 4.1144 (B-Ca and from 0.4458 (M-Cu to 0.7894 (K-Ca respectively. Desorption data of chlorimuron-ethyl were also fitted to Freundlich model and the values of log K' and 1/n' ranged from 4.2727 (K-Ca to 4.2933 (M-Ca and from 0.0006 (B-Cu to 0.0033 (B-Ca, respectively. Higher values of desorption index n'/n indicated poor reversibility of chlorimuron ethyl by soil clays.

  3. Effect of ethyl silicate on salt crystallization resistance of Maastricht limestone

    NARCIS (Netherlands)

    Lubelli, B.A.; Hees, R.P.J.; Nijland, T.G.; Bolhuis, J.

    2014-01-01

    consolidant treatments aim to re-establish the cohesion in declayed materials showing decqay patterns as sanding or powdering. Ethyl silicate (TEOS) is the most used type of consolidant for inorganic porous materials in the last 30 years. This product which works through precipitation of silica gel

  4. (2E-2-Benzylidene-4-ethyl-3,4-dihydronaphthalen-1(2H-one

    Directory of Open Access Journals (Sweden)

    Mohamed Akhazzane

    2011-07-01

    Full Text Available In the title compound, C19H18O, the exocyclic C=C double bond has an E configuration. The ethyl substituent on the cyclohexanone ring is in an axial position. The cyclohexanone ring adopts a half-chair conformation, presumably due to conjugation in the benzene ring.

  5. Venous cannulation and topical ethyl chloride in patients receiving nitrous oxide.

    Science.gov (United States)

    Crecelius, C.; Rouhfar, L.; Beirne, O. R.

    1999-01-01

    The purpose of this study was to evaluate the effect of ethyl chloride spray on the anxiety and pain associated with placing an intravenous catheter in patients sedated with nitrous oxide. Eighty-eight patients scheduled for dental surgery with a combination of intravenous and nitrous oxide sedation were randomly assigned to have ethyl chloride spray or a placebo, water spray, applied before cannulation of a vein. Anxiety and pain were reported using a 10.0-cm visual analog scale before nitrous oxide administration, after nitrous oxide sedation, following application of the spray, and following venous cannulation. The first 2 assessments measured overall levels of patient anxiety and pain and confirmed that nitrous oxide sedation reduced anxiety without changing already low levels of pain. The second 2 assessments of anxiety and pain measured the reaction toward the spray and cannulation. The application of ethyl chloride spray produced significantly more anxiety and pain than did the placebo. The results of this study demonstrate that ethyl chloride spray does not significantly reduce the anxiety and pain associated with venous cannulation in patients sedated with nitrous oxide. PMID:11692346

  6. Sulfide-driven arsenic mobilization from arsenopyrite and black shale pyrite

    Science.gov (United States)

    Zhu, W.; Young, L.Y.; Yee, N.; Serfes, M.; Rhine, E.D.; Reinfelder, J.R.

    2008-01-01

    We examined the hypothesis that sulfide drives arsenic mobilization from pyritic black shale by a sulfide-arsenide exchange and oxidation reaction in which sulfide replaces arsenic in arsenopyrite forming pyrite, and arsenide (As-1) is concurrently oxidized to soluble arsenite (As+3). This hypothesis was tested in a series of sulfide-arsenide exchange experiments with arsenopyrite (FeAsS), homogenized black shale from the Newark Basin (Lockatong formation), and pyrite isolated from Newark Basin black shale incubated under oxic (21% O2), hypoxic (2% O2, 98% N2), and anoxic (5% H2, 95% N2) conditions. The oxidation state of arsenic in Newark Basin black shale pyrite was determined using X-ray absorption-near edge structure spectroscopy (XANES). Incubation results show that sulfide (1 mM initial concentration) increases arsenic mobilization to the dissolved phase from all three solids under oxic and hypoxic, but not anoxic conditions. Indeed under oxic and hypoxic conditions, the presence of sulfide resulted in the mobilization in 48 h of 13-16 times more arsenic from arsenopyrite and 6-11 times more arsenic from isolated black shale pyrite than in sulfide-free controls. XANES results show that arsenic in Newark Basin black shale pyrite has the same oxidation state as that in FeAsS (-1) and thus extend the sulfide-arsenide exchange mechanism of arsenic mobilization to sedimentary rock, black shale pyrite. Biologically active incubations of whole black shale and its resident microorganisms under sulfate reducing conditions resulted in sevenfold higher mobilization of soluble arsenic than sterile controls. Taken together, our results indicate that sulfide-driven arsenic mobilization would be most important under conditions of redox disequilibrium, such as when sulfate-reducing bacteria release sulfide into oxic groundwater, and that microbial sulfide production is expected to enhance arsenic mobilization in sedimentary rock aquifers with major pyrite-bearing, black

  7. Sulfided heterogeneous, bimetallic RuMo catalysts derived from mixtures of Ru{sub 3}(CO){sub 12} (or RuCl{sub 3}) and a molybdenum heteropolyanion. The reactions of ethanol with tetrahydroquinoline

    Energy Technology Data Exchange (ETDEWEB)

    Koo, Sang-Man; Ryan, D.; Laine, R.M.

    1992-09-01

    Efforts have been made to develop Ru/Mo bimetallic catalyst systems for hydrodenitrogenation (HDN) of tetrahydroquinoline (THQ)- In the course of these studies, it was discovered that in ethanol, under H{sub 2} and in the presence Of CS2, Precatalyst solutions containing Ru [as Ru{sub 3} (CO){sub 12} or RuCl{sub 3}] and Mo [as the H{sub 3}PMO{sub 12}0{sub 40} heteropolyanion (HPA)] decompose to form bimetallic, sulfided particles. Particle diameters run from 0.1 to 5 {mu}m depending on the rate of stirring. Catalyst particles with sizes ranging from 0.1--1 {mu}m can be prepared reproducibly. BET measured surface areas for these size particles ranged from 2 to 20 m2/g. These sulfided particles were found to catalyze, at temperatures of 200--250{degrees}C and hydrogen pressures of 200--1000 psig H{sub 2}, the N-ethylation of THQ to form NEt-THQ; rather than the formation of propylcyclohexane or propylbenzene, reaction products expected for HDN of THQ. Monometallic heterogeneous catalysts prepared from the individual precatalyst complexes, under identical conditions, show minimal activity for N-ethylation by comparison with the bimetallic catalyst. In the absence of H{sub 2}, the reaction proceeds such that THQ is converted to Q, N-EtTHQ, N-C{sub 6}H{sub 9}-THQ, and N-C{sub 6}H{sub 13}-THQ. The latter products appear to arise via acetaldehyde, formed as an intermediate by dehydrogenation of ethanol. Acetaldehyde either condenses with THQ to form N-Et-THQ, or self condenses (aldol condensation) prior to reaction with THQ thereby giving higher homolog alkylation products.

  8. Sulfided heterogeneous, bimetallic RuMo catalysts derived from mixtures of Ru sub 3 (CO) sub 12 (or RuCl sub 3 ) and a molybdenum heteropolyanion. The reactions of ethanol with tetrahydroquinoline

    Energy Technology Data Exchange (ETDEWEB)

    Koo, Sang-Man; Ryan, D.; Laine, R.M.

    1992-01-01

    Efforts have been made to develop Ru/Mo bimetallic catalyst systems for hydrodenitrogenation (HDN) of tetrahydroquinoline (THQ)- In the course of these studies, it was discovered that in ethanol, under H{sub 2} and in the presence Of CS2, Precatalyst solutions containing Ru (as Ru{sub 3} (CO){sub 12} or RuCl{sub 3}) and Mo (as the H{sub 3}PMO{sub 12}0{sub 40} heteropolyanion (HPA)) decompose to form bimetallic, sulfided particles. Particle diameters run from 0.1 to 5 {mu}m depending on the rate of stirring. Catalyst particles with sizes ranging from 0.1--1 {mu}m can be prepared reproducibly. BET measured surface areas for these size particles ranged from 2 to 20 m2/g. These sulfided particles were found to catalyze, at temperatures of 200--250{degrees}C and hydrogen pressures of 200--1000 psig H{sub 2}, the N-ethylation of THQ to form NEt-THQ; rather than the formation of propylcyclohexane or propylbenzene, reaction products expected for HDN of THQ. Monometallic heterogeneous catalysts prepared from the individual precatalyst complexes, under identical conditions, show minimal activity for N-ethylation by comparison with the bimetallic catalyst. In the absence of H{sub 2}, the reaction proceeds such that THQ is converted to Q, N-EtTHQ, N-C{sub 6}H{sub 9}-THQ, and N-C{sub 6}H{sub 13}-THQ. The latter products appear to arise via acetaldehyde, formed as an intermediate by dehydrogenation of ethanol. Acetaldehyde either condenses with THQ to form N-Et-THQ, or self condenses (aldol condensation) prior to reaction with THQ thereby giving higher homolog alkylation products.

  9. Luminescence of high-doped calcium sulfide crystals

    International Nuclear Information System (INIS)

    Calcium sulfide crystals grown by high-temperatur mineralization tecnique have been studied. Bands peaked at 2.12 and 2.5-2.7 eV are considered the most invariable features of cathodoluminescence and photoluminescence spectra. It has been found that the 2.12 eV band is conditioned by optical electronic transitions in Mn2+ ions substituted for Ca2+ ions in the host lattice. The exciton mechanism of energy transfer to centers, that are responsible for the high-energy luminescence band, is discussed

  10. Hydrogen evolution on nano-particulate transition metal sulfides

    DEFF Research Database (Denmark)

    Bonde, Jacob Lindner; Moses, Poul Georg; Jaramillo, Thomas F.;

    2008-01-01

    The hydrogen evolution reaction (HER) on carbon supported MoS2 nanoparticles is investigated and compared to findings with previously published work on Au(111) supported MoS2. An investigation into MoS2 oxidation is presented and used to quantify the surface concentration of MoS2. Other metal...... sulfides with morphologies similar to MoS2 such as WS2, cobalt- promoted WS2, and cobalt-promoted MoS2 were also investigated in the search for improved HER activity. Experimental findings are compared to density functional theory (DFT) calculated values for the hydrogen binding energies (Delta G...

  11. Isolation and characterization of deodorizing bacteria for organic sulfide malodor

    Institute of Scientific and Technical Information of China (English)

    JIANG An-xi; LIU Bo; ZHAO Yang-guo; LI Zheng; BAI Yu; CHENG Yang-xue

    2004-01-01

    Strain Jll screened out from different odor origins can efficiently degrade methyl mercaptan and ethanethiol whereas has no ability to remove dimethyl sulfide. The results indicated that the strain Jll breaks only the C-SH bond. The optimum temperature and pH of Jll are 20-30℃ and 6.0-8.3 respectively. A systematic identification method-16S rDNA gene sequence comparison, for deodorizing bacteria was carried out. The 16S rDNA gene sequence analysis of strain Jll showed the highest level of 97% homology to Rape rhizosphere.

  12. Effect of mineral processing wastewater on flotation of sulfide minerals

    Institute of Scientific and Technical Information of China (English)

    CHEN Jian-ming; LIU Run-qing; SUN Wei; QIU Guan-zhou

    2009-01-01

    The effects of mineral processing wastewater on sulfide minerals were investigated by flotation, infrared spectrometry and electrochemistry test. The results show that lead-concentrate water can improve the flotation of galena, while the sulfur-concentrate water has negative effect on flotation of galena compared with distilled water. The flotation behavior of pyrite is contrary to that of galena in three kinds of water. Infrared spectra indicate that the residual collector in the lead-concentrate water is beneficial to the formation of lead xanthate on the surface of galena. Electrochemistry results indicate that electrochemistry reaction on galena surface has apparent change. The anode polarization is improved and cathode polarization is depressed.

  13. Dynamic corrosion of copper-nickel sulfide by Acidithiobacillus ferrooxidans

    Institute of Scientific and Technical Information of China (English)

    TONG Lin-lin; JIANG Mao-fa; YANG Hong-ying; YU Juan; FAN You-jing; ZHANG Yao

    2009-01-01

    The dynamic corrosion process of bio-oxidation of copper-nickel sulfide from Karatungk in northern Xinjiang Province of China was studied. The polished wafer of the copper-nickel sulphide was used to carry on a series of oxidation corrosion experiment by Acidithiobacillus ferrooxidans. The changes of superficial corrosion appearance and the mineral dynamic corrosion process were discovered by microscope observation. Then, the galvanic cell model was established, and the bio-oxidation activation order of typical copper-nickel sulphide minerals was ascertained as pyrrhotite>pentlandite>chalocopyrite.

  14. The summer of hydrogen sulfide: highlights from two international conferences

    OpenAIRE

    Calvert, John W

    2013-01-01

    A great deal of interest has been paid recently to the hydrogen sulfide, the newest member of the gasotransmitter family. With the growing interest in the biology of H2S, the need for meetings and conferences dedicated solely to the field of H2S has also grown. In 2009, scientist from around the world met in Shanghai, China for the first time to discuss the physiological relevance of H2S. In 2012, two conferences were organized to bring scientists, clinicians, and industry representatives tog...

  15. Surface-treatment of Alkaline Earth Sulfides Based Phosphor

    Institute of Scientific and Technical Information of China (English)

    GUO Chong-feng; CHU Ben-li; XU Jian; SU Qiang

    2004-01-01

    A series of alkaline earth sulfides based phosphors Ca0.8Sr0.2S∶Eu2+, Tm3+ were covered with a layer of protective coating with alkaline earth fluorides by heating the mixture of phosphor and NH4HF2 at elevated temperatures. The coatings were characterized by means of XRD and SEM. The optical properties of the coated phosphors and the influences of the coating on their properties have been discussed extensively. The stabilities of the coated and uncoated phosphors have been compared.

  16. Iron (III) sulfide particles produced by a polyol method

    Science.gov (United States)

    Shimizu, Ryo; Kubono, Ippei; Kobayashi, Yoshio; Yamada, Yasuhiro

    2015-04-01

    Iron(III) sulfide Fe2S3 particles were produced using a polyol method. Although pyrrhotite Fe1-xS appeared together with Fe2S3, the relative yield of Fe2S3 changed when the concentration of reagents in the oleylamine changed. Mössbauer spectra of the particles showed superparamagnetic doublets due to Fe2S3 at 293 K, along with a hyperfine magnetic splitting of H = 24.7 T at 6 K. XRD patterns of the Fe2S3 suggested a structure similar to that of greigite Fe3S4.

  17. Zinc sulfide in intestinal cell granules of Ancylostoma caninum adults

    Energy Technology Data Exchange (ETDEWEB)

    Gianotti, A.J.; Clark, D.T.; Dash, J. (Portland State Univ., OR (USA))

    1991-04-01

    A source of confusion has existed since the turn of the century about the reddish brown, weakly birefringent 'sphaerocrystals' located in the intestines of strongyle nematodes, Strongylus and Ancylostoma. X-ray diffraction and energy dispersive spectrometric analyses were used for accurate determination of the crystalline order and elemental composition of the granules in the canine hookworm Ancylostoma caninum. The composition of the intestinal pigmented granules was identified unequivocally as zinc sulfide. It seems most probable that the granules serve to detoxify high levels of metallic ions (specifically zinc) present due to the large intake of host blood.

  18. Therapeutic application of hydrogen sulfide donors: the potential and challenges.

    Science.gov (United States)

    Wu, Dan; Hu, Qingxun; Zhu, Yizhun

    2016-03-01

    Hydrogen sulfide (H2S), a colorless gas smelling of rotten egg, has long been considered a toxic gas and environment hazard. However, evidences show that H2S plays a great role in many physiological and pathological activities, and it exhibits different effects when applied at various doses. In this review, we summarize the chemistry and biomedical applications of H2S-releasing compounds, including inorganic salts, phosphorodithioate derivatives, derivatives of Allium sativum extracts, derivatives of thioaminoacids, and derivatives of antiinflammatory drugs. PMID:26597301

  19. Efeito do trinexapac-ethyl na anatomia foliar de quatro espécies de grama Trinexapac-ethyl effect on the leaf anatomy of four turfgrass species

    Directory of Open Access Journals (Sweden)

    N.V. Costa

    2010-01-01

    Full Text Available Os reguladores de crescimento podem retardar o desenvolvimento vegetativo das plantas de gramas e, assim, reduzir a frequência de cortes; contudo, existem poucas informações referentes aos efeitos desses produtos sobre as estruturas da anatomia foliar. Dessa forma, o presente trabalho teve por objetivo avaliar os efeitos da aplicação sequencial de duas doses de trinexapac-ethyl sobre a anatomia foliar das espécies de gramas São Carlos (Axonopus compressus, Batatais (Paspalum notatum, Santo Agostinho (Stenotaphrum secundatum e Esmeralda (Zoysia japonica. Os tratamentos utilizados foram constituídos de duas aplicações sequenciais de trinexapac-ethyl nas doses de 56,5+56,5 e 113,0+113,0 g ha-1; além de uma testemunha sem aplicação, para cada espécie avaliada. Os gramados foram cortados à altura de 3 cm, com auxílio de um aparador de grama motorizado, e, em seguida, foram realizadas as aplicações dos tratamentos. Após 20 dias da primeira aplicação de trinexapac-ethyl, as parcelas foram novamente aparadas à altura de 3 cm e foi realizada a segunda aplicação dos tratamentos. O delineamento experimental utilizado foi o de blocos ao acaso, com quatro repetições. Aos 70 dias após a segunda aplicação dos tratamentos, foram realizadas as amostragens do material foliar, para as quatro espécies estudadas. Os dados das variáveis quantitativas foram submetidos ao teste estatístico multivariado de análise de componentes principais. Os resultados evidenciaram a formação de três e dois grupos principais, para os caracteres da região da quilha (nervura mediana e da região da asa (situada entre a nervura mediana e a margem do limbo foliar, respectivamente. De modo geral, em cada formação dos agrupamentos, os tratamentos com trinexapac-ethyl apresentaram maior similaridade entre si, em relação às respectivas testemunhas. Conclui-se que a aplicação sequencial de trinexapac-ethyl alterou algumas estruturas anatômicas da

  20. Biphenyl derived Schiff-base vanadium(V) complexes with pendant OH-groups--structure, characterization and hydrogen peroxide mediated sulfide oxygenation.

    Science.gov (United States)

    Plitt, Patrick; Pritzkow, Hans; Kramer, Roland

    2004-08-01

    A series of mononuclear oxovanadium(v) complexes of tridentate Schiff bases HL(1)-HL(4) and H(2)L(5)-H(2)L(8) derived from 6-phenylsalicylaldehyde and 6-(2-hydroxyphenyl)salicylaldehyde and four different amines was synthesized. The systematically selected ligands contain aliphatic or aromatic nitrogen, or alkoxy- and phenoxy-oxygen as third donor atom. The complexes were characterised by spectroscopic methods in solution and the solid state. Single-crystal X-ray analyses were performed with VO(2)L(1)(), VO(2)L(3)x1/2EtOH (), VO(2)L(4)(), VO(OiPr)L(7)xiPrOH, VO(OiPr)L(8) and H(2)L(8). For all compounds the vanadium(v) cores contain distorted tetragonal pyramidal geometry around the dioxo- and oxovanadium site at which the N(2)O- and NO(2)-donor ligands bind equatorially. Complexes and display intramolecular hydrogen bonding of the pendant hydroxyphenyl group to a coordinated oxygen trans to a nitrogen atom and therefore serve as suitable models for the native site of vanadium dependent haloperoxidases. Variable-temperature (1)H NMR spectra revealed significant hydrogen bond interaction in acetonitrile solution. In situ prepared catalysts are active for hydrogen peroxide mediated oxygenation of ethyl phenyl sulfide and showed complete conversion of the substrate to ethyl phenyl sulfoxide, together with small amounts of the corresponding sulfone, as detected by GC/MS after 10 min. The complex of H(2)L(7) turned out to be most efficient while HL(1) and HL(2) were completely inactive. Catalysis is supported by the pendant OH group in the complex of HL(3), the catalyst is twice as active as the complex of HL(4). PMID:15278124

  1. Transesterification of vegetable oils with ethanol and characterization of the key fuel properties of ethyl esters

    Energy Technology Data Exchange (ETDEWEB)

    Anastopoulos, G.; Zannikou, Y.; Stournas, S. [National Technical University of Athens, School of Chemical Engineering, Laboratory of Fuels Technology and Lubricants, Iroon Polytechniou 9, Athens 15780 (Greece); Kalligeros, S. [Hellenic Organization for Standardization, Technical Committee 66, 67 Prevezis Street, Athens, 10444 (Greece)

    2009-07-01

    The transesterification reactions of four different vegetable oils (sunflower, rapeseed, olive oil and used frying oil) with ethanol, using sodium hydroxide as catalyst, were studied. The ester preparation involved a two-step transesterification reaction, followed by purification. The effects of the mass ratio of catalyst to oil (0.25 - 1.5%), the molar ratio of ethanol to oil (6:1 - 12:1), and the reaction temperature (35 - 90 {sup o}C) were studied for the conversion of sunflower oil to optimize the reaction conditions in both stages. The rest of the vegetable oils were converted to ethyl esters under optimum reaction parameters. The optimal conditions for first stage transesterification were an ethanol/oil molar ratio of 12:1, NaOH amount (1% wt/wt), and 80 {sup o}C temperature, whereas the maximum yield of ethyl esters reached 81.4% wt/wt. In the second stage, the yield of ethyl esters was improved by 16% in relation with the one-stage transesterification, which was obtained under the following optimal conditions: catalyst concentration 0.75% and ethanol/oil molar ratio 6:1. The fuel properties of the esters were measured according to EN test methods. Based on the experimental results one can see that the ethyl esters do not differ significantly from methyl esters. Moreover, the results showed that the values of density, viscosity, and higher heating value of ethyl esters were similar to those of automotive and heavy duty engine diesel fuel. However, the CFPP values were higher, which may contribute to potential difficulties in cold starts. On the other hand, the flash points, which were higher than those of diesel fuel constituted a safety guarantee from the point of view of handling and storage. (author)

  2. Transesterification of Vegetable Oils with Ethanol and Characterization of the Key Fuel Properties of Ethyl Esters

    Directory of Open Access Journals (Sweden)

    Stamoulis Stournas

    2009-06-01

    Full Text Available The transesterification reactions of four different vegetable oils (sunflower, rapeseed, olive oil and used frying oil with ethanol, using sodium hydroxide as catalyst, were studied. The ester preparation involved a two-step transesterification reaction, followed by purification. The effects of the mass ratio of catalyst to oil (0.25 – 1.5%, the molar ratio of ethanol to oil (6:1 – 12:1, and the reaction temperature (35 – 90 °C were studied for the conversion of sunflower oil to optimize the reaction conditions in both stages. The rest of the vegetable oils were converted to ethyl esters under optimum reaction parameters. The optimal conditions for first stage transesterification were an ethanol/oil molar ratio of 12:1, NaOH amount (1% wt/wt, and 80 °C temperature, whereas the maximum yield of ethyl esters reached 81.4% wt/wt. In the second stage, the yield of ethyl esters was improved by 16% in relation with the one-stage transesterification, which was obtained under the following optimal conditions: catalyst concentration 0.75% and ethanol/oil molar ratio 6:1. The fuel properties of the esters were measured according to EN test methods. Based on the experimental results one can see that the ethyl esters do not differ significantly from methyl esters. Moreover, the results showed that the values of density, viscosity, and higher heating value of ethyl esters were similar to those of automotive and heavy duty engine diesel fuel. However, the CFPP values were higher, which may contribute to potential difficulties in cold starts. On the other hand, the flash points, which were higher than those of diesel fuel constituted a safety guarantee from the point of view of handling and storage.

  3. Ranitidine hydrochloride-loaded ethyl cellulose and eudragit Rs 100 buoyant microspheres: Effect of ph modifiers

    Directory of Open Access Journals (Sweden)

    N R Kotagale

    2011-01-01

    Full Text Available A floating type of dosage form of ranitidine hydrochloride in the form of microspheres capable of floating on simulated gastric fluid was prepared by solvent evaporation technique. Microspheres prepared with ethyl cellulose, Eudragit® RS100 alone or in combination were evaluated for percent yield, drug entrapment, percent buoyancy and drug release and the results demonstrated satisfactory performance. Microspheres exhibited ranitidine hydrochloride release influenced by changing ranitidine hydrochloride-polymer and ranitidine hydrochloride-polymer-polymer ratio. Incorporation of a pH modifier has been the usual strategy employed to enhance the dissolution rate of weakly basic drug from floating microspheres. Further citric acid, fumaric acid, tartaric acid were employed as pH modifiers. Microspheres prepared with ethyl cellulose, Eudragit® RS100 and their combination that showed highest release were utilized to study the effect of pH modifiers on ranitidine hydrochloride release from microspheres which is mainly affected due to modulation of microenvironmental pH. In vitro release of ranitidine hydrochloride from microspheres into simulated gastric fluid at 37° showed no significant burst effect. However the amount of release increased with time and significantly enhanced by pH modifiers. 15% w/w concentration of fumaric acid provide significant drug release from ranitidine hydrochloride microspheres prepared with ranitidine hydrochloride:ethyl cellulose (1:3, ranitidine hydrochloride:Eudragit® RS100 (1:2 and ranitidine hydrochloride:ethyl cellulose:Eudragit® RS100 (1:2:1 whereas citric acid, tartaric acid showed significant cumulative release at 20% w/w. In all this study suggest that ethyl celluose, Eudragit® RS100 alone or in combination with added pH modifiers can be useful in floating microspheres which can be proved beneficial to enhance the bioavailability of ranitidine hydrochloride.

  4. Bioactivity of Diterpens from the Ethyl Acetate Extract of Kingiodendron pinnatum Rox. Hams

    Science.gov (United States)

    Javarappa, Komal Kumar; Prasad, Attemode Girijanna Devi; Mahadesh Prasad, AJ; Mane, Chetana

    2016-01-01

    Background: Kingiodendron pinnatum Rox. Hams. is an endangered medicinal plant used in gonorrhoe, catarrhal conditions of genito-urinary and respiratory tracts. The scientific and pharmacological formulation of K. pinnatum has not been established so far though it is being traditionally used by tribes of the region. Objective: P hytochemical screening and identification of the bioactive compounds from the ethyl acetate extract of Kingiodendron pinnatum Rox. Hams. Materials and Methods: Chromatographic separation was carried out by thin layer chromatography and column chromatography. Bio-autography of the column fractioned extract and TLC chromatogram were evaluated in vitro for antibacterial activity. The PTLC, HP TLC were used for crude extract and HPLC, LCMS, FTIR, 1HNMR and 13CNMR were employed for the isolated compound in the ethyl acetate extract of K. pinnatum. Results: Evaluation of solvent system for chromatographic separation revealed that ethyl acetate: petroleum ether in the ratio of 7:2.5 ml was the most appropriate one for the separation of diterpene compounds. The antibacterial bio-autography screening of TLC separated compound showed positive activity with Staphylococcus aureus and negative activity with Escherichia coli. Spectroscopic analysis of the isolated compound from the ethyl acetate extract of K. pinnatum revealed the presence of diterpene compound. Conclusion: It is evident from the present study that the ethyl acetate extract of K. pinnatum is rich in diterpene compounds and having potential antibacterial activity. SUMMARY Novel extraction method for phytochemicls from Kingidendron pinnatum at RTAntibacterial property of diterpens extracted from Kingiodendron pinnatum Rox. Hams aganist S. aureus Abbreviations Used: TLC: Thin Layer Chromatography, PTLC: Preparatory Thin Layer Chromatography, HPTLC: High perormence Thin Layer chromatography, HPLC: High Performance Liquid Chromatography, LC-MS: Liquid chromatography Mass Spectra, FTIR

  5. Rice: Sulfide-induced Barriers to Root Radial Oxygen Loss, Fe2+ and Water Uptake, and Lateral Root Emergence

    OpenAIRE

    ARMSTRONG, JEAN; Armstrong, William (Canadian painter, civil engineer, photographer, 1822-1914)

    2005-01-01

    • Background and Aims Akagare and Akiochi are diseases of rice associated with sulfide toxicity. This study investigates the possibility that rice reacts to sulfide by producing impermeable barriers in roots.

  6. Sulfide intrusion in seagrasses assessed by stable sulfur isotopes—a synthesis of current results

    DEFF Research Database (Denmark)

    Holmer, Marianne; Hasler-Sheetal, Harald

    2014-01-01

    Sulfide intrusion in seagrasses, as assessed by stable sulfur isotope signals, is widespread in all climate zones, where seagrasses are growing. Seagrasses can incorporate substantial amounts of 34S-depleted sulfide into their tissues with up to 87% of the total sulfur in leaves derived from sedi...

  7. The impact of electrogenic sulfide oxidation on elemental cycling and solute fluxes in coastal sediment

    NARCIS (Netherlands)

    Rao, A.M.F.; Malkin, S.Y.; Hidalgo-Martinez, S.; Meysman, Filip

    2016-01-01

    Filamentous sulfide oxidizing cable bacteria are capable of linking the oxidation of free sulfide in deep anoxic layers of marine sediments to the reduction of oxygen or nitrate in surface sediments by conducting electrons over centimeter-scale distances. Previous studies have shown that this newly

  8. Electron microscopy investigation of the microstructure of unsupported Ni-Mo-W sulfide

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, B.S. [Department of Inorganic Chemistry, Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195 Berlin (Germany); Yi, Y.J. [Laboratory of Advanced Materials and Catalytic Engineering, School of Chemical Engineering, Dalian University of Technology, 158 Zhongshan Road, 116012 Dalian (China); Zhang, W. [Department of Inorganic Chemistry, Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195 Berlin (Germany); Liang, C.H. [Laboratory of Advanced Materials and Catalytic Engineering, School of Chemical Engineering, Dalian University of Technology, 158 Zhongshan Road, 116012 Dalian (China); Su, D.S., E-mail: dangsheng@fhi-berlin.mpg.de [Department of Inorganic Chemistry, Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195 Berlin (Germany)

    2011-07-15

    An exploration was made on structure and active sites of the unsupported Ni-Mo-W sulfide hydrodesulphurization catalyst prepared by a thiosalt decomposition method. More insights into the nanocomposite structure were provided by introducing the concept of average curvature of Mo(W)S{sub 2} and establishing a new structure model. The defects of cross and mixed stacks, steps along c-axis, expansion of (002) interplanar spacing and mixing structure of Mo(W)/Ni sulfides were investigated using advanced electron microscopy. All these defects in Mo(W) sulfides are closely correlated with increasing active sites of unsupported Ni-Mo-W sulfide catalyst. - Graphical Abstract: From the top schematic of unsupported Ni-Mo-W sulfide, the MoS{sub 2}, WS{sub 2}, or Mo{sub x}W{sub 1-x}S{sub 2} are surrounded by the dispersed Ni sulfide, which make the formation of nanocomposite phases possible. For the bottom colorized high-resolution transmission electron microscopy image with 3D rotation, the variation in sample thickness leads to a varying representation of the contrast of the Ni-Mo-W sulfide sheet, ... Research Highlights: {yields} Rich microstructural features of unsupported Ni-Mo-W sulfide catalyst were revealed. {yields} Curvature of HDS catalyst was firstly proposed, also illustrative for other catalysts. {yields} Insights into the nano-composite were gained from its new structure model.

  9. Inhibition of a biological sulfide oxidation under haloalkaline conditions by thiols and diorgano polysulfanes

    NARCIS (Netherlands)

    Roman, Pawel; Lipińska, Joanna; Bijmans, Martijn F.M.; Sorokin, Dimitry Y.; Keesman, Karel J.; Janssen, Albert J.H.

    2016-01-01

    A novel approach has been developed for the simultaneous description of reaction kinetics to describe the formation of polysulfide and sulfate anions from the biological oxidation of hydrogen sulfide (H2S) using a quick, sulfide-dependent respiration test. Next to H2S, thiol

  10. Inhibition of microbiological sulfide oxidation at natronophilic conditions by methanethiol and methylated polysulfides

    NARCIS (Netherlands)

    Bosch, van den P.L.F.; Graaff, de C.M.; Fortuny-Picornell, M.; Leerdam, van R.C.; Janssen, A.J.H.

    2009-01-01

    To avoid problems related to the discharge of sulfidic spent caustics, a biotechnological process is developed for the treatment of gases containing both hydrogen sulfide and methanethiol. The process operates at natron-alkaline conditions (>1 mol L-1 of sodium- and potassium carbonates and a pH

  11. Synthetic Fabrication of Nanoscale MoS2-Based Transition Metal Sulfides

    Directory of Open Access Journals (Sweden)

    Jikang Yuan

    2010-01-01

    Full Text Available Transition metal sulfides are scientifically and technologically important materials. This review summarizes recent progress on the synthetic fabrication of transition metal sulfides nanocrystals with controlled shape, size, and surface functionality. Special attention is paid to the case of MoS2 nanoparticles, where organic (surfactant, polymer, inorganic (support, promoter, doping compounds and intercalation chemistry are applied.

  12. Growth kinetics of hydrogen sulfide oxidizing bacteria in corroded concrete from sewers.

    Science.gov (United States)

    Jensen, Henriette Stokbro; Lens, Piet N L; Nielsen, Jeppe L; Bester, Kai; Nielsen, Asbjørn Haaning; Hvitved-Jacobsen, Thorkild; Vollertsen, Jes

    2011-05-30

    Hydrogen sulfide oxidation by microbes present on concrete surfaces of sewer pipes is a key process in sewer corrosion. The growth of aerobic sulfur oxidizing bacteria from corroded concrete surfaces was studied in a batch reactor. Samples of corrosion products, containing sulfur oxidizing bacteria, were suspended in aqueous solution at pH similar to that of corroded concrete. Hydrogen sulfide was supplied to the reactor to provide the source of reduced sulfur. The removal of hydrogen sulfide and oxygen was monitored. The utilization rates of both hydrogen sulfide and oxygen suggested exponential bacterial growth with median growth rates of 1.25 d(-1) and 1.33 d(-1) as determined from the utilization rates of hydrogen sulfide and oxygen, respectively. Elemental sulfur was found to be the immediate product of the hydrogen sulfide oxidation. When exponential growth had been achieved, the addition of hydrogen sulfide was terminated leading to elemental sulfur oxidation. The ratio of consumed sulfur to consumed oxygen suggested that sulfuric acid was the ultimate oxidation product. To the knowledge of the authors, this is the first study to determine the growth rate of bacteria involved in concrete corrosion with hydrogen sulfide as source of reduced sulfur.

  13. Growth kinetics of hydrogen sulfide oxidizing bacteria in corroded concrete from sewers

    International Nuclear Information System (INIS)

    Hydrogen sulfide oxidation by microbes present on concrete surfaces of sewer pipes is a key process in sewer corrosion. The growth of aerobic sulfur oxidizing bacteria from corroded concrete surfaces was studied in a batch reactor. Samples of corrosion products, containing sulfur oxidizing bacteria, were suspended in aqueous solution at pH similar to that of corroded concrete. Hydrogen sulfide was supplied to the reactor to provide the source of reduced sulfur. The removal of hydrogen sulfide and oxygen was monitored. The utilization rates of both hydrogen sulfide and oxygen suggested exponential bacterial growth with median growth rates of 1.25 d-1 and 1.33 d-1 as determined from the utilization rates of hydrogen sulfide and oxygen, respectively. Elemental sulfur was found to be the immediate product of the hydrogen sulfide oxidation. When exponential growth had been achieved, the addition of hydrogen sulfide was terminated leading to elemental sulfur oxidation. The ratio of consumed sulfur to consumed oxygen suggested that sulfuric acid was the ultimate oxidation product. To the knowledge of the authors, this is the first study to determine the growth rate of bacteria involved in concrete corrosion with hydrogen sulfide as source of reduced sulfur.

  14. 30 CFR 250.215 - What hydrogen sulfide (H2S) information must accompany the EP?

    Science.gov (United States)

    2010-07-01

    ... methodologies outlined in 40 CFR part 68. ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What hydrogen sulfide (H2S) information must... Contents of Exploration Plans (ep) § 250.215 What hydrogen sulfide (H2S) information must accompany the...

  15. Amperometric inhibitive biosensor based on horseradish peroxidase-nanoporous gold for sulfide determination

    Science.gov (United States)

    Sun, Huihui; Liu, Zhuang; Wu, Chao; Xu, Ping; Wang, Xia

    2016-08-01

    As a well-known toxic pollutant, sulfide is harmful to human health. In this study, a simple and sensitive amperometric inhibitive biosensor was developed for the determination of sulfide in the environment. By immobilizing nanoporous gold (NPG) on glassy carbon electrode (GCE), and encapsulating horseradish peroxidase (HRP) onto NPG, a HRP/NPG/GCE bioelectrode for sulfide detection was successfully constructed based on the inhibition of sulfide on HRP activity with o-Phenylenediamine (OPD) as a substrate. The resulted HRP/NPG/GCE bioelectrode achieved a wide linear range of 0.1–40 μM in sulfide detection with a high sensitivity of 1720 μA mM‑1 cm‑2 and a low detection limit of 0.027 μM. Additionally, the inhibition of sulfide on HRP is competitive inhibition with OPD as a substrate by Michaelis-Menten analysis. Notably, the recovery of HRP activity was quickly achieved by washing the HRP/NPG/GCE bioelectrode using differential pulse voltammetry (DPV) technique in deaerated PBS (50 mM, pH 7.0) for only 60 s. Furthermore, the real sample analysis of sulfide by the HRP/NPG/GCE bioelectrode was achieved. Based on above results, the HRP/NPG/GCE bioelectrode could be a better choice for the real determination of sulfide compared to inhibitive biosensors previously reported.

  16. Sulfide oxidation at halo-alkaline conditions in a fed-batch bioreactor

    NARCIS (Netherlands)

    Bosch, van den P.L.F.; Beusekom, van O.C.; Buisman, C.J.N.; Janssen, A.J.H.

    2007-01-01

    A biotechnological process is described to remove hydrogen sulfide (H2S) from high-pressure natural gas and sour gases produced in the petrochemical industry. The process operates at halo-alkaline conditions and combines an aerobic sulfide-oxidizing reactor with an anaerobic sulfate (SO) and thiosul

  17. A STUDY TO EVALUATE CARBON MONOXIDE AND HYDROGEN SULFIDE CONTINUOUS EMISSION MONITORS AT AN OIL REFINERY

    Science.gov (United States)

    An eleven month field evaluation was done on five hydrogen sulfide and four carbon monoxide monitors located at an oil refinery. The hydrogen sulfide monitors sampled a fuel gas feed line and the carbon monoxide monitors sampled the emissions from a fluid cat cracker (FCC). Two o...

  18. The sampling of hydrogen sulfide in air with impregnated filter paper

    NARCIS (Netherlands)

    Huygen, C.

    1964-01-01

    A method is proposed for the quantitative collection of hydrogen sulfide in air on impregnated filter paper. An aqueous solution of potassium hydroxide, potassium zincate and glycerol is used as impregnating fluid. The stability of the collected sulfide and the efficiency of collection at different

  19. Zinc stable isotope fractionation upon accelerated oxidative weathering of sulfidic mine waste.

    Science.gov (United States)

    Matthies, R; Krahé, L; Blowes, D W

    2014-07-15

    Accelerated oxidative weathering in a reaction cell (ASTM D 5744 standard protocol) was performed over a 33 week period on well characterized, sulfidic mine waste from the Kidd Creek Cu-Zn volcanogenic massive sulfide deposit, Canada. The cell leachate was monitored for physicochemical parameters, ion concentrations and stable isotope ratios of zinc. Filtered zinc concentrations (weathering processes in complex multi-phase matrices.

  20. Spin-polarized quasiparticle transport in exchange-split superconducting aluminum on europium sulfide

    Science.gov (United States)

    Wolf, M. J.; Sürgers, C.; Fischer, G.; Beckmann, D.

    2014-10-01

    We report on nonlocal spin transport in mesoscopic superconducting aluminum wires in contact with the ferromagnetic insulator europium sulfide. We find spin injection and long-range spin transport in the regime of the exchange splitting induced by europium sulfide. Our results demonstrate that spin transport in superconductors can be manipulated by ferromagnetic insulators, and opens a path to control spin currents in superconductors.

  1. Anaerobic sulfide-oxidation in marine colorless sulfur-oxidizing bacteria

    Digital Repository Service at National Institute of Oceanography (India)

    LokaBharathi, P.A.; Nair, S.; Chandramohan, D.

    50 degrees C decreased cell viability and consequently sulfide oxidation was negligible. Cell viability as estimated by the colony-forming ability decreased 100-fold after the exposure to 100 kg/cm sup(2) pressure for 1 h. Both viability and sulfide...

  2. Solubility of Hydrogen Sulfide and Methane in Ionic Liquids: 1-Ethy-3-methylimidazolium Trifluoromethanesulfonate and 1-Butyl-1-methylpyrrolidinium Trifluoromethanesulfonate

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byung-Chul [Hannam University, Seoul (Korea, Republic of)

    2016-04-15

    Solubility data of hydrogen sulfide (H{sub 2}S) and methane (CH{sub 4}) in two kinds of ionic liquids with the same anion: 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([emim][TfO]) and 1-butyl-1-methylpyrrolidinium trifluoromethanesulfonate ([bmpyr][TfO]) are presented at pressures up to about 30 MPa and at temperatures between 303 K and 343 K. The gas solubilities in ionic liquids were determined by measuring the bubble point pressures of the gas + ionic liquid mixtures with various compositions at different temperatures using a high-pressure equilibrium apparatus equipped with a variable-volume view cell. The H{sub 2}S solubilities in ionic liquid increased with the increase of pressure and decreased with the increase of temperature. On the other hand, the CH{sub 4} solubilities in ionic liquid increased significantly with the increase of pressure, but there was little effect of temperature on the CH{sub 4} solubility. For the ionic liquds [emim][TfO] and [bmpyr][TfO] with the same anion, the solubility of H{sub 2}S as a molality basis was substantially similar, regardless of the temperature and pressure conditions as a molar concentration basis. Comparing the solubilities of H{sub 2}S and CH{sub 4} in the ionic liquid [emim][TfO], the solubilities of H{sub 2}S were much greater than those of CH{sub 4}. For the same type of ionic liquid, the solubility data of H{sub 2}S and CH{sub 4} obtained in this study were compared to the solubility data of CO2 from the literature. When compared at the same pressure and temperature conditions, the CO{sub 2} solubility was in between the solubility of H{sub 2}S and CH{sub 4}.

  3. Why does the Conductivity of a Nickel Catalyst Increase during Sulfidation? An Exemplary Study Using an In Operando Sensor Device

    OpenAIRE

    Peter Fremerey; Andreas Jess; Ralf Moos

    2015-01-01

    In order to study the sulfidation of a catalyst fixed bed, an in operando single pellet sensor was designed. A catalyst pellet from the fixed bed was electrically contacted and its electrical response was correlated with the catalyst behavior. For the sulfidation tests, a nickel catalyst was used and was sulfidized with H2S. This catalyst had a very low conductivity in the reduced state. During sulfidation, the conductivity of the catalyst increased by decades. A reaction from nickel to nicke...

  4. Biological conversion of hydrogen sulfide into elemental sulfur

    Energy Technology Data Exchange (ETDEWEB)

    Basu, R.; Clausen, E.C.; Gaddy, J.L. [Bioengineering Resources, Inc., Fayetteville, AR (United States)

    1996-12-31

    Currently, hydrogen sulfide is removed from process gas streams by a series of reactions at high temperature to produce elemental sulfur in Claus, Stretford or other processes. These physicochemical processes have high intrinsic capital and operating costs, often are restricted by contaminants, and do not effectively remove all the H{sub 2}S. As an alternative, the anaerobic, photosynthetic bacterium, Chlorobium thiosulfatophilum, has been demonstrated to convert hydrogen sulfide to elemental sulfur in a single step at atmospheric conditions. The autotrophic bacterium uses CO{sub 2} as the carbon source. Energy for cell metabolism is provided by incandescent light and the oxidation of H{sub 2}S. A bench scale study has been performed in a CSTR equipped with a sulfur separator. Optimum process conditions have been achieved to maximize cell growth and elemental sulfur production. Near total conversion of H{sub 2}S is achieved in a retention time of a few minutes. High concentrations of H{sub 2}S or organics do not affect the culture. Sulfur recovery by settling is very efficient and near theoretical yields of sulfur are achieved. Economic projections indicate that sour gas can be desulfurized for $0.08-0.12/MSCF. 13 refs.

  5. Control of microbially generated hydrogen sulfide in produced waters

    Energy Technology Data Exchange (ETDEWEB)

    Burger, E.D.; Vance, I.; Gammack, G.F.; Duncan, S.E.

    1995-12-31

    Production of hydrogen sulfide in produced waters due to the activity of sulfate-reducing bacteria (SRB) is a potentially serious problem. The hydrogen sulfide is not only a safety and environmental concern, it also contributes to corrosion, solids formation, a reduction in produced oil and gas values, and limitations on water discharge. Waters produced from seawater-flooded reservoirs typically contain all of the nutrients required to support SRB metabolism. Surface processing facilities provide a favorable environment in which SRB flourish, converting water-borne nutrients into biomass and H{sub 2}S. This paper will present results from a field trial in which a new technology for the biochemical control of SRB metabolism was successfully applied. A slip stream of water downstream of separators on a produced water handling facility was routed through a bioreactor in a side-steam device where microbial growth was allowed to develop fully. This slip stream was then treated with slug doses of two forms of a proprietary, nonbiocidal metabolic modifier. Results indicated that H{sub 2}S production was halted almost immediately and that the residual effect of the treatment lasted for well over one week.

  6. Accelerating column leaching trial on copper sulfide ore

    Institute of Scientific and Technical Information of China (English)

    WANG Hongjiang; WU Aixiang; ZHOU Xun; WANG Shaoyong; ZHANG Jie

    2008-01-01

    The main measures to accelerate leaching sulfide ore are large spraying intensity,manual oxygen supply,temperature control and acclimated bacteria.The indoor experiment accelerating sulfide ore leaching detected the temperature during leaching process,dissolvability of oxygen,bacterial concentration,Cu concentration and slag grade.At the same time,this paper also analyzed the effect of four factors,which are bacterial diversity cultivation stage,spraying intensity,air supply,and whether to control temperature,on the leaching efficiency of copper.The results indicate that the oxygen content of leach solution has a close relationship with temperature but it is rarely affected by air supply.The bacterial concentration preserves from 106 to 107 mL-1,and temperature has a great effect on the bacterial activity under the condition of proper temperature and oxygen supply,and the lack of nutrition prevents the bacterial concentration from rising in the late stage.The relationships of the copper leaching efficiency to temperature,air feed,and spraying intensity are directly proportional.The leaching efficiencies of the cultivated bacteria and acclimation bacteria are 1.2 and 1.4 times as large as that of the original bacteria.

  7. Sulfide mineralization: Its role in chemical weathering of Mars

    Science.gov (United States)

    Burns, Roger G.

    1988-01-01

    Pyrrhotite-pentlandite assemblages in mafic and ultramafic igneous rocks may have contributed significantly to the chemical weathering reactions that produced degradation products in the Martian regolith. By analogy with terrestrial processes, a model is proposed whereby supergene alteration of these primary Fe-Ni sulfides on Mars has generated secondary sulfides (e.g., pyrite) below the water table and produced acidic groundwater containing high concentrations of dissolved Fe, Ni and sulfate ions. The low pH solutions also initiated weathering reactions of igneous feldspars and ferromagnesian silicates to form clay silicate and ferric oxyhydroxide phases. Near-surface oxidation and hydrolysis of ferric sulfato- and hydroxo-complex ions and sols formed gossans above the water table consisting of poorly crystalline hydrated ferric sulfates (e.g., jarosite), oxides (ferrihydrite, goethite) and silica (opal). Underlying groundwater, now permafrost, contains hydroxo sulfato complexes of Fe, Al, Mg, Ni, etc., which may be stabilized in frozen acidic solutions beneath the surface of Mars. Sublimation of permafrost may replenish colloidal ferric oxides, sulfates and phyllosilicates during dust storms on Mars.

  8. Bioleaching of low grade nickel sulfide mineral in column reactor

    Institute of Scientific and Technical Information of China (English)

    ZHEN Shi-jie; QIN Wen-qing; YAN Zhong-qiang; ZHANG Yan-sheng; WANG Jun; REN Liu-yi

    2008-01-01

    Jinchuan low grade nickel (0.4%-0.6% Ni,mass fraction) sulfide mineral ore contains a remarkably high content of magnesia (30%-35% MgO,mass fraction) present in the main gangue minerals.Bioleaching was performed to investigate the feasibility to process the mineral due to its relative simplicity,eco-friendly operation and low capital cost requirements.The mixed mesophiles were enriched from acid mine drainage samples collected from several acid mines in China.Considering that the magnesia is easily extracted by acid solution and the excessive Mg2+ will exceed the tolerance of the mixed mesophiles,three effective means were used to reduce the disadvantage of magnesia during the bioleaching operation.They were adaptation of the mixed mesophiles to improve the tolerance; pre-leaching to remove most leachable magnesia and periodic bleeds of a portion of the pregnant leaching solution to control the level of Mg2+ based on the tolerance of the mixed mesophiles.An extraction of nickel (90.3%) and cobalt (88.6%) was successfully achieved within a 300 d leaching process from the Jinchuan low grade nickel sulfide mineral ore using a column reactor at ambient temperature.

  9. Heavy Metals in a Sulfidic Minespoil: Fractions and Column Leaching

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Fractions of various heavy metals in a sulfidic minespoil were investigated. Column leaching experimentwas also conducted to simulate "acid mine drainage" (AMD) from the minespoil. The results show thatleaching of heavy metals from the minespoil was extremely significant during the initial water flushing.The amounts of heavy metals leached out dramatically reduced after leaching twice. It is worthwhile tonote that in this study, Zn, Mn, Fe, As and Ni in the first leachate exceeded the total amount of eachcorresponding water-extractable (1:5, soil:water) metal contained in the minespoil sample. This appears tosuggest that 1:5 water extraction did not allow accurate estimation of water-leachable concentrations of theabove heavy metals. This work has implications for the management of sulfidic minespoils. Acid drainageof great environmental concerns is likely to occur only during heavy rainfall events after substantial solubleand readily exchangeable acid and metals are accumulated in the minespoils. The slow-reacting fractionsother than water-soluble and readily exchangeable fractions may pose little environmental hazards. This isparticularly true for Pb, As and Ni.

  10. Atmospheric Sulfur Cycle Effects of Carbonyl Sulfide (OCS)

    Science.gov (United States)

    McBee, Joshua

    1996-01-01

    Carbonyl Sulfide(OCS) is considered to be one of the major sources of sulfur appearing in the stratosphere due to its relative inertness, about I to 10 yearsl. However, the roles of OCS as well as other reduced sulfur compounds such as carbon disulfide (CS2), hydrogen sulfide (H2S), and dimethyl disulfide(CH3)2S2, are not completely understood in the atmosphenc sulfur cycle. Consequently vely little information is available about the effect of sulfur compounds in the stratosphere. The ability of OCS to penetrate into the stratosphere makes it an excellent tracer for study of the role of the sulfi r cycle in stratospheric chemistry. Previously techniques such as gas chromatography and whole air sampling have been used to measure OCS analytically. Each technique had its drawbacks however, with both being quite slow, and whole air sampling being somewhat unreliable. With molecular spectroscopy, however, it has been found in recent years that the tunable diode laser absorption spectrometer (TDL) provides a very rapid and accurate method of measuring OCS and other trace gases

  11. Hydrogen sulfide intervention in focal cerebral ischemia/reperfusion injury in rats

    Directory of Open Access Journals (Sweden)

    Xin-juan Li

    2015-01-01

    Full Text Available The present study aimed to explore the mechanism underlying the protective effects of hydrogen sulfide against neuronal damage caused by cerebral ischemia/reperfusion. We established the middle cerebral artery occlusion model in rats via the suture method. Ten minutes after middle cerebral artery occlusion, the animals were intraperitoneally injected with hydrogen sulfide donor compound sodium hydrosulfide. Immunofluorescence revealed that the immunoreactivity of P2X 7 in the cerebral cortex and hippocampal CA1 region in rats with cerebral ischemia/reperfusion injury decreased with hydrogen sulfide treatment. Furthermore, treatment of these rats with hydrogen sulfide significantly lowered mortality, the Longa neurological deficit scores, and infarct volume. These results indicate that hydrogen sulfide may be protective in rats with local cerebral ischemia/reperfusion injury by down-regulating the expression of P2X 7 receptors.

  12. What do we really know about the role of microorganisms in iron sulfide mineral formation?

    Science.gov (United States)

    Picard, Aude; Gartman, Amy; Girguis, Peter

    2016-06-01

    Iron sulfide mineralization in low-temperature systems is a result of biotic and abiotic processes, though the delineation between these two modes of formation is not always straightforward. Here we review the role of microorganisms in the precipitation of extracellular iron sulfide minerals. We summarize the evidence that links sulfur-metabolizing microorganisms and sulfide minerals in nature and we present a critical overview of laboratory-based studies of the nucleation and growth of iron sulfide minerals in microbial cultures. We discuss whether biologically derived minerals are distinguishable from abiotic minerals, possessing attributes that are uniquely diagnostic of biomineralization. These inquiries have revealed the need for additional thorough, mechanistic and high-resolution studies to understand microbially mediated formation of a variety of sulfide minerals across a range of natural environments.

  13. Synthesis of rare earth sulfides and their UV-vis absorption spectra

    Institute of Scientific and Technical Information of China (English)

    YUAN Haibin; ZHANG Jianhui; YU Ruijin; SU Qiang

    2009-01-01

    Rare earth sulfides were systematically synthesized via the sulfurization of their commercial oxide powders using CS2 gas to shorten sulfurization time, and their UV-vis absorption spectra were investigated. The appropriate sulfurization conditions were studied. For the rare earth sulfides with the same crystal structure, the sulfurization temperature showed increasing tendency with the decrease of rare earth element atomic radii. The UV-vis absorption spectra of rare earth sulfides did not depend on the crystal structure of rare earth sulfides, but on the 4f electronic structure of rare earth element. The data showed that the optical band gaps of rare earth sulfides were irregular, and the values ranged from 1.65 to 3.75 eV.

  14. Reliability of Electrochemical Techniques for Determining Corrosion Rates on Carbon Steel in Sulfide Media

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel; Hemmingsen, T.; Nielsen, Lars Vendelbo;

    2007-01-01

    Effects of film formation on carbon steel in hydrogen sulfide (H2S) media may corrupt corrosion rate monitoring by electrochemical techniques. Electrochemical data from H2S solutions, biological sulfide media, and natural sulfide containing geothermal water have been collected, and the process...... of film formation in sulfide solutins was followed by video. It can be shown that capacitative and diffusional effects due to porous reactive deposits tend to dominate the data, resulting in unreliable corrosion rates measured using electrochemical techniques. The effect is strongly increased...... if the biofilm in combination with ferrous sulfide corrosion products cover the steel surface. Corrosion rates can be overestimated by a factor of 10 to 100 with electrochemical techniques - both by linear polarization resistance (LPR) and electrochemicel impedance spectroscopy (EIS). Oxygen entering the system...

  15. Hydrogen sulfide intervention in focal cerebral ischemia/reperfusion injury in rats.

    Science.gov (United States)

    Li, Xin-Juan; Li, Chao-Kun; Wei, Lin-Yu; Lu, Na; Wang, Guo-Hong; Zhao, Hong-Gang; Li, Dong-Liang

    2015-06-01

    The present study aimed to explore the mechanism underlying the protective effects of hydrogen sulfide against neuronal damage caused by cerebral ischemia/reperfusion. We established the middle cerebral artery occlusion model in rats via the suture method. Ten minutes after middle cerebral artery occlusion, the animals were intraperitoneally injected with hydrogen sulfide donor compound sodium hydrosulfide. Immunofluorescence revealed that the immunoreactivity of P2X7 in the cerebral cortex and hippocampal CA1 region in rats with cerebral ischemia/reperfusion injury decreased with hydrogen sulfide treatment. Furthermore, treatment of these rats with hydrogen sulfide significantly lowered mortality, the Longa neurological deficit scores, and infarct volume. These results indicate that hydrogen sulfide may be protective in rats with local cerebral ischemia/reperfusion injury by down-regulating the expression of P2X7 receptors.

  16. Influence of sulfides on the tribological properties of composites produced by pulse electric current sintering

    Institute of Scientific and Technical Information of China (English)

    Seung Ho Kim

    2014-01-01

    Self-lubricating Al2O3-15wt%ZrO2 composites with sulfides, such as molybdenum disulfide (MoS2) and tungsten disulfide (WS2) serving as solid lubricants, were fabricated by using the pulse electric current sintering (PECS) technique. The coefficient of friction (COF) of the Al2O3-15wt%ZrO2 composite without/with sulfides was in the range of 0.37-0.48 and 0.27-0.49, respectively. As the amount of sul-fides increased, the COF and the wear rate decreased. The reduction in COF and wear rate of the sulfide-containing composite is caused by a reduction in shear stresses between the specimen and the tribological medium due to the formation of a lubricating film resulting from the lamellar structure of sulfides located on the worn surface.

  17. A NEW BIOGENIC SULFIDE CHEMICAL SENSOR FOR MARINE ENVIRONMENTAL MONITORING AND SURVEY

    Institute of Scientific and Technical Information of China (English)

    宋金明; 赵卫东

    2001-01-01

    A new convenient sulfide electrochemical sensor for marine environmental insitumonitoring and real time survey was developed. The new sensor based on a solid Ag2 S membrane electrode has outstanding chemical sensitivity and stability. It responds to the activity of sulfide ions according to a Nernsfian slope of - 31mV/decade. The sensor can be used to determine the total concentration of sulfides ( CT ) by calibrating the pH value of the solution to a standard pH. The practical measurement range for total sulfide concentration is 0.1 - 10 mg/L in seawater. The sensor has a very low potential drift ( < 4mV) during two months in 0.1 mg/L sulfide seawater. This paper describes the preparation of the sensitive membrane and some main properties of the sensor.

  18. A NEW BIOGENIC SULFIDE CHEMICAL SENSOR FOR MARINE ENVIRONMENTAL MONITORING AND SURVEY

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A new convenient sulfide electrochemical sensor for marine environmental in-situ monitoring and real time survey was developed. The new sensor based on a solid Ag2S membrane electrode has outstanding chemical sensitivity and stability. It responds to the activity of sulfide ions according to a Nernstian slope of -31mV/decade. The sensor can be used to determine the total concentration of sulfides (CT) by calibrating the pH value of the solution to a standard pH. The practical measurement range for total sulfide concentration is 0.1-10 mg/L in seawater. The sensor has a very low potential drift (<4mV) during two months in 0.1 mg/L sulfide seawater. This paper describes the preparation of the sensitive membrane and some main properties of the sensor.

  19. Influence of sulfides on the tribological properties of composites produced by pulse electric current sintering

    Science.gov (United States)

    Kim, Seung Ho

    2014-01-01

    Self-lubricating Al2O3-15wt% ZrO2 composites with sulfides, such as molybdenum disulfide (MoS2) and tungsten disulfide (WS2) serving as solid lubricants, were fabricated by using the pulse electric current sintering (PECS) technique. The coefficient of friction (COF) of the Al2O3-15wt% ZrO2 composite without/with sulfides was in the range of 0.37-0.48 and 0.27-0.49, respectively. As the amount of sulfides increased, the COF and the wear rate decreased. The reduction in COF and wear rate of the sulfide-containing composite is caused by a reduction in shear stresses between the specimen and the tribological medium due to the formation of a lubricating film resulting from the lamellar structure of sulfides located on the worn surface.

  20. Anoxic Transformations of Radiolabeled Hydrogen-Sulfide in Marine and Fresh-Water Sediments

    DEFF Research Database (Denmark)

    ELSGAARD, L.; JØRGENSEN, BB

    1992-01-01

    oxidation to sulfate. Thiosulfate was partly turned over by oxidation or disproportionation and was found to be an intermediate in the (SO4=)-S-35 formation. The results demonstrate that oxidative and reductive sulfur cycling may occur simultaneously in marine and freshwater sediments. When added......Radiolabeled hydrogen sulfide (HS-)-S-35 was used to trace the anoxic sulfur transformations in marine and freshwater sediment slurries. Time course studies consistently showed a rapid (S2O3=)-S-35 formation and a progressive accumulation of (SO4=)-S-35 and thus indicated an anoxic sulfide...... as exogenous oxidant, nitrate (NO3-) stimulated the anoxic sulfide oxidation to sulfate. Ferric iron, added in the form of lepidocrocite (gamma-FeOOH), caused the precipitation of iron sulfides and only partial sulfide oxidation to pyrite and elemental sulfur....