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1

Sulfur compounds in coal  

NASA Technical Reports Server (NTRS)

The literature on the chemical structure of the organic sulfur compounds (or functional groups) in coal is reviewed. Four methods were applied in the literature to study the sulfur compounds in coal: direct spectrometric and chemical analysis, depolymerization in drastic conditions, depolymerization in mild conditions, and studies on simulated coal. The data suggest that most of the organic sulfur in coal is in the form of thiophenic structures and aromatic and aliphatic sulfides. The relative abundance of the sulfur groups in bituminous coal is estimated as 50:30:20%, respectively. The ratio changes during processing and during the chemical analysis. The main effects are the transformation during processing of sulfides to the more stable thiophenic compounds and the elimination of hydrogen sulfide.

Attar, A.; Corcoran, W. H.

1977-01-01

2

Sulfur and sulfur compounds in plant defence.  

PubMed

The multiplicity of chemical structures of sulfur containing compounds, influenced in part by the element's several oxidation states, directly results in diverse modes of action for sulfur-containing natural products synthesized as secondary metabolites in plants. Sulfur-containing natural products constitute a formidable wall of defence against a wide range of pathogens and pests. Steady progress in the development of new technologies have advanced research in this area, helping to uncover the role of such important plant defence molecules like endogenously-released elemental sulphur, but also deepening current understanding of other better-studied compounds like the glucosinolates. As studies continue in this area, it is becoming increasingly evident that sulfur and sulfur compounds play far more important roles in plant defence than perhaps previously suspected. PMID:22545416

Nwachukwu, Ifeanyi D; Slusarenko, Alan J; Gruhlke, Martin C H

2012-03-01

3

Thiophenic Sulfur Compounds Released During Coal Pyrolysis.  

PubMed

Thiophenic sulfur compounds are released during coal gasification, carbonization, and combustion. Previous studies indicate that thiophenic sulfur compounds degrade very slowly in the environment, and are more carcinogenic than polycyclic aromatic hydrocarbons and nitrogenous compounds. Therefore, it is very important to study the principle of thiophenic sulfur compounds during coal conversion, in order to control their emission and promote clean coal utilization. To realize this goal and understand the formation mechanism of thiophenic sulfur compounds, this study focused on the release behavior of thiophenic sulfur compounds during coal pyrolysis, which is an important phase for all coal thermal conversion processes. The pyrolyzer (CDS-5250) and gas chromatography-mass spectrometry (Focus GC-DSQII) were used to analyze thiophenic sulfur compounds in situ. Several coals with different coal ranks and sulfur contents were chosen as experimental samples, and thiophenic sulfur compounds of the gas produced during pyrolysis under different temperatures and heating rates were investigated. Levels of benzothiophene and dibenzothiophene were obtained during pyrolysis at temperatures ranging from 200°C to 1300°C, and heating rates ranging from 6°C/ms to 14°C/ms and 6°C/s to 14°C/s. Moreover, the relationship between the total amount of benzothiophene and dibenzothiophene released during coal pyrolysis and the organic sulfur content in coal was also discussed. This study is beneficial for understanding the formation and control of thiophenic sulfur compounds, since it provides a series of significant results that show the impact that operation conditions and organic sulfur content in coal have on the amount and species of thiophenic sulfur compounds produced during coal pyrolysis. PMID:23781126

Xing, Mengwen; Kong, Jiao; Dong, Jie; Jiao, Haili; Li, Fan

2013-06-01

4

Ambient Air Monitoring for Sulfur Compounds  

ERIC Educational Resources Information Center

A literature review of analytical techniques available for the study of compounds at low concentrations points up some of the areas where further research is needed. Compounds reviewed are sulfur dioxide, sulfuric acid, ammonium sulfate and bisulfate, metal sulfates, hydrogen sulfide, and organic sulfides. (BL)

Forrest, Joseph; Newman, Leonard

1973-01-01

5

Heterogeneous photocatalytic reactions of sulfur aromatic compounds.  

PubMed

Sulfur aromatic compounds, such as mono-, di-, tri-, and tetraalkyl-substituted thiophene, benzothiophenes, dibenzothiophenes, are the molecular components of many fossils (petroleum, oil shale, tar sands, bitumen). Structural units of natural, cross-linked heteroaromatic polymers present in brown coals, turf, and soil are similar to those of sulfur aromatic compounds. Many sulfur aromatic compounds are found in the streams of petroleum refining and upgrading (naphthas, gas oils) and in the consumer products (gasoline, diesel, jet fuels, heating fuels). Besides fossils, the structural fragments of sulfur aromatic compounds are present in molecules of certain organic semiconductors, pesticides, small molecule drugs, and in certain biomolecules present in human body (pheomelanin pigments). Photocatalysis is the frontier area of physical chemistry that studies chemical reactions initiated by absorption of photons by photocatalysts, that is, upon electronic rather than thermal activation, under "green" ambient conditions. This review provides systematization and critical review of the fundamental chemical and physicochemical information on heterogeneous photocatalysis of sulfur aromatic compounds accumulated in the last 20-30 years. Specifically, the following topics are covered: physicochemical properties of sulfur aromatic compounds, major classes of heterogeneous photocatalysts, mechanisms and reactive intermediates of photocatalytic reactions of sulfur aromatic compounds, and the selectivity of these reactions. Quantum chemical calculations of properties and structures of sulfur aromatic compounds, their reactive intermediates, and the structure of adsorption complexes formed on the surface of the photocatalysts are also discussed. PMID:21809426

Samokhvalov, Alexander

2011-11-18

6

Metabolic Reactions among Organic Sulfur Compounds  

NASA Technical Reports Server (NTRS)

Sulfur is central to the metabolisms of many organisms that inhabit extreme environments. Numerous authors have addressed the energy available from a variety of inorganic sulfur redox pairs. Less attention has been paid, however, to the energy required or gained from metabolic reactions among organic sulfur compounds. Work in this area has focused on the oxidation of alkyl sulfide or disulfide to thiol and formaldehyde, e.g. (CH3)2S + H2O yields CH3SH + HCHO + H2, eventually resulting in the formation of CO2 and SO4(-2). It is also found that reactions among thiols and disulfides may help control redox disequilibria between the cytoplasm and the periplasm. Building on our earlier efforts for thiols, we have compiled and estimated thermodynamic properties for alkyl sulfides. We are investigating metabolic reactions among various sulfur compounds in a variety of extreme environments, ranging from sea floor hydrothermal systems to organic-rich sludge. Using thermodynamic data and the revised HKF equation of state, along with constraints imposed by the geochemical environments sulfur-metabolizing organisms inhabit, we are able to calculate the amount of energy available to these organisms.

Schulte, M.; Rogers, K.

2005-01-01

7

[Analysis of sulfur compounds in residue fluid catalytic cracking gasoline].  

PubMed

Sulfur compounds in residue fluid catalytic cracking (RFCC) gasolines from Refinery of SINOPEC Beijing Yanshan Company and Refinery of Shijiazhuang were analyzed by gas chromatograph connected with flame photometric detector (FPD) and atomic emission detector (AED). Twelve and 26 kinds of sulfur compounds were detected by AED in RFCC gasolines from Yanshan and Shijiazhuang respectively. Only 0 and 19 kinds of sulfur compounds were found by FPD in these two gasolines respectively. The experimental results demonstrated that AED is more sensitive and selective to sulfur compounds than FPD. It also indicated that thiophenes were the major sulfur compounds in the RFCC gasoline. In addition, mercaptan, sulfoether and disulfide species were found. PMID:12541959

Liang, Yong-mei; Liu, Wen-hui; Liu, Yao-fang

2002-05-01

8

MANUAL METHOD FOR MEASUREMENT OF REDUCED SULFUR COMPOUNDS  

EPA Science Inventory

A manual method for measuring reduced sulfur compounds in Kraft pulp mill and sulfur recovery plant emissions was evaluated. The method involves removing SO2 from the gas stream (if present) with a citric acid-potassium citrate buffer, that passes reduced sulfur compounds; therma...

9

Modulation of volatile sulfur compounds by wine yeast  

Microsoft Academic Search

Sulfur compounds in wine can be a ‘double-edged sword’. On the one hand, certain sulfur-containing volatile compounds such\\u000a as hydrogen sulfide, imparting a rotten egg-like aroma, can have a negative impact on the perceived quality of the wine, and\\u000a on the other hand, some sulfur compounds such as 3-mercaptohexanol, imparting fruitiness, can have a positive impact on wine\\u000a flavor and

J. H. Swiegers; I. S. Pretorius

2007-01-01

10

Oxidation of nauseous sulfur compounds by photocatalysis or photosensitization  

Microsoft Academic Search

Reduced sulfur compounds such as methanethiol (MSH), dimethylsulfide (DMS) and dimethydisulfide (DMDS) are nauseous by-products produced by a great number of industrial processes. Oxidation of these reduced sulfur compounds in polluted atmospheres and hence the decrease of their harmful and malodorous effects is thus a matter of concern in numerous industrial and water treatment plants. Photocatalytic treatment of gaseous flow

C. Cantau; S. Larribau; T. Pigot; M. Simon; M. T. Maurette; S. Lacombe

2007-01-01

11

Sulfur and Sulfuric Acid  

NASA Astrophysics Data System (ADS)

Sulfur is one of the few elements that is found in its elemental form in nature. Typical sulfur deposits occur in sedimentary limestone/gypsum formations, in limestone/anhydrite formations associated with salt domes, or in volcanic rock.1 A yellow solid at normal temperatures, sulfur becomes progressively lighter in color at lower temperatures and is almost white at the temperature of liquid air. It melts at 114-119°C (depending on crystalline form) to a transparent light yellow liquid as the temperature is increased. The low viscosity of the liquid begins to rise sharply above 160°C, peaking at 93 Pa·s at 188°C, and then falling as the temperature continues to rise to its boiling point of 445°C. This and other anomalous properties of the liquid state are due to equilibria between the various molecular species of sulfur, which includes small chains and rings.

D'Aquin, Gerard E.; Fell, Robert C.

12

[Influence of exogenous sulfur-containing compounds on the exchange fluxes of volatile organic sulfur compounds].  

PubMed

The influences of cysteine, sodium sulfide (Na2S) and sodium sulfate (Na2SO4) on the soil-air exchange fluxes of volatile organic sulfur compounds (VOSCs), including carbonyl sulfide (COS), dimethyl sulfide (DMS), carbon disulfide (CS2) and dimethyl disulfide (DMDS), were studied employing static chamber enclosure followed by laboratory determination using an Entech 7100 preconcentrator coupled with an Agilent 5973 GC-MSD. The results showed that after the addition of cysteine, the soil for the exchange fluxes of COS and CS2 shifted to be the source from sink and the emissions of DMS and DMDS increased significant. The emission amount of DMS and CS2 accounted for 89.2% to the total VOSCs after the addition of cysteine, implying that cysteine is an important precursor for DMS and CS2 in the soil. The amount of DMDS accounted for 93.2% to the total sulfur from the soil after addition of Na2S, indicating that Na2S is a key precursor for DMDS. No significant difference of VOSCs fluxes was found between the controlled soil and the soil with addition of Na2SO4, suggesting Na2SO4 was not the direct precursor for VOSCs in soil. VOSCs exchange rates reached the maximum at 6 to 8 days after addition of cysteine. As for addition of Na2S, the maximal emission rates of different VOSCs appeared at different dates, and the dates differed significantly from those after addition of cysteine, implying that the formation process of VOSCs from the soil with addition of Na2S was more complex and different from the soil with addition of cysteine. PMID:22619943

Yi, Zhi-Gang; Wang, Xin-Ming

2011-08-01

13

A Systematic Presentation of Organic Phosphorus and Sulfur Compounds.  

ERIC Educational Resources Information Center

Because the names, interrelations, and oxidation levels of the organic compounds of phosphorus and sulfur tend to confuse students, a simple way to organize these compounds has been developed. The system consists of grouping them by oxidation state and extent of carbon substitution. (JN)

Hendrickson, James B.

1985-01-01

14

Antioxidant combinations of molybdenum complexes and organic sulfur compounds for lubricating oils  

SciTech Connect

An antioxidant additive combination for lubricating oils is prepared by combining (a) a sulfur containing molybdenum compound prepared by reacting an ammonium tetrathiomolybdate, and a basic nitrogen compound, with (b) an organic sulfur compound.

deVries, L.; King, J.M.

1983-09-06

15

Uses of lunar sulfur  

NASA Technical Reports Server (NTRS)

Sulfur and sulfur compounds have a wide range of applications for their fluid, electrical, chemical, and biochemical properties. Although known abundances on the Moon are limited (approximately 0.1 percent in mare soils), sulfur is relatively extractable by heating. Coproduction of sulfur during oxygen extraction from ilmenite-rich mare soils could yield sulfur in masses up to 10 percent of the mass of oxygen produced. Sulfur deserves serious consideration as a lunar resource.

Vaniman, D.; Pettit, D.; Heiken, G.

1992-01-01

16

Isotope exchange reactions with radiolabeled sulfur compounds in anoxic seawater  

Microsoft Academic Search

The isotope exchange between35S-labeled sulfur compounds of sulfate (SO42-), elemental sulfur (S0), polysulfide (Sn2-), hydrogen sulfide (SHS-: H2S + HS- + S2-), iron sulfide (FeS), and pyrite (FeS2) was studied at pH 7.6 and 20 °C in anoxic, sterile seawater. Isotope exchange was observed between S0, S22- SHS-, and FeS, but not between35S labeled SO42- or FeS2 and the other

Henrik Fossing; Bo Ba Jørgensen

1990-01-01

17

[Determination of sulfur compounds in fluid catalytic cracking gasoline by gas chromatography with a sulfur chemiluminescence detector].  

PubMed

A method for the separation and determination of sulfur compounds in fluid catalytic cracking gasoline (FCC gasoline) by gas chromatography with a sulfur chemiluminescence detector (GC-SCD) was established. Fifty eight sulfur compounds including mercaptan, sulfide, disulfide, thiophene, alkyl thiophenes, benzothiophene and alkyl benzothiophenes were identified based on their retention indexes and the data obtained from gas chromatography with an atomic emission detector (GC-AED). The effects of flow rate of carrier gas and oven temperature were discussed. Detection reproducibilities of main sulfur compounds (thiophene, n-butyl mercaptan, 2-methylthiophene, 3-methylthiophene, 2,4-dimethylthiophene) in FCC gasoline were satisfactory (RSDs were no more than 5.0%) and detection limit for sulfur was 0.1 mg/L. Using thiophene and benzothiophene as testing samples, it was determined that response factor was independent of the molecular structure of sulfur compounds. The linear range was 0.5-800.0 mg/L sulfur with a correlation coefficient of 0.999. PMID:15712900

Yang, Yongtan; Wang, Zheng; Zong, Baoning; Yang, Haiying

2004-05-01

18

Emission of volatile sulfur compounds from spruce trees  

SciTech Connect

Spruce (Picea abies L.) trees from the same clone were supplied with different, but low, amounts of plant available sulfate in the soil (9.7-18.1 milligrams per 100 grams of soil). Branches attached to the trees were enclosed in a dynamic gas exchange cuvette and analyzed for the emission of volatile sulfur compounds. Independent of the sulfate supply in the soil, H{sub 2}S was the predominant reduced sulfur compound continuously emitted from the branches with high rates during the day and low rates in the night. In the light, as well as in the dark, the rates of H{sub 2}S emission increased exponentially with increasing water vapor flux from the needles. Approximately 1 nanomole of H{sub 2}S was found to be emitted per mole of water. When stomata were closed completely, only minute emission of H{sub 2}S was observed. Apparently, H{sub 2}S emission from the needles is highly dependent on stromatal aperture, and permeation through the cuticle is negligible. In several experiments, small amounts of dimethylsulfide and carbonylsulfide were also detected in a portion of the samples. However, SO{sub 2} was the only sulfur compound consistently emitted from branches of spruce trees in addition to H{sub 2}S. Emission of SO{sub 2} mainly proceeded via an outburst starting before the beginning of the light period. The total amount of SO{sub 2} emitted from the needles during this outburst was correlated with the plant available sulfate in the soil. The diurnal changes in sulfur metabolism that may result in an outburst of SO{sub 2} are discussed.

Rennenberg, H.; Huber, B.; Schroeder, P.; Stahl, K.; Haunold, W.; Georgil, H.W.; Slovik, S.; Pfanz, H. (Fraunhofer Institut fuer Atmosphaerische Umweltforschung, Garmisch-Partenkirchen (West Germany))

1990-03-01

19

The role of labile sulfur compounds in thermochemical sulfate reduction  

USGS Publications Warehouse

The reduction of sulfate to sulfide coupled with the oxidation of hydrocarbons to carbon dioxide, commonly referred to as thermochemical sulfate reduction (TSR), is an important abiotic alteration process that most commonly occurs in hot carbonate petroleum reservoirs. In the present study we focus on the role that organic labile sulfur compounds play in increasing the rate of TSR. A series of gold-tube hydrous pyrolysis experiments were conducted with n-octane and CaSO4 in the presence of reduced sulfur (e.g. H2S, S??, organic S) at temperatures of 330 and 356 ??C under a constant confining pressure. The in-situ pH was buffered to 3.5 (???6.3 at room temperature) with talc and silica. For comparison, three types of oil with different total S and labile S contents were reacted under similar conditions. The results show that the initial presence of organic or inorganic sulfur compounds increases the rate of TSR. However, organic sulfur compounds, such as 1-pentanethiol or diethyldisulfide, were significantly more effective in increasing the rate of TSR than H2S or elemental sulfur (on a mole S basis). The increase in rate is achieved at relatively low concentrations of 1-pentanethiol, less than 1 wt% of the total n-octane, which is comparable to the concentration of organic S that is common in many oils (???0.3 wt%). We examined several potential reaction mechanisms to explain the observed reactivity of organic LSC. First, the release of H2S from the thermal degradation of thiols was discounted as an important mechanism due to the significantly greater reactivity of thiol compared to an equivalent amount of H2S. Second, we considered the generation of olefines in association with the elimination of H2S during thermal degradation of thiols because olefines are much more reactive than n-alkanes during TSR. In our experiments, olefines increased the rate of TSR, but were less effective than 1-pentanethiol and other organic LSC. Third, the thermal decomposition of organic LSC creates free-radicals that in turn might initiate a radical chain-reaction that creates more reactive species. Experiments involving radical initiators, such as diethyldisulfide and benzyldisulfide, did not show an increase in reactivity compared to 1-pentanethiol. Therefore, we conclude that none of these can sufficiently explain our observations of the initial stages of TSR; they may, however, be important in the later stages. In order to gain greater insight into the potential mechanism for the observed reactivity of these organic sulfur compounds during TSR, we applied density functional theory-based molecular modeling techniques to our system. The results of these calculations indicate that 1-pentanethiol or its thermal degradation products may directly react with sulfate and reduce the activation energy required to rupture the first S-O bond through the formation of a sulfate ester. This study demonstrates the importance of labile sulfur compounds in reducing the onset timing and temperature of TSR. It is therefore essential that labile sulfur concentrations are taken into consideration when trying to make accurate predictions of TSR kinetics and the potential for H2S accumulation in petroleum reservoirs. ?? 2008.

Amrani, A.; Zhang, T.; Ma, Q.; Ellis, G.S.; Tang, Y.

2008-01-01

20

Removal of Sulfur Compounds from Coal by the Thermophilic Organism Sulfolobus acidocaldarius  

PubMed Central

The thermophilic, reduced-sulfur, iron-oxidizing bacterium Sulfolobus acidocaldarius was used for the removal of sulfur compounds from coal. The inclusion of complex nutrients such as yeast extract and peptone, and chemical oxidizing agents, 0.01 M FeCl3 into leaching medium, reduced the rate and the extent of sulfur removal from coal. The rate of sulfur removal by S. acidocaldarius was strongly dependent on the sulfur content of the coal and on the total external surface area of coal particles. Approximately 96% of inorganic sulfur was removed from a 5% slurry of coal which had an initial total sulfur content of 4% and an inorganic (pyritic S and sulfate) sulfur content of 2.1%. This resulted in removal of 50% of initial total sulfur present in coal. PMID:16346112

Kargi, Fikret; Robinson, James M.

1982-01-01

21

Effects of inorganic sulfur addition on fluxes of volatile sulfur compounds in Sphagnum peatlands  

NASA Technical Reports Server (NTRS)

Short and long-term impacts of increased S deposition on fluxes of volatile S compounds (VSC's) from Sphagnum peatlands were investigated in an artificially acidified (sulfuric and nitric acids) poor fen (Mire 239) at the Experimental Lakes Area (ELA), Ontario, Canada. Additional experiments were conducted in a poor fen (Sallie's Fen) in Barrington, NH, USA. At Mire 239, emissions of VSC's were monitored, before and after acidification, at control (unacidified) and experimental sections within two major physiographic zones of the mire (oligotrophic and minerotrophic). The experimental segments of the mire received S amendments since 1983, in amounts equivalent to the annual S deposition in the highest polluted areas of Canada and U.S. Dimethyl sulfide (DMS) was the predominant VSC released from the mire and varied largely with time and space (i.e., from 2.5 to 127 nmol/m(sup -2)h(sup -1)). Sulfur addition did not affect DMS emissions in a period of hours to a few days, although it stimulated production of DMS and MSH in the anoxic surficial regions of the peat. DMS emissions in the experimental oligotrophic segment of the mire was approximately 3-fold greater than in the control oligotrophic segment, and approximately 10-fold greater than in the minerotrophic zones. These differences could be due to a combination of differences in types of vegetation, nutritional status, and S input. At Sallie's Fen, DMS fluxes were approximately 8 times higher from a Sphagnum site than from a bare peat site. Fluxes of VSC's were not significantly affected by sulfate amendments at both sites, while DMS and MSH concentrations increases greatly with time in the top 10 cm of the peat column. Our data indicated that although Sphagnum is not the direct source of DMS released from Sphagnum peatlands, it might play a role in regulating DMS emissions to the atmosphere.

Demello, William Zamboni; Hines, Mark E.; Bayley, Suzanne E.

1992-01-01

22

Identification and origin of odorous sulfur compounds in cooked ham.  

PubMed

The aim of this work was to identify and gain further knowledge on the origin of sulfur compounds present in the volatile fraction of cooked ham, and on their role in the aroma of this product. To this end, we performed analyses by one- and two-dimensional gas chromatography coupled with mass spectrometry, and olfactometry. Among the odorant sulfur compounds identified, three furans present in trace amounts proved to have very intense odours responsible for the "meaty, cooked ham" notes of this pork product. They were 2-methyl-3-furanthiol, 2-methyl-3-(methyldithio)furan and bis(2-methyl-3-furyl) disulphide. Addition of thiamine or cysteine also enabled us to study the effect of these odour precursors on the formation of odorant furans during the cooking of ham. The results revealed a direct link between the thermal degradation of thiamine and the formation of these compounds. By contrast, addition of cysteine in the presence of fructose or xylose did not appreciably increase their production. PMID:24594176

Thomas, Caroline; Mercier, Frédéric; Tournayre, Pascal; Martin, Jean-Luc; Berdagué, Jean-Louis

2014-07-15

23

Portable instrument and method for detecting reduced sulfur compounds in a gas  

DOEpatents

A portable real time instrument for detecting concentrations in the part per billion range of reduced sulfur compounds in a sample gas. Ozonized air or oxygen and reduced sulfur compounds in a sample gas stream react to produce chemiluminescence in a reaction chamber and the emitted light is filtered and observed by a photomultiplier to detect reduced sulfur compounds. Selective response to individual sulfur compounds is achieved by varying reaction chamber temperature and ozone and sample gas flows, and by the use of either air or oxygen as the ozone source gas.

Gaffney, J.S.; Kelly, T.J.; Tanner, R.L.

1983-06-01

24

Methylated sulfur compounds in microbial mats: in situ concentrations and metabolism by a colorless sulfur bacterium.  

PubMed Central

The concentrations of the volatile organic sulfur compounds methanethiol, dimethyl disulfide, and dimethyl sulfide (DMS) and the viable population capable of DMS utilization in laminated microbial ecosystems were evaluated. Significant levels of DMS and dimethyl disulfide (maximum concentrations of 220 and 24 nmol cm3 of sediment-1, respectively) could be detected only at the top 20 mm of the microbial mat, whereas methanethiol was found only at depth horizons from 20 to 50 mm (maximum concentration of 42 nmol cm3 of sediment-1). DMS concentrations in the surface layer doubled after cold hydrolysis of its precursor, dimethylsulfoniopropionate. Most-probable-number counts revealed 2.2 x 10(5) cells cm3 of sediment-1, in the 0- to 5-mm depth horizon, capable of growth on DMS as the sole source of energy. An obligately chemolithoautotrophic bacillus designated strain T5 was isolated from the top layer of the marine sediment. Continuous culture studies in which DMS was the growth-limiting substrate revealed a maximum specific growth rate of 0.10 h-1 and a saturation constant of 90 mumol liter-1 for aerobic growth on this substrate. PMID:1872604

Visscher, P T; Quist, P; van Gemerden, H

1991-01-01

25

Degradation of organic sulfur compounds by a coal-solubilizing fungus  

SciTech Connect

Paecilomyces sp. TLi, a coal-solubilizing fungus, was shown to degrade organic sulfur-containing coal substructure compounds. Dibenzothiophene was degraded via a sulfur-oxidizing pathway to 2,2{prime}-dihydroxybiphenyl. No further metabolism of that compound was observed. Ethyl phenyl sulfide and diphenyl sulfide were degraded to the corresponding sulfones. A variety of products were formed from dibenzyl sulfide, presumably via free radical intermediates. Diphenyl disulfide and dibenzyl disulfide were cleaved to the corresponding thiols and other single-ring products. It was concluded that degradation of organic sulfur compounds by Paecilomyces involves an oxidative attack localized at the sulfur atom.

Faison, B.D.; Lewis, S.N.; Ma, C.Y.; Woodward, C.A. [Oak Ridge National Lab., TN (United States); Clark, T.M. [Univ. of Detroit, MI (United States); Sharkey, D.M. [California Polytechnic Univ., San Luis Obispo, CA (United States)

1991-12-31

26

Lunar sulfur  

NASA Technical Reports Server (NTRS)

Ideas introduced by Vaniman, Pettit and Heiken in their 1988 Uses of Lunar Sulfur are expanded. Particular attention is given to uses of SO2 as a mineral-dressing fluid. Also introduced is the concept of using sulfide-based concrete as an alternative to the sulfur-based concretes proposed by Leonard and Johnson. Sulfur is abundant in high-Ti mare basalts, which range from 0.16 to 0.27 pct. by weight. Terrestrial basalts with 0.15 pct. S are rare. For oxygen recovery, sulfur must be driven off with other volatiles from ilmenite concentrates, before reduction. Troilite (FeS) may be oxidized to magnetite (Fe3O4) and SO2 gas, by burning concentrates in oxygen within a magnetic field, to further oxidize ilmenite before regrinding the magnetic reconcentration. SO2 is liquid at -20 C, the mean temperature underground on the Moon, at a minimum of 0.6 atm pressure. By using liquid SO2 as a mineral dressing fluid, all the techniques of terrestrial mineral separation become available for lunar ores and concentrates. Combination of sulfur and iron in an exothermic reaction, to form iron sulfides, may be used to cement grains of other minerals into an anhydrous iron-sulfide concrete. A sulfur-iron-aggregate mixture may be heated to the ignition temperature of iron with sulfur to make a concrete shape. The best iron, sulfur, and aggregate ratios need to be experimentally established. The iron and sulfur will be by-products of oxygen production from lunar minerals.

Kuck, David L.

1991-01-01

27

Laser spectroscopy on volatile sulfur compounds: possibilities for breath analysis.  

PubMed

There is an emerging interest in the detection of volatile sulfur compounds (VSCs) in the breath environment, given their biological relevance as potential signatures of several pathological conditions. Particularly, laser-based spectroscopic sensors are candidates for conducting accurate breath diagnostics in clinical settings. With these aims in mind, the current status of VSC sensing via laser absorption spectroscopy is reviewed in this paper. Attention has been focused on the most promising exhaled markers of pathological conditions, namely hydrogen sulfide, carbonyl sulfide, methanethiol, carbon disulfide and dimethyl sulfide. Details of the most relevant spectroscopic studies conducted on such molecules are presented, together with suggestions on the future direction of this challenging analytical field. PMID:21593551

Ciaffoni, L; Peverall, R; Ritchie, G A D

2011-06-01

28

Sulfuric odorous compounds emitted from pig-feeding operations  

NASA Astrophysics Data System (ADS)

The objective of the study was to quantify the concentration and emission levels of sulfuric odorous compounds emitted from pig-feeding operations. Five types of pig-housing rooms were studied: gestation, farrowing, nursery, growing and fattening rooms. The concentration range of sulfuric odorous compounds in these pig-housing rooms were 30-200 ppb for hydrogen sulfide (H 2S), 2.5-20 ppb for methyl mercaptan (CH 3SH), 1.5-12 ppb for dimethyl sulfide (DMS; CH 3SCH 3) and 0.5-7 ppb for dimethyl disulfide (DMDS; CH 3S 2CH 3), respectively. The emission rates of H 2S, CH 3SH, DMS and DMDS were estimated by multiplying the average concentration (mg m -3) measured near the air outlet by the mean ventilation rate (m 3 h -1) and expressed either per area (mg m -2 h -1) or animal unit (AU; liveweight of the pig, 500 kg) (mg pig -1 h -1). As a result, the emission rates of H 2S, CH 3SH, DMS and DMDS in the pig-housing rooms were 14-64, 0.8-7.3, 0.4-3.4 and 0.2-1.9 mg m -2 h -1, respectively, based on pig's activity space and 310-723, 18-80, 9-39 and 5-22 mg AU -1 h -1, respectively, based on pig's liveweight, which indicates that their emission rates were similar, whether based upon the pig's activity space or liveweight. In conclusion, the concentrations and emission rates of H 2S were highest in the fattening room followed by the growing, nursery, farrowing and gestation rooms whereas those of CH 3SH, DMS and DMDS concentrations were largest in the growing room followed by the nursery, gestation and farrowing rooms.

Kim, Ki Youn; Ko, Han Jong; Kim, Hyeon Tae; Kim, Yoon Shin; Roh, Young Man; Lee, Cheol Min; Kim, Hyun Soo; Kim, Chi Nyon

29

[Determination of sulfur compounds in catalytic diesel oil by gas chromatography with atomic emission detector and its applications].  

PubMed

The method for separation and determination of sulfur compounds in catalytic diesel oil by gas chromatography with atomic emission detector (GC-AED) was established. More than 130 sulfur compounds (including alkyl thiophenes, benzothiophene, alkyl benzothiophenes, dibenzothiophene, alkyl dibenzothiophenes) in catalytic diesel oil were qualified based on the retention time of some pure sulfur compounds and the retention indexes of sulfur compounds. The effects of oven temperature, heating rate and sample amount on resolution and effective plate number were investigated. Retention indexes of different sulfur compounds under temperature programmed condition were calculated. The relative standard deviations of peak areas of main sulfur compounds in catalytic diesel oil were no more than 5.0%, detection limit for sulfur was 0.1 mg/L under chosen conditions. Because response factor was independent on the molecule structure of the sulfur-containing compound, the content of each sulfur compound was determined quantitatively using thiophene as sulfur standard sample. The linear range was 2 mg/L-1,000 mg/L sulfur, and the correlation coefficient was 0.997. The method is successfully applied for the determination of the contents of sulfur compounds in six different catalytic diesel oils (Fujian catalytic diesel oil, Yanshan catalytic diesel oil, Zhongdong diesel oil, Zhenhai catalytic diesel oil, Zhenhai Changsan oil and Zhenhai Changer oil). Distributions of sulfur compounds in different catalytic diesel oils were obtained by GC-AED. PMID:12682994

Yang, Yong-tan; Yang, Hai-ying; Lu, Wan-zhen

2002-11-01

30

Effect of sulfur and its compounds on the performance of graphite electrooxidation in molten carbonate  

NASA Astrophysics Data System (ADS)

Direct carbon fuel cells are promising power sources with their performance significantly depending on the electrooxidation activity of carbon fuel. The impurities in the carbon fuel may affect the anode reactions. Sulfur and some of its inorganic compounds (CaSO4, K2SO3, K2S, FeS2) were added in molten carbonate and their effect on graphite electrooxidation was investigated. Cyclic voltammograms of gold electrode with addition of these sulfur compounds showed CaSO4 was stable and other compounds were electrochemically oxidized to high valence state sulfur compounds at operating voltage range. Linear sweep voltammetry of graphite with addition of sulfur compounds exhibited enhanced current density compared to pure graphite electrooxidation. Chronoamperometry was carried out to examine steady-state test of graphite electrooxidation in presence of sulfur compounds and the results indicated the enhanced current densities were caused by improved Boudouard reaction for CaSO4 and sulfur electrooxidation for other compounds, respectively. These inorganic sulfur compounds had no impact on electrooxidation process of graphite.

Liu, Jia; Ye, Ke; Du, Mengmeng; Yin, Jinling; Cao, Dianxue; Wang, Guiling

2015-01-01

31

Molecular Spectroscopy by Means of ESCA II. Sulfur compounds. Correlation of electron binding energy with structure  

Microsoft Academic Search

Electron spectra from an extensive series of sulfur compounds have been studied. A correlation has been established between the observed position of inner electron lines of sulfur and structure. The influence of structure on the electron binding energies is discussed in terms of a calculated atomic charge, based on the concepts of electronegativity and partial ionic character of bonds. The

B. J. Lindberg; K. Hamrin; G. Johansson; U. Gelius; A. Fahlman; C. Nordling; K. Siegbahn

1970-01-01

32

A STUDY TO IMPROVE EPA METHODS 15 AND 16 FOR REDUCED SULFUR COMPOUNDS  

EPA Science Inventory

EPA source test methods for reduced sulfur compounds, Method 15 for Claus sulfur recovery plants and Method 16 for Kraft pulp mills have been evaluated, and information is provided for the user. Techniques and procedures for the gas chromatographic measurement of hydrogen sulfide...

33

BIOGENIC SULFUR COMPOUNDS IN COASTAL ATMOSPHERES OF NORTH CAROLINA  

EPA Science Inventory

Atmospheric H2S, SO2, and particulate SO4(-2), Na(+), C1(-), NH4(-), and NO3(-) were measured in two experiments on the North Carolina coast to determine the levels of biogenic sulfur species at marsh and estuarine locations where dissimilatory bacterial sulfate reduction produce...

34

Characterization of malodorous sulfur compounds in landfill gas  

NASA Astrophysics Data System (ADS)

In order to analyze the composition of landfill gas (LFG) with respect to malodorous components, the concentrations of several reduced sulfur compounds (RSC: hydrogen sulfide (H 2S); methyl mercaptan (CH 3SH); dimethyl sulfide ((CH 3) 2S); carbon disulfide (CS 2); and dimethyl disulfide ((CH 3) 2S 2)) were determined from four municipal landfill sites—initialed W, B, H, and N—in Korea. The S gas concentrations measured in these landfill sites were found consistently to be dominated by H 2S, while their absolute mean values tended to change considerably between one inactive site (N) and the others; its mean values were measured from as little as 336 ppb (N site) up to 2340 ppm (H site). Hence, in terms of mass concentration units (mg m -3), H 2S alone generally explained far more than 90% of all S gases determined concurrently. If the relative contribution of RSC to the LFG budget is assessed in relation to major aromatic hydrocarbons (e.g., benzene, toluene, and xylene), the RSC emission appears to comprise a significant proportion as trace components of LFG other than major ones like CH 4 and CO 2.

Kim, Ki-Hyun; Choi, YJ; Jeon, EC; Sunwoo, Young

35

Lithium Polysulfidophosphates: A Family of Lithium-Conducting Sulfur-Rich Compounds for Lithium-Sulfur Batteries  

SciTech Connect

Given the great potential for improving the energy density of state-of-the-art lithium-ion batteries by a factor of 5, a breakthrough in lithium-sulfur (Li-S) batteries will have a dramatic impact in a broad scope of energy related fields. Conventional Li-S batteries that use liquid electrolytes are intrinsically short-lived with low energy efficiency. The challenges stem from the poor electronic and ionic conductivities of elemental sulfur and its discharge products. We report herein lithium polysulfidophosphates (LPSP), a family of sulfur-rich compounds, as the enabler of long-lasting and energy-efficient Li-S batteries. LPSP have ionic conductivities of 3.0 10-5 S cm-1 at 25 oC, which is 8 orders of magnitude higher than that of Li2S (~10-13 S cm-1). The high Li-ion conductivity of LPSP is the salient characteristic of these compounds that impart the excellent cycling performance to Li-S batteries. In addition, the batteries are configured in an all-solid state that promises the safe cycling of high-energy batteries with metallic lithium anodes.

Lin, Zhan [ORNL] [ORNL; Liu, Zengcai [ORNL] [ORNL; Fu, Wujun [ORNL] [ORNL; Dudney, Nancy J [ORNL] [ORNL; Liang, Chengdu [ORNL] [ORNL

2013-01-01

36

Approach for selective separation of thiophenic and sulfidic sulfur compounds from petroleum by methylation/demethylation.  

PubMed

Detailed characterization of petroleum derived sulfur compounds has been challenging, due to the complex composition of the hydrocarbon matrix. A novel method was developed for selective separation of thiophenic and sulfidic compounds from petroleum. Sulfur compounds were methylated to sulfonium salts by AgBF4 and CH3I, then the polar salts were separated by precipitation from petroleum matrix. The thiophenic and sulfidic sulfonium salts were sequentially demethylated with 7-azaindole and 4-dimethylaminopyridine, obtaining original thiophenic and sulfidic compounds, respectively. The method was validated by model compounds, and applied to a diesel and a vacuum distillation petroleum fraction. Sulfur fractions were characterized by gas chromatography (GC) coupled with a sulfur chemiluminescence detector (SCD) and quadrupole mass spectrometry (MS), and high resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). The technique was effective to selectively obtain high-purity thiophenic and sulfidic compounds and showed rare discrimination among sulfur compounds with ranging molecular weights and degrees of unsaturation. The method would facilitate multifaceted detailed characterization of sulfur compounds in an organic complex matrix. PMID:25519193

Wang, Meng; Zhao, Suoqi; Chung, Keng H; Xu, Chunming; Shi, Quan

2015-01-20

37

Kinase regulation by sulfur and selenium containing compounds.  

PubMed

Kinases are enzymes that are involved in a wide-range of cellular targets such as cell proliferation, metabolism, survival and apoptosis. Aberrations in the activity of the kinases have been linked to many human diseases such as diabetes, inflammation and cancer. The discovery of more than 518 kinases encoded by the human genome has spurred the development of rapid screening techniques for potential drugs against these enzymes and these have been identified as interesting targets for medicinal chemistry programs, especially in cancer therapy. On the other hand, sulfur and selenium have been increasingly recognized as essential elements in biology and medicine. Converging data from epidemiological and clinical studies have highlighted these elements as effective chemopreventive agents, particularly against various types of cancer (prostate, lung, breast, leukemia, colon, skin, lymphome, thyroid, pancreas, liver). These elements act through a wide range of potential mechanisms where one identified signal pathway event is kinase modulation, which is common for the two elements and emerges as a valid target. The kinases modulated by sulfur and selenium derivatives include MAP, ERK, JNK, Akt, Cdc2, Cyclin B1 and Cdc25c amongst others. Although both of the elements in question are in the same group in the periodic table and have similar biochemistries, there are relevant differences related to redox potentials, stabilities, oxidation states and anticancer activity. Literature data suggest that the replacement of sulfur by selenium in established cancer chemopreventive agents results in more effective chemopreventive analogs. In view of the multi-target kinase mechanisms in preventing cellular transformation, as well as the differences and similarities between them, in this review we focus on the development of new structures that contain selenium and/or sulfur and discuss our understanding of the regulation of antitumoral effects with emphasis on kinase modulation activity and its implications in cancer. PMID:21395545

Sanmartín, Carmen; Plano, Daniel; Font, María; Palop, Juan Antonio

2011-05-01

38

Microbial degradation of nitrogen, oxygen, and sulfur heterocyclic compounds under anaerobic conditions: Studies with aquifer samples  

Microsoft Academic Search

The potential for anaerobic biodegradation of 12 heterocyclic model compounds was studied. Nine of the model compounds were biotransformed in aquifer slurries under sulfate-reducing or methanogenic conditions. The nitrogen and oxygen heterocyclic compounds were more susceptible to anaerobic biodegradation than those compounds containing a sulfur deteroatom. In contrast, only small amounts of methane were detected in aquifer slurries amended with

Elmar P. Kuhn; Joseph M. Suflita

1989-01-01

39

Biodegradation of organic sulfur compounds in crude oils from Oman  

SciTech Connect

Five closely related crude oils from Oman, showing various degrees of biodegradation ranging from non-biodegraded to severely biodegraded, were quantitatively investigated for free and sulfur-bound hydrocarbons. Hydrocarbons sequestered in the alkylsulfide fraction and the polar fraction were analysed after Raney Ni desulfurisation and subsequent hydrogenation. With increasing degree of biodegradation, pristane (Pr), phytane (Ph) and a series of mid-chain methyl alkanes are enriched relative to the n-alkanes, as evidenced by increased Pr/n-C{sub 17} and Ph/n-C{sub 18} ratios. In the severely biodegraded oil no free n-alkanes, mid-chain alkanes or isoprenoid alkanes could be detected. Sterane and hopane distributions, however, remain unchanged throughout the biodegradation series. Hydrocarbons sequestered in the alkylsulfide fraction (i.e. n-alkanes, mid-chain methyl alkanes, Pr and Ph) are biodegraded at lower rates than the corresponding hydrocarbons in the saturated hydrocarbon fraction. Similar hydrocarbons sequestered in the polar fraction are biodegraded at even lower rates. These results suggest that hydrocarbons bound by a higher amount of sulfur links are biodegraded at a lower rate.

Koopmans, M.P.; Sinninghe Damste, J.S.; Leeuw, J.W. de [Netherlands Institute for Sea Research, Den Burg (Netherlands)

1996-10-01

40

Adsorptive removal of sulfur compounds using IRMOF-3 at ambient temperature  

NASA Astrophysics Data System (ADS)

Zinc-based metal-organic framework (IRMOF-3) was used as adsorbent for removal of dimethyl sulfide, ethyl mercaptan and hydrogen sulfide in fixed bed reactor at ambient temperature. These samples before and after exposure to sulfur compounds were characterized by Fourier transform infrared (FTIR), and X-ray diffraction (XRD), and thermo gravimetric (TG), and X-ray photoelectron spectroscopy (XPS). The results show that IRMOF-3 exhibit the best performance for hydrogen sulfide removal with the highest breakthrough sulfur capacity, followed by ethyl mercaptan and dimethyl sulfide. This is in consistent with the interaction strength between IRMOF-3 and sulfur compounds. In the case of dimethyl sulfide and ethyl mercaptan, the interaction comes from the weak interaction between the amino group in the MOFs and the sulfur atom of the adsorbate. This can also be considered as a hydrogen bond complex in which the amino group in the MOFs and the S atom of the sulfur compounds play the role of H-donor and H-acceptor, respectively. In the case of hydrogen sulfide, the interaction with sulfur atom originates from the amino group and zinc site in the MOFs. The former is more like an acid-base interaction, whereas the latter results in new products of ZnS and H2O and serious destruction of the MOFs.

Wang, Xiao-Ling; Fan, Hui-Ling; Tian, Zhen; He, En-Yun; Li, Ye; Shangguan, Ju

2014-01-01

41

Flash pyrolysis of coal, coal maceral, and coal-derived pyrite with on-line characterization of volatile sulfur compounds  

USGS Publications Warehouse

A Pyroprobe flash pyrolysis-gas chromatograph equipped with a flame photometric detector was used to study volatile sulfur compounds produced during the thermal decomposition of Illinois coal, coal macerals and coal-derived pyrite. Maximum evolution of volatile organic sulfur compounds from all coal samples occurred at a temperature of approximately 700??C. At this temperature, the evolution of thiophene, its alkyl isomers, and short-chain dialkyl sulfide compounds relative to the evolution of benzothiophene and dibenzothiophene compounds was greater from coal high in organic sulfur than from coal low in organic sulfur. The variation in the evolution of sulfur compounds observed for three separate coal macerals (exinite, vitrinite, and inertinite) was similar to that observed for whole coal samples. However, the variation trend for the macerals was much more pronounced. Decomposition of coal-derived pyrite with the evolution of elemental sulfur was detected at a temperature greater than 700??C. The results of this study indicated that the gas chromotographic profile of the volatile sulfur compounds produced during flash pyrolysis of coals and coal macerals varied as a function of the amount of organic sulfur that occurred in the samples. Characterization of these volatile sulfur compounds provides a better understanding of the behavior of sulfur in coal during the thermolysis process, which could be incorporated in the design for coal cleaning using flash pyrolysis techniques. ?? 1988.

Chou, I.-M.; Lake, M.A.; Griffin, R.A.

1988-01-01

42

Spectral reflectance (0.4 - 5.0 microns) of sulfur related compounds and mixtures  

NASA Technical Reports Server (NTRS)

Studied and quantified were: (1) the spectral properties of sulfur related compounds and materials; (2) the effects of thermal history, temperature and mixing ratios on the spectral properties of these materials; and (3) the application of these results to the Jovian system, in particular, the surfaces of Io, Europa, and Amalthea, and the chromophores in the Jovian atmosphere. Major results of the study include: (1) a study of how sulfur deposition affects the band strengths in various silicates; (2) a study of how the ultraviolet absorption band of sulfur is affected by dilution in ice; (3) the application of these two sets of experimental studies to Io, in the case of silicate band strengths, and Europa, as in the case of sulfur dilution in ices.

Gradie, Jonathan C.

1987-01-01

43

Anti-Inflammatory Activity of Sulfur-Containing Compounds from Garlic  

PubMed Central

Abstract We identified four anti-inflammatory sulfur-containing compounds from garlic, and their chemical structures were identified as Z- and E-ajoene and oxidized sulfonyl derivatives of ajoene. The sulfur compounds inhibited the production of nitric oxide (NO) and prostaglandin E2 (PGE2) and the expression of the pro-inflammatory cytokines tumor necrosis factor-?, interleukin-1?, and interleukin-6 in lipopolysaccharide (LPS)-activated macrophages. Western blotting and reverse transcription–polymerase chain reaction analysis demonstrated that these sulfur compounds attenuated the LPS-induced expression of the inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) proteins and mRNA. Moreover, these sulfur-containing compounds suppressed the nuclear factor-?B (NF-?B) transcriptional activity and the degradation of inhibitory-?B? in LPS-activated macrophages. Furthermore, we observed that they markedly inhibited the LPS-induced phosphorylations of p38 mitogen-activated protein kinases and extracellular signal-regulated kinases (ERK) at 20??M. These data demonstrate that the sulfur compounds from garlic, (Z, E)-ajoene and their sulfonyl analogs, can suppress the LPS-induced production of NO/PGE2 and the expression of iNOS/COX-2 genes by inhibiting the NF-?B activation and the phosphorylations of p38 and ERK. Taken together, these data show that Z- and E-ajoene and their sulfonyl analogs from garlic might have anti-inflammatory therapeutic potential. PMID:23057778

Lee, Da Yeon; Li, Hua; Lim, Hyo Jin; Lee, Hwa Jin; Jeon, Raok

2012-01-01

44

Anti-inflammatory activity of sulfur-containing compounds from garlic.  

PubMed

We identified four anti-inflammatory sulfur-containing compounds from garlic, and their chemical structures were identified as Z- and E-ajoene and oxidized sulfonyl derivatives of ajoene. The sulfur compounds inhibited the production of nitric oxide (NO) and prostaglandin E(2) (PGE(2)) and the expression of the pro-inflammatory cytokines tumor necrosis factor-?, interleukin-1?, and interleukin-6 in lipopolysaccharide (LPS)-activated macrophages. Western blotting and reverse transcription-polymerase chain reaction analysis demonstrated that these sulfur compounds attenuated the LPS-induced expression of the inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) proteins and mRNA. Moreover, these sulfur-containing compounds suppressed the nuclear factor-?B (NF-?B) transcriptional activity and the degradation of inhibitory-?B? in LPS-activated macrophages. Furthermore, we observed that they markedly inhibited the LPS-induced phosphorylations of p38 mitogen-activated protein kinases and extracellular signal-regulated kinases (ERK) at 20??M. These data demonstrate that the sulfur compounds from garlic, (Z, E)-ajoene and their sulfonyl analogs, can suppress the LPS-induced production of NO/PGE(2) and the expression of iNOS/COX-2 genes by inhibiting the NF-?B activation and the phosphorylations of p38 and ERK. Taken together, these data show that Z- and E-ajoene and their sulfonyl analogs from garlic might have anti-inflammatory therapeutic potential. PMID:23057778

Lee, Da Yeon; Li, Hua; Lim, Hyo Jin; Lee, Hwa Jin; Jeon, Raok; Ryu, Jae-Ha

2012-11-01

45

Method for removing sulfur compounds from C/sub 6/ and lower alkanes  

SciTech Connect

A process is described for recovering a low sulfur content hydrocarbon fraction having a boiling point of n-hexane or less from a hydrocarbon stream containing hydrocarbons boiling at or below the boiling point of hexane and organic sulfur compounds comprising monosulfides boiling at or below the boiling point of n-hexane. It consists of contacting the hydrocarbon stream with a dilute aqueous solution of sodium hypochlorite for a time sufficient to convert a selected amount of monosulfide compounds present to compounds having boiling points above the boiling point of n-hexane, separating an aqueous phase and a hydrocarbon phase and fractionally distilling the hydrocarbon phase to recover a hydrocarbon fraction having a boiling point of n-hexane or less, and having a reduced amount of the organic sulfur compounds.

Keyworth, D.A.

1989-03-28

46

Use of reduced sulfur compounds by Beggiatoa sp.  

PubMed Central

A strain of Beggiatoa cf. leptomitiformis (OH-75-B, clone 2a) was isolated which is unique among reported strains in its ability to deposit internal sulfur granules from thiosulfate. It also deposited these characteristic granules (as all BEggiatoa species do) from sulfide. In cultures where growth was limited by exhaustion of organic substrates, these granules generally comprised about 20% of the total cell weight. With medium containing acetate and thiosulfate, no measurable utilization of thiosulfate or deposition of elemental sulfur (S0) took place until after the exponential growth phase. Neither sulfide nor thiosulfate added an increment to heterotrophic growth yield except for the weight of the deposited S0. The deposition of S0 from thiosulfate was probably a disproportionation in which S0 and sulfate were produced in a 1:1 ratio. Some of the S0 was further oxidized to sulfate. No autotrophic or mixotrophic growth was demonstrated for this strain. When inoculated in small, well-dispersed quantities into yeast extract medium, this strain grew only after long lags. Addition of the enzyme catalase eliminated initial lags and increased growth rates slightly. In contrast, catalase had no influence on growth rate when added to mineral medium containing acetate. In yeast extract medium, the inhibition of growth rate was presumably because of peroxides. Addition of thiosulfate was almost as effective as catalase in eliminating this inhibition. The S0 granules which, in this case, were deposited during the exponential growth phase, appeared to be partly responsible for this relief. This strain of Beggiatoa sp. remained active for at least 5 days under strictly anaerobic conditions, and under those conditions, it increased its dry weight by about 2.5-fold. Anaerobic "growth" and maintenance required the presence of an energy source, such as acetate. When cells containing much internal S0 were transferred to an organic anaerobic medium, a substantial portion of the internal S0 was eventually converted to sulfide. PMID:7240091

Nelson, D C; Castenholz, R W

1981-01-01

47

Air/water oxidative desulfurization of coal and sulfur-containing compounds  

NASA Astrophysics Data System (ADS)

Air/water Oxydesulfurization has been demonstrated in autoclave experiments at the Pittsburgh Energy Technology Center for various coals representative of the major U. S. coal basins. The applicability at present of this treatment for producing an environmentally acceptable coal has been restricted by recently proposed SO2 emission standards for utility boilers. The product would, however, be attractive to the many smaller industrial coal users who cannot afford to operate and maintain flue gas desulfurization systems. It is also possible that the utility industry could realize a benefit by using chemically cleaned coal with partial flue gas scrubbing. The higher cost of the cleaned coal would be offset by the reduction in capital and operating costs resulting from decreased FGD requirements. The susceptibility of sulfur in coal to oxidative removal varies with the nature of the sulfur-containing species. The inorganic sulfur compounds, primarily pyrite, marcasite, and iron sulfate, are more amenable to treatment than the organically bound sulfur which exhibits varying degrees of resistance depending on its chemical environment. Air/water Oxydesulfurization consistently removes in excess of 90 percent of the pyritic sulfur; the extent and efficiency of organic sulfur removal however, depends on the type of coal and severity of treatment used. In general, the organic sulfur of the higher rank coals exhibits more resistance to treatment than that of the lower rank coals; however, the accompanying heating value is greater for the latter. Similar treatment of sulfur-containing model compounds further illustrates the relative susceptibilities of different chemical species to oxidation. Application of these data to the understanding of the complex chemistry involved in the treatment of coal is a preliminary step toward improving the efficiency of Oxydesulfurization.

Warzinski, R. P.; Freidman, S.; LaCount, R. B.

1981-02-01

48

Sulfur/lithium-insertion compound composite cathodes for Li-S batteries  

NASA Astrophysics Data System (ADS)

A part of carbon additives in sulfur cathodes is replaced by lithium-insertion compounds as they can contribute extra capacity and increase the overall energy density. Accordingly, VO2(B) and TiS2 were incorporated into sulfur cathodes as they can work within the same voltage window as that of sulfur. However, VO2(B) was found to be incompatible with the glyme-based electrolytes that are usually used in Li-S cells, but TiS2 performs well while coupled with sulfur. The S/C/TiS2 composite cathode delivers 252 mAh g-1 more than that of pristine sulfur cathode (1334 mAh g-1 vs. 1082 mAh g-1). The increased capacity is not only due to the contribution by TiS2 itself but also due to a better active-material dispersion and utilization. Serving as active reaction sites during cycling, TiS2 suppresses agglomeration of sulfur and facilitates better ionic/electronic transport within the cathode structure. This composite cathode design provides another direction for Li-S batteries to improve the overall energy density.

Su, Yu-Sheng; Manthiram, Arumugam

2014-12-01

49

Sulfuric acid-sulfur heat storage cycle  

DOEpatents

A method of storing heat is provided utilizing a chemical cycle which interconverts sulfuric acid and sulfur. The method can be used to levelize the energy obtained from intermittent heat sources, such as solar collectors. Dilute sulfuric acid is concentrated by evaporation of water, and the concentrated sulfuric acid is boiled and decomposed using intense heat from the heat source, forming sulfur dioxide and oxygen. The sulfur dioxide is reacted with water in a disproportionation reaction yielding dilute sulfuric acid, which is recycled, and elemental sulfur. The sulfur has substantial potential chemical energy and represents the storage of a significant portion of the energy obtained from the heat source. The sulfur is burned whenever required to release the stored energy. A particularly advantageous use of the heat storage method is in conjunction with a solar-powered facility which uses the Bunsen reaction in a water-splitting process. The energy storage method is used to levelize the availability of solar energy while some of the sulfur dioxide produced in the heat storage reactions is converted to sulfuric acid in the Bunsen reaction.

Norman, John H. (LaJolla, CA)

1983-12-20

50

Uptake of Small Organic Compounds by Sulfuric Acid Aerosols: Dissolution and Reaction  

NASA Technical Reports Server (NTRS)

To assess the role of oxygenated volatile organic compounds in the upper troposphere and lower stratosphere, the interactions of a series of small organic compounds with low-temperature aqueous sulfuric acid will be evaluated. The total amount of organic material which may be taken up from the gas phase by dissolution, surface layer formation, and reaction during the particle lifetime will be quantified. Our current results for acetaldehyde uptake on 40 - 80 wt% sulfuric acid solutions will be compared to those of methanol, formaldehyde, and acetone to investigate the relationships between chemical functionality and heterogeneous activity. Where possible, equilibrium uptake will be ascribed to component pathways (hydration, protonation, etc.) to facilitate evaluation of other species not yet studied in low temperature aqueous sulfuric acid.

Iraci, L. T.; Michelsen, R. R.; Ashbourn, S. F. M.; Staton, S. J. R.

2003-01-01

51

Detecting endocrine disrupting compounds in water using sulfur-oxidizing bacteria.  

PubMed

For the rapid and reliable detection of endocrine disrupting compounds in water, a novel toxicity detection methodology based on sulfur-oxidizing bacteria (SOB) has been developed. The methodology exploits the ability of SOB to oxidize elemental sulfur to sulfuric acid in the presence of oxygen. The reaction results in an increase in electrical conductivity (EC) and a decrease in pH. When endocrine disrupting compounds were added to the system, the effluent EC decreased and the pH increased due to the inhibition of the SOB. We found that the system can detect these chemicals in the 50-200 ppb range, which is lower than many whole-cell biosensors to date. The SOB biosensor can detect toxicity on the order of min to h which can serve as an early warning so as to not pollute the environment and affect public health. PMID:20580056

Van Ginkel, Steven W; Hassan, Sedky H A; Oh, Sang-Eun

2010-09-01

52

Gas chromatography combined with mass spectrometry for the identification of organic sulfur compounds in shellfish and fish  

SciTech Connect

The authors determined that the organic sulfur compounds usually contained in crude oil can be used as a marker of oil pollution in shellfish and fish. Short-necked clams and eels were maintained in a controlled laboratory environment in water with suspension of crude oil. Mass spectra and mass chromatograms of short-necked clam extract showed the presence of organic sulfur compounds. Capillary column gas chromatography-mass chromatograms of crude oil and extract from the soft body of a short-necked clam showed the presence of organic sulfur compounds. Besides sulfur components, various other compounds were contained in crude oil and short-necked clam. Mass chromatograms of crude oil and the extract from eel flesh showed the presence of alkyl benzothiophene, dibenzothiophene, naphthalene, and alkyl naphthalene. Data indicated that the organic sulfur compounds and polyaromatic compounds could serve as markers of oil pollution in shellfish and fish.

Ogata, M.; Miyake, Y.

1980-11-01

53

Sulfur compounds in therapy: Radiation-protective agents, amphetamines, and mucopolysaccharide sulfation  

SciTech Connect

Sulfur-containing compounds have been used in the search for whole-body radiation-protective compounds, in the design of amphetamine derivatives that retain appetite-suppressive effects but lack most behavioral effects characteristic of amphetamines, and in the search for the cause of kidney stone formation in recurrently stoneforming patients. Organic synthetic procedures were used to prepare radiation-protective compounds having a variety of sulfur-containing functional groups, and to prepare amphetamine derivatives having electron-attracting sulfur functions. In the case of the kidney stone causation research, isolation of urinary mucopolysaccharides (MPS) from recurrently stoneforming patients was carried out and the extent of sulfation of the MPS was determined by electrophoresis. Whole-body radiation-protective agents with a high degree of protection against lethal doses of gamma-radiation in mice were found in a series of quinolinium and pyridinium bis(methylthio) and methylthio amino derivatives. Mechanism studies showed that the copper complexes of these agents mimicked the beneficial action of superoxide dismutase. Electron-attracting sulfur-containing functions on amphetamine nitrogen, as well as 4'-amino nitrogen provided amphetamine derivatives with good appetite-suppressant effects and few or no adverse behavioral effects. Higher than normal levels of sulfation of the urinary MPS of stone formers suggested a cause for recurrent kidney stone formation. A sulfation inhibitor was found to prevent recurrence of stone formation and inhibit growth of existing stones. The inclusion of various sulfur-containing functions in organic molecules yielded compounds having whole-body radiation protection from lethal doses of gamma-radiation in animals. The presence of electron-attracting sulfur functions in amphetamine gave derivatives that retained appetite-suppressant effects and eliminated most adverse behavioral effects.

Foye, W.O. (Massachusetts College of Pharmacy and Allied Health Sciences, Boston (United States))

1992-09-01

54

Sulfur-containing amino acid methionine as the precursor of volatile organic sulfur compounds in algea-induced black bloom.  

PubMed

After the application of methionine, a progressive and significant increase occurred in five volatile organic sulfur compounds (VOSCs): methanethiol (MeSH), dimethyl sulfide (DMS), dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS) and dimethyl tetrasulfide (DMTeS). Even in the untreated control without a methionine addition, methionine and its catabolites (VOSCs, mainly DMDS) were found in considerable amounts that were high enough to account for the water's offensive odor. However, blackening only occurred in two methionine-amended treatments. The VOSCs production was observed to precede black color development, and the reaching of a peak value for total VOSCs was often followed by water blackening. The presence of glucose stimulated the degradation of methionine while postponing the occurrence of the black color and inhibiting the production of VOSCs. In addition, DMDS was found to be the most abundant species produced after the addition of methionine alone, and DMTeS appeared to be the most important compound produced after the addition of methionine+glucose. These results suggest that methionine acted as an important precursor of the VOSCs in lakes suffering from algea-induced black bloom. The existence of glucose may change the transformation pathway of methionine into VOSCs to form larger molecular weight compounds, such as DMTS and DMTeS. PMID:23586297

Lu, Xin; Fan, Chengxin; He, Wei; Deng, Jiancai; Yin, Hongbin

2013-01-01

55

Sulfur 1s near-edge x-ray absorption fine structure (NEXAFS) of thiol and thioether compounds  

SciTech Connect

The speciation and quantification of sulfur species based on sulfur K-edge x-ray absorption spectroscopy is of wide interest, particularly for biological and petroleum science. These tasks require a firm understanding of the sulfur 1s near-edge x-ray absorption fine structure (NEXAFS) spectra of relevant species. To this end, we have examined the gas phase sulfur 1s NEXAFS spectra of a group of simple thiol and thioether compounds. These high-resolution gas phase spectra are free of solid-state broadening, charging, and saturation effects common in the NEXAFS spectra of solids. These experimental data have been further analyzed with the aid of improved virtual orbital Hartree-Fock ab initio calculations. The experimental sulfur 1s NEXAFS spectra show fine features predicted by calculation, and the combination of experiment and calculation has been used to improve assignment of spectroscopic features relevant for the speciation and quantification of the sulfur compounds.

Beyhan, Shirin; Urquhart, Stephen G. [Department of Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5C9 (Canada); Hu Yongfeng [Canadian Light Source, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5C6 (Canada)

2011-06-28

56

Extraction of odorizing sulfur compounds from natural gas and reodorization therewith  

Microsoft Academic Search

Linde AG's new approach permits natural gas odorants to be removed from natural gas before it is liquefied by peakshaving plants and to be saved for reinjection when the natural gas is vaporized. The odorants, mainly organic sulfur compounds, are removed by scrubbing natural gas prior to natural gas liquefaction and then freed of other impurities such as COâ, HâO,

A. Kruis; H. Karwat

1975-01-01

57

Volatile Organic Sulfur Compounds of Environmental Interest: Dimethyl Sulfide and Methanethiol  

ERIC Educational Resources Information Center

Volatile organic sulfur compounds (VOSCs) have been assigned environmental roles in global warming, acid precipitation, and cloud formation where two important members dimethyl sulfide (CH3)2 S, DMS, and methanethiol, CH3SH, MT, of VOSC group are involved.

Chasteen, Thomas G.; Bentley, Ronald

2004-01-01

58

INFLUENCE OF DIETARY METHIONINE SOURCE ON VOLATILE SULFUR COMPOUNDS IN BROILER EXCRETA  

Technology Transfer Automated Retrieval System (TEKTRAN)

To evaluate the impact of methionine source on volatile sulfur compounds in broiler excreta a trial was conducted using straight run broiler chicks raised in battery cages. Chicks were randomly distributed into 3 replications of 5 treatment groups with 16 birds per pen. The treatment groups were d...

59

Development of a pretreatment system for the analysis of atmospheric reduced sulfur compounds.  

PubMed

A new pretreatment system was used to evaluate a technology to analyze reduced sulfur compounds (RSCs). To conduct this research, a self-developed custom dryer (Desolvator) and a thermal desorber system (TDS) were installed in the front of GC/PFPD. The syringe pump inside the TDS was devised in such a way that it can be desorbed in a relatively low desorption temperature and low vacuum (730 Pa). When comparing water removal efficiency of the Desolvator and frequently used Nafion dryer, the removal efficiency of the Desolvator stood between 94.6 and 96.1%, considerably higher and more stable than the Nafion dryer (81.3-94.5%). Moreover, analyses were made under various conditions in order to minimize the loss of samples when analyzing sulfur compounds using the TDS, and it was determined that adsorption temperatures less than -25 °C and a flow rate of 50 mL/min were appropriate for the efficient analysis of these sulfur compounds. Moreover, the desorption flow rate and the degree of a vacuum were found to be significant variables for the RSCs desorption. Besides, it was observed that a peculiar peak was formed by thermal decomposition when some sulfur compounds were rapidly desorbed at high desorption temperatures. PMID:24127877

Son, Youn-Suk; Lee, Gangwoong; Kim, Jo-Chun; Han, Jin-Seok

2013-11-01

60

Sulfuric Acid in the Venus Clouds  

NASA Technical Reports Server (NTRS)

The visible and ultraviolet transmission features of a thin layer of elemental bromine and hydrobromic acid dissolved in sulfuric acid somewhat resemble the Venus spectrum, up to 14 microns. The chemical process postulated for forming sulfuric acid involves the oxidation of sulfur and its compounds to sulfuric acid through the agency of elemental bromine, produced by the photolytic decomposition of hydrogen bromide.

Sill, G. T.

1972-01-01

61

Sulfur and Hydrogen Isotope Anomalies in Organic Compounds from the Murchison Meteorite  

NASA Technical Reports Server (NTRS)

Isotopic measurements have been made on organic sulfur and phosphorus compounds recently discovered in the Murchison meteorite. Carbon, hydrogen and sulfur measurements were performed on individual members of the organic sulfur compounds, alkyl sulfonates; and carbon and hydrogen measurements were made on bulk alkyl phosphonates. Cooper and Chang reported the first carbon isotopic measurements of Murchison organic sulfonates, providing insight into the potential synthetic mechanisms of these and, possibly, other organic species. Hydrogen isotopic measurements of the sulforiates now reveal deuterium excesses ranging from +660 to +2730 %. The deuterium enrichments indicate formation of the hydrocarbon portion of these compounds in a low temperature astrophysical environment consistent with that of dense molecular clouds. Measurements of the sulfur isotopes provide further constraints on the origin and mechanism of formation of these organic molecules. Recently, there has been growing documentation of sulfur isotopic anomalies in meteoritic material. Thiemens and Jackson have shown that some bulk ureilites possess excess S-33 and Thiemens et al. have reported excess S-33 in an oldhamite separate from the Norton County meteorite. Rees and Thode reported a large S-33 excess in an Allende acid residue, however, attempts to verify this measurements have been unsuccessful, possibly due to the heterogeneous nature of the carrier phase. With the recognition that sulfur isotopes may reflect chemistry in the protosolar nebula or the precursor molecular cloud, identification of potential carriers is of considerable interest. In the present study, the stable isotopes of sulfur were measured in methane sulfonic acid extracted from the Murchison meteorite. The isotopic composition was found to be: (delta)S-33 = 2.48 %, (delta)S-34 = 2.49 % and (delta)S-36 = 6.76 %. Based upon analysis of more than 60 meteoritic and numerous terrestrial samples, the mass fractionation lines are defined by Delta-33 = (delta)S-33 -0.50(delta)S-34 and Delta-36 = (delta)s-36 - 1.97 (delta)S-34. From these relationships Delta-33 = 1.24 % and Delta-36 = 0.89 % are observed. These anomalies, particularly the Delta-33, lie well outside the range of analytical uncertainty. They are the largest observed in any meteoritic component and the first found in an organosulfur compound. As discussed by Thiemens and Jackson, due to it's position on the periodic chart, sulfur undergoes chemically induced mass independent isotopic fractionations as does oxygen. Experiments by Mauersberger et. al. show that in such processes, the magnitude of fractionation for the different isotopically substituted species varies with mass and angular momentum; thus, anomalies are expected for both S-33 and S-36, but not necessarily of the same magnitude. Laboratory experiments have also confirmed that chemically produced, mass independent fractionations are mediated by molecular symmetry factors. A chemical source of fractionation requires that the sulfur isotopic anomaly was established in the gas phase, probably in reactions involving symmetric CS2. The discovery of an anomalous sulfur isotopic composition in a specific molecule containing excess deuterium is an important advance in the understanding of the cosmochemistry of sulfur. This evidence suggests that methanesulfonic acid was synthesized by interstellar processes. Further measurements and details of possible synthesis and fractionation mechanisms will be presented.

Cooper, G. W.; Thiemens, M. H.; Jackson, T.; Chang, Sherwood

1996-01-01

62

Comparison of microbial sulfuric acid production in sewage sludge from added sulfur and thiosulfate  

Microsoft Academic Search

Microbial leaching is one of the most attractive methods of removing toxic metals from sewage sludge. Sulfuric acid produced by indigenous microflora by the oxidation of elemental sulfur and sulfur compounds solubilizes toxic metals. The oxidation of sulfur compounds can be achieved by the direct oxidation to sulfates or by indirect oxidation, through the production and accumulation of soluble intermediate

R. D. Tyagi; J. F. Blais; L. Deschenes; P. Lafrance; J. P. Villeneuve

1994-01-01

63

EVALUATION OF TECHNIQUES FOR MEASURING BIOGENIC AIRBORNE SULFUR COMPOUNDS, CEDAR ISLAND FIELD STUDY, 1977  

EPA Science Inventory

Sulfur in both gaseous and particulate form has been measured near biogenic sources using new measurement techniques. The preconcentration of gaseous sulfur on gold-coated glass beads followed by desorption into a flame photometric detection for sulfur is shown to have a detectio...

64

ATMOSPHERIC CHEMISTRY OF SELECTED SULFUR-CONTAINING COMPOUNDS. OUTDOOR SMOG CHAMBER STUDY. PHASE 2  

EPA Science Inventory

The photochemical behavior of mixtures of selected sulfur containing species, hydrocarbons, and nitrogen oxides was examined in outdoor smog chambers. Sulfur dioxide, H2S, CH3SH, COS, and thiophene are the sulfur species tested. A surrogate ambient hydrocarbon mixture comprised o...

65

Magmatic sulfur compounds and sulfur diffusion in albite melt at 1 GPa and 1300-1500 8C  

Microsoft Academic Search

The speciation and diffusion of sulfur in nominally dry albite melt at 1300-1500 8C has been investigated by analyzing glasses formed in piston-cylinder runs using electron microprobe, micro-Raman, infrared-, UV-, and visible-light-spectroscopy, and other tech- niques. The sulfate ion is very stable in the albite melt even at low and is the dominant f o2 species in all glasses. In

K. TOBIAS WINTHER; E. BRUCE WATSON; GERALD M. KORENOWSKI

66

Thermothrix thiopara: Growth and Metabolism of a Newly Isolated Thermophile Capable of Oxidizing Sulfur and Sulfur Compounds  

PubMed Central

Thermothrix thiopara is isolated from hot sulfur springs. It occurs in situ at a temperature of 72°C, a pH of 7.0, and an HS- concentration of 17.4 ?mol/liter (0.8 ppm). The organism was capable of autotrophic growth. Sulfite, sulfur, and polythionates were formed and subsequently degraded to sulfate during growth with thiosulfate as the sole energy source. Thiosulfate was oxidized by the polythionate pathway, and the stoichiometry of growth on thiosulfate was determined. The organism was also capable of heterotrophic growth in amino acids and simple sugars. A source of reduced sulfur (methionine, glutathione) was required for heterotrophic growth. Growth occurred aerobically or anaerobically with nitrate as a terminal oxidant. Both nitrous oxide and dinitrogen were produced. At 73°C the maximum autotrophic growth rate in batch culture using thiosulfate was 0.56 generation per h. Under the same conditions in continuous culture, washout occurred at a dilution rate of 0.3 to 0.4 per h, corresponding to a cellular growth rate of 0.43 to 0.58 generation per h. This was nearly three times the growth rate for Thiobacillus denitrificans. T. thiopara is gram negative. It was also found to be both lysozyme and penicillin susceptible. As a result, this organism cannot be considered an archaebacterium. PMID:16345601

Brannan, Daniel K.; Caldwell, Douglas E.

1980-01-01

67

Emission of volatile organic sulfur compounds (VOSCs) during aerobic decomposition of food wastes  

NASA Astrophysics Data System (ADS)

Food wastes collected from typical urban residential communities were investigated for the emission of volatile organic sulfur compounds (VOSCs) during laboratory-controlled aerobic decomposition in an incubator for a period of 41 days. Emission of VOSCs from the food wastes totaled 409.9 mg kg -1 (dry weight), and dimethyl disulfide (DMDS), dimethyl sulfide (DMS), methyl 2-propenyl disulfide, carbonyl sulfide and methyl 1-propenyl sulfide were the five most abundant VOSCs, with shares of 75.5%, 13.5%, 4.8%, 2.2% and 1.3% in total 15 VOSCs released, respectively. The emission fluxes of major VOSCs were very low at the beginning (day 0). They peaked at days 2-4 and then decreased sharply until they leveled off after 10 days of incubation. For most VOSCs, over 95% of their emission occurred in the first 10 days. The time series of VOSC emission fluxes, as well as their significant correlation with internal food waste temperature ( p < 0.05) during incubation, suggested that production of VOSC species was induced mainly by microbial activities during the aerobic decomposition instead of as inherited. Released VOSCs accounted for 5.3% of sulfur content in the food wastes, implying that during aerobic decomposition considerable portion of sulfur in food wastes would be released into the atmosphere as VOSCs, primarily as DMDS, which is very short-lived in the atmosphere and thus usually less considered in the sources and sinks of reduced sulfur gases.

Wu, Ting; Wang, Xinming; Li, Dejun; Yi, Zhigang

2010-12-01

68

Thermodynamics of Aqueous Organic Sulfur Compounds: A Key to the Organic Geochemistry of Hydrothermal Systems?  

NASA Technical Reports Server (NTRS)

Hydrothermal environments are locations of varied geochemistry due to the disequilibrium between vent fluids and seawater. The disequilibrium geochemistry has been hypothesized to include reactions to synthesize organic compounds. Observations of the organic geochemistry of hydrothermal vent sites has received little attention. Experimental simulations of these environments, however, indicate that organic compounds may have difficulty forming in a purely aqueous environment. On the other hand, thiols. thioesters and disulfides have been implicated as reaction intermediates between CO or CO2 in experiments of carbon reduction in hydrothermal environments as well as in a variety of biological processes and other abiotic reactions (Wachtershauser, 1990, OLEB 20, 173; Heinen and Lauwers, 1996, OLEB 26, 13 1, Huber and Wachtershauser, 1997, Science 276, 245; Russell et al., 1998, in Thermophiles: The keys to molecular evolution and the origin of life?). The reduction of CO2 to thiols, for example, is observed using the FeS-H2S/FeS2 couple to provide the reducing power (see Schoonen et al., 1999, OLEB 29, 5). In addition, the enzyme involved in final stage of methanogenesis, coenzyme-M, is itself a thiol. Thus, organic sulfur compounds may hold the key to the organic chemistry leading to the origin of life at high temperatures. Understanding the biochemical processes of microorganisms that can live to temperatures at least as high as 113 C (Blochl et al., 1996, Extremophiles 1, 14) requires knowledge of the properties of the chemical reactions involved. In order to assess the role of aqueous organic sulfur compounds in hydrothermal organic geochemistry, we have been attempting to determine their thermodynamic properties. We have culled the literature to obtain the properties of organic sulfur compounds. We are able to calculate a number of essential properties, such as free energies of formation, from solubility data available in the literature together with standard properties of organic sulfur gases. However, a number of the properties for aqueous organic sulfur compounds have not been experimentally determined. Furthermore, most of thermodynamic data that are available are for 25 C and 1 bar. In order to determine reaction properties to temperatures and pressures appropriate to the hydrothermal conditions in which thermophilic organisms actually live, we use equations of state developed by Helgeson and co-workers (Helgeson et al., 1981, AJS 281, 1249). A key piece of information needed to go up in temperature is the partial molal heat capacity, which is one of the properties for which experimental data are unavailable for nearly all organic sulfur compounds. We have used correlation methods to determine the partial molal heat capacities and volumes of many organic solutes. These estimates allow us to asses the role of organic sulfur compounds during the reduction of carbon in hydrothermal settings. We will present these data, along with examples of the thermodynamic properties of reactions involving aqueous organic sulfur compounds.

Schulte, Mitchell; Rogers, Karyn L.; DeVincenzi, Donald L. (Technical Monitor)

2000-01-01

69

Molecular Structure of sulfur  

NSDL National Science Digital Library

The discoverer of sulfur remains anonymous because of lack of records. However, one can trace back to the discovery of R.W. Wood when he used ultra-violet rays to find a sulfur deposit near the crater of Aristarchus on the moon. Sulfur is also found in meteorites. In the United States, Sulfur can be found along the Gulf Coast in wells sunk along salt domes. It is brought to the surface using the Frasch Process in which heated water is forced into the wells and melts the surface. Sulfur may also be found in volcanos or hot springs. Other uses of Sulfur include making phosphatic fertilizers, matches, and medicine. The mineral is a good insulator and takes part in bleaching dried fruit. Sulfur is a minor constitute of body fluids, fats, and skeletal minerals. It can be said that Sulfur is essential to life.

2002-08-26

70

Sulfuric acid poisoning  

MedlinePLUS

Sulfuric acid is a very strong chemical that is corrosive. Corrosive means it can cause severe burns and ... or mucous membranes. This article discusses poisoning from sulfuric acid. This is for information only and not for ...

71

Regulation of a Novel Acidithiobacillus caldus Gene Cluster Involved in Metabolism of Reduced Inorganic Sulfur Compounds  

Microsoft Academic Search

Acidithiobacillus caldus has been proposed to play a role in the oxidation of reduced inorganic sulfur compounds (RISCs) produced in industrial biomining of sulfidic minerals. Here, we describe the regu- lation of a new cluster containing the gene encoding tetrathionate hydrolase (tetH), a key enzyme in the RISC metabolism of this bacterium. The cluster contains five cotranscribed genes, ISac1, rsrR,

Olena I. Rzhepishevska; Jorge Valdes; Liucija Marcinkeviciene; Camelia Algora Gallardo; Rolandas Meskys; Violaine Bonnefoy; David S. Holmes; Mark Dopson

2007-01-01

72

Involvement of a BranchedChain Aminotransferase in Production of Volatile Sulfur Compounds in Yarrowia lipolytica  

Microsoft Academic Search

The enzymatic degradation of L-methionine and the subsequent formation of volatile sulfur compounds (VSCs) are essential for the development of the typical flavor in cheese. In the yeast Yarrowia lipolytica, the degradation of L-methionine was accompanied by the formation of the transamination product 4-methylthio- 2-oxobutyric acid. A branched-chain aminotransferase gene (YlBCA1 )o fY. lipolytica was amplified, and the L-methionine-degrading activity

Daniela Cernat Bondar; Jean-Marie Beckerich; Pascal Bonnarme

2005-01-01

73

Volatile Reduced Sulfur Compounds: Detection and Quantification in a Stratified Freshwater Lake  

NASA Astrophysics Data System (ADS)

It is now generally recognized that volatile reduced sulfur compounds (VRSCs), including hydrogen sulfide (H2S), carbon disulfide (CS2), methyl sulfide (MS), dimethyl sulfide (DMS), and dimethyl disulfide (DMDS) are significant constituents for atmospheric sulfur. Therefore, they play an important role in large-scale sulfur cycling. To date these compounds have been thoroughly investigated and quantified in open oceans and coastal marine environments. Additionally the export of VRSCs from marine surface waters to the atmosphere may implicate these compounds in global climate regulation. While current literature focuses on the biogeochemistry of VRSCs in marine systems, a comprehensive understanding of the global biogeochemistry of VRSCs necessitates more rigorous studies in freshwater environments. We will present concentration profiles of VRSCs in Linsley Pond, a stratified freshwater lake in Branford, CT. We developed an extremely sensitive methods for VSRCS measurements that relies on a purge-trap system coupled to gas chromatography with a pulsed flame photometric detector (PFPD). Using this method, we sampled Linsley Pond weekly to bimonthly during the initial stages of stratification in the spring and during mixing in the fall. Influence of the oxidation/reduction potential in the aquatic environment on the distribution of VRSCs over the complete water column and possible sources of VRSCs were also investigated.

Mylon, S. E.; Hu, H.; Benoit, G.

2003-12-01

74

Catalytic oxidation of gaseous reduced sulfur compounds using coal fly ash.  

PubMed

Activated carbon has been shown to oxidize reduced sulfur compounds, but in many cases it is too costly for large-scale environmental remediation applications. Alternatively, we theorized that coal fly ash, given its high metal content and the presence of carbon could act as an inexpensive catalytic oxidizer of reduced sulfur compounds for "odor" removal. Initial results indicate that coal fly ash can catalyze the oxidization of H(2)S and ethanethiol, but not dimethyl sulfide (DMS) and dimethyl disulfide (DMDS) at room temperature. In batch reactor systems, initial concentrations of 100-500 ppmv H(2)S or ethanethiol were reduced to 0-2 ppmv within 1-2 and 6-8 min, respectively. This was contrary to control systems without ash in which concentrations remained constant. Diethyl disulfide was formed from ethanethiol substantiating the claim that catalytic oxidation occurred. The presence of water increased the rate of adsorption/reaction of both H(2)S and ethanethiol for the room temperature reactions (23-25 degrees C). Additionally, in a continuous flow packed bed reactor, a gaseous stream containing an inlet H(2)S concentration of 400-500 ppmv was reduced to 200 ppmv at a 4.6s residence time. The removal efficiency remained at 50% for approximately 4.6h or 3500 reactor volumes. These results demonstrate the potential of using coal fly ash in reactors for removal of H(2)S and other reduced sulfur compounds. PMID:12409240

Kastner, James R; Das, K C; Melear, Nathan D

2002-11-11

75

Sulfuric acid on Europa and the radiolytic sulfur cycle  

NASA Technical Reports Server (NTRS)

A comparison of laboratory spectra with Galileo data indicates that hydrated sulfuric acid is present and is a major component of Europa's surface. In addition, this moon's visually dark surface material, which spatially correlates with the sulfuric acid concentration, is identified as radiolytically altered sulfur polymers. Radiolysis of the surface by magnetospheric plasma bombardment continuously cycles sulfur between three forms: sulfuric acid, sulfur dioxide, and sulfur polymers, with sulfuric acid being about 50 times as abundant as the other forms. Enhanced sulfuric acid concentrations are found in Europa's geologically young terrains, suggesting that low-temperature, liquid sulfuric acid may influence geological processes.

Carlson, R. W.; Johnson, R. E.; Anderson, M. S.

1999-01-01

76

Sulfur tolerant anode materials  

SciTech Connect

The goal of this program is the development of a molten carbonate fuel cell (MCFC) anode which is more tolerant of sulfur contaminants in the fuel than the current state-of-the-art nickel-based anode structures. This program addresses two different but related aspects of the sulfur contamination problem. The primary aspect is concerned with the development of a sulfur tolerant electrocatalyst for the fuel oxidation reaction. A secondary issue is the development of a sulfur tolerant water-gas-shift reaction catalyst and an investigation of potential steam reforming catalysts which also have some sulfur tolerant capabilities. These two aspects are being addressed as two separate tasks.

Not Available

1987-02-01

77

Biochemistry of sulfur  

SciTech Connect

This book presents information on the following topics: the chemistry of sulfur; the oxidation states of sulfur; the reduction of sulfate and the oxidation of sulfide; the sulfur cycle; oxidation of inorganic sulfide; the metabolism and functions of methionine; taurine and the oxidative metabolism of cysteine; thiols, disulfides, and thioesters; thioethers; thiamine; biotin; sulfates; inherited disorders of sulfur metabolism; cystinuria; sulfur and the metabolism of xenobiotics; general aspects of xenobiotic metabolism; glutathione and sulfation of xenobiotics; and metabolic activation as a result of sulfate conjugation.

Huxtable, R.J.; LaFranconi, W.M.

1986-01-01

78

Sulfur tolerant anode materials  

SciTech Connect

The goal of this program is the development of a molten carbonate fuel cell (MCFC) anode which is more tolerant of sulfur contaminants in the fuel than the current state-of-the-art nickel-based anode structures. This program addresses two different but related aspects of the sulfur contamination problem. The primary aspect is concerned with the development of a sulfur tolerant electrocatalyst for the fuel oxidation reaction. A secondary issue is the development of a sulfur tolerant water-gas-shift reaction catalyst and an investigation of potential steam reforming catalysts which also have some sulfur tolerant capabilities. These two aspects are being addressed as two separate tasks.

Not Available

1988-05-01

79

PCDD/Fs' suppression by sulfur-amine/ammonium compounds.  

PubMed

Three distinct -S and -NH2 or NH4(+) containing compounds, including ammonium thiosulfate, aminosulfonic acid and thiourea, were studied as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) inhibitors. All these three -S and -N containing compounds tested show strong suppression of PCDD/Fs formation, especially for thiourea which has not been studied before. With a (S+N)/Cl molar ratio of only 0.47, thiourea could inhibit 97.3% of PCDD/Fs and even 99.8% of I-TEQ. At an unusually high de novo test temperature (650°C), the PCDD/Fs' formation was still very low but also the inhibition capacity of thiourea was weak, with an efficiency of 59% for PCDD/Fs when with a (S+N)/Cl molar ratio of 1.40. The results also revealed that the inhibition capability of the combined -S/-NH2 or -S/NH4(+) suppressant was strongly influenced by both the nature of the functional group of nitrogen and the value of the molar ratio (S+N)/Cl. The amine functional group -NH2 tends to be more efficient than ammonium NH4(+) and within a certain range a higher (S+N)/Cl value leads to a higher inhibition efficiency. Moreover, the emission of gases was continuously monitored: the Gasmet results revealed that SO2, HCN and NH3 were the most important decomposition products of thiourea. Thiourea is non-toxic, environment-friendly and can be sprayed into the post-combustion zone in form of powder or aqueous solution. The cost of thiourea at least can be partially compensated by its high inhibition efficiency. Therefore, the application of thiourea in a full-scale incinerator system is promising and encouraging. PMID:25481352

Fu, Jian-Ying; Li, Xiao-Dong; Chen, Tong; Lin, Xiao-Qing; Buekens, Alfons; Lu, Sheng-Yong; Yan, Jian-Hua; Cen, Ke-Fa

2015-03-01

80

Molecular Structure of Sulfuric Acid  

NSDL National Science Digital Library

H2SO4 was discovered by alchemists and made from heating a compound of iron sulfate. In 1740, sulfuric acid was produced for commercial sale. Sulfuric acid is a very strong acid which is used in car batteries. The acid disassociates in water to give two protons and sulfate. This acid can destroy flesh and cause blindness. It was discovered in the 19th century that adding sulfuric acid to soil produces phosphorus, which is beneficial to plants; hence, sulfuric acid is used as a fertilizer in the form of super phosphate and ammonium sulfate. Sulfuric acid is also used to refine petroleum and process metals, and is found in paints and car batteries.

2002-08-15

81

Electroanalytical Chemistry of Sulfur Compounds For the New Coal Conversion Technologies  

Microsoft Academic Search

Polarographic methods are described “tailor-made” for the speciation and determination of sulfur contaminants in synfuels and coal gasification\\/liquefaction process streams. In samples containing the anions, S x, sulfidic sulfur was quantitated by anodic depolarization of the dropping mercury electrode, while polysulfidic sulfur was determined with the aid of an electroreduction process implicating 2(x-1) electrons. Polythionates were electroreduced to thiosulfate, sulfite,

Joseph Jordan; Jonathan Talbott; Joseph Yakupkovic

1989-01-01

82

Topsoe`s Wet gas Sulfuric Acid (WSA) process: An alternative technology for recovering refinery sulfur  

Microsoft Academic Search

The Topsoe Wet gas Sulfuric Acid (WSA) process is a catalytic process which produces concentrated sulfuric acid from refinery streams containing sulfur compounds such as HâS (Claus plant feed), Claus plant tail gas, SOâ (FCC off-gas, power plants), and spent sulfuric acid (alkylation acid). The WSA process recovers up to 99.97% of the sulfur value in the stream as concentrated

1995-01-01

83

Molecular characterization of nitrogen and sulfur containing compounds in night-time SOA  

NASA Astrophysics Data System (ADS)

The oxidation of volatile organic compounds (VOCs) leads to the formation of low volatile organic compounds that can form secondary organic aerosol (SOA). Studies in the past showed that laboratory generated and ambient SOA are made of polar molecules with O/C ratios generally greater than 0.5. More recent studies have shown that SOA compounds can contain heteroatoms mainly sulfur and nitrogen atoms. Offline chemical analysis with high-resolution mass spectrometers and fragmentation experiments has shown that sulphur containing compounds are mainly organosulfates and nitrogen containing species are aromatic heterocyclic compounds such as imidazole and nitrated aromatic compounds such as nitrophenols. In addition to these, SOA compounds containing both sulfur and nitrogen have been reported from the analysis of ambient organic aerosol, rainwater, fog and cloud samples. Based on the mass spectrometric evidence these compounds are attributed to nitrooxy-organosulfates originating from isoprene and monoterpenes. Although these compounds are ubiquitously detected in the ambient samples, reports about their detection in laboratory generated SOA are scares and their formation mechanisms are not well understood. In the present study, we investigated the formation of sulfur and nitrogen containing SOA species in the oxidation of biogenic VOCs. Photooxidation and night-time oxidation experiments were performed in a smog chamber to produce SOA samples. The laboratory generated SOA samples were analysed with UPLC-IMS-TOFMS (Ultra Performance Liquid Chromatography coupled to Ion Mobility Spectrometry and Time of Flight Mass Spectrometry). The presence of highly acidic sulphate seed particles (pH0) did not promote the formation of compounds with chemical formula of C10H17NO7S- and m/z value of 294.0653, indicating that the formation mechanisms of these compounds unlikely involve the ring opening reactions of epoxides and subsequent sulfation reactions. On the other hand, their formation was significantly enhanced when the night-time oxidation was performed in the presence of both neutral seed particle and gas-phase SO2, suggesting that the presence of gas-phase SO2 is a key for their formation.

Iinuma, Yoshiteru; Mutzel, Anke; Rodigast, Maria; Böge, Olaf; Herrmann, Hartmut

2014-05-01

84

Lunar Sulfur Capture System  

NASA Technical Reports Server (NTRS)

The Lunar Sulfur Capture System (LSCS) protects in situ resource utilization (ISRU) hardware from corrosion, and reduces contaminant levels in water condensed for electrolysis. The LSCS uses a lunar soil sorbent to trap over 98 percent of sulfur gases and about two-thirds of halide gases evolved during hydrogen reduction of lunar soils. LSCS soil sorbent is based on lunar minerals containing iron and calcium compounds that trap sulfur and halide gas contaminants in a fixed-bed reactor held at temperatures between 250 and 400 C, allowing moisture produced during reduction to pass through in vapor phase. Small amounts of Earth-based polishing sorbents consisting of zinc oxide and sodium aluminate are used to reduce contaminant concentrations to one ppm or less. The preferred LSCS configuration employs lunar soil beneficiation to boost concentrations of reactive sorbent minerals. Lunar soils contain sulfur in concentrations of about 0.1 percent, and halogen compounds including chlorine and fluorine in concentrations of about 0.01 percent. These contaminants are released as gases such as H2S, COS, CS2,HCl, and HF during thermal ISRU processing with hydrogen or other reducing gases. Removal of contaminant gases is required during ISRU processing to prevent hardware corrosion, electrolyzer damage, and catalyst poisoning. The use of Earth-supplied, single-use consumables to entirely remove contaminants at the levels existing in lunar soils would make many ISRU processes unattractive due to the large mass of consumables relative to the mass of oxygen produced. The LSCS concept of using a primary sorbent prepared from lunar soil was identified as a method by which the majority of contaminants could be removed from process gas streams, thereby substantially reducing the required mass of Earth-supplied consumables. The LSCS takes advantage of minerals containing iron and calcium compounds that are present in lunar soil to trap sulfur and halide gases in a fixedbed reactor downstream of an in-ISRU process such as hydrogen reduction. The lunar-soil-sorbent trap is held at a temperature significantly lower than the operating temperature of the hydrogen reduction or other ISRU process in order to maximize capture of contaminants, but is held at a high enough temperature to allow moisture to pass through without condensing. The lunar soil benefits from physical beneficiation to remove ultrafine particles (to reduce pressure drop through a fixed bed reactor) and to upgrade concentrations of iron and/or calcium compounds (to improve reactivity with gaseous contaminants).

Berggren, Mark; Zubrin, Robert; Bostwick-White, Emily

2013-01-01

85

Effect of sulfur-containing compounds on anaerobic degradation of cellulose to methane by mixed cultures obtained from sewage sludge.  

PubMed Central

Tests were made to determine the effects of inorganic and organic sulfur sources on the degradation of cellulose to methane in a chemically defined medium with sulfur-poor inoculum prepared from sewage sludge. The results show that a sulfur source of about a 0.85 mM concentration is essential for the degradation of cellulose to CH4. However, the production of CH4 from CO2 and H2 provided in the headspace occurred with 0.1 mM sulfate or sulfide. At a 9 mM concentration, all inorganic sulfur compounds other than sulfate inhibited both cellulose degradation and methane formation, and this inhibition increased in the order thiosulfate less than sulfite less than sulfide less than H2S. It appears that the degradation of cellulose to CH4 in a sulfate-free medium by inoculum maintained in a low-sulfur medium is inhibited because of the lack of availability of sulfur for growth of bacteria and synthesis of cell materials and sulfur-containing cofactors involved in cellulose degradation and methanogenesis. The reduction of methanogenesis by higher levels of sulfate probably occurs as a result of stimulation of reactions converting acetate and H2 to end products other than CH4. PMID:677869

Khan, A W; Trottier, T M

1978-01-01

86

Inhibition of Microbial Growth by Ajoene, a Sulfur-Containing Compound Derived from Garlic  

Microsoft Academic Search

Ajoene, a garlic-derived sulfur-containing compound that prevents platelet aggregation, exhibited broad- spectrum antimicrobial activity. Growth of gram-positive bacteria, such as Bacillus cereus, Bacillus subtilis, Mycobacteriumsmegmatis,andStreptomycesgriseus,wasinhibitedat5 mgofajoeneperml.Staphylococcusaureus andLactobacillus plantarumalso were inhibited below 20 mg of ajoene per ml. For gram-negative bacteria, such asEscherichia coli,Klebsiella pneumoniae, andXanthomonas maltophilia, MICs were between 100 and 160 mg\\/ml. Ajoene also inhibited yeast growth at concentrations

RIE NAGANAWA; NAMI IWATA; KEIKO ISHIKAWA; HIROYUKI FUKUDA; TSUCHIYOSHI FUJINO; ANDATSUSHI SUZUKI

1996-01-01

87

Cycling of volatile organic sulfur compounds in anaerobically digested biosolids and its implications for odors.  

PubMed

The objectives of this research were to elucidate the mechanisms for production and degradation of volatile organic sulfur compounds (VOSCs), key odor causing compounds produced by biosolids. These compounds included methanethiol (MT), dimethyl sulfide (DMS), and dimethyl disulfide (DMDS). A series of experiments were used to probe various pathways hypothesized to produce and degrade these VOSCs. The production of MT was found to mainly occur from degradation of methionine and the methylation of hydrogen sulfide. DMS was formed through the methylation of MT. DMDS was formed by MT oxidation. All three of the VOSCs were readily degraded by methanogens and a cyclic pathway was proposed to describe the production and degradation of VOSCs. The research demonstrated that the main source of VOSCs was the biodegradation of protein within the biosolids and the results provided a framework for understanding the production of odor from anaerobically digested sludges before and after dewatering. PMID:16629264

Higgins, Matthew J; Chen, Yen-Chih; Yarosz, Douglas P; Murthy, Sudhir N; Maas, Nick A; Glindemann, Dietmar; Novak, John T

2006-03-01

88

ADVANCED SULFUR CONTROL CONCEPTS  

SciTech Connect

Conventional sulfur removal in integrated gasification combined cycle (IGCC) power plants involves numerous steps: COS (carbonyl sulfide) hydrolysis, amine scrubbing/regeneration, Claus process, and tail-gas treatment. Advanced sulfur removal in IGCC systems involves typically the use of zinc oxide-based sorbents. The sulfides sorbent is regenerated using dilute air to produce a dilute SO{sub 2} (sulfur dioxide) tail gas. Under previous contracts the highly effective first generation Direct Sulfur Recovery Process (DSRP) for catalytic reduction of this SO{sub 2} tail gas to elemental sulfur was developed. This process is currently undergoing field-testing. In this project, advanced concepts were evaluated to reduce the number of unit operations in sulfur removal and recovery. Substantial effort was directed towards developing sorbents that could be directly regenerated to elemental sulfur in an Advanced Hot Gas Process (AHGP). Development of this process has been described in detail in Appendices A-F. RTI began the development of the Single-step Sulfur Recovery Process (SSRP) to eliminate the use of sorbents and multiple reactors in sulfur removal and recovery. This process showed promising preliminary results and thus further process development of AHGP was abandoned in favor of SSRP. The SSRP is a direct Claus process that consists of injecting SO{sub 2} directly into the quenched coal gas from a coal gasifier, and reacting the H{sub 2}S-SO{sub 2} mixture over a selective catalyst to both remove and recover sulfur in a single step. The process is conducted at gasifier pressure and 125 to 160 C. The proposed commercial embodiment of the SSRP involves a liquid phase of molten sulfur with dispersed catalyst in a slurry bubble-column reactor (SBCR).

Apostolos A. Nikolopoulos; Santosh K. Gangwal; William J. McMichael; Jeffrey W. Portzer

2003-01-01

89

Sulfur isotopic data  

SciTech Connect

Preliminary sulfur isotope data have been determined for samples of the Vermillion Creek coal bed and associated rocks in the Vermillion Creek basin and for samples of evaporites collected from Jurassic and Triassic formations that crop out in the nearby Uinta Mountains. The data are inconclusive, but it is likely that the sulfur in the coal was derived from the evaporites.

Rye, R.O.

1987-01-01

90

Field sampling method for quantifying volatile sulfur compounds from animal feeding operations  

NASA Astrophysics Data System (ADS)

Volatile sulfur compounds (VSCs) are a major class of chemicals associated with odor from animal feeding operations (AFOs). Identifying and quantifying VSCs in air is challenging due to their volatility, reactivity, and low concentrations. In the present study, a canister-based method collected whole air in fused silica-lined (FSL) mini-canister (1.4 L) following passage through a calcium chloride drying tube. Sampled air from the canisters was removed (10-600 mL), dried, pre-concentrated, and cryofocused into a GC system with parallel detectors (mass spectrometer (MS) and pulsed flame photometric detector (PFPD)). The column effluent was split 20:1 between the MS and PFPD. The PFPD equimolar sulfur response enhanced quantitation and the location of sulfur peaks for mass spectral identity and quantitation. Limit of quantitation for the PFPD and MSD was set at the least sensitive VSC (hydrogen sulfide) and determined to be 177 and 28 pg S, respectively, or 0.300 and 0.048 ?g m -3 air, respectively. Storage stability of hydrogen sulfide and methanethiol was problematic in warm humid air (25 °C, 96% relative humidity (RH)) without being dried first, however, stability in canisters dried was still only 65% after 24 h of storage. Storage stability of hydrogen sulfide sampled in the field at a swine facility was over 2 days. The greater stability of field samples compared to laboratory samples was due to the lower temperature and RH of field samples compared to laboratory generated samples. Hydrogen sulfide was the dominant odorous VSCs detected at all swine facilities with methanethiol and dimethyl sulfide detected notably above their odor threshold values. The main odorous VSC detected in aged poultry litter was dimethyl trisulfide. Other VSCs above odor threshold values for poultry facilities were methanethiol and dimethyl sulfide.

Trabue, Steven; Scoggin, Kenwood; Mitloehner, Frank; Li, Hong; Burns, Robert; Xin, Hongwei

91

Elemental sulfur recovery process  

DOEpatents

An improved catalytic reduction process for the direct recovery of elemental sulfur from various SO.sub.2 -containing industrial gas streams. The catalytic process provides combined high activity and selectivity for the reduction of SO.sub.2 to elemental sulfur product with carbon monoxide or other reducing gases. The reaction of sulfur dioxide and reducing gas takes place over certain catalyst formulations based on cerium oxide. The process is a single-stage, catalytic sulfur recovery process in conjunction with regenerators, such as those used in dry, regenerative flue gas desulfurization or other processes, involving direct reduction of the SO.sub.2 in the regenerator off gas stream to elemental sulfur in the presence of a catalyst.

Flytzani-Stephanopoulos, Maria (Winchester, MA); Hu, Zhicheng (Somerville, MA)

1993-01-01

92

Electroanalytical chemistry of sulfur compounds for the new coal conversion technologies  

SciTech Connect

Polarographic methods are described tailor-made for the speciation and determination of sulfur contaminants in synfuels and coal gasification/liquefaction process streams. In samples containing the anions, S{sub x}{sup 2{minus}}, sulfidic sulfur was quantitated by anodic depolarization of the dropping mercury electrode, while polysulfidic sulfur was determined with the aid of an electroreduction process implicating 2(x-1) electrons. Polythionates were electroreduced to thiosulfate, sulfite, sulfide and/or mixtures thereof, under judiciously controlled experimental conditions. Thiosulfate and sulfite were quantitated by differential pulse polarography at dropping mercury anodes via reactions involving formation of thiosulfato- and sulfitomercurates. 14 refs., 2 figs.

Jordan, J. (Pennsylvania State Univ., University Park (USA)); Talbott, J. (Med-Chek Labs., Pittsburgh, PA (USA)); Yakupkovic, J. (Union Camp Corp., Princeton, NJ (USA))

1989-06-01

93

Regional river sulfur runoff  

SciTech Connect

The water and sulfur runoff data for 54 large river basins were assembled, covering 65% of the nondesert land area of the world. The sulfur concentration ranges from 0.5 mg S/L for the West African rivers Niger and Volta to 100 mg S/L in the Colorado River; the world average is 3.2 mg S/L. The concentrations in central and eastern Europe as well as central and eastern North America exceed 8 mg S/L. The sulfur runoff density is also highest in the river basins over these industrialized regions, exceeding 2 g S/m/sup 2//yr. However, high sulfur runoff density in excess of 3 g S/m/sup 2//yr is also measured over the Pacific islands New Zealand and New Guinea and the archipelagos of Indonesia and the Philippines. The natural background sulfur runoff was estimated by assuming that South America, Africa, Australia, and the Pacific Islands are unperturbed by man and that the average river sulfur concentration is in the range 1--3 mg S/L. Taking these background concentration values, the man-induced sulfur runoff for Europe ranges between 2 and 8 times the natural flow, and over North America, man's contribution ranges between 1 and 5 times the natural runoff. The global sulfur flow from nondesert land to the oceans and the Caspian Sea is estimated as 131 Tg S/yr, of which 46--85 Tg S/yr is attributed to natural causes. The regional river sulfur runoff pattern discussed in this paper does not have enough spatial resolution to be directly applicable to studies of the environmental effects of man-induced sulfur flows. However, it points to the continental-size regions where those perturbations are most evident and to the magnitude of the perturbations as expressed in units of the natural flows.

Husar, R.B.; Husar, J.D.

1985-01-20

94

Analysis of low concentration reduced sulfur compounds (RSCs) in air: storage issues and measurement by gas chromatography with sulfur chemiluminescence detection.  

PubMed

Reduced sulfur compounds (RSCs) were measured at low concentrations in small volume air samples using a cryo-trapping inlet system and gas chromatograph outfitted with a sulfur chemiluminescence detector (GC-SCD). The relative sensitivity of the system to the RSCs follows the sequence H(2)Ssulfur mass injected, we found that the response properties for each RSC differed. At concentrations below 2ppb, the compounds H(2)S and CH(3)SH have diminished responses, leading to larger measurement uncertainties. Two generations of commercially available SilcoCan canisters were tested to evaluate the relative RSC loss due to storage in the canister and loss of inertness because of coating age. The older generation canister (>6 years from initial coating) saw significant loss of H(2)S and CH(3)SH within 2 days, while the more recent generation canister (<1 year from initial coating) yielded percent recoveries of RSCs in the range of 85% (H(2)S and CH(3)SH) to 95% (OCS, DMS and CS(2)) after 7 days of storage, suggesting that these canisters may be suitable for the short-term storage of low level RSCs. The development of this low concentration, low sample volume method is well suited for measuring RSC gas fluxes from natural soils in laboratory incubations and in field flux chamber studies. PMID:22265544

Khan, M A H; Whelan, M E; Rhew, R C

2012-01-15

95

Reduced sulfur compounds in the atmosphere of sewer networks in Australia: geographic (and seasonal) variations.  

PubMed

The management of odorous emissions from sewer networks has become an important issue for sewer system operators resulting in the need to better understand the composition of reduced sulfur compounds (RSCs). Gaseous RSCs including hydrogen sulfide (H2S), methanethiol (MeSH), dimethyl sul?de (DMS), carbon disul?de (CS2), dimethyl disul?de (DMDS) and dimethyl trisulfide (DMTS) were measured in the atmosphere of selected sewer networks in two major Australian cities (Sydney and Melbourne) during 2011-2012. The RSC concentrations in the sewer air were detected in a highly variable range. H2S and MeSH were found at the highest concentrations, followed by DMS (39.2-94.0 ?g/m(3)), CS2 (18.3-19.6 ?g/m(3)), DMDS (7.8-49.6 ?g/m(3)) and DMTS (10.4-35.3 ?g/m(3)). Temporal trends in the occurrence of targeted RSCs were observed and the highest sulfur concentration occurred either in summer or spring, which are typically regarded as the warmer seasons. Statistical significant difference in the magnitude of targeted RSCs was found between samples collected in Sydney and Melbourne. PMID:24647180

Wang, B; Sivret, E C; Parcsi, G; Le, N M; Kenny, S; Bustamante, H; Stuetz, R M

2014-01-01

96

Electrochemistry of inorganic sulfur compounds and electroanalytical methods for synfuel process streams  

SciTech Connect

Electrode reactions of the following oxidation states of sulfur were investigated by differential pulse voltammetry (DPV): +4(SO/sub 2/, SO/sub 3/=), +2.5(S/sub 4/O/sub 6/=), +2(S/sub 2/O/sub 3/=), zero (elemental sulfur and the polysulfidic component of S/sub x/=). Sensitive, selective, precise and accurate DPV methods were developed for the quantitative speciation of sulfur. Indicator electrodes included glassy carbon anodes in Levich's rotated disk configuration and dropping mercury anodes and cathodes. The speciation of aqueous synfuel process streams revealed that liquefaction technologies produced relatively higher concentrations of sulfur contaminants in the oxidation states -2 and 0, while gasification processes yielded comparably more S(+2) and S(+4). Electrooxidation of tetrathionate to sulfate was conclusively substantiated.

Ankabrandt, S.J.

1981-01-01

97

Analysis of sulfur compounds from the in-oven roast beef aroma by comprehensive two-dimensional gas chromatography.  

PubMed

After a previous investigation of carbonyl compounds in the in-oven top note of roast beef [S. Rochat, A. Chaintreau, J. Agric. Food Chem. 53 (2005) 9578], this paper focuses on the role of sulfur compounds. Because of the complexity of the roast beef headspace where sulfur compounds occur in trace amounts, a high resolution and sensitive technique, comprehensive two-dimensional gas chromatography (GC x GC), was chosen, that allowed the detection of thousands of compounds in the oven headspace. As identifying all of them would be too time consuming, a strategy had to be developed to extract the pertinent information. More than 70 sulfur compounds were found by GC x GC hyphenated to time-of-flight mass spectrometry (TOF-MS), and the identity of 50 of them was confirmed. To overcome the absence of many retention indices in databanks, the missing values were simulated using a multiple linear regression to help the peak identification. The selection of the most important sulfur odorants from this list was achieved by GC-olfactometry, using the GC-"SNIF" technique. Seven compounds have been found for the first time in beef aroma, of which only one has been previously found in nature. PMID:17343865

Rochat, Sabine; Laumer, Jean-Yves de Saint; Chaintreau, Alain

2007-04-13

98

Evolution and Ecology of Microbes Dissimilating Sulfur Compounds: Insights from Siroheme Sulfite Reductases  

Microsoft Academic Search

Sulfur microorganisms have been thriving on Earth since the dawn of life and are still of central importance for the functioning\\u000a of modern ecosystems. Here, we summarize the current perception of the evolution of dissimilatory siroheme sulfite reductases\\u000a (DSRs), antique key enzymes in the energy metabolism of sulfur microbes. We further give recent examples of the diversity\\u000a and ecology of

Alexander Loy; Stephan Duller; Michael Wagner

99

Sulfuric Acid on Europa  

NASA Technical Reports Server (NTRS)

Frozen sulfuric acid on Jupiter's moon Europa is depicted in this image produced from data gathered by NASA's Galileo spacecraft. The brightest areas, where the yellow is most intense, represent regions of high frozen sulfuric acid concentration. Sulfuric acid is found in battery acid and in Earth's acid rain.

This image is based on data gathered by Galileo's near infrared mapping spectrometer.

Europa's leading hemisphere is toward the bottom right, and there are enhanced concentrations of sulfuric acid in the trailing side of Europa (the upper left side of the image). This is the face of Europa that is struck by sulfur ions coming from Jupiter's innermost moon, Io. The long, narrow features that crisscross Europa also show sulfuric acid that may be from sulfurous material extruded in cracks.

Galileo, launched in 1989, has been orbiting Jupiter and its moons since December 1995. JPL manages the Galileo mission for NASA's Office of Space Science, Washington DC. JPL is a division of the California Institute of Technology, Pasadena, CA.

1999-01-01

100

Emission characteristics of nitrogen- and sulfur-containing odorous compounds during different sewage sludge chemical conditioning processes.  

PubMed

Chemical conditioners are often used to enhance sewage sludge dewaterability through altering sludge properties and flocs structure, both affect odorous compounds emissions not only during sludge conditioning but also in subsequent sludge disposal. This study was to investigate emission characteristics of ammonia (NH(3)), sulfur dioxide (SO(2)), hydrogen sulfide (H(2)S) and carbonyl sulfide (COS) generated from sewage sludge conditioned by three representative conditioners, i.e., organic polymers, iron salts and skeleton builders, F-S (Fenton's reagent and skeleton builders) composite conditioner. The results demonstrate that polyacrylamide (PAM) has an insignificant effect on emission characteristics of nitrogen- and sulfur-containing odorous compounds, because the properties, sulfur and nitrogen speciations are similar in PAM-conditioned sludge and raw sludge (RS). Significant increases of SO(2) and H(2)S emissions in the H(2)SO(4) conditioning process were observed due to the accelerated decomposition of sulfur-containing amino acids in acidic environment. Fenton peroxidation facilitates the formation of COS. CaO can reduce sulfur-containing gases emission via generation of calcium sulfate. However, under strong alkaline conditions, free ammonia or protonated amine in sludge can be easily converted to volatile ammonia, resulting in a significant release of NH(3). PMID:22902143

Liu, Huan; Luo, Guang-Qian; Hu, Hong-Yun; Zhang, Qiang; Yang, Jia-Kuan; Yao, Hong

2012-10-15

101

Comparison of volatile sulfur compound concentrations measured with a sulfide detector vs. gas chromatography.  

PubMed

The accuracy of the Halimeter, an inexpensive, simple instrument that measures total breath volatile sulfur compounds (VSCs), has not been adequately tested. We compared Halimeter measurements with those obtained with a specific and sensitive gas chromatographic (GC) technique. The Halimeter gave different, biexponential responses to a constant concentration of different VSCs: The relative response rate and sensitivity were hydrogen sulfide > methyl mercaptan > dimethylsulfide. The transient peak VSC concentration of oral samples was reached long before the sulfide detector fully responded. The GC measurement of initial total VSCs in breath samples was 2.7+/-0.48 times greater than the peak concentration of the Halimeter. However, the plateau phase measurement of the Halimeter was 25% greater than that of GC. While GC and Halimeter measurements positively correlated, appreciable differences were observed. In studies where relatively precise VSC measurements are required, GC is the preferable technique. PMID:11827259

Furne, J; Majerus, G; Lenton, P; Springfield, J; Levitt, D G; Levitt, M D

2002-02-01

102

Roles of methanogens on volatile organic sulfur compound production in anaerobically digested wastewater biosolids.  

PubMed

Land application of wastewater biosolids is both economical and beneficial to resource recycling. However, this environmentally friendly practice can be at risk due to odor complaints. Volatile organic sulfur compounds (VOSCs) including methanethiol, dimethyl sulfide, and dimethyl disulfide, have been identified as major contributors to biosolids odor. In this study, methanogens were shown to play a key role in removing VOSCs and reducing odors, and methane production was related to reduced VOSC production. Factors influencing the growth of methanogens such as the shear during dewatering and storage temperature showed a strong impact on net odor production. Examination of the microbial communities of both bacteria and archaea indicated a simplified archaeal community in biosolids, which is susceptible to environmental perturbations. Therefore, one possible odor control strategy is the preservation and enhancement of the methanogenic population during biosolids storage. PMID:16180410

Chen, Y; Higgins, M J; Maas, N A; Murthy, S N; Toffey, W E; Foster, D J

2005-01-01

103

A review of methods for the determination of reduced sulfur compounds (RSCs) in air.  

PubMed

The importance of reduced sulfur compounds (RSCs) in air is well-known for its significant effect on global atmospheric chemistry and malodor and quality of life. In this review, methodological approaches commonly employed for the analysis of RSCs such as hydrogen sulfide, methane thiol, dimethyl sulfide, carbon disulfide, and dimethyl disulfide in air are described. To this end, we focus on gas chromatography (GC) because it is the most feasible, frequently used, and widely accepted approach for the analysis of RSC in air. The advantages and possible limitations related to sampling and/or preconcentration methods are also discussed. The relative performance of different GC-based detection methodologies is evaluated in terms of basic quality assurance. Some alternative methods (i.e., other than GC) that deal with the determination of RSCs in air matrices are also discussed briefly. Finally, this review addresses the methodological developments of RSC analysis by highlighting current limitations and future developments. PMID:19534108

Pandey, Sudhir Kumar; Kim, Ki-Hyun

2009-05-01

104

Sulfur spring dermatitis.  

PubMed

Thermal sulfur baths are a form of balneotherapy promoted in many cultures for improvement of skin conditions; however, certain uncommon skin problems may occur after bathing in hot sulfur springs. We report the case of a 65-year-old man who presented with multiple confluent, punched-out, round ulcers with peripheral erythema on the thighs and shins after bathing in a hot sulfur spring. Histopathologic examination revealed homogeneous coagulation necrosis of the epidermis and papillary dermis. Tissue cultures showed no evidence of a microbial infection. The histopathologic findings and clinical course were consistent with a superficial second-degree burn. When patients present with these findings, sulfur spring dermatitis should be considered in the differential diagnosis. Moreover, the patient's clinical history is crucial for correct diagnosis. PMID:25474449

Lee, Chieh-Chi; Wu, Yu-Hung

2014-11-01

105

CATALYTIC OXIDATION OF TOTAL REDUCED SULFUR COMPOUNDS FROM PULP AND PAPER INDUSTRIES WITH OZONE AS AN OXIDANT  

EPA Science Inventory

Pulp and paper industry generates more than 144 million lb of VOCs per year including a range of reduced sulfur compounds (TRS) such as dimethyl sulfide (DMS), dimethyl disulfide (DMDS), methane thiol (MT) and H2S that are odorous, toxic and contribute to smog formation. Thermal ...

106

Geochemical and sulfur isotope signatures of microbial activity in acidic and sulfuric hot springs, northern Taiwan  

NASA Astrophysics Data System (ADS)

Acidic and sulfuric hot springs are natural habitats for thermophilic sulfur-utilizing microorganisms. Integration of bioenergetic evaluation, molecular analysis and stable isotopic signatures may be able to exhibit a full view of microbial activity in such an extreme environment. Widely distributed hot springs hosted by the Tatung volcano group in northern Taiwan provide a chance to evaluate the interplay between geochemical variation and microbial metabolism especially for sulfur. Several hot spring ponds varying in sizes and geochemical characteristics were studied to reveal the possible control of fluid compositions on microbial metabolisms, and vice versa. Sulfate, sulfide, elemental sulfur and dissolved organic carbon were available in spring water and sediments in the ponds. Dominant microbial metabolisms inferred from the bioenergetic evaluation were aerobic oxidations of various reduced compounds, including elemental sulfur, pyrite, ferrous iron and organic carbon. Sulfate and sulfur reductions were thermodynamically favorable but provided less energy flux, while sulfur disproportionation was thermodynamically incapable. The analyses of 16S rRNA genes extracted from the spring water and sediments indicated that aerobic oxidation of sulfur, hydrogen or organic carbon and anaerobic elemental sulfur reduction were possible metabolisms. Since the major portion of 16S rRNA sequences were affiliated with unclassified environmental sequences, their potential metabolisms remained obscure. Sulfur isotopic compositions of dissolved sulfate, pyrite and elemental sulfur exhibited significant variations among the different hot spring ponds. Apparently, the microbial effects on the sulfur isotopic signatures were various. A disproportionation reaction of volcanic gas was required to account for high sulfur isotope difference between sulfate and reduced sulfur in the large hot ponds. In contrary, abiotic or microbial oxidation of reduced sulfur might be dominant in the small ponds, where only small sulfur isotopic fractionation occurred among the sulfur species. Both sulfate and elemental sulfur reduction could not be recognized as the sulfide in all ponds were not the most depleted in S-34.

Wang, P.; Chen, K.; Cheng, T.; Hsieh, H.; Lin, L.

2009-12-01

107

Variation of some fermentative sulfur compounds in Italian "millesime" classic sparkling wines during aging and storage on lees.  

PubMed

Fermentative sulfur compounds are recognized as strongly affecting wine aroma, mainly as off-flavors, but recently also as possible positive contributors to wine quality and typicity in still wines. Nevertheless, no evidence has been provided for the influence of these molecules on sparkling wine aroma, except for peculiar volatile thiols found in French Champagne. According to the traditional method, the second fermentation, occurring in sealed bottles, is the essence of the procedure. After this fermentation, sparkling wine is aged on yeast lees for a period ranging from a few months to several years so that yeast autolysis can take place. So far, no evidence is provided for the effect of yeast contact duration on the level of sulfur compounds. Following a HS-SPME/GC-MS method, 13 sulfur compounds, that is, ethylmercaptan, dimethyl sulfide, diethyl sulfide, dimethyl disulfide, diethyl disulfide, methyl thioacetate, ethyl thioacetate, 2-mercaptoethanol, 2-(methylthio)-1-ethanol, 3-(methylthio)-1-propanol, 4-(methylthio)-1-butanol, benzothiazole, and 5-(2-hydroxyethyl)-4-methylthiazole, were quantified in several Italian sparkling wines, produced according to the traditional method in two wineries from Trentino-South Tyrol, region. Additionally, the influence of winemaking technology differences and vintage effects on the evolution of the quoted sulfur compounds was considered. This investigation was carried out by coupling the HS-SPME data with those obtained by SPE method and relevant to other volatile compounds, which are considered as winemaking markers. This work furnished the first evidence of the effect of aging and lees contact at different storage temperatures on the levels of these analytes in sparkling wines. Significant increments were observed for dimethyl sulfide, diethyl sulfide, 2-(methylthio)-1-ethanol, 3-(methylthio)-1-propanol, and 4-(methylthio)-1-butanol during aging with a different variation slope possibly due to the remarkably different storage temperatures. No clear influence of lees contact duration was found for the majority of the sulfur compounds considered. PMID:20806972

Fedrizzi, Bruno; Magno, Franco; Finato, Fabio; Versini, Giuseppe

2010-09-01

108

Kinetics of oxidation of odorous sulfur compounds in aqueous alkaline solution with H2O2.  

PubMed

Sulfur species oxidation is a crucial issue wastewater treatment. The production of sulfur compounds like H2S,CH3SH, C2H5SH, disulfides and dimethyle sulfide generates odorous nuisances for the neighborhood. The oxidation of these species by H2O2 in alkaline solution has been investigated. The results showed that thiols CH3SH and C2H5SH react with H202 only in their dissociated form RS- with rate constants respectively k = 8.81 +/- 0.48 M-1s-1 and 8.37 +/- 0.63 M-1.s-1. Mercaptans oxidation produces 100 % of dimethyldisulfide or diethyldisulfide. The oxidation of disulfides shows a difference of reactivity between H2O2 and HO2- towards sulfur species. Increasing the pH accelerates significantly the reactions in the case of CH3SSCH3. The oxidation rate can be described as: r = k[RSSR][H2O2][RSSR][H2O2] + k[RSSR][HO2-] [RSSR][HO2-] with k[RSSR][H2O2] = 1.2 x 10(-4) +/- 0.2 x 10(-4) M-1s-1 and k[RSSR][HO2-] = 3.4 x 10(-4) +/- 0.6 x 10(-4) M-1.s-1 for CH3SSCH3. Dimethyl sulfide presents a reactivity different from disulfides. The oxidation rate can also be described as: r = k[CH3SCH3][H2O21][CH3SCH3][H2O2] + k[CH3SCH3][HO-] [CH3SCH3][HO2-], however, oxidation rate decreases with pH increase. k[CH3SCH3][H2O2] = 12.8 x 10(-3) +/- 0.96 x 10(-3) M-1.s-1 and k[CH3SCH3][HO2-] = 4 x 10(-3) +/- 0.3 x 10(-3) M-1.s-1. PMID:11766036

Feliers, C; Patria, L; Morvan, J; Laplanche, A

2001-10-01

109

Bacterial ethane formation from reduced, ethylated sulfur compounds in anoxic sediments  

USGS Publications Warehouse

Trace levels of ethane were produced biologically in anoxic sediment slurries from five chemically different aquatic environments. Gases from these locations displayed biogenic characteristics, having 12C-enriched values of ??13CH4 (-62 to -86%.), ??13C2H6 (-35 to -55%.) and high ratios (720 to 140,000) of CH4 [C2H6 + C3H8]. Endogenous production of ethane by slurries was inhibited by autoclaving or by addition of the inhibitor of methanogenic bacteria, 2-bromoethanesulfonic acid (BES). Ethane formation was stimulated markedly by ethanethiol (ESH), and, to a lesser extent, by diethylsulfide (DES). Formation of methane and ethane in ESH- or DES-amended slurries was blocked by BES. Experiments showed that ethionine (or an analogous compound) could be a precursor of ESH. Ethylamine or ethanol additions to slurries caused only a minor stimulation of ethane formation. Similarly, propanethiol additions resulted in only a minor enhancement of propane formation. Cell suspensions of a methyltrophic methanogen produced traces of ethane when incubated in the presence of DES, although the organism did not grow on this compound. These results indicate that methanogenic bacteria produce ethane from the traces of ethylated sulfur compounds present in recent sediments. Preliminary estimates of stable carbon isotope fractionation associated with sediment methane formation from dimethylsulfide was about 40%., while ethane formation from DES and ESH was only 4. 6 and 6.5%., respectively. ?? 1988.

Oremland, R.S.; Whiticar, Michael J.; Strohmaier, F.E.; Kiene, R.P.

1988-01-01

110

Measurement of air-surface exchange of speciated nitrogen and sulfur compounds using a modified MARGA 2S: ? Concentrations and fluxes above a grass field  

EPA Science Inventory

Improved measurement methods are needed to characterize dry deposition of sulfur and nitrogen compounds to assess ecosystem exposure to nutrients and acidifying compounds and to develop atmospheric deposition budgets in support of critical loads assessments. The purpose of this s...

111

Certain features of catalytic conversion, under pressure, of organic sulfur compounds and asphaltenes present in residual fuels  

Microsoft Academic Search

A study has been made of the influence of the physicochemical properties of CoO-MoOâ-AlâOâ catalysts (surface concentration of MoOâ, degree of crystallinity of molybdenum compounds, pore structure) on the character of conversion of asphaltenes and organic sulfur compounds at 653°K under a pressure of 10 MPa. The conversion of the colloidal particles of the asphaltenes under pressure is basically different

L. P. Milova; M. A. Lure; N. M. Zaidman; L. N. Vetlugina; L. M. Plyasova

2009-01-01

112

Antioxidant and anticancer properties and mechanisms of inorganic selenium, oxo-sulfur, and oxo-selenium compounds.  

PubMed

Inorganic selenium and oxo-sulfur compounds are widely available in dietary supplements and have been extensively studied for their antioxidant and anticancer properties. Although many in vivo and clinical trials have been conducted using these compounds, their biochemical and chemical mechanisms of efficacy are the focus of much current research. This review discusses the ability of inorganic selenium compounds, such as selenite, and selenate, to prevent damage from reactive oxygen species as well as their ability to promote cell death by reactive oxygen species generation. Oxo-sulfur and selenium compounds, such as allicin, dimethyl sulfone, methionine sulfoxide, and methylselenenic acid also have similar abilities to act as both antioxidants and pro-oxidants, but the mechanisms for these behaviors are distinctly different from those of the inorganic selenium compounds. The antioxidant and pro-oxidant properties of these small-molecule sulfur and selenium compounds are extremely complex and often greatly depend on experimental conditions, which may explain contradictory literature reports of their efficacy. PMID:20632128

Ramoutar, Ria R; Brumaghim, Julia L

2010-09-01

113

THE ANTIBACTERIAL PROPERTIES OF SULFUR  

PubMed Central

1. Saturated solutions of sulfur in alcohol (alcohol-sulfur) when diluted with broth are inhibitory to the growth of various Gram-positive bacteria and to C. hominis. By an arbitrary method of unitage with S. aureus as the test organism, our alcohol-sulfur contains 1,600 to 2,000 units per cc. and one unit contains between 0.24 and 0.34 gamma sulfur. The activity of a preparation is in general directly proportional to its sulfur content. 2. Solutions of sulfur in carbowax (carbowax-sulfur) when diluted with broth are likewise inhibitory to the growth of various Gram-positive bacteria and to C. hominis. When S. aureus is used as test organism, 1 unit contains between 0.1 and 0.2 gamma sulfur. The activity of these preparations is also in general directly proportional to their sulfur content. 3. Carbowax-sulfur when incorporated in agar in 1–500 to 1–2,000 dilution inhibits the growth of various Gram-positive aerobic and anaerobic bacteria, C. hominis, and certain dermatophytes. 4. Our experiments appear to show that both alcohol-sulfur and carbowax-sulfur owe their inhibitory properties to the sulfur particles that are dispersed throughout the medium when these sulfur preparations are diluted with broth. The inhibitory effect of these particles may or may not be due to a combination of the sulfur particles with substances in the medium in which they are suspended. 5. Evidence suggests that the activity of both alcohol-sulfur and carbowax-sulfur is due to sulfur in the same form. The inhibitory effect is characterized by prolonged bacteriostasis with similar activity over a wide range of dilutions. There is no evidence of true bactericidal action even with the highest concentrations used. PMID:19871634

Weld, Julia T.; Gunther, Anne

1947-01-01

114

Thermochemical transformation of sulfur compounds in Japanese domestic Allium, Allium victorialis L.  

PubMed

Sulfur compounds contributed to the health promotion in Allium species are produced via enzymic and thermal reactions. Potent antithrombotic agents which have been identified as allyl trisulfides, dithiins, and ajoene in garlic (A. sativum) and caucas (A. victorialis) are thermochemically transformed from allicin (allyl 2-propenethiosulfinate). The leaves and stems of Japanese domestic Allium plant, A. victorialis L. which is widely distributed in the northern part of Japan, under the name "Gyoja-ninniku" is a nutritious vegetable. The significant flavor compounds of caucas are methyl allyl disulfide (Chinese chive odor), diallyl disulfide (garlic-like odor), and dimethyl disulfide and methyl allyl trisulfide (pickles-like odor) among more than 85 peaks on the gas chromatogram. 2-Vinyl-4H-1,3-dithiin and 3,4-dihydro-3-vinyl-1,2-dithiin as platelet aggregation inhibitors were found eliminated in dichloromethane extract of caucas. The significant health promoting factors, allyl trisulfides and dithiins were relatively increased when caucas was cooked on a frying pan. PMID:11237191

Nishimura, H; Takahashi, T; Wijaya, C H; Satoh, A; Ariga, T

2000-01-01

115

Emission of volatile sulfur compounds during composting of municipal solid waste (MSW).  

PubMed

Volatile sulfur compounds (VSCs) are the main source for malodor from composting plants. In this study, the VSCs generated from composting of 15-80 mm municipal solid waste (T0), kitchen waste (T1) and kitchen waste mixed dry cornstalks (T2) were measured in 60 L reactors with forced aeration for a period of 30 days. The VSCs detected in all treatments were hydrogen sulfide (H2S), methyl mercaptan (MM), dimethyl sulfide (DMS), carbon bisulfide (CS2) and dimethyl disulfide (DMDS). Over 90% of the VSCs emissions occurred during the first 15 days, and reached their peak values at days 4-7. The emission profiles of five VSCs species were significantly correlated with internal materials temperature and outlet O2 concentration (p<0.05). Total emissions of the VSCs were 216.1, 379.3 and 126.0 mg kg(-1) (dry matter) for T0, T1 and T2, respectively. Among the five VSCs, H2S was the most abundant compound with 39.0-43.0% of total VSCs released. Composting of kitchen waste from separate collection posed a negative influence on the VSC and leachate production because of its high moisture content. An addition of dry cornstalks at a mixing ratio of 4:1 (wet weight) could significantly reduce the VSCs emissions and avoid leachate. Compared to pure kitchen waste, VSCs were reduced 66.8%. PMID:23312132

Zhang, Hongyu; Schuchardt, Frank; Li, Guoxue; Yang, Jinbing; Yang, Qingyuan

2013-04-01

116

Volatile organic sulfur compounds in anaerobic sludge and sediments: biodegradation and toxicity.  

PubMed

A variety of environmental samples was screened for anaerobic degradation of methanethiol, ethanethiol, propanethiol, dimethylsulfide, and dimethyldisulfide. All sludge and sediment samples degraded methanethiol, dimethylsulfide, and dimethyldisulfide anaerobically. In contrast, ethanethiol and propanethiol were not degraded by the samples investigated under any of the conditions tested. Methanethiol, dimethylsulfide, and dimethyldisulfide were mainly degraded by methanogenic archaea. In the presence of sulfate and the methanogenic inhibitor bromoethane sulfonate, degradation of these compounds coupled to sulfate reduction occurred as well, but at much lower rates. Besides their biodegradability, also the toxicity of methanethiol, ethanethiol, and propanethiol to methanogenesis with methanol, acetate, and H2/CO2 as the substrates was assessed. The 50% inhibition concentration of methanethiol on the methane production from these substrates ranged between 7 and 10 mM. The 50% inhibition concentration values of ethanethiol and propanethiol for the degradation of methanol and acetate were between 6 and 8 mM, whereas hydrogen consumers were less affected by ethanethiol and propanethiol, as indicated by their higher 50% inhibition concentration (14 mM). Sulfide inhibited methanethiol degradation already at relatively low concentrations: methanethiol degradation was almost completely inhibited at an initial sulfide concentration of 8 mM. These results define the operational limits of anaerobic technologies for the treatment of volatile organic sulfur compounds in sulfide-containing wastewater streams. PMID:17220077

van Leerdam, Robin C; de Bok, Frank A M; Lomans, Bart P; Stams, Alfons J M; Lens, Piet N L; Janssen, Albert J H

2006-12-01

117

Sulfur Substitution in Oxyanions.  

NASA Astrophysics Data System (ADS)

Sulfide can react with oxyanions in two ways. In anions such as chromate, iodate or permanganate, the central metal(loid) is reduced rapidly. In anions such as molybdate, arsenate or antimonate, sulfur atoms substitute for oxygen atoms in the first coordination sphere. In the latter cases, the central metal(loid) often retains its high oxidation state in the final thioanion; however lower valent species, which tend to be coordinatively more labile, may be important reaction intermediates. Replacement of oxygen by sulfur "softens" oxyanions, in some cases making them strong binders of soft metals, like Cu, Ag, Au and Hg. These changes also can profoundly affect the geochemical fate of the metal(loids). Sulfur substitution in oxyanions can be extremely sluggish. Recently, computational chemistry has begun to yield information about sulfur substitution reactions that are too slow to be studied experimentally but yet are potentially important in geochemistry. Thioperrhenates, thiovanadates and thiotungstates are species whose geochemical roles, if any, remain to be determined. It is possible that sulfur substitution reactions are more important under hydrothermal conditions than at ambient temperatures. For example, germanate dominates the ambient-temperature chemistry of Ge, but in hydrothermal deposits this element occurs commonly in sulfide minerals.

Helz, G. R.

2008-12-01

118

Natural sulfur dioxide emissions from sulfuric soils  

NASA Astrophysics Data System (ADS)

Soils have long been recognised as sulfur dioxide (SO 2) sinks, but we show that they can also be sources of atmospheric SO 2. Using static chambers and micrometeorological techniques, we have measured emissions of SO 2 from coastal lowland soils containing sulfides (mostly pyrite), commonly referred to as acid sulfate soils in Australia. SO 2 evolution seems coupled to evaporation of soil water containing sulfite. The global emissions of S from acid sulfate soils is estimated at about 3 Tg/year, which is of the same order as emissions from terrestrial biogenic sources and biomass burning and is about 3% of known anthropogenic emissions of S.

Macdonald, Bennett C. T.; Denmead, O. Tom; White, Ian; Melville, Michael D.

119

Process for removing sulfur from coal  

DOEpatents

A process is disclosed for the removal of divalent organic and inorganic sulfur compounds from coal and other carbonaceous material. A slurry of pulverized carbonaceous material is contacted with an electrophilic oxidant which selectively oxidizes the divalent organic and inorganic compounds to trivalent and tetravalent compounds. The carbonaceous material is then contacted with a molten caustic which dissolves the oxidized sulfur compounds away from the hydrocarbon matrix.

Aida, T.; Squires, T.G.; Venier, C.G.

1983-08-11

120

Sodium sulfur battery seal  

SciTech Connect

This disclosure is directed to an improvement in a sodium sulfur battery construction in which a seal between various battery compartments is made by a structure in which a soft metal seal member is held in a sealing position by holding structure. A pressure applying structure is used to apply pressure on the soft metal seal member when it is being held in sealing relationship to a surface of a container member of the sodium sulfur battery by the holding structure. The improvement comprises including a thin, well-adhered, soft metal layer on the surface of the container member of the sodium sulfur battery to which the soft metal seal member is to be bonded.

Mikkor, Mati (Ann Arbor, MI)

1981-01-01

121

Interstellar sulfur chemistry  

NASA Technical Reports Server (NTRS)

The results of a chemical model of SO, CS, and OCS chemistry in dense clouds are summarized. The results are obtained from a theoretical study of sulfur chemistry in dense interstellar clouds using a large-scale time-dependent model of gas-phase chemistry. Among the results are the following: (1) owing to activation energy, the reaction of CS with O atoms is efficient as a loss mechanism of CS during the early phases of cloud evolution or in hot and oxygen-rich sources such as the KL nebula; (2) if sulfur is not abnormally depleted in dense clouds, then the observed abundances of SO, SO2, H2S, CS, OCS, H2CS, and SiS indicate that sulfur is mostly atomic in dense clouds; and (3) OCS is stable against reactions with neutral atoms and radicals in dense clouds.

Prasad, S. S.; Huntress, W. T., Jr.

1980-01-01

122

40 CFR 50.5 - National secondary ambient air quality standard for sulfur oxides (sulfur dioxide).  

Code of Federal Regulations, 2012 CFR

...ambient air quality standard for sulfur oxides (sulfur dioxide). 50.5 Section...ambient air quality standard for sulfur oxides (sulfur dioxide). (a) The...shall be rounded up). (b) Sulfur oxides shall be measured in the ambient...

2012-07-01

123

40 CFR 50.5 - National secondary ambient air quality standard for sulfur oxides (sulfur dioxide).  

Code of Federal Regulations, 2013 CFR

...ambient air quality standard for sulfur oxides (sulfur dioxide). 50.5 Section...ambient air quality standard for sulfur oxides (sulfur dioxide). (a) The...shall be rounded up). (b) Sulfur oxides shall be measured in the ambient...

2013-07-01

124

Thiosulfate and Sulfur Oxidation in Purple Sulfur Bacteria  

Microsoft Academic Search

In chemotrophic and phototrophic sulfur oxidizers that do not form sulfur deposits a periplasmic thiosulfate-oxidizing multienzyme\\u000a complex (Sox complex) has been described to be responsible for formation of sulfate from thiosulfate. In the anoxygenic phototrophic\\u000a sulfur bacterium Allochromatium vinosum intracellular sulfur globules are an obligate intermediate during the oxidation of thiosulfate to sulfate. Despite this fundamental\\u000a difference A. vinosum possesses

Frauke Grimm; Bettina Franz; Christiane Dahl

125

Assessment of reduced sulfur compounds in ambient air as malodor components in an urban area  

NASA Astrophysics Data System (ADS)

Long-term monitoring of reduced sulfur compounds (RSCs: hydrogen sulfide (H 2S), methanethiol (CH 3SH), dimethyl sulfide (DMS), and dimethyl disulfide (DMDS)) in ambient air was made using an on-line GC system at an odor monitoring station in the city of Ansan, South Korea (August 2005-December 2007). The results were examined to assess the status of RSC pollution, its relative contribution to malodor, and the controlling factors of its occurrence. H 2S (mean of 0.27 ppb) was eminent in terms of both magnitude and occurrence frequency, while others were not with mean values of 0.11 (DMDS), 0.10 (DMS), and 0.07 ppb (CH 3SH). Unlike others, the temporal trends of H 2S were best represented by the combined effects of its source processes and meteorological conditions. The results of correlation analysis indicate strong correlations between RSCs and water-related parameters (e.g., rainfall, dew point, and relative humidity). The role of RSCs as malodor component appears to be pronounced during nighttime, especially in summer. If the relative contribution of RSCs to malodor is assessed by means of the sum of odor intensity (SOI), its impact is relatively low, with an SOI value of 1.22 (weak odor strength). Consequently, a more deliberate approach may be needed to effectively assess odor occurrence patterns in ambient air.

Susaya, Janice; Kim, Ki-Hyun; Phan, Nhu-Thuc; Kim, Jo-Chun

2011-07-01

126

Origins of sulfur compounds in the atmosphere of a zone of high productivity (Gulf of Guinea)  

SciTech Connect

Recent observations have suggested substantial emission of sulfur compounds by oceanic water which could explain the presence of SO/sub 2/ and SO/sup +//sub 4/ in the air above these waters. The emission is thought to increase with the productivity of the oceanic zones. This point is discussed in relation to the Gulf of Guinea, a zone of high productivity. During the first two campaigns between Dakar, Abidjan, and the Gulf of Guinea SO/sup +//sub 4/ concentrations were measured in the air. Between Abidjan and the Gulf of Guinea the atmospheric SO= /sub 4/ concentrations decreased from 800 to 400 ng m/sup -3/. During the third campaign, between Abidjan and the South Equatorial Current (latitude 1/sup 0/S), the H/sub 2/S and SO/sub 2/ concentrations were measured. The mean H/sub 2/S concentration was 20 ng m/sup -3/, and that of SO/sub 2/ varied between 120 and under 50 ng m/sup -3/. The origins of SO/sub 2/ and SO/sup +//sub 4/ in the air of this area are discussed through the daily variations of the H/sub 2/S content of the air and a contribution from the forested zones of West Africa.

Delmas, R.; Servant, J.

1982-12-20

127

Inhibition of microbial growth by ajoene, a sulfur-containing compound derived from garlic.  

PubMed

Ajoene, a garlic-derived sulfur-containing compound that prevents platelet aggregation, exhibited broad-spectrum antimicrobial activity. Growth of gram-positive bacteria, such as Bacillus cereus, Bacillus subtilis, Mycobacterium smegmatis, and Streptomyces griseus, was inhibited at 5 micrograms of ajoene per ml. Staphylococcus aureus and Lactobacillus plantarum also were inhibited below 20 micrograms of ajoene per ml. For gram-negative bacteria, such as Escherichia coli, Klebsiella pneumoniae, and Xanthomonas maltophilia, MICs were between 100 and 160 micrograms/ml. Ajoene also inhibited yeast growth at concentrations below 20 micrograms/ml. The microbicidal effect of ajoene on growing cells was observed at slightly higher concentrations than the corresponding MICs. B. cereus and Saccharomyces cerevisiae were killed at 30 micrograms of ajoene per ml after 24 h of cultivation when cultivation was started at 10(5) cells per ml. However, the minimal microbicidal concentrations for resting cells were at 10 to 100 times higher concentrations than the corresponding MICs. The disulfide bond in ajoene appears to be necessary for the antimicrobial activity of ajoene, since reduction by cysteine, which reacts with disulfide bonds, abolished its antimicrobial activity. PMID:8900018

Naganawa, R; Iwata, N; Ishikawa, K; Fukuda, H; Fujino, T; Suzuki, A

1996-11-01

128

Kinetics of aerobic oxidation of volatile sulfur compounds in wastewater and biofilm from sewers.  

PubMed

Laboratory experiments were conducted to investigate the kinetics of aerobic chemical and biological oxidation of selected odorous volatile sulfur compounds (VSCs) by wastewater and biofilm from sewers. The VSCs included methyl mercaptan (MeSH), ethyl mercaptan (EtSH), dimethyl sulfide (DMS) and total inorganic sulfide, which have all been reported as the main constituents of foul sewer gas. Samples of wastewater and biofilm for the experiments were obtained from two locations that differed significantly with respect to the occurrence of VSCs. One location represented an odor hot-spot downstream of a force main and the other was a gravity sewer transporting young aerobic wastewater. The kinetics of VSC oxidation for both wastewater and suspended biofilm samples followed a first-order rate equation. The average values of the reaction rate constants demonstrated the following order of reactivity: total inorganic sulfide > EtSH ? MeSH > DMS. Except for total inorganic sulfide oxidation in wastewater, kinetic parameters for each VSC were of similar magnitude for the two locations. In the wastewater from the odor hot-spot, sulfide inorganic oxidation rates were approximately 12 times faster than in the aerobic wastewater. PMID:24334879

Rudelle, E A; Vollertsen, J; Hvitved-Jacobsen, T; Nielsen, A H

2013-01-01

129

Isolation and characterization of a facultative methanotroph degrading malodor-causing volatile sulfur compounds.  

PubMed

Simultaneous removal of methane and malodor-causing volatile sulfur compounds (MVSCs), both emitted from landfills, is a desirable characteristic for methane-mitigation approaches. A methanotrophic bacterium was isolated from a microbial consortium, enriched with methane and dimethyl sulfide (DMS). It grew in the complex nutrient medium R2A without methane, and stably exhibited methanotrophic activity after facultative growth. It was identified as Sphingopyxis sp. MD2 by comparison of the 16S rRNA gene. It belongs to Sphingomonadales, whose members have not shown methanotrophic activity, phylogenetically distinct from orders of known methanotrophs. The MD2 biomass increased at a growth rate of 1.18d(-1) when methane was used as the sole growth substrate. An inhibition test with allylthiourea and PCR/sequencing confirmed the presence of particulate methane monooxygenase in MD2. DMS decreased the methane oxidation rate (2634±146 ?mole g DCW(-1) h(-1)) by 12%, while H(2)S had no effect on the methane oxidation rate. Interestingly, methanethiol (MT) enhanced the methane oxidation rate by more than 50%. MD2 degraded H(2)S and MT, regardless of the presence of methane. MD2 also degraded DMS in the presence of methane, indicating co-metabolism. These combined results indicate that MD2 may be a promising biological resource for simultaneous removal of methane and MVSCs. PMID:22884733

Lee, Jung-Hee; Kim, Tae Gwan; Cho, Kyung-Suk

2012-10-15

130

Reduced sulfur compounds in ambient air surrounding an industrial region in Korea.  

PubMed

The atmospheric concentrations of several reduced sulfur compounds (RSCs) including H(2)S, CH(3)SH, DMS, CS(2), and DMDS were measured concurrently from a series of field campaigns covering multiple locations in the surroundings of a large industrial region (August 2004 to September 2005). These field studies have been designed and undertaken to inspect the concentrations of RSCs in ambient air. The RSC concentrations were found to occur in a highly variable range. H(2)S (1.06 +/- 2.07 ppb) was found to be the most abundant RSC followed by CS(2) (0.84 +/- 0.54 ppb), DMDS (0.36 +/- 1.21 ppb), DMS (0.24 +/- 0.83 ppb), and CH(3)SH (0.11 +/- 0.23 ppb). The RSC levels measured at the study area were comparable to those observed previously from other polluted environmental settings. When these RSC data were examined further in terms of spatial (industrial vs. non-industrial sites) and seasonal (summer vs. winter seasons) grouping schemes, differences in their concentration levels were statistically insignificant in most cases. In contrast, there were fairly strong variations in temporal patterns over a diurnal cycle. If these RSC concentration data were converted to diagnose the malodor strengths, their effects were in most cases insignificant with minor contribution towards odor nuisances. PMID:18240003

Pal, Raktim; Kim, Ki-Hyun; Jeon, Eui-Chan; Song, Sang-Keun; Shon, Zang-Ho; Park, Shin-Young; Lee, Ki-Han; Hwang, Sun-Jin; Oh, Jong-Min; Koo, Youn-Seo

2009-01-01

131

Effects of Streptococcus thermophilus on volatile sulfur compounds produced by Porphyromonas gingivalis.  

PubMed

Halitosis as oral malodour is an unpleasant odour caused by volatile sulfur compounds (VSCs). VSCs are produced primarily by anaerobic bacteria that abundantly produce proteinase as trypsin-like enzyme. General therapies, such as mouthwash and plaque control, do not provide a continuous effect on oral halitosis. Streptococcus thermophilus is a probiotic bacterium that is beneficial for human health. The aim of this study was to evaluate the effect of S. thermophilus on Porphyromonas gingivalis-producing VSCs and to analyze the inhibitory mechanism of halitosis. P. gingivalis was cultured with or without S. thermophilus, and the emission of VSCs from the spent culture medium was measured by gas chromatography. In order to analyze the inhibitory effect, the antibacterial activity of S. thermophilus against P. gingivalis was assessed. After the spent culture medium or whole bacterial of S. thermophilus was mixed with the spent culture medium of P. gingivalis, VSCs were again measured by gas chromatograph. When S. thermophilus and P. gingivalis were co-cultivated, VSCs were present at a lower level than those of single-cultured P. gingivalis. S. thermophilus inhibited growth of P. gingivalis, and the whole bacteria and the spent culture medium of S. thermophilus reduced emission of VSCs gas. S. thermophilus may reduce oral malodour by inhibition of P. gingivalis growth and neutralizing VSCs with their metabolites or themselves. PMID:25105253

Lee, Sung-Hoon; Baek, Dong-Heon

2014-11-01

132

Measurements of Volatile Organic Compounds and Gaseous Sulfuric Acid During the 2008 CAREBEIJING Campaign  

NASA Astrophysics Data System (ADS)

Air quality in Beijing has been a hot topic recently, because Beijing hosted the 2008 summer Olympics. To combat the problem, China ordered numerous factories shut down or used only sporadically during the games to limit air pollution in the area. Another major step involved ordering about one-half of the city's 3.3 million vehicles off the road during the games, allowing only cars on roads with odd or even-numbered license plates on alternate days until the games were over. In addition, China has implemented new auto emission standards since March 2009 with regulations that are similar to those used throughout Europe. Our team at the Texas A&M participated in the 2008 CAREBEIJING campaign, with the objectives of studying the complex chemistry of the air in Beijing, looking at emission controls and their effectiveness, studying the surrounding air from other regions and how it can affect Beijing's air, and comparing all of our findings with air quality in other cities we have examined, such as Mexico City and Houston. In this talk, preliminary results of measurements of volatile organic compounds (VOCs) and gaseous sulfuric acid will be presented to discuss the trends of VOCs and new particle formation associated with the traffic control.

Zhang, R.; Zheng, J.; Hu, M.; Zhu, T.

2009-05-01

133

Multidimensional gas chromatography in combination with accurate mass, tandem mass spectrometry, and element-specific detection for identification of sulfur compounds in tobacco smoke.  

PubMed

A method is developed for identification of sulfur compounds in tobacco smoke extract. The method is based on large volume injection (LVI) of 10?L of tobacco smoke extract followed by selectable one-dimensional ((1)D) or two-dimensional ((2)D) gas chromatography (GC) coupled to a hybrid quadrupole time-of-flight mass spectrometer (Q-TOF-MS) using electron ionization (EI) and positive chemical ionization (PCI), with parallel sulfur chemiluminescence detection (SCD). In order to identify each individual sulfur compound, sequential heart-cuts of 28 sulfur fractions from (1)D GC to (2)D GC were performed with the three MS detection modes (SCD/EI-TOF-MS, SCD/PCI-TOF-MS, and SCD/PCI-Q-TOF-MS). Thirty sulfur compounds were positively identified by MS library search, linear retention indices (LRI), molecular mass determination using PCI accurate mass spectra, formula calculation using EI and PCI accurate mass spectra, and structure elucidation using collision activated dissociation (CAD) of the protonated molecule. Additionally, 11 molecular formulas were obtained for unknown sulfur compounds. The determined values of the identified and unknown sulfur compounds were in the range of 10-740ngmg total particulate matter (TPM) (RSD: 1.2-12%, n=3). PMID:25087743

Ochiai, Nobuo; Mitsui, Kazuhisa; Sasamoto, Kikuo; Yoshimura, Yuta; David, Frank; Sandra, Pat

2014-09-01

134

Methods for removing malodorous sulfur compounds from pulp mill flue gases and the like by using green liquor  

SciTech Connect

This is an improved method for removing malodorous sulfur compounds from flue gases generated in kraft or sodium sulfite pulping operations and the like by the absorption process using green liquor, an aqueous solution containing sodium sulfide and sodium carbonate. The malodorous gas compounds, including hydrogen sulfide, methyl mercaptan, and dimethyl sulfide are preferentially absorbed by the sodium sulfide forming sodium hydrosulfide and methanol. Any sulfur dioxide in the gas is absorbed and neutralized by sodium carbonate. In this method carbon dioxide absorption is minimized and the formation of sodium bicarbonate is limited. Sodium bicarbonate formation is minimized in order to avoid its reaction with sodium hydrosulfide which would then release undesirable hydrogen sulfide during absorption, as well as to forestall the need to increase chemical and lime kiln capacity requirements when the green liquor returned to the kraft recovery process contains excess amounts of sodium bicarbonate.

Farin, W.G.

1984-02-14

135

Growth of sulfate-reducing bacteria and methanogenic archaea with methylated sulfur compounds: a commentary on the thermodynamic aspects.  

PubMed

Methylated sulfur compounds such as dimethylsulfoniopropionate, dimethylsulfide, methanethiol, and other methylated sulfur compounds can act as sources of carbon and energy for the growth under anoxic conditions of a number of sulfate-reducing bacteria and methanogenic archaea. We summarise the range of degradative reactions that do or might occur in such organisms, and present thermodynamic data for these processes. These data enable estimates of the feasibility of the reactions as growth-supporting systems, and of the possible maximum growth yields of the bacteria and archaea catalysing them. We compare our new estimates with the few data that are currently available from the literature, and show that some published growth-yield assessments need reevaluation. PMID:12560992

Scholten, Johannes C M; Murrell, J Colin; Kelly, Donovan P

2003-01-01

136

CONTROLLING SULFUR OXIDES  

EPA Science Inventory

This Research Summary describes EPA's program to develop new and improve existing technologies for sulfur oxides control. As we increasingly turn to coal as the primary utility and industrial fuel, while trying to deal with the problems of acid precipitation, visibility degradati...

137

Sulfur in basaltic magmas  

Microsoft Academic Search

The concentration of S in basaltic magmas at 1 atm pressure is strongly dependent on temperature, the fugacities of oxygen ( f O 2 ) and sulfur ( f S 2 ), and bulk composition. Microprobe analyses of total S in rapidly quenched, submarine basalt glasses, used in conjunction with wet chemical analyses of Fe 2 O 3 \\/ FeO

Paul Wallace; Ian S. E. Carmichael

1992-01-01

138

Sodium sulfur battery seal  

Microsoft Academic Search

This disclosure is directed to an improvement in a sodium sulfur battery construction in which a seal between various battery compartments is made by a structure in which a soft metal seal member is held in a sealing position by holding structure. A pressure applying structure is used to apply pressure on the soft metal seal member when it is

Mikkor; Mati

1981-01-01

139

Sodium sulfur battery seal  

DOEpatents

This invention is directed to a seal for a sodium sulfur battery in which a flexible diaphragm sealing elements respectively engage opposite sides of a ceramic component of the battery which separates an anode compartment from a cathode compartment of the battery.

Topouzian, Armenag (Birmingham, MI)

1980-01-01

140

Sodium sulfur battery seal  

Microsoft Academic Search

This invention is directed to a seal for a sodium sulfur battery in which a flexible diaphragm sealing elements respectively engage opposite sides of a ceramic component of the battery which separates an anode compartment from a cathode compartment of the battery. 3 figs.

Topouzian

1980-01-01

141

COAL SULFUR MEASUREMENTS  

EPA Science Inventory

The report describes a new technique for sulfur forms analysis based on low-temperature oxygen plasma ashing. The technique involves analyzing the low-temperature plasma ash by modified ASTM techniques after selectively removing the organic material. The procedure has been tested...

142

SULFUR POLYMER ENCAPSULATION.  

SciTech Connect

Sulfur polymer cement (SPC) is a thermoplastic polymer consisting of 95 wt% elemental sulfur and 5 wt% organic modifiers to enhance long-term durability. SPC was originally developed by the U.S. Bureau of Mines as an alternative to hydraulic cement for construction applications. Previous attempts to use elemental sulfur as a construction material in the chemical industry failed due to premature degradation. These failures were caused by the internal stresses that result from changes in crystalline structure upon cooling of the material. By reacting elemental sulfur with organic polymers, the Bureau of Mines developed a product that successfully suppresses the solid phase transition and significantly improves the stability of the product. SPC, originally named modified sulfur cement, is produced from readily available, inexpensive waste sulfur derived from desulfurization of both flue gases and petroleum. The commercial production of SPC is licensed in the United States by Martin Resources (Odessa, Texas) and is marketed under the trade name Chement 2000. It is sold in granular form and is relatively inexpensive ({approx}$0.10 to 0.12/lb). Application of SPC for the treatment of radioactive, hazardous, and mixed wastes was initially developed and patented by Brookhaven National Laboratory (BNL) in the mid-1980s (Kalb and Colombo, 1985; Colombo et al., 1997). The process was subsequently investigated by the Commission of the European Communities (Van Dalen and Rijpkema, 1989), Idaho National Engineering Laboratory (Darnell, 1991), and Oak Ridge National Laboratory (Mattus and Mattus, 1994). SPC has been used primarily in microencapsulation applications but can also be used for macroencapsulation of waste. SPC microencapsulation has been demonstrated to be an effective treatment for a wide variety of wastes, including incinerator hearth and fly ash; aqueous concentrates such as sulfates, borates, and chlorides; blowdown solutions; soils; and sludges. It is not recommended for treatment of wastes containing high concentrations of nitrates because of potentially dangerous reactions between sulfur, nitrate, and trace quantities of organics. Recently, the process has been adapted for the treatment of liquid elemental mercury and mercury contaminated soil and debris.

KALB, P.

2001-08-22

143

Activity of vanadium catalysts for sulfuric acid production, promoted with Na, K, Rb, Cs, and Mg compounds, at various pressures of sulfur oxides  

Microsoft Academic Search

The activities of vanadium catalysts promoted with Na, K, Rb, Cs, and Mg sulfates (ratio Me:V = 4) were studied in conditions of low (up to 1 kPa) and high (up to 70 kPa) partial pressures of sulfur oxides at 693 and 758 K. The authors report results of reaction kinetic studies.

S. V. Ivanenko; R. R. Dzhoraev

1995-01-01

144

Control of the chemical state change of sulfur in solid compound targets during high-resolution PIXE measurements  

NASA Astrophysics Data System (ADS)

A high-energy-resolution wavelength-dispersive (WD) X-ray spectrometer in the Johansson geometry, which allowed energy resolution below the natural linewidth of the K ? lines was employed in measurements of the proton-induced K ? X-ray emission spectra for six typical sulfur compounds (CdS, Na2SO3, Na2 S2O5, NaHSO3, (NH4)2SO4, and Na2SO4) to investigate the chemical state change during 2.4-MeV proton irradiation with a current density of 7.5 nA/mm2. We found that the chemical state change of each compound depended on the various factors affecting the surface temperature increase, such as target thickness, mounting method, and existence of active cooling during the measurement. The chemical state of sulfur on the target surface of S4+ compounds was gradually changed into S6+ without exception through irradiation under poor cooling conditions. Sulfur compounds of the S0 and S6+ states with closed shell structures were proven to be chemically stable against proton bombardment, as expected. However, (NH4)2SO4 was found to be most sensitive to proton irradiation among the sulfur compounds, and S0, one of the reaction products, became a major element at doses higher than 3 × 108 Gy. If thick targets were mounted by using a carbon adhesive tape, chemical state change could be observed in some cases even with lowtemperature cooling down to -80 °C, however, the chemical state change seemed to be remarkably suppressed by using very thin targets mounted with a silver paste even without active cooling. In conclusion, the chemical states of sulfur compounds could be preserved without significant change for an accumulated dose of about 3 × 107 Gy, equivalent to a typical high-resolution PIXE scanning period, by adopting a proper target preparation scheme to discharge proton-induced thermal energy effectively from the irradiated target surface.

Woo, Hyung-Joo; Choi, Han-Woo; Kim, Gi-Dong; Kim, Joon-Kon

2012-07-01

145

Complete genome sequence of Desulfocapsa sulfexigens, a marine deltaproteobacterium specialized in disproportionating inorganic sulfur compounds  

PubMed Central

Desulfocapsa sulfexigens SB164P1 (DSM 10523) belongs to the deltaproteobacterial family Desulfobulbaceae and is one of two validly described members of its genus. This strain was selected for genome sequencing, because it is the first marine bacterium reported to thrive on the disproportionation of elemental sulfur, a process with a unresolved enzymatic pathway in which elemental sulfur serves both as electron donor and electron acceptor. Furthermore, in contrast to its phylogenetically closest relatives, which are dissimilatory sulfate-reducers, D. sulfexigens is unable to grow by sulfate reduction and appears metabolically specialized in growing by disproportionating elemental sulfur, sulfite or thiosulfate with CO2 as the sole carbon source. The genome of D. sulfexigens contains the set of genes that is required for nitrogen fixation. In an acetylene assay it could be shown that the strain reduces acetylene to ethylene, which is indicative for N-fixation. The circular chromosome of D. sulfexigens SB164P1 comprises 3,986,761 bp and harbors 3,551 protein-coding genes of which 78% have a predicted function based on auto-annotation. The chromosome furthermore encodes 46 tRNA genes and 3 rRNA operons. PMID:23961312

Finster, Kai Waldemar; Kjeldsen, Kasper Urup; Kube, Michael; Reinhardt, Richard; Mussmann, Marc; Amann, Rudolf; Schreiber, Lars

2013-01-01

146

Stability of volatile sulfur compounds (VSCs) in sampling bags - impact of temperature.  

PubMed

Volatile sulfur compounds (VSCs) are a major component of odorous emissions that can cause annoyance to local populations surrounding wastewater, waste management and agricultural practices. Odour collection and storage using sample bags can result in VSC losses due to sorption and leakage. Stability within 72 hour storage of VSC samples in three sampling bag materials (Tedlar, Mylar, Nalophan) was studied at three temperatures: 5, 20, and 30 °C. The VSC samples consisted of hydrogen sulfide (H2S), methanethiol (MeSH), ethanethiol (EtSH), dimethyl sulfide (DMS), tert-butanethiol (t-BuSH), ethylmethyl sulfide (EMS), 1-butanethiol (1-BuSH), dimethyl disulfide (DMDS), diethyl disulfide (DEDS), and dimethyl trisulfide (DMTS). The results for H2S showed that higher loss trend was clearly observed (46-50% at 24 hours) at 30 °C compared to the loss at 5 °C or 20 °C (of up to 27% at 24 hours) in all three bag materials. The same phenomenon was obtained for other thiols with the relative recoveries after a 24 hour period of 76-78% at 30 °C and 80-93% at 5 and 20 °C for MeSH; 77-80% at 30 °C and 79-95% at 5 and 20 °C for EtSH; 87-89% at 30 °C and 82-98% at 5 and 20 °C for t-BuSH; 61-73% at 30 °C and 76-98% at 5 and 20 °C for 1-BuSH. Results for other sulfides and disulfides (DMS, EMS, DMDS, DEDS) indicated stable relative recoveries with little dependency on temperature (83-103% after 24 hours). DMTS had clear loss trends (with relative recoveries of 74-87% in the three bag types after 24 hours) but showed minor differences in relative recoveries at 5, 20, and 30 °C. PMID:24185074

Le, H; Sivret, E C; Parcsi, G; Stuetz, R M

2013-01-01

147

Reduced sulfur compounds in gas from construction and demolition debris landfills.  

PubMed

The biological conversion of sulfate from disposed gypsum drywall to hydrogen sulfide (H(2)S) in the anaerobic environment of a landfill results in odor problems and possible health concerns at many disposal facilities. To examine the extent and magnitude of such emissions, landfill gas samples from wells, soil vapor samples from the interface of the waste and cover soil, and ambient air samples, were collected from 10 construction and demolition (C&D) debris landfills in Florida and analyzed for H(2)S and other reduced sulfur compounds (RSC). H(2)S was detected in the well gas and soil vapor at all 10 sites. The concentrations in the ambient air above the surface of the landfill were much lower than those observed in the soil vapor, and no direct correlation was observed between the two sampling locations. Methyl mercaptan and carbonyl sulfide were the most frequently observed other RSC, though they occurred at smaller concentrations than H(2)S. This research confirmed the presence of H(2)S at C&D debris landfills. High concentrations of H(2)S may be a concern for employees working on the landfill site. These results indicate that workers should use proper personal protection at C&D debris landfills when involved in excavation, landfill gas collection, or confined spaces. The results indicate that H(2)S is sufficiently diluted in the atmosphere to not commonly pose acute health impacts for these landfill workers in normal working conditions. H(2)S concentrations were extremely variable with measurements occurring over a very large range (from less than 3 ppbv to 12,000 ppmv in the soil vapor and from less than 3 ppbv to 50 ppmv in ambient air). Possible reasons for the large intra- and inter-site variability observed include waste and soil heterogeneities, impact of weather conditions, and different site management practices. PMID:16403620

Lee, Sue; Xu, Qiyong; Booth, Matthew; Townsend, Timothy G; Chadik, Paul; Bitton, Gabriel

2006-01-01

148

Effect of green tea on volatile sulfur compounds in mouth air.  

PubMed

Many food products are claimed to be effective in controlling halitosis. Halitosis is caused mainly by volatile sulfur compounds (VSCs) such as H(2)S and CH(3)SH produced in the oral cavity. Oral microorganisms degrade proteinaceous substrates to cysteine and methionine, which are then converted to VSCs. Most treatments for halitosis focus on controlling the number of microorganisms in the oral cavity. Since tea polyphenols have been shown to have antimicrobial and deodorant effects, we have investigated whether green tea powder reduces VSCs in mouth air, and compared its effectiveness with that of other foods which are claimed to control halitosis. Immediately after administering the products, green tea showed the largest reduction in concentration of both H(2)S and CH(3)SH gases, especially CH(3)SH which also demonstrated a better correlation with odor strength than H(2)S; however, no reduction was observed at 1, 2 and 3 h after administration. Chewing gum, mints and parsley-seed oil product did not reduce the concentration of VSCs in mouth air at any time. Toothpaste, mints and green tea strongly inhibited VSCs production in a saliva-putrefaction system, but chewing gum and parsley-seed oil product could not inhibit saliva putrefaction. Toothpaste and green tea also demonstrated strong deodorant activities in vitro, but no significant deodorant activity of mints, chewing gum or parsley-seed oil product were observed. We concluded that green tea was very effective in reducing oral malodor temporarily because of its disinfectant and deodorant activities, whereas other foods were not effective. PMID:18388413

Lodhia, Parth; Yaegaki, Ken; Khakbaznejad, Ali; Imai, Toshio; Sato, Tsutomu; Tanaka, Tomoko; Murata, Takatoshi; Kamoda, Takeshi

2008-02-01

149

Sulfur plumes off Namibia  

NASA Technical Reports Server (NTRS)

Sulfur plumes rising up from the bottom of the ocean floor produce colorful swirls in the waters off the coast of Namibia in southern Africa. The plumes come from the breakdown of marine plant matter by anaerobic bacteria that do not need oxygen to live. This image was acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra satellite on April 24, 2002 Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

2002-01-01

150

Sulfur mobility in peat  

Microsoft Academic Search

Lead-210 chronologies, vertical S concentration gradients and ?34S values are presented for 5 Sphagnum-dominated peat bogs located in Central Europe (Rybarenska slat and Ocean Bog; Czech Republic) and the British Isles (Thorne Moors, England; Connemara, Ireland; and Mull, Scotland). Sulfur concentrations were measured in three 40-cm deep peat cores per site, sectioned into 2-cm segments. The coefficient of variation in

Martin Novák; Marie Adamová; R. Kelman Wieder; Simon H. Bottrell

2005-01-01

151

Acidithiobacillus caldus Sulfur Oxidation Model Based on Transcriptome Analysis between the Wild Type and Sulfur Oxygenase Reductase Defective Mutant  

PubMed Central

Background Acidithiobacillus caldus (A. caldus) is widely used in bio-leaching. It gains energy and electrons from oxidation of elemental sulfur and reduced inorganic sulfur compounds (RISCs) for carbon dioxide fixation and growth. Genomic analyses suggest that its sulfur oxidation system involves a truncated sulfur oxidation (Sox) system (omitting SoxCD), non-Sox sulfur oxidation system similar to the sulfur oxidation in A. ferrooxidans, and sulfur oxygenase reductase (SOR). The complexity of the sulfur oxidation system of A. caldus generates a big obstacle on the research of its sulfur oxidation mechanism. However, the development of genetic manipulation method for A. caldus in recent years provides powerful tools for constructing genetic mutants to study the sulfur oxidation system. Results An A. caldus mutant lacking the sulfur oxygenase reductase gene (sor) was created and its growth abilities were measured in media using elemental sulfur (S0) and tetrathionate (K2S4O6) as the substrates, respectively. Then, comparative transcriptome analysis (microarrays and real-time quantitative PCR) of the wild type and the ?sor mutant in S0 and K2S4O6 media were employed to detect the differentially expressed genes involved in sulfur oxidation. SOR was concluded to oxidize the cytoplasmic elemental sulfur, but could not couple the sulfur oxidation with the electron transfer chain or substrate-level phosphorylation. Other elemental sulfur oxidation pathways including sulfur diooxygenase (SDO) and heterodisulfide reductase (HDR), the truncated Sox pathway, and the S4I pathway for hydrolysis of tetrathionate and oxidation of thiosulfate in A. caldus are proposed according to expression patterns of sulfur oxidation genes and growth abilities of the wild type and the mutant in different substrates media. Conclusion An integrated sulfur oxidation model with various sulfur oxidation pathways of A. caldus is proposed and the features of this model are summarized. PMID:22984393

Chen, Linxu; Ren, Yilin; Lin, Jianqun; Liu, Xiangmei; Pang, Xin; Lin, Jianqiang

2012-01-01

152

Advanced Sulfur Control Processing  

SciTech Connect

The primary objective of this project is to determine the feasibility of an alternate concept for the regeneration of high temperature desulfurization sorbents in which elemental sulfur, instead of SO{sub 2}, is produced. If successful, this concept will eliminate or alleviate problems caused by the highly exothermic nature of the regeneration reaction, the tendency for metal sulfate formation, and the need to treat the regeneration off-gas to prevent atmospheric SO{sub 2}, emissions. Iron and cerium-based sorbents were chosen on the basis of thermodynamic analysis to determine the feasibility of elemental sulfur production. The ability of both to remove H{sub 2}S during the sulfidation phase is less than that of zinc-based sorbents, and a two-stage desulfurization process will likely be required. Preliminary experimental work used electrobalance reactors to compare the relative rates of reaction of O{sub 2} and H{sub 2}O with FeS. More detailed studies of the regeneration of FeS as well as the sulfidation of CeO{sub 2} and regeneration of Ce{sub 2}O{sub 2}S are being carried out in a laboratory-scale fixed-bed reactor equipped with a unique analytical system which permits semi-continuous analysis of the distribution of elemental sulfur, H{sub 2}S, and SO{sub 2} in the reaction product gas.

Gangwal, S.K.; Portzer, J.W.; Turk, B.S.; Gupta, R. [Research Triangle Inst., Research Triangle Park, NC (United States)

1996-12-31

153

Expression and functional roles of Bradyrhizobium japonicum genes involved in the utilization of inorganic and organic sulfur compounds in free-living and symbiotic conditions.  

PubMed

Strains of Bradyrhizobium spp. form nitrogen-fixing symbioses with many legumes, including soybean. Although inorganic sulfur is preferred by bacteria in laboratory conditions, sulfur in agricultural soil is mainly present as sulfonates and sulfur esters. Here, we show that Bradyrhizobium japonicum and B. elkanii strains were able to utilize sulfate, cysteine, sulfonates, and sulfur-ester compounds as sole sulfur sources for growth. Expression and functional analysis revealed that two sets of gene clusters (bll6449 to bll6455 or bll7007 to bll7011) are important for utilization of sulfonates sulfur source. The bll6451 or bll7010 genes are also expressed in the symbiotic nodules. However, B. japonicum mutants defective in either of the sulfonate utilization operons were not affected for symbiosis with soybean, indicating the functional redundancy or availability of other sulfur sources in planta. In accordance, B. japonicum bacteroids possessed significant sulfatase activity. These results indicate that strains of Bradyrhizobium spp. likely use organosulfur compounds for growth and survival in soils, as well as for legume nodulation and nitrogen fixation. PMID:21190435

Sugawara, Masayuki; Shah, Gopit R; Sadowsky, Michael J; Paliy, Oleg; Speck, Justin; Vail, Andrew W; Gyaneshwar, Prasad

2011-04-01

154

3-(allyltrisulfanyl)-2-aminopropanoic acid, a novel nonvolatile water-soluble antimicrobial sulfur compound in heated garlic.  

PubMed

A nonvolatile and slightly water-soluble antimicrobial sulfur compound newly isolated from heated garlic extract was characterized. The compound was generated most when heated at 120°C for 30 minutes and completely disappeared after 90 minutes of heating. It has a molecular mass of 225 daltons with an elemental ratio of C?H??N?O?S?, and the interpretation of ¹H- and ¹³C-nuclear magnetic resonance and Fourier transform-infrared data showed that the compound was CH?=CH-CH?-S-S-S-CH?-CH(NH?)COOH, 3-(allyltrisulfanyl)-2-aminopropanoic acid, a derivative of cysteine, presumably derived from alliin (S-allyl-L-cysteine sulfoxide). This novel compound has comparatively potent anti-yeast activity and rather weak antibacterial activity, similar to other antimicrobial compounds in garlic. PMID:20828317

Kang, Seung-Sik; Lim, Dong Ryul; Kyung, Kyu Hang

2010-10-01

155

Understanding Sulfur Systematics in Large Igneous Provinces Using Sulfur Isotopes  

NASA Astrophysics Data System (ADS)

The eruption of the Siberian Traps coincided with perhaps the greatest environmental catastrophe in Earth's history, at the Permo-Triassic boundary. The source and magnitude of the volatile emissions, including sulfur, associated with the eruption remain poorly understood yet were critical in forcing environmental change. Two of the primary questions are how much sulfur gases were emitted during the eruptions and from where they were sourced. Primary melts carry dissolved sulfur from the mantle. Magmas ponding in sills and ascending through dykes may also assimilate sulfur from country rocks, as well as heat the country rocks and generate fluids through contact metamorphism. If the magmas interacted thermally, for prolonged periods, with sulfur-rich country rocks then it is probable that the sulfur budget of these eruptions might have been augmented considerably. This is exactly what we have shown recently for a basaltic sill emplaced in oil shale that fed eruptions of the British Tertiary Province, where surrounding sediments showed extensive desulfurization (Yallup et al. Geoch. Cosmochim. Acta, online, 2013). In the current study sulfur isotopes and trace element abundances are used to discriminate sulfur sources and to model magmatic processes for a suite of Siberian Traps sill and lava samples. Our bulk rock and pyrite geochemical analyses illustrate clearly their high abundance of 34S over 32S. The high 34S/32S has been noted previously and linked to assimilation of sulfur from sediments but may alternatively be inherited from the mantle plume source. With the aim of investigating the sulfur isotopic signature in the melt prior to devolatilization, we use secondary ion mass spectrometry (SIMS), for which a specific set of glass standards was synthesised. In order to understand how sulfur isotopes fractionate during degassing we have also conducted a parallel study of well-characterized tephras from Kilauea Volcano, where sulfur degassing behavior is well known.

Novikova, S.; Edmonds, M.; Turchyn, A. V.; Maclennan, J.; Svensen, H.; Frost, D. J.; Yallup, C.

2013-12-01

156

Catalyst for the reduction of sulfur dioxide to elemental sulfur  

DOEpatents

The inventive catalysts allow for the reduction of sulfur dioxide to elemental sulfur in smokestack scrubber environments. The catalysts have a very high sulfur yield of over 90% and space velocity of 10,000 h{sup {minus}1}. They also have the capacity to convert waste gases generated during the initial conversion into elemental sulfur. The catalysts have inexpensive components, and are inexpensive to produce. The net impact of the invention is to make this technology practically available to industrial applications. 21 figs.

Jin, Y.; Yu, Q.; Chang, S.G.

1996-02-27

157

Short-term distributions of reduced sulfur compounds in the ambient air surrounding a large landfill facility.  

PubMed

In order to explore the environmental behavior of reduced sulfur compounds (RSC) as malodorous components emitted from diverse source processes, the distribution characteristics of four sulfur (S) compounds - hydrogen sulfide (H2S), methyl mercaptan (CH3SH), dimethyl sulfide (DMS: (CH3)2S), and dimethyl disulfide (DMDS: (CH3)2S2) - were investigated in a municipal landfill area. In the course of this study, their ambient concentration levels were measured during two time periods from 13 individual spots selected as a function of distance from the center of the landfill site. The results generally indicated the absolute dominance of H2S over the other S compounds investigated (up to 5 km radius) such that their mean values were found as 1415 (H2S), 148 (DMS), 20.6 (CH3SH), and 14.4 ppt (DMDS). When our data were compared in terms of either varying distance from the source or relationship with meteorological conditions, the H2S data sets were most evident to reflect the potential effects of strong source processes in the landfill environment, relative to other S gases (or to volatile organic compounds measured concurrently). The results of this study further indicated the relatively good correspondence between the measured H2S concentration level and humans' intuitive sensory of odor and nuisance. PMID:16738778

Kim, K-H; Choi, Y-J; Oh, S-I; Sa, J H; Jeon, E-C; Koo, Y S

2006-10-01

158

Phanerozoic cycles of sedimentary carbon and sulfur  

PubMed Central

A reservoir model of a Recent steady-state sedimentary system in which the reduced sulfur and oxidized sulfur reservoirs were coupled with the oxidized carbon and reduced carbon reservoirs was constructed. The time curve of the sulfur isotope ratios of the sedimentary sulfate reservoir was used to drive the model back to the beginning of Cambrian time (600 million years ago), producing the reservoir sizes and isotope values and material fluxes of the carbon-sulfur system. The predicted values of carbon isotope ratios of the carbonate reservoir agree well with observed values, showing that the model is basically sound. Some general conclusions from this success are (i) material flux rates in the carbon-oxygen-sulfur system of the geologic past (averaged over tens of millions of years) lie within about a factor of 2 of Recent rates. (ii) The oxidation-reduction balances of Phanerozoic time were dominated by reciprocal relationships between carbon and sulfur compounds. (iii) The rate of production of atmospheric oxygen by storage in sediments of organic carbon of photosynthetic origin increased from the Cambrian Period to the Permian Period and declined somewhat from the Permian Period to the Present. (iv) The storage of oxygen in oxidized sulfur compounds kept pace (within the limits of the data) with oxygen production. (v) Transfer of oxygen from CO2 to SO4 from the Cambrian to the Permian Period was several times the Recent free oxygen content of the atmosphere. PMID:16593066

Garrels, Robert M.; Lerman, Abraham

1981-01-01

159

[Sulfur metabolism and its regulation in plants].  

PubMed

Sulfur, one of the vital macroelements, is present in nature in several redox forms (S(+VI), S(+IV), S(+II), S0). In most organic compounds sulfur is present in the reduced form (S(-II)), while most inorganic sulfur is oxidized, in a form of sulfate (S(+VI)). Animals and humans can incorporate only the organic forms of sulfur, present in sulfur-containing amino acids. Plants, most bacteria and fungi are able to uptake inorganic sulfate, gradually reduce it and assimilate it into variety of organic compounds. Knowledge of the regulatory mechanisms of this process is a key factor for understanding relationships between availability of sulfur source and plant growth and development, their resistance to environmental stresses and nutritional value of edible crops. Recently, a number of research groups conducted intensive investigations on sulfur metabolism and its regulation in plants. The aim of this review is to inform the Polish reader about the new results and concepts in this field. PMID:19248587

Moniuszko, Grzegorz; Sirko, Agnieszka

2008-01-01

160

Influence of Sulfur for Oxygen Substitution in the Solvolytic Reactions of Chloroformate Esters and Related Compounds  

PubMed Central

The replacement of oxygen within a chloroformate ester (ROCOCl) by sulfur can lead to a chlorothioformate (RSCOCl), a chlorothionoformate (ROCSCl), or a chlorodithioformate (RSCSCl). Phenyl chloroformate (PhOCOCl) reacts over the full range of solvents usually included in Grunwald-Winstein equation studies of solvolysis by an addition-elimination (A-E) pathway. At the other extreme, phenyl chlorodithioformate (PhSCSCl) reacts across the range by an ionization pathway. The phenyl chlorothioformate (PhSCOCl) and phenyl chlorothionoformate (PhOCSCl) react at remarkably similar rates in a given solvent and there is a dichotomy of behavior with the A-E pathway favored in solvents such as ethanol-water and the ionization mechanism favored in aqueous solvents rich in fluoroalcohol. Alkyl esters behave similarly but with increased tendency to ionization as the alkyl group goes from 1° to 2° to 3°. N,N-Disubstituted carbamoyl halides favor the ionization pathway as do also the considerably faster reacting thiocarbamoyl chlorides. The tendency towards ionization increases as, within the three contributing structures of the resonance hybrid for the formed cation, the atoms carrying positive charge (other than the central carbon) change from oxygen to sulfur to nitrogen, consistent with the relative stabilities of species with positive charge on these atoms. PMID:25310653

D’Souza, Malcolm J.; Kevill, Dennis N.

2014-01-01

161

Influence of sulfur for oxygen substitution in the solvolytic reactions of chloroformate esters and related compounds.  

PubMed

The replacement of oxygen within a chloroformate ester (ROCOCl) by sulfur can lead to a chlorothioformate (RSCOCl), a chlorothionoformate (ROCSCl), or a chlorodithioformate (RSCSCl). Phenyl chloroformate (PhOCOCl) reacts over the full range of solvents usually included in Grunwald-Winstein equation studies of solvolysis by an addition-elimination (A-E) pathway. At the other extreme, phenyl chlorodithioformate (PhSCSCl) reacts across the range by an ionization pathway. The phenyl chlorothioformate (PhSCOCl) and phenyl chlorothionoformate (PhOCSCl) react at remarkably similar rates in a given solvent and there is a dichotomy of behavior with the A-E pathway favored in solvents such as ethanol-water and the ionization mechanism favored in aqueous solvents rich in fluoroalcohol. Alkyl esters behave similarly but with increased tendency to ionization as the alkyl group goes from 1° to 2° to 3°. N,N-Disubstituted carbamoyl halides favor the ionization pathway as do also the considerably faster reacting thiocarbamoyl chlorides. The tendency towards ionization increases as, within the three contributing structures of the resonance hybrid for the formed cation, the atoms carrying positive charge (other than the central carbon) change from oxygen to sulfur to nitrogen, consistent with the relative stabilities of species with positive charge on these atoms. PMID:25310653

D'Souza, Malcolm J; Kevill, Dennis N

2014-01-01

162

40 CFR 50.5 - National secondary ambient air quality standard for sulfur oxides (sulfur dioxide).  

Code of Federal Regulations, 2010 CFR

...National secondary ambient air quality standard for sulfur oxides (sulfur dioxide...PRIMARY AND SECONDARY AMBIENT AIR QUALITY STANDARDS § 50.5 National secondary ambient air quality standard for sulfur oxides (sulfur...

2010-07-01

163

40 CFR 50.5 - National secondary ambient air quality standard for sulfur oxides (sulfur dioxide).  

Code of Federal Regulations, 2011 CFR

...National secondary ambient air quality standard for sulfur oxides (sulfur dioxide...PRIMARY AND SECONDARY AMBIENT AIR QUALITY STANDARDS § 50.5 National secondary ambient air quality standard for sulfur oxides (sulfur...

2011-07-01

164

40 CFR 50.17 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).  

Code of Federal Regulations, 2011 CFR

...National primary ambient air quality standards for sulfur oxides (sulfur dioxide...PRIMARY AND SECONDARY AMBIENT AIR QUALITY STANDARDS § 50.17 National primary ambient air quality standards for sulfur oxides (sulfur...

2011-07-01

165

Current emission trends for nitrogen oxides, sulfur dioxide, and volatile organic compounds by month and state: Methodology and results  

SciTech Connect

This report presents estimates of monthly sulfur dioxide (SO{sub 2}), nitrogen oxides (NO{sub x}), and nonmethane voltatile organic compound (VOC) emissions by sector, region, and state in the contiguous United States for the years 1975 through 1988. This work has been funded as part of the National Acid Precipitation Assessment Program's Emissions and Controls Task Group by the US Department of Energy (DOE) Office of Fossil Energy (FE). The DOE project officer is Edward C. Trexler, DOE/FE Office of Planning and Environment.

Kohout, E.J.; Miller, D.J.; Nieves, L.A.; Rothman, D.S.; Saricks, C.L.; Stodolsky, F.; Hanson, D.A.

1990-08-01

166

Current emission trends for nitrogen oxides, sulfur dioxide, and volatile organic compounds by month and state: Methodology and results  

SciTech Connect

This report presents estimates of monthly sulfur dioxide (SO{sub 2}), nitrogen oxides (NO{sub x}), and nonmethane voltatile organic compound (VOC) emissions by sector, region, and state in the contiguous United States for the years 1975 through 1988. This work has been funded as part of the National Acid Precipitation Assessment Program`s Emissions and Controls Task Group by the US Department of Energy (DOE) Office of Fossil Energy (FE). The DOE project officer is Edward C. Trexler, DOE/FE Office of Planning and Environment.

Kohout, E.J.; Miller, D.J.; Nieves, L.A.; Rothman, D.S.; Saricks, C.L.; Stodolsky, F.; Hanson, D.A.

1990-08-01

167

Elemental sulfur in the gills of three species of clams containing chemoautotrophic symbiotic bacteria: a possible inorganic energy storage compound  

Microsoft Academic Search

Sulfur content and fine structure were studied for tissues of three species of clams, Lucinoma annulata, Calyptogena elongata and Lucina floridana, which inhabit sulfide-rich environments and whose gills harbor symbiotic sulfur bacteria. Lucinoma annulata and C. elongata were dredged from the Santa Barbara basin, California, USA, at a depth of 480 to 490 m, and Lucina floridana were dug from

R. D. Vetter

1985-01-01

168

Characterization of sulfur compounds in whisky by full evaporation dynamic headspace and selectable one-dimensional/two-dimensional retention time locked gas chromatography-mass spectrometry with simultaneous element-specific detection.  

PubMed

A method is described for characterization of sulfur compounds in unaged and aged whisky. The method is based on full evaporation dynamic headspace (FEDHS) of 100 ?L of whisky samples followed by selectable one-dimensional ((1)D) or two-dimensional ((2)D) retention-time-locked (RTL) gas chromatography (GC)-mass spectrometry (MS) with simultaneous element-specific detection using a sulfur chemiluminescence detector (SCD) and a nitrogen chemiluminescence detector (NCD). Sequential heart-cuts of the 16 sulfur fractions were used to identify each individual sulfur compound in the unaged whisky. Twenty sulfur compounds were positively identified by a MS library search, linear retention indices (LRI), and formula identification using MS calibration software. Additionally eight formulas were also identified for unknown sulfur compounds. Simultaneous heart-cuts of the 16 sulfur fractions were used to produce the (2)D RTL GC-SCD chromatograms for principal component analysis. PCA of the (2)D RTL GC-SCD data clearly demonstrated the difference between unaged and aged whisky, as well as two different whisky samples. Fourteen sulfur compounds could be characterized as key sulfur compounds responsible for the changes in the aging step and/or the difference between two kinds of whisky samples. The determined values of the key sulfur compounds were in the range of 0.3-210 ng mL(-1) (RSD: 0.37-12%, n=3). PMID:23182286

Ochiai, Nobuo; Sasamoto, Kikuo; MacNamara, Kevin

2012-12-28

169

Process for removing sulfur from sulfur-containing gases  

DOEpatents

The present disclosure relates to improved processes for treating hot sulfur-containing flue gas to remove sulfur therefrom. Processes in accorda The government may own certain rights in the present invention pursuant to EPA Cooperative Agreement CR 81-1531.

Rochelle, Gary T. (Austin, TX); Jozewicz, Wojciech (Chapel Hill, NC)

1989-01-01

170

Evolution of Volatile Sulfur Compounds during Laboratory-Scale Incubations and Indoor Preparation of Compost Used as a Substrate in Mushroom Cultivation  

PubMed Central

Volatile sulfur compounds are known to be produced during the preparation of compost used as a substrate in mushroom cultivation. Because they cause odor problems, attempts have been made to reduce the production of these compounds. The influences of temperature and various additions on the production of volatile sulfur compounds from composting material were tested on laboratory-scale preparations. The production of H2S, COS, CH3SH, and (CH3)2S was proven to be a biological process with an optimal temperature that coincides with the optimal temperature for biological activity. The formation of CS2 and (CH3)2S2 was shown to be a nonbiological process. The emission of volatile sulfur compounds during the indoor preparation of mushroom compost appeared to be remarkably reduced (about 90%) as compared with the emission during the conventional outdoor process. Introduction of this indoor composting process would result in a significant reduction in environmental pollution. PMID:16348421

Derikx, P. J. L.; Simons, F. H. M.; Op den Camp, H. J. M.; van der Drift, C.; Van Griensven, L. J. L. D.; Vogels, G. D.

1991-01-01

171

8, 93479404, 2008 Sulfur isotope  

E-print Network

ACPD 8, 9347­9404, 2008 Sulfur isotope analyses of individual aerosol particles B. Winterholler et the Creative Commons Attribution 3.0 License. Atmospheric Chemistry and Physics Discussions Sulfur isotope isotope analyses of individual aerosol particles B. Winterholler et al. Title Page Abstract Introduction

Paris-Sud XI, Université de

172

Demonstrating Allotropic Modifications of Sulfur.  

ERIC Educational Resources Information Center

Shows how a common demonstration that consists of slowly heating sulfur powder in a test tube to illustrate sulfur's allotropic modifications can convince students of conclusions about the moon Io which they often find surprising. Describes the demonstration in full. (Author/MM)

McCarty, Jillian L.; Dragojlovic, Veljko

2002-01-01

173

Sulfur production continues to rise  

SciTech Connect

Sulfur is one of the world's most-popular commodities. It has another distinctive feature: most of it is produced from the effluent of chemical process plants. A lot more sulfur will have similar origins in the future as countries tighten up on sulfur emissions in a global effort to reduce acid rain. To meet such stricter controls, new sulfur recovery methods are being developed, and existing ones improved, to extract sulfur more efficiently and cheaply. Among the new developments are improvements in the Claus process--and alternatives to Claus--for the extraction of hydrogen sulfide (H[sub 2]S) from process streams; and new ways to recover elemental sulfur from sulfur dioxide (SO[sub 2]) contained in the flue gas of coal-fired plants. Currently, the common flue gas treatment is scrubbing with limestone or lime, but this produces millions of tons/yr of gypsum sludge that is mostly landfilled. Gypsum can be processed into wallboard, but that market is limited. The paper discusses the use of flue gas as a raw material; a versatile acid production process; alternative processes for H[sub 2]S extraction; and a process that recovers both sulfur and hydrogen.

Parkinson, G.; Ondrey, G.; Moore, S.

1994-06-01

174

SULFUR RETENTION IN COAL ASH  

EPA Science Inventory

The report gives results of an analytical study to assess the potential for sulfur retention in various types of coal-fired boilers. Results of a field test of 10 industrial coal-fired boilers were used to evaluate the impact on sulfur retention of the operating variables (load a...

175

Characterizing reduced sulfur compounds emissions from a swine concentrated animal feeding operation  

NASA Astrophysics Data System (ADS)

Reduced sulfur compounds (RSCs) emissions from concentrated animal feeding operations (CAFOs) have become a potential environmental and human health concern, as a result of changes in livestock production methods. RSC emissions were determined from a swine CAFO in North Carolina. RSC measurements were made over a period of ?1 week from both the barn and lagoon during each of the four seasonal periods from June 2007 to April 2008. During sampling, meteorological and other environmental parameters were measured continuously. Seasonal hydrogen sulfide (H2S) barn concentrations ranged from 72 to 631 ppb. Seasonal dimethyl sulfide (DMS; CH3SCH3) and dimethyl disulfide (DMDS; CH3S2CH3) concentrations were 2-3 orders of magnitude lower, ranging from 0.18 to 0.89 ppb and 0.47 to 1.02 ppb, respectively. The overall average barn emission rate was 3.3 g day-1 AU-1 (AU (animal unit) = 500 kg of live animal weight) for H2S, which was approximately two orders of magnitude higher than the DMS and DMDS overall average emissions rates, determined as 0.017 g day-1 AU-1 and 0.036 g day-1 AU-1, respectively. The overall average lagoon flux was 1.33 ?g m-2 min-1 for H2S, which was approximately an order of magnitude higher than the overall average DMS (0.12 ?g m-2 min-1) and DMDS (0.09 ?g m-2 min-1) lagoon fluxes. The overall average lagoon emission for H2S (0.038 g day-1 AU-1) was also approximately an order of magnitude higher than the overall average DMS (0.0034 g day-1 AU-1) and DMDS (0.0028 g day-1 AU-1) emissions. H2S, DMS and DMDS have offensive odors and low odor thresholds. Over all four sampling seasons, 77% of 15 min averaged H2S barn concentrations were an order of magnitude above the average odor threshold. During these sampling periods, however, DMS and DMDS concentrations did not exceed their odor thresholds. The overall average barn and lagoon emissions from this study were used to help estimate barn, lagoon and total (barn + lagoon) RSC emissions from swine CAFOs in North Carolina. Total (barn + lagoon) H2S emissions from swine CAFOs in North Carolina were estimated to be 1.22*106 kg yr-1. The barns had significantly higher H2S emissions than the lagoons, contributing ?98% of total North Carolina H2S swine CAFO emissions. Total (barn + lagoon) emissions for DMS and DMDS were 1-2 orders of magnitude lower, with barns contributing ?86% and ?93% of total emissions, respectively. H2S swine CAFO emissions were estimated to contribute ?18% of North Carolina H2S emissions.

Rumsey, Ian C.; Aneja, Viney P.; Lonneman, William A.

2014-09-01

176

Improve operations and enhance refinery sulfur recovery  

SciTech Connect

Sulfur is a common contaminant in fossil fuels, released when these fuels are combusted. It causes acid rain and other environmental problems. Sulfur emissions have gained worldwide attention, resulting in tighter requirements for sulfur recovery facilities. New technologies and enhancements to existing technologies have emerged as a result. This overview presents many technologies used for sulfur recovery. It is organized around the unit operations of gas and liquid sweetening, sour water stripping, sulfur recovery, sulfur degassing and solidification, tail gas treating, and incineration. New technical and equipment innovations have resulted in sulfur recovery facilities that are more reliable, recover more sulfur, are easier to operate, and reduce capital and operating costs.

Bourdon, J.C. [Black and Veatch Pritchard, Inc., Overland Park, KS (United States)

1997-04-01

177

Theoretical studies of the marine sulfur cycle  

NASA Technical Reports Server (NTRS)

Several reduced sulfur compounds are produced by marine organisms and then enter the atmosphere, where they are oxidized and ultimately returned to the ocean or the land. The oceanic dimethyl sulfide (DMS) flux, in particular, represents a significant fraction of the annual global sulfur input to the atmosphere. In the atmosphere, this gas is converted to sulfur dioxide (SO2), methane sulfonic acid, and other organic acids which are relatively stable and about which little is known. SO2 is a short lived gas which, in turn, is converted to sulfuric acid and other sulfate compounds which contribute significantly to acid rain. Because of the complexity of the sulfur system, it is not well understood even in the unperturbed atmosphere. However, a number of new observations and experiments have led to a significant increase in the understanding of this system. A number of one dimensional model experiments were conducted on the gas phase part of the marine sulfur cycle. The results indicate the measured concentration of DMS and the amplitude of its diurnal cycle are in agreement with estimates of its global flux. It was also found that DMS can make a large contribution to the background SO2 concentration in the free troposphere. Estimates of CS2 concentrations in the atmosphere are inconsistent with estimated fluxes; however, measured reaction rates are consistent with the observed steep tropospheric gradient in CS2. Observations of CS2 are extremely sparse. Further study is planned.

Toon, Owen B.; Kasting, James B.; Liu, May S.

1985-01-01

178

Post-SL9 Sulfur Photochemistry on Jupiter  

NASA Technical Reports Server (NTRS)

We have modeled the photochemical evolution of the sulfur containing species that were observed in Jupiter's stratosphere after the Shoemaker Levy 9 (SL9) impacts. We find that most of the sulfur is converted to S8 in the first few days. Other important sulfur reservoirs are CS, whose abundance increases markedly with time, and possibly H2CS, HNCS, and NS, whose abundances depend on kinetic reaction rates that are unknown at the present. We discuss the temporal variation of the major sulfur compounds, make abundance and compositional predictions useful for comparison with observations, and discuss the possible condensation of sulfur containing species.

Moses, Julianne I.; Allen, Mark; Gladstone, G. Randall

1995-01-01

179

Inhibition of Ammonia Oxidation in Nitrosomonas europaea by Sulfur Compounds: Thioethers Are Oxidized to Sulfoxides by Ammonia Monooxygenase  

PubMed Central

Organic sulfur compounds are well-known nitrification inhibitors. The inhibitory effects of dimethylsulfide, dimethyldisulfide, and ethanethiol on ammonia oxidation by Nitrosomonas europaea were examined. Both dimethylsulfide and dimethyldisulfide were weak inhibitors of ammonia oxidation and exhibited inhibitory characteristics typical of substrates for ammonia monooxygenase (AMO). Depletion of dimethylsulfide required O2 and was prevented with either acetylene or allylthiourea, two inhibitors of AMO. The inhibition of ammonia oxidation by dimethylsulfide was examined in detail. Cell suspensions incubated in the presence of ammonia oxidized dimethylsulfide to dimethyl sulfoxide. Depletion of six other thioethers was also prevented by treating cell suspensions with either allylthiourea or acetylene. The oxidative products of three thioethers were identified as the corresponding sulfoxides. The amount of sulfoxide formed accounted for a majority of the amount of sulfide depleted. By using gas chromatography coupled with mass spectrometry, allylmethylsulfide was shown to be oxidized to allylmethylsulfoxide by N. europaea with the incorporation of a single atom of 18O derived from 18O2 into the sulfide. This result supported our conclusion that a monooxygenase was involved in the oxidation of allylmethylsulfide. The thioethers are concluded to be a new class of substrates for AMO. This is the first report of the oxidation of the sulfur atom by AMO in whole cells of N. europaea. The ability of N. europaea to oxidize dimethylsulfide is not unique among the ammonia-oxidizing bacteria. Nitrosococcus oceanus, a marine nitrifier, was also demonstrated to oxidize dimethylsulfide to dimethyl sulfoxide. PMID:16349086

Juliette, Lisa Y.; Hyman, Michael R.; Arp, Daniel J.

1993-01-01

180

Instrumental methods of analysis of sulfur compounds in synfuel process streams. Quarterly technical progress report, October-December 1982  

SciTech Connect

The general objective is to develop dependable and accurate instrumental analysis methods for the determination of sulfur moieties. These will include polysulfides, dithionite and polythionates. Calorimetric procedures (thermometric titrations, injection enthalpimetry) and electroanalytical techniques (voltammetry, coulometric analysis, etc.) will be used. The complete speciation of sulfur will be undertaken in representative synfuel process stream samples. Total sulfidic sulfur has been quantitated with the aid of diffusion currents engendered by the anodic depolarization of the dropping mercury electrode. Classical chemical reactions involving polythionates were surveyed as to their applicability to analytical determinations by Direct Injection Enthalpimetry (DIE). Reactions included polythionate decomposition by sulfide precipitation with mercuric chloride, silver nitrate, and thallows nitrate; polythionate oxidation, cyanolysis, and complexation with aquopentaammine cobalt (+3) chloride. An analysis of two H-Coal sour water samples was undertaken using thermochemical, electrochemical and classical methods. The various methods yielded consistent sulfidic and polysulfidic sulfur levels. This internal consistency substantiated the accuracy of the findings.

Jordan, J.; Stahl, J.; Yakupkovic, J.

1983-01-01

181

The significance of glucosinolates for sulfur storage in Brassicaceae seedlings  

PubMed Central

Brassica juncea seedlings contained a twofold higher glucosinolate content than B. rapa and these secondary sulfur compounds accounted for up to 30% of the organic sulfur fraction. The glucosinolate content was not affected by H2S and SO2 exposure, demonstrating that these sulfur compounds did not form a sink for excessive atmospheric supplied sulfur. Upon sulfate deprivation, the foliarly absorbed H2S and SO2 replaced sulfate as the sulfur source for growth of B. juncea and B. rapa seedlings. The glucosinolate content was decreased in sulfate-deprived plants, though its proportion of organic sulfur fraction was higher than that of sulfate-sufficient plants, both in absence and presence of H2S and SO2. The significance of myrosinase in the in situ turnover in these secondary sulfur compounds needs to be questioned, since there was no direct co-regulation between the content of glucosinolates and the transcript level and activity of myrosinase. Evidently, glucosinolates cannot be considered as sulfur storage compounds upon exposure to excessive atmospheric sulfur and are unlikely to be involved in the re-distribution of sulfur in B. juncea and B. rapa seedlings upon sulfate deprivation. PMID:25566279

Aghajanzadeh, Tahereh; Hawkesford, Malcolm J.; De Kok, Luit J.

2014-01-01

182

Third quarterly technical summary report on the homogeneous production and removal of NO/sub x/ from combustion exhaust flows. [27 reactions of sulfur or sulfur compounds with other gases or vapors  

SciTech Connect

The addition of ammonia to the exhaust stream of stationary combustors is a promising approach toward reducing NO/sub x/ emissions. The use of high sulfur-content fuels will produce moderate quantities of SO/sub 2/ and other sulfur-bearing compounds which may affect the effectiveness of this thermal deNO/sub x/ process. Modeling efforts indicate that the presence of SO/sub 2/ is slightly beneficial in removing NO above 1250K. In addition, experiments show that the ammonia species (NH/sub i/, i = 1,2,3) have no appreciable reaction rate with SO/sub 2/. An explanation of the effect of SO/sub 2/ on the thermal deNO/sub x/ process is presented, as well as preliminary calculations leading to the measurement of the key reaction of H + SO/sub 3/.

Silver, J.A.

1981-05-01

183

Characterizing reduced sulfur compounds and non-methane volatile organic compounds emissions from a swine concentrated animal feeding operation  

NASA Astrophysics Data System (ADS)

Reduced sulfur compounds (RSCs) and non-methane volatile organic compounds (NMVOCs) emissions from concentrated animal feeding operations (CAFOs) have become a potential environmental and human health concern. Both RSCs and NMVOCs contribute to odor. In addition, RSCs also have the potential to form fine particulate matter (PMfine) and NMVOCs the potential to form ozone. Measurements of RSCs and NMVOCs emissions were made from both an anaerobic lagoon and barn at a swine CAFO in North Carolina. Emission measurements were made over all four seasonal periods. In each seasonal period, measurements were made from both the anaerobic lagoon and barn for ˜1 week. RSC and NMVOCs samples were collected using passivated canisters. Nine to eleven canister samples were taken from both the lagoon and barn over each sampling period. The canisters were analyzed ex-situ using gas chromatography flame ionization detection (GC-FID). Hydrogen sulfide (H2S) measurements were made in-situ using a pulsed fluorescence H2S/SO2 analyzer. During sampling, measurements of meteorological and physiochemical parameters were made. H2S had the largest RSC flux, with an overall average lagoon flux of 1.33 mug m-2 min-1. The two main RSCs identified by the GC-FID, dimethyl sulfide (DMS) and dimethyl disulfide (DMDS), had overall average lagoon fluxes an order of magnitude lower, 0.12 and 0.09 mug m-2 min-1, respectively. Twelve significant NMVOCs were identified in lagoon samples (ethanol, 2-ethyl-1-hexanol, methanol, acetaldehyde, decanal, heptanal, hexanal, nonanal, octanal, acetone, methyl ethyl ketone, and 4-methylphenol). The overall average fluxes for these NMVOCs, ranged from 0.08 mug m-2 min-1 (4-methylphenol) to 2.11 mug m-2 min-1 (acetone). Seasonal H2S barn concentrations ranged from 72-631 ppb. DMS and DMDS seasonal concentrations were 2-3 orders of magnitude lower. There were six significant NMVOCs identified in barn samples (methanol, ethanol, acetone 2-3 butanedione, acetaldehyde and 4-methylphenol). Their overall average NMVOCs concentrations ranged from 2.87 ppb (4-methylphenol) to 16.21 ppb (ethanol). The overall average barn normalized emissions were 3.3 g day-1 AU-1 (AU (animal unit) = 500 kg) for H2S, 0.018 g day-1 AU-1 for DMS and 0.037 g day -1 AU-1 for DMDS. Normalized overall average NMVOC emissions ranged from 0.45 g day-1 AU-1 for ethanol to 0.16 g day-1 AU-1 for acetaldehyde. Barn H2S concentrations were generally one to two orders of magnitude above their odor thresholds. DMDS concentrations also regularly exceeded the lower limit of an odor threshold. Four NMVOCs (2-3 butanedione, decanal, 4-methylphenol and nonanal) had barn concentrations exceeding an odor threshold. Using overall average lagoon and barn emissions, the emissions from swine CAFOs in North Carolina were estimated. H2S had the largest RSC emission with an estimated North Carolina emission of 1.46 million kg yr -1, which was ˜21% of total North Carolina H2S emissions. Ethanol was the NMVOC with the largest North Carolina emission with an emission of 206,367 kg yr-1.

Rumsey, Ian Cooper

184

Production of sulfur from sulfur dioxide obtained from flue gas  

SciTech Connect

This patent describes a regenerable process for recovery of elemental sulfur from a gas containing sulfur dioxide comprising the steps of: contacting the gas with an aqueous, alkaline reaction medium containing sodium sulfite in concentration sufficient so that a slurry containing solid sodium sulfide is formed to react sulfur dioxide with sodium sulfite to form a solution containing dissolved sodium pyrosulfite and sodium sulfite; separating sulfur dioxide from the solution produced to leave a residual mixture containing water, sodium sulfite and a sodium pyrosulfite, the amount of sulfur dioxide separated being equal to about one-third the amount of sulfur dioxide which reacted with sodium sulfite; adding, in substantial absence of air, sufficient water and sodium bicarbonate to the residual mixture to react with the dissolved sodium pyrsulfide and form a slurry of solid sodium sulfite suspended in the resulting aqueous, alkaline reaction medium and gaseous carbon dioxide; separating the gaseous carbon dioxide; separating the solid sodium sulfite from the aqueous alkaline reaction medium and recycling the separated reaction medium; reducing the separated sodium sulfite to sodium sulfide; adding the sodium sulfide to an aqueous reaction medium containing sodium bicarbonate and, in the substantial absence of air, carbonating the resulting mixture with the gaseous carbon dioxide to form a slurry of solid particles of sodium bicarbonate dispersed in an aqueous reactor medium containing sodium bicarbonate, along with a gas composed primarily of hydrogen sulfide.

Miller, R.

1989-06-06

185

The role of the sulfur globule proteins of Allochromatium vinosum : mutagenesis of the sulfur globule protein genes and expression studies by real-time RT-PCR  

Microsoft Academic Search

During oxidation of reduced sulfur compounds, the purple sulfur bacterium Allochromatium vinosum stores sulfur in the periplasm in the form of intracellular sulfur globules. The sulfur in the globules is enclosed by a protein envelope that consists of the homologous 10.5-kDa proteins SgpA and SgpB and the smaller 8.5-kDa SgpC. Reporter gene fusions of sgpA and alkaline phosphatase showed the

Alexander Prange; Harald Engelhardt; Hans G. Trüper; Christiane Dahl

2004-01-01

186

Process for production of synthesis gas with reduced sulfur content  

DOEpatents

A process for the partial oxidation of a sulfur- and silicate-containing carbonaceous fuel to produce a synthesis gas with reduced sulfur content which comprises partially oxidizing said fuel at a temperature in the range of 1800.degree.-2200.degree. F. in the presence of a temperature moderator, an oxygen-containing gas and a sulfur capture additive which comprises an iron-containing compound portion and a sodium-containing compound portion to produce a synthesis gas comprising H.sub.2 and CO with a reduced sulfur content and a molten slag which comprises (i) a sulfur-containing sodium-iron silicate phase and (ii) a sodium-iron sulfide phase. The sulfur capture additive may optionally comprise a copper-containing compound portion.

Najjar, Mitri S. (Hopewell Junction, NY); Corbeels, Roger J. (Wappingers Falls, NY); Kokturk, Uygur (Wappingers Falls, NY)

1989-01-01

187

Graphene-sulfur nanocomposites for rechargeable lithium-sulfur battery electrodes  

SciTech Connect

Rechargeable lithium-sulfur batteries having a cathode that includes a graphene-sulfur nanocomposite can exhibit improved characteristics. The graphene-sulfur nanocomposite can be characterized by graphene sheets with particles of sulfur adsorbed to the graphene sheets. The sulfur particles have an average diameter less than 50 nm..

Liu, Jun; Lemmon, John P; Yang, Zhenguo; Cao, Yuiliang; Li, Xiaolin

2014-06-17

188

Sugar yields from dilute sulfuric acid and sulfur dioxide pretreatments and subsequent enzymatic hydrolysis of switchgrass  

E-print Network

Sugar yields from dilute sulfuric acid and sulfur dioxide pretreatments and subsequent enzymatic Dilute sulfuric acid Sulfur dioxide Biofuels Switchgrass a b s t r a c t Dacotah switchgrass was pretreated with sulfuric acid concentrations of 0.5, 1.0, and 2.0 wt.% at 140, 160, and 180 °C and with 1

California at Riverside, University of

189

Sulfur Dioxide Crossover during the Production of Hydrogen and Sulfuric Acid in a PEM Electrolyzer  

E-print Network

Sulfur Dioxide Crossover during the Production of Hydrogen and Sulfuric Acid in a PEM Electrolyzer in the thermochemical conversion of sulfur dioxide to sulfuric acid for the large-scale production of hydrogen-17 In this thermochemical cycle, sulfuric acid is decomposed at high temperature 850°C to SO2 and wa- ter, and the SO2

Weidner, John W.

190

Thermal behavior of the sulfur electrolyte in sodium-sulfur battery concepts  

SciTech Connect

The composition range and the temperature limits for the sulfur electrolyte in sodium-sulfur battery concepts extends from the molten polysulfide phase into and through the region of molten pulse-molten sulfur phase separation, to elemental sulfur. Investigations of the thermal behavior of the sulfur electrolyte (melting-crystallizatio

Janz, G.J.; Rogers, D.J.

1983-01-01

191

Toxicology of sulfur in ruminants: review  

SciTech Connect

This review deals with the toxicology of sulfur in ruminants including toxicity, neurotoxic effects, and mechanism of toxic action of hydrogen sulfide, clinical signs, and treatment. It will report effects of excessive intake of sulfur by ruminants on feed intake, animal performance, ruminal digestion and motility, rumination, and other physiological functions. Poisoning of animals with sulfur from industrial emissions (sulfur dioxide) also is discussed. Excessive quantities of dietary sulfur (above .3 to .4%) as sulfate or elemental sulfur may cause toxic effects and in extreme cases can be fatal. The means is discussed whereby consumption of excessive amounts of sulfur leads to toxic effects. 53 references, 1 table.

Kandylis, K.

1984-10-01

192

Sulfur-Free Selective Pulping  

E-print Network

A joint research effort is being conducted on ways to produce cost-effective pulping catalysts from lignin. This project addresses improving selectivities and reducing the levels of sulfur chemicals used in pulping. Improved selectivity means...

Dimmel, D. R.; Bozell, J. J.

193

Photometric properties of powdered sulfur  

NASA Astrophysics Data System (ADS)

Particle size, temperature, thermal history, and scattering geometry are shown by the present laboratory investigation of the spectrophotometric properties of three particle-size fractions of sulfur to influence the spectral reflectance of both normal and quenched molten samples of sulfur. A scattering law that consists of a linear combination of lunar-like and Lambertian terms adequately describes the data for all particle sizes. Near opposition, sulfur particles closely follow a Minnaert limb darkening law except where the reflectance is low, as in the strong UV absorption band of the larger particle size fractions. The present data indicate that quantitative comparisons between disk-integrated observations of Io and laboratory measurements of flat sulfur samples are inadequate unless temperature effects and scattering geometry changes are included.

Gradie, J.; Veverka, J.

1984-05-01

194

Radiolysis of sulfuric acid, sulfuric acid monohydrate, and sulfuric acid tetrahydrate and its relevance to Europa  

Microsoft Academic Search

We report laboratory studies on the 0.8MeV proton irradiation of ices composed of sulfuric acid (H2SO4), sulfuric acid monohydrate (H2SO4·H2O), and sulfuric acid tetrahydrate (H2SO4·4H2O) between 10 and 180K. Using infrared spectroscopy, we identify the main radiation products as H2O, SO2, (S2O3)x, H3O+, HSO4-, and SO42-. At high radiation doses, we find that H2SO4 molecules are destroyed completely and that

M. J. Loeffler; R. L. Hudson; M. H. Moore; R. W. Carlson

2011-01-01

195

Thermophilic Carbon-Sulfur-Bond-Targeted Biodesulfurization  

PubMed Central

Petroleum contains many heterocyclic organosulfur compounds refractory to conventional hydrodesulfurization carried out with chemical catalysts. Among these, dibenzothiophene (DBT) and DBTs bearing alkyl substitutions are representative compounds. Two bacterial strains, which have been identified as Paenibacillus strains and which are capable of efficiently cleaving carbon-sulfur (C--S) bonds in DBT at high temperatures, have been isolated for the first time. Upon attacking DBT and its various methylated derivatives at temperatures up to 60(deg)C, both growing and resting cells of these bacteria can release sulfur atoms as sulfate ions and leave the monohydroxylated hydrocarbon moieties intact. Moreover, when either of these paenibacilli was incubated at 50(deg)C with light gas oil previously processed through hydrodesulfurization, the total sulfur content in the oil phase clearly decreased. PMID:16535672

Konishi, J.; Ishii, Y.; Onaka, T.; Okumura, K.; Suzuki, M.

1997-01-01

196

Zirconium in sulfuric acid applications  

SciTech Connect

Zirconium is one of the few metals that resists attack by sulfuric acid at concentrations up to 75% and temperatures to boiling and above. This capability makes zirconium a good structural metal for use in 40 to 65% H/sub 2/SO/sub 4/ up to boiling temperatures and for weak acid concentrations at elevated temperatures. Zirconium's corrosion properties in sulfuric acid solutions are compared with nickel base alloys. Examples of applications and limitations in the use of zirconium are presented.

Webster, R.T.; Yau, T.L.

1986-02-01

197

TOXICITY OF VARIOUS ORGANIC SULFUR COMPOUNDS FOR CHICKS FED CRYSTALLINE AMINO ACID DIETS CONTAINING THREONINE AND GLYCINE AT THEIR MINIMAL DIETARY REQUIREMENTS FOR MAXIMAL GROWTH  

Microsoft Academic Search

SUMMARY Five growth assays were conducted with young chicks to study relative toxicities of various organic sulfur compounds. Evaluation of the dietary requirements for glycine and threonine indicated that .52% threonine and .51% glycine were the minimum requirements for maximal gain. To provide a margin of safety .55% threonine and .60% glycine were chosen as levels to use in subsequent

Robert S. Katz; David H. Baker

198

SULFUR (S) Role of S in plants  

E-print Network

SULFUR #12;SULFUR (S) · Role of S in plants Component of amino acids Essential for nitrate sulfur #12;Sulfur Removed by Crops Portion Sulfur Crop harvested Yield/acre removed -- lb/acre -- Alfalfa S/a for 1% OM · S in rain & snow ­ 10 or 20 lb S/a · S in subsoil 5, 10, or 20 lb S/a · S in manure

Balser, Teri C.

199

The fate of sulfur during rapid pyrolysis of scrap tires.  

PubMed

The fate of sulfur during rapid pyrolysis of scrap tires at temperatures from 673 to 1073K was investigated. Sulfur was predominant in the forms of thiophenic and inorganic sulfides in raw scrap tires. In the pyrolysis process, sulfur in organic forms was unstable and decomposed, leading to the sulfur release into tar and gases. At 673 and 773K, a considerable amount of sulfur was distributed in tar. Temperature increasing from 773 to 973K promoted tar decomposition and facilitated sulfur release into gases. At 1073K, the interactions between volatiles and char stimulated the formation of high-molecular-weight sulfur-containing compounds. After pyrolysis, almost half of the total content of sulfur in raw scrap tires still remained in the char and was mostly in the form of sulfides. Moreover, at temperatures higher than 873K, part of sulfur in the char was immobilized in the sulfates. In the pyrolysis gases, H2S was the main sulfur-containing gas. Increasing temperature stimulated the decomposition of organic polymers in scrap tires and more H2S was formed. Besides H2S, other sulfur-containing gases such as CH3SH, COS and SO2 were produced during the rapid pyrolysis of scrap tires. PMID:24238304

Hu, Hongyun; Fang, Yuan; Liu, Huan; Yu, Ren; Luo, Guangqian; Liu, Wenqiang; Li, Aijun; Yao, Hong

2014-02-01

200

TECHNIQUE FOR MEASURING REDUCED FORMS OF SULFUR IN AMBIENT AIR  

EPA Science Inventory

A new technique for measuring low concentrations of volatile sulfur compounds in ambient air is discussed. The technique consists of preconcentration of sulfur compounds by chemisorption on gold metal coated sand or gold foil surface followed by thermal desorption, separation, an...

201

Identification of the chemical form of sulfur compounds in the Japanese pink coral (Corallium elatius) skeleton using ?-XRF/XAS speciation mapping.  

PubMed

The distributions and chemical forms of sulfur compounds in the skeleton of Japanese pink coral (Corallium elatius) were investigated using X-ray spectroscopic techniques combined with micro-focused soft X-ray radiation. Microscopic X-ray fluorescence/soft X-ray photoabsorption (?-XRF/XAS) speciation mapping clarified that sulfate is the primary species in the coral skeleton, with minor amounts of organic sulfur, whereas both sulfate and organic sulfur coexist in coenenchyme. Analysis of the post-edge region of the XAS spectra confirmed that sulfate ions in the coral skeleton are mainly in the form of gypsum-like inorganic sulfate substituting for the carbonate ions in the calcite skeleton. The sulfate concentration was negatively correlated with the magnesium concentration and positively correlated with that of phosphorus. Speciation mapping of sulfate in the coral skeleton showed clear fluctuations with sulfate concentrations being higher at dark bands, whereas the small amount of organic sulfur had unclear dark/bright bands. These results suggest that the little organic sulfur that is present is contained in the organic matter embedded in the biocrystal of coral skeleton. PMID:24727132

Tamenori, Yusuke; Yoshimura, Toshihiro; Luan, Nguyen Trong; Hasegawa, Hiroshi; Suzuki, Atsushi; Kawahata, Hodaka; Iwasaki, Nozomu

2014-05-01

202

Photochemical oxidation and dispersion of gaseous sulfur compounds from natural and anthropogenic sources around a coastal location  

NASA Astrophysics Data System (ADS)

The photochemical oxidation and dispersion of reduced sulfur compounds (RSCs: H 2S, CH 3SH, DMS, CS 2, and DMDS) emitted from anthropogenic (A) and natural (N) sources were evaluated based on a numerical modeling approach. The anthropogenic emission concentrations of RSCs were measured from several sampling sites at the Donghae landfill (D-LF) (i.e., source type A) in South Korea during a series of field campaigns (May through December 2004). The emissions of natural RSCs in a coastal study area near the D-LF (i.e., source type N) were estimated from sea surface DMS concentrations and transfer velocity during the same study period. These emission data were then used as input to the CALPUFF dispersion model, revised with 34 chemical reactions for RSCs. A significant fraction of sulfur dioxide (SO 2) was produced photochemically during the summer (about 34% of total SO 2 concentrations) followed by fall (21%), spring (15%), and winter (5%). Photochemical production of SO 2 was dominated by H 2S (about 55% of total contributions) and DMS (24%). The largest impact of RSCs from source type A on SO 2 concentrations occurred around the D-LF during summer. The total SO 2 concentrations produced from source type N around the D-LF during the summer (a mean SO 2 concentration of 7.4 ppbv) were significantly higher than those (?0.3 ppbv) during the other seasons. This may be because of the high RSC and SO 2 emissions and their photochemistry along with the wind convergence.

Song, Sang-Keun; Shon, Zang-Ho; Kim, Ki-Hyun

203

Characterization and quantification of the oxides of sulfur and nitrogen and associated compounds in their gaseous, aerosol, and dissolved states  

SciTech Connect

The needs and problems associated with the characterization and quantification of the oxides of sulfur and nitrogen and associated compounds in their gaseous, aerosol, and dissolved states are discussed. Illustrations are given of the techniques in present usage for the determination of the substances of interest to investigators concerned with the effects of air pollutants on the terrestrial ecosystem. The value and utility of the newer techniques employing real time continuous instrumentation are presented and compared with the more traditional approaches utilizing sampling collection. A plea is made to provide resources for data reduction especially in order to obtain constructive utilization of continuous instrumentation. It is asserted that real time instrumentation is best utilized during campaign measurement programs where short time resolution is required and that collection techniques still have a place, especially in long term monitoring efforts. Special attention was directed at, and the problems highlighted that are associated with, the utilization of the real time instruments available for the flame photometric determination of the oxides of sulfur and the chemiluminescent measurement of the oxides of nitrogen. The newer methods proposed for their use in the determination of sulfate and nitric acid respectively are presented. The difficulties associated with the determination of nitrate are enunciated and attention focused on the problems of obtaining a sample due to the variation of the vapor pressure of gaseous nitric acid and ammonia above solid ammonium nitrate which is in association with an acidic aerosol containing sulfate. The utility of measurements of the composition of rainwater is discussed in light of its application to determine the mechanisms through which rain derives its chemical composition.

Newman, L

1980-05-01

204

Measuring global sulfur dioxide emissions with satellite sensors  

NASA Astrophysics Data System (ADS)

Atmospheric sulfur dioxide affects the weather by enhancing cloud formation, and long-term shifts in emissions can change the climate by increasing the amount of solar radiation scattered back into space. Sulfur dioxide emissions are the basis for acid rain, and the gas itself can cause respiratory problems. Despite the compound's importance to climate, the difficulties associated with accurately measuring sulfur dioxide mean that rates of emissions are generally not well understood.

Schultz, Colin

2013-11-01

205

Intermediate sulfur oxidation state compounds in the euxinic surface sediments of the Dvurechenskii mud volcano (Black Sea)  

NASA Astrophysics Data System (ADS)

The deep Black Sea is known to be depleted in electron-acceptors for sulfide oxidation. This study on depth distributions of sulfur species (S(II), S(0), Sn2-, SO32-, SO32-, SO42-) in the Dvurechenskii mud volcano, a cold seep situated in the permanently anoxic eastern Black Sea basin (Sorokin Trough, 2060 m water depth), showed remarkable concentrations of sulfide oxidation products. Sulfite concentrations of up to 11 ?mol L-1, thiosulfate concentrations of up to 22 ?mol L-1, zero-valent sulfur concentrations of up to 150 ?mol L-1 and up to five polysulfide species were measured in the upper 20 cm of the sediment. Electron-acceptors found to be available in the Dvurechenskii mud volcano (DMV) for the oxidation of hydrogen sulfide to sulfide oxidation intermediates are iron-minerals, and probably also reactive manganese phases. Up to 60 ?mol g-1 of reactive iron-minerals and up to 170 ?mol L-1 dissolved iron was present in the central summit with the highest fluid upflow and fresh mud outflow. Thus, the source for the oxidative power in the DMV are reactive iron phases extruded with the mud from an ancient source in the deeply buried sediments, leading to the formation of various sulfur intermediates in comparably high concentrations. Another possible source of sulfide oxidation intermediates in DMV sediments could be the formation of zero-valent sulfur by sulfate dependent anaerobic microbial oxidation of methane followed by disproportionation of zero-valent sulfur. Sulfide oxidation intermediates, which are produced by these processes, do not reach thermodynamic equilibrium with rhombic sulfur, especially close to the active center of the DMV due to a short equilibration time. Thus, mud volcano sediments, such as in the DMV, can provide oxidizing niches even in a highly reduced environment like the abyssal part of the Black Sea.

Lichtschlag, Anna; Kamyshny, Alexey; Ferdelman, Timothy G.; deBeer, Dirk

2013-03-01

206

Neutralization and biodegradation of sulfur mustard  

SciTech Connect

One technology recommended for consideration for the disposal of the U.S. Chemical Stockpile is chemical neutralization followed by biodegradation. In the case of sulfur mustard ({open_quotes}mustard gas{close_quotes}, 2,2{prime}-dichlorodiethyl sulfide), alkaline hydrolysis yields a detoxified and biodegradable product. The hydrolysis reaction was studied with respect to the effects of temperature and sulfur mustard concentration on the rate and products of the reaction. A 28-fold overall rate enhancement was observed at 70{degrees}C vs. 30{degrees}C corresponding to an enthalpy of activation value of 17.9 Kcal/mole. Material balance studies conducted by {sup 1}H Nuclear Magnetic Resonance analysis showed that the products of the reaction consisted of thiodiglycol was relatively greater at lower sulfur mustard concentrations and higher temperatures. As temperatures were decreased or sulfur mustard concentrations was increased, the proportion of ether-type compounds increased accordingly. Conditions of 1% (vol//vol) sulfur mustard, 5% stoichiometric excess of NaOH and 90{degrees}C were selected for generation of the hydrolyzed bioreactor influent material. The bioreactor was seeded with activated sludge and was initially operated as 5 liter sequencing batch reactor with a hydraulic residence time of approximately days. Early results show total organic carbon removal of greater than 90%.

Harvey, S.P.; Beaudry, W.T.; Szafraniec, L.L. [and others

1995-12-31

207

Sulfuric acid in the Venus clouds.  

NASA Technical Reports Server (NTRS)

The extremely dry nature of the Venus upper atmosphere appears to demand the presence of an efficient desiccating agent as the chief constituent of the clouds of Venus. On the basis of polarization measures it is to be expected that this substance is present as spherical droplets, 1 to 2 microns in diameter, with a refractive index n of 1.46 plus or minus 0.02 at 3500A in the observed region of the atmosphere, with T about equal to 235 K. This substance must have ultraviolet, visible, and infrared reflection properties not inconsistent with the observed spectrum of Venus. Sulfuric acid, of about 86% by weight composition, roughly fulfills the first of these properties. The visible and ultraviolet transmission features of a thin layer of elemental bromine and hydrobromic acid dissolved in sulfuric acid somewhat resemble the Venus spectrum, up to 14 microns. The chemical process postulated for forming sulfuric acid involves the oxidation of sulfur and its compounds to sulfuric acid through the agency of elemental bromine produced by the photolytic decomposition of hydrogen bromide.

Sill, G. T.

1972-01-01

208

The sulfurized InP surface  

SciTech Connect

Sulfur treatments have previously been shown to improve the electrical characteristics of InP and GaAs devices. This paper reports the results of an Auger/x-ray photoelectron spectroscopy investigation of the InP surface after sulfur treatment. It is shown that the sulfur remains on the surface bonded to indium. There is no indication of elemental sulfur or sulfur bonded to phosphorus. This suggests that the sulfur has replaced phosphorus on the surface and has filled the phosphorus vacancies.

Wilmsen, C. W.; Geib, K. M.; Shin, J.; Iyer, R.; Lile, D. L.; Pouch, J. J.

1989-07-01

209

Sulfuric Acid on Europa's Surface and the Radiolytic Sulfur Cycle  

Microsoft Academic Search

Galileo infrared spectra of Europa's surface show distorted water bands that have been attributed to hydrated evaporite salts (McCord et al., J. Geophys. Res. 104, 11827, 1999) or to the scattering properties of ice (Dalton and Clark, Bull. Am. Astron. Soc. 30, 1081, 1998). Using new laboratory spectra, we show that hydrated sulfuric acid can explain Europa's spectra and further

R. W. Carlson; R. E. Johnson; M. S. Anderson

1999-01-01

210

The Speciation of Sulfur in an Ocean on Europa  

NASA Technical Reports Server (NTRS)

Stability of native sulfur, iron sulfides, and aqueous sulfur compounds is evaluated at assumed P-T conditions of the Europa's ocean floor. Pyrite, gypsum, and ferric hydroxides can coexist in contact with sulfate-rich oceanic water. Additional information is contained in the original extended abstract.

Zolotov, M. Yu.; Shock, E. L.

2002-01-01

211

Mass-dependent sulfur isotope fractionation during reoxidative sulfur cycling: A case study from Mangrove Lake, Bermuda  

NASA Astrophysics Data System (ADS)

The multiple sulfur isotope composition of porewater sulfate from the anoxic marine sapropel of Mangrove Lake, Bermuda was measured in order to establish how multiple sulfur isotopes are fractionated during reoxidative sulfur cycling. The porewater-sulfate ?34S and ?33S dataset exhibits the distinct isotopic signatures of microbial sulfate reduction and sulfur reoxidation. We reproduced the measurements with a simple diagenetic model that yielded fractionation factors for net sulfate removal of between -29.2‰ and -32.5‰. A new approach to isotopic modeling of the sulfate profiles, informed by the chemistry of sulfur intermediate compounds in Mangrove Lake, reveals that sulfate reduction produces a relatively small intrinsic fractionation and that an active reoxidative sulfur cycle increases the fractionation of the measured values. Based on the model results, the reoxidative cycle of Mangrove Lake appears to include sulfide oxidation to elemental sulfur followed by the disproportionation of the elemental sulfur to sulfate and sulfide. This model also indicates that the reoxidative sulfur cycle of Mangrove Lake turns over from 50 to 80% of the sulfide produced by microbial sulfate reduction. The Mangrove Lake case study shows how sulfur isotope fractionations can be separated into three different “domains” in ?33S-?34S space based on their ability to resolve reductive and reoxidative sulfur transformations. The first domain that differentiates reductive and reoxidative sulfur cycling is well illustrated by previous studies and requires 34S-32S fractionations more negative than ?-70‰, beyond the fractionation limit of microbial sulfate reduction at earth surface temperatures. The second domain that distinguishes reductive and reoxidative processes is between 34S-32S fractionations of -40‰ and 0‰, where the 33S-32S fractionations of sulfate reduction and reoxidation are significantly different. In the remaining domain (between 34S-32S fractionations -70‰ and -40‰), the similarity of the multiple sulfur isotope signals from microbial sulfate reduction and disproportionation means that the two processes cannot be discriminated from each other.

Pellerin, André; Bui, Thi Hao; Rough, Mikaella; Mucci, Alfonso; Canfield, Donald E.; Wing, Boswell A.

2015-01-01

212

46 CFR 148.315 - Sulfur.  

Code of Federal Regulations, 2013 CFR

... (c) A cargo space that contains sulfur or the residue of a sulfur cargo must be adequately ventilated, preferably by mechanical means. Each ventilator intake must be fitted with a spark-arresting...

2013-10-01

213

46 CFR 148.315 - Sulfur.  

Code of Federal Regulations, 2011 CFR

... (c) A cargo space that contains sulfur or the residue of a sulfur cargo must be adequately ventilated, preferably by mechanical means. Each ventilator intake must be fitted with a spark-arresting...

2011-10-01

214

46 CFR 148.315 - Sulfur.  

Code of Federal Regulations, 2014 CFR

... (c) A cargo space that contains sulfur or the residue of a sulfur cargo must be adequately ventilated, preferably by mechanical means. Each ventilator intake must be fitted with a spark-arresting...

2014-10-01

215

46 CFR 148.315 - Sulfur.  

Code of Federal Regulations, 2012 CFR

... (c) A cargo space that contains sulfur or the residue of a sulfur cargo must be adequately ventilated, preferably by mechanical means. Each ventilator intake must be fitted with a spark-arresting...

2012-10-01

216

Three-Zone Catalyst Resists Sulfur Poisoning  

NASA Technical Reports Server (NTRS)

Three-zone catalyst bed uses different types of nickel catalysts to convert sulfur-containing hydrocarbon fuels to hydrogen and carbon monoxide. Zones designed to achieve conversion with minimal residue of unconverted hydrocarbon, no soot and mimimal sulfur contamination.

Voecks, G. E.; Stephanopoulos, M. F.; Houseman, J.

1984-01-01

217

Formation of Nitrogen- and Sulfur-Containing Light-Absorbing Compounds Accelerated by Evaporation of Water from Secondary Organic Aerosols  

SciTech Connect

Aqueous extracts of secondary organic aerosols (SOA) generated from the ozonolysis of dlimonene were subjected to dissolution, evaporation, and re-dissolution in the presence and absence of ammonium sulfate (AS). Evaporation with AS at pH 4-9 produced chromophores that were stable with respect to hydrolysis and had a distinctive absorption band at 500 nm. Evaporation accelerated the rate of chromophore formation by at least three orders of magnitude compared to the reaction in aqueous solution, which produced similar compounds. Absorption spectroscopy and high-resolution nanospray desorption electrospray ionization (nano-DESI) mass spectrometry experiments suggested that the molar fraction of the chromophores was small (< 2%), and that they contained nitrogen atoms. Although the colored products represented only a small fraction of SOA, their large extinction coefficients (>10{sup 5} L mol{sup -1} cm{sup -1} at 500 nm) increased the effective mass absorption coefficient of the residual organics in excess of 10{sup 3} cm{sup 2} g{sup -1} - a dramatic effect on the optical properties from minor constituents. Evaporation of SOA extracts in the absence of AS resulted in the production of colored compounds only when the SOA extract was acidified to pH {approx} 2 with sulfuric acid. These chromophores were produced by acid-catalyzed aldol condensation, followed by a conversion into organosulfates. The presence of organosulfates was confirmed by high resolution mass spectrometry experiments. Results of this study suggest that evaporation of cloud or fog droplets containing dissolved organics leads to significant modification of the molecular composition and serves as a potentially important source of light-absorbing compounds.

Nguyen, Tran B.; Lee, Paula B.; Updyke, Katelyn M.; Bones, David L.; Laskin, Julia; Laskin, Alexander; Nizkorodov, Sergey

2012-01-14

218

Emissions of reduced sulfur compounds (RSC) as a landfill gas (LFG): A comparative study of young and old landfill facilities  

NASA Astrophysics Data System (ADS)

To offer some insights into the processes associated with odor release from a strong source environment, concentrations of reduced sulfur compounds (RSCs) in landfill gas (LFG) were measured at two landfill (LF) facilities within a small city boundary through four seasons. The LF sites investigated in this study are distinguished in that the young LF (namely, YLF) was selected to represent a site of active RSC emissions, while the old LF (namely, OLF) was selected for its weak RSC emissions. The LFG composition, when analyzed for a number of RSCs (hydrogen sulfide (H 2S), methyl mercaptan (CH 3SH), dimethyl sulfide ((CH 3) 2S), carbon disulfide (CS 2) and dimethyl disulfide ((CH 3) 2S 2)), was consistently predominated by H 2S from both sites. The mean and SD value of H 2S in the YLF were measured to be 139,070±144,340 ppb, while its counterparts in the OLF being 3.86±3.41 ppb. The emission concentration levels of H 2S were found to be distinguished from those of the other RSCs, depending on the LF aging. The H 2S results for both LF sites, when compared across seasons, were generally characterized as notable enhancement during summer relative to other seasons. The comparative analysis of relative composition between RSCs and other LFG constituents (such as CH 4, CO 2, and VOC) consistently indicate that the relative proportion of RSCs is substantially larger during the active LF stage (YLF) than in the inactive one (OLF).

Kim, Ki-Hyun

219

The averaging effect of odorant mixing as determined by air dilution sensory tests: a case study on reduced sulfur compounds.  

PubMed

To learn more about the effects of mixing different odorants, a series of air dilution sensory (ADS) tests were conducted using four reduced sulfur compounds [RSC: hydrogen sulfide (H(2)S), methanethiol (CH(3)SH), dimethylsulfide (DMS), and dimethyldisulfide (DMDS)] at varying concentration levels. The tests were initially conducted by analyzing samples containing single individual RSCs at a wide range of concentrations. The resulting data were then evaluated to define the empirical relationship for each RSC between the dilution-to-threshold (D/T) ratio and odor intensity (OI) scaling. Based on the relationships defined for each individual RSC, the D/T ratios were estimated for a synthetic mixture of four RSCs. The effect of mixing was then examined by assessing the relative contribution of each RSC to those estimates with the aid of the actually measured D/T values. This stepwise test confirmed that the odor intensity of the synthetic mixture is not governed by the common theoretical basis (e.g., rule of additivity, synergism, or a stronger component model) but is best represented by the averaged contribution of all RSC components. The overall results of this study thus suggest that the mixing phenomenon between odorants with similar chemical properties (like RSC family) can be characterized by the averaging effect of all participants. PMID:22319360

Kim, Ki-Hyun

2011-01-01

220

The emission characteristics and the related malodor intensities of gaseous reduced sulfur compounds (RSC) in a large industrial complex  

NASA Astrophysics Data System (ADS)

In this study, the concentrations of major reduced sulfur compounds (RSC: H 2S, CH 3SH, DMS, CS 2 and DMDS) were determined from various emission sources located within the Ban-Wall (BW)/ Si-Hwa (SH) industrial complex in Ansan city, Korea. The measurement data were obtained from a total of 202 individual points at 77 individual companies during 2004-2005. The highest RSC concentration levels came most dominantly from H 2S (300 (mean) and 0.86 ppb (median)) followed by CS 2, while the results of CH 3, DMS, and DMDS are notably lower at the mean concentration levels of a few ppb. These data were evaluated further after being grouped into two different classification schemes: 9 industry sectors and 9 processing unit types. The strongest emissions of RSC, when evaluated among different industry sectors, are generally found from such industry types as leather, food, paper/pulp, as well as waste/sewage related ones. In contrast, when these RSC data are compared across different processing units, the highest values were seen most frequently from such units as junction boxes, aeration tanks, and settling tanks. The assessment of data in terms of relative contribution to malodor intensity showed that H 2S and CH 3SH are more important than others. The overall results of the present study suggest that information combining RSC speciation and types of anthropogenic activities may be used to distinguish the patterns of odorous pollution in areas affected by strong source processes.

Kim, Ki-Hyun; Jeon, Eui-Chan; Choi, Ye-Jin; Koo, Youn-Seo

221

System for handling high sulfur materials  

Microsoft Academic Search

Sulfur oxides have a strong affinity for free lime and readily form gypsum anhydrite. By utilizing 2200°F or higher on-gas containing reduced quantities of sulfur to the preheat zone of a material treating apparatus, large quantities of sulfur can be removed from gases evolved in the rotary kiln. Utilizing lower sulfur content on-gas to preheat will substantially improve the ability

G. A. Heian; R. F. Kohl

1978-01-01

222

Involvement of Intermediate Sulfur Species in Biological Reduction of Elemental Sulfur under Acidic, Hydrothermal Conditions  

E-print Network

Involvement of Intermediate Sulfur Species in Biological Reduction of Elemental Sulfur under Acidic-Purdue University, Indianapolis, Indianapolis, Indiana, USAb The thermoacidophile and obligate elemental sulfur (S8-phase sulfur during S8 0 -dependent batch culture growth. Cyclic voltammetry indicated the production

Ahmad, Sajjad

223

Sulfuric acid versus elemental sulfur as by-products. Final report  

Microsoft Academic Search

An economic comparison of sulfuric acid production and sulfur recovery processes was made on eastern coal feeds in this study. Sulfuric acid is the more attractive product whenever assured markets are available, on the basis of rail transportation of by-products. The capital cost is higher for a plant to recover the sulfur, and the product value is lower per unit

1978-01-01

224

Sulfur hexafluoride as a surrogate  

SciTech Connect

A viable chemical surrogate for monitoring the effectiveness of hazardous waste incinerators must include high thermal stability and low toxicity among its characteristics. The relationship between sulfur hexafluoride (SF6) and hazardous constituent thermal stability for a mixture of chlorinated hydrocarbons indicates that SF6 has the potential to satisfy the basic requirements of a chemical surrogate for hazardous waste incineration.

Taylor, P.H.; Chadbourne, J.F.

1987-06-01

225

Sulfur-tolerant anode materials  

NASA Astrophysics Data System (ADS)

Results of the second year's technical effort on a program to identify and evaluate alternative anode materials for use in molten carbonate fuel cells (MCFC) operating with high levels of sulfur contaminants in the fuel are summarized. In the first year of this program, a literature survey was performed covering all materials development research relating to electrode development for molten carbonate fuel cells. A final selection of 15 candidate materials was made, and samples of 9 of these 15 materials were fabricated and tested for electrical conductivity and for stability in the molten electrolyte. An additional 5 materials were evaluated during the second year. Several water-gas shift catalysts were also evaluated for their catalytic activity and sulfur resistance under conditions prevailing in the MCFC anode. These materials were titanium carbide, cobalt metal, copper metal, copper-nickel alloy, and lithium ferrate (III). Only the lithium ferrate (III) exhibited sulfur tolerance in that the performance of the lithium ferrate (III) cell did not change when sulfur was added to the fuel. The lithium ferrate (III) was then used to fabricate anodes for two 100 cm(2) bench-scale cells. These cells were assembled and operated on a medium-Btu simulated coal gasifier-derived fuel. Results are discussed.

Remick, Robert J.; Osif, Terry L.; Lawson, M. G.

1988-09-01

226

Nutrient cyling in soils: Sulfur  

Technology Transfer Automated Retrieval System (TEKTRAN)

Sulfur (S) is an essential element required for normal plant growth, a fact that has been recognized since the nineteenth century. It is considered a secondary macronutrient, following the primary macronutrients nitrogen (N), phosphorus (P), and potassium (K), but is needed by plants at levels compa...

227

Seal for sodium sulfur battery  

DOEpatents

This invention is directed to a seal for a sodium sulfur battery in which the sealing is accomplished by a radial compression seal made on a ceramic component of the battery which separates an anode compartment from a cathode compartment of the battery.

Topouzian, Armenag (Birmingham, MI); Minck, Robert W. (Lathrup Village, MI); Williams, William J. (Northville, MI)

1980-01-01

228

Sodium--sulfur storage battery  

Microsoft Academic Search

This invention relates to a novel sodium--sulfur storage battery comprising a sodium reservoir made of metal (incorporating a heater) between double walls, a solid electrolyte connected to it, an anodic reactant contained in it and a cathode reactant outside of it, and a battery housing which contains the above-mentioned components. The battery is sealed at the upper part. According to

Kagawa

1977-01-01

229

SULFUR DIOXIDE SOURCES IN AK  

EPA Science Inventory

This map shows industrial plants which emit 100 tons/year or more of sulfur dioxide (SO2) in Alaska. The SO2 sources are plotted on a background map of cities and county boundaries. Data Sources: SO2 Sites: U.S. EPA AIRS System, County Outlines: 1990 Census Tiger Line Files 1:1...

230

VICARIOUS NUCLEOPHILIC SUBSTITUTION WITH SULFUR CONTAINING CARBANIONS  

Microsoft Academic Search

Carbanions stabilized with sulfur containing substituents are versatile intermedi-ates in organic synthesis. The great value and importance of such carbanions is connected with specific properties of the sulfur atom which is capable to exist in a variety of valent states and to form many functional groups. These various sulfur-containing groups exert different carbanion stabilizing effects and can also serve as

Mieczyslaw M?jkosza; Witold Danikiewicz; Krzysztof Wojciechowski

1990-01-01

231

8, 54135436, 2008 Ammonia in sulfuric  

E-print Network

ACPD 8, 5413­5436, 2008 Ammonia in sulfuric acid ion induced nucleation I. K. Ortega et al. Title.0 License. Atmospheric Chemistry and Physics Discussions The role of ammonia in sulfuric acid ion induced­5436, 2008 Ammonia in sulfuric acid ion induced nucleation I. K. Ortega et al. Title Page Abstract

Boyer, Edmond

232

Air Quality Criteria for Sulfur Oxides.  

ERIC Educational Resources Information Center

Included is a literature review which comprehensively discusses knowledge of the sulfur oxides commonly found in the atmosphere. The subject content is represented by the 10 chapter titles: Physical and Chemical Properties and the Atmospheric Reactions of the Oxides of Sulfur; Sources and Methods of Measurements of Sulfur Oxides in the Atmosphere;…

National Air Pollution Control Administration (DHEW), Washington, DC.

233

46 CFR 153.1046 - Sulfuric acid.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false Sulfuric acid. 153.1046 Section 153...CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED...Procedures § 153.1046 Sulfuric acid. No person may liquefy frozen or congealed sulfuric acid other than by external tank...

2011-10-01

234

46 CFR 153.1046 - Sulfuric acid.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Sulfuric acid. 153.1046 Section 153...CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED...Procedures § 153.1046 Sulfuric acid. No person may liquefy frozen or congealed sulfuric acid other than by external tank...

2010-10-01

235

46 CFR 153.1046 - Sulfuric acid.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Sulfuric acid. 153.1046 Section 153...CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED...Procedures § 153.1046 Sulfuric acid. No person may liquefy frozen or congealed sulfuric acid other than by external tank...

2013-10-01

236

46 CFR 153.1046 - Sulfuric acid.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 false Sulfuric acid. 153.1046 Section 153...CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED...Procedures § 153.1046 Sulfuric acid. No person may liquefy frozen or congealed sulfuric acid other than by external tank...

2012-10-01

237

46 CFR 153.1046 - Sulfuric acid.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 false Sulfuric acid. 153.1046 Section 153...CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED...Procedures § 153.1046 Sulfuric acid. No person may liquefy frozen or congealed sulfuric acid other than by external tank...

2014-10-01

238

Effects of allyl sulfur compounds and garlic extract on the expressions of Bcl2, Bax, and p53 in non small cell lung cancer cell lines  

Microsoft Academic Search

Allyl sulfur compounds play a major role in the chemoprevention against carcinogenesis. The pre- sent study compared the antiproliferative effects of diallyl sulfide (DAS), diallyl disulfide (DADS) and garlic extract on p53-wild type H460 and p53-null type H1299 non small cell lung cancer cells (NSCLC). The DAS and DADS treatment of both H460 and H1299 cells resulted in the highest

Young-Sook Hong; Yoon-Ae Ham; Ji-Hyung Choi; Jhingook Kim

2000-01-01

239

Garlic powder and Allyl sulfur compounds enhance the ability of dietary selenite to inhibit 7,12?dimethylbenz[a]anthracene?induced mammary DNA adducts  

Microsoft Academic Search

These studies examined the ability of garlic powder or allyl sulfur compounds to modify selenite protection against 7,12?dimethylbenz[a] anthracene (DMBA)?induced mammary epithelial cell DNA adducts. In Study 1, female rats (n = 5) were fed diets containing sodium selenite at 0.1, 0.5, or 1.0 mg Selkg and garlic powder at 0, 20, or 40 g\\/kg diet. Total DNA adducts correlated

Eric M. Schaffer; John A. Milner

1997-01-01

240

Structure-activity relationships for selected sulfur-rich antithrombotic compounds.  

PubMed

We assessed the antithrombotic activity of some simple organosulfur compounds which have some of the functionality found in the disulfide ajoene, a pharmacologically active compound isolated from garlic. The results establish that antithrombotic activity is associated with disulfides directly attached to a phenyl ring and is further enhanced by an alpha-sulfonyl group. CH(3)SO(2)CH(2)SSPh proved to be a potent inhibitor of platelet aggregation with an IC(50) of 5 microM. PMID:10873621

MacDonald, J A; Langler, R F

2000-07-01

241

Structure–Activity Relationships for Selected Sulfur-Rich Antithrombotic Compounds  

Microsoft Academic Search

We assessed the antithrombotic activity of some simple organosulfur compounds which have some of the functionality found in the disulfide ajoene, a pharmacologically active compound isolated from garlic. The results establish that antithrombotic activity is associated with disulfides directly attached to a phenyl ring and is further enhanced by an ?-sulfonyl group. CH3SO2CH2SSPh proved to be a potent inhibitor of

Justin A. MacDonald; Richard F. Langler

2000-01-01

242

Rhodanese Functions as Sulfur Supplier for Key Enzymes in Sulfur Energy Metabolism  

PubMed Central

How microorganisms obtain energy is a challenging topic, and there have been numerous studies on the mechanisms involved. Here, we focus on the energy substrate traffic in the hyperthermophilic bacterium Aquifex aeolicus. This bacterium can use insoluble sulfur as an energy substrate and has an intricate sulfur energy metabolism involving several sulfur-reducing and -oxidizing supercomplexes and enzymes. We demonstrate that the cytoplasmic rhodanese SbdP participates in this sulfur energy metabolism. Rhodaneses are a widespread family of proteins known to transfer sulfur atoms. We show that SbdP has also some unusual characteristics compared with other rhodaneses; it can load a long sulfur chain, and it can interact with more than one partner. Its partners (sulfur reductase and sulfur oxygenase reductase) are key enzymes of the sulfur energy metabolism of A. aeolicus and share the capacity to use long sulfur chains as substrate. We demonstrate a positive effect of SbdP, once loaded with sulfur chains, on sulfur reductase activity, most likely by optimizing substrate uptake. Taken together, these results lead us to propose a physiological role for SbdP as a carrier and sulfur chain donor to these key enzymes, therefore enabling channeling of sulfur substrate in the cell as well as greater efficiency of the sulfur energy metabolism of A. aeolicus. PMID:22496367

Aussignargues, Clément; Giuliani, Marie-Cécile; Infossi, Pascale; Lojou, Elisabeth; Guiral, Marianne; Giudici-Orticoni, Marie-Thérèse; Ilbert, Marianne

2012-01-01

243

A design strategy applied to sulfur resistant lean NOx̳ automotive catalysts  

E-print Network

Catalyst poisoning due to sulfur compounds derived from fuel sulfur presents a major challenge, intractable thus far, to development of many advanced technologies for automotive catalysts such as the lean NOx, trap. Under ...

Tang, Hairong

2005-01-01

244

INDUSTRIAL PROCESS PROFILES FOR ENVIRONMENTAL USE: CHAPTER 23. SULFUR, SULFUR OXIDES AND SULFURIC ACID  

EPA Science Inventory

The catalog of Industrial Process Profiles for Environmental Use was developed as an aid in defining the environmental impacts of industrial activity in the United States. Entries for each industry are in consistent format and form separate chapters of the study. The sulfur indus...

245

Determination of sulfur trioxide in engine exhaust.  

PubMed Central

Sulfur trioxide in the exhaust gas of an internal combustion engine is removed and concentrated by absorption in a solution of 80% isopropyl alcohol, which quantitatively absorbs it and inhibits the oxidation of any sulfur dioxide which may be absorbed. The absorbed sulfur trioxide (sulfuric acid) is determined by an absorption titration by using barium chloride as the titrant and thorin as the indicator. The sulfur dioxide content of the exhaust is measured continuously by means of a DuPont Model 411 ultraviolet photoanalyzer. PMID:50930

Arnold, D R

1975-01-01

246

Separation of sulfur containing chemical warfare related compounds in aqueous samples by micellar electrokinetic chromatography  

Microsoft Academic Search

A method is described in which micellar electrokinetic chromatography (MEKC) is used to separate thiodiglycol, 2,2?-sulfinyldiethanol, 1,4-dithiane, 1,4-thioxane, O-isobutyl methylphosphonothioic acid and O-ethyl methylphosphonothioic acid in aqueous samples. Detection limits range from 1 to 10 ?g\\/ml and the calibration curves are linear over two orders of magnitude. The compounds are separated in under 10 min. The method fulfills our requirements

Richard L. Cheicante; H. Dupont Durst

1995-01-01

247

Hydrodesulfurization of sulfur-containing polyaromatic compounds in light gas oil using noble metal catalysts  

Microsoft Academic Search

We systematically monitored the hydrodesulfurization (HDS) activity of dibenzothiophene (DBT) and groups of substituted DBTs present in a SR-LGO over various noble metal catalysts (Ru, Rh, Ru-Rh, Pt, Pd and Pt-Pd) supported on alumina. The catalytic performances were compared to those obtained over a conventional CoMo catalyst. The Pd-based catalysts exhibited excellent HDS performances, especially for desulfurizing the refractory compounds.

Atsushi Ishihara; Franck Dumeignil; Jeayoung Lee; Kouhei Mitsuhashi; Eika W. Qian; Toshiaki Kabe

2005-01-01

248

Sulfur diagenesis in everglades peat and origin of pyrite in coal  

USGS Publications Warehouse

The pattern of sulfur transformation in peat across the Everglades basin indicates that pyrite formation in organic-rich swamps depends on the use of organic oxysulfur compounds in dissimilatory respiration by sulfur-reducing bacteria. This paragenesis explains the primary distribution of sulfur compounds in low-sulfur coals and possibly in most coals and many organic-rich soils and sediments. It also accounts for the occurrence of framboidal pyrite bound in fossil tissue in coal and sediments.

Altschuler, Z.S.; Schnepfe, M.M.; Silber, C.C.; Simon, F.O.

1983-01-01

249

Sulfur diagenesis in Everglades peat and origin of pyrite in coal  

Microsoft Academic Search

The pattern of sulfur transformation in peat across the Everglades basin indicates that pyrite formation in organic-rich swamps depends on the use of organic oxysulfur compounds in dissimilatory respiration by sulfur-reducing bacteria. This paragenesis explains the primary distribution of sulfur compounds in low-sulfur coals and possibly in most coals and many organic-rich soils and sediments. It also accounts for the

Z. S. Altschuler; M. M. Schnepfe; C. C. Silber; F. O. Simon

1983-01-01

250

Spatial distributions of volatile sulfur compounds in surface seawater and overlying atmosphere in the northwestern Pacific Ocean, eastern Indian Ocean, and Southern Ocean  

NASA Astrophysics Data System (ADS)

Distributions of volatile sulfur compounds (carbonyl sulfide (COS), carbon disulfide (CS2), hydrogen sulfide (H2S), dimethyl sulfide (DMS)) in surface seawater and overlying atmosphere were measured in the northwestern Pacific, eastern Indian, and Southern Oceans (40°N-66°S, 40°E-140°E) in November-December 1996 during the 38th Japanese Antarctic Research Expedition cruise. Seawater measurements revealed that DMS was the dominant sulfur compound, with concentrations of 0.5-15.8 nM. High values were found in the Southern Ocean's marginal ice zone (84°E-63°E, 59°S-63°S), suggesting that the area during the bloom acts as an important source of atmospheric DMS. Atmospheric concentrations were 456-471 pptv for OCS, n.d. (not detected level) -13 pptv for CS2, n.d. -17 pptv for H2S, and n.d. -755 pptv for DMS. Concentrations of OCS were nearly constant. Concentrations of CS2 and H2S were high in terrigenic air masses and low in those of oceanic origin. Comparison of atmospheric DMS data and a steady state box model using sea-to-air fluxes of DMS and assumed OH radical concentrations revealed that atmospheric DMS concentrations in the equatorial region and most of the Southern Ocean were balanced with local oceanic emission residues and photochemical oxidation. Simultaneous measurements in the atmosphere showed DMS was the dominant sulfur gas that was oxidized rapidly to sulfate aerosols in the marine atmosphere.

Inomata, Yayoi; Hayashi, Masahiko; Osada, Kazuo; Iwasaka, Yasunobu

2006-06-01

251

New cysteine-S-conjugate precursors of volatile sulfur compounds in bell peppers (Capsicum annuum L. cultivar).  

PubMed

The objective of this study was to verify whether the volatile organic sulfur compounds recently discovered in bell pepper (Capsicum annuum, L. cultivars), such as the mercapto-ketones: 4-sulfanyl-2-heptanone and 2-sulfanyl-4-heptanone, the mercapto-alcohols: 4-sulfanyl-2-heptanol and 2-sulfanyl-4-heptanol, and heptane-2,4-dithiol, originate from their corresponding cysteine-S-conjugates. Analysis of aqueous extracts of red and green bell pepper by ultraperformance liquid chromatography-mass spectrometry with electrospray ionization in the positive mode (UPLC-MS ESI(+)) displayed masses corresponding to the expected cysteine-S-conjugates. To confirm this observation, four cysteine-S-conjugates were prepared as authentic samples: S-(3-hydroxy-1-methylhexyl)-L-cysteine, S-(3-hydroxy-1-propylbutyl)-L-cysteine, S-(3-oxo-1-propylbutyl)-L-cysteine, and (2R,2'R)-3,3'-(4-hydroxyheptane-2,6-diyl)bis(sulfanediyl) bis(2-aminopropanoic acid). By comparison with the fragmentation patterns and retention times of synthetic mixtures of cysteine-S-conjugate diastereoisomers, the natural occurrence of cysteine conjugates was confirmed in bell peppers. In addition, the cysteine-S-conjugates from red and green bell pepper extracts were concentrated by ion exchange chromatography and the fractions incubated with a ?-lyase (apotryptophanase). The liberated thiols were concentrated by affinity chromatography, and their occurrence, detected by gas chromatography-mass spectrometry, confirmed our predictions. Moreover, 3-sulfanyl-1-hexanol was also detected and the occurrence of S-(1(2-hydroxyethyl)butyl)-L-cysteine confirmed. A quantitative estimation based on external calibration curves, established by UPLC-MS ESI(+) in selected reaction monitoring mode, showed that cysteine-S-conjugates were present at concentrations in the range of 1 to 100 ?g/kg (±20%). PMID:21375341

Starkenmann, Christian; Niclass, Yvan

2011-04-13

252

ROLE OF SULFUR IN REDUCING PCDD AND PCDF FORMATION  

EPA Science Inventory

Past research has suggested that the presence of sulfur (S) in municipal waste combustors (MWCs) can decrease downstream formation of chlorinated organic compounds, particularly polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). Thus, co-firing a...

253

Missing SO2 oxidant in the coastal atmosphere? - Evidence from high resolution measurements of OH and atmospheric sulfur compounds  

NASA Astrophysics Data System (ADS)

Diurnal and seasonal variations of gaseous sulfuric acid (H2SO4) and methane sulfonic acid (MSA) were measured in N.E. Atlantic air at the Mace Head atmospheric research station during the years 2010 and 2011. The measurements utilized selected ion/chemical ionization mass spectrometry (SI/CIMS) with a detection limit for both compounds of 4.3 × 10 4 cm-3 at 5 min signal integration. The H2SO4 and MSA gas-phase concentrations were analysed in conjunction with the condensational sink for both compounds derived from 3 nm-10 ?m (diameter) aerosol size distributions. Accommodation coefficients of 1.0 for H2SO4 and 0.12 for MSA were assumed leading to estimated atmospheric lifetimes of the order of 7 min and 25 min, respectively. With the SI/CIMS instrument in OH measurement mode alternating between OH signal and background (non-OH) signal evidence was obtained for the presence of one or more unknown oxidants of SO2 in addition to OH. Depending on the nature of the oxidant(s) their ambient concentration may be enhanced in the CIMS inlet system by additional production. The apparent unknown SO2 oxidant was additionally confirmed by direct measurements of SO2 in conjunction with calculated H2SO4 concentrations. The calculated concentrations were consistently lower than the measured concentrations by a factor 4.8 ± 3.4 when considering the oxidation of SO2 by OH as the only source of H2SO4. Both the OH and the background signal were also observed to increase significantly during daytime aerosol nucleation events, independent of the ozone photolysis frequency, J(O1D), and were followed by peaks in both H2SO4 and MSA concentrations. This suggests a strong relation between the unknown oxidant(s), OH chemistry, and the atmospheric photo-oxidation of biogenic iodine compounds. As to the identity of the oxidant(s), we have been able to exclude ClO, BrO, IO, and OIO as possible candidates based on ab initio calculations. Stabilized Criegee intermediates (sCI) produced from ozonolysis of alkenes potentially contribute to the oxidation efficiency of the coastal and marine atmosphere. However, analysis of the CIMS background signal in context with recently published kinetic data currently suggests that larger Criegee intermediates produced from ozonolysis play no significant role for SO2 oxidation in the marine atmosphere. The possibility of H2SO4 formation without SO2 as precursor or from SO2 oxidation by small sCI produced photolytically should be explored.

Berresheim, H.; Adam, M.; Monahan, C.; O'Dowd, C.; Plane, J. M. C.; Bohn, B.; Rohrer, F.

2014-01-01

254

Metal-sulfur type cell having improved positive electrode  

DOEpatents

An novel metal-sulfur type cell operable at a temperature of 200.degree. C. or less with an energy density of 150 Whrs/Kg or better is disclosed characterized by an organo-sulfur cathode formed from an organic-sulfur compound having the general formula, in its charged state, of (R(S).sub.y).sub.n wherein y=1 to 6; n=2 to 20; and R is one or more different aliphatic or aromatic organic moieties having 1 to 20 carbon atoms, which may include one or more oxygen, sulfur, or nitrogen heteroatoms when R comprisises one of more aromatic rings, or one or more oxygen, sulfur, nitrogen, or fluorine atoms associtated with the chain when R comprises an aliphatic chain, wherein the aliphatic group may be linear or branched, saturated or unsaturated, and wherein either the aliphatic chain or the aromatic ring may have substituted groups thereon.

Dejonghe, Lutgard C. (Berkeley, CA); Visco, Steven J. (Berkeley, CA); Mailhe, Catherine C. (Berkeley, CA); Armand, Michel B. (St. Martin D'Uriage, FR)

1989-01-01

255

Metal-sulfur type cell having improved positive electrode  

DOEpatents

A novel metal-sulfur type cell operable at a temperature of 200/degree/C or less with an energy density of 150 Whrs/Kg or better is disclosed characterized by an organo-sulfur cathode formed from an organic-sulfur compound having the general formula, in its charged state, of (R(S)/sub y/)n wherein y = 1 to 6; n = 2 to 20; and R is one or more different aliphatic or aromatic organic moieties having 1 to 20 carbon atoms, which may include one or more oxygen, sulfur, or nitrogen heteroatoms when R comprises one or more aromatic rings, or one or more oxygen, sulfur, nitrogen, or fluorine atoms associated with the chain when R comprises an aliphatic chain, wherein the aliphatic group may be linear or branched, saturated or unsaturated, and wherein either the aliphatic chain or the aromatic ring may have substituted groups thereon. 4 figs.

DeJonghe, L.C.; Visco, S.J.; Mailhe, C.C.; Armand, M.B.

1988-03-31

256

Thermodynamic Properties of Sulfur Hexafluoride  

Microsoft Academic Search

We present new vapor phase speed-of-sound data u(P, T), new Burnett density–pressure–temperature data ?(P, T), and a few vapor pressure measurements for sulfur hexafluoride (SF6). The speed-of-sound data spanned the temperature range 230 K=T=460 K and reached maximum pressures that were the lesser of 1.5 MPa or 80% of the vapor pressure of SF6. The Burnett ?(P, T) data were obtained on isochores

J. J. Hurly; D. R. Defibaugh; M. R. Moldover

2000-01-01

257

Wet scavenging of sulfur compounds and other constituents during the Indian Ocean Experiment (INDOEX)  

NASA Astrophysics Data System (ADS)

Rainwater samples for chemical analysis were collected over the Indian Ocean during the Indian Ocean Experiment (INDOEX) campaign January-March 1999 on board the research vessels Ronald H. Brown and Sagar Kanya. Samples were analyzed for major ions and some trace metals. The rainwater data are interpreted in terms of transport from potential source regions in Asia using air mass trajectories covering 10 days. A comparison is also made between the rainwater data and the concentration of aerosol components measured simultaneously on the ships. The concentrations of nonsea-salt (nss)-SO42-, NO3-, NH4+, nss-K+, and nss-Ca2+ in rainwater over the Indian Ocean, while a factor of 2 to 3 lower than over the Indian continent, were still clearly influenced by pollution and soil sources in Asia. The concentration of nss-Ca2+ decreased more rapidly as the air moved southward from the continent out over the ocean, whereas the concentration of nss-SO42- became relatively more abundant. This was consistent with the observed higher acidity of the rainwater over the ocean (pH in the range 4.8 to 5.4) than over the Indian subcontinent, with NH4+ as the main cation (rather than Ca2+, as over land). Variations in the concentration of Al and Fe correlated well with those of nss-Ca2+, indicating a crustal source for these elements. The relation between Na+, Cl-, and Br- in the rainwater was close to that of seawater, implying no excess or deficit of the two halogen ions. The ratio between the concentration in rainwater and the concentration in surface air was systematically larger for aerosol components that exist in the coarse mode of sea-salt origin (Na+, Mg2+, and Cl-) than those in the fine mode (NH4+, nss-K+, and nss-SO42-), indicating that fine-mode particles are scavenged mainly by in-cloud processes whereas coarse-mode sea-salt particles are scavenged also by falling raindrops under the clouds. Nss-Ca2+ and NO3- fall in a category in between, indicating that these compounds are not as effectively removed by below-cloud scavenging as sea-salt aerosols.

Granat, L.; Norman, M.; Leck, C.; Kulshrestha, U. C.; Rodhe, H.

2002-10-01

258

Comparative Aspects of Sulfur Mineralization in Sediments of a Eutrophic Lake Basin †  

PubMed Central

The net mineralization of organic sulfur compounds in surface sediments of Wintergreen Lake was estimated from a mass-balance budget of sulfur inputs and sediment sulfur concentrations. The net mineralization of organic sulfur inputs is <50% complete, which is consistent with the dominance of organic sulfur (>80% of total sulfur) in sediment. Although sediment sulfur is predominantly organic, sulfate reduction is the most significant process in terms of the quantities of sulfur transformed in surface sediments. Rates of sulfate reduction in these sediments average 7 mmol/m2 per day. On an annual basis, this rate is 19-fold greater than net rates of organic sulfur mineralization and 65-fold greater than sulfate ester hydrolysis. PMID:16346037

King, Gary M.; Klug, M. J.

1982-01-01

259

Electron capture sulfur detector: reduced sulfur species detection at the femtomole level  

SciTech Connect

The authors have developed a new technique to detect reduced sulfur compounds by fluorination with F/sub 2/ (at 200 ppm) on a heated Ag catalyst after GC separation. The excess F/sub 2/ is removed by conversion to HF by reaction with H/sub 2/ on a heated Pd catalysts. The fluorination product, presumably SF/sub 6/, is then detected in an electron capture detector (ECD). The Pd catalyst also destroys the response from halocarbons making the system sulfur specific. This ECD sulfur detector has a calculated minimum detectable level (MDL) for H/sub 2/S, OCS, CH/sub 3/SH, DMS, and CS/sub 2/ of less than 2 fmol/s for each compound, 2 orders of magnitude lower than the best FPD systems. The ratio of the detected molar response of each of these sulfur compounds to the molar response of SF/sub 6/ ranges from 2% to 20% and increases with increasing AgF/sub 2/ temperature.

Johnson, J.E.; Lovelock, J.E.

1988-04-15

260

Biotic and abiotic carbon to sulfur bond cleavage. Final report  

SciTech Connect

The microbial desulfurization of organosulfur compounds occurs by unprecedented and largely unexplored biochemical processes. A study of such biotic desulfurizations can be expected to give rise to new and useful chemistry and enzymology. The potential value of understanding and harnessing these processes is seen in relation to the need for methods for the removal of organically bound sulfur from coal and the degradation of organic sulfur-containing pollutants. This research effort has been directed towards an examination of desulfurization ability in well characterized microorganisms, the isolation of bacteria with desulfurization ability from natural sources, the characterization and mechanistic evaluation of the observed biocatalytic processes, the development of biomimetic synthetic organic chemistry based on biotic desulfurization mechanisms and the design and preparation of improved coal model compounds for use in microbial selection processes. A systematic approach to studying biodesulfurizations was undertaken in which organosulfur compounds have been broken down into classes based on the oxidation state of the sulfur atom and the structure of the rest of the organic material. Microbes have been evaluated in terms of ability to degrade organosulfur compounds with sulfur in its sulfonic acid oxidation state. These compounds are likely intermediates in coal desulfurization and are present in the environment as persistent pollutants in the form of detergents. It is known that oxygen bonded to sulfur lowers the carbon-sulfur bond energy, providing a thermodynamic basis for starting with this class of compounds.

Frost, J.W.

1994-05-01

261

Analytical method for the evaluation of sulfur functionalities in American coals. Final report  

SciTech Connect

This investigation consisted of the following 6 tasks: (1) improve the instrumentation for the sulfur functional groups analysis and make it more reliable. (2) create a set of reference standards of sulfur-containing compounds. (3) examine the sulfur groups distribution in untreated and desulfurized coals. (4) examine the sulfur functionalities in raw and processed coals, i.e., liquefied coals. (5) determine the distribution of sulfur functionalities in modified coals. (6) prepare computer programs for calculations related to the distribution of sulfur functional groups in coal. Each task is discussed and results are presented. Appendix A contains the computer program used to interpret the data. 31 references, 56 figures, 17 tables.

Attar, A.

1983-05-01

262

Predictive sulfur metabolism – a field in flux  

PubMed Central

The key role of sulfur metabolites in response to biotic and abiotic stress in plants, as well as their importance in diet and health has led to a significant interest and effort in trying to understand and manipulate the production of relevant compounds. Metabolic engineering utilizes a set of theoretical tools to help rationally design modifications that enhance the production of a desired metabolite. Such approaches have proven their value in bacterial systems, however, the paucity of success stories to date in plants, suggests that challenges remain. Here, we review the most commonly used methods for understanding metabolic flux, focusing on the sulfur assimilatory pathway. We highlight known issues with both experimental and theoretical approaches, as well as presenting recent methods for integrating different modeling strategies, and progress toward an understanding of flux at the whole plant level. PMID:25477892

Calderwood, Alexander; Morris, Richard J.; Kopriva, Stanislav

2014-01-01

263

SEMI-BATCH PRECIPITATION OF CALCIUM SULFATE DIHYDRATE FROM CALCITE AND SULFURIC ACID  

E-print Network

SEMI-BATCH PRECIPITATION OF CALCIUM SULFATE DIHYDRATE FROM CALCITE AND SULFURIC ACID Frédéric BARD1 a calcite suspension to a sulfuric acid solution from industrial waste. The morphology of the precipitated, sulfuric acid, industrial waste. 1. INTRODUCTION Gypsum is a mineral compound of first importance

Paris-Sud XI, Université de

264

Prebiotic Synthesis of Methionine and Other Sulfur-Containing Organic Compounds on the Primitive Earth: A Contemporary Reassessment Based on an Unpublished 1958 Stanley Miller Experiment  

NASA Technical Reports Server (NTRS)

Original extracts from an unpublished 1958 experiment conducted by the late Stanley L. Miller were recently found and analyzed using modern state-of-the-art analytical methods. The extracts were produced by the action of an electric discharge on a mixture of methane (CH4), hydrogen sulfide (H2S), ammonia (NH3), and carbon dioxide (CO2). Racemic methionine was farmed in significant yields, together with other sulfur-bearing organic compounds. The formation of methionine and other compounds from a model prebiotic atmosphere that contained H2S suggests that this type of synthesis is robust under reducing conditions, which may have existed either in the global primitive atmosphere or in localized volcanic environments on the early Earth. The presence of a wide array of sulfur-containing organic compounds produced by the decomposition of methionine and cysteine indicates that in addition to abiotic synthetic processes, degradation of organic compounds on the primordial Earth could have been important in diversifying the inventory of molecules of biochemical significance not readily formed from other abiotic reactions, or derived from extraterrestrial delivery.

Parker, Eric T.; Cleaves, H. James; Callahan, Michael P.; Dworkin, Jason P.; Glavin, Daniel P.; Lazcano, Antonio

2010-01-01

265

Ceramic-metal seals for advanced battery systems. [sodium sulfur and lithium sulfur batteries  

NASA Technical Reports Server (NTRS)

The search for materials which are electrochemically compatible with the lithium sulfur and sodium sulfur systems is discussed. The use liquid or braze alloys, titanium hydrite coatings, and tungsten yttria for bonding beryllium with ceramic is examined.

Reed, L.

1978-01-01

266

The use of sulfur in dermatology.  

PubMed

Sulfur has antifungal, antibacterial, and keratolytic activity. In the past, its use was widespread in dermatological disorders such as acne vulgaris, rosacea, seborrheic dermatitis, dandruff, pityriasis versicolor, scabies, and warts. Adverse events associated with topically applied sulfur are rare and mainly involve mild application site reactions. Sulfur, used alone or in combination with agents such as sodium sulfacetamide or salicylic acid, has demonstrated efficacy in the treatment of many dermatological conditions. PMID:15303787

Gupta, Aditya K; Nicol, Karyn

2004-01-01

267

HYDROCARBON AND SULFUR SENSORS FOR SOFC SYSTEMS  

SciTech Connect

The following report summarizes work conducted during the Phase I program Hydrocarbon and Sulfur Sensors for SOFC Systems under contract No. DE-FC26-02NT41576. For the SOFC application, sensors are required to monitor hydrocarbons and sulfur in order to increase the operation life of SOFC components. This report discusses the development of two such sensors, one based on thick film approach for sulfur monitoring and the second galvanic based for hydrocarbon monitoring.

A.M. Azad; Chris Holt; Todd Lesousky; Scott Swartz

2003-11-01

268

Sulfur Chemistry in Bacterial Leaching of Pyrite  

Microsoft Academic Search

In the case of pyrite bioleaching byLeptospirillum ferrooxidans, an organism without sulfur-oxidizing capac- ity, besides the production of tetra- and pentathionate, a considerable accumulation of elemental sulfur occurred. A similar result was obtained for chemical oxidation assays with acidic, sterile iron(III) ion- containing solutions. In the case of Thiobacillus ferrooxidans, only slight amounts of elemental sulfur were detectablebecauseoftheorganism'scapacitytooxidizesulfurcompounds.Inthecourseofoxidative,chemical pyrite degradation

AXEL SCHIPPERS; PETER-GEORG JOZSA

1996-01-01

269

Sulfur and Hydrogen Isotope Anomalies in Meteorite Sulfonic Acids  

NASA Technical Reports Server (NTRS)

Intramolecular carbon, hydrogen, and sulfur isotope ratios were measured on a homologous series of organic sulfonic acids discovered in the Murchison meteorite. Mass-independent sulfur isotope fractionations were observed along with high deuterium/hydrogen ratios. The deuterium enrichments indicate formation of the hydrocarbon portion of these compounds in a low-temperature environment that is consistent with that of interstellar clouds. Sulfur-33 enrichments observed in methanesulfonic acid could have resulted from gas-phase ultraviolet irradiation of a precursor, carbon disulfide. The source of the sulfonic acid precursors may have been the reactive interstellar molecule carbon monosulfide.

Cooper, George W.; Thiemens, Mark H.; Jackson, Teresa L.; Chang, Sherwood

1997-01-01

270

Are the clouds of Venus sulfuric acid.  

NASA Technical Reports Server (NTRS)

It is shown that strong aqueous sulfuric acid solutions have the right refractive index and freeze at Venusian cloud temperature, explain the dryness of the Venusian stratosphere, are consistent with some features of the Venusian IR spectrum, and do not absorb in highly reflecting areas of Venus. It is also indicated that such solutions should be produced by reactions between known atmospheric constituents and most sulfur-bearing rock at the Venusian surface temperature, and require only small amounts of sulfur consistent with its cosmic abundance and with the amounts of other volatile elements present in the atmosphere. It is believed therefore that the clouds of Venus consist of sulfuric acid solutions.

Young, A. T.

1973-01-01

271

Elemental sulfur in Eddy County, New Mexico  

USGS Publications Warehouse

Sulfur has been reported in Eddy County, N. Mex., in rocks ranging from Silurian to Holocene in age at depths of 0-15,020 feet. Targets of present exploration are Permian formations in the Delaware Basin and northwest shelf areas at depths of less than 4,000 feet. Most of the reported sulfur occurrences in the shelf area are in the 'Abo' (as used by some subsurface geologists), Yeso, and San Andres Formations and the Artesia Group. Sulfur deposition in the dense dolomites of the 'Abo,' Yeso, and San Andres Formations is attributed to the reduction of ionic sulfate by hydrogen sulfide in formation waters in zones of preexisting porosity and permeability. A similar origin accounts for most of the sulfur deposits in the formations of the Artesia Group, but some of the sulfur in these formations may have originated in place through the alteration of anhydrite to carbonate and sulfur by the metabolic processes of bacteria in the presence of hydrocarbons. Exploration in the Delaware Basin area is directed primarily toward the Castile Formation. Sulfur deposits in the Castile Formation are found in irregular masses of cavernous brecciated secondary carbonate rock enveloped by impermeable anhydrite. The carbonate masses, or 'castiles,' probably originated as collapse features resulting from subsurface solution and upward stopping. Formation of carbonate rock and sulfur in the castiles is attributed to the reduction of brecciated anhydrite by bacteria and hydrocarbons in the same process ascribed to the formation of carbonate and sulfur in the caprocks of salt domes.

Hinds, Jim S.; Cunningham, Richard R.

1970-01-01

272

Prediction Model of Sulfur Deposition in the High Sulfur Gas Well Bore  

Microsoft Academic Search

Sulfur deposition in the well bore not only jams the equipment and pipeline, but also gets heavy corrosion of down-hole’s\\u000a pipe string and rig on ground. The accurate prediction of sulfur deposition in the well bore is very important. Because sulfur\\u000a solubility is a function of temperature and pressure in the high sulfur gas well bore, this paper addressed solubility

Chun-bi Xu; Jiong Wang; Shun-peng Zeng

273

Sulfuric Acid Production on Europa: The Radiolysis of Sulfur in Water Ice  

Microsoft Academic Search

Europa's surface is chemically altered by radiolysis from energetic charged particle bombardment. It has been suggested that hydrated sulfuric acid (H2SO4·nH2O) is a major surface species and is part of a radiolytic sulfur cycle, where a dynamic equilibrium exists between continuous production and destruction of sulfur polymers Sx, sulfur dioxide SO2, hydrogen sulfide H2S, and H2SO4·nH2O. We measured the rate

R. W. Carlson; M. S. Anderson; R. E. Johnson; M. B. Schulman; A. H. Yavrouian

2002-01-01

274

Sulfuric Acid Production on Europa: The Radiolysis of Sulfur in Water Ice  

Microsoft Academic Search

Europa's surface is chemically altered by radiolysis from energetic charged particle bombardment. It has been suggested that hydrated sulfuric acid (H2SO4.nH2O) is a major surface species and is part of a radiolytic sulfur cycle, where a dynamic equilibrium exists between continuous production and destruction of sulfur polymers Sx, sulfur dioxide SO2, hydrogen sulfide H2S, and H2SO4.nH2O. We measured the rate

R. W. Carlson; M. S. Anderson; R. E. Johnson; M. B. Schulman; A. H. Yavrouian

2002-01-01

275

Heat Transfer Characteristics of Sulfur and Sulfur Diluted with Hydrogen Sulfide Flowing Through Circular Tubes  

E-print Network

diluted with H2S, added as persulfide. Viscosity of sulfur diluted with H2S, added as liquid. . . 50 51 Viscosity of liquid sulfur 52 Characteristics of sulfur-density and thermal conductivity. . . . 53 Heat capacity of sulfur 54 Characteristics... from a reactor. It has a high heat capacity and excellent heat transfer characteris- tics, and does not require special corrosion-resistant system components. Its nuclear properties are also favorable. It is not subject to destructive or hazardous...

Stone, Porter Walwyn

2012-06-07

276

Development of the Hybrid Sulfur Thermochemical Cycle  

SciTech Connect

The production of hydrogen via the thermochemical splitting of water is being considered as a primary means for utilizing the heat from advanced nuclear reactors to provide fuel for a hydrogen economy. The Hybrid Sulfur (HyS) Process is one of the baseline candidates identified by the U.S. Department of Energy [1] for this purpose. The HyS Process is a two-step hybrid thermochemical cycle that only involves sulfur, oxygen and hydrogen compounds. Recent work has resulted in an improved process design with a calculated overall thermal efficiency (nuclear heat to hydrogen, higher heating value basis) approaching 50%. Economic analyses indicate that a nuclear hydrogen plant employing the HyS Process in conjunction with an advanced gas-cooled nuclear reactor system can produce hydrogen at competitive prices. Experimental work has begun on the sulfur dioxide depolarized electrolyzer, the major developmental component in the cycle. Proof-of-concept tests have established proton-exchange-membrane cells (a state-of-the-art technology) as a viable approach for conducting this reaction. This is expected to lead to more efficient and economical cell designs than were previously available. Considerable development and scale-up issues remain to be resolved, but the development of a viable commercial-scale HyS Process should be feasible in time to meet the commercialization schedule for Generation IV gas-cooled nuclear reactors.

Summers, William A.; Steimke, John L

2005-09-23

277

Multiple sulfur isotope constraints on the modern sulfur cycle  

NASA Astrophysics Data System (ADS)

We present 28 multiple sulfur isotope measurements of seawater sulfate (?34S and ?33S) from the modern ocean over a range of water depths and sites along the eastern margin of the Pacific Ocean. The average measured ?34S is 21.24‰ (±0.88‰,2?) with a calculated ?33S of +0.050‰ (±0.014‰,2?). With these values, we use a box-model to place constraints on the gross fraction of pyrite burial in modern sediments. This model presents an improvement on previous estimates of the global pyrite burial flux because it does not rely on the assumed value of ?34S, which is poorly constrained, but instead uses new information about the relationship between ?34S and ?33S in global marine sulfate. Our calculations indicate that the pyrite burial flux from the modern ocean is between 10% and 45% of the total sulfur lost from the oceans, with a more probable range between 20% and 35%.

Tostevin, Rosalie; Turchyn, Alexandra V.; Farquhar, James; Johnston, David T.; Eldridge, Daniel L.; Bishop, James K. B.; McIlvin, Matthew

2014-06-01

278

Coexistence Curve of Sulfur Hexafluoride  

Microsoft Academic Search

The coexistence curve of sulfur hexafluoride has been determined by interferometric measurements for the temperature range 10-5<(Tc-T)Tc<10-1. The refractive index difference nl-nv is fitted by a power law. The difference Deltan is proportional to (DeltaT)beta, where beta=0.346+\\/-0.001 for the temperature range 10-2<(Tc-T)Tc<10-1. The exponent beta decreases to 0.339 +\\/- 0.003 as (Tc-T)Tc decreases to the lower limit of the data

D. Balzarini; K. Ohrn

1972-01-01

279

Catalytic oxidation of sulfur dioxide  

SciTech Connect

A review of the vanadium-catalyzed sulfur dioxide oxidation at 400/sup 0/C (ignition point) to 620/sup 0/C (thermal deactivation point) and 6-12% initial SO/sub 2/ concentration covers the vanadium catalyst composition and properties; the reaction mechanism; 29 kinetic equations, their range of applicability, and their inadequacy as general rate equations; intraparticle mass and heat transfer studies; experimental methods for determining the global reaction rate; and reactor design, including mathematical modeling and optimization of adiabatic, nonadiabatic, and nonideal adiabatic beds.

Urbanek, A. (Warsaw Tech. Univ.); Trela, M.

1980-01-01

280

Economic comparison of hydrogen production using sulfuric acid electrolysis and sulfur cycle water decomposition. Final report  

Microsoft Academic Search

An evaluation of the relative economics of hydrogen production using two advanced techniques was performed. The hydrogen production systems considered were the Westinghouse Sulfur Cycle Water Decomposition System and a water electrolysis system employing a sulfuric acid electrolyte. The former is a hybrid system in which hydrogen is produced in an electrolyzer which uses sulfur dioxide to depolarize the anode.

G. H. Farbman; B. R. Krasicki; C. C. Hardman; S. S. Lin; G. H. Parker

1978-01-01

281

Binding mechanism of sulfur and dehydrogenated polyacrylonitrile in sulfur/polymer composite cathode  

NASA Astrophysics Data System (ADS)

A composite consisting of sulfur/dehydrogenated polyacrylonitrile is one of the most promising cathode materials for use in rechargeable lithium-sulfur batteries. However, the reported sulfur contents have been low, less than 50 wt%, which compromise the intrinsic high specific capacity and energy of elemental sulfur and hence decrease significantly the specific energy of the composite. To identify the potential to further increase the sulfur content, we elucidate the binding mechanism of sulfur and polyacrylonitrile in their composite. The heat treatment experiments at varying timespans with excess sulfur showed a constancy of sulfur content after a critical length of timespan, indicating the saturation of sulfur in the structure of dehydrogenated polyacrylonitrile. Based on molecular structure and size consideration, it is proposed that the binding involves the formation of an 8 membered ring of sulfur embedded between 4 heterocyclic rings of dehydrogenated polyacrylonitrile. From this model and experimental results, we show that there exists an upper limit of sulfur content in the sulfur/dehydrogenated polyacrylonitrile composite at 56 wt%.

Doan, The Nam Long; Ghaznavi, Mahmoudreza; Zhao, Yan; Zhang, Yongguang; Konarov, Aishuak; Sadhu, Mikhail; Tangirala, Ravichandra; Chen, P.

2013-11-01

282

An integrated sulfur isotope model for Namibian shelf sediments  

Microsoft Academic Search

In this study the sulfur cycle in the organic-rich mud belt underlying the highly productive upwelling waters of the Namibian shelf is quantified using a 1D reaction-transport model. The model calculates vertical concentration and reaction rate profiles in the top 500cm of sediment which are compared to a comprehensive dataset which includes carbon, sulfur, nitrogen and iron compounds as well

Andrew W. Dale; Volker Brüchert; Marc Alperin; Pierre Regnier

2009-01-01

283

Graphene-wrapped sulfur nanospheres with ultra-high sulfur loading for high energy density lithium-sulfur batteries  

NASA Astrophysics Data System (ADS)

Lithium-sulfur (Li-S) battery with high theoretical energy density is one of the most promising energy storage systems for electric vehicles and intermittent renewable energy. However, due to the poor conductivity of the active material, considerable weight of the electrode is occupied by the conductive additives. Here we report a graphene-wrapped sulfur nanospheres composite (S-nanosphere@G) with sulfur content up to 91 wt% as the high energy density cathode material for Li-S battery. The sulfur nanospheres with diameter of 400-500 nm are synthesized through a solution-based approach with the existence of polyvinylpyrrolidone (PVP). Then the sulfur nanospheres are uniformly wrapped by conductive graphene sheets through the electrostatic interaction between graphene oxide and PVP, followed by reducing of graphene oxide with hydrazine. The design of graphene wrapped sulfur nanoarchitecture provides flexible conductive graphene coating with void space to accommodate the volume expansion of sulfur and to minimize polysulfide dissolution. As a result, the S-nanosphere@G nanocomposite with 91 wt% sulfur shows a reversible initial capacity of 970 mA h g-1 and an average columbic efficiency > 96% over 100 cycles at a rate of 0.2 C. Taking the total mass of electrode into account, the S-nanosphere@G composite is a promising cathode material for high energy density Li-S batteries.

Liu, Ya; Guo, Jinxin; Zhang, Jun; Su, Qingmei; Du, Gaohui

2015-01-01

284

40 CFR 52.231 - Regulations: Sulfur oxides.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Regulations: Sulfur oxides. 52.231 Section 52.231 Protection...California § 52.231 Regulations: Sulfur oxides. (a) [Reserved] (b...Ambient Air Quality Standard for Sulfur Oxides. (1) Lake County Intrastate...

2013-07-01

285

40 CFR 52.231 - Regulations: Sulfur oxides.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Regulations: Sulfur oxides. 52.231 Section 52.231 Protection...California § 52.231 Regulations: Sulfur oxides. (a) [Reserved] (b...Ambient Air Quality Standard for Sulfur Oxides. (1) Lake County Intrastate...

2012-07-01

286

40 CFR 52.231 - Regulations: Sulfur oxides.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Regulations: Sulfur oxides. 52.231 Section 52.231 Protection...California § 52.231 Regulations: Sulfur oxides. (a) [Reserved] (b...Ambient Air Quality Standard for Sulfur Oxides. (1) Lake County Intrastate...

2010-07-01

287

A study of volatile organic sulfur emissions causing urban odors.  

PubMed

Levels of hydrogen sulfide and sulfur containing organic compounds were studied in the air at the deltas of the polluted creeks in the city of Izmir, Turkey in summer 2001. High concentrations of these malodorous compounds were measured in the air samples. Presence of these compounds in the air was connected with the dark appearance and rising gas bubbles in the studied segments of the creeks. These creeks were like open sewers carrying wastewaters from the industry and residential areas into the inner Izmir Bay until September 2001. Within the scope of this study organic sulfur compounds such as methane thiol, ethane thiol, 2-propane thiol, 2-butane thiol, dimethylsulfide, dimethyldisulfide, thiophene, diphenylsulfide and hydrogen sulfide were studied in the air at selected urban sites where odor nuisance was recognized. Flux measurements from polluted surfaces were preferred rather than direct ambient air measurements. Organic sulfur emission fluxes from the creek surfaces were found above the values reported in the literature. Their concentrations and fluxes were higher in June field program. A limited number of measurements of reduced sulfur compound emission concentrations from the wastewater treatment plant equalization tank and the sludge drying beds as well as the landfill soil surface were also included in the study. Concentrations of total organic sulfur compounds and certain individual components such as dimethylsulfide and hydrogen sulfide in emitted gases from river surfaces were correlated with ambient SO(2) concentrations. PMID:12604076

Muezzinoglu, Aysen

2003-04-01

288

Dielectric strength of sulfur hexafluoride upon condensation  

SciTech Connect

The behavior of sulfur hexafluoride in a sealed high-voltage device has been modeled for cooling to the condensation point of the insulating medium. The temperature dependences of the breakdown voltages of sulfur hexafluoride have been investigated for several interelectrode separations. The dielectric strength has been shown to decrease upon condensation with formation of a bridge of boiling liquid phase between the electrodes.

Antonov, A.V.; Lyapin, A.G.; Popkov, V.I.

1983-01-01

289

Microbial Architecture of Environmental Sulfur Processes: A  

E-print Network

potential impacts on water quality, including acid generation in acid mine drainage (AMD) environments, 2009. Accepted July 9, 2009. Microbial oxidation of sulfur-rich mining waste materials drives acid mine drainage (AMD) and affects the global sulfur biogeochemical cycle. The generation of AMD is a complex

Hitchcock, Adam P.

290

An Aerosol Condensation Model for Sulfur Trioxide  

Microsoft Academic Search

This document describes a model for condensation of sulfuric acid aerosol given an initial concentration and\\/or source of gaseous sulfur trioxide (e.g. fuming from oleum). The model includes the thermochemical effects on aerosol condensation and air parcel buoyancy. Condensation is assumed to occur heterogeneously onto a preexisting background aerosol distribution. The model development is both a revisiting of research initially

2008-01-01

291

Sulfur diagnostic criteria for French prune trees  

Microsoft Academic Search

One year old Marianna 2624 (Prunus cerasifera X P. munsoniana) trees grafted with French prunes (P. domestica) were grown in the greenhouse in pots containing vermiculite and supplied with graded amounts of sulfate?sulfur (SO4?S) to study the methods of evaluating sulfur (S). Tree fresh weight gain was recorded. Leaf samples were analyzed for different S fractions. Chlorophyll concentration of leaves

Izhar Ul Haq; Robert M. Carlson

1993-01-01

292

Leaching behavior of ilmenite with sulfuric acid  

Microsoft Academic Search

A study of the rate of dissolution of ilmenite in sulfuric acid solutions has been carried out. The effects of temperature, particle size, stirring speed, and concentration of sulfuric acid on the rate of dissolution of ilmenite has been investigated. Temperature range studied in this investigation was 88° to 115°C, and the Arrhenius activation energy was found to be 64.4

K. N. Han; T. Rubcumintara; M. C. Fuerstenau

1987-01-01

293

The Microbial Karst Sulfuric Acid Dynamo  

Microsoft Academic Search

The original model for sulfuric acid speleogenesis attributes limestone dissolution to the oxidation of gaseous H2S to sulfuric acid on limestone cave walls (Egemeier 1981). This model has recently been reexamined in Lower Kane Cave, Wyoming (USA), where the most intense limestone dissolution appears to be the result of microbial colonization of limestone surfaces below the water table (Engel et

E. Lyon; K. Meyer; B. Koffman; S. Galdenzi; J. Macalady

2004-01-01

294

Sulfuric Acid and Water: Paradoxes of Dilution  

ERIC Educational Resources Information Center

On equilibrium properties of aqueous solutions of sulfuric acid, Julius Thomsen has marked that the heat evolved on diluting liquid sulfuric acid with water is a continuous function of the water used, and excluded absolutely the acceptance of definite hydrates as existing in the solution. Information about thermochemical measurement, a discussion…

Leenson, I. A.

2004-01-01

295

SURFACE REACTIONS OF OXIDES OF SULFUR  

EPA Science Inventory

Surface reactions of several sulfur-containing molecules have been studied in order to understand the mechanism by which sulfate ions are formed on atmospheric aerosols. At 25C the heterogeneous oxidation of SO2 by NO2 to sulfuric acid and sulfate ions occurred on hydrated silica...

296

Heat pipes for sodium-sulfur batteries  

Microsoft Academic Search

The objective of this program was to develop a variable conductance heat pipe (VCHP) for the thermal management of sodium-sulfur batteries. The VCHP maintains the sodium sulfur battery within a specified temperature rise limit (20 C) while the battery discharges a thermal load from 0 watts to 500 watts. A preliminary full scale thermal management design was developed for the

John R. Hartenstine

1989-01-01

297

Estimation of sulfur deposition in South Korea  

Microsoft Academic Search

Dry and wet depositions of sulfur have been estimated using the routinely available meteorological data at 70 sites, air-monitored data at 27 sites and upper air soundings made daily twice (0000 and 1200 UTC) at three stations over South Korea for 4yr from 1994 to 1997. The average annual total dry deposition and wet deposition of sulfur in South Korea

Soon-Ung Park; Hee-Jin In; Si-Wan Kim; Young-Hee Lee

2000-01-01

298

Drug Targets in Mycobacterial Sulfur Metabolism  

PubMed Central

The identification of new antibacterial targets is urgently needed to address multidrug resistant and latent tuberculosis infection. Sulfur metabolic pathways are essential for survival and the expression of virulence in many pathogenic bacteria, including Mycobacterium tuberculosis. In addition, microbial sulfur metabolic pathways are largely absent in humans and therefore, represent unique targets for therapeutic intervention. In this review, we summarize our current understanding of the enzymes associated with the production of sulfated and reduced sulfur-containing metabolites in Mycobacteria. Small molecule inhibitors of these catalysts represent valuable chemical tools that can be used to investigate the role of sulfur metabolism throughout the Mycobacterial lifecycle and may also represent new leads for drug development. In this light, we also summarize recent progress in the development of inhibitors of sulfur metabolism enzymes. PMID:17970225

Bhave, Devayani P.; Muse, Wilson B.; Carroll, Kate S.

2011-01-01

299

Sulfur species in volcanic gases.  

PubMed

A new analytical method for the determination of the sulfur species (SO2, H2S, S8(0)) in volcanic gases is proposed by revising, updating, and improving previous methods. The most significant advantages of the proposed procedure can briefly be summarized, as follows: (i) the reaction among sulfur species stops during the gas sampling by using preevacuated thorion-tapped vials with purified 0.15M Cd(OH)2 in 4 M NaOH to favor the precipitation of H2S as CdS; (ii) all the sulfur species (SO2, H2S, S8(0)) are analyzed by ion chromatography, after conversion to SO4, which allows the detection limit to be lowered significantly with respect to the previous studies; (iii) appropriate aliquots from intermediate steps may be used to determine other species commonly present in volcanic gases such as CO2, HCI, HF, HBr, HI, and so forth; (iv) determination of all the other gas species is not jeopardized by the proposed method, i.e., one single vial can be used for analyzing the full chemical composition of a volcanic gas with the exception of NH3. Statistical parameters calculated from gas sampling data at the F5 crater fumarole in Vulcano Island (Aeolian Islands, southern Italy), suggest that the standard error of mean (s/ root n) is higher for S (0.10), followed by SO2, H2S, and CO2 (0.04, 0.038, and 0.028, respectively). SO2 shows the higher variation coefficient (12.1%) followed by H2S, S, and CO2 (5.7, 1.5, and 0.8%, respectively). Furthermore, if the time dependence of sampling is taken into account, the measured values, instead of fluctuating in a random manner, tend to follow systematic patterns, out of statistical control, possibly suggesting a sort of natural fluctuation of the volcanic system. Other crater fumaroles from volcanic systems located in different geodynamical areas (Hawaii, USA, El Chichon, Mexico, Poas, Costa Rica) have been analyzed as well. PMID:11510838

Montegrossi, G; Tassi, F; Vaselli, O; Buccianti, A; Garofalo, K

2001-08-01

300

Process for preparing a sulfurized molybdenum-containing composition and lubricating oil containing said composition  

SciTech Connect

Antioxidant additives for lubricating oil are prepared by combining a polar promoter, ammonium tetrathiomolybdate, and a basic nitrogen compound complex to form a sulfur- and molybdenumcontaining composition.

Devries, L.; King, J.M.

1981-08-11

301

Metabolism of L-methionine linked to the biosynthesis of volatile organic sulfur-containing compounds during the submerged fermentation of Tuber melanosporum.  

PubMed

Tuber melanosporum, known as the black diamond of cuisine, is highly appreciated for its unique and characteristic aroma, which is mainly due to its volatile organic sulfur-containing compounds (VOSCs). In this work, by adding 5 g/L?L-methionine to the fermentation medium, the activities of aminotransferase and ?-ketoacid decarboxylase were significantly enhanced by 103 and 250%, respectively, while the activities of alcohol dehydrogenase and demethiolase were decreased by 277 and 39%. Then, the six VOSCs, i.e., methanethiol (MTL), dimethyl sulfide (DMS), dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS), 3-(methylthio)propanal (methional), and 3-(methylthio)-1-propanol (methionol), were first detected in the submerged fermentation of T. melanosporum. These results indicated that the biosynthesis of VOSCs was triggered by aminotransferase and ?-ketoacid decarboxylase. The production of methional and methionol increased with the increased concentrations of L-methionine (i.e., 5, 10, 15, and 20 g/L) before day 4 of the culture protocol, and methionol was the major product in the Ehrlich pathway. The production of MTL was significantly decreased after day 4 with a significantly increased DMDS, and DMDS was the major product of the demethiolation pathway. Compared with the demethiolation pathway with a total flux of sulfur of 11.33-24.32 ?M, the Ehrlich pathway with a total flux of sulfur of 6,149-10,330 ?M was considered the major pathway for the biosynthesis of VOSCs. This is the first report linking the metabolism of L-methionine to the biosynthesis of VOSCs by the Ehrlich and demethiolation pathways during the submerged fermentation of T. melanosporum. PMID:24092005

Liu, Rui-Sang; Zhou, Huan; Li, Hong-Mei; Yuan, Zhan-Peng; Chen, Tao; Tang, Ya-Jie

2013-12-01

302

Conformational analysis of six-membered, sulfur-containing saturated heterocycles  

SciTech Connect

The area of organosulfur chemistry has grown rapidly during the last 20 years, partly because the structural characteristics of sulfur have led to numerous studies of sulfur bonding, and partly because the unusual reactivity of organic sulfur compounds has resulted in the development of many useful synthetic reagents such as sulfur-stabilized carbanions and sulfur ylides. It is the purpose of this Account to show that the conformational behavior of the title systems is not only interesting but also, in some of its aspects, unusual since it reveals several conformational effects not readily explained in the light of the classical steric and dipolar interactions.

Juaristi, E. (Centro de Investigacion y de Estudios Avanzados del IPN, Apdo (Mexico))

1989-10-01

303

Catalyst for elemental sulfur recovery process  

DOEpatents

A catalytic reduction process is described for the direct recovery of elemental sulfur from various SO[sub 2]-containing industrial gas streams. The catalytic process provides high activity and selectivity, as well as stability in the reaction atmosphere, for the reduction of SO[sub 2] to elemental sulfur product with carbon monoxide or other reducing gases. The reaction of sulfur dioxide and reducing gas takes place over a metal oxide composite catalyst having one of the following empirical formulas: [(FO[sub 2])[sub 1[minus]n](RO)[sub n

Flytzani-Stephanopoulos, M.; Liu, W.

1995-01-24

304

X-ray absorption spectroscopy of bacterial sulfur globules  

SciTech Connect

Sulfur K-edge X-ray absorption spectroscopy is a powerful in situ probe of sulfur biochemistry in intact cells and tissues. Under favorable circumstances the technique can provide quantitative information on the chemical identify of the sulfur species that are present in a sample. Prange et al. have recently reported an X-ray absorption spectroscopic study of bacterial sulfur storage globules. Unfortunately there are substantial problems with the experimental technique employed that, they contend, lead to completely erroneous conclusions. In the more recent of their two papers Prange et al. employed a curve-fitting method similar to that used by us (for more than 10 years). In essence, the method employs simply fitting a linear combination of the spectra of standard compounds to that of the unknown, in this case cultures of bacterial cells. This type of analysis can provide quantitative estimates of the individual sulfur types in the sample, but is critically dependent upon the choice of reference spectra. Prange et al. deduce substantial differences between the chemical forms of sulfur stored in the globules of different organisms; they conclude that the globules of Beggiatoa alba and Thiomargarita namibiensis contain cyclo-octasulfur (S{sub 8}), while those of other organisms contain polythionates (Acidithiobacillus ferrooxidans) and polymeric sulfur (e.g. Allochromatium vinosum). This is in contradiction with an earlier study, in which they found that sulfur in all globule species examined resembled that expected for various sized spherical particles of S{sub 8}. The discrepancy is due to an experimental artefact in the work of Prange et al. arising from their choice of transmittance detection, which is also discussed.

George, Graham N.

2002-08-01

305

Laboratory Studies of the Kinetics of Aqueous Phase Reactions of SO4- and OH Radicals with Organo-Sulfur Compounds of Atmospheric Interest  

NASA Astrophysics Data System (ADS)

As dimethyl sulfide (DMS) undergoes gas-phase oxidization in the atmosphere, the products become progressively less volatile and can be partially partitioned into the condensed phase. Therefore condensed phase transformations may play an important role in the atmospheric chemistry of these species. As part of a research program aimed at developing a detailed understanding of DMS oxidation and its role in the global climate system, we are investigating the aqueous phase reactions between radicals commonly found in the atmospheric condensed phase and organo-sulfur compounds of atmospheric interest. The present study employs a Laser Flash Photolysis-Long Path UV-Visible Absorption technique to investigate the aqueous phase reactions of SO4- and OH radicals with the organo-sulfur species dimethyl sulfoxide (DMSO), dimethyl sulfone (DMSO2), methane sulfinate (MSI), and methane sulfonate (MS). Laser flash photolysis of either S2O82- or H2O2 at 248 nm is used to produce the free radicals. Reactions of SO4- radicals are studied by monitoring the time dependence of the SO4- absorption at 450 nm under pseudo-first order conditions with the organo-sulfur compounds in large excess over SO4-. A competitive kinetics technique is employed in the studies of OH reactions, where the reaction rates of the organo-sulfur species with OH are measured relative to the rate of the reaction of SCN- with OH. The product (SCN)2- from reactions of SCN- with OH (SCN- + OH -> SCN + OH-, SCN + SCN- -> (SCN)2- ), whose concentration decreases with increasing concentration of the organo-sulfur species, is monitored as the kinetic probe (at 475 nm). Room temperature (293+/-1 K) rate coefficients for SO4- reactions with DMSO, DMSO2, MSI, and MS in units of M-1s-1 are found to be (2.6 +/- 0.3) x 109, (3.4 +/- 0.3) x 106, > 5 x 108, and (1.2 +/- 0.1) x 104, respectively, while OH reaction rates in the same units are found to be (5.9 +/- 1.0)x 109, (1.4 +/- 0.5) x 107, (1.1 +/- 0.5) x 109, and (1.0 +/- 0.2) x 107, respectively. Rate coefficients for the SO4- + DMSO2 and MS reactions have not previously been reported. Both previous studies and our studies demonstrate that DMSO and MSI are very reactive species, while DMSO2 and MS are much less reactive. The rate coefficient we report for the OH + MS reaction is much smaller than previously reported values. Temperature-dependent kinetics studies are now in progress and updated results from these studies will be reported.

Zhu, L.; Nicovich, J. M.; Wine, P. H.; Wine, P. H.

2001-12-01

306

Quantifying Individual Potential Contributions of the Hybrid Sulfur Electrolyzer  

E-print Network

transport to the anode influences the concentration of the sulfuric acid produced. The resulting sulfuric loss is the diffusion of SO2 through the sulfuric acid to the catalyst site. Here, we extend our and correlated the operating potential to the sulfuric acid concentration produced at the anode.15-17 We have

Weidner, John W.

307

CONSTRUCTION OF A PROTOTYPE SULFURIC ACID MIST MONITOR  

EPA Science Inventory

A prototype sulfuric acid mist monitor has been constructed for the purpose of detecting sulfuric acid-sulfur trioxide. The monitor utilized the selective condensation method with subsequent determination of sulfuric acid by measuring the conductivity of an aqueous isopropanol so...

308

46 CFR 151.50-21 - Sulfuric acid.  

Code of Federal Regulations, 2012 CFR

...5 2012-10-01 2012-10-01 false Sulfuric acid. 151.50-21 Section 151.50-21 Shipping...CARGOES Special Requirements § 151.50-21 Sulfuric acid. (a) How sulfuric acid may be carried. (1) Sulfuric acid...

2012-10-01

309

46 CFR 151.50-21 - Sulfuric acid.  

Code of Federal Regulations, 2014 CFR

...5 2014-10-01 2014-10-01 false Sulfuric acid. 151.50-21 Section 151.50-21 Shipping...CARGOES Special Requirements § 151.50-21 Sulfuric acid. (a) How sulfuric acid may be carried. (1) Sulfuric acid...

2014-10-01

310

46 CFR 151.50-21 - Sulfuric acid.  

Code of Federal Regulations, 2013 CFR

...5 2013-10-01 2013-10-01 false Sulfuric acid. 151.50-21 Section 151.50-21 Shipping...CARGOES Special Requirements § 151.50-21 Sulfuric acid. (a) How sulfuric acid may be carried. (1) Sulfuric acid...

2013-10-01

311

Geochemical and cosmochemical cycles involving sulfur, sulfide, sulfite and sulfate  

Microsoft Academic Search

Raman spectra of aqueous systems containing sulfur dioxide, elemental sulfur and sulfate indicate that the equilibrium between these species is catalyzed by elemental sulfur. Therefore, dynamic equilibrium can be expected under conditions prevalent on Venus, on Io and in epigenic sulfur deposits.

B. Meyer; L. Peter; M. Ospina

1979-01-01

312

Improvement of cycle property of sulfur electrode for lithium\\/sulfur battery  

Microsoft Academic Search

Although a theoretical specific capacity of lithium\\/sulfur redox couple battery is 1672mAh\\/g, lithium\\/sulfur battery has the serious problems of low utilization of active material and poor rechargeability, due to the loss of active material in the form of soluble polysulfides (Li2Sn, n>2). In this study, carbon nano-fiber having average fiber diameter of 150nm was added into the sulfur electrode in

Young-Jin Choi; Ki-Won Kim; Hyo-Jun Ahn; Jou-Hyeon Ahn

2008-01-01

313

Mass-independent sulfur of inclusions in diamond and sulfur recycling on early Earth.  

PubMed

Populations of sulfide inclusions in diamonds from the Orapa kimberlite pipe in the Kaapvaal-Zimbabwe craton, Botswana, preserve mass-independent sulfur isotope fractionations. The data indicate that material was transferred from the atmosphere to the mantle in the Archean. The data also imply that sulfur is not well mixed in the diamond source regions, allowing for reconstruction of the Archean sulfur cycle and possibly offering insight into the nature of mantle convection through time. PMID:12493909

Farquhar, J; Wing, B A; McKeegan, K D; Harris, J W; Cartigny, P; Thiemens, M H

2002-12-20

314

A Comparative Quantitative Proteomic Study Identifies New Proteins Relevant for Sulfur Oxidation in the Purple Sulfur Bacterium Allochromatium vinosum  

PubMed Central

In the present study, we compared the proteome response of Allochromatium vinosum when growing photoautotrophically in the presence of sulfide, thiosulfate, and elemental sulfur with the proteome response when the organism was growing photoheterotrophically on malate. Applying tandem mass tag analysis as well as two-dimensional (2D) PAGE, we detected 1,955 of the 3,302 predicted proteins by identification of at least two peptides (59.2%) and quantified 1,848 of the identified proteins. Altered relative protein amounts (?1.5-fold) were observed for 385 proteins, corresponding to 20.8% of the quantified A. vinosum proteome. A significant number of the proteins exhibiting strongly enhanced relative protein levels in the presence of reduced sulfur compounds are well documented essential players during oxidative sulfur metabolism, e.g., the dissimilatory sulfite reductase DsrAB. Changes in protein levels generally matched those observed for the respective relative mRNA levels in a previous study and allowed identification of new genes/proteins participating in oxidative sulfur metabolism. One gene cluster (hyd; Alvin_2036-Alvin_2040) and one hypothetical protein (Alvin_2107) exhibiting strong responses on both the transcriptome and proteome levels were chosen for gene inactivation and phenotypic analyses of the respective mutant strains, which verified the importance of the so-called Isp hydrogenase supercomplex for efficient oxidation of sulfide and a crucial role of Alvin_2107 for the oxidation of sulfur stored in sulfur globules to sulfite. In addition, we analyzed the sulfur globule proteome and identified a new sulfur globule protein (SgpD; Alvin_2515). PMID:24487535

Weissgerber, Thomas; Sylvester, Marc; Kröninger, Lena

2014-01-01

315

Sulfur Speciation in Lunar and Terrestrial Apatite  

NASA Astrophysics Data System (ADS)

Apatite from 14072,16, 14053,61, and 14053,241 have S K? peak shifts consistent with incorporation of both sulfide and sulfate. Sulfur concentration is inversely correlated with the percentage of sulfide.

Boyce, J. W.; Ma, C.; Eiler, J. M.; Baker, M. B.; Liu, Y.; Stolper, E. M.; Taylor, L. A.

2012-03-01

316

The sulfur thermochemical cycle for hydrogen production  

NASA Astrophysics Data System (ADS)

Results of research on sulfur-cycle hydrogen production are presented. An H2S cycle using MoS2 as a catalyst is mentioned as showing promise for thermochemical water splitting, with an equilibrium reaction yield of 7%. Use of I or Pt as catalysts raised efficiencies to 16 and 12%, respectively, and further studies employing hybrid cycles with CO2-S and noble metals are reviewed. Thermal decomposition reactions with sulfuric acid are examined, noting a potential 30% thermal efficiency, and sulfur cycle research being undertaken at various industrial laboratories is outlined. It is noted that experiments with sulfuric acid salts for water electrolysis at Los Alamos will probably use solar collectors as a heat source.

Dokiya, M.

1981-07-01

317

Sulfur Dioxide: Its Role in Climate Change  

NSDL National Science Digital Library

In this problem-based learning activity, learners investigate impact of sulfur dioxide on the environment. Sulfur dioxide comes from both human activities and natural sources. Burning coal and other fossil fuels is the largest source of sulfur dioxide from human activities. Students have a choice of analyzing the impact of volcanoesâ emissions of sulfur dioxide on the environment; they can also investigate the idea of injecting sulfates into the atmosphere to counteract global warming. Instructions to access NASA data are provided along with additional resources and activities. This module was developed to be used in the Earth System Science Education Alliance (ESSEA) courses for middle and high school teachers and is also available to teachers to adapt for general classroom use.

318

Sulfur Hexafluoride Tracer Dispersion within Cherry Orchard  

E-print Network

Sulfur Hexafluoride Tracer Dispersion within Cherry Orchard Zeyuan Chen, S. Edburg, and B. Lamb the correspondence between tracer gas concentration and atmospheric stability. Within the Tukey Cherry Orchard, we

Collins, Gary S.

319

Definition of Non-Conventional Sulfur Utilization in Western Kazakhstan for Sulfur Concrete (Phase 1)  

SciTech Connect

Battelle received a contract from Agip-KCO, on behalf a consortium of international oil and gas companies with exploration rights in the North Caspian Sea, Kazakhstan. The objective of the work was to identify and help develop new techniques for sulfur concrete products from waste, by-product sulfur that will be generated in large quantitites as drilling operations begin in the near future. BNL has significant expertise in the development and use of sulfur concrete products and has direct experience collaborating with the Russian and Kazakh partners that participated. Feasibility testing was successfully conducted for a new process to produce cost-effective sulfur polymer cement that has broad commerical applications.

Kalb, Paul

2007-05-31

320

Effects of variation of dietary sulfur on movement of sulfur in sheep rumen  

SciTech Connect

Effects of variations in dietary sulfur on rumen sulfur dynamics were studied under steady state conditions. In the first experimental period, three sheep were given 33.3 g of a pelleted diet hourly containing 1.59 g sulfur/kg (low) and in the second period the sulfur content was increased to 3.21 g/kg (high) by the addition of sodium sulfate. The daily sulfur intake was 1.158 g on the low sulfur diet and .545 g of this passed from the rumen in protein, .614 g was calculated to be absorbed from the rumen as sulfide, and .052 g was estimated to be recycled to the rumen. For sheep with daily intakes of 2.317 g sulfur, 1.212 g passed from the rumen in protein, 1.078 g was absorbed from the rumen, and .093 g was estimated to be recycled. It was estimated that 127 and 165 g microbial protein were synthesized/kg organic matter truly digested in the rumen for low and high sulfur diets, respectively. A simple model using simultaneous equations was proposed to describe rumen sulfur metabolism.

Kandylis, K.; Bray, A.C.

1987-01-01

321

Field-deployable instrumentation for fast measurement of various atmospheric sulfur compounds in the parts per trillion range  

NASA Astrophysics Data System (ADS)

A field deployable instrumentation was developed for determining atmospheric dimethyl sulfide (DMS), dimethyl sulfoxide (DMSO), dimethyl sulfone (DMSO 2) and sulfur dioxide (SO2) using atmospheric pressure ionization mass spectrometry (APIMS) Isotopically labeled analytes were used as internal standards. Detection limits below 1 part per trillion by volume (pptv) (S/N is >5 at 0.5 pptv background level) at one sample per second was achieved. Extensive laboratory studies were conducted to evaluate the instrument's sensitivity and stability as well as to simulate the real time measurements. This dissertation reports data from a first time deployment of the instrumentation at the South Pole in December 1998 and January 1999. Data from this deployment showed that this instrumentation had adequate performance in detecting all four species. In addition, methane sulfinic acid (MESA) was also observed in the atmosphere for first real time. The lowest concentrations of all four species occurred when the temperature inversion was strongest and greatest when the inversion was weakest or absent. This observation implies that the origin of these species is the free troposphere just above the inversion and not from local pollution. The most found concentrations for DMS, DMSO, DMSO2, MESA and SO 2 were 0.7, 0.9, 1.2, 0.1 and 9 pptv. These field tests further suggest that our APIMS instrumentation be adequate for determining the fluxes of DMS and SO2 by eddy correlation technique. Finally, in the South Pole data there was strong evidence that H2O2 and HNO 3 were observed as complexes with CO3-. This implies that these species could be determined by APIMS if isotopically labeled standards of the species are used and a means of determining the blank is established.

Xu, Nucleus He

322

Polymer Electrolytes for Lithium/Sulfur Batteries  

PubMed Central

This review evaluates the characteristics and advantages of employing polymer electrolytes in lithium/sulfur (Li/S) batteries. The main highlights of this study constitute detailed information on the advanced developments for solid polymer electrolytes and gel polymer electrolytes, used in the lithium/sulfur battery. This includes an in-depth analysis conducted on the preparation and electrochemical characteristics of the Li/S batteries based on these polymer electrolytes. PMID:24958296

Zhao, Yan; Zhang, Yongguang; Gosselink, Denise; Doan, The Nam Long; Sadhu, Mikhail; Cheang, Ho-Jae; Chen, Pu

2012-01-01

323

Polymer electrolytes for lithium/sulfur batteries.  

PubMed

This review evaluates the characteristics and advantages of employing polymer electrolytes in lithium/sulfur (Li/S) batteries. The main highlights of this study constitute detailed information on the advanced developments for solid polymer electrolytes and gel polymer electrolytes, used in the lithium/sulfur battery. This includes an in-depth analysis conducted on the preparation and electrochemical characteristics of the Li/S batteries based on these polymer electrolytes. PMID:24958296

Zhao, Yan; Zhang, Yongguang; Gosselink, Denise; Doan, The Nam Long; Sadhu, Mikhail; Cheang, Ho-Jae; Chen, Pu

2012-01-01

324

Leaching behavior of ilmenite with sulfuric acid  

Microsoft Academic Search

A study of the rate of dissolution of ilmenite in sulfuric acid solutions has been carried out. The effects of temperature,\\u000a particle size, stirring speed, and concentration of sulfuric acid on the rate of dissolution of ilmenite has been investigated.\\u000a Temperature range studied in this investigation was 88? to 115?C, and the Arrhenius activation energy was found to be 64.4

K. N. Han; T. Rubcumintara; M. C. Fuerstenau

1987-01-01

325

Sensitivity of mosses to sulfur dioxide  

Microsoft Academic Search

Seven North American moss species responded differentially to fumigations with sulfur dioxide ranging from 0.5 to 4.0 ppm. Leucobryum glaucum and Dicranum scoparium were the most sensitive species; Dicranella heterophylla, Polytrichum ohioense and Pottia truncata, the most resistant. The results of fumigations with 0.1 to 4.0 ppm sulfur dioxide for 8 hours on cultured gametophytes of Polytrichum ohioense indicate that

T. H. Nash; E. H. Nash

1974-01-01

326

Sulfur mustard and respiratory diseases.  

PubMed

Victims exposed to sulfur mustard (HD) in World War I and Iran-Iraq war, and those suffered occupational or accidental exposure have endured discomfort in the respiratory system at early stages after exposure, and marked general physical deterioration at late stages due to pulmonary fibrosis, bronchiolitis obliterans or lung cancer. At molecule levels, significant changes of cytokines and chemokines in bronchoalveolar lavage and serum, and of selectins (in particular sE-selectin) and soluble Fas ligand in the serum have been reported in recent studies of patients exposed to HD in Iran-Iraq war, suggesting that these molecules may be associated with the pathophysiological development of pulmonary diseases. Experimental studies in rodents have revealed that reactive oxygen and nitrogen species, their product peroxynitrite (ONOO(-)), nitric oxide synthase, glutathione, poly (adenosine diphosphate-ribose) polymerase, activating protein-1 signaling pathway are promising drug targets for preventing HD-induced toxicity, whereas N-acetyl cysteine, tocopherols, melatonin, aprotinin and many other molecules have been proved to be effective in prevention of HD-induced damage to the respiratory system in different animal models. In this paper, we will systemically review clinical and pathophysiological changes of respiratory system in victims exposed to HD in the last century, update clinicians and researchers on the mechanism of HD-induced acute and chronic lung damages, and on the relevant drug targets for future development of antidotes for HD. Further research directions will also be proposed. PMID:22742653

Tang, Feng Ru; Loke, Weng Keong

2012-09-01

327

Antioxidants countermeasures against sulfur mustard.  

PubMed

Sulfur mustard (SM) is a vesicant chemical warfare agent that persists as a serious menace from the viewpoint of acute and chronic toxicity, simple synthesis and no effective treatment currently being available. The two most deleterious basic molecular mechanisms in SM poisoning are: inflammation and over-activation of poly(ADP-ribose) polymerase and the resulting DNA alkylation. Oxidative stress is the common consequence of these pathway activations. In the present review, the significance of oxidative stress in SM poisoning is discussed along with research on antioxidant therapy as a suitable antidote. The temporal dynamics of the redox imbalance, the antioxidant depletion and impact this has on tissues are described as the pathologies induced by SM. Special attention is paid to ameliorating the damage using low molecular weight antioxidants. Melatonin, epigallocatechin gallate and flavone derivatives, in particular, have been studied in recent experiments. The suitability of these antioxidants for therapy purposes is considered in a separate chapter. The review concludes with a view to the future and the studies needed on antioxidant therapy as a countermeasure to SM poisoning. PMID:22512566

Pohanka, M

2012-07-01

328

The biology of reactive sulfur species (RSS).  

PubMed

Sulfur is an essential and quantitatively important element for living organisms. Plants contain on average approximately 1 g S kg?¹ dry weight (for comparison plants contain approximately 15 g N kg?¹ dry weight). Sulfur is a constituent of many organic molecules, for example amino acids such as cysteine and methionine and the small tripeptide glutathione, but sulfur is also essential in the form of Fe-S clusters for the activity of many enzymes, particularly those involved in redox reactions. Sulfur chemistry is therefore important. In particular, sulfur in the form of thiol groups is central to manifold aspects of metabolism. Because thiol groups are oxidized and reduced easily and reversibly, the redox control of cellular metabolism has become an increasing focus of research. In the same way that oxygen and nitrogen have reactive species (ROS and RNS), sulfur too can form reactive molecular species (RSS), for example when a -SH group is oxidized. Indeed, several redox reactions occur via RSS intermediates. Several naturally occurring S-containing molecules are themselves RSS and because they are physiologically active they make up part of the intrinsic plant defence repertoire against herbivore and pathogen attack. Furthermore, RSS can also be used as redox-active pharmacological tools to study cell metabolism. The aim of this review is to familiarize the general reader with some of the chemical concepts, terminology and biology of selected RSS. PMID:22541352

Gruhlke, Martin C H; Slusarenko, Alan J

2012-10-01

329

Sulfur "Concrete" for Lunar Applications - Sublimation Concerns  

NASA Technical Reports Server (NTRS)

Melting sulfur and mixing it with an aggregate to form "concrete" is commercially well established and constitutes a material that is particularly well-suited for use in corrosive environments. Discovery of the mineral troilite (FeS) on the moon poses the question of extracting the sulfur for use as a lunar construction material. This would be an attractive alternative to conventional concrete as it does not require water. However, the viability of sulfur concrete in a lunar environment, which is characterized by lack of an atmosphere and extreme temperatures, is not well understood. Here it is assumed that the lunar ore can be mined, refined, and the raw sulfur melded with appropriate lunar regolith to form, for example, bricks. This study evaluates pure sulfur and two sets of small sulfur concrete samples that have been prepared using JSC-1 lunar stimulant and SiO2 powder as aggregate additions. Each set was subjected to extended periods in a vacuum environment to evaluate sublimation issues. Results from these experiments are presented and discussed within the context of the lunar environment.

Grugel, Richard N.; Toutanji, Houssam

2006-01-01

330

Effects of dynamic electrodes on sodium sulfur cell performance  

Microsoft Academic Search

In this paper the construction and performance of a sodium sulfur cell with dynamic sodium and sulfur electrodes are described. The cell was constructed with a sodium feed into a β{double prime}-alumina tube and a sulfur feed into an annular sulfur electrode. Low-resistance graphite felt was tightly packed around the β{double prime}-alumina tube. Sodium pentasulfide was removed from the sulfur

H. Tokoi; N. Watahiki; I. Sumida

1991-01-01

331

Novel cysteine-centered sulfur metabolic pathway in the thermotolerant methylotrophic yeast Hansenula polymorpha.  

PubMed

In yeast and filamentous fungi, sulfide can be condensed either with O-acetylhomoserine to generate homocysteine, the precursor of methionine, or with O-acetylserine to directly generate cysteine. The resulting homocysteine and cysteine can be interconverted through transsulfuration pathway. Here, we systematically analyzed the sulfur metabolic pathway of the thermotolerant methylotrophic yeast Hansenula polymorpha, which has attracted much attention as an industrial yeast strain for various biotechnological applications. Quite interestingly, the detailed sulfur metabolic pathway of H. polymorpha, which was reconstructed based on combined analyses of the genome sequences and validation by systematic gene deletion experiments, revealed the absence of de novo synthesis of homocysteine from inorganic sulfur in this yeast. Thus, the direct biosynthesis of cysteine from sulfide is the only pathway of synthesizing sulfur amino acids from inorganic sulfur in H. polymorpha, despite the presence of both directions of transsulfuration pathway Moreover, only cysteine, but no other sulfur amino acid, was able to repress the expression of a subset of sulfur genes, suggesting its central and exclusive role in the control of H. polymorpha sulfur metabolism. 35S-Cys was more efficiently incorporated into intracellular sulfur compounds such as glutathione than 35S-Met in H. polymorpha, further supporting the cysteine-centered sulfur pathway. This is the first report on the novel features of H. polymorpha sulfur metabolic pathway, which are noticeably distinct from those of other yeast and filamentous fungal species. PMID:24959887

Sohn, Min Jeong; Yoo, Su Jin; Oh, Doo-Byoung; Kwon, Ohsuk; Lee, Sang Yup; Sibirny, Andriy A; Kang, Hyun Ah

2014-01-01

332

Novel Cysteine-Centered Sulfur Metabolic Pathway in the Thermotolerant Methylotrophic Yeast Hansenula polymorpha  

PubMed Central

In yeast and filamentous fungi, sulfide can be condensed either with O-acetylhomoserine to generate homocysteine, the precursor of methionine, or with O-acetylserine to directly generate cysteine. The resulting homocysteine and cysteine can be interconverted through transsulfuration pathway. Here, we systematically analyzed the sulfur metabolic pathway of the thermotolerant methylotrophic yeast Hansenula polymorpha, which has attracted much attention as an industrial yeast strain for various biotechnological applications. Quite interestingly, the detailed sulfur metabolic pathway of H. polymorpha, which was reconstructed based on combined analyses of the genome sequences and validation by systematic gene deletion experiments, revealed the absence of de novo synthesis of homocysteine from inorganic sulfur in this yeast. Thus, the direct biosynthesis of cysteine from sulfide is the only pathway of synthesizing sulfur amino acids from inorganic sulfur in H. polymorpha, despite the presence of both directions of transsulfuration pathway Moreover, only cysteine, but no other sulfur amino acid, was able to repress the expression of a subset of sulfur genes, suggesting its central and exclusive role in the control of H. polymorpha sulfur metabolism. 35S-Cys was more efficiently incorporated into intracellular sulfur compounds such as glutathione than 35S-Met in H. polymorpha, further supporting the cysteine-centered sulfur pathway. This is the first report on the novel features of H. polymorpha sulfur metabolic pathway, which are noticeably distinct from those of other yeast and filamentous fungal species. PMID:24959887

Oh, Doo-Byoung; Kwon, Ohsuk; Lee, Sang Yup; Sibirny, Andriy A.; Kang, Hyun Ah

2014-01-01

333

Composition of acid tars from sulfuric acid treatment of petroleum oils  

Microsoft Academic Search

In the production of distillate and residual lube oils, the lube stocks may be treated with concentrated sulfuric acid or oleum. This removes unsaturates, aromatics, sulfur compounds, nitrogen compounds and resinous substances, all of which are materials that lower the stability and have a detrimental effect on the service indexes of commercial petroleum oils. Acid tar is formed as a

A. F. Frolov; T. S. Titova; I. V. Karpova; T. L. Denisova

1985-01-01

334

Identification of control parameters for the sulfur gas storability with bag sampling methods  

Technology Transfer Automated Retrieval System (TEKTRAN)

Air samples containing sulfur compounds are often collected and stored in sample bags prior to analyses. The storage stability of six gaseous sulfur compounds (H2S, CH3SH, DMS, CS2, DMDS and SO2) was compared between two different bag materials (polyvinyl fluoride (PVF) and polyester aluminum (PEA))...

335

He(I)\\/He(II) ultraviolet photoelectron spectroscopic studies on organosulfur compounds with emphasis on the sulfur–oxygen interaction 1 In honor of Professor Árpad Kucsman on the occasion of his 70th birthday. 1  

Microsoft Academic Search

The electronic structure of compounds having the possibility of exhibiting intramolecular sulfur–oxygen non-bonded interaction of the S(II, IV or VI)?O(carbonyl or nitro) type and a hypervalent sulfur atom of the O–S–O type — i.e, R–S–Me, R–SO–Me, R–SO2–Me (R=2-nitrophenyl; 2, 7 and 12), R–S–R, R–SO–R, R–SO2–R (R=2-methoxycarbonylphenyl; 5, 10 and 15) and spirosulfurane (16) — have been investigated by the He(I)

István Pál Csonka; Gábor Vass; László Szepes; Dénes Szabó; István Kapovits

1998-01-01

336

Process and apparatus for generating elemental sulfur and re-usable metal oxide from spent metal sulfide sorbents  

DOEpatents

A process and apparatus for generating elemental sulfur and re-usable metal oxide from spent metal-sulfur compound. Spent metal-sulfur compound is regenerated to re-usable metal oxide by moving a bed of spent metal-sulfur compound progressively through a single regeneration vessel having a first and second regeneration stage and a third cooling and purging stage. The regeneration is carried out and elemental sulfur is generated in the first stage by introducing a first gas of sulfur dioxide which contains oxygen at a concentration less than the stoichiometric amount required for complete oxidation of the spent metal-sulfur compound. A second gas containing sulfur dioxide and excess oxygen at a concentration sufficient for complete oxidation of the partially spent metal-sulfur compound, is introduced into the second regeneration stage. Gaseous sulfur formed in the first regeneration stage is removed prior to introducing the second gas into the second regeneration stage. An oxygen-containing gas is introduced into the third cooling and purging stage. Except for the gaseous sulfur removed from the first stage, the combined gases derived from the regeneration stages which are generally rich in sulfur dioxide and lean in oxygen, are removed from the regenerator as an off-gas and recycled as the first and second gas into the regenerator. Oxygen concentration is controlled by adding air, oxygen-enriched air or pure oxygen to the recycled off-gas.

Ayala, Raul E. (Clifton Park, NY); Gal, Eli (Lititz, PA)

1995-01-01

337

Coal gasification: molten salt processes for sulfur emission control  

Microsoft Academic Search

Two molten salt desulfurization processes are illustrated. ; Precombustion desulfurization of coal takes place in a single vessel. Pulverized ; coal, slurried with molten salt, is allowed to react with a melt that contains an ; agent with an affinity for the sulfurous compounds. The coal collects at the ; top, being less dense than the melt, and is drawn

Glueck

1973-01-01

338

Recovery of selenium sludges in sulfuric acid production  

Microsoft Academic Search

Most of the selenium compounds formed in the production of sulfuric acid when roasting pyrites is sent together with the roaster gas and residues of cinder dust to the equipment in the wash division. Recovery of these sludges from the wash acid is the subject discussed in the present report. Analysis of the total variety of aspects related to the

V. S. Epifanov; G. B. Kabanova; L. V. Konyakhina; V. G. Moshkova; V. P. Syskova

1983-01-01

339

Ring cleavage of sulfur heterocycles: how does it happen?  

Microsoft Academic Search

Sulfur heterocycles are common constituents ofpetroleum and liquids derived from coal, and they arefound in some secondary metabolites of microorganismsand plants. They exist primarily as saturated ringsand thiophenes. There are two major objectives drivinginvestigations of the microbial metabolism oforganosulfur compounds. One is the quest to develop aprocess for biodesulfurization of fossil fuels, andthe other is to understand the fates of

David C. Bressler; Jason A. Norman; Phillip M. Fedorak

1998-01-01

340

Workshop on sulfur chemistry in flue gas desulfurization  

SciTech Connect

The Flue Gas Desulfurization Workshop was held at Morgantown, West Virginia, June 7-8, 1979. The presentations dealt with the chemistry of sulfur and calcium compounds in scrubbers. DOE and EPRI programs in this area are described. Ten papers have been entered individually into EDB and ERA. (LTN)

Wallace, W.E. Jr.

1980-05-01

341

Processing of the Pyrite Concentrates to Generate Sulfurous Anhydride for Sulfuric Acid Production  

Microsoft Academic Search

The results of two-stage roasting of pyrite concentrate with air blowing and the principle scheme of the process are presented in the report. The results of experimental sulfuric acid production tests using pyrite concentrate to generate sulfurous rich gas containing 0.1 - 0.15% of sulphur trioxide are shown. Comparative characteristics with technologies known for the present are given.

T. A. Chepushtanova; V. A. Luganov

342

Process for the manufacture of sulfur or sulfuric acid from coke oven gas  

Microsoft Academic Search

A process for the complete elimination of ammonia and hydrogen sulfide from coke oven gases is described which does not lead to the occurrence of sulfur dioxide-containing condensates as in prior-art methods. Most of the hydrogen sulfide combustion gases are cooled only to the point where elementary sulfur condenses out on the cooler bottom. The process initially involves scrubbing the

G. Wunderlich; H. Weber

1974-01-01

343

Fibrous hybrid of graphene and sulfur nanocrystals for high-performance lithium-sulfur batteries.  

PubMed

Graphene-sulfur (G-S) hybrid materials with sulfur nanocrystals anchored on interconnected fibrous graphene are obtained by a facile one-pot strategy using a sulfur/carbon disulfide/alcohol mixed solution. The reduction of graphene oxide and the formation/binding of sulfur nanocrystals were integrated. The G-S hybrids exhibit a highly porous network structure constructed by fibrous graphene, many electrically conducting pathways, and easily tunable sulfur content, which can be cut and pressed into pellets to be directly used as lithium-sulfur battery cathodes without using a metal current-collector, binder, and conductive additive. The porous network and sulfur nanocrystals enable rapid ion transport and short Li(+) diffusion distance, the interconnected fibrous graphene provides highly conductive electron transport pathways, and the oxygen-containing (mainly hydroxyl/epoxide) groups show strong binding with polysulfides, preventing their dissolution into the electrolyte based on first-principles calculations. As a result, the G-S hybrids show a high capacity, an excellent high-rate performance, and a long life over 100 cycles. These results demonstrate the great potential of this unique hybrid structure as cathodes for high-performance lithium-sulfur batteries. PMID:23672616

Zhou, Guangmin; Yin, Li-Chang; Wang, Da-Wei; Li, Lu; Pei, Songfeng; Gentle, Ian Ross; Li, Feng; Cheng, Hui-Ming

2013-06-25

344

Airborne sulfur trace species intercomparison campaign: Sulfur dioxide, dimethylsulfide, hydrogen sulfide, carbon disulfide, and carbonyl sulfide  

NASA Technical Reports Server (NTRS)

Results from an airborne intercomparison of techniques to measure tropospheric levels of sulfur trace gases are presented. The intercomparison was part of the NASA Global Tropospheric Experiment (GTE) and was conducted during the summer of 1989. The intercomparisons were conducted on the Wallops Electra aircraft during flights from Wallops Island, Virginia, and Natal, Brazil. Sulfur measurements intercompared included sulfur dioxide (SO2), dimethylsulfide (DMS), hydrogen sulfide (H2S), carbon disulfide (CS2), and carbonyl sulfide (OCS). Measurement techniques ranged from filter collection systems with post-flight analyses to mass spectrometer and gas chromatograph systems employing various methods for measuring and identifying the sulfur gases during flight. Sampling schedules for the techniques ranged from integrated collections over periods as long as 50 minutes to one- to three-minute samples every ten or fifteen minutes. Several of the techniques provided measurements of more than one sulfur gas. Instruments employing different detection principles were involved in each of the sulfur intercomparisons. Also included in the intercomparison measurement scenario were a host of supporting measurements (i.e., ozone, nitrogen oxides, carbon monoxide, total sulfur, aerosols, etc.) for purposes of: (1) interpreting results (i.e., correlation of any noted instrument disagreement with the chemical composition of the measurement environment); and (2) providing supporting chemical data to meet CITE-3 science objectives of studying ozone/sulfur photochemistry, diurnal cycles, etc. The results of the intercomparison study are briefly discussed.

Gregory, Gerald L.; Hoell, James M., Jr.; Davis, Douglas D.

1991-01-01

345

Determination of polycyclic aromatic sulfur heterocycles in diesel particulate matter and diesel fuel by gas chromatography with atomic emission detection.  

PubMed

The sulfur content of diesel fuel is of environmental concern because sulfur can facilitate the formation of diesel particulate matter (DPM) and sulfur dioxide (SO2) in the exhaust can poison catalytic converters. The US Environmental Protection Agency (EPA) has established more stringent regulations to reduce the sulfur content of diesel fuels in the near future. In this study, various types of organosulfur compounds in DPM extracts and the corresponding fuels have been determined by gas chromatography with atomic emission detection. The diesel fuels used have sulfur contents of 2284 and 433 ppm, respectively, and are labeled as high-sulfur and low-sulfur diesel fuels. The compounds identified are mainly polycyclic aromatic sulfur heterocycles (PASHs). In the fuels tested, trimethylbenzothiophenes (TMBTs), dibenzothiophenes (DBTs), and 4-methyldibenzothiophene (4-MDBT) were the most abundant sulfur compounds, while larger PASH compounds were more abundant in DPM extracts. The high-sulfur diesel fuel contained a larger proportion of PASHs with one or two rings (lighter PASHs). In DPM, the concentrations of total organic sulfur and individual PASHs are higher for the high-sulfur diesel fuel, and the relative percentage of one or two-ring PASHs is higher as well. The influence of engine load on the DPM composition was also examined. With increasing load, the PASH concentration in DPM decreased for lighter PASHs, increased for heavier PASHs, and had a bell-shaped distribution for PASHs in between. PMID:16574137

Liang, Fuyan; Lu, Mingming; Birch, M Eileen; Keener, Tim C; Liu, Zifei

2006-05-01

346

40 CFR Appendix T to Part 50 - Interpretation of the Primary National Ambient Air Quality Standards for Oxides of Sulfur (Sulfur...  

Code of Federal Regulations, 2012 CFR

...National Ambient Air Quality Standards for Oxides of Sulfur (Sulfur Dioxide) T Appendix...National Ambient Air Quality Standards for Oxides of Sulfur (Sulfur Dioxide) 1. General...national ambient air quality standards for Oxides of Sulfur as measured by Sulfur...

2012-07-01

347

Failure to Insert the Iron-Sulfur Cluster into the Rieske Iron-Sulfur Protein Impairs Both Center N and Center P of the  

E-print Network

Failure to Insert the Iron-Sulfur Cluster into the Rieske Iron-Sulfur Protein Impairs Both Center N to the iron-sulfur cluster of the Rieske iron-sulfur protein to a cysteine results in a respiratory-deficient yeast strain due to formation of iron-sulfur protein lacking the iron- sulfur cluster. The Rieske

Trumpower, Bernard L.

348

Modern applications for a total sulfur reduction distillation method - what’s old is new again  

PubMed Central

Background The use of a boiling mixture of hydriodic acid, hypophosphorous acid, and hydrochloric acid to reduce any variety of sulfur compounds has been in use in various applications since the first appearance of this method in the literature in the 1920’s. In the realm of sulfur geochemistry, this method remains a useful, but under-utilized technique. Presented here is a detailed description of the distillation set-up and procedure, as well as an overview of potential applications of this method for marine sulfur biogeochemistry/isotope studies. The presented applications include the sulfur isotope analysis of extremely low amounts of sulfate from saline water, the conversion of radiolabeled sulfate into sulfide, the extraction of refractory sulfur from marine sediments, and the use of this method to assess sulfur cycling in Aarhus Bay sediments. Results The STrongly Reducing hydrIodic/hypoPhosphorous/hydrochloric acid (STRIP) reagent is capable of rapidly reducing a wide range of sulfur compounds, including the most oxidized form, sulfate, to hydrogen sulfide. Conversion of as little as approximately 5 micromole sulfate is possible, with a sulfur isotope composition reproducibility of 0.3 permil. Conclusions Although developed many decades ago, this distillation method remains relevant for many modern applications. The STRIP distillation quickly and quantitatively converts sulfur compounds to hydrogen sulfide which can be readily collected in a silver nitrate trap for further use. An application of this method to a study of sulfur cycling in Aarhus Bay demonstrates that we account for all of the sulfur compounds in pore-water, effectively closing the mass balance of sulfur cycling. PMID:24808759

2014-01-01

349

Sulfur isotope fractionation during the reduction of elemental sulfur and thiosulfate by Dethiosulfovibrio spp.  

NASA Astrophysics Data System (ADS)

Thiosulfate and elemental sulfur are typical by-products of the oxidation of dissolved sulfide and important sulfur intermediates in the biogeochemical sulfur cycle of natural sediments where they can be further transformed by microbial or chemical oxidation, reduction, or disproportionation. Due to the often superimposing reaction pathways of the sulfur intermediates in natural environments specific tracers are needed to better resolve the complex microbial and biogeochemical reactions. An important fingerprint for sulfur cycling is provided by the microbial fractionation of the stable sulfur isotopes S-34 and S-32. Proper interpretation of isotope signals in nature, however, is only possible by the calibration with results obtained with pure cultures under defined experimental conditions. In addition, sulfur isotope discrimination may provide informations about specific encymatic biochemical pathways within the bacterial cells. In this study, we report the results for the discrimination of stable sulfur isotopes S-32 and S-34 during reduction of thiosulfate and elemental sulfur by non-sulfate, but sulfur- and thiosulfate-reducing bacteria which are phylogenetically not related to sulfate-reducing bacteria. Experiments with were conducted at known cell-specific thiosulfate reduction rates. Stable sulfur isotope fractionation was investigated during reduction of thiosulfate and elemental sulfur at 28°C by growing batch cultures of Dethiosulfovibrio marinus WS100 (type strain DSM 12537) and Dethiosulfovibrio russensis (type strain DSM 12538) using citrate as carbon and energy source. The cell-specific reduction rates were 0.3 to 2.4 fmol cell-1 d-1 (thiosulfate) and 31 to 38 fmol cell-1 d-1 (elemental sulphur), respectively. The sulfide produced was depleted in S-34 by 12 per mil compared to total thiosulfate sulfur, close to previous results observed for sulfate-reducing bacteria, indicating that the thiosulfate-reducing mechanism of sulfate reducers is similar to that of the investigated thiosulfate-reducing strains. Elemental sulfur reduction yields sulfide depleted in S-34 and isotope fractionation effects between 1.3 and 5.2 per mil for Dethiosulfovibrio russensis and 1.7 and 5.1 per mil Dethiosulfovibrio marinus, with the smaller fractionation effects observed in the exponential growth phase and enhanced discrimination under conditions of citrate depletion and cell lysis.

Surkov, A. V.; Böttcher, M. E.; Kuever, J.

2009-04-01

350

A primer on sulfur for the planetary geologist  

NASA Technical Reports Server (NTRS)

Sulfur has been proposed as the dominant composition for the volcanic material on Io. Sulfur is a complex element which forms many intramolecular and intermolecular allotropes exhibiting a variety of physical properties. Cyclo-S8 sulfur is the most abundant and stable molecular form. The important molecular species within liquid sulfur change in concentration with temperature. Concentrations of the allotropes control the physical properties of the melt. Discontinuities in density, viscosity, and thermal properties reflect the polymerization process within liquid sulfur. Variations in the melting point are related to autodissociation of the liquid. Many solids forms of sulfur have been identified but only orthorhombic alpha and monoclinic beta sulfur, both composed of cyclo-S8 sulfur, are stable under terrestrial conditions. Physical properties of solid sulfur are dependent on the allotrope and, in some cases, the thermal history. Three natural terrestrial sulfur flows are described: (1) Siretoko-Iosan, Japan; (2) Volcan Azufre, Galapagos Islands; and (3) Mauna Loa, Hawaii. All of the flows are associated with fumarolic areas and are considered to have formed by the melting and mobilization of sulfur deposits. Surface textures of the flows indicate a behavior of molten sulfur similar to that of silicate lava. Channels, rivulets, and lobate edges were described for the flows. The solidification of man-made sulfur flows formed as part of the Frasch mining process by which sulfur is removed from the subsurface in a liquid state is described.

Theilig, E.

1982-01-01

351

40 CFR 721.7770 - Alkylphenoxypoly(oxyethylene) sulfuric acid ester, substituted amine salt.  

Code of Federal Regulations, 2011 CFR

...Alkylphenoxypoly(oxyethylene) sulfuric acid ester, substituted amine salt...Alkylphenoxypoly(oxyethylene) sulfuric acid ester, substituted amine salt...alkyl phenoxypoly(oxyethylene) sulfuric acid ester, substituted amine...

2011-07-01

352

40 CFR 721.7770 - Alkylphenoxypoly(oxyethylene) sulfuric acid ester, substituted amine salt.  

Code of Federal Regulations, 2013 CFR

...Alkylphenoxypoly(oxyethylene) sulfuric acid ester, substituted amine salt...Alkylphenoxypoly(oxyethylene) sulfuric acid ester, substituted amine salt...alkyl phenoxypoly(oxyethylene) sulfuric acid ester, substituted amine...

2013-07-01

353

40 CFR 721.7770 - Alkylphenoxypoly(oxyethylene) sulfuric acid ester, substituted amine salt.  

Code of Federal Regulations, 2014 CFR

...Alkylphenoxypoly(oxyethylene) sulfuric acid ester, substituted amine salt...Alkylphenoxypoly(oxyethylene) sulfuric acid ester, substituted amine salt...alkyl phenoxypoly(oxyethylene) sulfuric acid ester, substituted amine...

2014-07-01

354

New developments in lithium sulfur batteries  

NASA Astrophysics Data System (ADS)

In this work, efforts were conducted in order to mitigate the issue of polysulfides dissolution and hence to improve the capacity and efficiency of Li-sulfur cells. The first approach was achieved by optimizing the amount of sulfur that can be contained in the sulfur/carbon electrode. Five sulfur/carbon ratios were prepared- (1) 50/50, (2) 60/40, (3) 70/30, (4) 80/20, and (5) 90/10- to study the effect of carbon contents on electrochemical cycling. The second approach was by adding nano-sized TiO2 particles having a large specific surface area as the polysulfide adsorbing agent in the electrodes. The impact of nano-sized TiO2 particles in improving the electrochemical properties of sulfur electrodes was investigated using CV measurements and charge/discharge tests. To further enhance the efficiency and cycling stability of Li-S batteries, a novel polysulfide electrolyte was developed. This new electrolyte mainly consisted of pre-dissolved lithium polysulfides (Li2Sx) as an alternative electrolyte salt to replace the lithium bis(trifluoromethanesulfone)imide (LiTFSI). We also used LiNO3 to mitigate the shuttle mechanism that occurs in Li-S cells during the charge and discharge. By creating a dynamic equilibrium at the interface of the cathode and electrolyte, the dissolution of lithium polysulfides, and thus the loss of active materials from the cathode during the discharge and charge of the cell, was greatly prevented.

Xu, Rui; Belharouak, Ilias; Zhang, Xiaofeng; Polzin, Bryant; Li, James C. M.

2013-05-01

355

Emissions of sulfur gases from wetlands  

NASA Technical Reports Server (NTRS)

Data on the emissions of sulfur gases from marine and freshwater wetlands are summarized with respect to wetland vegetation type and possible formation mechanisms. The current data base is largest for salt marshes inhabited by Spartina alterniflora. Both dimethyl sulfide (DMS) and hydrogen sulfide (H2S) dominate emissions from salt marshes, with lesser quantities of methyl mercaptan (MeSH), carbonyl sulfide (COS), carbon disulfide (CS2) and dimethyl disulfide (DMDS) being emitted. High emission rates of DMS are associated with vegetation that produces the DMS precursor dimethylsulfonionpropionate (DMSP). Although large quantities of H2S are produced in marshes, only a small percentage escapes to the atmosphere. High latitude marshes emit less sulfur gases than temperate ones, but DMS still dominates. Mangrove-inhabited wetlands also emit less sulfur than temperate S. alterniflora marshes. Few data are available on sulfur gas emissions from freshwater wetlands. In most instances, sulfur emissions from temperate freshwater sites are low. However, some temperate and subtropical freshwater sites are similar in magnitude to those from marine wetlands which do not contain vegetation that produces DMSP. Emissions are low in Alaskan tundra but may be considerably higher in some bogs and fens.

Hines, Mark E.

1992-01-01

356

Sulfur 'Concrete' for Lunar Applications - Environmental Considerations  

NASA Technical Reports Server (NTRS)

Commercial use of sulfur concrete on Earth is well established, particularly in corrosive, e.g., acid and salt, environments. Having found troilite (FeS) on the Moon raises the question of using extracted sulfur as a lunar construction material, an attractive alternative to conventional concrete as it does not require water. For the purpose of this Technical Memorandum, it is assumed that lunar ore is mined, refined, and the raw sulfur processed with appropriate lunar regolith to form, for example, bricks. With this stipulation, it is then noted that the viability of sulfur concrete in a lunar environment, which is characterized by lack of an atmosphere and extreme temperatures, is not well understood. The work presented here evaluates two sets of small sulfur concrete samples that have been prepared using JSC-1 lunar simulant as an aggregate addition. One set was subjected to extended periods in high vacuum to evaluate sublimation issues, and the other was cycled between room and liquid nitrogen temperatures to investigate their subsequent mechanical integrity. Results are presented from both investigations, discussed, and put into the context of the lunar environment.

Grugel, R. N.

2008-01-01

357

An Aerosol Condensation Model for Sulfur Trioxide  

SciTech Connect

This document describes a model for condensation of sulfuric acid aerosol given an initial concentration and/or source of gaseous sulfur trioxide (e.g. fuming from oleum). The model includes the thermochemical effects on aerosol condensation and air parcel buoyancy. Condensation is assumed to occur heterogeneously onto a preexisting background aerosol distribution. The model development is both a revisiting of research initially presented at the Fall 2001 American Geophysical Union Meeting [1] and a further extension to provide new capabilities for current atmospheric dispersion modeling efforts [2]. Sulfuric acid is one of the most widely used of all industrial chemicals. In 1992, world consumption of sulfuric acid was 145 million metric tons, with 42.4 Mt (mega-tons) consumed in the United States [10]. In 2001, of 37.5 Mt consumed in the U.S., 74% went into producing phosphate fertilizers [11]. Another significant use is in mining industries. Lawuyi and Fingas [7] estimate that, in 1996, 68% of use was for fertilizers and 5.8% was for mining. They note that H{sub 2}SO{sub 4} use has been and should continue to be very stable. In the United States, the elimination of MTBE (methyl tertiary-butyl ether) and the use of ethanol for gasoline production are further increasing the demand for petroleum alkylate. Alkylate producers have a choice of either a hydrofluoric acid or sulfuric acid process. Both processes are widely used today. Concerns, however, over the safety or potential regulation of hydrofluoric acid are likely to result in most of the growth being for the sulfuric acid process, further increasing demand [11]. The implication of sulfuric acid being a pervasive industrial chemical is that transport is also pervasive. Often, this is in the form of oleum tankers, having around 30% free sulfur trioxide. Although sulfuric acid itself is not a volatile substance, fuming sulfuric acid (referred to as oleum) is [7], the volatile product being sulfur trioxide. Sulfate aerosols and mist may form in the atmosphere on tank rupture. From chemical spill data from 1990-1996, Lawuyi02 and Fingas [7] prioritize sulfuric acid as sixth most serious. During this period, they note 155 spills totaling 13 Mt, out of a supply volume of 3700 Mt. Lawuyi and Fingas [7] summarize information on three major sulfuric acid spills. On 12 February 1984, 93 tons of sulfuric acid were spilled when 14 railroad cars derailed near MacTier, Parry Sound, Ontario. On 13 December 1978, 51 railroad cars derailed near Springhill, Nova Scotia. One car, containing 93% sulfuric acid, ruptured, spilling nearly its entire contents. In July 1993, 20 to 50 tons of fuming sulfuric acid spilled at the General Chemical Corp. plant in Richmond, California, a major industrial center near San Francisco. The release occurred when oleum was being loaded into a nonfuming acid railroad tank car that contained only a rupture disk as a safety device. The tank car was overheated and this rupture disk blew. The resulting cloud of sulfuric acid drifted northeast with prevailing winds over a number of populated areas. More than 3,000 people subsequently sought medical attention for burning eyes, coughing, headaches, and nausea. Almost all were treated and released on the day of the spill. By the day after the release, another 5,000 people had sought medical attention. The spill forced the closure of five freeways in the region as well as some Bay Area Rapid Transit System stations. Apart from corrosive toxicity, there is the additional hazard that the reactions of sulfur trioxide and sulfuric acid vapors with water are extremely exothermic [10, 11]. While the vapors are intrinsically denser than air, there is thus the likelihood of strong, warming-induced buoyancy from reactions with ambient water vapor, water-containing aerosol droplets, and wet environmental surface. Nordin [12] relates just such an occurrence following the Richmond, CA spill, with the plume observed to rise to 300 m. For all practical purposes, sulfur trioxide was the constituent released from the heated tank

Grant, K E

2008-02-07

358

Sulfur copolymers for infrared optical imaging  

NASA Astrophysics Data System (ADS)

The development of organic polymers with low infrared absorption has been investigated as a possible alternative to inorganic metal oxide, semiconductor, or chalcogenide-based materials for a variety of optical devices and components, such as lenses, goggles, thermal imaging cameras and optical fibers. In principle, organic-based polymers are attractive for these applications because of their low weight, ease of processing, mechanical toughness, and facile chemical variation using commercially available precursors. Herein we report on the optical characterization of a new class of sulfur copolymers that are readily moldable, transparent above 500 nm, possess high refractive index (n > 1.8) and take advantage of the low infrared absorption of S-S bonds for potential use in the mid-infrared at 3-5 microns. These materials are largely made from elemental sulfur by an inverse vulcanization process; in the current study we focus on the properties of a chemically stable, branched copolymer of poly(sulfur-random-1,3-diisopropenylbenzene) (poly(S-r- DIB). Copolymers with elemental sulfur content ranging from 50% to 80% by weight were studied by UV-VIS spectroscopy, FTIR, and prism coupling for refractive index measurement. Clear correlation between material composition and the optical properties was established, confirming that the high polarizability of the sulfur atom leads to high refractive index while also maintaining low optical loss in the infrared.

Namnabat, S.; Gabriel, J. J.; Pyun, J.; Norwood, R. A.; Dereniak, E. L.; van der Laan, J.

2014-06-01

359

Development of enhanced sulfur rejection processes  

SciTech Connect

Research at Virginia Tech led to two complementary concepts for improving the removal of inorganic sulfur from much of the Eastern US coals. One controls the surface properties of coal pyrite (FeS[sub 2]) by electrochemical-.potential control, referred to as the Electrochemically Enhanced Sulfur Rejection (EESR) Process: The second controls the flotation of middlings, i.e., particles composed of pyrite with coal inclusions by using polymeric reagents to react with pyrite and convert the middlings to hydrophilic particles, and is termed the Polymer Enhanced Sulfur Rejection (PESR) Process. These new concepts are based on recent research establishing the two main reasons why flotation fails to remove more than about 50% of the pyritic sulfur from coal: superficial oxidization of liberated pyrite to form polysulfide oxidation products so that a part of the liberated pyrite floats with the coal; and hydrophobic coal inclusions in the middlings dominating their flotation so that the middlings also float with the coal. These new pyritic-sulfur rejection processes do not require significant modifications of existing coal preparation facilities, enhancing their adoptability by the coal industry. It is believed that they can be used simultaneously to achieve both free pyrite and locked pyrite rejection.

Yoon, R.H.; Luttrell, G.; Adel, G.; Richardson, P.E.

1993-03-23

360

Multiple sulfur isotopes fractionations associated with abiotic sulfur transformations in Yellowstone National Park geothermal springs  

PubMed Central

Background The paper presents a quantification of main (hydrogen sulfide and sulfate), as well as of intermediate sulfur species (zero-valent sulfur (ZVS), thiosulfate, sulfite, thiocyanate) in the Yellowstone National Park (YNP) hydrothermal springs and pools. We combined these measurements with the measurements of quadruple sulfur isotope composition of sulfate, hydrogen sulfide and zero-valent sulfur. The main goal of this research is to understand multiple sulfur isotope fractionation in the system, which is dominated by complex, mostly abiotic, sulfur cycling. Results Water samples from six springs and pools in the Yellowstone National Park were characterized by pH, chloride to sulfate ratios, sulfide and intermediate sulfur species concentrations. Concentrations of sulfate in pools indicate either oxidation of sulfide by mixing of deep parent water with shallow oxic water, or surface oxidation of sulfide with atmospheric oxygen. Thiosulfate concentrations are low (<6 ?mol L-1) in the pools with low pH due to fast disproportionation of thiosulfate. In the pools with higher pH, the concentration of thiosulfate varies, depending on different geochemical pathways of thiosulfate formation. The ?34S values of sulfate in four systems were close to those calculated using a mixing line of the model based on dilution and boiling of a deep hot parent water body. In two pools ?34S values of sulfate varied significantly from the values calculated from this model. Sulfur isotope fractionation between ZVS and hydrogen sulfide was close to zero at pH?sulfur is slightly heavier than hydrogen sulfide due to equilibration in the rhombic sulfur–polysulfide – hydrogen sulfide system. Triple sulfur isotope (32S, 33S, 34S) fractionation patterns in waters of hydrothermal pools are more consistent with redox processes involving intermediate sulfur species than with bacterial sulfate reduction. Small but resolved differences in ?33S among species and between pools are observed. Conclusions The variation of sulfate isotopic composition, the origin of differences in isotopic composition of sulfide and zero–valent sulfur, as well as differences in ?33S of sulfide and sulfate are likely due to a complex network of abiotic redox reactions, including disproportionation pathways. PMID:24959098

2014-01-01

361

Production of Lunar Concrete Using Molten Sulfur  

NASA Technical Reports Server (NTRS)

The United States has made a commitment to go back to the moon to stay in the early part of the next century. In order to achieve this objective it became evident to NASA that a Lunar Outpost will be needed to house scientists and astronauts who will be living on the moon for extended periods of time. A study has been undertaken by the authors and supported by NASA to study the feasibility of using lunar regolith with different binders such as molten sulfur, epoxy or hydraulic cement as a construction material for different lunar structures. The basic premise of this study is that it will be more logical and cost effective to manufacture lunar construction materials utilizing indigenous resources rather than transporting needed materials from earth. Lunar concrete (made from Hydraulic Cement and lunar soil) has been studied and suggested as the construction material of choice for some of the lunar projects. Unfortunately, its hydration requires water which is going to be a precious commodity on the moon. Therefore this study explores the feasibility of using binders other than hydraulic cement such as sulfur or epoxy with lunar regolith as a construction material. This report describes findings of this study which deals specifically with using molten sulfur as a binder for Lunar concrete. It describes laboratory experiments in which the sulfur to lunar soil simulant ratios by weight were varied to study the minimum amount of sulfur required to produce a particular strength. The compressive and tensile strengths of these mixes were evaluated. Metal and fiber glass fibers were added to some of the mixes to study their effects on the compressive and tensile strengths. This report also describes experiments where the sulfur is melted and mixed with the lunar regolith in a specially designed vacuum chamber. The properties of the produced concrete were compared to those of concrete produced under normal pressure.

Omar, Husam A.

1993-01-01

362

Application of a sodium sulfur cell with dynamic sulfur electrode to a battery system  

SciTech Connect

In this paper the construction and performance of a sodium sulfur battery system with dynamic sulfur electrodes are described. Three cells were first connected in parallel, then two such groups were connected in series. Each cell included a liquid sodium filled {beta}{double prime}-alumina tube and a system to feed liquid sulfur into the annular cathode. Low resistance graphite felt was tightly packed around the {beta}{double prime}-alumina tube. Sodium pentasulfide was removed from the sulfur electrode. The battery was operated automatically and stably changed and discharged in the two-phase region. The discharged energy was 4372 Wh (capacity 1170 Ah) during a continuous operation of 19.5 h. The discharge/charge energy efficiency of the battery was 82% at an averaged current density of 100 mA/cm{sup 2} and operating temperature of 350{degrees}C. The deviation of the cell current in a parallel chain was less than 7%, and this was induced by the difference in internal resistance. In the daily charge/discharge cycle, cell capacity with the dynamic sulfur electrode was 1.5 times higher than that with the static sulfur electrode using the same active surface of {beta}{double prime}-alumina, because the internal resistance of the former cell was constant regardless of cell capacity. This battery system with a dynamic sulfur electrode can be applied to energy storage systems, such as large scale load leveling systems, electric vehicle batteries, and solar energy systems.

Tokoi, H.; Takahashi, K.; Shimoyashiki, S. (Hitachi, Ltd., Energy Research Lab., 1168 Moriyama-cho, Hitachi, Ibaraki 316 (JP))

1992-01-01

363

Application of a sodium sulfur cell with dynamic sulfur electrode to a battery system  

NASA Astrophysics Data System (ADS)

The construction and performance of a sodium sulfur battery system with dynamic sulfur electrodes are described. Three cells were first connected in parallel, then two such groups were connected in series. Each cell included a liquid sodium-filled beta-double-prime-alumina tube and a system to feed liquid sulfur into the annular cathode. Low-resistance graphite felt was tightly packed around the beta-double-prime-alumina tube. Sodium pentasulfide was removed from the sulfur electrode. The battery was operated automatically and stably charged and discharged in the two-phase region. The discharged energy was 4372 Wh (capacity 1170 Ah) during a continuous operation of 19.5 h. The discharge/charge energy efficiency of the battery was 82 percent at an averaged current density of 100 mA/sq cm and operating temperature of 350 C. The deviation of the cell current in a parallel chain was less than 7 percent, and this was induced by the difference in internal resistance. In the daily charge/discharge cycle, cell capacity with the dynamic sulfur electrode was 1.5 times higher than that with the static sulfur electrode using the same active surface of beta-double-prime-alumina, because the internal resistance of the former cell was constant regardless of cell capacity. This battery system with a dynamic sulfur electrode can be applied to energy storage systems,such as large scale load leveling systems, electric vehicle batteries, and solar energy systems.

Tokoi, H.; Takahashi, K.; Shimoyashiki, S.

1992-01-01

364

Multiple sulfur isotopes and the evolution of Earth's surface sulfur cycle  

NASA Astrophysics Data System (ADS)

The distribution of sulfur isotopes in geological materials reveals information about Earth history and biogeochemical processes. Research during the last several decades has used sulfur isotope geochemistry as a tool to better understand microbial processes ( Harrison and Thode, 1958; Kaplan, 1975; Monster et al., 1979; Peck, 1959, 1962; Rees, 1973) and sediment diagenesis ( Berner, 1969, 1982; Canfield et al., 1993b). Earth historians also realized this potential, as there exists a rich record of environmental change within the sedimentary records ( Canfield and Teske, 1996; Claypool et al., 1980; Goodwin et al., 1976; Habicht et al., 2002; Kah et al., 2004; Monster et al., 1979; Shen et al., 2001; Strauss, 1993; Thode and Goodwin, 1983). These applications have championed the use of the two most abundant sulfur isotopes [ 32S and 34S], and provide a rich introduction to what the sulfur isotope record has to offer [see ( Canfield, 2004; Canfield and Raiswell, 1999)]. Within the last decade, this information has been supplemented by new data derived from the less abundant isotopes [ 33S and 36S]. The measurement of all four stable sulfur isotopes - multiple sulfur isotope geochemistry - has expanded our understanding of biological evolution and activity, atmospheric chemistry and transport, crustal recycling, and many more fields related to Earth surface processes [see ( Farquhar and Wing, 2003)]. Here, I present a review of recent works in multiple sulfur isotope geochemistry with a focus on results that inform our understanding of biogeochemical processes and Earth surface evolution.

Johnston, David T.

2011-05-01

365

Sulfur contents and sulfur-isotope compositions of thiotrophic symbioses in bivalve molluscs and vestimentiferan worms  

USGS Publications Warehouse

Total sulfur (S(TOT)), elemental sulfur (S??) and sulfur-isotope compositions (??34S) of marine animals were analyzed to determine whether these chemical characteristics could help distinguish animals with a sulfur-based, thiotrophic nutrition from animals whose nutrition is based on methanotrophy or on more normal consumption of phytoplankton-derived organic matter. The presence of S??was almost entirely confined to the symbiont-containing tissues of thiotrophs, but was sometimes undetectable in thiotrophic species where sulfide availability was probably low. When S??contents were subtracted, the remaining tissue-sulfur concentrations were similar for all nutritional groups. ??34S values were typically lower for thiotrophs than for other groups, although there was overlap in methanotroph and thiotroph values at some sites. Field evidence supported the existence of small to moderate (1 to 10???)34S fractionations in the uptake of sulfides and metabolism of thiosulfate. In general, a total sulfur content of >3% dry weight, the presence of elemental sulfur, and ??34S values less than + 5??? can be used to infer a thiotrophic mode of nutrition.

Vetter, R.D.; Fry, B.

1998-01-01

366

Identification of Seasonal Variations in Volatile Sulfur Compound Formation and Emission From the Secondary Treatment System at a Large Wastewater Treatment Plant  

Technology Transfer Automated Retrieval System (TEKTRAN)

Offensive odors associated with gaseous emissions from wastewater treatment plants (WWTPs) are a nuisance to residential communities that exist in close proximity to these facilities. The purpose of this study was to identify, quantify and determine source locations of significant volatile sulfur c...

367

CE IGCC Repowering plant sulfuric acid plant. Topical report, June 1993  

SciTech Connect

A goal of the CE IGCC Repowering project is to demonstrate a hot gas clean-up system (HGCU), for the removal of sulfur from the product gas stream exiting the gasifier island. Combustion Engineering, Inc. (ABB CE) intends to use a HGCU developed by General Electric Environmental Services (GEESI). The original design of this system called for the installation of the HGCU, with a conventional cold gas clean-up system included as a full-load operational back-up. Each of these systems removes sulfur compounds and converts them into an acid off-gas. This report deals with the investigation of equipment to treat this off-gas, recovering these sulfur compounds as elemental sulfur, sulfuric acid or some other form. ABB CE contracted ABB Lummus Crest Inc. (ABB LCI) to perform an engineering evaluation to compare several such process options. This study concluded that the installation of a sulfuric acid plant represented the best option from both a technical and economic point of view. Based on this evaluation, ABB CE specified that a sulfuric acid plant be installed to remove sulfur from off-gas exiling the gas clean-up system. ABB LCI prepared a request for quotation (RFQ) for the construction of a sulfuric acid production plant. Monsanto Enviro-Chem Inc. presented the only proposal, and was eventually selected as the EPC contractor for this system.

Chester, A.M.

1993-12-01

368

Lithium-sulfur hexafluoride magnetohydrodynamic power system  

SciTech Connect

A method is described to operate a two-phase flow magnetohydrodynamic electric power generation system with liquid lithium and gaseous sulfur-hexafluoride flowing through a diverging channel, with side electrodes to remove the electric current generated in the flowing liquid lithium, across the applied magnetic field that is perpendicular to both the flow velocity and electrodes. Sulfur-hexafluoride is dispersed in the form of small bubbles and reacts with liquid lithium that forms a continuous phase to conduct the current between the electrodes so as to produce a near isothermal two-phase flow mixture and provides for an expansion of lithium across the magnetic field in the generator.

Dobran, F.

1987-02-24

369

Method of making a sodium sulfur battery  

DOEpatents

A method of making a portion of a sodium sulfur battery is disclosed. The battery portion made is a portion of the container which defines the volume for the cathodic reactant materials which are sulfur and sodium polysulfide materials. The container portion is defined by an outer metal casing with a graphite liner contained therein, the graphite liner having a coating on its internal diameter for sealing off the porosity thereof. The steel outer container and graphite pipe are united by a method which insures that at the operating temperature of the battery, relatively low electrical resistance exists between the two materials because they are in intimate contact with one another.

Elkins, Perry E. (Santa Ana, CA)

1981-01-01

370

la biolixiviation des minerais sulfurs La biolixiviation  

E-print Network

'intérêt économique Biolixiviation de la pyrite En milieu naturel, le minéral sulfuré dont la dégrada- tion par biolixiviation la plus fréquemment observée est la pyrite. De formule chimique FeS2, la pyrite est le sulfure contact de l'air, la réaction d'oxydation de la pyrite obéit à l'équation suivante : FeS2 + 14 Fe3+ + 8 H2

Paris-Sud XI, Université de

371

Ion chromatographic determination of sulfur in fuels  

NASA Technical Reports Server (NTRS)

The sulfur content of fuels was determined using an ion chromatograph to measure the sulfate produced by a modified Parr bomb oxidation. Standard Reference Materials from the National Bureau of Standards, of approximately 0.2 + or - 0.004% sulfur, were analyzed resulting in a standard deviation no greater than 0.008. The ion chromatographic method can be applied to conventional fuels as well as shale-oil derived fuels. Other acid forming elements, such as fluorine, chlorine and nitrogen could be determined at the same time, provided that these elements have reached a suitable ionic state during the oxidation of the fuel.

Mizisin, C. S.; Kuivinen, D. E.; Otterson, D. A.

1978-01-01

372

Electrochemical behavior of graphite in electrolyte of sulfuric and acetic acid  

Microsoft Academic Search

Electrochemical formation of graphite intercalation compounds (GICs) has been studied in the electrolyte with mixed sulfuric acid and acetic acid. The results show that, with addition of acetic acid, GICs can be synthesized in the electrolyte with sulfuric acid concentration as low as 3.6M, even though no GIC is formed in pure acetic acid. The stage structure of the synthesized

F. Kang; T.-Y. Zhang; Y. Leng

1997-01-01

373

Surface Science 415 (1998) 2936 Structural studies of sulfur-passivated GaAs (100)  

E-print Network

Abstract We present the results of Auger electron spectroscopy (AES), low-energy electron diffraction (LEED) and atomic force microscopy (AFM) analysis of sulfur-passivating layers on the GaAs (100) surface. The Ga-based compounds. We prepared the inorganic sulfur-passivated GaAs(100) surfaces with a wet chemical treatment

Zhang, Yanchao

374

Enhanced cycling stability of lithium sulfur batteries using sulfur-polyaniline-graphene nanoribbon composite cathodes.  

PubMed

A hierarchical nanocomposite material of graphene nanoribbons combined with polyaniline and sulfur using an inexpensive, simple method has been developed. The resulting composite, characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron microscopy, and X-ray diffraction analysis, has a good rate performance and excellent cycling stability. The synergistic combination of electrically conductive graphene nanoribbons, polyaniline, and sulfur produces a composite with high performance. The method developed here is practical for the large-scale development of cathode materials for lithium sulfur batteries. PMID:25141233

Li, Lei; Ruan, Gedeng; Peng, Zhiwei; Yang, Yang; Fei, Huilong; Raji, Abdul-Rahman O; Samuel, Errol L G; Tour, James M

2014-09-10

375

Evaluation of sulfur-reducing microorganisms for organic desulfurization  

SciTech Connect

Because a substantial portion of the sulfur in Illinois coal is organically bound sulfur, microbial desulfurization of sulfidic and thiophenic functionalities holds great potential for complementing pyritic sulfur removal. The principal goals of their project are: to obtain anaerobic microbial cultures that produce H{sub 2}S from compounds representative of the organosulfur functionalities in coal; to optimize this activity; to evaluate the effectiveness of using these cultures to remove organic sulfur from Illinois coal. Their immediate objectives for this year are the following: to obtain additional cultures from coal mine waste and municipal sewage sludge, two environments previously unexplored by their laboratory; to continue optimizing activity in cultures that desulfurize model compounds, including identification of individual microbial species; to expand coal desulfurization experiments to include additional coals; and, to address the recently discovered problem of sulfide sorbing to coal. This quarter they installed a Coy Anaerobic Chamber, which will be used for isolation and manipulation of anaerobic cultures. Additionally, the anoxic atmosphere within the chamber makes it an ideal location for grinding and sieving a sample of North Dakota lignite and IBC-101, both of which will be used in desulfurization and sulfide sorption experiments. Further experiments with mixed anaerobic cultures that reductively degrade dibenzyldisulfide (DBDS) have demonstrated that reduction of DBDS does not depend on co-reduction of sulfate. 34 refs., 1 fig., 2 tab.

Miller, K.W. (Illinois State Univ., Normal, IL (USA). Dept. of Biological Sciences)

1990-01-01

376

Heterogeneous Interaction of Peroxyacetyl Nitrate on Liquid Sulfuric Acid  

NASA Technical Reports Server (NTRS)

The uptake of peroxyacetyl nitrate (PAN) on liquid sulfuric acid surfaces has been investigated using a fast-flow reactor coupled to a chemical ionization mass spectrometer. PAN was observed to be reversibly adsorbed on sulfuric acid.

Zhang, Renyi; Leu, Ming-Taun

1996-01-01

377

40 CFR 60.173 - Standard for sulfur dioxide.  

Code of Federal Regulations, 2013 CFR

...NEW STATIONARY SOURCES Standards of Performance for Primary Zinc Smelters § 60.173 Standard for sulfur dioxide. ...more than 10 percent of the sulfur initially contained in the zinc sulfide ore concentrates will be considered as a roaster...

2013-07-01

378

40 CFR 60.173 - Standard for sulfur dioxide.  

Code of Federal Regulations, 2014 CFR

...NEW STATIONARY SOURCES Standards of Performance for Primary Zinc Smelters § 60.173 Standard for sulfur dioxide. ...more than 10 percent of the sulfur initially contained in the zinc sulfide ore concentrates will be considered as a roaster...

2014-07-01

379

40 CFR 60.173 - Standard for sulfur dioxide.  

Code of Federal Regulations, 2012 CFR

...NEW STATIONARY SOURCES Standards of Performance for Primary Zinc Smelters § 60.173 Standard for sulfur dioxide. ...more than 10 percent of the sulfur initially contained in the zinc sulfide ore concentrates will be considered as a roaster...

2012-07-01

380

Sulfur Dioxide Inhibition of Photosynthesis in Isolated Spinach Chloroplasts  

PubMed Central

Photosynthetic oxygen evolution by isolated spinach (Spinacia oleracea L.) chloroplasts approached complete inhibition in the presence of a 5 mm concentration of sulfur dioxide. A similar inhibition was observed in the presence of equimolar concentrations of bisulfite ions, suggesting a parallel mode of action. In contrast, an equimolar concentration of sulfite ions was markedly less inhibitory and sulfate ions caused negligible inhibition of apparent photosynthesis. The mode of action of sulfur dioxide and related sulfur anions in inhibiting photosynthesis was found to be essentially independent of direct hydrogen-ion effects. Supplements of inorganic pyrophosphate lessened the inhibition of oxygen evolution caused by sulfur dioxide and the sulfur anions. Sulfur dioxide and the sulfur anions were almost equally effective in inhibiting cyclic and noncyclic photophosphorylation in chloroplast suspensions. However, the extent of the inhibition of these photosynthetic reactions does not appear sufficient to account for the inhibition of photosynthetic oxygen evolution by sulfur dioxide. PMID:16659319

Silvius, John E.; Ingle, Morris; Baer, Charles H.

1975-01-01

381

Supercritical thermodynamics of sulfur and nitrogen species  

SciTech Connect

Significant opportunity exists for the application of supercritical fluid (SCF) technology to coal processing, both for pretreatment of high sulfur coals, as well as liquefaction and treatment of coal liquids. Supercritical fluids are attractive solvents for a variety of coal processing applications because of their unusual solvating and mass transfer properties. Solubility studies have been carried out for a number of model coal and coal-liquid compounds, primarily in pure supercritical fluids. We are extending this database of model coal compound equilibria using modern techniques that have the advantage of being much more rapid than traditional techniques. Cosolvent effects on solubility are being investigated over a variety of solvent properties. In addition, specific molecular interactions are being investigated through spectroscopic techniques. The resulting data is being used to develop a chemical-physical equation of state (EOS) model of SCF solution with meaningful parameters. The equation of state will be used to predict solubility behavior, which will permit the design and tailoring of SCF cosolvent systems for specific coal processing applications.

Eckert, C.A.

1991-01-01

382

Gas phase reaction of sulfur trioxide with water vapor  

Microsoft Academic Search

Sulfur trioxide (SO3) has long been known to react with water to produce sulfuric acid (H2S04). It has been commonly assumed that the gas phase reaction in the Earth`s atmosphere between SO3 and water vapor to produce sulfuric acid vapor is an important step in the production of sulfuric acid aerosol particles. The kinetics of the gas phase reaction of

C. E. Kolb; M. J. Molina; J. T. Jayne; R. F. Meads; D. R. Worsnop; A. A. Viggiano

1994-01-01

383

Sodium--sulfur battery. [design of internal seal  

Microsoft Academic Search

A new seal for a sodium--sulfur battery is disclosed. The sodium--sulfur battery uses two cylindrical containers for containing sulfur and sodium in molten states and a beta--alumina electrolyte tube located primarily within the sulfur container. The battery disclosed includes a novel header, preferably a metal header, between the containers and through which the beta--alumina tube extends. In order to prevent

Dubin

1978-01-01

384

An Approach for Measuring the Sorptive Behavior of Odorants Using a Multifunction Thermal Desorber Unit: Preliminary Tests on Reduced Sulfur Compounds  

PubMed Central

In this study, the sorptive behavior of reduced sulfur compounds (RSC) was investigated using a combination of thermal desorber (TD) unit and gas chromatography (GC). To examine the sorptive properties of RSC on textile materials, two types of experiments were conducted under experimental conditions favorable for sorptive processes. In all the experiments, gaseous standards of hydrogen sulfide, methanethiol, dimethyl sulfide, and dimethyl disulfide were supplied to initiate the adsorption processes on textile pieces. The textile pieces were then forced to release those adsorbed RSC under a fixed condition. It was found that the extent of adsorption, if evaluated quantitatively, occurred at approximately 1/1000 to 1/100 of the level of RSC standards supplied originally to induce adsorption. It also indicated that RSC adsorption was affected very sensitively by the initial exposure durations to induce RSC adsorption with an exponential decrease in relative recovery (RR) values with increasing exposure time. The relative sorptive patterns, when compared between different RSCs, were affected most sensitively by such factors as molecular weight and/or physical contact conditions.

Kim, Ki-Hyun; Choi, Ye-Jin; Yang, Hye-Soon; Joo, Sang-Woo

2008-01-01

385

Sulfur isotopic ratio of DMS and DMSP from Lake Kinneret  

NASA Astrophysics Data System (ADS)

Volatile Organic sulfur compounds (VOSC) such as dimethylsulfide (DMS) are an important source of biogenic sulfur to the atmosphere. The main precursor of DMS is dimethylsulfoniopropionate (DMSP), a common osmolyte in marine algae. Atmospheric release of VOS compounds contributes to the formation of sulfate aerosols. The latter are of global importance due to their role as cloud-condensation nuclei. VOSC are abundant in terrestrial environments as well and may be involved in important biogeochemical cycles. In lake sediments, another mechanism for the formation of DMS by H2S methylation may be important. The 34S/32S ratio (d34S values) of DMSP of marine surface water around the globe is very homogeneous ranging between +18.9 o to +20.3 o and the fractionation between DMSP and DMS is < +1 o (Amrani et al. 2013). The ?34S values of DMS and other VOSC in sediments should be 34S depleted, similar to its H2S precursor (Oduro et al., 2011). Our goal was to quantify the benthic DMS and DMSP emissions from the sediments of warm monomictic Lake Kinneret relative to their formation by surface water algae by using sulfur isotope ratios. Water column samples and sediment samples from Lake Kinneret were purged and trap in order to extract the VOSC and then introduced to a GC/MC-ICPMS for isotopic measurements (Amrani et al. 2013). The ?34S of DMSP in the water and sediment columns of Lake Kinneret a mesotrophic monomictic lake were measured. Our preliminary results show ?34S values for DMSP ranged between +10.3 o and +13.4 o in the water column. The sulfate ?34S values ranged between +12.6 o to +14.9 o. ?34S -DMSP in the sediment column showed similar values between +9.4 o and +13.0 o, indicating a similar sulfur source. Similar ?34S values obtain for other VOSC such as ethanethiol that contributes significantly to the VOSC of Lake Kinneret sediments. Amrani, A., W. Said-Ahmad,Y. Shaked, and R. P. Kiene. 2013. Sulfur isotopes homogeneity of oceanic DMSP and DMS. PNAS 110(46):18413-18418. Oduro, H., Kamyshny, A. Jr.,W. Guo, and J. Farquhar. 2011. Multiple sulfur isotopes analysis of volatile organic sulfur compounds and their sulfonium precursors in marine coastal environments. Marine Chemistry 124:78-89.

Sela-Adler, Michal; Said-Ahmad, Ward; Eckert, Werner; Kamyshny, Alexey; Sivan, Orit; Amrani, Alon

2014-05-01

386

An improved intermolecular potential for sulfur hexafluoride  

SciTech Connect

Second virial coefficient data and viscosity were used to evaluate effective isotropic intermolecular potential functions proposed in the literature for sulfur hexafluoride. It was found that none of the potentials could predict the properties simultaneously. We have constructed a Morse--Morse--Spline--van der Waals (MMSV) potential which satisfactorily correlates second virial coefficient and viscosity data at the same time.

Aziz, R.A.; Slaman, M.J. (Department of Physics, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1 (US)); Taylor, W.L.; Hurly, J.J. (EG G Mound Applied Technologies, Inc., Miamisburg, Ohio 45343 (US) Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221 (US))

1991-01-15

387

SULFUR DIOXIDE OXIDATION REACTIONS IN AQUEOUS SOLUTIONS  

EPA Science Inventory

This is the final report on a three year project to study the kinetics and mechanisms of some 105 reactions involving the aqueous oxidation of sulfur dioxide and nitrogen oxides in mixed catalyst-oxidant systems at low pH (0-3). The 105 systems involve six redox reaction types: S...

388

Massive Loss of Sulfur in HIV Infection  

Microsoft Academic Search

Skeletal muscle tissue from SIV-infected macaques was previously found to contain abnormally high sulfate and low glutathione levels indicative of an excessive cysteine catabolism. We now confirm the peripheral tis- sue as a site of massive cysteine catabolism in HIV infection and have determined the urinary loss of sulfur per time unit. The comparison of the sulfate concentrations of the

Raoul Breitkreutz; Stefanie Holm; Nicole Pittack; Matthias Beichert; Alexander Babylon; Junji Yodoi; Wulf Droge

2000-01-01

389

Charles H. Winston and Confederate Sulfuric Acid.  

ERIC Educational Resources Information Center

Describes the invention and use of a sulfuric acid chamber by Charles Henry Winston during the Civil War. This invention helped supply munitions for the South. Winston, who was President of the Richmond Female Institute in Virginia, constructed the chamber at his farm and was granted a patent by the Confederate Patent Office in 1863. (PVD)

Riethmiller, Steven

1995-01-01

390

Sulfuric acid thermoelectrochemical system and method  

DOEpatents

A thermoelectrochemical system in which an electrical current is generated between a cathode immersed in a concentrated sulfuric acid solution and an anode immersed in an aqueous buffer solution of sodium bisulfate and sodium sulfate. Reactants consumed at the electrodes during the electrochemical reaction are thermochemically regenerated and recycled to the electrodes to provide continuous operation of the system.

Ludwig, Frank A. (Rancho Palos Verdes, CA)

1989-01-01

391

Nitrosyl sulfuric acid and stratospheric aerosols  

Microsoft Academic Search

From information found in the atmospheric and chemical literature, we propose that nitrosyl sulfuric acid (NSA), NOHSO4, may play an important role in stratospheric chemistry. In one study, NSA was observed as a slurry of crystals in about a third of the aerosol particles collected between 15 and 20 km. From the chemical literature, we find that NSA is formed

Joel D. Burley; H. S. Johnston

1992-01-01

392

Optimization studies in sulfuric acid production  

Microsoft Academic Search

Current legislation imposes tighter restrictions to reduce the impact of process industry on environment. This work presents the dynamic simulation and optimization results for an existing sulfuric acid plant. Operational problems may occur when the process is disturbed due to production rate changes or catalyst deactivation, the non-linear response of the plant leading to sustained oscillations. Since the plant is

Anton A. Kiss; Costin S. Bildea; Peter J. T. Verheijen

2006-01-01

393

46 CFR 148.04-20 - Sulfur.  

Code of Federal Regulations, 2010 CFR

...the bilges; any chinking necessary in the way of tank tops or bilges must be made of noncombustible material. (c) Cowl ventilators serving the hold into which sulfur is being loaded or discharged must be opened to provide circulation of air. (d)...

2010-10-01

394

Intestinal metabolism of sulfur amino acids  

Technology Transfer Automated Retrieval System (TEKTRAN)

The gastrointestinal tract (GIT) is a metabolically significant site of sulfur amino acid (SAA) metabolism in the body and metabolizes approx. 20% of the dietary methionine intake that is mainly transmethylated to homocysteine and transsulfurated to cysteine. The GIT accounts for approx. 25% of the ...

395

LABORATORY MEASUREMENT OF SULFUR DIOXIDE DEPOSITION VELOCITIES  

EPA Science Inventory

Measurements of sulfur dioxide deposition velocities have been carried out in the laboratory with the use of a cylindrical flow reaction. Analysis of data from these experiments was performed with models that specifically account for diffusive transport in the system. Consequentl...

396

SOLID SORBENT FOR COLLECTING ATMOSPHERIC SULFUR DIOXIDE  

EPA Science Inventory

A solid sorbent for collecting atmospheric SO2 was evaluated as part of an overall effort to develop a replacement method for the West-Gaeke method presently used to measure 24-hour ambient sulfur dioxide concentrations in ambient air. Research showed that a solid sorbent, consis...

397

Sulfuric acid spills in marine accidents  

SciTech Connect

Concentrated sulfuric acid and oleum are among the most potentially hazardous chemicals routinely transported in bulk quantities on US and international waterways. Conceivably, during a marine mishap, tons of sulfuric acid could be abruptly released into the water, and the consequences of such a spill could be detrimental to man and the environment. Several acid spill scenarios are briefly described, and the results from laboratory experiments designed to simulate two different types of acid spill accidents are reported. It is shown that the convective mixing of concentrated sulfuric acid with water can adequately be described by a mathematical model which takes into account the variation of the buoyancy force arising from changes in acid concentration and released heat of dilution. A value of 0.21 is determined to be the entrainment parameter for the mixing of sulfuric acid with water. For oleum spills in which acid aerosol formation is a potential safety hazard, a conservative estimate of less than one-tenth of a percent is obtained for the amount of airborne acid under most accident conditions. The fraction of airborne acid, however, decreases very rapidly with increasing release depth below water surfaces. The acid aerosols exhibit a well-defined log-normal particle-size distribution with peak diameter varying from 0.1 to 0.6 ..mu..m (at 70% R.H.) depending upon release depth. This is well within the respirable particle size range.

Tang, I N; Wong, W T; Munkelwitz, H R; Flessner, M F

1980-07-01

398

EFFECTS OF SULFURIC ACID AEROSOLS ON VEGETATION  

EPA Science Inventory

A continuous flow system for exposing plants to submicron aerosols of sulfuric acid has been developed and an operational model has been constructed. Exposure chambers have been designed to allow simultaneous exposures of the same plant to aerosol and control environments. All su...

399

THE MECHANISM OF SULFUR DIOXIDE INITIATED BRONCHOCONSTRICTION  

EPA Science Inventory

Atmospheric sulfur oxides exist in chemically complex particulates of the respirable size range. Inhalation of these particulates represents a potential health hazard. This report provides the results of a series of experiments into the uptake of sulfate salts by the lung, the in...

400

Development of enhanced sulfur rejection processes  

SciTech Connect

Research at Virginia Tech led to the development of two complementary concepts for improving the removal of inorganic sulfur from many eastern U.S. coals. These concepts are referred to as Electrochemically Enhanced Sulfur Rejection (EESR) and Polymer Enhanced Sulfur Rejection (PESR) processes. The EESR process uses electrochemical techniques to suppress the formation of hydrophobic oxidation products believed to be responsible for the floatability of coal pyrite. The PESR process uses polymeric reagents that react with pyrite and convert floatable middlings, i.e., composite particles composed of pyrite with coal inclusions, into hydrophilic particles. These new pyritic-sulfur rejection processes do not require significant modifications to existing coal preparation facilities, thereby enhancing their adoptability by the coal industry. It is believed that these processes can be used simultaneously to maximize the rejection of both well-liberated pyrite and composite coal-pyrite particles. The project was initiated on October 1, 1992 and all technical work has been completed. This report is based on the research carried out under Tasks 2-7 described in the project proposal. These tasks include Characterization, Electrochemical Studies, In Situ Monitoring of Reagent Adsorption on Pyrite, Bench Scale Testing of the EESR Process, Bench Scale Testing of the PESR Process, and Modeling and Simulation.

Yoon, R.H.; Luttrell, G.H.; Adel, G.T.; Richardson, P.E.

1996-03-01

401

Sulfur Isotopic Composition of Cenozoic Seawater Sulfate  

E-print Network

over one to several millions of years, indicating that changes in the burial rate of pyrite sulfur with 34 S values ap- proximately equal to that of seawater, and pyrite sulfide with a large isotopic fraction- ation signature [for example, modern 34 S values of pyrites average about ­20 per mil (7

Paytan, Adina

402

High-Sulfur Coal and Acidic Water  

NSDL National Science Digital Library

In this video, a geologist measures the pH of water after high-sulfur coal from a Kentucky coal mine has been added to it. This test demonstrates that the sulfate salts found on the coal’s surface cause the water to become much more acidic.

Ket

2011-01-11

403

Is There an Environmental Kuznets Curve for Sulfur?  

Microsoft Academic Search

Most existing estimates of the environmental Kuznets curve (EKC) for sulfur, which use samples of mainly high-income countries, indicate a maximum emissions turning point at middle to lower high-income levels of GDP per capita. We use a larger and more globally representative sample than previous sulfur EKC studies. We find that sulfur emissions per capita are a monotonic function of

David I. Stern; Michael S. Common

2001-01-01

404

A New Use for High-Sulfur Coal  

NASA Technical Reports Server (NTRS)

New process recovers some of economic value of high-sulfur coal. Although high-sulfur content is undesirable in most coal-utilization schemes (such as simple burning), proposed process prefers high-sulfur coal to produce electrical power or hydrogen. Potential exists for widespread application in energy industry.

Lawson, D. D.; England, C.

1982-01-01

405

FEASIBILITY OF PRODUCING ELEMENTAL SULFUR FROM MAGNESIUM SULFITE  

EPA Science Inventory

The report gives results of a study to extend potential applications of MgO flue gas desulfurization processes by allowing the sulfur to be recovered as elemental sulfur as well as sulfuric acid. The study considered the feasibility of combining the exothermic SO2 reduction react...

406

Sodium--sulfur electric cell. [P and Se possible cathodes  

Microsoft Academic Search

The invention relates to a new structure for a sodium--sulfur cell. Such a cell comprises a cathode tank containing sulfur, an electrolyte tube closed at its lower end containing sodium and immersed in sulfur, a sodium anode tank, and a ceramic support holding the tank and the tube. The cathode tank is fitted with graphite felt washers to ensure cathode

G. Desplanches; Y. Lazennec; A. Wicker

1977-01-01

407

40 CFR 52.57 - Control strategy: Sulfur oxides.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Control strategy: Sulfur oxides. 52.57 Section 52.57 Protection... § 52.57 Control strategy: Sulfur oxides. (a) The requirements of Subpart...maintenance of the national standards for sulfur oxides in the vicinity of the Widows...

2013-07-01

408

40 CFR 52.57 - Control strategy: Sulfur oxides.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Control strategy: Sulfur oxides. 52.57 Section 52.57 Protection... § 52.57 Control strategy: Sulfur oxides. (a) The requirements of Subpart...maintenance of the national standards for sulfur oxides in the vicinity of the Widows...

2010-07-01

409

40 CFR 52.2780 - Control strategy for sulfur oxides.  

Code of Federal Regulations, 2012 CFR

... false Control strategy for sulfur oxides. 52.2780 Section 52.2780 Protection...52.2780 Control strategy for sulfur oxides. (a) The requirements of subpart...ambient air quality standards for sulfur oxides on the island of St. Croix....

2012-07-01

410

40 CFR 52.57 - Control strategy: Sulfur oxides.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Control strategy: Sulfur oxides. 52.57 Section 52.57 Protection... § 52.57 Control strategy: Sulfur oxides. (a) The requirements of Subpart...maintenance of the national standards for sulfur oxides in the vicinity of the Widows...

2011-07-01

411

40 CFR 52.57 - Control strategy: Sulfur oxides.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Control strategy: Sulfur oxides. 52.57 Section 52.57 Protection... § 52.57 Control strategy: Sulfur oxides. (a) The requirements of Subpart...maintenance of the national standards for sulfur oxides in the vicinity of the Widows...

2012-07-01

412

40 CFR 52.57 - Control strategy: Sulfur oxides.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Control strategy: Sulfur oxides. 52.57 Section 52.57 Protection... § 52.57 Control strategy: Sulfur oxides. (a) The requirements of Subpart...maintenance of the national standards for sulfur oxides in the vicinity of the Widows...

2014-07-01

413

World sulfur production: As of Jan. 1, 1994  

SciTech Connect

The article consists of a table which lists company and location, source of sulfur, type of process used, design capacity, and sulfur production for 42 countries. Sources of sulfur include refinery gases, natural gas, acid gases, crude oil, shale gas, oil sands, coke oven gas, and hydrogen sulfide.

Not Available

1994-06-13

414

Reclamation of Elemental Sulfur from Flue Gas Biodesulfurization Waste Sludge  

Microsoft Academic Search

Perchloroethylene (PCE) extraction was used to reclaim elemental sulfur from flue gas biodesulfurization sludge. The sludge was generated from a biodesulfurization system that concurrently treated the flue gas scrubbing solution and wastewater of citric acid production. The sludge contained approximately 40–60% elemental sulfur; other components included flue gas dust, biomass, inorganic salts, and flocculants. The sulfur was extracted with PCE

Chengwen Wang; Yujue Wang; Yanqi Zhang; Qi Zhao; Ran Wang; Wang Chen; Elisabeth Gilmore; Peter Adams; Lester Lave; Huabo Duan; Weifeng Jia; Jinhui Li; Violeta Mugica; Sara Hernandez; Miguel Torres; Rocio García; Antton Melendez; Estibaliz García; Pedro Carnicer; Egoitz Pena; Miren Larrion; Juan Legarreta; Cristina Gutierrez-Canas; Parikhit Sinha; William Schew; Aniket Sawant; Kyle Kolwaite; Sarah Strode; Stephanie Weber; Jill Engel-Cox; Raymond Hoff; Ana Prados; Hai Zhang; Valerie Garcia; Kristen Foley; Edith Gego; David Holland; S. Rao; Sundar Christopher; Pawan Gupta; Christian Murray; Frederick Lipfert; Jung-Nan Hsu; Hsunling Bai; Shou-Nan Li; Chuen-Jinn Tsai

2010-01-01

415

ReaxFF molecular dynamics simulations on lithiated sulfur cathode materials.  

PubMed

Sulfur is a very promising cathode material for rechargeable energy storage devices. However, sulfur cathodes undergo a noticeable volume variation upon cycling, which induces mechanical stress. In spite of intensive investigation of the electrochemical behavior of the lithiated sulfur compounds, their mechanical properties are not very well understood. In order to fill this gap, we developed a ReaxFF interatomic potential to describe Li-S interactions and performed molecular dynamics (MD) simulations to study the structural, mechanical, and kinetic behavior of the amorphous lithiated sulfur (a-LixS) compounds. We examined the effect of lithiation on material properties such as ultimate strength, yield strength, and Young's modulus. Our results suggest that with increasing lithium content, the strength of lithiated sulfur compounds improves, although this increment is not linear with lithiation. The diffusion coefficients of both lithium and sulfur were computed for the a-LixS system at various stages of Li-loading. A grand canonical Monte Carlo (GCMC) scheme was used to calculate the open circuit voltage profile during cell discharge. The Li-S binary phase diagram was constructed using genetic algorithm based tools. Overall, these simulation results provide insight into the behavior of sulfur based cathode materials that are needed for developing lithium-sulfur batteries. PMID:25529209

Islam, Md Mahbubul; Ostadhossein, Alireza; Borodin, Oleg; Yeates, A Todd; Tipton, William W; Hennig, Richard G; Kumar, Nitin; van Duin, Adri C T

2015-02-01

416

Enhanced performance of lithium sulfur battery with polypyrrole warped mesoporous carbon/sulfur composite  

NASA Astrophysics Data System (ADS)

A sulfur cathode is designed with three-dimensional (3D) cubic mesoporous carbon CMK-8 as the matrix of sulfur, and polypyrrole (PPY) as the wrapping layer. CMK-8 provides perfect 3D conductive network. Furthermore, PPY is coated onto the surface of CMK-8/sulfur (CMK-8/S) composite to inhibit the migration of lithium polysulfide and offer better lithium ion conductive channels. The microstructure and electrochemical performance of the PPY@CMK-8/sulfur (PPY@CMK-8/S) cathode are investigated systematically. The results show that PPY layer with about 50 nm thickness is coated uniformly on the surface of CMK-8/S. The Li-S battery with PPY@CMK-8/S as cathode material presents a discharge capacity of 937.8 mAh g-1 at 20 cycles and is stabilized at about 860 mAh g-1 after 100 cycles at 0.2C.

Ma, Guoqiang; Wen, Zhaoyin; Jin, Jun; Lu, Yan; Rui, Kun; Wu, Xiangwei; Wu, Meifen; Zhang, Jingchao

2014-05-01

417

40 CFR 52.1881 - Control strategy: Sulfur oxides (sulfur dioxide).  

Code of Federal Regulations, 2013 CFR

...remove sulfur oxides. (iii) Fossil fuel means natural gas, refinery...from such materials. (iv) Fossil fuel-fired steam generating unit...used in the process of burning fossil fuel for the purpose of producing...

2013-07-01

418

40 CFR 52.1881 - Control strategy: Sulfur oxides (sulfur dioxide).  

Code of Federal Regulations, 2010 CFR

...remove sulfur oxides. (iii) Fossil fuel means natural gas, refinery...from such materials. (iv) Fossil fuel-fired steam generating unit...used in the process of burning fossil fuel for the purpose of producing...

2010-07-01

419

40 CFR 52.1881 - Control strategy: Sulfur oxides (sulfur dioxide).  

Code of Federal Regulations, 2012 CFR

...remove sulfur oxides. (iii) Fossil fuel means natural gas, refinery...from such materials. (iv) Fossil fuel-fired steam generating unit...used in the process of burning fossil fuel for the purpose of producing...

2012-07-01

420

40 CFR 52.1881 - Control strategy: Sulfur oxides (sulfur dioxide).  

Code of Federal Regulations, 2011 CFR

...remove sulfur oxides. (iii) Fossil fuel means natural gas, refinery...from such materials. (iv) Fossil fuel-fired steam generating unit...used in the process of burning fossil fuel for the purpose of producing...

2011-07-01

421

40 CFR 52.1881 - Control strategy: Sulfur oxides (sulfur dioxide).  

Code of Federal Regulations, 2014 CFR

...remove sulfur oxides. (iii) Fossil fuel means natural gas, refinery...from such materials. (iv) Fossil fuel-fired steam generating unit...used in the process of burning fossil fuel for the purpose of producing...

2014-07-01

422

Process for removing sulfur from sulfur-containing gases: high calcium fly-ash  

DOEpatents

The present disclosure relates to improved processes for treating hot sulfur-containing flue gas to remove sulfur therefrom. Processes in accordance with the present invention include preparing an aqueous slurry composed of a calcium alkali source and a source of reactive silica and/or alumina, heating the slurry to above-ambient temperatures for a period of time in order to facilitate the formation of sulfur-absorbing calcium silicates or aluminates, and treating the gas with the heat-treated slurry components. Examples disclosed herein demonstrate the utility of these processes in achieving improved sulfur-absorbing capabilities. Additionally, disclosure is provided which illustrates preferred configurations for employing the present processes both as a dry sorbent injection and for use in conjunction with a spray dryer and/or bagfilter. Retrofit application to existing systems is also addressed.

Rochelle, Gary T. (Austin, TX); Chang, John C. S. (Cary, NC)

1991-01-01

423

Phase transformations and the spectral reflectance of solid sulfur - Can metastable sulfur allotropes exist on Io?  

NASA Technical Reports Server (NTRS)

Laboratory investigations have been conducted on the effects of variations in sulfur sample histories on their solid-state transformation rate and the corresponding spectral variation of freshly frozen sulfur. The temporal variations in question may be due to differences in the amount and type of metastable allotropes present in the sulfur after solidification, as well as to the physics of the phase-transformation process itself. The results obtained are pertinent to the physical behavior and spectral variation of such freshly solidified sulfur as may exist on the Jupiter moon Io; this would initially solidify into a glassy solid or monoclinic crystalline lattice, then approach ambient dayside temperatures. Laboratory results imply that the monoclinic or polymeric allotropes can in these circumstances be maintained, and will take years to convert to the stable orthorhombic crystalline form.

Moses, Julianne I.; Nash, Douglas B.

1991-01-01

424

Perfluorinated ionomer-enveloped sulfur cathodes for lithium-sulfur batteries.  

PubMed

Nafion is known to suppress the polysulfide (PS) shuttle effect, a major obstacle to achieving high capacity and long cycle life for lithium-sulfur batteries. However, elaborate control of the layer's configuration is required for high performance. In this regard, we designed a Nafion-enveloped sulfur cathode, where the Nafion layer is formed on the skin of the cathode, covering its surface and edge while not restricting the porosity. Discharge capacity and efficiency were enhanced with the enveloping configuration, demonstrating suppression of shuttle. The edge protection exhibited better cycling stability than an edge-open configuration. In the absence of the Nafion envelope, charged sulfur concentrated on the top region of the cathode because of the relatively lower PS concentration at the cathode surface. Surprisingly, for the Nafion-enveloped cathode, sulfur was evenly distributed along the cathode, indicating that the configuration imparts a uniform PS concentration within the cathode. PMID:25358294

Song, Jongchan; Choo, Min-Ju; Noh, Hyungjun; Park, Jung-Ki; Kim, Hee-Tak

2014-12-01

425

Phase transformations and the spectral reflectance of solid sulfur - Can metastable sulfur allotropes exist on Io?  

NASA Astrophysics Data System (ADS)

Laboratory investigations have been conducted on the effects of variations in sulfur sample histories on their solid-state transformation rate and the corresponding spectral variation of freshly frozen sulfur. The temporal variations in question may be due to differences in the amount and type of metastable allotropes present in the sulfur after solidification, as well as to the physics of the phase-transformation process itself. The results obtained are pertinent to the physical behavior and spectral variation of such freshly solidified sulfur as may exist on the Jupiter moon Io; this would initially solidify into a glassy solid or monoclinic crystalline lattice, then approach ambient dayside temperatures. Laboratory results imply that the monoclinic or polymeric allotropes can in these circumstances be maintained, and will take years to convert to the stable orthorhombic crystalline form.

Moses, J. I.; Nash, D. B.

1991-02-01

426

Annotated bibliography of methods for determining sulfur and forms of sulfur in coal and coal-related materials  

SciTech Connect

Over 400 published papers, presentations at scientific meetings, and reports relating to the determination of sulfur and sulfur forms in coal-related materials have been accumulated, classified, and an evaluation made of their content.

Chriswell, C.D.; Norton, G.A.; Akhtar, S.S.; Straszheim, W.E.; Markuszewski, R.

1993-01-01

427

Assessing Potential Acidification of Marine Archaeological Wood Based on Concentration of Sulfur Species  

SciTech Connect

The presence of sulfur in marine archaeological wood presents a challenge to conservation. Upon exposure to oxygen, sulfur compounds in waterlogged wooden artifacts are being oxidized, producing sulfuric acid. This speeds the degradation of the wood, potentially damaging specimens beyond repair. Sulfur K-edge x-ray absorption spectroscopy was used to identify the species of sulfur present in samples from the timbers of the Mary Rose, a preserved 16th century warship known to undergo degradation through acidification. The results presented here show that sulfur content varied significantly on a local scale. Only certain species of sulfur have the potential to produce sulfuric acid by contact with oxygen and seawater in situ, such as iron sulfides and elemental sulfur. Organic sulfurs, such as the amino acids cysteine and methionine, may produce acid but are integral parts of the wood's structure and may not be released from the organic matrix. The sulfur species contained in the sample reflect the exposure to oxygen while submerged, and this exposure can differ greatly over time and position. A better understanding of the species pathway to acidifications required, along with its location, in order to suggest a more customized and effective preservation strategy. Waterlogged archaeological wood, frequently in the form of shipwrecks, is being excavated for historical purposes in many countries around the world. Even after extensive efforts towards preservation, scientists are discovering that accumulation of sulfate salts results in acidic conditions on the surfaces of the artifacts. Sulfuric acid degrades structural fibers in the wood by acid hydrolysis of cellulose, accelerating the decomposition of the ship timbers. Determining the sulfur content of waterlogged wood is now of great importance in maritime archaeology. Artifact preservation is often more time consuming and expensive than the original excavation; but it is key to the availability of objects for future study as well as maintaining the integrity of historical data and preserving the value of museum pieces. Sulfur occurs in a wide number of oxidation states from -2 to +6, and appears in numerous organic and inorganic compounds in nature. However, it is a very minor component of wood. Sulfur K-edge x-ray absorption spectroscopy (XAS) is a valuable technique because it has the ability to detect very low concentrations of sulfur in the specimen. XAS is also sensitive to differences in oxidation states, as well as long and short range order in molecules.

Not Available

2011-06-22

428

Sulfur uptake and nutrient composition of prune trees as affected by sulfur application  

Microsoft Academic Search

One year?old trees of Marianna 2624 (Prunus cerasifera X P. munsoniana), grafted with French prunes (P. domestica) were grown in the greenhouse in pots containing vermiculite and supplied with graded amounts of sulfate?sulfur (SO4?S) to study the sulfur (S) distribution in the trees and elemental composition as affected by S additions. Leaf, stem, bark, wood, and root samples were analyzed

Izhar Ul Haq; Robert M. Carlson

1993-01-01

429

Hydrogen and sulfuric acid production by electrolysis with anodic depolarization by sulfurous anhydride  

Microsoft Academic Search

Practical aspects of improving the efficiency of water electrolysis with anodic depolarization by sulfurous anhydride in an\\u000a electrolyzer with a solid polymeric electrolyte are discussed. Methods of reducing energy outlays for the production of hydrogen,\\u000a for example, by altering the organization of the feed of sulfurous anhydride to the reaction zone, are proposed and implemented.\\u000a This made it possible to

V. I. Kostin; V. N. Fateev; D. A. Bokach; S. V. Korobtsev; A. V. Kozolii; S. E. Sal’nikov

2008-01-01

430

Safety considerations for the use of sulfur in sulfur-modified pavement materials  

E-print Network

of HZS Toxicity of Sulfur Dioxide Hydrogen Sulfide Emissions from Plasticization of Sulfur Mith Several Additives 30 36 37 39 47 LIST OF FIGURES Figure Effect of Temperature on the Hydrogen Sulfide Concentration Page Comparison of H2S... working distance for laboratory personnel. All mixes were prepared at temperatures below 300'F. The effect of temperature on the hydrogen sulfide concentration generated from the mix is shown in Figure 1 (6). The true peak con- centrations which occur...

Jacobs, Carolyn Yuriko

1980-01-01

431

SOLUBILIZATION OF SULFUR IN AMMONIA AND EQUILIBRIUM COMPOSITION OF SULFUR AMMONIA SOLUTIONS  

Microsoft Academic Search

Sulfur ammonia solutions (SAS) were separated by anion exchange HPLC into the anions S4N and S3N, S3 (and its dimer S6 ), and SxNH 2 (sulfur in oxidized, in reduced and in neutral form resp.). The analysis of the absorption spectra of SAS yields the concentrations of the individual components and leads to the assignement x=4 in SxNH 2. The

S. Seelert; U. Schindewolf

1991-01-01

432

Whole-genome sequencing reveals novel insights into sulfur oxidation in the extremophile Acidithiobacillus thiooxidans  

PubMed Central

Background Acidithiobacillus thiooxidans (A. thiooxidans), a chemolithoautotrophic extremophile, is widely used in the industrial recovery of copper (bioleaching or biomining). The organism grows and survives by autotrophically utilizing energy derived from the oxidation of elemental sulfur and reduced inorganic sulfur compounds (RISCs). However, the lack of genetic manipulation systems has restricted our exploration of its physiology. With the development of high-throughput sequencing technology, the whole genome sequence analysis of A. thiooxidans has allowed preliminary models to be built for genes/enzymes involved in key energy pathways like sulfur oxidation. Results The genome of A. thiooxidans A01 was sequenced and annotated. It contains key sulfur oxidation enzymes involved in the oxidation of elemental sulfur and RISCs, such as sulfur dioxygenase (SDO), sulfide quinone reductase (SQR), thiosulfate:quinone oxidoreductase (TQO), tetrathionate hydrolase (TetH), sulfur oxidizing protein (Sox) system and their associated electron transport components. Also, the sulfur oxygenase reductase (SOR) gene was detected in the draft genome sequence of A. thiooxidans A01, and multiple sequence alignment was performed to explore the function of groups of related protein sequences. In addition, another putative pathway was found in the cytoplasm of A. thiooxidans, which catalyzes sulfite to sulfate as the final product by phosphoadenosine phosphosulfate (PAPS) reductase and adenylylsulfate (APS) kinase. This differs from its closest relative Acidithiobacillus caldus, which is performed by sulfate adenylyltransferase (SAT). Furthermore, real-time quantitative PCR analysis showed that most of sulfur oxidation genes were more strongly expressed in the S0 medium than that in the Na2S2O3 medium at the mid-log phase. Conclusion Sulfur oxidation model of A. thiooxidans A01 has been constructed based on previous studies from other sulfur oxidizing strains and its genome sequence analyses, providing insights into our understanding of its physiology and further analysis of potential functions of key sulfur oxidation genes. PMID:24993543

2014-01-01

433

Consistency Between Measurements and Theory for Sulfur Gases and Oxidants During the Pacific Atmospheric Sulfur Experiment  

NASA Astrophysics Data System (ADS)

Airborne gas phase measurements of sulfur dioxide, dimethylsulfide, dimethylsulfoxide, methane sulfonic acid, sulfuric acid, hydroxyl, perhydroxyl, hydrogen peroxide, methylhydroperoxide, ozone, and carbon monoxide together with aerosol microphysical properties and bulk and size-dependent aerosol composition are examined for consistency with photochemical theory. The observations come from 14 research flights using the NCAR C-130 flown mostly southeast of Kiritimati in relatively cloud-free marine boundary layer air. This region was chosen because of its extremely low nitrogen oxide mixing ratios and minimal horizontal gradients in composition. A size-dependent gas-particle mass-transfer model is used to calculate the exchange rates of dimethylsulfoxide, methanesulfonic acid and sulfuric acid between the gas and aerosol. Gas kinetic reactions, aqueous reactions, and heterogeneous processes are used in the evaluation. Mass accommodation coefficients, Henry's Law solubilities, and the effective yields of methanesulfonic acid, sulfur dioxide, sulfuric acid and dimethylsulfoxide from dimethylsulfide are estimated and consistent with the literature. Gas phase hydroxyl chemistry alone is sufficient to explain observed methanesulfonic acid and sulfuric acid vapor concentrations.

Heikes, B. G.; Higbie, A.; O'Sullivan, D. W.; Bandy, A. R.; Mauldin, L.; Cantrell, C.; Anderson, R. S.; Campos, T.; Huebert, B.; Bloomquist, B.; Wang, Y.; Heizer, C. G.; Pollack, I. B.; Weinheimer, A. J.

2008-12-01

434

Sulfur-impregnated core-shell hierarchical porous carbon for lithium-sulfur batteries.  

PubMed

Core-shell hierarchical porous carbon spheres (HPCs) were synthesized by a facile hydrothermal method and used as host to incorporate sulfur. The microstructure, morphology, and specific surface areas of the resultant samples have been systematically characterized. The results indicate that most of sulfur is well dispersed over the core area of HPCs after the impregnation of sulfur. Meanwhile, the shell of HPCs with void pores is serving as a retard against the dissolution of lithium polysulfides. This structure can enhance the transport of electron and lithium ions as well as alleviate the stress caused by volume change during the charge-discharge process. The as-prepared HPC-sulfur (HPC-S) composite with 65.3?wt?% sulfur delivers a high specific capacity of 1397.9?mA?h?g(-1) at a current density of 335?mA?g(-1) (0.2 C) as a cathode material for lithium-sulfur (Li-S) batteries, and the discharge capacity of the electrode could still reach 753.2?mA?h?g(-1) at 6700?mA?g(-1) (4?C). Moreover, the composite electrode exhibited an excellent cycling capacity of 830.5?mA?h?g(-1) after 200?cycles. PMID:25346404

Zhang, Fei-Fei; Huang, Gang; Wang, Xu-Xu; Qin, Yu-Ling; Du, Xin-Chuan; Yin, Dong-Ming; Liang, Fei; Wang, Li-Min

2014-12-22

435

Effect of a variety of Chinese herbs and an herb-containing dentifrice on volatile sulfur compounds associated with halitosis: An in vitro analysis  

PubMed Central

Background: The principal components of halitosis are volatile sulfur compounds (VSCs) such as hydrogen sulfide, methyl mercaptan, and dimethylsulfide or compounds such as butyric acid, propionic acid, putrescine, and cadaverine. Objective: The aim of this study was to evaluate the effect of Chinese herbs on VSCs in vitro. Methods: Saliva samples from volunteers were used as the source for the evaluation of bacterial activity and VSC inhibition. Extracted substances from Chinese herbs were identified by VSC inhibition tests with a Halimeter and microbial sensitivity testing. The effectiveness on halitosis was compared between a dentifrice containing one of the effective Chinese herbs (ie, chrysanthemum flower [Chrysanthemum morifolium flos]), 4 commercially available antihalitosis dentifrices, and a positive control that received no treatment. Results: Ten volunteers provided saliva samples for VSC testing. Of the 40 herbs tested, 14 extracts had percent inhibition rates of VSCs >50%. Ten herbs showed greatest effect against all culturable microorganisms with bacterial inhibition >70%. There was a weak positive correlation between bacteriostasis and the anti-VSC activity of the herbs with a correlation coefficient of 0.2579 (Pearson). The mean (SD) values of the VSC testing were as follows: dentifrice containing chrysanthemum flower, 55.91 (8.16) ppb; Crest Tea Refreshing Dentifrice®, 48.39 (7.48) ppb (P = NS); Cortex Phellodendri Dentifrice®, 139.90 (14.70) ppb (P < 0.01); Colgate Total Plus Whitening®, 120.94 (15.58) ppb (P < 0.01); Zhong Hua Chinese Herbs Dentifrice®, 136.96 (13.06) ppb (P < 0.01); and positive control, 312.38 (28.58) ppb (P < 0.01). Conclusions: Of 40 herbs tested, 14 Chinese herbs were found to be effective for VSC inhibition. A dentifrice containing chrysanthemum flower reduced the formation of VSC in vitro, showing a significantly greater effect than the control group and 3 of 4 dentifrices already on the market. PMID:24683259

Li, Ming-yu; Wang, Jun; Xu, Zhu-ting

2010-01-01

436

A comparative study of two composts as filter media for the removal of gaseous reduced sulfur compounds (RSCs) by biofiltration: application at industrial scale.  

PubMed

This work presents the use of two composts as filter media for the treatment by biofiltration of odors emitted during the aerobic composting of a mixture containing sewage sludge and yard waste. The chemical analysis of the waste gas showed that the malodorous compounds at trace level were the reduced sulfur compounds (RSCs) which were dimethyl sulfide (Me(2)S), methanethiol (MeSH) and hydrogen sulfide (H(2)S). Laboratory tests for biofiltration treatment of RSCs were performed in order to compare the properties of two filter media, consisted of a mature compost with yard waste (YW) and a mixture of mature compost with sewage sludge and yard waste (SS/YW). The maximum elimination capacity (EC) values obtained with the YW mature compost as packing material were 12.5 mg m(-3)h(-1) for H(2)S, 7.9 mg m(-3)h(-1) for MeSH and 34 mg m(-3)h(-1) for Me(2)S, and the removal efficiency decreased in the order of: H(2)S>MeSH>Me(2)S. Moreover, the YW compost filter medium had a better behavior than the filter medium based on SS/YW in terms of acclimation of the microbial communities and moisture content. According to these results, a YW mature compost as packing material for an industrial biofilter were designed and this industrial biofilter was found effective under specified conditions (without inoculation and addition of water). The results showed that the maximum EC value of RSCs was 935 mg m(-3)h(-1) (100% removal efficiency, RE) for an inlet loads (IL) between 0 and 1000 mg m(-3)h(-1). Thus, YW compost medium was proven efficient for biofiltration of RSCs both at laboratory and industrial scale. PMID:23036720

Hort, C; Gracy, S; Platel, V; Moynault, L

2013-01-01

437

The removal of sulfur dioxide from flue gases  

PubMed Central

The growth of industrialization makes it imperative to reduce the amounts of sulfur dioxide emitted into the atmosphere. This article describes various processes for cleaning flue gases, and gives details of new methods being investigated. Wet scrubbing with water, though widely practised, has many disadvantages. Scrubbing with zinc oxide, feasible in zinc works, is more satisfactory. Dry methods use a solid absorbent; they have the advantage of a high emission temperature. Other methods are based on the addition to the fuel or the flue gases of substances such as activated metal oxides, which react with the sulfur to form compounds less harmful than sulfur dioxide. Also being investigated are a two-stage combustion system, in which the sulfur dioxide is removed in the first stage, and the injection of activated powdered dolomite into burning fuel; the resulting sulfates being removed by electrostatic precipitation. A wet catalysis process has recently been developed. Most of the cleaning processes are not yet technically mature, but first results show good efficiency and relatively low cost. PMID:14315714

Kettner, Helmut

1965-01-01

438

Humic sulfur in eutrophic bay sediments: Characterization by sulfur stable isotopes and K-edge XANES spectroscopy  

NASA Astrophysics Data System (ADS)

Organic sulfur (OS) is an important sedimentary sulfur pool in marine sediments and chemical extractions are often used for quantification of various OS pools, however, OS sources and mechanisms of OS formation are not well understood. In this study, sulfur stable isotope and sulfur X-ray absorption near edge structure (XANES) spectroscopy were combined to investigate the sources and speciation of humic-acid sulfur (HA-S) and fulvic-acid sulfur (FA-S) in sediments of eutrophic Jiaozhou Bay. Whilst there may be some indication that eutrophication has enhanced FA-S burial in the sediment, this has not substantially modified the characteristically low humic sulfur (i.e., HA-S + FA-S) contents of the sediments. Sulfur isotopic compositions indicate that both HA-S and FA-S are mixtures of diagenetic and biosynthetic OS in origin; HA-S is dominated by biosynthetic sulfur and FA-S by diagenetic source. Sulfur isotopic compositions and contents of pyrite and diagenetic OS indicate that inhibition of sulfurization by pyrite formation, if any, appears insignificant. XANES analysis suggests that the contents of high oxidized OS (i.e., sulfones and ester-sulfates) and strongly reduced OS species are comparable in the HA-S, whereas the FA-S is dominated by strongly reduced OS as a result of enhanced sulfurization.

Zhu, Mao-Xu; Chen, Liang-Jin; Yang, Gui-Peng; Huang, Xiang-Li; Ma, Chen-Yan

2014-02-01

439

PROJECTION OF 1985 MARKET POTENTIAL FOR FGD (FLUE GAS DESULFURIZATION) BYPRODUCT SULFUR AND SULFURIC ACID IN THE U.S  

EPA Science Inventory

The report projects the 1985 market potential for flue gas desulfurization (FGD) byproduct sulfur and sulfuric acid in the U.S. The projection is 165,000 tons of sulfur from 11 power plants and 554,000 tons of acid from 6 power plants, with a combined benefit to the affected indu...

440

The effect of sulfur loading on the electrochemical performance of a sulfur-polymer composite cathode coated on aluminium foil.  

PubMed

A scaling-up investigation of a sulfur-polymer cathode for rechargeable lithium-sulfur batteries is reported. The proposed procedure uses a low cost aluminium current collector and is suitable for mass production of a composite cathode, with sulfur loading levels of up to 5.9 mg cm(-2), and good electrochemical performance. PMID:24910180

Doan, The Nam Long; Gosselink, Denise; Hoang, Tuan K A; Chen, P

2014-07-21

441

Biogeochemical Cycles of Carbon and Sulfur  

NASA Technical Reports Server (NTRS)

The elements carbon (C) and sulfur (S) interact with each other across a network of elemental reservoirs that are interconnected by an array of physical, chemical and biological processes. These networks are termed the biogeochemical C and S cycles. The compounds of C are highly important, not only as organic matter, but also as atmospheric greenhouse gases, pH buffers in seawater, oxidation-reduction buffers virtually everywhere, and key magmatic constituents affecting plutonism and volcanism. The element S assumes important roles as an oxidation-reduction partner with C and Fe in biological systems, as a key constituent in magmas and volcanic gases, and as a major influence upon pH in certain environments. This presentation describes the modern biogeochemical C and S cycles. Measurements are described whereby stable isotopes can help to infer the nature and quantitative significance of biological and geological processes involved in the C and S cycles. This lecture also summarizes the geological and climatologic aspects of the ancient C and S cycles, as well as the planetary and extraterrestrial processes that influenced their evolution over millions to billions of years.

DesMarais, David J.; DeVincenzi, D. (Technical Monitor)

2002-01-01

442

CATALYST EVALUATION FOR A SULFUR DIOXIDE-DEPOLARIZED ELECTROLYZER  

SciTech Connect

Thermochemical processes are being developed to provide global-scale quantities of hydrogen. A variant on sulfur-based thermochemical cycles is the Hybrid Sulfur (HyS) Process which uses a sulfur dioxide depolarized electrolyzer (SDE) to produce the hydrogen. Testing examined the activity and stability of platinum and palladium as the electrocatalyst for the SDE in sulfuric acid solutions. Cyclic and linear sweep voltammetry revealed that platinum provided better catalytic activity with much lower potentials and higher currents than palladium. Testing also showed that the catalyst activity is strongly influenced by the concentration of the sulfuric acid electrolyte.

Hobbs, D; Hector Colon-Mercado, H

2007-01-31

443

Method to prevent sulfur accumulation in membrane electrode assembly  

DOEpatents

A method of operating a hybrid sulfur electrolyzer to generate hydrogen is provided that includes the steps of providing an anolyte with a concentration of sulfur dioxide, and applying a current. During steady state generation of hydrogen a plot of applied current density versus concentration of sulfur dioxide is below a boundary line. The boundary line may be linear and extend through the origin of the graph with a slope of 0.001 in which the current density is measured in mA/cm2 and the concentration of sulfur dioxide is measured in moles of sulfur dioxide per liter of anolyte.

Steimke, John L; Steeper, Timothy J; Herman, David T

2014-04-29

444

The Bleaching and Photostabilization of High-Yield Pulp by Sulfur Compounds. II. Reaction of Glycol Mercaptoesters with Model Quinones  

Microsoft Academic Search

The reaction of ethylene glycol dimercaptoacetate and pentaerythritol tetramercaptoacetate with p-benzoquinone have been investigated, both in solution and in the presence of cellulose fibers. In either system, Michael addition is the predominant reaction, leading to decolorization of the quinone by converting it to a substituted hydroquinone. This reaction accounts for the initial bleaching of high-yield pulp produced by these compounds.

Barbara J. W. Cole; Jingyang Wang; Raymond C. Fort Jr

2000-01-01

445

An Efficient, Solvent-free Method for the One-pot Condensation of ?-naphthol, Aromatic Aldehydes and Cyclic 1,3-dicarbonyl Compounds Catalyzed by Silica Sulfuric Acid  

Microsoft Academic Search

Silica sulfuric acid as a reusable and efficient catalyst has been used for the preparation of 12-aryl-8,9,10,12-tetrhydro benzo[a]xanthene-11-one derivatives from the one-pot multi component reaction of aromatic aldehydes, ?-naphthol and a cyclic diketone under solvent free conditions. High yields, simple procedure, easy work up, short reaction times and mild conditions are the advantages of this methodology.

Firouzeh Nemati; Maryam Arghan; Ali Amoozadeh

2011-01-01

446

Efficient, Solvent-Free Method for the One-Pot Condensation of ?-Naphthol, Aromatic Aldehydes, and Cyclic 1,3-Dicarbonyl Compounds Catalyzed by Silica Sulfuric Acid  

Microsoft Academic Search

Silica sulfuric acid as a reusable and efficient catalyst has been used for the preparation of 12-aryl-8,9,10,12-tetrhydro benzo[a]xanthene-11-one derivatives from the one-pot multicomponent reaction of aromatic aldehydes, ?-naphthol, and a cyclic diketone under solvent-free conditions. Good yields, simple procedure, easy workup, short reaction times, and mild conditions are the advantages of this methodology.

Firouzeh Nemati; Maryam Arghan; Ali Amoozadeh

2012-01-01

447

Xanthan sulfuric acid: A new and efficient bio-supported solid acid catalyst for the synthesis of ?-amino nitriles by condensation of carbonyl compounds, amines, and trimethylsilylcyanide  

Microsoft Academic Search

In this work, ?-amino nitriles are synthesized by a three-component one-pot condensation reaction of aldehydes or ketones, amines and trimethylsilylcyanide in the presence of a catalytic amount of xanthan sulfuric acid as a new bio-supported catalyst, in excellent yields with short reaction times at ambient temperature. The xanthan as the base of the catalyst was produced biologically from a native

Ahmad Shaabani; Ali Maleki; Mohammad Reza Soudi; Hamid Mofakham

2009-01-01

448

Development of instrumental methods of analysis of sulfur compounds in coal process streams. Ninth quarterly technical progress report, October-December 1979  

SciTech Connect

Capabilities for constructing multidimensional Pourbaix Diagrams have been expanded. New algorithms have been developed for the generation of abundance profiles and for delineating thermodynamic stability domains of poly-sulfur moieties, which contain several atoms of sulfur per molecule. Mechanisms of electrooxidation of thiosulfate and of dibenzothiophene have been investigated. Under judiciously controlled experimental conditions, these electrode reactions proceed with 100% current efficiency at glassy carbon anodes. They provide a sound theoretical basis for dependable electroanalytical methods applicable to the determination of S/sub 2/O/sub 3//sup -/ and of dibenzothiophene in coal conversion process streams and products. The systematic search for specific reagents, amenable to the determination of sulfur contaminants by thermometric enthalpy titration and by direct injection enthalpimetry, was continued. 0.12% sulfide has been successfully determined by differential pulse polarography at a dropping mercury anode in scrubber water from a coal liquefaction process. Concentration levels of 1 ppM (or less) of sulfide were estimated in two gasifier condensate samples by the same method. Differential pulse voltammetry at a rotated glassy carbon disk anode was used to detect and determine quantitatively the presence of 0.1% dibenzothiophene in an SRC II stripper bottom product.

Jordan, J.

1980-01-01

449

A lithium-sulfur cathode with high sulfur loading and high capacity per area: a binder-free carbon fiber cloth-sulfur material.  

PubMed

A sulfur cathode with high capacity per area (>7 mA h cm(-2)) and high sulfur loading (6.7 mg cm(-2)) was fabricated by synthesizing a carbon fiber cloth-sulfur composite via a simple method. It is worth noting that an ingenious method is adopted which can improve the performance of Li-S batteries by forming in situ polysulfide ions. PMID:24978617

Miao, Lixiao; Wang, Weikun; Yuan, Keguo; Yang, Yusheng; Wang, Anbang

2014-11-11

450

The solubility of sulfur hexafluoride in water and seawater  

Microsoft Academic Search

The concentration of sulfur hexafluoride (SF6) in the atmosphere has been rapidly increasing during the past several decades. This long-lived compound enters the surface ocean by air–sea gas exchange and is potentially a very useful transient tracer for studying ocean circulation and mixing. SF6 has also been directly injected into the ocean at a minimal number of locations as a

John L Bullister; David P Wisegarver; Frederick A Menzia

2002-01-01

451

High-sulfur in beef cattle diets: a review.  

PubMed

While many cattle feeding areas in the United States have long dealt with high sulfate water, increased feeding of ethanol coproducts such as distillers grains with solubles to beef cattle has led to a corresponding increase in dietary sulfur. As a result, sulfur metabolism in the ruminant has been the focus of many research studies over the past 10 yr, and advances in our knowledge have been made. Excessive sulfur in cattle diets may have implications on trace mineral absorption, dry matter intake, and overall cattle growth. This review will focus on what we have learned about the metabolism of sulfur in the ruminant, including ruminal sulfate reducing bacteria, the role of ruminally available sulfur, factors affecting the production of hydrogen sulfide in the rumen, and the potential mechanisms behind sulfur toxicity in cattle. Additionally, this review will discuss potential strategies to minimize risk of sulfur toxicity when cattle are fed high-sulfur diets, including dietary and management strategies. Further research related to high-sulfur diets including implications for carcass characteristics, meat quality, and animal health will also be discussed. As ethanol production processes continue to change, the nutrient profile of the resulting coproducts will as well. Often removal of one nutrient such as oil will result in the concentration of other nutrients such as sulfur. Therefore, it seems even more likely that a better understanding of sulfur metabolism in the ruminant will be important to beef cattle feeding in the future. PMID:24981568

Drewnoski, M E; Pogge, D J; Hansen, S L

2014-09-01

452

Nitrogen, oxygen or sulfur containing heterocyclic compounds as analgesic drugs used as modulators of the nitroxidative stress.  

PubMed

Numerous lines of evidence suggest that heterocyclic compounds used as analgesic, anti-inflammatory and anti-migraine agents can be potent regulators of the nitroxidative stress and targeting free nitrogen and oxygen radicals is a very promising strategy for future pain management. Both classical analgesics (nonsteroidal anti-inflammatory drugs, opioid drugs) and many analgesic adjuvants, including desipramine, duloxetine, fluoxetine, paroxetine, escitalopram, phenytoin or carbamazepine and ?-lipoic acid can modulate the balance between pro-oxidant and antioxidant processes in the mammalian tissues and these properties of drugs such as indomethacin, meloxicam, tenoxicam, valdecoxib or some metabolites of analgesic drugs formed by the activity of tissue peroxidases may contribute to their clinical efficacy and drug-related toxic effects, including gastrointestinal ulcers, hepatic failure, agranulocytosis, aplastic anemia, neutropenia, opiate-induced hyperalgesia and tolerance. The antioxidant capacities of novel heterocyclic compounds, including the compounds acting either by prevention of formation or catalyzed decomposition of peroxynitrite anion (ONOO-), namely the peroxynitrite decomposition catalysts or as superoxide (O2 •-)-scavengers which are the functional mimetics of superoxide dismutase (SOD) enzymes (SODm), as well as the derivatives of 6-nitro-3,4-methylenedioxyphenyl-Nacylhydrazone (LASSBio-881) or ?-butyrolactone (LPP1, BM113, BM113A, BM138 and BM138A) are also discussed as potent and promising future heterocyclic analgesics. PMID:22876956

Salat, Kinga; Moniczewski, Andrzej; Librowski, Tadeusz

2013-03-01

453

Large sulfur isotope fractionation does not require disproportionation.  

PubMed

The composition of sulfur isotopes in sedimentary sulfides and sulfates traces the sulfur cycle throughout Earth's history. In particular, depletions of sulfur-34 ((34)S) in sulfide relative to sulfate exceeding 47 per mil (‰) often serve as a proxy for the disproportionation of intermediate sulfur species in addition to sulfate reduction. Here, we demonstrate that a pure, actively growing culture of a marine sulfate-reducing bacterium can deplete (34)S by up to 66‰ during sulfate reduction alone and in the absence of an extracellular oxidative sulfur cycle. Therefore, similar magnitudes of sulfur isotope fractionation in sedimentary rocks do not unambiguously record the presence of other sulfur-based metabolisms or the stepwise oxygenation of Earth's surface environment during the Proterozoic. PMID:21719675

Sim, Min Sub; Bosak, Tanja; Ono, Shuhei

2011-07-01

454

Effects of dynamic electrodes on sodium sulfur cell performance  

SciTech Connect

In this paper the construction and performance of a sodium sulfur cell with dynamic sodium and sulfur electrodes are described. The cell was constructed with a sodium feed into a {beta}{double prime}-alumina tube and a sulfur feed into an annular sulfur electrode. Low-resistance graphite felt was tightly packed around the {beta}{double prime}-alumina tube. Sodium pentasulfide was removed from the sulfur electrode. The cell was stably charged in the two-phase region and a high charge acceptance of 95% was obtained. The cell capacity and the discharge voltage increased with the sulfur and sodium feeds. The internal resistance was decreased by thinning the sulfur electrode and using a single zone of low-resistance graphite felt.

Tokoi, H.; Watahiki, N.; Sumida, I. (Hitachi, Ltd., Energy Research Lab., 1168 Moriyama-cho, Hitachi, Ibaraki 316 (JP))

1991-05-01

455

Accumulation of atmospheric sulfur in some Costa Rican soils  

USGS Publications Warehouse

Sulfur is one of the macronutrient elements whose sources to terrestrial ecosystems should shift from dominance by rock-weathering to atmospheric deposition as soils and underlying substrate undergo progressive weathering and leaching. However, the nature and timing of this transition is not well known. We investigated sources of sulfur to tropical rain forests growing on basalt-derived soils in the Osa Peninsula region of Costa Rica. Sulfur sources were examined using stable isotope ratios (?34S) and compared to chemical indices of soil development. The most weathered soils, and the forests they supported, are dominated by atmospheric sulfur, while a less weathered soil type contains both rock-derived and atmospheric sulfur. Patterns of increasing ?34S with increasing soil sulfur concentration across the landscape suggest atmospheric sulfur is accumulating, and little rock-derived sulfur has been retained. Soil sulfur, minus adsorbed sulfate, is correlated with carbon and nitrogen, implying that sulfur accumulation occurs as plants and microbes incorporate sulfur into organic matter. Only the lower depth increments of the more weathered soils contained significant adsorbed sulfate. The evidence suggests a pattern of soil development in which sulfur-bearing minerals in rock, such as sulfides, weather early relative to other minerals, and the released sulfate is leached away. Sulfur added via atmospheric deposition is retained as organic matter accumulates in the soil profile. Adsorbed sulfate accumulates later, driven by changes in soil chemistry and mineralogy. These aspects of sulfur behavior during pedogenesis in this environment may hasten the transition to dominance by atmospheric sources.

Bern, Carleton R.; Townsend, Alan R.

2013-01-01

456

HYBRID SULFUR RECOVERY PROCESS FOR NATURAL GAS UPGRADING  

SciTech Connect

This first quarter report of 2001 describes progress on a project funded by the U.S. Department of Energy (DOE) to test a hybrid sulfur recovery process for natural gas upgrading. The process concept represents a low cost option for direct treatment of natural gas streams to remove H{sub 2}S in quantities equivalent to 0.2-25 metric tons (LT) of sulfur per day. This process is projected to have lower capital and operating costs than the competing technologies, amine/aqueous iron liquid redox and amine/Claus/tail gas treating, and have a smaller plant footprint, making it well suited to both on-shore and offshore applications. CrystaSulf (service mark of Gas Research Institute) is a new nonaqueous sulfur recovery process that removes hydrogen sulfide (H{sub 2}S) from gas streams and converts it into elemental sulfur. CrystaSulf features high sulfur recovery similar to aqueous-iron liquid redox sulfur recovery processes, but differs from the aqueous processes in that CrystaSulf controls the location where elemental sulfur particles are formed. In the hybrid process, approximately 1/3 of the total H{sub 2}S in the natural gas is first oxidized to SO{sub 2} at low temperatures over a heterogeneous catalyst. Low temperature oxidation is done so that the H{sub 2}S can be oxidized in the presence of methane and other hydrocarbons without oxidation of the hydrocarbons. The project involves the development of a catalyst using laboratory/bench-scale catalyst testing, and then demonstration of the catalyst at CrystaTech's pilot plant in west Texas. During this reporting period tests were done to determine the effect of hydrocarbons such as n-hexane on catalyst performance with and without H{sub 2}S present. The experiments showed that hexane oxidation is suppressed when H{sub 2}S is present. Hexane represents the most reactive of the C1 to C6 series of alkanes. Since hexane exhibits low reactivity under H{sub 2}S oxidation conditions, and more importantly, does not change the SO{sub 2} selectivity, we can conclude that the C1-C6 hydrocarbons should not significantly interfere with the oxidation of H{sub 2}S into SO{sub 2}. Plans to determine the effect of aromatic compounds on catalyst performance for extended periods, and for catalyst pelletization and continued testing are described.

Girish Srinivas; Steven C. Gebhard; David W. DeBerry

2001-08-01

457

Fluorimetric determination of some sulfur containing compounds through complex formation with terbium (Tb+3) and uranium (U+3).  

PubMed

Two simple, sensitive and specific fluorimetric methods have been developed for the determination of some sulphur containing compounds namely, Acetylcysteine (Ac), Carbocisteine (Cc) and Thioctic acid (Th) using terbium Tb+3 and uranium U+3 ions as fluorescent probes. The proposed methods involve the formation of a ternary complex with Tb+3 in presence of Tris-buffer method (I) and a binary complex with aqueous uranyl acetate solution method (II). The fluorescence quenching of Tb+3 at 510, 488 and 540 nm (lambda(ex) 250, 241 and 268 nm) and of uranyl acetate at 512 nm (lambda(ex) 240 nm) due to the complex formation was quantitatively measured for Ac, Cc and Th, respectively. The reaction conditions and the fluorescence spectral properties of the complexes have been investigated. Under the described conditions, the proposed methods were applicable over the concentration range (0.2-2.5 microg ml(-1)), (1-4 microg ml(-1)) and (0.5-3.5 microg