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Sample records for high sulfur trioxide

  1. High resolution spectroscopy of sulfur trioxide and carbon suboxide

    NASA Astrophysics Data System (ADS)

    Masiello, Tony

    High resolution spectroscopy was used to study the properties of two simple polyatomic molecules, sulfur trioxide, SO3, and carbon suboxide, C3O2. The fundamental modes and several hot bands of the 18O isotopic forms of SO3 (32S18O 3 and 34S18O3) have been investigated using both infrared spectroscopy and coherent anti-Stokes Raman scattering spectroscopy (CARS). The Raman-active symmetric stretching mode, nu 1, shows complex Q-branch patterns due to indirect Coriolis couplings, l-resonances, and Fermi resonances with infrared inaccessible nu2, nu4 combination/overtone levels. 18O isotopic substitution changes the character of these interactions in such a way that their effect on the nu1 CARS spectrum is unique among the different isotopomers studied. Accurate rovibrational constants are determined for all of the mixed states for the first time, leading to deperturbed values for the nu1 band origin of 1004.661(24) and 1004.693(23) for 34S18O 3 and 32S18O3 respectively. The strong Coriolis coupling is very noticeable in these species due to the close proximity of the nu2 and nu4 fundamental vibrations. The effect that this and other interaction terms have on the nu1 CARS spectrum of 34S18O3 is examined by selectively turning off the coupling between the hot bands. A global force field analysis was performed with the fundamental frequency values of all of the isotopomers studied that revealed a counterintuitive trend in the bond lengths between sulfur oxide species. In addition, band center frequencies for all the mixed 16O-18O isotopic species are computed. High-resolution CARS Spectroscopy was also used to study the nu 1 symmetric CO stretching mode of the quasi-linear molecule carbon suboxide, C3O2. Q-branches are seen that originate from the ground state and from thermally-populated levels of the unusually low frequency nu7 bending mode. The intensity variation of these on cooling to about 110 K in a jet expansion requires reversal of the order of assignment

  2. Determination of sulfur trioxide in engine exhaust.

    PubMed

    Arnold, D R

    1975-04-01

    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.

  3. Determination of sulfur trioxide in engine exhaust.

    PubMed Central

    Arnold, D R

    1975-01-01

    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

  4. An Aerosol Condensation Model for Sulfur Trioxide

    SciTech Connect

    Grant, K E

    2008-02-07

    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

  5. EMISSIONS OF SULFUR TRIOXIDE FROM COAL-FIRED POWER PLANTS

    EPA Science Inventory

    Emissions of sulfur trioxide (SO3) are a key component of plume opacity and acid deposition. Consequently, these emissions need to be low enough not to cause opacity violations and acid deposition. Generally, a small fraction of sulfur in coal is converted to SO3 in coal-fired co...

  6. Emissions of sulfur trioxide from coal-fired power plants.

    PubMed

    Srivastava, R K; Miller, C A; Erickson, C; Jambhekar, R

    2004-06-01

    Emissions of sulfur trioxide (SO3) are a key component of plume opacity and acid deposition. Consequently, these emissions need to be low enough to not cause opacity violations and acid deposition. Generally, a small fraction of sulfur (S) in coal is converted to SO3 in coal-fired combustion devices such as electric utility boilers. The emissions of SO3 from such a boiler depend on coal S content, combustion conditions, flue gas characteristics, and air pollution devices being used. It is well known that the catalyst used in the selective catalytic reduction (SCR) technology for nitrogen oxides control oxidizes a small fraction of sulfur dioxide in the flue gas to SO3. The extent of this oxidation depends on the catalyst formulation and SCR operating conditions. Gas-phase SO3 and sulfuric acid, on being quenched in plant equipment (e.g., air preheater and wet scrubber), result in fine acidic mist, which can cause increased plume opacity and undesirable emissions. Recently, such effects have been observed at plants firing high-S coal and equipped with SCR systems and wet scrubbers. This paper investigates the factors that affect acidic mist production in coal-fired electric utility boilers and discusses approaches for mitigating emission of this mist. PMID:15242154

  7. Environmental management of sulfur trioxide emission: impact of SO3 on human health.

    PubMed

    Kikuchi, R

    2001-06-01

    The major contributors to global acidification are sulfur oxides and nitrogen oxides emitted mostly by the burning of fossil fuels. From the scientific point of view, it is necessary to make a clear distinction between sulfur dioxide and sulfur trioxide when referring to sulfur oxides. These two air pollutants have different properties. This paper reports the following aspects: the strong effect of sulfur trioxide on local human health (a case study of asthma in Yokkaichi), the problem of corrosion caused by sulfur trioxide, the difference in analytical methods for determining sulfur dioxide concentrations and sulfur trioxide concentrations, and the difference in removal methods for sulfur dioxide and sulfur trioxide. An important initiative at the third European conference of environment ministers was that the issue of human health related to local air pollution should be given priority over that of global pollution. The declines in the emissions of sulfur dioxide and nitrogen oxides have mainly been effective in reducing acidification due to long-range transport. The reduction in sulfur trioxide may be more effective in improving local human health mentioned in the initiative.

  8. Photoresist removal using gaseous sulfur trioxide cleaning technology

    NASA Astrophysics Data System (ADS)

    Del Puppo, Helene; Bocian, Paul B.; Waleh, Ahmad

    1999-06-01

    A novel cleaning method for removing photoresists and organic polymers from semiconductor wafers is described. This non-plasma method uses anhydrous sulfur trioxide gas in a two-step process, during which, the substrate is first exposed to SO3 vapor at relatively low temperatures and then is rinsed with de-ionized water. The process is radically different from conventional plasma-ashing methods in that the photoresist is not etched or removed during the exposure to SO3. Rather, the removal of the modified photoresist takes place during the subsequent DI-water rinse step. The SO3 process completely removes photoresist and polymer residues in many post-etch applications. Additional advantages of the process are absence of halogen gases and elimination of the need for other solvents and wet chemicals. The process also enjoys a very low cost of ownership and has minimal environmental impact. The SEM and SIMS surface analysis results are presented to show the effectiveness of gaseous SO3 process after polysilicon, metal an oxide etch applications. The effects of both chlorine- and fluorine-based plasma chemistries on resist removal are described.

  9. Mechanism for forming hydrogen chloride and sodium sulfate from sulfur trioxide, water, and sodium chloride

    NASA Technical Reports Server (NTRS)

    Anderson, A. B.

    1984-01-01

    A molecular orbital study of sodium sulfate and hydrogen chloride formation from sulfur trioxide, water, and sodium chloride shows no activation barrier, in agreement with recent experimental work of Kohl, Fielder, and Stearns. Two overall steps are found for the process. First, gas-phase water reacts with sulfur trioxide along a pathway involving a linear O-H-O transition state yielding closely associated hydroxyl and bisulfite which rearrange to become a hydrogen sulfate molecule. Then the hydrogen sulfate molecule transfers a hydrogen atom to a surface chloride in solid sodium chloride while an electron and a sodium cation simultaneously transfer to yield sodium bisulfate and gas-phase hydrogen chloride. This process repeats. Both of these steps represent well-known reactions for which mechanisms have not been previously determined.

  10. Studies of the fate of sulfur trioxide in coal-fired utility boilers based on modified selected condensation methods.

    PubMed

    Cao, Yan; Zhou, Hongcang; Jiang, Wu; Chen, Chien-Wei; Pan, Wei-Ping

    2010-05-01

    The formation of sulfur trioxide (SO(3)) in coal-fired utility boilers can have negative effects on boiler performance and operation, such as fouling and corrosion of equipment, efficiency loss in the air preheater (APH), increase in stack opacity, and the formation of PM(2.5). Sulfur trioxide can also compete with mercury when bonding with injected activated carbons. Tests in a lab-scale reactor confirmed there are major interferences between fly ash and SO(3) during SO(3) sampling. A modified SO(3) procedure to maximize the elimination of measurement biases, based on the inertial-filter-sampling and the selective-condensation-collecting of SO(3), was applied in SO(3) tests in three full-scale utility boilers. For the two units burning bituminous coal, SO(3) levels starting at 20 to 25 ppmv at the inlet to the selective catalytic reduction (SCR), increased slightly across the SCR, owing to catalytic conversion of SO(2) to SO(3,) and then declined in other air pollutant control device (APCD) modules downstream to approximately 5 ppmv and 15 ppmv at the two sites, respectively. In the unit burning sub-bituminous coal, the much lower initial concentration of SO(3) estimated to be approximately 1.5 ppmv at the inlet to the SCR was reduced to about 0.8 ppmv across the SCR and to about 0.3 ppmv at the exit of the wet flue gas desulfurization (WFGD). The SO(3) removal efficiency across the WFGD scrubbers at the three sites was generally 35% or less. Reductions in SO(3) across either the APH or the dry electrostatic precipitator (ESP) in units burning high-sulfur bituminous coal were attributed to operating temperatures being below the dew point of SO(3).

  11. PREPARATION OF URANIUM TRIOXIDE

    DOEpatents

    Buckingham, J.S.

    1959-09-01

    The production of uranium trioxide from aqueous solutions of uranyl nitrate is discussed. The uranium trioxide is produced by adding sulfur or a sulfur-containing compound, such as thiourea, sulfamic acid, sulfuric acid, and ammonium sulfate, to the uranyl solution in an amount of about 0.5% by weight of the uranyl nitrate hexahydrate, evaporating the solution to dryness, and calcining the dry residue. The trioxide obtained by this method furnished a dioxide with a considerably higher reactivity with hydrogen fluoride than a trioxide prepared without the sulfur additive.

  12. DFT study of hydrogen fluoride and sulfur trioxide interactions on the surface of Pt-decorated graphene

    NASA Astrophysics Data System (ADS)

    Rad, Ali Shokuhi

    2016-08-01

    In this study, we investigate the adsorption properties of hydrogen florid (HF) and sulfur trioxide (SO3) on the surface of platinum decorated graphene (PtG) using density functional theory. We found one optimized configuration for HF and two ones for SO3 upon adsorption on the surface of PtG. Our result show significant adsorption on PtG with calculated energy adsorption of -73.6 (-54.2 BSSE) kJ/mol for HF at its only position and -172.4 (-144.8 BSSE) and -62.7 (-53.7 BSSE) kJ/mol for SO3 at its two positions; P1 and P2, respectively), whereas there is weak physisorption of these analytes on pristine graphene (PG). Results of charge analyses reveled interesting net charge transfer; while the direction of charge is from HF to PtG, reverse direction is found for SO3 for its two configurations. To deep understand the concept of adsorption properties, we used orbital analyses including density of states for interaction of mentioned analytes on the surface of PtG.

  13. Synthesis and performance of bismuth trioxide nanoparticles for high energy gas generator use.

    PubMed

    Martirosyan, K S; Wang, L; Vicent, A; Luss, D

    2009-10-01

    Our experiments showed that the combustion of an Al-Bi2O3 nanoparticle mixture generated the highest pressure pulse among common nanothermite reactions and can potentially be used as a nanoenergetic gas generator. The combustion front propagation velocity and rate of energy release increased by up to three orders of magnitude when the particle size was reduced to a nanosize range for both the aluminum and the oxidizer. We developed a novel one-step (metal nitrate-glycine) combustion synthesis of nanostructured amorphous-like and highly crystalline bismuth trioxide nanoparticles. The combustion synthesis was conducted using a solution of molten bismuth nitrate as an oxidizer and glycine as a fuel. The glycine was completely combusted during the thermal decomposition of the bismuth nitrate pentahydrate and generated a temperature front that propagated through the sample. Increasing the fuel concentration increased the maximum combustion temperature from 280 to 1200 degrees C and the Bi2O3 particle size from 20 to 100 nm. The oxidizer/fuel ratio had a strong impact on the bismuth trioxide particle crystallinity. At low temperature (280 degrees C), amorphous-like bismuth trioxide nanoparticles formed, while at T > or =370 degrees C the structures were crystalline. A peak pressure of approximately 12 MPa and a thermal front propagating velocity of approximately 2500 m s(-1) were achieved during the combustion of an Al-Bi2O3 mixture containing 80 wt% of the synthesized Bi2O3 crystalline nanoparticles (size: 40-50 nm).

  14. Synthesis and performance of bismuth trioxide nanoparticles for high energy gas generator use

    NASA Astrophysics Data System (ADS)

    Martirosyan, K. S.; Wang, L.; Vicent, A.; Luss, D.

    2009-10-01

    Our experiments showed that the combustion of an Al-Bi2O3 nanoparticle mixture generated the highest pressure pulse among common nanothermite reactions and can potentially be used as a nanoenergetic gas generator. The combustion front propagation velocity and rate of energy release increased by up to three orders of magnitude when the particle size was reduced to a nanosize range for both the aluminum and the oxidizer. We developed a novel one-step (metal nitrate-glycine) combustion synthesis of nanostructured amorphous-like and highly crystalline bismuth trioxide nanoparticles. The combustion synthesis was conducted using a solution of molten bismuth nitrate as an oxidizer and glycine as a fuel. The glycine was completely combusted during the thermal decomposition of the bismuth nitrate pentahydrate and generated a temperature front that propagated through the sample. Increasing the fuel concentration increased the maximum combustion temperature from 280 to 1200 °C and the Bi2O3 particle size from 20 to 100 nm. The oxidizer/fuel ratio had a strong impact on the bismuth trioxide particle crystallinity. At low temperature (280 °C), amorphous-like bismuth trioxide nanoparticles formed, while at T>=370 °C the structures were crystalline. A peak pressure of ~12 MPa and a thermal front propagating velocity of ~2500 m s-1 were achieved during the combustion of an Al-Bi2O3 mixture containing 80 wt% of the synthesized Bi2O3 crystalline nanoparticles (size: 40-50 nm).

  15. Self-assembled flower-like antimony trioxide microstructures with high infrared reflectance performance

    SciTech Connect

    Ge, Shengsong; Yang, Xiaokun; Shao, Qian; Liu, Qingyun; Wang, Tiejun; Wang, Lingyun; Wang, Xiaojie

    2013-04-15

    A simple hydrothermal process was adopted to self-assembly prepare high infrared reflective antimony trioxide with three-dimensional flower-like microstructures. The morphologies of antimony trioxide microstructures were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high resolution transmission electron microscopy (HRTEM) respectively. It is also found that experimental parameters, such as NaOH concentration, surfactant concentration and volume ratio of ethanol–water played crucial roles in controlling the morphologies of Sb{sub 2}O{sub 3} microstructures. A possible growth mechanism of flower-like Sb{sub 2}O{sub 3} microstructure was proposed based on the experimental data. UV–vis–NIR spectra verified that the near infrared reflectivity of the obtained flower-like microstructures could averagely achieve as 92% with maximum reflectivity of 98%, obviously higher than that of other different morphologies of antimony trioxide microstructures. It is expected that the flower-like Sb{sub 2}O{sub 3} nanostructures have some applications in optical materials and heat insulation coatings. - Graphical abstract: Flower-like Sb{sub 2}O{sub 3} microstructures that composed of nanosheets with thickness of ca. 100 nm exhibit high reflectivity under UV–vis–NIR spectra. Highlights: ► Uniform flower-like microstructures were synthesized via simple hydrothermal reaction. ► The flower-like Sb{sub 2}O{sub 3} microstructures exhibited higher reflectivity than other morphologies under the UV–vis–NIR light. ► Influencing parameters on the Sb{sub 2}O{sub 3} morphologies have been discussed in detail. ► Possible mechanism leading to flower-like microstructures was proposed.

  16. Antimony trioxide

    Integrated Risk Information System (IRIS)

    Antimony trioxide ; CASRN 1309 - 64 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogeni

  17. Monoclinic sulfur cathode utilizing carbon for high-performance lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Jung, Sung Chul; Han, Young-Kyu

    2016-09-01

    Sulfur cathodes for lithium-sulfur batteries have been designed to be combined with conductive carbon because the insulating nature of sulfur causes low active material utilization and poor rate capability. This paper is the first to report that carbon can induce a phase transition in a sulfur cathode. The stable form of a sulfur crystal at ambient temperature is orthorhombic sulfur. We found that monoclinic sulfur becomes more stable than orthorhombic sulfur if carbon atoms penetrate into the sulfur at elevated temperatures and the carbon density exceeds a threshold of C0.3S8. The high stability of the carbon-containing monoclinic sulfur persists during lithiation and is attributed to locally formed linear SC3S chains with marked stability. This study provides a novel perspective on the role of carbon in the sulfur cathode and suggests control of the crystal phase of electrodes by composite elements as a new way of designing efficient electrode materials.

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

    NASA Astrophysics Data System (ADS)

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

    2015-01-01

    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.

  19. Efficient synthesis of plate-like crystalline hydrated tungsten trioxide thin films with highly improved electrochromic performance.

    PubMed

    Jiao, Zhihui; Wang, Xiu; Wang, Jinmin; Ke, Lin; Demir, Hilmi Volkan; Koh, Tien Wei; Sun, Xiao Wei

    2012-01-11

    Plate-like hydrated tungsten trioxide (3WO(3)·H(2)O) films were grown on a fluorine doped tin oxide (FTO) coated transparent conductive substrate via an efficient, facile and template-free hydrothermal method. The film exhibited a fast coloration/bleaching response (t(c90%) = 4.3 s and t(b90%) = 1.4 s) and a high coloration efficiency (112.7 cm(2) C(-1)), which were probably due to a large surface area. PMID:22083170

  20. Method for removing sulfur oxide from waste gases and recovering elemental sulfur

    DOEpatents

    Moore, Raymond H.

    1977-01-01

    A continuous catalytic fused salt extraction process is described for removing sulfur oxides from gaseous streams. The gaseous stream is contacted with a molten potassium sulfate salt mixture having a dissolved catalyst to oxidize sulfur dioxide to sulfur trioxide and molten potassium normal sulfate to solvate the sulfur trioxide to remove the sulfur trioxide from the gaseous stream. A portion of the sulfur trioxide loaded salt mixture is then dissociated to produce sulfur trioxide gas and thereby regenerate potassium normal sulfate. The evolved sulfur trioxide is reacted with hydrogen sulfide as in a Claus reactor to produce elemental sulfur. The process may be advantageously used to clean waste stack gas from industrial plants, such as copper smelters, where a supply of hydrogen sulfide is readily available.

  1. Sulfur rate control system

    SciTech Connect

    Bell, T.A.; Mullendore, M.G.; Kleinfeldt, T.E.; Walker, H.G. Jr.

    1993-07-20

    A sulfur rate control system is described for substantially optimizing particulate removal performance of an electrostatic precipitator in fluid communication with a flue carrying combustion products of a fossil fuel, comprising: an electrostatic precipitator having an inlet for receiving a flue gas: means for injecting sulfur trioxide into a flue for mixing with said flue gas at a location preceding entry of said flue gas into said electrostatic precipitator, said injection of sulfur trioxide being varied responsive to a proportional control signal; and, control means coupled to both said flue and said sulfur trioxide injection means for generating said proportional control signal, said control means including (1) means for measuring a sulfur dioxide concentration quantity in said flue gas at a location preceding said sulfur trioxide injection means, (2) means for measuring a flow rate of particulates in said flue gas at a location preceding said sulfur trioxide injection means, and (3) a controller for calculating a ratio between said sulfur dioxide concentration quantity and said flow rate of particulates, said ratio calculating controller having a first input coupled to said sulfur dioxide measuring means and a second input coupled to said particulate flow rate measuring means for generating said proportional control signal in proportion to a difference between a predetermined value and said ratio between said sulfur dioxide concentration quantity and said flow rate of particulates, said ratio controller having an output coupled to said sulfur trioxide injection means for maximizing particulate removal efficiency of said electrostatic precipitator.

  2. Arsenic Trioxide Injection

    MedlinePlus

    Arsenic trioxide is used to treat acute promyelocytic leukemia (APL; a type of cancer in which there ... worsened following treatment with other types of chemotherapy. Arsenic trioxide is in a class of medications called ...

  3. Effect of decabromodiphenyl ether and antimony trioxide on controlled pyrolysis of high-impact polystyrene mixed with polyolefins.

    PubMed

    Mitan, Nona Merry M; Bhaskar, Thallada; Hall, William J; Muto, Akinori; Williams, Paul T; Sakata, Yusaku

    2008-07-01

    The controlled pyrolysis of polyethylene/polypropylene/polystyrene mixed with brominated high-impact polystyrene containing decabromodiphenyl ether as a brominated flame-retardant with antimony trioxide as a synergist was performed. The effect of decabromodiphenyl ether and antimony trioxide on the formation of its congeners and their effect on distribution of pyrolysis products were investigated. The controlled pyrolysis significantly affected the decomposition behavior and the formation of products. Analysis with gas chromatograph with electron capture detector confirmed that the bromine content was rich in step 1 (oil 1) liquid products leaving less bromine content in the step 2 (oil 2) liquid products. In the presence of antimony containing samples, the major portion of bromine was observed in the form of antimony bromide and no flame-retardant species were found in oil 1. In the presence of synergist, the step 1 and step 2 oils contain both light and heavy compounds. In the absence of synergist, the heavy compounds in step 1 oil and light compounds in step 2 oils were observed. The presence of antimony bromide was confirmed in the step 1 oils but not in step 2 oils. PMID:18499216

  4. Upper critical field study in organic superconductor beta"-(ET) sulfur pentafluoride methylene difluoromethylene sulfur trioxide: Possibility of the FFLO state

    NASA Astrophysics Data System (ADS)

    Cho, Kyuil

    2009-07-01

    We conducted in-plane rf penetration depth measurements by using the tunnel diode oscillator technique. In the metal-free-all-organic superconductor beta"-(ET) 2SF5CH2 CF2SO3 the penetration depth measurements were carried out by changing the strength and direction of the magnetic field. When the magnetic field is applied perpendicular to the conducting planes, the Shubnikov-de Haas quantum oscillations are observed revealing the geometry of the Fermi surface. When the magnetic field is applied parallel to the conducting planes, the low temperature upper critical fields are found to exceed the Pauli paramagnetic limiting field calculated by using a semi-empirical method. Furthermore, we found the possible existence of an additional superconducting state which stablizes above the Pauli limiting field when the superconducting order parameter lowers its free energy by becoming spatially inhomogeneous in a high magnetic field. The additional superconducting state is called the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state and was predicted independently by Fulde and Ferrell [10] and by Larkin and Ovchinnikov [11] in 1964. The signature of the FFLO state observed in this thesis occurs as a kink during the superconducting vortex state (SCVS)-to-FFLO phase transition. In organic superconductors there have been several reports of the possible existence of the FFLO state [23, 24, 25, 62]. Even though these reports are all based on the fact that the upper critical field increases as the temperature decreases down to very low temperature, the obvious phase transition between the SCVS and the FFLO states has not been observed. To our best knowledge, the FFLO observation in beta"-(ET)2SF5CH2 CF2SO3 in this thesis is the first clear success which shows both the upper critical field enhancement at low temperature and the phase transition between the SCVS and the FFLO states.

  5. A New Use for High-Sulfur Coal

    NASA Technical Reports Server (NTRS)

    Lawson, D. D.; England, C.

    1982-01-01

    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.

  6. Sulfur nanocrystals anchored graphene composite with highly improved electrochemical performance for lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Zhang, Jun; Dong, Zimin; Wang, Xiuli; Zhao, Xuyang; Tu, Jiangping; Su, Qingmei; Du, Gaohui

    2014-12-01

    Two kinds of graphene-sulfur composites with 50 wt% of sulfur are prepared using hydrothermal method and thermal mixing, respectively. Transmission Electron Microscopy (TEM) and Energy Dispersive X-ray Spectra mapping show that sulfur nanocrystals with size of ∼5 nm dispersed on graphene sheets homogeneously for the sample prepared by hydrothermal method (NanoS@G). While for the thermal mixed graphene-sulfur composite (S-G mixture), sulfur shows larger and uneven size (50-200 nm). X-ray Photoelectron Spectra (XPS) reveals the strong chemical bonding between the sulfur nanocrystals and graphene. Comparing with the S-G mixture, the NanoS@G composite shows highly improved electrochemical performance as cathode for lithium-sulfur (Li-S) battery. The NanoS@G composite delivers an initial capacity of 1400 mAh g-1 with the sulfur utilization of 83.7% at a current density of 335 mA g-1. The capacity keeps above 720 mAh g-1 over 100 cycles. The strong adherence of the sulfur nanocrystals on graphene immobilizes sulfur and polysulfides species and suppressed the "shuttle effect", resulting higher coulombic efficiency and better capacity retention. Electrochemical impedance also suggests that the strong bonding enabled rapid electronic/ionic transport and improved electrochemical kinetics, therefore good rate capability is obtained. These results demonstrate that the NanoS@G composite is a very promising candidate for high-performance Li-S batteries.

  7. A mesoporous carbon–sulfur composite as cathode material for high rate lithium sulfur batteries

    SciTech Connect

    Choi, Hyunji; Zhao, Xiaohui; Kim, Dul-Sun; Ahn, Hyo-Jun; Kim, Ki-Won; Cho, Kwon-Koo; Ahn, Jou-Hyeon

    2014-10-15

    Highlights: • CMK-3 mesoporous carbon was synthesized as conducting reservoir for housing sulfur. • Sulfur/CMK-3 composites were prepared by two-stage thermal treatment. • The composite at 300 °C for 20 h shows improved electrochemical properties. - Abstract: Sulfur composite was prepared by encapsulating sulfur into CMK-3 mesoporous carbon with different heating times and then used as the cathode material for lithium sulfur batteries. Thermal treatment at 300 °C plays an important role in the sulfur encapsulation process. With 20 h of heating time, a portion of sulfur remained on the surface of carbon, whereas with 60 h of heating time, sulfur is confined deeply in the small pores of carbon that cannot be fully exploited in the redox reaction, thus causing low capacity. The S/CMK-3 composite with thermal treatment for 40 h at 300 °C contained 51.3 wt.% sulfur and delivered a high initial capacity of 1375 mA h g{sup −1} at 0.1 C. Moreover, it showed good capacity retention of 704 mA h g{sup −1} at 0.1 C and 578 mA h g{sup −1} at 2 C even after 100 cycles, which proves its potential as a cathode material for high capability lithium sulfur batteries.

  8. Infiltrating sulfur into a highly porous carbon sphere as cathode material for lithium–sulfur batteries

    SciTech Connect

    Zhao, Xiaohui; Kim, Dul-Sun; Ahn, Hyo-Jun; Kim, Ki-Won; Cho, Kwon-Koo; Ahn, Jou-Hyeon

    2014-10-15

    Highlights: • A highly porous carbon (HPC) with regular spherical morphology was synthesized. • Sulfur/HPC composites were prepared by melt–diffusion method. • Sulfur/HPC composites showed improved cyclablity and long-term cycle life. - Abstract: Sulfur composite material with a highly porous carbon sphere as the conducting container was prepared. The highly porous carbon sphere was easily synthesized with resorcinol–formaldehyde precursor as the carbon source. The morphology of the carbon was observed with field emission scanning electron microscope and transmission electron microscope, which showed a well-defined spherical shape. Brunauer–Emmett–Teller analysis indicated that it possesses a high specific surface area of 1563 m{sup 2} g{sup −1} and a total pore volume of 2.66 cm{sup 3} g{sup −1} with a bimodal pore size distribution, which allow high sulfur loading and easy transportation of lithium ions. Sulfur carbon composites with varied sulfur contents were prepared by melt–diffusion method and lithium sulfur cells with the sulfur composites showed improved cyclablity and long-term cycle life.

  9. Sulfur

    USGS Publications Warehouse

    Apodaca, L.E.

    2012-01-01

    In 2011, elemental sulfur and the byproduct sulfuric acid were produced at 109 operations in 29 states and the U.S. Virgin Islands. Total shipments were valued at about $1.6 billion. Elemental sulfur production was 8.2 Mt (9 million st); Louisiana and Texas accounted for about 53 percent of domestic production.

  10. Microbial degradation of high impact polystyrene (HIPS), an e-plastic with decabromodiphenyl oxide and antimony trioxide.

    PubMed

    Sekhar, Vini C; Nampoothiri, K Madhavan; Mohan, Arya J; Nair, Nimisha R; Bhaskar, Thallada; Pandey, Ashok

    2016-11-15

    Accumulation of electronic waste has increased catastrophically and out of that various plastic resins constitute one of the leading thrown out materials in the electronic machinery. Enrichment medium, containing high impact polystyrene (HIPS) with decabromodiphenyl oxide and antimony trioxide as sole carbon source, was used to isolate microbial cultures. The viability of these cultures in the e-plastic containing mineral medium was further confirmed by triphenyl tetrazolium chloride (TTC) reduction test. Four cultures were identified by 16S rRNA sequencing as Enterobacter sp., Citrobacter sedlakii, Alcaligenes sp. and Brevundimonas diminuta. Biodegradation experiments were carried out in flask level and gelatin supplementation (0.1% w/v) along with HIPS had increased the degradation rate to a maximum of 12.4% (w/w) within 30days. This is the first report for this kind of material. The comparison of FTIR, NMR, and TGA analysis of original and degraded e-plastic films revealed structural changes under microbial treatment. Polystyrene degradation intermediates in the culture supernatant were also detected using HPLC analysis. The gravity of biodegradation was validated by morphological changes under scanning electron microscope. All isolates displayed depolymerase activity to substantiate enzymatic degradation of e-plastic. PMID:27434738

  11. Microbial degradation of high impact polystyrene (HIPS), an e-plastic with decabromodiphenyl oxide and antimony trioxide.

    PubMed

    Sekhar, Vini C; Nampoothiri, K Madhavan; Mohan, Arya J; Nair, Nimisha R; Bhaskar, Thallada; Pandey, Ashok

    2016-11-15

    Accumulation of electronic waste has increased catastrophically and out of that various plastic resins constitute one of the leading thrown out materials in the electronic machinery. Enrichment medium, containing high impact polystyrene (HIPS) with decabromodiphenyl oxide and antimony trioxide as sole carbon source, was used to isolate microbial cultures. The viability of these cultures in the e-plastic containing mineral medium was further confirmed by triphenyl tetrazolium chloride (TTC) reduction test. Four cultures were identified by 16S rRNA sequencing as Enterobacter sp., Citrobacter sedlakii, Alcaligenes sp. and Brevundimonas diminuta. Biodegradation experiments were carried out in flask level and gelatin supplementation (0.1% w/v) along with HIPS had increased the degradation rate to a maximum of 12.4% (w/w) within 30days. This is the first report for this kind of material. The comparison of FTIR, NMR, and TGA analysis of original and degraded e-plastic films revealed structural changes under microbial treatment. Polystyrene degradation intermediates in the culture supernatant were also detected using HPLC analysis. The gravity of biodegradation was validated by morphological changes under scanning electron microscope. All isolates displayed depolymerase activity to substantiate enzymatic degradation of e-plastic.

  12. A lithium-sulfur cathode with high sulfur loading and high capacity per area: a binder-free carbon fiber cloth-sulfur material.

    PubMed

    Miao, Lixiao; Wang, Weikun; Yuan, Keguo; Yang, Yusheng; Wang, Anbang

    2014-11-11

    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.

  13. Reinforced Conductive Confinement of Sulfur for Robust and High-Performance Lithium-Sulfur Batteries.

    PubMed

    Lai, Chao; Wu, Zhenzhen; Gu, Xingxing; Wang, Chao; Xi, Kai; Kumar, R Vasant; Zhang, Shanqing

    2015-11-01

    Sulfur is an attractive cathode material in energy storage devices due to its high theoretical capacity of 1672 mAh g(-1). However, practical application of lithium-sulfur (Li-S) batteries can be achieved only when the major barriers, including the shuttling effect of polysulfides (Li2Sx, x = 3-8), significant volume change (∼80%), and the resultant rapid deterioration of electrodes, are tackled. Here, we propose an "inside-out" synthesis strategy by mimicking the structure of the pomegranate fruit to achieve conductive confinement of sulfur to address these issues. In the proposed pomegranate-like structure, sulfur and carbon nanotubes composite is encapsulated by the in situ formed amorphous carbon network, which allows the regeneration of electroactive material sulfur and the confinement of the sulfur as well as the lithium polysulfide within the electrical conductive carbon network. Consequently, a highly robust sulfur cathode is obtained, delivering remarkable performance in a Li-S battery. The obtained composite cathode shows a reversible capacity of 691 mAh g(-1) after 200 cycles with impressive cycle stability at the current density of 1600 mA g(-1). PMID:26470838

  14. Three-dimensional porous carbon composites containing high sulfur nanoparticle content for high-performance lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Li, Guoxing; Sun, Jinhua; Hou, Wenpeng; Jiang, Shidong; Huang, Yong; Geng, Jianxin

    2016-02-01

    Sulfur is a promising cathode material for lithium-sulfur batteries because of its high theoretical capacity (1,675 mA h g-1) however, its low electrical conductivity and the instability of sulfur-based electrodes limit its practical application. Here we report a facile in situ method for preparing three-dimensional porous graphitic carbon composites containing sulfur nanoparticles (3D S@PGC). With this strategy, the sulfur content of the composites can be tuned to a high level (up to 90 wt%). Because of the high sulfur content, the nanoscale distribution of the sulfur particles, and the covalent bonding between the sulfur and the PGC, the developed 3D S@PGC cathodes exhibit excellent performance, with a high sulfur utilization, high specific capacity (1,382, 1,242 and 1,115 mA h g-1 at 0.5, 1 and 2 C, respectively), long cycling life (small capacity decay of 0.039% per cycle over 1,000 cycles at 2 C) and excellent rate capability at a high charge/discharge current.

  15. Three-dimensional porous carbon composites containing high sulfur nanoparticle content for high-performance lithium–sulfur batteries

    PubMed Central

    Li, Guoxing; Sun, Jinhua; Hou, Wenpeng; Jiang, Shidong; Huang, Yong; Geng, Jianxin

    2016-01-01

    Sulfur is a promising cathode material for lithium–sulfur batteries because of its high theoretical capacity (1,675 mA h g−1); however, its low electrical conductivity and the instability of sulfur-based electrodes limit its practical application. Here we report a facile in situ method for preparing three-dimensional porous graphitic carbon composites containing sulfur nanoparticles (3D S@PGC). With this strategy, the sulfur content of the composites can be tuned to a high level (up to 90 wt%). Because of the high sulfur content, the nanoscale distribution of the sulfur particles, and the covalent bonding between the sulfur and the PGC, the developed 3D S@PGC cathodes exhibit excellent performance, with a high sulfur utilization, high specific capacity (1,382, 1,242 and 1,115 mA h g−1 at 0.5, 1 and 2 C, respectively), long cycling life (small capacity decay of 0.039% per cycle over 1,000 cycles at 2 C) and excellent rate capability at a high charge/discharge current. PMID:26830732

  16. Porous spherical polyacrylonitrile-carbon nanocomposite with high loading of sulfur for lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Sohn, Hiesang; Gordin, Mikhail L.; Regula, Michael; Kim, Dong Hyeon; Jung, Yoon Seok; Song, Jiangxuan; Wang, Donghai

    2016-01-01

    Pyrolyzed porous spherical composites of polyacrylonitrile-Ketjenblack carbon and sulfur (pPAN-KB/S) with a high sulfur content (ca. 72%) and enhanced conductivity and porosity (pore volume: 1.42 cm3/g; BET surface area: 727 m2/g) were prepared by an aerosol-assisted process and applied as cathode for lithium-sulfur batteries. Electrochemical tests showed that the pPAN-KB/S composite exhibited a high capacity of 866 mAh/g (based on sulfur) after 100 cycles at 0.5C (1C = 1.68 A/g) and a good rate performance at high current density (431 mAh/g at 5C). In addition, a pPAN-KB/S composite electrode with high sulfur loading (ca. 4.4 mg-S/cm2) exhibited impressive electrochemical performance with a reversible capacity of 513 mAh/g and 576 mAh/cm3 (based on sulfur) and a coulombic efficiency >99% after 100 cycles at 0.5C.

  17. Sulfur removal from high-sulfur Illinois coal by low-temperature perchloroethylene (PCE) extraction

    SciTech Connect

    Chou, M.I.M.

    1991-01-01

    A pre-combustion coal desulfurization process at 120{degree}C using perchloroethylene (PCE) to remove up to 70% of the organic sulfur has been developed by the Midwest Ore Processing Co. (MWOPC). However, this process has not yet proven to be as successful with Illinois coals as it has for Ohio and Indiana coals. The organic sulfur removal has been achieved only with highly oxidized Illinois coals containing high sulfatic sulfur. A logical explanation for this observation is vital to successful process optimization for the use of Illinois coals. In addition, the high levels of organic sulfur removals observed by the MWOPC may be due to certain errors involved in the ASTM data interpretation; this needs verification. For example, elemental sulfur extracted by the PCE may be derived from pyrite oxidation during coal pre-oxidation, but it may be interpreted as organic sulfur removed by the PCE using ASTM analysis. The goals of this research are: (1) to independently confirm and possibly to improve the organic sulfur removal from Illinois coals with the PCE desulfurization process reported by the MWOPC, (2) to verify the forms-of-sulfur determination using the ASTM method for the PCE process evaluation, and (3) to determine the suitability of Illinois coals for use in the PCE desulfurization process. This project involves the Illinois State Geological Survey (ISGS), Eastern Illinois University (EIU), the University of Illinois-Urbana/Champaign (UI-UC), and the University of Kentucky, Lexington (UK). This is the first year of a two-year project.

  18. Sulfur/three-dimensional graphene composite for high performance lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Xu, Chunmei; Wu, Yishan; Zhao, Xuyang; Wang, Xiuli; Du, Gaohui; Zhang, Jun; Tu, Jiangping

    2015-02-01

    A sulfur/graphene composite is prepared by loading elemental sulfur into three-dimensional graphene (3D graphene), which is assembled using a metal ions assisted hydrothermal method. When used as cathode materials for lithium-sulfur (Li-S) batteries, the sulfur/graphene composite (S@3D-graphene) with 73 wt % sulfur shows a significantly enhanced cycling performance (>700 mAh g-1 after 100 cycles at 0.1C rate with a Coulombic efficiency > 96%) as well as high rate capability with a capacity up to 500 mAh g-1 at 2C rate (3.35 A g-1). The superior electrochemical performance could be attributed to the highly porous structure of three-dimensional graphene that not only enables stable and continue pathway for rapid electron and ion transportation, but also restrain soluble polysulfides and suppress the "shuttle effect". Moreover, the robust structure of 3D graphene can keep cathode integrity and accommodate the volume change during high-rate charge/discharge processes, making it a promising candidate as cathode for high performance Li-S batteries.

  19. Biomimetic Ant-Nest Electrode Structures for High Sulfur Ratio Lithium-Sulfur Batteries.

    PubMed

    Ai, Guo; Dai, Yiling; Mao, Wenfeng; Zhao, Hui; Fu, Yanbao; Song, Xiangyun; En, Yunfei; Battaglia, Vincent S; Srinivasan, Venkat; Liu, Gao

    2016-09-14

    The lithium-sulfur (Li-S) rechargeable battery has the benefit of high gravimetric energy density and low cost. Significant research currently focuses on increasing the sulfur loading and sulfur/inactive-materials ratio, to improve life and capacity. Inspired by nature's ant-nest structure, this research results in a novel Li-S electrode that is designed to meet both goals. With only three simple manufacturing-friendly steps, which include slurry ball-milling, doctor-blade-based laminate casting, and the use of the sacrificial method with water to dissolve away table salt, the ant-nest design has been successfully recreated in an Li-S electrode. The efficient capabilities of the ant-nest structure are adopted to facilitate fast ion transportation, sustain polysulfide dissolution, and assist efficient precipitation. High cycling stability in the Li-S batteries, for practical applications, has been achieved with up to 3 mg·cm(-2) sulfur loading. Li-S electrodes with up to a 85% sulfur ratio have also been achieved for the efficient design of this novel ant-nest structure. PMID:27501313

  20. Biomimetic Ant-Nest Electrode Structures for High Sulfur Ratio Lithium-Sulfur Batteries.

    PubMed

    Ai, Guo; Dai, Yiling; Mao, Wenfeng; Zhao, Hui; Fu, Yanbao; Song, Xiangyun; En, Yunfei; Battaglia, Vincent S; Srinivasan, Venkat; Liu, Gao

    2016-09-14

    The lithium-sulfur (Li-S) rechargeable battery has the benefit of high gravimetric energy density and low cost. Significant research currently focuses on increasing the sulfur loading and sulfur/inactive-materials ratio, to improve life and capacity. Inspired by nature's ant-nest structure, this research results in a novel Li-S electrode that is designed to meet both goals. With only three simple manufacturing-friendly steps, which include slurry ball-milling, doctor-blade-based laminate casting, and the use of the sacrificial method with water to dissolve away table salt, the ant-nest design has been successfully recreated in an Li-S electrode. The efficient capabilities of the ant-nest structure are adopted to facilitate fast ion transportation, sustain polysulfide dissolution, and assist efficient precipitation. High cycling stability in the Li-S batteries, for practical applications, has been achieved with up to 3 mg·cm(-2) sulfur loading. Li-S electrodes with up to a 85% sulfur ratio have also been achieved for the efficient design of this novel ant-nest structure.

  1. Method of removing and recovering elemental sulfur from highly reducing gas streams containing sulfur gases

    DOEpatents

    Gangwal, Santosh K.; Nikolopoulos, Apostolos A.; Dorchak, Thomas P.; Dorchak, Mary Anne

    2005-11-08

    A method is provided for removal of sulfur gases and recovery of elemental sulfur from sulfur gas containing supply streams, such as syngas or coal gas, by contacting the supply stream with a catalyst, that is either an activated carbon or an oxide based catalyst, and an oxidant, such as sulfur dioxide, in a reaction medium such as molten sulfur, to convert the sulfur gases in the supply stream to elemental sulfur, and recovering the elemental sulfur by separation from the reaction medium.

  2. Graphene-wrapped sulfur particles as a rechargeable lithium-sulfur battery cathode material with high capacity and cycling stability.

    PubMed

    Wang, Hailiang; Yang, Yuan; Liang, Yongye; Robinson, Joshua Tucker; Li, Yanguang; Jackson, Ariel; Cui, Yi; Dai, Hongjie

    2011-07-13

    We report the synthesis of a graphene-sulfur composite material by wrapping poly(ethylene glycol) (PEG) coated submicrometer sulfur particles with mildly oxidized graphene oxide sheets decorated by carbon black nanoparticles. The PEG and graphene coating layers are important to accommodating volume expansion of the coated sulfur particles during discharge, trapping soluble polysulfide intermediates, and rendering the sulfur particles electrically conducting. The resulting graphene-sulfur composite showed high and stable specific capacities up to ∼600 mAh/g over more than 100 cycles, representing a promising cathode material for rechargeable lithium batteries with high energy density.

  3. Synthesis of novel organosilicon compounds possessing highly substituted imidazole core catalyzed by antimony trioxide.

    PubMed

    Safa, Kazem D; Allahvirdinesbat, Maryam; Namazi, Hassan

    2015-02-01

    A general synthetic route for the exclusive preparation of tetrasubstituted imidazoles, possessing benzylic methyl groups has been developed using Sb2O3 via solvent-free, one-pot reaction conditions. Detailed results from our investigation on the bromination of the benzylic methyl groups of imidazoles are described. The products generated during this study were utilized as substrates for the synthesis of organosilicon-containing imidazoles. Synthesis of tris(triorganosilyl)methylimidazole derivatives was carried out using organolithium reagents (RSiMe2)3CLi, (R= H, Me, Ph) prepared via metalation of (RSiMe2)3CH with lithiumdiisopropylamide or methyllithium in THF, in excellent yields. (RSiMe2)3CLi, (R= Me, Ph) were treated with formylated imidazole to afford imidazole containing 2,2-bis(organosilyl)ethenyl groups. 2-(4-(2,2-bis(trimethylsilyl)vinyl)phenyl)-1,4,5-triphenyl-1H-imidazole was obtained via Peterson reaction in high yield. However, compound 2-(4-(2,2-bis(dimethyl(phenyl)silyl)vinyl)phenyl)-1,4,5-triphenyl-1H-imidazole was obtained in low yield likely because of the steric hindrance of the (PhSiMe2)3C- group.

  4. Advanced Sulfur Cathode Enabled by Highly Crumpled Nitrogen-Doped Graphene Sheets for High-Energy-Density Lithium-Sulfur Batteries.

    PubMed

    Song, Jiangxuan; Yu, Zhaoxin; Gordin, Mikhail L; Wang, Donghai

    2016-02-10

    Herein, we report a synthesis of highly crumpled nitrogen-doped graphene sheets with ultrahigh pore volume (5.4 cm(3)/g) via a simple thermally induced expansion strategy in absence of any templates. The wrinkled graphene sheets are interwoven rather than stacked, enabling rich nitrogen-containing active sites. Benefiting from the unique pore structure and nitrogen-doping induced strong polysulfide adsorption ability, lithium-sulfur battery cells using these wrinkled graphene sheets as both sulfur host and interlayer achieved a high capacity of ∼1000 mAh/g and exceptional cycling stability even at high sulfur content (≥80 wt %) and sulfur loading (5 mg sulfur/cm(2)). The high specific capacity together with the high sulfur loading push the areal capacity of sulfur cathodes to ∼5 mAh/cm(2), which is outstanding compared to other recently developed sulfur cathodes and ideal for practical applications.

  5. A dual coaxial nanocable sulfur composite for high-rate lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Li, Zhen; Yuan, Lixia; Yi, Ziqi; Liu, Yang; Xin, Ying; Zhang, Zhaoliang; Huang, Yunhui

    2014-01-01

    Lithium-sulfur batteries have great potential for some high energy applications such as in electric vehicles and smart grids due to their high capacity, natural abundance, low cost and environmental friendliness. But they suffer from rapid capacity decay and poor rate capability. The problems are mainly related to the dissolution of the intermediate polysulfides in the electrolyte, and to the poor conductivity of sulfur and the discharge products. In this work, we propose a novel dual coaxial nanocable sulfur composite fabricated with multi-walled nanotubes (MWCNT), nitrogen-doped porous carbon (NPC) and polyethylene glycol (PEG), i.e. MWCNTs@S/NPC@PEG nanocable, as a cathode material for Li-S batteries. In such a coaxial structure, the middle N-doped carbon with hierarchical porous structure provides a nanosized capsule to contain and hold the sulfur particles; the inner MWCNTs and the outer PEG layer can further ensure the fast electronic transport and prevent the dissolution of the polysulfides into the electrolyte, respectively. The as-designed MWCNT@S/NPC@PEG composite shows good cycling stability and excellent rate capability. The capacity is retained at 527 mA h g-1 at 1 C after 100 cycles, and 791 mA h g-1 at 0.5 C and 551 mA h g-1 at 2 C after 50 cycles. Especially, the high-rate capability is outstanding with 400 mA h g-1 at 5 C.Lithium-sulfur batteries have great potential for some high energy applications such as in electric vehicles and smart grids due to their high capacity, natural abundance, low cost and environmental friendliness. But they suffer from rapid capacity decay and poor rate capability. The problems are mainly related to the dissolution of the intermediate polysulfides in the electrolyte, and to the poor conductivity of sulfur and the discharge products. In this work, we propose a novel dual coaxial nanocable sulfur composite fabricated with multi-walled nanotubes (MWCNT), nitrogen-doped porous carbon (NPC) and polyethylene glycol (PEG

  6. High pressure sulfuric acid decomposition experiments for the sulfur-iodine thermochemical cycle.

    SciTech Connect

    Velasquez, Carlos E; Reay, Andrew R.; Andazola, James C.; Naranjo, Gerald E.; Gelbard, Fred

    2005-09-01

    A series of three pressurized sulfuric acid decomposition tests were performed to (1) obtain data on the fraction of sulfuric acid catalytically converted to sulfur dioxide, oxygen, and water as a function of temperature and pressure, (2) demonstrate real-time measurements of acid conversion for use as process control, (3) obtain multiple measurements of conversion as a function of temperature within a single experiment, and (4) assess rapid quenching to minimize corrosion of metallic components by undecomposed acid. All four of these objectives were successfully accomplished. This report documents the completion of the NHI milestone on high pressure H{sub 2}SO{sub 4} decomposition tests for the Sulfur-Iodine (SI) thermochemical cycle project. All heated sections of the apparatus, (i.e. the boiler, decomposer, and condenser) were fabricated from Hastelloy C276. A ceramic acid injection tube and a ceramic-sheathed thermocouple were used to minimize corrosion of hot liquid acid on the boiler surfaces. Negligible fracturing of the platinum on zirconia catalyst was observed in the high temperature decomposer. Temperature measurements at the exit of the decomposer and at the entry of the condenser indicated that the hot acid vapors were rapidly quenched from about 400 C to less than 20 C within a 14 cm length of the flow path. Real-time gas flow rate measurements of the decomposition products provided a direct measurement of acid conversion. Pressure in the apparatus was preset by a pressure-relief valve that worked well at controlling the system pressure. However, these valves sometimes underwent abrupt transitions that resulted in rapidly varying gas flow rates with concomitant variations in the acid conversion fraction.

  7. Mesoporous carbon-carbon nanotube-sulfur composite microspheres for high-areal-capacity lithium-sulfur battery cathodes.

    PubMed

    Xu, Terrence; Song, Jiangxuan; Gordin, Mikhail L; Sohn, Hiesang; Yu, Zhaoxin; Chen, Shuru; Wang, Donghai

    2013-11-13

    Lithium-sulfur (Li-S) batteries offer theoretical energy density much higher than that of lithium-ion batteries, but their development faces significant challenges. Mesoporous carbon-sulfur composite microspheres are successfully synthesized by combining emulsion polymerization and the evaporation-induced self-assembly (EISA) process. Such materials not only exhibit high sulfur-specific capacity and excellent retention as Li-S cathodes but also afford much improved tap density, sulfur content, and areal capacity necessary for practical development of high-energy-density Li-S batteries. In addition, when incorporated with carbon nanotubes (CNTs) to form mesoporous carbon-CNT-sulfur composite microspheres, the material demonstrated superb battery performance even at a high current density of 2.8 mA/cm(2), with a reversible capacity over 700 mAh/g after 200 cycles.

  8. Construction of carbon nanodots/tungsten trioxide and their visible-light sensitive photocatalytic activity.

    PubMed

    Yan, Fanyong; Kong, Depeng; Fu, Yang; Ye, Qianghua; Wang, Yinyin; Chen, Li

    2016-03-15

    Herein we designed a simple and effective method for synthesizing carbon nanodots/tungsten trioxide nanocomposite with high photocatalytic activity. The as-prepared carbon nanodots/ tungsten trioxide has strong photoabsorption under visible light irradiation. Then, carbon nanodots/tungsten trioxide was successfully applied to the degradation of methylene blue. The photodegradation efficiency of methylene blue can be reached as high as 100% after 0.5 h visible light illumination. In addition, carbon nanodots/tungsten trioxide could also be used to degrade rhodamine B and methyl orange. Most importantly, the photocatalytic activity of carbon nanodots/tungsten trioxide did not exhibit obvious changes after five cycles. The results indicate that carbon nanodots/tungsten trioxide has potential applications in the degradation of organic pollutants in industrial waste water.

  9. Sulfur-oxygen processes on Io

    NASA Technical Reports Server (NTRS)

    Nelson, Robert M.; Smythe, William D.

    1987-01-01

    Laboratory studies of irradiated sulfur dioxide frost have found that sulfur trioxide should be formed as a consequence of the irradiation process. The spectral reflectance of solid sulfur trioxide was measured in the laboratory and it was found that the compound has strong absorption features at 3.37 and 3.70 microns. These features are not present in the spectral geometric albedo of Io. This is interpreted as an indication that sulfur trioxide may exist in such limited abundance that it is undetectable in disk averaged spectrophotometry. It is suggested that the Near-Infrared Mapping Spectrometer on the Galileo spacecraft should be able to identify condensed sulfur trioxide on Io particularly in regions bordering the sulfur dioxide deposits. The presence of elemental sulfur on Io's surface has been questioned on several grounds, most notably the suggested production process (quenched molten sulfur extrusions) and the effect of radiation (particularly X-rays) on some of the allotropes. Mixtures of sulfur allotropes were produced in the laboratory by quenching molten sulfur and it was found that the spectra indicate the presence of certain red-colored allotropes which are preserved upon quenching. The color of the sulfur glass produced is redder when the temperature of the original melt is higher. This is consistent with the suggestion that Io's spectral geometric albedo can be partly explained by the presence of quenched sulfur glasses.

  10. Janus Separator of Polypropylene‐Supported Cellular Graphene Framework for Sulfur Cathodes with High Utilization in Lithium–Sulfur Batteries

    PubMed Central

    Peng, Hong‐Jie; Wang, Dai‐Wei; Cheng, Xin‐Bing; Yuan, Zhe; Wei, Fei

    2016-01-01

    Owing to the conversion chemistry of the sulfur cathode, the lithium–sulfur (Li–S) batteries exhibit high theoretical energy density. However, the intrinsic mobile redox centers during the sulfur/Li2S‐to‐lithium polysulfides solid‐to‐liquid phase transition induce low sulfur utilization and poor cycling life. Herein, the Janus separator of mesoporous cellular graphene framework (CGF)/polypropylene membrane to promote the utilization of sulfur cathode is introduced. The porous polypropylene membrane serves as an insulating substrate in contact with lithium anode while CGFs that possess high electrical conductivity of 100 S cm−1, a large mesopore volume of 3.1 cm3 g−1, and a huge surface area of 2120 m2 g−1 are adhered on cathode side to reactivate the shuttling‐back polysulfides and to preserve the ion channels. Therefore, the Li–S cell with the “two‐face” CGF Janus separator exhibit a high initial capacity of 1109 mAh g−1 and superior capacity preserved upon 800 mAh g−1 after 250 cycles at 0.2 C, which is 40% higher on sulfur utilization efficiency than the corresponding results with routine polypropylene separators. There are significant improvements on capacity as well as electrochemical kinetics. A very high areal capacity of 5.5 mAh cm−2 combined with high sulfur content of 80% and areal loading amount of 5.3 mg cm−2 is achieved for such advanced configuration. The negative impact of shuttle mechanism on lowering the utilization of sulfur and overall energy density of a Li–S battery is well eliminated by applying CGF separators. Consequently, employing carbonaceous materials as Janus face of separators enlightens new opportunities for improving the utilization of active materials and energy density of devices that involve complex phase evolution and conversion electrochemistry. PMID:27774384

  11. Sulfur-infiltrated graphene-based layered porous carbon cathodes for high-performance lithium-sulfur batteries.

    PubMed

    Yang, Xi; Zhang, Long; Zhang, Fan; Huang, Yi; Chen, Yongsheng

    2014-05-27

    Because of advantages such as excellent electronic conductivity, high theoretical specific surface area, and good mechanical flexibility, graphene is receiving increasing attention as an additive to improve the conductivity of sulfur cathodes in lithium-sulfur (Li-S) batteries. However, graphene is not an effective substrate material to confine the polysulfides in cathodes and stable the cycling. Here, we designed and synthesized a graphene-based layered porous carbon material for the impregnation of sulfur as cathode for Li-S battery. In this composite, a thin layer of porous carbon uniformly covers both surfaces of the graphene and sulfur is highly dispersed in its pores. The high specific surface area and pore volume of the porous carbon layers not only can achieve a high sulfur loading in highly dispersed amorphous state, but also can act as polysulfide reservoirs to alleviate the shuttle effect. When used as the cathode material in Li-S batteries, with the help of the thin porous carbon layers, the as-prepared materials demonstrate a better electrochemical performance and cycle stability compared with those of graphene/sulfur composites.

  12. A Free-Standing Sulfur/Nitrogen-Doped Carbon Nanotube Electrode for High-Performance Lithium/Sulfur Batteries

    NASA Astrophysics Data System (ADS)

    Zhao, Yan; Yin, Fuxing; Zhang, Yongguang; Zhang, Chengwei; Mentbayeva, Almagul; Umirov, Nurzhan; Xie, Hongxian; Bakenov, Zhumabay

    2015-11-01

    A free-standing sulfur/nitrogen-doped carbon nanotube (S/N-CNT) composite prepared via a simple solution method was first studied as a cathode material for lithium/sulfur batteries. By taking advantage of the self-weaving behavior of N-CNT, binders and current collectors are rendered unnecessary in the cathode, thereby simplifying its manufacturing and increasing the sulfur weight ratio in the electrode. Transmission electronic microscopy showed the formation of a highly developed core-shell tubular structure consisting of S/N-CNT composite with uniform sulfur coating on the surface of N-CNT. As a core in the composite, the N-CNT with N functionalization provides a highly conductive and mechanically flexible framework, enhancing the electronic conductivity and consequently the rate capability of the material.

  13. A Free-Standing Sulfur/Nitrogen-Doped Carbon Nanotube Electrode for High-Performance Lithium/Sulfur Batteries.

    PubMed

    Zhao, Yan; Yin, Fuxing; Zhang, Yongguang; Zhang, Chengwei; Mentbayeva, Almagul; Umirov, Nurzhan; Xie, Hongxian; Bakenov, Zhumabay

    2015-12-01

    A free-standing sulfur/nitrogen-doped carbon nanotube (S/N-CNT) composite prepared via a simple solution method was first studied as a cathode material for lithium/sulfur batteries. By taking advantage of the self-weaving behavior of N-CNT, binders and current collectors are rendered unnecessary in the cathode, thereby simplifying its manufacturing and increasing the sulfur weight ratio in the electrode. Transmission electronic microscopy showed the formation of a highly developed core-shell tubular structure consisting of S/N-CNT composite with uniform sulfur coating on the surface of N-CNT. As a core in the composite, the N-CNT with N functionalization provides a highly conductive and mechanically flexible framework, enhancing the electronic conductivity and consequently the rate capability of the material.

  14. A Sheet-like Carbon Matrix Hosted Sulfur as Cathode for High-performance Lithium-Sulfur Batteries

    NASA Astrophysics Data System (ADS)

    Lu, Songtao; Chen, Yan; Zhou, Jia; Wang, Zhida; Wu, Xiaohong; Gu, Jian; Zhang, Xiaoping; Pang, Aimin; Jiao, Zilong; Jiang, Lixiang

    2016-02-01

    Lithium-sulfur (Li-S) batteries are a promising candidate of next generation energy storage systems owing to its high theoretical capacity and energy density. However, to date, its commercial application was hindered by the inherent problems of sulfur cathode. Additionally, with the rapid decline of non-renewable resources and active appeal of green chemistry, the intensive research of new electrode materials was conducted worldwide. We have obtained a sheet-like carbon material (shaddock peel carbon sheets SPCS) from organic waste shaddock peel, which can be used as the conductive carbon matrix for sulfur-based cathodes. Furthermore, the raw materials are low-cost, truly green and recyclable. As a result, the sulfur cathode made with SPCS (SPCS-S), can deliver a high reversible capacity of 722.5 mAh g-1 at 0.2 C after 100 cycles with capacity recuperability of ~90%, demonstrating that the SPCS-S hybrid is of great potential as the cathode for rechargeable Li-S batteries. The high electrochemical performance of SPCS-S hybrid could be attributed to the sheet-like carbon network with large surface area and high conductivity of the SPCS, in which the carbon sheets enable the uniform distribution of sulfur, better ability to trap the soluble polysulfides and accommodate volume expansion/shrinkage of sulfur during repeated charge/discharge cycles.

  15. Nitrogen, sulfur-codoped graphene sponge as electroactive carbon interlayer for high-energy and -power lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Xing, Ling-Bao; Xi, Kai; Li, Qiuyan; Su, Zhong; Lai, Chao; Zhao, Xinsheng; Kumar, R. Vasant

    2016-01-01

    Sulfur is an attractive cathode material in energy storage devices since its high theoretical capacity of 1672 mAh g-1. However, practical application of lithium sulfur (Li-S) batteries can be achieved only when the major barriers, including the insulating nature of element sulfur and shuttling effect of polysulfides (Li2Sx, x = 3-8), are tackled. Here, nitrogen, sulfur-codoped (N,S-codoped) sponge-like graphene, which presents a high reversible capacity, is used as electroactive interlayer for Li-S batteries to address these issues. An impressive high capacity of 2193.2 mAh g-1 can be obtained for the sulfur cathodes with such an interlayer at the rate of 0.2C, and it can be stably maintained at 829.4 mAh g-1 at the rate of 6C, for which the contribution from the electroactive interlayer is ca. 30.0%. High energy density of 418.5 Wh Kg-1 still can be released at the power density of 4.55 kW kg-1 (6C) based on the total mass of the sulfur cathode and interlayer for the assembled Li-S batteries.

  16. A Sheet-like Carbon Matrix Hosted Sulfur as Cathode for High-performance Lithium-Sulfur Batteries.

    PubMed

    Lu, Songtao; Chen, Yan; Zhou, Jia; Wang, Zhida; Wu, Xiaohong; Gu, Jian; Zhang, Xiaoping; Pang, Aimin; Jiao, Zilong; Jiang, Lixiang

    2016-01-01

    Lithium-sulfur (Li-S) batteries are a promising candidate of next generation energy storage systems owing to its high theoretical capacity and energy density. However, to date, its commercial application was hindered by the inherent problems of sulfur cathode. Additionally, with the rapid decline of non-renewable resources and active appeal of green chemistry, the intensive research of new electrode materials was conducted worldwide. We have obtained a sheet-like carbon material (shaddock peel carbon sheets SPCS) from organic waste shaddock peel, which can be used as the conductive carbon matrix for sulfur-based cathodes. Furthermore, the raw materials are low-cost, truly green and recyclable. As a result, the sulfur cathode made with SPCS (SPCS-S), can deliver a high reversible capacity of 722.5 mAh g(-1) at 0.2 C after 100 cycles with capacity recuperability of ~90%, demonstrating that the SPCS-S hybrid is of great potential as the cathode for rechargeable Li-S batteries. The high electrochemical performance of SPCS-S hybrid could be attributed to the sheet-like carbon network with large surface area and high conductivity of the SPCS, in which the carbon sheets enable the uniform distribution of sulfur, better ability to trap the soluble polysulfides and accommodate volume expansion/shrinkage of sulfur during repeated charge/discharge cycles. PMID:26842015

  17. A Sheet-like Carbon Matrix Hosted Sulfur as Cathode for High-performance Lithium-Sulfur Batteries

    PubMed Central

    Lu, Songtao; Chen, Yan; Zhou, Jia; Wang, Zhida; Wu, Xiaohong; Gu, Jian; Zhang, Xiaoping; Pang, Aimin; Jiao, Zilong; Jiang, Lixiang

    2016-01-01

    Lithium-sulfur (Li-S) batteries are a promising candidate of next generation energy storage systems owing to its high theoretical capacity and energy density. However, to date, its commercial application was hindered by the inherent problems of sulfur cathode. Additionally, with the rapid decline of non-renewable resources and active appeal of green chemistry, the intensive research of new electrode materials was conducted worldwide. We have obtained a sheet-like carbon material (shaddock peel carbon sheets SPCS) from organic waste shaddock peel, which can be used as the conductive carbon matrix for sulfur-based cathodes. Furthermore, the raw materials are low-cost, truly green and recyclable. As a result, the sulfur cathode made with SPCS (SPCS-S), can deliver a high reversible capacity of 722.5 mAh g−1 at 0.2 C after 100 cycles with capacity recuperability of ~90%, demonstrating that the SPCS-S hybrid is of great potential as the cathode for rechargeable Li-S batteries. The high electrochemical performance of SPCS-S hybrid could be attributed to the sheet-like carbon network with large surface area and high conductivity of the SPCS, in which the carbon sheets enable the uniform distribution of sulfur, better ability to trap the soluble polysulfides and accommodate volume expansion/shrinkage of sulfur during repeated charge/discharge cycles. PMID:26842015

  18. Nafion coated sulfur-carbon electrode for high performance lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Tang, Qiwei; Shan, Zhongqiang; Wang, Li; Qin, Xue; Zhu, Kunlei; Tian, Jianhua; Liu, Xuesheng

    2014-01-01

    In this paper, a nafion coated electrode is prepared to improve the performance of lithium sulfur batteries. It is demonstrated from a series of measurements that the nafion layer is quite effective in reducing shuttle effect and enhancing the stability and the reversibility of the electrode. When measured under the rate of 0.2 C, the initial discharge capacity of the nafion coated electrode can reach 1084 mAh g-1, with a Columbic efficiency of about 100%. After 100 charge/discharge cycles, this electrode can also deliver a reversible capacity of as high as 879 mAh g-1. Significantly, the charge-transfer resistance of the electrode tends to be reducing after coated with an appropriate thickness of nafion film. The cation conductivity as well as anion inconductivity is considered to be the dominant factor for the superior electrochemical properties.

  19. High-Resolution Multiple Sulfur Isotope Studies of Martian Meteorites

    NASA Technical Reports Server (NTRS)

    Mojzsis, S. J.

    2000-01-01

    Sensitive, high resolution measurements of S-32, S-31, and S-34 in individual pyrite grains in martian meteorite ALH84001 by an in situ ion microprobe multi-collection technique reveal mass-independent anomalies in Delta.S-33 (Delta.S-33 = delta.S-33 - 0.516delta.S-34) in addition to the lowest 634S found in an extraterrestrial material. Low delta.S-34 values in two pyrite grains intimately associated with carbonate in ALH84001 can be explained by the sensitivity of sulfur to fractionations in the geologic environment. Anomalies in Delta.S-33 recorded in ALH84001 pyrites probably formed by gas-phase reactions in the early martian atmosphere (>4 Ga). The discovery of clearly resolvable Delta-S33 anomalies in 2 of 12 ALH84001 pyrites analyzed in their petrographic context in thin section, is considered strong evidence for crust-atmosphere exchange and the global cycling of volatile sulfur species on early Mars. These results corroborate previous measurements by Farquhar and co-workers who used a different technique that measures that bulk Delta.S-33 values of martian meteorites. These independent techniques, and their results, suggest that sulfur affected by mass-independent fractionation is common on Mars.

  20. Nitrogen-doped graphene/sulfur composite as cathode material for high capacity lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Wang, Xiwen; Zhang, Zhian; Qu, Yaohui; Lai, Yanqing; Li, Jie

    2014-06-01

    Two types of nitrogen-doped graphene sheets (NGS) synthesized by a facile hydrothermal method are used to immobilize sulfur via an in situ sulfur deposition route. The structure and composition of the prepared nitrogen doped graphene/sulfur (NGS/S) composites are confirmed with X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. Scanning electron microscope (SEM) and Transmission electron microscope (TEM) images shows the porous sulfur particles are well wrapped by NGS. Compared with graphene/sulfur (GS/S) composite, the NGS-1/S composite with high loading (80 wt%) of sulfur presents a remarkably higher reversible capacity (1356.8 mAh g-1 at 0.1 C) and long cycle stability (578.5 mAh g-1 remaining at 1 C up to 500 cycles). Pyridinic-N rich NGS-1/S exhibits a better electrochemical performance than pyrrolic-N enriched NGS-2/S. The improvement of electrochemical properties could be attributed to the chemical interaction between the nitrogen functionalities on the surface of NGS and polysulfide as well as the enhanced electronic conductivity of the carbon matrix.

  1. Sulfur-based composite cathode materials for high-energy rechargeable lithium batteries.

    PubMed

    Wang, Jiulin; He, Yu-Shi; Yang, Jun

    2015-01-21

    There is currently an urgent demand for highly efficient energy storage and conversion systems. Due to its high theoretical energy density, low cost, and environmental compatibility, the lithium sulfur (Li-S) battery has become a typical representative of the next generation of electrochemical power sources. Various approaches have been explored to design and prepare sulfur cathode materials to enhance their electrochemical performance. This Research News article summarizes and compares different sulfur materials for Li-S batteries and particularly focuses on the fine structures, electrochemical performance, and electrode reaction mechanisms of pyrolyzed polyacrylo-nitrile sulfur (pPAN@S) and microporous-carbon/small-sulfur composite materials. PMID:25256595

  2. Process for removing sulfur from sulfur-containing gases: high calcium fly-ash

    DOEpatents

    Rochelle, Gary T.; Chang, John C. S.

    1991-01-01

    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.

  3. Integrated Process Configuration for High-Temperature Sulfur Mitigation during Biomass Conversion via Indirect Gasification

    SciTech Connect

    Dutta. A.; Cheah, S.; Bain, R.; Feik, C.; Magrini-Bair, K.; Phillips, S.

    2012-06-20

    Sulfur present in biomass often causes catalyst deactivation during downstream operations after gasification. Early removal of sulfur from the syngas stream post-gasification is possible via process rearrangements and can be beneficial for maintaining a low-sulfur environment for all downstream operations. High-temperature sulfur sorbents have superior performance and capacity under drier syngas conditions. The reconfigured process discussed in this paper is comprised of indirect biomass gasification using dry recycled gas from downstream operations, which produces a drier syngas stream and, consequently, more-efficient sulfur removal at high temperatures using regenerable sorbents. A combination of experimental results from NREL's fluidizable Ni-based reforming catalyst, fluidizable Mn-based sulfur sorbent, and process modeling information show that using a coupled process of dry gasification with high-temperature sulfur removal can improve the performance of Ni-based reforming catalysts significantly.

  4. Aspergillus flavus Conidia-derived Carbon/Sulfur Composite as a Cathode Material for High Performance Lithium–Sulfur Battery

    PubMed Central

    Xu, Maowen; Jia, Min; Mao, Cuiping; Liu, Sangui; Bao, Shujuan; Jiang, Jian; Liu, Yang; Lu, Zhisong

    2016-01-01

    A novel approach was developed to prepare porous carbon materials with an extremely high surface area of 2459.6 m2g−1 by using Aspergillus flavus conidia as precursors. The porous carbon serves as a superior cathode material to anchor sulfur due to its uniform and tortuous morphology, enabling high capacity and good cycle lifetime in lithium sulfur-batteries. Under a current rate of 0.2 C, the carbon-sulfur composites with 56.7 wt% sulfur loading deliver an initial capacity of 1625 mAh g−1, which is almost equal to the theoretical capacity of sulfur. The good performance may be ascribed to excellent electronic networks constructed by the high-surface-area carbon species. Moreover, the semi-closed architecture of derived carbons can effectively retard the polysulfides dissolution during charge/discharge, resulting in a capacity of 940 mAh g−1 after 120 charge/discharge cycles. PMID:26732547

  5. Aspergillus flavus Conidia-derived Carbon/Sulfur Composite as a Cathode Material for High Performance Lithium-Sulfur Battery

    NASA Astrophysics Data System (ADS)

    Xu, Maowen; Jia, Min; Mao, Cuiping; Liu, Sangui; Bao, Shujuan; Jiang, Jian; Liu, Yang; Lu, Zhisong

    2016-01-01

    A novel approach was developed to prepare porous carbon materials with an extremely high surface area of 2459.6 m2g-1 by using Aspergillus flavus conidia as precursors. The porous carbon serves as a superior cathode material to anchor sulfur due to its uniform and tortuous morphology, enabling high capacity and good cycle lifetime in lithium sulfur-batteries. Under a current rate of 0.2 C, the carbon-sulfur composites with 56.7 wt% sulfur loading deliver an initial capacity of 1625 mAh g-1, which is almost equal to the theoretical capacity of sulfur. The good performance may be ascribed to excellent electronic networks constructed by the high-surface-area carbon species. Moreover, the semi-closed architecture of derived carbons can effectively retard the polysulfides dissolution during charge/discharge, resulting in a capacity of 940 mAh g-1 after 120 charge/discharge cycles.

  6. Efficient Activation of High-Loading Sulfur by Small CNTs Confined Inside a Large CNT for High-Capacity and High-Rate Lithium-Sulfur Batteries.

    PubMed

    Jin, Feiying; Xiao, Suo; Lu, Lijie; Wang, Yong

    2016-01-13

    Sulfur with a high specific capacity of 1673 mAh g(-1) is yet to be used as commercial cathode for lithium batteries because of its low utilization rate and poor cycle stability. In this work, a tube-in-tube carbon structure is demonstrated to relieve the critical problems with sulfur cathode: poor electrical conductivity, dissolution of lithium polysulfides, and large volume change during cycling. A number of small carbon nanotubes (∼20 nm in diameter) and a high loading amount of 85.2 wt % sulfur are both filled completely inside a large amorphous carbon nanotube (∼200 nm in diameter). Owing to the presence of these electrically conductive, highly flexible and structurally robust small CNTs and a large CNT overlayer, sulfur material exhibits a high utilization rate and delivers a large discharge capacity of 1633 mAh g(-1) (based on the mass of sulfur) at 0.1 C, approaching its theoretical capacity (1673 mAh g(-1)). The obtained S-CNTs@CNT electrode demonstrates superior high-rate cycling performances. Large discharge capacities of ∼1146, 1121, and 954 mAh g(-1) are observed after 150 cycles at large current rates of 1, 2, and 5 C, respectively. PMID:26675744

  7. Highly selective and sensitive response of 30.5 % of sprayed molybdenum trioxide (MoO3) nanobelts for nitrogen dioxide (NO2) gas detection.

    PubMed

    Mane, A A; Suryawanshi, M P; Kim, J H; Moholkar, A V

    2016-12-01

    The molybdenum trioxide (MoO3) thin films have been successfully deposited onto the glass substrates using chemical spray pyrolysis (CSP) deposition technique at various substrate temperatures ranging from 300°C to 450°C with an interval of 50°C. The effect of substrate temperature on the structural, morphological, optical and gas sensing properties of MoO3 thin films has been thoroughly investigated. X-ray diffraction analysis reveals that all the films have an orthorhombic crystal structure and are polycrystalline in nature. FE-SEM micrographs depict the formation of nanobelts-like morphology. AFM study reveals that the RMS surface roughness of MoO3 thin films increases from 8.6nm to 12nm with increase in substrate temperature from 300°C to 400°C and then decreases to 11.5nm for substrate temperature of 450°C. Optical results show that the band gap of MoO3 thin films decreases from 3.92eV to 3.44eV. The selectivity studies show that the gas response of various gases varies as NH3highly selective and sensitive for detection of NO2 gas in comparison with other gases. The maximum response of 30.5 % is obtained towards 100ppm NO2 gas concentration at an operating temperature of 200°C with response and recovery times of 20s and 160s, respectively. Finally, NO2 gas sensing mechanism model based on the chemisorption process is discussed. PMID:27552430

  8. High sulfur related thiamine deficiency in cattle: A field study

    PubMed Central

    Gooneratne, S. Ravi; Olkowski, Andrzej A.; Klemmer, Robert G.; Kessler, Gerald A.; Christensen, David A.

    1989-01-01

    Following development of polioencephalomalacia in one of 105 cattle in a farm in southeastern Saskatchewan, a study was initiated to monitor thiamine (B1) and copper (Cu) status, and to evaluate interactive nutritional factors which may have been responsible for this occurrence. It was evident that a combination of high sulfur (S) and low Cu intake was responsible for the depletion of blood B1 and plasma Cu. Supplementation with trace minerals alone resulted in a significant (p<0.05) improvement in both B1 and Cu status of the herd. We recommend that herds exposed to high intakes of S be supplemented with Cu up to 50 mg/kg feed dry matter to alleviate potential deficiencies of B1 and Cu. ImagesFigure 1.Figure 2. PMID:17423233

  9. Nickel Hydroxide-Modified Sulfur/Carbon Composite as a High-Performance Cathode Material for Lithium Sulfur Battery.

    PubMed

    Niu, Xiao-Qing; Wang, Xiu-Li; Xie, Dong; Wang, Dong-Huang; Zhang, Yi-Di; Li, Yi; Yu, Ting; Tu, Jiang-Ping

    2015-08-01

    Tailored sulfur cathode is vital for the development of a high performance lithium-sulfur (Li-S) battery. A surface modification on the sulfur/carbon composite would be an efficient strategy to enhance the cycling stability. Herein, we report a nickel hydroxide-modified sulfur/conductive carbon black composite (Ni(OH)2@S/CCB) as the cathode material for the Li-S battery through the thermal treatment and chemical precipitation method. In this composite, the sublimed sulfur is stored in the CCB, followed by a surface modification of Ni(OH)2 nanoparticles with size of 1-2 nm. As a cathode for the Li-S battery, the as-prepared Ni(OH)2@S/CCB electrode exhibits better cycle stability and higher rate discharge capacity, compared with the bare S/CCB electrode. The improved performance is largely due to the introduction of Ni(OH)2 surface modification, which can effectively suppress the "shuttle effect" of polysulfides, resulting in enhanced cycling life and higher capacity. PMID:26158375

  10. Domestic utilization of high sulfur coals: Trends and prospects

    SciTech Connect

    Bhagwat, S.

    1987-11-01

    Assuming that the current relative productivity and cost competitiveness of coal producing states will not change significantly by 1994, this paper makes two projections of coal production in the selected states. In scenario I, the current clean air regulations are assumed to apply until 1994, and coal production in the selected states is projected to increase by about 6% in 1994 compared to 1984. In scenario II, it is assumed that acid rain legislation will be implemented, which will adversely affect the markets for high sulfur coals. Coal production in the selected states under this scenario is projected to decline about 10% between 1984 and 1994, jeopardizing up to 13,000 mining jobs. The author concludes that better coal quality and greater cost competitiveness are both essential to stem the market losses and to regain strength.

  11. High performance Li-ion sulfur batteries enabled by intercalation chemistry.

    PubMed

    Lv, Dongping; Yan, Pengfei; Shao, Yuyan; Li, Qiuyan; Ferrara, Seth; Pan, Huilin; Graff, Gordon L; Polzin, Bryant; Wang, Chongmin; Zhang, Ji-Guang; Liu, Jun; Xiao, Jie

    2015-09-11

    The unstable interface of lithium metal in high energy density Li sulfur (Li-S) batteries raises concerns of poor cycling, low efficiency and safety issues, which may be addressed by using intercalation types of anode. Herein, a new prototype of Li-ion sulfur battery with high performance has been demonstrated by coupling a graphite anode with a sulfur cathode (2 mA h cm(-2)) after successfully addressing the interface issue of graphite in an ether based electrolyte. PMID:26214797

  12. High performance Li-ion sulfur batteries enabled by intercalation chemistry.

    PubMed

    Lv, Dongping; Yan, Pengfei; Shao, Yuyan; Li, Qiuyan; Ferrara, Seth; Pan, Huilin; Graff, Gordon L; Polzin, Bryant; Wang, Chongmin; Zhang, Ji-Guang; Liu, Jun; Xiao, Jie

    2015-09-11

    The unstable interface of lithium metal in high energy density Li sulfur (Li-S) batteries raises concerns of poor cycling, low efficiency and safety issues, which may be addressed by using intercalation types of anode. Herein, a new prototype of Li-ion sulfur battery with high performance has been demonstrated by coupling a graphite anode with a sulfur cathode (2 mA h cm(-2)) after successfully addressing the interface issue of graphite in an ether based electrolyte.

  13. New infrared transmitting material via inverse vulcanization of elemental sulfur to prepare high refractive index polymers.

    PubMed

    Griebel, Jared J; Namnabat, Soha; Kim, Eui Tae; Himmelhuber, Roland; Moronta, Dominic H; Chung, Woo Jin; Simmonds, Adam G; Kim, Kyung-Jo; van der Laan, John; Nguyen, Ngoc A; Dereniak, Eustace L; Mackay, Michael E; Char, Kookheon; Glass, Richard S; Norwood, Robert A; Pyun, Jeffrey

    2014-05-21

    Polymers for IR imaging: The preparation of high refractive index polymers (n = 1.75 to 1.86) via the inverse vulcanization of elemental sulfur is reported. High quality imaging in the near (1.5 μm) and mid-IR (3-5 μm) regions using high refractive index polymeric lenses from these sulfur materials was demonstrated.

  14. Pressure and high-Tc superconductivity in sulfur hydrides

    PubMed Central

    Gor’kov, Lev P.; Kresin, Vladimir Z.

    2016-01-01

    The paper discusses fundamentals of record-TC superconductivity discovered under high pressure in sulfur hydride. The rapid increase of TC with pressure in the vicinity of Pcr ≈ 123GPa is interpreted as the fingerprint of a first-order structural transition. Based on the cubic symmetry of the high-TC phase, it is argued that the lower-TC phase has a different periodicity, possibly related to an instability with a commensurate structural vector. In addition to the acoustic branches, the phonon spectrum of H3S contains hydrogen modes with much higher frequencies. Because of the complex spectrum, usual methods of calculating TC are here inapplicable. A modified approach is formulated and shown to provide realistic values for TC and to determine the relative contributions of optical and acoustic branches. The isotope effect (change of TC upon Deuterium for Hydrogen substitution) originates from high frequency phonons and differs in the two phases. The decrease of TC following its maximum in the high-TC phase is a sign of intermixing with pairing at hole-like pockets which arise in the energy spectrum of the cubic phase at the structural transition. On-pockets pairing leads to the appearance of a second gap and is remarkable for its non-adiabatic regime: hydrogen mode frequencies are comparable to the Fermi energy. PMID:27167334

  15. Pressure and high-Tc superconductivity in sulfur hydrides

    NASA Astrophysics Data System (ADS)

    Gor’Kov, Lev P.; Kresin, Vladimir Z.

    2016-05-01

    The paper discusses fundamentals of record-TC superconductivity discovered under high pressure in sulfur hydride. The rapid increase of TC with pressure in the vicinity of Pcr ≈ 123GPa is interpreted as the fingerprint of a first-order structural transition. Based on the cubic symmetry of the high-TC phase, it is argued that the lower-TC phase has a different periodicity, possibly related to an instability with a commensurate structural vector. In addition to the acoustic branches, the phonon spectrum of H3S contains hydrogen modes with much higher frequencies. Because of the complex spectrum, usual methods of calculating TC are here inapplicable. A modified approach is formulated and shown to provide realistic values for TC and to determine the relative contributions of optical and acoustic branches. The isotope effect (change of TC upon Deuterium for Hydrogen substitution) originates from high frequency phonons and differs in the two phases. The decrease of TC following its maximum in the high-TC phase is a sign of intermixing with pairing at hole-like pockets which arise in the energy spectrum of the cubic phase at the structural transition. On-pockets pairing leads to the appearance of a second gap and is remarkable for its non-adiabatic regime: hydrogen mode frequencies are comparable to the Fermi energy.

  16. The solubility of sulfur in high-TiO2 mare basalts

    NASA Technical Reports Server (NTRS)

    Danckwerth, P. A.; Hess, P. C.; Rutherford, M. J.

    1979-01-01

    The present paper deals with an experimental investigation of the solubility of sulfur of the high-TiO2 mare basalt 74275 at 1 atm, 1250 C. The data indicate that at saturation, 74275 is capable of dissolving 3400 ppm sulfur at 10 to 15 degrees below its liquidus. The analyzed samples of 74275 show sulfur contents of 1650 ppm S, which indicates that 74275 was 50% undersaturated at the time of eruption.

  17. Sepiolite-sulfur as a high-capacity, high-rate performance, and low-cost cathode material for lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Pan, Junan; Wu, Cheng; Cheng, Juanjuan; Pan, Yong; Ma, Zengsheng; Xie, Shuhong; Li, Jiangyu

    2015-10-01

    Lithium-sulfur batteries have the theoretical energy density of up to 2600 Wh/kg, though its commercialization is limited by high material cost and poor cyclic performance. In this work, we show that sepiolite-sulfur is a high-capacity, high-rate performance, and low-cost cathode material for lithium-sulfur batteries. Sepiolite is a porous mineral with specific structure, outstanding physical and chemical adsorption characteristics, and excellent ion exchange capability, making it an ideal matrix material for lithium-sulfur batteries. It is shown that the first specific discharge capacity of sepiolite-sulfur cathode is about 1436 mAh g-1 at 0.2 C current rate, and it remains as high as 901 mAh g-1 after 300 cycles. Under 1 C current density, the first discharge capacity is 1206 mAh g-1, and maintains a high value of 601 mAh g-1 after 500 cycles. The raw materials are abundant and low cost, and the manufacturing process is simple and scalable, making it promising for the commercialization of lithium-sulfur batteries.

  18. High Performance All-Solid-State Flexible Micro-Pseudocapacitor Based on Hierarchically Nanostructured Tungsten Trioxide Composite.

    PubMed

    Huang, Xuezhen; Liu, Hewei; Zhang, Xi; Jiang, Hongrui

    2015-12-23

    Microsupercapacitors (MSCs) are promising energy storage devices to power miniaturized portable electronics and microelectromechanical systems. With the increasing attention on all-solid-state flexible supercapacitors, new strategies for high-performance flexible MSCs are highly desired. Here, we demonstrate all-solid-state, flexible micropseudocapacitors via direct laser patterning on crack-free, flexible WO3/polyvinylidene fluoride (PVDF)/multiwalled carbon nanotubes (MWCNTs) composites containing high levels of porous hierarchically structured WO3 nanomaterials (up to 50 wt %) and limited binder (PVDF, <25 wt %). The work leads to an areal capacitance of 62.4 mF·cm(-2) and a volumetric capacitance of 10.4 F·cm(-3), exceeding that of graphene based flexible MSCs by a factor of 26 and 3, respectively. As a noncarbon based flexible MSC, hierarchically nanostructured WO3 in the narrow finger electrode is essential to such enhancement in energy density due to its pseudocapacitive property. The effects of WO3/PVDF/MWCNTs composite composition and the dimensions of interdigital structure on the performance of the flexible MSCs are investigated. PMID:26618406

  19. High Performance All-Solid-State Flexible Micro-Pseudocapacitor Based on Hierarchically Nanostructured Tungsten Trioxide Composite.

    PubMed

    Huang, Xuezhen; Liu, Hewei; Zhang, Xi; Jiang, Hongrui

    2015-12-23

    Microsupercapacitors (MSCs) are promising energy storage devices to power miniaturized portable electronics and microelectromechanical systems. With the increasing attention on all-solid-state flexible supercapacitors, new strategies for high-performance flexible MSCs are highly desired. Here, we demonstrate all-solid-state, flexible micropseudocapacitors via direct laser patterning on crack-free, flexible WO3/polyvinylidene fluoride (PVDF)/multiwalled carbon nanotubes (MWCNTs) composites containing high levels of porous hierarchically structured WO3 nanomaterials (up to 50 wt %) and limited binder (PVDF, <25 wt %). The work leads to an areal capacitance of 62.4 mF·cm(-2) and a volumetric capacitance of 10.4 F·cm(-3), exceeding that of graphene based flexible MSCs by a factor of 26 and 3, respectively. As a noncarbon based flexible MSC, hierarchically nanostructured WO3 in the narrow finger electrode is essential to such enhancement in energy density due to its pseudocapacitive property. The effects of WO3/PVDF/MWCNTs composite composition and the dimensions of interdigital structure on the performance of the flexible MSCs are investigated.

  20. Sodium-sulfur cells with high conductivity glass electrolytes

    SciTech Connect

    Nelson, P.A.; Bloom, I.; Bradley, J.; Roche, M.F.

    1985-01-01

    A study is under way to develop glasses in the soda-alumina-zirconia-silica system that have high conductivity for sodium ions. Sodium-conductivity and corrosion experiments indicate that the target resistivity of 100 ohm-cm at 300/sup 0/C can be achieved for glasses having satisfactory corrosion resistance for use in sodium-sulfur cells. The low resistivity makes possible a unique approach to cell design. Cells of 150 A-hr capacity were designed having 6-mm dia electrolytes and are expected to achieve a specific energy of up to 270 W-hr/kg. Others having 1.5-mm dia electrolytes are expected to attain a specific power of up to 2 or 3 kW/kg. Excellent heat removal can be provided for high-specific-power cells by short metallic paths from the center of the cell to the cooled cell wall. Reliability of the cell may be achieved by: (1) use of a protective tube around each electrolyte tube to protect against failure propagation and (2) the provision for automatic disconnection of a failed element by burnout of its current collector wire.

  1. Sodium-sulfur cells with high conductivity glass electrolytes

    NASA Astrophysics Data System (ADS)

    Nelson, P. A.; Bloom, I.; Bradley, J.; Roche, M. F.

    1985-05-01

    A study is under way to develop glasses in the soda-alumina-zirconia-silica system that have high conductivity for sodium ions. Sodium-conductivity and corrosion experiments indicate that the target resistivity of 100 ohm-cm at 300(0)C can be achieved for glasses having satisfactory corrosion resistance for use in sodium-sulfur cells. The low resistivity makes possible a unique approach to cell design. Cells of 150 A-hr capacity were designed having 6-mm dia electrolytes and are expected to achieve a specific energy of up to 270 W-hr/kg. Others having 1.5-mm dia electrolytes are expected to attain a specific power of up to 2 or 3 kW/kg. Excellent heat removal can be provided for high-specific-power cells by short metallic paths from the center of the cell to the cooled cell wall. Reliability of the cell may be achieved by: (1) use of a protective tube around each electrolyte tube to protect against failure propagation, and (2) the provision for automatic disconnection of a failed element by burnout of its current collector wire.

  2. Two-reactor, high-recovery sulfur plant and process

    SciTech Connect

    Reed, R.L.; Palm, J.W.

    1989-04-18

    This patent describes a process for the recovery of sulfur wherein an acid gas feedstream comprising hydrogen sulfide is processed for the recovery of sulfur in a Claus process sulfur recovery plant. The process consists of: (a) passing the acid gas feedstream successively through the thermal reaction zone, the first position Claus catalytic reaction zone, and the second position Claus catalytic reaction zone for the recovery of sulfur; (b) preconditioning the first position Claus catalytic reaction zone by introducing thereinto a cold stream having an inlet temperature effective for condensing sulfur on at least a portion of the catalyst and passing the resulting stream through a remaining substantial portion of the catalyst, the cold stream thus used for preconditioning being produced by cooling acid gas feedstream effluent from the thermal reaction zone to the first position catalytic reaction zone to the temperature; and (c) switching the thus preconditioned Claus catalytic reaction zone in the first position into the second position and continuing cooling the thus preconditioned freshly regenerated reactor in the second position concurrently with forming and depositing sulfur on catalyst therein, and switching the Claus catalytic reaction zone in the second position into the first position and continuing the process according to (a), (b), and (c).

  3. Sulfur-graphene nanostructured cathodes via ball-milling for high-performance lithium-sulfur batteries.

    PubMed

    Xu, Jiantie; Shui, Jianglan; Wang, Jianli; Wang, Min; Liu, Hua-Kun; Dou, Shi Xue; Jeon, In-Yup; Seo, Jeong-Min; Baek, Jong-Beom; Dai, Liming

    2014-10-28

    Although much progress has been made to develop high-performance lithium-sulfur batteries (LSBs), the reported physical or chemical routes to sulfur cathode materials are often multistep/complex and even involve environmentally hazardous reagents, and hence are infeasible for mass production. Here, we report a simple ball-milling technique to combine both the physical and chemical routes into a one-step process for low-cost, scalable, and eco-friendly production of graphene nanoplatelets (GnPs) edge-functionalized with sulfur (S-GnPs) as highly efficient LSB cathode materials of practical significance. LSBs based on the S-GnP cathode materials, produced by ball-milling 70 wt % sulfur and 30 wt % graphite, delivered a high initial reversible capacity of 1265.3 mAh g(-1) at 0.1 C in the voltage range of 1.5-3.0 V with an excellent rate capability, followed by a high reversible capacity of 966.1 mAh g(-1) at 2 C with a low capacity decay rate of 0.099% per cycle over 500 cycles, outperformed the current state-of-the-art cathode materials for LSBs. The observed excellent electrochemical performance can be attributed to a 3D "sandwich-like" structure of S-GnPs with an enhanced ionic conductivity and lithium insertion/extraction capacity during the discharge-charge process. Furthermore, a low-cost porous carbon paper pyrolyzed from common filter paper was inserted between the 0.7S-0.3GnP electrode and porous polypropylene film separator to reduce/eliminate the dissolution of physically adsorbed polysulfide into the electrolyte and subsequent cross-deposition on the anode, leading to further improved capacity and cycling stability.

  4. Sulfur-graphene nanostructured cathodes via ball-milling for high-performance lithium-sulfur batteries.

    PubMed

    Xu, Jiantie; Shui, Jianglan; Wang, Jianli; Wang, Min; Liu, Hua-Kun; Dou, Shi Xue; Jeon, In-Yup; Seo, Jeong-Min; Baek, Jong-Beom; Dai, Liming

    2014-10-28

    Although much progress has been made to develop high-performance lithium-sulfur batteries (LSBs), the reported physical or chemical routes to sulfur cathode materials are often multistep/complex and even involve environmentally hazardous reagents, and hence are infeasible for mass production. Here, we report a simple ball-milling technique to combine both the physical and chemical routes into a one-step process for low-cost, scalable, and eco-friendly production of graphene nanoplatelets (GnPs) edge-functionalized with sulfur (S-GnPs) as highly efficient LSB cathode materials of practical significance. LSBs based on the S-GnP cathode materials, produced by ball-milling 70 wt % sulfur and 30 wt % graphite, delivered a high initial reversible capacity of 1265.3 mAh g(-1) at 0.1 C in the voltage range of 1.5-3.0 V with an excellent rate capability, followed by a high reversible capacity of 966.1 mAh g(-1) at 2 C with a low capacity decay rate of 0.099% per cycle over 500 cycles, outperformed the current state-of-the-art cathode materials for LSBs. The observed excellent electrochemical performance can be attributed to a 3D "sandwich-like" structure of S-GnPs with an enhanced ionic conductivity and lithium insertion/extraction capacity during the discharge-charge process. Furthermore, a low-cost porous carbon paper pyrolyzed from common filter paper was inserted between the 0.7S-0.3GnP electrode and porous polypropylene film separator to reduce/eliminate the dissolution of physically adsorbed polysulfide into the electrolyte and subsequent cross-deposition on the anode, leading to further improved capacity and cycling stability. PMID:25290080

  5. Arsenic Trioxide-Induced Mandibular Osteomyelitis.

    PubMed

    Lu, Pei-Chen; Wu, Ju-Hui; Chen, Chun-Ming; Du, Je-Kang

    2015-09-01

    Previously, arsenic was a popular devitalizing agent used to necrotize inflamed dental pulp to lower the pulp sensitivity owing to the unavailability of appropriate anesthesia. However, leakage from the apical foramen, lateral or accessory canals, or cracks in the tooth is common. This can be dangerous because of the reportedly high toxic effects of arsenic in both hard and soft tissues, leading to gingival and osseous necrosis and, consequently, osteomyelitis. Therefore, arsenic can prove fatal for both bones and teeth and is no longer used. We encountered a case involving a 50-year-old man who had developed mandibular osteomyelitis with lower lip paresthesia caused by arsenic trioxide used during endodontic treatment. The patient was treated with appropriate antibiotics, adjunctive hyperbaric oxygen therapy, and adequate surgical debridement. Hyperbaric oxygen therapy can induce neovascularization in necrosed tissues and improve bone and soft tissue healing. At a 4-year follow-up visit, bone healing was observed, with restoration of periodontal health, although the paresthesia had persisted. We describe this case, present a review of the relevant published data, and discuss the possible causes, diagnosis, treatment, and follow-up protocol of mandibular osteomyelitis caused by arsenic trioxide. PMID:25896568

  6. High-temperature sorbent method for removal of sulfur containing gases from gaseous mixtures

    DOEpatents

    Young, J.E.; Jalan, V.M.

    1984-06-19

    A copper oxide-zinc oxide mixture is used as a sorbent for removing hydrogen sulfide and other sulfur containing gases at high temperatures from a gaseous fuel mixture. This high-temperature sorbent is especially useful for preparing fuel gases for high temperature fuel cells. The copper oxide is initially reduced in a preconditioning step to elemental copper and is present in a highly dispersed state throughout the zinc oxide which serves as a support as well as adding to the sulfur sorption capacity. The spent sorbent is regenerated by high-temperature treatment with an air fuel, air steam mixture followed by hydrogen reduction to remove and recover the sulfur.

  7. High-temperature sorbent method for removal of sulfur containing gases from gaseous mixtures

    DOEpatents

    Young, John E.; Jalan, Vinod M.

    1984-01-01

    A copper oxide-zinc oxide mixture is used as a sorbent for removing hydrogen sulfide and other sulfur containing gases at high temperatures from a gaseous fuel mixture. This high-temperature sorbent is especially useful for preparing fuel gases for high temperature fuel cells. The copper oxide is initially reduced in a preconditioning step to elemental copper and is present in a highly dispersed state throughout the zinc oxide which serves as a support as well as adding to the sulfur sorption capacity. The spent sorbent is regenerated by high-temperature treatment with an air fuel, air steam mixture followed by hydrogen reduction to remove and recover the sulfur.

  8. High-temperature sorbent method for removal of sulfur-containing gases from gaseous mixtures

    DOEpatents

    Young, J.E.; Jalan, V.M.

    1982-07-07

    A copper oxide-zinc oxide mixture is used as a sorbent for removing hydrogen sulfide and other sulfur containing gases at high temperatures from a gaseous fuel mixture. This high-temperature sorbent is especially useful for preparing fuel gases for high temperature fuel cells. The copper oxide is initially reduced in a preconditioning step to elemental copper and is present in a highly dispersed state throughout the zinc oxide which serves as a support as well as adding to the sulfur sorbtion capacity. The spent sorbent is regenerated by high-temperature treatment with an air fuel, air steam mixture followed by hydrogen reduction to remove and recover the sulfur.

  9. Corrosion-resistant coatings for high-temperature high-sulfur activity applications

    SciTech Connect

    Selman, J.R. . Dept. of Chemical Engineering)

    1990-06-01

    The research described in this report is intended to assist in developing the technology for the production of molybdenum, molybdenum carbide and titanium nitride coatings. These coatings have the potential to serve as an alternative to present methods of protecting the metal parts, at positive potential, of high-temperature sulfur or sulfide batteries (e.g., chromizing). This research project was prompted by the observation that only very few materials are corrosion resistant in a high-temperature high-sulfur-activity environment containing polysulfide or FeS{sub 2}. Among these materials only molybdenum has really satisfactory corrosion resistance. In LiCl-KCl eutectic containing FeS{sub 2}, titanium nitride has also shown adequate corrosion resistance. In polysulfide melts chromium shows good corrosion resistance, and chromizing is presently used to protect the internal surface of the containers in the sodium-sulfur battery, as manufactured at Chloride Silent Power Ltd. It should be noted that the issue of an optimal coating for the sodium-sulfur battery container is somewhat clouded and may be resolved satisfactorily only when there is more information about the effect of very small amounts of dissolved metal, such as chromium or molybdenum, on the life of the sodium-beta-alumina electrolyte. Nevertheless, there is a clear incentive for exploring molybdenum, or molybdenum derivatives, and titanium nitride as alternative protecting materials. 8 refs., 11 figs.

  10. A long-life lithium ion sulfur battery exploiting high performance electrodes.

    PubMed

    Moreno, Noelia; Agostini, Marco; Caballero, Alvaro; Morales, Julián; Hassoun, Jusef

    2015-10-01

    A novel lithium ion sulfur battery is formed by coupling an activated ordered mesoporous carbon-sulfur (AOMC-S) cathode and a nanostructured tin-carbon anode. The lithium ion cell has improved reversibility, high energy content and excellent cycle life.

  11. Lithium-Sulfur Batteries: Development of High Energy Lithium-Sulfur Cells for Electric Vehicle Applications

    SciTech Connect

    2010-10-01

    BEEST Project: Sion Power is developing a lithium-sulfur (Li-S) battery, a potentially cost-effective alternative to the Li-Ion battery that could store 400% more energy per pound. All batteries have 3 key parts—a positive and negative electrode and an electrolyte—that exchange ions to store and release electricity. Using different materials for these components changes a battery’s chemistry and its ability to power a vehicle. Traditional Li-S batteries experience adverse reactions between the electrolyte and lithium-based negative electrode that ultimately limit the battery to less than 50 charge cycles. Sion Power will sandwich the lithium- and sulfur-based electrode films around a separator that protects the negative electrode and increases the number of charges the battery can complete in its lifetime. The design could eventually allow for a battery with 400% greater storage capacity per pound than Li-Ion batteries and the ability to complete more than 500 recharge cycles.

  12. Mildly reduced less defective graphene oxide/sulfur/carbon nanotube composite films for high-performance lithium-sulfur batteries.

    PubMed

    Li, Rui; Zhang, Miao; Li, Yingru; Chen, Ji; Yao, Bowen; Yu, Mingpeng; Shi, Gaoquan

    2016-04-28

    The microstructures and properties of the carbonaceous matrices in the cathodes of lithium-sulfur (Li-S) batteries have strong effects on their performances. We prepared a ternary composite cathode of mildly reduced less defective graphene oxide (mrLGO), sulfur, and carbon nanotubes (CNTs) by filtration for Li-S batteries. This battery showed a high initial specific capacity of 1219 mA h g(-1) at 0.2 C and a stable specific capacity of around 1000 mA h g(-1) after 200 cycles with a coulombic efficiency of 99%. Its excellent performance is mainly attributed to the good conductivity and residual oxygen containing groups of mrLGO, and the three-dimensional (3D) framework constructed using mrLGO sheets and CNTs. PMID:27049434

  13. Sulfur removal from high-sulfur Illinois coal by low-temperature perchloroethylene (PCE) extraction. Technical report, December 1, 1991--February 29, 1992

    SciTech Connect

    Chou, M.I.M; Lytle, J.M.; Ruch, R.R.; Kruse, C.W.; Chaven, C.; Hackley, K.C.; Hughes, R.E.; Harvey, R.D.; Frost, J.K.; Buchanan, D.H.; Stucki, J.W.; Huffman, G.; Huggins, F.E.

    1992-09-01

    A pre-combustion coal desulfurization process at 120{degree}C using perchloroethylene (PCE) to remove up to 70% of the organic sulfur has been developed by the Midwest Ore Processing Co. (MWOPC). However, this process has not yet proven to be as successful with Illinois coals as it has for Ohio and Indiana coals. In addition, the high levels of organic sulfur removals observed by the MWOPC may be due to certain errors involved in the ASTM data interpretation; this needs verification. For example, elemental sulfur extracted by the PCE may be derived from pyrite oxidation during coal preoxidation, but it may be interpreted as organic sulfur removed by the PCE using ASTM analysis. The purposes of this research are to independently confirm and possibly to improve the organic sulfur removal from Illinois coals with the PCE desulfurization process reported by the MWOPC and to verify the forms-of-sulfur determination using the ASTM method for the PCE process evaluation.

  14. Extraction, separation, and analysis of high sulfur coal. Final report

    SciTech Connect

    Olesik, S.V.; Pekay, L.A.; Larkins, W. Jr.

    1992-05-31

    The work described in this report studies the removal of sulfur by oxidative interaction of various cupric salts with coal and also considers the possibility of removing organic sulfur by the selective interaction of supercritical ethanol with the organic coal matrix. Either one of these methods could potentially be used to pretreat coals before burning. The primary purpose of these studies is to ascertain the nature of the chemical reactions occurring, the chemical composition of the resultant products, and information on possible reaction mechanisms. This information should allow prediction of reasonable reaction conditions for the removal of organosulfur compound from coal.

  15. Extraction, separation, and analysis of high sulfur coal

    SciTech Connect

    Olesik, S.V.; Pekay, L.A.; Larkins, W. Jr.

    1992-05-31

    The work described in this report studies the removal of sulfur by oxidative interaction of various cupric salts with coal and also considers the possibility of removing organic sulfur by the selective interaction of supercritical ethanol with the organic coal matrix. Either one of these methods could potentially be used to pretreat coals before burning. The primary purpose of these studies is to ascertain the nature of the chemical reactions occurring, the chemical composition of the resultant products, and information on possible reaction mechanisms. This information should allow prediction of reasonable reaction conditions for the removal of organosulfur compound from coal.

  16. Production of low-sulfur binder pitch from high-sulfur Illinois coals. Technical report, September 1--November 30, 1994

    SciTech Connect

    Knight, R.A.

    1994-12-31

    The objective of this project is to produce electrode binder pitch with sulfur content below 0.6 wt% from high-sulfur Illinois coal mild gasification liquids. In this project, two approaches to sulfur reduction are being explored in conjunction with thermocracking: (1) the use of conventionally cleaned coal with low ({approximately}1%) sulfur as a mild gasification feedstock, and (2) direct biodesulfurization of the liquids prior to thermocracking. In Case 1, the crude pitch is being produced by mild gasification of IBC-109 coal in an existing IGT bench-scale reactor, followed by distillation of the scrubbing solvent and light-to-middle oils to isolate the crude pitch. In Case 2, the crude pitch for biodesulfurization is the same material previously studied, which was obtained from Illinois No. 6 coal tests conducted in the IGT mild gasification PRU in 1990. Biodesulfurization is to be performed by contacting the pitch with Rhodococcus Rhodochrous either as live cultures or in the form of concentrated biocatalyst. Following preparation of the crude pitches, pitch upgrading experiments are to be conducted in a continuous flash thermocracker (FTC) constructed in previous ICCI-sponsored studies. The finished pitch is then characterized for physical and chemical properties (density, softening point, QI, TI, coking value, and elemental composition), and compared to typical specifications for binder pitches. This quarter, 45 kg of IBC-109 coal was obtained and sized to 40 x 80 mesh for mild gasification. Laboratory experiments were conducted to identify means of dispersing or emulsifying pitch in water to render is accessible to biocatalysts, and exploratory desulfurization tests on one-gram pitch samples were begun.

  17. High-Capacity Sulfur Dioxide Absorbents for Diesel Emissions Control

    SciTech Connect

    Li, Liyu; King, David L.

    2005-01-05

    High capacity sulfur dioxide absorbents based on manganese oxide octahedral molecular sieves (OMS) have been identified. These materials are based on MnO6 octahedra sharing faces and edges to form various tunnel structures (2x2, 2x3, 2x4, 3x3) differentiated by the number of octahedra on a side. The SO2 capacities of these materials, measured at 325 C with a feed containing 250 ppmv SO2 in air, are as high as 70wt% (wt/wt), remarkably higher than conventional metal oxide-based SO2 absorbents. Among the OMS materials the 2x2 member, cryptomelane, exhibits the highest capacity and adsorption rate. Its SO2 absorption behavior has been further characterized as a function of temperature, space velocity, and feed composition. The dominant pathway for SO2 absorption is through the oxidation of SO2 to SO3 by Mn4+ followed by SO3 reaction with Mn2+ to form MnSO4. Absorption can occur in the absence of gas phase oxygen, with a moderate loss in overall capacity. The inclusion of reducible gases NO and CO in the feed does not reduce SO2 capacity. The absorption capacity decreases at high space velocity and lower absorption temperature, indicating the important role of diffusion of sulfate from the surface to the bulk of the material in order to reach full capacity. A color change of cryptomelane from black to yellow-brown after SO2 absorption can be used as an indicator of absorption progress. Cryptomelane can be synthesized using MnSO4 as a reagent. Therefore, after full SO2 absorption the product MnSO4 can be re-used as raw material for a subsequent cryptomelane synthesis. Cryptomelane has a similarly high capacity toward SO3, therefore it can be used for removal of all SOx species generated from a variety of combustion sources. Cryptomelane may find application as a replaceable absorbent for the removal of SOx from diesel truck exhaust, protecting downstream emissions control devices such as particulate filters and NOx traps.

  18. New infrared transmitting material via inverse vulcanization of elemental sulfur to prepare high refractive index polymers.

    PubMed

    Griebel, Jared J; Namnabat, Soha; Kim, Eui Tae; Himmelhuber, Roland; Moronta, Dominic H; Chung, Woo Jin; Simmonds, Adam G; Kim, Kyung-Jo; van der Laan, John; Nguyen, Ngoc A; Dereniak, Eustace L; Mackay, Michael E; Char, Kookheon; Glass, Richard S; Norwood, Robert A; Pyun, Jeffrey

    2014-05-21

    Polymers for IR imaging: The preparation of high refractive index polymers (n = 1.75 to 1.86) via the inverse vulcanization of elemental sulfur is reported. High quality imaging in the near (1.5 μm) and mid-IR (3-5 μm) regions using high refractive index polymeric lenses from these sulfur materials was demonstrated. PMID:24659231

  19. Sulfur Embedded in a Mesoporous Carbon Nanotube Network as a Binder-Free Electrode for High-Performance Lithium-Sulfur Batteries.

    PubMed

    Sun, Li; Wang, Datao; Luo, Yufeng; Wang, Ke; Kong, Weibang; Wu, Yang; Zhang, Lina; Jiang, Kaili; Li, Qunqing; Zhang, Yihe; Wang, Jiaping; Fan, Shoushan

    2016-01-26

    Sulfur-porous carbon nanotube (S-PCNT) composites are proposed as cathode materials for advanced lithium-sulfur (Li-S) batteries. Abundant mesopores are introduced to superaligned carbon nanotubes (SACNTs) through controlled oxidation in air to obtain porous carbon nanotubes (PCNTs). Compared to original SACNTs, improved dispersive behavior, enhanced conductivity, and higher mechanical strength are demonstrated in PCNTs. Meanwhile, high flexibility and sufficient intertube interaction are preserved in PCNTs to support binder-free and flexible electrodes. Additionally, several attractive features, including high surface area and abundant adsorption points on tubes, are introduced, which allow high sulfur loading, provide dual protection to sulfur cathode materials, and consequently alleviate the capacity fade especially during slow charge/discharge processes. When used as cathodes for Li-S batteries, a high sulfur loading of 60 wt % is achieved, with excellent reversible capacities of 866 and 526 mAh g(-1) based on the weights of sulfur and electrode, respectively, after 100 cycles at a slow charge/discharge rate of 0.1C, revealing efficient suppression of polysulfide dissolution. Even with a high sulfur loading of 70 wt %, the S-PCNT composite maintains capacities of 760 and 528 mAh g(-1) based on the weights of sulfur and electrode, respectively, after 100 cycles at 0.1C, outperforming the current state-of-the-art sulfur cathodes. Improved high-rate capability is also delivered by the S-PCNT composites, revealing their potentials as high-performance carbon-sulfur composite cathodes for Li-S batteries.

  20. Polymorphism in two genes for B2 high sulfur proteins of wool.

    PubMed

    Rogers, G R; Hickford, J G; Bickerstaffe, R

    1994-12-01

    Variation in the nucleotide sequence of the B2 high-sulfur protein genes has not been reported previously. This paper reports 15 nucleotide substitutions in each of the genes for the B2A and B2C proteins and a length of polymorphism in the B2A gene which translates to the insertion/deletion of one 30-nucleotide repeat sequence. Evidence is presented for gene conversion occurring within the B2 high-sulfur multigene family. These DNA polymorphisms may account for some of the microheterogeneity observed in the B2 high-sulfur proteins and may also be useful genetic markers of the B2 high-sulfur protein gene loci for future use in analysing wool fibre characteristics.

  1. Durable polydopamine-coated porous sulfur core-shell cathode for high performance lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Deng, Yuanfu; Xu, Hui; Bai, Zhaowen; Huang, Baoling; Su, Jingyang; Chen, Guohua

    2015-12-01

    Lithium-sulfur batteries show fascinating potential for advanced energy system due to their high specific capacity, low-cost, and environmental benignity. However, their wide applications have been plagued by low coulombic efficiency, fast capacity fading and poor rate performance. Herein, a facile method for preparation of S@PDA (PDA = polydopamine) composites with core-shell structure and good electrochemical performance as well as the First-Principles calculations on the interactions of PDA and polysulfides are reported. Taking the advantages of the core-shell structure with porous sulfur core, the high mechanical flexibility of PDA for accommodating the volumetric variation during the discharge/charge processes, the good lithium ion conductivity and the strong chemical interactions between the nitrogen/oxygen atoms with lone electron pair and lithium polysulfides for alleviating their dissolution, the S@PDA composites exhibit high discharge capacities at different current densities (1048 and 869 mAh g-1 at 0.2 and 0.8 A g-1, respectively) and excellent capacity retention capability. A capacity decay as low as 0.021% per cycle and an average coulombic efficiency of 98.5% is observed over a long-term cycling of 890 cycles at 0.8 A g-1. The S@PDA electrode has great potential as a low-cost cathode in high energy Li-S batteries.

  2. Sulfur removal from high-sulfur Illinois coal by low-temperature perchloroethylene (PCE) extraction. Annual report, September 1, 1991--August 31, 1992

    SciTech Connect

    Chou, M.I.M.; Lytle, J.M.; Ruch, R.R.; Kruse, C.W.; Chaven, C.; Hackley, K.C.; Hughes, R.E.; Harvey, R.D.; Frost, J.K.; Buchanan, D.H.; Stucki, J.W.; Huffman, G.P.; Huggins, F.E.; Banerjee, D.D.

    1992-12-31

    The Midwest Ore Processing Co. (MWOPC) has reported a precombustion coal desulfurization process using perchloroethylene (PCE) at 120{degree}C to remove up to 70% of the organic sulfur. However, this process has not been proven to be as successful with Illinois coals as it has been for Ohio and Indiana coals. Also, the high levels of organic sulfur removals observed by the MWOPC may be due to certain errors involved in interpreting data from the American Society For Testing and Materials (ASTM) method for forms-of-sulfur analysis. The purposes of this research are to independently confirm and possibly to improve the organic sulfur removal from Illinois coals with the PCE desulfurization process and to verify the forms-of-sulfur determination using the ASTM method for evaluation of the PCE process. One problem that limits commercial application of the PCE process is the high chlorine content in the PCE-treated coals. Hence, an additional goal of this investigation is to develop a dechlorination procedure to remove excess PCE from the PCE-treated coal. MWOPC`s results have been repeated on our tests for the fresh IBC-104 coal. Oxidation of coals was found to affect subsequent PCE desulfurization. Elemental sulfur is more amenable than organic sulfur to removal by PCE. Ohio 5/6 coal appears to produce elemental sulfur more readily than Illinois coal during oxidation.

  3. Tribological behavior of near-frictionless carbon coatings in high- and low-sulfur diesel fuels.

    SciTech Connect

    Alzoubi, M. F.; Ajayi, O. O.; Eryilmaz, O. L.; Ozturk, O.; Erdemir, A.; Fenske, G.

    2000-01-19

    The sulfur content in diesel fuel has a significant effect on diesel engine emissions, which are currently subject to environmental regulations. It has been observed that engine particulate and gaseous emissions are directly proportional to fuel sulfur content. With the introduction of low-sulfur fuels, significant reductions in emissions are expected. The process of sulfur reduction in petroleum-based diesel fuels also reduces the lubricity of the fuel, resulting in premature failure of fuel injectors. Thus, another means of preventing injector failures is needed for engines operating with low-sulfur diesel fuels. In this study, the authors evaluated a near-frictionless carbon (NFC) coating (developed at Argonne National Laboratory) as a possible solution to the problems associated with fuel injector failures in low-lubricity fuels. Tribological tests were conducted with NFC-coated and uncoated H13 and 52100 steels lubricated with high- and low- sulfur diesel fuels in a high-frequency reciprocating test machine. The test results showed that the NFC coatings reduced wear rates by a factor of 10 over those of uncoated steel surfaces. In low-sulfur diesel fuel, the reduction in wear rate was even greater (i.e., by a factor of 12 compared to that of uncoated test pairs), indicating that the NFC coating holds promise as a potential solution to wear problems associated with the use of low-lubricity diesel fuels.

  4. New approaches for high energy density lithium-sulfur battery cathodes.

    PubMed

    Evers, Scott; Nazar, Linda F

    2013-05-21

    The goal of replacing combustion engines or reducing their use presents a daunting problem for society. Current lithium-ion technologies provide a stepping stone for this dramatic but inevitable change. However, the theoretical gravimetric capacity (∼300 mA h g(-1)) is too low to overcome the problems of limited range in electric vehicles, and their cost is too high to sustain the commercial viability of electrified transportation. Sulfur is the one of the most promising next generation cathode materials. Since the 1960s, researchers have studied sulfur as a cathode, but only recently have great strides been made in preparing viable composites that can be used commercially. Sulfur batteries implement inexpensive, earth-abundant elements at the cathode while offering up to a five-fold increase in energy density compared with present Li-ion batteries. Over the past few years, researchers have come closer to solving the challenges associated with the sulfur cathode. Using carbon or conducting polymers, researchers have wired up sulfur, an excellent insulator, successfully. These conductive hosts also function to encapsulate the active sulfur mass upon reduction/oxidation when highly soluble lithium polysulfides are formed. These soluble discharge products remain a crux of the Li-S cell and need to be contained in order to increase cycle life and capacity retention. The use of mesoporous carbons and tailored designs featuring porous carbon hollow spheres have led to highly stable discharge capacities greater than 900 mA h g(-1) over 100 cycles. In an attempt to fully limit polysulfide dissolution, methods that rely on coating carbon/sulfur composites with polymers have led to surprisingly stable capacities (∼90% of initial capacity retained). Additives will also play an important role in sulfur electrode design. For example, small fractions (> 3 wt%) of porous silica or titania effectively act as polysulfide reservoirs, decreasing their concentration in the

  5. Cleaning of China high sulfur coals by selective dispersion and flocculation

    SciTech Connect

    Wang Li; Liu Zechang; Liu Zhenxue

    1997-12-31

    A process for removing pyritic sulfur from high sulfur coals by selective dispersion and flocculation has been conceptually developed and tested in China. The tentative tests on China high sulfur coals have shown that this coal cleaning process can be very efficient in coal desulfurization, provided the process parameters are properly optimized. While acquiring high coal recovery, the total sulfur rejection with four kinds of coals normally falls in the range 57% to 71% by one-step reverse flocculation, and within the range 40% to 59% by one-step normal flocculation process. This cleaning process presents a promising approach for the removal of pyrite particles from coal fines suspensions. Most of the results presented in this paper are preliminary in nature, and further research is being carried out.

  6. Sulfur/graphitic hollow carbon sphere nano-composite as a cathode material for high-power lithium-sulfur battery.

    PubMed

    Shin, Eon Sung; Kim, Min-Seop; Cho, Won Il; Oh, Si Hyoung

    2013-08-03

    The intrinsic low conductivity of sulfur which leads to a low performance at a high current rate is one of the most limiting factors for the commercialization of lithium-sulfur battery. Here, we present an easy and convenient method to synthesize a mono-dispersed hollow carbon sphere with a thin graphitic wall which can be utilized as a support with a good electrical conductivity for the preparation of sulfur/carbon nano-composite cathode. The hollow carbon sphere was prepared from the pyrolysis of the homogenous mixture of the mono-dispersed spherical silica and Fe-phthalocyanine powder in elevated temperature. The composite cathode was manufactured by infiltrating sulfur melt into the inner side of the graphitic wall. The electrochemical cycling shows a capacity of 425 mAh g-1 at 3 C current rate which is more than five times larger than that for the sulfur/carbon black nano-composite prepared by simple ball milling.

  7. 3D coral-like nitrogen-sulfur co-doped carbon-sulfur composite for high performance lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Wu, Feng; Li, Jian; Tian, Yafen; Su, Yuefeng; Wang, Jing; Yang, Wen; Li, Ning; Chen, Shi; Bao, Liying

    2015-08-01

    3D coral-like, nitrogen and sulfur co-doped mesoporous carbon has been synthesized by a facile hydrothermal-nanocasting method to house sulfur for Li-S batteries. The primary doped species (pyridinic-N, pyrrolic-N, thiophenic-S and sulfonic-S) enable this carbon matrix to suppress the diffusion of polysulfides, while the interconnected mesoporous carbon network is favourable for rapid transport of both electrons and lithium ions. Based on the synergistic effect of N, S co-doping and the mesoporous conductive pathway, the as-fabricated C/S cathodes yield excellent cycling stability at a current rate of 4 C (1 C = 1675 mA g-1) with only 0.085% capacity decay per cycle for over 250 cycles and ultra-high rate capability (693 mAh g-1 at 10 C rate). These capabilities have rarely been reported before for Li-S batteries.

  8. 3D coral-like nitrogen-sulfur co-doped carbon-sulfur composite for high performance lithium-sulfur batteries

    PubMed Central

    Wu, Feng; Li, Jian; Tian, Yafen; Su, Yuefeng; Wang, Jing; Yang, Wen; Li, Ning; Chen, Shi; Bao, Liying

    2015-01-01

    3D coral-like, nitrogen and sulfur co-doped mesoporous carbon has been synthesized by a facile hydrothermal-nanocasting method to house sulfur for Li–S batteries. The primary doped species (pyridinic-N, pyrrolic-N, thiophenic-S and sulfonic-S) enable this carbon matrix to suppress the diffusion of polysulfides, while the interconnected mesoporous carbon network is favourable for rapid transport of both electrons and lithium ions. Based on the synergistic effect of N, S co-doping and the mesoporous conductive pathway, the as-fabricated C/S cathodes yield excellent cycling stability at a current rate of 4 C (1 C = 1675 mA g−1) with only 0.085% capacity decay per cycle for over 250 cycles and ultra-high rate capability (693 mAh g−1 at 10 C rate). These capabilities have rarely been reported before for Li-S batteries. PMID:26288961

  9. A high-energy room-temperature sodium-sulfur battery.

    PubMed

    Xin, Sen; Yin, Ya-Xia; Guo, Yu-Guo; Wan, Li-Jun

    2014-02-26

    Employing small sulfur molecules as the active cathode component for room-temperature Na-S batteries, reveals a novel mechanism that is verified for the batteries' electrochemistry. The sulfur cathode enables a complete two-electron reaction to form Na2 S, bringing a tripled specific capacity and an increased specific energy compared with traditional high-temperature Na-S batteries. At the same time, it offers better cycling stability endowing the batteries with a longer lifespan.

  10. Engineering of Hollow Core-Shell Interlinked Carbon Spheres for Highly Stable Lithium-Sulfur Batteries.

    PubMed

    Sun, Qiang; He, Bin; Zhang, Xiang-Qian; Lu, An-Hui

    2015-08-25

    We report engineered hollow core-shell interlinked carbon spheres that consist of a mesoporous shell, a hollow void, and an anchored carbon core and are expected to be ideal sulfur hosts for overcoming the shortage of Li-S batteries. The hollow core-shell interlinked carbon spheres were obtained through solution synthesis of polymer spheres followed by a pyrolysis process that occurred in the hermetical silica shell. During the pyrolysis, the polymer sphere was transformed into the carbon core and the carbonaceous volatiles were self-deposited on the silica shell due to the blocking effect of the hermetical silica shell. The gravitational force and the natural driving force of lowering the surface energy tend to interlink the carbon core and carbon/silica shell, resulting in a core-shell interlinked structure. After the SiO2 shell was etched, the mesoporous carbon shell was generated. When used as the sulfur host for Li-S batteries, such a hierarchical structure provides access to Li(+) ingress/egress for reactivity with the sulfur and, meanwhile, can overcome the limitations of low sulfur loading and a severe shuttle effect in solid carbon-supported sulfur cathodes. Transmission electron microscopy and scanning transmission electron microscopy images provide visible evidence that sulfur is well-encapsulated in the hollow void. Importantly, such anchored-core carbon nanostructures can simultaneously serve as a physical buffer and an electronically connecting matrix, which helps to realize the full potential of the active materials. Based on the many merits, carbon-sulfur cathodes show a high utilization of sulfur with a sulfur loading of 70 wt % and exhibit excellent cycling stability (i.e., 960 mA h g(-1) after 200 cycles at a current density of 0.5 C). PMID:26182333

  11. Engineering of Hollow Core-Shell Interlinked Carbon Spheres for Highly Stable Lithium-Sulfur Batteries.

    PubMed

    Sun, Qiang; He, Bin; Zhang, Xiang-Qian; Lu, An-Hui

    2015-08-25

    We report engineered hollow core-shell interlinked carbon spheres that consist of a mesoporous shell, a hollow void, and an anchored carbon core and are expected to be ideal sulfur hosts for overcoming the shortage of Li-S batteries. The hollow core-shell interlinked carbon spheres were obtained through solution synthesis of polymer spheres followed by a pyrolysis process that occurred in the hermetical silica shell. During the pyrolysis, the polymer sphere was transformed into the carbon core and the carbonaceous volatiles were self-deposited on the silica shell due to the blocking effect of the hermetical silica shell. The gravitational force and the natural driving force of lowering the surface energy tend to interlink the carbon core and carbon/silica shell, resulting in a core-shell interlinked structure. After the SiO2 shell was etched, the mesoporous carbon shell was generated. When used as the sulfur host for Li-S batteries, such a hierarchical structure provides access to Li(+) ingress/egress for reactivity with the sulfur and, meanwhile, can overcome the limitations of low sulfur loading and a severe shuttle effect in solid carbon-supported sulfur cathodes. Transmission electron microscopy and scanning transmission electron microscopy images provide visible evidence that sulfur is well-encapsulated in the hollow void. Importantly, such anchored-core carbon nanostructures can simultaneously serve as a physical buffer and an electronically connecting matrix, which helps to realize the full potential of the active materials. Based on the many merits, carbon-sulfur cathodes show a high utilization of sulfur with a sulfur loading of 70 wt % and exhibit excellent cycling stability (i.e., 960 mA h g(-1) after 200 cycles at a current density of 0.5 C).

  12. Recovery of high purity sulfuric acid from the waste acid in toluene nitration process by rectification.

    PubMed

    Song, Kai; Meng, Qingqiang; Shu, Fan; Ye, Zhengfang

    2013-01-01

    Waste sulfuric acid is a byproduct generated from numerous industrial chemical processes. It is essential to remove the impurities and recover the sulfuric acid from the waste acid. In this study the rectification method was introduced to recover high purity sulfuric acid from the waste acid generated in toluene nitration process by using rectification column. The waste acid quality before and after rectification were evaluated using UV-Vis spectroscopy, GC/MS, HPLC and other physical and chemical analysis. It was shown that five nitro aromatic compounds in the waste acid were substantially removed and high purity sulfuric acid was also recovered in the rectification process at the same time. The COD was removed by 94% and the chrominance was reduced from 1000° to 1°. The recovered sulfuric acid with the concentration reaching 98.2 wt% had a comparable quality with commercial sulfuric acid and could be recycled back into the toluene nitration process, which could avoid waste of resources and reduce the environmental impact and pollution.

  13. Sulfur-impregnated 3D hierarchical porous nitrogen-doped aligned carbon nanotubes as high-performance cathode for lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Deng, Weina; Hu, Aiping; Chen, Xiaohua; Zhang, Shiying; Tang, Qunli; Liu, Zheng; Fan, Binbin; Xiao, Kuikui

    2016-08-01

    A rational 3D hierarchical porous nitrogen-doped aligned carbon nanotubes (HPNACNTs) with well-directed 1D conductive electron paths is designed as scaffold to load sulfur. The HPNACNTs have abundant micropores, mesopores and macropores with a relatively high specific surface area and a large total pore volume. The sulfur-HPNACNTs composite is synthesized for lithium-sulfur batteries by a melt-diffusion of sulfur powders into HPNACNTs scaffolds. Electrochemical tests reveal that the sulfur-HPNACNTs (68.8 wt% sulfur) composite exhibits a high initial discharge capacity of 1340 mAh g-1 at 0.1 C and retains as high as 979 mAh g-1 at 0.2 C after 200 cycles. More importantly, it shows high reversible capacity at high rates (817 mAh g-1 at 5 C). Its enhanced electrochemical performance can be attributed to the excellent electrical conductivity of aligned carbon nanotubes, the synergetic effect of its hierarchical porosity and the restraint of the shuttle effect due to the SxLi … N interactions via the N lone-pair electron.

  14. Alternative motif toward high-quality wurtzite MnSe nanorods via subtle sulfur element doping.

    PubMed

    Zhou, Bo; Yang, Xinyi; Sui, Yongming; Xiao, Guanjun; Wei, Yingjin; Zou, Bo

    2016-04-28

    The manipulated synthesis of high-quality semiconductor nanocrystals (NCs) is of high significance with respect to the exploration of their properties and their corresponding applications. Nevertheless, the preparation of metastable-phase NCs still remains a great challenge due to their high kinetic barriers and harsh synthetic conditions. Herein, we demonstrated the fabrication of high-quality MnSe nanorods with a metastable wurtzite structure via a subtle sulfur-doping strategy. Based on the UV-vis absorption spectra, manganese polysulfide clusters were formed by mixing oleylamine-sulfur and oleylamine-manganese solutions at room temperature. The existence of manganese polysulfide clusters with polymeric sulfur structures makes the system more reactive, inducing fast wurtzite-phase nucleation. This can overcome the natural kinetic barrier of wurtzite MnSe and lead to subsequent growth of targeted NCs. On the other hand, no sulfur doping would produce MnSe NCs in a thermodynamically favorable rock-salt phase. As expected, different doping contents and sulfur sources also resulted in the formation of high-quality wurtzite MnSe nanorods. This success establishes that a facile strategy can be anticipated to synthesize high-quality metal chalcogenide NCs with a metastable phase, especially wurtzite nanorods, for potential applications from spintronics to solar cells. PMID:27064941

  15. Graphene/sulfur hybrid nanosheets from a space-confined "sauna" reaction for high-performance lithium-sulfur batteries.

    PubMed

    Fei, Linfeng; Li, Xiaogang; Bi, Wentuan; Zhuo, Zhiwen; Wei, Wenfei; Sun, Li; Lu, Wei; Wu, Xiaojun; Xie, Keyu; Wu, Changzheng; Chan, Helen L W; Wang, Yu

    2015-10-21

    A space-confined "sauna" reaction system is introduced for the simultaneous reduction and functionalization of graphene oxide to unique graphene-sulfur hybrid nanosheets, in which thin layers of amorphous sulfur are tightly anchored on the graphene sheet via strong chemical bonding. Upon being used as the cathode material in lithium-sulfur batteries, the as-synthesized composite shows an excellent electrochemical performance.

  16. Safe and Durable High-Temperature Lithium-Sulfur Batteries via Molecular Layer Deposited Coating.

    PubMed

    Li, Xia; Lushington, Andrew; Sun, Qian; Xiao, Wei; Liu, Jian; Wang, Biqiong; Ye, Yifan; Nie, Kaiqi; Hu, Yongfeng; Xiao, Qunfeng; Li, Ruying; Guo, Jinghua; Sham, Tsun-Kong; Sun, Xueliang

    2016-06-01

    Lithium-sulfur (Li-S) battery is a promising high energy storage candidate in electric vehicles. However, the commonly employed ether based electrolyte does not enable to realize safe high-temperature Li-S batteries due to the low boiling and flash temperatures. Traditional carbonate based electrolyte obtains safe physical properties at high temperature but does not complete reversible electrochemical reaction for most Li-S batteries. Here we realize safe high temperature Li-S batteries on universal carbon-sulfur electrodes by molecular layer deposited (MLD) alucone coating. Sulfur cathodes with MLD coating complete the reversible electrochemical process in carbonate electrolyte and exhibit a safe and ultrastable cycle life at high temperature, which promise practicable Li-S batteries for electric vehicles and other large-scale energy storage systems. PMID:27175936

  17. Safe and Durable High-Temperature Lithium-Sulfur Batteries via Molecular Layer Deposited Coating.

    PubMed

    Li, Xia; Lushington, Andrew; Sun, Qian; Xiao, Wei; Liu, Jian; Wang, Biqiong; Ye, Yifan; Nie, Kaiqi; Hu, Yongfeng; Xiao, Qunfeng; Li, Ruying; Guo, Jinghua; Sham, Tsun-Kong; Sun, Xueliang

    2016-06-01

    Lithium-sulfur (Li-S) battery is a promising high energy storage candidate in electric vehicles. However, the commonly employed ether based electrolyte does not enable to realize safe high-temperature Li-S batteries due to the low boiling and flash temperatures. Traditional carbonate based electrolyte obtains safe physical properties at high temperature but does not complete reversible electrochemical reaction for most Li-S batteries. Here we realize safe high temperature Li-S batteries on universal carbon-sulfur electrodes by molecular layer deposited (MLD) alucone coating. Sulfur cathodes with MLD coating complete the reversible electrochemical process in carbonate electrolyte and exhibit a safe and ultrastable cycle life at high temperature, which promise practicable Li-S batteries for electric vehicles and other large-scale energy storage systems.

  18. Sulfur Cycle

    NASA Technical Reports Server (NTRS)

    Hariss, R.; Niki, H.

    1985-01-01

    Among the general categories of tropospheric sulfur sources, anthropogenic sources have been quantified the most accurately. Research on fluxes of sulfur compounds from volcanic sources is now in progress. Natural sources of reduced sulfur compounds are highly variable in both space and time. Variables, such as soil temperature, hydrology (tidal and water table), and organic flux into the soil, all interact to determine microbial production and subsequent emissions of reduced sulfur compounds from anaerobic soils and sediments. Available information on sources of COS, CS2, DMS, and H2S to the troposphere in the following paragraphs are summarized; these are the major biogenic sulfur species with a clearly identified role in tropospheric chemistry. The oxidation of SO2 to H2SO4 can often have a significant impact on the acidity of precipitation. A schematic representation of some important transformations and sinks for selected sulfur species is illustrated.

  19. [Determination of sulfur in plant using a high-resolution continuum source atomic absorption spectrometer].

    PubMed

    Wang, Yu; Li, Jia-xi

    2009-05-01

    A method for the analysis of sulfur (S) in plant by molecular absorption of carbon monosulfide (CS) using a high-resolution continuum source atomic absorption spectrometer (CS AAS) with a fuel-rich air/acetylene flame has been devised. The strong CS absorption band was found around 258 nm. The half-widths of some absorption bands were of the order of picometers, the same as the common atomic absorption lines. The experimental procedure in this study provided optimized instrumental conditions (the ratio of acetylene to air, the burner height) and parameters, and researched the spectral interferences and chemical interferences. The influence of the organic solvents on the CS absorption signals and the different digestion procedures for the determination of sulfur were also investigated. The limit of detection achieved for sulfur was 14 mg x L(-1), using the CS wavelength of 257. 961 nm and a measurement time of 3 s. The accuracy and precision were verified by analysis of two plant standard reference materials. The major applications of this method have been used for the determination of sulfur in plant materials, such as leaves. Compared to the others, this method for the analysis of sulfur is rapid, easy and simple for sulfur determination in plant. PMID:19650504

  20. Permselective graphene oxide membrane for highly stable and anti-self-discharge lithium-sulfur batteries.

    PubMed

    Huang, Jia-Qi; Zhuang, Ting-Zhou; Zhang, Qiang; Peng, Hong-Jie; Chen, Cheng-Meng; Wei, Fei

    2015-03-24

    Lithium-sulfur batteries hold great promise for serving as next generation high energy density batteries. However, the shuttle of polysulfide induces rapid capacity degradation and poor cycling stability of lithium-sulfur cells. Herein, we proposed a unique lithium-sulfur battery configuration with an ultrathin graphene oxide (GO) membrane for high stability. The oxygen electronegative atoms modified GO into a polar plane, and the carboxyl groups acted as ion-hopping sites of positively charged species (Li(+)) and rejected the transportation of negatively charged species (Sn(2-)) due to the electrostatic interactions. Such electrostatic repulsion and physical inhibition largely decreased the transference of polysulfides across the GO membrane in the lithium-sulfur system. Consequently, the GO membrane with highly tunable functionalization properties, high mechanical strength, low electric conductivity, and facile fabrication procedure is an effective permselective separator system in lithium-sulfur batteries. By the incorporation of a permselective GO membrane, the cyclic capacity decay rate is also reduced from 0.49 to 0.23%/cycle. As the GO membrane blocks the diffusion of polysulfides through the membrane, it is also with advantages of anti-self-discharge properties.

  1. Production of low-sulfur binder pitch from high-sulfur Illinois coals. Technical report, December 1, 1994--February 28, 1995

    SciTech Connect

    Knight, R.A.

    1996-03-01

    The objective of this project is to produce electrode binder pitch with sulfur content below 0.6 wt% from high-sulfur Illinois coal mild gasification liquids. In previous ICCI projects at IGT, flash thermocracking (FTC) was used to successfully upgrade the properties of mild gasification pitch, yielding a suitable blending stock for use as a binder in the production of carbon electrodes for the aluminum industry. However, in pitches from high-sulfur (4%) Illinois coal, the pitch sulfur content is still unacceptably high at 2%. In this project, two approaches to sulfur reduction are being explored in conjunction with FTC: (1) the use of conventionally cleaned coal with low ({approximately}1%) sulfur as a mild gasification feedstock, and (2) direct biodesulfurization of the liquids prior to FTC. In Case 1, the crude pitch is being produced by mild gasification of IBC-109 coal in an existing IGT bench-scale reactor, followed by distillation to isolate the crude pitch. In Case 2, the crude pitch for biodesulfurization was obtained from Illinois No. 6 coal tests conducted in the IGT mild gasification PRU in 1990. Biodesulfurization is to be performed by contacting the pitch with Rhodococcus Rhodochrous IGTS8 biocatalyst. Following preparation of the crude pitches, pitch upgrading experiments are to be conducted in a continuous FTC reactor constructed in previous ICCI-sponsored studies. The finished pitch is then characterized for physical and chemical properties (density, softening point, QI, TI, coking value, and elemental composition), and compared to typical specifications for binder pitches.

  2. Production of low sulfur binder pitich from high-sulfur Illinois coals. Quarterly report, 1 March 1995--31 May 1995

    SciTech Connect

    Knight, R.A.

    1995-12-31

    The objective of this project is to produce electrode binder pitch with sulfur content below 0.6 wt% from high-sulfur Illinois coal mild gasification liquids. Previously, flash thermocracking (FTC) was used to successfully upgrade the properties of mild gasification pitch, yielding a suitable blending stock for use as a binder in the production of carbon electrodes for the aluminum industry. However, in pitches from high-sulfur (4%) Illinois coal, the pitch sulfur content (2%) was still higher than preferred. In this project two approaches to sulfur reduction are being explored in conjunction with FTC: (1) the use of a moderate-sulfur (1.2%) Illinois coal as mild gasification feedstock, and (2) direct biodesulfurization of the liquids from high-sulfur coal prior to FTC. In Case 1, the liquids are being produced by mild gasification of IBC-109 coal in a bench-scale fluidized-bed reactor, followed by distillation to isolate the crude pitch. In Case 2, biodesulfurization with Rhodococcus Rhodochrous IGTS8 biocatalyst is being performed on crude pitch obtained from Illinois No. 6 coal tests conducted in the IGT MILDGAS PRU in 1990. Following preparation of the crude pitches, pitch upgrading experiments are being conducted in a continuous FTC reactor constructed in previous ICCI-sponsored studies. This quarter, mild gasification of IBC-109 coal was completed, producing 450 g of coal liquids, which were then distilled to recover 329 g of Case 1 crude pitch. Next month, the pitch will be subjected to FTC treatment and evaluated. Biodesulfurization experiments were performed on Case 2 pitch dispersed in l-undecanol, resulting in sulfur reductions of 15.1 to 21.4%. This was marginally lower than the 24.8% desulfurization obtained in l-dodecanol, but separation of pitch from the dispersant was facilitated by the greater volatility of l-undecanol.

  3. Sulfur removal from high-sulfur Illinois coal by low-temperature perchloroethylene (PCE) extraction. Technical report, September 1, 1991--November 30, 1991

    SciTech Connect

    Chou, M.I.M.

    1991-12-31

    A pre-combustion coal desulfurization process at 120{degree}C using perchloroethylene (PCE) to remove up to 70% of the organic sulfur has been developed by the Midwest Ore Processing Co. (MWOPC). However, this process has not yet proven to be as successful with Illinois coals as it has for Ohio and Indiana coals. The organic sulfur removal has been achieved only with highly oxidized Illinois coals containing high sulfatic sulfur. A logical explanation for this observation is vital to successful process optimization for the use of Illinois coals. In addition, the high levels of organic sulfur removals observed by the MWOPC may be due to certain errors involved in the ASTM data interpretation; this needs verification. For example, elemental sulfur extracted by the PCE may be derived from pyrite oxidation during coal pre-oxidation, but it may be interpreted as organic sulfur removed by the PCE using ASTM analysis. The goals of this research are: (1) to independently confirm and possibly to improve the organic sulfur removal from Illinois coals with the PCE desulfurization process reported by the MWOPC, (2) to verify the forms-of-sulfur determination using the ASTM method for the PCE process evaluation, and (3) to determine the suitability of Illinois coals for use in the PCE desulfurization process. This project involves the Illinois State Geological Survey (ISGS), Eastern Illinois University (EIU), the University of Illinois-Urbana/Champaign (UI-UC), and the University of Kentucky, Lexington (UK). This is the first year of a two-year project.

  4. Foldable and High Sulfur Loading 3D Carbon Electrode for High-performance Li-S Battery Application

    PubMed Central

    He, Na; Zhong, Lei; Xiao, Min; Wang, Shuanjin; Han, Dongmei; Meng, Yuezhong

    2016-01-01

    Sulfur is a promising cathode material with a high theoretical capacity of 1672 mAh g−1, however, the practical energy density of Li-S battery is far away from such promising due to its low active material utilization and low sulfur loading. Moreover, the challenges of the low electrical conductivity of sulfur and the high solubility of polysulfide intermediates still hinder its practical application. Here, we report a kind of free-standing and foldable cathodes consisting of 3D activated carbon fiber matrix and sulfur cathode. The 3D activated carbon fiber matrix (ACFC) has continuous conductive framework and sufficient internal space to provide a long-distance and continuous high-speed electron pathway. It also gives a very larger internal space and tortuous cathode region to ACFC accommodate a highly sulfur loading and keeps polysulfide within the cathode. The unique structured 3D foldable sulfur cathode using a foldable ACFC as matrix delivers a reversible capacity of about 979 mAh g−1 at 0.2C, a capacity retention of 98% after 100 cycles, and 0.02% capacity attenuation per cycle. Even at an areal capacity of 6 mAh cm−2, which is 2 times higher than the values of Li-ion battery, it still maintains an excellent rate capability and cycling performance. PMID:27677602

  5. High temperature superconductivity in sulfur and selenium hydrides at high pressure

    NASA Astrophysics Data System (ADS)

    Flores-Livas, José A.; Sanna, Antonio; Gross, E. K. U.

    2016-03-01

    Due to its low atomic mass, hydrogen is the most promising element to search for high-temperature phononic superconductors. However, metallic phases of hydrogen are only expected at extreme pressures (400 GPa or higher). The measurement of the record superconducting critical temperature of 203 K in a hydrogen-sulfur compound at 160 GPa of pressure [A.P. Drozdov, M.I. Eremets, I.A. Troyan, arXiv:1412.0460; [cond-mat.supr-con] (2014); A.P. Drozdov, M.I. Eremets, I.A. Troyan, V. Ksenofontov, S.I. Shylin, Nature 525, 73 (2015)], shows that metallization of hydrogen can be reached at significantly lower pressure by inserting it in the matrix of other elements. In this work we investigate the phase diagram and the superconducting properties of the H-S systems by means of minima hopping method for structure prediction and density functional theory for superconductors. We also show that Se-H has a similar phase diagram as its sulfur counterpart as well as high superconducting critical temperature. We predict H3Se to exceed 120 K superconductivity at 100 GPa. We show that both H3Se and H3S, due to the critical temperature and peculiar electronic structure, present rather unusual superconducting properties. Supplementary material in the form of one pdf file available from the Journal web page at: http://dx.doi.org/10.1140/epjb/e2016-70020-0

  6. Synthesis of three-dimensionally interconnected sulfur-rich polymers for cathode materials of high-rate lithium–sulfur batteries

    PubMed Central

    Kim, Hoon; Lee, Joungphil; Ahn, Hyungmin; Kim, Onnuri; Park, Moon Jeong

    2015-01-01

    Elemental sulfur is one of the most attractive cathode active materials in lithium batteries because of its high theoretical specific capacity. Despite the positive aspect, lithium–sulfur batteries have suffered from severe capacity fading and limited rate capability. Here we report facile large-scale synthesis of a class of organosulfur compounds that could open a new chapter in designing cathode materials to advance lithium–sulfur battery technologies. Porous trithiocyanuric acid crystals are synthesized for use as a soft template, where the ring-opening polymerization of elemental sulfur takes place along the thiol surfaces to create three-dimensionally interconnected sulfur-rich phases. Our lithium–sulfur cells display discharge capacity of 945 mAh g−1 after 100 cycles at 0.2 C with high-capacity retention of 92%, as well as lifetimes of 450 cycles. Particularly, the organized amine groups in the crystals increase Li+-ion transfer rate, affording a rate performance of 1210, mAh g−1 at 0.1 C and 730 mAh g−1 at 5 C. PMID:26065407

  7. Extraction, separation and analysis of high sulfur coal

    SciTech Connect

    Olesik, S.V.

    1990-04-02

    In summary, significant bond cleavage was found only for thiophenol under the supercritical conditions studied. Less than 5% yield was found for the observed reaction products for all the other organosulfur compounds. The hydrogen sulfur bond in thiophenol is clearly the weakest of those studied and therefore it is the easiest to rupture. Also a general trend was observed the solvolysis reaction products such as ethylthiobenzene were the products initially formed at lower temperatures. But with higher temperatures the reaction product were those typically produced from the bimolecular association of free-radicals, such as phenylsulfide for the thiophenol sample. This type of reaction would be expected in pyrolysis reactions. Bimolecular reactions between organosulfur compounds would not be expected when the reaction is occurring at the surface of the solid coal matrix. The probability of the extracted organosulfur radicals having such bimolecular reactions is quite low. However, the reactions that are observed from the interaction of supercritical ethanol and the model coal compounds are not ones that show obvious indications of desulfurization of the compound.

  8. A high-density graphene-sulfur assembly: a promising cathode for compact Li-S batteries

    NASA Astrophysics Data System (ADS)

    Zhang, Chen; Liu, Dong-Hai; Lv, Wei; Wang, Da-Wei; Wei, Wei; Zhou, Guang-Min; Wang, Shaogang; Li, Feng; Li, Bao-Hua; Kang, Feiyu; Yang, Quan-Hong

    2015-03-01

    This work reports a high-density graphene/sulfur assembly for compact Li-S batteries with high volumetric capacity, which retains good structural stability and conductivity. This dense assembly was prepared by a reduction-triggered self-assembly of graphene oxide with simultaneous deposition of sulfur, followed by unique evaporation-induced spatial volume shrinkage. This assembly has an ultrahigh density, delivering an unprecedented volumetric capacity that is much higher than common carbon/sulfur cathodes. In particular, the unique spatial confinement derived from the shrinkage of the graphene/sulfur assembly is favorable for stabilizing sulfur cathodes.This work reports a high-density graphene/sulfur assembly for compact Li-S batteries with high volumetric capacity, which retains good structural stability and conductivity. This dense assembly was prepared by a reduction-triggered self-assembly of graphene oxide with simultaneous deposition of sulfur, followed by unique evaporation-induced spatial volume shrinkage. This assembly has an ultrahigh density, delivering an unprecedented volumetric capacity that is much higher than common carbon/sulfur cathodes. In particular, the unique spatial confinement derived from the shrinkage of the graphene/sulfur assembly is favorable for stabilizing sulfur cathodes. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr06863g

  9. Hierarchically Structured Sulfur/Carbon Nanocomposite Material for High Energy Lithium Battery

    SciTech Connect

    Liang, Chengdu; Dudney, Nancy J; Howe, Jane Y

    2009-01-01

    We report herein a hierarchically structured sulfur-carbon (S/C) nanocomposite material as the high surface-area cathode for rechargeable lithium batteries. A porous carbon with a uniform distribution of mesopores of 7.3 nm has been synthesized through a soft-template synthesis method. The potassium hydroxide activation of this mesoporous carbon results in a bimodal porous carbon with added microporosity of less than 2 nm to the existing mesopores without deterioration of the integrity of the original mesoporous carbon. Elemental sulfur has been loaded to the micropores through a solution infiltration method. The resulted S/C composites with various loading level of sulfur have a high surface areas and large internal porosities. These materials have been tested as novel cathodes for Li/S batteries. The results show that the cyclability and the utilization of sulfur in the Li/S batteries have been significantly improved. The large internal porosity and surface area of the micro-mesoporous carbon is essential for retaining sulfur in the cathode and therefore maximizing the capacity and lifespan of the cathode.

  10. Theoretical studies on a new high energy density compound 6-amino-7-nitropyrazino[2,3-e][1,2,3,4]tetrazine 1,3,5-trioxide (ANPTTO).

    PubMed

    Wang, Tianyi; Zheng, Chunmei; Yang, Junqing; Zhang, Xueli; Gong, Xuedong; Xia, Mingzhu

    2014-06-01

    The derivatives of 1,2,3,4-tetrazine may be promising candidates for high-energy density compounds and are receiving more and more attentions. In this study, a new derivative 6-amino-7-nitropyrazino[2,3-e][1,2,3,4]tetrazine 1,3,5-trioxide (ANPTTO) has been designed. The geometrical structure and IR spectrum in the gas phase were studied at the B3LYP/6-31G* level of density functional theory (DFT). The crystal structure was predicted by molecular mechanics method and refined by the GGA/BOP function of periodic DFT with the basis set of TNP. The gas phase enthalpy of formation was calculated by the homodesmotic reaction method. The enthalpy of sublimation and solid phase enthalpy of formation were also predicted. The detonation properties were estimated with the Kamlet-Jacobs equations based on the predicted density and enthalpy of formation in solid state. The available free space in the lattice and resonance energy were calculated to evaluate its stability. ANPTTO has a high stability and is a promising high energetic component with the density >2 g · cm(-3), detonation velocity >9000 m · s(-1), and detonation pressure >40 GPa. A synthetic route was proposed to provide a consideration for further study.

  11. Sulfur incorporation in high level nuclear waste glass: A S K-edge XAFS investigation

    NASA Astrophysics Data System (ADS)

    Brendebach, B.; Denecke, M. A.; Roth, G.; Weisenburger, S.

    2009-11-01

    We perform X-ray absorption fine structure (XAFS) spectroscopy measurements at the sulfur K-edge to elucidate the electronic and geometric bonding of sulfur atoms in borosilicate glass used for the vitrification of high level radioactive liquid waste. The sulfur is incorporated as sulfate, most probably as sodium sulfate, which can be deduced from the X-ray absorption near edge structure (XANES) by fingerprint comparison with reference compounds. This finding is backed up by Raman spectroscopy investigation. In the extended XAFS data, no second shell beyond the first oxygen layer is visible. We argue that this is due to the sulfate being present as small clusters located into voids of the borosilicate network. Hence, destructive interference of the variable surrounding prohibits the presence of higher shell signals. The knowledge of the sulfur bonding characteristics is essential for further optimization of the glass composition and to balance the requirements of the process and glass quality parameters, viscosity and electrical resistivity on one side, waste loading and sulfur uptake on the other side.

  12. Co-firing with waste wood to upgrade high-sulfur coal

    SciTech Connect

    Badger, P.C.

    1997-12-31

    Co-firing large coal-fired utility boilers with a mixture of wood and coal is potentially attractive for several reasons: wood can be used to reduce sulfur dioxide emissions; wood reduces the amount of fossil carbon dioxide emissions. Experiments have indicated that about 4 percent of coal can be replaced by wood without adding additional equipment. This article analyses the use of wood for co-firing with high sulfur coal in Kentucky and Tennessee using models and economic evaluation. Potential problems are mentioned. 1 fig., 1 tab.

  13. An experimental study on desulfurization of high-sulfur coal slime with free jet flotation column

    SciTech Connect

    Xie Hua; Huang Bo; Xia Qing

    1998-12-31

    A free jet flotation column gives good selectivity and high separation efficiency in treating fine and ultra-fine coal. This paper reports test results of coal desulfurization with a free jet flotation column. Test results showed that when the coal sample from Zhong Liang Shan was processed its pyritic sulfur content was reduced from 3.08% to 0.84%, with 72.22% recovery of combustible matter in clean coal. The concept of Desulfurization Efficiency Index E(ds) for a comprehensive evaluation of desulfurization process is proposed, which is defined as the product of the ratio of sulfur content reduction and the recovery of combustible matters in clean coal.

  14. High-resolution sulfur isotopes in ice cores identify large stratospheric volcanic eruptions

    NASA Astrophysics Data System (ADS)

    Burke, Andrea; Sigl, Michael; Adkins, Jess; Paris, Guillaume; McConnell, Joe

    2016-04-01

    The record of the volcanic forcing of climate over the past 2500 years is reconstructed primarily from sulfate concentrations in ice cores. Of particular interest are stratospheric eruptions, as these afford sulfate aerosols the longest residence time and largest dispersion in the atmosphere, and thus the greatest impact on radiative forcing. Identification of stratospheric eruptions currently relies on the successful matching of the same volcanic sulphate peak in ice cores from both the Northern and Southern hemispheres (a "bipolar event"). These are interpreted to reflect the global distribution of sulfur aerosols by the stratospheric winds. Despite its recent success, this method relies on precise and accurate dating of ice cores, in order to distinguish between a true 'bipolar event' and two separate eruptions that occurred in close temporal succession. Sulfur isotopes can been used to distinguish between these two scenarios since stratospheric sulfur aerosols are exposed to UV radiation which imparts a mass independent fractionation (Baroni et al., 2007). Mass independent fractionation of sulfate in ice cores thus offers a novel method of fingerprinting stratospheric eruptions, and thus refining the historic record of explosive volcanism and its forcing of climate. Here we present new high-resolution (sub-annual) sulfur isotope data from the Tunu Ice core in Greenland over seven eruptions. Sulfur isotopes were measured by MC-ICP-MS, which substantially reduces sample size requirements and allows high temporal resolution from a single ice core. We demonstrate the efficacy of the method on recent, well-known eruptions (including Pinatubo and Katmai/Novarupta), and then apply it to unidentified sulfate peaks, allowing us to identify new stratospheric eruptions. Baroni, M., Thiemens, M. H., Delmas, R. J., & Savarino, J. (2007). Mass-independent sulfur isotopic compositions in stratospheric volcanic eruptions. Science, 315(5808), 84-87. http://doi.org/10

  15. Alternative motif toward high-quality wurtzite MnSe nanorods via subtle sulfur element doping

    NASA Astrophysics Data System (ADS)

    Zhou, Bo; Yang, Xinyi; Sui, Yongming; Xiao, Guanjun; Wei, Yingjin; Zou, Bo

    2016-04-01

    The manipulated synthesis of high-quality semiconductor nanocrystals (NCs) is of high significance with respect to the exploration of their properties and their corresponding applications. Nevertheless, the preparation of metastable-phase NCs still remains a great challenge due to their high kinetic barriers and harsh synthetic conditions. Herein, we demonstrated the fabrication of high-quality MnSe nanorods with a metastable wurtzite structure via a subtle sulfur-doping strategy. Based on the UV-vis absorption spectra, manganese polysulfide clusters were formed by mixing oleylamine-sulfur and oleylamine-manganese solutions at room temperature. The existence of manganese polysulfide clusters with polymeric sulfur structures makes the system more reactive, inducing fast wurtzite-phase nucleation. This can overcome the natural kinetic barrier of wurtzite MnSe and lead to subsequent growth of targeted NCs. On the other hand, no sulfur doping would produce MnSe NCs in a thermodynamically favorable rock-salt phase. As expected, different doping contents and sulfur sources also resulted in the formation of high-quality wurtzite MnSe nanorods. This success establishes that a facile strategy can be anticipated to synthesize high-quality metal chalcogenide NCs with a metastable phase, especially wurtzite nanorods, for potential applications from spintronics to solar cells.The manipulated synthesis of high-quality semiconductor nanocrystals (NCs) is of high significance with respect to the exploration of their properties and their corresponding applications. Nevertheless, the preparation of metastable-phase NCs still remains a great challenge due to their high kinetic barriers and harsh synthetic conditions. Herein, we demonstrated the fabrication of high-quality MnSe nanorods with a metastable wurtzite structure via a subtle sulfur-doping strategy. Based on the UV-vis absorption spectra, manganese polysulfide clusters were formed by mixing oleylamine-sulfur and oleylamine

  16. A low cost, high energy density, and long cycle life potassium-sulfur battery for grid-scale energy storage.

    PubMed

    Lu, Xiaochuan; Bowden, Mark E; Sprenkle, Vincent L; Liu, Jun

    2015-10-21

    A potassium-sulfur battery using K(+) -conducting beta-alumina as the electrolyte to separate a molten potassium metal anode and a sulfur cathode is presented. The results indicate that the battery can operate at as low as 150 °C with excellent performance. This study demonstrates a new type of high-performance metal-sulfur battery that is ideal for grid-scale energy-storage applications.

  17. Determination of sulfur in food by high resolution continuum source flame molecular absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Zambrzycka, Elżbieta; Godlewska-Żyłkiewicz, Beata

    2014-11-01

    In the present work, a fast, simple and sensitive analytical method for determination of sulfur in food and beverages by high resolution continuum source flame molecular absorption spectrometry was developed. The determination was performed via molecular absorption of carbon monosulfide, CS. Different CS rotational lines (257.959 nm, 258.033 nm, 258.055 nm), number of pixels and types of standard solution of sulfur, namely: sulfuric acid, sodium sulfate, ammonium sulfate, sodium sulfite, sodium sulfide, DL-cysteine, and L-cystine, were studied in terms of sensitivity, repeatability of results as well as limit of detection and limit of quantification. The best results were obtained for measurements of absorption of the CS molecule at 258.055 nm at the wavelength range covering 3 pixels and DL-cysteine in 0.2 mol L- 1 HNO3 solution as a calibration standard. Under optimized conditions the limit of detection and the limit of quantification achieved for sulfur were 10.9 mg L- 1 and 36.4 mg L- 1, respectively. The repeatability of the results expressed as relative standard deviation was typically < 5%. The accuracy of the method was tested by analysis of digested biological certified reference materials (soya bean flour, corn flour and herbs) and recovery experiment for beverage samples with added known amount of sulfur standard. The recovery of analyte from such samples was in the range of 93-105% with the repeatability in the range of 4.1-5.0%. The developed method was applied for the determination of sulfur in milk (194 ± 10 mg kg- 1), egg white (2188 ± 29 mg kg- 1), mineral water (31.0 ± 0.9 mg L- 1), white wine (260 ± 4 mg L- 1) and red wine (82 ± 2 mg L- 1), as well as in sample rich in ions, such as bitter mineral water (6900 ± 100 mg L- 1).

  18. Co-firing high sulfur coal with refuse derived fuels. Final report

    SciTech Connect

    Pan, W.P.; Riley, J.T.; Lloyd, W.G.

    1997-11-30

    This project was designed to evaluate the combustion performance of and emissions from a fluidized bed combustor during the combustion of mixtures of high sulfur and/or high chlorine coals and municipal solid waste (MSW). The project included four major tasks, which were as follows: (1) Selection, acquisition, and characterization of raw materials for fuels and the determination of combustion profiles of combination fuels using thermal analytical techniques; (2) Studies of the mechanisms for the formation of chlorinated organics during the combustion of MSW using a tube furnace; (3) Investigation of the effect of sulfur species on the formation of chlorinated organics; and (4) Examination of the combustion performance of combination fuels in a laboratory scale fluidized bed combustor. Several kinds of coals and the major combustible components of the MSW, including PVC, newspaper, and cellulose were tested in this project. Coals with a wide range of sulfur and chlorine contents were used. TGA/MS/FTIR analyses were performed on the raw materials and their blends. The possible mechanism for the formation of chlorinated organics during combustion was investigated by conducting a series of experiments in a tube furnace. The effect of sulfur dioxide on the formation of molecular chlorine during combustion processes was examined in this study.

  19. Sulfur/graphitic hollow carbon sphere nano-composite as a cathode material for high-power lithium-sulfur battery

    PubMed Central

    2013-01-01

    The intrinsic low conductivity of sulfur which leads to a low performance at a high current rate is one of the most limiting factors for the commercialization of lithium-sulfur battery. Here, we present an easy and convenient method to synthesize a mono-dispersed hollow carbon sphere with a thin graphitic wall which can be utilized as a support with a good electrical conductivity for the preparation of sulfur/carbon nano-composite cathode. The hollow carbon sphere was prepared from the pyrolysis of the homogenous mixture of the mono-dispersed spherical silica and Fe-phthalocyanine powder in elevated temperature. The composite cathode was manufactured by infiltrating sulfur melt into the inner side of the graphitic wall. The electrochemical cycling shows a capacity of 425 mAh g−1 at 3 C current rate which is more than five times larger than that for the sulfur/carbon black nano-composite prepared by simple ball milling. PMID:23914902

  20. Advanced sulfur control concepts in hot-gas desulfurization technology: Phase 1, Feasibility of the direct production of elemental sulfur during the regeneration of high temperature desulfurization sorbents

    SciTech Connect

    Lopez, A.; White, J.; Groves, F.R.; Harrison, D.P.

    1994-10-01

    This topical report de-scribes the results of Phase 1 research performed during the first six months of a three-year contract to study the feasibility of the direct production of elemental sulfur during the regeneration of high temperature desulfurization sorbents. Much effort has gone into the development of a high-temperature meal oxide sorbent process for removal of H{sub 2}S from the coal gas. A number of sorbents based upon metals such as zinc, iron, manganese and others have been studied. In order for high temperature desulfurization to be economical it is necessary that the sorbents be regenerated to permit multicycle operation. Current methods of sorbent regeneration involve oxidation of the metal sulfide to reform the metal oxide and free the sulfur as SO{sub 2}. An alternate regeneration process in which the sulfur is liberated in elemental form is preferable. The overall objective of the current research is to study simpler and economically superior processing of known sorbents capable of producing elemental sulfur during regeneration. This topical report summarizes the first steps of this effort. A literature search has been completed to identify possible regeneration concepts and to collect relevant thermodynamic, kinetic, and process data. Three concepts involving reaction with SO{sub 2}, partial oxidation using an O{sub 2} {minus} H{sub 2}O mixture, and steam regeneration have been identified. The first two concepts result in the direct production of elemental sulfur while H{sub 2}S is the product of steam regeneration. This concept is of potential interest, however, since existing Claus technology can be used to convert H{sub 2}S to elemental sulfur. Following the literature search, a thermodynamic analysis, based upon free-energy minimization was carried out to evaluate candidate sorbents for possible use with the three regeneration concepts.

  1. Destruction of a high sulfur pitch in an industrial scale fluidized bed combustor

    SciTech Connect

    North, B.; Eleftheriades, C.; Engelbrecht, A.; Rutherford-Jones, J.

    1999-07-01

    Sasol approached the CSIR's division of Materials Science and Technology (CSIR Mattek) for an environmentally acceptable solution to their steadily increasing stockpiles of a high sulfur pitch. Conventional incineration of the pitch would result in unacceptably high levels of sulfur dioxide emission to the atmosphere. In addition to the pitch, Sasol indicated a need to dispose of a waste water stream contaminated with organic compounds. After some initial development work CSIR Mattek, in conjunction with its licensee IMS Process Plant, presented a design for a multipurpose bubbling fluidized bed incineration plant that completely destroys the pitch and effluent water while capturing a minimum of 85% of the incoming sulfur in the pitch by limestone injection. The plant design caters for the variable consistency of both the pitch and the organic waste water, which can contain from 0 to 10% organics. The design also allows for potential future treatment of contaminated soils. In addition to the environment benefit of the reduction of sulfur dioxide emissions, the plant also makes use of the hot combustion gases to raise 20 t/hr of saturated steam at 20 bar via an external waste heat boiler. This represents a valuable commodity for the business unit responsible for the waste incineration and makes the Sasol plant a more energy efficient entity. It also represents a net reduction in CO{sub 2} emissions from Sasol. The high sulfur pitch incineration plant was commissioned in Sasolburg by a team of engineers from CSIR Mattek, IMS Process Plant and Sasol during December 1996 and January/February 1997. The plant has performed extremely well and it has complied with the environmental emission requirements as set out by the Department of Environmental Affairs and Tourism.

  2. Synergistic Ultrathin Functional Polymer-Coated Carbon Nanotube Interlayer for High Performance Lithium-Sulfur Batteries.

    PubMed

    Kim, Joo Hyun; Seo, Jihoon; Choi, Junghyun; Shin, Donghyeok; Carter, Marcus; Jeon, Yeryung; Wang, Chengwei; Hu, Liangbing; Paik, Ungyu

    2016-08-10

    Lithium-sulfur (Li-S) batteries have been intensively investigated as a next-generation rechargeable battery due to their high energy density of 2600 W·h kg(-1) and low cost. However, the systemic issues of Li-S batteries, such as the polysulfide shuttling effect and low Coulombic efficiency, hinder the practical use in commercial rechargeable batteries. The introduction of a conductive interlayer between the sulfur cathode and separator is a promising approach that has shown the dramatic improvements in Li-S batteries. The previous interlayer work mainly focused on the physical confinement of polysulfides within the cathode part, without considering the further entrapment of the dissolved polysulfides. Here, we designed an ultrathin poly(acrylic acid) coated single-walled carbon nanotube (PAA-SWNT) film as a synergic functional interlayer to address the issues mentioned above. The designed interlayer not only lowers the charge transfer resistance by the support of the upper current collector but also localizes the dissolved polysulfides within the cathode part by the aid of a physical blocking and chemical bonding. With the synergic combination of PAA and SWNT, the sulfur cathode with a PAA-SWNT interlayer maintained higher capacity retention over 200 cycles and achieved better rate retention than the sulfur cathode with a SWNT interlayer. The proposed approach of combining a functional polymer and conductive support material can provide an optimiztic strategy to overcome the fundamental challenges underlying in Li-S batteries. PMID:27437758

  3. Synergistic Ultrathin Functional Polymer-Coated Carbon Nanotube Interlayer for High Performance Lithium-Sulfur Batteries.

    PubMed

    Kim, Joo Hyun; Seo, Jihoon; Choi, Junghyun; Shin, Donghyeok; Carter, Marcus; Jeon, Yeryung; Wang, Chengwei; Hu, Liangbing; Paik, Ungyu

    2016-08-10

    Lithium-sulfur (Li-S) batteries have been intensively investigated as a next-generation rechargeable battery due to their high energy density of 2600 W·h kg(-1) and low cost. However, the systemic issues of Li-S batteries, such as the polysulfide shuttling effect and low Coulombic efficiency, hinder the practical use in commercial rechargeable batteries. The introduction of a conductive interlayer between the sulfur cathode and separator is a promising approach that has shown the dramatic improvements in Li-S batteries. The previous interlayer work mainly focused on the physical confinement of polysulfides within the cathode part, without considering the further entrapment of the dissolved polysulfides. Here, we designed an ultrathin poly(acrylic acid) coated single-walled carbon nanotube (PAA-SWNT) film as a synergic functional interlayer to address the issues mentioned above. The designed interlayer not only lowers the charge transfer resistance by the support of the upper current collector but also localizes the dissolved polysulfides within the cathode part by the aid of a physical blocking and chemical bonding. With the synergic combination of PAA and SWNT, the sulfur cathode with a PAA-SWNT interlayer maintained higher capacity retention over 200 cycles and achieved better rate retention than the sulfur cathode with a SWNT interlayer. The proposed approach of combining a functional polymer and conductive support material can provide an optimiztic strategy to overcome the fundamental challenges underlying in Li-S batteries.

  4. Bioconversion of high concentrations of hydrogen sulfide to elemental sulfur in airlift bioreactor.

    PubMed

    Zytoon, Mohamed Abdel-Monaem; AlZahrani, Abdulraheem Ahmad; Noweir, Madbuli Hamed; El-Marakby, Fadia Ahmed

    2014-01-01

    Several bioreactor systems are used for biological treatment of hydrogen sulfide. Among these, airlift bioreactors are promising for the bioconversion of hydrogen sulfide into elemental sulfur. The performance of airlift bioreactors is not adequately understood, particularly when directly fed with hydrogen sulfide gas. The objective of this paper is to investigate the performance of an airlift bioreactor fed with high concentrations of H2S with special emphasis on the effect of pH in combination with other factors such as H2S loading rate, oxygen availability, and sulfide accumulation. H2S inlet concentrations between 1,008 ppm and 31,215 ppm were applied and elimination capacities up to 113 g H2S m(-3) h(-1) were achieved in the airlift bioreactor under investigation at a pH range 6.5-8.5. Acidic pH values reduced the elimination capacity. Elemental sulfur recovery up to 95% was achieved under oxygen limited conditions (DO < 0.2 mg/L) and at higher pH values. The sulfur oxidizing bacteria in the bioreactor tolerated accumulated dissolved sulfide concentrations >500 mg/L at pH values 8.0-8.5, and near 100% removal efficiency was achieved. Overall, the resident microorganisms in the studied airlift bioreactor favored pH values in the alkaline range. The bioreactor performance in terms of elimination capacity and sulfur recovery was better at pH range 8-8.5.

  5. High conductivity glass electrolytes for sodium/sulfur batteries

    NASA Astrophysics Data System (ADS)

    Bloom, I.; Nelson, P. A.; Roche, M. F.

    1986-06-01

    High-soda glasses in the Na2O-ZrO2-Al2O3-SiO2 system were tested for low resistivity and stability in Na, Na2S4, S, and Na2S3. The composition that was selected was: 42 mol% Na2O, 8 mol% Al2O3, 5 mol% ZrO2, and 45 mol% SiO2. Effects of tube diameter on specific power and energy were studied.

  6. High rate lithium-sulfur battery enabled by sandwiched single ion conducting polymer electrolyte

    PubMed Central

    Sun, Yubao; Li, Gai; Lai, Yuanchu; Zeng, Danli; Cheng, Hansong

    2016-01-01

    Lithium-sulfur batteries are highly promising for electric energy storage with high energy density, abundant resources and low cost. However, the battery technologies have often suffered from a short cycle life and poor rate stability arising from the well-known “polysulfide shuttle” effect. Here, we report a novel cell design by sandwiching a sp3 boron based single ion conducting polymer electrolyte film between two carbon films to fabricate a composite separator for lithium-sulfur batteries. The dense negative charges uniformly distributed in the electrolyte membrane inherently prohibit transport of polysulfide anions formed in the cathode inside the polymer matrix and effectively blocks polysulfide shuttling. A battery assembled with the composite separator exhibits a remarkably long cycle life at high charge/discharge rates. PMID:26898772

  7. High rate lithium-sulfur battery enabled by sandwiched single ion conducting polymer electrolyte

    NASA Astrophysics Data System (ADS)

    Sun, Yubao; Li, Gai; Lai, Yuanchu; Zeng, Danli; Cheng, Hansong

    2016-02-01

    Lithium-sulfur batteries are highly promising for electric energy storage with high energy density, abundant resources and low cost. However, the battery technologies have often suffered from a short cycle life and poor rate stability arising from the well-known “polysulfide shuttle” effect. Here, we report a novel cell design by sandwiching a sp3 boron based single ion conducting polymer electrolyte film between two carbon films to fabricate a composite separator for lithium-sulfur batteries. The dense negative charges uniformly distributed in the electrolyte membrane inherently prohibit transport of polysulfide anions formed in the cathode inside the polymer matrix and effectively blocks polysulfide shuttling. A battery assembled with the composite separator exhibits a remarkably long cycle life at high charge/discharge rates.

  8. High rate lithium-sulfur battery enabled by sandwiched single ion conducting polymer electrolyte.

    PubMed

    Sun, Yubao; Li, Gai; Lai, Yuanchu; Zeng, Danli; Cheng, Hansong

    2016-02-22

    Lithium-sulfur batteries are highly promising for electric energy storage with high energy density, abundant resources and low cost. However, the battery technologies have often suffered from a short cycle life and poor rate stability arising from the well-known "polysulfide shuttle" effect. Here, we report a novel cell design by sandwiching a sp(3) boron based single ion conducting polymer electrolyte film between two carbon films to fabricate a composite separator for lithium-sulfur batteries. The dense negative charges uniformly distributed in the electrolyte membrane inherently prohibit transport of polysulfide anions formed in the cathode inside the polymer matrix and effectively blocks polysulfide shuttling. A battery assembled with the composite separator exhibits a remarkably long cycle life at high charge/discharge rates.

  9. Lunar sulfur

    NASA Technical Reports Server (NTRS)

    Kuck, David L.

    1991-01-01

    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.

  10. Lunar sulfur

    NASA Astrophysics Data System (ADS)

    Kuck, David L.

    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.

  11. High-voltage electrical apparatus utilizing an insulating gas of sulfur hexafluoride and helium

    DOEpatents

    Wootton, Roy E.

    1980-01-01

    High-voltage electrical apparatus includes an outer housing at low potential, an inner electrode disposed within the outer housing at high potential with respect thereto, and support means for insulatably supporting the inner electrode within the outer housing. Conducting particles contaminate the interior of the outer housing, and an insulating gas electrically insulates the inner electrode from the outer housing even in the presence of the conducting particles. The insulating gas is comprised of sulfur hexafluoride at a partial pressure of from about 2.9 to about 3.4 atmospheres absolute, and helium at a partial pressure from about 1.1 to about 11.4 atmospheres absolute. The sulfur hexafluoride comprises between 20 and 65 volume percent of the insulating gas.

  12. Hybrid sulfur cycle operation for high-temperature gas-cooled reactors

    DOEpatents

    Gorensek, Maximilian B

    2015-02-17

    A hybrid sulfur (HyS) cycle process for the production of hydrogen is provided. The process uses a proton exchange membrane (PEM) SO.sub.2-depolarized electrolyzer (SDE) for the low-temperature, electrochemical reaction step and a bayonet reactor for the high-temperature decomposition step The process can be operated at lower temperature and pressure ranges while still providing an overall energy efficient cycle process.

  13. A high-efficiency indirect lighting system utilizing the solar 1000 sulfur lamp

    SciTech Connect

    Siminovitch, M.; Gould, C.; Page, E.

    1997-06-01

    High-lumen light sources represent unique challenges and opportunities for the design of practical and efficient interior lighting systems. High-output sources require a means of large-scale distribution and avoidance of high-luminance glare while providing efficient delivery. An indirect lighting system has been developed for use with a 1,000 Watt sulfur lamp that efficiently utilizes the high-output source to provide quality interior lighting. This paper briefly describes the design and initial testing of this new system.

  14. SnO2 as a high-efficiency polysulfide trap in lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Liu, Jing; Yuan, Lixia; Yuan, Kai; Li, Zhen; Hao, Zhangxiang; Xiang, Jingwei; Huang, Yunhui

    2016-07-01

    The ithium-sulfur battery stands as one of the most promising successors of traditional lithium-ion batteries due to its super high theoretical energy density, but practical application still suffers from the shuttle effect arising from soluble intermediate polysulfides. Here, we report SnO2 as a chemical adsorbent for polysulfides. As an interlayer between the cathode and separator, SnO2 gives better results to prevent the polysulfides from diffusing to the lithium anode than as a modifier of the carbon matrix directly. The lithium-sulfur battery with an SnO2 interlayer delivers an initial reversible capacity of 996 mA h g-1 and retains 832 mA h g-1 at the 100th discharge at 0.5 C, with a fading rate of only 0.19% per cycle. The improvements benefit from the quasi-open space provided by the interlayer configuration for the diffused sulfur species, which can largely relieve the loss of active substances caused by the volume effect during the lithiation/delithiation process.The ithium-sulfur battery stands as one of the most promising successors of traditional lithium-ion batteries due to its super high theoretical energy density, but practical application still suffers from the shuttle effect arising from soluble intermediate polysulfides. Here, we report SnO2 as a chemical adsorbent for polysulfides. As an interlayer between the cathode and separator, SnO2 gives better results to prevent the polysulfides from diffusing to the lithium anode than as a modifier of the carbon matrix directly. The lithium-sulfur battery with an SnO2 interlayer delivers an initial reversible capacity of 996 mA h g-1 and retains 832 mA h g-1 at the 100th discharge at 0.5 C, with a fading rate of only 0.19% per cycle. The improvements benefit from the quasi-open space provided by the interlayer configuration for the diffused sulfur species, which can largely relieve the loss of active substances caused by the volume effect during the lithiation/delithiation process. Electronic

  15. Sulfurization of α-MoO{sub 3} nanostructured thin film

    SciTech Connect

    Kumar, Prabhat; Singh, Megha; Sharma, Rabindar K. Reddy, G. B.

    2015-08-28

    In this report, the sulfurization of vertically aligned molybdenum trioxide (α- MoO{sub 3}) nanoflakes (NFs) with high aspect ratio (height/thickness >20) on the nickel coated glass substrates in a mixture of H{sub 2}S and argon gas at atmospheric pressure has been studied. The effect of sulfurization have been investigated to understand the basic reaction mechanism and the morphology, structural properties of grown nanoflakes. XPS and XRD indicate the formation of MoS{sub 2} along with the other intermediate phase such as MoO{sub 2} at temperature 200 °C. The surface morphology of samples have been studied systematically by using scanning electron microscope (SEM). The results demonstrate partial conversion of MoO{sub 3} NFs into MoS{sub 2} along with the change in the morphology of nanoflakes. All the observed results are well in consonance with each other.

  16. Constitutive expression of high-affinity sulfate transporter (HAST) gene in Indian mustard showed enhanced sulfur uptake and assimilation.

    PubMed

    Abdin, M Z; Akmal, M; Ram, M; Nafis, T; Alam, P; Nadeem, M; Khan, M A; Ahmad, A

    2011-07-01

    Lycopersicon esculantum sulfate transporter gene (LeST 1.1) encodes a high-affinity sulfate transporter (HAST) located in root epidermis. In this study, the LeST 1.1 gene was constitutively expressed in Indian mustard (Brassica juncea cv. Pusa Jai Kisan). Transgenic as well as untransformed plants were grown in sulfur-insufficient (25 and 50 μM) and sulfur-sufficient (1,000 μM) conditions for 30 days. Two-fold increase was noticed in the sulfate uptake rate of transgenic plants grown in both sulfur-insufficient and -sufficient conditions as compared to untransformed plants. The transgenic B. juncea plants were able to accumulate higher biomass and showed improved sulfur status even in sulfur-insufficient conditions when compared with untransformed plants. Chlorophyll content, ATP sulfurylase activity and protein content were also higher in transgenic plants than untranformed plants under sulfur-insufficient conditions. Our results, thus, clearly indicate that constitutive expression of LeST 1.1 gene in B. juncea had led to enhanced capacity of sulfur uptake and assimilation even in sulfur-insufficient conditions. This approach can also be used in other crops to enhance their sulfate uptake and assimilation potential under S-insufficient conditions. PMID:20938698

  17. Co-firing high sulfur coal with refuse derived fuels. Quarterly report, October - December 1996

    SciTech Connect

    Pan, W.-P.; Riley, J.T.; Lloyd, W.G.

    1996-12-01

    The objectives of this quarter of study on the co-firing of high sulfur coal with refuse derived fuels project were two-fold. First, the effect of S0{sub 2} on the formation of chlorine during combustion processes was examined. To simulate the conditions used in the AFBC system, experiments were conducted in a quartz tube in an electrically heated furnace. The principle analytical technique used for identification of the products from this study was GC/MS. The evolved gas was trapped by an absorbent and analyzed with a GC/MS system. The preliminary results indicate an inhibiting effect of S0{sub 2} on the Deacon Reaction. Secondly, information on the evolution of chlorine, sulfur and organic compounds from coals 95031 and 95011 were studied with the AFBC system. 2 figs., 1 tab.

  18. High Resolution He-like Argon And Sulfur Spectra From The PSI ECRIT

    NASA Astrophysics Data System (ADS)

    Trassinelli, M.; Biri, S.; Boucard, S.; Covita, D. S.; Gotta, D.; Leoni, B.; Hirtl, A.; Indelicato, P.; Le Bigot, E.-O.; dos Santos, J. M. F.; Simons, L. M.; Stingelin, L.; Veloso, J. F. C. A.; Wasser, A.; Zmeskal, J.

    2005-03-01

    We present new results on the X-ray spectroscopy of multicharged argon, sulfur and chlorine obtained with the Electron Cyclotron Resonance Ion Trap (ECRIT) in operation at the Paul Scherrer Institut (Villigen, Switzerland). We used a Johann-type Bragg spectrometer with a spherically-bent crystal, with an energy resolution of about 0.4 eV. The ECRIT itself is of a hybrid type, with a superconducting split coil magnet, special iron inserts which provides the mirror field, and a permanent magnetic hexapole. The high frequency was provided by a 6.4 GHz microwave emitter. We obtained high intensity X-ray spectra of multicharged F-like to He-like argon, sulfur and chlorine with one 1s hole. In particular, we observed the 1s2s 3S1 → 1s2 1S0 M1 and 1s2p 3P2 → 1s2 1S0 M2 transitions in He-like argon, sulfur and chlorine with unprecedented statistics and resolution. The energies of the observed lines are being determined with good accuracy using the He-like M1 line as a reference. We surveyed the He-like M1 transition intensity as a function of the ECRIT working conditions. In particular we observed the M1 intensity dependency on the coil current and on the injected microwave power.

  19. Determination of halogens and sulfur in high-purity polyimide by IC after digestion by MIC.

    PubMed

    Krzyzaniak, Sindy R; Santos, Rafael F; Dalla Nora, Flavia M; Cruz, Sandra M; Flores, Erico M M; Mello, Paola A

    2016-09-01

    In this work, a method for sample preparation of high-purity polyimide was proposed for halogens and sulfur determination by ion chromatography (IC) with conductivity detection and, alternatively, by inductively coupled plasma mass spectrometry (ICP-MS). A relatively high polyimide mass (600mg) was completely digested by microwave-induced combustion (MIC) using 20bar of O2 and 50mmolL(-1) NH4OH as absorbing solution. These conditions allowed final solutions with low carbon content (<10mgL(-1)) and suitable pH for analysis by both IC and ICP-MS. The accuracy was evaluated using a certified reference material of polymer for Cl, Br and S and spike recovery experiments for all analytes. No statistical difference (t-test, 95% of confidence level) was observed between the results obtained for Cl, Br and S by IC after MIC and the certified values. In addition, spike recoveries obtained for F, Cl, Br, I and S ranged from 94% to 101%. The proposed method was suitable for polyimide decomposition for further determination of halogens and sulfur by IC and by ICP-MS (Br and I only). Taking into account the lack of methods and the difficulty of bringing this material into solution, MIC can be considered as a suitable alternative for the decomposition of polyimide for routine quality control of halogens and sulfur using IC or ICP-MS. PMID:27343595

  20. Determination of halogens and sulfur in high-purity polyimide by IC after digestion by MIC.

    PubMed

    Krzyzaniak, Sindy R; Santos, Rafael F; Dalla Nora, Flavia M; Cruz, Sandra M; Flores, Erico M M; Mello, Paola A

    2016-09-01

    In this work, a method for sample preparation of high-purity polyimide was proposed for halogens and sulfur determination by ion chromatography (IC) with conductivity detection and, alternatively, by inductively coupled plasma mass spectrometry (ICP-MS). A relatively high polyimide mass (600mg) was completely digested by microwave-induced combustion (MIC) using 20bar of O2 and 50mmolL(-1) NH4OH as absorbing solution. These conditions allowed final solutions with low carbon content (<10mgL(-1)) and suitable pH for analysis by both IC and ICP-MS. The accuracy was evaluated using a certified reference material of polymer for Cl, Br and S and spike recovery experiments for all analytes. No statistical difference (t-test, 95% of confidence level) was observed between the results obtained for Cl, Br and S by IC after MIC and the certified values. In addition, spike recoveries obtained for F, Cl, Br, I and S ranged from 94% to 101%. The proposed method was suitable for polyimide decomposition for further determination of halogens and sulfur by IC and by ICP-MS (Br and I only). Taking into account the lack of methods and the difficulty of bringing this material into solution, MIC can be considered as a suitable alternative for the decomposition of polyimide for routine quality control of halogens and sulfur using IC or ICP-MS.

  1. Process for reducing the total sulfur content of a high CO/sub 2/-content feed gas

    SciTech Connect

    McNamara, H.J.; Schilk, J.A.

    1982-10-26

    In the process for reducing the total sulfur content of a high CO/sub 2/-content feed gas stream, the feed gas is first passed to an absorption column. The unabsorbed, high CO/sub 2/-content gas is then routed to a reduction step where it is combined with Claus offgases and the sulfur compounds are reduced to H/sub 2/S. The treated gas is then passed to a second absorption column and the unabsorbed gas is vented to the atmosphere. The fat solvent from both absorption columns is stripped in a common stripper and the stripped gas is passed to a Claus unit for conversion to elemental sulfur.

  2. Matrix effects of calcium on high-precision sulfur isotope measurement by multiple-collector inductively coupled plasma mass spectrometry.

    PubMed

    Liu, Chenhui; Bian, Xiao-Peng; Yang, Tao; Lin, An-Jun; Jiang, Shao-Yong

    2016-05-01

    Multiple-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) has been successfully applied in the rapid and high-precision measurement for sulfur isotope ratios in recent years. During the measurement, the presence of matrix elements would affect the instrumental mass bias for sulfur and these matrix-induced effects have aroused a lot of researchers' interest. However, these studies have placed more weight on highlighting the necessity for their proposed correction protocols (e.g., chemical purification and matrix-matching) while less attention on the key property of the matrix element gives rise to the matrix effects. In this study, four groups of sulfate solutions, which have different concentrations of sulfur (0.05-0.60mM) but a constant sequence of atomic calcium/sulfur ratios (0.1-50), are investigated under wet (solution) and dry (desolvation) plasma conditions to make a detailed evaluation on the matrix effects from calcium on sulfur isotope measurement. Based on a series of comparative analyses, we indicated that, the matrix effects of calcium on both measured sulfur isotope ratios and detected (32)S signal intensities are dependent mainly on the absolute calcium concentration rather than its relative concentration ratio to sulfur (i.e., atomic calcium/sulfur ratio). Also, for the same group of samples, the matrix effects of calcium under dry plasma condition are much more significant than that of wet plasma. This research affords the opportunity to realize direct and relatively precise sulfur isotope measurement for evaporite gypsum, and further provides some suggestions with regard to sulfur isotope analytical protocols for sedimentary pore water.

  3. Sulfur-oxidizing chemolithotrophic proteobacteria dominate the microbiota in high arctic thermal springs on Svalbard.

    PubMed

    Reigstad, Laila Johanne; Jorgensen, Steffen Leth; Lauritzen, Stein-Erik; Schleper, Christa; Urich, Tim

    2011-09-01

    The thermal springs Trollosen and Fisosen, located on the High Arctic archipelago Svalbard, discharge saline groundwaters rich in hydrogen sulfide and ammonium through a thick layer of permafrost. Large amounts of biomass that consist of filamentous microorganisms containing sulfur granules, as analyzed with energy dispersive X-ray analysis, were found in the outflow. Prokaryotic 16S rRNA gene libraries and quantitative polymerase chain reaction (qPCR) analyses reported bacteria of the γ- and ɛ-proteobacterial classes as the dominant organisms in the filaments and the planktonic fractions, closely related to known chemolithoautotrophic sulfur oxidizers (Thiotrix and Sulfurovum). Archaea comprised ∼1% of the microbial community, with the majority of sequences affiliated with the Thaumarchaeota. Archaeal and bacterial genes coding for a subunit of the enzyme ammonia monooxygenase (amoA) were detected, as well as 16S rRNA genes of Nitrospira, all of which is indicative of potential complete nitrification in both springs. 16S rRNA sequences related to methanogens and methanotrophs were detected as well. This study provides evidence that the microbial communities in Trollosen and Fisosen are sustained by chemolithotrophy, mainly through the oxidation of reduced sulfur compounds, and that ammonium and methane might be minor, additional sources of energy and carbon.

  4. SnO2 as a high-efficiency polysulfide trap in lithium-sulfur batteries.

    PubMed

    Liu, Jing; Yuan, Lixia; Yuan, Kai; Li, Zhen; Hao, Zhangxiang; Xiang, Jingwei; Huang, Yunhui

    2016-07-14

    The ithium-sulfur battery stands as one of the most promising successors of traditional lithium-ion batteries due to its super high theoretical energy density, but practical application still suffers from the shuttle effect arising from soluble intermediate polysulfides. Here, we report SnO2 as a chemical adsorbent for polysulfides. As an interlayer between the cathode and separator, SnO2 gives better results to prevent the polysulfides from diffusing to the lithium anode than as a modifier of the carbon matrix directly. The lithium-sulfur battery with an SnO2 interlayer delivers an initial reversible capacity of 996 mA h g(-1) and retains 832 mA h g(-1) at the 100(th) discharge at 0.5 C, with a fading rate of only 0.19% per cycle. The improvements benefit from the quasi-open space provided by the interlayer configuration for the diffused sulfur species, which can largely relieve the loss of active substances caused by the volume effect during the lithiation/delithiation process.

  5. SnO2 as a high-efficiency polysulfide trap in lithium-sulfur batteries.

    PubMed

    Liu, Jing; Yuan, Lixia; Yuan, Kai; Li, Zhen; Hao, Zhangxiang; Xiang, Jingwei; Huang, Yunhui

    2016-07-14

    The ithium-sulfur battery stands as one of the most promising successors of traditional lithium-ion batteries due to its super high theoretical energy density, but practical application still suffers from the shuttle effect arising from soluble intermediate polysulfides. Here, we report SnO2 as a chemical adsorbent for polysulfides. As an interlayer between the cathode and separator, SnO2 gives better results to prevent the polysulfides from diffusing to the lithium anode than as a modifier of the carbon matrix directly. The lithium-sulfur battery with an SnO2 interlayer delivers an initial reversible capacity of 996 mA h g(-1) and retains 832 mA h g(-1) at the 100(th) discharge at 0.5 C, with a fading rate of only 0.19% per cycle. The improvements benefit from the quasi-open space provided by the interlayer configuration for the diffused sulfur species, which can largely relieve the loss of active substances caused by the volume effect during the lithiation/delithiation process. PMID:27364768

  6. Corrosion-resistant coatings for high-temperature high-sulfur-activity applications. Final report

    SciTech Connect

    Selman, J.R.

    1994-02-01

    The research described in this report is intended to assistant in developing the technology for the production of molybdenum and molybdenum carbide coatings. These coatings have the potential to serve as an alternative to present methods of protecting metal parts at positive potential, of high-temperature sulfur or sulfide batteries. Two methods have been employed. In Task 1, Study of Molybdenum Carbide Electrodeposition from Oxide Based Molten Salts, dense, well-adherent molybdenum carbide coatings have been deposited on mild steel substrates by electrochemical deposition from a Na{sub 2}WO{sub 4}-K{sub 2}WO{sub 4} molten bath containing alkali molybdates and carbonates. Coatings with thicknesses up to 30 {mu}m have been prepared at cathodic current densities between 30 and 50 mA.cm{sup {minus}2} under air as ambient atmosphere. Addition of Na{sub 2}B{sub 4}O{sub 7} to the basic non-lithium bath composition causes significant quality and morphology improvements. It is shown that the initial stages of the molybdenum carbide electrodeposition can be described by a model involving instantaneous nucleation and 3-D diffusion-controlled growth. In Task 2, Preparation of Mo and Mo{sub 2}C by Plasma-Enhanced Chemical Vapor Deposition, using factorial experimental design, a series of experiments has been carried out to investigate the PECVD process with Mo(CO){sub 6} as a precursor. Information about the effects of the chamber pressure, saturator temperature, gas composition and gas flow rate was obtained by experiments. Elemental analysis of the thin film was carried out by Auger electron spectroscopy. Further investigations are being carried out on the basis of thermodynamics, heterogeneous kinetics, and mass transport, in conjunction with measurements of evaporation rate and analysis of the solid and gaseous phases.

  7. Bioconversion of High Concentrations of Hydrogen Sulfide to Elemental Sulfur in Airlift Bioreactor

    PubMed Central

    Abdel-Monaem Zytoon, Mohamed; Ahmad AlZahrani, Abdulraheem; Hamed Noweir, Madbuli; Ahmed El-Marakby, Fadia

    2014-01-01

    Several bioreactor systems are used for biological treatment of hydrogen sulfide. Among these, airlift bioreactors are promising for the bioconversion of hydrogen sulfide into elemental sulfur. The performance of airlift bioreactors is not adequately understood, particularly when directly fed with hydrogen sulfide gas. The objective of this paper is to investigate the performance of an airlift bioreactor fed with high concentrations of H2S with special emphasis on the effect of pH in combination with other factors such as H2S loading rate, oxygen availability, and sulfide accumulation. H2S inlet concentrations between 1,008 ppm and 31,215 ppm were applied and elimination capacities up to 113 g H2S m−3 h−1 were achieved in the airlift bioreactor under investigation at a pH range 6.5–8.5. Acidic pH values reduced the elimination capacity. Elemental sulfur recovery up to 95% was achieved under oxygen limited conditions (DO < 0.2 mg/L) and at higher pH values. The sulfur oxidizing bacteria in the bioreactor tolerated accumulated dissolved sulfide concentrations >500 mg/L at pH values 8.0–8.5, and near 100% removal efficiency was achieved. Overall, the resident microorganisms in the studied airlift bioreactor favored pH values in the alkaline range. The bioreactor performance in terms of elimination capacity and sulfur recovery was better at pH range 8–8.5. PMID:25147857

  8. Mesoporous TiO2 Nanocrystals/Graphene as an Efficient Sulfur Host Material for High-Performance Lithium-Sulfur Batteries.

    PubMed

    Li, Yuanyuan; Cai, Qifa; Wang, Lei; Li, Qingwei; Peng, Xiang; Gao, Biao; Huo, Kaifu; Chu, Paul K

    2016-09-14

    Rechargeable lithium-sulfur (Li-S) batteries are promising in high-energy storage due to the large specific energy density of about 2600 W h kg(-1). However, the low conductivity of sulfur and discharge products as well as polysulfide-shuttle effect between the cathode and anode hamper applications of Li-S batteries. Herein, we describe a novel and efficient S host material consisting of mesoporous TiO2 nanocrystals (NCs) fabricated in situ on reduced graphene oxide (rGO) for Li-S batteries. The TiO2@rGO hybrid can be loaded with 72 wt % sulfur. The strong chemisorption ability of the TiO2 NCs toward polysulfide combined with high electrical conductivity of rGO effectively localize the soluble polysulfide species within the cathode and facilitate electron and Li ions transport to/from the cathode materials. The sulfur-incorporated TiO2@rGO hybrid (S/TiO2@rGO) shows large capacities of 1116 and 917 mA h g(-1) at the current densities of 0.2 and 1 C (1 C = 1675 mA g(-1)) after 100 cycles, respectively. When the current density is increased 20 times from 0.2 to 4 C, 60% capacity is retained, thereby demonstrating good cycling stability and rate capability. The synergistic effects of TiO2 NCs toward effective chemisorption of polysulfides and conductive rGO with high electron mobility make a promising application of S/TiO2@rGO hybrid in high-performance Li-S batteries. PMID:27552961

  9. Mesoporous TiO2 Nanocrystals/Graphene as an Efficient Sulfur Host Material for High-Performance Lithium-Sulfur Batteries.

    PubMed

    Li, Yuanyuan; Cai, Qifa; Wang, Lei; Li, Qingwei; Peng, Xiang; Gao, Biao; Huo, Kaifu; Chu, Paul K

    2016-09-14

    Rechargeable lithium-sulfur (Li-S) batteries are promising in high-energy storage due to the large specific energy density of about 2600 W h kg(-1). However, the low conductivity of sulfur and discharge products as well as polysulfide-shuttle effect between the cathode and anode hamper applications of Li-S batteries. Herein, we describe a novel and efficient S host material consisting of mesoporous TiO2 nanocrystals (NCs) fabricated in situ on reduced graphene oxide (rGO) for Li-S batteries. The TiO2@rGO hybrid can be loaded with 72 wt % sulfur. The strong chemisorption ability of the TiO2 NCs toward polysulfide combined with high electrical conductivity of rGO effectively localize the soluble polysulfide species within the cathode and facilitate electron and Li ions transport to/from the cathode materials. The sulfur-incorporated TiO2@rGO hybrid (S/TiO2@rGO) shows large capacities of 1116 and 917 mA h g(-1) at the current densities of 0.2 and 1 C (1 C = 1675 mA g(-1)) after 100 cycles, respectively. When the current density is increased 20 times from 0.2 to 4 C, 60% capacity is retained, thereby demonstrating good cycling stability and rate capability. The synergistic effects of TiO2 NCs toward effective chemisorption of polysulfides and conductive rGO with high electron mobility make a promising application of S/TiO2@rGO hybrid in high-performance Li-S batteries.

  10. Sublimed (inorganic) sulfur ingestion. A cause of life-threatening metabolic acidosis with a high anion gap.

    PubMed

    Schwartz, S M; Carroll, H M; Scharschmidt, L A

    1986-07-01

    We describe a 66-year-old woman undergoing hemodialysis treatment who developed life-threatening metabolic acidosis (pH of 6.67) with a high anion gap (41 mEq/L [41 mmol/L]) and marked hyperkalemia (9.1 mEq/L [9.1 mmol/L]) after consuming sulfur. Because of an increasing number of patients with chronic renal failure and dialysis-dependent end-stage renal disease, as well as persistence of folk remedies using sulfur, recognition of the potential dangers of self-administered sulfur seems appropriate.

  11. In situ coating of Poly(3,4-ethylenedioxythiophene) on sulfur cathode for high performance lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Song, Jongchan; Noh, Hyungjun; Lee, Jinhong; Nah, In-Wook; Cho, Won-Il; Kim, Hee-Tak

    2016-11-01

    Polysulfide (PS) shuttle, which is one of the critical problems that need to be addressed for realizing lithium sulfur batteries, can be suppressed by confining PSs within microporous or mesoporous templates. However, PS dissolution through the external opening of the templates has to be further prevented. In this work, a poly (3,4-ethylenedioxythiophene) (PEDOT) layer is formed in situ on the CMK-3/S cathode by inducing the electro-oxidative polymerization of the EDOT monomer included in electrolytes during pre-charging. The PEDOT layer covering the external cathode surface functions as a PS blocking layer, which suppresses the PS shuttle and, thus, improves the cycling stability. The spectroscopic analysis indicates that the PEDOT layer reduces the decomposition of the electrolyte by preventing any reaction between the active PS species and electrolytes. Therefore, the in situ formation of the PS blocking layer from the electrolyte additive provides a simple and effective method to improve the cycling stability of lithium sulfur batteries.

  12. Oxygen and sulfur isotope fractionation during methane dependent sulfate reduction in high pressure continuous incubation studies

    NASA Astrophysics Data System (ADS)

    Deusner, C.; Brunner, B.; Holler, T.; Widdel, F.; Ferdelman, T. G.

    2009-12-01

    The anaerobic oxidation of methane (AOM) coupled to sulfate reduction in marine sediments is an important sink in the global methane budget. However, many aspects of methane dependent sulfate reduction are not fully understood. We developed a novel high pressure biotechnical system to simulate marine conditions with high concentrations of dissolved gases, e.g. at gas seeps and gas hydrate systems. The system allows for batch, fed-batch and continuous gas-phase free incubation. We employ this system to study the kinetics and isotope fractionation during AOM at varying methane partial pressures up to 10 MPa. We present the results of long-term continuous and fed-batch incubations with highly active naturally enriched biomass from microbial mats from the Black Sea. During these experiments the methane partial pressure was increased stepwise from 0.1 to 10 MPa. The methane dependent sulfate reduction rate increased from 0.1 mmol/l/d to 3.5 mmol/l/d resulting from the increase in methane concentration and microbial growth. Sulfate reduction was negligible in the absence of methane. The sulfur and oxygen isotope fractionation during sulfate reduction was strongly influenced by the concentration of dissolved methane. Sulfur isotope fractionation was highest at low methane concentrations, and lowest at high methane concentrations. Relative to sulfate reduction rates, oxygen isotope exchange between sulfate and water was highest at low methane concentrations, and lowest at high methane concentrations.

  13. Superconducting H5S2 phase in sulfur-hydrogen system under high-pressure

    PubMed Central

    Ishikawa, Takahiro; Nakanishi, Akitaka; Shimizu, Katsuya; Katayama-Yoshida, Hiroshi; Oda, Tatsuki; Suzuki, Naoshi

    2016-01-01

    Recently, hydrogen sulfide was experimentally found to show the high superconducting critical temperature (Tc) under high-pressure. The superconducting Tc shows 30–70 K in pressure range of 100–170 GPa (low-Tc phase) and increases to 203 K, which sets a record for the highest Tc in all materials, for the samples annealed by heating it to room temperature at pressures above 150 GPa (high-Tc phase). Here we present a solid H5S2 phase predicted as the low-Tc phase by the application of the genetic algorithm technique for crystal structure searching and first-principles calculations to sulfur-hydrogen system under high-pressure. The H5S2 phase is thermodynamically stabilized at 110 GPa, in which asymmetric hydrogen bonds are formed between H2S and H3S molecules. Calculated Tc values show 50–70 K in pressure range of 100–150 GPa within the harmonic approximation, which can reproduce the experimentally observed low-Tc phase. These findings give a new aspect of the excellent superconductivity in compressed sulfur-hydrogen system. PMID:26983593

  14. Superconducting H5S2 phase in sulfur-hydrogen system under high-pressure

    NASA Astrophysics Data System (ADS)

    Ishikawa, Takahiro; Nakanishi, Akitaka; Shimizu, Katsuya; Katayama-Yoshida, Hiroshi; Oda, Tatsuki; Suzuki, Naoshi

    2016-03-01

    Recently, hydrogen sulfide was experimentally found to show the high superconducting critical temperature (Tc) under high-pressure. The superconducting Tc shows 30–70 K in pressure range of 100–170 GPa (low-Tc phase) and increases to 203 K, which sets a record for the highest Tc in all materials, for the samples annealed by heating it to room temperature at pressures above 150 GPa (high-Tc phase). Here we present a solid H5S2 phase predicted as the low-Tc phase by the application of the genetic algorithm technique for crystal structure searching and first-principles calculations to sulfur-hydrogen system under high-pressure. The H5S2 phase is thermodynamically stabilized at 110 GPa, in which asymmetric hydrogen bonds are formed between H2S and H3S molecules. Calculated Tc values show 50–70 K in pressure range of 100–150 GPa within the harmonic approximation, which can reproduce the experimentally observed low-Tc phase. These findings give a new aspect of the excellent superconductivity in compressed sulfur-hydrogen system.

  15. Selenium and selenium-sulfur cathode materials for high-energy rechargeable magnesium batteries

    NASA Astrophysics Data System (ADS)

    Zhao-Karger, Zhirong; Lin, Xiu-Mei; Bonatto Minella, Christian; Wang, Di; Diemant, Thomas; Behm, R. Jürgen; Fichtner, Maximilian

    2016-08-01

    Magnesium (Mg) is an attractive metallic anode material for next-generation batteries owing to its inherent dendrite-free electrodeposition, high capacity and low cost. Here we report a new class of Mg batteries based on both elemental selenium (Se) and selenium-sulfur solid solution (SeS2) cathode materials. Elemental Se confined into a mesoporous carbon was used as a cathode material. Coupling the Se cathode with a metallic Mg anode in a non-nucleophilic electrolyte, the Se cathode delivered a high initial volumetric discharge capacity of 1689 mA h cm-3 and a reversible capacity of 480 mA h cm-3 was retained after 50 cycles at a high current density of 2 C. The mechanistic insights into the electrochemical conversion in Mg-Se batteries were investigated by microscopic and spectroscopic methods. The structural transformation of cyclic Se8 into chainlike Sen upon battery cycling was revealed by ex-situ Raman spectroscopy. In addition, the promising battery performance with a SeS2 cathode envisages the perspective of a series of SeSn cathode materials combining the benefits of both selenium and sulfur for high energy Mg batteries.

  16. A systematic approach to high and stable discharge capacity for scaling up the lithium-sulfur battery

    NASA Astrophysics Data System (ADS)

    Kaiser, Mohammad Rejaul; Wang, Jiazhao; Liang, Xin; Liu, Hua-Kun; Dou, Shi-Xue

    2015-04-01

    A systematic approach to improving the performance of the Li-S battery is presented, based on applying high energy ball milling to create a porous sulfur-carbon composite, insertion of a free-standing layer, and adoption of a new charging method. Surface area analysis and field emission scanning electron microscope imaging show that the ball-milled sulfur powder has a porous structure and very high specific surface area. A vacuum-filtrated single-walled carbon nanotube free-standing layer is inserted in between the sulfur cathode and the separator. It is believed that high-surface-area porous sulfur will help to increase the conductivity of the elemental sulfur due to better adhesion between the conducting carbon and the sulfur, while the free-standing layer will sequester longer chain polysulfides, which are responsible for the well-known shuttling phenomenon. By the combination of these methods, we have achieved excellent capacity and cycle life. Finally, a new charging method which will largely prevent the formation of longer chain polysulfides is also applied to increase the capacity retention. It is believed that with the combination of ball milling, the free-standing layer, and the new charging method, it is possible to commercialize the Li-S battery with better capacity and cycle life.

  17. High-rate lithium-sulfur batteries enabled by hierarchical porous carbons synthesized via ice templation

    NASA Astrophysics Data System (ADS)

    Sahore, Ritu; Estevez, Luis P.; Ramanujapuram, Anirudh; DiSalvo, Francis J.; Giannelis, Emmanuel P.

    2015-11-01

    We report the performance of a series of hierarchical porous carbons (HPCs) with extremely high surface areas of up to 2340 m2 g-1 with total pore volume of up to 3.8 cm3 g-1 as supports for sulfur for Li-S batteries. The hierarchical structure of the carbon originating from interconnected large mesopores (10-50 nm), small mesopores (2-10 nm) and micropores (<2 nm) makes the total available surface area highly accessible, resulting in excellent electrode kinetics. At high C-rates of 2 C and 5 C, large specific capacities of 647 mA h g-1 and 503 mA h g-1, respectively, were obtained after 200 cycles. In addition, we also systematically show that the cyclic stability is independent of the size of the pores sulfur is initially confined in, when LiNO3 is used as the electrolyte additive, indicating that capacity fade due to polysulfide shuttle is effectively eliminated and that it is not related to pore size anymore.

  18. Infrared detection of Criegee intermediates formed during the ozonolysis of β-pinene and their reactivity towards sulfur dioxide.

    PubMed

    Ahrens, Jennifer; Carlsson, Philip T M; Hertl, Nils; Olzmann, Matthias; Pfeifle, Mark; Wolf, J Lennard; Zeuch, Thomas

    2014-01-13

    Recently, direct kinetic experiments have shown that the oxidation of sulfur dioxide to sulfur trioxide by reaction with stabilized Criegee intermediates (CIs) is an important source of sulfuric acid in the atmosphere. So far, only small CIs, generated in photolysis experiments, have been directly detected. Herein, it is shown that large, stabilized CIs can be detected in the gas phase by FTIR spectroscopy during the ozonolysis of β-pinene. Their transient absorption bands between 930 and 830 cm(-1) appear only in the initial phase of the ozonolysis reaction when the scavenging of stabilized CIs by the reaction products is slow. The large CIs react with sulfur dioxide to give sulfur trioxide and nopinone with a yield exceeding 80%. Reactant consumption and product formation in time-resolved β-pinene ozonolysis experiments in the presence of sulfur dioxide have been kinetically modeled. The results suggest a fast reaction of sulfur dioxide with CIs arising from β-pinene ozonolysis.

  19. Determination of total sulfur concentrations in different types of vinegars using high resolution flame molecular absorption spectrometry.

    PubMed

    Ozbek, Nil; Akman, Suleyman

    2016-12-15

    Total sulfur concentrations in vinegars were determined using molecular absorption of carbon monosulfide (CS) determined with a high-resolution continuum source flame atomic absorption spectrometer. The molecular absorption of CS was measured at 258.056nm in an air-acetylene flame. Due to non-spectral interference, as well as the different sensitivities to some sulfur compounds, all sulfur species were oxidized to sulfate using a HNO3 and H2O2 mixture and the analyte addition technique was applied for quantification. The limit of detection (LOD) and limit of quantification (LOQ) were 11.6 and 38.6mgL(-1), respectively. The concentrations of sulfur in various vinegars ranged from ⩽LOD to 163.6mgL(-1). PMID:27451213

  20. Functional Organosulfide Electrolyte Promotes an Alternate Reaction Pathway to Achieve High Performance in Lithium-Sulfur Batteries.

    PubMed

    Chen, Shuru; Dai, Fang; Gordin, Mikhail L; Yu, Zhaoxin; Gao, Yue; Song, Jiangxuan; Wang, Donghai

    2016-03-18

    Lithium-sulfur (Li-S) batteries have recently received great attention because they promise to provide energy density far beyond current lithium ion batteries. Typically, Li-S batteries operate by conversion of sulfur to reversibly form different soluble lithium polysulfide intermediates and insoluble lithium sulfides through multistep redox reactions. Herein, we report a functional electrolyte system incorporating dimethyl disulfide as a co-solvent that enables a new electrochemical reduction pathway for sulfur cathodes. This pathway uses soluble dimethyl polysulfides and lithium organosulfides as intermediates and products, which can boost cell capacity and lead to improved discharge-charge reversibility and cycling performance of sulfur cathodes. This electrolyte system can potentially enable Li-S batteries to achieve high energy density.

  1. High Temperature Corrosion Problem of Boiler Components in presence of Sulfur and Alkali based Fuels

    NASA Astrophysics Data System (ADS)

    Ghosh, Debashis; Mitra, Swapan Kumar

    2011-04-01

    Material degradation and ageing is of particular concern for fossil fuel fired power plant components. New techniques/approaches have been explored in recent years for Residual Life assessment of aged components and material degradation due to different damage mechanism like creep, fatigue, corrosion and erosion etc. Apart from the creep, the high temperature corrosion problem in a fossil fuel fired boiler is a matter of great concern if the fuel contains sulfur, chlorine sodium, potassium and vanadium etc. This paper discusses the material degradation due to high temperature corrosion in different critical components of boiler like water wall, superheater and reheater tubes and also remedial measures to avoid the premature failure. This paper also high lights the Residual Life Assessment (RLA) methodology of the components based on high temperature fireside corrosion. of different critical components of boiler.

  2. Influence of sulfur-bearing polyatomic species on high precision measurements of Cu isotopic composition

    USGS Publications Warehouse

    Pribil, M.J.; Wanty, R.B.; Ridley, W.I.; Borrok, D.M.

    2010-01-01

    An increased interest in high precision Cu isotope ratio measurements using multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) has developed recently for various natural geologic systems and environmental applications, these typically contain high concentrations of sulfur, particularly in the form of sulfate (SO42-) and sulfide (S). For example, Cu, Fe, and Zn concentrations in acid mine drainage (AMD) can range from 100??g/L to greater than 50mg/L with sulfur species concentrations reaching greater than 1000mg/L. Routine separation of Cu, Fe and Zn from AMD, Cu-sulfide minerals and other geological matrices usually incorporates single anion exchange resin column chromatography for metal separation. During chromatographic separation, variable breakthrough of SO42- during anion exchange resin column chromatography into the Cu fractions was observed as a function of the initial sulfur to Cu ratio, column properties, and the sample matrix. SO42- present in the Cu fraction can form a polyatomic 32S-14N-16O-1H species causing a direct mass interference with 63Cu and producing artificially light ??65Cu values. Here we report the extent of the mass interference caused by SO42- breakthrough when measuring ??65Cu on natural samples and NIST SRM 976 Cu isotope spiked with SO42- after both single anion column chromatography and double anion column chromatography. A set of five 100??g/L Cu SRM 976 samples spiked with 500mg/L SO42- resulted in an average ??65Cu of -3.50?????5.42??? following single anion column separation with variable SO42- breakthrough but an average concentration of 770??g/L. Following double anion column separation, the average SO42-concentration of 13??g/L resulted in better precision and accuracy for the measured ??65Cu value of 0.01?????0.02??? relative to the expected 0??? for SRM 976. We conclude that attention to SO42- breakthrough on sulfur-rich samples is necessary for accurate and precise measurements of ??65Cu and may require

  3. Kinetics of the reaction between hydrogen and sulfur under high-temperature Claus furnace conditions

    SciTech Connect

    Dowling, N.I.; Hyne, J.B. ); Brown, D.M. )

    1990-12-01

    The reaction H{sub 2} + (1/2)S{sub 2} {r equilibrium}H{sub 2}S has been studied as a function of temperature and residence time over the ranges 602--1290{degrees}C and 0.03--1.5 s in the absence of a catalyst. This paper shows that the combination of H{sub 2} and elemental sulfur vapor under the high-temperature conditions typical of a Claus sulfur recovery unit proceeds via a reversible homogeneous gas-phase reaction that is first order in both H{sub 2} and sulfur concentration and follows the rate law {minus}d(H{sub 2})/dt = k{sub 1}(H{sub 2})(S{sub 2}) {minus} k{sub 2}(H{sub 2}S) with a second-order recombination rate constant k{sub 1} = 1 {minus} 1 {times} 10{sup 3} atm{sup {minus}1} s{sup {minus}1} (A{sub 1} = (4.3 {plus minus} 0.2) {times} 10{sup 6} atm{sup {minus}1} s{sup {minus}1}; {Delta}H{sub 1} = 26 {plus minus} 1 kcal/mol) and first-order decomposition rate constant k{sub 2} = 4 {times} 10{sup {minus}4} {minus} 70 s{sup {minus}1} (A{sub 2} = (3.6 {plus minus} 1) {times} 10{sup 8} s{sup {minus}1}; {Delta}H{sub 2} = 48 {plus minus} 1 kcal/mol) over the temperature range studied. These findings can be used to exploit opportunities in acid gas processing, such as effecting improved efficiencies for O{sub 2} usage in oxygen- blown Claus units and maximizing H{sub 2} content in the tail gas.

  4. Three-dimensional aluminum foam/carbon nanotube scaffolds as long- and short-range electron pathways with improved sulfur loading for high energy density lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Cheng, Xin-Bing; Peng, Hong-Jie; Huang, Jia-Qi; Zhu, Lin; Yang, Shu-Hui; Liu, Yuan; Zhang, Hua-Wei; Zhu, Wancheng; Wei, Fei; Zhang, Qiang

    2014-09-01

    Conductive carbon scaffolds are efficient and effective to build advanced carbon/sulfur composite cathodes for lithium-sulfur (Li-S) batteries. However, the areal sulfur loading is commonly less than 4.0 mg cm-2, which limits the energy density and practical application of Li-S cells. In this contribution, three-dimensional (3D) aluminum foam/carbon nanotube (CNT) scaffolds were applied as the current collectors to build long- and short-range electron pathways and provided enough space for high sulfur loading. The sulfur loading amount on the 3D current collectors ranged from 7.0 to 12.5 mg cm-2. A high initial discharge capacity of 6.02 mAh cm-2 (860 mAh g-1) was achieved on an electrode with an improved sulfur loading of 7.0 mg cm-2. Therefore, the combination of 3D long-range current collectors and short-range CNT conductive scaffold provides an efficient and effective route to make full use of sulfur with a very high sulfur loading amount in a Li-S cell.

  5. Sulfur isotope dynamics in two central european watersheds affected by high atmospheric deposition of SO x

    NASA Astrophysics Data System (ADS)

    Novák, Martin; Kirchner, James W.; Groscheová, Hana; Havel, Miroslav; Černý, Jiří; Krejčí, Radovan; Buzek, František

    2000-02-01

    Sulfur fluxes and δ34S values were determined in two acidified small watersheds located near the Czech-German border, Central Europe. Sulfur of sulfate aerosol in the broader region (mean δ 34S of 7.5‰ CDT) was isotopically heavier than sulfur of airborne SO 2 (mean δ 34S of 4.7‰). The annual atmospheric S deposition to the Jezeřı´ watershed decreased markedly in 1993, 1994, and 1995 (40, 33, and 29 kg/ ha · yr), reflecting reductions in industrial S emissions. Sulfur export from Jezeří via surface discharge was twice atmospheric inputs, and increased from 52 to 58 to 85 kg/ha · yr over the same three-year period. The δ 34S value of Jezeřı´ streamflow was 4.5 ± 0.3‰, intermediate between the average atmospheric deposition (5.4 ± 0.2‰) and soil S (4.0 ± 0.5‰), suggesting that the excess sulfate in runoff comes from release of S from the soil. Bedrock is not a plausible source of the excess S, because its S concentration is very low (<0.003 wt.%) and because its δ 34S value is too high (5.8‰) to be consistent with the δ 34S of runoff. A sulfur isotope mixing model indicated that release of soil S accounted for 64 ± 33% of sulfate S in Jezeřı´ discharge. Approximately 30% of total sulfate S in the discharge were organically cycled. At Načetı´n, the same sequence of δ34S IN > δ34S OUT > δ34S SOIL was observed. The seasonality found in atmospheric input (higher δ 34S in summer, lower δ 34S in winter) was preserved in shallow (<10 cm) soil water, but not in deeper soil water. δ 34S values of deeper (>10 cm) soil water (4.8 ± 0.2‰) were intermediate between those of atmospheric input (5.9 ± 0.3‰) and Nac̆etín soils (2.4 ± 0.1‰), again suggesting that remobilization of soil S accounts for a significant fraction (roughly 40 ± 10%) of the S in soil water at Načetı´n. The inventories of soil S at both of these sites are legacies of more intense atmospheric pollution during previous decades, and are large enough (740

  6. High-performance hollow sulfur nanostructured battery cathode through a scalable, room temperature, one-step, bottom-up approach

    PubMed Central

    Li, Weiyang; Zheng, Guangyuan; Yang, Yuan; Seh, Zhi Wei; Liu, Nian; Cui, Yi

    2013-01-01

    Sulfur is an exciting cathode material with high specific capacity of 1,673 mAh/g, more than five times the theoretical limits of its transition metal oxides counterpart. However, successful applications of sulfur cathode have been impeded by rapid capacity fading caused by multiple mechanisms, including large volume expansion during lithiation, dissolution of intermediate polysulfides, and low ionic/electronic conductivity. Tackling the sulfur cathode problems requires a multifaceted approach, which can simultaneously address the challenges mentioned above. Herein, we present a scalable, room temperature, one-step, bottom-up approach to fabricate monodisperse polymer (polyvinylpyrrolidone)-encapsulated hollow sulfur nanospheres for sulfur cathode, allowing unprecedented control over electrode design from nanoscale to macroscale. We demonstrate high specific discharge capacities at different current rates (1,179, 1,018, and 990 mAh/g at C/10, C/5, and C/2, respectively) and excellent capacity retention of 77.6% (at C/5) and 73.4% (at C/2) after 300 and 500 cycles, respectively. Over a long-term cycling of 1,000 cycles at C/2, a capacity decay as low as 0.046% per cycle and an average coulombic efficiency of 98.5% was achieved. In addition, a simple modification on the sulfur nanosphere surface with a layer of conducting polymer, poly(3,4-ethylenedioxythiophene), allows the sulfur cathode to achieve excellent high-rate capability, showing a high reversible capacity of 849 and 610 mAh/g at 2C and 4C, respectively. PMID:23589875

  7. High-pressure synthesis, long-term stability of single crystals of diboron trioxide, B2O3, and an empirical electronic polarizability of [3]B3+

    NASA Astrophysics Data System (ADS)

    Burianek, Manfred; Birkenstock, Johannes; Mair, Philipp; Kahlenberg, Volker; Medenbach, Olaf; Shannon, Robert D.; Fischer, Reinhard X.

    2016-07-01

    Single crystals of B2O3 are needed for the precise determination of the refractive indices used to calculate the electronic polarizability α of 3-coordinated boron. The α(B) values in turn are used to predict mean refractive indices of borate minerals. Since the contribution of boron to the total polarizability of a mineral is very low, the synthetic compound B2O3 represents an ideal model system because of its high molar content of boron. Millimeter-sized crystals were synthesized at 1 GPa in a piston-cylinder apparatus. The samples were heated above the liquidus (800 °C), subsequently cooled at 15 °C/h to 500 °C and finally quenched. The refractive indices were determined by the immersion method using a microrefractometer spindle stage. The refractive indices n o = 1.653 (3) and n e = 1.632 (3) correspond to a total polarizability for B2O3 of α = 4.877 Å3. These values were used to determine the electronic polarizability of boron of α(B) = 0.16 Å3. Although the surface of the B2O3 crystals was coated with a hydrous film immediately after being exposed to air, its bulk crystallinity is retained for a period of at least 2 months.

  8. A novel laminated separator with multi functions for high-rate dischargeable lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Cai, Wenlong; Li, Gaoran; He, Fan; Jin, Liming; Liu, Binhong; Li, Zhoupeng

    2015-06-01

    A novel high-rate dischargeable semi-solid Li-S battery without free liquid electrolyte is assembled using a multi-functional separator with a polysulfide shield. The polysulfide shield is composed of Li+-Nafion, polyethylene oxide, and super P carbon. Hierarchical porous carbon is used as a sulfur holder to anchor polysulfide and improve cathode conductivity. Unlike all-solid Li-S batteries, the resultant Li-S battery shows excellent performance in both rate capacity and cycleability. The sulfur lithiation capacity reaches 1330 mAh g-1 at 0.2 C (0.335 A g-1 of S) and 690 mAh g-1 (338 mAh g-1 of electrode materials) at 10 C (16.75 A g-1 of S). The cell with the fabricated separator (SNP/Celgard) showed very low capacity degradation rate of less than 0.1% per cycle at 1 C (a discharge current density of 1.675 A g-1).

  9. A low cost, high energy density and long cycle life potassium-sulfur battery for grid-scale energy storage

    SciTech Connect

    Lu, Xiaochuan; Bowden, Mark E.; Sprenkle, Vincent L.; Liu, Jun

    2015-08-15

    Alkali metal-sulfur batteries are attractive for energy storage applications because of their high energy density. Among the batteries, lithium-sulfur batteries typically use liquid in the battery electrolyte, which causes problems in both performance and safety. Sodium-sulfur batteries can use a solid electrolyte such as beta alumina but this requires a high operating temperature. Here we report a novel potassium-sulfur battery with K+-conducting beta-alumina as the electrolyte. Our studies indicate that liquid potassium exhibits much better wettability on the surface of beta-alumina compared to liquid sodium at lower temperatures. Based on this observation, we develop a potassium-sulfur battery that can operate at as low as 150°C with excellent performance. In particular, the battery shows excellent cycle life with negligible capacity fade in 1000 cycles because of the dense ceramic membrane. This study demonstrates a new battery with a high energy density, long cycle life, low cost and high safety, which is ideal for grid-scale energy storage.

  10. Sulfur removal from high-sulfur Illinois coal by low-temperature perchloroethylene (PCE) extraction. Final technical report, 1 September, 1992--31 August, 1993

    SciTech Connect

    Chou, M.I.M.; Lytle, J.M.; Ruch, R.R.; Kruse, C.W.; Chaven, C.; Hackley, K.C.; Hughes, R.E.; Harvey, R.D.; Frost, J.K.; Buchanan, D.H.; Stucki, J.W.; Huffman, G.P.; Huggins, F.E.

    1993-12-31

    The Midwest Ore Processing Co. (MWOPC) has reported a precombustion coal desulfurization process using perchloroethylene (PCE) at 120 C to remove up to 70% of the organic sulfur. The purposes of this research were to independently confirm and possibly to improve the organic sulfur removal from Illinois coals with the PCE desulfurization and to verify the ASTM forms-of-sulfur determination for evaluation of the process. An additional goal was to develop a dechlorination procedure to remove excess PCE from the PCE-treated coal. A laboratory scale operation of the MWOPC PCE desulfurization process was demonstrated, and a dechlorination procedure to remove excess PCE from the PCE-treated coal was developed. The authors have determined that PCE desulfurization removed mainly elemental sulfur from coal. The higher the level of coal oxidization, the larger the amount of elemental sulfur that is removed by PCE extraction. The increased elemental sulfur during short-term preoxidation is found to be pH dependent and is attributed to coal pyrite oxidation under acidic (pH < 2) conditions. The non-ASTM sulfur analyses confirmed the hypothesis that the elemental sulfur produced by oxidation of pyrite complicates the interpretation of analytical data for PCE process evaluations when only the ASTM forms-of-sulfur is used. When the ASTM method is used alone, the elemental sulfur removed during PCE desulfurization is counted as organic sulfur. A study using model compounds suggests that mild preoxidation treatment of coal described by MWOPC for removal of organic sulfur does not produce enough oxidized organic sulfur to account for the amounts of sulfur removal reported. Furthermore, when oxidation of coal-like organosulfur compounds does occur, the products are inconsistent with production of elemental sulfur, the product reported by MWOPC. Overall, it is demonstrated that the PCE process is not suitable for organic sulfur removal.

  11. Organic transformations catalyzed by methylrhenium trioxide

    SciTech Connect

    Zhu, Z.

    1995-11-01

    Methylrhenium trioxide (MTO), CH{sub 3}ReO{sub 3}, was first prepared in 1979. MTO forms stable or unstable adducts with electron-rich ligands, such as amines (quinuclidine, 1,4-diazabicyclo-octane, pyridine, aniline, 2,2{prime}-bipyridine), alkynes, olefins, 1,2-diols, catechols, hydrogen peroxide, water, thiophenols, 1,2-dithiols, triphenylphosphine, 2-aminophenols, 2-aminothiophenols, 8-hydroxyquinoline and halides (Cl-, Br-, I-). After coordination, different further reactions will occur for different reagents. Reactions described in this report include the dehydration of alcohols, direct amination of alcohols, activation of hydrogen peroxide, oxygen transfer, and decomposition of ethyl diazoacetate.

  12. Search for high-Tc conventional superconductivity at megabar pressures in the lithium-sulfur system

    NASA Astrophysics Data System (ADS)

    Kokail, Christian; Heil, Christoph; Boeri, Lilia

    2016-08-01

    Motivated by the recent report of superconductivity above 200 K in ultra-dense hydrogen sulfide, we search for high-TC conventional superconductivity in the phase diagram of the binary Li-S system, using ab initio methods for crystal structure prediction and linear response calculations for the electron-phonon coupling. We find that at pressures higher than 20 GPa, several new compositions, besides the known Li2S , are stabilized; many exhibit electride-like interstitial charge localization observed in other alkali-metal compounds. Of all predicted phases, only an fcc phase of Li3S , metastable before 640 GPa, exhibits a sizable TC, in contrast to what is observed in sulfur and phosphorus hydrides, where several stoichiometries lead to high TC. We attribute this difference to 2 s -2 p hybridization and avoided core overlap, and predict similar behavior for other alkali-metal compounds.

  13. High temperature superconductivity in sulfur hydride under ultrahigh pressure: A complex superconducting phase beyond conventional BCS

    NASA Astrophysics Data System (ADS)

    Bussmann-Holder, Annette; Köhler, Jürgen; Whangbo, M.-H.; Bianconi, Antonio; Simon, Arndt

    2016-05-01

    The recent report of superconductivity under high pressure at the record transition temperature of Tc =203 K in pressurized H2S has been identified as conventional in view of the observation of an isotope effect upon deuteration. Here it is demonstrated that conventional theories of superconductivity in the sense of BCS or Eliashberg formalisms cannot account for the pressure dependence of the isotope coefficient. The only way out of the dilemma is a multi-band approach of superconductivity where already small interband coupling suffices to achieve the high values of Tc together with the anomalous pressure dependent isotope coefficient. In addition, it is shown that anharmonicity of the hydrogen bonds vanishes under pressure whereas anharmonic phonon modes related to sulfur are still active.

  14. Phosphorous pentasulfide as a novel additive for high-performance lithium-sulfur batteries

    SciTech Connect

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

    2012-01-01

    Lithium-sulfur (Li-S) batteries suffer from rapid capacity decay and low energy efficiency because of the low solubility of lithium sulfide (Li2S) in organic solvents and the intrinsic polysulfide shuttle phenomenon. Here, we report a novel additive of phosphorus pentasulfide (P2S5) in organic electrolyte to boost the cycling performance of Li-S batteries. The function of the additive is two-fold: (1) P2S5 promotes the dissolution of Li2S and alleviates the loss of capacity caused by the precipitation of Li2S; and (2) P2S5 passivates the surface of lithium metal and therefore eliminates the polysulfide shuttle phenomenon. A Li-S test cell demonstrates high reversible capacity of 900-1350 mAh g-1 and high coulombic efficiency of 90% for 40 stable cycles at 0.1 C.

  15. Clean coal technology and emissions trading: Is there a future for high-sulfur coal under the Clean Air Act Amendments of 1990?

    SciTech Connect

    Bailey, K.A.; South, D.W.; McDermott, K.A. |

    1991-12-31

    The near-term and long-term fate of high-sulfur coal is linked to utility compliance plans, the evolution of emission allowance trading, state and federal regulation, and technological innovation. All of these factors will play an implicit role in the demand for high-sulfur coal. This paper will explore the potential impact that emissions trading will have on high-sulfur coal utilization by electric utilities. 28 refs., 6 figs., 4 tabs.

  16. Clean coal technology and emissions trading: Is there a future for high-sulfur coal under the Clean Air Act Amendments of 1990

    SciTech Connect

    Bailey, K.A.; South, D.W. ); McDermott, K.A. Illinois State Univ., Normal, IL )

    1991-01-01

    The near-term and long-term fate of high-sulfur coal is linked to utility compliance plans, the evolution of emission allowance trading, state and federal regulation, and technological innovation. All of these factors will play an implicit role in the demand for high-sulfur coal. This paper will explore the potential impact that emissions trading will have on high-sulfur coal utilization by electric utilities. 28 refs., 6 figs., 4 tabs.

  17. Aubrite basalt vitrophyres: High sulfur silicate melts and a snapshot of aubrite formation. [Abstract only

    NASA Technical Reports Server (NTRS)

    Fogel, R. A.

    1994-01-01

    Two aubrite basalt vitrophyre clasts have been found within AMNH thin sections from the Parsa EH3 chondrite and the Khor Temiki aubrite. Polished sections of the Parsa Aubrite Inclusion (PAI) and the Khor Temiki Inclusion (KTI) were studied by optical, electron probe microanalysis (EPMA), and scanning electron microscopy (SEM) techniques with broad-beam and low absorbed EPMA currents used to minimize glass volatile loss. Some data have previously been reported for PAI and KTI may possibly correlate to a previously reported inclusion in Khor Tiimiki. In polished sections, PAI and KTI are approximately equal 4 mm in diameter and contain a large volume of glass. The clasts have similar textural characteristics and are akin to lunar vitrophyre textures. The glasses have high alkali rhyodacitic compositions Al-though PAI is peraluminous, KTI is significantly peralkaline. Additionally, the glasses have elevated sulfur concentrations that are extremely high by geochemical standards. SEM examination for beam overlap of microscopic CaS, FeS, and (Mg, Mn, Fe) S inclusions showed no such contamination. Furthermore, homogeneity of glass S content and low FeO contents help rule out contamination. Materials research data show that under reducing conditions alumino-silicate melts can dissolve up to several weight percent sulfur in the absence of Fe. The high S and alkali contents, the lack of associated high shock features, and the rationalized phase equilibria suggest that PAI and KTI are igneous melting products of an E-chondrite-like source material. Although large-scale impact melting cannot totally be ruled out, the above observations eliminate the possibility of in-situ shock melting.

  18. Polyamidoamine Dendrimer-Based Binders for High-Loading Lithium-Sulfur Battery Cathodes

    SciTech Connect

    Bhattacharya, Priyanka; Nandasiri, Manjula I.; Lv, Dongping; Schwarz, Ashleigh M.; Darsell, Jens T.; Henderson, Wesley A.; Tomalia, Donald A.; Liu, Jun; Zhang, Jiguang; Xiao, Jie

    2016-01-01

    Lithium-sulfur (Li-S) batteries are regarded as one of the most promising candidates for next generation energy storage systems because of their ultra high theoretical specific energy. To realize the practical application of Li-S batteries, however, a high S active material loading is essential (>70 wt% in the carbon-sulfur (C-S) composite cathode and >2 mg cm-2 in the electrode). A critical challenge to achieving this high capacity in practical electrodes is the dissolution of the longer lithium polysulfide reaction intermediates in the electrolyte (resulting in loss of active material from the cathode and contamination of the anode due to the polysulfide shuttle mechanism). The binder material used for the cathode is therefore crucial as this is a key determinant of the bonding interactions between the active material (S) and electronic conducting support (C), as well as the maintenance of intimate contact between the electrode materials and current collector. The battery performance can thus be directly correlated with the choice of binder, but this has received only minimal attention in the relevant Li-S battery published literature. Here, we investigated the application of polyamidoamine (PAMAM) dendrimers as functional binders in Li-S batteries—a class of materials which has been unexplored for electrode design. By using dendrimers, it is demonstrated that high S loadings (>4 mg cm-2) can be easily achieved using "standard" (not specifically tailored) materials and simple processing methods. An exceptional electrochemical cycling performance was obtained (as compared to cathodes with conventional linear polymeric binders such as carboxymethyl cellulose (CMC) and styrene-butadiene rubber (SBR)) with >100 cycles and 85-98% capacity retention, thus demonstrating the significant utility of this new binder architecture which exhibits critical physicochemical properties and flexible nanoscale design parameters (CNDP's).

  19. Aqueous leaching on high sulfur sub-bituminous coals, in Assam, India

    SciTech Connect

    Bimala P. Baruah; Binoy K. Saikia; Prabhat Kotoky; P. Gangadhar Rao

    2006-08-15

    Aqueous leaching of high sulfur sub-bituminous coals from Ledo and Baragolai collieries of Makum coal fields, in Assam, India, has been investigated with respect to time at different temperatures. Leaching at 25{sup o}C up to 120 h showed that the physicochemical characteristics viz., conductivity, acidity, TDS, and SO{sub 4}-2 ions, increase with the increase in time of leaching. The generation of highly acidic leachates at 1-1.5 h (pH 2.5) and 2 h (pH 3.1) for Ledo and Baragolai coals was observed, respectively. However, it remains stable up to 120 h. The concentration of major, minor, and trace elements and their mobility along with the loss of pyritic sulfur or depyritization were also reported. The release of metals (Fe, Mg, Bi, Al, V, Cu, Cd, Ni, Pb, and Mn) above the regulatory levels during leaching was evidenced. Depyritization was found to be 79.8, 82.9, 84.7, and 89.7% for Ledo and 70.49, 73.77, 75.41, and 77.05% for Baragolai coal at 15, 25, 35, and 45 {sup o}C, respectively. A pseudo-first-order kinetic relationship with activation energies (E) of 8.1477 and 5.2378 kJ mol{sup -1} with frequency factors (A) of 8.8405 x 10{sup -4} and 2.6494 x 10{sup -4} dm{sup 3} mol{sup -1} s{sup -1} was attributed to aqueous oxidation of pyrites in Ledo and Baragolai coals, respectively. The X-ray diffraction analysis and Fourier transform infrared spectroscopy patterns indicate the presence of illite, {alpha}-quartz, hematite, chlorite, rutile, calcite, and albite as mineral phases. This investigation justifies the formation of acid mine drainage by weathering of pyrites from coal during the mining of high sulfur Makum coal fields, in Assam, India, and demonstrates one of the possible routes for its formation. 39 refs., 3 figs. 9 tabs.

  20. Porous nitrogen-doped carbon derived from silk fibroin protein encapsulating sulfur as a superior cathode material for high-performance lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Zhang, Jiawei; Cai, Yurong; Zhong, Qiwei; Lai, Dongzhi; Yao, Juming

    2015-10-01

    The features of a carbon substrate are crucial for the electrochemical performance of lithium-sulfur (Li-S) batteries. Nitrogen doping of carbon materials is assumed to play an important role in sulfur immobilisation. In this study, natural silk fibroin protein is used as a precursor of nitrogen-rich carbon to fabricate a novel, porous, nitrogen-doped carbon material through facile carbonisation and activation. Porous carbon, with a reversible capacity of 815 mA h g-1 at 0.2 C after 60 cycles, serves as the cathode material in Li-S batteries. Porous carbon retains a reversible capacity of 567 mA h g-1, which corresponds to a capacity retention of 98% at 1 C after 200 cycles. The promising electrochemical performance of porous carbon is attributed to its mesoporous structure, high specific surface area and nitrogen doping into the carbon skeleton. This study provides a general strategy to synthesise nitrogen-doped carbons with a high specific surface area, which is crucial to improve the energy density and electrochemical performance of Li-S batteries.

  1. Layer-by-Layer Assembled Architecture of Polyelectrolyte Multilayers and Graphene Sheets on Hollow Carbon Spheres/Sulfur Composite for High-Performance Lithium-Sulfur Batteries.

    PubMed

    Wu, Feng; Li, Jian; Su, Yuefeng; Wang, Jing; Yang, Wen; Li, Ning; Chen, Lai; Chen, Shi; Chen, Renjie; Bao, Liying

    2016-09-14

    In the present work, polyelectrolyte multilayers (PEMs) and graphene sheets are applied to sequentially coat on the surface of hollow carbon spheres/sulfur composite by a flexible layer-by-layer (LBL) self-assembly strategy. Owing to the strong electrostatic interactions between the opposite charged materials, the coating agents are very stable and the coating procedure is highly efficient. The LBL film shows prominent impact on the stability of the cathode by acting as not only a basic physical barrier, and more importantly, an ion-permselective film to block the polysulfides anions by Coulombic repulsion. Furthermore, the graphene sheets can help to stabilize the polyelectrolytes film and greatly reduce the inner resistance of the electrode by changing the transport of the electrons from a "point-to-point" mode to a more effective "plane-to-point'' mode. On the basis of the synergistic effect of the PEMs and graphene sheets, the fabricated composite electrode exhibits very stable cycling stability for over 200 cycles at 1 A g(-1), along with a high average Coulombic efficiency of 99%. With the advantages of rapid and controllable fabrication of the LBL coating film, the multifunctional architecture developed in this study should inspire the design of other lithium-sulfur cathodes with unique physical and chemical properties. PMID:27479273

  2. Porous nitrogen-doped carbon derived from silk fibroin protein encapsulating sulfur as a superior cathode material for high-performance lithium-sulfur batteries.

    PubMed

    Zhang, Jiawei; Cai, Yurong; Zhong, Qiwei; Lai, Dongzhi; Yao, Juming

    2015-11-14

    The features of a carbon substrate are crucial for the electrochemical performance of lithium-sulfur (Li-S) batteries. Nitrogen doping of carbon materials is assumed to play an important role in sulfur immobilisation. In this study, natural silk fibroin protein is used as a precursor of nitrogen-rich carbon to fabricate a novel, porous, nitrogen-doped carbon material through facile carbonisation and activation. Porous carbon, with a reversible capacity of 815 mA h g(-1) at 0.2 C after 60 cycles, serves as the cathode material in Li-S batteries. Porous carbon retains a reversible capacity of 567 mA h g(-1), which corresponds to a capacity retention of 98% at 1 C after 200 cycles. The promising electrochemical performance of porous carbon is attributed to its mesoporous structure, high specific surface area and nitrogen doping into the carbon skeleton. This study provides a general strategy to synthesise nitrogen-doped carbons with a high specific surface area, which is crucial to improve the energy density and electrochemical performance of Li-S batteries.

  3. One-step electrochemical synthesis of nitrogen and sulfur co-doped, high-quality graphene oxide.

    PubMed

    Parvez, Khaled; Rincón, Rosalba A; Weber, Nils-Eike; Cha, Kitty C; Venkataraman, Shyam S

    2016-04-28

    High-quality graphene oxide (GO) with high crystallinity and electrical conductivity as well as in situ doped with nitrogen and sulfur is obtained via the electrochemical exfoliation of graphite. Furthermore, iron incorporated GO sheets show promising catalytic activity and stable methanol tolerance durability when used as electrocatalysts for the oxygen reduction reaction.

  4. The Influence of High Seawater Fluxes on Sulfur Compositions of the Serpentinized Peridotites at the Lost City Hydrothermal Field

    NASA Astrophysics Data System (ADS)

    Delacour, A.; Frueh-Green, G. L.; Bernasconi, S. M.; Kelley, D. S.

    2005-12-01

    The discovery of the actively venting carbonate chimneys at the Lost City hydrothermal vent field (LCHF) on the Atlantis Massif (MAR 30°N) has stimulated great interest in the role of serpentinization in driving hydrothermal circulation in peridotite-hosted systems and in the biological communities that may be supported in these systems. The southern wall of the massif exposes serpentinized peridotites with interspersed gabbroic rocks that have undergone several phases of serpentinization, talc-metasomatism and carbonate veining related to the uplift history and to the formation of the LCHF. We present petrological and isotope data from the serpentinized peridotites and gabbros that provide constraints on the history of seawater-rock interaction, changes in oxygen and sulfur fugacities during serpentinization, and the role of serpentinization as a sink for seawater sulfur. Sr- and Nd-isotope analyses of the basement rocks of the Atlantis Massif show large, systematic changes towards seawater compositions and indicate high seawater fluxes during successive phases of serpentinization. The consequence of these high fluid-rock ratios is a change in the sulfur mineralogy and chemistry of the rocks. Most of the analyzed basement rocks show lower sulfide-sulfur and higher sulfate-sulfur contents compared to fertile mantle. Sulfate in the serpentinites is present as barite and various hydroxysulfates. The distinct absence of anhydrite provides important constraints on upper temperature limits of late-stage serpentinization and hydrothermal activity at the LCHF. The sulfates are dominated by seawater sulfur isotope signatures, which indicate that serpentinization is an important sink of seawater sulfur at the Atlantis Massif. A few samples with lower sulfur isotope compositions suggest an additional local contribution of sulfate produced by sulfide oxidation. Sulfide assemblages are dominated by pyrite, pentlandite, pyrrhotite in the serpentinites and by pyrite, pyrrhotite

  5. EPRI High-Sulfur Test Center: Wet flue gas desulfurization baseline limestone tests

    SciTech Connect

    Gray, S.M.; Burke, J.M.

    1990-10-01

    This report presents the results of the Baseline Limestone Test Program conducted at Electric Power Research Institute's (EPRI) High Sulfur Test Center (HSTC). The objective of this program was to characterize wet limestone FGD system performance as a function of basic FGD design and operating variables using the pilot system at the HSTC. The results from this program will be useful in optimizing existing wet limestone FGD systems, and will provide the foundation for more specific research to be conducted at the HSTC. The design and operating variables that were investigated include: inlet SO{sub 2} concentration, liquid-to-gas ratio, slurry pH and density, dissolved calcium concentration, reaction tank volume, limestone grind, and in-situ forced oxidation. Results illustrate the effect of these variables on SO{sub 2} removal efficiency, limestone utilization, sulfite oxidation, and the waste solids properties. 20 refs., 58 figs., 19 tabs.

  6. Hierarchical TiO2 spheres as highly efficient polysulfide host for lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Yang, Zhi-Zheng; Wang, Hui-Yuan; Lu, Lun; Wang, Cheng; Zhong, Xiao-Bin; Wang, Jin-Guo; Jiang, Qi-Chuan

    2016-03-01

    Hierarchical TiO2 micron spheres assembled by nano-plates were prepared through a facile hydrothermal route. Chemical tuning of the TiO2 through hydrogen reduction (H-TiO2) is shown to increase oxygen-vacancy density and thereby modifies the electronic properties. H-TiO2 spheres with a polar surface serve as the surface-bound intermediates for strong polysulfides binding. Under the restricting and recapturing effect, the sulfur cathode could deliver a high reversible capacity of 928.1 mA h g-1 after 50 charge-discharge cycles at a current density of 200 mA g-1. The H-TiO2 additive developed here is practical for restricting and recapturing the polysulfide from the electrolyte.

  7. Hierarchical TiO2 spheres as highly efficient polysulfide host for lithium-sulfur batteries

    PubMed Central

    Yang, Zhi-Zheng; Wang, Hui-Yuan; Lu, Lun; Wang, Cheng; Zhong, Xiao-Bin; Wang, Jin-Guo; Jiang, Qi-Chuan

    2016-01-01

    Hierarchical TiO2 micron spheres assembled by nano-plates were prepared through a facile hydrothermal route. Chemical tuning of the TiO2 through hydrogen reduction (H-TiO2) is shown to increase oxygen-vacancy density and thereby modifies the electronic properties. H-TiO2 spheres with a polar surface serve as the surface-bound intermediates for strong polysulfides binding. Under the restricting and recapturing effect, the sulfur cathode could deliver a high reversible capacity of 928.1 mA h g−1 after 50 charge-discharge cycles at a current density of 200 mA g−1. The H-TiO2 additive developed here is practical for restricting and recapturing the polysulfide from the electrolyte. PMID:26965058

  8. Metatranscriptomic analysis of a high-sulfide aquatic spring reveals insights into sulfur cycling and unexpected aerobic metabolism

    PubMed Central

    Elshahed, Mostafa S.; Najar, Fares Z.; Krumholz, Lee R.

    2015-01-01

    Zodletone spring is a sulfide-rich spring in southwestern Oklahoma characterized by shallow, microoxic, light-exposed spring water overlaying anoxic sediments. Previously, culture-independent 16S rRNA gene based diversity surveys have revealed that Zodletone spring source sediments harbor a highly diverse microbial community, with multiple lineages putatively involved in various sulfur-cycling processes. Here, we conducted a metatranscriptomic survey of microbial populations in Zodletone spring source sediments to characterize the relative prevalence and importance of putative phototrophic, chemolithotrophic, and heterotrophic microorganisms in the sulfur cycle, the identity of lineages actively involved in various sulfur cycling processes, and the interaction between sulfur cycling and other geochemical processes at the spring source. Sediment samples at the spring’s source were taken at three different times within a 24-h period for geochemical analyses and RNA sequencing. In depth mining of datasets for sulfur cycling transcripts revealed major sulfur cycling pathways and taxa involved, including an unexpected potential role of Actinobacteria in sulfide oxidation and thiosulfate transformation. Surprisingly, transcripts coding for the cyanobacterial Photosystem II D1 protein, methane monooxygenase, and terminal cytochrome oxidases were encountered, indicating that genes for oxygen production and aerobic modes of metabolism are actively being transcribed, despite below-detectable levels (<1 µM) of oxygen in source sediment. Results highlight transcripts involved in sulfur, methane, and oxygen cycles, propose that oxygenic photosynthesis could support aerobic methane and sulfide oxidation in anoxic sediments exposed to sunlight, and provide a viewpoint of microbial metabolic lifestyles under conditions similar to those seen during late Archaean and Proterozoic eons. PMID:26417542

  9. Metatranscriptomic analysis of a high-sulfide aquatic spring reveals insights into sulfur cycling and unexpected aerobic metabolism.

    PubMed

    Spain, Anne M; Elshahed, Mostafa S; Najar, Fares Z; Krumholz, Lee R

    2015-01-01

    Zodletone spring is a sulfide-rich spring in southwestern Oklahoma characterized by shallow, microoxic, light-exposed spring water overlaying anoxic sediments. Previously, culture-independent 16S rRNA gene based diversity surveys have revealed that Zodletone spring source sediments harbor a highly diverse microbial community, with multiple lineages putatively involved in various sulfur-cycling processes. Here, we conducted a metatranscriptomic survey of microbial populations in Zodletone spring source sediments to characterize the relative prevalence and importance of putative phototrophic, chemolithotrophic, and heterotrophic microorganisms in the sulfur cycle, the identity of lineages actively involved in various sulfur cycling processes, and the interaction between sulfur cycling and other geochemical processes at the spring source. Sediment samples at the spring's source were taken at three different times within a 24-h period for geochemical analyses and RNA sequencing. In depth mining of datasets for sulfur cycling transcripts revealed major sulfur cycling pathways and taxa involved, including an unexpected potential role of Actinobacteria in sulfide oxidation and thiosulfate transformation. Surprisingly, transcripts coding for the cyanobacterial Photosystem II D1 protein, methane monooxygenase, and terminal cytochrome oxidases were encountered, indicating that genes for oxygen production and aerobic modes of metabolism are actively being transcribed, despite below-detectable levels (<1 µM) of oxygen in source sediment. Results highlight transcripts involved in sulfur, methane, and oxygen cycles, propose that oxygenic photosynthesis could support aerobic methane and sulfide oxidation in anoxic sediments exposed to sunlight, and provide a viewpoint of microbial metabolic lifestyles under conditions similar to those seen during late Archaean and Proterozoic eons. PMID:26417542

  10. Conventional superconductivity at 203 kelvin at high pressures in the sulfur hydride system.

    PubMed

    Drozdov, A P; Eremets, M I; Troyan, I A; Ksenofontov, V; Shylin, S I

    2015-09-01

    A superconductor is a material that can conduct electricity without resistance below a superconducting transition temperature, Tc. The highest Tc that has been achieved to date is in the copper oxide system: 133 kelvin at ambient pressure and 164 kelvin at high pressures. As the nature of superconductivity in these materials is still not fully understood (they are not conventional superconductors), the prospects for achieving still higher transition temperatures by this route are not clear. In contrast, the Bardeen-Cooper-Schrieffer theory of conventional superconductivity gives a guide for achieving high Tc with no theoretical upper bound--all that is needed is a favourable combination of high-frequency phonons, strong electron-phonon coupling, and a high density of states. These conditions can in principle be fulfilled for metallic hydrogen and covalent compounds dominated by hydrogen, as hydrogen atoms provide the necessary high-frequency phonon modes as well as the strong electron-phonon coupling. Numerous calculations support this idea and have predicted transition temperatures in the range 50-235 kelvin for many hydrides, but only a moderate Tc of 17 kelvin has been observed experimentally. Here we investigate sulfur hydride, where a Tc of 80 kelvin has been predicted. We find that this system transforms to a metal at a pressure of approximately 90 gigapascals. On cooling, we see signatures of superconductivity: a sharp drop of the resistivity to zero and a decrease of the transition temperature with magnetic field, with magnetic susceptibility measurements confirming a Tc of 203 kelvin. Moreover, a pronounced isotope shift of Tc in sulfur deuteride is suggestive of an electron-phonon mechanism of superconductivity that is consistent with the Bardeen-Cooper-Schrieffer scenario. We argue that the phase responsible for high-Tc superconductivity in this system is likely to be H3S, formed from H2S by decomposition under pressure. These findings raise hope for the

  11. Cross-stacked carbon nanotube film as an additional built-in current collector and adsorption layer for high-performance lithium sulfur batteries

    NASA Astrophysics Data System (ADS)

    Sun, Li; Kong, Weibang; Li, Mengya; Wu, Hengcai; Jiang, Kaili; Li, Qunqing; Zhang, Yihe; Wang, Jiaping; Fan, Shoushan

    2016-02-01

    Cross-stacked carbon nanotube (CNT) film is proposed as an additional built-in current collector and adsorption layer in sulfur cathodes for advanced lithium sulfur (Li-S) batteries. On one hand, the CNT film with high conductivity, microstructural rough surface, high flexibility and mechanical durability retains stable and direct electronic contact with the sulfur cathode materials, therefore decreasing internal resistivity and suppressing polarization of the cathode. On the other hand, the highly porous structure and the high surface area of the CNT film provide abundant adsorption points to support and confine sulfur cathode materials, alleviate their aggregation and promote high sulfur utilization. Moreover, the lightweight and compact structure of the CNT film adds no extra weight or volume to the sulfur cathode, benefitting the improvement of energy densities. Based on these characteristics, the sulfur cathode with a 100-layer cross-stacked CNT film presents excellent rate performances with capacities of 986, 922 and 874 mAh g-1 at cycling rates of 0.2C, 0.5C and 1C for sulfur loading of 60 wt%, corresponding to an improvement of 52%, 109% and 146% compared to that without a CNT film. Promising cycling performances are also demonstrated, offering great potential for scaled-up production of sulfur cathodes for Li-S batteries.

  12. THE EFFECT OF COFIRING HIGH-SULFUR COAL WITH MUNICIPAL WASTE ON FORMATION OF POLYCHLORINATED DIBENZODIOXIN AND POLYCHLORINATED DIBENZOFURAN

    EPA Science Inventory

    The effect of co-firing minor amounts (5-10 wt%) of high sulfur coal with municipal refuse-derived fuel (RDF) on emissions of polychlorinated dibenzo-p-dioxin (PCDD) and polychlorinated dibenzofuran (PCDF) was studied under a range of operating conditions. Through use of 2x facto...

  13. Potential of elemental sulfur fertigation to reduce high soil pH for production of highbush blueberry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Blueberry is adapted to acidic soil conditions but is often planted in high pH soils by adding elemental sulfur (S) prior to planting. Two pot experiments were carried out in a glasshouse to determine the potential of applying elemental S by fertigation through a drip irrigation system. In the first...

  14. Radiative lifetimes and transition probabilities for electric-dipole delta n equals zero transitions in highly stripped sulfur ions

    NASA Technical Reports Server (NTRS)

    Pegg, D. J.; Elston, S. B.; Griffin, P. M.; Forester, J. P.; Thoe, R. S.; Peterson, R. S.; Sellin, I. A.; Hayden, H. C.

    1976-01-01

    The beam-foil time-of-flight method has been used to investigate radiative lifetimes and transition rates involving allowed intrashell transitions within the L shell of highly ionized sulfur. The results for these transitions, which can be particularly correlation-sensitive, are compared with current calculations based upon multiconfigurational models.

  15. Activated Li2S as a High-Performance Cathode for Rechargeable Lithium-Sulfur Batteries.

    PubMed

    Zu, Chenxi; Klein, Michael; Manthiram, Arumugam

    2014-11-20

    Lithium-sulfur (Li-S) batteries with a high theoretical energy density of ∼2500 Wh kg(-1) are considered as one promising rechargeable battery chemistry for next-generation energy storage. However, lithium-metal anode degradation remains a persistent problem causing safety concerns for Li-S batteries, hindering their practical utility. One possible strategy to circumvent the aforementioned problems is to use alternative, high-capacity, lithium-free anodes (e.g., Si, Sn, carbon) and a Li2S cathode. However, a large potential barrier was identified on the initial charge of insulating bulk Li2S particles, limiting the cell performance. In this work, the bulk Li2S particles were effectively activated with an electrolyte containing P2S5, resulting in a lowered initial charging voltage plateau. This permits the direct use of commercially available bulk Li2S particles as a high-capacity cathode for room-temperature, rechargeable Li-S batteries, significantly lowering the manufacturing cost of Li-S cells. PMID:26276482

  16. The Biosynthesis of Nitrogen-, Sulfur-, and High-carbon Chain-containing Sugars†

    PubMed Central

    Lin, Chia-I; McCarty, Reid M.; Liu, Hung-wen

    2013-01-01

    Carbohydrates serve many structural and functional roles in biology. While the majority of monosaccharides are characterized by the chemical composition: (CH2O)n, modifications including deoxygenation, C-alkylation, amination, O- and N-methylation, which are characteristic of many sugar appendages of secondary metabolites, are not uncommon. Interestingly, some sugar molecules are formed via modifications including amine oxidation, sulfur incorporation, and “high-carbon” chain attachment. Most of these unusual sugars have been identified over the past several decades as components of microbially produced natural products, although a few high-carbon sugars are also found in the lipooligosaccharides of the outer cell walls of Gram-negative bacteria. Despite their broad distribution in nature, these sugars are considered “rare” due to their relative scarcity. The biosynthetic steps that underlie their formation continue to perplex researchers to this day and many questions regarding key transformations remain unanswered. This review will focus on our current understanding of the biosynthesis of unusual sugars bearing oxidized amine substituents, thio-functional groups, and high-carbon chains. PMID:23348524

  17. Evidence of sulfur-bound reduced copper in bamboo exposed to high silicon and copper concentrations.

    PubMed

    Collin, Blanche; Doelsch, Emmanuel; Keller, Catherine; Cazevieille, Patrick; Tella, Marie; Chaurand, Perrine; Panfili, Frédéric; Hazemann, Jean-Louis; Meunier, Jean-Dominique

    2014-04-01

    We examined copper (Cu) absorption, distribution and toxicity and the role of a silicon (Si) supplementation in the bamboo Phyllostachys fastuosa. Bamboos were maintained in hydroponics for 4 months and submitted to two different Cu (1.5 and 100 μm Cu(2+)) and Si (0 and 1.1 mM) concentrations. Cu and Si partitioning and Cu speciation were investigated by chemical analysis, microscopic and spectroscopic techniques. Copper was present as Cu(I) and Cu(II) depending on plant parts. Bamboo mainly coped with high Cu exposure by: (i) high Cu sequestration in the root (ii) Cu(II) binding to amino and carboxyl ligands in roots, and (iii) Cu(I) complexation with both organic and inorganic sulfur ligands in stems and leaves. Silicon supplementation decreased the visible damage induced by high Cu exposure and modified Cu speciation in the leaves where a higher proportion of Cu was present as inorganic Cu(I)S compounds, which may be less toxic.

  18. Effects of high dietary sulfur on brain functions using evoked potentials technique.

    PubMed Central

    Olkowski, A A; Gooneratne, S R; Crichlow, E C; Rousseaux, C G; Christensen, D A

    1990-01-01

    Brain stem auditory-evoked response (BAER) is a noninvasive technique used for detecting neurophysiological abnormalities of the brain stem along the auditory pathway. Brain stem auditory-evoked response recordings were obtained from subcutaneous skin electrodes from two control sheep and 22 other sheep fed high sulfur (S) diets with low or high concentration of thiamine (B1), copper (Cu), and molybdenum (Mo). At least four peaks (I,II,III,IV) of varied amplitude were observed in all animals. Neurophysiological abnormalities due to decreased conductivity and/or excitability of nerve fibers along the auditory pathway were found on the BAER recordings of sheep fed high S diet. Abnormalities of peaks and interpeak latencies within BAER recordings were related to histopathological observations of brain stem lesions. Lesions in the areas of the cochlear nuclei and lateral lemniscus were seen in conjunction with altered BAER components. However, abnormalities in BAER recordings and lesions in the brain stem also occurred in the absence of overt clinical signs. Analysis of interpeak latencies between peaks I and IV revealed significant differences among dietary groups. Sheep given diets low in Cu, Mo, and B1 were affected most. Factorial analysis indicated B1 and interactions among Cu, Mo, and B1 as significant factors influencing interpeak latencies. PMID:2306659

  19. Bi2S3in-situ formed in molten S environment stabilized sulfur cathodes for high-performance lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Li, Xiaona; Liang, Jianwen; Lu, Yue; Hou, Zhiguo; Zhang, Wanqun; Zhu, Yongchun; Qian, Yitai

    2016-10-01

    S/Bi2S3/C composites have been prepared based on melt strategy at 280 °C starting from metallic bismuth (mp 271.3 °C), excess sulfur powder and porous carbon with different ratio. In the as-prepared composites, the in-situ formed Bi2S3 in molten S environment can homogeneously dispersed in S and carbon. Combining the physical confinement of porous carbon and chemical interaction of the in-situ formed Bi2S3, the dissolution of polysulfides has been well inhibited. Thus, the obtained S/Bi2S3/C composite exhibits good electrochemical performance, which could deliver capacity of ∼825 mAh g-1 at 0.5 C over 400 cycles, with 91% capacity retention and high Coulombic efficiency.

  20. A natural carbonized leaf as polysulfide diffusion inhibitor for high-performance lithium-sulfur battery cells.

    PubMed

    Chung, Sheng-Heng; Manthiram, Arumugam

    2014-06-01

    Attracted by the unique tissue and functions of leaves, a natural carbonized leaf (CL) is presented as a polysulfide diffusion inhibitor in lithium-sulfur (Li-S) batteries. The CL that is covered on the pure sulfur cathode effectively suppresses the polysulfide shuttling mechanism and enables the use of pure sulfur as the cathode. A low charge resistance and a high discharge capacity of 1320 mA h g(-1) arise from the improved cell conductivity due to the innately integral conductive carbon network of the CL. The unique microstructure of CL leads to a high discharge/charge efficiency of >98 %, low capacity fade of 0.18 % per cycle, and good long-term cyclability over 150 cycles. The structural gradient and the micro/mesoporous adsorption sites of CL effectively intercept/trap the migrating polysulfides and facilitate their reutilization. The green CL polysulfide diffusion inhibitor thus offers a viable approach for developing high-performance lithium-sulfur batteries.

  1. Arsenic Trioxide Negatively Affects Echinococcus granulosus

    PubMed Central

    Wang, Bo; Wang, Zhuo; Li, Fangfang; Xing, Guoqiang; Peng, Xinyu; Zhang, Shijie

    2015-01-01

    Spillage of cyst contents during surgery is the major cause of recurrences of hydatidosis, also called cystic echinococcosis (CE). Currently, many scolicidal agents are used for inactivation of the cyst contents. However, due to complications in the use of those agents, new and more-effective treatment options are urgently needed. The aim of this study was to investigate the in vitro efficacy of arsenic trioxide (ATO) against Echinococcus granulosus protoscolices. Protoscolices of E. granulosus were incubated in vitro with 2, 4, 6, and 8 μmol/liter ATO; viability of protoscolices was assessed daily by microscopic observation of movements and 0.1% eosin staining. A small sample from each culture was processed for scanning and transmission electron microscopy. ATO demonstrated a potent ability to kill protoscolices, suggesting that ATO may represent a new strategy in treating hydatid cyst echinococcosis. However, the in vivo efficacy and possible side effects of ATO need to be explored. PMID:26324279

  2. Mineral trioxide aggregate apexification: A novel approach

    PubMed Central

    Purra, Aamir Rashid; Ahangar, Fayaz Ahmed; Chadgal, Sachin; Farooq, Riyaz

    2016-01-01

    The treatment of choice for necrotic teeth with immature root is apexification, which is induction of apical closure to produce more favorable conditions for conventional root canal filling. The most commonly advocated medicament is calcium hydroxide although recently considerable interest has been expressed in the use of mineral trioxide aggregate (MTA). MTA offers the option of a two-visit apexification procedure so that the fragile tooth can be restored immediately. However, difficulty in placing the material in the wide apical area requires the use of an apical matrix. Materials such as collagen, calcium sulfate, and hydroxyapatite have been used for this purpose. This article describes the use of resorbable suture material to form the apical matrix which offers many advantages over the contemporary materials. PMID:27563191

  3. Mineral trioxide aggregate apexification: A novel approach.

    PubMed

    Purra, Aamir Rashid; Ahangar, Fayaz Ahmed; Chadgal, Sachin; Farooq, Riyaz

    2016-01-01

    The treatment of choice for necrotic teeth with immature root is apexification, which is induction of apical closure to produce more favorable conditions for conventional root canal filling. The most commonly advocated medicament is calcium hydroxide although recently considerable interest has been expressed in the use of mineral trioxide aggregate (MTA). MTA offers the option of a two-visit apexification procedure so that the fragile tooth can be restored immediately. However, difficulty in placing the material in the wide apical area requires the use of an apical matrix. Materials such as collagen, calcium sulfate, and hydroxyapatite have been used for this purpose. This article describes the use of resorbable suture material to form the apical matrix which offers many advantages over the contemporary materials. PMID:27563191

  4. Arsenic trioxide negatively affects Echinococcus granulosus.

    PubMed

    Wang, Bo; Jiang, Yufeng; Wang, Zhuo; Li, Fangfang; Xing, Guoqiang; Peng, Xinyu; Zhang, Shijie; Lv, Hailong

    2015-11-01

    Spillage of cyst contents during surgery is the major cause of recurrences of hydatidosis, also called cystic echinococcosis (CE). Currently, many scolicidal agents are used for inactivation of the cyst contents. However, due to complications in the use of those agents, new and more-effective treatment options are urgently needed. The aim of this study was to investigate the in vitro efficacy of arsenic trioxide (ATO) against Echinococcus granulosus protoscolices. Protoscolices of E. granulosus were incubated in vitro with 2, 4, 6, and 8 μmol/liter ATO; viability of protoscolices was assessed daily by microscopic observation of movements and 0.1% eosin staining. A small sample from each culture was processed for scanning and transmission electron microscopy. ATO demonstrated a potent ability to kill protoscolices, suggesting that ATO may represent a new strategy in treating hydatid cyst echinococcosis. However, the in vivo efficacy and possible side effects of ATO need to be explored.

  5. Characterization of fly ash from low-sulfur and high-sulfur coal sources: Partitioning of carbon and trace elements with particle size

    USGS Publications Warehouse

    Hower, J.C.; Trimble, A.S.; Eble, C.F.; Palmer, C.A.; Kolker, A.

    1999-01-01

    Fly ash samples were collected in November and December of 1994, from generating units at a Kentucky power station using high- and low-sulfur feed coals. The samples are part of a two-year study of the coal and coal combustion byproducts from the power station. The ashes were wet screened at 100, 200, 325, and 500 mesh (150, 75, 42, and 25 ??m, respectively). The size fractions were then dried, weighed, split for petrographic and chemical analysis, and analyzed for ash yield and carbon content. The low-sulfur "heavy side" and "light side" ashes each have a similar size distribution in the November samples. In contrast, the December fly ashes showed the trend observed in later months, the light-side ash being finer (over 20 % more ash in the -500 mesh [-25 ??m] fraction) than the heavy-side ash. Carbon tended to be concentrated in the coarse fractions in the December samples. The dominance of the -325 mesh (-42 ??m) fractions in the overall size analysis implies, though, that carbon in the fine sizes may be an important consideration in the utilization of the fly ash. Element partitioning follows several patterns. Volatile elements, such as Zn and As, are enriched in the finer sizes, particularly in fly ashes collected at cooler, light-side electrostatic precipitator (ESP) temperatures. The latter trend is a function of precipitation at the cooler-ESP temperatures and of increasing concentration with the increased surface area of the finest fraction. Mercury concentrations are higher in high-carbon fly ashes, suggesting Hg adsorption on the fly ash carbon. Ni and Cr are associated, in part, with the spinel minerals in the fly ash. Copyright ?? 1999 Taylor & Francis.

  6. Impact of free calcium oxide content of fly ash on dust and sulfur dioxide emissions in a lignite-fired power plant

    SciTech Connect

    Dimitrios Sotiropoulos; Andreas Georgakopoulos; Nestoras Kolovos

    2005-07-01

    Emitted pollutants from the Agios Dimitrios lignite-fired power plant in northern Greece show a very strong linear correlation with the free calcium oxide content of the lignite ash. Dust (fly ash) emissions are positively correlated to free calcium oxide content, whereas sulfur dioxide (SO{sub 2}) emissions are negatively correlated. As a result, at present, the Agios Dimitrios Power Plant operates very strictly within the legislative limits on atmospheric particulate emission. In the study reported, the factors to be considered in assessing the impact of lignite combustion on the environment are presented and evaluated statistically. The ash appears to have a remarkable SO{sub 2} natural dry scrubbing capability when the free calcium oxide content ranges between 4 and 7%. Precipitator operating problems attributable to high ash resistivity can be overcome by injecting sulfur trioxide to reduce the ash resistivity, with, of course, a probable increase in operating costs. 27 refs., 7 figs., 1 tab.

  7. Comparison of radiation shielding ratios of nano-sized bismuth trioxide and molybdenum

    NASA Astrophysics Data System (ADS)

    Cho, J. H.; Kim, M. S.; Rhim, J. D.

    2015-07-01

    In this study, radiation shielding fibers using non-hazardous nano-sized bismuth trioxide and molybdenum instead of lead were developed and evaluated. Among the elements with high densities and atomic numbers, non-hazardous elements such as bismuth trioxide and molybdenum were chosen as a shielding element. Then, bismuth trioxide (Bi2O3) with average particle size 1-500 µm was ball milled for 10 min to produce a powdered form of nanoparticles with average particle size of 10-100 nm. Bismuth trioxide nanoparticles were dispersed to make a colloidal suspension, followed by spreading and hardening onto one or two sides of fabric, to create the radiation shielding fabric. The thicknesses of the shielding sheets using nano-sized bismuth and molybdenum were 0.4 and 0.7 mm. According to the lead equivalent test of X-ray shielding products suggested by KS, the equivalent dose was measured, followed by calculation of the shielding rate. The shielding rate of bismuth with 0.4 mm thickness and at 50 kVp was 90.5%, which is comparable to lead of 0.082 mm thickness. The shielding rate of molybdenum was 51.89%%, which is comparable to lead of 0.034 mm. At a thickness of 0.7 mm, the shielding rate of bismuth was 98.73%, equivalent to 0.101 mm Pb, whereas the shielding rate of molybdenum was 74.68%, equivalent to 0.045 mm Pb. In conclusion, the radiation shielding fibers using nano-sized bismuth developed in this study are capable of reducing radiation exposure by X-ray and its low-dose scatter ray.

  8. HYBRID SULFUR CYCLE FLOWSHEETS FOR HYDROGEN PRODUCTION USING HIGH-TEMPERATURE GAS-COOLED REACTORS

    SciTech Connect

    Gorensek, M.

    2011-07-06

    Two hybrid sulfur (HyS) cycle process flowsheets intended for use with high-temperature gas-cooled reactors (HTGRs) are presented. The flowsheets were developed for the Next Generation Nuclear Plant (NGNP) program, and couple a proton exchange membrane (PEM) electrolyzer for the SO2-depolarized electrolysis step with a silicon carbide bayonet reactor for the high-temperature decomposition step. One presumes an HTGR reactor outlet temperature (ROT) of 950 C, the other 750 C. Performance was improved (over earlier flowsheets) by assuming that use of a more acid-tolerant PEM, like acid-doped poly[2,2'-(m-phenylene)-5,5'-bibenzimidazole] (PBI), instead of Nafion{reg_sign}, would allow higher anolyte acid concentrations. Lower ROT was accommodated by adding a direct contact exchange/quench column upstream from the bayonet reactor and dropping the decomposition pressure. Aspen Plus was used to develop material and energy balances. A net thermal efficiency of 44.0% to 47.6%, higher heating value basis is projected for the 950 C case, dropping to 39.9% for the 750 C case.

  9. A trilayer separator with dual function for high performance lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Song, Rensheng; Fang, Ruopian; Wen, Lei; Shi, Ying; Wang, Shaogang; Li, Feng

    2016-01-01

    In this article, we propose a trilayer graphene/polypropylene/Al2O3 (GPA) separator with dual function for high performance lithium-sulfur (Li-S) batteries. Graphene is coated on one side of polypropylene (PP) separator, which functions as a conductive layer and an electrolyte reservoir that allows for rapid electron and ion transport. Then Al2O3 particles are coated on the other side to further enhance thermal stability and safety of the graphene coated polypropylene (GCP) separator, which are touched with lithium metal anode in the Li-S battery. The GPA separator shows good thermal stability after heating at 157 °C for 10 min while both GCP and PP separators showing an obvious shrinkage about 10%. The initial discharge specific capacity of Li-S coin cell with a GPA separator could reach 1067.7 mAh g-1 at 0.2C. After 100 discharge/charge cycles, it can still deliver a reversible capacity of as high as 804.4 mAh g-1 with 75% capacity retention. The pouch cells further confirm that the trilayer design has great promise towards practical applications.

  10. Hydrogen production by photoautotrophic sulfur-deprived Chlamydomonas reinhardtii pre-grown and incubated under high light.

    PubMed

    Tolstygina, Irina V; Antal, Taras K; Kosourov, Sergey N; Krendeleva, Tatyana E; Rubin, Andrey B; Tsygankov, Anatoly A

    2009-03-01

    We have previously demonstrated that Chlamydomonas reinhardtii can produce hydrogen under strictly photoautotrophic conditions during sulfur deprivation [Tsygankov et al. (2006); Int J Hydrogen Energy 3:1574-1584]. The maximum hydrogen photoproduction was achieved by photoautotrophic cultures pre-grown under a low light regime (25 microE m(-2) s(-1)). We failed to establish sustained hydrogen production from cultures pre-grown under high light (100 microE m(-2) s(-1)). A new approach for sustained hydrogen production by these cultures is presented here. Assuming that stable and reproducible transition to anerobiosis as well as high starch accumulation are important for hydrogen production, the influence of light intensity and dissolved oxygen concentration during the oxygen evolving stage of sulfur deprivation were investigated in cultures pre-grown under high light. Results showed that light higher than 175 microE m(-2) s(-1) during sulfur deprivation induced reproducible transition to anerobiosis, although the total amount of starch accumulation and hydrogen production were insignificant. The potential PSII activity measured in the presence of an artificial electron acceptor (DCBQ) and an inhibitor of electron transport (DBMIB) did not change in cultures pre-grown under 20 microE m(-2) s(-1) and incubated under 150 microE m(-2) s(-1) during sulfur deprivation. In contrast, the potential PSII activity decreased in cultures pre-grown under 100 microE m(-2) s(-1) and incubated under 420 microE m(-2) s(-1). This indicates that cultures grown under higher light experience irreversible inhibition of PSII in addition to reversible down regulation. High dissolved O(2) content during the oxygen evolving stage of sulfur deprivation has a negative regulatory role on PSII activity. To increase hydrogen production by C. reinhardtii pre-grown under 100 microE m(-2) s(-1), cultures were incubated under elevated PFD and decreased oxygen pressure during the oxygen evolving stage

  11. Hydrogen production by photoautotrophic sulfur-deprived Chlamydomonas reinhardtii pre-grown and incubated under high light.

    PubMed

    Tolstygina, Irina V; Antal, Taras K; Kosourov, Sergey N; Krendeleva, Tatyana E; Rubin, Andrey B; Tsygankov, Anatoly A

    2009-03-01

    We have previously demonstrated that Chlamydomonas reinhardtii can produce hydrogen under strictly photoautotrophic conditions during sulfur deprivation [Tsygankov et al. (2006); Int J Hydrogen Energy 3:1574-1584]. The maximum hydrogen photoproduction was achieved by photoautotrophic cultures pre-grown under a low light regime (25 microE m(-2) s(-1)). We failed to establish sustained hydrogen production from cultures pre-grown under high light (100 microE m(-2) s(-1)). A new approach for sustained hydrogen production by these cultures is presented here. Assuming that stable and reproducible transition to anerobiosis as well as high starch accumulation are important for hydrogen production, the influence of light intensity and dissolved oxygen concentration during the oxygen evolving stage of sulfur deprivation were investigated in cultures pre-grown under high light. Results showed that light higher than 175 microE m(-2) s(-1) during sulfur deprivation induced reproducible transition to anerobiosis, although the total amount of starch accumulation and hydrogen production were insignificant. The potential PSII activity measured in the presence of an artificial electron acceptor (DCBQ) and an inhibitor of electron transport (DBMIB) did not change in cultures pre-grown under 20 microE m(-2) s(-1) and incubated under 150 microE m(-2) s(-1) during sulfur deprivation. In contrast, the potential PSII activity decreased in cultures pre-grown under 100 microE m(-2) s(-1) and incubated under 420 microE m(-2) s(-1). This indicates that cultures grown under higher light experience irreversible inhibition of PSII in addition to reversible down regulation. High dissolved O(2) content during the oxygen evolving stage of sulfur deprivation has a negative regulatory role on PSII activity. To increase hydrogen production by C. reinhardtii pre-grown under 100 microE m(-2) s(-1), cultures were incubated under elevated PFD and decreased oxygen pressure during the oxygen evolving stage

  12. Electrosprayed molybdenum trioxide aqueous solution and its application in organic photovoltaic cells.

    PubMed

    Suzuki, Katsumi; Fukuda, Takeshi; Liao, Yingjie

    2014-01-01

    A molybdenum trioxide thin film with smooth surface and uniform thickness was successfully achieved by an electrospray deposition method using an aqueous solution with a drastically low concentration of 0.05 wt%. Previous papers demonstrated that an additive solvent technique is useful for depositing the thin film by the electrospray deposition, and the high vapor pressure and a low surface tension of an additive solvent were found to be important factors. As a result, the smooth molybdenum trioxide thin film was obtained when the acetonitrile was used as the additive solvent. Furthermore, the vapor pressure of acetone is much higher than that of aqueous solution, and this indicates that the acetone is easily evaporated after spraying from the glass capillary. By optimizing a concentration of acetone in the molybdenum aqueous solution, a minimum root mean square roughness of the MoO3 thin film became 3.7 nm. In addition, an organic photovoltaic cell was also demonstrated using the molybdenum trioxide as a hole transport layer. Highest photoconversion efficiency was 1.72%, a value comparable to that using conventional thermal evaporation process even though the aqueous solution was used for the solution process. The photovonversion efficiency was not an optimized value, and the higher value can be achieved by optimizing the coating condition of the active layer.

  13. Electrosprayed Molybdenum Trioxide Aqueous Solution and Its Application in Organic Photovoltaic Cells

    PubMed Central

    Suzuki, Katsumi; Fukuda, Takeshi; Liao, Yingjie

    2014-01-01

    A molybdenum trioxide thin film with smooth surface and uniform thickness was successfully achieved by an electrospray deposition method using an aqueous solution with a drastically low concentration of 0.05 wt%. Previous papers demonstrated that an additive solvent technique is useful for depositing the thin film by the electrospray deposition, and the high vapor pressure and a low surface tension of an additive solvent were found to be important factors. As a result, the smooth molybdenum trioxide thin film was obtained when the acetonitrile was used as the additive solvent. Furthermore, the vapor pressure of acetone is much higher than that of aqueous solution, and this indicates that the acetone is easily evaporated after spraying from the glass capillary. By optimizing a concentration of acetone in the molybdenum aqueous solution, a minimum root mean square roughness of the MoO3 thin film became 3.7 nm. In addition, an organic photovoltaic cell was also demonstrated using the molybdenum trioxide as a hole transport layer. Highest photoconversion efficiency was 1.72%, a value comparable to that using conventional thermal evaporation process even though the aqueous solution was used for the solution process. The photovonversion efficiency was not an optimized value, and the higher value can be achieved by optimizing the coating condition of the active layer. PMID:25148047

  14. Rapid and high-precision measurement of sulfur isotope and sulfur concentration in sediment pore water by multi-collector inductively coupled plasma mass spectrometry.

    PubMed

    Bian, Xiao-Peng; Yang, Tao; Lin, An-Jun; Jiang, Shao-Yong

    2015-01-01

    We have developed a technique for the rapid, precise and accurate determination of sulfur isotopes (δ(34)S) by MC-ICP-MS applicable to a range of sulfur-bearing solutions of different sulfur content. The 10 ppm Alfa-S solution (ammonium sulfate solution, working standard of the lab of the authors) was used to bracket other Alfa-S solutions of different concentrations and the measured δ(34)SV-CDT values of Alfa-S solutions deviate from the reference value to varying degrees (concentration effect). The stability of concentration effect has been verified and a correction curve has been constructed based on Alfa-S solutions to correct measured δ(34)SV-CDT values. The curve has been applied to AS solutions (dissolved ammonium sulfate from the lab of the authors) and pore water samples successfully, validating the reliability of our analytical method. This method also enables us to measure the sulfur concentration simultaneously when analyzing the sulfur isotope composition. There is a strong linear correlation (R(2)>0.999) between the sulfur concentrations and the intensity ratios of samples and the standard. We have constructed a regression curve based on Alfa-S solutions and this curve has been successfully used to determine sulfur concentrations of AS solutions and pore water samples. The analytical technique presented here enable rapid, precise and accurate S isotope measurement for a wide range of sulfur-bearing solutions - in particular for pore water samples with complex matrix and varying sulfur concentrations. Also, simultaneous measurement of sulfur concentrations is available.

  15. Highly-flexible 3D Li2S/graphene cathode for high-performance lithium sulfur batteries

    NASA Astrophysics Data System (ADS)

    He, Jiarui; Chen, Yuanfu; Lv, Weiqiang; Wen, Kechun; Li, Pingjian; Qi, Fei; Wang, Zegao; Zhang, Wanli; Li, Yanrong; Qin, Wu; He, Weidong

    2016-09-01

    Three-dimensional Li2S/graphene hierarchical architecture (3DLG) is synthesized with a facile infiltration method. Highly-crystalline Li2S nanoparticles are deposited homogenously into three-dimensional graphene foam (3DGF) network grown by chemical vapor deposition (CVD), resulting in 3DLG with high surface area, porosity, flexibility and conductivity. The 3DLG is employed as flexible, free-standing and binder-free cathode without metallic current collectors or conducting additives. Due to the unique structure, the 3DLG exhibits a high discharge capacity of 894.7 mAh g-1 at 0.1 C, a high capacity retention of 87.7% after 300 cycles at 0.2 C, and the high-rate capacity up to 4 C reaches 598.6 mAh g-1. The cyclic performance is record-breaking compared to the previous reports on free-standing graphene-Li2S cathodes. Flexible lithium-sulfur batteries based on the high-capacity 3DLG cathode have promising application potentials in flexible electronics, electrical vehicles, etc.

  16. Pie-like electrode design for high-energy density lithium-sulfur batteries.

    PubMed

    Li, Zhen; Zhang, Jin Tao; Chen, Yu Ming; Li, Ju; Lou, Xiong Wen David

    2015-01-01

    Owing to the overwhelming advantage in energy density, lithium-sulfur (Li-S) battery is a promising next-generation electrochemical energy storage system. Despite many efforts in pursuing long cycle life, relatively little emphasis has been placed on increasing the areal energy density. Herein, we have designed and developed a 'pie' structured electrode, which provides an excellent balance between gravimetric and areal energy densities. Combining lotus root-like multichannel carbon nanofibers 'filling' and amino-functionalized graphene 'crust', the free-standing paper electrode (S mass loading: 3.6 mg cm(-2)) delivers high specific capacity of 1,314 mAh g(-1) (4.7 mAh cm(-2)) at 0.1 C (0.6 mA cm(-2)) accompanied with good cycling stability. Moreover, the areal capacity can be further boosted to more than 8 mAh cm(-2) by stacking three layers of paper electrodes with S mass loading of 10.8 mg cm(-2). PMID:26608228

  17. Pie-like electrode design for high-energy density lithium-sulfur batteries.

    PubMed

    Li, Zhen; Zhang, Jin Tao; Chen, Yu Ming; Li, Ju; Lou, Xiong Wen David

    2015-11-26

    Owing to the overwhelming advantage in energy density, lithium-sulfur (Li-S) battery is a promising next-generation electrochemical energy storage system. Despite many efforts in pursuing long cycle life, relatively little emphasis has been placed on increasing the areal energy density. Herein, we have designed and developed a 'pie' structured electrode, which provides an excellent balance between gravimetric and areal energy densities. Combining lotus root-like multichannel carbon nanofibers 'filling' and amino-functionalized graphene 'crust', the free-standing paper electrode (S mass loading: 3.6 mg cm(-2)) delivers high specific capacity of 1,314 mAh g(-1) (4.7 mAh cm(-2)) at 0.1 C (0.6 mA cm(-2)) accompanied with good cycling stability. Moreover, the areal capacity can be further boosted to more than 8 mAh cm(-2) by stacking three layers of paper electrodes with S mass loading of 10.8 mg cm(-2).

  18. Compact, DC-electrical biased sulfur dioxide sensing elements for use at high temperatures

    SciTech Connect

    West, David L; Montgomery, Fred C; Armstrong, Beth L

    2012-01-01

    Fabrication and operation of sensing elements for the detection of sulfur dioxide (SO_2) at high temperature (800 900 ^oC) is reported. The sensing elements consisted of three (two oxide and one Pt) electrodes on yttria-stabilized zirconia substrates. To operate the elements, a DC current (typically about 0.1 mA) is driven between two of the electrodes and the voltage between one of these electrodes and the third electrode is used as the sensing signal. These sensing elements respond very strongly to SO_2, for example 2 ppm_V of SO_2 in a background of 7 vol% O_2, balance N_2 was found to produce a >10% change in the sensing signal, which could be easily detected. Sensing elements fabricated to be nominally identical were shown to yield qualitatively identical sensing behavior, and temperature, oxygen content, and flow were all found to strongly impact sensing performance. The impact of interferents, such as NO_x and CO, was evaluated and found to be relatively small in comparison to the SO_2 response. The sensing response, over a 1 month period, was very stable, with the ratio of the average change in sensing signal over one day to the average sensing signal magnitude being about 0.1%.

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

    SciTech Connect

    Delmas, R.; Servant, J.

    1982-12-20

    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.

  20. Pie-like electrode design for high-energy density lithium–sulfur batteries

    PubMed Central

    Li, Zhen; Zhang, Jin Tao; Chen, Yu Ming; Li, Ju; Lou, Xiong Wen (David)

    2015-01-01

    Owing to the overwhelming advantage in energy density, lithium–sulfur (Li–S) battery is a promising next-generation electrochemical energy storage system. Despite many efforts in pursuing long cycle life, relatively little emphasis has been placed on increasing the areal energy density. Herein, we have designed and developed a ‘pie' structured electrode, which provides an excellent balance between gravimetric and areal energy densities. Combining lotus root-like multichannel carbon nanofibers ‘filling' and amino-functionalized graphene ‘crust', the free-standing paper electrode (S mass loading: 3.6 mg cm−2) delivers high specific capacity of 1,314 mAh g−1 (4.7 mAh cm−2) at 0.1 C (0.6 mA cm−2) accompanied with good cycling stability. Moreover, the areal capacity can be further boosted to more than 8 mAh cm−2 by stacking three layers of paper electrodes with S mass loading of 10.8 mg cm−2. PMID:26608228

  1. Elemental Sulfur and Molybdenum Disulfide Composites for Li-S Batteries with Long Cycle Life and High-Rate Capability.

    PubMed

    Dirlam, Philip T; Park, Jungjin; Simmonds, Adam G; Domanik, Kenneth; Arrington, Clay B; Schaefer, Jennifer L; Oleshko, Vladimir P; Kleine, Tristan S; Char, Kookheon; Glass, Richard S; Soles, Christopher L; Kim, Chunjoong; Pinna, Nicola; Sung, Yung-Eun; Pyun, Jeffrey

    2016-06-01

    The practical implementation of Li-S technology has been hindered by short cycle life and poor rate capability owing to deleterious effects resulting from the varied solubilities of different Li polysulfide redox products. Here, we report the preparation and utilization of composites with a sulfur-rich matrix and molybdenum disulfide (MoS2) particulate inclusions as Li-S cathode materials with the capability to mitigate the dissolution of the Li polysulfide redox products via the MoS2 inclusions acting as "polysulfide anchors". In situ composite formation was completed via a facile, one-pot method with commercially available starting materials. The composites were afforded by first dispersing MoS2 directly in liquid elemental sulfur (S8) with sequential polymerization of the sulfur phase via thermal ring opening polymerization or copolymerization via inverse vulcanization. For the practical utility of this system to be highlighted, it was demonstrated that the composite formation methodology was amenable to larger scale processes with composites easily prepared in 100 g batches. Cathodes fabricated with the high sulfur content composites as the active material afforded Li-S cells that exhibited extended cycle lifetimes of up to 1000 cycles with low capacity decay (0.07% per cycle) and demonstrated exceptional rate capability with the delivery of reversible capacity up to 500 mAh/g at 5 C. PMID:27171646

  2. Elemental Sulfur and Molybdenum Disulfide Composites for Li-S Batteries with Long Cycle Life and High-Rate Capability.

    PubMed

    Dirlam, Philip T; Park, Jungjin; Simmonds, Adam G; Domanik, Kenneth; Arrington, Clay B; Schaefer, Jennifer L; Oleshko, Vladimir P; Kleine, Tristan S; Char, Kookheon; Glass, Richard S; Soles, Christopher L; Kim, Chunjoong; Pinna, Nicola; Sung, Yung-Eun; Pyun, Jeffrey

    2016-06-01

    The practical implementation of Li-S technology has been hindered by short cycle life and poor rate capability owing to deleterious effects resulting from the varied solubilities of different Li polysulfide redox products. Here, we report the preparation and utilization of composites with a sulfur-rich matrix and molybdenum disulfide (MoS2) particulate inclusions as Li-S cathode materials with the capability to mitigate the dissolution of the Li polysulfide redox products via the MoS2 inclusions acting as "polysulfide anchors". In situ composite formation was completed via a facile, one-pot method with commercially available starting materials. The composites were afforded by first dispersing MoS2 directly in liquid elemental sulfur (S8) with sequential polymerization of the sulfur phase via thermal ring opening polymerization or copolymerization via inverse vulcanization. For the practical utility of this system to be highlighted, it was demonstrated that the composite formation methodology was amenable to larger scale processes with composites easily prepared in 100 g batches. Cathodes fabricated with the high sulfur content composites as the active material afforded Li-S cells that exhibited extended cycle lifetimes of up to 1000 cycles with low capacity decay (0.07% per cycle) and demonstrated exceptional rate capability with the delivery of reversible capacity up to 500 mAh/g at 5 C.

  3. Determination of total sulfur at microgram per gram levels in geological materials by oxidation of sulfur into sulfate with in situ generation of bromine using isotope dilution high-resolution ICPMS.

    PubMed

    Makishima, A; Nakamura, E

    2001-06-01

    We have developed a new, simple, and accurate method for the determination of total sulfur at microgram per gram levels in milligram-sized silicate materials with isotope dilution high-resolution inductively coupled plasma mass spectrometry equipped with a flow injection system. In this method, sulfur can be quantitatively oxidized by bromine into sulfate with achievement of isotope equilibrium between the sample and spike. Detection limits for 32S+ and 34S+ in the ideal solution and silicate samples were 1 and 6 ng mL(-1) and 0.07 and 0.3 microg g(-1), respectively. The total blank was 46 ng, so that a 40-mg silicate sample containing 10 mirog g(-1) sulfur can be measured with a blank correction of < 10%. This total blank can be lowered to 8 ng if a low-blank air system is used for evaporations. To evaluate the applicability of this method, we analyzed not only silicate reference materials with sulfur content of 5.25-489 microg g(-1) and sample sizes of 13-40 mg but also the Allende meteorite with a sulfur content of 2%. The reproducibility for various rock types was < 9%, even though blank corrections in some samples of low sulfur content were up to 24%. This method is suitable for analyzing geological samples as well environmental samples such as soils, sediments, and water samples.

  4. Sulfur Mustard

    MedlinePlus

    ... the environment. Sulfur mustard was introduced in World War I as a chemical warfare agent. Historically it ... fatal. When sulfur mustard was used during World War I, it killed fewer than 5% of the ...

  5. DSRP, Direct Sulfur Production

    SciTech Connect

    Gangwal, S.K.; McMichael, W.J.; Agarwal, S.K.; Jang, B.L.; Howe, G.B.; Chen, D.H.; Hopper, J.R.

    1993-08-01

    Hot-gas desulfurization processes for IGCC and other advanced power applications utilize regenerable mixed-metal oxide sorbents to remove hydrogen sulfide (H{sub 2}S) from raw coal gas. Regeneration of these sorbents produces an off-gas typically containing I to 3 percent sulfur dioxide (SO{sub 2}). Production of elemental sulfur is a highly desirable option for the ultimate disposal of the SO{sub 2} content of this off-gas. Elemental sulfur, an essential industrial commodity, is easily stored and transported. As shown in Figure 1, the DSRP consists of two catalytic reactors, each followed by a sulfur condenser. Hot regenerator off-gas is mixed with a hot coal-gas slip stream and fed to the first DSRP reactor. Approximately 95 percent of the sulfur gas in the inlet stream of the first reactor is converted to elemental sulfur. The outlet gas of the first DSRP reactor is cooled, condensing out sulfur. The gas could be recycled after the Stage I condenser. Alteratively, by adjusting the proportion of coal gas to regenerator off-gas, the effluent composition of the first reactor can be controlled to produce an H{sub 2}S-to-SO{sub 2} ratio of 2 to 1 at 95 percent sulfur conversion. The cooled gas stream is then passed to the second DSRP reactor where 80 to 90 percent of the remaining sulfur compounds are converted to elemental sulfur via the modified Claus reaction at high pressure. The total efficiency of the two reactors for the conversion of sulfur compounds to elemental sulfur is projected to be about 99.5 percent.

  6. Sulfur dioxide oxidation induced mechanistic branching and particle formation during the ozonolysis of β-pinene and 2-butene.

    PubMed

    Carlsson, Philip T M; Keunecke, Claudia; Krüger, Bastian C; Maaß, Mona-C; Zeuch, Thomas

    2012-12-01

    Recent studies have suggested that the reaction of stabilised Criegee Intermediates (CIs) with sulfur dioxide (SO(2)), leading to the formation of a carbonyl compound and sulfur trioxide, is a relevant atmospheric source of sulfuric acid. Here, the significance of this pathway has been examined by studying the formation of gas phase products and aerosol during the ozonolysis of β-pinene and 2-butene in the presence of SO(2) in the pressure range of 10 to 1000 mbar. For β-pinene at atmospheric pressure, the addition of SO(2) suppresses the formation of the secondary ozonide and leads to highly increased nopinone yields. A complete consumption of SO(2) is observed at initial SO(2) concentrations below the yield of stabilised CIs. In experiments using 2-butene a significant consumption of SO(2) and additional formation of acetaldehyde are observed at 1 bar. A consistent kinetic simulation of the experimental findings is possible when a fast CI + SO(2) reaction rate in the range of recent direct measurements [Welz et al., Science, 2012, 335, 204] is used. For 2-butene the addition of SO(2) drastically increases the observed aerosol yields at higher pressures. Below 60 mbar the SO(2) oxidation induced particle formation becomes inefficient pointing to the critical role of collisional stabilisation for sulfuric acid controlled nucleation at low pressures.

  7. Mixed-Metal-Organic Framework with Effective Lewis Acidic Sites for Sulfur Confinement in High-Performance Lithium-Sulfur Batteries.

    PubMed

    Wang, Ziqi; Wang, Buxue; Yang, Yu; Cui, Yuanjing; Wang, Zhiyu; Chen, Banglin; Qian, Guodong

    2015-09-23

    The mixed-metal-organic framework approach and a representative zirconium-metalloporphyrin framework (MOF-525) have been developed to create novel sulfur hosts and Li-S batteries. The different local environments at the centers of the porphyrin moieties in a series of MMOFs-MOF-525(2H), MOF-525(FeCl), and MOF-525(Cu)-have led to their different behaviors for the confinement of sulfur and thus Li-S batteries. The unique structure of MOF-525(Cu) has enabled each Cu(2+) site to offer two Lewis acidic sites, featuring it as a very powerful MOF host for the inclusion of sulfur and polysulfides. The S@MOF-525(Cu) cathode has demonstrated the best performance among all reported sulfur/MOFs composite cathode materials, with a reversible capacity of about 700 mAh/g at 0.5 C after 200 cycles. PMID:26323942

  8. Economics of utilization of high sulfur coal resources - an integrated market approach

    USGS Publications Warehouse

    Bhagwat, S.B.

    1993-01-01

    Before the Clean Air Act Amendments of 1990, coal policies - especially coal research policies - were geared to find a solution to the sulfur emission problem. However, technologies to reduce sulfur emissions cannot be tailored for a single coal. A technology that will clean Illinois coal to compliance levels will do the same, or nearly the same, for most other types of coal. This paper will discuss an integrated approach to the analysis of the future of coals from different regions in the United States and its implications for coal-related policies by government and industry.

  9. Bioprocessing of High-sulfur Crudes Via Appliaction of Critical Fluid Biocatalysis

    SciTech Connect

    Ginosar, Daniel Michael; Bala, Greg Alan; Anderson, Raymond Paul; Fox, Sandra Lynn; Stanescue, Marina A.

    2002-05-01

    This experimental research project investigated protein-based biocatalysis in supercritical fluid solvents as an integrated process approach to catalyze the removal of sulfur atoms from crude oils and fuels. The work focused on the oxidation of model sulfur-containing compounds in supercritical reaction media and included three major tasks: microbiological induction experiments, proteincatalyzed biooxidation in supercritical solvents, and a work-in-kind cooperative research and development agreement (CRADA). This work demonstrated that the biooxidation reaction could be improved by an order-of-magnitude by carrying out the reaction in emulsions in supercritical fluids.

  10. Sulfur removal from high-sulfur Illinois coal by low-temperature perchloroethylene (PCE) extraction. [Quarterly] technical report, March 1, 1993--May 31, 1993

    SciTech Connect

    Chou, M.I.M.; Buchanan, D.H.; Stucki, J.W.

    1993-09-01

    The purposes of this project are: to independently confirm and possibly to improve the organic sulfur removal from Illinois coals with the PCE process developed by the Midwest Ore Processing Co. (MWOPC), to verify the forms-of-sulfur determination using the ASTM method for evaluation of the PCE process, and to develop a dechlorination procedure to remove excess PCE from the PCE-treated coal. The objectives for the second year are: to verify the possible effects of PCE treatment on coal-derived FeS{sub 2}, FeSO{sub 4}, and Fe{sub 2}(SO{sub 4}){sub 3} on ASTM coal analysis, to investigate the behavior of sulfur during oxidation and PCE desulfurization using the isotopically signatured coal sample, to investigate the effects of conditions and/or reagents on the oxidation of the organic-sulfur-model compounds, to evaluate the extended oxidation condition on the organic sulfur removal by PCE desulfurization, and to study other innovative pretreatment processes for the removal of organic sulfur from coal under mild conditions.

  11. Sulfur removal from high-sulfur Illinois coal by low-temperature perchloroethylene (PCE) extraction. Technical report, December 1, 1992--February 28, 1993

    SciTech Connect

    Chou, M.I.M.; Lytle, J.M.; Ruch, R.R.; Kruse, C.W.; Chaven, C.; Hackley, K.C.; Hughes, R.E.; Harvey, R.D.; Buchanan, D.H.; Stucki, J.W.; Huffman, G.; Huggins, F.E.; Ho, K.K.

    1993-05-01

    The purpose of this project are to independently confirm and possibly to improve the organic sulfur removal from Illinois coals with the PCE process developed by the Midwest Ore Processing Co.(MWOPC), to verify the forms-of-sulfur determination using the ASTM method for evaluation of the PCE process, and to develop a dechlorination procedure to remove excess PCE from the PCE-treated coal. The objectives for year-2 study are to verify the possible effect of PCE treatment on coal-derived FeS{sub 2}, FeSO{sub 4}, and Fe{sub 2}(SO{sub 4}){sub 3} on ASTM coal analysis, to investigate the behavior of sulfur during oxidation and PCE desulfurization using the isotopically signatured coal sample to investigate the proprietary reagent on the oxidation of the organic sulfur model compounds with and without additives, to evaluate this new oxidation on the organic sulfur removal by PCE desulfurization, and to study other innovative pretreatment processes for the removal of organic sulfur from coal under mild conditions. Oxidation study on the organosulfur model compounds alone was completed in first quarter. The oxidation reactions were repeated on the organosulfur model compounds with the presence of hydrocarbon additives. These additives are known to easily produce hydroperoxides during air oxidation. Analysis of the reaction products is in progress.

  12. Nanocasting hierarchical carbide-derived carbons in nanostructured opal assemblies for high-performance cathodes in lithium-sulfur batteries.

    PubMed

    Hoffmann, Claudia; Thieme, Sören; Brückner, Jan; Oschatz, Martin; Biemelt, Tim; Mondin, Giovanni; Althues, Holger; Kaskel, Stefan

    2014-12-23

    Silica nanospheres are used as templates for the generation of carbide-derived carbons with monodisperse spherical mesopores (d=20-40 nm) and microporous walls. The nanocasting approach with a polycarbosilane precursor and subsequent pyrolysis, followed by silica template removal and chlorine treatment, results in carbide-derived carbons DUT-86 (DUT=Dresden University of Technology) with remarkable textural characteristics, monodisperse, spherical mesopores tunable in diameter, and very high pore volumes up to 5.0 cm3 g(-1). Morphology replication allows these nanopores to be arranged in a nanostructured inverse opal-like structure. Specific surface areas are very high (2450 m2 g(-1)) due to the simultaneous presence of micropores. Testing DUT-86 samples as cathode materials in Li-S batteries reveals excellent performance, and tailoring of the pore size allows optimization of cell performance, especially the active center accessibility and sulfur utilization. The outstanding pore volumes allow sulfur loadings of 80 wt %, a value seldom achieved in composite cathodes, and initial capacities of 1165 mAh gsulfur(-1) are reached. After 100 cycle capacities of 860 mAh gsulfur(-1) are retained, rendering DUT-86 a high-performance sulfur host material. PMID:25435132

  13. Nanocasting hierarchical carbide-derived carbons in nanostructured opal assemblies for high-performance cathodes in lithium-sulfur batteries.

    PubMed

    Hoffmann, Claudia; Thieme, Sören; Brückner, Jan; Oschatz, Martin; Biemelt, Tim; Mondin, Giovanni; Althues, Holger; Kaskel, Stefan

    2014-12-23

    Silica nanospheres are used as templates for the generation of carbide-derived carbons with monodisperse spherical mesopores (d=20-40 nm) and microporous walls. The nanocasting approach with a polycarbosilane precursor and subsequent pyrolysis, followed by silica template removal and chlorine treatment, results in carbide-derived carbons DUT-86 (DUT=Dresden University of Technology) with remarkable textural characteristics, monodisperse, spherical mesopores tunable in diameter, and very high pore volumes up to 5.0 cm3 g(-1). Morphology replication allows these nanopores to be arranged in a nanostructured inverse opal-like structure. Specific surface areas are very high (2450 m2 g(-1)) due to the simultaneous presence of micropores. Testing DUT-86 samples as cathode materials in Li-S batteries reveals excellent performance, and tailoring of the pore size allows optimization of cell performance, especially the active center accessibility and sulfur utilization. The outstanding pore volumes allow sulfur loadings of 80 wt %, a value seldom achieved in composite cathodes, and initial capacities of 1165 mAh gsulfur(-1) are reached. After 100 cycle capacities of 860 mAh gsulfur(-1) are retained, rendering DUT-86 a high-performance sulfur host material.

  14. Development of a method for measuring the density of liquid sulfur at high pressures using the falling-sphere technique.

    PubMed

    Funakoshi, Ken-ichi; Nozawa, Akifumi

    2012-10-01

    We describe a new method for the in situ measurement of the density of a liquid at high pressure and high temperature using the falling-sphere technique. Combining synchrotron radiation X-ray radiography with a large-volume press, the newly developed falling-sphere method enables the determination of the density of a liquid at high pressure and high temperature based on Stokes' flow law. We applied this method to liquid sulfur and successfully obtained the density at pressures up to 9 GPa. Our method could be used for the determination of the densities of other liquid materials at higher static pressures than are currently possible.

  15. Understanding the Oxygen Vacancy in Tungsten Trioxide

    NASA Astrophysics Data System (ADS)

    Wang, Wennie; Janotti, Anderson; van de Walle, Chris G.

    2015-03-01

    Tungsten trioxide (WO3) has a variety of applications in gas sensors, photocatalysis, and smart windows. As an electrochromic BO3 perovskite, WO3 turns from transparent to blue upon doping. This color change is correlated with a drop in transmittance of near-IR radiation, and is used in smart windows for energy efficiency. In addition to monovalent species doping that modulates optical properties, oxygen deficiencies have been found to have a similar electrochromic effect. The influence of oxygen vacancies on electronic structure and how it corresponds to electrochromic behavior remains a topic of debate. In this work, we examine the oxygen vacancy in monoclinic WO3 and its influence on electronic structure using density functional theory with a hybrid functional. We investigate the relative stability of different charge states and its implications for electrical properties, such as conductivity and electrochromism. We find oxygen vacancies to be shallow donors, and explore similarities and differences with monovalent species doping. Finally, we compare our theoretical findings with experiment to elucidate how vacancies may contribute to electrochromic behavior. This work is supported by DOE and NSF.

  16. Catalyst for the reduction of sulfur dioxide to elemental sulfur

    DOEpatents

    Jin, Yun; Yu, Qiquan; Chang, Shih-Ger

    1996-01-01

    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.-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.

  17. A scalable hybrid separator for a high performance lithium-sulfur battery.

    PubMed

    Wang, Lina; Liu, Jingyuan; Haller, Servane; Wang, Yonggang; Xia, Yongyao

    2015-04-25

    A newly designed hybrid separator composed of a glassy fiber paper and a microporous membrane is effectively integrated into a Li-S battery. Superior cell performance up to 500 cycles is achieved even with commercially available pristine sulfur as cathode material. This fascinating study demonstrates a largely restrained polysulfides shuttle process toward practical Li-S battery application. PMID:25800005

  18. Molecular characterization of phytoplankton dissolved organic matter (DOM) and sulfur components using high resolution Orbitrap mass spectrometry.

    PubMed

    Mangal, Vaughn; Stock, Naomi L; Guéguen, Celine

    2016-03-01

    Orbitrap high resolution mass spectrometry (HRMS) with electrospray ionization in both positive and negative polarity was conducted on Suwannee River fulvic acid (SRFA), Pony Lake fulvic acid (PLFA) standards, and dissolved organic matter (DOM) released by freshwater phytoplankton (Scenedesmus obliquus, Euglena mutabilis, and Euglena gracilis). Three-dimensional van Krevelen diagrams expressing various oxygenation states of sulfur molecules and abundance plots of sulfur-containing species were constructed. Orbitrap HRMS analysis of SRFA found a high density of peaks in the lignin region (77 %) and low density of protein material (6.53 %), whereas for PLFA, 25 % of the total peaks were lignin related compared to 56 % of peaks in protein regions, comparable with other HRMS studies. Phytoplankton-derived DOM of S. obliquus, E. mutabilis, and E. gracilis was dominated by protein molecules at respective percentages of 36, 46, and 49 %, and is consistent with previous experiments examining phytoplankton-derived DOM composition. The normalized percentage of SO-containing compounds was determined among the three phytoplankton to be 56 % for Scenedesmus, 54 % for E. mutabilis, and 47 % for E. gracilis, suggesting variation between sulfur content in phytoplankton-derived DOM and differences in metal binding capacities. These results suggest the level of resolution by Orbitrap mass spectrometry is sufficient for preliminary characterization of phytoplankton DOM at an affordable cost relative to other HRMS techniques.

  19. Final Report - Management of High Sulfur HLW, VSL-13R2920-1, Rev. 0, dated 10/31/2013

    SciTech Connect

    Kruger, Albert A.; Gan, H.; Pegg, I. L.; Feng, Z.; Gan, H; Joseph, I.; Matlack, K. S.

    2013-11-13

    The present report describes results from a series of small-scale crucible tests to determine the extent of corrosion associated with sulfur containing HLW glasses and to develop a glass composition for a sulfur-rich HLW waste stream, which was then subjected to small-scale melter testing to determine the maximum acceptable sulfate loadings. In the present work, a new glass formulation was developed and tested for a projected Hanford HLW composition with sulfate concentrations high enough to limit waste loading. Testing was then performed on the DM10 melter system at successively higher waste loadings to determine the maximum waste loading without the formation of a separate sulfate salt phase. Small scale corrosion testing was also conducted using the glass developed in the present work, the glass developed in the initial phase of this work [26], and a high iron composition, all at maximum sulfur concentrations determined from melter testing, in order to assess the extent of Inconel 690 and MA758 corrosion at elevated sulfate contents.

  20. Mineral trioxide aggregate: a review of physical properties.

    PubMed

    Malhotra, Neeraj; Agarwal, Antara; Mala, Kundabala

    2013-02-01

    The purpose of this two-part series is to review the composition, properties, products, and clinical aspects of mineral trioxide aggregate (MTA) materials. Electronic search of scientific papers from January 1991 to May 2010 was accomplished using PubMed and MedLine search engines to include relevant scientific citations from the peer-reviewed journals published in English. MTA is a refined form of the parent compound, Portland cement (PC). It demonstrates a strong biocompatible nature owing to the high pH and its ability to form hydroxyapatite. MTA materials provide a better seal than traditional endodontic materials as observed in dye leakage, fluid filtration, protein leakage, and bacterial penetration leakage studies, and it has been recognized as a bioactive material. Currently a variety of MTA commercial products are available, including Proroot Gray MTA and White MTA both from DENTSPLY Tulsa Dental Specialties (www.DENTSPLY.com), and MTA Angelus (Angelus,www.angelus.ind.br). Although these materials are indicated for various dental uses/applications, long-term in-vivo clinical studies are still needed to claim the same. This first of this series highlights and discusses the composition, physical, and/or chemical properties of MTA. A subsequent article will offer an overview of the material aspect (commercial products) and clinical considerations for MTA materials.

  1. Arsenic trioxide rewires mantle cell lymphoma response to bortezomib.

    PubMed

    Zhao, Ling-Ling; Liu, Yuan-Fang; Peng, Li-Jun; Fei, Ai-Mei; Cui, Wen; Miao, Sheng-Chao; Hermine, Olivier; Gressin, Remy; Khochbin, Saadi; Chen, Sai-Juan; Wang, Jin; Mi, Jian-Qing

    2015-11-01

    Although most of the mantle cell lymphoma (MCL) patients initially responded well to bortezomib (BTZ), the dose-dependent toxicities have greatly limited the application of BTZ to MCL. To investigate the efficacy and mechanism of arsenic trioxide (ATO) with BTZ in inducing apoptosis of MCL cells, two MCL cell lines, along with primary cells from MCL patients (n = 4), were used. Additionally, the NOD-SCID mice xenograft model of Jeko-1 cells was established to study the anti-MCL mechanisms in an in vivo setting. ATO treatment highly improved BTZ capacity to inhibit proliferation and induce apoptosis of MCL cells. Furthermore, the interaction of Noxa and Mcl-1 leads Bak to release from Mcl-1 or from Bcl-xl, which could further activate Bak and Bax and then induce cell apoptosis. We also found that when lower doses of BTZ were used in combination with ATO, more effective proapoptotic effects in both the cell lines and the primary cells were obtained compared to the effects of BTZ used alone at higher doses. Simultaneously, the combination of these two drugs delayed the tumor growth in mice more effectively than BTZ alone. The cooperative anti-MCL effects of this combination therapy both in vitro and in vivo strongly provided a new strategy to the clinical treatment of MCL. PMID:26310857

  2. Liquid phase deposition synthesis of hexagonal molybdenum trioxide thin films

    SciTech Connect

    Deki, Shigehito; Beleke, Alexis Bienvenu; Kotani, Yuki; Mizuhata, Minoru

    2009-09-15

    Hexagonal molybdenum trioxide thin films with good crystallinity and high purity have been fabricated by the liquid phase deposition (LPD) technique using molybdic acid (H{sub 2}MoO{sub 4}) dissolved in 2.82% hydrofluoric acid (HF) and H{sub 3}BO{sub 3} as precursors. The crystal was found to belong to a hexagonal hydrate system MoO{sub 3}.nH{sub 2}O (napprox0.56). The unit cell lattice parameters are a=10.651 A, c=3.725 A and V=365.997 A{sup 3}. Scanning electron microscope (SEM) images of the as-deposited samples showed well-shaped hexagonal rods nuclei that grew and where the amount increased with increase in reaction time. X-ray photon electron spectroscopy (XPS) spectra showed a Gaussian shape of the doublet of Mo 3d core level, indicating the presence of Mo{sup 6+} oxidation state in the deposited films. The deposited films exhibited an electrochromic behavior by lithium intercalation and deintercalation, which resulted in coloration and bleaching of the film. Upon dehydration at about 450 deg. C, the hexagonal MoO{sub 3}.nH{sub 2}O was transformed into the thermodynamically stable orthorhombic phase. - Abstract: SEM photograph of typical h-MoO{sub 3}.nH{sub 2}O thin film nuclei obtained after 36 h at 40 deg. C by the LPD method. Display Omitted

  3. Photocatalysis and photoelectrochemical properties of tungsten trioxide nanostructured films.

    PubMed

    Lai, Chin Wei

    2014-01-01

    Tungsten trioxide (WO₃) possesses a small band gap energy of 2.4-2.8 eV and is responsive to both ultraviolet and visible light irradiation including strong absorption of the solar spectrum and stable physicochemical properties. Thus, controlled growth of one-dimensional (1D) WO₃ nanotubular structures with desired length, diameter, and wall thickness has gained significant interest. In the present study, 1D WO₃ nanotubes were successfully synthesized via electrochemical anodization of tungsten (W) foil in an electrolyte composed of 1 M of sodium sulphate (Na₂SO₄) and ammonium fluoride (NH₄F). The influence of NH₄F content on the formation mechanism of anodic WO₃ nanotubular structure was investigated in detail. An optimization of fluoride ions played a critical role in controlling the chemical dissolution reaction in the interface of W/WO₃. Based on the results obtained, a minimum of 0.7 wt% of NH₄F content was required for completing transformation from W foil to WO₃ nanotubular structure with an average diameter of 85 nm and length of 250 nm within 15 min of anodization time. In this case, high aspect ratio of WO₃ nanotubular structure is preferred because larger active surface area will be provided for better photocatalytic and photoelectrochemical (PEC) reactions.

  4. Mineral trioxide aggregate: a review of physical properties.

    PubMed

    Malhotra, Neeraj; Agarwal, Antara; Mala, Kundabala

    2013-02-01

    The purpose of this two-part series is to review the composition, properties, products, and clinical aspects of mineral trioxide aggregate (MTA) materials. Electronic search of scientific papers from January 1991 to May 2010 was accomplished using PubMed and MedLine search engines to include relevant scientific citations from the peer-reviewed journals published in English. MTA is a refined form of the parent compound, Portland cement (PC). It demonstrates a strong biocompatible nature owing to the high pH and its ability to form hydroxyapatite. MTA materials provide a better seal than traditional endodontic materials as observed in dye leakage, fluid filtration, protein leakage, and bacterial penetration leakage studies, and it has been recognized as a bioactive material. Currently a variety of MTA commercial products are available, including Proroot Gray MTA and White MTA both from DENTSPLY Tulsa Dental Specialties (www.DENTSPLY.com), and MTA Angelus (Angelus,www.angelus.ind.br). Although these materials are indicated for various dental uses/applications, long-term in-vivo clinical studies are still needed to claim the same. This first of this series highlights and discusses the composition, physical, and/or chemical properties of MTA. A subsequent article will offer an overview of the material aspect (commercial products) and clinical considerations for MTA materials. PMID:23627406

  5. Zeolites Remove Sulfur From Fuels

    NASA Technical Reports Server (NTRS)

    Voecks, Gerald E.; Sharma, Pramod K.

    1991-01-01

    Zeolites remove substantial amounts of sulfur compounds from diesel fuel under relatively mild conditions - atmospheric pressure below 300 degrees C. Extracts up to 60 percent of sulfur content of high-sulfur fuel. Applicable to petroleum refineries, natural-gas processors, electric powerplants, and chemical-processing plants. Method simpler and uses considerably lower pressure than current industrial method, hydro-desulfurization. Yields cleaner emissions from combustion of petroleum fuels, and protects catalysts from poisoning by sulfur.

  6. ADVANCED SULFUR CONTROL CONCEPTS

    SciTech Connect

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

    2003-01-01

    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).

  7. U.S. operating experience with wide plate spacing precipitators on high, medium, and low sulfur coals

    SciTech Connect

    Marker, B.L.; Dye, D.; Weaver, E.H.

    1995-12-31

    Wide plate spacing has become a widely used technology for electrostatic precipitators installed on coal fired boilers. As more operational time is gained with wide plate spacing precipitators, much has been learned concerning the operational and performance characteristics of these units. This information is extremely valuable to ensure their performance and operational integrity. This paper examines two installations of wide plate spacing precipitators through the project specifics, performance, and operating history of these facilities. The first facility examined is the precipitators at New York State Electric & Gas Milliken Station. This plant consists of two boilers, each rated at 160 MW. The boilers burn a medium to high sulfur Eastern U.S. coal. Each boiler has one wide plate spacing electrostatic precipitator with 16 inch plate spacing. The initially installed unit has been in service since July, 1993 and the second unit since December, 1994. The other plant examined is the precipitator installed on unit number five at City Utilities of Springfield James River Station. This boiler is rated at 105 MW. It has burned a medium sulfur Illinois coal and has recently switched to a low sulfur coal from the Western U.S. This unit has a 16 inch plate spacing electrostatic precipitator in series with 1970s vintage weighted wire electrostatic precipitators. This unit has been in service since April, 1994.

  8. Elemental sulfur recovery process

    DOEpatents

    Flytzani-Stephanopoulos, M.; Zhicheng Hu.

    1993-09-07

    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. 4 figures.

  9. Elemental sulfur recovery process

    DOEpatents

    Flytzani-Stephanopoulos, Maria; Hu, Zhicheng

    1993-01-01

    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.

  10. Reactions of connective tissue to amalgam, intermediate restorative material, mineral trioxide aggregate, and mineral trioxide aggregate mixed with chlorhexidine.

    PubMed

    Sumer, Mahmut; Muglali, Mehtap; Bodrumlu, Emre; Guvenc, Tolga

    2006-11-01

    The aim of this study was to histopathologically examine the biocompatibility of the high-copper amalgam, intermediate restorative material (IRM), mineral trioxide aggregate (MTA), and MTA mixed with chlorhexidine (CHX). This study was conducted to observe the rat subcutaneous connective tissue reaction to the implanted tubes filled with amalgam, IRM, MTA, and MTA mixed with CHX. The animals were sacrificed 15, 30, and 60 days after the implantation procedure. The implant sites were excised and prepared for histological evaluation. Sections of 5 to 6 microm thickness were cut by a microtome and stained with hemotoxylin eosin and examined under a light microscope. The inflammatory reactions were categorized as weak (none or few inflammatory cells < or =25 cells), moderate (>25 cells), and severe (a lot of inflammatory cells not to be counted, giant cells, and granulation tissue). Thickness of fibrous capsules measured five different areas by the digital imaging and the mean values were scored. Amalgam, IRM, and MTA mixed with CHX caused a weak inflammatory response on days 15, 30, and 60. MTA provoked an initial severe inflammatory response that subsided at the 30 and 60 day study period. A clear fibrous capsule was observed beginning from the 15 days in all of the groups. Within the limits of this study, amalgam, IRM, MTA, and MTA mixed with CHX materials were surrounded by fibrous connective tissue indicated that they were well tolerated by the tissues, therefore, MTA/CHX seemed to be biocompatible.

  11. High-temperature corrosion of iron in sulfur dioxide at low pressure

    SciTech Connect

    Gilewicz-Wolter, J.

    1996-08-01

    The composition and morphology of scales formed on iron in sulfur dioxide at 3 x 10{sup 3} Pa and 1073 K have been investigated by means of various X-ray techniques of analysis (XRD, EDAX, EPMA) and scanning electron microscopy (SEM). The transport phenomena have been studied using platinum markers and tracers. The scales were composed of a sulfide and oxide mixture and grew by outward diffusion of iron. There was also some inward transport of sulfur and oxygen which occured through the discontinuities of the scale. These oxidants, as well as those originating from the dissociation of the scale, take part in the formation of the inner scale layers in the metal-consumption zone. The initial stage of the process proceeds mainly by the reaction of iron with SO{sub 2} molecules.

  12. Biosorption and biodegradation of a sulfur dye in high-strength dyeing wastewater by Acidithiobacillus thiooxidans.

    PubMed

    Nguyen, Thai Anh; Fu, Chun-Chieh; Juang, Ruey-Shin

    2016-11-01

    The ability of the bacterial strain Acidithiobacillus thiooxidans to remove sulfur blue 15 (SB15) dye from water samples was examined. This bacterium could not only oxidize sulfur compounds to sulfuric acid but also promote the attachment of the cells to the surface of sulfidic particles, therefore serving as an efficient biosorbent. The biosorption isotherms were better described by the Langmuir equation than by the Freundlich or Dubinin-Radushkevich equation. Also, the biosorption process followed the pseudo-second-order kinetics. At pH 8.3 and SB15 concentrations up to 2000 mg L(-1) in the biomass/mineral salt solution, the dye removal and decolorization were 87.5% and 91.4%, respectively, following the biosorption process. Biodegradation was proposed as a subsequent process for the remaining dye (250-350 mg L(-1)). A central composite design was used to analyze independent variables in the response surface methodology study. Under the optimal conditions (i.e., initial dye concentration of 300 mg L(-1), initial biomass concentration of 1.0 g L(-1), initial pH of 11.7, and yeast extract dose of 60 mg L(-1)), up to 50% of SB15 was removed after 4 days of biodegradation. PMID:27486930

  13. Biosorption and biodegradation of a sulfur dye in high-strength dyeing wastewater by Acidithiobacillus thiooxidans.

    PubMed

    Nguyen, Thai Anh; Fu, Chun-Chieh; Juang, Ruey-Shin

    2016-11-01

    The ability of the bacterial strain Acidithiobacillus thiooxidans to remove sulfur blue 15 (SB15) dye from water samples was examined. This bacterium could not only oxidize sulfur compounds to sulfuric acid but also promote the attachment of the cells to the surface of sulfidic particles, therefore serving as an efficient biosorbent. The biosorption isotherms were better described by the Langmuir equation than by the Freundlich or Dubinin-Radushkevich equation. Also, the biosorption process followed the pseudo-second-order kinetics. At pH 8.3 and SB15 concentrations up to 2000 mg L(-1) in the biomass/mineral salt solution, the dye removal and decolorization were 87.5% and 91.4%, respectively, following the biosorption process. Biodegradation was proposed as a subsequent process for the remaining dye (250-350 mg L(-1)). A central composite design was used to analyze independent variables in the response surface methodology study. Under the optimal conditions (i.e., initial dye concentration of 300 mg L(-1), initial biomass concentration of 1.0 g L(-1), initial pH of 11.7, and yeast extract dose of 60 mg L(-1)), up to 50% of SB15 was removed after 4 days of biodegradation.

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

    NASA Astrophysics Data System (ADS)

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

    2012-07-01

    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 α lines was employed in measurements of the proton-induced K α 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.

  15. Determination of sulfur in bovine serum albumin and L-cysteine using high-resolution continuum source molecular absorption spectrometry of the CS molecule

    NASA Astrophysics Data System (ADS)

    Andrade-Carpente, Eva; Peña-Vázquez, Elena; Bermejo-Barrera, Pilar

    2016-08-01

    In this study, the content of sulfur in bovine serum albumin and L-cysteine was determined using high-resolution continuum source molecular absorption spectrometry of the CS molecule, generated in a reducing air-acetylene flame. Flame conditions (height above the burner, measurement time) were optimized using a 3.0% (v/v) sulfuric acid solution. A microwave lab station (Ethos Plus MW) was used for the digestion of both compounds. During the digestion step, sulfur was converted to sulfate previous to the determination. Good repeatability (4-10%) and analytical recovery (91-106%) was obtained.

  16. Regional river sulfur runoff

    NASA Astrophysics Data System (ADS)

    Husar, Rudolf B.; Husar, Janja Djukic

    1985-01-01

    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/m2/yr. However, high sulfur runoff density in excess of 3 g S/m2/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.

  17. Regional river sulfur runoff

    SciTech Connect

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

    1985-01-20

    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.

  18. Leaching of zinc sulfide by Thiobacillus ferrooxidans: Bacterial oxidation of the sulfur product layer increases the rate of zinc sulfide dissolution at high concentrations of ferrous ions

    SciTech Connect

    Fowler, T.A.; Crundwell, F.K.

    1999-12-01

    This paper reports the results of leaching experiments conducted with and without Thiobacillus ferroxidans at the same conditions in solution. The extent of leaching of ZnS with Bacteria is significantly higher than that without bacteria at high concentrations of ferrous ions. A porous layer of elemental sulfur is present on the surfaces of the chemically leached particles, which no sulfur is present on the surfaces of the bacterially leached particles. The analysis of the data using the shrinking-core model shows that the chemical leaching of ZnS is limited by the diffusion of ferrous ions through the sulfur product layer at high concentrations of ferrous ions. The analysis of the data shows that diffusion through the product layer does not limit the rate of dissolution when bacteria are present. This suggests that the action of T.ferroxidans in oxidizing the sulfur formed on the particle surface is to remove the barrier to diffusion by ferrous ions.

  19. Double-Shelled Nanocages with Cobalt Hydroxide Inner Shell and Layered Double Hydroxides Outer Shell as High-Efficiency Polysulfide Mediator for Lithium-Sulfur Batteries.

    PubMed

    Zhang, Jintao; Hu, Han; Li, Zhen; Lou, Xiong Wen David

    2016-03-14

    Lithium-sulfur (Li-S) batteries have been considered as a promising candidate for next-generation electrochemical energy-storage technologies because of their overwhelming advantages in energy density. Suppression of the polysulfide dissolution while maintaining a high sulfur utilization is the main challenge for Li-S batteries. Here, we have designed and synthesized double-shelled nanocages with two shells of cobalt hydroxide and layered double hydroxides (CH@LDH) as a conceptually new sulfur host for Li-S batteries. Specifically, the hollow CH@LDH polyhedra with complex shell structures not only maximize the advantages of hollow nanostructures for encapsulating a high content of sulfur (75 wt %), but also provide sufficient self-functionalized surfaces for chemically bonding with polysulfides to suppress their outward dissolution. When evaluated as cathode material for Li-S batteries, the CH@LDH/S composite shows a significantly improved electrochemical performance.

  20. Sulfur volcanoes on Io?

    NASA Technical Reports Server (NTRS)

    Greeley, R.; Fink, J. H.

    1984-01-01

    The unusual rheological properties of sulfur are discussed in order to determine the distinctive volcanic flow morphologies which indicate the presence of sulfur volcanoes on the Saturnian satellite Io. An analysis of high resolution Voyager imagery reveals three features which are considered to be possible sulfur volcanoes: Atar Patera, Daedalus Patera, and Kibero Patera. All three features are distinguished by circular-to-oval central masses surrounded by irregular widespread flows. The central zones of the features are interpreted to be domes formed of high temperature sulfur. To confirm the interpretations of the satellite data, molten sulfur was extruded in the laboratory at a temperature of 210 C on a flat surface sloping 0.5 deg to the left. At this temperature, the sulfur formed a viscous domelike mass over the event. As parts of the mass cooled to 170 C the viscosity decreased to a runny stage, forming breakout flows. It is concluded that a case can be made for sulfur volcanoes on Io sufficient to warrant further study, and it is recommended that the upcoming Galileo mission examine these phenomena.

  1. Polymerization of aniline in the interlayer space of molybdenum trioxide and its electrochemical properties

    SciTech Connect

    Li Yanping; Xiang Yixian; Dong Xiaowen; Xu Jiaqiang; Ruan Fei; Pan Qingyi

    2009-08-15

    Molybdenum trioxide/polyaniline (MoO{sub 3}/PANI) composite was prepared first by ion-exchange reaction between aniline (ANI) and dodecylamine (DDA) which was intercalated precursor, and then was formed under the polymerization of ANI within the interlayer space of MoO{sub 3} at 120 deg. C for 3 d in air. According to powder X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, infrared spectroscopy and electrochemical testing, MoO{sub 3}/PANI composite has layered structure, and its interlayer spacing is 1.127 nm. Moreover, it has high thermal stability with the compound and completes its weight loss at 751.9 deg. C. Electrochemical investigation shows that MoO{sub 3} is the major active substance in the MoO{sub 3}/PANI electrode, and MoO{sub 3}/PANI electrode demonstrates better conductivity and electrochemical activity than pure MoO{sub 3} electrode, attributed to the promotion of Li{sup +} and/or electron transport. In addition, the alternating current impedance proves that if the resistance of MoO{sub 3}/PANI electrode reduces apparently, the electrochemical activity will increase correspondingly, the same as the relationship between the ohmic resistance and the electrical conductivity. - Graphical abstract: Aniline (ANI) monomer was intercalated into the interlayer space of molybdenum trioxide (MoO{sub 3}) and heat-treated at 120 deg. C for 3 d in air, and then polymerized to form layered structure of molybdenum trioxide/polyaniline (MoO{sub 3}/PANI) composite. Its interlayer spacing of MoO{sub 3}/PANI composite is 1.127 nm.

  2. Organic Matter Sulfurization in the Cariaco Water Column Revealed by High-Sensitivity and Compound-Specific d34S Analyses.

    NASA Astrophysics Data System (ADS)

    Raven, M. R.; Sessions, A. L.; Adkins, J. F.; Thunell, R.

    2015-12-01

    Organic matter burial in marine sediments is a major process in the global carbon cycle, and enhanced organic matter burial is often associated with periods of global climatic and ecological change. Still, we have only a limited understanding of the processes that drive enhanced OM burial during oxygen-deficient conditions. Abiotic OM sulfurization has the potential to enhance the preservation of OM, but for this process to be significant it must compete with heterotrophic remineralization, most of which occurs before sinking particles reach the sea floor. We investigate the sources of sulfur to sinking particles in a modern marine basin using samples from the CARIACO fixed sediment trap time-series, applying recently developed methods for d34S analysis of small (≥20 nmol) sulfur pools and individual volatile organosulfur compounds. Relative to expectations for planktonic biomass, we find that sinking particles are both sulfur-rich and 34S-depleted. Higher apparent fluxes of 34S-depleted organic sulfur are associated with high OM export from the surface ocean, low terrestrial inputs, and high concentrations of both elemental S and the dominant non-polar organosulfur compound, C20 thiophene. We conclude that OM sulfurization is occurring in particles sinking through the Cariaco water column on timescales of days or less. Depending on the frequency of high OM export events, we estimate that this rapid sulfurization delivers roughly half of the total organic S present at 5 cm depth in underlying sediments. Accordingly, many OM-rich deposits in the geologic record may represent the products of water column sulfurization. This process provides a strong mechanistic feedback between oxygen deficiency and OM preservation.

  3. Sulfuric Acid on Europa

    NASA Technical Reports Server (NTRS)

    1999-01-01

    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.

  4. Investigation of the capacity retention mechanisms in novel composite sulfur copolymer-base cathodes for high-energy density Li-S batteries

    NASA Astrophysics Data System (ADS)

    Oleshko, Vladimir; Kim, Jenny; Masser, Kevin; Hudson, Steven; Soles, Christopher; Griebel, Jared; Chung, Woo Jin; Simmonds, Adam; Pyun, Jeffrey

    2013-03-01

    Utilization of the active cathode material in high-energy density Li-S batteries limited by the insulating nature of sulfur and losses in the form of insoluble polysulfides was improved by the use of 1,3-diisopropenylbenzene (DIB) copolymerized with molten sulfur. This approach termed, inverse vulcanization, transforms elemental sulfur into chemically stable processable copolymer forms with tunable thermomechanical properties. According to dielectric spectroscopy and dc conductivity measurements, composite sulfur-DIB copolymer cathodes exhibit a glassy-state beta relaxation related to short sulfur segments or to the DIB cross-linker. High-resolution AEM and FESEM studies down to the atomic scale reveal multiscale 3D-architectures created within the pristine and cycled composite cathodes with various contents of the electroactive copolymers. The morphology, structures, bonding and local compositional distributions of the constituents (sulfur, copolymers, aggregated conductive carbon nanoparticles) as well as extended pore structures and their transformations under cycling have been examined to provide insights into mechanisms of the enhanced capacity retention in the modified Li-S cells. NIST support under grant MML12-1053-N00

  5. Metabolism of arsenic trioxide in acute promyelocytic leukemia cells.

    PubMed

    Khaleghian, Ali; Ghaffari, Seyed H; Ahmadian, Shahin; Alimoghaddam, Kamran; Ghavamzadeh, Ardeshir

    2014-10-01

    Arsenic trioxide (As2O3) effectively induces complete clinical and molecular remissions in acute promyelocytic leukemia (APL) patients and triggers apoptosis in APL cells. The effect induced by As2O3 is also associated with extensive genomic-wide epigenetic changes with large-scale alterations in DNA methylation. We investigated the As2O3 metabolism in association with factors involved in the production of its methylated metabolites in APL-derived cell line, NB4. We used high performance liquid chromatography (HPLC) technique to detect As2O3 metabolites in NB4 cells. The effects of As2O3 on glutathione level, S-Adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH) levels were investigated. Also, we studied the expression levels of arsenic methyltransferase (AS3MT) and DNA methyltransferases (DNMT1, DNMT3a, and DNMT3b) by real-time PCR. Our results show that after As2O3 entry into the cell, it was converted into methylated metabolites, mono-methylarsenic (MMA) and dimethylarsenic (DMA). The glutathione (GSH) production was increased in parallel with the methylated metabolites formations. As2O3 treatment inhibited DNMTs (DNMT1, DNMT3a, and DNMT3b) in dose- and time-dependent manners. The SAH levels in As2O3-treated cells were increased; however, the SAM level was not affected. The present study shows that APL cell is capable of metabolizing As2O3. The continuous formation of intracellular methylated metabolites, the inhibition of DNMTs expression levels and the increase of SAH level by As2O3 biotransformation would probably affect the DNMTs-methylated DNA methylation in a manner related to the extent of DNA hypomethylation. Production of intracellular methylated metabolites and epigenetic changes of DNA methylation during As2O3 metabolism may contribute to the therapeutic effect of As2O3 in APL. PMID:24819152

  6. Laboratory evaluation of high-temperature sulfur removal sorbents for direct coal-fired turbines: Final report

    SciTech Connect

    Newby, R.A.; DeZubay, E.A.; Chamberlin, R.M.

    1987-06-01

    Direct coal-fired turbine concepts currently being developed require substantial levels of sulfur removal from high-temperature gas streams. Calcium-based sorbents, limestones, dolomites, limes and lime hydrates, are capable of sulfur removal in direct coal-fired turbine combustor environments at temperature up to 1200/degree/C. Two types of desulfurizer processes are considered in this report using calcium- based sorbents: fluidized bed desulfurizer using coarse sorbent particles (300-1000 ..mu..m), and entrained desulfurizer using fine sorbent particles (1-40 ..mu..m). Small-scale laboratory tests were performed on a variety of calcium-based sorbents to determine the kinetics of sulfation and sulfidation over ranges of conditions applicable to both types of desulfurizer processes. Correlations are developed in the report for the effect of pressure; temperature, and particle size. Engineering models are also developed for both desulfurizer types that incorporate the laboratory reaction kinetics and predict potential commercial performance and performance trends. It is concluded that both desulfurizer concepts can be effective in direct coal-fired turbines, with calcium-to-sulfur molar feed ratios ranging from 1.5 to 3.0, if the correct calcium-based sorbent is selected, and if applicable design and operating conditions are identified. Both desulfurizer concepts have limitations and key development requirements, and site and fuel specific engineering assessment is required to select the best concept for a given combustor system. The influence of the desulfurizer concepts on turbine protection, through their influence on particle loading and alkali release must also be assessed. 51 refs., 73 figs., 9 tabs.

  7. A simple synthesis method of sulfur-free Fe-N-C catalyst witih high ORR activity

    SciTech Connect

    Ding, Zhongfen; Johnston, Christina M; Zelenay, Piotr

    2010-01-01

    To try to deconvolute which factors affect the activity and durability of metal-nitrogen-carbon (M-N-C) type non-precious catalysts for oxygen reduction reaction (ORR), M-N-C catalysts based on ion chloride, polyaniline (PANI) and Ketjen Black carbon support were synthesized using different synthetic conditions. The catalysts were characterized electrochemically and tested as cathodes for Hydrogen fuel cells. PANI is usually chemically oxidative polymerized using ammonium persulfate (APS) as oxidant. To eliminate sulfur in the synthesized catalysts, a simple synthesis method using ion chloride as oxidant for aniline polymerization was developed. Two different aniline polymerization conditions led to very different product morphologies. Synthesized at low initial proton concentration, the final product was composed of dense micrometer sized particles. A decomposable salt was found to be able to prohibit PANI cross linking during the drying and annealing process and thus led to porous product. The porous catalyst has much higher ORR activity than the dense product due to more accessible active sites. Synthesized at high proton concentration, the catalyst appeared to be porous. The decomposable salt treatment did not make too much improvement in the porous structure and electrochemical activity. However, fuel cell testing using air as cathode feeder indicates that the salt treatment improves mass transfer in the cathode layer. Catalyst synthesized using this simple method has performance comparable to our state-of-the art catalyst synthesized in a much more complicated procedure. The factor that sulfur sources are completely eliminated in the synthesis suggests that sulfur is not necessary for the ORR catalysis activity.

  8. Flexible carbon nanofiber/polyvinylidene fluoride composite membranes as interlayers in high-performance Lithiumsbnd Sulfur batteries

    NASA Astrophysics Data System (ADS)

    Wang, Zhenhua; Zhang, Jing; Yang, Yuxiang; Yue, Xinyang; Hao, Xiaoming; Sun, Wang; Rooney, David; Sun, Kening

    2016-10-01

    Traditionally polyvinylidene fluoride membranes have been used in applications such as membrane distillation, wastewater treatment, desalination and separator fabrication. Within this work we demonstrate that a novel carbon nanofiber/polyvinylidene fluoride (CNF/PVDF) composite membrane can be used as an interlayer for Lithiumsbnd Sulfur (Lisbnd S) batteries yielding both high capacity and long cycling life. This PVDF membrane is shown to effectively separate dissolved lithium polysulfide with the high electronic conductivity CNF not only reducing the internal resistance in the sulfur cathode but also helping immobilize the polysulfide through its abundant nanospaces. The resulting Lisbnd S battery assembled with the CNF/PVDF composite membrane effectively solves the polysulfide permeation problem and exhibits excellent electrochemical performance. It is further shown that the CNF/PVDF electrode has an excellent cycling stability and retains a capacity of 768.6 mAh g-1 with a coulombic efficiency above 99% over 200 cycles at 0.5C, which is more than twice that of a cell without CNF/PVDF (374 mAh g-1). In addition, the low-cost raw materials and the simple preparation process of CNF/PVDF composite membrane is also amenable for industrial production.

  9. [Transformation characteristics of carbon, nitrogen, phosphorus and sulfur during thermal hydrolysis pretreatment of sludge with high solid content].

    PubMed

    Zhuo, Yang; Han, Yun; Cheng, Yao; Peng, Dang-Cong; Li, Yu-You

    2015-03-01

    The transformation characteristics of carbon, nitrogen, phosphorus and sulfur in dewatering sludge from municipal wastewater treatment plant (WWTP) were investigated after thermal hydrolysis pretreatment at 165 degress C for 50 min. The results showed that the hydrolysis efficiency of VSS could reach as high as 43.35%, 54.36% of protein and 65.12% of carbohydrate were transferred to dissolved organics, respectively, and the main component of dissolved organic matter in hydrolysate was dissolved protein (52.18% ), 54.23% of insoluble organic nitrogen was turned into dissolved nitrogen and 22.13% of dissolved nitrogen in hydrolysate was converted to ammonia. The transformation rate of insoluble phosphorus was 30.52%. Dissolved phosphorus was mostly transformed to phosphate (79.84%) as phosphorus-accumulating bacteria cells were crushed. 50.03% of insoluble organic sulfur was hydrolyzed, and little change was detected in sulfide (0.50%). The analysis results of the organic compounds transformation are valuable for treatment of the thermal hydrolysis pretreated sludge with high solid content.

  10. High Permeability Ternary Palladium Alloy Membranes with Improved Sulfur and Halide Tolerances

    SciTech Connect

    K. Coulter

    2010-12-31

    The project team consisting of Southwest Research Institute{reg_sign} (SwRI{reg_sign}), Georgia Institute of Technology (GT), the Colorado School of Mines (CSM), TDA Research, and IdaTech LLC was focused on developing a robust, poison-tolerant, hydrogen selective free standing membrane to produce clean hydrogen. The project completed on schedule and on budget with SwRI, GT, CSM, TDA and IdaTech all operating independently and concurrently. GT has developed a robust platform for performing extensive DFT calculations for H in bulk palladium (Pd), binary alloys, and ternary alloys of Pd. Binary alloys investigated included Pd96M4 where M = Li, Na, Mg, Al, Si, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Y, Zr, Nb, Mo, Tc, Ru, Rh, Ag, Cd, In, Sn, Sb, Te, Hf, Ta, W, Re, Os, Ir, Pt, Au, Tl, Pb, Bi, Ce, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu. They have also performed a series of calculations on Pd{sub 70}Cu{sub 26}Ag{sub 4}, Pd{sub 70}Cu{sub 26}Au{sub 4}, Pd{sub 70}Cu{sub 26}Ni{sub 4}, Pd{sub 70}Cu{sub 26}Pt{sub 4}, and Pd{sub 70}Cu{sub 26}Y{sub 4}. SwRI deposited and released over 160 foils of binary and ternary Pd alloys. There was considerable work on characterizing and improving the durability of the deposited foils using new alloy compositions, post annealing and ion bombardment. The 10 and 25 {micro}m thick films were sent to CSM, TDA and IdaTech for characterization and permeation testing. CSM conducted over 60 pure gas permeation tests with SwRI binary and ternary alloy membranes. To date the PdAu and PdAuPt membranes have exhibited the best performance at temperatures in the range of 423-773 C and their performance correlates well with the predictions from GT. TDA completed testing under the Department of Energy (DOE) WGS conditions on over 16 membranes. Of particular interest are the PdAuPt alloys that exhibited only a 20% drop in flux when sulfur was added to the gas mixture and the flux was completely recovered when the sulfur flow was stopped. IdaTech tested binary

  11. Thermodynamic modeling of REE behavior in oxidized hydrothermal fluids of high sulfate sulfur concentrations

    NASA Astrophysics Data System (ADS)

    Shironosova, G. P.; Kolonin, G. R.; Borovikov, A. A.; Borisenko, A. S.

    2016-08-01

    Thermodynamic calculations using the HCh software were made for mineral equilibriums including REEs in the fluoride-sulfide-chloride-carbonate-sulfate-system in the presence of Na, Ca, and P with fluids of various acidities-alkalinities [11]. The obtained thermodynamic characteristics of thenardite allowed us to carry out the calculations for this phase under complicated hydrothermal conditions simulating the presence of oxidized fluids at 500-100°C and 2000-125 bar. Among other solid phases, REEs-fluorite, monazite, and REE-F-apatite were formed as CaF2-(Ln,Y)F3, LnPO4, and Ca5(PO4)3F-(Ln,Y)3(PO4)3 ideal solid solutions, respectively, where Ln is La, Ce, Pr, Nd, Sm, Eu, and Gd. Xenotime, anhydrite, elemental sulfur, and calcite were found as well.

  12. Functionalized graphene-based cathode for highly reversible lithium-sulfur batteries.

    PubMed

    Kim, Jin Won; Ocon, Joey D; Park, Dong-Won; Lee, Jaeyoung

    2014-05-01

    In this article, we highlight the salient issues in the development of lithium-sulfur battery (LSB) cathodes, present different points of view in solving them, and argue, why in the future, functionalized graphene or graphene oxide might be the ultimate solution towards LSB commercialization. As shown by previous studies and also in our recent work, functionalized graphene and graphene oxide enhance the reversibility of the charge-discharge process by trapping polysulfides in the oxygen functional groups on the graphene surface, thus minimizing polysulfide dissolution. This will be helpful for the rational design of new cathode structures based on graphene for LSBs with minimal capacity fading, low extra cost, and without the unnecessary weight increase caused by metal/metal oxide additives. PMID:24464910

  13. Functionalized graphene-based cathode for highly reversible lithium-sulfur batteries.

    PubMed

    Kim, Jin Won; Ocon, Joey D; Park, Dong-Won; Lee, Jaeyoung

    2014-05-01

    In this article, we highlight the salient issues in the development of lithium-sulfur battery (LSB) cathodes, present different points of view in solving them, and argue, why in the future, functionalized graphene or graphene oxide might be the ultimate solution towards LSB commercialization. As shown by previous studies and also in our recent work, functionalized graphene and graphene oxide enhance the reversibility of the charge-discharge process by trapping polysulfides in the oxygen functional groups on the graphene surface, thus minimizing polysulfide dissolution. This will be helpful for the rational design of new cathode structures based on graphene for LSBs with minimal capacity fading, low extra cost, and without the unnecessary weight increase caused by metal/metal oxide additives.

  14. Short-Term Fates of High Sulfur Inputs in Northern California Vineyard Soils

    SciTech Connect

    E Hinckley; S Fendorf; P Matson

    2011-12-31

    The widespread application of elemental sulfur (S{sup 0}) to vineyards may have ecosystem effects at multiple scales. We evaluated the short-term fates of applied S{sup 0} in a Napa Valley vineyard; we determined changes in soil sulfur (S) speciation (measured by X-ray absorption near-edge structure (XANES) spectroscopy), soil pH, extractable sulfate (SO{sub 4}{sup 2-}), and total S to evaluate changes in acidity and soil S within the vineyard over time. Surface soil samples were collected immediately prior to and following two applications of S{sup 0} (6.7 kg S{sup 0} ha{sup -1}), with weekly collections in the 2 weeks between applications and following the last application. XANES spectra indicated that the majority of soil S persists in the +6 oxidation state and that S{sup 0} oxidizes within 7 days following application. Soil pH and extractable SO{sub 4}{sup 2-} measurements taken at 30 min after S{sup 0} application revealed generation of acidity and an increase in extractable SO{sub 4}{sup 2-}, but by 12 days after application, soil pH increased to approximately pre-application levels. These data suggest that the major consequence of reactive S applications in vineyards may be the accumulation of soil SO{sub 4}{sup 2-} and organic S during the growing season, which can be mobilized during storm events during the dormant (wet) season. In spatially-extensive winegrowing regions where these applications are made by hundreds of individual farmers each year, it will be important to understand the long-term implications of this perturbation to the regional S cycle.

  15. Transformations, transport, and potential unintended consequences of high sulfur inputs to Napa Valley vineyards.

    PubMed

    Hinckley, Eve-Lyn S; Matson, Pamela A

    2011-08-23

    Unintended anthropogenic deposition of sulfur (S) to forest ecosystems has a range of negative consequences, identified through decades of research. There has been far less study of purposeful S use in agricultural systems around the world, including the application of elemental sulfur (S(0)) as a quick-reacting fungicide to prevent damage to crops. Here we report results from a three-year study of the transformations and flows of applied S(0) in soils, vegetation, and hydrologic export pathways of Napa Valley, CA vineyards, documenting that all applied S is lost from the vineyard ecosystem on an annual basis. We found that S(0) oxidizes rapidly to sulfate ( ) on the soil surface where it then accumulates over the course of the growing season. Leaf and grape tissues accounted for only 7-13% of applied S whereas dormant season cover crops accounted for 4-10% of applications. Soil S inventories were largely and ester-bonded sulfates; they decreased from 1,623 ± 354 kg ha(-1) during the dry growing season to 981 ± 526 kg ha(-1) (0-0.5 m) during the dormant wet season. Nearly all S applied to the vineyard soils is transported offsite in dissolved oxidized forms during dormant season rainstorms. Thus, the residence time of reactive S is brief in these systems, and largely driven by hydrology. Our results provide new insight into how S use in vineyards constitutes a substantial perturbation of the S cycle in Northern California winegrowing regions and points to the unintended consequences that agricultural S use may have at larger scales.

  16. Demonstration of SCR technology for the control of NOx emissions from high-sulfur coal-fired utility boilers

    SciTech Connect

    Hinton, W.S.; Maxwell, J.D.; Healy, E.C.; Hardman, R.R.; Baldwin, A.L.

    1997-12-31

    This paper describes the completed Innovative Clean Coal Technology project which demonstrated SCR technology for reduction of flue gas NO{sub x} emissions from a utility boiler burning US high-sulfur coal. The project was sponsored by the US Department of Energy, managed and co-funded by Southern Company Services, Inc. on behalf of the Southern Company, and also co-funded by the Electric Power Research Institute and Ontario Hydro. The project was located at Gulf Power Company`s Plant Crist Unit 5 (a 75 MW tangentially-fired boiler burning US coals that had a sulfur content ranging from 2.5--2.9%), near Pensacola, Florida. The test program was conducted for approximately two years to evaluate catalyst deactivation and other SCR operational effects. The SCR test facility had nine reactors: three 2.5 MW (5,000 scfm), and operated on low-dust flue gas. The reactors operated in parallel with commercially available SCR catalysts obtained from suppliers throughout the world. Long-term performance testing began in July 1993 and was completed in July 1995. A brief test facility description and the results of the project are presented in this paper.

  17. Ultrafine TiO2 Decorated Carbon Nanofibers as Multifunctional Interlayer for High-Performance Lithium-Sulfur Battery.

    PubMed

    Liang, Gemeng; Wu, Junxiong; Qin, Xianying; Liu, Ming; Li, Qing; He, Yan-Bing; Kim, Jang-Kyo; Li, Baohua; Kang, Feiyu

    2016-09-01

    Although lithium-sulfur (Li-S) batteries deliver high specific energy densities, lots of intrinsic and fatal obstacles still restrict their practical application. Electrospun carbon nanofibers (CNFs) decorated with ultrafine TiO2 nanoparticles (CNF-T) were prepared and used as a multifunctional interlayer to suppress the volume expansion and shuttle effect of Li-S battery. With this strategy, the CNF network with abundant space and superior conductivity can accommodate and recycle the dissolved polysulfides for the bare sulfur cathode. Meanwhile, the ultrafine TiO2 nanoparticles on CNFs work as anchoring points to capture the polysulfides with the strong interaction, making the battery perform with remarkable and stable electrochemical properties. As a result, the Li-S battery with the CNF-T interlayer delivers an initial reversible capacity of 935 mA h g(-1) at 1 C with a capacity retention of 74.2% after 500 cycles. It is believed that this simple, low-cost and scalable method will definitely bring a novel perspective on the practical utilization of Li-S batteries. PMID:27508357

  18. High-Resolution Infrared Spectroscopy of Carbon-Sulfur Chains: II. C_5S and SC_5S

    NASA Astrophysics Data System (ADS)

    Thorwirth, Sven; Salomon, Thomas; Dudek, John B.

    2016-06-01

    Unbiased high-resolution infrared survey scans of the ablation products from carbon-sulfur targets in the 2100 to 2150 cm-1 regime reveal two bands previously not observed in the gas phase. On the basis of comparison against laboratory matrix-isolation work and new high-level quantum-chemical calculations these bands are attributed to the linear C_5S and SC_5S clusters. While polar C_5S was studied earlier using Fourier-transform microwave techniques, the present work marks the first gas-phase spectroscopic detection of SC_5S. H. Wang, J. Szczepanski, P. Brucat, and M. Vala 2005, Int. J. Quant. Chem. 102, 795 Y. Kasai, K. Obi, Y. Ohshima, Y. Hirahara, Y. Endo, K. Kawaguchi, and A. Murakami 1993, ApJ 410, L45 V. D. Gordon, M. C. McCarthy, A. J. Apponi, and P. Thaddeus 2001, ApJS 134, 311

  19. Factors Determining Sensitivity and Resistance of Tumor Cells to Arsenic Trioxide

    PubMed Central

    Sertel, Serkan; Tome, Margaret; Briehl, Margaret M.; Bauer, Judith; Hock, Kai; Plinkert, Peter K.; Efferth, Thomas

    2012-01-01

    Previously, arsenic trioxide showed impressive regression rates of acute promyelocytic leukemia. Here, we investigated molecular determinants of sensitivity and resistance of cell lines of different tumor types towards arsenic trioxide. Arsenic trioxide was the most cytotoxic compound among 8 arsenicals investigated in the NCI cell line panel. We correlated transcriptome-wide microarray-based mRNA expression to the IC50 values for arsenic trioxide by bioinformatic approaches (COMPARE and hierarchical cluster analyses, Ingenuity signaling pathway analysis). Among the identified pathways were signaling routes for p53, integrin-linked kinase, and actin cytoskeleton. Genes from these pathways significantly predicted cellular response to arsenic trioxide. Then, we analyzed whether classical drug resistance factors may also play a role for arsenic trioxide. Cell lines transfected with cDNAs for catalase, thioredoxin, or the anti-apoptotic bcl-2 gene were more resistant to arsenic trioxide than mock vector transfected cells. Multidrug-resistant cells overexpressing the MDR1, MRP1 or BCRP genes were not cross-resistant to arsenic trioxide. Our approach revealed that response of tumor cells towards arsenic trioxide is multi-factorial. PMID:22590507

  20. In situ sulfur isotopes (δ(34)S and δ(33)S) analyses in sulfides and elemental sulfur using high sensitivity cones combined with the addition of nitrogen by laser ablation MC-ICP-MS.

    PubMed

    Fu, Jiali; Hu, Zhaochu; Zhang, Wen; Yang, Lu; Liu, Yongsheng; Li, Ming; Zong, Keqing; Gao, Shan; Hu, Shenghong

    2016-03-10

    The sulfur isotope is an important geochemical tracer in diverse fields of geosciences. In this study, the effects of three different cone combinations with the addition of N2 on the performance of in situ S isotope analyses were investigated in detail. The signal intensities of S isotopes were improved by a factor of 2.3 and 3.6 using the X skimmer cone combined with the standard sample cone or the Jet sample cone, respectively, compared with the standard arrangement (H skimmer cone combined with the standard sample cone). This signal enhancement is important for the improvement of the precision and accuracy of in situ S isotope analysis at high spatial resolution. Different cone combinations have a significant effect on the mass bias and mass bias stability for S isotopes. Poor precisions of S isotope ratios were obtained using the Jet and X cones combination at their corresponding optimum makeup gas flow when using Ar plasma only. The addition of 4-8 ml min(-1) nitrogen to the central gas flow in laser ablation MC-ICP-MS was found to significantly enlarge the mass bias stability zone at their corresponding optimum makeup gas flow in these three different cone combinations. The polyatomic interferences of OO, SH, OOH were also significantly reduced, and the interference free plateaus of sulfur isotopes became broader and flatter in the nitrogen mode (N2 = 4 ml min(-1)). However, the signal intensity of S was not increased by the addition of nitrogen in this study. The laser fluence and ablation mode had significant effects on sulfur isotope fractionation during the analysis of sulfides and elemental sulfur by laser ablation MC-ICP-MS. The matrix effect among different sulfides and elemental sulfur was observed, but could be significantly reduced by line scan ablation in preference to single spot ablation under the optimized fluence. It is recommended that the d90 values of the particles in pressed powder pellets for accurate and precise S isotope analysis

  1. In situ sulfur isotopes (δ(34)S and δ(33)S) analyses in sulfides and elemental sulfur using high sensitivity cones combined with the addition of nitrogen by laser ablation MC-ICP-MS.

    PubMed

    Fu, Jiali; Hu, Zhaochu; Zhang, Wen; Yang, Lu; Liu, Yongsheng; Li, Ming; Zong, Keqing; Gao, Shan; Hu, Shenghong

    2016-03-10

    The sulfur isotope is an important geochemical tracer in diverse fields of geosciences. In this study, the effects of three different cone combinations with the addition of N2 on the performance of in situ S isotope analyses were investigated in detail. The signal intensities of S isotopes were improved by a factor of 2.3 and 3.6 using the X skimmer cone combined with the standard sample cone or the Jet sample cone, respectively, compared with the standard arrangement (H skimmer cone combined with the standard sample cone). This signal enhancement is important for the improvement of the precision and accuracy of in situ S isotope analysis at high spatial resolution. Different cone combinations have a significant effect on the mass bias and mass bias stability for S isotopes. Poor precisions of S isotope ratios were obtained using the Jet and X cones combination at their corresponding optimum makeup gas flow when using Ar plasma only. The addition of 4-8 ml min(-1) nitrogen to the central gas flow in laser ablation MC-ICP-MS was found to significantly enlarge the mass bias stability zone at their corresponding optimum makeup gas flow in these three different cone combinations. The polyatomic interferences of OO, SH, OOH were also significantly reduced, and the interference free plateaus of sulfur isotopes became broader and flatter in the nitrogen mode (N2 = 4 ml min(-1)). However, the signal intensity of S was not increased by the addition of nitrogen in this study. The laser fluence and ablation mode had significant effects on sulfur isotope fractionation during the analysis of sulfides and elemental sulfur by laser ablation MC-ICP-MS. The matrix effect among different sulfides and elemental sulfur was observed, but could be significantly reduced by line scan ablation in preference to single spot ablation under the optimized fluence. It is recommended that the d90 values of the particles in pressed powder pellets for accurate and precise S isotope analysis

  2. Conductive Carbon Network inside a Sulfur-Impregnated Carbon Sponge: A Bioinspired High-Performance Cathode for Li-S Battery.

    PubMed

    Du, Xue-Li; You, Ya; Yan, Yang; Zhang, Dawei; Cong, Huai-Ping; Qin, Haili; Zhang, Chaofeng; Cao, Fei-Fei; Jiang, Ke-Cheng; Wang, Yan; Xin, Sen; He, Jian-Bo

    2016-08-31

    A highly conductive sulfur cathode is crucial for improving the kinetic performance of a Li-S battery. The encapsulation of sulfur in porous nanocarbons is expected to benefit the Li(+) migration, yet the e(-) conduction is still to be improved due to a low graphitization degree of a conventional carbon substrate, especially that pyrolyzed from carbohydrates or polymers. Aiming at facilitating the e(-) conduction in the cathode, here we propose to use ketjen black, a highly graphitized nanocarbon building block to form a conductive network for electrons in a biomass-derived, hierarchically porous carbon sponge by a easily scaled-up approach at a low cost. The specifically designed carbon host ensures a high loading and good retention of active sulfur, while also provides a faster electron transmission to benefit the lithiation/delithiation kinetics of sulfur. The sulfur cathode prepared from the carbon network shows excellent cycling and rate performance in a Li-S battery, rendering its practicality for emerging energy storage opportunities such as grids or automobiles. PMID:27502841

  3. Development of advanced, dry, SO{sub x}/NO{sub x} emission control technologies for high-sulfur coal. Final report, April 1, 1993--December 31, 1994

    SciTech Connect

    Amrhein, G.T.

    1994-12-23

    Dry Scrubbing is a common commercial process that has been limited to low- and medium-sulfur coal applications because high-sulfur coal requires more reagent than can be efficiently injected into the process. Babcock & Wilcox has made several advances that extend dry scrubbing technologies to higher sulfur coals by allowing deposit-free operation at low scrubber exit temperatures. This not only increases the amount of reagent that can be injected into the scrubber, but also increases SO{sub 2} removal efficiency and sorbent utilization. The objectives of this project were to demonstrate, at pilot scale, that advanced, dry-scrubbing-based technologies can attain the performance levels specified by the 1990 Clean Air Act Amendments for SO{sub 2} and NO{sub x} emissions while burning high-sulfur coal, and that these technologies are economically competitive with wet scrubber systems. The use of these technologies by utilities in and around Ohio, on new or retrofit applications, will ensure the future of markets for high-sulfur coal by creating cost effective options to coal switching.

  4. Conductive Carbon Network inside a Sulfur-Impregnated Carbon Sponge: A Bioinspired High-Performance Cathode for Li-S Battery.

    PubMed

    Du, Xue-Li; You, Ya; Yan, Yang; Zhang, Dawei; Cong, Huai-Ping; Qin, Haili; Zhang, Chaofeng; Cao, Fei-Fei; Jiang, Ke-Cheng; Wang, Yan; Xin, Sen; He, Jian-Bo

    2016-08-31

    A highly conductive sulfur cathode is crucial for improving the kinetic performance of a Li-S battery. The encapsulation of sulfur in porous nanocarbons is expected to benefit the Li(+) migration, yet the e(-) conduction is still to be improved due to a low graphitization degree of a conventional carbon substrate, especially that pyrolyzed from carbohydrates or polymers. Aiming at facilitating the e(-) conduction in the cathode, here we propose to use ketjen black, a highly graphitized nanocarbon building block to form a conductive network for electrons in a biomass-derived, hierarchically porous carbon sponge by a easily scaled-up approach at a low cost. The specifically designed carbon host ensures a high loading and good retention of active sulfur, while also provides a faster electron transmission to benefit the lithiation/delithiation kinetics of sulfur. The sulfur cathode prepared from the carbon network shows excellent cycling and rate performance in a Li-S battery, rendering its practicality for emerging energy storage opportunities such as grids or automobiles.

  5. Sulfur poisoning of CeO[subscript 2]-Al[subscript 2]O[subscript 3]-supported mono- and bi-metallic Ni and Rh catalysts in steam reforming of liquid hydrocarbons at low and high temperatures

    SciTech Connect

    Xie, Chao; Chen, Yongsheng; Li, Yan; Wang, Xiaoxing; Song, Chunshan

    2010-12-01

    In order to develop a better understanding on sulfur poisoning of reforming catalysts in fuel processing for hydrogen production, steam reforming of liquid hydrocarbons was performed over CeO{sub 2}-Al{sub 2}O{sub 3} supported monometallic Ni and Rh and bimetallic Rh-Ni catalysts at 550 and 800 C. XANES was used to identify the sulfur species in the used catalysts and to study their impacts on the metal surface properties probed by XPS. It was found that both monometallic catalysts rapidly deactivated at 550 C, and showed poor sulfur tolerance. Although ineffective for the Ni catalyst, increasing the temperature to 800 C dramatically improved the sulfur tolerance of the Rh catalyst. XANES revealed that metal sulfide and organic sulfide are the dominant sulfur species on the used Ni catalyst, while sulfonate and sulfate predominate on the used Rh catalyst. The presence of sulfur induced severe carbon deposition on the Ni catalyst at 800 C. The superior sulfur tolerance of the Rh catalyst at 800 C may be associated with its capability in sulfur oxidation. It is likely that the formation of the oxygen-shielded sulfur structure of sulfonate and sulfate can suppress the poisoning impact of sulfur on Rh by inhibiting direct rhodium-sulfur interaction. Moreover, XPS indicated that the metal surface properties of the Rh catalysts after the reaction without and with sulfur at 800 C are similar, suggesting that sulfur poisoning on Rh was mitigated under the high-temperature condition. Although the Rh-Ni catalyst exhibited better sulfur tolerance than the monometallic catalysts at 550 C, its catalytic performance was inferior compared with the Rh catalyst in the sulfur-containing reaction at 800 C probably due to the severe carbon deposition on the bimetallic catalyst.

  6. COMBINED RETENTION OF MOLYBDENUM AND SULFUR IN SIMULATED HIGH LEVEL WASTE GLASS

    SciTech Connect

    Fox, K.

    2009-10-16

    This study was undertaken to investigate the effect of elevated sulfate and molybdenum concentrations in nuclear waste glasses. A matrix of 24 glasses was developed and the glasses were tested for acceptability based on visual observations, canister centerline-cooled heat treatments, and chemical composition analysis. Results from the chemical analysis of the rinse water from each sample were used to confirm the presence of SO{sup 2-}{sub 4} and MoO{sub 3} on the surface of glasses as well as other components which might form water soluble compounds with the excess sulfur and molybdenum. A simple, linear model was developed to show acceptable concentrations of SO{sub 4}{sup 2-} and MoO{sub 3} in an example waste glass composition. This model was constructed for scoping studies only and is not ready for implementation in support of actual waste vitrification. Several other factors must be considered in determining the limits of sulfate and molybdenum concentrations in the waste vitrification process, including but not limited to, impacts on refractory and melter component corrosion, effects on the melter off-gas system, and impacts on the chemical durability and crystallization of the glass product.

  7. Controlled Growth of Platinum Nanowire Arrays on Sulfur Doped Graphene as High Performance Electrocatalyst

    PubMed Central

    Wang, Rongyue; Higgins, Drew C.; Hoque, Md Ariful; Lee, DongUn; Hassan, Fathy; Chen, Zhongwei

    2013-01-01

    Graphene supported Pt nanostructures have great potential to be used as catalysts in electrochemical energy conversion and storage technologies; however the simultaneous control of Pt morphology and dispersion, along with ideally tailoring the physical properties of the catalyst support properties has proven very challenging. Using sulfur doped graphene (SG) as a support material, the heterogeneous dopant atoms could serve as nucleation sites allowing for the preparation of SG supported Pt nanowire arrays with ultra-thin diameters (2–5 nm) and dense surface coverage. Detailed investigation of the preparation technique reveals that the structure of the resulting composite could be readily controlled by fine tuning the Pt nanowire nucleation and growth reaction kinetics and the Pt-support interactions, whereby a mechanistic platinum nanowire array growth model is proposed. Electrochemical characterization demonstrates that the composite materials have 2–3 times higher catalytic activities toward the oxygen reduction and methanol oxidation reaction compared with commercial Pt/C catalyst. PMID:23942256

  8. Determination of total sulfur in fertilizers by high temperature combustion: single-laboratory validation.

    PubMed

    Bernius, Jean; Kraus, Sabine; Hughes, Sandra; Margraf, Dominik; Bartos, James; Newlon, Natalie; Sieper, Hans-Peter

    2014-01-01

    Asingle-laboratory validation study was conducted for the determination of total sulfur (S) in a variety of common, inorganic fertilizers by combustion. The procedure involves conversion of S species into SO2 through combustion at 1150 degrees C, absorption then desorption from a purge and trap column, followed by measurement by a thermal conductivity detector. Eleven different validation materials were selected for study, which included four commercial fertilizer products, five fertilizers from the Magruder Check Sample Program, one reagent grade product, and one certified organic reference material. S content ranged between 1.47 and 91% as sulfate, thiosulfate, and elemental and organically bound S. Determinations of check samples were performed on 3 different days with four replicates/day. Determinations for non-Magruder samples were performed on 2 different days. Recoveries ranged from 94.3 to 125.9%. ABS SL absolute SD among runs ranged from 0.038 to 0.487%. Based on the accuracy and precision demonstrated here, it is recommended that this method be collaboratively studied for the determination of total S in fertilizers.

  9. High sulfur isotope fractionation associated with anaerobic oxidation of methane in a low sulfate, iron rich environment

    NASA Astrophysics Data System (ADS)

    Weber, Hannah; Thamdrup, Bo; Habicht, Kirsten

    2016-06-01

    Sulfur isotope signatures provide key information for the study of microbial activity in modern systems and the evolution of the Earth surface redox system. Microbial sulfate reducers shift sulfur isotope distributions by discriminating against heavier isotopes. This discrimination is strain-specific and often suppressed at sulfate concentrations in the lower micromolar range that are typical to freshwater systems and inferred for ancient oceans. Anaerobic oxidation of methane (AOM) is a sulfate-reducing microbial process with a strong impact on global sulfur cycling in modern habitats and potentially in the geological past, but its impact on sulfur isotope signatures is poorly understood, especially in low sulfate environments. We investigated sulfur cycling and 34S fractionation in a low-sulfate freshwater sediment with biogeochemical conditions analogous to Early Earth environments. The zone of highest AOM activity was associated in situ with a zone of strong 34S depletions in the pool of reduced sulfur species, indicating a coupling of sulfate reduction and AOM at sulfate concentrations < 50 µmol L-1. In slurry incubations of AOM-active sediment, the addition of methane stimulated sulfate reduction and induced a bulk sulfur isotope effect of ~29 ‰. Our results imply that sulfur isotope signatures may be strongly impacted by AOM even at sulfate concentrations two orders of magnitude lower than at present oceanic levels. Therefore, we suggest that sulfur isotope fractionation during AOM must be considered when interpreting 34S signatures in modern and ancient environment.

  10. Have all-trans retinoic acid and arsenic trioxide replaced all-trans retinoic acid and anthracyclines in APL as standard of care.

    PubMed

    Iland, Harry J; Wei, Andrew; Seymour, John F

    2014-03-01

    Until recently, the standard of care in the treatment of APL has involved the combination of all-trans retinoic acid with anthracycline-based chemotherapy during both induction and consolidation. Additionally, the intensity of consolidation chemotherapy has evolved according to a universally accepted relapse-risk stratification algorithm based on the white cell and platelet counts at presentation. That standard of care is being challenged by the increasing incorporation of arsenic trioxide into front-line treatment protocols, based on two complementary observations. The first is the undoubted anti-leukaemic activity of arsenic trioxide as shown in the relapsed and refractory setting, and in the initial management of low- and intermediate-risk patients. The second is an improved understanding of the action of both all-trans retinoic acid and arsenic trioxide in mediating APL cell eradication, with increasing recognition that PML-RARA fusion protein degradation rather than direct induction of terminal differentiation is the primary mechanism for their ability to eliminate leukaemia initiating cells. As a result, we believe the standard of care for initial therapy in APL is shifting towards an all-trans retinoic acid plus arsenic trioxide-based approach, with additional chemotherapy reserved for patients with high-risk disease. PMID:24907016

  11. Degradation of self-compacting concrete (SCC) due to sulfuric acid attack: Experiment investigation on the effect of high volume fly ash content

    NASA Astrophysics Data System (ADS)

    Kristiawan, S. A.; Sunarmasto; Tyas, G. P.

    2016-02-01

    Concrete is susceptible to a variety of chemical attacks. In the sulfuric acid environment, concrete is subjected to a combination of sulfuric and acid attack. This research is aimed to investigate the degradation of self-compacting concrete (SCC) due to sulfuric acid attack based on measurement of compressive strength loss and diameter change. Since the proportion of SCC contains higher cement than that of normal concrete, the vulnerability of this concrete to sulfuric acid attack could be reduced by partial replacement of cement with fly ash at high volume level. The effect of high volume fly ash at 50-70% cement replacement levels on the extent of degradation owing to sulfuric acid will be assessed in this study. It can be shown that an increase in the utilization of fly ash to partially replace cement tends to reduce the degradation as confirmed by less compressive strength loss and diameter change. The effect of fly ash to reduce the degradation of SCC is more pronounced at a later age.

  12. A Simplified Method for Quantifying Sulfur Mustard Adducts to Blood Proteins by Ultra-High Pressure Liquid Chromatography-Isotope Dilution Tandem Mass Spectrometry

    PubMed Central

    Pantazides, Brooke G.; Crow, Brian S.; Garton, Joshua W.; Quiñones-González, Jennifer A.; Blake, Thomas A.; Thomas, Jerry D.; Johnson, Rudolph C.

    2016-01-01

    Sulfur mustard binds to reactive cysteine residues, forming a stable sulfur-hydroxyethylthioethyl [S-HETE] adduct that can be used as a long-term biomarker of sulfur mustard exposure in humans. The digestion of sulfur mustard-exposed blood samples with proteinase K following total protein precipitation with acetone produces the tripeptide biomarker [S-HETE]-Cys-Pro-Phe. The adducted tripeptide is purified by solid phase extraction, separated by ultra-high pressure liquid chromatography, and detected by isotope dilution tandem mass spectrometry. This approach was thoroughly validated and characterized in our laboratory. The average interday relative standard deviation was ≤ 9.49%, and the range of accuracy was between 96.1-109% over a concentration range of 3.00 to 250. ng/mL with a calculated limit of detection of 1.74 ng/mL. A full 96-well plate can be processed and analyzed in 8 h which is five times faster than our previous 96-well plate method and only requires 50 µL of serum, plasma, or whole blood. Extensive ruggedness and stability studies and matrix comparisons were conducted to create a robust, easily transferrable method. As a result, a simple and high-throughput method has been developed and validated for the quantitation of sulfur mustard blood protein adducts in low volume blood specimens which should be readily adaptable for quantifying human exposures to other alkylating agents. PMID:25622494

  13. A maize gene encoding an NADPH binding enzyme highly homologous to isoflavone reductases is activated in response to sulfur starvation.

    PubMed

    Petrucco, S; Bolchi, A; Foroni, C; Percudani, R; Rossi, G L; Ottonello, S

    1996-01-01

    we isolated a novel gene that is selectively induced both in roots and shoots in response to sulfur starvation. This gene encodes a cytosolic, monomeric protein of 33 kD that selectively binds NADPH. The predicted polypeptide is highly homologous ( > 70%) to leguminous isoflavone reductases (IFRs), but the maize protein (IRL for isoflavone reductase-like) belongs to a novel family of proteins present in a variety of plants. Anti-IRL antibodies specifically recognize IFR polypeptides, yet the maize protein is unable to use various isoflavonoids as substrates. IRL expression is correlated closely to glutathione availability: it is persistently induced in seedlings whose glutathione content is about fourfold lower than controls, and it is down-regulated rapidly when control levels of glutathione are restored. This glutathione-dependent regulation indicates that maize IRL may play a crucial role in the establishment of a thiol-independent response to oxidative stress under glutathione shortage conditions.

  14. A maize gene encoding an NADPH binding enzyme highly homologous to isoflavone reductases is activated in response to sulfur starvation.

    PubMed Central

    Petrucco, S; Bolchi, A; Foroni, C; Percudani, R; Rossi, G L; Ottonello, S

    1996-01-01

    we isolated a novel gene that is selectively induced both in roots and shoots in response to sulfur starvation. This gene encodes a cytosolic, monomeric protein of 33 kD that selectively binds NADPH. The predicted polypeptide is highly homologous ( > 70%) to leguminous isoflavone reductases (IFRs), but the maize protein (IRL for isoflavone reductase-like) belongs to a novel family of proteins present in a variety of plants. Anti-IRL antibodies specifically recognize IFR polypeptides, yet the maize protein is unable to use various isoflavonoids as substrates. IRL expression is correlated closely to glutathione availability: it is persistently induced in seedlings whose glutathione content is about fourfold lower than controls, and it is down-regulated rapidly when control levels of glutathione are restored. This glutathione-dependent regulation indicates that maize IRL may play a crucial role in the establishment of a thiol-independent response to oxidative stress under glutathione shortage conditions. PMID:8597660

  15. Electronic and ionic co-conductive coating on the separator towards high-performance lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Wang, Qingsong; Wen, Zhaoyin; Yang, Jianhua; Jin, Jun; Huang, Xiao; Wu, Xiangwei; Han, Jinduo

    2016-02-01

    A thin coating layer composed of the mixture of the electronic conductive carbon and lithium ionic conductive inorganic solid electrolyte was introduced on one side of the routine Celgard separator. This functional coated separator is designed to localize the polysulfides on the cathode side and act as an upper current collector for further utilization of sulfur while alleviating the ion conductivity decrease induced by the dissolved polysulfides in the discharge and charge process. Moreover, catalytic conversion of polysulfides by the solid state highly ionic conductor is observed. This brings significant improvement in battery specific capacity and cycling stability, with an initial discharge capacity of 1247 mA h g-1 and a reversible capacity of 830 mA h g-1 after 150 extended cycles at 0.5 C rate. Rest-testing proves a low self-discharge and excellent capacity retention of the modified cells.

  16. Catalyst for the reduction of sulfur dioxide to elemental sulfur

    DOEpatents

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

    1996-02-27

    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.

  17. Potential role of stabilized Criegee radicals in sulfuric acid production in a high biogenic VOC environment.

    PubMed

    Kim, Saewung; Guenther, Alex; Lefer, Barry; Flynn, James; Griffin, Robert; Rutter, Andrew P; Gong, Longwen; Cevik, Basak Karakurt

    2015-03-17

    We present field observations made in June 2011 downwind of Dallas-Fort Worth, TX, and evaluate the role of stabilized Criegee radicals (sCIs) in gaseous sulfuric acid (H2SO4) production. Zero-dimensional model calculations show that sCI from biogenic volatile organic compounds composed the majority of the sCIs. The main uncertainty associated with an evaluation of H2SO4 production from the sCI reaction channel is the lack of experimentally determined reaction rates for sCIs formed from isoprene ozonolysis with SO2 along with systematic discrepancies in experimentally derived reaction rates between other sCIs and SO2 and water vapor. In general, the maximum of H2SO4 production from the sCI channel is found in the late afternoon as ozone increases toward the late afternoon. The sCI channel, however, contributes minor H2SO4 production compared with the conventional OH channel in the mid-day. Finally, the production and the loss rates of H2SO4 are compared. The application of the recommended mass accommodation coefficient causes significant overestimation of H2SO4 loss rates compared with H2SO4 production rates. However, the application of a lower experimental value for the mass accommodation coefficient provides good agreement between the loss and production rates of H2SO4. The results suggest that the recommended coefficient for the H2O surface may not be suitable for this relatively dry environment. PMID:25700170

  18. Designing and Validating Ternary Pd Alloys for Optimum Sulfur/Carbon Resistance in Hydrogen Separation and Carbon Capture Membrane Systems Using High-Throughput Combinatorial Methods

    SciTech Connect

    Lewis, Amanda; Zhao, Hongbin; Hopkins, Scott

    2014-09-30

    This report summarizes the work completed under the U.S. Department of Energy Project Award No.: DE-FE0001181 titled “Designing and Validating Ternary Pd Alloys for Optimum Sulfur/Carbon Resistance in Hydrogen Separation and Carbon Capture Membrane Systems Using High-Throughput Combinatorial Methods.” The project started in October 1, 2009 and was finished September 30, 2014. Pall Corporation worked with Cornell University to sputter and test palladium-based ternary alloys onto silicon wafers to examine many alloys at once. With the specialized equipment at Georgia Institute of Technology that analyzed the wafers for adsorbed carbon and sulfur species six compositions were identified to have resistance to carbon and sulfur species. These compositions were deposited on Pall AccuSep® supports by Colorado School of Mines and then tested in simulated synthetic coal gas at the Pall Corporation. Two of the six alloys were chosen for further investigations based on their performance. Alloy reproducibility and long-term testing of PdAuAg and PdZrAu provided insight to the ability to manufacture these compositions for testing. PdAuAg is the most promising alloy found in this work based on the fabrication reproducibility and resistance to carbon and sulfur. Although PdZrAu had great initial resistance to carbon and sulfur species, the alloy composition has a very narrow range that hindered testing reproducibility.

  19. Reduced graphene oxide with ultrahigh conductivity as carbon coating layer for high performance sulfur@reduced graphene oxide cathode

    NASA Astrophysics Data System (ADS)

    Zhao, Hongbin; Peng, Zhenhuan; Wang, Wenjun; Chen, Xikun; Fang, Jianhui; Xu, Jiaqiang

    2014-01-01

    We developed hydrogen iodide (HI) reduction of rGO and surfactant-assisted chemical reaction- deposition method to form hybrid material of sulfur (S) encapsulated in reduced graphene oxide (rGO) sheets for rechargeable lithium batteries. The surfactant-assisted chemical reaction-deposition method strategy provides intimate contact between the S and graphene oxide. Chemical reduced rGO with high conductivity as carbon coating layer prevented the dissolution of polysulfide ions and improved the electron transfer. This novel core-shell structured S@rGO composites with high S content showed high reversible capacity, good discharge capacity retention and enhanced rate capability used as cathodes in rechargeable Li/S cells. We demonstrated here that an electrode prepared from a S@rGO with up to 85 wt% S maintains a stable discharge capacity of about 980 mAh g-1 at 0.05 C and 570 mAh g-1 at 1C after 200 cycles charge/discharge. These results emphasize the importance of rGO with high electrical conductivity after HI-reduced rGO homogeneously coating on the surface of S, therefore, effectively alleviating the shuttle phenomenon of polysulfides in organic electrolyte. Our surfactant-assisted chemical reaction-HI reduction approach should offer a new technique for the design and synthesis of battery electrodes based on highly conducting carbon materials.

  20. A flatter gallium profile for high-efficiency Cu(In,Ga)(Se,S)2 solar cell and improved robustness against sulfur-gradient variation

    NASA Astrophysics Data System (ADS)

    Huang, Chien-Yao; Lee, Wen-Chin; Lin, Albert

    2016-09-01

    . Finally, an exploratory path toward 20% high-efficiency Ga-profile with robustness against sulfur-induced performance variability is presented.

  1. Sulfur Volcanoes on Io?

    NASA Technical Reports Server (NTRS)

    Greeley, R.; Fink, J.

    1985-01-01

    The unusual rheological properties of molten sulfur, in which viscosity decreases approximately four orders of magnitude as it cools from 170 to 120 C, may result in distinctive volcanic flow morphologies that allow sulfur flows and volcanoes to be identified on Io. Search of high resolution Voyager images reveals three features--Atar Patera, Daedalus Patera, and Kibero Patera--considered to be possible sulfur volcanoes based on their morphology. All three average 250 km in diameter and are distinguished by circular-to-oval central masses surrounded by irregular, widespread flows. Geometric relations indicate that the flows were emplaced after the central zone and appear to have emanated from their margins. The central zones are interpreted to be domes representing the high temperature stage of sulfur formed initially upon eruption. Rapid quenching formed a crust which preserved this phase of the emplacement. Upon cooling to 170 C, the sulfur reached a low viscosity runny stage and was released as the thin, widespread flows.

  2. Sulfur-doped ordered mesoporous carbons: A stability-improving sulfur host for lithium-sulfur battery cathodes

    NASA Astrophysics Data System (ADS)

    Nitze, Florian; Fossum, Kjell; Xiong, Shizhao; Matic, Aleksandar; Palmqvist, Anders E. C.

    2016-06-01

    We report on sulfur-functionalized ordered mesoporous carbons aimed for lithium-sulfur battery electrode applications with improved charge capacity retention. The carbons were obtained by a hard-template strategy using a mixture of furfuryl alcohol and furfuryl mercaptan. For the application as electrode material in lithium-sulfur batteries, the carbons were additionally loaded with sulfur following a traditional melt-diffusion approach. It was found that the sulfur interacts stronger with the sulfur-functionalized carbon matrix than with the non-functionalized material. Electrodes showed very high capacity in the second discharge-charge cycle amounting to approximately 1500, 1200 and 1400 mAh/g (sulfur) for carbon materials with no, medium and high degrees of sulfur functionalization, respectively. More importantly, the sulfur-functionalization of the carbon was found to increase the capacity retention after 50 discharge-charge cycles by 8 and 5% for the carbons with medium and high degrees of sulfur-functionalization, respectively, compared to carbon with no sulfur-functionalization. We attribute this significant improvement to the presence of covalently bound sulfur groups at the internal surface of the functionalized carbon providing efficient anchoring sites for catenation to the sulfur loaded into the pores of the carbons and provide experimental support for this in the form of results from cyclic voltammetry and X-ray photoelectron spectroscopy.

  3. A novel quasi-solid state electrolyte with highly effective polysulfide diffusion inhibition for lithium-sulfur batteries.

    PubMed

    Zhong, Hai; Wang, Chunhua; Xu, Zhibin; Ding, Fei; Liu, Xinjiang

    2016-01-01

    Polymer solid state electrolytes are actively sought for their potential application in energy storage devices, particularly lithium metal rechargeable batteries. Herein, we report a polymer with high concentration salts as a quasi-solid state electrolyte used for lithium-sulfur cells, which shows an ionic conductivity of 1.6 mS cm(-1) at room temperature. The cycling performance of Li-S battery with this electrolyte shows a long cycle life (300 cycles) and high coulombic efficiency (>98%), without any consuming additives in the electrolyte. Moreover, it also shows a remarkably decreased self-discharge (only 0.2%) after storage for two weeks at room temperature. The reason can be attributed to that the electrolyte can suppress polysulfide anions diffusion, due to the high ratio oxygen atoms with negative charges which induce an electrical repulsion to the polysulfide anions, and their relatively long chains which can provide additional steric hindrance. Thus, the polysulfide anions can be located around carbon particles, which result in remarkably improved overall electrochemical performance, and also the electrolyte have a function of suppress the formation of lithium dendrites on the lithium anode surface. PMID:27146645

  4. A novel quasi-solid state electrolyte with highly effective polysulfide diffusion inhibition for lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Zhong, Hai; Wang, Chunhua; Xu, Zhibin; Ding, Fei; Liu, Xinjiang

    2016-05-01

    Polymer solid state electrolytes are actively sought for their potential application in energy storage devices, particularly lithium metal rechargeable batteries. Herein, we report a polymer with high concentration salts as a quasi-solid state electrolyte used for lithium-sulfur cells, which shows an ionic conductivity of 1.6 mS cm‑1 at room temperature. The cycling performance of Li-S battery with this electrolyte shows a long cycle life (300 cycles) and high coulombic efficiency (>98%), without any consuming additives in the electrolyte. Moreover, it also shows a remarkably decreased self-discharge (only 0.2%) after storage for two weeks at room temperature. The reason can be attributed to that the electrolyte can suppress polysulfide anions diffusion, due to the high ratio oxygen atoms with negative charges which induce an electrical repulsion to the polysulfide anions, and their relatively long chains which can provide additional steric hindrance. Thus, the polysulfide anions can be located around carbon particles, which result in remarkably improved overall electrochemical performance, and also the electrolyte have a function of suppress the formation of lithium dendrites on the lithium anode surface.

  5. A novel quasi-solid state electrolyte with highly effective polysulfide diffusion inhibition for lithium-sulfur batteries

    PubMed Central

    Zhong, Hai; Wang, Chunhua; Xu, Zhibin; Ding, Fei; Liu, Xinjiang

    2016-01-01

    Polymer solid state electrolytes are actively sought for their potential application in energy storage devices, particularly lithium metal rechargeable batteries. Herein, we report a polymer with high concentration salts as a quasi-solid state electrolyte used for lithium-sulfur cells, which shows an ionic conductivity of 1.6 mS cm−1 at room temperature. The cycling performance of Li-S battery with this electrolyte shows a long cycle life (300 cycles) and high coulombic efficiency (>98%), without any consuming additives in the electrolyte. Moreover, it also shows a remarkably decreased self-discharge (only 0.2%) after storage for two weeks at room temperature. The reason can be attributed to that the electrolyte can suppress polysulfide anions diffusion, due to the high ratio oxygen atoms with negative charges which induce an electrical repulsion to the polysulfide anions, and their relatively long chains which can provide additional steric hindrance. Thus, the polysulfide anions can be located around carbon particles, which result in remarkably improved overall electrochemical performance, and also the electrolyte have a function of suppress the formation of lithium dendrites on the lithium anode surface. PMID:27146645

  6. A novel quasi-solid state electrolyte with highly effective polysulfide diffusion inhibition for lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Zhong, Hai; Wang, Chunhua; Xu, Zhibin; Ding, Fei; Liu, Xinjiang

    2016-05-01

    Polymer solid state electrolytes are actively sought for their potential application in energy storage devices, particularly lithium metal rechargeable batteries. Herein, we report a polymer with high concentration salts as a quasi-solid state electrolyte used for lithium-sulfur cells, which shows an ionic conductivity of 1.6 mS cm-1 at room temperature. The cycling performance of Li-S battery with this electrolyte shows a long cycle life (300 cycles) and high coulombic efficiency (>98%), without any consuming additives in the electrolyte. Moreover, it also shows a remarkably decreased self-discharge (only 0.2%) after storage for two weeks at room temperature. The reason can be attributed to that the electrolyte can suppress polysulfide anions diffusion, due to the high ratio oxygen atoms with negative charges which induce an electrical repulsion to the polysulfide anions, and their relatively long chains which can provide additional steric hindrance. Thus, the polysulfide anions can be located around carbon particles, which result in remarkably improved overall electrochemical performance, and also the electrolyte have a function of suppress the formation of lithium dendrites on the lithium anode surface.

  7. Strong lithium polysulfide chemisorption on electroactive sites of nitrogen-doped carbon composites for high-performance lithium-sulfur battery cathodes.

    PubMed

    Song, Jiangxuan; Gordin, Mikhail L; Xu, Terrence; Chen, Shuru; Yu, Zhaoxin; Sohn, Hiesang; Lu, Jun; Ren, Yang; Duan, Yuhua; Wang, Donghai

    2015-03-27

    Despite the high theoretical capacity of lithium-sulfur batteries, their practical applications are severely hindered by a fast capacity decay, stemming from the dissolution and diffusion of lithium polysulfides in the electrolyte. A novel functional carbon composite (carbon-nanotube-interpenetrated mesoporous nitrogen-doped carbon spheres, MNCS/CNT), which can strongly adsorb lithium polysulfides, is now reported to act as a sulfur host. The nitrogen functional groups of this composite enable the effective trapping of lithium polysulfides on electroactive sites within the cathode, leading to a much improved electrochemical performance (1200 mAh g(-1) after 200 cycles). The enhancement in adsorption can be attributed to the chemical bonding of lithium ions by nitrogen functional groups in the MNCS/CNT framework. Furthermore, the micrometer-sized spherical structure of the material yields a high areal capacity (ca. 6 mAh cm(-2)) with a high sulfur loading of approximately 5 mg cm(-2), which is ideal for practical applications of the lithium-sulfur batteries.

  8. Strong Lithium Polysulfide Chemisorption on Electroactive Sites of Nitrogen-Doped Carbon Composites For High-Performance Lithium-Sulfur Battery Cathodes

    SciTech Connect

    Song, Jiangxuan; Gordin, Mikhail L.; Xu, Terrence; Chen, Shuru; Yu, Zhaoxin; Sohn, Hiesang; Lu, Jun; Ren, Yang; Duan, Yuhua; Wang, Donghai

    2015-03-27

    Despite the high theoretical capacity of lithium–sulfur batteries, their practical applications are severely hindered by a fast capacity decay, stemming from the dissolution and diffusion of lithium polysulfides in the electrolyte. A novel functional carbon composite (carbon-nanotube-interpenetrated mesoporous nitrogen-doped carbon spheres, MNCS/CNT), which can strongly adsorb lithium polysulfides, is now reported to act as a sulfur host. The nitrogen functional groups of this composite enable the effective trapping of lithium polysulfides on electroactive sites within the cathode, leading to a much improved electrochemical performance (1200 mAhg-1after 200 cycles). The enhancement in adsorption can be attributed to the chemical bonding of lithium ions by nitrogen functional groups in the MNCS/CNT framework. Furthermore, the micrometer-sized spherical structure of the material yields a high areal capacity (ca.6 mAhcm-2) with a high sulfur loading of approximately 5 mgcm-2, which is ideal for practical applications of the lithium–sulfur batteries.

  9. Strong Lithium Polysulfide Chemisorption on Electroactive Sites of Nitrogen-Doped Carbon Composites For High-Performance Lithium–Sulfur Battery Cathodes

    SciTech Connect

    Song, Jiangxuan; Gordin, Mikhail; Xu, Terrence; Chen, Shuru; Yu, Zhaoxin; Sohn, Hiesang; Lu, Jun; Ren, Yang; Duan, Yuhua; wang, Donghai

    2015-03-27

    Despite the high theoretical capacity of lithium–sulfur batteries, their practical applications are severely hindered by a fast capacity decay, stemming from the dissolution and diffusion of lithium polysulfides in the electrolyte. A novel functional carbon composite (carbon-nanotube-interpenetrated mesoporous nitrogen-doped carbon spheres, MNCS/CNT), which can strongly adsorb lithium polysulfides, is now reported to act as a sulfur host. The nitrogen functional groups of this composite enable the effective trapping of lithium polysulfides on electroactive sites within the cathode, leading to a much improved electrochemical performance (1200 mAh g-1 after 200 cycles). The enhancement in adsorption can be attributed to the chemical bonding of lithium ions by nitrogen functional groups in the MNCS/CNT framework. Furthermore, the micrometer-sized spherical structure of the material yields a high areal capacity (ca. 6 mAh cm-2) with a high sulfur loading of approximately 5 mg cm-2, which is ideal for practical applications of the lithium–sulfur batteries.

  10. High-Performance All-Solid-State Lithium-Sulfur Battery Enabled by a Mixed-Conductive Li2S Nanocomposite.

    PubMed

    Han, Fudong; Yue, Jie; Fan, Xiulin; Gao, Tao; Luo, Chao; Ma, Zhaohui; Suo, Liumin; Wang, Chunsheng

    2016-07-13

    All-solid-state lithium-sulfur batteries (ASSLSBs) using highly conductive sulfide-based solid electrolytes suffer from low sulfur utilization, poor cycle life, and low rate performance due to the huge volume change of the electrode and the poor electronic and ionic conductivities of S and Li2S. The most promising approach to mitigate these challenges lies in the fabrication of a sulfur nanocomposite electrode consisting of a homogeneous distribution of nanosized active material, solid electrolyte, and carbon. Here, we reported a novel bottom-up method to synthesize such a nanocomposite by dissolving Li2S as the active material, polyvinylpyrrolidone (PVP) as the carbon precursor, and Li6PS5Cl as the solid electrolyte in ethanol, followed by a coprecipitation and high-temperature carbonization process. Li2S active material and Li6PS5Cl solid electrolyte with a particle size of ∼4 nm were uniformly confined in a nanoscale carbon matrix. The homogeneous nanocomposite electrode consisting of different nanoparticles with distinct properties of lithium storage capability, mechanical reinforcement, and ionic and electronic conductivities enabled a mechanical robust and mixed conductive (ionic and electronic conductive) sulfur electrode for ASSLSB. A large reversible capacity of 830 mAh/g (71% utilization of Li2S) at 50 mA/g for 60 cycles with a high rate performance was achieved at room temperature even at a high loading of Li2S (∼3.6 mg/cm(2)). This work provides a new strategy to design a mechanically robust, mixed conductive nanocomposite electrode for high-performance all-solid-state lithium sulfur batteries.

  11. High-Performance All-Solid-State Lithium-Sulfur Battery Enabled by a Mixed-Conductive Li2S Nanocomposite.

    PubMed

    Han, Fudong; Yue, Jie; Fan, Xiulin; Gao, Tao; Luo, Chao; Ma, Zhaohui; Suo, Liumin; Wang, Chunsheng

    2016-07-13

    All-solid-state lithium-sulfur batteries (ASSLSBs) using highly conductive sulfide-based solid electrolytes suffer from low sulfur utilization, poor cycle life, and low rate performance due to the huge volume change of the electrode and the poor electronic and ionic conductivities of S and Li2S. The most promising approach to mitigate these challenges lies in the fabrication of a sulfur nanocomposite electrode consisting of a homogeneous distribution of nanosized active material, solid electrolyte, and carbon. Here, we reported a novel bottom-up method to synthesize such a nanocomposite by dissolving Li2S as the active material, polyvinylpyrrolidone (PVP) as the carbon precursor, and Li6PS5Cl as the solid electrolyte in ethanol, followed by a coprecipitation and high-temperature carbonization process. Li2S active material and Li6PS5Cl solid electrolyte with a particle size of ∼4 nm were uniformly confined in a nanoscale carbon matrix. The homogeneous nanocomposite electrode consisting of different nanoparticles with distinct properties of lithium storage capability, mechanical reinforcement, and ionic and electronic conductivities enabled a mechanical robust and mixed conductive (ionic and electronic conductive) sulfur electrode for ASSLSB. A large reversible capacity of 830 mAh/g (71% utilization of Li2S) at 50 mA/g for 60 cycles with a high rate performance was achieved at room temperature even at a high loading of Li2S (∼3.6 mg/cm(2)). This work provides a new strategy to design a mechanically robust, mixed conductive nanocomposite electrode for high-performance all-solid-state lithium sulfur batteries. PMID:27322663

  12. Effect of biomass-sulfur interaction on ash composition and agglomeration for the co-combustion of high-sulfur lignite coals and olive cake in a circulating fluidized bed combustor.

    PubMed

    Varol, Murat; Atimtay, Aysel T

    2015-12-01

    This study aimed to investigate the effect of biomass-sulfur interaction on ash composition and agglomeration for the co-combustion of high-sulfur lignite coals and olive cake in a circulating fluidized bed combustor. The tests included co-combustion of 50-50% by wt. mixtures of Bursa-Orhaneli lignite+olive cake and Denizli-Kale lignite+olive cake, with and without limestone addition. Ash samples were subjected to XRF, XRD and SEM/EDS analyses. While MgO was high in the bottom ash for Bursa-Orhaneli lignite and olive cake mixture, Al2O3 was high for Denizli-Kale lignite and olive cake mixture. Due to high Al2O3 content, Muscovite was the dominant phase in the bottom ash of Denizli Kale. CaO in the bottom ash has increased for both fuel mixtures due to limestone addition. K was in Arcanite phase in the co-combustion test of Bursa/Orhaneli lignite and olive cake, however, it mostly appeared in Potassium Calcium Sulfate phase with limestone addition.

  13. HIGH ARSENIC CONCENTRATIONS AND ENRICHED SULFUR AND OXYGEN ISOTOPES IN A FRACTURED-BEDROCK GROUND-WATER SYSTEM

    EPA Science Inventory

    Elevated arsenic concentrations are coincident with enriched sulfur and oxygen isotopes of sulfate in bedrock ground water within Kelly's Cove watershed, Northport, Maine, USA. Interpretation of the data is complicated by the lack of correlations between sulfate concentrations an...

  14. High yield production of sugars from deproteinated palm kernel cake under microwave irradiation via dilute sulfuric acid hydrolysis.

    PubMed

    Fan, Suet-Pin; Jiang, Li-Qun; Chia, Chin-Hua; Fang, Zhen; Zakaria, Sarani; Chee, Kah-Leong

    2014-02-01

    Recent years, great interest has been devoted to the conversion of biomass-derived carbohydrate into sugars, such as glucose, mannose and fructose. These are important versatile intermediate products that are easily processed into high value-added biofuels. In this work, microwave-assisted dilute sulfuric acid hydrolysis of deproteinated palm kernel cake (DPKC) was systematically studied using Response Surface Methodology. The highest mannose yield (92.11%) was achieved at the optimized condition of 148°C, 0.75N H2SO4, 10min 31s and substrate to solvent (SS) ratio (w/v) of 1:49.69. Besides that, total fermentable sugars yield (77.11%), was obtained at 170°C, 0.181N H2SO4, 6min 6s and SS ratio (w/v) of 1:40. Ridge analysis was employed to further verify the optimum conditions. Thus, this work provides fundamental data of the practical use of DPKC as low cost, high yield and environmental-friendly material for the production of mannose and other sugars.

  15. Density and Sound Velocity of Iron-Sulfur Alloying Liquids at High Pressures and Implications to Planetary Cores

    SciTech Connect

    Jing, Z.; Wang, Y.; Yu, T.; Sakamaki, T.; Kono, Y.; Park, C.

    2012-04-30

    Liquid Fe-light element alloys are likely present in the Earth's outer core and the cores (or outer cores) of other terrestrial planets such as Moon, Mercury, and Mars, suggested by geophysical and geochemical observations. In order to determine the abundances of light elements and their effects on the structure, dynamics, and evolution of planetary cores, it is crucial to determine the equation of state for Fe-light element alloying liquids under core conditions. However, density data on liquid Fe-light element alloys at core pressures are very limited and no sound velocity or bulk modulus data are available for these liquids at high pressures. This makes it difficult to extrapolate the equation of state to core pressures. As a result, density data on solid Fe alloys are often used in the literature to compare with seismological observations by making rough corrections for the volume of melting. In this study, we determine the density and sound velocity for Fe-S liquids with different sulfur contents at high pressure and temperature conditions up to 8 GPa and 2173 K using synchrotron X-ray techniques.

  16. Near-Zero Emissions Oxy-Combustion Flue Gas Purification Task 2: SOx/Nox/Hg Removal for High Sulfur Coal

    SciTech Connect

    Nick Degenstein; Minish Shah; Doughlas Louie

    2012-05-01

    The goal of this project is to develop a near-zero emissions flue gas purification technology for existing PC (pulverized coal) power plants that are retrofitted with oxy-combustion technology. The objective of Task 2 of this project was to evaluate an alternative method of SOx, NOx and Hg removal from flue gas produced by burning high sulfur coal in oxy-combustion power plants. The goal of the program was not only to investigate a new method of flue gas purification but also to produce useful acid byproduct streams as an alternative to using a traditional FGD and SCR for flue gas processing. During the project two main constraints were identified that limit the ability of the process to achieve project goals. 1) Due to boiler island corrosion issues >60% of the sulfur must be removed in the boiler island with the use of an FGD. 2) A suitable method could not be found to remove NOx from the concentrated sulfuric acid product, which limits sale-ability of the acid, as well as the NOx removal efficiency of the process. Given the complexity and safety issues inherent in the cycle it is concluded that the acid product would not be directly saleable and, in this case, other flue gas purification schemes are better suited for SOx/NOx/Hg control when burning high sulfur coal, e.g. this project's Task 3 process or a traditional FGD and SCR.

  17. Processes for preparing carbon fibers using sulfur trioxide in a halogenated solvent

    SciTech Connect

    Patton, Jasson T.; Barton, Bryan E.; Bernius, Mark T.; Chen, Xiaoyun; Hukkanen, Eric J.; Rhoton, Christina A.; Lysenko, Zenon

    2015-12-29

    Disclosed here are processes for preparing carbonized polymers (preferably carbon fibers), comprising sulfonating a polymer with a sulfonating agent that comprises SO.sub.3 dissolved in a solvent to form a sulfonated polymer; treating the sulfonated polymer with a heated solvent, wherein the temperature of the solvent is at least 95.degree. C.; and carbonizing the resulting product by heating it to a temperature of 500-3000.degree. C. Carbon fibers made according to these methods are also disclosed herein.

  18. Effect of n-propylthiouracil or thyroxine on arsenic trioxide toxicity in the liver of rat.

    PubMed

    Allen, Tanu; Rana, Suresh Vir Singh

    2007-01-01

    Involvement of thyroid gland in the hepatotoxic manifestations of arsenic trioxide (As(III)) has been studied in rat. The effects of n-propylthiouracil (PTU) (a thyrotoxic compound) and L-thyroxine (a thyroid hormone) have been studied with reference to T(3) and T(4) values in the serum, arsenic concentration in the liver, Ca(2+) accumulation in the liver, aspartate transaminase, alanine transaminase and bilirubin values as the indicators of liver function, histopathological observations and finally the ultrastructural studies. It is concluded that hypothyroid condition protects against As(III) toxicity. Scavenging of reactive oxygen species (ROS) that significantly contribute in As(III) toxicity, by high intracellular concentration of reduced glutathione, as a consequence of PTU treatment is proposed as the plausible protective mechanism.

  19. Rational Design of Cathode Structure for High Rate Performance Lithium-Sulfur Batteries.

    PubMed

    Chen, Hongwei; Wang, Changhong; Dai, Yafei; Qiu, Shengqiang; Yang, Jinlong; Lu, Wei; Chen, Liwei

    2015-08-12

    Practical applications of Li-S batteries require not only high specific capacities and long cycle lifetimes but also high rate performance. We report a rationally designed Li-S cathode, which consists of a freestanding composite thin film assembled from S nanoparticles, reduced graphene oxide (rGO), and a multifunctional additive poly(anthraquinonyl sulfide) (PAQS). The S nanoparticles provide a high initial specific capacity, and the layered and porous rGO structure provides electron and ion transport paths and restricts polysulfide shuttling. PAQS is not only a highly efficient sulfide trapping agent but also an excellent Li(+) conductor, which benefits the battery reaction kinetics at a high rate. The resulting cathode exhibits an initial specific capacity of 1255 mAh g(-1) with a decay rate as low as 0.046% per cycles over 1200 cycles. Importantly, it displays a reversible capacity of 615 mAh g(-1) when discharged at a high rate of 8 C (13.744 A g(-1)). PMID:26148126

  20. Two stage sorption of sulfur compounds

    SciTech Connect

    Moore, W.E.

    1991-12-31

    A two stage method for reducing the sulfur content of exhaust gases is disclosed. Alkali- or alkaline-earth-based sorbent is totally or partially vaporized 10 and introduced into a sulfur-containing gas stream. The activated sorbent can be introduced in the reaction zone or the exhaust gases of a combustor or a gasifier. High efficiencies of sulfur removal can be achieved.

  1. Two stage sorption of sulfur compounds

    DOEpatents

    Moore, William E.

    1992-01-01

    A two stage method for reducing the sulfur content of exhaust gases is disclosed. Alkali- or alkaline-earth-based sorbent is totally or partially vaporized and introduced into a sulfur-containing gas stream. The activated sorbent can be introduced in the reaction zone or the exhaust gases of a combustor or a gasifier. High efficiencies of sulfur removal can be achieved.

  2. High Purity Hydrogen Production with In-Situ Carbon Dioxide and Sulfur Capture in a Single Stage Reactor

    SciTech Connect

    Nihar Phalak; Shwetha Ramkumar; Daniel Connell; Zhenchao Sun; Fu-Chen Yu; Niranjani Deshpande; Robert Statnick; Liang-Shih Fan

    2011-07-31

    Enhancement in the production of high purity hydrogen (H{sub 2}) from fuel gas, obtained from coal gasification, is limited by thermodynamics of the water gas shift (WGS) reaction. However, this constraint can be overcome by conducting the WGS in the presence of a CO{sub 2}-acceptor. The continuous removal of CO{sub 2} from the reaction mixture helps to drive the equilibrium-limited WGS reaction forward. Since calcium oxide (CaO) exhibits high CO{sub 2} capture capacity as compared to other sorbents, it is an ideal candidate for such a technique. The Calcium Looping Process (CLP) developed at The Ohio State University (OSU) utilizes the above concept to enable high purity H{sub 2} production from synthesis gas (syngas) derived from coal gasification. The CLP integrates the WGS reaction with insitu CO{sub 2}, sulfur and halide removal at high temperatures while eliminating the need for a WGS catalyst, thus reducing the overall footprint of the hydrogen production process. The CLP comprises three reactors - the carbonator, where the thermodynamic constraint of the WGS reaction is overcome by the constant removal of CO{sub 2} product and high purity H{sub 2} is produced with contaminant removal; the calciner, where the calcium sorbent is regenerated and a sequestration-ready CO{sub 2} stream is produced; and the hydrator, where the calcined sorbent is reactivated to improve its recyclability. As a part of this project, the CLP was extensively investigated by performing experiments at lab-, bench- and subpilot-scale setups. A comprehensive techno-economic analysis was also conducted to determine the feasibility of the CLP at commercial scale. This report provides a detailed account of all the results obtained during the project period.

  3. Apparatus and process for producing particulate sulfur

    SciTech Connect

    Harbolt, B.A.; Howell, D.W.

    1989-09-05

    This patent describes apparatus for producing relatively large, high bulk density sulfur particles from molten sulfur. The apparatus including a means disposed beneath the porous belt for receiving both quenching liquid drained from sulfur particles on the belt and sulfur particles falling from the porous belt which are not discharged onto the second conveyor belt, and including means for recycling the received fallen particles back onto a particle receiving end region of the porous belt.

  4. Melting relations in the iron-sulfur system at ultra-high pressures: Implications for the thermal state of the earth

    SciTech Connect

    Williams, Q.; Jeanloz, R. )

    1990-11-10

    The melting temperatures of FeS-troilite and of a 10 wt % sulfur iron alloy have been measured to pressures of 120 and 90 GPa, respectively. Results document that FeS melts at a temperature of 4,100 ({plus minus}300) K at the pressure of the core-mantle boundary. Eutectic-like behavior persists in the iron-sulfur system to the highest pressures of the measurements, in marked contrast to the solid-solution-like behavior observed at high pressures in the iron-iron oxide system. Iron with 10 wt % sulfur melts at a similar temperature as FeS at core-mantle boundary conditions. If the sole alloying elements of iron within the core are sulfur and oxygen and the outer core is entirely liquid, the minimum temperature at the top of the outer core is 4,900 ({plus minus}400) K. Calculations of mantle geotherms dictate that there must be a temperature increase of between 1,000 and 2,000 K across thermal boundary layers within the mantle. If D{double prime} is compositionally stratified, it could accomodate the bulk of this temperature jump.

  5. Melting relations in the iron-sulfur system at ultra-high pressures - Implications for the thermal state of the earth

    NASA Technical Reports Server (NTRS)

    Williams, Quentin; Jeanloz, Raymond

    1990-01-01

    The melting temperatures of FeS-troilite and of a 10-wt-pct sulfur iron alloy have been measured to pressures of 120 and 90 GPa, respectively. The results document that FeS melts at a temperature of 4100 (+ or - 300) K at the pressure of the core-mantle boundary. Eutecticlike behavior persists in the iron-sulfur system to the highest pressures of measurements, in marked contrast to the solid-solutionlike behavior observed at high pressures in the iron-iron oxide system. Iron with 10-wt-pct sulfur melts at a similar temperature as FeS at core-mantle boundary conditions. If the sole alloying elements of iron within the core are sulfur and oxygen and the outer core is entirely liquid, the minimum temperature at the top of the outer core is 4900 (+ or - 400) K. Calculations of mantle geotherms dictate that there must be a temperature increase of between 1000 and 2000 K across thermal boundary layers within the mantle. If D-double-prime is compositionally stratified, it could accommodate the bulk of this temperature jump.

  6. Sulfur passivation of surface electrons in highly Mg-doped InN

    SciTech Connect

    Linhart, W. M.; Veal, T. D.; Chai, J.; McConville, C. F.; Durbin, S. M.

    2013-09-14

    Electron accumulation with a sheet density greater than 10{sup 13} cm{sup −2} usually occurs at InN surfaces. Here, the effects of treatment with ammonium sulfide ((NH{sub 4}){sub 2}S{sub x}) on the surface electronic properties of highly Mg-doped InN (>4×10{sup 18} cm{sup −3}) have been investigated with high resolution x-ray photoemission spectroscopy. The valence band photoemission spectra show that the surface Fermi level decreases by approximately 0.08 eV with (NH{sub 4}){sub 2}S{sub x} treatment, resulting in a decrease of the downward band bending and up to a 70% reduction in the surface electron sheet density.

  7. Bottom-up, hard template and scalable approaches toward designing nanostructured Li2S for high performance lithium sulfur batteries

    NASA Astrophysics Data System (ADS)

    Chen, Lin; Liu, Yuzi; Dietz-Rago, Nancy; Shaw, Leon L.

    2015-10-01

    Li2S with a high theoretical capacity of 1166 mA h g-1 and the capability to pair with lithium free anodes has drawn much attention for lithium sulfur (Li-S) battery applications. However, the fast battery decay and the low capacity retention due to dissolution of intermediate polysulfides in electrolytes limit its development. Designing a nanosized and nanostructured host for Li2S through facile techniques is one of the ways to alleviate the dissolution and improve Li-S battery performance; nevertheless, it is technically difficult to synthesize nanosized and nanostructured hosts for Li2S because Li2S is highly sensitive to moisture and oxygen. Herein, a novel technique, i.e., a bottom-up, hard template and scalable method, is proposed to engineer nanoLi2S composites with core-shell structures as cathodes of Li-S batteries. The size of the as-prepared nanostructured Li2S is around 100 nm. With the assistance of FETEM, HRTEM and EFTEM elemental mapping, an excellent core-shell structure has been confirmed and the outside carbon shell has a thickness of 20-50 nm, effectively retarding polysulfide outflow and dissolution. A high initial capacity of 915 mA h g-1 at 0.2 C has been achieved upon electrochemical cycling and the battery still has exceptional capacity retention after prolonged 200 cycles with a limited decay of 0.18% per cycle. Also, at 0.5 C the electrode exhibits 60% capacity retention with a long life of 300 cycles. We attribute these good performances to the nano-architecture constructed by the novel and facile method.Li2S with a high theoretical capacity of 1166 mA h g-1 and the capability to pair with lithium free anodes has drawn much attention for lithium sulfur (Li-S) battery applications. However, the fast battery decay and the low capacity retention due to dissolution of intermediate polysulfides in electrolytes limit its development. Designing a nanosized and nanostructured host for Li2S through facile techniques is one of the ways to alleviate

  8. Mortality experience in relation to a measured arsenic trioxide exposure.

    PubMed

    Pinto, S S; Enterline, P E; Henderson, V; Varner, M O

    1977-08-01

    This report examines the mortality experience of 527 men who retired from a copper smelter where they were exposed to airborne arsenic trioxide. Urinary arsenic values of all plant employees were determined in 1973, and the relative arsenic exposure in the various departments of the plant were determined. The relationship of airborne arsenic concentrations to urinary arsenic values was studied in a separate experiment, and the feasibility of using urinary arsenic values as a measure of arsenic exposure was established. The mortality experience of the cohort under study showed them to have a mortality 12.2% higher than was found for males of the same area at the same ages and in the same time period. The excess mortality was due chiefly to respiratory cancer. When the deaths were classified by total lifetime arsenic exposure, the respiratory cancer mortality was linearly related to the amount of exposure. The 1973 figures for arsenic exposure underestimated the exposure of the cohort group by a factor of possibly 10. Evidence was obtained which suggests that after removal from arsenic exposure, the risk of lung cancer declines. Certain of the data which are presented suggests there may be a threshold value for airborne arsenic trioxide exposure below which no adverse effects may be expected.

  9. [Two different clinical cases of acute arsenic trioxide intoxication].

    PubMed

    Magdalan, Jan; Smolarek, Małgorzata; Porebska, Barbara; Zawadzki, Marcin; Dyś, Piotr

    2007-01-01

    This paper describes two different cases of acute suicidal arsenic trioxide intoxication. Case no 1. A 38-year-old man, alcohol abuser, who ingested 4-5 g dental paste, which corresponds to 2.2-2.7 g of pure arsenic trioxide, developed gastritis with vomiting and abdominal pain, but without diarrhea. No cardiovascular collapse or renal failure were observed. The patient developed also symptoms of central nervous system injury (minor left paresis) and transient hepatic impairment. A head CT revealed no pathological changes in the brain. Hepatic disturbance recovered in a few days and the patient could be discharged on the 12 day. Case no 2. A 57-year-old man, who ingested few grams of pure arsenic developed vomiting, abdominal pain and severe diarrhea. Cardiovascular collapse as a result of intravascular volume depletion, vasodilatation and myocardial dysfunction was observed. The patient died on the first day of hospitalization. In both cases treatment included gastric lavage, BAL therapy, haemodialysis and supportive measures.

  10. The synthesis of nitrogen/sulfur co-doped TiO2 nanocrystals with a high specific surface area and a high percentage of {001} facets and their enhanced visible-light photocatalytic performance

    PubMed Central

    2012-01-01

    Nitrogen/sulfur co-doped anatase TiO2 nanocrystals with a high specific surface area and a high percentage of {001} facets were synthesized by a solvent-thermal process followed by the calcination with thiourea at an optimum heat treatment temperature. Under current experimental conditions, the optimum heat treatment temperature was found at 300°C, which successfully introduced nitrogen and sulfur dopants into the anatase lattice to replace a small portion of oxygen atoms while preserving the geometry of these anatase TiO2 nanocrystals to maintain a high percentage of {001} facets. These nitrogen/sulfur co-doped anatase TiO2 nanocrystals demonstrated a largely enhanced light absorption in the whole visible-light range and exhibited much higher photocatalytic performance than both P25 TiO2 nanoparticles and anatase TiO2 nanocrystals with a high percentage of {001} facets under visible-light illumination. PMID:23095371

  11. Bottom-up, hard template and scalable approaches toward designing nanostructured Li2S for high performance lithium sulfur batteries.

    PubMed

    Chen, Lin; Liu, Yuzi; Dietz-Rago, Nancy; Shaw, Leon L

    2015-11-21

    Li2S with a high theoretical capacity of 1166 mA h g(-1) and the capability to pair with lithium free anodes has drawn much attention for lithium sulfur (Li-S) battery applications. However, the fast battery decay and the low capacity retention due to dissolution of intermediate polysulfides in electrolytes limit its development. Designing a nanosized and nanostructured host for Li2S through facile techniques is one of the ways to alleviate the dissolution and improve Li-S battery performance; nevertheless, it is technically difficult to synthesize nanosized and nanostructured hosts for Li2S because Li2S is highly sensitive to moisture and oxygen. Herein, a novel technique, i.e., a bottom-up, hard template and scalable method, is proposed to engineer nanoLi2S composites with core-shell structures as cathodes of Li-S batteries. The size of the as-prepared nanostructured Li2S is around 100 nm. With the assistance of FETEM, HRTEM and EFTEM elemental mapping, an excellent core-shell structure has been confirmed and the outside carbon shell has a thickness of 20-50 nm, effectively retarding polysulfide outflow and dissolution. A high initial capacity of 915 mA h g(-1) at 0.2 C has been achieved upon electrochemical cycling and the battery still has exceptional capacity retention after prolonged 200 cycles with a limited decay of 0.18% per cycle. Also, at 0.5 C the electrode exhibits 60% capacity retention with a long life of 300 cycles. We attribute these good performances to the nano-architecture constructed by the novel and facile method. PMID:26420373

  12. Bottom-up, hard template and scalable approaches toward designing nanostructured Li2S for high performance lithium sulfur batteries.

    PubMed

    Chen, Lin; Liu, Yuzi; Dietz-Rago, Nancy; Shaw, Leon L

    2015-11-21

    Li2S with a high theoretical capacity of 1166 mA h g(-1) and the capability to pair with lithium free anodes has drawn much attention for lithium sulfur (Li-S) battery applications. However, the fast battery decay and the low capacity retention due to dissolution of intermediate polysulfides in electrolytes limit its development. Designing a nanosized and nanostructured host for Li2S through facile techniques is one of the ways to alleviate the dissolution and improve Li-S battery performance; nevertheless, it is technically difficult to synthesize nanosized and nanostructured hosts for Li2S because Li2S is highly sensitive to moisture and oxygen. Herein, a novel technique, i.e., a bottom-up, hard template and scalable method, is proposed to engineer nanoLi2S composites with core-shell structures as cathodes of Li-S batteries. The size of the as-prepared nanostructured Li2S is around 100 nm. With the assistance of FETEM, HRTEM and EFTEM elemental mapping, an excellent core-shell structure has been confirmed and the outside carbon shell has a thickness of 20-50 nm, effectively retarding polysulfide outflow and dissolution. A high initial capacity of 915 mA h g(-1) at 0.2 C has been achieved upon electrochemical cycling and the battery still has exceptional capacity retention after prolonged 200 cycles with a limited decay of 0.18% per cycle. Also, at 0.5 C the electrode exhibits 60% capacity retention with a long life of 300 cycles. We attribute these good performances to the nano-architecture constructed by the novel and facile method.

  13. High sulfur content polymer nanoparticles obtained from interfacial polymerization of sodium polysulfide and 1,2,3-trichloropropane in water.

    PubMed

    Lim, Jeewoo; Jung, Unho; Joe, Won Tae; Kim, Eui Tae; Pyun, Jeffrey; Char, Kookheon

    2015-06-01

    Sulfur-rich materials have recently attracted keen interest for their potentials in optical, electrochemical, and pesticidal applications as well as their utility in dynamic covalent bond chemistry. Many sulfur-rich polymers, however, are insoluble and processing methods are therefore very limited. The synthesis and characterization of water-dispersible polymer nanoparticles (NPs) with the sulfur content exceeding 75% by weight, obtained from the interfacial polymerization between 1,2,3-trichloropropane and sodium polysulfide in water is reported here. The interfacial polymerization yields well-defined sulfur-rich NPs in the presence of surfactants, which are capable of serving a dual role as a phase transfer catalyst on top of emulsifiers. Such dual role allows for the control of the product NP size by varying its concentration. The surfactants can be easily removed by centrifugation and redispersion in water is also reported here. The resulting sulfur-rich NPs are characterized through elemental analysis, dynamic light scattering, ζ-potential measurements, and scanning electron microscopy. PMID:25847485

  14. High sulfur content polymer nanoparticles obtained from interfacial polymerization of sodium polysulfide and 1,2,3-trichloropropane in water.

    PubMed

    Lim, Jeewoo; Jung, Unho; Joe, Won Tae; Kim, Eui Tae; Pyun, Jeffrey; Char, Kookheon

    2015-06-01

    Sulfur-rich materials have recently attracted keen interest for their potentials in optical, electrochemical, and pesticidal applications as well as their utility in dynamic covalent bond chemistry. Many sulfur-rich polymers, however, are insoluble and processing methods are therefore very limited. The synthesis and characterization of water-dispersible polymer nanoparticles (NPs) with the sulfur content exceeding 75% by weight, obtained from the interfacial polymerization between 1,2,3-trichloropropane and sodium polysulfide in water is reported here. The interfacial polymerization yields well-defined sulfur-rich NPs in the presence of surfactants, which are capable of serving a dual role as a phase transfer catalyst on top of emulsifiers. Such dual role allows for the control of the product NP size by varying its concentration. The surfactants can be easily removed by centrifugation and redispersion in water is also reported here. The resulting sulfur-rich NPs are characterized through elemental analysis, dynamic light scattering, ζ-potential measurements, and scanning electron microscopy.

  15. Process for measuring degradation of sulfur hexafluoride in high voltage systems

    DOEpatents

    Sauers, I.

    1985-04-23

    This invention is a method of detecting the presence of toxic and corrosive by-products in high voltage systems produced by electrically induced degradation of SF/sub 6/ insulating gas in the presence of certain impurities. It is an improvement over previous methods because it is extremely sensitive, detecting by-products present in parts per billion concentrations, and because the device employed is of a simple design and takes advantage of the by-products natural affinity for fluoride ions. The method employs an ion-molecule reaction cell in which negative ions of the by-products are produced by fluorine attachment. These ions are admitted to a negative ion mass spectrometer and identified by their spectra. This spectrometry technique is an improvement over conventional techniques because the negative ion peaks are strong and not obscured by a major ion spectra of the SF/sub 6/ component as is the case in positive ion mass spectrometry.

  16. Process for measuring degradation of sulfur hexafluoride in high voltage systems

    DOEpatents

    Sauers, Isidor

    1986-01-01

    This invention is a method of detecting the presence of toxic and corrosive by-products in high voltage systems produced by electrically induced degradation of SF.sub.6 insulating gas in the presence of certain impurities. It is an improvement over previous methods because it is extremely sensitive, detecting by-products present in parts per billion concentrations, and because the device employed is of a simple design and takes advantage of the by-products natural affinity for fluoride ions. The method employs an ion-molecule reaction cell in which negative ions of the by-products are produced by fluorine attachment. These ions are admitted to a negative ion mass spectrometer and identified by their spectra. This spectrometry technique is an improvement over conventional techniques because the negative ion peaks are strong and not obscured by a major ion spectra of the SF.sub.6 component as is the case in positive ion mass spectrometry.

  17. Ionic liquid-based electrolyte with binary lithium salts for high performance lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Wu, Feng; Zhu, Qizhen; Chen, Renjie; Chen, Nan; Chen, Yan; Ye, Yusheng; Qian, Ji; Li, Li

    2015-11-01

    Rechargeable Li-S batteries have suffered several technical obstacles, such as rapid capacity fading and low coulombic efficiency. To overcome these problems, we design new electrolytes containing N-methoxyethyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)-imide (Pyr1,2O1TFSI) and tri(ethylene glycol)dimethyl ether (TEGDME) in mass ratio of 7:3. Moreover, Lithium difluoro(oxalate)borate (LiODFB) is introduced for the modification. Although the addition of LiODFB as additive lead to extremely high viscosity of electrolyte and inferior performance of the cells, the electrolyte containing lithium bis(trifluoromethanesulfonyl)imide (LiTFSI, 0.84 nm) and LiODFB (0.60 nm) mixture with a total molar concentration of 0.4 mol kg-1 as binary lithium salt shows excellent electrochemical performance. The Pyr1,2O1TFSI/TEGDME electrolyte with LiTFSI/LiODFB binary lithium salts in mole ratio of 6:4 is obtained after optimizing ratio. The Li-S cells containing this electrolyte system show excellent capacity and cycle performance, whose initial discharge capacity is 1264.4 mAh g-1, and retains 911.4 mAh g-1 after 50 cycles with the coulombic efficiency more than 95%. It can be attributed the solid-electrolyte interphase (SEI)-forming ability of LiODFB which protect Li anode from suffering lithium dendrites and prevent the shuttle phenomenon. The novel electrolytes provide good cycling stability and high coulombic efficiency for the Li-S batteries, which is suggested as a promising electrolyte for Li-S batteries.

  18. High concentrations of manganese and sulfur in deposits on Murray Ridge, Endeavour Crater, Mars

    USGS Publications Warehouse

    Arvidson, Raymond E.; Squyres, Steven W.; Morris, Richard V.; Knoll, Andrew H.; Gellert, Ralf; Clark, Benton C.; Catalano, Jeffrey G.; Jolliff, Bradley L.; McLennan, Scott M.; Herkenhoff, Kenneth E.; VanBommel, Scott; Mittelfehldt, David W.; Grotzinger, John P.; Guinness, Edward A.; Johnson, Jeffrey R.; Bell, James F.; Farrand, William H.; Stein, Nathan; Fox, Valerie K.; Golombek, Matthew P.; Hinkle, Margaret A. G.; Calvin, Wendy M.; de Souza, Paulo A.

    2016-01-01

    Mars Reconnaissance Orbiter HiRISE images and Opportunity rover observations of the ~22 km wide Noachian age Endeavour Crater on Mars show that the rim and surrounding terrains were densely fractured during the impact crater-forming event. Fractures have also propagated upward into the overlying Burns formation sandstones. Opportunity’s observations show that the western crater rim segment, called Murray Ridge, is composed of impact breccias with basaltic compositions, as well as occasional fracture-filling calcium sulfate veins. Cook Haven, a gentle depression on Murray Ridge, and the site where Opportunity spent its sixth winter, exposes highly fractured, recessive outcrops that have relatively high concentrations of S and Cl, consistent with modest aqueous alteration. Opportunity’s rover wheels serendipitously excavated and overturned several small rocks from a Cook Haven fracture zone. Extensive measurement campaigns were conducted on two of them: Pinnacle Island and Stuart Island. These rocks have the highest concentrations of Mn and S measured to date by Opportunity and occur as a relatively bright sulfate-rich coating on basaltic rock, capped by a thin deposit of one or more dark Mn oxide phases intermixed with sulfate minerals. We infer from these unique Pinnacle Island and Stuart Island rock measurements that subsurface precipitation of sulfate-dominated coatings was followed by an interval of partial dissolution and reaction with one or more strong oxidants (e.g., O2) to produce the Mn oxide mineral(s) intermixed with sulfate-rich salt coatings. In contrast to arid regions on Earth, where Mn oxides are widely incorporated into coatings on surface rocks, our results demonstrate that on Mars the most likely place to deposit and preserve Mn oxides was in fracture zones where migrating fluids intersected surface oxidants, forming precipitates shielded from subsequent physical erosion.

  19. Novel characterization of Radix Angelicae Dahuricae before and after the sulfur-fumigation process by combining high performance liquid chromatographic fingerprint and multi-ingredients determination

    PubMed Central

    Liu, Xiao; Liu, Jingjing; Cai, Hao; Li, Songlin; Ma, Xiaoqing; Lou, Yajing; Qin, Kunming; Guan, Hongyue; Cai, Baochang

    2014-01-01

    Background: Harmful sulfur-fumigation processing method is abused during Radix Angelicae Dahuricae preparation. However, the analytical technique characterizing Radix Angelicae Dahuricae before and after the sulfur-fumigation process is absent. Materials and Methods: The high performance liquid chromatography (HPLC) technique was adopted to develop methods combining finger-print analysis and multi-ingredients simultaneous determination for quality evaluation of Radix Angelicae Dahuricae before and after the sulfur-fumigation process. The chromatographic fingerprint method was established for qualitative analysis coupled with statistical cluster analysis basing on Euclidean distance. Additionally, a determination method was developed for quantitative analysis, which was able to assay the concentrations of the major coumarins including imperatorin, isoimperatorin, xanthotoxin, xanthotoxol, isoimpinellin, oxypeucedanin, and bergapten in Radix Angelicae Dahuricae simultaneously. The separations of the two methods were both achieved on a Hypersil octadecylsilyl C18 column (250 mm × 4.6 mm, 5 μm) at 35°C under different strategic gradient elution programs. The detection wavelength was set at 254 nm all the time. Method validation data indicated that the methods were both reliable and applicable. They were then used to assay different Radix Angelicae Dahuricae samples collected from good agricultural practice (GAP) bases and local herbal markets. Results: The successful application demonstrated that the combination of HPLC fingerprint and simultaneous quantification of multi-ingredients offers an efficient approach for quality evaluation of Radix Angelicae Dahuricae before and after the sulfur-fumigation process. Conclusion: In order to discriminate Radix Angelicae Dahuricae before and after the sulfur-fumigation process, oxypeucedanin, and xanthotoxol were the most sensitive biomarkers and should be determined. PMID:25210323

  20. Iron-Sulfur Cluster Biogenesis Chaperones: Evidence for Emergence of Mutational Robustness of a Highly Specific Protein-Protein Interaction.

    PubMed

    Delewski, Wojciech; Paterkiewicz, Bogumiła; Manicki, Mateusz; Schilke, Brenda; Tomiczek, Bartłomiej; Ciesielski, Szymon J; Nierzwicki, Lukasz; Czub, Jacek; Dutkiewicz, Rafal; Craig, Elizabeth A; Marszalek, Jaroslaw

    2016-03-01

    Biogenesis of iron-sulfur clusters (FeS) is a highly conserved process involving Hsp70 and J-protein chaperones. However, Hsp70 specialization differs among species. In most eukaryotes, including Schizosaccharomyces pombe, FeS biogenesis involves interaction between the J-protein Jac1 and the multifunctional Hsp70 Ssc1. But, in Saccharomyces cerevisiae and closely related species, Jac1 interacts with the specialized Hsp70 Ssq1, which emerged through duplication of SSC1. As little is known about how gene duplicates affect the robustness of their protein interaction partners, we analyzed the functional and evolutionary consequences of Ssq1 specialization on the ubiquitous J-protein cochaperone Jac1, by comparing S. cerevisiae and S. pombe. Although deletion of JAC1 is lethal in both species, alanine substitutions within the conserved His-Pro-Asp (HPD) motif, which is critical for Jac1:Hsp70 interaction, have species-specific effects. They are lethal in S. pombe, but not in S. cerevisiae. These in vivo differences correlated with in vitro biochemical measurements. Charged residues present in the J-domain of S. cerevisiae Jac1, but absent in S. pombe Jac1, are important for tolerance of S. cerevisiae Jac1 to HPD alterations. Moreover, Jac1 orthologs from species that encode Ssq1 have a higher sequence divergence. The simplest interpretation of our results is that Ssq1's coevolution with Jac1 resulted in expansion of their binding interface, thus increasing the efficiency of their interaction. Such an expansion could in turn compensate for negative effects of HPD substitutions. Thus, our results support the idea that the robustness of Jac1 emerged as consequence of its highly efficient and specific interaction with Ssq1.

  1. Lithium Sulfur Primary Battery with Super High Energy Density: Based on the Cauliflower-like Structured C/S Cathode.

    PubMed

    Ma, Yiwen; Zhang, Hongzhang; Wu, Baoshan; Wang, Meiri; Li, Xianfeng; Zhang, Huamin

    2015-01-01

    The lithium-sulfur primary batteries, as seldom reported in the previous literatures, were developed in this work. In order to maximize its practical energy density, a novel cauliflower-like hierarchical porous C/S cathode was designed, for facilitating the lithium-ions transport and sulfur accommodation. This kind of cathode could release about 1300 mAh g(-1) (S) capacity at sulfur loading of 6 ~ 14 mg cm(-2), and showed excellent shelf stability during a month test at room temperature. As a result, the assembled Li-S soft package battery achieved an energy density of 504 Wh kg(-1) (654 Wh L(-1)), which was the highest value ever reported to the best of our knowledge. This work might arouse the interests on developing primary Li-S batteries, with great potential for practical application. PMID:26456914

  2. Lithium Sulfur Primary Battery with Super High Energy Density: Based on the Cauliflower-like Structured C/S Cathode

    PubMed Central

    Ma, Yiwen; Zhang, Hongzhang; Wu, Baoshan; Wang, Meiri; Li, Xianfeng; Zhang, Huamin

    2015-01-01

    The lithium-sulfur primary batteries, as seldom reported in the previous literatures, were developed in this work. In order to maximize its practical energy density, a novel cauliflower-like hierarchical porous C/S cathode was designed, for facilitating the lithium-ions transport and sulfur accommodation. This kind of cathode could release about 1300 mAh g−1 (S) capacity at sulfur loading of 6 ~ 14 mg cm−2, and showed excellent shelf stability during a month test at room temperature. As a result, the assembled Li-S soft package battery achieved an energy density of 504 Wh kg−1 (654 Wh L−1), which was the highest value ever reported to the best of our knowledge. This work might arouse the interests on developing primary Li-S batteries, with great potential for practical application. PMID:26456914

  3. Lithium Sulfur Primary Battery with Super High Energy Density: Based on the Cauliflower-like Structured C/S Cathode

    NASA Astrophysics Data System (ADS)

    Ma, Yiwen; Zhang, Hongzhang; Wu, Baoshan; Wang, Meiri; Li, Xianfeng; Zhang, Huamin

    2015-10-01

    The lithium-sulfur primary batteries, as seldom reported in the previous literatures, were developed in this work. In order to maximize its practical energy density, a novel cauliflower-like hierarchical porous C/S cathode was designed, for facilitating the lithium-ions transport and sulfur accommodation. This kind of cathode could release about 1300 mAh g-1 (S) capacity at sulfur loading of 6 ~ 14 mg cm-2, and showed excellent shelf stability during a month test at room temperature. As a result, the assembled Li-S soft package battery achieved an energy density of 504 Wh kg-1 (654 Wh L-1), which was the highest value ever reported to the best of our knowledge. This work might arouse the interests on developing primary Li-S batteries, with great potential for practical application.

  4. Hierarchical Carbon with High Nitrogen Doping Level: A Versatile Anode and Cathode Host Material for Long-Life Lithium-Ion and Lithium-Sulfur Batteries.

    PubMed

    Reitz, Christian; Breitung, Ben; Schneider, Artur; Wang, Di; von der Lehr, Martin; Leichtweiss, Thomas; Janek, Jürgen; Hahn, Horst; Brezesinski, Torsten

    2016-04-27

    Nitrogen-rich carbon with both a turbostratic microstructure and meso/macroporosity was prepared by hard templating through pyrolysis of a tricyanomethanide-based ionic liquid in the voids of a silica monolith template. This multifunctional carbon not only is a promising anode candidate for long-life lithium-ion batteries but also shows favorable properties as anode and cathode host material owing to a high nitrogen content (>8% after carbonization at 900 °C). To demonstrate the latter, the hierarchical carbon was melt-infiltrated with sulfur as well as coated by atomic layer deposition (ALD) of anatase TiO2, both of which led to high-quality nanocomposites. TiO2 ALD increased the specific capacity of the carbon while maintaining high Coulombic efficiency and cycle life: the composite exhibited stable performance in lithium half-cells, with excellent recovery of low rate capacities after thousands of cycles at 5C. Lithium-sulfur batteries using the sulfur/carbon composite also showed good cyclability, with reversible capacities of ∼700 mA·h·g(-1) at C/5 and without obvious decay over several hundred cycles. The present results demonstrate that nitrogen-rich carbon with an interconnected multimodal pore structure is very versatile and can be used as both active and inactive electrode material in high-performance lithium-based batteries. PMID:26867115

  5. Demonstration of selective catalytic reduction (SCR) technology for the control of nitrogen oxide (NO sub x ) emissions from high-sulfur coal-fired boilers

    SciTech Connect

    Not Available

    1991-08-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide (NOx) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NOx to convert it to nitrogen and water vapor, Although SCR is widely practiced in Japan and Europe, there are numerous technical uncertainties associated with applying SCR to US coals. These uncertainties include: (1) potential catalyst deactivation due to poisoning by trace metal species present in US coals that are not present in other fuel performance of the technology and effects on the balance-of-plant equipment in the presence of high amounts of SO{sub 2} and SO{sub 3}. (3) performance of a wide variety of SCR catalyst compositions, geometries and methods of manufacture under typical high-sulfur coal-fired utility operating conditions. These uncertainties will be explored by constructing a series of small-scale SCR reactors and simultaneously exposing different SCR catalysts to flue gas derived from the combustion of high sulfur US coal.

  6. Wet Chemistry Synthesis of Multidimensional Nanocarbon-Sulfur Hybrid Materials with Ultrahigh Sulfur Loading for Lithium-Sulfur Batteries.

    PubMed

    Du, Wen-Cheng; Yin, Ya-Xia; Zeng, Xian-Xiang; Shi, Ji-Lei; Zhang, Shuai-Feng; Wan, Li-Jun; Guo, Yu-Guo

    2016-02-17

    An optimized nanocarbon-sulfur cathode material with ultrahigh sulfur loading of up to 90 wt % is realized in the form of sulfur nanolayer-coated three-dimensional (3D) conducting network. This 3D nanocarbon-sulfur network combines three different nanocarbons, as follows: zero-dimensional carbon nanoparticle, one-dimensional carbon nanotube, and two-dimensional graphene. This 3D nanocarbon-sulfur network is synthesized by using a method based on soluble chemistry of elemental sulfur and three types of nanocarbons in well-chosen solvents. The resultant sulfur-carbon material shows a high specific capacity of 1115 mA h g(-1) at 0.02C and good rate performance of 551 mA h g(-1) at 1C based on the mass of sulfur-carbon composite. Good battery performance can be attributed to the homogeneous compositing of sulfur with the 3D hierarchical hybrid nanocarbon networks at nanometer scale, which provides efficient multidimensional transport pathways for electrons and ions. Wet chemical method developed here provides an easy and cost-effective way to prepare sulfur-carbon cathode materials with high sulfur loading for application in high-energy Li-S batteries. PMID:26378622

  7. The role of a conserved tyrosine residue in high-potential iron sulfur proteins.

    PubMed Central

    Iwagami, S. G.; Creagh, A. L.; Haynes, C. A.; Borsari, M.; Felli, I. C.; Piccioli, M.; Eltis, L. D.

    1995-01-01

    Conserved tyrosine-12 of Ectothiorhodospira halophila high-potential iron sulphur protein (HiPIP) iso-I was substituted with phenylalanine (Y12F), histidine (Y12H), tryptophan (Y12W), isoleucine (Y12I), and alanine (Y12A). Variants Y12A and Y12I were expressed to reasonable levels in cells grown at lower temperatures, but decomposed during purification. Variants Y12F, Y12H, and Y12W were substantially destabilized with respect to the recombinant wild-type HiPIP (rcWT) as determined by differential scanning calorimetry over a pH range of 7.0-11.0. Characterization of the Y12F variant by NMR indicates that the principal structural differences between this variant and the rcWT HiPIP result from the loss of the two hydrogen bonds of the Tyr-12 hydroxyl group with Asn-14 O delta 1 and Lys-59 NH, respectively. The effect of the loss of the latter interaction is propagated through the Lys-59/Val-58 peptide bond, thereby perturbing Gly-46. The delta delta GDapp of Y12F of 2.3 kcal/mol with respect to rcWT HiPIP (25 degrees C, pH 7.0) is entirely consistent with the contribution of these two hydrogen bonds to the stability of the latter. CD measurements show that Tyr-12 influences several electronic transitions within the cluster. The midpoint reduction potentials of variants Y12F, Y12H, and Y12W were 17, 19, and 22 mV (20 mM MOPS, 0.2 M sodium chloride, pH 6.98, 25 degrees C), respectively, higher than that of rcWT HiPIP. The current results indicate that, although conserved Tyr-12 modulates the properties of the cluster, its principle function is to stabilize the HiPIP through hydrogen bonds involving its hydroxyl group and electrostatic interactions involving its aromatic ring. PMID:8580847

  8. Meteoritic Sulfur Isotopic Analysis

    NASA Technical Reports Server (NTRS)

    Thiemens, Mark H.

    1996-01-01

    Funds were requested to continue our program in meteoritic sulfur isotopic analysis. We have recently detected a potential nucleosynthetic sulfur isotopic anomaly. We will search for potential carriers. The documentation of bulk systematics and the possible relation to nebular chemistry and oxygen isotopes will be explored. Analytical techniques for delta(sup 33), delta(sup 34)S, delta(sup 36)S isotopic analysis were improved. Analysis of sub milligram samples is now possible. A possible relation between sulfur isotopes and oxygen was detected, with similar group systematics noted, particularly in the case of aubrites, ureilites and entstatite chondrites. A possible nucleosynthetic excess S-33 has been noted in bulk ureilites and an oldhamite separate from Norton County. High energy proton (approximately 1 GeV) bombardments of iron foils were done to experimentally determine S-33, S-36 spallogenic yields for quantitation of isotopic measurements in iron meteorites. Techniques for measurement of mineral separates were perfected and an analysis program initiated. The systematic behavior of bulk sulfur isotopes will continue to be explored.

  9. High Pressure Melting of Iron with Nonmetals Sulfur, Carbon, Oxygen, and Hydrogen: Implications for Planetary Cores

    NASA Astrophysics Data System (ADS)

    Buono, Antonio Salvatore

    The earth's core consists of a solid metallic center surrounded by a liquid metallic outer layer. Understanding the compositions of the inner and outer cores allows us to better understand the dynamics of the earth's core, as well as the dynamics of the cores of other terrestrial planets and moons. The density and size of the earth's core indicate that it is approximately 90% metallic, predominantly iron, with about 10% light elements. Iron meteorites, believed to be the remnants of planetary cores, provide further constraints on the composition of the earth's core, indicating a composition of 86% iron, 4% nickel, and 10% light elements. Any potential candidate for the major light element core component must meet two criteria: first, it must have high cosmic abundances and second, it must be compatible with Fe. Given these two constraints there are five plausible elements that could be the major light element in the core: H, O, C, S, and Si. Of these five possible candidates this thesis focuses on S and C as well exploring the effect of minor amounts of O and H on the eutectic temperature in a Fe-FeS core. We look at two specific aspects of the Fe-FeS system: first, the shape of the liquidus as a function of pressure, second, a possible cause for the reported variations in the eutectic temperature, which draws on the effect of H and O. Finally we look at the effect of S and C on partitioning behavior of Ni, Pt, Re,Co, Os and W between cohenite and metallic liquid. We are interested in constraining the shape of the Fe-FeS liquidus because as a planet with a S-enriched core cools, the thermal and compositional evolution of its core is constrained by this liquidus. In Chapter 1 I present an equation that allows for calculation of the temperature along the liquidus as a function of pressure and composition for Fe-rich compositions and pressures from 1 bar to 10 GPa. One particularly interesting feature of the Fe --rich side of the Fe-FeS eutectic is the sigmoidal shape

  10. Supraglacial sulfur springs and associated biological activity in the Canadian high arctic - signs of life beneath the ice

    USGS Publications Warehouse

    Grasby, Stephen E.; Allen, Carlton C.; Longazo, Teresa G.; Lisle, John T.; Griffin, Dale W.; Beauchamp, Benoit

    2003-01-01

    Unique springs, discharging from the surface of an arctic glacier, release H2S and deposit native sulfur, gypsum, and calcite. The presence of sulfur in three oxidation states indicates a complex series of redox reactions. Physical and chemical conditions of the spring water and surrounding environment, as well as mineralogical and isotopic signatures, suggest biologically mediated reactions. Cell counts and DNA analyses confirm bacteria are present in the spring system, and a limited number of sequenced isolates suggests that complex communities of bacteria live within the glacial system.

  11. Supraglacial Sulfur Springs and Associated Biological Activity in the Canadian High Arctic-Signs of Life Beneath the Ice

    NASA Astrophysics Data System (ADS)

    Grasby, Stephen E.; Allen, Carlton C.; Longazo, Teresa G.; Lisle, John T.; Griffin, Dale W.; Beauchamp, Benoit

    2003-11-01

    Unique springs, discharging from the surface of an arctic glacier, release H2S and deposit native sulfur, gypsum, and calcite. The presence of sulfur in three oxidation states indicates a complex series of redox reactions. Physical and chemical conditions of the spring water and surrounding environment, as well as mineralogical and isotopic signatures, suggest biologically mediated reactions. Cell counts and DNA analyses confirm bacteria are present in the spring system, and a limited number of sequenced isolates suggests that complex communities of bacteria live within the glacial system.

  12. Sulfur: its clinical and toxicologic aspects.

    PubMed

    Komarnisky, Lioudmila A; Christopherson, Robert J; Basu, Tapan K

    2003-01-01

    Although there is no known dietary requirement for inorganic sulfur, it is an essential element for all animal species in as much as they all require the sulfur-containing amino acid methionine. There are three predominate forms of organic sulfur in animals and humans: 1). the thiomethyl of methionine residues in protein; 2). the sulfhydryl disulfides of protein; and 3). the compounds containing ester or amide bound sulfates of glycosaminoglycans, steroids, and many xenobiotic metabolites. Thus, sulfur becomes an important constituent of amino acids, proteins, enzymes, vitamins and other biomolecules. Unlike mammalian species, plants can use inorganic sulfur and synthesize methionine from which are synthesized all the other important sulfur compounds. Hence, sulfur deficiency occurs mainly when plants are grown in sulfur-depleted soils and when humans and animals consume low-protein diets. In recent times, however, the increasing prevalence of refining petroleum and smelting sulfur compounds of metallic minerals into free metals are having a large impact on the balance of sulfur in the environment. Sulfur toxicity is associated mainly with high levels of the element and its toxic volatile substances in the environment. Sulfur dioxide (SO(2)), a major air pollutant, may adversely affect animal and human health by causing bronchitis, bronchoconstriction, and increased pulmonary resistance.

  13. Different B-type methionine sulfoxide reductases in Chlamydomonas may protect the alga against high-light, sulfur-depletion, or oxidative stress.

    PubMed

    Zhao, Lei; Chen, Mei; Cheng, Dongmei; Yang, Haomeng; Sun, Yongle; Zhou, Heyi; Huang, Fang

    2013-11-01

    The genome of unicellular green alga Chlamydomonas reinhardtii contains four genes encoding B-type methionine sulfoxide reductases, MSRB1.1, MSRB1.2, MSRB2.1, and MSRB2.2, with functions largely unknown. To understand the cell defense system mediated by the methionine sulfoxide reductases in Chlamydomonas, we analyzed expression and physiological roles of the MSRBs under different abiotic stress conditions using immunoblotting and quantitative polymerase chain reaction (PCR) analyses. We showed that the MSRB2.2 protein was accumulated in cells treated with high light (1,300 µE/m² per s), whereas MSRB1.1 was accumulated in the cells under 1 mmol/L H₂O₂ treatment or sulfur depletion. We observed that the cells with the MSRB2.2 knockdown and overexpression displayed increased and decreased sensitivity to high light, respectively, based on in situ chlorophyll a fluorescence measures. We also observed that the cells with the MSRB1.1 knockdown and overexpression displayed decreased and increased tolerance to sulfur-depletion and oxidative stresses, respectively, based on growth and H₂-producing performance. The physiological implications revealed from the experimental data highlight the importance of MSRB2.2 and MSRB1.1 in protecting Chlamydomonas cells against adverse conditions such as high-light, sulfur-depletion, and oxidative stresses.

  14. In Situ Polymerized PAN-Assisted S/C Nanosphere with Enhanced High-Power Performance as Cathode for Lithium/Sulfur Batteries.

    PubMed

    Hu, Hao; Cheng, Haoyan; Liu, Zhengfei; Li, Guojian; Zhu, Qianchen; Yu, Ying

    2015-08-12

    Carbonaceous and polymer materials are extensively employed as conductor and container to encapsulate sulfur particles and limit polysulfide dissolution. Even so, high-power performance is still far from satisfaction due to the expansion and collapse of the electrode materials during thousands of charge-discharge process. Herein, it is found that colloidal carbon sphere with high elastic coefficient can be utilized as a framework to load sulfur, which can trap soluble polysulfides species in the pores within the sphere and efficaciously improve the electronic conductivity of the cathode. After modified by polyaniline (PAN) through in situ polymerization, PAN-assisted S/C nanosphere (PSCs-73, with 73 wt % sulfur) effectively minimize polysulfide diffusion, enhance the electron transfer rate and overcome the problem of volume expansion. The fabricated PSCs-73 cell shows outstanding long high-power cycling capability over 2500 charge/discharge cycles with a capacity decay of 0.01% per cycle at 5 C. Substantially, this composite can drive 2.28 W white indicators of LED robustly after minutes of charging by three lithium batteries in series, showing a promising potential application in the future. PMID:26200760

  15. In Situ Polymerized PAN-Assisted S/C Nanosphere with Enhanced High-Power Performance as Cathode for Lithium/Sulfur Batteries.

    PubMed

    Hu, Hao; Cheng, Haoyan; Liu, Zhengfei; Li, Guojian; Zhu, Qianchen; Yu, Ying

    2015-08-12

    Carbonaceous and polymer materials are extensively employed as conductor and container to encapsulate sulfur particles and limit polysulfide dissolution. Even so, high-power performance is still far from satisfaction due to the expansion and collapse of the electrode materials during thousands of charge-discharge process. Herein, it is found that colloidal carbon sphere with high elastic coefficient can be utilized as a framework to load sulfur, which can trap soluble polysulfides species in the pores within the sphere and efficaciously improve the electronic conductivity of the cathode. After modified by polyaniline (PAN) through in situ polymerization, PAN-assisted S/C nanosphere (PSCs-73, with 73 wt % sulfur) effectively minimize polysulfide diffusion, enhance the electron transfer rate and overcome the problem of volume expansion. The fabricated PSCs-73 cell shows outstanding long high-power cycling capability over 2500 charge/discharge cycles with a capacity decay of 0.01% per cycle at 5 C. Substantially, this composite can drive 2.28 W white indicators of LED robustly after minutes of charging by three lithium batteries in series, showing a promising potential application in the future.

  16. Different B-type methionine sulfoxide reductases in Chlamydomonas may protect the alga against high-light, sulfur-depletion, or oxidative stress.

    PubMed

    Zhao, Lei; Chen, Mei; Cheng, Dongmei; Yang, Haomeng; Sun, Yongle; Zhou, Heyi; Huang, Fang

    2013-11-01

    The genome of unicellular green alga Chlamydomonas reinhardtii contains four genes encoding B-type methionine sulfoxide reductases, MSRB1.1, MSRB1.2, MSRB2.1, and MSRB2.2, with functions largely unknown. To understand the cell defense system mediated by the methionine sulfoxide reductases in Chlamydomonas, we analyzed expression and physiological roles of the MSRBs under different abiotic stress conditions using immunoblotting and quantitative polymerase chain reaction (PCR) analyses. We showed that the MSRB2.2 protein was accumulated in cells treated with high light (1,300 µE/m² per s), whereas MSRB1.1 was accumulated in the cells under 1 mmol/L H₂O₂ treatment or sulfur depletion. We observed that the cells with the MSRB2.2 knockdown and overexpression displayed increased and decreased sensitivity to high light, respectively, based on in situ chlorophyll a fluorescence measures. We also observed that the cells with the MSRB1.1 knockdown and overexpression displayed decreased and increased tolerance to sulfur-depletion and oxidative stresses, respectively, based on growth and H₂-producing performance. The physiological implications revealed from the experimental data highlight the importance of MSRB2.2 and MSRB1.1 in protecting Chlamydomonas cells against adverse conditions such as high-light, sulfur-depletion, and oxidative stresses. PMID:24034412

  17. Eddy covariance flux of sulfur dioxide to the sea surface: Air-side resistance to deposition of a highly soluble gas

    NASA Astrophysics Data System (ADS)

    Porter, J.; De Bruyn, W. J.; Miller, S. D.; Saltzman, E. S.

    2014-12-01

    Deposition to the sea surface represents a major atmospheric removal mechanism for sulfur dioxide and many other highly soluble products of tropospheric photochemistry. Such gases include nitric acid, ammonia, organic acids, sulfur dioxide, and highly soluble organic compounds such as methanol and acetone. The deposition of highly soluble gases is controlled by turbulent and diffusive transport on the air side of the air/sea interface. In this study, air/sea fluxes of the soluble gas sulfur dioxide (SO2 ), sensible and latent heat, and momentum were measured using eddy covariance. This was a pilot study carried out in April 2014 on Scripps pier in La Jolla, California, that was designed to assess the potential for measuring SO2 fluxes over the ocean. SO2 was detected using chemical ion mass spectrometry in negative ion mode with a sensitivity of roughly 100 Hz/ppt. The ionization scheme involved addition of ozone to a dried air stream and subsequent conversion of SO2 to the SO5 - ion. The results demonstrate the feasibility of seagoing SO2 flux measurements. Such measurements can be used to constrain the depositional velocities of soluble gases and test models for air-side resistance to air/sea gas transfer.

  18. Uses of lunar sulfur

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

    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.

  19. Catalytic direct liquefaction of high-sulfur coals and their blends with asphaltite in the absence of a solvent

    SciTech Connect

    Omer Gul; Parvana Gafarova; Arif Hesenov; Harold H. Schobert; Oktay Erbatur

    2007-08-15

    Two high-sulfur Turkish coals (Mengen and Kangal) and an asphaltite (Avgamasya) were liquefied with and without the catalyst precursors ammonium heptamolybdate (AHM) and ammonium tetrathiomolybdate (ATTM) at 300, 350, 400, and 450{sup o}C. Blends of these coals with the asphaltite were also liquefied using ATTM. Effective conversions of both coals into oils and into asphaltene and preasphaltene fractions were achieved with both catalyst precursors, although ATTM was more effective than AHM. Maximum conversion for Mengen coal with ATTM (89.2%) was achieved at 400{sup o}C, although the maximum yield of oils (56.9%) was obtained at 450{sup o}C. Kangal, in the presence of ATTM, gave maximum conversion (87.7%) at 400{sup o}C; the corresponding oil yield (49.6%) was not much less than that obtained at 450{sup o}C (49.9%). Some retrogressive reactions toward the formation of aromatics were observed during liquefaction at 450{sup o}C in the presence of AHM or ATTM with both coals. Also, using these catalyst precursors results in effective hydrogenation of two-ring or higher condensed aromatics and effective hydrogenolysis of the alicyclic part of hydroaromatic structures. On the other hand, these catalyst precursors do not provide effective saturation of monoaromatic rings, although the use of ATTM yielded partial reduction of these compounds. The distribution of main product fractions obtained from these reactions and the detailed analysis of oils obtained are reported. 118 refs., 4 figs., 15 tabs.

  20. High sulfur content in corn dried distillers grains with solubles protects against oxidized lipids by increasing sulfur-containing antioxidants in nursery pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Some sources of corn dried distillers grains with solubles (DDGS) contain relatively high amounts of oxidized lipids produced from PUFA peroxidation during the production process. These oxidized lipids may negatively affect growth performance and metabolic oxidation status of pigs. The objective of ...

  1. High sulfur content in dried distillers grains with solubles (DDGS) protects against oxidized lipids in DDGS by increasing sulfur-containing antioxidants in nursery pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Some sources of DDGS contain relatively high amounts of oxidized lipids produced from PUFA peroxidation during production process, but it is unclear whether these oxidized lipids negatively affect growth performance and metabolic oxidation status in pigs. The objective of this study was to compare t...

  2. SULFUR POLYMER ENCAPSULATION.

    SciTech Connect

    KALB, P.

    2001-08-22

    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.

  3. Phylogenetic analysis of a highly specific association between ectosymbiotic, sulfur-oxidizing bacteria and a marine nematode.

    PubMed

    Polz, M F; Distel, D L; Zarda, B; Amann, R; Felbeck, H; Ott, J A; Cavanaugh, C M

    1994-12-01

    The phylogenetic relationship of chemoautotrophic, sulfur-oxidizing, ectosymbiotic bacteria growing on a marine nematode, a Laxus sp. (formerly a Catanema sp.), to known endosymbionts and free-living bacteria was determined. Comparative 16S rRNA sequencing was used to investigate the unculturable nematode epibionts, and rRNA-targeted oligonucleotide hybridization probes were used to identify the ectosymbionts in situ. Both analyses revealed a remarkably specific and stable symbiosis. Unique hybridization of a specific probe to the ectosymbionts indicated that only one species of bacteria was present and growing on the cuticle of the nematode. Distance and parsimony methods used to infer phylogenetic trees both placed the nematode ectosymbionts at the base of a branch containing chemoautotrophic, sulfur-oxidizing endosymbionts of three bivalve families and of the tube worm Riftia pachyptila. The most closely related free-living bacteria were chemoautotrophic sulfur oxidizers belonging to the genus Thiomicrospira. Furthermore, our results suggested that a second, only distantly related group of thioautotrophic endosymbionts has as its deepest branch surface-colonizing bacteria belonging to the genus Thiothrix, some of which are capable of sulfur-oxidizing chemoautotrophic growth. PMID:7529016

  4. Chemical bonding in the outer core: high-pressure electronic structures of oxygen and sulfur in metallic iron

    USGS Publications Warehouse

    Sherman, David M.

    1991-01-01

    The electronic structures of oxygen and sulfur impurities in metallic iron are investigated to determine if pressure, temperature, and composition-induced changes in bonding might affect phase equilibria along the Fe-FeS and Fe-FeO binaries. -from Authors

  5. Mineral Trioxide Aggregate and Portland Cement for Direct Pulp Capping in Dog: A Histopathological Evaluation

    PubMed Central

    Bidar, Maryam; Naghavi, Neda; Mohtasham, Nooshin; Sheik-Nezami, Mahshid; Fallahrastegar, Amir; Afkhami, Farzaneh; Attaran Mashhadi, Negin; Nargesi, Iman

    2014-01-01

    Background and aims. Mineral trioxide aggregate and calcium hydroxide are considered the gold standard pulp-capping materials. Recently, Portland cement has been introduced with properties similar to those of mineral trioxide aggregate. Histopathological effects of direct pulp capping using mineral trioxide aggregate and Portland cements on dog dental pulp tissue were evaluated in the present study. Materials and methods. This histopatological study was carried out on 64 dog premolars. First, the pulp was exposed with a sterile bur. Then, the exposed pulp was capped with white or gray mineral trioxide aggregates and white or gray Portland cements in each quadrant and sealed with glass-ionomer. The specimens were evaluated under a light microscope after 6 months. Statistical analysis was carried out using Kruskal-Wallis test. Statistical significance was defined at α=5%. Results. There was no acute inflammation in any of the specimens. Chronic inflammation in white and gray mineral trioxide aggregates and white and gray Portland cements was reported to be 45.5%, 27.3%, 57.1% and 34.1%, respectively. Although the differences were not statistically significant, severe inflammation was observed mostly adjacent to white mineral trioxide aggregate. The largest extent of increased vascularization (45%) and the least increase in fibrous tissue were observed adjacent to white mineral trioxide aggregate, with no significant differences. In addition, the least calcified tissue formed adjacent to white mineral trioxide aggregate, although the difference was not significant. Conclusion. The materials used in this study were equally effective as pulp protection materials following direct pulp capping in dog teeth. PMID:25346831

  6. Electrochromic properties of molybdenum trioxide thin films prepared by chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Maruyama, Toshiro; Kanagawa, Tetsuya

    1995-05-01

    Electrochromic molybdenum trioxide thin films were prepared by chemical vapor deposition. The source material was molybdenum carbonyl. Amorphous molybdenum trioxide thin films were produced at a substrate temperature 300 C. Reduction and oxidation of the films in a 0.3M LiClO4 propylene carbon ate solution caused desirable changes in optical absorption. Coulometry indicated that the coloration efficiency was 25.8 sq cm center-dot C(exp -1).

  7. Sulfuric acid-sulfur heat storage cycle

    DOEpatents

    Norman, John H.

    1983-12-20

    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.

  8. Sulfuric acid and hydrogen peroxide surface passivation effects on AlGaN/GaN high electron mobility transistors

    SciTech Connect

    Zaidi, Z. H. Lee, K. B.; Qian, H.; Jiang, S.; Houston, P. A.; Guiney, I.; Wallis, D. J.; Humphreys, C. J.

    2014-12-28

    In this work, we have compared SiN{sub x} passivation, hydrogen peroxide, and sulfuric acid treatment on AlGaN/GaN HEMTs surface after full device fabrication on Si substrate. Both the chemical treatments resulted in the suppression of device pinch-off gate leakage current below 1 μA/mm, which is much lower than that for SiN{sub x} passivation. The greatest suppression over the range of devices is observed with the sulfuric acid treatment. The device on/off current ratio is improved (from 10{sup 4}–10{sup 5} to 10{sup 7}) and a reduction in the device sub-threshold (S.S.) slope (from ∼215 to 90 mV/decade) is achieved. The sulfuric acid is believed to work by oxidizing the surface which has a strong passivating effect on the gate leakage current. The interface trap charge density (D{sub it}) is reduced (from 4.86 to 0.90 × 10{sup 12 }cm{sup −2} eV{sup −1}), calculated from the change in the device S.S. The gate surface leakage current mechanism is explained by combined Mott hopping conduction and Poole Frenkel models for both untreated and sulfuric acid treated devices. Combining the sulfuric acid treatment underneath the gate with the SiN{sub x} passivation after full device fabrication results in the reduction of D{sub it} and improves the surface related current collapse.

  9. Synthesis of Bi{sub 2}S{sub 3} with different sulfur content by conventional high temperature solid state solvothermal route

    SciTech Connect

    Solanki, S. I. Patel, I. B.; Shah, N. M.

    2014-04-24

    Bismuth sulfide (Bi{sub 2}S{sub 3}) is a binary chalcogenide compound material belonging to V-VI group of semiconductors. Because of its direct band gap of 1.3 eV and high figure of merit (ZT) value, it is widely used as a thermo electronic-cooling material based on the Peltier effect. The electrical and optical property of Bi{sub 2}S{sub 3} material is strongly dependent on stoichiometric composition, defect chemistry and structure. In this study, we have synthesized Bi{sub 2}S{sub x} (x = 3.15, 3.30, 3.45) compound material with different sulfur content by conventional high temperature solid state solvothermal reaction of bismuth and sulfur. X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDXS) analysis of synthesized compound materials were carried out to observe crystallinity, surface morphology and composition of elements in the compound. The optical analysis revealed that energy band gap decreases with increase of sulfur content.

  10. Mineral trioxide aggregate (MTA)-like materials: an update review.

    PubMed

    Mohammadi, Zahed; Shalavi, Sousan; Soltani, Mohammad Karim

    2014-09-01

    Mineral trioxide aggregate (MTA) is a multi-application material used in endodontics. It is a mixture of a refined Portland cement and bismuth oxide and trace amounts of SiO₂, CaO, MgO, K₂SO₄, and Na₂SO₄. MTA powder is mixed with supplied sterile water in a 3:1 powder/liquid. Hydrated MTA has an initial pH of 10.2, which rises to 12.5 three hours after mixing. There are several materials derived from MTA such as Endo-CPM Sealer, Ortho MTA, MTA-Fillapex, DiaRoot BioAggregate, MTA Bio, light-cured MTA, tricalcium silicate, and iRoot SP. The purpose of this article is to review MTA-like materials. PMID:25199028

  11. Clinical Applications of Mineral Trioxide Aggregate: Report of Four Cases

    PubMed Central

    Battepati, Prashant M

    2010-01-01

    The greatest threats to developing teeth are dental caries and traumatic injuries. The primary goal of all restorative treatment is to maintain pulp vitality so that normal root development or apexogenesis can occur. If pulpal exposure occurs, then a pulpotomy procedure aims to preserve pulp vitality to allow for normal root development. Historically, calcium hydroxide has been the material of choice for pulpotomy procedures. Recently, an alternative material called mineral trioxide aggregate (MTA) has demonstrated the ability to induce hard-tissue formation in pulpal tissue. This article describes the clinical and radiographic outcome of a series of cases involving the use of MTA in pulpotomy, apexogenesis and apexification procedures and root perforations repair.

  12. Chemical characteristics of mineral trioxide aggregate and its hydration reaction

    PubMed Central

    2012-01-01

    Mineral trioxide aggregate (MTA) was developed in early 1990s and has been successfully used for root perforation repair, root end filling, and one-visit apexification. MTA is composed mainly of tricalcium silicate and dicalcium silicate. When MTA is hydrated, calcium silicate hydrate (CSH) and calcium hydroxide is formed. Formed calcium hydroxide interacts with the phosphate ion in body fluid and form amorphous calcium phosphate (ACP) which finally transforms into calcium deficient hydroxyapatite (CDHA). These mineral precipitate were reported to form the MTA-dentin interfacial layer which enhances the sealing ability of MTA. Clinically, the use of zinc oxide euginol (ZOE) based materials may retard the setting of MTA. Also, the use of acids or contact with excessive blood should be avoided before complete set of MTA, because these conditions could adversely affect the hydration reaction of MTA. Further studies on the chemical nature of MTA hydration reaction are needed. PMID:23429542

  13. Mineral trioxide aggregate (MTA)-like materials: an update review.

    PubMed

    Mohammadi, Zahed; Shalavi, Sousan; Soltani, Mohammad Karim

    2014-09-01

    Mineral trioxide aggregate (MTA) is a multi-application material used in endodontics. It is a mixture of a refined Portland cement and bismuth oxide and trace amounts of SiO₂, CaO, MgO, K₂SO₄, and Na₂SO₄. MTA powder is mixed with supplied sterile water in a 3:1 powder/liquid. Hydrated MTA has an initial pH of 10.2, which rises to 12.5 three hours after mixing. There are several materials derived from MTA such as Endo-CPM Sealer, Ortho MTA, MTA-Fillapex, DiaRoot BioAggregate, MTA Bio, light-cured MTA, tricalcium silicate, and iRoot SP. The purpose of this article is to review MTA-like materials.

  14. Survival after a massive overdose of arsenic trioxide.

    PubMed

    Kim, Lawrence H C; Abel, Simon J C

    2009-03-01

    Arsenic poisoning remains a therapeutic challenge, and outcomes are often poor. An 18-year-old man deliberately ingested termiticide containing a massive dose of arsenic trioxide. Arsenic concentration was 6.3 micromol/L in serum on ICU Day 1, and 253 micromol/L in the first 24-hour urine sample, with a urinary arsenic/creatinine ratio of 84 200 micromol/mol. He was treated with the chelating agent meso-2,3-dimercaptosuccinic acid (DMSA) (replaced by dimercaprol on Days 2-5) and required intensive support for multisystem organ failure, but recovered slowly. Nine weeks after the ingestion the only ongoing clinical issue was persistent but slowly improving peripheral neuropathy.

  15. Chemical characteristics of mineral trioxide aggregate and its hydration reaction.

    PubMed

    Chang, Seok-Woo

    2012-11-01

    Mineral trioxide aggregate (MTA) was developed in early 1990s and has been successfully used for root perforation repair, root end filling, and one-visit apexification. MTA is composed mainly of tricalcium silicate and dicalcium silicate. When MTA is hydrated, calcium silicate hydrate (CSH) and calcium hydroxide is formed. Formed calcium hydroxide interacts with the phosphate ion in body fluid and form amorphous calcium phosphate (ACP) which finally transforms into calcium deficient hydroxyapatite (CDHA). These mineral precipitate were reported to form the MTA-dentin interfacial layer which enhances the sealing ability of MTA. Clinically, the use of zinc oxide euginol (ZOE) based materials may retard the setting of MTA. Also, the use of acids or contact with excessive blood should be avoided before complete set of MTA, because these conditions could adversely affect the hydration reaction of MTA. Further studies on the chemical nature of MTA hydration reaction are needed. PMID:23429542

  16. Cytochromes and iron sulfur proteins in sulfur metabolism of phototrophic bacteria

    NASA Technical Reports Server (NTRS)

    Fischer, U.

    1985-01-01

    Dissimilatory sulfur metabolism in phototrophic sulfur bacteria provides the bacteria with electrons for photosynthetic electron transport chain and, with energy. Assimilatory sulfate reduction is necessary for the biosynthesis of sulfur-containing cell components. Sulfide, thiosulfate, and elemental sulfur are the sulfur compounds most commonly used by phototrophic bacteria as electron donors for anoxygenic photosynthesis. Cytochromes or other electron transfer proteins, like high-potential-iron-sulfur protein (HIPIP) function as electron acceptors or donors for most enzymatic steps during the oxidation pathways of sulfide or thiosulfate. Yet, heme- or siroheme-containing proteins themselves undergo enzymatic activities in sulfur metabolism. Sirohemes comprise a porphyrin-like prosthetic group of sulfate reductase. eenzymatic reactions involve electron transfer. Electron donors or acceptors are necessary for each reaction. Cytochromes and iron sulfur problems, are able to transfer electrons.

  17. Investigation of chemical modifiers for sulfur determination in diesel fuel samples by high-resolution continuum source graphite furnace molecular absorption spectrometry using direct analysis

    NASA Astrophysics Data System (ADS)

    Huber, Charles S.; Vale, Maria Goreti R.; Welz, Bernhard; Andrade, Jailson B.; Dessuy, Morgana B.

    2015-06-01

    High-resolution continuum source graphite furnace molecular absorption spectrometry has been applied for sulfur determination in diesel fuel. The sharp rotational lines of the carbon monosulfide molecule (formed during the vaporization step) were used to measure the absorbance. The analytical line at 258.056 nm was monitored using the sum of three pixels. Different chemical modifiers were investigated and the mixture of palladium and magnesium was used as chemical modifier in combination with iridium as permanent modifier. L-Cysteine was chosen as sulfur standard and the calibration was done against aqueous standard solutions. The proposed method was applied for the analyses of four diesel samples: two S10 samples and two S500 samples. The trueness of the method was checked with a certified reference material (CRM) of sulfur in diesel fuel (NIST 2724b). Accurate results, for samples and CRM, were achieved after a dilution with propan-1-ol. The following figures of merit were obtained: characteristic mass of 17 ± 3 ng, limit of detection and limit of quantification of 1.4 mg kg- 1 and 4.7 mg kg- 1, respectively.

  18. High arsenic concentrations and enriched sulfur and oxygen isotopes in a fractured-bedrock ground-water system

    USGS Publications Warehouse

    Lipfert, G.; Sidle, W.C.; Reeve, A.S.; Ayuso, R.A.; Boyce, A.J.

    2007-01-01

    Ground water with high arsenic concentrations (up to 26.6????mol L- 1) has sulfate enriched in 34S and 18O in the fractured-bedrock, ground-water system of the Kelly's Cove watershed, Northport, Maine, USA. The ranges of sulfur and oxygen isotope values in aqueous sulfate, ??34S[SO4] and ??18O[SO4], at the Kelly's Cove watershed are + 3.4 to + 4.9??? and - 2.0 to + 6.7???, respectively. These isotope values are strikingly similar to those of the Goose River, Maine watershed which has ??34S[SO4] and ??18O[SO4] ranges of + 3.7 to + 4.6 ??? and - 2.6 to + 7.5???, respectively. In both systems, high arsenic concentrations occur with high ??34S[SO4] and ??18O[SO4] values, yet redox conditions and underlying rock types are quite different. The isotope values of sulfide minerals, ??34S[min], from four bedrock cores vary over short distances and range from - 5.1 to + 7.5???. The ??34S[SO4] values are controlled by the ??34S[min] values with minor input of atmospheric SO4. The much narrower range in ??34S[SO4] values than ??34S[min] values is probably due to sufficient ground-water mixing at a scale greater than the ??34S[min] variability. The ??34S[SO4] values are about 2??? higher than the average ??34S[min] value and fall within the range of ??34S[min] values, indicating only minor fractionation due to bacterial reduction of SO4. The highest ??18O[SO4] values were measured in the downgradient, confined, arsenic-rich ground water. High ??18O[SO4] values there cannot be due to aeration by atmospheric oxygen, but may arise from reoxidation of reduced SO4 products. The enrichment factors of ??18O in SO4 compared to H2O, + 7.2 to + 15.5???, in the Kelly's Cove ground water and the negligible 34S enrichment is very similar to those derived from experimental data of anaerobic sulfide oxidation in the presence of Mn and Fe oxides. Sea level at the Kelly's Cove watershed was approximately 80??m above present sea level about 13 000??years before present, imposing reducing

  19. Metagenome and Metatranscriptome Revealed a Highly Active and Intensive Sulfur Cycle in an Oil-Immersed Hydrothermal Chimney in Guaymas Basin.

    PubMed

    He, Ying; Feng, Xiaoyuan; Fang, Jing; Zhang, Yu; Xiao, Xiang

    2015-01-01

    The hydrothermal vent system is a typical chemosynthetic ecosystem in which microorganisms play essential roles in the geobiochemical cycling. Although it has been well-recognized that the inorganic sulfur compounds are abundant and actively converted through chemosynthetic pathways, the sulfur budget in a hydrothermal vent is poorly characterized due to the complexity of microbial sulfur cycling resulting from the numerous parties involved in the processes. In this study, we performed an integrated metagenomic and metatranscriptomic analysis on a chimney sample from Guaymas Basin to achieve a comprehensive study of each sulfur metabolic pathway and its hosting microorganisms and constructed the microbial sulfur cycle that occurs in the site. Our results clearly illustrated the stratified sulfur oxidation and sulfate reduction at the chimney wall. Besides, sulfur metabolizing is closely interacting with carbon cycles, especially the hydrocarbon degradation process in Guaymas Basin. This work supports that the internal sulfur cycling is intensive and the net sulfur budget is low in the hydrothermal ecosystem.

  20. Quantitative evaluation of Radix Paeoniae Alba sulfur-fumigated with different durations and purchased from herbal markets: simultaneous determination of twelve components belonging to three chemical types by improved high performance liquid chromatography-diode array detector.

    PubMed

    Kong, Ming; Liu, Huan-Huan; Xu, Jun; Wang, Chun-Ru; Lu, Ming; Wang, Xiao-Ning; Li, You-Bin; Li, Song-Lin

    2014-09-01

    In this study, a improved high performance liquid chromatography-diode array detector (HPLC-DAD) method for simultaneous quantification of twelve major components belonging to three chemical types was developed and validated, and was applied to quantitatively compare the quality of Radix Paeoniae Alba (RPA) sulfur-fumigated with different durations and purchased from commercial herbal markets. The contents of paeoniflorin, benzoylpaeoniflorin, oxypaeoniflorin, benzoic acid and paeonol decreased whereas that of paeoniflorin sulfonate increased in RPA with the extending of sulfur-fumigation duration. Different levels of paeoniflorin sulfonate were determined in ten of seventeen commercial RPA samples, indicating that these ten samples may be sulfur-fumigated with different durations. Moreover, the relative standard deviation of the contents of each component was higher in the commercial sulfur-fumigated RPA samples than that in commercial non-fumigated RPA samples, and the percentage of the total average content of monoterpene glycosides in the determined analytes was higher in the decoctions of commercial sulfur-fumigated RPA than that in commercial non-fumigated RPA samples. All these results suggested that the established method was precise, accurate and sensitive enough for the global quality evaluation of sulfur-fumigated RPA, and sulfur-fumigation can not only change the proportions of bioactive components, but also cause the reduction of the quality consistency of both raw materials and aqueous decoctions of RPA.

  1. Cytotoxicity patterns of arsenic trioxide exposure on HaCaT keratinocytes

    PubMed Central

    Udensi, Udensi K; Graham-Evans, Barbara E; Rogers, Christian; Isokpehi, Raphael D

    2011-01-01

    Background Arsenic is a ubiquitous environmental toxicant, and abnormalities of the skin are the most common outcomes of long-term, low-dose, chronic arsenic exposure. If the balance between keratinocyte proliferation, differentiation, and death is perturbed, pathologic changes of the epidermis may result, including psoriasis, atopic dermatitis, and certain forms of ichthyosis. Therefore, research investigations using in vitro human epidermal cells could help elucidate cellular and molecular processes in keratinocytes affected by arsenic. Data from such investigations could also provide the basis for developing cosmetic intervention for skin diseases caused by arsenic. Methods The viability of HaCaT keratinocyte cultures with or without prior exposure to low-dose arsenic trioxide was compared for varying concentrations of arsenic trioxide over a time course of 14 days because in untreated control cultures, approximately 2 weeks is required to complete cell differentiation. Long-term cultures were established by culturing HaCaT cells on collagen IV, and cells were subsequently exposed to 0 parts per million (ppm), 1 ppm, 5 ppm, 7.5 ppm, 10 ppm, and 15 ppm of arsenic trioxide. The percentages of viable cells as well as DNA damage after exposure were determined on Day 2, Day 5, Day 8, and Day 14. Results Using both statistical and visual analytics approaches for data analysis, we have observed a biphasic response at a 5 ppm dose with cell viability peaking on Day 8 in both chronic and acute exposures. Further, a low dose of 1 ppm arsenic trioxide enhanced HaCaT keratinocyte proliferation, whereas doses above 7.5 ppm inhibited growth. Conclusion The time course profiling of arsenic trioxide cytotoxicity using long-term HaCaT keratinocyte cultures presents an approach to modeling the human epidermal cellular responses to varying doses of arsenic trioxide treatment or exposure. A low dose of arsenic trioxide appears to aid cell growth but concomitantly disrupts the DNA

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

    NASA Astrophysics Data System (ADS)

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

    2013-11-01

    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%.

  3. PVP-Assisted Synthesis of Uniform Carbon Coated Li2S/CB for High-Performance Lithium-Sulfur Batteries.

    PubMed

    Chen, Lin; Liu, Yuzi; Zhang, Fan; Liu, Caihong; Shaw, Leon L

    2015-11-25

    The lithium-sulfur (Li-S) battery is a great alternative to the state-of-the-art lithium ion batteries due to its high energy density. However, low utilization of active materials, the insulating nature of sulfur or lithium sulfide (Li2S), and polysulfide dissolution in organic liquid electrolyte lead to low initial capacity and fast performance degradation. Herein, we propose a facile and viable approach to address these issues. This new approach entails synthesis of Li2S/carbon black (Li2S/CB) cores encapsulated by a nitrogen-doped carbon shell with polyvinylpyrrolidone (PVP) assistance. Combining energy-filtered transmission electron microscopy (EFTEM) elemental mappings, XPS and FTIR measurements, it is confirmed that the as-synthesized material has a structure of a Li2S/CB core with a nitrogen-doped carbon shell (denoted as Li2S/CB@NC). The Li2S/CB@NC cathode yields an exceptionally high initial capacity of 1020 mAh/g based on Li2S mass at 0.1 C with stable Coulombic efficiency of 99.7% over 200 cycles. Also, cycling performance shows the capacity decay per cycle as small as 0.17%. Most importantly, to further understand the materials for battery applications, field emission transmission electron microscopy (FETEM) and elemental mapping tests without exposure to air for Li2S samples in cycled cells are reported. Along with the first ever FETEM and field emission scanning electron microscopy (FESEM) investigations of cycled batteries, Li2S/CB@NC cathode demonstrates the capability of robust core-shell nanostructures for different rates and improved capacity retention, revealing Li2S/CB@NC designed here as an outstanding system for high-performance lithium-sulfur batteries. PMID:26529481

  4. PVP-Assisted Synthesis of Uniform Carbon Coated Li2S/CB for High-Performance Lithium-Sulfur Batteries.

    PubMed

    Chen, Lin; Liu, Yuzi; Zhang, Fan; Liu, Caihong; Shaw, Leon L

    2015-11-25

    The lithium-sulfur (Li-S) battery is a great alternative to the state-of-the-art lithium ion batteries due to its high energy density. However, low utilization of active materials, the insulating nature of sulfur or lithium sulfide (Li2S), and polysulfide dissolution in organic liquid electrolyte lead to low initial capacity and fast performance degradation. Herein, we propose a facile and viable approach to address these issues. This new approach entails synthesis of Li2S/carbon black (Li2S/CB) cores encapsulated by a nitrogen-doped carbon shell with polyvinylpyrrolidone (PVP) assistance. Combining energy-filtered transmission electron microscopy (EFTEM) elemental mappings, XPS and FTIR measurements, it is confirmed that the as-synthesized material has a structure of a Li2S/CB core with a nitrogen-doped carbon shell (denoted as Li2S/CB@NC). The Li2S/CB@NC cathode yields an exceptionally high initial capacity of 1020 mAh/g based on Li2S mass at 0.1 C with stable Coulombic efficiency of 99.7% over 200 cycles. Also, cycling performance shows the capacity decay per cycle as small as 0.17%. Most importantly, to further understand the materials for battery applications, field emission transmission electron microscopy (FETEM) and elemental mapping tests without exposure to air for Li2S samples in cycled cells are reported. Along with the first ever FETEM and field emission scanning electron microscopy (FESEM) investigations of cycled batteries, Li2S/CB@NC cathode demonstrates the capability of robust core-shell nanostructures for different rates and improved capacity retention, revealing Li2S/CB@NC designed here as an outstanding system for high-performance lithium-sulfur batteries.

  5. Sulfur minimization in bacterial leaching

    SciTech Connect

    Seth, R.; Prasad, D.; Henry, J.G.

    1996-11-01

    The production of sewage biosolids in Ontario in 1989 was estimated to be 7 million m{sup 3} of wet sludge per year. Of this amount, land application accounts for between 20 and 30% of the total. Unfortunately, the use of sewage biosolids on agricultural land is often prohibited because of heavy metal contamination of the biosolids. High cost and operational problems have made chemical methods of metal extraction unattractive. Consequently, microbiological methods of leaching of heavy metals have been studied for over a decade. A relatively simple microbiological process has been investigated in recent years in flask level experiments and recently in a semicontinuous system. The process exploits nonacidophilic and acidophilic indigenous thiobacilli to extract heavy metals from sewage biosolids. These thiobacilli use elemental sulfur as the energy source, producing sulfuric acid. However, the resulting decontaminated biosolids can cause environmental problems like acidification of the soil, when acid is generated from the residual sulfur in the biosolids. The present study examines the possibility of reducing the amount of sulfur added in batch and semicontinuous bacterial leaching systems, and maximizing sulfur oxidation efficiency, thereby reducing the residual sulfur in leached biosolids.

  6. Manganese and Ceria Sorbents for High Temperature Sulfur Removal from Biomass-Derived Syngas -- The Impact of Steam on Capacity and Sorption Mode

    SciTech Connect

    Cheah, S.; Parent, Y. O.; Jablonski, W. S.; Vinzant, T.; Olstad, J. L.

    2012-07-01

    Syngas derived from biomass and coal gasification for fuel synthesis or electricity generation contains sulfur species that are detrimental to downstream catalysts or turbine operation. Sulfur removal in high temperature, high steam conditions has been known to be challenging, but experimental reports on methods to tackle the problem are not often reported. We have developed sorbents that can remove hydrogen sulfide from syngas at high temperature (700 C), both in dry and high steam conditions. The syngas composition chosen for our experiments is derived from statistical analysis of the gasification products of wood under a large variety of conditions. The two sorbents, Cu-ceria and manganese-based, were tested in a variety of conditions. In syngas containing steam, the capacity of the sorbents is much lower, and the impact of the sorbent in lowering H{sub 2}S levels is only evident in low space velocities. Spectroscopic characterization and thermodynamic consideration of the experimental results suggest that in syngas containing 45% steam, the removal of H{sub 2}S is primarily via surface chemisorptions. For the Cu-ceria sorbent, analysis of the amount of H{sub 2}S retained by the sorbent in dry syngas suggests both copper and ceria play a role in H{sub 2}S removal. For the manganese-based sorbent, in dry conditions, there is a solid state transformation of the sorbent, primarily into the sulfide form.

  7. Demonstration of selective catalytic reduction (SCR) technology for the control of nitrogen oxide (NOx) emissions from high-sulfur coal-fired boilers

    SciTech Connect

    Not Available

    1991-11-01

    The objective of this project is to demonstrate and evaluate commercially available Selective Catalytic Reduction (SCR) catalysts from US, Japanese and European catalyst suppliers on a high-sulfur US coal-fired boiler. SCR is a post-combustion nitrogen oxide (NO{sub x}) control technology that involves injecting ammonia into the flue gas generated from coal combustion in an electric utility boiler. The flue gas containing ammonia is then passed through a reactor that contains a specialized catalyst. In the presence of the catalyst, the ammonia reacts with NO{sub x} to convert it to nitrogen and water vapor.

  8. High-precision sulfur isotope composition of enstatite meteorites and implications of the formation and evolution of their parent bodies

    NASA Astrophysics Data System (ADS)

    Defouilloy, C.; Cartigny, P.; Assayag, N.; Moynier, F.; Barrat, J.-A.

    2016-01-01

    In order to better understand the formation and evolution of their parent bodies, the three isotope ratios of sulfur were analyzed in 33 enstatite meteorites (24 enstatite chondrites and 9 aubrites). The results show that on average all enstatite chondrite groups are enriched in the lightest isotopes compared to other chondrite groups, with means of δ34S of -0.28 ± 0.22‰ for EH3/4, -0.16 ± 0.16‰ for EH5, -0.32 ± 0.15‰ for EL3, -0.67 ± 0.16‰ for EL6 and -0.64 ± 0.00‰ for EL7 (all 1σ). Aubrites show a larger isotope variability in their composition, with a δ34S varying from -1.350‰ to +0.154‰. Contrary to previously published results, our data show a distinct composition for EL6 compared to other enstatite chondrites. This could be related to an impact-induced loss of isotopically heavy oldhamite (δ34S = by 3.62 ± 3.02‰ (1σ)) on the EL parent body. Although the bulk sulfur in both enstatite meteorites and aubrites does not show any significant Δ33S and Δ36S, the oldhamite fraction shows clear evidence of mass independent fractionation on the 36S/32S ratio (in 3 out of 9 analyzes, Δ36S up to +2.2‰), a signal that is not correlated to any 33S/32S anomaly (in 1 out of 9 analyzes, Δ33S down to -0.085‰). Though a nebular or photochemical origin cannot be ruled out, the most plausible mechanism to produce such isolated non-mass dependent 36S/32S anomalies would be a contribution of FeCl2 containing excesses of 36S due to the decay of 36Cl to the leached oldhamite fraction. Even though the sulfur isotopic composition measured in enstatite meteorites is distinct from the Bulk Silicate Earth (BSE), the isotopically lightest samples of EL6, EL7 and aubrites are approaching the isotopic composition of the BSE and enstatite meteorites remain the meteorites with the sulfur isotopic composition the closest to the terrestrial one.

  9. Solubility of Sulfur Dioxide in Sulfuric Acid

    NASA Technical Reports Server (NTRS)

    Chang, K. K.; Compton, L. E.; Lawson, D. D.

    1982-01-01

    The solubility of sulfur dioxide in 50% (wt./wt.) sulfuric acid was evaluated by regular solution theory, and the results verified by experimental measurements in the temperature range of 25 C to 70 C at pressures of 60 to 200 PSIA. The percent (wt./wt.) of sulfur dioxide in 50% (wt./wt.) sulfuric acid is given by the equation %SO2 = 2.2350 + 0.0903P - 0.00026P 10 to the 2nd power with P in PSIA.

  10. Selective catalytic reduction of sulfur dioxide to elemental sulfur

    SciTech Connect

    Liu, Wei; Flytzani-Stephanopoulos, M.; Sarofim, A.F.

    1992-01-01

    Elemental sulfur recovery from SO[sub 2]-containing gas streams is highly attractive as it produces a saleable. Product and no waste to dispose of. However, commercially available schemes are complex and involve multi-stage reactors, such as, most notably in the Resox (reduction of SO[sub 2] with coke) and Claus plants(reaction of SO[sub 2] with H[sub 2]S over catalyst). This project win investigate a cerium oxide catalyst for the single-stage selective reduction SO[sub 2] to elemental sulfur by a reductant, such as carbon monoxide. Cerium oxide has been identified as a superior catalyst for SO[sub 2] reduction by CO to elemental sulfur because of its high activity and high selectivity to sulfur over COS over a wide temperature range(400--650C). Kinetic and parametric studies of SO[sub 2] reduction planned over various CeO[sub 2]-formulations will provide the necessary basis for development of a simplified process, a single-stage elemental sulfur recovery scheme from variable concentration gas streams. A first apparent application is treatment of regenerator off-gases in power plants using regenerative flue gas desulfurization. Such a simple catalytic converter may offer the long-sought Claus-alternative'' for coal-fired power plant applications.

  11. Sulfur oxide adsorbents and emissions control

    DOEpatents

    Li, Liyu; King, David L.

    2006-12-26

    High capacity sulfur oxide absorbents utilizing manganese-based octahedral molecular sieve (Mn--OMS) materials are disclosed. An emissions reduction system for a combustion exhaust includes a scrubber 24 containing these high capacity sulfur oxide absorbents located upstream from a NOX filter 26 or particulate trap.

  12. Charge-density analysis of an iron-sulfur protein at an ultra-high resolution of 0.48 Å.

    PubMed

    Hirano, Yu; Takeda, Kazuki; Miki, Kunio

    2016-06-01

    The fine structures of proteins, such as the positions of hydrogen atoms, distributions of valence electrons and orientations of bound waters, are critical factors for determining the dynamic and chemical properties of proteins. Such information cannot be obtained by conventional protein X-ray analyses at 3.0-1.5 Å resolution, in which amino acids are fitted into atomically unresolved electron-density maps and refinement calculations are performed under strong restraints. Therefore, we usually supplement the information on hydrogen atoms and valence electrons in proteins with pre-existing common knowledge obtained by chemistry in small molecules. However, even now, computational calculation of such information with quantum chemistry also tends to be difficult, especially for polynuclear metalloproteins. Here we report a charge-density analysis of the high-potential iron-sulfur protein from the thermophilic purple bacterium Thermochromatium tepidum using X-ray data at an ultra-high resolution of 0.48 Å. Residual electron densities in the conventional refinement are assigned as valence electrons in the multipolar refinement. Iron 3d and sulfur 3p electron densities of the Fe4S4 cluster are visualized around the atoms. Such information provides the most detailed view of the valence electrons of the metal complex in the protein. The asymmetry of the iron-sulfur cluster and the protein environment suggests the structural basis of charge storing on electron transfer. Our charge-density analysis reveals many fine features around the metal complex for the first time, and will enable further theoretical and experimental studies of metalloproteins. PMID:27279229

  13. Charge-density analysis of an iron-sulfur protein at an ultra-high resolution of 0.48 Å.

    PubMed

    Hirano, Yu; Takeda, Kazuki; Miki, Kunio

    2016-05-18

    The fine structures of proteins, such as the positions of hydrogen atoms, distributions of valence electrons and orientations of bound waters, are critical factors for determining the dynamic and chemical properties of proteins. Such information cannot be obtained by conventional protein X-ray analyses at 3.0-1.5 Å resolution, in which amino acids are fitted into atomically unresolved electron-density maps and refinement calculations are performed under strong restraints. Therefore, we usually supplement the information on hydrogen atoms and valence electrons in proteins with pre-existing common knowledge obtained by chemistry in small molecules. However, even now, computational calculation of such information with quantum chemistry also tends to be difficult, especially for polynuclear metalloproteins. Here we report a charge-density analysis of the high-potential iron-sulfur protein from the thermophilic purple bacterium Thermochromatium tepidum using X-ray data at an ultra-high resolution of 0.48 Å. Residual electron densities in the conventional refinement are assigned as valence electrons in the multipolar refinement. Iron 3d and sulfur 3p electron densities of the Fe4S4 cluster are visualized around the atoms. Such information provides the most detailed view of the valence electrons of the metal complex in the protein. The asymmetry of the iron-sulfur cluster and the protein environment suggests the structural basis of charge storing on electron transfer. Our charge-density analysis reveals many fine features around the metal complex for the first time, and will enable further theoretical and experimental studies of metalloproteins.

  14. Severe Acute Axonal Neuropathy following Treatment with Arsenic Trioxide for Acute Promyelocytic Leukemia: a Case Report

    PubMed Central

    Kühn, Marcus; Sammartin, Kety; Nabergoj, Mitja; Vianello, Fabrizio

    2016-01-01

    Peripheral neuropathy is a common complication of arsenic toxicity. Symptoms are usually mild and reversible following discontinuation of treatment. A more severe chronic sensorimotor polyneuropathy characterized by distal axonal-loss neuropathy can be seen in chronic arsenic exposure. The clinical course of arsenic neurotoxicity in patients with coexistence of thiamine deficiency is only anecdotally known but this association may potentially lead to severe consequences. We describe a case of acute irreversible axonal neuropathy in a patient with hidden thiamine deficiency who was treated with a short course of arsenic trioxide for acute promyelocytic leukemia. Thiamine replacement therapy and arsenic trioxide discontinuation were not followed by neurological recovery and severe polyneuropathy persisted at 12-month follow-up. Thiamine plasma levels should be measured in patients who are candidate to arsenic trioxide therapy. Prophylactic administration of vitamin B1 may be advisable. The appearance of polyneuropathy signs early during the administration of arsenic trioxide should prompt electrodiagnostic testing to rule out a pattern of axonal neuropathy which would need immediate discontinuation of arsenic trioxide. PMID:27158436

  15. Calcium looping process for high purity hydrogen production integrated with capture of carbon dioxide, sulfur and halides

    DOEpatents

    Ramkumar, Shwetha; Fan, Liang-Shih

    2013-07-30

    A process for producing hydrogen comprising the steps of: (i) gasifying a fuel into a raw synthesis gas comprising CO, hydrogen, steam, sulfur and halide contaminants in the form of H.sub.2S, COS, and HX, wherein X is a halide; (ii) passing the raw synthesis gas through a water gas shift reactor (WGSR) into which CaO and steam are injected, the CaO reacting with the shifted gas to remove CO.sub.2, sulfur and halides in a solid-phase calcium-containing product comprising CaCO.sub.3, CaS and CaX.sub.2; (iii) separating the solid-phase calcium-containing product from an enriched gaseous hydrogen product; and (iv) regenerating the CaO by calcining the solid-phase calcium-containing product at a condition selected from the group consisting of: in the presence of steam, in the presence of CO.sub.2, in the presence of synthesis gas, in the presence of H.sub.2 and O.sub.2, under partial vacuum, and combinations thereof.

  16. Calcium looping process for high purity hydrogen production integrated with capture of carbon dioxide, sulfur and halides

    DOEpatents

    Ramkumar, Shwetha; Fan, Liang-Shih

    2015-11-04

    A process for producing hydrogen comprising the steps of: (i) gasifying a fuel into a raw synthesis gas comprising CO, hydrogen, steam, sulfur and halide contaminants in the form of H.sub.2S, COS, and HX, wherein X is a halide; (ii) passing the raw synthesis gas through a water gas shift reactor (WGSR) into which CaO and steam are injected, the CaO reacting with the shifted gas to remove CO.sub.2, sulfur and halides in a solid-phase calcium-containing product comprising CaCO.sub.3, CaS and CaX.sub.2; (iii) separating the solid-phase calcium-containing product from an enriched gaseous hydrogen product; and (iv) regenerating the CaO by calcining the solid-phase calcium-containing product at a condition selected from the group consisting of: in the presence of steam, in the presence of CO.sub.2, in the presence of synthesis gas, in the presence of H.sub.2 and O.sub.2, under partial vacuum, and combinations thereof.

  17. Potassium Bromate Assay by Redox Titrimetry Using Arsenic Trioxide.

    PubMed

    Smeller, Johanna M; Leigh, Stefan D

    2003-01-01

    Bromate, a disinfectant, is one of the analytes of interest in wastewater analysis. Environmental laboratories have a regulatory need for their measurements to be traceable to NIST standards. Bromate is not currently certified as a NIST Standard Reference Material (SRM). Therefore, a traceable assay of potassium bromate (KBrO3) is needed. KBrO3 was dissolved in water and assayed by redox titrimetry using arsenic trioxide (As2O3). A nominal (0.1 g) sample of As2O3 was dissolved in 10 mL of 5 mol/L sodium hydroxide. The solution was acidified with hydrochloric acid and about 95 % of the KBrO3 titrant was added gravimetrically. The end point was determined by addition of dilute (1:3) titrant using an automated titrator. The KBrO3 assay was determined to be 99.76 % ± 0.20 %. The expanded uncertainty considered the titrations of three independently prepared KBrO3 solutions.

  18. Compressive Strength of Mineral Trioxide Aggregate with Propylene Glycol

    PubMed Central

    Ghasemi, Negin; Rahimi, Saeed; Shahi, Shahriar; Salem Milani, Amin; Rezaei, Yashar; Nobakht, Mahnaz

    2016-01-01

    Introduction: The aim of this study was to evaluate the effect of adding propylene glycol (PG) to mineral trioxide aggregate (MTA) liquid with volume ratio of 20% on the compressive strength (CS) of MTA in two time periods (4 and 21 days) after mixing. Methods and Materials: Four groups of steel cylinders (n=15) with an internal diameter of 3 and a height of 6 mm were prepared and MTA (groups 1 and 2) and MTA+PG (80% MTA liquid+20% PG) (groups 3 and 4) were placed in to the cylinders. In groups 1 and 3 the CS was evaluated after 4 days and in groups 2 and 4 after 21 days. Data were calculated using the two-ways ANOVA. The level of significance was set at 0.05. Results: The highest (52.22±18.92 MPa) and lowest (4.5±0.67 MPa) of CS was obtained in 21-day MTA samples and 4-day MTA+PG specimen, respectively. The effect of time and PG were significant on the CS (P<0.05). Mixing MTA with PG significantly reduced the CS; but passing the time from 4 to 21 days significantly increased the CS. Conclusion: Considering the limitations of this study, PG had a negative effect on CS of MTA. PMID:27790264

  19. Uranium trioxide behavior during electron energy loss spectroscopy analysis

    NASA Astrophysics Data System (ADS)

    Degueldre, Claude; Alekseev, Evgeny V.

    2015-03-01

    A sample of uranium trioxide (UO3) was produced by focused ion beam (~10 μm×~10 μm×<0.5 μm) for transmission electron and electron energy loss (EEL) spectroscopy examinations in a transmission electron microscope (TEM). The EEL spectra were recorded as a function of the thickness for the P and O edges in the low energy range 0-350 eV and were compared to spectra of UO3 small grains attached to a TEM grid. The EEL spectrum was studied through a range of thicknesses going from ~60 to ~260 nm. The EEL spectra recorded for UO3 are compared with those recorded for UO2. The reduction of UO3 into U4O9 and/or UO2 is readily observed apparently during the TEM investigations and as confirmed by electron diffraction (eD). This redox effect is similar to that known for other redox sensitive oxides. Recommendations are suggested to avoid sample decomposition.

  20. Kinetics and mechanism of photopromoted oxidative dissolution of antimony trioxide.

    PubMed

    Hu, Xingyun; Kong, Linghao; He, Mengchang

    2014-12-16

    Light (sunlight, ultraviolet, simulated sunlight) irradiation was used to initiate the dissolution of antimony trioxide (Sb2O3). Dissolution rate of Sb2O3 was accelerated and dissolved trivalent antimony (Sb(III)) was oxidized in the irradiation of light. The photopromoted oxidative dissolution mechanism of Sb2O3 was studied through experiments investigating the effects of pH, free radicals scavengers, dissolved oxygen removal and Sb2O3 dosage on the release rate of antimony from Sb2O3 under simulated sunlight irradiation. The key oxidative components were hydroxyl free radicals, photogenerated holes and superoxide free radicals; their contribution ratios were roughly estimated. In addition, a conceptual model of the photocatalytic oxidation dissolution of Sb2O3 was proposed. The overall pH-dependent dissolution rate of Sb2O3 and the oxidation of Sb(III) under light irradiation were expressed by r = 0.08 ·[OH(-)](0.63) and rox = 0.10 ·[OH(-)](0.79). The present study on the mechanism of the photo-oxidation dissolution of Sb2O3 could help clarify the geochemical cycle and fate of Sb in the environment.

  1. Lunar Sulfur Capture System

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

    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

  2. Are the clouds of Venus sulfuric acid.

    NASA Technical Reports Server (NTRS)

    Young, A. T.

    1973-01-01

    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.

  3. Observation of new particle formation and measurement of sulfuric acid, ammonia, amines and highly oxidized organic molecules at a rural site in central Germany

    NASA Astrophysics Data System (ADS)

    Kürten, Andreas; Bergen, Anton; Heinritzi, Martin; Leiminger, Markus; Lorenz, Verena; Piel, Felix; Simon, Mario; Sitals, Robert; Wagner, Andrea C.; Curtius, Joachim

    2016-10-01

    The exact mechanisms for new particle formation (NPF) under different boundary layer conditions are not known yet. One important question is whether amines and sulfuric acid lead to efficient NPF in the atmosphere. Furthermore, it is not clear to what extent highly oxidized organic molecules (HOMs) are involved in NPF. We conducted field measurements at a rural site in central Germany in the proximity of three larger dairy farms to investigate whether there is a connection between NPF and the presence of amines and/or ammonia due to the local emissions from the farms. Comprehensive measurements using a nitrate chemical ionization-atmospheric pressure interface time-of-flight (CI-APi-TOF) mass spectrometer, a proton-transfer-reaction mass spectrometer (PTR-MS), particle counters and differential mobility analyzers (DMAs), as well as measurements of trace gases and meteorological parameters, were performed. We demonstrate here that the nitrate CI-APi-TOF is suitable for sensitive measurements of sulfuric acid, amines, a nitrosamine, ammonia, iodic acid and HOMs. NPF was found to correlate with sulfuric acid, while an anti-correlation with RH, amines and ammonia is observed. The anti-correlation between NPF and amines could be due to the efficient uptake of these compounds by nucleating clusters and small particles. Much higher HOM dimer (C19/C20 compounds) concentrations during the night than during the day indicate that these HOMs do not efficiently self-nucleate as no nighttime NPF is observed. Observed iodic acid probably originates from an iodine-containing reservoir substance, but the iodine signals are very likely too low to have a significant effect on NPF.

  4. Sulfur and oxygen isotope study of the Vermont copper belt: evidence of seawater hydrothermal alteration and sulfate reduction in a high-grade metamorphic terrane

    SciTech Connect

    Shanks, W.C. III; Woodruff, L.G.; Slack, J.F.

    1985-01-01

    Massive sulfide deposits of the Orange County copper district, in east-central Vermont, consist of stratiform lenses of pyrrhotite, chalcopyrite, and minor sphalerite within amphibolite-facies rocks of Early Devonian (.) age. The deposits occur at several different stratigraphic levels. The two largest, Elizabeth and Ely, are in quartz-mica schists of the Gile Mountain Formation; the Pike Hill deposit occurs in calcareous quartz-mica schist of the underlying Waits River Formation. Two small deposits (Orange and Gove) are within the Standing Pond Volcanics, a thin tholeiitic amphibolite near the Gile Mountain-Waits River contact. The Elizabeth deposit in particularly distinctive, and contains a suite of unusual wall rocks rich in quartz, carbonate, muscovite, amphibole, phlogopite, tourmaline, spessartine, and sodic plagioclase. Sulfur isotope values at Elizabeth and Ely of 5.1 to 9.1 per thousands contrast with values for Gove (1.9 to 4.2) and Pike Hill (1.5 to 4.6). Disseminated sulfides in amphibolites of the Standing Pond Volcanics have sulfur isotope values in the range -0.1 to 1.7 per thousands, typical of MORB. These data require sulfur contributions to massive sulfide deposits both from basalt and from contemporaneous seawater sulfate sources. Whole-rock (carbonate free) oxygen isotope analyses of host lithologies range from 7.9 per thousands (Standing Pond Volcanics) to 19.9 per thousands (Waits River Formation). Detailed sampling of Elizabeth wall rocks (including those high in B, Na, Mg, Al, Si, Mn) yields a narrow range of oxygen isotope values (11.1 to 14.1); heavier values correlate with higher silica contents. Isotopically light wallrock lithologies are probably due to premetamorphic seawater hydrothermal alteration.

  5. High-molecular weight sulfur-containing aromatics refractory to weathering as determined by Fourier transform ion cyclotron resonance mass spectrometry.

    PubMed

    Hegazi, Abdelrahman H; Fathalla, Eiman M; Panda, Saroj K; Schrader, Wolfgang; Andersson, Jan T

    2012-09-01

    Biomarkers and low-molecular weight polyaromatic compounds have been extensively studied for their fate in the environment. They are used for oil spill source identification and monitoring of weathering and degradation processes. However, in some cases, the absence or presence of very low concentration of such components restricts the access of information to spill source. Here we followed the resistance of high-molecular weight sulfur-containing aromatics to the simulated weathering condition of North Sea crude oil by ultra high-resolution Fourier transform ion cyclotron resonance mass spectrometry. The sulfur aromatics in North Sea crude having double bond equivalents (DBE) from 6 to 14 with a mass range 188-674Da were less influenced even after 6 months artificial weathering. Moreover, the ratio of dibenzothiophenes (DBE 9)/naphthenodibenzothiophenes (DBE 10) was 1.30 and 1.36 in crude oil and 6 months weathered sample, respectively reflecting its weathering stability. It also showed some differences within other oils. Hence, this ratio can be used as a marker of the studied crude and accordingly may be applied for spilled oil source identification in such instances where the light components have already been lost due to environmental influences.

  6. Determination of sulfur in crude oil using high-resolution continuum source molecular absorption spectrometry of the SnS molecule in a graphite furnace.

    PubMed

    Cadorim, Heloisa R; Pereira, Éderson R; Carasek, Eduardo; Welz, Bernhard; de Andrade, Jailson B

    2016-01-01

    An analytical method for the determination of sulfur, as the tin mono-sulfide (SnS) molecule, in crude oil using high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS GF MAS) has been developed. The molecular absorbance of the SnS has been measured using the wavelength at 271.624 nm and the crude oil samples were prepared as micro-emulsions due to their high viscosity. Several chemical modifiers (Ir, Pd, Ru, Zr) were tested and palladium was chosen, because it exhibited the best performance. The heating program was optimized by comparing the pyrolysis and vaporization curves obtained for an aqueous sulfur standard and a micro-emulsion of a crude oil certified reference material (CRM). The optimum pyrolysis and vaporization temperatures were found to be 600 and 2000°C, respectively. The limit of detection and the characteristic mass using micro-emulsion analysis of crude oil samples were 5.8 and 13.3 ng S. Accuracy and precision of the method has been evaluated using two crude oil CRM (NIST 2721 and NIST 2722), showing good agreement with the informed or certified values.

  7. Mineral trioxide aggregate pulpotomy in autotransplanted immature mandibular third molar with a 4-year follow-up

    PubMed Central

    Dharmani, Umesh; Jadhav, Ganesh Ranganath; Kaur Dharmani, Charan Kamal; Devi, Takhellambam Premlata

    2016-01-01

    Autotransplantation is the surgical transposition of a tooth from its original site to another, replacing a lost or a compromised tooth by another tooth, usually the third molar in the same individual. This technique is considered a viable method due to its high success rate, well-grounded treatment option, provided the case selection and the procedure followed is within the acceptable limits. Autotransplantation is considered as an alternative approach of oral rehabilitations in a conservative manner mainly in young patients with compromised financial conditions to perform a high cost treatment. It is a fast way to recover function and aesthetic properties without interfering with the orofacial growth. This report describes a successful 4-year follow-up of a case of immediately performed mineral trioxide aggregate (MTA) pulpotomy in autotransplantated mandibular left immature third molar to replace the mandibular left first molar that was extracted due to extensive carious lesion. PMID:27217648

  8. Mineral trioxide aggregate pulpotomy in autotransplanted immature mandibular third molar with a 4-year follow-up.

    PubMed

    Dharmani, Umesh; Jadhav, Ganesh Ranganath; Kaur Dharmani, Charan Kamal; Devi, Takhellambam Premlata

    2016-01-01

    Autotransplantation is the surgical transposition of a tooth from its original site to another, replacing a lost or a compromised tooth by another tooth, usually the third molar in the same individual. This technique is considered a viable method due to its high success rate, well-grounded treatment option, provided the case selection and the procedure followed is within the acceptable limits. Autotransplantation is considered as an alternative approach of oral rehabilitations in a conservative manner mainly in young patients with compromised financial conditions to perform a high cost treatment. It is a fast way to recover function and aesthetic properties without interfering with the orofacial growth. This report describes a successful 4-year follow-up of a case of immediately performed mineral trioxide aggregate (MTA) pulpotomy in autotransplantated mandibular left immature third molar to replace the mandibular left first molar that was extracted due to extensive carious lesion.

  9. The Sulfur Cycle

    ERIC Educational Resources Information Center

    Kellogg, W. W.; And Others

    1972-01-01

    A model estimating the contributions of sulfur compounds by natural and human activities, and the rate of removal of sulfur from the atmosphere, is based on a review of the existing literature. Areas requiring additional research are identified. (AL)

  10. The embryotoxic response to maternal chromium trioxide exposure in different strains of hamsters

    SciTech Connect

    Gale, T.F.

    1982-10-01

    This paper compares the chromium trioxide-induced embryotoxic effects among one noninbred (LVG) and five inbred (CB, LHC, LSH, MHA, PD4) strains of hamsters. A single dose of chromium trioxide (8 mg/kg, iv) was injected into pregnant hamsters on the morning of gestation Day 8. Treated and control animals were killed on gestation Day 15 and studied for the types and incidence of external and internal abnormalities, as well as the frequency of resorption sites per uterus. The embryotoxic effects described in this study include significant rates of resorptions, external abnormalities, cleft palate, and hydrocephalus. The results indicate that the MHA, LSH, and LVG strains are susceptible, while the CB, LHC, and PD4 strains are resistant to chromium trioxide-induced embryotoxicity. This study was compared with prior work in which the same hamster strains were treated with either cadmium, lead, or mercury.

  11. Avulsed Immature Permanent Central Incisors Obturated With Mineral Trioxide Aggregate: A Case Report

    PubMed Central

    Al-Kahtani, Ahmed

    2013-01-01

    The endodontic management of immature permanent incisors in young children can be challenging. This case reported an avulsed immature maxillary central incisors that underwent complete endodontic obturation using mineral trioxide aggregate. A 10-year-old male who suffered a fall injury avulsed both his central incisors. The revascularization process was not possible due to patient compliance and geographic reasons. Mineral trioxide aggregate was utilized as a novel endodontic treatment. After one year post-injury, the teeth remained symptom-free, the clinical and radiographic follow-up showed evidence of healthy periodontium. How to cite this article: Al-Kahtani A. Avulsed Immature Permanent Central Incisors Obturated With Mineral Trioxide Aggregate: A Case Report. J Int Oral Health 2013; 5(3):88-96. PMID:24155609

  12. Targeting catalase but not peroxiredoxins enhances arsenic trioxide-induced apoptosis in K562 cells.

    PubMed

    Song, Li-Li; Tu, Yao-Yao; Xia, Li; Wang, Wei-Wei; Wei, Wei; Ma, Chun-Min; Wen, Dong-Hua; Lei, Hu; Xu, Han-Zhang; Wu, Ying-Li

    2014-01-01

    Despite considerable efficacy of arsenic trioxide (As2O3) in acute promyelocytic leukemia (APL) treatment, other non-APL leukemias, such as chronic myeloid leukemia (CML), are less sensitive to As2O3 treatment. However, the underlying mechanism is not well understood. Here we show that relative As2O3-resistant K562 cells have significantly lower ROS levels than As2O3-sensitive NB4 cells. We compared the expression of several antioxidant enzymes in these two cell lines and found that peroxiredoxin 1/2/6 and catalase are expressed at high levels in K562 cells. We further investigated the possible role of peroxirdoxin 1/2/6 and catalase in determining the cellular sensitivity to As2O3. Interestingly, knockdown of peroxiredoxin 1/2/6 did not increase the susceptibility of K562 cells to As2O3. On the contrary, knockdown of catalase markedly enhanced As2O3-induced apoptosis. In addition, we provide evidence that overexpression of BCR/ABL cannot increase the expression of PRDX 1/2/6 and catalase. The current study reveals that the functional role of antioxidant enzymes is cellular context and treatment agents dependent; targeting catalase may represent a novel strategy to improve the efficacy of As2O3 in CML treatment.

  13. Polymerization of aniline in the interlayer space of molybdenum trioxide and its electrochemical properties

    NASA Astrophysics Data System (ADS)

    Li, Yanping; Xiang, Yixian; Dong, Xiaowen; Xu, Jiaqiang; Ruan, Fei; Pan, Qingyi

    2009-08-01

    Molybdenum trioxide/polyaniline (MoO 3/PANI) composite was prepared first by ion-exchange reaction between aniline (ANI) and dodecylamine (DDA) which was intercalated precursor, and then was formed under the polymerization of ANI within the interlayer space of MoO 3 at 120 °C for 3 d in air. According to powder X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, infrared spectroscopy and electrochemical testing, MoO 3/PANI composite has layered structure, and its interlayer spacing is 1.127 nm. Moreover, it has high thermal stability with the compound and completes its weight loss at 751.9 °C. Electrochemical investigation shows that MoO 3 is the major active substance in the MoO 3/PANI electrode, and MoO 3/PANI electrode demonstrates better conductivity and electrochemical activity than pure MoO 3 electrode, attributed to the promotion of Li + and/or electron transport. In addition, the alternating current impedance proves that if the resistance of MoO 3/PANI electrode reduces apparently, the electrochemical activity will increase correspondingly, the same as the relationship between the ohmic resistance and the electrical conductivity.

  14. Electron Transfer Governed Crystal Transformation of Tungsten Trioxide upon Li Ions Intercalation.

    PubMed

    Wang, Zhiguo; He, Yang; Gu, Meng; Du, Yingge; Mao, Scott X; Wang, Chongmin

    2016-09-21

    Reversible insertion/extraction of foreign ions into/from a host lattice constitutes the fundamental operating principle of rechargeable battery and electrochromic materials. The insertion of foreign ions is a far more commonly observed structural evolution of the host lattice, and for the most cases such a lattice evolution is subtle. However, it has not been clear what factors control such a lattice structural evolution. Based on the tungsten trioxide (WO3) model crystal, we use in situ transmission electron microscopy (TEM) combined with density functional theory calculations to explore the nature of Li ions intercalation induced crystal symmetry evolution of WO3. We discovered that Li insertion into the octahedral cavity of the WO3 lattice will lead to a low to high symmetry transition, featuring a sequential monoclinic → tetragonal → cubic phase transition. The density functional theory results reveal that the phase transition is essentially governed by the electron transfer from Li to the WO6 octahedrons, which effectively leads to the weakening the W-O bond and modifies system band structure, resulting in an insulator-to-metal transition. The observation of the electronic effect on crystal symmetry and conductivity is significant, providing deep insights on the intercalation reactions in secondary rechargeable ion batteries and the approach for tailoring the functionalities of material based on insertion of ions in the lattice. PMID:27575951

  15. Bortezomib and Arsenic Trioxide Activity on a Myelodysplastic Cell Line (P39): A Gene Expression Study

    PubMed Central

    Savlı, Hakan; Galimberti, Sara; Sünnetçi, Deniz; Canestraro, Martina; Palumbo, Giuseppe; Nagy, Balint; Raimondo, Francesco Di; Petrini, Mario

    2015-01-01

    Objective: We aimed to understand the molecular pathways affected by bortezomib and arsenic trioxide treatment on myelomonocytoid cell line P39. Materials and Methods: Oligonucleotide microarray platforms were used for gene expression and pathway analysis. Confirmation studies were performed using quantitative real time PCR. Results: Bortezomib treatment has shown upregulated DIABLO and NF-κBIB (a NF-κB inhibitor) and downregulated NF-κB1, NF-κB2, and BIRC1 gene expressions. Combination treatment of the two compounds showed gene expression deregulations in concordance by the results of single bortezomib treatment. Especially, P53 was a pathway more significantly modified and a gene network centralized around the beta estradiol gene. Beta estradiol, BRCA2, and FOXA1 genes were remarkable deregulations in our findings. Conclusion: Results support the suggestions about possible use of proteasome inhibitors in the treatment of high-risk myelodysplastic syndrome (MDS). NF-κB was observed as an important modulator in leukemic transformation of MDS. PMID:25913414

  16. Targeting hedgehog signalling by arsenic trioxide reduces cell growth and induces apoptosis in rhabdomyosarcoma.

    PubMed

    Boehme, Karen A; Zaborski, Julian J; Riester, Rosa; Schweiss, Sabrina K; Hopp, Ulrike; Traub, Frank; Kluba, Torsten; Handgretinger, Rupert; Schleicher, Sabine B

    2016-02-01

    Rhabdomyosarcomas (RMS) are soft tissue tumours treated with a combination of surgery and chemotherapy. However, mortality rates remain high in case of recurrences and metastatic disease due to drug resistance and failure to undergo apoptosis. Therefore, innovative approaches targeting specific signalling pathways are urgently needed. We analysed the impact of different hedgehog (Hh) pathway inhibitors on growth and survival of six RMS cell lines using MTS assay, colony formation assay, 3D spheroid cultures, flow cytometry and western blotting. Especially the glioma-associated oncogene family (GLI) inhibitor arsenic trioxide (ATO) effectively reduced viability as well as clonal growth and induced cell death in RMS cell lines of embryonal, alveolar and sclerosing, spindle cell subtype, whereas normal skeletal muscle cells were hardly compromised by ATO. Combination of ATO with itraconazole potentiated the reduction of colony formation and spheroid size. These results show that ATO is a promising substance for treatment of relapsed and refractory RMS by directly targeting GLI transcription factors. The combination with itraconazole or other chemotherapeutic drugs has the opportunity to enforce the treatment efficiency of resistant and recurrent RMS.

  17. Interaction between arsenic trioxide and human primary cells: emphasis on human cells of myeloid origin.

    PubMed

    Binet, François; Antoine, Francis; Girard, Denis

    2009-03-01

    Arsenic trioxide (As(2)O(3); ATO) is considered to be one of the most potent drugs in cancer chemotherapy and is highly effective in the treatment of acute promyelocytic leukemia (APL). It is well established that treatment of APL patients with ATO is associated with the disappearance of the PML-RARalpha fusion transcript, the characteristic APL gene product of the chromosomal translocation t(15;17). Although its mode of action is still not fully understood, ATO is known to induce cell apoptosis via generation of reactive oxygen species and activation of caspases. Several reports have indicated that ATO acts principally by inducing cell apoptosis not only in APL, but in a variety of non-APL cells including myeloma cells, chronic myeloid leukemia cells and cells of immune origin, including B or T lymphocytes, macrophages and, more recently, neutrophils. There is an increasing amount of data, including some from our laboratory, concerning the interaction between ATO and human primary cells. The focus of this review will be to cover the role of ATO in human immune primary cells with special emphasis on cells of myeloid origin.

  18. Dye leakage and modification of fast-setting mineral trioxide aggregate.

    PubMed

    Challenger, Hereward; Lane, Jason; Becker, Ryan; Nassiripour, Sepehr; Torabinejad, Mahmoud

    2015-02-01

    The objective of this investigation was to determine and decrease dye leakage of fast-setting mineral trioxide aggregate (FSMTA). Specimens using differing setting times or concentrations of calcium sulfate modified FSMTA were assessed for dye penetration. Based on the results, no statistical difference was found in the dye leakage of FSMTA compared with regular mineral trioxide aggregate (MTA). The addition of 10 percent calcium sulfate resulted in a statistical reduction in dye leakage compared to both unmodified FSMTA and regular MTA. PMID:25868222

  19. A Carbon-Sulfur Hybrid with Pomegranate-like Structure for Lithium-Sulfur Batteries.

    PubMed

    Shi, Yanting; Lv, Wei; Niu, Shuzhang; He, Yanbing; Zhou, Guangmin; Chen, Guohua; Li, Baohua; Yang, Quan-Hong; Kang, Feiyu

    2016-05-01

    A carbon-sulfur hybrid with pomegranate-like core-shell structure, which demonstrates a high rate performance and relatively high cyclic stability, is obtained through carbonization of a carbon precursor in the presence of a sulfur precursor (FeS2 ) and a following oxidation of FeS2 to sulfur by HNO3 . Such a structure effectively protects the sulfur and leaves enough buffer space after Fe(3+) removal and, at the same time, has an interconnected conductive network. The capacity of the obtained hybrid is 450 mA h g(-1) under the current density of 5 C. This work provides a simple strategy to design and prepare various high-performance carbon-sulfur hybrids for lithium-sulfur batteries.

  20. High protists diversity in the plankton of sulfurous lakes and lagoons examined by 18s rRNA gene sequence analyses.

    PubMed

    Triadó-Margarit, Xavier; Casamayor, Emilio O

    2015-12-01

    Diversity of small protists was studied in sulfidic and anoxic (euxinic) stratified karstic lakes and coastal lagoons by 18S rRNA gene analyses. We hypothesized a major sulfide effect, reducing protist diversity and richness with only a few specialized populations adapted to deal with low-redox conditions and high-sulfide concentrations. However, genetic fingerprinting suggested similar ecological diversity in anoxic and sulfurous than in upper oxygen rich water compartments with specific populations inhabiting euxinic waters. Many of them agreed with genera previously identified by microscopic observations, but also new and unexpected groups were detected. Most of the sequences matched a rich assemblage of Ciliophora (i.e., Coleps, Prorodon, Plagiopyla, Strombidium, Metopus, Vorticella and Caenomorpha, among others) and algae (mainly Cryptomonadales). Unidentified Cercozoa, Fungi, Stramenopiles and Discoba were recurrently found. The lack of GenBank counterparts was higher in deep hypolimnetic waters and appeared differentially allocated in the different taxa, being higher within Discoba and lower in Cryptophyceae. A larger number of populations than expected were specifically detected in the deep sulfurous waters, with unknown ecological interactions and metabolic capabilities. PMID:26224512

  1. Preparative Separation of Sulfur-Containing Diketopiperazines from Marine Fungus Cladosporium sp. Using High-Speed Counter-Current Chromatography in Stepwise Elution Mode

    PubMed Central

    Gu, Binbin; Zhang, Yanying; Ding, Lijian; He, Shan; Wu, Bin; Dong, Junde; Zhu, Peng; Chen, Juanjuan; Zhang, Jinrong; Yan, Xiaojun

    2015-01-01

    High-speed counter-current chromatography (HSCCC) was successively applied to the separation of three sulfur-containing diketopiperazines (DKPs) (including two new compounds cladosporin A (1) and cladosporin B (3), and a known compound haematocin (2)) from a marine fungus Cladosporium sp. The two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water at (1:1:1:1, v/v) and (2:1:2:1, v/v), in stepwise elution mode, was used for HSCCC. The preparative HSCCC separation was performed on 300 mg of crude sample yielding 26.7 mg of compound 3 at a purity of over 95%, 53.6 mg of a mixture of compounds 1 and 2, which was further separated by preparative-HPLC yielding 14.3 mg of compound 1 and 25.4 mg of compound 2 each at a purity of over 95%. Their structures were established by spectroscopic methods. The sulfur-containing DKPs suppressed the proliferation of hepatocellular carcinoma cell line HepG2. The present work represents the first application of HSCCC in the efficient preparation of marine fungal natural products. PMID:25584683

  2. Preparative separation of sulfur-containing diketopiperazines from marine fungus Cladosporium sp. using high-speed counter-current chromatography in stepwise elution mode.

    PubMed

    Gu, Binbin; Zhang, Yanying; Ding, Lijian; He, Shan; Wu, Bin; Dong, Junde; Zhu, Peng; Chen, Juanjuan; Zhang, Jinrong; Yan, Xiaojun

    2015-01-09

    High-speed counter-current chromatography (HSCCC) was successively applied to the separation of three sulfur-containing diketopiperazines (DKPs) (including two new compounds cladosporin A (1) and cladosporin B (3), and a known compound haematocin (2)) from a marine fungus Cladosporium sp. The two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water at (1:1:1:1, v/v) and (2:1:2:1, v/v), in stepwise elution mode, was used for HSCCC. The preparative HSCCC separation was performed on 300 mg of crude sample yielding 26.7 mg of compound 3 at a purity of over 95%, 53.6 mg of a mixture of compounds 1 and 2, which was further separated by preparative-HPLC yielding 14.3 mg of compound 1 and 25.4 mg of compound 2 each at a purity of over 95%. Their structures were established by spectroscopic methods. The sulfur-containing DKPs suppressed the proliferation of hepatocellular carcinoma cell line HepG2. The present work represents the first application of HSCCC in the efficient preparation of marine fungal natural products.

  3. High protists diversity in the plankton of sulfurous lakes and lagoons examined by 18s rRNA gene sequence analyses.

    PubMed

    Triadó-Margarit, Xavier; Casamayor, Emilio O

    2015-12-01

    Diversity of small protists was studied in sulfidic and anoxic (euxinic) stratified karstic lakes and coastal lagoons by 18S rRNA gene analyses. We hypothesized a major sulfide effect, reducing protist diversity and richness with only a few specialized populations adapted to deal with low-redox conditions and high-sulfide concentrations. However, genetic fingerprinting suggested similar ecological diversity in anoxic and sulfurous than in upper oxygen rich water compartments with specific populations inhabiting euxinic waters. Many of them agreed with genera previously identified by microscopic observations, but also new and unexpected groups were detected. Most of the sequences matched a rich assemblage of Ciliophora (i.e., Coleps, Prorodon, Plagiopyla, Strombidium, Metopus, Vorticella and Caenomorpha, among others) and algae (mainly Cryptomonadales). Unidentified Cercozoa, Fungi, Stramenopiles and Discoba were recurrently found. The lack of GenBank counterparts was higher in deep hypolimnetic waters and appeared differentially allocated in the different taxa, being higher within Discoba and lower in Cryptophyceae. A larger number of populations than expected were specifically detected in the deep sulfurous waters, with unknown ecological interactions and metabolic capabilities.

  4. Aqueous synthesis of Cu-doped ZnCdS/ZnS core/shell nanocrystals with a new and highly reactive sulfur source.

    PubMed

    Zeng, Ruosheng; Shen, Rongan; Zhao, Yunqiang; Li, Xingsheng; Sun, Zhiguo; Shen, Yayun

    2014-04-01

    A new sulfur precursor with a highly reactive chemical nature was prepared with S powder and NaBH₄ at the high temperature of 180 °C in a closed autoclave and made it possible to carry out the synthesis of high quality metal sulfide nanocrystals (NCs) with diverse composition and structure. Using this new sulfur source, we demonstrated aqueous synthesis of colloidal Cu-doped ZnCdS NCs (d-dots) with pure, color-tunable photoluminescence (PL) in a wide spectral range (from 517 to 650 nm) based on the 'co-nucleation doping' strategy. The influences of the various experimental variables, including Cd/Zn ratio, Cu-doping concentration, pH value and amount of mercaptopropionic acid (MPA), on the optical properties of Cu-doped ZnCdS NCs were systematically investigated. Furthermore, highly efficient and stable dopant emission from Cu:ZnCdS/ZnS core/shell d-dots with PL quantum yield as high as 40% was achieved by the deposition of a ZnS shell around the bare Cu:ZnCdS cores; this is the highest reported to date for aqueous doped NCs. The optical properties and structure of the d-dots were characterized by UV-vis absorption spectra, PL spectra, x-ray photoelectron spectroscopy, powder x-ray diffraction, and transmission electron microscopy. The experimental results indicated that this facile synthesis route would provide a versatile approach for the preparation of other water-soluble sulfide NCs. PMID:24583650

  5. Aqueous synthesis of Cu-doped ZnCdS/ZnS core/shell nanocrystals with a new and highly reactive sulfur source

    NASA Astrophysics Data System (ADS)

    Zeng, Ruosheng; Shen, Rongan; Zhao, Yunqiang; Li, Xingsheng; Sun, Zhiguo; Shen, Yayun

    2014-04-01

    A new sulfur precursor with a highly reactive chemical nature was prepared with S powder and NaBH4 at the high temperature of 180 °C in a closed autoclave and made it possible to carry out the synthesis of high quality metal sulfide nanocrystals (NCs) with diverse composition and structure. Using this new sulfur source, we demonstrated aqueous synthesis of colloidal Cu-doped ZnCdS NCs (d-dots) with pure, color-tunable photoluminescence (PL) in a wide spectral range (from 517 to 650 nm) based on the ‘co-nucleation doping’ strategy. The influences of the various experimental variables, including Cd/Zn ratio, Cu-doping concentration, pH value and amount of mercaptopropionic acid (MPA), on the optical properties of Cu-doped ZnCdS NCs were systematically investigated. Furthermore, highly efficient and stable dopant emission from Cu:ZnCdS/ZnS core/shell d-dots with PL quantum yield as high as 40% was achieved by the deposition of a ZnS shell around the bare Cu:ZnCdS cores; this is the highest reported to date for aqueous doped NCs. The optical properties and structure of the d-dots were characterized by UV-vis absorption spectra, PL spectra, x-ray photoelectron spectroscopy, powder x-ray diffraction, and transmission electron microscopy. The experimental results indicated that this facile synthesis route would provide a versatile approach for the preparation of other water-soluble sulfide NCs.

  6. Sulfuric acid on Europa and the radiolytic sulfur cycle

    NASA Technical Reports Server (NTRS)

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

    1999-01-01

    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.

  7. Microscopic and spectroscopic analysis of tungsten trioxide and titanium-doped tungsten trioxide thin films

    NASA Astrophysics Data System (ADS)

    Yun, Young Taek

    Tungsten oxide (WO3) has been a subject of high interest for its unique properties, and recently for its importance in different types of industrial applications which ranges from non-emissive displays, optical, microelectronic, catalytic/photocatalytic, humidity, temperature, gas, and biosensor devices. In this study, WO3 and Ti doped thin films were prepared using radio frequency magnetron reactive sputtering at different substrate temperatures ranging from room temperature to 500 °C in increments of 100 °C. After forming a hypothesis based on knowledge of established WO3 properties, we attempt in this work to investigate how the doping influences the roughness and the mean grain size of the nanoparticles on the surface layer of the thin films, its structure, and crystallinity. Therefore we pursued analysis by Atomic Force Microscopy (AFM), X-ray diffraction (XRD), and Raman spectroscopy, using a comparative approach. The outcomes of these analyses demonstrate that higher temperatures are necessary for growing crystalline material if doping is used. Also, smaller nanoparticles are obtained when a small amount of dopant, e.g. 5% Ti, is incorporated. Both XRD and Raman measurement indicate morphological changes of the doped material. Finally, annealing of the amorphous doped samples at temperatures of 600 °C and 900 °C did not contribute significantly to material properties improvement.

  8. Sulfur tolerant anode materials

    SciTech Connect

    Not Available

    1988-05-01

    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.

  9. Biochemistry of sulfur

    SciTech Connect

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

    1986-01-01

    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.

  10. Sulfur tolerant anode materials

    SciTech Connect

    Not Available

    1988-02-01

    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.

  11. Sulfur tolerant anode materials

    SciTech Connect

    Not Available

    1987-02-01

    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.

  12. Thermal behaviour of arsenic trioxide adsorbed on activated carbon.

    PubMed

    Cuypers, Frederic; De Dobbelaere, Christopher; Hardy, An; Van Bael, Marlies K; Helsen, Lieve

    2009-07-30

    The thermal stability and desorption of arsenic trioxide (As(2)O(3)) adsorbed on activated carbon (AC) was investigated as this phenomenon is expected to influence the arsenic release during low temperature pyrolysis of chromated copper arsenate (CCA) wood waste. Firstly, a thermogravimetric (TG) experiment with arsenolite, an allotropic form of As(2)O(3), was performed. The sample starts to sublime at temperatures lower than 200 degrees C with a sublimation peak temperature of 271 degrees C. Subsequently, TG experiments with samples of As(2)O(3) adsorbed on AC revealed that only very little (max. 6+/-3 wt%) As(2)O(3) was volatilized at temperatures below 280 degrees C, while still 41.6 (+/-5)wt% of the original arsenic concentration was retained at 440 degrees C and 28.5 (+/-3)wt% at 600 degrees C. The major arsenic volatilization occurred between 300 degrees C and 500 degrees C. The kinetic parameters of desorption, activation energy of desorption (E(d)) and pre-exponential factor (A), were determined by fitting an Arrhenius model to the experimental data, resulting in E(d)=69 kJ/mol, A=1.21 x 10(4)s(-1). It can be concluded that the adsorption of As(2)O(3) on AC can contribute to the thermal stabilisation of As(2)O(3). Consequently, during low temperature pyrolysis of CCA wood arsenic release may be prevented by adsorption of As(2)O(3) on the coal-type product formed during the thermal decomposition of the wood. PMID:19136209

  13. Interaction between arsenic trioxide (ATO) and human neutrophils.

    PubMed

    Binet, François; Chiasson, Sonia; Girard, Denis

    2011-05-01

    The cytotoxic effect of arsenic trioxide (ATO) is known to be mediated by its ability to induce cell apoptosis in a variety of cells, including neutrophils. More recently, we demonstrated that ATO induced several parameters involved in endoplasmic reticulum (ER) stress-induced neutrophil apoptosis but that caspase-4 was not involved. The aim of this study was to better understand how neutrophils are activated by ATO and to further demonstrate that ATO is an ER stressor. Human neutrophils were isolated from healthy blood donors and incubated in vitro in the presence or absence of ATO and several parameters were investigated. We found that ATO induced the expression of the proapoptotic GADD153 protein, a key player involved in ER stress-induced apoptosis, activated nuclear nuclear factor κB (NF-κB) DNA binding activities, and increased prostaglandine E2 (PGE2) production. Using an antibody array approach, we found that ATO increased the production of several cytokines, with interleukin 8 (IL-8) being the predominant one. We confirmed that ATO increased the production of IL-8 by enzyme-linked-immunosorbent assay (ELISA). Treatment with a caspase-4 inhibitor did not inhibit IL-8 production. The results of the present study further support the notion that ATO is an ER stressor and that, although its toxic effect is mediated by induction of apoptosis, this chemical also induced, in parallel, NF-κB activation, the production of PGE2 and several cytokines probably involved in other cell functions. Also, we conclude that the production of IL-8 is not induced by a caspase-4-dependent mechanism, suggesting that ATO-induced caspase-4 activation is involved in other as yet unidentified functions in human neutrophils.

  14. Extraction, separation and analysis of high sulfur coal. Technical progress report No. 11, January 1, 1990--March 21, 1990

    SciTech Connect

    Olesik, S.V.

    1990-04-02

    In summary, significant bond cleavage was found only for thiophenol under the supercritical conditions studied. Less than 5% yield was found for the observed reaction products for all the other organosulfur compounds. The hydrogen sulfur bond in thiophenol is clearly the weakest of those studied and therefore it is the easiest to rupture. Also a general trend was observed the solvolysis reaction products such as ethylthiobenzene were the products initially formed at lower temperatures. But with higher temperatures the reaction product were those typically produced from the bimolecular association of free-radicals, such as phenylsulfide for the thiophenol sample. This type of reaction would be expected in pyrolysis reactions. Bimolecular reactions between organosulfur compounds would not be expected when the reaction is occurring at the surface of the solid coal matrix. The probability of the extracted organosulfur radicals having such bimolecular reactions is quite low. However, the reactions that are observed from the interaction of supercritical ethanol and the model coal compounds are not ones that show obvious indications of desulfurization of the compound.

  15. Co-firing high sulfur coal with refuse derived fuels. Progress report No. 3, [April--June 1995

    SciTech Connect

    Pan, Wei-Ping; Riley, J.T.; Lloyd, W.G.

    1995-05-31

    The Thermogravimetric Analyzer-Fourier Transform Infrared Spectrometer-Mass Spectrometer (TG-FTIR-MS) system was used to identify molecular chlorine, along with HCl, CO, CO{sub 2}, H{sub 2}O, and various hydrocarbons in the gaseous products of the combustion of PVC resin in air. This is a significant finding that will lead us to examine this combustion step further to look for the formation of chlorinated organic compounds. The combination of TG-FTIR and TG-MS offers complementary techniques for the detection and identification of combustion products from coals PVC, cellulose, shredded newspaper, and various blends of these materials. The pilot atmospheric fluidized bed combustor (AFBC) at Western Kentucky University has been tested. The main purpose of these preliminary AFBC runs were to determine the compatibility of coal and pelletized wood in blends and to explore the effects of flue/air ratio. Our objective is to conduct AFBC burns with 90 percent sulfur capture and more then 96% combustion efficiency.

  16. Contribution to the photometric determination of small amounts of boron trioxide in glasses

    NASA Technical Reports Server (NTRS)

    Markova, D.

    1985-01-01

    The photometric determination for boron trioxide is described in amounts of 0-75 micrograms B2O3 with an azomethin H reagent. The yellow colored complex which occurs in a medium held at a pH of 4.5 was measured in light of a wavelength of 415 nm.

  17. A note on the biological activity of the noble gas compound xenon trioxide.

    NASA Technical Reports Server (NTRS)

    Siegel, S. M.; Smith, C. W.

    1972-01-01

    Comparison of xenon trioxide for toxicity in the few common oxidants using three bioassays. On a molar basis XeO3 and HOCl were similar, but XeO3 was less active than expected when comparisons were based on normality.

  18. Effect of sulfur content in a sulfur-activated carbon composite on the electrochemical properties of a lithium/sulfur battery

    SciTech Connect

    Park, Jin-Woo; Kim, Changhyeon; Ryu, Ho-Suk; Cho, Gyu-Bong; Cho, Kwon-Koo; Kim, Ki-Won; Ahn, Jou-Hyeon; Wang, Guoxiu; Ahn, Jae-Pyeung; Ahn, Hyo-Jun

    2015-09-15

    Highlights: • The content of sulfur in activated carbon was controlled by solution process. • The sulfur electrode with low sulfur content shows the best performance. • The Li/S battery has capacity of 1360 mAh/g at 1 C and 702 mAh/g at 10 C. - Abstract: The content of sulfur in sulfur/activated carbon composite is controlled from 32.37 wt.% to 55.33 wt.% by a one-step solution-based process. When the sulfur content is limited to 41.21 wt.%, it can be loaded into the pores of an activated carbon matrix in a highly dispersed state. On the contrary, when the sulfur content is 55.33 wt.%, crystalline sulfur can be detected on the surface of the activated carbon matrix. The best electrochemical performance can be obtained for a sulfur electrode with the lowest sulfur content. The sulfur/activated carbon composite with 32.37 wt.% sulfur afforded the highest first discharge capacity of 1360 mAh g{sup −1} at 1 C rate and a large reversible capacity of 702 mAh g{sup −1} at 10 C (16.75 A/g)

  19. Comparison of lime and iron oxide for high temperature sulfur removal. Final technical report, September 1, 1989--December 31, 1991

    SciTech Connect

    Reid, K.J.; Hepworth, M.T.; Reindl, W.

    1994-05-01

    Slagging combustors with injected lime or limestone are being considered as replacements for conventional coal burners. They have advantages in that they can be staged to reduce NO{sub X} and SO{sub X} emissions. Lime and limestone are the currently preferred sorbent materials but iron oxide, as an alternative to lime or limestone may be effective not only as a desulfurization agent, but, under the right conditions of oxygen potential, it can act as a flux to produce a glassy slag. This glassy slag should be dense and environmentally inert. This project aimed to compare the sorption characteristic of lime and iron based sorbents in a novel double vortex combustor. The first phase of the project was the design installation and commissioning of the combustor test rig following which sorbent test work could be carried out. Due to a variety of unknown factors in the combustor design/performance characteristics, it was not possible to complete all aspects of the sorbent test work as originally planned. A considerable amount of experience has been gained in the operation of the combustor and in understanding the importance of key design factors. It was found that a narrow conical design for the combustor body gave significant improvement in combustion performance and in solids entrainment compared to a cylindrical form. Tests with a glass combustor were used extensively to obtain visual insights into flame flow patterns, structural stability and general operating characteristics. Due to time pressure and termination of the project no material balance was possible on the final sulfur run. Visual examination of the solids product did however, indicate that surface modification of the taconite particles had occurred and that an Fe-O-S phase had formed. The project has stimulated the interest of the local power utilities and it is planned to move the system to a local power plant for continuing test work.

  20. High-resolution (SIMS) versus bulk sulfur isotope patterns of pyrite in Proterozoic microbialites with diverse mat textures

    NASA Astrophysics Data System (ADS)

    Gomes, M. L.; Fike, D. A.; Bergmann, K.; Knoll, A. H.

    2015-12-01

    Sulfur (S) isotope signatures of sedimentary pyrite preserved in marine rocks provide a rich suite of information about changes in biogeochemical cycling associated with the evolution of microbial metabolisms and oxygenation of Earth surface environments. Conventionally, these S isotope records are based on bulk rock measurements. Yet, in modern microbial mat environments, S isotope compositions of sulfide can vary by up to 40‰ over a spatial range of ~ 1 mm. Similar ranges of S isotope variability have been found in Archean pyrite grains using both Secondary Ion Mass Spectrometry and other micro-analytical techniques. These micron-scale patterns have been linked to changes in rates of microbial sulfate reduction and/or sulfide oxidation, isotopic distillation of the sulfate reservoir due to microbial sulfate reduction, and post-depositional alteration. Fine-scale mapping of S isotope compositions of pyrite can thus be used to differentiate primary environmental signals from post-depositional overprinting - improving our understanding of both. Here, we examine micron-scale S isotope patterns of pyrite in microbialites from the Mesoproterozoic-Neoproterozoic Sukhaya Tunguska Formation and Neoproterozoic Draken Formation in order to explore S isotope variability associated with different mat textures and pyrite grain morphologies. A primary goal is to link modern observations of how sulfide spatial isotope distributions reflect active microbial communities present at given depths in the mats to ancient processes driving fine-sale pyrite variability in microbialites. We find large (up to 60‰) S isotope variability within a spatial range of less than 2.5cm. The micron-scale S isotope measurements converge around the S isotope composition of pyrite extracted from bulk samples of the same microbialites. These micron-scale pyrite S isotope patterns have the potential to reveal important information about ancient biogeochemical cycling in Proterozoic mat environments

  1. Porous dimanganese trioxide microflowers derived from microcoordinations for flexible solid-state asymmetric supercapacitors

    NASA Astrophysics Data System (ADS)

    Pang, Huan; Li, Xinran; Li, Bing; Zhang, Yizhou; Zhao, Qunxing; Lai, Wen-Yong; Huang, Wei

    2016-06-01

    Dimanganese trioxide microflowers are easily obtained from a Mn(ii) 8-hydroxyquinoline microcoordination after calcination in air. We also look into the possible formation mechanism of the flower-like morphology, and find that the reaction time affects the morphology of the coordination. Furthermore, the as-prepared porous Mn2O3 microflowers are made of many nanoplates which form many nanogaps and nanochannels. Interestingly, the assembled electrode based on the as-prepared porous Mn2O3 microflowers proves to be a high-performance electrode material for supercapacitors. The electrode shows a specific capacitance of 994 F g-1, which can work well even after 4000 cycles at 0.75 A g-1. More importantly, the porous Mn2O3 microflowers and activated carbons are assembled into a high-performance flexible solid-state asymmetric supercapacitor with a specific capacitance of 312.5 mF cm-2. The cycle test shows that the device can offer 95.6% capacity of the initial capacitance at 2.0 mA cm-2 after 5000 cycles with little decay. The maximum energy density of the device can achieve 6.56 mWh cm-3 and the maximum power density can also achieve 283.5 mW cm-3, which are among the best results for manganese based materials.Dimanganese trioxide microflowers are easily obtained from a Mn(ii) 8-hydroxyquinoline microcoordination after calcination in air. We also look into the possible formation mechanism of the flower-like morphology, and find that the reaction time affects the morphology of the coordination. Furthermore, the as-prepared porous Mn2O3 microflowers are made of many nanoplates which form many nanogaps and nanochannels. Interestingly, the assembled electrode based on the as-prepared porous Mn2O3 microflowers proves to be a high-performance electrode material for supercapacitors. The electrode shows a specific capacitance of 994 F g-1, which can work well even after 4000 cycles at 0.75 A g-1. More importantly, the porous Mn2O3 microflowers and activated carbons are

  2. Sulfur Tolerant Pd/Cu and Pd/Au Alloy Membranes for H2 Separation with High Pressure CO2 for Sequestration

    SciTech Connect

    Yi Hua Ma; Natalie Pomerantz; Chao-Huang Chen

    2008-09-30

    The effect of H{sub 2}S poisoning on Pd, Pd/Cu, and Pd/Au alloy composite membranes prepared by the electroless deposition method on porous Inconel supports was investigated to provide a fundamental understanding of the durability and preparation of sulfur tolerant membranes. X-ray photoelectron spectroscopy (XPS) studies showed that the exposure of pure Pd to 50 ppm H{sub 2}S/H{sub 2} mixtures caused bulk sulfide formation at lower temperatures and surface sulfide formation at higher temperatures. Lower temperatures, longer exposure times, and higher H{sub 2}S concentrations resulted in a higher degree of sulfidation. In a Pd membrane, the bulk sulfide formation caused a drastic irrecoverable H{sub 2} permeance decline and an irreparable loss in selectivity. Pd/Cu and Pd/Au alloy membranes exhibited permeance declines due to surface sulfide formation upon exposure to 50 ppm H{sub 2}S/H{sub 2} gas mixtures. However in contrast to the pure Pd membrane, the permeances of the Pd/Cu and Pd/Au alloy membranes were mostly recovered in pure H{sub 2} and the selectivity of the Pd alloy layers remained essentially intact throughout the characterization in H{sub 2}, He and H{sub 2}S/H{sub 2} mixtures which lasted several thousand hours. The amount of irreversible sulfur poisoning decreased with increasing temperature due to the exothermicity of H{sub 2}S adsorption. Longer exposure times increased the amount of irreversible poisoning of the Pd/Cu membrane but not the Pd/Au membrane. Pd/Au coupon studies of the galvanic displacement method showed that higher Au{sup 3+} concentrations, lower pH values, higher bath temperatures and stirring the bath at a rate of 200 rpm yielded faster displacement rates, more uniform depositions, and a higher Au content within the layers. While 400 C was found to be sufficient to form a Pd/Au alloy on the surface, high temperature X-ray diffraction (HTXRD) studies showed that even after annealing between 500-600 C, the Pd/Cu alloys could have

  3. Seawater sulfur isotope fluctuations in the Cretaceous.

    PubMed

    Paytan, Adina; Kastner, Miriam; Campbell, Douglas; Thiemens, Mark H

    2004-06-11

    The exogenic sulfur cycle is tightly coupled with the carbon and oxygen cycles, and therefore a central component of Earth's biogeochemistry. Here we present a high-resolution record of the sulfur isotopic composition of seawater sulfate for the Cretaceous. The general enrichment of isotopically light sulfur that prevailed during the Cretaceous may have been due to increased volcanic and hydrothermal activity. Two excursions toward isotopically lighter sulfur represent periods of lower rates of pyrite burial, implying a shift in the location of organic carbon burial to terrestrial or open-ocean settings. The concurrent changes in seawater sulfur and inorganic carbon isotopic compositions imply short-term variability in atmospheric oxygen partial pressure.

  4. The Low-temperature Ion Sulfurizing Technology and its Applications

    NASA Astrophysics Data System (ADS)

    Ma, G. Z.; Xu, B. S.; Wang, H. D.; Li, G. L.; Zhang, S.

    A solid lubrication film mainly consists of FeS, which has excellent tribology properties, can be formed on the sulfurized iron or steel surface. The sulfurizing technology has aroused intense attention from the day it appeared. However, the widespread industrial application of sulfurizing technology was promoted by the low-temperature ion sulfurizing (LTIS) process. This paper summarized the phylogeny and sorts of sulfurizing technology firstly; then, the process flow of LTIS technology, the forming mechanism, microstructure and tribological properties of ion sulfurized layer were introduced detailedly; and then, the technological, economic and environmental merits of LTIS technology were generalized; finally, the industrial applications of LTIS technology in various typical rolling, sliding and heavy duty parts were reviewed briefly. LTIS technology, with the advantages of high sulfurizing speed, good performance of sulfurized layer and without sideeffect, has played an important role in the tribology modification of ferrous parts, and the LTIS process will become more green, simple and efficient in the future.

  5. The global sulfur cycle

    NASA Technical Reports Server (NTRS)

    Sagan, D. (Editor)

    1985-01-01

    The results of the planetary biology microbial ecology's 1984 Summer Research Program, which examined various aspects of the global sulfur cycle are summarized. Ways in which sulfur flows through the many living and chemical species that inhabit the surface of the Earth were investigated. Major topics studied include: (1) sulfur cycling and metabolism of phototropic and filamentous sulfur bacteria; (2) sulfur reduction in sediments of marine and evaporite environments; (3) recent cyanobacterial mats; (4) microanalysis of community metabolism in proximity to the photic zone in potential stromatolites; and (5) formation and activity of microbial biofilms on metal sulfides and other mineral surfaces. Relationships between the global sulfur cycle and the understanding of the early evolution of the Earth and biosphere and current processes that affect global habitability are stressed.

  6. Arsenic trioxide phosphorylates c-Fos to transactivate p21{sup WAF1/CIP1} expression

    SciTech Connect

    Liu Zimiao; Huang, H.-S.

    2008-12-01

    An infamous poison, arsenic also has been used as a drug for nearly 2400 years; in recently years, arsenic has been effective in the treatment of acute promyelocytic leukemia. Increasing evidence suggests that opposite effects of arsenic trioxide (ATO) on tumors depend on its concentrations. For this reason, the mechanisms of action of the drug should be elucidated, and it should be used therapeutically only with extreme caution. Previously, we demonstrated the opposing effects of ERK1/2 and JNK on p21{sup WAF1/CIP1} (p21) expression in response to ATO in A431 cells. In addition, JNK phosphorylates c-Jun (Ser{sup 63/73}) to recruit TGIF/HDAC1 to suppress p21 gene expression. Presently, we demonstrated that a high concentration of ATO sustains ERK1/2 phosphorylation, and increases c-Fos biosynthesis and stability, which enhances p21 gene expression. Using site-directed mutagenesis, a DNA affinity precipitation assay, and functional assays, we demonstrated that phosphorylation of the C-terminus of c-Fos (Thr{sup 232}, Thr{sup 325}, Thr{sup 331}, and Ser{sup 374}) plays an important role in its binding to the p21 promoter, and in conjunction with N-terminus phosphorylation of c-Fos (Ser{sup 70}) to transactivate p21 promoter expression. In conclusion, a high concentration of ATO can sustain ERK1/2 activation to enhance c-Fos expression, then dimerize with dephosphorylated c-Jun (Ser{sup 63/73}) and recruit p300/CBP to the Sp1 sites (- 84/- 64) to activate p21 gene expression in A431 cells.

  7. Fly ash sulfur concrete

    SciTech Connect

    Head, W.J.; Liao, M.

    1981-05-01

    Two waste products, flyash and elemental sulfur, can be combined with a modifying agent to produce a potentially useful construction material, flyash sulfur concrete. Manufacturing processes and characteristics of this concrete are described. Compared with a conventional crushed stone aggregate, flyash sulfur concrete is a viable highway pavement base course material. The material's strength characteristics are analyzed. (1 diagram, 4 graphs, 2 photos, 9 references, 5 tables)

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

    SciTech Connect

    Kandylis, K.; Bray, A.C.

    1987-01-01

    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.

  9. Solid-state C-13 and H-1 NMR imaging stdies of the accelerated-sulfur cured high vinyl polybutadiene. [NMR (nuclear magnetic resonance)

    SciTech Connect

    Rana, M.A.

    1993-01-01

    Solid-state [sup 13]C NMR and [sup 1]H Imaging methods have been used to follow the progress of accelerated-sulfur vulcanization of unfilled high vinyl polybutadiene. Different NMR pulse sequences have been used to characterize the micro-network structures present in the bulk of the finally cured rubber samples. These studies were made as a function of formulation and processing variables. The time-resolved, integrated rubber network. Mono-sulfidic as well as the residual accelerator fragments were differentiated from the polysulfidic crosslinks in a finally cured material. Dynamic studies of these network structures were made using spin-spin relaxation (T[sub 2c]) measurements. The activation energies calculated based on T[sub 2] were used to verify different carbons, directly attached to the sulfur atoms. A swelling method based on Flory-Rehner's equation was also used to determine the crosslink densities and the number-average molecular weight between the nodal junctions in different formulations. Different spatially resolved structural features have been detected in the swollen samples using NMR imaging method. The voids, no-voids and other impurities were differentiated on the basis of magnetic susceptibility differences. Cyclohexane was used as a swelling solvent to probe the morphological defects in these materials. The T[sub 2]-weighted images were used to evaluate the crosslink densities in different samples. The quantitative estimations based on histogram was also employed to determine the average volume per crosslink region. The contrast based on H-1 spin-density or mobility was highlighted in T[sub 2]-weighted images. The variations were found to be closely related to variation in both concentration and mobility of the network.

  10. High-field 1H T1 and T2 NMR relaxation time measurements of H2O in homeopathic preparations of quartz, sulfur, and copper sulfate

    NASA Astrophysics Data System (ADS)

    Baumgartner, Stephan; Wolf, Martin; Skrabal, Peter; Bangerter, Felix; Heusser, Peter; Thurneysen, André; Wolf, Ursula

    2009-09-01

    Quantitative meta-analyses of randomized clinical trials investigating the specific therapeutic efficacy of homeopathic remedies yielded statistically significant differences compared to placebo. Since the remedies used contained mostly only very low concentrations of pharmacologically active compounds, these effects cannot be accounted for within the framework of current pharmacology. Theories to explain clinical effects of homeopathic remedies are partially based upon changes in diluent structure. To investigate the latter, we measured for the first time high-field (600/500 MHz) 1H T1 and T2 nuclear magnetic resonance relaxation times of H2O in homeopathic preparations with concurrent contamination control by inductively coupled plasma mass spectrometry (ICP-MS). Homeopathic preparations of quartz (10 c-30 c, n = 21, corresponding to iterative dilutions of 100-10-100-30), sulfur (13 x-30 x, n = 18, 10-13-10-30), and copper sulfate (11 c-30 c, n = 20, 100-11-100-30) were compared to n = 10 independent controls each (analogously agitated dilution medium) in randomized and blinded experiments. In none of the samples, the concentration of any element analyzed by ICP-MS exceeded 10 ppb. In the first measurement series (600 MHz), there was a significant increase in T1 for all samples as a function of time, and there were no significant differences between homeopathic potencies and controls. In the second measurement series (500 MHz) 1 year after preparation, we observed statistically significant increased T1 relaxation times for homeopathic sulfur preparations compared to controls. Fifteen out of 18 correlations between sample triplicates were higher for controls than for homeopathic preparations. No conclusive explanation for these phenomena can be given at present. Possible hypotheses involve differential leaching from the measurement vessel walls or a change in water molecule dynamics, i.e., in rotational correlation time and/or diffusion. Homeopathic preparations

  11. A rapid microwave synthesis of nitrogen-sulfur co-doped carbon nanodots as highly sensitive and selective fluorescence probes for ascorbic acid.

    PubMed

    Duan, Junxia; Yu, Jie; Feng, Suling; Su, Li

    2016-06-01

    A ultrafast one-step microwave-assisted method was developed for the synthesis of nitrogen-sulfur co-doped carbon nanodots (N,S-CDs) by using ethylenediamine as the carbon source and sulfamic acid as the surface passivation reagent. The morphology and the properties of N,S-CDs were explored by a series of techniques, such as high-resolution transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, UV-vis absorption and fluorescence spectroscopy. The prepared N,S-CDs exhibit bright blue photoluminescence with a high fluorescence quantum yield (FLQY) up to 28%, and high stability and excellent water solubility. A N,S-CDs-based fluorescent probe was developed for sensitive detection ascorbic acid (AA) in the presence of Cu(2+), based on the mechanism that AA reduces Cu(2+) to Cu(+), then Cu(+) quenches the fluorescence of N,S-CDs through electron or energy transfer due to the interaction between Cu(+) and thiol ligand on the N,S-CDs surface. The observed linear response concentration range was from 0.057 to 4.0μM to AA with a detection limit as low as 18nM. The probe exhibited a highly selective response toward AA even in the presence of possible interfering substances, such as uric acid and citric acid. Moreover, these promising features made the sensing system used for the analysis of human serum and urine samples. PMID:27130124

  12. Twenty Years of Research on Mineral Trioxide Aggregate: A Scientometric Report

    PubMed Central

    Asgary, Saeed; Motazedian, Hamid Reza; Parirokh, Masoud; Eghbal, Mohammad Jafar; Kheirieh, Sanam

    2013-01-01

    Introduction Mineral trioxide aggregate (MTA) has been suggested for root-end filling, vital pulp therapy, apical plug, perforations repair, and root canal filling. Since the introduction of MTA in 1993, many studies about this material have been published. The aim of this survey was to illustrate statistical information about published articles in PubMed-index journals vis-à-vis the various aspects of this biomaterial. Material and Methods A PubMed search was performed to retrieve the relative articles from 1993 to August 2012. The data of each article including publication year, journal name, number of authors, first author name, affiliations and study design were recorded. Citation of each article till 2009 was obtained from Scopus and Google scholar databases. Data were analyzed to determine the related scientometric indicators. Results In total, 1027 articles were found in PubMed-indexed journals which show considerable increase from 2 papers in 1993 to 139 in 2011. While ~62% of articles had no level of evidence, only ~5% could be classified as having the highest level of evidence (LOE1); however, the majority of LOE1 articles originated from Iran (~1%: n=10). Journal of Endodontics, as the top rank journal, published 31.7% of MTA related articles. The majority of articles were four-authored (19.6%). Most of the articles originated from USA (21.9%), Brazil (18.5%) and Iran (8.76%). The average number of citation for the top ten articles from Scopus was 231. Conclusion This data demonstrates that during the past two decades, research on this novel endodontic biomaterial had a rapid positive trend especially during the last 5 years. Further high-level evidence articles for the various clinical applications of MTA would result in superior clinical decision making and stronger scientific-based endodontic practice. PMID:23411944

  13. Recovery of elemental sulfur from sour gas

    SciTech Connect

    Reed, R.L.

    1984-07-31

    Excess heat generated in a thermal reaction zone of a Claus sulfur recovery plant is used, by means of a high boiling point heat transfer medium, to reheat the Claus plant process stream prior to high temperature Claus catalytic conversion, and/or to regenerate Claus catalyst on which sulfur is deposited, or for other functions. In another aspect, low temperature Claus catalytic converters are operated at equivalent pressures during a cycle comprising an adsorption phase, a regeneration phase, and a cooling phase.

  14. Sulfur and sulfides in chondrules

    NASA Astrophysics Data System (ADS)

    Marrocchi, Yves; Libourel, Guy

    2013-10-01

    The nature and distribution of sulfides within type I PO, POP and PP chondrules of the carbonaceous chondrite Vigarano (CV3) have been studied by secondary electron microscopy and electron microprobe. They occur predominantly as spheroidal blebs composed entirely of low-Ni iron sulfide (troilite, FeS) or troilite + magnetite but in less abundance in association with metallic Fe-Ni beads in opaque assemblages. Troilites are mainly located within the low-Ca pyroxene outer zone and their amounts increase with the abundance of low-Ca pyroxene within chondrules, suggesting co-crystallization of troilite and low-Ca pyroxene during high-temperature events. We show that sulfur concentration and sulfide occurrence in chondrules obey high temperature sulfur solubility and saturation laws. Depending on the fS2 and fO2 of the surrounding gas and on the melt composition, mainly the FeO content, sulfur dissolved in chondrule melts may eventually reach a concentration limit, the sulfur content at sulfide saturation (SCSS), at which an immiscible iron sulfide liquid separates from the silicate melt. The occurrence of both a silicate melt and an immiscible iron sulfide liquid is further supported by the non-wetting behavior of sulfides on silicate phases in chondrules due to the high interfacial tension between their precursor iron-sulfide liquid droplets and the surrounding silicate melt during the high temperature chondrule-forming event. The evolution of chondrule melts from PO to PP towards more silicic compositions, very likely due to high PSiO(g) of the surrounding nebular gas, induces saturation of FeS at much lower S content in PP than in PO chondrules, leading to the co-crystallization of iron sulfides and low-Ca pyroxenes. Conditions of co-saturation of low-Ca pyroxene and FeS are only achieved in non canonical environments characterized by high partial pressures of sulfur and SiO and redox conditions more oxidizing than IW-3. Fe and S mass balance calculations also

  15. Advanced sulfur control concepts

    SciTech Connect

    Gangwal, S.K.; Turk, B.S.; Gupta, R.P.

    1995-11-01

    Regenerable metal oxide sorbents, such as zinc titanate, are being developed to efficiently remove hydrogen sulfide (H{sub 2}S) from coal gas in advanced power systems. Dilute air regeneration of the sorbents produces a tailgas containing a few percent sulfur dioxide (SO{sub 2}). Catalytic reduction of the SO{sub 2} to elemental sulfur with a coal gas slipstream using the Direct Sulfur Recovery Process (DSRP) is a leading first-generation technology. Currently the DSRP is undergoing field testing at gasifier sites. The objective of this study is to develop second-generation processes that produce elemental sulfur without coal gas or with limited use. Novel approaches that were evaluated to produce elemental sulfur from sulfided sorbents include (1) sulfur dioxide (SO{sub 2}) regeneration, (2) substoichiometric (partial) oxidation, (3) steam regeneration followed by H{sub 2}S oxidation, and (4) steam-air regeneration. Preliminary assessment of these approaches indicated that developing SO{sub 2} regeneration faced the fewest technical and economic problems among the four process options. Elemental sulfur is the only likely product of SO{sub 2} regeneration and the SO{sub 2} required for the regeneration can be obtained by burning a portion of the sulfur produced. Experimental efforts have thus been concentrated on SO{sub 2}-based regeneration processes. Results from laboratory investigations are presented and discussed.

  16. Sulfur isotopic data

    SciTech Connect

    Rye, R.O.

    1987-01-01

    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.

  17. The Phases of Sulfur.

    ERIC Educational Resources Information Center

    Birdwhistell, Kurt R.

    1995-01-01

    Presents a demonstration that illustrates the dramatic changes that sulfur undergoes upon heating to 200 degrees centigrade and then cooling to room temperature. Supplements the demonstration of the rubberlike properties of catenasulfur made by rapid cooling of the sulfur melt in ice water. (JRH)

  18. A High-Performing Sulfur-Tolerant and Redox-Stable Layered Perovskite Anode for Direct Hydrocarbon Solid Oxide Fuel Cells.

    PubMed

    Ding, Hanping; Tao, Zetian; Liu, Shun; Zhang, Jiujun

    2015-12-09

    Development of alternative ceramic oxide anode materials is a key step for direct hydrocarbon solid oxide fuel cells (SOFCs). Several lanthanide based layered perovskite-structured oxides demonstrate outstanding oxygen diffusion rate, favorable electronic conductivity, and good oxygen surface exchange kinetics, owing to A-site ordered structure in which lanthanide and alkali-earth ions occupy alternate (001) layers and oxygen vacancies are mainly located in [LnOx] planes. Here we report a nickel-free cation deficient layered perovskite, (PrBa)0.95(Fe0.9Mo0.1)2O5 + δ (PBFM), for SOFC anode, and this anode shows an outstanding performance with high resistance against both carbon build-up and sulfur poisoning in hydrocarbon fuels. At 800 °C, the layered PBFM showed high electrical conductivity of 59.2 S cm(-1) in 5% H2 and peak power densities of 1.72 and 0.54 W cm(-2) using H2 and CH4 as fuel, respectively. The cell exhibits a very stable performance under a constant current load of 1.0 A cm(-2). To our best knowledge, this is the highest performance of ceramic anodes operated in methane. In addition, the anode is structurally stable at various fuel and temperature conditions, suggesting that it is a feasible material candidate for high-performing SOFC anode.

  19. Hierarchical sulfur-impregnated hydrogenated TiO2 mesoporous spheres comprising anatase nanosheets with highly exposed (001) facets for advanced Li-S batteries

    NASA Astrophysics Data System (ADS)

    Yuan, Changzhou; Zhu, Siqi; Cao, Hui; Hou, Linrui; Lin, Jingdong

    2016-01-01

    In this contribution, we purposefully designed hierarchical hydrogenated TiO2 spheres (HTSs) constructed from ultrathin anatase nanosheets with highly exposed (001) facets, and further utilized them as an efficient encapsulated host of sulfur species for advanced Li-S batteries (LSBs). Strikingly, the as-fabricated hybrid S/HTSs cathode exhibited high Coulombic efficiency (>94%), exceptional long cycling performance (capacity decay of ˜0.399% per cycle at 0.5 C), and large reversible discharge capacity (˜579 mAh g-1 at 2.0 C) at high C rates, benefiting from better electronic conductivity, smaller charge transfer resistance and strong chemical bonding between {{{{S}}}n}2- and the reduced (001) facets of HTSs, according to experimental measurements and systematical theoretical calculations. More significantly, our in-depth insights into the mechanism involved in the hybrid S/HTSs could efficiently guide future design, optimization and synthesis of other metal oxide-based matrixes with specific exposed crystal facets for next-generation advanced LSBs.

  20. A High-Performing Sulfur-Tolerant and Redox-Stable Layered Perovskite Anode for Direct Hydrocarbon Solid Oxide Fuel Cells

    PubMed Central

    Ding, Hanping; Tao, Zetian; Liu, Shun; Zhang, Jiujun

    2015-01-01

    Development of alternative ceramic oxide anode materials is a key step for direct hydrocarbon solid oxide fuel cells (SOFCs). Several lanthanide based layered perovskite-structured oxides demonstrate outstanding oxygen diffusion rate, favorable electronic conductivity, and good oxygen surface exchange kinetics, owing to A-site ordered structure in which lanthanide and alkali-earth ions occupy alternate (001) layers and oxygen vacancies are mainly located in [LnOx] planes. Here we report a nickel-free cation deficient layered perovskite, (PrBa)0.95(Fe0.9Mo0.1)2O5 + δ (PBFM), for SOFC anode, and this anode shows an outstanding performance with high resistance against both carbon build-up and sulfur poisoning in hydrocarbon fuels. At 800 °C, the layered PBFM showed high electrical conductivity of 59.2 S cm−1 in 5% H2 and peak power densities of 1.72 and 0.54 W cm−2 using H2 and CH4 as fuel, respectively. The cell exhibits a very stable performance under a constant current load of 1.0 A cm−2. To our best knowledge, this is the highest performance of ceramic anodes operated in methane. In addition, the anode is structurally stable at various fuel and temperature conditions, suggesting that it is a feasible material candidate for high-performing SOFC anode. PMID:26648509

  1. A High-Performing Sulfur-Tolerant and Redox-Stable Layered Perovskite Anode for Direct Hydrocarbon Solid Oxide Fuel Cells.

    PubMed

    Ding, Hanping; Tao, Zetian; Liu, Shun; Zhang, Jiujun

    2015-01-01

    Development of alternative ceramic oxide anode materials is a key step for direct hydrocarbon solid oxide fuel cells (SOFCs). Several lanthanide based layered perovskite-structured oxides demonstrate outstanding oxygen diffusion rate, favorable electronic conductivity, and good oxygen surface exchange kinetics, owing to A-site ordered structure in which lanthanide and alkali-earth ions occupy alternate (001) layers and oxygen vacancies are mainly located in [LnOx] planes. Here we report a nickel-free cation deficient layered perovskite, (PrBa)0.95(Fe0.9Mo0.1)2O5 + δ (PBFM), for SOFC anode, and this anode shows an outstanding performance with high resistance against both carbon build-up and sulfur poisoning in hydrocarbon fuels. At 800 °C, the layered PBFM showed high electrical conductivity of 59.2 S cm(-1) in 5% H2 and peak power densities of 1.72 and 0.54 W cm(-2) using H2 and CH4 as fuel, respectively. The cell exhibits a very stable performance under a constant current load of 1.0 A cm(-2). To our best knowledge, this is the highest performance of ceramic anodes operated in methane. In addition, the anode is structurally stable at various fuel and temperature conditions, suggesting that it is a feasible material candidate for high-performing SOFC anode. PMID:26648509

  2. A High-Performing Sulfur-Tolerant and Redox-Stable Layered Perovskite Anode for Direct Hydrocarbon Solid Oxide Fuel Cells

    NASA Astrophysics Data System (ADS)

    Ding, Hanping; Tao, Zetian; Liu, Shun; Zhang, Jiujun

    2015-12-01

    Development of alternative ceramic oxide anode materials is a key step for direct hydrocarbon solid oxide fuel cells (SOFCs). Several lanthanide based layered perovskite-structured oxides demonstrate outstanding oxygen diffusion rate, favorable electronic conductivity, and good oxygen surface exchange kinetics, owing to A-site ordered structure in which lanthanide and alkali-earth ions occupy alternate (001) layers and oxygen vacancies are mainly located in [LnOx] planes. Here we report a nickel-free cation deficient layered perovskite, (PrBa)0.95(Fe0.9Mo0.1)2O5 + δ (PBFM), for SOFC anode, and this anode shows an outstanding performance with high resistance against both carbon build-up and sulfur poisoning in hydrocarbon fuels. At 800 °C, the layered PBFM showed high electrical conductivity of 59.2 S cm-1 in 5% H2 and peak power densities of 1.72 and 0.54 W cm-2 using H2 and CH4 as fuel, respectively. The cell exhibits a very stable performance under a constant current load of 1.0 A cm-2. To our best knowledge, this is the highest performance of ceramic anodes operated in methane. In addition, the anode is structurally stable at various fuel and temperature conditions, suggesting that it is a feasible material candidate for high-performing SOFC anode.

  3. Arsenic trioxide-mediated growth inhibition in gallbladder carcinoma cells via down-regulation of Cyclin D1 transcription mediated by Sp1 transcription factor

    SciTech Connect

    Ai, Zhilong; Lu, Weiqi; Ton, Saixiong; Liu, Houbao; Sou, Tao; Shen, Zhenbin; Qin, Xinyu . E-mail: smc_jjh@yahoo.com.cn

    2007-08-31

    Gallbladder carcinoma (GBC), an aggressive and mostly lethal malignancy, is known to be resistant to a number of drug stimuli. Here, we demonstrated that arsenic trioxide inhibited the proliferation of gallbladder carcinoma in vivo and in vitro as well as the transcription of cell cycle-related protein Cyclin D1. And, Cyclin D1 overexpression inhibited the negative role of arsenic trioxide in cell cycle progression. We further explored the mechanisms by which arsenic trioxide affected Cyclin D1 transcription and found that the Sp1 transcription factor was down-regulated by arsenic trioxide, with a corresponding decrease in Cyclin D1 promoter activity. Taken together, these results suggested that arsenic trioxide inhibited gallbladder carcinoma cell proliferation via down-regulation of Cyclin D1 transcription in a Sp1-dependent manner, which provided a new mechanism of arsenic trioxide-involved cell proliferation and may have important therapeutic implications in gallbladder carcinoma patients.

  4. Influence of Sulfur Species on Current Efficiency in the Aluminum Smelting Process

    NASA Astrophysics Data System (ADS)

    Meirbekova, Rauan; Haarberg, Geir Martin; Thonstad, Jomar; Saevarsdottir, Gudrun

    2016-04-01

    Anode impurities are the major source of sulfur in aluminum electrolysis. Sulfur in anodes is mainly found as organic compounds. Alumina also introduces small quantities of sulfur, typically in the form of sulfates. The scarcity and cost of low-sulfur raw materials and the possibility of sulfur removal from the cell by means of flue gas may make high-sulfur content anodes a viable option. However, some anode impurities are known to affect current efficiency in aluminum production and caution must be exercised. The effect of increased sulfur content in the aluminum electrolysis electrolyte must be studied. This paper explores the effect of increased sulfur concentration in the electrolyte on current efficiency in a laboratory cell. Sodium sulfate was added to the electrolyte as a source of sulfur at regular time intervals to maintain a constant sulfur concentration. Current efficiency decreased by 1.1 pct per each 100 mg/kg (ppm) increase in sulfur concentration in the electrolyte.

  5. Low Temperature Sorbents for removal of Sulfur Compounds from fluid feed Streams

    SciTech Connect

    Siriwardane, Ranjan

    1999-09-30

    A sorbent material is provided comprising a material reactive with sulfur, a binder unreactive with sulfur and an inert material, wherein the sorbent absorbs the sulfur at temperatures between 30 and 200 C. Sulfur absorption capacity as high as 22 weight percent has been observed with these materials.

  6. Low Temperature Sorbents for Removal of Sulfur Compounds from Fluid Feed Streams

    DOEpatents

    Siriwardane, Ranjani

    2004-06-01

    A sorbent material is provided comprising a material reactive with sulfur, a binder unreactive with sulfur and an inert material, wherein the sorbent absorbs the sulfur at temperatures between 30 and 200 C. Sulfur absorption capacity as high as 22 weight percent has been observed with these materials.

  7. Catalyst for elemental sulfur recovery process

    DOEpatents

    Flytzani-Stephanopoulos, M.; Liu, W.

    1995-01-24

    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

  8. Sulfur dimers adsorbed on Au(111) as building blocks for sulfur octomers formation: A density functional study

    SciTech Connect

    Hernandez-Tamargo, Carlos E.; Montero-Alejo, Ana Lilian; Pujals, Daniel Codorniu; Mikosch, Hans

    2014-07-28

    Experimental scanning tunneling microscopy (STM) studies have shown for more than two decades rectangular formations when sulfur atoms are deposited on Au(111) surfaces. The precursors have ranged from simple molecules or ions, such as SO{sub 2} gas or sulfide anions, to more complex organosulfur compounds. We investigated, within the framework of the Density Functional Theory, the structure of these rectangular patterns assuming them entirely composed of sulfur atoms as the experimental evidence suggests. The sulfur coverage at which the simulations were carried out (0.67 ML or higher) provoked that the sulfur-sulfur association had to be taken into account for achieving a good agreement between the sets of simulated and experimental STM images. A combination of four sulfur dimers per rectangular formation properly explained the trends obtained by the experimental STM analysis which were related with the rectangles' size and shape fluctuations together with sulfur-sulfur distances within these rectangles. Finally, a projected density of states analysis showed that the dimers were capable of altering the Au(5d) electronic states at the same level as atomic sulfur adsorbed at low coverage. Besides, sulfur dimers states were perfectly distinguished, whose presence near and above the Fermi level can explain both: sulfur-sulfur bond elongation and dimers stability when they stayed adsorbed on the surface at high coverage.

  9. Effects of high salinity and constituent organic compounds on treatment of photo-processing waste by a sulfur-oxidizing bacteria/granular activated carbon sludge system.

    PubMed

    Lin, Bin-Le; Hosomi, Masaaki; Murakami, Akihiko

    2002-02-01

    To achieve practical treatment of photo-processing waste (PW) using our previously proposed sulfur-oxidizing bacteria (SOB)/granular activated carbon (GAC) sludge system, this paper elucidates why 3- to 5-X dilution of PW was required. That is, a series of experiments were carried out to show the effects of high salinity and constituent organic compounds in PW, respectively. Both an inorganic salts system and calcination PW system showed that SOB completely oxidizes S2O(3)2- -S to SO(4)2- -S even at 12.3 or 13.6% salinity, respectively; hence the dilution requirement is not attributable to high salinity. In experiments employing SOB and SOB/GAC systems to investigate the effects of 23 constituent compounds in PW, compounds were classified into Groups I, II, IIIa, and IIIb. Even with 10 g/l GAC, the nine compounds in Group IIIb still exhibited a toxic effect on SOB activity at 1- and 3-X dilutions; thus it is these compounds that are responsible for requiring dilution of PW. Accordingly, a reduction in their use within the photodeveloping and fix-stabilizing industry, and/or use of > 10g/l GAC, are new considerations for establishing a more practical PW treatment process.

  10. Generation of Sulfur-rich, Sulfur-undersaturated Basaltic Melts in Oxidized Arc Sources.

    NASA Astrophysics Data System (ADS)

    Jugo, P. J.; Luth, R. W.; Richards, J. P.

    2003-12-01

    Although sulfur is a minor element in the Earth, it has a disproportionate impact because it commonly occurs as sulfide. Sulfides largely control the behavior of chalcophile (e.g., Cu, Ni) and highly siderophile elements (Ru, Rh, Pd, Re, Os, Ir, Pt, and Au) that are of interest because either they are economically important or because they provide valuable information about geochemical processes. Island arc basalts are more oxidized than basalts from other tectonic settings and therefore, in these settings, sulfur maybe present not as sulfide but as sulfate. In addition to the impact on the behavior of chalcophile and siderophile elements, sulfur speciation as sulfate may have a role on the occurrence of sulfur-rich explosive volcanism, which has been linked to significant short-term variations in global climate. However, little is known about the range in oxygen fugacity for the transition from solubility as sulfide to solubility as sulfate. We used experimental data on the solubility of sulfur in basaltic melts saturated with either sulfide or sulfate at different oxygen fugacities to model this transition. Our model shows that the ten-fold increase in the solubility of sulfur (from 0.14 wt.% to 1.5 wt.%) observed experimentally occurs at oxygen fugacities between ˜FMQ+1 and ˜FMQ+2, conditions under which many arc magmas are thought to be generated. The increase in the solubility of sulfur with increasing oxygen fugacity implies that in oxidized arc sources very low degrees of partial melting are sufficient to generate basaltic melts that are simultaneously sulfur-rich and sulfur-undersaturated. In the absence of sulfides, oxides and metallic alloys may influence the behavior of some (but not all) the highly siderophile elements whereas the chalcophile and some siderophile elements become incompatible. As a consequence, melting of oxidized sources in which sulfides are not stable would favor incorporation of metals such as Cu, Ni, Au and Pd in the melts and

  11. Synthesis and development of processes for the recovery of sulfur from acid gases. Part 1, Development of a high-temperature process for removal of H{sub 2}S from coal gas using limestone -- thermodynamic and kinetic considerations; Part 2, Development of a zero-emissions process for recovery of sulfur from acid gas streams

    SciTech Connect

    Towler, G.P.; Lynn, S.

    1993-05-01

    Limestone can be used more effectively as a sorbent for H{sub 2}S in high-temperature gas-cleaning applications if it is prevented from undergoing calcination. Sorption of H{sub 2}S by limestone is impeded by sintering of the product CaS layer. Sintering of CaS is catalyzed by CO{sub 2}, but is not affected by N{sub 2} or H{sub 2}. The kinetics of CaS sintering was determined for the temperature range 750--900{degrees}C. When hydrogen sulfide is heated above 600{degrees}C in the presence of carbon dioxide elemental sulfur is formed. The rate-limiting step of elemental sulfur formation is thermal decomposition of H{sub 2}S. Part of the hydrogen thereby produced reacts with CO{sub 2}, forming CO via the water-gas-shift reaction. The equilibrium of H{sub 2}S decomposition is therefore shifted to favor the formation of elemental sulfur. The main byproduct is COS, formed by a reaction between CO{sub 2} and H{sub 2}S that is analogous to the water-gas-shift reaction. Smaller amounts of SO{sub 2} and CS{sub 2} also form. Molybdenum disulfide is a strong catalyst for H{sub 2}S decomposition in the presence of CO{sub 2}. A process for recovery of sulfur from H{sub 2}S using this chemistry is as follows: Hydrogen sulfide is heated in a high-temperature reactor in the presence of CO{sub 2} and a suitable catalyst. The primary products of the overall reaction are S{sub 2}, CO, H{sub 2} and H{sub 2}O. Rapid quenching of the reaction mixture to roughly 600{degrees}C prevents loss Of S{sub 2} during cooling. Carbonyl sulfide is removed from the product gas by hydrolysis back to CO{sub 2} and H{sub 2}S. Unreacted CO{sub 2} and H{sub 2}S are removed from the product gas and recycled to the reactor, leaving a gas consisting chiefly of H{sub 2} and CO, which recovers the hydrogen value from the H{sub 2}S. This process is economically favorable compared to the existing sulfur-recovery technology and allows emissions of sulfur-containing gases to be controlled to very low levels.

  12. Sulfide catalysts for reducing SO2 to elemental sulfur

    DOEpatents

    Jin, Yun; Yu, Qiquan; Chang, Shih-Ger

    2001-01-01

    A highly efficient sulfide catalyst for reducing sulfur dioxide to elemental sulfur, which maximizes the selectivity of elemental sulfur over byproducts and has a high conversion efficiency. Various feed stream contaminants, such as water vapor are well tolerated. Additionally, hydrogen, carbon monoxide, or hydrogen sulfides can be employed as the reducing gases while maintaining high conversion efficiency. This allows a much wider range of uses and higher level of feed stream contaminants than prior art catalysts.

  13. Metal-Sulfur Battery Cathodes Based on PAN-Sulfur Composites.

    PubMed

    Wei, Shuya; Ma, Lin; Hendrickson, Kenville E; Tu, Zhengyuan; Archer, Lynden A

    2015-09-23

    Sulfur/polyacrylonitrile composites provide a promising route toward cathode materials that overcome multiple, stubborn technical barriers to high-energy, rechargeable lithium-sulfur (Li-S) cells. Using a facile thermal synthesis procedure in which sulfur and polyacrylonitrile (PAN) are the only reactants, we create a family of sulfur/PAN (SPAN) nanocomposites in which sulfur is maintained as S3/S2 during all stages of the redox process. By entrapping these smaller molecular sulfur species in the cathode through covalent bonding to and physical confinement in a conductive host, these materials are shown to completely eliminate polysulfide dissolution and shuttling between lithium anode and sulfur cathode. We also show that, in the absence of any of the usual salt additives required to stabilize the anode in traditional Li-S cells, Li-SPAN cells cycle trouble free and at high Coulombic efficiencies in simple carbonate electrolytes. Electrochemical and spectroscopic analysis of the SPAN cathodes at various stages of charge and discharge further show a full and reversible reduction and oxidation between elemental sulfur and Li-ions in the electrolyte to produce Li2S as the only discharge product over hundreds of cycles of charge and discharge at fixed current densities. PMID:26325146

  14. Metal-Sulfur Battery Cathodes Based on PAN-Sulfur Composites.

    PubMed

    Wei, Shuya; Ma, Lin; Hendrickson, Kenville E; Tu, Zhengyuan; Archer, Lynden A

    2015-09-23

    Sulfur/polyacrylonitrile composites provide a promising route toward cathode materials that overcome multiple, stubborn technical barriers to high-energy, rechargeable lithium-sulfur (Li-S) cells. Using a facile thermal synthesis procedure in which sulfur and polyacrylonitrile (PAN) are the only reactants, we create a family of sulfur/PAN (SPAN) nanocomposites in which sulfur is maintained as S3/S2 during all stages of the redox process. By entrapping these smaller molecular sulfur species in the cathode through covalent bonding to and physical confinement in a conductive host, these materials are shown to completely eliminate polysulfide dissolution and shuttling between lithium anode and sulfur cathode. We also show that, in the absence of any of the usual salt additives required to stabilize the anode in traditional Li-S cells, Li-SPAN cells cycle trouble free and at high Coulombic efficiencies in simple carbonate electrolytes. Electrochemical and spectroscopic analysis of the SPAN cathodes at various stages of charge and discharge further show a full and reversible reduction and oxidation between elemental sulfur and Li-ions in the electrolyte to produce Li2S as the only discharge product over hundreds of cycles of charge and discharge at fixed current densities.

  15. Torsades de pointes in 3 patients with leukemia treated with arsenic trioxide.

    PubMed

    Unnikrishnan, D; Dutcher, J P; Varshneya, N; Lucariello, R; Api, M; Garl, S; Wiernik, P H; Chiaramida, S

    2001-03-01

    Arsenic trioxide is used in clinical trials in the treatment of relapsed and resistant cases of acute promyelocytic leukemia. Adverse effects from arsenic in these studies have been multisystemic. Arsenic is known to cause corrected QT-interval prolongation and T-wave changes, but the potential for serious ventricular arrhythmias is less well understood. Torsades de pointes, a form of ventricular tachycardia, has been reported with arsenic poisoning but not at therapeutic doses used in protocols for hematologic malignancies. We describe 3 patients in whom this arrhythmia developed while they were treated with arsenic trioxide. Early recognition of the arrhythmia or correction of contributory factors is important because arsenic induced ventricular arrhythmias are known to be resistant to most chemical methods and electrical cardioversion.

  16. Summary of the Preliminary Analysis of Savannah River Depleted Uranium Trioxide

    SciTech Connect

    NSTec Environmental Management

    2010-10-13

    This report summarizes a preliminary special analysis of the Savannah River Depleted Uranium Trioxide waste stream (SVRSURANIUM03, Revision 2). The analysis is considered preliminary because a final waste profile has not been submitted for review. The special analysis is performed to determine the acceptability of the waste stream for shallow land burial at the Area 5 Radioactive Waste Management Site (RWMS) at the Nevada National Security Site (NNSS). The Savannah River Depleted Uranium Trioxide waste stream requires a special analysis because the waste stream’s sum of fractions exceeds one. The 99Tc activity concentration is 98 percent of the NNSS Waste Acceptance Criteria and the largest single contributor to the sum of fractions.

  17. Nitrogen oxides, sulfur trioxide, and mercury emissions during oxy-fuel fluidized bed combustion of Victorian brown coal.

    PubMed

    Roy, Bithi; Chen, Luguang; Bhattacharya, Sankar

    2014-12-16

    This study investigates, for the first time, the NOx, N2O, SO3, and Hg emissions from combustion of a Victorian brown coal in a 10 kWth fluidized bed unit under oxy-fuel combustion conditions. Compared to air combustion, lower NOx emissions and higher N2O formation were observed in the oxy-fuel atmosphere. These NOx reduction and N2O formations were further enhanced with steam in the combustion environment. The NOx concentration level in the flue gas was within the permissible limit in coal-fired power plants in Victoria. Therefore, an additional NOx removal system will not be required using this coal. In contrast, both SO3 and gaseous mercury concentrations were considerably higher under oxy-fuel combustion compared to that in the air combustion. Around 83% of total gaseous mercury released was Hg(0), with the rest emitted as Hg(2+). Therefore, to control harmful Hg(0), a mercury removal system may need to be considered to avoid corrosion in the boiler and CO2 separation units during the oxy-fuel fluidized-bed combustion using this coal. PMID:25402169

  18. Nitrogen oxides, sulfur trioxide, and mercury emissions during oxy-fuel fluidized bed combustion of Victorian brown coal.

    PubMed

    Roy, Bithi; Chen, Luguang; Bhattacharya, Sankar

    2014-12-16

    This study investigates, for the first time, the NOx, N2O, SO3, and Hg emissions from combustion of a Victorian brown coal in a 10 kWth fluidized bed unit under oxy-fuel combustion conditions. Compared to air combustion, lower NOx emissions and higher N2O formation were observed in the oxy-fuel atmosphere. These NOx reduction and N2O formations were further enhanced with steam in the combustion environment. The NOx concentration level in the flue gas was within the permissible limit in coal-fired power plants in Victoria. Therefore, an additional NOx removal system will not be required using this coal. In contrast, both SO3 and gaseous mercury concentrations were considerably higher under oxy-fuel combustion compared to that in the air combustion. Around 83% of total gaseous mercury released was Hg(0), with the rest emitted as Hg(2+). Therefore, to control harmful Hg(0), a mercury removal system may need to be considered to avoid corrosion in the boiler and CO2 separation units during the oxy-fuel fluidized-bed combustion using this coal.

  19. ELECTRON IRRADIATION OF CARBON DISULFIDE-OXYGEN ICES: TOWARD THE FORMATION OF SULFUR-BEARING MOLECULES IN INTERSTELLAR ICES

    SciTech Connect

    Maity, Surajit; Kaiser, Ralf I.

    2013-08-20

    The formation of sulfur-bearing molecules in interstellar ices was investigated during the irradiation of carbon disulfide (CS{sub 2})-oxygen (O{sub 2}) ices with energetic electrons at 12 K. The irradiation-induced chemical processing of these ices was monitored online and in situ via Fourier transform infrared spectroscopy to probe the newly formed products quantitatively. The sulfur-bearing molecules produced during the irradiation were sulfur dioxide (SO{sub 2}), sulfur trioxide (SO{sub 3}), and carbonyl sulfide (OCS). Formations of carbon dioxide (CO{sub 2}), carbon monoxide (CO), and ozone (O{sub 3}) were observed as well. To fit the temporal evolution of the newly formed products and to elucidate the underlying reaction pathways, kinetic reaction schemes were developed and numerical sets of rate constants were derived. Our studies suggest that carbon disulfide (CS{sub 2}) can be easily transformed to carbonyl sulfide (OCS) via reactions with suprathermal atomic oxygen (O), which can be released from oxygen-containing precursors such as water (H{sub 2}O), carbon dioxide (CO{sub 2}), and/or methanol (CH{sub 3}OH) upon interaction with ionizing radiation. This investigation corroborates that carbonyl sulfide (OCS) and sulfur dioxide (SO{sub 2}) are the dominant sulfur-bearing molecules in interstellar ices.

  20. An improved method for retrospective quantification of sulfur mustard exposure by detection of its albumin adduct using ultra-high pressure liquid chromatography-tandem mass spectrometry.

    PubMed

    Liu, ChangCai; Liang, LongHui; Xiang, Yu; Yu, HuiLan; Zhou, ShiKun; Xi, HaiLing; Liu, ShiLei; Liu, JingQuan

    2015-09-01

    Sulfur mustard (HD) adduct to human serum albumin (ALB) at Cys-34 residue has become an important and long-term retrospective biomarker of HD exposure. Here, a novel, sensitive, and convenient approach for retrospective quantification of HD concentration exposed to plasma was established by detection of the HD-ALB adduct using ultra-high pressure liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) with a novel non-isotope internal standard (IS). The HD-ALB adduct was isolated from HD-exposed plasma with blue Sepharose. The adduct was digested with proteinase K to form sulfur-hydroxyethylthioethyl ([S-HETE])-Cys-Pro-Phe tripeptide biomarker. The tripeptide adduct could be directly analyzed by UHPLC-MS/MS without an additional solid phase extraction (SPE), which was considered as a critical procedure in previous methods. The easily available 2-chloroethyl ethylsulfide (2-CEES) as HD surrogate was first reported to be used as IS in place of traditional d8-HD for quantification of HD exposure. Furthermore, 2-CEES was also confirmed to be a good IS alternative for quantification of HD exposure by investigation of product ion spectra for their corresponding tripeptide adducts which exhibited identical MS/MS fragmentation behaviors. The method was found to be linear between 1.00 and 250 ng•mL(-1) HD exposure (R(2)>0.9989) with precision of <4.50% relative standard deviation (%RSD), accuracy range between 96.5% and 114%, and a calculated limit of detection (LOD) of 0.532 ng•mL(-1). The lowest reportable limit (LRL) is 1.00 ng•mL(-1), over seven times lower than that of the previous method. The entire method required only 0.1 mL of plasma sample and took under 7 h without special sample preparation equipment. It is proven to be a sensitive, simple, and rugged method, which is easily applied in international laboratories to improve the capabilities for the analysis of biomedical samples related to verification of the Chemical Weapon Convention (CWC).