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Sample records for sulfur content

  1. Determination of sulfur content in fuels

    International Nuclear Information System (INIS)

    Daucik, P.; Zidek, Z.; Kalab, P.

    1998-01-01

    The sulfur content in fuels, Diesel fuels, and in the solutions of dibutylsulfide in a white oil was determined by various methods. The results obtained by elemental analysis have shown that the method is not advisable for the determination of sulfur in fuels. A good agreement was found by comparing the results in the determination of the sulfur by Grote-Krekeler's and Hermann-Moritz's methods and by the energy-dispersive X-ray fluorescence analysis. The last method is the modern, comfortable, and timesaving method enabling the fast and precise determination of sulfur contents in the various types of samples. (authors)

  2. Dew point of gases with low sulfuric acid content

    Energy Technology Data Exchange (ETDEWEB)

    Fieg, J.

    1981-07-01

    Discusses control of air pollution caused by sulfur compounds in solid fuels during combustion. Excessive amount of oxygen during combustion leads to formation of sulfur trioxide. Sulfur trioxide reacts with water vapor and forms sulfuric acid. Chemical reactions which lead to formation of sulfuric acid are described. Conditions for sulfuric acid condensation are analyzed. Several methods for determining dew point of flue gases with low sulfuric acid content are reviewed: methods based on determination of electric conductivity of condensed sulfuric acid (Francis, Cheney, Kiyoure), method based on determination of sulfuric acid concentration in the gaseous phase and in the liquid phase after cooling (Lee, Lisle and Sensenbaugh, Ross and Goksoyr). (26 refs.) (In Polish)

  3. Experiments on contrail formation from fuels with different sulfur content

    Energy Technology Data Exchange (ETDEWEB)

    Busen, R; Kuhn, M; Petzold, A; Schroeder, F; Schumann, U [Deutsche Forschungs- und Versuchsanstalt fuer Luft- und Raumfahrt e.V., Oberpfaffenhofen (Germany); Baumgardner, D [National Center for Atmospheric Research, Boulder, CO (United States); Borrmann, S [Mainz Univ. (Germany); Hagen, D; Whitefield, Ph [Missouri Univ., Rolla, MO (United States). Bureau of Mines; Stroem, J [Stockholm Univ. (Sweden)

    1998-12-31

    A series of both flight tests and ground experiments has been performed to evaluate the role of the sulfur contained in kerosene in condensation trail (contrail) formation processes. The results of the first experiments are compiled briefly. The last SULFUR 4 experiment dealing with the influence of the fuel sulfur content and different appertaining conditions is described in detail. Different sulfur mass fractions lead to different particle size spectra. The number of ice particles in the contrail increases by about a factor of 2 for 3000 ppm instead of 6 ppm sulfur fuel content. (author) 10 refs.

  4. Experiments on contrail formation from fuels with different sulfur content

    Energy Technology Data Exchange (ETDEWEB)

    Busen, R.; Kuhn, M.; Petzold, A.; Schroeder, F.; Schumann, U. [Deutsche Forschungs- und Versuchsanstalt fuer Luft- und Raumfahrt e.V., Oberpfaffenhofen (Germany); Baumgardner, D. [National Center for Atmospheric Research, Boulder, CO (United States); Borrmann, S. [Mainz Univ. (Germany); Hagen, D.; Whitefield, Ph. [Missouri Univ., Rolla, MO (United States). Bureau of Mines; Stroem, J. [Stockholm Univ. (Sweden)

    1997-12-31

    A series of both flight tests and ground experiments has been performed to evaluate the role of the sulfur contained in kerosene in condensation trail (contrail) formation processes. The results of the first experiments are compiled briefly. The last SULFUR 4 experiment dealing with the influence of the fuel sulfur content and different appertaining conditions is described in detail. Different sulfur mass fractions lead to different particle size spectra. The number of ice particles in the contrail increases by about a factor of 2 for 3000 ppm instead of 6 ppm sulfur fuel content. (author) 10 refs.

  5. Relationship of sulfur content of soils and plants

    Energy Technology Data Exchange (ETDEWEB)

    Hengl, F; Reckendorfer, P

    1928-01-01

    Crops were fertilized with fertilizers which contained chloride and sulfate in order to examine how the sulfur content of a plant may be affected by that of the soil. At the time of flowering the respective chlorine or sulfate content of the plants was considerably above that of the controls; differences were less, however, when the plants were fully mature. Sulfate, in particular, was little different. In field observations, little correlation was noted between sulfate content of plants and soils. Natural variations in the sulfur content of plants were greater than the increases attributable to smoke air pollution. 2 tables.

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

    Science.gov (United States)

    Vetter, R.D.; Fry, B.

    1998-01-01

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

  7. Determining total sulfur content in coal by MSC radiometric sulfur meter

    Energy Technology Data Exchange (ETDEWEB)

    Czerw, B; Sikora, T; Golebiowski, W

    1976-01-01

    The MSC radiometric sulfur meter is used to determine total sulfur content in brown and black coals. Sulfur content is determined by measuring intensity of radiation beam which has travelled through a coal sample with the optimum constant surface mass. Construction of the MSC, consisting of a measuring head and the electronic measuring system, is shown in a scheme. AM-241 (with activity of 50 mCi) is the source of radiation. Energy of 25.3 keV (tin disc) is selected as the optimum. The SSU-70 probe with NaJ/Tl crystal is the radiation detector. The black coal sample weighs 10 g and the brown coal sample weighs 18 g. Duration of sulfur determination is 10 min. Error of sulfur determination ranges from plus or minus 0.2% to 0.3%. The results of operational tests of MSC radiometric sulfur meters in black and brown coal mines are discussed. Accuracy of measurement is shown in 5 tables. (8 refs.)

  8. Effect of sulfur content in a sulfur-activated carbon composite on the electrochemical properties of a lithium/sulfur battery

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jin-Woo; Kim, Changhyeon; Ryu, Ho-Suk; Cho, Gyu-Bong; Cho, Kwon-Koo; Kim, Ki-Won [School of Materials Science and Engineering, Gyeongsang National University, Jinju (Korea, Republic of); Ahn, Jou-Hyeon [Department of Chemical & Biological Engineering, Gyeongsang National University, Jinju (Korea, Republic of); Wang, Guoxiu [School of Chemistry and Forensic Science, University of Technology Sydney, Sydney, NSW 2007 (Australia); Ahn, Jae-Pyeung [Advanced Analysis Center, Research Planning & Coordination Division, KIST, Seoul (Korea, Republic of); Ahn, Hyo-Jun, E-mail: ahj@gnu.ac.kr [School of Materials Science and Engineering, Gyeongsang National University, Jinju (Korea, Republic of)

    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)

  9. Sulfur dioxide content of the air and its influence on the plant

    Energy Technology Data Exchange (ETDEWEB)

    Koeck, G; Reckendorfer, P; Beran, F

    1929-01-01

    Clover was exposed to concentrations of sulfur dioxide ranging from 5 to 50 ppm for periods of 1 to 4 hours. The higher concentrations caused an increase in sulfur content. Single exposures did not affect the digestible protein content of the plants. 10 tables, 3 figures.

  10. In-situ sulfuration synthesis of sandwiched spherical tin sulfide/sulfur-doped graphene composite with ultra-low sulfur content

    Science.gov (United States)

    Zhao, Bing; Yang, Yaqing; Wang, Zhixuan; Huang, Shoushuang; Wang, Yanyan; Wang, Shanshan; Chen, Zhiwen; Jiang, Yong

    2018-02-01

    SnS is widely studied as anode materials since of its superior structural stability and physicochemical property comparing with other Sn-based composites. Nevertheless, the inconvenience of phase morphology control and excessive consumption of sulfur sources during synthesis hinder the scalable application of SnS nanocomposites. Herein, we report a facile in-situ sulfuration strategy to synthesize sandwiched spherical SnS/sulfur-doped graphene (SnS/S-SG) composite. An ultra-low sulfur content with approximately stoichiometric ratio of Sn:S can effectively promote the sulfuration reaction of SnO2 to SnS and simultaneous sulfur-doping of graphene. The as-prepared SnS/S-SG composite shows a three-dimensional interconnected spherical structure as a whole, in which SnS nanoparticles are sandwiched between the multilayers of graphene sheets forming a hollow sphere. The sandwiched sphere structure and high S doping amount can improve the binding force between SnS and graphene, as well as the structural stability and electrical conductivity of the composite. Thus, a high reversibility of conversion reaction, promising specific capacity (772 mAh g-1 after 100 cycles at 0.1 C) and excellent rate performance (705 and 411 mAh g-1 at 1 C and 10 C, respectively) are exhibited in the SnS/S-SG electrode, which are much higher than that of the SnS/spherical graphene synthesized by traditional post-sulfuration method.

  11. Influence of initial sulfur content in precursor solution for the growth of molybdenum disulfide

    Science.gov (United States)

    Tan, A. L.; Ng, S. S.; Abu Hassan, H.

    2018-04-01

    This work investigated the influence of initial sulfur content in the precursor solution for the growth of molybdenum disulfide (MoS2) films by thermal vapour sulfurization (TVS) with sol-gel spin coating as pre-deposition technique. The early introduction of sulfur shows the presence of grains are uniformly distributed and homogeneous on the surface of the film. MoS2 (002) planes are detected for both films with and without initial sulfur conditions, however, the presence of initial sulfur contents gives slightly higher intensity of diffraction peak. Two phonon modes for MoS2, namely the E2g 1 (in-plane) and the A1g (out-of plane), are well detected from which the frequency difference of Raman peaks between E2g 1 and A1g suggest the grown MoS2 consisted of multi-layers. There is a slight shift of E2g 1 which is caused by the carbon impurities but no shift for A1g. Besides, MoS2 film with the presence of initial sulfur content shows better crystal as indicated by its narrower Raman peaks linewidth. Two broad absorption peaks of MoS2 are detected at 614nm and 665nm. Hence, the early introduction of sulfur content in prepared precursor solution is one way of optimizing the growth of MoS2 films.

  12. Use of the Moessbauer effect for determining pyritic sulfur content in coal

    Energy Technology Data Exchange (ETDEWEB)

    Czerw, B; Sikora, T

    1986-10-01

    This paper discusses investigations into resonance absorption of gamma radiation. Standard equipment for measuring the Moessbauer effect in black coal consisting of a measuring head, the SM-4T spectrometer, a multichannel analyzer, the Standard electronic unit and a printer is evaluated. The MSP measuring system developed jointly by the EMAG Mine Automation Company and the Nuclear Research Institute in Swierk is described. The MSP equipment is used for measuring content of pyritic sulfur in coal. Its accuracy is satisfactory. Results of measuring pyritic and total sulfur content by means of quantitative chemical analysis and by the MSP resonance absorption method (Moessbauer effect) are compared. The mean standard deviation for pyritic sulfur is 0.14% and for total sulfur content 0.21%. 11 refs.

  13. The economic impact of strengthening fuel quality regulation-reducing sulfur content in diesel fuel

    International Nuclear Information System (INIS)

    Chang, H.J.; Cho, G.L.; Kim, Y.D.

    2006-01-01

    This paper investigates the impact of strengthening vehicle emission regulation on economic activities. The government attempts to use three regulation measures to protect air quality from transportation emission. The measures include the aggregate limit (bubbles), the vehicle emission standard, and the fuel quality standard. Especially, we focus on the economic impact of reducing sulfur content in diesel fuel quality standard. Sulfur content in diesel fuel is one of the main factors in worsening local air quality. The emission from diesel vehicle accounts for 51.8% of total vehicle emission in Korea. If sulfur content reduction regulation is implemented, then the petroleum industry should build more facility to produce low sulfur content diesel, leading to additional production costs and increasing prices and decreasing outputs. We use computable general equilibrium model to analyze how the sulfur reduction regulation affects economic activities and trace out local emission reduction cost and GDP loss. And we suggest the tax-recycling mechanism to mitigate the negative economic costs due to the sulfur reduction regulation

  14. Monitoring the sulfur content of coal streams by thermal-neutron-capture gamma-ray analysis

    International Nuclear Information System (INIS)

    Martin, J.W.; Hall, A.W.

    1976-07-01

    A theory was developed for evaluating a complex, prompt gamma ray spectrum to serve as the basis for an instrument to monitor continuously the sulfur content of tonnage streams of coal. Equations for the energies and intensities of prompt gamma rays emitted from 13 most significant elements in coal are combined into a single equation that defines the basic electronic design of the meter. The sulfur content of up to 10 tons per hour of coal was determined in pilot plant tests with a prototype meter. The precision of 0.04 percent sulfur substantiates the validity of the theory. In subsequent industrial plant tests the precision was determined to be a comparable 0.05 percent sulfur

  15. Sulfur content measurement in coal by X-ray fluorescence method

    International Nuclear Information System (INIS)

    Cechak, T.; Thinova, L.

    2001-01-01

    X-ray fluorescence, using backscattering, was employed in the determination of sulfur content and ash content measurement in coal. The results of the methods are given to illustrate the differences between the chemical analysis and X-ray fluorescence method.

  16. 40 CFR 60.4360 - How do I determine the total sulfur content of the turbine's combustion fuel?

    Science.gov (United States)

    2010-07-01

    ... content of the turbine's combustion fuel? 60.4360 Section 60.4360 Protection of Environment ENVIRONMENTAL... Standards of Performance for Stationary Combustion Turbines Monitoring § 60.4360 How do I determine the total sulfur content of the turbine's combustion fuel? You must monitor the total sulfur content of the...

  17. Corrosion fatigue of pressure vessel steels in PWR environments--influence of steel sulfur content

    International Nuclear Information System (INIS)

    Scott, P.M.; Druce, S.G.; Truswell, A.E.

    1984-01-01

    Large effects of simulated light water reactor environments at 288 C on fatigue crack growth in low alloy pressure vessel steels are observed only when specific mechanical, metallurgical, and electrochemical conditions are satisfied simultaneously. In this paper, the relative importance of three key variables--steel impurity content, water chemistry, and flow rate--and their interaction with loading rate or strain rate are examined. In particular, the results of a systematic examination of the influence of a steel's sulfur content are described

  18. Effects of sulfur and aromatic contents in gasoline on motorcycle emissions

    Science.gov (United States)

    Yao, Yung-Chen; Tsai, Jiun-Horng; Chang, An-Lin; Jeng, Fu-Tien

    By investigating the effect of sulfur and aromatic contents in gasoline on the criteria pollutant emissions [CO, total hydrocarbons (THCs), and NO x] and on air toxics in the exhaust from a non-catalyst four-stroke motorcycle engine, inferences can be made concerning the effect of fuel composition on motorcycle emissions. The fuels were blended with different contents of sulfur (40 and 150 ppmw) and aromatics (20 and 30 vol%). The data indicate that the sulfur content does not correlate with the emissions of the criteria pollutants from the catalyst free engine. Instead, lowering aromatic content in gasoline reduced the THC emission by over 30%, especially in the cruising test. The NO x emission, however, showed an inverse correlation with the aromatic content in gasoline. While a reduction of aromatic content in gasoline may decrease emissions of benzene and toluene, it will increase the emission of aldehyde. Since the percentage changes of emission factor of THC and air toxics in the motorcycle were larger than those in passenger cars, the benefit of emission reduction due to fuel composition changes in motorcycles may have significant impacts in health risk analysis.

  19. Determination of uranium content in phosphoric and sulfuric acids used by the phosphatized fertilizers industry

    International Nuclear Information System (INIS)

    Ramos, M.M.O.

    1984-05-01

    Uranium content in phosphoric and sulfuric acids is determined. The uranium was measured through the fission track registration technique, using Makrofol KG, 10 μg thick, as detector. The so-called 'wet' method was adopted and the acid samples were used directly as irradiation medium. This proceeding showed the advantages of simple sample preparation and avoided the need of changing the acid samples media to nitric medium, as commonly used. The analysis of the sulfuric acid samples showed uranium contents under the detection limit of the technique (4 ppb). The results found for phosphoric acid samples ranged from 31 to 845 ppm, with experimental errors between 7.9 and 9.7%. (Author) [pt

  20. EFFECT OF SOLE AND ASSOCIATIVE ACTIONS OF ELEMENTAL SULFUR AND INOCULATION SULFUR OXIDIZING BACTERIA ON GROWTH AND NUTRIENTS CONTENTS OF PEPPER PLANTS AND THE USED SOILS

    Directory of Open Access Journals (Sweden)

    S. A. Ibrahim

    2011-12-01

    Full Text Available A pot experiment was conducted to study the effect of elemental sulfur (E.S rate (2.5 g/kg soil and sulfur oxidizing bacteria on pepper plant and some chemical properties of two representative soil samples varying in their texture and CaCO3 content. Pepper was grown in Shobrakheet clay loam and Nobaria sandy loam soils for 50 days. Each soil was treated with elemental sulfur (2.5 g kg-1 soil and inoculated with two sulfur oxidizing bacteria (S.O.B. No.8 and S.O.B. ATCC 8158. Elemental sulfur with or without sulfur oxidizing bacteria increased shoot dry weights of pepper plants as compared with control. The highest effect was observed with E.S + ATCC 8158 treatment which resulted in increasing the pepper shoot dry weights from 1.36 to 2.08 g pot-1 with the clay loam soil and from 0.77 to 1.37 g pot-1 with the sandy loam soil. The same treatment resulted in the highest plant content of S, N, P, K and micronutrients.

  1. Corrosion fatigue of pressure vessel steels in PWR environments--influence of steel sulfur content

    Energy Technology Data Exchange (ETDEWEB)

    Scott, P.M.; Druce, S.G.; Truswell, A.E.

    1984-07-01

    Large effects of simulated light water reactor environments at 288 C on fatigue crack growth in low alloy pressure vessel steels are observed only when specific mechanical, metallurgical, and electrochemical conditions are satisfied simultaneously. In this paper, the relative importance of three key variables--steel impurity content, water chemistry, and flow rate--and their interaction with loading rate or strain rate are examined. In particular, the results of a systematic examination of the influence of a steel's sulfur content are described.

  2. Climate and air quality trade-offs in altering ship fuel sulfur content

    Science.gov (United States)

    Partanen, A.-I.; Laakso, A.; Schmidt, A.; Kokkola, H.; Kuokkanen, T.; Pietikäinen, J.-P.; Kerminen, V.-M.; Lehtinen, K. E. J.; Laakso, L.; Korhonen, H.

    2013-08-01

    Aerosol particles from shipping emissions both cool the climate and cause adverse health effects. The cooling effect is, however, declining because of shipping emission controls aiming to improve air quality. We used an aerosol-climate model ECHAM-HAMMOZ to test whether by altering ship fuel sulfur content, the present-day aerosol-induced cooling effect from shipping could be preserved while at the same time reducing premature mortality rates related to shipping emissions. We compared the climate and health effects of a present-day shipping emission scenario with (1) a simulation with strict emission controls in the coastal waters (ship fuel sulfur content of 0.1%) and twofold ship fuel sulfur content compared to current global average of 2.7% elsewhere; and (2) a scenario with global strict shipping emission controls (ship fuel sulfur content of 0.1% in coastal waters and 0.5% elsewhere) roughly corresponding to international agreements to be enforced by the year 2020. Scenario 1 had a slightly stronger aerosol-induced radiative flux perturbation (RFP) from shipping than the present-day scenario (-0.43 W m-2 vs. -0.39 W m-2) while reducing premature mortality from shipping by 69% (globally 34 900 deaths avoided per year). Scenario 2 decreased the RFP to -0.06 W m-2 and annual deaths by 96% (globally 48 200 deaths avoided per year) compared to present-day. A small difference in radiative effect (global mean of 0.04 W m-2) in the coastal regions between Scenario 1 and the present-day scenario imply that shipping emission regulation in the existing emission control areas should not be removed in hope of climate cooling. Our results show that the cooling effect of present-day emissions could be retained with simultaneous notable improvements in air quality, even though the shipping emissions from the open ocean clearly have a significant effect on continental air quality. However, increasing ship fuel sulfur content in the open ocean would violate existing

  3. In-line estimation of sulfur and nitrogen contents during hydrotreating of middle distillates

    Directory of Open Access Journals (Sweden)

    M. E. Pacheco

    2009-12-01

    Full Text Available The main objective of this work is analyzing whether it is possible to develop an empirical correlation for in-line estimation of the sulfur and nitrogen contents of the middle distillates Hydrotreating (HDT products for control purposes. Correlations are based only on readily available in-line information of specific gravity variation between feedstock and products, without considering any piece of information about the kinetic behavior of the catalyst. Experimental data were obtained in pilot plants under operating conditions that are representative of refinery operations. Results indicate that the removal of nitrogen and sulfur compounds during middle distillates HDT can be monitored in-line in real time, based on the available measurements of specific gravity. This allows for development and implementation of advanced in-line procedures for monitoring and control of the HDT process in real time.

  4. Impact of sulfur content regulations of shipping fuel on coastal air quality

    Science.gov (United States)

    Seyler, André; Wittrock, Folkard; Kattner, Lisa; Mathieu-Üffing, Barbara; Weigelt, Andreas; Peters, Enno; Richter, Andreas; Schmolke, Stefan; Burrows, John P.

    2016-04-01

    Shipping traffic is a sector that faces an enormous growth rate and contributes substantially to the emissions from the transportation sector, but lacks regulations and controls. Shipping is not enclosed in the Kyoto Protocol. However, the International Maritime Organization (IMO) introduced sufhur limits for marine heavy fuels, nitrogen oxide limits for newly-built ship engines and established Emission Control Areas (ECA) in the North and Baltic Sea as well as around North America with the International Convention for the Prevention of Pollution from Ships (MARPOL 73/78 Annex VI). Recently, on the 1st of January 2015, the allowed sulfur content of marine fuels inside Sulfur Emission Control Areas has been significantly decreased from 1.0% to 0.1%. However, measurements of reactive trace gases and the chemical composition of the marine troposphere along shipping routes are sparse and up to now there is no regular monitoring system available. The project MeSmarT (measurements of shipping emissions in the marine troposphere) is a cooperation between the University of Bremen, the German Federal Maritime and Hydrographic Agency (Bundesamt für Seeschifffahrt und Hydrographie, BSH) and the Helmholtz-Zentrum Geesthacht. This study aims to analyse the influence of shipping emissions on the coastal air quality by evaluating ground-based remote sensing measurements using the MAX-DOAS (Multi AXis Differential Optical Absorption Spectroscopy) technique. Measurements of the atmospheric trace gases nitrogen dioxide (NO2) and sulfur dioxide (SO2) have been carried out in the marine troposphere at the MeSmarT measurement sites in Wedel and on Neuwerk and on-board several ship cruises on the North and Baltic Sea. The capability of two-channel MAX-DOAS systems to do simultaneous measurements in the UV and visible spectral range has been used in the so called "onion-peeling" approach to derive spatial distributions of ship emissions and to analyse the movement of the exhausted

  5. Prebiotics mitigate in vitro sulfur-containing odour generation in caecal content of pigs

    Directory of Open Access Journals (Sweden)

    Yuan Fan Deng

    2015-03-01

    Full Text Available The objective of this study was to examine the effects and role of prebiotics, such as inulin, fructo-oligosaccharides (FOS and galactooligosaccharides (GAS, to mitigate sulfur-containing odour gases, hydrogen sulfide (H2S and methyl mercaptan (CH3SH using pigs as in vitro study model. Inocula obtained from pigs were incubated at 39°C for 24 h using 550 mg sterilised substrate (caecal contents supplemented with or without 50 mg prebiotics. Production of total gas, H2S and CH3SH were determined. The results showed that total gas production for the caecal content of pigs was 57.3 mL, and that for H2S and CH3SH was 220.2 and 15.2 μL, respectively. The total gas production increased (P<0.05, whereas concentrations of H2S and CH3SH decreased (P<0.05 with supplementation of prebiotics. Among the prebiotics, inulin was the most effective in mitigating H2S and CH3SH productions, reducing the two malodorous gases by 14.7 and 19.8%, respectively. The reduction of the above two sulfur- containing gases was supported by lower sulfate-reducing bacteria population and higher sulfate radical concentrations in the prebiotics, particularly that of inulin supplementation group.

  6. Manipulating ship fuel sulfur content and modeling the effects on air quality and climate

    Science.gov (United States)

    Partanen, Antti-Ilari; Laakso, Anton; Schmidt, Anja; Kokkola, Harri; Kuokkanen, Tuomas; Kerminen, Veli-Matti; Lehtinen, Kari E. J.; Laakso, Lauri; Korhonen, Hannele

    2013-04-01

    Aerosol emissions from international shipping are known to cause detrimental health effects on people mainly via increased lung cancer and cardiopulmonary diseases. On the other hand, the aerosol particles from the ship emissions modify the properties of clouds and are believed to have a significant cooling effect on the global climate. In recent years, aerosol emissions from shipping have been more strictly regulated in order to improve air quality and thus decrease the mortality due to ship emissions. Decreasing the aerosol emissions from shipping is projected to decrease their cooling effect, which would intensify the global warming even further. In this study, we use a global aerosol-climate model ECHAM5.5-HAM2 to test if continental air quality can be improved while still retaining the cooling effect from shipping. The model explicitly resolves emissions of aerosols and their pre-cursor gases. The model also calculates the interaction between aerosol particles and clouds, and can thus predict the changes in cloud properties due to aerosol emissions. We design and simulate a scenario where ship fuel sulfur content is strictly limited to 0.1% near all coastal regions, but doubled in the open oceans from the current global mean value of 2.7% (geo-ships). This scenario is compared to three other simulations: 1) No shipping emissions at all (no-ships), 2) present-day shipping emissions (std-ships) and 3) a future scenario where sulfur content is limited to 0.1% in the coastal zones and to 0.5% in the open ocean (future-ships). Global mean radiative flux perturbation (RFP) in std-ships compared to no-ships is calculated to be -0.4 W m-2, which is in the range of previous estimates for present-day shipping emissions. In the geo-ships simulation the corresponding global mean RFP is roughly equal, but RFP is spatially distributed more on the open oceans, as expected. In future-ships the decreased aerosol emissions provide weaker cooling effect of only -0.1 W m-2. In

  7. Iron solubility related to particle sulfur content in source emission and ambient fine particles.

    Science.gov (United States)

    Oakes, M; Ingall, E D; Lai, B; Shafer, M M; Hays, M D; Liu, Z G; Russell, A G; Weber, R J

    2012-06-19

    The chemical factors influencing iron solubility (soluble iron/total iron) were investigated in source emission (e.g., biomass burning, coal fly ash, mineral dust, and mobile exhaust) and ambient (Atlanta, GA) fine particles (PM2.5). Chemical properties (speciation and mixing state) of iron-containing particles were characterized using X-ray absorption near edge structure (XANES) spectroscopy and micro-X-ray fluorescence measurements. Bulk iron solubility (soluble iron/total iron) of the samples was quantified by leaching experiments. Major differences were observed in iron solubility in source emission samples, ranging from low solubility (iron solubility did not correspond to silicon content or Fe(II) content. However, source emission and ambient samples with high iron solubility corresponded to the sulfur content observed in single particles. A similar correspondence between bulk iron solubility and bulk sulfate content in a series of Atlanta PM2.5 fine particle samples (N = 358) further supported this trend. In addition, results of linear combination fitting experiments show the presence of iron sulfates in several high iron solubility source emission and ambient PM2.5 samples. These results suggest that the sulfate content (related to the presence of iron sulfates and/or acid-processing mechanisms by H(2)SO(4)) of iron-containing particles is an important proxy for iron solubility.

  8. Effects of vine water status on dimethyl sulfur potential, ammonium, and amino acid contents in Grenache Noir grapes (Vitis vinifera).

    Science.gov (United States)

    De Royer Dupré, N; Schneider, R; Payan, J C; Salançon, E; Razungles, A

    2014-04-02

    We studied the effect of vine water status on the dimethyl sulfur potential (DMSP), ammonium, and amino acid contents of the berry during the maturation of Grenache Noir grapes. Water deficit increased the accumulation of amino acids in berries and favored yeast assimilable amino nitrogen. Similarly, ammonium content was higher in berries from vines subjected to moderate water deficit. DMSP content followed the same trend as yeast assimilable amino acid content, with higher concentrations observed in the berries of vines subjected to water deficit. The high DMSP and yeast assimilable nitrogen contents of musts from vines subjected to water deficit resulted in a better preservation of DMSP during winemaking. The wines produced from these musts had a higher DMSP level and would therefore probably have a higher aroma shelf life, because the DMSP determines the rate of release of dimethyl sulfur during wine storage, and this compound enhances fruity notes.

  9. Effects of mix ratio, moisture content and aeration rate on sulfur odor emissions during pig manure composting.

    Science.gov (United States)

    Zang, Bing; Li, Shuyan; Michel, Frederick; Li, Guoxue; Luo, Yuan; Zhang, Difang; Li, Yangyang

    2016-10-01

    Sulfur compounds in swine manure can cause odor emissions during composting if conditions are not conducive to their rapid oxidation and degradation. In this study, the effects of controllable composting process variables on sulfur odor emissions were investigated. These included pig manure to corn stalk mix ratio (0.7:1, 1.5:1 and 2.2:1dw basis), initial moisture content (60%, 65%, 70% and 75%) and aeration rate (1.0, 2.0, 3.0 and 4.0m(3)m(-3)h(-1)). The compounds measured were carbonyl sulfide, carbon disulfide, hydrogen sulfide, methyl mercaptan, ethyl mercaptan, diethyl sulfide, dimethyl sulfide (Me2S) and dimethyl disulfide (Me2SS). The results showed that total sulfur losses ranged from 3.9% to 18.3% after 26days of composting. Me2S and Me2SS were the primary (>59.61%) sulfur compounds released during this period. After turning, emission rates of both Me2S and Me2SS increased. Emissions of the other six sulfur compounds were low and inconsistent during composting. Within the compost, feedstock mix ratio significantly influenced the concentration of Me2SS, while aeration rate significantly affected Me2S concentration (pMoisture content did not have a significant effect on the concentrations of either of these two compounds. Concentrations of sulfur odor compounds were the lowest at the highest aeration rate. Therefore, high aeration rates during the thermophilic phase, especially after turning, are recommended to minimize sulfur odors produced during swine manure composting. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. 40 CFR 80.524 - What sulfur content standard applies to motor vehicle diesel fuel downstream of the refinery or...

    Science.gov (United States)

    2010-07-01

    ... to motor vehicle diesel fuel downstream of the refinery or importer? 80.524 Section 80.524 Protection... FUELS AND FUEL ADDITIVES Motor Vehicle Diesel Fuel; Nonroad, Locomotive, and Marine Diesel Fuel; and ECA Marine Fuel Motor Vehicle Diesel Fuel Standards and Requirements § 80.524 What sulfur content standard...

  11. Estimating the carbohydrate content of various forms of tobacco by phenol-sulfuric acid method.

    Science.gov (United States)

    Jain, Vardhaman Mulchand; Karibasappa, Gundabaktha Nagappa; Dodamani, Arun Suresh; Mali, Gaurao Vasant

    2017-01-01

    Due to consumption of various forms of tobacco in large amounts by Indian population, it has become a cause of concern for major oral diseases. In 2008, the WHO named tobacco as the world's single greatest cause of preventable death. It is also known that certain amount of carbohydrates are incorporated in processed tobacco to make it acceptable for consumption. Thus, its role in oral diseases becomes an important question at this point of time. Through this study, it is attempted to find out the carbohydrate content of various forms of tobacco by phenol-sulfuric acid method. Tobacco products selected for the study were Nandi hookah tambakhu (A), photo brand budhaa Punjabi snuff (B), Miraj (C), Gai-chhap tambakhu (D), Hanuman-chhap Pandharpuri tambakhu (E), and Hathi-chhap Bidi (F). The samples were decoded and transported to laboratory and tested at various concentrations by phenol-sulfuric acid method followed by ultraviolet spectrophotometry to determine their absorbance. The present study showed Hathi-chhap bidi/sample F had a maximum absorbance (1.995) at 10 μg/ml which is a smoking form of tobacco followed by rest all smokeless forms of tobacco, i.e. sample C (0.452), sample B (0.253), sample D (0.077), sample E (-0.018), and sample A (-0.127), respectively. As the concentration of tobacco sample increases, their absorbance increases which in turn is suggestive of increase in its carbohydrate concentration. Carbohydrates in the form of sugars, either inherently present or added in it during manufacturing can serve as a risk factor for higher incidence of dental caries.

  12. High sulfur content polymer nanoparticles obtained from interfacial polymerization of sodium polysulfide and 1,2,3-trichloropropane in water.

    Science.gov (United States)

    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. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Impacts of aviation fuel sulfur content on climate and human health

    Directory of Open Access Journals (Sweden)

    Z. Z. Kapadia

    2016-08-01

    Full Text Available Aviation emissions impact both air quality and climate. Using a coupled tropospheric chemistry-aerosol microphysics model we investigate the effects of varying aviation fuel sulfur content (FSC on premature mortality from long-term exposure to aviation-sourced PM2.5 (particulate matter with a dry diameter of  <  2.5 µm and on the global radiation budget due to changes in aerosol and tropospheric ozone. We estimate that present-day non-CO2 aviation emissions with a typical FSC of 600 ppm result in  ∼  3600 [95 % CI: 1310–5890] annual premature mortalities globally due to increases in cases of cardiopulmonary disease and lung cancer, resulting from increased surface PM2.5 concentrations. We quantify the global annual mean combined radiative effect (REcomb of non-CO2 aviation emissions as −13.3 mW m−2; from increases in aerosols (direct radiative effect and cloud albedo effect and tropospheric ozone. Ultra-low sulfur jet fuel (ULSJ; FSC  =  15 ppm has been proposed as an option to reduce the adverse health impacts of aviation-induced PM2.5. We calculate that swapping the global aviation fleet to ULSJ fuel would reduce the global aviation-induced mortality rate by  ∼  620 [95 % CI: 230–1020] mortalities a−1 and increase REcomb by +7.0 mW m−2. We explore the impact of varying aviation FSC between 0 and 6000 ppm. Increasing FSC increases aviation-induced mortality, while enhancing climate cooling through increasing the aerosol cloud albedo effect (CAE. We explore the relationship between the injection altitude of aviation emissions and the resulting climate and air quality impacts. Compared to the standard aviation emissions distribution, releasing aviation emissions at the ground increases global aviation-induced mortality and produces a net warming effect, primarily through a reduced CAE. Aviation emissions injected at the surface are 5 times less effective at forming cloud

  14. INFLUENCE OF ELEMENTAL SULFUR AND/OR INOCULATION WITH SULFUR OXIDIZING BACTERIA ON GROWTH, AND NUTRIENT CONTENT OF SORGHUM PLANTS GROWN ON DIFFERENT SOILS

    Directory of Open Access Journals (Sweden)

    Hala Kandil

    2011-12-01

    Full Text Available A pot experiment was conducted to study the effect of elemental sulfur(E.S rates (300 and 600 ppm and/or sulfur oxidizing bacteria (S.O.B. ATCC 8158 on growth and nutrients content of sorghum plants grown on different soils (sandy soils(I & II and clay loam soil.The obtained results could be summarized in the followings:Sorghum plants:Significant increases over the control were observed in fresh and dry weights of sorghum plant as well as its content of SO4=, N, P, K, Fe, Mn, Zn and Cu by using all the sulfur and/or the oxidizing bacteria treatments. Addition of E.S (300 & 600 ppm in combination with S.O.B. ATCC 8158 significantly increased both fresh and dry weights as well as SO4=, N, P, K, Fe, Mn, Zn and Cu contents of sorghum plants grown on the used soils as compared with either of them alone.E.S rates (300 & 600 ppm significantly increased the fresh and dry weights as well as all the studied nutrients content (SO4=, N, P, K, Fe, Mn, Zn and Cu of sorghum plants grown on the different soils as compared with S.O.B. ATCC 8158 treatment alone. The highest rate of E.S (600 ppm significantly increased all the previous parameters under study as compared with the lower rate (300 ppm. The highest values of fresh and dry weights as well as nutrients content (SO4=, N, P, K, Fe, Mn, Zn and Cu of sorghum plants grown on the used soils were obtained by 600 ppm E.S + S.O.B. ATCC 8158 treatment followed by 600 ppm E.S; 300 ppm E.S + S.O.B. ATCC 8158; 300 ppm E.S; S.O.B. ATCC 8158 and control treatments in decreasing order.The used soils:E.S rates (300 & 600 ppm and/or S.O.B. ATCC 8158 decreased pH values of the used soils after 3, 6 and 9 weeks from sowing as compared with their corresponding control treatments. The values of pH of sand soil (I and clay loam soil slightly decreased by time i.e they decreased from 3 weeks to 9 weeks from plantation. E.S rates (300 & 600 ppm with or without inoculation the used soils with S.O.B. ATCC 8158 significantly

  15. Influence of the rate of filtration of a complexly alloyed nickel melt through a foam-ceramic filter on the sulfur impurity content in the metal

    Science.gov (United States)

    Sidorov, V. V.; Min, P. G.; Folomeikin, Yu. I.; Vadeev, V. E.

    2015-06-01

    The article discusses the possibility of additional refining of a complexly alloyed nickel melt from a sulfur impurity by decreasing the filtration rate during the passage of the melt through a foam-ceramic filter. The degree of sulfur removal from the melt is shown to depend on its content in the alloy and the melt filtration rate.

  16. Comparative Evaluation of Sulfur Compounds Contents and Antiobesity Properties of Allium hookeri Prepared by Different Drying Methods

    Directory of Open Access Journals (Sweden)

    Min Hye Yang

    2017-01-01

    Full Text Available Despite the nutritional and medicinal values of Allium hookeri, its unique flavor (onion or garlic taste and smell coming from sulfur containing compounds limits its usage as functional food. For comparative study, A. hookeri roots were prepared under two different drying conditions, namely, low-temperature drying that minimizes the volatilization of sulfur components and hot-air drying that minimizes the garlic odor and spicy taste of A. hookeri. In GC/MS olfactory system, the odorous chemicals and organosulfur compounds such as diallyl trisulfide, dimethyl trisulfide, and dipropyl trisulfide were significantly decreased in hot-air drying compared to low-temperature drying. The spiciness and saltiness taste were noticeably reduced, while sourness, sweetness, and umami taste were significantly increased in hot-air dried A. hookeri according to electronic tongue. Although the content of volatile sulfur components was present at lower level, the administration of hot-air dried A. hookeri extract (100 mg/kg p.o. apparently prevented the body weight gain and improved insulin resistance in C57BL/6J obese mice receiving high fat diet. Results suggested that the hot-air dried A. hookeri possessing better taste and odor might be available as functional crop and bioactive diet supplement for the prevention and/or treatment of obesity.

  17. Renal cortex taurine content regulates renal adaptive response to altered dietary intake of sulfur amino acids.

    OpenAIRE

    Chesney, R W; Gusowski, N; Dabbagh, S

    1985-01-01

    Rats fed a reduced sulfur amino acid diet (LTD) or a high-taurine diet (HTD) demonstrate a renal adaptive response. The LTD results in hypotaurinuria and enhanced brush border membrane vesicle (BBMV) accumulation of taurine. The HTD causes hypertaurinuria and reduced BBMV uptake. This adaptation may relate to changes in plasma or renal cortex taurine concentration. Rats were fed a normal-taurine diet (NTD), LTD, or HTD for 14 d or they underwent: (a) 3% beta-alanine for the last 8 d of each d...

  18. On the effects of gravity and sulfur content on the weld shape in horizontal narrow gap GTAW of stainless steels

    KAUST Repository

    Traidia, Abderrazak

    2013-07-01

    A simplified 2D axisymmetric model and a comprehensive 3D weld pool model, accounting for the free surface deformation and the filler metal addition, have been developed to investigate the factors that lead to asymmetric bead shapes in horizontal GTA welding of stainless steels. Buoyancy-induced flow and the sagging of the pool free surface, under the action of gravity, are found to be responsible for the weld asymmetry and the decrease in the weld penetration at the bottom sidewall. The numerical results clearly emphasized the beneficial role of the Marangoni shear stress in limiting the asymmetry of horizontal GTA welds. An additional experimental investigation showed that the asymmetry in the weld shape can be reduced when placing the lowest sulfur content component at the bottom side. © 2013 Elsevier B.V. All rights reserved.

  19. Induction of mutation for increased sulfur content in the CFI strain of yeast by gamma-irradiation

    International Nuclear Information System (INIS)

    Faustino, C.C.

    1977-08-01

    From all current source of protein concentration the food yeast offers the greatest potential for development. Yeast protein is a good source of lysine and has adeqouate acounts of other essential amino acids such as trytophan and threonine, however, it was found to be relatively poor in the sulfur-containing amino acids which limits its nutrient value. A lasting remedy is genetic modification of the microorganisms to produce protein with a better amino acid balance. Gamma radiation from Co-60 was tried in these experiments being reported to induce mutations in the new CFI strain. A way of screening for increased sulfur content was devised. These are; 1) Incorporation of (NH 4 ) 2 35 S0 4 into the yeast cells; 2) Autoradiography; and 3) Quantitative determination of S-incorporation in submerse cultures of yeasts by use of a liquid scintillation counter. About seven hundred individual colonies were carefully and meticulously autQradiographically screened for high-S0 4 incorporation. Based on the results of autoradiography, 7.8% (50 strains) of the whole population were considered high in 35 S0 4 incorporation. The 50 yeast strains selected by autoradiography to be high in S0 4 incorporation were analyzed with the use of a liquid scintillation counter. From the data gathered, 29 mutants were se--lected. The data from these 29 mutants are presented in tabulated form. Only yeast strains no. 1, 42, 44, 47, 4, 3, 49, 50, 2 and 39 appear to show any promise as putative high-S mutants

  20. Impact of the 1990 Hong Kong legislation for restriction on sulfur content in fuel.

    Science.gov (United States)

    Wong, Chit-Ming; Rabl, Ari; Thach, Thuan Q; Chau, Yuen Kwan; Chan, King Pan; Cowling, Benjamin J; Lai, Hak Kan; Lam, Tai Hing; McGhee, Sarah M; Anderson, H Ross; Hedley, Anthony J

    2012-08-01

    After the implementation of a regulation restricting sulfur to 0.5% by weight in fuel on July 1, 1990, in Hong Kong, sulfur dioxide (SO2*) levels fell by 45% on average and as much as 80% in the most polluted districts (Hedley et al. 2002). In addition, a reduction of respiratory symptoms and an improvement in bronchial hyperresponsiveness in children were observed (Peters et al. 1996; Wong et al. 1998). A recent time-series study (Hedley et al. 2002) found an immediate reduction in mortality during the cool season at six months after the intervention, followed by an increase in cool-season mortality in the second and third years, suggesting that the reduction in pollution was associated with a delay in mortality. Proportional changes in mortality trends between the 5-year periods before and after the intervention were measured as relative risks and used to assess gains in life expectancy using the life table method (Hedley et al. 2002). To further explore the relation between changes in pollution-related mortality before and after the intervention, our study had three objectives: (1) to evaluate the short-term effects on mortality of changes in the pollutant mix after the Hong Kong sulfur intervention, particularly with changes in the particulate matter (PM) chemical species; (2) to improve the methodology for assessment of the health impact in terms of changes in life expectancy using linear regression models; and (3) to develop an approach for analyzing changes in life expectancy from Poisson regression models. A fourth overarching objective was to determine the relation between short- and long-term benefits due to an improvement in air quality. For an assessment of the short-term effects on mortality due to changes in the pollutant mix, we developed Poisson regression Core Models with natural spline smoothers to control for long-term and seasonal confounding variations in the mortality counts and with covariates to adjust for temperature (T) and relative

  1. Conduction-type control of SnSx films prepared by the sol–gel method for different sulfur contents

    International Nuclear Information System (INIS)

    Huang, Chung-Cheng; Lin, Yow-Jon; Chuang, Cheng-Yu; Liu, Chia-Jyi; Yang, Yao-Wei

    2013-01-01

    Highlights: ► The effect of S content on the electrical property of the SnS x film was examined. ► For S-rich films, the probability of having formed Sn vacancies (V Sn ) should be high. ► Transformation from V Sn to V Sn 2- is accompanied by lattice relaxation. ► Transformation from Sn 2+ to Sn 4+ is an offset to lattice relaxation. ► A link between the conduction type and defects was established. -- Abstract: The effect of S content on the electrical property of the sol–gel SnS x films was examined. The observed conduction-type changes are related to the different ratios between the concentrations of Sn 4+ and Sn 2+ . The experimental identification confirms that n-type conversion is due to an increase in the atomic concentration ratio of Sn 4+ /(Sn 4+ + Sn 2+ ) in the S-rich film. The probability of having formed Sn vacancies (V Sn ) should be high under S-rich growth conditions. Transformation from V Sn to V Sn 2- is accompanied by lattice relaxation. Therefore, transformation from Sn 2+ to Sn 4+ is an offset to lattice relaxation under S-rich growth conditions, increasing the electron density and producing n-type conversion. A suitable sulfur concentration is an important issue for tuning conduction type of SnS x

  2. Determining the water cut and water salinity in an oil-water flowstream by measuring the sulfur content of the produced oil

    International Nuclear Information System (INIS)

    Smith, H.D.; Arnold, D.M.

    1980-01-01

    A technique for detecting water cut and water salinity in an oil/water flowstream in petroleum refining and producing operations is described. The fluid is bombarded with fast neutrons which are slowed down and then captured producing gamma spectra characteristic of the fluid material. Analysis of the spectra indicates the relative presence of the elements sulfur, hydrogen and chlorine and from the sulfur measurement, the oil cut (fractional oil content) of the fluid is determined, enabling the water cut to be found. From the water cut, water salinity can also be determined. (U.K.)

  3. Urbanization impact on sulfur content of groundwater revealed by the study of urban speleothem-like deposits: Case study in Paris, France.

    Science.gov (United States)

    Pons-Branchu, E; Roy-Barman, M; Jean-Soro, L; Guillerme, A; Branchu, P; Fernandez, M; Dumont, E; Douville, E; Michelot, J L; Phillips, A M

    2017-02-01

    Speleothem-like deposits that develop underground in urban areas are an archive of the environmental impact of anthropic activities that has been little studied so far. In this paper, the sulfate content in shallow groundwater from northern Paris (France) is compared with the sulfur content in two 300-year-old urban carbonate deposits that grew in a historical underground aqueduct. The present-day waters of the aqueduct have very high sulfur and calcium contents, suggesting pollution from gypsum dissolution. However, geological gypsum levels are located below the water table. Sulfur content was measured by micro-X-ray fluorescence in these very S-rich carbonate deposits (0.5 to 1% of S). A twofold S increase during the second half of the 1800s was found in both samples. These dates correspond to two major periods of urbanization above the site. We discus three possible S sources: anthropic sources (industries, fertilizers…), volcanic eruptions and input within the water through gypsum brought for urbanization above the studied site (backfill with quarry waste) since the middle of the 19th century. For the younger second half of the studied section, S input from gypsum brought during urbanization was confirmed by the study of isotopic sulfur composition (δ 34 S=+15.2‰ at the top). For the oldest part, several sulfur peaks could be related to early industrial activity in Paris, that caused high local air pollution, as reported in historical archives but also to historical gypsum extraction. This study provides information on the origin and timing of the very high SO 4 2- levels measured nowadays within the shallow groundwater, thus demonstrating the interest in using carbonate deposits in urban areas as a proxy for the history of urbanization or human activities and their impact on water bodies. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Effect of Operating Conditions on Sulfur and Metal Content of Basrah Crude Oil

    Directory of Open Access Journals (Sweden)

    Muzher M. Ibrahim

    2013-05-01

    Full Text Available       In the present work, Basrah crude oil, atmospheric distillate of 305-623 K boiling range, vacuum distillate of 623-823 K boiling range, and wide petroleum distillate of boiling range 305-823 K are hydrotreated in trickle bed reactor using Cobalt-Molybdenum alumina as a catalyst. Hydrotreating temperatures are 598-648K, 598-673K, 648-673K and 648K respectively while LHSV are 0.7-2 hr-1, 1 hr-1, 0.7-2 hr-1 respectively. The operating pressure  and H2/Oil ratio for all experiments are kept constant at 3 Mpa and 300 liter/liter.    The results show that Sulphur and metal content decreased with increasing temperature and decreasing LHSV.     Vacuum residue of boiling range above 823K is mixed with hydrotreated atmospheric distillate, vacuum distillate and with the hydrotreated wide petroleum distillate. The temperature for hydrotreating the mixed sample is 648K and LHSV is 1 hr-1. It was found that hydrotreating crude oil is the best choice since it gives the highest removal of sulphur, vanadium and cobalt removal.

  5. Integrating principal component analysis and vector quantization with support vector regression for sulfur content prediction in HDS process

    Directory of Open Access Journals (Sweden)

    Shokri Saeid

    2015-01-01

    Full Text Available An accurate prediction of sulfur content is very important for the proper operation and product quality control in hydrodesulfurization (HDS process. For this purpose, a reliable data- driven soft sensors utilizing Support Vector Regression (SVR was developed and the effects of integrating Vector Quantization (VQ with Principle Component Analysis (PCA were studied on the assessment of this soft sensor. First, in pre-processing step the PCA and VQ techniques were used to reduce dimensions of the original input datasets. Then, the compressed datasets were used as input variables for the SVR model. Experimental data from the HDS setup were employed to validate the proposed integrated model. The integration of VQ/PCA techniques with SVR model was able to increase the prediction accuracy of SVR. The obtained results show that integrated technique (VQ-SVR was better than (PCA-SVR in prediction accuracy. Also, VQ decreased the sum of the training and test time of SVR model in comparison with PCA. For further evaluation, the performance of VQ-SVR model was also compared to that of SVR. The obtained results indicated that VQ-SVR model delivered the best satisfactory predicting performance (AARE= 0.0668 and R2= 0.995 in comparison with investigated models.

  6. Microbiological assay method for sulfate by means of cultivation of Escherichia coli B(H). II. Determination of sulfur contents in orange leaves

    Energy Technology Data Exchange (ETDEWEB)

    Oba, H; Yamamoto, T; Iwamura, Y

    1975-01-01

    As one of the studies on the application of microbiological assay method for sulfate using E. coli B(H), determination of sulfur content in orange leaves was examined. Preparation of sample solution was as follows: dried orange leaves were subjected to combustion in the presence of Mg(NO/sub 3/)/sub 2/ x 6H/sub 2/O as an oxidizing agent at 800/sup 0/ for 1 hr. The residue was dissolved in 3 n HCl, neutralized with 3 n KOH, and the solution was passed through a column of Amberlite IR-120 (H/sup +/ form). The effluent was used for the microbiological assay, and the results obtained were as follows: (1) it was possible to determine sulfur content in orange leaves by microbiological assay method using Mg(NO/sub 3/)/sub 2/ x 6H/sub 2/O as an oxidizing agent; (2) this microbiological method gave small standard deviation (sigma = 3.8%) and accurate recovery (98.1-101.5%).; (3) this proposed microbiological method will make it possible to determine sulfur content in orange leaves with the amount of a sample less than that in the gravimetric method.

  7. Effect of Sowing Date and Sulfur on Yield, Oil Content and Grain Nitrogen of Safflower (Carthamus tinctorius L. in Autumn Cultivation

    Directory of Open Access Journals (Sweden)

    N Safara

    2016-12-01

    by Kjeltec Analyzer Unit device. Grain oil was measured by PORIM procedure and finally the oil yield was calculated by multiplying oil content and the grain yield. Data from the experiment was analyzed using SAS software and mean comparison was carried out using LSD test at the 5% of probability. Results and Discussion Planting dates significantly affected grain number per head, biological yield, oil yield, grain yield, heads per plant and grain nitrogen. Sulfur fertilizer had a significant effect on grain number per head, oil yield, grain yield, heads per plant and grain nitrogen. There was a significant interaction between planting date and sulfur on grain yield, number of heads in plant and grain oil percentage. The late planting date resulted in plants exposed to high temperature and resulted in decreased safflower yield and yield components. Based on the results, the highest grain yield 4012.66 kg.ha-1 obtained in planting date 21 December. Late planting dates reduced grain yield to 50.28 percent. It was concluded that 200 kg.ha-1 sulfur increased grain yield through increasing the grain number per head and the number of heads in plant. Delayed planting decreased growth period length and resulted in reduced yield and its components. But the application of sulfur fertilizer by increasing yield components can compensate the loss of yield. Sulfur is sub-structure of fatty acid metabolism enzymes in fatty acid and bond formation reactions for the production of oil and involved in fat acids. Planting date and sulfur application in appropriate form increased grain and oil yield. Shortening the growing season due to a delay in planting and plant distance from the right conditions for growth reduced the grain yield. These factors limited the plant grow in optimal conditions, disrupted synthesis of primary and secondary metabolites in plants and had a negative effect on seed oil percent. Conclusions Delay in planting date reduced, flowering, grain filling period

  8. Variation of sulfur content in Cu(In,Ga)(S,Se){sub 2} thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Knipper, Martin; Knecht, Robin; Riedel, Ingo; Parisi, Juergen [Energy and Semiconductor Research Laboratory, Department of Physics, University of Oldenburg (Germany)

    2011-07-01

    Chalcopyrite thin film solar cells made of the compound semiconductor Cu(In,Ga)(S,Se){sub 2} (CIGSSe) have a strong potential for achieving high efficiencies at low production costs. Volume production of CIGSSe-modules has already started to exploit their favorable attributes such as low cost processing and reasonable module efficiency. In this study we studied industrially produced CIGSSe modules obtained from rapid thermal processing (RTP) for sulfurization. In detail, we investigated the effect of sulfur offer and RTP temperature (500 C to 580 C) on the photoelectric characteristics of small-area solar cells cut from the modules. Current-voltage profiling under standard test conditions revealed a strong influence of the particular process recipe on the open circuit voltage whereas significant variations of the maximum quantum efficiency can be observed. X-ray diffraction was employed to relate these effects to the crystallographic structure of the actual CIGSSe films. Lock-in thermographic imaging was employed to link apparent film inhomogeneities and disruptions to the specific process recipe.

  9. Effect of aluminum content on the passivation behavior of Fe-Al alloys in sulfuric acid solution

    DEFF Research Database (Denmark)

    Chiang, Wen-Chi; Luu, W.C.; Wu, J.K.

    2006-01-01

    -Al alloys, which the Al content of alloy exceeds 19 at %, have wide passivation regions with low passivation current. However, when the Al content of Fe-Al alloys exceeds this range, the increment of Al content has slight influence on passivation behavior compared with ternary Cr addition....

  10. Quantitative hepatosplenic scintiscanning. Experimental and clinical studies to determine the contents of radioactivity in liver and spleen following administration of 99mTc sulfur colloid

    International Nuclear Information System (INIS)

    Feuchtinger, T.

    1983-01-01

    Hepatosplenic scintiscans were obtained from 78 patients following administration of 99mTc sulfur colloid using a double-head scanner and subjected to quantitative analysis. It was the aim of the study to assess the practicability of quantitative scintiscanning of liver and spleen, to define the range of generally acceptable, normal values for the concentration of 99mTc sulfur colloid in liver and spleen as well as to evaluate the clinical relevance of this method. The following values were determined to be normal: 4.7±1.5 for the liver: Spleen ratio; 31±3% for the proportion of the left hepatic lobe in total liver concentration; 68.7±5.4% and 17.4±3.6% for the active contents of liver and spleen, respectively. Quantitative scintiscanning constitutes a very sensitive method to detect transformation processes in the liver that are associated with a decreased liver: Spleen ratio and an increased ratio between the left hepatic lobe and the total organ. The method is unsuitable to assess pathological accumulation of the tracer substances. The question as to whether the use of the more time-consuming procedure of quantitative scintiscanning is justified by the additional diagnostic information gained remains to be investigated in further studies. (TRV) [de

  11. Diesel with low sulfur content and high cetane number produced by two stages hydrotreating procedures; Diesel com baixos teores de enxofre e alto numero de cetano a partir de hidrotratamento em dois estagios

    Energy Technology Data Exchange (ETDEWEB)

    Zotin, J L; Pacheco, M E; Souza, V P; Belato, D; Silva, R M.S. [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2004-07-01

    According to the Brazilian specifications for diesel, lower sulfur content and higher cetane number can be expected in the near future, leading to an increased capacity of hydrotreating processes. PETROBRAS has proved technology for hydrotreating processes with 8 high pressure single stage units in operation. However, the production of ultra low sulfur diesel with high cetane number may require two stages processes, with conventional hydrotreating in the first step and deep aromatic saturation (HDA), with increase in the cetane number, in the second one. In this approach, noble metal catalysts, which are more active for hydrogenation but more sensitive to sulfur and nitrogen poisoning, can be used in the second stage. In the present work, the 2 stages approach was studied for maximizing cetane number of Brazilian gasoils. The influence of operating variables and the inhibition effect by sulfur and nitrogen were analyzed. Diesel with sulfur content below 10 ppm and high aromatic conversions at relatively mild conditions were obtained with noble metal catalysts, with a cetane number increase up to 6 points in the second stage. Sulfur compounds have a stronger inhibition effect than basic nitrogen compounds on hydrogenation reaction rates, but a synergetic effect was observed when both contaminants were present in high concentrations. (author)

  12. Air Quality Criteria for Sulfur Oxides.

    Science.gov (United States)

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

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

  13. Variation of the active sulfur and its leave content in the adult African palm in the piedemonte soils of the Colombian eastern plains, during two climatic periods

    International Nuclear Information System (INIS)

    Davila, Gustavo A; Guerrero R; Rojas L A

    2000-01-01

    Investigations carried out until the present in Colombia on critical levels of sulfur in soils and its concentration in plant tissues of the oil palm is very scarce. Therefore, critical levels in soils obtained for other crops in Colombia and investigations about S content in oil palm accomplished in other countries, had been taken into account in order to have an idea of the nutritional S status in the Colombian oil palm crops. The present work had as an objective to measure the concentration of S in the tissue of the 17th leaf of adult oil palms (7-9 years) and the content of the active element in soil (by using the 0.008 m. monocalcic phosphate method) in two climatic periods (wet-dry) on soils (oxisols and inceptisols) of 12 plantations of the western Colombian plains. The evaluated soils were S deficient (< 5 ppm), with the exception of three plantations (Palmeta, Palmallano and Palmar of Manavire) at the first sampling depth (0-30 cm) during the two climatic periods evaluated. The greatest accumulation of S was found in the second sampling depth (30-60 cm). The leave concentration of S in most of the plantations was lower than the critical levels (0,20-0,23%) reported by other investigators (Malavolta, 1994; Hagstron (1988) y Ollagnier et al (1970), cited by Owen (1991), and Von Euxkull, 1996), during the two climatic periods of sampling, with no correlation to the values found in soils. the previous permits to deduce that: a) the concentrations of S in leave tissues for adult oil palm were less than the reported values in other countries. b) The critical levels for S in the soils tend to be in general, lower than those established in Colombia for other crops. C) The fertilization levels with S, tend be insufficient to satisfy the demand of the element in the evaluated plantations d) It is considered necessary to evaluate the efficiency of other methodologies to evaluate the S content in the plant as well as in the soil

  14. Effect of sulfur content in wet or dry distillers grains fed at several inclusions on cattle growth performance, ruminal parameters, and hydrogen sulfide.

    Science.gov (United States)

    Sarturi, J O; Erickson, G E; Klopfenstein, T J; Vasconcelos, J T; Griffin, W A; Rolfe, K M; Benton, J R; Bremer, V R

    2013-10-01

    Effects of S from wet or dry distillers grains with solubles (DGS) containing 0.82 or 1.16% S on animal growth performance, carcass characteristics, apparent total tract digestibility, and ruminal parameters were evaluated. In Exp. 1, crossbred beef steers (n = 120; 345 ± 34 kg BW) were individually fed ad libitum using Calan gates. Treatments were applied as a 2 × 2 × 3 + 1 factorial treatment arrangement with factors of DGS type (wet or dry), S content in DGS (0.82 or 1.16% DM basis), and DGS inclusion (20, 30, and 40%, DM basis), as well as a corn control diet (no DGS). In Exp. 2, ruminally cannulated crossbred beef steers (n = 6; 381 ± 31 kg BW) were assigned to 1 of 5 diets in a 5 × 6 unbalanced Latin Square design and fed ad libitum through five 14-d periods. A 2 × 2 + 1 factorial treatment arrangement was used with the factors of DGS type and S content in DGS (similar to Exp. 1). Inclusion of DGS was 40%, except for a MATCH diet containing wet 1.16% S DGS included at 31.4% (DM basis). Intake of DM decreased linearly (P content (P = 0.52). Feeding diets with wet 1.16% S DGS linearly decreased (P = 0.03) HCW. In Exp. 2, molar proportion of propionate declined (P = 0.01) 9% and A:P ratio tended (P = 0.13) to be greater when 1.16 compared with 0.82% S DGS was fed. Apparent total tract DMD was not affected (P > 0.16) and only subtle changes (P ruminal pH parameters were observed. Greater (P = 0.02) ruminal H2S concentration for steers fed wet compared with dry DGS was observed, while 1.16% S DGS tended (P = 0.12) to produce greater ruminal H2S than 0.82% S. Sulfur in wet DGS appears to be more prone to be converted to ruminal H2S, because feeding 1.16% S as wet DGS had a greater impact on ADG, DMI, and ruminal H2S compared with dry DGS.

  15. Sulfur cycle

    Digital Repository Service at National Institute of Oceanography (India)

    LokaBharathi, P.A.

    Microbes, especially bacteria, play an important role in oxidative and reductive cycle of sulfur. The oxidative part of the cycle is mediated by photosynthetic bacteria in the presence of light energy and chemosynthetic forms in the absence of light...

  16. Sulfur Mustard

    Science.gov (United States)

    ... in of the vapors can cause chronic respiratory disease, repeated respiratory infections, or death. Extensive eye exposure can cause permanent blindness. Exposure to sulfur mustard may increase a person’s risk for lung and respiratory cancer. ...

  17. Sulfur problems in Swedish agriculture

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, O

    1959-01-01

    The present paper deals with some aspects of the sulfur situation in Swedish agriculture with special emphasis on the importance of and relationships among various sources of sulfur supply. An inventory of the sulfur content of Swedish soils and hay crops includes 649 soil samples and a corresponding number of hay samples from 59 locations. In a special investigation the samples were found to be representative of normal Swedish farm land. It is concluded that the amount of sulfur compounds in the air is the primary factor which determines the amount of sulfur added to the soil from the atmosphere. Compared with values obtained in other countries, the amount of sulfur added by the precipitation in Sweden is very low. The distribution in air and precipitation of sulfur from an industrial source was studied in a special investigation. An initial reason for the present study was the damage to vegetation caused by smoke from an industrial source. It was concluded that the average conditions in the vicinity of the industrial source with respect to smoke constituents in the air and precipitation were unfavorable only to the plants directly within a very narrow region. Relationships among the sulfur contents of air, of precipitation, of soils and of plants have been subject to special investigations. In the final general discussion and conclusions it is pointed out that the results from these investigations indicate evident differences in the sulfur status of Swedish soils. The present trend toward the use of more highly concentrated fertilizers poor in sulfur may be expected to cause a considerable change in the sulfur situation in Swedish agriculture. 167 references, 40 figures, 44 tables.

  18. In-situ studies on volatile jet exhaust particle emissions - impacts of fuel sulfur content and environmental conditions on nuclei-mode aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, F.; Baumann, R.; Petzold, A.; Busen, R.; Schulte, P.; Fiebig, M. [DLR Deutsches Zentrum fuer Luft- und Raumfahrt e.V., Wessling (Germany). Inst. fuer Physik der Atmosphaere; Brock, C.A. [Denver Univ., CO (United States). Dept. of Engineering

    2000-02-01

    In-situ measurements of ultrafine aerosol particle emissions were performed at cruise altitudes behind the DLR ATTAS research jet (RR M45H M501 engines) and a B737-300 aircraft (CFM56-3B1 engines). Measurements were made 0.15-20 seconds after emission as the source aircraft burned fuel with sulfur contents (FSC) of 2.6, 56 or 118 mg kg{sup -1}. Particle size distributions of from 3 to 60 nm diameter were determined using CN-counters with varying lower size detection limits. Volatile particle concentrations in the aircraft plumes strongly increased as diameter decreased toward the sizes of large molecular clusters, illustrating that apparent particle emissions are extremely sensitive to the smallest particle size detectable by the instrument used. Environmental conditions and plume age alone could influence the number of detected ultrafine (volatile) aerosols within an order of magnitude, as well. The observed volatile particle emissions decreased nonlinearly as FSC decreased to 60 mg kg{sup -1}, reaching minimum values of about 2 x 10{sup 17} kg{sup -1} and 2 x 10{sup 16} kg{sup -1} for particles >3 nm and >5 nm, respectively. Volatile particle emissions did not change significantly as FSCs were further reduced below 60 mg kg{sup -1}. Volatile particle emissions did not differ significantly between the two studied engine types. In contrast, soot particle emissions from the modern CFM56-3B1 engines were 4-5 times less (4 x 10{sup 14} kg{sup -1}) than from the older RR M45H M501 engines (1.8 x 10{sup 15} kg{sup -1}). Contrail processing has been identified as an efficient sink/quenching parameter for ultrafine particles and reduces the remaining interstitial aerosol by factors 2-10 depending on particle size.

  19. Degradation of self-compacting concrete (SCC) due to sulfuric acid attack: Experiment investigation on the effect of high volume fly ash content

    Science.gov (United States)

    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.

  20. Sulfur Earth

    Science.gov (United States)

    de Jong, B. H.

    2007-12-01

    Variations in surface tension affect the buoyancy of objects floating in a liquid. Thus an object floating in water will sink deeper in the presence of dishwater fluid. This is a very minor but measurable effect. It causes for instance ducks to drown in aqueous solutions with added surfactant. The surface tension of liquid iron is very strongly affected by the presence of sulfur which acts as a surfactant in this system varying between 1.9 and 0.4 N/m at 10 mass percent Sulfur (Lee & Morita (2002), This last value is inferred to be the maximum value for Sulfur inferred to be present in the liquid outer core. Venting of Sulfur from the liquid core manifests itself on the Earth surface by the 105 to 106 ton of sulfur vented into the atmosphere annually (Wedepohl, 1984). Inspection of surface Sulfur emission indicates that venting is non-homogeneously distributed over the Earth's surface. The implication of such large variation in surface tension in the liquid outer core are that at locally low Sulfur concentration, the liquid outer core does not wet the predominantly MgSiO3 matrix with which it is in contact. However at a local high in Sulfur, the liquid outer core wets this matrix which in the fluid state has a surface tension of 0.4 N/m (Bansal & Doremus, 1986), couples with it, and causes it to sink. This differential and diapiric movement is transmitted through the essentially brittle mantle (1024 Pa.s, Lambeck & Johnson, 1998; the maximum value for ice being about 1030 Pa.s at 0 K, in all likely hood representing an upper bound of viscosity for all materials) and manifests itself on the surface by the roughly 20 km differentiation, about 0.1 % of the total mantle thickness, between topographical heights and lows with concomitant lateral movement in the crust and upper mantle resulting in thin skin tectonics. The brittle nature of the medium though which this movement is transmitted suggests that the extremes in topography of the D" layer are similar in range to

  1. Content

    DEFF Research Database (Denmark)

    Keiding, Tina Bering

    secondary levels. In subject matter didactics, the question of content is more developed, but it is still mostly confined to teaching on lower levels. As for higher education didactics, discussions on selection of content are almost non-existent on the programmatic level. Nevertheless, teachers are forced...... curriculum, in higher education, and to generate analytical categories and criteria for selection of content, which can be used for systematic didactical reflection. The larger project also concerns reflection on and clarification of the concept of content, including the relation between content at the level......Aim, content and methods are fundamental categories of both theoretical and practical general didactics. A quick glance in recent pedagogical literature on higher education, however, reveals a strong preoccupation with methods, i.e. how teaching should be organized socially (Biggs & Tang, 2007...

  2. Effect of sulfur dioxide on proteins of the vegetable organism

    Energy Technology Data Exchange (ETDEWEB)

    Reckendorfer, P; Beran, F

    1931-01-01

    Experiments were performed to determine the effects of sulfur dioxide on red clover in a controlled environment. An increase in the concentration of sulfur dioxide caused a significant decrease in the digestible protein. However, after the sulfur dioxide was discontinued, there was a decrease in the indigestible protein. The leaves showed an increase in spotting with an increase in sulfur dioxide concentration. Chemical analysis of the soil revealed a higher sulfur content in these experiments.

  3. Annotated bibliography of methods for determining sulfur and forms of sulfur in coal and coal-related materials

    Energy Technology Data Exchange (ETDEWEB)

    Chriswell, C.D.; Norton, G.A.; Akhtar, S.S.; Straszheim, W.E.; Markuszewski, R.

    1993-01-01

    Over 400 published papers, presentations at scientific meetings, and reports relating to the determination of sulfur and sulfur forms in coal-related materials have been accumulated, classified, and an evaluation made of their content.

  4. Biochemistry of the normal dura mater of the human brain determination of water, sodium, potassium, calcium, phosphorus, magnesium, copper, iron, sulfur and nitrogen contents

    Directory of Open Access Journals (Sweden)

    Horacio M. Canelas

    1969-06-01

    Full Text Available The concentrations of water, sodium, potassium, calcium, phosphorus, magnesium, copper, iron, sulfur, and nitrogen were determined in samples of apparently normal dura mater removed from 18 subjects recently dead by craniocerebral trauma. The average concentrations expressed in dry weight were: water 79.55 g/100 g ± 2.52; sodium 1.63 mequiv/100 g ±0.27; potassium 3.68 mequiv/100 g ± 0.66; calcium 119.84 mg/100 g ± 107.40; phosphorus 68.2 mg/100 g ± 34.5; magnesium 0.61 mequiv/100 g ± 0.37; copper 249.8 /xg/100 g ± 109.4; iron 0.82 mg/100 g ± 0.28; sulfur 490.7 mg/100 g ± 22.5; nitrogen 3.33 g/100 g ± 0.17.

  5. Effect of different sulfur levels from various sources on brassica napus growth and soil sulfur fractions

    International Nuclear Information System (INIS)

    Khalid, R.; Khan, K.S.; Islam, M.; Yousaf, M.; Shabbir, G.

    2012-01-01

    A two year field study was conducted at two different locations in northern rain fed Punjab, Pakistan to assess the effect of different rates of sulfur application from various sources on soil sulfur fractions and growth of Brassica napus. The treatments included three sulfur sources i. e., single super phosphate, ammonium sulfate and gypsum each applied at five different rates (0, 10, 20, 30 and 40 kg S ha/sup -1/ ). Sulfur application had a significant positive effect on the growth and yield parameters of Brassica napus. Among the sulfur sources ammonium sulfate resulted in maximum increase in plant growth and yield parameters, followed by single super phosphate. Sulfur content and uptake by crop plants was significantly higher with ammonium sulfate application as compared to other two sulfur sources. Sulfur application also exerted a significant positive effect on different S fractions in the soils. On an average, 18.0% of the applied sulfur got incorporated into CaCl/sub 2/ extractable sulfur fraction, while 15.6% and 35.5% entered into adsorbed and organic sulfur fractions in the soils, respectively. The value cost ratio increased significantly by sulfur application up to 30 kg ha/sup -1/. Among sulfur sources, ammonium sulfate performed best giving the highest net return. (author)

  6. Biologically produced sulfur

    NARCIS (Netherlands)

    Kleinjan, W.E.; Keizer, de A.; Janssen, A.J.H.

    2003-01-01

    Sulfur compound oxidizing bacteria produce sulfur as an intermediate in the oxidation of hydrogen sulfide to sulfate. Sulfur produced by these microorganisms can be stored in sulfur globules, located either inside or outside the cell. Excreted sulfur globules are colloidal particles which are

  7. Results of determinations of the sulfur-dioxide content of the atmospheric air with a portable measurement kit based on the pararosaniline method

    Energy Technology Data Exchange (ETDEWEB)

    Lampadius, F

    1963-01-01

    Among the toxides emitted by industry, home heating, and transportation and which are polluting the atmospheric air, sulfur dioxide occupies the forefront of our interest in any examination of smoke damage to agricultural and forest growth. This primary position is based on the high degree of the sensitivity of plants to sulfur dioxide. The SO/sub 2/ toxicity threshold, for example, for spruce trees is between 0.4 and 0.5 mg/m/sup 3/. In contrast, an irritant concentration threshold for the nervous system of man has been set at 0.6 mg SO/sub 2//m/sup 3/. Studies have demonstrated that the SO/sub 2/ damage to plants - aside from the plant's stage of development - can be attributed to the product of the concentration and the duration of the toxide's action. The air-analytical proof of the sulfur dioxide as the cause for plant smoke damage must extend then to the selective recording of the SO/sub 2/ admixture in the atmospheric air, to the determination of the SO/sub 2/ level of the air in mg/m/sup 3/ within a longer period of time, and finally through short-term measurements to the discovery of when and how long peak concentrations of phytoxic SO/sub 2/ occur. In keeping with this goal, an SO/sub 2/ device was developed and used to conduct, on several occasions in the course of 1962, air examinations in individual smoke-damaged areas of the German Democratic Republic. The results of these air measurements are treated in this paper. 7 figures, 2 tables.

  8. Comparative Genomics of Green Sulfur Bacteria

    DEFF Research Database (Denmark)

    Ussery, David; Davenport, C; Tümmler, B

    2010-01-01

    Eleven completely sequenced Chlorobi genomes were compared in oligonucleotide usage, gene contents, and synteny. The green sulfur bacteria (GSB) are equipped with a core genome that sustains their anoxygenic phototrophic lifestyle by photosynthesis, sulfur oxidation, and CO(2) fixation. Whole...... weight of 10(6), and are probably instrumental for the bacteria to generate their own intimate (micro)environment....

  9. Sulfur metabolism in phototrophic sulfur bacteria

    DEFF Research Database (Denmark)

    Frigaard, Niels-Ulrik; Dahl, Christiane

    2008-01-01

    Phototrophic sulfur bacteria are characterized by oxidizing various inorganic sulfur compounds for use as electron donors in carbon dioxide fixation during anoxygenic photosynthetic growth. These bacteria are divided into the purple sulfur bacteria (PSB) and the green sulfur bacteria (GSB......). They utilize various combinations of sulfide, elemental sulfur, and thiosulfate and sometimes also ferrous iron and hydrogen as electron donors. This review focuses on the dissimilatory and assimilatory metabolism of inorganic sulfur compounds in these bacteria and also briefly discusses these metabolisms...... in other types of anoxygenic phototrophic bacteria. The biochemistry and genetics of sulfur compound oxidation in PSB and GSB are described in detail. A variety of enzymes catalyzing sulfur oxidation reactions have been isolated from GSB and PSB (especially Allochromatium vinosum, a representative...

  10. Sulfur Removal by Adding Iron During the Digestion Process of High-sulfur Bauxite

    Science.gov (United States)

    Zhanwei, Liu; Hengwei, Yan; Wenhui, Ma; Keqiang, Xie; Dunyong, Li; Licong, Zheng; Pengfei, Li

    2018-04-01

    This paper proposes a novel approach to sulfur removal by adding iron during the digestion process. Iron can react with high-valence sulfur (S2O3 2-, SO3 2-, SO4 2-) to generate S2- at digestion temperature, and then S2- enter red mud in the form of Na3FeS3 to be removed. As iron dosage increases, high-valence sulfur concentration decreases, but the concentration of S2- increases; sulfur digestion rate decreases while sulfur content in red mud markedly increases; the alumina digestion rate, conversely, remains fairly stable. So sulfur can be removed completely by adding iron in digestion process, which provide a theoretical basis for the effective removal of sulfur in alumina production process.

  11. Sulfur removal from low-sulfur gasoline and diesel fuel by metal-organic frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Hagen, G.; Haemmerle, M.; Moos, R. [Functional Materials, University of Bayreuth, Bayreuth (Germany); Malkowsky, I.M.; Kiener, C. [BASF SE, Ludwigshafen (Germany); Achmann, S.

    2010-02-15

    Several materials in the class of metal-organic frameworks (MOF) were investigated to determine their sorption characteristics for sulfur compounds from fuels. The materials were tested using different model oils and common fuels such as low-sulfur gasoline or diesel fuel at room temperature and ambient pressure. Thiophene and tetrahydrothiophene (THT) were chosen as model substances. Total-sulfur concentrations in the model oils ranged from 30 mg/kg (S from thiophene) to 9 mg/kg (S from tetrahydrothiophene) as determined by elementary analysis. Initial sulfur contents of 8 mg/kg and 10 mg/kg were identified for low-sulfur gasoline and for diesel fuel, respectively, by analysis of the common liquid fuels. Most of the MOF materials examined were not suitable for use as sulfur adsorbers. However, a high efficiency for sulfur removal from fuels and model oils was noticed for a special copper-containing MOF (copper benzene-1,3,5-tricarboxylate, Cu-BTC-MOF). By use of this material, 78 wt % of the sulfur content was removed from thiophene containing model oils and an even higher decrease of up to 86 wt % was obtained for THT-based model oils. Moreover, the sulfur content of low-sulfur gasoline was reduced to 6.5 mg/kg, which represented a decrease of more than 22 %. The sulfur level in diesel fuel was reduced by an extent of 13 wt %. Time-resolved measurements demonstrated that the sulfur-sorption mainly occurs in the first 60 min after contact with the adsorbent, so that the total time span of the desulfurization process can be limited to 1 h. Therefore, this material seems to be highly suitable for sulfur reduction in commercial fuels in order to meet regulatory requirements and demands for automotive exhaust catalysis-systems or exhaust gas sensors. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  12. Contents

    Directory of Open Access Journals (Sweden)

    Editor IJRED

    2012-11-01

    Full Text Available International Journal of Renewable Energy Development www.ijred.com Volume 1             Number 3            October 2012                ISSN 2252- 4940   CONTENTS OF ARTICLES page Design and Economic Analysis of a Photovoltaic System: A Case Study 65-73 C.O.C. Oko , E.O. Diemuodeke, N.F. Omunakwe, and E. Nnamdi     Development of Formaldehyde Adsorption using Modified Activated Carbon – A Review 75-80 W.D.P Rengga , M. Sudibandriyo and M. Nasikin     Process Optimization for Ethyl Ester Production in Fixed Bed Reactor Using Calcium Oxide Impregnated Palm Shell Activated Carbon (CaO/PSAC 81-86 A. Buasri , B. Ksapabutr, M. Panapoy and N. Chaiyut     Wind Resource Assessment in Abadan Airport in Iran 87-97 Mojtaba Nedaei       The Energy Processing by Power Electronics and its Impact on Power Quality 99-105 J. E. Rocha and B. W. D. C. Sanchez       First Aspect of Conventional Power System Assessment for High Wind Power Plants Penetration 107-113 A. Merzic , M. Music, and M. Rascic   Experimental Study on the Production of Karanja Oil Methyl Ester and Its Effect on Diesel Engine 115-122 N. Shrivastava,  , S.N. Varma and M. Pandey  

  13. Impact of sulfur content on structural and optical properties of Ge20Se80-xSx chalcogenide glasses thin films

    Science.gov (United States)

    Dongol, M.; Elhady, A. F.; Ebied, M. S.; Abuelwafa, A. A.

    2018-04-01

    Chalcogenide system Ge20Se80-xSx (x = 0, 15 and 30%) thin films were prepared by thermal evaporation technique. The amorphous state of the samples was confirmed according to XRD. The structural changes occurring upon replacement Se by S was investigated using Raman spectroscopy. The optical properties of the as-deposited Ge20Se80-xSx thin films have been studied by analysis the transmittance T(λ) measured at room temperature in the wavelength range 200-2500 nm using Swanepoel's method. Urbach energy (Ee) and optical band gap (Eg) were strongly affected by sulfur concentration in the sample. The refractive index evaluated through envelope method was extrapolated by Cauchy dispersion relationship over the whole spectral range. Moreover, the dispersion of refractive index was analyzed in terms of the single-oscillator Wemple-Di Domenico model. The third-order nonlinear susceptibility (χ(3)) and nonlinear refractive index (n2) were calculated and discussed for different Ge20Se80-xSx (x = 0, 15 and 30%).

  14. The effects of copper fining on the wine content in sulfur off-odors and on their evolution during accelerated anoxic storage.

    Science.gov (United States)

    Vela, Eduardo; Hernández-Orte, Purificación; Franco-Luesma, Ernesto; Ferreira, Vicente

    2017-09-15

    Three different red wines with reductive character have been treated with two different doses of copper sulfate (0.06 and 0.5mg/L) and with a commercial copper-containing product at the recommended dose (0.6mg/L). Wines were in contact with copper one week, centrifuged and stored at 50°C in strict anoxia for 2weeks (up to 7 in one case). Brine-releasable (BR-) and free fractions of Volatile Sulfur Compounds were determined throughout the process. Relevant increases of BR-H 2 S suggest that those wines contained other H 2 S precursors non-detectable by the brine dilution method. Copper treatments had two major effects: 1) immediate decrease the levels of free H 2 S and methanethiol (MeSH); 2) slow the rate at which free H 2 S (not MeSH) increases during anoxic storage. After 7weeks of anoxia levels of free H 2 S and MeSH were high and similar regardless of the copper treatment. Higher copper doses could induce the accumulation of BR-H 2 S. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Sulfur-Kβ /sub emission studies on sulfur-bearing heterocycles

    International Nuclear Information System (INIS)

    Phillips, D.R.; Andermann, G.G.; Fujiwara, F.

    1986-01-01

    Sulfur-K/β /sub x-ray fluorescence spectroscopy (XFS) has been used to study the electronic structure and bonding in sulfur-bearing heterocycles. XFS not only has the capability of experimentally measuring valence electron energies in molecular species, but can also provide intensity data which can help define the nature of the molecular orbitals defined by the electrons. This report discusses the feasibility of using XFS as an analytical tool for the determination of total and specific sulfur heterocycle content in samples. A variety of compounds were studied. These include thiophene, thiophene derivatives, tetranydrothiophene, several more complex saturated and unsaturated sulfur heterocycles, and heterocycles containing both sulfur and nitrogen. The sulfur-K/β /sub spectra were obtained using a double crystal spectrometer which provided an instrumental resolution of about 0.7 eV

  16. Effects of sulfur dioxide on vegetation

    Energy Technology Data Exchange (ETDEWEB)

    Whitby, G S

    1939-11-11

    A discussion is presented on the effects of sulfur dioxide on vegetation as observed at Trail, British Columbia. The investigation was carried out over a period of eight years, 1929 to 1937. The concentration of sulfur dioxide at the United States border was carefully determined throughout the crop season at a point 16 miles from the source of sulfur dioxide. Maximum and average concentrations in part per million are given. The sulfur content of vegetation was determined and was found to diminish as the distance from the smelter increased. It was determined that the sulfur content may rise to four times the normal amount without injurious effect. This is particularly so with prolonged low concentration. The effect on the soil was determined by measuring soluble sulfate, pH and exchangeable bases. The soil near the plant was affected, but this fell off rapidly with increase in distance so that eight miles from the smelter the soil was substantially normal. No effect on water supplies was found. An appreciable retardation in growth, as determined by annular rings, was noted for trees exposed to the sulfur dioxide. This effect was lost following installation of sulfur dioxide control at Trail. Conifers were found more susceptible during periods of active growth than when dormant. Also, transplanted conifers were more severly affected than native trees. Seedlings were less resistant that older trees.

  17. Sulfur poisoning in cattle

    Energy Technology Data Exchange (ETDEWEB)

    Julian, R J; Harrison, K B

    1975-01-01

    A case of sulfur poisoning is described in which 12 of 20 cattle died following the feeding of sulfur. Respiratory distress and abdominal pain were the prominent signs. Examination of one animal revealed vasculitis and necrosis of the rumen and abomasal wall. The possible toxic effects of sulfur are discussed.

  18. Plutonium oxides analysis. Sulfur potentiometric analysis

    International Nuclear Information System (INIS)

    Anon.

    Total sulfur determination (sulfur, sulfates, sulfides ...) in plutonium oxides, suitable for sulfate ion content between 0.003 percent to 0.2 percent, by dissolution in nitric hydrofluoric acid, nitrates elimination, addition of hydrochloric acid and reduction in hydrogen sulfide which is carried by an inert gas and neutralized by sodium hydroxide. Sodium sulfide is titrated with mercuric acetate by constant intensity potentiometry [fr

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

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ya; Guo, Jinxin; Zhang, Jun, E-mail: zhangjun@zjnu.cn; Su, Qingmei; Du, Gaohui, E-mail: gaohuidu@zjnu.edu.cn

    2015-01-01

    Graphical abstract: - Highlights: • A graphene-wrapped sulfur nanospheres composite with 91 wt% S is prepared. • It shows highly improved electrochemical performance as cathode for Li–S cell. • The PVP coating and conductive graphene minimize polysulfides dissolution. • The flexible coatings with void space accommodate the volume expansion of sulfur. - Abstract: 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{sup −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.

  20. Sulfur-Containing Agrochemicals.

    Science.gov (United States)

    Devendar, Ponnam; Yang, Guang-Fu

    2017-10-09

    Modern agricultural chemistry has to support farmers by providing innovative agrochemicals. In this context, the introduction of sulfur atoms into an active ingredient is still an important tool in modulating the properties of new crop-protection compounds. More than 30% of today's agrochemicals contain at least one sulfur atom, mainly in fungicides, herbicides and insecticides. A number of recently developed sulfur-containing agrochemical candidates represent a novel class of chemical compounds with new modes of action, so we intend to highlight the emerging interest in commercially active sulfur-containing compounds. This chapter gives a comprehensive overview of selected leading sulfur-containing pesticidal chemical families namely: sulfonylureas, sulfonamides, sulfur-containing heterocyclics, thioureas, sulfides, sulfones, sulfoxides and sulfoximines. Also, the most suitable large-scale synthetic methods of the recently launched or provisionally approved sulfur-containing agrochemicals from respective chemical families have been highlighted.

  1. New high pressure experiments on sulfide saturation of high-FeO∗ basalts with variable TiO2 contents - Implications for the sulfur inventory of the lunar interior

    Science.gov (United States)

    Ding, Shuo; Hough, Taylor; Dasgupta, Rajdeep

    2018-02-01

    In order to constrain sulfur concentration in intermediate to high-Ti mare basalts at sulfide saturation (SCSS), we experimentally equilibrated FeS melt and basaltic melt using a piston cylinder at 1.0-2.5 GPa and 1400-1600 °C, with two silicate compositions similar to high-Ti (Apollo 11: A11, ∼11.1 wt.% TiO2, 19.1 wt.% FeO∗, and 39.6 wt.% SiO2) and intermediate-Ti (Luna 16, ∼5 wt.% TiO2, 18.7 wt.% FeO∗, and 43.8 wt.% SiO2) mare basalts. Our experimental results show that SCSS increases with increasing temperature, and decreases with increasing pressure, which are similar to the results from previous experimental studies. SCSS in the A11 melt is systematically higher than that in the Luna 16 melt, which is likely due to higher FeO∗, and lower SiO2 and Al2O3 concentration in the former. Compared to the previously constructed SCSS models, including those designed for high-FeO∗ basalts, the SCSS values determined in this study are generally lower than the predicted values, with overprediction increasing with increasing melt TiO2 content. We attribute this to the lower SiO2 and Al2O3 concentration of the lunar magmas, which is beyond the calibration range of previous SCSS models, and also more abundant FeTiO3 complexes in our experimental melts that have higher TiO2 contents than previous models' calibration range. The formation of FeTiO3 complexes lowers the activity of FeO∗, aFeO∗silicate melt , and therefore causes SCSS to decrease. To accommodate the unique lunar compositions, we have fitted a new SCSS model for basaltic melts of >5 wt.% FeO∗ and variable TiO2 contents. Using previous chalcophile element partitioning experiments that contained more complex Fe-Ni-S sulfide melts, we also derived an empirical correction that allows SCSS calculation for basalts where the equilibrium sulfides contain variable Ni contents of 10-50 wt.%. At the pressures and temperatures of multiple saturation points, SCSS of lunar magmas with compositions from

  2. Sulfur in zircons: A new window into melt chemistry

    Science.gov (United States)

    Tang, H.; Bell, E. A.; Boehnke, P.; Barboni, M.; Harrison, T. M.

    2017-12-01

    The abundance and isotopic composition of sulfur are important tools for exploring the photochemistry of the atmosphere, the thermal history of mantle and igneous rocks, and ancient metabolic processes on the early Earth. Because the oldest terrestrial samples are zircons, we developed a new in-situ procedure to analyze the sulfur content of zircons using the CAMECA ims 1290 at UCLA. We analyzed zircons from three metaluminous/I-type granites (reduced and oxidized Peninsular range and Elba), which exhibit low sulfur abundance with the average of 0.5ppm, and one peraluminous/S-type zircon (Strathbogie Range), which shows an elevated sulfur level with the average of 1.5ppm. Additionally, we found that sulfur content ranges between 0.4 and 2.3 ppm in young volcanic zircons (St. Lucia). Our analyses of zircons from the Jack Hills, Western Australia, whose ages range between 3.4 and 4.1 Ga, show a variety of sulfur contents. Three out of the ten zircons are consistent with the sulfur contents of S-type zircons; the rest have low sulfur contents, which are similar to those of I-type zircons. The high sulfur content in some of these Jack Hills zircons can be interpreted as indicating their origin in either a S-type granite or a volcanic reservoir. We favor the former interpretation since the Ti-in-zircon temperatures of our Jack Hills zircons is lower than those of volcanic zircons. Future work will be undertaken to develop a systematic understanding of the relationship between melt volatile content, melt chemistry, and zircon sulfur content.

  3. Transformation of sulfur during pyrolysis and hydropyrolysis of coal

    Energy Technology Data Exchange (ETDEWEB)

    Chen, H.; Li, B.; Yang, J.; Zhang, B. [Chinese Academy of Sciences, Taiyuan (China). Inst. of Coal Chemistry

    1998-05-01

    It is reported that the transformation of sulfur during pyrolysis (Py) under nitrogen and hydropyrolysis (HyPy) of Chinese Yanzhou high sulfur bituminous coal and Hongmiao lignite was studied in a fixed-bed reactor. The volatile sulfur-containing products were determined by gas chromatography with flame photometric detection. The sulfur in initial coal and char (mainly aliphatic and thiophenic sulfur forms) was quantitatively analyzed using X-ray photoelectron spectroscopy (XPS). The desulfurization yield was calculated by elemental analysis. The main volatile sulfur-containing gas was H{sub 2}S in both Py and HyPy. Both the elemental analysis and XPS results indicated that more sulfur was removed in HyPy than in Py under nitrogen. Thiophenic sulfur can be partially hydrogenated and removed in HyPy. Pyrite can be reduced to a ferrous sulfide completely even as low as 400{degree}C in HyPy while in Py the reduction reaction continues up to 650{degree}C. Mineral matter can not only fix H{sub 2}S produced in Py and HyPy to form higher sulfur content chars but also catalyses the desulfurization reactions to form lower sulfur content tars in HyPy. 24 refs., 8 figs., 4 tabs.

  4. Individual fluctuations of S content in healthy, and smoke-damaged Scots Pine and the relations between S content and contents of other major nutrients

    Energy Technology Data Exchange (ETDEWEB)

    Themlitz, R

    1960-01-01

    This paper compares the sulfur content of pine needles on trees not subject to smoke damage to the sulfur content of pine needles from trees subject to smoke damage. Four stands of pines located in East and West Germany were studied. The data showed no correlation with the sulfur content, with the age of the trees, nor with the uptake of other nutrients.

  5. Sulfur polymer cement concrete

    International Nuclear Information System (INIS)

    Weber, H.H.; McBee, W.C.

    1990-01-01

    Sulfur-based composite materials formulated using sulfur polymer cement (SPC) and mineral aggregates are described and compared with conventional portland cement based materials. Materials characteristics presented include mechanical strength, chemical resistance, impact resistance, moisture permeation, and linear shrinkage during placement and curing. Examples of preparation and placement of sulfur polymer cement concrete (SC) are described using commercial scale equipment. SC applications presented are focused into hostile chemical environments where severe portland cement concrete (PCC) failure has occurred

  6. Sulfur isotope in nature. Determination of sulfur isotope ratios in coal and petroleum by mass spectrometry

    International Nuclear Information System (INIS)

    Derda, M.

    1999-01-01

    Elementary sulfur or in chemical compounds is one of the elements widespread in the earth's crust and biosphere. Its participation in earth's crust amounts to 0.26 % by weight. Measurement of isotope composition of natural samples can deliver many information about origin, creation and transformation ranges of rocks and minerals. Sulfur isotope ratio contained in minerals is variable and for this reason investigation of isotope sulfur composition can deliver useful information about the geochemistry of each component. Therefore in the investigated sample it is necessary to determine not only the content of sulfur but also the isotope composition of each component. Differentiation of contents of sulfur-34 in natural sulfur compounds can reach up to 110 per mile. So large divergences can be explained by a kinetic effect or by bacterial reduction of sulphates. In this report a wide review of the results of investigations of isotope sulfur compositions in coal and petroleum are presented as well as the methods for the preparation of samples for mass spectrometry analysis are proposed. (author)

  7. Release of Chlorine and Sulfur during Biomass Torrefaction and Pyrolysis

    DEFF Research Database (Denmark)

    Saleh, Suriyati Binti; Flensborg, Julie Pauline; Shoulaifar, Tooran Khazraie

    2014-01-01

    The release of chlorine (Cl) and sulfur (S) during biomass torrefaction and pyrolysis has been investigated via experiments in two laboratory-scale reactors: a rotating reactor and a fixed bed reactor. Six biomasses with different chemical compositions covering a wide range of ash content and ash...... reporting that biomasses with a lower chlorine content release a higher fraction of chlorine during the pyrolysis process. A significant sulfur release (about 60%) was observed from the six biomasses investigated at 350 degrees C. The initial sulfur content in the biomass did not influence the fraction...

  8. ADVANCED SULFUR CONTROL CONCEPTS

    Energy Technology Data Exchange (ETDEWEB)

    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).

  9. Estimation of sulfur in coal by fast neutron activation

    International Nuclear Information System (INIS)

    Das, G.C.; Bhattacharyya, P.K.

    1995-01-01

    A simple method is described for estimation of sulfur in coal using fast neutron activation of sulfur, i.e. 32 S(n,p) 32 P and subsequent measurement of 32 P β-activity (1.72 MeV) by a Geiger-Mueller counter. Since the sulfur content of Indian coal ranges from 0.25 to 3%, simulated samples of coal containing sulfur in the range from 0.25 to 3% and common impurities like oxides of aluminium, calcium, iron and silicon have been used to establish the method. (author). 6 refs., 2 figs., 1 tab

  10. Nanostructured sulfur cathodes

    KAUST Repository

    Yang, Yuan

    2013-01-01

    Rechargeable Li/S batteries have attracted significant attention lately due to their high specific energy and low cost. They are promising candidates for applications, including portable electronics, electric vehicles and grid-level energy storage. However, poor cycle life and low power capability are major technical obstacles. Various nanostructured sulfur cathodes have been developed to address these issues, as they provide greater resistance to pulverization, faster reaction kinetics and better trapping of soluble polysulfides. In this review, recent developments on nanostructured sulfur cathodes and mechanisms behind their operation are presented and discussed. Moreover, progress on novel characterization of sulfur cathodes is also summarized, as it has deepened the understanding of sulfur cathodes and will guide further rational design of sulfur electrodes. © 2013 The Royal Society of Chemistry.

  11. Sulfurized activated carbon for high energy density supercapacitors

    Science.gov (United States)

    Huang, Yunxia; Candelaria, Stephanie L.; Li, Yanwei; Li, Zhimin; Tian, Jianjun; Zhang, Lili; Cao, Guozhong

    2014-04-01

    Sulfurized activated carbon (SAC), made by coating the pore surface with thiophenic sulfur functional groups from the pyrolysis of sulfur flakes, were characterized and tested for supercapacitor applications. From X-ray photoelectron spectroscopy (XPS), the sulfur content in the SAC was found to be 2.7 at%. Electrochemical properties from potentiostatic and galvanostatic measurements, and electrochemical impedance spectroscopy (EIS) were used to evaluate the effect of sulfur on porous carbon electrodes. The SAC electrode exhibits better conductivity, and an obvious increase in specific capacitance that is almost 40% higher than plain activated carbons (ACs) electrode at a high current density of 1.4 A g-1. The proposed mechanism for improved conductivity and capacitive performance due to the sulfur functional groups on ACs will be discussed.

  12. 40 CFR 80.580 - What are the sampling and testing methods for sulfur?

    Science.gov (United States)

    2010-07-01

    ... [email protected] from the ASTM Web site of http://www.astm.org. (i) ASTM standard method D2622-05 (“ASTM... methods for sulfur? 80.580 Section 80.580 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... the sampling and testing methods for sulfur? The sulfur content of diesel fuel and diesel fuel...

  13. Effect of sulfur removal on scale adhesion to PWA 1480

    International Nuclear Information System (INIS)

    Smialek, J.L.; Tubbs, B.K.

    1995-01-01

    A commercial superalloy, PWA 1480, was annealed in hydrogen at 1,000 C to 1,300 C in order to remove a 10 ppmw sulfur impurity. This treatment was very successful above 1,200 C, resulting in residual sulfur contents below 0.1 ppmw. The degree of scale adhesion in subsequent 1,100 C cyclic oxidation tests was inversely related to residual sulfur content. Control of adhesion by desulfurization in the absence of reactive elements supports an adhesion mechanism based on oxide-metal bonding weakened by sulfur segregation. Attempts at sulfur purging and improving adhesion by repeated oxidation/polishing were not successful, in contrast to previous studies on NiCrAl

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

    Science.gov (United States)

    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.

  15. Microbial Desulfurization of a Crude Oil Middle-Distillate Fraction: Analysis of the Extent of Sulfur Removal and the Effect of Removal on Remaining Sulfur

    Science.gov (United States)

    Grossman, M. J.; Lee, M. K.; Prince, R. C.; Garrett, K. K.; George, G. N.; Pickering, I. J.

    1999-01-01

    Rhodococcus sp. strain ECRD-1 was evaluated for its ability to desulfurize a 232 to 343°C middle-distillate (diesel range) fraction of Oregon basin (OB) crude oil. OB oil was provided as the sole source of sulfur in batch cultures, and the extent of desulfurization and the chemical fate of the residual sulfur in the oil after treatment were determined. Gas chromatography (GC), flame ionization detection, and GC sulfur chemiluminesce detection analysis were used to qualitatively evaluate the effect of Rhodococcus sp. strain ECRD-1 treatment on the hydrocarbon and sulfur content of the oil, respectively. Total sulfur was determined by combustion of samples and measurement of released sulfur dioxide by infrared absorption. Up to 30% of the total sulfur in the middle distillate cut was removed, and compounds across the entire boiling range of the oil were affected. Sulfur K-edge X-ray absorption-edge spectroscopy was used to examine the chemical state of the sulfur remaining in the treated OB oil. Approximately equal amounts of thiophenic and sulfidic sulfur compounds were removed by ECRD-1 treatment, and over 50% of the sulfur remaining after treatment was in an oxidized form. The presence of partially oxidized sulfur compounds indicates that these compounds were en route to desulfurization. Overall, more than two-thirds of the sulfur had been removed or oxidized by the microbial treatment. PMID:9872778

  16. Mercury adsorption properties of sulfur-impregnated adsorbents

    Science.gov (United States)

    Hsi, N.-C.; Rood, M.J.; Rostam-Abadi, M.; Chen, S.; Chang, R.

    2002-01-01

    Carbonaceous and noncarbonaceous adsorbents were impregnated with elemental sulfur to evaluate the chemical and physical properties of the adsorbents and their equilibrium mercury adsorption capacities. Simulated coal combustion flue gas conditions were used to determine the equilibrium adsorption capacities for Hg0 and HgCl2 gases to better understand how to remove mercury from gas streams generated by coal-fired utility power plants. Sulfur was deposited onto the adsorbents by monolayer surface deposition or volume pore filling. Sulfur impregnation increased the total sulfur content and decreased the total and micropore surface areas and pore volumes for all of the adsorbents tested. Adsorbents with sufficient amounts of active adsorption sites and sufficient microporous structure had mercury adsorption capacities up to 4,509 ??g Hg/g adsorbent. Elemental sulfur, organic sulfur, and sulfate were formed on the adsorbents during sulfur impregnation. Correlations were established with R2>0.92 between the equilibrium Hg0/HgCl2 adsorption capacities and the mass concentrations of elemental and organic sulfur. This result indicates that elemental and organic sulfur are important active adsorption sites for Hg0 and HgCl2.

  17. Parameters Influencing Sulfur Speciation in Environmental Samples Using Sulfur K-Edge X-Ray Absorption Near-Edge Structure

    Directory of Open Access Journals (Sweden)

    Siwatt Pongpiachan

    2012-01-01

    Full Text Available This paper aims to enhance the credibility of applying the sulfur K-edge XANES spectroscopy as an innovative “fingerprint” for characterizing environmental samples. The sensitivities of sulfur K-edge XANES spectra of ten sulfur compound standards detected by two different detectors, namely, Lytle detector (LyD and Germanium detector (GeD, were studied and compared. Further investigation on “self-absorption” effect revealed that the maximum sensitivities of sulfur K-edge XANES spectra were achieved when diluting sulfur compound standards with boron nitride (BN at the mixing ratio of 0.1%. The “particle-size” effect on sulfur K-edge XANES spectrum sensitivities was examined by comparing signal-to-noise ratios of total suspended particles (TSP and particulate matter of less than 10 millionths of a meter (PM10 collected at three major cities of Thailand. The analytical results have demonstrated that the signal-to-noise ratios of sulfur K-edge XANES spectra were positively correlated with sulfate content in aerosols and negatively connected with particle sizes. The combination of hierarchical cluster analysis (HCA and principal component analysis (PCA has proved that sulfur K-edge XANES spectrum can be used to characterize German terrestrial soils and Andaman coastal sediments. In addition, this study highlighted the capability of sulfur K-edge XANES spectra as an innovative “fingerprint” to distinguish tsunami backwash deposits (TBD from typical marine sediments (TMS.

  18. Process for removal of sulfur oxides from hot gases

    International Nuclear Information System (INIS)

    Bauerle, G. L.; Kohl, A. L.

    1984-01-01

    A process for the removal of sulfur oxides from two gas streams containing the same. One gas stream is introduced into a spray dryer zone and contacted with a finely dispersed spray of an aqueous medium containing an absorbent for sulfur oxides. The aqueous medium is introduced at a controlled rate so as to provide water to the gas in an amount to produce a cooled product gas having a temperature at least 7 0 C. above its adiabatic saturation temperature and from about 125-300% of the stoichiometric amount of absorbent required to react with the sulfur oxides to be removed from the gas stream. The effluent from the spray dryer zone comprises a gas stream of reduced sulfur oxide content and contains entrained dry particulate reaction products including unreacted absorbent. This gas stream is then introduced into a particulate removal zone from which is withdrawn a gas stream substantially free of particles and having a reduced sulfur oxide content. the dry particulate reaction products are collected and utilized as a source of absorbent for a second aqueous scrubbing medium containing unreacted absorbent for the sulfur oxides. An effluent gas stream is withdrawn from the aqueous scrubbing zone and comprises a water-saturated gas stream of reduced sulfur oxide content and substantially free of particles. The effluent gas streams from the particulate removal zone and the aqueous scrubbing zone are combined in such proportions that the combined gas stream has a temperature above its adiabatic saturation temperature

  19. Aircraft exhaust sulfur emissions

    Energy Technology Data Exchange (ETDEWEB)

    Brown, R C; Anderson, M R; Miake-Lye, R C; Kolb, C E [Aerodyne Research, Inc., Billerica, MA (United States). Center for Chemical and Environmental Physics; Sorokin, A A; Buriko, Y I [Scientific Research Center ` Ecolen` , Moscow (Russian Federation)

    1998-12-31

    The extent to which fuel sulfur is converted to SO{sub 3} during combustion and the subsequent turbine flow in supersonic and subsonic aircraft engines is estimated numerically. The analysis is based on: a flamelet model with non-equilibrium sulfur chemistry for the combustor, and a one-dimensional, two-stream model with finite rate chemical kinetics for the turbine. The results indicate that between 2% and 10% of the fuel sulfur is emitted as SO{sub 3}. It is also shown that, for a high fuel sulfur mass loading, conversion in the turbine is limited by the level of atomic oxygen at the combustor exit, leading to higher SO{sub 2} oxidation efficiency at lower fuel sulfur loadings. While SO{sub 2} and SO{sub 3} are the primary oxidation products, the model results further indicate H{sub 2}SO{sub 4} levels on the order of 0.1 ppm for supersonic expansions through a divergent nozzle. This source of fully oxidized S(6) (SO{sub 3} + H{sub 2}SO{sub 4}) exceeds previously calculated S(6) levels due to oxidation of SO{sub 2} by OH in the exhaust plume outside the engine nozzle. (author) 26 refs.

  20. Aircraft exhaust sulfur emissions

    Energy Technology Data Exchange (ETDEWEB)

    Brown, R.C.; Anderson, M.R.; Miake-Lye, R.C.; Kolb, C.E. [Aerodyne Research, Inc., Billerica, MA (United States). Center for Chemical and Environmental Physics; Sorokin, A.A.; Buriko, Y.I. [Scientific Research Center `Ecolen`, Moscow (Russian Federation)

    1997-12-31

    The extent to which fuel sulfur is converted to SO{sub 3} during combustion and the subsequent turbine flow in supersonic and subsonic aircraft engines is estimated numerically. The analysis is based on: a flamelet model with non-equilibrium sulfur chemistry for the combustor, and a one-dimensional, two-stream model with finite rate chemical kinetics for the turbine. The results indicate that between 2% and 10% of the fuel sulfur is emitted as SO{sub 3}. It is also shown that, for a high fuel sulfur mass loading, conversion in the turbine is limited by the level of atomic oxygen at the combustor exit, leading to higher SO{sub 2} oxidation efficiency at lower fuel sulfur loadings. While SO{sub 2} and SO{sub 3} are the primary oxidation products, the model results further indicate H{sub 2}SO{sub 4} levels on the order of 0.1 ppm for supersonic expansions through a divergent nozzle. This source of fully oxidized S(6) (SO{sub 3} + H{sub 2}SO{sub 4}) exceeds previously calculated S(6) levels due to oxidation of SO{sub 2} by OH in the exhaust plume outside the engine nozzle. (author) 26 refs.

  1. Environmental aspects of the combustion of sulfur-bearing fuels

    International Nuclear Information System (INIS)

    Manowitz, B.; Lipfert, F.W.

    1990-01-01

    This paper describes the origins of sulfur in fossil fuels and the consequences of its release into the environment after combustion, with emphasis on the United States. Typical sulfur contents of fuels are given, together with fuel uses and the resulting air concentrations of sulfur air pollutants. Atmospheric transformation and pollutant removal processes are described, as they affect the pathways of sulfur through the environment. The environmental effects discussed include impacts on human health, degradation of materials, acidification of ecosystems, and effects on vegetation and atmospheric visibility. The paper concludes with a recommendation for the use of risk assessment to assess the need for regulations which may require the removal of sulfur from fuels or their combustion products

  2. Biodesulfurization of refractory organic sulfur compounds in fossil fuels.

    Science.gov (United States)

    Soleimani, Mehran; Bassi, Amarjeet; Margaritis, Argyrios

    2007-01-01

    The stringent new regulations to lower sulfur content in fossil fuels require new economic and efficient methods for desulfurization of recalcitrant organic sulfur. Hydrodesulfurization of such compounds is very costly and requires high operating temperature and pressure. Biodesulfurization is a non-invasive approach that can specifically remove sulfur from refractory hydrocarbons under mild conditions and it can be potentially used in industrial desulfurization. Intensive research has been conducted in microbiology and molecular biology of the competent strains to increase their desulfurization activity; however, even the highest activity obtained is still insufficient to fulfill the industrial requirements. To improve the biodesulfurization efficiency, more work is needed in areas such as increasing specific desulfurization activity, hydrocarbon phase tolerance, sulfur removal at higher temperature, and isolating new strains for desulfurizing a broader range of sulfur compounds. This article comprehensively reviews and discusses key issues, advances and challenges for a competitive biodesulfurization process.

  3. Biodiesel as a lubricity additive for ultra low sulfur diesel

    Directory of Open Access Journals (Sweden)

    Subongkoj Topaiboul1 and 2,*

    2010-05-01

    Full Text Available With the worldwide trend to reduce emission from diesel engines, ultra low sulfur diesel has been introduced with thesulfur concentration of less than 10 ppm. Unfortunately, the desulfurization process inevitably reduces the lubricity of dieselfuel significantly. Alternatively, biodiesel, with almost zero sulfur content, has been added to enhance lubricity in an ultralow sulfur diesel. This work has evaluated the effectiveness of the biodiesel amount, sourced from palm and jatropha oil,and origin in ultra low sulfur diesel locally available in the market. Wear scar from a high-frequency reciprocating rig isbenchmarked to the standard value (460 m of diesel fuel lubricity. It was found that very small amount (less than 1% ofbiodiesel from either source significantly improves the lubricity in ultra low sulfur diesel, and the biodiesel from jatropha oilis a superior lubricity enhancer.

  4. Sulfur activation in Hiroshima

    International Nuclear Information System (INIS)

    Kerr, G.D.; Pace, J.V. III.

    1987-01-01

    In 1979, we attempted to establish the validity of source terms for the Hiroshima and Nagasaki bombs using experimental data on sulfur activation. Close agreement was observed between measured and calculated values for test firings of Nagasaki-type bombs. The calculated values were based on source terms developed by W.E. Preeg at the Los Alamos National Laboratory (LANL). A discrepancy was found, however, when we compared calculated values for the two bombs because a 1956 report by R.R. Wilson stated that sulfur acitvation by fast neutrons in Hiroshima was approximately three times greater than in Nagasaki. Our calculations based on Preeg's source-term data predicted about equal sulfur activation in the two cities

  5. Partial substitution of asphalt pavement with modified sulfur

    Directory of Open Access Journals (Sweden)

    E.R. Souaya

    2015-12-01

    Full Text Available The use of sulfur in pavement laying was developed in 1980 but it was restricted in the late 19th century due to its environmental problems and its high reactivity toward oxidation processes which give sulfuric acid products that are capable of destroying the asphalt mixture. The study involved the conversion of elemental sulfur to a more stable modified one using a combination of byproducts of olefin hydrocarbons that were obtained from petroleum fractional distillates and cyclic hydrocarbon bituminous residue at 145 °C. The changes in the structural characteristics and morphology of prepared modified sulfur were studied using XRD and SEM respectively. Also DSC curves help us to elucidate the changes in sulfur phases from α-orthorhombic to β-mono clinic structure. The technique of nanoindentation helps us to compare the mechanical properties of modified and pure sulfur including modulus of elasticity and hardness. The hot mixture asphalt designs were prepared according to the Marshall Method in which the asphalt binder content was partially substituted with 20%, 30%, 40%, and 50% modified sulfur. The mechanical properties were measured including Marshall Stability, flow, air voids, and Marshall Stiffness. From the overall study, the results indicated that asphalt could partially be substituted with modified sulfur with no significant deleterious effect on performance and durability of hot mixed asphalt.

  6. Accidents with sulfuric acid

    Directory of Open Access Journals (Sweden)

    Rajković Miloš B.

    2006-01-01

    Full Text Available Sulfuric acid is an important industrial and strategic raw material, the production of which is developing on all continents, in many factories in the world and with an annual production of over 160 million tons. On the other hand, the production, transport and usage are very dangerous and demand measures of precaution because the consequences could be catastrophic, and not only at the local level where the accident would happen. Accidents that have been publicly recorded during the last eighteen years (from 1988 till the beginning of 2006 are analyzed in this paper. It is very alarming data that, according to all the recorded accidents, over 1.6 million tons of sulfuric acid were exuded. Although water transport is the safest (only 16.38% of the total amount of accidents in that way 98.88% of the total amount of sulfuric acid was exuded into the environment. Human factor was the common factor in all the accidents, whether there was enough control of the production process, of reservoirs or transportation tanks or the transport was done by inadequate (old tanks, or the accidents arose from human factor (inadequate speed, lock of caution etc. The fact is that huge energy, sacrifice and courage were involved in the recovery from accidents where rescue teams and fire brigades showed great courage to prevent real environmental catastrophes and very often they lost their lives during the events. So, the phrase that sulfuric acid is a real "environmental bomb" has become clearer.

  7. Structure of amorphous sulfur

    CSIR Research Space (South Africa)

    Eichinger, BE

    2001-06-01

    Full Text Available The lambda-transition of elemental sulfur occurring at about 159°C has long been associated with the conversion of cyclic S8 rings (c-S8) to amorphous polymer (a-S) via a ring opening polymerization. It is demonstrated, with the use of both density...

  8. SULFUR POLYMER ENCAPSULATION

    International Nuclear Information System (INIS)

    KALB, P.

    2001-01-01

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

  9. 75 FR 7426 - Tier 2 Light-Duty Vehicle and Light-Duty Truck Emission Standards and Gasoline Sulfur Control...

    Science.gov (United States)

    2010-02-19

    ... 2060-AI23; 2060-AQ12 Tier 2 Light-Duty Vehicle and Light-Duty Truck Emission Standards and Gasoline.... The rulemaking also required oil refiners to limit the sulfur content of the gasoline they produce. Sulfur in gasoline has a detrimental impact on catalyst performance and the sulfur requirements have...

  10. Composition of atmospheric precipitation. II. Sulfur, chloride, iodine compounds. Bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, E

    1952-01-01

    Atmospheric precipitation invariably contains insoluble substances of different origin. A large scale study was conducted to determine the content of sulfur, chloride, and iodine in rainwater from various places around the world. The origin of these elements in rainwater is discussed. Several meteorological factors influence the Cl-content of rainwater. They include: rainfall, wind direction and wind strength, altitude, and seasonal variation.

  11. Sulfur flows and biosolids processing: Using Material Flux Analysis (MFA) principles at wastewater treatment plants.

    Science.gov (United States)

    Fisher, R M; Alvarez-Gaitan, J P; Stuetz, R M; Moore, S J

    2017-08-01

    High flows of sulfur through wastewater treatment plants (WWTPs) may cause noxious gaseous emissions, corrosion of infrastructure, inhibit wastewater microbial communities, or contribute to acid rain if the biosolids or biogas is combusted. Yet, sulfur is an important agricultural nutrient and the direct application of biosolids to soils enables its beneficial re-use. Flows of sulfur throughout the biosolids processing of six WWTPs were investigated to identify how they were affected by biosolids processing configurations. The process of tracking sulfur flows through the sites also identified limitations in data availability and quality, highlighting future requirements for tracking substance flows. One site was investigated in more detail showing sulfur speciation throughout the plant and tracking sulfur flows in odour control systems in order to quantify outflows to air, land and ocean sinks. While the majority of sulfur from WWTPs is removed as sulfate in the secondary effluent, the sulfur content of biosolids is valuable as it can be directly returned to soils to combat the potential sulfur deficiencies. Biosolids processing configurations, which focus on maximising solids recovery, through high efficiency separation techniques in primary sedimentation tanks, thickeners and dewatering centrifuges retain more sulfur in the biosolids. However, variations in sulfur loads and concentrations entering the WWTPs affect sulfur recovery in the biosolids, suggesting industrial emitters, and chemical dosing of iron salts are responsible for differences in recovery between sites. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. [Sulfur dioxide limit standard and residues in Chinese medicinal materials].

    Science.gov (United States)

    Kang, Chuan-Zhi; Yang, Wan-Zhen; Mo, Ge; Zhou, Li; Jiang, Jing-Yi; Lv, Chao-Geng; Wang, Sheng; Zhou, Tao; Yang, Ye; Guo, Lan-Ping

    2018-01-01

    The traditional sulfur fumigation processing method has been widely used in the initial processing and storage of traditional Chinese medicinal materials due to its economy, efficiency, convenience, high operability and effect on mold and insect prevention. However, excessive sulfur fumigation of traditional Chinese medicinal materials would lead to the changes in chemical compositions, and even endanger human health. This study showed that traditional Chinese medicinal materials were sulfur fumigated directly after being harvested for quick drying, or fumigated after being weted in the storage process for preventing mold and insects. We found that the sulfur dioxide limits for traditional Chinese medicinal materials were stricter than those for foods. Based on the existing limit standards, we obtained the data of sulfur dioxide residues for 35 types of traditional Chinese medicinal materials in a total of 862 batches. According to the limit standard in the Chinese Pharmacopoeia (150, 400 mg·kg⁻¹), the average over-standard rate of sulfur dioxide was as high as 52.43%, but it was reduced to 29.47% if calculated based on the limit for vegetable additive standard (500 mg·kg⁻¹). Sulfur fumigation issue shall be considered correctly: sulfur dioxide is a type of low toxic substance and less dangerous than aflatoxin and other highly toxic substances, and a small amount of residue would not increase the toxicity of traditional Chinese medicinal materials. However, sulfur fumigation might change the content of chemical substances and affect the quality of traditional Chinese medicinal materials. Furthermore, the exposure hazards of toxic substances are comprehensively correlated with exposure cycle, exposure frequency, and application method. In conclusion, it is suggested to strengthen the studies on the limit standard of traditional Chinese medicinal materials, formulate practical and feasible limit standard for sulfur dioxide residues in traditional Chinese

  13. Getting sulfur on target

    Energy Technology Data Exchange (ETDEWEB)

    Halbert, T.R.; Brignac, G.B. [ExxonMobil Process Research Labs. (United States); Greeley, J.P.; Demmin, R.A.; Roundtree, E.M. [ExxonMobil Research and Engineering Co. (United States)

    2000-06-01

    The paper focuses on how the required reductions in sulfur levels in motor vehicle fuel may be achieved over about the next five years. It is said that broadly there are two possible approaches, they are: (a) to hydrotreat the feed to the FCC unit and (b) to treat the naphtha produced by the FCC unit. The difficulties associated with these processes are mentioned. The article is presented under the sub-headings of (i) technology options for cat naphtha desulfurisation; (ii) optimising fractionator design via improved VLE models; (iii) commercial experience with ICN SCANfining; (iv) mercaptan predictive models and (v) process improvements. It was concluded that the individual needs of the refiner can be addressed by ExxonMobil Research and Engineering (EMRE) and the necessary reductions in sulfur levels can be achieved.

  14. Accidents with sulfuric acid

    OpenAIRE

    Rajković Miloš B.

    2006-01-01

    Sulfuric acid is an important industrial and strategic raw material, the production of which is developing on all continents, in many factories in the world and with an annual production of over 160 million tons. On the other hand, the production, transport and usage are very dangerous and demand measures of precaution because the consequences could be catastrophic, and not only at the local level where the accident would happen. Accidents that have been publicly recorded during the last eigh...

  15. Acidophilic sulfur disproportionation

    Science.gov (United States)

    Hardisty, Dalton S.; Olyphant, Greg A.; Bell, Jonathan B.; Johnson, Adam P.; Pratt, Lisa M.

    2013-07-01

    Bacterial disproportionation of elemental sulfur (S0) is a well-studied metabolism and is not previously reported to occur at pH values less than 4.5. In this study, a sediment core from an abandoned-coal-mine-waste deposit in Southwest Indiana revealed sulfur isotope fractionations between S0 and pyrite (Δ34Ses-py) of up to -35‰, inferred to indicate intense recycling of S0 via bacterial disproportionation and sulfide oxidation. Additionally, the chemistry of seasonally collected pore-water profiles were found to vary, with pore-water pH ranging from 2.2 to 3.8 and observed seasonal redox shifts expressed as abrupt transitions from Fe(III) to Fe(II) dominated conditions, often controlled by fluctuating water table depths. S0 is a common product during the oxidation of pyrite, a process known to generate acidic waters during weathering and production of acid mine drainage. The H2S product of S0 disproportionation, fractionated by up to -8.6‰, is rapidly oxidized to S0 near redox gradients via reaction with Fe(III) allowing for the accumulation of isotopically light S0 that can then become subject to further sulfur disproportionation. A mass-balance model for S0 incorporating pyrite oxidation, S0 disproportionation, and S0 oxidation readily explains the range of observed Δ34Ses-py and emphasizes the necessity of seasonally varying pyrite weathering and metabolic rates, as indicated by the pore water chemistry. The findings of this research suggest that S0 disproportionation is potentially a common microbial process at a pH < 4.5 and can create large sulfur isotope fractionations, even in the absence of sulfate reduction.

  16. Sulfur recirculation for increased electricity production in Waste-to-Energy plants.

    Science.gov (United States)

    Andersson, Sven; Blomqvist, Evalena W; Bäfver, Linda; Jones, Frida; Davidsson, Kent; Froitzheim, Jan; Karlsson, Martin; Larsson, Erik; Liske, Jesper

    2014-01-01

    Sulfur recirculation is a new technology for reducing boiler corrosion and dioxin formation. It was demonstrated in full-scale tests at a Waste to Energy plant in Göteborg (Sweden) during nearly two months of operation. Sulfur was recirculated as sulfuric acid from the flue gas cleaning back to the boiler, thus creating a sulfur loop. The new technology was evaluated by extensive measurement campaigns during operation under normal conditions (reference case) and operation with sulfur recirculation. The chlorine content of both fly ash and boiler ash decreased and the sulfur content increased during the sulfur recirculation tests. The deposit growth and the particle concentration decreased with sulfur recirculation and the dioxin concentration (I-TEQ) of the flue gas was reduced by approximately 25%. Sulfuric acid dew point measurements showed that the sulfuric acid dosage did not lead to elevated SO3 concentrations, which may otherwise induce low temperature corrosion. In the sulfur recirculation corrosion probe exposures, the corrosion rate decreased for all tested materials (16Mo3, Sanicro 28 and Inconel 625) and material temperatures (450 °C and 525 °C) compared to the reference exposure. The corrosion rates were reduced by 60-90%. Sulfur recirculation prevented the formation of transition metal chlorides at the metal/oxide interface, formation of chromate and reduced the presence of zinc in the corrosion products. Furthermore, measured corrosion rates at 525 °C with sulfur recirculation in operation were similar or lower compared to those measured at 450 °C material temperature in reference conditions, which corresponds to normal operation at normal steam temperatures. This implies that sulfur recirculation allows for higher steam data and electricity production without increasing corrosion. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  17. Standard practice for preparing sulfur prints for macrostructural evaluation

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This practice provides information required to prepare sulfur prints (also referred to as Baumann Prints) of most ferrous alloys to reveal the distribution of sulfide inclusions. 1.2 The sulfur print reveals the distribution of sulfides in steels with bulk sulfur contents between about 0.010 and 0.40 weight percent. 1.3 Certain steels contain complex sulfides that do not respond to the test solutions, for example, steels containing titanium sulfides or chromium sulfides. 1.4 The sulfur print test is a qualitative test. The density of the print image should not be used to assess the sulfur content of a steel. Under carefully controlled conditions, it is possible to compare print image intensities if the images are formed only by manganese sulfides. 1.5 The sulfur print image will reveal details of the solidification pattern or metal flow from hot or cold working on appropriately chosen and prepared test specimens. 1.6 This practice does not address acceptance criteria based on the use of the method. ...

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

    Science.gov (United States)

    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.

  19. Determination of sulfur in solids by constant current coulometric titration following combustion

    International Nuclear Information System (INIS)

    Monteiro, R.P.G.

    1986-01-01

    A method for determination of sulfur in solid materials by combustion in induction furnace, followed by constant current coulometric titration of the sulfur dioxide produced, is described. The method is applicable to samples with sulfur contents of 80 ppm to 20,000 ppm. Its feasibility was checked on the NBS and Leco steel samples. The results are in good agreement with the specified values. (author) [pt

  20. Studies on the sulfur metabolism of cows on protein-free and low-protein feed

    Directory of Open Access Journals (Sweden)

    Eino Matikkala

    1977-09-01

    Full Text Available The influence of purified, protein-free feed with urea and ammonium salts as nitrogen sources (0-feed and of non-purified, urea-rich, low-protein feeds (ULP-feed on the sulfur metabolism of cows has been studied by determining the contents of sulfur fractions in faeces, urine, milk, blood and rumen fluid. The sulfur of 0-feed was composed entirely of inorganic sulfate. During balance trials the N:S ratio in the feed varied from 6.1 to 9.5, and the sulfur content from 0.22 to 0.31 % of the dry matter. In every trial (seven with 0-feed and two with ULP-feed, of five or seven days duration, the cows were in high-positive sulfur balance. The 0-cows excreted a greater proportion of their total sulfur output via urine than the ULP-cows. The excretion of inorganic sulfate sulfur, as a proportion of the urinary and faecal sulfur, was greater for 0-cows than for ULP- or NorP-cows (cows on normal, protein-rich feed; the opposite was the case with regard to the excretion of ester sulfate sulfur and neutral sulfur. The sulfur contents of milk and blood showed only minor inter-feed differences. The sulfate content in the rumen fluid of the 0-cow rose rapidly after the commencement of feeding and then fell quite rapidly. We conclude tentatively that in the rumen of the 0-cow hydrogen sulfide is generated so quickly that the whole of it cannot be used for the synthesis of sulfur-containing compounds, a considerable proportion of it being lost in eructations or excreted as inorganic sulfates in the urine.

  1. Synergy effect of naphthenic acid corrosion and sulfur corrosion in crude oil distillation unit

    Energy Technology Data Exchange (ETDEWEB)

    Huang, B.S., E-mail: yinwenfeng2010@163.com [College of Materials Science and Engineering, Southwest Petroleum University, Sichuan, Chengdu, 610500 (China); Yin, W.F. [College of Mechatronic Engineering, Southwest Petroleum University, Sichuan, Chengdu, 610500 (China); Sang, D.H. [Sheng Li Construction Group International Engineering Department, Shandong, Dongying, 257000 (China); Jiang, Z.Y. [College of Materials Science and Engineering, Southwest Petroleum University, Sichuan, Chengdu, 610500 (China)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer The corrosion of a carbon-manganese steel and a stainless steel in sulfur and/or naphthenic acid media was investigated. Black-Right-Pointing-Pointer The corrosion rate of the carbon-manganese steel increased with the increase of the acid value and sulfur content. Black-Right-Pointing-Pointer The critical values of the concentration of sulfur and acid for corrosion rate of the stainless steel were ascertained respectively. Black-Right-Pointing-Pointer The stainless steel is superior to the carbon-manganese steel in corrosion resistance because of the presence of stable Cr{sub 5}S{sub 8} phases. - Abstract: The synergy effect of naphthenic acid corrosion and sulfur corrosion at high temperature in crude oil distillation unit was studied using Q235 carbon-manganese steel and 316 stainless steel. The corrosion of Q235 and 316 in corrosion media containing sulfur and/or naphthenic acid at 280 Degree-Sign C was investigated by weight loss, scanning electron microscope (SEM), EDS and X-ray diffractometer (XRD) analysis. The results showed that in corrosion media containing only sulfur, the corrosion rate of Q235 and 316 first increased and then decreased with the increase of sulfur content. In corrosion media containing naphthenic acid and sulfur, with the variations of acid value or sulfur content, the synergy effect of naphthenic acid corrosion and sulfur corrosion has a great influence on the corrosion rate of Q235 and 316. It was indicated that the sulfur accelerated naphthenic acid corrosion below a certain sulfur content but prevented naphthenic acid corrosion above that. The corrosion products on two steels after exposure to corrosion media were investigated. The stable Cr{sub 5}S{sub 8} phases detected in the corrosion products film of 316 were considered as the reason why 316 has greater corrosion resistance to that of Q235.

  2. Sulfur and octane trade off in FCC naphta conventional hydrotreating

    Energy Technology Data Exchange (ETDEWEB)

    Badra, C. [INTEVEP S.A. Research and Technological Support Center of Petroleos de Venzuela, Caracas (Venezuela). Dept. de Refinacion; Perez, J.A. [INTEVEP S.A. Research and Technological Support Center of Petroleos de Venzuela, Caracas (Venezuela). Dept. de Refinacion; Salazar, J.A. [INTEVEP S.A. Research and Technological Support Center of Petroleos de Venzuela, Caracas (Venezuela). Dept. de Refinacion; Cabrera, L. [INTEVEP S.A. Research and Technological Support Center of Petroleos de Venzuela, Caracas (Venezuela). Dept. de Refinacion; Gracia, W. [INTEVEP S.A. Research and Technological Support Center of Petroleos de Venzuela, Caracas (Venezuela). Dept. de Refinacion

    1997-06-01

    A model to predict the change of octane numbers expected in an FCC naphtha hydrotreating process as a function of the hydroprocessing severity (degree of sulfur removal) and the type of naphtha (expressed as the sulfur content and bromine number in the feedstock) is presented. When considering hydrotreating as an option for processing their catalytic naphthas, refiners search for the proper balance between the desired reduction of sulfur and olefins and the resulting undesired reduction of octane (RON and MON). In doing so, refiners should study the possibility of performing the hydrotreating at mild severities and/or the possibility of fractionating FCC naphthas to just treat a specific cut. This paper provides simple tools to study and analyze these study cases and to assess the sulfur-octane trade offs. (orig.)

  3. The production of sulfur targets for gamma-ray spectroscopy

    CERN Document Server

    Greene, J P

    2002-01-01

    The production of thin sulfur targets for nuclear physics, either in elemental or in compound form, is problematic, due to low melting points, high vapor pressures and high dissociation rates. Many sulfur compounds have been tried in the past without great success. In this paper, we report the use of spray coating molybdenum disulfide onto a thin carbon backing. The targets were of thickness 750 mu g/cm sup 2 (approx 300 mu g/cm sup 2 of sulfur) on 15 mu g/cm sup 2 carbon backings, and withstood 4 pnA (approx 10 mW/cm sup 2) of deposited beam power for several days without apparent loss of sulfur content.

  4. Synergy effect of naphthenic acid corrosion and sulfur corrosion in crude oil distillation unit

    Science.gov (United States)

    Huang, B. S.; Yin, W. F.; Sang, D. H.; Jiang, Z. Y.

    2012-10-01

    The synergy effect of naphthenic acid corrosion and sulfur corrosion at high temperature in crude oil distillation unit was studied using Q235 carbon-manganese steel and 316 stainless steel. The corrosion of Q235 and 316 in corrosion media containing sulfur and/or naphthenic acid at 280 °C was investigated by weight loss, scanning electron microscope (SEM), EDS and X-ray diffractometer (XRD) analysis. The results showed that in corrosion media containing only sulfur, the corrosion rate of Q235 and 316 first increased and then decreased with the increase of sulfur content. In corrosion media containing naphthenic acid and sulfur, with the variations of acid value or sulfur content, the synergy effect of naphthenic acid corrosion and sulfur corrosion has a great influence on the corrosion rate of Q235 and 316. It was indicated that the sulfur accelerated naphthenic acid corrosion below a certain sulfur content but prevented naphthenic acid corrosion above that. The corrosion products on two steels after exposure to corrosion media were investigated. The stable Cr5S8 phases detected in the corrosion products film of 316 were considered as the reason why 316 has greater corrosion resistance to that of Q235.

  5. Effect of sulfur removal on Al2O3 scale adhesion

    Science.gov (United States)

    Smialek, James L.

    1991-03-01

    If the role of reactive element dopants in producing A12O3 scale adhesion on NiCrAl alloys is to getter sulfur and prevent interfacial segregation, then eliminating sulfur from undoped alloys should also produce adherence. Four experiments successfully produced scale adhesion by sulfur removal alone. (1) Repeated oxidation and polishing of a pure NiCrAl alloy lowered the sulfur content from 10 to 2 parts per million by weight (ppmw), presumably by removing the segregated interfacial layer after each cycle. Total scale spallation changed to total retention after 13 such cycles, with no changes in the scale or interfacial morphology. (2) Thinner samples became adherent after fewer oxidation polishing cycles because of a more limited supply of sulfur. (3) Spalling in subsequent cyclic oxidation tests of samples from experiment (1) was a direct function of the initial sulfur content. (4) Desulfurization to 0.1 ppmw levels was accomplished by annealing melt-spun foil in 1 arm H2. These foils produced oxidation weight change curves for 500 1-hour cycles at 1100 °C similar to those for Y- or Zr-doped NiCrAl. The transition between adherent and nonadherent behavior was modeled in terms of sulfur flux, sulfur content, and sulfur segregation.

  6. Diesel Emission Control -- Sulfur Effects (DECSE) Program; Phase I Interim Date Report No. 3: Diesel Fuel Sulfur Effects on Particulate Matter Emissions

    Energy Technology Data Exchange (ETDEWEB)

    DOE; ORNL; NREL; EMA; MECA

    1999-11-15

    The Diesel Emission Control-Sulfur Effects (DECSE) is a joint government/industry program to determine the impact of diesel fuel sulfur levels on emission control systems whose use could lower emissions of nitrogen oxides (NO{sub x}) and particulate matter (PM) from on-highway trucks in the 2002--2004 model years. Phase 1 of the program was developed with the following objectives in mind: (1) evaluate the effects of varying the level of sulfur content in the fuel on the emission reduction performance of four emission control technologies; and (2) measure and compare the effects of up to 250 hours of aging on selected devices for multiple levels of fuel sulfur content. This interim report covers the effects of diesel fuel sulfur level on particulate matter emissions for four technologies.

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

    Science.gov (United States)

    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.

  8. Phosphorus, sulfur and pyridine

    OpenAIRE

    Schönberger, Stefanie

    2013-01-01

    The synthesis of distinct neutral or anionic P,S compounds in solution provides a great challenge for chemists. Due to the similarity in the energies of the P–P, P–S and S–S bonds nearly solely a mixture of compounds with different composition and charge is obtained. Our interest focuses on the system consisting of phosphorus, sulfur and pyridine, with the aim of a greater selectivity of P,S compounds in solution. The combination of these three components offers the opportunity...

  9. Influence of sulfur and nitrogen supply on the susceptibility of Pisum sativum to SO/sub 2/

    Energy Technology Data Exchange (ETDEWEB)

    Klein, H; Jaeger, H J; Steubing, L

    1974-01-01

    The susceptibility of Pisum to SO/sub 2/ injury was examined in relation to the sulfur and nitrogen nutrition. The injury was measured by comparing the dry matter yield to control and treated plants. SO/sub 2/ effects on metabolism were established by determining the content of organic and inorganic sulfur and, indirectly, by measuring total nitrogen, amino acid nitrogen, and protein nitrogen. The plants grown in nutrient solutions deficient in sulfur or nitrogen showed a decreased sensitivity to SO/sub 2/ pollution compared to the control. The higher content of amino acid nitrogen and organic sulfur of the plants grown in a nitrogen-deficient solution suggests that an increased synthesis of sulfur containing amino acids occurs. The slighter injury of the plants deficient in sulfur may be explained by the delayed sulfur supply.

  10. Specific gravity and API gravity of biodiesel and ultra-low sulfur diesel (ULSD) blends

    Science.gov (United States)

    Biodiesel is an alternative fuel made from vegetable oils and animal fats. In 2006, the U. S. Environmental Protection Agency mandated a maximum sulfur content of 15 ppm in on-road diesel fuels. Processing to produce the new ultra-low sulfur petrodiesel (ULSD) alters specific gravity (SG) and othe...

  11. Panorama 2018 - Reducing sulfur emissions in shipping: an economic and technological challenge

    International Nuclear Information System (INIS)

    Dumas, Cecile; Marion, Pierre; Saint Antonin, Valerie; Weiss, Wilfried

    2018-01-01

    Sulfur oxides emissions from maritime traffic are constantly rising, unlike those generated by all land-based sources, which are subject to numerous regulations on both fuels and emission caps on equipment that uses them. Accordingly, the International Maritime Organization (IMO) adopted a resolution to reduce the sulfur content of marine fuels, but its implementation, set for 2020, could prove complicated. (authors)

  12. Research on the Composition and Distribution of Organic Sulfur in Coal.

    Science.gov (United States)

    Zhang, Lanjun; Li, Zenghua; Yang, Yongliang; Zhou, Yinbo; Li, Jinhu; Si, Leilei; Kong, Biao

    2016-05-13

    The structure and distribution of organic sulfur in coals of different rank and different sulfur content were studied by combining mild organic solvent extraction with XPS technology. The XPS results have shown that the distribution of organic sulfur in coal is related to the degree of metamorphism of coal. Namely, thiophenic sulfur content is reduced with decreasing metamorphic degree; sulfonic acid content rises with decreasing metamorphic degree; the contents of sulfate sulfur, sulfoxide and sulfone are rarely related with metamorphic degree. The solvent extraction and GC/MS test results have also shown that the composition and structure of free and soluble organic sulfur small molecules in coal is closely related to the metamorphic degree of coal. The free organic sulfur small molecules in coal of low metamorphic degree are mainly composed of aliphatic sulfides, while those in coal of medium and high metamorphic degree are mainly composed of thiophenes. Besides, the degree of aromatization of organic sulfur small molecules rises with increasing degree of coalification.

  13. Lithium sulfur batteries and electrolytes and sulfur cathodes thereof

    Science.gov (United States)

    Visco, Steven J.; Goncharenko, Nikolay; Nimon, Vitaliy; Petrov, Alexei; Nimon, Yevgeniy S.; De Jonghe, Lutgard C.; Katz, Bruce D.; Loginova, Valentina

    2017-05-23

    Lithium sulfur battery cells that use water as an electrolyte solvent provide significant cost reductions. Electrolytes for the battery cells may include water solvent for maintaining electroactive sulfur species in solution during cell discharge and a sufficient amount of a cycle life-enhancing compound that facilitates charging at the cathode. The combination of these two components enhances one or more of the following cell attributes: energy density, power density and cycle life. For instance, in applications where cost per Watt-Hour (Wh) is paramount, such as grid storage and traction applications, the use of an aqueous electrolyte in combination with inexpensive sulfur as the cathode active material can be a key enabler for the utility and automotive industries, for example, providing a cost effective and compact solution for load leveling, electric vehicles and renewable energy storage. Sulfur cathodes, and methods of fabricating lithium sulfur cells, in particular for loading lithium sulfide into the cathode structures, provide further advantages.

  14. Reduced graphene oxide encapsulated sulfur spheres for the lithium-sulfur battery cathode

    Directory of Open Access Journals (Sweden)

    Feiyan Liu

    Full Text Available Reduced graphene oxide (rGO encapsulated sulfur spheres for the Li-S batteries were prepared via the redox reaction between sodium polysulfide. XRD spectra showed that the diffraction peak of graphite oxide (GO at 10° disappeared, while the relatively weak diffraction peak at 27° belongs to graphene emerged. FT-IR spectra showed that the vibrations of the functional groups of GO, such as 3603 cm−1, 1723 cm−1and 1619 cm−1 which contributed from OH, COC and CO respectively, disappeared when compared to the spectra of GSC. SEM observations indicated that the optimum experimental condition followed as: mass ratio of GO and S was 1:1, 10% NaOH was used to adjust the pH. EDX analysis showed that the sulfur content reached at 68.8% of the composite material. The resultant electric resistance was nearly less than GO’s resistance in three orders of magnitude under same condition. Further electrochemical performance tests showed a coulombic efficiency was 96% from the first cycle capacity was 827 mAh g−1, to 388 mAh g−1 in the 100 cycles. This study carries substantial significance to the development of Li-S battery cathode materials. Keywords: Lithium-sulfur battery, Graphene, Sulfur spheres, Cathode material

  15. Dynamics of a Novel Class of Polymers: Polymerized Sulfur

    Science.gov (United States)

    Masser, Kevin; Kim, Jenny; Oleshko, Vladimir; Griebel, Jared; Chung, Woo; Simmons, Adam; Pyun, Jeff; Soles, Christopher

    2013-03-01

    In this study we investigate the dynamics of a new type of polymer, consisting mainly of sulfur. Room-temperature stable polymerized sulfur samples were prepared by crosslinking the well-known living sulfur polymers formed at elevated temperatures by the addition of a crosslinking agent. This reverse vulcanization process was used to create a series of samples with different amounts of crosslinking agent. These polymers show great promise for use in advanced batteries as cathode materials. Each system exhibits a glassy-state beta relaxation, with the intensity of this relaxation proportional to the crosslinking content. A dynamic glass transition is also observed for each system, and the glass transition temperature/segmental relaxation moves to higher temperatures with increased crosslink content as is typically observed in crosslinked systems. As is typical of polymers, ion motion in these systems is closely coupled to the backbone motion of the host polymer. National Research Council Postdoctoral Fellowship

  16. Characteristics of Sulfuric Acid Condensation on Cylinder Liners of Large Two-Stroke Marine Engines

    DEFF Research Database (Denmark)

    Cordtz, Rasmus Lage; Mayer, Stefan; Schramm, Jesper

    . Formation of corrosive sulfuric acid in the cylinder gas is modeled with a cali-brated engine model that incorporates a detailed sulfur reaction mechanism. Condensation of sulfuric acid follows the analogy between heat and mass transfer. Average bulk gas acid dew points are calculated by applying two......-phase thermochemistry of the binary H2O-H2SO4 system. Max dew points of typically more than 200 °C are modeled close to max pressure and variations in terms of operating conditions are not large. However small increments of the dew point provided by e.g. the residual gas fraction, operating pressure, sulfur content...

  17. Preliminary results of measurements of air pollution caused by sulfur compounds near the Polaniec power plant

    Energy Technology Data Exchange (ETDEWEB)

    Dziewanski, J; Kasina, S; Lewinska, J; Piorek, S

    1976-01-01

    In the past investigations of the negative impact of power stations on the natural environment have been restricted to measuring sulfur dioxide content in the air. A method of determining complex influence of sulfur compounds on the natural environment is proposed. The following indexes are used: content of sulfur dioxide in the air, dust content (determined by means of the West-Gaeke method), content of sulphate ions in precipitation and pH value of precipitation. Methods used to determine each of the indexes are described. Location of measuring stations in the area where the power station is being constructed is evaluated, taking into account prevailing wind direction and atmospheric conditions (15 measuring points out of which 10 stations measure sulfur content in precipitation and pH value of precipitation, and 5 stations measure the mean daily concentration of sulfur dioxide and dust content). Results are presented in 3 maps, 1 table and 2 pictures. Variations in sulfur dioxide content, dust content, and pH value of precipitation depending on direction of wind, atmospheric conditions and season are analyzed. The results of the investigation will be compared with results of investigations carried out when the power station is in operation. (15 refs.)

  18. Danburite decomposition by sulfuric acid

    International Nuclear Information System (INIS)

    Mirsaidov, U.; Mamatov, E.D.; Ashurov, N.A.

    2011-01-01

    Present article is devoted to decomposition of danburite of Ak-Arkhar Deposit of Tajikistan by sulfuric acid. The process of decomposition of danburite concentrate by sulfuric acid was studied. The chemical nature of decomposition process of boron containing ore was determined. The influence of temperature on the rate of extraction of boron and iron oxides was defined. The dependence of decomposition of boron and iron oxides on process duration, dosage of H 2 SO 4 , acid concentration and size of danburite particles was determined. The kinetics of danburite decomposition by sulfuric acid was studied as well. The apparent activation energy of the process of danburite decomposition by sulfuric acid was calculated. The flowsheet of danburite processing by sulfuric acid was elaborated.

  19. Effect of sulfur on the SCC and corrosion fatigue performance of stainless steel

    International Nuclear Information System (INIS)

    West, E.; Nolan, T.; Lucente, A.; Morton, D.; Lewis, N.; Morris, R.; Mullen, J.; Newsome, G.

    2015-01-01

    Stress corrosion cracking and corrosion fatigue experiments were conducted on model heats of 304/304L stainless steel with systematically controlled sulfur content to isolate the influence of sulfur on crack growth behavior. The results of the SCC experiments conducted in 338 C. degrees deaerated water on 20% cold worked model heats with 0.006 and 0.012 wt% sulfur showed an order of magnitude or more reduction in the crack growth rate relative to a model heat with <0.001 wt% sulfur. Corrosion fatigue crack growth rates revealed a reduction in the crack growth rates of the elevated sulfur heats relative to model predicted steady state crack growth rates with increasing rise time for nominal loading conditions of a stress ratio of 0.7 and a stress intensity factor range of 6.6 MPa√m. At the longest rise time of 5.330 sec, the corrosion fatigue crack growth rate of the 0.006 wt% sulfur model heat was only 13% of model predictions and the crack growth of the 0.012 wt% sulfur heat completely stalled. Experiments conducted in anion faulted aerated water on stainless steel heats with moderate to high sulfur and variable carbon and boron contents showed that any detrimental effect of sulfur in this environment was secondary to the effect of sensitization in promoting SCC growth. (authors)

  20. Stress Corrosion Cracking of Ni-base Alloys in Sulfur Containing Solutions at 340 .deg. C

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eun Hee; Hwang, Seong Sik; Kim, Dong Jin; Kim, Sung Woo [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    Sulfur has been identified as one of the major impurities introduced into the secondary water of pressurized water-reactors (PWRs). Sulfur can originate from various sources, such as resin sources, feed water, cooling water in-leakage, and condenser leaks. Many authors have investigated effects of reduced sulfur in a wide pH range with or without additives. The presence of reduced sulfur species on the surfaces of pulled tubes having stress corrosion cracking (SCC) was also identified. In present work, SCC tests were conducted to investigate effects of reduced sulfur species on the SCC behavior of Ni-base Alloys. The Alloy 690 TT showed the most SCC resistant, regardless of the sulfur species. The Cr content and heat treatments of alloys appeared the increase in the SCC resistance.

  1. New method for reduction of burning sulfur of coal

    International Nuclear Information System (INIS)

    Lyutskanov, L.; Dushanov, D.

    1998-01-01

    The coal pyrolysis is key phase in the the pyrolysis-combustion cycle as it provides char for combustor. The behaviour of sulfur compounds during coal pyrolysis depends on factors as rank of coal, quantity of sulfur and sulfur forms distribution in the coal, quantity and kind of mineral matter and the process conditions. The mineral content of coal may inhibit or catalyze the formation of volatile sulfur compounds. The pyrolysis itself is a mean of removing inorganic and organic sulfur but anyway a portion of it remains in the char while the other moves into the tar and gas. The aim of this study was to determine an optimal reduction of burning sulfur at the coal pyrolysis by varying parametric conditions. The pyrolysis of different kinds of coal has been studied. The samples with size particles o C at atmospheric pressure and with a heating rate of 6-50 o C min -1 . They were treated with exhaust gas and nitrogen at an addition of steam and air. The char obtained remains up to 10 min at the final temperature. The char samples cool without a contact with air. Two methods of desulfurization-pyrolysis were studied - using 9-vertical tubular reactor and 9-horizontal turning reactor. The results obtained show that at all samples there is a decrease of burning sulfur with maximal removal efficiency 83%. For example at a pyrolysis of Maritsa Iztok lignite coal the burning sulfur is only 16% in comparison with the control sample. The remained is 90% sulfate, 10% organic and pyrite traces when a mixture 'exhaust gas-water stream-air' was used. The method of desulfurization by pyrolysis could be applied at different kinds of coal and different conditions. Char obtained as a clean product can be used for generating electric power. This innovation is in a stage of patenting

  2. Ultra Low Sulfur Home Heating Oil Demonstration Project

    Energy Technology Data Exchange (ETDEWEB)

    Batey, John E. [Energy Research Center, Inc., Easton, CT (United States); McDonald, Roger [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-09-30

    This Ultra Low Sulfur (ULS) Home Heating Oil Demonstration Project was funded by the New York State Energy Research and Development Authority (NYSERDA) and has successfully quantified the environmental and economic benefits of switching to ULS (15 PPM sulfur) heating oil. It advances a prior field study of Low Sulfur (500 ppm sulfur) heating oil funded by NYSERDA and laboratory research conducted by Brookhaven National Laboratory (BNL) and Canadian researchers. The sulfur oxide and particulate matter (PM) emissions are greatly reduced as are boiler cleaning costs through extending cleaning intervals. Both the sulfur oxide and PM emission rates are directly related to the fuel oil sulfur content. The sulfur oxide and PM emission rates approach near-zero levels by switching heating equipment to ULS fuel oil, and these emissions become comparable to heating equipment fired by natural gas. This demonstration project included an in-depth review and analysis of service records for both the ULS and control groups to determine any difference in the service needs for the two groups. The detailed service records for both groups were collected and analyzed and the results were entered into two spreadsheets that enabled a quantitative side-by-side comparison of equipment service for the entire duration of the ULS test project. The service frequency for the ULS and control group were very similar and did indicate increased service frequency for the ULS group. In fact, the service frequency with the ULS group was slightly less (7.5 percent) than the control group. The only exception was that three burner fuel pump required replacement for the ULS group and none were required for the control group.

  3. Honeycomb-like Nitrogen and Sulfur Dual-Doped Hierarchical Porous Biomass-Derived Carbon for Lithium-Sulfur Batteries.

    Science.gov (United States)

    Chen, Manfang; Jiang, Shouxin; Huang, Cheng; Wang, Xianyou; Cai, Siyu; Xiang, Kaixiong; Zhang, Yapeng; Xue, Jiaxi

    2017-04-22

    Honeycomb-like nitrogen and sulfur dual-doped hierarchical porous biomass-derived carbon/sulfur composites (NSHPC/S) are successfully fabricated for high energy density lithium-sulfur batteries. The effects of nitrogen, sulfur dual-doping on the structures and properties of the NSHPC/S composites are investigated in detail by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and charge/discharge tests. The results show that N, S dual-doping not only introduces strong chemical adsorption and provides more active sites but also significantly enhances the electronic conductivity and hydrophilic properties of hierarchical porous biomass-derived carbon, thereby significantly enhancing the utilization of sulfur and immobilizing the notorious polysulfide shuttle effect. Especially, the as-synthesized NSHPC-7/S exhibits high initial discharge capacity of 1204 mA h g -1 at 1.0 C and large reversible capacity of 952 mA h g -1 after 300 cycles at 0.5 C with an ultralow capacity fading rate of 0.08 % per cycle even at high sulfur content (85 wt %) and high active material areal mass loading (2.8 mg cm -2 ) for the application of high energy density Li-S batteries. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Investigation of sulfur-polycyclic aromatic hydrocarbon in coal derived tars of pyrolysis and hydropyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Chen, H.; Li, B.; Zhang, B. [Chinese Academy of Sciences, Taiyuan (China). State Key Laboratory of Coal Conversion

    1999-07-01

    A study was undertaken to characterize sulphur forms in coal derived tars from pyrolysis and hydropyrolysis of bituminous coal and lignite. The pyrolysis tars were analyzed for content of polycyclic aromatic sulfur hydrocarbons (PASH). 5 refs., 3 figs., 3 tabs.

  5. Absence of respiratory inflammatory reaction of elemental sulfur using the California Pesticide Illness Database and a mouse model.

    Science.gov (United States)

    Lee, Kiyoung; Smith, Jodi L; Last, Jerold A

    2005-01-01

    Elemental sulfur, a natural substance, is used as a fungicide. Elemental sulfur is the most heavily used agricultural chemical in California. In 2003, annual sulfur usage in California was about 34% of the total weight of pesticide active ingredient used in production agriculture. Even though sulfur is mostly used in dust form, the respiratory health effects of elemental sulfur are not well documented. The purpose of this paper is to address the possible respiratory effect of elemental sulfur using the California Pesticide Illness Database and laboratory experiments with mice. We analyzed the California Pesticide Illness Database between 1991 and 2001. Among 127 reports of definite, probable, and possible illness involving sulfur, 21 cases (16%) were identified as respiratory related. A mouse model was used to examine whether there was an inflammatory or fibrotic response to elemental sulfur. Dust solutions were injected intratracheally into ovalbumin sensitized mice and lung damage was evaluated. Lung inflammatory response was analyzed via total lavage cell counts and differentials, and airway collagen content was analyzed histologically and biochemically. No significant differences from controls were seen in animals exposed to sulfur particles. The findings suggest that acute exposure of elemental sulfur itself may not cause an inflammatory reaction. However, further studies are needed to understand the possible health effects of chronic sulfur exposure and environmental weathering of sulfur dust.

  6. Demand outlook for sulfur and high-sulfur petroleum coke

    Energy Technology Data Exchange (ETDEWEB)

    Koshkarov, V.Ya.; Danil' yan, P.G.; Feotov, V.E.; Gimaev, R.N.; Koshkarova, M.E.; Sadykova, S.R.; Vodovichenko, N.S.

    1980-01-01

    The feasibility of using sulfur and high-sulfur petroleum coke fines in pyrometallurgical processes and also in the chemical and coal-tar chemical industry is examined. Results of industrial tests on briquetting fines of petroleum coke with a petroleum binder are presented. The feasibility of using the obtained briquets in shaft furnace smelting of oxidized nickel ores, production of anode stock, and also in the chemical industry are demonstrated.

  7. Sulfur equilibrium desulfurization of sulfur containing products of combustion

    International Nuclear Information System (INIS)

    Woodroffe, J.A.; Abichandani, J.S.

    1990-01-01

    This patent describes the method for the combustion of a carbon- and sulfur-containing fuel for substantially reducing emission of gaseous sulfur compounds formed during combustion of the fuel in a combustion zone. The zone having one or more fuel inlets and one or more oxidizer inlets, and having a combustion products outlet spaced therefrom, and having one or more inorganic sorbent inlets downstream of the fuel inlet(s) and oxidizer inlet(s) and upstream of the combustion products outlet

  8. Graphene-sulfur nanocomposites for rechargeable lithium-sulfur battery electrodes

    Science.gov (United States)

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

    2014-06-17

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

  9. Sulfur, selenium, tellurium and polonium

    International Nuclear Information System (INIS)

    Berry, F.J.

    1987-01-01

    This chapter on the coordination compounds of sulfur, selenium, tellurium and polonium starts with an introduction to the bonding, valence and geometry of the elements. Complexes of the group VIB elements are discussed with particular reference to the halo and pseudohalide complexes, oxo acid complexes, oxygen and nitrogen donor complexes and sulfur and selenium donor complexes. There is a section on the biological properties of the complexes discussed. (UK)

  10. New uses of sulfur - update

    Energy Technology Data Exchange (ETDEWEB)

    Almond, K.P.

    1995-07-01

    An update to an extensive bibliography on alternate uses of sulfur was presented. Alberta Sulphur Research Ltd., previously compiled a bibliography in volume 24 of this quarterly bulletin. This update provides an additional 44 new publications. The information regarding current research focusses on topics regarding the use of sulfur in oil and gas applications, mining and metallurgy, concretes and other structural materials, waste management, rubber and textile products, asphalts and other paving and highway applications.

  11. For sale: Sulfur emissions

    International Nuclear Information System (INIS)

    Heiderscheit, J.

    1992-01-01

    The allowance trading market has started a slow march to maturity. Competitive developers should understand the risks and opportunities now presented. The marketplace for sulfur dioxide (SO 2 ) emissions allowances - the centerpiece of Title 4's acid rain reduction program - remains enigmatic 19 months after the Clean Air Act amendments of 1990 were passed. Yet it is increasingly clear that the emission allowance market will likely confound the gloom and doom of its doubters. The recently-announced $10 million dollar Wisconsin Power and Light allowance sales to Duquesne Light and the Tennessee Valley Authority are among the latest indications of momentum toward a stabilizing market. This trend puts additional pressure on independent developers to finalize their allowance strategies. Developers who understand what the allowance trading program is and what it is not, know the key players, and grasp the unresolved regulatory issues will have a new competitive advantage. The topics addressed in this article include the allowance marketplace, marketplace characteristics, the regulatory front, forward-looking strategies, and increasing marketplace activity

  12. Porous-Shell Vanadium Nitride Nanobubbles with Ultrahigh Areal Sulfur Loading for High-Capacity and Long-Life Lithium-Sulfur Batteries.

    Science.gov (United States)

    Ma, Lianbo; Yuan, Hao; Zhang, Wenjun; Zhu, Guoyin; Wang, Yanrong; Hu, Yi; Zhao, Peiyang; Chen, Renpeng; Chen, Tao; Liu, Jie; Hu, Zheng; Jin, Zhong

    2017-12-13

    Lithium-sulfur (Li-S) batteries hold great promise for the applications of high energy density storage. However, the performances of Li-S batteries are restricted by the low electrical conductivity of sulfur and shuttle effect of intermediate polysulfides. Moreover, the areal loading weights of sulfur in previous studies are usually low (around 1-3 mg cm -2 ) and thus cannot fulfill the requirement for practical deployment. Herein, we report that porous-shell vanadium nitride nanobubbles (VN-NBs) can serve as an efficient sulfur host in Li-S batteries, exhibiting remarkable electrochemical performances even with ultrahigh areal sulfur loading weights (5.4-6.8 mg cm -2 ). The large inner space of VN-NBs can afford a high sulfur content and accommodate the volume expansion, and the high electrical conductivity of VN-NBs ensures the effective utilization and fast redox kinetics of polysulfides. Moreover, VN-NBs present strong chemical affinity/adsorption with polysulfides and thus can efficiently suppress the shuttle effect via both capillary confinement and chemical binding, and promote the fast conversion of polysulfides. Benefiting from the above merits, the Li-S batteries based on sulfur-filled VN-NBs cathodes with 5.4 mg cm -2 sulfur exhibit impressively high areal/specific capacity (5.81 mAh cm -2 ), superior rate capability (632 mAh g -1 at 5.0 C), and long cycling stability.

  13. Influence of sulfur, phosphorus, and antimony segregation on the intergranular hydrogen embrittlement of nickel

    International Nuclear Information System (INIS)

    Bruemmer, S.M.; Baer, D.R.; Jones, R.H.; Thomas, M.T.

    1983-01-01

    The effectiveness of sulfur, phosphorus, and antimony in promoting the intergranular embrittlement of nickel was investigated using straining electrode tests in 1N H 2 SO 4 at cathodic potentials. Sulfur was found to be the critical grain boundary segregant due to its large enrichment at grain boundaries (10 4 to 10 5 times the bulk content) and the direct relationship between sulfur coverage and hydrogeninduced intergranular failure. Phosphorus was shown to be significantly less effective than sulfur or antimony in inducing the intergranular hydrogen embrittlement of nickel. The addition of phosphoru to nickel reduced the tendency for intergranular fracture and improved ductility because phosphoru segregated strongly to grain interfaces and limited sulfur enrichment. The hydrogen embrittling potency of antimony was also less than that of sulfur while its segregation propensity was considerably less. It was found that the effectiveness of segregated phosphorus and antimony in prompting inter granular embrittlement vs that of sulfur could be expressed in terms of an equivalent grain boundary sulfur coverage. The relative hydrogen embrittling potencies of sulfur, phosphorus, and antimony are discussed in reference to general mechanisms for the effect of impurity segregation on hydrogeninduced intergranular fracture

  14. Transfer characterization of sulfur from coal-burning emission to plant leaves by PIXE and XANES

    Energy Technology Data Exchange (ETDEWEB)

    Bao, L.M.; Zhang, G.L.; Zhang, Y.X.; Li, Y.; Lin, J.; Liu, W.; Cao, Q.C.; Zhao, Y.D.; Ma, C.Y.; Han, Y. [Chinese Academy of Sciences, Shanghai (China). Shanghai Institute of Applied Physics

    2009-11-15

    The impact of coal-burning emission on sulfur in camphor leaves was investigated using Proton Induced X-ray Emission (PIXE) and synchrotron radiation technique X-ray Absorption Near-Edge Structure (XANES) spectroscopy. The PIXE results show that the sulfur concentrations in the leaves collected at the polluted site are significantly higher than those in controls. The sulfur XANES spectra show the presence of organic (disulfides, thiols, thioethers, sulfonates and sulfoxides) and inorganic sulfur (sulfates) in the leaves. The inorganic sulfur in the leaves of camphor tree polluted by coal combustion is 15% more than that of the control site. The results suggest that the long-term coal-burning pollution resulted in an enhanced content of the total sulfur and sulfate in the leaves, and the uptake of sulfur by leaves had exceeded the metabolic requirement of plants and the excess of sulfur was stored as SO{sub 4}2{sup -}. It can monitor the sulfur pollution in atmosphere.

  15. A XANES Study of Sulfur Speciation and Reactivity in Cokes for Anodes Used in Aluminum Production

    Science.gov (United States)

    Jahrsengene, Gøril; Wells, Hannah C.; Rørvik, Stein; Ratvik, Arne Petter; Haverkamp, Richard G.; Svensson, Ann Mari

    2018-06-01

    Availability of anode raw materials in the growing aluminum industry results in a wider range of petroleum cokes being used to produce carbon anodes. The boundary between anode grade cokes and what previously was considered non-anode grades are no longer as distinct as before, leading to introduction of cokes with higher sulfur and higher trace metal impurity content in anode manufacturing. In this work, the chemical nature of sulfur in five industrial cokes, ranging from 1.42 to 5.54 wt pct S, was investigated with K-edge XANES, while the reactivity of the cokes towards CO2 was measured by a standard mass loss test. XANES identified most of the sulfur as organic sulfur compounds. In addition, a significant amount is identified (16 to 53 pct) as S-S bound sulfur. A strong inverse correlation is observed between CO2-reactivity and S-S bound sulfur in the cokes, indicating that the reduction in reactivity is more dependent on the amount of this type of sulfur compound rather than the total amount of sulfur or the amount of organic sulfur.

  16. Comparison of comprehensive two-dimensional gas chromatography coupled with sulfur-chemiluminescence detector to standard methods for speciation of sulfur-containing compounds in middle distillates.

    Science.gov (United States)

    Ruiz-Guerrero, Rosario; Vendeuvre, Colombe; Thiébaut, Didier; Bertoncini, Fabrice; Espinat, Didier

    2006-10-01

    The monitoring of total sulfur content and speciation of individual sulfur-containing compounds in middle distillates is required for efficient catalyst selection and for a better understanding of the kinetics of the reactions involved in hydrotreament processes. Owing to higher resolution power and enhanced sensitivity, comprehensive two-dimensional gas chromatography (GCxGC) hyphenated to sulfur chemiluminescence detection (SCD) has recently evolved as a powerful tool for improving characterization and identification of sulfur compounds. The aim of this paper is to compare quantitatively GCxGC-SCD and various other methods commonly employed in the petroleum industry, such as X-ray fluorescence, conventional GC-SCD, and high-resolution mass spectrometry, for total sulfur content determination and speciation analysis. Different samples of middle distillates have been analyzed to demonstrate the high potential and important advantages of GCxGC-SCD for innovative and quantitative analysis of sulfur-containing compounds. More accurate and detailed results for benzothiophenes and dibenzothiophenes are presented, showing that GCxGC-SCD should become, in the future, an essential tool for sulfur speciation analysis.

  17. Anaerobic Copper Toxicity and Iron-Sulfur Cluster Biogenesis in Escherichia coli.

    Science.gov (United States)

    Tan, Guoqiang; Yang, Jing; Li, Tang; Zhao, Jin; Sun, Shujuan; Li, Xiaokang; Lin, Chuxian; Li, Jianghui; Zhou, Huaibin; Lyu, Jianxin; Ding, Huangen

    2017-08-15

    While copper is an essential trace element in biology, pollution of groundwater from copper has become a threat to all living organisms. Cellular mechanisms underlying copper toxicity, however, are still not fully understood. Previous studies have shown that iron-sulfur proteins are among the primary targets of copper toxicity in Escherichia coli under aerobic conditions. Here, we report that, under anaerobic conditions, iron-sulfur proteins in E. coli cells are even more susceptible to copper in medium. Whereas addition of 0.2 mM copper(II) chloride to LB (Luria-Bertani) medium has very little or no effect on iron-sulfur proteins in wild-type E. coli cells under aerobic conditions, the same copper treatment largely inactivates iron-sulfur proteins by blocking iron-sulfur cluster biogenesis in the cells under anaerobic conditions. Importantly, proteins that do not have iron-sulfur clusters (e.g., fumarase C and cysteine desulfurase) in E. coli cells are not significantly affected by copper treatment under aerobic or anaerobic conditions, indicating that copper may specifically target iron-sulfur proteins in cells. Additional studies revealed that E. coli cells accumulate more intracellular copper under anaerobic conditions than under aerobic conditions and that the elevated copper content binds to the iron-sulfur cluster assembly proteins IscU and IscA, which effectively inhibits iron-sulfur cluster biogenesis. The results suggest that the copper-mediated inhibition of iron-sulfur proteins does not require oxygen and that iron-sulfur cluster biogenesis is the primary target of anaerobic copper toxicity in cells. IMPORTANCE Copper contamination in groundwater has become a threat to all living organisms. However, cellular mechanisms underlying copper toxicity have not been fully understood up to now. The work described here reveals that iron-sulfur proteins in Escherichia coli cells are much more susceptible to copper in medium under anaerobic conditions than they

  18. Effect of Water Stress and Sulfur Fertilizer on Grain Yield, Chlorophyll and Nutrient Status of Black Cumin (Nigella Sativa L.

    Directory of Open Access Journals (Sweden)

    M. Heidari

    2011-04-01

    Full Text Available In order to study the effects of water stress and different amounts of sulfur fertilizer on grain yield, nutrient status and chlorophyll content in black cumin (Nigella sativa L. a field experiment as split plot design with three replications was conducted at Ghaen city in 2009. Treatments included three levels of irrigation after 50, 100 and 150 mm evaporation from Class A pan as main plot and four levels of sulfur fertilizer including 0, 75, 150 and 225 kg/ha from bentonite-sulfur source as sub-plot. Statistical analysis of the results showed that water stress has significant effect on grain yield and essential oil of black cumin. At the level of 150 mm evaporation from Class A pan, the grain yield decreased by 22.8% and essential oil by 27.6%. Application of 225 kg/ha sulfur fertilizer increased grain yield up to 7.2%. Water stress and sulfur fertilizer treatments had only significant effect on chlorophyll a content. However, water stress decreased chlorophyll a content, but sulfur fertilizer application up to 225 kg/ha increased the content of chlorophyll a. In this study, water stress decreased potassium content in black cumin leaves, but increased the sodium and calcium accumulation. Although application of sulfur fertilizer affected significantly the potassium and magnesium contents in shoots, but did not have significant effect on sodium and calcium contents.

  19. [Quality changes in Gastrodia Rhizoma of different origins and forms before and after sulfur fumigation].

    Science.gov (United States)

    Kang, Chuan-Zhi; Yang, Wan-Zhen; Zhou, Li; Jiang, Jing-Yi; Lv, Chao-Geng; Wang, Sheng; Zhou, Tao; Yang, Ye; Huang, Lu-Qi; Guo, Lan-Ping

    2018-01-01

    As Gastrodiae Rhizoma (GR) is one of the herbs more seriously affected by sulfur fumigation, so its quality has been always of a great concern. In this paper, GR samples collected from eight main producing areas and in three forms were fumigated with sulfur and quantitatively and qualitatively analyzed based on UPLC-Q-TOF-MS/MS. The results showed that the contents of gastrodin, parishin, parishin B and parishin C were decreased, while the content of parishin E was increased after sulfur fumigation treatment. Besides, a new sulfur marker named p-hydroxybenzyl hydrogen sulfite was produced in sulfur-fumigated GR samples. As compared with producing origins, forms had a greater impact on the quality of GR, especially in Hongtianma and Wutianma. Besides, the contents of gastrodins and parishins in Hongtianma from Jilin were lowest as compared with those in other producing areas. This might be correlated with planting patterns and environmental factors. In conclusion, sulfur fumigation has a more obvious impact on the quality of GR than origins and forms, which is attributed to the generation of new sulfur fumigated markers. Copyright© by the Chinese Pharmaceutical Association.

  20. Zinc-aluminates for an in situ sulfur reduction in cracked gasoline

    Energy Technology Data Exchange (ETDEWEB)

    Quintana-Solorzano, R.; Valente, J.S.; Hernandez-Beltran, F.J.; Castillo-Araiza, C.O. [Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas Norte 152 C.P., 07730 Mexico, D.F. (Mexico)

    2008-05-30

    Using additives remains as an attractive alternative for an in situ sulfur reduction in cracked gasoline since it is a practical, flexible and economical option. Zinc-aluminates prepared by the sol-gel method are used as additives for reducing sulfur in gasoline from the cracking of a high-sulfur feed in a fixed-bed bench reactor. Products distribution and feed conversion are not dramatically altered after incorporating the additive to the base catalyst with some effect on gasoline and its octane number and coke. A decrease in the gasoline sulfur content of up to 35 wt% including benzothiophene, and up to 50% excluding benzothiophene, is observed when blending the zinc-aluminates to the base catalyst, which is caused by lowering the C{sub 1} to C{sub 4} alkyl-thiophenes content. The zinc content of the zinc-aluminates has a positive effect on the gasoline sulfur reduction. It is suggested that together with the direct cracking of adsorbed thiophenic species on the additive, a further gasoline sulfur decrease is possible through cracking of saturated thiophenic species formed by hydrogenation of adsorbed thiophenic species with hydrogen produced in situ in the additive. The obtained results also demonstrate that solids with higher Lewis acidity are not unfailingly the most effective for gasoline sulfur reduction. (author)

  1. Biogenic sulfur compounds and the global sulfur cycle

    International Nuclear Information System (INIS)

    Aneja, V.P.; Aneja, A.P.; Adams, D.F.

    1982-01-01

    Field measurements of biogenic sulfur compounds shows a great variation in concentrations and emission rates for H 2 S, DMS, CS 2 and COS. Measurements by the chamber method and estimates from micrometeorological sampling are employed to determine the earth-atmosphere flux of these gases. Much of the variation can be attributed to differences of climate and surface conditions, with marshes being a large source of biogenic sulfur (mean contribution 4 x 10 to the 6th ton/year maximum contribution 142 x 10 to the 6th ton/year). Considering that the estimated biogenic contribution needed to balance the global sulfur cycle ranges from 40- 230 x 10 to the 6th tons/year, the mean values are not sufficient to balance this cycle. Further experimental investigations are suggested in order to characterize the biogenic processes adequately

  2. Effect of Prussian blue on organic sulfur of coal in aqueous medium

    Energy Technology Data Exchange (ETDEWEB)

    Demirbas, A. [Selcuk University, Konya (Turkey). Dept. of Chemical Engineering

    2007-01-15

    This study is an attempt to desulfurize organic sulfur from coal samples with ferric hexacyanoferrate (II), Fe{sub 4} (Fe(CN){sub 6}), as the desulfurization agent. Effect of temperature, particle size and concentration of ferrocyanide ion on desulfurization from the coal samples has been investigated. The temperature and stirring time are the most important parameters for the level of desulfurization of organic sulfur. Removal of organic sulfur content increased continuously with increasing temperature from 298 to 368 K. The organic sulfur removal rate sharply increases from 10 min to 30 min stirring time. After 30 min, it reaches a value of plateau. Particle size between -100 mesh and -200 mesh slightly affects the amount of organic sulfur removal. Gradual increase in the concentration of ferric hexacyanoferrate (II) raised the magnitude of desulfurization, but at higher concentration, the variation is not significant.

  3. Ultrasound-assisted oxidative process for sulfur removal from petroleum product feedstock.

    Science.gov (United States)

    Mello, Paola de A; Duarte, Fábio A; Nunes, Matheus A G; Alencar, Mauricio S; Moreira, Elizabeth M; Korn, Mauro; Dressler, Valderi L; Flores, Erico M M

    2009-08-01

    A procedure using ultrasonic irradiation is proposed for sulfur removal of a petroleum product feedstock. The procedure involves the combination of a peroxyacid and ultrasound-assisted treatment in order to comply with the required sulfur content recommended by the current regulations for fuels. The ultrasound-assisted oxidative desulfurization (UAOD) process was applied to a petroleum product feedstock using dibenzothiophene as a model sulfur compound. The influence of ultrasonic irradiation time, oxidizing reagents amount, kind of solvent for the extraction step and kind of organic acid were investigated. The use of ultrasonic irradiation allowed higher efficiency for sulfur removal in comparison to experiments performed without its application, under the same reactional conditions. Using the optimized conditions for UAOD, the sulfur removal was about 95% after 9min of ultrasonic irradiation (20kHz, 750W, run at 40%), using hydrogen peroxide and acetic acid, followed by extraction with methanol.

  4. Modeling the Distribution of Sulfur Compounds in a Large Two Stroke Diesel Engine

    DEFF Research Database (Denmark)

    Cordtz, Rasmus Lage; Schramm, Jesper; Andreasen, Anders

    2013-01-01

    In many years large low speed marine diesel engines have consumed heavy fuel oils with sulfur contents in the order of 2.5 - 4.5wt%. Present legislations require that the fuel sulfur is reduced and in near future the limit will be 0.5wt% globally. During combustion most of the sulfur is oxidized...... conditions and sulfur feed. This work presents a computational model of a large low speed two-stroke diesel engine where a 0D multi-zone approach including a detailed reaction mechanism is employed in order to investigate in cylinder formation of gaseous SO3 where fuel injection rates are determined using...... experimental pressure traces. Similarly to NO the SO3 is very sensitive to the rate that fresh air mixes with hot combustion products. Therefore a simple mixing rate is proposed and calibrated in order to meet experimental results of NO. Generally 3 - 5 % of the injected sulfur is oxidized to SO3...

  5. Synthesis of hierarchical porous honeycomb carbon for lithium-sulfur battery cathode with high rate capability and long cycling stability

    International Nuclear Information System (INIS)

    Qu, Yaohui; Zhang, Zhian; Zhang, Xiahui; Ren, Guodong; Wang, Xiwen; Lai, Yanqing; Liu, Yexiang; Li, Jie

    2014-01-01

    Highlights: • A novel HPHC was prepared by a simple template process. • The HPHC as matrix to load sulfur for Lithium-Sulfur battery cathodes. • S-HPHC cathode shows high rate capability and long cycling stability. • The sulfur-HPHC composite presents electrochemical stability up to 300 cycles at 1.5 C. - Abstract: Sulfur has a high specific capacity of 1675 mAh g −1 as lithium battery cathode, but its rapid capacity fading due to polysulfides dissolution presents a significant challenge for practical applications. Here we report a novel hierarchical porous honeycomb carbon (HPHC) for lithium-sulfur battery cathode with effective trapping of polysulfides. The HPHC was prepared by a simple template process, and a sulfur-carbon composite based on HPHC was synthesized for lithium-sulfur batteries by a melt-diffusion method. It is found that the elemental sulfur was dispersed inside the three-dimensionally hierarchical pores of HPHC based on the analyses. Electrochemical tests reveal that the sulfur-HPHC composite shows high rate capability and long cycling stability as cathode materials. The sulfur-HPHC composite with sulfur content of 66.3 wt% displays an initial discharge capacity of 923 mAh g −1 and a reversible discharge capacity of 564 mAh g −1 after 100 cycles at 2 C charge-discharge rate. In particular, the sulfur-HPHC composite presents a long term cycling stability up to 300 cycles at 1.5 C. The results illustrate that the electrochemical reaction constrained inside the interconnected macro/meso/micropores of HPHC would be the dominant factor for the excellent high rate capability and long cycling stability of the sulfur cathode, and the three-dimensionally honeycomb carbon network would be a promising carbon matrix structure for lithium-sulfur battery cathode

  6. Biogeochemistry of sulfur and iron in Thioploca-colonized surface sediments in the upwelling area off central Chile

    DEFF Research Database (Denmark)

    Zopfi, Jakob; Michael E., Böttcher; Jørgensen, Bo Barker

    2008-01-01

    suggest further that pyritization at depth includes light sulfide, potentially originating from bacterial sulfur disproportionation. The δ34S-values of pyrite down to -38‰ vs. V-CDT are among the lightest found in organic-rich marine sediments. Seasonal variations in the sulfur isotope composition...... of dissolved sulfate indicated a dynamic non-steady-state sulfur cycle in the surface sediments. The 18O content of porewater sulfate increased with depth at all sites compared to the bottom water composition due to intracellular isotope exchange reactions during microbial sulfur transformations....

  7. Production of petroleum bitumen by oxidation of heavy oil residue with sulfur

    Science.gov (United States)

    Tileuberdi, Ye.; Akkazyn, Ye. A.; Ongarbayev, Ye. K.; Imanbayev, Ye. I.; Mansurov, Z. A.

    2018-03-01

    In this paper production of bitumen adding elemental sulfur at oxidation of oil residue are investigated. The objects of research were distilled residue of Karazhanbas crude oil and elemental sulfur. These oil residue characterized by a low output of easy fractions and the high content of tar-asphaltene substances, therefore is the most comprehensible feedstock for producing bitumen. The sulfur is one of the oil product collected in oil extraction regions. Oxidation process of hydrocarbons carried out at temperatures from 180 up to 210 °С without addition of sulfur and with the addition of sulfur (5-10 wt. %) for 4 hours. At 200 °С oxidation of hydrocarbons with 5, 7 and 10 wt.% sulfur within 3-4 h allows receiving paving bitumen on the mark BND 200/300, BND 130/200, BN 90/130 and BN 70/30. Physical and mechanical characteristics of oxidation products with the addition of 5-7 wt. % sulfur corresponds to grade of paving bitumen BND 40/60. At the given temperature oxidized for 2.5-3 h, addition of 10 wt. % sulfur gave the products of oxidation describing on parameters of construction grades of bitumen (BN 90/10).

  8. Sulfur isotope signatures in New Zealand

    International Nuclear Information System (INIS)

    Cainey, J.

    2001-01-01

    The role of sulfur in cloud formation makes it a crucial ingredient in the global climate change debate. So it is important to be able to measure sulfur in the atmosphere and identify where it came from. (author)

  9. Model Prebiotic Iron-Sulfur Peptides

    Science.gov (United States)

    Bonfio, C.; Scintilla, S.; Shah, S.; Evans, D. J.; Jin, L.; Szostak, J. W.; Sasselov, D. D.; Sutherland, J. D.; Mansy, S. S.

    2017-07-01

    Iron-sulfur clusters form easily in aqueous solution in the presence of thiolates and iron ions. Polymerization of short, iron-sulfur binding tripeptide sequences leads to ferredoxin-like ligand spacing and activity.

  10. Ice nucleation in sulfuric acid/organic aerosols: implications for cirrus cloud formation

    Directory of Open Access Journals (Sweden)

    M. R. Beaver

    2006-01-01

    Full Text Available Using an aerosol flow tube apparatus, we have studied the effects of aliphatic aldehydes (C3 to C10 and ketones (C3 and C9 on ice nucleation in sulfuric acid aerosols. Mixed aerosols were prepared by combining an organic vapor flow with a flow of sulfuric acid aerosols over a small mixing time (~60 s at room temperature. No acid-catalyzed reactions were observed under these conditions, and physical uptake was responsible for the organic content of the sulfuric acid aerosols. In these experiments, aerosol organic content, determined by a Mie scattering analysis, was found to vary with the partial pressure of organic, the flow tube temperature, and the identity of the organic compound. The physical properties of the organic compounds (primarily the solubility and melting point were found to play a dominant role in determining the inferred mode of nucleation (homogenous or heterogeneous and the specific freezing temperatures observed. Overall, very soluble, low-melting organics, such as acetone and propanal, caused a decrease in aerosol ice nucleation temperatures when compared with aqueous sulfuric acid aerosol. In contrast, sulfuric acid particles exposed to organic compounds of eight carbons and greater, of much lower solubility and higher melting temperatures, nucleate ice at temperatures above aqueous sulfuric acid aerosols. Organic compounds of intermediate carbon chain length, C4-C7, (of intermediate solubility and melting temperatures nucleated ice at the same temperature as aqueous sulfuric acid aerosols. Interpretations and implications of these results for cirrus cloud formation are discussed.

  11. Experimental study of desulfurization of Zhong Liang Shau high sulfur coal by flotation

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Z.; Huang, B.; Cao, J. [China University of Mining and Technology (China). Beijing Graduate School

    1994-12-01

    Emission of large amount of SO{sub 2} from combustion of high sulfur coal causes serious environmental pollution. Pre-combustion desulfurization of high sulfur coal has become a necessity. This paper reports test results of fine coal desulfurization with different flotation technology and the effect of pyrite depressant. Test work showed that when the coal sample from Zhong Liang Shau was processed with a Free Jet Flotation Column 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{sub ds} for comprehensive evaluation of desulfurization process is proposed, which is defined as the product of the ratio of sulfur content reduction of clean coal and the recovery of combustible matters. 6 refs., 4 figs., 3 tabs.

  12. Diesel Emission Control -- Sulfur Effects (DECSE) Program; Phase I Interim Data Report No. 1

    Energy Technology Data Exchange (ETDEWEB)

    DOE; ORNL; NREL; EMA; MECA

    1999-08-15

    The Diesel Emission Control-Sulfur Effects (DECSE) is a joint government/industry program to determine the impact of diesel fuel sulfur levels on emission control systems whose use could lower emissions of nitrogen oxides (NO{sub x}) and particulate matter (PM) from on-highway trucks in the 2002--2004 model years. Phase 1 of the program was developed with the following objectives in mind: (1) evaluate the effects of varying the level of sulfur content in the fuel on the emission reduction performance of four emission control technologies; and (2) measure and compare the effects of up to 250 hours of aging on selected devices for multiple levels of fuel sulfur content. This interim data report summarizes results as of August, 1999, on the status of the test programs being conducted on three technologies: lean-NO{sub x} catalysts, diesel particulate filters and diesel oxidation catalysts.

  13. Sulfur compounds and species in Russian residues by XPS and PY-GC-PFPO

    Energy Technology Data Exchange (ETDEWEB)

    Quan, S.; Suoqi, Z.; Chunming, X. [University of Petroleum, State Key Laboraory of Heavy Oil Processing, Beijing (China); Kotlyar, L.; Kung, J. [National Research Council of Canada, Institute for Chemical processand Environmental Technology, Ottawa, ON (Canada); Chung, K. H. [Syncrude Canada Limited, Edmonton, AB (Canada)

    2004-07-01

    Distribution and structure of sulfur components of Russian crude oil were investigated by separating vacuum residues from the oil into 17 narrow cuts and one end-cut using the supercritical fluid extraction and fractionation technique (SFEF). The cuts were analyzed by gas chromatography, with conditions optimized from 600 degrees C to 1,000 degrees C, and between two and twenty seconds. In general, the total amount of of the sulfur compounds in pyrolizates was found to be proportional to the sulfur content in the vacuum residues. Thiophenes, benzothiophenes and dibenzothiophene content varied from vacuum residue to vacuum residue. Benzothiophens were identified as the dominant sulfur compounds in the pyrolizate of Russian crude oil.

  14. Studying sulfur functional groups in Norway spruce year rings using S L-edge total electron yield spectroscopy

    International Nuclear Information System (INIS)

    Struis, Rudolf P.W.J.; Ludwig, Christian; Barrelet, Timothee; Kraehenbuehl, Urs; Rennenberg, Heinz

    2008-01-01

    Profiles of the major sulfur functional groups in mature Norway spruce wood tissue have been established for the first time. The big challenge was the development of a method suitable for sulfur speciation in samples with very low sulfur content (< 100 ppm). This became possible by synchrotron X-ray absorption spectroscopy at the sulfur L-edge in total electron yield (TEY) detection mode with thin gold-coated wood slices. Functional groups were identified using sulfur compound spectra as fingerprints. Latewood of single year rings revealed metabolic plausible sulfur forms, particularly inorganic sulfide, organic disulfide, methylthiol, and highly oxidized sulfur. Form-specific profiles with Norway spruces from three different Swiss forest sites revealed high, but hitherto little-noticed, sulfur intensities attributable to natural heartwood formation and a common, but physiologically unexpected maximum around year ring 1986 with trees from the industrialized Swiss Plateau. It is hypothesized whether it may have resulted from the huge reduction in sulfur emissions after 1980 due to Swiss policy. Comparison with total S content profiles from optical emission spectroscopy underlined the more accurate and temporally better resolved TEY data with single wood year rings and it opened novel insights into the wood cell chemistry

  15. Sulfurization of Dissolved Organic Matter Increases Hg-Sulfide-Dissolved Organic Matter Bioavailability to a Hg-Methylating Bacterium.

    Science.gov (United States)

    Graham, Andrew M; Cameron-Burr, Keaton T; Hajic, Hayley A; Lee, Connie; Msekela, Deborah; Gilmour, Cynthia C

    2017-08-15

    Reactions of dissolved organic matter (DOM) with aqueous sulfide (termed sulfurization) in anoxic environments can substantially increase DOM's reduced sulfur functional group content. Sulfurization may affect DOM-trace metal interactions, including complexation and metal-containing particle precipitation, aggregation, and dissolution. Using a diverse suite of DOM samples, we found that susceptibility to additional sulfur incorporation via reaction with aqueous sulfide increased with increasing DOM aromatic-, carbonyl-, and carboxyl-C content. The role of DOM sulfurization in enhancing Hg bioavailability for microbial methylation was evaluated under conditions typical of Hg methylation environments (μM sulfide concentrations and low Hg-to-DOM molar ratios). Under the conditions of predicted metacinnabar supersaturation, microbial Hg methylation increased with increasing DOM sulfurization, likely reflecting either effective inhibition of metacinnabar growth and aggregation or the formation of Hg(II)-DOM thiol complexes with high bioavailability. Remarkably, Hg methylation efficiencies with the most sulfurized DOM samples were similar (>85% of total Hg methylated) to that observed in the presence of l-cysteine, a ligand facilitating rapid Hg(II) biouptake and methylation. This suggests that complexes of Hg(II) with DOM thiols have similar bioavailability to Hg(II) complexes with low-molecular-weight thiols. Overall, our results are a demonstration of the importance of DOM sulfurization to trace metal and metalloid (especially mercury) fate in the environment. DOM sulfurization likely represents another link between anthropogenic sulfate enrichment and MeHg production in the environment.

  16. Determination of sulfur compounds in hydrotreated transformer base oil by potentiometric titration.

    Science.gov (United States)

    Chao, Qiu; Sheng, Han; Cheng, Xingguo; Ren, Tianhui

    2005-06-01

    A method was developed to analyze the distribution of sulfur compounds in model sulfur compounds by potentiometric titration, and applied to analyze hydrotreated transformer base oil. Model thioethers were oxidized to corresponding sulfoxides by tetrabutylammonium periodate and sodium metaperiodate, respectively, and the sulfoxides were titrated by perchloric acid titrant in acetic anhydride. The contents of aliphatic thioethers and total thioethers were then determined from that of sulfoxides in solution. The method was applied to determine the organic sulfur compounds in hydrotreated transformer base oil.

  17. Non-matrix corrected organic sulfur determination by energy dispersive X-ray spectroscopy for western Kentucky coals and residues

    International Nuclear Information System (INIS)

    Clark, C.P.; Freeman, G.B.; Hower, J.C.

    1984-01-01

    A method for non-matrix corrected organic sulfur analysis by energy dispersive X-ray spectroscopy has been developed using petroleum coke standards. Typically, electron beam microanalysis is a rapid, nondestructive analytical technique to quantitatively measure organic sulfur in coal. The results show good correlation to ASTM values for numerous well characterized coals with a wide range in total and pyritic sulfur content. This direct analysis is capable of reducing error commonly associated with the present ASTM method which relies on an indirect measure of organic sulfur by difference. The precision of the organic sulfur values determined in the present study is comparable to that obtained by ZAF matrix corrected microanalysis. The energy dispersive microanalysis is capable of measuring micro as well as bulk organic sulfur levels

  18. Sulfur Geochemistry of a Lacustrine Record from Taiwan Reveals Enhanced Marine Aerosol Input during the Early Holocene.

    Science.gov (United States)

    Ding, Xiaodong; Li, Dawei; Zheng, Liwei; Bao, Hongyan; Chen, Huei-Fen; Kao, Shuh-Ji

    2016-12-12

    Lacustrine record of marine aerosol input has rarely been documented. Here, we present the sulfur geochemistry during the last deglaciation and early Holocene of a sediment core retrieved from the Dongyuan Lake in southern Taiwan. An unusually high sulfur peak accompanying pyrite presence is observed at 10.5 ka BP. Such high sulfur content in lacustrine record is unusual. The δ 34 S of sulfur varied from +9.5 to + 17.1‰ with two significant positive shifts at 10.5 and 9.4 ka BP. The sources of sulfur and potential processes involving the sulfur isotope variation including bacterial sulfate reduction, volcanic emissions, in-catchment sulfide oxidation and marine aerosol input are discussed. Enhanced marine aerosol input is the most likely explanation for such sulfur peaks and δ 34 S shifts. The positive δ 34 S shifts appeared concurrently with the maximum landslide events over Taiwan resulted from enhanced typhoon activities. The synchronicity among records suggests that increased typhoon activities promoted sea spray, and consequently enhanced the marine aerosol input with 34 S-enriched sulfate. Our sulfur geochemistry data revealed sea spray history and marine influence onto terrestrial environment at coastal regions. Wider coverage of spatial-temporal lacustrine sulfur geochemistry record is needed to validate the applicability of sulfur proxy in paleoenvironmental research.

  19. Biologically removing sulfur from dilute gas flows

    Science.gov (United States)

    Ruitenberg, R.; Dijkman, H.; Buisman, C. J. N.

    1999-05-01

    A biological process has been developed to clean off-gases containing sulfur dioxide from industrial installations. The sulfur dioxide is converted into hydrogen sulfide, which can then be oxidized to elemental sulfur if not used on-site. The process produces no waste products that require disposal and has a low reagent consumption.

  20. Method of distillation of sulfurous bituminous shales

    Energy Technology Data Exchange (ETDEWEB)

    Hallback, A J.S.; Bergh, S V

    1918-04-22

    A method of distillation of sulfur-containing bituminous shales is characterized by passing the hot sulfur-containing and oil-containing gases and vapors formed during the distillation through burned shale containing iron oxide, so that when these gases and vapors are thereafter cooled they will be, as far as possible, free from sulfur compounds. The patent contains six more claims.

  1. 46 CFR 153.1046 - Sulfuric acid.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Sulfuric acid. 153.1046 Section 153.1046 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK....1046 Sulfuric acid. No person may liquefy frozen or congealed sulfuric acid other than by external tank...

  2. 21 CFR 582.1095 - Sulfuric acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sulfuric acid. 582.1095 Section 582.1095 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1095 Sulfuric acid. (a) Product. Sulfuric acid. (b) Conditions of use. This substance is generally...

  3. Radiation induced sulfur dioxide removal

    International Nuclear Information System (INIS)

    Chmielewski, A.G.

    2000-01-01

    The biggest source of air pollution is the combustion of fossil fuels, were pollutants such as particulate, sulfur dioxide (SO 2 ), nitrogen oxides (NO x ), and volatile organic compounds (VOC) are emitted. Among these pollutants, sulfur dioxide plays the main role in acidification of the environment. The mechanism of sulfur dioxide transformation in the environment is partly photochemical. This is not direct photooxidation, however, but oxidation through formed radicals. Heterogenic reactions play an important role in this transformation as well; therefore, observations from environmental chemistry can be used in air pollution control engineering. One of the most promising technologies for desulfurization of the flue gases (and simultaneous denitrification) is radiation technology with an electron accelerator application. Contrary to the nitrogen oxides (NO x ) removal processes, which is based on pure radiation induced reactions, sulfur dioxide removal depends on two pathways: a thermochemical reaction in the presence of ammonia/water vapor and a radiation set of radiochemical reactions. The mechanism of these reactions and the consequent technological parameters of the process are discussed in this paper. The industrial application of this radiation technology is being implemented in an industrial pilot plant operated by INCT at EPS Kaweczyn. A full-scale industrial plant is currently in operation in China, and two others are under development in Japan and Poland. (author)

  4. Improved method for minimizing sulfur loss in analysis of particulate organic sulfur.

    Science.gov (United States)

    Park, Ki-Tae; Lee, Kitack; Shin, Kyoungsoon; Jeong, Hae Jin; Kim, Kwang Young

    2014-02-04

    The global sulfur cycle depends primarily on the metabolism of marine microorganisms, which release sulfur gas into the atmosphere and thus affect the redistribution of sulfur globally as well as the earth's climate system. To better quantify sulfur release from the ocean, analysis of the production and distribution of organic sulfur in the ocean is necessary. This report describes a wet-based method for accurate analysis of particulate organic sulfur (POS) in the marine environment. The proposed method overcomes the considerable loss of sulfur (up to 80%) that occurs during analysis using conventional methods involving drying. Use of the wet-based POS extraction procedure in conjunction with a sensitive sulfur analyzer enabled accurate measurements of cellular POS. Data obtained using this method will enable accurate assessment of how rapidly sulfur can transfer among pools. Such information will improve understanding of the role of POS in the oceanic sulfur cycle.

  5. Determination of sulfur dioxide in wine using headspace gas chromatography and electron capture detection.

    Science.gov (United States)

    Aberl, A; Coelhan, M

    2013-01-01

    Sulfites are routinely added as preservatives and antioxidants in wine production. By law, the total sulfur dioxide content in wine is restricted and therefore must be monitored. Currently, the method of choice for determining the total content of sulfur dioxide in wine is the optimised Monier-Williams method, which is time consuming and laborious. The headspace gas chromatographic method described in this study offers a fast and reliable alternative method for the detection and quantification of the sulfur dioxide content in wine. The analysis was performed using an automatic headspace injection sampler, coupled with a gas chromatograph and an electron capture detector. The method is based on the formation of gaseous sulfur dioxide subsequent to acidification and heating of the sample. In addition to free sulfur dioxide, reversibly bound sulfur dioxide in carbonyl compounds, such as acetaldehyde, was also measured with this method. A total of 20 wine samples produced using diverse grape varieties and vintages of varied provenance were analysed using the new method. For reference and comparison purposes, 10 of the results obtained by the proposed method were compared with those acquired by the optimised Monier-Williams method. Overall, the results from the headspace analysis showed good correlation (R = 0.9985) when compared with the conventional method. This new method requires minimal sample preparation and is simple to perform, and the analysis can also be completed within a short period of time.

  6. Depositional environments inferred from variations of calcium carbonate, organic carbon, and sulfide sulfur: a core from southeastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Paropkari, A.L.; Iyer, S.D.; Chauhan, O.S.; PrakashBabu, C.

    Pleistocene has been inferred. The higher contents of organic carbon and sulfide sulfur and their negative relationship clearly establish the existence of a reducing environment below 65 cm subbottom depth. The occurrence of pyrite framboids and crystals...

  7. Antibotulinal efficacy of sulfur dioxide in meat.

    Science.gov (United States)

    Tompkin, R B; Christiansen, L N; Shaparis, A B

    1980-01-01

    The addition of sodium metabisulfite as a source of sulfur dioxide delayed botulinal outgrowth in perishable canned comminuted pork when it was temperature abused at 27 degree C. The degree of inhibition was directly related to the level of sulfur dioxide. Levels greater than 100 microgram of sulfur dioxide per g were necessary to achieve significant inhibition when a target level of 100 botulinal spores per g was used. Sodium nitrite partially reduced the efficacy of the sulfur dioxide. Sulfur dioxide offers a new option for the control of botulinal outgrowth in cured or noncured meat and poultry products. PMID:6996613

  8. Thermal stress analysis of sulfur deactivated solid oxide fuel cells

    Science.gov (United States)

    Zeng, Shumao; Parbey, Joseph; Yu, Guangsen; Xu, Min; Li, Tingshuai; Andersson, Martin

    2018-03-01

    Hydrogen sulfide in fuels can deactivate catalyst for solid oxide fuel cells, which has become one of the most critical challenges to stability. The reactions between sulfur and catalyst will cause phase changes, leading to increase in cell polarization and mechanical mismatch. A three-dimensional computational fluid dynamics (CFD) approach based on the finite element method (FEM) is thus used to investigate the polarization, temperature and thermal stress in a sulfur deactivated SOFC by coupling equations for gas-phase species, heat, momentum, ion and electron transport. The results indicate that sulfur in fuels can strongly affect the cell polarization and thermal stresses, which shows a sharp decrease in the vicinity of electrolyte when 10% nickel in the functional layer is poisoned, but they remain almost unchanged even when the poisoned Ni content was increased to 90%. This investigation is helpful to deeply understand the sulfur poisoning effects and also benefit the material design and optimization of electrode structure to enhance cell performance and lifetimes in various hydrocarbon fuels containing impurities.

  9. Exposure experiments of trees to sulfur dioxide gas. Part I

    Energy Technology Data Exchange (ETDEWEB)

    Otani, A.

    1974-12-01

    The effects of gaseous sulfur dioxide on trees were studied. Twenty species of plant seedlings (70 cm in height) including Cedrus deodara, Metasequoia glyptostroboides, Ginkgo biloba, Celmus parvifolia var. albo-marginata, Pinus thumbergii, P. densiflora, Cryptomeria japonica, and Quercus myrsinaefolia, were exposed in a room to gaseous sulfur dioxide at 0.8 ppm for 7.5 hr/day (from 9 am to 4:30 pm) for 24 days at a temperature of 20-35 deg C and RH of 55-75%. Visible damage to plants was lighter in C.j. and Chamae cyparis obtusa, more severe in P.t., G.b., and C.d. The damage appeared earlier in G.b., Cinnamomum camphona, and Ilex rotunda, and the change of early symptoms was smaller in P.t., C.j., and C.o. The leaves of the 4-5th positions from the sprout were apt to be damaged. Although the sulfur content of exposed leaves increased markedly, that in other parts did not increase. Because of the high concentration of the gas and the short period of exposure, the absorption of sulfur into leaves should have differed from the situation in fields where longer exposure to lower concentrations of the gas would be expected. 6 references.

  10. Removal of sulfur from process streams

    International Nuclear Information System (INIS)

    Brignac, D.G.

    1984-01-01

    A process wherein water is added to a non-reactive gas stream, preferably a hydrogen or hydrogen-containing gas stream, sufficient to raise the water level thereof to from about 0.2 percent to about 50 percent, based on the total volume of the process gas stream, and the said moist gas stream is contacted, at elevated temperature, with a particulate mass of a sulfur-bearing metal alumina spinel characterized by the formula MAl 2 O 4 , wherein M is chromium, iron, cobalt, nickel, copper, cadmium, mercury, or zinc to desorb sulfur thereon. In the sulfur sorption cycle, due to the simultaneous adsorption of water and sulfur, the useful life of the metal alumina spinel for sulfur adsorption can be extended, and the sorbent made more easily regenerable after contact with a sulfur-bearing gas stream, notably sulfur-bearing wet hydrogen or wet hydrogen-rich gas streams

  11. Characterization of desulfurization, denitrogenation and process sulfur transfer during hydropyrolysis of Chinese high sulfur coals

    Energy Technology Data Exchange (ETDEWEB)

    Sun Chenggong; Li Baoqing [Chinese Academy of Sciences, Taiyuan (China). State Key Lab. of Coal Conversion; Snape, C.E. [Strathclyde Univ., Glasgow (United Kingdom). Dept. of Pure and Applied Chemistry

    1997-12-31

    The process desulphurization and denitrogenation of Chinese high sulfur coals and the characteristics of sulfur transformation during non-catalytic hydropyrolysis were investigated by a 10 g fixed-bed reactor and a small-scaled reactor with online spectrometry respectively. It was indicated that more than 70% of the total sulfur of the two high sulfur coals and almost all pyritic sulfur are removed as H{sub 2}S, leaving the char and tar products with much less sulfur distribution. The liability of sulfur transformation to tar products is closely related to the thiophenic structure forms rather than sulfidic forms. At the same time, the formation of trace amount of sulfur dioxide indicates the presence of inherent sulfur oxidation reactions inside coal frame structures even under H{sub 2} pressure. (orig.)

  12. Volatile earliest Triassic sulfur cycle

    DEFF Research Database (Denmark)

    Schobben, Martin; Stebbins, Alan; Algeo, Thomas J.

    2017-01-01

    model experiment. Exposure of evaporite deposits having a high δ 34S may account for the source change, with a possible role for the Siberian Traps volcanism by magmatic remobilization of Cambrian rock salt. A high sulfur cycle turnover rate would have left the ocean system vulnerable to development......Marine biodiversity decreases and ecosystem destruction during the end-Permian mass extinction (EPME) have been linked to widespread marine euxinic conditions. Changes in the biogeochemical sulfur cycle, microbial sulfate reduction (MSR), and marine dissolved sulfate concentrations during...... fractionation and point to a more universal control, i.e., contemporaneous seawater sulfate concentration.The MSR-trend transfer function yielded estimates of seawater sulfate of 0.6-2.8mM for the latest Permian to earliest Triassic, suggesting a balanced oceanic S-cycle with equal S inputs and outputs...

  13. An investigation of sulfur concentrations in soils and pine needles in Bandelier National Monument, New Mexico

    International Nuclear Information System (INIS)

    Gladney, E.S.; Ferenbaugh, R.W.; Jones, E.A.; Bell, M.G.; Morgan, J.D.; Stallings, E.A.; Nelson, L.A.; Lundstrom, C.; Bowker, R.G.

    1993-03-01

    Sulfur measurements in different age groups of pinon pine needles and adjacent soil samples from ten sampling sites at Bandelier National Monument were determined using combustion elemental analysis and chromatographic techniques. The primary goal was to establish base-line levels for elemental sulfur in the Monument. Sulfur levels in foliage and soils were evaluated using analysis of variance techniques. Foliage sulfur concentrations differed significantly among the 10 sampling sites and among trees within sites; however, needles of different ages did not differ significantly in sulfur content. Average soil concentrations were very low, approximately 12% of the average needle concentrations. Soil sulfur concentrations also differed significantly among the 10 sampling sites and at different depths in the soil. No statistical differences were evident in soils sampled at the four compass points (N,S,E,W) around each tree. These differences imply that large numbers of samples are needed to identify small effects from anthropogenic inputs of sulfur into the system or that the effects must be large relative to the differences among sampling sites and individual trees in order to be detected

  14. An investigation of sulfur concentrations in soils and pine needles in Canyonlands National Park, Utah

    International Nuclear Information System (INIS)

    Gladney, E.S.; Ferenbaugh, R.W.; Jones, E.A.; Bell, M.G.; Morgan, J.D.; Nelson, L.A.; Lundstrom, C.; Bowker, R.G.

    1993-03-01

    Sulfur measurements in different age groups of pinon pine needles and adjacent soil samples from ten sampling sites at Canyonlands National Park were determined using combustion elemental analysis and chromatographic techniques. The primary goal was to establish base-line levels for elemental sulfur in the Park. Sulfur levels in foliage and soils were evaluated using analysis of variance techniques. No significant differences were found in foliage sulfur concentrations among the 10 sampling sites; however, trees within sites were significantly different. Needles of different ages did not differ significantly in sulfur content. Average soil concentrations were very low, approximately 4% of the average needle concentrations. Soil sulfur concentrations also differed significantly among the 10 sampling sites and at different depths in the soil. No statistical differences were evident in soils sampled at the four compass points (N,S,E,W) around each tree. These differences imply that large numbers of samples are needed to identify small effects from anthropogenic inputs of sulfur into the system, or that the effects must be large relative to the differences among sampling sites and individual trees in order to be detected

  15. Sulfur emission from Victorian brown coal under pyrolysis, oxy-fuel combustion and gasification conditions.

    Science.gov (United States)

    Chen, Luguang; Bhattacharya, Sankar

    2013-02-05

    Sulfur emission from a Victorian brown coal was quantitatively determined through controlled experiments in a continuously fed drop-tube furnace under three different atmospheres: pyrolysis, oxy-fuel combustion, and carbon dioxide gasification conditions. The species measured were H(2)S, SO(2), COS, CS(2), and more importantly SO(3). The temperature (873-1273 K) and gas environment effects on the sulfur species emission were investigated. The effect of residence time on the emission of those species was also assessed under oxy-fuel condition. The emission of the sulfur species depended on the reaction environment. H(2)S, SO(2), and CS(2) are the major species during pyrolysis, oxy-fuel, and gasification. Up to 10% of coal sulfur was found to be converted to SO(3) under oxy-fuel combustion, whereas SO(3) was undetectable during pyrolysis and gasification. The trend of the experimental results was qualitatively matched by thermodynamic predictions. The residence time had little effect on the release of those species. The release of sulfur oxides, in particular both SO(2) and SO(3), is considerably high during oxy-fuel combustion even though the sulfur content in Morwell coal is only 0.80%. Therefore, for Morwell coal utilization during oxy-fuel combustion, additional sulfur removal, or polishing systems will be required in order to avoid corrosion in the boiler and in the CO(2) separation units of the CO(2) capture systems.

  16. Distribution of sulfur and pyrite in coal seams from Kutai Basin (East Kalimantan, Indonesia): Implications for paleoenvironmental conditions

    Energy Technology Data Exchange (ETDEWEB)

    Widodo, Sri [Department of Mining Engineering, Moslem University of Indonesia, Jln. Urip Sumoharjo, Makassar (Indonesia); Oschmann, Wolfgang [Institute of Geosciece, J.W. Goethe-University, Altenhoeferallee 1, D-60438 Frankfurt a.M. (Germany); Bechtel, Achim; Sachsenhofer, Reinhard F. [Department of Applied Geoscience and Geophysics, University of Leoben, Peter-Tunner-Str.5, A-8700 Leoben (Austria); Anggayana, Komang [Department of Mining Engineering, Bandung Institute of Technology, Jln. Ganesa 10, I-40132 Bandung (Indonesia); Puettmann, Wilhelm [Institute of Atmospheric and Environmental Sciences, Dapartment of Analytical Enviromental Chemistry, J.W. Goethe-University, Altenhoeferallee 1, D-60438 Frankfurt a.M. (Germany)

    2010-03-01

    Thirteen Miocene coal samples from three active open pit and underground coal mines in the Kutai Basin (East Kalimantan, Indonesia) were collected. According to our microscopical and geochemical investigations, coal samples from Sebulu and Centra Busang coal mines yield high sulfur and pyrite contents as compared to the Embalut coal mine. The latter being characterized by very low sulfur (< 1%) and pyrite contents. The ash, mineral, total sulfur, iron (Fe) and pyrite contents of most of the coal samples from the Sebulu and Centra Busang coal mines are high and positively related in these samples. Low contents of ash, mineral, total sulfur, iron (Fe) and pyrite have been found only in sample TNT-32 from Centra Busang coal mine. Pyrite was the only sulfur form that we could recognize under reflected light microscope (oil immersion). Pyrite occurred in the coal as framboidal, euhedral, massive, anhedral and epigenetic pyrite in cleats/fractures. High concentration of pyrite argues for the availability of iron (Fe) in the coal samples. Most coal samples from the Embalut coal mine show lower sulfur (< 1 wt.%) and pyrite contents as found within Centra Busang and Sebulu coals. One exception is the coal sample KTD-38 from Embalut mine with total sulfur content of 1.41 wt.%. The rich ash, mineral, sulfur and pyrite contents of coals in the Kutai Basin (especially Centra Busang and Sebulu coals) can be related to the volcanic activity (Nyaan volcanic) during Tertiary whereby aeolian material was transported to the mire during or after the peatification process. Moreover, the adjacent early Tertiary deep marine sediment, mafic igneous rocks and melange in the center of Kalimantan Island might have provided mineral to the coal by uplift and erosion. The inorganic matter in the mire might also originate from the ground and surface water from the highland of central Kalimantan. (author)

  17. [Relativity among starch quantity, polysaccharides content and total alkaloid content of Dendrobium loddigesii].

    Science.gov (United States)

    Zhu, Hua; Teng, Jianbei; Cai, Yi; Liang, Jie; Zhu, Yilin; Wei, Tao

    2011-12-01

    To find out the relativity among starch quantity, polysaccharides content and total alkaloid content of Dendrobium loddigesii. Microscopy-counting process was applied to starch quantity statistics, sulfuric acid-anthrone colorimetry was used to assay polysaccharides content and bromocresol green colorimetry was used to assay alkaloid content. Pearson product moment correlation analysis, Kendall's rank correlation analysis and Spearman's concordance coefficient analysis were applied to study their relativity. Extremely significant positive correlation was found between starch quantity and polysaccharides content, and significant negative correlation between alkaloid content and starch quantity was discovered, as well was between alkaloid content and polysaccharides content.

  18. Sulfur isotope variability of oceanic DMSP generation and its contributions to marine biogenic sulfur emissions.

    Science.gov (United States)

    Oduro, Harry; Van Alstyne, Kathryn L; Farquhar, James

    2012-06-05

    Oceanic dimethylsulfoniopropionate (DMSP) is the precursor to dimethylsulfide (DMS), which plays a role in climate regulation through transformation to methanesulfonic acid (MSA) and non-seasalt sulfate (NSS-SO(4)(2-)) aerosols. Here, we report measurements of the abundance and sulfur isotope compositions of DMSP from one phytoplankton species (Prorocentrum minimum) and five intertidal macroalgal species (Ulva lactuca, Ulva linza, Ulvaria obscura, Ulva prolifera, and Polysiphonia hendryi) in marine waters. We show that the sulfur isotope compositions (δ(34)S) of DMSP are depleted in (34)S relative to the source seawater sulfate by ∼1-3‰ and are correlated with the observed intracellular content of methionine, suggesting a link to metabolic pathways of methionine production. We suggest that this variability of δ(34)S is transferred to atmospheric geochemical products of DMSP degradation (DMS, MSA, and NSS-SO(4)(2-)), carrying implications for the interpretation of variability in δ(34)S of MSA and NSS-SO(4)(2-) that links them to changes in growth conditions and populations of DMSP producers rather than to the contributions of DMS and non-DMS sources.

  19. Assessment of the risk of pollution by sulfur compounds and heavy metals in soils located in the proximity of a disused for 20 years sulfur mine (SE Poland).

    Science.gov (United States)

    Sołek-Podwika, Katarzyna; Ciarkowska, Krystyna; Kaleta, Dorota

    2016-09-15

    The study assessed the long-term effects of anthropogenic pressure of the sulfur industry on turf-covered soils located in the vicinity of the sulfur mine Grzybów. The study assumes that 20 years which elapsed since the end of the exploitation of sulfur is a period sufficiently long for the content of sulfur compounds in soils not to exceed the permissible level and that soil of the region can be classified as not contaminated. A part of the study involved identification of changes in the contents Stot. and SSO4(2-) in soils collected in the 1970s and early twenty-first century. It was also traced the relationship between the content of sulfur compounds and selected soil properties and estimated risk of soil environment pollution by heavy metals. Mean contents of trace elements studied amounted to 10.2-10.8 mg kg(-1) for Pb, 14.3-39.4 mg kg(-1) for Zn, 0.2-0.4 mg kg(-1) for Cd, 3.8-32.2 mg kg(-1) for Cr, 2.7-15.1 mg kg(-1) for Cu and 2.9-18.7 mg kg(-1) for Ni. Based on the results of SSO4(2-) content in soils collected at a distance of 1 km from the mine, it was found out that despite the passage of years, the amount of this type of sulfur still is increased and exceeds 0.14 g kg(-1). As the distance from the mine grew lower (from 0.017 to 0.03 g kg(-1)) average content of the sulfur form was observed. In the studied soil material we found generally positive, strong correlation between the Stot. and SSO4(2-) content and analyzed trace elements. The degree of contamination of examined soils with heavy metals was estimated on the basis of the integrated pollution index, which pointed to a moderate and low level of antropogenization of this area. In addition, the relationship between the determined characteristics of soils (Corg. contents, the fraction heavy metals confirms that the trace elements present in soils do not occur in mobile forms in the soil solution. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Sulfur rich microporous polymer enables rapid and efficient removal of mercury(II) from water.

    Science.gov (United States)

    Xu, Dan; Wu, Winston Duo; Qi, Hao-Jun; Yang, Rui-Xia; Deng, Wei-Qiao

    2018-04-01

    Design and synthesis of adsorbents for efficient decontamination of hazardous contaminants Hg 2+ from wastewater, based on a facile and economical strategy, is an attractive target. Here, a novel sulfur rich microporous polymer (sulfur content of 31.4 wt %) with high surface area as well as densely populated sulfur atom with fast accessibility was reported to remove mercury (II) from water. The as prepared polymer (SMP) exhibited high binding affinity, high adsorption capacities, rapid adsorption kinetics, and good recyclability for Hg 2+ . The adsorption capacity of SMP was 595.2 mg g -1 . Furthermore, SMP could reduce trace concentrations of Hg 2+ from 200 p. p. b. to a level below drinking water standards (2 p. p. b.) within 3 min. This work allows large-scale production of sulfur rich porous materials for the practical application in water treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Sulfur-containing components of gamma-irradiated garlic bulbs

    International Nuclear Information System (INIS)

    Joongho Kwon; Jonguck Choi; Hyungsik Yoon

    1989-01-01

    Sulfur-containing components associated with garlic flavors were investigated to determine the effect of γ-irradiation at 0.1Gy on the quality of garlic bulbs (Allium sativum L.) during storage at 3±1 0 C and 80±5% RH for 10 months. Irradiation treatment had no influence on the amount of total sulfur and thiosulfinate of stored garlic for 10 months, while the storage period brought about a significant reduction (P < 0.05) in the content of both components after the 6-8th month of storage compared with that at the beginning of storage period. The identity of irradiated alliin (S-allyl-L-cysteine sulfoxide) at sprout-inhibition dose was confirmed according to thin-layer chromatography, i.r. and NMR spectroscopy data. (author)

  2. Sulfur-containing components of gamma-irradiated garlic bulbs

    Science.gov (United States)

    Kwon, Joong-Ho; Choi, Jong-Uck; Yoon, Hyung-Sik

    Sulfur-containing components associated with garlic flavors were investigated to determine the effect of γ-irradiation at 0.1 kGy on the quality of garlic bulbs ( Allium sativum L.) during storage at 3±1°C and 80±5% RH for 10 months. Irradiation treatment had no influence on the amount of total sulfur and thiosulfinate of stored garlic for 10 months, while the storage period brought about a significant reduction ( P<0.05) in the content of both components after the 6-8th month of storage compared with that at the beginning of storage period. The identity of irradiated alliin ( S-allyl- L-cysteine sulfoxide) at sprout-inhibition dose was confirmed according to thin-layer chromatography, i.r. and NMR spectroscopy data.

  3. Sulfur-containing components of gamma-irradiated garlic bulbs

    Energy Technology Data Exchange (ETDEWEB)

    Joongho Kwon (Korea Advanced Energy Research Inst., Daeduk (Republic of Korea)); Jonguck Choi; Hyungsik Yoon (Kyungpook National Univ., Taegu (Republic of Korea))

    1989-01-01

    Sulfur-containing components associated with garlic flavors were investigated to determine the effect of {gamma}-irradiation at 0.1Gy on the quality of garlic bulbs (Allium sativum L.) during storage at 3{plus minus}1{sup 0}C and 80{plus minus}5% RH for 10 months. Irradiation treatment had no influence on the amount of total sulfur and thiosulfinate of stored garlic for 10 months, while the storage period brought about a significant reduction (P < 0.05) in the content of both components after the 6-8th month of storage compared with that at the beginning of storage period. The identity of irradiated alliin (S-allyl-L-cysteine sulfoxide) at sprout-inhibition dose was confirmed according to thin-layer chromatography, i.r. and NMR spectroscopy data. (author).

  4. A Sulfur Amino Acid–Free Meal Increases Plasma Lipids in Humans123

    OpenAIRE

    Park, Youngja; Le, Ngoc-Anh; Yu, Tianwei; Strobel, Fred; Gletsu-Miller, Nana; Accardi, Carolyn J.; Lee, Kichun S.; Wu, Shaoxiong; Ziegler, Thomas R.; Jones, Dean P.

    2011-01-01

    The content of sulfur amino acid (SAA) in a meal affects postprandial plasma cysteine concentrations and the redox potential of cysteine/cystine. Because such changes can affect enzyme, transporter, and receptor activities, meal content of SAA could have unrecognized effects on metabolism during the postprandial period. This pilot study used proton NMR (1H-NMR) spectroscopy of human plasma to test the hypothesis that dietary SAA content changes macronutrient metabolism. Healthy participants (...

  5. 21 CFR 184.1095 - Sulfuric acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sulfuric acid. 184.1095 Section 184.1095 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Substances Affirmed as GRAS § 184.1095 Sulfuric acid. (a) Sulfuric acid (H2SO4, CAS Reg. No. 7664-93-9), also...

  6. The significance of elemental sulfur dissolution in liquid electrolyte lithium sulfur batteries

    NARCIS (Netherlands)

    Harks, Peter Paul R.M.L.; Robledo, Carla B.; Verhallen, Tomas W.; Notten, Peter H.L.; Mulder, Fokko M.

    2017-01-01

    It is shown that the dissolution of elemental sulfur into, and its diffusion through, the electrolyte allows cycling of lithium–sulfur batteries in which the sulfur is initially far removed and electrically insulated from the current collector. These findings help to understand why liquid

  7. Biogeochemistry of sulfur and iron in Thioploca-colonized surface sediments in the upwelling area off central chile

    Science.gov (United States)

    Zopfi, Jakob; Böttcher, Michael E.; Jørgensen, Bo Barker

    2008-02-01

    The biogeochemistry of sedimentary sulfur was investigated on the continental shelf off central Chile at water depths between 24 and 88 m under partial influence of an oxygen minimum zone. Dissolved and solid iron and sulfur species, including the sulfur intermediates sulfite, thiosulfate, and elemental sulfur, were analyzed at high resolution in the top 20 cm. All stations were characterized by high rates of sulfate reduction, but only the sediments within the Bay of Concepción contained dissolved sulfide. Due to advection and/or in-situ reoxidation of sulfide, dissolved sulfate was close to bottom water values. Whereas the concentrations of sulfite and thiosulfate were mostly in the submicromolar range, elemental sulfur was by far the dominant sulfur intermediate. Although the large nitrate- and sulfur-storing bacteria Thioploca were abundant, the major part of S 0 was located extracellularly. The distribution of sulfur species and dissolved iron suggests the reaction of sulfide with FeOOH as an important pathway for sulfide oxidation and sulfur intermediate formation. This is in agreement with the sulfur isotope composition of co-existing elemental sulfur and iron monosulfides. In the Bay of Concepción, sulfur isotope data suggest that pyrite formation proceeds via the reaction of FeS with polysulfides or H 2S. At the shelf stations, on the other hand, pyrite was significantly depleted in 34S relative to its potential precursors FeS and S 0. Isotope mass balance considerations suggest further that pyritization at depth includes light sulfide, potentially originating from bacterial sulfur disproportionation. The δ 34S-values of pyrite down to -38‰ vs. V-CDT are among the lightest found in organic-rich marine sediments. Seasonal variations in the sulfur isotope composition of dissolved sulfate indicated a dynamic non-steady-state sulfur cycle in the surface sediments. The 18O content of porewater sulfate increased with depth at all sites compared to the

  8. Improved ozone resistance of styrene-butadiene rubber cured by a combination of sulfur and ionizing radiation

    International Nuclear Information System (INIS)

    Basfar, A.A.; Silverman, Joseph

    1995-01-01

    Fourier Transform Infrared (FTIR) studies performed in this work indicate that high ozone resistance of Styrene-Butadiene Rubber (SBR) formulations cured by a combination of sulfur and ionizing radiation is associated with unusually high vinyl concentration. On the other hand, sulfur cured SBR formulations with low vinyl concentration have poor ozone resistance. Curing with peroxides which involves chemistry similar to that of radiation curing, also leads to high vinyl concentration (relative to sulfur curing) and high ozone resistance. Increasing the absorbed dose in sulfur-radiation cured samples decreased the high vinyl content to a point where the ozone resistance declined greatly. Carbon black was shown to reduce the absorption of both the transvinylene and the vinyl unsaturation groups, but not to the same extent in all formulations. Also, the carbon black seems to play a greater role in the absorption of the unsaturation as sulfur increases. (Author)

  9. Improved ozone resistance of styrene-butadiene rubber cured by a combination of sulfur and ionizing radiation

    International Nuclear Information System (INIS)

    Basfar, A.A.; Silverman, J.

    1995-01-01

    Fourier Transform (FTIR) studies performed in this work indicate that high ozone resistance of Styrene-Butadiene Rubber (SBR) formulations cured by a combination of sulfur and ionizing radiation is associated with unusually high vinyl concentration. On the other hand, sulfur cured SBR formulations with low vinyl concentration have poor ozone resistance. Curing with peroxides which involves chemistry similar to that of radiation curing, also leads to high vinyl concentration (relative to sulfur curing) and high ozone resistance. Increasing the absorbed dose in sulfur-radiation cured samples decreased the high vinyl content to a point where the ozone resistance declined greatly. Carbon black was shown to reduce the absorption of both the transvinylene and the vinyl unsaturation groups, but not to the same extent in all formulations. Also, the carbon black seems to play a greater role in the absorption of the unsaturation as sulfur increases. (Author)

  10. Sulfur removal from fuel using zeolites/polyimide mixed matrix membrane adsorbents

    International Nuclear Information System (INIS)

    Lin, Ligang; Wang, Andong; Dong, Meimei; Zhang, Yuzhong; He, Benqiao; Li, Hong

    2012-01-01

    Graphical abstract: Membrane adsorption process is proposed for sulfur removal. Three-dimensional network structure is key to fulfill adsorption function of MMMs, which adsorption/desorption behavior is markedly related with binding force with sulfur molecules. Highlights: ► Membrane adsorption process is proposed for sulfur removal. ► Three-dimensional network structure of MMMs is key to fulfill adsorption function. ► Adsorption/desorption behavior is markedly related with binding force. - Abstract: A novel membrane adsorption process was proposed for the sulfur removal from fuels. The mixed matrix membranes (MMMs) adsorbents composed of polyimide (PI) and various Y zeolites were prepared. By the detailed characterization of FT-IR, morphology, thermal and mechanical properties of MMMs adsorbents, combining the adsorption and desorption behavior research, the process–structure–function relationship was discussed. Field-emission scanning electron microscope (FESEM) images show that the functional particles are incorporated into the three-dimensional network structure. MMMs adsorbents with 40% of zeolites content possess better physical properties, which was confirmed by mechanical strength and thermo stability analysis. Influence factors including post-treatment, content of incorporated zeolites, adsorption time, temperature, initial sulfur concentration as well as sulfur species on the adsorption performance of MMMs adsorbents have been evaluated. At 4 wt.% zeolites content, adsorption capacity for NaY/PI, AgY/PI and CeY/PI MMMs adsorbents come to 2.0, 7.5 and 7.9 mg S/g, respectively. And the regeneration results suggest that the corresponding spent membranes can recover about 98%, 90% and 70% of the desulfurization capacity, respectively. The distinct adsorption and desorption behavior of MMMs adsorbents with various functional zeolites was markedly related with their various binding force and binding mode with sulfur compounds.

  11. Lithium battery using sulfur infiltrated in three-dimensional flower-like hierarchical porous carbon electrode

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Noelia; Caballero, Alvaro [Dpto.Química Inorgánica, Instituto Universitario de Investigación en Química Fina y Nanoquímica, Universidad de Córdoba, Campus de Rabanales (Spain); Morales, Julián, E-mail: iq1mopaj@uco.es [Dpto.Química Inorgánica, Instituto Universitario de Investigación en Química Fina y Nanoquímica, Universidad de Córdoba, Campus de Rabanales (Spain); Agostini, Marco [Department of Chemistry, SapienzaUniversity, P.zzale Aldo Moro 5, 00185, Rome (Italy); Hassoun, Jusef, E-mail: jusef.hassoun@unife.it [Università di Ferrara, Dipartimento di Scienze Chimiche e Farmaceutiche, Via Fossato di Mortara 17, Ferrara (Italy)

    2016-09-01

    Three dimensional, flower-like hierarchical porous carbon (FPC) and its CO{sub 2}-activation (AFPC) are reported as sulfur-hosting matrixes in Li/S battery. The composites are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen adsorption-desorption isotherms as well as by galvanostatic cycling and electrochemical impedance spectroscopy (EIS) in lithium-cell. Both samples show well defined micrometric morphology and a sulfur content as high as 66% expected to reflect into rather high practical energy density of the electrode in lithium-sulfur battery. The lithium sulfur cell using the FPC-S composite exhibits at 25 °C a moderate cycling stability with delivered capacity ranging from 1000 to about 610 mAh g{sup −1} upon 50 cycles at 100 mA g{sup −1}. The AFPC-S composite reveals increased cycling stability and delivers a capacity ranging from 1000 to 680 mAh g{sup −1}. Improved capacity is achieved by slightly increasing the temperature, as demonstrated by cycling the FPC-S at 35 °C using a current as high as 500 mA g{sup −1}. The excellent rate capability of the electrode is associated to the carbon texture and morphology that significantly lower the cell resistance, as indeed demonstrated by EIS measurement upon cycling. - Highlights: • Sulfur electrode basing on activated, flower-like hierarchical porous carbon is reported. • Defined micrometric morphology and a sulfur content as high as 66% are obtained. • Lithium sulfur cell using the composite exhibits remarkable performances. • A specific capacity of about 1000 mAh g{sup −1} is obtained at high current rate. • The resulting Li/S battery has relevant energy content.

  12. Modeling the condensation of sulfuric acid and water on the cylinder liner of a large two-stroke marine diesel engine

    DEFF Research Database (Denmark)

    Cordtz, Rasmus Faurskov; Mayer, Stefan; Eskildsen, Svend S.

    2018-01-01

    how fuel sulfur content, charge air humidity and liner temperature variations affects the deposition of water and sulfuric acid at low load operation. A phenomenological engine model is applied to simulate the formation of cylinder/bulk gas combustion products and dew points comply with H2O–H2SO4...

  13. Sulfur Dioxide Analyzer Instrument Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Springston, Stephen R. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-05-01

    The Sulfur Dioxide Analyzer measures sulfur dioxide based on absorbance of UV light at one wavelength by SO2 molecules which then decay to a lower energy state by emitting UV light at a longer wavelength. Specifically, SO2 + hυ1 →SO2 *→SO2 + hυ2 The emitted light is proportional to the concentration of SO2 in the optical cell. External communication with the analyzer is available through an Ethernet port configured through the instrument network of the AOS systems. The Model 43i-TLE is part of the i-series of Thermo Scientific instruments. The i-series instruments are designed to interface with external computers through the proprietary Thermo Scientific iPort Software. However, this software is somewhat cumbersome and inflexible. Brookhaven National Laboratory (BNL) has written an interface program in National Instruments LabView that both controls the Model 43i-TLE Analyzer AND queries the unit for all measurement and housekeeping data. The LabView vi (the software program written by BNL) ingests all raw data from the instrument and outputs raw data files in a uniform data format similar to other instruments in the AOS and described more fully in Section 6.0 below.

  14. Sulfur-carbon nanocomposites and their application as cathode materials in lithium-sulfur batteries

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-08-01

    The invention is directed in a first aspect to a sulfur-carbon composite material comprising: (i) a bimodal porous carbon component containing therein a first mode of pores which are mesopores, and a second mode of pores which are micropores; and (ii) elemental sulfur contained in at least a portion of said micropores. The invention is also directed to the aforesaid sulfur-carbon composite as a layer on a current collector material; a lithium ion battery containing the sulfur-carbon composite in a cathode therein; as well as a method for preparing the sulfur-composite material.

  15. Serpentinization of abyssal peridotites from the MARK area, Mid-Atlantic Ridge: Sulfur geochemistry and reaction modeling

    Science.gov (United States)

    Alt, J.C.; Shanks, Wayne C.

    2003-01-01

    The opaque mineralogy and the contents and isotope compositions of sulfur in serpentinized peridotites from the MARK (Mid-Atlantic Ridge, Kane Fracture Zone) area were examined to understand the conditions of serpentinization and evaluate this process as a sink for seawater sulfur. The serpentinites contain a sulfur-rich secondary mineral assemblage and have high sulfur contents (up to 1 wt.%) and elevated ??34Ssulfide (3.7 to 12.7???). Geochemical reaction modeling indicates that seawater-peridotite interaction at 300 to 400??C alone cannot account for both the high sulfur contents and high ??34Ssulfide. These require a multistage reaction with leaching of sulfide from subjacent gabbro during higher temperature (???400??C) reactions with seawater and subsequent deposition of sulfide during serpentinization of peridotite at ???300??C. Serpentinization produces highly reducing conditions and significant amounts of H2 and results in the partial reduction of seawater carbonate to methane. The latter is documented by formation of carbonate veins enriched in 13C (up to 4.5???) at temperatures above 250??C. Although different processes produce variable sulfur isotope effects in other oceanic serpentinites, sulfur is consistently added to abyssal peridotites during serpentinization. Data for serpentinites drilled and dredged from oceanic crust and from ophiolites indicate that oceanic peridotites are a sink for up to 0.4 to 6.0 ?? 1012 g seawater S yr-1. This is comparable to sulfur exchange that occurs in hydrothermal systems in mafic oceanic crust at midocean ridges and on ridge flanks and amounts to 2 to 30% of the riverine sulfate source and sedimentary sulfide sink in the oceans. The high concentrations and modified isotope compositions of sulfur in serpentinites could be important for mantle metasomatism during subduction of crust generated at slow spreading rates. ?? 2003 Elsevier Science Ltd.

  16. Peatland Acidobacteria with a dissimilatory sulfur metabolism.

    Science.gov (United States)

    Hausmann, Bela; Pelikan, Claus; Herbold, Craig W; Köstlbacher, Stephan; Albertsen, Mads; Eichorst, Stephanie A; Glavina Del Rio, Tijana; Huemer, Martin; Nielsen, Per H; Rattei, Thomas; Stingl, Ulrich; Tringe, Susannah G; Trojan, Daniela; Wentrup, Cecilia; Woebken, Dagmar; Pester, Michael; Loy, Alexander

    2018-02-23

    Sulfur-cycling microorganisms impact organic matter decomposition in wetlands and consequently greenhouse gas emissions from these globally relevant environments. However, their identities and physiological properties are largely unknown. By applying a functional metagenomics approach to an acidic peatland, we recovered draft genomes of seven novel Acidobacteria species with the potential for dissimilatory sulfite (dsrAB, dsrC, dsrD, dsrN, dsrT, dsrMKJOP) or sulfate respiration (sat, aprBA, qmoABC plus dsr genes). Surprisingly, the genomes also encoded DsrL, which so far was only found in sulfur-oxidizing microorganisms. Metatranscriptome analysis demonstrated expression of acidobacterial sulfur-metabolism genes in native peat soil and their upregulation in diverse anoxic microcosms. This indicated an active sulfate respiration pathway, which, however, might also operate in reverse for dissimilatory sulfur oxidation or disproportionation as proposed for the sulfur-oxidizing Desulfurivibrio alkaliphilus. Acidobacteria that only harbored genes for sulfite reduction additionally encoded enzymes that liberate sulfite from organosulfonates, which suggested organic sulfur compounds as complementary energy sources. Further metabolic potentials included polysaccharide hydrolysis and sugar utilization, aerobic respiration, several fermentative capabilities, and hydrogen oxidation. Our findings extend both, the known physiological and genetic properties of Acidobacteria and the known taxonomic diversity of microorganisms with a DsrAB-based sulfur metabolism, and highlight new fundamental niches for facultative anaerobic Acidobacteria in wetlands based on exploitation of inorganic and organic sulfur molecules for energy conservation.

  17. Halophilic and haloalkaliphilic sulfur-oxidizing bacteria

    NARCIS (Netherlands)

    Sorokin, D.Y.; Banciu, H.; Robertson, L.A.; Kuenen, J.G.; Muntyan, M.S.; Muyzer, G.; Rosenberg, E.; DeLong, F.; Delong, E.; Lory, S.; Stackebrandt, E.; Thompson, F.

    2013-01-01

    Chemotrophic sulfur-oxidizing bacteria (SOB) represent an important functional group of microorganisms responsible for the dark oxidation of reduced sulfur compounds generated by sulfidogens. Until recently, only a single genus of halophilic SOB (Halothiobacillus) has been described, and nothing was

  18. Stability of sulfur slopes on Io

    Science.gov (United States)

    Clow, G. D.; Carr, M. H.

    1980-01-01

    The mechanical properties of elemental sulfur are such that the upper crust of Io cannot be primarily sulfur. For heat flows in the range 100-1000 ergs/sq cm sec sulfur becomes ductile within several hundred meters of the surface and would prevent the formation of calderas with depths greater than this. However, the one caldera for which precise depth data are available is 2 km deep, and this value may be typical. A study of the mechanical equilibrium of simple slopes shows that the depth to the zone of rapid ductile flow strongly controls the maximum heights for sulfur slopes. Sulfur scarps with heights greater than 1 km will fail for all heat flows greater than 180 ergs/sq cm sec and slope angles greater than 22.5 deg. The observed relief on Io is inconsistent with that anticipated for a predominantly sulfur crust. However, a silicate crust with several percent sulfur included satisfies both the mechanical constraints and the observed presence of sulfur on Io.

  19. Microbiological disproportionation of inorganic sulfur compounds

    DEFF Research Database (Denmark)

    Finster, Kai

    2008-01-01

    The disproportionation of inorganic sulfur intermediates at moderate temperatures (0-80 °C) is a microbiologically catalyzed chemolithotrophic process in which compounds like elemental sulfur, thiosulfate, and sulfite serve as both electron donor and acceptor, and generate hydrogen sulfide and su...

  20. An investigation of sulfur concentrations in soils and pine needles in Chaco Culture National Historical Park, New Mexico

    International Nuclear Information System (INIS)

    Gladney, E.S.; Ferenbaugh, R.W.; Jones, E.A.; Bell, M.G.; Morgan, J.D.; Nelson, L.A.; Bowker, R.G.

    1993-03-01

    Sulfur measurements in different age groups of pinon pine needles and adjacent soil samples from ten sampling sites at Chaco Culture National Historical Park were determined using combustion elemental analysis and chromatographic techniques. The primary goal was to establish base-line levels for elemental sulfur in the Park. Sulfur levels in foliage and soils were evaluated using analysis of variance techniques. No significant differences were found in foliage sulfur concentrations among the 10 sampling sites; however, trees within sites were significantly different. Needles of different ages did not differ significantly in sulfur content. Average soil concentrations were low, approximately 30% of the average needle concentrations. Soil sulfur concentrations did not differ significantly among the 10 sampling sites; however, different depths in the soil had statistically different concentrations of sulfur. No statistical differences were evident in soils sampled at the four compass points (N,S,E,W) around each tree. These differences imply that large numbers of samples are needed to identify small effects from anthropogenic inputs of sulfur into the system or that the effects must be large relative to the differences among sampling sites and individual trees in order to be detected

  1. Multiple-heteroatom-containing sulfur compounds in a high sulfur coal

    International Nuclear Information System (INIS)

    Winans, R.E.; Neill, P.H.

    1990-01-01

    Flash vacuum pyrolysis of a high sulfur coal has been combined with high resolution mass spectrometry yielding information on aromatic sulfur compounds containing an additional heteroatom. Sulfur emission from coal utilization is a critical problem and in order to devise efficient methods for removing organic sulfur, it is important to know what types of molecules contain sulfur. A high sulfur Illinois No. 6 bituminous coal (Argonne Premium Coal Sample No. 3) was pyrolyzed on a platinum grid using a quartz probe inserted into a modified all glass heated inlet system and the products characterized by high resolution mass spectrometry (HRMS). A significant number of products were observed which contained both sulfur and an additional heteroatom. In some cases two additional heteroatoms were observed. These results are compared to those found in coal extracts and liquefaction products

  2. Sulfur amino acids metabolism in magnesium deficient rats

    Energy Technology Data Exchange (ETDEWEB)

    Tojo, H.; Kosokawa, Y.; Yamaguchi, K.

    1984-01-01

    Effect of magnesium (Mg) deficiency on sulfur amino acid metabolism was investigated in rats. Young male rats were fed on the diet containing either 2.26 (deficient rats) or 63.18 mg Mg/100g diet (control and low protein rats) for 2 weeks. A remarkable decrease of body weight gain, serum Mg contents and a slight decreases in the hematological parameters such as Hb, Ht and RBC was observed, while the hepatic Mg and Ca was not significantly changed. Erythema and cramps were observed 5 days after feeding on the Mg-depleted diet. The hepatic glutathione and cysteine contents increased in Mg-deficient rats. However, no significant change of cysteine dioxygenase (CDO) activity and taurine content in Mg-deficient rat liver was observed. These results suggest that Mg deficiency affects the utilization and biosynthesis of hepatic glutathione but not the cysteine catabolism.

  3. Sulfur in serpentinized oceanic peridotites: Serpentinization processes and microbial sulfate reduction

    Science.gov (United States)

    Alt, J.C.; Shanks, Wayne C.

    1998-01-01

    The mineralogy, contents, and isotopic compositions of sulfur in oceanic serpentinites reflect variations in temperatures and fluid fluxes. Serpentinization of serpentinization of Iberian Margin peridotites occurred at low temperatures (???20??-200??C) and high water/rock ratios. Complete serpentinization and consumption of ferrous iron allowed evolution to higher fO2. Microbial reduction of seawater sulfate resulted in addition of low-??34S sulfide (-15 to -43???) and formation of higher-sulfur assemblages that include valleriite and pyrite. The high SO4/total S ratio of Hess Deep serpentinites (0.89) results in an increase of total sulfur and high ??34S of total sulfur (mean ??? 8???). In contrast, Iberian Margin serpentinites gained large amounts of 34S-poor sulfide (mean total S = 3800 ppm), and the high sulfide/total S ratio (0.61) results in a net decrease in ??34S of total sulfur (mean ??? -5???). Thus serpentinization is a net sink for seawater sulfur, but the amount fixed and its isotopic composition vary significantly. Serpentinization may result in uptake of 0.4-14 ?? 1012 g S yr-1 from the oceans, comparable to isotopic exchange in mafic rocks of seafloor hydrothermal systems and approaching global fluxes of riverine sulfate input and sedimentary sulfide output.

  4. Pengaruh Pemberian Urea dan Sulfur pada Pembuatan Silase Limbah Padat Bioetanol yang Diberi Starter Em-4

    Directory of Open Access Journals (Sweden)

    Yani Suryani

    2017-04-01

    (Effect of urea and sulfur addition on silage from bioethanol solid waste using EM-4 starters  ABSTRACT. In the making of bioethanol made of cassava as basic component produce solid waste that has potential as livestock feed. However, this waste product is of low nutritional value when given directly to the livestocks due to the high crude fiber. Therefore, waste should be done with pretreatment, and one of the way was done by fermentation. The aim of this research was to observe the effect of urea and sulfur additive in the making of bioethanol solid waste silage by using EM-4 starters. This research used 3 x 3 Completely Randomized Design with 3 replicates. The first factor was urea additive with different dosage N1=0%, N2=1.5%, N3=3%, and the second factor was sulfur additive with dosage S1=0.00%, S2=0.02%, S3=0.04%. The measured variables were concentration of lactic acid, pH, dry matter loss, and crude fiber content. The results showed that there were no interactions between urea and sulfur. Addition of 3% urea and 0,04% sulfur in substrate showed the highest of lactic acid with the average value of 1.32% and the lowest pH and crude fiber with average value 3.33 and 9.02%. It was concluded that combination of 3% urea and 0,04% sulfur was the best treatment.

  5. A MnO2/Graphene Oxide/Multi-Walled Carbon Nanotubes-Sulfur Composite with Dual-Efficient Polysulfide Adsorption for Improving Lithium-Sulfur Batteries.

    Science.gov (United States)

    Li, Yong; Ye, Daixin; Liu, Wen; Shi, Bin; Guo, Rui; Zhao, Hongbin; Pei, Haijuan; Xu, Jiaqiang; Xie, Jingying

    2016-10-26

    Lithium-sulfur batteries can potentially be used as a chemical power source because of their high energy density. However, the sulfur cathode has several shortcomings, including fast capacity attenuation, poor electrochemical activity, and low Coulombic efficiency. Herein, multi-walled carbon nanotubes (CNTs), graphene oxide (GO), and manganese dioxide are introduced to the sulfur cathode. A MnO 2 /GO/CNTs-S composite with a unique three-dimensional (3D) architecture was synthesized by a one-pot chemical method and heat treatment approach. In this structure, the innermost CNTs work as a conducting additive and backbone to form a conducting network. The MnO 2 /GO nanosheets anchored on the sidewalls of CNTs have a dual-efficient absorption capability for polysulfide intermediates as well as afford adequate space for sulfur loading. The outmost nanosized sulfur particles are well-distributed on the surface of the MnO 2 /GO nanosheets and provide a short transmission path for Li + and the electrons. The sulfur content in the MnO 2 /GO/CNTs-S composite is as high as 80 wt %, and the as-designed MnO 2 /GO/CNTs-S cathode displays excellent comprehensive performance. The initial specific capacities are up to 1500, 1300, 1150, 1048, and 960 mAh g -1 at discharging rates of 0.05, 0.1, 0.2, 0.5, and 1 C, respectively. Moreover, the composite cathode shows a good cycle performance: the specific capacity remains at 963.5 mAh g -1 at 0.2 C after 100 cycles when the area density of sulfur is 2.8 mg cm -2 .

  6. Flexible three-dimensional electrodes of hollow carbon bead strings as graded sulfur reservoirs and the synergistic mechanism for lithium–sulfur batteries

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Dan [College of Materials Science and Engineering, Sichuan University, Chengdu, 610064 (China); Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang, 621900 (China); Ni, Wei, E-mail: niwei@iccas.ac.cn [Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang, 621900 (China); Cheng, Jianli; Wang, Zhuanpei; Wang, Ting; Guan, Qun [Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang, 621900 (China); Zhang, Yun, E-mail: y_zhang@scu.edu.cn [College of Materials Science and Engineering, Sichuan University, Chengdu, 610064 (China); Wu, Hao [College of Materials Science and Engineering, Sichuan University, Chengdu, 610064 (China); Li, Xiaodong [Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang, 621900 (China); Wang, Bin, E-mail: edward.bwang@gmail.com [Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang, 621900 (China)

    2017-08-15

    Graphical abstract: Flexible three-dimensional electrode comprised of stringed N-doped hollow carbon spheres shows a synergistic sulfur confinement mechanism and a higher energy/power density for the promising lithium-sulfur batteries compared with traditional electrodes. - Highlights: • Hollow carbon beads on string structure was first prepared. • Flexible 3D electrodes as graded reservoirs for polysulfides were conducted. • Synergistic effect for enhanced polysulfides storage was claimed. - Abstract: Three-dimensional (3D) flexible electrodes of stringed hollow nitrogen-doped (N-doped) carbon nanospheres as graded sulfur reservoirs and conductive frameworks were elaborately designed via a combination of the advantages of hollow structures, 3D electrodes and flexible devices. The as-prepared electrodes by a synergistic method of electrospinning, template sacrificing and activation for Li–S batteries without any binder or conductive additives but a 3D interconnected conductive network offered multiple transport paths for electrons and improved sulfur utilization and facilitated an easy access to Li{sup +} ingress/egress. With the increase of density of hollow carbon spheres in the strings, the self-supporting composite electrode reveals an enhanced synergistic mechanism for sulfur confinement and displays a better cycling stability and rate performance. It delivers a high initial specific capacity of 1422.6 mAh g{sup −1} at the current rate of 0.2C with the high sulfur content of 76 wt.%, and a much higher energy density of 754 Wh kg{sup −1} and power density of 1901 Wh kg{sup −1}, which greatly improve the energy/power density of traditional lithium–sulfur batteries and will be promising for further commercial applications.

  7. Influence of sulfur dioxide and ozone on vegetation of bean and barley plants under different soil moisture conditions

    Energy Technology Data Exchange (ETDEWEB)

    Markowski, A; Grzesiak, S

    1974-01-01

    The effects of toxic gases on extent of injuries to assimilating surface, dry weight yields, and generative development in bean and barley were studied in three successive phases of vegetation under conditions of optimum soil moisture and of drought just above the wilting point. Experiments with ozone and sulfur dioxide on bean and SO/sub 2/ on barley demonstrate that the susceptibility of plants to toxic gases decrease under drought conditions that cause a temporary dehydration of tissues. Determinations of sulfate sulfur contents in different plant organs show that a lower hydration of tissues is accompanied by lower adsorption of sulfur dioxide.

  8. Effect of Water Stress and Sulfur Fertilizer on Grain Yield, Chlorophyll and Nutrient Status of Black Cumin (Nigella Sativa L.)

    OpenAIRE

    M. Heidari; A. R. Rezapor

    2011-01-01

    In order to study the effects of water stress and different amounts of sulfur fertilizer on grain yield, nutrient status and chlorophyll content in black cumin (Nigella sativa L.) a field experiment as split plot design with three replications was conducted at Ghaen city in 2009. Treatments included three levels of irrigation after 50, 100 and 150 mm evaporation from Class A pan as main plot and four levels of sulfur fertilizer including 0, 75, 150 and 225 kg/ha from bentonite-sulfur source a...

  9. Sulfur Speciation in Peat: a Time-zero Signature for the " Spruce and Peatland Responses Under Climate and Environmental Change" Experiment

    Science.gov (United States)

    Furman, O.; Toner, B. M.; Sebestyen, S. D.; Kolka, R. K.; Nater, E. A.

    2014-12-01

    As part of the "Spruce and Peatland Responses Under Climate and Environmental Change" (SPRUCE) experiment, we made initial measurements of sulfur speciation in peat. These observations represent a "time-zero" relative to the intended soil warming experiment which begins in 2015. Total sulfur and sulfur speciation were measured in peat cores (solid phase) from nine plots (hollows and hummocks) to a depth of 2 m. Peat samples were packed under nitrogen and frozen in the field immediately after collection. All subsequent sample storage, handling, and processing were conducted under inert gas. Sulfur speciation was measured using bulk sulfur 1s X-ray absorption near edge structure (XANES) spectroscopy at the SXRMB instrument at the Canadian Light Source, Saskatoon, SK, Canada and at the 9-BM instrument, Advanced Photon Source, Argonne National Laboratory, IL, USA. Total sulfur concentrations ranged from 968 to 4077 mg sulfur / kg dry peat. Sulfur content increased with depth from 2 g sulfur / m2 in the 0-10 cm increment to a maximum value of 38 g sulfur / m2 in the 50-60 cm increment. These sulfur loadings produced high quality XANES spectra. The nine cores exhibited reproducible trends with depth in both total sulfur and specific sulfur species; however, variability in sulfur speciation was greatest in the top 40 cm. All sulfur detected within the peat solids was in an organic form. The most abundant sulfur species group was composed of organic mono-sulfide and thiol forms, representing approximately half of the total sulfur at all depths. Sulfonate and ester-sulfate species were 10-15 mol% of sulfur and exhibited low variability with depth. A subsurface maximum in organic di-sulfide was observed in the 20-30 cm depth increment, which is the transition zone between transiently oxidized acrotelm and permanently saturated anaerobic catotelm. Quantification of major sulfur pools is important for the SPRUCE experiment as they are likely to be indicators of changes in the

  10. Hysteresis Phenomena in Sulfur Dioxide Oxidation over Supported Vanadium Catalysts

    DEFF Research Database (Denmark)

    Masters, Stephen G.; Eriksen, Kim Michael; Fehrmann, Rasmus

    1997-01-01

    Catalyst deactivation and hysteresis behavior in industrial SO2-oxidation catalysts have been studied in the temperature region 350-480 C by combined in situ EPR spectroscopy and catalytic activity measurements. The feed gas composition simulated sulfuric acid synthesis gas and wet/dry de......NOx'ed flue gas. The vanadium (IV) compound K4(VO)3(SO4)5 precipitated during all the investigated conditions hence causing catalyst deactivation. Hysteresis behavior of both the catalytic activity and the V(IV) content was observed during reheating....

  11. The complete genome sequence of Staphylothermus marinus reveals differences in sulfur metabolism among heterotrophic Crenarchaeota

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, iain J.; Dharmarajan, Lakshmi; Rodriguez, Jason; Hooper, Sean; Porat, Iris; Ulrich, Luke E.; Elkins, James G.; Mavromatis, Kostas; Sun, Hui; Land, Miriam; Lapidus, Alla; Lucas, Susan; Barry, Kerrie; Huber, Harald; Zhulin, Igor B.; Whitman, William B.; Mukhopadhyay, Biswarup; Woese, Carl; Bristow, James; Kyrpides, Nikos

    2008-09-05

    Staphylothermus marinus is an anaerobic, sulfur-reducing peptide fermenter of the archaeal phylum Crenarchaeota. It is the third heterotrophic, obligate sulfur reducing crenarchaeote to be sequenced and provides an opportunity for comparative analysis of the three genomes. The 1.57 Mbp genome of the hyperthermophilic crenarchaeote Staphylothermus marinus has been completely sequenced. The main energy generating pathways likely involve 2-oxoacid:ferredoxin oxidoreductases and ADP-forming acetyl-CoA synthases. S. marinus possesses several enzymes not present in other crenarchaeotes including a sodium ion-translocating decarboxylase likely to be involved in amino acid degradation. S. marinus lacks sulfur-reducing enzymes present in the other two sulfur-reducing crenarchaeotes that have been sequenced - Thermofilum pendens and Hyperthermus butylicus. Instead it has three operons similar to the mbh and mbx operons of Pyrococcus furiosus, which may play a role in sulfur reduction and/or hydrogen production. The two marine organisms, S. marinus and H. butylicus, possess more sodium-dependent transporters than T. pendens and use symporters for potassium uptake while T. pendens uses an ATP-dependent potassium transporter. T. pendens has adapted to a nutrient-rich environment while H. butylicus is adapted to a nutrient-poor environment, and S. marinus lies between these two extremes. The three heterotrophic sulfur-reducing crenarchaeotes have adapted to their habitats, terrestrial vs. marine, via their transporter content, and they have also adapted to environments with differing levels of nutrients. Despite the fact that they all use sulfur as an electron acceptor, they are likely to have different pathways for sulfur reduction.

  12. Yolk-Shelled C@Fe3 O4 Nanoboxes as Efficient Sulfur Hosts for High-Performance Lithium-Sulfur Batteries.

    Science.gov (United States)

    He, Jiarui; Luo, Liu; Chen, Yuanfu; Manthiram, Arumugam

    2017-09-01

    Owing to the high theoretical specific capacity (1675 mA h g -1 ) and low cost, lithium-sulfur (Li-S) batteries offer advantages for next-generation energy storage. However, the polysulfide dissolution and low electronic conductivity of sulfur cathodes limit the practical application of Li-S batteries. To address such issues, well-designed yolk-shelled carbon@Fe 3 O 4 (YSC@Fe 3 O 4 ) nanoboxes as highly efficient sulfur hosts for Li-S batteries are reported here. With both physical entrapment by carbon shells and strong chemical interaction with Fe 3 O 4 cores, this unique architecture immobilizes the active material and inhibits diffusion of the polysulfide intermediates. Moreover, due to their high conductivity, the carbon shells and the polar Fe 3 O 4 cores facilitate fast electron/ion transport and promote continuous reactivation of the active material during the charge/discharge process, resulting in improved electrochemical utilization and reversibility. With these merits, the S/YSC@Fe 3 O 4 cathodes support high sulfur content (80 wt%) and loading (5.5 mg cm -2 ) and deliver high specific capacity, excellent rate capacity, and long cycling stability. This work provides a new perspective to design a carbon/metal-oxide-based yolk-shelled framework as a high sulfur-loading host for advanced Li-S batteries with superior electrochemical properties. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Milestones in plant sulfur research on sulfur-induced-resistance (SIR in Europe

    Directory of Open Access Journals (Sweden)

    Elke eBloem

    2015-01-01

    Full Text Available Until the 1970´s of the last century sulfur (S was mainly regarded as a pollutant being the main contributor of acid rain, causing forest dieback in central Europe. When Clean Air Acts came into force at the start of the 1980´s SO2 contaminations in the air were consequently reduced within the next years. S changed from an unwanted pollutant into a lacking plant nutrient in agriculture since agricultural fields were no longer fertilized indirectly by industrial pollution. S deficiency was first noticed in Brassica crops that display an especially high S demand because of its content of S-containing secondary metabolites, the glucosinolates. In Scotland, where S depositions decreased even faster than in continental Europe, an increasing disease incidence with Pyrenopeziza brassicae was observed in oilseed rape in the beginning 1990´s and the concept of sulfur-induced-resistance (SIR was developed after a relationship between the S status and the disease incidence was uncovered. Since then a lot of research was carried out to unravel the background of SIR in the metabolism of agricultural crops and to identify metabolites, enzymes and reactions, which are potentially activated by the S metabolism to combat fungal pathogens. The S status of the crop is affecting many different plant features such as color and scent of flowers, pigments in leaves, metabolite concentrations and the release of gaseous S compounds which are directly influencing the desirability of a crop for a variety of different organisms from microorganisms, over insects and slugs to the point of grazing animals.The present paper is an attempt to sum up the knowledge about the effect of the S nutritional status of agricultural crops on parameters that are directly related to their health status and by this to SIR. Milestones in SIR research are compiled, open questions are addressed and future projections were developed.

  14. Interface polymerization synthesis of conductive polymer/graphite oxide@sulfur composites for high-rate lithium-sulfur batteries

    International Nuclear Information System (INIS)

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

    2015-01-01

    Highlights: • A hybrid nanostructure that incorporate the merits of conductive polymer nanorods and graphite oxide sheets. • A novel approach based on interface polymerization for synthesizing CP/GO@S ternary composite. • CP/GO@S ternary composite cathode shows enhanced electrochemical properties compared with CP@S binary composite cathode. • PEDOT/GO@S composite is the material system that have best electrochemical performance in all CP/GO@S ternary composites. - Abstract: The novel ternary composites, conductive polymers (CPs)/graphene oxide (GO)@sulfur composites were successfully synthesized via a facile one-pot route and used as cathode materials for Li-S batteries The poly(3,4-ethylenedioxythiophene) (PEDOT)/GO and polyaniline (PANI)/GO composites were prepared by interface polymerization of monomers on the surface of GO sheets. Then sulfur was in-situ deposited on the CPs/GO composites in same solution. The component and structure of the composites were characterized by XPS, TGA, FTIR, SEM, TEM and electrochemical measurements. In this structure, the CPs nanostructures are believed to serve as a conductive matrix and an adsorbing agent, while the highly conductive GO will physically and chemically confine the sulfur and polysulfide within cathode. The PEDOT/GO@S composites with the sulfur content of 66.2 wt% exhibit a reversible discharge capacity of 800.2 mAh g −1 after 200 cycles at 0.5 C, which is much higher than that of PANI/GO@S composites (599.1 mAh g −1 ) and PANI@S (407.2 mAh g −1 ). Even at a high rate of 4 C, the PEDOT/GO@S composites still retain a high specific capacity of 632.4 mAh g −1

  15. Sulfur isotope studies of biogenic sulfur emissions at Wallops Island, Virginia

    International Nuclear Information System (INIS)

    Hitchcock, D.R.; Black, M.S.; Herbst, R.P.

    1978-03-01

    This research attempted to determine whether it is possible to measure the stable sulfur isotope distributions of atmospheric particulate and gaseous sulphur, and to use this information together with measurements of the ambient levels of sulfur gases and particulate sulfate and sodium in testing certain hypotheses. Sulfur dioxide and particulate sulfur samples were collected at a coastal marine location and their delta (34)S values were determined. These data were used together with sodium concentrations to determine the presence of biogenic sulfur and the identity of the biological processes producing it. Excess (non-seasalt) sulfate levels ranged from 2 to 26 micrograms/cu m and SO2 from 1 to 9 ppb. Analyses of air mass origins and lead concentrations indicated that some anthropogenic contaminants were present on all days, but the isotope data revealed that most of the atmospheric sulfur originated locally from the metabolism of bacterial sulfate reducers on all days, and that the atmospheric reactions leading to the production of sulfate from this biogenic sulfur source are extremely rapid. Delta 34 S values of atmospheric sulfur dioxide correlated well with those of excess sulfate, and implied little or no sulfur isotope fractionation during the oxidation of sulfur gases to sulfate

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

    Science.gov (United States)

    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.

  17. Influence of sulfurous oxide on plants

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, J

    1872-01-01

    It has been determined that of the trees living in an atmosphere containing sulfurous oxide, the conifers suffer more injuries than ordinary foliaged trees. Experiments were conducted to find the causes of injuries and their relation in these two kinds of plants. Pine and alder were chosen as test plants. It was found that 1000 square centimeters of pine leaves had absorbed 1.6 c.c. of sulfurous oxide and the same surface area of alder leaves had accumulated 7.9 c.c. of sulfurous oxide. Experiments were also conducted to determine the effects of sulfurous oxide on transpiration in plants. Two similar twigs of a sycamore were arranged so that the water transpired could be weighed. Results indicate that the ratio between the total amount of water transpired by the leaves not acted on by the sulfurous oxide and those under its influence was 3.8:1. The author concludes that the amount of sulfurous oxide absorbed by pine leaves is smaller than that absorbed by trees with ordinary foliage for equal surfaces. Since its effect on transpiration is less in the case of pine, the cause of the greater injury to pine trees in nature must be due to the accumulation of sulfur. In trees annual leaves the damage to one year's foliage would have only an indirect influence on that of the following year.

  18. Biological removal of sulfur from coal flotation concentrate by culture isolated from coal washery plant tailing dump

    Energy Technology Data Exchange (ETDEWEB)

    Jorjani, E. [Azad University, Tehran (Iran). Mining Engineering Dept.

    2005-10-15

    A combination of flotation and microbial leaching processes was used to achieve acceptable level of sulfur and ash in Tabas coal sample of Iran. Representative sample of the minus 500 micron size fraction was subjected to flotation separation for the removal of ash and sulfur. The final concentrate with recovery, combustion value and sulfur content of 86.03, 86.45 and 1.35% respectively was achieved at pH 8 and following reagent dosage and operating conditions: collector: diesel oil (1200 g/ton), frother: MIBC (5%) + pine oil (95%) with concentration of 120 (g/ton), depressant: sodium silicate (1000 g/ton), particle size: {lt} 500 {mu} m and pulp density: 7%. Because of fine distribution of sulfur on Tabas coal macerals and lithotypes, high percentage of total sulfur (79.9%) is distributed in flotation concentrate and only 20.1% is yielded in the tails. So microbial leaching using a species isolated from coal washery plant tailing dump was used in batch system to remove sulfur from flotation concentrate. The conditions were optimized for the maximum removal of sulfur. These conditions were found to be pH of 2, particle size less than 0.18 mm; pulp density: 8%, temperature: 30 {sup o}C, shaking rate: 150 rpm conditions. Total sulfur and ash content was reduced by bioleaching from 13.55 and 1.35 in flotation concentrate to 9.47 and 0.55 in the final leached concentrate, a reduction of 35 and 61.9% respectively. Sterilization of coal adversely affects the sulfur reduction. The results suggest that the isolated culture is sufficiently effective for depyritization of Tabas coal flotation concentrate in stirred system.

  19. Viscosity of liquid sulfur under high pressure

    International Nuclear Information System (INIS)

    Terasaki, Hidenori; Kato, T; Funakoshi, K; Suzuki, A; Urakawa, S

    2004-01-01

    The viscosity of liquid sulfur up to 9.7 GPa and 1067 K was measured using the in situ x-ray radiography falling sphere method. The viscosity coefficients were found to range from 0.11 to 0.69 Pa s, and decreased continuously with increasing pressure under approximately constant homologous temperature conditions. The observed viscosity variation suggests that a gradual structural change occurs in liquid sulfur with pressure up to 10 GPa. The L-L' transition in liquid sulfur proposed by Brazhkin et al (1991 Phys. Lett. A 154 413) from thermobaric measurements has not been confirmed by the present viscometry

  20. Insight into the loading temperature of sulfur on sulfur/carbon cathode in lithium-sulfur batteries

    International Nuclear Information System (INIS)

    Ye, Huan; Yin, Ya-Xia; Guo, Yu-Guo

    2015-01-01

    Highlights: • A cost-effective chemical activation method to prepare porous carbon nanospheres. • Carbon nanospheres with bimodal microporous structure show high specific area and large micropore volume. • The S/C composite cathodes with in-situformed S−C bond exhibit high sulfur activity with a reversible capacity of 1000 mA h g −1 . • S−C bond enables well confinement on sulfur and polysulfides. - Abstract: Lithium–sulfur batteries are highly desired because of their characteristics such as high energy density. However, the applications of Li-S batteries are limited because they exist dissolution of polysulfides into electrolytes. This study reports the preparation of sulfur cathodes by using bimodal microporous (0.5 nm and 0.8 nm to 2.0 nm) carbon spheres with high specific area (1992 m 2 g −1 ) and large micropore volume (1.2 g cm −1 ), as well as the encapsulation of polysulfides via formation of carbon–sulfur bonds in a sealed vacuum glass tube at high temperature. Given that sulfur and polysulfides are well confined by the S−C bond, the shuttle effect is effectively suppressed. The prepared S/C cathodes with a sulfur loading of up to 75% demonstrate high sulfur activity with reversible capacity of 1000 mA h g −1 at the current density of 0.1 A g −1 and good cycling stability (667 mA h g −1 after 100 cycles).

  1. Graphene oxide as a sulfur immobilizer in high performance lithium/sulfur cells

    Science.gov (United States)

    Zhang, Yuegang; Cairns, Elton J.; Ji, Liwen; Rao, Mumin

    2017-06-06

    The loss of sulfur cathode material as a result of polysulfide dissolution causes significant capacity fading in rechargeable lithium/sulfur cells. Embodiments of the invention use a chemical approach to immobilize sulfur and lithium polysulfides via the reactive functional groups on graphene oxide. This approach obtains a uniform and thin (.about.tens of nanometers) sulfur coating on graphene oxide sheets by a chemical reaction-deposition strategy and a subsequent low temperature thermal treatment process. Strong interaction between graphene oxide and sulfur or polysulfides demonstrate lithium/sulfur cells with a high reversible capacity of 950-1400 mAh g.sup.-1, and stable cycling for more than 50 deep cycles at 0.1 C.

  2. Sulfurized carbon: a class of cathode materials for high performance lithium/sulfur batteries

    Directory of Open Access Journals (Sweden)

    Sheng S. Zhang

    2013-12-01

    Full Text Available Liquid electrolyte lithium/sulfur (Li/S batteries cannot come into practical applications because of many problems such as low energy efficiency, short cycle life, and fast self-discharge. All these problems are related to the dissolution of lithium polysulfide, a series of sulfur reduction intermediates, in the liquid electrolyte, and resulting parasitic reactions with the Li anode. Covalently binding sulfur onto carbon surface is a solution to completely eliminate the dissolution of lithium polysulfide and make the Li/S battery viable for practical applications. This can be achieved by replacing elemental sulfur with sulfurized carbon as the cathode material. This article reviews the current efforts on this subject and discusses the syntheses, electrochemical properties, and prospects of the sulfurized carbon as a cathode material in the rechargeable Li/S batteries.

  3. Graphene oxide as a sulfur immobilizer in high performance lithium/sulfur cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yuegang; Cairns, Elton J.; Ji, Liwen; Rao, Mumin

    2017-12-26

    The loss of sulfur cathode material as a result of polysulfide dissolution causes significant capacity fading in rechargeable lithium/sulfur cells. Embodiments of the invention use a chemical approach to immobilize sulfur and lithium polysulfides via the reactive functional groups on graphene oxide. This approach obtains a uniform and thin (.about.tens of nanometers) sulfur coating on graphene oxide sheets by a chemical reaction-deposition strategy and a subsequent low temperature thermal treatment process. Strong interaction between graphene oxide and sulfur or polysulfides demonstrate lithium/sulfur cells with a high reversible capacity of 950-1400 mAh g.sup.-1, and stable cycling for more than 50 deep cycles at 0.1 C.

  4. Method for modeling the deposition of sulfur by precipitation over regional scales

    International Nuclear Information System (INIS)

    Hicks, B.B.; Shannon, J.D.

    1979-01-01

    Radioactive fallout data suggest that the concentration of pollutants in rainfall, while highly variable, might be described on the average by about an inverse half-power dependence on the amount of precipitation. Recent measurements of sulfur concentrations in summer rainfall collected at Argonne National Laboratory tend to support this contention, as do preliminary results derived from operations of the DOE precipitation chemistry network. The concept is extended to develop a bulk removal rate for airborne total sulfur by precipitation for use in regional dispersion modeling

  5. Sulfur turnover and emissions during storage of cattle slurry

    DEFF Research Database (Denmark)

    Eriksen, Jørgen; Andersen, Astrid J; Poulsen, Henrik Vestergaard

    2012-01-01

    Slurry acidification using sulfuric acid reduces ammonia emissions but also affects sulfur (S) cycling. Emission of sulfur is a source of malodor and reduces the sulfur fertilizer value of the slurry. We investigated the effect of sulfate and methionine amendments, alone or in combination...

  6. Study on the Influence of Sulfur Fumigation on Chemical ...

    African Journals Online (AJOL)

    Purpose: To study the influence of different sulfur fumigation time and ... after sulfur fumigation though sulfur fumigation time and dosage were at low levels – 2 h ... Conclusion: Sulfur fumigation is not a desirable method for field processing of ...

  7. 46 CFR 151.50-21 - Sulfuric acid.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Sulfuric acid. 151.50-21 Section 151.50-21 Shipping... BULK LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-21 Sulfuric acid. (a) How sulfuric acid may be carried. (1) Sulfuric acid of concentration of 77.5 percent (1.7019 specific gravity) (59.8...

  8. Improved Electrochemical Performance of Biomass-Derived Nanoporous Carbon/Sulfur Composites Cathode for Lithium-Sulfur Batteries by Nitrogen Doping

    International Nuclear Information System (INIS)

    Geng, Zhen; Xiao, Qiangfeng; Wang, Dabin; Yi, Guanghai; Xu, Zhigang; Li, Bing; Zhang, Cunman

    2016-01-01

    A two-step method with high-efficiency is developed to prepare nitrogen doped activated carbons (NACs) with high surface area and nitrogen content. Based on the method, series of NACs with similar surface area and pore texture but different nitrogen content and nitrogen group species are successfully prepared. The influence of nitrogen doping on electrochemical performance of carbon/sulfur composites cathode is studied deeply under the conditions of similar surface area and pore texture. It presents the directly experimental demonstration that both nitrogen content and nitrogen group species play crucial roles on electrochemical performance of carbon/sulfur composites cathode. NAC/sulfur composites show the much improved cycling performance, which is about 3.5 times as that of nitrogen free carbon. Improved electrochemical performance is due to synergistic effects between nitrogen content and effective nitrogen groups, which enables effective trapping of lithium polysulfides within carbon framework. Besides, it is found that oxygen groups exist in carbon materials obviously influence electrochemical performance of cathode, which could be ignored in most of studies. Based on above, it can be concluded that enhanced chemisorption to lithium polysulfides by functional groups modification is the effective route to improve the electrochemical performance of Li-S battery.

  9. Use of sulfur concrete for radioecological problems solution in Kazakhstan

    International Nuclear Information System (INIS)

    Takibaev, Zh.; Belyashov, D.; Vagin, S.

    2001-01-01

    At present during intensive development of oil and gas fields in Kazakhstan a lot amount of sulfur is extracting. The problem of sulfur utilization demands its immediate solution. One of the perspective trends of sulfur utilization is use it in production of sulfur polymer concrete. It is well known, that encapsulation of low level radioactive and toxic wastes in sulfur polymer concrete and design from it radiation protection facilities have good perspectives for solution of radioecological problems. Sulfur concrete has high corrosion and radiation stability, improved mechanical and chemical properties. Unique properties of sulfur concrete allow to use it in materials ensuring protection from external irradiation

  10. Electrochemical reduction of sulfur dioxide in sulfolane

    Energy Technology Data Exchange (ETDEWEB)

    Vorob' ev, A.S.; Gavrilova, A.A.; Kolosnitsyn, V.S.; Nikitin, Yu.E.

    1985-09-01

    Solutions of sulfur dioxide in aproptic media are promising electrolyte oxidizing agents for chemical current sources with anodes of active metals. This work describes the electrochemical reduction of sulfur dioxide in sulfolane in a lithium halide supporting electrolyte which was investigated by the methods of voltamperometry and chronopotentiometry. The dependence of the current of the cathodic peak on the concentration of the supporting electrolyte salts, sulfur dioxide and water, was studied. On the basis of the data obtained, a hypothesis was advanced on the nature of the limiting step. The investigation showed that at low polarizing current densities, a substantial influence on the reduction of sulfur dioxide in sulfolane in a lithium halide supporting electrolyte is exerted by blockage of the electrode surface by sparingly soluble reaction products.

  11. Efficient Electrolytes for Lithium–Sulfur Batteries

    International Nuclear Information System (INIS)

    Angulakshmi, Natarajan; Stephan, Arul Manuel

    2015-01-01

    This review article mainly encompasses on the state-of-the-art electrolytes for lithium–sulfur batteries. Different strategies have been employed to address the issues of lithium–sulfur batteries across the world. One among them is identification of electrolytes and optimization of their properties for the applications in lithium–sulfur batteries. The electrolytes for lithium–sulfur batteries are broadly classified as (i) non-aqueous liquid electrolytes, (ii) ionic liquids, (iii) solid polymer, and (iv) glass-ceramic electrolytes. This article presents the properties, advantages, and limitations of each type of electrolytes. Also, the importance of electrolyte additives on the electrochemical performance of Li–S cells is discussed.

  12. Efficient Electrolytes for Lithium-Sulfur Batteries

    Directory of Open Access Journals (Sweden)

    Natarajan eAngulakshmi

    2015-05-01

    Full Text Available This review article mainly encompasses on the state-of-the-art electrolytes for lithium–sulfur batteries. Different strategies have been employed to address the issues of lithium-sulfur batteries across the world. One among them is identification of electrolytes and optimization of their properties for the applications in lithium-sulfur batteries. The electrolytes for lithium-sulfur batteries are broadly classified as (i non-aqueous liquid electrolytes, (ii ionic liquids, (iii solid polymer and (iv glass-ceramic electrolytes. This article presents the properties, advantages and limitations of each type of electrolytes. Also the importance of electrolyte additives on the electrochemical performance of Li-S cells is discussed.

  13. Efficient Electrolytes for Lithium–Sulfur Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Angulakshmi, Natarajan [Department of Materials Science and Engineering, Politecnico di Torino, Turin (Italy); Stephan, Arul Manuel, E-mail: arulmanuel@gmail.com [Central Electrochemical Research Institute (CSIR-CECRI), Karaikudi (India)

    2015-05-21

    This review article mainly encompasses on the state-of-the-art electrolytes for lithium–sulfur batteries. Different strategies have been employed to address the issues of lithium–sulfur batteries across the world. One among them is identification of electrolytes and optimization of their properties for the applications in lithium–sulfur batteries. The electrolytes for lithium–sulfur batteries are broadly classified as (i) non-aqueous liquid electrolytes, (ii) ionic liquids, (iii) solid polymer, and (iv) glass-ceramic electrolytes. This article presents the properties, advantages, and limitations of each type of electrolytes. Also, the importance of electrolyte additives on the electrochemical performance of Li–S cells is discussed.

  14. Environmental behavior and analysis of agricultural sulfur.

    Science.gov (United States)

    Griffith, Corey M; Woodrow, James E; Seiber, James N

    2015-11-01

    Sulfur has been widely used for centuries as a staple for pest and disease management in agriculture. Presently, it is the largest-volume pesticide in use worldwide. This review describes the sources and recovery methods for sulfur, its allotropic forms and properties and its agricultural uses, including development and potential advantages of nanosulfur as a fungicide. Chemical and microbial reactivity, interactions in soil and water and analytical methods for determination in environmental samples and foodstuffs, including inexpensive analytical methods for sulfur residues in wine, beer and other food/beverage substrates, will be reviewed. The toxicology of sulfur towards humans and agriculturally important fungi is included, with some restrictions on use to promote safety. The review concludes with areas for which more research is warranted. © 2015 Society of Chemical Industry.

  15. Properties of sulfur-extended asphalt concrete

    Directory of Open Access Journals (Sweden)

    Gladkikh Vitaliy

    2016-01-01

    Full Text Available Currently, increased functional reliability of asphalt concrete coatings associated with various modifying additives that improve the durability of pavements. Promising builder is a technical sulfur. Asphalt concrete, made using a complex binder consisting of petroleum bitumen and technical sulfur, were calledsSulfur-Extended Asphalt Concrete. Such asphalt concrete, due to changes in the chemical composition of particulate and bitumen, changes the intensity of the interaction at the interface have increased rates of physical and mechanical properties. There was a lack of essential knowledge concerning mechanical properties of the sulfur-bituminous concrete with such an admixture; therefore, we had carried out the necessary examination. It is revealed that a new material satisfies local regulations in terms of compressive and tensile strength, shear resistance, and internal friction.

  16. Developing porous carbon with dihydrogen phosphate groups as sulfur host for high performance lithium sulfur batteries

    Science.gov (United States)

    Cui, Yanhui; Zhang, Qi; Wu, Junwei; Liang, Xiao; Baker, Andrew P.; Qu, Deyang; Zhang, Hui; Zhang, Huayu; Zhang, Xinhe

    2018-02-01

    Carbon matrix (CM) derived from biomass is low cost and easily mass produced, showing great potential as sulfur host for lithium sulfur batteries. In this paper we report on a dihydrogen phosphate modified CM (PCM-650) prepared from luffa sponge (luffa acutangula) by phosphoric acid treatment. The phosphoric acid not only increases the surface area of the PCM-650, but also introduces dihydrogen phosphate onto PCM-650 (2.28 at% P). Sulfur impregnated (63.6 wt%) PCM-650/S, in comparison with samples with less dihydrogen phosphate LPCM-650/S, shows a significant performance improvement. XPS analysis is conducted for sulfur at different stages, including sulfur (undischarged), polysulfides (discharge to 2.1 V) and short chain sulfides (discharge to 1.7 V). The results consistently show chemical shifts for S2p in PCM-650, suggesting an enhanced adsorption effect. Furthermore, density functional theory (DFT) calculations is used to clarify the molecular binding: carbon/sulfur (0.86 eV), carbon/Li2S (0.3 eV), CH3-O-PO3H2/sulfur (1.24 eV), and CH3-O-PO3H2/Li2S (1.81 eV). It shows that dihydrogen phosphate group can significantly enhance the binding with sulfur and sulfide, consistent with XPS results. Consequently a CM functionalised with dihydrogen phosphate shows great potential as the sulfur host in a Li-S battery.

  17. Sulfur-centered reactive intermediates derived from the oxidation of sulfur compounds of biological interest

    Energy Technology Data Exchange (ETDEWEB)

    Abedinzadeh, Z. [Lab. de Chimie Physique, UMR, Univ. Rene Descartes, Paris (France)

    2001-02-01

    Sulphur compounds play a central role in the structure and activity of many vital systems. In the living cell, sulfur constitutes an essential part of the defense against oxidative damage and is transformed into a variety of sulfur free radical species. Many studies of the chemistry of sulfur-centered radicals using pulse radiolysis and photolysis techniques to detect and measure the kinetics of these radicals have been published and reviewed. This paper discusses the present state of research on the formation and reactivity of certain sulfur-centered radicals [RS{sup .}, RSS{sup .}, RS{sup .+}, (RSSR){sup .+}] and their implications for biological systems. (author)

  18. Sulfur-centered reactive intermediates derived from the oxidation of sulfur compounds of biological interest

    International Nuclear Information System (INIS)

    Abedinzadeh, Z.

    2001-01-01

    Sulphur compounds play a central role in the structure and activity of many vital systems. In the living cell, sulfur constitutes an essential part of the defense against oxidative damage and is transformed into a variety of sulfur free radical species. Many studies of the chemistry of sulfur-centered radicals using pulse radiolysis and photolysis techniques to detect and measure the kinetics of these radicals have been published and reviewed. This paper discusses the present state of research on the formation and reactivity of certain sulfur-centered radicals [RS . , RSS . , RS .+ , (RSSR) .+ ] and their implications for biological systems. (author)

  19. Effect of sulfur dioxide partial pressure on the reaction of iodine, sulfur dioxide and water

    International Nuclear Information System (INIS)

    Nakajima, Hayato; Imai, Yoshiyuki; Kasahara, Seiji; Kubo, Shinji; Onuki, Kaoru

    2007-01-01

    Effect of sulfur dioxide partial pressure on the reaction of iodine, sulfur dioxide and water, which is a unit reaction in the IS process for thermochemical hydrogen production, was studied experimentally at 323 K under iodine saturation. Quasi-equilibrium state was observed in the presence of sulfur dioxide gas at constant pressure. The composition of the poly-hydriodic acid solution formed was discussed assuming an ideal desulfurization by the reverse reaction of the Bunsen reaction. The value of HI/(HI+H 2 O) of the desulfurized solution was large at high sulfur dioxide pressure and reached the maximum of 15.7 ± 0.3 mol%. (author)

  20. Sensing sulfur oxides and other sulfur bearing pollutants with solid electrolyte pellets. I. Gas concentration cells

    Energy Technology Data Exchange (ETDEWEB)

    Chamberland, A M; Gauthier, J M

    1977-01-01

    A new sensing technique using a solid electrolyte has been demonstrated for sulfur-bearing pollutants. Based on potentiometric measurements across a pellet of potassium sulfate, this sensor allows concentrations of sulfur dioxides, sulfur trioxide, hydrogen sulfide, methyl mercaptan and carbonyl sulfide in air to be measured with accuracy. Its operational concentration range at the present time is 0.1 ppM up to at least 10,000 ppM. The presence of other common pollutants such as carbon dioxide, methane, nitric oxide and nitrogen dioxide does not interfere with the measurement of air samples containing sulfur-bearing pollutants.

  1. Mechanical and Electrical Properties of Sulfur-Containing Polymeric Materials Prepared via Inverse Vulcanization

    Directory of Open Access Journals (Sweden)

    Sergej Diez

    2017-02-01

    Full Text Available Recently, new methods have been developed for the utilization of elemental sulfur as a feedstock for novel polymeric materials. One promising method is the inverse vulcanization, which is used to prepare polymeric structures derived from sulfur and divinyl comonomers. However, the mechanical and electrical properties of the products are virtually unexplored. Hence, in the present study, we synthesized a 200 g scale of amorphous, hydrophobic as well as translucent, hyperbranched polymeric sulfur networks that provide a high thermal resistance (>220 °C. The polymeric material properties of these sulfur copolymers can be controlled significantly by varying the monomers as well as the feed content. The investigated comonomers are divinylbenzene (DVB and 1,3-diisopropenylbenzene (DIB. Plastomers with low elastic content and high shape retention containing 12.5%–30% DVB as well as low viscose waxy plastomers with a high flow behavior containing a high DVB content of 30%–35% were obtained. Copolymers with 15%–30% DIB act, on the one hand, as thermoplastics and, on the other hand, as vitreous thermosets with a DIB of 30%–35%. Results of the thermogravimetric analysis (TGA, the dynamic scanning calorimetry (DSC and mechanical characterization, such as stress–strain experiments and dynamic mechanical thermal analysis, are discussed with the outcome that they support the assumption of a polymeric cross-linked network structure in the form of hyper-branched polymers.

  2. Influence of earthworms on the sulfur turnover in the soil.

    Science.gov (United States)

    Grethe, S; Schrader, S; Giesemann, A; Larink, O; Weigel, H J

    1996-08-01

    Abstract The effects of earthworm activity on the concentration and isotopic composition of total sulfur in soils was investigated using batch experiments. Two ecologically different lumbricid species, the anecic Lumbricus terrestris and the endogeic Aporrectodea caliginosa, were used. The earthworms were fed birch leaves, beech leaves, cattle manure or mixed plant litter. All food sources differed isotopically (δ(34)S) from the soil (Parabraunerde). As a reference, one experiment was carried out without additional food. The experimental results show, that both earthworm species influence the total S-content and the δ(34)S-values in the soil by digestion of the different food sources. The differences in the total S-content of the earthworm tissues and in the S-isotopic composition of the casts can be attributed to the ecological differences between the earthworm species.

  3. A Cable-Shaped Lithium Sulfur Battery.

    Science.gov (United States)

    Fang, Xin; Weng, Wei; Ren, Jing; Peng, Huisheng

    2016-01-20

    A carbon nanostructured hybrid fiber is developed by integrating mesoporous carbon and graphene oxide into aligned carbon nanotubes. This hybrid fiber is used as a 1D cathode to fabricate a new cable-shaped lithium-sulfur battery. The fiber cathode exhibits a decent specific capacity and lifespan, which makes the cable-shaped lithium-sulfur battery rank far ahead of other fiber-shaped batteries. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Polymer Electrolytes for Lithium/Sulfur Batteries

    Directory of Open Access Journals (Sweden)

    The Nam Long Doan

    2012-08-01

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

  5. Ocular Effects of Sulfur Mustard

    Directory of Open Access Journals (Sweden)

    Yunes Panahi

    2013-06-01

    Full Text Available Purpose: To review current knowledge about ocular effects of sulfur mustard (SM and the associated histopathologic findings and clinical manifestationsMethods: Literature review of medical articles (human and animal studies was accomplished using PubMed, Scopus and ISI databases. A total of 274 relevant articles in English were retrieved and reviewed thoroughly.Results: Eyes are the most sensitive organs to local toxic effects of mustard gas. Ocular injuries are mediated through different toxic mechanisms including: biochemical damages, biomolecular and gene expression modification, induction of immunologic and inflammatory reactions, disturbing ultrastructural architecture of the cornea, and long-lasting corneal denervation. The resulting ocular injuries can roughly be categorized into acute or chronic complications. Most of the patients recover from acute injuries, but a minority of victims will suffer from chronic ocular complications. Mustard gas keratopathy (MGK is a devastating late complication of SM intoxication that proceeds from limbal stem cell deficiency (LSCD.Conclusion: SM induces several different damaging changes in case of ocular exposure; hence leading to a broad spectrum of ocular manifestations in terms of severity, timing and form. Unfortunately, no effective strategy has been introduced yet to inhibit or restore these damaging changes.

  6. Sulfur mustard and respiratory diseases.

    Science.gov (United States)

    Tang, Feng Ru; Loke, Weng Keong

    2012-09-01

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

  7. Sulfur sources in protein supplements for ruminants

    Directory of Open Access Journals (Sweden)

    Cássio José da Silva

    2014-10-01

    Full Text Available The present study evaluates the efficiency of different sulfur sources for ruminant nutrition. The fiber digestibility and the amino acid profile were analyzed in the duodenal digesta of crossbred steers fed Brachiaria dictyoneurahay. The sources utilized were elemental sulfur (ES70S, elemental sulfur (ES98S; calcium sulfate in hydrated (HCS, CaSO4.2H2O, and anhydrous (ACS, CaSO4, forms; and ammonium sulfate (AS, (NH42SO4, keeping a nitrogen:sulfur ratio of 11:1. The iso-protein supplements had 50% of protein in the total dry matter (DM. Five Holstein × Zebu steers, which were fistulated in the rumen and abomasum, were distributed in a 5 × 5 Latin square. The different sulfur sources in the supplement did not affect any of the evaluated nutritional factors, such as intake of hay dry matter and protein supplement, crude protein (CP, neutral detergent fiber corrected for ash and protein (NDFap, organic matter (OM, non-fibrous carbohydrate (NFC, ether extract (EE, total digestible nutrients (TDN, NDFap and CP digestibility coefficients, ruminal pH, and ruminal ammonia concentration. The concentrations of amino acids available in the abomasal digesta did not differ significantly in the tested diets. The sulfur sources evaluated in the present study are suitable as supplement for cattle, and their employment may be important to avoid environmental contaminations.

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

    Energy Technology Data Exchange (ETDEWEB)

    Zambrzycka, Elżbieta; Godlewska-Żyłkiewicz, Beata, E-mail: bgodlew@uwb.edu.pl

    2014-11-01

    -cysteine in 0.2 mol L{sup −1} HNO{sub 3} solution is proposed as a calibration standard. • Simple, fast and sensitive method for sulfur determination was developed (LOD 10.9 mg L{sup −1}). • The proposed method can be applied for sulfur determination in undigested food samples of diverse sulfur content.

  9. Effects of low sulfur dioxide concentrations on bioactive compounds and antioxidant properties of Aglianico red wine.

    Science.gov (United States)

    Gabriele, Morena; Gerardi, Chiara; Lucejko, Jeannette J; Longo, Vincenzo; Pucci, Laura; Domenici, Valentina

    2018-04-15

    This study analyzed the effect of low sulfur dioxide concentrations on the chromatic properties, phytochemical composition and antioxidant activity of Aglianico red wines with respect to wines produced from conventional winemaking. We determined the phytochemical composition by spectrophotometric methods and HPLC-DAD analysis and the in vitro antioxidant activity of different wine samples by the ORAC assay. The main important classes of fluorophore molecules in red wine were identified by Front-Face fluorescence spectroscopy, and the emission intensity trend was investigated at various sulfur dioxide concentrations. Lastly, we tested the effects of both conventional and low sulfite wines on ex vivo human erythrocytes under oxidative stimulus by the cellular antioxidant activity (CAA) assay and the hemolysis test. The addition of sulfur dioxide, which has well-known side effects, increased the content of certain bioactive components but did not raise the erythrocyte antioxidant capacity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. The determination of sulfur and some heavy elements in the coke

    International Nuclear Information System (INIS)

    Ma'rouf, M.

    2003-01-01

    The content of free sulfur and some heavy elements in the coke resulting from the residua of oil industry was determined bu using various technical analytical methods. The flame technique of atomic absorption FAAS was used to identify lead, copper, zinc, chromium, VGA-AAS and determine arsenic and selenium, CV-AAS to the determination of mercury. As for sulfur, it was determined by using the total oxidation method at high temperatures (1100 C 0 ). The IR indicator was used for further determination. The relative standard deviation in the determination of sulfur did not exceed the limits of 0.01 and 0.02, compared to the determination of other elements by using the atomic absorption method. (Author)

  11. Sulfur restriction extends fission yeast chronological lifespan through Ecl1 family genes by downregulation of ribosome.

    Science.gov (United States)

    Ohtsuka, Hokuto; Takinami, Masahiro; Shimasaki, Takafumi; Hibi, Takahide; Murakami, Hiroshi; Aiba, Hirofumi

    2017-07-01

    Nutritional restrictions such as calorie restrictions are known to increase the lifespan of various organisms. Here, we found that a restriction of sulfur extended the chronological lifespan (CLS) of the fission yeast Schizosaccharomyces pombe. The restriction decreased cellular size, RNA content, and ribosomal proteins and increased sporulation rate. These responses depended on Ecl1 family genes, the overexpression of which results in the extension of CLS. We also showed that the Zip1 transcription factor results in the sulfur restriction-dependent expression of the ecl1 + gene. We demonstrated that a decrease in ribosomal activity results in the extension of CLS. Based on these observations, we propose that sulfur restriction extends CLS through Ecl1 family genes in a ribosomal activity-dependent manner. © 2017 John Wiley & Sons Ltd.

  12. Effect of Sulfur in Steel on Transient Evolution of Inclusions During Calcium Treatment

    Science.gov (United States)

    Liu, Yang; Zhang, Lifeng; Zhang, Ying; Duan, Haojian; Ren, Ying; Yang, Wen

    2018-04-01

    In the current study, the effect of S content in the molten steel on inclusions during calcium treatment was studied using an induction furnace. The calcium in steel decreased from 48 to 2 ppm, and the sulfur in steel changed a little with time. When sulfur content in steel was as low as 25 ppm during calcium treatment, inclusions shifted from CaO-Al2O3-CaS to Al2O3-CaO with about 35 pct CaO. When the sulfur increased over 90 ppm, more CaS-CaO formed just after the addition of calcium, and then the CaS content decreased from over 45 pct to lower than 15 pct and inclusions were mostly Al2O3-CaO-CaS and Al2O3-CaO with a high Al2O3 content. Thermodynamic calculation predicted the variation of the composition of inclusions, indicating good agreement with the measurement, while a certain deviation existed, especially for heats with 90 and 180 ppm sulfur. A reaction model was proposed for the formation of CaO and CaS, which considered the reaction between calcium vapor bubbles in the zone and the dissolved oxygen and sulfur in the molten steel, as described by a Langmuir-type adsorption isotherm with a reaction occurring on the remaining vacant sites. The variation of transient CaS inclusions was discussed based on the thermodynamic calculation and the morphology evolution of typical inclusions containing CaS.

  13. Acidithiobacillus caldus sulfur oxidation model based on transcriptome analysis between the wild type and sulfur oxygenase reductase defective mutant.

    Directory of Open Access Journals (Sweden)

    Linxu Chen

    Full Text Available Acidithiobacillus caldus (A. caldus is widely used in bio-leaching. It gains energy and electrons from oxidation of elemental sulfur and reduced inorganic sulfur compounds (RISCs for carbon dioxide fixation and growth. Genomic analyses suggest that its sulfur oxidation system involves a truncated sulfur oxidation (Sox system (omitting SoxCD, non-Sox sulfur oxidation system similar to the sulfur oxidation in A. ferrooxidans, and sulfur oxygenase reductase (SOR. The complexity of the sulfur oxidation system of A. caldus generates a big obstacle on the research of its sulfur oxidation mechanism. However, the development of genetic manipulation method for A. caldus in recent years provides powerful tools for constructing genetic mutants to study the sulfur oxidation system.An A. caldus mutant lacking the sulfur oxygenase reductase gene (sor was created and its growth abilities were measured in media using elemental sulfur (S(0 and tetrathionate (K(2S(4O(6 as the substrates, respectively. Then, comparative transcriptome analysis (microarrays and real-time quantitative PCR of the wild type and the Δsor mutant in S(0 and K(2S(4O(6 media were employed to detect the differentially expressed genes involved in sulfur oxidation. SOR was concluded to oxidize the cytoplasmic elemental sulfur, but could not couple the sulfur oxidation with the electron transfer chain or substrate-level phosphorylation. Other elemental sulfur oxidation pathways including sulfur diooxygenase (SDO and heterodisulfide reductase (HDR, the truncated Sox pathway, and the S(4I pathway for hydrolysis of tetrathionate and oxidation of thiosulfate in A. caldus are proposed according to expression patterns of sulfur oxidation genes and growth abilities of the wild type and the mutant in different substrates media.An integrated sulfur oxidation model with various sulfur oxidation pathways of A. caldus is proposed and the features of this model are summarized.

  14. Corrosion by concentrated sulfuric acid in carbon steel pipes and tanks: state of the art

    Energy Technology Data Exchange (ETDEWEB)

    Panossian, Zehbour; Almeida, Neusvaldo Lira de; Sousa, Raquel Maria Ferreira de [Instituto de Pesquisas Tecnologicas (IPT), Sao Paulo, SP (Brazil); Pimenta, Gutemberg de Souza [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas e Desenvolvimento (CENPES); Marques, Leandro Bordalo Schmidt [PETROBRAS Engenharia, Rio de Janeiro, RJ (Brazil)

    2009-07-01

    PETROBRAS, allied to the policy of reduction of emission of pollutants, has been adjusting the processes of the new refineries to obtain products with lower sulfur content. Thus, the sulfur dioxide, extracted from the process gases of a new refinery to be built in the Northeast, will be used to produce sulfuric acid with concentration between (94-96) %. This acid will be stored in carbon steel tanks and transported through a buried 8-km carbon steel pipe from the refinery to a pier, where it will be loaded onto ships and sent to the consumer markets. Therefore, the corrosion resistance of carbon steel by concentrated acid will become a great concern for the mentioned storage and transportation. When the carbon steel comes into contact with concentrated sulfuric acid, there is an immediate acid attack with the formation of hydrogen gas and ferrous ions which, in turn, forms a protective layer of FeSO{sub 4} on the metallic surface. The durability of the tanks and pipes made of carbon steel will depend on the preservation of this protective layer. This work presents a review of the carbon steel corrosion in concentrated sulfuric acid and discusses the preventive methods against this corrosion, including anodic protection. (author)

  15. Sulfuric acid nucleation: power dependencies, variation with relative humidity, and effect of bases

    Directory of Open Access Journals (Sweden)

    J. H. Zollner

    2012-05-01

    Full Text Available Nucleation of particles composed of sulfuric acid, water, and nitrogen base molecules was studied using a continuous flow reactor. The particles formed from these vapors were detected with an ultrafine condensation particle counter, while vapors of sulfuric acid and nitrogen bases were detected by chemical ionization mass spectrometry. Variation of particle numbers with sulfuric acid concentration yielded a power dependency on sulfuric acid of 5 ± 1 for relative humidities of 14–68% at 296 K; similar experiments with varying water content yielded power dependencies on H2O of ~7. The critical cluster contains about 5 H2SO4 molecules and a new treatment of the power dependency for H2O suggests about 12 H2O molecules for these conditions. Addition of 2-to-45 pptv of ammonia or methyl amine resulted in up to millions of times more particles than in the absence of these compounds. Particle detection capabilities, sulfuric acid and nitrogen base detection, wall losses, and the extent of particle growth are discussed. Results are compared to previous laboratory nucleation studies and they are also discussed in terms of atmospheric nucleation scenarios.

  16. Capital cost: high and low sulfur coal plants-1200 MWe. [High sulfur coal

    Energy Technology Data Exchange (ETDEWEB)

    1977-01-01

    This Commercial Electric Power Cost Study for 1200 MWe (Nominal) high and low sulfur coal plants consists of three volumes. The high sulfur coal plant is described in Volumes I and II, while Volume III describes the low sulfur coal plant. The design basis and cost estimate for the 1232 MWe high sulfur coal plant is presented in Volume I, and the drawings, equipment list and site description are contained in Volume II. The reference design includes a lime flue gas desulfurization system. A regenerative sulfur dioxide removal system using magnesium oxide is also presented as an alternate in Section 7 Volume II. The design basis, drawings and summary cost estimate for a 1243 MWe low sulfur coal plant are presented in Volume III. This information was developed by redesigning the high sulfur coal plant for burning low sulfur sub-bituminous coal. These coal plants utilize a mechanical draft (wet) cooling tower system for condenser heat removal. Costs of alternate cooling systems are provided in Report No. 7 in this series of studies of costs of commercial electrical power plants.

  17. The life sulfuric: microbial ecology of sulfur cycling in marine sediments.

    Science.gov (United States)

    Wasmund, Kenneth; Mußmann, Marc; Loy, Alexander

    2017-08-01

    Almost the entire seafloor is covered with sediments that can be more than 10 000 m thick and represent a vast microbial ecosystem that is a major component of Earth's element and energy cycles. Notably, a significant proportion of microbial life in marine sediments can exploit energy conserved during transformations of sulfur compounds among different redox states. Sulfur cycling, which is primarily driven by sulfate reduction, is tightly interwoven with other important element cycles (carbon, nitrogen, iron, manganese) and therefore has profound implications for both cellular- and ecosystem-level processes. Sulfur-transforming microorganisms have evolved diverse genetic, metabolic, and in some cases, peculiar phenotypic features to fill an array of ecological niches in marine sediments. Here, we review recent and selected findings on the microbial guilds that are involved in the transformation of different sulfur compounds in marine sediments and emphasise how these are interlinked and have a major influence on ecology and biogeochemistry in the seafloor. Extraordinary discoveries have increased our knowledge on microbial sulfur cycling, mainly in sulfate-rich surface sediments, yet many questions remain regarding how sulfur redox processes may sustain the deep-subsurface biosphere and the impact of organic sulfur compounds on the marine sulfur cycle. © 2017 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

  18. Quantification of Discrete Oxide and Sulfur Layers on Sulfur-Passivated InAs by XPS

    National Research Council Canada - National Science Library

    Petrovykh, D. Y; Sullivan, J. M; Whitman, L. J

    2005-01-01

    .... The S-passivated InAs(001) surface can be modeled as a sulfur-indium-arsenic layer-cake structure, such that characterization requires quantification of both arsenic oxide and sulfur layers that are at most a few monolayers thick...

  19. Sulfur Isotope Exchange between S-35 Labeled Inorganic Sulfur-Compounds in Anoxic Marine-Sediments

    DEFF Research Database (Denmark)

    FOSSING, H.; THODEANDERSEN, S.; JØRGENSEN, BB

    1992-01-01

    of isotope exchange, specific radioactivities of the reduced sulfur pools were poorly defined and could not be used to calculate their rates of formation. Such isotope exchange reactions between the reduced inorganic sulfur compounds will affect the stable isotope distribution and are expected to decrease...

  20. 40 CFR 52.1881 - Control strategy: Sulfur oxides (sulfur dioxide).

    Science.gov (United States)

    2010-07-01

    ....0 pounds of sulfur dioxide per million BTU actual heat input for the coal-fired boiler and 0.4... BTU actual heat input for coal-fired boiler C exiting through stack 5. (3) 2.24 pounds of sulfur dioxide per million BTU acutal heat input for coal-fired boiler D exiting through stack 6. (E) In lieu of...

  1. Sulfur and Oxygen Isotope Fractionation During Bacterial Sulfur Disproportionation Under Anaerobic Haloalkaline Conditions

    NARCIS (Netherlands)

    Poser, Alexander; Vogt, Carsten; Knöller, Kay; Sorokin, Dimitry Y.; Finster, Kai W.; Richnow, Hans H.

    2016-01-01

    Sulfur and oxygen isotope fractionation of elemental sulfur disproportionation at anaerobic haloalkaline conditions was evaluated for the first time. Isotope enrichment factors of the strains Desulfurivibrio alkaliphilus and Dethiobacter alkaliphilus growing at pH 9 or 10 were −0.9‰ to −1‰ for

  2. Genomic Insights into the Sulfur Metabolism of Phototrophic Green Sulfur Bacteria

    DEFF Research Database (Denmark)

    Frigaard, Niels-Ulrik; Bryant, Donald A.

    2008-01-01

    Green sulfur bacteria (GSB) utilize various combinations of sulfide, elemental sulfur, thiosulfate, ferrous iron, and hydrogen for anaerobic photoautotrophic growth. Genome sequence data is currently available for 12 strains of GSB. We present here a genome-based survey of the distribution...... and phylogenies of genes involved in oxidation of sulfur compounds in these strains. Sulfide:quinone reductase, encoded by sqr, is the only known sulfur-oxidizing enzyme found in all strains. All sulfide-utilizing strains contain the dissimilatory sulfite reductase dsrABCEFHLNMKJOPT genes, which appear...... to be involved in elemental sulfur utilization. All thiosulfate-utilizing strains have an identical sox gene cluster (soxJXYZAKBW). The soxCD genes found in certain other thiosulfate-utilizing organisms like Paracoccus pantotrophus are absent from GSB. Genes encoding flavocytochrome c (fccAB), adenosine-5...

  3. The partitioning of sulfur between multicomponent aqueous fluids and felsic melts

    Science.gov (United States)

    Binder, Bernd; Wenzel, Thomas; Keppler, Hans

    2018-02-01

    Sulfur partitioning between melt and fluid phase largely controls the environmental impact of volcanic eruptions. Fluid/melt partitioning data also provide the physical basis for interpreting changes in volcanic gas compositions that are used in eruption forecasts. To better constrain some variables that control the behavior of sulfur in felsic systems, in particular the interaction between different volatiles, we studied the partitioning of sulfur between aqueous fluids and haplogranitic melts at 200 MPa and 750-850 °C as a function of oxygen fugacity (Ni-NiO or Re-ReO2 buffer), melt composition (Al/(Na + K) ratio), and fluid composition (NaCl and CO2 content). The data confirm a first-order influence of oxygen fugacity on the partitioning of sulfur. Under "reducing conditions" (Ni-NiO buffer), D fluid/melt is nearly one order of magnitude larger (323 ± 14 for a metaluminous melt) than under "oxidizing conditions" (Re-ReO2 buffer; 74 ± 5 for a metaluminous melt). This effect is likely related to a major change in sulfur speciation in both melt and fluid. Raman spectra of the quenched fluids show the presence of H2S and HS- under reducing conditions and of SO4 2- and HSO4 - under oxidizing conditions, while SO2 is undetectable. The latter observation suggests that already at the Re-ReO2 buffer, sulfur in the fluid is almost completely in the S6+ state and, therefore, more oxidized than expected according to current models. CO2 in the fluid (up to x CO2 = 0.3) has no effect on the fluid/melt partitioning of sulfur, neither under oxidizing nor under reducing conditions. However, the effect of NaCl depends on redox state. While at oxidizing conditions, D fluid/melt is independent of x NaCl, the fluid/melt partition coefficient strongly decreases with NaCl content under reducing conditions, probably due to a change from H2S to NaSH as dominant sulfur species in the fluid. A decrease of D fluid/melt with alkali content in the melt is observed over the entire

  4. The effective synthesis of Insoluble sulfur using electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Daejin; Yu, Kookhyun [Dongguk Univ., Seoul (Korea, Republic of)

    2013-07-01

    Vulcanization is process that formed crosslinking by Insoluble sulfur between linear structure of rubber polymer. Recently, Synthesis of Insoluble sulfur is used Thermal polymerization using about 250 {approx} 300 .deg. C and extraction process is used carbon disulfide(CS2) for separation between soluble sulfur and insoluble sulfur. But this process isn't environmental, economical and safety. This research was focus on developing of insoluble sulfur synthesis process using electron beam. This new process is using under the 140 .deg. C. Because of that, explosion risk is decrease, environmental and economical factor is increased. The sulfur can be melt by increase temperature or made solution using carbon disulfide. And electron beam is irradiated melting sulfur or sulfur solution. After irradiation, The high purity insoluble sulfur can be obtained by separation with carbon disulfide.

  5. A primer on sulfur for the planetary geologist

    Science.gov (United States)

    Theilig, E.

    1982-01-01

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

  6. Clues to early diagenetic sulfurization processes from mild chemical cleavage of labile sulfur-rich geomacromolecules

    Science.gov (United States)

    Adam, P.; Schneckenburger, P.; Schaeffer, P.; Albrecht, P.

    2000-10-01

    Macromolecular fractions, isolated from the solvent extract of sulfur-rich Recent (Siders Pond, USA; Lake Cadagno, Switzerland; Walvis Bay, Namibia) and immature sediments (Gibellina, Messinian of Sicily; Vena del Gesso, Messinian of Italy), were investigated by chemical degradation using sodium ethanethiolate/methyliodide. This mild reagent which cleaves polysulfide bonds to yield methylsulfides has the advantage over other methods of leaving intact other functionalities (like double bonds) and preserving sulfur atoms at their incorporation site. The method is, therefore, well-suited to the molecular level investigation of sulfur-rich macromolecules from Recent sediments containing highly functionalized polysulfide-bound subunits. In Recent anoxic sulfur-rich sediments, the release of various methylthioethers clearly demonstrates that intermolecular sulfurization of organic matter does occur at the earliest stages of diagenesis. Steroids and phytane derivatives are the major sulfurized lipids, a feature also observed in more mature sulfur-rich sediments. Several phytene derivatives, such as cis and trans 1-methylthiophyt-2-enes, as well as methylthiosteroids, including 5α- and 5β-3-(methylthio)-cholest-2-enes, were identified by comparison with synthesized standards. Steroid methylthioenolethers are released from polysulfide-bound steroid enethiols present in the macromolecular fractions. The latter, which correspond to thioketones, can be considered as intermediates in the reductive sulfurization pathway leading from steroid ketones to polysulfide-bound saturated steroid skeletons and are characterized for the first time in the present study. Thus, it could be shown that the major part of the polysulfide-bound lipids occurring in Recent sediments is apparently the result of sulfurization processes affecting carbonyls (aldehydes and ketones). The unsaturated methylthioethers obtained from Recent sediments were not present in more mature evaporitic samples, which

  7. Self-assembled peptides for coating of active sulfur nanoparticles in lithium–sulfur battery

    International Nuclear Information System (INIS)

    Jewel, Yead; Yoo, Kisoo; Liu, Jin; Dutta, Prashanta

    2016-01-01

    Development of lithium–sulfur (Li–S) battery is hindered by poor cyclability due to the loss of sulfur, although Li–S battery can provide high energy density. Coating of sulfur nanoparticles can help maintain active sulfur in the cathode of Li–S battery, and hence increase the cyclability. Among myriad of coating materials, synthetic peptides are very attractive because of their spontaneous self-assembly as well as electrical conductive characteristics. In this study, we explored the use of various synthetic peptides as a coating material for sulfur nanoparticles. Atomistic simulations were carried out to identify optimal peptide structure and density for coating sulfur nanoparticles. Three different peptide models, poly-proline, poly(leucine–lysine) and poly-histidine, are selected for this study based on their peptide–peptide and peptide-sulfur interactions. Simulation results show that both poly-proline and poly(leucine–lysine) can form self-assembled coating on sulfur nanoparticles (2–20 nm) in pyrrolidinone, a commonly used solvent for cathode slurry. We also studied the structural integrity of these synthetic peptides in organic [dioxolane (DOL) and dimethoxyethane (DME)] electrolyte used in Li–S battery. Both peptides show stable structures in organic electrolyte (DOL/DME) used in Li–S battery. Furthermore, the dissolution of sulfur molecules in organic electrolyte is investigated in the absence and presence of these peptide coatings. It was found that only poly(leucine–lysine)-based peptide can most effectively suppress the sulfur loss in electrolyte, suggesting its potential applications in Li–S battery as a coating material.Graphical abstract

  8. Sulfur deactivation of fatty ester hydrogenolysis catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Brands, D.S.; U-A-Sai, G.; Poels, E.K.; Bliek, A. [Univ. of Amsterdam (Netherlands). Dept. of Chemical Engineering

    1999-08-15

    Trace organosulfur compounds present as natural impurities in oleochemical feedstocks may lead to activation of copper-containing catalysts applied for hydrogenolysis of esters toward fatty alcohols. In this paper, the sulfur deactivation of Cu/SiO{sub 2} and Cu/ZnO/SiO{sub 2} catalysts was studied in the liquid-phase hydrogenolysis of methyl palmitate. The rate of deactivation is fast and increases as a function of the sulfur-containing compound present: octadecanethiol {approx} dihexadecyl disulfide < benzyl isothiocyanate < methyl p-toluene sulfonate < dihexadecyl sulfide < dibenzothiophene. The rapid deactivation is caused by the fact that sulfur is quantitatively removed from the reaction mixture and because mainly surface sulfides are formed under hydrogenolysis conditions. The life time of a zinc-promoted catalyst is up to two times higher than that of the Cu/SiO{sub 2} catalyst, most likely due to zinc surface sulfide formation. The maximum sulfur coverage obtained after full catalyst deactivation with dibenzothiophene and dihexadecyl sulfide--the sulfur compounds that cause the fastest deactivation--may be as low as 0.07. This is due to the fact that decomposition of these compounds as well as the hydrogenolysis reaction itself proceeds on ensembles of copper atoms. Catalyst regeneration studies reveal that activity cannot be regained by reduction or combined oxidation/reduction treatments. XRD, TPR, and TPO results confirm that no distinct bulk copper or zinc sulfide or sulfate phases are present.

  9. Digestion of Bangka monazite with sulfuric acid

    International Nuclear Information System (INIS)

    Riesna Prassanti

    2012-01-01

    Technology of Bangka monazite processing with alkaline method has been mastered by PPGN BATAN with the product in the form of RE (Rare Earth) which is contain U < 2 ppm and Th 12 - 16 ppm. Hence, as comparator, the research of Bangka monazite processing with acid method using sulfuric acid has been done. The aim of this research is to obtain the optimal condition of Bangka monazite's digestion using sulfuric acid so that all elements contained in the monazite that are U, Th, RE, PO 4 dissolved as much as possible. The research parameter's arc monazite particle's size, sulfuric acid consumption (weight ratio of monazite ore : sulfuric acid), digestion temperature, digestion time and consumption of wash water. The results showed that the optimal conditions of digestion are 250+ 325 mesh of monazite particle's size, 1 : 2.5 of weight ratio of monazite ore: sulfuric acid, 190°C of digestion temperature, 3 hours of digestion time and 8 times of weight monazite's feed of wash water with the recovery of digested U = 99.90 %, Th = 99.44 %, RE = 98.64 % and PO 4 = 99.88 %. (author)

  10. Deposition and Tribological Properties of Sulfur-Doped DLC Films Deposited by PBII Method

    Directory of Open Access Journals (Sweden)

    Nutthanun Moolsradoo

    2010-01-01

    Full Text Available Sulfur-doped diamond-like carbon films (S-DLC fabricated from C2H2 and SF6 mixtures were used to study the effects of sulfur content and negative pulse bias voltage on the deposition and tribological properties of films prepared by plasma-based ion implantation (PBII. The structure and relative concentration of the films were analyzed by Raman spectroscopy and Auger electron spectroscopy. Hardness and elastic modulus of films were measured by nanoindentation hardness testing. Tribological characteristics of films were performed using a ball-on-disk friction tester. The results indicate that with the increasing sulfur content, the hardness and elastic modulus decrease. Additionally, by changing the negative pulse bias voltage from 0 kV to −5 kV, the hardness and elastic modulus increase, while the friction coefficient and specific wear rate tends to decrease. Moreover, at a negative pulse bias voltage of −5 kV and flow-rate ratio of 1 : 2, there is considerable improvement in friction coefficient of 0.05 under ambient air is due to the formation of a transfer films on the interface. The decrease in the friction coefficient of films doped with 4.9 at.% sulfur is greater under high vacuum (0.03 than under ambient air (>0.1.

  11. Modeling the condensation of sulfuric acid and water on the cylinder liner of a large two-stroke marine diesel engine

    DEFF Research Database (Denmark)

    Cordtz, Rasmus Faurskov; Mayer, Stefan; Eskildsen, Svend S.

    2018-01-01

    Corrosive wear of cylinder liners in large two-stroke marine diesel engines that burn heavy fuel oil containing sulfur is coupled to the formation of gaseous sulfur trioxide (SO3) and subsequent combined condensation of sulfuric acid (H2SO4) and water (H2O) vapor. The present work seeks to address...... vapor liquid equilibrium. By assuming homogenous cylinder gas mixtures condensation is modeled using a convective heat and mass transfer analogy combined with realistic liner temperature profiles. Condensation of water is significantly altered by the liner temperature and charge air humidity while...... how fuel sulfur content, charge air humidity and liner temperature variations affects the deposition of water and sulfuric acid at low load operation. A phenomenological engine model is applied to simulate the formation of cylinder/bulk gas combustion products and dew points comply with H2O–H2SO4...

  12. Long-Life Lithium-Sulfur Battery Derived from Nori-Based Nitrogen and Oxygen Dual-Doped 3D Hierarchical Biochar.

    Science.gov (United States)

    Wu, Xian; Fan, Lishuang; Wang, Maoxu; Cheng, Junhan; Wu, Hexian; Guan, Bin; Zhang, Naiqing; Sun, Kening

    2017-06-07

    Due to restrictions on the low conductivity of sulfur and soluble polysulfides during discharge, lithium sulfur batteries are unsuitable for further large scale applications. The current carbon based cathodes suffer from poor cycle stability and high cost. Recently, heteroatom doped carbons have been considered as a settlement to enhance the performance of lithium sulfur batteries. With this strategy, we report the low cost activated nori based N,O-doped 3D hierarchical carbon material (ANC) as a sulfur host. The N,O dual-doped ANC reveals an elevated electrochemical performance, which exhibits not only a good rate performance over 5 C, but also a high sulfur content of 81.2%. Further importantly, the ANC represents an excellent cycling stability, the cathode reserves a capacity of 618 mAh/g at 2 C after 1000 cycles, which shows a 0.022% capacity decay per cycle.

  13. Late Pleistocene to Holocene environmental changes as recorded in the sulfur geochemistry of coastal plain sediments, southwestern Taiwan

    Science.gov (United States)

    Chen, Y.-G.; Liu, J.C.-L.; Shieh, Y.-N.; Liu, T.-K.

    2004-01-01

    A core, drilled at San-liao-wan in the southwestern coastal plain of Taiwan, has been analyzed for total sulfur contents, isotopic values, as well as ratios of pyritic sulfur to organic carbon. Our results demonstrate a close relationship between late Pleistocene sea-level change and the proxies generated in this study. The inorganic sulfur contents indicate that at our study site, the Holocene transgression started at ???11 ka and remained under seawater for thousands of years until the late Holocene, corresponding to a depth of 20 m in the study core. The uppermost 20 m of core shows relatively high total organic carbon (TOC) and ??34S of inorganic sulfur, suggesting a transitional environment such as muddy lagoon or marsh, before the site turned into a modern coastal plain. In the lower part of the core, at depths of 110-145 m (corresponding ages of ???12-30 ka), low sulfur contents are recorded, probably indicating fluvial sediments deposited during the oceanic isotope stage (OIS) 2, a sea-level lowstand. The lower part of the core, roughly within OIS 3, records at least two transgressions, although the transgressional signals may be somewhat obscured by subsequent weathering. The reworked origin of organic matter reported in previous studies is confirmed by our organic sulfur data; however, the marine organic source was periodically dominant. The modern high sulfate concentrations in pore water have no correlation to the other sulfur species in the sediments, probably indicating that the sulfate migrated into the site subsequent to early diagenesis. ?? 2003 Elsevier Ltd. All rights reserved.

  14. Corrosion evaluation of materials in sulfur compound environments

    International Nuclear Information System (INIS)

    Maoying Teng; Iuanjou Yang

    1993-01-01

    The para-toluene sulfonic acid (PTSA) serves as a catalyst in producing diethylene glycol dibenzoate (DEGDB) and decomposes with increasing time at elevated temperature. Due to the presence of bisulfite ion, it is important to evaluate the corrosion properties of materials in this metastable environments. A potentiodynamic method was used to screen materials' properties in a PTSA solution. A surface analysis technique was also performed to investigate the oxide films. The critical current density and passive current density were substantially reduced when Fe alloyed with Cr and/or Ni. With the addition of Mo in Fe-Ni-Cr alloys, the critical current density was lowered further to show the beneficial effect of alloyed Mo. A plot of the corrosion rate of materials in DEGDB as a function of Ni/Cr ratio shows the linearity with increasing Ni/Cr ratio, disregard the type of materials. The corrosion rate of pure chromium can be estimated as ∼ 2.0 mpy by extrapolation of the linearity to Ni/Cr = 0. This is also the minimum corrosion rate that even Fe-Ni-Cr alloys were alloyed with Mo. Surface analysis results showed that the dissolution of Fe and/or Ni leads to a higher surface chromium content and results in the formation of chromium oxide on metal surface. This chromium oxide then prevents metal from corrosion. It is concluded that the higher the nickel content the higher the corrosion rate of materials. The composition potential-pH diagrams for Fe-S-H 2 O and Ni-S-H 2 O show that the stability fields of FeS and NiS cover a wide range of pH. The effect of sulfur or sulfide ions in promoting dissolution of Fe and/or Ni are highly possible. The activating influence of sulfur compounds on Ni is stronger than that of Fe, although the highly electronic conductivity of iron sulfides can catalyze the cathodic reaction. Undoubtedly, sulfur compound strongly depassivates high Ni contents materials

  15. Microbial ecology of soda lakes: investigating sulfur and nitrogen cycling at Mono Lake, CA, USA

    Science.gov (United States)

    Fairbanks, D.; Phillips, A. A.; Wells, M.; Bao, R.; Fullerton, K. M.; Stamps, B. W.; Speth, D. R.; Johnson, H.; Sessions, A. L.

    2017-12-01

    Soda lakes represent unique ecosystems characterized by extremes of pH, salinity and distinct geochemical cycling. Despite these extreme conditions, soda lakes are important repositories of biological adaptation and have a highly functional microbial system. We investigated the biogeochemical cycling of sulfur and nitrogen compounds in Mono Lake, California, located east of the Sierra Nevada mountains. Mono lake is characterized by hyperalkaline, hypersaline and high sulfate concentrations and can enter prolonged periods of meromixis due to freshwater inflow. Typically, the microbial sulfur cycle is highly active in soda lakes with both oxidation and reduction of sulfur compounds. However, the biological sulfur cycle is connected to many other main elemental cycles such as carbon, nitrogen and metals. Here we investigated the interaction between sulfur and nitrogen cycling in Mono lake using a combination of molecular, isotopic, and geochemical observations to explore the links between microbial phylogenetic composition and functionality. Metagenomic and 16S rRNA gene amplicon sequencing were determined at two locations and five depths in May 2017. 16S rRNA gene amplicon sequencing analysis revealed organisms capable of both sulfur and nitrogen cycling. The relative abundance and distribution of functional genes (dsrA, soxAB, nifH, etc) were also determined. These genetic markers indicate the potential in situ relevance of specific carbon, nitrogen, and sulfur pathways in the water column prior to the transition to meromictic stratification. However, genes for sulfide oxidation, denitrification, and ammonification were present. Genome binning guided by the most abundant dsrA sequences, GC content, and abundance with depth identified a Thioalkalivibrio paradoxus bin containing genes capable of sulfur oxidation, denitrification, and nitrate reduction. The presence of a large number of sulfur and nitrogen cycling genes associated with Thioalkalivibrio paradoxus

  16. Evolution of sulfur speciation in bitumen through hydrous pyrolysis induced thermal maturation of Jordanian Ghareb Formation oil shale

    Science.gov (United States)

    Birdwell, Justin E.; Lewan, Michael; Bake, Kyle D.; Bolin, Trudy B.; Craddock, Paul R.; Forsythe, Julia C.; Pomerantz, Andrew E.

    2018-01-01

    Previous studies on the distribution of bulk sulfur species in bitumen before and after artificial thermal maturation using various pyrolysis methods have indicated that the quantities of reactive (sulfide, sulfoxide) and thermally stable (thiophene) sulfur moieties change following consistent trends under increasing thermal stress. These trends show that sulfur distributions change during maturation in ways that are similar to those of carbon, most clearly illustrated by the increase in aromatic sulfur (thiophenic) as a function of thermal maturity. In this study, we have examined the sulfur moiety distributions of retained bitumen from a set of pre- and post-pyrolysis rock samples in an organic sulfur-rich, calcareous oil shale from the Upper Cretaceous Ghareb Formation. Samples collected from outcrop in Jordan were subjected to hydrous pyrolysis (HP). Sulfur speciation in extracted bitumens was examined using K-edge X-ray absorption near-edge structure (XANES) spectroscopy. The most substantial changes in sulfur distribution occurred at temperatures up to the point of maximum bitumen generation (∼300 °C) as determined from comparison of the total organic carbon content for samples before and after extraction. Organic sulfide in bitumen decreased with increasing temperature at relatively low thermal stress (200–300 °C) and was not detected in extracts from rocks subjected to HP at temperatures above around 300 °C. Sulfoxide content increased between 200 and 280 °C, but decreased at higher temperatures. The concentration of thiophenic sulfur increased up to 300 °C, and remained essentially stable under increasing thermal stress (mg-S/g-bitumen basis). The ratio of stable-to-reactive+stable sulfur moieties ([thiophene/(sulfide+sulfoxide+thiophene)], T/SST) followed a sigmoidal trend with HP temperature, increasing slightly up to 240 °C, followed by a substantial increase between 240 and 320 °C, and approaching a constant value (∼0.95) at

  17. Anthropogenic sulfur dioxide emissions: 1850–2005

    Directory of Open Access Journals (Sweden)

    S. J. Smith

    2011-02-01

    Full Text Available Sulfur aerosols impact human health, ecosystems, agriculture, and global and regional climate. A new annual estimate of anthropogenic global and regional sulfur dioxide emissions has been constructed spanning the period 1850–2005 using a bottom-up mass balance method, calibrated to country-level inventory data. Global emissions peaked in the early 1970s and decreased until 2000, with an increase in recent years due to increased emissions in China, international shipping, and developing countries in general. An uncertainty analysis was conducted including both random and systemic uncertainties. The overall global uncertainty in sulfur dioxide emissions is relatively small, but regional uncertainties ranged up to 30%. The largest contributors to uncertainty at present are emissions from China and international shipping. Emissions were distributed on a 0.5° grid by sector for use in coordinated climate model experiments.

  18. Conductive framework of inverse opal structure for sulfur cathode in lithium-sulfur batteries.

    Science.gov (United States)

    Jin, Lu; Huang, Xiaopeng; Zeng, Guobo; Wu, Hua; Morbidelli, Massimo

    2016-09-07

    As a promising cathode inheritor for lithium-ion batteries, the sulfur cathode exhibits very high theoretical volumetric capacity and energy density. In its practical applications, one has to solve the insulating properties of sulfur and the shuttle effect that deteriorates cycling stability. The state-of-the-art approaches are to confine sulfur in a conductive matrix. In this work, we utilize monodisperse polystyrene nanoparticles as sacrificial templates to build polypyrrole (PPy) framework of an inverse opal structure to accommodate (encapsulate) sulfur through a combined in situ polymerization and melting infiltration approach. In the design, the interconnected conductive PPy provides open channels for sulfur infiltration, improves electrical and ionic conductivity of the embedded sulfur, and reduces polysulfide dissolution in the electrolyte through physical and chemical adsorption. The flexibility of PPy and partial filling of the inverse opal structure endure possible expansion and deformation during long-term cycling. It is found that the long cycling stability of the cells using the prepared material as the cathode can be substantially improved. The result demonstrates the possibility of constructing a pure conductive polymer framework to accommodate insulate sulfur in ion battery applications.

  19. Confine sulfur in mesoporous metal–organic framework @ reduced graphene oxide for lithium sulfur battery

    International Nuclear Information System (INIS)

    Bao, Weizhai; Zhang, Zhian; Qu, Yaohui; Zhou, Chengkun; Wang, Xiwen; Li, Jie

    2014-01-01

    Highlights: • Metal organic framework @ reduced graphene oxide was applied for sulfur cathode. • MIL-101(Cr)@rGO/S composites are synthesized by a facile two-step liquid method. • Cycling stability of MIL-101(Cr)@rGO/S sulfur cathode was improved. -- Abstract: Mesoporous metal organic framework @ reduced graphene oxide (MIL-101(Cr)@rGO) materials have been used as a host material to prepare the multi-composite sulfur cathode through a facile and effective two-step liquid phase method successfully, which is different from the simple MIL-101(Cr)/S mixed preparation method. The successful reduced graphene oxide coating in the MIL-101(Cr)@rGO improve the electronic conductivity of meso-MOFs effectively. The discharge capacity and capacity retention rate of MIL-101(Cr)@rGO/S composite sulfur cathode are as high as 650 mAh g −1 and 66.6% at the 50th cycle at the current density of 335 mA g −1 . While the discharge capacity and capacity retention rate of MIL-101(Cr)/S mixed sulfur cathode is 458 mAh g −1 and 37.3%. Test results indicate that the MIL-101(Cr)@rGO is a promising host material for the sulfur cathode in the lithium–sulfur battery applications

  20. Extraction of sulfuric acid with TOPO

    International Nuclear Information System (INIS)

    Shuyun, Xue; Yonghui, Yang; Yanzhao, Yang; Sixiu, Sun; Borong, Bao

    1998-01-01

    A study on solvent extraction of sulfuric acid by tri-octylphosphine oxide (TOPO) in n-heptane has been made. Extraction coefficients of H 2 SO 4 as a function of H 2 SO 4 concentration in aqueous phase, and extractant concentrations in organic phase have been studied. The composition of extracted species, equilibrium constants of extraction reaction have been evaluated. These results are important for interpreting extraction equilibrium data of uranium(VI) or other metal ions with TOPO in sulfuric acid media. (author)

  1. Method of making a sodium sulfur battery

    Science.gov (United States)

    Elkins, Perry E.

    1981-01-01

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

  2. EFFECT OF SOIL SULFUR FERTILIZER AND SOME FOLIAR FERTILIZERS ON GROWTH AND YIELD OF BROCCOLI IN SALINE SOIL

    Directory of Open Access Journals (Sweden)

    Ali Husain JASIM

    2015-12-01

    Full Text Available Factorial experiment was conducted in the open fields of Agricultural College, Al-Qasim Green University during the agricultural seasons of 2013/2014 and 2014/2015 to study the effect of adding two levels of agricultural sulfur (control and add 100 kg.ha-1 and four levels of nutrient spray (without spray, high-potash fertilizer, high-phosphorus fertilizer and humic acid on growth and yield of broccoli under drip irrigation and polyethylene soil mulching in saline soil (9.6 dS.m-1. Randomized complete block design with three replicates was used. The results showed that agricultural sulfur led to increase number of leaves, leaf area, leaves chlorophyll content, diameter and weight of flower head compared to control. Spraying foliar fertilizer and its interaction with sulfur fertilizer also led to increase all of parameters above (except leaves chlorophyll content significantly compared to control treatment.

  3. Quantitative analysis of sulfur forms of coal and the pyrolysis behavior of sulfur compounds; Sekitanchu no io kagobutsu no keitaibetsu gan`yuryo no teiryo to sono netsubunkai kyodo

    Energy Technology Data Exchange (ETDEWEB)

    Mae, K.; Miura, K.; Shimada, M. [Kyoto University, Kyoto (Japan). Faculty of Engineering

    1996-10-28

    As part of the studies on coal utilization basics, considerations were given on quantification of sulfur forms of coal and the pyrolysis behavior of sulfur compounds. With the temperature raising oxidation method, a thermo-balance was connected directly to a mass analyzer, and the coal temperature was raised at a rate of 5{degree}C per minute and gasified. Peak division was performed on SO2 and COS production to derive sulfur forms of coal. Using the slow-speed pyrolysis method, production rates of H2S, COS, SO2 and mercaptans were measured at a temperature raising rate of 20{degree}C per minute. Sulfur content in char was also measured. With the quick pyrolysis method, a Curie point pyrolyzer was connected directly to a gas chromatograph, by which secondary reaction is suppressed, and initial pyrolytic behavior can be tracked. All kinds of coals produce a considerable amount of SO2 in the slow-speed pyrolysis, but very little in the quick pyrolysis. Instead, H2S and mercaptans are produced. Sulfur compound producing mechanisms vary depending on the temperature raising rates. By using a parallel primary reaction model, analysis was made on reactions of H2S production based on different activation energies, such as those generated from pyrite decomposition and organic sulfur decomposition. The analytic result agreed also with that from the temperature raising oxidation method. 4 refs., 6 figs., 1 tab.

  4. Migration and transformation of sulfur in the municipal sewage sludge during disposal in cement kiln.

    Science.gov (United States)

    Huang, Yuyan; Li, Haoxin; Jiang, Zhengwu; Yang, Xiaojie; Chen, Qing

    2018-05-07

    The aim of this work was to investigate the migration and transformation of sulfur in the municipal sewage sludge during disposal in cement kiln, and better understand the emission of the sulfur related pollutants in this process. In consideration of the temperature conditions in the practical operation, municipal sewage sludge was pre-dried at 105 °C, and then dried at 210, 260 and 310 °C, co-combusted with cement raw mill at 800, 900 and 1000 °C, and 1350, 1400 and 1450 °C respectively in the laboratory. X-ray photoelectron spectroscopy (XPS) was used to determine the S2p spectral lines of the municipal sewage sludge treated in the different process. Besides, The Thermal Analysis-Thermogravimetry (DTA-TG), Back Scattered Electron (BSE) and Energy Dispersive Spectrometer (EDS) were also employed to explore the mechanism of sulfur subsistence at 1450 °C. The results indicate that sulfide, thiophene, sulfone and sulfate are mainly sulfur compound in the municipal sewage sludge dried at 105 °C. Sulfoxide, a new sulfur compound, appears after it is further dried at 210 °C. The relative contents of sulfide and thiophene are continuously declined as the drying temperature increases due to their evaporation, decomposition and transformation in this process. The transformation of sulfide and thiophene makes the relative contents of sulfoxide and sulfate accordingly increased. However, the relative content of sulfone experiences an elevating-lowering process while the dry temperature elevated from 210 to 310 °C. This case is related to its evaporation and decomposition, as well as its production for the transformation of sulfide and thiophene. In the co-combustion process, sulfide, thiophene and sulfone are entirely vanished for their evaporation, decomposition and transformation. Sulfone is still contained at 800 °C, but when the temperature unceasingly rises, it is completely decomposed or evaporated and sulfate is the only sulfur compound. The

  5. Genomic and Evolutionary Perspectives on Sulfur Metabolism in Green Sulfur Bacteria

    DEFF Research Database (Denmark)

    Frigaard, Niels-Ulrik; Bryant, Donald A.

    2008-01-01

    Green sulfur bacteria (GSB) are anaerobic photoautotrophs that oxidize sulfide, elemental sulfur, thiosulfate, ferrous iron, and hydrogen for growth. We present here an analysis of the distribution and evolution of enzymes involved in oxidation of sulfur compounds in GSB based on genome sequence......, in combination with phylogenetic analyses, suggests that the Dsr system in GSB could be a recent acquisition, which was obtained by lateral gene transfer in part from sulfideoxidizing bacteria and in part from sulfate-reducing bacteria. All thiosulfate-utilizing GSB strains have an identical sox gene cluster...

  6. Sulfur utilization by rice and Crotalaria juncea from sulfate - 34S applied to the soil

    Directory of Open Access Journals (Sweden)

    Trivelin Paulo Cesar Ocheuze

    2002-01-01

    Full Text Available In tropical soils with intensive agriculture an increasing sulfur deficiency has been verified in several crops. The low available S in these soils is caused by the continuous use of concentrated NPK fertilizers. The objective of this work was to evaluate the utilization by rice (Oriza sativa L. and crotalaria juncea (Crotalaria juncea L. of sulfur applied to the soil, under greenhouse conditions. Pots with 3 kg of an Argisol (Paleudalf were used to test the isotopic technique with the stable isotope 34S, adding a solution of sodium sulfate labeled with 34S (14.30 ± 0.05 atom % of 34S to the soil (70 mg SO4-S per kg-1 of soil 18 days after sowing both species. The shoots of the crotalaria and rice were harvested, respectively on the 72nd and 122nd days after S fertilization. The concentration and the amount of sulfur in the crotalaria were higher than in rice, due to the higher legume requirement for this nutrient. The sulfur requirement and the short time interval between fertilization and harvest of the crotalaria resulted in a small amount of native SO4-S mineralized in the soil and a small quantity of 34SO4 immobilized by soil microorganisms. Thus, the percentage of sulfur in the crotalaria derived from the fertilizer (Sdff was higher than in the rice (%Sdff crotalaria = 91.3 ± 3.5%; %Sdff rice = 66.3 ± 0.8%. The expressive values of %Sdff indicate a low rate of mineralization of SO4-S probably as a consequence of the low available sulfur content in the soil.

  7. Sulfur-induced structural motifs on copper and gold surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Walen, Holly [Iowa State Univ., Ames, IA (United States)

    2016-01-01

    The interaction of sulfur with copper and gold surfaces plays a fundamental role in important phenomena that include coarsening of surface nanostructures, and self-assembly of alkanethiols. Here, we identify and analyze unique sulfur-induced structural motifs observed on the low-index surfaces of these two metals. We seek out these structures in an effort to better understand the fundamental interactions between these metals and sulfur that lends to the stability and favorability of metal-sulfur complexes vs. chemisorbed atomic sulfur. The experimental observations presented here—made under identical conditions—together with extensive DFT analyses, allow comparisons and insights into factors that favor the existence of metal-sulfur complexes, vs. chemisorbed atomic sulfur, on metal terraces. We believe this data will be instrumental in better understanding the complex phenomena occurring between the surfaces of coinage metals and sulfur.

  8. Determination of sulfur dioxide by a radiorelease method

    Energy Technology Data Exchange (ETDEWEB)

    Sriman Narayanan, S.; Rao, V.R.S. (Indian Inst. of Tech., Madras. Dept. of Chemistry)

    1983-04-13

    A radiorelease technique for the determination of sulfur dioxide using radiochlor /sup 36/Cl-amine-T is described. Methods for the elimination of interference from coexisting gases are also reported. 1-40 ppm sulfur dioxide can be determined.

  9. Determination of sulfur dioxide by a radiorelease method

    International Nuclear Information System (INIS)

    Sriman Narayanan, S.; Rao, V.R.S.

    1983-01-01

    A radiorelease technique for the determination of sulfur dioxide using radiochlor 36 Cl-amine-T is described. Methods for the elimination of interference from coexisting gases are also reported. 1-40 ppm sulfur dioxide can be determined. (author)

  10. Total Sulfur Deposition (wet+dry) from the Atmosphere

    Data.gov (United States)

    U.S. Environmental Protection Agency — Sulfur Dioxide (SO2) is emitted primarily as a by-product of coal combustion from power plants. Sulfur Dioxide reacts in the atmosphere to form other chemical such...

  11. Sulfur Release during Alternative fuels Combustion in Cement Rotary Kilns

    DEFF Research Database (Denmark)

    Cortada Mut, Maria del Mar

    fuel with the bed material, heating up of a particle, 5 iv devolatilization, char combustion, the reactions between CaSO 4 and the different reducing agents, and the oxidation of the volatiles gases in the free board. The main reducing agents are CO, CH 4 and H 2 , which are introduced under the bed...... are of high importance for SO 2 release because it is shown that introducing the same total amount of gas, the highest reducing agent concentration fo r a short period released a higher total SO 2 amount compared to the lowest concentration during a long period. A mathematical reaction based model...... but the effect of sulfur content in the bed cannot be predicted. Further development regarding particle motion according to the rotational speed may be needed. Furthermore, a model for predicting the tendency of build-ups for a kiln system is developed based on the prediction of SO 3 and Cl concentrations...

  12. Injury to fruit and forest trees from sulfur dioxide emissions

    Energy Technology Data Exchange (ETDEWEB)

    Berge, H

    1959-01-01

    Observations and the results of examinations on the control of emissions in the northeastern part of the industrial area of Nordrhein-Westfalen led to the conclusions that under certain conditions plant analysis is an important tool in diagnosing smoke injuries. Schedules for the sensitivity of plants are only of local and temporary value. The applicability of comparative plant analyses to smoke injuries is demonstrated by examples. A number of examples show that parasitic attack or illness magnify the effects of SO/sub 2/. For several tree species the seasonal total content of sulfur (given as SO/sub 2/) in the foliage is shown by curves, which are similar to those obtained in Leicester. 17 references, 6 figures, 2 tables.

  13. Do volcanic eruptions affect climate? Sulfur gases may cause cooling

    Science.gov (United States)

    Self, Stephen; Rampino, Michael R.

    1988-01-01

    The relationship between volcanic eruptions on earth and the observed climatic changes is investigated. The results of the comparison and analyses of volcanologic and climatologic data sets for the years between 1880 and 1980 indicate that changes in temperature caused by even of the largest eruptions recorded during this time were about the same as normal variations in temperature. However, when temperature records for several months or years preceding and following a given eruption were analyzed, a statistically significant temperature decrease of 0.2-0.5 C was found for the periods of one to two years immediately following some of the 19th and 20th century explosive events that prodiced large aerosol clouds (e.g., Krakatau and Agung eruptions). It is suggested that the content of sulfur in the erupted magma determines the size of aerosol cloud producing the cooling effect.

  14. Relation of sulfur with hydrocarbons in Brazilian heavy and extra-heavy crude oil; Relacao do enxofre com os hidrocarbonetos em petroleos pesados e extra pesados brasileiros

    Energy Technology Data Exchange (ETDEWEB)

    Iorio, Sonia Maria Badaro Mangueira; Guimaraes, Regina Celia Lourenco; Silva, Maria do Socorro A. Justo da [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Costa, Alexander Vinicius Moraes da [Fundacao Gorceix, Ouro Preto, MG (Brazil)

    2008-07-01

    As the occurrence of heavy and extra-heavy oils increases sensitively, their participation in the refineries feeding also becomes greater. Heavy oils usually have lower price than a light one, because they produce lower quality derivatives and it's more difficult to meet the specifications. Crude oils are a complex mixture, mostly compounded by carbon and hydrogen and also by impurities like sulfur, nitrogen, oxygen and metals. Sulfur is the third most abundant component of crude oils, following carbon and hydrogen. In general there is a strong positive correlation between the concentrations of polar compounds (aromatics, resins and asphaltenes), and the sulfur content. This work presents graphically sulfur content and polar compounds concentrations for Brazilian and foreign heavy and extra-heavy oils (< 20 deg API). The results of the data analysis indicate that Brazilian crude oils behave differently from foreign heavy and extra-heavy oils. (author)

  15. Oxidation of inorganic sulfur compounds in acidophilic prokaryotes

    Energy Technology Data Exchange (ETDEWEB)

    Rohwerder, T.; Sand, W. [Universitaet Duisburg-Essen, Biofilm Centre, Aquatic Biotechnology, Duisburg (Germany)

    2007-07-15

    The oxidation of reduced inorganic sulfur compounds to sulfuric acid is of great importance for biohydrometallurgical technologies as well as the formation of acidic (below pH 3) and often heavy metal-contaminated environments. The use of elemental sulfur as an electron donor is the predominant energy-yielding process in acidic natural sulfur-rich biotopes but also at mining sites containing sulfidic ores. Contrary to its significant role in the global sulfur cycle and its biotechnological importance, the microbial fundamentals of acidophilic sulfur oxidation are only incompletely understood. Besides giving an overview of sulfur-oxidizing acidophiles, this review describes the so far known enzymatic reactions related to elemental sulfur oxidation in acidophilic bacteria and archaea. Although generally similar reactions are employed in both prokaryotic groups, the stoichiometry of the key enzymes is different. Bacteria oxidize elemental sulfur by a sulfur dioxygenase to sulfite whereas in archaea, a sulfur oxygenase reductase is used forming equal amounts of sulfide and sulfite. In both cases, the activation mechanism of elemental sulfur is not known but highly reactive linear sulfur forms are assumed to be the actual substrate. Inhibition as well as promotion of these biochemical steps is highly relevant in bioleaching operations. An efficient oxidation can prevent the formation of passivating sulfur layers. In other cases, a specific inhibition of sulfur biooxidation may be beneficial for reducing cooling and neutralization costs. In conclusion, the demand for a better knowledge of the biochemistry of sulfur-oxidizing acidophiles is underlined. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  16. Local Content

    CSIR Research Space (South Africa)

    Gibberd, Jeremy

    2016-10-01

    Full Text Available Local content refers to materials and products made in a country as opposed those that are imported. There is an increasing interest in the concept of local content as a means of supporting local economies and providing jobs (Belderbos & Sleuwaegen...

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

    Science.gov (United States)

    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.

  18. A Study on the Properties and Chloride Resistance of Modified Sulfur Concrete for Nuclear Power Plant and Marine Structures

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Soon Myun; Chang, Hyun Young; Park, Heung Bae [KEPCO EnC, Seongnam (Korea, Republic of)

    2015-05-15

    The mechanical, physical and chemical properties of concrete with modified sulfur have been compared and assessed against ordinary concrete. As its excellent chloride resistance and extended service life have been verified, the technology to apply modified sulfur to the construction of nuclear power plant and marine structures has been developed and secured. Recently, modified sulfur concrete has been applied for road pavement and repair works in more than 20 sites including highway and airport in Korea. Also, in the U.S., Federal Highway Administration and Virginia Department of Transportation are implementing tests to apply modified sulfur to bridge road pavement, and the modified sulfur concrete has been recognized for its good performance. Based on these cases, this study carried out tests on physical, mechanical and chemical properties of concrete after adding modified sulfur by building concrete specimens based on the concrete mix design employed to construct the Shin-Kori Units 3 and 4 containment building. Multiple tests were performed particularly for chemical resistance, a factor directly related to concrete service life. As a result, it has been verified that concrete with 5% modified sulfur content relative to cement weight has equal mechanical properties (compressive strength, tensile strength, etc.) and much better workability (slump change) and chemical resistance (resistance to chloride ion penetration, concrete carbonation) compared with ordinary concrete. Based on this, it has been concluded that an addition of modified sulfur can double the service life of concrete. In general, studies demonstrate that a significant amount of slag should be mixed into concrete to raise chemical resistance (but with decreasing mechanical properties). Considering this, this study is unparalleled.

  19. A Study on the Properties and Chloride Resistance of Modified Sulfur Concrete for Nuclear Power Plant and Marine Structures

    International Nuclear Information System (INIS)

    Wang, Soon Myun; Chang, Hyun Young; Park, Heung Bae

    2015-01-01

    The mechanical, physical and chemical properties of concrete with modified sulfur have been compared and assessed against ordinary concrete. As its excellent chloride resistance and extended service life have been verified, the technology to apply modified sulfur to the construction of nuclear power plant and marine structures has been developed and secured. Recently, modified sulfur concrete has been applied for road pavement and repair works in more than 20 sites including highway and airport in Korea. Also, in the U.S., Federal Highway Administration and Virginia Department of Transportation are implementing tests to apply modified sulfur to bridge road pavement, and the modified sulfur concrete has been recognized for its good performance. Based on these cases, this study carried out tests on physical, mechanical and chemical properties of concrete after adding modified sulfur by building concrete specimens based on the concrete mix design employed to construct the Shin-Kori Units 3 and 4 containment building. Multiple tests were performed particularly for chemical resistance, a factor directly related to concrete service life. As a result, it has been verified that concrete with 5% modified sulfur content relative to cement weight has equal mechanical properties (compressive strength, tensile strength, etc.) and much better workability (slump change) and chemical resistance (resistance to chloride ion penetration, concrete carbonation) compared with ordinary concrete. Based on this, it has been concluded that an addition of modified sulfur can double the service life of concrete. In general, studies demonstrate that a significant amount of slag should be mixed into concrete to raise chemical resistance (but with decreasing mechanical properties). Considering this, this study is unparalleled

  20. Thermochemical Sulfate Reduction Simulation Experiments on the Formation and Distribution of Organic Sulfur Compounds in the Tuha Crude Oil

    Energy Technology Data Exchange (ETDEWEB)

    Yue, Changtao; Li, Shuyuan [China Univ. of Petroleum, Beijing (China); Song, He [Research Institute of Petroleum Engineering of CNPC, Tianjin (China)

    2014-07-15

    Thermochemical sulfate reduction (TSR) was conducted in autoclave on the system of crude oil and MgSO{sub 4} at different temperatures. Gas chromatography pulsed flame photometric detector (GC-PFPD) was used to detected the composition of organic sulfur compounds in oil phase products. The results of the analysis indicate that with increased temperature, the contents of organic sulfur compounds with high molecular weight and thermal stability, such as benzothiophenes and dibenzothiophenes, gradually became dominated. In order to gain greater insight into the formation and distribution of organic sulphur compounds from TSR, positive ion electrospray Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) was used in detecting the detailed elemental composition and distribution of them. The mass spectra showed that the mass range of sulfur compounds was 200-550 Da. Four sulfur class species, S{sub 1}, N{sub 1}S{sub 1}, O{sub 1}S{sub 1} and O{sub 2}S{sub 1}, were assigned in the positive-ion spectrum. Among the identified sulfur compounds, the S{sub 1} class species was dominant. The most abundant S{sub 1} class species increase associated with the DBE value and carbon number increasing which also indicates the evolution of organic sulfur compounds in TSR is from the labile series to the stable one. In pure blank pyrolysis experiments with crude oil cracking without TSR, different composition and distribution of organic sulfur compounds in oil phase products were seen from mass spectra in order to evaluate their pyrolysis behaviors without MgSO{sub 4}. FT-IR and XRD were used in analyzing the products of solid phases. Two distinct crystallographic phases MgO and MgSO{sub 4} are found to coexist in the products which demonstrated the transformation of inorganic sulfur compounds into organosulfur compounds exist in TSR.

  1. Influence of sulfur dioxide on the mineral composition of needles from spruces

    Energy Technology Data Exchange (ETDEWEB)

    Materna, J

    1961-01-01

    Until recently all the authors knew about changes in the mineral composition of plants exposed to air pollution was that the sulfur content increases considerably. The question arises whether other mineral substances, too, accumulate in the assimilating organs of smoke injured plants, particularly cations such as calcium, potassium and magnesium. Results of analyses of spruce needles from an air polluted forest in the Erzebirge in Czechoslovakia yielded no relationship between the accumulation of sulfates and the mentioned cations.

  2. Mercury chemisorption by sulfur adsorbed in porous materials

    NARCIS (Netherlands)

    Steijns, M.; Peppelenbos, A.; Mars, P.

    1976-01-01

    The sorption of mercury vapor by adsorbed sulfur in the zeolites CaA (= 5A) and NaX (=13X) and two types of active carbon has been measured at a temperature of 50°C. With increasing degree of micropore filling by sulfur the fraction of sulfur accessible to mercury atoms decreased for CaA and NaX.

  3. Relationship between corrosion and the biological sulfur cycle: A review

    Energy Technology Data Exchange (ETDEWEB)

    Little, B.J.; Ray, R.I.; Pope, R.K.

    2000-04-01

    Sulfur and sulfur compounds can produce pitting, crevice corrosion, dealloying, stress corrosion cracking, and stress-oriented hydrogen-induced cracking of susceptible metals and alloys. Even though the metabolic by-products of the biological sulfur cycle are extremely corrosive, there are no correlations between numbers and types of sulfur-related organisms and the probability or rate of corrosion, Determination of specific mechanisms for corrosion caused by microbiologically mediated oxidation and reduction of sulfur and sulfur compounds is complicated by the variety of potential metabolic-energy sources and by-products; the coexistence of reduced and oxidized sulfur species; competing reactions with inorganic and organic compounds; and the versatility and adaptability of microorganisms in biofilms. The microbial ecology of sulfur-rich environments is poorly understood because of the association of aerobes and anaerobes and the mutualism or succession of heterotrophs to autotrophs. The physical scale over which the sulfur cycle influences corrosion varies with the environment. The complete sulfur cycle of oxidation and reduction reactions can take place in macroenvironments, including sewers and polluted harbors, or within the microenvironment of biofilms. In this review, reactions of sulfur and sulfur compounds resulting in corrosion were discussed in the context of environmental processes important to corrosion.

  4. 40 CFR 180.444 - Sulfur dioxide; tolerances for residues.

    Science.gov (United States)

    2010-07-01

    ... § 180.444 Sulfur dioxide; tolerances for residues. A tolerance is established as follows for sulfite residues of the fungicide sulfur dioxide (determined as (SO2)) in or on the following raw agricultural... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Sulfur dioxide; tolerances for...

  5. Physiology of alkaliphilic sulfur-oxidizing bacteria from soda lakes

    NARCIS (Netherlands)

    Banciu, H.L.

    2004-01-01

    The inorganic sulfur oxidation by obligate haloalkaliphilic chemolithoautotrophs was only recently discovered and investigated. These autotrophic sulfur oxidizing bacteria (SOB), capable of oxidation of inorganic sulfur compounds at moderate to high salt concentration and at high pH, can be divided

  6. Biologically produced sulfur particles and polysulfide ions

    NARCIS (Netherlands)

    Kleinjan, W.E.

    2005-01-01

    This thesis deals with the effects of particles of biologically produced sulfur (or 'biosulfur') on a biotechnological process for the removal of hydrogen sulfide from gas streams. Particular emphasis is given to the role of polysulfide ions in such a process. These

  7. Hot-Gas Desulfurization with Sulfur Recovery

    International Nuclear Information System (INIS)

    Portzer, Jeffrey W.; Damle, Ashok S.; Gangwal, Santosh K.

    1997-01-01

    The objective of this study is to develop a second generation HGD process that regenerates the sulfided sorbent directly to elemental sulfur using SO 2 , with minimal consumption of coal gas. The goal is to have better overall economics than DSRP when integrated with the overall IGCC system

  8. Intestinal metabolism of sulfur amino acids

    Science.gov (United States)

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

  9. Integrated Science Assessment (ISA) for Sulfur Oxides ...

    Science.gov (United States)

    This draft document provides EPA’s evaluation and synthesis of the most policy-relevant science related to the health effects of sulfur oxides. When final, it will provide a critical part of the scientific foundation for EPA’s decision regarding the adequacy of the current primary (health-based) National Ambient Air Quality Standard (NAAQS) for sulfur dioxide. The references considered for inclusion in or cited in the external review draft ISA are available at https://hero.epa.gov/hero/sulfur-oxides. The intent of the ISA, according to the CAA, is to “accurately reflect the latest scientific knowledge expected from the presence of [a] pollutant in ambient air” (U.S. Code, 1970a, 1970b). It includes an assessment of scientific research from atmospheric sciences, exposure sciences, dosimetry, mode of action, animal and human toxicology, and epidemiology. Key information and judgments formerly found in the Air Quality Criteria Documents (AQCDs) for sulfur oxides (SOx) are included; Annexes provide additional details supporting the ISA. Together, the ISA and Annexes serve to update and revise the last SOx ISA which was published in 2008.

  10. Development of enhanced sulfur rejection processes

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-03-01

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

  11. Methane oxidation in presence of sulfur dioxide

    International Nuclear Information System (INIS)

    Mantashyan, A.A.; Avetisyan, A.M.; Makaryan, E.M.; Wang, H.

    2006-01-01

    The emission of sulfurous gases including SO 2 from stationary power generation remains to be a serious environmental and ecological problem. Sulfurous gases are almost entirely produced from the combustion of sulfur-containing fuels. While fuel desulfurization and flue gas scrubbing is a viable solution, in the developing countries it remains to be an economical challenge to implement these SO x reduction technologies. The oxidation of methane in presence of sulfurous gas (SO 2 ) addition was studied experimentally. Te experiments were conducted in a static reactor at temperature of 728-786 K, and for mixture of C 4 /O 2 ≡ 1/2 at a pressure of 117 Torr with varying amount of SO 2 addition. It was observed that SO 2 addition accelerated the oxidation process, reduced the induction period and increased the extent of methane consumption. At the relatively short resident time (less than 50 sec) SO 3 was detected, but at longer residence time SO 3 was reduced spontaneously to SO 2

  12. Behaviour of organic sulfur compounds in HPLC

    International Nuclear Information System (INIS)

    Freyholdt, T.

    1982-01-01

    The retention behaviour of organic sulfur compounds in the reverse-bonded-phase chromatography is characterized by determining the retention indices according to Kovats. The results of these studies show that the solubility of organic compounds in the eluting agent and the molar sorption surfaces of the solutes are the main factors determining the retention behaviour. Knowledge of the retention indices of above-mentioned compounds allows a quick interpretation of chromatograms obtained through a product analysis of γ-irradiated aqueous solutions of organic sulfur compounds. Dithia compounds of the type CH 3 -S-(CH 2 )sub(n)-S-Ch 3 (1 1. 2,4-Dithiapentane (n = 1) however will yield primarily monothio-S-methyl formate as a stable end product. The formation of oxygenic reaction products proceeds via sulfur-centred radical kations. Spin trapping experiments with nitroxyl radicals show that it is possible to trap radiation-chemically produced radicals of sulfurous substrates, but the thus obtained adducts with half-life periods of 4-5 min. cannot be identified by means of NMR, IR or mass spectroscopy. (orig.) [de

  13. Sulfur and selenium isotope separation by distillation

    International Nuclear Information System (INIS)

    Mills, T. R.; McInteer, B. B.; Montoya, J. G.

    1988-01-01

    Sulfur and selenium isotopes are used for labeled compounds and as precursors for radioisotope production; however, both limited availability and high costs are problems. A new method is needed for large-scale separation of these isotopes. Experimental distillation columns were used to measure isotopic separations for sulfur and selenium compounds. The maximum total isotope separation of 32 S vs. 34 S were 1.127 for H 2 S, 1.048 for COS, 0.838 for SF 4 , and 1.058 for CH 3 SH. Relative volatilities of 32 S vs. 34 S are 1.0006 for COS and 0.9976 for SF 4 . There is a reverse isotope effect for carbon in COS. No isotopic separation was observed for dimethyl selenide. The lower mass selenium isotopes in H 2 Se are more volatile. Distillation is a promising method for separating sulfur isotopes on a production scale. Existing distillation technology produced separated isotopes with an effect similar to that found for sulfur in SF 4 . 8 refs., 2 tabs

  14. Sulfur and selenium isotope separation by distillation

    International Nuclear Information System (INIS)

    Mills, T.R.; McInteer, B.B.; Montoya, J.G.

    1989-01-01

    Sulfur and selenium isotopes are used for labeled compounds and as precursors for radioisotope production; however, both limited availability and high costs are problems. A new method is needed for large-scale separation of theses isotopes. Experimental distillation columns were used to measure isotopic separations for sulfur and selenium compounds. The maximum total isotope separations of 32 S vs. 34 S were 1.127 for H 2 S, 1.048 for COS, 0.838 for SF 4 , and 1.058 for CH 3 SH. Relative volatilities of 32 S and 34 S are 1.0006 for COS and 0.9976 for SF 4 . There is a reverse isotope effect for carbon in COS. No isotopic separation was observed for dimethyl selenide. The lower mass selenium isotopes in H 2 Se are more volatile. Distillation is a promising method for separating sulfur isotopes on a production scale. Existing distillation technology produces separated isotopes with an effect similar to that found for sulfur in SF 4 . (author). 8 refs.; 2 tabs

  15. Helium and Sulfur Hexafluoride in Musical Instruments

    Science.gov (United States)

    Forinash, Kyle; Dixon, Cory L.

    2014-01-01

    The effects of inhaled helium on the human voice were investigated in a recent article in "The Physics Teacher." As mentioned in that article, demonstrations of the effect are a popular classroom activity. If the number of YouTube videos is any indication, the effects of sulfur hexafluoride on the human voice are equally popular.…

  16. Isotope effects of sulfur in chemical reactions

    International Nuclear Information System (INIS)

    Mikolajczuk, A.

    1999-01-01

    Sulfur is an important component of organic matter because it forms compounds with many elements. Due to high chemical activity of sulfur, it takes part in biological and geological processes in which isotope effects are occurring. It has been shown during last years research of isotope effects that we have take into account not only mass difference but also many other physical properties of nuclides e.g. even or odd number of neutrons in nuclei, shape and distribution of charge, turn of nuclear spin etc. The factor remains that new theoretical ideas have been formed on the base of data, being obtained in fractionation processes of heavy element isotope, particularly uranium. Now it is being well known that effects unconnected with vibration energy have also caused an effect on fractionation of considerably lighter elements like iron and magnesium. The important question is, if these effects would come to light during the separation of sulfur isotopes. Sulfur have three even isotopes M = (32, 34, 36) and one odd M 33). This problem is still open. (author)

  17. Effects of elemental sulfur and sulfur-containing waste on nutrient ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-09-15

    Sep 15, 2009 ... grown twice on the same soils to determine initial and residual effects of applied S. Results showed that applications of ... Key words: Calcareous soil, plant growth, plant nutrition, sulfur application. ...... Colombia. Can. J. Soil ...

  18. Damage caused to vegetation by sulfurous and sulfuric acids in the atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Tatlock, R R; Thomson, R T

    1914-05-01

    This report, written in 1914, documents injuries to trees and shrubs in the United Kingdom which are attributed to sulfur compounds in air pollutions. Sampling, analytical and experimental procedures are discussed.

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

    Science.gov (United States)

    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.

  20. Attribution of atmospheric sulfur dioxide over the English Channel to dimethyl sulfide and changing ship emissions

    Science.gov (United States)

    Yang, Mingxi; Bell, Thomas G.; Hopkins, Frances E.; Smyth, Timothy J.

    2016-04-01

    Atmospheric sulfur dioxide (SO2) was measured continuously from the Penlee Point Atmospheric Observatory (PPAO) near Plymouth, United Kingdom, between May 2014 and November 2015. This coastal site is exposed to marine air across a wide wind sector. The predominant southwesterly winds carry relatively clean background Atlantic air. In contrast, air from the southeast is heavily influenced by exhaust plumes from ships in the English Channel as well as near Plymouth Sound. A new International Maritime Organization (IMO) regulation came into force in January 2015 to reduce the maximum allowed sulfur content in ships' fuel 10-fold in sulfur emission control areas such as the English Channel. Our observations suggest a 3-fold reduction in ship-emitted SO2 from 2014 to 2015. Apparent fuel sulfur content calculated from coincidental SO2 and carbon dioxide (CO2) peaks from local ship plumes show a high level of compliance to the IMO regulation (> 95 %) in both years (˜ 70 % of ships in 2014 were already emitting at levels below the 2015 cap). Dimethyl sulfide (DMS) is an important source of atmospheric SO2 even in this semi-polluted region. The relative contribution of DMS oxidation to the SO2 burden over the English Channel increased from about one-third in 2014 to about one-half in 2015 due to the reduction in ship sulfur emissions. Our diel analysis suggests that SO2 is removed from the marine atmospheric boundary layer in about half a day, with dry deposition to the ocean accounting for a quarter of the total loss.

  1. 40 CFR 80.205 - How is the annual refinery or importer average and corporate pool average sulfur level determined?

    Science.gov (United States)

    2010-07-01

    ... volume of gasoline produced or imported in batch i. Si=The sulfur content of batch i determined under § 80.330. n=The number of batches of gasoline produced or imported during the averaging period. i=Individual batch of gasoline produced or imported during the averaging period. (b) All annual refinery or...

  2. Development of alternative sulfur dioxide control strategies for a metropolitan area and its environs, utilizing a modified climatological dispersion model

    Science.gov (United States)

    K. J. Skipka; D. B. Smith

    1977-01-01

    Alternative control strategies were developed for achieving compliance with ambient air quality standards in Portland, Maine, and its environs, using a modified climatological dispersion model (CDM) and manipulating the sulfur content of the fuel oil consumed in four concentric zones. Strategies were evaluated for their impact on ambient air quality, economics, and...

  3. Organic sulfur metabolisms in hydrothermal environments.

    Science.gov (United States)

    Rogers, Karyn L; Schulte, Mitchell D

    2012-07-01

    Sulfur is central to the metabolisms of many organisms that inhabit extreme environments. While biotic and abiotic cycling of organic sulfur compounds has been well documented in low-temperature anaerobic environments, cycling of organic sulfur in hydrothermal environments has received less attention. Recently published thermodynamic data have been used to estimate aqueous alkyl thiol and sulfide activities in deep-sea hydrothermal systems. Here we use geochemical mixing models to predict fluid compositions that result from mixing end-member hydrothermal fluid from the East Pacific Rise with bottom seawater. These fluid compositions are combined with estimates of methanethiol and dimethylsulfide activities to evaluate energy yields for potential organic sulfur-based metabolisms under hydrothermal conditions. Aerobic respiration has the highest energy yields (over -240 kJ/mol e⁻) at lower temperature; however, oxygen is unlikely to persist at high temperatures, restricting aerobic respiration to mesophilic communities. Nitrite reduction to N₂ has the highest energy yields at higher temperatures (greater than ∼40 °C). Nitrate and nitrite reduction to ammonium also yield significant energy (up to -70 kJ/mol e⁻). Much lower, but still feasible energy yields are calculated for sulfate reduction, disproportionation, and reduction with H₂. Organic compound family and the activity of methanethiol and dimethylsulfide were less important than metabolic strategy in determining overall energy yields. All metabolic strategies considered were exergonic within some portion of the mixing regime suggesting that organic sulfur-based metabolisms may be prevalent within deep-sea hydrothermal vent microbial communities. © 2012 Blackwell Publishing Ltd.

  4. Effects of sulfur oxides on eicosanoids

    International Nuclear Information System (INIS)

    Chen, L.C.; Miller, P.D.; Amdur, M.O.

    1989-01-01

    Ultrafine metal oxides and SO2 react during coal combustion or smelting operations to form primary emissions coated with an acidic SOx layer. Ongoing work in this laboratory has examined the effects of sulfur oxides on pulmonary functions of guinea pigs. We have previously reported that 20 micrograms/m3 acidic sulfur oxide as a surface layer on ultrafine ZnO particles decreases lung volumes, decreases carbon monoxide diffusing capacity, and causes lung inflammation in guinea pigs after 4 daily 3-h exposures. It also produces bronchial hypersensitivity following a single 1-h exposure. The importance of this surface layer is demonstrated by our observation that 200 micrograms/m3 of sulfuric acid droplets of equivalent size are needed to produce the same degree of hypersensitivity. This study characterized the concentration-dependent effects of in vivo exposures to sulfur oxides on arachidonic acid metabolism in the guinea pig lung, and investigated the time course and the relation between eicosanoid composition and pulmonary functions. We focused specifically on four cyclooxygenase metabolites of arachidonic acid, that is, prostaglandins (PG) E1, F2 alpha, 6-keto prostaglandin F1 alpha, and thromboxane (Tx) B2, and two groups of sulfidopeptide leukotrienes (C4, D4, E4, and F4). Guinea pigs were exposed to ultrafine ZnO aerosol (count median diameter = 0.05 microns, sigma g = 1.80) with a layer of acidic sulfur oxide on the surface of the particles. Lung lavage was collected after exposures, and the levels of arachidonic acid metabolites were determined using radioimmunoassay (RIA). Concentration-dependent promotion of PGF2 alpha and concentration-dependent suppression of LtB4 were observed. The increased PGF2 alpha was associated with depressed vital capacity and diffusing capacity of the lungs measured in guinea pigs exposed to the same atmosphere described in a previous study

  5. Io's theothermal (sulfur) - Lithosphere cycle inferred from sulfur solubility modeling of Pele's magma supply

    Science.gov (United States)

    Battaglia, Steven M.; Stewart, Michael A.; Kieffer, Susan W.

    2014-06-01

    Surface deposits of volatile compounds such as water (Earth) or sulfur (Io) on volcanically active bodies suggest that a magmatic distillation process works to concentrate volatiles in surface reservoirs. On Earth, this is the combined hydrologic and tectonic cycle. On Io, sulfurous compounds are transferred from the interior to the surface reservoirs through a combination of a mantle-sourced magmatic system, vertical cycling of the lithosphere, and a sulfur-dominated crustal thermal system that we here call the "theothermal" system. We present a geochemical analysis of this process using previously inferred temperature and oxygen fugacity constraints of Pele's basaltic magma to determine the behavior of sulfur in the ionian magmas. Sulfate to sulfide ratios of Pele's magma are -4.084 ± 0.6 and -6.442 ± 0.7 log10 units, comparable to or lower than those of mid-ocean ridge basalts. This reflects the similarity of Io's oxidation state with Earth's depleted mantle as previously suggested by Zolotov and Fegley (Zolotov, M.Y., Fegley, B. [2000]. Geophys. Res. Lett. 27, 2789-2792). Our calculated limits of sulfur solubility in melts from Pele's patera (˜1100-1140 ppm) are also comparable to terrestrial mid-ocean ridge basalts, reflecting a compositional similarity of mantle sources. We propose that the excess sulfur obvious on Io's surface comes from two sources: (1) an insoluble sulfide liquid phase in the magma and (2) theothermal near-surface recycling.

  6. Preparation and electrochemical performance of sulfur-alumina cathode material for lithium-sulfur batteries

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Kang [Faculty of Material Science and Chemistry, China University of Geosciences, 388 Lumo Road, 430074 Wuhan (China); Wang, Shengping, E-mail: spwang@cug.edu.cn [Faculty of Material Science and Chemistry, China University of Geosciences, 388 Lumo Road, 430074 Wuhan (China); Zhang, Hanyu; Wu, Jinping [Faculty of Material Science and Chemistry, China University of Geosciences, 388 Lumo Road, 430074 Wuhan (China)

    2013-06-01

    Highlights: ► Micron-sized alumina was synthesized as adsorbent for lithium-sulfur batteries. ► Sulfur-alumina material was synthesized via crystallizing nucleation. ► The Al{sub 2}O{sub 3} can provide surface area for the deposition of Li{sub 2}S and Li{sub 2}S{sub 2}. ► The discharge capacity of the battery is improved during the first several cycles. - Abstract: Nano-sized sulfur particles exhibiting good adhesion with conducting acetylene black and alumina composite materials were synthesized by means of an evaporated solvent and a concentrated crystallization method for use as the cathodes of lithium-sulfur batteries. The composites were characterized and examined by X-ray diffraction, environmental scanning electron microscopy and electrochemical methods, such as cyclic voltammetry, electrical impedance spectroscopy and charge–discharge tests. Micron-sized flaky alumina was employed as an adsorbent for the cathode material. The initial discharge capacity of the cathode with the added alumina was 1171 mAh g{sup −1}, and the remaining capacity was 585 mAh g{sup −1} after 50 cycles at 0.25 mA cm{sup −2}. Compared with bare sulfur electrodes, the electrodes containing alumina showed an obviously superior cycle performance, confirming that alumina can contribute to reducing the dissolution of polysulfides into electrolytes during the sulfur charge–discharge process.

  7. Effects of Sulfurization Temperature on Properties of CZTS Films by Vacuum Evaporation and Sulfurization Method

    Directory of Open Access Journals (Sweden)

    Jie Zhang

    2013-01-01

    Full Text Available Copper zinc tin sulfur (CZTS thin films have been extensively studied in recent years for their advantages of low cost, high absorption coefficient (≥104 cm−1, appropriate band gap (~1.5 eV, and nontoxicity. CZTS thin films are promising materials of solar cells like copper indium gallium selenide (CIGS. In this work, CZTS thin films were prepared on glass substrates by vacuum evaporation and sulfurization method. Sn/Cu/ZnS (CZT precursors were deposited by thermal evaporation and then sulfurized in N2 + H2S atmosphere at temperatures of 360–560°C to produce polycrystalline CZTS thin films. It is found that there are some impurity phases in the thin films with the sulfurization temperature less than 500°C, and the crystallite size of CZTS is quite small. With the further increase of the sulfurization temperature, the obtained thin films exhibit preferred (112 orientation with larger crystallite size and higher density. When the sulfurization temperature is 500°C, the band gap energy, resistivity, carrier concentration, and mobility of the CZTS thin films are 1.49 eV, 9.37 Ω · cm, 1.714×1017 cm−3, and 3.89 cm2/(V · s, respectively. Therefore, the prepared CZTS thin films are suitable for absorbers of solar cells.

  8. Preparation and electrochemical performance of sulfur-alumina cathode material for lithium-sulfur batteries

    International Nuclear Information System (INIS)

    Dong, Kang; Wang, Shengping; Zhang, Hanyu; Wu, Jinping

    2013-01-01

    Highlights: ► Micron-sized alumina was synthesized as adsorbent for lithium-sulfur batteries. ► Sulfur-alumina material was synthesized via crystallizing nucleation. ► The Al 2 O 3 can provide surface area for the deposition of Li 2 S and Li 2 S 2 . ► The discharge capacity of the battery is improved during the first several cycles. - Abstract: Nano-sized sulfur particles exhibiting good adhesion with conducting acetylene black and alumina composite materials were synthesized by means of an evaporated solvent and a concentrated crystallization method for use as the cathodes of lithium-sulfur batteries. The composites were characterized and examined by X-ray diffraction, environmental scanning electron microscopy and electrochemical methods, such as cyclic voltammetry, electrical impedance spectroscopy and charge–discharge tests. Micron-sized flaky alumina was employed as an adsorbent for the cathode material. The initial discharge capacity of the cathode with the added alumina was 1171 mAh g −1 , and the remaining capacity was 585 mAh g −1 after 50 cycles at 0.25 mA cm −2 . Compared with bare sulfur electrodes, the electrodes containing alumina showed an obviously superior cycle performance, confirming that alumina can contribute to reducing the dissolution of polysulfides into electrolytes during the sulfur charge–discharge process

  9. NONEQUILIBRIUM SULFUR CAPTURE AND RETENTION IN AN AIR COOLED SLAGGING COAL COMBUSTOR

    International Nuclear Information System (INIS)

    Dr. Bert Zauderer

    1999-01-01

    Calcium oxide injected in a slagging combustor reacts with the sulfur from coal combustion to form sulfur-bearing particles. They are deposited on the liquid slag layer on the combustor wall. Due to the low solubility of sulfur in slag, slag must be rapidly drained from the combustor to limit sulfur gas re-evolution. Analysis indicated that slag mass flow rates in excess of 400 lb/hr should limit sulfur re-evolution. The objective of this 42-month project was to perform a series of tests to determine the factors that control the retention of the sulfur in the slag. 36 days of testing on the combustor were completed prior to the end of this reporting period, 12/31/98. This compares with 16 tests required in the original project plan. Combustor tests in early 1997 with high (37%) ash, Indian coal confirmed that high slag mass flow rates of about 500 lb/hr resulted in retention in the slag of up to 20% of the injected sulfur content mineral matter. To further increase the slag flow rate, rice husks, which contain 20% ash, and rice husk char, which contain 70% ash, were co-fired with coal in the combustor. A series of 13 combustor tests were performed in fourth quarter of 1997 and a further 6 tests were performed in January 1998 and in the summer of 1998. The test objective was to achieve slag flow rates between 500 and 1,000 lb/hr. Due to the very low bulk density of rice husk, compared to pulverized coal, almost the entire test effort focused on developing methods for feeding the rice husks into combustor. In the last test of December 1997, a peak mineral matter, injection rate of 592 lb/hr was briefly achieved by injection of coal, rice husk char, gypsum, and limestone into the combustor. However, no significant sulfur concentration was measured in the slag removed from the combustor. The peak injection rate reached with biomass in the 1997 tests was 310 lb/hr with rice husk, and 584 lb/hr with rice husk char

  10. Noncompetitive and Competitive Adsorption of Heavy Metals in Sulfur-Functionalized Ordered Mesoporous Carbon.

    Science.gov (United States)

    Saha, Dipendu; Barakat, Soukaina; Van Bramer, Scott E; Nelson, Karl A; Hensley, Dale K; Chen, Jihua

    2016-12-14

    In this work, sulfur-functionalized ordered mesoporous carbons were synthesized by activating the soft-templated mesoporous carbons with sulfur bearing salts that simultaneously enhanced the surface area and introduced sulfur functionalities onto the parent carbon surface. XPS analysis showed that sulfur content within the mesoporous carbons were between 8.2% and 12.9%. The sulfur functionalities include C-S, C═S, -COS, and SO x . SEM images confirmed the ordered mesoporosity within the material. The BET surface areas of the sulfur-functionalized ordered mesoporous carbons range from 837 to 2865 m 2 /g with total pore volume of 0.71-2.3 cm 3 /g. The carbon with highest sulfur functionality was examined for aqueous phase adsorption of mercury (as HgCl 2 ), lead (as Pb(NO 3 ) 2 ), cadmium (as CdCl 2 ), and nickel (as NiCl 2 ) ions in both noncompetitive and competitive mode. Under noncompetitive mode and at a pH greater than 7.0 the affinity of sulfur-functionalized carbons toward heavy metals were in the order of Hg > Pb > Cd > Ni. At lower pH, the adsorbent switched its affinity between Pb and Cd. In the noncompetitive mode, Hg and Pb adsorption showed a strong pH dependency whereas Cd and Ni adsorption did not demonstrate a significant influence of pH. The distribution coefficient for noncompetitive adsorption was in the range of 2448-4000 mL/g for Hg, 290-1990 mL/g for Pb, 550-560 mL/g for Cd, and 115-147 for Ni. The kinetics of adsorption suggested a pseudo-second-order model fits better than other models for all the metals. XPS analysis of metal-adsorption carbons suggested that 7-8% of the adsorbed Hg was converted to HgSO 4 , 14% and 2% of Pb was converted to PbSO 4 and PbS/PbO, respectively, and 5% Cd was converted to CdSO 4 . Ni was below the detection limit for XPS. Overall results suggested these carbon materials might be useful for the separation of heavy metals.

  11. Sulfur dimers adsorbed on Au(111) as building blocks for sulfur octomers formation: A density functional study

    International Nuclear Information System (INIS)

    Hernandez-Tamargo, Carlos E.; Montero-Alejo, Ana Lilian; Pujals, Daniel Codorniu; Mikosch, Hans; Hernández, Mayra P.

    2014-01-01

    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 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

  12. Sulfur dimers adsorbed on Au(111) as building blocks for sulfur octomers formation: A density functional study

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez-Tamargo, Carlos E.; Montero-Alejo, Ana Lilian [Laboratory of Computational and Theoretical Chemistry (LQCT), Faculty of Chemistry, Havana University, Havana 10400 (Cuba); Pujals, Daniel Codorniu [Higher Institute of Technologies and Applied Sciences (InSTEC), Havana 10400 (Cuba); Mikosch, Hans [Institute of Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9/E164-EC, 1060 Vienna (Austria); Hernández, Mayra P., E-mail: mayrap@imre.oc.uh.cu [Instituto de Ciencias y Tecnologías de Materiales (IMRE), Havana 10400 (Cuba)

    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.

  13. Hibiscus chlorotic ringspot virus coat protein upregulates sulfur metabolism genes for enhanced pathogen defense.

    Science.gov (United States)

    Gao, Ruimin; Ng, Florence Kai Lin; Liu, Peng; Wong, Sek-Man

    2012-12-01

    In both Hibiscus chlorotic ringspot virus (HCRSV)-infected and HCRSV coat protein (CP) agroinfiltrated plant leaves, we showed that sulfur metabolism pathway related genes-namely, sulfite oxidase (SO), sulfite reductase, and adenosine 5'-phosphosulfate kinase-were upregulated. It led us to examine a plausible relationship between sulfur-enhanced resistance (SED) and HCRSV infection. We broadened an established method to include different concentrations of sulfur (0S, 1S, 2S, and 3S) to correlate them to symptom development of HCRSV-infected plants. We treated plants with glutathione and its inhibitor to verify the SED effect. Disease resistance was induced through elevated glutathione contents during HCRSV infection. The upregulation of SO was related to suppression of symptom development induced by sulfur treatment. In this study, we established that HCRSV-CP interacts with SO which, in turn, triggers SED and leads to enhanced plant resistance. Thus, we have discovered a new function of SO in the SED pathway. This is the first report to demonstrate that the interaction of a viral protein and host protein trigger SED in plants. It will be interesting if such interaction applies generally to other host-pathogen interactions that will lead to enhanced pathogen defense.

  14. Extreme Pressure Synergistic Mechanism of Bismuth Naphthenate and Sulfurized Isobutene Additives

    Science.gov (United States)

    Xu, Xin; Hu, Jianqiang; Yang, Shizhao; Xie, Feng; Guo, Li

    A four-ball tester was used to evaluate the tribological performances of bismuth naphthenate (BiNap), sulfurized isobutene (VSB), and their combinations. The results show that the antiwear properties of BiNap and VSB are not very visible, but they possess good extreme pressure (EP) properties, particularly sulfur containing bismuth additives. Synergistic EP properties of BiNap with various sulfur-containing additives were investigated. The results indicate that BiNap exhibits good EP synergism with sulfur-containing additives. The surface analytical tools, such as X-ray photoelectron spectrometer (XPS) scanning electron microscope (SEM) and energy dispersive X-ray (EDX), were used to investigate the topography, composition contents, and depth profile of some typical elements on the rubbing surface. Smooth topography of wear scar further confirms that the additive showed good EP capacities, and XPS and EDX analyzes indicate that tribochemical mixed protective films composed of bismuth, bismuth oxides, sulfides, and sulfates are formed on the rubbing surface, which improves the tribological properties of lubricants. In particular, a large number of bismuth atoms and bismuth sulfides play an important role in improving the EP properties of oils.

  15. Sulfur-binding in recent environments: II. Speciation of sulfur and iron and implications for the occurrence of organo-sulfur compounds

    Science.gov (United States)

    Hartgers, Walter A.; Lòpez, Jordi F.; Sinninghe Damsté, Jaap S.; Reiss, Christine; Maxwell, James R.; Grimalt, Joan O.

    1997-11-01

    Speciation of iron and sulfur species was determined for two recent sediments (La Trinitat and Lake Cisó) which were deposited in environments with a high biological productivity and sulfate-reducing activity. In sediments from calcite ponds of La Trinitat an excess of reactive iron species (iron monosulfides, iron hydroxides) results in a depletion of reactive sulfur which is accompanied by a virtual absence of organo-sulfur compounds, both in low (LMW) and high molecular-weight (HMW) fractions. Small amounts of phytanyl and highly branched isoprenoid (HBI) thiophenes in the extract demonstrate that these molecules exhibit a higher reactivity towards reduced sulfur species as compared to detrital iron. Euxinic sediments from Lake Cisó are characterised by an excess of reduced sulfur species which can rapidly trap reactive iron. High concentrations of H 2S results in the formation of organo-sulfur compounds which were encountered in both LMW and HMW fractions. The major part of the organic sulfur is bound to the carbohydrate portion of woody tissues, whose presence was revealed by a specific alkylthiophene distribution in the flash pyrolysate and by Li/EtNH 2 desulfurisation of the kerogen which resulted in the solubilisation of the sulfur-enriched hemicellulose fraction. Relatively high amounts of sulfurised C 25 HBI compounds in the sediment extract of Lake Cisó reflect the incorporation of sulfur into algal derived organic matter upon early diagenesis. The combined approach of the speciation of iron and sulfur species and the molecular analysis of sedimentary fractions demonstrates that abiotic sulfur binding to organic matter occurs at the earliest stages of diagenesis under specific depositional conditions (anoxic, stratified water column) in which an excess of reduced sulfur species relative to the amount of reactive iron is a controlling factor.

  16. Sulfur containing nanoporous materials, nanoparticles, methods and applications

    Science.gov (United States)

    Archer, Lynden A.; Navaneedhakrishnan, Jayaprakash

    2018-01-30

    Sulfur containing nanoparticles that may be used within cathode electrodes within lithium ion batteries include in a first instance porous carbon shape materials (i.e., either nanoparticle shapes or "bulk" shapes that are subsequently ground to nanoparticle shapes) that are infused with a sulfur material. A synthetic route to these carbon and sulfur containing nanoparticles may use a template nanoparticle to form a hollow carbon shape shell, and subsequent dissolution of the template nanoparticle prior to infusion of the hollow carbon shape shell with a sulfur material. Sulfur infusion into other porous carbon shapes that are not hollow is also contemplated. A second type of sulfur containing nanoparticle includes a metal oxide material core upon which is located a shell layer that includes a vulcanized polymultiene polymer material and ion conducting polymer material. The foregoing sulfur containing nanoparticle materials provide the electrodes and lithium ion batteries with enhanced performance.

  17. Flow injection gas chromatography with sulfur chemiluminescence detection for the analysis of total sulfur in complex hydrocarbon matrixes.

    Science.gov (United States)

    Hua, Yujuan; Hawryluk, Myron; Gras, Ronda; Shearer, Randall; Luong, Jim

    2018-01-01

    A fast and reliable analytical technique for the determination of total sulfur levels in complex hydrocarbon matrices is introduced. The method employed flow injection technique using a gas chromatograph as a sample introduction device and a gas phase dual-plasma sulfur chemiluminescence detector for sulfur quantification. Using the technique described, total sulfur measurement in challenging hydrocarbon matrices can be achieved in less than 10 s with sample-to-sample time ideal for fast analysis or trace sulfur analysis. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Layered sulfur/PEDOT:PSS nano composite electrodes for lithium sulfur cell applications

    Science.gov (United States)

    Anilkumar, K. M.; Jinisha, B.; Manoj, M.; Pradeep, V. S.; Jayalekshmi, S.

    2018-06-01

    Lithium-Sulfur (Li-S) cells are emerging as the next generation energy storage devices owing to their impressive electrochemical properties with high theoretical specific capacity of 1675 mAh/g. Lack of electronic conductivity of sulfur, its volume expansion during high lithium intake and the shuttling effect due to the formation of soluble polysulfides are the main limitations, delaying the commercialization of this technology. To address these challenges, in the present work, the conducting polymer PEDOT:PSS is used as the covering matrix over the sulfur particles to improve their Li storage properties. The sulfur/PEDOT:PSS nanocomposite is synthesised using the hydrothermal process and its formation with the polymer coating over sulfur nanoparticles is established from the XRD, Raman spectroscopy, FE-SEM and TEM studies. The electrochemical studies show that the cells assembled using the sulfur/PEDOT:PSS nanocomposite as the cathode, with the components taken in the weight ratio of 9:1, offer a reversible capacity of 1191 mAh g-1 at 0.1C rate. These cells display stable electrochemical capacities over 200 cycles at gradually increasing current rates. The polymer layer facilitates electronic conduction and suppresses the polysulfide formation and the volume expansion of sulfur. A reversible capacity of 664 mAh g-1 is observed after 200 cycles at 1C rate with the capacity retention of 75 % of the initial stable capacity. The highlight of the present work is the possibility to achieve high discharge capacities at high C rates and the retention of a good percentage of the initial capacity over 200 cycles, for these Li-S cells.

  19. Source of arsenic-bearing pyrite in southwestern Vermont, USA: Sulfur isotope evidence

    Energy Technology Data Exchange (ETDEWEB)

    Mango, Helen, E-mail: helen.mango@castleton.edu [Department of Natural Sciences, Castleton State College, 233 South Street, Castleton, VT 05735 (United States); Ryan, Peter, E-mail: pryan@middlebury.edu [Department of Geology, Middlebury College, 276 Bicentennial Way, Middlebury, VT 05753 (United States)

    2015-02-01

    Arsenic-bearing pyrite is the source of arsenic in groundwater produced in late Cambrian and Ordovician gray and black slates and phyllites in the Taconic region of southwestern Vermont, USA. The aim of this study is to analyze the sulfur isotopic composition of this pyrite and determine if a relationship exists between pyrite δ{sup 34}S and arsenic content. Pyrite occurs in both sedimentary/diagenetic (bedding-parallel layers and framboids) and low-grade metamorphic (porphyroblast) forms, and contains up to > 2000 ppm As. The sulfur isotopic composition of arsenic-bearing pyrite ranges from − 5.2‰ to 63‰. In the marine environment, the sulfur in sedimentary pyrite becomes increasingly enriched in {sup 34}S as the geochemical environment becomes increasingly anoxic. There is a positive correlation between δ{sup 34}S and arsenic content in the Taconic pyrite, suggesting that uptake of arsenic by pyrite increased as the environment became more reducing. This increased anoxia may have been due to a rise in sea level and/or tectonic activity during the late Cambrian and Ordovician. Low-grade metamorphism appears to have little effect on sulfur isotope composition, but does correlate with lower arsenic content in pyrite. New groundwater wells drilled in this region should therefore avoid gray and black slates and phyllites that contain sedimentary/diagenetic pyrite with heavy δ{sup 34}S values. - Highlights: • Pyrite is the source of arsenic in groundwater in the Taconic region of Vermont, USA. • As-bearing pyrite δ{sup 34}S = – 5.2 to 63‰ with higher {sup 34}S as environment becomes more anoxic. • High sea level, tectonic activity create anoxia, with incorporation of As into pyrite. • New wells should avoid slate/phyllite containing sedimentary pyrite with heavy δ{sup 34}S.

  20. Source of arsenic-bearing pyrite in southwestern Vermont, USA: Sulfur isotope evidence

    International Nuclear Information System (INIS)

    Mango, Helen; Ryan, Peter

    2015-01-01

    Arsenic-bearing pyrite is the source of arsenic in groundwater produced in late Cambrian and Ordovician gray and black slates and phyllites in the Taconic region of southwestern Vermont, USA. The aim of this study is to analyze the sulfur isotopic composition of this pyrite and determine if a relationship exists between pyrite δ 34 S and arsenic content. Pyrite occurs in both sedimentary/diagenetic (bedding-parallel layers and framboids) and low-grade metamorphic (porphyroblast) forms, and contains up to > 2000 ppm As. The sulfur isotopic composition of arsenic-bearing pyrite ranges from − 5.2‰ to 63‰. In the marine environment, the sulfur in sedimentary pyrite becomes increasingly enriched in 34 S as the geochemical environment becomes increasingly anoxic. There is a positive correlation between δ 34 S and arsenic content in the Taconic pyrite, suggesting that uptake of arsenic by pyrite increased as the environment became more reducing. This increased anoxia may have been due to a rise in sea level and/or tectonic activity during the late Cambrian and Ordovician. Low-grade metamorphism appears to have little effect on sulfur isotope composition, but does correlate with lower arsenic content in pyrite. New groundwater wells drilled in this region should therefore avoid gray and black slates and phyllites that contain sedimentary/diagenetic pyrite with heavy δ 34 S values. - Highlights: • Pyrite is the source of arsenic in groundwater in the Taconic region of Vermont, USA. • As-bearing pyrite δ 34 S = – 5.2 to 63‰ with higher 34 S as environment becomes more anoxic. • High sea level, tectonic activity create anoxia, with incorporation of As into pyrite. • New wells should avoid slate/phyllite containing sedimentary pyrite with heavy δ 34 S

  1. Effect of Dietary Processed Sulfur Supplementation on Texture Quality, Color and Mineral Status of Dry-cured Ham.

    Science.gov (United States)

    Kim, Ji-Han; Ju, Min-Gu; Yeon, Su-Jung; Hong, Go-Eun; Park, WooJoon; Lee, Chi-Ho

    2015-01-01

    This study was performed to investigate the chemical composition, mineral status, oxidative stability, and texture attributes of dry-cured ham from pigs fed processed sulfur (S, 1 g/kg feed), and from those fed a basal diet (CON), during the period from weaning to slaughter (174 d). Total collagen content and soluble collagen of the S group was significantly higher than that of the control group (pham (pham from the control group, that from the S group exhibited lower springiness and gumminess; these results suggest that feeding processed sulfur to pigs can improve the quality of the texture and enhance the oxidative stability of dry-cured ham.

  2. Solvent extraction of elemental sulfur from coal and a determination of its source using stable sulfur isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Hackley, K.C.; Buchanan, D.H.; Coombs, K.; Chaven, C.; Kruse, C.W. (Eastern Illinois University, Charleston, IL (USA). Chemistry Dept.)

    1990-01-01

    Hot tetrachloroethene (perchloroethylen PCE) extracts significant amounts of elemental sulfur (S{sup o}) from weathered coals but not from pristine coals. The objective of this study was to determine whether S{sup o} extracted by PCE is an oxidation product of pyrite or whether it originates in some way from unstable, organically-bound sulfur. The isotopic composition of the PCE-extracted S{sup o} was compared to the isotopic compositions of the pyritic and the organic sulfur in a coal. The S{sup o} was shown to have an isotopic signature similar to the pyritic sulfur. Additionally, the isotopic differences observed between the pyritic, S{sup o} and sulfatic sulfur were consistent with bacterial mediated oxidation of sulfide sulfur (pyrite) as the source of both the sulfatic and elemental sulfur. 21 refs., 2 tabs.

  3. Solvent extraction of elemental sulfur from coal and a determination of its source using stable sulfur isotopes

    Science.gov (United States)

    Hackley, Keith C.; Buchanan, D.H.; Coombs, K.; Chaven, C.; Kruse, C.W.

    1990-01-01

    Hot tetrachloroethene (perchloroethylene, PCE) extracts significant amounts of elemental sulfur (So) from weathered coals but not from pristine coals. The objective of this study was to determine whether So extracted by PCE is an oxidation product of pyrite or whether it originates in some way from unstable, organically-bound sulfur. The isotopic composition of the PCE-extracted So was compared to the isotopic compositions of the pyritic and the organic sulfur in a coal. The So was shown to have an isotopic signature similar to the pyritic sulfur. Additionally, the isotopic differences observed between the pyritic, So and sulfatic sulfur were consistent with bacterial mediated oxidation of sulfide sulfur (pyrite) as the source of both the sulfatic and elemental sulfur. ?? 1990.

  4. Sulfur dioxide: foe or friend for life?

    Science.gov (United States)

    Wang, Xin-Bao; Cui, Hong; Liu, Xiaohong; Du, Jun-Bao

    2017-12-01

    Sulfur dioxide (SO₂) is a toxic gas and air pollutant. The toxic effects of SO₂ have been extensively studied. Oxidative damage due to SO₂ can occur in multiple organs. Inhaled SO₂ can also cause chromosomal aberrations, DNA damage and gene mutations in mammals. However, SO₂ can also be generated from the sulfur-containing amino acid, L-cysteine. Recent studies have shown that SO₂ has a vasorelaxant effect, and ameliorates pulmonary hypertension and vascular remodeling. SO₂ can also reduce lung injury and myocardial injury in rats. In addition, SO₂ reduces myocardial ischemia-reperfusion injury and atherosclerotic lesions. Therefore, SO₂ exerts both detrimental and protective effects in mammals. Is SO₂ a foe or friend for life?.

  5. Volatile sulfur compounds in tropical fruits

    Directory of Open Access Journals (Sweden)

    Robert J. Cannon

    2018-04-01

    Full Text Available Global production and demand for tropical fruits continues to grow each year as consumers are enticed by the exotic flavors and potential health benefits that these fruits possess. Volatile sulfur compounds (VSCs are often responsible for the juicy, fresh aroma of tropical fruits. This poses a challenge for analytical chemists to identify these compounds as most often VSCs are found at low concentrations in most tropical fruits. The aim of this review is to discuss the extraction methods, enrichment techniques, and instrumentation utilized to identify and quantify VSCs in natural products. This will be followed by a discussion of the VSCs reported in tropical and subtropical fruits, with particular attention to the odor and taste attributes of each compound. Finally, the biogenesis and enzymatic formation of specific VSCs in tropical fruits will be highlighted along with the contribution each possesses to the aroma of their respective fruit. Keywords: Tropical fruits, Volatile sulfur compounds, Extraction methods

  6. Mixed total screening for sulfur isotope

    International Nuclear Information System (INIS)

    Cui Bin; Zhao Lei; Zhan Zhaoyang; He Zhijun

    2003-01-01

    The research on modern economic geology indicates that most ore deposits formed with characters of multi-origin, multi-stage and multi-genesis. Quantificational research of Sulfur isotope origin is a difficult problem that puzzles Geochemists all along. So the formation process of an ore deposit can be taken as the mix or the superposition of multi totals, which can be described by the mathematics model of mixed total screening. In the study of mid-down Yangtze River and Dongpo ore field in Hunan province, the authors successfully applied the mathematics model of mixed total screening, quantificationally resolved the problem of Sulfur isotope origin and mineralizing matter origin, and found out the mineralizing mechanism. This is very valuable. (authors)

  7. Experimental Behavior of Sulfur Under Primitive Planetary Differentiation Processes, the Sulfide Formations in Enstatite Meteorites and Implications for Mercury.

    Science.gov (United States)

    Malavergne, V.; Brunet, F.; Righter, K.; Zanda, B.; Avril, C.; Borensztajn, S.; Berthet, S.

    2012-01-01

    Enstatite meteorites are the most reduced naturally-occuring materials of the solar system. The cubic monosulfide series with the general formula (Mg,Mn,Ca,Fe)S are common phases in these meteorite groups. The importance of such minerals, their formation, composition and textural relationships for understanding the genesis of enstatite chondrites (EC) and aubrites, has long been recognized (e.g. [1]). However, the mechanisms of formation of these sulfides is still not well constrained certainly because of possible multiple ways to produce them. We propose to simulate different models of formation in order to check their mineralogical, chemical and textural relevancies. The solubility of sulfur in silicate melts is of primary interest for planetary mantles, particularly for the Earth and Mercury. Indeed, these two planets could have formed, at least partly, from EC materials (e.g. [2, 3, 4]). The sulfur content in silicate melts depends on the melt composition but also on pressure (P), temperature (T) and oxygen fugacity fO2. Unfortunately, there is no model of general validity in a wide range of P-T-fO2-composition which describes precisely the evolution of sulfur content in silicate melts, even if the main trends are now known. The second goal of this study is to constrain the sulfur content in silicate melts under reducing conditions and different temperatures.

  8. Global Sulfur Emissions in the 1990s

    OpenAIRE

    David I. Stern

    2003-01-01

    This paper provides global and individual country estimates of sulfur emissions from 1991-2000. Raw estimates are obtained in two ways. For countries and years with published data I compile that data from the available sources. For the remaining countries and for missing years for countries with some published data, I use either the decomposition model estimated by Stern (2002), the first differences environmental Kuznets curve model estimated by Stern and Common (2001), or a simple extrapola...

  9. Comparative analysis of the mechanisms of sulfur anion oxidation and reduction by dsr operon to maintain environmental sulfur balance.

    Science.gov (United States)

    Ghosh, Semanti; Bagchi, Angshuman

    2015-12-01

    Sulfur metabolism is one of the oldest known redox geochemical cycles in our atmosphere. These redox processes utilize different sulfur anions and the reactions are performed by the gene products of dsr operon from phylogenetically diverse sets of microorganisms. The operon is involved in the maintenance of environmental sulfur balance. Interestingly, the dsr operon is found to be present in both sulfur anion oxidizing and reducing microorganisms and in both types of organisms DsrAB protein complex plays a vital role. Though there are various reports regarding the genetics of dsr operon there are practically no reports dealing with the structural aspects of sulfur metabolism by dsr operon. In our present study, we tried to compare the mechanisms of sulfur anion oxidation and reduction by Allochromatium vinosum and Desulfovibrio vulgaris respectively through DsrAB protein complex. We analyzed the modes of bindings of sulfur anions to the DsrAB protein complex and observed that for sulfur anion oxidizers, sulfide and thiosulfate are the best substrates whereas for reducers sulfate and sulfite have the best binding abilities. We analyzed the binding interaction pattern of the DsrA and DsrB proteins while forming the DsrAB protein complexes in Desulfovibrio vulgaris and Allochromatium vinosum. To our knowledge this is the first report that analyzes the differences in binding patterns of sulfur substrates with DsrAB protein from these two microorganisms. This study would therefore be essential to predict the biochemical mechanism of sulfur anion oxidation and reduction by these two microorganisms i.e., Desulfovibrio vulgaris (sulfur anion reducer) and Allochromatium vinosum (sulfur anion oxidizer). Our observations also highlight the mechanism of sulfur geochemical cycle which has important implications in future study of sulfur metabolism as it has a huge application in waste remediation and production of industrial bio-products viz. vitamins, bio-polyesters and bio

  10. A composite of hollow carbon nanospheres and sulfur-rich polymers for lithium-sulfur batteries

    Science.gov (United States)

    Zeng, Shao-Zhong; Yao, Yuechao; Zeng, Xierong; He, Qianjun; Zheng, Xianfeng; Chen, Shuangshuang; Tu, Wenxuan; Zou, Jizhao

    2017-07-01

    Lithium-sulfur batteries are the most promising candidates for future high-energy applications because of the unparalleled capacity of sulfur (1675 mAh g-1). However, lithium-sulfur batteries have limited cycle life and rate capability due to the dissolution of polysulfides and the extremely low electronic conductivity of sulfur. To solve these issues, various porous carbons including hollow carbon nanospheres (HCNs) have been used for improving the conductivity. However, these methods still suffer from polysulfides dissolution/loss owing to their weak physical adsorption to polysulfides. Herein, we introduced a covalent grafting route to composite the HCNs and the vulcanized trithiocyanuric acid (TTCA). The composite exhibits a high loading of the vulcanized TTCA by the HCNs with high surface area and large pore volume, and covalent bonds to sulfur, effectively depressing the dissolution of polysulfides. The first discharge capacity of the composite reaches 1430 mAh g-1 at 0.1 C and 1227 mAh g-1 at 0.2 C.

  11. Improved Cyclability of Liquid Electrolyte Lithium/Sulfur Batteries by Optimizing Electrolyte/Sulfur Ratio

    Directory of Open Access Journals (Sweden)

    Sheng S. Zhang

    2012-12-01

    Full Text Available A liquid electrolyte lithium/sulfur (Li/S cell is a liquid electrochemical system. In discharge, sulfur is first reduced to highly soluble Li2S8, which dissolves into the organic electrolyte and serves as the liquid cathode. In solution, lithium polysulfide (PS undergoes a series of complicated disproportionations, whose chemical equilibriums vary with the PS concentration and affect the cell’s performance. Since the PS concentration relates to a certain electrolyte/sulfur (E/S ratio, there is an optimized E/S ratio for the cyclability of each Li/S cell system. In this work, we study the optimized E/S ratio by measuring the cycling performance of Li/S cells, and propose an empirical method for determination of the optimized E/S ratio. By employing an electrolyte of 0.25 m LiSO3CF3-0.25 m LiNO3 dissolved in a 1:1 (wt:wt mixture of dimethyl ether (DME and 1,3-dioxolane (DOL in an optimized E/S ratio, we show that the Li/S cell with a cathode containing 72% sulfur and 2 mg cm−2 sulfur loading is able to retain a specific capacity of 780 mAh g−1 after 100 cycles at 0.5 mA cm−2 between 1.7 V and 2.8 V.

  12. Formation of CuxS Layers on Polypropylene Sulfurized by Molten Sulfur

    Directory of Open Access Journals (Sweden)

    Rasa ALABURDAITĖ

    2011-11-01

    Full Text Available The processes of formation of electrically conductive layers of copper sulfides CuxS by the sorption-diffusion method on polypropylene (PP using molten sulfur as sulfurizing agent was investigated. The amount of sorbed sulfur increased with the increase of the duration of treatment. Copper sulfide layers were formed on the surface of polypropylene after the treatment of sulfurized polymer with Cu(II/I salt solution. The amount of copper sulfide in layer increased with the increase of treatment duration in copper salt solution. XRD spectra of PP films treated for 3 min with molten sulfur and then with Cu(II/I salt solution for the different time showed that the copper sulfide phases, mostly digenite, Cu2-xS and a-chalcocite, Cu2S were formed in the layers. Electromotive force measurement results confirmed the composition of formed CuxS layers on PP. The phase composition of layers also changed after the annealing. The value of electrical resistance of copper sulfide layers on PP varied from 20 W/cm2 to 80 W/cm2 and after annealing at 80 °C - in the interval of 10 W/cm2 - 60 W/cm2.http://dx.doi.org/10.5755/j01.ms.17.4.776

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

    Science.gov (United States)

    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.

  14. Growth of Thiobacillus ferrooxidans on elemental sulfur

    International Nuclear Information System (INIS)

    Espejo, R.T.; Romero, P.

    1987-01-01

    Growth kinetics of Thiobacillus ferrooxidans in batch cultures, containing prills of elementary sulfur as the sole energy source, were studied by measuring the incorporation of radioactive phosphorus in free and adsorbed bacteria. The data obtained indicate an initial exponential growth of the attached bacteria until saturation of the susceptible surface was reached, followed by a linear release of free bacteria due to successive replication of a constant number of adsorbed bacteria. These adsorbed bacteria could continue replication provided the colonized prills were transferred to fresh medium each time the stationary phase was reached. The bacteria released from the prills were unable to multiply, and in the medium employed they lost viability with a half-live of 3.5 days. The spreading of the progeny on the surface was followed by staining the bacteria on the prills with crystal violet; this spreading was not uniform but seemed to proceed through distortions present in the surface. The specific growth rate of T. ferrooxidans ATCC 19859 was about 0.5 day -1 , both before and after saturation of the sulfur surface. The growth of adsorbed and free bacteria in medium containing both ferrous iron and elementary sulfur indicated that T. ferrooxidans can simultaneously utilize both energy sources

  15. Biological effects data: Fluoride and sulfur dioxide

    Energy Technology Data Exchange (ETDEWEB)

    McMechan, K.J. (ed.); Holton, R.L.; Ulbricht, R.J.; Morgan , J.B.

    1975-04-01

    The Alumax Pacific Aluminum Corporation has proposed construction of an aluminum reduction facility near Youngs Bay at Warrenton, Oregon. This report comprises one part of the final report to Alumax on a research project entitled, Physical, Chemical and Biological Studies of Youngs Bay.'' It presents data pertaining to the potential biological effects of fluoride and sulfur dioxide, two potentially hazardous plant-stack emissions, on selected aquatic species of the area. Companion volumes provide a description of the physical characteristics the geochemistry, and the aquatic animals present in Youngs Bay and adjacent ecosystems. An introductory volume provides general information and maps of the area, and summarizes the conclusions of all four studies. The data from the two phases of the experimental program are included in this report: lethal studies on the effects of selected levels of fluoride and sulfur dioxide on the survival rate of eleven Youngs Bay faunal species from four phyla, and sublethal studies on the effects of fluoride and sulfur dioxide on the rate of primary production of phytoplankton. 44 refs., 18 figs., 38 tabs.

  16. Sulfur status in long distance runners

    International Nuclear Information System (INIS)

    Kovacs, L; Zamboni, C; Lourenço, T; Macedo, D

    2015-01-01

    In sports medicine, sulfur plays an important role and its deficiency can cause muscle injury affecting the performance of the athletes. However, its evaluation is unusual in conventional clinical practice. In this study the sulfur levels were determined in Brazilian amateur athlete's blood using Neutron Activation Analyses (NAA) technique. Twenty six male amateur runners, age 18 to 36 years, participated of this study. The athletes had a balanced diet, without multivitamin/mineral supplements. The blood collection was performed at LABEX (Laboratoriode Bioquimica do Exercicio, UNICAMP-SP) and the samples were irradiated for 300 seconds in a pneumatic station in the nuclear reactor (IEA-R1, 3-4.5MW, pool type) at IPEN/CNEN-SP. The results were compared with the control group (subjects of same age but not involved with physical activities) and showed that the sulfur concentration was 44% higher in amateurs athletes than control group. These data can be considered for preparation of balanced diet, as well as contributing for proposing new protocols of clinical evaluation. (paper)

  17. Sulfur status in long distance runners

    Science.gov (United States)

    Kovacs, L.; Zamboni, C.; Lourenço, T.; Macedo, D.

    2015-07-01

    In sports medicine, sulfur plays an important role and its deficiency can cause muscle injury affecting the performance of the athletes. However, its evaluation is unusual in conventional clinical practice. In this study the sulfur levels were determined in Brazilian amateur athlete's blood using Neutron Activation Analyses (NAA) technique. Twenty six male amateur runners, age 18 to 36 years, participated of this study. The athletes had a balanced diet, without multivitamin/mineral supplements. The blood collection was performed at LABEX (Laboratoriode Bioquimica do Exercicio, UNICAMP-SP) and the samples were irradiated for 300 seconds in a pneumatic station in the nuclear reactor (IEA-R1, 3-4.5MW, pool type) at IPEN/CNEN-SP. The results were compared with the control group (subjects of same age but not involved with physical activities) and showed that the sulfur concentration was 44% higher in amateurs athletes than control group. These data can be considered for preparation of balanced diet, as well as contributing for proposing new protocols of clinical evaluation.

  18. Sulfur biogeochemistry of oil sands composite tailings

    Energy Technology Data Exchange (ETDEWEB)

    Warren, Lesley; Stephenson, Kate [Earth Sciences, McMaster University (Canada)], email: warrenl@mcmaster.ca; Penner, Tara [Syncrude Environmental Research (Canada)

    2011-07-01

    This paper discusses the sulfur biogeochemistry of oil sands composite tailings (CT). The Government of Alberta is accelerating reclamation activities on composite tailings. As a CT pilot reclamation operation, Syncrude is currently constructing the first freshwater fen. Minor unpredicted incidents with H2S gas released from the dewatering process associated with these reclamations have been reported. The objective of this study is to ascertain the connection between microbial activity and H2S generation within CT and to assess the sulfur biogeochemistry of untreated and treated (fen) CT over seasonal and annual timescales. The microbial geochemical interactions taking place are shown using a flow chart. CT is composed of gypsum, sand, clay and organics like naphthenic acids and bitumen. Sulfur and Fe cycling in mining systems and their microbial activities are presented. The chemistry and the processes involved within CT are also given along with the results. It can be said that the diverse Fe and S metabolizing microorganisms confirm the ecology involved in H2S dynamics.

  19. Action of sulfurous oxide on plants

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, J

    1873-01-01

    In order to ascertain which trees best withstand the action of sulfurous oxide, and are, therefore, best suited for planting in neighborhoods where this gas is given off, young trees of various kinds growing in the open ground, were exposed under glass shades to air containing quantities of sulfurous oxide, varying from 1/10,000 to 1/70,000, under circumstances most favorable to its action, viz., in direct sunlight and after having been watered. The sensitiveness of the leaves was carefully noticed, and also the power which the trees possessed of compensating for injury by the reproduction of leaves; this was found to vary considerably in different trees, as did also the resisting power in the first case. Alder, sycamore, ash, and especially maple, are recommended for growth where exposed to smoke containing sulfurous oxide; next follow birch, hornbeam, and oak, and last, beech. The pines did not give constant results, but in nature they suffer more than other trees, and this is owing to the fact that, although their sensitiveness at first is less than that of other trees, their power of restoring lost leaves is much less.

  20. Global sulfur emissions from 1850 to 2000.

    Science.gov (United States)

    Stern, David I

    2005-01-01

    The ASL database provides continuous time-series of sulfur emissions for most countries in the World from 1850 to 1990, but academic and official estimates for the 1990s either do not cover all years or countries. This paper develops continuous time series of sulfur emissions by country for the period 1850-2000 with a particular focus on developments in the 1990s. Global estimates for 1996-2000 are the first that are based on actual observed data. Raw estimates are obtained in two ways. For countries and years with existing published data I compile and integrate that data. Previously published data covers the majority of emissions and almost all countries have published emissions for at least 1995. For the remaining countries and for missing years for countries with some published data, I interpolate or extrapolate estimates using either an econometric emissions frontier model, an environmental Kuznets curve model, or a simple extrapolation, depending on the availability of data. Finally, I discuss the main movements in global and regional emissions in the 1990s and earlier decades and compare the results to other studies. Global emissions peaked in 1989 and declined rapidly thereafter. The locus of emissions shifted towards East and South Asia, but even this region peaked in 1996. My estimates for the 1990s show a much more rapid decline than other global studies, reflecting the view that technological progress in reducing sulfur based pollution has been rapid and is beginning to diffuse worldwide.

  1. Nanostructured nitrogen-doped mesoporous carbon derived from polyacrylonitrile for advanced lithium sulfur batteries

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ying; Zhao, Xiaohui; Chauhan, Ghanshyam S. [Department of Chemical Engineering and Research Institute for Green Energy Convergence Technology, Gyeongsang National University, 501 Jinju-daero, Jinju 660-701 (Korea, Republic of); Ahn, Jou-Hyeon, E-mail: jhahn@gnu.ac.kr [Department of Chemical Engineering and Research Institute for Green Energy Convergence Technology, Gyeongsang National University, 501 Jinju-daero, Jinju 660-701 (Korea, Republic of); Department of Materials Engineering and Convergence Technology and RIGET, Gyeongsang National University, 501 Jinju-daero, Jinju 660-701 (Korea, Republic of)

    2016-09-01

    Graphical abstract: Well-ordered nitrogen-doped mesoporous carbon materials were prepared by in-situ polymerization of polyacrylonitrile in SBA-15 template. The composite of sulfur and nitrogen-doped carbon was successfully used as a cathode material for lithium sulfur battery. - Highlights: • N-doped mesoporous carbons were prepared with PAN as carbon source. • Highly ordered pore system facilitates sulfur loading. • Ladder-type carbon matrix provides good structural stability for confining sulfur. • N-doping ensures an improved absorbability of soluble polysulfides. - Abstract: Nitrogen doping in carbon matrix can effectively improve the wettability of electrolyte and increase electric conductivity of carbon by ensuring fast transfer of ions. We synthesized a series of nitrogen-doped mesoporous carbons (CPANs) via in situ polymerization of polyacrylonitrile (PAN) in SBA-15 template followed by carbonization at different temperatures. Carbonization results in the formation of ladder structure which enhances the stability of the matrix. In this study, CPAN-800, carbon matrix synthesized by the carbonization at 800 °C, was found to possess many desirable properties such as high specific surface area and pore volume, moderate nitrogen content, and highly ordered mesoporous structure. Therefore, it was used to prepare S/CPAN-800 composite as cathode material in lithium sulfur (Li-S) batteries. The S/CPAN-800 composite was proved to be an excellent material for Li-S cells which delivered a high initial discharge capacity of 1585 mAh g{sup −1} and enhanced capacity retention of 862 mAh g{sup −1} at 0.1 C after 100 cycles.

  2. The growing contribution of sulfur emissions from ships in Asian waters, 1988-1995

    Science.gov (United States)

    Streets, David G.; Guttikunda, Sarath K.; Carmichael, Gregory R.

    International shipping is a major source of sulfur emissions in Asia. Because the fuel oil used by ships is high in sulfur, the resulting emissions of SO 2 are large and contribute as much as 20% to the atmospheric loading in the vicinity of ports and heavily traveled waterways. Because of the rapid growth of Asian economies in the 1980s and early 1990s, it is estimated that shipping trade grew by an average of 5.4% per year between 1988 and 1995; in particular, crude oil shipments to Asian countries other than Japan grew by an average of 11.4% per year. The emissions of SO 2 from shipping are estimated to have grown by 5.9% per year between 1988 and 1995, rising from 545 Gg in 1988 to 817 Gg in 1995. This study uses the ATMOS atmospheric transport and deposition model to study the effects of these emissions, both in absolute terms and relative to land-based emissions , on wet and dry deposition of sulfur. Southeast Asia is most heavily affected by emissions from ships, particularly Sumatra, peninsular Malaysia, and Singapore, which routinely receive in excess of 10% of their deposition from ships. A strong seasonal component is also observed, with large areas of Southeast Asia and coastal Japan receiving sulfur deposition that exceeds 10 mg S m -2 season -1. Deposition is at least 25% higher in summer and fall than in winter and spring. Peak values of 25-50 mg S m -2 season -1 are calculated for winter in the Strait of Malacca. This work suggests a need to introduce policies to reduce the sulfur content of marine fuels or otherwise reduce emissions of SO 2 from ships in Asian waters.

  3. In situ tribochemical sulfurization of molybdenum oxide nanotubes.

    Science.gov (United States)

    Rodríguez Ripoll, Manel; Tomala, Agnieszka; Gabler, Christoph; DraŽić, Goran; Pirker, Luka; Remškar, Maja

    2018-02-15

    MoS 2 nanoparticles are typically obtained by high temperature sulfurization of organic and inorganic precursors under a S rich atmosphere and have excellent friction reduction properties. We present a novel approach for making the sulfurization unnecessary for MoO 3 nanotubes during the synthesis process for friction and wear reduction applications while simultaneously achieving a superb tribological performance. To this end, we report the first in situ sulfurization of MoO 3 nanotubes during sliding contact in the presence of sulfur-containing lubricant additives. The sulfurization leads to the tribo-chemical formation of a MoS 2 -rich low-friction tribofilm as verified using Raman spectroscopy and can be achieved both during sliding contact and under extreme pressure conditions. Under sliding contact conditions, MoO 3 nanotubes in synergy with sulfurized olefin polysulfide and pre-formed zinc dialkyl dithiophosphate tribofilms achieve an excellent friction performance. Under these conditions, the tribochemical sulfurization of MoO 3 nanotubes leads to a similar coefficient of friction to the one obtained using a model nanolubricant containing MoS 2 nanotubes. Under extreme pressure conditions, the in situ sulfurization of MoO 3 nanotubes using sulfurized olefin polysulfide results in a superb load carrying capacity capable of outperforming MoS 2 nanotubes. The reason is that while MoO 3 nanotubes are able to continuously sulfurize during sliding contact conditions, MoS 2 nanotubes progressively degrade by oxidation thus losing lubricity.

  4. The analysis of thermoplastic characteristics of special polymer sulfur composite

    Science.gov (United States)

    Książek, Mariusz

    2017-01-01

    Specific chemical environments step out in the industry objects. Portland cement composites (concrete and mortar) were impregnated by using the special polymerized sulfur and technical soot as a filler (polymer sulfur composite). Sulfur and technical soot was applied as the industrial waste. Portland cement composites were made of the same aggregate, cement and water. The process of special polymer sulfur composite applied as the industrial waste is a thermal treatment process in the temperature of about 150-155°C. The result of such treatment is special polymer sulfur composite in a liquid state. This paper presents the plastic constants and coefficients of thermal expansion of special polymer sulfur composites, with isotropic porous matrix, reinforced by disoriented ellipsoidal inclusions with orthotropic symmetry of the thermoplastic properties. The investigations are based on the stochastic differential equations of solid mechanics. A model and algorithm for calculating the effective characteristics of special polymer sulfur composites are suggested. The effective thermoplastic characteristics of special polymer sulfur composites, with disoriented ellipsoidal inclusions, are calculated in two stages: First, the properties of materials with oriented inclusions are determined, and then effective constants of a composite with disoriented inclusions are determined on the basis of the Voigt or Rice scheme. A brief summary of new products related to special polymer sulfur composites is given as follows: Impregnation, repair, overlays and precast polymer concrete will be presented. Special polymer sulfur as polymer coating impregnation, which has received little attention in recent years, currently has some very interesting applications.

  5. Dynamic transition of chemolithotrophic sulfur-oxidizing bacteria in response to amendment with nitrate in deposited marine sediments

    Directory of Open Access Journals (Sweden)

    Tomo eAoyagi

    2015-05-01

    Full Text Available Although environmental stimuli are known to affect the structure and function of microbial communities, their impact on the metabolic network of microorganisms has not been well investigated. Here, geochemical analyses, high-throughput sequencing of 16S rRNA genes and transcripts, and isolation of potentially relevant bacteria were carried out to elucidate the anaerobic respiration processes stimulated by nitrate (20 mM amendment of marine sediments. Marine sediments deposited by the Great East Japan Earthquake in 2011 were incubated anaerobically in the dark at 25°C for 5 days. Nitrate in slurry water decreased gradually for 2 days, then more rapidly until its complete depletion at day 5; production of N2O followed the same pattern. From day 2 to 5, the sulfate concentration increased and the sulfur content in solid-phase sediments significantly decreased. These results indicated that denitrification and sulfur oxidation occurred simultaneously. Illumina sequencing revealed the proliferation of known sulfur oxidizers, i.e., Sulfurimonas spp. and Chromatiales bacteria, which accounted for approximately 43.5% and 14.8% of the total population at day 5, respectively. They also expressed 16S rRNA to a considerable extent, whereas the other microorganisms, e.g., iron(III reducers and methanogens, became metabolically active at the end of the incubation. Extinction dilution culture in a basal-salts medium supplemented with sulfur compounds and nitrate successfully isolated the predominant sulfur oxidizers: Sulfurimonas sp. strain HDS01 and Thioalkalispira sp. strain HDS22. Their 16S rRNA genes showed 95.2−96.7% sequence similarity to the closest cultured relatives and they grew chemolithotrophically on nitrate and sulfur. Novel sulfur-oxidizing bacteria were thus directly involved in carbon fixation under nitrate-reducing conditions, activating anaerobic respiration processes and the reorganization of microbial communities in the deposited marine

  6. Sulfur isotopes in coal constrain the evolution of the Phanerozoic sulfur cycle

    DEFF Research Database (Denmark)

    Canfield, Donald Eugene

    2013-01-01

    Sulfate is the second most abundant anion (behind chloride) in modern seawater, and its cycling is intimately coupled to the cycling of organic matter and oxygen at the Earth’s surface. For example, the reduction of sulfide by microbes oxidizes vast amounts of organic carbon and the subsequent......, these compositions do not deviate substantially from the modern surface-water input to the oceans. When applied to mass balance models, these results support previous interpretations of sulfur cycle operation and counter recent suggestions that sulfate has been a minor player in sulfur cycling through...... reaction of sulfide with iron produces pyrite whose burial in sediments is an important oxygen source to the atmosphere. The concentrations of seawater sulfate and the operation of sulfur cycle have experienced dynamic changes through Earth’s history, and our understanding of this history is based mainly...

  7. Effect of air pollution by copper, sulfuric acid and fertilizer factories on plants at Harjavalta, West Finland

    Energy Technology Data Exchange (ETDEWEB)

    Laaksovirta, K; Silvola, J

    1975-01-01

    The most sensitive index of air pollution proved to be the sulfur content of needles of the Scots pine; the normal contents were reached at a distance of 20-30 km from the factories. The industrial site lies in a lichen desert (8.8 km/sup 2/), outside which is a transitional zone (52 km/sup 2/). The pine damage area coincides almost exactly with the lichen desert. The order of susceptibility of the dwarf shrubs studied proved to be: Calluna vulgaris (least tolerant), Empetrum nigrum, Vaccinium vitis-idaea and Arctostaphylos uva-ursi. The acidity of the soil had not changed very much. The acidity of the pine bark had decreased and the sulfur and phosphorus contents of the bark had risen between the factories and the limit of the lichen desert, because of fertilizer dust. 25 references, 9 figures, 1 table.

  8. Sandwich-like graphene-mesoporous carbon as sulfur host for enhanced lithium-sulfur batteries

    Science.gov (United States)

    Tian, Ting; Li, Bin; Zhu, Mengqi; Liu, Jianhua; Li, Songmei

    2017-10-01

    Graphene-mesoporous carbon/sulfur composites (G-MPC/S) were constructed by melt-infiltration of sulfur into graphene-mesoporous carbon which was synthesized by soft template method. The SEM and BET results of the graphene-mesoporous carbon show that the as-prepared sandwich-like G-MPC composites with a unique microporous-mesoporous structure had a high specific surface area of 554.164 m2 · g-1 and an average pore size of about 13 nm. The XRD analysis presents the existence of orthorhombic sulfur in the G-MPC/S composite, which indicates the complete infiltration of sulfur into the pores of the G-MPC. When the graphene-mesoporous carbon/surfur composites (G-MPC/S) with 53.9 wt.% sulfur loading were used as the cathode for lithium-sulfur (Li-S) batteries, it exhibited an outstanding electrochemical performance including excellent initial discharge specific capacity of 1393 mAh · g-1 at 0.1 °C, high cycle stability (731 mAh · g-1 at 200 cycles) and good rate performance (1038 mAh · g-1, 770 mAh · g-1, 518 mAh · g-1 and 377 mAh · g-1 at 0.1 °C, 0.2 °C, 0.5 °C and 1 °C, respectively), which suggested the important role of the G-MPC composite in providing more electrons and ions channels, in addition, the shuttle effect caused by the dissolved polysulfide was also suppressed.

  9. Reduced recombination in a surface-sulfurized Cu(InGa)Se2 thin-film solar cell

    Science.gov (United States)

    Kim, Shinho; Nishinaga, Jiro; Kamikawa, Yukiko; Ishizuka, Shogo; Nagai, Takehiko; Koida, Takashi; Tampo, Hitoshi; Shibata, Hajime; Matsubara, Koji; Niki, Shigeru

    2018-05-01

    This study demonstrates surface sulfurization effects on Cu(InGa)Se2 (CIGSe) thin-film solar cells with a single back-graded band gap. Single back-graded CIGSe thin films were prepared via a three-stage process in a high-vacuum molecular beam epitaxial growth chamber and were subsequently annealed in a tube furnace under environmental conditions with H2S gas. After sulfurization, an ∼80- to ∼100-nm-thick CuIn(SSe)2 layer with significantly small Ga contents (CISSe:Ga) was formed on the CIGSe layer. The newly formed CISSe:Ga layer exhibited graded S contents from surface to bulk, thus resulting in a front-graded band gap. In addition, CISSe:Ga was covered with S-enriched CISSe region that was extended from the surface to a depth of a few nm and was depleted of Ga. A device with the sulfurized CIGSe showed reduced recombination at the buffer–absorber interface, in space-charge region and in bulk. Consequently, the open circuit voltage increased from 0.58 V (in the non-sulfurized case) to 0.66 V, and the conversion efficiency improved from 15.5 to 19.4%. This large improvement is caused by the front graded band gap at the surface and the hole-blocking barrier, which suppress recombination at the CdS/CISSe:Ga interface. In addition, sulfurization followed by KF post-deposition treatment (PDT) increased the efficiency to 20.1%. Compared to the untreated sulfurized device, the KF-PDT device delivered an increased carrier lifetime and reduced the recombination in bulk probably because the defects were passivated by the K, which penetrated into the bulk region.

  10. The Role of Sulfur in the Synthesis of Novel Carbon Morphologies: From Covalent Y-junctions to Sea Urchin?like Structures

    Energy Technology Data Exchange (ETDEWEB)

    Sumpter, Bobby G [ORNL; Romo Herrera, Jose M [ORNL; Cruz Silva, Eduardo [ORNL; Meunier, Vincent [ORNL; Terrones Maldonado, Humberto [ORNL; Smith, David J [Arizona State University; Cullen, David A [Arizona State University; Terrones Maldonado, Mauricio [ORNL

    2009-01-01

    In this paper we show how sulfur-assisted CVD synthesis of carbon nanostructures is very sensitive to local conditions (such as the local amount of S or the feeding rate) during chemical reaction. Sulfur not only acts on the catalyst but also on its diffusion and incorporation into the resulting carbon nanostructure. A detailed synthesis study with extensive analytical and microscopy evidence for a wide range of morphologies reveals the presence of sulfur in the metallic catalyst and even in the carbon body of nanostructures obtained under the same CVD conditions. These drastic changes can be correlated to carrier gas flux, sulfur content, temperature and catalyst composition. Five different types of covalent Y-junctions ranging from Y-junctions with arms of micrometers in diameter, Y-junctions of cone-stacked carbon cylinders to concentric cylinders multi-walled CNTs Y-junctions can be obtained. In addition, unique sea urchin shaped nanostructures are observed under specific synthesis conditions.

  11. The application of an isotopic ratio technique to a study of the atmospheric oxidation of sulfur dioxide in the plume from a coal fired power plant

    International Nuclear Information System (INIS)

    Newman, L.; Forrest, J.; Manowitz, B.

    1975-01-01

    The extent of oxidation of sulfur dioxide to sulfate in the plume of a coal fired plant has been studied by using sampling with a single engine aircraft. A technique employing isotopic ratio measurements was utilized in conjunction with simultaneous concentration measurements of sulfur dioxide and sulfate. The use of sulfur hexafluroide as a conservative tracer was explored. The heterogeneous mechanism postulated in an oil fired plume study appears to pertain to the coal fired plume. However, the extent of oxidation seldom exceeded 5% and is limited by the relatively low particulate content of the coal fired plume. Evidence is presented for the apparent dropping out of sulfate from the plume. Implications pertaining to the ambient oxidation of sulfur dioxide are presented. (author)

  12. Sulfur (32S, 33S, 34S, 36S) and oxygen (16O, 17O, 18O) isotopi primary sulfate produced from combustion processes

    International Nuclear Information System (INIS)

    Lee, C.C.W.; Savarino, J.; Thiemens, M.H.; Cachier, H.

    2002-01-01

    The recent discovery of an anomalous enrichment in 17 O isotope in atmospheric sulfate has opened a new way to investigate the oxidation pathways of sulfur in the atmosphere. From laboratory investigations, it has been suggested that the wet oxidation of sulfur in rain droplets was responsible for the excess 17 O. In order to confirm this theory, sulfur and oxygen isotope ratios of different primary sulfates produced during fossil fuel combustion have been investigated and are reported. None of these samples exhibits any anomalous oxygen or sulfur isotopic content, as compared to urban sulfate aerosols. These results, in agreement with the laboratory investigations, reinforce the idea of an aqueous origin for the oxygen-17 anomaly found in tropospheric sulfates

  13. Reduction of sulphur dioxide emissions by pyrolysis reduction of the burning sulfur of coal, applied in the power station 'Maritsa-East 3'

    International Nuclear Information System (INIS)

    Lyutskanov, L.; Dushanov, D.

    1999-01-01

    A study for applying of the new method for reduction of the sulfur content in solid fuel reported at the Energy Forum '98 has been carried out. The calculations for using this method at the power station 'Maritsa-East 3' were made. The advantages compared to the conventional methods for removing of SO 2 from flue gases are reported. The application of this method reduces the emissions of SO 2 with 83-85%. The heat saved is equal to the heat from 13.8% of the coal. The tar obtained after removing of sulfur can be used as fuel. The expenses for transport and treatment of limestone and of obtained gypsum (needed at the conventional methods for removing the sulfur) are eliminated. The capital investments needed are smaller because of the 25-30 times smaller volume of the equipment for sulfur reduction

  14. Crystal structure of 200 K-superconducting phase in sulfur hydride system

    Energy Technology Data Exchange (ETDEWEB)

    Einaga, Mari; Sakata, Masafumi; Ishikawa, Takahiro; Shimizu, Katsuya [KYOKUGEN, Graduate School of Engineering Science, Osaka Univ. (Japan); Eremets, Mikhail; Drozdov, Alexander; Troyan, Ivan [Max Planck Institut fuer Chemie, Mainz (Germany); Hirao, Naohisa; Ohishi, Yasuo [JASRI/SPring-8, Hyogo (Japan)

    2016-07-01

    Superconductivity with the critical temperature T{sub c} above 200 K has been recently discovered by compression of H{sub 2}S (or D{sub 2}S) under extreme pressure. It was proposed that these materials decompose under high pressure to elemental sulfur and hydride with higher content of hydrogen which is responsible for the high temperature superconductivity. In this study, we have investigated that the crystal structure of the superconducting compressed H{sub 2}S and D{sub 2}S by synchrotron x-ray diffraction measurements combined with electrical resistance measurements at room and low temperatures. We found that the superconducting phase is in good agreement with theoretically predicted body-centered cubic structure, and coexists with elemental sulfur, which claims that the formation of 3H{sub 2}S → 2H{sub 3}S + S is occured under high pressure.

  15. Carbon/Sulfur Composite Cathodes for Flexible Lithium/Sulfur Batteries: Status and Prospects

    International Nuclear Information System (INIS)

    Zhao, Yan; Zhang, Yongguang; Bakenova, Zagipa; Bakenov, Zhumabay

    2015-01-01

    High specific energy and low cost flexible lithium/sulfur batteries have attracted significant attention as a promising power source to enable future flexible and wearable electronic devices. Here, we review recent progress in the development of free-standing sulfur composite cathodes, with special emphasis on electrode material selectivity and battery structural design. The mini-review is organized based on the dimensionality of different scaffold materials, namely one-dimensional carbon nanotube (CNT), two-dimensional graphene, and three-dimensional CNT/graphene composite, respectively. Finally, the opportunities and perspectives of the future research directions are discussed.

  16. Effects on the forest of sulfur dioxide from a sulfur fire near Edson, Alberta

    Energy Technology Data Exchange (ETDEWEB)

    Hocking, D

    1975-01-01

    Sulfur was burnt in a sanitary landfill during August 9 and 10, 1974. Resulting sulfur dioxide impinged on the surrounding mixed forest for 29 h. About 4 ha of forest displayed visible injury symptoms of varying intensity soon after. However, only .4 ha remained permanently injured the next season. Here, white spruce (Picea glauca (Moench) Voss) and scattered individuals of balsam poplar (Populus balsamifera L.), alder (Alnus tenuifolia Nutt.), and trembling aspen (Populus tremuloides Michx.) were killed. This report describes the extent of injury, relative sensitivities of affected plant species, and recovery in the spring in 1975.

  17. Comparative study on liquefaction of creosote and chromated copper arsenate (CCA)-treated wood and untreated southern pine wood: effects of acid catalyst content, liquefaction time, temperature, and phenol to wood ratio

    Science.gov (United States)

    Hui Pan; Chung-Yun Hse; Todd F. Shupe

    2009-01-01

    Creosote- and chromated copper arsenate (CCA)-treated wood waste and untreated southern pine wood were liquefied with phenol and sulfuric acid. The effects of sulfuric acid content, liquefaction time, liquefaction temperature, and phenol to wood ratio on liquefaction rate (i.e., wood residue content) were investigated and analyzed by analysis of variance (...

  18. Advertising Content

    OpenAIRE

    Simon P. Anderson; Régis Renault

    2002-01-01

    Empirical evidence suggests that most advertisements contain little direct informa- tion. Many do not mention prices. We analyze a firm'ss choice of advertising content and the information disclosed to consumers. A firm advertises only product informa- tion, price information, or both; and prefers to convey only limited product information if possible. Extending the "persuasion" game, we show that quality information takes precedence over price information and horizontal product information.T...

  19. Menaquinone-7 in the reaction center complex of the green sulfur bacterium Chlorobium vibrioforme functions as the electron acceptor A1

    DEFF Research Database (Denmark)

    Kjaer, B; Frigaard, N-U; Yang, F

    1998-01-01

    Photosynthetically active reaction center complexes were prepared from the green sulfur bacterium Chlorobium vibrioforme NCIMB 8327, and the content of quinones was determined by extraction and high-performance liquid chromatography. The analysis showed a stoichiometry of 1.7 molecules of menaqui......Photosynthetically active reaction center complexes were prepared from the green sulfur bacterium Chlorobium vibrioforme NCIMB 8327, and the content of quinones was determined by extraction and high-performance liquid chromatography. The analysis showed a stoichiometry of 1.7 molecules...

  20. Sulfur metabolism in the extreme acidophile Acidithiobacillus caldus

    Directory of Open Access Journals (Sweden)

    Stefanie eMangold

    2011-02-01

    Full Text Available Given the challenges to life at low pH, an analysis of inorganic sulfur compound oxidation was initiated in the chemolithoautotrophic extremophile Acidithiobacillus caldus. A. caldus is able to metabolize elemental sulfur and a broad range of inorganic sulfur compounds. It has been implicated in the production of environmentally damaging acidic solutions as well as participating in industrial bioleaching operations where it forms part of microbial consortia used for the recovery of metal ions. Based upon the recently published A. caldus type strain genome sequence, a bioinformatic reconstruction of elemental sulfur and inorganic sulfur compound metabolism predicted genes included: sulfide quinone reductase (sqr, tetrathionate hydrolase (tth, two sox gene clusters potentially involved in thiosulfate oxidation (soxABXYZ, sulfur oxygenase reductase (sor, and various electron transport components. RNA transcript profiles by semi-quantitative reverse transcription PCR suggested up-regulation of sox genes in the presence of tetrathionate. Extensive gel based proteomic comparisons of total soluble and membrane enriched protein fractions during growth on elemental sulfur and tetrathionate identified differential protein levels from the two Sox clusters as well as several chaperone and stress proteins up-regulated in the presence of elemental sulfur. Proteomics results also suggested the involvement of heterodisulfide reductase (HdrABC in A. caldus inorganic sulfur compound metabolism. A putative new function of Hdr in acidophiles is discussed. Additional proteomic analysis evaluated protein expression differences between cells grown attached to solid, elemental sulfur versus planktonic cells. This study has provided insights into sulfur metabolism of this acidophilic chemolithotroph and gene expression during attachment to solid elemental sulfur.

  1. Single and multiple ionization of sulfur atoms by electron impact

    International Nuclear Information System (INIS)

    Ziegler, D.L.

    1982-01-01

    Laboratory measurements of the cross sections for single, double, triple, and quadruple ionization of sulfur atoms by electron impact are presented for collision energies from threshold to 500 eV. The cross sections for single ionization of sulfur are measured relative to those of several elements whose absolute cross sections for single ionization are known. Cross sections for each multiple ionization process are then measured relative to those for single ionization. The configuration and operation of the apparatus for these measurements are described. The possible effects of excited sulfur reactants are examined, and the reported cross sections are felt to be characteristic of ground state sulfur atoms

  2. Sub-aqueous sulfur volcanos at Waiotapu, New Zealand

    Energy Technology Data Exchange (ETDEWEB)

    Grimes, S.; Rickard, D. [University of Wales, Cardiff (United Kingdom). Dept. of Earth Sciences; Browne, P.; Simmons, S. [University of Auckland (New Zealand). Geothermal Institute and Geology Dept.; Jull, T. [University of Arizona, Tucson (United States). AMS Facility

    1999-12-01

    Exhumed, sub-aqueous sulfur mounds occur in the Waiotapu geothermal area, New Zealand. The extinct mounds are < 2 m high and composed of small (< 0.5 cm) hollow spheres, and occasional teardrop-shaped globules. They are located within a drained valley that until recently was connected to Lake Whangioterangi. They were formed a maximum of 820 {+-} 80 years BP as a result of the rapid sub-aqueous deposition of sulfur globules, formed when fumarolic gases discharged through molten sulfur pools. Similar globules are now being formed by the discharge of fumarolic gases through a sub-aqueous molten sulfur pool in Lake Whangioterangi. (author)

  3. Sulfur based electrode materials for secondary batteries

    Science.gov (United States)

    Hao, Yong

    Developing next generation secondary batteries has attracted much attention in recent years due to the increasing demand of high energy and high power density energy storage for portable electronics, electric vehicles and renewable sources of energy. This dissertation investigates sulfur based advanced electrode materials in Lithium/Sodium batteries. The electrochemical performances of the electrode materials have been enhanced due to their unique nano structures as well as the formation of novel composites. First, a nitrogen-doped graphene nanosheets/sulfur (NGNSs/S) composite was synthesized via a facile chemical reaction deposition. In this composite, NGNSs were employed as a conductive host to entrap S/polysulfides in the cathode part. The NGNSs/S composite delivered an initial discharge capacity of 856.7 mAh g-1 and a reversible capacity of 319.3 mAh g-1 at 0.1C with good recoverable rate capability. Second, NGNS/S nanocomposites, synthesized using chemical reaction-deposition method and low temperature heat treatment, were further studied as active cathode materials for room temperature Na-S batteries. Both high loading composite with 86% gamma-S8 and low loading composite with 25% gamma-S8 have been electrochemically evaluated and compared with both NGNS and S control electrodes. It was found that low loading NGNS/S composite exhibited better electrochemical performance with specific capacity of 110 and 48 mAh g-1 at 0.1C at the 1st and 300th cycle, respectively. The Coulombic efficiency of 100% was obtained at the 300th cycle. Third, high purity rock-salt (RS), zinc-blende (ZB) and wurtzite (WZ) MnS nanocrystals with different morphologies were successfully synthesized via a facile solvothermal method. RS-, ZB- and WZ-MnS electrodes showed the capacities of 232.5 mAh g-1, 287.9 mAh g-1 and 79.8 mAh g-1 at the 600th cycle, respectively. ZB-MnS displayed the best performance in terms of specific capacity and cyclability. Interestingly, MnS electrodes

  4. Advanced Rechargeable Lithium Sulfur Dioxide Cell

    Science.gov (United States)

    1991-11-01

    AD-A274 908IIIIlIIIE McDonald , P. Harris, F. Goebel, S. Hossi ierra, M. Guentert, C. Todino 7 ad r nse TECHNICAL PRODUCTS INCY DTIC ELECTE JAN26 1994...Pawcatuck, CT 06379 94-02298 1425 Best Available Copy I ADVANCED RECHARGEABLE LITHIUM SULFUR DIOXIDE CELL I R.C. McDonald , P. Harris, F. Goebel, S. Hossain...20 minutes. The electrochemical measurements were carried out using a I Starbuck 20-station cycler system which is connected to a computer to monitor

  5. Advanced Byproduct Recovery: Direct Catalytic Reduction of Sulfur Dioxide to Elemental Sulfur.

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-06-01

    More than 170 wet scrubber systems applied, to 72,000 MW of U.S., coal-fired, utility boilers are in operation or under construction. In these systems, the sulfur dioxide removed from the boiler flue gas is permanently bound to a sorbent material, such as lime or limestone. The sulfated sorbent must be disposed of as a waste product or, in some cases, sold as a byproduct (e.g. gypsum). Due to the abundance and low cost of naturally occurring gypsum, and the costs associated with producing an industrial quality product, less than 7% of these scrubbers are configured to produce usable gypsum (and only 1% of all units actually sell the byproduct). The disposal of solid waste from each of these scrubbers requires a landfill area of approximately 200 to 400 acres. In the U.S., a total of 19 million tons of disposable FGD byproduct are produced, transported and disposed of in landfills annually. The use of regenerable sorbent technologies has the potential to reduce or eliminate solid waste production, transportation and disposal. In a regenerable sorbent system, the sulfur dioxide in the boiler flue gas is removed by the sorbent in an adsorber. The S0{sub 2}s subsequently released, in higher concentration, in a regenerator. All regenerable systems produce an off-gas stream from the regenerator that must be processed further in order to obtain a salable byproduct, such as elemental sulfur, sulfuric acid or liquid S0{sub 2}.

  6. Capacity Fade Analysis of Sulfur Cathodes in Lithium–Sulfur Batteries

    Science.gov (United States)

    Yan, Jianhua; Liu, Xingbo

    2016-01-01

    Rechargeable lithium–sulfur (Li–S) batteries are receiving ever‐increasing attention due to their high theoretical energy density and inexpensive raw sulfur materials. However, their rapid capacity fade has been one of the key barriers for their further improvement. It is well accepted that the major degradation mechanisms of S‐cathodes include low electrical conductivity of S and sulfides, precipitation of nonconductive Li2S2 and Li2S, and poly‐shuttle effects. To determine these degradation factors, a comprehensive study of sulfur cathodes with different amounts of electrolytes is presented here. A survey of the fundamentals of Li–S chemistry with respect to capacity fade is first conducted; then, the parameters obtained through electrochemical performance and characterization are used to determine the key causes of capacity fade in Li–S batteries. It is confirmed that the formation and accumulation of nonconductive Li2S2/Li2S films on sulfur cathode surfaces are the major parameters contributing to the rapid capacity fade of Li–S batteries. PMID:27981001

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

    Science.gov (United States)

    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.

  8. Scrap tire pyrolysis using a new type two-stage pyrolyzer: Effects of dolomite and olivine on producing a low-sulfur pyrolysis oil

    International Nuclear Information System (INIS)

    Choi, Gyung-Goo; Oh, Seung-Jin; Kim, Joo-Sik

    2016-01-01

    Scrap tire pyrolysis was performed using a two-stage pyrolyzer consisting of an auger reactor and a fluidized bed reactor to produce a low-sulfur pyrolysis oil. In the experiments, the effect of the residence time of the feed material in the auger reactor was investigated at ∼300 (auger reactor) and 500 °C (fluidized bed reactor). In addition, natural dolomite and olivine and calcined dolomite and olivine were used as the fluidized bed materials to examine their effects on reducing the sulfur content of pyrolysis oil. In the experiments, the yields of the oil from the auger reactor were 1.4–3.7 wt%, and it was enriched with DL-limonene whose content in the oil was 40–50 wt%. The yields of the oil from the fluidized bed reactor were 42–46 wt%. The optimum residence time of the feed material in the auger reactor turned out to be 3.5 min. Calcined dolomite and olivine significantly decreased the sulfur content of pyrolysis oil. Metal oxides of the additives appeared to react with H_2S to form metal sulfides. The sulfur content of pyrolysis oil obtained with calcined olivine was 0.45 wt%. - Highlights: • Scrap tires were successfully pyrolyzed in a new type two-stage pyrolyzer. • The two-stage pyrolyzer is composed of an auger and fluidized bed reactors. • Calcination of olivine and dolomite led to a strong decrease in sulfur. • The lowest sulfur content of pyrolysis oil was 0.45 wt%. • Pyrolysis oil yields from the fluidized bed reactor were 43–46 wt%.

  9. Contribution to the study of sulfur trioxide formation and determination of the sulfuric acid dew point in boiler plants

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, H.

    1983-11-01

    This paper analyzes chemical reaction kinetics of the formation of sulfur trioxide and sulfuric acid in combustion air and flue gas of steam generators. Formulae for sulfuric acid equilibrium reactions according to Wahnschaffe (W. Grimm, 1972) and R. Hasse, H.W. Borgmann (1962) are presented. Theoretical acid dew point, combustion parameters with influence on the dew point temperature and formation of sulfates are further discussed. Sulfur trioxide formation at temperatures above 1,000 C as a non-equilibrium reaction is outlined as another variant of chemical reactions. A graphic evaluation is made of dew point conditions in brown coal dust fired, and heating oil fired steam generators. (11 refs.)

  10. Analysis of sulfur-iodine thermochemical cycle for solar hydrogen production. Part 1: decomposition of sulfuric acid

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Cunping; T-Raissi, Ali [Central Florida Univ., Florida Solar Energy Center, Cocoa, FL (United States)

    2005-05-01

    The sulfur-iodine (S-I) thermochemical water splitting cycle is one of the most studied cycles for hydrogen (H{sub 2}) production. S-I cycle consists of four sections: (I) acid production and separation and oxygen purification, (II) sulfuric acid concentration and decomposition, (III) hydroiodic acid (HI) concentration, and (IV) HI decomposition and H{sub 2} purification. Section II of the cycle is an endothermic reaction driven by the heat input from a high temperature source. Analysis of the S-I cycle in the past thirty years have been focused mostly on the utilization of nuclear power as the high temperature heat source for the sulfuric acid decomposition step. Thermodynamic as well as kinetic considerations indicate that both the extent and rate of sulfuric acid decomposition can be improved at very high temperatures (in excess of 1000 deg C) available only from solar concentrators. The beneficial effect of high temperature solar heat for decomposition of sulfuric acid in the S-I cycle is described in this paper. We used Aspen Technologies' HYSYS chemical process simulator (CPS) to develop flowsheets for sulfuric acid (H{sub 2}SO{sub 4}) decomposition that include all mass and heat balances. Based on the HYSYS analyses, two new process flowsheets were developed. These new sulfuric acid decomposition processes are simpler and more stable than previous processes and yield higher conversion efficiencies for the sulfuric acid decomposition and sulfur dioxide and oxygen formation. (Author)

  11. Recycling of water, carbon, and sulfur during subduction of serpentinites: A stable isotope study of Cerro del Almirez, Spain

    Science.gov (United States)

    Alt, Jeffrey C.; Garrido, Carlos J.; Shanks, Wayne C.; Turchyn, Alexandra; Padrón-Navarta, José Alberto; López Sánchez-Vizcaíno, Vicente; Gómez Pugnaire, María Teresa; Marchesi, Claudio

    2012-01-01

    We use the concentrations and isotope compositions of water, carbon, and sulfur in serpentinites and their dehydration products to trace the cycling of volatiles during subduction. Antigorite serpentinites from the Cerro del Almirez complex, Spain, contain 9–12 wt.% H2O and 910 ± 730 ppm sulfur, and have bulk δ18O values of 8.6 ± 0.4‰, δD = − 54 ± 5‰, and δ34S = 5.0‰, consistent with serpentinization at temperatures of ~ 200 °C by seawater hydrothermal fluids in a seafloor setting. The serpentinites were dehydrated to chlorite–harzburgite (olivine + orthopyroxene + chlorite) at 700 °C and 1.6–1.9 GPa during subduction metamorphism, resulting in loss of water, and sulfur. The chlorite–harzburgites contain 5.7 ± 1.9 wt.% H2O, and have bulk δ18O = 8.0 ± 0.9‰, and δD = − 77 ± 11‰. The rocks contain 650 ± 620 ppm sulfur having δ34S = 1.2‰. Dehydration of serpentinite resulted in loss of 5 wt.% H2O having δ18O = 8–10‰ and δD = − 27 to − 65‰, and loss of 260 ppm sulfur as sulfate, having δ34S = 14.5‰. The contents and δ13C of total carbon in the two rock types overlap, with a broad trend of decreasing carbon contents and δ13C from ~ 1300 to 200 ppm and − 9.6 to − 20.2‰. This reflects mixing between reduced carbon in the rocks (210 ppm, δ13C ≈ − 26‰) and seawater-derived carbonate (δ13C ≈ − 1‰). Our results indicate: 1) Serpentinized oceanic peridotites carry significant amounts of isotopically fractionated water, carbon and sulfur into subduction zones; 2) Subduction of serpentinites to high P and T results in loss of water, and sulfur, which can induce melting and contribute to 18O, D, and 34S enrichments and oxidation of the sub-arc mantle wedge; and 3) Isotopically fractionated water, carbon, and sulfur in serpentinite dehydration products are recycled deeper into the mantle where they can contribute to isotope heterogeneities and may be significant for volatile budgets of the deep Earth.

  12. A Foldable Lithium-Sulfur Battery.

    Science.gov (United States)

    Li, Lu; Wu, Zi Ping; Sun, Hao; Chen, Deming; Gao, Jian; Suresh, Shravan; Chow, Philippe; Singh, Chandra Veer; Koratkar, Nikhil

    2015-11-24

    The next generation of deformable and shape-conformable electronics devices will need to be powered by batteries that are not only flexible but also foldable. Here we report a foldable lithium-sulfur (Li-S) rechargeable battery, with the highest areal capacity (∼3 mAh cm(-2)) reported to date among all types of foldable energy-storage devices. The key to this result lies in the use of fully foldable and superelastic carbon nanotube current-collector films and impregnation of the active materials (S and Li) into the current-collectors in a checkerboard pattern, enabling the battery to be folded along two mutually orthogonal directions. The carbon nanotube films also serve as the sulfur entrapment layer in the Li-S battery. The foldable battery showed batteries with significantly greater energy density than traditional lithium-ion batteries could power the flexible and foldable devices of the future including laptops, cell phones, tablet computers, surgical tools, and implantable biomedical devices.

  13. Cell Concepts of Metal-Sulfur Batteries (Metal = Li, Na, K, Mg): Strategies for Using Sulfur in Energy Storage Applications.

    Science.gov (United States)

    Medenbach, Lukas; Adelhelm, Philipp

    2017-09-29

    There is great interest in using sulfur as active component in rechargeable batteries thanks to its low cost and high specific charge (1672 mAh/g). The electrochemistry of sulfur, however, is complex and cell concepts are required, which differ from conventional designs. This review summarizes different strategies for utilizing sulfur in rechargeable batteries among membrane concepts, polysulfide concepts, all-solid-state concepts as well as high-temperature systems. Among the more popular lithium-sulfur and sodium-sulfur batteries, we also comment on recent results on potassium-sulfur and magnesium-sulfur batteries. Moreover, specific properties related to the type of light metal are discussed.

  14. Co-combustion characteristics and blending optimization of tobacco stem and high-sulfur bituminous coal based on thermogravimetric and mass spectrometry analyses.

    Science.gov (United States)

    Zhang, Kaihua; Zhang, Kai; Cao, Yan; Pan, Wei-ping

    2013-03-01

    Despite much research on co-combustion of tobacco stem and high-sulfur coal, their blending optimization has not been effectively found. This study investigated the combustion profiles of tobacco stem, high-sulfur bituminous coal and their blends by thermogravimetric analysis. Ignition and burnout performances, heat release performances, and gaseous pollutant emissions were also studied by thermogravimetric and mass spectrometry analyses. The results indicated that combustion of tobacco stem was more complicated than that of high-sulfur bituminous coal, mainly shown as fixed carbon in it was divided into two portions with one early burning and the other delay burning. Ignition and burnout performances, heat release performances, and gaseous pollutant emissions of the blends present variable trends with the increase of tobacco stem content. Taking into account the above three factors, a blending ratio of 0–20% tobacco stem content is conservatively proposed as optimum amount for blending. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Extractive de-sulfurization and de-ashing of high sulfur coals by oxidation with ionic liquids

    International Nuclear Information System (INIS)

    Saikia, Binoy K.; Khound, Kakoli; Baruah, Bimala P.

    2014-01-01

    Highlights: • Extractive de-sulfurization and de-ashing process for cleaning high sulfur coals. • The process removes inorganic as well as organic sulfur components from high sulfur coals. • The process has less risk to chemists and other surroundings. - Abstract: The environmental consequences of energy production from coals are well known, and are driving the development of desulfurization technologies. In this investigation, ionic liquids were examined for extractive desulfurization and de-ashing in industrially important high sulfur sub-bituminous Indian coals. The ionic liquids, namely, 1-n-butyl-3-methylimidazolium tetrafluoroborate (IL1) and 1-n-butyl 3-methylimidazolium chloride (IL2) were employed for desulfurization of a few Indian coal samples in presence of HCOOH/H 2 O 2 and V 2 O 5 . Results show the maximum removal of 50.20% of the total sulfur, 48.00% of the organic sulfur, and 70.37 wt% of the ash in this process. The ionic liquids were recovered and subsequently used for further desulfurization. FT-IR spectra reveal the transformation of organic sulfur functionalities into the sulfoxides (S=O) and sulfones (-SO 2 ) due to the oxidative reactions. The sulfate, pyrite and sulfides (aryls) signals in the near edge X-ray absorption fine structure (NEXAFS) of the oxidized coal samples showed sulfur transformation during the desulfurization process. The study demonstrates the removal of significant amount of inorganic as well as organic sulfur (aryls) components from the original high sulfur coal samples to make them cleaner

  16. Integrated boiler, superheater, and decomposer for sulfuric acid decomposition

    Science.gov (United States)

    Moore, Robert [Edgewood, NM; Pickard, Paul S [Albuquerque, NM; Parma, Jr., Edward J.; Vernon, Milton E [Albuquerque, NM; Gelbard, Fred [Albuquerque, NM; Lenard, Roger X [Edgewood, NM

    2010-01-12

    A method and apparatus, constructed of ceramics and other corrosion resistant materials, for decomposing sulfuric acid into sulfur dioxide, oxygen and water using an integrated boiler, superheater, and decomposer unit comprising a bayonet-type, dual-tube, counter-flow heat exchanger with a catalytic insert and a central baffle to increase recuperation efficiency.

  17. Using lichens as physiological indicators of sulfurous pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Sundstroem, K R; Haellgren, J E

    1973-01-01

    Lichens are known to be extremely sensitive to sulfurous pollutants and have thus disappeared from the regions around urban areas. The authors give the physiological background to this sensitivity and an outline for a test system for sulfurous pollutants based on lichens.

  18. Sulfur in human nutrition - effects beyond protein synthesis

    NARCIS (Netherlands)

    Gertjan Schaafsma

    2008-01-01

    That sulfur is essential to humans is based on the requirement of S-animo acids for normal growth and maintenance of nitrogen balance and not on the optimization of metabolic proccesses involving the synthesis of non-protein sulphur containing compounds. This paper reviews the significance of sulfur

  19. Seed production and dispersal of sulfur cinquefoil in northeast Oregon

    Science.gov (United States)

    Kathleen A. Dwire; Catherine G. Parks; Michael L. McInnis; Bridgett J. Naylor

    2006-01-01

    Sulfur cinquefoil (family Rosaceae) is an invasive, herbaceous perennial, native to Eurasia. It has wide ecological amplitude and has become established throughout North America in numerous habitat types. Sulfur cinquefoil reproduces only by seed (achenes); however, little is known about its regenerative strategy or reproductive biology. To improve understanding of the...

  20. Sulfur K-edge absorption spectroscopy on selected biological systems

    International Nuclear Information System (INIS)

    Lichtenberg, Henning

    2008-07-01

    Sulfur is an essential element in organisms. In this thesis investigations of sulfur compounds in selected biological systems by XANES (X-ray Absorption Near Edge Structure) spectroscopy are reported. XANES spectroscopy at the sulfur K-edge provides an excellent tool to gain information about the local environments of sulfur atoms in intact biological samples - no extraction processes are required. Spatially resolved measurements using a Kirkpatrick-Baez mirror focusing system were carried out to investigate the infection of wheat leaves by rust fungi. The results give information about changes in the sulfur metabolism of the host induced by the parasite and about the extension of the infection into visibly uninfected plant tissue. Furthermore, XANES spectra of microbial mats from sulfidic caves were measured. These mats are dominated by microbial groups involved in cycling sulfur. Additionally, the influence of sulfate deprivation and H 2 S exposure on sulfur compounds in onion was investigated. To gain an insight into the thermal degradation of organic material the influence of roasting of sulfur compounds in coffee beans was studied. (orig.)

  1. Sulfur accumulation and atmospherically deposited sulfate in the Lake States.

    Science.gov (United States)

    Mark B. David; George Z. Gernter; David F. Grigal; Lewis F. Ohmann

    1989-01-01

    Characterizes the mass of soil sulfur (adjusted for nitrogen), and atmospherically deposited sulfate along an acid precipitation gradient from Minnesota to Michigan. The relationship of these variables, presented graphically through contour mapping, suggests that patterns of atmospheric wet sulfate deposition are reflected in soil sulfur pools.

  2. 40 CFR 52.724 - Control strategy: Sulfur dioxide.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control strategy: Sulfur dioxide. 52... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Illinois> § 52.724 Control strategy: Sulfur... Energy Incorporated. This disapproval does not in and of itself result in the growth restrictions of...

  3. Two-step rapid sulfur capture. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-04-01

    The primary goal of this program was to test the technical and economic feasibility of a novel dry sorbent injection process called the Two-Step Rapid Sulfur Capture process for several advanced coal utilization systems. The Two-Step Rapid Sulfur Capture process consists of limestone activation in a high temperature auxiliary burner for short times followed by sorbent quenching in a lower temperature sulfur containing coal combustion gas. The Two-Step Rapid Sulfur Capture process is based on the Non-Equilibrium Sulfur Capture process developed by the Energy Technology Office of Textron Defense Systems (ETO/TDS). Based on the Non-Equilibrium Sulfur Capture studies the range of conditions for optimum sorbent activation were thought to be: activation temperature > 2,200 K for activation times in the range of 10--30 ms. Therefore, the aim of the Two-Step process is to create a very active sorbent (under conditions similar to the bomb reactor) and complete the sulfur reaction under thermodynamically favorable conditions. A flow facility was designed and assembled to simulate the temperature, time, stoichiometry, and sulfur gas concentration prevalent in the advanced coal utilization systems such as gasifiers, fluidized bed combustors, mixed-metal oxide desulfurization systems, diesel engines, and gas turbines.

  4. Sulfur pollution: an environmental study of Welland, Ontario

    Science.gov (United States)

    Michael R. Moss

    1977-01-01

    The distribution of sulfur as an environmental pollutant is analysed in the vicinity of Welland, Ontario. A biogeochemical-cycle approach enables areas of excess accumulation to be compared among all linked ecosystem components. Although the patterns of distribution are similar, the amounts of sulfur accumulated in different ecosystems, grassland and woodland, show...

  5. 46 CFR 151.50-55 - Sulfur (molten).

    Science.gov (United States)

    2010-10-01

    ... BULK LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-55 Sulfur (molten). (a.... Heat transfer media shall be steam, and alternate media will require specific approval of the... 46 Shipping 5 2010-10-01 2010-10-01 false Sulfur (molten). 151.50-55 Section 151.50-55 Shipping...

  6. Nitrogen, carbon, and sulfur metabolism in natural Thioploca samples

    DEFF Research Database (Denmark)

    Otte, S.; Kuenen, JG; Nielsen, LP

    1999-01-01

    Filamentous sulfur bacteria of the genus Thioploca occur as dense mats on the continental shelf off the coast of Chile and Peru. Since little is known about their nitrogen, sulfur, and carbon metabolism, this study was undertaken to investigate their (eco)physiology. Thioploca is able to store...

  7. Structural change of the porous sulfur cathode using gelatin as a binder during discharge and charge

    International Nuclear Information System (INIS)

    Wang You; Huang Yaqin; Wang Weikun; Huang Chongjun; Yu Zhongbao; Zhang, Hao; Sun Jing; Wang Anbang; Yuan Keguo

    2009-01-01

    The structural change of the porous sulfur cathode using gelatin as a binder was studied by means of scanning electron microscopy (SEM) and X-ray diffractometry (XRD). The original sulfur cathode exhibited a homogenous distribution of sulfur, carbon and pores. During the discharge process, the pores and elemental sulfur disappeared gradually. However, those changes were reversed and elemental sulfur was reformed after the charge process, which improved the electrochemical performance of lithium-sulfur batteries.

  8. Chemical Immobilization Effect on Lithium Polysulfides for Lithium-Sulfur Batteries.

    Science.gov (United States)

    Li, Caixia; Xi, Zhucong; Guo, Dexiang; Chen, Xiangju; Yin, Longwei

    2018-01-01

    Despite great progress in lithium-sulfur batteries (LSBs), great obstacles still exist to achieve high loading content of sulfur and avoid the loss of active materials due to the dissolution of the intermediate polysulfide products in the electrolyte. Relationships between the intrinsic properties of nanostructured hosts and electrochemical performance of LSBs, especially, the chemical interaction effects on immobilizing polysulfides for LSB cathodes, are discussed in this Review. Moreover, the principle of rational microstructure design for LSB cathode materials with strong chemical interaction adsorbent effects on polysulfides, such as metallic compounds, metal particles, organic polymers, and heteroatom-doped carbon, is mainly described. According to the chemical immobilizing mechanism of polysulfide on LSB cathodes, three kinds of chemical immobilizing effects, including the strong chemical affinity between polar host and polar polysulfides, the chemical bonding effect between sulfur and the special function groups/atoms, and the catalytic effect on electrochemical reaction kinetics, are thoroughly reviewed. To improve the electrochemical performance and long cycling life-cycle stability of LSBs, possible solutions and strategies with respect to the rational design of the microstructure of LSB cathodes are comprehensively analyzed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. A Robust, Water-Based, Functional Binder Framework for High-Energy Lithium-Sulfur Batteries.

    Science.gov (United States)

    Lacey, Matthew J; Österlund, Viking; Bergfelt, Andreas; Jeschull, Fabian; Bowden, Tim; Brandell, Daniel

    2017-07-10

    We report here a water-based functional binder framework for the lithium-sulfur battery systems, based on the general combination of a polyether and an amide-containing polymer. These binders are applied to positive electrodes optimised towards high-energy electrochemical performance based only on commercially available materials. Electrodes with up to 4 mAh cm -2 capacity and 97-98 % coulombic efficiency are achievable in electrodes with a 65 % total sulfur content and a poly(ethylene oxide):poly(vinylpyrrolidone) (PEO:PVP) binder system. Exchange of either binder component for a different polymer with similar functionality preserves the high capacity and coulombic efficiency. The improvement in coulombic efficiency from the inclusion of the coordinating amide group was also observed in electrodes where pyrrolidone moieties were covalently grafted to the carbon black, indicating the role of this functionality in facilitating polysulfide adsorption to the electrode surface. The mechanical properties of the electrodes appear not to significantly influence sulfur utilisation or coulombic efficiency in the short term but rather determine retention of these properties over extended cycling. These results demonstrate the robustness of this very straightforward approach, as well as the considerable scope for designing binder materials with targeted properties. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Sulfur determination in concrete samples using laser-induced breakdown spectroscopy and limestone standards

    Science.gov (United States)

    Hrdlička, Aleš; Hegrová, Jitka; Novotný, Karel; Kanický, Viktor; Prochazka, David; Novotný, Jan; Modlitbová, Pavlína; Sládková, Lucia; Pořízka, Pavel; Kaiser, Jozef

    2018-04-01

    A LIBS equipment operating at 532 nm was optimized and used for sulfur determination in concrete samples. The influence of He atmosphere in a gas-tight chamber (1000-200 mbar) on S I 921.29 nm line sensitivity, signal-to-background and signal-to-noise ratio was studied at gate delays 100-2000 ns. Wide range of gate delays from 500 to about 1000 ns and pressures from several hundreds of mbar to the atmospheric pressure can be used for the desired detection of sulfur. The LIBS quantification was done using a simple calibration method. A synthetic limestone enriched by defined amounts of sodium sulfate was newly employed for direct quantification of S in concrete. This powder material was pressed into pellets and ablated with the LIBS system. The average content of sulfur as SO3 in the samples was 0.41-0.70 wt% by LIBS and 0.43-0.61 wt% by a reference standard procedure employing gravimetry and Inductively Coupled Plasma Triple Quad Mass Spectrometry (ICP-QQQMS). The uncertainty of the yielded LIBS results covers also the dispersion of the points in the calibration line and ranges from 16 to 28% at the probability level of 95%. The uncertainty of the ICP-QQQMS results was almost 10%. No correction on different signal response on the limestone and on the concrete was necessary.

  11. Preparation and characterization of silver loaded montmorillonite modified with sulfur amino acid

    Energy Technology Data Exchange (ETDEWEB)

    Li, Tian, E-mail: phdlitian@163.com; Lin, Oulian; Lu, Zhiyuan; He, Liuimei; Wang, Xiaosheng

    2014-06-01

    The Na{sup +} montmorillonite (MMT) was modified with sulfur containing amino acid (L-cystine, L-cysteine or L-methionine) and characterized by energy dispersive spectrometer (EDS), X-ray diffraction (XRD) and Fourier transform infrared spectrum (FT-IR). The results showed the modification was smooth and the surface condition of MMT was changed with sulfur containing groups. Then silver was loaded on the modified MMTs via ion-exchange reaction under microwave irradiation, the spectra of X-ray photoelectron spectroscopy (XPS), EDS and FT-IR confirmed the successful loading of massive silver and the strong interaction between sulfur and silver, the silver loaded L-cystine modified MMT (Ag@AA-MMT-3) with a silver content of 10.93 wt% was the highest of all. Further more, the Ag@AA-MMT-3 was under the irradiation of a UV lamp to turn silver ions to silver nano particles (Ag NPs). The XPS, specific surface area (SSA), transmission electron microscopy (TEM), XRD patterns and UV–vis spectra proved the existence of uniform nano scaled metallic Ag NPs. By contrast, the UV irradiated Ag@AA-MMT-3 (Ag@AA-MMT-UV) showed a much better slow release property than Ag@AA-MMT-3 or Ag@MMT. The Ag@AA-MMT-UV showing a large inhibition zone and high inhibition ratio presented very good antibacterial property.

  12. The corrosion behavior of molybdenum and Hastelloy B in sulfur and sodium polysulfides at 623 K

    International Nuclear Information System (INIS)

    Brown, A.P.

    1987-01-01

    An experimental study was completed to determine the corrosion behavior of molybdenum and Hastelloy B, a nickel-based alloy with high molybdenum content, in sulfur and sodium polysulfides (Na/sub 2/S/sub 3/,Na/sub 2/S/sub 4/, Na/sub 2/S/sub 5/) at 623 K. In sulfur, molybdenum corrodes very slowly, with a parabolic rate constant of 3.6 x 10/sup -9/ cm s/sup -1/2/. Hastelloy B shows no measurable corrosion after 100h of exposure to sulfur. The corrosion reaction of molybdenum in Na/sub 2/S/sub 3/ is characterized by the formation of a protective film that effectively eliminates further corrosion after the first 100h of exposure. Hastelloy B, however, corrodes rapidly in Na/sub 2/S/sub 3/, with corrosion rates approaching those of pure nickel under the same conditions. After the first 4h of exposure, the kinetics for the corrosion of Hastelloy B in Na/sub 2/S/sub 3/ follows a linear rate law. The scale morphology has multiple spalled layers of NiS/sub 2/, with some crystallites of NiS/sub 2/ appearing on the leading face of the scale and between the individual scale layers. This spalling causes smaller coupons of the Hastelloy B to corrode faster than larger coupons

  13. Sulfur dioxide emissions and market effects under the Clean Air Act Acid Rain Program

    International Nuclear Information System (INIS)

    Zipper, C.E.; Gilroy, L.

    1998-01-01

    The Clean Air Act Amendments of 1990 (CAAA90) established a national program to control sulfur dioxide (SO 2 ) emissions from electricity generation. CAAA90's market-based approach includes trading and banking of SO 2 -emissions allowances. The paper presents an analysis of data describing electric utility SO 2 emissions in 1995, the first year of the program's Phase I, and market effects over the 1990-95 period. Fuel switching and flue-gas desulfurization were the dominant means used in 1995 by targeted generators to reduce emissions to 51% of 1990 levels. Flue-gas desulfurization costs, emissions allowance prices, low-sulfur coal prices, and average sulfur contents of coals shipped to electric utilities declined over the 1990-95 period. Projections indicate that 13-15 million allowances will have been banked during the programs' Phase I, which ends in 1999, a quantity expected to last through the first decade of the program's stricter Phase II controls. In 1995, both allowance prices and SO 2 emissions were below pre-CAAA90 expectations. The reduction of SO 2 emissions beyond pre-CAAA90 expectations, combined with lower-than-expected allowance prices and declining compliance costs, can be viewed as a success for market-based environmental controls. 21 refs., 6 figs., 3 tabs

  14. Adsorption of sulfur dioxide on ammonia-treated activated carbon fibers

    Science.gov (United States)

    Mangun, C.L.; DeBarr, J.A.; Economy, J.

    2001-01-01

    A series of activated carbon fibers (ACFs) and ammonia-treated ACFs prepared from phenolic fiber precursors have been studied to elucidate the role of pore size, pore volume, and pore surface chemistry on adsorption of sulfur dioxide and its catalytic conversion to sulfuric acid. As expected, the incorporation of basic functional groups into the ACFs was shown as an effective method for increasing adsorption of sulfur dioxide. The adsorption capacity for dry SO2 did not follow specific trends; however the adsorption energies calculated from the DR equation were found to increase linearly with nitrogen content for each series of ACFs. Much higher adsorption capacities were achieved for SO2 in the presence of oxygen and water due to its catalytic conversion to H2SO4. The dominant factor for increasing adsorption of SO2 from simulated flue gas for each series of fibers studied was the weight percent of basic nitrogen groups present. In addition, the adsorption energies calculated for dry SO2 were shown to be linearly related to the adsorption capacity of H2SO4 from this flue gas for all fibers. It was shown that optimization of this parameter along with the pore volume results in higher adsorption capacities for removal of SO2 from flue gases. ?? 2001 Elsevier Science Ltd. All rights reserved.

  15. Sulfur Rich Coal Gasification and Low Impact Methanol Production

    Directory of Open Access Journals (Sweden)

    Andrea Bassani

    2018-03-01

    Full Text Available In recent times, the methanol was employed in numerous innovative applications and is a key compound widely used as a building block or intermediate for producing synthetic hydrocarbons, solvents, energy storage medium and fuel. It is a source of clean, sustainable energy that can be produced from traditional and renewable sources: natural gas, coal, biomass, landfill gas and power plant or industrial emissions. An innovative methanol production process from coal gasification is proposed in this work. A suitable comparison between the traditional coal to methanol process and the novel one is provided and deeply discussed. The most important features, with respect to the traditional ones, are the lower carbon dioxide emissions (about 0.3% and the higher methanol production (about 0.5% without any addition of primary sources. Moreover, it is demonstrated that a coal feed/fuel with a high sulfur content allows higher reductions of carbon dioxide emissions. The key idea is to convert hydrogen sulfide and carbon dioxide into syngas (a mixture of hydrogen and carbon monoxide by means of a regenerative thermal reactor. This is the Acid Gas to Syngas technology, a completely new and effective route of processing acid gases. The main concept is to feed an optimal ratio of hydrogen sulphide and carbon monoxide and to preheat the inlet acid gas before the combustion. The reactor is simulated using a detailed kinetic scheme.

  16. Isotope dilution ICP-MS with laser-assisted sample introduction for direct determination of sulfur in petroleum products

    Energy Technology Data Exchange (ETDEWEB)

    Boulyga, Sergei F.; Heilmann, Jens; Heumann, Klaus G. [Johannes Gutenberg-University Mainz (Germany). Institute of Inorganic Chemistry and Analytical Chemistry

    2005-08-01

    Inductively coupled plasma isotope dilution mass spectrometry (ICP-IDMS) with direct laser-assisted introduction of isotope-diluted samples into the plasma, using a laser ablation system with high ablation rates, was developed for accurate sulfur determinations in different petroleum products such as 'sulfur-free' premium gasoline, diesel fuel, and heating oil. Two certified gas oil reference materials were analyzed for method validation. Two different {sup 34}S-enriched spike compounds, namely, elementary sulfur dissolved in xylene and dibenzothiophene in hexane, were synthesized and tested for their usefulness in this isotope dilution technique. The isotope-diluted sample was adsorbed on a filter-paper-like material, which was fixed in a special holder for irradiation by the laser beam. Under these conditions no time-dependent spike/analyte fractionation was only observed for the dibenzothiophene spike during the laser ablation process, which means that the measured {sup 34}S/{sup 32}S isotope ratio of the isotope-diluted sample remained constant - a necessary precondition for accurate results with the isotope dilution technique. A comparison of LA-ICP-IDMS results with the certified values of the gas oil reference materials and with results obtained from ICP-IDMS analyses with wet sample digestion demonstrated the accuracy of the new LA-ICP-IDMS method in the concentration range of 9.2 {mu}g g{sup -1} ('sulfur-free' premium gasoline) to 10.4 mg g{sup -1} (gas oil reference material BCR 107). The detection limit for sulfur by LA-ICP-IDMS is 0.04 {mu}g g{sup -1} and the analysis time is only about 10 min, which therefore also qualifies this method for accurate determinations of low sulfur contents in petroleum products on a routine level. (orig.)

  17. Isotope dilution ICP-MS with laser-assisted sample introduction for direct determination of sulfur in petroleum products.

    Science.gov (United States)

    Boulyga, Sergei F; Heilmann, Jens; Heumann, Klaus G

    2005-08-01

    Inductively coupled plasma isotope dilution mass spectrometry (ICP-IDMS) with direct laser-assisted introduction of isotope-diluted samples into the plasma, using a laser ablation system with high ablation rates, was developed for accurate sulfur determinations in different petroleum products such as 'sulfur-free' premium gasoline, diesel fuel, and heating oil. Two certified gas oil reference materials were analyzed for method validation. Two different 34S-enriched spike compounds, namely, elementary sulfur dissolved in xylene and dibenzothiophene in hexane, were synthesized and tested for their usefulness in this isotope dilution technique. The isotope-diluted sample was adsorbed on a filter-paper-like material, which was fixed in a special holder for irradiation by the laser beam. Under these conditions no time-dependent spike/analyte fractionation was only observed for the dibenzothiophene spike during the laser ablation process, which means that the measured 34S/32S isotope ratio of the isotope-diluted sample remained constant-a necessary precondition for accurate results with the isotope dilution technique. A comparison of LA-ICP-IDMS results with the certified values of the gas oil reference materials and with results obtained from ICP-IDMS analyses with wet sample digestion demonstrated the accuracy of the new LA-ICP-IDMS method in the concentration range of 9.2 microg g(-1) ('sulfur-free' premium gasoline) to 10.4 mg g(-1) (gas oil reference material BCR 107). The detection limit for sulfur by LA-ICP-IDMS is 0.04 microg g(-1) and the analysis time is only about 10 min, which therefore also qualifies this method for accurate determinations of low sulfur contents in petroleum products on a routine level.

  18. Effects of sulfur nutrition on phytotoxicity and growth responses of bean plants to ozone

    Energy Technology Data Exchange (ETDEWEB)

    Adedipe, N O; Hofstra, G; Ormrod, D P

    1972-01-01

    Phaseolus vulgaris L. cv. Blue Lake plants were grown in sand culture at three temperatures, and fed with nutrient solution containing 1.3 or 32 mg/liter sulfur (S). Plants were fumigated twice with ozone at 50 parts per hundred million (pphm) for 2 h. Intensity of phytotoxicity was markedly lower in plants grown at the high S rate. Ozone reduced chlorophyll content of plants grown in low S at 25/20 and 30/25/sup 0/. With the high S treatment, however, ozone had no significant effect on chlorophyll content particularly at the lower temperatures. Irrespective of S nutrition, ozone had no effect on total soluble carbohydrate content. Ozone effects on plant growth depended on plant part, growth temperature, and S nutrition.

  19. Identification of major planktonic sulfur oxidizers in stratified freshwater lake.

    Directory of Open Access Journals (Sweden)

    Hisaya Kojima

    Full Text Available Planktonic sulfur oxidizers are important constituents of ecosystems in stratified water bodies, and contribute to sulfide detoxification. In contrast to marine environments, taxonomic identities of major planktonic sulfur oxidizers in freshwater lakes still remain largely unknown. Bacterioplankton community structure was analyzed in a stratified freshwater lake, Lake Mizugaki in Japan. In the clone libraries of 16S rRNA gene, clones very closely related to a sulfur oxidizer isolated from this lake, Sulfuritalea hydrogenivorans, were detected in deep anoxic water, and occupied up to 12.5% in each library of different water depth. Assemblages of planktonic sulfur oxidizers were specifically analyzed by constructing clone libraries of genes involved in sulfur oxidation, aprA, dsrA, soxB and sqr. In the libraries, clones related to betaproteobacteria were detected with high frequencies, including the close relatives of Sulfuritalea hydrogenivorans.

  20. Sulfur impacts on forest health in west-central Alberta

    International Nuclear Information System (INIS)

    Maynard, D.G.; Stadt, J.J.; Mallett, K.I.; Volney, W.J.A.

    1994-01-01

    A study was conducted to evaluate forest health and tree growth in relation to sulfur deposition in mature and immature lodgepole pine and mature trembling aspen. Soil samples were taken in forests near two sour gas processing plants in west-central Alberta. The soil sample sites were classified into high, medium and low deposition classes. The impact of sulfur deposition on soil and foliar chemistry, tree growth, and forest health was evaluated. The analysis of tree growth, using radial increments, revealed no impact associated with the sulfur deposition class. The only indicators of extensive sulfur impacts on major forest communities detected to date are elevated sulfur concentrations in the surface organic horizon and foliage, the proportion of healthy lodgepole pines, and a depression in the annual specific volume increment. No evidence of widespread forest decline has been found. 42 refs., 35 tabs., 29 figs

  1. Once-through hybrid sulfur process for nuclear hydrogen production

    International Nuclear Information System (INIS)

    Jeong, Y. H.

    2008-01-01

    Increasing concern about the global climate change spurs the development of low- or zero-carbon energy system. Nuclear hydrogen production by water electrolysis would be the one of the short-term solutions, but low efficiency and high production cost (high energy consumption) is the technical hurdle to be removed. In this paper the once-through sulfur process composed of the desulfurization and the water electrolysis systems is proposed. Electrode potential for the conventional water electrolysis (∼2.0 V) can be reduced significantly by the anode depolarization using sulfur dioxide: down to 0.6 V depending on the current density This depolarized electrolysis is the electrolysis step of the hybrid sulfur process originally proposed by the Westinghouse. However; recycling of sulfur dioxide requires a high temperature heat source and thus put another technical hurdle on the way to nuclear hydrogen production: the development of high temperature nuclear reactors and corresponding sulfuric acid decomposition system. By the once-through use of sulfur dioxide rather than the closed recycle, the hurdle can be removed. For the sulfur feed, the desulfurization system is integrated into the water electrolysis system. Fossil fuels include a few percent of sulfur by weight. During the refinement or energy conversion, most of the sulfur should be separated The separated sulfur can be fed to the water electrolysis system and the final product would be hydrogen and sulfuric acid, which is number one chemical in the world by volume. Lowered electrode potential and additional byproduct, the sulfuric acid, can provide economically affordable hydrogen. In this study, the once-through hybrid sulfur process for hydrogen production was proposed and the process was optimized considering energy consumption in electrolysis and sulfuric acid concentration. Economic feasibility of the proposed process was also discussed. Based on currently available experimental data for the electrode

  2. EFFECTS OF ALKALINE SANDY LOAM ON SULFURIC SOIL ACIDITY AND SULFIDIC SOIL OXIDATION

    Directory of Open Access Journals (Sweden)

    Patrick S. Michael

    2015-08-01

    Full Text Available  In poor soils, addition of alkaline sandy loam containing an adequate proportion of sand, silt and clay would add value by improving the texture, structure and organic matter (OM for general use of the soils. In acid sulfate soils (ASS, addition of alkaline sandy would improve the texture and leach out salts as well as add a sufficient proportion of OM for vegetation establishment. In this study, addition of alkaline sandy loam into sulfuric soil effectively increased the pH, lowered the redox and reduced the sulfate content, the magnitude of the effects dependent on moisture content. Addition of alkaline sandy loam in combination with OM was highly effective than the effects of the lone alkaline sandy loam. When alkaline sandy was added alone or in combination with OM into sulfidic soil, the effects on pH and the redox were similar as in the sulfuric soil but the effect on sulfate content was variable. The effects under aerobic conditions were higher than under anaerobic conditions. The findings of this study have important implications for the general management of ASS where lime availability is a concern and its application is limited.International Journal of Environment Volume-4, Issue-3, June-August 2015Page: 42-54

  3. Soil degradation by sulfuric acid disposition on uranium producing sites in south Bulgaria

    International Nuclear Information System (INIS)

    Atanasov, I.; Gribachev, P.

    1997-01-01

    This study assesses the damage of soils caused by spills of sulfuric acid solutions used for in situ leaching of uranium at eight uranium producing (by open-cast method) sites (total area of approximately 220 ha) in the region of Momino-Rakovski (South Bulgaria). The upper soil layer is cinnamonic pseudopodzolic ( or Eutric Planosols by FAO Legend, 1974). The results of the investigation show that the sulfuric acid spills caused strong acidification of upper (0-20 cm) and subsurface (20-60 cm) soil horizons which is expressed as decreasing of pH (H 2 O) to 2.9-3.5 and increasing of exchangeable H + and Al 3+ to 18 and 32% from CEC. Acid degradation of soils is combined with reducing of organic matter content. The average concentration of the total heavy metal content in the upper soil horizon (in ppm) is: Cd=1.5; Cu=30; Pb=25; Zn=40 and U=8. No significant differences were detected between the upper and subsurface soil layers . The heavy metal concentration did not exceed the Bulgarian standards for heavy metals and uranium content of soils. But the coarse texture of the top soil layers, the lack of carbonates, The low CEC and strong acidity determine a low buffering capacity of the investigated soils and this can be considered as hazardous for plants. This indicates that a future soil monitoring should be carried out in the region together with measures for neutralizing of soil acidity

  4. Hydrogen production by Chlamydomonas reinhardtii under light driven sulfur deprived condition

    Energy Technology Data Exchange (ETDEWEB)

    Vijayaraghavan, Krishnan; Karthik, Rajendran [Biotechnology Research Division, Department of Biotechnology, Prathyusha Institute of Technology and Management, Aranvoyalkuppam, Thiruvallur District 602025, Tamil Nadu (India); Kamala Nalini, S.P. [Department of Biotechnology, Vel Group of Educational Institutions, Avadi, Alamadhi Road, Chennai 600062, Tamil Nadu (India)

    2009-10-15

    This article explores the possibility of demonstrating sustainable photohydrogen production using Chlamydomonas reinhardtii when grown in sulfur deprived photoautotrophic condition. The hydrogen evolving capability of the algal species was monitored based on alternating light and dark period. Investigation was carried out during the day time in order to exploit the solar energy for meeting the demand of the light period. The results showed that when the reactor was operated at varying photoperiod namely 2, 3 and 4 h of alternating light and dark period, the gas generation was found to be 32 {+-} 4, 63 {+-} 7 and 52 {+-} 5 mL/h, while the corresponding hydrogen content was 47, 86 and 87% respectively. Functional components of hydrogen generation reaction centers were also analyzed, which showed that the PS(I) reaction centers were involved in hydrogen production pathway, as the light absorption by PS(I) was prerequisite for hydrogen generation under sulfur deprived photoautotrophic condition. The findings showed a higher gas yield and hydrogen content under dark period, whereas under light period the gas content was below detectable level for hydrogen due to the reversible hydrogenase reaction. (author)

  5. Comparative analyses of physiological responses of Cynodon dactylon accessions from Southwest China to sulfur dioxide toxicity.

    Science.gov (United States)

    Li, Xi; Wang, Ling; Li, Yiqiao; Sun, Lingxia; Cai, Shizhen; Huang, Zhuo

    2014-01-01

    Sulfur dioxide (SO2), a major air pollutant in developing countries, is highly toxic to plants. To achieve better air quality and landscape, planting appropriate grass species in severe SO2 polluted areas is very critical. Cynodon dactylon, a widely used warm season turfgrass species, has good SO2-tolerant ability. In this study, we selected 9 out of 38 C. dactylon accessions from Southwest China as representatives of high, intermediate SO2-tolerant and SO2-sensitive accessions to comparatively analyze their physiological differences in leaves under SO2 untreated and treated conditions. Our results revealed that SO2-tolerant C. dactylon accessions showed higher soluble sugar, proline, and chlorophyll a contents under both SO2 treated and untreated conditions; higher chlorophyll b and carotenoid under SO2 treated condition; lower reactive oxygen species (ROS) level, oxidative damages, and superoxide dismutase (SOD) activities under SO2 treated condition; and higher peroxidase (POD) activities under SO2 untreated condition. Further results indicated that SO2-tolerant C. dactylon accessions had higher sulfur contents under both SO2 treated and untreated conditions, consistent with higher SO activities under both SO2 treated and untreated conditions, and higher SiR activities under SO2 treated condition. Taken together, our results indicated that SO2 tolerance of C. dactylon might be largely related to soluble sugar, proline and chlorophyll a contents, and SO enzyme activity.

  6. Sulfur cathodes with hydrogen reduced titanium dioxide inverse opal structure.

    Science.gov (United States)

    Liang, Zheng; Zheng, Guangyuan; Li, Weiyang; Seh, Zhi Wei; Yao, Hongbin; Yan, Kai; Kong, Desheng; Cui, Yi

    2014-05-27

    Sulfur is a cathode material for lithium-ion batteries with a high specific capacity of 1675 mAh/g. The rapid capacity fading, however, presents a significant challenge for the practical application of sulfur cathodes. Two major approaches that have been developed to improve the sulfur cathode performance include (a) fabricating nanostructured conductive matrix to physically encapsulate sulfur and (b) engineering chemical modification to enhance binding with polysulfides and, thus, to reduce their dissolution. Here, we report a three-dimensional (3D) electrode structure to achieve both sulfur physical encapsulation and polysulfides binding simultaneously. The electrode is based on hydrogen reduced TiO2 with an inverse opal structure that is highly conductive and robust toward electrochemical cycling. The relatively enclosed 3D structure provides an ideal architecture for sulfur and polysulfides confinement. The openings at the top surface allow sulfur infusion into the inverse opal structure. In addition, chemical tuning of the TiO2 composition through hydrogen reduction was shown to enhance the specific capacity and cyclability of the cathode. With such TiO2 encapsulated sulfur structure, the sulfur cathode could deliver a high specific capacity of ∼1100 mAh/g in the beginning, with a reversible capacity of ∼890 mAh/g after 200 cycles of charge/discharge at a C/5 rate. The Coulombic efficiency was also maintained at around 99.5% during cycling. The results showed that inverse opal structure of hydrogen reduced TiO2 represents an effective strategy in improving lithium sulfur batteries performance.

  7. Amine reactivity with charged sulfuric acid clusters

    Directory of Open Access Journals (Sweden)

    B. R. Bzdek

    2011-08-01

    Full Text Available The distribution of charged species produced by electrospray of an ammonium sulfate solution in both positive and negative polarities is examined using Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS. Positively-charged ammonium bisulfate cluster composition differs significantly from negatively-charged cluster composition. For positively-charged clusters all sulfuric acid is neutralized to bisulfate, whereas for negatively-charged clusters the degree of sulfuric acid neutralization is cluster size-dependent. With increasing cluster size (and, therefore, a decreasing role of charge, both positively- and negatively-charged cluster compositions converge toward ammonium bisulfate. The reactivity of negatively-charged sulfuric acid-ammonia clusters with dimethylamine and ammonia is also investigated by FTICR-MS. Two series of negatively-charged clusters are investigated: [(HSO4(H2SO4x] and [(NH4x(HSO4x+1(H2SO43]. Dimethylamine substitution for ammonia in [(NH4 x(HSO4 x+1(H2SO43] clusters is nearly collision-limited, and subsequent addition of dimethylamine to neutralize H2SO4 to bisulfate is within one order of magnitude of the substitution rate. Dimethylamine addition to [(HSO4 (H2SO4 x] clusters is either not observed or very slow. The results of this study indicate that amine chemistry will be evident and important only in large ambient negative ions (>m/z 400, whereas amine chemistry may be evident in small ambient positive ions. Addition of ammonia to unneutralized clusters occurs at a rate that is ~2–3 orders of magnitude slower than incorporation of dimethylamine either by substitution or addition

  8. Biogeochemistry of the sulfur oxidizer Thiomicrospira thermophila

    Science.gov (United States)

    Houghton, J.; Fike, D. A.; Wills, E.; Foustoukos, D.

    2013-12-01

    Near-seafloor hydrothermal environments such as diffuse flow venting or subsurface mixing are characterized by rapidly changing conditions and steep chemical and thermal gradients. Microorganisms living in these environments can take advantage of these changes by switching among metabolic pathways rather than specializing. We present reaction stoichiometry and rates for T. thermophila grown in a closed system both at ambient and elevated pressure (50 bars) that demonstrate substantial metabolic flexibility, shifting between up to 5 different sulfur cycling reactions over a 24 hour period. Based on the stoichiometry between S2O3 consumed and SO4 produced, three reactions are sulfur oxidation and two are disproportionation, which has not previously been demonstrated for Thiomicrospira strains. Reactants include S2O3, elemental S (both polymeric S chains and S8 rings), HS-, and O2, while products include polymeric elemental S, SO4, HS-, and polysulfides. The presence of μmolal concentrations of HS- has been confirmed during the time series only when stoichiometry predicts disproportionation. Production of HS- in the presence of elemental S results in abiotic conversion to polysulfides, keeping the sulfide concentrations low in solution. The transition from oxidation to disproportionation appears to be triggered by a depletion in dissolved oxygen and the rate of reaction is a second order function of S2O3 and O2 concentrations. Growth was tested at conditions spanning their pH tolerance (5.0 - 8.0) using a citrate buffer (pH 5.0), unbuffered media (initial pH 7.0), and Tris buffer (pH 8.0). The highest rates are observed at pH 8.0 with rates decreasing as a function of pH. The lowest rate occurs at pH 5.0 and exhibits pseudo-first order behavior over a 24 hour period, likely due to a long lag and very slow growth. Repeat injections after the culture is acclimated to the experimental conditions result in very high pseudo-first order rates due to rapid consumption of

  9. Neoproterozoic sulfur-isotope variation in Australia

    International Nuclear Information System (INIS)

    Gorjan, P.; Walter, M.R.

    2000-01-01

    A number of stages are apparent in sulfur-isotope geochemistry throughout the Neoproterozoic. Prior to the Sturtian glaciation (840-700 Ma) δ 34 S sulfate varied little (19 to 17.5 per mil), and δ 34 S sulfide ranged from -20 to +23 per mil. In the Bitter Springs Formation δ 34 S sulfide is greater in the non-marine portion compared to the marine portion. This can be explained by a paucity of sulfate in the non-marine waters, and is consistent with mineralogical evidence (Southgate, 1991). In the Sturtian glacial sediments δ 34 S sulfide starts below 0 per mil and rises to >30 per mil at the top of the glacial sediments. After the Sturtian glaciation δ 34 S sulfide averages ∼30 per mil (and 34 per mil for δ 34 S organic ) for the extent of silt deposition. This increase in δ 34 S sulfide also appears in China, Canada and Namibia (Gorjan et al., 2000). δ 34 S sulfate also rises but is lower than the average δ 34 S sulfate (5 sulfate nodules in the Tapley Hill Formation average 26 per mil). However, the sulfate nodules may not be preserving the original seawater δ 34 S sulfate 34 S enrichment in sulfides usually occurs in freshwater or euxinic settings, but all evidence points to a sulfate-rich and non-euxinic environment in the Sturtian post-glacial deposits (linear %C vs. %S plots; high FeS 2 :FeS ratios; low degree of pyritisation; Gorjan et al. 2000, Gorjan, 1998). Such a situation points to sulfides being formed from extremely 34 S enriched sulfate (perhaps up to 45 per mil). This global rise in δ 34 S of both sulfur fractions in the Sturtian postglacial has led us to speculate that 34 S enriched sulfate was formed beneath a stagnant, ice-covered ocean, an environment postulated by Hoffman (1998), during the Sturtian glaciation and was brought to shallower waters in an ocean-upwelling event. Sulfide depleted in 34 S may have been deposited on abyssal plains. δ 34 S sulfide and δ 34 S sulfate falls sharply at the conclusion of siltstone deposition

  10. Monitoring of sulfur dioxide emission resulting from biogas utilization on commercial pig farms in Taiwan.

    Science.gov (United States)

    Su, Jung-Jeng; Chen, Yen-Jung

    2015-01-01

    The objective of this work tends to promote methane content in biogas and evaluate sulfur dioxide emission from direct biogas combustion without desulfurization. Analytical results of biogas combustion showed that combustion of un-desulfurized biogas exhausted more than 92% of SO₂ (P hydrogen sulfide was removed during the combustion process using un-desulfurized biogas (P hydrogen sulfide may deposit on the surfaces of power generator's engines or burner heads of boilers. Some of them (4.6-9.1% of H₂S) were converted to SO₂ in exhaust gas. Considering the impacts to human health and living environment, it is better to desulfurize biogas before any applications.

  11. Effect of commercial activated carbons in sulfur cathodes on the electrochemical properties of lithium/sulfur batteries

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jin-Woo; Kim, Icpyo [School of Materials Science and Engineering, Gyeongsang National University, 501 Jinju-daero, Jinju, Gyeongnam 52828 (Korea, Republic of); Kim, Ki-Won; Nam, Tae-Hyun; Cho, Kwon-Koo; Ahn, Jou-Hyeon [Department of Materials Engineering and Convergence Technology, Gyeongsang National University, 501 Jinju-daero, Jinju, Gyeongnam 52828 (Korea, Republic of); Ryu, Ho-Suk [Department of Material and Energy Engineering, Gyeongwoon University, 730, Gangdong-ro, Sandong-myeon, Gumi, Gyeongbuk, 39160 (Korea, Republic of); Ahn, Hyo-Jun, E-mail: ahj@gnu.ac.kr [School of Materials Science and Engineering, Gyeongsang National University, 501 Jinju-daero, Jinju, Gyeongnam 52828 (Korea, Republic of); Department of Materials Engineering and Convergence Technology, Gyeongsang National University, 501 Jinju-daero, Jinju, Gyeongnam 52828 (Korea, Republic of)

    2016-10-15

    Highlights: • The sulfur/activated carbon composite is fabricated using commercial activated carbons. • The sulfur/activated carbon composite with coal shows the best performance. • The Li/S battery has capacities of 1240 mAh g{sup −1} at 1 C and 567 mAh g{sup −1} at 10 C. - Abstract: We prepared sulfur/active carbon composites via a simple solution-based process using the following commercial activated carbon-based materials: coal, coconut shells, and sawdust. Although elemental sulfur was not detected in any of the sulfur/activated carbon composites based on Thermogravimetric analysis, X-ray diffraction, and Raman spectroscopy, Energy-dispersive X-ray spectroscopy results confirmed its presence in the activated carbon. These results indicate that sulfur was successfully impregnated in the activated carbon and that all of the activated carbons acted as sulfur reservoirs. The sulfur/activated carbon composite cathode using coal exhibited the highest discharge capacity and best rate capability. The first discharge capacity at 1 C (1.672 A g{sup −1}) was 1240 mAh g{sup −1}, and a large reversible capacity of 567 mAh g{sup −1} was observed at 10 C (16.72 A g{sup −1}).

  12. MATHEMATICAL SIMULATION OF THE INTERACTIONS AMONG CYANOBACTERIA, PURPLE SULFUR BACTERIA AND CHEMOTROPIC SULFUR BACTERIA IN MICROBIAL MAT COMMUNITIES

    NARCIS (Netherlands)

    DEWIT, R; VANDENENDE, FP; VANGEMERDEN, H

    A deterministic one-dimensional reaction diffusion model was constructed to simulate benthic stratification patterns and population dynamics of cyanobacteria, purple and colorless sulfur bacteria as found in marine microbial mats. The model involves the major biogeochemical processes of the sulfur

  13. Study on the technology of decreasing ash and sulfur in coking coal concentrate by deep-cleaning

    Energy Technology Data Exchange (ETDEWEB)

    Li, A.; Li, P.; Chen, S. [Hefei Design and Research Institute of Coal Industry, Hefei (China)

    2007-06-15

    Middling fractions of coking coal, a rare resource in China, were analysed for their embedded minerals both in kind and distribution. Observation with a microscope shows that most are clay minerals of very small particle size. The embedded minerals can be liberated from middling by grinding. Clean coal can be obtained from ground middling by the flocculation-flotation process. The yield of clean coal could thus be increased and its ash and sulfur content decreased. 3 refs., 2 figs., 4 tabs.

  14. The oxidation state of sulfur in apatite: A new oxybarometer?

    Science.gov (United States)

    Fiege, A.; Konecke, B.; Kim, Y.; Simon, A. C.; Becker, U.; Parat, F.

    2016-12-01

    Oxygen fugacity (fO2) of magmatic and hydrothermal systems influences, for instance, crystallization and degassing processes as well as metal solubilities in melts and fluids. Apatite is a ubiquitous mineral in magmatic and hydrothermal environments that can record and preserve volatile zonation. It can contain several thousand μg/g of the redox sensitive element sulfur (S), making S-in-apatite a potential fO2 sensor. Despite the polyvalent properties of S (e.g., S2-, S4+, S6+), the oxidation state and incorporation mechanisms of S in the apatite structure are poorly understood. In this study, the oxidation state of S-in-apatite as a function of fO2 is investigated using X-ray absorption near-edge structures (XANES) spectroscopy at the S K-edge. Apatites crystallized from lamproitic melts at 1000°C, 300 MPa and over a broad range of fO2 and sulfur fugacities (fS2) were measured. Peaks corresponding to S6+ ( 2482 eV), S4+ ( 2478 eV) and S2- ( 2470 eV) were identified in apatite. The integrated S6+/STotal (STotal = S6+ + S4+ + S2-) peak area ratios show a distinct positive correlation with fO2, increasing from 0.17 at FMQ+0 to 0.96 at FMQ+3. Ab-initio calculations were performed to further understand the energetics and geometry of incorporation of S6+, S4+ and S2- into the apatite (F-, Cl-, OH-) end-members. The results confirm that apatite can contain three different oxidations states of S (S6+, S4+, S2-) as a function of fO2. This makes apatite probably the first geologically relevant mineral to incorporate reduced (S2-), intermediate (S4+), and oxidized (S6+) S in variable proportions. We emphasize that the strong dependence of the S oxidation state in apatite as a function of fO2 is also coupled with changing S content of apatite and co-existing melt (i.e., with changing fS2), resulting in a complex correlation between [1] apatite-melt (or fluid) partitioning, [2] redox conditions and [3] the melt and/or fluid composition, making the application of previously

  15. Mechanisms and evolution of oxidative sulfur metabolism in green sulfur bacteria

    DEFF Research Database (Denmark)

    Gregersen, Lea Haarup; Bryant, Donald A.; Frigaard, Niels-Ulrik

    2011-01-01

    Green sulfur bacteria (GSB) constitute a closely related group of photoautotrophic and thiotrophic bacteria with limited phenotypic variation. They typically oxidize sulfide and thiosulfate to sulfate with sulfur globules as an intermediate. Based on genome sequence information from 15 strains...... product is further oxidized to sulfite by the dissimilatory sulfite reductase (DSR) system. This system consists of components horizontally acquired partly from sulfide-oxidizing and partly from sulfate-reducing bacteria. Depending on the strain, the sulfite is probably oxidized to sulfate by one of two...... in sulfate formation in other bacteria has been replaced by the DSR system in GSB. Sequence analyses suggested that the conserved soxJXYZAKBW gene cluster was horizontally acquired by Chlorobium phaeovibrioides DSM 265 from the Chlorobaculum lineage and that this acquisition was mediated by a mobile genetic...

  16. A sulfur host based on titanium monoxide@carbon hollow spheres for advanced lithium-sulfur batteries.

    Science.gov (United States)

    Li, Zhen; Zhang, Jintao; Guan, Buyuan; Wang, Da; Liu, Li-Min; Lou, Xiong Wen David

    2016-10-20

    Lithium-sulfur batteries show advantages for next-generation electrical energy storage due to their high energy density and cost effectiveness. Enhancing the conductivity of the sulfur cathode and moderating the dissolution of lithium polysulfides are two key factors for the success of lithium-sulfur batteries. Here we report a sulfur host that overcomes both obstacles at once. With inherent metallic conductivity and strong adsorption capability for lithium-polysulfides, titanium monoxide@carbon hollow nanospheres can not only generate sufficient electrical contact to the insulating sulfur for high capacity, but also effectively confine lithium-polysulfides for prolonged cycle life. Additionally, the designed composite cathode further maximizes the lithium-polysulfide restriction capability by using the polar shells to prevent their outward diffusion, which avoids the need for chemically bonding all lithium-polysulfides on the surfaces of polar particles.

  17. Degradation and dielectric properties of sulfur hexafluoride

    International Nuclear Information System (INIS)

    Fluck, Eric

    1985-01-01

    Sparking potential of sulfur hexafluoride is studied as a function of its decomposition by electrical discharges. The analysis of the gas is performed by mass spectrometry. The quantity of products resulting from spark discharges as a function of charge transported is plotted for SO_2F_2, SiF_4, SOF_4; it shows a linear increase with charge transported. Production rates of fluoride gases strongly increase with quantity of water vapor present at the beginning of the spark discharges. Decomposition of the gas, even at high levels (20%) does not exhibit measurable variations of sparking potential (at constant pressure). Production of SiF_4 by degradation of glass walls by hydrofluoric acid produced by discharges shows the important role played by this acid in the decomposition of the gas. It is necessary to use a gas containing water impurities at a level as small as possible. (author)

  18. Volatile Sulfur Compounds from Livestock Production

    DEFF Research Database (Denmark)

    Kasper, Pernille

    . Presently, the development of abatement technologies is limited by the lack of an accurate and reliable method for quantifying the effect on odor. To measure the impact of air cleaning techniques on perceived odor, common practice in Europe is to store odor samples in sample bags and quantify them......Volatile sulfur compounds, i.e. hydrogen sulfide, methanethiol and dimethyl sulfide have been identified as key odorants in livestock production due to their high concentration levels and low odor threshold values. At the same time their removal with abatement technologies based on mass transfer...... from a gas phase to a liquid phase, e.g. biotrickling filters, is decelerated due to their low partitioning coefficients. This can significantly limit the odor reduction obtained with these technologies. The present study examines the possibility of adding metal catalysts to enhance the mass transfer...

  19. Degradation of sulfur dioxide using plasma technology

    International Nuclear Information System (INIS)

    Estrada M, N.; Garcia E, R.; Pacheco P, M.; Valdivia B, R.; Pacheco S, J.

    2013-01-01

    This paper presents the electro-chemical study performed for sulfur dioxide (SO 2 ) treatment using non thermal plasma coupled to a nano structured fluid bed enhancing the toxic gas removal and the adsorption of acids formed during plasma treatment, more of 80% of removal was obtained. Non thermal plasma was ignited by dielectric barrier discharge (Dbd). The research was developed through an analysis of the chemical kinetics of the process and experimental study of degradation; in each experiment the electrical parameters and the influence of carbon nano structures were monitored to establish the optimal conditions of degradation. We compared the theoretical and experimental results to conclude whether the proposed model is correct for degradation. (Author)

  20. Graphene derived carbon confined sulfur cathodes for lithium-sulfur batteries: Electrochemical impedance studies

    International Nuclear Information System (INIS)

    Ganesan, Aswathi; Varzi, Alberto; Passerini, Stefano; Shaijumon, Manikoth M.

    2016-01-01

    Highlights: • Graphene-derived carbon (GDC) with distinctive porosity characteristics are prepared. • Effect of micro-/mesoporosity of GDC for improved Li-S battery performance is studied. • Impedance studies reveal insights into Li-S redox reactions and capacity fading phenomena. - Abstract: Sulfur nanocomposites are prepared by using graphene derived carbon (GDC), with controlled porosity characteristics, as confining matrix and are studied as efficient cathodes for lithium-sulfur (Li-S) batteries. To understand the effect of micro-/mesoporosity in porous carbon for the effective encapsulation of sulfur and polysulfides towards improved Li-S battery performance, two different GDC samples with controlled porosity characteristics, one with predominantly micropores (GDC-1) and a surface area of 1970 m 2 g −1 and the other with a surface area of 3239 m 2 g −1 , having more or less equal contribution of micro- and mesopores (GDC-2), are used to synthesize nanocomposite sulfur electrodes following melt diffusion process. Electrochemical studies are carried out by using cyclic voltammetry, galvanostatic charge/discharge cycling and electrochemical impedance spectroscopy (EIS). EIS spectra collected at different depth of discharge (DOD) in the first cycle as well as upon cycling give valuable insights into the Li-S redox reactions and capacity fading phenomena in these electrodes. The impedance response of GDC-S electrodes suggests a detrimental effect of the mesopores, where insoluble reaction products can easily accumulate, resulting in the loss of active material leading to capacity fading of Li-S cells.

  1. Nitrogen-doped graphene nanosheets/sulfur composite as lithium–sulfur batteries cathode

    Energy Technology Data Exchange (ETDEWEB)

    Hao, Yong [Department of Mechanical and Materials Engineering, Florida International University, 10555 W. Flagler Street, Miami, FL 33174 (United States); Li, Xifei; Sun, Xueliang [Nanomaterials and Energy Lab, Department of Mechanical and Materials Engineering, Western University, London, Ontario N6A 5B9 (Canada); Energy and Materials Engineering Centre, College of Physics and Materials Science, Tianjin Normal University, Tianjin 300387 (China); Wang, Chunlei, E-mail: wangc@fiu.edu [Department of Mechanical and Materials Engineering, Florida International University, 10555 W. Flagler Street, Miami, FL 33174 (United States)

    2016-11-15

    Highlights: • NGNSs are synthesized with amino-N and pyridine-N-oxide groups. • NGNSs provide a matrix with high surface area and conductivity. • N groups facilitate immobilization of polysulfides for Li–S batteries. - Abstract: Lithium–sulfur batteries have been receiving unprecedented attentions in recent years due to their exceptional high theoretical capacity and energy density, low cost and environmental friendliness. Yet their practical applications are still hindered by short cycle life, low efficiency and poor conductivity which are mainly caused by the insulating nature of sulfur and dissolution of polysulfides. Here, a nitrogen-doped graphene nanosheets/sulfur (NGNSs/S) composite was synthesized via a facile chemical reaction deposition. In this composite, NGNSs was employed as a conductive host to entrap S/polysulfides in the cathode part. The NGNSs/S composite delivered an initial discharge capacity of 856.7 mAh g{sup −1} and a reversible capacity of 319.3 mAh g{sup −1} at 0.1 C with good recoverable rate capability.

  2. Three-Dimensionally Hierarchical Graphene Based Aerogel Encapsulated Sulfur as Cathode for Lithium/Sulfur Batteries

    Directory of Open Access Journals (Sweden)

    Haipeng Li

    2018-01-01

    Full Text Available A simple and effective method was developed to obtain the electrode for lithium/sulfur (Li/S batteries with high specific capacity and cycling durability via adopting an interconnected sulfur/activated carbon/graphene (reduced graphene oxide aerogel (S/AC/GA cathode architecture. The AC/GA composite with a well-defined interconnected conductive network was prepared by a reduction-induced self-assembly process, which allows for obtaining compact and porous structures. During this process, reduced graphene oxide (RGO was formed, and due to the presence of oxygen-containing functional groups on its surface, it not only improves the electronic conductivity of the cathode but also effectively inhibits the polysulfides dissolution and shuttle. The introduced activated carbon allowed for lateral and vertical connection between individual graphene sheets, completing the formation of a stable three-dimensionally (3D interconnected graphene framework. Moreover, a high specific surface area and 3D interconnected porous structure efficiently hosts a higher amount of active sulfur material, about 65 wt %. The designed S/AC/GA composite electrodes deliver an initial capacity of 1159 mAh g−1 at 0.1 C and can retain a capacity of 765 mAh g−1 after 100 cycles in potential range from 1 V to 3 V.

  3. Three-Dimensionally Hierarchical Graphene Based Aerogel Encapsulated Sulfur as Cathode for Lithium/Sulfur Batteries

    Science.gov (United States)

    Li, Haipeng; Sun, Liancheng; Wang, Zhuo; Zhang, Yongguang; Tan, Taizhe; Wang, Gongkai

    2018-01-01

    A simple and effective method was developed to obtain the electrode for lithium/sulfur (Li/S) batteries with high specific capacity and cycling durability via adopting an interconnected sulfur/activated carbon/graphene (reduced graphene oxide) aerogel (S/AC/GA) cathode architecture. The AC/GA composite with a well-defined interconnected conductive network was prepared by a reduction-induced self-assembly process, which allows for obtaining compact and porous structures. During this process, reduced graphene oxide (RGO) was formed, and due to the presence of oxygen-containing functional groups on its surface, it not only improves the electronic conductivity of the cathode but also effectively inhibits the polysulfides dissolution and shuttle. The introduced activated carbon allowed for lateral and vertical connection between individual graphene sheets, completing the formation of a stable three-dimensionally (3D) interconnected graphene framework. Moreover, a high specific surface area and 3D interconnected porous structure efficiently hosts a higher amount of active sulfur material, about 65 wt %. The designed S/AC/GA composite electrodes deliver an initial capacity of 1159 mAh g−1 at 0.1 C and can retain a capacity of 765 mAh g−1 after 100 cycles in potential range from 1 V to 3 V. PMID:29373525

  4. Dissimilatory oxidation and reduction of elemental sulfur in thermophilic archaea.

    Science.gov (United States)

    Kletzin, Arnulf; Urich, Tim; Müller, Fabian; Bandeiras, Tiago M; Gomes, Cláudio M

    2004-02-01

    The oxidation and reduction of elemental sulfur and reduced inorganic sulfur species are some of the most important energy-yielding reactions for microorganisms living in volcanic hot springs, solfataras, and submarine hydrothermal vents, including both heterotrophic, mixotrophic, and chemolithoautotrophic, carbon dioxide-fixing species. Elemental sulfur is the electron donor in aerobic archaea like Acidianus and Sulfolobus. It is oxidized via sulfite and thiosulfate in a pathway involving both soluble and membrane-bound enzymes. This pathway was recently found to be coupled to the aerobic respiratory chain, eliciting a link between sulfur oxidation and oxygen reduction at the level of the respiratory heme copper oxidase. In contrast, elemental sulfur is the electron acceptor in a short electron transport chain consisting of a membrane-bound hydrogenase and a sulfur reductase in (facultatively) anaerobic chemolithotrophic archaea Acidianus and Pyrodictium species. It is also the electron acceptor in organoheterotrophic anaerobic species like Pyrococcus and Thermococcus, however, an electron transport chain has not been described as yet. The current knowledge on the composition and properties of the aerobic and anaerobic pathways of dissimilatory elemental sulfur metabolism in thermophilic archaea is summarized in this contribution.

  5. SULFUR ABUNDANCES IN THE ORION ASSOCIATION B STARS

    International Nuclear Information System (INIS)

    Daflon, Simone; Cunha, Katia; De la Reza, Ramiro; Holtzman, Jon; Chiappini, Cristina

    2009-01-01

    Sulfur abundances are derived for a sample of 10 B main-sequence star members of the Orion association. The analysis is based on LTE plane-parallel model atmospheres and non-LTE line formation theory by means of a self-consistent spectrum synthesis analysis of lines from two ionization states of sulfur, S II and S III. The observations are high-resolution spectra obtained with the ARCES spectrograph at the Apache Point Observatory. The abundance distribution obtained for the Orion targets is homogeneous within the expected errors in the analysis: A(S) = 7.15 ± 0.05. This average abundance result is in agreement with the recommended solar value (both from modeling of the photospheres in one-dimensional and three-dimensional, and meteorites) and indicates that little, if any, chemical evolution of sulfur has taken place in the last ∼4.5 billion years. The sulfur abundances of the young stars in Orion are found to agree well with results for the Orion Nebulae, and place strong constraints on the amount of sulfur depletion onto grains as being very modest or nonexistent. The sulfur abundances for Orion are consistent with other measurements at a similar galactocentric radius: combined with previous results for other OB-type stars produce a relatively shallow sulfur abundance gradient with a slope of -0.037 ± 0.012 dex kpc -1 .

  6. Evaluation of Thiobacillus Bacteria and Mycorrhizal Symbiosis on Yield and Yield Components of Garlic (Allium sativum at Different Levels of Sulfur

    Directory of Open Access Journals (Sweden)

    parvin Hejazi rad

    2017-09-01

    Full Text Available Introduction Most researchers believe that good management and proper use of biofertilizers are the ways for preparation of better nutritional conditions for the medicinal plant. Garlic is one of the most important medicinal crops. Allicin is the main active ingredient in this plant. Biofertilizers contain beneficial soil microorganisms or the metabolic products. Mycorrhizal symbiosis improves the soil physical, chemical and biological properties. Mycorrhizae increase crop resistance to pathogens, nutrient and water uptake, also reduce the negative effects of environmental stress and improve the quality of their host plants. Adding sulfur to the soil to improve the nutritional status of the plant by the release of nutrients will be effective when that the oxidation of sulfur in the soil is significant. For sulfur uptake by the plant, it is necessary that this element convert to sulfate by soil microorganisms. If elemental sulfur distribute in the soil and mix with the organic material, conversion of sulfur-oxidizing microorganisms be faster in wet conditions. Materials and methods The experiment was conducted as randomized complete block design with three replications in 2012. Treatments were included control plot, mycorrhizal inoculation (M, Thiobacillus (T, M + T, 75 kg sulfur per hectare (75S, 75S + M, 75S + T, 75S + M + T, 150 kg sulfur per hectare (150S, 150S + M, 150S + T, 150S + M + T. Each plot consisted of four rows with a spacing of 40 cm and row length of 10 m. In treatments with 75 and 150 kg sulfur per hectare, 48 and 96 g of sulfur were used, respectively. Thiobacillus at the recommended dose was added to the soil a week before planting. Percent of fungal colonization obtained with Gridline Intersect Method. HPLC method was used to extract allicin content. Data were analyzed with the MSTAT-C software; the means were compared with LSD test at the 5% level of probability. Results and discussion The results showed that tuber dry

  7. [Extraction and content determination of polysaccharides in Viscum coloratum].

    Science.gov (United States)

    Wang, Jun; Zhu, Yi-fan

    2007-11-01

    To establish a method for extraction and content determination of polysaccharide in Viscum coloratum. Polysaccharide was extracted by hot water, separated by ultrafiltration and ion-exchange chromatography. The content determination was performed at wavelength 490 nm with phenol-sulfuric acid as a chtomo-genic agent. The content of polyaccharide in V. coloratum, CVPS-III, and CVPS-III-C were respectively 4.93% (RSD 1.04%, n = 3), 43.28% (RSD 1.39%, n =3), 69.55% (RSD 1.62%, n = 3), and the average recovery was 96.07% (RSD 2.54%, n = 5). The method was simple, rapid, and accurate.

  8. Sulfur degassing due to contact metamorphism during flood basalt eruptions

    Science.gov (United States)

    Yallup, Christine; Edmonds, Marie; Turchyn, Alexandra V.

    2013-11-01

    We present a study aimed at quantifying the potential for generating sulfur-rich gas emissions from the devolatilization of sediments accompanying sill emplacement during flood basalt eruptions. The potential contribution of sulfur-rich gases from sediments might augment substantially the magma-derived sulfur gases and hence impact regional and global climate. We demonstrate, from a detailed outcrop-scale study, that sulfur and total organic carbon have been devolatilized from shales immediately surrounding a 3-m thick dolerite sill on the Isle of Skye, Scotland. Localized partial melting occurred within a few centimetres of the contact in the shale, generating melt-filled cracks. Pyrite decomposed on heating within 80 cm of the contact, generating sulfur-rich gases (a mixture of H2S and SO2) and pyrrhotite. The pyrrhotite shows 32S enrichment, due to loss of 34S-enriched SO2. Further decomposition and oxidation of pyrrhotite resulted in hematite and/or magnetite within a few cm of the contact. Iron sulfates were produced during retrogressive cooling and oxidation within 20 cm of the contact. Decarbonation of the sediments due to heating is also observed, particularly along the upper contact of the sill, where increasing δ13C is consistent with loss of methane gas. The geochemical and mineralogical features observed in the shales are consistent with a short-lived intrusion, emplaced in desulfurization, as well as decarbonation, of shales adjacent to an igneous intrusion. The liberated fluids, rich in sulfur and carbon, are likely to be focused along regions of low pore fluid pressure along the margins of the sill. The sulfur gases liberated from the sediments would have augmented the sulfur dioxide (and hydrogen sulfide) yield of the eruption substantially, had they reached the surface. This enhancement of the magmatic sulfur budget has important implications for the climate impact of large flood basalt eruptions that erupt through thick, volatile-rich sedimentary

  9. Experimental and numerical modeling of sulfur plugging in carbonate reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Abou-Kassem, J.H. [Chemical and Petroleum Engineering Department, UAE University, PO Box 17555, Al-Ain (United Arab Emirates)

    2000-05-01

    Sour gas, mainly in the form of hydrogen sulfide, is produced in large amounts from many oil and gas reservoirs in the United Arab Emirates. In addition to creating problems in production lines, the precipitation of elemental sulfur in vicinity of the wellbore is often reported to cause wellbore damage. While there have been several studies performed on the role of solid deposition in gas reservoirs, the role of sulfur deposition in oil reservoirs has not been investigated. This paper presents experimental results along with a comprehensive wellbore model that predicts sulfur precipitation as well as plugging. Two separate sets of experiments, one for a gas phase system and another for a crude oil system, were conducted to investigate the deposition of elemental sulfur in (linear) carbonate cores. The gas flow tests were conducted with elemental sulfur being carried with nitrogen through limestone cores. Changes in gas flow rate were monitored while the injection pressure was held constant. A series of experiments generated valuable data for plugging with elemental sulfur. X-ray diffraction tests provided evidence of sulfur deposition along the cores. The oil flow tests were carried out to observe sulfur precipitation and plugging in a carbonate core. The crude oil was de-asphalted before conducting these tests in order to isolate the effect of asphaltene plugging. Significant plugging was observed and was found to be dependent on flow rate and initial sulfur concentration. This information was used in a phenomenological model that was incorporated in the wellbore numerical model. The data for the numerical model were obtained from both test tube and oil flow experiments. By using a phenomenological model, the wellbore plugging was modeled with an excellent match (with experimental results)

  10. The performance of oil-fired boilers: The influence of fuel sulfur on emissions and appliance integrity

    International Nuclear Information System (INIS)

    Lee, S.W.

    1997-01-01

    ASHRAE research project RP-757 examined the impact of distillate fuel sulfur content on the energy and emission performance of oil-fired boilers. The project involved construction of a combustion test rig housed in a constant-temperature test room; installation of a 102.5 kW (350,000 Btu/h) capacity, steel hot water boiler equipped with a special test section to simulate boiler heat exchanger surfaces; introduction of continuous emission analyzers and data-acquisition/control systems; and preparation of specific test fuel oils in the 0.01% to 1.2% sulfur range. The combustion experiments provided comprehensive data including flue gas composition, total deposit weight on test heat exchanger surfaces, pH, sulfite and sulfate in the flue gas condensate and soluble deposits, and iron and sulfur in soluble and insoluble deposits. Controlled combustion experiments using the experimental boiler and fuels have provided the following observations for a systematic increase of boiler fuel sulfur: the flue gas SO 2 increased linearly; the acidity and concentrations of sulfite and sulfate in flue gas condensate and the soluble deposits increased; total surface deposits, which are made up of the soluble and insoluble portions, increased linearly; higher amounts of soluble iron sulfates formed with apparent increased corrosion potential of metal surfaces; and the boiler efficiency remained unchanged during the short-term combustion experiments

  11. Non-mass-dependent fractionation of sulfur and oxygen isotopes during UV photolysis of sulfur dioxide

    Science.gov (United States)

    Pen, Aranh

    Since the discovery of anomalous sulfur isotope abundance in the geological record in sulfate and sulfide minerals (Farquhar et al., 2000), much effort has been put into understanding their origin to provide new insights into the environmental conditions on the early Earth (Farquhar et al., 2001; Pavlov and Kasting, 2002; Ono et al., 2003; Zahnle et al., 2006; Farquhar et al., 2007; Lyons, 2007; Lyons, 2008). This discovery gained immense interest because of its implications for both the lack of oxygen in the atmosphere during the Archean era 2.5-3.8 Gya (billion years ago), and for rise of oxygen, or the "Great Oxidation Event", that occurred 2.2-2.4 Gya (Holland, 2002). These signatures are believed to be produced in an anticorrelation to oxygen abundance in the early atmosphere, which will aid in quantifying the rate of oxygenation during the "Great Oxidation Event". According to Farquhar et al. (2000), the non-mass-dependent (NMD), or anomalous, fractionation signatures were produced by photochemical reactions of volcanic sulfur species in Earth's early atmosphere (> 2.3 Gya) due to the lack of an oxygen and ozone shield, resulting in an atmosphere transparent to solar ultraviolet (UV) radiation (Farquhar et al., 2001). Interpretation of the anomalous rock records, though, depends on the identification of (1) chemical reactions that can produce the NMD signature (Farquhar and Wing, 2003); and (2) conditions necessary for conversion of the gas-phase products into solid minerals (Pavlov and Kasting, 2002). The focus of my research addresses the first step, which is to determine whether the chemical reactions that occurred in Earth's early atmosphere, resulting in NMD fractionation of sulfur isotopes, were due to broadband UV photochemistry, and to test isotopic self-shielding as the possible underlying mechanism. In this project, our goals were to test isotopic self-shielding during UV photolysis as a possible underlying mechanism for anomalous sulfur isotopic

  12. Terpolymerization of ethylene, sulfur dioxide and carbon monoxide

    Science.gov (United States)

    Johnson, R.; Steinberg, M.

    This invention relates to high molecular weight terpolymer of ethylene, sulfur dioxide and carbon monoxide stable to 280/sup 0/C and containing as little as 36 mo1% ethylene and about 41 to 51 mo1% sulfur dioxide, and to the method of producing said terpolymer by irradiation of a liquid and gaseous mixture of ethylene, sulfur dioxide and carbon monoxide by means of Co-60 gamma rays or an electron beam, at a temperature of about 10 to 50/sup 0/C, and at a pressure of about 140 to 680 atmospheres, to initiate polymerization.

  13. Biological activity of soils strongly polluted with sulfur

    Energy Technology Data Exchange (ETDEWEB)

    Krol, M; Maliszewska, W; Siuta, J

    1972-01-01

    Studies were carried out on soils strongly polluted with sulfur and acidified (to pH 1.4). The soils were subjected to an intensive liming. In field and pot experiments, the authors determined: the total quantity of bacteria, actinomycetes, fungi, azotobacter, nitrifiers, proteolytic activity of microorganisms, activity of ammonifiers and the number of sulfur-oxidizing and sulfate-reducing bacteria. It was found that intensive liming of sulfur-affected soils restored their biological activity. 8 references, 5 figures, 1 table.

  14. Morphological study of silver corrosion in highly aggressive sulfur environments

    DEFF Research Database (Denmark)

    Minzari, Daniel; Jellesen, Morten Stendahl; Møller, Per

    2011-01-01

    A silicone coated power module, having silver conducting lines, showed severe corrosion, after prolonged use as part of an electronic device in a pig farm environment, where sulfur containing corrosive gasses are known to exist in high amounts. Permeation of sulfur gasses and humidity through...... the silicone coating to the interface has resulted in three corrosion types namely: uniform corrosion, conductive anodic filament type of Ag2S growth, and silver migration with subsequent formation of sulfur compounds. Detailed morphological investigation of new and corroded power modules was carried out...

  15. Native sulfur/chlorine SAD phasing for serial femtosecond crystallography

    International Nuclear Information System (INIS)

    Nakane, Takanori; Song, Changyong; Suzuki, Mamoru; Nango, Eriko; Kobayashi, Jun; Masuda, Tetsuya; Inoue, Shigeyuki; Mizohata, Eiichi; Nakatsu, Toru; Tanaka, Tomoyuki; Tanaka, Rie; Shimamura, Tatsuro; Tono, Kensuke; Joti, Yasumasa; Kameshima, Takashi; Hatsui, Takaki; Yabashi, Makina; Nureki, Osamu; Iwata, So; Sugahara, Michihiro

    2015-01-01

    Sulfur SAD phasing facilitates the structure determination of diverse native proteins using femtosecond X-rays from free-electron lasers via serial femtosecond crystallography. Serial femtosecond crystallography (SFX) allows structures to be determined with minimal radiation damage. However, phasing native crystals in SFX is not very common. Here, the structure determination of native lysozyme from single-wavelength anomalous diffraction (SAD) by utilizing the anomalous signal of sulfur and chlorine at a wavelength of 1.77 Å is successfully demonstrated. This sulfur SAD method can be applied to a wide range of proteins, which will improve the determination of native crystal structures

  16. Mechanism of the toxic action of sulfur dioxide on plants

    Energy Technology Data Exchange (ETDEWEB)

    Nikolaevskii, V S; Miroshnikova, A T; Firger, V V; Belokrylova, L M

    1975-01-01

    Experiments were performed to determine the effects of sulfur dioxide on U CO2 metabolism and photosynthesis in fescue and timothy grass and in maple and barberry branches. The free radical inhibitors, ascorbic acid and thiourea, were found to decrease the damaging effects of the sulfur dioxide. These results indicated that the processes involved are of the free-radical chain type. Even at low sulfur dioxide concentrations, photosphosphorylation and carbon dioxide assimilation were inhibited. In addition, starch and protein as well as the formation of polymeric substances were also inhibited.

  17. Sulfur and Hydrogen Isotope Anomalies in Meteorite Sulfonic Acids

    Science.gov (United States)

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

    1997-01-01

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

  18. Volcanic sulfur degassing and the role of sulfides in controlling volcanic metal emissions

    Science.gov (United States)

    Edmonds, M.; Liu, E.

    2017-12-01

    Volcanoes emit prodigious quantities of sulfur and metals, their behaviour inextricably linked through pre-eruptive sulfide systematics and through degassing and speciation in the volcanic plume. Fundamental differences exist in the metal output of ocean island versus arc volcanoes, with volcanoes in Hawaii and Iceland outgassing large fluxes of gaseous and particulate chalcophiles; and arc volcanoes' plumes, in contrast, enriched in Zn, Cu, Tl and Pb. Metals and metalloids partition into a magmatic vapor phase from silicate melt at crustal pressures. Their abundance in magmatic vapor is influenced strongly by sulfide saturation and by the composition of the magmatic vapor phase, particularly with respect to chloride. These factors are highly dependent on tectonic setting. Metal outgassing is controlled by magma water content and redox: deep saturation in vapor and minimal sulfide in arc basalts yields metal-rich vapor; shallow degassing and resorption of sulfides feeds the metal content of volcanic gas in ocean islands. We present a detailed study of the sulfide systematics of the products of the 2014-2015 Holuhraun basaltic fissure eruption (Bárðarbunga volcanic system, Iceland) to illustrate the interplay between late water and sulfur outgassing; sulfide saturation and breakdown; and metal partitioning into a vapor phase. Sulfide globules, representing quenched droplets of an immiscible sulfide liquid, are preserved within erupted tephra. Sulfide globules in rapidly quenched tephra are preserved within both matrix glass and as inclusions in crystals. The stereologically-corrected 3D size distribution of sulfide globules ranges from importance in supplying sulfur and metals to the atmosphere during eruption.

  19. Quadruple sulfur isotope constraints on the origin and cycling of volatile organic sulfur compounds in a stratified sulfidic lake

    Science.gov (United States)

    Oduro, Harry; Kamyshny, Alexey; Zerkle, Aubrey L.; Li, Yue; Farquhar, James

    2013-11-01

    We have quantified the major forms of volatile organic sulfur compounds (VOSCs) distributed in the water column of stratified freshwater Fayetteville Green Lake (FGL), to evaluate the biogeochemical pathways involved in their production. The lake's anoxic deep waters contain high concentrations of sulfate (12-16 mmol L-1) and sulfide (0.12 μmol L-1 to 1.5 mmol L-1) with relatively low VOSC concentrations, ranging from 0.1 nmol L-1 to 2.8 μmol L-1. Sulfur isotope measurements of combined volatile organic sulfur compounds demonstrate that VOSC species are formed primarily from reduced sulfur (H2S/HS-) and zero-valent sulfur (ZVS), with little input from sulfate. Thedata support a role of a combination of biological and abiotic processes in formation of carbon-sulfur bonds between reactive sulfur species and methyl groups of lignin components. These processes are responsible for very fast turnover of VOSC species, maintaining their low levels in FGL. No dimethylsulfoniopropionate (DMSP) was detected by Electrospray Ionization Mass Spectrometry (ESI-MS) in the lake water column or in planktonic extracts. These observations indicate a pathway distinct from oceanic and coastal marine environments, where dimethylsulfide (DMS) and other VOSC species are principally produced via the breakdown of DMSP by plankton species.

  20. High Mass-Loading of Sulfur-Based Cathode Composites and Polysulfides Stabilization for Rechargeable Lithium/Sulfur Batteries

    International Nuclear Information System (INIS)

    Hara, Toru; Konarov, Aishuak; Mentbayeva, Almagul; Kurmanbayeva, Indira; Bakenov, Zhumabay

    2015-01-01

    Although sulfur has a high theoretical gravimetric capacity, 1672 mAh/g, its insulating nature requires a large amount of conducting additives: this tends to result in a low mass-loading of active material (sulfur), and thereby, a lower capacity than expected. Therefore, an optimal choice of conducting agents and of the method for sulfur/conducting-agent integration is critically important. In this paper, we report that the areal capacity of 4.9 mAh/cm 2 was achieved at sulfur mass loading of 4.1 mg/cm 2 by casting sulfur/polyacrylonitrile/ketjenblack (S/PAN/KB) cathode composite into carbon fiber paper. This is the highest value among published/reported ones even though it does not contain expensive nanosized carbon materials such as carbon nanotubes, graphene, or graphene derivatives, and competitive enough with the conventional LiCoO 2 -based cathodes (e.g., LiCoO 2 , <20 mg/cm 2 corresponding to <2.8 mAh/cm 2 ). Furthermore, the combination of sulfur/PAN-based composite and PAN-based carbon fiber paper enabled the sulfur-based composite to be used even in carbonate-based electrolyte solution that many lithium/sulfur battery researchers avoid the use of it because of severer irreversible active material loss than in electrolyte solutions without carbonate-based solutions, and even at the highest mass-loading ever reported (the more sulfur is loaded, the more decomposed sulfides deposit at an anode surface).

  1. 40 CFR 80.200 - What gasoline is subject to the sulfur standards and requirements?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false What gasoline is subject to the sulfur... (CONTINUED) AIR PROGRAMS (CONTINUED) REGULATION OF FUELS AND FUEL ADDITIVES Gasoline Sulfur Gasoline Sulfur Standards § 80.200 What gasoline is subject to the sulfur standards and requirements? For the purpose of...

  2. Bioleaching of metals from soils or sediments using the microbial sulfur cycle

    NARCIS (Netherlands)

    Tichy, R.

    1998-01-01

    Reduced inorganic sulfur species like elemental sulfur or sulfide are sensitive to changes in oxidative environments. Generally, inorganic reduced sulfur exists in natural environments in a solid phase, whereas its oxidation leads to sulfur solubilization and a production of acidity. This

  3. Multiphysics Modelling of Sodium Sulfur Battery

    Science.gov (United States)

    Mason, Jerry Hunter

    Due to global climate change and the desire to decrease greenhouse gas emissions, large scale energy storage has become a critical issue. Renewable energy sources such as wind and solar will not be a viable energy source unless the storage problem is solved. One of the practical and cost effective solutions for this problem is sodium sulfur batteries. These batteries are comprised of liquid electrode materials suspended in porous media and operate at relatively high temperatures (>300°C). The sodium anode and the sulfur/sodium-polysulfide cathode are separated by a solid electrolyte made of beta-alumina or NASICON material. Due to the use of porous materials in the electrodes, capillary pressure and the combination of capillary action and gravity become important. Capillary pressure has a strong dependence on the wetting phase (liquid electrode material) saturation; therefore sharp concentration gradients can occur between the inert gas and the electrode liquid, especially within the cathode. These concentration gradients can have direct impacts on the electrodynamics of the battery as they may produce areas of high electrical potential variation, which can decrease efficiency and even cause failures. Then, thermal management also becomes vital since the electrochemistry and material properties are sensitive to temperature gradients. To investigate these phenomena in detail and to attempt to improve upon battery design a multi-dimensional, multi-phase code has been developed and validated in this study. Then a porous media flow model is implemented. Transport equations for charge, mass and heat are solved in a time marching fashion using finite volume method. Material properties are calculated and updated as a function of time. The porous media model is coupled with the continuity equation and a separate diffusion equation for the liquid sodium in the melt. The total mass transport model is coupled with charge transport via Faraday's law. Results show that

  4. Sulfur-free lignins from alkaline pulping tested in mortar for use as mortar additives.

    Science.gov (United States)

    Nadif, A; Hunkeler, D; Käuper, P

    2002-08-01

    Sulfur-free lignin, obtained through the acid precipitation of black liquor from the soda pulping process, has been tested as water reducer in mortar. It has also been compared to existing commercial additives such as naphthalene sulfonates and lignosulfonates. The ash content and sugar content of these lignins are low in comparison to lignosulfonates, conferring on them higher purity. A procedure for small scale testing derived from the industrial norms SN-EN196 and ASTM (Designation C230-90) is presented. Specifically, all the sulfur-free lignins tested improved the flow of the mortar. Selected flax lignins performed better than lignosulfonates though still less than naphthalene sulfonates. Furthermore, certain hemp lignins gave comparable results to the lignosulfonates. Overall, the straw lignin prepared herein is comparable in performance to commercially available lignins, such as Organocell, Alcell and Curan 100. The plant from which the lignin was isolated, and the process of the pulp mill are the primary influences on the performance of the lignin.

  5. Induction of ovoviviparity in Rhabditis by sulfur dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Walker, J T; Tsui, R K

    1968-01-01

    While investigating the influence of atmospheric pollutants on soil and plant microbiotas, ovoviviparity was observed in the saprophagous nematode, Rhabditis sp., after exposure to various concentrations of sulfur dioxide.

  6. Preliminary study of varietal susceptibility to sulfur dioxide

    International Nuclear Information System (INIS)

    Miller, J.E.; Xerikos, P.B.

    1976-01-01

    The injury response of plants to air pollutants, such as sulfur dioxide, is known to vary in severity and type for different varieties or cultivars of a species. Differences in the susceptibility of soybean varieties to sulfur dioxide have previously been noted, but sufficient information is not available concerning the sulfur dioxide resistance of varieties commonly grown in the Midwest. Results are reported from preliminary experiments concerning acute sulfur dioxide effects on 12 soybean varieties. The injury symptoms ranged from cream colored necrotic lesions (generally on younger leaves) to a reddish brown necrotic stipling (on older leaves). Differences in the severity of symptom development for the varieties was evident on both the younger and older leaves. No injury was apparent with three of the varieties

  7. Nanomaterials: Science and applications in the lithium–sulfur battery

    KAUST Repository

    Ma, Lin; Hendrickson, Kenville E.; Wei, Shuya; Archer, Lynden A.

    2015-01-01

    of electricity from intermittent sources. Among the various electrochemical energy storage options under consideration, rechargeable lithium-sulfur (Li-S) batteries remain the most promising platform for reversibly storing large amounts of electrical energy

  8. Anode Improvement in Rechargeable Lithium-Sulfur Batteries.

    Science.gov (United States)

    Tao, Tao; Lu, Shengguo; Fan, Ye; Lei, Weiwei; Huang, Shaoming; Chen, Ying

    2017-12-01

    Owing to their theoretical energy density of 2600 Wh kg -1 , lithium-sulfur batteries represent a promising future energy storage device to power electric vehicles. However, the practical applications of lithium-sulfur batteries suffer from poor cycle life and low Coulombic efficiency, which is attributed, in part, to the polysulfide shuttle and Li dendrite formation. Suppressing Li dendrite growth, blocking the unfavorable reaction between soluble polysulfides and Li, and improving the safety of Li-S batteries have become very important for the development of high-performance lithium sulfur batteries. A comprehensive review of various strategies is presented for enhancing the stability of the anode of lithium sulfur batteries, including inserting an interlayer, modifying the separator and electrolytes, employing artificial protection layers, and alternative anodes to replace the Li metal anode. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. New treating processes for sulfur-containing natural gases

    Energy Technology Data Exchange (ETDEWEB)

    Kislenko, N.; Aphanasiev, A.; Nabokov, S.; Ismailova, H. [VNIIGAS, Moscow (Russian Federation)

    1996-12-31

    The traditional method of removing H{sub 2}S from sour natural gases is first to treat the gas with a solvent and then to recover the H{sub 2}S from the sour stream in a Claus plant. This method recovers up to 97% of the sulfur when a three-stage Claus unit is employed. Amine/Claus units have operating difficulties for small sulfur capacities (up to 5 tons/day) because the operation of the fired equipment (reaction furnace) is much more difficult. Therefore, for small scale sulfur recovery plants redox processes which exhibit a significant reduction in investment and operating costs are normally used. Many different factors influence the choice of gas desulfurization technology--composition and gas flow, environmental sulfur recovery requirements and CO{sub 2}/H{sub 2}S ratio.

  10. Sulfur transformations related to revegetation of flue gas desulfurization sludge disposal sites

    Energy Technology Data Exchange (ETDEWEB)

    Barlas, S.A.; Artiola, J.F.; Salo, L.F.; Goodrich-Mahoney, J.W. [University of Arizona, Tucson, AZ (United States). Dept. of Soil, Water and Environmental Sciences

    1999-10-01

    This study investigated factors controlling redox conditions in flue gas desulfurization (FGD) sludge and identified ways to minimize the production of phytotoxic reduced sulfur species at FGD sludge disposal sites. The oxidation of reduced FGD sludge (Eh-385 mV) appears to be a two-step process mostly controlled by water content. Eighty percent of total sulfide in reduced sludge was oxidized within 20 h of exposure to air with constant water evaporation. When organic carbon (OC) was added to saturated oxidized sludge, the Eh dropped exponentially. Sulfate reduction began at an Eh of about -75 mV and reached a maximum at -265 to -320 mV. Water content, degree of mixing, concentration of OC, and temperature control the rate and extent of reduction of FGD sludge. This suggests that water saturation and OC inputs to revegetated disposal sites should be controlled, especially during warm temperatures, to prevent production of phytotoxic levels of sulfides.

  11. Selective catalytic reduction of sulfur dioxide to elemental sulfur. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Liu, W.; Flytzani-Stephanopoulos, M.; Sarofim, A.F.

    1995-06-01

    This project has investigated new metal oxide catalysts for the single stage selective reduction of SO{sub 2} to elemental sulfur by a reductant, such as CO. Significant progress in catalyst development has been made during the course of the project. We have found that fluorite oxides, CeO{sub 2} and ZrO{sub 2}, and rare earth zirconates such as Gd{sub 2}Zr{sub 2}O{sub 7} are active and stable catalysts for reduction Of SO{sub 2} by CO. More than 95% sulfur yield was achieved at reaction temperatures about 450{degrees}C or higher with the feed gas of stoichiometric composition. Reaction of SO{sub 2} and CO over these catalysts demonstrated a strong correlation of catalytic activity with the catalyst oxygen mobility. Furthermore, the catalytic activity and resistance to H{sub 2}O and CO{sub 2} poisoning of these catalysts were significantly enhanced by adding small amounts of transition metals, such as Co, Ni, Co, etc. The resulting transition metal-fluorite oxide composite catalyst has superior activity and stability, and shows promise in long use for the development of a greatly simplified single-step sulfur recovery process to treat variable and dilute SO{sub 2} concentration gas streams. Among various active composite catalyst systems the Cu-CeO{sub 2} system has been extensively studied. XRD, XPS, and STEM analyses of the used Cu-CeO{sub 2} catalyst found that the fluorite crystal structure of ceria was stable at the present reaction conditions, small amounts of copper was dispersed and stabilized on the ceria matrix, and excess copper oxide particles formed copper sulfide crystals of little contribution to catalytic activity. A working catalyst consisted of partially sulfated cerium oxide surface and partially sulfided copper clusters. The overall reaction kinetics were approximately represented by a first order equation.

  12. Native sulfur/chlorine SAD phasing for serial femtosecond crystallography.

    Science.gov (United States)

    Nakane, Takanori; Song, Changyong; Suzuki, Mamoru; Nango, Eriko; Kobayashi, Jun; Masuda, Tetsuya; Inoue, Shigeyuki; Mizohata, Eiichi; Nakatsu, Toru; Tanaka, Tomoyuki; Tanaka, Rie; Shimamura, Tatsuro; Tono, Kensuke; Joti, Yasumasa; Kameshima, Takashi; Hatsui, Takaki; Yabashi, Makina; Nureki, Osamu; Iwata, So; Sugahara, Michihiro

    2015-12-01

    Serial femtosecond crystallography (SFX) allows structures to be determined with minimal radiation damage. However, phasing native crystals in SFX is not very common. Here, the structure determination of native lysozyme from single-wavelength anomalous diffraction (SAD) by utilizing the anomalous signal of sulfur and chlorine at a wavelength of 1.77 Å is successfully demonstrated. This sulfur SAD method can be applied to a wide range of proteins, which will improve the determination of native crystal structures.

  13. Tillandsia recurvata L. as a bioindicator of sulfur atmospheric pollution

    OpenAIRE

    Graciano, Corina; Fernández, L V; Caldiz, D O

    2003-01-01

    Tillandsia recurvata L. is an epiphyte that absorbs nutrients from the air, so it could be used as a bioindicator of atmospheric sulfur pollution. In order to test this idea, Tillandsia recurvata samples were seasonally collected for two years at three sites of La Plata, Buenos Aires Province, Argentina, in a suburban park and in a rural area 60 km away from the city. Macro- and microscopic observations were carried out and chlorophyll and sulfur concentrations of the tissue were measured to ...

  14. Atomic charges of sulfur in ionic liquids: experiments and calculations.

    Science.gov (United States)

    Fogarty, Richard M; Rowe, Rebecca; Matthews, Richard P; Clough, Matthew T; Ashworth, Claire R; Brandt, Agnieszka; Corbett, Paul J; Palgrave, Robert G; Smith, Emily F; Bourne, Richard A; Chamberlain, Thomas W; Thompson, Paul B J; Hunt, Patricia A; Lovelock, Kevin R J

    2017-12-14

    Experimental near edge X-ray absorption fine structure (NEXAFS) spectra, X-ray photoelectron (XP) spectra and Auger electron spectra are reported for sulfur in ionic liquids (ILs) with a range of chemical structures. These values provide experimental measures of the atomic charge in each IL and enable the evaluation of the suitability of NEXAFS spectroscopy and XPS for probing the relative atomic charge of sulfur. In addition, we use Auger electron spectroscopy to show that when XPS binding energies differ by less than 0.5 eV, conclusions on atomic charge should be treated with caution. Our experimental data provides a benchmark for calculations of the atomic charge of sulfur obtained using different methods. Atomic charges were computed for lone ions and ion pairs, both in the gas phase (GP) and in a solvation model (SMD), with a wide range of ion pair conformers considered. Three methods were used to compute the atomic charges: charges from the electrostatic potential using a grid based method (ChelpG), natural bond orbital (NBO) population analysis and Bader's atoms in molecules (AIM) approach. By comparing the experimental and calculated measures of the atomic charge of sulfur, we provide an order for the sulfur atoms, ranging from the most negative to the most positive atomic charge. Furthermore, we show that both ChelpG and NBO are reasonable methods for calculating the atomic charge of sulfur in ILs, based on the agreement with both the XPS and NEXAFS spectroscopy results. However, the atomic charges of sulfur derived from ChelpG are found to display significant, non-physical conformational dependence. Only small differences in individual atomic charge of sulfur were observed between lone ion (GP) and ion pair IL(SMD) model systems, indicating that ion-ion interactions do not strongly influence individual atomic charges.

  15. Health Endpoint Attributed to Sulfur Dioxide Air Pollutants

    Directory of Open Access Journals (Sweden)

    Geravandi

    2015-07-01

    Full Text Available Background Sulfur dioxide is a colorless gas, released from burning of coal, high-sulfur coal,s and diesel fuel. Sulfur dioxide harms human health by reacting with the moisture in the nose, nasal cavity and throat and this is the way by which it destroys the nerves in the respiratory system. Objectives The aim of this study was to focus on identifying the effects associated with sulfur dioxide on health in Ahvaz, Iran. Materials and Methods Data collections were performed by Ahvaz meteorological organization and the department of environment. Sampling was performed for 24 hours in four stations. Methods of sampling and analysis were according to US environmental protection agency (EPA guideline. Afterwards, we processed the raw data including instruction set correction of averaging, coding and filtering by Excel software and then, the impact of meteorological parameters were converted as the input file to the AirQ model. Finally, we calculated the health effects of exposure to sulfur dioxide. Results According to the findings, the concentration of sulfur dioxide in Ahvaz had an annual average of 51 μg/m3. Sum of the numbers of hospital admissions for respiratory diseases attributed to sulfur dioxide was 25 cases in 2012. Approximately, 5% of the total hospital admissions for respiratory disease and respiratory mortality happened when sulfur dioxide concentration was more than 10 mg/m3. Conclusions According to the results of this study, this increase could be due to higher fuel consumption, usage of gasoline in vehicles, oil industry, and steel and heavy industries in Ahwaz. The risk of mortality and morbidity were detected at the current concentrations of air pollutants.

  16. Sulfur mineralization of different plant materials labelled with 35 S

    International Nuclear Information System (INIS)

    Abreu Junior, Cassio H.

    1993-01-01

    This study was carried out, in green house conditions, with the objective of evaluating the effect of incorporation in soil of different plant materials labelled with 35 S and of incubation periods on the availability of sulfur to the bean test plants and on the dynamic of this element in the soil. The bean test plants dry matter yield ranged from 2.00 to 3.79 g/plant, the S content and absorption ranged from 118.20 to 194.04 mg/100 g and 2.61 to 6.34 mg/plant respectively. The 35 S derived from the incorporated bean plant material contributed with 12 to 256% of total S absorbed by bean test plant; rice plant material contributed with 12 to 22%; soybean plant material contributed 11 to 18%; corn plant material at rate of 7 g with, 11 to 19% and corn at rate of 3.5 g; with 7 to 1%. Plant material incorporation showed 35 S using efficiency by bean test plant of 21.41 to 9.94% by incorporated rice plant material, of 16.12 to 7.79% by rice material, of 13.11 to 6.49% by soybean material, of 10.24 to 6.21% by corn at rate of 3.5 g and of 7.41 to 3.81% by corn at rate of 7 g.Incorporated plant material with C/S relationship near 120, such as bean and rice, promoted desirable and favorable alteration in soil, while materials with C/S higher than 250, such as soybean and corn, led to unsatisfactory and undesirable alteration. The characteristic of incorporated plant materials which more affected its behavior was the C/S relationship, which depended on its physiological stage on collect timing. (author)

  17. Effects of sulfur dioxide on conifers

    Energy Technology Data Exchange (ETDEWEB)

    Govi, G.; Tagliani, F.; Cimino, A.

    1974-01-01

    Trials on the resistance of several conifer and oak species to the effects of sulfur dioxide at different concentrations and moisture levels were conducted. 72 combinations were experimented. The damages began to appear under the following conditions: Abies alba: 0.3 ppm, 25/sup 0/C, 70% ur after 24 hours; Picea excelsa: 0.3 ppm, 15/sup 0/C, 70-95% ur after 24 hours; Cedrus deodara: 0.3 ppm, 15/sup 0/C, 95% ur after 48 hours; Pinus pinea: 0.3 ppm, 15/sup 0/C, 70-95% after 72 hours; Pinus strobus 0.3 ppm, 25/sup 0/C, 70-95%, after 48 hours; Pinus pinaster: similar to the former; Pinus nigra: 2 ppm, 25/sup 0/C, 70-95%, ur after 5 days; Cupressus arizonica and C. semperivirens: 2 ppm, 25%/sup 0/C, 90% ur after 72 hours; Quercus robur: 5 ppm, 25/sup 0/C, 90% ur, after 10 days. 6 references, 3 figures, 1 table.

  18. Gasoline from natural gas by sulfur processing

    Energy Technology Data Exchange (ETDEWEB)

    Erekson, E.J.; Miao, F.Q. [Institute of Gas Technology, Des Plaines, IL (United States)

    1995-12-31

    The overall objective of this research project is to develop a catalytic process to convert natural gas to liquid transportation fuels. The process, called the HSM (Hydrogen Sulfide-Methane) Process, consists of two steps that each utilize a catalyst and sulfur-containing intermediates: (1) converting natural gas to CS{sub 2} and (2) converting CS{sub 2} to gasoline range liquids. Catalysts have been found that convert methane to carbon disulfide in yields up to 98%. This exceeds the target of 40% yields for the first step. The best rate for CS{sub 2} formation was 132 g CS{sub 2}/kg-cat-h. The best rate for hydrogen production is 220 L H{sub 2} /kg-cat-h. A preliminary economic study shows that in a refinery application hydrogen made by the HSM technology would cost $0.25-R1.00/1000 SCF. Experimental data will be generated to facilitate evaluation of the overall commercial viability of the process.

  19. Recent advances in lithium-sulfur batteries

    Science.gov (United States)

    Chen, Lin; Shaw, Leon L.

    2014-12-01

    Lithium-sulfur (Li-S) batteries have attracted much attention lately because they have very high theoretical specific energy (2500 Wh kg-1), five times higher than that of the commercial LiCoO2/graphite batteries. As a result, they are strong contenders for next-generation energy storage in the areas of portable electronics, electric vehicles, and storage systems for renewable energy such as wind power and solar energy. However, poor cycling life and low capacity retention are main factors limiting their commercialization. To date, a large number of electrode and electrolyte materials to address these challenges have been investigated. In this review, we present the latest fundamental studies and technological development of various nanostructured cathode materials for Li-S batteries, including their preparation approaches, structure, morphology and battery performance. Furthermore, the development of other significant components of Li-S batteries including anodes, electrolytes, additives, binders and separators are also highlighted. Not only does the intention of our review article comprise the summary of recent advances in Li-S cells, but also we cover some of our proposals for engineering of Li-S cell configurations. These systematic discussion and proposed directions can enlighten ideas and offer avenues in the rational design of durable and high performance Li-S batteries in the near future.

  20. Sensing Free Sulfur Dioxide in Wine

    Science.gov (United States)

    Monro, Tanya M.; Moore, Rachel L.; Nguyen, Mai-Chi; Ebendorff-Heidepriem, Heike; Skouroumounis, George K.; Elsey, Gordon M.; Taylor, Dennis K.

    2012-01-01

    Sulfur dioxide (SO2) is important in the winemaking process as it aids in preventing microbial growth and the oxidation of wine. These processes and others consume the SO2 over time, resulting in wines with little SO2 protection. Furthermore, SO2 and sulfiting agents are known to be allergens to many individuals and for that reason their levels need to be monitored and regulated in final wine products. Many of the current techniques for monitoring SO2 in wine require the SO2 to be separated from the wine prior to analysis. This investigation demonstrates a technique capable of measuring free sulfite concentrations in low volume liquid samples in white wine. This approach adapts a known colorimetric reaction to a suspended core optical fiber sensing platform, and exploits the interaction between guided light located within the fiber voids and a mixture of the wine sample and a colorimetric analyte. We have shown that this technique enables measurements to be made without dilution of the wine samples, thus paving the way towards real time in situ wine monitoring. PMID:23112627