WorldWideScience

Sample records for hybrid sulfur cycle

  1. 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...

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

    Energy Technology Data Exchange (ETDEWEB)

    Gorensek, M.

    2011-07-06

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

  3. Integration of photovoltaic and concentrated solar thermal technologies for H2 production by the hybrid sulfur cycle

    Science.gov (United States)

    Liberatore, Raffaele; Ferrara, Mariarosaria; Lanchi, Michela; Turchetti, Luca

    2017-06-01

    It is widely agreed that hydrogen used as energy carrier and/or storage media may significantly contribute in the reduction of emissions, especially if produced by renewable energy sources. The Hybrid Sulfur (HyS) cycle is considered as one of the most promising processes to produce hydrogen through the water-splitting process. The FP7 project SOL2HY2 (Solar to Hydrogen Hybrid Cycles) investigates innovative material and process solutions for the use of solar heat and power in the HyS process. A significant part of the SOL2HY2 project is devoted to the analysis and optimization of the integration of the solar and chemical (hydrogen production) plants. In this context, this work investigates the possibility to integrate different solar technologies, namely photovoltaic, solar central receiver and solar troughs, to optimize their use in the HyS cycle for a green hydrogen production, both in the open and closed process configurations. The analysis carried out accounts for different combinations of geographical location and plant sizing criteria. The use of a sulfur burner, which can serve both as thermal backup and SO2 source for the open cycle, is also considered.

  4. 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...

  5. 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

  6. 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

  7. Hybrid polyacrylamide/carbon coating on sulfur cathode for advanced lithium sulfur battery

    International Nuclear Information System (INIS)

    Li, Tao; Yuan, Yan; Hong, Bo; Cao, Huawei; Zhang, Kai; Lai, Yanqing; Liu, Yexiang; Huang, Zixin

    2017-01-01

    Commercialized conductive slurry consisting of polyacrylamide (PAM) and two kinds of carbon black was coated on the surface of sulfur cathode. The hybrid PAM/C coating not only physically blocks but also chemically anchors polysulfides within the cathode, confining their out-diffusion and shuttle. Besides, the flexible and highly-conductive coating layer buffers volume change of the cathode during discharge-charge process and reduces charge transfer resistance. A specific capacity of as high as ∼900 mAh g −1 after 300 cycles is demonstrated for the PAM/C coated cathode, which is a significant improvement of reversible capacity and cycle capability compared to uncoated or conventional PVDF/C coated cathode.

  8. 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.

  9. 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.

  10. Facile synthesis of graphene oxide @ mesoporous carbon hybrid nanocomposites for lithium sulfur battery

    International Nuclear Information System (INIS)

    Bao, Weizhai; Zhang, Zhian; Chen, Wei; Zhou, Chengkun; Lai, Yanqing; Li, Jie

    2014-01-01

    Graphical abstract: - Highlights: • A novel design and synthesis of GO@Meso-C using GO@MOF-5 as precursor. • GO@Meso-C hybrid material as a host material was applied for sulfur cathode. • Electrochemical performances were improved in sulfur cathode using Go@Meso-C. - Abstract: We present a design and synthesis of a hierarchical architecture of graphene oxide @ mesoporous carbon (GO@Meso-C) using graphene oxide @ metal-organic framework hybrid materials (GO@MOF-5) as both the template and precursor. Active sulfur is encapsulated into the GO@Meso-C matrix prepared via carbonize GO@MOF-5 polyhedrons for high performance lithium sulfur battery. The initial and 100th cycle discharge capacity of GO@Meso-C/S sulfur cathode are as high as 1122 mAh g −1 and 820 mAh g −1 at a current rate of 0.2 C. The remarkably high special capacity and capacity retention rate indicate that the GO@Meso-C is a promising host material for the sulfur cathode in the lithium sulfur battery applications

  11. Hybrid cycles for micro generation

    International Nuclear Information System (INIS)

    Campanari, S.

    2000-01-01

    This paper deals with the main features of two emerging technologies in the field of small-scale power generation, micro turbines and Solid Oxide Fuel Cells, discussing the extremely high potential of their combination into hybrid cycles and their possible role for distributed cogeneration [it

  12. 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...

  13. HYBRID SULFUR RECOVERY PROCESS FOR NATURAL GAS UPGRADING

    International Nuclear Information System (INIS)

    Girish Srinivas; Steven C. Gebhard; David W. DeBerry

    2001-01-01

    This first quarter report of 2001 describes progress on a project funded by the U.S. Department of Energy (DOE) to test a hybrid sulfur recovery process for natural gas upgrading. The process concept represents a low cost option for direct treatment of natural gas streams to remove H(sub 2)S in quantities equivalent to 0.2-25 metric tons (LT) of sulfur per day. This process is projected to have lower capital and operating costs than the competing technologies, amine/aqueous iron liquid redox and amine/Claus/tail gas treating, and have a smaller plant footprint, making it well suited to both on-shore and offshore applications. CrystaSulf(trademark) (service mark of Gas Research Institute) is a new nonaqueous sulfur recovery process that removes hydrogen sulfide (H(sub 2)S) from gas streams and converts it into elemental sulfur. CrystaSulf features high sulfur recovery similar to aqueous-iron liquid redox sulfur recovery processes, but differs from the aqueous processes in that CrystaSulf controls the location where elemental sulfur particles are formed. In the hybrid process, approximately 1/3 of the total H(sub 2)S in the natural gas is first oxidized to SO(sub 2) at low temperatures over a heterogeneous catalyst. Low temperature oxidation is done so that the H(sub 2)S can be oxidized in the presence of methane and other hydrocarbons without oxidation of the hydrocarbons. The project involves the development of a catalyst using laboratory/bench-scale catalyst testing, and then demonstration of the catalyst at CrystaTech's pilot plant in west Texas. During this reporting periods new catalyst formulations were tested. The experiments showed that the newest catalyst has slightly better performance, but catalyst TDA No.2 is still superior overall for use with the hybrid CrystaSulf process due to lower costs. Plans for catalyst pelletization and continued testing are described

  14. Development of once-through hybrid sulfur process for nuclear hydrogen production

    International Nuclear Information System (INIS)

    Jung, Yong Hun

    2010-02-01

    Humanity has been facing major energy challenges such as the severe climate change, threat of energy security and global energy shortage especially for the developing world. Particularly, growing awareness of the global warming has led to efforts to develop the sustainable energy technologies for the harmony of the economy, social welfare and environment. Water-splitting nuclear hydrogen production is expected to help to resolve those challenges, when high energy efficiency and low cost for hydrogen production become possible. Once-through Hybrid Sulfur process (Ot-HyS), proposed in this work, produces hydrogen using the same SO 2 Depolarized water Electrolysis (SDE) process found in the original Hybrid Sulfur cycle (HyS) proposed by Westinghouse, which has the sulfuric acid decomposition (SAD) process using high temperature heat source in order to recover sulfur dioxide for the SDE process. But Ot-HyS eliminated this technical hurdle by replacing it with well-established sulfur combustion process to feed sulfur dioxide to the SDE process. Because Ot-HyS has less technical challenges, Ot-HyS is expected to advance the realization of the large-scale nuclear hydrogen production by feeding an initial nuclear hydrogen stock. Most of the elemental sulfur, at present, is supplied by desulfurization process for environmental reasons during the processing of natural gas and petroleum refining and expected to increase significantly. This recovered sulfur will be burned with oxygen in the sulfur combustion process so that produced sulfur dioxide could be supplied to the SDE process to produce hydrogen. Because the sulfur combustion is a highly exothermic reaction releasing 297 kJ/mol of combustion heat resulting in a large temperature rise, efficiency of the Ot-HyS is expected to be high by recovering this great amount of high grade excess heat with nuclear energy. Sulfuric acid, which is a byproduct of the SDE process, could be sent to the neighboring consumers with or even

  15. 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.

  16. Toward a unifying model for the late Neoproterozoic sulfur cycle

    Science.gov (United States)

    Johnston, D. T.; Gill, B. C.; Ries, J. B.; OBrien, T.; Macdonald, F. A.

    2011-12-01

    The latest Proterozoic has always fascinated Earth historians. Between the long identified enigmas surrounding the sudden appearance of animals and the more recent infatuation with large-sale geochemical anomalies (i.e. the Shuram - Wonaka event), the closing 90 million years of the Proterozoic - the Ediacaran - houses a number of important and unanswered questions. Detailed redox geochemistry and stable isotope reconstructions of stratigraphic units covering this time interval have begun to unravel some of it's mysteries, however much remains to be explained. The sulfur cycle, with it's intimate links to both the marine carbon cycle (through remineralization reactions) and overall oxidant budgets (via seawater sulfate), sits poised to provide a sharp tool to track environmental change. Previous work has recognized this potential, and serves as a point of entrance for our current work. However what is lacking - and the goal of this study - is to place quantitative constraints the geochemical evolution of marine basins through this interval. Here we will present multiple sulfur isotope data from pyrite and sulfates through Ediacaran stratigraphy from the Yukon, Russia and Namibia. To maximize the utility of sulfur isotope studies, we have focused on Ediacaran stratigraphic sections from multiple continents that record both the Shuram anomaly and contain rich fossil records. These sections provide, when interpreted together, a fresh opportunity to revisit the geochemical setting that gave rise to animals. Importantly, the inclusion of multiple sulfur isotope data allows us to place further constraints on the mechanisms underpinning isotopic variability. For instance, when coupled with new experimental data, tighter constraints are provided on how fractionation scales with sulfate concentrations. This may allow for decoupling changes in biological fractionations from modifications to the global sulfur cycle (i.e. changes in seawater sulfate concentrations or the vigor

  17. HYBRID SULFUR RECOVERY PROCESS FOR NATURAL GAS UPGRADING

    International Nuclear Information System (INIS)

    Girish Srinivas; Steven C. Gebhard; David W. DeBerry

    2002-01-01

    This first quarter report of 2002 describes progress on a project funded by the U.S. Department of Energy (DOE) to test a hybrid sulfur recovery process for natural gas upgrading. The process concept represents a low cost option for direct treatment of natural gas streams to remove H(sub 2)S in quantities equivalent to 0.2-25 metric tons (LT) of sulfur per day. This process is projected to have lower capital and operating costs than the competing technologies, amine/aqueous iron liquid redox and amine/Claus/tail gas treating, and have a smaller plant footprint, making it well suited to both on-shore and offshore applications. CrystaSulf(sup SM) (service mark of CrystaTech, Inc.) is a new nonaqueous sulfur recovery process that removes hydrogen sulfide (H(sub 2)S) from gas streams and converts it into elemental sulfur. CrystaSulf features high sulfur recovery similar to aqueous-iron liquid redox sulfur recovery processes, but differs from the aqueous processes in that CrystaSulf controls the location where elemental sulfur particles are formed. In the hybrid process, approximately 1/3 of the total H(sub 2)S in the natural gas is first oxidized to SO(sub 2) at low temperatures over a heterogeneous catalyst. Low temperature oxidation is done so that the H(sub 2)S can be oxidized in the presence of methane and other hydrocarbons without oxidation of the hydrocarbons. The project involves the development of a catalyst using laboratory/bench-scale catalyst testing, and then demonstration of the catalyst at CrystaTech's pilot plant in west Texas. In a previous reporting period tests were done to determine the effect of hydrocarbons such as n-hexane on catalyst performance with and without H(sub 2)S present. The experiments showed that hexane oxidation is suppressed when H(sub 2)S is present. Hexane represents the most reactive of the C1 to C6 series of alkanes. Since hexane exhibits low reactivity under H(sub 2)S oxidation conditions, and more importantly, does not change

  18. 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)

  19. CHOOSING DRIVING CYCLE OF HYBRID VEHICLE

    Directory of Open Access Journals (Sweden)

    A. Vorona

    2011-01-01

    Full Text Available The analysis of existing driving cycles was performed. After comparing some of the cycles, one specific driving cycle was selected for the hybrid vehicle as the most reliable in representing the real moving of the vehicle in operating conditions and which may be reproduced at experimental tests at the modeling roller stand.

  20. Dynamics of biogeochemical sulfur cycling in Mono Lake

    Science.gov (United States)

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

    2017-12-01

    Mono Lake, California is a closed-basin soda lake (pH 9.8) with high sulfate (120mM), and is an ideal natural laboratory for studying microbial sulfur cycling. Mono Lake is typically thermally stratified in summer while mixing completely in winter. However, large snowmelt inputs may induce salinity stratification that persists for up to five years, causing meromixis. During the California drought of 2014-16, the lake has mixed thoroughly each winter, but the abundant 2017 snowmelt may usher in a multi-year stratification. This natural experiment provides an opportunity to investigate the temporal relationship between microbial sulfur cycling and lake biogeochemistry. We analyzed water samples from five depths at two stations in May of 2017, before the onset of meromixis. Water column sulfate isotope values were generally constant with depth, centering at a δ34SVCDT of 17.39 ± 0.06‰. Organic sulfur isotopes were consistently lighter than lake sulfate, with a δ34SVCDT of 15.59 ± 0.56‰. This significant offset between organic and inorganic sulfur contradicts the minimal isotope effect associated with sulfate assimilation. Sediment push core organic values were further depleted, ranging between δ34SVCDT of -8.94‰ and +0.23‰, implying rapid turnover of Mono Lake sulfur pools. Both lipid biomarkers and 16S rRNA gene amplicons identify Picocystis salinarum, a unicellular green alga, as the dominant member of the microbial community. However, bacterial biomarkers and 16S rRNA genes point to microbes capable of sulfur cycling. We found that dsrA increased with depth (R2 = 0.9008, p reducers and sulfide oxidizers after >1 year of stratification. We saw no evidence in May of 2017 of sulfate reducing bacteria across the oxycline. Additionally, no sulfide was detectable in lake bottom waters despite oxygen below 6.25 µM. Preliminary results suggest a dynamic interplay between sulfide oxidation, sulfate reduction, and the onset of lake stratification. Additional

  1. A hybrid mammalian cell cycle model

    Directory of Open Access Journals (Sweden)

    Vincent Noël

    2013-08-01

    Full Text Available Hybrid modeling provides an effective solution to cope with multiple time scales dynamics in systems biology. Among the applications of this method, one of the most important is the cell cycle regulation. The machinery of the cell cycle, leading to cell division and proliferation, combines slow growth, spatio-temporal re-organisation of the cell, and rapid changes of regulatory proteins concentrations induced by post-translational modifications. The advancement through the cell cycle comprises a well defined sequence of stages, separated by checkpoint transitions. The combination of continuous and discrete changes justifies hybrid modelling approaches to cell cycle dynamics. We present a piecewise-smooth version of a mammalian cell cycle model, obtained by hybridization from a smooth biochemical model. The approximate hybridization scheme, leading to simplified reaction rates and binary event location functions, is based on learning from a training set of trajectories of the smooth model. We discuss several learning strategies for the parameters of the hybrid model.

  2. The Conceptual Design of an Integrated Nuclearhydrogen Production Plant Using the Sulfur Cycle Water Decomposition System

    Science.gov (United States)

    Farbman, G. H.

    1976-01-01

    A hydrogen production plant was designed based on a hybrid electrolytic-thermochemical process for decomposing water. The sulfur cycle water decomposition system is driven by a very high temperature nuclear reactor that provides 1,283 K helium working gas. The plant is sized to approximately ten million standard cubic meters per day of electrolytically pure hydrogen and has an overall thermal efficiently of 45.2 percent. The economics of the plant were evaluated using ground rules which include a 1974 cost basis without escalation, financing structure and other economic factors. Taking into account capital, operation, maintenance and nuclear fuel cycle costs, the cost of product hydrogen was calculated at $5.96/std cu m for utility financing. These values are significantly lower than hydrogen costs from conventional water electrolysis plants and competitive with hydrogen from coal gasification plants.

  3. Isotopic insights into microbial sulfur cycling in oil reservoirs

    Directory of Open Access Journals (Sweden)

    Christopher G Hubbard

    2014-09-01

    Full Text Available Microbial sulfate reduction in oil reservoirs (biosouring is often associated with secondary oil production where seawater containing high sulfate concentrations (~28 mM is injected into a reservoir to maintain pressure and displace oil. The sulfide generated from biosouring can cause corrosion of infrastructure, health exposure risks, and higher production costs. Isotope monitoring is a promising approach for understanding microbial sulfur cycling in reservoirs, enabling early detection of biosouring, and understanding the impact of souring. Microbial sulfate reduction is known to result in large shifts in the sulfur and oxygen isotope compositions of the residual sulfate, which can be distinguished from other processes that may be occurring in oil reservoirs, such as precipitation of sulfate and sulfide minerals. Key to the success of this method is using the appropriate isotopic fractionation factors for the conditions and processes being monitored. For a set of batch incubation experiments using a mixed microbial culture with crude oil as the electron donor, we measured a sulfur fractionation factor for sulfate reduction of -30‰. We have incorporated this result into a simplified 1D reservoir reactive transport model to highlight how isotopes can help discriminate between biotic and abiotic processes affecting sulfate and sulfide concentrations. Modeling results suggest that monitoring sulfate isotopes can provide an early indication of souring for reservoirs with reactive iron minerals that can remove the produced sulfide, especially when sulfate reduction occurs in the mixing zone between formation waters containing elevated concentrations of volatile fatty acids and injection water containing elevated sulfate. In addition, we examine the role of reservoir thermal, geochemical, hydrological, operational and microbiological conditions in determining microbial souring dynamics and hence the anticipated isotopic signatures.

  4. A Facile Bottom-Up Approach to Construct Hybrid Flexible Cathode Scaffold for High-Performance Lithium-Sulfur Batteries.

    Science.gov (United States)

    Ghosh, Arnab; Manjunatha, Revanasiddappa; Kumar, Rajat; Mitra, Sagar

    2016-12-14

    Lithium-sulfur batteries mostly suffer from the low utilization of sulfur, poor cycle life, and low rate performances. The prime factors that affect the performance are enormous volume change of the electrode, soluble intermediate product formation, poor electronic and ionic conductivity of S, and end discharge products (i.e., Li 2 S 2 and Li 2 S). The attractive way to mitigate these challenges underlying in the fabrication of a sulfur nanocomposite electrode consisting of different nanoparticles with distinct properties of lithium storage capability, mechanical reinforcement, and ionic as well as electronic conductivity leading to a mechanically robust and mixed conductive (ionic and electronic conductive) sulfur electrode. Herein, we report a novel bottom-up approach to synthesize a unique freestanding, flexible cathode scaffold made of porous reduced graphene oxide, nanosized sulfur, and Mn 3 O 4 nanoparticles, and all are three-dimensionally interconnected to each other by hybrid polyaniline/sodium alginate (PANI-SA) matrix to serve individual purposes. A capacity of 1098 mAh g -1 is achieved against lithium after 200 cycles at a current rate of 2 A g -1 with 97.6% of initial capacity at a same current rate, suggesting the extreme stability and cycling performance of such electrode. Interestingly, with the higher current density of 5 A g -1 , the composite electrode exhibited an initial capacity of 1015 mA h g -1 and retained 71% of the original capacity after 500 cycles. The in situ Raman study confirms the polysulfide absorption capability of Mn 3 O 4 . This work provides a new strategy to design a mechanically robust, mixed conductive nanocomposite electrode for high-performance lithium-sulfur batteries and a strategy that can be used to develop flexible large power storage devices.

  5. Thorium--uranium cycle ICF hybrid concept

    International Nuclear Information System (INIS)

    Frank, T.G.

    1978-01-01

    The results of preliminary studies of a laser-driven fusion-fission hybrid concept utilizing the 232 Th- 233 U breeding cycle are reported. Neutron multiplication in the breeding blanket is provided by a region containing 238 UO 2 and the equilibrium concentration of 239 PuO 2 . Established fission reactor technology is utilized to determine limits on operating conditions for high-temperature fuels and structures. The implications of nonproliferation policies for the operation of fusion-fission hybrid reactors are discussed

  6. An experimental investigation on MEDAD hybrid desalination cycle

    KAUST Repository

    Shahzad, Muhammad Wakil; Thu, Kyaw; Kim, Yong-deuk; Ng, Kim Choon

    2015-01-01

    This paper presents an advanced desalination cycle called "MEDAD" desalination which is a hybrid of the conventional multi-effect distillation (MED) and an adsorption cycle (AD). The combined cycles allow some of MED stages to operate below ambient

  7. COMPONENT DEVELOPMENT NEEDS FOR THE HYBRID SULFUR ELECTROLYZER

    Energy Technology Data Exchange (ETDEWEB)

    Hobbs, D; Hector Colon-Mercado, H; Mark Elvington, M

    2008-05-30

    Fiscal year 2008 studies in electrolyzer component development have focused on the characterization of membrane electrode assemblies (MEA) after performance tests in the single cell electrolyzer, evaluation of electrocatalysts and membranes using a small scale electrolyzer and evaluating the contribution of individual cell components to the overall electrochemical performance. Scanning electron microscopic (SEM) studies of samples taken from MEAs testing in the SRNL single cell electrolyzer test station indicates a sulfur-rich layer forms between the cathode catalyst layer and the membrane. Based on a review of operating conditions for each of the MEAs evaluated, we conclude that the formation of the layer results from the reduction of sulfur dioxide as it passes through the MEA and reaches the catalyst layer at the cathode-membrane interface. Formation of the sulfur rich layer results in partial delamination of the cathode catalyst layer leading to diminished performance. Furthermore we believe that operating the electrolyzer at elevated pressure significantly increases the rate of formation due to increased adsorption of hydrogen on the internal catalyst surface. Thus, identification of a membrane that exhibits much lower transport of sulfur dioxide is needed to reduce the quantity of sulfur dioxide that reaches the cathode catalyst and is reduced to produce the sulfur-rich layer. Three candidate membranes are currently being evaluated that have shown promise from preliminary studies, (1) modified Nafion{reg_sign}, (2) polybenzimidazole (PBI), and (3) sulfonated Diels Alder polyphenylene (SDAPP). Testing examined the activity for the sulfur dioxide oxidation of platinum (Pt) and platinum-alloy catalysts in 30 wt% sulfuric acid solution. Linear sweep voltammetry showed an increase in activity when catalysts in which Pt is alloyed with non-noble transition metals such as cobalt and chromium. However when Pt is alloyed with noble metals, such as iridium or ruthenium

  8. 34S/32S fractionation in sulfur cycles catalyzed by anaerobic bacteria

    Science.gov (United States)

    Fry, B.; Gest, H.; Hayes, J. M.

    1988-01-01

    Stable isotopic distributions in the sulfur cycle were studied with pure and mixed cultures of the anaerobic bacteria, Chlorobium vibrioforme and Desulfovibrio vulgaris. D. vulgaris and C. vibrioforme can catalyze three reactions constituting a complete anaerobic sulfur cycle: reduction of sulfate to sulfide (D. vulgaris), oxidation of sulfide to elemental sulfur (C. vibrioforme), and oxidation of sulfur to sulfate (C. vibrioforme). In all experiments, the first and last reactions favored concentration of the light 32S isotope in products (isotopic fractionation factor epsilon = -7.2 and -1.7%, respectively), whereas oxidation of sulfide favored concentration of the heavy 34S isotope in products (epsilon = +1.7%). Experimental results and model calculations suggest that elemental sulfur enriched in 34S versus sulfide may be a biogeochemical marker for the presence of sulfide-oxidizing bacteria in modern and ancient environments.

  9. HYBRID SULFUR PROCESS REFERENCE DESIGN AND COST ANALYSIS

    Energy Technology Data Exchange (ETDEWEB)

    Gorensek, M.; Summers, W.; Boltrunis, C.; Lahoda, E.; Allen, D.; Greyvenstein, R.

    2009-05-12

    PBMR (Pty.) Ltd. in the RSA, with the Hybrid Sulfur (HyS) Process, under development by the Savannah River National Laboratory (SRNL) in the US as part of the NHI. This work was performed by SRNL, Westinghouse Electric Company, Shaw, PBMR (Pty) Ltd., and Technology Insights under a Technical Consulting Agreement (TCA). Westinghouse Electric, serving as the lead for the PBMR process heat application team, established a cost-shared TCA with SRNL to prepare an updated HyS thermochemical water-splitting process flowsheet, a nuclear hydrogen plant preconceptual design and a cost estimate, including the cost of hydrogen production. SRNL was funded by DOE under the NHI program, and the Westinghouse team was self-funded. The results of this work are presented in this Final Report. Appendices have been attached to provide a detailed source of information in order to document the work under the TCA contract.

  10. 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

  11. ENERGY EFFICIENCY LIMITS FOR A RECUPERATIVE BAYONET SULFURIC ACID DECOMPOSITION REACTOR FOR SULFUR CYCLE THERMOCHEMICAL HYDROGEN PRODUCTION

    Energy Technology Data Exchange (ETDEWEB)

    Gorensek, M.; Edwards, T.

    2009-06-11

    A recuperative bayonet reactor design for the high-temperature sulfuric acid decomposition step in sulfur-based thermochemical hydrogen cycles was evaluated using pinch analysis in conjunction with statistical methods. The objective was to establish the minimum energy requirement. Taking hydrogen production via alkaline electrolysis with nuclear power as the benchmark, the acid decomposition step can consume no more than 450 kJ/mol SO{sub 2} for sulfur cycles to be competitive. The lowest value of the minimum heating target, 320.9 kJ/mol SO{sub 2}, was found at the highest pressure (90 bar) and peak process temperature (900 C) considered, and at a feed concentration of 42.5 mol% H{sub 2}SO{sub 4}. This should be low enough for a practical water-splitting process, even including the additional energy required to concentrate the acid feed. Lower temperatures consistently gave higher minimum heating targets. The lowest peak process temperature that could meet the 450-kJ/mol SO{sub 2} benchmark was 750 C. If the decomposition reactor were to be heated indirectly by an advanced gas-cooled reactor heat source (50 C temperature difference between primary and secondary coolants, 25 C minimum temperature difference between the secondary coolant and the process), then sulfur cycles using this concept could be competitive with alkaline electrolysis provided the primary heat source temperature is at least 825 C. The bayonet design will not be practical if the (primary heat source) reactor outlet temperature is below 825 C.

  12. Hydrogen production using the sulfur-iodine cycle coupled to a VHTR: An overview

    International Nuclear Information System (INIS)

    Vitart, X.; Le Duigou, A.; Carles, P.

    2006-01-01

    The sulfur-iodine thermo-chemical cycle is considered to be one of the most promising routes for massive hydrogen production, using high temperature heat from a Generation IV VHTR. We propose here a brief overview of the main questions raised by this cycle, along with the general lines of French CEA's program

  13. Bacterial sulfur cycle shapes microbial communities in surface sediments of an ultramafic hydrothermal vent field

    DEFF Research Database (Denmark)

    Schauer, Regina; Røy, Hans; Augustin, Nico

    2011-01-01

    RNA sequence analysis, was characterized by the capability to metabolize sulfur components. High sulfate reduction rates as well as sulfide depleted in (34)S further confirmed the importance of the biogeochemical sulfur cycle. In contrast, methane was found to be of minor relevance for microbial life in mat......, these sediments were investigated in order to determine biogeochemical processes and key organisms relevant for primary production. Temperature profiling at two mat-covered sites showed a conductive heating of the sediments. Elemental sulfur was detected in the overlying mat and metal-sulfides in the upper...

  14. Environmental, health, and safety issues of sodium-sulfur batteries for electric and hybrid vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Ohi, J.M.

    1992-09-01

    This report is the first of four volumes that identify and assess the environmental, health, and safety issues involved in using sodium-sulfur (Na/S) battery technology as the energy source in electric and hybrid vehicles that may affect the commercialization of Na/S batteries. This and the other reports on recycling, shipping, and vehicle safety are intended to help the Electric and Hybrid Propulsion Division of the Office of Transportation Technologies in the US Department of Energy (DOE/EHP) determine the direction of its research, development, and demonstration (RD D) program for Na/S battery technology. The reports review the status of Na/S battery RD D and identify potential hazards and risks that may require additional research or that may affect the design and use of Na/S batteries. This volume covers cell design and engineering as the basis of safety for Na/S batteries and describes and assesses the potential chemical, electrical, and thermal hazards and risks of Na/S cells and batteries as well as the RD D performed, under way, or to address these hazards and risks. The report is based on a review of the literature and on discussions with experts at DOE, national laboratories and agencies, universities, and private industry. Subsequent volumes will address environmental, health, and safety issues involved in shipping cells and batteries, using batteries to propel electric vehicles, and recycling and disposing of spent batteries. The remainder of this volume is divided into two major sections on safety at the cell and battery levels. The section on Na/S cells describes major component and potential failure modes, design, life testing and failure testing, thermal cycling, and the safety status of Na/S cells. The section on batteries describes battery design, testing, and safety status. Additional EH S information on Na/S batteries is provided in the appendices.

  15. 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

  16. A Cryptic Sulfur Cycle in Oxygen-Minimum-Zone Waters off the Chilean Coast

    Science.gov (United States)

    Canfield, Don E.; Stewart, Frank J.; Thamdrup, Bo; De Brabandere, Loreto; Dalsgaard, Tage; Delong, Edward F.; Revsbech, Niels Peter; Ulloa, Osvaldo

    2010-12-01

    Nitrogen cycling is normally thought to dominate the biogeochemistry and microbial ecology of oxygen-minimum zones in marine environments. Through a combination of molecular techniques and process rate measurements, we showed that both sulfate reduction and sulfide oxidation contribute to energy flux and elemental cycling in oxygen-free waters off the coast of northern Chile. These processes may have been overlooked because in nature, the sulfide produced by sulfate reduction immediately oxidizes back to sulfate. This cryptic sulfur cycle is linked to anammox and other nitrogen cycling processes, suggesting that it may influence biogeochemical cycling in the global ocean.

  17. The Hybrid Automobile and the Atkinson Cycle

    Science.gov (United States)

    Feldman, Bernard J.

    2008-01-01

    The hybrid automobile is a strikingly new automobile technology with a number of new technological features that dramatically improve energy efficiency. This paper will briefly describe how hybrid automobiles work; what are these new technological features; why the Toyota Prius hybrid internal combustion engine operates on the Atkinson cycle…

  18. Hybrid nuclear cycles for nuclear fission sustainability

    International Nuclear Information System (INIS)

    Piera, M.; Martinez-Val, M. M.

    2007-01-01

    resources could be exploited with such a cycle, using very safe reactors. This percentage is much higher than the actual value for the once-through cycle (0.5 %) and the value for multiple Pu recycling in the MOX scheme (1 %). Moreover, thorium could also be exploited through fertile conversion into U-233 in the subcritical breeders. The separation between energy production (to be done in LWR) and nuclear breeding (to be done in subcritical hybrids) presents a scenario with very appealing safety features and a high potential for an efficient utilization of all natural resources of uranium and thorium, that account for 10 2 4 J, i.e., 25 Gtoe, which is 35,000 times as large as the annual production of Nuclear Energy nowadays, and about 2,500 times as large as the total annual energy consumption all over the globe

  19. Sulfur redox chemistry governs diurnal antimony and arsenic cycles at Champagne Pool, Waiotapu, New Zealand

    Science.gov (United States)

    Ullrich, Maria K.; Pope, James G.; Seward, Terry M.; Wilson, Nathaniel; Planer-Friedrich, Britta

    2013-07-01

    Champagne Pool, a sulfidic hot spring in New Zealand, exhibits distinct diurnal variations in antimony (Sb) and arsenic (As) concentrations, with daytime high and night-time low concentrations. To identify the underlying mobilization mechanisms, five sites along the drainage channel of Champagne Pool were sampled every 2 h during a 24 h period. Temporal variations in elemental concentrations and Sb, As, and sulfur (S) speciation were monitored in the discharging fluid. Total trace element concentrations in filtered and unfiltered samples were analyzed using ICP-MS, and Sb, As and S species were determined by IC-ICP-MS. Sulfur speciation in the drainage channel was dominated by thiosulfate and sulfide at night, while sulfate dominated during the day. The distinct diurnal changes suggest that the transformations are caused by phototrophic sulfur-oxidizing bacteria. These bacteria metabolize thiosulfate and sulfide in daylight to form sulfate and, as suggested by modeling with PhreeqC, elemental sulfur. Sulfide consumption during the day results in undersaturation of antimony sulfides, which triggers the additional release of dissolved Sb. For As, diurnal cycles were much more pronounced in speciation than in total concentrations, with di- and trithioarsenate forming at night due to excess sulfide, and monothioarsenate forming from arsenite and elemental sulfur during the day. Sulfur speciation was thus found to control Sb and As in terms of both solubility and speciation.

  20. Limit Cycle Analysis in a Class of Hybrid Systems

    Directory of Open Access Journals (Sweden)

    Antonio Favela-Contreras

    2016-01-01

    Full Text Available Hybrid systems are those that inherently combine discrete and continuous dynamics. This paper considers the hybrid system model to be an extension of the discrete automata associating a continuous evolution with each discrete state. This model is called the hybrid automaton. In this work, we achieve a mathematical formulation of the steady state and we show a way to obtain the initial conditions region to reach a specific limit cycle for a class of uncoupled and coupled continuous-linear hybrid systems. The continuous-linear term is used in the sense of the system theory and, in this sense, continuous-linear hybrid automata will be defined. Thus, some properties and theorems that govern the hybrid automata dynamic behavior to evaluate a limit cycle existence have been established; this content is explained under a theoretical framework.

  1. Sulfur cycling in contaminated aquifers: What can we learn from oxygen isotopes in sulfate? (Invited)

    Science.gov (United States)

    Knoeller, K.; Vogt, C.; Hoth, N.

    2009-12-01

    Bacterial reduction of dissolved sulfate (BSR) is a key process determining the natural attenuation in many contaminated aquifers. For example, in groundwater bodies affected by acid mine drainage (AMD) BSR reduces the contaminant load by producing alkalinity and facilitating a sustainable fixation of sulfur in the sediment. In aquifers contaminated with petroleum hydrocarbons sulfate may act as a terminal electron acceptor for the anaerobic oxidation of the organic contaminants to carbon dioxide and water. Due to the isotope selectivity of sulfate reducing bacteria, BSR shows the most pronounced isotope fractionation within the sulfur cycle. While sulfur displays a straightforward kinetic enrichment in the residual sulfate described by the enrichment factor epsilon (ɛ), the mechanism of oxygen isotope fractionation is still being discussed controversially. Nevertheless, it is agreed on that oxygen isotope exchange between ambient water and residual sulfate occurs during BSR in natural environments. With respect to this potential isotope exchange, the fractionation parameter theta (θ) is introduced instead of the kinetic enrichment factor epsilon (ɛ). The dual isotope system considering both sulfate-sulfur and sulfate-oxygen isotope fractionation and the respective fractionation parameters ɛ and θ provides an excellent tool for the recognition and quantification of BSR. Beyond that, the dual isotope approach may help identify and estimate interfering sulfur transformations such as re-oxidation and disproportionation processes which is especially vital for the understanding of the overall natural attenuation potential of the investigated aquifers. We present two examples from different field studies showing the benefits of applying the combination of sulfur and oxygen isotopes in dissolved sulfate to reveal the details of the sulfur cycle. The first case study is concerned with the evaluation of the potential for BSR in an AMD-affected aquifer close to an

  2. Energy balance calculations and assessment of two thermochemical sulfur cycles

    International Nuclear Information System (INIS)

    Leger, D.; Lessart, P.; Manaud, J.P.; Benizri, R.; Courvoisier, P.

    1978-01-01

    Thermochemical cyclic processes which include the highly endothermal decomposition of sulphuric acid are promising for hydrogen production by water-splitting. Our study is directed toward two cycles of this family, each involving the formation and decomposition of sulphuric acid and including other reactions using iron sulphide for the first and oxides and bromides of copper and magnesium for the second. Thermochemical analyses of the two cycles are undertaken. Thermodynamic studies of the reactions are carried out, taking into account possible side-reactions. The concentration of reactants, products and by-products resulting from simultaneous equilibria are calculated, the problems of separation thoroughly studied and the flow-diagrams of the processes drawn up. Using as heat source the helium leaving a 3000 MWth high temperature nuclear reactor and organizing internal heat exchange the enthalpy diagrams are drawn up and the net energy balances evaluated. The overall thermal efficiencies are about 28%, a value corresponding to non-optimized process schemes. Possible improvements aiming at energy-saving and increased efficiency are indicated

  3. Active sulfur cycling by diverse mesophilic and thermophilic microorganisms in terrestrial mud volcanoes of Azerbaijan.

    Science.gov (United States)

    Green-Saxena, A; Feyzullayev, A; Hubert, C R J; Kallmeyer, J; Krueger, M; Sauer, P; Schulz, H-M; Orphan, V J

    2012-12-01

    Terrestrial mud volcanoes (TMVs) represent geochemically diverse habitats with varying sulfur sources and yet sulfur cycling in these environments remains largely unexplored. Here we characterized the sulfur-metabolizing microorganisms and activity in four TMVs in Azerbaijan. A combination of geochemical analyses, biological rate measurements and molecular diversity surveys (targeting metabolic genes aprA and dsrA and SSU ribosomal RNA) supported the presence of active sulfur-oxidizing and sulfate-reducing guilds in all four TMVs across a range of physiochemical conditions, with diversity of these guilds being unique to each TMV. The TMVs varied in potential sulfate reduction rates (SRR) by up to four orders of magnitude with highest SRR observed in sediments where in situ sulfate concentrations were highest. Maximum temperatures at which SRR were measured was 60°C in two TMVs. Corresponding with these trends in SRR, members of the potentially thermophilic, spore-forming, Desulfotomaculum were detected in these TMVs by targeted 16S rRNA analysis. Additional sulfate-reducing bacterial lineages included members of the Desulfobacteraceae and Desulfobulbaceae detected by aprA and dsrA analyses and likely contributing to the mesophilic SRR measured. Phylotypes affiliated with sulfide-oxidizing Gamma- and Betaproteobacteria were abundant in aprA libraries from low sulfate TMVs, while the highest sulfate TMV harboured 16S rRNA phylotypes associated with sulfur-oxidizing Epsilonproteobacteria. Altogether, the biogeochemical and microbiological data indicate these unique terrestrial habitats support diverse active sulfur-cycling microorganisms reflecting the in situ geochemical environment. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

  4. A Tire-Sulfur Hybrid Adsorption Denitrification (T-SHAD) process for decentralized wastewater treatment.

    Science.gov (United States)

    Krayzelova, Lucie; Lynn, Thomas J; Banihani, Qais; Bartacek, Jan; Jenicek, Pavel; Ergas, Sarina J

    2014-09-15

    Nitrogen discharges from decentralized wastewater treatment (DWT) systems contribute to surface and groundwater contamination. However, the high variability in loading rates, long idle periods and lack of regular maintenance presents a challenge for biological nitrogen removal in DWT. A Tire-Sulfur Hybrid Adsorption Denitrification (T-SHAD) process was developed that combines nitrate (NO3(-)) adsorption to scrap tire chips with sulfur-oxidizing denitrification. This allows the tire chips to adsorb NO3(-) when the influent loading exceeds the denitrification capacity of the biofilm and release it when NO3(-) loading rates are low (e.g. at night). Three waste products, scrap tire chips, elemental sulfur pellets and crushed oyster shells, were used as a medium in adsorption, leaching, microcosm and up-flow packed bed bioreactor studies of NO3(-) removal from synthetic nitrified DWT wastewater. Adsorption isotherms showed that scrap tire chips have an adsorption capacity of 0.66 g NO3(-)-N kg(-1) of scrap tires. Leaching and microcosm studies showed that scrap tires leach bioavailable organic carbon that can support mixotrophic metabolism, resulting in lower effluent SO4(2-) concentrations than sulfur oxidizing denitrification alone. In column studies, the T-SHAD process achieved high NO3(-)-N removal efficiencies under steady state (90%), variable flow (89%) and variable concentration (94%) conditions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Dual-shell hollow polyaniline/sulfur-core/polyaniline composites improving the capacity and cycle performance of lithium–sulfur batteries

    Energy Technology Data Exchange (ETDEWEB)

    An, Yanling; Wei, Pan; Fan, Meiqiang, E-mail: fanmeiqiang@126.com; Chen, Da; Chen, Haichao; Ju, QiangJian; Tian, Guanglei; Shu, Kangying

    2016-07-01

    Highlights: • A dual core-shell hPANI/S/PANI composite was prepared in situ synthesis. • Cycle performance of the hPANI/S/PANI composite was enhanced. • The improvement was due to fine sulfur particles wrapped by two PANI films. • Some positive effects were elaborated. - Abstract: In this study, a dual-shell hollow polyaniline/sulfur-core/polyaniline (hPANI/S/PANI) composite was prepared by successively depositing PANI, S, and PANI on the surface of a template silicon sphere. The electrochemical properties of this composite were evaluated using a lithium plate as an anode in lithium/sulfur cells. The hPANI/S/PANI composite showed a discharge capacity of 572.2 mAh g{sup −1} after 214 cycles at 0.1 C, and the Coulombic efficiency was above 87% in the whole charge/discharge cycle. The improved cycle property of the hPANI/S/PANI composite can be ascribed to the fine sulfur particles homogeneously deposited on the PANI surface and sprawled inside the two PANI layers during the charge/discharge cycle. This behavior stabilized the nanostructure of sulfur and enhanced its conductivity.

  6. Unraveling multiple phases of sulfur cycling during the alteration of ancient ultramafic oceanic lithosphere

    Science.gov (United States)

    Schwarzenbach, Esther M.; Gill, Benjamin C.; Johnston, David T.

    2018-02-01

    Ultramafic-hosted hydrothermal systems - characterized by ongoing serpentinization reactions - exert an important influence on the global sulfur cycle. Extensive water-rock interaction causes elemental exchange between seawater and the oceanic lithosphere, effectively removing sulfate from seawater through both abiogenic and biogenic processes. Here, we use bulk rock multiple sulfur isotope signatures (32S, 33S, 34S) and in situ sulfide analyses together with petrographic observations to track the sulfur cycling processes and the hydrothermal evolution of ancient peridotite-hosted hydrothermal systems. We investigate serpentinized peridotites from the Northern Apennine ophiolite in Italy and the Santa Elena ophiolite in Costa Rica and compare those with the Iberian Margin (Ocean Drilling Program (ODP) Leg 149 and 173) and the 15°20‧N Fracture Zone along the Mid-Atlantic Ridge (ODP Leg 209). In situ measurements of sulfides in the Northern Apennine serpentinites preserve a large range in δ34Ssulfide of -33.8 to +13.3‰ with significant heterogeneities within single sulfide grains and depending on mineralogy. Detailed mineralogical investigation and comparison with bulk rock Δ33Ssulfide and in situ δ34Ssulfide data implies a thermal evolution of the system from high temperatures (∼350 °C) that allowed thermochemical sulfate reduction and input of hydrothermal sulfide to lower temperatures (rock associated with detachment faulting along a mid-ocean ridge spreading center. The Santa Elena peridotites preserve distinct signatures for fluid circulation at high temperatures with both closed system thermochemical sulfate reduction and input of mafic-derived sulfur. In addition, the peridotites provide strong evidence that low Ca2+ concentrations in peridotite-hosted systems can limit sulfate removal during anhydrite precipitation at temperatures above 150 °C. This may play a central role for the availability of sulfate to microbial communities within these

  7. Hybrid solar central receiver for combined cycle power plant

    Science.gov (United States)

    Bharathan, Desikan; Bohn, Mark S.; Williams, Thomas A.

    1995-01-01

    A hybrid combined cycle power plant including a solar central receiver for receiving solar radiation and converting it to thermal energy. The power plant includes a molten salt heat transfer medium for transferring the thermal energy to an air heater. The air heater uses the thermal energy to preheat the air from the compressor of the gas cycle. The exhaust gases from the gas cycle are directed to a steam turbine for additional energy production.

  8. Interactive effects of vertical mixing, solar radiation and microbial activity on oceanic dimethylated sulfur cycling

    OpenAIRE

    Galí Tàpias, Martí

    2012-01-01

    The production and subsequent emission of volatile compounds is one of the numerous ways by which microbial plankton participate in the cycling of elements and influence the Earth's climate. Dimethylsulfide (DMS), produced by enzymatic decomposition of the algal intracellular compound dimethylsulfoniopropionate (DMSP), is the more abundant organic volatile in the upper ocean. Its global emission amounts ca. 28 Tg S per year, and represents the main biogenic source of sulfur to the troposphere...

  9. Fuel cell hybrid taxi life cycle analysis

    Energy Technology Data Exchange (ETDEWEB)

    Baptista, Patricia, E-mail: patricia.baptista@ist.utl.pt [IDMEC-Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa (Portugal); Ribau, Joao; Bravo, Joao; Silva, Carla [IDMEC-Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa (Portugal); Adcock, Paul; Kells, Ashley [Intelligent Energy, Charnwood Building, HolywellPark, Ashby Road, Loughborough, LE11 3GR (United Kingdom)

    2011-09-15

    A small fleet of classic London Taxis (Black cabs) equipped with hydrogen fuel cell power systems is being prepared for demonstration during the 2012 London Olympics. This paper presents a Life Cycle Analysis for these vehicles in terms of energy consumption and CO{sub 2} emissions, focusing on the impacts of alternative vehicle technologies for the Taxi, combining the fuel life cycle (Tank-to-Wheel and Well-to-Tank) and vehicle materials Cradle-to-Grave. An internal combustion engine diesel taxi was used as the reference vehicle for the currently available technology. This is compared to battery and fuel cell vehicle configurations. Accordingly, the following energy pathways are compared: diesel, electricity and hydrogen (derived from natural gas steam reforming). Full Life Cycle Analysis, using the PCO-CENEX drive cycle, (derived from actual London Taxi drive cycles) shows that the fuel cell powered vehicle configurations have lower energy consumption (4.34 MJ/km) and CO{sub 2} emissions (235 g/km) than both the ICE Diesel (9.54 MJ/km and 738 g/km) and the battery electric vehicle (5.81 MJ/km and 269 g/km). - Highlights: > A Life Cycle Analysis of alternative vehicle technologies for the London Taxi was performed. > The hydrogen powered vehicles have the lowest energy consumption and CO{sub 2} emissions results. > A hydrogen powered solution can be a sustainable alternative in a full life cycle framework.

  10. Fuel cell hybrid taxi life cycle analysis

    International Nuclear Information System (INIS)

    Baptista, Patricia; Ribau, Joao; Bravo, Joao; Silva, Carla; Adcock, Paul; Kells, Ashley

    2011-01-01

    A small fleet of classic London Taxis (Black cabs) equipped with hydrogen fuel cell power systems is being prepared for demonstration during the 2012 London Olympics. This paper presents a Life Cycle Analysis for these vehicles in terms of energy consumption and CO 2 emissions, focusing on the impacts of alternative vehicle technologies for the Taxi, combining the fuel life cycle (Tank-to-Wheel and Well-to-Tank) and vehicle materials Cradle-to-Grave. An internal combustion engine diesel taxi was used as the reference vehicle for the currently available technology. This is compared to battery and fuel cell vehicle configurations. Accordingly, the following energy pathways are compared: diesel, electricity and hydrogen (derived from natural gas steam reforming). Full Life Cycle Analysis, using the PCO-CENEX drive cycle, (derived from actual London Taxi drive cycles) shows that the fuel cell powered vehicle configurations have lower energy consumption (4.34 MJ/km) and CO 2 emissions (235 g/km) than both the ICE Diesel (9.54 MJ/km and 738 g/km) and the battery electric vehicle (5.81 MJ/km and 269 g/km). - Highlights: → A Life Cycle Analysis of alternative vehicle technologies for the London Taxi was performed. → The hydrogen powered vehicles have the lowest energy consumption and CO 2 emissions results. → A hydrogen powered solution can be a sustainable alternative in a full life cycle framework.

  11. A hybrid multi-effect distillation and adsorption cycle

    KAUST Repository

    Thu, Kyaw

    2013-04-01

    This paper describes the development of a simple hybrid desalination system of a Multi-Effect Distillation (MED) and an adsorption (AD) cycle operating at sub-atmospheric pressures and temperatures. By hybridizing the conventional MED with an AD cycle, there is a symbiotic enhancement of performances of both cycles. The performance enhancement is attributed to (i) the cascade of adsorbent\\'s regeneration temperature and this extended the usage of thermal energy emanating from the brine heater and (ii) the vapor extraction from the last MED stage by AD cycle which provides the effect of lowering saturation temperatures of all MED stages to the extent of 5°C, resulting in scavenging of heat leaks into the MED stages from the ambient. The combined effects of the hybrid cycles increase the water production capacity of the desalination plant by nearly twofolds.In this paper, we demonstrate a hybrid cycle by simulating an 8-stage MED cycle which is coupled to an adsorption cycle for direct vapor extraction from the last MED stage. The sorption properties of silica gel is utilized (acting as a mechanical vapor compressor) to reduce the saturation temperatures of MED stages. The modeling utilizes the adsorption isotherms and kinetics of the adsorbent. +. adsorbate (silica-gel. +. water) pair along with the governing equations of mass, energy and concentration. For a 8-stage MED and AD cycles operating at assorted temperatures of 65-90°C, the results show that the water production rate increases from 60% to twofolds when compared to the MED alone. The performance ratio (PR) and gain output ratio (GOR) also improve significantly. © 2012 Elsevier Ltd.

  12. The hybrid two stage anticlockwise cycle for ecological energy conversion

    Directory of Open Access Journals (Sweden)

    Cyklis Piotr

    2016-01-01

    Full Text Available The anticlockwise cycle is commonly used for refrigeration, air conditioning and heat pumps applications. The application of refrigerant in the compression cycle is within the temperature limits of the triple point and the critical point. New refrigerants such as 1234yf or 1234ze have many disadvantages, therefore natural refrigerants application is favourable. The carbon dioxide and water can be applied only in the hybrid two stages cycle. The possibilities of this solutions are shown for refrigerating applications, as well some experimental results of the adsorption-compression double stages cycle, powered with solar collectors are shown. As a high temperature cycle the adsorption system is applied. The low temperature cycle is the compression stage with carbon dioxide as a working fluid. This allows to achieve relatively high COP for low temperature cycle and for the whole system.

  13. Hybrid Combined Cycles with Biomass and Waste Fired Bottoming Cycle - a Literature Study

    Energy Technology Data Exchange (ETDEWEB)

    Petrov, Miroslav P.

    2002-02-01

    Biomass is one of the main natural resources in Sweden. The present low-CO{sub 2} emission characteristics of the Swedish electricity production system (hydro and nuclear) can be retained only by expansion of biofuel applications for energy purposes. Domestic Swedish biomass resources are vast and renewable, but not infinite. They must be utilized as efficiently as possible, in order to make sure that they meet the conditions for sustainability in the future. Application of efficient power generation cycles at low costs is essential for meeting this challenge. This applies also to municipal solid waste incineration with energy extraction, which should be preferred to its dumping in landfills. Hybrid dual-fuel combined cycle units are a simple and affordable way to increase the electric efficiency of biofuel energy utilization, without big investments, uncertainties or loss of reliability arising from complicated technologies. Configurations of such power cycles are very flexible and reliable. Their potential for high electric efficiency in condensing mode, high total efficiency in combined heat and power mode and unrivalled load flexibility is explored in this project. The present report is a literature study that concentrates on certain biomass utilization technologies, in particular the design and performance of hybrid combined cycle power units of various configurations, with gas turbines and internal combustion engines as topping cycles. An overview of published literature and general development trends on the relevant topic is presented. The study is extended to encompass a short overview of biomass utilization as an energy source (focusing on Sweden), history of combined cycles development with reference especially to combined cycles with supplementary firing and coal-fired hybrid combined cycles, repowering of old steam units into hybrid ones and combined cycles for internal combustion engines. The hybrid combined cycle concept for municipal solid waste

  14. Design and evaluation of hybrid meso-porous silicas to uranium extraction from sulfuric media

    International Nuclear Information System (INIS)

    Charlot, Alexandre

    2016-01-01

    Nuclear industries are perpetually looking for technical, economic and environmental progresses. Important volumes of acidic waste are generated by nuclear plants of the front end. The extraction of uranium from these solutions is required to decontaminate effluents (decrease of the radioactivity) and value uranium (re-incorporation in the cycle). Uranium leaching is mostly achieved using sulfuric acid leading to the production of aqueous effluents that contain a large grade of sulfate complexes. In such conditions, uranyl sulfate complexes constitute the predominant uranium species in solution and its extraction represents a real scientific and technological challenge. Commonly, precipitation, solvent extraction or solid phase extraction are used. The last one is particularly adapted for low grade solutions due to it weak environmental footprint (no solvent are handling) and the facility of the process involved (i.e. fixed bed column). among the available solid-phase extraction candidates, hybrid meso-porous silicas get a crucial part. They develop a very high specific surface areas and a driven porosity which give them a high potential of extraction capacities. In this manuscript the tailoring and the evaluation of hybrid meso-porous silicas have been investigated. Firstly, the work focus on the organic part grafted by post-synthetic pathway, the N,N-dialkyl-carbamoyl-phosphonate based molecules have been identified to get interesting extraction properties. This study emphasizes that acid groups are required and that alkyl substituents get a real importance in the extraction efficiency. On the second hand, the role of pore size has been investigated. The results obtained disclosed that pores size diameters directly impact the grafting ratio as well as the homogeneity of the material: (1) materials with a pore size below 3 nm are heterogeneously functionalized due to steric issues, (2) a homogeneous organic monolayer grafted onto the silica skeleton occurs when

  15. Global warming potential of the sulfur-iodine process using life cycle assessment methodology

    International Nuclear Information System (INIS)

    Lattin, William C.; Utgikar, Vivek P.

    2009-01-01

    A life cycle assessment (LCA) of one proposed method of hydrogen production - thermochemical water-splitting using the sulfur-iodine cycle couple with a very high-temperature nuclear reactor - is presented in this paper. Thermochemical water-splitting theoretically offers a higher overall efficiency than high-temperature electrolysis of water because heat from the nuclear reactor is provided directly to the hydrogen generation process, instead of using the intermediate step of generating electricity. The primary heat source for the S-I cycle is an advanced nuclear reactor operating at temperatures corresponding to those required by the sulfur-iodine process. This LCA examines the environmental impact of the combined advanced nuclear and hydrogen generation plants and focuses on quantifying the emissions of carbon dioxide per kilogram of hydrogen produced. The results are presented in terms of global warming potential (GWP). The GWP of the system is 2500 g carbon dioxide-equivalent (CO 2 -eq) per kilogram of hydrogen produced. The GWP of this process is approximately one-sixth of that for hydrogen production by steam reforming of natural gas, and is comparable to producing hydrogen from wind- or hydro-electric conventional electrolysis. (author)

  16. 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.

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

    Directory of Open Access Journals (Sweden)

    Anne M. Spain

    2015-09-01

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

  18. An experimental investigation on MEDAD hybrid desalination cycle

    KAUST Repository

    Shahzad, Muhammad Wakil

    2015-04-02

    This paper presents an advanced desalination cycle called "MEDAD" desalination which is a hybrid of the conventional multi-effect distillation (MED) and an adsorption cycle (AD). The combined cycles allow some of MED stages to operate below ambient temperature, as low as 5. °C in contrast to the conventional MED. The MEDAD cycle results in a quantum increase of distillate production at the same top-brine condition. Being lower than the ambient temperature for the bottom stages of hybrid cycle, ambient energy can now be scavenged by the MED processes whilst the AD cycle is powered by low temperature waste heat from exhaust or renewable sources. In this paper, we present the experiments of a 3-stage MED and MEDAD plants. These plants have been tested at assorted heat source temperatures from 15. °C to 70. °C and with portable water as a feed. All system states are monitored including the distillate production and power consumption and the measured results are expressed in terms of performance ratio (PR). It is observed that the synergetic matching of MEDAD cycle led to a quantum increase in distillate production, up to 2.5 to 3 folds vis-a-vis to a conventional MED of the same rating. © 2015 Elsevier Ltd.

  19. Dual Pressure versus Hybrid Recuperation in an Integrated Solid Oxide Fuel Cell Cycle – Steam Cycle

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2014-01-01

    A SOFC (solid oxide fuel cell) cycle running on natural gas was integrated with a ST (steam turbine) cycle. The fuel is desulfurized and pre-reformed before entering the SOFC. A burner was used to combust the remaining fuel after the SOFC stacks. The off-gases from the burner were used to produce...... pressure configuration steam cycle combined with SOFC cycle (SOFC-ST) was new and has not been studied previously. In each of the configuration, a hybrid recuperator was used to recovery the remaining energy of the off-gases after the HRSG. Thus, four different plants system setups were compared to each...... other to reveal the most superior concept with respect to plant efficiency and power. It was found that in order to increase the plant efficiency considerably, it was enough to use a single pressure with a hybrid recuperator instead of a dual pressure Rankine cycle....

  20. Enhanced Cycling Stability of Lithium–Sulfur batteries by Electrostatic-Interaction

    International Nuclear Information System (INIS)

    Ma, Zhaoling; Huang, Xiaobing; Jiang, Qianqian; Huo, Jia; Wang, Shuangyin

    2015-01-01

    Highlights: • Electrostatic interaction is utilized to hinder the shuttling of polysulfides. • Directly functionalizing SG can better prolong the cycle life of Li–S batteries. • SG/PDDA showed significantly improved capacity retention. - Abstract: Lithiums–sulfur battery is considered as one of the most promising energy storage devices to replace the current Li ion batteries because of its high theoretical capacity of 1675 mA h g −1 . However, the poor cycle stability hinders the further development of this battery system. In order to improve the stability of Li–S batteries, the diffusion of polysulfides from electrodes into electrolyte should be suppressed. Herein, we utilize a positively charged polyelectrolyte to functionalize the electrode materials with the aim to hamper the polysulfides dissolution via electrostatic interaction between strong positively charged polyelectrolyte and negatively charged polysulfides anion. The effect of the functionalization quantity of poly(diallyl dimethylammonium) chloride (PDDA) and functionalization sequence on cycling performances is investigated in detail. It is found that the sulfur–graphene composite (SG) directly functionalized with 10 times PDDA exhibited best cycling stability. At a discharge current density of 0.2 C, much higher capacity retention was realized on the functionalized electrodes than the unfunctionalized (81% vs. 47.3%) after 120 cycles. The as-observed results demonstrate that the electrostatic interaction can effectively prolong the cycling life of Li–S batteries, which provides a new promising strategy for improving the electrochemical performance of Li–S batteries.

  1. Energy generation and the sulfur-carbon cycles: Final technical report for period March 1981 thru February 1985

    International Nuclear Information System (INIS)

    Zeikus, J.G.

    1987-05-01

    The aim of this research was to understand the role of anaerobic bacteria in natural and man-influenced carbon cycles in nature. The major goal was to elucidate how sulfur metabolism influenced organic decomposition in aquatic sediments. The research compared these processes in two different anaerobic ecosystems: the sulfate-depleted sediments of Lake Mendota, Wisconsin and the sulfate-saturated sediments of Great Salt Lake, Utah. The approach was both ecological and physiological, and employed both in situ characterization of carbon and sulfur metabolism with radiotracers and laboratory species isolation-characterization studies with pure and defined mixed cultures to demonstrate the prevalent environmental paths of carbon electrons, and sulfur during the anaerobic decomposition of organic matter. The significance of this research encompassed fundamental knowledge of the carbon sulfur cycles, applied knowledge on the microbial genesis of flammable gas and oil and extended knowledge on the diversity and metabolic activity of obligately anaerobic bacteria in nature. 13 refs

  2. Polonium in Florida groundwater and its possible relationship to the sulfur cycle and bacteria

    International Nuclear Information System (INIS)

    Harada, K.; Burnett, W.C.; LaRock, P.A.; Cowart, J.B.

    1989-01-01

    The last radioactive member of the 238 U natural decay-series, 210 Po is normally considered a very particle-reactive isotope. Analysis of most natural waters shows that 210 Po is present at very low activities, usually even lower than its insoluble precursor, 210 Pb. The authors have recently discovered, however, that 210 Po exists at very high concentrations in groundwaters of some shallow aquifers in west central Florida. These waters tend to be fairly acidic (pH 222 Rn. Detailed study of one well with extraordinary levels of 210 Po (∼ 1000 dpm/l) indicates that: (1) 210 Po in this water is in great excess of radioactive equilibrium with its predecessors 210 Pb and 210 Bi; (2) most Po in this water exists in a form which does not coprecipitate with an iron hydroxide scavenge; and (3) the conversion of soluble (0.2 μm filter) to particulate Po occurs over a time scale of a few days during sulfide oxidation. The authors suspect that Po cycling in this environment is related to the sulfur cycle and may, therefore, be influenced by sulfur bacteria

  3. NATO Advanced Research Workshop on The Biogeochemical Cycling of Sulfur and Nitrogen in the Remote Atmosphere

    CERN Document Server

    Charlson, Robert; Andreae, Meinrat; Rodhe, Henning

    1985-01-01

    Viewed from space, the Earth appears as a globe without a beginning or an end. Encompassing the globe is the atmosphere with its three phases-­ gaseous, liquid, and solid--moving in directions influenced by sunlight, gravity, and rotation. The chemical compositions of these phases are determined by biogeochemical cycles. Over the past hundred years, the processes governing the rates and reactions in the atmospheric biogeochemical cycles have typically been studied in regions where scientists lived. Hence, as time has gone by, the advances in our knowledge of atmospheric chemical cycles in remote areas have lagged substantially behind those for more populated areas. Not only are the data less abundant, they are also scattered. Therefore, we felt a workshop would be an excellent mechanism to assess the state­ of-knowledge of the atmospheric cycles of sulfur and nitrogen in remote areas and to make recommendations for future research. Thus, a NATO Advanced Research Workshop '~he Biogeochemical Cycling of Sulfu...

  4. Microbial contributions to coupled arsenic and sulfur cycling in the acid-sulfide hot spring Champagne Pool, New Zealand.

    Science.gov (United States)

    Hug, Katrin; Maher, William A; Stott, Matthew B; Krikowa, Frank; Foster, Simon; Moreau, John W

    2014-01-01

    Acid-sulfide hot springs are analogs of early Earth geothermal systems where microbial metal(loid) resistance likely first evolved. Arsenic is a metalloid enriched in the acid-sulfide hot spring Champagne Pool (Waiotapu, New Zealand). Arsenic speciation in Champagne Pool follows reaction paths not yet fully understood with respect to biotic contributions and coupling to biogeochemical sulfur cycling. Here we present quantitative arsenic speciation from Champagne Pool, finding arsenite dominant in the pool, rim and outflow channel (55-75% total arsenic), and dithio- and trithioarsenates ubiquitously present as 18-25% total arsenic. In the outflow channel, dimethylmonothioarsenate comprised ≤9% total arsenic, while on the outflow terrace thioarsenates were present at 55% total arsenic. We also quantified sulfide, thiosulfate, sulfate and elemental sulfur, finding sulfide and sulfate as major species in the pool and outflow terrace, respectively. Elemental sulfur concentration reached a maximum at the terrace. Phylogenetic analysis of 16S rRNA genes from metagenomic sequencing revealed the dominance of Sulfurihydrogenibium at all sites and an increased archaeal population at the rim and outflow channel. Several phylotypes were found closely related to known sulfur- and sulfide-oxidizers, as well as sulfur- and sulfate-reducers. Bioinformatic analysis revealed genes underpinning sulfur redox transformations, consistent with sulfur speciation data, and illustrating a microbial role in sulfur-dependent transformation of arsenite to thioarsenate. Metagenomic analysis also revealed genes encoding for arsenate reductase at all sites, reflecting the ubiquity of thioarsenate and a need for microbial arsenate resistance despite anoxic conditions. Absence of the arsenite oxidase gene, aio, at all sites suggests prioritization of arsenite detoxification over coupling to energy conservation. Finally, detection of methyl arsenic in the outflow channel, in conjunction with

  5. 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

  6. Analysis of alternative flow sheets for the hybrid chlorine cycle

    Energy Technology Data Exchange (ETDEWEB)

    Gooding, Charles H. [Department of Chemical and Biomolecular Engineering, 209 Earle Hall, Clemson University, Clemson, SC 29634-0909 (United States)

    2009-05-15

    This paper reports the results of the most complete conceptual study conducted to date on hydrogen production using the hybrid chlorine cycle. Three alternative process flow sheets were developed, each capable of producing hydrogen at 35 C (308 K) and 21 bar. The alternative approaches differ primarily in the way HCl is isolated and converted to hydrogen and chlorine gases. Aspen Plus trademark simulation software was used to model the unit processes, supplemented where necessary by custom Excel spreadsheets. Major equipment was sized for a 200-million kg/yr plant; feasible materials of construction were identified; fixed capital investments and variable costs were estimated. Estimated net thermal efficiencies of the flow sheets range from 30% to 36%, based on the lower heating value of the hydrogen produced. With electrical power valued at $0.05/kWh, the cost of hydrogen produced by the hybrid chlorine cycle would be at least $3/kg. These results indicate that direct electrolysis of water is a more attractive way to produce hydrogen than any presently conceived version of the hybrid chlorine cycle. (author)

  7. An efficient hybrid sulfur process using PEM electrolysis with a bayonet decomposition reactor - HTR2008-58207

    International Nuclear Information System (INIS)

    Gorensek, M. B.; Summers, W. A.; Lahoda, E. J.; Bolthrunis, C. O.; Greyvenstein, R.

    2008-01-01

    The Hybrid Sulfur (HyS) Process is being developed to produce hydrogen by water-splitting using heat from advanced nuclear reactors. It has the potential for high efficiency and competitive hydrogen production cost, and has been demonstrated at a laboratory scale. As a two-step process, the HyS is one of the simplest thermochemical cycles. The sulfuric acid decomposition reaction is common to all sulfur cycles, including the Sulfur-Iodine (SI) cycle. What distinguishes the HyS Process from the other sulfur cycles is the use of sulfur dioxide (SO 2 ) to depolarize the anode of a water electrolyzer. The two critical HyS Process components are the SO 2 - depolarized electrolyzer (SDE), and the high-temperature decomposition reactor. A proton exchange membrane (PEM)- type SDE and a silicon carbide bayonet-type high-temperature decomposition reactor are being developed for DOE's Nuclear Hydrogen Initiative (NHI) by Savannah River National Laboratory (SRNL) and by Sandia National Laboratories (SNL), respectively. The ultimate goal of the NHI-sponsored work is to couple the SDE and the reactor in an integrated laboratory scale experiment to prove the technical readiness of the HyS cycle for the NGNP demonstration. This paper describes the flowsheet that is being prepared to combine these two components into a viable process and presents the latest performance projections and economics for a HyS Process coupled to a PBMR heat source. The basic flowsheet for this process has been described elsewhere [4]. It requires an acid concentration section because the SDE product, which is limited to no more than 50% H 2 SO 4 by cell voltage considerations, is too dilute to be fed directly to the bayonet, which needs at least 65% H 2 SO 4 in the feed for acceptable performance. Optimization involved trade-offs between decomposition reaction and acid concentration heat requirements. The PBMR heat source can split its heat output between the decomposition reaction and either steam

  8. Sulfur isotopic analysis of carbonyl sulfide and its application for biogeochemical cycles

    Science.gov (United States)

    Hattori, Shohei; Kamezaki, Kazuki; Ogawa, Takahiro; Toyoda, Sakae; Katayama, Yoko; Yoshida, Naohiro

    2016-04-01

    Carbonyl sulfide (OCS or COS) is the most abundant gas containing sulfur in the atmosphere, with an average mixing ratio of 500 p.p.t.v. in the troposphere. OCS is suggested as a sulfur source of the stratospheric sulfate aerosols (SSA) which plays an important role in Earth's radiation budget and ozone depletion. Therefore, OCS budget should be validated for prediction of climate change, but the global OCS budget is imbalance. Recently we developed a promising new analytical method for measuring the stable sulfur isotopic compositions of OCS using nanomole level samples: the direct isotopic analytical technique of on-line gas chromatography-isotope ratio mass spectrometry (GC-IRMS) using fragmentation ions S+ (Hattori et al., 2015). The first measurement of the δ34S value for atmospheric OCS coupled with isotopic fractionation for OCS sink reactions in the stratosphere (Hattori et al., 2011; Schmidt et al., 2012; Hattori et al., 2012) explains the reported δ34S value for background stratospheric sulfate, suggesting that OCS is a potentially important source for background (nonepisodic or nonvolcanic) stratospheric sulfate aerosols. This new method measuring δ34S values of OCS can be used to investigate OCS sources and sinks in the troposphere to better understand its cycle. It is known that some microorganisms in soil can degrade OCS, but the mechanism and the contribution to the OCS in the air are still uncertain. In order to determine sulfur isotopic enrichment factor of OCS during degradation via microorganisms, incubation experiments were conducted using strains belonging to the genera Mycobacterium, Williamsia and Cupriavidus, isolated from natural soil environments (Kato et al., 2008). As a result, sulfur isotope ratios of OCS were increased during degradation of OCS, indicating that reaction for OC32S is faster than that for OC33S and OC34S. OCS degradation via microorganisms is not mass-independent fractionation (MIF) process, suggesting that this

  9. Role of sulfur redox cycling on arsenic mobilization in aquifers of Datong Basin, northern China

    International Nuclear Information System (INIS)

    Pi, Kunfu; Wang, Yanxin; Xie, Xianjun; Ma, Teng; Su, Chunli; Liu, Yaqing

    2017-01-01

    Sulfur redox cycling potentially exerts important influences on arsenic (As) fate in shallow groundwater systems. Hydrochemical and sediment geochemical analysis combined with thermodynamic modeling study were conducted at Datong Basin to elaborate the effects of sulfur redox cycling on As speciation and mobilization under a strongly reducing environment. Dissolved As and sulfide concentration in 32 groundwater samples with depths of 19–40 m below the land surface varied from 8 to 2700 μg/L and from <5 to 490 μg/L, respectively, while dissolved Fe(II) was relatively low ranging from <20 to 280 μg/L. The apparent co-increase in dissolved sulfide and As concentration, especially for samples with As content larger than 500 μg/L, indicates that sulfidogenesis may significantly contribute to the mobilization of As via sulfide-induced reduction of both As-bearing Fe(III) oxide minerals and As(V). Thermodynamic calculations indicate that groundwater As might be also thiolated in the presence of high-level sulfide, particularly to a large extent for As(V) speciation, instead of sequestration by As-sulfide precipitates. Results of sequential extraction and scanning electron microscopy array on sediments indicate the presence of Fe(II) sulfide mineral phases and an appreciable amount of co-existent As in the sediments, suggesting the precipitation of Fe(II) sulfides can restrict the build-up of dissolved Fe(II) and sequester As from groundwater, but not strongly enough, thereby lowering down As to a moderate level of about 500 μg/L. Thus, redox processes involving As, S and Fe species under sulfidic conditions as observed in Datong Basin not only facilitate the enrichment of As(III) species and As(V) potentially existing as thiolated species, but also the depletion of Fe(II) concentration in groundwater due to Fe(II) sulfide formation. - Highlights: • Effects of sulfur redox cycling on As enrichment were clarified in Datong. • Co-increase in aqueous As and

  10. Experimental studies on optimal process of the iodine-sulfur cycle for nuclear hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Ho Joon

    2010-02-15

    For nuclear hydrogen production, we selected Iodine-Sulfur (I-S) cycle as the most promising one by screening process among 115 thermo-chemical water splitting technologies. We developed a thermo-physical model for the hydrogen-iodide (HI) VLE and decomposition behavior in the iodine-sulfur (IS) cycle to improve the conventional I-S cycle suggested by GA. Neumann's modified NRTL model was improved by correcting an unphysical assumption for the non-randomness parameter, and using the two-step equilibrium approach for the HI decomposition modeling. However, the parameters of the model were decided through regression with the 271 sets of existing experimental data: the accuracy of the model should be improved by more experimental data over all operating ranges, especially, in the high temperature and high pressure regions. To obtain the data of those regions, an autoclave for high temperature and high pressure was designed and manufactured. Various materials and surface coating technologies were investigated for preventing corrosion from acids. However, we have currently failed to overcome the corrosion problems with highly corrosive acids at a high temperature and high pressure. We experimentally validated that azeotropic constraint between acid and H{sub 2}O undermined the total efficiency of the I-S cycle. As mentioned above, the conventional I-S cycle suffers from low thermal efficiency and highly corrosive streams. To alleviate these problems, we have proposed the optimal operating conditions for the Bunsen reaction and devised a new KAIST flowsheet that produces highly enriched HI through spontaneous L-L phase separation and simple flash processes under low pressure. A series of phase separation experiments were performed to validate the new flowsheet and extend its feasibility. When the molar ratio of I{sub 2}/H{sub 2}SO{sub 4} in the feed increased from 2 to 4, the molar ratio of HI/(HI+H{sub 2}O) in the HI{sub x} phase improved from 0.157 to 0.22, which

  11. Experimental studies on optimal process of the iodine-sulfur cycle for nuclear hydrogen production

    International Nuclear Information System (INIS)

    Yoon, Ho Joon

    2010-02-01

    For nuclear hydrogen production, we selected Iodine-Sulfur (I-S) cycle as the most promising one by screening process among 115 thermo-chemical water splitting technologies. We developed a thermo-physical model for the hydrogen-iodide (HI) VLE and decomposition behavior in the iodine-sulfur (IS) cycle to improve the conventional I-S cycle suggested by GA. Neumann's modified NRTL model was improved by correcting an unphysical assumption for the non-randomness parameter, and using the two-step equilibrium approach for the HI decomposition modeling. However, the parameters of the model were decided through regression with the 271 sets of existing experimental data: the accuracy of the model should be improved by more experimental data over all operating ranges, especially, in the high temperature and high pressure regions. To obtain the data of those regions, an autoclave for high temperature and high pressure was designed and manufactured. Various materials and surface coating technologies were investigated for preventing corrosion from acids. However, we have currently failed to overcome the corrosion problems with highly corrosive acids at a high temperature and high pressure. We experimentally validated that azeotropic constraint between acid and H 2 O undermined the total efficiency of the I-S cycle. As mentioned above, the conventional I-S cycle suffers from low thermal efficiency and highly corrosive streams. To alleviate these problems, we have proposed the optimal operating conditions for the Bunsen reaction and devised a new KAIST flowsheet that produces highly enriched HI through spontaneous L-L phase separation and simple flash processes under low pressure. A series of phase separation experiments were performed to validate the new flowsheet and extend its feasibility. When the molar ratio of I 2 /H 2 SO 4 in the feed increased from 2 to 4, the molar ratio of HI/(HI+H 2 O) in the HI x phase improved from 0.157 to 0.22, which is high enough to generate

  12. Bimetallic catalysts for HI decomposition in the iodine-sulfur thermochemical cycle

    International Nuclear Information System (INIS)

    Wang Laijun; Hu Songzhi; Xu Lufei; Li Daocai; Han Qi; Chen Songzhe; Zhang Ping; Xu Jingming

    2014-01-01

    Among the different kinds of thermochemical water-splitting cycles, the iodine-sulfur (IS) cycle has attracted more and more interest because it is one of the promising candidates for economical and massive hydrogen production. However, there still exist some science and technical problems to be solved before industrialization of the IS process. One such problem is the catalytic decomposition of hydrogen iodide. Although the active carbon supported platinum has been verified to present the excellent performance for HI decomposition, it is very expensive and easy to agglomerate under the harsh condition. In order to decrease the cost and increase the stability of the catalysts for HI decomposition, a series of bimetallic catalysts were prepared and studied at INET. This paper summarized our present research advances on the bimetallic catalysts (Pt-Pd, Pd-Ir and Pt-Ir) for HI decomposition. In the course of the study, the physical properties, structure, and morphology of the catalysts were characterized by specific surface area, X-ray diffractometer; and transmission electron microscopy, respectively. The catalytic activity for HI decomposition was investigated in a fixed bed reactor under atmospheric pressure. The results show that due to the higher activity and better stability, the active carbon supported bimetallic catalyst is more potential candidate than mono metallic Pt catalyst for HI decomposition in the IS thermochemical cycle. (author)

  13. Hybrid Automotive Engine Using Ethanol-Burning Miller Cycle

    Science.gov (United States)

    Weinstein, Leonard

    2004-01-01

    A proposed hybrid (internal-combustion/ electric) automotive engine system would include as its internal-combustion subsystem, a modified Miller-cycle engine with regenerative air preheating and with autoignition like that of a Diesel engine. The fuel would be ethanol and would be burned lean to ensure complete combustion. Although the proposed engine would have a relatively low power-to-weight ratio compared to most present engines, this would not be the problem encountered if this engine were used in a non-hybrid system since hybrid systems require significantly lower power and thus smaller engines than purely internal-combustion-engine-driven vehicles. The disadvantage would be offset by the advantages of high fuel efficiency, low emission of nitrogen oxides and particulate pollutants, and the fact that ethanol is a renewable fuel. The original Miller-cycle engine, named after its inventor, was patented in the 1940s and is the basis of engines used in some modern automobiles, but is not widely known. In somewhat oversimplified terms, the main difference between a Miller-cycle engine and a common (Otto-cycle) automobile engine is that the Miller-cycle engine has a longer expansion stroke while retaining the shorter compression stroke. This is accomplished by leaving the intake valve open for part of the compression stroke, whereas in the Otto cycle engine, the intake valve is kept closed during the entire compression stroke. This greater expansion ratio makes it possible to extract more energy from the combustion process without expending more energy for compression. The net result is greater efficiency. In the proposed engine, the regenerative preheating would be effected by running the intake air through a heat exchanger connected to the engine block. The regenerative preheating would offer two advantages: It would ensure reliable autoignition during operation at low ambient temperature and would help to cool the engine, thereby reducing the remainder of the

  14. Analysis and optimal process development of the iodine-Sulfur cycle for nuclear hydrogen production

    International Nuclear Information System (INIS)

    Lee, Byung Jin

    2009-02-01

    Hydrogen is expected to be a main energy vector for the future society. Among many thermo-chemical water splitting technologies for mass production of hydrogen, Iodine-Sulfur (I-S) cycle is considered to be the most promising one. Originated in the 1980s by General Atomics in the United States, the I-S cycle utilizes high temperature heat from energy sources such as nuclear reactors. Despite its high viability relative to many other options, lots of technical challenges need to be resolved until it can practically contribute to the mass production of hydrogen. In the present work, based on the experimental data available from previous works and discussions collected through the literature survey, the optimal operating conditions were proposed for the Bunsen reaction, considering the key concerns of the I-S cycle: i.e., the liquid-liquid (L-L) phase separation performance, the water distributions between the sulfuric acid and poly-hydroiodic acid (HI x ) phases, the side reactions, and the operating cost due to the excess iodine and water. All the available experimental data were combined together, and a series of parametric studies were done to find out any trends among parameters. The optimal operating point is determined as 4 mol of excess iodine and 11 mol of excess water in the stoichiometry at temperature of 330K, while the allowable window ranges between 4∼6 mol for excess iodine, 11∼13 moles for excess water, and 330∼350K for temperature. As for the distribution of excess water after the Bunsen reaction and L-L phase separation, 5 mol moves to the sulfuric acid phase and 6∼8 mol to the HI x phase. By controlling the operation within this window, it should be possible to avoid the side reaction and iodine solidification, to increase the HI concentration well above the azeotrope in the HI x section, and to minimize the operating cost caused by the excess iodine and water. With the optimized Bunsen reaction process to yield an over-azeotropic HI liquid

  15. Sorting through the many total-energy-cycle pathways possible with early plug-in hybrids

    International Nuclear Information System (INIS)

    Gaines, L.; Burnham, A.; Rousseau, A.; Santini, D.

    2008-01-01

    Using the 'total energy cycle' methodology, we compare U.S. near term (to ∼2015) alternative pathways for converting energy to light-duty vehicle kilometers of travel (VKT) in plug-in hybrids (PHEVs), hybrids (HEVs), and conventional vehicles (CVs). For PHEVs, we present total energy-per-unit-of-VKT information two ways (1) energy from the grid during charge depletion (CD); (2) energy from stored on-board fossil fuel when charge sustaining (CS). We examine 'incremental sources of supply of liquid fuel such as (a) oil sands from Canada, (b) Fischer-Tropsch diesel via natural gas imported by LNG tanker, and (c) ethanol from cellulosic biomass. We compare such fuel pathways to various possible power converters producing electricity, including (i) new coal boilers, (ii) new integrated, gasified coal combined cycle (IGCC), (iii) existing natural gas fueled combined cycle (NGCC), (iv) existing natural gas combustion turbines, (v) wood-to-electricity, and (vi) wind/solar. We simulate a fuel cell HEV and also consider the possibility of a plug-in hybrid fuel cell vehicle (FCV). For the simulated FCV our results address the merits of converting some fuels to hydrogen to power the fuel cell vs. conversion of those same fuels to electricity to charge the PHEV battery. The investigation is confined to a U.S. compact sized car (i.e. a world passenger car). Where most other studies have focused on emissions (greenhouse gases and conventional air pollutants), this study focuses on identification of the pathway providing the most vehicle kilometers from each of five feedstocks examined. The GREET 1.7 fuel cycle model and the new GREET 2.7 vehicle cycle model were used as the foundation for this study. Total energy, energy by fuel type, total greenhouse gases (GHGs), volatile organic compounds (VOC), carbon monoxide (CO), nitrogen oxides (NO x ), fine particulate (PM2.5) and sulfur oxides (SO x ) values are presented. We also isolate the PHEV emissions contribution from varying k

  16. Microbial contributions to coupled arsenic and sulfur cycling in the acid-sulfide hot spring Champagne Pool, New Zealand

    Directory of Open Access Journals (Sweden)

    Katrin eHug

    2014-11-01

    Full Text Available Acid-sulfide hot springs are analogs of early Earth geothermal systems where microbial metal(loid resistance likely first evolved. Arsenic is a metalloid enriched in the acid-sulfide hot spring Champagne Pool (Waiotapu, New Zealand. Arsenic speciation in Champagne Pool follows reaction paths not yet fully understood with respect to biotic contributions and coupling to biogeochemical sulfur cycling. Here we present quantitative arsenic speciation from Champagne Pool, finding arsenite dominant in the pool, rim and outflow channel (55-75% total arsenic, and dithio- and trithioarsenates ubiquitously present as 18-25% total arsenic. In the outflow channel, dimethylmonothioarsenate comprised ≤9% total arsenic, while on the outflow terrace thioarsenates were present at 55% total arsenic. We also quantified sulfide, thiosulfate, sulfate and elemental sulfur, finding sulfide and sulfate as major species in the pool and outflow terrace, respectively. Elemental sulfur reached a maximum at the terrace. Phylogenetic analysis of 16S rRNA genes from metagenomic sequencing revealed the dominance of Sulfurihydrogenibium at all sites and an increased archaeal population at the rim and outflow channel. Several phylotypes were found closely related to known sulfur- and sulfide-oxidizers, as well as sulfur- and sulfate-reducers. Bioinformatic analysis revealed genes underpinning sulfur redox transformations, consistent with sulfur speciation data, and illustrating a microbial role in sulfur-dependent transformation of arsenite to thioarsenate. Metagenomic analysis also revealed genes encoding for arsenate reductase at all sites, reflecting the ubiquity of thioarsenate and a need for microbial arsenate resistance despite anoxic conditions. Absence of the arsenite oxidase gene, aio, at all sites suggests prioritization of arsenite detoxification over coupling to energy conservation. Finally, detection of methyl arsenic in the outflow channel, in conjunction with

  17. Performance Analysis of Hybrid Electric Vehicle over Different Driving Cycles

    Science.gov (United States)

    Panday, Aishwarya; Bansal, Hari Om

    2017-02-01

    Article aims to find the nature and response of a hybrid vehicle on various standard driving cycles. Road profile parameters play an important role in determining the fuel efficiency. Typical parameters of road profile can be reduced to a useful smaller set using principal component analysis and independent component analysis. Resultant data set obtained after size reduction may result in more appropriate and important parameter cluster. With reduced parameter set fuel economies over various driving cycles, are ranked using TOPSIS and VIKOR multi-criteria decision making methods. The ranking trend is then compared with the fuel economies achieved after driving the vehicle over respective roads. Control strategy responsible for power split is optimized using genetic algorithm. 1RC battery model and modified SOC estimation method are considered for the simulation and improved results compared with the default are obtained.

  18. Biogeochemical cycling of arsenic in coastal salinized aquifers: Evidence from sulfur isotope study

    International Nuclear Information System (INIS)

    Kao, Yu-Hsuan; Wang, Sheng-Wei; Liu, Chen-Wuing; Wang, Pei-Ling; Wang, Chung-Ho; Maji, Sanjoy Kumar

    2011-01-01

    Arsenic (As) contamination of groundwater, accompanied by critical salinization, occurs in the southwestern coastal area of Taiwan. Statistical analyses and geochemical calculations indicate that a possible source of aqueous arsenic is the reductive dissolution of As-bearing iron oxyhydroxides. There are few reports of the influence of sulfate-sulfide redox cycling on arsenic mobility in brackish groundwater. We evaluated the contribution of sulfate reduction and sulfide re-oxidation on As enrichment using δ 34 S [SO 4 ] and δ 18 O [SO 4 ] sulfur isotopic analyses of groundwater. Fifty-three groundwater samples were divided into groups of high-As content and salinized (Type A), low-As and non-salinized (Type B), and high-As and non-salinized (Type C) groundwaters, based on hydro-geochemical analysis. The relatively high enrichment of 34 S [SO 4 ] and 18 O [SO 4 ] present in Type A, caused by microbial-mediated reduction of sulfate, and high 18 O enrichment factor (ε [SO 4 -H 2 O] ), suggests that sulfur disproportionation is an important process during the reductive dissolution of As-containing iron oxyhydroxides. Limited co-precipitation of ion-sulfide increased the rate of As liberation under anaerobic conditions. In contrast to this, Type B and Type C groundwater samples showed high δ 18 O [SO 4 ] and low δ 34 S [SO 4 ] values under mildly reducing conditions. Base on 18 O mass balance calculations, the oxide sources of sulfate are from infiltrated atmospheric O 2 , caused by additional recharge of dissolved oxygen and sulfide re-oxidation. The anthropogenic influence of extensive pumping also promotes atmospheric oxygen entry into aquifers, altering redox conditions, and increasing the rate of As release into groundwater. - Highlights: → Seawater intrusion and elevated As are the main issues of groundwater in Taiwan. → Sulfur and oxygen isotopes of sulfate were analyzed to evaluate the As mobility. → Reductive dissolution of Fe minerals and

  19. Biogeochemical cycling of arsenic in coastal salinized aquifers: Evidence from sulfur isotope study

    Energy Technology Data Exchange (ETDEWEB)

    Kao, Yu-Hsuan [Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei 106, Taiwan, ROC (China); Wang, Sheng-Wei [Agricultural Engineering Research Center, Chungli 320, Taiwan, ROC (China); Liu, Chen-Wuing, E-mail: lcw@gwater.agec.ntu.edu.tw [Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei 106, Taiwan, ROC (China); Wang, Pei-Ling [Institute of Oceanography, National Taiwan University, Taipei 106, Taiwan, ROC (China); Wang, Chung-Ho [Institute of Earth Sciences, Academia Sinica, Taipei 115, Taiwan, ROC (China); Maji, Sanjoy Kumar [Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei 106, Taiwan, ROC (China)

    2011-10-15

    Arsenic (As) contamination of groundwater, accompanied by critical salinization, occurs in the southwestern coastal area of Taiwan. Statistical analyses and geochemical calculations indicate that a possible source of aqueous arsenic is the reductive dissolution of As-bearing iron oxyhydroxides. There are few reports of the influence of sulfate-sulfide redox cycling on arsenic mobility in brackish groundwater. We evaluated the contribution of sulfate reduction and sulfide re-oxidation on As enrichment using {delta}{sup 34}S{sub [SO{sub 4]}} and {delta}{sup 18}O{sub [SO{sub 4]}} sulfur isotopic analyses of groundwater. Fifty-three groundwater samples were divided into groups of high-As content and salinized (Type A), low-As and non-salinized (Type B), and high-As and non-salinized (Type C) groundwaters, based on hydro-geochemical analysis. The relatively high enrichment of {sup 34}S{sub [SO{sub 4]}} and {sup 18}O{sub [SO{sub 4]}} present in Type A, caused by microbial-mediated reduction of sulfate, and high {sup 18}O enrichment factor ({epsilon}{sub [SO{sub 4-H{sub 2O]}}}), suggests that sulfur disproportionation is an important process during the reductive dissolution of As-containing iron oxyhydroxides. Limited co-precipitation of ion-sulfide increased the rate of As liberation under anaerobic conditions. In contrast to this, Type B and Type C groundwater samples showed high {delta}{sup 18}O{sub [SO{sub 4]}} and low {delta}{sup 34}S{sub [SO{sub 4]}} values under mildly reducing conditions. Base on {sup 18}O mass balance calculations, the oxide sources of sulfate are from infiltrated atmospheric O{sub 2}, caused by additional recharge of dissolved oxygen and sulfide re-oxidation. The anthropogenic influence of extensive pumping also promotes atmospheric oxygen entry into aquifers, altering redox conditions, and increasing the rate of As release into groundwater. - Highlights: {yields} Seawater intrusion and elevated As are the main issues of groundwater in Taiwan

  20. Assessing the potential of hybrid fossil–solar thermal plants for energy policy making: Brayton cycles

    International Nuclear Information System (INIS)

    Bernardos, Eva; López, Ignacio; Rodríguez, Javier; Abánades, Alberto

    2013-01-01

    This paper proposes a first study in-depth of solar–fossil hybridization from a general perspective. It develops a set of useful parameters for analyzing and comparing hybrid plants, it studies the case of hybridizing Brayton cycles with current solar technologies and shows a tentative extrapolation of the results to integrated combined cycle systems (ISCSS). In particular, three points have been analyzed: the technical requirements for solar technologies to be hybridized with Brayton cycles, the temperatures and pressures at which hybridization would produce maximum power per unit of fossil fuel, and their mapping to current solar technologies and Brayton cycles. Major conclusions are that a hybrid plant works in optimum conditions which are not equal to those of the solar or power blocks considered independently, and that hybridizing at the Brayton cycle of a combined cycle could be energetically advantageous. -- Highlights: •We model a generic solar–fossil hybrid Brayton cycle. •We calculate the operating conditions for maximum ratio power/fuel consumption. •Best hybrid plant conditions are not the same as solar or power blocks separately. •We study potential for hybridization with current solar technologies. •Hybridization at the Brayton in a combined cycle may achieve high power/fuel ratio

  1. Significantly enhanced electrochemical performance of lithium titanate anode for lithium ion battery by the hybrid of nitrogen and sulfur co-doped graphene quantum dots

    International Nuclear Information System (INIS)

    Ruiyi, Li; Yuanyuan, Jiang; Xiaoyan, Zhou; Zaijun, Li; Zhiguo, Gu; Guangli, Wang; Junkang, Liu

    2015-01-01

    Graphical abstract: The study reported a facile synthesis of Li4Ti5O12/nitrogen and sulfur co-doped graphene quantum dots (LTO/N,S-GQDs). The unique architecture and the introduction of N,S-GQDs create both ultrafast electron transfer and electrolyte transport. The as-prepared LTO/N,S-GQDs anode provides prominent advantage of specific capacity, high-rate performance and cycle stability. - Highlights: • We reported a new lithium titanate/nitrogen and sulfur co-doped graphene quantum dots hybrid • The synthesis creates a crystalline interconnected porous framework composed of nanoscale LTO • The unique architecture achieves to maximize the rate performance and enhance the power density • Introduction of N,S-GQDs greatly enhances the electron transfer and the storage lithium capacity • The hybrid anode provides an excellent electrochemical performance for lithium-ion batteries - ABSTRACT: The paper reported a facile synthesis of lithium titanate/nitrogen and sulfur co-doped graphene quantum dots(LTO/N,S-GQDs). Tetrabutyl titanate was dissolved in tertbutanol and heated to refluxing state by microwave irradiation. Then, lithium acetate was added into the mixed solution to produce LTO precursor. The precursor was hybridized with N,S-GQDs in ethanol. Followed by drying and thermal annealing at 500 °C in Ar/H_2 to obtain LTO/N,S-GQDs. The synthesis creates fully crystalline interconnected porous framework composed of nanoscale LTO crystals. The unique architecture achieves to maximize the high-rate performance and enhance the power density. More importantly, the introduction of N,S-GQDs don't almost influence on the electrolyte transport, but greatly improve the electron transfer and the storage lithium capacity. The LTO/N,S-GQDs anode exhibits remarkably enhanced electrochemical performance for lithium ion battery. The specific discharge capacity is 254.2 mAh g"−"1 at 0.1C and 126.5 mAh g"−"1 at 10C. The capacity remains 96.9% at least after 2000 cycles

  2. Microbial Character Related Sulfur Cycle under Dynamic Environmental Factors Based on the Microbial Population Analysis in Sewerage System.

    Science.gov (United States)

    Dong, Qian; Shi, Hanchang; Liu, Yanchen

    2017-01-01

    The undesired sulfur cycle derived by microbial population can ultimately causes the serious problems of sewerage systems. However, the microbial community characters under dynamic environment factors in actual sewerage system is still not enough. This current study aimed to character the distributions and compositions of microbial communities that participate in the sulfur cycle under the dynamic environmental conditions in a local sewerage system. To accomplish this, microbial community compositions were assessed using 454 high-throughput sequencing (16S rDNA) combined with dsrB gene-based denaturing gradient gel electrophoresis. The results indicated that a higher diversity of microbial species was present at locations in sewers with high concentrations of H 2 S. Actinobacteria and Proteobacteria were dominant in the sewerage system, while Actinobacteria alone were dominant in regions with high concentrations of H 2 S. Specifically, the unique operational taxonomic units could aid to characterize the distinct microbial communities within a sewerage manhole. The proportion of sulfate-reducing bacteria, each sulfur-oxidizing bacteria (SOB) were strongly correlated with the liquid parameters (DO, ORP, COD, Sulfide, NH 3 -N), while the Mycobacterium and Acidophilic SOB (M&A) was strongly correlated with gaseous factors within the sewer, such as H 2 S, CH 4 , and CO. Identifying the distributions and proportions of critical microbial communities within sewerage systems could provide insights into how the microbial sulfur cycle is affected by the dynamic environmental conditions that exist in sewers and might be useful for explaining the potential sewerage problems.

  3. Novel Graphene-Gold Hybrid Nanostructures Constructed via Sulfur Modified Graphene: Preparation and Characterization by Surface and Electrochemical Techniques

    International Nuclear Information System (INIS)

    Shervedani, Reza Karimi; Amini, Akbar

    2014-01-01

    Graphical abstract: Graphene nanosheet-gold nanoparticles (GNs-AuNPs) hybrid has been fabricated from sulfur-modified graphene nanosheets (S-GNs) impregnated with HAuCl4 as Au precursor. Application of the GNs-AuNPs hybrid in electrochemical biosensing was demonstrated by immobilization of glucose oxidase as a model on the surface of GCE-ATP-GNs-AuNPs, and then, using it for sensing of glucose. - Highlights: • A new hybrid of GNs-AuNPs is synthesized by using sulfur-modified graphene. • Stability of the hybrid is exceptionally improved in comparison with previous works. • Aminothiophenol mediated fabrication and stabilization of GNs-AuNPs on GCE electrode. • High electrocatalytic activity was observed for O 2 reduction by hybrid. • Activity of the hybrid was originated from synergistic effect and surface roughness. - Abstract: A novel and uniform graphene nanosheet-gold nanoparticles (GNs-AuNPs) hybrid has been fabricated from sulfur-modified graphene nanosheets (S-GNs) impregnated with HAuCl 4 as Au precursor. Physicochemical and morphological characteristics of the GNs-AuNPs hybrids were investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), surface Raman spectroscopy (SRS), and high resolution transmission electron microscopy (HRTEM). The results of the XRD and HRTEM demonstrated well dispersed Au nanoparticles on GNs with an average particle size of less than 10 nm and a narrow size distribution of 6 to 8 nm. A film of GNs-AuNPs hybrid was constructed on a glassy carbon electrode (GCE) through layer-by-layer (LBL) assembly of 4-aminothiphenol (ATP) on GCE, and then, transferring the hybrid to the sulfur function of ATP to form GCE-ATP-GNs-AuNPs modified surface. Application of the GNs-AuNPs hybrid in electrochemical biosensing was demonstrated by immobilization of glucose oxidase (GOx) as a model on the surface of GCE-ATP-GNs-AuNPs, and then, using it for sensing of glucose. The biosensor exhibited a wide linear response

  4. Iron Sulfur and Molybdenum Cofactor Enzymes Regulate the Drosophila Life Cycle by Controlling Cell Metabolism

    Science.gov (United States)

    Marelja, Zvonimir; Leimkühler, Silke; Missirlis, Fanis

    2018-01-01

    Iron sulfur (Fe-S) clusters and the molybdenum cofactor (Moco) are present at enzyme sites, where the active metal facilitates electron transfer. Such enzyme systems are soluble in the mitochondrial matrix, cytosol and nucleus, or embedded in the inner mitochondrial membrane, but virtually absent from the cell secretory pathway. They are of ancient evolutionary origin supporting respiration, DNA replication, transcription, translation, the biosynthesis of steroids, heme, catabolism of purines, hydroxylation of xenobiotics, and cellular sulfur metabolism. Here, Fe-S cluster and Moco biosynthesis in Drosophila melanogaster is reviewed and the multiple biochemical and physiological functions of known Fe-S and Moco enzymes are described. We show that RNA interference of Mocs3 disrupts Moco biosynthesis and the circadian clock. Fe-S-dependent mitochondrial respiration is discussed in the context of germ line and somatic development, stem cell differentiation and aging. The subcellular compartmentalization of the Fe-S and Moco assembly machinery components and their connections to iron sensing mechanisms and intermediary metabolism are emphasized. A biochemically active Fe-S core complex of heterologously expressed fly Nfs1, Isd11, IscU, and human frataxin is presented. Based on the recent demonstration that copper displaces the Fe-S cluster of yeast and human ferredoxin, an explanation for why high dietary copper leads to cytoplasmic iron deficiency in flies is proposed. Another proposal that exosomes contribute to the transport of xanthine dehydrogenase from peripheral tissues to the eye pigment cells is put forward, where the Vps16a subunit of the HOPS complex may have a specialized role in concentrating this enzyme within pigment granules. Finally, we formulate a hypothesis that (i) mitochondrial superoxide mobilizes iron from the Fe-S clusters in aconitase and succinate dehydrogenase; (ii) increased iron transiently displaces manganese on superoxide dismutase, which

  5. Iron Sulfur and Molybdenum Cofactor Enzymes Regulate the Drosophila Life Cycle by Controlling Cell Metabolism

    Directory of Open Access Journals (Sweden)

    Zvonimir Marelja

    2018-02-01

    Full Text Available Iron sulfur (Fe-S clusters and the molybdenum cofactor (Moco are present at enzyme sites, where the active metal facilitates electron transfer. Such enzyme systems are soluble in the mitochondrial matrix, cytosol and nucleus, or embedded in the inner mitochondrial membrane, but virtually absent from the cell secretory pathway. They are of ancient evolutionary origin supporting respiration, DNA replication, transcription, translation, the biosynthesis of steroids, heme, catabolism of purines, hydroxylation of xenobiotics, and cellular sulfur metabolism. Here, Fe-S cluster and Moco biosynthesis in Drosophila melanogaster is reviewed and the multiple biochemical and physiological functions of known Fe-S and Moco enzymes are described. We show that RNA interference of Mocs3 disrupts Moco biosynthesis and the circadian clock. Fe-S-dependent mitochondrial respiration is discussed in the context of germ line and somatic development, stem cell differentiation and aging. The subcellular compartmentalization of the Fe-S and Moco assembly machinery components and their connections to iron sensing mechanisms and intermediary metabolism are emphasized. A biochemically active Fe-S core complex of heterologously expressed fly Nfs1, Isd11, IscU, and human frataxin is presented. Based on the recent demonstration that copper displaces the Fe-S cluster of yeast and human ferredoxin, an explanation for why high dietary copper leads to cytoplasmic iron deficiency in flies is proposed. Another proposal that exosomes contribute to the transport of xanthine dehydrogenase from peripheral tissues to the eye pigment cells is put forward, where the Vps16a subunit of the HOPS complex may have a specialized role in concentrating this enzyme within pigment granules. Finally, we formulate a hypothesis that (i mitochondrial superoxide mobilizes iron from the Fe-S clusters in aconitase and succinate dehydrogenase; (ii increased iron transiently displaces manganese on superoxide

  6. Stable isotope phenotyping via cluster analysis of NanoSIMS data as a method for characterizing distinct microbial ecophysiologies and sulfur-cycling in the environment

    Directory of Open Access Journals (Sweden)

    Katherine S Dawson

    2016-05-01

    Full Text Available Stable isotope probing (SIP is a valuable tool for gaining insights into ecophysiology and biogeochemical cycling of environmental microbial communities by tracking isotopically labeled compounds into cellular macromolecules as well as into byproducts of respiration. SIP, in conjunction with nanoscale secondary ion mass spectrometry (NanoSIMS, allows for the visualization of isotope incorporation at the single cell level. In this manner, both active cells within a diverse population as well as heterogeneity in metabolism within a homogeneous population can be observed. The ecophysiological implications of these single cell stable isotope measurements are often limited to the taxonomic resolution of paired fluorescence in situ hybridization (FISH microscopy. Here we introduce a taxonomy-independent method using multi-isotope SIP and NanoSIMS for identifying and grouping phenotypically similar microbial cells by their chemical and isotopic fingerprint. This method was applied to SIP experiments in a sulfur-cycling biofilm collected from sulfidic intertidal vents amended with 13C-acetate, 15N-ammonium, and 33S-sulfate. Using a cluster analysis technique based on fuzzy c-means to group cells according to their isotope (13C/12C, 15N/14N, and 33S/32S and elemental ratio (C/CN and S/CN profiles, our analysis partitioned ~2200 cellular regions of interest (ROIs into 5 distinct groups. These isotope phenotype groupings are reflective of the variation in labeled substrate uptake by cells in a multispecies metabolic network dominated by Gamma- and Deltaproteobacteria. Populations independently grouped by isotope phenotype were subsequently compared with paired FISH data, demonstrating a single coherent deltaproteobacterial cluster and multiple gammaproteobacterial groups, highlighting the distinct ecophysiologies of spatially-associated microbes within the sulfur-cycling biofilm from White Point Beach, CA.

  7. Simulated effects of sulfur deposition on nutrient cycling in class I wilderness areas

    Science.gov (United States)

    Katherine J. Elliott; James M. Vose; Jennifer D. Knoepp; Dale W. Johnson; William T. Swank; William Jackson

    2008-01-01

    As a consequence of human land use, population growth, and industrialization, wilderness and other natural areas can be threatened by air pollution, climate change, and exotic diseases or pests. Air pollution in the form of acidic deposition is comprised of sulfuric and nitric acids and ammonium derived from emissions of sulfur dioxide, nitrogen oxides, and ammonia....

  8. Sulfur Cycling in an Iron Oxide-Dominated, Dynamic Marine Depositional System: The Argentine Continental Margin

    Directory of Open Access Journals (Sweden)

    Natascha Riedinger

    2017-05-01

    Full Text Available The interplay between sediment deposition patterns, organic matter type and the quantity and quality of reactive mineral phases determines the accumulation, speciation, and isotope composition of pore water and solid phase sulfur constituents in marine sediments. Here, we present the sulfur geochemistry of siliciclastic sediments from two sites along the Argentine continental slope—a system characterized by dynamic deposition and reworking, which result in non-steady state conditions. The two investigated sites have different depositional histories but have in common that reactive iron phases are abundant and that organic matter is refractory—conditions that result in low organoclastic sulfate reduction rates (SRR. Deposition of reworked, isotopically light pyrite and sulfurized organic matter appear to be important contributors to the sulfur inventory, with only minor addition of pyrite from organoclastic sulfate reduction above the sulfate-methane transition (SMT. Pore-water sulfide is limited to a narrow zone at the SMT. The core of that zone is dominated by pyrite accumulation. Iron monosulfide and elemental sulfur accumulate above and below this zone. Iron monosulfide precipitation is driven by the reaction of low amounts of hydrogen sulfide with ferrous iron and is in competition with the oxidation of sulfide by iron (oxyhydroxides to form elemental sulfur. The intervals marked by precipitation of intermediate sulfur phases at the margin of the zone with free sulfide are bordered by two distinct peaks in total organic sulfur (TOS. Organic matter sulfurization appears to precede pyrite formation in the iron-dominated margins of the sulfide zone, potentially linked to the presence of polysulfides formed by reaction between dissolved sulfide and elemental sulfur. Thus, SMTs can be hotspots for organic matter sulfurization in sulfide-limited, reactive iron-rich marine sedimentary systems. Furthermore, existence of elemental sulfur and iron

  9. Hierarchical N-Rich Carbon Sponge with Excellent Cycling Performance for Lithium-Sulfur Battery at High Rates.

    Science.gov (United States)

    Zhen, Mengmeng; Wang, Juan; Wang, Xin; Wang, Cheng

    2018-04-17

    Lithium-sulfur batteries (LSBs) are receiving extensive attention because of their high theoretical energy density. However, practical applications of LSBs are still hindered by their rapid capacity decay and short cycle life, especially at high rates. Herein, a highly N-doped (≈13.42 at %) hierarchical carbon sponge (HNCS) with strong chemical adsorption for lithium polysulfide is fabricated through a simple sol-gel route followed by carbonization. Upon using the HNCS as the sulfur host material in the cathode and an HNCS-coated separator, the battery delivers an excellent cycling stability with high specific capacities of 424 and 326 mA h g -1 and low capacity fading rates of 0.033 % and 0.030 % per cycle after 1000 cycles under high rates of 5 and 10 C, respectively, which are superior to those of other reported carbonaceous materials. These impressive cycling performances indicate that such a battery could promote the practical application prospects of LSBs. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Diversity of sulfur-cycle prokaryotes in freshwater lake sediments investigated using aprA as the functional marker gene.

    Science.gov (United States)

    Watanabe, Tomohiro; Kojima, Hisaya; Takano, Yoshinori; Fukui, Manabu

    2013-09-01

    The diversity of sulfate-reducing prokaryotes (SRPs) and sulfur-oxidizing prokaryotes (SOPs) in freshwater lake ecosystems was investigated by cloning and sequencing of the aprA gene, which encodes for a key enzyme in dissimilatory sulfate reduction and sulfur oxidation. To understand their diversity better, the spatial distribution of aprA genes was investigated in sediments collected from six geographically distant lakes in Antarctica and Japan, including a hypersaline lake for comparison. The microbial community compositions of freshwater sediments and a hypersaline sediment showed notable differences. The clones affiliated with Desulfobacteraceae and Desulfobulbaceae were frequently detected in all freshwater lake sediments. The SOP community was mainly composed of four major phylogenetic groups. One of them formed a monophyletic cluster with a sulfur-oxidizing betaproteobacterium, Sulfuricella denitrificans, but the others were not assigned to specific genera. In addition, the AprA sequences, which were not clearly affiliated to either SRP or SOP lineages, dominated the libraries from four freshwater lake sediments. The results showed the wide distribution of some sulfur-cycle prokaryotes across geographical distances and supported the idea that metabolic flexibility is an important feature for SRP survival in low-sulfate environments. Copyright © 2013 Elsevier GmbH. All rights reserved.

  11. Particulate sulfur-containing lipids: Production and cycling from the epipelagic to the abyssopelagic zone

    Science.gov (United States)

    Gašparović, Blaženka; Penezić, Abra; Frka, Sanja; Kazazić, Saša; Lampitt, Richard S.; Holguin, F. Omar; Sudasinghe, Nilusha; Schaub, Tanner

    2018-04-01

    There are major gaps in our understanding of the distribution and role of lipids in the open ocean especially with regard to sulfur-containing lipids (S-lipids). Here, we employ a powerful analytical approach based on high resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) to elucidate depth-related S-lipid production and molecular transformations in suspended particulate matter from the Northeast Atlantic Ocean in this depth range. We show that within the open-ocean environment S-lipids contribute up to 4.2% of the particulate organic carbon, and that up to 95% of these compounds have elemental compositions that do not match those found in the Nature Lipidomics Gateway database (termed "novel"). Among the remaining 5% of lipids that match the database, we find that sulphoquinovosyldiacylglycerol (SQDG) are efficiently removed while sinking through the mesopelagic zone. The relative abundance of other assigned lipids (sulphoquinovosylmonoacylglycerol (SQMG), sulfite and sulfate lipids, Vitamin D2 and D3 derivatives, and sphingolipids) did not change substantially with depth. The novel S-lipids, represented by hundreds of distinct elemental compositions (160-300 molecules at any one depth), contribute increasingly to the lipid and particulate organic matter pools with increased depth. Depth-related transformations cause (i) incomplete degradation/transformation of unsaturated S-lipids which leads to the depth-related accumulation of the refractory saturated compounds with reduced molecular weight (average 455 Da) and (ii) formation of highly unsaturated S-lipids (average abyssopelagic molecular double bond equivalents, DBE=7.8) with lower molecular weight (average 567 Da) than surface S-lipids (average 592 Da). A depth-related increase in molecular oxygen content is observed for all novel S-lipids and indicates that oxidation has a significant role in their transformation while (bio)hydrogenation possibly impacts the formation of

  12. Ultimate refrigerating conditions, behavior turning and a thermodynamic analysis for absorption–compression hybrid refrigeration cycle

    International Nuclear Information System (INIS)

    Zheng Danxing; Meng Xuelin

    2012-01-01

    Highlights: ► Two novel fundamental concepts of the absorption refrigeration cycle were proposed. ► The interaction mechanism of compressor pressure increasing with other key-parameters was investigated. ► A set of optimal operating condition of hybrid refrigeration cycle was found. ► A simulation and investigation for R134a-DMF hybrid refrigeration cycle was performed. - Abstract: The absorption–compression hybrid refrigeration cycle has been considered as an effective approach to reduce the mechanical work consumption by using low-grade heat, such as solar energy. This work aims at studying the thermodynamic mechanism of the hybrid refrigeration cycle. Two fundamental concepts have been proposed, which are the ultimate refrigerating temperature (or the ultimate temperature lift) and the behavior turning. On the basis of that, the interaction mechanism of compressor pressure increasing with other key-parameters and the impact of compressor pressure increasing on the cycle performance have been investigated. The key-parameters include the concentration difference, the circulation ratio of working fluid, etc. The work points out that the hybrid refrigeration cycle performance varies with the change of compressor outlet pressure and depends on which one achieves dominance in the hybrid refrigeration cycle, the absorption sub-system or the compression sub-system. The behavior turning point during parameters changing corresponds to a maximum value of the heat powered coefficient of performance. In this case, the hybrid refrigeration cycle performance is optimal because the low-grade heat utilization is the most effective. In addition, to validate the theoretical analysis, a solar hybrid refrigeration cycle with R134a–DMF as working pair was simulated. The Peng–Robinson equation of state was adopted to calculate thermophysical properties when the reliability assessment of the prediction models on the available literature data of R134a–DMF system had been

  13. Superior supercapacitors based on nitrogen and sulfur co-doped hierarchical porous carbon: Excellent rate capability and cycle stability

    Science.gov (United States)

    Zhang, Deyi; Han, Mei; Wang, Bing; Li, Yubing; Lei, Longyan; Wang, Kunjie; Wang, Yi; Zhang, Liang; Feng, Huixia

    2017-08-01

    Vastly improving the charge storage capability of supercapacitors without sacrificing their high power density and cycle performance would bring bright application prospect. Herein, we report a nitrogen and sulfur co-doped hierarchical porous carbon (NSHPC) with very superior capacitance performance fabricated by KOH activation of nitrogen and sulfur co-doped ordered mesoporous carbon (NSOMC). A high electrochemical double-layer (EDL) capacitance of 351 F g-1 was observed for the reported NSHPC electrodes, and the capacitance remains at 288 F g-1 even under a large current density of 20 A g-1. Besides the high specific capacitance and outstanding rate capability, symmetrical supercapacitor cell based on the NSHPC electrodes also exhibits an excellent cycling performance with 95.61% capacitance retention after 5000 times charge/discharge cycles. The large surface area caused by KOH activation (2056 m2 g-1) and high utilized surface area owing to the ideal micro/mesopores ratio (2.88), large micropores diameter (1.38 nm) and short opened micropores structure as well as the enhanced surface wettability induced by N and S heteroatoms doping and improved conductivity induced by KOH activation was found to be responsible for the very superior capacitance performance.

  14. Simultaneous nitrogen and phosphorus removal in the sulfur cycle-associated Enhanced Biological Phosphorus Removal (EBPR) process.

    Science.gov (United States)

    Wu, Di; Ekama, George A; Wang, Hai-Guang; Wei, Li; Lu, Hui; Chui, Ho-Kwong; Liu, Wen-Tso; Brdjanovic, Damir; van Loosdrecht, Mark C M; Chen, Guang-Hao

    2014-02-01

    Hong Kong has practiced seawater toilet flushing since 1958, saving 750,000 m(3) of freshwater every day. A high sulfate-to-COD ratio (>1.25 mg SO4(2-)/mg COD) in the saline sewage resulting from this practice has enabled us to develop the Sulfate reduction, Autotrophic denitrification and Nitrification Integrated (SANI(®)) process with minimal sludge production and oxygen demand. Recently, the SANI(®) process has been expanded to include Enhanced Biological Phosphorus Removal (EBPR) in an alternating anaerobic/limited-oxygen (LOS-EBPR) aerobic sequencing batch reactor (SBR). This paper presents further development - an anaerobic/anoxic denitrifying sulfur cycle-associated EBPR, named as DS-EBPR, bioprocess in an alternating anaerobic/anoxic SBR for simultaneous removal of organics, nitrogen and phosphorus. The 211 day SBR operation confirmed the sulfur cycle-associated biological phosphorus uptake utilizing nitrate as electron acceptor. This new bioprocess cannot only reduce operation time but also enhance volumetric loading of SBR compared with the LOS-EBPR. The DS-EBPR process performed well at high temperatures of 30 °C and a high salinity of 20% seawater. A synergistic relationship may exist between sulfur cycle and biological phosphorus removal as the optimal ratio of P-release to SO4(2-)-reduction is close to 1.0 mg P/mg S. There were no conventional PAOs in the sludge. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Sulfur amino acid deficiency upregulates intestinal methionine cycle activity and suppresses epithelial growth in neonatal pigs.

    Science.gov (United States)

    We recently showed that the developing gut is a significant site of methionine transmethylation to homocysteine and transsulfuration to cysteine. We hypothesized that sulfur amino acid (SAA) deficiency would preferentially reduce mucosal growth and antioxidant function in neonatal pigs. Neonatal pi...

  16. Effects of aerobic-anaerobic transient conditions on sulfur and metal cycles in sewer biofilms

    NARCIS (Netherlands)

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

    2005-01-01

    Interactions between sulfur and metals were studied in aerobic and anaerobic biofilms grown on domestic waste water at 15°C. The dominant metals in the waste water were iron, zinc and copper, which were present in average concentrations of 0.5mg/l, 0.6mg/l and 0.1m/l, respectively. Copper and zinc

  17. Application of bacteria involved in the biological sulfur cycle for paper mill effluent purification

    NARCIS (Netherlands)

    Janssen, A.J.H.; Lens, P.N.L.; Stams, A.J.M.; Plugge, C.M.; Sorokin, D.Y.; Muyzer, G.; Dijkman, H.; Zessen, van E.; Luimes, F.J.T.; Buisman, C.J.N.

    2009-01-01

    In anaerobic wastewater treatment, the occurrence of biological sulfate reduction results in the formation of unwanted hydrogen sulfide, which is odorous, corrosive and toxic. In this paper, the role and application of bacteria in anaerobic and aerobic sulfur transformations are described and

  18. Economics analysis of fuel cycle cost of fusion–fission hybrid reactors based on different fuel cycle strategies

    Energy Technology Data Exchange (ETDEWEB)

    Zu, Tiejun, E-mail: tiejun@mail.xjtu.edu.cn; Wu, Hongchun; Zheng, Youqi; Cao, Liangzhi

    2015-01-15

    Highlights: • Economics analysis of fuel cycle cost of FFHRs is carried out. • The mass flows of different fuel cycle strategies are established based on the equilibrium fuel cycle model. • The levelized fuel cycle costs of different fuel cycle strategies are calculated, and compared with current once-through fuel cycle. - Abstract: The economics analysis of fuel cycle cost of fusion–fission hybrid reactors has been performed to compare four fuel cycle strategies: light water cooled blanket burning natural uranium (Strategy A) or spent nuclear fuel (Strategy B), sodium cooled blanket burning transuranics (Strategy C) or minor actinides (Strategy D). The levelized fuel cycle costs (LFCC) which does not include the capital cost, operation and maintenance cost have been calculated based on the equilibrium mass flows. The current once-through (OT) cycle strategy has also been analyzed to serve as the reference fuel cycle for comparisons. It is found that Strategy A and Strategy B have lower LFCCs than OT cycle; although the LFCC of Strategy C is higher than that of OT cycle when the uranium price is at its nominal value, it would become comparable to that of OT cycle when the uranium price reaches its historical peak value level; Strategy D shows the highest LFCC, because it needs to reprocess huge mass of spent nuclear fuel; LFCC is sensitive to the discharge burnup of the nuclear fuel.

  19. Internet Enabled Remote Driving of a Combat Hybrid Electric Power System for Duty Cycle Measurement

    National Research Council Canada - National Science Library

    Goodell, Jarrett; Compere, Marc; Smith, Wilford; Holtz, Dale; Brudnak, Mark; Pozolo, Mike; Paul, Victor; Mohammad, Syed; Mortsfield, Todd; Shvartsman, Andrey

    2007-01-01

    This paper describes a human-in-the-loop motion-based simulator interfaced to hybrid-electric power system hardware, both of which were used to measure the duty cycle of a combat vehicle in a virtual...

  20. Combined cycle solar central receiver hybrid power system study. Volume III. Appendices. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-11-01

    A design study for a 100 MW gas turbine/steam turbine combined cycle solar/fossil-fuel hybrid power plant is presented. This volume contains the appendices: (a) preconceptual design data; (b) market potential analysis methodology; (c) parametric analysis methodology; (d) EPGS systems description; (e) commercial-scale solar hybrid power system assessment; and (f) conceptual design data lists. (WHK)

  1. Modeling and observational constraints on the sulfur cycle in the marine troposphere: a focus on reactive halogens and multiphase chemistry

    Science.gov (United States)

    Chen, Q.; Breider, T.; Schmidt, J.; Sherwen, T.; Evans, M. J.; Xie, Z.; Quinn, P.; Bates, T. S.; Alexander, B.

    2017-12-01

    The radiative forcing from marine boundary layer clouds is still highly uncertain, which partly stems from our poor understanding of cloud condensation nuclei (CCN) formation. The oxidation of dimethyl sulfide (DMS) and subsequent chemical evolution of its products (e.g. DMSO) are key processes in CCN formation, but are generally very simplified in large-scale models. Recent research has pointed out the importance of reactive halogens (e.g. BrO and Cl) and multiphase chemistry in the tropospheric sulfur cycle. In this study, we implement a series of sulfur oxidation mechanisms into the GEOS-Chem global chemical transport model, involving both gas-phase and multiphase oxidation of DMS, DMSO, MSIA and MSA, to improve our understanding of the sulfur cycle in the marine troposphere. DMS observations from six locations around the globe and MSA/nssSO42- ratio observations from two ship cruises covering a wide range of latitudes and longitudes are used to assess the model. Preliminary results reveal the important role of BrO for DMS oxidation at high latitudes (up to 50% over Southern Ocean). Oxidation of DMS by Cl radicals is small in the model (within 10% in the marine troposphere), probably due to an underrepresentation of Cl sources. Multiphase chemistry (e.g. oxidation by OH and O3 in cloud droplets) is not important for DMS oxidation but is critical for DMSO oxidation and MSA production and removal. In our model, about half of the DMSO is oxidized in clouds, leading to the formation of MSIA, which is further oxidized to form MSA. Overall, with the addition of reactive halogens and multiphase chemistry, the model is able to better reproduce observations of seasonal variations of DMS and MSA/nssSO42- ratios.

  2. A model-based insight into the coupling of nitrogen and sulfur cycles in a coastal upwelling system

    DEFF Research Database (Denmark)

    Muchamad, Al Azhar; Canfield, Donald Eugene; Fennel, Katja

    2014-01-01

    is masked, however, by rapid sulfide oxidation, most likely through nitrate reduction. Thus, the cryptic sulfur cycle links with the nitrogen cycle in OMZ settings. Here, we model the physical-chemical water column structure and the observed process rates as driven by formation and sinking of organic...... heterotrophic nitrate reduction and sulfate reduction are responsible for 47% and 36%, respectively, of organic remineralization in a 150 m deep zone below mixed layer. Anammox contributes to 61% of the fixed nitrogen lost to N2 gas, while the rest of the loss is through canonical denitrification...... as a combination of organic matter oxidation by nitrite reduction and sulfide-driven denitrification. Mineralization coupled to heterotrophic nitrate reduction supplies ~48% of the ammonium required by anammox. Due to active sulfate reduction, model results suggest that sulfide-driven denitrification contributes...

  3. Electrolyte for stable cycling of high-energy lithium sulfur redox flow batteries

    Science.gov (United States)

    Xiao, Jie; Liu, Jun; Pan, Huilin; Henderson, Wesley A.

    2018-04-24

    A device comprising: a lithium sulfur redox flow battery comprising an electrolyte composition comprising: (i) a dissolved Li2Sx electroactive salt, wherein x.gtoreq.4; (ii) a solvent selected from dimethyl sulfoxide, tetrahydrofuran, or a mixture thereof; and (iii) a supporting salt at a concentration of at least 2 M, as measured by moles of supporting salt divided by the volume of the solvent without considering the volume change of the electrolyte after dissolving the supporting salt.

  4. Recent developments in thermally-driven seawater desalination: Energy efficiency improvement by hybridization of the MED and AD cycles

    KAUST Repository

    Ng, Kim Choon; Thu, Kyaw; Oh, Seungjin; Ang, Li; Shahzad, Muhammad Wakil; Ismail, Azhar Bin

    2015-01-01

    -driven to adsorption desalination (AD) cycles where significant thermodynamic synergy can be attained when cycles are combined. For these hybrid cycles, a quantum improvement in energy efficiency as well as in increase in water production can be expected. The advent

  5. A hybrid multi-effect distillation and adsorption cycle

    KAUST Repository

    Thu, Kyaw; Kim, Youngdeuk; Amy, Gary L.; Chun, Wongee; Ng, K. C.

    2013-01-01

    cycle, there is a symbiotic enhancement of performances of both cycles. The performance enhancement is attributed to (i) the cascade of adsorbent's regeneration temperature and this extended the usage of thermal energy emanating from the brine heater

  6. Environmental, health, and safety issues of sodium-sulfur batteries for electric and hybrid vehicles. Volume 1, Cell and battery safety

    Energy Technology Data Exchange (ETDEWEB)

    Ohi, J M

    1992-09-01

    This report is the first of four volumes that identify and assess the environmental, health, and safety issues involved in using sodium-sulfur (Na/S) battery technology as the energy source in electric and hybrid vehicles that may affect the commercialization of Na/S batteries. This and the other reports on recycling, shipping, and vehicle safety are intended to help the Electric and Hybrid Propulsion Division of the Office of Transportation Technologies in the US Department of Energy (DOE/EHP) determine the direction of its research, development, and demonstration (RD&D) program for Na/S battery technology. The reports review the status of Na/S battery RD&D and identify potential hazards and risks that may require additional research or that may affect the design and use of Na/S batteries. This volume covers cell design and engineering as the basis of safety for Na/S batteries and describes and assesses the potential chemical, electrical, and thermal hazards and risks of Na/S cells and batteries as well as the RD&D performed, under way, or to address these hazards and risks. The report is based on a review of the literature and on discussions with experts at DOE, national laboratories and agencies, universities, and private industry. Subsequent volumes will address environmental, health, and safety issues involved in shipping cells and batteries, using batteries to propel electric vehicles, and recycling and disposing of spent batteries. The remainder of this volume is divided into two major sections on safety at the cell and battery levels. The section on Na/S cells describes major component and potential failure modes, design, life testing and failure testing, thermal cycling, and the safety status of Na/S cells. The section on batteries describes battery design, testing, and safety status. Additional EH&S information on Na/S batteries is provided in the appendices.

  7. Identification of sulfur-cycle prokaryotes in a low-sulfate lake (Lake Pavin) using aprA and 16S rRNA gene markers.

    Science.gov (United States)

    Biderre-Petit, Corinne; Boucher, Delphine; Kuever, Jan; Alberic, Patrick; Jézéquel, Didier; Chebance, Brigitte; Borrel, Guillaume; Fonty, Gérard; Peyret, Pierre

    2011-02-01

    Geochemical researches at Lake Pavin, a low-sulfate-containing freshwater lake, suggest that the dominant biogeochemical processes are iron and sulfate reduction, and methanogenesis. Although the sulfur cycle is one of the main active element cycles in this lake, little is known about the sulfate-reducer and sulfur-oxidizing bacteria. The aim of this study was to assess the vertical distribution of these microbes and their diversities and to test the hypothesis suggesting that only few SRP populations are involved in dissimilatory sulfate reduction and that Epsilonproteobacteria are the likely key players in the oxidative phase of sulfur cycle by using a PCR aprA gene-based approach in comparison with a 16S rRNA gene-based analysis. The results support this hypothesis. Finally, this preliminary work points strongly the likelihood of novel metabolic processes upon the availability of sulfate and other electron acceptors.

  8. Electrolyte for stable cycling of high-energy lithium sulfur redox flow batteries

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Jie; Liu, Jun; Pan, Huilin; Henderson, Wesley A.

    2018-04-24

    A device comprising: a lithium sulfur redox flow battery comprising an electrolyte composition comprising: (i) a dissolved Li2Sx electroactive salt, wherein x.gtoreq.4; (ii) a solvent selected from dimethyl sulfoxide, tetrahydrofuran, or a mixture thereof; and (iii) a supporting salt at a concentration of at least 2 M, as measured by moles of supporting salt divided by the volume of the solvent without considering the volume change of the electrolyte after dissolving the supporting salt.

  9. Strong Capillarity, Chemisorption, and Electrocatalytic Capability of Crisscrossed Nanostraws Enabled Flexible, High-Rate, and Long-Cycling Lithium-Sulfur Batteries.

    Science.gov (United States)

    Ma, Lianbo; Zhang, Wenjun; Wang, Lei; Hu, Yi; Zhu, Guoyin; Wang, Yanrong; Chen, Renpeng; Chen, Tao; Tie, Zuoxiu; Liu, Jie; Jin, Zhong

    2018-05-22

    The development of flexible lithium-sulfur (Li-S) batteries with high energy density and long cycling life are very appealing for the emerging flexible, portable, and wearable electronics. However, the progress on flexible Li-S batteries was limited by the poor flexibility and serious performance decay of existing sulfur composite cathodes. Herein, we report a freestanding and highly flexible sulfur host that can simultaneously meet the flexibility, stability, and capacity requirements of flexible Li-S batteries. The host consists of a crisscrossed network of carbon nanotubes reinforced CoS nanostraws (CNTs/CoS-NSs). The CNTs/CoS-NSs with large inner space and high conductivity enable high loading and efficient utilization of sulfur. The strong capillarity effect and chemisorption of CNTs/CoS-NSs to sulfur species were verified, which can efficiently suppress the shuttle effect and promote the redox kinetics of polysulfides. The sulfur-encapsulated CNTs/CoS-NSs (S@CNTs/CoS-NSs) cathode in Li-S batteries exhibits superior performance, including high discharge capacity, rate capability (1045 mAh g -1 at 0.5 C and 573 mAh g -1 at 5.0 C), and cycling stability. Intriguingly, the soft-packed Li-S batteries based on S@CNTs/CoS-NSs cathode show good flexibility and stability upon bending.

  10. Identification of the algal dimethyl sulfide-releasing enzyme: A missing link in the marine sulfur cycle

    Science.gov (United States)

    Alcolombri, Uria; Ben-Dor, Shifra; Feldmesser, Ester; Levin, Yishai; Tawfik, Dan S.; Vardi, Assaf

    2015-06-01

    Algal blooms produce large amounts of dimethyl sulfide (DMS), a volatile with a diverse signaling role in marine food webs that is emitted to the atmosphere, where it can affect cloud formation. The algal enzymes responsible for forming DMS from dimethylsulfoniopropionate (DMSP) remain unidentified despite their critical role in the global sulfur cycle. We identified and characterized Alma1, a DMSP lyase from the bloom-forming algae Emiliania huxleyi. Alma1 is a tetrameric, redox-sensitive enzyme of the aspartate racemase superfamily. Recombinant Alma1 exhibits biochemical features identical to the DMSP lyase in E. huxleyi, and DMS released by various E. huxleyi isolates correlates with their Alma1 levels. Sequence homology searches suggest that Alma1 represents a gene family present in major, globally distributed phytoplankton taxa and in other marine organisms.

  11. Comparison of Optimal Thermodynamic Models of the Tricarboxylic Acid Cycle from Heterotrophs, Cyanobacteria, and Green Sulfur Bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Dennis G.; Jaramillo Riveri, Sebastian I.; Baxter, Douglas J.; Cannon, William R.

    2014-12-15

    We have applied a new stochastic simulation approach to predict the metabolite levels, energy flow, and material flux in the different oxidative TCA cycles found in E. coli and Synechococcus sp. PCC 7002, and in the reductive TCA cycle typical of chemolithoautotrophs and phototrophic green sulfur bacteria such as Chlorobaculum tepidum. The simulation approach is based on equations of state and employs an assumption similar to that used in transition state theory. The ability to evaluate the thermodynamics of metabolic pathways allows one to understand the relationship between coupling of energy and material gradients in the environment and the selforganization of stable biological systems, and it is shown that each cycle operates in the direction expected due to its environmental niche. The simulations predict changes in metabolite levels and flux in response to changes in cofactor concentrations that would be hard to predict without an elaborate model based on the law of mass action. In fact, we show that a thermodynamically unfavorable reaction can still have flux in the forward direction when it is part of a reaction network. The ability to predict metabolite levels, energy flow and material flux should be significant for understanding the dynamics of natural systems and for understanding principles for engineering organisms for production of specialty chemicals, such as biofuels.

  12. Comparison of Optimal Thermodynamic Models of the Tricarboxylic Acid Cycle from Heterotrophs, Cyanobacteria, and Green Sulfur Bacteria.

    Science.gov (United States)

    Thomas, Dennis G; Jaramillo-Riveri, Sebastian; Baxter, Douglas J; Cannon, William R

    2014-12-26

    We have applied a new stochastic simulation approach to predict the metabolite levels, material flux, and thermodynamic profiles of the oxidative TCA cycles found in E. coli and Synechococcus sp. PCC 7002, and in the reductive TCA cycle typical of chemolithoautotrophs and phototrophic green sulfur bacteria such as Chlorobaculum tepidum. The simulation approach is based on modeling states using statistical thermodynamics and employs an assumption similar to that used in transition state theory. The ability to evaluate the thermodynamics of metabolic pathways allows one to understand the relationship between coupling of energy and material gradients in the environment and the self-organization of stable biological systems, and it is shown that each cycle operates in the direction expected due to its environmental niche. The simulations predict changes in metabolite levels and flux in response to changes in cofactor concentrations that would be hard to predict without an elaborate model based on the law of mass action. In fact, we show that a thermodynamically unfavorable reaction can still have flux in the forward direction when it is part of a reaction network. The ability to predict metabolite levels, energy flow, and material flux should be significant for understanding the dynamics of natural systems and for understanding principles for engineering organisms for production of specialty chemicals.

  13. Deposition and cycling of sulfur controls mercury accumulation in Isle Royale fish

    Energy Technology Data Exchange (ETDEWEB)

    Paul E. Drevnick; Donald E. Canfield; Patrick R. Gorski (and others) [Miami University, Oxford, OH (United States). Department of Zoology

    2007-11-01

    Mercury contamination of fish is a global problem. Consumption of contaminated fish is the primary route of methylmercury exposure in humans and is detrimental to health. Newly mandated reductions in anthropogenic mercury emissions aim to reduce atmospheric mercury deposition and thus mercury concentrations in fish. However, factors other than mercury deposition are important for mercury bioaccumulation in fish. In the lakes of Isle Royale, U.S.A., reduced rates of sulfate deposition since the Clean Air Act of 1970 have caused mercury concentrations in fish to decline to levels that are safe for human consumption, even without a discernible decrease in mercury deposition. Therefore, reductions in anthropogenic sulfur emissions may provide a synergistic solution to the mercury problem in sulfate-limited freshwaters. 71 refs., 3 figs., 1 tab.

  14. Sulfur and Iron Cycling in a Coastal Sediment - Radiotracer Studies and Seasonal Dynamics

    DEFF Research Database (Denmark)

    MOESLUND, L.; THAMDRUP, B.; JØRGENSEN, BB

    1994-01-01

    The seasonal variation in sulfate reduction and the dynamics of sulfur and iron geochemistry were studied throughout a year in sediment of Aarhus Bay, Denmark. A radiotracer method for measuring sulfate reduction rates was applied with incubation times down to 15 min and a depth resolution down...... to 2 mm in the oxidized surface layer of the sediment. The radiotracer data were analyzed by a mathematical model which showed that, due to partial, rapid reoxidation of radioactive sulfide during incubation, the actual reduction rates in this layer were probably underestimated 5-fold. In the deeper......, sulfidic zone, measured rates appeared to be correct. Sulfate reduction followed the seasonal variation in temperature with maximum activity at 1-2 cm depth in late summer. In spite of its rapid production, free H2S was detectable in the porewater only below the depth of free Fe2+ at 6-7 cm throughout...

  15. Investigation on thiosulfate-involved organics and nitrogen removal by a sulfur cycle-based biological wastewater treatment process.

    Science.gov (United States)

    Qian, Jin; Lu, Hui; Cui, Yanxiang; Wei, Li; Liu, Rulong; Chen, Guang-Hao

    2015-02-01

    Thiosulfate, as an intermediate of biological sulfate/sulfite reduction, can significantly improve nitrogen removal potential in a biological sulfur cycle-based process, namely the Sulfate reduction-Autotrophic denitrification-Nitrification Integrated (SANI(®)) process. However, the related thiosulfate bio-activities coupled with organics and nitrogen removal in wastewater treatment lacked detailed examinations and reports. In this study, S2O3(2-) transformation during biological SO4(2-)/SO3(2-) co-reduction coupled with organics removal as well as S2O3(2-) oxidation coupled with chemolithotrophic denitrification were extensively evaluated under different experimental conditions. Thiosulfate is produced from the co-reduction of sulfate and sulfite through biological pathway at an optimum pH of 7.5 for organics removal. And the produced S2O3(2-) may disproportionate to sulfide and sulfate during both biological S2O3(2-) reduction and oxidation most possibly carried out by Desulfovibrio-like species. Dosing the same amount of nitrate, pH was found to be the more direct factor influencing the denitritation activity than free nitrous acid (FNA) and the optimal pH for denitratation (7.0) and denitritation (8.0) activities were different. Spiking organics significantly improved both denitratation and denitritation activities while minimizing sulfide inhibition of NO3(-) reduction during thiosulfate-based denitrification. These findings in this study can improve the understanding of mechanisms of thiosulfate on organics and nitrogen removal in biological sulfur cycle-based wastewater treatment. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. A Cryptic Sulfur Cycle in Oxygen-Minimum-Zone Waters off the Chilean Coast

    OpenAIRE

    Canfield, D. E.; Thamdrup, B.; De Brabandere, L.; Dalsgaard, T.; Revsbech, N. P.; Ulloa, O.; Stewart, Frank J.; DeLong, Edward Francis

    2010-01-01

    Nitrogen cycling is normally thought to dominate the biogeochemistry and microbial ecology of oxygen-minimum zones in marine environments. Through a combination of molecular techniques and process rate measurements, we showed that both sulfate reduction and sulfide oxidation contribute to energy flux and elemental cycling in oxygen-free waters off the coast of northern Chile. These processes may have been overlooked because in nature, the sulfide produced by sulfate reduction immediately oxid...

  17. Integrating a Photocatalyst into a Hybrid Lithium-Sulfur Battery for Direct Storage of Solar Energy.

    Science.gov (United States)

    Li, Na; Wang, Yarong; Tang, Daiming; Zhou, Haoshen

    2015-08-03

    Direct capture and storage of abundant but intermittent solar energy in electrical energy-storage devices such as rechargeable lithium batteries is of great importance, and could provide a promising solution to the challenges of energy shortage and environment pollution. Here we report a new prototype of a solar-driven chargeable lithium-sulfur (Li-S) battery, in which the capture and storage of solar energy was realized by oxidizing S(2-) ions to polysulfide ions in aqueous solution with a Pt-modified CdS photocatalyst. The battery can deliver a specific capacity of 792 mAh g(-1) during 2 h photocharging process with a discharge potential of around 2.53 V versus Li(+)/Li. A specific capacity of 199 mAh g(-1), reaching the level of conventional lithium-ion batteries, can be achieved within 10 min photocharging. Moreover, the charging process of the battery can proceed under natural sunlight irradiation. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Analysis of the hybrid copper oxide-copper sulfate cycle for the thermochemical splitting of water for hydrogen production

    International Nuclear Information System (INIS)

    Gonzales, Ross B.; Law, Victor J.; Prindle, John C.

    2009-01-01

    The hybrid copper oxide-copper sulfate water-splitting thermochemical cycle involves two principal steps: (1) hydrogen production from the electrolysis of water, SO 2 (g) and CuO(s) at room temperature and (2) the thermal decomposition of the CuSO 4 product to form oxygen and SO 2 , which is recycled to the first step. A four-reaction version of the cycle (known in the literature as Cycle H-5) was used as the basis of the present work. For several of the four reactions, a rotating batch reactor sequence is proposed in order to overcome equilibrium limitations. Pinch technology was used to optimize heat integration. Sensitivity analyses revealed it to be economically more attractive to use a 10 C approach to minimize heat loss (rather than 20 C). Using standard Aspen Plus features and the Peng-Robinson equation of state for separations involving oxygen and sulfur oxides, a proposed flowsheet for the cycle was generated to yield ''Level 3'' results. A cost analysis of the designed plant (producing 100 million kmol/yr hydrogen) indicates a total major equipment cost of approximately $45 million. This translates to a turnkey plant price (excluding the cost of the high-temperature heat source or electrolyzer internals) of approximately $360 million. Based on a $2.50/kg selling price for hydrogen, gross annual revenue could be on the order of $500 million, resulting in a reasonable payback period when all capital and operating costs are considered. Previous efficiency estimates using Level 1 and Level 2 methods gave the process efficiency in the neighborhood of 47-48%. The Level 3 efficiency computation was 24-25% depending on the approach temperature used for recuperation. If the low quality heat rejected by the process can be recovered and used elsewhere, the Level 3 analysis could be as high as 51-53%. (author)

  19. Simulation of global sulfate distribution and the influence of effective cloud drop radii with a coupled photochemistry-sulfur cycle model

    NARCIS (Netherlands)

    Roelofs, G.J.; Lelieveld, J.; Ganzeveld, L.N.

    1998-01-01

    A sulfur cycle model is coupled to a global chemistry-climate model. The simulated surface sulfate concentrations are generally within a factor of 2 of observed concentrations, and display a realistic seasonality for most background locations. However, the model tends to underestimate sulfate and

  20. Combined cycle solar central receiver hybrid power system study. Final technical report. Volume II

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-11-01

    This study develops the conceptual design for a commercial-scale (nominal 100 MWe) central receiver solar/fossil fuel hybrid power system with combined cycle energy conversion. A near-term, metallic heat pipe receiver and an advanced ceramic tube receiver hybrid system are defined through parametric and market potential analyses. Comparative evaluations of the cost of power generation, the fuel displacement potential, and the technological readiness of these two systems indicate that the near-term hybrid system has better potential for commercialization by 1990. Based on the assessment of the conceptual design, major cost and performance improvements are projected for the near-term system. Constraints preventing wide-spread use were not identified. Energy storage is not required for this system and analyses show no economic advantages with energy storage provisions. It is concluded that the solar hybrid system is a cost effective alternative to conventional gas turbines and combined cycle generating plants, and has potential for intermediate-load market penetration at 15% annual fuel escalation rate. Due to their flexibility, simple solar/nonsolar interfacing, and short startup cycles, these hybrid plants have significant operating advantages. Utility company comments suggest that hybrid power systems will precede stand-alone solar plants.

  1. The role of iron-sulfides on cycling of organic carbon in the St Lawrence River system: Evidence of sulfur-promoted carbon sequestration?

    Science.gov (United States)

    Balind, K.; Barber, A.; Gélinas, Y.

    2017-12-01

    The biogeochemical cycle of sulfur is intimately linked with that of carbon, as well as with that of iron through the formation of iron-sulfur complexes. Iron-sulfide minerals such as mackinawite (FeS) and greigite (Fe3S4) form below the oxic/anoxic redox boundary in marine and lacustrine sediments and soils. Reactive iron species, abundant in surface sediments, can undergo reductive dissolution leading to the formation of soluble Fe(II) which can then precipitate in the form of iron sulfur species. While sedimentary iron-oxides have been thoroughly explored in terms of their ability to sorb and sequester organic carbon (OC) (Lalonde et al.; 2012), the role of FeS in the long-term preservation of OC remains undefined. In this study, we present depth profiles for carbon, iron, and sulfur in the aqueous-phase, along with data from sequential extractions of sulfur speciation in the solid-phase collected from sediment cores from the St Lawrence River and estuarine system, demonstrating the transition from fresh to saltwater sediments. Additionally, we present synthetic iron sulfur sorption experiments using both model and natural organic molecules in order to assess the importance of FeS in sedimentary carbon storage.

  2. Research on Fuel Consumption of Hybrid Bulldozer under Typical Duty Cycle

    Science.gov (United States)

    Song, Qiang; Wang, Wen-Jun; Jia, Chao; Yao, You-Liang; Wang, Sheng-Bo

    The hybrid drive bulldozer adopts a dual-motor independent drive system with engine-generator assembly as its power source. The mathematical model of the whole system is constructed on the software platform of MATLAB/Simulink. And then according to the velocity data gained from a real test experiment, a typical duty cycle is build up. Finally the fuel consumption of the bulldozer is calculated under this duty-cycle. Simulation results show that, compared with the traditional mechanical one, the hybrid electric drive system can save fuel up to 16% and therefore indicates great potential for lifting up fuel economy.

  3. Application of bacteria involved in the biological sulfur cycle for paper mill effluent purification

    International Nuclear Information System (INIS)

    Janssen, Albert J.H.; Lens, Piet N.L.; Stams, Alfons J.M.; Plugge, Caroline M.; Sorokin, Dimitri Y.; Muyzer, Gerard; Dijkman, Henk; Van Zessen, Erik; Luimes, Peter; Buisman, Cees J.N.

    2009-01-01

    In anaerobic wastewater treatment, the occurrence of biological sulfate reduction results in the formation of unwanted hydrogen sulfide, which is odorous, corrosive and toxic. In this paper, the role and application of bacteria in anaerobic and aerobic sulfur transformations are described and exemplified for the treatment of a paper mill wastewater. The sulfate containing wastewater first passes an anaerobic UASB reactor for bulk COD removal which is accompanied by the formation of biogas and hydrogen sulfide. In an aeration pond, the residual COD organic and the formed dissolved hydrogen sulfide are removed. The biogas, consisting of CH 4 (80-90 vol.%), CO 2 (10-20 vol.%) and H 2 S (0.8-1.2 vol.%), is desulfurised prior to its combustion in a power generator thereby using a new biological process for H 2 S removal. This process will be described in more detail in this paper. Biomass from the anaerobic bioreactor has a compact granular structure and contains a diverse microbial community. Therefore, other anaerobic bioreactors throughout the world are inoculated with biomass from this UASB reactor. The sludge was also successfully used in investigation on sulfate reduction with carbon monoxide as the electron donor and the conversion of methanethiol. This shows the biotechnological potential of this complex reactor biomass

  4. Application of bacteria involved in the biological sulfur cycle for paper mill effluent purification

    Energy Technology Data Exchange (ETDEWEB)

    Janssen, Albert J.H. [Sub-department of Environmental Technology, Wageningen University, Wageningen (Netherlands); Shell Global Solutions Int. B.V., Amsterdam (Netherlands)], E-mail: albert.janssen@wur.nl; Lens, Piet N.L. [Sub-department of Environmental Technology, Wageningen University, Wageningen (Netherlands); Stams, Alfons J.M.; Plugge, Caroline M. [Laboratory of Microbiology, Wageningen University, Wageningen (Netherlands); Sorokin, Dimitri Y. [Department of Biotechnology, Delft (Netherlands); Institute of Microbiology, Russian Academy of Science, Moscow (Russian Federation); Muyzer, Gerard [Department of Biotechnology, Delft (Netherlands); Dijkman, Henk; Van Zessen, Erik [Paques B.V., Balk (Netherlands); Luimes, Peter [Industriewater Eerbeek B.V. Eerbeek (Netherlands); Buisman, Cees J.N. [Sub-department of Environmental Technology, Wageningen University, Wageningen (Netherlands)

    2009-02-01

    In anaerobic wastewater treatment, the occurrence of biological sulfate reduction results in the formation of unwanted hydrogen sulfide, which is odorous, corrosive and toxic. In this paper, the role and application of bacteria in anaerobic and aerobic sulfur transformations are described and exemplified for the treatment of a paper mill wastewater. The sulfate containing wastewater first passes an anaerobic UASB reactor for bulk COD removal which is accompanied by the formation of biogas and hydrogen sulfide. In an aeration pond, the residual COD{sub organic} and the formed dissolved hydrogen sulfide are removed. The biogas, consisting of CH{sub 4} (80-90 vol.%), CO{sub 2} (10-20 vol.%) and H{sub 2}S (0.8-1.2 vol.%), is desulfurised prior to its combustion in a power generator thereby using a new biological process for H{sub 2}S removal. This process will be described in more detail in this paper. Biomass from the anaerobic bioreactor has a compact granular structure and contains a diverse microbial community. Therefore, other anaerobic bioreactors throughout the world are inoculated with biomass from this UASB reactor. The sludge was also successfully used in investigation on sulfate reduction with carbon monoxide as the electron donor and the conversion of methanethiol. This shows the biotechnological potential of this complex reactor biomass.

  5. Archaea, Bacteria, and Sulfur-Cycling in a Shallow-Sea Hydrothermal Ecosystem

    Science.gov (United States)

    Amend, J. P.; Huang, C.; Amann, R.; Bach, W.; Meyerdierks, A.; Price, R. E.; Schubotz, F.; Summons, R. E.; Wenzhoefer, F.

    2009-12-01

    Deep-sea hydrothermal systems are windows to the marine subsurface biosphere. It often is overlooked, however, that their far more accessible shallow-sea counterparts can serve the same purpose. To characterize the extent, diversity, and activity of the subsurface microbial community in the shallow vent ecosystem near Panarea Island (Italy), sediment cores were analyzed with a broad array of analytical techniques. Vent fluid and sediment temperatures reached up to 135 °C, with pHs in porewaters generally measuring 5-6. Microsensor profiles marked a very sharp oxic-anoxic transition, and when coupled to pH and H2S profiles, pointed to aerobic sulfide oxidation. With increasing depth from the sediment-water interface, porewater analyses showed a decrease in sulfate levels from ~30 mM to thermophilic sulfate reducing and acidophilic sulfide oxidizing bacteria. Results from several sites also showed that with increasing depth and temperature, biomass abundance of archaea generally increased relative to that of bacteria. Lastly, DGGE fingerprinting and 16S rRNA clone libraries from several depths at Hot Lake revealed a moderate diversity of bacteria, dominated by Epsilonproteobacteria; this class is known to catalyze both sulfur reduction and oxidation reactions, and to mediate the formation of iron-sulfides, including framboidal pyrite. Archaeal sequences at Hot Lake are dominated by uncultured Thermoplasmatales, plus several sequences in the Korarchaeota.

  6. Environmental, health, and safety issues of sodium-sulfur batteries for electric and hybrid vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Corbus, D.

    1992-09-01

    Recycling and disposal of spent sodium-sulfur (Na/S) batteries are important issues that must be addressed as part of the commercialization process of Na/S battery-powered electric vehicles. The use of Na/S batteries in electric vehicles will result in significant environmental benefits, and the disposal of spent batteries should not detract from those benefits. In the United States, waste disposal is regulated under the Resource Conservation and Recovery Act (RCRA). Understanding these regulations will help in selecting recycling and disposal processes for Na/S batteries that are environmentally acceptable and cost effective. Treatment processes for spent Na/S battery wastes are in the beginning stages of development, so a final evaluation of the impact of RCRA regulations on these treatment processes is not possible. The objectives of tills report on battery recycling and disposal are as follows: Provide an overview of RCRA regulations and requirements as they apply to Na/S battery recycling and disposal so that battery developers can understand what is required of them to comply with these regulations; Analyze existing RCRA regulations for recycling and disposal and anticipated trends in these regulations and perform a preliminary regulatory analysis for potential battery disposal and recycling processes. This report assumes that long-term Na/S battery disposal processes will be capable of handling large quantities of spent batteries. The term disposal includes treatment processes that may incorporate recycling of battery constituents. The environmental regulations analyzed in this report are limited to US regulations. This report gives an overview of RCRA and discusses RCRA regulations governing Na/S battery disposal and a preliminary regulatory analysis for Na/S battery disposal.

  7. Technoeconomy of different solid oxide fuel cell based hybrid cycle

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2014-01-01

    Gas turbine, steam turbine and heat engine (Stirling engine) is used as bottoming cycle for a solid oxide fuel cell plant to compare different plants efficiencies, CO2 emissionsand plants cost in terms of $/kW. Each plant is then integrated with biomass gasification and finally six plants...

  8. Performance analysis of hybrid solid oxide fuel cell and gas turbine cycle: Application of alternative fuels

    International Nuclear Information System (INIS)

    Zabihian, Farshid; Fung, Alan S.

    2013-01-01

    Highlights: • Variation of the stream properties in the syngas-fueled hybrid SOFC–GT cycle. • Detailed analysis of the operation of the methane-fueled SOFC–GT cycle. • Investigate effects of inlet fuel type and composition on performance of cycle. • Comparison of system operation when operated with and without anode recirculation. - Abstract: In this paper, the hybrid solid oxide fuel cell (SOFC) and gas turbine (GT) model was applied to investigate the effects of the inlet fuel type and composition on the performance of the cycle. This type of analysis is vital for the real world utilization of manufactured fuels in the hybrid SOFC–GT system due to the fact that these fuel compositions depends on the type of material that is processed, the fuel production process, and process control parameters. In the first part of this paper, it is shown that the results of a limited number of studies on the utilization of non-conventional fuels have been published in the open literature. However, further studies are required in this area to investigate all aspects of the issue for different configurations and assumptions. Then, the results of the simulation of the syngas-fueled hybrid SOFC–GT cycle are employed to explain the variation of the stream properties throughout the cycle. This analysis can be very helpful in understanding cycle internal working and can provide some interesting insights to the system operation. Then, the detailed information of the operation of the methane-fueled SOFC–GT cycle is presented. For both syngas- and methane-fueled cycles, the operating conditions of the equipment are presented and compared. Moreover, the comparison of the characteristics of the system when it is operated with two different schemes to provide the required steam for the cycle, with anode recirculation and with an external source of water, provides some interesting insights to the system operation. For instance, it was shown that although the physical

  9. The Sulfur Cycle of Fresh-Water Sediments - Role of Thiosulfate

    DEFF Research Database (Denmark)

    JØRGENSEN, BB

    1990-01-01

    of the oxidized sulfide was ultimately converte into SO4(2-) and half was recycled back to sulfide via S2O3(2-). Two-thirds of the S in the sulfide-thiosulfate "minicycle" remained at an oxidation state of -2. S2O3(2-) is thus a key intermediate in the S cycle, both as a main product of anoxic sulfide oxidation...

  10. Hydrogen production system based on high temperature gas cooled reactor energy using the sulfur-iodine (SI) thermochemical water splitting cycle

    International Nuclear Information System (INIS)

    Garcia, L.; Gonzalez, D.

    2011-01-01

    Hydrogen production from water using nuclear energy offers one of the most attractive zero-emission energy strategies and the only one that is practical on a substantial scale. Recently, strong interest is seen in hydrogen production using heat of a high-temperature gas-cooled reactor. The high-temperature characteristics of the modular helium reactor (MHR) make it a strong candidate for producing hydrogen using thermochemical or high-temperature electrolysis (HTE) processes. Eventually it could be also employ a high-temperature gas-cooled reactor (HTGR), which is particularly attractive because it has unique capability, among potential future generation nuclear power options, to produce high-temperature heat ideally suited for nuclear-heated hydrogen production. Using heat from nuclear reactors to drive a sulfur-iodine (SI) thermochemical hydrogen production process has been interest of many laboratories in the world. One of the promising approaches to produce large quantity of hydrogen in an efficient way using the nuclear energy is the sulfur-iodine (SI) thermochemical water splitting cycle. Among the thermochemical cycles, the sulfur iodine process remains a very promising solution in matter of efficiency and cost. This work provides a pre-conceptual design description of a SI-Based H2-Nuclear Reactor plant. Software based on chemical process simulation (CPS) was used to simulate the thermochemical water splitting cycle Sulfur-Iodine for hydrogen production. (Author)

  11. Standard GAX versus hybrid GAX absorption refrigeration cycle: From the view point of thermoeconomics

    International Nuclear Information System (INIS)

    Mehr, A.S.; Zare, V.; Mahmoudi, S.M.S.

    2013-01-01

    Highlights: • The SGAX cycle is found to be thermoeconomically efficient compared to HGAX cycle. • The HGAX cycle has higher COP and exergy efficiency compared to SGAX cycle. • Minimum product cost is found 180.5 $/GJ and 159.1 $/GJ for HGAX and SGAX, respectively. - Abstract: The main goal of this research is to compare thermoeconomic performance of a GAX absorption cycle and a hybrid GAX absorption cycle in which a compressor is employed to raise the absorber pressure. In order to do this, the ammonia–water standard GAX (SGAX) and hybrid GAX (HGAX) absorption refrigeration cycles are investigated and optimized from the viewpoints of thermodynamics and economics. Parametric studies are carried out and with the help of genetic algorithm (GA), the cycles’ performance is optimized based on the COP and exergy efficiency as well as the cost of unit product. Results indicate that although, compared to the GAX cycle, the HGAX cycle demonstrates a better performance from the view points of both the first and second laws of thermodynamics, the unit product cost for the HGAX cycle is higher. At the optimum operating conditions, the cost of unit product for the HGAX cycle is calculated as 180.5 $/GJ while the corresponding value for the SGAX cycle is obtained as 159.1 $/GJ. Also, the exergoeconomic analyses unfold that the condenser has the lowest exergoeconomic factor, f, in both the systems. In addition, inspired from nature, a new graphical plot is proposed to illustrate the fuel cost, product cost, capital investment and operating and maintenance cost and cost rates associated with the exergy destruction and losses within the system’s components

  12. Manganese, Iron, and Sulfur Cycling in a Coastal Marine Sediment, Aarhus Bay, Denmark

    DEFF Research Database (Denmark)

    THAMDRUP, B.; FOSSING, H.; JØRGENSEN, BB

    1994-01-01

    -scale measurements showed that it extended to the upper 0-2.5 mm during summer, when the zones of Mn and Fe reduction were compressed towards the surface. Most of the H2S produced precipitated as iron sulfides and S0 by reaction with Fe. Both Fe(III) and a nonsulfur-bound authigenic Fe(II) pool reacted efficiently...... of a diatom spring bloom caused distinct maxima in SRR and Mn2+ at 0.5-1 cm depth within two weeks. In autumn, the reactive Mn oxides were depleted due to a net release of Mn2+ to the water column. Thus, the Mn cycle extended significantly into the water column, while a constant Fe pool over the year suggests...

  13. Electrocatalytic activity of lithium polysulfides adsorbed into porous TiO2 coated MWCNTs hybrid structure for lithium-sulfur batteries

    Science.gov (United States)

    He, Xiulin; Hou, Huijie; Yuan, Xiqing; Huang, Long; Hu, Jingping; Liu, Bingchuan; Xu, Jingyi; Xie, Jia; Yang, Jiakuan; Liang, Sha; Wu, Xu

    2017-01-01

    Lithium-sulfur batteries have attracted great attention because of their high energy density, environmental friendliness, natural abundance and intrinsically low cost of sulfur. However, their commercial applications are greatly hindered by rapid capacity decay due to poor conductivity of electrode, fast dissolution of the intermediate polysulfides into the electrolyte, and the volume expansion of sulfur. Herein, we report a novel composite MWCNTs@TiO2-S nanostructure by grafting TiO2 onto the surface of MWCNTs, followed by incorporating sulfur into the composite. The inner MWCNTs improved the mechanical strength and conductivity of the electrode and the outer TiO2 provided the adsorption sites to immobilize polysulfides due to bonding interaction between TiO2 and polysulfides. The MWCNTs@TiO2-S composite with a mass ratio of 50% (MWCNTs in MWCNTs@TiO2) exhibited the highest electrochemistry performance among all compositing ratios of MWCNTs/TiO2. The performance improvement might be attributed to the downward shift of the apparent Fermi level to a more positive potential and electron rich space region at the interface of MWCNTs-TiO2 that facilitates the reduction of lithium polysulfide at a higher potential. Such a novel hybrid structure can be applicable for electrode design in other energy storage applications. PMID:28098167

  14. Energy Management Strategy Based on the Driving Cycle Model for Plugin Hybrid Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Xiaoling Fu

    2014-01-01

    Full Text Available The energy management strategy (EMS for a plugin hybrid electric vehicle (PHEV is proposed based on the driving cycle model and dynamic programming (DP algorithm. A driving cycle model is constructed by collecting and processing the driving data of a certain school bus. The state of charge (SOC profile can be obtained by the DP algorithm for the whole driving cycle. In order to optimize the energy management strategy in the hybrid power system, the optimal motor torque control sequence can be calculated using the DP algorithm for the segments between the traffic intersections. Compared with the traditional charge depleting-charge sustaining (CDCS strategy, the test results on the ADVISOR platform show a significant improvement in fuel consumption using the EMS proposed in this paper.

  15. A hybrid Rankine cycle (HyRC) with ambient pressure combustion (APC)

    International Nuclear Information System (INIS)

    Wu, Lijun; Thimsen, David; Clements, Bruce; Zheng, Ligang; Pomalis, Richard

    2014-01-01

    The main losses in thermal power generation include heat in exhaust flue gas, heat rejected through steam condensation of low-pressure turbine, and exergy destruction in heat exchange process etc. To the extent that the heat losses are significantly greater in temperature than either air or water coolant resources, these losses also represent exergy losses which might be exploited to improve plant capacity and efficiency. This paper presents a hybrid Rankine cycle (HyRC) with an ambient pressure combustion (APC) boiler to address the recovery potential of these losses within the steam Rankine cycle (SRC). The APC–HyRC concept employs an organic Rankine cycle (ORC) to supplement SRC and to reduce cycle energy losses to the atmosphere since organic fluids are capable of lowering cycle condensation temperature when a very low temperature heat sink is available. The case studies based on a 399 MW SRC unit show that the APC–HyRC configurations have better thermodynamic performance than its base case SRC at a cycle condensation temperature of 30 °C and below. The best APC–HyRC configuration generates up to 14% more power than the baseline steam cycle which is a 5.45% increase in overall gross efficiency with a cycle condensation temperature at 4 °C. - Highlights: • A hybrid Rankine cycle with water and organic fluid is presented. • Heat losses in exhaust flue gas and exhaust steam are reduced. • Exergy losses in regeneration process are reduced. • Efficiency improvements are made to the conventional steam Rankine cycle. • Issues in design/construction of greenfield and repowering project are discussed

  16. Investigation of thermodynamic performances for two solar-biomass hybrid combined cycle power generation systems

    International Nuclear Information System (INIS)

    Liu, Qibin; Bai, Zhang; Wang, Xiaohe; Lei, Jing; Jin, Hongguang

    2016-01-01

    Highlights: • Two solar-biomass hybrid combined cycle power generation systems are proposed. • The characters of the two proposed systems are compared. • The on-design and off-design properties of the system are numerically investigated. • The favorable performances of thermochemical hybrid routine are validated. - Abstract: Two solar-biomass hybrid combined cycle power generation systems are proposed in this work. The first system employs the thermochemical hybrid routine, in which the biomass gasification is driven by the concentrated solar energy, and the gasified syngas as a solar fuel is utilized in a combined cycle for generating power. The second system adopts the thermal integration concept, and the solar energy is directly used to heat the compressed air in the topping Brayton cycle. The thermodynamic performances of the developed systems are investigated under the on-design and off-design conditions. The advantages of the hybrid utilization technical mode are demonstrated. The solar energy can be converted and stored into the chemical fuel by the solar-biomass gasification, with the net solar-to-fuel efficiency of 61.23% and the net solar share of 19.01% under the specific gasification temperature of 1150 K. Meanwhile, the proposed system with the solar thermochemical routine shows more favorable behaviors, the annual system overall energy efficiency and the solar-to-electric efficiency reach to 29.36% and 18.49%, while the with thermal integration concept of 28.03% and 15.13%, respectively. The comparison work introduces a promising approach for the efficient utilization of the abundant solar and biomass resources in the western China, and realizes the mitigation of CO_2 emission.

  17. Environmental, health, and safety issues of sodium-sulfur batteries for electric and hybrid vehicles. Volume 3, Transport of sodium-sulfur and sodium-metal-chloride batteries

    Energy Technology Data Exchange (ETDEWEB)

    Hammel, C J

    1992-09-01

    This report examines the shipping regulations that govern the shipment of dangerous goods. Since the elemental sodium contained in both sodium-sulfur and sodium-metal-chloride batteries is classified as a dangerous good, and is listed on both the national and international hazardous materials listings, both national and international regulatory processes are considered in this report The interrelationships as well as the differences between the two processes are highlighted. It is important to note that the transport regulatory processes examined in this report are reviewed within the context of assessing the necessary steps needed to provide for the domestic and international transport of sodium-beta batteries. The need for such an assessment was determined by the Shipping Sub-Working Group (SSWG) of the EV Battery Readiness Working Group (Working Group), created in 1990. The Working Group was created to examine the regulatory issues pertaining to in-vehicle safety, shipping, and recycling of sodium-sulfur batteries, each of which is addressed by a sub-working group. The mission of the SSWG is to establish basic provisions that will ensure the safe and efficient transport of sodium-beta batteries. To support that end, a proposal to the UN Committee of Experts was prepared by the SSWG, with the goal of obtaining a proper shipping name and UN number for sodium-beta batteries and to establish the basic transport requirements for such batteries (see the appendix for the proposal as submitted). It is emphasized that because batteries are large articles containing elemental sodium and, in some cases, sulfur, there is no existing UN entry under which they can be classified and for which modal transport requirements, such as the use of packaging appropriate for such large articles, are provided for. It is for this reason that a specific UN entry for sodium-beta batteries is considered essential.

  18. A general survey of the potential and the main issues associated with the sulfur-iodine thermochemical cycle for hydrogen production using nuclear heat

    International Nuclear Information System (INIS)

    Vitart, Xavier; Carles, Philippe; Anzieu, Pascal

    2008-01-01

    The thermochemical sulfur-iodine cycle is studied by CEA with the objective of massive hydrogen production using nuclear heat at high temperature. The challenge is to acquire by the end of 2008 the necessary decision elements, based on a scientific and validated approach, to choose the most promising way to produce hydrogen using a generation IV nuclear reactor. Amongst the thermochemical cycles, the sulfur-iodine process remains a very promising solution in matter of efficiency and cost, versus its main competitor, conventional electrolysis. The sulfur-iodine cycle is a very versatile process, which allows lot of variants for each section which can be adjusted in synergy in order to optimise the whole process. The main part of CEA's program is devoted to the study of the basic processes: new thermodynamics data acquisition, optimisation of water and iodine quantity, optimisation of temperature and pressure in each unit of the flow-sheet and survey of innovative solutions (membrane separations for instance). This program also includes optimisation of a detailed flow-sheet and studies for a hydrogen production plant (design, scale, first evaluations of safety issues and technico-economic questions). This program interacts strongly with other teams, in the framework of international collaborations (Europe, USA for instance). (author)

  19. A general survey of the potential and the main issues associated with the sulfur-iodine thermochemical cycle for hydrogen production using nuclear heat

    International Nuclear Information System (INIS)

    Vitart, X.; Carles, P.; Anzieu, P.

    2008-01-01

    The thermochemical sulfur-iodine cycle is studied by CEA with the objective of massive hydrogen production using nuclear heat at high temperature. The challenge is to acquire by the end of 2008 the necessary decision elements, based on a scientific and validated approach, to choose the most promising way to produce hydrogen using a generation IV nuclear reactor. Amongst the thermochemical cycles, the sulfur-iodine process remains a very promising solution in matter of efficiency and cost, versus its main competitor, conventional electrolysis. The sulfur-iodine cycle is a very versatile process, which allows lot of variants for each section which can be adjusted in synergy in order to optimise the whole process. The main part of CEA's program is devoted to the study of the basic processes: new thermodynamics data acquisition, optimisation of water and iodine quantity, optimisation of temperature and pressure in each unit of the flow-sheet and survey of innovative solutions (membrane separations for instance). This program also includes optimisation of a detailed flow-sheet and studies for a hydrogen production plant (design, scale, first evaluations of safety issues and technico-economic questions). This program interacts strongly with other teams, in the framework of international collaborations (Europe, USA for instance). (authors)

  20. Study of the hydrolysis reaction of the copper-chloride hybrid thermochemical cycle using optical spectrometries

    International Nuclear Information System (INIS)

    Doizi, D.; Borgard, J.M.; Dauvois, V.; Roujou, J.L.; Zanella, Y.; Croize, L.; Cartes, Ph.; Hartmann, J.M.

    2010-01-01

    The copper-chloride hybrid thermochemical cycle is one of the best potential low temperature thermochemical cycles for the massive production of hydrogen. It could be used with nuclear reactors such as the sodium fast reactor or the supercritical water reactor. Nevertheless, this thermochemical cycle is composed of an electrochemical reaction and two thermal reactions. Its efficiency has to be compared with other hydrogen production processes like alkaline electrolysis for example. The purpose of this article is to study the viability of the copper chloride thermochemical cycle by studying the hydrolysis reaction of CuCl 2 which is not favoured thermodynamically. To better understand the occurrence of possible side reactions, together with a good control of the kinetics of the hydrolysis reaction, the use of optical absorption spectrometries, UV visible spectrometry to detect molecular chlorine which may be formed in side reactions, FTIR spectrometry to follow the concentrations of H 2 O and HCl is proposed. (authors)

  1. Preliminary design and analysis on nuclear fuel cycle for fission-fusion hybrid spent fuel burner

    International Nuclear Information System (INIS)

    Chen Yan; Wang Minghuang; Jiang Jieqiong

    2012-01-01

    A wet-processing-based fuel cycle and a dry-processing were designed for a fission-fusion hybrid spent fuel burner (FDS-SFB). Mass flow of SFB was preliminarily analyzed. The feasibility analysis of initial loaded fuel inventory, recycle fuel fabrication and spent fuel reprocessing were preliminarily evaluated. The results of mass flow of FDS-SFB demonstrated that the initial loaded fuel inventory, recycle fuel fabrication and spent fuel reprocessing of nuclear fuel cycle of FDS-SFB is preliminarily feasible. (authors)

  2. Fuel economy and life-cycle cost analysis of a fuel cell hybrid vehicle

    Science.gov (United States)

    Jeong, Kwi Seong; Oh, Byeong Soo

    The most promising vehicle engine that can overcome the problem of present internal combustion is the hydrogen fuel cell. Fuel cells are devices that change chemical energy directly into electrical energy without combustion. Pure fuel cell vehicles and fuel cell hybrid vehicles (i.e. a combination of fuel cell and battery) as energy sources are studied. Considerations of efficiency, fuel economy, and the characteristics of power output in hybridization of fuel cell vehicle are necessary. In the case of Federal Urban Driving Schedule (FUDS) cycle simulation, hybridization is more efficient than a pure fuel cell vehicle. The reason is that it is possible to capture regenerative braking energy and to operate the fuel cell system within a more efficient range by using battery. Life-cycle cost is largely affected by the fuel cell size, fuel cell cost, and hydrogen cost. When the cost of fuel cell is high, hybridization is profitable, but when the cost of fuel cell is less than 400 US$/kW, a pure fuel cell vehicle is more profitable.

  3. Gasoline-powered serial hybrid cars cause lower life cycle carbon emissions than battery cars

    Science.gov (United States)

    Meinrenken, Christoph J.; Lackner, Klaus S.

    2011-04-01

    Battery cars powered by grid electricity promise reduced life cycle green house gas (GHG) emissions from the automotive sector. Such scenarios usually point to the much higher emissions from conventional, internal combustion engine cars. However, today's commercially available serial hybrid technology achieves the well known efficiency gains from regenerative breaking, lack of gearbox, and light weighting - even if the electricity is generated onboard, from conventional fuels. Here, we analyze emissions for commercially available, state-of the-art battery cars (e.g. Nissan Leaf) and those of commercially available serial hybrid cars (e.g., GM Volt, at same size and performance). Crucially, we find that serial hybrid cars driven on (fossil) gasoline cause fewer life cycle GHG emissions (126g CO2e per km) than battery cars driven on current US grid electricity (142g CO2e per km). We attribute this novel finding to the significant incremental life cycle emissions from battery cars from losses during grid transmission, battery dis-/charging, and larger batteries. We discuss crucial implications for strategic policy decisions towards a low carbon automotive sector as well as relative land intensity when powering cars by biofuel vs. bioelectricity.

  4. Watershed-scale changes in terrestrial nitrogen cycling during a period of decreased atmospheric nitrate and sulfur deposition

    Science.gov (United States)

    Sabo, Robert D.; Scanga, Sara E.; Lawrence, Gregory B.; Nelson, David M.; Eshleman, Keith N.; Zabala, Gabriel A.; Alinea, Alexandria A.; Schirmer, Charles D.

    2016-01-01

    Recent reports suggest that decreases in atmospheric nitrogen (N) deposition throughout Europe and North America may have resulted in declining nitrate export in surface waters in recent decades, yet it is unknown if and how terrestrial N cycling was affected. During a period of decreased atmospheric N deposition, we assessed changes in forest N cycling by evaluating trends in tree-ring δ15N values (between 1980 and 2010; n = 20 trees per watershed), stream nitrate yields (between 2000 and 2011), and retention of atmospherically-deposited N (between 2000 and 2011) in the North and South Tributaries (North and South, respectively) of Buck Creek in the Adirondack Mountains, USA. We hypothesized that tree-ring δ15N values would decline following decreases in atmospheric N deposition (after approximately 1995), and that trends in stream nitrate export and retention of atmospherically deposited N would mirror changes in tree-ring δ15N values. Three of the six sampled tree species and the majority of individual trees showed declining linear trends in δ15N for the period 1980–2010; only two individual trees showed increasing trends in δ15N values. From 1980 to 2010, trees in the watersheds of both tributaries displayed long-term declines in tree-ring δ15N values at the watershed scale (R = −0.35 and p = 0.001 in the North and R = −0.37 and p <0.001 in the South). The decreasing δ15N trend in the North was associated with declining stream nitrate concentrations (−0.009 mg N L−1 yr−1, p = 0.02), but no change in the retention of atmospherically deposited N was observed. In contrast, nitrate yields in the South did not exhibit a trend, and the watershed became less retentive of atmospherically deposited N (−7.3% yr−1, p < 0.001). Our δ15N results indicate a change in terrestrial N availability in both watersheds prior to decreases in atmospheric N deposition, suggesting that decreased atmospheric N deposition was not the sole driver of

  5. Hydraulic Hybrid and Conventional Parcel Delivery Vehicles' Measured Laboratory Fuel Economy on Targeted Drive Cycles

    Energy Technology Data Exchange (ETDEWEB)

    Lammert, M. P.; Burton, J.; Sindler, P.; Duran, A.

    2014-10-01

    This research project compares laboratory-measured fuel economy of a medium-duty diesel powered hydraulic hybrid vehicle drivetrain to both a conventional diesel drivetrain and a conventional gasoline drivetrain in a typical commercial parcel delivery application. Vehicles in this study included a model year 2012 Freightliner P100H hybrid compared to a 2012 conventional gasoline P100 and a 2012 conventional diesel parcel delivery van of similar specifications. Drive cycle analysis of 484 days of hybrid parcel delivery van commercial operation from multiple vehicles was used to select three standard laboratory drive cycles as well as to create a custom representative cycle. These four cycles encompass and bracket the range of real world in-use data observed in Baltimore United Parcel Service operations. The NY Composite cycle, the City Suburban Heavy Vehicle Cycle cycle, and the California Air Resources Board Heavy Heavy-Duty Diesel Truck (HHDDT) cycle as well as a custom Baltimore parcel delivery cycle were tested at the National Renewable Energy Laboratory's Renewable Fuels and Lubricants Laboratory. Fuel consumption was measured and analyzed for all three vehicles. Vehicle laboratory results are compared on the basis of fuel economy. The hydraulic hybrid parcel delivery van demonstrated 19%-52% better fuel economy than the conventional diesel parcel delivery van and 30%-56% better fuel economy than the conventional gasoline parcel delivery van on cycles other than the highway-oriented HHDDT cycle.

  6. Identity of major sulfur-cycle prokaryotes in freshwater lake ecosystems revealed by a comprehensive phylogenetic study of the dissimilatory adenylylsulfate reductase.

    Science.gov (United States)

    Watanabe, Tomohiro; Kojima, Hisaya; Fukui, Manabu

    2016-11-08

    Adenylylsulfate reductase is a heterodimeric complex of two subunits, AprB and AprA, and is a key enzyme in dissimilatory sulfate reduction and sulfur oxidation. Common use of aprA as a functional marker gene has revealed the diversity of sulfur-cycle prokaryotes in diverse environments. In this study, we established a comprehensive sequence set of apr genes and employed it to reanalyze apr phylogeny, evaluate the coverage of a widely used primer set (AprA-1-FW/AprA-5-RV), and categorize environmental aprA sequences. Phylogenetic tree construction revealed new members of Apr lineage II and several previously unrecognized lateral gene transfer events. Using the established phylogenetic tree, we classified all previously reported aprA sequences amplified from freshwater lakes with the primer pair AprA-1-FW/AprA-5-RV in addition to the aprA sequences newly retrieved from freshwater lakes; the obtained results were complemented by 16S rRNA clone library analysis. Apr-based classifications of some of operational taxonomic units were supported by 16S rRNA-based analysis. This study updates our knowledge on the phylogeny of aprBA and shows the identities of several sulfur-cycle bacteria, which could not be classified to a known taxa until now. The established apr sequence set is publicly available and can be applied to assign environmental sequences to known lineages.

  7. Emissions of toxic pollutants from compressed natural gas and low sulfur diesel-fueled heavy-duty transit buses tested over multiple driving cycles.

    Science.gov (United States)

    Kado, Norman Y; Okamoto, Robert A; Kuzmicky, Paul A; Kobayashi, Reiko; Ayala, Alberto; Gebel, Michael E; Rieger, Paul L; Maddox, Christine; Zafonte, Leo

    2005-10-01

    The number of heavy-duty vehicles using alternative fuels such as compressed natural gas (CNG) and new low-sulfur diesel fuel formulations and equipped with after-treatment devices are projected to increase. However, few peer-reviewed studies have characterized the emissions of particulate matter (PM) and other toxic compounds from these vehicles. In this study, chemical and biological analyses were used to characterize the identifiable toxic air pollutants emitted from both CNG and low-sulfur-diesel-fueled heavy-duty transit buses tested on a chassis dynamometer over three transient driving cycles and a steady-state cruise condition. The CNG bus had no after-treatment, and the diesel bus was tested first equipped with an oxidation catalyst (OC) and then with a catalyzed diesel particulate filter (DPF). Emissions were analyzed for PM, volatile organic compounds (VOCs; determined on-site), polycyclic aromatic hydrocarbons (PAHs), and mutagenic activity. The 2000 model year CNG-fueled vehicle had the highest emissions of 1,3-butadiene, benzene, and carbonyls (e.g., formaldehyde) of the three vehicle configurations tested in this study. The 1998 model year diesel bus equipped with an OC and fueled with low-sulfur diesel had the highest emission rates of PM and PAHs. The highest specific mutagenic activities (revertants/microg PM, or potency) and the highest mutagen emission rates (revertants/mi) were from the CNG bus in strain TA98 tested over the New York Bus (NYB) driving cycle. The 1998 model year diesel bus with DPF had the lowest VOCs, PAH, and mutagenic activity emission. In general, the NYB driving cycle had the highest emission rates (g/mi), and the Urban Dynamometer Driving Schedule (UDDS) had the lowest emission rates for all toxics tested over the three transient test cycles investigated. Also, transient emissions were, in general, higher than steady-state emissions. The emissions of toxic compounds from an in-use CNG transit bus (without an oxidation

  8. Free-Standing Hybrid Graphene Paper Encapsulating Nanostructures for High Cycle-Life Supercapacitors.

    Science.gov (United States)

    Jiao, Xinyan; Hao, Qingli; Xia, Xifeng; Lei, Wu; Ouyang, Yu; Ye, Haitao; Mandler, Daniel

    2018-03-09

    The incorporation of spacers between graphene sheets has been investigated as an effective method to improve the electrochemical performance of graphene papers (GPs) for supercapacitors. Here, we report the design of free-standing GP@NiO and GP@Ni hybrid GPs in which NiO nanoclusters and Ni nanoparticles are encapsulated into graphene sheets through electrostatic assembly and subsequent vacuum filtration. The encapsulated NiO nanoclusters and Ni nanoparticles can mitigate the restacking of graphene sheets, providing sufficient spaces for high-speed ion diffusion and electron transport. In addition, the spacers strongly bind to graphene sheets, which can efficiently improve the electrochemical stability. Therefore, at a current density of 0.5 A g -1 , the GP@NiO and GP@Ni electrodes exhibit higher specific capacitances of 306.9 and 246.1 F g -1 than the GP electrode (185.7 F g -1 ). The GP@NiO and GP@Ni electrodes exhibit capacitance retention of 98.7 % and 95.6 % after 10000 cycles, demonstrating an outstanding cycling stability. Additionally, the GP@NiO∥GP@Ni delivers excellent cycling stability (93.7 % after 10 000 cycles) and high energy density. These free-standing encapsulated hybrid GPs have great potential as electrode for high-performance supercapacitors. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Novel separation process of gaseous mixture of SO2 and O2 with ionic liquid for hydrogen production in thermochemical sulfur-iodine water splitting cycle

    International Nuclear Information System (INIS)

    Kim, Chang Soo; Gong, Gyeong Taek; Yoo, Kye Sang; Kim, Honggon; Lee, Byoung Gwon; Ahn, Byoung Sung; Jung, Kwang Deog; Lee, Ki Yong; Song, Kwang Ho

    2007-01-01

    Sulfur-Iodine cycle is the most promising thermochemical cycle for water splitting to produce hydrogen which can replace the fossil fuels in the future. As a sub-cycle in the thermochemical Sulfur-Iodine water splitting cycle, sulfuric acid (H 2 SO 4 ) decomposes into oxygen (O 2 ) and sulfur dioxide (SO 2 ) which should be separated for the recycle of SO 2 into the sulfuric acid generation reaction (Bunsen Reaction). In this study, absorption and desorption process of SO 2 by ionic liquid which is useful for the recycle of SO 2 into sulfuric acid generation reaction after sulfuric acid decomposition in the thermochemical Sulfur-Iodine cycle is investigated. At first, the operability as an absorbent for the SO 2 absorption and desorption at high temperature without the volatilization of absorbents which is not suitable for the recycle of absorbent-free SO 2 after the absorption process. The temperature range of operability is determined by TGA and DTA analysis. Most of ionic liquids investigated are applicable at high temperature desorption without volatility around 300 deg. C except [BMIm] Cl, and [BMIm] OAc which show the decomposition of ionic liquids. To evaluate the capability of SO 2 absorption, each ionic liquid is located in the absorption tube and gaseous SO 2 is bubbled into the ionic liquid. During the bubbling, the weight of the system is measured and converted into the absorbed SO 2 amount at each temperature controlled by the heater. Saturated amounts of absorbed SO 2 by ionic liquids at 50 deg. C are presented. The effect of anions for the SO 2 absorption capability is shown in the order of Cl, OAc, MeSO 3 , BF 4 , MeSO 4 , PF 6 , and HSO 4 when they are combined with [BMIm] cation. [BMIm]Cl has the largest amount of SO 2 absorbed which can be the most promising absorbent; however, from the point of operability at high temperature which includes desorption process, [BMIm]Cl is vulnerable to high temperature around 250 deg. C based on the TGA

  10. The control system of the ecological hybrid two stages refrigerating cycle

    Directory of Open Access Journals (Sweden)

    Cyklis Piotr

    2016-01-01

    Full Text Available The compression anticlockwise cycle is mostly used for refrigeration. However due to the environmental regulations, the use of classic refrigerants: F-gases is limited by international agreements. Therefore the combined compression-adsorption hybrid cycle with natural liquids: water/carbon dioxide working as the energy carriers is a promising solution. This allows to utilize the solar or waste energy for the refrigeration purpose. In this paper application of the solar collectors as the energy source for the adsorption cycle, coupled with the low temperature (LT refrigerating carbon dioxide compression cycle is shown. The control of the system is an essential issue to reduce the electric power consumption. The control of the solar heat supply and water sprayed cooling tower, for the adsorption cycle re-cooling, is presented in this paper. The designed control system and algorithm is related to the LT compression cycle, which operates according to the need of cold for the refrigeration chamber. The results of the laboratory investigations of the full system, showing the reduction of the energy consumption and maximum utilization of the solar heat for different control methods are presented.

  11. Feasibility of Thorium Fuel Cycles in a Very High Temperature Pebble-Bed Hybrid System

    Directory of Open Access Journals (Sweden)

    L.P. Rodriguez

    2015-08-01

    Full Text Available Nuclear energy presents key challenges to be successful as a sustainable energy source. Currently, the viability of the use thorium-based fuel cycles in an innovative nuclear energy generation system is being investigated in order to solve these key challenges. In this work, the feasibility of three thorium-based fuel cycles (232Th-233U, 232Th-239Pu, and 232Th-U in a hybrid system formed by a Very High Temperature Pebble-Bed Reactor (VHTR and two Pebble-Bed Accelerator Driven Systems (ADSs was evaluated using parameters related to the neutronic behavior such as nuclear fuel breeding, minor actinide stockpile, the energetic contribution of each fissile isotope, and the radiotoxicity of the long lived wastes. These parameters were used to compare the fuel cycles using the well-known MCNPX ver. 2.6e computational code. The results obtained confirm that the 232Th-233U fuel cycle is the best cycle for minimizing the production of plutonium isotopes and minor actinides. Moreover, the inclusion of the second stage in the ADSs demonstrated the possibility of extending the burnup cycle duration and reducing the radiotoxicity of the discharged fuel from the VHTR.

  12. Study on fission blanket fuel cycling of a fusion-fission hybrid energy generation system

    International Nuclear Information System (INIS)

    Zhou, Z.; Yang, Y.; Xu, H.

    2011-01-01

    This paper presents a preliminary study on neutron physics characteristics of a light water cooled fission blanket for a new type subcritical fusion-fission hybrid reactor aiming at electric power generation with low technical limits of fission fuel. The major objective is to study the fission fuel cycling performance in the blanket, which may possess significant impacts on the feasibility of the new concept of fusion-fission hybrid reactor with a high energy gain (M) and tritium breeding ratio (TBR). The COUPLE2 code developed by the Institute of Nuclear and New Energy Technology of Tsinghua University is employed to simulate the neutronic behaviour in the blanket. COUPLE2 combines the particle transport code MCNPX with the fuel depletion code ORIGEN2. The code calculation results show that soft neutron spectrum can yield M > 20 while maintaining TBR >1.15 and the conversion ratio of fissile materials CR > 1 in a reasonably long refuelling cycle (>five years). The preliminary results also indicate that it is rather promising to design a high-performance light water cooled fission blanket of fusion-fission hybrid reactor for electric power generation by directly loading natural or depleted uranium if an ITER-scale tokamak fusion neutron source is achievable.

  13. Gasoline-powered series hybrid cars cause lower life cycle carbon emissions than battery cars

    Science.gov (United States)

    Meinrenken, Christoph; Lackner, Klaus S.

    2012-02-01

    Battery cars powered by grid electricity promise reduced life cycle green house gas (GHG) emissions from the automotive sector. Such scenarios usually point to the much higher emissions from conventional, internal combustion engine cars. However, today's commercially available series hybrid technology achieves the well known efficiency gains in electric drivetrains (regenerative breaking, lack of gearbox) even if the electricity is generated onboard, from conventional fuels. Here, we analyze life cycle GHG emissions for commercially available, state-of the-art plug-in battery cars (e.g. Nissan Leaf) and those of commercially available series hybrid cars (e.g., GM Volt, at same size and performance). Crucially, we find that series hybrid cars driven on (fossil) gasoline cause fewer emissions (126g CO2eq per km) than battery cars driven on current US grid electricity (142g CO2eq per km). We attribute this novel finding to the significant incremental emissions from plug-in battery cars due to losses during grid transmission and battery dis-/charging, and manufacturing larger batteries. We discuss crucial implications for strategic policy decisions towards a low carbon automotive sector as well as relative land intensity when powering cars by biofuel vs. bioelectricity.

  14. A demand-centered, hybrid life-cycle methodology for city-scale greenhouse gas inventories.

    Science.gov (United States)

    Ramaswami, Anu; Hillman, Tim; Janson, Bruce; Reiner, Mark; Thomas, Gregg

    2008-09-01

    Greenhouse gas (GHG) accounting for individual cities is confounded by spatial scale and boundary effects that impact the allocation of regional material and energy flows. This paper develops a demand-centered, hybrid life-cycle-based methodology for conducting city-scale GHG inventories that incorporates (1) spatial allocation of surface and airline travel across colocated cities in larger metropolitan regions, and, (2) life-cycle assessment (LCA) to quantify the embodied energy of key urban materials--food, water, fuel, and concrete. The hybrid methodology enables cities to separately report the GHG impact associated with direct end-use of energy by cities (consistent with EPA and IPCC methods), as well as the impact of extra-boundary activities such as air travel and production of key urban materials (consistent with Scope 3 protocols recommended by the World Resources Institute). Application of this hybrid methodology to Denver, Colorado, yielded a more holistic GHG inventory that approaches a GHG footprint computation, with consistency of inclusions across spatial scale as well as convergence of city-scale per capita GHG emissions (approximately 25 mt CO2e/person/year) with state and national data. The method is shown to have significant policy impacts, and also demonstrates the utility of benchmarks in understanding energy use in various city sectors.

  15. A control-oriented cycle-life model for hybrid electric vehicle lithium-ion batteries

    International Nuclear Information System (INIS)

    Suri, Girish; Onori, Simona

    2016-01-01

    In this paper, a semi-empirical Lithium-iron phosphate-graphite battery aging model is identified over data mimicking actual cycling conditions that a hybrid electric vehicle battery encounters under real driving scenarios. The aging model is then used to construct the severity factor map, used to characterize relative aging of the battery under different operating conditions. This is used as a battery degradation criterion within a multi-objective optimization problem where battery aging minimization is to be achieved along with fuel consumption minimization. The method proposed is general and can be applied to other battery chemistry as well as different vehicular applications. Finally, simulations conducted using a hybrid electric vehicle simulator show how the two modeling tools developed in this paper, i.e., the severity factor map and the aging model, can be effectively used in a multi-objective optimization problem to predict and control battery degradation. - Highlights: • Battery aging model for hybrid electric vehicles using real driving conditions data. • Development of a modeling tool to assess battery degradation for real time optimization. • "3"1P NMR analysis of an enzyme-treated extract showed expected hydrolysis of P forms. • Development of an energy management strategy to minimize battery degradation. • Simulation results from hybrid electric vehicle simulator.

  16. Dynamic hybrid life cycle assessment of energy and carbon of multicrystalline silicon photovoltaic systems.

    Science.gov (United States)

    Zhai, Pei; Williams, Eric D

    2010-10-15

    This paper advances the life cycle assessment (LCA) of photovoltaic systems by expanding the boundary of the included processes using hybrid LCA and accounting for the technology-driven dynamics of embodied energy and carbon emissions. Hybrid LCA is an extended method that combines bottom-up process-sum and top-down economic input-output (EIO) methods. In 2007, the embodied energy was 4354 MJ/m(2) and the energy payback time (EPBT) was 2.2 years for a multicrystalline silicon PV system under 1700 kWh/m(2)/yr of solar radiation. These results are higher than those of process-sum LCA by approximately 60%, indicating that processes excluded in process-sum LCA, such as transportation, are significant. Even though PV is a low-carbon technology, the difference between hybrid and process-sum results for 10% penetration of PV in the U.S. electrical grid is 0.13% of total current grid emissions. Extending LCA from the process-sum to hybrid analysis makes a significant difference. Dynamics are characterized through a retrospective analysis and future outlook for PV manufacturing from 2001 to 2011. During this decade, the embodied carbon fell substantially, from 60 g CO(2)/kWh in 2001 to 21 g/kWh in 2011, indicating that technological progress is realizing reductions in embodied environmental impacts as well as lower module price.

  17. Multiple Origins and Nested Cycles of Hybridization Result in High Tetraploid Diversity in the Monocot Prospero.

    Science.gov (United States)

    Jang, Tae-Soo; Parker, John S; Emadzade, Khatere; Temsch, Eva M; Leitch, Andrew R; Weiss-Schneeweiss, Hanna

    2018-01-01

    Polyploidy is a major driving force in angiosperm evolution, but our understanding of establishment and early diversification processes following allo- vs. auto-polyploidy is limited. An excellent system to address such questions is the monocot plant Prospero autumnale , as it comprises several genomically and chromosomally distinct diploid cytotypes and their auto- and allotetraploid derivatives. To infer origins and evolutionary trajectories of the tetraploids, we use genome size data, in situ hybridization with parental genomic DNAs and specific probes (satDNA, rDNAs), as well as molecular-phylogenetic analyses. Thus, we demonstrate that an astounding range of allotetraploid lineages has been formed recurrently by chromosomal re-patterning, interactions of chromosomally variable parental genomes and nested cycles of extensive hybridization, whereas autotetraploids have originated at least twice and are cytologically stable. During the recurrent formation and establishment across wide geographic areas hybridization in some populations could have inhibited lineage diversification and nascent speciation of such a hybrid swarm. However, cytotypes that became fixed in populations enhanced the potential for species diversification, possibly exploiting the extended allelic base, and fixed heterozygosity that polyploidy confers. The time required for polyploid cytotype fixation may in part reflect the lag phase reported for polyploids between their formation and species diversification.

  18. Multiple Origins and Nested Cycles of Hybridization Result in High Tetraploid Diversity in the Monocot Prospero

    Directory of Open Access Journals (Sweden)

    Tae-Soo Jang

    2018-04-01

    Full Text Available Polyploidy is a major driving force in angiosperm evolution, but our understanding of establishment and early diversification processes following allo- vs. auto-polyploidy is limited. An excellent system to address such questions is the monocot plant Prospero autumnale, as it comprises several genomically and chromosomally distinct diploid cytotypes and their auto- and allotetraploid derivatives. To infer origins and evolutionary trajectories of the tetraploids, we use genome size data, in situ hybridization with parental genomic DNAs and specific probes (satDNA, rDNAs, as well as molecular-phylogenetic analyses. Thus, we demonstrate that an astounding range of allotetraploid lineages has been formed recurrently by chromosomal re-patterning, interactions of chromosomally variable parental genomes and nested cycles of extensive hybridization, whereas autotetraploids have originated at least twice and are cytologically stable. During the recurrent formation and establishment across wide geographic areas hybridization in some populations could have inhibited lineage diversification and nascent speciation of such a hybrid swarm. However, cytotypes that became fixed in populations enhanced the potential for species diversification, possibly exploiting the extended allelic base, and fixed heterozygosity that polyploidy confers. The time required for polyploid cytotype fixation may in part reflect the lag phase reported for polyploids between their formation and species diversification.

  19. Materials development for thermochemical cycles: sulfuric acid vaporizer. Semiannual technical report, October 1, 1977--March 31, 1978

    International Nuclear Information System (INIS)

    Krikorian, O.H.

    1978-01-01

    Installation of a sulfuric acid corrosion test facility has been completed and is described. The facility is to be used for testing of potential materials for containment and heat exchange of a sulfuric acid vaporizer at temperatures up to 725 0 K and boiling pressures of >20 atm (2 MPa). Materials that are ready for test are Duriron, Durichlor 51, single crystal Si, hot-pressed Si 3 N 4 (Noralide NC-132), and hot-pressed SiC (Crystar HD-435), and tests are expected to get underway in April pending Hazards Control approval

  20. Sizing for fuel cell/supercapacitor hybrid vehicles based on stochastic driving cycles

    International Nuclear Information System (INIS)

    Feroldi, Diego; Carignano, Mauro

    2016-01-01

    Highlights: • A sizing procedure based on the fulfilment of real driving conditions is proposed. • A methodology to generate long-term stochastic driving cycles is proposed. • A parametric optimization of the real-time EMS is conducted. • A trade-off design is adopted from a Pareto front. • A comparison with optimal consumption via Dynamic Programming is performed. - Abstract: In this article, a methodology for the sizing and analysis of fuel cell/supercapacitor hybrid vehicles is presented. The proposed sizing methodology is based on the fulfilment of power requirements, including sustained speed tests and stochastic driving cycles. The procedure to generate driving cycles is also presented in this paper. The sizing algorithm explicitly accounts for the Equivalent Consumption Minimization Strategy (ECMS). The performance is compared with optimal consumption, which is found using an off-line strategy via Dynamic Programming. The sizing methodology provides guidance for sizing the fuel cell and the supercapacitor number. The results also include analysis on oversizing the fuel cell and varying the parameters of the energy management strategy. The simulation results highlight the importance of integrating sizing and energy management into fuel cell hybrid vehicles.

  1. Life-cycle private costs of hybrid electric vehicles in the current Chinese market

    International Nuclear Information System (INIS)

    Lin, Chengtao; Wu, Tian; Ou, Xunmin; Zhang, Qian; Zhang, Xu; Zhang, Xiliang

    2013-01-01

    Understanding the life-cycle private cost (LCPC) of the hybrid electric vehicle (HEV) is important for market feasibility analysis. An HEV LCPC model was established to evaluate HEV market prospects in China compared with traditional internal combustion engine vehicles (ICEV). The Kluger HV, a full-hybrid HEV sports utility vehicle (SUV), aimed at the Chinese market, was simulated as the 2010 model's technology details were well publicized. The LCPC of the Kluger HV was roughly the same (about 1.06 times) as that of its comparable ICEV (Highlander SUV). This aligns with other compact and midsize HEV cars (e.g., Toyota Prius, Honda Civic and Toyota Camry HEV) in China. With oil prices predicted to rise in the long-term, the advantage of HEVs energy saving will partly compensate the high manufacturing costs associated with their additional motor/battery components. Besides supporting technology development, enabling policy should be implemented to introduce HEV technology into taxi fleets and business cars. This technology's cost-competitiveness, compared with traditional ICEVs, is advantageous for these higher mileage vehicles. - Highlights: ► A model is set up to evaluate the life-cycle private cost of HEVs. ► Life-cycle private costs of HEVs are higher than conventional cars in China. ► HEVs become competitive when the oil price rises

  2. Uranium-thorium fuel cycle in a very high temperature hybrid system

    International Nuclear Information System (INIS)

    Hernandez, C.R.G.; Oliva, A.M.; Fajardo, L.G.; Garcia, J.A.R.; Curbelo, J.P.; Abadanes, A.

    2011-01-01

    Thorium is a potentially valuable energy source since it is about three to four times as abundant as Uranium. It is also a widely distributed natural resource readily accessible in many countries. Therefore, Thorium fuels can complement Uranium fuels and ensure long term sustainability of nuclear power. The main advantages of the use of a hybrid system formed by a Pebble Bed critical nuclear reactor and two Pebble Bed Accelerator Driven Systems (ADSs) using a Uranium-Thorium (U + Th) fuel cycle are shown in this paper. Once-through and two step U + Th fuel cycle was evaluated. With this goal, a preliminary conceptual design of a hybrid system formed by a Graphite Moderated Gas-Cooled Very High Temperature Reactor and two ADSs is proposed. The main parameters related to the neutronic behavior of the system in a deep burn scheme are optimized. The parameters that describe the nuclear fuel breeding and Minor Actinide stockpile are compared with those of a simple Uranium fuel cycle. (author)

  3. Hybrid life cycle assessment comparison of colloidal silica and cement grouted soil barrier remediation technologies

    Energy Technology Data Exchange (ETDEWEB)

    Gallagher, Patricia M., E-mail: pmg24@drexel.edu [Civil, Architectural and Environmental Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19038 (United States); Spatari, Sabrina; Cucura, Jeffrey [Civil, Architectural and Environmental Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19038 (United States)

    2013-04-15

    Highlights: ► We use LCA to study environmental impacts of grouting techniques for site remediation. ► We consider colloidal silica permeation grouting and cement jet grouting. ► Manufacturing and transportation contribute significantly in all impact categories. ► Activity outside of direct site activity is important in assessing impacts. ► LCA can be used to consider sustainability criteria for remediation decisions. -- Abstract: Site remediation involves balancing numerous costs and benefits but often neglects the environmental impacts over the entire project life cycle. Life cycle assessment (LCA) offers a framework for inclusion of global environmental “systems-level” decision metrics in combination with technological and cost analysis. We compare colloidal silica (CS) and cement grouted soil barrier remediation technologies for soils affected by low level radionuclides at a U.S. Superfund site using hybrid LCA methods. CS is a new, high performance grouting material installed using permeation grouting techniques. Cement, a more traditional grouting material, is typically installed using jet grouting techniques. Life cycle impacts were evaluated using the US EPA TRACI 2 model. Results show the highest life cycle environmental impacts for the CS barrier occur during materials production and transportation to the site. In general, the life cycle impacts for the cement barrier were dominated by materials production; however, in the extreme scenario the life cycle impacts were dominated by truck transportation of spoils to a distant, off-site radioactive waste facility. It is only in the extreme scenario tested in which soils are transported by truck (Option 2) that spoils waste transport dominates LCIA results. Life cycle environmental impacts for both grout barriers were most sensitive to resource input requirements for manufacturing volumes and transportation. Uncertainty associated with the efficacy of new technology such as CS over its required

  4. Hybrid life cycle assessment comparison of colloidal silica and cement grouted soil barrier remediation technologies

    International Nuclear Information System (INIS)

    Gallagher, Patricia M.; Spatari, Sabrina; Cucura, Jeffrey

    2013-01-01

    Highlights: ► We use LCA to study environmental impacts of grouting techniques for site remediation. ► We consider colloidal silica permeation grouting and cement jet grouting. ► Manufacturing and transportation contribute significantly in all impact categories. ► Activity outside of direct site activity is important in assessing impacts. ► LCA can be used to consider sustainability criteria for remediation decisions. -- Abstract: Site remediation involves balancing numerous costs and benefits but often neglects the environmental impacts over the entire project life cycle. Life cycle assessment (LCA) offers a framework for inclusion of global environmental “systems-level” decision metrics in combination with technological and cost analysis. We compare colloidal silica (CS) and cement grouted soil barrier remediation technologies for soils affected by low level radionuclides at a U.S. Superfund site using hybrid LCA methods. CS is a new, high performance grouting material installed using permeation grouting techniques. Cement, a more traditional grouting material, is typically installed using jet grouting techniques. Life cycle impacts were evaluated using the US EPA TRACI 2 model. Results show the highest life cycle environmental impacts for the CS barrier occur during materials production and transportation to the site. In general, the life cycle impacts for the cement barrier were dominated by materials production; however, in the extreme scenario the life cycle impacts were dominated by truck transportation of spoils to a distant, off-site radioactive waste facility. It is only in the extreme scenario tested in which soils are transported by truck (Option 2) that spoils waste transport dominates LCIA results. Life cycle environmental impacts for both grout barriers were most sensitive to resource input requirements for manufacturing volumes and transportation. Uncertainty associated with the efficacy of new technology such as CS over its required

  5. Hybrid life cycle assessment comparison of colloidal silica and cement grouted soil barrier remediation technologies.

    Science.gov (United States)

    Gallagher, Patricia M; Spatari, Sabrina; Cucura, Jeffrey

    2013-04-15

    Site remediation involves balancing numerous costs and benefits but often neglects the environmental impacts over the entire project life cycle. Life cycle assessment (LCA) offers a framework for inclusion of global environmental "systems-level" decision metrics in combination with technological and cost analysis. We compare colloidal silica (CS) and cement grouted soil barrier remediation technologies for soils affected by low level radionuclides at a U.S. Superfund site using hybrid LCA methods. CS is a new, high performance grouting material installed using permeation grouting techniques. Cement, a more traditional grouting material, is typically installed using jet grouting techniques. Life cycle impacts were evaluated using the US EPA TRACI 2 model. Results show the highest life cycle environmental impacts for the CS barrier occur during materials production and transportation to the site. In general, the life cycle impacts for the cement barrier were dominated by materials production; however, in the extreme scenario the life cycle impacts were dominated by truck transportation of spoils to a distant, off-site radioactive waste facility. It is only in the extreme scenario tested in which soils are transported by truck (Option 2) that spoils waste transport dominates LCIA results. Life cycle environmental impacts for both grout barriers were most sensitive to resource input requirements for manufacturing volumes and transportation. Uncertainty associated with the efficacy of new technology such as CS over its required design life indicates that barrier replacement could increase its life cycle environmental impact above that of the cement barrier. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. A complete geothermal energy cycle with heat pumps and hybrid HVAC systems for the city of Denizli, Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Eltez, M. [Ege Univ., Izmir (Turkey). Mechanical Engineering Dept.; Kilkis, I.B. [Heatway Radiant Floors and Snowmelting, Springfield, MO (United States)]|[Middle East Technical Univ., Ankara (Turkey)

    1995-12-31

    This paper discusses general aspects of maximizing geofluid effectiveness by employing hybrid cycle plants coupled to district HVAC systems. Alternative and new techniques in space heating and cooling are also discussed. A case study is presented for the district HVAC system for the city of Denizli in Turkey. Results are compared with an open-cycle, open-loop system.

  7. MicroRNA-210 regulates mitochondrial free radical response to hypoxia and krebs cycle in cancer cells by targeting iron sulfur cluster protein ISCU.

    Directory of Open Access Journals (Sweden)

    Elena Favaro

    2010-04-01

    Full Text Available Hypoxia in cancers results in the upregulation of hypoxia inducible factor 1 (HIF-1 and a microRNA, hsa-miR-210 (miR-210 which is associated with a poor prognosis.In human cancer cell lines and tumours, we found that miR-210 targets the mitochondrial iron sulfur scaffold protein ISCU, required for assembly of iron-sulfur clusters, cofactors for key enzymes involved in the Krebs cycle, electron transport, and iron metabolism. Down regulation of ISCU was the major cause of induction of reactive oxygen species (ROS in hypoxia. ISCU suppression reduced mitochondrial complex 1 activity and aconitase activity, caused a shift to glycolysis in normoxia and enhanced cell survival. Cancers with low ISCU had a worse prognosis.Induction of these major hallmarks of cancer show that a single microRNA, miR-210, mediates a new mechanism of adaptation to hypoxia, by regulating mitochondrial function via iron-sulfur cluster metabolism and free radical generation.

  8. Draft Genome Sequence of Telmatospirillum siberiense 26-4b1, an Acidotolerant Peatland Alphaproteobacterium Potentially Involved in Sulfur Cycling.

    Science.gov (United States)

    Hausmann, Bela; Pjevac, Petra; Schreck, Katharina; Herbold, Craig W; Daims, Holger; Wagner, Michael; Loy, Alexander

    2018-01-25

    The facultative anaerobic chemoorganoheterotrophic alphaproteobacterium Telmatospirillum siberiense 26-4b1 was isolated from a Siberian peatland. We report here a 6.20-Mbp near-complete high-quality draft genome sequence of T. siberiense that reveals expected and novel metabolic potential for the genus Telmatospirillum , including genes for sulfur oxidation. Copyright © 2018 Hausmann et al.

  9. A synergetic hybridization of adsorption cycle with the multi-effect distillation (MED)

    KAUST Repository

    Thu, K.

    2014-01-01

    Multi-effect distillation (MED) systems are proven and energy efficient thermally-driven desalination systems for handling harsh seawater feed in the Gulf region. The high cycle efficiency is markedly achieved by latent energy re-use with minimal stage temperature-difference across the condensing steam and the evaporating saline seawater in each stage. The efficacies of MED system are (i) its low stage-temperature-difference between top brine temperature (TBT) and final condensing temperature, (ii) its robustness to varying salinity and ability to handle harmful algae Blooming (HABs) and (iii) its compact foot-print per unit water output. The practical TBT of MED systems, hitherto, is around 65 C for controllable scaling and fouling with the ambient-limited final condenser temperature, usually from 30 to 45 C. The adsorption (ADC) cycles utilize low-temperature heat sources (typically below 90 C) to produce useful cooling power and potable water. Hybridizing MED with AD cycles, they synergistically improve the water production rates at the same energy input whilst the AD cycle is driven by the recovered waste heat. We present a practical AD + MED combination that can be retrofitted to existing MEDs: The cooling energy of AD cycle through the water vapor uptake by the adsorbent is recycled internally, providing lower temperature condensing environment in the effects whilst the final condensing temperature of MED is as low as 5-10 C, which is below ambient. The increase in the temperature difference between TBT and final condensing temperature accommodates additional MED stages. A detailed numerical model is presented to capture the transient behaviors of heat and mass interactions in the combined AD + MED cycles and the results are presented in terms of key variables. It is observed that the water production rates of the combined cycle increase to give a GOR of 8.8 from an initial value of 5.9. © 2013 Elsevier Ltd. All rights reserved.

  10. The impact of the Cretaceous-Paleogene (K-Pg) mass extinction event on the global sulfur cycle: Evidence from Seymour Island, Antarctica

    Science.gov (United States)

    Witts, James D.; Newton, Robert J.; Mills, Benjamin J. W.; Wignall, Paul B.; Bottrell, Simon H.; Hall, Joanna L. O.; Francis, Jane E.; Alistair Crame, J.

    2018-06-01

    The Cretaceous-Paleogene (K-Pg) mass extinction event 66 million years ago led to large changes to the global carbon cycle, primarily via a decrease in primary or export productivity of the oceans. However, the effects of this event and longer-term environmental changes during the Late Cretaceous on the global sulfur cycle are not well understood. We report new carbonate associated sulfate (CAS) sulfur isotope data derived from marine macrofossil shell material from a highly expanded high latitude Maastrichtian to Danian (69-65.5 Ma) succession located on Seymour Island, Antarctica. These data represent the highest resolution seawater sulfate record ever generated for this time interval, and are broadly in agreement with previous low-resolution estimates for the latest Cretaceous and Paleocene. A vigorous assessment of CAS preservation using sulfate oxygen, carbonate carbon and oxygen isotopes and trace element data, suggests factors affecting preservation of primary seawater CAS isotopes in ancient biogenic samples are complex, and not necessarily linked to the preservation of original carbonate mineralogy or chemistry. Primary data indicate a generally stable sulfur cycle in the early-mid Maastrichtian (69 Ma), with some fluctuations that could be related to increased pyrite burial during the 'mid-Maastrichtian Event'. This is followed by an enigmatic +4‰ increase in δ34SCAS during the late Maastrichtian (68-66 Ma), culminating in a peak in values in the immediate aftermath of the K-Pg extinction which may be related to temporary development of oceanic anoxia in the aftermath of the Chicxulub bolide impact. There is no evidence of the direct influence of Deccan volcanism on the seawater sulfate isotopic record during the late Maastrichtian, nor of a direct influence by the Chicxulub impact itself. During the early Paleocene (magnetochron C29R) a prominent negative excursion in seawater δ34S of 3-4‰ suggests that a global decline in organic carbon burial

  11. A hybrid system using a regenerative electrochemical cycle to harvest waste heat from the proton exchange membrane fuel cell

    International Nuclear Information System (INIS)

    Long, Rui; Li, Baode; Liu, Zhichun; Liu, Wei

    2015-01-01

    A new hybrid system consisting of a PEMFC (proton exchange membrane fuel cell) subsystem and a TREC (thermally regenerative electrochemical cycle) subsystem is proposed to convert the waste heat produced by the PEMFC system into electricity. The performance of the hybrid system and its corresponding subsystems is analyzed. Results reveal that there exists optimal current densities of the PEMFC and TREC systems leading to the maximum power output of the hybrid system. With the maximum power output as the objective function, an optimization of the hybrid system based on genetic algorithm method is conducted under different operating temperatures of the PEMFC subsystem. The power output of the hybrid system is 6.85%–20.59% larger than that of the PEMFC subsystem. And the total electrical efficiency is improved by 2.74%–8.27%. The corresponding electrical efficiency of the TREC is 4.56%–13.81%. The hybrid system proposed in this paper could contribute to utilizing the fuel energy more efficiently and sufficiently. - Highlights: • A hybrid power system consisting of a PEMFC and a TREC subsystems is proposed. • Parameters' impacts on performance of the hybrid system have been analyzed. • The maximum power output of the hybrid system is investigated based on genetic algorithm. • Total power output of the hybrid system is 7.63%–18.84% larger than that of the PEMFC subsystem.

  12. Life cycle cost analysis of single slope hybrid (PV/T) active solar still

    International Nuclear Information System (INIS)

    Kumar, Shiv; Tiwari, G.N.

    2009-01-01

    This paper presents the life cycle cost analysis of the single slope passive and hybrid photovoltaic (PV/T) active solar stills, based on the annual performance at 0.05 m water depth. Effects of various parameters, namely interest rate, life of the system and the maintenance cost have been taken into account. The comparative cost of distilled water produced from passive solar still (Rs. 0.70/kg) is found to be less than hybrid (PV/T) active solar still (Rs. 1.93/kg) for 30 years life time of the systems. The payback periods of the passive and hybrid (PV/T) active solar still are estimated to be in the range of 1.1-6.2 years and 3.3-23.9 years, respectively, based on selling price of distilled water in the range of Rs. 10/kg to Rs. 2/kg. The energy payback time (EPBT) has been estimated as 2.9 and 4.7 years, respectively. (author)

  13. Integrated laboratory scale demonstration experiment of the hybrid sulphur cycle and preliminary scale-up

    International Nuclear Information System (INIS)

    Leybros, J.; Rivalier, P.; Saturnin, A.; Charton, S.

    2010-01-01

    The hybrid sulphur cycle is today one of the most promising processes to produce hydrogen on a massive scale within the scope of high temperature nuclear reactors development. Thus, the Fuel Cycle Technology Department at CEA Marcoule is involved in studying the hybrid sulphur process from a technical and economical performance standpoint. Based on mass and energy balance calculations, a ProsimPlus TM flow sheet and a commercial plant design were prepared. This work includes a study on sizing of the main equipment. The capital cost has been estimated using the major characteristics of main equipment based upon formulae and charts published in literature. A specific approach has been developed for electrolysers. Operational costs are also proposed for a plant producing 1000 mol/s H 2 . Bench scale and pilot experiments must focus on the electrochemical step due to limited experimental data. Thus, a pilot plant with a hydrogen capacity of 100 NL/h was built with the aim of acquiring technical and technological data for electrolysis. This pilot plant was designed to cover a wide range of operating conditions: sulphuric acid concentrations up to 60 wt.%, temperatures up to 100 deg. C and pressures up to 10 bar. New materials and structures recently developed for fuel cells, which are expected to yield significant performance improvements when applied to classical electrochemical processes, will be tested. All experiments will be coupled with phenomenological simulation tools developed jointly with the experimental programme. (authors)

  14. Life cycle assessment of greenhouse gas emissions from plug-in hybrid vehicles: implications for policy.

    Science.gov (United States)

    Samaras, Constantine; Meisterling, Kyle

    2008-05-01

    Plug-in hybrid electric vehicles (PHEVs), which use electricity from the grid to power a portion of travel, could play a role in reducing greenhouse gas (GHG) emissions from the transport sector. However, meaningful GHG emissions reductions with PHEVs are conditional on low-carbon electricity sources. We assess life cycle GHG emissions from PHEVs and find that they reduce GHG emissions by 32% compared to conventional vehicles, but have small reductions compared to traditional hybrids. Batteries are an important component of PHEVs, and GHGs associated with lithium-ion battery materials and production account for 2-5% of life cycle emissions from PHEVs. We consider cellulosic ethanol use and various carbon intensities of electricity. The reduced liquid fuel requirements of PHEVs could leverage limited cellulosic ethanol resources. Electricity generation infrastructure is long-lived, and technology decisions within the next decade about electricity supplies in the power sector will affectthe potential for large GHG emissions reductions with PHEVs for several decades.

  15. Carbon footprint evaluation at industrial park level: A hybrid life cycle assessment approach

    International Nuclear Information System (INIS)

    Dong, Huijuan; Geng, Yong; Xi, Fengming; Fujita, Tsuyoshi

    2013-01-01

    Industrial parks have become the effective strategies for government to promote sustainable economic development due to the following advantages: shared infrastructure and concentrated industrial activities within planned areas. However, due to intensive energy consumption and dependence on fossil fuels, industrial parks have become the main areas for greenhouse gas emissions. Therefore, it is critical to quantify their carbon footprints so that appropriate emission reduction policies can be raised. The objective of this paper is to seek an appropriate method on evaluating the carbon footprint of one industrial park. The tiered hybrid LCA method was selected due to its advantages over other methods. Shenyang Economic and Technological Development Zone (SETDZ), a typical comprehensive industrial park in China, was chosen as a case study park. The results show that the total life cycle carbon footprint of SETDZ was 15.29 Mt, including 6.81 Mt onsite (direct) carbon footprint, 8.47 Mt upstream carbon footprint, and only 3201 t downstream carbon footprint. Analysis from industrial sector perspectives shows that chemical industry and manufacture of general purpose machinery and special purposes machinery sector were the two largest sectors for life cycle carbon footprint. Such a sector analysis may be useful for investigation of appropriate emission reduction policies. - Highlights: ► A hybrid LCA model was employed to calculate industrial park carbon footprint. ► A case study on SETDZ is done. ► Life cycle carbon footprint of SETDZ is 15.29 Mt. ► Upstream and onsite carbon footprints account for 55.40% and 44.57%, respectively. ► Chemical industry and machinery manufacturing sectors are the two largest sectors

  16. Influence of driving patterns on life cycle cost and emissions of hybrid and plug-in electric vehicle powertrains

    International Nuclear Information System (INIS)

    Karabasoglu, Orkun; Michalek, Jeremy

    2013-01-01

    We compare the potential of hybrid, extended-range plug-in hybrid, and battery electric vehicles to reduce lifetime cost and life cycle greenhouse gas emissions under various scenarios and simulated driving conditions. We find that driving conditions affect economic and environmental benefits of electrified vehicles substantially: Under the urban NYC driving cycle, hybrid and plug-in vehicles can cut life cycle emissions by 60% and reduce costs up to 20% relative to conventional vehicles (CVs). In contrast, under highway test conditions (HWFET) electrified vehicles offer marginal emissions reductions at higher costs. NYC conditions with frequent stops triple life cycle emissions and increase costs of conventional vehicles by 30%, while aggressive driving (US06) reduces the all-electric range of plug-in vehicles by up to 45% compared to milder test cycles (like HWFET). Vehicle window stickers, fuel economy standards, and life cycle studies using average lab-test vehicle efficiency estimates are therefore incomplete: (1) driver heterogeneity matters, and efforts to encourage adoption of hybrid and plug-in vehicles will have greater impact if targeted to urban drivers vs. highway drivers; and (2) electrified vehicles perform better on some drive cycles than others, so non-representative tests can bias consumer perception and regulation of alternative technologies. We discuss policy implications. - Highlights: • Electrified vehicle life cycle emissions and cost depend on driving conditions. • GHGs can triple in NYC conditions vs. highway (HWFET), cost +30%. • Under NYC conditions hybrid and plug-in vehicles cut GHGs up to 60%, cost 20%. • Under HWFET conditions they offer few GHG reductions at higher costs. • Federal tests for window labels and CAFE standards favor some technologies over others

  17. Environmental, health, and safety issues of sodium-sulfur batteries for electric and hybrid vehicles. Volume 4, In-vehicle safety

    Energy Technology Data Exchange (ETDEWEB)

    Mark, J.

    1992-11-01

    This report is the last of four volumes that identify and assess the environmental, health, and safety issues that may affect the commercial-scale use of sodium-sulfur (Na/S) battery technology as the energy source in electric and hybrid vehicles. The reports are intended to help the Electric and Hybrid Propulsion Division of the Office of Transportation Technologies in the US Department of Energy (DOE/EHP) determine the direction of its research, development, and demonstration (RD&D) program for Na/S battery technology. The reports review the status of Na/S battery RD&D and identify potential hazards and risks that may require additional research or that may affect the design and use of Na/S batteries. This volume covers the in-vehicle safety issues of electric vehicles powered by Na/S batteries. The report is based on a review of the literature and on discussions with experts at DOE, national laboratories and agencies, and private industry. It has three major goals: (1) to identify the unique hazards associated with electric vehicle (EV) use; (2) to describe the existing standards, regulations, and guidelines that are or could be applicable to these hazards; and (3) to discuss the adequacy of the existing requirements in addressing the safety concerns of EVs.

  18. Neutronic behavior of thorium fuel cycles in a very high temperature hybrid system

    International Nuclear Information System (INIS)

    Rodriguez Garcia, Lorena; Milian Perez, Daniel; Garcia Hernandez, Carlos; Milian Lorenzo, Daniel; Velasco, Abanades

    2013-01-01

    Nuclear energy needs to guarantee four important issues to be successful as a sustainable energy source: nuclear safety, economic competitiveness, proliferation resistance and a minimal production of radioactive waste. Pebble bed reactors (PBR), which are very high temperature systems together with fuel cycles based in Thorium, they could offer the opportunity to meet the sustainability demands. Thorium is a potentially valuable energy source since it is about three to four times as abundant as Uranium. It is also a widely distributed natural resource readily accessible in many countries. This paper shows the main advantages of the use of a hybrid system formed by a Pebble Bed critical nuclear reactor and two Pebble Bed Accelerator Driven Systems (ADSs) using a variety of fuel cycles with Thorium (Th+U 233 , Th+Pu 239 and Th+U). The parameters related to the neutronic behavior like deep burn, nuclear fuel breeding, Minor Actinide stockpile, power density profiles and other are used to compare the fuel cycles using the well-known MCNPX computational code. (author)

  19. Neutronic behavior of thorium fuel cycles in a very high temperature hybrid system

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Garcia, Lorena; Milian Perez, Daniel; Garcia Hernandez, Carlos; Milian Lorenzo, Daniel, E-mail: dperez@instec.cu, E-mail: cgh@instec.cu, E-mail: dmilian@instec.cu [Higher Institute of Technologies and Applied Sciences, Havana (Cuba); Velasco, Abanades, E-mail: abanades@etsii.upm.es [Department of Simulation of Thermo Energy Systems, Polytechnic University of Madrid (Spain)

    2013-07-01

    Nuclear energy needs to guarantee four important issues to be successful as a sustainable energy source: nuclear safety, economic competitiveness, proliferation resistance and a minimal production of radioactive waste. Pebble bed reactors (PBR), which are very high temperature systems together with fuel cycles based in Thorium, they could offer the opportunity to meet the sustainability demands. Thorium is a potentially valuable energy source since it is about three to four times as abundant as Uranium. It is also a widely distributed natural resource readily accessible in many countries. This paper shows the main advantages of the use of a hybrid system formed by a Pebble Bed critical nuclear reactor and two Pebble Bed Accelerator Driven Systems (ADSs) using a variety of fuel cycles with Thorium (Th+U{sup 233}, Th+Pu{sup 239} and Th+U). The parameters related to the neutronic behavior like deep burn, nuclear fuel breeding, Minor Actinide stockpile, power density profiles and other are used to compare the fuel cycles using the well-known MCNPX computational code. (author)

  20. Hybrid Life Cycle Assessment of Low, Mid and High-Rise Multi-Family Dwellings

    Directory of Open Access Journals (Sweden)

    Kimberly Bawden

    2015-04-01

    Full Text Available We undertake Life Cycle Assessment (LCA of the cumulative energy demand (CED and global warming potential (GWP for a portfolio of 10 multi-family residences in the U.S. We argue that prior LCA studies of buildings use an inconsistent boundary for processes to be included in the supply chain: The operational phase includes all energy use in a building, but supply chains for the production of appliances, equipment and consumables associated with activities done in the building are neglected. We correct this by starting the analysis with an explicit definition of a functional unit, providing climate controlled space, and including processes associated with this functional unit. Using a hybrid LCA approach, the CED for low, mid and high-rise multi-family residences is found to increase from 30, 34, to 39 GJ/m2, respectively. This increase is due to the need for energy-intensive structural materials such as concrete and steel in taller buildings. With our approach, the share of materials and construction of total life cycle energy doubles to 26%, compared with a 13% share that would be obtained with inconsistent system boundaries used in prior studies. We thus argue that explicit definition of functional unit leads to an increase in the contribution of supply chains to building energy life cycles.

  1. 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.

  2. One-step hydrothermal synthesis of three-dimensional porous graphene aerogels/sulfur nanocrystals for lithium–sulfur batteries

    International Nuclear Information System (INIS)

    Jiang, Yong; Lu, Mengna; Ling, Xuetao; Jiao, Zheng; Chen, Lingli; Chen, Lu; Hu, Pengfei; Zhao, Bing

    2015-01-01

    Highlights: • 3D porous GA/S nanocrystals are prepared by a one-step hydrothermal method. • The structure is affected by hydrothermal temperature and liquid sulfur’s viscosity. • The hybrid delivers a capacity of 716.2 mA h g −1 after 50 cycles at 100 mA g −1 . • The nanosized S, strong adsorbability and intimate contact of GNS are main factors. - Abstract: Lithium–sulfur (Li–S) batteries are receiving significant attention as a new energy source because of its high theoretical capacity and specific energy. However, the low sulfur loading and large particles (usually in submicron dimension) in the cathode greatly offset its advantage in high energy density and lead to the instability of the cathode and rapid capacity decay. Herein, we introduce a one-step hydrothermal synthesis of three-dimensional porous graphene aerogels/sulfur nanocrystals to suppress the rapid fading of sulfur electrode. It is found that the hydrothermal temperature and viscosity of liquid sulfur have significant effects on particle size and loading mass of sulfur nanocrystals, graphitization degree of graphene and chemical bonding between sulfur and oxygen-containing groups of graphene. The hybrid could deliver a specific capacity of 716.2 mA h g −1 after 50 cycles at a current density of 100 mA g −1 and reversible capacity of 517.9 mA h g −1 at 1 A g −1 . The performance we demonstrate herein suggests that Li–S battery may provide an opportunity for development of rechargeable battery systems

  3. One-step hydrothermal synthesis of three-dimensional porous graphene aerogels/sulfur nanocrystals for lithium–sulfur batteries

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Yong; Lu, Mengna; Ling, Xuetao; Jiao, Zheng; Chen, Lingli; Chen, Lu [School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444 (China); Hu, Pengfei [Instrumental Analysis and Research Center, Shanghai University, Shanghai 200444 (China); Zhao, Bing, E-mail: bzhao@shu.edu.cn [School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444 (China)

    2015-10-05

    Highlights: • 3D porous GA/S nanocrystals are prepared by a one-step hydrothermal method. • The structure is affected by hydrothermal temperature and liquid sulfur’s viscosity. • The hybrid delivers a capacity of 716.2 mA h g{sup −1} after 50 cycles at 100 mA g{sup −1}. • The nanosized S, strong adsorbability and intimate contact of GNS are main factors. - Abstract: Lithium–sulfur (Li–S) batteries are receiving significant attention as a new energy source because of its high theoretical capacity and specific energy. However, the low sulfur loading and large particles (usually in submicron dimension) in the cathode greatly offset its advantage in high energy density and lead to the instability of the cathode and rapid capacity decay. Herein, we introduce a one-step hydrothermal synthesis of three-dimensional porous graphene aerogels/sulfur nanocrystals to suppress the rapid fading of sulfur electrode. It is found that the hydrothermal temperature and viscosity of liquid sulfur have significant effects on particle size and loading mass of sulfur nanocrystals, graphitization degree of graphene and chemical bonding between sulfur and oxygen-containing groups of graphene. The hybrid could deliver a specific capacity of 716.2 mA h g{sup −1} after 50 cycles at a current density of 100 mA g{sup −1} and reversible capacity of 517.9 mA h g{sup −1} at 1 A g{sup −1}. The performance we demonstrate herein suggests that Li–S battery may provide an opportunity for development of rechargeable battery systems.

  4. Interfacial Engineered Polyaniline/Sulfur-doped TiO2 Nanotube Arrays for Ultralong Cycle Lifetime Fiber-Shaped, Solid-State Supercapacitors.

    Science.gov (United States)

    Li, Chun; Wang, Zhuanpei; Li, Shengwen; Cheng, Jianli; Zhang, Yanning; Zhou, Jingwen; Yang, Dan; Tong, Dong-Ge; Wang, Bin

    2018-05-04

    Fiber-shaped supercapacitors (FSCs) have great potential in wearable electronics applications. However, the limited specific surface area and inadequate structural stability caused by the weak interfacial interactions of the electrodes result in relatively low specific capacitance and unsatisfactory cycle lifetime. Herein, solid-state FSCs with high energy density and ultralong cycle lifetime based on polyaniline (PANI)/sulfur-doped TiO2 nanotubes array (PANI/S-TiO2) are fabricated by interfacial engineering. The experimental results and ab initio calculations reveal that S doping can effectively promote the conductivity of titania nanotubes and increase the binding energy of PANI anchored on the electrode surface, leading to much stronger binding of PANI on the surface of the electrode and excellent electrode structure stability. As a result, the FSCs using the PANI/S-TiO2 electrodes deliver a high specific capacitance of 91.9 mF cm-2, a capacitance retention of 93.78% after 12,000 charge/discharge cycles, and an areal energy density of 3.2 µWh cm-2, respectively. Meanwhile, the all-solid-state FSC device retains its excellent flexibility and stable electrochemical capacitance even after bending 150 cycles. The enhanced performances of FSCs could be attributed to the large surface area, short ion diffusion path, high electrical conductivity and engineered interfacial interaction of the rationally designed electrodes.

  5. Life cycle energy metrics and CO 2 credit analysis of a hybrid photovoltaic/thermal greenhouse dryer

    OpenAIRE

    P. Barnwal; G. N. Tiwari

    2008-01-01

    In this paper, life cycle energy metrics, such as energy payback time (EPBT), energy production factor (EPF) and life cycle conversion efficiency (LCCE), and mitigation of CO 2 emissions for a hybrid photovoltaic/thermal (PV/T) greenhouse dryer have been analyzed. The hybrid PV/T greenhouse (roof type even span) dryer, designed and constructed at Solar Energy Park, Indian Institute of Technology, New Delhi (28°35′N, 77°12′E, 216 m above MSL), India, has a 2.50 m × 2.60 m floor area, 1.80 m ce...

  6. Isotopic composition of reduced and oxidized sulfur in the Canary Islands: implications for the mantle S cycle

    Science.gov (United States)

    Beaudry, P.; Longpre, M. A.; Wing, B. A.; Bui, T. H.; Stix, J.

    2017-12-01

    The Earth's mantle contains distinct sulfur reservoirs, which can be probed by sulfur isotope analyses of volcanic rocks and gases. We analyzed the isotopic composition of reduced and oxidized sulfur in a diverse range of volcanically derived materials spanning historical volcanism in the Canary Islands. Our sample set consists of subaerial volcanic tephras from three different islands, mantle and sedimentary xenoliths, as well as lava balloon samples from the 2011-2012 submarine El Hierro eruption and associated crystal separates. This large sample set allows us to differentiate between the various processes responsible for sulfur isotope heterogeneity in the Canary archipelago. Our results define an array in triple S isotope space between the compositions of the MORB and seawater sulfate reservoirs. Specifically, the sulfide values are remarkably homogeneous around d34S = -1 ‰ and D33S = -0.01 ‰, while sulfate values peak at d34S = +4 ‰ and D33S = +0.01 ‰. Lava balloons from the El Hierro eruption have highly enriched sulfate d34S values up to +19.3 ‰, reflecting direct interaction between seawater sulfate and the erupting magma. Several sulfate data points from the island of Lanzarote also trend towards more positive d34S up to +13.8 ‰, suggesting interaction with seawater sulfate-enriched lithologies or infiltration of seawater within the magmatic system. On the other hand, the modal values and relative abundances of S2- and S6+ in crystal separates suggest that the Canary Island mantle source has a d34S around +3 ‰, similar to the S-isotopic composition of a peridotite xenolith from Lanzarote. We infer that the S2- and S6+ modes reflect isotopic equilibrium between those species in the magmatic source, which requires 80 % of the sulfide to become oxidized after melting, consistent with measured S speciation. This 34S enrichment of the source could be due to the recycling of hydrothermally-altered oceanic crust, which has been previously suggested

  7. A Nanoscale Study of Carbon and Nitrogen Fluxes in Mats of Purple Sulfur Bacteria: Implications for Carbon Cycling at the Surface of Coastal Sediments

    Directory of Open Access Journals (Sweden)

    Cédric Hubas

    2017-10-01

    Full Text Available Mass blooms of purple sulfur bacteria growing seasonally on green stranded macroalgae have a major impact on the microbial composition and functionality of intertidal mats. To explore the active anoxygenic phototrophic community in purple bacterial mats from the Roscoff Aber Bay (Brittany, France, we conducted a combined approach including molecular and high-resolution secondary ion mass spectrometry (NanoSIMS analyses. To investigate the dynamics of carbon and nitrogen assimilation activities, NanoSIMS was coupled with a stable isotope probing (SIP experiment and a compound specific isotope analysis (CSIA of fatty acid methyl ester (FAME. Sediment samples were incubated with 13C- and/or 15N-labeled acetate, pyruvate, bicarbonate and ammonium. NanoSIMS analysis of 13C - and 15N -incubated samples showed elevated incorporations of 13C - and 15N in the light and of 13C -acetate in the dark into dense populations of spherical cells that unambiguously dominated the mats. These results confirmed CSIA data that ranked vaccenic acid, an unambiguous marker of purple sulfur bacteria, as the most strongly enriched in the light after 13C -acetate amendment and indicated that acetate uptake, the most active in the mat, was not light-dependent. Analysis of DNA- and cDNA-derived pufM gene sequences revealed that Thiohalocapsa-related clones dominated both libraries and were the most photosynthetically active members of the mat samples. This study provides novel insights into the contribution of purple sulfur bacteria to the carbon cycle during their seasonal developments at the sediment surface in the intertidal zone.

  8. Current hybrid-electric powertrain architectures: Applying empirical design data to life cycle assessment and whole-life cost analysis

    International Nuclear Information System (INIS)

    Hutchinson, Tim; Burgess, Stuart; Herrmann, Guido

    2014-01-01

    Highlights: • Design data for 44 hybrid cars available in the US has been gathered and analysed. • An empirical life cycle assessment of greenhouse gas emissions is performed. • Empirical whole-life cost modelling is used to evaluate powertrain architectures. • The value to be seen in each architecture is highly dependent on its application. • Mild, HSD and Plug-in HSD powertrains are the most likely architectures to dominate. - Abstract: The recent introduction of hybrid-electric powertrain technology has disrupted the automotive industry, causing significant powertrain design divergence. As this radical powertrain innovation matures, will hybrid vehicles dominate the future automotive market and does this represent a positive shift in the environmental impact of the industry? The answer to this question is sought within this paper. It seeks to take advantage of the position that the industry has reached, replacing previous theoretical studies with the first extensive empirical models of life cycle emissions and whole-life costing. A comprehensive snapshot of today’s hybrid market is presented, with detailed descriptions of the various hybrid powertrain architectures. Design data has been gathered for 44 hybrid passenger cars currently available in the US. The empirical data is used to explore the relative life cycle greenhouse gas emissions and whole-life costing of different hybrid powertrain architectures. Potential dominant designs are identified and their emissions are shown to be reduced. However, both the emissions and economic competitiveness of different hybrid powertrains are shown to vary significantly depending on how the vehicle is used

  9. Study of emissions and fuel economy for parallel hybrid versus conventional vehicles on real world and standard driving cycles

    Directory of Open Access Journals (Sweden)

    Ahmed Al-Samari

    2017-12-01

    Full Text Available Parallel hybrid electric vehicles (PHEVs increasing rapidly in the automobile markets. However, the benefits out of using this kind of vehicles are still concerned a lot of costumers. This work investigated the expected benefits (such as decreasing emissions and increasing fuel economy from using the parallel HEV in comparison to the conventional vehicle model of the real-world and standard driving cycles. The software Autonomie used in this study to simulate the parallel HEV and conventional models on these driving cycles.The results show that the fuel economy (FE can be improved significantly up to 68% on real-world driving cycle, which is represented mostly city activities. However, the FE improvement was limited (10% on the highway driving cycle, and this is expected since the using of brake system was infrequent. Moreover, the emissions from parallel HEV decreased about 40% on the real-world driving cycle, and decreased 11% on the highway driving cycle. Finally, the engine efficiency, improved about 12% on the real-world driving cycle, and about 7% on highway driving cycle. Keywords: Emissions, Hybrid electric vehicles, Fuel economy, Real-world driving cycle

  10. Life-cycle Economic and Environmental Effects of Green, Gray and Hybrid Stormwater Infrastructure

    Science.gov (United States)

    Stokes-Draut, J. R.; Taptich, M. N.; Horvath, A.

    2016-12-01

    Cities throughout the U.S. are seeking efficient ways to manage stormwater for many reasons, including flood control, pollution management, water supply augmentation and to prepare for a changing climate. Traditionally, cities have relied primarily on gray infrastructure, namely sewers, storage and treatment facilities. In these systems, urban runoff, its volume increasing as impervious surfaces expand, is channeled to a wastewater plant where it is mixed with raw sewage prior to treatment or it is discharged, generally untreated, to local water bodies. These facilities are inflexible and expensive to build and maintain. Many systems are deteriorating and/or approaching, if not exceeding, their design capacity. Increasingly, more innovative approaches that integrate stormwater management into the natural environment and that make sense at both local and regional scales are sought. Identifying the best stormwater solution will require evaluating the life-cycle economic costs associated with these alternatives, including costs associated with construction, operation, and maintenance including regulatory and permitting costs, financing, as well as other indirect costs (e.g., avoided wastewater processing or system capacity expansion, increased property value) and non-economic co-benefits (i.e, aesthetics, habitat provision). Beyond conventional life-cycle costing, applying life-cycle assessment (LCA) will contribute to more holistic and sustainable decision-making. LCA can be used to quantitatively track energy use, greenhouse gas emissions, and other environmental effects associated with constructing, operating, and maintaining green and gray infrastructure, including supply chain contributions. We will present the current state of knowledge for implementing life-cycle costing and LCA into stormwater management decisions for green, gray and hybrid infrastructure.

  11. 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).

  12. Single-Cell Genome and Group-Specific dsrAB Sequencing Implicate Marine Members of the Class Dehalococcoidia (Phylum Chloroflexi) in Sulfur Cycling

    DEFF Research Database (Denmark)

    Wasmund, Kenneth; Cooper, Myriel; Schreiber, Lars

    2016-01-01

    The marine subsurface sediment biosphere is widely inhabited by bacteria affiliated with the class Dehalococcoidia (DEH), phylum Chloroflexi, and yet little is known regarding their metabolisms. In this report, genomic content from a single DEH cell (DEH-C11) with a 16S rRNA gene that was affilia......The marine subsurface sediment biosphere is widely inhabited by bacteria affiliated with the class Dehalococcoidia (DEH), phylum Chloroflexi, and yet little is known regarding their metabolisms. In this report, genomic content from a single DEH cell (DEH-C11) with a 16S rRNA gene...... that was affiliated with a diverse cluster of 16S rRNA gene sequences prevalent in marine sediments was obtained from sediments of Aarhus Bay, Denmark. The distinctive gene content of this cell suggests metabolic characteristics that differ from those of known DEH and Chloroflexi. The presence of genes encoding...... dissimilatory sulfite reductase (Dsr) suggests that DEH could respire oxidized sulfur compounds, although Chloroflexi have never been implicated in this mode of sulfur cycling. Using long-range PCR assays targeting DEH dsr loci, dsrAB genes were amplified and sequenced from various marine sediments. Many...

  13. A dynamic study on the sulfuric acid distillation column for VHTR-assisted hydrogen production systems

    International Nuclear Information System (INIS)

    Youngjoon, Shin; Heesung, Shin; Jiwoon, Jang; Kiyoung, Lee; Jonghwa, Chang

    2007-01-01

    The sulfur-iodine (SI) cycle and the Westinghouse sulfur hybrid cycle coupled to a very high temperature gas-cooled reactor (VHTR) are well known as a feasible technology to produce hydrogen. The concentration of the sulfuric acid solution and its decomposition are essential parts in both cycles. In this paper, the thermophysical properties which are the boiling point, latent heat, and the partial pressures of water, sulfuric acid, and sulfur trioxide have been correlated as a function of the sulfuric acid concentration for the H 2 SO 4 and H 2 O binary chemical system, based on the data in Perry's chemical engineers' hand-book and other experimental data. By using these thermophysical correlations, a dynamic analysis of a sulfuric acid distillation column has been performed to establish the column design requirements and its optimum operation condition. From the results of the dynamic analysis, an optimized column system is anticipated for a distillation column equipped with 2 ideal plates and a second plate feeding system from the bottom plate. The effects of the hold-up of the re-boiler and the reflux ratio from the top product stream on the elapsing time when the system progresses toward a steady state have been analyzed. (authors)

  14. Hybrid Simulation of Duty Cycle Influences on Pulse Modulated RF SiH4/Ar Discharge

    Science.gov (United States)

    Wang, Xifeng; Song, Yuanhong; Zhao, Shuxia; Dai, Zhongling; Wang, Younian

    2016-04-01

    A one-dimensional fluid/Monte-Carlo (MC) hybrid model is developed to describe capacitively coupled SiH4/Ar discharge, in which the lower electrode is applied by a RF source and pulse modulated by a square-wave, to investigate the modulation effects of the pulse duty cycle on the discharge mechanism. An electron Monte Carlo simulation is used to calculate the electron energy distribution as a function of position and time phase. Rate coefficients in chemical reactions can then be obtained and transferred to the fluid model for the calculation of electron temperature and densities of different species, such as electrons, ions, and radicals. The simulation results show that, the electron energy distribution f(ɛ) is modulated evidently within a pulse cycle, with its tail extending to higher energies during the power-on period, while shrinking back promptly in the afterglow period. Thus, the rate coefficients could be controlled during the discharge, resulting in modulation of the species composition on the substrate compared with continuous excitation. Meanwhile, more negative ions, like SiH-3 and SiH-2, may escape to the electrodes owing to the collapse of ambipolar electric fields, which is beneficial to films deposition. Pulse modulation is thus expected to provide additional methods to customize the plasma densities and components. supported by National Natural Science Foundation of China (No. 11275038)

  15. Tomato second cycle hybrids as a source of genetic variability for fruit quality traits

    Directory of Open Access Journals (Sweden)

    Pereira da Costa JH

    2016-11-01

    Full Text Available The objective of this study was to investigate the phenotypic and molecular variability in a F2 generation derived from a SCH (Second Cycle Hybrid in order to detect QTLs for some fruit traits of tomato. Genome coverage at different levels was achieved by three types of molecular markers (polypeptides, sequence-related amplified polymorphism-SRAP and amplified restriction fragment polymorphism - AFLP. Different degrees of polymorphism were detected by SRAP and AFLP at the DNA structure level and also by polypeptides at the DNA expression level. The first two markers, associated with phenotypic variation, detected QTLs involved in important agronomic traits such as fruit shelf life, soluble solids content, pH, and titratable acidity. New gene blocks originated by recombination during the first cycle of crossing were detected. This study confirmed that the observed phenotypic differences represent a new gene rearrangement and that these new gene blocks are responsible for the presence of the genetic variability detected for these traits.

  16. Water conservation implications for decarbonizing non-electric energy supply: A hybrid life-cycle analysis.

    Science.gov (United States)

    Liu, Shiyuan; Wang, Can; Shi, Lei; Cai, Wenjia; Zhang, Lixiao

    2018-08-01

    Low-carbon transition in the non-electric energy sector, which includes transport and heating energy, is necessary for achieving the 2 °C target. Meanwhile, as non-electric energy accounts for over 60% of total water consumption in the energy supply sector, it is vital to understand future water trends in the context of decarbonization. However, few studies have focused on life-cycle water impacts for non-electric energy; besides, applying conventional LCA methodology to assess non-electric energy has limitations. In this paper, a Multi-Regional Hybrid Life-Cycle Assessment (MRHLCA) model is built to assess total CO 2 emissions and water consumption of 6 non-electric energy technologies - transport energy from biofuel and gasoline, heat supply from natural gas, biogas, coal, and residual biomass, within 7 major emitting economies. We find that a shift to natural gas and residual biomass heating can help economies reduce 14-65% CO 2 and save more than 21% water. However, developed and developing economies should take differentiated technical strategies. Then we apply scenarios from IMAGE model to demonstrate that if economies take cost-effective 2 °C pathways, the water conservation synergy for the whole energy supply sector, including electricity, can also be achieved. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. Enhancements to the hybrid pressurized air receiver (HPAR) concept in the SUNDISC cycle

    Science.gov (United States)

    Heller, Lukas; Hoffmann, Jaap

    2017-06-01

    A dual-pressure air receiver has previously been proposed as part of a hybrid receiver system preheating pressurized air in a solarized gas turbine and providing hot non-pressurized air to power the bottoming cycle of a combined cycle CSP plant. The receiver, based on a bundle of metallic tubular absorbers, was found to not be able to provide the non-pressurized air at the required temperature. Three enhancements to the basic design are presented and thermally modeled: (a) Finned absorber tubes to increase the convective heat transfer, (b) quartz glass elements to alleviate convective losses and improve the flow inside the tube bundle as well as (c) additional absorber elements behind the tube bundle. It could be shown that finned absorber tubes as well as the additional absorber elements have potential to improve the thermal performance of the receiver while a quartz glass window and flow-enhancing quartz elements could be indispensable additions to either of the other enhancements.

  18. Life cycle cost of a hybrid forward osmosis – low pressure reverse osmosis system for seawater desalination and wastewater recovery

    KAUST Repository

    Valladares Linares, Rodrigo; Li, Z.; Yangali-Quintanilla, V.; Ghaffour, NorEddine; Amy, Gary L.; Leiknes, TorOve; Vrouwenvelder, Johannes S.

    2015-01-01

    -RO-AOP) for wastewater treatment and reuse. The most important variables affecting economic feasibility are obtained through a sensitivity analysis of a hybrid FO-LPRO system. The main parameters taken into account for the life cycle costs are the water quality

  19. Traffic sounds and cycling safety : the use of electronic devices by cyclists and the quietness of hybrid and electric cars.

    NARCIS (Netherlands)

    Stelling-Konczak, A. Hagenzieker, M.P. & Wee, B. van

    2015-01-01

    The growing popularity of electric devices and the increasing number of hybrid and electric cars have recently raised concerns about the use of auditory signals by vulnerable road users. This paper consolidates current knowledge about the two trends in relation to cycling safety. Both a literature

  20. Development of a hybrid energy storage sizing algorithm associated with the evaluation of power management in different driving cycles

    International Nuclear Information System (INIS)

    Masoud, Masih Tehrani; Mohammad Reza, Ha'iri Yazdi; Esfahanian, Vahid; Sagha, Hossein

    2012-01-01

    In this paper, a hybrid energy storage sizing algorithm for electric vehicles is developed to achieve a semi optimum cost effective design. Using the developed algorithm, a driving cycle is divided into its micro-trips and the power and energy demands in each micro trip are determined. The battery size is estimated because the battery fulfills the power demands. Moreover, the ultra capacitor (UC) energy (or the number of UC modules) is assessed because the UC delivers the maximum energy demands of the different micro trips of a driving cycle. Finally, a design factor, which shows the power of the hybrid energy storage control strategy, is utilized to evaluate the newly designed control strategies. Using the developed algorithm, energy saving loss, driver satisfaction criteria, and battery life criteria are calculated using a feed forward dynamic modeling software program and are utilized for comparison among different energy storage candidates. This procedure is applied to the hybrid energy storage sizing of a series hybrid electric city bus in Manhattan and to the Tehran driving cycle. Results show that a higher aggressive driving cycle (Manhattan) requires more expensive energy storage system and more sophisticated energy management strategy

  1. Recent developments in thermally-driven seawater desalination: Energy efficiency improvement by hybridization of the MED and AD cycles

    KAUST Repository

    Ng, Kim Choon

    2015-01-01

    The energy, water and environment nexus is a crucial factor when considering the future development of desalination plants or industry in the water-stressed economies. New generation of desalination processes or plants has to meet the stringent environment discharge requirements and yet the industry remains highly energy efficient and sustainable when producing good potable water. Water sources, either brackish or seawater, have become more contaminated as feed while the demand for desalination capacities increase around the world. One immediate solution for energy efficiency improvement comes from the hybridization of the proven desalination processes to the newer processes of desalination: For example, the integration of the available thermally-driven to adsorption desalination (AD) cycles where significant thermodynamic synergy can be attained when cycles are combined. For these hybrid cycles, a quantum improvement in energy efficiency as well as in increase in water production can be expected. The advent of MED with AD cycles, or simply called the MEDAD cycles, is one such example where seawater desalination can be pursued and operated in cogeneration with the electricity production plants: The hybrid desalination cycles utilize only the low exergy bled-steam at low temperatures, complemented with waste exhaust or renewable solar thermal heat at temperatures between 60 and 80. °C. In this paper, the authors have reported their pioneered research on aspects of AD and related hybrid MEDAD cycles, both at theoretical models and experimental pilots. Using the cogeneration of electricity and desalination concept, the authors examined the cost apportionment of fuel cost by the quality or exergy of working steam for such cogeneration configurations.

  2. Low CO2-emissions hybrid solar combined-cycle power system with methane membrane reforming

    International Nuclear Information System (INIS)

    Li, Yuanyuan; Zhang, Na; Cai, Ruixian

    2013-01-01

    Based on the principle of cascade utilization of multiple energy resources, a gas-steam combined cycle power system integrated with solar thermo-chemical fuel conversion and CO 2 capture has been proposed and analyzed. The collected solar heat at 550 °C drives the endothermic methane reforming and is converted to the produced syngas chemical exergy, and then released as high-temperature thermal energy via combustion for power generation, achieving its high-efficiency heat-power conversion. The reforming reaction is integrated with a hydrogen separation membrane, which continuously withdraws hydrogen from the reaction zone and enables nearly full methane conversion. The CO 2 enriched gas being concentrated in the retentate zone is collected and processed with pre-combustion decarbonization. The system is thermodynamically simulated using the ASPEN PLUS code. The results show that with 91% CO 2 captured, the specific CO 2 emission is 25 g/kWh. An exergy efficiency of 58% and thermal efficiency of 51.6% can be obtained. A fossil fuel saving ratio of 31.2% is achievable with a solar thermal share of 28.2%, and the net solar-to-electricity efficiency based on the gross solar heat incident on the collector is about 36.4% compared with the same gas-steam combined cycle system with an equal CO 2 removal ratio obtained by post-combustion decarbonization. - Highlights: ► A solar-assisted hybrid combined cycle power system has been proposed and analyzed. ► The system integrates power generation with solar-driven reforming and CO 2 capture. ► solar heat upgrading and high-efficiency heat-to-power conversion are achieved. ► membrane reforming enables high CH 4 conversion and pre-combustion CO 2 capture. ► The system thermodynamic performances have been investigated and compared

  3. A stable organic-inorganic hybrid layer protected lithium metal anode for long-cycle lithium-oxygen batteries

    Science.gov (United States)

    Zhu, Jinhui; Yang, Jun; Zhou, Jingjing; Zhang, Tao; Li, Lei; Wang, Jiulin; Nuli, Yanna

    2017-10-01

    A stable organic-inorganic hybrid layer (OIHL) is direct fabricated on lithium metal surface by the interfacial reaction of lithium metal foil with 1-chlorodecane and oxygen/carbon dioxide mixed gas. This favorable OIHL is approximately 30 μm thick and consists of lithium alkyl carbonate and lithium chloride. The lithium-oxygen batteries with OIHL protected lithium metal anode exhibit longer cycle life (340 cycles) than those with bare lithium metal anode (50 cycles). This desirable performance can be ascribed to the robust OIHL which prevents the growth of lithium dendrites and the corrosion of lithium metal.

  4. Experimental study of a thermochemical compressor for an absorption/compression hybrid cycle

    International Nuclear Information System (INIS)

    Ventas, R.; Vereda, C.; Lecuona, A.; Venegas, M.

    2012-01-01

    Highlights: ► Experimental study of a thermochemical compressor for absorption/compression cycle. ► Spray adiabatic absorber using NH 3 –LiNO 3 solution working fluid. ► It is able to operate between 57 and 110 °C varying concentration between 0.46 and 0.59. ► The increase of absorber pressure decreases the circulation ratio. ► The numerical model performed agrees with the experimental results. -- Abstract: An experimental study of a thermochemical compressor with ammonia–lithium nitrate solution as working fluid has been carried out. This compressor incorporates a single-pass adiabatic absorber and all the heat exchangers are of the plate type: absorber subcooler, generator and solution heat exchanger. The thermochemical compressor has been studied as part of a single-effect absorption chiller hybridized with an in-series low-pressure compression booster. The adiabatic absorber uses fog jet injectors. The generator hot water temperatures for the external driving flow are in the range of 57–110 °C and the absorber pressures range between 429 and 945 kPa. Experimental results are compared with a numerical model showing a high agreement. The performance of the thermochemical compressor, evaluated through the circulation ratio, improves for higher absorber pressures, indicating the potential of pressure boosting. For the same circulation ratio, the driving hot water inlet temperature decreases with the rise of the absorber pressure. The thermochemical compressor, based on an adiabatic absorber, can produce refrigerant with very low driving temperatures, between 57 and 70 °C, what is interesting for solar cooling applications and very low temperature residual heat recovery. Efficiencies and cooling power are offered when this hybrid thermochemical compressor is implemented in a chiller, showing the effect of different operating parameters.

  5. CONCEPTUAL DESIGN AND ECONOMICS OF THE ADVANCED CO2 HYBRID POWER CYCLE

    Energy Technology Data Exchange (ETDEWEB)

    A. Nehrozoglu

    2004-12-01

    Research has been conducted under United States Department of Energy Contract DEFC26-02NT41621 to analyze the feasibility of a new type of coal-fired plant for electric power generation. This new type of plant, called the Advanced CO{sub 2} Hybrid Power Plant, offers the promise of efficiencies nearing 36 percent, while concentrating CO{sub 2} for 100% sequestration. Other pollutants, such as SO{sub 2} and NOx, are sequestered along with the CO{sub 2} yielding a zero emissions coal plant. The CO{sub 2} Hybrid is a gas turbine-steam turbine combined cycle plant that uses CO{sub 2} as its working fluid to facilitate carbon sequestration. The key components of the plant are a cryogenic air separation unit (ASU), a pressurized circulating fluidized bed gasifier, a CO{sub 2} powered gas turbine, a circulating fluidized bed boiler, and a super-critical pressure steam turbine. The gasifier generates a syngas that fuels the gas turbine and a char residue that, together with coal, fuels a CFB boiler to power the supercritical pressure steam turbine. Both the gasifier and the CFB boiler use a mix of ASU oxygen and recycled boiler flue gas as their oxidant. The resulting CFB boiler flue gas is essentially a mixture of oxygen, carbon dioxide and water. Cooling the CFB flue gas to 80 deg. F condenses most of the moisture and leaves a CO{sub 2} rich stream containing 3%v oxygen. Approximately 30% of this flue gas stream is further cooled, dried, and compressed for pipeline transport to the sequestration site (the small amount of oxygen in this stream is released and recycled to the system when the CO{sub 2} is condensed after final compression and cooling). The remaining 70% of the flue gas stream is mixed with oxygen from the ASU and is ducted to the gas turbine compressor inlet. As a result, the gas turbine compresses a mixture of carbon dioxide (ca. 64%v) and oxygen (ca. 32.5%v) rather than air. This carbon dioxide rich mixture then becomes the gas turbine working fluid and

  6. The enigmatic SAR202 cluster up close: shedding light on a globally distributed dark ocean lineage involved in sulfur cycling.

    Science.gov (United States)

    Mehrshad, Maliheh; Rodriguez-Valera, Francisco; Amoozegar, Mohammad Ali; López-García, Purificación; Ghai, Rohit

    2018-03-01

    The dark ocean microbiota represents the unknown majority in the global ocean waters. The SAR202 cluster belonging to the phylum Chloroflexi was the first microbial lineage discovered to specifically inhabit the aphotic realm, where they are abundant and globally distributed. The absence of SAR202 cultured representatives is a significant bottleneck towards understanding their metabolic capacities and role in the marine environment. In this work, we use a combination of metagenome-assembled genomes from deep-sea datasets and publicly available single-cell genomes to construct a genomic perspective of SAR202 phylogeny, metabolism and biogeography. Our results suggest that SAR202 cluster members are medium sized, free-living cells with a heterotrophic lifestyle, broadly divided into two distinct clades. We present the first evidence of vertical stratification of these microbes along the meso- and bathypelagic ocean layers. Remarkably, two distinct species of SAR202 cluster are highly abundant in nearly all deep bathypelagic metagenomic datasets available so far. SAR202 members metabolize multiple organosulfur compounds, many appear to be sulfite-oxidizers and are predicted to play a major role in sulfur turnover in the dark water column. This concomitantly suggests an unsuspected availability of these nutrient sources to allow for the high abundance of these microbes in the deep sea.

  7. 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.

  8. Total environmental impacts of biofuels from corn stover using a hybrid life cycle assessment model combining process life cycle assessment and economic input-output life cycle assessment.

    Science.gov (United States)

    Liu, Changqi; Huang, Yaji; Wang, Xinye; Tai, Yang; Liu, Lingqin; Liu, Hao

    2018-01-01

    Studies on the environmental analysis of biofuels by fast pyrolysis and hydroprocessing (BFPH) have so far focused only on the environmental impacts from direct emissions and have included few indirect emissions. The influence of ignoring some indirect emissions on the environmental performance of BFPH has not been well investigated and hence is not really understood. In addition, in order to avoid shifting environmental problems from one medium to another, a comprehensive assessment of environmental impacts caused by the processes must quantify the environmental emissions to all media (air, water, and land) in relation to each life cycle stage. A well-to-wheels assessment of the total environmental impacts resulting from direct emissions and indirect emissions of a BFPH system with corn stover is conducted using a hybrid life cycle assessment (LCA) model combining the economic input-output LCA and the process LCA. The Tool for the Reduction and Assessment of Chemical and other environmental Impacts (TRACI) has been used to estimate the environmental impacts in terms of acidification, eutrophication, global climate change, ozone depletion, human health criteria, photochemical smog formation, ecotoxicity, human health cancer, and human health noncancer caused by 1 MJ biofuel production. Taking account of all the indirect greenhouse gas (GHG) emissions, the net GHG emissions (81.8 g CO 2 eq/MJ) of the biofuels are still less than those of petroleum-based fuels (94 g CO 2 eq/MJ). Maize production and pyrolysis and hydroprocessing make major contributions to all impact categories except the human health criteria. All impact categories resulting from indirect emissions except eutrophication and smog air make more than 24% contribution to the total environmental impacts. Therefore, the indirect emissions are important and cannot be ignored. Sensitivity analysis has shown that corn stover yield and bio-oil yield affect the total environmental impacts of the biofuels

  9. Parametric analysis of blade configurations for a small-scale nitrogen axial expander with hybrid open-Rankine cycle

    International Nuclear Information System (INIS)

    Khalil, Khalil M.; Mahmoud, S.; Al- Dadah, R.K.; AL-Mousawi, Fadhel

    2017-01-01

    Highlights: • Develop cryogenic energy storage and efficient recovery technologies. • Integrate small scale closed and cryogenic open-Rankine cycles. • Investigate blade configuration on small-scale axial expander performance. • Use mean line and 3D CFD simulation for expander robust design procedure. • Predict effects of expander efficiency on hybrid open-Rankine cycle efficiency. - Abstract: During the last few decades, low-grade energy sources such as solar energy and wind energy have enhanced the efficiency of the advanced renewable technologies such as the combined Rankine. Furthermore, these heat sources have contributed to a reduction in CO2 emissions. To address the problem of the intermittent nature of such renewable sources, energy storage technologies have been used to balance the power demand and smooth out energy production. In this study, the direct expansion cycle (open Rankine cycle) is combined with a closed loop Rankine cycle to generate power more efficiently and address the problem of discontinuous renewable sources. The topping cycle of this system is a closed looped Rankine cycle and propane is used as a hydrocarbon fluid, while the direct expansion cycle is considered to be the bottoming cycle utilizing nitrogen as cryogen fluid. Small-scale expanders are the most important parts in many thermal power cycles, such as the Rankine cycle, due to the significant impact on the overall cycle’s efficiency. This work investigated the effect of using a number of blade configurations on the cycle’s performance using a small-scale axial expander. A three-dimensional Computational Fluid Dynamic (CFD) simulation was used to examine four proposed blade configurations (lean, sweep, twist, bowl) with three hub- tip ratios (0.83, 0.75, 0.66). In addition, a numerical simulation model of the hybrid open expansion- Rankine cycle was designed and modeled in order to estimate the cycle’s performance. The results show that when the expander

  10. Energy conversion efficiency of hybrid electric heavy-duty vehicles operating according to diverse drive cycles

    Energy Technology Data Exchange (ETDEWEB)

    Banjac, Titina [AVL-AST d.o.o., Trg Leona Stuklja 5, SI-2000 Maribor (Slovenia); Trenc, Ferdinand; Katrasnik, Tomaz [Faculty of Mechanical Engineering, Univ. of Ljubljana, Askerceva 6, SI-1000 Ljubljana (Slovenia)

    2009-12-15

    Energy consumption and exhaust emissions of hybrid electric vehicles (HEVs) strongly depend on the HEV topology, power ratios of their components and applied control strategy. Combined analytical and simulation approach was applied to analyze energy conversion efficiency of different HEV topologies. Analytical approach is based on the energy balance equations and considers all energy paths in the HEVs from the energy sources to the wheels and to other energy sinks. Simulation approach is based on a fast forward-facing simulation model for simulating parallel and series HEVs as well as for conventional internal combustion engine vehicles, and considers all components relevant for modeling energy conversion phenomena. Combined approach enables evaluation of energy losses on different energy paths and provides their impact on the fuel economy. It therefore enables identification of most suitable HEV topology and of most suitable power ratios of the components for targeted vehicle application, since it reveals and quantifies the mechanisms that could lead to improved energy conversion efficiency of particular HEV. The paper exposes characteristics of the test cycles that lead to improved energy conversion efficiency of HEVs. Mechanisms leading to improved fuel economy of parallel HEVs through drive-away and vehicle propulsion at low powertrain loads by electric motor are also analyzed. It was also shown that control strategies managing energy flow through electric storage devices significantly influence energy conversion efficiency of series HEVs. (author)

  11. Comparative Evaluation of Biomass Power Generation Systems in China Using Hybrid Life Cycle Inventory Analysis

    Science.gov (United States)

    Liu, Huacai; Yin, Xiuli; Wu, Chuangzhi

    2014-01-01

    There has been a rapid growth in using agricultural residues as an energy source to generate electricity in China. Biomass power generation (BPG) systems may vary significantly in technology, scale, and feedstock and consequently in their performances. A comparative evaluation of five typical BPG systems has been conducted in this study through a hybrid life cycle inventory (LCI) approach. Results show that requirements of fossil energy savings, and greenhouse gas (GHG) emission reductions, as well as emission reductions of SO2 and NOx, can be best met by the BPG systems. The cofiring systems were found to behave better than the biomass-only fired system and the biomass gasification systems in terms of energy savings and GHG emission reductions. Comparing with results of conventional process-base LCI, an important aspect to note is the significant contribution of infrastructure, equipment, and maintenance of the plant, which require the input of various types of materials, fuels, services, and the consequent GHG emissions. The results demonstrate characteristics and differences of BPG systems and help identify critical opportunities for biomass power development in China. PMID:25383383

  12. Nutrients removal in hybrid fluidised bed bioreactors operated with aeration cycles.

    Science.gov (United States)

    Martin, Martin; Enríquez, L López; Fernández-Polanco, M; Villaverde, S; Garcia-Encina, P A

    2007-01-01

    Abstract Two hybrid fluidised bed reactors filled with sepiolite and granular activated carbon (GAC) were operated with short cycled aeration for removing organic matter, total nitrogen and phosphorous, respectively. Both reactors were continuously operated with synthetic and/or industrial wastewater containing 350-500 mg COD/L, 110-130 mg NKT/L, 90-100 mg NH3-N/L and 12-15 mg P/L for 8 months. The reactor filled with sepiolite, treating only synthetic wastewater, removed COD, ammonia, total nitrogen and phosphorous up to 88, 91, 55 and 80% with a hydraulic retention time (HRT) of 10 h, respectively. These efficiencies correspond to removal rates of 0.95 kgCODm(-3)d(-1) and 0.16 kg total N m(-3)d(-1). The reactor filled with GAC was operated for 4 months with synthetic wastewater and 4 months with industrial wastewater, removing 98% of COD, 96% of ammonia, and 66% of total nitrogen, with an HRT of 13.6 h. No significant phosphorous removing activity was observed in this reactor. Microbial communities growing with both reactors were followed using polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE) techniques. The microbial fingerprints, i.e. DGGE profiles, indicated that biological communities in both reactors were stable along the operational period even when the operating conditions were changed.

  13. Comparative Evaluation of Biomass Power Generation Systems in China Using Hybrid Life Cycle Inventory Analysis

    Directory of Open Access Journals (Sweden)

    Huacai Liu

    2014-01-01

    Full Text Available There has been a rapid growth in using agricultural residues as an energy source to generate electricity in China. Biomass power generation (BPG systems may vary significantly in technology, scale, and feedstock and consequently in their performances. A comparative evaluation of five typical BPG systems has been conducted in this study through a hybrid life cycle inventory (LCI approach. Results show that requirements of fossil energy savings, and greenhouse gas (GHG emission reductions, as well as emission reductions of SO2 and NOx, can be best met by the BPG systems. The cofiring systems were found to behave better than the biomass-only fired system and the biomass gasification systems in terms of energy savings and GHG emission reductions. Comparing with results of conventional process-base LCI, an important aspect to note is the significant contribution of infrastructure, equipment, and maintenance of the plant, which require the input of various types of materials, fuels, services, and the consequent GHG emissions. The results demonstrate characteristics and differences of BPG systems and help identify critical opportunities for biomass power development in China.

  14. The effects of hybrid cycle training in inactive people with long-term spinal cord injury : design of a multicenter randomized controlled trial

    NARCIS (Netherlands)

    Bakkum, Arjan J. T.; de Groot, Sonja; van der Woude, Lucas H. V.; Janssen, Thomas W. J.

    2013-01-01

    Purpose: Physical activity in people with long-term spinal cord injury (SCI) is important to stay fit and healthy. The purpose of this study is to evaluate the effects of hybrid cycle training (hand cycling in combination with functional electrical stimulation-induced leg cycling) on fitness,

  15. The shift of microbial communities and their roles in sulfur and iron cycling in a copper ore bioleaching system

    Science.gov (United States)

    Niu, Jiaojiao; Deng, Jie; Xiao, Yunhua; He, Zhili; Zhang, Xian; van Nostrand, J. D.; Liang, Yili; Deng, Ye; Liu, Xueduan; Yin, Huaqun

    2016-10-01

    Bioleaching has been employed commercially to recover metals from low grade ores, but the production efficiency remains to be improved due to limited understanding of the system. This study examined the shift of microbial communities and S&Fe cycling in three subsystems within a copper ore bioleaching system: leaching heap (LH), leaching solution (LS) and sediment under LS. Results showed that both LH and LS had higher relative abundance of S and Fe oxidizing bacteria, while S and Fe reducing bacteria were more abundant in the Sediment. GeoChip analysis showed a stronger functional potential for S0 oxidation in LH microbial communities. These findings were consistent with measured oxidation activities to S0 and Fe2+, which were highest by microbial communities from LH, lower by those from LS and lowest form Sediment. Moreover, phylogenetic molecular ecological network analysis indicated that these differences might be related to interactions among microbial taxa. Last but not the least, a conceptual model was proposed, linking the S&Fe cycling with responsible microbial populations in the bioleaching systems. Collectively, this study revealed the microbial community and functional structures in all three subsystems of the copper ore, and advanced a holistic understanding of the whole bioleaching system.

  16. 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.

  17. Carbon and energy footprints of electric delivery trucks:a hybrid multi-regional input-output life cycle assessment

    OpenAIRE

    Zhao, Yang; Onat, Nuri Cihat; Küçükvar, Murat; Tatari, Ömer

    2016-01-01

    Due to frequent stop-and-go operation and long idling periods when driving in congested urban areas, the electrification of commercial delivery trucks has become an interesting topic nationwide. In this study, environmental impacts of various alternative delivery trucks including battery electric, diesel, diesel-electric hybrid, and compressed natural gas trucks are analyzed. A novel life cycle assessment method, an environmentally-extended multi-region input-output analysis, is utilized to c...

  18. Characterization of chemosynthetic microbial mats associated with intertidal hydrothermal sulfur vents in White Point, San Pedro, CA, USA

    Directory of Open Access Journals (Sweden)

    Priscilla J Miranda

    2016-07-01

    Full Text Available The shallow-sea hydrothermal vents at White Point (WP in Palos Verdes (PV on the southern California coast support microbial mats and provide easily accessed settings in which to study chemolithoautotrophic sulfur cycling. Previous studies have cultured sulfur-oxidizing bacteria from the WP mats; however, almost nothing is known about the in situ diversity and activity of the microorganisms in these habitats. We studied the diversity, micron-scale spatial associations and metabolic activity of the mat community via sequence analysis of 16S rRNA and aprA genes, Fluorescence in situ Hybridization (FISH microscopy and sulfate-reduction rate (SRR measurements. Sequence analysis revealed a diverse group of bacteria, dominated by sulfur cycling gamma-, epsilon- and deltaproteobacterial lineages such as Marithrix, Sulfurovum and Desulfuromusa. FISH microscopy suggests a close physical association between sulfur-oxidizing and sulfur-reducing genotypes, while radiotracer studies showed low, but detectable, SRR. Comparative 16S rRNA gene sequence analyses indicate the WP sulfur vent microbial mat community is similar, but distinct from other hydrothermal vent communities representing a range of biotopes and lithologic settings. These findings suggest a complete biological sulfur cycle is operating in the WP mat ecosystem mediated by diverse bacterial lineages, with some similarity with deep-sea hydrothermal vent communities.

  19. PLUG-IN HYBRID ELECTRIC VEHICLE AND HYBRID ELECTRIC VEHICLE EMISSIONS UNDER FTP AND US06 CYCLES AT HIGH, AMBIENT, AND LOW TEMPERATURES

    Energy Technology Data Exchange (ETDEWEB)

    Seidman, M.R.; Markel, T.

    2008-01-01

    The concept of a Plug-in Hybrid Electric Vehicle (PHEV) is to displace consumption of gasoline by using electricity from the vehicle’s large battery pack to power the vehicle as much as possible with minimal engine operation. This paper assesses the PHEV emissions and operation. Currently, testing of vehicle emissions is done using the federal standard FTP4 cycle on a dynamometer at ambient (75°F) temperatures. Research was also completed using the US06 cycle. Furthermore, research was completed at high (95°F) and low (20°F) temperatures. Initial dynamometer testing was performed on a stock Toyota Prius under the standard FTP4 cycle, and the more demanding US06 cycle. Each cycle was run at 95°F, 75°F, and 20°F. The testing was repeated with the same Prius retrofi tted with an EnergyCS Plug-in Hybrid Electric system. The results of the testing confi rm that the stock Prius meets Super-Ultra Low Emission Vehicle requirements under current testing procedures, while the PHEV Prius under current testing procedures were greater than Super-Ultra Low Emission Vehicle requirements, but still met Ultra Low Emission Vehicle requirements. Research points to the catalyst temperature being a critical factor in meeting emission requirements. Initial engine emissions pass through with minimal conversion until the catalyst is heated to typical operating temperatures of 300–400°C. PHEVs also have trouble maintaining the minimum catalyst temperature throughout the entire test because the engine is turned off when the battery can support the load. It has been observed in both HEVs and PHEVs that the catalyst is intermittently unable to reduce nitrogen oxide emissions, which causes further emission releases. Research needs to be done to combat the initial emission spikes caused by a cold catalyst. Research also needs to be done to improve the reduction of nitrogen oxides by the catalyst system.

  20. Hybrid System Modeling and Full Cycle Operation Analysis of a Two-Stroke Free-Piston Linear Generator

    Directory of Open Access Journals (Sweden)

    Peng Sun

    2017-02-01

    Full Text Available Free-piston linear generators (FPLGs have attractive application prospects for hybrid electric vehicles (HEVs owing to their high-efficiency, low-emissions and multi-fuel flexibility. In order to achieve long-term stable operation, the hybrid system design and full-cycle operation strategy are essential factors that should be considered. A 25 kW FPLG consisting of an internal combustion engine (ICE, a linear electric machine (LEM and a gas spring (GS is designed. To improve the power density and generating efficiency, the LEM is assembled with two modular flat-type double-sided PM LEM units, which sandwich a common moving-magnet plate supported by a middle keel beam and bilateral slide guide rails to enhance the stiffness of the moving plate. For the convenience of operation processes analysis, the coupling hybrid system is modeled mathematically and a full cycle simulation model is established. Top-level systemic control strategies including the starting, stable operating, fault recovering and stopping strategies are analyzed and discussed. The analysis results validate that the system can run stably and robustly with the proposed full cycle operation strategy. The effective electric output power can reach 26.36 kW with an overall system efficiency of 36.32%.

  1. Dynamic simulation of a fuel cell hybrid vehicle during the federal test procedure-75 driving cycle

    International Nuclear Information System (INIS)

    Kang, Sanggyu; Min, Kyoungdoug

    2016-01-01

    Highlights: • Development of a FCHV dynamic model. • Integration of a PEMFC system dynamic model with the electric vehicle model. • Investigation of the dynamic behavior of the FCEV and PEMFC system during FTP-75. • Capturing the dynamic correlation among components in PEMFC system during FTP-75. - Abstract: The dynamic behavior of a proton exchange membrane fuel cell (PEMFC) system is a crucial factor to ensure the safe and effective operation of fuel cell hybrid vehicles (FCHVs). Specifically, water and thermal management are critical to stabilize the performance of the PEMFC during severe load changes. In the present study, the FCHV dynamic model is developed. The dynamic model of the PEMFC system developed by Matlab–Simulink® is integrated into the electric vehicle model embedded in the Amesim®. The dynamic model of the PEMFC system is composed of a PEMFC stack, an air feeding system, and a thermal management system (TMS). The component models of PEMFC, a shell-and-tube gas-to-gas membrane humidifier, and a heat exchanger are validated via a comparison with the experimental data. The FCHV model is simulated during a federal test procedure (FTP)-75 driving cycle. One system configuration and control strategy is adopted to attain optimal water and thermal management in the PEMFC system. The vehicle speed obtained from the FCHV model aptly tracks the target velocity profile of the FTP-75 cycle within an error of ±0.5%. The dynamic behavior and correlation of each component in the PEMFC system is investigated. The mass and heat transfer in the PEMFC, a humidifier, and a heat exchanger are resolved to determine the species concentration and the temperature more accurately with discretization in the flow’s perpendicular direction. Discretization in the flow parallel direction of humidifier and heat exchanger model makes it possible to capture the distribution of the characteristics. The present model can be used to attain the optimization of the system

  2. Sulfate reduction and methane oxidation activity below the sulfate-methane transition zone in Alaskan Beaufort Sea continental margin sediments: Implications for deep sulfur cycling

    Science.gov (United States)

    Treude, Tina; Krause, Stefan; Maltby, Johanna; Dale, Andrew W.; Coffin, Richard; Hamdan, Leila J.

    2014-11-01

    Two ∼6 m long sediment cores were collected along the ∼300 m isobath on the Alaskan Beaufort Sea continental margin. Both cores showed distinct sulfate-methane transition zones (SMTZ) at 105 and 120 cm below seafloor (cmbsf). Sulfate was not completely depleted below the SMTZ but remained between 30 and 500 μM. Sulfate reduction and anaerobic oxidation of methane (AOM) determined by radiotracer incubations were active throughout the methanogenic zone. Although a mass balance could not explain the source of sulfate below the SMTZ, geochemical profiles and correlation network analyses of biotic and abiotic data suggest a cryptic sulfur cycle involving iron, manganese and barite. Inhibition experiments with molybdate and 2-bromoethanesulfonate (BES) indicated decoupling of sulfate reduction and AOM and competition between sulfate reducers and methanogens for substrates. While correlation network analyses predicted coupling of AOM to iron reduction, the addition of manganese or iron did not stimulate AOM. Since none of the classical archaeal anaerobic methanotrophs (ANME) were abundant, the involvement of unknown or unconventional phylotypes in AOM is conceivable. The resistance of AOM activity to inhibitors implies deviation from conventional enzymatic pathways. This work suggests that the classical redox cascade of electron acceptor utilization based on Gibbs energy yields does not always hold in diffusion-dominated systems, and instead biotic processes may be more strongly coupled to mineralogy.

  3. Seagrass (Zostera marina) Colonization Promotes the Accumulation of Diazotrophic Bacteria and Alters the Relative Abundances of Specific Bacterial Lineages Involved in Benthic Carbon and Sulfur Cycling.

    Science.gov (United States)

    Sun, Feifei; Zhang, Xiaoli; Zhang, Qianqian; Liu, Fanghua; Zhang, Jianping; Gong, Jun

    2015-10-01

    Seagrass colonization changes the chemistry and biogeochemical cycles mediated by microbes in coastal sediments. In this study, we molecularly characterized the diazotrophic assemblages and entire bacterial community in surface sediments of a Zostera marina-colonized coastal lagoon in northern China. Higher nitrogenase gene (nifH) copy numbers were detected in the sediments from the vegetated region than in the sediments from the unvegetated region nearby. The nifH phylotypes detected were mostly affiliated with the Geobacteraceae, Desulfobulbus, Desulfocapsa, and Pseudomonas. Redundancy analysis based on terminal restriction fragment length polymorphism analysis showed that the distribution of nifH genotypes was mostly shaped by the ratio of total organic carbon to total organic nitrogen, the concentration of cadmium in the sediments, and the pH of the overlying water. High-throughput sequencing and phylogenetic analyses of bacterial 16S rRNA genes also indicated the presence of Geobacteraceae and Desulfobulbaceae phylotypes in these samples. A comparison of these results with those of previous studies suggests the prevalence and predominance of iron(III)-reducing Geobacteraceae and sulfate-reducing Desulfobulbaceae diazotrophs in coastal sedimentary environments. Although the entire bacterial community structure was not significantly different between these two niches, Desulfococcus (Deltaproteobacteria) and Anaerolineae (Chloroflexi) presented with much higher proportions in the vegetated sediments, and Flavobacteriaceae (Bacteroidetes) occurred more frequently in the bare sediments. These data suggest that the high bioavailability of organic matter (indicated by relatively lower carbon-to-nitrogen ratios) and the less-reducing anaerobic condition in vegetated sediments may favor Desulfococcus and Anaerolineae lineages, which are potentially important populations in benthic carbon and sulfur cycling in the highly productive seagrass ecosystem. Copyright © 2015

  4. Performance comparison of two low-CO2 emission solar/methanol hybrid combined cycle power systems

    International Nuclear Information System (INIS)

    Li, Yuanyuan; Zhang, Na; Lior, Noam

    2015-01-01

    Highlights: • Two novel solar hybrid combined cycle systems have been proposed and analyzed. • The power systems integrate solar-driven thermo-chemical conversion and CO 2 capture. • Exergy efficiency of about 55% and specific CO 2 emissions of 34 g/kW h are predicted. • Systems CO 2 emissions are 36.8% lower compared to a combined cycle with CO 2 capture. • The fossil fuel demand is ∼30% lower with a solar share of ∼20%. - Abstract: Two novel hybrid combined cycle power systems that use solar heat and methanol, and integrate CO 2 capture, are proposed and analyzed, one based on solar-driven methanol decomposition and the other on solar-driven methanol reforming. The high methanol conversion rates at relatively low temperatures offer the advantage of using the solar heat at only 200–300 °C to drive the syngas production by endothermic methanol conversions and its conversion to chemical energy. Pre-combustion decarbonization is employed to produce CO 2 -free fuel from the fully converted syngas, which is then burned to produce heat at the high temperature for power generation in the proposed advanced combined cycle systems. To improve efficiency, the systems’ configurations were based on the principle of cascade use of multiple heat sources of different temperatures. The thermodynamic performance of the hybrid power systems at its design point is simulated and evaluated. The results show that the hybrid systems can attain an exergy efficiency of about 55%, and specific CO 2 emissions as low as 34 g/kW h. Compared to a gas/steam combined cycle with flue gas CO 2 capture, the proposed solar-assisted system CO 2 emissions are 36.8% lower, and a fossil fuel saving ratio of ∼30% is achievable with a solar thermal share of ∼20%. The system integration predicts high efficiency conversion of solar heat and low-energy-penalty CO 2 capture, with the additional advantage that solar heat is at relatively low temperature where its collection is cheaper and

  5. Effect of salinity on carbon and sulfur cycles in Umm Alhool sabkha microbial mat ecosystem in Qatar

    KAUST Repository

    Alnajjar, Mohammad Ahmad

    2012-10-19

    Microbial mats are only present under extreme conditions, where grazing by higher organisms is limited. Therefore, microbial mats may provide insight into extraterrestrial life, due to their adaptations to extreme temperatures, desiccation or salinity. They are faced with a diurnal cycle with variable length based on their location, which exposes them to extreme salinity conditions (i.e., water withdrawal and high evaporation). Cyanobacteria in the photic zone of a mat ecosystem supply the other microorganism with the required organic material to produce energy and grow. Subsequently, this will reproduce the nutrients needed by the phototrophs through elemental re-mineralization. In this work, we investigated the effect of water salinity that covers the microbial mat ecosystem of Umm Alhool sabkha, Qatar, regarding the most important processes within microbial mats: photosynthesis and sulfate reduction (SR). Our results showed that both photosynthetic and sulfate reduction rates decreased with increasing the salinity. The microbial community structure, assessed by 454 pyro-sequencing, revealed that the cyanobacterial community structure changed in response to the change in salinity. This was not the case for the sulfate reducer community structure, which stayed as it is in the mats incubated at different salinities. Therefore, we speculate that salinity affects the photosynthetic community structure, and consequently affects the photosynthetic activity of the whole ecosystem. However, sulfate reduction rates decreased due to less organic material supply from the upper layers and not due to change in microbial community structure of SR. Other factors such as the activity of the enzymes could also have an effect on SRR, but it was not investigated in this study.

  6. System evaluation and microbial analysis of a sulfur cycle-based wastewater treatment process for Co-treatment of simple wet flue gas desulfurization wastes with freshwater sewage.

    Science.gov (United States)

    Qian, Jin; Liu, Rulong; Wei, Li; Lu, Hui; Chen, Guang-Hao

    2015-09-01

    A sulfur cycle-based wastewater treatment process, namely the Sulfate reduction, Autotrophic denitrification and Nitrification Integrated process (SANI(®) process) has been recently developed for organics and nitrogen removal with 90% sludge minimization and 35% energy reduction in the biological treatment of saline sewage from seawater toilet flushing practice in Hong Kong. In this study, sulfate- and sulfite-rich wastes from simple wet flue gas desulfurization (WFGD) were considered as a potential low-cost sulfur source to achieve beneficial co-treatment with non-saline (freshwater) sewage in continental areas, through a Mixed Denitrification (MD)-SANI process trialed with synthetic mixture of simple WFGD wastes and freshwater sewage. The system showed 80% COD removal efficiency (specific COD removal rate of 0.26 kg COD/kg VSS/d) at an optimal pH of 7.5 and complete denitrification through MD (specific nitrogen removal rate of 0.33 kg N/kg VSS/d). Among the electron donors in MD, organics and thiosulfate could induce a much higher denitrifying activity than sulfide in terms of both NO3(-) reduction and NO2(-) reduction, suggesting a much higher nitrogen removal rate in organics-, thiosulfate- and sulfide-based MD in MD-SANI compared to sulfide alone-based autotrophic denitrification in conventional SANI(®). Diverse sulfate/sulfite-reducing bacteria (SRB) genera dominated in the bacterial community of sulfate/sulfite-reducing up-flow sludge bed (SRUSB) sludge without methane producing bacteria detected. Desulfomicrobium-like species possibly for sulfite reduction and Desulfobulbus-like species possibly for sulfate reduction are the two dominant groups with respective abundance of 24.03 and 14.91% in the SRB genera. Diverse denitrifying genera were identified in the bacterial community of anoxic up-flow sludge bed (AnUSB) sludge and the Thauera- and Thiobacillus-like species were the major taxa. These results well explained the successful operation of the lab

  7. A hybrid life cycle and multi-criteria decision analysis approach for identifying sustainable development strategies of Beijing's taxi fleet

    International Nuclear Information System (INIS)

    Cai, Yanpeng; Applegate, Scott; Yue, Wencong; Cai, Jianying; Wang, Xuan; Liu, Gengyuan; Li, Chunhui

    2017-01-01

    To identify and evaluate sustainable strategies of taxi fleet in Beijing in terms of economic, policy, and environmental implications, a hybrid approach was developed through incorporating multi-criteria decision analysis (MCDA) methods within a general life-cycle analysis (LCA) framework. The approach can (a) help comprehensive evaluate environmental impacts of multiple types of vehicles, (b) facilitate analysis of environmental, economic and policy features of such vehicles, and (c) identify desirable taxi fleet development strategies for the city. The developed approach represented an improvement of the decision-making capability for taxi implementation based on multiple available technologies and their performance that can be specifically tailored to Beijing. The results demonstrated that the proposed approach could comprehensively reflect multiple implications of strategies for the taxi fleet in Beijing to reduce air pollution in the city. The results also indicated that the electric vehicle powered with the year 2020 electricity projections would be the ideal solution, outranking the other alternatives. The conventional vehicle ranked the lowest among the alternatives. The plug-in hybrid vehicle powered by 2020 electricity projects ranked the third, followed by the plug-in hybrid vehicle ranking the fourth, and the hybrid vehicle ranking the fifth. - Highlights: • An hybrid approach was proposed for evaluating sustainable strategies of Beijing's taxi fleet. • This approach was based on the combination of multi-criteria decision analysis methods and life-cycle assessment. • Environmental, economic and policy performances of multiple strategies were compared. • Detailed responses of taxi drivers and local residents were interviewed. • The electric vehicle would be the ideal solution for Beijing Taxi fleet.

  8. An optimized Fuzzy Logic Controller by Water Cycle Algorithm for power management of Stand-alone Hybrid Green Power generation

    International Nuclear Information System (INIS)

    Sarvi, Mohammad; Avanaki, Isa Nasiri

    2015-01-01

    Highlights: • A new method to improve the performance of renewable power management is proposed. • The proposed method is based on Fuzzy Logic optimized by the Water Cycle Algorithm. • The proposed method characteristics are compared with two other methods. • The comparisons confirm that the proposed method is robust and effectiveness one. - Abstract: This paper aims to improve the power management system of a Stand-alone Hybrid Green Power generation based on the Fuzzy Logic Controller optimized by the Water Cycle Algorithm. The proposed Stand-alone Hybrid Green Power consists of wind energy conversion and photovoltaic systems as primary power sources and a battery, fuel cell, and Electrolyzer as energy storage systems. Hydrogen is produced from surplus power generated by the wind energy conversion and photovoltaic systems of Stand-alone Hybrid Green Power and stored in the hydrogen storage tank for fuel cell later using when the power generated by primary sources is lower than load demand. The proposed optimized Fuzzy Logic Controller based power management system determines the power that is generated by fuel cell or use by Electrolyzer. In a hybrid system, operation and maintenance cost and reliability of the system are the important issues that should be considered in studies. In this regard, Water Cycle Algorithm is used to optimize membership functions in order to simultaneously minimize the Loss of Power Supply Probability and operation and maintenance. The results are compared with the particle swarm optimization and the un-optimized Fuzzy Logic Controller power management system to prove that the proposed method is robust and effective. Reduction in Loss of Power Supply Probability and operation and maintenance, are the most advantages of the proposed method. Moreover the level of the State of Charge of the battery in the proposed method is higher than other mentioned methods which leads to increase battery lifetime.

  9. A Hybrid Algorithm for Solving the Economic Lot and Delivery Scheduling Problem in the Common Cycle Case

    DEFF Research Database (Denmark)

    Ju, Suquan; Clausen, Jens

    2004-01-01

    The ELDSP problem is a combined lot sizing and sequencing problem. A supplier produces and delivers components of different component types to a consumer in batches. The task is to determine the cycle time, i.e. that time between deliveries, which minimizes the total cost per time unit. This incl......The ELDSP problem is a combined lot sizing and sequencing problem. A supplier produces and delivers components of different component types to a consumer in batches. The task is to determine the cycle time, i.e. that time between deliveries, which minimizes the total cost per time unit....... This includes the determination of the production sequence of the component types within each cycle. We investigate the computational behavior of two published algorithms, a heuristic and an optimal algorithm. With large number of component types, the optimal algorithm has long running times. We devise a hybrid...

  10. Regulation of the HscA ATPase reaction cycle by the co-chaperone HscB and the iron-sulfur cluster assembly protein IscU.

    Science.gov (United States)

    Silberg, Jonathan J; Tapley, Tim L; Hoff, Kevin G; Vickery, Larry E

    2004-12-24

    The ATPase activity of HscA, a specialized hsp70 molecular chaperone from Escherichia coli, is regulated by the iron-sulfur cluster assembly protein IscU and the J-type co-chaperone HscB. IscU behaves as a substrate for HscA, and HscB enhances the binding of IscU to HscA. To better understand the mechanism by which HscB and IscU regulate HscA, we examined binding of HscB to the different conformational states of HscA and the effects of HscB and IscU on the kinetics of the individual steps of the HscA ATPase reaction cycle. Affinity sensor studies revealed that whereas IscU binds both ADP (R-state) and ATP (T-state) HscA complexes, HscB interacts only with an ATP-bound state. Studies of ATPase activity under single-turnover and rapid mixing conditions showed that both IscU and HscB interact with the low peptide affinity T-state of HscA (HscA++.ATP) and that both modestly accelerate (3-10-fold) the rate-determining steps in the HscA reaction cycle, k(hyd) and k(T-->R). When present together, IscU and HscB synergistically stimulate both k(hyd) (approximately = 500-fold) and k(T-->R) (approximately = 60-fold), leading to enhanced formation of the HscA.ADP-IscU complex (substrate capture). Following ADP/ATP exchange, IscU also stimulates k(R-->T) (approximately = 50-fold) and thereby accelerates the rate at which the low peptide affinity HscA++.ATP T-state is regenerated. Because HscA nucleotide exchange is fast, the overall rate of the chaperone cycle in vivo will be determined by the availability of the IscU-HscB substrate-co-chaperone complex.

  11. 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...

  12. Study of DD versus DT fusion fuel cycles for different fusion-fission hybrid energy systems

    International Nuclear Information System (INIS)

    Gohar, Y.; Baker, C.C.

    1981-01-01

    A study was performed to investigate the characteristics of an energy system to produce fissile fuel for fission reactors. DD and DT fusion reactors were examined in this study with either a thorium or uranium blanket for each fusion reactor. Various fuel cycles were examined for light-water reactors including the denatured fuel cycles (which may offer proliferation resistance compared to other fuel cycles); these fuel cycles include a uranium fuel cycle with 239 Pu makeup, a thorium fuel cycle with 239 Pu makeup, a denatured uranium fuel cycle with 233 U makeup, and a denatured thorium fuel cycle with 233 U makeup. Four different blankets were considered for this study. The first two blankets have a tritium breeding capability for DT reactors. Lithium oxide (Li 2 O) was used for tritium breeding due to its high lithium density and high temperature capability; however, the use of Li 2 O may result in higher tritium inventories compared to other solid breeders

  13. Hybridization Associated with Cycles of Ecological Succession in a Passerine Bird.

    Science.gov (United States)

    Duckworth, Renée A; Semenov, Georgy A

    2017-10-01

    Identifying the diversity of contexts that can lead to hybridization is important for understanding its prevalence and dynamics in natural populations. Despite the potential of ecological succession to dramatically alter species co-occurrence and abundances, it is unknown whether it directly promotes hybridization and, if so, has long-lasting consequences. Here, we summarize 30 years of survey data across 10 populations to show that in western and mountain bluebirds, heterospecific pairing occurs during repeatable and transient colonization events at the early stages of species turnover. Despite mixed pairing occurring only during early succession, genetic data showed presence of hybrids at both early and late successional stages. Moreover, hybrids showed novel patterns of variation in morphology and behavior, emphasizing that even ephemeral contexts for hybridization can have important evolutionary consequences. Our results suggest that because ecological succession often brings together closely related competitors in disparate numbers but lasts for only a brief period of time, it may be a widespread but underappreciated context for hybridization.

  14. 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

  15. 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. ...

  16. New high expansion ratio gasoline engine for the TOYOTA hybrid system. Improving engine efficiency with high expansion ratio cycle; Hybrid system yo kobochohi gasoline engine. Kobochohi cycle ni yoru engine no kokoritsuka

    Energy Technology Data Exchange (ETDEWEB)

    Hirose, K; Takaoka, T; Ueda, T; Kobayashi, Y [Toyota Motor Corp., Aichi (Japan)

    1997-10-01

    50% reduction of CO2 and fuel consumption have been achieved with the newly developed gasoline engine for the Toyota Hybrid System. This is achieved due to the combination of electric motors and the internal combustion engine which is optimized in the size, swept volume and heat cycle. By delaying the intake valve close timing a high expansion ratio (13.5:1) cycle has been realized. Electricmotor assist enable to cut the maximum engine speed, and friction loss. A best fuel consumption figure better than 230 g/kWh has been achieved. Elimination of lightload firing, motor assisted quick start and improvement of catalyst warm up makes to achieve the clean emission level such as 1/10 of Japanese `78 regulation limit. 10 refs., 16 figs., 1 tab.

  17. 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.

  18. Energy storage technologies and hybrid architectures for specific diesel-driven rail duty cycles: Design and system integration aspects

    International Nuclear Information System (INIS)

    Meinert, M.; Prenleloup, P.; Schmid, S.; Palacin, R.

    2015-01-01

    Highlights: • We assessed integration of energy storage systems into hybrid system architectures. • We considered mechanical and electrical energy storage systems. • Potential of different combinations has been analyzed by standardized duty cycles. • Most promising are diesel-driven suburban, regional and shunting operations. • Double-layer capacitors and Lithium-ion batteries have the highest potential. - Abstract: The use of diesel-driven traction is an intrinsic part of the functioning of railway systems and it is expected to continue being so for the foreseeable future. The recent introduction of more restrictive greenhouse gas emission levels and other legislation aiming at the improvement of the environmental performance of railway systems has led to the need of exploring alternatives for cleaner diesel rolling stock. This paper focuses on assessing energy storage systems and the design of hybrid system architectures to determine their potential use in specific diesel-driven rail duty cycles. Hydrostatic accumulators, flywheels, Lithium-ion batteries and double-layer capacitors have been assessed and used to design hybrid system architectures. The potential of the different technology combinations has been analyzed using standardized duty cycles enhanced with gradient profiles related to suburban, regional and shunting operations. The results show that double-layer capacitors and Lithium-ion batteries have the highest potential to be successfully integrated into the system architecture of diesel-driven rail vehicles. Furthermore, the results also suggest that combining these two energy storage technologies into a single hybridisation package is a highly promising design that draws on their strengthens without any significant drawbacks.

  19. Electrifying Australian transport: Hybrid life cycle analysis of a transition to electric light-duty vehicles and renewable electricity

    International Nuclear Information System (INIS)

    Wolfram, Paul; Wiedmann, Thomas

    2017-01-01

    Highlights: •This research assesses life-cycle carbon impacts of different powertrains. •We illustrate a transition to low-carbon vehicles in a hybrid IO-LCA model. •Different electricity and transport scenarios are integrated in the model. •With Australia’s current grid-mix, electric vehicles offer no mitigation potential. •Using renewable energy, electric vehicle carbon footprints can be cut by 66%. -- Abstract: Recent life cycle assessments confirmed the greenhouse gas emission reduction potential of renewable electricity and electric vehicle technologies. However, each technology is usually assessed separately and not within a consistent macro-economic, multi-sectoral framework. Here we present a multi-regional input-output based hybrid approach with integrated scenarios to facilitate the carbon footprint assessment of all direct and indirect effects of a transition to low-emission transportation and electricity generation technologies in Australia. The work takes into account on-road energy consumption values that are more realistic than official drive-cycle energy consumption figures used in previous work. Accounting for these factors as well as for Australia’s grid electricity, which heavily relies on coal power, electric vehicles are found to have a higher carbon footprint than conventional vehicles, whereas hybrid electric vehicles have the lowest. This means that – from a carbon footprint perspective – powertrain electrification is beneficial only to a certain degree at the current stage. This situation can be changed by increasing shares of renewable electricity in the grid. In our best-case scenario, where renewable energy accounts for 96% of the electricity mix in 2050, electric vehicle carbon footprints can be cut by 66% by 2050 relative to 2009. In the business-as-usual scenario (36% renewable electricity share by 2050), electric vehicles can reach a 56% reduction if fossil fuel power plants significantly increase their efficiencies

  20. Life cycle cost of a hybrid forward osmosis – low pressure reverse osmosis system for seawater desalination and wastewater recovery

    KAUST Repository

    Valladares Linares, Rodrigo

    2015-10-19

    In recent years, forward osmosis (FO) hybrid membrane systems have been investigated as an alternative to conventional high-pressure membrane processes (i.e. reverse osmosis (RO)) for seawater desalination and wastewater treatment and recovery. Nevertheless, their economic advantage in comparison to conventional processes for seawater desalination and municipal wastewater treatment has not been clearly addressed. This work presents a detailed economic analysis on capital and operational expenses (CAPEX and OPEX) for: i) a hybrid forward osmosis – low-pressure reverse osmosis (FO-LPRO) process, ii) a conventional seawater reverse osmosis (SWRO) desalination process, and iii) a membrane bioreactor – reverse osmosis – advanced oxidation process (MBR-RO-AOP) for wastewater treatment and reuse. The most important variables affecting economic feasibility are obtained through a sensitivity analysis of a hybrid FO-LPRO system. The main parameters taken into account for the life cycle costs are the water quality characteristics (similar feed water and similar water produced), production capacity of 100,000 m3 d−1 of potable water, energy consumption, materials, maintenance, operation, RO and FO module costs, and chemicals. Compared to SWRO, the FO-LPRO systems have a 21% higher CAPEX and a 56% lower OPEX due to savings in energy consumption and fouling control. In terms of the total water cost per cubic meter of water produced, the hybrid FO-LPRO desalination system has a 16% cost reduction compared to the benchmark for desalination, mainly SWRO. Compared to the MBR-RO-AOP, the FO-LPRO systems have a 7% lower CAPEX and 9% higher OPEX, resulting in no significant cost reduction per m3 produced by FO-LPRO. Hybrid FO-LPRO membrane systems are shown to have an economic advantage compared to current available technology for desalination, and comparable costs with a wastewater treatment and recovery system. Based on development on FO membrane modules, packing density, and

  1. Optimal design of solid oxide fuel cell, ammonia-water single effect absorption cycle and Rankine steam cycle hybrid system

    Science.gov (United States)

    Mehrpooya, Mehdi; Dehghani, Hossein; Ali Moosavian, S. M.

    2016-02-01

    A combined system containing solid oxide fuel cell-gas turbine power plant, Rankine steam cycle and ammonia-water absorption refrigeration system is introduced and analyzed. In this process, power, heat and cooling are produced. Energy and exergy analyses along with the economic factors are used to distinguish optimum operating point of the system. The developed electrochemical model of the fuel cell is validated with experimental results. Thermodynamic package and main parameters of the absorption refrigeration system are validated. The power output of the system is 500 kW. An optimization problem is defined in order to finding the optimal operating point. Decision variables are current density, temperature of the exhaust gases from the boiler, steam turbine pressure (high and medium), generator temperature and consumed cooling water. Results indicate that electrical efficiency of the combined system is 62.4% (LHV). Produced refrigeration (at -10 °C) and heat recovery are 101 kW and 22.1 kW respectively. Investment cost for the combined system (without absorption cycle) is about 2917 kW-1.

  2. Study on emission characteristics of hybrid bus under driving cycles in typical Chinese city

    Science.gov (United States)

    Xie, Yongdong; Xu, Guangju

    2017-09-01

    In this study, hybrid city bus was taken as the research object, through the vehicle drum test, the vehicle emissions of hybrid bus, the transient emissions of gas pollutants, as well as the particle size and number distribution were surveyed. The results of the studies are listed as follows: First, compared to traditional fuel bus, hybrid bus could reduce about 44% of the NOx emissions, 33% of the total hydrocarbon emissions, and 51% of the particles emissions. Furthermore, the distribution of particles number concentration of test vehicle became high in middle and low in both sides. More specifically, the particle number concentration was mainly concentrated in the range from 0.021 to 0.755μm, the maximum was 0.2μm, and particle size of particulate matter (PM) less than 1.2μm accounted for 95% of the total number concentration. Particulate mass concentration was increased with increment of particle size, and the maximum of particulate mass (PM) concentration was 6.2μm. On average, whether traditional fuel bus or hybrid bus, the particle size of particulate matter(PM) less than 2.5μm accounted for more than 98% in the particles emission. It is found that the particles are more likely to deposit to the lung, respiratory bronchioles and alveoli, causing respiratory and lung diseases. Therefore, how to control the PM emissions of hybrid bus is the key factor of the study.

  3. Exploring the Influence of Attitudes to Walking and Cycling on Commute Mode Choice Using a Hybrid Choice Model

    Directory of Open Access Journals (Sweden)

    Chuan Ding

    2017-01-01

    Full Text Available Transport-related problems, such as automobile dependence, traffic congestion, and greenhouse emissions, lead to a great burden on the environment. In developing countries like China, in order to improve the air quality, promoting sustainable travel modes to reduce the automobile usage is gradually recognized as an emerging national concern. Though there are many studies related to the physically active modes (e.g., walking and cycling, the research on the influence of attitudes to active modes on travel behavior is limited, especially in China. To fill up this gap, this paper focuses on examining the impact of attitudes to walking and cycling on commute mode choice. Using the survey data collected in China cities, an integrated discrete choice model and the structural equation model are proposed. By applying the hybrid choice model, not only the role of the latent attitude played in travel mode choice, but also the indirect effects of social factors on travel mode choice are obtained. The comparison indicates that the hybrid choice model outperforms the traditional model. This study is expected to provide a better understanding for urban planners on the influential factors of green travel modes.

  4. 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

  5. Comparison of Plug-In Hybrid Electric Vehicle Battery Life Across Geographies and Drive-Cycles

    International Nuclear Information System (INIS)

    Smith, K.; Warleywine, M.; Wood, E.; Neubauer, J.; Pesaran, A.

    2012-01-01

    In a laboratory environment, it is cost prohibitive to run automotive battery aging experiments across a wide range of possible ambient environment, drive cycle and charging scenarios. Since worst-case scenarios drive the conservative sizing of electric-drive vehicle batteries, it is useful to understand how and why those scenarios arise and what design or control actions might be taken to mitigate them. In an effort to explore this problem, this paper applies a semi-empirical life model of the graphite/nickel-cobalt-aluminum lithium-ion chemistry to investigate impacts of geographic environments under storage and simplified cycling conditions. The model is then applied to analyze complex cycling conditions, using battery charge/discharge profiles generated from simulations of PHEV10 and PHEV40 vehicles across 782 single-day driving cycles taken from Texas travel survey data.

  6. A synergetic hybridization of adsorption cycle with the multi-effect distillation (MED)

    KAUST Repository

    Thu, K.; Kim, Youngdeuk; Amy, Gary L.; Chun, Wongee; Ng, Kim Choon

    2014-01-01

    Multi-effect distillation (MED) systems are proven and energy efficient thermally-driven desalination systems for handling harsh seawater feed in the Gulf region. The high cycle efficiency is markedly achieved by latent energy re-use with minimal

  7. 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

  8. A Dynamic Control Strategy for Hybrid Electric Vehicles Based on Parameter Optimization for Multiple Driving Cycles and Driving Pattern Recognition

    Directory of Open Access Journals (Sweden)

    Zhenzhen Lei

    2017-01-01

    Full Text Available The driving pattern has an important influence on the parameter optimization of the energy management strategy (EMS for hybrid electric vehicles (HEVs. A new algorithm using simulated annealing particle swarm optimization (SA-PSO is proposed for parameter optimization of both the power system and control strategy of HEVs based on multiple driving cycles in order to realize the minimum fuel consumption without impairing the dynamic performance. Furthermore, taking the unknown of the actual driving cycle into consideration, an optimization method of the dynamic EMS based on driving pattern recognition is proposed in this paper. The simulation verifications for the optimized EMS based on multiple driving cycles and driving pattern recognition are carried out using Matlab/Simulink platform. The results show that compared with the original EMS, the former strategy reduces the fuel consumption by 4.36% and the latter one reduces the fuel consumption by 11.68%. A road test on the prototype vehicle is conducted and the effectiveness of the proposed EMS is validated by the test data.

  9. Zn/V2O5 Aqueous Hybrid-Ion Battery with High Voltage Platform and Long Cycle Life.

    Science.gov (United States)

    Hu, Ping; Yan, Mengyu; Zhu, Ting; Wang, Xuanpeng; Wei, Xiujuan; Li, Jiantao; Zhou, Liang; Li, Zhaohuai; Chen, Lineng; Mai, Liqiang

    2017-12-13

    Aqueous zinc-ion batteries attract increasing attention due to their low cost, high safety, and potential application in stationary energy storage. However, the simultaneous realization of high cycling stability and high energy density remains a major challenge. To tackle the above-mentioned challenge, we develop a novel Zn/V 2 O 5 rechargeable aqueous hybrid-ion battery system by using porous V 2 O 5 as the cathode and metallic zinc as the anode. The V 2 O 5 cathode delivers a high discharge capacity of 238 mAh g -1 at 50 mA g -1 . 80% of the initial discharge capacity can be retained after 2000 cycles at a high current density of 2000 mA g -1 . Meanwhile, the application of a "water-in-salt" electrolyte results in the increase of discharge platform from 0.6 to 1.0 V. This work provides an effective strategy to simultaneously enhance the energy density and cycling stability of aqueous zinc ion-based batteries.

  10. Life cycle cost of a hybrid forward osmosis - low pressure reverse osmosis system for seawater desalination and wastewater recovery.

    Science.gov (United States)

    Valladares Linares, R; Li, Z; Yangali-Quintanilla, V; Ghaffour, N; Amy, G; Leiknes, T; Vrouwenvelder, J S

    2016-01-01

    In recent years, forward osmosis (FO) hybrid membrane systems have been investigated as an alternative to conventional high-pressure membrane processes (i.e. reverse osmosis (RO)) for seawater desalination and wastewater treatment and recovery. Nevertheless, their economic advantage in comparison to conventional processes for seawater desalination and municipal wastewater treatment has not been clearly addressed. This work presents a detailed economic analysis on capital and operational expenses (CAPEX and OPEX) for: i) a hybrid forward osmosis - low-pressure reverse osmosis (FO-LPRO) process, ii) a conventional seawater reverse osmosis (SWRO) desalination process, and iii) a membrane bioreactor - reverse osmosis - advanced oxidation process (MBR-RO-AOP) for wastewater treatment and reuse. The most important variables affecting economic feasibility are obtained through a sensitivity analysis of a hybrid FO-LPRO system. The main parameters taken into account for the life cycle costs are the water quality characteristics (similar feed water and similar water produced), production capacity of 100,000 m(3) d(-1) of potable water, energy consumption, materials, maintenance, operation, RO and FO module costs, and chemicals. Compared to SWRO, the FO-LPRO systems have a 21% higher CAPEX and a 56% lower OPEX due to savings in energy consumption and fouling control. In terms of the total water cost per cubic meter of water produced, the hybrid FO-LPRO desalination system has a 16% cost reduction compared to the benchmark for desalination, mainly SWRO. Compared to the MBR-RO-AOP, the FO-LPRO systems have a 7% lower CAPEX and 9% higher OPEX, resulting in no significant cost reduction per m(3) produced by FO-LPRO. Hybrid FO-LPRO membrane systems are shown to have an economic advantage compared to current available technology for desalination, and comparable costs with a wastewater treatment and recovery system. Based on development on FO membrane modules, packing density, and

  11. Hybrid high solar share gas turbine systems with innovative gas turbine cycles

    OpenAIRE

    Puppe, Michael; Giuliano, Stefano; Buck, Reiner; Krüger, Michael; Lammel, Oliver; Boje, Sven; Saidi, Karim; Gampe, Uwe; Felsmann, Christian; Freimark, Manfred; Langnickel, Ulrich

    2015-01-01

    In this paper results from an ongoing research project (HYGATE) are presented, which is performed to reduce the levelized cost of electricity (LCOE) and to increase the CO2 reduction potential of the solar-hybrid gas turbine plant concept (SHGT). Key improvements are the integration of thermal energy storage and the reduction of the operating temperature of the gas turbine to 950°C. As a result the solar receiver can provide the necessary temperature for solar-only operation of the plant at d...

  12. Analysis of environmental effect of hybrid solar-assisted desalination cycle in Sirdarya Thermal Power Plant, Uzbekistan

    International Nuclear Information System (INIS)

    Alikulov, Khusniddin; Xuan, Tran Dang; Higashi, Osamu; Nakagoshi, Nobukazu; Aminov, Zarif

    2017-01-01

    Highlights: • A hybrid solar-assisted desalination cycle was designed and stimulated. • Maximum of 21,064.00 kW effective solar heat can be achieved. • The use of parabolic-trough collectors in the Multi Effect Distillation is potential. • The cycle can be applied in other regions with high Direct Normal Irradiation. - Abstract: This study was to investigate possible reduction of fossil fuel consumption and carbon dioxide emission in one of energy sectors of Sirdarya Thermal Power Plant (TPP), Uzbekistan. A hybrid solar-assisted desalination cycle has been designed and simulated for partially supplying saturated steam with 200 °C, 8 bar, and 32 t/h parameters to a Multi Effect Distillation (MED) process in the Sirdarya Thermal Power Plant. The outcome of the parental design model stated that maximum, 21,064.00 kW effective solar heat can be achieved, which is equivalent to 31.76 t/h of saturated steam with 200 °C and 8 bar parameters. Total saved fossil fuel in each month proved that it is possible to reduce fossil fuel (heavy oil and natural gas) consumption with 59.64, 95.24, 389.96, and 298.26 tons during available Direct Normal Irradiation (DNI) by using parabolic-trough collectors. Moreover, the above-mentioned fossil fuel savings accounted for CO_2 reduction with amounts of 182.50, 255.46, 1045.87 & 799.96 tons per each consistent month. Findings proved that integration of parabolic-trough collectors into the MED process is feasible in terms of high DNI availability and demand for retrofitting old existing heat-consuming facilities in Sirdarya Thermal Power Plant. Besides, the cycle also can be applied in other regions of Uzbekistan with high DNI for generating solar heat. Therefore, conducted study is eligible to be applied on the research site by taking into account of sufficient meteorological data and required steam parameters.

  13. Hybrid gas turbine–organic Rankine cycle for seawater desalination by reverse osmosis in a hydrocarbon production facility

    International Nuclear Information System (INIS)

    Eveloy, Valérie; Rodgers, Peter; Qiu, Linyue

    2015-01-01

    Highlights: • Seawater reverse osmosis driven by hybrid gas turbine–organic Rankine power cycle. • High ambient air and seawater temperatures, and high seawater salinity. • Energy–exergy analysis of power and desalination systems for six organic fluids. • Economic viability of waste heat recovery in subsidized utility pricing context. - Abstract: Despite water scarcity, the use of industrial waste heat for seawater desalination has been limited in the Middle East to date. This study evaluates the technical and economic feasibility of integrating on-site gas turbine power generation and reverse osmosis equipment for the production of both electricity and fresh water in a coastal hydrocarbon production facility. Gas turbine exhaust gas waste heat is recovered using an intermediate heat transfer fluid and fed to an organic Rankine cycle evaporator, to generate mechanical power to drive the reverse osmosis high pressure pump. Six candidate organic working fluids are evaluated, namely toluene, benzene, cyclohexane, cyclopentane, n-pentane and R245fa. Thermodynamic and desalination performance are assessed in the harsh climatic and salinity conditions of the Arabian Gulf. The performance metrics considered incorporate electric power and permeate production, thermal and exergy efficiency, specific energy consumption, system size, and permeate quality. Using toluene in the bottoming power cycle, a gain in power generation efficiency of approximately 12% is achieved relative to the existing gas turbine cycle, with an annual average of 2260 m"3/h of fresh water produced. Depending upon the projected evolution of local water prices, the investment becomes profitable after two to four years, with an end-of-life net present value of 220–380 million USD, and internal rate of return of 26–48%.

  14. A hybrid life cycle assessment of the vehicle-to-grid application in light duty commercial fleet

    International Nuclear Information System (INIS)

    Zhao, Yang; Tatari, Omer

    2015-01-01

    The vehicle-to-grid system is an approach utilizing the idle battery capacity of electric vehicles while they are parked to provide supplementary energy to the power grid. As electrification continues in light duty vehicle fleets, the application of vehicle-to-grid systems for commercial delivery truck fleets can provide extra revenue for fleet owners, and also has significant potential for reducing greenhouse gas emissions from the electricity generation sector. In this study, an economic input–output based hybrid life cycle assessment is conducted to analyze the potential greenhouse gas emissions emission savings from the use of the vehicle-to-grid system, as well as the possible emission impacts caused by battery degradation. A Monte Carlo simulation was performed to address the uncertainties that lie in the electricity exchange amount of the vehicle-to-grid service as well as the battery life of the electric vehicles. The results of this study showed that extended range electric vehicles and battery electric vehicles are both viable regulation service providers for saving greenhouse gas emissions from electricity generation if the battery wear-out from regulation services is assumed to be minimal, but the vehicle-to-grid system becomes less attractive at higher battery degradation levels. - Highlights: • The commercial delivery trucks are studied as vehicle-to-grid service providers. • Hybrid life cycle assessment is conducted to evaluate emission mitigation. • Battery degradation level and corresponding emissions and cost are evaluated. • Vehicle-to-grid service is shown to have significant emission saving effect.

  15. Anaerobic sulfide-oxidation in marine colorless sulfur-oxidizing bacteria

    Digital Repository Service at National Institute of Oceanography (India)

    LokaBharathi, P.A.; Nair, S.; Chandramohan, D.

    Colorless sulfur-oxidizing bacteria are ubiquitous in Indian waters and have the ability to oxidize sulfide under anaerobic conditions. These bacteria can not only mediate the sulfur cycle oxidatively but also the nitrogen cycle reductively without...

  16. Effects of Hybrid Cycle and Handcycle Exercise on Cardiovascular Disease Risk Factors in People with Spinal Cord Injury: a Randomized Controlled Trial

    NARCIS (Netherlands)

    Bakkum, A.J.T.; Paulson, T.A.W.; Bishop, N.C.; Goosey-Tolfrey, V.L.; Stolwijk-Swuste, J.M.; van Kuppevelt, D.J.; de Groot, S.; Janssen, T.W.J.

    2015-01-01

    Objective: To examine the effects of a 16-week exercise programme, using either a hybrid cycle or a handcycle, on cardiovascular disease risk factors in people with spinal cord injury. Participants: Nineteen individuals with spinal cord injury ≥ 8 years. Design: Multicentre randomized controlled

  17. Effects of Hybrid Cycle and Handcycle Exercise on Cardiovascular Disease Risk Factors in People with Spinal Cord Injury : A Randomized Controlled Trial

    NARCIS (Netherlands)

    Bakkum, Arjan J. T.; Paulson, Thomas A. W.; Bishop, Nicolette C.; Goosey-Tolfrey, Victoria L.; Stolwijk-Swuste, Janneke M.; van Kuppevelt, Dirk J.; de Groot, Sonja; Janssen, Thomas W. J.

    Objective: To examine the effects of a 16-week exercise programme, using either a hybrid cycle or a handcycle, on cardiovascular disease risk factors in people with spinal cord injury. Participants: Nineteen individuals with spinal cord injury >= 8 years. Design: Multicentre randomized controlled

  18. 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

  19. Life cycle assessment of hybrid vehicles recycling: Comparison of three business lines of dismantling.

    Science.gov (United States)

    Belboom, Sandra; Lewis, Grégory; Bareel, Pierre-François; Léonard, Angélique

    2016-04-01

    This paper undertakes an environmental evaluation of hybrid vehicles recycling, using industrial data from Comet Traitement SA in Belgium. Three business lines have been modelled and analysed. The first one is relative to the business as usual with a dismantling to recover batteries and engines followed by shredding and post shredding treatments. The second one considers, in addition, the removal of electronic control units (ECU) before shredding followed by same steps than in the first line and the last one is relative to the additional removal of big plastic parts before shredding and business as usual post shredding treatments. Results show non-significant environmental benefits when ECU or large parts of plastics are recovered before shredding. Improvements in terms of environmental benefits are lower than the uncertainty of the results. Indeed, the performing usual process for end-of-life vehicles (ELV) treatment reaches 97% of the ELV which is valorised in terms of metal and energy recoveries. Post shredding treatment units include metals, plastics and energy recovery of residues. Comet business as usual route for ELV valorisation is in accordance with the requirements of the European directive and recommendations for further improvement with dismantling of other parts (ECU or plastics) before shredding are non-relevant in this case. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Burn-up calculation of fusion-fission hybrid reactor using thorium cycle

    International Nuclear Information System (INIS)

    Shido, S.; Matsunaka, M.; Kondo, K.; Murata, I.; Yamamoto, Y.

    2006-01-01

    A burn-up calculation system has been developed to estimate performance of blanket in a fusion-fission hybrid reactor which is a fusion reactor with a blanket region containing nuclear fuel. In this system, neutron flux is calculated by MCNP4B and then burn-up calculation is performed by ORIGEN2. The cross-section library for ORIGEN2 is made from the calculated neutron flux and evaluated nuclear data. The 3-dimensional ITER model was used as a base fusion reactor. The nuclear fuel (reprocessed plutonium as the fission materials mixed with thorium as the fertile materials), transmutation materials (minor actinides and long-lived fission products) and tritium breeder were loaded into the blanket. Performances of gas-cooled and water-cooled blankets were compared with each other. As a result, the proposed reactor can meet the requirement for TBP and power density. As far as nuclear waste incineration is concerned, the gas-cooled blanket has advantages. On the other hand, the water cooled-blanket is suited to energy production. (author)

  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. 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.

  3. Electric and Hybrid Vehicle System Research and Development Project: Hybrid Vehicle Potential Assessment. Volume VI. Cost analysis

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, K.S.

    1979-09-30

    The purpose of the cost analysis is to determine the economic feasibility of a variety of hybrid vehicles with respect to conventional vehicles specifically designed for the same duty cycle defined by the mission analysis. Several different hybrid configurations including parallel, parallel-flywheel, and series vehicles were evaluated. The ramifications of incorporating examples of advanced batteries, these being the advanced lead-acid, nickel-zinc, and sodium sulfur were also investigated. Vehicles were specifically designed with these batteries and for the driving cycles specified by the mission. Simulated operation on the missions yielded the energy consumption (petroleum and/or electricity) over the driving cycles. It was concluded that: in the event that gasoline prices reach $2.50 to $3.00/gal, hybrid vehicles in many applications will become economically competitive with conventional vehicles without subsidization; in some commercial applications hybrid vehicles could be economically competitive, when the gasoline price ranges from $1.20 to $1.50/gal. The cost per kWh per cycle of the advanced batteries is much more important economically than the specific energy; the series hybrid vehicles were found to be more expensive in comparison to the parallel or parallel-flywheel hybrids when designed as passenger vehicles; and hybrid vehicles designed for private use could become economically competitive and displace up to 50% of the fuel normally used on that mission if subsidies of $500 to $2000 were supplied to the owner/operator. (LCL)

  4. Economic assessment and energy model scenarios of municipal solid waste incineration and gas turbine hybrid dual-fueled cycles in Thailand

    International Nuclear Information System (INIS)

    Udomsri, Seksan; Martin, Andrew R.; Fransson, Torsten H.

    2010-01-01

    Finding environmentally benign methods related to sound municipal solid waste (MSW) management is of highest priority in Southeast Asia. It is very important to study new approaches which can reduce waste generation and simultaneously enhance energy recovery. One concrete example of particular significance is the concept of hybrid dual-fuel power plants featuring MSW and another high-quality fuel like natural gas. The hybrid dual-fuel cycles provide significantly higher electrical efficiencies than a composite of separate single-fuel power plant (standalone gas turbine combined cycle and MSW incineration). Although hybrid versions are of great importance for energy conversion from MSW, an economic assessment of these systems must be addressed for a realistic appraisal of these technologies. This paper aims to further examine an economic assessment and energy model analysis of different conversion technologies. Energy models are developed to further refine the expected potential of MSW incineration with regards to energy recovery and environmental issues. Results show that MSW incineration can play role for greenhouse gas reduction, energy recovery and waste management. In Bangkok, the electric power production via conventional incineration and hybrid power plants can cover 2.5% and 8% of total electricity consumption, respectively. The hybrid power plants have a relative short payback period (5 years) and can further reduce the CO 2 levels by 3% in comparison with current thermal power plants.

  5. Technology Development of an Advanced Small-scale Microchannel-type Process Heat Exchanger (PHE) for Hydrogen Production in Iodine-sulfur Cycle

    Energy Technology Data Exchange (ETDEWEB)

    Sah, Injin; Kim, Chan Soo; Kim, Yong Wan; Park, Jae-Won; Kim, Eung-Seon; Kim, Min-Hwan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    In this study, ongoing manufacturing processes of the components employed in an advanced small-scale microchannel-type PHE are presented. The components, such as mechanically machined microchannels and a diffusion-bonded stack are introduced. Also, preliminary studies on surface treatment techniques for improving corrosion resistance from the corrosive sulfuric environment will be covered. Ongoing manufacturing process for an advanced small-size microchannel-type PHE in KAERI is presented. Through the preliminary studies for optimizing diffusion bonding condition of Hastelloy-X, a diffusion-bonded stack, consisting of primary and secondary side layer by layer, is scheduled to be fabricated in a few months. Also, surface treatment for enhancing the corrosion resistance from the sulfuric acid environment is in progress for the plates with microchannels. A massive production of hydrogen with electricity generation is expected in a Process Heat Exchanger (PHE) in a Very High Temperature gas-cooled Reactor (VHTR) system. For the application of hydrogen production, a small-scale gas loop for feasibility testing of a laboratory-scale has constructed and operated in Korea Atomic Energy Research Institute (KAERI) as a precursor to an experimental- and a pilot-scale gas loops.

  6. 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...

  7. Turboelectric Distributed Propulsion Engine Cycle Analysis for Hybrid-Wing-Body Aircraft

    Science.gov (United States)

    Felder, James L.; Kim, Hyun Dae; Brown, Gerald V.

    2009-01-01

    possibilities. The Boeing N2 hybrid-wing-body (HWB) is used as a baseline aircraft for this study. The two pylon mounted conventional turbofans are replaced by two wing-tip mounted turboshaft engines, each driving a superconducting generator. Both generators feed a common electrical bus which distributes power to an array of superconducting motor-driven fans in a continuous nacelle centered along the trailing edge of the upper surface of the wing-body. A key finding was that traditional inlet performance methodology has to be modified when most of the air entering the inlet is boundary layer air. A very thorough and detailed propulsion/airframe integration (PAI) analysis is required at the very beginning of the design process since embedded engine inlet performance must be based on conditions at the inlet lip rather than freestream conditions. Examination of a range of fan pressure ratios yielded a minimum Thrust-specific-fuel-consumption (TSFC) at the aerodynamic design point of the vehicle (31,000 ft /Mach 0.8) between 1.3 and 1.35 FPR. We deduced that this was due to the higher pressure losses prior to the fan inlet as well as higher losses in the 2-D inlets and nozzles. This FPR is likely to be higher than the FPR that yields a minimum TSFC in a pylon mounted engine. 1

  8. Dynamic Modeling and Plantwide Control of a Hybrid Power and Chemical Plant: An Integrated Gasification Combined Cycle Coupled with a Methanol Plant

    Science.gov (United States)

    Robinson, Patrick J.

    Gasification has been used in industry on a relatively limited scale for many years, but it is emerging as the premier unit operation in the energy and chemical industries. The switch from expensive and insecure petroleum to solid hydrocarbon sources (coal and biomass) is occurring due to the vast amount of domestic solid resources, national security and global warming issues. Gasification (or partial oxidation) is a vital component of "clean coal" technology. Sulfur and nitrogen emissions can be reduced, overall energy efficiency is increased and carbon dioxide recovery and sequestration are facilitated. Gasification units in an electric power generation plant produce a fuel gas for driving combustion turbines. Gasification units in a chemical plant generate synthesis gas, which can be used to produce a wide spectrum of chemical products. Future plants are predicted to be hybrid power/chemical plants with gasification as the key unit operation. The coupling of an Integrated Gasification Combined Cycle (IGCC) with a methanol plant can handle swings in power demand by diverting hydrogen gas from a combustion turbine and synthesis gas from the gasifier to a methanol plant for the production of an easily-stored, hydrogen-consuming liquid product. An additional control degree of freedom is provided with this hybrid plant, fundamentally improving the controllability of the process. The idea is to base-load the gasifier and use the more responsive gas-phase units to handle disturbances. During the summer days, power demand can fluctuate up to 50% over a 12-hour period. The winter provides a different problem where spikes of power demand can go up 15% within the hour. The following dissertation develops a hybrid IGCC / methanol plant model, validates the steady-state results with a National Energy Technical Laboratory study, and tests a proposed control structure to handle these significant disturbances. All modeling was performed in the widely used chemical process

  9. Sulfur and Nitrogen co-doped graphene quantum dot decorated ZnO nanorod/polymer hybrid flexible device for photosensing applications

    Energy Technology Data Exchange (ETDEWEB)

    Hmar, Jehova Jire L.; Majumder, Tanmoy; Dhar, Saurab; Mondal, Suvra Prakash, E-mail: suvraphy@gmail.com

    2016-08-01

    S and N co-doped graphene quantum dots (S,N-GQDs) have been synthesized by a hydrothermal process. S,N-GQDs are made up of 1–5 monolayer of graphene with average diameter 13.3 nm. The absorption peaks at 336 and 621 nm, are attributed to n → Π{sup ⁎} transitions of electrons in C=O and S=O bonds, respectively. S,N-GQDs are highly luminescent and showed excitation dependent emission behaviors. Hybrid photosensing device has been fabricated with S,N-GQD sensitized ZnO nanorods and a conjugated polymer poly(3-hexylthiophene) (P3HT). S,N-GQD decorated ZnO nanorod demonstrated higher photoresponse compared to pristine ZnO nanorod based device. S,N-GQD/ZnO nanorod hybrid device showed superior incident photon to electron conversion efficiency (IPCE), photoresponsivity and detectivity compared to the control samples. The flexibility study of the samples has been monitored by measuring current-voltage characteristics at different bending angles. - Highlights: • S and N co-doped graphene quantum dots (S,N-GQDs) were synthesized. • ZnO nanorods were grown on ITO coated flexible PET substrates. • S,N-GQDs were attached with ZnO nanorods and used as a green sensitizer. • Photosensing properties of S,N-GQD/ZnO and P3HT polymer hybrid device was studied.

  10. Insights into chemotaxonomic composition and carbon cycling of phototrophic communities in an artesian sulfur-rich spring (Zodletone, Oklahoma, USA), a possible analog for ancient microbial mat systems.

    Science.gov (United States)

    Bühring, S I; Sievert, S M; Jonkers, H M; Ertefai, T; Elshahed, M S; Krumholz, L R; Hinrichs, K-U

    2011-03-01

    Zodletone spring in Oklahoma is a unique environment with high concentrations of dissolved-sulfide (10 mm) and short-chain gaseous alkanes, exhibiting characteristics that are reminiscent of conditions that are thought to have existed in Earth's history, in particular the late Archean and early-to-mid Proterozoic. Here, we present a process-oriented investigation of the microbial community in two distinct mat formations at the spring source, (1) the top of the sediment in the source pool and (2) the purple streamers attached to the side walls. We applied a combination of pigment and lipid biomarker analyses, while functional activities were investigated in terms of oxygen production (microsensor analysis) and carbon utilization ((13)C incorporation experiments). Pigment analysis showed cyanobacterial pigments, in addition to pigments from purple sulfur bacteria (PSB), green sulfur bacteria (GSB) and Chloroflexus-like bacteria (CLB). Analysis of intact polar lipids (IPLs) in the source sediment confirmed the presence of phototrophic organisms via diacylglycerol phospholipids and betaine lipids, whereas glyceroldialkylglyceroltetraether additionally indicated the presence of archaea. No archaeal IPLs were found in the purple streamers, which were strongly dominated by betaine lipids. (13)C-bicarbonate- and -acetate-labeling experiments indicated cyanobacteria as predominant phototrophs in the source sediment, carbon was actively fixed by PSB/CLB/GSB in purple streamers by using near infrared light. Despite the presence of cyanobacteria, no oxygen could be detected in the presence of light, suggesting anoxygenic photosynthesis as the major metabolic process at this site. Our investigations furthermore indicated photoheterotrophy as an important process in both habitats. We obtained insights into a syntrophically operating phototrophic community in an ecosystem that bears resemblance to early Earth conditions, where cyanobacteria constitute an important contributor to

  11. Hybrid lithium-ion capacitor with LiFePO4/AC composite cathode - Long term cycle life study, rate effect and charge sharing analysis

    Science.gov (United States)

    Shellikeri, A.; Yturriaga, S.; Zheng, J. S.; Cao, W.; Hagen, M.; Read, J. A.; Jow, T. R.; Zheng, J. P.

    2018-07-01

    Energy storage devices, which can combine the advantages of lithium-ion battery with that of electric double layer capacitor, are of prime interest. Recently, composite cathodes, which combine a battery material with capacitor material, have shown promise in enhancing life cycle and energy/power performances. Lithium-ion capacitor (LIC), with unique charge storage mechanism of combining a pre-lithiated battery anode with a capacitor cathode, is one such device which has the potential to synergistically incorporate the composite cathode to enhance capacity and cycle life. We report here a hybrid LIC consisting of a lithium iron phosphate (LiFePO4-LFP)/Activated Carbon composite cathode in combination with a hard carbon anode, by integrating the cycle life and capacity enhancing strategies of a dry method of electrode fabrication, anode pre-lithiation and a 3:1 anode to cathode capacity ratio, demonstrating a long cycle life, while elaborating on the charge sharing between the faradaic and non-faradaic mechanism in the battery and capacitor materials, respectively in the composite cathode. An excellent cell capacity retention of 94% (1000 cycles at 1C) and 92% (100,000 cycles at 60C) were demonstrated, while retaining 78% (over 6000 cycles at 2.7C) and 67% (over 70,000 cycles at 43C) of the LFP capacity in the composite cathode.

  12. Process integration and optimization of a solid oxide fuel cell – Gas turbine hybrid cycle fueled with hydrothermally gasified waste biomass

    International Nuclear Information System (INIS)

    Facchinetti, Emanuele; Gassner, Martin; D’Amelio, Matilde; Marechal, François; Favrat, Daniel

    2012-01-01

    Due to its suitability for using wet biomass, hydrothermal gasification is a promising process for the valorization of otherwise unused waste biomass to synthesis gas and biofuels. Solid oxide fuel cell (SOFC) based hybrid cycles are considered as the best candidate for a more efficient and clean conversion of (bio) fuels. A significant potential for the integration of the two technologies is expected since hydrothermal gasification requires heat at 673–773 K, whereas SOFC is characterized by heat excess at high temperature due to the limited electrochemical fuel conversion. This work presents a systematic process integration and optimization of a SOFC-gas turbine (GT) hybrid cycle fueled with hydrothermally gasified waste biomass. Several design options are systematically developed and compared through a thermodynamic optimization approach based on First Law and exergy analysis. The work demonstrates the considerable potential of the system that allows for converting wet waste biomass into electricity at a First Law efficiency of up to 63%, while simultaneously enabling the separation of biogenic carbon dioxide for further use or sequestration. -- Highlights: ► Hydrothermal gasification is a promising process for the valorization of waste wet biomass. ► Solid Oxide Fuel Cell – Gas Turbine hybrid cycle emerges as the best candidates for conversion of biofuels. ► A systematic process integration and optimization of a SOFC-GT hybrid cycle fuelled with hydrothermally gasified biomass is presented. ► The system may convert wet waste biomass to electricity at a First Law efficiency of 63% while separating the biogenic carbon dioxide. ► The process integration enables to improve the First Law efficiency of around 4% with respect to a non-integrated system.

  13. 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.

  14. Evaluation and Comparison of Environmental Indicators of Hybrid Corn (Zea mays L. Production by Three Different Harvesting Methods in Alborz Province using Life Cycle Assessment

    Directory of Open Access Journals (Sweden)

    Majid Khanali

    2018-02-01

    Full Text Available Introduction Agriculture itself serves a dual role as an energy user and also energy supplier in the form of bio-energy. Recently, the energy use in agriculture has been intensified in response to the rising population, the increasing of standards of living and the limitation sources of energy. Efficient use of energy is a possible pathway for reducing the environmental impacts of energy inputs in agriculture, and providing sustainable agricultural production, since it brings financial savings, fossil resources preservation and air pollution reduction. Life cycle assessment (LCA is defined as the compilation and evaluation of the inputs, outputs and potential environmental impacts of a product system throughout its life cycle. Hybrid seed in agriculture is produced by cross-pollinated plants. Hybrid seed production is one of the main contributors to the dramatic rise in agricultural output during the last half of the 20th century. The alternatives to hybridization are open pollination and cloonal propagation. All of the hybrid seeds planted by the farmer will produce similar plants while the seeds of the next generation from those hybrids will not consistently have the desired characteristics. Controlled hybrids provide very uniform characteristics because they are produced by crossing two inbred strains. Materials and Methods The purpose of this study was to compare the energy consumption pattern and environmental consequences caused by the use of agricultural inputs in the production of seed corn harvested by hand, combine and picker husker. Information required was prepared by the questionnaire method in Alborz Province using census the total producers of hybrid corn in the Province. The investigated inputs were labor, agricultural machinery, diesel fuel, chemical pesticides, fertilizers, gas, electricity, water and seed. The energy of each input was calculated by multiplying the amount of that input with its energy equivalent. The ten

  15. 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.

  16. Genomic divergence and lack of introgressive hybridization between two 13-year periodical cicadas support life cycle switching in the face of climate change.

    Science.gov (United States)

    Koyama, Takuya; Ito, Hiromu; Fujisawa, Tomochika; Ikeda, Hiroshi; Kakishima, Satoshi; Cooley, John R; Simon, Chris; Yoshimura, Jin; Sota, Teiji

    2016-11-01

    Life history evolution spurred by post-Pleistocene climatic change is hypothesized to be responsible for the present diversity in periodical cicadas (Magicicada), but the mechanism of life cycle change has been controversial. To understand the divergence process of 13-year and 17-year cicada life cycles, we studied genetic relationships between two synchronously emerging, parapatric 13-year periodical cicada species in the Decim group, Magicicada tredecim and M. neotredecim. The latter was hypothesized to be of hybrid origin or to have switched from a 17-year cycle via developmental plasticity. Phylogenetic analysis using restriction-site-associated DNA sequences for all Decim species and broods revealed that the 13-year M. tredecim lineage is genomically distinct from 17-year Magicicada septendecim but that 13-year M. neotredecim is not. We detected no significant introgression between M. tredecim and M. neotredecim/M. septendecim thus refuting the hypothesis that M. neotredecim are products of hybridization between M. tredecim and M. septendecim. Further, we found that introgressive hybridization is very rare or absent in the contact zone between the two 13-year species evidenced by segregation patterns in single nucleotide polymorphisms, mitochondrial lineage identity and head width and abdominal sternite colour phenotypes. Our study demonstrates that the two 13-year Decim species are of independent origin and nearly completely reproductively isolated. Combining our data with increasing observations of occasional life cycle change in part of a cohort (e.g. 4-year acceleration of emergence in 17-year species), we suggest a pivotal role for developmental plasticity in Magicicada life cycle evolution. © 2016 John Wiley & Sons Ltd.

  17. EDDY RESOLVING NUTRIENT ECODYNAMICS IN THE GLOBAL PARALLEL OCEAN PROGRAM AND CONNECTIONS WITH TRACE GASES IN THE SULFUR, HALOGEN AND NMHC CYCLES

    Energy Technology Data Exchange (ETDEWEB)

    S. CHU; S. ELLIOTT

    2000-08-01

    Ecodynamics and the sea-air transfer of climate relevant trace gases are intimately coupled in the oceanic mixed layer. Ventilation of species such as dimethyl sulfide and methyl bromide constitutes a key linkage within the earth system. We are creating a research tool for the study of marine trace gas distributions by implementing coupled ecology-gas chemistry in the high resolution Parallel Ocean Program (POP). The fundamental circulation model is eddy resolving, with cell sizes averaging 0.15 degree (lat/long). Here we describe ecochemistry integration. Density dependent mortality and iron geochemistry have enhanced agreement with chlorophyll measurements. Indications are that dimethyl sulfide production rates must be adjusted for latitude dependence to match recent compilations. This may reflect the need for phytoplankton to conserve nitrogen by favoring sulfurous osmolytes. Global simulations are also available for carbonyl sulfide, the methyl halides and for nonmethane hydrocarbons. We discuss future applications including interaction with atmospheric chemistry models, high resolution biogeochemical snapshots and the study of open ocean fertilization.

  18. 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

  19. Impact of Spanish electricity mix, over the period 2008–2030, on the Life Cycle energy consumption and GHG emissions of Electric, Hybrid Diesel-Electric, Fuel Cell Hybrid and Diesel Bus of the Madrid Transportation System

    International Nuclear Information System (INIS)

    García Sánchez, Juan Antonio; López Martínez, José María; Lumbreras Martín, Julio; Flores Holgado, María Nuria; Aguilar Morales, Hansel

    2013-01-01

    Highlights: • We assess the performance of 4 buses that run on different alternative fuel types and technologies. • The buses assessed are Fuel Cell-Hybrid Bus, Hybrid Diesel-Electric Bus, Battery Electric Bus, and a Diesel Bus. • We examine the environmental impact caused by the Life Cycle of each vehicle technology, fossil fuel and energy carrier. • Life Cycle of Battery Electric Bus shows that it has a big potential of improvement in terms of environmental impact. - Abstract: In spite of the advanced research in automotive technology, and the improvement of fuels, the road transport sector continues to be an environmental concern, since the increase in transport demand is offsetting the effects of these technological improvements. Therefore, this poses the following question: what combination of technology and fuel is more efficient in terms of energy consumption and green house gas (GHG) emissions? To fully address this question it is necessary to carry out a Life Cycle Assessment (LCA). This paper presents a global LCA of 4 buses that run on the following fuel types and technologies: (1) Fuel Cell- Hybrid Bus, (2) Hybrid Diesel-Electric Bus (series configuration), (3) Battery Electric Bus and (4) Combustion Ignition Engine Bus. The impact categories assessed are: primary energy consumption, fossil energy and GHG emissions. Among the principal results, we can conclude that the Global LCA of buses (3) and (1) (which are the more sensitive pathways to the electricity mix variation) have for the 2008–2030 period a room for improvement of 25.62% and 28.16% in terms of efficiency of fossil energy consumption and a potential GHG emission reduction of 28.70% and 30.88% respectively

  20. Physiology and application of sulfur-reducing microorganisms from acidic environments

    NARCIS (Netherlands)

    Florentino, Anna Patrícya

    2017-01-01

    Sulfur cycle is one of the main geochemical cycles on Earth. Oxidation and reduction reactions of sulfur are mostly biotic and performed by microorganisms. In anaerobic conditions – marine and some freshwater systems, dissimilatory sulfur- and sulfate-reducing bacteria and archaea are key players

  1. Preservation of carbohydrates through sulfurization in a Jurassic euxinic shelf sea: Examination of the Blackstone Band TOC-cycle in the Kimmeridge Clay Formation, UK

    NARCIS (Netherlands)

    Dongen, B.E. van; Schouten, S.; Sinninghe Damsté, J.S.

    2006-01-01

    A complete total organic carbon (TOC) cycle in the Upper Jurassic Kimmeridge Clay Formation (KCF) comprising the extremely TOC-rich (34%) Blackstone Band was studied to investigate the controlling factors on TOC accumulation. Compared with the under- and overlying strata, TOC in the Blackstone

  2. Environmental, health, and safety issues of sodium-sulfur batteries for electric and hybrid vehicles. Volume 2, Battery recycling and disposal

    Energy Technology Data Exchange (ETDEWEB)

    Corbus, D

    1992-09-01

    Recycling and disposal of spent sodium-sulfur (Na/S) batteries are important issues that must be addressed as part of the commercialization process of Na/S battery-powered electric vehicles. The use of Na/S batteries in electric vehicles will result in significant environmental benefits, and the disposal of spent batteries should not detract from those benefits. In the United States, waste disposal is regulated under the Resource Conservation and Recovery Act (RCRA). Understanding these regulations will help in selecting recycling and disposal processes for Na/S batteries that are environmentally acceptable and cost effective. Treatment processes for spent Na/S battery wastes are in the beginning stages of development, so a final evaluation of the impact of RCRA regulations on these treatment processes is not possible. The objectives of tills report on battery recycling and disposal are as follows: Provide an overview of RCRA regulations and requirements as they apply to Na/S battery recycling and disposal so that battery developers can understand what is required of them to comply with these regulations; Analyze existing RCRA regulations for recycling and disposal and anticipated trends in these regulations and perform a preliminary regulatory analysis for potential battery disposal and recycling processes. This report assumes that long-term Na/S battery disposal processes will be capable of handling large quantities of spent batteries. The term disposal includes treatment processes that may incorporate recycling of battery constituents. The environmental regulations analyzed in this report are limited to US regulations. This report gives an overview of RCRA and discusses RCRA regulations governing Na/S battery disposal and a preliminary regulatory analysis for Na/S battery disposal.

  3. 1D Ni-Co oxide and sulfide nanoarray/carbon aerogel hybrid nanostructures for asymmetric supercapacitors with high energy density and excellent cycling stability.

    Science.gov (United States)

    Hao, Pin; Tian, Jian; Sang, Yuanhua; Tuan, Chia-Chi; Cui, Guanwei; Shi, Xifeng; Wong, C P; Tang, Bo; Liu, Hong

    2016-09-15

    The fabrication of supercapacitor electrodes with high energy density and excellent cycling stability is still a great challenge. A carbon aerogel, possessing a hierarchical porous structure, high specific surface area and electrical conductivity, is an ideal backbone to support transition metal oxides and bring hope to prepare electrodes with high energy density and excellent cycling stability. Therefore, NiCo 2 S 4 nanotube array/carbon aerogel and NiCo 2 O 4 nanoneedle array/carbon aerogel hybrid supercapacitor electrode materials were synthesized by assembling Ni-Co precursor needle arrays on the surface of the channel walls of hierarchical porous carbon aerogels derived from chitosan in this study. The 1D nanostructures grow on the channel surface of the carbon aerogel vertically and tightly, contributing to the enhanced electrochemical performance with ultrahigh energy density. The energy density of NiCo 2 S 4 nanotube array/carbon aerogel and NiCo 2 O 4 nanoneedle array/carbon aerogel hybrid asymmetric supercapacitors can reach up to 55.3 Wh kg -1 and 47.5 Wh kg -1 at a power density of 400 W kg -1 , respectively. These asymmetric devices also displayed excellent cycling stability with a capacitance retention of about 96.6% and 92% over 5000 cycles.

  4. 700 F hybrid capacitors cells composed of activated carbon and Li4Ti5O12 microspheres with ultra-long cycle life

    Science.gov (United States)

    Ruan, Dianbo; Kim, Myeong-Seong; Yang, Bin; Qin, Jun; Kim, Kwang-Bum; Lee, Sang-Hyun; Liu, Qiuxiang; Tan, Lei; Qiao, Zhijun

    2017-10-01

    To address the large-scale application demands of high energy density, high power density, and long cycle lifetime, 700-F hybrid capacitor pouch cells have been prepared, comprising ∼240-μm-thick activated carbon cathodes, and ∼60-μm-thick Li4Ti5O12 anodes. Microspherical Li4Ti5O12 (M-LTO) synthesized by spray-drying features 200-400 nm primary particles and interconnected nanopore structures. M-LTO half-cells exhibits high specific capacities (175 mAhh g-1), good rate capabilities (148 mAhh g-1 at 20 C), and ultra-long cycling stabilities (90% specific capacity retention after 10,000 cycles). In addition, the obtained hybrid capacitors comprising activated carbon (AC) and M-LTO shows excellent cell performances, achieving a maximum energy density of 51.65 Wh kg-1, a maximum power density of 2466 W kg-1, and ∼92% capacitance retention after 10,000 cycles, thus meeting the demands for large-scale applications such as trolleybuses.

  5. 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.

  6. Proposal of a combined heat and power plant hybridized with regeneration organic Rankine cycle: Energy-Exergy evaluation

    International Nuclear Information System (INIS)

    Anvari, Simin; Jafarmadar, Samad; Khalilarya, Shahram

    2016-01-01

    Highlights: • A new thermodynamic cogeneration system is proposed. • Energy and exergy analysis of the considered cycle were performed. • An enhancement of 2.6% in exergy efficiency compared to that of baseline cycle. - Abstract: Among Rankine cycles (simple, reheat and regeneration), regeneration organic Rankine cycle demonstrates higher efficiencies compared to other cases. Consequently, in the present work a regeneration organic Rankine cycle has been utilized to recuperate gas turbine’s heat using heat recovery steam generator. At first, this cogeneration system was subjected to energy and exergy analysis and the obtained results were compared with that of investigated cogeneration found in literature (a cogeneration system in which a reheat organic Rankine cycle for heat recuperation of gas turbine cycle was used with the aid of heat recovery steam generator). Results indicated that the first and second thermodynamic efficiencies in present cycle utilizing regeneration cycle instead of reheat cycle has increased 2.62% and 2.6%, respectively. In addition, the effect of thermodynamic parameters such as combustion chamber’s inlet temperature, gas turbine inlet temperature, evaporator and condenser temperature on the energetic and exergetic efficiencies of gas turbine-heat recovery steam generator cycle and gas turbine-heat recovery steam generator cycle with regeneration organic Rankine cycle was surveyed. Besides, parametric analysis shows that as gas turbine and combustion chamber inlet temperatures increase, energetic and exergetic efficiencies tend to increase. Moreover, once condenser and evaporator temperature raise, a slight decrement in energetic and exergetic efficiency is expected.

  7. 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.

  8. 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.

  9. 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.

  10. 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.)

  11. Thermodynamic Analysis of an Integrated Solid Oxide Fuel Cell Cycle with a Rankine Cycle

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2010-01-01

    Hybrid systems consisting of Solid Oxide Fuel Cells (SOFC) on the top of a Steam Turbine (ST) are investigated. The plants are fired by natural gas (NG). A desulfurization reactor removes the sulfur content in the fuel while a pre-reformer breaks down the heavier hydrocarbons. The pre-treated fuel......% are achieved which is considerably higher than the conventional Combined Cycles (CC). Both ASR (Adiabatic Steam Reformer) and CPO (Catalytic Partial Oxidation) fuel pre-reformer reactors are considered in this investigation....

  12. High cycle fatigue behavior of the IN718/M247 hybrid element fabricated by friction welding at elevated temperatures

    Directory of Open Access Journals (Sweden)

    Tran Hung Tra

    2016-12-01

    Full Text Available A hybrid element has been fabricated by friction welding, joining two superalloys Inconel 718 and Mar-M247. The high cycle fatigue behavior of this welded element was investigated at 500 °C and 700 °C. The fabrication could obtain excellent fatigue strength in which the fracture is located in the base metal Mar-M247 side and takes place outside the welded zone. The behavior of the joint under loadings is discussed through a simulation by the numerical finite element method.

  13. 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).

  14. 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.

  15. 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

  16. 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

  17. 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...

  18. Environmental assessment of plug-in hybrid electric vehicles using naturalistic drive cycles and vehicle travel patterns: A Michigan case study

    International Nuclear Information System (INIS)

    Marshall, Brandon M.; Kelly, Jarod C.; Lee, Tae-Kyung; Keoleian, Gregory A.; Filipi, Zoran

    2013-01-01

    Plug-in hybrid electric vehicles (PHEVs) use grid electricity as well as on-board gasoline for motive force. These multiple energy sources make prediction of PHEV energy consumption challenging and also complicate evaluation of their environmental impacts. This paper introduces a novel PHEV energy consumption modeling approach and compares it to a second approach from the literature, each using actual trip patterns from the 2009 National Household Travel Survey (NHTS). The first approach applies distance-dependent fuel efficiency and on-road electricity consumption rates based on naturalistic or real world, driving information to determine gasoline and electricity consumption. The second uses consumption rates derived in accordance with government certification testing. Both approaches are applied in the context of a location-specific case study that focuses on the state of Michigan. The two PHEV models show agreement in electricity demand due to vehicle charging, gasoline consumption, and life cycle environmental impacts for this case study. The naturalistic drive cycle approach is explored as a means of extending location-specific driving data to supplement existing PHEV impact assessments methods. - Highlights: • Travel patterns from survey data are combined with naturalistic drive cycles. • More realistic PHEV energy modeling using these synthesized real-world drive cycles. • Methodology is demonstrated for PHEVs in Michigan but applicable for other regions. • Energy and emissions findings have major implications for PHEV standards and policy

  19. Freeway Driving Cycle Construction Based on Real-Time Traffic Information and Global Optimal Energy Management for Plug-In Hybrid Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Hongwen He

    2017-11-01

    Full Text Available This paper presents a freeway driving cycle (FDC construction method based on traffic information. A float car collected different type of roads in California and we built a velocity fragment database. We selected a real freeway driving cycle (RFDC and established the corresponding time traffic information tensor model by using the data in California Department of Transportation performance measure system (PeMS. The correlation of road velocity in the time dimension and spatial dimension are analyzed. According to the average velocity of road sections at different times, the kinematic fragments are stochastically selected in the velocity fragment database to construct a real-time FDC of each section. The comparison between construction freeway driving cycle (CFDC and real freeway driving cycle (RFDC show that the CFDC well reflects the RFDC characteristic parameters. Compared to its application in plug-in electric hybrid vehicle (PHEV optimal energy management based on a dynamic programming (DP algorithm, CFDC and RFDC fuel consumption are similar within approximately 5.09% error, and non-rush hour fuel economy is better than rush hour 3.51 (L/100 km at non-rush hour, 4.29 (L/km at rush hour. Moreover, the fuel consumption ratio can be up to 13.17% in the same CFDC at non-rush hour.

  20. Greenhouse gas implications of using coal for transportation: Life cycle assessment of coal-to-liquids, plug-in hybrids, and hydrogen pathways

    International Nuclear Information System (INIS)

    Jaramillo, Paulina; Samaras, Constantine; Wakeley, Heather; Meisterling, Kyle

    2009-01-01

    Using coal to produce transportation fuels could improve the energy security of the United States by replacing some of the demand for imported petroleum. Because of concerns regarding climate change and the high greenhouse gas (GHG) emissions associated with conventional coal use, policies to encourage pathways that utilize coal for transportation should seek to reduce GHGs compared to petroleum fuels. This paper compares the GHG emissions of coal-to-liquid (CTL) fuels to the emissions of plug-in hybrid electric vehicles (PHEV) powered with coal-based electricity, and to the emissions of a fuel cell vehicle (FCV) that uses coal-based hydrogen. A life cycle approach is used to account for fuel cycle and use-phase emissions, as well as vehicle cycle and battery manufacturing emissions. This analysis allows policymakers to better identify benefits or disadvantages of an energy future that includes coal as a transportation fuel. We find that PHEVs could reduce vehicle life cycle GHG emissions by up to about one-half when coal with carbon capture and sequestration is used to generate the electricity used by the vehicles. On the other hand, CTL fuels and coal-based hydrogen would likely lead to significantly increased emissions compared to PHEVs and conventional vehicles using petroleum-based fuels.

  1. Selection of appropriate working fluids for Rankine cycles used for recovery of heat from exhaust gases of ICE in heavy-duty series hybrid electric vehicles

    International Nuclear Information System (INIS)

    Jung, Daebong; Park, Sungjin; Min, Kyoungdoug

    2015-01-01

    Recently, the waste heat recovery system is studied for application in vehicles to improve fuel economy. Especially, Rankine cycle is representative and attractive technology as waste heat recovery system. In order to maximize efficiency of Rankine cycle in the vehicle application, selection of optimal working fluid is important. Thus, in this study, thermodynamic analysis with consideration of practical operating condition was conducted to find out optimal working fluids. Thermodynamic efficiency, recovery efficiency, and overall cycle efficiency were adopted to estimate Rankine cycle performance. In order to reflect practical operating condition on the analysis, limitations due to working fluid physical properties and components specifications are taken into account. 5 working fluids including dry and wet fluid were used to estimate efficiency. Consequently, R245fa which shows high efficiency and environment-friendly is suggested as optimal working fluid in vehicle application. - Highlights: • 5 different working fluids were analyzed in respect of hybrid electric vehicle waste heat recovery system. • Real world operational conditions and limits are applied. • Optimal heating temperature of each working fluid show different trend. • R245fa is preferable among other fluids due to its high efficiency and impact on environment

  2. Driving cycle suitable layout of permanent magnet synchronous machines for hybrid vehicles and electric powered vehicles; Fahrzyklusgerechte Auslegung von permanentmagneterregten Synchronmaschinen fuer Hybrid- und Elektrofahrzeuge

    Energy Technology Data Exchange (ETDEWEB)

    Finken, Thomas

    2011-07-01

    An increasing environmental awareness and the prospect of a shortage of fossil resources will result in a development of efficient vehicles with a lower consumption of fuel. In addition to the hybrid electric vehicle, the electric powered vehicle increasingly is focused in the development of vehicles. A good efficiency is the most important demand on the electrical machine. The author of the book under consideration reports on exemplary operating point distributions for various vehicle concepts and user profiles. After comparing the most common types of machine in terms of the use in electrified powertrains, the permanent magnet synchronous machine is selected and discussed in detail. A table shows the advantages and disadvantages of all considered geometries and variations. Thus, a suitable combination of geometry for a given vehicle concept and its requirements are selected.

  3. Theoretical studies of a hybrid ejector CO2 compression cooling system for vehicles and preliminary experimental investigations of an ejector cycle

    International Nuclear Information System (INIS)

    Chen, Xiangjie; Worall, Mark; Omer, Siddig; Su, Yuehong; Riffat, Saffa

    2013-01-01

    Highlights: ► Waste heat from vehicle exhausted gas was used as heat source for ejector. ► Ejector acts as the main interface between ejector and CO 2 VC sub-system. ► The effect of sub-cooling was analyzed. ► COP of ejector cooling system was measured between 0.2 and 0.5 during experiments. ► Enhanced ejector and vapour compression system. -- Abstract: This paper presents theoretical investigations into a hybrid ejector and CO 2 vapour compression (VC) system for road transport cooling. The purpose is to utilise the waste heat from exhaust gas and the VC sub-system to drive the ejector system, whose cooling effect will be employed to subcool the VC sub-system. Exploitation of the energy consumption ratio between ejector sub-system and CO 2 VC sub-system indicated that the more energy obtained from exhausted gas, the better system performance could be achieved for CO 2 VC sub-system, and hence higher cooling capacity of the VC sub-system at the same compression power. Thermodynamic simulations of two sub-systems and the hybrid system were presented. The results indicated that, at boiler temperature of 120 °C, evaporator temperature of 10 °C, a COP of 0.584 was achieved for hybrid system, with 22% improvement over a single ejector cycle. Preliminary experimental studies were carried out on a single ejector cycle, with boiler temperatures between 115 °C and 130 °C, and evaporator temperatures between 5 °C and 10 °C. The effects of various operation conditions on the overall ejector operation were coherently analysed. The COP of the ejector sub-system from experimental results was approximately 85% compared with simulation results, which showed a good agreement between theoretical analysis and experimental results.

  4. 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.

  5. 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

  6. Synthesis of a Flexible Freestanding Sulfur/Polyacrylonitrile/Graphene Oxide as the Cathode for Lithium/Sulfur Batteries

    Directory of Open Access Journals (Sweden)

    Huifen Peng

    2018-04-01

    Full Text Available Rechargeable lithium/sulfur (Li/S batteries have received quite significant attention over the years because of their high theoretical specific capacity (1672 mAh·g−1 and energy density (2600 mAh·g−1 which has led to more efforts for improvement in their electrochemical performance. Herein, the synthesis of a flexible freestanding sulfur/polyacrylonitrile/graphene oxide (S/PAN/GO as the cathode for Li/S batteries by simple method via vacuum filtration is reported. The S/PAN/GO hybrid binder-free electrode is considered as one of the most promising cathodes for Li/S batteries. Graphene oxide (GO slice structure provides effective ion conductivity channels and increases structural stability of the ternary system, resulting in excellent electrochemical properties of the freestanding S/PAN/GO cathode. Additionally, graphene oxide (GO membrane was able to minimize the polysulfides’ dissolution and their shuttle, which was attributed to the electrostatic interactions between the negatively-charged species and the oxygen functional groups on GO. Furthermore, these oxygen-containing functional groups including carboxyl, epoxide and hydroxyl groups provide active sites for coordination with inorganic materials (such as sulfur. It exhibits the initial reversible specific capacity of 1379 mAh·g−1 at a constant current rate of 0.2 C and maintains 1205 mAh·g−1 over 100 cycles (~87% retention. In addition, the freestanding S/PAN/GO cathode displays excellent coulombic efficiency (~100% and rate capability, delivering up to 685 mAh·g−1 capacity at 2 C.

  7. Construction of tubular polypyrrole-wrapped biomass-derived carbon nanospheres as cathode materials for lithium–sulfur batteries

    International Nuclear Information System (INIS)

    Yu, Qiuhong; Lu, Yang; Peng, Tao; Hou, Xiaoyi; Luo, Rongjie; Wang, Yange; Yan, Hailong; Luo, Yongsong; Liu, Xianming; Kim, Jang-Kyo

    2017-01-01

    A promising hybrid material composed of tubular polypyrrole (T-PPy)-wrapped monodisperse biomass-derived carbon nanospheres (BCSs) was first synthesized successfully via a simple hydrothermal approach by using watermelon juice as the carbon source, and further used as an anchoring object for sulfur (S) of lithium–sulfur (Li–S) batteries. The use of BCSs with hydrophilic nature as a framework could provide large interface areas between the active materials and electrolyte, and improve the dispersion of T-PPy, which could help in the active material utilization. As a result, BCS@T-PPy/S as a cathode material exhibited a high capacity of 1143.6 mA h g −1 and delivered a stable capacity up to 685.8 mA h g −1 after 500 cycles at 0.5 C, demonstrating its promising application for rechargeable Li–S batteries. (paper)

  8. 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

  9. A hybrid solar photovoltaic-wind turbine-Rankine cycle for electricity generation in Turkish Republic of Northern Cyprus

    Directory of Open Access Journals (Sweden)

    Samuel Asumadu-Sarkodie

    2016-12-01

    Full Text Available This paper presents an energy demand model by designing a hybrid solar-wind-thermal power generation system of the Turkish Republic of Northern Cyprus, a promising substitute for the expensive battery banks. The study models the future energy demand of Turkish Republic of Northern Cyprus based on the IPCC emissions scenario A1B and A2 by designing a new hybrid solar-wind-thermal power system that satisfies the current and future requirements of firm capacity during peak periods. The study suggests an improvement in a hybrid solar-wind-thermal power system performance by predicting reliable outputs that can integrate renewable energy technologies to conventional power generation. The energy consumption prediction model emphasizes the energy requirement that has a growing demand from 300 to 400 GWh in scenario A1B and 150–450 GWh in scenario A2 from 2010 to 2050. The proposed design can meet 400 GWh of electricity demand in TRNC based on IPCC scenario A1B and 450 GWh of electricity demand in TRNC based on IPCC scenario A2. The percentage contribution of solar, wind and thermal energy for 2010, 2020, 2030, 2040 and 2050 are presented along with CO2 emissions and water consumption for each of the years.

  10. Pre-design and life cycle cost analysis of a hybrid power system for rural and remote communities in Afghanistan

    Directory of Open Access Journals (Sweden)

    Mir Sayed Shah Danish

    2014-08-01

    Full Text Available In view of the present situation of the Afghanistan electricity sector, the photovoltaic and diesel generator stand-alone hybrid power system is increasingly attractive for application in rural and remote communities. Thousands of rural communities in Afghanistan depend solely on traditional kerosene for illumination and rarely have access to electricity sources such as DC battery for radio and other small appliances. This study is conducted to offer real-life solution to this problem. The hybrid system is investigated to meet the domestic load demand that is estimated based on the communities’ electricity consumption culture. At first, customary pre-design is pursued. Afterwards, the break-even point and net present value algorithms are applied for economic analysis. That makes this study differ from the previous academic literature. The concepts developed in this study are targeted for a cost-effective hybrid system, which is appropriate for rural and remote residents’ lifestyle change and improvement. Based on the academic research methods, overall analysis procedures can fit as an analogy, especially for developing countries.

  11. Multilayer Approach for Advanced Hybrid Lithium Battery

    KAUST Repository

    Ming, Jun

    2016-06-06

    Conventional intercalated rechargeable batteries have shown their capacity limit, and the development of an alternative battery system with higher capacity is strongly needed for sustainable electrical vehicles and hand-held devices. Herein, we introduce a feasible and scalable multilayer approach to fabricate a promising hybrid lithium battery with superior capacity and multivoltage plateaus. A sulfur-rich electrode (90 wt % S) is covered by a dual layer of graphite/Li4Ti5O12, where the active materials S and Li4Ti5O12 can both take part in redox reactions and thus deliver a high capacity of 572 mAh gcathode -1 (vs the total mass of electrode) or 1866 mAh gs -1 (vs the mass of sulfur) at 0.1C (with the definition of 1C = 1675 mA gs -1). The battery shows unique voltage platforms at 2.35 and 2.1 V, contributed from S, and 1.55 V from Li4Ti5O12. A high rate capability of 566 mAh gcathode -1 at 0.25C and 376 mAh gcathode -1 at 1C with durable cycle ability over 100 cycles can be achieved. Operando Raman and electron microscope analysis confirm that the graphite/Li4Ti5O12 layer slows the dissolution/migration of polysulfides, thereby giving rise to a higher sulfur utilization and a slower capacity decay. This advanced hybrid battery with a multilayer concept for marrying different voltage plateaus from various electrode materials opens a way of providing tunable capacity and multiple voltage platforms for energy device applications. © 2016 American Chemical Society.

  12. Some information needs for air quality modeling. [Environmental effects of sulfur compounds

    Energy Technology Data Exchange (ETDEWEB)

    Hill, F B

    1975-09-01

    The following topics were considered at the workshop: perturbation of the natural sulfur cycle by human activity; ecosystem responses to a given environmental dose of sulfur compounds; movement of sulfur compounds within the atmosphere; air quality models; contribution of biogenic sulfur compounds to atmospheric burden of sulfur; production of acid rain from sulfur dioxide; meteorological processes; and rates of oxidation of SO/sub 2/ via direct photo-oxidation, oxidation resulting from photo-induced free radical chemistry, and catalytic oxidation in cloud droplets and on dry particles. (HLW)

  13. Life cycle environmental assessment of lithium-ion and nickel metal hydride batteries for plug-in hybrid and battery electric vehicles.

    Science.gov (United States)

    Majeau-Bettez, Guillaume; Hawkins, Troy R; Strømman, Anders Hammer

    2011-05-15

    This study presents the life cycle assessment (LCA) of three batteries for plug-in hybrid and full performance battery electric vehicles. A transparent life cycle inventory (LCI) was compiled in a component-wise manner for nickel metal hydride (NiMH), nickel cobalt manganese lithium-ion (NCM), and iron phosphate lithium-ion (LFP) batteries. The battery systems were investigated with a functional unit based on energy storage, and environmental impacts were analyzed using midpoint indicators. On a per-storage basis, the NiMH technology was found to have the highest environmental impact, followed by NCM and then LFP, for all categories considered except ozone depletion potential. We found higher life cycle global warming emissions than have been previously reported. Detailed contribution and structural path analyses allowed for the identification of the different processes and value-chains most directly responsible for these emissions. This article contributes a public and detailed inventory, which can be easily be adapted to any powertrain, along with readily usable environmental performance assessments.

  14. Life-cycle assessment of a Solar Assist Plug-in Hybrid electric Tractor (SAPHT) in comparison with a conventional tractor

    International Nuclear Information System (INIS)

    Mousazadeh, Hossein; Keyhani, Alireza; Javadi, Arzhang; Mobli, Hossein; Abrinia, Karen; Sharifi, Ahmad

    2011-01-01

    The most well-known reason of global warming is equivalent carbon dioxide (CO 2equ ) emitted from fossil fuels combustion in on-road and off-road vehicles. An appreciable portion of off-road pollution is allocated to farm implements. All cited studies have shown that renewable based electric vehicles (EVs) decrease petroleum consumption and consequently reduce criteria emissions under nearly all circumstances. Considering this, a Solar Assist Plug-in Hybrid electric Tractor (SAPHT) was designed, constructed and evaluated. This research evaluated the life cycle analysis of SAPHT project and compared the results with that of an internal combustion engine tractor (ICET). The life cycle was analyzed based on economical cost and environmental emissions. The externality of environmental pollutions was calculated to derive the life-cycle costs (LCC). The results showed that substituting each ICET by SAPHT can prevent 14 ton CO 2equ emission to atmosphere annually. Also it prevents a high volume of other emissions such as CO, NO x and PM 10 entering the atmosphere. LCC assessment emphasizes on economical effectiveness of SAPHT rather than ICET at any diesel fuel price, therefore, increasing fuel unit prices leads to more effectiveness. It is concluded that levelized cost of energy (LCE) in Euro /kW h for ICET is almost twice as that of SAPHT. Some of these advantages for SAPHT are offset in part by high purchase costs, heavy and massive batteries and low operating range.

  15. High Capacitive Storage Performance of Sulfur and Nitrogen Codoped Mesoporous Graphene.

    Science.gov (United States)

    Ma, Xinlong; Gao, Daowei

    2018-03-22

    Mesoporous graphene is synthesized based on the chemical vapor deposition methodology by using heavy MgO flakes as substrates in a fluidized-bed reactor. Subsequently, sulfur and nitrogen coincorporation into graphene frameworks is realized by the reaction between carbon atoms and thiourea molecules. The as-obtained sulfur and nitrogen codoped mesoporous graphene (SNMG) exhibits remarkable capacitive energy-storage behavior, as a result of well-developed pore channels, in terms of that in a symmetric supercapacitor and lithium-ion hybrid capacitor (LIHC). The ultrahigh durability of the SNMG/SNMG symmetric supercapacitor is demonstrated by long-term cycling, for which no capacitance decay is found after 20 000 cycles. A LIHC constructed from commercial Li 4 Ti 5 O 12 (LTO) as the anode and SNMG as the cathode is capable of delivering much enhanced lithium-storage ability and better rate capability than that of activated carbon (AC)/LTO LIHC. Moreover, SNMG/LTO LIHC exhibits maximum energy and power densities of 86.2 Wh kg -1 and 7443 W kg -1 and maintains 87 % capacitance retention after 2000 cycles. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. A hybrid algorithm for solving the economic lot and delivery scheduling problem in the common cycle case

    DEFF Research Database (Denmark)

    Clausen, Jens; Ju, S.

    2006-01-01

    The ELDSP problem is a combined lot sizing and sequencing problem. A supplier produces and delivers components of different types to a consumer in batches. The task is to determine the cycle time, i.e., the time between deliveries, which minimizes the total cost per time unit. This includes the d...

  17. The Evolutionary History Of The White-Rayed Species Of Melampodium (Asteraceae) Involved Multiple Cycles Of Hybridization And Polyploidization1

    Science.gov (United States)

    Rebernig, Carolin A.; Weiss-Schneeweiss, Hanna; Blöch, Cordula; Turner, Barbara; Stuessy, Tod F.; Obermayer, Renate; Villaseñor, Jose L.; Schneeweiss, Gerald M.

    2014-01-01

    Premise of the study Polyploidy plays an important role in race differentiation and eventually speciation. Underlying mechanisms include chromosomal and genomic changes facilitating reproductive isolation and/or stabilization of hybrids. A prerequisite for studying these processes is a sound knowledge on the origin of polyploids. A well-suited group for studying polyploid evolution consists of the three species of Melampodium ser. Leucantha (Asteraceae): M. argophyllum, M. cinereum, and M. leucanthum. Methods The origin of polyploids was inferred using network and tree-based phylogenetic analyses of several plastid and nuclear DNA sequences and of fingerprint data (AFLP). Genome evolution was assessed via genome size measurements, karyotype analysis, and in situ hybridization of ribosomal DNA. Key results Tetraploid cytotypes of the phylogenetically distinct M. cinereum and M. leucanthum had, compared to the diploid cytotypes, doubled genome sizes and no evidence of gross chromosomal rearrangements. Hexaploid M. argophyllum constituted a separate lineage with limited intermixing with the other species, except in analyses from nuclear ITS. Its genome size was lower than expected if M. cinereum and/or M. leucanthum were involved in its origin, and no chromosomal rearrangements were evident. Conclusions Polyploids in M. cinereum and M. leucanthum are of recent autopolyploid origin in line with the lack of significant genomic changes. Hexaploid M. argophyllum also appears to be of autopolyploid origin against the previous hypothesis of an allopolyploid origin involving the other two species, but some gene flow with the other species in early phases of differentiation cannot be excluded. PMID:22645096

  18. Optimizing an advanced hybrid of solar-assisted supercritical CO2 Brayton cycle: A vital transition for low-carbon power generation industry

    International Nuclear Information System (INIS)

    Milani, Dia; Luu, Minh Tri; McNaughton, Robbie; Abbas, Ali

    2017-01-01

    Highlights: • The layout of 14 demonstrative supercritical CO 2 closed Brayton cycles are analysed. • The key parameters of the “combined” cycle are sensitized and optimized. • The effect of thermal efficiency vs HX area on techno-economic nexus is highlighted. • The design of a matching solar heliostat field in direct configuration is revealed. • The water demand for hybrid vs water-only cooling scenarios are assessed. - Abstract: Current worldwide infrastructure of electrical power generation would mostly continue to rely on fossil-fuel but require a modest transition for the ultimate goal of decarbonizing power generation industry. By relying on those already established and carefully managed centrepiece power plants (PPs), we aim at filling the deficits of the current electrical networks with smaller, cleaner, and also more efficient PPs. In this context, we present a unique model for a small-scale decentralized solar-assisted supercritical CO 2 closed Brayton cycle (sCO 2 -CBC). Our model is based on the optimized values of three key performance indicators (KPIs); thermal efficiency, concentrated solar power (CSP) compatibility, and water demand for cooling. For a case-study of 10 MW e CSP-assisted sCO 2 -CBC power plant, our dynamic model shows a 52.7% thermal efficiency and 25.9% solar penetration and up to 80% of water saving in heat-rejection units. These KPIs show significant promise of the solar-assisted supercritical CO 2 power cycle for an imperative transformation in the power industry towards future sustainable electricity generation.

  19. 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.

  20. Optimal allocation and sizing of PV/Wind/Split-diesel/Battery hybrid energy system for minimizing life cycle cost, carbon emission and dump energy of remote residential building

    International Nuclear Information System (INIS)

    Ogunjuyigbe, A.S.O.; Ayodele, T.R.; Akinola, O.A.

    2016-01-01

    Highlights: • Genetic Algorithm is used for tri-objective design of hybrid energy system. • The objective is minimizing the Life Cycle Cost, CO_2 emissions and dump energy. • Small split diesel generators are used in place of big single diesel generator. • The split diesel generators are aggregable based on certain set of rules. • The proposed algorithm achieves the set objectives (LCC, CO_2 emission and dump). - Abstract: In this paper, a Genetic Algorithm (GA) is utilized to implement a tri-objective design of a grid independent PV/Wind/Split-diesel/Battery hybrid energy system for a typical residential building with the objective of minimizing the Life Cycle Cost (LCC), CO_2 emissions and dump energy. To achieve some of these objectives, small split Diesel generators are used in place of single big Diesel generator and are aggregable based on certain set of rules depending on available renewable energy resources and state of charge of the battery. The algorithm was utilized to study five scenarios (PV/Battery, Wind/Battery, Single big Diesel generator, aggregable 3-split Diesel generators, PV/Wind/Split-diesel/Battery) for a typical load profile of a residential house using typical wind and solar radiation data. The results obtained revealed that the PV/Wind/Split-diesel/Battery is the most attractive scenario (optimal) having LCC of $11,273, COE of 0.13 ($/kW h), net dump energy of 3 MW h, and net CO_2 emission of 13,273 kg. It offers 46%, 28%, 82% and 94% reduction in LCC, COE, CO_2 emission and dump energy respectively when compared to a single big Diesel generator scenario.

  1. A nonlinear look at trend MFP growth and the business cycle: result from a hybrid Kalman/Markov switching model

    OpenAIRE

    Mark W. French

    2005-01-01

    The cycle in output and hours worked is not symmetric: it behaves differently around recessions than in expansions. Similarly, the trend in multifactor productivity (MFP) seems to pass through different regimes; there was an extended period of slow MFP growth from about 1973 through 1995, and faster growth thereafter. Typical linear models and linear filters such as the Kalman filter deal poorly with asymmetry and regime changes. This paper attempts to determine more accurately and quickly an...

  2. Coupling of copper-chloride hybrid thermochemical water splitting cycle with a desalination plant for hydrogen production from nuclear energy

    International Nuclear Information System (INIS)

    Orhan, Mehmet F.; Dincer, Ibrahim; Naterer, Greg F.; Rosen, Marc A.

    2010-01-01

    Energy and environmental concerns have motivated research on clean energy resources. Nuclear energy has the potential to provide a significant share of energy supply without contributing to environmental emissions and climate change. Nuclear energy has been used mainly for electric power generation, but hydrogen production via thermochemical water decomposition provides another pathway for the utilization of nuclear thermal energy. One option for nuclear-based hydrogen production via thermochemical water decomposition uses a copper-chloride (Cu-Cl) cycle. Another societal concern relates to supplies of fresh water. Thus, to avoid causing one problem while solving another, hydrogen could be produced from seawater rather than limited fresh water sources. In this study we analyze a coupling of the Cu-Cl cycle with a desalination plant for hydrogen production from nuclear energy and seawater. Desalination technologies are reviewed comprehensively to determine the most appropriate option for the Cu-Cl cycle and a thermodynamic analysis and several parametric studies of this coupled system are presented for various configurations. (author)

  3. 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.

  4. Atmospheric sulfur and climate changes: a modelling study at mid and high-southern latitudes

    International Nuclear Information System (INIS)

    Castebrunet, H.

    2007-09-01

    The mid and high-southern latitudes are still marginally affected by anthropogenic sulfur emissions. They are the only regions in the world where the natural cycle of the atmospheric sulfur may still be observed. Sulfur aerosols are well-known for their radiative impact, and thus interact with climate. Climate can in turn affect atmospheric sulfur sources, distribution and chemistry. Antarctic ice cores provide information on the evolution of climate and sulfur deposition at the surface of the ice sheet at glacial-interglacial time scales. The aim of this thesis is to develop and use modeling towards a better understanding of the atmospheric sulfur cycle in antarctic and sub-antarctic regions. Ice core data are used to validate model results under glacial climate conditions. An Atmospheric General Circulation Model (AGCM) coupled to a sulfur chemistry module is used: the LMD-ZTSulfur model, version 4. An update of both the physical and chemical parts of the model. The model was first performed. The impact of there changes on modelled sulfur cycle are evaluated for modern climate. Further, boundary conditions are adapted to simulate the atmospheric circulation and sulfur cycle at the Last Glacial Maximum, approximately 20,000 years ago. In the model, sulfur is found to be highly sensitive to antarctic sea-ice coverage, which is still poorly known during the ice age. An original dataset of ice-age sea-ice coverage was developed. Its impact on the oceanic emissions of dimethyl sulfide, main precursor of sulfur aerosols at high-southern latitudes, is discussed. Using the same oceanic sulfur reservoirs as for present day climate, the model broadly reproduces the glacial deposits of sulfur aerosols on the Antarctic plateau, suggesting little impact of climate on oceanic sulfur production in the Antarctic region. Sensitivity tests were carried out to draw an up-to-date status of major uncertainties and difficulties facing future progress in understanding atmospheric

  5. Effects of hybrid cycling versus handcycling on wheelchair-specific fitness and physical activity in people with long-term spinal cord injury : a 16-week randomized controlled trial

    NARCIS (Netherlands)

    Bakkum, A. J. T.; de Groot, S.; Stolwijk-Swuste, J. M.; van Kuppevelt, D. J.; van der Woude, L. H. V.; Janssen, T. W. J.

    Study design: This is an open randomized controlled trial. Objective: The objective of this study was to investigate the effects of a 16-week hybrid cycle versus handcycle exercise program on fitness and physical activity in inactive people with long-term spinal cord injury (SCI). Setting: The study

  6. Effects of hybrid cycling versus handcycling on wheelchair-specific fitness and physical activity in people with long-term spinal cord injury: a 16-week randomized controlled trial

    NARCIS (Netherlands)

    Bakkum, A.J.T.; de Groot, S.; Stolwijk-Swuste, J.M.; van Kuppevelt, D.J.; van der Woude, L.H.V.; Janssen, T.W.J.

    2015-01-01

    Study design:This is an open randomized controlled trial.Objective:The objective of this study was to investigate the effects of a 16-week hybrid cycle versus handcycle exercise program on fitness and physical activity in inactive people with long-term spinal cord injury (SCI).Setting:The study was

  7. 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.

  8. Combination of equilibrium models and hybrid life cycle-input–output analysis to predict the environmental impacts of energy policy scenarios

    International Nuclear Information System (INIS)

    Igos, Elorri; Rugani, Benedetto; Rege, Sameer; Benetto, Enrico; Drouet, Laurent; Zachary, Daniel S.

    2015-01-01

    Highlights: • The environmental impacts of two energy policy scenarios in Luxembourg are assessed. • Computable General Equilibrium (CGE) and Partial Equilibrium (PE) models are used. • Results from coupling of CGE and PE are integrated in hybrid Life Cycle Assessment. • Impacts due to energy related production and imports are likely to grow over time. • Carbon mitigation policies seem to not substantially decrease the impacts’ trend. - Abstract: Nowadays, many countries adopt an active agenda to mitigate the impact of greenhouse gas emissions by moving towards less polluting energy generation technologies. The environmental costs, directly or indirectly generated to achieve such a challenging objective, remain however largely underexplored. Until now, research has focused either on pure economic approaches such as Computable General Equilibrium (CGE) and partial equilibrium (PE) models, or on (physical) energy supply scenarios. These latter could be used to evaluate the environmental impacts of various energy saving or cleaner technologies via Life Cycle Assessment (LCA) methodology. These modelling efforts have, however, been pursued in isolation, without exploring the possible complementarities and synergies. In this study, we have undertaken a practical combination of these approaches into a common framework: on the one hand, by coupling a CGE with a PE model, and, on the other hand, by linking the outcomes from the coupling with a hybrid input–output−process based life cycle inventory. The methodological framework aimed at assessing the environmental consequences of two energy policy scenarios in Luxembourg between 2010 and 2025. The study highlights the potential of coupling CGE and PE models but also the related methodological difficulties (e.g. small number of available technologies in Luxembourg, intrinsic limitations of the two approaches, etc.). The assessment shows both environmental synergies and trade-offs due to the implementation of

  9. Thermodynamic analysis of an integrated solid oxide fuel cell cycle with a rankine cycle

    International Nuclear Information System (INIS)

    Rokni, Masoud

    2010-01-01

    Hybrid systems consisting of solid oxide fuel cells (SOFC) on the top of a steam turbine (ST) are investigated. The plants are fired by natural gas (NG). A desulfurization reactor removes the sulfur content in the fuel while a pre-reformer breaks down the heavier hydro-carbons. The pre-treated fuel enters then into the anode side of the SOFC. The remaining fuels after the SOFC stacks enter a burner for further burning. The off-gases are then used to produce steam for a Rankine cycle in a heat recovery steam generator (HRSG). Different system setups are suggested. Cyclic efficiencies up to 67% are achieved which is considerably higher than the conventional combined cycles (CC). Both adiabatic steam reformer (ASR) and catalytic partial oxidation (CPO) fuel pre-reformer reactors are considered in this investigation.

  10. A life-cycle approach to technology, infrastructure, and climate policy decision making: Transitioning to plug-in hybrid electric vehicles and low-carbon electricity

    Science.gov (United States)

    Samaras, Constantine

    In order to mitigate the most severe effects of climate change, large global reductions in the current levels of anthropogenic greenhouse gas (GHG) emissions are required in this century to stabilize atmospheric carbon dioxide (CO2) concentrations at less than double pre-industrial levels. The Intergovernmental Panel on Climate Change (IPCC) fourth assessment report states that GHG emissions should be reduced to 50-80% of 2000 levels by 2050 to increase the likelihood of stabilizing atmospheric CO2 concentrations. In order to achieve the large GHG reductions by 2050 recommended by the IPCC, a fundamental shift and evolution will be required in the energy system. Because the electric power and transportation sectors represent the largest GHG emissions sources in the United States, a unique opportunity for coupling these systems via electrified transportation could achieve synergistic environmental (GHG emissions reductions) and energy security (petroleum displacement) benefits. Plug-in hybrid electric vehicles (PHEVs), which use electricity from the grid to power a portion of travel, could play a major role in reducing greenhouse gas emissions from the transport sector. However, this thesis finds that life cycle GHG emissions from PHEVs depend on the electricity source that is used to charge the battery, so meaningful GHG emissions reductions with PHEVs are conditional on low-carbon electricity sources. Power plants and their associated GHGs are long-lived, and this work argues that decisions made regarding new electricity supplies within the next ten years will affect the potential of PHEVs to play a role in a low-carbon future in the coming decades. This thesis investigates the life cycle engineering, economic, and policy decisions involved in transitioning to PHEVs and low-carbon electricity. The government has a vast array of policy options to promote low-carbon technologies, some of which have proven to be more successful than others. This thesis uses life

  11. Mitigation of climate change via a copper-chlorine hybrid thermochemical water splitting cycle for hydrogen production from nuclear energy

    International Nuclear Information System (INIS)

    Orhan, M.F.; Dincer, I.; Rosen, M.A.

    2009-01-01

    Concerns regarding climate change have motivated research on clean energy resources. While many energy resources have limitations, nuclear energy has the potential to supply a significant share of energy supply without contributing to climate change. Nuclear energy has been used mainly for electric power generation, but hydrogen production via thermochemical water decomposition provides another option for the utilization of nuclear thermal energy. This paper describes nuclear-based hydrogen production technologies and discusses the role of the Cu-Cl cycle for thermochemical water decomposition, potentially driven in part by waste heat from a nuclear generating station, in reducing greenhouse gas emissions. (author)

  12. Exergy and economic analysis of organic rankine cycle hybrid system utilizing biogas and solar energy in rural area of China

    DEFF Research Database (Denmark)

    Zhao, Chunhua; Zheng, Siyu; Zhang, Ji

    2017-01-01

    circuits. The cogeneration supplied the power to the air-condition in summer condition and hot water, which is heated in the condenser, in winter condition. The system performance under the subcritical pressures has been assessed according to the energy-exergy and economic analysis with the organic working......℃. The exergy efficiency of organic Rankine cycle (ORC) system increases from 35.2% to 38.2%. Moreover, an economic analysis of the system is carried out. The results demonstrate that the profits generated from the reduction of biogas fuel and electricity consumption can lead to a significant saving, resulting...

  13. A Hybrid Life-Cycle Assessment of Nonrenewable Energy and Greenhouse-Gas Emissions of a Village-Level Biomass Gasification Project in China

    Directory of Open Access Journals (Sweden)

    Mingyue Pang

    2012-07-01

    Full Text Available Small-scale bio-energy projects have been launched in rural areas of China and are considered as alternatives to fossil-fuel energy. However, energetic and environmental evaluation of these projects has rarely been carried out, though it is necessary for their long-term development. A village-level biomass gasification project provides an example. A hybrid life-cycle assessment (LCA of its total nonrenewable energy (NE cost and associated greenhouse gas (GHG emissions is presented in this paper. The results show that the total energy cost for one joule of biomass gas output from the project is 2.93 J, of which 0.89 J is from nonrenewable energy, and the related GHG emission cost is 1.17 × 10−4 g CO2-eq over its designed life cycle of 20 years. To provide equivalent effective calorific value for cooking work, the utilization of one joule of biomass gas will lead to more life cycle NE cost by 0.07 J and more GHG emissions by 8.92 × 10−5 g CO2-eq compared to natural gas taking into consideration of the difference in combustion efficiency and calorific value. The small-scale bio-energy project has fallen into dilemma, i.e., struggling for survival, and for a more successful future development of village-level gasification projects, much effort is needed to tide over the plight of its development, such as high cost and low efficiency caused by decentralized construction, technical shortcomings and low utilization rate of by-products.

  14. Sulfur bacteria in wastewater stabilization ponds periodically affected by the ‘red-water’ phenomenon

    NARCIS (Netherlands)

    Belila, A.; Abbas, B.; Fazaa, I.; Saidi, N.; Snoussi, M.; Hassen, A.; Muyzer, G.

    2012-01-01

    Several wastewater stabilization ponds (WSP) in Tunisia suffer periodically from the ‘red-water’ phenomenon due to blooming of purple sulfur bacteria, indicating that sulfur cycle is one of the main element cycles in these ponds. In this study, we investigated the microbial diversity of the El

  15. Sulfur bacteria in wastewater stabilization ponds periodically affected by the 'red-water' phenomenon

    NARCIS (Netherlands)

    Belila, A.; Abbas, B.; Fazaa, I.; Saidi, N.; Snoussi, M.; Hassen, A.; Muyzer, G.

    2013-01-01

    Several wastewater stabilization ponds (WSP) in Tunisia suffer periodically from the ‘red-water’ phenomenon due to blooming of purple sulfur bacteria, indicating that sulfur cycle is one of the main element cycles in these ponds. In this study, we investigated the microbial diversity of the El

  16. Is overprotection of the sulfur cathode good for Li-S batteries?

    Science.gov (United States)

    Gao, Tian; Shao, Jie; Li, Xingxing; Zhu, Guobin; Lu, Qiujian; Han, Yuyao; Qu, Qunting; Zheng, Honghe

    2015-08-11

    How to restrain the dissolution of polysulfides from the sulfur cathode is the current research focus of Li-S batteries. Here, we find that moderate dissolution of polysulfides is of great importance for high-efficiency and stable discharge/charge cycling. Both overprotection and inadequate protection of the sulfur cathode are unfavorable for the cycling of Li-S batteries.

  17. Decoupling of Neoarchean sulfur sources recorded in Algoma-type banded iron formation

    Science.gov (United States)

    Diekrup, David; Hannington, Mark D.; Strauss, Harald; Ginley, Stephen J.

    2018-05-01

    Neoarchean Algoma-type banded iron formations (BIFs) are widely viewed as direct chemical precipitates from proximal volcanic-hydrothermal vents. However, a systematic multiple sulfur isotope study of oxide-facies BIF from a type locality in the ca. 2.74 Ga Temagami greenstone belt reveals mainly bacterial turnover of atmospheric elemental sulfur in the host basin rather than deposition of hydrothermally cycled seawater sulfate or sulfur from direct volcanic input. Trace amounts of chromium reducible sulfur that were extracted for quadruple sulfur isotope (32S-33S-34S-36S) analysis record the previously known mass-independent fractionation of volcanic SO2 in the Archean atmosphere (S-MIF) and biological sulfur cycling but only minor contributions from juvenile sulfur, despite the proximity of volcanic sources. We show that the dominant bacterial metabolisms were iron reduction and sulfur disproportionation, and not sulfate reduction, consistent with limited availability of organic matter and the abundant ferric iron deposited as Fe(OH)3. That sulfur contained in the BIF was not a direct volcanic-hydrothermal input, as expected, changes the view of an important archive of the Neoarchean sulfur cycle in which the available sulfur pools were strongly decoupled and only species produced photochemically under anoxic atmospheric conditions were deposited in the BIF-forming environment.

  18. 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.

  19. Responses of Forest Ecosystems to Changing Sulfur Inputs

    Science.gov (United States)

    Dale W. Johnson; Myron J. Mitchell

    1998-01-01

    There was little information on sulfur (S) cycling in forests compared with that of other nutrients (especially N) until the past two decades. Interest in S nutrition and cycling in forests was heightened with the discovery of deficiencies in some unpolluted regions (Kelly and Lambert, 1972; Humphreys et al., 1975; Turner et al., 1977, 1980) and excesses associated...

  20. 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.

  1. Impact of Different Driving Cycles and Operating Conditions on CO2 Emissions and Energy Management Strategies of a Euro-6 Hybrid Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Claudio Cubito

    2017-10-01

    Full Text Available Although Hybrid Electric Vehicles (HEVs represent one of the key technologies to reduce CO2 emissions, their effective potential in real world driving conditions strongly depends on the performance of their Energy Management System (EMS and on its capability to maximize the efficiency of the powertrain in real life as well as during Type Approval (TA tests. Attempting to close the gap between TA and real world CO2 emissions, the European Commission has decided to introduce from September 2017 the Worldwide Harmonized Light duty Test Procedure (WLTP, replacing the previous procedure based on the New European Driving Cycle (NEDC. The aim of this work is the analysis of the impact of different driving cycles and operating conditions on CO2 emissions and on energy management strategies of a Euro-6 HEV through the limited number of information available from the chassis dyno tests. The vehicle was tested considering different initial battery State of Charge (SOC, ranging from 40% to 65%, and engine coolant temperatures, from −7 °C to 70 °C. The change of test conditions from NEDC to WLTP was shown to lead to a significant reduction of the electric drive and to about a 30% increase of CO2 emissions. However, since the specific energy demand of WLTP is about 50% higher than that of NEDC, these results demonstrate that the EMS strategies of the tested vehicle can achieve, in test conditions closer to real life, even higher efficiency levels than those that are currently evaluated on the NEDC, and prove the effectiveness of HEV technology to reduce CO2 emissions.

  2. Micro-Spherical Sulfur/Graphene Oxide Composite via Spray Drying for High Performance Lithium Sulfur Batteries

    Science.gov (United States)

    Tian, Yuan; Sun, Zhenghao; Zhang, Yongguang; Yin, Fuxing

    2018-01-01

    An efficient, industry-accepted spray drying method was used to synthesize micro-spherical sulfur/graphene oxide (S/GO) composites as cathode materials within lithium sulfur batteries. The as-designed wrapping of the sulfur-nanoparticles, with wrinkled GO composites, was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The unique morphological design of this material enabled superior discharge capacity and cycling performance, demonstrating a high initial discharge capacity of 1400 mAh g−1 at 0.1 C. The discharge capacity remained at 828 mAh g−1 after 150 cycles. The superior electrochemical performance indicates that the S/GO composite improves electrical conductivity and alleviates the shuttle effect. This study represents the first time such a facile spray drying method has been adopted for lithium sulfur batteries and used in the fabrication of S/GO composites. PMID:29346303

  3. 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.

  4. 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.

  5. 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.

  6. 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.)

  7. Application of a Hybrid Forest Growth Model to Evaluate Climate Change Impacts on Productivity, Nutrient Cycling and Mortality in a Montane Forest Ecosystem.

    Directory of Open Access Journals (Sweden)

    Brad Seely

    Full Text Available Climate change introduces considerable uncertainty in forest management planning and outcomes, potentially undermining efforts at achieving sustainable practices. Here, we describe the development and application of the FORECAST Climate model. Constructed using a hybrid simulation approach, the model includes an explicit representation of the effect of temperature and moisture availability on tree growth and survival, litter decomposition, and nutrient cycling. The model also includes a representation of the impact of increasing atmospheric CO2 on water use efficiency, but no direct CO2 fertilization effect. FORECAST Climate was evaluated for its ability to reproduce the effects of historical climate on Douglas-fir and lodgepole pine growth in a montane forest in southern British Columbia, Canada, as measured using tree ring analysis. The model was subsequently used to project the long-term impacts of alternative future climate change scenarios on forest productivity in young and established stands. There was a close association between predicted sapwood production and measured tree ring chronologies, providing confidence that model is able to predict the relative impact of annual climate variability on tree productivity. Simulations of future climate change suggest a modest increase in productivity in young stands of both species related to an increase in growing season length. In contrast, results showed a negative impact on stemwood biomass production (particularly in the case of lodgepole pine for established stands due to increased moisture stress mortality.

  8. Application of a Hybrid Forest Growth Model to Evaluate Climate Change Impacts on Productivity, Nutrient Cycling and Mortality in a Montane Forest Ecosystem.

    Science.gov (United States)

    Seely, Brad; Welham, Clive; Scoullar, Kim

    2015-01-01

    Climate change introduces considerable uncertainty in forest management planning and outcomes, potentially undermining efforts at achieving sustainable practices. Here, we describe the development and application of the FORECAST Climate model. Constructed using a hybrid simulation approach, the model includes an explicit representation of the effect of temperature and moisture availability on tree growth and survival, litter decomposition, and nutrient cycling. The model also includes a representation of the impact of increasing atmospheric CO2 on water use efficiency, but no direct CO2 fertilization effect. FORECAST Climate was evaluated for its ability to reproduce the effects of historical climate on Douglas-fir and lodgepole pine growth in a montane forest in southern British Columbia, Canada, as measured using tree ring analysis. The model was subsequently used to project the long-term impacts of alternative future climate change scenarios on forest productivity in young and established stands. There was a close association between predicted sapwood production and measured tree ring chronologies, providing confidence that model is able to predict the relative impact of annual climate variability on tree productivity. Simulations of future climate change suggest a modest increase in productivity in young stands of both species related to an increase in growing season length. In contrast, results showed a negative impact on stemwood biomass production (particularly in the case of lodgepole pine) for established stands due to increased moisture stress mortality.

  9. 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.

  10. 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

  11. 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.

  12. Sulfur cathode integrated with multileveled carbon nanoflake-nanosphere networks for high-performance lithium-sulfur batteries

    International Nuclear Information System (INIS)

    Li, S.H.; Wang, X.H.; Xia, X.H.; Wang, Y.D.; Wang, X.L.; Tu, J.P.

    2017-01-01

    Tailored design/construction of high-quality sulfur/carbon composite cathode is critical for development of advanced lithium-sulfur batteries. We report a powerful strategy for integrated fabrication of sulfur impregnated into three-dimensional (3D) multileveled carbon nanoflake-nanosphere networks (CNNNs) by means of sacrificial ZnO template plus glucose carbonization. The multileveled CNNNs are not only utilized as large-area host/backbone for sulfur forming an integrated S/CNNNs composite electrode, but also serve as multiple carbon blocking barriers (nanoflake infrastructure andnanosphere superstructure) to physically confine polysulfides at the cathode. The designedself-supported S/CNNNs composite cathodes exhibit superior electrochemical performances with high capacities (1395 mAh g −1 at 0.1C, and 769 mAh g −1 at 5.0C after 200 cycles) and noticeable cycling performance (81.6% retention after 200 cycles). Our results build a new bridge between sulfur and carbon networks with multiple blocking effects for polysulfides, and provide references for construction of other high-performance sulfur cathodes.

  13. 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.

  14. 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.

  15. Effects of hybrid cycling versus handcycling on wheelchair-specific fitness and physical activity in people with long-term spinal cord injury: a 16-week randomized controlled trial.

    Science.gov (United States)

    Bakkum, A J T; de Groot, S; Stolwijk-Swüste, J M; van Kuppevelt, D J; van der Woude, L H V; Janssen, T W J

    2015-05-01

    This is an open randomized controlled trial. The objective of this study was to investigate the effects of a 16-week hybrid cycle versus handcycle exercise program on fitness and physical activity in inactive people with long-term spinal cord injury (SCI). The study was conducted in two rehabilitation centers with a specialized SCI unit. Twenty individuals (SCI⩾8 years) were randomly assigned to a hybrid cycle (voluntary arm exercise combined with functional electrical stimulation (FES)-induced leg exercise) or a handcycle group. During 16 weeks, both groups trained twice a week for 30 min at 65-75% heart rate reserve. Outcome measures obtained before, during and after the program were fitness (peak power output, peak oxygen consumption), submaximal VO2 and heart rate (HR), resting HR, wheelchair skill performance time score) and physical activity (distance travelled in wheelchair and Physical Activity Scale for Individuals with Physical Disabilities (PASIPD) score). Changes were examined using a two-factor mixed-measures analysis of variance. For all fitness parameters, except for submaximal VO2, no interaction effects were found. The hybrid cycle group showed a decrease in VO2 over time in contrast to the handcycle group (P=0.045). An overall reduction in HRrest (5±2 b.p.m.; P=0.03) and overall increase in PASIPD score (6.5±2.1; P=0.002) were found after 16 weeks of training. No overall training effects were found for the other fitness and activity outcome measures. In the current study, hybrid cycling and handcycling showed similar effects on fitness and physical activity, indicating that there seem to be no additional benefits of the FES-induced leg exercise over handcycle training alone.

  16. 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.

  17. 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.

  18. 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.

  19. 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...

  20. [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

  1. 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

  2. A novel hybrid catalyst for the esterification of high FFA in Jatropha oil for biodiesel production

    International Nuclear Information System (INIS)

    Mushtaq, M.; Tan, I.M.; Sagir, M.; Suleman Tahir, M.; Pervaiz, M.

    2016-01-01

    The synthesis and application of a hybrid catalyst for the esterification of free fatty acids (FFA) in Jatropha oil is reported. Three catalysts, namely silica sulfuric acid, silica supported boron trifluoride and a combination of the two in the weight ratio of 1:1, the hybrid catalyst, were investigated. Jatropha oil samples with a wide range of FFA values i.e. 6.64 to 45.64% were prepared and utilized for the experimental work. This study revealed that silica sulfuric acid and silica supported boron trifluoride were not very effective when used independently. However, a strong synergistic effect was noted in the catalytic activity of the hybrid catalyst which reduced the FFA value from 45.64 to 0.903% with a conversion efficiency of 98%. Reusability of the catalyst was also tested and the results were promising in up to three cycles of use when used with lower amounts of FFA (6.64%) in the oil. Under the influence of the catalyst, the reaction was found to follow first order kinetics. Activation energy was calculated to be 45.42 KJ·mol−1 for 2 wt.% of hybrid catalyst. The products were analyzed by FT-IR and NMR spectroscopic techniques and the results are reported. [es

  3. Directly Formed Alucone on Lithium Metal for High-Performance Li Batteries and Li-S Batteries with High Sulfur Mass Loading.

    Science.gov (United States)

    Chen, Lin; Huang, Zhennan; Shahbazian-Yassar, Reza; Libera, Joseph A; Klavetter, Kyle C; Zavadil, Kevin R; Elam, Jeffrey W

    2018-02-28

    Lithium metal is considered the "holy grail" of next-generation battery anodes. However, severe parasitic reactions at the lithium-electrolyte interface deplete the liquid electrolyte and the uncontrolled formation of high surface area and dendritic lithium during cycling causes rapid capacity fading and battery failure. Engineering a dendrite-free lithium metal anode is therefore critical for the development of long-life batteries using lithium anodes. In this study, we deposit a conformal, organic/inorganic hybrid coating, for the first time, directly on lithium metal using molecular layer deposition (MLD) to alleviate these problems. This hybrid organic/inorganic film with high cross-linking structure can stabilize lithium against dendrite growth and minimize side reactions, as indicated by scanning electron microscopy. We discovered that the alucone coating yielded several times longer cycle life at high current rates compared to the uncoated lithium and achieved a steady Coulombic efficiency of 99.5%, demonstrating that the highly cross-linking structured material with great mechanical properties and good flexibility can effectively suppress dendrite formation. The protected Li was further evaluated in lithium-sulfur (Li-S) batteries with a high sulfur mass loading of ∼5 mg/cm 2 . After 140 cycles at a high current rate of ∼1 mA/cm 2 , alucone-coated Li-S batteries delivered a capacity of 657.7 mAh/g, 39.5% better than that of a bare lithium-sulfur battery. These findings suggest that flexible coating with high cross-linking structure by MLD is effective to enable lithium protection and offers a very promising avenue for improved performance in the real applications of Li-S batteries.

  4. 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

  5. Nitrogen and Sulfur Co-doped Graphene Supported Cobalt Sulfide Nanoparticles as an Efficient Air Cathode for Zinc-air Battery

    International Nuclear Information System (INIS)

    Ganesan, Pandian; Ramakrishnan, Prakash; Prabu, Moni; Shanmugam, Sangaraju

    2015-01-01

    Highlights: • CoS 2 nanoparticles supported on a nitrogen and sulfur co-doped graphene oxide is described. • Improved round trip efficiency was observed for CoS 2 (400)/N,S-GO. • CoS 2 (400)/N,S-GO possess improved durability with low over-potential. • CoS 2 (400)/N,S-GO is a promising air cathode for zinc-air battery. - ABSTRACT: Zinc-air battery is considered as one of the promising energy storage devices due to their low cost, eco-friendly and safe. Here, we present a simple approach to the preparation of cobalt sulfide nanoparticles supported on a nitrogen and sulfur co-doped graphene oxide surface. Cobalt sulfide nanoparticles dispersed on graphene oxide hybrid was successfully prepared by solid state thermolysis approach at 400 °C, using cobalt thiourea and graphene oxide. X-ray diffraction study revealed that hybrid electrode prepared at 400 °C results in pure CoS 2 phase. The hybrid CoS 2 (400)/N,S-GO electrode exhibits low over-potential gap about 0.78 V vs. Zn after 70 cycles with remarkable and robust charge and discharge profile. And also the CoS 2 (400)/N,S-GO showing deep discharge behavior with stability up to 7.5 h.

  6. Hybrid combined cycle power plant

    International Nuclear Information System (INIS)

    Veszely, K.

    2002-01-01

    In case of re-powering the existing pressurised water nuclear power plants by the proposed HCCPP solution, we can increase the electricity output and efficiency significantly. If we convert a traditional nuclear power plant unit to a HCCPP solution, we can achieve a 3.2-5.5 times increase in electricity output and the achievable gross efficiency falls between 46.8-52% and above, depending on the applied solution. These figures emphasise that we should rethink our power plant technologies and we have to explore a great variety of HCCPP solutions. This may give a new direction in the development of nuclear reactors and power plants as well.(author)

  7. 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.

  8. 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.

  9. A binder-free sulfur/reduced graphene oxide aerogel as high performance electrode materials for lithium sulfur batteries

    Science.gov (United States)

    Nitze, Florian; Agostini, Marco; Lundin, Filippa; Palmqvist, Anders E. C.; Matic, Aleksandar

    2016-12-01

    Societies’ increasing need for energy storage makes it necessary to explore new concepts beyond the traditional lithium ion battery. A promising candidate is the lithium-sulfur technology with the potential to increase the energy density of the battery by a factor of 3-5. However, so far the many problems with the lithium-sulfur system have not been solved satisfactory. Here we report on a new approach utilizing a self-standing reduced graphene oxide based aerogel directly as electrodes, i.e. without further processing and without the addition of binder or conducting agents. We can thereby disrupt the common paradigm of “no battery without binder” and can pave the way to a lithium-sulfur battery with a high practical energy density. The aerogels are synthesized via a one-pot method and consist of more than 2/3 sulfur, contained inside a porous few-layered reduced graphene oxide matrix. By combining the graphene-based aerogel cathode with an electrolyte and a lithium metal anode, we demonstrate a lithium-sulfur cell with high areal capacity (more than 3 mAh/cm2 after 75 cycles), excellent capacity retention over 200 cycles and good sulfur utilization. Based on this performance we estimate that the energy density of this concept-cell can significantly exceed the Department of Energy (DEO) 2020-target set for transport applications.

  10. Photonics at the frontiers. Generation of few-cycle light pulses via NOPCPA and real-time probing of charge transfer in hybrid photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Herrmann, Daniel

    2011-11-11

    In the first part of this thesis the methodics of the non-collinear, optically parametric amplification of chirped light pulses (NOPCPA) for the generation of few-cycle light pulses in the visible (Vis) and near infrared (NIR) with of 5-8 fs half-width are essential further developed. Fundamental parametric influences, like the existence of a parametrically induced phase and the generation of optically parametric fluorescence (OPF), are studied both by theoretical analyses and numerical simulations and by concrete experiments. Experimentally in the framework of this thesis fwe-cycle light pulses with a pulse width of 7.9 fs, 130 mJ energy, at 805 nm central wavelength and a very high seed-pulse-limited prepulse contrast of 11 and 8 orders of magnitude are reached at 30 ps and approximately 3 ps. One the one hand it has been succeeded to accelerate with the broad-band pulse amplifier quasi-monoenergetic electrons with energies of up to 50 MeV. For this the light pulse is focussed to relativistic intensities of several W/cm{sup 2} in a helium gas jet. On the other hand XUV light was produced up to the 20th harmonic of the generated light pulse from the broad-band pulse amplifier by its sub-cycle interaction with solid surfaces. In the framework of this thesis furthermore new, extended concepts for still broader-band NOPCPA over one octave were developed and characterized, which contain the application of two pump pulses in one NOPCPA stage and the application of two different pump wavelength in two subsequent NOPCPA stages. In the second part of this thesis broad-band white-light spectra and by means of NOPCPA spectrally tunable light pulses are applied in order to realize a transient absorption spectrometer with multichannel detection. This new excitation-query construction combines a very broad-band UV-Vis-NIR query with a high time resolution of 40 fs and high sensitivity for the transient change of the optical density of less than 10{sup -4}. By this it has in

  11. 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.

  12. 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...

  13. 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.

  14. Levels of Sulfur as an Essential Nutrient Element in the Soil-Crop-Food System in Austria

    Directory of Open Access Journals (Sweden)

    Manfred Sager

    2012-01-01

    Full Text Available Total sulfur data of various agricultural and food items from the lab of the author, have been compiled to develop an understanding of sulfur levels and ecological cycling in Austria. As sulfur level is not an included factor among the quality criteria of soil and fertilizer composition, the database is rather small. Problems in analytical determinations of total sulfur, in particular digestions, are outlined. As a protein component, sulfur is enriched in matrices of animal origin, in particular in egg white. There is substantial excretion from animals and man via urine. Organic fertilizers (manures, composts might contribute significantly to the sulfur budget of soils, which is important for organic farming of crops with high sulfur needs. For soils, drainage is a main route of loss of soluble sulfate, thus pot experiments may yield unrealistic sulfur budgets.

  15. Hybrid wind–photovoltaic–diesel–battery system sizing tool development using empirical approach, life-cycle cost and performance analysis: A case study in Scotland

    International Nuclear Information System (INIS)

    Gan, Leong Kit; Shek, Jonathan K.H.; Mueller, Markus A.

    2015-01-01

    Highlights: • Methods of sizing a hybrid wind–photovoltaic–diesel–battery system is described. • The hybrid system components are modelled using empirical data. • Twenty years lifecycle cost of the hybrid system is considered. • The trade-offs between battery storage capacity and diesel fuel usage is studied. • A hybrid system sizing tool has been developed as a graphical user interface (GUI). - Abstract: The concept of off-grid hybrid wind energy system is financially attractive and more reliable than stand-alone power systems since it is based on more than one electricity generation source. One of the most expensive components in a stand-alone wind-power system is the energy storage system as very often it is oversized to increase system autonomy. In this work, we consider a hybrid system which consists of wind turbines, photovoltaic panels, diesel generator and battery storage. One of the main challenges experienced by project managers is the sizing of components for different sites. This challenge is due to the variability of the renewable energy resource and the load demand for different sites. This paper introduces a sizing model that has been developed and implemented as a graphical user interface, which predicts the optimum configuration of a hybrid system. In particular, this paper focuses on seeking the optimal size of the batteries and the diesel generator usage. Both of these components are seen to be trade-offs from each other. The model simulates real time operation of the hybrid system, using the annual measured hourly wind speed and solar irradiation. The benefit of using time series approach is that it reflects a more realistic situation; here, the peaks and troughs of the renewable energy resource are a central part of the sizing model. Finally, load sensitivity and hybrid system performance analysis are demonstrated.

  16. 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.

  17. Preparation and enhanced electrochemical properties of nano-sulfur/poly(pyrrole-co-aniline) cathode material for lithium/sulfur batteries

    International Nuclear Information System (INIS)

    Qiu Linlin; Zhang Shichao; Zhang Lan; Sun, Mingming; Wang Weikun

    2010-01-01

    Poly(pyrrole-co-aniline) (PPyA) copolymer nanofibers were prepared by chemical oxidation method with cetyltrimethyl ammonium chloride (CTAC) as template, and the nano-sulfur/poly(pyrrole-co-aniline) (S/PPyA) composite material in lithium batteries was achieved via co-heating the mixture of PPyA and sublimed sulfur at 160 deg. C for 24 h. The component and structure of the materials were characterized by FTIR, Raman, XRD, and SEM. PPyA with nanofiber network structure was employed as a conductive matrix, adsorbing agent and firm reaction chamber for the sulfur cathode materials. The nano-dispersed composite exhibited a specific capacity up to 1285 mAh g -1 in the initial cycle and remained 866 mAh g -1 after 40 cycles.

  18. A Li+-conductive microporous carbon–sulfur composite for Li-S batteries

    International Nuclear Information System (INIS)

    Zhang, Wenhua; Qiao, Dan; Pan, Jiaxin; Cao, Yuliang; Yang, Hanxi; Ai, Xinping

    2013-01-01

    Highlights: ► A carbon–sulfur composite was prepared by vaporizing sulfur into the nanopores of Li + -conductive carbon microspheres. ► The redox reaction of S 8 molecules embedded in the nanopores of carbon microspheres proceeds through a solid–solid mechanism at the S/C interfaces. ► The carbon–sulfur composite exhibits a stable cycling performance and a superior high coulombic efficiency of 100%. - Abstract: In this paper, we propose a new strategy to develop high performance sulfur electrode by impregnating sulfur into the micropores of a Li + -insertable carbon matrix with the simultaneous use of a carbonate electrolyte, which does not dissolve polysulfides, to restrain the solution of the reaction intermediates of sulfur. To proof this concept, we prepared a Li + -insertable microporous carbon–sulfur composite by vaporizing sulfur into the micropores of the nanofiber-wired carbon microspheres. The experimental results demonstrate that, in the carbonate electrolyte of 1 M LiPF 6 /PC-EC-DEC, such S/C composite electrode exhibits not only stable cycling performance with a reversible capacity of 720 mAh g −1 after 100 cycles, but also superior high coulombic efficiency of ∼100% upon extended cycling (except the first three cycles). The structural and electrochemical analysis indicates that the improved electrochemical behaviors of the S/C composite arise from a new reaction mechanism, in which Li + ions and electrons transport through the carbon matrix into the interior of the cathode and then react with the embedded sulfur in the S/C solid–solid interfaces, avoiding the solution of the intermediates into the bulk electrolyte. More significantly, the structural design and working mechanism of such a sulfur cathode could be extended to a variety of poorly conductive and easily soluble redox-active materials for battery applications.

  19. Achievement report on research and development in the Sunshine Project in fiscal 1976. Research and development of water decomposition by using a hybrid cycle composed of thermo-chemistry and photo-chemistry; 1976 nendo netsukagaku oyobi hikari kagaku hybrid cycle ni yoru mizu bunkai no kenkyu kahatsu seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1977-03-01

    This paper describes water decomposition by using a hybrid cycle composed of thermo-chemistry and photo-chemistry. Ferric sulfate and HI are obtained from ferrous sulfate and iodine via photo-chemical reaction. This is an endothermic reaction of 10.8 kcal. Then, the photo-chemically reacted aqueous solution is electrolysed to separate HI, while Fe{sup 3+} (ferric ion) is reduced and converted into Fe{sup 2+} (ferrous ion). Oxygen is generated at this time. Since mixed potential is made from iron oxidation and reduction potential and iodine potential, the electrolytic efficiency is greatly influenced by electrode materials. Ideally, an electrode material that causes only the reduction of Fe{sup 3+}, but not other reactions is preferable. The HI is decomposed into hydrogen and iodine by electrolysis. Research is continuing to acquire hydrogen from HI thermo-chemically. Endothermic reaction heat of 7 to 8 kcal has been obtained in photo-chemical reaction, the heat quantity being close to the theoretical value of 10.8. A result close to the theoretical value may be expected if the electrode material problem is solved. The basic research will be continued for a high possibility of linking the research to a pilot plant in the future. (NEDO)

  20. Oxidation of phosphine by sulfur or selenium involving a catalytic ...

    Indian Academy of Sciences (India)

    Administrator

    P NMR spec- troscopy. Such interconversion with the participation of breaking of bridging copper-µ3-sulfur bond with the formation of new copper–phosphorous bond led to the development of a catalytic cycle using excess. PPh3 and S or Se as the reacting substrates. The turnover number for the oxidation of PPh3 by S ...

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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...

  6. Hybrid Electric Vehicle Testing | Transportation Research | NREL

    Science.gov (United States)

    Hybrid Electric Vehicle Evaluations Hybrid Electric Vehicle Evaluations How Hybrid Electric Vehicles Work Hybrid electric vehicles combine a primary power source, an energy storage system, and an is used to propel the vehicle during normal drive cycles. The batteries supply additional power for

  7. The impact of freeze-thawing on the friability of formed elemental sulfur

    Energy Technology Data Exchange (ETDEWEB)

    Clark, P.D.; Almond, P.

    1995-10-01

    Winter weather fluctuation tests were performed in a laboratory to determine the freeze-thaw effect on the particle size distribution and friability of sulfur samples of Polish Air Prills, Procor GX Granules, Petrosul, Sandvik Rotoform, and slate. Formed elemental sulfur is often stored outdoors and is subjected to temperature fluctuations which could potentially result in structural stress, particularly if the sulfur contained any moisture from rainwater or melting snow. Concern was expressed that sulfur stored under these conditions might have increased friability during shipping and handling. Results of stress level tests indicated that winter weather fluctuations did not effect the particle size distribution or friability of the samples. When sulfur samples were in contact with water for one month, there were was no significant change in overall friability. It was concluded that all premium product forms of solid elemental sulfur could be stored outdoors, even if subjected to freeze-thaw cycles. 4 tabs., 5 figs.

  8. Experimental Evidence for Abiotic Sulfurization of Marine Dissolved Organic Matter

    Directory of Open Access Journals (Sweden)

    Anika M. Pohlabeln

    2017-11-01

    Full Text Available Dissolved organic sulfur (DOS is the largest pool of organic sulfur in the oceans, and as such it is an important component of the global sulfur cycle. DOS in the ocean is resistant against microbial degradation and turns over on a millennium time scale. However, sources and mechanisms behind its stability are largely unknown. Here, we hypothesize that in sulfate-reducing sediments sulfur is abiotically incorporated into dissolved organic matter (DOM and released to the ocean. We exposed natural seawater and the filtrate of a plankton culture to sulfidic conditions. Already after 1-h at 20°C, DOS concentrations had increased 4-fold in these experiments, and 14-fold after 4 weeks at 50°C, indicating that organic matter does not need long residence times in natural sulfidic environments to be affected by sulfurization. Molecular analysis via ultrahigh-resolution mass spectrometry showed that sulfur was covalently and unselectively bound to DOM. Experimentally produced and natural DOS from sediments were highly similar on a molecular and structural level. By combining our data with published benthic DOC fluxes we estimate that 30–200 Tg DOS are annually transported from anaerobic and sulfate reducing sediments to the oceans. Uncertainties in this first speculative assessment are large. However, this first attempt illustrates that benthic DOS flux is potentially one order of magnitude larger than that via rivers indicating that this could balance the estimated global net removal of refractory DOS.

  9. Disproportionation of elemental sulfur by haloalkaliphilic bacteria from soda lakes.

    Science.gov (United States)

    Poser, Alexander; Lohmayer, Regina; Vogt, Carsten; Knoeller, Kay; Planer-Friedrich, Britta; Sorokin, Dimitry; Richnow, Hans-H; Finster, Kai

    2013-11-01

    Microbial disproportionation of elemental sulfur to sulfide and sulfate is a poorly characterized part of the anoxic sulfur cycle. So far, only a few bacterial strains have been described that can couple this reaction to cell growth. Continuous removal of the produced sulfide, for instance by oxidation and/or precipitation with metal ions such as iron, is essential to keep the reaction exergonic. Hitherto, the process has exclusively been reported for neutrophilic anaerobic bacteria. Here, we report for the first time disproportionation of elemental sulfur by three pure cultures of haloalkaliphilic bacteria isolated from soda lakes: the Deltaproteobacteria Desulfurivibrio alkaliphilus and Desulfurivibrio sp. AMeS2, and a member of the Clostridia, Dethiobacter alkaliphilus. All cultures grew in saline media at pH 10 by sulfur disproportionation in the absence of metals as sulfide scavengers. Our data indicate that polysulfides are the dominant sulfur species under highly alkaline conditions and that they might be disproportionated. Furthermore, we report the first organism (Dt. alkaliphilus) from the class Clostridia that is able to grow by sulfur disproportionation.

  10. 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.

  11. 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

  12. 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.

  13. 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

  14. Metallic and highly conducting two-dimensional atomic arrays of sulfur enabled by molybdenum disulfide nanotemplate

    Science.gov (United States)

    Zhu, Shuze; Geng, Xiumei; Han, Yang; Benamara, Mourad; Chen, Liao; Li, Jingxiao; Bilgin, Ismail; Zhu, Hongli

    2017-10-01

    Element sulfur in nature is an insulating solid. While it has been tested that one-dimensional sulfur chain is metallic and conducting, the investigation on two-dimensional sulfur remains elusive. We report that molybdenum disulfide layers are able to serve as the nanotemplate to facilitate the formation of two-dimensional sulfur. Density functional theory calculations suggest that confined in-between layers of molybdenum disulfide, sulfur atoms are able to form two-dimensional triangular arrays that are highly metallic. As a result, these arrays contribute to the high conductivity and metallic phase of the hybrid structures of molybdenum disulfide layers and two-dimensional sulfur arrays. The experimentally measured conductivity of such hybrid structures reaches up to 223 S/m. Multiple experimental results, including X-ray photoelectron spectroscopy (XPS), transition electron microscope (TEM), selected area electron diffraction (SAED), agree with the computational insights. Due to the excellent conductivity, the current density is linearly proportional to the scan rate until 30,000 mV s-1 without the attendance of conductive additives. Using such hybrid structures as electrode, the two-electrode supercapacitor cells yield a power density of 106 Wh kg-1 and energy density 47.5 Wh kg-1 in ionic liquid electrolytes. Our findings offer new insights into using two-dimensional materials and their Van der Waals heterostructures as nanotemplates to pattern foreign atoms for unprecedented material properties.

  15. 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.

  16. Distribución de nitrógeno, fósforo y azufre en un cultivo de colza: efectos sobre el ciclado de nutrientes Distribution of nitrogen, phosphorus and sulfur in oilseed rape: effects on nutrient cycling

    Directory of Open Access Journals (Sweden)

    Gerardo Rubio

    2007-12-01

    Full Text Available Comparado con otros cultivos, la colza tiene una alta demanda de azufre (S por lo que sería esperable que la inclusión de este cultivo en la rotación agrícola acelere el agotamiento de este nutriente en los suelos de las áreas cultivadas. En este trabajo, se comparan los patrones de partición de biomasa, S, nitrógeno (N y fósforo (P en plantas maduras de colza. La información a obtener es relevante desde el punto de vista del ciclado de nutrientes. Para ello se realizó un experimento de campo que se ajustó a un arreglo factorial con dos factores (N y S. En el momento de la cosecha, se midió la acumulación de biomasa, N, P y S en tres compartimientos: granos, rastrojo (resto de parte aérea y raíces. Aunque el rendimiento fue afectado levemente por la adición individual de N o S, la simultánea adición de ambos nutrientes provocó un incremento del 56%. El N y el P presentaron una distribución semejante entre los órganos de la planta estudiados, sin embargo, el S difirió marcadamente de ambos. Su partición al órgano que se exporta (granos fue de menor magnitud que la observada para N y P. En cambio, su partición al rastrojo en pie fue mayor. Esta característica atenuaría los efectos de la alta demanda de S sobre la exportación del cultivo y permitiría una reutilización del fertilizante agregado por el cultivo siguiente.Oilseed rape poses a higher sulfur (S demand, compared to other crops. This may indicate that the inclusion of this crop in the crop rotation could accelerate soil S depletion. In this work, we compared the allocation of biomass, nitrogen (N, phosphorus (P and S in oilseed rape mature plants. Two factors were analyzed in a field experiment: nitrogen and sulphur (two levels for each factor. At harvest, we measured the accumulation of biomass, N, P and S in three compartments: roots, straw and grains. Yield was little affected by the addition of single nutrients but the simultaneous addition of N and S

  17. Cycle killer... qu'est-ce que c'est? On the comparative approximability of hybridization number and directed feedback vertex set

    NARCIS (Netherlands)

    Kelk, S.M.; Iersel, van L.J.J.; Lekic, N.; Linz, S.; Scornavacca, C.; Stougie, L.

    2011-01-01

    We show that the problem of computing the hybridization number of two rooted binary phylogenetic trees on the same set of taxa X has a constant factor polynomial-time approximation if and only if the problem of computing a minimum-size feedback vertex set in a directed graph (DFVS) has a constant

  18. A flexible 3D nitrogen-doped carbon foam@CNTs hybrid hosting TiO2 nanoparticles as free-standing electrode for ultra-long cycling lithium-ion batteries

    Science.gov (United States)

    Yuan, Wei; Wang, Boya; Wu, Hao; Xiang, Mingwu; Wang, Qiong; Liu, Heng; Zhang, Yun; Liu, Huakun; Dou, Shixue

    2018-03-01

    Free-standing electrodes have stood out from the electrode pack, owing to their advantage of abandoning the conventional polymeric binder and conductive agent, thus increasing the specific capacity of lithium-ion batteries. Nevertheless, their practical application is hampered by inferior electrical conductivity and complex manufacturing process. To this end, we report here a facile approach to fabricate a flexible 3D N-doped carbon foam/carbon nanotubes (NCF@CNTs) hybrid to act as the current collector and host scaffold for TiO2 particles, which are integrated into a lightweight free-standing electrode (NCF@CNTs-TiO2). In the resulting architecture, ultra-fine TiO2 nanoparticles are homogeneously anchored in situ into the N-doped NCF@CNTs framework with macro- and meso-porous structure, wrapped by a dense CNT layer, cooperatively enhances the electrode flexibility and forms an interconnected conductive network for electron/ion transport. As a result, the as-prepared NCF@CNTs-TiO2 electrode exhibits excellent lithium storage performance with high specific capacity of 241 mAh g-1 at 1 C, superb rate capability of 145 mAh g-1 at 20 C, ultra-long cycling stability with an ultra-low capacity decay of 0.0037% per cycle over 2500 cycles, and excellent thermal stability with ∼94% capacity retention over 100 cycles at 55 °C.

  19. Sulfur impregnated in tunable porous N-doped carbon as sulfur cathode: effect of pore size distribution

    International Nuclear Information System (INIS)

    Wang, Sha; Zhao, Zhenxia; Xu, Hui; Deng, Yuanfu; Li, Zhong; Chen, Guohua

    2015-01-01

    Highlights: •Effects of pore size were investigated on electrochemistry for S cathode. •Activation energy of sulfur desorption from the PDA-C was estimated. •Strong interaction was formed between sulfur and porous N-doped carbon. •PDA-C@S showed good cycling performance of 608 mA h g −1 at 2 C over 300 cycles. •PDA-C@S showed good rate stability and high rate capacity. -- Abstract: A novel porous N-doped carbon microsphere (polymer-dopamine derived carbon, PDA-C) with high specific surface area was synthesized as sulfur host for high performance of lithium-sulfur batteries. We used KOH to adjust the pore size and surface area of the PDA-C materials, and then impregnated sulfur into the PDA-C samples by vapor-melting diffusion method. Effects of pore size of the PDA-C samples on the electrochemical performance of the PDA-C@sulfur cathodes were systematically investigated. Raman spectra indicated an enhanced trend of the degree of graphitization of the PDA-C samples with increasing calcination temperature. The surface area of the PDA-C samples increases with amount of the KOH in the pore-creating process. The graphitized porous N-doped carbon provides the high electronic conductive network. Meanwhile, the PDA-C with high surface area and uniform micropores ensures a high interaction toward sulfur as well as the high dispersion of nanoscale sulfur layer on it. The microporous PDA-C@S cathode material exhibits the excellent high rate discharge capability (636 mA h g −1 at 2.0 C) and good low/high-rate cycling stability (893 mA h g −1 (0.5 C) and 608 mA h g −1 (2.0 C) over 100 and 300 cycles). Cyclic voltammogram curves and electrochemical impedance plots show that both the impedance and polarization of the cells increase with decreasing pore size

  20. A multi-electron redox mediator for redox-targeting lithium-sulfur flow batteries

    Science.gov (United States)

    Li, Guochun; Yang, Liuqing; Jiang, Xi; Zhang, Tianran; Lin, Haibin; Yao, Qiaofeng; Lee, Jim Yang

    2018-02-01

    The lithium-sulfur flow battery (LSFB) is a new addition to the rechargeable lithium flow batteries (LFBs) where sulfur or a sulfur compound is used as the cathode material against the lithium anode. We report here our evaluation of an organic sulfide - dimethyl trisulfide (DMTS), as 1) a catholyte of a LFB and 2) a multi-electron redox mediator for discharging and charging a solid sulfur cathode without any conductive additives. The latter configuration is also known as the redox-targeting lithium-sulfur flow battery (RTLSFB). The LFB provides an initial discharge capacity of 131.5 mAh g-1DMTS (1.66 A h L-1), which decreases to 59 mAh g-1DMTS (0.75 A h L-1) after 40 cycles. The RTLSFB delivers a significantly higher application performance - initial discharge capacity of 1225.3 mAh g-1sulfur (3.83 A h L-1), for which 1030.9 mAh g-1sulfur (3.23 A h L-1) is still available after 40 cycles. The significant increase in the discharge and charge duration of the LFB after sulfur addition indicates that DMTS is better used as a redox mediator in a RTLSFB than as a catholyte in a LFB.

  1. A Polysulfide-Infiltrated Carbon Cloth Cathode for High-Performance Flexible Lithium–Sulfur Batteries

    Directory of Open Access Journals (Sweden)

    Ji-Yoon Song

    2018-02-01

    Full Text Available For practical application of lithium–sulfur batteries (LSBs, it is crucial to develop sulfur cathodes with high areal capacity and cycle stability in a simple and inexpensive manner. In this study, a carbon cloth infiltrated with a sulfur-containing electrolyte solution (CC-S was utilized as an additive-free, flexible, high-sulfur-loading cathode. A freestanding carbon cloth performed double duty as a current collector and a sulfur-supporting/trapping material. The active material in the form of Li2S6 dissolved in a 1 M LiTFSI-DOL/DME solution was simply infiltrated into the carbon cloth (CC during cell fabrication, and its optimal loading amount was found to be in a range between 2 and 10 mg/cm2 via electrochemical characterization. It was found that the interwoven carbon microfibers retained structural integrity against volume expansion/contraction and that the embedded uniform micropores enabled a high loading and an efficient trapping of sulfur species during cycling. The LSB coin cell employing the CC-S electrode with an areal sulfur loading of 6 mg/cm2 exhibited a high areal capacity of 4.3 and 3.2 mAh/cm2 at C/10 for 145 cycles and C/3 for 200 cycles, respectively, with minor capacity loss (<0.03%/cycle. More importantly, such high performance could also be realized in flexible pouch cells with dimensions of 2 cm × 6 cm before and after 300 bending cycles. Simple and inexpensive preparation of sulfur cathodes using CC-S electrodes, therefore, has great potential for the manufacture of high-performance flexible LSBs.

  2. Binning of shallowly sampled metagenomic sequence fragments reveals that low abundance bacteria play important roles in sulfur cycling and degradation of complex organic polymers in an acid mine drainage community

    Science.gov (United States)

    Dick, G. J.; Andersson, A.; Banfield, J. F.

    2007-12-01

    not expected to reflect the tetranucleotide frequency signature of the host genome. Four unknown tetranucleotide frequency clusters with significant sequence (6 Mb total) were noted and analyzed further. Based on phylogenetic markers and BLAST results, these clusters represent low abundance bacteria including Acintobacteria, Firmicutes, and Proteobacteria. Functional analysis of these clusters revealved that the low- abundance bacteria harbor genes that could potentially encode important ecosystem functions such as sulfur utilization (e.g. polysulfide reductase) and polymer degradation (e.g. chitinase and glycoside hydrolase). We conclude that ESOM clustering of tetranucleotide frequency patterns is an effective method for rapidly binning shotgun community genomic sequences and a valuable tool for analyzing minor community members, which despite their low abundance may play crucial ecological roles.

  3. Nitrogen/Sulfur-Codoped Carbon Materials from Chitosan for Supercapacitors

    Science.gov (United States)

    Li, Mei; Han, Xianlong; Chang, Xiaoqing; Yin, Wenchao; Ma, Jingyun

    2016-08-01

    d-Methionine and chitosan have been used for fabrication of nitrogen/sulfur-codoped carbon materials by a hydrothermal process followed by carbonization at 750°C for 3 h. The as-prepared carbon materials showed enhanced electrochemical performance, combining electrical double-layer capacitance with pseudocapacitance owing to the doping with sulfur and nitrogen. The specific capacitance of the obtained carbon material reached 135 F g-1 at current density of 1 A g-1, which is much higher than undoped chitosan (67 F g-1). The capacitance retention of the carbon material was almost 97.2% after 5000 cycles at current density of 1 A g-1. With such improved electrochemical performance, the nitrogen/sulfur-codoped carbon material may have promising potential for use in energy-storage electrodes of supercapacitors.

  4. 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.

  5. Large scale disposal of waste sulfur: From sulfide fuels to sulfate sequestration

    International Nuclear Information System (INIS)

    Rappold, T.A.; Lackner, K.S.

    2010-01-01

    Petroleum industries produce more byproduct sulfur than the market can absorb. As a consequence, most sulfur mines around the world have closed down, large stocks of yellow sulfur have piled up near remote operations, and growing amounts of toxic H 2 S are disposed of in the subsurface. Unless sulfur demand drastically increases or thorough disposal practices are developed, byproduct sulfur will persist as a chemical waste problem on the scale of 10 7 tons per year. We review industrial practices, salient sulfur chemistry, and the geochemical cycle to develop sulfur management concepts at the appropriate scale. We contend that the environmentally responsible disposal of sulfur would involve conversion to sulfuric acid followed by chemical neutralization with equivalent amounts of base, which common alkaline rocks can supply cheaply. The resulting sulfate salts are benign and suitable for brine injection underground or release to the ocean, where they would cause minimal disturbance to ecosystems. Sequestration costs can be recouped by taking advantage of the fuel-grade thermal energy released in the process of oxidizing reduced compounds and sequestering the products. Sulfate sequestration can eliminate stockpiles and avert the proliferation of enriched H 2 S stores underground while providing plenty of carbon-free energy to hydrocarbon processing.

  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. The effects of land use on fluvial sediment chemistry for the conterminous U.S. - results from the first cycle of the NAWQA Program: trace and major elements, phosphorus, carbon, and sulfur.

    Science.gov (United States)

    Horowitz, Arthur J; Stephens, Verlin C

    2008-08-01

    In 1991, the U.S. Geological Survey (USGS) began the first cycle of its National Water Quality Assessment (NAWQA) Program. The Program encompassed 51 river basins that collectively accounted for more than 70% of the total water use (excluding power generation), and 50% of the drinking water supply in the U.S. The basins represented a variety of hydrologic settings, rock types (geology), land-use categories, and population densities. One aspect of the first cycle included bed sediment sampling; sites were chosen to represent baseline and important land-use categories (e.g., agriculture, urban) in each basin. In total, over 1200 bed sediment samples were collected. All samples were size-limited (or=95% of the concentrations present), rather than total-recoverable chemical data. Land-use percentages, upstream underlying geology, and population density were determined for each site and evaluated to asses their relative influence on sediment chemistry. Baseline concentrations for the entire U.S. also were generated from a subset of all the samples, and are based on material collected from low population (sediment chemistry. The only land-use category that appears to substantially affect sediment chemistry is percent urban, and this result is mirrored by population density; in fact, the latter appears more consistent than the former.

  9. Pyrite sulfur isotopes reveal glacial-interglacial environmental changes

    Science.gov (United States)

    Pasquier, Virgil; Sansjofre, Pierre; Rabineau, Marina; Revillon, Sidonie; Houghton, Jennifer; Fike, David A.

    2017-06-01

    The sulfur biogeochemical cycle plays a key role in regulating Earth’s surface redox through diverse abiotic and biological reactions that have distinctive stable isotopic fractionations. As such, variations in the sulfur isotopic composition (δ34S) of sedimentary sulfate and sulfide phases over Earth history can be used to infer substantive changes to the Earth’s surface environment, including the rise of atmospheric oxygen. Such inferences assume that individual δ34S records reflect temporal changes in the global sulfur cycle; this assumption may be well grounded for sulfate-bearing minerals but is less well established for pyrite-based records. Here, we investigate alternative controls on the sedimentary sulfur isotopic composition of marine pyrite by examining a 300-m drill core of Mediterranean sediments deposited over the past 500,000 y and spanning the last five glacial-interglacial periods. Because this interval is far shorter than the residence time of marine sulfate, any change in the sulfur isotopic record preserved in pyrite (δ34Spyr) necessarily corresponds to local environmental changes. The stratigraphic variations (>76‰) in the isotopic data reported here are among the largest ever observed in pyrite, and are in phase with glacial-interglacial sea level and temperature changes. In this case, the dominant control appears to be glacial-interglacial variations in sedimentation rates. These results suggest that there exist important but previously overlooked depositional controls on sedimentary sulfur isotope records, especially associated with intervals of substantial sea level change. This work provides an important perspective on the origin of variability in such records and suggests meaningful paleoenvironmental information can be derived from pyrite δ34S records.

  10. 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..

  11. Investigating the implications of a new-build hybrid power system for Roll-on/Roll-off cargo ships from a sustainability perspective – A life cycle assessment case study

    International Nuclear Information System (INIS)

    Ling-Chin, Janie; Roskilly, Anthony P.

    2016-01-01

    Highlights: • Resources, emissions and impact from manufacture to end of life were estimated. • Operating diesel gensets and disposing metallic scrap were significant processes. • Correlations between fuel consumption and impact categories were identified. • The influence of the end of life scenarios on ecotoxicity potential was studied. • Environmental benefits of the hybrid system were compared and verified. - Abstract: Marine transport has been essential for international trade. Concern for its environmental impact was growing among regulators, classification societies, ship operators, ship owners, and other stakeholders. By applying life cycle assessment, this article aimed to assess the impact of a new-build hybrid system (i.e. an electric power system which incorporated lithium ion batteries, photovoltaic systems and cold-ironing) designed for Roll-on/Roll-off cargo ships. The study was carried out based on a bottom-up integrated system approach using the optimised operational profile and background information for manufacturing processes, mass breakdown and end of life management plans. Resources such as metallic and non-metallic materials and energy required for manufacture, operation, maintenance, dismantling and scrap handling were estimated. During operation, 1.76 × 10 8 kg of marine diesel oil was burned, releasing carbon monoxide, carbon dioxide, particulate matter, hydrocarbons, nitrogen oxides and sulphur dioxide which ranged 5–8 orders of magnitude. The operation of diesel gensets was the primary cause of impact categories that were relevant to particulate matter or respiratory inorganic health issues, photochemical ozone creation, eutrophication, acidification, global warming and human toxicity. Disposing metallic scrap was accountable for the most significant impact category, ecotoxicity potential. The environmental benefits of the hybrid power system in most impact categories were verified in comparison with a conventional power

  12. 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)

  13. 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.

  14. Geology and stable isotope geochemistry of Paleoarchean sulfur. Formation, preservation and geobiology of ancient pyrite and barite

    NARCIS (Netherlands)

    Roerdink, D.L.|info:eu-repo/dai/nl/318834340

    2013-01-01

    Sulfur isotopes in ancient sulfate and sulfide minerals provide a comprehensive record of microbial processes involved in the early sulfur cycle on Earth. However, the interpretation of these isotopic signatures requires information on the geological context of such samples, because abiotic

  15. 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.

  16. 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

  17. Emissions of carbon, nitrogen, and sulfur from biomass burning in Nigeria

    International Nuclear Information System (INIS)

    Akeredolu, F.; Isichei, A.O.

    1991-01-01

    The atmospheric implications of the effects of burning of vegetation in Nigeria are discussed. The following topics are explored: the extent of biomass burning by geographical area; estimates of emission rates of carbon, nitrogen and sulfur; and the impact on biogeochemical cycling of elements. The results suggest that biomass burning generates a measurable impact on the cycling of carbon and nitrogen

  18. Electric/Hybrid Vehicle Simulation

    Science.gov (United States)

    Slusser, R. A.; Chapman, C. P.; Brennand, J. P.

    1985-01-01

    ELVEC computer program provides vehicle designer with simulation tool for detailed studies of electric and hybrid vehicle performance and cost. ELVEC simulates performance of user-specified electric or hybrid vehicle under user specified driving schedule profile or operating schedule. ELVEC performs vehicle design and life cycle cost analysis.

  19. 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....

  20. 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.

  1. FiveS rRNA sequences and fatty acid profiles of colourless sulfur-oxidising bacteria

    Digital Repository Service at National Institute of Oceanography (India)

    LokaBharathi, P.A.; Ortiz-conde, B.A.; Nair, S.; Chandramohan, D.; Colwell, R.R.

    Colourless sulfur-oxidising bacteria have been encountered extensively in the oxygen minimum layers of the Arabian Sea. These oligotrophs have been known to mediate nitrogen cycle reductively even under autotrophic conditions. Some...

  2. Macroporous Activated Carbon Derived from Rapeseed Shell for Lithium–Sulfur Batteries

    Directory of Open Access Journals (Sweden)

    Mingbo Zheng

    2017-10-01

    Full Text Available Lithium–sulfur batteries have drawn considerable attention because of their extremely high energy density. Activated carbon (AC is an ideal matrix for sulfur because of its high specific surface area, large pore volume, small-size nanopores, and simple preparation. In this work, through KOH activation, AC materials with different porous structure parameters were prepared using waste rapeseed shells as precursors. Effects of KOH amount, activated temperature, and activated time on pore structure parameters of ACs were studied. AC sample with optimal pore structure parameters was investigated as sulfur host materials. Applied in lithium–sulfur batteries, the AC/S composite (60 wt % sulfur exhibited a high specific capacity of 1065 mAh g−1 at 200 mA g−1 and a good capacity retention of 49% after 1000 cycles at 1600 mA g−1. The key factor for good cycling stability involves the restraining effect of small-sized nanopores of the AC framework on the diffusion of polysulfides to bulk electrolyte and the loss of the active material sulfur. Results demonstrated that AC materials derived from rapeseed shells are promising materials for sulfur loading.

  3. Stabilized sulfur as cathodes for room temperature sodium-ion batteries.

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yunhua [Univ. of Maryland, College Park, MD (United States). Dept. of Chemical and Biomolecular Engineering; Liu, Yang [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Center for Integrated Nanotechnologies; Zhu, Yujie [Univ. of Maryland, College Park, MD (United States). Dept. of Chemical and Biomolecular Engineering; Zheng, Shiyou [Univ. of Maryland, College Park, MD (United States). Dept. of Chemical and Biomolecular Engineering; Liu, Yihang [Univ. of Maryland, College Park, MD (United States). Dept. of Chemical and Biomolecular Engineering; Luo, Chao [Univ. of Maryland, College Park, MD (United States). Dept. of Chemical and Biomolecular Engineering; Gaskell, Karen [Univ. of Maryland, College Park, MD (United States). Dept. of Chemistry and Biochemistry; Eichhorn, Bryan [Univ. of Maryland, College Park, MD (United States). Dept. of Chemistry and Biochemistry; Wang, Chunsheng [Univ. of Maryland, College Park, MD (United States). Dept. of Chemical and Biomolecular Engineering

    2013-05-01

    Sodium-sulfur batteries, offering high capacity and low cost, are promising alternative to lithium-ion batteries for large-scale energy storage applications. The conventional sodium-sulfur batteries, operating at a high temperature of 300–350°C in a molten state, could lead to severe safety problems. However, the room temperature sodium-sulfur batteries using common organic liuid electrolytes still face a significant challenge due to the dissolution of intermediate sodium polysulfides. For this study, we developed room temperatue sodium-sulfur batteries using a unique porous carbon/sulfur (C/S) composite cathode, which was synthesized by infusing sulfur vapor into porous carbon sphere particles at a high temperatrure of 600°C. The porous C/S composites delivered a reversible capacity of ~860 mAh/g and retained 83% after 300 cycles. The Coulombic efficiency of as high as 97% was observed over 300 cycles. The superior electrochemical performance is attrbuted to the super sulfur stability as evidenced by its lower sensitivity to probe beam irradiation in TEM, XPS and Raman charaterization and high evaperation temperature in TGA. The results make it promising for large-scale grid energy storage and electric vehicles.

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

    Science.gov (United States)

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

    2015-06-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

  6. Chloride-Reinforced Carbon Nanofiber Host as Effective Polysulfide Traps in Lithium-Sulfur Batteries.

    Science.gov (United States)

    Fan, Lei; Zhuang, Houlong L; Zhang, Kaihang; Cooper, Valentino R; Li, Qi; Lu, Yingying

    2016-12-01

    Lithium-sulfur (Li-S) battery is one of the most promising alternatives for the current state-of-the-art lithium-ion batteries due to its high theoretical energy density and low production cost from the use of sulfur. However, the commercialization of Li-S batteries has been so far limited to the cyclability and the retention of active sulfur materials. Using co-electrospinning and physical vapor deposition procedures, we created a class of chloride-carbon nanofiber composites, and studied their effectiveness on polysulfides sequestration. By trapping sulfur reduction products in the modified cathode through both chemical and physical confinements, these chloride-coated cathodes are shown to remarkably suppress the polysulfide dissolution and shuttling between lithium and sulfur electrodes. From adsorption experiments and theoretical calculations, it is shown that not only the sulfide-adsorption effect but also the diffusivity in the vicinity of these chlorides materials plays an important role on the reversibility of sulfur-based cathode upon repeated cycles. Balancing the adsorption and diffusion effects of these nonconductive materials could lead to the enhanced cycling performance of an Li-S cell. Electrochemical analyses over hundreds of cycles indicate that cells containing indium chloride-modified carbon nanofiber outperform cells with other halogenated salts, delivering an average specific capacity of above 1200 mAh g -1 at 0.2 C.

  7. Atividade e população microbiana envolvida nas transformações do enxofre em solos com diferentes vegetações Activity and microbial populations involved in sulfur cycling in soils with different vegetations

    Directory of Open Access Journals (Sweden)

    Cristiane Rêgo Oliveira Pinto

    2002-12-01

    Full Text Available O objetivo deste trabalho foi determinar as populações microbianas e suas atividades envolvidas no ciclo do S, de solos virgem e cultivado, e as suas relações com as diferentes frações de S no solo. Das populações de microrganismos pesquisados, apenas foram encontradas as bactérias autótrofas oxidantes de S0 em pH 5,0 e as heterótrofas oxidantes de tiossulfato, que representaram menos de 0,1% das bactérias totais. A média das bactérias autótrofas foi o dobro das heterótrofas. As maiores contagens de bactérias totais, autótrofas e heterótrofas foram encontradas nos solos com milho, de pastagem e de floresta integrada, respectivamente. A atividade da arilsulfatase foi maior em solo de floresta integrada e a da rodanase em solo de pastagem. A arilsulfatase correlacionou com as populações de heterotróficos, C orgânico, S total, S orgânico, matéria orgânica e umidade do solo; e a rodanase com C orgânico, S total e S orgânico. Os teores de S orgânico e sulfato foram de 94-98% e 2-6% do S total, respectivamente. Os maiores teores de S total e orgânico foram encontrados no solo de floresta integrada. O S total correlacionou com o S orgânico, umidade e matéria orgânica, e o S orgânico com a matéria orgânica.The objective of this work was to assess the microbial populations and its activities involved in the S cycle, of virgin and cultivated soils, and its relationships with the different fractions of S in the soil. The influence of soils with different vegetations on microbiological and biochemical characteristics was investigated. Out of the different populations of microorganisms examined, only the S0-oxidizing autotrophic bacteria and thiosulfate-oxidizing heterotrophs that represented less than 0.1% of the total bacteria were found. The average of autotrophs was double that of the heterotrophs. The highest counts of total bacteria, autotrophic and heterotrophic microorganisms were found in corn, pasture and forest

  8. A control-oriented lithium-ion battery pack model for plug-in hybrid electric vehicle cycle-life studies and system design with consideration of health management

    Science.gov (United States)

    Cordoba-Arenas, Andrea; Onori, Simona; Rizzoni, Giorgio

    2015-04-01

    A crucial step towards the large-scale introduction of plug-in hybrid electric vehicles (PHEVs) in the market is to reduce the cost of its battery systems. Currently, battery cycle- and calendar-life represents one of the greatest uncertainties in the total life-cycle cost of battery systems. The field of battery aging modeling and prognosis has seen progress with respect to model-based and data-driven approaches to describe the aging of battery cells. However, in real world applications cells are interconnected and aging propagates. The propagation of aging from one cell to others exhibits itself in a reduced battery system life. This paper proposes a control-oriented battery pack model that describes the propagation of aging and its effect on the life span of battery systems. The modeling approach is such that it is able to predict pack aging, thermal, and electrical dynamics under actual PHEV operation, and includes consideration of random variability of the cells, electrical topology and thermal management. The modeling approach is based on the interaction between dynamic system models of the electrical and thermal dynamics, and dynamic models of cell aging. The system-level state-of-health (SOH) is assessed based on knowledge of individual cells SOH, pack electrical topology and voltage equalization approach.

  9. 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.

  10. Energy Efficiency Comparison between Hydraulic Hybrid and Hybrid Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Jia-Shiun Chen

    2015-05-01

    Full Text Available Conventional vehicles tend to consume considerable amounts of fuel, which generates exhaust gases and environmental pollution during intermittent driving cycles. Therefore, prospective vehicle designs favor improved exhaust emissions and energy consumption without compromising vehicle performance. Although pure electric vehicles feature high performance and low pollution characteristics, their limitations are their short driving range and high battery costs. Hybrid electric vehicles (HEVs are comparatively environmentally friendly and energy efficient, but cost substantially more compared with conventional vehicles. Hydraulic hybrid vehicles (HHVs are mainly operated using engines, or using alternate combinations of engine and hydraulic power sources while vehicles accelerate. When the hydraulic system accumulator is depleted, the conventional engine reengages; concurrently, brake-regenerated power is recycled and reused by employing hydraulic motor–pump modules in circulation patterns to conserve fuel and recycle brake energy. This study adopted MATLAB Simulink to construct complete HHV and HEV models for backward simulations. New European Driving Cycles were used to determine the changes in fuel economy. The output of power components and the state-of-charge of energy could be retrieved. Varying power component models, energy storage component models, and series or parallel configurations were combined into seven different vehicle configurations: the conventional manual transmission vehicle, series hybrid electric vehicle, series hydraulic hybrid vehicle, parallel hybrid electric vehicle, parallel hydraulic hybrid vehicle, purely electric vehicle, and hydraulic-electric hybrid vehicle. The simulation results show that fuel consumption was 21.80% lower in the series hydraulic hybrid vehicle compared to the series hybrid electric vehicle; additionally, fuel consumption was 3.80% lower in the parallel hybrid electric vehicle compared to the

  11. ADVANCED SULFUR CONTROL CONCEPTS FOR HOT-GAS DESULFURIZATION TECHNOLOGY

    Energy Technology Data Exchange (ETDEWEB)

    A. LOPEZ ORTIZ; D.P. HARRISON; F.R. GROVES; J.D. WHITE; S. ZHANG; W.-N. HUANG; Y. ZENG

    1998-10-31

    a twenty-five-cycle test. The sorbent was exposed for 58 consecutive days to temperatures between 600°C and 800°C and gas atmospheres from highly reducing to highly oxidizing without measurable loss of sulfur capacity or reactivity. In the process analysis phase of this study, a two-stage desulfurization process using cerium sorbent with SO2 regeneration followed by zinc sorbent with dilute O2 regeneration was compared to a single-stage process using zinc sorbent and O2 regeneration with SO2 in the regeneration product gas converted to elemental sulfur using the direct sulfur recovery process (DSRP). Material and energy balances were calculated using the process simulation package PRO/II. Major process equipment was sized and a preliminary economic analysis completed. Sorbent replacement rate, which is determined by the multicycle sorbent durability, was found to be the most significant factor in both processes. For large replacement rates corresponding to average sorbent lifetimes of 250 cycles or less, the single-stage zinc sorbent process with DSRP was estimated to be less costly. However, the cost of the two-stage cerium sorbent process was more sensitive to sorbent replacement rate, and, as the required replacement rate decreased, the economics of the two-stage process improved. For small sorbent replacement rates corresponding to average sorbent lifetimes of 1000 cycles or more, the two-stage cerium process was estimated to be less costly. In the relatively wide middle range of sorbent replacement rates, the relative economics of the two processes depends on other factors such as the unit cost of sorbents, oxygen, nitrogen, and the relative capital costs.

  12. Advanced sulfur control concepts for hot-gas desulfurization technology

    International Nuclear Information System (INIS)

    Lopez Ortiz, A.; Harrison, D.P.; Groves, F.R.; White, J.D.; Zhang, S.; Huang, W.N.; Zeng, Y.

    1998-01-01

    twenty-five-cycle test. The sorbent was exposed for 58 consecutive days to temperatures between 600C and 800C and gas atmospheres from highly reducing to highly oxidizing without measurable loss of sulfur capacity or reactivity. In the process analysis phase of this study, a two-stage desulfurization process using cerium sorbent with SO2 regeneration followed by zinc sorbent with dilute O2 regeneration was compared to a single-stage process using zinc sorbent and O2 regeneration with SO2 in the regeneration product gas converted to elemental sulfur using the direct sulfur recovery process (DSRP). Material and energy balances were calculated using the process simulation package PRO/II. Major process equipment was sized and a preliminary economic analysis completed. Sorbent replacement rate, which is determined by the multicycle sorbent durability, was found to be the most significant factor in both processes. For large replacement rates corresponding to average sorbent lifetimes of 250 cycles or less, the single-stage zinc sorbent process with DSRP was estimated to be less costly. However, the cost of the two-stage cerium sorbent process was more sensitive to sorbent replacement rate, and, as the required replacement rate decreased, the economics of the two-stage process improved. For small sorbent replacement rates corresponding to average sorbent lifetimes of 1000 cycles or more, the two-stage cerium process was estimated to be less costly. In the relatively wide middle range of sorbent replacement rates, the relative economics of the two processes depends on other factors such as the unit cost of sorbents, oxygen, nitrogen, and the relative capital costs

  13. 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)

  14. 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.

  15. Hierarchical sulfur-impregnated hydrogenated TiO2 mesoporous spheres comprising anatase nanosheets with highly exposed (001) facets for advanced Li-S batteries

    Science.gov (United States)

    Yuan, Changzhou; Zhu, Siqi; Cao, Hui; Hou, Linrui; Lin, Jingdong

    2016-01-01

    In this contribution, we purposefully designed hierarchical hydrogenated TiO2 spheres (HTSs) constructed from ultrathin anatase nanosheets with highly exposed (001) facets, and further utilized them as an efficient encapsulated host of sulfur species for advanced Li-S batteries (LSBs). Strikingly, the as-fabricated hybrid S/HTSs cathode exhibited high Coulombic efficiency (>94%), exceptional long cycling performance (capacity decay of ˜0.399% per cycle at 0.5 C), and large reversible discharge capacity (˜579 mAh g-1 at 2.0 C) at high C rates, benefiting from better electronic conductivity, smaller charge transfer resistance and strong chemical bonding between {{{{S}}}n}2- and the reduced (001) facets of HTSs, according to experimental measurements and systematical theoretical calculations. More significantly, our in-depth insights into the mechanism involved in the hybrid S/HTSs could efficiently guide future design, optimization and synthesis of other metal oxide-based matrixes with specific exposed crystal facets for next-generation advanced LSBs.

  16. A comparative study on low cycle fatigue behaviour of nano and micro Al2O3 reinforced AA2014 particulate hybrid composites

    Directory of Open Access Journals (Sweden)

    R. Senthilkumar

    2015-01-01

    Full Text Available Aluminium based metal matrix composites have drawn more attraction due to their improved properties in structural applications for the past two decades. The fatigue behaviour of composite materials needs to be studied for their structural applications. In this work, powder metallurgy based aluminium (AA2014 alloy reinforced with micro and nano-sized alumina particles were fabricated and consolidated with the hot extrusion process. The evaluation of mechanical properties in the extruded composite was carried out. This composite was subjected to low cycle fatigue test with a constant strain rate. Scanning Electron Microscope (SEM and Transmission Electron Microscope (TEM images were used to evaluate the fatigue behaviour of aluminium-nano composite samples. Enhanced mechanical properties were exhibited by the nano alumina reinforced aluminium composites, when compared to the micron sized alumina reinforced composites. The failure cycle is observed to be higher for the nano alumina reinforced composites when compared with micron sized alumina composites due to a lower order of induced plastic strain.

  17. Hybrid life-cycle environmental and cost inventory of sewage sludge treatment and end-use scenarios: a case study from China.

    Science.gov (United States)

    Murray, Ashley; Horvath, Arpad; Nelson, Kara L

    2008-05-01

    Sewage sludge management poses environmental, economic, and political challenges for wastewater treatment plants and municipalities around the globe. To facilitate more informed and sustainable decision making, this study used life-cycle inventory (LCI) to expand upon previous process-based LCIs of sewage sludge treatmenttechnologies. Additionally, the study evaluated an array of productive end-use options for treated sewage sludge, such as fertilizer and as an input into construction materials, to determine how the sustainability of traditional manufacturing processes changes with sludge as a replacement for other raw inputs. The inclusion of the life-cycle of necessary inputs (such as lime) used in sludge treatment significantly impacts the sustainability profiles of different treatment and end-use schemes. Overall, anaerobic digestion is generally the optimal treatment technology whereas incineration, particularly if coal-fired, is the most environmentally and economically costly. With respect to sludge end use, offsets are greatest for the use of sludge as fertilizer, but all of the productive uses of sludge can improve the sustainability of conventional manufacturing practices. The results are intended to help inform and guide decisions about sludge handling for existing wastewater treatment plants and those that are still in the planning phase in cities around the world. Although additional factors must be considered when selecting a sludge treatment and end-use scheme, this study highlights how a systems approach to planning can contribute significantly to improving overall environmental sustainability.

  18. MnO2-graphene nanosheets wrapped mesoporous carbon/sulfur composite for lithium-sulfur batteries

    Science.gov (United States)

    Li, Zhengzheng

    2018-02-01

    MnO2-graphene nanosheets wrapped mesoporous carbon/sulfur (MGN@MC/S) composite is successfully synthesized derived from metal-organic frameworks and investigated as cathode for lithium-ion batteries. Used as cathode, MGN@MC/S composite possesses electronic conductivity network for redox electron transfer and strong chemical bonding to lithium polysulfides, which enables low capacity loss to be achieved. MGN@MC/S cathodes exhibit high reversible capacity of 1475 mA h g-1 at 0.1 C and an ultra-low capacity fading of 0.042% per cycle at 1 C over 450 cycles.

  19. Atomic Iron Catalysis of Polysulfide Conversion in Lithium-Sulfur Batteries.

    Science.gov (United States)

    Liu, Zhenzhen; Zhou, Lei; Ge, Qi; Chen, Renjie; Ni, Mei; Utetiwabo, Wellars; Zhang, Xiaoling; Yang, Wen

    2018-06-13

    Lithium-sulfur batteries have been regarded as promising candidates for energy storage because of their high energy density and low cost. It is a main challenge to develop long-term cycling stability battery. Here, a catalytic strategy is presented to accelerate reversible transformation of sulfur and its discharge products in lithium-sulfur batteries. This is achieved with single-atomic iron active sites in porous nitrogen-doped carbon, prepared by polymerizing and carbonizing diphenylamine in the presence of iron phthalocyanine and a hard template. The Fe-PNC/S composite electrode exhibited a high discharge capacity (427 mAh g -1 ) at a 0.1 C rate after 300 cycles with the Columbic efficiency of above 95.6%. Besides, the electrode delivers much higher capacity of 557.4 mAh g -1 at 0.5 C over 300 cycles. Importantly, the Fe-PCN/S has a smaller phase nucleation overpotential of polysulfides than nitrogen-doped carbon alone for the formation of nanoscale of Li 2 S as revealed by ex situ SEM, which enhance lithium-ion diffusion in Li 2 S, and therefore a high rate performance and remarkable cycle life of Li-sulfur batteries were achieved. Our strategy paves a new way for polysulfide conversion with atomic iron catalysis to exploit high-performance lithium-sulfur batteries.

  20. Functional Differentiation of Three Pores for Effective Sulfur Confinement in Li-S Battery.

    Science.gov (United States)

    Wang, Qian; Yang, Minghui; Wang, Zhen-Bo; Li, Chao; Gu, Da-Ming

    2018-03-01

    Shuttle effect of the dissolved intermediates is regarded as the primary cause that leads to fast capacity degradation of Li-S battery. Herein, a microporous carbon-coated sulfur composite with novel rambutan shape (R-S@MPC) is synthesized from microporous carbon-coated rambutan-like zinc sulfide (R-ZnS@MPC), via an in situ oxidation process. The R-ZnS is employed as both template and sulfur precursor. The carbon frame of R-S@MPC composite possesses three kinds of pores that are distinctly separated from each other in space and are endowed with the exclusive functions. The central macropore serves as buffer pool to accommodate the dissolved lithium polysulfides (LPSs) and volumetric variation during cycling. The marginal straight-through mesoporous, connected with the central macropore, takes the responsibility of sulfur storage. The micropores, evenly distributed in the outer carbon shell of the as-synthesized R-S@MPC, enable the blockage of LPSs. These pores are expected to perform their respective single function, and collaborate synergistically to suppress the sulfur loss. Therefore, it delivers an outstanding cycling stability, decay rate of 0.013% cycle -1 after 500 cycles at 1 C, when the sulfur loading is kept at 4 mg cm -2 . © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. 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;…

  2. 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.

  3. 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.

  4. 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...

  5. 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...

  6. 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)

  7. Tetrathionate and Elemental Sulfur Shape the Isotope Composition of Sulfate in Acid Mine Drainage

    Directory of Open Access Journals (Sweden)

    Nurgul Balci

    2017-08-01

    Full Text Available Sulfur compounds in intermediate valence states, for example elemental sulfur, thiosulfate, and tetrathionate, are important players in the biogeochemical sulfur cycle. However, key understanding about the pathways of oxidation involving mixed-valance state sulfur species is still missing. Here we report the sulfur and oxygen isotope fractionation effects during the oxidation of tetrathionate (S4O62− and elemental sulfur (S° to sulfate in bacterial cultures in acidic conditions. Oxidation of tetrathionate by Acidithiobacillus thiooxidans produced thiosulfate, elemental sulfur and sulfate. Up to 34% of the tetrathionate consumed by the bacteria could not be accounted for in sulfate or other intermediate-valence state sulfur species over the experiments. The oxidation of tetrathionate yielded sulfate that was initially enriched in 34S (ε34SSO4−S4O6 by +7.9‰, followed by a decrease to +1.4‰ over the experiment duration, with an average ε34SSO4−S4O6 of +3.5 ± 0.2‰ after a month of incubation. We attribute this significant sulfur isotope fractionation to enzymatic disproportionation reactions occurring during tetrathionate decomposition, and to the incomplete transformation of tetrathionate into sulfate. The oxygen isotope composition of sulfate (δ18OSO4 from the tetrathionate oxidation experiments indicate that 62% of the oxygen in the formed sulfate was derived from water. The remaining 38% of the oxygen was either inherited from the supplied tetrathionate, or supplied from dissolved atmospheric oxygen (O2. During the oxidation of elemental sulfur, the product sulfate became depleted in 34S between −1.8 and 0‰ relative to the elemental sulfur with an average for ε34SSO4−S0 of −0.9 ± 0.2‰ and all the oxygen atoms in the sulfate derived from water with an average normal oxygen isotope fractionation (ε18OSO4−H2O of −4.4‰. The differences observed in δ18OSO4 and the sulfur isotope composition of sulfate (δ34SSO4

  8. Insights into the iron and sulfur energetic metabolism of Acidithiobacillus ferrooxidans by microarray transcriptome profiling

    Energy Technology Data Exchange (ETDEWEB)

    R. Quatrini; C. Appia-Ayme; Y. Denis; J. Ratouchniak; F. Veloso; J. Valdes; C. Lefimil; S. Silver; F. Roberto; O. Orellana; F. Denizot; E. Jedlicki; D. Holmes; V. Bonnefoy

    2006-09-01

    Acidithiobacillus ferrooxidans is a well known acidophilic, chemolithoautotrophic, Gram negative, bacterium involved in bioleaching and acid mine drainage. In aerobic conditions, it gains energy mainly from the oxidation of ferrous iron and/or reduced sulfur compounds present in ores. After initial oxidation of the substrate, electrons from ferrous iron or sulfur enter respiratory chains and are transported through several redox proteins to oxygen. However, the oxidation of ferrous iron and reduced sulfur compounds has also to provide electrons for the reduction of NAD(P) that is subsequently required for many metabolic processes including CO2 fixation. To help to unravel the enzymatic pathways and the electron transfer chains involved in these processes, a genome-wide microarray transcript profiling analysis was carried out. Oligonucleotides corresponding to approximately 3000 genes of the A. ferrooxidans type strain ATCC23270 were spotted onto glass-slides and hybridized with cDNA retrotranscribed from RNA extracted from ferrous iron and sulfur grown cells. The genes which are preferentially transcribed in ferrous iron conditions and those preferentially transcribed in sulfur conditions were analyzed. The expression of a substantial number of these genes has been validated by real-time PCR, Northern blot hybridization and/or immunodetection analysis. Our results support and extend certain models of iron and sulfur oxidation and highlight previous observations regarding the possible presence of alternate electron pathways. Our findings also suggest ways in which iron and sulfur oxidation may be co-ordinately regulated. An accompanying paper (Appia-Ayme et al.) describes results pertaining to other metabolic functions.

  9. Energy Management Strategies for a Pneumatic-Hybrid Engine Based on Sliding Window Pattern Recognition Stratégies de gestion de l’énergie pour un moteur hybride pneumatique basées sur la reconnaissance du cycle de conduite

    Directory of Open Access Journals (Sweden)

    Ivanco A.

    2009-11-01

    Full Text Available This paper presents energy management strategies for a new hybrid pneumatic engine concept which is specific by its configuration in that it is not the vehicle but only the engine itself which is hybridized. Different energy management strategies are proposed in this paper. The first is called Causal Strategy (CS and implements a rule-based control technique. The second strategy, called Constant Penalty Coefficient (CPC, is based on the minimization of equivalent consumption, where the use of each energy source is formulated in a comparative unit. The balance between the consumption of different energy sources (chemical or pneumatic is achieved by the introduction of an equivalence factor. The third strategy is called Variable Penalty Coefficient (VPC. In fact, it is beneficial to consider the equivalence coefficient as variable within the amount of pneumatic energy stored in the air-tank i.e. state of charge, because the choice of propulsion mode should be different if the tank is full or empty. In this case, the penalty coefficient appears as a non linear function of the air-tank state of charge. Another way to adapt the penalty coefficient is to recognize a reference pattern during the driving cycle. The coefficient value can then be changed according to an optimized value found for each of the reference cycles. This strategy is called Driving Pattern Recognition (DPR. It involves a technique of sliding window pattern recognition. The concept is to convert the whole driving cycle into smaller pieces to which the equivalence factor can be appropriately adapted. This strategy is based on the assumption that the current driving situation does not change rapidly and thus the pattern is likely to continue into the near future. The identification window size is a parameter which has to be adjusted to attain the maximum of identification success over the reference cycle. We propose to define reference patterns as statistical models. The pattern

  10. A highly efficient polysulfide mediator for lithium-sulfur batteries

    Science.gov (United States)

    Liang, Xiao; Hart, Connor; Pang, Quan; Garsuch, Arnd; Weiss, Thomas; Nazar, Linda F.

    2015-01-01

    The lithium-sulfur battery is receiving intense interest because its theoretical energy density exceeds that of lithium-ion batteries at much lower cost, but practical applications are still hindered by capacity decay caused by the polysulfide shuttle. Here we report a strategy to entrap polysulfides in the cathode that relies on a chemical process, whereby a host—manganese dioxide nanosheets serve as the prototype—reacts with initially formed lithium polysulfides to form surface-bound intermediates. These function as a redox shuttle to catenate and bind ‘higher’ polysulfides, and convert them on reduction to insoluble lithium sulfide via disproportionation. The sulfur/manganese dioxide nanosheet composite with 75 wt% sulfur exhibits a reversible capacity of 1,300 mA h g-1 at moderate rates and a fade rate over 2,000 cycles of 0.036%/cycle, among the best reported to date. We furthermore show that this mechanism extends to graphene oxide and suggest it can be employed more widely.

  11. Durability of incinerator ash waste encapsulated in modified sulfur cement

    International Nuclear Information System (INIS)

    Kalb, P.D.; Heiser, J.H. III; Pietrzak, R.; Colombo, P.

    1991-01-01

    Waste form stability under anticipated disposal conditions is an important consideration for ensuring continued isolation of contaminants from the accessible environment. Modified sulfur cement is a relatively new material and has only recently been applied as a binder for encapsulation of mixed wastes. Little data are available concerning its long-term durability. Therefore, a series of property evaluation tests for both binder and waste-binder combinations have been conducted to examine potential waste form performance under storage and disposal conditions. These tests include compressive strength, biodegradation, radiation stability, water immersion, thermal cycling, and leaching. Waste form compressive strength increased with ash waste loadings to 30.5 MPa at a maximum incinerator ash loading of 43 wt %. Biodegradation testing resulted in no visible microbial growth of either bacteria or fungi. Initial radiation stability testing did not reveal statistically significant deterioration in structural integrity. Results of 90 day water immersion tests were dependent on the type of ash tested. There were no statistically significant changes in compressive strength detected after completion of thermal cycle testing. Radionuclides from ash waste encapsulated in modified sulfur cement leached between 5 and 8 orders of magnitude slower than the leach index criterion established by the Nuclear Regulatory Commission (NRC) for low-level radioactive waste. Modified sulfur cement waste forms containing up to 43 wt % incinerator fly ash passed EPA Toxicity Characteristic Leaching Procedure (TCLP) criteria for lead and cadmium leachability. 11 refs., 2 figs., 5 tabs

  12. 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

  13. Atmospheric sulfur and climate changes: a modelling study at mid and high-southern latitudes; Soufre atmospherique et changements climatiques: une etude de modelisation pour les moyennes et hautes latitudes Sud

    Energy Technology Data Exchange (ETDEWEB)

    Castebrunet, H

    2007-09-15

    The mid and high-southern latitudes are still marginally affected by anthropogenic sulfur emissions. They are the only regions in the world where the natural cycle of the atmospheric sulfur may still be observed. Sulfur aerosols are well-known for their radiative impact, and thus interact with climate. Climate can in turn affect atmospheric sulfur sources, distribution and chemistry. Antarctic ice cores provide information on the evolution of climate and sulfur deposition at the surface of the ice sheet at glacial-interglacial time scales. The aim of this thesis is to develop and use modeling towards a better understanding of the atmospheric sulfur cycle in antarctic and sub-antarctic regions. Ice core data are used to validate model results under glacial climate conditions. An Atmospheric General Circulation Model (AGCM) coupled to a sulfur chemistry module is used: the LMD-ZTSulfur model, version 4. An update of both the physical and chemical parts of the model. The model was first performed. The impact of there changes on modelled sulfur cycle are evaluated for modern climate. Further, boundary conditions are adapted to simulate the atmospheric circulation and sulfur cycle at the Last Glacial Maximum, approximately 20,000 years ago. In the model, sulfur is found to be highly sensitive to antarctic sea-ice coverage, which is still poorly known during the ice age. An original dataset of ice-age sea-ice coverage was developed. Its impact on the oceanic emissions of dimethyl sulfide, main precursor of sulfur aerosols at high-southern latitudes, is discussed. Using the same oceanic sulfur reservoirs as for present day climate, the model broadly reproduces the glacial deposits of sulfur aerosols on the Antarctic plateau, suggesting little impact of climate on oceanic sulfur production in the Antarctic region. Sensitivity tests were carried out to draw an up-to-date status of major uncertainties and difficulties facing future progress in understanding atmospheric

  14. Tubeworm May Live Longer by Cycling Its Sulfur Downward

    OpenAIRE

    Cordes, Erik E; Arthur, Michael A; Shea, Katriona; Arvidson, Rolf S; Fisher, Charles R

    2005-01-01

    The deep-sea vestimentiferan tubeworm Lamellibrachia luymesi forms large aggregations at hydrocarbon seeps in the Gulf of Mexico that may persist for over 250 y. Here, we present the results of a diagenetic model in which tubeworm aggregation persistence is achieved through augmentation of the supply of sulfate to hydrocarbon seep sediments. In the model, L. luymesi releases the sulfate generated by its internal, chemoautotrophic, sulfide-oxidizing symbionts through posterior root-like extens...

  15. PUMP DESIGN AND COMPUTATIONAL FLUID DYNAMIC ANALYSIS FOR HIGH TEMPERATURE SULFURIC ACID TRANSFER SYSTEM

    Directory of Open Access Journals (Sweden)

    JUNG-SIK CHOI

    2014-06-01

    Full Text Available In this study, we proposed a newly designed sulfuric acid transfer system for the sulfur-iodine (SI thermochemical cycle. The proposed sulfuric acid transfer system was evaluated using a computational fluid dynamics (CFD analysis for investigating thermodynamic/hydrodynamic characteristics and material properties. This analysis was conducted to obtain reliable continuous operation parameters; in particular, a thermal analysis was performed on the bellows box and bellows at amplitudes and various frequencies (0.1, 0.5, and 1.0 Hz. However, the high temperatures and strongly corrosive operating conditions of the current sulfuric acid system present challenges with respect to the structural materials of the transfer system. To resolve this issue, we designed a novel transfer system using polytetrafluoroethylene (PTFE, Teflon® as a bellows material for the transfer of sulfuric acid. We also carried out a CFD analysis of the design. The CFD results indicated that the maximum applicable temperature of PTFE is about 533 K (260 °C, even though its melting point is around 600 K. This result implies that the PTFE is a potential material for the sulfuric acid transfer system. The CFD simulations also confirmed that the sulfuric acid transfer system was designed properly for this particular investigation.

  16. Augmenting Sulfur Metabolism and Herbivore Defense in Arabidopsis by Bacterial Volatile Signaling

    Directory of Open Access Journals (Sweden)

    Mina eAziz

    2016-04-01

    Full Text Available Sulfur is an element necessary for the life cycle of higher plants. Its assimilation and reduction into essential biomolecules are pivotal factors determining a plant’s growth and vigor as well as resistance to environmental stress. While certain soil microbes can enhance ion solubility via chelating agents or oxidation, microbial regulation of plant-sulfur assimilation has not been reported. With an increasing understanding that soil microbes can activate growth and stress tolerance in plants via chemical signaling, the question arises as to whether such beneficial bacteria also regulate sulfur assimilation. Here we report a previously unidentified mechanism by which the growth-promoting rhizobacterium Bacillus amyloliquefaciens (GB03 transcriptionally activates genes responsible for sulfur assimilation, increasing sulfur uptake and accumulation in Arabidopsis. Transcripts encoding for sulfur-rich aliphatic and indolic glucosinolates are also GB03 induced. As a result, GB03-exposed plants with elevated glucosinolates exhibit greater protection against the generalist herbivore, Spodoptera exigua (beet armyworm. In contrast, a previously-characterized glucosinolate mutant compromised in the production of both aliphatic and indolic glucosinolates is also compromised in terms of GB03-induced protection against insect herbivory. As with in vitro studies, soil-grown plants show enhanced glucosinolate accumulation and protection against beet armyworm feeding with GB03 exposure. These results demonstrate the potential of microbes to enhance plant sulfur assimilation and emphasize the sophisticated integration of microbial signaling in plant defense.

  17. 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

  18. Novel hierarchically porous carbon materials obtained from natural biopolymer as host matrixes for lithium-sulfur battery applications.

    Science.gov (United States)

    Zhang, Bin; Xiao, Min; Wang, Shuanjin; Han, Dongmei; Song, Shuqin; Chen, Guohua; Meng, Yuezhong

    2014-08-13

    Novel hierarchically porous carbon materials with very high surface areas, large pore volumes and high electron conductivities were prepared from silk cocoon by carbonization with KOH activation. The prepared novel porous carbon-encapsulated sulfur composites were fabricated by a simple melting process and used as cathodes for lithium sulfur batteries. Because of the large surface area and hierarchically porous structure of the carbon material, soluble polysulfide intermediates can be trapped within the cathode and the volume expansion can be alleviated effectively. Moreover, the electron transport properties of the carbon materials can provide an electron conductive network and promote the utilization rate of sulfur in cathode. The prepared carbon-sulfur composite exhibited a high specific capacity and excellent cycle stability. The results show a high initial discharge capacity of 1443 mAh g(-1) and retain 804 mAh g(-1) after 80 discharge/charge cycles at a rate of 0.5 C. A Coulombic efficiency retained up to 92% after 80 cycles. The prepared hierarchically porous carbon materials were proven to be an effective host matrix for sulfur encapsulation to improve the sulfur utilization rate and restrain the dissolution of polysulfides into lithium-sulfur battery electrolytes.

  19. Systems for hybrid cars

    Science.gov (United States)

    Bitsche, Otmar; Gutmann, Guenter

    Not only sharp competition but also legislation are pushing development of hybrid drive trains. Based on conventional internal combustion engine (ICE) vehicles, these drive trains offer a wide range of benefits from reduced fuel consumption and emission to multifaceted performance improvements. Hybrid electric drive trains may also facilitate the introduction of fuel cells (FC). The battery is the key component for all hybrid drive trains, as it dominates cost and performance issues. The selection of the right battery technology for the specific automotive application is an important task with an impact on costs of development and use. Safety, power, and high cycle life are a must for all hybrid applications. The greatest pressure to reduce cost is in soft hybrids, where lead-acid embedded in a considerate management presents the cheapest solution, with a considerable improvement in performance needed. From mild to full hybridization, an improvement in specific power makes higher costs more acceptable, provided that the battery's service life is equivalent to the vehicle's lifetime. Today, this is proven for the nickel-metal hydride system. Lithium ion batteries, which make use of a multiple safety concept, and with some development anticipated, provide even better prospects in terms of performance and costs. Also, their scalability permits their application in battery electric vehicles—the basis for better performance and enhanced user acceptance. Development targets for the batteries are discussed with a focus on system aspects such as electrical and thermal management and safety.

  20. Stable graphene-polyoxometalate nanomaterials for application in hybrid supercapacitors.

    Science.gov (United States)

    Suárez-Guevara, Jullieth; Ruiz, Vanesa; Gómez-Romero, Pedro

    2014-10-14

    We report the synthesis of hybrid supercapacitor electrodes by a novel reduction of GO with simultaneous incorporation of polyoxometalate. These hybrids show a 30% increase in specific capacitance and excellent stability after 10,000 cycles.

  1. Room-Temperature, Ambient-Pressure Chemical Synthesis of Amine-Functionalized Hierarchical Carbon-Sulfur Composites for Lithium-Sulfur Battery Cathodes.

    Science.gov (United States)

    Chae, Changju; Kim, Jinmin; Kim, Ju Young; Ji, Seulgi; Lee, Sun Sook; Kang, Yongku; Choi, Youngmin; Suk, Jungdon; Jeong, Sunho

    2018-02-07

    Recently, the achievement of newly designed carbon-sulfur composite materials has attracted a tremendous amount of attention as high-performance cathode materials for lithium-sulfur batteries. To date, sulfur materials have been generally synthesized by a sublimation technique in sealed containers. This is a well-developed technique for the synthesizing of well-ordered sulfur materials, but it is limited when used to scale up synthetic procedures for practical applications. In this study, we suggest an easily scalable, room-temperature/ambient-pressure chemical pathway for the synthesis of highly functioning cathode materials using electrostatically assembled, amine-terminated carbon materials. It is demonstrated that stable cycling performance outcomes are achievable with a capacity of 730 mAhg -1 at a current density of 1 C with good cycling stability by a virtue of the characteristic chemical/physical properties (a high conductivity for efficient charge conduction and the presence of a number of amine groups that can interact with sulfur atoms during electrochemical reactions) of composite materials. The critical roles of conductive carbon moieties and amine functional groups inside composite materials are clarified with combinatorial analyses by X-ray photoelectron spectroscopy, cyclic voltammetry, and electrochemical impedance spectroscopy.

  2. 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 .

  3. 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.)

  4. Powering Lithium-Sulfur Battery Performance by Propelling Polysulfide Redox at Sulfiphilic Hosts.

    Science.gov (United States)

    Yuan, Zhe; Peng, Hong-Jie; Hou, Ting-Zheng; Huang, Jia-Qi; Chen, Cheng-Meng; Wang, Dai-Wei; Cheng, Xin-Bing; Wei, Fei; Zhang, Qiang

    2016-01-13

    Lithium-sulfur (Li-S) battery system is endowed with tremendous energy density, resulting from the complex sulfur electrochemistry involving multielectron redox reactions and phase transformations. Originated from the slow redox kinetics of polysulfide intermediates, the flood of polysulfides in the batteries during cycling induced low sulfur utilization, severe polarization, low energy efficiency, deteriorated polysulfide shuttle, and short cycling life. Herein, sulfiphilic cobalt disulfide (CoS2) was incorporated into carbon/sulfur cathodes, introducing strong interaction between lithium polysulfides and CoS2 under working conditions. The interfaces between CoS2 and electrolyte served as strong adsorption and activation sites for polar polysulfides and therefore accelerated redox reactions of polysulfides. The high polysulfide reactivity not only guaranteed effective polarization mitigation and promoted energy efficiency by 10% but also promised high discharge capacity and stable cycling performance during 2000 cycles. A slow capacity decay rate of 0.034%/cycle at 2.0 C and a high initial capacity of 1368 mAh g(-1) at 0.5 C were achieved. Since the propelling redox reaction is not limited to Li-S system, we foresee the reported strategy herein can be applied in other high-power devices through the systems with controllable redox reactions.

  5. Electric vehicle life cycle cost analysis : final research project report.

    Science.gov (United States)

    2017-02-01

    This project compared total life cycle costs of battery electric vehicles (BEV), plug-in hybrid electric vehicles (PHEV), hybrid electric vehicles (HEV), and vehicles with internal combustion engines (ICE). The analysis considered capital and operati...

  6. Hollow Carbon Nanofiber-Encapsulated Sulfur Cathodes for High Specific Capacity Rechargeable Lithium Batteries

    KAUST Repository

    Zheng, Guangyuan

    2011-10-12

    Sulfur has a high specific capacity of 1673 mAh/g as lithium battery cathodes, but its rapid capacity fading due to polysulfides dissolution presents a significant challenge for practical applications. Here we report a hollow carbon nanofiber-encapsulated sulfur cathode for effective trapping of polysulfides and demonstrate experimentally high specific capacity and excellent electrochemical cycling of the cells. The hollow carbon nanofiber arrays were fabricated using anodic aluminum oxide (AAO) templates, through thermal carbonization of polystyrene. The AAO template also facilitates sulfur infusion into the hollow fibers and prevents sulfur from coating onto the exterior carbon wall. The high aspect ratio of the carbon nanofibers provides an ideal structure for trapping polysulfides, and the thin carbon wall allows rapid transport of lithium ions. The small dimension of these nanofibers provides a large surface area per unit mass for Li2S deposition during cycling and reduces pulverization of electrode materials due to volumetric expansion. A high specific capacity of about 730 mAh/g was observed at C/5 rate after 150 cycles of charge/discharge. The introduction of LiNO3 additive to the electrolyte was shown to improve the Coulombic efficiency to over 99% at C/5. The results show that the hollow carbon nanofiber-encapsulated sulfur structure could be a promising cathode design for rechargeable Li/S batteries with high specific energy. © 2011 American Chemical Society.

  7. Sulfur isotopes as a tracer for biogenic sulfate reduction in natural environments: A link between modern and ancient ecosystems. Geologica Ultraiectina (316)

    NARCIS (Netherlands)

    Stam, M.C.

    2010-01-01

    Sulfur isotopes have been widely used to trace the activity of sulfate reducing prokaryotes in modern and ancient geochemical settings and to estimate the role of this microbial metabolism in global sulfur cycling. Extensive pure culture data provide detailed insight into cellular mechanisms

  8. Performance of a hybrid chemical/mechanical heat pump

    Science.gov (United States)

    Silvestri, John J.; Scaringe, Robert P.; Grzyll, Lawrence R.

    1990-01-01

    The authors present the design and preliminary results of the performance of a hybrid chemical/mechanical, low-lift (20 C) heat pump. Studies have indicated that this heat pump has several advantages over the traditional single fluid vapor compression (reverse Rankine) heat pump. Included in these benefits are: 1) increased COPc due to the approximation of the cycle to the Lorenz cycle and due to the availability of the heat of solution, along with the heat of vaporization, to provide cooling; and 2) ease of variation in system cooling capacity by changing the fluid composition. The system performance is predicted for a variety of refrigerant-absorbent pairs. Cooling capacity is determined for systems operating with ammonia as the refrigerant and lithium nitrate and sodium thiocyanate as the absorbents and also with water as the refrigerant and magnesium chloride, potassium hydroxide, lithium bromide, sodium hydroxide, and sulfuric acid as the absorbents. Early indications have shown that the systems operating with water as the refrigerant operate at 2-4 times the capacity of the ammonia-refrigerant-based systems. Using existing working fluids in the proposed innovative design, a coefficient-of-performance improvement of 21 percent is possible when compared to the best vapor compression systems analyzed.

  9. Extension of a reactive distillation process design methodology: application to the hydrogen production through the Iodine-Sulfur thermochemical cycle; Generalisation d'une approche de conception de procedes de distillation reactive: application a la production d'hydrogene par le cycle thermochimique I-S

    Energy Technology Data Exchange (ETDEWEB)

    Belaissaoui, B

    2006-02-15

    Reactive distillation is a promising way to improve classical processes. This interest has been comforted by numerous successful applications involving reactive systems in liquid phase but never in vapour phase. In this context, general design tools have been developed for the analysis of reactive distillation processes whatever the reactive phase. A general model for open condensation and evaporation of vapour or liquid reactive systems in chemical equilibrium has been written and applied to extend the feasibility analysis, synthesis and design methods of the sequential design methodology of R. Thery (2002). The extended design methodology is applied to the industrial production of hydrogen through the iodine-sulphur thermochemical cycle by vapour phase reactive distillation. A column configuration is proposed with better performance formerly published configuration. (author)

  10. 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)

  11. 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

  12. Sulfur and Moisture Effects on Alumina Scale and TBC Spallation

    Science.gov (United States)

    Smialek, James L.

    2007-01-01

    It has been well established that a few ppmw sulfur impurity may segregate to the interface of thermally grown alumina scales and the underlying substrate, resulting in bond degradation and premature spallation. This has been shown for NiAl and NiCrAl-based alloys, bare single crystal superalloys, or coated superalloys. The role of reactive elements (especially Y) has been to getter the sulfur in the bulk and preclude interfacial segregation. Pt additions are also very beneficial, however a similar thermodynamic explanation does not apply. The purpose of the present discussion is to highlight some observations of these effects on Rene'142, Rene'N5, PWA1480, and PWA1484. For PWA1480, we have mapped cyclic oxidation and spallation in terms of potential sulfur interfacial layers and found that a cumulative amount of about one monolayer is sufficient to degrade long term adhesion. Depending on substrate thickness, optimum performance occurs if sulfur is reduced below about 0.2-0.5 ppmw. This is accomplished in the laboratory by hydrogen annealing or commercially by melt-fluxing. Excellent 1150 C cyclic oxidation is thus demonstrated for desulfurized Rene'142, Rene'N5, and PWA1484. Alternatively, a series of N5 alloys provided by GE-AE have shown that as little as 15 ppmw of Y dopant was effective in providin