WorldWideScience

Sample records for regenerative sulfur removal

  1. Modeling of a Large-Scale High Temperature Regenerative Sulfur Removal Process

    DEFF Research Database (Denmark)

    Konttinen, Jukka T.; Johnsson, Jan Erik

    1999-01-01

    model that does not account for bed hydrodynamics. The pilot-scale test run results, obtained in the test runs of the sulfur removal process with real coal gasifier gas, have been used for parameter estimation. The validity of the reactor model for commercial-scale design applications is discussed.......Regenerable mixed metal oxide sorbents are prime candidates for the removal of hydrogen sulfide from hot gasifier gas in the simplified integrated gasification combined cycle (IGCC) process. As part of the regenerative sulfur removal process development, reactor models are needed for scale......-up. Steady-state kinetic reactor models are needed for reactor sizing, and dynamic models can be used for process control design and operator training. The regenerative sulfur removal process to be studied in this paper consists of two side-by-side fluidized bed reactors operating at temperatures of 400...

  2. 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)

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

    Science.gov (United States)

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

    2018-04-01

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

  5. 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.

  6. 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

  7. Process for removal of sulfur oxides from hot gases

    International Nuclear Information System (INIS)

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

    1984-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-02-15

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

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

    International Nuclear Information System (INIS)

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

    1995-01-01

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

  10. Process for removal of sulfur compounds from fuel gases

    Science.gov (United States)

    Moore, Raymond H.; Stegen, Gary E.

    1978-01-01

    Fuel gases such as those produced in the gasification of coal are stripped of sulfur compounds and particulate matter by contact with molten metal salt. The fuel gas and salt are intimately mixed by passage through a venturi or other constriction in which the fuel gas entrains the molten salt as dispersed droplets to a gas-liquid separator. The separated molten salt is divided into a major and a minor flow portion with the minor flow portion passing on to a regenerator in which it is contacted with steam and carbon dioxide as strip gas to remove sulfur compounds. The strip gas is further processed to recover sulfur. The depleted, minor flow portion of salt is passed again into contact with the fuel gas for further sulfur removal from the gas. The sulfur depleted, fuel gas then flows through a solid absorbent for removal of salt droplets. The minor flow portion of the molten salt is then recombined with the major flow portion for feed to the venturi.

  11. Thermal dynamic analysis of sulfur removal from coal by electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Li, D.; Gao, J.; Meng, F. [Qinghua University, Beijing (China). Dept. of Thermal Engineering

    2002-06-01

    The electrolytic reactions about sulfur removal from coal were studied by using chemical thermal dynamic analysis. According to the thermodynamical data, the Gibbs free energy value of the electrolytic reactions of pyritic and organic sulfur removal from coal is higher than zero. So, these electrolytic reactions are not spontaneous chemical reactions. In order to carry out desulfurisation by electrolysis, a certain voltage is necessary and important. Because theoretic decomposition voltage of pyrite and some parts of organic sulfur model compound is not very high, electrolysis reactions are easily to be carried out by using electrolysis technology. Mn ion and Fe ion are added into electrolysis solutions to accelerate the desulfurisation reaction. The electrolytic decomposition of coal is discussed. Because the theoretical decomposition voltage of some organic model compound is not high, the coal decomposition might happen. 17 refs., 4 tabs.

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

    Science.gov (United States)

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

    1991-01-01

    The present disclosure relates to improved processes for treating hot sulfur-containing flue gas to remove sulfur therefrom. Processes in accordance with the present invention include preparing an aqueous slurry composed of a calcium alkali source and a source of reactive silica and/or alumina, heating the slurry to above-ambient temperatures for a period of time in order to facilitate the formation of sulfur-absorbing calcium silicates or aluminates, and treating the gas with the heat-treated slurry components. Examples disclosed herein demonstrate the utility of these processes in achieving improved sulfur-absorbing capabilities. Additionally, disclosure is provided which illustrates preferred configurations for employing the present processes both as a dry sorbent injection and for use in conjunction with a spray dryer and/or bagfilter. Retrofit application to existing systems is also addressed.

  13. Steam regenerative removal of hydrogen sulfide from hot syngas by a novel tin oxide and yttrium oxide sorbent

    International Nuclear Information System (INIS)

    Yang, Yi; Shi, Yixiang; Cai, Ningsheng

    2017-01-01

    A novel H 2 S sorbent based on SnO 2 and Y 2 O 3 is developed by a co-precipitation method for steam regenerative removal of H 2 S from hot syngas at moderate temperatures (400–500 °C). SnO 2 -Y 2 O 3 sorbent is stable in a reducing atmosphere (i.e. 500 °C, 50% H 2 ) and achieves a 99.9% H 2 S removal during successive desulfurization and regeneration cycles. The addition of yttrium to SnO 2 decreases the reduction property of SnO 2 and no metallic Sn exists in the reducing atmosphere due to the formation of a pyrochlore-type compound, Y 2 Sn 2 O 7 . The SnO 2 -Y 2 O 3 sorbent has a desulfurization performance deterioration with the increasing calcination temperature. The newly developed SnO 2 -Y 2 O 3 sorbent can be regenerated by steam at 500 °C. In the eight successive desulfurization and regeneration cycles, SnO 2 -Y 2 O 3 sorbent has a cyclic breakthrough sulfur capacity of 9 mg/g without significant sulfur capacity loss. - Highlights: • Reversible warm gas H 2 S clean up. • Suppressing SnO 2 reduction by formation of Sn 2 Y 2 O 7 . • Sn2Y-700 steam regeneration and cycling characterization.

  14. Reduction of produced elementary sulfur in denitrifying sulfide removal process.

    Science.gov (United States)

    Zhou, Xu; Liu, Lihong; Chen, Chuan; Ren, Nanqi; Wang, Aijie; Lee, Duu-Jong

    2011-05-01

    Denitrifying sulfide removal (DSR) processes simultaneously convert sulfide, nitrate, and chemical oxygen demand from industrial wastewater into elemental sulfur, dinitrogen gas, and carbon dioxide, respectively. The failure of a DSR process is signaled by high concentrations of sulfide in reactor effluent. Conventionally, DSR reactor failure is blamed for overcompetition for heterotroph to autotroph communities. This study indicates that the elementary sulfur produced by oxidizing sulfide that is a recoverable resource from sulfide-laden wastewaters can be reduced back to sulfide by sulfur-reducing Methanobacterium sp. The Methanobacterium sp. was stimulated with excess organic carbon (acetate) when nitrite was completely consumed by heterotrophic denitrifiers. Adjusting hydraulic retention time of a DSR reactor when nitrite is completely consumed provides an additional control variable for maximizing DSR performance.

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

    Science.gov (United States)

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

    1999-01-01

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

  16. Assessment of ASME code examinations on regenerative, letdown and residual heat removal heat exchangers

    International Nuclear Information System (INIS)

    Gosselin, Stephen R.; Cumblidge, Stephen E.; Anderson, Michael T.; Simonen, Fredric A.; Tinsley, G A.; Lydell, B.; Doctor, Steven R.

    2005-01-01

    Inservice inspection requirements for pressure retaining welds in the regenerative, letdown, and residual heat removal heat exchangers are prescribed in Section XI Articles IWB and IWC of the ASME Boiler and Pressure Vessel Code. Accordingly, volumetric and/or surface examinations are performed on heat exchanger shell, head, nozzle-to-head, and nozzle-to-shell welds. Inspection difficulties associated with the implementation of these Code-required examinations have forced operating nuclear power plants to seek relief from the U.S. Nuclear Regulatory Commission. The nature of these relief requests are generally concerned with metallurgical, geometry, accessibility, and radiation burden. Over 60% of licensee requests to the NRC identify significant radiation exposure burden as the principle reason for relief from the ASME Code examinations on regenerative heat exchangers. For the residual heat removal heat exchangers, 90% of the relief requests are associated with geometry and accessibility concerns. Pacific Northwest National Laboratory was funded by the NRC Office of Nuclear Regulatory Research to review current practice with regard to volumetric and/or surface examinations of shell welds of letdown heat exchangers regenerative heat exchangers and residual (decay) heat removal heat exchangers Design, operating, common preventative maintenance practices, and potential degradation mechanisms are reviewed. A detailed survey of domestic and international PWR-specific operating experience was performed to identify pressure boundary failures (or lack of failures) in each heat exchanger type and NSSS design. The service data survey was based on the PIPExp- database and covers PWR plants worldwide for the period 1970-2004. Finally a risk assessment of the current ASME Code inspection requirements for residual heat removal, letdown, and regenerative heat exchangers is performed. The results are then reviewed to discuss the examinations relative to plant safety and

  17. Removal of sulfur and nitrogen containing pollutants from discharge gases

    Energy Technology Data Exchange (ETDEWEB)

    Joubert, James I. (Pittsburgh, PA)

    1986-01-01

    Oxides of sulfur and of nitrogen are removed from waste gases by reaction with an unsupported copper oxide powder to form copper sulfate. The resulting copper sulfate is dissolved in water to effect separation from insoluble mineral ash and dried to form solid copper sulfate pentahydrate. This solid sulfate is thermally decomposed to finely divided copper oxide powder with high specific surface area. The copper oxide powder is recycled into contact with the waste gases requiring cleanup. A reducing gas can be introduced to convert the oxide of nitrogen pollutants to nitrogen.

  18. Removal of sulfur and nitrogen containing pollutants from discharge gases

    Energy Technology Data Exchange (ETDEWEB)

    Joubert, J.I.

    1985-02-08

    Oxides of sulfur and of nitrogen are removed from waste gases by reaction with an unsupported copper oxide powder to form copper sulfate. The resulting copper sulfate is dissolved in water to effect separation from insoluble mineral ash and dried to form solid copper sulfate pentahydrate. This solid sulfate is thermally decomposed to finely divided copper oxide powder with high specific surface area. The copper oxide powder is recycled into contact with the waste gases requiring cleanup. A reducing gas can be introduced to convert the oxide of nitrogen pollutants to nitrogen.

  19. Photoresist removal using gaseous sulfur trioxide cleaning technology

    Science.gov (United States)

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

    1999-06-01

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

  20. Process and system for removing sulfur from sulfur-containing gaseous streams

    Science.gov (United States)

    Basu, Arunabha; Meyer, Howard S.; Lynn, Scott; Leppin, Dennis; Wangerow, James R.

    2012-08-14

    A multi-stage UCSRP process and system for removal of sulfur from a gaseous stream in which the gaseous stream, which contains a first amount of H.sub.2S, is provided to a first stage UCSRP reactor vessel operating in an excess SO.sub.2 mode at a first amount of SO.sub.2, producing an effluent gas having a reduced amount of SO.sub.2, and in which the effluent gas is provided to a second stage UCSRP reactor vessel operating in an excess H.sub.2S mode, producing a product gas having an amount of H.sub.2S less than said first amount of H.sub.2S.

  1. Characteristics of activated carbon remove sulfur particles against smog.

    Science.gov (United States)

    Ge, Shengbo; Liu, Zhenling; Furuta, Yuzo; Peng, Wanxi

    2017-09-01

    Sulfur particles, which could cause diseases, were the main powder of smog. And activated carbon had the very adsorption characteristics. Therefore, five sulfur particles were adsorbed by activated carbon and were analyzed by FT-IR. The optimal adsorption time were 120 min of Na 2 SO 3 , 120 min of Na 2 S 2 O 8 , 120 min of Na 2 SO 4 , 120 min of Fe 2 (SO 4 ) 3 and 120 min of S. FT-IR spectra showed that activated carbon had the eight characteristic absorption of S-S stretch, H 2 O stretch, O-H stretch, -C-H stretch, conjugated C 000000000000 000000000000 000000000000 111111111111 000000000000 111111111111 000000000000 000000000000 000000000000 O stretch or CC stretch, CH 2 bend, C-O stretch and acetylenic C-H bend vibrations at 3850 cm -1 , 3740 cm -1 , 3430 cm -1 , 2920 cm -1 , 1630 cm -1 , 1390 cm -1 , 1110 cm -1 and 600 cm -1 , respectively. For Na 2 SO 3 , the peaks at 2920 cm -1 , 1630 cm -1 , 1390 cm -1 and 1110 cm -1 achieved the maximum at 20 min. For Na 2 S 2 O 8 , the peaks at 3850 cm -1 , 3740 cm -1 and 2920 cm -1 achieved the maximum at 60 min. The peaks at 1390 cm -1 , 1110 cm -1 and 600 cm -1 achieved the maximum at 40 min. For Na 2 SO 4 , the peaks at 3430 cm -1 , 2920 cm -1 , 1630 cm -1 , 1390 cm -1 , 1110 cm -1 and 600 cm -1 achieved the maximum at 60 min. For Fe 2 (SO 4 ) 3 , the peaks at 1390 cm -1 , 1110 cm -1 and 600 cm -1 achieved the maximum at 20 min. For S, the peaks at 1630 cm -1 , 1390 cm -1 and 600 cm -1 achieved the maximum at 120 min. It provided that activated carbon could remove sulfur particles from smog air to restrain many anaphylactic diseases.

  2. Simultaneous removal of nitrogen oxides and sulfur oxides from combustion gases

    Science.gov (United States)

    Clay, David T.; Lynn, Scott

    1976-10-19

    A process for the simultaneous removal of sulfur oxides and nitrogen oxides from power plant stack gases comprising contacting the stack gases with a supported iron oxide catalyst/absorbent in the presence of sufficient reducing agent selected from the group consisting of carbon monoxide, hydrogen, and mixtures thereof, to provide a net reducing atmosphere in the SO.sub.x /NO.sub.x removal zone. The sulfur oxides are removed by absorption substantially as iron sulfide, and nitrogen oxides are removed by catalytic reduction to nitrogen and ammonia. The spent iron oxide catalyst/absorbent is regenerated by oxidation and is recycled to the contacting zone. Sulfur dioxide is also produced during regeneration and can be utilized in the production of sulfuric acid and/or sulfur.

  3. Nitrate removal from aquaculture effluents using woodchip bioreactors improved by adding sulfur granules and crushed seashells

    DEFF Research Database (Denmark)

    von Ahnen, Mathis; Pedersen, Per Bovbjerg; Dalsgaard, Johanne

    2018-01-01

    This study examined the effects on nitrate removal when adding sulfur granules and crushed seashells to a woodchip bioreactor treating aquaculture effluents. Using a central composite design, the two components were added at three levels (0.000, 0.125 and 0.250 m3/m3 bioreactor volume) to 13......, the inclusion of crushed seashells together with sulfur granules helped to maintain the pH above 7.4 and prevent a production (i.e., release) of nitrite. According to the modeled response surfaces, a sulfur granule:crushed seashell:woodchip mixture ratio containing about 0.2 m3 sulfur granules and 0.1 m3...... crushed seashells per m3 reactor volume would give the best results with respect to high N removal and minimal nitrite release. In conclusion, the study showed that N removal in woodchip bioreactors may be improved by adding sulfur granules and seashells, contributing to the optimization of woodchip...

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

    Science.gov (United States)

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

    2009-08-01

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

  5. Adsorption properties of regenerative materials for removal of low concentration of toluene.

    Science.gov (United States)

    Xie, Zhen-Zhen; Wang, Lin; Cheng, Ge; Shi, Lei; Zhang, Yi-Bo

    2016-12-01

    A specific type of material, activated carbon fiber (ACF), was modified by SiO 2 , and the final products ACF-x were obtained as ACF-12.5, ACF-20, ACF-40, and ACF-80 according to different dosages of tetraethoxysilane (TEOS). The modified material on the ACF surface had a significant and smooth cover layer with low content of silica from scanning electron microscope (SEM) image. The modified ACF-x showed the stronger hydrophobicity, thermal stability, and adsorption capacity, which had almost no effect in the presence of water vapor and no destruction in multiple cycles. ACF-20 was proven as the most efficient adsorbent in humid conditions. The dual-function system composed of the regenerative adsorbents and the combustion catalyst would be efficient in consecutive toluene adsorption/oxidation cycles, in which the combustion catalyst was prepared by the displacement reaction of H 2 PtCl 6 with foam Ni. Therefore, the adsorption/catalytic oxidation could be a promising technique in the indoor air purification, especially in the case of very low volatile organic compound (VOC; toluene) concentration levels. Exploring highly effective adsorptive materials with less expensive costs becomes an urgent issue in the indoor air protection. ACF-20 modified by SiO 2 with Pt/Ni catalysts shows stronger hydrophobicity, thermal stability, and adsorption capacity. This dual-function system composed of the regenerative materials and the combustion catalyst would be a promising technique in the indoor air purification, especially in the case of removal of very low concentration of toluene.

  6. Adsorptive removal of organics from aqueous phase by acid-activated coal fly ash: preparation, adsorption, and Fenton regenerative valorization of "spent" adsorbent.

    Science.gov (United States)

    Wang, Nannan; Hao, Linlin; Chen, Jiaqing; Zhao, Qiang; Xu, Han

    2018-05-01

    Raw coal fly ash was activated to an adsorbent by sulfuric acid impregnation. The activation condition, the adsorption capacity, and the regenerative valorization of the adsorbent were studied. The results show that the optimal preparation conditions of the adsorbent are [H 2 SO 4 ] = 1 mol L -1 , activation time = 30 min, the ratio of coal fly ash to acid = 1:20 (g:mL), calcination temperature = 100 °C. The adsorption of p-nitrophenol on the adsorbent accords with the pseudo-second-order kinetic equation and the adsorption rate constant is 0.089 g mg -1  min -1 . The adsorption on this adsorbent can be considered enough after 35 min, when the corresponding adsorption capacity is 1.07 mg g -1 (85.6% of p-nitrophenol removal). Compared with raw coal fly ash, the adsorbent has a stable adsorption performance at low pH range (pH = 1-6) and the adsorption of p-nitrophenol is an exothermic process. Ninety minutes is required for the regenerative valorization of saturated adsorbent by Fenton process. The regenerative valorization for this saturated adsorbent can reach 89% under the optimal proposed conditions (30 °C, pH = 3, [H 2 O 2 ] = 5.0 mmol L -1 , [Fe 2+ ] = 5.5 mmol L -1 ). Within 15 experimental runs, the adsorbent has a better and better stability with the increase of experimental runs. Finally, the mechanism of activating coal fly ash is proposed, being verified by the results of the SEM and BET test.

  7. 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.

  8. Laboratory simulated slipstream testing of novel sulfur removal processes for gasification application

    International Nuclear Information System (INIS)

    Schmidt, Roland; Tsang, Albert; Cross, Joe; Summers, Clinton; Kornosky, Bob

    2008-01-01

    The Wabash River Integrated Methanol and Power Production from Clean Coal Technologies (IMPPCCT) project is investigating an Early Entrance Coproduction Plant (EECP) concept to evaluate integrated electrical power generation and methanol production from coal and other carbonaceous feedstocks. Research, development and testing (RD and T) that is currently being conducted under the project is evaluating cost effective process systems for removing contaminants, particularly sulfur species, from the generated gas which contains mainly synthesis gas (syngas), CO 2 and steam at concentrations acceptable for the methanol synthesis catalyst. The RD and T includes laboratory testing followed by bench-scale and field testing at the SG Solutions Gasification Plant located in West Terre Haute, Indiana. Actual synthesis gas produced by the plant was utilized at system pressure and temperature for bench-scale field testing. ConocoPhillips Company (COP) developed a sulfur removal technology based on a novel, regenerable sorbent - S Zorb trademark - to remove sulfur contaminants from gasoline at high temperatures. The sorbent was evaluated for its sulfur removal performance from the generated syngas especially in the presence of other components such as water and CO 2 which often cause sorbent performance to decline over time. This publication also evaluates the performance of a regenerable activated carbon system developed by Nucon International, Inc. in polishing industrial gas stream by removing sulfur species to parts-per-billion (ppb) levels. (author)

  9. Removal and recovery of nitrogen and sulfur oxides from gaseous mixtures containing them

    International Nuclear Information System (INIS)

    Cooper, H.B.H.

    1984-01-01

    A cyclic process for removing lower valence nitrogen oxides from gaseous mixtures includes treating the mixtures with an aqueous media including alkali metal carbonate and alkali metal bicarbonate and a preoxygen oxidant to form higher valence nitrogen oxides and to capture these oxides as alkali metal salts, expecially nitrites and nitrates, in a carbonate/bicarbonate-containing product aqueous media. Highly selective recovery of nitrates in high purity and yield may then follow, as by crystallization, with the carbonate and bicarbonate alkali metal salts strongly increasing the selectivity and yield of nitrates. The product nitrites are converted to nitrates by oxidation after lowering the product aqueous media pH to below about 9. A cyclic process for removing sulfur oxides from gas mixtures includes treating these mixtures includes treating these mixtures with aqueous media including alkali metal carbonate and alkali metal bicarbonate where the ratio of alkali metal to sulfur dioxide is not less than 2. The sulfur values may be recovered from the resulting carbonate/bicarbonate/-sulfite containing product aqueous media as alkali metal sulfate or sulfite salts which are removed by crystallization from the carbonate-containing product aqueous media. As with the nitrates, the carbonate/bicarbonate system strongly increases yield of sulfate or sulfite during crystallization. Where the gas mixtures include both sulfur dioxide and lower valence nitrogen oxides, the processes for removing lower valence nitrogen oxides and sulfur dioxide may be combined into a single removal/recovery system, or may be effected in sequence

  10. Method of removing oxides of sulfur and oxides of nitrogen from exhaust gases

    Science.gov (United States)

    Walker, Richard J.

    1986-01-01

    A continuous method is presented for removing both oxides of sulfur and oxides of nitrogen from combustion or exhaust gases with the regeneration of the absorbent. Exhaust gas is cleaned of particulates and HCl by a water scrub prior to contact with a liquid absorbent that includes an aqueous solution of bisulfite and sulfite ions along with a metal chelate, such as, an iron or zinc aminopolycarboxylic acid. Following contact with the combustion gases the spent absorbent is subjected to electrodialysis to transfer bisulfite ions into a sulfuric acid solution while splitting water with hydroxide and hydrogen ion migration to equalize electrical charge. The electrodialysis stack includes alternate layers of anion selective and bipolar membranes. Oxides of nitrogen are removed from the liquid absorbent by air stripping at an elevated temperature and the regenerated liquid absorbent is returned to contact with exhaust gases for removal of sulfur oxides and nitrogen oxides.

  11. FURNACE INJECTION OF ALKALINE SORBENTS FOR SULFURIC ACID REMOVAL

    Energy Technology Data Exchange (ETDEWEB)

    Gary M. Blythe

    2004-01-01

    The objective of this project has been to demonstrate the use of alkaline reagents injected into the furnace of coal-fired boilers as a means of controlling sulfuric acid emissions. The project was co-funded by the U.S. DOE National Energy Technology Laboratory under Cooperative Agreement DE-FC26-99FT40718, along with EPRI, the American Electric Power Company (AEP), FirstEnergy Corporation, the Tennessee Valley Authority, and Carmeuse North America. Sulfuric acid controls are becoming of increased interest for coal-fired power generating units for a number of reasons. In particular, sulfuric acid can cause plant operation problems such as air heater plugging and fouling, back-end corrosion, and plume opacity. These issues will likely be exacerbated with the retrofit of selective catalytic reduction (SCR) for NOX control, as SCR catalysts are known to further oxidize a portion of the flue gas SO{sub 2} to SO{sub 3}. The project tested the effectiveness of furnace injection of four different magnesium-based or dolomitic alkaline sorbents on full-scale utility boilers. These reagents were tested during one- to two-week tests conducted on two FirstEnergy Bruce Mansfield Plant (BMP) units. One of the sorbents tested was a magnesium hydroxide slurry byproduct from a modified Thiosorbic{reg_sign} Lime wet flue gas desulfurization process. The other three sorbents are available commercially and include dolomite, pressure-hydrated dolomitic lime, and commercially available magnesium hydroxide. The dolomite reagent was injected as a dry powder through out-of-service burners. The other three reagents were injected as slurries through air-atomizing nozzles inserted through the front wall of the upper furnace. After completing the four one- to two-week tests, the most promising sorbents were selected for longer-term (approximately 25-day) full-scale tests on two different units. The longer-term tests were conducted to confirm sorbent effectiveness over extended operation on two

  12. Biotransformation and removal of sulfur from dibenzothiophene using improved bio catalytic methods

    International Nuclear Information System (INIS)

    La Rotta, C. E; Mora, A.L; Madero, A; Mogollon, L.I

    1998-01-01

    Three methods for the removal of sulfur from dibenzothiophene were evaluated using bio catalytic processes. The methods were a microbial, an enzymatic and a combined one that involves a previous enzymatic oxidation followed by microbial degradation. The bioconversion was evaluated over the molecular dibenzothiophene model, obtaining higher bioconversion percentages through the combined method. The microorganisms used in this study correspond to several Colombian indigenous strains isolated by direct methods from natural sources, and using a standard strain as positive control. All strains have shown sulfur removal capacity, and organic solvent tolerance. The enzyme used was a hemo protein with peroxidase activity, Cytochrome C, obtained from equine heart

  13. Process for the removal of sulfur oxides and nitrogen oxides from flue gas

    International Nuclear Information System (INIS)

    Elshout, R.V.

    1992-01-01

    This patent describes a continuous process for removing sulfur oxide and nitrogen oxide contaminants from the flue gas generated by industrial power plants and boiler systems burning sulfur containing fossil fuels and for converting these contaminants, respectively, into recovered elemental liquid sulfur and nitrogen ammonia and mixtures thereof. It comprises removing at least a portion of the flue gas generated by a power plant or boiler system upstream of the stack thereof; passing the cooled and scrubbed flue gas through an adsorption system; combining a first portion of the reducing gas stream leaving the adsorbers of the adsorption system during regeneration thereof and containing sulfur oxide and nitrogen oxide contaminants with a hydrogen sulfide rich gas stream at a temperature of about 400 degrees F to about 600 degrees F and passing the combined gas streams through a Claus reactor-condenser system over a catalyst in the reactor section thereof which is suitable for promoting the equilibrium reaction between the hydrogen sulfide and the sulfur dioxide of the combined streams to form elemental sulfur

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

    Science.gov (United States)

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

    2018-04-01

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

  15. Biodesulfurization techniques: Application of selected microorganisms for organic sulfur removal from coals. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Elmore, B.B.

    1993-08-01

    As an alternative to post-combustion desulfurization of coal and pre-combustion desulfurization using physicochemical techniques, the microbial desulfurization of coal may be accomplished through the use of microbial cultures that, in an application of various microbial species, may remove both the pyritic and organic fractions of sulfur found in coal. Organisms have been isolated that readily depyritize coal but often at prohibitively low rates of desulfurization. Microbes have also been isolated that may potentially remove the organic-sulfur fraction present in coal (showing promise when acting on organic sulfur model compounds such as dibenzothiophene). The isolation and study of microorganisms demonstrating a potential for removing organic sulfur from coal has been undertaken in this project. Additionally, the organisms and mechanisms by which coal is microbially depyritized has been investigated. Three cultures were isolated that grew on dibenzothiophene (DBT), a model organic-sulfur compound, as the sole sulfur source. These cultures (UMX3, UMX9, and IGTS8) also grew on coal samples as the sole sulfur source. Numerous techniques for pretreating and ``cotreating`` coal for depyritization were also evaluated for the ability to improve the rate or extent of microbial depyritization. These include prewashing the coal with various solvents and adding surfactants to the culture broth. Using a bituminous coal containing 0.61% (w/w) pyrite washed with organic solvents at low slurry concentrations (2% w/v), the extent of depyritization was increased approximately 25% in two weeks as compared to controls. At slurry concentrations of 20% w/v, a tetrachloroethylene treatment of the coal followed by depyritization with Thiobacillus ferrooxidans increased both the rate and extent of depyritization by approximately 10%.

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  17. Removal of H2S and volatile organic sulfur compounds by silicone membrane extraction

    NARCIS (Netherlands)

    Manconi, I.; Lens, P.N.L.

    2009-01-01

    BACKGROUND: This study explores an alternative process for the abatement and/or desulfurization of H2S and volatile organic sulfur compounds (VOSC) containing waste streams, which employs a silicone-based membrane to simultaneously remove H2S and VOSC. An extractive membrane reactor allows the

  18. A dynamic mathematical model for microbial removal of pyritic sulfur from coal.

    Science.gov (United States)

    Kargi, F; Weissman, J G

    1984-06-01

    A dynamic mathematical model has been developed to describe microbial desulfurization of coal by Thiobacillus ferrooxidans. The model considers adsorption and desorption of cells on coal particles and microbial oxidation of pyritic sulfur on particle surfaces. The influence of certain parameters, such as microbial growth rate constants, adsorption-description constants, pulp density, coal particle size, initial cell and solid phase substrate concentration on the maximum rate of pyritic sulfur removal, have been elucidated. The maximum rate of pyritic sulfur removal was strongly dependent upon the number of attached cells per coal particle. At sufficiently high initial cell concentrations, the surfaces of coal particles are nearly saturated by the cells and the maximum leaching rate is limited either by total external surface area of coal particles or by the concentration of pyritic sulfur in the coal phase. The maximum volumetric rate of pyritic sulfur removal (mg S/h cm(3) mixture) increases with the pulp density of coal and reaches a saturation level at high pulp densities (e.g. 45%). The maximum rate also increases with decreasing particle diameter in a hyperbolic form. Increases in adsorption coefficient or decreases in the desorption coefficient also result in considerable improvements in this rate. The model can be applied to other systems consisting of suspended solid substrate particles in liquid medium with microbial oxidation occurring on the particle surfaces (e.g., bacterial ore leaching). The results obtained from this model are in good agreement with published experimental data on microbial desulfurization of coal and bacterial ore leaching.

  19. 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.

  20. Application of acoustic agglomeration for removing sulfuric acid mist from air stream

    Directory of Open Access Journals (Sweden)

    Asghar Sadighzadeh

    2018-01-01

    Full Text Available The application of acoustic fields at high sound pressure levels (SPLs for removing sulfuric acid mists from the air stream was studied. An acoustic agglomeration chamber was used to conduct the experiments. The studied SPLs ranged from 115 to 165 decibel (dB, with three inlet concentrations of acid mist at 5–10, 15–20, and 25–30 ppm. The air flow rates for conducting experiments were 20, 30, and 40 L min−1. The concentration of sulfuric acid mist was measured using US Environmental Protection Agency Method 8 at inlet and outlet of the chamber. The resonance frequencies for experiments were found to be 852, 1410, and 3530 Hz. The maximum acoustic agglomeration efficiency of 86% was obtained at optimum frequency of 852 Hz. The analysis of variance test revealed significant differences between agglomeration efficiency at three resonance frequencies (p-value < 0.001. The maximum acoustic agglomeration efficiency was obtained at SPL level of 165 dB. High initial concentrations of acid mists and lower air flow rates enhance the acoustic agglomeration of mists. High removal efficiency of acid mists from air stream could be achieved by the application of acoustic agglomeration method with appropriate range of frequencies and SPLs. Keywords: Sulfuric acid, Mist, Acoustic agglomeration, SPL

  1. Removal of sulfur dioxide and formation of sulfate aerosol in Tokyo

    Science.gov (United States)

    Miyakawa, T.; Takegawa, N.; Kondo, Y.

    2007-07-01

    Ground-based in situ measurements of sulfur dioxide (SO2) and submicron sulfate aerosol (SO42-) together with carbon monoxide (CO) were conducted at an urban site in Tokyo, Japan from spring 2003 to winter 2004. The observed concentrations of SO2 were affected dominantly by anthropogenic emissions (for example, manufacturing industries) in source areas, while small fraction of the data (sulfur compounds (SOx = SO2 + SO42-) and the remaining fraction of SOx, which is derived as the ratio of the linear regression slope of the SOx-CO correlation, is used as measures for the formation of SO42- and removal of SOx, respectively. Using these parameters, the average formation efficiency of SO42- (i.e., amount of SO42- produced per SO2 emitted from emission sources) are estimated to be 0.18 and 0.03 in the summer and winter periods, respectively. A simple box model was developed to estimate the lifetime of SOx. The lifetime of SOx for the summer period (26 h) is estimated to be about two times longer than that for the winter period (14 h). The seasonal variations of the remaining fraction of SOx, estimated formation efficiency of SO42-, and lifetime of SOx are likely due to those of the boundary layer height and photochemical activity (i.e., hydroxyl radical). These results provide useful insights into the formation and removal processes of sulfur compounds exported from an urban area.

  2. Mathematical modeling of simultaneous carbon-nitrogen-sulfur removal from industrial wastewater.

    Science.gov (United States)

    Xu, Xi-Jun; Chen, Chuan; Wang, Ai-Jie; Ni, Bing-Jie; Guo, Wan-Qian; Yuan, Ye; Huang, Cong; Zhou, Xu; Wu, Dong-Hai; Lee, Duu-Jong; Ren, Nan-Qi

    2017-01-05

    A mathematical model of carbon, nitrogen and sulfur removal (C-N-S) from industrial wastewater was constructed considering the interactions of sulfate-reducing bacteria (SRB), sulfide-oxidizing bacteria (SOB), nitrate-reducing bacteria (NRB), facultative bacteria (FB), and methane producing archaea (MPA). For the kinetic network, the bioconversion of C-N by heterotrophic denitrifiers (NO 3 - →NO 2 - →N 2 ), and that of C-S by SRB (SO 4 2- →S 2- ) and SOB (S 2- →S 0 ) was proposed and calibrated based on batch experimental data. The model closely predicted the profiles of nitrate, nitrite, sulfate, sulfide, lactate, acetate, methane and oxygen under both anaerobic and micro-aerobic conditions. The best-fit kinetic parameters had small 95% confidence regions with mean values approximately at the center. The model was further validated using independent data sets generated under different operating conditions. This work was the first successful mathematical modeling of simultaneous C-N-S removal from industrial wastewater and more importantly, the proposed model was proven feasible to simulate other relevant processes, such as sulfate-reducing, sulfide-oxidizing process (SR-SO) and denitrifying sulfide removal (DSR) process. The model developed is expected to enhance our ability to predict the treatment of carbon-nitrogen-sulfur contaminated industrial wastewater. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Efficient removal of sulfur hexafluoride (SF6) through reacting with recycled electroplating sludge.

    Science.gov (United States)

    Zhang, Jia; Zhou, Ji Zhi; Liu, Qiang; Qian, Guangren; Xu, Zhi Ping

    2013-06-18

    This paper reports that recycled electroplating sludge is able to efficiently remove greenhouse gas sulfur hexafluoride (SF6). The removal process involves various reactions of SF6 with the recycled sludge. Remarkably, the sludge completely removed SF6 at a capacity of 1.10 mmol/g (SF6/sludge) at 600 °C. More importantly, the evolved gases were SO2, SiF4, and a limited amount of HF, with no toxic SOF4, SO2F2, or SF4 being detected. These generated gases can be readily captured and removed by NaOH solution. The reacted solids were further found to be various metal fluorides, thus revealing that SF6 removal takes place by reacting with various metal oxides and silicate in the sludge. Moreover, the kinetic investigation revealed that the SF6 reaction with the sludge is a first-order chemically controlled process. This research thus demonstrates that the waste electroplating sludge can be potentially used as an effective removal agent for one of the notorious greenhouse gases, SF6.

  4. Manganese-Loaded Activated Carbon for the Removal of Organosulfur Compounds from High-Sulfur Diesel Fuels

    OpenAIRE

    Al-Ghouti, M.A.; Al-Degs, Y.S.

    2014-01-01

    The adsorptive capacity of activated carbon (AC) is significantly enhanced toward weakly interacting organosulfur compounds (OSC) from sulfur-rich diesel fuel. Sulfur compounds are selectively removed from diesel after surface modification by manganese dioxide (MnO2). A selective surface for OSC removal was created by loading MnO2 on the surface; π-complexation between the partially filled d-orbitals of Mn4+ and the S atom is the controlling mechanism for OSC removal. Principal component anal...

  5. Removal of hydrogen sulfide and sulfur dioxide by carbons impregnated with triethylenediamine.

    Science.gov (United States)

    Wu, Li-Chun; Chang, Tsu-Hua; Chung, Ying-Chien

    2007-12-01

    Activated carbon (AC) adsorption has long been considered to be a readily available technology for providing protection against exposure to acutely toxic gases. However, ACs without chemical impregnation have proven to be much less efficient than impregnated ACs in terms of gas removal. The impregnated ACs in current use are usually modified with metalloid impregnation agents (ASC-carbons; copper, chromium, or silver) to simultaneously enhance the chemical and physical properties of the ACs in removing specific poisonous gases. These metalloid agents, however, can cause acute poisoning to both humans and the environment, thereby necessitating the search for organic impregnation agents that present a much lower risk. The aim of the study reported here was to assess AC or ASC-carbon impregnated with triethylenediamine (TEDA) in terms of its adsorption capability for simulated hydrogen sulfide (H2S) and sulfur dioxide (SO2) gases. The investigation was undergone in a properly designed laboratory-scale and industrial fume hood evaluation. Using the system reported here, we obtained a significant adsorption: the removal capability for H2S and SO2 was 375 and 229 mg/g-C, respectively. BET measurements, element analysis, scanning electron microscopy, and energy dispersive spectrometry identified the removal mechanism for TEDA-impregnated AC to be both chemical and physical adsorption. Chemical adsorption and oxidation were the primary means by which TEDA-impregnated ASC-carbons removed the simulated gases.

  6. Study of a combined heterotrophic and sulfur autotrophic denitrification technology for removal of nitrate in water

    International Nuclear Information System (INIS)

    Liu Huijuan; Jiang Wei; Wan Dongjin; Qu Jiuhui

    2009-01-01

    A combined two-step process of heterotrophic denitrification in a fluidized reactor and sulfur autotrophic denitrification processes (CHSAD) was developed for the removal of nitrate in drinking water. In this process, the advantage of high efficiency of heterotrophic denitrification with non-excessive methanol and the advantage of non-pollution of sulfur autotriphic denitrification were integrated in this CHSAD process. And, this CHSAD process had the capacity of pH balance and could control the concentration of SO 4 2- in effluent by adjusting the operation condition. When the influent nitrate was 30 mg NO 3 - -N/L, the reactor could be operated efficiently at the hydraulic retention time (HRT) ranging from 20 to 40 min with C:N ratio (mg CH 3 OH:mg NO 3 - -N) of 2.0 (methanol as carbon source). The nitrate removal was nearly 100% and there was no accumulated nitrite or residual methanol in the effluent. The effluent pH was about 7.5 and the sulfate concentration was lower than 130 mg/L. The maximum volume-loading rate of the reactor was 2.16 kg NO 3 - -N/(m 3 d). The biomass and scanning electron microscopy graphs of biofilm were also analyzed.

  7. Removal of sulfur compounds from diesel using ArF laser and oxygen.

    Science.gov (United States)

    Gondal, M A; Siddiqui, M N; Al-Hooshani, K

    2013-01-01

    A laser-based technique for deep desulfurization of diesel and other hydrocarbon fuels by removal of dimethyldibenzothiophene (DMDBT), a persistent sulfur contaminant in fuel oils has been developed. We report a selective laser excitation of DMDBT in diesel and model compounds such as n-hexane in a reaction chamber under oxygen environment where oxidative reactions can take place. ArF laser emitting at 193 nm was employed for excitation of oxygen and DMDBT, while for process optimization, the laser energy was varied from 50 to 200 mJ/cm(2). The laser-irradiated DMDBT solution under continuous oxygen flow was analyzed by UV absorption spectrometer to determine the photochemical oxidative degradation of DMDBT. In just 5 min of laser irradiation time, almost 95% DMDBT was depleted in a diesel containing 200 ppm of DMDBT. This article provides a new method for the removal of sulfur compounds from diesel by laser based photochemical process.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-10-15

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

  9. Elementary sulfur in effluent from denitrifying sulfide removal process as adsorbent for zinc(II).

    Science.gov (United States)

    Chen, Chuan; Zhou, Xu; Wang, Aijie; Wu, Dong-hai; Liu, Li-hong; Ren, Nanqi; Lee, Duu-Jong

    2012-10-01

    The denitrifying sulfide removal (DSR) process can simultaneously convert sulfide, nitrate and organic compounds into elementary sulfur (S(0)), di-nitrogen gas and carbon dioxide, respectively. However, the S(0) formed in the DSR process are micro-sized colloids with negatively charged surface, making isolation of S(0) colloids from other biological cells and metabolites difficult. This study proposed the use of S(0) in DSR effluent as a novel adsorbent for zinc removal from wastewaters. Batch and continuous tests were conducted for efficient zinc removal with S(0)-containing DSR effluent. At pHremoval rates of zinc(II) were increased with increasing pH. The formed S(0) colloids carried negative charge onto which zinc(II) ions could be adsorbed via electrostatic interactions. The zinc(II) adsorbed S(0) colloids further enhanced coagulation-sedimentation efficiency of suspended solids in DSR effluents. The DSR effluent presents a promising coagulant for zinc(II) containing wastewaters. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Influence of liquid and gas flow rates on sulfuric acid mist removal from air by packed bed tower

    Directory of Open Access Journals (Sweden)

    Jafari Mohammad Javad

    2012-12-01

    Full Text Available Abstract The possible emission of sulfuric acid mists from a laboratory scale, counter-current packed bed tower operated with a caustic scrubbing solution was studied. Acid mists were applied through a local exhaust hood. The emissions from the packed bed tower were monitored in three different categories of gas flow rate as well as three liquid flow rates, while other influencing parameters were kept almost constant. Air sampling and sulfuric acid measurement were carried out iso-kinetically using USEPA method 8. The acid mists were measured by the barium-thorin titration method. According to the results when the gas flow rate increased from 10 L/s to 30 L/s, the average removal efficiency increased significantly (p 3, respectively. L/G of 2–3 was recommended for designing purposes of a packed tower for sulfuric acid mists and vapors removal from contaminated air stream.

  11. Removal of Sulfur from CaF2 Containing Desulfurization Slag Exhausted from Secondary Steelmaking Process by Oxidation

    Science.gov (United States)

    Hiraki, Takehito; Kobayashi, Junichi; Urushibata, Satomi; Matsubae, Kazuyo; Nagasaka, Tetsuya

    2012-08-01

    The oxidation behavior of sulfur in desulfurization slag generated from the secondary steelmaking process with air has been investigated in the temperature range of 973 K to 1373 K (700 °C to 1100 °C). Although a high removal rate of sulfur is not achieved at temperatures lower than 1273 K (1000 °C) because of the formation of CaSO4, most of the sulfur is rapidly removed from slag as SO2 gas in the 1273 K to 1373 K (700 °C to 1100 °C) range. This finding indicates that the desulfurization slag generated from the secondary steelmaking process can be reused as a desulfurized flux through air oxidation, making it possible to reduce significantly the amount of desulfurization slag for disposal.

  12. Catalytic removal of sulfur dioxide from dibenzothiophene sulfone over Mg-Al mixed oxides supported on mesoporous silica.

    Science.gov (United States)

    You, Nansuk; Kim, Min Ji; Jeong, Kwang-Eun; Jeong, Soon-Yong; Park, Young-Kwon; Jeon, Jong-Ki

    2010-05-01

    Dibenzothiophene sulfone (DBTS), one of the products of the oxidative desulfurization of heavy oil, can be removed through extraction as well as by an adsorption process. It is necessary to utilize DBTS in conjunction with catalytic cracking. An object of the present study is to provide an Mg-Al-mesoporous silica catalyst for the removal of sulfur dioxide from DBTS. The characteristics of the Mg-Al-mesoporous silica catalyst were investigated through N2 adsorption, XRD, ICP, and XRF. An Mg-Al-mesoporous silica catalyst formulated in a direct incorporation method showed higher catalytic performance compared to pure MgO during the catalytic removal of sulfur dioxide from DBTS. The higher dispersion of Mg as well as the large surface area of the Mg-Al-mesoporous silica catalyst strongly influenced the catalyst basicity in DBTS cracking.

  13. Cu-based metal–organic framework/activated carbon composites for sulfur compounds removal

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Rui-Hua [State Key Laboratory of Coal Science and Technology, Co-founded by Shanxi Province and the Ministry of Science and Technology, Institute for Chemical Engineering of Coal, Taiyuan University of Technology, West Yingze Street Number 79, Taiyuan 030024 (China); Zhang, Zhen-Rong [Institute of Applied Chemical, Shanxi (China); Fan, Hui-Ling, E-mail: fanhuiling@tyut.edu.cn [State Key Laboratory of Coal Science and Technology, Co-founded by Shanxi Province and the Ministry of Science and Technology, Institute for Chemical Engineering of Coal, Taiyuan University of Technology, West Yingze Street Number 79, Taiyuan 030024 (China); Zhen, Tian [Deparment of Analysis and Service Center Micromertics instrumental Ltd, Shanghai (China); Shangguan, Ju; Mi, Jie [State Key Laboratory of Coal Science and Technology, Co-founded by Shanxi Province and the Ministry of Science and Technology, Institute for Chemical Engineering of Coal, Taiyuan University of Technology, West Yingze Street Number 79, Taiyuan 030024 (China)

    2017-02-01

    Highlights: • Incorporation of AC less than 2% in MOF-199 can increase micropores and BET surface area, as evidenced by N{sub 2} adsorption. • Lewis acid (unsaturated copper) sites could also be increased in the modified MOF-199, as revealed by Py-IR characterization. • Composite with 2% AC showed highest sulfur capacity with 8.46 and 8.53% for H{sub 2}S and CH{sub 3}SCH{sub 3}, respectively. • The adsorption of CH{sub 3}SCH{sub 3} on composite is reversible, physic-adsorption and weak chemisorption were involved. - Abstract: MOF-199 was modified by incorporating activated carbon (AC) during its synthesis under hydrothermal conditions to improve its performance in the removal of hydrogen sulfide (H{sub 2}S) and dimethyl sulfide (CH{sub 3}SCH{sub 3}). A variety of different characterization techniques including X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, nitrogen adsorption/desorption isotherms, scanning electron microscopy (SEM), pyridine adsorption infrared spectroscopy (Py-IR), thermogravimetric- mass spectroscopy (TG-MS) and X-ray photoelectron spectroscopy (XPS) were used to analyze the fresh and exhausted composites. It was found that the composites, which have an amount of AC of less than 2%, had the same morphology as those of pristine MOF-199, but exhibited a more ordered crystallinity structure as well as higher surface area. The composite with 2% AC incorporation showed highest sulfur capacity of 8.46 and 8.53% for H{sub 2}S and CH{sub 3}SCH{sub 3}, respectively, which increased by 51 and 41% compared to that of MOF-199. This improvement was attributed to the formation of more micropores and especially the increased number of unsaturated copper metal sites, as revealed by Py-IR. It is suggested the chemical reaction was apparent during adsorption of H{sub 2}S, which resulted in the formation of CuS and the collapse of the MOF structure. Whereas reversible chemisorption was found for CH{sub 3}SCH{sub 3} adsorption, as

  14. Removal of Sulfur Dioxide from Flue Gas Using the Sludge Sodium Humate

    Directory of Open Access Journals (Sweden)

    Yu Zhao

    2013-01-01

    Full Text Available This study shows the ability of sodium humate from alkaline treatment sludge on removing sulfur dioxide (SO2 in the simulated flue gas. Experiments were conducted to examine the effect of various operating parameters, like the inlet SO2 concentration or temperature or O2, on the SO2 absorption efficiency and desulfurization time in a lab-scale bubbling reactor. The sludge sodium humate in the supernatant after alkaline sludge treatment shows great performance in SO2 absorption, and such efficiency can be maintained above 98% with 100 mL of this absorption solution at 298 K (flue gas rate of 0.12 m3/h. The highest SO2 absorption by 1.63 g SHA-Na is 0.946 mmol in the process, which is translated to 0.037 g SO2 g−1 SHA-Na. The experimental results indicate that the inlet SO2 concentration slightly influences the SO2 absorption efficiency and significantly influences the desulfurization time. The pH of the absorption solution should be above 3.5 in this process in order to make an effective desulfurization. The products of this process were characterized by Fourier transform infrared spectroscopy and X-ray diffraction. It can be seen that the desulfurization products mainly contain sludge humic acid sediment, which can be used as fertilizer components.

  15. Advanced treatment technique for swine wastewater using two agents: Thermally polymerized amorphous silica and hydrated lime for color and phosphorus removal and sulfur for nitrogen removal.

    Science.gov (United States)

    Hasegawa, Teruaki; Kurose, Yohei; Tanaka, Yasuo

    2017-10-01

    The efficacy of advanced treatment of swine wastewater using thermally polymerized, modified amorphous silica and hydrated lime (M-CSH-lime) for color and phosphorus removal and sulfur for nitrogen removal was examined with a demonstration-scale treatment plant. The color removal rate was approximately 78% at M-CSH-lime addition rates of > 0.055 wt/v%. The PO43--P removal rate exceeded 99.9% with > 0.023 wt/v%. pH of the effluent from the M-CSH-lime reactor increased with the addition rate till a maximum value of 12.7, which was effective in disinfection. The recovered M-CSH-lime would be suitable as a phosphorus fertilizer because the total P 2 O 5 content was approximately 10%. The nitrogen oxide (NOx-N) removal rate by sulfur denitrification increased to approximately 80% when the NOx-N loading rate was around 0.1 kg-N/ton-S/day. It was suggested that the combination of the two processes would be effective in the advanced treatment of swine wastewater. © 2017 Japanese Society of Animal Science.

  16. Simultaneous removal of sulfur dioxide and polycyclic aromatic hydrocarbons from incineration flue gas using activated carbon fibers.

    Science.gov (United States)

    Liu, Zhen-Shu; Li, Wen-Kai; Hung, Ming-Jui

    2014-09-01

    Incineration flue gas contains polycyclic aromatic hydrocarbons (PAHs) and sulfur dioxide (SO2). The effects of SO2 concentration (0, 350, 750, and 1000 ppm), reaction temperature (160, 200, and 280 degrees C), and the type of activated carbon fibers (ACFs) on the removal of SO2 and PAHs by ACFs were examined in this study. A fluidized bed incinerator was used to simulate practical incineration flue gas. It was found that the presence of SO2 in the incineration flue gas could drastically decrease removal of PAHs because of competitive adsorption. The effect of rise in the reaction temperature from 160 to 280 degrees C on removal of PAHs was greater than that on SO2 removal at an SO2 concentration of 750 ppm. Among the three ACFs studied, ACF-B, with the highest microporous volume, highest O content, and the tightest structure, was the best adsorbent for removing SO2 and PAHs when these gases coexisted in the incineration flue gas. Implications: Simultaneous adsorption of sulfur dioxide (SO2) and polycyclic aromatic hydrocarbons (PAHs) emitted from incineration flue gas onto activated carbon fibers (ACFs) meant to devise a new technique showed that the presence of SO2 in the incineration flue gas leads to a drastic decrease in removal of PAHs because of competitive adsorption. Reaction temperature had a greater influence on PAHs removal than on SO2 removal. ACF-B, with the highest microporous volume, highest O content, and tightest structure among the three studied ACFs, was found to be the best adsorbent for removing SO2 and PAHs.

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

    Energy Technology Data Exchange (ETDEWEB)

    1977-01-01

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

  18. Use of zeolites for the removal of volatile sulfur compounds from industrial waste gases and from natural gases

    Energy Technology Data Exchange (ETDEWEB)

    Dudzik,; Z,; Bilska, M

    1974-12-01

    The use of zeolites for the removal of sulfur dioxide from industrial waste gases and for the removal of hydrogen sulfide and volatile mercaptans from the natural gas or synthetic gas manufactured from coal is discussed. The effectiveness and cost of zeolite methods are superior to that of other methods. The best sorption properties with respect to sulfur dioxide are observed in faujasites and erionites. The molecular sieve 13X (a sodium form of low-silicon faujasite) is the most effective sorbent of hydrogen sulfide, produced commercially on a large scale. This zeolite is also a very effective catalyst for simultaneous oxygenation of hydrogen sulfide. The reaction with oxygen can begin at temperatures as low as -80/sup 0/C. The effectiveness of zeolite reactors is enhanced by the presence of oxygen in the gas being purified, and is hindered by the presence of water or water vapor. The extraordinary catalytic activity of sodium faujasites is due to free donors, and sulfur and oxygen ion donors at their surface. A zeolite reactor is also economical.

  19. Simultaneous removal of nitrogen oxide/nitrogen dioxide/sulfur dioxide from gas streams by combined plasma scrubbing technology.

    Science.gov (United States)

    Chang, Moo Been; Lee, How Ming; Wu, Feeling; Lai, Chi Ren

    2004-08-01

    Oxides of nitrogen (NOx) [nitrogen oxide (NO) + nitrogen dioxide (NO2)] and sulfur dioxide (SO2) are removed individually in traditional air pollution control technologies. This study proposes a combined plasma scrubbing (CPS) system for simultaneous removal of SO2 and NOx. CPS consists of a dielectric barrier discharge (DBD) and wet scrubbing in series. DBD is used to generate nonthermal plasmas for converting NO to NO2. The water-soluble NO2 then can be removed by wet scrubbing accompanied with SO2 removal. In this work, CPS was tested with simulated exhausts in the laboratory and with diesel-generator exhausts in the field. Experimental results indicate that DBD is very efficient in converting NO to NO2. More than 90% removal of NO, NOx, and SO2 can be simultaneously achieved with CPS. Both sodium sulfide (Na2S) and sodium sulfite (Na2SO3) scrubbing solutions are good for NO2 and SO2 absorption. Energy efficiencies for NOx and SO2 removal are 17 and 18 g/kWh, respectively. The technical feasibility of CPS for simultaneous removal of NO, NO2, and SO2 from gas streams is successfully demonstrated in this study. However, production of carbon monoxide as a side-product (approximately 100 ppm) is found and should be considered.

  20. Combined removal of sulfur compounds and nitrate by autotrophic denitrication in bioaugmented activated sludge system

    NARCIS (Netherlands)

    Manconi, I.; Carucci, A.; Lens, P.N.L.

    2007-01-01

    An autotrophic denitrification process using reduced sulfur compounds (thiosulfate and sulfide) as electron donor in an activated sludge system is proposed as an efficient and cost effective alternative to conventional heterotrophic denitrification for inorganic (or with low C/N ratio) wastewaters

  1. 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.

  2. Removal of organic and inorganic sulfur from Ohio coal by combined physical and chemical process. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Attia, Y.A.; Zeky, M.El.; Lei, W.W.; Bavarian, F.; Yu, S. [Ohio State Univ., Columbus, OH (United States). Dept. of Materials Science and Engineering

    1989-04-28

    This project consisted of three sections. In the first part, the physical cleaning of Ohio coal by selective flocculation of ultrafine slurry was considered. In the second part, the mild oxidation process for removal of pyritic and organic sulfur.was investigated. Finally, in-the third part, the combined effects of these processes were studied. The physical cleaning and desulfurization of Ohio coal was achieved using selective flocculation of ultrafine coal slurry in conjunction with froth flotation as flocs separation method. The finely disseminated pyrite particles in Ohio coals, in particular Pittsburgh No.8 seam, make it necessary to use ultrafine ({minus}500 mesh) grinding to liberate the pyrite particles. Experiments were performed to identify the ``optimum`` operating conditions for selective flocculation process. The results indicated that the use of a totally hydrophobic flocculant (FR-7A) yielded the lowest levels of mineral matters and total sulfur contents. The use of a selective dispersant (PAAX) increased the rejection of pyritic sulfur further. In addition, different methods of floc separation techniques were tested. It was found that froth flotation system was the most efficient method for separation of small coal flocs.

  3. Synthesis and Application of Iron Oxide/Silica Gel Nanocomposite for Removal of Sulfur Dyes from Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Naser Tavassoli

    2017-03-01

    Full Text Available Background & Aims of the Study: water pollution by synthetic organic dyes is mainly regarded as environmental and ecological critical issues worldwide. In this research, magnetite iron oxide/silica gel nanocomposite (termed as Fe3O4/SG was synthesized chemically and then used as an effective adsorbent for removal of sulfur dyes from aqueous solution. Materials and Methods: The various parameters such as pH, sorbent dosage, initial dye concentration, contact time and dye solution temperature were investigated in a batch system. The equilibrium data were analyzed by Langmuir and Freundlich isotherm models. Results: The experimental data fit well with pseudo-second-order kinetic model (R2≥0.998 and conformed better to Langmuir isotherm model (R2≥0.997. The maximum adsorption capacity for Fe3O4/SG obtained from the Langmuir model was 11.1mg/g. Evaluation of thermodynamic parameters proved that the adsorption process was normally feasible, spontaneous and exothermic. Conclusion: It can be concluded that the Fe3O4/SG can be considered as a cost-effective and an environmental friendly adsorbent for efficient removal of sulfur dyes from aqueous solutions.

  4. Regenerative endodontics.

    Science.gov (United States)

    Simon, S; Smith, A J

    2014-03-01

    Significant advances in our understanding of the biological processes involved in tooth development and repair at the cellular and molecular levels have underpinned the newly emerging area of regenerative endodontics. Development of treatment protocols based on exploiting the natural wound healing properties of the dental pulp and applying tissue engineering principles has allowed reporting of case series showing preservation of tissue vitality and apexogenesis. To review current case series reporting regenerative endodontics. Current treatment approaches tend to stimulate more reparative than regenerative responses in respect of the new tissue generated, which often does not closely resemble the physiological structure of dentine-pulp. However, despite these biological limitations, such techniques appear to offer significant promise for improved treatment outcomes. Improved biological outcomes will likely emerge from the many experimental studies being reported and will further contribute to improvements in clinical treatment protocols.

  5. Regenerative process for removal of mercury and other heavy metals from gases containing H.sub.2 and/or CO

    Science.gov (United States)

    Jadhav, Raja A [Naperville, IL

    2009-07-07

    A method for removal of mercury from a gaseous stream containing the mercury, hydrogen and/or CO, and hydrogen sulfide and/or carbonyl sulfide in which a dispersed Cu-containing sorbent is contacted with the gaseous stream at a temperature in the range of about 25.degree. C. to about 300.degree. C. until the sorbent is spent. The spent sorbent is contacted with a desorbing gaseous stream at a temperature equal to or higher than the temperature at which the mercury adsorption is carried out, producing a regenerated sorbent and an exhaust gas comprising released mercury. The released mercury in the exhaust gas is captured using a high-capacity sorbent, such as sulfur-impregnated activated carbon, at a temperature less than about 100.degree. C. The regenerated sorbent may then be used to capture additional mercury from the mercury-containing gaseous stream.

  6. Effects of reactive element additions and sulfur removal on the oxidation behavior of FECRAL alloys

    International Nuclear Information System (INIS)

    Stasik, M.C.; Pettit, F.S.; Meier, G.H.; Smialek, J.L.

    1994-01-01

    The results of this study have shown that desulfurization of FeCrAl alloys by hydrogen annealing can result in improvements in cyclic oxidation comparable to that achieved by doping with reactive elements. Moreover, specimens of substantial thicknesses can be effectively desulfurized because of the high diffusivity of sulfur in bcc iron alloys. The results have also shown that there is less stress generation during the cyclic oxidation of Y-doped FeCrAl compared to Ti-doped or desulfurized FeCrAl. This indicates that the growth mechanism, as well as the strength of the oxide/alloy interface, influences the ultimate oxidation morphology and stress state which will certainly affect the length of time the alumina remains protective

  7. Removals of aqueous sulfur dioxide and hydrogen sulfide using CeO2-NiAl-LDHs coating activated carbon and its mix with carbon nano-tubes

    KAUST Repository

    Li, Jing; Chen, Fangping; Jin, Guanping; Feng, Xiaoshuang; Li, Xiaoxuan

    2015-01-01

    Ce-doped NiAl/layered double hydroxide was coated at activated carbon by urea hydrolysis method (CeO2-NiAl-LDHs/AC) in one pot, which was characterized by X-ray diffraction, infrared spectra, field emission scanning electron microscope and electrochemical techniques. CeO2-NiAl-LDHs/AC shows good uptake for aqueous sulfur dioxide (483.09mg/g) and hydrogen sulfide (181.15mg/g), respectively at 25°C. Meanwhile, the electrochemical removals of aqueous sulfur dioxide and hydrogen sulfide were respectively investigated at the mix of CeO2-NiAl-LDHs/AC and carbon nano-tubes modified homed paraffin-impregnated electrode. Both sulfur dioxide and hydrogen sulfide could be effectively oxidized to sulfuric acid at 1.0V in alkaline aqueous solution. © 2015 Elsevier B.V.

  8. Removals of aqueous sulfur dioxide and hydrogen sulfide using CeO2-NiAl-LDHs coating activated carbon and its mix with carbon nano-tubes

    KAUST Repository

    Li, Jing

    2015-07-01

    Ce-doped NiAl/layered double hydroxide was coated at activated carbon by urea hydrolysis method (CeO2-NiAl-LDHs/AC) in one pot, which was characterized by X-ray diffraction, infrared spectra, field emission scanning electron microscope and electrochemical techniques. CeO2-NiAl-LDHs/AC shows good uptake for aqueous sulfur dioxide (483.09mg/g) and hydrogen sulfide (181.15mg/g), respectively at 25°C. Meanwhile, the electrochemical removals of aqueous sulfur dioxide and hydrogen sulfide were respectively investigated at the mix of CeO2-NiAl-LDHs/AC and carbon nano-tubes modified homed paraffin-impregnated electrode. Both sulfur dioxide and hydrogen sulfide could be effectively oxidized to sulfuric acid at 1.0V in alkaline aqueous solution. © 2015 Elsevier B.V.

  9. A method for removing sulfur bearing compounds from paraffinous hydrocarbons or a directly distilled benzine fraction

    Energy Technology Data Exchange (ETDEWEB)

    Konyukhova, T.P.; Bolotskaya, I.A.; Mikhaylova, L.A.; Sadykov, A.N.; Shitovkin, N.T.; Vlasov, V.V.

    1983-01-01

    In the known method for removing sulfurorganic compounds from paraffinous hydrocarbons or a directly distilled gasoline fraction through their adsorption using natural zeolite, in order to increase the degree of purification, clinoptilolite (Kp), which contains SiO2 and A12O3 in a molar ratio of 10.6 to 16.7 is used as the natural zeolite. The purification of the paraffinous hydrocarbons through clinoptilolite adsorption as compared with mordenite adsorption makes it possible to increase the degree of their purification of ethylmercaptane and dimethylsulfide. The effectiveness of clinoptilolite is also confirmed in removing mercaptanes and sulfides from directly distilled gasoline fractions.

  10. Bioprocesses for the Removal of Volatile Sulfur Compounds from Gas Streams

    NARCIS (Netherlands)

    Janssen, A.J.H.; bosch, van den P.L.M.; Leerdam, van R.C.; Graaff, de C.M.

    2013-01-01

    This chapter describes the biological removal of sulphur compounds from gas streams. First, an overview is given of the toxicity of sulphur compounds to animals and humans whereafter biological and industrial formation routes for (organic) sulphur compounds are given. Microbial degradation routes of

  11. Near-Zero Emissions Oxy-Combustion Flue Gas Purification Task 2: SOx/Nox/Hg Removal for High Sulfur Coal

    Energy Technology Data Exchange (ETDEWEB)

    Nick Degenstein; Minish Shah; Doughlas Louie

    2012-05-01

    The goal of this project is to develop a near-zero emissions flue gas purification technology for existing PC (pulverized coal) power plants that are retrofitted with oxy-combustion technology. The objective of Task 2 of this project was to evaluate an alternative method of SOx, NOx and Hg removal from flue gas produced by burning high sulfur coal in oxy-combustion power plants. The goal of the program was not only to investigate a new method of flue gas purification but also to produce useful acid byproduct streams as an alternative to using a traditional FGD and SCR for flue gas processing. During the project two main constraints were identified that limit the ability of the process to achieve project goals. 1) Due to boiler island corrosion issues >60% of the sulfur must be removed in the boiler island with the use of an FGD. 2) A suitable method could not be found to remove NOx from the concentrated sulfuric acid product, which limits sale-ability of the acid, as well as the NOx removal efficiency of the process. Given the complexity and safety issues inherent in the cycle it is concluded that the acid product would not be directly saleable and, in this case, other flue gas purification schemes are better suited for SOx/NOx/Hg control when burning high sulfur coal, e.g. this project's Task 3 process or a traditional FGD and SCR.

  12. Specific ability of sulfur-ligands on removal of 203Hg-labeled organomercury from hemoglobin in comparison with nitrogen-ligands

    International Nuclear Information System (INIS)

    Hojo, Yasuji; Sugiura, Yukio; Tanaka, Hisashi

    1975-01-01

    Removal of 203 Hg-labeled organomercurials, bound to sulfhydryl groups of hemoglobin, by various chelating agents was investigated by the use of equilibrium dialysis. Organomercurials employed were chlormerodrin, methylmercury, ethylmercury and phenylmercury compounds. Higher and more specific effects of the sulfur-ligands, such as penicillamine and glutathione, on removal of organomercurial were found as compared with those of the nitrogen-ligands such as EDTA, glycine and polymethylenediamines. Linear correlation was observed between the degree of organomercury elimination from hemoglobin and the stability constant (log K 1 ) of 1:1 organomercury complex in both the sulfur- and nitrogen-ligand systems and at the same value of log K 1 , the elimination-effect of sulfur-ligands was extremely greater than that of the nitrogen-ligands. The relationship between the average percentage of removal and the Taft's polar substituent constant of organic moiety of the metal was also linear among the organomercury compounds other than chlormerodrin. The average removal percentage by sulfur-ligands increased in the order, ethylmercury>methylmercury>phenylmercury, while that of the nitrogen-ligands was not different among the organomercurials investigated. In addition, direct ligand-exchange reaction between hemoglobin-SH and the ligand coordinating-atom (S or N) against organomercurials rather than Ssub(N2) reaction via the ternary complex, hemoglobin-S-RHg-ligand, is postulated. (auth.)

  13. Simultaneous biological removal of sulfur, nitrogen and carbon using EGSB reactor

    Energy Technology Data Exchange (ETDEWEB)

    Chen Chuan; Ren Nanqi; Wang Aijie; Yu Zhenguo [School of Municipal and Environmental Engineering, Harbin Inst. of Tech. (China); Lee Duu-Jong [School of Municipal and Environmental Engineering, Harbin Inst. of Tech. (China); Dept. of Chemical Engineering, National Taiwan Univ., Taipei (China)

    2008-04-15

    High-rate biological conversion of sulfide and nitrate in synthetic wastewater to, respectively, elemental sulfur (S{sup 0}) and nitrogen-containing gas (such as N{sub 2}) was achieved in an expanded granular sludge bed (EGSB) reactor. A novel strategy was adopted to first cultivate mature granules using anaerobic sludge as seed sludge in sulfate-laden medium. The cultivated granules were then incubated in sulfide-laden medium to acclimate autotrophic denitrifiers. The incubated granules converted sulfide, nitrate, and acetate simultaneously in the same EGSB reactor to S{sup 0}, N-containing gases and CO{sub 2} at loading rates of 3,0 kg S m{sup -3} d{sup -1}, 1.45 kg N m{sup -3} d{sup -1}, and 2.77 kg Ac m{sup -1} d{sup -1}, respectively, and was not inhibited by sulfide concentrations up to 800 mg l{sup -1}. Effects of the C/N ratio on granule performance were identified. The granules cultivated in the sulfide-laden medium have Pseudomonas spp. and Azoarcus sp. presenting the heterotrophs and autotrophs that co-work in the high-rate EGSB-SDD (simultaneous desulfurization and denitrification) reactor. (orig.)

  14. Kinetics of Sulfur, Vanadium and Nickel Removal from Basra Crude Oil Hydro Treating

    Directory of Open Access Journals (Sweden)

    Muzher M. Ibrahim

    2013-05-01

    Full Text Available     Basra crude oil was hydro treated in trickle–bed reactor using cobalt - molybdenum alumina as a Catalyst. The reaction range temperatures was598 – 648 k, while LHSV was 0.7 – 2 hr-1. The pressure and H2/Oil for all experiments keep constant at 3Mpa and 300 L/L respectively.    Desulphurization and demutualization kinetics were studied and found that the kinetics of sculpture removal is of first – order, and the kinetic of vanadium and nickel removal is of second – order.    Activation energy were calculated and their value are 24.03, 745.86, 63.90 KJ / mole, respectively for sculpture, vanadium, and nickel.

  15. BIOTRANSFORMATION AND REMOVAL OF SULFUR FROM DIBENZOTHIOPHENE USING IMPROVED BIOCATALYTIC METHODS

    OpenAIRE

    LAROTTA, C. E; MORA, A. L; MADERO, A; MOGOLLÓN, L. I

    1998-01-01

    Three methods for the removal of sulfurfrom dibenzothiophene were evaluated using biocatalytic processes. The methods were a microbial, an enzymatic and a combined one that involves a previous enzymatic oxidation followed by microbial degradation. The byconversion was evaluated over the molecular dibenzothiophene model, obtaining higher byconversion percentages through the combined method. The microorganisms used in this study correspond to several Colombian indigenous strains isolated by dir...

  16. Multimodel Surface Temperature Responses to Removal of U.S. Sulfur Dioxide Emissions

    Science.gov (United States)

    Conley, A. J.; Westervelt, D. M.; Lamarque, J.-F.; Fiore, A. M.; Shindell, D.; Correa, G.; Faluvegi, G.; Horowitz, L. W.

    2018-03-01

    Three Earth System models are used to derive surface temperature responses to removal of U.S. anthropogenic SO2 emissions. Using multicentury perturbation runs with and without U.S. anthropogenic SO2 emissions, the local and remote surface temperature changes are estimated. In spite of a temperature drift in the control and large internal variability, 200 year simulations yield statistically significant regional surface temperature responses to the removal of U.S. SO2 emissions. Both local and remote surface temperature changes occur in all models, and the patterns of changes are similar between models for northern hemisphere land regions. We find a global average temperature sensitivity to U.S. SO2 emissions of 0.0055 K per Tg(SO2) per year with a range of (0.0036, 0.0078). We examine global and regional responses in SO4 burdens, aerosol optical depths (AODs), and effective radiative forcing (ERF). While changes in AOD and ERF are concentrated near the source region (United States), the temperature response is spread over the northern hemisphere with amplification of the temperature increase toward the Arctic. In all models, we find a significant response of dust concentrations, which affects the AOD but has no obvious effect on surface temperature. Temperature sensitivity to the ERF of U.S. SO2 emissions is found to differ from the models' sensitivity to radiative forcing of doubled CO2.

  17. Regenerative engineering

    CERN Document Server

    Laurencin, Cato T

    2013-01-01

    Regenerative Engineering: The Future of Medicine Saadiq F. El-Amin III , MD , PhD; Joylene W.L. Thomas, MD ; Ugonna N. Ihekweazu, MD ; Mia D. Woods, MS; and Ashim Gupta, MSCell Biology Gloria Gronowicz, PhD and Karen Sagomonyants, DMDStem Cells and Tissue Regeneration Kristen Martins-Taylor, PhD; Xiaofang Wang, MD , PhD; Xue-Jun Li, PhD; and Ren-He Xu, MD , PhDIntroduction to Materials Science Sangamesh G. Kumbar, PhD and Cato T. Laurencin, MD , PhDBiomaterials A. Jon Goldberg, PhD and Liisa T. Kuhn, PhDIn Vitro Assessment of Cell-Biomaterial Interactions Yong Wang, PhDHost Response to Biomate

  18. Surface characterization studies of walnut-shell biochar catalysts for simultaneously removing of organic sulfur from yellow phosphorus tail gas

    Science.gov (United States)

    Song, Xin; Li, Kai; Ning, Ping; Wang, Chi; Sun, Xin; Tang, Lihong; Ruan, Haotian; Han, Shuang

    2017-12-01

    The influences of different preparation conditions for surface characteristics on removing organic sulfur were studied. From BET, XRD, FTIR, DRIFTS, TG/DTA, CO2-TPD results, it can be seen that these preparation conditions had great influences on the pore structure, specific surface area, crystal structure and surface functional groups. The micropore volume, amorphous structure and alkalinity site strength played major roles in desulfurization process. H2S was oxidized by oxygen containing functional groups, such as sbnd COO, sbnd Cdbnd O. H2O molecule could be converted into some groups, such as sbnd CH and Csbnd OH groups, and promoted the hydrolysis reaction. The strong alkalinity site was the key factor for chemical adsorption and hydrolysis. H2O molecule, sbnd CH, Csbnd OH groups promoted the hydrolysis reaction and sbnd COO, sbnd Cdbnd O groups promoted the oxidation of H2S on the surface of WSB. Meanwhile, the main desulfurization process over WSB after carbonization was adsorption and it changed to hydrolysis reaction after activation on the surface of WSB. Furthermore, the reaction mechanism was investigated by DRIFTS measurement according to the change of surface functional groups.

  19. Field testing the effectiveness of pumping to remove sulfur hexafluoride traced drilling air from a prototype borehole near superior, Arizona

    International Nuclear Information System (INIS)

    Peters, C.A.; Striffler, P.; Yang, I.C.; Ferarese, J.

    1993-01-01

    The US Geological Survey (USGS), Department of the Interior is conducting studies at Yucca Mountain, Nevada, to provide hydrologic, hydrochemical, and geologic information to evaluate the suitability of Yucca Mountain for development as a high-level nuclear-waste repository. The USGS unsaturated-zone hydrochemistry study involves the collection of gas and water samples from the unsaturated zone for chemical and isotopic analyses. Results from these analyses will aid in the understanding of the movement of gas and water in the rock units at Yucca Mountain. A prototype borehole designated USW UZP5 was drilled by the US Department of Energy, Yucca Mountain Site Characterization Project Office (DOE, YMSCPO) in June 1990 in the Apache Leap Tuff of southcentral Arizona. The hole was dry drilled with air using sulfur hexafluoride (SF 6 ) as a tracer. This drilling method simulated that which will be used to drill boreholes for the collection of gas and water samples at Yucca Mountain. The purpose of tracing the drilling air is to quantify its removal by pumping, prior to sampling of in situ gases. The objectives of our work in Arizona were to: (1) Determine the amount of time and the pumping rates required to remove the SF 6 -enriched drilling air without inducing additional atmospheric contamination; (2) collect core samples for uniaxial compression to determine the amount of SF 6 gas that penetrated the core during drilling; (3) test the effectiveness of the SF 6 injection and sampling system; (4) test the installation and effectiveness of the prototype packer system; and (5) test the effectiveness of several core sealing methods. 1 fig., 1 tab

  20. Means of absorption for dry removal of sulfur dioxide from slack gases. Absorptionsmittel fuer die trockene Entfernung von Schwefedioxid aus Rauchgasen

    Energy Technology Data Exchange (ETDEWEB)

    Gebhard, G; Glaser, W; Hein, K

    1984-03-01

    This is a means of absorption for the dry removal of sulfur dioxide and other harmful substances from the stack gases from boilers. The means of absorption consists mainly of a fine-grained inorganic alkaline earth compound, particularly a calcium and/or a magnesium compound and an additive in the form of one or more carbonic acids and/or of their alkali salts, ammonium salts or alkaline earth salts.

  1. Identifying parameter windows for sulfur removal by direct limestone injection in the rich zone of staged heat engine combustors

    International Nuclear Information System (INIS)

    Colaluca, M.A.

    1990-01-01

    Recent experimental evidence suggests the possibility of sulfur cleanup by direct injection at gas temperatures that do not thermodynamically favor the absorption of sulfur by the limestone. The purpose of this paper is to analytically investigate possible mechanistic explanations of this observed sulfur capture with the goal of evaluating the potential for limestone injection sulfur capture in direct coal fired gas turbine and diesel engine (heat engines) combustion applications. The method was to use current available data on the physical properties of limestone, and the rates of the pertinent reactions, and to develop mathematical models of the processes experienced by the sorbent particles. The models were then used to predict extent of capture at the high-pressure, high-temperature, short residence time conditions of interest. The goal was to first investigate capture in a single-pulse reactor (combustion bomb) and then to extrapolate these results to advanced coal-fired heat engine combustion environments. Model predictions were in good agreement with observed sulfur capture in cold wall combustion bomb studies and suggest that efficient sulfur capture (in excess of 80 percent calcium utilization) may b e possible when limestone sorbents are injected into high-temperature combustion products, even when the gas temperatures exceed the thermodynamically favored temperature window by several hundred kelvins. This behavior is possible because particle temperatures are moderated and held at levels that favor sulfur capture due to the strongly endothermic calcination reaction

  2. Surface acoustic wave sensors/gas chromatography; and Low quality natural gas sulfur removal and recovery CNG Claus sulfur recovery process

    Energy Technology Data Exchange (ETDEWEB)

    Klint, B.W.; Dale, P.R.; Stephenson, C.

    1997-12-01

    This topical report consists of the two titled projects. Surface Acoustic Wave/Gas Chromatography (SAW/GC) provides a cost-effective system for collecting real-time field screening data for characterization of vapor streams contaminated with volatile organic compounds (VOCs). The Model 4100 can be used in a field screening mode to produce chromatograms in 10 seconds. This capability will allow a project manager to make immediate decisions and to avoid the long delays and high costs associated with analysis by off-site analytical laboratories. The Model 4100 is currently under evaluation by the California Environmental Protection Agency Technology Certification Program. Initial certification focuses upon the following organics: cis-dichloroethylene, chloroform, carbon tetrachloride, trichlorethylene, tetrachloroethylene, tetrachloroethane, benzene, ethylbenzene, toluene, and o-xylene. In the second study the CNG Claus process is being evaluated for conversion and recovery of elemental sulfur from hydrogen sulfide, especially found in low quality natural gas. This report describes the design, construction and operation of a pilot scale plant built to demonstrate the technical feasibility of the integrated CNG Claus process.

  3. Combination of cathodic reduction with adsorption for accelerated removal of Cr(VI) through reticulated vitreous carbon electrodes modified with sulfuric acid–glycine co-doped polyaniline

    Energy Technology Data Exchange (ETDEWEB)

    Mo, Xi [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082 (China); Yang, Zhao-hui, E-mail: yzh@hnu.edu.cn [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082 (China); Xu, Hai-yin; Zeng, Guang-ming; Huang, Jing; Yang, Xia; Song, Pei-pei; Wang, Li-ke [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082 (China)

    2015-04-09

    Highlights: • RVC/PANI-SA-GLY electrode was applied as a novel electrode material for accelerated removal of Cr(VI). • Faster reduction kinetics of Cr(VI) was observed by RVC/PANI-SA-GLY electrode when compared with RVC/PANI-SA and RVC electrode. • Cr(VI) removal experienced an adsorption-reduction system built by RVC/PANI-SA-GLY electrode. • The stability of RVC/PANI-SA-GLY electrode was relatively satisfactory. - Abstract: Improving the reduction kinetics is crucial in the electroreduction process of Cr(VI). In this study, we developed a novel adsorption–electroreduction system for accelerated removal of Cr(VI) by employing reticulated vitreous carbon electrode modified with sulfuric acid–glycine co-doped polyaniline (RVC/PANI-SA-GLY). Firstly, response surface methodology confirmed the optimum polymerization condition of co-doped polyaniline for modifying electrodes (Aniline, sulfuric acid and glycine, respectively, of 0.2 mol/L, 0.85 mol/L, 0.93 mol/L) when untraditional dopant glycine was added. Subsequently, RVC/PANI-SA-GLY showed higher Cr(VI) removal percentages in electroreduction experiments over RVC electrode modified with sulfuric acid doped polyaniline (RVC/PANI-SA) and bare RVC electrode. In contrast to RVC/PANI-SA, the improvement by RVC/PANI-SA-GLY was more significant and especially obvious at more negative potential, lower initial Cr(VI) concentration, relatively less acidic solution and higher current densities, best achieving 7.84% higher removal efficiency with entire Cr(VI) eliminated after 900 s. Current efficiencies were likewise enhanced by RVC/PANI-SA-GLY under quite negative potentials. Fourier transform infrared (FTIR) and energy dispersive spectrometer (EDS) analysis revealed a possible adsorption–reduction mechanism of RVC/PANI-SA-GLY, which greatly contributed to the faster reduction kinetics and was probably relative to the absorption between protonated amine groups of glycine and HCrO{sub 4}{sup −}. Eventually, the

  4. 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).

  5. Replacement of hazardous chromium impregnating agent from silver/copper/chromium-impregnated active carbon using triethylenediamine to remove hydrogen sulfide, trichloromethane, ammonia, and sulfur dioxide.

    Science.gov (United States)

    Wu, Li-Chun; Chung, Ying-Chien

    2009-03-01

    Activated carbon (AC) is widely used as an effective adsorbent in many applications, including industrial-scale air purification systems and air filter systems in gas masks. In general, ACs without chemical impregnation are good adsorbents of organic vapors but poor adsorbents of low-molecular-weight or polar gases such as chlorine, sulfur dioxide (SO2), formaldehyde, and ammonia (NH3). Impregnated ACs modified with metallic impregnating agents (ASC-carbons; e.g., copper, chromium, and silver) enhance the adsorbing properties of the ACs for simultaneously removing specific poisonous gases, but disposal of the chromium metal salt used to impregnate the ACs has the potential to result in situations that are toxic to both humans and the environment, thereby necessitating the search for replaceable organic impregnating agents that represent a much lower risk. The aim of this study was to assess the gas removal efficiency of an AC in which the organic impregnating agent triethylenediamine (TEDA) largely replaced the metallic impregnating agent chromium. We assessed batch and continuous adsorption capacities in situ for removing simulated hydrogen sulfide (H2S), trichloromethane (CHCl3), NH3, and SO2 gases. Brunauer-Emmet-Teller measurements and scanning electron microscopy analyses identified the removal mechanism by which TEDA-impregnated AS-carbon (dechromium ASC-carbon) adsorbs gases and determined the removal capacity for H2S, CHCl3, NH3, and SO2 to be 311, 258, 272, and 223 mg/g-C, respectively. These results demonstrate that TEDA-impregnated AS-carbon is significantly more efficient than ASC-carbon in adsorbing these four gases. Organic TEDA-impregnating agents have also been proven to be a reliable and environmental friendly agent and therefore a safe replacement of the hazardous chromium found in conventional ASC-carbon used in removing toxic gases from the airstream.

  6. Characterization of sludge properties for sewage treatment in a practical-scale down-flow hanging sponge reactor: oxygen consumption and removal of organic matter, ammonium, and sulfur.

    Science.gov (United States)

    Nomoto, Naoki; Hatamoto, Masashi; Ali, Muntjeer; Jayaswal, Komal; Iguchi, Akinori; Okubo, Tsutomu; Takahashi, Masanobu; Kubota, Kengo; Tagawa, Tadashi; Uemura, Shigeki; Yamaguchi, Takashi; Harada, Hideki

    2018-02-01

    The characteristics of sludge retained in a down-flow hanging sponge reactor were investigated to provide a better understanding of the sewage treatment process in the reactor. The organic removal and sulfur oxidation conditions were found to differ between the first layer and the following three layers. It was found that 63% and 59% of the organic matter was removed in the first layer, even though the hydraulic retention time was only 0.2 h. It is thought that the organic removal resulted from aerobic and anaerobic biodegradation on the sponge medium. The sulfate concentration increased 1.5-1.9-fold in the first layer, with almost no subsequent change in the second to fourth layers. It was shown that oxidation of sulfide in the influent was completed in the first layer. The result of the oxygen uptake rate test with an ammonium nitrogen substrate suggested that the ammonium oxidation rate was affected by the condition of dissolved oxygen (DO) or oxidation-reduction potential (ORP).

  7. Hot and Dry Cleaning of Biomass-Gasified Gas Using Activated Carbons with Simultaneous Removal of Tar, Particles, and Sulfur Compounds

    Directory of Open Access Journals (Sweden)

    Kinya Sakanishi

    2012-05-01

    Full Text Available This study proposes a gas-cleaning process for the simultaneous removal of sulfur compounds, tar, and particles from biomass-gasified gas using Fe-supported activated carbon and a water-gas shift reaction. On a laboratory scale, the simultaneous removal of H2S and COS was performed under a mixture of gases (H2/CO/CO2/CH4/C2H4/N2/H2S/COS/steam. The reactions such as COS + H2 → H2S + CO and COS + H2O → H2S + CO2 and the water-gas shift reaction were promoted on the Fe-supported activated carbon. The adsorption capacity with steam was higher than that without steam. On a bench scale, the removal of impurities from a gas derived from biomass gasification was investigated using two activated filters packed with Fe-supported activated carbon. H2S and COS, three- and four-ring polycyclic aromatic hydrocarbons (PAHs, and particles were removed and a water-gas shift reaction was promoted through the first filter at 320–350 °C. The concentrations of H2S and COS decreased to less than 0.1 ppmv. Particles and the one- and two-ring PAHs, except for benzene, were then removed through the second filter at 60–170 °C. The concentration of tar and particles decreased from 2428 to 102 mg Nm−3 and from 2244 to 181 mg Nm−3, respectively.

  8. Regenerative medicine primer.

    Science.gov (United States)

    Terzic, Andre; Nelson, Timothy J

    2013-07-01

    The pandemic of chronic diseases, compounded by the scarcity of usable donor organs, mandates radical innovation to address the growing unmet needs of individuals and populations. Beyond life-extending measures that are often the last available option, regenerative strategies offer transformative solutions in treating degenerative conditions. By leveraging newfound knowledge of the intimate processes fundamental to organogenesis and healing, the emerging regenerative armamentarium aims to boost the aptitude of human tissues for self-renewal. Regenerative technologies strive to promote, augment, and reestablish native repair processes, restituting organ structure and function. Multimodal regenerative approaches incorporate transplant of healthy tissues into damaged environments, prompt the body to enact a regenerative response in damaged tissues, and use tissue engineering to manufacture new tissue. Stem cells and their products have a unique aptitude to form specialized tissues and promote repair signaling, providing active ingredients of regenerative regimens. Concomitantly, advances in materials science and biotechnology have unlocked additional prospects for growing tissue grafts and engineering organs. Translation of regenerative principles into practice is feasible and safe in the clinical setting. Regenerative medicine and surgery are, thus, poised to transit from proof-of-principle studies toward clinical validation and, ultimately, standardization, paving the way for next-generation individualized management algorithms. Copyright © 2013 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

  9. Linde Rectiscol{reg_sign} process. The most economic and experienced wash process for removal of sulfur compounds and CO{sub 2} from gasification gases

    Energy Technology Data Exchange (ETDEWEB)

    Kaballo, H.-P.; Kerestceciogly, U. [Linde AG, Hoellriegelskreuth (Germany). Linde Engineering Division

    2006-07-01

    The Recitsol{reg_sign} wash process is a well-proven process for the removal of H{sub 2}S/COS and CO{sub 2} from coal, asphalt, pitch or oil derived synthesis gas. It is a physical gas wash system using methanol as solvent at operating temperatures below water freezing point, to produce a synthesis gas with less than 0.1 vppm of total sulfur. The CO{sub 2} content can be adjusted in a range from several mol-percent down to a few ppm, as is required by the specified application. Its main advantages are the use of cheap and readily available methanol as solvent, the very flexible process configuration, and rather low utility consumption figures compared with other wash processes, like PEGE based process or chemical washes. A modern concept of a Rectisol{reg_sign} unit is described, to treat shifted and un-shifted gases in just one plant: shifted gas was used for hydrotreating in a refinery. Unshifted gas was used as fuel gas for power generation in an IGCC. CO{sub 2} of the unshifted feed gas was removed only partly, because the remaining CO{sub 2} was fed as inert gas together with the fuel gas to an IGCC. All sulfur compounds of both feed gases were concentrated in one single stream with a high H{sub 2}S concentration. Impurities like NH{sub 3}, HCN or metal carbonyls were eliminated nearly quantitatively. 4 refs., 4 figs., 3 tabs.

  10. Regenerative medicine blueprint.

    Science.gov (United States)

    Terzic, Andre; Harper, C Michel; Gores, Gregory J; Pfenning, Michael A

    2013-12-01

    Regenerative medicine, a paragon of future healthcare, holds unprecedented potential in extending the reach of treatment modalities for individuals across diseases and lifespan. Emerging regenerative technologies, focused on structural repair and functional restoration, signal a radical transformation in medical and surgical practice. Regenerative medicine is poised to provide innovative solutions in addressing major unmet needs for patients, ranging from congenital disease and trauma to degenerative conditions. Realization of the regenerative model of care predicates a stringent interdisciplinary paradigm that will drive validated science into standardized clinical options. Designed as a catalyst in advancing rigorous new knowledge on disease causes and cures into informed delivery of quality care, the Mayo Clinic regenerative medicine blueprint offers a patient-centered, team-based strategy that optimizes the discovery-translation-application roadmap for the express purpose of science-supported practice advancement.

  11. Functionalized layered double hydroxide with nitrogen and sulfur co-decorated carbondots for highly selective and efficient removal of soft Hg2+ and Ag+ ions.

    Science.gov (United States)

    Asiabi, Hamid; Yamini, Yadollah; Shamsayei, Maryam; Molaei, Karam; Shamsipur, Mojtaba

    2018-05-28

    A facile composite was fabricated via direct assembly of nitrogen and sulfur co-decorated carbon dots with abundant oxygen-containing functional groups on the surface of the positively charged layered double hydroxide (N,S-CDs-LDH). The novel N,S-CDs-LDH demonstrates highly selective bindings (M-S) and an extremely efficient removal capacity for soft metal ions such as Ag + and Hg 2+ ions. N,S-CDs-LDH displayed a selectivity order of Ag + > Hg 2+ > Cu 2+ > Pb 2+ > Zn 2+ > Cd 2+ for their adsorption. The enormous capacities for Hg 2+ (625.0 mg g -1 ) and Ag + (714.3 mg g -1 ) and very high distribution coefficients (K d ) of 9.9 × 10 6 mL g -1 (C 0  = 20 mg L -1 ) and 2.0 × 10 7 mL g -1 (C 0  = 20 mg L -1 ) for Hg 2+ and Ag + , respectively, place the N,S-CDs-LDH at the top of LDH based materials known for such removal. The adsorption kinetic curves for Hg 2+ and Ag + fitted well with the pseudo-second order model. For Hg 2+ and Ag + , an exceptionally rapid capture with removal ∼100% within 80 min was observed (C ions  = 30 mg L -1 and V/m ratio of 1000). The adsorption isotherms were well described using Langmuir isotherm. The N,S-CDs-LDH was successfully applied to highly efficient removal of Hg 2+ and Ag + from aqueous solutions. Copyright © 2018 Elsevier B.V. All rights reserved.

  12. SPE (tm) regenerative hydrogen/oxygen fuel cells for extraterrestrial surface and microgravity applications

    Science.gov (United States)

    Mcelroy, J. F.

    1990-01-01

    Viewgraphs on SPE regenerative hydrogen/oxygen fuel cells for extraterrestrial surface and microgravity applications are presented. Topics covered include: hydrogen-oxygen regenerative fuel cell energy storage system; electrochemical cell reactions; SPE cell voltage stability; passive water removal SPE fuel cell; fuel cell performance; SPE water electrolyzers; hydrophobic oxygen phase separator; hydrophilic/electrochemical hydrogen phase separator; and unitized regenerative fuel cell.

  13. Regenerative Hydride Heat Pump

    Science.gov (United States)

    Jones, Jack A.

    1992-01-01

    Hydride heat pump features regenerative heating and single circulation loop. Counterflow heat exchangers accommodate different temperatures of FeTi and LaNi4.7Al0.3 subloops. Heating scheme increases efficiency.

  14. Fuel processor integrated H{sub 2}S catalytic partial oxidation technology for sulfur removal in fuel cell power plants

    Energy Technology Data Exchange (ETDEWEB)

    Gardner, T.H.; Berry, D.A.; Lyons, K.D.; Beer, S.K.; Freed, A.D. [U.S. Department of Energy, Morgantown, WV (USA). National Energy Technology Laboratory

    2002-12-01

    H{sub 2}S catalytic partial oxidation technology with an activated carbon catalyst was found to be a promising method for the removal of hydrogen sulfide from fuel cell hydrocarbon feedstocks. Three different fuel cell feedstocks were considered for analysis: sour natural gas, sour effluent from a liquid middle distillate fuel processor and a Texaco O{sub 2}-blown coal-derived synthesis gas. The H{sub 2}S catalytic partial oxidation reaction, its integratability into fuel cell power plants with different hydrocarbon feedstocks and its salient features are discussed. Experimental results indicate that H{sub 2}S concentration can be removed down to the part-per-million level in these plants. Additionally, a power law rate expression was developed and reaction kinetics compared to prior literature. The activation energy for this reaction was determined to be 34.4 kJ/g mol with the reaction being first order in H{sub 2}S and 0.3 order in O{sub 2}. 18 refs., 14 figs., 3 tabs.

  15. High performance sulfur, nitrogen and carbon doped mesoporous anatase–brookite TiO2 photocatalyst for the removal of microcystin-LR under visible light irradiation

    International Nuclear Information System (INIS)

    El-Sheikh, Said M.; Zhang, Geshan; El-Hosainy, Hamza M.; Ismail, Adel A.; O'Shea, Kevin E.; Falaras, Polycarpos; Kontos, Athanassios G.; Dionysiou, Dionysios D.

    2014-01-01

    Graphical abstract: - Highlights: • Synthesis of tailor-designed C, N and S doped titania anatase–brookite nano-heterojunction photocatalyst. • Microcystin-LR was completely removed in the presence of doped sample under visible light. • The MC-LR degradation rate achieved by the doped sample was much better than that of un-doped sample under visible light. - Abstract: Carbon, nitrogen and sulfur (C, N and S) doped mesoporous anatase–brookite nano-heterojunction titania photocatalysts have been synthesized through a simple sol–gel method in the presence of triblock copolymer Pluronic P123. XRD and Raman spectra revealed the formation of anatase and brookite mixed phases. XPS spectra indicated the presence of C, N and S dopants. The TEM images demonstrated the formation of almost monodisperse titania nanoparticles with particle sizes of approximately 10 nm. N 2 isotherm measurements confirmed that both doped and undoped titania anatase–brookite materials have mesoporous structure. The photocatalytic degradation of the cyanotoxin microcystin-LR (MC-LR) has been investigated using these novel nanomaterials under visible light illumination. The photocatalytic efficiency of the mesoporous titania anatase–brookite photocatalyst dramatically increased with the addition of the C, N and S non-metal, achieving complete degradation (∼100%) of MC-LR. The results demonstrate the advantages of the synthetic approach and the great potential of the visible light activated C, N, and S doped titania photocatalysts for the treatment of organic micropollutants in contaminated waters under visible light

  16. Functional bacteria and process metabolism of the Denitrifying Sulfur conversion-associated Enhanced Biological Phosphorus Removal (DS-EBPR) system: An investigation by operating the system from deterioration to restoration.

    Science.gov (United States)

    Guo, Gang; Wu, Di; Hao, Tianwei; Mackey, Hamish Robert; Wei, Li; Wang, Haiguang; Chen, Guanghao

    2016-05-15

    A sulfur conversion-associated Enhanced Biological Phosphorus (P) Removal (EBPR) system is being developed to cater for the increasing needs to treat saline/brackish wastewater resulting from seawater intrusion into groundwater and sewers and frequent use of sulfate coagulants during drinking water treatment, as well as to meet the demand for eutrophication control in warm climate regions. However, the major functional bacteria and metabolism in this emerging biological nutrient removal system are still poorly understood. This study was thus designed to explore the functional microbes and metabolism in this new EBPR system by manipulating the deterioration, failure and restoration of a lab-scale system. This was achieved by changing the mixed liquor suspended solids (MLSS) concentration to monitor and evaluate the relationships among sulfur conversion (including sulfate reduction and sulfate production), P removal, variation in microbial community structures, and stoichiometric parameters. The results show that the stable Denitrifying Sulfur conversion-associated EBPR (DS-EBPR) system was enriched by sulfate-reducing bacteria (SRB) and sulfide-oxidizing bacteria (SOB). These bacteria synergistically participated in this new EBPR process, thereby inducing an appropriate level of sulfur conversion crucial for achieving a stable DS-EBPR performance, i.e. maintaining sulfur conversion intensity at 15-40 mg S/L, corresponding to an optimal sludge concentration of 6.5 g/L. This range of sulfur conversion favors microbial community competition and various energy flows from internal polymers (i.e. polysulfide or elemental sulfur (poly-S(2-)/S(0)) and poly-β-hydroxyalkanoates (PHA)) for P removal. If this range was exceeded, the system might deteriorate or even fail due to enrichment of glycogen-accumulating organisms (GAOs). Four methods of restoring the failed system were investigated: increasing the sludge concentration, lowering the salinity or doubling the COD

  17. Synthesis and characterization of sulfur functionalized graphene oxide nanosheets as efficient sorbent for removal of Pb2+, Cd2+, Ni2+ and Zn2+ ions from aqueous solution: A combined thermodynamic and kinetic studies

    Science.gov (United States)

    Pirveysian, Mahtab; Ghiaci, Mehran

    2018-01-01

    A very simple, one pot method was used for preparation of sulfur functionalized graphene oxide (GO-SOxR) with sodium sulfide and water in reflux condition. The elemental analysis data showed high sulfur content up to 15%. EDS and XPS analysis also proved introduction of sulfur element. To make the sorbent more efficient operationally, the GO-SOxR was coated with a mesoporous shell of TiO2 or SiO2. The prepared sorbents were characterized by SEM, TEM, TGA, XPS, XRD, IR and EDS. GO-SOxR@TiO2 and GO-SOxR@SiO2 composites were tested for removal of Pb(II), Cd(II), Ni(II) and Zn(II) as heavy metal ions from aqueous solution in batch method. Adsorption of the heavy metal ions was studied kinetically, and the adsorption capacities of GO-SOxR, GO-SOxR@TiO2, and GO-SOxR@SiO2 were evaluated using equilibrium adsorption isotherms, and compared to other adsorbents used for removal of these heavy metals. Kinetic studies showed that the experimental data was fitted with pseudo second order model. The adsorption capacity of GO was significantly improved by sulfur functionalization and TiO2 coating.

  18. Summary of: Regenerative endodontics.

    Science.gov (United States)

    Clark, Stephen J

    2014-03-01

    Significant advances in our understanding of the biological processes involved in tooth development and repair at the cellular and molecular levels have underpinned the newly emerging area of regenerative endodontics. Development of treatment protocols based on exploiting the natural wound healing properties of the dental pulp and applying tissue engineering principles has allowed reporting of case series showing preservation of tissue vitality and apexogenesis. To review current case series reporting regenerative endodontics. Current treatment approaches tend to stimulate more reparative than regenerative responses in respect of the new tissue generated, which often does not closely resemble the physiological structure of dentine-pulp. However, despite these biological limitations, such techniques appear to offer significant promise for improved treatment outcomes. Improved biological outcomes will likely emerge from the many experimental studies being reported and will further contribute to improvements in clinical treatment protocols.

  19. Regenerative similariton laser

    Directory of Open Access Journals (Sweden)

    Thibault North

    2016-05-01

    Full Text Available Self-pulsating lasers based on cascaded reshaping and reamplification (2R are capable of initiating ultrashort pulses despite the accumulation of large amounts of nonlinearities in all-fiber resonators. The spectral properties of pulses in self-similar propagation are compatible with cascaded 2R regeneration by offset filtering, making parabolic pulses suitable for the design of a laser of this recently introduced class. A new type of regenerative laser giving birth to similaritons is numerically investigated and shows that this laser is the analog of regenerative sources based solely on self-phase modulation and offset filtering. The regenerative similariton laser does not suffer from instabilities due to excessive nonlinearities and enables ultrashort pulse generation in a simple cavity configuration.

  20. Seed production and dispersal of sulfur cinquefoil in northeast Oregon

    Science.gov (United States)

    Kathleen A. Dwire; Catherine G. Parks; Michael L. McInnis; Bridgett J. Naylor

    2006-01-01

    Sulfur cinquefoil (family Rosaceae) is an invasive, herbaceous perennial, native to Eurasia. It has wide ecological amplitude and has become established throughout North America in numerous habitat types. Sulfur cinquefoil reproduces only by seed (achenes); however, little is known about its regenerative strategy or reproductive biology. To improve understanding of the...

  1. Microscale Regenerative Heat Exchanger

    Science.gov (United States)

    Moran, Matthew E.; Stelter, Stephan; Stelter, Manfred

    2006-01-01

    The device described herein is designed primarily for use as a regenerative heat exchanger in a miniature Stirling engine or Stirling-cycle heat pump. A regenerative heat exchanger (sometimes called, simply, a "regenerator" in the Stirling-engine art) is basically a thermal capacitor: Its role in the Stirling cycle is to alternately accept heat from, then deliver heat to, an oscillating flow of a working fluid between compression and expansion volumes, without introducing an excessive pressure drop. These volumes are at different temperatures, and conduction of heat between these volumes is undesirable because it reduces the energy-conversion efficiency of the Stirling cycle.

  2. Device for processing regenerative wastes of ion exchange resin

    International Nuclear Information System (INIS)

    Kuroda, Osamu; Ebara, Katsuya; Shindo, Toshikazu; Takahashi, Sankichi

    1986-01-01

    Purpose: To facilitate the operation and maintenance of a processing device by dividing radioactive wastes produced in the regenerative process of ion exchange resin into a regenerated usable recovery liquid and wastes. Constitution: Sulfuric acid is recovered by a diffusion dialysis method from wastes containing sulfuric acid that are generated in the regenerative process of cation-exchange resin and also caustic soda is recovered by the diffusion dialysis method from wastes containing caustic soda that are generated in the regenerative process of anion-exchange resin. The sulfuric acid and caustic soda thus recovered are used for the regeneration of ion-exchange resin. A concentrator is provided for concentrating the sulfuric acid and caustic soda water solution to concentration suitable for the regeneration of these ion-exchange resins. Also provided is a recovery device for recovering water generated from the concentrator. This device is of so simple a constitution that its operation and maintenance can be performed very easily, thereby greatly reducing the quantity of waste liquid required to be stored in drums. (Takahashi, M.)

  3. State of the art: stem cells in equine regenerative medicine.

    Science.gov (United States)

    Lopez, M J; Jarazo, J

    2015-03-01

    According to Greek mythology, Prometheus' liver grew back nightly after it was removed each day by an eagle as punishment for giving mankind fire. Hence, contrary to popular belief, the concept of tissue and organ regeneration is not new. In the early 20th century, cell culture and ex vivo organ preservation studies by Alexis Carrel, some with famed aviator Charles Lindbergh, established a foundation for much of modern regenerative medicine. While early beliefs and discoveries foreshadowed significant accomplishments in regenerative medicine, advances in knowledge within numerous scientific disciplines, as well as nano- and micromolecular level imaging and detection technologies, have contributed to explosive advances over the last 20 years. Virtually limitless preparations, combinations and applications of the 3 major components of regenerative medicine, namely cells, biomaterials and bioactive molecules, have created a new paradigm of future therapeutic options for most species. It is increasingly clear, however, that despite significant parallels among and within species, there is no 'one-size-fits-all' regenerative therapy. Likewise, a panacea has yet to be discovered that completely reverses the consequences of time, trauma and disease. Nonetheless, there is no question that the promise and potential of regenerative medicine have forever altered medical practices. The horse is a relative newcomer to regenerative medicine applications, yet there is already a large body of work to incorporate novel regenerative therapies into standard care. This review focuses on the current state and potential future of stem cells in equine regenerative medicine. © 2014 EVJ Ltd.

  4. Bioprinting in Regenerative Medicine

    Directory of Open Access Journals (Sweden)

    Manuela Monti

    2016-02-01

    Full Text Available Prof. Turksen is a very well known scientist in the stem cell biology field and he is also internationally known for his fundamental studies on claudin-6. In addition to his research activity he is editor for the Stem Cell Biology and Regenerative Medicine series (Humana Press and editor-in-chief of Stem Cell Reviews and Reports.....

  5. Hydrogen sulfide oxidation by a microbial consortium in a recirculation reactor system: sulfur formation under oxygen limitation and removal of phenols.

    Science.gov (United States)

    Alcantara, Sergio; Velasco, Antonio; Muñoz, Ana; Cid, Juan; Revah, Sergio; Razo-Flores, Elías

    2004-02-01

    Wastewater from petroleum refining may contain a number of undesirable contaminants including sulfides, phenolic compounds, and ammonia. The concentrations of these compounds must be reduced to acceptable levels before discharge. Sulfur formation and the effect of selected phenolic compounds on the sulfide oxidation were studied in autotrophic aerobic cultures. A recirculation reactor system was implemented to improve the elemental sulfur recovery. The relation between oxygen and sulfide was determined calculating the O2/S2- loading rates (Q(O2)/Q(S)2- = Rmt), which adequately defined the operation conditions to control the sulfide oxidation. Sulfur-producing steady states were achieved at Rmt ranging from 0.5 to 1.5. The maximum sulfur formation occurred at Rmt of 0.5 where 85% of the total sulfur added to the reactor as sulfide was transformed to elemental sulfur and 90% of it was recovered from the bottom of the reactor. Sulfide was completely oxidized to sulfate (Rmt of 2) in a stirred tank reactor, even when a mixture of phenolic compounds was present in the medium. Microcosm experiments showed that carbon dioxide production increased in the presence of the phenols, suggesting that these compounds were oxidized and that they may have been used as carbon and energy source by heterotrophic microorganisms present in the consortium.

  6. Regenerative medicine in otorhinolaryngology.

    Science.gov (United States)

    Wormald, J C R; Fishman, J M; Juniat, S; Tolley, N; Birchall, M A

    2015-08-01

    Tissue engineering using biocompatible scaffolds, with or without cells, can permit surgeons to restore structure and function following tissue resection or in cases of congenital abnormality. Tracheal regeneration has emerged as a spearhead application of these technologies, whilst regenerative therapies are now being developed to treat most other diseases within otolaryngology. A systematic review of the literature was performed using Ovid Medline and Ovid Embase, from database inception to 15 November 2014. A total of 561 papers matched the search criteria, with 76 fulfilling inclusion criteria. Articles were predominantly pre-clinical animal studies, reflecting the current status of research in this field. Several key human research articles were identified and discussed. The main issues facing research in regenerative surgery are translation of animal model work into human models, increasing stem cell availability so it can be used to further research, and development of better facilities to enable implementation of these advances.

  7. Regenerative feedback resonant circuit

    Science.gov (United States)

    Jones, A. Mark; Kelly, James F.; McCloy, John S.; McMakin, Douglas L.

    2014-09-02

    A regenerative feedback resonant circuit for measuring a transient response in a loop is disclosed. The circuit includes an amplifier for generating a signal in the loop. The circuit further includes a resonator having a resonant cavity and a material located within the cavity. The signal sent into the resonator produces a resonant frequency. A variation of the resonant frequency due to perturbations in electromagnetic properties of the material is measured.

  8. Platelet-rich fibrin: a boon in regenerative endodontics.

    Science.gov (United States)

    Rebentish, Priyanka D; Umashetty, Girish; Kaur, Harpreet; Doizode, Trupthi; Kaslekar, Mithun; Chowdhury, Shouvik

    2016-12-01

    Research into regenerative dentistry has contributed momentum to the field of molecular biology. Periapical surgery aims at removing periapical pathology to achieve complete wound healing and regeneration of bone and periodontal tissue. Regenerative endodontic procedures are widely being added to the current armamentarium of pulp therapy procedures. The regenerative potential of platelets has been deliberated. Platelet-rich fibrin (PRF) is a wonderful tissue-engineering product and has recently gained much popularity due its promising results in wound healing bone induction. The features of this product are an attribute of platelets which, after cellular interactions, release growth factors and have shown application in diverse disciplines of dentistry. This paper is intended to shed light onto the various prospects of PRF and to provide clinical insight into regenerative endodontic therapy.

  9. Regenerative rehabilitation: a new future?

    Science.gov (United States)

    Perez-Terzic, Carmen; Childers, Martin K

    2014-11-01

    Modern rehabilitation medicine is propelled by newfound knowledge aimed at offering solutions for an increasingly aging population afflicted by chronic debilitating conditions. Considered a core component of future health care, the rollout of regenerative medicine underscores a paradigm shift in patient management targeted at restoring physiologic function and restituting normative impact. Nascent regenerative technologies offer unprecedented prospects in achieving repair of degenerated, diseased, or damaged tissues. In this context, principles of regenerative science are increasingly integrated in rehabilitation practices as illustrated in the present Supplement. Encompassing a growing multidisciplinary domain, the emergent era of "regenerative rehabilitation" brings radical innovations at the forefront of healthcare blueprints.

  10. Center for Neuroscience & Regenerative Medicine

    Data.gov (United States)

    Federal Laboratory Consortium — The Center for Neuroscience and Regenerative Medicine (CNRM) was established as a collaborative intramural federal program involving the U.S. Department of Defense...

  11. 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

  12. Regenerative adsorbent heat pump

    Science.gov (United States)

    Jones, Jack A. (Inventor)

    1991-01-01

    A regenerative adsorbent heat pump process and system is provided which can regenerate a high percentage of the sensible heat of the system and at least a portion of the heat of adsorption. A series of at least four compressors containing an adsorbent is provided. A large amount of heat is transferred from compressor to compressor so that heat is regenerated. The process and system are useful for air conditioning rooms, providing room heat in the winter or for hot water heating throughout the year, and, in general, for pumping heat from a lower temperature to a higher temperature.

  13. Nanotechnologies in regenerative medicine

    Czech Academy of Sciences Publication Activity Database

    Kubinová, Šárka; Syková, Eva

    2010-01-01

    Roč. 19, 3-4 (2010), s. 144-156 ISSN 1364-5706 R&D Projects: GA AV ČR IAA500390902; GA MŠk(CZ) LC554; GA AV ČR KAN201110651 Grant - others:GA ČR(CZ) 1M0538; GA ČR(CZ) GA203/09/1242; GA AV ČR(CZ) KAN200520804; EC FP6 project ENIMET(XE) LSHM-CT-2005-019063 Program:1M; GA; KA Institutional research plan: CEZ:AV0Z50390703 Keywords : Nanotechnology * regenerative medicine * nanofibers Subject RIV: FH - Neurology Impact factor: 1.051, year: 2010

  14. Regenerative laser system

    International Nuclear Information System (INIS)

    Biancardi, F.R.; Landerman, A.; Melikian, G.

    1975-01-01

    Regenerative apparatus for exhausting the working medium from the optical cavity of a laser and for supplying preheated diluent to the reaction chamber of a laser is disclosed. In an aftercooler thermal energy is exchanged between the working medium exhausted from the optical cavity and a cryogenic coolant which is subsequently utilized as the motive fluid for an ejector and as a diluent in the production of laser gas. Highly toxic and corrosive gases are condensed out of the working medium as the cryogenic coolant is evaporated and superheated. A preheater transfers additional heat to the diluent before the diluent enters the reaction chamber. (U.S.)

  15. Regenerative adsorption distillation system

    KAUST Repository

    Ng, Kim Choon

    2013-12-26

    There is provided a regenerative adsorption distillation system comprising a train of distillation effects in fluid communication with each other. The train of distillation effects comprises at least one intermediate effect between the first and last distillation effects of the train, each effect comprising a vessel and a condensing tube for flow of a fluid therein. The system further comprises a pair of adsorption-desorption beds in vapour communication with the last effect and at least one intermediate effect, wherein the beds contain an adsorbent that adsorbs vapour from the last effect and transmits desorbed vapour into at least one of the intermediate effect.

  16. Regenerative adsorption distillation system

    KAUST Repository

    Ng, Kim Choon; Thu, Kyaw; Amy, Gary; Chunggaze, Mohammed; Al-Ghasham, Tawfiq

    2013-01-01

    There is provided a regenerative adsorption distillation system comprising a train of distillation effects in fluid communication with each other. The train of distillation effects comprises at least one intermediate effect between the first and last distillation effects of the train, each effect comprising a vessel and a condensing tube for flow of a fluid therein. The system further comprises a pair of adsorption-desorption beds in vapour communication with the last effect and at least one intermediate effect, wherein the beds contain an adsorbent that adsorbs vapour from the last effect and transmits desorbed vapour into at least one of the intermediate effect.

  17. Regenerative Medicine Build-Out

    Science.gov (United States)

    Pfenning, Michael A.; Gores, Gregory J.; Harper, C. Michel

    2015-01-01

    Summary Regenerative technologies strive to boost innate repair processes and restitute normative impact. Deployment of regenerative principles into practice is poised to usher in a new era in health care, driving radical innovation in patient management to address the needs of an aging population challenged by escalating chronic diseases. There is urgency to design, execute, and validate viable paradigms for translating and implementing the science of regenerative medicine into tangible health benefits that provide value to stakeholders. A regenerative medicine model of care would entail scalable production and standardized application of clinical grade biotherapies supported by comprehensive supply chain capabilities that integrate sourcing and manufacturing with care delivery. Mayo Clinic has rolled out a blueprint for discovery, translation, and application of regenerative medicine therapies for accelerated adoption into the standard of care. To establish regenerative medical and surgical service lines, the Mayo Clinic model incorporates patient access, enabling platforms and delivery. Access is coordinated through a designated portal, the Regenerative Medicine Consult Service, serving to facilitate patient/provider education, procurement of biomaterials, referral to specialty services, and/or regenerative interventions, often in clinical trials. Platforms include the Regenerative Medicine Biotrust and Good Manufacturing Practice facilities for manufacture of clinical grade products for cell-based, acellular, and/or biomaterial applications. Care delivery leverages dedicated interventional suites for provision of regenerative services. Performance is tracked using a scorecard system to inform decision making. The Mayo Clinic roadmap exemplifies an integrated organization in the discovery, development, and delivery of regenerative medicine within a growing community of practice at the core of modern health care. Significance Regenerative medicine is at the

  18. Regenerative Medicine Build-Out.

    Science.gov (United States)

    Terzic, Andre; Pfenning, Michael A; Gores, Gregory J; Harper, C Michel

    2015-12-01

    Regenerative technologies strive to boost innate repair processes and restitute normative impact. Deployment of regenerative principles into practice is poised to usher in a new era in health care, driving radical innovation in patient management to address the needs of an aging population challenged by escalating chronic diseases. There is urgency to design, execute, and validate viable paradigms for translating and implementing the science of regenerative medicine into tangible health benefits that provide value to stakeholders. A regenerative medicine model of care would entail scalable production and standardized application of clinical grade biotherapies supported by comprehensive supply chain capabilities that integrate sourcing and manufacturing with care delivery. Mayo Clinic has rolled out a blueprint for discovery, translation, and application of regenerative medicine therapies for accelerated adoption into the standard of care. To establish regenerative medical and surgical service lines, the Mayo Clinic model incorporates patient access, enabling platforms and delivery. Access is coordinated through a designated portal, the Regenerative Medicine Consult Service, serving to facilitate patient/provider education, procurement of biomaterials, referral to specialty services, and/or regenerative interventions, often in clinical trials. Platforms include the Regenerative Medicine Biotrust and Good Manufacturing Practice facilities for manufacture of clinical grade products for cell-based, acellular, and/or biomaterial applications. Care delivery leverages dedicated interventional suites for provision of regenerative services. Performance is tracked using a scorecard system to inform decision making. The Mayo Clinic roadmap exemplifies an integrated organization in the discovery, development, and delivery of regenerative medicine within a growing community of practice at the core of modern health care. Regenerative medicine is at the vanguard of health care

  19. 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...

  20. 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. ...

  1. 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.)

  2. Active Magnetic Regenerative Liquefier

    Energy Technology Data Exchange (ETDEWEB)

    Barclay, John A. [Heracles Energy Corporation d.b.a. Prometheus Energy, Washington, DC (United States); Oseen-Send, Kathryn [Heracles Energy Corporation d.b.a. Prometheus Energy, Washington, DC (United States); Ferguson, Luke [Heracles Energy Corporation d.b.a. Prometheus Energy, Washington, DC (United States); Pouresfandiary, Jamshid [Heracles Energy Corporation d.b.a. Prometheus Energy, Washington, DC (United States); Cousins, Anand [Heracles Energy Corporation d.b.a. Prometheus Energy, Washington, DC (United States); Ralph, Heather [Heracles Energy Corporation d.b.a. Prometheus Energy, Washington, DC (United States); Hampto, Tom [Heracles Energy Corporation d.b.a. Prometheus Energy, Washington, DC (United States)

    2016-01-12

    This final report for the DOE Project entitled Active Magnetic Regenerative Liquefier (AMRL) funded under Grant DE-FG36-08GO18064 to Heracles Energy Corporation d.b.a. Prometheus Energy (Heracles/Prometheus) describes an active magnetic regenerative refrigerator (AMRR) prototype designed and built during the period from July 2008 through May 2011. The primary goal of this project was to make significant technical advances toward highly efficient liquefaction of hydrogen. Conventional hydrogen liquefiers at any scale have a maximum FOM of ~0.35 due primarily to the intrinsic difficulty of rapid, efficient compression of either hydrogen or helium working gases. Numerical simulation modeling of high performance AMRL designs indicates certain designs have promise to increase thermodynamic efficiency from a FOM of ~0.35 toward ~0.5 to ~0.6. The technical approach was the use of solid magnetic working refrigerants cycled in and out of high magnetic fields to build an efficient active regenerative magnetic refrigeration module providing cooling power for AMRL. A single-stage reciprocating AMRR with a design temperature span from ~290 K to ~120 K was built and tested with dual magnetic regenerators moving in and out of the conductively-cooled superconducting magnet subsystem. The heat transfer fluid (helium) was coupled to the process stream (refrigeration/liquefaction load) via high performance heat exchangers. In order to maximize AMRR efficiency a helium bypass loop with adjustable flow was incorporated in the design because the thermal mass of magnetic refrigerants is higher in low magnetic field than in high magnetic field. Heracles/Prometheus designed experiments to measure AMRR performance under a variety of different operational parameters such as cycle frequency, magnetic field strength, heat transfer fluid flow rate, amount of bypass flow of the heat transfer fluid while measuring work input, temperature span, cooling capability as a function of cold temperature

  3. The pharmacology of regenerative medicine.

    Science.gov (United States)

    Christ, George J; Saul, Justin M; Furth, Mark E; Andersson, Karl-Erik

    2013-07-01

    Regenerative medicine is a rapidly evolving multidisciplinary, translational research enterprise whose explicit purpose is to advance technologies for the repair and replacement of damaged cells, tissues, and organs. Scientific progress in the field has been steady and expectations for its robust clinical application continue to rise. The major thesis of this review is that the pharmacological sciences will contribute critically to the accelerated translational progress and clinical utility of regenerative medicine technologies. In 2007, we coined the phrase "regenerative pharmacology" to describe the enormous possibilities that could occur at the interface between pharmacology, regenerative medicine, and tissue engineering. The operational definition of regenerative pharmacology is "the application of pharmacological sciences to accelerate, optimize, and characterize (either in vitro or in vivo) the development, maturation, and function of bioengineered and regenerating tissues." As such, regenerative pharmacology seeks to cure disease through restoration of tissue/organ function. This strategy is distinct from standard pharmacotherapy, which is often limited to the amelioration of symptoms. Our goal here is to get pharmacologists more involved in this field of research by exposing them to the tools, opportunities, challenges, and interdisciplinary expertise that will be required to ensure awareness and galvanize involvement. To this end, we illustrate ways in which the pharmacological sciences can drive future innovations in regenerative medicine and tissue engineering and thus help to revolutionize the discovery of curative therapeutics. Hopefully, the broad foundational knowledge provided herein will spark sustained conversations among experts in diverse fields of scientific research to the benefit of all.

  4. Regenerative Therapy for Retinal Disorders

    Directory of Open Access Journals (Sweden)

    Narsis Daftarian

    2010-01-01

    Full Text Available Major advances in various disciplines of basic sciences including embryology, molecular and cell biology, genetics, and nanotechnology, as well as stem cell biology have opened new horizons for regenerative therapy. The unique characteristics of stem cells prompt a sound understanding for their use in modern regenerative therapies. This review article discusses stem cells, developmental stages of the eye field, eye field transcriptional factors, and endogenous and exogenous sources of stem cells. Recent studies and challenges in the application of stem cells for retinal pigment epithelial degeneration models will be summarized followed by obstacles facing regenerative therapy.

  5. 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

  6. Perivascular cells for regenerative medicine

    NARCIS (Netherlands)

    M. Crisan (Mihaela); M. Corselli (Mirko); W.C. Chen (William); B. Péault (Bruno)

    2012-01-01

    textabstractMesenchymal stem/stromal cells (MSC) are currently the best candidate therapeutic cells for regenerative medicine related to osteoarticular, muscular, vascular and inflammatory diseases, although these cells remain heterogeneous and necessitate a better biological characterization. We

  7. Personalized Regenerative Medicine

    Directory of Open Access Journals (Sweden)

    Babak Arjmand

    2017-03-01

    Full Text Available Personalized medicine as a novel field of medicine refers to the prescription of specific therapeutics procedure for an individual. This approach has established based on pharmacogenetic and pharmacogenomic information and data. The terms precision and personalized medicines are sometimes applied interchangeably. However, there has been a shift from “personalized medicine” towards “precision medicine”. Although personalized medicine emerged from pharmacogenetics, nowadays it covers many fields of healthcare. Accordingly, regenerative medicine and cellular therapy as the new fields of medicine use cell-based products in order to develop personalized treatments. Different sources of stem cells including mesenchymal stem cells, embryonic stem cells and induced pluripotent stem cells (iPSCs have been considered in targeted therapies which could give many advantages. iPSCs as the novel and individual pluripotent stem cells have been introduced as the appropriate candidates for personalized cell therapies. Cellular therapies can provide a personalized approach. Because of person-to-person and population differences in the result of stem cell therapy, individualized cellular therapy must be adjusted according to the patient specific profile, in order to achieve best therapeutic results and outcomes. Several factors should be considered to achieve personalized stem cells therapy such as, recipient factors, donor factors, and the overall body environment in which the stem cells could be active and functional. In addition to these factors, the source of stem cells must be carefully chosen based on functional and physical criteria that lead to optimal outcomes.

  8. Temporomandibular Joint Regenerative Medicine

    Directory of Open Access Journals (Sweden)

    Xavier Van Bellinghen

    2018-02-01

    Full Text Available The temporomandibular joint (TMJ is an articulation formed between the temporal bone and the mandibular condyle which is commonly affected. These affections are often so painful during fundamental oral activities that patients have lower quality of life. Limitations of therapeutics for severe TMJ diseases have led to increased interest in regenerative strategies combining stem cells, implantable scaffolds and well-targeting bioactive molecules. To succeed in functional and structural regeneration of TMJ is very challenging. Innovative strategies and biomaterials are absolutely crucial because TMJ can be considered as one of the most difficult tissues to regenerate due to its limited healing capacity, its unique histological and structural properties and the necessity for long-term prevention of its ossified or fibrous adhesions. The ideal approach for TMJ regeneration is a unique scaffold functionalized with an osteochondral molecular gradient containing a single stem cell population able to undergo osteogenic and chondrogenic differentiation such as BMSCs, ADSCs or DPSCs. The key for this complex regeneration is the functionalization with active molecules such as IGF-1, TGF-β1 or bFGF. This regeneration can be optimized by nano/micro-assisted functionalization and by spatiotemporal drug delivery systems orchestrating the 3D formation of TMJ tissues.

  9. A helium regenerative compressor

    International Nuclear Information System (INIS)

    Swift, W.L.; Nutt, W.E.; Sixsmith, H.

    1994-01-01

    This paper discusses the design and performance of a regenerative compressor that was developed primarily for use in cryogenic helium systems. The objectives for the development were to achieve acceptable efficiency in the machine using conventional motor and bearing technology while reducing the complexity of the system required to control contamination from the lubricants. A single stage compressor was built and tested. The compressor incorporates aerodynamically shaped blades on a 218 mm (8.6 inches) diameter impeller to achieve high efficiency. A gas-buffered non-contact shaft seal is used to oppose the diffusion of lubricant from the motor bearings into the cryogenic circuit. Since it is a rotating machine, the flow is continuous and steady, and the machine is very quiet. During performance testing with helium, the single stage machine has demonstrated a pressure ratio of 1.5 at a flow rate of 12 g/s with measured isothermal efficiencies in excess of 30%. This performance compares favorably with efficiencies generally achieved in oil flooded screw compressors

  10. Report on the finally obtained results of the study of the basement technology for environmentally friendly type metal base material regenerative utilization; Kankyo chowagata kinzokukei sozai kaisei riyo kiban gijutsu no kenkyu saishu seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    For the purpose of contributing to the resource recycling and global environmental preservation, the R and D of metal base scrap regenerative utilization technology were conducted, and the report on the finally obtained results was summed up. As to the technology to remove impurities by the solid phase treatment, the Cu removal rate of more than 96% was made possible by the low temperature fracturing technology, and that of more than 90% by the hue difference discrimination separation system technology. From the results of the FS on the low temperature fracturing technology applied to car scraps, it was found out that the present price condition is not economically efficient in the present price condition, but a possibility of achieving the removal rate of 54% in the initial plan was obtained if applying the hue difference discrimination separation system to the pretreatment. Concerning the Sn removal, the Sn removal rate of more than 70% was obtained by the gaseous phase sulfuration method, and that of more than 50% was obtained in Sn removal/Cu removal/Zn removal by the oxidation reaction method. The targets were achieved. Relating to the treatment of impurities by melting (liquid phase), the Cu removal/Sn removal technology under reduced pressure was effective in vacuum melting furnace of 2-ton scale, but the needs for the development of large capacity plasma torch were recognized in that of 40-ton scale for practical use. (NEDO)

  11. Catalytic processing of high-sulfur fuels for distributed hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Muradov, Nazim; Ramasamy, Karthik; Huang, Cunping; T-Raissi, Ali [Central Florida Univ., FL (United States)

    2010-07-01

    In this work, the development of a new on-demand hydrogen production technology is reported. In this process, a liquid hydrocarbon fuel (e.g., high-S diesel) is first catalytically pre-reformed to shorter chain gaseous hydrocarbons (predominantly, C{sub 1}-C{sub 3}) before being directed to the steam reformer, where it is converted to syngas and then to high-purity hydrogen. In the pre-reformer, most sulfurous species present in the fuel are catalytically converted to H{sub 2}S. In the desulfurization unit, H{sub 2}S is scrubbed and converted to H{sub 2} and elemental sulfur. Desulfurization of the pre-reformate gas is carried out in a special regenerative redox system, which includes Fe(II)/Fe(III)-containing aqueous phase scrubber coupled with an electrolyzer. The integrated pre-reformer/scrubber/electrolyzer unit operated successfully on high-S diesel fuel for more than 100 hours meeting the required desulfurization target of >95 % sulfur removal. (orig.)

  12. The effect of green tea extract on the removal of sulfur-containing oral malodor volatiles in vitro and its potential application in chewing gum.

    Science.gov (United States)

    Zeng, Q C; Wu, A Z; Pika, J

    2010-09-01

    Increasing pH solution from 7.5 to 8.0 was found to significantly improve the effectiveness of green tea extract for methanethiol removal in vitro. Green tea extract was also found to remove hydrogen sulfide and its effectiveness was greatly improved under alkaline conditions. It was found that with green tea extract, maximum H₂S removal was achieved when the pH was between 8.1 and 8.4 at 37 °C for 5 min. Further increases in pH resulted in decrease of the extract effectiveness. Vegetable acetone powders which contain polyphenol oxidases or peroxidases were found to further enhance the effectiveness for the removal of thiols when used in combination with green tea extracts at body temperature under alkaline conditions. Adding 5% baking soda to green tea extract-containing chewing gum was found to buffer saliva pHs to 8.0 during 10 min of chewing. However, severe discoloration was observed and undesirable bitterness was perceived, most likely due to the polymerization of unencapsulated green tea polyphenols. Therefore, encapsulation of green tea extract is recommended for applications at elevated pHs.

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

    International Nuclear Information System (INIS)

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

    1990-01-01

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

  14. Regenerative endodontics: a comprehensive review.

    Science.gov (United States)

    Kim, S G; Malek, M; Sigurdsson, A; Lin, L M; Kahler, B

    2018-05-19

    The European Society of Endodontology and the American Association for Endodontists have released position statements and clinical considerations for regenerative endodontics. There is increasing literature on this field since the initial reports of Iwaya et al. (Dental Traumatology, 17, 2001, 185) and Banchs & Trope (Journal of Endodontics, 30, 2004, 196). Endogenous stem cells from an induced periapical bleeding and scaffolds using blood clot, platelet rich plasma or platelet-rich fibrin have been utilized in regenerative endodontics. This approach has been described as a 'paradigm shift' and considered the first treatment option for immature teeth with pulp necrosis. There are three treatment outcomes of regenerative endodontics; (i) resolution of clinical signs and symptoms; (ii) further root maturation; and (iii) return of neurogenesis. It is known that results are variable for these objectives, and true regeneration of the pulp/dentine complex is not achieved. Repair derived primarily from the periodontal and osseous tissues has been shown histologically. It is hoped that with the concept of tissue engineering, namely stem cells, scaffolds and signalling molecules, that true pulp regeneration is an achievable goal. This review discusses current knowledge as well as future directions for regenerative endodontics. Patient-centred outcomes such as tooth discolouration and possibly more appointments with the potential for adverse effects needs to be discussed with patients and parents. Based on the classification of Cvek (Endodontics and Dental Traumatology, 8, 1992, 45), it is proposed that regenerative endodontics should be considered for teeth with incomplete root formation although teeth with near or complete root formation may be more suited for conventional endodontic therapy or MTA barrier techniques. However, much is still not known about clinical and biological aspects of regenerative endodontics. © 2018 International Endodontic Journal. Published by

  15. 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

  16. Aarhus Regenerative Orthopaedics Symposium (AROS)

    DEFF Research Database (Denmark)

    Foldager, Casper B.; Bendtsen, Michael; Berg, Lise C.

    2016-01-01

    to musculoskeletal pain and disability. The Aarhus Regenerative Orthopaedics Symposium (AROS) 2015 was motivated by the need to address regenerative challenges in an ageing population by engaging clinicians, basic scientists, and engineers. In this position paper, we review our contemporary understanding of societal......, patient-related, and basic science-related challenges in order to provide a reasoned roadmap for the future to deal with this compelling and urgent healthcare problem. © 2017 The Author(s). Published by Taylor & Francis on behalf of the Nordic Orthopedic Federation....

  17. Engineering cell fitness: lessons for regenerative medicine.

    Science.gov (United States)

    Shakiba, Nika; Zandstra, Peter W

    2017-10-01

    Cell competition results in the loss of weaker cells and the dominance of stronger cells. So-called 'loser' cells are either removed by active elimination or by limiting their access to survival factors. Recently, competition has been shown to serve as a surveillance mechanism against emerging aberrant cells in both the developing and adult organism, contributing to overall organism fitness and survival. Here, we explore the origins and implications of cell competition in development, tissue homeostasis, and in vitro culture. We also provide a forward look on the use of cell competition to interpret multicellular dynamics while offering a perspective on harnessing competition to engineer cells with optimized and controllable fitness characteristics for regenerative medicine applications. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  18. Regenerative-filter-incinerator device

    Energy Technology Data Exchange (ETDEWEB)

    Rosebrock, T.L.

    1977-10-18

    A regenerative-filter-incinerator device, for use in the exhaust system of a diesel engine, includes a drum-like regenerative-heat exchanger-filter assembly rotatably mounted within a housing that is adapted to be installed directly in the exhaust gas stream discharged from a diesel engine as close to the engine as possible. The regenerative-heat exchanger-filter assembly provides an inner chamber which serves as a reaction chamber for the secondary combustion of exhaust gases including particulates discharged from the engine. The regenerative-heat exchanger-filter assembly includes separately rotatable heat exchange-filter elements pervious to radial flow of fluid therethrough and adapted to filter out particulates from the exhaust gases and to carry them into the reaction chamber. During engine operation, the reaction chamber is provided with a quantity of heat, as necessary, to effect secondary combustion of the exhaust gases and particulates by means of an auxiliary heat source and the heat generated within the reaction chamber is stored in the individual heat exchange-filter elements during the discharge of exhaust gases therethrough from the reaction chamber and this heat is then transferred to the inflowing volume of the exhaust gases so that, in effect, exhaust gas is discharged from the device at substantially the same temperature as it was during its inlet into the device from the engine.

  19. Regenerative Perspective in Modern Dentistry

    Directory of Open Access Journals (Sweden)

    Mihnea Ioan Nicolescu

    2016-04-01

    Full Text Available This review aims to trace the contour lines of regenerative dentistry, to offer an introductory overview on this emerging field to both dental students and practitioners. The crystallized depiction of the concept is a translational approach, connecting dental academics to scientific research and clinical utility. Therefore, this review begins by presenting the general features of regenerative medicine, and then gradually introduces the specific aspects of major dental subdomains, highlighting the progress achieved during the last years by scientific research and, in some cases, which has already been translated into clinical results. The distinct characteristics of stem cells and their microenvironment, together with their diversity in the oral cavity, are put into the context of research and clinical use. Examples of regenerative studies regarding endodontic and periodontal compartments, as well as hard (alveolar bone and soft (salivary glands related tissues, are presented to make the reader further acquainted with the topic. Instead of providing a conclusion, we will emphasize the importance for all dental community members, from young students to experienced dentists, of an early awareness rising regarding biomedical research progress in general and regenerative dentistry in particular.

  20. 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...

  1. A primer on sulfur for the planetary geologist

    Science.gov (United States)

    Theilig, E.

    1982-01-01

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

  2. Stem Cells in Regenerative Medicine

    OpenAIRE

    Sykova, Eva; Forostyak, Serhiy

    2013-01-01

    Background: A number of cardiovascular, neurological, musculoskeletal and other diseases have a limited capacity for repair and only a modest progress has been made in treatment of brain diseases. The discovery of stem cells has opened new possibilities for the treatment of these maladies, and cell therapy now stands at the cutting-edge of modern regenerative medicine and tissue engineering. Experimental data and the first clinical trials employing stem cells have shown their broad therapeuti...

  3. Regenerative endodontics: A way forward.

    Science.gov (United States)

    Diogenes, Anibal; Ruparel, Nikita B; Shiloah, Yoav; Hargreaves, Kenneth M

    2016-05-01

    Immature teeth are susceptible to infections due to trauma, anatomic anomalies, and caries. Traditional endodontic therapies for immature teeth, such as apexification procedures, promote resolution of the disease and prevent future infections. However, these procedures fail to promote continued root development, leaving teeth susceptible to fractures. Regenerative endodontic procedures (REPs) have evolved in the past decade, being incorporated into endodontic practice and becoming a viable treatment alternative for immature teeth. The authors have summarized the status of regenerative endodontics on the basis of the available published studies and provide insight into the different levels of clinical outcomes expected from these procedures. Substantial advances in regenerative endodontics are allowing a better understanding of a multitude of factors that govern stem cell-mediated regeneration and repair of the damaged pulp-dentin complex. REPs promote healing of apical periodontitis, continued radiographic root development, and, in certain cases, vitality responses. Despite the clinical success of these procedures, they appear to promote a guided endodontic repair process rather than a true regeneration of physiological-like tissue. Immature teeth with pulpal necrosis with otherwise poor prognosis can be treated with REPs. These procedures do not preclude the possibility of apexification procedures if attempts are unsuccessful. Therefore, REPs may be considered first treatment options for immature teeth with pulpal necrosis. Copyright © 2016 American Dental Association. Published by Elsevier Inc. All rights reserved.

  4. Dental pulp stem cells: function, isolation and applications in regenerative medicine.

    Science.gov (United States)

    Tatullo, Marco; Marrelli, Massimo; Shakesheff, Kevin M; White, Lisa J

    2015-11-01

    Dental pulp stem cells (DPSCs) are a promising source of cells for numerous and varied regenerative medicine applications. Their natural function in the production of odontoblasts to create reparative dentin support applications in dentistry in the regeneration of tooth structures. However, they are also being investigated for the repair of tissues outside of the tooth. The ease of isolation of DPSCs from discarded or removed teeth offers a promising source of autologous cells, and their similarities with bone marrow stromal cells (BMSCs) suggest applications in musculoskeletal regenerative medicine. DPSCs are derived from the neural crest and, therefore, have a different developmental origin to BMSCs. These differences from BMSCs in origin and phenotype are being exploited in neurological and other applications. This review briefly highlights the source and functions of DPSCs and then focuses on in vivo applications across the breadth of regenerative medicine. © 2014 The Authors. Journal of Tissue Engineering and Regenerative Medicine published by John Wiley & Sons, Ltd.

  5. REGEN: Ancestral Genome Reconstruction for Bacteria

    OpenAIRE

    Yang, Kuan; Heath, Lenwood S.; Setubal, João C.

    2012-01-01

    Ancestral genome reconstruction can be understood as a phylogenetic study with more details than a traditional phylogenetic tree reconstruction. We present a new computational system called REGEN for ancestral bacterial genome reconstruction at both the gene and replicon levels. REGEN reconstructs gene content, contiguous gene runs, and replicon structure for each ancestral genome. Along each branch of the phylogenetic tree, REGEN infers evolutionary events, including gene creation and deleti...

  6. Regenerative Engineering and Bionic Limbs.

    Science.gov (United States)

    James, Roshan; Laurencin, Cato T

    2015-03-01

    Amputations of the upper extremity are severely debilitating, current treatments support very basic limb movement, and patients undergo extensive physiotherapy and psychological counselling. There is no prosthesis that allows the amputees near-normal function. With increasing number of amputees due to injuries sustained in accidents, natural calamities and international conflicts, there is a growing requirement for novel strategies and new discoveries. Advances have been made in technological, material and in prosthesis integration where researchers are now exploring artificial prosthesis that integrate with the residual tissues and function based on signal impulses received from the residual nerves. Efforts are focused on challenging experts in different disciplines to integrate ideas and technologies to allow for the regeneration of injured tissues, recording on tissue signals and feed-back to facilitate responsive movements and gradations of muscle force. A fully functional replacement and regenerative or integrated prosthesis will rely on interface of biological process with robotic systems to allow individual control of movement such as at the elbow, forearm, digits and thumb in the upper extremity. Regenerative engineering focused on the regeneration of complex tissue and organ systems will be realized by the cross-fertilization of advances over the past thirty years in the fields of tissue engineering, nanotechnology, stem cell science, and developmental biology. The convergence of toolboxes crated within each discipline will allow interdisciplinary teams from engineering, science, and medicine to realize new strategies, mergers of disparate technologies, such as biophysics, smart bionics, and the healing power of the mind. Tackling the clinical challenges, interfacing the biological process with bionic technologies, engineering biological control of the electronic systems, and feed-back will be the important goals in regenerative engineering over the next

  7. Regenerative braking system of PM synchronous motor

    Science.gov (United States)

    Gao, Qian; Lv, Chengxing; Zhao, Na; Zang, Hechao; Jiang, Huilue; Zhang, Zhaowen; Zhang, Fengli

    2018-04-01

    Permanent-magnet synchronous motor is widely adopted in many fields with the advantage of a high efficiency and a high torque density. Regenerative Braking Systems (RBS) provide an efficient method to assist PMSM system achieve better fuel economy and lowering exhaust emissions. This paper describes the design and testing of the regenerative braking systems of PMSM. The mode of PWM duty has been adjusted to control regenerative braking of PMSM using energy controller for the port-controlled Hamiltonian model. The simulation analysis indicates that a smooth control could be realized and the highest efficiency and the smallest current ripple could be achieved by Regenerative Braking Systems.

  8. Regenerative Rehabilitation – a New Future?

    Science.gov (United States)

    Perez-Terzic, Carmen; Childers, Martin K.

    2014-01-01

    Modern rehabilitation medicine is propelled by newfound knowledge aimed at offering solutions for an increasingly aging population afflicted by chronic debilitating conditions. Considered a core component of future healthcare, the roll-out of regenerative medicine underscores a paradigm shift in patient management targeted at restoring physiologic function and restituting normative impact. Nascent regenerative technologies offer unprecedented prospects in achieving repair of degenerated, diseased or damaged tissues. In this context, principles of regenerative science are increasingly integrated in rehabilitation practices as illustrated in the present Supplement. Encompassing a growing multidisciplinary domain, the emergent era of “regenerative rehabilitation” brings radical innovations at the forefront of healthcare blueprints. PMID:25310603

  9. The imperative for regenerative agriculture.

    Science.gov (United States)

    Rhodes, Christopher J

    2017-03-01

    A review is made of the current state of agriculture, emphasising issues of soil erosion and dependence on fossil fuels, in regard to achieving food security for a relentlessly enlarging global population. Soil has been described as "the fragile, living skin of the Earth", and yet both its aliveness and fragility have all too often been ignored in the expansion of agriculture across the face of the globe. Since it is a pivotal component in a global nexus of soil-water-air-energy, how we treat the soil can impact massively on climate change - with either beneficial or detrimental consequences, depending on whether the soil is preserved or degraded. Regenerative agriculture has at its core the intention to improve the health of soil or to restore highly degraded soil, which symbiotically enhances the quality of water, vegetation and land-productivity. By using methods of regenerative agriculture, it is possible not only to increase the amount of soil organic carbon (SOC) in existing soils, but to build new soil. This has the effect of drawing down carbon from the atmosphere, while simultaneously improving soil structure and soil health, soil fertility and crop yields, water retention and aquifer recharge - thus ameliorating both flooding and drought, and also the erosion of further soil, since runoff is reduced. Since food production on a more local scale is found to preserve the soil and its quality, urban food production should be seen as a significant potential contributor to regenerative agriculture in the future, so long as the methods employed are themselves 'regenerative'. If localisation is to become a dominant strategy for dealing with a vastly reduced use of fossil fuels, and preserving soil quality - with increased food production in towns and cities - it will be necessary to incorporate integrated ('systems') design approaches such as permaculture and the circular economy (which minimise and repurpose 'waste') within the existing urban infrastructure. In

  10. Arsenic Removal from Water Using Various Adsorbents: Magnetic Ion Exchange Resins, Hydrous Ion Oxide Particles, Granular Ferric Hydroxide, Activated Alumina, Sulfur Modified Iron, and Iron Oxide-Coated Microsand

    KAUST Repository

    Sinha, Shahnawaz

    2011-09-30

    The equilibrium and kinetic adsorption of arsenic on six different adsorbents were investigated with one synthetic and four natural types (two surface and two ground) of water. The adsorbents tested included magnetic ion exchange resins (MIEX), hydrous ion oxide particles (HIOPs), granular ferric hydroxide (GFH), activated alumina (AA), sulfur modified iron (SMI), and iron oxide-coated mic - rosand (IOC-M), which have different physicochemical properties (shape, charge, surface area, size, and metal content). The results showed that adsorption equilibriums were achieved within a contact period of 20 min. The optimal doses of adsorbents determined for a given equilibrium concentration of C eq = 10 μg/L were 500 mg/L for AA and GFH, 520–1,300 mg/L for MIEX, 1,200 mg/L for HIOPs, 2,500 mg/L for SMI, and 7,500 mg/L for IOC-M at a contact time of 60 min. At these optimal doses, the rate constants of the adsorbents were 3.9, 2.6, 2.5, 1.9, 1.8, and 1.6 1/hr for HIOPs, AA, GFH, MIEX, SMI, and IOC-M, respectively. The presence of silicate significantly reduced the arsenic removal efficiency of HIOPs, AA, and GFH, presumably due to the decrease in chemical binding affinity of arsenic in the presence of silicate. Additional experiments with natural types of water showed that, with the exception of IOC-M, the adsorbents had lower adsorption capacities in ground water than with surface and deionized water, in which the adsorption capacities decreased by approximately 60–95 % .

  11. Researches on regenerative medicine-current state

    Directory of Open Access Journals (Sweden)

    WANG Zheng-guo

    2012-11-01

    Full Text Available 【Abstract】 Since 1980s, the rapid development of tissue engineering and stem cell research has pushed re-generative medicine to a new fastigium, and regenerative medicine has become a noticeable research field in the international biology and medicine. In China, about 100 million patients need repair and regeneration treatment every year, while the number is much larger in the world. Regenerative medicine could provide effective salvation for these patients. Both Chinese Academy of Sciences and Chinese Academy of Engineering have made roadmaps of 2010-2050 and 2011-2030 for regenerative medicine. The final goal of the two roadmaps is to make China go up to leading position in most research aspects of regenerative medicine. In accord with this strategy, the government and some enterprises have invested 3-5 billion RMB (0.5-0.8 billion USD for the research on regenerative medicine. In order to push the translation of regenerative medicine forward—from bench to bedside, a strategic alliance has been established, and it includes 27 top-level research institutes, medical institutes, colleges, universities and enterprises in the field of stem cell and regeneration medicine. Recently the journal, Science, has published a special issue—Regenerative Medi-cine in China, consisting of 35 papers dealing with stem cell and regeneration, tissue engineering and regeneration, trauma and regeneration and bases for tissue repair and regenerative medicine. It is predicated that a greater breakthrough in theory and practice of regenerative medicine will be achieved in the near future (20 to 30 years. Key words: Regenerative medicine; Tissue engineering; Stem cells; Wound healing

  12. Advanced regenerative heat recovery system

    Science.gov (United States)

    Prasad, A.; Jasti, J. K.

    1982-02-01

    A regenerative heat recovery system was designed and fabricated to deliver 1500 scfm preheated air to a maximum temperature of 1600 F. Since this system is operating at 2000 F, the internal parts were designed to be fabricated with ceramic materials. This system is also designed to be adaptable to an internal metallic structure to operate in the range of 1100 to 1500 F. A test facility was designed and fabricated to test this system. The test facility is equipped to impose a pressure differential of up to 27 inches of water column in between preheated air and flue gas lines for checking possible leakage through the seals. The preliminary tests conducted on the advanced regenerative heat recovery system indicate the thermal effectiveness in the range of 60% to 70%. Bench scale studies were conducted on various ceramic and gasket materials to identify the proper material to be used in high temperature applications. A market survey was conducted to identify the application areas for this heat recovery system. A cost/benefit analysis showed a payback period of less than one and a half years.

  13. 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.

  14. Translating Regenerative Biomaterials Into Clinical Practice.

    Science.gov (United States)

    Stace, Edward T; Dakin, Stephanie G; Mouthuy, Pierre-Alexis; Carr, Andrew J

    2016-01-01

    Globally health care spending is increasing unsustainably. This is especially true of the treatment of musculoskeletal (MSK) disease where in the United States the MSK disease burden has doubled over the last 15 years. With an aging and increasingly obese population, the surge in MSK related spending is only set to worsen. Despite increased funding, research and attention to this pressing health need, little progress has been made toward novel therapies. Tissue engineering and regenerative medicine (TERM) strategies could provide the solutions required to mitigate this mounting burden. Biomaterial-based treatments in particular present a promising field of potentially cost-effective therapies. However, the translation of a scientific development to a successful treatment is fraught with difficulties. These barriers have so far limited translation of TERM science into clinical treatments. It is crucial for primary researchers to be aware of the barriers currently restricting the progression of science to treatments. Researchers need to act prospectively to ensure the clinical, financial, and regulatory hurdles which seem so far removed from laboratory science do not stall or prevent the subsequent translation of their idea into a treatment. The aim of this review is to explore the development and translation of new treatments. Increasing the understanding of these complexities and barriers among primary researchers could enhance the efficiency of biomaterial translation. © 2015 Wiley Periodicals, Inc.

  15. REGEN: Ancestral Genome Reconstruction for Bacteria

    Directory of Open Access Journals (Sweden)

    João C. Setubal

    2012-07-01

    Full Text Available Ancestral genome reconstruction can be understood as a phylogenetic study with more details than a traditional phylogenetic tree reconstruction. We present a new computational system called REGEN for ancestral bacterial genome reconstruction at both the gene and replicon levels. REGEN reconstructs gene content, contiguous gene runs, and replicon structure for each ancestral genome. Along each branch of the phylogenetic tree, REGEN infers evolutionary events, including gene creation and deletion and replicon fission and fusion. The reconstruction can be performed by either a maximum parsimony or a maximum likelihood method. Gene content reconstruction is based on the concept of neighboring gene pairs. REGEN was designed to be used with any set of genomes that are sufficiently related, which will usually be the case for bacteria within the same taxonomic order. We evaluated REGEN using simulated genomes and genomes in the Rhizobiales order.

  16. Changes in Regenerative Capacity through Lifespan

    Directory of Open Access Journals (Sweden)

    Maximina H. Yun

    2015-10-01

    Full Text Available Most organisms experience changes in regenerative abilities through their lifespan. During aging, numerous tissues exhibit a progressive decline in homeostasis and regeneration that results in tissue degeneration, malfunction and pathology. The mechanisms responsible for this decay are both cell intrinsic, such as cellular senescence, as well as cell-extrinsic, such as changes in the regenerative environment. Understanding how these mechanisms impact on regenerative processes is essential to devise therapeutic approaches to improve tissue regeneration and extend healthspan. This review offers an overview of how regenerative abilities change through lifespan in various organisms, the factors that underlie such changes and the avenues for therapeutic intervention. It focuses on established models of mammalian regeneration as well as on models in which regenerative abilities do not decline with age, as these can deliver valuable insights for our understanding of the interplay between regeneration and aging.

  17. REGEN: Ancestral Genome Reconstruction for Bacteria.

    Science.gov (United States)

    Yang, Kuan; Heath, Lenwood S; Setubal, João C

    2012-07-18

    Ancestral genome reconstruction can be understood as a phylogenetic study with more details than a traditional phylogenetic tree reconstruction. We present a new computational system called REGEN for ancestral bacterial genome reconstruction at both the gene and replicon levels. REGEN reconstructs gene content, contiguous gene runs, and replicon structure for each ancestral genome. Along each branch of the phylogenetic tree, REGEN infers evolutionary events, including gene creation and deletion and replicon fission and fusion. The reconstruction can be performed by either a maximum parsimony or a maximum likelihood method. Gene content reconstruction is based on the concept of neighboring gene pairs. REGEN was designed to be used with any set of genomes that are sufficiently related, which will usually be the case for bacteria within the same taxonomic order. We evaluated REGEN using simulated genomes and genomes in the Rhizobiales order.

  18. Transformation of sulfur during pyrolysis and hydropyrolysis of coal

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-05-01

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

  19. Regenerative Therapies for Diabetic Microangiopathy

    Directory of Open Access Journals (Sweden)

    Roberto Bassi

    2012-01-01

    Full Text Available Hyperglycaemia occurring in diabetes is responsible for accelerated arterial remodeling and atherosclerosis, affecting the macro- and the microcirculatory system. Vessel injury is mainly related to deregulation of glucose homeostasis and insulin/insulin-precursors production, generation of advanced glycation end-products, reduction in nitric oxide synthesis, and oxidative and reductive stress. It occurs both at extracellular level with increased calcium and matrix proteins deposition and at intracellular level, with abnormalities of intracellular pathways and increased cell death. Peripheral arterial disease, coronary heart disease, and ischemic stroke are the main causes of morbidity/mortality in diabetic patients representing a major clinical and economic issue. Pharmacological therapies, administration of growth factors, and stem cellular strategies are the most effective approaches and will be discussed in depth in this comprehensive review covering the regenerative therapies of diabetic microangiopathy.

  20. A regenerative elastocaloric heat pump

    DEFF Research Database (Denmark)

    Engelbrecht, Kurt; Eriksen, Dan; Dallolio, Stefano

    2016-01-01

    A large fraction of global energy use is for refrigeration and air-conditioning, which could be decarbonized if efficient renewable energy technologies could be found. Vapour-compression technology remains the most widely used system to move heat up the temperature scale after more than 100 years...... a regenerative elastocaloric heat pump that exhibits a temperature span of 15.3 K on the water side with a corresponding specific heating power up to 800 W kg−1 and maximum COP (coefficient-of-performance) values of up to 7. The efficiency and specific heating power of this device exceeds those of other devices...... based on caloric effects. These results open up the possibility of using the elastocaloric effect in various cooling and heat-pumping applications....

  1. Regenerative Medicine: Solution in Sight.

    Science.gov (United States)

    Wang, Qingjie; Stern, Jeffrey H; Temple, Sally

    2016-01-01

    The retina, like other central nervous system tissues, has poor regenerative properties in humans. Therefore, diseases that cause retinal cell loss, such as Age-related macular degeneration (AMD), retinitis pigmentosa (RP), Leber congenital amaurosis, Usher syndrome, glaucoma, and diabetic retinopathy, typically result in permanent visual impairment. Stem cell technologies have revolutionized our ability to produce neural cells in abundant supply. Much stem cell research effort is focused on producing the required cell types for cell replacement, or to generate disease-in-a-dish models to elucidate novel disease mechanisms for therapeutic development. Here we review the recent advances in stem cell studies relevant to producing RPE and retinal cells, and highlight future directions.

  2. 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.

  3. Biologically produced sulfur particles and polysulfide ions

    NARCIS (Netherlands)

    Kleinjan, W.E.

    2005-01-01

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

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

    International Nuclear Information System (INIS)

    Manowitz, B.; Lipfert, F.W.

    1990-01-01

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

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

    Science.gov (United States)

    Soleimani, Mehran; Bassi, Amarjeet; Margaritis, Argyrios

    2007-01-01

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

  6. Reflective Self-Regenerative Systems Architecture Study

    National Research Council Canada - National Science Library

    Pu, Carlton; Blough, Douglas

    2006-01-01

    In this study, we develop the Reflective Self-Regenerative Systems (RSRS) architecture in detail, describing the internal structure of each component and the mutual invocations among the components...

  7. Regenerative medicine applications in combat casualty care.

    Science.gov (United States)

    Fleming, Mark E; Bharmal, Husain; Valerio, Ian

    2014-03-01

    The purpose of this report is to describe regenerative medicine applications in the management of complex injuries sustained by service members injured in support of the wars in Afghanistan and Iraq. Improvements in body armor, resuscitative techniques and faster transport have translated into increased patient survivability and more complex wounds. Combat-related blast injuries have resulted in multiple extremity injuries, significant tissue loss and amputations. Due to the limited availability and morbidity associated with autologous tissue donor sites, the introduction of regenerative medicine has been critical in managing war extremity injuries with composite massive tissue loss. Through case reports and clinical images, this report reviews the application of regenerative medicine modalities employed to manage combat-related injuries. It illustrates that the novel use of hybrid reconstructions combining traditional and regenerative medicine approaches are an effective tool in managing wounds. Lessons learned can be adapted to civilian care.

  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 regenerative elastocaloric heat pump

    Science.gov (United States)

    Tušek, Jaka; Engelbrecht, Kurt; Eriksen, Dan; Dall'Olio, Stefano; Tušek, Janez; Pryds, Nini

    2016-10-01

    A large fraction of global energy use is for refrigeration and air-conditioning, which could be decarbonized if efficient renewable energy technologies could be found. Vapour-compression technology remains the most widely used system to move heat up the temperature scale after more than 100 years; however, caloric-based technologies (those using the magnetocaloric, electrocaloric, barocaloric or elastocaloric effect) have recently shown a significant potential as alternatives to replace this technology due to high efficiency and the use of green solid-state refrigerants. Here, we report a regenerative elastocaloric heat pump that exhibits a temperature span of 15.3 K on the water side with a corresponding specific heating power up to 800 W kg-1 and maximum COP (coefficient-of-performance) values of up to 7. The efficiency and specific heating power of this device exceeds those of other devices based on caloric effects. These results open up the possibility of using the elastocaloric effect in various cooling and heat-pumping applications.

  10. Regenerative Medicine for Neurological Disorders

    Directory of Open Access Journals (Sweden)

    Dong-Hyuk Park

    2010-01-01

    Full Text Available The annual meeting of the American Society for Neural Therapy and Repair (ASNTR has always introduced us to top-notch and up-to-date approaches for regenerative medicine related to neuroscience, ranging from stem cell–based therapy to novel drugs. The 16th ASNTR meeting focused on a variety of different topics, including the unknown pathogenesis or mechanisms of specific neurodegenerative diseases, stem cell biology, and development of novel alternative medicines or devices. Newly developed stem cells, such as amniotic epithelial stem cells and induced pluripotent stem cells, as well as well-known traditional stem cells, such as neural, embryonic, bone marrow mesenchymal, and human umbilical cord blood–derived stem cells, were reported. A number of commercialized stem cells were also covered at this meeting. Fetal neural tissues, such as ventral mesencephalon, striatum, and Schwann cells, were investigated for neurodegenerative diseases or spinal cord injury. A number of studies focused on novel methods for drug monitoring or graft tracking, and combination therapy with stem cells and medicine, such as cytokines or trophic factors. Finally, the National Institutes of Health guidelines for human stem cell research, clinical trials of commercialized stem cells without larger animal testing, and prohibition of medical tourism were big controversial issues that led to heated discussion.

  11. Staged regenerative sorption heat pump

    Science.gov (United States)

    Jones, Jack A. (Inventor)

    1995-01-01

    A regenerative adsorbent heat pump process and system for cooling and heating a space. A sorbent is confined in a plurality of compressors of which at least four are first stage and at least four are second stage. The first stage operates over a first pressure region and the second stage over a second pressure region which is higher than the first. Sorbate from the first stage enters the second stage. The sorbate loop includes a condenser, expansion valve, evaporator and the compressors. A single sorbate loop can be employed for single-temperature-control such as air conditioning and heating. Two sorbate loops can be used for two-temperature-control as in a refrigerator and freezer. The evaporator temperatures control the freezer and refrigerator temperatures. Alternatively the refrigerator temperature can be cooled by the freezer with one sorbate loop. A heat transfer fluid is circulated in a closed loop which includes a radiator and the compressors. Low temperature heat is exhausted by the radiator. High temperature heat is added to the heat transfer fluid entering the compressors which are desorbing vapor. Heat is transferred from compressors which are sorbing vapor to the heat transfer fluid, and from the heat transfer fluid to the compressors which are desorbing vapor. Each compressor is subjected to the following phases, heating to its highest temperature, cooling down from its highest temperature, cooling to its lowest temperature, and warming up from its lowest temperature. The phases are repeated to complete a cycle and regenerate heat.

  12. Recent considerations in regenerative endodontic treatment approaches

    Directory of Open Access Journals (Sweden)

    Hacer Aksel

    2014-09-01

    Conclusion: Although the regenerative treatment approaches have good clinical outcomes in the majority of case reports, the outcomes are unpredictable. Since the current clinical protocols for regenerative endodontics do not fully fulfill the triad of tissue engineering ((growth factors, scaffold and stem cells, further translational studies are required to achieve more pulp- and dentin-like tissue in the root canal system to achieve pulp regeneration.

  13. Current overview on challenges in regenerative endodontics

    Science.gov (United States)

    Bansal, Ramta; Jain, Aditya; Mittal, Sunandan

    2015-01-01

    Introduction: Regenerative endodontics provides hope of converting the non-vital tooth into vital once again. It focuses on substituting traumatized and pathological pulp with functional pulp tissue. Current regenerative procedures successfully produce root development but still fail to re-establish real pulp tissue and give unpredictable results. There are several drawbacks that need to be addressed to improve the quality and efficiency of the treatment. Aim: The aim of this review article is to discuss major priorities that ought to be dealt before applications of regenerative endodontics flourish the clinical practice. Materials and Methods: A web-based research on MEDLINE was done using filter terms Review, published in the last 10 years and Dental journals. Keywords used for research were “regenerative endodontics,” “dental stem cells,” “growth factor regeneration,” “scaffolds,” and “challenges in regeneration.” This review article screened about 150 articles and then the relevant information was compiled. Results: Inspite of the impressive growth in regenerative endodontic field, there are certain loopholes in the existing treatment protocols that might sometimes result in undesired and unpredictable outcomes. Conclusion: Considerable research and development efforts are required to improve and update existing regenerative endodontic strategies to make it an effective, safe, and biological mode to save teeth. PMID:25657518

  14. Extractive de-sulfurization and de-ashing of high sulfur coals by oxidation with ionic liquids

    International Nuclear Information System (INIS)

    Saikia, Binoy K.; Khound, Kakoli; Baruah, Bimala P.

    2014-01-01

    Highlights: • Extractive de-sulfurization and de-ashing process for cleaning high sulfur coals. • The process removes inorganic as well as organic sulfur components from high sulfur coals. • The process has less risk to chemists and other surroundings. - Abstract: The environmental consequences of energy production from coals are well known, and are driving the development of desulfurization technologies. In this investigation, ionic liquids were examined for extractive desulfurization and de-ashing in industrially important high sulfur sub-bituminous Indian coals. The ionic liquids, namely, 1-n-butyl-3-methylimidazolium tetrafluoroborate (IL1) and 1-n-butyl 3-methylimidazolium chloride (IL2) were employed for desulfurization of a few Indian coal samples in presence of HCOOH/H 2 O 2 and V 2 O 5 . Results show the maximum removal of 50.20% of the total sulfur, 48.00% of the organic sulfur, and 70.37 wt% of the ash in this process. The ionic liquids were recovered and subsequently used for further desulfurization. FT-IR spectra reveal the transformation of organic sulfur functionalities into the sulfoxides (S=O) and sulfones (-SO 2 ) due to the oxidative reactions. The sulfate, pyrite and sulfides (aryls) signals in the near edge X-ray absorption fine structure (NEXAFS) of the oxidized coal samples showed sulfur transformation during the desulfurization process. The study demonstrates the removal of significant amount of inorganic as well as organic sulfur (aryls) components from the original high sulfur coal samples to make them cleaner

  15. 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.

  16. Cell and biomolecule delivery for regenerative medicine

    Science.gov (United States)

    Smith, Ian O; Ma, Peter X

    2010-01-01

    Regenerative medicine is an exciting field that aims to create regenerative alternatives to harvest tissues for transplantation. In this approach, the delivery of cells and biological molecules plays a central role. The scaffold (synthetic temporary extracellular matrix) delivers cells to the regenerative site and provides three-dimensional environments for the cells. To fulfil these functions, we design biodegradable polymer scaffolds with structural features on multiple size scales. To enhance positive cell–material interactions, we design nano-sized structural features in the scaffolds to mimic the natural extracellular matrix. We also integrate micro-sized pore networks to facilitate mass transport and neo tissue regeneration. We also design novel polymer devices and self-assembled nanospheres for biomolecule delivery to recapitulate key events in developmental and wound healing processes. Herein, we present recent work in biomedical polymer synthesis, novel processing techniques, surface engineering and biologic delivery. Examples of enhanced cellular/tissue function and regenerative outcomes of these approaches are discussed to demonstrate the excitement of the biomimetic scaffold design and biologic delivery in regenerative medicine. PMID:27877317

  17. Mercury adsorption properties of sulfur-impregnated adsorbents

    Science.gov (United States)

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

    2002-01-01

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

  18. Sulfur transformation during rapid hydropyrolysis of coal under high pressure by using a continuous free fall pyrolyzer

    Energy Technology Data Exchange (ETDEWEB)

    W.-C. Xu; M. Kumagai

    2003-02-01

    The behavior of sulfur transformation during rapid hydropyrolysis of coal was investigated using a pressurized, continuous free fall pyrolyzer under the conditions of temperature ranging from 923 to 1123 K and hydrogen pressure up to 5 MPa. The yields of sulfur converted to gas, tar and char were determined, together with the analyses of sulfur form distributions in coals and chars. The results showed that the decomposition of inorganic sulfur species was affected only by the temperature, while the increases in temperature and hydrogen pressure obviously enhanced the removal of organic sulfur from coal. The extent of organic sulfur removal was proportional to the coal conversion, depending on coal type. A significant retention of gaseous sulfur products by the organic matrix of the char was observed during hydropyrolysis of a Chinese coal above 1023 K, even under the pressurized hydrogen atmosphere. The kinetic analysis indicates that the rate of organic sulfur removal from coal was 0.2th-order with respect to the hydrogen pressure, and the activation energy for total sulfur removal and organic sulfur removal is 17 26 and 13 55 kJ/mol, respectively. The low activation energies suggest that the transformation and removal of sulfur from coal might be controlled by the diffusion and/or thermodynamic equilibrium during hydropyrolysis under the pressurized conditions. 29 refs., 10 figs., 3 tabs.

  19. Combined hydraulic and regenerative braking system

    Science.gov (United States)

    Venkataperumal, R.R.; Mericle, G.E.

    1979-08-09

    A combined hydraulic and regenerative braking system and method for an electric vehicle is disclosed. The braking system is responsive to the applied hydraulic pressure in a brake line to control the braking of the vehicle to be completely hydraulic up to a first level of brake line pressure, to be partially hydraulic at a constant braking force and partially regenerative at a linearly increasing braking force from the first level of applied brake line pressure to a higher second level of brake line pressure, to be partially hydraulic at a linearly increasing braking force and partially regenerative at a linearly decreasing braking force from the second level of applied line pressure to a third and higher level of applied line pressure, and to be completely hydraulic at a linearly increasing braking force from the third level to all higher applied levels of line pressure.

  20. Overcoming immunological barriers in regenerative medicine.

    Science.gov (United States)

    Zakrzewski, Johannes L; van den Brink, Marcel R M; Hubbell, Jeffrey A

    2014-08-01

    Regenerative therapies that use allogeneic cells are likely to encounter immunological barriers similar to those that occur with transplantation of solid organs and allogeneic hematopoietic stem cells (HSCs). Decades of experience in clinical transplantation hold valuable lessons for regenerative medicine, offering approaches for developing tolerance-induction treatments relevant to cell therapies. Outside the field of solid-organ and allogeneic HSC transplantation, new strategies are emerging for controlling the immune response, such as methods based on biomaterials or mimicry of antigen-specific peripheral tolerance. Novel biomaterials can alter the behavior of cells in tissue-engineered constructs and can blunt host immune responses to cells and biomaterial scaffolds. Approaches to suppress autoreactive immune cells may also be useful in regenerative medicine. The most innovative solutions will be developed through closer collaboration among stem cell biologists, transplantation immunologists and materials scientists.

  1. Sulfur deactivation of fatty ester hydrogenolysis catalysts

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-08-15

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

  2. Understanding Liver Regeneration: From Mechanisms to Regenerative Medicine.

    Science.gov (United States)

    Gilgenkrantz, Hélène; Collin de l'Hortet, Alexandra

    2018-04-16

    Liver regeneration is a complex and unique process. When two-thirds of a mouse liver is removed, the remaining liver recovers its initial weight in approximately 10 days. The understanding of the mechanisms responsible for liver regeneration may help patients needing large liver resections or transplantation and may be applied to the field of regenerative medicine. All differentiated hepatocytes are capable of self-renewal, but different subpopulations of hepatocytes seem to have distinct proliferative abilities. In the setting of chronic liver diseases, a ductular reaction ensues in which liver progenitor cells (LPCs) proliferate in the periportal region. Although these LPCs have the capacity to differentiate into hepatocytes and biliary cells in vitro, their ability to participate in liver regeneration is far from clear. Their expansion has even been associated with increased fibrosis and poorer prognosis in chronic liver diseases. Controversies also remain on their origin: lineage studies in experimental mouse models of chronic injury have recently suggested that these LPCs originate from hepatocyte dedifferentiation, whereas in other situations, they seem to come from cholangiocytes. This review summarizes data published in the past 5 years in the liver regeneration field, discusses the mechanisms leading to regeneration disruption in chronic liver disorders, and addresses the potential use of novel approaches for regenerative medicine. Copyright © 2018 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  3. Clinical considerations for regenerative endodontic procedures.

    Science.gov (United States)

    Geisler, Todd M

    2012-07-01

    The management of a tooth with incomplete root maturation and a necrotic pulp is an endodontic and a restorative challenge. Apexification procedures alone leave the tooth in a weakened state and at risk for reinfection. Regenerative endodontic procedures potentially offer advantages, including the possibility of hard tissue deposition and continued root development. Case studies have reported regeneration of human pulplike tissues in vivo, but there is no protocol that reliably regenerates pulplike tissue. This article summarizes historical, current, and future regenerative treatment approaches. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. Nutrient retention capabilities of Nile tilapia ( Oreochromis niloticus) fed bio-regenerative life support system (BLSS) waste residues

    Science.gov (United States)

    Gonzales, John M.; Brown, Paul B.

    Nile tilapia were evaluated as a bio-regenerative sub-process for reducing solid waste potentially encountered in bio-regenerative life support systems. Ten juvenile Nile tilapia (mean weight = 2.05 g) were stocked into triplicate aquaria and fed one of seven experimental diets consisting of vegetable, bacterial, or food waste for a period of seven weeks. Weight gain (g), specific growth rate (mg/d), and daily consumption (g) was significantly higher ( p diet (37.99 and 68.54, respectively) followed by fish fed the wheat bran/wheat germ diet (23.19 and 63.67, respectively). Nitrogen, sulfur, and crude protein retention was significantly higher ( p diet (23.68, 21.89, and 23.68, respectively). A general loss of minerals was observed among all groups. Strong associations were observed between crude lipid retention and sulfur retention ( r2 = 0.94), crude lipid retention and carbon retention ( r2 = 0.92), WG and fiber content of dietary treatments ( r2 = 0.92), WG and carbon retention and ( r2 = 0.88), WG and lysine content of waste residues ( r2 = 0.86), crude protein retention and carbon retention ( r2 = 0.84), sulfur retention and crude protein retention ( r2 = 0.84), and total sulfur amino acid (TSAA) content of residues and WG ( r2 = 0.81). Weaker associations existed between WG and crude lipid retention ( r2 = 0.77), crude fiber content and carbon retention ( r2 = 0.76), and WG and methionine content of waste residues ( r2 = 0.75). Additional research is needed to improve the nutritional quality of fibrous residues as a means to improve tilapia's ability to utilize these residues as a food source in bio-regenerative support systems.

  5. Regenerative Braking System for Series Hybrid Electric City Bus

    OpenAIRE

    Zhang, Junzhi; Lu, Xin; Xue, Junliang; Li, Bos

    2008-01-01

    Regenerative Braking Systems (RBS) provide an efficient method to assist hybrid electric buses achieve better fuel economy while lowering exhaust emissions. This paper describes the design and testing of three regenerative braking systems, one of which is a series regenerative braking system and two of which are parallel regenerative braking systems. The existing friction based Adjustable Braking System (ABS) on the bus is integrated with each of the new braking systems in order to ensure bus...

  6. REGENERATIVE DESIGN PRACTICES IN NIGERIA: A CASE ...

    African Journals Online (AJOL)

    User

    2017-07-01

    Jul 1, 2017 ... a view to effectively implement the concept within the study area. ... REGENERATIVE DESIGN PRACTICES IN NIGERIA: A CASE STUDY OF NGOZIKA HOUSING .... could mean greater acceptance of new development by the public and .... human/environment relations based on the Cartesian separation of ...

  7. On friction braking demand with regenerative braking

    NARCIS (Netherlands)

    Walker, A.M.; Lampérth, M.U.; Wilkins, S.

    2002-01-01

    Developments in Hybrid Electric and pure Electric Vehicles are intended to improve the operational efficiency of road vehicles. Regenerative braking, which has long been established in rail vehicles, is integral to efficiency improvement, with up to 30% of overall traction energy demand satisfied by

  8. Regenerative Payload for GSAT-3 & Advanced Communication ...

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Regenerative Payload for GSAT-3 & Advanced Communication Series Satellite. GSAT-4. 8 Ka -Band Spot Beams; 8 Narrow Band (64Kbps) Channels/ Beam; 1 Wide Band (2Mbps) Channel/ Beam;; 64 Kbps Signaling Channel; On-Board Switch Matrix; 8 Channel ...

  9. Use of elastomers in regenerative braking systems

    Science.gov (United States)

    The storage of potential energy as strain energy in elastomers was investigated. The evolution of the preferred stressing scheme is described, and test results on full-size elastomeric energy storage units sized for an automotive regenerative braking system application are presented. The need for elastomeric material improvements is also discussed.

  10. Energy efficient SO2 removal from flue gases using the method Wellman-Lord

    International Nuclear Information System (INIS)

    Dzhonova-Atanasova, D.; Razkazova-Velkova, E.; Ljutzkanov, L.; Kolev, N.; Kolev, D.

    2013-01-01

    Full text: Investigations on development of energy efficient technology for SO 2 removal from flue gases of combustion systems by using the method Wellman-Lord are presented. It is characterized by absorption of sulfur dioxide with sodium sulfite solution, which reacts to form sodium bisulfite. The absorber is a packed column with multiple stages. After evaporation of the solution, SO 2 and sodium sulfite are obtained. The latter is dissolved in water from condensation of the steam carrying SO 2 from the evaporator. The regenerated solution returns in the absorber. The SO 2 removed from the flue gases is obtained as a pure product for use in chemical, food or wine production. The data discussed in the literature sources on flue gas desulfurization demonstrate the predominance of the methods with lime or limestone as absorbent, due to higher capital investments associated with the method of Wellman-Lord. A technological and economical evaluation of this regenerative method is presented in comparison to the non-regenerative gypsum method, using data from the existing sources and our own experience from the development of an innovative gypsum technology. Three solutions are discussed for significant enhancement of the method efficiency on the basis of a considerable increasing of the SO 2 concentration in the saturated absorbent. The improved method uses about 40% less heat for absorbent regeneration, in comparison to the existing applications of the method Wellman-Lord, and gives in addition the possibility to regenerate 95% of the consumed heat for heating water streams to about 90°C. Moreover, the incorporation in the installation of our system with contact economizers of second generation, already in industrial application, enables utilization of the waste heat of the flue gases for district heating. The employment of this system also leads to significant decreasing of the NO x emissions. key words: SO 2 removal, flue gases, absorption

  11. Giant hepatic regenerative nodules in Alagille syndrome

    International Nuclear Information System (INIS)

    Rapp, Jordan B.; Bellah, Richard D.; Anupindi, Sudha A.; Maya, Carolina; Pawel, Bruce R.

    2017-01-01

    Children with Alagille syndrome undergo surveillance radiologic examinations as they are at risk for developing cirrhosis and hepatocellular carcinoma. There is limited literature on the imaging of liver masses in Alagille syndrome. We report the ultrasound (US) and magnetic resonance imaging (MRI) appearances of incidental benign giant hepatic regenerative nodules in this population. To describe the imaging findings of giant regenerative nodules in patients with Alagille syndrome. A retrospective search of the hospital database was performed to find all cases of hepatic masses in patients with Alagille syndrome during a 10-year period. Imaging, clinical charts, laboratory data and available pathology were reviewed and analyzed and summarized for each patient. Twenty of 45 patients with confirmed Alagille syndrome had imaging studies. Of those, we identified six with giant focal liver masses. All six patients had large central hepatic masses that were remarkably similar on US and MRI, in addition to having features of cirrhosis. In each case, the mass was located in hepatic segment VIII and imaging showed the mass splaying the main portal venous branches at the hepatic hilum, as well as smaller portal and hepatic venous branches coursing through them. On MRI, signal intensity of the mass was isointense to liver on T1-weighted sequences in four of six patients, but hyperintense on T1 in two of six patients. In all six cases, the mass was hypointense on T2- weighted sequences. The mass post-contrast was isointense to adjacent liver in all phases in five the cases. Five out of six patients had pathological correlation demonstrating preserved ductal architecture confirming the final diagnosis of a regenerative nodule. Giant hepatic regenerative nodules with characteristic US and MR features can occur in patients with Alagille syndrome with underlying cirrhosis. Recognizing these lesions as benign giant hepatic regenerative nodules should, thereby, mitigate any need for

  12. Giant hepatic regenerative nodules in Alagille syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Rapp, Jordan B. [Lewis Katz School of Medicine at Temple University, Department of Radiology, Temple University Hospital, Philadelphia, PA (United States); Bellah, Richard D.; Anupindi, Sudha A. [The Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States); University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA (United States); Maya, Carolina [The Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States); Pawel, Bruce R. [University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA (United States); The Children' s Hospital of Philadelphia, Department of Pathology and Laboratory Medicine, Philadelphia, PA (United States)

    2017-02-15

    Children with Alagille syndrome undergo surveillance radiologic examinations as they are at risk for developing cirrhosis and hepatocellular carcinoma. There is limited literature on the imaging of liver masses in Alagille syndrome. We report the ultrasound (US) and magnetic resonance imaging (MRI) appearances of incidental benign giant hepatic regenerative nodules in this population. To describe the imaging findings of giant regenerative nodules in patients with Alagille syndrome. A retrospective search of the hospital database was performed to find all cases of hepatic masses in patients with Alagille syndrome during a 10-year period. Imaging, clinical charts, laboratory data and available pathology were reviewed and analyzed and summarized for each patient. Twenty of 45 patients with confirmed Alagille syndrome had imaging studies. Of those, we identified six with giant focal liver masses. All six patients had large central hepatic masses that were remarkably similar on US and MRI, in addition to having features of cirrhosis. In each case, the mass was located in hepatic segment VIII and imaging showed the mass splaying the main portal venous branches at the hepatic hilum, as well as smaller portal and hepatic venous branches coursing through them. On MRI, signal intensity of the mass was isointense to liver on T1-weighted sequences in four of six patients, but hyperintense on T1 in two of six patients. In all six cases, the mass was hypointense on T2- weighted sequences. The mass post-contrast was isointense to adjacent liver in all phases in five the cases. Five out of six patients had pathological correlation demonstrating preserved ductal architecture confirming the final diagnosis of a regenerative nodule. Giant hepatic regenerative nodules with characteristic US and MR features can occur in patients with Alagille syndrome with underlying cirrhosis. Recognizing these lesions as benign giant hepatic regenerative nodules should, thereby, mitigate any need for

  13. 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.

  14. 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.

  15. 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

  16. 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

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

    Science.gov (United States)

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

    2017-08-01

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

  18. Development of enhanced sulfur rejection processes

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-03-01

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

  19. [Progress in stem cells and regenerative medicine].

    Science.gov (United States)

    Wang, Libin; Zhu, He; Hao, Jie; Zhou, Qi

    2015-06-01

    Stem cells have the ability to differentiate into all types of cells in the body and therefore have great application potential in regenerative medicine, in vitro disease modelling and drug screening. In recent years, stem cell technology has made great progress, and induced pluripotent stem cell technology revolutionizes the whole stem cell field. At the same time, stem cell research in our country has also achieved great progress and becomes an indispensable power in the worldwide stem cell research field. This review mainly focuses on the research progress in stem cells and regenerative medicine in our country since the advent of induced pluripotent stem cell technology, including induced pluripotent stem cells, transdifferentiation, haploid stem cells, and new gene editing tools.

  20. Induced pluripotent stem cells for regenerative medicine.

    Science.gov (United States)

    Hirschi, Karen K; Li, Song; Roy, Krishnendu

    2014-07-11

    With the discovery of induced pluripotent stem (iPS) cells, it is now possible to convert differentiated somatic cells into multipotent stem cells that have the capacity to generate all cell types of adult tissues. Thus, there is a wide variety of applications for this technology, including regenerative medicine, in vitro disease modeling, and drug screening/discovery. Although biological and biochemical techniques have been well established for cell reprogramming, bioengineering technologies offer novel tools for the reprogramming, expansion, isolation, and differentiation of iPS cells. In this article, we review these bioengineering approaches for the derivation and manipulation of iPS cells and focus on their relevance to regenerative medicine.

  1. Regenerative endodontics: A state of the art

    Directory of Open Access Journals (Sweden)

    Rashmi Bansal

    2011-01-01

    Full Text Available Scientific advances in the creation of restorative biomaterials, in vitro cell culture technology, tissue grafting, tissue engineering, molecular biology and the human genome project provide the basis for the introduction of new technologies into dentistry. Non-vital infected teeth have long been treated with root canal therapy (for mature root apex and apexification (for immature root apex, or doomed to extraction. Although successful, current treatments fail to re-establish healthy pulp tissue in these teeth. But, what if the non-vital tooth could be made vital once again? That is the hope offered by regenerative endodontics, an emerging field focused on replacing traumatized and diseased pulp with functional pulp tissue. Restoration of vitality of non-vital tooth is based on tissue engineering and revascularization procedures. The purpose of this article is to review these biological procedures and the hurdles that must be overcome to develop regenerative endodontic procedures.

  2. Regenerative Endodontics: A Road Less Travelled

    Science.gov (United States)

    Bansal, Ramta; Mittal, Sunandan; Kumar, Tarun; Kaur, Dilpreet

    2014-01-01

    Although traditional approaches like root canal therapy and apexification procedures have been successful in treating diseased or infected root canals, but these modalities fail to re-establish healthy pulp tissue in treated teeth. Regeneration-based approaches aims to offer high levels of success by replacing diseased or necrotic pulp tissues with healthy pulp tissue to revitalize teeth. The applications of regenerative approaches in dental clinics have potential to dramatically improve patients’ quality of life. This review article offers a detailed overview of present regenerative endodontic approaches aiming to revitalize teeth and also outlines the problems to be dealt before this emerging field contributes to clinical treatment protocols. It conjointly covers the basic trilogy elements of tissue engineering. PMID:25478476

  3. Micro-Scale Regenerative Heat Exchanger

    Science.gov (United States)

    Moran, Matthew E.; Stelter, Stephan; Stelter, Manfred

    2004-01-01

    A micro-scale regenerative heat exchanger has been designed, optimized and fabricated for use in a micro-Stirling device. Novel design and fabrication techniques enabled the minimization of axial heat conduction losses and pressure drop, while maximizing thermal regenerative performance. The fabricated prototype is comprised of ten separate assembled layers of alternating metal-dielectric composite. Each layer is offset to minimize conduction losses and maximize heat transfer by boundary layer disruption. A grating pattern of 100 micron square non-contiguous flow passages were formed with a nominal 20 micron wall thickness, and an overall assembled ten-layer thickness of 900 microns. Application of the micro heat exchanger is envisioned in the areas of micro-refrigerators/coolers, micropower devices, and micro-fluidic devices.

  4. Introduction to regenerative medicine and tissue engineering.

    Science.gov (United States)

    Stoltz, J-F; Decot, V; Huseltein, C; He, X; Zhang, L; Magdalou, J; Li, Y P; Menu, P; Li, N; Wang, Y Y; de Isla, N; Bensoussan, D

    2012-01-01

    Human tissues don't regenerate spontaneously, explaining why regenerative medicine and cell therapy represent a promising alternative treatment (autologous cells or stem cells of different origins). The principle is simple: cells are collected, expanded and introduced with or without modification into injured tissues or organs. Among middle-term therapeutic applications, cartilage defects, bone repair, cardiac insufficiency, burns, liver or bladder, neurodegenerative disorders could be considered.

  5. Optimization of an irreversible Stirling regenerative cycle

    International Nuclear Information System (INIS)

    Aragón-González, G; Cano-Bianco, M; León-Galicia, A; Rivera-Camacho, J M

    2015-01-01

    In this work a Stirling regenerative cycle with some irreversibilities is analyzed. The analyzed irreversibilities are located at the heat exchangers. They receive a finite amount of heat and heat leakage occurs between both reservoirs. Using this model, power and the efficiency at maximum power are obtained. Some optimal design parameters for the exchanger heat areas and thermal conductances are presented. The relation between the power, efficiency and the results obtained are shown graphically

  6. Adaptive Regenerative Braking in Electric Vehicles

    OpenAIRE

    Kubaisi, Rayad

    2018-01-01

    Elektrofahrzeuge fahren lokal emissionsfrei und tragen damit dazu bei, die Emissionen in Städten zu reduzieren. Zusätzlich, zeichnen sich Elektrofahrzeuge durch ein dynamisches Fahrverhalten aus. Nachteilig wirkt sich bei den meisten Elektrofahrzeugen, die geringe Reichweite auf die Akzeptanz bei Neuwagenkäufern aus. Eine der Maßnahmen zur Erhöhung der Reichweite von Elektrofahrzeuge ist das regenerative Bremsen. Hierbei wird die kinetische Energie des Fahrzeugs durch generatorisches...

  7. Induced Pluripotent Stem Cells for Regenerative Medicine

    OpenAIRE

    Hirschi, Karen K.; Li, Song; Roy, Krishnendu

    2014-01-01

    With the discovery of induced pluripotent stem (iPS) cells, it is now possible to convert differentiated somatic cells into multipotent stem cells that have the capacity to generate all cell types of adult tissues. Thus, there is a wide variety of applications for this technology, including regenerative medicine, in vitro disease modeling, and drug screening/discovery. Although biological and biochemical techniques have been well established for cell reprogramming, bioengineering technologies...

  8. Regenerative Intelligent Brake Control for Electric Motorcycles

    Directory of Open Access Journals (Sweden)

    Juan Jesús Castillo Aguilar

    2017-10-01

    Full Text Available Vehicle models whose propulsion system is based on electric motors are increasing in number within the automobile industry. They will soon become a reliable alternative to vehicles with conventional propulsion systems. The main advantages of this type of vehicles are the non-emission of polluting gases and noise and the effectiveness of electric motors compared to combustion engines. Some of the disadvantages that electric vehicle manufacturers still have to solve are their low autonomy due to inefficient energy storage systems, vehicle cost, which is still too high, and reducing the recharging time. Current regenerative systems in motorcycles are designed with a low fixed maximum regeneration rate in order not to cause the rear wheel to slip when braking with the regenerative brake no matter what the road condition is. These types of systems do not make use of all the available regeneration power, since more importance is placed on safety when braking. An optimized regenerative braking strategy for two-wheeled vehicles is described is this work. This system is designed to recover the maximum energy in braking processes while maintaining the vehicle’s stability. In order to develop the previously described regenerative control, tyre forces, vehicle speed and road adhesion are obtained by means of an estimation algorithm. A based-on-fuzzy-logic algorithm is programmed to carry out an optimized control with this information. This system recuperates maximum braking power without compromising the rear wheel slip and safety. Simulations show that the system optimizes energy regeneration on every surface compared to a constant regeneration strategy.

  9. A solar regenerative thermoelectrochemical converter (RTEC)

    Energy Technology Data Exchange (ETDEWEB)

    Townsend, C.W.; McHardy, J. (Hughes Aircraft Co., El Segundo, CA (United States))

    1992-02-01

    This is an executive summary of a final subcontract report that describes the successful completion of a closed-loop demonstration of a regenerative thermoelectromechanical device using solar heat input for the production of electricity. The full report, which contains a detailed description of the two-year effort, is currently subject to a government secrecy order which precludes public release of the information. Copies of the full report will be made available for general release whenever the secrecy order is lifted.

  10. Advanced Byproduct Recovery: Direct Catalytic Reduction of Sulfur Dioxide to Elemental Sulfur.

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-06-01

    More than 170 wet scrubber systems applied, to 72,000 MW of U.S., coal-fired, utility boilers are in operation or under construction. In these systems, the sulfur dioxide removed from the boiler flue gas is permanently bound to a sorbent material, such as lime or limestone. The sulfated sorbent must be disposed of as a waste product or, in some cases, sold as a byproduct (e.g. gypsum). Due to the abundance and low cost of naturally occurring gypsum, and the costs associated with producing an industrial quality product, less than 7% of these scrubbers are configured to produce usable gypsum (and only 1% of all units actually sell the byproduct). The disposal of solid waste from each of these scrubbers requires a landfill area of approximately 200 to 400 acres. In the U.S., a total of 19 million tons of disposable FGD byproduct are produced, transported and disposed of in landfills annually. The use of regenerable sorbent technologies has the potential to reduce or eliminate solid waste production, transportation and disposal. In a regenerable sorbent system, the sulfur dioxide in the boiler flue gas is removed by the sorbent in an adsorber. The S0{sub 2}s subsequently released, in higher concentration, in a regenerator. All regenerable systems produce an off-gas stream from the regenerator that must be processed further in order to obtain a salable byproduct, such as elemental sulfur, sulfuric acid or liquid S0{sub 2}.

  11. Microaeration for hydrogen sulfide removal in UASB reactor.

    Science.gov (United States)

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

    2014-11-01

    The removal of hydrogen sulfide from biogas by microaeration was studied in Up-flow Anaerobic Sludge Blanket (UASB) reactors treating synthetic brewery wastewater. A fully anaerobic UASB reactor served as a control while air was dosed into a microaerobic UASB reactor (UMSB). After a year of operation, sulfur balance was described in both reactors. In UASB, sulfur was mainly presented in the effluent as sulfide (49%) and in biogas as hydrogen sulfide (34%). In UMSB, 74% of sulfur was detected in the effluent (41% being sulfide and 33% being elemental sulfur), 10% accumulated in headspace as elemental sulfur and 9% escaped in biogas as hydrogen sulfide. The efficiency of hydrogen sulfide removal in UMSB was on average 73%. Microaeration did not cause any decrease in COD removal or methanogenic activity in UMSB and the elemental sulfur produced by microaeration did not accumulate in granular sludge. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. An animal model to study regenerative endodontics.

    Science.gov (United States)

    Torabinejad, Mahmoud; Corr, Robert; Buhrley, Matthew; Wright, Kenneth; Shabahang, Shahrokh

    2011-02-01

    A growing body of evidence is demonstrating the possibility for regeneration of tissues within the pulp space and continued root development in teeth with necrotic pulps and open apices. There are areas of research related to regenerative endodontics that need to be investigated in an animal model. The purpose of this study was to investigate ferret cuspid teeth as a model to investigate factors involved in regenerative endodontics. Six young male ferrets between the ages of 36-133 days were used in this investigation. Each animal was anesthetized and perfused with 10% buffered formalin. Block sections including the mandibular and maxillary cuspid teeth and their surrounding periapical tissues were obtained, radiographed, decalcified, sectioned, and stained with hematoxylin-eosin to determine various stages of apical closure in these teeth. The permanent mandibular and maxillary cuspid teeth with open apices erupted approximately 50 days after birth. Initial signs of closure of the apical foramen in these teeth were observed between 90-110 days. Complete apical closure was observed in the cuspid teeth when the animals were 133 days old. Based on the experiment, ferret cuspid teeth can be used to investigate various factors involved in regenerative endodontics that cannot be tested in human subjects. The most appropriate time to conduct the experiments would be when the ferrets are between the ages of 50 and 90 days. Copyright © 2011. Published by Elsevier Inc.

  13. Regenerative endodontics--Creating new horizons.

    Science.gov (United States)

    Dhillon, Harnoor; Kaushik, Mamta; Sharma, Roshni

    2016-05-01

    Trauma to the dental pulp, physical or microbiologic, can lead to inflammation of the pulp followed by necrosis. The current treatment modality for such cases is non-surgical root canal treatment. The damaged tissue is extirpated and the root canal system prepared. It is then obturated with an inert material such a gutta percha. In spite of advances in techniques and materials, 10%-15% of the cases may end in failure of treatment. Regenerative endodontics combines principles of endodontics, cell biology, and tissue engineering to provide an ideal treatment for inflamed and necrotic pulp. It utilizes mesenchymal stem cells, growth factors, and organ tissue culture to provide treatment. Potential treatment modalities include induction of blood clot for pulp revascularization, scaffold aided regeneration, and pulp implantation. Although in its infancy, successful treatment of damaged pulp tissue has been performed using principles of regenerative endodontics. This field is dynamic and exciting with the ability to shape the future of endodontics. This article highlights the fundamental concepts, protocol for treatment, and possible avenues for research in regenerative endodontics. © 2015 Wiley Periodicals, Inc.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-01-15

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

  15. 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.

  16. 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...

  17. Compact Water Vapor Exchanger for Regenerative Life Support Systems

    Science.gov (United States)

    Izenson, Michael G.; Chen, Weibo; Anderson, Molly; Hodgson, Edward

    2012-01-01

    Thermal and environmental control systems for future exploration spacecraft must meet challenging requirements for efficient operation and conservation of resources. Regenerative CO2 removal systems are attractive for these missions because they do not use consumable CO2 absorbers. However, these systems also absorb and vent water to space along with carbon dioxide. This paper describes an innovative device designed to minimize water lost from regenerative CO2 control systems. Design studies and proof-of-concept testing have shown the feasibility of a compact, efficient membrane water vapor exchanger (WVX) that will conserve water while meeting challenging requirements for operation on future spacecraft. Compared to conventional WVX designs, the innovative membrane WVX described here has the potential for high water recovery efficiency, compact size, and very low pressure losses. The key innovation is a method for maintaining highly uniform flow channels in a WVX core built from water-permeable membranes. The proof-of-concept WVX incorporates all the key design features of a prototypical unit, except that it is relatively small scale (1/23 relative to a unit sized for a crew of six) and some components were fabricated using non-prototypical methods. The proof-of-concept WVX achieved over 90% water recovery efficiency in a compact core in good agreement with analysis models. Furthermore the overall pressure drop is very small (less than 0.5 in. H2O, total for both flow streams) and meets requirements for service in environmental control and life support systems on future spacecraft. These results show that the WVX provides very uniform flow through flow channels for both the humid and dry streams. Measurements also show that CO2 diffusion through the water-permeable membranes will have negligible effect on the CO2 partial pressure in the spacecraft atmosphere.

  18. Development of a Microwave Regenerative Sorbent-Based Hydrogen Purifier

    Science.gov (United States)

    Wheeler, Richard R., Jr.; Dewberry, Ross H.; McCurry, Bryan D.; Abney, Morgan B.; Greenwood, Zachary W.

    2016-01-01

    This paper describes the design and fabrication of a Microwave Regenerative Sorbent-based Hydrogen Purifier (MRSHP). This unique microwave powered technology was developed for the purification of a hydrogen stream produced by the Plasma Pyrolysis Assembly (PPA). The PPA is a hydrogen recovery (from methane) post processor for NASA's Sabatier-based carbon dioxide reduction process. Embodied in the Carbon dioxide Reduction Assembly (CRA), currently aboard the International Space Station (ISS), the Sabatier reaction employs hydrogen to catalytically recover oxygen, in the form of water, from respiratory carbon dioxide produced by the crew. This same approach is base-lined for future service in the Air Revitalization system on extended missions into deep space where resupply is not practical. Accordingly, manned exploration to Mars may only become feasible with further closure of the air loop as afforded by the greater hydrogen recovery permitted by the PPA with subsequent hydrogen purification. By utilizing the well-known high sorbate loading capacity of molecular sieve 13x, coupled with microwave dielectric heating phenomenon, MRSHP technology is employed as a regenerative filter for a contaminated hydrogen gas stream. By design, freshly regenerated molecular sieve 13x contained in the MRSHP will remove contaminants from the effluent of a 1-CM scale PPA for several hours prior to breakthrough. By reversing flow and pulling a relative vacuum the MRSHP prototype then uses 2.45 GHz microwave power, applied through a novel coaxial antenna array, to rapidly heat the sorbent bed and drive off the contaminants in a short duration vacuum/thermal contaminant desorption step. Finally, following rapid cooling via room temperature cold plates, the MRSHP is again ready to serve as a hydrogen filter.

  19. 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

  20. Researches on regenerative medicine-current state and prospect.

    Science.gov (United States)

    Wang, Zheng-Guo; Xiao, Kai

    2012-01-01

    Since 1980s, the rapid development of tissue engineering and stem cell research has pushed regenerative medicine to a new fastigium, and regenerative medicine has become a noticeable research field in the international biology and medicine. In China, about 100 million patients need repair and regeneration treatment every year, while the number is much larger in the world. Regenerative medicine could provide effective salvation for these patients. Both Chinese Academy of Sciences and Chinese Academy of Engineering have made roadmaps of 2010-2050 and 2011-2030 for regenerative medicine. The final goal of the two roadmaps is to make China go up to leading position in most research aspects of regenerative medicine. In accord with this strategy, the government and some enterprises have invested 3-5 billion RMB (0.5-0.8 billion USD) for the research on regenerative medicine. In order to push the translation of regenerative medicine forward-from bench to bedside, a strategic alliance has been established, and it includes 27 top-level research institutes, medical institutes, colleges, universities and enterprises in the field of stem cell and regeneration medicine. Recently the journal, Science, has published a special issue-Regenerative Medicine in China, consisting of 35 papers dealing with stem cell and regeneration, tissue engineering and regeneration, trauma and regeneration and bases for tissue repair and regenerative medicine. It is predicated that a greater breakthrough in theory and practice of regenerative medicine will be achieved in the near future (20 to 30 years).

  1. Second row transition metal sulfides for the hydrotreatment of coal-derived naphtha. 1. Catalyst preparation, characterization and comparison of rate of simultaneous removal of total sulfur, nitrogen and oxygen

    Energy Technology Data Exchange (ETDEWEB)

    Raje, A.P.; Liaw, S.-J.; Srinivasan, R.; Davis, B.H. [University of Kentucky, Lexington, KY (United States). Center for Applied Energy Research

    1997-03-13

    Naphtha derived from an Illinois No. 6 coal contains appreciable quantities of sulfur-, nitrogen- and oxygen-containing compounds. The hydrotreatment of this naphtha was evaluated over unsupported transition metal sulfide catalysts (Ru, Rh, Mo, Pd, Zr, Mb). The catalysts were prepared by a room temperature precipitation reaction. Surface areas, crystalline phase and particle size distributions were determined by Brunauer-Emmet-Teller (BET), X-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. A comparison of average particle sizes calculated from these three techniques has enable the understanding of the morphology of the transition metal sulfides. The catalysts exhibit a so-called volcano plot for the HDS of dibenzothiophene. Similar so-called volcano plots are also exhibited for the simultaneous hydrodesulfurization (HDS), hydrodenitrogenation (HDN) and the hydrodeoxygenation (HDO) of the coal-derived naphtha containing a mixture of heteroatoms. The order of reactivity of the transition metal catalysts is the same for all three of the processes. Ruthenium sulfide is the most active catalyst for HDS, HDN and HDO of the coal-derived naphtha. 22 refs., 3 figs., 4 tabs.

  2. Economic feasibility of biochemical processes for the upgrading of crudes and the removal of sulfur, nitrogen, and trace metals from crude oil -- Benchmark cost establishment of biochemical processes on the basis of conventional downstream technologies. Final report FY95

    Energy Technology Data Exchange (ETDEWEB)

    Premuzic, E.T.

    1996-08-01

    During the past several years, a considerable amount of work has been carried out showing that microbially enhanced oil recovery (MEOR) is promising and the resulting biotechnology may be deliverable. At Brookhaven National Laboratory (BNL), systematic studies have been conducted which dealt with the effects of thermophilic and thermoadapted bacteria on the chemical and physical properties of selected types of crude oils at elevated temperatures and pressures. Current studies indicate that during the biotreatment several chemical and physical properties of crude oils are affected. The oils are (1) emulsified; (2) acidified; (3) there is a qualitative and quantitative change in light and heavy fractions of the crudes; (4) there are chemical changes in fractions containing sulfur compounds; (5) there is an apparent reduction in the concentration of trace metals; and (6) the qualitative and quantitative changes appear to be microbial species dependent; and (7) there is a distinction between biodegraded and biotreated oils. The downstream biotechnological crude oil processing research performed thus far is of laboratory scale and has focused on demonstrating the technical feasibility of downstream processing with different types of biocatalysts under a variety of processing conditions. Quantitative economic analysis is the topic of the present project which investigates the economic feasibility of the various biochemical downstream processes which hold promise in upgrading of heavy crudes, such as those found in California, e.g., Monterey-type, Midway Sunset, Honda crudes, and others.

  3. Micro-computed tomography (CT) based assessment of dental regenerative therapy in the canine mandible model

    Science.gov (United States)

    Khobragade, P.; Jain, A.; Setlur Nagesh, S. V.; Andreana, S.; Dziak, R.; Sunkara, S. K.; Sunkara, S.; Bednarek, D. R.; Rudin, S.; Ionita, C. N.

    2015-03-01

    High-resolution 3D bone-tissue structure measurements may provide information critical to the understanding of the bone regeneration processes and to the bone strength assessment. Tissue engineering studies rely on such nondestructive measurements to monitor bone graft regeneration area. In this study, we measured bone yield, fractal dimension and trabecular thickness through micro-CT slices for different grafts and controls. Eight canines underwent surgery to remove a bone volume (defect) in the canine's jaw at a total of 44 different locations. We kept 11 defects empty for control and filled the remaining ones with three regenerative materials; NanoGen (NG), a FDA-approved material (n=11), a novel NanoCalcium Sulfate (NCS) material (n=11) and NCS alginate (NCS+alg) material (n=11). After a minimum of four and eight weeks, the canines were sacrificed and the jaw samples were extracted. We used a custombuilt micro-CT system to acquire the data volume and developed software to measure the bone yield, fractal dimension and trabecular thickness. The software used a segmentation algorithm based on histograms derived from volumes of interest indicated by the operator. Using bone yield and fractal dimension as indices we are able to differentiate between the control and regenerative material (p<0.005). Regenerative material NCS showed an average 63.15% bone yield improvement over the control sample, NCS+alg showed 55.55% and NanoGen showed 37.5%. The bone regeneration process and quality of bone were dependent upon the position of defect and time period of healing. This study presents one of the first quantitative comparisons using non-destructive Micro-CT analysis for bone regenerative material in a large animal with a critical defect model. Our results indicate that Micro-CT measurement could be used to monitor invivo bone regeneration studies for greater regenerative process understanding.

  4. Recommendations for using regenerative endodontic procedures in permanent immature traumatized teeth.

    Science.gov (United States)

    Garcia-Godoy, Franklin; Murray, Peter E

    2012-02-01

    The regeneration of immature permanent teeth following trauma could be beneficial to reduce the risk of fracture and loss of millions of teeth each year. Regenerative endodontic procedures include revascularization, partial pulpotomy, and apexogenesis. Several case reports give these procedures a good prognosis as an alternative to apexification. Care is needed to deliver regenerative endodontic procedures that maintain or restore the vitality of teeth, but which also disinfect and remove necrotic tissues. Regeneration can be accomplished through the activity of the cells from the pulp, periodontium, vascular, and immune system. Most therapies use the host's own pulp or vascular cells for regeneration, but other types of dental stem cell therapies are under development. There are no standardized treatment protocols for endodontic regeneration. The purpose of this article is to review the recent literature and suggest guidelines for using regenerative endodontic procedures for the treatment of permanent immature traumatized teeth. Recommendations for the selection of regenerative and conventional procedures based on the type of tooth injury, fracture type, presence of necrosis or infection, periodontal status, presence of periapical lesions, stage of tooth development, vitality status, patient age, and patient health status will be reviewed. Because of the lack of long-term evidence to support the use of regenerative endodontic procedures in traumatized teeth with open apices, revascularization regeneration procedures should only be attempted if the tooth is not suitable for root canal obturation, and after apexogenesis, apexification, or partial pulpotomy treatments have already been attempted and have a poor prognosis. © 2011 John Wiley & Sons A/S.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-06-01

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

  6. New treating processes for sulfur-containing natural gases

    Energy Technology Data Exchange (ETDEWEB)

    Kislenko, N.; Aphanasiev, A.; Nabokov, S.; Ismailova, H. [VNIIGAS, Moscow (Russian Federation)

    1996-12-31

    The traditional method of removing H{sub 2}S from sour natural gases is first to treat the gas with a solvent and then to recover the H{sub 2}S from the sour stream in a Claus plant. This method recovers up to 97% of the sulfur when a three-stage Claus unit is employed. Amine/Claus units have operating difficulties for small sulfur capacities (up to 5 tons/day) because the operation of the fired equipment (reaction furnace) is much more difficult. Therefore, for small scale sulfur recovery plants redox processes which exhibit a significant reduction in investment and operating costs are normally used. Many different factors influence the choice of gas desulfurization technology--composition and gas flow, environmental sulfur recovery requirements and CO{sub 2}/H{sub 2}S ratio.

  7. 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

  8. Regenerative endodontic treatment for necrotic immature permanent premolar: A report of case

    Directory of Open Access Journals (Sweden)

    Sheetal B Ghivari

    2017-01-01

    Full Text Available Regenerative endodontic procedures provide new hope of converting nonvital tooth into vital once again. These potential regenerative approaches include root canal revascularization, postnatal stem-cell therapy, pulp implant, scaffold implant, three-dimensional cell printing, injectable scaffolds, and gene therapy. In this article, we describe successful revascularization treatment of necrotic permanent premolar tooth. Clinical and radiographic examination showed pulp involvement due to deep pit defect and periapical infection. Examination findings suggested revascularization treatment which was started with irrigation of canals using 1.25% of sodium hypochlorite and saline, followed by placement of 3-week dressing of triple antibiotic paste (ciprofloxacin, metronidazole, and minocycline. After removal of triple antibiotic paste blood clot was induced and mineral trioxide aggregate was placed on the blood clot followed by sealing the canal with glass ionomer cement. During radiographic and clinical follow-ups, the patient was asymptomatic and periapical lesion was healed, roots continued to develop, and root apex maturogenesis was complete.

  9. Regenerative Stem Cell Therapy for Breast Cancer Bone Metastasis

    Science.gov (United States)

    2015-11-01

    1 AD_________________ Award Number: W81XWH-11-1-0593 TITLE: Regenerative Stem Cell Therapy for Breast Cancer Bone Metastasis PRINCIPAL...3. DATES COVERED (From - To) 09/15/2011 - 08/14/2015 4. TITLE AND SUBTITLE Regenerative Stem Cell Therapy for Breast Cancer Bone Metastasis 5a...4 Title of the Grant: Regenerative Stem Cell Therapy for Breast Cancer Bone Metastasis Award number: W81XWH-11-1-0593 Principal Investigator

  10. Regenerative Endodontics: Barriers and Strategies for Clinical Translation

    OpenAIRE

    Kim, Sahng G.; Zhou, Jian; Ye, Ling; Cho, Shoko; Suzuki, Takahiro; Fu, Susan Y.; Yang, Rujing; Zhou, Xuedong; Mao, Jeremy J.

    2012-01-01

    Despite a great deal of enthusiasm and effort, regenerative endodontics has encountered substantial challenges towards clinical translation. Recent adoption by the American Dental Association (ADA) of evoked pulp bleeding in immature permanent teeth is an important step for regenerative endodontics. However, there is no regenerative therapy for the majority of endodontic diseases. Simple recapitulation of cell therapy and tissue engineering strategies that are under development for other orga...

  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. Regenerative Medicine Applications in Wound Care.

    Science.gov (United States)

    Nilforoushzadeh, Mohammad Ali; Sisakht, Mahsa Mollapour; Seifalian, Alexander Marcus; Amirkhani, Mohammad Amir; Banafshe, Hamid Reza; Verdi, Javad; Sharifzad, Farzaneh; Taghiabadi, Ehsan

    2017-01-01

    During the last two decades, a number of studies have been carried out on the application of regenerative medicine in the field of dermatology. The aim of this research was to critically review the application of regenerative medicine in the field of dermatology. The next aim was to look in depth to see whether regenerative medicine strategies have a place in the future of wound healing in a clinical setting. More specifically, to see if these strategies would apply for burns and non-healing diabetic wounds. Billions of dollars have been spent worldwide on research in wound treatment and skin regeneration. Although a high number of clinical trials show promising results, there is still no commercially available treatment for use. In addition, the outcome data from the clinical trials, taking place throughout the world, are not published in a standardized manner. Standardization within clinical trials is required for: protocols, outcome, endpoint values, and length of follow-up. The lack of standardization makes it much more difficult to compare the data collected and the different types of treatment. Despite several promising results from research and early phase clinical studies, the treatment for wounds as well as skin regeneration is still considered as an unmet clinical need. However, in the past three years, more promising research has been approaching clinical trials; this could be the solution that clinicians have been waiting for. This is a multibillion dollar industry for which there should be enough incentive for researchers and industry to seek the solution. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  13. Stem cells and the future of regenerative medicine

    National Research Council Canada - National Science Library

    National Research Council, Committee on the Biological and Biomedical Applications of Stem Cell Research; Commission on Life Sciences; National Research Council; Board on Life Sciences; Board on Neuroscience and Behavioral Health; Division on Earth and Life Studies; Institute of Medicine

    2002-01-01

    .... Stem Cells and the Future of Regenerative Medicine provides a deeper exploration of the biological, ethical, and funding questions prompted by the therapeutic potential of undifferentiated human cells...

  14. Platelet rich fibrin - a novel acumen into regenerative endodontic therapy

    Directory of Open Access Journals (Sweden)

    Kavita Hotwani

    2014-02-01

    Full Text Available Research into regenerative dentistry has added impetus onto the field of molecular biology. It can be documented as a prototype shift in the therapeutic armamentarium for dental disease. Regenerative endodontic procedures are widely being added to the current armamentarium of pulp therapy procedures. The regenerative potential of platelets has been deliberated. A new family of platelet concentrates called the platelet rich fibrin (PRF has been recently used by several investigators and has shown application in diverse disciplines of dentistry. This paper is intended to add light on the various prospects of PRF and clinical insights to regenerative endodontic therapy.

  15. Highly Efficient, Durable Regenerative Solid Oxide Stack, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Precision Combustion, Inc. (PCI) proposes to develop a highly efficient regenerative solid oxide stack design. Novel structural elements allow direct internal...

  16. 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...

  17. 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.

  18. Regenerative nanotechnology in oral and maxillofacial surgery.

    Science.gov (United States)

    Shakib, Kaveh; Tan, Aaron; Soskic, Vukic; Seifalian, Alexander M

    2014-12-01

    Regenerative nanotechnology is at the forefront of medical research, and translational medicine is a challenge to both scientists and clinicians. Although there has been an exponential rise in the volume of research generated about it for both medical and surgical uses, key questions remain about its actual benefits. Nevertheless, some people think that therapeutics based on its principles may form the core of applied research for the future. Here we give an account of its current use in oral and maxillofacial surgery, and implications and challenges for the future. Copyright © 2014 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  19. 3D Biomaterial Microarrays for Regenerative Medicine

    DEFF Research Database (Denmark)

    Gaharwar, Akhilesh K.; Arpanaei, Ayyoob; Andresen, Thomas Lars

    2015-01-01

    Three dimensional (3D) biomaterial microarrays hold enormous promise for regenerative medicine because of their ability to accelerate the design and fabrication of biomimetic materials. Such tissue-like biomaterials can provide an appropriate microenvironment for stimulating and controlling stem...... for tissue engineering and drug screening applications....... cell differentiation into tissue-specifi c lineages. The use of 3D biomaterial microarrays can, if optimized correctly, result in a more than 1000-fold reduction in biomaterials and cells consumption when engineering optimal materials combinations, which makes these miniaturized systems very attractive...

  20. Bioprinting is changing regenerative medicine forever.

    Science.gov (United States)

    Collins, Scott Forrest

    2014-12-01

    3D printing, or solid freeform fabrication, applied to regenerative medicine brings technologies from several industries together to help solve unique challenges in both basic science and tissue engineering. By more finely organizing cells and supporting structures precisely in 3D space, we will gain critical knowledge of cell-cell communications and cell-environment interactions. As we increase the scale, we will move toward complex tissue and organ structures where several cell phenotypes will functionally and structurally interact, thus recapitulating the form and function of native tissues and organs.

  1. Feasibility investigation of allogeneic endometrial regenerative cells

    Directory of Open Access Journals (Sweden)

    Reid Michael

    2009-02-01

    Full Text Available Abstract Endometrial Regenerative Cells (ERC are a population of mesenchymal-like stem cells having pluripotent differentiation activity and ability to induce neoangiogenesis. In vitro and animal studies suggest ERC are immune privileged and in certain situations actively suppress ongoing immune responses. In this paper we describe the production of clinical grade ERC and initial safety experiences in 4 patients with multiple sclerosis treated intravenously and intrathecally. The case with the longest follow up, of more than one year, revealed no immunological reactions or treatment associated adverse effects. These preliminary data suggest feasibility of clinical ERC administration and support further studies with this novel stem cell type.

  2. Phosphorous-Containing Polymers for Regenerative Medicine

    Science.gov (United States)

    Watson, Brendan M.; Kasper, F. Kurtis; Mikos, Antonios G.

    2014-01-01

    Disease and injury have resulted in a large, unmet need for functional tissue replacements. Polymeric scaffolds can be used to deliver cells and bioactive signals to address this need for regenerating damaged tissue. Phosphorous-containing polymers have been implemented to improve and accelerate the formation of native tissue both by mimicking the native role of phosphorous groups in the body and by attachment of other bioactive molecules. This manuscript reviews the synthesis, properties, and performance of phosphorous-containing polymers that can be useful in regenerative medicine applications. PMID:24565855

  3. MicroRNA Delivery for Regenerative Medicine

    OpenAIRE

    Peng, Bo; Chen, Yongming; Leong, Kam W.

    2015-01-01

    MicroRNA (miRNA) directs post-transcriptional regulation of a network of genes by targeting mRNA. Although relatively recent in development, many miRNAs direct differentiation of various stem cells including induced pluripotent stem cells (iPSCs), a major player in regenerative medicine. An effective and safe delivery of miRNA holds the key to translating miRNA technologies. Both viral and nonviral delivery systems have seen success in miRNA delivery, and each approach possesses advantages an...

  4. 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.

  5. Tissue engineering and regenerative medicine: manufacturing challenges.

    Science.gov (United States)

    Williams, D J; Sebastine, I M

    2005-12-01

    Tissue engineering and regenerative medicine are interdisciplinary fields that apply principles of engineering and life sciences to develop biological substitutes, typically composed of biological and synthetic components, that restore, maintain or improve tissue function. Many tissue engineering technologies are still at a laboratory or pre-commercial scale. The short review paper describes the most significant manufacturing and bio-process challenges inherent in the commercialisation and exploitation of the exciting results emerging from the biological and clinical laboratories exploring tissue engineering and regenerative medicine. A three-generation road map of the industry has been used to structure a view of these challenges and to define where the manufacturing community can contribute to the commercial success of the products from these emerging fields. The first-generation industry is characterised by its demonstrated clinical applications and products in the marketplace, the second is characterised by emerging clinical applications, and the third generation is characterised by aspirational clinical applications. The paper focuses on the cost reduction requirement of the first generation of the industry to allow more market penetration and consequent patient impact. It indicates the technological requirements, for instance the creation of three-dimensional tissue structures, and value chain issues in the second generation of the industry. The third-generation industry challenges lie in fundamental biological and clinical science. The paper sets out a road map of these generations to identify areas for research.

  6. Multiple excitation regenerative amplifier inertial confinement system

    International Nuclear Information System (INIS)

    George, V.E.; Haas, R.A.; Krupke, W.F.; Schlitt, L.G.

    1980-01-01

    The invention relates to apparatus and methods for producing high intensity laser radiation generation which is achieved through an optical amplifier-storage ring design. One or two synchronized, counterpropagating laser pulses are injected into a regenerative amplifier cavity and amplified by gain media which are pumped repetitively by electrical or optical means. The gain media excitation pulses are tailored to efficiently amplify the laser pulses during each transit. After the laser pulses have been amplified to the desired intensity level, they are either switched out of the cavity by some switch means, as for example an electro-optical device, for any well known laser end uses, or a target means may be injected into the regenerative amplifier cavity in such a way as to intercept simultaneously the counterpropagating laser pulses. One such well known end uses to which this invention is intended is for production of high density and temperature plasmas suitable for generating neutrons, ions and x-rays and for studying matter heated by high intensity laser radiation

  7. PRMT7 Preserves Satellite Cell Regenerative Capacity

    Directory of Open Access Journals (Sweden)

    Roméo Sébastien Blanc

    2016-02-01

    Full Text Available Regeneration of skeletal muscle requires the continued presence of quiescent muscle stem cells (satellite cells, which become activated in response to injury. Here, we report that whole-body protein arginine methyltransferase PRMT7−/− adult mice and mice conditionally lacking PRMT7 in satellite cells using Pax7-CreERT2 both display a significant reduction in satellite cell function, leading to defects in regenerative capacity upon muscle injury. We show that PRMT7 is preferentially expressed in activated satellite cells and, interestingly, PRMT7-deficient satellite cells undergo cell-cycle arrest and premature cellular senescence. These defects underlie poor satellite cell stem cell capacity to regenerate muscle and self-renew after injury. PRMT7-deficient satellite cells express elevated levels of the CDK inhibitor p21CIP1 and low levels of its repressor, DNMT3b. Restoration of DNMT3b in PRMT7-deficient cells rescues PRMT7-mediated senescence. Our findings define PRMT7 as a regulator of the DNMT3b/p21 axis required to maintain muscle stem cell regenerative capacity.

  8. Engineering growth factors for regenerative medicine applications.

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, Aaron C.; Briquez, Priscilla S.; Hubbell, Jeffrey A.; Cochran, Jennifer R.

    2016-01-15

    Growth factors are important morphogenetic proteins that instruct cell behavior and guide tissue repair and renewal. Although their therapeutic potential holds great promise in regenerative medicine applications, translation of growth factors into clinical treatments has been hindered by limitations including poor protein stability, low recombinant expression yield, and suboptimal efficacy. This review highlights current tools, technologies, and approaches to design integrated and effective growth factor-based therapies for regenerative medicine applications. The first section describes rational and combinatorial protein engineering approaches that have been utilized to improve growth factor stability, expression yield, biodistribution, and serum half-life, or alter their cell trafficking behavior or receptor binding affinity. The second section highlights elegant biomaterial-based systems, inspired by the natural extracellular matrix milieu, that have been developed for effective spatial and temporal delivery of growth factors to cell surface receptors. Although appearing distinct, these two approaches are highly complementary and involve principles of molecular design and engineering to be considered in parallel when developing optimal materials for clinical applications.

  9. Scaffolds in regenerative endodontics: A review

    Science.gov (United States)

    Gathani, Kinjal M.; Raghavendra, Srinidhi Surya

    2016-01-01

    Root canal therapy has enabled us to save numerous teeth over the years. The most desired outcome of endodontic treatment would be when diseased or nonvital pulp is replaced with healthy pulp tissue that would revitalize the teeth through regenerative endodontics. ‘A search was conducted using the Pubmed and MEDLINE databases for articles with the criteria ‘Platelet rich plasma’, ‘Platelet rich fibrin’, ‘Stem cells’, ‘Natural and artificial scaffolds’ from 1982–2015’. Tissues are organized as three-dimensional structures, and appropriate scaffolding is necessary to provide a spatially correct position of cell location and regulate differentiation, proliferation, or metabolism of the stem cells. Extracellular matrix molecules control the differentiation of stem cells, and an appropriate scaffold might selectively bind and localize cells, contain growth factors, and undergo biodegradation over time. Different scaffolds facilitate the regeneration of different tissues. To ensure a successful regenerative procedure, it is essential to have a thorough and precise knowledge about the suitable scaffold for the required tissue. This article gives a review on the different scaffolds providing an insight into the new developmental approaches on the horizon. PMID:27857762

  10. Liver regenerative medicine: advances and challenges.

    Science.gov (United States)

    Chistiakov, Dimitry A

    2012-01-01

    Liver transplantation is the standard care for many end-stage liver diseases. However, donor organs are scarce and some people succumb to liver failure before a donor is found. Liver regenerative medicine is a special interdisciplinary field of medicine focused on the development of new therapies incorporating stem cells, gene therapy and engineered tissues in order to repair or replace the damaged organ. In this review we consider the emerging progress achieved in the hepatic regenerative medicine within the last decade. The review starts with the characterization of liver organogenesis, fetal and adult stem/progenitor cells. Then, applications of primary hepatocytes, embryonic and adult (mesenchymal, hematopoietic and induced pluripotent) stem cells in cell therapy of liver diseases are considered. Current advances and challenges in producing mature hepatocytes from stem/progenitor cells are discussed. A section about hepatic tissue engineering includes consideration of synthetic and natural biomaterials in engineering scaffolds, strategies and achievements in the development of 3D bioactive matrices and 3D hepatocyte cultures, liver microengineering, generating bioartificial liver and prospects for fabrication of the bioengineered liver. Copyright © 2012 S. Karger AG, Basel.

  11. Advances in individualized and regenerative medicine.

    Science.gov (United States)

    Blum, Hubert E

    2014-03-01

    Molecular and cell biology have resulted in major advances in our understanding of disease pathogenesis as well as in novel strategies for the diagnosis, therapy and prevention of human diseases. Based on modern molecular, genetic and biochemical methodologies it is on the one hand possible to identify for example disease-related point mutations and single nucleotide polymorphisms. On the other hand, using high throughput array and other technologies, it is for example possible to simultaneously analyze thousands of genes or gene products (RNA and proteins), resulting in an individual gene or gene expression profile ('signature'). Such data increasingly allow to define the individual disposition for a given disease and to predict disease prognosis as well as the efficacy of therapeutic strategies in the individual patient ('individualized medicine'). At the same time, the basic discoveries in cell biology, including embryonic and adult stem cells, induced pluripotent stem cells, genetically modified cells and others, have moved regenerative medicine into the center of biomedical research worldwide with a major translational impact on tissue engineering as well as transplantation medicine. All these aspects have greatly contributed to the recent advances in regenerative medicine and the development novel concepts for the treatment of many human diseases, including liver diseases. Copyright © 2014 Medical University of Bialystok. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  12. Scaffolds in regenerative endodontics: A review

    Directory of Open Access Journals (Sweden)

    Kinjal M Gathani

    2016-01-01

    Full Text Available Root canal therapy has enabled us to save numerous teeth over the years. The most desired outcome of endodontic treatment would be when diseased or nonvital pulp is replaced with healthy pulp tissue that would revitalize the teeth through regenerative endodontics. ′A search was conducted using the Pubmed and MEDLINE databases for articles with the criteria ′Platelet rich plasma′, ′Platelet rich fibrin′, ′Stem cells′, ′Natural and artificial scaffolds′ from 1982-2015′. Tissues are organized as three-dimensional structures, and appropriate scaffolding is necessary to provide a spatially correct position of cell location and regulate differentiation, proliferation, or metabolism of the stem cells. Extracellular matrix molecules control the differentiation of stem cells, and an appropriate scaffold might selectively bind and localize cells, contain growth factors, and undergo biodegradation over time. Different scaffolds facilitate the regeneration of different tissues. To ensure a successful regenerative procedure, it is essential to have a thorough and precise knowledge about the suitable scaffold for the required tissue. This article gives a review on the different scaffolds providing an insight into the new developmental approaches on the horizon.

  13. Sulfur Amino Acids in Diet-induced Fatty Liver: A New Perspective Based on Recent Findings

    Directory of Open Access Journals (Sweden)

    John I. Toohey

    2014-06-01

    Full Text Available The relationship of sulfur amino acids to diet-induced fatty liver was established 80 years ago, with cystine promoting the condition and methionine preventing it. This relationship has renewed importance today because diet-induced fatty liver is relevant to the current epidemics of obesity, non-alcoholic fatty liver disease, metabolic syndrome, and type 2 diabetes. Two recent papers provide the first evidence linking sulfane sulfur to diet-induced fatty liver opening a new perspective on the problem. This review summarizes the early data on sulfur amino acids in fatty liver and correlates that data with current knowledge of sulfur metabolism. Evidence is reviewed showing that the lipotropic effect of methionine may be mediated by sulfane sulfur and that the hepatosteatogenic effect of cystine may be related to the removal of sulfane sulfur by cysteine catabolites. Possible preventive and therapeutic strategies are discussed.

  14. 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.

  15. 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.

  16. Electrolyte for batteries with regenerative solid electrolyte interface

    Science.gov (United States)

    Xiao, Jie; Lu, Dongping; Shao, Yuyan; Bennett, Wendy D.; Graff, Gordon L.; Liu, Jun; Zhang, Ji-Guang

    2017-08-01

    An energy storage device comprising: an anode; and a solute-containing electrolyte composition wherein the solute concentration in the electrolyte composition is sufficiently high to form a regenerative solid electrolyte interface layer on a surface of the anode only during charging of the energy storage device, wherein the regenerative layer comprises at least one solute or solvated solute from the electrolyte composition.

  17. Autonomous Operation of Super-Regenerative Receiver in BAN

    NARCIS (Netherlands)

    Kalyanasundaram, P.; Huang, L.; Dolmans, G.; Imamura, K.

    2012-01-01

    Super-regenerative receiver is one of the potential candidates to achieve ultra low power wireless communication in body area network (BAN). The main limitations of the super-regenerative receiver include the difficulty in choosing a good quench waveform to optimize its sensitivity and selectivity,

  18. Comparative energy analysis on a new regenerative Brayton cycle

    International Nuclear Information System (INIS)

    Goodarzi, M.

    2016-01-01

    Highlights: • New regenerative Brayton cycle has been introduced. • New cycle has higher thermal efficiency and lower exhausted heat per output power. • Regenerator may remain useful in the new cycle even at high pressure ratio. • New regenerative Brayton cycle is suggested for low pressure ratio operations. - Abstract: Gas turbines are frequently used for power generation. Brayton cycle is the basis for gas turbine operation and developing the alternative cycles. Regenerative Brayton cycle is a developed cycle for basic Brayton cycle with higher thermal efficiency at low to moderate pressure ratios. A new regenerative Brayton cycle has been introduced in the present study. Energy analysis has been conducted on ideal cycles to compare them from the first law of thermodynamics viewpoint. Comparative analyses showed that the new regenerative Brayton cycle has higher thermal efficiency than the original one at the same pressure ratio, and also lower heat absorption and exhausted heat per unite output power. Computed results show that new cycle improves thermal efficiency from 12% to 26% relative to the original regenerative Brayton cycle in the range of studied pressure ratios. Contrary to the original regenerative Brayton cycle, regenerator remains useful in the new regenerative Brayton cycle even at higher pressure ratio.

  19. 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

  20. 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...

  1. Histologic Outcomes of Uninfected Human Immature Teeth Treated with Regenerative Endodontics: 2 Case Reports.

    Science.gov (United States)

    Nosrat, Ali; Kolahdouzan, Alireza; Hosseini, Farzaneh; Mehrizi, Ehsan A; Verma, Prashant; Torabinejad, Mahmoud

    2015-10-01

    A growing body of evidence exists showing the possibility of growing vital tissues in the root canal spaces of teeth with necrotic pulps and open apices. However, there is very limited histologic information regarding characteristics of tissues formed in the root canal space of human teeth after regenerative endodontics. The aim of this study was to examine clinically and histologically the outcomes of human immature teeth treated with regenerative endodontics. Two healthy birooted human maxillary first premolar teeth scheduled for extraction were included. Preoperative radiographs confirmed that these teeth had immature apices. Vitality tests showed the presence of vital pulps in these teeth. After receiving consent forms, the teeth were isolated with a rubber dam, and the pulps were completely removed. After the formation of blood clots in the canals, the teeth were covered with mineral trioxide aggregate. Four months later, the teeth were clinically and radiographically evaluated, extracted, and examined histologically. Both patients remained asymptomatic after treatment. Radiographic examination of the teeth showed signs of root development after treatment. Histologic examination of tissues growing into the root canal space of these teeth shows the presence of connective tissue, bone and cementum formation, and thickening of roots. Based on our findings, it appears that when canals of teeth with open apices are treated with regenerative endodontics, tissues of the periodontium grow into the root canals of these teeth. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  2. Solar Airplanes and Regenerative Fuel Cells

    Science.gov (United States)

    Bents, David J.

    2007-01-01

    A solar electric aircraft with the potential to "fly forever" has captured NASA's interest, and the concept for such an aircraft was pursued under Aeronautics Environmental Research Aircraft and Sensor Technology (ERAST) project. Feasibility of this aircraft happens to depend on the successful development of solar power technologies critical to NASA's Exploration Initiatives; hence, there was widespread interest throughout NASA to bring these technologies to a flight demonstration. The most critical is an energy storage system to sustain mission power during night periods. For the solar airplane, whose flight capability is already limited by the diffuse nature of solar flux and subject to latitude and time of year constraints, the feasibility of long endurance flight depends on a storage density figure of merit better than 400-600 watt-hr per kilogram. This figure of merit is beyond the capability of present day storage technologies (other than nuclear) but may be achievable in the hydrogen-oxygen regenerative fuel cell (RFC). This potential has led NASA to undertake the practical development of a hydrogen-oxygen regenerative fuel cell, initially as solar energy storage for a high altitude UAV science platform but eventually to serve as the primary power source for NASAs lunar base and other planet surface installations. Potentially the highest storage capacity and lowest weight of any non-nuclear device, a flight-weight RFC aboard a solar-electric aircraft that is flown continuously through several successive day-night cycles will provide the most convincing demonstration that this technology's widespread potential has been realized. In 1998 NASA began development of a closed cycle hydrogen oxygen PEM RFC under the Aeronautics Environmental Research Aircraft and Sensor Technology (ERAST) project and continued its development, originally for a solar electric airplane flight, through FY2005 under the Low Emissions Alternative Power (LEAP) project. Construction of

  3. 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.

  4. 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.

  5. Enantioselctive Syntheses of Sulfur Analogues of Flavan-3-Ols

    Directory of Open Access Journals (Sweden)

    Richard Lombardy

    2010-08-01

    Full Text Available The first enantioselective syntheses of sulfur flavan-3-ol analogues 1–8 have been accomplished, whereby the oxygen atom of the pyran ring has been replaced by a sulfur atom. The key steps were: (a Pd(0 catalyzed introduction of –S t-butyl group, (b Sharpless enantioselective dihydroxylation of the alkene, (c acid catalyzed ring closure to produce the thiopyran ring, and (d removal of benzyl groups using N,N-dimethylaniline and AlCl3. The compounds were isolated in high chemical and optical purity.

  6. Degradation of sulfur dioxide using plasma technology

    International Nuclear Information System (INIS)

    Estrada M, N.; Garcia E, R.; Pacheco P, M.; Valdivia B, R.; Pacheco S, J.

    2013-01-01

    This paper presents the electro-chemical study performed for sulfur dioxide (SO 2 ) treatment using non thermal plasma coupled to a nano structured fluid bed enhancing the toxic gas removal and the adsorption of acids formed during plasma treatment, more of 80% of removal was obtained. Non thermal plasma was ignited by dielectric barrier discharge (Dbd). The research was developed through an analysis of the chemical kinetics of the process and experimental study of degradation; in each experiment the electrical parameters and the influence of carbon nano structures were monitored to establish the optimal conditions of degradation. We compared the theoretical and experimental results to conclude whether the proposed model is correct for degradation. (Author)

  7. New tools in regenerative medicine: gene therapy.

    Science.gov (United States)

    Muñoz Ruiz, Miguel; Regueiro, José R

    2012-01-01

    Gene therapy aims to transfer genetic material into cells to provide them with new functions. A gene transfer agent has to be safe, capable of expressing the desired gene for a sustained period of time in a sufficiently large population of cells to produce a biological effect. Identifying a gene transfer tool that meets all of these criteria has proven to be a difficult objective. Viral and nonviral vectors, in vivo, ex vivo and in situ strategies co-exist at present, although ex vivo lenti-or retroviral vectors are presently the most popular.Natural stem cells (from embryonic, hematopoietic, mesenchymal, or adult tissues) or induced progenitor stem (iPS) cells can be modified by gene therapy for use in regenerative medicine. Among them, hematopoietic stem cells have shown clear clinical benefit, but iPS cells hold humongous potential with no ethical concerns.

  8. A regenerative approach towards mucosal fenestration closure

    Science.gov (United States)

    Gandi, Padma; Anumala, Naveen; Reddy, Amarender; Viswa Chandra, Rampalli

    2013-01-01

    Mucosal fenestration is an opening or an interstice through the oral mucosa. A lesion which occurs with greater frequency than generally realised, its occurrence is attributed to a myriad of causes. Mucogingival procedures including connective tissue grafts, free gingival grafts and lateral pedicle grafts are generally considered to be the treatment of choice in the closure of a mucosal fenestration. More often, these procedures are performed in conjunction with other procedures such as periradicular surgery and with bone grafts. However, the concomitant use of gingival grafts and bone grafts in mucosal fenestrations secondary to infections in sites exhibiting severe bone loss is highly debatable. In this article, we report two cases of mucosal fenestrations secondary to trauma and their management by regenerative periodontal surgery with the placement of guided tissue regeneration membrane and bone graft. The final outcome was a complete closure of the fenestration in both the cases. PMID:23749826

  9. A regenerative zinc-air fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Smedley, Stuart I. [Electrochemical Technology Development Ltd., Lower Hutt (New Zealand); Zhang, X. Gregory [Teck Cominco Metals Ltd., 2380 Speakman Drive, Mississauga, Ontario (Canada)

    2007-03-20

    The zinc regenerative fuel cell (ZRFC) developed by the former Metallic Power Inc. over the period from 1998 to 2004 is described. The component technologies and engineering solutions for various technical issues are discussed in relation to their functionality in the system. The system was designed to serve as a source of backup emergency power for remote or difficult to access cell phone towers during periods when the main power was interrupted. It contained a 12 cell stack providing 1.8 kW, a separate fuel tank containing zinc pellet fuel and electrolyte, and a zinc electrolyzer to regenerate the zinc pellets during standby periods. Offsite commissioning and testing of the system was successfully performed. The intellectual property of the ZRFC technology is now owned by Teck Cominco Metals Ltd. (author)

  10. Why regenerative medicine needs an extracellular matrix.

    Science.gov (United States)

    Prestwich, Glenn D; Healy, Kevin E

    2015-01-01

    Regenerative medicine is now coming of age. Many attempts at cell therapy have failed to show significant efficacy, and the umbrella term 'stem cell therapy' is perceived in some quarters as hype or just expensive and unnecessary medical tourism. Here we present a short editorial in three parts. First, we examine the importance of using a semisynthetic extracellular matrix (ECM) mimetic, or sECM, to deliver and retain therapeutic cells at the site of administration. Second, we describe one approach in which biophysical and biochemical properties are tailored to each tissue type, which we call "design for optimal functionality." Third, we describe an alternative approach to sECM design and implementation, called "design for simplicity," in which a deconstructed, minimalist sECM is employed and biology is allowed to perform the customization in situ. We opine that an sECM, whether minimal or instructive, is an essential contributor to improve the outcomes of cell-based therapies.

  11. Genetic engineering for skeletal regenerative medicine.

    Science.gov (United States)

    Gersbach, Charles A; Phillips, Jennifer E; García, Andrés J

    2007-01-01

    The clinical challenges of skeletal regenerative medicine have motivated significant advances in cellular and tissue engineering in recent years. In particular, advances in molecular biology have provided the tools necessary for the design of gene-based strategies for skeletal tissue repair. Consequently, genetic engineering has emerged as a promising method to address the need for sustained and robust cellular differentiation and extracellular matrix production. As a result, gene therapy has been established as a conventional approach to enhance cellular activities for skeletal tissue repair. Recent literature clearly demonstrates that genetic engineering is a principal factor in constructing effective methods for tissue engineering approaches to bone, cartilage, and connective tissue regeneration. This review highlights this literature, including advances in the development of efficacious gene carriers, novel cell sources, successful delivery strategies, and optimal target genes. The current status of the field and the challenges impeding the clinical realization of these approaches are also discussed.

  12. Tissue Engineering in Regenerative Dental Therapy

    Directory of Open Access Journals (Sweden)

    Hiral Jhaveri-Desai

    2011-01-01

    Full Text Available Tissue engineering is amongst the latest exciting technologies having impacted the field of dentistry. Initially considered as a futuristic approach, tissue engineering is now being successfully applied in regenerative surgery. This article reviews the important determinants of tissue engineering and how they contribute to the improvement of wound healing and surgical outcomes in the oral region. Furthermore, we shall address the clinical applications of engineering involving oral and maxillofacial surgical and periodontal procedures along with other concepts that are still in experimental phase of development. This knowledge will aid the surgical and engineering researchers to comprehend the collaboration between these fields leading to extounding dental applications and to ever-continuing man-made miracles in the field of human science.

  13. Regenerative immunology: the immunological reaction to biomaterials.

    Science.gov (United States)

    Cravedi, Paolo; Farouk, Samira; Angeletti, Andrea; Edgar, Lauren; Tamburrini, Riccardo; Duisit, Jerome; Perin, Laura; Orlando, Giuseppe

    2017-12-01

    Regenerative medicine promises to meet two of the most urgent needs of modern organ transplantation, namely immunosuppression-free transplantation and an inexhaustible source of organs. Ideally, bioengineered organs would be manufactured from a patient's own biomaterials-both cells and the supporting scaffolding materials in which cells would be embedded and allowed to mature to eventually regenerate the organ in question. While some groups are focusing on the feasibility of this approach, few are focusing on the immunogenicity of the scaffolds that are being developed for organ bioengineering purposes. This review will succinctly discuss progress in the understanding of immunological characteristics and behavior of different scaffolds currently under development, with emphasis on the extracellular matrix scaffolds obtained decellularized animal or human organs which seem to provide the ideal template for bioengineering purposes. © 2017 Steunstichting ESOT.

  14. ADRES : autonomous decentralized regenerative energy systems

    Energy Technology Data Exchange (ETDEWEB)

    Brauner, G.; Einfalt, A.; Leitinger, C.; Tiefgraber, D. [Vienna Univ. of Technology (Austria)

    2007-07-01

    The autonomous decentralized regenerative energy systems (ADRES) research project demonstrates that decentralized network independent microgrids are the target power systems of the future. This paper presented a typical structure of a microgrid, demonstrating that all types of generation available can be integrated, from wind and small hydro to photovoltaic, fuel cell, biomass or biogas operated stirling motors and micro turbines. In grid connected operation the balancing energy and reactive power for voltage control will come from the public grid. If there is no interconnection to a superior grid, it will form an autonomous micro grid. In order to reduce peak power demand and base energy, autonomous microgrid technology requires highly efficient appliances. Otherwise large collector design, high storage and balancing generation capacities would be necessary, which would increase costs. End-use energy efficiency was discussed with reference to demand side management (DSM) strategies that match energy demand with actual supply in order to minimize the storage size needed. This paper also discussed network controls that comprise active and reactive power. Decentralized robust algorithms were investigated with reference to black-start ability and congestion management features. It was concluded that the trend to develop small decentralized grids in parallel to existing large systems will improve security of supply and reduce greenhouse gas emissions. Decentralized grids will also increase energy efficiency because regenerative energy will be used where it is collected in the form of electricity and heat, thus avoiding transport and the extension of transmission lines. Decentralized energy technology is now becoming more economic by efficient and economic mass production of components. Although decentralized energy technology requires energy automation, computer intelligence is becoming increasingly cost efficient. 2 refs., 4 figs.

  15. The TMI Regenerative Solid Oxide Fuel Cell

    Science.gov (United States)

    Cable, Thomas L.; Ruhl, Robert C.; Petrik, Michael

    1996-01-01

    Energy storage and production in space requires rugged, reliable hardware which minimizes weight, volume, and maintenance while maximizing power output and usable energy storage. Systems generally consist of photovoltaic solar arrays which operate (during sunlight cycles) to provide system power and regenerate fuel (hydrogen) via water electrolysis and (during dark cycles) fuel cells convert hydrogen into electricity. Common configurations use two separate systems (fuel cell and electrolyzer) in conjunction with photovoltaic cells. Reliability, power to weight and power to volume ratios could be greatly improved if both power production (fuel cells) and power storage (electrolysis) functions can be integrated into a single unit. The solid oxide fuel cell (SOFC) based design integrates fuel cell and electrolyzer functions and potentially simplifies system requirements. The integrated fuel cell/electrolyzer design also utilizes innovative gas storage concepts and operates like a rechargeable 'hydrogen-oxygen battery'. Preliminary research has been completed on improved H2/H20 electrode (SOFC anode/electrolyzer cathode) materials for regenerative fuel cells. Tests have shown improved cell performance in both fuel and electrolysis modes in reversible fuel cell tests. Regenerative fuel cell efficiencies, ratio of power out (fuel cell mode) to power in (electrolyzer mode), improved from 50 percent using conventional electrode materials to over 80 percent. The new materials will allow a single SOFC system to operate as both the electolyzer and fuel cell. Preliminary system designs have also been developed to show the technical feasibility of using the design for space applications requiring high energy storage efficiencies and high specific energy. Small space systems also have potential for dual-use, terrestrial applications.

  16. Heat cascading regenerative sorption heat pump

    Science.gov (United States)

    Jones, Jack A. (Inventor)

    1995-01-01

    A simple heat cascading regenerative sorption heat pump process with rejected or waste heat from a higher temperature chemisorption circuit (HTCC) powering a lower temperature physisorption circuit (LTPC) which provides a 30% total improvement over simple regenerative physisorption compression heat pumps when ammonia is both the chemisorbate and physisorbate, and a total improvement of 50% or more for LTPC having two pressure stages. The HTCC contains ammonia and a chemisorbent therefor contained in a plurality of canisters, a condenser-evaporator-radiator system, and a heater, operatively connected together. The LTPC contains ammonia and a physisorbent therefor contained in a plurality of compressors, a condenser-evaporator-radiator system, operatively connected together. A closed heat transfer circuit (CHTC) is provided which contains a flowing heat transfer liquid (FHTL) in thermal communication with each canister and each compressor for cascading heat from the HTCC to the LTPC. Heat is regenerated within the LTPC by transferring heat from one compressor to another. In one embodiment the regeneration is performed by another CHTC containing another FHTL in thermal communication with each compressor. In another embodiment the HTCC powers a lower temperature ammonia water absorption circuit (LTAWAC) which contains a generator-absorber system containing the absorbent, and a condenser-evaporator-radiator system, operatively connected together. The absorbent is water or an absorbent aqueous solution. A CHTC is provided which contains a FHTL in thermal communication with the generator for cascading heat from the HTCC to the LTAWAC. Heat is regenerated within the LTAWAC by transferring heat from the generator to the absorber. The chemical composition of the chemisorbent is different than the chemical composition of the physisorbent, and the absorbent. The chemical composition of the FHTL is different than the chemisorbent, the physisorbent, the absorbent, and ammonia.

  17. Removal of nitrogen from anaerobically digested swine wastewater ...

    African Journals Online (AJOL)

    This result indicates that the sulfur-packed biofilter would be used as an efficient option for denitrification by autotrophic denitrifiers during swine wastewater treatment. Key words: Biological nitrogen removal, nitrification, denitrification, chemical oxygen demand (COD), intermittent aeration, sulfur-packed bed reactor, swine ...

  18. Danburite decomposition by sulfuric acid

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  19. A survey of dental residents' expectations for regenerative endodontics.

    Science.gov (United States)

    Manguno, Christine; Murray, Peter E; Howard, Cameron; Madras, Jonathan; Mangan, Stephen; Namerow, Kenneth N

    2012-02-01

    The objective was to survey a group of dental residents regarding their expectations for using regenerative endodontic procedures as part of future dental treatments. After institutional review board approval, the opinions of 32 dentists who were having postgraduate residency training to become specialists in a dental school were surveyed. The survey had 40 questions about professional status, ethical beliefs, judgment, and clinical practice. It was found that 83.9% of dentists had no continuing education or training in stem cells or regenerative endodontic procedures. Results showed that 96.8% of dentists are willing to receive training to be able to provide regenerative endodontic procedures for their patients. Of the total group, 49.1% of dentists already use membranes, scaffolds, or bioactive materials to provide dental treatment. It was determined that 47.3% of dentists agree that the costs of regenerative procedures should be comparable with current treatments. It was also found that 55.1% of dentists were unsure whether regenerative procedures would be successful. Dentists are supportive of using regenerative endodontic procedures in their dental practice, and they are willing to undergo extra training and to buy new technology to provide new procedures. Nevertheless, dentists also need more evidence for the effectiveness and safety of regenerative treatments before they will be recommended for most patients. Copyright © 2012. Published by Elsevier Inc.

  20. A review of the regenerative endodontic treatment procedure

    Directory of Open Access Journals (Sweden)

    Bin-Na Lee,

    2015-08-01

    Full Text Available Traditionally, apexification has been used to treat immature permanent teeth that have lost pulp vitality. This technique promotes the formation of an apical barrier to close the open apex so that the filling materials can be confined to the root canal. Because tissue regeneration cannot be achieved with apexification, a new technique called regenerative endodontic treatment was presented recently to treat immature permanent teeth. Regenerative endodontic treatment is a treatment procedure designed to replace damaged pulp tissue with viable tissue which restores the normal function of the pulp-dentin structure. After regenerative endodontic treatment, continued root development and hard tissue deposition on the dentinal wall can occur under ideal circumstances. However, it is difficult to predict the result of regenerative endodontic treatment. Therefore, the purpose of this study was to summarize multiple factors effects on the result of regenerative endodontic treatment in order to achieve more predictable results. In this study, we investigated the features of regenerative endodontic treatment in comparison with those of other pulp treatment procedures and analyzed the factors that have an effect on regenerative endodontic treatment.

  1. Hair Removal

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Hair Removal KidsHealth / For Teens / Hair Removal What's in ... you need any of them? Different Types of Hair Before removing hair, it helps to know about ...

  2. Vanadium Extraction from Shale via Sulfuric Acid Baking and Leaching

    Science.gov (United States)

    Shi, Qihua; Zhang, Yimin; Liu, Tao; Huang, Jing

    2018-01-01

    Fluorides are widely used to improve vanadium extraction from shale in China. Sulfuric acid baking-leaching (SABL) was investigated as a means of recovering vanadium which does not require the use of fluorides and avoids the productions of harmful fluoride-containing wastewater. Various effective factors were systematically studied and the experimental results showed that 90.1% vanadium could be leached from the shale. On the basis of phase transformations and structural changes after baking the shale, a mechanism of vanadium extraction from shale via SABL was proposed. The mechanism can be described as: (1) sulfuric acid diffusion into particles; (2) the formation of concentrated sulfuric acid media in the particles after water evaporation; (3) hydroxyl groups in the muscovite were removed and transient state [SO4 2-] was generated; and (4) the metals in the muscovite were sulfated by active [SO4 2-] and the vanadium was released. Thermodynamics modeling confirmed this mechanism.

  3. Adaptive controller for regenerative and friction braking system

    Science.gov (United States)

    Davis, Roy I.

    1990-01-01

    A regenerative and friction braking system for a vehicle having one or more roadwheels driven by an electric traction motor includes a driver responsive device for producing a brake demand signal having a magnitude corresponding to the level of braking force selected by the driver and friction and regenerative brakes operatively connected with the roadwheels of the vehicle. A system according to this invention further includes control means for operating the friction and regenerative braking subsystems so that maximum brake torques sustainable by the roadwheels of the vehicle without skidding or slipping will not be exceeded.

  4. The past, present and future of ligament regenerative engineering.

    Science.gov (United States)

    Mengsteab, Paulos Y; Nair, Lakshmi S; Laurencin, Cato T

    2016-12-01

    Regenerative engineering has been defined as the convergence of Advanced Materials Sciences, Stem Cell Sciences, Physics, Developmental Biology and Clinical Translation for the regeneration of complex tissues and organ systems. Anterior cruciate ligament (ACL) reconstruction necessitates the regeneration of bone, ligament and their interface to achieve superior clinical results. In the past, the ACL has been repaired with the use of autologous and allogeneic grafts, which have their respective drawbacks. Currently, investigations on the use of biodegradable matrices to achieve knee stability and permit tissue regeneration are making promising advancements. In the future, utilizing regenerative biology cues to induce an endogenous regenerative response may aid the enhancement of clinical ACL reconstruction outcomes.

  5. Regenerative endodontics: barriers and strategies for clinical translation.

    Science.gov (United States)

    Mao, Jeremy J; Kim, Sahng G; Zhou, Jian; Ye, Ling; Cho, Shoko; Suzuki, Takahiro; Fu, Susan Y; Yang, Rujing; Zhou, Xuedong

    2012-07-01

    Regenerative endodontics has encountered substantial challenges toward clinical translation. The adoption by the American Dental Association of evoked pulp bleeding in immature permanent teeth is an important step for regenerative endodontics. However, there is no regenerative therapy for most endodontic diseases. Simple recapitulation of cell therapy and tissue engineering strategies that are under development for other organ systems has not led to clinical translation in regeneration endodontics. Recent work using novel biomaterial scaffolds and growth factors that orchestrate the homing of host endogenous cells represents a departure from traditional cell transplantation approaches and may accelerate clinical translation. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. Biomolecule delivery to engineer the cellular microenvironment for regenerative medicine.

    Science.gov (United States)

    Bishop, Corey J; Kim, Jayoung; Green, Jordan J

    2014-07-01

    To realize the potential of regenerative medicine, controlling the delivery of biomolecules in the cellular microenvironment is important as these factors control cell fate. Controlled delivery for tissue engineering and regenerative medicine often requires bioengineered materials and cells capable of spatiotemporal modulation of biomolecule release and presentation. This review discusses biomolecule delivery from the outside of the cell inwards through the delivery of soluble and insoluble biomolecules as well as from the inside of the cell outwards through gene transfer. Ex vivo and in vivo therapeutic strategies are discussed, as well as combination delivery of biomolecules, scaffolds, and cells. Various applications in regenerative medicine are highlighted including bone tissue engineering and wound healing.

  7. FURNACE INJECTION OF ALKALINE SORBENTS FOR SULFURIC ACID CONTROL; SEMIANNUAL

    International Nuclear Information System (INIS)

    Gary M. Blythe

    2002-01-01

    This document summarizes progress on Cooperative Agreement DE-FC26-99FT40718, Furnace Injection of Alkaline Sorbents for Sulfuric Acid Control, during the time period October 1, 2001 through March 31, 2002. The objective of this project is to demonstrate the use of alkaline reagents injected into the furnace of coal-fired boilers as a means of controlling sulfuric acid emissions. The coincident removal of hydrochloric acid and hydrofluoric acid is also being determined, as is the removal of arsenic, a known poison for NO(sub X) selective catalytic reduction (SCR) catalysts. EPRI, the Tennessee Valley Authority (TVA), FirstEnergy Corporation, American Electric Power (AEP) and the Dravo Lime Company are project co-funders. URS Corporation is the prime contractor. This is the fifth reporting period for the subject Cooperative Agreement. During the previous (fourth) period, two long-term sorbent injection tests were conducted, one on Unit 3 at FirstEnergy's Bruce Mansfield Plant (BMP) and one on Unit 1 at AEP's Gavin Plant. Those tests determined the effectiveness of injecting alkaline slurries into the upper furnace of the boiler as a means of controlling sulfuric acid emissions from these units. The alkaline slurries tested included commercially available magnesium hydroxide slurry (Gavin Plant) and a byproduct magnesium hydroxide slurry (at both Gavin and BMP). The tests showed that injecting either the commercial or the byproduct magnesium hydroxide slurry could achieve up to 70-75% overall sulfuric acid removal. At BMP, the overall removal was limited by the need to maintain acceptable electrostatic precipitator (ESP) particulate control performance. At Gavin Plant, the overall sulfuric acid removal was limited because the furnace injected sorbent was less effective at removing SO(sub 3) formed across the SCR system installed on the unit for NO(sub X) control than at removing SO(sub 3) formed in the furnace. The SO(sub 3) removal results were presented in the

  8. New Regenerative Cycle for Vapor Compression Refrigeration

    Energy Technology Data Exchange (ETDEWEB)

    Mark J. Bergander

    2005-08-29

    The main objective of this project is to confirm on a well-instrumented prototype the theoretically derived claims of higher efficiency and coefficient of performance for geothermal heat pumps based on a new regenerative thermodynamic cycle as comparing to existing technology. In order to demonstrate the improved performance of the prototype, it will be compared to published parameters of commercially available geothermal heat pumps manufactured by US and foreign companies. Other objectives are to optimize the design parameters and to determine the economic viability of the new technology. Background (as stated in the proposal): The proposed technology closely relates to EERE mission by improving energy efficiency, bringing clean, reliable and affordable heating and cooling to the residential and commercial buildings and reducing greenhouse gases emission. It can provide the same amount of heating and cooling with considerably less use of electrical energy and consequently has a potential of reducing our nations dependence on foreign oil. The theoretical basis for the proposed thermodynamic cycle was previously developed and was originally called a dynamic equilibrium method. This theory considers the dynamic equations of state of the working fluid and proposes the methods for modification of T-S trajectories of adiabatic transformation by changing dynamic properties of gas, such as flow rate, speed and acceleration. The substance of this proposal is a thermodynamic cycle characterized by the regenerative use of the potential energy of two-phase flow expansion, which in traditional systems is lost in expansion valves. The essential new features of the process are: (1) The application of two-step throttling of the working fluid and two-step compression of its vapor phase. (2) Use of a compressor as the initial step compression and a jet device as a second step, where throttling and compression are combined. (3) Controlled ratio of a working fluid at the first and

  9. Selective adsorption of refractory sulfur species on active carbons and carbon based CoMo catalyst.

    Science.gov (United States)

    Farag, Hamdy

    2007-03-01

    Adsorption technique could be a reliable alternative in removing to a certain remarkable extent the sulfur species from the feedstock of petroleum oil. The performance of various carbons on adsorption of model sulfur compounds in a simulated feed solution and the sulfur containing compounds in the real gas oil was evaluated. The adsorption experiments have been carried out in a batch scale at ambient temperature and under the atmospheric pressure. In general, the most refractory sulfur compounds in the hydrotreatment reactions were selectively removed and adsorbed. It was found that the adsorbents affinities to dibenzothiophene and 4,6-dimethyldibenzothiophene were much more favored and pronounced than the aromatic matrices like fluorene, 1-methylnaphthalene and 9-methylanthracene. Among the sulfur species, 4,6-dimethyldibenzothiophene was the highest to be removed in terms of both selectivity and capacity over all the present adsorbents. The studied adsorbents showed significant capacities for the polyaromatic thiophenes. The electronic characteristics seem to play a certain role in such behavior. Regeneration of the used adsorbent was successfully attained either by washing it with toluene or by the release of the adsorbates through heat treatment. A suggested adsorptive removal process of sulfur compounds from petroleum distillate over carbon supported CoMo catalyst was discussed.

  10. Desulfurisation and sulfur recovery

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, P.; Finn, A.; Scott, L. [Costain Oil, Gas and Process Ltd (United Kingdom)

    2001-09-01

    This article highlights technical issues associated with different sulphur recovery processes in the hydrocarbon processing industry. Details are given of the Stretford process developed by British Gas for the removal of low concentrations of hydrogen sulphide from natural gas and other hydrocarbon gases; the SulFerox process developed by Shell and Dow for removing moderate amounts of sulphur from contaminated gases using a proprietary iron salt for extracting the sulphur; solvent systems for removing moderately high concentrations of hydrogen sulphide in sour gas or liquid petroleum gases (LPG); the simple Claus process involving the partial combustion of hydrogen sulphide forming sulphur dioxide which reacts with hydrogen sulphide to form sulphur; and enhanced Claus processes. Sour water stripping processes for hydrogen sulphide contaminated water from hydrocarbon processing, tail gas treatment of Claus plant offgases, and hydrotreating are also discussed.

  11. Electrolyzer for NASA Lunar Regenerative Fuel Cells, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Water electrolyzer stacks are a key component of regenerative fuel cells, designed to replace batteries as a means of storing electric energy on the lunar surface....

  12. Regenerative medicine: A ray of light for medical science

    Directory of Open Access Journals (Sweden)

    Swapna Supekar

    2016-01-01

    Full Text Available The perimeters of medical science have expanded to include regenerative medicine as a translational science, which has the potential to revolutionize the treatment of incapacitating diseases and chronic disorders.

  13. LOX/Methane Regeneratively-Cooled Rocket Engine Development

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of this project is to advance the technologies required to build a subcritical regeneratively cooled liquid oxygen/methane rocket combustion chamber for...

  14. Conference Report: 6th Annual International Symposium on Regenerative Rehabilitation.

    Science.gov (United States)

    Loghmani, M Terry; Roche, Joseph A

    2018-04-03

    The 6th International Symposium on Regenerative Rehabilitation, hosted by the Alliance for Regenerative Rehabilitation Research and Training (AR 3 T), included a preconference meeting of institutional representatives of the International Consortium of Regenerative Rehabilitation, keynote talks from distinguished scientists, platform and poster presentations from experts and trainees, panel discussions and postconference workshops. The following priorities were identified: increasing rigor in basic, preclinical and clinical studies, especially the use of better controls; developing better outcome measures for preclinical and clinical trials; focusing on developing more tissue-based interventions versus cell-based interventions; including regenerative rehabilitation in curricula of professional programs like occupational and physical therapy; and developing better instruments to quantify rehabilitative interventions.

  15. Advancing pig cloning technologies towards application in regenerative medicine.

    Science.gov (United States)

    Nagashima, H; Matsunari, H; Nakano, K; Watanabe, M; Umeyama, K; Nagaya, M

    2012-08-01

    Regenerative medicine is expected to make a significant contribution by development of novel therapeutic treatments for intractable diseases and for improving the quality of life of patients. Many advances in regenerative medicine, including basic and translational research, have been developed and tested in experimental animals; pigs have played an important role in various aspects of this work. The value of pigs as a model species is being enhanced by the generation of specially designed animals through cloning and genetic modifications, enabling more sophisticated research to be performed and thus accelerating the clinical application of regenerative medicine. This article reviews the significant aspects of the creation and application of cloned and genetically modified pigs in regenerative medicine research and considers the possible future directions of the technology. We also discuss the importance of reproductive biology as an interface between basic science and clinical medicine. © 2012 Blackwell Verlag GmbH.

  16. Use of regenerative energy sources and hydrogen technology 2006. Proceedings

    International Nuclear Information System (INIS)

    Lehmann, J.; Luschtinetz, T.

    2006-01-01

    This volume contains 25 contributions, which were held on the 13th symposium ''Use of regenerative energy sources and hydrogen technology'' in Stralsund (Germany). Separate documentation items analysing 16 of the contributions have been prepared for the ENERGY database

  17. Error-rate performance analysis of opportunistic regenerative relaying

    KAUST Repository

    Tourki, Kamel; Yang, Hongchuan; Alouini, Mohamed-Slim

    2011-01-01

    In this paper, we investigate an opportunistic relaying scheme where the selected relay assists the source-destination (direct) communication. In our study, we consider a regenerative opportunistic relaying scheme in which the direct path can

  18. New results on performance analysis of opportunistic regenerative relaying

    KAUST Repository

    Tourki, Kamel; Yang, Hongchuan; Alouini, Mohamed-Slim; Qaraqe, Khalid A.

    2013-01-01

    In this paper, we investigate an opportunistic relaying scheme where the selected relay assists the source-destination (direct) communication. In our study, we consider a regenerative opportunistic relaying scheme in which the direct path may

  19. Advanced Space Power Systems (ASPS): Regenerative Fuel Cells (RFC)

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of the regenerative fuel cell project element is to develop power and energy storage technologies that enable new capabilities for future human space...

  20. Quo Vadis medycyno regeneracyjna?: Quo Vadis Regenerative Medicine?

    Science.gov (United States)

    Ratajczak, Mariusz Z; Suszyńska, Malwina

    2013-07-01

    There are presented the most important sources of pluripotent stem cells for potential application in the regenerative medicine. This review summarizes also advantages and disadvantages for potential application of these cells in clinical medicine.

  1. 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.

  2. 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

  3. From regenerative dentistry to regenerative medicine: progress, challenges, and potential applications of oral stem cells

    Directory of Open Access Journals (Sweden)

    Xiao L

    2014-12-01

    Full Text Available Li Xiao,1 Masanori Nasu2 1Department of Pharmacology, 2Research Center, The Nippon Dental University, Tokyo, Japan Abstract: Adult mesenchymal stem cells (MSCs and epithelial stem cells play essential roles in tissue repair and self-healing. Oral MSCs and epithelial stem cells can be isolated from adult human oral tissues, for example, teeth, periodontal ligament, and gingiva. Cocultivated adult oral epithelial stem cells and MSCs could represent some developmental events, such as epithelial invagination and tubular structure formation, signifying their potentials for tissue regeneration. Oral epithelial stem cells have been used in regenerative medicine over 1 decade. They are able to form a stratified cell sheet under three-dimensional culture conditions. Both experimental and clinical data indicate that the cell sheets can not only safely and effectively reconstruct the damaged cornea in humans, but also repair esophageal ulcer in animal models. Oral MSCs include dental pulp stem cells (DPSCs, stem cells from exfoliated deciduous teeth (SHED, stem cells from apical papilla (SCAP, periodontal ligament stem cells (PDLSCs, and mesenchymal stem cells from gingiva (GMSCs. They are widely applied in both regenerative dentistry and medicine. DPSCs, SHED, and SCAP are able to form dentin–pulp complex when being transplanted into immunodeficient animals. They have been experimentally used for the regeneration of dental pulp, neuron, bone muscle and blood vessels in animal models and have shown promising results. PDLSCs and GMSCs are demonstrated to be ideal cell sources for repairing the damaged tissues of periodontal, muscle, and tendon. Despite the abovementioned applications of oral stem cells, only a few human clinical trials are now underway to use them for the treatment of certain diseases. Since clinical use is the end goal, their true regenerative power and safety need to be further examined.Keywords: oral mesenchymal stem cells, oral

  4. Bifunctional electrodes for unitised regenerative fuel cells

    International Nuclear Information System (INIS)

    Altmann, Sebastian; Kaz, Till; Friedrich, Kaspar Andreas

    2011-01-01

    Research highlights: → Different oxygen electrode configurations for the operation in a unitised reversible fuel cell were tested. → Polarisation curves and EIS measurements were recorded. → The mixture of catalysts performs best for the present stage of electrode development. → Potential improvements for the different compositions are discussed. - Abstract: The effects of different configurations and compositions of platinum and iridium oxide electrodes for the oxygen reaction of unitised regenerative fuel cells (URFC) are reported. Bifunctional oxygen electrodes are important for URFC development because favourable properties for the fuel cell and the electrolysis modes must be combined into a single electrode. The bifunctional electrodes were studied under different combinations of catalyst mixtures, multilayer arrangements and segmented configurations with single catalyst areas. Distinct electrochemical behaviour was observed for both modes and can be explained on the basis of impedance spectroscopy. The mixture of both catalysts performs best for the present stage of electrode development. Also, the multilayer electrodes yielded good results with the potential for optimisation. The influence of ionic and electronic resistances on the relative performance is demonstrated. However, penalties due to cross currents in the heterogeneous electrodes were identified and explained by comparing the performance curves with electrodes composed of a single catalyst. Potential improvements for the different compositions are discussed.

  5. Dental pulp stem cells in regenerative dentistry.

    Science.gov (United States)

    Casagrande, Luciano; Cordeiro, Mabel M; Nör, Silvia A; Nör, Jacques E

    2011-01-01

    Stem cells constitute the source of differentiated cells for the generation of tissues during development, and for regeneration of tissues that are diseased or injured postnatally. In recent years, stem cell research has grown exponentially owing to the recognition that stem cell-based therapies have the potential to improve the life of patients with conditions that span from Alzheimer's disease to cardiac ischemia to bone or tooth loss. Growing evidence demonstrates that stem cells are primarily found in niches and that certain tissues contain more stem cells than others. Among these tissues, the dental pulp is considered a rich source of mesenchymal stem cells that are suitable for tissue engineering applications. It is known that dental pulp stem cells have the potential to differentiate into several cell types, including odontoblasts, neural progenitors, osteoblasts, chondrocytes, and adipocytes. The dental pulp stem cells are highly proliferative. This characteristic facilitates ex vivo expansion and enhances the translational potential of these cells. Notably, the dental pulp is arguably the most accessible source of postnatal stem cells. Collectively, the multipotency, high proliferation rates, and accessibility make the dental pulp an attractive source of mesenchymal stem cells for tissue regeneration. This review discusses fundamental concepts of stem cell biology and tissue engineering within the context of regenerative dentistry.

  6. Recent advancements in regenerative dentistry: A review.

    Science.gov (United States)

    Amrollahi, Pouya; Shah, Brinda; Seifi, Amir; Tayebi, Lobat

    2016-12-01

    Although human mouth benefits from remarkable mechanical properties, it is very susceptible to traumatic damages, exposure to microbial attacks, and congenital maladies. Since the human dentition plays a crucial role in mastication, phonation and esthetics, finding promising and more efficient strategies to reestablish its functionality in the event of disruption has been important. Dating back to antiquity, conventional dentistry has been offering evacuation, restoration, and replacement of the diseased dental tissue. However, due to the limited ability and short lifespan of traditional restorative solutions, scientists have taken advantage of current advancements in medicine to create better solutions for the oral health field and have coined it "regenerative dentistry." This new field takes advantage of the recent innovations in stem cell research, cellular and molecular biology, tissue engineering, and materials science etc. In this review, the recently known resources and approaches used for regeneration of dental and oral tissues were evaluated using the databases of Scopus and Web of Science. Scientists have used a wide range of biomaterials and scaffolds (artificial and natural), genes (with viral and non-viral vectors), stem cells (isolated from deciduous teeth, dental pulp, periodontal ligament, adipose tissue, salivary glands, and dental follicle) and growth factors (used for stimulating cell differentiation) in order to apply tissue engineering approaches to dentistry. Although they have been successful in preclinical and clinical partial regeneration of dental tissues, whole-tooth engineering still seems to be far-fetched, unless certain shortcomings are addressed. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Mesenchymal dental stem cells in regenerative dentistry.

    Science.gov (United States)

    Rodríguez-Lozano, Francisco-Javier; Insausti, Carmen-Luisa; Iniesta, Francisca; Blanquer, Miguel; Ramírez, María-del-Carmen; Meseguer, Luis; Meseguer-Henarejos, Ana-Belén; Marín, Noemí; Martínez, Salvador; Moraleda, José-María

    2012-11-01

    In the last decade, tissue engineering is a field that has been suffering an enormous expansion in the regenerative medicine and dentistry. The use of cells as mesenchymal dental stem cells of easy access for dentist and oral surgeon, immunosuppressive properties, high proliferation and capacity to differentiate into odontoblasts, cementoblasts, osteoblasts and other cells implicated in the teeth, suppose a good perspective of future in the clinical dentistry. However, is necessary advance in the known of growth factors and signalling molecules implicated in tooth development and regeneration of different structures of teeth. Furthermore, these cells need a fabulous scaffold that facility their integration, differentiation, matrix synthesis and promote multiple specific interactions between cells. In this review, we give a brief description of tooth development and anatomy, definition and classification of stem cells, with special attention of mesenchymal stem cells, commonly used in the cellular therapy for their trasdifferentiation ability, non ethical problems and acceptable results in preliminary clinical trials. In terms of tissue engineering, we provide an overview of different types of mesenchymal stem cells that have been isolated from teeth, including dental pulp stem cells (DPSCs), stem cells from human exfoliated deciduous teeth (SHEDs), periodontal ligament stem cells (PDLSCs), dental follicle progenitor stem cells (DFPCs), and stem cells from apical papilla (SCAPs), growth factors implicated in regeneration teeth and types of scaffolds for dental tissue regeneration.

  8. Alkaline Materials and Regenerative Endodontics: A Review

    Directory of Open Access Journals (Sweden)

    Bill Kahler

    2017-12-01

    Full Text Available Periapical health is the primary goal of endodontic treatment in mature and immature teeth. In addition, the goals of treatment of immature teeth with arrested root development include root growth to length and maturation of the apex, as well as thickening of the canal wall. These goals are valid for immature teeth that have been subjected to trauma and dental caries or that are the result of developmental anomalies that expose the tooth to the risk of pulp necrosis and consequently result in the cessation of root maturation. Regenerative endodontic procedures (REPs have been described as a “paradigm shift” in the treatment of immature teeth with pulp necrosis and underdeveloped roots, as there is the potential for further root maturation and return of vitality. Treatment with REPs is advocated as the treatment of choice for immature teeth with pulp necrosis. REP protocols involve the use of alkaline biomaterials, primarily sodium hypochlorite, calcium hydroxide, mineral trioxide aggregates and Biodentine, and are the essential components of a successful treatment regimen.

  9. Hierarchical Design of Tissue Regenerative Constructs.

    Science.gov (United States)

    Rose, Jonas C; De Laporte, Laura

    2018-03-01

    The worldwide shortage of organs fosters significant advancements in regenerative therapies. Tissue engineering and regeneration aim to supply or repair organs or tissues by combining material scaffolds, biochemical signals, and cells. The greatest challenge entails the creation of a suitable implantable or injectable 3D macroenvironment and microenvironment to allow for ex vivo or in vivo cell-induced tissue formation. This review gives an overview of the essential components of tissue regenerating scaffolds, ranging from the molecular to the macroscopic scale in a hierarchical manner. Further, this review elaborates about recent pivotal technologies, such as photopatterning, electrospinning, 3D bioprinting, or the assembly of micrometer-scale building blocks, which enable the incorporation of local heterogeneities, similar to most native extracellular matrices. These methods are applied to mimic a vast number of different tissues, including cartilage, bone, nerves, muscle, heart, and blood vessels. Despite the tremendous progress that has been made in the last decade, it remains a hurdle to build biomaterial constructs in vitro or in vivo with a native-like structure and architecture, including spatiotemporal control of biofunctional domains and mechanical properties. New chemistries and assembly methods in water will be crucial to develop therapies that are clinically translatable and can evolve into organized and functional tissues. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Regenerative periapical surgery: A case report

    Directory of Open Access Journals (Sweden)

    Sonam Bhandari

    2013-01-01

    Full Text Available Introduction: Periapical surgery is an important treatment alternative in the presence of a large periapical cyst. To achieve optimal healing and regeneration of the bone different bone substitutes can be used. Case Report: A 35 year old male patient reported with the soft diffuse swelling in anterior palatal region and drainings in us with 21 labially. He had a history of trauma 5 years back. The clinical and radiographic diagnosis of infected periapical cyst with 11,21; invasive cervical root resorption with 21 and internal root resorption with 11 was made. Endodontic treatment was performed with11,2 followed by periapical curettage. A picectomy and retrograde filling with white mineral trioxide aggregate (MTA was carried out with 11,21. The cervical resorption defect with 21 was restored with white MTA. Platelet rich fibrin (PRF was mixed with demineralised bone matrix (Osseograft and used as a regenerative biomaterial in the periapiacl defect. 14 months follow up shows satisfactory healing and regeneration of periapical region. Discussion: There is considerable clinical interest in using PRF alone or in combination with graft materials as it is a reservoir of many growth factors and have potential for accelerated soft-and hard tissue healing. PRF is a new generation of platelet concentrate, derived from patients own blood.

  11. MicroRNA delivery for regenerative medicine.

    Science.gov (United States)

    Peng, Bo; Chen, Yongming; Leong, Kam W

    2015-07-01

    MicroRNA (miRNA) directs post-transcriptional regulation of a network of genes by targeting mRNA. Although relatively recent in development, many miRNAs direct differentiation of various stem cells including induced pluripotent stem cells (iPSCs), a major player in regenerative medicine. An effective and safe delivery of miRNA holds the key to translating miRNA technologies. Both viral and nonviral delivery systems have seen success in miRNA delivery, and each approach possesses advantages and disadvantages. A number of studies have demonstrated success in augmenting osteogenesis, improving cardiogenesis, and reducing fibrosis among many other tissue engineering applications. A scaffold-based approach with the possibility of local and sustained delivery of miRNA is particularly attractive since the physical cues provided by the scaffold may synergize with the biochemical cues induced by miRNA therapy. Herein, we first briefly cover the application of miRNA to direct stem cell fate via replacement and inhibition therapies, followed by the discussion of the promising viral and nonviral delivery systems. Next we present the unique advantages of a scaffold-based delivery in achieving lineage-specific differentiation and tissue development. Copyright © 2015 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

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

    2012-08-01

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

  13. A high-power compact regenerative amplifier FEL

    International Nuclear Information System (INIS)

    Nguyen, D.C.; Sheffield, R.L.; Fortgang, C.M.; Kinross-Wright, J.M.; Ebrahim, N.A.; Goldstein, J.C.

    1997-01-01

    The Regenerative Amplifier FEL (RAFEL) is a new FEL approach aimed at achieving the highest optical power from a compact rf-linac FEL. The key idea is to feed back a small fraction ( 5 in single pass) wiggler to enable the FEL to reach saturation in a few passes. This paper summarizes the design of a high-power compact regenerative amplifier FEL and describes the first experimental demonstration of the RAFEL concept

  14. Design of An Energy Efficient Hydraulic Regenerative circuit

    Science.gov (United States)

    Ramesh, S.; Ashok, S. Denis; Nagaraj, Shanmukha; Adithyakumar, C. R.; Reddy, M. Lohith Kumar; Naulakha, Niranjan Kumar

    2018-02-01

    Increasing cost and power demand, leads to evaluation of new method to increase through productivity and help to solve the power demands. Many researchers have break through to increase the efficiency of a hydraulic power pack, one of the promising methods is the concept of regenerative. The objective of this research work is to increase the efficiency of a hydraulic circuit by introducing a concept of regenerative circuit. A Regenerative circuit is a system that is used to speed up the extension stroke of the double acting single rod hydraulic cylinder. The output is connected to the input in the directional control value. By this concept, increase in velocity of the piston and decrease the cycle time. For the research, a basic hydraulic circuit and a regenerative circuit are designated and compared both with their results. The analysis was based on their time taken for extension and retraction of the piston. From the detailed analysis of both the hydraulic circuits, it is found that the efficiency by introducing hydraulic regenerative circuit increased by is 5.3%. The obtained results conclude that, implementing hydraulic regenerative circuit in a hydraulic power pack decreases power consumption, reduces cycle time and increases productivity in a longer run.

  15. The regenerative medicine coalition. Interview with Frank-Roman Lauter.

    Science.gov (United States)

    Lauter, Frank-Roman

    2012-11-01

    Frank-Roman Lauter, Secretary General of the recently launched Regenerative Medicine Coalition, explains how the coalition was formed and what they hope to achieve. Frank-Roman Lauter has served as Secretary General of the Regenerative Medicine Coalition since 2012, and as Head of Business Development at Berlin-Brandenburg Center for Regenerative Therapies since 2007. Frank-Roman Lauter's interest is the organization of academic infrastructures to promote efficient translation of research findings into new therapies. He co-organizes joined strategy development for regenerative medicine clusters from seven European countries (FP7-EU Project) and has initiated cooperation between the California Institute for Regenerative Medicine and the German Federal Ministry for Education & Research, resulting in a joined funding program. Recently, he cofounded the international consortium of Regenerative Medicine translational centers (RMC; www.the-rmc.org ). Trained as a molecular biologist at the Max-Planck Institute in Berlin-Dahlem and at Stanford, he has 16 years of experience as an entrepreneur and life science manager in Germany and the USA.

  16. Stripping of organic compounds from wastewater as an auxiliary fuel of regenerative thermal oxidizer

    International Nuclear Information System (INIS)

    Chang, Meng-Wen; Chern, Jia-Ming

    2009-01-01

    Organic solvents with different volatilities are widely used in various processes and generate air and water pollution problems. In the cleaning processes of electronics industries, most volatile organic compounds (VOCs) are vented to air pollution control devices while most non-volatile organic solvents dissolve in the cleaning water and become the major sources of COD in wastewater. Discharging a high-COD wastewater stream to wastewater treatment facility often disturbs the treatment performance. A pretreatment of the high-COD wastewater is therefore highly desirable. This study used a packed-bed stripping tower in combination with a regenerative thermal oxidizer to remove the COD in the wastewater from a printed circuit board manufacturing process and to utilize the stripped organic compounds as the auxiliary fuel of the RTO. The experimental results showed that up to 45% of the COD could be removed and 66% of the RTO fuel could be saved by the combined treatment system.

  17. 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..

  18. 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)

  19. 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.

  20. 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

  1. Heavy metal extraction from PCB wastewater treatment sludge by sulfuric acid

    International Nuclear Information System (INIS)

    Kuan, Yu-Chung; Lee, I-Hsien; Chern, Jia-Ming

    2010-01-01

    Heavy metals contaminated wastewater sludge is classified as hazardous solid waste and needs to be properly treated to prevent releasing heavy metals to the environment. In this study, the wastewater treatment sludge from a printed circuit board manufacturing plant was treated in a batch reactor by sulfuric acid to remove the contained heavy metals. The effects of sulfuric acid concentration and solid to liquid ratio on the heavy metal removal efficiencies were investigated. The experimental results showed that the total and individual heavy metal removal efficiencies increased with increasing sulfuric acid concentration, but decreased with increasing solid to liquid ratio. A mathematical model was developed to predict the residual sludge weights at varying sulfuric concentrations and solid to liquid ratios. The trivalent heavy metal ions, iron and chromium were more difficult to be removed than the divalent ions, copper, zinc, nickel, and cadmium. For 5 g/L solid to liquid ratio, more than 99.9% of heavy metals can be removed from the sludge by treating with 0.5 M sulfuric acid in 2 h.

  2. Experience on sodium removal from various components

    Energy Technology Data Exchange (ETDEWEB)

    Kamei, M; Kanbe, M; Yagisawa, H; Sasaki, S; Kataoka, H; Fukada, T; Ishii, Y; Saito, R; Mimoto, Y [O-arai Engineering Centre, PNC, Ibaraki-ken, Tokio (Japan)

    1978-08-01

    Since 1970, OEC (O-arai Engineering Center) has been Investigating the following methods for removal of sodium from the components of sodium plants: steam cleaning for the 50 MW Steam Generator, secondary proto-type pump of 'JOYO' and Dummy fuel assembly of 'JOYO', alcohol cleaning for Sector Model of Intermediate Heat Exchanger (IHX) of 'JOYO', a sector model of Sodium-to-Air cooler of 'JOYO' and a proto-type isolation valve of 'JOYO' and cleaning by vacuumization at high temperature for Regenerative Heat Exchanger. This report describes the outline of the Sodium Disposal Facility and experience of sodium removal processing on the 50 MW Steam Generator, the crevices of the experimental sub-assemblies, the Fuel Handling Machine of 'MONJU' and the Regenerative Heat Exchanger of the Sodium Flow Test Facility. Through these experiences it was noted that, (1) Removal of sodium from crevices such as in bolted joints are very difficult. (2) Consideration is needed in the removal process where material damage might occur from the generation of hydro-oxides. (3) Some detection device to tell the completion of sodium removal as well as the end of reaction is required. (4) Requalification rules should be clarified. Efforts in this direction have been made in the case of a 'JOYO' prototype pump by reinstalling it after sodium removal five times. (author)

  3. Experience on sodium removal from various components

    International Nuclear Information System (INIS)

    Kamei, M.; Kanbe, M.; Yagisawa, H.; Sasaki, S.; Kataoka, H.; Fukada, T.; Ishii, Y.; Saito, R.; Mimoto, Y.

    1978-01-01

    Since 1970, OEC (O-arai Engineering Center) has been Investigating the following methods for removal of sodium from the components of sodium plants: steam cleaning for the 50 MW Steam Generator, secondary proto-type pump of 'JOYO' and Dummy fuel assembly of 'JOYO', alcohol cleaning for Sector Model of Intermediate Heat Exchanger (IHX) of 'JOYO', a sector model of Sodium-to-Air cooler of 'JOYO' and a proto-type isolation valve of 'JOYO' and cleaning by vacuumization at high temperature for Regenerative Heat Exchanger. This report describes the outline of the Sodium Disposal Facility and experience of sodium removal processing on the 50 MW Steam Generator, the crevices of the experimental sub-assemblies, the Fuel Handling Machine of 'MONJU' and the Regenerative Heat Exchanger of the Sodium Flow Test Facility. Through these experiences it was noted that, (1) Removal of sodium from crevices such as in bolted joints are very difficult. (2) Consideration is needed in the removal process where material damage might occur from the generation of hydro-oxides. (3) Some detection device to tell the completion of sodium removal as well as the end of reaction is required. (4) Requalification rules should be clarified. Efforts in this direction have been made in the case of a 'JOYO' prototype pump by reinstalling it after sodium removal five times. (author)

  4. Experience on sodium removal from various components

    International Nuclear Information System (INIS)

    Kamei, M.; Kanbe, M.; Yagisawa, H.; Sasaki, S.; Kataoka, H.

    1978-02-01

    Since 1970, OEC (O-arai Engineering Center) has been investigating the following methods for removal of sodium from the components of sodium plants: steam cleaning for the 50 MW Steam Generator, secondary proto-type pump of ''JOYO'' and Dummy fuel assembly of ''JOYO'', alcohol cleaning for Sector Model of Intermediate Heat Exchanger (IHX) of ''JOYO'', a sector model of Sodium-to-Air cooler of ''JOYO'' and a proto-type Isolation valve of ''JOYO'' and cleaning by vacuumization at high temperature for Regenerative Heat Exchanger. This report describes the outline of the Sodium Disposal Facility and experience of sodium removal processing on the 50 MW Steam Generator, the crevices of the experimental subassemblies, the Fuel Handling Machine of ''MONJU'' and the Regenerative Heat Exchanger of the Sodium Flow Test Facility. Through these experiences it was noted that, (1) Removal of Sodium from crevices such as in bolted joints are very difficult. (2) Consideration is needed in the removal process where material damage might occur from the generation of hydro-oxides. (3) Some detection device to tell the completion of sodium removal as well as the end of reaction is required. (4) Requalification rules should be clarified. Efforts in this direction have been made in the case of a ''JOYO'' prototype pump by reinstalling it after sodium removal five times. (author)

  5. Regeneration and Repair in Endodontics—A Special Issue of the Regenerative Endodontics—A New Era in Clinical Endodontics

    Directory of Open Access Journals (Sweden)

    Tarek Mohamed A. Saoud

    2016-02-01

    Full Text Available Caries is the most common cause of pulp-periapical disease. When the pulp tissue involved in caries becomes irreversibly inflamed and progresses to necrosis, the treatment option is root canal therapy because the infected or non-infected necrotic pulp tissue in the root canal system is not accessible to the host's innate and adaptive immune defense mechanisms and antimicrobial agents. Therefore, the infected or non-infected necrotic pulp tissue must be removed from the canal space by pulpectomy. As our knowledge in pulp biology advances, the concept of treatment of pulpal and periapical disease also changes. Endodontists have been looking for biologically based treatment procedures, which could promote regeneration or repair of the dentin-pulp complex destroyed by infection or trauma for several decades. After a long, extensive search in in vitro laboratory and in vivo preclinical animal experiments, the dental stem cells capable of regenerating the dentin-pulp complex were discovered. Consequently, the biological concept of ‘regenerative endodontics’ emerged and has highlighted the paradigm shift in the treatment of immature permanent teeth with necrotic pulps in clinical endodontics. Regenerative endodontics is defined as biologically based procedures designed to physiologically replace damaged tooth structures, including dentin and root structures, as well as the pulp-dentin complex. According to the American Association of Endodontists’ Clinical Considerations for a Regenerative Procedure, the primary goal of the regenerative procedure is the elimination of clinical symptoms and the resolution of apical periodontitis. Thickening of canal walls and continued root maturation is the secondary goal. Therefore, the primary goal of regenerative endodontics and traditional non-surgical root canal therapy is the same. The difference between non-surgical root canal therapy and regenerative endodontic therapy is that the disinfected root canals

  6. Regeneration and Repair in Endodontics—A Special Issue of the Regenerative Endodontics—A New Era in Clinical Endodontics

    Science.gov (United States)

    Saoud, Tarek Mohamed A.; Ricucci, Domenico; Lin, Louis M.; Gaengler, Peter

    2016-01-01

    Caries is the most common cause of pulp-periapical disease. When the pulp tissue involved in caries becomes irreversibly inflamed and progresses to necrosis, the treatment option is root canal therapy because the infected or non-infected necrotic pulp tissue in the root canal system is not accessible to the host's innate and adaptive immune defense mechanisms and antimicrobial agents. Therefore, the infected or non-infected necrotic pulp tissue must be removed from the canal space by pulpectomy. As our knowledge in pulp biology advances, the concept of treatment of pulpal and periapical disease also changes. Endodontists have been looking for biologically based treatment procedures, which could promote regeneration or repair of the dentin-pulp complex destroyed by infection or trauma for several decades. After a long, extensive search in in vitro laboratory and in vivo preclinical animal experiments, the dental stem cells capable of regenerating the dentin-pulp complex were discovered. Consequently, the biological concept of ‘regenerative endodontics’ emerged and has highlighted the paradigm shift in the treatment of immature permanent teeth with necrotic pulps in clinical endodontics. Regenerative endodontics is defined as biologically based procedures designed to physiologically replace damaged tooth structures, including dentin and root structures, as well as the pulp-dentin complex. According to the American Association of Endodontists’ Clinical Considerations for a Regenerative Procedure, the primary goal of the regenerative procedure is the elimination of clinical symptoms and the resolution of apical periodontitis. Thickening of canal walls and continued root maturation is the secondary goal. Therefore, the primary goal of regenerative endodontics and traditional non-surgical root canal therapy is the same. The difference between non-surgical root canal therapy and regenerative endodontic therapy is that the disinfected root canals in the former

  7. Regeneration and Repair in Endodontics-A Special Issue of the Regenerative Endodontics-A New Era in Clinical Endodontics.

    Science.gov (United States)

    Saoud, Tarek Mohamed A; Ricucci, Domenico; Lin, Louis M; Gaengler, Peter

    2016-02-27

    Caries is the most common cause of pulp-periapical disease. When the pulp tissue involved in caries becomes irreversibly inflamed and progresses to necrosis, the treatment option is root canal therapy because the infected or non-infected necrotic pulp tissue in the root canal system is not accessible to the host's innate and adaptive immune defense mechanisms and antimicrobial agents. Therefore, the infected or non-infected necrotic pulp tissue must be removed from the canal space by pulpectomy. As our knowledge in pulp biology advances, the concept of treatment of pulpal and periapical disease also changes. Endodontists have been looking for biologically based treatment procedures, which could promote regeneration or repair of the dentin-pulp complex destroyed by infection or trauma for several decades. After a long, extensive search in in vitro laboratory and in vivo preclinical animal experiments, the dental stem cells capable of regenerating the dentin-pulp complex were discovered. Consequently, the biological concept of 'regenerative endodontics' emerged and has highlighted the paradigm shift in the treatment of immature permanent teeth with necrotic pulps in clinical endodontics. Regenerative endodontics is defined as biologically based procedures designed to physiologically replace damaged tooth structures, including dentin and root structures, as well as the pulp-dentin complex. According to the American Association of Endodontists' Clinical Considerations for a Regenerative Procedure, the primary goal of the regenerative procedure is the elimination of clinical symptoms and the resolution of apical periodontitis. Thickening of canal walls and continued root maturation is the secondary goal. Therefore, the primary goal of regenerative endodontics and traditional non-surgical root canal therapy is the same. The difference between non-surgical root canal therapy and regenerative endodontic therapy is that the disinfected root canals in the former therapy are

  8. Conversion of sulfur and nitrogen oxides in air under exposure to microsecond electron beams

    International Nuclear Information System (INIS)

    Denisov, G.V.; Kuznetsov, D.L.; Novoselov, Yu.N.; Tkachenko, R.M.

    2002-01-01

    Flue gases of power plants realizing sulfur and nitrogen oxides into the atmosphere represent one of the environmental pollution sources. Paper presents the results of experimental investigations of conversion of sulfur and nitrogen oxides in the ionized gas mixture simulating composition of off-gases of thermal power stations. Pulse beam of microsecond duration electrons was used as a source of ionization. Mutual influence of both types of oxides on process of their conversion is shown. One studied possible kinetic mechanisms to remove sulfur and nitrogen oxides from gaseous mixture [ru

  9. Sulfur Solubility Testing and Characterization of LAW Phase 1 Matrix Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-02-24

    In this report, the Savannah River National Laboratory (SRNL) provides chemical analysis results for a series of simulated low-activity waste (LAW) glass compositions. These data will be used in the development of improved sulfur solubility models for LAW glass. A procedure developed at Pacific Northwest National Laboratory (PNNL) for producing sulfur saturated melts (SSMs) was carried out at both SRNL and PNNL to fabricate the glasses characterized in this report. This method includes triplicate melting steps with excess sodium sulfate, followed by grinding and washing to remove unincorporated sulfur salts. The wash solutions were also analyzed as part of this study.

  10. Sulfur Solubility Testing and Characterization of Hanford LAW Phase 2, Inner Layer Matrix Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Edwards, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Caldwell, M. E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Riley, W. T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-11-27

    In this report, the Savannah River National Laboratory (SRNL) provides chemical analyses and Product Consistency Test (PCT) results for a series of simulated low activity waste (LAW) glass compositions. A procedure developed at the Pacific Northwest National Laboratory (PNNL) for producing sulfur saturated melts (SSMs) was carried out at both SRNL and PNNL to fabricate the glasses characterized in this report. This method includes triplicate melting steps with excess sodium sulfate, followed by grinding and washing to remove unincorporated sulfur salts. The wash solutions were also analyzed as part of this study. These data will be used in the development of improved sulfur solubility models for LAW glass.

  11. Volatile Sulfur Compounds from Livestock Production

    DEFF Research Database (Denmark)

    Kasper, Pernille

    . Presently, the development of abatement technologies is limited by the lack of an accurate and reliable method for quantifying the effect on odor. To measure the impact of air cleaning techniques on perceived odor, common practice in Europe is to store odor samples in sample bags and quantify them......Volatile sulfur compounds, i.e. hydrogen sulfide, methanethiol and dimethyl sulfide have been identified as key odorants in livestock production due to their high concentration levels and low odor threshold values. At the same time their removal with abatement technologies based on mass transfer...... from a gas phase to a liquid phase, e.g. biotrickling filters, is decelerated due to their low partitioning coefficients. This can significantly limit the odor reduction obtained with these technologies. The present study examines the possibility of adding metal catalysts to enhance the mass transfer...

  12. Regenerative agriculture: merging farming and natural resource conservation profitably.

    Science.gov (United States)

    LaCanne, Claire E; Lundgren, Jonathan G

    2018-01-01

    Most cropland in the United States is characterized by large monocultures, whose productivity is maintained through a strong reliance on costly tillage, external fertilizers, and pesticides (Schipanski et al., 2016). Despite this, farmers have developed a regenerative model of farm production that promotes soil health and biodiversity, while producing nutrient-dense farm products profitably. Little work has focused on the relative costs and benefits of novel regenerative farming operations, which necessitates studying in situ , farmer-defined best management practices. Here, we evaluate the relative effects of regenerative and conventional corn production systems on pest management services, soil conservation, and farmer profitability and productivity throughout the Northern Plains of the United States. Regenerative farming systems provided greater ecosystem services and profitability for farmers than an input-intensive model of corn production. Pests were 10-fold more abundant in insecticide-treated corn fields than on insecticide-free regenerative farms, indicating that farmers who proactively design pest-resilient food systems outperform farmers that react to pests chemically. Regenerative fields had 29% lower grain production but 78% higher profits over traditional corn production systems. Profit was positively correlated with the particulate organic matter of the soil, not yield. These results provide the basis for dialogue on ecologically based farming systems that could be used to simultaneously produce food while conserving our natural resource base: two factors that are pitted against one another in simplified food production systems. To attain this requires a systems-level shift on the farm; simply applying individual regenerative practices within the current production model will not likely produce the documented results.

  13. Stability of patulin to sulfur dioxide and to yeast fermentation.

    Science.gov (United States)

    Burroughs, L F

    1977-01-01

    The affinity of patulin for sulfur dioxide (SO2) is much less than was previously reported and is of little significance at the SO2 concentrations (below 200 ppm) used in the processing of apple juice and cider. However, at concentrations of 2000 ppm SO2 and 15 ppm patulin, combination was 90% complete in 2 days. Removal of SO2 liberated only part of the patulin, which suggests that 2 mechanisms are involved: one reversible (opening the hemiacetal ring) and one irreversible (SO2 addition at the double bond). Test with 2 yeasts used in English commercial cider making confirmed that patulin is effectively removed during yeast fermentation.

  14. 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

  15. Dental Mesenchymal Stem Cell-Based Translational Regenerative Dentistry: From Artificial to Biological Replacement

    Science.gov (United States)

    Marei, Mona K.; El Backly, Rania M.

    2018-01-01

    Dentistry is a continuously changing field that has witnessed much advancement in the past century. Prosthodontics is that branch of dentistry that deals with replacing missing teeth using either fixed or removable appliances in an attempt to simulate natural tooth function. Although such “replacement therapies” appear to be easy and economic they fall short of ever coming close to their natural counterparts. Complications that arise often lead to failures and frequent repairs of such devices which seldom allow true physiological function of dental and oral-maxillofacial tissues. Such factors can critically affect the quality of life of an individual. The market for dental implants is continuously growing with huge economic revenues. Unfortunately, such treatments are again associated with frequent problems such as peri-implantitis resulting in an eventual loss or replacement of implants. This is particularly influential for patients having co-morbid diseases such as diabetes or osteoporosis and in association with smoking and other conditions that undoubtedly affect the final treatment outcome. The advent of tissue engineering and regenerative medicine therapies along with the enormous strides taken in their associated interdisciplinary fields such as stem cell therapy, biomaterial development, and others may open arenas to enhancing tissue regeneration via designing and construction of patient-specific biological and/or biomimetic substitutes. This review will overview current strategies in regenerative dentistry while overviewing key roles of dental mesenchymal stem cells particularly those of the dental pulp, until paving the way to precision/translational regenerative medicine therapies for future clinical use. PMID:29770323

  16. Dental Mesenchymal Stem Cell-Based Translational Regenerative Dentistry: From Artificial to Biological Replacement

    Directory of Open Access Journals (Sweden)

    Mona K. Marei

    2018-05-01

    Full Text Available Dentistry is a continuously changing field that has witnessed much advancement in the past century. Prosthodontics is that branch of dentistry that deals with replacing missing teeth using either fixed or removable appliances in an attempt to simulate natural tooth function. Although such “replacement therapies” appear to be easy and economic they fall short of ever coming close to their natural counterparts. Complications that arise often lead to failures and frequent repairs of such devices which seldom allow true physiological function of dental and oral-maxillofacial tissues. Such factors can critically affect the quality of life of an individual. The market for dental implants is continuously growing with huge economic revenues. Unfortunately, such treatments are again associated with frequent problems such as peri-implantitis resulting in an eventual loss or replacement of implants. This is particularly influential for patients having co-morbid diseases such as diabetes or osteoporosis and in association with smoking and other conditions that undoubtedly affect the final treatment outcome. The advent of tissue engineering and regenerative medicine therapies along with the enormous strides taken in their associated interdisciplinary fields such as stem cell therapy, biomaterial development, and others may open arenas to enhancing tissue regeneration via designing and construction of patient-specific biological and/or biomimetic substitutes. This review will overview current strategies in regenerative dentistry while overviewing key roles of dental mesenchymal stem cells particularly those of the dental pulp, until paving the way to precision/translational regenerative medicine therapies for future clinical use.

  17. The dissolution kinetics of magnetite under regenerative conditions

    International Nuclear Information System (INIS)

    Ranganathan, S.

    2004-01-01

    Dissolution studies of magnetite were carried out under regenerative conditions in dilute chemical decontamination formulations. During regeneration of the formulation, the H + from the strong acid cation exchange resin gets released and the metal is absorbed on the resin. The efficiency of the regenerative process depends on the stability constants of the complexes involved and the selectivity on the ion exchange column. The regenerative condition helps to maintain a constant chelating agent concentration and pH during the dissolution experiment. Such a condition is ideal for obtaining data on the dissolution behaviour of the corrosion products with special application to actual reactor decontamination. The ethylenediaminetetraacetic acid (EDTA) based formulation used was found to be ineffective due to the high stability constant of Fe(III)-EDTA complex, which is not easily cleaved by the cation exchange resin. Hence, knowledge of the kinetics of magnetite dissolution under regenerative condition is of primary importance. The 2,6-pyridinedicarboxylic acid formulation is found to be better for the dissolution of Fe 3 O 4 in both static and regenerative modes in the presence of reductants than nitrilotriacetic acid and EDTA. (orig.)

  18. The dissolution kinetics of magnetite under regenerative conditions

    Energy Technology Data Exchange (ETDEWEB)

    Ranganathan, S. [New Brunswick Univ., Frederiction (Canada). Dept. of Chemical Engineering; Raghavan, P.S.; Gopalan, R.; Srinivasan, M.P.; Narasimhan, S.V. [Water and Steam Chemistry Lab. of Bhabha Atomic Research Centre (BARC) (India)

    2004-07-01

    Dissolution studies of magnetite were carried out under regenerative conditions in dilute chemical decontamination formulations. During regeneration of the formulation, the H{sup +} from the strong acid cation exchange resin gets released and the metal is absorbed on the resin. The efficiency of the regenerative process depends on the stability constants of the complexes involved and the selectivity on the ion exchange column. The regenerative condition helps to maintain a constant chelating agent concentration and pH during the dissolution experiment. Such a condition is ideal for obtaining data on the dissolution behaviour of the corrosion products with special application to actual reactor decontamination. The ethylenediaminetetraacetic acid (EDTA) based formulation used was found to be ineffective due to the high stability constant of Fe(III)-EDTA complex, which is not easily cleaved by the cation exchange resin. Hence, knowledge of the kinetics of magnetite dissolution under regenerative condition is of primary importance. The 2,6-pyridinedicarboxylic acid formulation is found to be better for the dissolution of Fe{sub 3}O{sub 4} in both static and regenerative modes in the presence of reductants than nitrilotriacetic acid and EDTA. (orig.)

  19. Erich Regener and the ionisation maximum of the atmosphere

    Science.gov (United States)

    Carlson, P.; Watson, A. A.

    2014-12-01

    In the 1930s the German physicist Erich Regener (1881-1955) did important work on the measurement of the rate of production of ionisation deep under water and in the atmosphere. Along with one of his students, Georg Pfotzer, he discovered the altitude at which the production of ionisation in the atmosphere reaches a maximum, often, but misleadingly, called the Pfotzer maximum. Regener was one of the first to estimate the energy density of cosmic rays, an estimate that was used by Baade and Zwicky to bolster their postulate that supernovae might be their source. Yet Regener's name is less recognised by present-day cosmic ray physicists than it should be, largely because in 1937 he was forced to take early retirement by the National Socialists as his wife had Jewish ancestors. In this paper we briefly review his work on cosmic rays and recommend an alternative naming of the ionisation maximum. The influence that Regener had on the field through his son, his son-in-law, his grandsons and his students, and through his links with Rutherford's group in Cambridge, is discussed in an appendix. Regener was nominated for the Nobel Prize in Physics by Schrödinger in 1938. He died in 1955 at the age of 73.

  20. Repairing quite swimmingly: advances in regenerative medicine using zebrafish.

    Science.gov (United States)

    Goessling, Wolfram; North, Trista E

    2014-07-01

    Regenerative medicine has the promise to alleviate morbidity and mortality caused by organ dysfunction, longstanding injury and trauma. Although regenerative approaches for a few diseases have been highly successful, some organs either do not regenerate well or have no current treatment approach to harness their intrinsic regenerative potential. In this Review, we describe the modeling of human disease and tissue repair in zebrafish, through the discovery of disease-causing genes using classical forward-genetic screens and by modulating clinically relevant phenotypes through chemical genetic screening approaches. Furthermore, we present an overview of those organ systems that regenerate well in zebrafish in contrast to mammalian tissue, as well as those organs in which the regenerative potential is conserved from fish to mammals, enabling drug discovery in preclinical disease-relevant models. We provide two examples from our own work in which the clinical translation of zebrafish findings is either imminent or has already proven successful. The promising results in multiple organs suggest that further insight into regenerative mechanisms and novel clinically relevant therapeutic approaches will emerge from zebrafish research in the future. © 2014. Published by The Company of Biologists Ltd.

  1. An Intelligent Regenerative Braking Strategy for Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Zhibin Song

    2011-09-01

    Full Text Available Regenerative braking is an effective approach for electric vehicles (EVs to extend their driving range. A fuzzy-logic-based regenerative braking strategy (RBS integrated with series regenerative braking is developed in this paper to advance the level of energy-savings. From the viewpoint of securing car stability in braking operations, the braking force distribution between the front and rear wheels so as to accord with the ideal distribution curve are considered to prevent vehicles from experiencing wheel lock and slip phenomena during braking. Then, a fuzzy RBS using the driver’s braking force command, vehicle speed, battery SOC, battery temperature are designed to determine the distribution between friction braking force and regenerative braking force to improve the energy recuperation efficiency. The experimental results on an “LF620” prototype EV validated the feasibility and effectiveness of regenerative braking and showed that the proposed fuzzy RBS was endowed with good control performance. The maximum driving range of LF620 EV was improved by 25.7% compared with non-RBS conditions.

  2. Evaluation strategy of regenerative braking energy for supercapacitor vehicle.

    Science.gov (United States)

    Zou, Zhongyue; Cao, Junyi; Cao, Binggang; Chen, Wen

    2015-03-01

    In order to improve the efficiency of energy conversion and increase the driving range of electric vehicles, the regenerative energy captured during braking process is stored in the energy storage devices and then will be re-used. Due to the high power density of supercapacitors, they are employed to withstand high current in the short time and essentially capture more regenerative energy. The measuring methods for regenerative energy should be investigated to estimate the energy conversion efficiency and performance of electric vehicles. Based on the analysis of the regenerative braking energy system of a supercapacitor vehicle, an evaluation system for energy recovery in the braking process is established using USB portable data-acquisition devices. Experiments under various braking conditions are carried out. The results verify the higher efficiency of energy regeneration system using supercapacitors and the effectiveness of the proposed measurement method. It is also demonstrated that the maximum regenerative energy conversion efficiency can reach to 88%. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

  3. 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

  4. Electric vehicle regenerative antiskid braking and traction control system

    Science.gov (United States)

    Cikanek, Susan R.

    1995-01-01

    An antiskid braking and traction control system for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes one or more sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensors and determining if regenerative antiskid braking control, requiring hydrualic braking control, or requiring traction control are required. The processor then employs a control strategy based on the determined vehicle state and provides command signals to a motor controller to control the operation of the electric traction motor and to a brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative antiskid braking control, hydraulic braking control, and traction control.

  5. Electric vehicle regenerative antiskid braking and traction control system

    Science.gov (United States)

    Cikanek, S.R.

    1995-09-12

    An antiskid braking and traction control system for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes one or more sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensors and determining if regenerative antiskid braking control, requiring hydraulic braking control, or requiring traction control are required. The processor then employs a control strategy based on the determined vehicle state and provides command signals to a motor controller to control the operation of the electric traction motor and to a brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative antiskid braking control, hydraulic braking control, and traction control. 10 figs.

  6. Nanotechnology and regenerative therapeutics in plastic surgery: The next frontier

    Science.gov (United States)

    Tan, Aaron; Chawla, Reema; Natasha, G; Mahdibeiraghdar, Sara; Jeyaraj, Rebecca; Rajadas, Jayakumar; Hamblin, Michael R.; Seifalian, Alexander M.

    2015-01-01

    Summary The rapid ascent of nanotechnology and regenerative therapeutics as applied to medicine and surgery has seen an exponential rise in the scale of research generated in this field. This is evidenced not only by the sheer volume of papers dedicated to nanotechnology but also in a large number of new journals dedicated to nanotechnology and regenerative therapeutics specifically to medicine and surgery. Aspects of nanotechnology that have already brought benefits to these areas include advanced drug delivery platforms, molecular imaging and materials engineering for surgical implants. Particular areas of interest include nerve regeneration, burns and wound care, artificial skin with nanoelectronic sensors and head and neck surgery. This study presents a review of nanotechnology and regenerative therapeutics, with focus on its applications and implications in plastic surgery. PMID:26422652

  7. Nanotechnology and regenerative therapeutics in plastic surgery: The next frontier.

    Science.gov (United States)

    Tan, Aaron; Chawla, Reema; G, Natasha; Mahdibeiraghdar, Sara; Jeyaraj, Rebecca; Rajadas, Jayakumar; Hamblin, Michael R; Seifalian, Alexander M

    2016-01-01

    The rapid ascent of nanotechnology and regenerative therapeutics as applied to medicine and surgery has seen an exponential rise in the scale of research generated in this field. This is evidenced not only by the sheer volume of papers dedicated to nanotechnology but also in a large number of new journals dedicated to nanotechnology and regenerative therapeutics specifically to medicine and surgery. Aspects of nanotechnology that have already brought benefits to these areas include advanced drug delivery platforms, molecular imaging and materials engineering for surgical implants. Particular areas of interest include nerve regeneration, burns and wound care, artificial skin with nanoelectronic sensors and head and neck surgery. This study presents a review of nanotechnology and regenerative therapeutics, with focus on its applications and implications in plastic surgery. Copyright © 2015 British Association of Plastic, Reconstructive and Aesthetic Surgeons. All rights reserved.

  8. Regenerative strategies for the treatment of knee joint disabilities

    CERN Document Server

    Reis, Rui

    2017-01-01

    This book presents regenerative strategies for the treatment of knee joint disabilities. The book is composed of four main sections totaling 19 chapters which review the current knowledge on the clinical management and preclinical regenerative strategies. It examines the role of different natural-based biomaterials as scaffolds and implants for addressing different tissue lesions in the knee joint. Section one provides an updated and comprehensive discussion on articular cartilage tissue regeneration. Section two focuses on the important contributions for bone and osteochondral tissue engineering. Section three overview the recent advances on meniscus repair/regeneration strategies. Finally, section four further discusses the current strategies for treatment of ligament lesions. Each chapter is prepared by world know expert on their fields, so we do firmly believe that the proposed book will be a reference in the area of biomaterials for regenerative medicine.

  9. Accelerating regenerative medicine: the Japanese experiment in ethics and regulation.

    Science.gov (United States)

    Lysaght, Tamra

    2017-09-01

    In 2014, the Japanese National Diet introduced new laws aimed at promoting the clinical translation of stem cells and regenerative medicine. The basic action of these laws is to allow the early introduction of regenerative medicine products into the Japanese market through an accelerated approval process, while providing patients with access to certain types of stem cell and cell-based therapies in the context of private clinical practice. While this framework appears to offer enormous opportunities for the translation of stem cell science, it raises ethical challenges that have not yet been fully explored. This paper critically analyzes this framework with respect to the prioritization of safety over clinical benefit, distributive justice and public trust in science and medicine. It is argued that the framework unfairly burdens patients and strained healthcare systems without any clear benefits, and may undermine the credibility of the regenerative medicine field as it emerges.

  10. Platelet concentrates: Bioengineering dentistry′s regenerative dreams

    Directory of Open Access Journals (Sweden)

    Sushma Naag

    2015-01-01

    Full Text Available Technological advances in the fields of medicine and allied sciences had given much needed momentum into the field of molecular biology and regenerative medicine. They indeed provided a boost to innovate new yields for both hard tissue and soft tissue regeneration in dentistry. One among them is the use of platelet concentrates (platelet rich plasma [PRP], platelet rich fibrin [PRF]. Autologous concentrate of blood platelets with a suspension of growth factors offers an enhanced healing of hard and soft tissues. It is an auxiliary benefit for an operator to be aware of platelet concentrates and its healing properties for delivering unsurpassed oral health care to patients. The current article outlines the principles, objectives and clinical insight to the regenerative potential of platelet concentrates in various fields of dentistry. The search words of the PubMed data base were PRF and other permutations of keywords such as "PRP dentistry", PRF dentistry, PRF regenerative dentistry.

  11. The Ovonic regenerative fuel cell, a fundamentally new approach

    International Nuclear Information System (INIS)

    Ovshinsky, S.R.; Venkatesan, S.; Corrigan, D.A.

    2004-01-01

    The Ovonic Regenerative Fuel Cell utilizes Ovonic metal hydride materials in place of traditional noble metal catalysts in the hydrogen fuel electrode. This provides unique features including the ability to capture and utilize regenerative braking energy at high efficiency and the ability to operate for a significant period upon interruption of the hydrogen fuel supply. Additionally, this novel fuel cell does not use high price components, such as platinum catalysts, microporous membranes, and graphite bipolar plates, used in PEM fuel cells. Proof of concept has been demonstrated in full-size multicell prototypes delivering about 100 W power. The Ovonic Regenerative Fuel Cell is yet another component of ECD Ovonic technology contributing to the emerging hydrogen economy which already includes Uni-Solar PV solar cells, Ovonic solid-state hydrogen storage devices, and Ovonic nickel-metal hydride batteries from Cobasys, a joint venture between ECD Ovonics and ChevronTexaco. (author)

  12. Regenerative medicine: looking backward 10 years further on.

    Science.gov (United States)

    Kemp, Paul

    2016-12-01

    The last decade has seen considerable changes in the Regenerative Medicine industry, but unfortunately the hope for numerous treatments that 'replace or regenerate human cells, tissues or organs to restore or establish normal function' has not yet emerged. In contrast to this, there have been major advances in the field of cellular immunotherapy though some do not consider these to be Regenerative Medicines. Regulatory changes have in some cases improved the route to a marketing license but they have not been matched by clarification of the complex, national reimbursement processes for cell-based treatments and this has adversely affected a number of leading Regenerative Medicine Companies. The review considers the direction that the industry may go in the future in relation to scientific, manufacturing and clinical strategies which may improve the rate of success of new therapies..

  13. Periodontal Regenerative Therapy in Patient with Chronic Periodontitis and Type 2 Diabetes Mellitus: A Case Report.

    Science.gov (United States)

    Seshima, Fumi; Nishina, Makiko; Namba, Takashi; Saito, Atsushi

    2016-01-01

    We report a case of generalized chronic periodontitis and type 2 diabetes mellitus requiring periodontal treatment including regenerative therapy. The patient was a 66-year-old man who presented with the chief complaint of gingival inflammation and mobile teeth in the molar region. He had been being treated for type 2 diabetes mellitus since 1999. His glycated hemoglobin (HbA1c) level was 7.8%. An initial examination revealed sites with a probing depth of ≥7 mm in the molar region, and radiography revealed angular bone defects in this area. Based on a clinical diagnosis of generalized chronic periodontitis, the patient underwent initial periodontal therapy. An improvement was observed in periodontal conditions on reevaluation, and his HbA1c level showed a reduction to 6.9%. Periodontal regenerative therapy with enamel matrix derivative was then performed on #16, 26, and 27. Following another reevaluation, a removable partial denture was fabricated for #47 and the patient placed on supportive periodontal therapy (SPT). To date, periodontal conditions have remained stable and the patient's HbA1c level has increased to 7.5% during SPT. The results show the importance of collaboration between dentist and physician in managing periodontal and diabetic conditions in such patients.

  14. SYNTHESIS OF SULFUR-BASED WATER TREATMENT AGENT FROM SULFUR DIOXIDE WASTE STREAMS

    Energy Technology Data Exchange (ETDEWEB)

    Robert C. Brown; Maohong Fan; Adrienne Cooper

    2002-10-01

    Absorption of sulfur dioxide from a simulated flue gas was investigated for the production of polymeric ferric sulfate (PFS), a highly effective coagulant useful in treatment of drinking water and wastewater. The reaction for PFS synthesis took place near atmospheric pressure and at temperatures of 30-80 C. SO{sub 2} removal efficiencies greater than 90% were achieved, with ferrous iron concentrations in the product less than 0.1%. A factorial analysis of the effect of temperature, oxidant dosage, SO{sub 2} concentration, and gas flow rate on SO{sub 2} removal efficiency was carried out, and statistical analyses are conducted. The solid PFS was also characterized with different methods. Characterization results have shown that PFS possesses both crystalline and non-crystalline structure. The kinetics of reactions among FeSO{sub 4} {center_dot} 7H{sub 2}O, NaHSO{sub 3} and NaClO{sub 3} was investigated. The PFS product was used in pilot-scale tests at a municipal water treatment facility and gave good results in removal of turbidity and superior results in removal of disinfection byproduct precursors (TOC, DOC, UV-254) when compared with equal doses of ferric chloride.

  15. Regenerative memory in time-delayed neuromorphic photonic resonators

    Science.gov (United States)

    Romeira, B.; Avó, R.; Figueiredo, José M. L.; Barland, S.; Javaloyes, J.

    2016-01-01

    We investigate a photonic regenerative memory based upon a neuromorphic oscillator with a delayed self-feedback (autaptic) connection. We disclose the existence of a unique temporal response characteristic of localized structures enabling an ideal support for bits in an optical buffer memory for storage and reshaping of data information. We link our experimental implementation, based upon a nanoscale nonlinear resonant tunneling diode driving a laser, to the paradigm of neuronal activity, the FitzHugh-Nagumo model with delayed feedback. This proof-of-concept photonic regenerative memory might constitute a building block for a new class of neuron-inspired photonic memories that can handle high bit-rate optical signals.

  16. Regenerative endodontics and tissue engineering: what the future holds?

    Science.gov (United States)

    Goodis, Harold E; Kinaia, Bassam Michael; Kinaia, Atheel M; Chogle, Sami M A

    2012-07-01

    The work performed by researchers in regenerative endodontics and tissue engineering over the last decades has been superb; however, many questions remain to be answered. The basic biologic mechanisms must be elucidated that will allow the development of dental pulp and dentin in situ. Stress must be placed on the many questions that will lead to the design of effective, safe treatment options and therapies. This article discusses those questions, the answers to which may become the future of regenerative endodontics. The future remains bright, but proper support and patience are required. Copyright © 2012 Elsevier Inc. All rights reserved.

  17. Performance enhancement of a solar still using cotton regenerative medium

    Directory of Open Access Journals (Sweden)

    Thirumalai Gopal Sakthivel

    2017-01-01

    Full Text Available This paper presents the performance of a single slope solar still using cotton cloth regenerative medium. The performance was evaluated under the metrological conditions of Chennai city in India during the summer months of 2016. Two single-slope solar stills are fabricated with an effective area of 0.5 m2 with various thicknesses (2, 4, 6, and 8 mm of cotton cloth were used for the performance comparison. The results showed, the solar still with 6 mm thick cotton assisted regenerative solar still has about 28% improved productivity when compared to conventional solar still.

  18. Removal of radioactivity and mineral values from uranium mill tailings

    International Nuclear Information System (INIS)

    Williams, J.M.; Cokal, E.J.; Dreesen, D.R.

    1981-01-01

    One possible approach to remedial action on uranium mill tailings involves the removal of the components that are responsible for the environmental concern (notably radon releases) posed by these materials. Removing mineral values at the same time can defray much of the cost. This paper presents laboratory results on sulfuric acid leachings and their effectiveness in accomplishing these aims. 9 figures, 4 tables

  19. 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)

  20. 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.

  1. Study of the reduction of sulfur dioxide to elemental sulfur by carbon monoxide on a La/sub 0/ /sub 5/ Sr/sub 0/ /sub 5/ CoO/sub 3/ catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Hibbert, D B; Tseung, A C.C.

    1979-12-01

    A study of the reduction of sulfur dioxide to elemental sulfur by carbon monoxide on a La/sub 0/ /sub 5/ Sr/sub 0/ /sub 5/ CoO/sub 3/ catalyst a perovskite oxide, to determine the effects of oxygen and water on SO2 reduction showed that in the presence of 5 to 16% oxygen, the reaction between sulfur dioxide and carbon monoxide still occurred if there was sufficient carbon monoxide in the gas to react with all the oxygen. At 600C, all the sulfur dioxide was removed at 5 to 16% oxygen levels. Water vapor at 2% did not adversely affect the reaction. The unwanted by-products, hydrogen disulfide and carbonyl sulfide, were reduced at contact times below 0.25 sec. During the reaction, the catalyst itself reacted with sulfur to give metal sulfides. When reagent grade CO/sub 2/O/sub 3/ was substituted for perovskite oxide, the maximum conversion of 98% of sulfur dioxide was attained at 550C, but an unacceptably high concentration of carbonyl sulfide was formed; within 1 hr, the sulfur dioxide conversion fell to 60%. The perovskite oxide reaction may be useful in removing sulfur dioxide from fosill fuel stack gases.

  2. Growth of the facultative anaerobe Shewanella putrefaciens by elemental sulfur reduction

    Science.gov (United States)

    Moser, D. P.; Nealson, K. H.

    1996-01-01

    The growth of bacteria by dissimilatory elemental sulfur reduction is generally associated with obligate anaerobes and thermophiles in particular. Here we describe the sulfur-dependent growth of the facultatively anaerobic mesophile Shewanella putrefaciens. Six of nine representative S. putrefaciens isolates from a variety of environments proved able to grow by sulfur reduction, and strain MR-1 was chosen for further study. Growth was monitored in a minimal medium (usually with 0.05% Casamino Acids added as a growth stimulant) containing 30 mM lactate and limiting concentrations of elemental sulfur. When mechanisms were provided for the removal of the metabolic end product, H2S, measurable growth was obtained at sulfur concentrations of from 2 to 30 mM. Initial doubling times were ca. 1.5 h and substrate independent over the range of sulfur concentrations tested. In the cultures with the highest sulfur concentrations, cell numbers increased by greater than 400-fold after 48 h, reaching a maximum density of 6.8 x 10(8) cells ml-1. Yields were determined as total cell carbon and ranged from 1.7 to 5.9 g of C mol of S(0) consumed-1 in the presence of the amino acid supplement and from 0.9 to 3.4 g of C mol of S(0-1) in its absence. Several lines of evidence indicate that cell-to-sulfur contact is not required for growth. Approaches for the culture of sulfur-metabolizing bacteria and potential ecological implications of sulfur reduction in Shewanella-like heterotrophs are discussed.

  3. Process for recovery of sulfur from acid gases

    Science.gov (United States)

    Towler, Gavin P.; Lynn, Scott

    1995-01-01

    Elemental sulfur is recovered from the H.sub.2 S present in gases derived from fossil fuels by heating the H.sub.2 S with CO.sub.2 in a high-temperature reactor in the presence of a catalyst selected as one which enhances the thermal dissociation of H.sub.2 S to H.sub.2 and S.sub.2. The equilibrium of the thermal decomposition of H.sub.2 S is shifted by the equilibration of the water-gas-shift reaction so as to favor elemental sulfur formation. The primary products of the overall reaction are S.sub.2, CO, H.sub.2 and H.sub.2 O. Small amounts of COS, SO.sub.2 and CS.sub.2 may also form. Rapid quenching of the reaction mixture results in a substantial increase in the efficiency of the conversion of H.sub.2 S to elemental sulfur. Plant economy is further advanced by treating the product gases to remove byproduct carbonyl sulfide by hydrolysis, which converts the COS back to CO.sub.2 and H.sub.2 S. Unreacted CO.sub.2 and H.sub.2 S are removed from the product gas and recycled to the reactor, leaving a gas consisting chiefly of H.sub.2 and CO, which has value either as a fuel or as a chemical feedstock and recovers the hydrogen value from the H.sub.2 S.

  4. 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;…

  5. 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.

  6. 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...

  7. 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...

  8. 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.

  9. 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

    This research project examined the feasibility of a second generation high-temperature coal gas desulfurization process in which elemental sulfur is produced directly during the sorbent regeneration phase. Two concepts were evaluated experimentally. In the first, FeS was regenerated in a H2O-O2 mixture. Large fractions of the sulfur were liberated in elemental form when the H2O-O2 ratio was large. However, the mole percent of elemental sulfur in the product was always quite small (<<1%) and a process based on this concept was judged to be impractical because of the low temperature and high energy requirements associated with condensing the sulfur. The second concept involved desulfurization using CeO2 and regeneration of the sulfided sorbent, Ce2O2S, using SO2 to produce elemental sulfur directly. No significant side reactions were observed and the reaction was found to be quite rapid over the temperature range of 500°C to 700°C. Elemental sulfur concentrations (as S2) as large as 20 mol% were produced. Limitations associated with the cerium sorbent process are concentrated in the desulfurization phase. High temperature and highly reducing coal gas such as produced in the Shell gasification process are required if high sulfur removal efficiencies are to be achieved. For example, the equilibrium H2S concentration at 800°C from a Shell gas in contact with CeO2 is about 300 ppmv, well above the allowable IGCC specification. In this case, a two-stage desulfurization process using CeO2 for bulk H2S removal following by a zinc sorbent polishing step would be required. Under appropriate conditions, however, CeO2 can be reduced to non-stoichiometric CeOn (n<2) which has significantly greater affinity for H2S. Pre-breakthrough H2S concentrations in the range of 1 ppmv to 5 ppmv were measured in sulfidation tests using CeOn at 700°C in highly reducing gases, as measured by equilibrium O2 concentration, comparable to the Shell gas. Good sorbent durability was indicated in

  10. 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

    This research project examined the feasibility of a second generation high-temperature coal gas desulfurization process in which elemental sulfur is produced directly during the sorbent regeneration phase. Two concepts were evaluated experimentally. In the first, FeS was regenerated in a H2O-O2 mixture. Large fractions of the sulfur were liberated in elemental form when the H2O-O2 ratio was large. However, the mole percent of elemental sulfur in the product was always quite small (<<1%) and a process based on this concept was judged to be impractical because of the low temperature and high energy requirements associated with condensing the sulfur. The second concept involved desulfurization using CeO2 and regeneration of the sulfided sorbent, Ce2O2S, using SO2 to produce elemental sulfur directly. No significant side reactions were observed and the reaction was found to be quite rapid over the temperature range of 500C to 700C. Elemental sulfur concentrations (as S2) as large as 20 mol% were produced. Limitations associated with the cerium sorbent process are concentrated in the desulfurization phase. High temperature and highly reducing coal gas such as produced in the Shell gasification process are required if high sulfur removal efficiencies are to be achieved. For example, the equilibrium H2S concentration at 800C from a Shell gas in contact with CeO2 is about 300 ppmv, well above the allowable IGCC specification. In this case, a two-stage desulfurization process using CeO2 for bulk H2S removal following by a zinc sorbent polishing step would be required. Under appropriate conditions, however, CeO2 can be reduced to non-stoichiometric CeOn (n<2) which has significantly greater affinity for H2S. Pre-breakthrough H2S concentrations in the range of 1 ppmv to 5 ppmv were measured in sulfidation tests using CeOn at 700C in highly reducing gases, as measured by equilibrium O2 concentration, comparable to the Shell gas. Good sorbent durability was indicated in a

  11. Determination of sulfur in steels by isotope dilution mass spectrometry after dissolution with sealed tube

    International Nuclear Information System (INIS)

    Watanabe, Kazuo

    1981-01-01

    The scaled tube dissolution technique was studied for the complete conversion of sulfur in steels to sulfate. Isotope dilution mass spectrometry was used for the determination of sulfur in the sulfate. Sample (0.5 g) was dissolved in nitric acid (7 ml) and hydrochloric acid (3 ml) in a scaled borosilicate glass tube on being heated above 180 0 C overnight. Nitrate ions were removed by repeated evaporation with hydrochloric acid. The residue was dissolved in hydrochloric acid. Sulfate was reduced with a mixture of hydrochloric, hydroiodic and hypophosphorous acids; hydrogen sulfide evolved was absorbed in cadmium acetate solution, then converted to silver sulfide, which was burned to sulfur dioxide in pure oxygen at low pressure, for isotopic analysis. Analytical blank in whole procedure was 0.8 μg of sulfur. This technique was applied to the determination of sulfur in NBS low alloy steels. The principal cause of low values obtained by the open beaker dissolution technique was evaporation losses of sulfur as sulfur dioxide during the dissolution. (author)

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

    Science.gov (United States)

    Chen, Luguang; Bhattacharya, Sankar

    2013-02-05

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

  13. Mechanical cues in orofacial tissue engineering and regenerative medicine

    NARCIS (Netherlands)

    Brouwer, K.M.; Lundvig, D.M.S.; Middelkoop, E.; Wagener, F.A.D.T.; Von den Hoff, J.W.

    2015-01-01

    Cleft lip and palate patients suffer from functional, aesthetical, and psychosocial problems due to suboptimal regeneration of skin, mucosa, and skeletal muscle after restorative cleft surgery. The field of tissue engineering and regenerative medicine (TE/RM) aims to restore the normal physiology of

  14. CIRM Alpha Stem Cell Clinics: Collaboratively Addressing Regenerative Medicine Challenges.

    Science.gov (United States)

    Jamieson, Catriona H M; Millan, Maria T; Creasey, Abla A; Lomax, Geoff; Donohoe, Mary E; Walters, Mark C; Abedi, Mehrdad; Bota, Daniela A; Zaia, John A; Adams, John S

    2018-06-01

    The California Institute for Regenerative Medicine (CIRM) Alpha Stem Cell Clinic (ASCC) Network was launched in 2015 to address a compelling unmet medical need for rigorous, FDA-regulated, stem cell-related clinical trials for patients with challenging, incurable diseases. Here, we describe our multi-center experiences addressing current and future challenges. Copyright © 2018 Elsevier Inc. All rights reserved.

  15. Emdogain in regenerative periodontal therapy. A review of the literature.

    NARCIS (Netherlands)

    Sculean, A.; Windisch, P.; Dori, F.; Keglevich, T.; Molnar, B.; Gera, I.

    2007-01-01

    The goal of regenerative periodontal therapy is the reconstitution of the lost periodontal structures (i.e. the new formation of root cementum, periodontal ligament and alveolar bone). Results from basic research have pointed to the important role of the enamel matrix protein derivative (EMD) in the

  16. Kwantificatie van de invloed van regen op de verkeerdoorstroming

    NARCIS (Netherlands)

    Calvert, S.C.; Van Stralen, W.; Molin, E.J.E.

    2013-01-01

    Kwantificatie van de invloed van regen op de verkeerdoorstroming Het is bekend dat het weer invloed heeft op het verkeer op snelwegen, en in het bijzonder filevorming. Op de eerste plaats wordt de wegcapaciteit tijdelijk beïnvloed door een verandering in rijgedrag van bestuurders. Ten tweede

  17. Stem cell bioprinting for applications in regenerative medicine.

    Science.gov (United States)

    Tricomi, Brad J; Dias, Andrew D; Corr, David T

    2016-11-01

    Many regenerative medicine applications seek to harness the biologic power of stem cells in architecturally complex scaffolds or microenvironments. Traditional tissue engineering methods cannot create such intricate structures, nor can they precisely control cellular position or spatial distribution. These limitations have spurred advances in the field of bioprinting, aimed to satisfy these structural and compositional demands. Bioprinting can be defined as the programmed deposition of cells or other biologics, often with accompanying biomaterials. In this concise review, we focus on recent advances in stem cell bioprinting, including performance, utility, and applications in regenerative medicine. More specifically, this review explores the capability of bioprinting to direct stem cell fate, engineer tissue(s), and create functional vascular networks. Furthermore, the unique challenges and concerns related to bioprinting living stem cells, such as viability and maintaining multi- or pluripotency, are discussed. The regenerative capacity of stem cells, when combined with the structural/compositional control afforded by bioprinting, provides a unique and powerful tool to address the complex demands of tissue engineering and regenerative medicine applications. © 2016 New York Academy of Sciences.

  18. Regenerative Snubber For GTO-Commutated SCR Inverter

    Science.gov (United States)

    Rippel, Wally E.; Edwards, Dean B.

    1992-01-01

    Proposed regenerative snubbing circuit substituted for dissipative snubbing circuit in inverter based on silicon controlled rectifiers (SCR's) commutated by gate-turn-off thyristor (GTO). Intended to reduce loss of power that occurs in dissipative snubber. Principal criteria in design: low cost, simplicity, and reliability.

  19. Conditional approval: Japan lowers the bar for regenerative medicine products.

    Science.gov (United States)

    Sipp, Douglas

    2015-04-02

    A new system for conditional approval of regenerative medicine products will allow products of undetermined efficacy to enter the Japanese market. The potential scientific, economic, and ethical implications of this program highlight the need for further discussion and refinement. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Maximum Safety Regenerative Power Tracking for DC Traction Power Systems

    Directory of Open Access Journals (Sweden)

    Guifu Du

    2017-02-01

    Full Text Available Direct current (DC traction power systems are widely used in metro transport systems, with running rails usually being used as return conductors. When traction current flows through the running rails, a potential voltage known as “rail potential” is generated between the rails and ground. Currently, abnormal rises of rail potential exist in many railway lines during the operation of railway systems. Excessively high rail potentials pose a threat to human life and to devices connected to the rails. In this paper, the effect of regenerative power distribution on rail potential is analyzed. Maximum safety regenerative power tracking is proposed for the control of maximum absolute rail potential and energy consumption during the operation of DC traction power systems. The dwell time of multiple trains at each station and the trigger voltage of the regenerative energy absorbing device (READ are optimized based on an improved particle swarm optimization (PSO algorithm to manage the distribution of regenerative power. In this way, the maximum absolute rail potential and energy consumption of DC traction power systems can be reduced. The operation data of Guangzhou Metro Line 2 are used in the simulations, and the results show that the scheme can reduce the maximum absolute rail potential and energy consumption effectively and guarantee the safety in energy saving of DC traction power systems.

  1. Turning Regenerative Medicine Breakthrough Ideas and Innovations into Commercial Products.

    Science.gov (United States)

    Bayon, Yves; Vertès, Alain A; Ronfard, Vincent; Culme-Seymour, Emily; Mason, Chris; Stroemer, Paul; Najimi, Mustapha; Sokal, Etienne; Wilson, Clayton; Barone, Joe; Aras, Rahul; Chiesi, Andrea

    2015-12-01

    The TERMIS-Europe (EU) Industry committee intended to address the two main critical issues in the clinical/commercial translation of Advanced Therapeutic Medicine Products (ATMP): (1) entrepreneurial exploitation of breakthrough ideas and innovations, and (2) regulatory market approval. Since January 2012, more than 12,000 publications related to regenerative medicine and tissue engineering have been accepted for publications, reflecting the intense academic research activity in this field. The TERMIS-EU 2014 Industry Symposium provided a reflection on the management of innovation and technological breakthroughs in biotechnology first proposed to contextualize the key development milestones and constraints of allocation of financial resources, in the development life-cycle of radical innovation projects. This was illustrated with the biofuels story, sharing similarities with regenerative medicine. The transition was then ensured by an overview of the key identified challenges facing the commercialization of cell therapy products as ATMP examples. Real cases and testimonies were then provided by a palette of medical technologies and regenerative medicine companies from their commercial development of cell and gene therapy products. Although the commercial development of ATMP is still at the proof-of-concept stage due to technology risks, changing policies, changing markets, and management changes, the sector is highly dynamic with a number of explored therapeutic approaches, developed by using a large diversity of business models, both proposed by the experience, pitfalls, and successes of regenerative medicine pioneers, and adapted to the constraint resource allocation and environment in radical innovation projects.

  2. Regulators of pluripotency and their implications in regenerative medicine

    Directory of Open Access Journals (Sweden)

    El-Badawy A

    2015-04-01

    Full Text Available Ahmed El-Badawy, Nagwa El-Badri Center of Excellence for Stem Cells and Regenerative Medicine, Zewail City of Science and Technology, Giza, Egypt Abstract: The ultimate goal of regenerative medicine is to replace damaged tissues with new functioning ones. This can potentially be accomplished by stem cell transplantation. While stem cell transplantation for blood diseases has been increasingly successful, widespread application of stem cell therapy in the clinic has shown limited results. Despite successful efforts to refine existing methodologies and to develop better ones for reprogramming, clinical application of stem cell therapy suffers from issues related to the safety of the transplanted cells, as well as the low efficiency of reprogramming technology. Better understanding of the underlying mechanism(s involved in pluripotency should accelerate the clinical application of stem cell transplantation for regenerative purposes. This review outlines the main decision-making factors involved in pluripotency, focusing on the role of microRNAs, epigenetic modification, signaling pathways, and toll-like receptors. Of special interest is the role of toll-like receptors in pluripotency, where emerging data indicate that the innate immune system plays a vital role in reprogramming. Based on these data, we propose that nongenetic mechanisms for reprogramming provide a novel and perhaps an essential strategy to accelerate application of regenerative medicine in the clinic. Keywords: dedifferentiation, transdifferentiation, reprogramming, pluripotency, microRNAs, epigenetic modifications, signaling pathways, toll-like receptors

  3. MicroRNAs in Tissue Engineering and Regenerative Medicine

    NARCIS (Netherlands)

    Krenning, Guido; Harmsen, Martin; Sen, Chandan

    2015-01-01

    The body has a large regenerative capacity to cope with the continuous adverse challenges of high-calorie diets, aging, inflammation, and wear and tear, as well as acute injuries such as myocardial infarction. However, if the amount of sustained damage exceeds the body’s repair capacity,

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

    Science.gov (United States)

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

    2015-06-01

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

  5. 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

  6. A regenerative biology view on artificial tissue construction and 3D bioprinting: what may we learn from natural regenerative phenomena?

    DEFF Research Database (Denmark)

    Lauridsen, Henrik

    2017-01-01

    The implications of the low tissue regenerative potential in humans are severe and widespread. Several of our major diseases are direct results of this deficiency that leaves us vulnerable to events of tissue damage. This is opposed to some animal groups, such as the urodele amphibians (salamanders...

  7. Desulfurization of organic sulfur from lignite by an electron transfer process

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-10-15

    This study is an attempt to desulfurize organic sulfur from lignite samples with ferrocyanide ion as the electron transferring agent. Effect of temperature, particle size and concentration of ferrocyanide ion on desulfurization from the lignite samples has been investigated. The desulfurization process has been found to be continuous and gradually increases with increase of temperature from 298 to 368 K. The particle size has no significant impact on sulfur removal from the lignite samples. Particle size has no profound impact on the amount of sulfur removal. The desulfurization reaction has been found to be dependent on the concentration of potassium ferrocyanide. Gradual increase in the concentration of potassium ferrocyanide raised the magnitude of desulfurization, but at a higher concentration, the variation is not significant.

  8. Spleen removal

    Science.gov (United States)

    ... spleen. Sickle cell anemia . Splenic artery aneurysm (rare). Trauma to the spleen. Risks Risks for anesthesia and surgery in general ... removal - series References Brandow AM, Camitta BM. Hyposplenism, splenic trauma, and splenectomy. In: Kliegman RM, Stanton BF, St. ...

  9. 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...

  10. Occurrence and abatement of volatile sulfur compounds during biogas production.

    Science.gov (United States)

    Andersson, Fräs Annika T; Karlsson, Anna; Svensson, Bo H; Ejlertsson, Jörgen

    2004-07-01

    Volatile sulfur compounds (VSCs) in biogas originating from a biogas production plant and from a municipal sewage water treatment plant were identified. Samples were taken at various stages of the biogas-producing process, including upgrading the gas to vehicle-fuel quality. Solid-phase microextraction was used for preconcentration of the VSCs, which were subsequently analyzed using gas chromatography in combination with mass spectrometry. Other volatile organic compounds present also were identified. The most commonly occurring VSCs in the biogas were hydrogen sulfide, carbonyl sulfide, methanethiol, dimethyl sulfide, and dimethyl disulfide, and hydrogen sulfide was not always the most abundant sulfur (S) compound. Besides VSCs, oxygenated organic compounds were commonly present (e.g., ketones, alcohols, and esters). The effect of adding iron chloride to the biogas reactor on the occurrence of VSCs also was investigated. It was found that additions of 500-g/m3 substrate gave an optimal removal of VSCs. Also, the use of a prefermentation step could reduce the amount of VSCs formed in the biogas process. Moreover, in the carbon dioxide scrubber used for upgrading the gas, VSCs were removed efficiently, leaving traces (ppbv levels). The scrubber also removed other organic compounds.

  11. Heat removing device for reactor container

    International Nuclear Information System (INIS)

    Hisamochi, Kohei; Matsumoto, Tomoyuki; Matsumoto, Masayoshi; Sato, Ken-ichi.

    1996-01-01

    A recycling loop for reactor water is disposed in a reactor pressure vessel of a BWR type reactor. Extracted reactor water from the recycling loop passes through a extracted reactor water pipeline and flows into a reactor coolant cleanup system. A pipeline for connecting the extracted reactor water pipeline and a suppression pool is disposed, and a discharged water pressurizing pump is disposed to the pipeline. Upon occurrence of emergency, discharged water from the suppression pool is pressurized by a discharged water pressurizing pump and sent to a reactor coolant cleanup system. The discharged water is cooled while passing through a sucking water cooling portion of a regenerative heat exchanger and a non-regenerative heat exchanger. Then, it is sent to a feed water pipeline passing a bypass line of a filtering desalter and a bypass line of the sucked water cooling portion of the regenerative heat exchanger, injected to the inside of the pressure vessel to cool the reactor core and remove after-heat. Then, it cools the inside of the reactor container together with coolants flown out of the pressure vessel and then returns to the suppression pool. (I.N.)

  12. Adsorption of sulfur compound utilizing rice husk ash modified with niobium

    Energy Technology Data Exchange (ETDEWEB)

    Cavalcanti, Rodrigo M.; Pessoa Júnior, Wanison A.G. [Laboratório de Catálise Química e Materiais (CATAMA), Instituto de Ciências Exatas, Universidade Federal do Amazonas (UFAM), Av. Gen. Rodrigo Otávio Jordão Ramos, 6200, 69077-000 Manaus, AM (Brazil); Braga, Valdeilson S. [Laboratório de Catálise, Centro das Ciências Exatas e das Tecnologias, Universidade Federal do Oeste da Bahia, Rua Professor José Seabra de Lemos, 316, Recanto dos Pássaros, 47808-021 Barreira, BA (Brazil); Barros, Ivoneide de C.L., E-mail: iclbarros@gmail.com [Laboratório de Catálise Química e Materiais (CATAMA), Instituto de Ciências Exatas, Universidade Federal do Amazonas (UFAM), Av. Gen. Rodrigo Otávio Jordão Ramos, 6200, 69077-000 Manaus, AM (Brazil)

    2015-11-15

    Graphical abstract: - Highlights: • Adsorbents based in RHA modified with niobium were prepared by impregnation. • The impregnation modified the particle size and topology of RHA particles. • The adsorbents were applied in sulfur removal in model liquid fuels. • The larger sulfur removal (>50%) was achieved using RHA with 5 wt.% niobium oxide. • The adsorbent show great selectivity in adsorption experiments. - Abstract: Adsorbents based in rice husk ash (RHA) modified with niobium pentoxide were prepared for impregnation methods and applied in sulfur removal in liquid fuels. The solids were characterized by X-ray diffraction, infrared spectroscopy, scanning electron microscopy, nitrogen physisorption and thermal analysis; they show that there was no qualitative change in the amorphous structure of the RHA; however, the method of impregnation could modify the particle size and topology of RHA particles. The larger sulfur removal (>50%) was achieved using RHA with 5 wt.% Nb{sub 2}O{sub 5} at a dosage of 10 g L{sup −1}, after 4 h of contact with the model fuel. The kinetic study of adsorption of thiophene showed that the models of pseudo-second order and intra-particle diffusion best fit the experimental data. The adsorption experiments with the thiophenic derivatives compounds show a large selectivity of the adsorbent.

  13. Adsorption of sulfur compound utilizing rice husk ash modified with niobium

    International Nuclear Information System (INIS)

    Cavalcanti, Rodrigo M.; Pessoa Júnior, Wanison A.G.; Braga, Valdeilson S.; Barros, Ivoneide de C.L.

    2015-01-01

    Graphical abstract: - Highlights: • Adsorbents based in RHA modified with niobium were prepared by impregnation. • The impregnation modified the particle size and topology of RHA particles. • The adsorbents were applied in sulfur removal in model liquid fuels. • The larger sulfur removal (>50%) was achieved using RHA with 5 wt.% niobium oxide. • The adsorbent show great selectivity in adsorption experiments. - Abstract: Adsorbents based in rice husk ash (RHA) modified with niobium pentoxide were prepared for impregnation methods and applied in sulfur removal in liquid fuels. The solids were characterized by X-ray diffraction, infrared spectroscopy, scanning electron microscopy, nitrogen physisorption and thermal analysis; they show that there was no qualitative change in the amorphous structure of the RHA; however, the method of impregnation could modify the particle size and topology of RHA particles. The larger sulfur removal (>50%) was achieved using RHA with 5 wt.% Nb 2 O 5 at a dosage of 10 g L −1 , after 4 h of contact with the model fuel. The kinetic study of adsorption of thiophene showed that the models of pseudo-second order and intra-particle diffusion best fit the experimental data. The adsorption experiments with the thiophenic derivatives compounds show a large selectivity of the adsorbent.

  14. Prehydrolysis of aspen wood with water and with dilute aqueous sulfuric acid

    Science.gov (United States)

    Edward L. Springer; John F. Harris

    1982-01-01

    Water prehydrolysis of aspen wood was compared with 0.40% sulfuric acid prehydrolysis at a reaction temperature of 170°C. Acid prehydrolysis gave much higher yields of total anhydroxylose units in the prehydrolyzate and removed significantly less anhydroglucose from the wood than did the water treatment. At maximum yields of total anhydroxylose units in the...

  15. Copper-Sulfate Pentahydrate as a Product of the Waste Sulfuric Acid Solution Treatment

    OpenAIRE

    Marković, Radmila; Stevanović, Jasmina; Avramović, Ljiljana; Nedeljković, Dragutin; Jugović, Branimir; Stajić Trošić, Jasna; Gvozdenović, Milica M.

    2012-01-01

    The aim of this study is synthesis of copper-sulfate pentahydrate from the waste sulfuric acid solution-mother liquor generated during the regeneration process of copper bleed solution. Copper is removed from the mother liquor solution in the process of the electrolytic treatment using the insoluble lead anodes alloyed with 6 mass pct of antimony on the industrial-scale equipment. As the result of the decopperization process, copper is removed in the form of the cathode sludge and is precipit...

  16. SYNTHESIS OF SULFUR-BASED WATER TREATMENT AGENT FROM SULFUR DIOXIDE WASTE STREAMS

    Energy Technology Data Exchange (ETDEWEB)

    Robert C. Brown; Maohong Fan; Adrienne Cooper

    2004-11-01

    Absorption of sulfur dioxide from a simulated flue gas was investigated for the production of polymeric ferric sulfate (PFS), a highly effective coagulant useful in treatment of drinking water and wastewater. The reaction for PFS synthesis took place near atmospheric pressure and at temperatures of 30-80 C. SO{sub 2} removal efficiencies greater than 90% were achieved, with ferrous iron concentrations in the product less than 0.1%. A factorial analysis of the effect of temperature, oxidant dosage, SO{sub 2} concentration, and gas flow rate on SO{sub 2} removal efficiency was carried out, and statistical analyses are conducted. The solid PFS was also characterized with different methods. Characterization results have shown that PFS possesses both crystalline and non-crystalline structure. The kinetics of reactions among FeSO{sub 4} {center_dot} 7H{sub 2}O, NaHSO{sub 3} and NaClO{sub 3} was investigated. Characterizations of dry PFS synthesized from SO{sub 2} show the PFS possesses amorphous structure, which is desired for it to be a good coagulant in water and wastewater treatment. A series of lab-scale experiments were conducted to evaluate the performance of PFS synthesized from waste sulfur dioxide, ferrous sulfate and sodium chlorate. The performance assessments were based on the comparison of PFS and other conventional and new coagulants for the removal of turbidity and arsenic under different laboratory coagulant conditions. Pilot plant studies were conducted at Des Moines Water Works in Iowa and at the City of Savannah Industrial and Domestic (I&D) Water Treatment Plant in Port Wentworth, Georgia. PFS performances were compared with those of conventional coagulants. The tests in both water treatment plants have shown that PFS is, in general, comparable or better than other coagulants in removal of turbidity and organic substances. The corrosion behavior of polymeric ferric sulfate (PFS) prepared from SO{sub 2} and ferric chloride (FC) were compared. Results

  17. Sulfur Rich Coal Gasification and Low Impact Methanol Production

    Directory of Open Access Journals (Sweden)

    Andrea Bassani

    2018-03-01

    Full Text Available In recent times, the methanol was employed in numerous innovative applications and is a key compound widely used as a building block or intermediate for producing synthetic hydrocarbons, solvents, energy storage medium and fuel. It is a source of clean, sustainable energy that can be produced from traditional and renewable sources: natural gas, coal, biomass, landfill gas and power plant or industrial emissions. An innovative methanol production process from coal gasification is proposed in this work. A suitable comparison between the traditional coal to methanol process and the novel one is provided and deeply discussed. The most important features, with respect to the traditional ones, are the lower carbon dioxide emissions (about 0.3% and the higher methanol production (about 0.5% without any addition of primary sources. Moreover, it is demonstrated that a coal feed/fuel with a high sulfur content allows higher reductions of carbon dioxide emissions. The key idea is to convert hydrogen sulfide and carbon dioxide into syngas (a mixture of hydrogen and carbon monoxide by means of a regenerative thermal reactor. This is the Acid Gas to Syngas technology, a completely new and effective route of processing acid gases. The main concept is to feed an optimal ratio of hydrogen sulphide and carbon monoxide and to preheat the inlet acid gas before the combustion. The reactor is simulated using a detailed kinetic scheme.

  18. 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)

  19. Regenerative medicine using dental pulp stem cells for liver diseases.

    Science.gov (United States)

    Ohkoshi, Shogo; Hara, Hajime; Hirono, Haruka; Watanabe, Kazuhiko; Hasegawa, Katsuhiko

    2017-02-06

    Acute liver failure is a refractory disease and its prognosis, if not treated using liver transplantation, is extremely poor. It is a good candidate for regenerative medicine, where stem cell-based therapies play a central role. Mesenchymal stem cells (MSCs) are known to differentiate into multiple cell lineages including hepatocytes. Autologous cell transplant without any foreign gene induction is feasible using MSCs, thereby avoiding possible risks of tumorigenesis and immune rejection. Dental pulp also contains an MSC population that differentiates into hepatocytes. A point worthy of special mention is that dental pulp can be obtained from deciduous teeth during childhood and can be subsequently harvested when necessary after deposition in a tooth bank. MSCs have not only a regenerative capacity but also act in an anti-inflammatory manner via paracrine mechanisms. Promising efficacies and difficulties with the use of MSC derived from teeth are summarized in this review.

  20. The Impact of Biomechanics in Tissue Engineering and Regenerative Medicine

    Science.gov (United States)

    Butler, David L.; Goldstein, Steven A.; Guo, X. Edward; Kamm, Roger; Laurencin, Cato T.; McIntire, Larry V.; Mow, Van C.; Nerem, Robert M.; Sah, Robert L.; Soslowsky, Louis J.; Spilker, Robert L.; Tranquillo, Robert T.

    2009-01-01

    Biomechanical factors profoundly influence the processes of tissue growth, development, maintenance, degeneration, and repair. Regenerative strategies to restore damaged or diseased tissues in vivo and create living tissue replacements in vitro have recently begun to harness advances in understanding of how cells and tissues sense and adapt to their mechanical environment. It is clear that biomechanical considerations will be fundamental to the successful development of clinical therapies based on principles of tissue engineering and regenerative medicine for a broad range of musculoskeletal, cardiovascular, craniofacial, skin, urinary, and neural tissues. Biomechanical stimuli may in fact hold the key to producing regenerated tissues with high strength and endurance. However, many challenges remain, particularly for tissues that function within complex and demanding mechanical environments in vivo. This paper reviews the present role and potential impact of experimental and computational biomechanics in engineering functional tissues using several illustrative examples of past successes and future grand challenges. PMID:19583462

  1. Regenerative Endodontic Treatment of a Maxillary Mature Premolar

    Directory of Open Access Journals (Sweden)

    Qingan Xu

    2018-01-01

    Full Text Available Regenerative endodontic treatment was performed on a mature maxillary premolar diagnosed as chronic pulpitis. The root canals were chemomechanically prepared and placed intracanal medicaments at the first appointment. Then 2 weeks later, a blood clot was created in the canals, over which mineral trioxide aggregate was placed. At 6-month follow-up, cementum-like tissue seemed to be formed in the root canal along with nearly recovered pulp vitality. At 12-month recall, the radiographic results revealed evidence of root wall thickening. At 30-month recall, no periapical lesion was found. This case report indicates that regenerative endodontic treatment for the mature premolar is feasible. More cases are needed for further validation.

  2. Adipose-derived mesenchymal stem cells and regenerative medicine.

    Science.gov (United States)

    Konno, Masamitsu; Hamabe, Atsushi; Hasegawa, Shinichiro; Ogawa, Hisataka; Fukusumi, Takahito; Nishikawa, Shimpei; Ohta, Katsuya; Kano, Yoshihiro; Ozaki, Miyuki; Noguchi, Yuko; Sakai, Daisuke; Kudoh, Toshihiro; Kawamoto, Koichi; Eguchi, Hidetoshi; Satoh, Taroh; Tanemura, Masahiro; Nagano, Hiroaki; Doki, Yuichiro; Mori, Masaki; Ishii, Hideshi

    2013-04-01

    Adipose tissue-derived mesenchymal stem cells (ADSCs) are multipotent and can differentiate into various cell types, including osteocytes, adipocytes, neural cells, vascular endothelial cells, cardiomyocytes, pancreatic β-cells, and hepatocytes. Compared with the extraction of other stem cells such as bone marrow-derived mesenchymal stem cells (BMSCs), that of ADSCs requires minimally invasive techniques. In the field of regenerative medicine, the use of autologous cells is preferable to embryonic stem cells or induced pluripotent stem cells. Therefore, ADSCs are a useful resource for drug screening and regenerative medicine. Here we present the methods and mechanisms underlying the induction of multilineage cells from ADSCs. © 2013 The Authors Development, Growth & Differentiation © 2013 Japanese Society of Developmental Biologists.

  3. Spacecraft Radiator Freeze Protection Using a Regenerative Heat Exchanger

    Science.gov (United States)

    Ungar, Eugene K.; Schunk, Richard G.

    2011-01-01

    An active thermal control system architecture has been modified to include a regenerative heat exchanger (regenerator) inboard of the radiator. Rather than using a radiator bypass valve a regenerative heat exchanger is placed inboard of the radiators. A regenerator cold side bypass valve is used to set the return temperature. During operation, the regenerator bypass flow is varied, mixing cold radiator return fluid and warm regenerator outlet fluid to maintain the system setpoint. At the lowest heat load for stable operation, the bypass flow is closed off, sending all of the flow through the regenerator. This lowers the radiator inlet temperature well below the system set-point while maintaining full flow through the radiators. By using a regenerator bypass flow control to maintain system setpoint, the required minimum heat load to avoid radiator freezing can be reduced by more than half compared to a radiator bypass system.

  4. Exergy analysis for combined regenerative Brayton and inverse Brayton cycles

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zelong; Chen, Lingen; Sun, Fengrui [College of Naval Architecture and Power, Naval University of Engineering, Wuhan 430033 (China)

    2012-07-01

    This paper presents the study of exergy analysis of combined regenerative Brayton and inverse Brayton cycles. The analytical formulae of exergy loss and exergy efficiency are derived. The largest exergy loss location is determined. By taking the maximum exergy efficiency as the objective, the choice of bottom cycle pressure ratio is optimized by detailed numerical examples, and the corresponding optimal exergy efficiency is obtained. The influences of various parameters on the exergy efficiency and other performances are analyzed by numerical calculations.

  5. Introducing regenerative design and circularity into architectural and engineering curriculum

    OpenAIRE

    Attia, Shady

    2016-01-01

    Looking today to the challenges for planning and design of sustainable built environment including, carbon emissions, climate change, human health, water problems, biodiversity, scarcity of resources, depletion of fossil fuel, population growth and urbanization; sustainable architecture will play a key role for the sustainable development of society as a whole. In the context of an architectural design studio, this paper presents the experience of introducing the concept of regenerative desig...

  6. Regenerative liver surgeries: the alphabet soup of emerging techniques.

    Science.gov (United States)

    Parekh, Maansi; Kluger, Michael D; Griesemer, Adam; Bentley-Hibbert, Stuart

    2016-01-01

    New surgical procedures taking advantage of the regenerative abilities of the liver are being introduced as potential curative therapies to these patients either to provide auxiliary support while the native liver recovers or undergoes hypertrophy. For patients with hepatocellular carcinoma outside of the Milan criteria or bilobar colorectal metastases liver transplantation is not an option. Fulminant hepatic failure can be treated but requires life-long immunosuppression. These complex surgical procedures require high quality and directed imaging.

  7. Regenerative memory in time-delayed neuromorphic photonic resonators

    OpenAIRE

    Romeira, B.; Avó, R.; Figueiredo, José M. L.; Barland, S.; Javaloyes, J.

    2016-01-01

    We investigate a photonic regenerative memory based upon a neuromorphic oscillator with a delayed self-feedback (autaptic) connection. We disclose the existence of a unique temporal response characteristic of localized structures enabling an ideal support for bits in an optical buffer memory for storage and reshaping of data information. We link our experimental implementation, based upon a nanoscale nonlinear resonant tunneling diode driving a laser, to the paradigm of neuronal activity, the...

  8. Carbon nanotube torsional springs for regenerative braking systems

    International Nuclear Information System (INIS)

    Liu, Sanwei; Martin, Corbin; Livermore, Carol; Lashmore, David; Schauer, Mark

    2015-01-01

    The modeling and demonstration of large stroke, high energy density and high power density torsional springs based on carbon nanotube (CNT) yarns is reported, as well as their application as energy-storing actuators for regenerative braking systems. An originally untwisted CNT yarn is cyclically loaded and unloaded in torsion, with the maximum rotation angle increasing incrementally until failure. The measured average extractable energy density values are 2.9 kJ kg −1   ±  1.2 kJ kg −1 and 3.4 kJ kg −1   ±  0.4 kJ kg −1 for 1-ply CNT yarns and 2-ply CNT yarns, respectively. Additionally, a regenerative braking system is demonstrated to capture the kinetic energy of a wheel and store it as elastic energy in twisted CNT yarns. When the yarn’s twist is released, the stored energy reaccelerates the wheel. The measured energy and mean power densities of the CNT yarns in the simple regenerative braking setup are on average 3.3 kJ kg −1 and 0.67 kW kg −1 , respectively, with maximum measured values of up to 4.7 kJ kg −1 and 1.2 kW kg −1 , respectively. A slightly lower energy density of up to 1.2 kJ kg −1 and a 0.29 kW kg −1 mean power density are measured for CNT yarns in a more complex setup that mimics a unidirectional rotating regenerative braking mechanism. (paper)

  9. On the genealogy of tissue engineering and regenerative medicine.

    Science.gov (United States)

    Kaul, Himanshu; Ventikos, Yiannis

    2015-04-01

    In this article, we identify and discuss a timeline of historical events and scientific breakthroughs that shaped the principles of tissue engineering and regenerative medicine (TERM). We explore the origins of TERM concepts in myths, their application in the ancient era, their resurgence during Enlightenment, and, finally, their systematic codification into an emerging scientific and technological framework in recent past. The development of computational/mathematical approaches in TERM is also briefly discussed.

  10. Carbon nanotube torsional springs for regenerative braking systems

    Science.gov (United States)

    Liu, Sanwei; Martin, Corbin; Lashmore, David; Schauer, Mark; Livermore, Carol

    2015-10-01

    The modeling and demonstration of large stroke, high energy density and high power density torsional springs based on carbon nanotube (CNT) yarns is reported, as well as their application as energy-storing actuators for regenerative braking systems. An originally untwisted CNT yarn is cyclically loaded and unloaded in torsion, with the maximum rotation angle increasing incrementally until failure. The measured average extractable energy density values are 2.9 kJ kg-1  ±  1.2 kJ kg-1 and 3.4 kJ kg-1  ±  0.4 kJ kg-1 for 1-ply CNT yarns and 2-ply CNT yarns, respectively. Additionally, a regenerative braking system is demonstrated to capture the kinetic energy of a wheel and store it as elastic energy in twisted CNT yarns. When the yarn’s twist is released, the stored energy reaccelerates the wheel. The measured energy and mean power densities of the CNT yarns in the simple regenerative braking setup are on average 3.3 kJ kg-1 and 0.67 kW kg-1, respectively, with maximum measured values of up to 4.7 kJ kg-1 and 1.2 kW kg-1, respectively. A slightly lower energy density of up to 1.2 kJ kg-1 and a 0.29 kW kg-1 mean power density are measured for CNT yarns in a more complex setup that mimics a unidirectional rotating regenerative braking mechanism.

  11. Exergy analysis for combined regenerative Brayton and inverse Brayton cycles

    OpenAIRE

    Zelong Zhang, Lingen Chen, Fengrui Sun

    2012-01-01

    This paper presents the study of exergy analysis of combined regenerative Brayton and inverse Brayton cycles. The analytical formulae of exergy loss and exergy efficiency are derived. The largest exergy loss location is determined. By taking the maximum exergy efficiency as the objective, the choice of bottom cycle pressure ratio is optimized by detailed numerical examples, and the corresponding optimal exergy efficiency is obtained. The influences of various parameters on the exergy efficien...

  12. Hydrogen-Oxygen PEM Regenerative Fuel Cell Energy Storage System

    Science.gov (United States)

    Bents, David J.; Scullin, Vincent J.; Chang, Bei-Jiann; Johnson, Donald W.; Garcia, Christopher P.

    2005-01-01

    An introduction to the closed cycle hydrogen-oxygen polymer electrolyte membrane (PEM) regenerative fuel cell (RFC), recently constructed at NASA Glenn Research Center, is presented. Illustrated with explanatory graphics and figures, this report outlines the engineering motivations for the RFC as a solar energy storage device, the system requirements, layout and hardware detail of the RFC unit at NASA Glenn, the construction history, and test experience accumulated to date with this unit.

  13. The Regenerative Potential of Parietal Epithelial Cells in Adult Mice

    OpenAIRE

    Berger, Katja; Schulte, Kevin; Boor, Peter; Kuppe, Christoph; van Kuppevelt, Toin H.; Floege, Jürgen; Smeets, Bart; Moeller, Marcus J.

    2014-01-01

    Previously, we showed that some podocytes in juvenile mice are recruited from cells lining Bowman’s capsule, suggesting that parietal epithelial cells (PECs) are a progenitor cell population for podocytes. To investigate whether PECs also replenish podocytes in adult mice, PECs were genetically labeled in an irreversible fashion in 5-week-old mice. No significant increase in labeled podocytes was observed, even after 18 months. To accelerate a potential regenerative mechanism, progressive glo...

  14. Hair Removal

    DEFF Research Database (Denmark)

    Hædersdal, Merete

    2011-01-01

    Hair removal with optical devices has become a popular mainstream treatment that today is considered the most efficient method for the reduction of unwanted hair. Photothermal destruction of hair follicles constitutes the fundamental concept of hair removal with red and near-infrared wavelengths...... suitable for targeting follicular and hair shaft melanin: normal mode ruby laser (694 nm), normal mode alexandrite laser (755 nm), pulsed diode lasers (800, 810 nm), long-pulse Nd:YAG laser (1,064 nm), and intense pulsed light (IPL) sources (590-1,200 nm). The ideal patient has thick dark terminal hair......, white skin, and a normal hormonal status. Currently, no method of lifelong permanent hair eradication is available, and it is important that patients have realistic expectations. Substantial evidence has been found for short-term hair removal efficacy of up to 6 months after treatment with the available...

  15. Hair removal

    DEFF Research Database (Denmark)

    Haedersdal, Merete; Haak, Christina S

    2011-01-01

    Hair removal with optical devices has become a popular mainstream treatment that today is considered the most efficient method for the reduction of unwanted hair. Photothermal destruction of hair follicles constitutes the fundamental concept of hair removal with red and near-infrared wavelengths...... suitable for targeting follicular and hair shaft melanin: normal mode ruby laser (694 nm), normal mode alexandrite laser (755 nm), pulsed diode lasers (800, 810 nm), long-pulse Nd:YAG laser (1,064 nm), and intense pulsed light (IPL) sources (590-1,200 nm). The ideal patient has thick dark terminal hair......, white skin, and a normal hormonal status. Currently, no method of lifelong permanent hair eradication is available, and it is important that patients have realistic expectations. Substantial evidence has been found for short-term hair removal efficacy of up to 6 months after treatment with the available...

  16. Human dental pulp stem cells: Applications in future regenerative medicine

    Science.gov (United States)

    Potdar, Pravin D; Jethmalani, Yogita D

    2015-01-01

    Stem cells are pluripotent cells, having a property of differentiating into various types of cells of human body. Several studies have developed mesenchymal stem cells (MSCs) from various human tissues, peripheral blood and body fluids. These cells are then characterized by cellular and molecular markers to understand their specific phenotypes. Dental pulp stem cells (DPSCs) are having a MSCs phenotype and they are differentiated into neuron, cardiomyocytes, chondrocytes, osteoblasts, liver cells and β cells of islet of pancreas. Thus, DPSCs have shown great potentiality to use in regenerative medicine for treatment of various human diseases including dental related problems. These cells can also be developed into induced pluripotent stem cells by incorporation of pluripotency markers and use for regenerative therapies of various diseases. The DPSCs are derived from various dental tissues such as human exfoliated deciduous teeth, apical papilla, periodontal ligament and dental follicle tissue. This review will overview the information about isolation, cellular and molecular characterization and differentiation of DPSCs into various types of human cells and thus these cells have important applications in regenerative therapies for various diseases. This review will be most useful for postgraduate dental students as well as scientists working in the field of oral pathology and oral medicine. PMID:26131314

  17. Regenerative medicine in Europe: global competition and innovation governance.

    Science.gov (United States)

    Hogarth, Stuart; Salter, Brian

    2010-11-01

    Leading European nations with strong biotech sectors, such as the UK and Germany, are investing heavily in regenerative medicine, seeking competitive advantage in this emerging sector. However, in the broader biopharmaceutical sector, the EU is outperformed by the USA on all metrics, reflecting longstanding problems: limited venture capital finance, a fragmented patent system, and relatively weak relations between academia and industry. The current global downturn has exacerbated these difficulties. The crisis comes at a time when the EU is reframing its approach to the governance of innovation and renewing its commitment to the goal of making Europe the leading player in the global knowledge economy. If the EU is to gain a competitive advantage in the regenerative medicine sector then it must coordinate a complex multilevel governance framework that encompasses the EU, member states and regional authorities. This article takes stock of Europe's current competitive position within the global bioeconomy, drawing on a variety of metrics in the three intersecting spheres of innovation governance: science, market and society. These data then provide a platform for reviewing the problems of innovation governance faced by the EU and the strategic choices that have to be confronted in the regenerative medicine sector.

  18. Proceedings: Regenerative Medicine for Lung Diseases: A CIRM Workshop Report.

    Science.gov (United States)

    Kadyk, Lisa C; DeWitt, Natalie D; Gomperts, Brigitte

    2017-10-01

    The mission of the California Institute of Regenerative Medicine (CIRM) is to accelerate treatments to patients with unmet medical needs. In September 2016, CIRM sponsored a workshop held at the University of California, Los Angeles, to discuss regenerative medicine approaches for treatment of lung diseases and to identify the challenges remaining for advancing such treatments to the clinic and market approval. Workshop participants discussed current preclinical and clinical approaches to regenerative medicine in the lung, as well as the biology of lung stem cells and the role of stem cells in the etiology of various lung diseases. The outcome of this effort was the recognition that whereas transient cell delivery approaches are leading the way in the clinic, recent advances in the understanding of lung stem cell biology, in vitro and in vivo disease modeling, gene editing and replacement methods, and cell engraftment approaches raise the prospect of developing cures for some lung diseases in the foreseeable future. In addition, advances in in vitro modeling using lung organoids and "lung on a chip" technology are setting the stage for high quality small molecule drug screening to develop treatments for lung diseases with complex biology. Stem Cells Translational Medicine 2017;6:1823-1828. © 2017 The Authors Stem Cells Translational Medicine published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

  19. Multifunctional nanodiamonds in regenerative medicine: Recent advances and future directions.

    Science.gov (United States)

    Whitlow, Jonathan; Pacelli, Settimio; Paul, Arghya

    2017-09-10

    With recent advances in the field of nanomedicine, many new strategies have emerged for diagnosing and treating diseases. At the forefront of this multidisciplinary research, carbon nanomaterials have demonstrated unprecedented potential for a variety of regenerative medicine applications including novel drug delivery platforms that facilitate the localized and sustained release of therapeutics. Nanodiamonds (NDs) are a unique class of carbon nanoparticles that are gaining increasing attention for their biocompatibility, highly functional surfaces, optical properties, and robust physical properties. Their remarkable features have established NDs as an invaluable regenerative medicine platform, with a broad range of clinically relevant applications ranging from targeted delivery systems for insoluble drugs, bioactive substrates for stem cells, and fluorescent probes for long-term tracking of cells and biomolecules in vitro and in vivo. This review introduces the synthesis techniques and the various routes of surface functionalization that allow for precise control over the properties of NDs. It also provides an in-depth overview of the current progress made toward the use of NDs in the fields of drug delivery, tissue engineering, and bioimaging. Their future outlook in regenerative medicine including the current clinical significance of NDs, as well as the challenges that must be overcome to successfully translate the reviewed technologies from research platforms to clinical therapies will also be discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Regenerative Medicine: Advances from Developmental to Degenerative Diseases.

    Science.gov (United States)

    Blair, Nicholas F; Frith, Thomas J R; Barbaric, Ivana

    2017-01-01

    Chronic tissue and organ failure caused by an injury, disease, ageing or congenital defects represents some of the most complex therapeutic challenges and poses a significant financial healthcare burden. Regenerative medicine strategies aim to fulfil the unmet clinical need by restoring the normal tissue function either through stimulating the endogenous tissue repair or by using transplantation strategies to replace the missing or defective cells. Stem cells represent an essential pillar of regenerative medicine efforts as they provide a source of progenitors or differentiated cells for use in cell replacement therapies. Whilst significant leaps have been made in controlling the stem cell fates and differentiating them to cell types of interest, transitioning bespoke cellular products from an academic environment to off-the-shelf clinical treatments brings about a whole new set of challenges which encompass manufacturing, regulatory and funding issues. Notwithstanding the need to resolve such issues before cell replacement therapies can benefit global healthcare, mounting progress in the field has highlighted regenerative medicine as a realistic prospect for treating some of the previously incurable conditions.

  1. Ultrastructural study of the chromatoid body in planarian regenerative cells

    Energy Technology Data Exchange (ETDEWEB)

    Hori, I. (Kanazawa Medical Univ., Ishikawa (Japan))

    1982-04-01

    The present paper deals with the ultrastructural changes of chromatoid bodies in planarian regenerative cells under normal and experimental conditions. A close relationship was usually observed between chromatoid bodies and pore regions of the nuclear envelope in these cells. The chromatoid bodies continued to decrease in size during cytodifferentiation of regenerative cells, though they did not disappear entirely throughout the regeneration processes. Cytochemistry and (/sup 3/H)uridine autoradiography have shown that the chromatoid body contains RNA. The typical morphological effect of actinomycin D became apparent in three organelles, i.e., nucleolus, polysome and chromatoid body. Ultrastructural changes in nucleoli were observed to occur after actinomycin treatment (20 ..mu..g/ml). The exposure to a higher dose of actinomycin (50 ..mu..g/ml) caused a decay of chromatoid bodies while nuclear envelopes retained numerous pores. Both the nucleoli and the chromatoid bodies disappeared in the sequential stages. Within the cytoplasm of such cells disintegration of a polysomal pattern was correlated with the disappearance of chromatoid bodies. The significance of the planarian chromatoid body is discussed in relation to differentiation of the regenerative cells.

  2. 21 CFR 184.1095 - Sulfuric acid.

    Science.gov (United States)

    2010-04-01

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

  3. A sulfuric-lactic acid process for efficient purification of fungal chitosan with intact molecular weight.

    Science.gov (United States)

    Naghdi, Mitra; Zamani, Akram; Karimi, Keikhosro

    2014-02-01

    The most recent method of fungal chitosan purification, i.e., two steps of dilute sulfuric acid treatment, pretreatment of cell wall at room temperature for phosphate removal and extraction of chitosan from the phosphate free cell wall at high temperature, significantly reduces the chitosan molecular weight. This study was aimed at improvement of this method. In the pretreatment step, to choose the best conditions, cell wall of Rhizopus oryzae, containing 9% phosphate, 10% glucosamine, and 21% N-acetyl glucosamine, was treated with sulfuric, lactic, acetic, nitric, or hydrochloric acid, at room temperature. Sulfuric acid showed the best performance in phosphate removal (90%) and cell wall recovery (89%). To avoid depolymerisation of chitosan, hot sulfuric acid extraction was replaced with lactic acid treatment at room temperature, and a pure fungal chitosan was obtained (0.12 g/g cell wall). Similar pretreatment and extraction processes were conducted on pure shrimp chitosan and resulted in a chitosan recovery of higher than 87% while the reduction of chitosan viscosity was less than 15%. Therefore, the sulfuric-lactic acid method purified the fungal chitosan without significant molecular weight manipulation. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Determination of sulfur content in fuels

    International Nuclear Information System (INIS)

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

    1998-01-01

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

  5. 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.

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

    International Nuclear Information System (INIS)

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

    1979-01-01

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

  7. Reduction of sulphur dioxide emissions by pyrolysis reduction of the burning sulfur of coal, applied in the power station 'Maritsa-East 3'

    International Nuclear Information System (INIS)

    Lyutskanov, L.; Dushanov, D.

    1999-01-01

    A study for applying of the new method for reduction of the sulfur content in solid fuel reported at the Energy Forum '98 has been carried out. The calculations for using this method at the power station 'Maritsa-East 3' were made. The advantages compared to the conventional methods for removing of SO 2 from flue gases are reported. The application of this method reduces the emissions of SO 2 with 83-85%. The heat saved is equal to the heat from 13.8% of the coal. The tar obtained after removing of sulfur can be used as fuel. The expenses for transport and treatment of limestone and of obtained gypsum (needed at the conventional methods for removing the sulfur) are eliminated. The capital investments needed are smaller because of the 25-30 times smaller volume of the equipment for sulfur reduction

  8. Sulfur Dioxide Analyzer Instrument Handbook

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-05-01

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

  9. STUDY OF HYDROGEN SULFIDE REMOVAL FROM GROUNDWATER

    Directory of Open Access Journals (Sweden)

    T. Lupascu

    2013-06-01

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

  10. 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.

  11. Removing Bureaucracy

    Science.gov (United States)

    2015-08-01

    11 Defense AT&L: July–August 2015 Removing Bureaucracy Katharina G. McFarland McFarland is Assistant Secretary of Defense for Acquisition. I once...involvement from all of the Service warfighting areas came together to scrub the program requirements due to concern over the “ bureaucracy ” and... Bureaucracy ” that focuses on reducing cycle time, staffing time and all forms of inefficiencies. This includes review of those burdens that Congress

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-08-01

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

  13. Regenerative Rehabilitation: Combining Stem Cell Therapies and Activity-Dependent Stimulation.

    Science.gov (United States)

    Moritz, Chet T; Ambrosio, Fabrisia

    2017-07-01

    The number of clinical trials in regenerative medicine is burgeoning, and stem cell/tissue engineering technologies hold the possibility of becoming the standard of care for a multitude of diseases and injuries. Advances in regenerative biology reveal novel molecular and cellular targets, with potential to optimize tissue healing and functional recovery, thereby refining rehabilitation clinical practice. The purpose of this review is to (1) highlight the potential for synergy between the fields of regenerative medicine and rehabilitation, a convergence of disciplines known as regenerative rehabilitation; (2) provide translational examples of regenerative rehabilitation within the context of neuromuscular injuries and diseases; and (3) offer recommendations for ways to leverage activity dependence via combined therapy and technology, with the goal of enhancing long-term recovery. The potential clinical benefits of regenerative rehabilitation will likely become a critical aspect in the standard of care for many neurological and musculoskeletal disorders.

  14. Iodine removing means

    International Nuclear Information System (INIS)

    Takeshima, Masaki.

    1975-01-01

    Object: To employ exhaust gas from an incinerator to effect regeneration of an adsorbent such as active carbon which has adsorbed a radioactive gas such as iodine contained in the ventilating system exhaust gas of a boiling water reactor power plant. Structure: Radioactive exhaust gas such as iodine, xenon and krypton is led to an active carbon adsorbing means for removal through adsorption. When the adsorbing function of the active carbon adsorption means is reduced, the exhaust gas discharged from the incinerator is cooled down to 300 0 C and then caused to flow into the active carbon layer, and after depriving it of sulfur dioxide gas, oxides of nitrogen, daughter nuclides resulting from attenuation of radioactive gas and so forth, these being adsorbed by the carbon active layer, it is led again to the incinerator, whereby the radioactivity accompanying the regenerated gas is sealed as ash within the incinerator. Further, similarly accompanying fine active carbon particles and the like are utilized as a heat source for the incinerator. (Kamimura, M.)

  15. 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.

  16. Comparative Genomics of Green Sulfur Bacteria

    DEFF Research Database (Denmark)

    Ussery, David; Davenport, C; Tümmler, B

    2010-01-01

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

  17. Halophilic and haloalkaliphilic sulfur-oxidizing bacteria

    NARCIS (Netherlands)

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

    2013-01-01

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

  18. Stability of sulfur slopes on Io

    Science.gov (United States)

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

    1980-01-01

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

  19. Microbiological disproportionation of inorganic sulfur compounds

    DEFF Research Database (Denmark)

    Finster, Kai

    2008-01-01

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

  20. Arsenic Removal by Liquid Membranes

    Directory of Open Access Journals (Sweden)

    Tiziana Marino

    2015-03-01

    Full Text Available Water contamination with harmful arsenic compounds represents one of the most serious calamities of the last two centuries. Natural occurrence of the toxic metal has been revealed recently for 21 countries worldwide; the risk of arsenic intoxication is particularly high in Bangladesh and India but recently also Europe is facing similar problem. Liquid membranes (LMs look like a promising alternative to the existing removal processes, showing numerous advantages in terms of energy consumption, efficiency, selectivity, and operational costs. The development of different LM configurations has been a matter of investigation by several researching groups, especially for the removal of As(III and As(V from aqueous solutions. Most of these LM systems are based on the use of phosphine oxides as carriers, when the metal removal is from sulfuric acid media. Particularly promising for water treatment is the hollow fiber supported liquid membrane (HFSLM configuration, which offers high selectivity, easy transport of the targeted metal ions, large surface area, and non-stop flow process. The choice of organic extractant(s plays an essential role in the efficiency of the arsenic removal. Emulsion liquid membrane (ELM systems have not been extensively investigated so far, although encouraging results have started to appear in the literature. For such LM configuration, the most relevant step toward efficiency is the choice of the surfactant type and its concentration.

  1. [Ethical aspects of regenerative medicine, with special reference to embryonic stem cells and therapeutic cloning].

    Science.gov (United States)

    Imura, Hiroo

    2003-03-01

    Regenerative medicine is expected to be new therapeutic means for treating incurable diseases but requires serious bioethical consideration. Embryonic stem(ES) cells, that are pleuripotent cells suitable to regenerative medicine, can be used in Japan for investigative use under a strict control by guide-lines. On the other hand, use of embryo produced by nuclear transfer has not been allowed in Japan and further serious consideration is required. Some other ethical aspects of regenerative medicine are also discussed.

  2. Integration of regenerative shock absorber into vehicle electric system

    Science.gov (United States)

    Zhang, Chongxiao; Li, Peng; Xing, Shaoxu; Kim, Junyoung; Yu, Liangyao; Zuo, Lei

    2014-03-01

    Regenerative/Energy harvesting shock absorbers have a great potential to increase fuel efficiency and provide suspension damping simultaneously. In recent years there's intensive work on this topic, but most researches focus on electricity extraction from vibration and harvesting efficiency improvement. The integration of electricity generated from regenerative shock absorbers into vehicle electric system, which is very important to realize the fuel efficiency benefit, has not been investigated. This paper is to study and demonstrate the integration of regenerative shock absorber with vehicle alternator, battery and in-vehicle electrical load together. In the presented system, the shock absorber is excited by a shaker and it converts kinetic energy into electricity. The harvested electricity flows into a DC/DC converter which realizes two functions: controlling the shock absorber's damping and regulating the output voltage. The damping is tuned by controlling shock absorber's output current, which is also the input current of DC/DC converter. By adjusting the duty cycles of switches in the converter, its input impedance together with input current can be adjusted according to dynamic damping requirements. An automotive lead-acid battery is charged by the DC/DC converter's output. To simulate the working condition of combustion engine, an AC motor is used to drive a truck alternator, which also charges the battery. Power resistors are used as battery's electrical load to simulate in-vehicle electrical devices. Experimental results show that the proposed integration strategy can effectively utilize the harvested electricity and power consumption of the AC motor is decreased accordingly. This proves the combustion engine's load reduction and fuel efficiency improvement.

  3. Sulfur Chemistry in Combustion I

    DEFF Research Database (Denmark)

    Johnsson, Jan Erik; Glarborg, Peter

    2000-01-01

    of the sulphur compounds in fossil fuels and the possibilities to remove them will be given. Then the combustion of sulphur species and their influence on the combustion chemistry and especially on the CO oxidation and the NOx formation will be described. Finally the in-situ removal of sulphur in the combustion...... process by reaction between SO2 and calcium containing sorbents and the influence on the NOx chemistry will be treated....

  4. Free radical scavenging injectable hydrogels for regenerative therapy

    International Nuclear Information System (INIS)

    Komeri, Remya; Thankam, Finosh Gnanaprakasam; Muthu, Jayabalan

    2017-01-01

    Pathological free radicals generated from inflamed and infarcted cardiac tissues interferes natural tissue repair mechanisms. Hypoxic microenvironment at the injured zone of non-regenerating cardiac tissues hinders the therapeutic attempts including cell therapy. Here we report an injectable, cytocompatible, free radical scavenging synthetic hydrogel formulation for regenerative therapy. New hydrogel (PEAX-P) is prepared with D-xylitol-co-fumarate-co-poly ethylene adipate-co-PEG comaromer (PEAX) and PEGDiacrylate. PEAX-P hydrogel swells 4.9 times the initial weight and retains 100.07 kPa Young modulus at equilibrium swelling, which is suitable for cardiac applications. PEAX-P hydrogel retains elastic nature even at 60% compressive strain, which is favorable to fit with the dynamic and elastic natural tissue counterparts. PEAX-P hydrogel scavenges 51% DPPH radical, 40% hydroxyl radicals 41% nitrate radicals with 31% reducing power. The presence of hydrogel protects 62% cardiomyoblast cells treated with stress inducing media at LD 50 concentration. The free hydroxyl groups in sugar alcohols of the comacromer influence the free radical scavenging. Comparatively, PEAX-P hydrogel based on xylitol evinces slightly lower scavenging characteristics than with previously reported PEAM-P hydrogel containing mannitol having more hydroxyl groups. The possible free radical scavenging mechanism of the present hydrogel relies on the free π electrons associated with uncrosslinked fumarate bonds, hydrogen atoms associated with sugar alcohols/PEG and radical dilution by free water in the matrix. Briefly, the present PEAX-P hydrogel is a potential injectable system for combined antioxidant and regenerative therapy. - Graphical abstract: Injectable hydrogel with inherent free radical scavenging property for regenerative tissue engineering application. - Highlights: • Novel injectable hydrogel (PEAX-P) is prepared using D-xylitol-co-fumarate-co-poly ethylene adipate-co-PEG comaromer

  5. Regenerative Medicine for Epilepsy: From Basic Research to Clinical Application

    Directory of Open Access Journals (Sweden)

    Takao Yasuhara

    2013-11-01

    Full Text Available Epilepsy is a chronic neurological disorder, which presents with various forms of seizures. Traditional treatments, including medication using antiepileptic drugs, remain the treatment of choice for epilepsy. Recent development in surgical techniques and approaches has improved treatment outcomes. However, several epileptic patients still suffer from intractable seizures despite the advent of the multimodality of therapies. In this article, we initially provide an overview of clinical presentation of epilepsy then describe clinically relevant animal models of epilepsy. Subsequently, we discuss the concepts of regenerative medicine including cell therapy, neuroprotective agents, and electrical stimulation, which are reviewed within the context of our data.

  6. Free radical scavenging injectable hydrogels for regenerative therapy

    Energy Technology Data Exchange (ETDEWEB)

    Komeri, Remya [Sree Chitra Tirunal Institute for Medical Sciences and Technology, Polymer Science Division, BMT Wing, Thiruvananthapuram 695 012, Kerala State (India); Thankam, Finosh Gnanaprakasam [Dept. of Biomedical Sciences, Creighton University, 2500 California Plaza, Omaha NE68178 (United States); Muthu, Jayabalan, E-mail: mjayabalan52@gmail.com [Sree Chitra Tirunal Institute for Medical Sciences and Technology, Polymer Science Division, BMT Wing, Thiruvananthapuram 695 012, Kerala State (India)

    2017-02-01

    Pathological free radicals generated from inflamed and infarcted cardiac tissues interferes natural tissue repair mechanisms. Hypoxic microenvironment at the injured zone of non-regenerating cardiac tissues hinders the therapeutic attempts including cell therapy. Here we report an injectable, cytocompatible, free radical scavenging synthetic hydrogel formulation for regenerative therapy. New hydrogel (PEAX-P) is prepared with D-xylitol-co-fumarate-co-poly ethylene adipate-co-PEG comaromer (PEAX) and PEGDiacrylate. PEAX-P hydrogel swells 4.9 times the initial weight and retains 100.07 kPa Young modulus at equilibrium swelling, which is suitable for cardiac applications. PEAX-P hydrogel retains elastic nature even at 60% compressive strain, which is favorable to fit with the dynamic and elastic natural tissue counterparts. PEAX-P hydrogel scavenges 51% DPPH radical, 40% hydroxyl radicals 41% nitrate radicals with 31% reducing power. The presence of hydrogel protects 62% cardiomyoblast cells treated with stress inducing media at LD 50 concentration. The free hydroxyl groups in sugar alcohols of the comacromer influence the free radical scavenging. Comparatively, PEAX-P hydrogel based on xylitol evinces slightly lower scavenging characteristics than with previously reported PEAM-P hydrogel containing mannitol having more hydroxyl groups. The possible free radical scavenging mechanism of the present hydrogel relies on the free π electrons associated with uncrosslinked fumarate bonds, hydrogen atoms associated with sugar alcohols/PEG and radical dilution by free water in the matrix. Briefly, the present PEAX-P hydrogel is a potential injectable system for combined antioxidant and regenerative therapy. - Graphical abstract: Injectable hydrogel with inherent free radical scavenging property for regenerative tissue engineering application. - Highlights: • Novel injectable hydrogel (PEAX-P) is prepared using D-xylitol-co-fumarate-co-poly ethylene adipate-co-PEG comaromer

  7. Artificial organs versus regenerative medicine: is it true?

    Science.gov (United States)

    Nosé, Yukihiko; Okubo, Hisashi

    2003-09-01

    Individuals engaged in the fields of artificial kidney and artificial heart have often mistakenly stated that "the era of artificial organs is over; regenerative medicine is the future." Contrarily, we do not believe artificial organs and regenerative medicine are different medical technologies. As a matter of fact, artificial organs developed during the last 50 years have been used as a bridge to regeneration. The only difference between regenerative medicine and artificial organs is that artificial organs for the bridge to regeneration promote tissue regeneration in situ, instead of outside the body (for example, vascular prostheses, neuroprostheses, bladder substitutes, skin prostheses, bone prostheses, cartilage prostheses, ligament prostheses, etc.). All of these artificial organs are successful because tissue regeneration over a man-made prosthesis is established inside the patient's body (artificial organs to support regeneration). Another usage of the group of artificial organs for the bridge to regeneration is to sustain the functions of the patient's diseased organs during the regeneration process of the body's healthy tissues and/or organs. This particular group includes artificial kidney, hepatic assist, respiratory assist, and circulatory assist. Proof of regeneration of these healthy tissues and/or organs is demonstrated in the short-term recovery of end-stage organ failure patients (artificial organs for bridge to regeneration). A third group of artificial organs for the bridge to regeneration accelerates the regenerating process of the patient's healthy tissues and organs. This group includes neurostimulators, artificial blood (red cells) blood oxygenators, and plasmapheresis devices, including hemodiafiltrators. So-called "therapeutic artificial organs" fall into this category (artificial organs to accelerate regeneration). Thus, almost all of today's artificial organs are useful in the bridge to regeneration of healthy natural tissues and organs

  8. 77 FR 13055 - Approval and Promulgation of Implementation Plans; Alabama: Removal of State Low-Reid Vapor...

    Science.gov (United States)

    2012-03-05

    ... emissions of carbon monoxide (CO), lead and sulfur dioxide (SO 2 ) from RVP requirements. As a result, there... Promulgation of Implementation Plans; Alabama: Removal of State Low-Reid Vapor Pressure Requirement for the... sulfur and low-RVP requirements for the Birmingham Area pursuant to 211(c)(4)(C)(i). In a final...

  9. Milk removal

    OpenAIRE

    Ferneborg, Sabine

    2016-01-01

    Milk from dairy cows is a staple dietary component for humans all over the world. Regardless of whether milk is consumed in its purest, unaltered form or as high-end products such as fine cheese or ice cream, it needs to be of high quality when taken from the cow, produced at a low price and produced in a system that consider aspects such as animal health, animal welfare and sustainability. This thesis investigated the role of milk removal and the importance of residual milk on milk yield...

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

    International Nuclear Information System (INIS)

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

    1978-03-01

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

  11. 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.

  12. Influence of sulfurous oxide on plants

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, J

    1872-01-01

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

  13. Effects of sulfur dioxide on vegetation

    Energy Technology Data Exchange (ETDEWEB)

    Whitby, G S

    1939-11-11

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

  14. Clinical concepts for regenerative therapy in intrabony defects.

    Science.gov (United States)

    Cortellini, Pierpaolo; Tonetti, Maurizio S

    2015-06-01

    Evidence indicates that periodontal regeneration is an efficacious and predictable procedure for the treatment of isolated and multiple intrabony defects. Meta-analyses from systematic reviews indicate an added benefit, in terms of clinical attachment level gain, when demineralized freeze-dried bone allograft, barrier membranes and active biologic products/compounds are applied in addition to open flap debridement. On the other hand, a consistent amount of variability of the outcomes is evident among different studies and within the experimental population of each study. This variability is explained, at least in part, by different patient and defect characteristics. Patient-related factors include smoking habit, compliance with home oral hygiene and residual inflammation after cause-related therapy. Defect-associated factors include defect depth and radiographic angle, the number of residual bony walls, pocket depth and the degree of hypermobility. In addition, surgical-related variables, such as surgical skill, clinical experience and knowledge, and application of the different regenerative materials, have a significant impact on clinical outcomes. This paper presents a strategy to optimize the clinical outcomes of periodontal regeneration. The surgical design of the flap, the use of different regenerative materials and the application of appropriate passive sutures are discussed in this review along with the scientific foundations. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. Design Analysis And Applications Of A Regenerative Bicycle Ergometer

    Directory of Open Access Journals (Sweden)

    Chukwuneke J. L.

    2015-08-01

    Full Text Available Man needs to do some form of physical work in other to remain healthy this work is similar to the work done by any machine or equipment and thus should be channeled to give useful output but rather it is usually dissipated into the environment in form of heat. The regenerative bicycle ergometer takes advantage of the greater power generated by the limbs and arms thus conserves converts and stores the energy dissipated by the rider with an ideal mechanical advantage of 7.6 it strategically uses simple mechanisms to magnify its work and then converts this mechanical energy into electrical energy by the use of a dynamo with a speed ratio of 108.5 and a transmission efficiency of 89 the rider pedals 27rpm to obtain the dynamos rated input of 2600rpm giving an output of 12.6volts. The regenerative bicycle ergometer is designed and constructed to perform all the core functions of a bicycle ergometer having an allowable load of 116.5kg and a maximum resistance of 65.33N which is equivalent to a mass of 6.66kg. The energy converted is stored in a 12volts battery making its use flexible clean and meeting the energy demands of man.

  16. Cardiovascular disease: primary prevention, disease modulation and regenerative therapy.

    LENUS (Irish Health Repository)

    Sultan, Sherif

    2012-10-01

    Cardiovascular primary prevention and regeneration programs are the contemporary frontiers in functional metabolic vascular medicine. This novel science perspective harnesses our inherent ability to modulate the interface between specialized gene receptors and bioavailable nutrients in what is labeled as the nutrient-gene interaction. By mimicking a natural process through the conveyance of highly absorbable receptor specific nutrients, it is feasible to accelerate cell repair and optimize mitochondrial function, thereby achieving cardiovascular cure. We performed a comprehensive review of PubMed, EMBASE and Cochrane Review databases for articles relating to cardiovascular regenerative medicine, nutrigenomics and primary prevention, with the aim of harmonizing their roles within contemporary clinical practice. We searched in particular for large-scale randomized controlled trials on contemporary cardiovascular pharmacotherapies and their specific adverse effects on metabolic pathways which feature prominently in cardiovascular regenerative programs, such as nitric oxide and glucose metabolism. Scientific research on \\'cardiovascular-free\\' centenarians delineated that low sugar and low insulin are consistent findings. As we age, our insulin level increases. Those who can decelerate the rapidity of this process are prompting their cardiovascular rejuvenation. It is beginning to dawn on some clinicians that contemporary treatments are not only failing to impact on our most prevalent diseases, but they may be causing more damage than good. Primary prevention programs are crucial elements for a better outcome. Cardiovascular primary prevention and regeneration programs have enhanced clinical efficacy and quality of life and complement our conventional endovascular practice.

  17. Biomaterials and Culture Technologies for Regenerative Therapy of Liver Tissue.

    Science.gov (United States)

    Perez, Roman A; Jung, Cho-Rok; Kim, Hae-Won

    2017-01-01

    Regenerative approach has emerged to substitute the current extracorporeal technologies for the treatment of diseased and damaged liver tissue. This is based on the use of biomaterials that modulate the responses of hepatic cells through the unique matrix properties tuned to recapitulate regenerative functions. Cells in liver preserve their phenotype or differentiate through the interactions with extracellular matrix molecules. Therefore, the intrinsic properties of the engineered biomaterials, such as stiffness and surface topography, need to be tailored to induce appropriate cellular functions. The matrix physical stimuli can be combined with biochemical cues, such as immobilized functional groups or the delivered actions of signaling molecules. Furthermore, the external modulation of cells, through cocultures with nonparenchymal cells (e.g., endothelial cells) that can signal bioactive molecules, is another promising avenue to regenerate liver tissue. This review disseminates the recent approaches of regenerating liver tissue, with a focus on the development of biomaterials and the related culture technologies. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Induced pluripotent stem cells and their implication for regenerative medicine.

    Science.gov (United States)

    Csobonyeiova, Maria; Polak, Stefan; Koller, Jan; Danisovic, Lubos

    2015-06-01

    In 2006 Yamanaka's group showed that stem cells with properties similar to embryonic stem cells could be generated from mouse fibroblasts by introducing four genes. These cells were termed induced pluripotent stem cells (iPSCs). Because iPSCs avoid many of ethical concerns associated with the use of embryonic material, they have great potential in cell-based regenerative medicine. They are suitable also for other various purposes, including disease modelling, personalized cell therapy, drug or toxicity screening and basic research. Moreover, in the future, there might become possible to generate organs for human transplantation. Despite these progresses, several studies have raised the concern for genetic and epigenetic abnormalities of iPSCs that could contribute to immunogenicity of some cells differentiated from iPSCs. Recent methodological improvements are increasing the ease and efficacy of reprogramming, and reducing the genomic modification. However, to minimize or eliminate genetic alternations in the derived iPSC line creation, factor-free human iPSCs are necessary. In this review we discuss recent possibilities of using iPSCs for clinical applications and new advances in field of their reprogramming methods. The main goal of present article was to review the current knowledge about iPSCs and to discuss their potential for regenerative medicine.

  19. Elixir of Life: Thwarting Aging With Regenerative Reprogramming.

    Science.gov (United States)

    Beyret, Ergin; Martinez Redondo, Paloma; Platero Luengo, Aida; Izpisua Belmonte, Juan Carlos

    2018-01-05

    All living beings undergo systemic physiological decline after ontogeny, characterized as aging. Modern medicine has increased the life expectancy, yet this has created an aged society that has more predisposition to degenerative disorders. Therefore, novel interventions that aim to extend the healthspan in parallel to the life span are needed. Regeneration ability of living beings maintains their biological integrity and thus is the major leverage against aging. However, mammalian regeneration capacity is low and further declines during aging. Therefore, modalities that reinforce regeneration can antagonize aging. Recent advances in the field of regenerative medicine have shown that aging is not an irreversible process. Conversion of somatic cells to embryonic-like pluripotent cells demonstrated that the differentiated state and age of a cell is not fixed. Identification of the pluripotency-inducing factors subsequently ignited the idea that cellular features can be reprogrammed by defined factors that specify the desired outcome. The last decade consequently has witnessed a plethora of studies that modify cellular features including the hallmarks of aging in addition to cellular function and identity in a variety of cell types in vitro. Recently, some of these reprogramming strategies have been directly used in animal models in pursuit of rejuvenation and cell replacement. Here, we review these in vivo reprogramming efforts and discuss their potential use to extend the longevity by complementing or augmenting the regenerative capacity. © 2017 American Heart Association, Inc.

  20. Three-dimensional bioprinting in tissue engineering and regenerative medicine.

    Science.gov (United States)

    Gao, Guifang; Cui, Xiaofeng

    2016-02-01

    With the advances of stem cell research, development of intelligent biomaterials and three-dimensional biofabrication strategies, highly mimicked tissue or organs can be engineered. Among all the biofabrication approaches, bioprinting based on inkjet printing technology has the promises to deliver and create biomimicked tissue with high throughput, digital control, and the capacity of single cell manipulation. Therefore, this enabling technology has great potential in regenerative medicine and translational applications. The most current advances in organ and tissue bioprinting based on the thermal inkjet printing technology are described in this review, including vasculature, muscle, cartilage, and bone. In addition, the benign side effect of bioprinting to the printed mammalian cells can be utilized for gene or drug delivery, which can be achieved conveniently during precise cell placement for tissue construction. With layer-by-layer assembly, three-dimensional tissues with complex structures can be printed using converted medical images. Therefore, bioprinting based on thermal inkjet is so far the most optimal solution to engineer vascular system to the thick and complex tissues. Collectively, bioprinting has great potential and broad applications in tissue engineering and regenerative medicine. The future advances of bioprinting include the integration of different printing mechanisms to engineer biphasic or triphasic tissues with optimized scaffolds and further understanding of stem cell biology.

  1. Analysis of a Hybrid Mechanical Regenerative Braking System

    Directory of Open Access Journals (Sweden)

    Toh Xiang Wen Matthew

    2018-01-01

    Full Text Available Regenerative braking systems for conventional vehicles are gaining attention as fossil fuels continue to be depleted. The major forms of regenerative braking systems include electrical and mechanical systems, with the former being more widely adopted at present. However mechanical systems are still feasible, including the possible hybrid systems of two mechanical energy recovery systems. A literature study was made to compare the various mechanical energy recovery systems. These systems were compared based on their advantages and disadvantages with regards to energy storage, usage, and maintenance. Based on the comparison, the most promising concept appeared to be one that combined the flywheel and the pneumatic energy recovery systems. A CAD model of this hybrid system was produced to better visualise the design. This was followed by analytical modelling of the energy recovery systems. The analysis indicated that the angular velocity had an extremely significant impact on the power loss and energy efficiency. The results showed that the hybrid system can provide better efficiency but only when operating within certain parameters. Future work is required to further improve the efficiency of this hybrid system.

  2. Human neonatal cardiovascular progenitors: unlocking the secret to regenerative ability.

    Directory of Open Access Journals (Sweden)

    Tania I Fuentes

    Full Text Available Although clinical benefit can be achieved after cardiac transplantation of adult c-kit+ or cardiosphere-derived cells for myocardial repair, these stem cells lack the regenerative capacity unique to neonatal cardiovascular stem cells. Unraveling the molecular basis for this age-related discrepancy in function could potentially transform cardiovascular stem cell transplantation. In this report, clonal populations of human neonatal and adult cardiovascular progenitor cells were isolated and characterized, revealing the existence of a novel subpopulation of endogenous cardiovascular stem cells that persist throughout life and co-express both c-kit and isl1. Epigenetic profiling identified 41 microRNAs whose expression was significantly altered with age in phenotypically-matched clones. These differences were correlated with reduced proliferation and a limited capacity to invade in response to growth factor stimulation, despite high levels of growth factor receptor on progenitors isolated from adults. Further understanding of these differences may provide novel therapeutic targets to enhance cardiovascular regenerative capacity.

  3. Endothelial Jagged-1 Is Necessary for Homeostatic and Regenerative Hematopoiesis

    Directory of Open Access Journals (Sweden)

    Michael G. Poulos

    2013-09-01

    Full Text Available The bone marrow (BM microenvironment is composed of multiple niche cells that, by producing paracrine factors, maintain and regenerate the hematopoietic stem cell (HSC pool (Morrison and Spradling, 2008. We have previously demonstrated that endothelial cells support the proper regeneration of the hematopoietic system following myeloablation (Butler et al., 2010; Hooper et al., 2009; Kobayashi et al., 2010. Here, we demonstrate that expression of the angiocrine factor Jagged-1, supplied by the BM vascular niche, regulates homeostatic and regenerative hematopoiesis through a Notch-dependent mechanism. Conditional deletion of Jagged-1 in endothelial cells (Jag1(ECKO mice results in a profound decrease in hematopoiesis and premature exhaustion of the adult HSC pool, whereas quantification and functional assays demonstrate that loss of Jagged-1 does not perturb vascular or mesenchymal compartments. Taken together, these data demonstrate that the instructive function of endothelial-specific Jagged-1 is required to support the self-renewal and regenerative capacity of HSCs in the adult BM vascular niche.

  4. Regenerative Medicine for Periodontal and Peri-implant Diseases.

    Science.gov (United States)

    Larsson, L; Decker, A M; Nibali, L; Pilipchuk, S P; Berglundh, T; Giannobile, W V

    2016-03-01

    The balance between bone resorption and bone formation is vital for maintenance and regeneration of alveolar bone and supporting structures around teeth and dental implants. Tissue regeneration in the oral cavity is regulated by multiple cell types, signaling mechanisms, and matrix interactions. A goal for periodontal tissue engineering/regenerative medicine is to restore oral soft and hard tissues through cell, scaffold, and/or signaling approaches to functional and aesthetic oral tissues. Bony defects in the oral cavity can vary significantly, ranging from smaller intrabony lesions resulting from periodontal or peri-implant diseases to large osseous defects that extend through the jaws as a result of trauma, tumor resection, or congenital defects. The disparity in size and location of these alveolar defects is compounded further by patient-specific and environmental factors that contribute to the challenges in periodontal regeneration, peri-implant tissue regeneration, and alveolar ridge reconstruction. Efforts have been made over the last few decades to produce reliable and predictable methods to stimulate bone regeneration in alveolar bone defects. Tissue engineering/regenerative medicine provide new avenues to enhance tissue regeneration by introducing bioactive models or constructing patient-specific substitutes. This review presents an overview of therapies (e.g., protein, gene, and cell based) and biomaterials (e.g., resorbable, nonresorbable, and 3-dimensionally printed) used for alveolar bone engineering around teeth and implants and for implant site development, with emphasis on most recent findings and future directions. © International & American Associations for Dental Research 2015.

  5. Application of Stem Cell Technology in Dental Regenerative Medicine.

    Science.gov (United States)

    Feng, Ruoxue; Lengner, Chistopher

    2013-07-01

    In this review, we summarize the current literature regarding the isolation and characterization of dental tissue-derived stem cells and address the potential of these cell types for use in regenerative cell transplantation therapy. Looking forward, platforms for the delivery of stem cells via scaffolds and the use of growth factors and cytokines for enhancing dental stem cell self-renewal and differentiation are discussed. We aim to understand the developmental origins of dental tissues in an effort to elucidate the molecular pathways governing the genesis of somatic dental stem cells. The advantages and disadvantages of several dental stem cells are discussed, including the developmental stage and specific locations from which these cells can be purified. In particular, stem cells from human exfoliated deciduous teeth may act as a very practical and easily accessibly reservoir for autologous stem cells and hold the most value in stem cell therapy. Dental pulp stem cells and periodontal ligament stem cells should also be considered for their triple lineage differentiation ability and relative ease of isolation. Further, we address the potentials and limitations of induced pluripotent stem cells as a cell source in dental regenerative. From an economical and a practical standpoint, dental stem cell therapy would be most easily applied in the prevention of periodontal ligament detachment and bone atrophy, as well as in the regeneration of dentin-pulp complex. In contrast, cell-based tooth replacement due to decay or other oral pathology seems, at the current time, an untenable approach.

  6. Design and construction of a regenerative radiant tube burner

    International Nuclear Information System (INIS)

    Henao, Diego Alberto; Cano C, Carlos Andres; Amell Arrieta, Andres A.

    2002-01-01

    The technological development of the gas industry in Colombia, aiming at efficient and safe use of the natural gas, requires the assimilation and adaptation of new generation, technologies for this purpose in this article results are presented on the design, construction and characterization of a prototype of a burner of regenerative radiant robe with a thermal power of 9,94 kW and a factor of air 1,05. This system takes advantage of the high exit temperature of the combustion smokes, after they go trough a metallic robe where they transfer the heat by radiation, to heat a ceramic channel that has the capacity to absorbing a part of the heat of the smokes and then transferring them to a current of cold air. The benefits of air heating are a saving in fuel, compared with other processes that don't incorporate the recovery of heat from the combustion gases. In this work it was possible to probe a methodology for the design of this type of burners and to reach maximum temperatures of heating of combustion air of 377,9 centigrade degrees, using a material available in the national market, whose regenerative properties should be studied in depth

  7. Viscosity of liquid sulfur under high pressure

    International Nuclear Information System (INIS)

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

    2004-01-01

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

  8. 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).

  9. 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.

  10. 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.

  11. 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.

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

    International Nuclear Information System (INIS)

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

    1986-01-01

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

  13. Vehicle State Estimator based regenerative braking implementation on an electric vehicle to improve lateral vehicle stability

    NARCIS (Netherlands)

    Jansen, S.T.H.; van Boekel, J.J.P.; Iersel, van S.S.; Besselink, I.J.M.; Nijmeijer, H.

    2013-01-01

    The driving range of electric vehicles can be extended using regenerative braking. Regenerative braking uses the electric drive system, and therefore only the driven wheels, for decelerating the vehicle. Braking on one axle affects the stability of the vehicle, especially for road conditions with

  14. Vehicle state estimator based regenerative braking implementation on an electric vehicle to improve lateral vehicle stability

    NARCIS (Netherlands)

    Jansen, S.T.H.; Boekel, J.J.P. van; Iersel, S.S. van; Besselink, I.J.M.; Nijmeijer, H.

    2013-01-01

    The driving range of electric vehicles can be extended using regenerative braking. Regenerative braking uses the elctric drive system, and therefore only the driven wheels, for decelerating the vehicle. Braking on one axle affects the stability of the vehicle, especially for road conditions with

  15. Predicting Forest Regeneration in the Central Appalachians Using the REGEN Expert System

    Science.gov (United States)

    Lance A. Vickers; Thomas R. Fox; David L. Loftis; David A. Boucugnani

    2011-01-01

    REGEN is an expert system designed by David Loftis to predict the future species composition of dominant and codominant stems in forest stands at the onset of stem exclusion following a proposed harvest. REGEN predictions are generated using competitive rankings for advance reproduction along with other existing stand conditions. These parameters are contained within...

  16. Adaptation and validation of the REGEN expert system for the Central Appalachians

    Science.gov (United States)

    Lance A. Vickers; Thomas R. Fox; David L. Loftis; David A. Boucugnani

    2011-01-01

    REGEN is an expert system that predicts future species composition at the onset of stem exclusion using preharvest stand conditions. To extend coverage into hardwood stands of the Central Appalachians, we developed REGEN knowledge bases for four site qualities (xeric, subxeric, submesic, mesic) based on relevant literature and expert opinion. Data were collected from...

  17. 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...

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

    African Journals Online (AJOL)

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

  19. 46 CFR 151.50-21 - Sulfuric acid.

    Science.gov (United States)

    2010-10-01

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

  20. Standard values of fugacity for sulfur which are self-consistent with the low-pressure phase diagram

    Energy Technology Data Exchange (ETDEWEB)

    Marriott, Robert A., E-mail: rob.marriott@ucalgary.ca [Alberta Sulphur Research Ltd., University of Calgary, Alberta (Canada); Wan, Herman H. [Alberta Sulphur Research Ltd., University of Calgary, Alberta (Canada)

    2011-08-15

    Highlights: > We have provided a method for calculating the fugacity for elemental sulfur. > Calculated sulfur fugacities can be used in sulfur equilibrium models. > The sulfur fugacities also can be used to locate the phase changes in the low-pressure phase diagram. > We have measured the 'natural' melting point of sulfur, and found it to be T = 388.5 {+-} 0.2 K. - Abstract: A method for calculating the fugacity of pure sulfur in the {alpha}-solid, {beta}-solid and liquid phase regions has been reported for application to industrial equilibrium conditions, e.g., high-pressure solubility of sulfur in sour gas. The fugacity calculations are self-consistent with the low-pressure phase diagram. As recently discussed by Ferreira and Lobo , empirical fitting of the experimental data does not yield consistent behaviour for the low-pressure phase diagram of elemental sulfur. In particular, there is a discrepancy between the vapour pressure of {beta}-solid (monoclinic) and liquid sulfur at the fusion temperature. We have provided an alternative semi-empirical approach which allows one to calculate values of the fugacity at conditions removed from the conditions of the pure sulfur phase transitions. For our approach, we have forced the liquid vapour pressure to equal the {beta}-solid vapour pressure at the {beta}-l-g triple point corresponding to the 'natural' fusion temperature for {beta}-solid. Many studies show a higher 'observed' fusion temperature for elemental sulfur. The non-reversible conditions for 'observed' fusion conditions for elemental sulfur result from a kinetically hindered melt which causes some thermodynamic measurements to be related to a metastable S{sub 8} liquid. We have measured the 'natural' fusion temperature, T{sub fus}{sup {beta}}(exp.)=(388.5{+-}0.2)K at p = 89.9 kPa, which is consistent with literature fusion data at higher-pressures. Using our semi-empirical approach, we have used or found the

  1. Regenerative treatment of an immature, traumatized tooth with apical periodontitis: report of a case.

    Science.gov (United States)

    Cotti, Elisabetta; Mereu, Manuela; Lusso, Daniela

    2008-05-01

    This case report describes the treatment of a necrotic immature permanent central incisor with complete crown fracture, suspected root fracture, and sinus tract, which was not treated with conventional apexification techniques. Instead, a regenerative approach based on the trauma literature's methods for revascularization was provided. The root canal was gently debrided of necrotic tissue with a sharp spoon excavator and irrigated for only one third of its length with NaOCl and then medicated with calcium hydroxide. After 15 days the sinus tract had healed, and the tooth was asymptomatic. The tooth was accessed, calcium hydroxide was removed, bleeding was stimulated to form an intracanal blood clot, and mineral trioxide aggregate was placed coronally to the blood clot. After 8 months, a coronal calcified barrier was radiographically evident and accompanied with progressive thickening of the root wall and apical closure. Two and a half years after treatment was initiated, the tooth remained asymptomatic, and the sinus tract had not reappeared. The progressive increase in the thickness of the dentinal walls and subsequent apical development suggest that appropriate biologic responses can occur with this type of treatment of the necrotic immature permanent tooth with sinus tract.

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

    International Nuclear Information System (INIS)

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

    2001-01-01

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

  3. A Comprehensive Review of the Techniques on Regenerative Shock Absorber Systems

    Directory of Open Access Journals (Sweden)

    Ran Zhang

    2018-05-01

    Full Text Available In this paper, the current technologies of the regenerative shock absorber systems have been categorized and evaluated. Three drive modes of the regenerative shock absorber systems, namely the direct drive mode, the indirect drive mode and hybrid drive mode are reviewed for their readiness to be implemented. The damping performances of the three different modes are listed and compared. Electrical circuit and control algorithms have also been evaluated to maximize the power output and to deliver the premium ride comfort and handling performance. Different types of parameterized road excitations have been applied to vehicle suspension systems to investigate the performance of the regenerative shock absorbers. The potential of incorporating nonlinearity into the regenerative shock absorber design analysis is discussed. The research gaps for the comparison of the different drive modes and the nonlinearity analysis of the regenerative shock absorbers are identified and, the corresponding research questions have been proposed for future work.

  4. Mechanism analysis and evaluation methodology of regenerative braking contribution to energy efficiency improvement of electrified vehicles

    International Nuclear Information System (INIS)

    Lv, Chen; Zhang, Junzhi; Li, Yutong; Yuan, Ye

    2015-01-01

    Highlights: • The energy flow of an electric vehicle with regenerative brake is analyzed. • Methodology for measuring the regen brake contribution is discussed. • Evaluation parameters of regen brake contribution are proposed. • Vehicle tests are carried out on chassis dynamometer. • Test results verify the evaluation method and parameters proposed. - Abstract: This article discusses the mechanism and evaluation methods of contribution brought by regenerative braking to electric vehicle’s energy efficiency improvement. The energy flow of an electric vehicle considering the braking energy regeneration was analyzed. Then, methodologies for measuring the contribution made by regenerative brake to vehicle energy efficiency improvement were introduced. Based on the energy flow analyzed, two different evaluation parameters were proposed. Vehicle tests were carried out on chassis dynamometer under typical driving cycles with three different control strategies. The experimental results the difference between the proposed two evaluation parameters, and demonstrated the feasibility and effectiveness of the evaluation methodologies proposed

  5. Human resource development contributes to the creation of outstanding regenerative medicine products

    Directory of Open Access Journals (Sweden)

    Fusako Nishigaki

    2017-12-01

    Full Text Available Regenerative medicine is currently the focus of global attention. Countries all around the world are actively working to create new regenerative treatment modalities through pioneering research and novel technologies. This is wonderful news for patients who could not be treated with existing medical options. New venture businesses and companies are being established in regenerative medicine and their rapid industrialization is anticipated. However, to ensure high-quality products, human resources qualified in research and development and the manufacturing of these products are essential. The Forum for Innovative Regenerative Medicine (FIRM conducted a questionnaire of its industry members to examine the training and hiring of people in research and development, product creation, manufacturing, and more. Regenerative medicine is a brand new field; thus, many different businesses will need to cooperate together. People with a broad range of technical skills, abilities, and knowledge will be in demand, with various levels of expertise, from basic to advanced.

  6. Early Orthodontic Tooth Movement into Regenerative Bony Defects: A Case Report.

    Science.gov (United States)

    Tsai, Hui-Chen; Yao, Chung-Chen Jane; Wong, Man-Ying

    Early orthodontic tooth movement following regenerative surgery is controversial. In this case, during protraction of the maxillary right first premolar to substitute for the long-term missing maxillary right canine, Bio-Oss and Bio-Gide were used for lateral ridge augmentation at the area of the maxillary right lateral incisor and to cover the denuded surface at the buccal side of the first premolar. Orthodontic tooth movement (OTM) commenced 2 weeks after regenerative surgery. After 8 months, new bone formation was observed on the root surface of the first premolar during implant surgery. A cone beam computed tomography scan taken 1.5 years postsurgery revealed good maintenance of regenerative bone at the same site. This satisfactory outcome of early OTM following regenerative surgery suggests biomechanical stimulation may not jeopardize the regenerative effect.

  7. MRI tracking of SPIO labelled stem cells in a true regenerative environment, the regenerating limb of the axolotl

    DEFF Research Database (Denmark)

    Lauridsen, Henrik; Foldager, Casper Bindzus; Hagensen, Mette

    are generally restricted by their limited regenerative potential. Conversely, excellent animal models for regenerative studies exist in lower vertebrates such as the urodele amphibians (salamanders and newts), exemplified in the iconic Mexican axolotl (Ambystoma mexicanum) capable of regenerating whole limbs...

  8. Electrochemical reduction of sulfur dioxide in sulfolane

    Energy Technology Data Exchange (ETDEWEB)

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

    1985-09-01

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

  9. Efficient Electrolytes for Lithium–Sulfur Batteries

    International Nuclear Information System (INIS)

    Angulakshmi, Natarajan; Stephan, Arul Manuel

    2015-01-01

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

  10. Efficient Electrolytes for Lithium-Sulfur Batteries

    Directory of Open Access Journals (Sweden)

    Natarajan eAngulakshmi

    2015-05-01

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

  11. Efficient Electrolytes for Lithium–Sulfur Batteries

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-05-21

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

  12. Environmental behavior and analysis of agricultural sulfur.

    Science.gov (United States)

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

    2015-11-01

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

  13. Properties of sulfur-extended asphalt concrete

    Directory of Open Access Journals (Sweden)

    Gladkikh Vitaliy

    2016-01-01

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

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

    Science.gov (United States)

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

    2018-02-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-02-01

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

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

    International Nuclear Information System (INIS)

    Abedinzadeh, Z.

    2001-01-01

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

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

    International Nuclear Information System (INIS)

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

    2007-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Chamberland, A M; Gauthier, J M

    1977-01-01

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

  19. Potential Use of Human Periapical Cyst-Mesenchymal Stem Cells (hPCy-MSCs) as a Novel Stem Cell Source for Regenerative Medicine Applications.

    Science.gov (United States)

    Tatullo, Marco; Codispoti, Bruna; Pacifici, Andrea; Palmieri, Francesca; Marrelli, Massimo; Pacifici, Luciano; Paduano, Francesco

    2017-01-01

    Mesenchymal stem cells (MSCs) are attracting growing interest by the scientific community due to their huge regenerative potential. Thus, the plasticity of MSCs strongly suggests the utilization of these cells for regenerative medicine applications. The main issue about the clinical use of MSCs is related to the complex way to obtain them from healthy tissues; this topic has encouraged scientists to search for novel and more advantageous sources of these cells in easily accessible tissues. The oral cavity hosts several cell populations expressing mesenchymal stem cell like-features, furthermore, the access to oral and dental tissues is simple and isolation of cells is very efficient. Thus, oral-derived stem cells are highly attractive for clinical purposes. In this context, human periapical cyst mesenchymal stem cells (hPCy-MSCs) exhibit characteristics similar to other dental-derived MSCs, including their extensive proliferative potential, cell surface marker profile and the ability to differentiate into various cell types such as osteoblasts, adipocytes and neurons. Importantly, hPCy-MSCs are easily collected from the surgically removed periapical cysts; this reusing of biological waste guarantees a smart source of stem cells without any impact on the surrounding healthy tissues. In this review, we report the most interesting research topics related to hPCy-MSCs with a newsworthy discussion about the future insights. This newly discovered cell population exhibits interesting and valuable potentialities that could be of high impact in the future regenerative medicine applications.

  20. Potential Use of Human Periapical Cyst-Mesenchymal Stem Cells (hPCy-MSCs as a Novel Stem Cell Source for Regenerative Medicine Applications

    Directory of Open Access Journals (Sweden)

    Marco Tatullo

    2017-12-01

    Full Text Available Mesenchymal stem cells (MSCs are attracting growing interest by the scientific community due to their huge regenerative potential. Thus, the plasticity of MSCs strongly suggests the utilization of these cells for regenerative medicine applications. The main issue about the clinical use of MSCs is related to the complex way to obtain them from healthy tissues; this topic has encouraged scientists to search for novel and more advantageous sources of these cells in easily accessible tissues. The oral cavity hosts several cell populations expressing mesenchymal stem cell like-features, furthermore, the access to oral and dental tissues is simple and isolation of cells is very efficient. Thus, oral-derived stem cells are highly attractive for clinical purposes. In this context, human periapical cyst mesenchymal stem cells (hPCy-MSCs exhibit characteristics similar to other dental-derived MSCs, including their extensive proliferative potential, cell surface marker profile and the ability to differentiate into various cell types such as osteoblasts, adipocytes and neurons. Importantly, hPCy-MSCs are easily collected from the surgically removed periapical cysts; this reusing of biological waste guarantees a smart source of stem cells without any impact on the surrounding healthy tissues. In this review, we report the most interesting research topics related to hPCy-MSCs with a newsworthy discussion about the future insights. This newly discovered cell population exhibits interesting and valuable potentialities that could be of high impact in the future regenerative medicine applications.