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Sample records for activity recycles hydrogen

  1. A novel endo-hydrogenase activity recycles hydrogen produced by nitrogen fixation.

    Gordon Ng

    Full Text Available BACKGROUND: Nitrogen (N(2 fixation also yields hydrogen (H(2 at 1:1 stoichiometric amounts. In aerobic diazotrophic (able to grow on N(2 as sole N-source bacteria, orthodox respiratory hupSL-encoded hydrogenase activity, associated with the cell membrane but facing the periplasm (exo-hydrogenase, has nevertheless been presumed responsible for recycling such endogenous hydrogen. METHODS AND FINDINGS: As shown here, for Azorhizobium caulinodans diazotrophic cultures open to the atmosphere, exo-hydrogenase activity is of no consequence to hydrogen recycling. In a bioinformatic analysis, a novel seven-gene A. caulinodans hyq cluster encoding an integral-membrane, group-4, Ni,Fe-hydrogenase with homology to respiratory complex I (NADH: quinone dehydrogenase was identified. By analogy, Hyq hydrogenase is also integral to the cell membrane, but its active site faces the cytoplasm (endo-hydrogenase. An A. caulinodans in-frame hyq operon deletion mutant, constructed by "crossover PCR", showed markedly decreased growth rates in diazotrophic cultures; normal growth was restored with added ammonium--as expected of an H(2-recycling mutant phenotype. Using A. caulinodans hyq merodiploid strains expressing beta-glucuronidase as promoter-reporter, the hyq operon proved strongly and specifically induced in diazotrophic culture; as well, hyq operon induction required the NIFA transcriptional activator. Therefore, the hyq operon is constituent of the nif regulon. CONCLUSIONS: Representative of aerobic N(2-fixing and H(2-recycling alpha-proteobacteria, A. caulinodans possesses two respiratory Ni,Fe-hydrogenases: HupSL exo-hydrogenase activity drives exogenous H(2 respiration, and Hyq endo-hydrogenase activity recycles endogenous H(2, specifically that produced by N(2 fixation. To benefit human civilization, H(2 has generated considerable interest as potential renewable energy source as its makings are ubiquitous and its combustion yields no greenhouse gases. As

  2. Selective purge for hydrogenation reactor recycle loop

    Baker, Richard W.; Lokhandwala, Kaaeid A.

    2001-01-01

    Processes and apparatus for providing improved contaminant removal and hydrogen recovery in hydrogenation reactors, particularly in refineries and petrochemical plants. The improved contaminant removal is achieved by selective purging, by passing gases in the hydrogenation reactor recycle loop or purge stream across membranes selective in favor of the contaminant over hydrogen.

  3. Hydrogen recycling in TRIAM-1M

    Research was carried out on the particle confinement characteristics in TRIAM-1M and particle recycling. The ionized amount of neutral particles was assessed by the radiation intensity of Hα beam, and the time of particle confinement was obtained by using the equation for particle balance. Besides, by determining the quantities of supply and discharge of hydrogen gas, the particle balance in a vacuum vessel was considered, and recycling coefficient R was determined. Whereas R=0.94 in ohmic discharge, in lower hybrid current drive (LHCD) discharge, it was R=1. This result shows that in the LHCD discharge, most of the particles which were lost from plasma were supplied by recycling, and the density was maintained invariably without supplying gas to active plasma. In the superconducting strong magnetic field tokamak, TRIAM-1M, the experiment aiming at maintaining plasma for long time by the current drive using low hybrid wave has been carried out, and plasma has been maintained for more than one four. In this case, the control of plasma particles and the grasp of the behavior of particles in plasma are very important. The experimental setup, the results of Hα beam spectrometry and the spatial distribution of the radiation intensity of Hα beam, and the analysis of the results of measurement are reported. (K.I.)

  4. PHENANTHROLINE-STABILIZED PALLADIUM NANOPARTICLES IN POLYETHYLENE GLYCOL—AN ACTIVE AND RECYCLABLE CATALYST SYSTEM FOR THE SELECTIVE HYDROGENATION OF OLEFINS USING MOLECULAR HYDROGEN

    1,10-Phenanthroline-stabilized palladium nanoparticles dispersed in a polyethylene glycol (PEG) matrix is synthesized which is found to be a stable and active catalyst for the selective hydrogenation of olefins using molecular hydrogen under mild reaction conditions. A variety of...

  5. Making Recycled Paper. Learning Activity.

    Wright, Thomas

    1998-01-01

    This activity on making recycled paper includes background information, implementation directions, equipment and supply lists, drawings, and forms for students to use as they complete the activity. It may be used to develop a new curriculum or be integrated into an existing one. (JOW)

  6. Control of surface composition and hydrogen recycling by plasma conditioning

    Data from a laboratory simulator, TEXTOR, JET, and other tokamaks are used to show that oxygen and carbon surface impurities on the walls of plasma chambers are interrelated and can be manipulated by controlling the composition of the gas used for plasma surface conditioning. Not only can oxygen be reduced to low levels but carbon (and other elements) can be either removed or deposited and reacted with the substrate. In the case of carbon deposits, a thin metal-carbide layer can be formed or thicker deposits of elemental carbon can be made. Surface compositions can be reproduced easily and reversibly in a controlled way. Furthermore, these composition changes can alter the hydrogen recycling speed and plasma impurity levels by an order of magnitude or more. In the simulator we have related gas composition to surface composition changes and resulting recycling behavior. Surface oxygen levels can be reduced from 30 to less than 3 at. % in less than 45 min of discharge cleaning. Carbon and oxygen levels as well as those of other surface active impurities are interrelated. Examples are shown and discussed. Comparisons are made to show the changes in the hydrogen recycling behavior caused by various surface preparations (compositions)

  7. Gas cleaning and hydrogen sulfide removal for COREX coal gas by sorption enhanced catalytic oxidation over recyclable activated carbon desulfurizer.

    Sun, Tonghua; Shen, Yafei; Jia, Jinping

    2014-02-18

    This paper proposes a novel self-developed JTS-01 desulfurizer and JZC-80 alkaline adsorbent for H2S removal and gas cleaning of the COREX coal gas in small-scale and commercial desulfurizing devices. JTS-01 desulfurizer was loaded with metal oxide (i.e., ferric oxides) catalysts on the surface of activated carbons (AC), and the catalyst capacity was improved dramatically by means of ultrasonically assisted impregnation. Consequently, the sulfur saturation capacity and sulfur capacity breakthrough increased by 30.3% and 27.9%, respectively. The whole desulfurizing process combined selective adsorption with catalytic oxidation. Moreover, JZC-80 adsorbent can effectively remove impurities such as HCl, HF, HCN, and ash in the COREX coal gas, stabilizing the system pressure drop. The JTS-01 desulfurizer and JZC-80 adsorbent have been successfully applied for the COREX coal gas cleaning in the commercial plant at Baosteel, Shanghai. The sulfur capacity of JTS-01 desulfurizer can reach more than 50% in industrial applications. Compared with the conventional dry desulfurization process, the modified AC desulfurizers have more merit, especially in terms of the JTS-01 desulfurizer with higher sulfur capacity and low pressure drop. Thus, this sorption enhanced catalytic desulfurization has promising prospects for H2S removal and other gas cleaning. PMID:24456468

  8. A compact hydrogen recycling system using metal hydrides

    A gas recycling system to prevent losses of isotopically enriched hydrogen gas has been developed for the operation of a liquid target (2.7 l) used by the Radiative Muon Capture group at TRIUMF. The experimental requirements for high gas purity (chemical impurities below 10-9), low operating pressure (below 1 bar abs) and high loading pressure (about 10 bar needed for a palladium purifier) together with the usual hydrogen safety requirements were satisfied with a metal hydride storage device in combination with a small pump/compressor system. A description of the complete system together with its characteristic operational data are given in this paper. ((orig.))

  9. Utilization of HTGR on active carbon recycling energy system

    A new energy transformation concept based on carbon recycling, called as active carbon recycling energy system, ACRES, was proposed for a zero carbon dioxide emission process. The ACRES is driven availably by carbon dioxide free primary energy. High temperature gas cooled reactor (HTGR) is a candidate of the energy sources for ACRES. A smart ironmaking system with ACRES (iACRES) is one of application examples. The contribution of HTGR on iACRES was discussed thermodynamically in this study. A carbon material is re-used cyclically as energy carrier media in ACRES. Carbon monoxide (CO) had higher energy densities than hydrogen and was compatible with conventional process. Thus, CO was suitable recycling media for ACRES. Efficient regeneration of CO was a key technology for ACRES. A combined system of hydrogen production by water electrolysis and CO2 hydrogen reduction was candidate. CO2 direct electrolysis was also one of the candidates. HTGR was appropriate heat source for both water and CO2 electrolysises, and CO2 hydrogen reduction. Thermodynamic energy balances were calculated for both systems with HTGR for an ironmaking system. The direct system showed relatively advantage to the combined system in the stand point of enthalpy efficiency and simplicity of the process. One or two plants of HTGR are corresponding with ACRES system for one unit of conventional blast furnace. The proposed ACRES system with HTGR was expected to form the basis of a new energy industrial process that had low CO2 emission

  10. Proceedings of the workshop on elementary process in hydrogen recycling

    On September 7 and 8, 1981, a workshop was held at the Institute of Plasma Physics to review the state of the art of the study of elementary processes in hydrogen recycling in fusion reactors. The processes considered are reflection, adsorption, trapping, particle-induced emission, chemical sputtering, and diffusion in metals. The present report is the proceedings of the workshop and contains rather comprehensive reviews each on the processes considered. The workshop was held as part of the joint research program of data compilation at the Research Information Center, Institute of Plasma Physics. (author)

  11. Hydrogen recycling and transport in the helical divertor of TEXTOR

    The aim of this thesis was to investigate the hydrogen recycling at the target plates of the helical divertor in TEXTOR and by this the capability of this divertor configuration to access such favourable operational regimes. In order to study the different divertor density regimes in TEXTOR, discharges were performed in which the total plasma density was increased continuously up to the density limit. The recycling was investigated in a fixed helical divertor structure where four helical strike points with a poloidal width of about 8-10 cm are created at the divertor target plates. The experimental investigation of the hydrogen recycling was carried out using mainly spectroscopic methods supplemented by Langmuir probe, interferometric and atomic beam measurements. In the framework of this thesis a spectroscopic multi camera system has been built that facilitates the simultaneous observation of four different spectral lines, recording images of the divertor target plates and the plasma volume close to the target. The system facilitates the simultaneous measurement of the poloidal and toroidal pattern of the recycling flux at the divertor target without the need for sweeping the plasma structure. The simultaneous observation of different spectral lines reduces the uncertainty in the analysis based on several lines, as the contribution from uncertainties in the reproducibility of plasma parameters in different discharges are eliminated and only the uncertainty of the measurement method limits the accuracy. The spatial resolution of the system in poloidal and toroidal direction (0.8 mm±0.01 mm) is small compared to the separation of the helical strike points, the capability of the measurement method to resolve these structures is therefore limited by the line-of-sight integration and the penetration depth of the light emitting species. The measurements showed that the recycling flux increases linearly with increasing plasma density, a high recycling regime is not

  12. Hydrogen recycling and transport in the helical divertor of TEXTOR

    Clever, Meike

    2010-07-01

    The aim of this thesis was to investigate the hydrogen recycling at the target plates of the helical divertor in TEXTOR and by this the capability of this divertor configuration to access such favourable operational regimes. In order to study the different divertor density regimes in TEXTOR, discharges were performed in which the total plasma density was increased continuously up to the density limit. The recycling was investigated in a fixed helical divertor structure where four helical strike points with a poloidal width of about 8-10 cm are created at the divertor target plates. The experimental investigation of the hydrogen recycling was carried out using mainly spectroscopic methods supplemented by Langmuir probe, interferometric and atomic beam measurements. In the framework of this thesis a spectroscopic multi camera system has been built that facilitates the simultaneous observation of four different spectral lines, recording images of the divertor target plates and the plasma volume close to the target. The system facilitates the simultaneous measurement of the poloidal and toroidal pattern of the recycling flux at the divertor target without the need for sweeping the plasma structure. The simultaneous observation of different spectral lines reduces the uncertainty in the analysis based on several lines, as the contribution from uncertainties in the reproducibility of plasma parameters in different discharges are eliminated and only the uncertainty of the measurement method limits the accuracy. The spatial resolution of the system in poloidal and toroidal direction (0.8 mm{+-}0.01 mm) is small compared to the separation of the helical strike points, the capability of the measurement method to resolve these structures is therefore limited by the line-of-sight integration and the penetration depth of the light emitting species. The measurements showed that the recycling flux increases linearly with increasing plasma density, a high recycling regime is not

  13. Recycle of iodine-loaded silver mordenite by hydrogen reduction

    In 1977 and 1978, workers at Idaho National Engineering Laboratory (INEL) developed and tested a process for the regeneration and reuse of silver mordenite, AgZ, used to trap iodine from the dissolver off-gas stream of a nuclear fuel reprocessing plant. We were requested by the Airborne Waste Management Program Office of the Department of Energy to perform a confirmatory recycle study using repeated loadings at about 1500C with elemental iodine, each followed by a drying step at 3000C, then by iodine removal using elemental hydrogen at 5000C. The results of our study show that AgZ can be recycled. There was considerable difficulty in stripping the iodine at 5000C.; however, this step went reasonably well at 5500C or slightly higher, with no apparent loss in the iodine-loading capacity of the AgZ. Large releases of elemental iodine occurred during the drying stage and the early part of the stripping stage. Lead zeolite, which was employed in the original design to trap the HI produced, is ineffective in removal of I2. The process needs modification to handle the iodine. Severe corrosion of the stainless steel components of the system resulted from the HI-I2-H2O mixture. Monel or other halogen-resistant materials need to be examined for this application. Because of difficulty with the stripping stage and with corrosion, the experiments were terminated after 12 cycles. Thus, the maximum lifetime (cycles) of recycle AgZ has not been determined. Mechanistic studies of iodine retention by silver zeolites and of the behavior of silver atoms on the reduction stage would be of assistance in optimizing silver mordenite recycle

  14. Data compilation for radiation effects on hydrogen recycle in fusion reactor materials

    Irradiation tests of materials by hydrogen isotopes are under way, to investigate the hydrogen recycling process where exchange of fuel particles takes place between plasma and the wall of the nuclear fusion reactor. In the report, data on hydrogen irradiation are collected and reviewed from the view point of irradiation effects. Data are classified into, (1) Re-emmission, (2) Retention, (Retained hydrogen isotopes, Depth profile in the materials and Thermal desorption spectroscopy), (3) Permeation and (4) Ion impact desorption. Research activities in each area are arranged according to the date of publication, research institutes, materials investigated, so that overview of present status can be made. Then, institute, author and reference are shown for each classification with tables. The list of literature is also attached. (author)

  15. Kinetic and structural aspects of trapping and recycling of hydrogen on metallic surfaces exposed to low-pressure hydrogen plasma

    Studies of hydrogen trapping and recycling were performed on cleaned and on contaminated metallic surfaces exposed to a hydrogen discharge with parameters typical of the scrape-off layer in devices for controlled nuclear fusion research. Detailed analysis of the time- and temperature- dependent trapping and release of hydrogen upon start and termination of the discharge, respectively, allows one to draw conclusions regarding the nature of the trapping sites. These data were complemented by transmission electron microscopic investigation of the structural damage in the near-surface region and by the measurement of the amount of hydrogen trapped in the damaged area. Formation of dislocation loops at small doses and their agglomeration into an extended dislocation network at a fluence of ≤1017 cm-2 were found. The data indicate that the defects are located within a depth significantly larger than the projected range of the impinging ions. The concentration of hydrogen within this area reaches up to several tens of at . %, and its stability with respect to thermal release suggests that hydrogen is strongly trapped at the defect sites. Only a small fraction (10%--30%) of the implanted hydrogen takes part in the recycling during a 10--30 s long discharge pulse at a wall temperature of ≤300 0C. Implications of these results for the current models of hydrogen recycling are discussed

  16. Storage and hydrogen production usage of recycling material in the flexible fuel cycle initiative

    The spent fuel from a light water reactor (LWR) is treated by a LWR reprocessing in the flexible LWR fuel cycle system or 'Flexible Fuel Cycle Initiative' (FFCI) to remove uranium. The remaining fuel is recycling material and can be used to generate electricity or heat, in addition to just being stored for future recycling. This study evaluated the thermodynamics of the recycling material packed in rods for storage and the thermal usage of hydrogen production. The basic specifications for the storage system and hydrogen production system were determined by calculating the cooling properties. In the hydrogen production system, helium gas was used as both the primary and secondary working fluids, although molten salt could enhance the cooling characteristics when used as the primary working fluid. Since the heat generation rate decreased with time, the flow rate of the working fluid was changed to maintain the supply of heat power to the hydrogen production unit. Although the thermal efficiency of hydrogen production increased with temperature, the maximum temperature available for the hydrogen production system was about 873 K. The steam reforming of methane was considered the conventional method of hydrogen production for power of 15 MWt, which corresponded to 5,000 tons of LWR spent fuel. This hydrogen production system was verified as being able to provide 12,980 Nm3/h of hydrogen for about 1.1x105 fuel cell vehicles by assuming heat utilization efficiency of 81%. (author)

  17. Characterization of recycled rubber media for hydrogen sulphide (H2S) control.

    Wang, Ning; Park, Jaeyoung; Evans, Eric A; Ellis, Timothy G

    2014-01-01

    Hydrogen sulphide (H2S) adsorption capacities on recycled rubber media, tyre-derived rubber particle (TDRP), and other rubber material (ORM) have been evaluated. As part of the research, densities, moisture contents, and surface properties of TDRP and ORM have been determined. The research team findings show that TDRP and ORM are more particulate in nature and not highly porous-like activated carbon. The characteristics of surface area, pore size, and moisture content support chemisorption on the macrosurface rather than physical adsorption in micropores. For example, moisture content is essential for H2S adsorption on ORM, and an increase in moisture content results in an increase in adsorption capacity. PMID:25145205

  18. Hydrogen distribution in CVD diamond films prepared by DC arcjet operating at gas recycling mode

    2002-01-01

    Hydrogen distribution and content in diamond films deposited by DC arcjet under gas recycling mode was evaluated by nuclear reaction analysis (NRA). The films were characterized using scanning electron microscopy, X-ray diffraction and Raman spectrometry. The NRA results show that the hydrogen content in diamond films was approximately 0.6% (substrate temperature 770℃), and strongly depended on the substrate temperature. It was that the hydrogen content increased with the increase of the substrate temperature. The possibility of hydrogen trapping in the films was also discussed.

  19. Recycling a hydrogen rich residual stream to the power and steam plant

    Martinez, P. [Instituto de Energia y Desarrollo Sustentable, CNEA, CONICET, Av. del Libertador 8250 Buenos Aires, Ciudad Autonoma de Buenos Aires (Argentina); Eliceche, A.M. [Chemical Engineering Department, Universidad Nacional del Sur, PLAPIQUI-CONICET, Camino La Carrindanga Km 7 (8000) Bahia Blanca (Argentina)

    2010-06-15

    The benefits of using a residual hydrogen rich stream as a clean combustion fuel in order to reduce Carbon dioxide emissions and cost is quantified. A residual stream containing 86% of hydrogen, coming from the top of the demethanizer column of the cryogenic separation sector of an ethylene plant, is recycled to be mixed with natural gas and burned in the boilers of the utility plant to generate high pressure steam and power. The main advantage is due to the fact that the hydrogen rich residual gas has a higher heating value and less CO{sub 2} combustion emissions than the natural gas. The residual gas flowrate to be recycled is selected optimally together with other continuous and binary operating variables. A Mixed Integer Non Linear Programming problem is formulated in GAMS to select the operating conditions to minimize life cycle CO{sub 2} emissions. (author)

  20. Recycling of hydrogen isotopes - from an identification of mechanisms in TEXTOR to a wider formulation

    Mertens, Ph.; Brezinsek, S.

    2005-01-01

    The detailed physical mechanisms of hydrogen recycling are not yet completely clear. But, their understanding is required for the correct interpretation of spectroscopic measurements that are intended to provide us routinely with the total particle fluxes as well as with sound extrapolations to fusion devices of the next generation. Thanks to its large observation ports, TEXTOR provides ideal conditions for the combination of optical diagnostics based on completely different techniques, which...

  1. Hydrogen and helium recycling from stirred liquid lithium under steady state plasma bombardment

    Hirooka, Yoshi, E-mail: hirooka.yoshihiko@nifs.ac.jp [National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); The Graduate School for Advanced Studies, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); Zhou, Haishan [The Graduate School for Advanced Studies, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); Ono, Masa [Princeton Plasma Physics Laboratory, PO Box 451, Princeton, NJ 08543 (United States)

    2014-12-15

    For improved core performance via edge plasma-wall boundary control, solid and liquid lithium has been used as a plasma-facing material in a number of confinement experiments over the past several decades. Unfortunately, it is unavoidable that lithium is saturated in the surface region with implanted hydrogenic species as well as oxygen-containing impurities. For steady state operation, a flowing liquid lithium divertor with forced convection would probably be required. In the present work, the effects of liquid stirring to simulate forced convection have been investigated on the behavior of hydrogen and helium recycling from molten lithium at temperatures up to ∼350 °C. Data indicate that liquid stirring reactivates hydrogen pumping via surface de-saturation and/or uncovering impurity films, but can also induce helium release via surface temperature change.

  2. Hydrogen Purification and Recycling for an Integrated Oxygen Recovery System Architecture

    Abney, Morgan B.; Greenwood, Zachary; Wall, Terry; Miller, Lee; Wheeler, Ray

    2016-01-01

    The United States Atmosphere Revitalization life support system on the International Space Station (ISS) performs several services for the crew including oxygen generation, trace contaminant control, carbon dioxide (CO2) removal, and oxygen recovery. Oxygen recovery is performed using a Sabatier reactor developed by Hamilton Sundstrand, wherein CO2 is reduced with hydrogen in a catalytic reactor to produce methane and water. The water product is purified in the Water Purification Assembly and recycled to the Oxygen Generation Assembly (OGA) to provide O2 to the crew. This architecture results in a theoretical maximum oxygen recovery from CO2 of approximately 54% due to the loss of reactant hydrogen in Sabatier-produced methane that is currently vented outside of ISS. Plasma Methane Pyrolysis technology (PPA), developed by Umpqua Research Company, provides the capability to further close the Atmosphere Revitalization oxygen loop by recovering hydrogen from Sabatier-produced methane. A key aspect of this technology approach is to purify the hydrogen from the PPA product stream which includes acetylene, unreacted methane and byproduct water and carbon monoxide. In 2015, four sub-scale hydrogen separation systems were delivered to NASA for evaluation. These included two electrolysis single-cell hydrogen purification cell stacks developed by Sustainable Innovations, LLC, a sorbent-based hydrogen purification unit using microwave power for sorbent regeneration developed by Umpqua Research Company, and a LaNi4.6Sn0.4 metal hydride produced by Hydrogen Consultants, Inc. Here we report the results of these evaluations, discuss potential architecture options, and propose future work.

  3. Influence of adsorbed hydrogen molecules on the hydrogen permeation and recycling

    Hydrogen permeation through a thin iron membrane has been measured using a molecular hydrogen gas and/or a weakly ionized rf-discharge as particle sources. Transient and steady state values of the permeation flux φp were obtained in the regime where the surface penetration of H and the recombinative release of H2 are rate-determining. φp is then proportional to the flux density ψ of the particles which impinge on the membrane upstream. The proportionality factors depend on the nature (atomic or molecular) of the incident particles, on temperature (in particular for a molecular driving gas) and on the ratio of the surface recombinative release rate constants (2σkr)u and (2σkr)d up- and downstream, respectively. (orig.)

  4. Superpermeability to fast and thermal hydrogen particles: Applications to the pumping and recycling of hydrogen isotopes

    Livshits, A.I.; Notkin, M.E.; Samartsev, A.A.; Busnyuk, A.O.; Doroshin, A.Yu. (Surface Physics and Electronics Research Centre, Bonch-Bruyevich Electrotechnical Inst. of Communications, St. Petersburg (Russia)); Pistunovich, V.I. (Kurchatov Atomic Energy Inst., Moscow (Russia))

    1992-12-01

    Metal membranes (e.g. of Nb, Pd, Fe, etc.) may be, under certain conditions, superpermeable to hydrogen fast particles and thermal atoms, i.e. their permeability may approach that of an opening of the same area. A proposal is put forward that superpermeable membranes be installed in the ITER pumping ducts in order to isolate the major part of D/T mixture and thus to avoid its accumulation in the cryopumps that pump helium. Nonthermalized particles coming from the divertor region will be immediately pumped by the membrane, while thermalized H[sub 2] molecules will be atomized at incandescent surfaces specially introduced. The latter mechanism is experimentally demonstrated on a Nb membrane, with hydrogen atomizers made of Nb and Ta. The specific pump speed reached amounts up to [approx equal]1.5 1 s[sup -1] per 1 cm[sup 2] of the membrane area. Pumping of hydrogen is accompanied by its automatic compression beyond the membrane by a factor of [approx equal]10[sup 4]. (orig.).

  5. Recycling of radioactive mineral waste by activity separation

    The AST process is a device for the recycling of building rubble originating from the dismantling of nuclear installations. Due to the activity separation in the process, a major part of rubble which would have otherwise been radioactive waste can now be cleared. The AST process has been developed in the course of the combined research project ''Aufbereitung radioaktiver mineralischer Rueckstaede durch Aktivitaetsseparation (Recycling of radioactive mineral waste by activity separation)'' which was sponsored by the BMBF (Federal Ministry for Education and Research). The first step was to investigate the activity distribution between the various constituents of activated heavy concrete (additions: hematite, magnetite, iron cuttings), of contaminated heavy and normal concrete, as well as of composition floor. Heavy concrete with metal additions showed a selective activation of the various constituents. Contaminated rubble often exhibits a selective enrichment of the activity in the cement in contrast to the aggregate. The AST facility for activity separation was designed on the basis of these results. Trial operation with various types of building rubble was carried out using three methods for sorting, screening according to grain size, magnetic separation and radiometric sorting. The use of these three methods was adapted to the material. (orig.)

  6. Novel developments in hydrogen storage, hydrogen activation and ionic liquids

    Doroodian, Amir

    2010-12-03

    This dissertation is divided into three chapters. Recently, metal-free hydrogen activation using phosphorous compounds has been reported in science magazine. We have investigated the interaction between hydrogen and phosphorous compounds in presence of strong Lewis acids (chapter one). A new generation of metal-free hydrogen activation, using amines and strong Lewis acids with sterically demanding nature, was already developed in our group. Shortage of high storage capacity using large substitution to improve sterical effect led us to explore the amine borane derivatives, which are explained in chapter two. Due to the high storage capacity of hydrogen in aminoborane derivatives, we have explored these materials to extend hydrogen release. These compounds store hydrogen as proton and hydride on adjacent atoms or ions. These investigations resulted in developing hydrogen storage based on ionic liquids containing methyl guanidinium cation. Then we have continued to develop ionic liquids based on methyl guanidinium cation with different anions, such as tetrafluoro borate (chapter three). We have replaced these anions with transition metal anions to investigate hydrogen bonding and catalytic activity of ionic liquids. This chapter illustrates the world of ionic liquid as a green solvent for organic, inorganic and catalytic reactions and combines the concept of catalysts and solvents based on ionic liquids. The catalytic activity is investigated particularly with respect to the interaction with CO{sub 2}. (orig.)

  7. Selective Hydrogenation of Furfural to Furfuryl Alcohol in the Presence of a Recyclable Cobalt/SBA-15 Catalyst.

    Audemar, Maïté; Ciotonea, Carmen; De Oliveira Vigier, Karine; Royer, Sébastien; Ungureanu, Adrian; Dragoi, Brindusa; Dumitriu, Emil; Jérôme, François

    2015-06-01

    The hydrogenation of furfural to furfuryl alcohol was performed in the presence of a Co/SBA-15 catalyst. High selectivity (96 %) at a conversion higher than 95 % is reported over this catalytic system. As the conversion of furfural to furfuryl alcohol occurs over metallic Co sites, the effect of reduction temperature, H2 pressure, and reaction temperature were studied. Optimum reaction conditions were: 150 °C, 1.5 h, 2.0 MPa of H2 . The catalyst was recyclable, and furfuryl alcohol was recovered with a purity higher than 90 %. The effect of the solvent concentration was also studied. With a minimum of 50 wt % of solvent, the selectivity to furfuryl alcohol and the conversion of furfural remained high (both over 80 %). Likewise, the activity of the catalyst is maintained even in pure furfural, which confirms the real potential of the proposed catalytic system. This catalyst was also used in the hydrogenation of levulinic acid to produce γ-valerolactone selectively. PMID:25891431

  8. Recyclable Earth-Abundant Metal Nanoparticle Catalysts for Selective Transfer Hydrogenation of Levulinic Acid to Produce γ-Valerolactone.

    Gowda, Ravikumar R; Chen, Eugene Y-X

    2016-01-01

    Nanoparticles (NPs) derived from earth-abundant metal(0) carbonyls catalyze conversion of bio-derived levulinic acid into γ-valerolactone in up to 93% isolated yield. This sustainable and green route uses non-precious metal catalysts and can be performed in aqueous or ethanol solution without using hydrogen gas as the hydrogen source. Generation of metal NPs using microwave irradiation greatly enhances the rate of the conversion, enables the use of ethanol as both solvent and hydrogen source without forming the undesired ethyl levulinate, and affords recyclable polymer-stabilized NPs. PMID:26735911

  9. A resource recycling technique of hydrogen production from the catalytic degradation of organics in wastewater

    2008-01-01

    A resource recycling technique of hydrogen production from the catalytic degradation of organics in wastewater by aqueous phase reforming (APR) has been proposed. It is worthy of noting that this technique may be a potential way for the purification of refractory and highly toxic organics in water for hydrogen production. Hazardous organics (such as phenol, aniline, nitrobenzene, tetrahydrofuran (THF), toluene, N,N-dimethylformamide (DMF) and cyclohexanol) in water could be completely de-graded into H2 and CO2 with high selectivity over Raney Ni, and Sn-modified Raney Ni (Sn-Raney-Ni) or Pd/C catalyst under mild conditions. The experimental results operated in tubular and autoclave reactors, indicated that the degradation degree of organics and H2 selectivity could reach 100% under the optimal reaction conditions. The Sn-Raney-Ni (Sn/Ni=0.06) and Pd/C catalysts show better catalytic performances than the Raney Ni catalyst for the degradation of organics in water into H2 and CO2 by the aqueous phase reforming process.

  10. Ideas and Activities for Recycling Education for Grades K-12.

    Ayers, Jerry B., Ed.; Olberding, April H., Ed.

    In June 1997, Tennessee Technological University's Center for Manufacturing Research conducted a one-week program on plastics recycling for science teachers. The purpose of the program was to increase the teachers' basic knowledge about the importance of recycling plastics and to better prepare the teachers for teaching recycling in the classroom.…

  11. Catalytic stepwise nitrate hydrogenation in batch-recycle fixed-bed reactors

    Pd (1.0 wt.%)-Cu (0.3 wt.%) bimetallic and Pd (1.0 wt.%) monometallic catalysts were synthesized by means of incipient-wetness impregnation technique and deposited on alumina spheres (dp = 1.7 mm). The prepared catalysts were tested at T = 298 K and p(H2) = 1.0 bar in the integrated process of catalytic liquid-phase hydrogenation of aqueous nitrate solutions, in which the denitration step was carried out consecutively in separate, single-flow fixed-bed reactor units operating in a batch-recycle mode. In the first reactor packed with a Pd-Cu bimetallic catalyst, nitrate ions were transformed to nitrites at pH 12.5 with a selectivity as high as 93%; the rest was found in the form of ammonium ions. Liquid-phase nitrite hydrogenation to nitrogen in the second reactor unit packed with a Pd monometallic catalyst was conducted at low pH values of 3.7 and 4.5, respectively. Although these values are well below the pHpzc of examined catalyst (6.1), which assured that the nitrite reduction was carried out over a positively charged catalyst surface, up to 15% (23% in the presence of 5.0 g/l NaCl in the solution) of initial nitrite content was converted to undesired ammonium ions. Since a negligible amount of these species (below 0.5 mg/l) was produced at identical operating conditions over a powdered Pd/γ-Al2O3 catalyst, it is believed that the enhanced production of ammonium ions observed in the second fixed-bed reactor is due to the build-up of pH gradients in liquid-filled pores of spherical catalyst particles. Both Pd-Cu bimetallic and Pd monometallic catalysts were chemically resistant in the investigated range of pH values

  12. Solid Waste Educational Resources and Activities: Let's Reduce, Reuse, and Recycle. [CD-ROM].

    Environmental Protection Agency, Washington, DC. Solid Waste and Emergency Response.

    This contains games, activities, publications, and resources for students and teachers on how to reduce, reuse, recycle, and properly manage waste. It also contains a screen saver featuring runners-up from the Earth Day 2000 art contest. Activities and games include titles such as "Planet Protectors,""Recycle City,""Trash and Climate Change," and…

  13. Damage of the first wall in a plasma simulator and in the TCA tokamak: Implications for theoretical models of hydrogen recycling

    In order to provide data for a more realistic model of hydrogen recycling in devices for controlled nuclear fusion research the structural damage of the near surface region of the first wall has been investigated. Very high density of defects has been found within the surface layer of a thickness much larger than the projected range of the impinging ions. Preliminary interpretation of these results is given and their implications for the theoretical models of hydrogen recycling are discussed. (orig.)

  14. New biologically active hydrogen sulfide donors.

    Roger, Thomas; Raynaud, Francoise; Bouillaud, Frédéric; Ransy, Céline; Simonet, Serge; Crespo, Christine; Bourguignon, Marie-Pierre; Villeneuve, Nicole; Vilaine, Jean-Paul; Artaud, Isabelle; Galardon, Erwan

    2013-11-25

    Generous donors: The dithioperoxyanhydrides (CH3 COS)2 , (PhCOS)2 , CH3 COSSCO2 Me and PhCOSSCO2 Me act as thiol-activated hydrogen sulfide donors in aqueous buffer solution. The most efficient donor (CH3 COS)2 can induce a biological response in cells, and advantageously replace hydrogen sulfide in ex vivo vascular studies. PMID:24115650

  15. 40 CFR 260.41 - Procedures for case-by-case regulation of hazardous waste recycling activities.

    2010-07-01

    ... of hazardous waste recycling activities. 260.41 Section 260.41 Protection of Environment... Rulemaking Petitions § 260.41 Procedures for case-by-case regulation of hazardous waste recycling activities... hazardous waste recycling activities described in § 261.6(a)(2)(iii) under the provisions of § 261.6 (b)...

  16. Antitumour Activity of Chitosan Hydrogen Selenites

    2002-01-01

    Chitosans reacted with selenious acid to prepare chitosan hydrogen selenites, which were found to be growth-inhibitory against sarcoma 180 solid tumor. The results indicated that the activity also depended on the molecular weight of chitosan supports.

  17. Nanostructural activated carbons for hydrogen storage

    Li, Suoding

    A series of nanostructured activated carbons have been synthesized from poly(ether ether ketone) (PEEK), and its derivatives. These carbons, with surface area exceeding 3000 m2/g and with average pore diameters of ≤ 20 A, are proven to be superior hydrogen storage materials, with hydrogen storage capacities up to 5.5 wt% at 77 K and 45 atm. The porous texture of these carbons was controlled via optimizing three synthetic steps: thermo-oxidation of PEEK in air, pyrolysis or carbonization of the oxidized PEEK in an inert atmosphere, and activation of the pre-carbonized PEEK with metal hydroxide. Thermo-oxidation of PEEK and carbonization process were thoroughly studied. These processes have been investigated by MDSC, FTIR, TGA and Py-MS. The pyrolysis or carbonization of PEEK involves the degradation of PEEK chains in three stages. Carbon morphology, including crystallinity and porous texture, is readily controlled by adjusting carbonization temperature. Activation of PEEK carbons, using inorganic bases and other activation agents, produces microporous carbons having a very narrow pore size distribution and an average pore diameter of ≤ 20 A. The activation control parameters including activation agent, activation temperature, time and carbon morphology have been investigated extensively. High surface area activated carbon is obtained by activating a highly amorphous carbon with a high activation agent/carbon ratio at 800°C. Theoretical calculations show that the pores with smaller diameter, especially smaller than 7 A, favor hydrogen adsorption. The experimental results confirm this fact and show that: (1) the hydrogen adsorption capacity per unit surface area at 77 K and 1 bar is larger in the smaller pores, (2) gravimetric hydrogen storage capacity (W(H2)) is directly proportional to the ultramicropore (< 7 A) volume; and (3) the volumetric hydrogen storage capacity is directly proportional to the volume fraction of ultramicropores in carbon. Hydrogen

  18. DGKθ Catalytic Activity Is Required for Efficient Recycling of Presynaptic Vesicles at Excitatory Synapses

    Hana L. Goldschmidt

    2016-01-01

    Full Text Available Synaptic transmission relies on coordinated coupling of synaptic vesicle (SV exocytosis and endocytosis. While much attention has focused on characterizing proteins involved in SV recycling, the roles of membrane lipids and their metabolism remain poorly understood. Diacylglycerol, a major signaling lipid produced at synapses during synaptic transmission, is regulated by diacylglycerol kinase (DGK. Here, we report a role for DGKθ in the mammalian CNS in facilitating recycling of presynaptic vesicles at excitatory synapses. Using synaptophysin- and vGlut1-pHluorin optical reporters, we found that acute and chronic deletion of DGKθ attenuated the recovery of SVs following neuronal stimulation. Rescue of recycling kinetics required DGKθ kinase activity. Our data establish a role for DGK catalytic activity at the presynaptic nerve terminal in SV recycling. Altogether, these data suggest that DGKθ supports synaptic transmission during periods of elevated neuronal activity.

  19. Recycling, inventory and permeation of hydrogen isotopes and helium in the first wall of a thermonuclear fusion reactor

    The work was divided into three parts. The first part, which is theoretical, examines the behaviour of hydrogen in metals. After an introduction on the presence of hydrogen isotopes in fusion reactors, the main phenomena connected with hydrogen-metal interaction are summarised: solubility, diffusivity and trapping in material defects. The metal temperature is highlighted as the main parameter in the description of the phenomena. The second part of the work, also theoretical, concerns the interaction between helium and metals. We have tried as much as possible to show analogies and differences in the comparisons of the behaviour of hydrogen. The main types of damage caused by helium in metallic structures, which are the most important consequence of helium-metal interaction, were summarised. The characteristics of helium were treated in greater depth than those of hydrogen, because the latter are very well known. Also, there is a vast literature on the hydrogen-metal interaction. In the third and last part of the work a model was identified which allows the simulation of the evolution of a system formed from a metal in which hydrogen and helium isotopes have been introduced. A system of algebraic-differential equations was used to study the temporal evolution of the concentrations, the recycling, the inventory and the permeation of tritium and helium considering that these atoms diffuse in the metallic lattice and remain trapped in the vacancies created inside the metal by the bombardment of the neutrons from the fusion reactions. For the numerical simulation a series of data intended to represent the situation inside a thermonuclear reactor as precisely as possible were used for the numerical simulation. Analysis of the system was preceded by the analytical resolution of the steady state equations so that they could be compared with the simulation results

  20. Analysis of scavengers' activities and recycling in some cities of Nigeria.

    Agunwamba, J C

    2003-07-01

    The state of solid waste recycling by scavengers in Onitsha, a heavily commercial city in Anambra State, and some other urban areas such as Nsukka, Enugu, and Port Harcourt was analyzed. Data were obtained through interviews of scavengers who deal with recyclables. Although the activities of scavengers are sub-optimal, they can have a great impact on Nigerian economy with respect to resource conservation, creation of job opportunities, and reduction of the magnitude of waste disposal problems. A cost analysis is presented to compare the different forms of recycling utilized by municipal solid waste management. It is shown that a well-planned recycling program with recycling and composting would result in 18.6% savings in waste management costs and 57.7% in landfill avoidance costs. However, if the compost materials are not recycled, the corresponding savings in cost become 8.6% and 28.6%, respectively. The option with the lowest cost involves encouraging individual households to separate at the source their recyclables, which are bought by scavengers. This results in 78.0% savings in waste management cost and 79.5% landfill avoidance cost. A low-cost approach aimed at the integration of scavenging activities into conventional solid waste management is presented. PMID:14703917

  1. Heavy concrete shieldings made of recycled radio-active steel

    Maintenance and decommissioning of nuclear installations will generate increasing quantities of radioactively contaminated metallic residues. For many years, Siempelkamp has been melting low-level radioactive scrap in order to re-use it for containers of nuclear industry. Another new recycling path has recently been developed by producing steel granules from the melt. These granules are used as replacement for hematite (iron ore) in the production of heavy concrete shieldings. In the CARLA plant (central plant for the recycling of low-level radioactive waste) of Siempelkamp Nuklear- und Umwelttechnik GmbH and Co., the scrap is melted in a medium frequency induction furnace. The liquid iron is poured into a cooling basin through a water jet, which splits the iron into granules. The shape of these granules is determined by various factors, such as water jet speed, pouring rate of the liquid iron and different additives to the melt. In this process, massive spheres with diameters ranging from 1 to 8 mm can be produced which add to the density of heavy concrete elements for optimum shielding. In close cooperation with Boschert, which indeed is an expert for the production of concrete shieldings, a new technology for manufacturing heavy concrete shieldings, containing low-level radioactive steel granules, has been developed. The portion of steel granules in the concrete is approx. 50 weight-%. A concrete density between 2.4 kg/dm3 and 4.0 kg/dm3 is available. The compressive strength for the concrete reaches values up to 65 MPa. Different types of Granulate Shielding Casks (GSC) are offered by Siempelkamp. The most famous one is the GSC 200 for 200 1 drums, which has already been qualified for final storage of radioactive wastes at the German Morsleben final repository (ERAM). This newly developed recycling process further increases the quantities of low-level radioactive metallic wastes available for recycling. Expensive storage area can thus be saved respectively

  2. Activated aluminum hydride hydrogen storage compositions and uses thereof

    Sandrock, Gary; Reilly, James; Graetz, Jason; Wegrzyn, James E.

    2010-11-23

    In one aspect, the invention relates to activated aluminum hydride hydrogen storage compositions containing aluminum hydride in the presence of, or absence of, hydrogen desorption stimulants. The invention particularly relates to such compositions having one or more hydrogen desorption stimulants selected from metal hydrides and metal aluminum hydrides. In another aspect, the invention relates to methods for generating hydrogen from such hydrogen storage compositions.

  3. Activated magnesium for hydrogen energy storage

    Hydrogen is the ideal means of storage, transport and conversion of energy for a comprehensive clean-energy concept because of its free emission. Hydrogen can be stored as an energy carrier in the form of gas, liquid, and in solid. Magnesium is the candidate material for on-board hydrogen storage in the form of solid metal hydride because of its safe and higher volumetric energy density, about 7.6 wt% of the metal. Previous experiment on the hydriding of magnesium with the particle size of <0.3 mm and <60 μm yields very poor hydrogen capacity due to the oxygen existence on the metal surface. To improve the hydrogen sorption properties, the magnesium with the particle size of <60 μm is activated by treating the metal with 0.15M NH4F solution for 1 hour. The hydriding experiment is conducted in a hydriding system that can be operated at a very high vacuum up to 1x10-7 mbar. Analyses on the experimental results of two cycles of hydriding show that the activated magnesium powder with the particle size of <60 mm absorbed hydrogen in the amount of 3.82 wt% of the metal in the first cycle, which increased to 5.15 wt% in the second cycle. The absorption process took respectively 312 and 221 seconds for the first and second cycle of hydriding. Experimental results show that the hydrogen capacity of the current experiment is still low likely due to the particle size of magnesium metal, i.e. it should be nano size. (author)

  4. Heterolytic Activation of Hydrogen Promoted by Ruthenium Nanoparticles immobilized on Basic Supports and Hydrogenation of Aromatic Compounds

    Fang, Minfeng

    Despite the aggressive development and deployment of new renewable and nuclear technologies, petroleum-derived transportation fuels---gasoline, diesel and jet fuels---will continue to dominate the markets for decades. Environmental legislation imposes severe limits on the tolerable proportion of aromatics, sulfur and nitrogen contents in transportation fuels, which is difficult to achieve with current refining technologies. Catalytic hydrogenation plays an important role in the production of cleaner fuels, both as a direct means to reduce the aromatics and as a key step in the hydrodenitrogenation (HDN) and hydrodesulfurization (HDS) processes. However, conventional catalysts require drastic conditions and/or are easily poisoned by S or N aromatics. Therefore, there is still a need for new efficient catalysts for hydrogenation reactions relevant to the production of cleaner fossil fuels. Our catalyst design involves metallic nanoparticles intimately associated with a basic support, with the aim of creating a nanostructure capable of promoting the heterolytic activation of hydrogen and ionic hydrogenation mechanisms, as a strategy to avoid catalyst poisoning and enhance catalytic activity. We have designed and prepared a new nanostructured catalytic material composed of RuNPs immobilized on the basic polymer P4VPy. We have demonstrated that the Ru/P4VPy catalyst can promote heterolytic hydrogen activation and a unique surface ionic hydrogenation mechanism for the efficient hydrogenation of N-aromatics. This is the first time these ionic hydrogenation pathways have been demonstrated on solid surfaces. For the RuNPs surfaces without basic sites in close proximity, the conventional homolytic H2 splitting is otherwise involved. Using the mechanistic concepts from Ru/P4VPy, we have designed and prepared the Ru/MgO catalyst, with the aim to improve the catalytic efficiency for the hydrogenation of heteroatom aromatics operating by the ionic hydrogenation mechanism. The Ru

  5. Methanol synthesis from recycled carbon dioxide and hydrogen from high temperature steam electrolysis with the nuclear heat of an HTGR

    Global warming resulting from increasing carbon dioxide is a crucial and imperative issue to cope with. Curving CO2 emission is a must to prevent global warming. This paper addresses a study of an environment-friendly plant concept in which reduction of emissions is attained by utilizing nuclear generated heat to methanol production. The process of the plant is as follows: (1) High-temperature heat energy is obtained from MHTGRs (MHTGR: Modular High-Temperature Gas-Cooled Reactor) that emit no CO2. (2) The high-temperature heat electrolyzes steam into hydrogen. (3) Hydrogen reacts with carbon dioxide emitted from a thermal power plant producing methanol: a promising and easily transportable. This paper describes the results studied by Sub-Group ''Methanol Synthesis from Recycled Carbon Dioxide and Hydrogen from High Temperature Steam Electrolysis'' which branches out of ''Study Group'' belonging to ''The Committee on Uses of Reactor Heat'' organized by Japan Industrial Forum (JAIF). (author). 5 refs, 7 figs, 1 tab

  6. Recyclability of water-soluble ruthenium–phosphine complex catalysts in multiphase selective hydrogenation of cinnamaldehyde using toluene and pressurized carbon dioxide

    Fujita, Shin-ichiro; Akihara, Shuji; Arai, Masahiko

    2006-01-01

    The recyclability of water-soluble ruthenium–phosphine complex catalysts was investigated in water–toluene and in water–pressurized carbon dioxide systems for selective hydrogenation of trans-cinnamaldehyde (CAL). For the first hydrogenation run, the selectivity for cinnamyl alcohol (COL) is high for both toluene and dense CO2, because of interfacial catalysis in which the reaction mainly occurs at the interface between the aqueous phase and the other toluene or dense CO2 phase. The total CAL...

  7. A zero-waste option: recycling and clearance of activated vanadium alloys

    The reduction of long-term radioactivity is analysed here in V-Cr-Ti alloys, one of the proposed structural materials for fusion power plants. In particular is explored the possibility of recycling within the nuclear industry and of clearance, that is declassification to non-active material. Vanadium alloys have the potential to reach the dose rate hands-on recycling limit when used in a blanket, if noxious radioactive products coming from impurities activation are eliminated. Clearance is also possible in principle, but only if further separation of activation products of titanium is carried out after service

  8. A zero-waste option: Recycling and clearance of activated vanadium alloys

    The reduction of long-term radioactivity is analysed here in V-Cr-Ti alloys, one of the proposed structural materials for fusion power reactors. In particular, it is explored the possibility of recycling within the nuclear industry or clearance, that is declassification to non-active material. Vanadium alloys have the potential to reach the dose rate hands-on recycling limit when used in a blanket, if noxious radioactive products coming from impurities activation are eliminated. Clearance is possible in principle too, however only if a further separation of activation products of titanium is done after service. (author)

  9. Transport of carbon ion test particles and hydrogen recycling in the plasma of the Columbia tokamak ''HBT'' [High Beta Tokamak

    Carbon impurity ion transport is studied in the Columbia High Beta Tokamak (HBT), using a carbon tipped probe which is inserted into the plasma (ne ∼ 1 - 5 x 1014 (cm-3), Te ∼ 4 - 10 (eV), Bt ∼ 0.2 - 0.4(T)). Carbon impurity light, mainly the strong lines of CII(4267A, emitted by the C+ ions) and CIII (4647A, emitted by the C++ ions), is formed by the ablation or sputtering of plasma ions and by the discharge of the carbon probe itself. The diffusion transport of the carbon ions is modeled by measuring the space-and-time dependent spectral light emission of the carbon ions with a collimated optical beam and photomultiplier. The point of emission can be observed in such a way as to sample regions along and transverse to the toroidal magnetic field. The carbon ion diffusion coefficients are obtained by fitting the data to a diffusion transport model. It is found that the diffusion of the carbon ions is ''classical'' and is controlled by the high collisionality of the HBT plasma; the diffusion is a two-dimensional problem and the expected dependence on the charge of the impurity ion is observed. The measurement of the spatial distribution of the Hα emissivity was obtained by inverting the light signals from a 4-channel polychromator, the data were used to calculate the minor-radial influx, the density, and the recycling time of neutral hydrogen atoms or molecules. The calculation shows that the particle recycling time τp is comparable with the plasma energy confinement time τE; therefore, the recycling of the hot plasma ions with the cold neutrals from the walls is one of the main mechanisms for loss of plasma energy

  10. Visible light active photocatalyst from recycled disposable heating pads

    Lee, Meng-Chien; Wang, Chun-Yu; Chen, Che-Chin; Wang, Chih-Ming; Hsiao, Ta-Chih; Tsai, Din Ping

    2016-01-01

    Alpha-Fe2O3 (α-Fe2O3) is cheap and abundant and has potential to be a highly efficient photocatalyst for water splitting. According to the report, there are a huge amount of disposable heating pads being created every year, and the pads are used one time then thrown away. We found that the main product of used heating pads is α-Fe2O3. Here, we collect and purify the α-Fe2O3 powder in the used heating pads using low power consumption processes. It is shown that the recycled heating pads can be used as a cost-effective photocatalyst for H2 energy and for decomposition of organic pollutants as well. Additionally, the plasmonic enhanced photocatalysis reaction of α-Fe2O3 is also investigated. It is found that H2 evolution rate can be enhanced 15% using α-Fe2O3 nanoparticles coated with a thin Au layer. The degradation of methylene blue can also enhance 12% compared to photocatalyst α-Fe2O3 nanoparticles coated without Au layer.

  11. Hydrogen activation by [NiFe]-hydrogenases.

    Carr, Stephen B; Evans, Rhiannon M; Brooke, Emily J; Wehlin, Sara A M; Nomerotskaia, Elena; Sargent, Frank; Armstrong, Fraser A; Phillips, Simon E V

    2016-06-15

    Hydrogenase-1 (Hyd-1) from Escherichia coli is a membrane-bound enzyme that catalyses the reversible oxidation of molecular H2 The active site contains one Fe and one Ni atom and several conserved amino acids including an arginine (Arg(509)), which interacts with two conserved aspartate residues (Asp(118) and Asp(574)) forming an outer shell canopy over the metals. There is also a highly conserved glutamate (Glu(28)) positioned on the opposite side of the active site to the canopy. The mechanism of hydrogen activation has been dissected by site-directed mutagenesis to identify the catalytic base responsible for splitting molecular hydrogen and possible proton transfer pathways to/from the active site. Previous reported attempts to mutate residues in the canopy were unsuccessful, leading to an assumption of a purely structural role. Recent discoveries, however, suggest a catalytic requirement, for example replacing the arginine with lysine (R509K) leaves the structure virtually unchanged, but catalytic activity falls by more than 100-fold. Variants containing amino acid substitutions at either or both, aspartates retain significant activity. We now propose a new mechanism: heterolytic H2 cleavage is via a mechanism akin to that of a frustrated Lewis pair (FLP), where H2 is polarized by simultaneous binding to the metal(s) (the acid) and a nitrogen from Arg(509) (the base). PMID:27284053

  12. The feasibility of recycling and clearance of active materials from fusion power plants

    Zucchetti, M. [EURATOM/ENEA Fusion Association, Politecnico di Torino (Italy)]. E-mail: massimo.zucchetti@polito.it; El-Guebaly, L.A. [University of Wisconsin-Madison, Madison, WI (United States); Forrest, R.A. [EURATOM/UKAEA Fusion Association, Culham Science Centre, Abingdon (United Kingdom); Marshall, T.D. [Idaho National Laboratory, Idaho Falls (United States); Taylor, N.P. [EURATOM/UKAEA Fusion Association, Culham Science Centre, Abingdon (United Kingdom); Tobita, K. [Japan Atomic Energy Agency, Ibaraki (Japan)

    2007-08-01

    In order to minimize the quantity of active materials that require long-term storage, arising during operation and after fusion power plant decommissioning, maximum use should be made of both recycling within the nuclear industry and clearance. For the latter, revised limits have been recently issued at the international level and in the US and Europe. In this paper the implications for fusion materials of these new levels are considered. Concerning recycling, power plant studies have employed criteria based solely on radiological parameters. Reviews of remote procedures currently used within the nuclear industry suggest that these criteria have been unduly conservative and should be revised.

  13. A recyclable and highly active Co3O4 nanoparticles/titanate nanowire catalyst for organic dyes degradation with peroxymonosulfate

    Sodium ions of TNWs were exchanged with hydrogen ions, and this protocol was very suitable for capturing high density of cobalt ions. Meanwhile, the fabricated Co3O4/TNWs nano-material presented a highly catalytic and stable activity for dye degradation. - Highlights: • Co3O4 nanoparticles were deposited on the pretreated TNWs surface. • The TNWs treated by hydrogen ions captures higher density of cobalt ions. • The Co3O4/TNWs catalyst possesses highly efficiency for dyes degradation with oxone. - Abstract: In this paper, we reported a recyclable and highly active porous catalyst of titanate nanowires (TNWs) coated with well-distributed Co3O4 nanoparticles (NPs) (Co3O4/TNWs). Sodium ions of TNWs were exchanged with hydrogen ions in the dilute nitric acid, and this protocol was very suitable for capturing cobalt ions. X-ray diffraction (XRD) demonstrated the existence of Co3O4 phase with unique lattice planes, such as (2 2 0), (3 1 1) and (5 1 1). Electron microscopes (FE-SEM and TEM) indicated that the Co3O4 NPs with an average diameter of 22 ± 3 nm were coated uniformly on TNWs surface (average diameter: 37 ± 5.5 nm), and the Co3O4 NPs mainly exposed their (2 2 0) and (2 2 2) active planes. XPS analysis confirms the formation of Co3O4 phase by the presence of Co 2p peaks at 780.1 eV (2p 3/2) and 795.5 eV (2p 1/2). Methylene blue (MB) and other organic dyes (rhodamine B (RhB) and methyl orange (MO)) were chosen as target compounds for catalytic degradation under indoor scattering light. Compared to the original Co3O4/TNWs catalyst, the catalytic efficiency of nanoscaled catalyst with oxone for MB was about 15 times higher, and the MB solution (10 mg L−1) was completely degraded within 8 min. The catalytic activity of recycled catalyst used in the sixth run still remained very active, and the degradation time for MB was only 16 min. The nanosized catalyst also had a high activity for dyes of RhB (10 mg L−1) and MO (10 mg L−1), as the degradation

  14. Hydraulic characterization of an activated sludge reactor with recycling system by tracer experiment and analytical models.

    Sánchez, F; Viedma, A; Kaiser, A S

    2016-09-15

    Fluid dynamic behaviour plays an important role in wastewater treatment. An efficient treatment requires the inexistence of certain hydraulic problems such as dead zones or short-circuiting flows. Residence time distribution (RTD) analysis is an excellent technique for detecting these inefficiencies. However, many wastewater treatment installations include water or sludge recycling systems, which prevent us from carrying out a conventional tracer pulse experiment to obtain the RTD curve of the installation. This paper develops an RTD analysis of an activated sludge reactor with recycling system. A tracer experiment in the reactor is carried out. Three analytical models, derived from the conventional pulse model, are proposed to obtain the RTD curve of the reactor. An analysis of the results is made, studying which model is the most suitable for each situation. This paper is useful to analyse the hydraulic efficiency of reactors with recycling systems. PMID:27288672

  15. Estimating the amount of Ship Recycling Activity Using Remote Sensing Application

    Watagawa, M.; Shinoda, T.; Hasegawa, K.

    2016-06-01

    The Advanced Land Observing Satellite (ALOS) was launched for earth observation and there are more than 6 million scenes of archives including coastal areas during period of five years. The wealth of satellite imagery is noticeable for investigating monitoring methods such as ship detection in wide ocean area. Especially, it is useful way to estimate past behaviour from satellite imagery compared to reference data. We collected satellite imagery and analysis breaking process in major ship breaking yards between year 2009 and 2011. Comparing the number of recycling ships by satellite imagery to the world statistics is in good agreement. In this study, Remote Sensing Application has been discussed in order to assess the potential to be used for economic activities such as ship recycling in wide coastal area. It was used to evaluate the performance of ship recycling monitoring by Satellite imagery. Additionally, an approach for recognizing ships by SAR imagery regardless of weather conditions is presented.

  16. Hydrogen recycling. A way to improve the efficiency of HPH {sup registered} -bell-type annealing furnaces; Wasserstoffrecycling. Eine Massnahme zur Steigerung der Effizienz von HPH {sup registered} -Haubengluehanlagen

    Wendt, Peter [LOI Thermprocess GmbH, Essen (Germany). Geschaeftsbereich HPH(registered) - Haubengluehanlagen und Bandbehandlungsanlagen; Dengel, Udo [H2 Gen Innovations Inc. (United States)

    2009-03-15

    While hydrogen is used around the world as a protective gas in modern bell annealing furnaces, hydrogen costs represent a significant proportion of operating costs. The article describes a method for recycling hydrogen in bell annealing applications that significantly reduces operating costs. The integration of the hydrogen recycling system with the bell annealing furnaces is presented and operating cost and environmental benefits are assessed. The system can be retrofitted to existing bell annealing installations and has potential for other applications where hydrogen is used. (orig.)

  17. Plutonium recycle test reactor characterization activities and results

    Report contains results of PRTR core and associated structures characterization performed in January and February of 1997. Radiation survey data are presented, along with recommendations for stabilization activities before transitioning to a decontamination and decommissioning function. Recommendations are also made about handling the waste generated by the stabilization activities, and actions suggested by the Decontamination and Decommissioning organization

  18. Hanford Low-Activity Waste Processing: Demonstration of the Off-Gas Recycle Flowsheet - 13443

    Vitrification of Hanford Low-Activity Waste (LAW) is nominally the thermal conversion and incorporation of sodium salts and radionuclides into borosilicate glass. One key radionuclide present in LAW is technetium-99. Technetium-99 is a low energy, long-lived beta emitting radionuclide present in the waste feed in concentrations on the order of 1-10 ppm. The long half-life combined with a high solubility in groundwater results in technetium-99 having considerable impact on performance modeling (as potential release to the environment) of both the waste glass and associated secondary waste products. The current Hanford Tank Waste Treatment and Immobilization Plant (WTP) process flowsheet calls for the recycle of vitrification process off-gas condensates to maximize the portion of technetium ultimately immobilized in the waste glass. This is required as technetium acts as a semi-volatile specie, i.e. considerable loss of the radionuclide to the process off-gas stream can occur during the vitrification process. To test the process flowsheet assumptions, a prototypic off-gas system with recycle capability was added to a laboratory melter (on the order of 1/200 scale) and testing performed. Key test goals included determination of the process mass balance for technetium, a non-radioactive surrogate (rhenium), and other soluble species (sulfate, halides, etc.) which are concentrated by recycling off-gas condensates. The studies performed are the initial demonstrations of process recycle for this type of liquid-fed melter system. This paper describes the process recycle system, the waste feeds processed, and experimental results. Comparisons between data gathered using process recycle and previous single pass melter testing as well as mathematical modeling simulations are also provided. (authors)

  19. Hanford Low-Activity Waste Processing: Demonstration of the Off-Gas Recycle Flowsheet - 13443

    Ramsey, William G.; Esparza, Brian P. [Washington River Protection Solutions, LLC, Richland, WA 99532 (United States)

    2013-07-01

    Vitrification of Hanford Low-Activity Waste (LAW) is nominally the thermal conversion and incorporation of sodium salts and radionuclides into borosilicate glass. One key radionuclide present in LAW is technetium-99. Technetium-99 is a low energy, long-lived beta emitting radionuclide present in the waste feed in concentrations on the order of 1-10 ppm. The long half-life combined with a high solubility in groundwater results in technetium-99 having considerable impact on performance modeling (as potential release to the environment) of both the waste glass and associated secondary waste products. The current Hanford Tank Waste Treatment and Immobilization Plant (WTP) process flowsheet calls for the recycle of vitrification process off-gas condensates to maximize the portion of technetium ultimately immobilized in the waste glass. This is required as technetium acts as a semi-volatile specie, i.e. considerable loss of the radionuclide to the process off-gas stream can occur during the vitrification process. To test the process flowsheet assumptions, a prototypic off-gas system with recycle capability was added to a laboratory melter (on the order of 1/200 scale) and testing performed. Key test goals included determination of the process mass balance for technetium, a non-radioactive surrogate (rhenium), and other soluble species (sulfate, halides, etc.) which are concentrated by recycling off-gas condensates. The studies performed are the initial demonstrations of process recycle for this type of liquid-fed melter system. This paper describes the process recycle system, the waste feeds processed, and experimental results. Comparisons between data gathered using process recycle and previous single pass melter testing as well as mathematical modeling simulations are also provided. (authors)

  20. Fission product recycling as catalysts for hydrogen production by water electrolysis

    An electrolytic extraction method has been studied to separate fission products (Ru, Rh, Pd, Tc, Se, Te, etc) from the nuclear spent fuel. Yet they are rare metal fission products (RMFP), most are long-lived (LLFP; Pd, Tc, Se, Te). In the applied separation process, Pd2+ cation itself would not only be easily deposited from various nitric acid solutions, but enhance also the deposition of RuNO3+ and ReO4- by acting as a catalyst (as Pdadatom). Such Catalytic Electrolytic Extraction (CEE) method was found to be applicable in the case of TcO4- deposition, too. The quaternary-, Pd-Ru-Rh-Re, deposit on the Pt electrodes show the highest cathodic current, ca twice superior to that of the Pt electrode both in artificial sea water as well as in alkaline solution. The promising utilization of RMFP will be as 'FP-catalyst' for hydrogen production by water electrolysis. RMFP would be circulating material to bridge nuclear and hydrogen energy systems. (author)

  1. Direct hydrogenation and one-pot reductive amidation of nitro compounds over Pd/ZnO nanoparticles as a recyclable and heterogeneous catalyst

    Graphical abstract: - Highlights: • Palladium supported on zinc oxide. • Nano crystalline Pd/ZnO as highly efficient heterogeneous catalyst. • Synthesis, chracterization, and application of nano-Pd/ZnO. • Ligand-free and air atmosphere conditions. - Abstract: A novel Pd supported on ZnO nanoparticles was readily synthesized and characterized. The amount of palladium on ZnO is 9.84 wt% which was determined by ICP analysis and atomic absorption spectroscopy (AAS). Percentage of accessible Pd as active catalyst is also estimated to 2.72% based on the thermogravimetric (TG) analysis. This nano-sized Pd/ZnO with an average particle size of 20–25 nm and specific surface area 40.61 m2 g−1 was used as a new reusable heterogeneous catalyst for direct hydrogenation and one-pot reductive amidation of nitro compounds without the use of any ligands under atmospheric pressure. The catalyst can be recovered and recycled several times without marked loss of activity

  2. Direct hydrogenation and one-pot reductive amidation of nitro compounds over Pd/ZnO nanoparticles as a recyclable and heterogeneous catalyst

    Hosseini-Sarvari, Mona, E-mail: hossaini@shirazu.ac.ir; Razmi, Zahra

    2015-01-01

    Graphical abstract: - Highlights: • Palladium supported on zinc oxide. • Nano crystalline Pd/ZnO as highly efficient heterogeneous catalyst. • Synthesis, chracterization, and application of nano-Pd/ZnO. • Ligand-free and air atmosphere conditions. - Abstract: A novel Pd supported on ZnO nanoparticles was readily synthesized and characterized. The amount of palladium on ZnO is 9.84 wt% which was determined by ICP analysis and atomic absorption spectroscopy (AAS). Percentage of accessible Pd as active catalyst is also estimated to 2.72% based on the thermogravimetric (TG) analysis. This nano-sized Pd/ZnO with an average particle size of 20–25 nm and specific surface area 40.61 m{sup 2} g{sup −1} was used as a new reusable heterogeneous catalyst for direct hydrogenation and one-pot reductive amidation of nitro compounds without the use of any ligands under atmospheric pressure. The catalyst can be recovered and recycled several times without marked loss of activity.

  3. Unassisted photoelectrochemical water splitting exceeding 7% solar-to-hydrogen conversion efficiency using photon recycling

    Shi, Xinjian; Jeong, Hokyeong; Oh, Seung Jae; Ma, Ming; Zhang, Kan; Kwon, Jeong; Choi, In Taek; Choi, Il Yong; Kim, Hwan Kyu; Kim, Jong Kyu; Park, Jong Hyeok

    2016-06-01

    Various tandem cell configurations have been reported for highly efficient and spontaneous hydrogen production from photoelectrochemical solar water splitting. However, there is a contradiction between two main requirements of a front photoelectrode in a tandem cell configuration, namely, high transparency and high photocurrent density. Here we demonstrate a simple yet highly effective method to overcome this contradiction by incorporating a hybrid conductive distributed Bragg reflector on the back side of the transparent conducting substrate for the front photoelectrochemical electrode, which functions as both an optical filter and a conductive counter-electrode of the rear dye-sensitized solar cell. The hybrid conductive distributed Bragg reflectors were designed to be transparent to the long-wavelength part of the incident solar spectrum (λ>500 nm) for the rear solar cell, while reflecting the short-wavelength photons (λ<500 nm) which can then be absorbed by the front photoelectrochemical electrode for enhanced photocurrent generation.

  4. Strategic recycling of fission products in nuclear fuel cycle as for hydrogen production catalyst

    The catalytic electrolytic extraction (CEE) method has been studied as a separation tool for rare metal fission products [RMFP - Ru, Rh, Pd*, Tc*, Se* and Te* (*LLFP)] in spent nuclear fuel. In an employed CEE process, Pd2+ cation itself would not only be easily deposited from various nitric acid solutions, but would also enhance the deposition of co-existing RuNO3+, ReO-4 and 99TcO-4 by acting as a catalyst (as Pdadatom). The quaternary, Pd-Ru-Rh-Re, deposit Pt or Ti electrode, fabricated by CEE, suggested the highest cathodic current corresponding to the hydrogen generation reaction in both alkaline solution and seawater. The advanced ORIENT cycle, where ion exchange chromatography using tertiary pyridine resin and the CEE is employed as a mainstay separation technology, will enhance separation and utilisation of actinide and fission products, and thus be expected to realize an ultimate reduction of radioactive wastes. (authors)

  5. Unassisted photoelectrochemical water splitting exceeding 7% solar-to-hydrogen conversion efficiency using photon recycling.

    Shi, Xinjian; Jeong, Hokyeong; Oh, Seung Jae; Ma, Ming; Zhang, Kan; Kwon, Jeong; Choi, In Taek; Choi, Il Yong; Kim, Hwan Kyu; Kim, Jong Kyu; Park, Jong Hyeok

    2016-01-01

    Various tandem cell configurations have been reported for highly efficient and spontaneous hydrogen production from photoelectrochemical solar water splitting. However, there is a contradiction between two main requirements of a front photoelectrode in a tandem cell configuration, namely, high transparency and high photocurrent density. Here we demonstrate a simple yet highly effective method to overcome this contradiction by incorporating a hybrid conductive distributed Bragg reflector on the back side of the transparent conducting substrate for the front photoelectrochemical electrode, which functions as both an optical filter and a conductive counter-electrode of the rear dye-sensitized solar cell. The hybrid conductive distributed Bragg reflectors were designed to be transparent to the long-wavelength part of the incident solar spectrum (λ>500 nm) for the rear solar cell, while reflecting the short-wavelength photons (λ<500 nm) which can then be absorbed by the front photoelectrochemical electrode for enhanced photocurrent generation. PMID:27324578

  6. High-energy, stable and recycled molecular solar thermal storage materials using AZO/graphene hybrids by optimizing hydrogen bonds.

    Luo, Wen; Feng, Yiyu; Qin, Chengqun; Li, Man; Li, Shipei; Cao, Chen; Long, Peng; Liu, Enzuo; Hu, Wenping; Yoshino, Katsumi; Feng, Wei

    2015-10-21

    An important method for establishing a high-energy, stable and recycled molecular solar heat system is by designing and preparing novel photo-isomerizable molecules with a high enthalpy and a long thermal life by controlling molecular interactions. A meta- and ortho-bis-substituted azobenzene chromophore (AZO) is covalently grafted onto reduced graphene oxide (RGO) for solar thermal storage materials. High grafting degree and close-packed molecules enable intermolecular hydrogen bonds (H-bonds) for both trans-(E) and cis-(Z) isomers of AZO on the surface of nanosheets, resulting in a dramatic increase in enthalpy and lifetime. The metastable Z-form of AZO on RGO is thermally stabilized with a half-life of 52 days by steric hindrance and intermolecular H-bonds calculated using density functional theory (DFT). The AZO-RGO fuel shows a high storage capacity of 138 Wh kg(-1) by optimizing intermolecular H-bonds with a good cycling stability for 50 cycles induced by visible light at 520 nm. Our work opens up a new method for making advanced molecular solar thermal storage materials by tuning molecular interactions on a nano-template. PMID:26289389

  7. Neutron activation analysis of recycled paper and board in contact with food

    Recycling of wastepaper has been shown to increase the concentration of metals in the product. Although it is generally assumed that there is no risk of migration of chemical contaminants from recycled paper and board into food, the UK Food Standards Agency has identified limited evidence of such migration. Therefore, it is important to carry out research to establish the concentration of metals in recycled paper and board in contact with food. A previous study at Imperial College had resulted in the development of a neutron activation analysis method to determine trace metals in plastic packaging. An initial study is described to establish whether the same methodology could be applied to paper and board and to carry out a preliminary investigation into a small range of recycled paper and board products. The study was made on 22 elements in 17 products including pizza boxes, fries boxes, kitchen towel, table napkins, greaseproof paper, tea bags and cake cases. Elevated levels of some elements including barium (69 mg/kg in pizza bases) and chromium (5 mg/kg in napkins, 50 mg/kg in greaseproof paper, 2 mg/kg in cake cases, 90 mg/kg in baking parchment, 5 mg/kg in fries boxes and 5 mg/kg in pizza bases) have been shown. (author)

  8. NAD(H recycling activity of an engineered bifunctional enzyme galactose dehydrogenase/lactate dehydrogenase

    2006-03-01

    Full Text Available A chimeric bifunctional enzyme composing of galactose dehydrogenase (galDH; from Pseudomonas fluorescens and lactate dehydrogenase (LDH; from Bacillus stearothermophilus was successfully constructed. The chimeric galDH/LDH possessed dual characteristics of both galactose dehydrogenase and lactate dehydrogenase activities while exhibiting hexameric rearrangement with a molecular weight of approximately 400 kDa. In vitro observations showed that the chimeric enzyme was able to recycle NAD with a continuous production of lactate without any externally added NADH. Two fold higher recycling rate (0.3 mM/h than that of the native enzyme was observed at pH values above 8.5. Proximity effects became especially pronounced during the recycling assay when diffusion hindrance was induced by polyethylene glycol. All these findings open up a high feasibility to apply the NAD(H recycling system for metabolic engineering purposes e.g. as a model to gain a better understanding on the molecular proximity process and as the routes for synthesizing of numerous high-value-added compounds.

  9. Innovative Strategy on Hydrogen Evolution Reaction Utilizing Activated Liquid Water

    Bing-Joe Hwang; Hsiao-Chien Chen; Fu-Der Mai; Hui-Yen Tsai; Chih-Ping Yang; John Rick; Yu-Chuan Liu

    2015-01-01

    Splitting water for hydrogen production using light, or electrical energy, is the most developed ‘green technique’. For increasing efficiency in hydrogen production, currently, the most exciting and thriving strategies are focused on efficient and inexpensive catalysts. Here, we report an innovative idea for efficient hydrogen evolution reaction (HER) utilizing plasmon-activated liquid water with reduced hydrogen-bonded structure by hot electron transfer. This strategy is effective for all HE...

  10. An Approach for Hydrogen Recycling in a Closed-loop Life Support Architecture to Increase Oxygen Recovery Beyond State-of-the-Art

    Abney, Morgan B.; Miller, Lee; Greenwood, Zachary; Alvarez, Giraldo

    2014-01-01

    State-of-the-art atmosphere revitalization life support technology on the International Space Station is theoretically capable of recovering 50% of the oxygen from metabolic carbon dioxide via the Carbon Dioxide Reduction Assembly (CRA). When coupled with a Plasma Pyrolysis Assembly (PPA), oxygen recovery increases dramatically, thus drastically reducing the logistical challenges associated with oxygen resupply. The PPA decomposes methane to predominantly form hydrogen and acetylene. Because of the unstable nature of acetylene, a down-stream separation system is required to remove acetylene from the hydrogen stream before it is recycled to the CRA. A new closed-loop architecture that includes a PPA and downstream Hydrogen Purification Assembly (HyPA) is proposed and discussed. Additionally, initial results of separation material testing are reported.

  11. Visible-Light Active and Magnetically Recyclable Nanocomposites for the Degradation of Organic Dye

    Helin Niu; Qinmin Wang; Hongxia Liang; Min Chen; Changjie Mao; Jiming Song; Shengyi Zhang; Yuanhao Gao; Changle Chen

    2014-01-01

    Recyclable visible-light photocatalyst Fe3O4@TiO2 with core-shell structure was prepared by a simple synthetic strategy using solvothermal crystallization of titanium precursor on preformed Fe3O4 nanopartiles. The photo-degradation reaction of neutral red aqueous solution was tested to evaluate the visible-light photocatalytic activity of the as prepared Fe3O4@TiO2 nanoparticles, which show excellent photocatalytic activity compared with commercial P25 catalyst. Moreover, the Fe3O4@TiO2 nan...

  12. Waste Treatment Technology Process Development Plan For Hanford Waste Treatment Plant Low Activity Waste Recycle

    The purpose of this Process Development Plan is to summarize the objectives and plans for the technology development activities for an alternative path for disposition of the recycle stream that will be generated in the Hanford Waste Treatment Plant Low Activity Waste (LAW) vitrification facility (LAW Recycle). This plan covers the first phase of the development activities. The baseline plan for disposition of this stream is to recycle it to the WTP Pretreatment Facility, where it will be concentrated by evaporation and returned to the LAW vitrification facility. Because this stream contains components that are volatile at melter temperatures and are also problematic for the glass waste form, they accumulate in the Recycle stream, exacerbating their impact on the number of LAW glass containers. Approximately 32% of the sodium in Supplemental LAW comes from glass formers used to make the extra glass to dilute the halides to acceptable concentrations in the LAW glass, and reducing the halides in the Recycle is a key component of this work. Additionally, under possible scenarios where the LAW vitrification facility commences operation prior to the WTP Pretreatment facility, this stream does not have a proven disposition path, and resolving this gap becomes vitally important. This task seeks to examine the impact of potential future disposition of this stream in the Hanford tank farms, and to develop a process that will remove radionuclides from this stream and allow its diversion to another disposition path, greatly decreasing the LAW vitrification mission duration and quantity of glass waste. The origin of this LAW Recycle stream will be from the Submerged Bed Scrubber (SBS) and the Wet Electrostatic Precipitator (WESP) from the LAW melter off-gas system. The stream is expected to be a dilute salt solution with near neutral pH, and will likely contain some insoluble solids from melter carryover or precipitates of scrubbed components (e.g. carbonates). The soluble

  13. Hydrogen storage capacity of lithium-doped KOH activated carbons

    Highlights: • The hydrogen adsorption of lithium-doped KOH activated carbons has been studied. • Lithium doping improves their hydrogen adsorption affinity. • Lithium doping is more effective for materials with micropores of 0.8 nm or smaller. • Lithium reagent can alter the pore structure, depending on the raw material. • Optimizing the pore size and functional group is needed for better hydrogen uptake. - Abstract: The authors have studied the hydrogen adsorption performance of several types of lithium-doped KOH activated carbons. In the case of activated cokes, lithium doping improves their hydrogen adsorption affinity from 5.02 kg/m3 to 5.86 kg/m3 at 303 K. Hydrogen adsorption density increases by around 17% after lithium doping, likely due to the fact that lithium doping is more effective for materials with micropores of 0.8 nm or smaller. The effects of lithium on hydrogen storage capacity vary depending on the raw material, because the lithium reagent can react with the material and alter the pore structure, indicating that lithium doping has the effect of plugging or filling the micropores and changing the structures of functional groups, resulting in the formation of mesopores. Despite an observed decrease in hydrogen uptake, lithium doping was found to improve hydrogen adsorption affinity. Lithium doping increases hydrogen uptake by optimizing the pore size and functional group composition

  14. Recycle Used Oil on America Recycles Day.

    White, Boyd W.

    2000-01-01

    Explains that motor oils can be reused and recycled. Educates students about environmental hazards and oil management and includes classroom activities. Addresses the National Science Education Standards. (YDS)

  15. Modelling Recycling Targets

    Hill, Amanda Louise; Leinikka Dall, Ole; Andersen, Frits M.

    2014-01-01

    Within the European Union (EU) a paradigm shift is currently occurring in the waste sector, where EU waste directives and national waste strategies are placing emphasis on resource efficiency and recycling targets. The most recent Danish resource strategy calculates a national recycling rate of 22......% for household waste, and sets an ambitious goal of a 50% recycling rate by 2020. This study integrates the recycling target into the FRIDA model to project how much waste and from which streams should be diverted from incineration to recycling in order to achieve the target. Furthermore, it discusses...... how the existing technological, organizational and legislative frameworks may affect recycling activities. The results of the analysis show that with current best practice recycling rates, the 50% recycling rate cannot be reached without recycling of household biowaste. It also shows that all Danish...

  16. Overview of the International R&D Recycling Activities of the Nuclear Fuel Cycle

    Patricia Paviet-Hartmann

    2012-10-01

    Nuclear power has demonstrated over the last 30 years its capacity to produce base-load electricity at a low, predictable and stable cost due to the very low economic dependence on the price of uranium. However the management of used nuclear fuel remains the “Achilles’ Heel” of this energy source since the storage of used nuclear fuel is increasing as evidenced by the following number with 2,000 tons of UNF produced each year by the 104 US nuclear reactor units which equates to a total of 62,000 spent fuel assemblies stored in dry cask and 88,000 stored in pools. Two options adopted by several countries will be presented. The first one adopted by Europe, Japan and Russia consists of recycling the used nuclear fuel after irradiation in a nuclear reactor. Ninety six percent of uranium and plutonium contained in the spent fuel could be reused to produce electricity and are worth recycling. The separation of uranium and plutonium from the wastes is realized through the industrial PUREX process so that they can be recycled for re-use in a nuclear reactor as a mixed oxide (MOX) fuel. The second option undertaken by Finland, Sweden and the United States implies the direct disposal of used nuclear fuel into a geologic formation. One has to remind that only 30% of the worldwide used nuclear fuel are currently recycled, the larger part being stored (90% in pool) waiting for scientific or political decisions. A third option is emerging with a closed fuel cycle which will improve the global sustainability of nuclear energy. This option will not only decrease the volume amount of nuclear waste but also the long-term radiotoxicity of the final waste, as well as improving the long-term safety and the heat-loading of the final repository. At the present time, numerous countries are focusing on the R&D recycling activities of the ultimate waste composed of fission products and minor actinides (americium and curium). Several new chemical extraction processes, such as TRUSPEAK

  17. Overview of the international R and D recycling activities of the nuclear fuel cycle

    Nuclear power has demonstrated over the last thirty years its capacity to produce base-load electricity at a low, predictable and stable cost due to the very low economic dependence of the price of uranium. However the management of used nuclear fuel (UNF) remains the “Achilles’ heel of this energy source since the storage of UNF is increasing as evidenced by the following number with 2,000 to 2,300 of UNF produced each year by the 104 US nuclear reactor units which equates to a total of 62,000 UNF assemblies stored in dry cask storage and 88,000 stored in pools. Alarmingly, more than half of US commercial reactor sites have filled their pools to capacity and have had to add dry cask storage facilities. Two options adopted by several countries will be discussed. The first one adopted by Europe, Japan and Russia consists of recycling the used nuclear fuel after irradiation in a nuclear reactor. Ninety six percent of uranium and plutonium contained in the spent fuel could be reused to produce electricity and are worth recycling. The separation of uranium and plutonium from the wastes is realized through the industrial PUREX process so that they can be recycled for re-use in a nuclear reactor as a mixed oxide (MOX) fuel. The second option undertaken by Finland, Sweden and the United States implies the direct disposal of UNF into a geologic formation. One has to remind that only 30% of the worldwide UNF are currently recycled, the larger part being stored (90% in pool) waiting for scientific or political decisions. A third option is emerging with a closed fuel cycle which will improve the global sustainability of nuclear energy. This option will not only decrease the volume amount of nuclear waste but also the long-term radiotoxicity of the final waste, as well as improving the long-term safety and the heat-loading of the final repository. At the present time, numerous countries are focusing on the R and D recycling activities of the ultimate waste composed of

  18. Visible-Light Active and Magnetically Recyclable Nanocomposites for the Degradation of Organic Dye

    Helin Niu

    2014-05-01

    Full Text Available Recyclable visible-light photocatalyst Fe3O4@TiO2 with core-shell structure was prepared by a simple synthetic strategy using solvothermal crystallization of titanium precursor on preformed Fe3O4 nanopartiles. The photo-degradation reaction of neutral red aqueous solution was tested to evaluate the visible-light photocatalytic activity of the as prepared Fe3O4@TiO2 nanoparticles, which show excellent photocatalytic activity compared with commercial P25 catalyst. Moreover, the Fe3O4@TiO2 nanocomposites can be easily separated from the reaction mixture, and maintain favorable photocatalytic activity after five cycles. The high visible light absorption of the Fe3O4@TiO2 nanocomposites may originate from the absence of electronic heterojunction, excellently dispersity and the high specific surface area of the as-synthesized Fe3O4@TiO2 samples.

  19. Waste Treatment Technology Process Development Plan For Hanford Waste Treatment Plant Low Activity Waste Recycle

    McCabe, Daniel J.; Wilmarth, William R.; Nash, Charles A.

    2013-08-29

    The purpose of this Process Development Plan is to summarize the objectives and plans for the technology development activities for an alternative path for disposition of the recycle stream that will be generated in the Hanford Waste Treatment Plant Low Activity Waste (LAW) vitrification facility (LAW Recycle). This plan covers the first phase of the development activities. The baseline plan for disposition of this stream is to recycle it to the WTP Pretreatment Facility, where it will be concentrated by evaporation and returned to the LAW vitrification facility. Because this stream contains components that are volatile at melter temperatures and are also problematic for the glass waste form, they accumulate in the Recycle stream, exacerbating their impact on the number of LAW glass containers. Approximately 32% of the sodium in Supplemental LAW comes from glass formers used to make the extra glass to dilute the halides to acceptable concentrations in the LAW glass, and reducing the halides in the Recycle is a key component of this work. Additionally, under possible scenarios where the LAW vitrification facility commences operation prior to the WTP Pretreatment facility, this stream does not have a proven disposition path, and resolving this gap becomes vitally important. This task seeks to examine the impact of potential future disposition of this stream in the Hanford tank farms, and to develop a process that will remove radionuclides from this stream and allow its diversion to another disposition path, greatly decreasing the LAW vitrification mission duration and quantity of glass waste. The origin of this LAW Recycle stream will be from the Submerged Bed Scrubber (SBS) and the Wet Electrostatic Precipitator (WESP) from the LAW melter off-gas system. The stream is expected to be a dilute salt solution with near neutral pH, and will likely contain some insoluble solids from melter carryover or precipitates of scrubbed components (e.g. carbonates). The soluble

  20. [Activity of hydrogen sulfide production enzymes in kidneys of rats].

    Mel'nyk, A V; Pentiuk, O O

    2009-01-01

    An experimental research of activity and kinetic descriptions of enzymes participating in formation of hydrogen sulfide in the kidney of rats has been carried out. It was established that cystein, homocystein and thiosulphate are the basic substrates for hydrogen sulfide synthesis. The higest activity for hydrogen sulfide production belongs to thiosulfate-dithiolsulfurtransferase and cysteine aminotransferase, less activity is characteristic of cystathionine beta-synthase and cystathio-nine gamma-lyase. The highest affinity to substrate is registered for thiosulfate-dithiolsulfurtransferase and cystathionine gamma-lyase. It is discovered that the substrate inhibition is typical of all hydrogen sulfide formation enzymes, although this characteristic is the most expressed thiosulfat-dithiolsulfurtransferase. PMID:20387629

  1. Synthesis and Antiviral Activity of Hydrogenated Ferulic Acid Derivatives

    Can Cui; Zhi-Peng Wang; Xiu-jiang Du; Li-Zhong Wang; Shu-Jing Yu; Xing-Hai Liu; Zheng-Ming Li; Wei-Guang Zhao

    2013-01-01

    A series of hydrogenated ferulic acid amide derivatives 4 were synthesized. The molecular structures of the synthesized compounds were analyzed by H1 NMR and HRMS. The biological activity study showed that some of them displayed excellent protection activity and curative activity against TMV at 500 μg/mL.

  2. Hydrogen Energy Storage (HES) Activities at NREL; NREL (National Renewable Energy Laboratory)

    Eichman, J.

    2015-04-21

    This presentation provides an overview of hydrogen and energy storage, including hydrogen storage pathways and international power-to-gas activities, and summarizes the National Renewable Energy Laboratory's hydrogen energy storage activities and results.

  3. Investigation of the Electrocatalytic Activity of Rhodium Sulfide for Hydrogen Evolution and Hydrogen Oxidation

    We report the synthesis of unsupported and carbon-supported, mixed phase, rhodium sulfide, using both a hydrogen sulfide source and a solid sulfur source. Samples with several different distributions of rhodium sulfide phases (Rh2S3, Rh17S15, RhS2 and metallic Rh) were obtained by varying the temperature and exposure time to H2S or sulfur to rhodium ratio when using solid sulfur. Samples were characterized by X-ray diffraction (XRD), and the unsupported rhodium sulfide compounds studied using Raman spectroscopy to link Raman spectra to catalyst phases. The electrocatalytic activity of the rhodium sulfide compounds for hydrogen evolution and oxidation was measured using rotating disk electrode measurements in acidic conditions to simulate use in a flow cell. The most active phases for hydrogen evolution were found to be Rh3S4 and Rh17S15 (−0.34 V vs. Ag/AgCl required for 20 mA/cm2), while Rh2S3 and RhS2 phases were relatively inactive (−0.46 V vs. Ag/AgCl required for 20 mA/cm2 using RhS2/C). The hydrogen oxidation activity of all rhodium sulfide phases is significantly lower than the hydrogen evolution activity and is not associated with conductivity limitations

  4. Effect of recycling activities on the heating value of solid waste: case study of the Greater Vancouver Regional District (Metro Vancouver).

    Abedini, Ali R; Atwater, James W; Fu, George Yuzhu

    2012-08-01

    Two main goals of the integrated solid waste management system (ISWMS) of Metro Vancouver (MV) include further recycling of waste and energy recovery via incineration of waste. These two very common goals, however, are not always compatible enough to fit in an ISWMS depending on waste characteristics and details of recycling programs. This study showed that recent recycling activities in MV have negatively affected the net heating value (NHV) of municipal solid waste (MSW) in this regional district. Results show that meeting MV's goal for additional recycling of MSW by 2015 will further reduce the NHV of waste, if additional recycling activities are solely focused on more extensive recycling of packaging materials (e.g. paper and plastic). It is concluded that 50% additional recycling of paper and plastic in MV will increase the overall recycling rate to 70% (as targeted by the MV for 2015) and result in more than 8% reduction in NHV of MSW. This reduction translates to up to 2.3 million Canadian dollar (CAD$) less revenue at a potential waste-to-energy (WTE) plant with 500 000 tonnes year(-1) capacity. Properly designed recycling programmes, however, can make this functional element of ISWMS compatible with green goals of energy recovery from waste. Herein an explanation of how communities can increase their recycling activities without affecting the feasibility of potential WTE projects is presented. PMID:22700857

  5. Atomic Layer Deposition of Pt Nanoparticles within the Cages of MIL-101: A Mild and Recyclable Hydrogenation Catalyst

    Karen Leus

    2016-03-01

    Full Text Available We present the in situ synthesis of Pt nanoparticles within MIL-101-Cr (MIL = Materials Institute Lavoisier by means of atomic layer deposition (ALD. The obtained Pt@MIL-101 materials were characterized by means of N2 adsorption and X-ray powder diffraction (XRPD measurements, showing that the structure of the metal organic framework was well preserved during the ALD deposition. X-ray fluorescence (XRF and transmission electron microscopy (TEM analysis confirmed the deposition of highly dispersed Pt nanoparticles with sizes determined by the MIL-101-Cr pore sizes and with an increased Pt loading for an increasing number of ALD cycles. The Pt@MIL-101 material was examined as catalyst in the hydrogenation of different linear and cyclic olefins at room temperature, showing full conversion for each substrate. Moreover, even under solvent free conditions, full conversion of the substrate was observed. A high concentration test has been performed showing that the Pt@MIL-101 is stable for a long reaction time without loss of activity, crystallinity and with very low Pt leaching.

  6. Demonstration of innovative partitioning processes for minor actinide recycling from high active waste solutions

    The recycling of the minor actinides (MA) using the Partitioning and Transmutation strategy (P and T) could contribute significantly to reducing the volume of high level waste in a geological repository and to decreasing the waste's longterm hazards originating from the long half-life of the actinides. Several extraction processes have been developed worldwide for the separation and recovery of MA from highly active raffinates (HAR, e.g. the PUREX raffinate). A multi-cycle separation strategy has been developed within the framework of European collaborative projects. The multi-cycle processes, on the one hand, make use of different extractants for every single process. Within the recent FP7 European research project ACSEPT (Actinide reCycling by SEParation and Transmutation), the development of new innovative separation processes with a reduced number of cycles was envisaged. In the so-called 'innovative SANEX' concept, the trivalent actinides and lanthanides are co-extracted from the PUREX raffinate by a DIAMEX like process (e.g. TODGA). Then, the loaded solvent is subjected to several stripping steps. The first one concerns selectively stripping the actinides(III) with selective water-soluble ligands (SO3-Ph-BTB), followed by the subsequent stripping of trivalent lanthanides. A more challenging route studied also within our laboratories is the direct actinide(III) separation from a PUREX-type raffinate using a mixture of CyMe4BTBP and TODGA as extractants, the so-called One cycle SANEX process. A new approach, which was also studied within the ACSEPT project, is the GANEX (Grouped ActiNide EXtraction) concept addressing the simultaneous partitioning of all transuranium (TRU) elements for their homogeneous recycling in advanced generation IV reactor systems. Bulk uranium is removed in the GANEX 1st cycle, e.g. using a monoamide extractant and the GANEX 2nd cycle then separates the TRU. A solvent composed of TODGA + DMDOHEMA in kerosene has been shown to

  7. Hydrogen uptake in vanadium first wall structures

    Simonen, E.P.; Jones, R.H. [Pacific Northwest National Laboratory, Richland, WA (United States)

    1996-04-01

    Evaluation of hydrogen sources and transport are needed to assess the mechanical integrity of V structures. Two sources include implantation and transmutation. The proposed coatings for the DEMO and ITER first wall strongly influence retention of hydrogen isotopes. Upper limit calculations of hydrogen inventory were based on recycling to the plasma and an impermeable coolant-side coating. Hydrogen isotope concentrations in V approaching 1,000 appm may be activated.

  8. Photocatalytic activity of titanium dioxide modified concrete materials - influence of utilizing recycled glass cullets as aggregates.

    Chen, Jun; Poon, Chi-Sun

    2009-08-01

    Combining the use of photocatalysts with cementitious materials is an important development in the field of photocatalytic air pollution mitigation. This paper presents the results of a systematic study on assessing the effectiveness of pollutant degradation by concrete surface layers that incorporate a photocatalytic material - Titanium Dioxide. The photocatalytic activity of the concrete samples was determined by photocatalytic oxidation of nitric oxide (NO) in the laboratory. Recycled glass cullets, derived from crushed waste beverage bottles, were used to replace sand in preparing the concrete surface layers. Factors, which may affect the pollutant removal performance of the concrete layers including glass color, aggregate size and curing age, were investigated. The results show a significant enhancement of the photocatalytic activity due to the use of glass cullets as aggregates in the concrete layers. The samples fabricated with clear glass cullets exhibited threefold NO removal efficiency compared to the samples fabricated with river sand. The light transmittance property of glass was postulated to account for the efficiency improvement, which was confirmed by a separate simulation study. But the influence of the size of glass cullets was not evident. In addition, the photocatalytic activity of concrete surface layers decreased with curing age, showing a loss of 20% photocatalytic activity after 56-day curing. PMID:19540649

  9. Chemical activation in view of MSWI bottom ash recycling in cement-based systems.

    Polettini, A; Pomi, R; Fortuna, E

    2009-03-15

    In the present study, the feasibility of recycling incinerator bottom ash in cementitious systems by means of chemical activation was investigated. Different Na-, K- and Ca-based hydroxides and salts were selected for the experiments on the basis of their recognized effects on activation of typical pozzolanic materials. The evolution of mechanical properties of bottom ash/Portland cement mixtures and the leaching of trace metals from the materials were a matter of major concern. The experiments were arranged according to a full factorial design, which also allowed to derive a predictive model for unconfined compressive strength as affected by bottom ash content as well as activator type and dosage. Among the activators tested, calcium chloride was found to affect mechanical strength far more positively than the other species used, at the same time ensuring low metal release from the material. On the other hand, the use of potassium sulfate was observed to cause a significant increase in metal leaching at pHettringite as soon as it converted into monosulfate over time. PMID:18632208

  10. Plasma Hypoxanthine-Guanine Phosphoribosyl Transferase Activity in Bottlenose Dolphins Contributes to Avoiding Accumulation of Non-recyclable Purines

    López-Cruz, Roberto I.; Crocker, Daniel E.; Gaxiola-Robles, Ramón; Bernal, Jaime A.; Real-Valle, Roberto A.; Lugo-Lugo, Orlando; Zenteno-Savín, Tania

    2016-01-01

    Marine mammals are exposed to ischemia/reperfusion and hypoxia/reoxygenation during diving. During oxygen deprivation, adenosine triphosphate (ATP) breakdown implies purine metabolite accumulation, which in humans is associated with pathological conditions. Purine recycling in seals increases in response to prolonged fasting and ischemia. Concentrations of metabolites and activities of key enzymes in purine metabolism were examined in plasma and red blood cells from bottlenose dolphins (Tursiops truncatus) and humans. Hypoxanthine and inosine monophosphate concentrations were higher in plasma from dolphins than humans. Plasma hypoxanthine-guanine phosphoribosyl transferase (HGPRT) activity in dolphins suggests an elevated purine recycling rate, and a mechanism for avoiding accumulation of non-recyclable purines (xanthine and uric acid). Red blood cell concentrations of hypoxanthine, adenosine diphosphate, ATP and guanosine triphosphate were lower in dolphins than in humans; adenosine monophosphate and nicotinamide adenine dinucleotide concentrations were higher in dolphins. HGPRT activity in red blood cells was higher in humans than in dolphins. The lower concentrations of purine catabolism and recycling by-products in plasma from dolphins could be beneficial in providing substrates for recovery of ATP depleted during diving or vigorous swimming. These results suggest that purine salvage in dolphins could be a mechanism for delivering nucleotide precursors to tissues with high ATP and guanosine triphosphate requirements. PMID:27375492

  11. Diffuse reflectance FTIR-spectroscopy for kinetic and mechanistic studies of CO2 hydrogenation in a continuous recycle reactor.

    Prairie, M. R.; Highfield, J. G.; Renken, A.

    1991-01-01

    The advantage of coupling a diffuse-reflectance infrared cell with a continuous-feed recycle reactor for in situ kinetic and mechanistic studies is illustrated in the study of CO2 methanation over Ru/TiO2. From transient and steady-state experiments, metal-adsorbed CO is identified as a major reaction intermediate and at 120°C occupies approximately 40% of the available ruthenium surface, while methane formation proceeds at a turnover frequency of 2.8 × 10-3 s-1. In contrast, CO methanation i...

  12. Scale-up activation of carbon fibres for hydrogen storage

    Kunowsky, Mirko; Marco Lozar, Juan Pablo; Cazorla Amorós, Diego; Linares Solano, Ángel

    2009-01-01

    In a previous study, we investigated, at a laboratory scale, the chemical activation of two different carbon fibres (CF), their porosity characterization, and their optimization for hydrogen storage [1]. In the present work, this study is extended to: (i) a larger range of KOH activated carbon fibres, (ii) a larger range of hydrogen adsorption measurements at different temperatures and pressures (i.e. at room temperature, up to 20 MPa, and at 77 K, up to 4 MPa), and (iii) a scaling-up activat...

  13. Recycling CO 2 ? Computational Considerations of the Activation of CO 2 with Homogeneous Transition Metal Catalysts

    Drees, Markus

    2012-08-10

    Faced with depleting fossil carbon sources, the search for alternative energy carriers and energy storage possibilities has become an important issue. Nature utilizes carbon dioxide as starting material for storing sun energy in plant hydrocarbons. A similar approach, storing energy from renewable sources in chemical bonds with CO 2 as starting material, may lead to partial recycling of CO 2 created by human industrial activities. Unfortunately, currently available routes for the transformation of CO 2 involve high temperatures and are often not selective. With the development of more sophisticated methods and better software, theoretical studies have become both increasingly widespread and useful. This concept article summarizes theoretical investigations of the current state of the feasibility of CO 2 activation with molecular transition metal catalysts, highlighting the most promising reactions of CO 2 with olefins to industrially relevant acrylic acid/acrylates, and the insertion of CO 2 into metal-element bonds, particularly for the synthesis of cyclic carbonates and polymers. Rapidly improving computational power and methods help to increase the importance and accuracy of calculations continuously and make computational chemistry a useful tool helping to solve some of the most important questions for the future. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Correlating hydrogen oxidation and evolution activity on platinum at different pH with measured hydrogen binding energy

    Sheng, WC; Zhuang, ZB; Gao, MR; Zheng, J; Chen, JGG; Yan, YS

    2015-01-08

    The hydrogen oxidation/evolution reactions are two of the most fundamental reactions in distributed renewable electrochemical energy conversion and storage systems. The identification of the reaction descriptor is therefore of critical importance for the rational catalyst design and development. Here we report the correlation between hydrogen oxidation/evolution activity and experimentally measured hydrogen binding energy for polycrystalline platinum examined in several buffer solutions in a wide range of electrolyte pH from 0 to 13. The hydrogen oxidation/evolution activity obtained using the rotating disk electrode method is found to decrease with the pH, while the hydrogen binding energy, obtained from cyclic voltammograms, linearly increases with the pH. Correlating the hydrogen oxidation/evolution activity to the hydrogen binding energy renders a monotonic decreasing hydrogen oxidation/evolution activity with the hydrogen binding energy, strongly supporting the hypothesis that hydrogen binding energy is the sole reaction descriptor for the hydrogen oxidation/evolution activity on monometallic platinum.

  15. Correlating hydrogen oxidation and evolution activity on platinum at different pH with measured hydrogen binding energy

    Sheng, Wenchao; Zhuang, Zhongbin; Gao, Minrui; Zheng, Jie; Chen, Jingguang G.; Yan, Yushan

    2015-01-01

    The hydrogen oxidation/evolution reactions are two of the most fundamental reactions in distributed renewable electrochemical energy conversion and storage systems. The identification of the reaction descriptor is therefore of critical importance for the rational catalyst design and development. Here we report the correlation between hydrogen oxidation/evolution activity and experimentally measured hydrogen binding energy for polycrystalline platinum examined in several buffer solutions in a wide range of electrolyte pH from 0 to 13. The hydrogen oxidation/evolution activity obtained using the rotating disk electrode method is found to decrease with the pH, while the hydrogen binding energy, obtained from cyclic voltammograms, linearly increases with the pH. Correlating the hydrogen oxidation/evolution activity to the hydrogen binding energy renders a monotonic decreasing hydrogen oxidation/evolution activity with the hydrogen binding energy, strongly supporting the hypothesis that hydrogen binding energy is the sole reaction descriptor for the hydrogen oxidation/evolution activity on monometallic platinum.

  16. Benchmarking survey for recycling.

    Marley, Margie Charlotte; Mizner, Jack Harry

    2005-06-01

    This report describes the methodology, analysis and conclusions of a comparison survey of recycling programs at ten Department of Energy sites including Sandia National Laboratories/New Mexico (SNL/NM). The goal of the survey was to compare SNL/NM's recycling performance with that of other federal facilities, and to identify activities and programs that could be implemented at SNL/NM to improve recycling performance.

  17. A novel framework for quantifying past methane recycling by Sphagnum-methanotroph symbiosis using carbon and hydrogen isotope ratios of leaf wax biomarkers

    Nichols, Jonathan E.; Isles, Peter D. F.; Peteet, Dorothy M.

    2014-05-01

    concentration of atmospheric methane is strongly linked to variations in Earth's climate. Currently, we can directly reconstruct the total atmospheric concentration of methane, but not individual terms of the methane cycle. Northern wetlands, dominated by Sphagnum, are an important contributor of atmospheric methane, and we seek to understand the methane cycle in these systems. We present a novel method for quantifying the proportion of carbon Sphagnum assimilates from its methanotrophic symbionts using stable isotope ratios of leaf-wax biomarkers. Carbon isotope ratios of Sphagnum compounds are determined by two competing influences, water content and the isotope ratio of source carbon. We disentangled these effects using a combined hydrogen and carbon isotope approach. We constrained Sphagnum water content using the contrast between the hydrogen isotope ratios of Sphagnum and vascular plant biomarkers. We then used Sphagnum water content to calculate the carbon isotope ratio of Sphagnum's carbon pool. Using a mass balance equation, we calculated the proportion of recycled methane contributed to the Sphagnum carbon pool, "PRM." We quantified PRM in peat monoliths from three microhabitats in the Mer Bleue peatland complex. Modern studies have shown that water table depth and vegetation have strong influences on the peatland methane cycle on instrumental time scales. With this new approach, δ13C of Sphagnum compounds are now a useful tool for investigating the relationships among hydrology, vegetation, and methanotrophy in Sphagnum peatlands over the time scales of entire peatland sediment records, vital to our understanding of the global carbon cycle through the Late Glacial and Holocene.

  18. A Novel Framework for Quantifying past Methane Recycling by Sphagnum-Methanotroph Symbiosis Using Carbon and Hydrogen Isotope Ratios of Leaf Wax Biomarkers

    Nichols, Jonathan E.; Isles, Peter D. F.; Peteet, Dorothy M.

    2014-01-01

    The concentration of atmospheric methane is strongly linked to variations in Earth's climate. Currently, we can directly reconstruct the total atmospheric concentration of methane, but not individual terms of the methane cycle. Northern wetlands, dominated by Sphagnum, are an important contributor of atmospheric methane, and we seek to understand the methane cycle in these systems. We present a novel method for quantifying the proportion of carbon Sphagnum assimilates from its methanotrophic symbionts using stable isotope ratios of leaf-wax biomarkers. Carbon isotope ratios of Sphagnum compounds are determined by two competing influences, water content and the isotope ratio of source carbon. We disentangled these effects using a combined hydrogen and carbon isotope approach. We constrained Sphagnum water content using the contrast between the hydrogen isotope ratios of Sphagnum and vascular plant biomarkers. We then used Sphagnum water content to calculate the carbon isotope ratio of Sphagnum's carbon pool. Using a mass balance equation, we calculated the proportion of recycled methane contributed to the Sphagnum carbon pool, 'PRM.' We quantified PRM in peat monoliths from three microhabitats in the Mer Bleue peatland complex. Modern studies have shown that water table depth and vegetation have strong influences on the peatland methane cycle on instrumental time scales. With this new approach, delta C-13 of Sphagnum compounds are now a useful tool for investigating the relationships among hydrology, vegetation, and methanotrophy in Sphagnum peatlands over the time scales of entire peatland sediment records, vital to our understanding of the global carbon cycle through the Late Glacial and Holocene.

  19. Resource and waste taxation in the theory of the firm with recycling activities

    The management of solid waste has become an urgent problem in nations with a great population density. Accordingly, waste reduction through source reduction and recycling has become increasingly important. Our purpose is to show how prevention, recycling and disposal of waste could be part of a theory of the firm. We first derive efficient production functions from production processes with waste as a by-product. Waste obtained as new scrap can partially be recycled by using additional inputs in order to cut back the purchase of virgin material. Waste not completely recyclable will leave the firm as disposal which also entails cost to the firm. We use the dual cost function approach to develop a theory of the firm under solid residual management. Since the producer does not bear the full cost of disposal, there will be a bias toward virgin materials and away from recycling. The goal of the government is to stimulate the firms to recycle with respect to the preservation of exhaustible resources. An incentive to recycle is a tax on resources or on waste. In order to determine the tax levels the government maximizes welfare subject to the dynamic constraint for decumulation of land fill for waste deposits. This gives the user cost and its time profile for taxing waste disposal or virgin material. In a comparative statistics analysis we compare the effect of taxes on waste vs. virgin material on effort to produce in a resource saving manner, on the quantity of recycled material, on output, and on the reduction of waste. Since the impact of environmental regulation on employment is important, our model detects seven effects on labor demand as part of resource conservation policy. We finally carry out a comparative statistics analysis of waste intensive firms operating in different market structures. Of interest is the impact of a resource or waste taxation on market volume, on the number of firms, on resource saving effort, and on profit. 36 refs

  20. ALKALI-ACTIVATED CEMENT MORTARS CONTAINING RECYCLED CLAY-BASED CONSTRUCTION AND DEMOLITION WASTE

    F. Puertas

    2015-09-01

    Full Text Available The use of clay-based waste as an aggregate for concrete production is an amply studied procedure. Nonetheless, research on the use of this recycled aggregate to prepare alkaline cement mortars and concretes has yet to be forthcoming. The present study aimed to determine: the behaviour of this waste as a pozzolan in OPC systems, the mechanical strength in OPC, alkali-activated slag (AAS and fly ash (AAFA mortars and the effect of partial replacement of the slag and ash themselves with ground fractions of the waste. The pozzolanic behaviour of clay-based waste was confirmed. Replacing up to 20 % of siliceous aggregate with waste aggregate in OPC mortars induced a decline in 7 day strength (around 23 wt. %. The behaviour of waste aggregate in AAMs mortars, in turn, was observed to depend on the nature of the aluminosilicate and the replacement ratio used. When 20 % of siliceous aggregate was replaced by waste aggregate in AAS mortars, the 7 day strength values remained the same (40 MPa. In AAFA mortars, waste was found to effectively replace both the fly ash and the aggregate. The highest strength for AAFA mortars was observed when they were prepared with both a 50 % replacement ratio for the ash and a 20 % ratio for the aggregate.

  1. Comparative study of wastewater treatment and nutrient recycle via activated sludge, microalgae and combination systems.

    Wang, Liang; Liu, Jinli; Zhao, Quanyu; Wei, Wei; Sun, Yuhan

    2016-07-01

    Algal-bacterial synergistic cultivation could be an optional wastewater treatment technology in temperate areas. In this study, a locally screened vigorous Chlorella strain was characterized and then it was used in a comparative study of wastewater treatment and nutrient recycle assessment via activated sludge (AS), microalgae and their combination systems. Chlorella sp. cultured with AS in light showed the best performance, in which case the removal efficiencies of COD, NH3-N and TP were 87.3%, 99.2% and 83.9%, respectively, within a short period of 1day. Algal-bacterial combination in light had the best settleability. Chlorella sp. contained biomass, could be processed to feed, fertilizer or fuel due to the improved quality (higher C/H/N) compared with sludge. PCR-DGGE analysis shows that two types of rhizobacteria, namely, Pseudomonas putida and Flavobacterium hauense were enriched in sludge when cultured with algae in light, serving as the basics for artificial consortium construction for improved wastewater treatment. PMID:26995615

  2. Rubber sheet strewn with TiO2 particles: Photocatalytic activity and recyclability

    Chaval Sriwong; Sumpun Wongnawa; Orasa Patarapaiboolchai

    2012-01-01

    A new method for the preparation of rubber sheet strewn with titanium dioxide particles(TiO2-strewn sheet)is presented.This simple and low cost method is based on the use of TiO2 powder(Degussa P25)being strewn onto the sheet made from rubber latex(60% HA)through a steel sieve.The characteristic of the TiO2-strewn sheet was studied by using scanning electron microscopy/energy dispersive X-ray spectrometer(SEM/EDS)and X-ray diffractometer(XRD)techniques.The photocatalytic activity of TiO2-strewn rubber sheet was evaluated using Indigo Carmine(IC)dye as a model for organic dye pollutant in water.The results showed that the TiO2-strewn sheet could degrade IC dye solution under UV light irradiation.The effects of pH,initial concentration,and the intensity of UV light on the photodegradation were also investigated.Kinetics of the photocatalytic degradation was of the first-order reaction.The used TiO2-strewn sheet can be recovered and reused.The recycling uses did not require any cleaning between successive uses and no decline in the photodegradation efficiency was observed compared with freshly prepared TiO2-strewn sheet.

  3. Utilization of recycled neutron source to teach prompt gamma analysis activation-PGNA

    Delgado-Correal, Camilo; Munera, Hector

    2008-03-01

    Neutron activation analysis based on prompt gamma ray emission has significantly developed during the past twenty years. The technique is particularly suited for the identification of low atomic number elements, as nitrogen that is a main component of drugs and explosives. Identification of these substances is important in the context of humanitarian demining, and in the control of illicit traffic of drugs and explosives. As a good example of recycling of radioactive sources, a ^241Am-Be neutron source emitting 10^7neutron/s, that was not longer in use for other purposes at Ingeominas, was used to build a neutron irradiator that can be used to teach prompt gamma ray analysis, and other nuclear techniques. We irradiated individual samples, each about 4 gram, of three different elements: nitrogen in urea, silicon in milled rock, and cadmium in cadmium oxide. The prompt gamma rays emitted in the nuclear reactions ^112Cd (neutron,gamma) ^113Cd, ^28Si (neutron,gamma) ^29Si and ^14N (neutron,gamma) ^15N were identified using a well-type NaI (Tl) detector, connected to a multi-channel analyzer.

  4. Allosteric activation of coagulation factor VIIa visualized by hydrogen exchange

    Rand, Kasper Dyrberg; Jørgensen, Thomas; Olsen, Ole H; Persson, Egon; Jensen, Ole; Stennicke, Henning R; Andersen, Mette

    2006-01-01

    Coagulation factor VIIa (FVIIa) is a serine protease that, after binding to tissue factor (TF), plays a pivotal role in the initiation of blood coagulation. We used hydrogen exchange monitored by mass spectrometry to visualize the details of FVIIa activation by comparing the exchange kinetics of ...... provide novel insights into the cofactor-induced activation of this important protease and reveal the potential for allosteric regulation in the trypsin family of proteases....

  5. Innovative Strategy on Hydrogen Evolution Reaction Utilizing Activated Liquid Water

    Hwang, Bing-Joe; Chen, Hsiao-Chien; Mai, Fu-Der; Tsai, Hui-Yen; Yang, Chih-Ping; Rick, John; Liu, Yu-Chuan

    2015-11-01

    Splitting water for hydrogen production using light, or electrical energy, is the most developed ‘green technique’. For increasing efficiency in hydrogen production, currently, the most exciting and thriving strategies are focused on efficient and inexpensive catalysts. Here, we report an innovative idea for efficient hydrogen evolution reaction (HER) utilizing plasmon-activated liquid water with reduced hydrogen-bonded structure by hot electron transfer. This strategy is effective for all HERs in acidic, basic and neutral systems, photocatalytic system with a g-C3N4 (graphite carbon nitride) electrode, as well as in an inert system with an ITO (indium tin oxide) electrode. Compared to deionized water, the efficiency of HER increases by 48% based on activated water ex situ on a Pt electrode. Increase in energy efficiency from activated water is 18% at a specific current yield of -20 mA in situ on a nanoscale-granulated Au electrode. Moreover, the onset potential of -0.023 V vs RHE was very close to the thermodynamic potential of the HER (0 V). The measured current density at the corresponding overpotential for HER in an acidic system was higher than any data previously reported in the literature. This approach establishes a new vista in clean green energy production.

  6. Structure of materials deposited on the plasma facing surface in TRIAM-1M tokamak and the effect on hydrogen recycling

    Microstructure and chemical composition of depositions in TRIAM-1M under long pulse discharges have been examined. It is found that the deposition has a defective structure; the grain size is approximately 1 nm and the crystalline structure is not the normal body centered cubic (bcc) but is a face centered cubic (fcc). By comparing with the vacuum-deposited molybdenum in various conditions, it is concluded that co-deposited oxygen plays an essential role for the defective structure. The vacuum-deposited molybdenum, which has the same structure as the depositions in TRIAM-1M, shows very large and strong hydrogen retention. Implanted deuteriums are desorbed as D2, DH, D2O and DHO. The present work indicates that re-deposition of sputtered atoms on plasma facing surfaces will be a serious problem even in a metallic tokamak. More attention should be paid to hydrogen retention in the deposited material

  7. Rationalizing the Hydrogen and Oxygen Evolution Reaction Activity of Two-Dimensional Hydrogenated Silicene and Germanene.

    Rupp, Caroline J; Chakraborty, Sudip; Anversa, Jonas; Baierle, Rogério J; Ahuja, Rajeev

    2016-01-20

    We have undertaken first-principles electronic structure calculations to show that the chemical functionalization of two-dimensional hydrogenated silicene (silicane) and germanene (germanane) can become a powerful tool to increase the photocatalytic water-splitting activity. Spin-polarized density functional theory within the GGA-PBE and HSE06 types of exchange correlation functionals has been used to obtain the structural, electronic, and optical properties of silicane and germanane functionalized with a series of nonmetals (N, P, and S), alkali metals (Li, Na, and K) and alkaline-earth metals (Mg and Ca). The surface-adsorbate interaction between the functionalized systems with H2 and O2 molecules that leads to envisaged hydrogen and oxygen evolution reaction activity has been determined. PMID:26704530

  8. Catalytic hydrothermal gasification of algae for hydrogen production: composition of reaction products and potential for nutrient recycling.

    Onwudili, Jude A; Lea-Langton, Amanda R; Ross, Andrew B; Williams, Paul T

    2013-01-01

    Chlorella vulgaris, Spirulina platensis and Saccharina latissima were processed under supercritical water gasification conditions at 500 °C, 36 MPa in an Inconel batch reactor for 30 min in the presence/absence of NaOH and/or Ni-Al(2)O(3). Hydrogen gas yields were more than two times higher in the presence of NaOH than in its absence and tar yields were reduced by up to 71%. Saccharina, a carbohydrate-rich macro-alga, gave the highest hydrogen gas yields of 15.1 mol/kg. The tars from all three algae contained aromatic compounds, including phenols, alkyl benzenes and polycyclic aromatic hydrocarbons as well as heterocyclic nitrogen compounds. Tars from Chlorella and Spirulina contained high yields of pyridines, pyrroles, indoles and pyrimidines. Up to 97% TOC removal were achieved in the process waters from the gasification of the algae. Analyses for specific nutrients in the process waters indicated that the process waters from Saccharina could potentially be used for microalgae cultivation. PMID:23131625

  9. HYDROGEN SULFIDE ADSORPTION BY ALKALINE IMPREGNATED COCONUT SHELL ACTIVATED CARBON

    HUI SUN CHOO; LEE CHUNG LAU; ABDUL RAHMAN MOHAMED; KEAT TEONG LEE

    2013-01-01

    Biogas is one type of renewable energy which can be burnt to produce heat and electricity. However, it cannot be burnt directly due to the presence of hydrogen sulfide (H2S) which is highly corrosive to gas engine. In this study, coconut shell activated carbon (CSAC) was applied as a porous adsorbent for H2S removal. The effect of amount of activated carbon and flow rate of gas stream toward adsorption capacity were investigated. Then, the activated carbons were impregnated by three types of ...

  10. Nuclear recycling

    This paper discusses two aspects of the economics of recycling nuclear fuel: the actual costs and savings of the recycling operation in terms of money spent, made, and saved; and the impact of the recycling on the future cost of uranium. The authors review the relevant physical and chemical processes involved in the recycling process. Recovery of uranium and plutonium is discussed. Fuel recycling in LWRs is examined and a table presents the costs of reprocessing and not reprocessing. The subject of plutonium in fast reactors is addressed. Safeguards and weapons proliferation are discussed

  11. Development of methane conversion improvement method by recycling of residual methane for steam reforming as a part of R and D of HTGR-hydrogen production system

    The purpose of the present study is to improve methane conversion for an HTGR-steam reforming system by recycling of residual methane. The residual methane in a product gas after steam reforming was recycled with a gas separator of polyimide membrane. Gas separation characteristics of the separator were investigated experimentally and numerically, and an experimental study on recycling system was carried out. The results showed that the recycling system improves apparent methane conversion, ratio of methane conversion to methane supply from a cylinder, from 20 to 32% compared with those without recycling. (author)

  12. Hydrogen desorption reactions of Li-N-H hydrogen storage system: Estimation of activation free energy

    The dehydrogenation reactions of the mixtures of lithium amide (LiNH2) and lithium hydride (LiH) were studied under an Ar atmosphere by means of temperature programmed desorption (TPD) technique. The dehydrogenation reaction of the LiNH2/LiH mixture was accelerated by addition of 1 mol% Ti(III) species (k = 3.1 x 10-4 s-1 at 493 K), and prolonged ball-milling time (16 h) further enhanced reaction rate (k = 1.1 x 10-3 s-1 at 493 K). For the hydrogen desorption reaction of Ti(III) doped samples, the activation energies estimated by Kissinger plot (95 kJ mol-1) and Arrhenius plot (110 kJ mol-1) were in reasonable agreement. The LiNH2/LiH mixture without Ti(III) species, exhibited slower hydrogen desorption process and the kinetic traces deviated from single exponential behavior. The results indicated the Ti(III) additives change the hydrogen desorption reaction mechanism of the LiNH2/LiH mixture

  13. THE EFFECT OF THE SLUDGE RECYCLE RATIO IN AN ACTIVATED SLUDGE SYSTEM FOR THE TREATMENT OF AMOL'S INDUSTRIAL PARK WASTEWATER

    BAHAR HOSSEINI

    2008-09-01

    Full Text Available An activated sludge aeration tank and a sedimentation basin were used to treat Amol’s industrial park effluents originating from all industrial units. A continuous system was implemented and the kinetic parameters were measured.The parameters such as rate constant, substrate utilization rate constant, yield and decay coefficient were 2.12 d-1, 232.4 mg l-1, 0.33 g/g of substrate and 0.096 d−1, respectively. The hydraulic retention times (HRT were in the range of 9 to 27 h. The sludge recycle ratios in the range from 0.3 to 1 were considered. The COD removal, SVI and DO were determined and the optimal values were obtained. It was observed that at HRT of 16 h and the sludge recycle ratio of 0.85, the COD removal and SVI were 95 and 85 %, respectively. The sludge recycle ratio greater than 0.85 had no significant effect on the COD removal.

  14. Recycling and Activity Recovery of Chloroaluminate Ionic Liquid as Catalyst for Alkylation of Benzene with 1-Dodecene

    乔聪震; 李成岳

    2006-01-01

    Performances of 1-butyl-3-methylimidazolium aluminium chloride ([BMIM]Cl-AlCl3) ionic liquid as catalyst for the alkylation of benzene with long chain olefins were investigated in a continuous operation mode. A small pilot plant with continuous mixing-reacting-separating-recycling functions, equipped with a static mixer reactor, a tube packed with metal Al thread and a combined liquid-liquid settling phase separator, was introduced as an alternative. The results showed that the continuous fast mixing and separation of ionic liquid catalyst from reactant mixture could be synchronously accomplished within a wider flow rate ratio range of the recycling reaction mixture to the ionic liquid catalyst. The recycling of chloroaluminate ionic liquid was realized. ICP-AES detection results of Al content in the reactants proves that in-situ Al compensation to the reaction system may be an important choice to prolong the stable running time of moisture-sensitive ionic liquid [BMIM]Cl-AlCl3 when feedstock inevitably contains trace water. It suggests that the activity of chloroaluminate ionic liquid is recovered under the in-situ Al compensation operation.

  15. Hydrogen and fuel cell activity report - France 2009

    The report gathers the main outstanding facts which occurred in France in the field of hydrogen and fuel cells in 2009. After having noticed some initiatives (French commitment in renewable energy production, new role for the CEA, cooperation between different research and industrial bodies, development of electric vehicles, research programs), the report presents several projects and programs regarding hydrogen: ANR programs, creation of a national structure, basic research by the CEA and CNRS, demonstration projects (H2E), transport applications (a hybrid 307 by Peugeot, the Althytude project by GDF and Suez, the Hychain European project by Air Liquide, a dirigible airship, an ultra-light aviation project, a submarine), some stationary applications (the Myrte project, a wind energy project), activity in small and medium-sized enterprises, regional initiatives, colloquiums and meetings.

  16. Hydrogen and fuel cell activity report - France 2010

    The report gathers the main outstanding facts which occurred in France in the field of hydrogen and fuel cells in 2010. After having noticed some initiatives (the Grenelle II law, an investment package, the new role of the CEA, the new role of the IFP), the report presents several projects and programs regarding hydrogen: ANR programs, creation of a national structure (the HyPaC platform), regional initiatives and local actions, colloquiums and meetings in France and in the world, research projects (photo-synthesis as a new electric energy source), a technical-economic investigation (HyFrance3), demonstrator projects (the Althytude project by GDF and Suez, the Plathee hybrid locomotive by the SNCF, the H2E project, the Zero CO2 sailing boat, and the Myrte project), educational applications, activity in small and medium-sized enterprises (CETH, SAGIM, HYCAN, McPhy, N-GHY).

  17. Enhanced photocatalytic activity of hydrothermally grown BiFeO3 nanostructures and role of catalyst recyclability in photocatalysis based on magnetic framework

    Dhanalakshmi, Radhalayam; Muneeswaran, M.; Vanga, Pradeep Reddy; Ashok, M.; Giridharan, N. V.

    2016-01-01

    The photocatalytic activity of bismuth ferrite (BiFeO3: BFO) nanostructures on the degradation of methyl violet 2B (MV) is demonstrated for the first time under sunlight irradiation with the efficiency of 97.6 %. The photocatalytic BFO nanostructures have been successfully synthesized through hydrothermal method. Initial characterization of BFO nanostructures such as structural, functional, morphological, optical, and magnetic properties has been performed. From the X-ray diffraction analysis, the synthesized nanostructures are found to have rhombohedral structure with R3c space group confirmed by Rietveld analysis. The formation of perovskite structure is confirmed through FTIR analysis. Nanostructures were found to have rod-like morphology with the length between 15 and 20 nm and diameter of about 2-3 nm measured through HR-TEM. The surface area and N2 adsorption-desorption isotherms have been preformed through BET analysis. The optical band gap investigation shows that the E g value of BFO is about 2.1 eV. The magnetization measurements revealed a weak ferromagnetic behavior at room temperature, and the same has been confirmed through ABK plot. The photocatalytic activity of BFO is tested on the degradation of harmful MV dye under the irradiation of direct sunlight, influences of oxygen, and hydrogen peroxide. The photodecomposition kinetics of MV has been described through Langmuir-Hinshelwood model. The stability and recyclability of catalyst have also been studied.

  18. In vitro structure-activity relationship of Re-cyclized octreotide analogues

    Introduction: Development of radiolabeled octreotide analogues is of interest for targeting somatostatin receptor (SSTR)-positive tumors for diagnostic and therapeutic purposes. We are investigating a direct labeling approach for incorporation of a Re ion into octreotide analogues, where the peptide sequences are cyclized via coordination to Re rather than through a disulfide bridge. Methods: Various octreotide analogue sequences and coordination systems (e.g., S2N2 and S3N) were synthesized and cyclized with nonradioactive Re. In vitro competitive binding assays with 111In-DOTA-Tyr3-octreotide in AR42J rat pancreatic tumor cells yielded IC50 values as a measure of SSTR affinity of the Re-cyclized analogues. Three-dimensional structures of Re-cyclized Tyr3-octreotate and its disulfide-bridged analogue were calculated from two-dimensional NMR experiments to visualize the effect of metal cyclization on the analogue's pharmacophore. Results: Only two of the 11 Re-cyclized analogues investigated showed moderate in vitro binding affinity toward somatostatin subtype 2 receptors. Three-dimensional molecular structures of Re- and disulfide-cyclized Tyr3-octreotate were calculated, and both of their pharmacophore turns appear to be very similar with minor differences due to metal coordination to the amide nitrogen of one of the pharmacophore amino acids. Conclusions: Various Re-cyclized analogues were developed and analogue 4 had moderate affinity toward somatostatin subtype 2 receptors. In vitro stable studies that are in progress showed stable radiometal cyclization of octreotide analogues via NS3 and N2S2 coordination forming five- and six-membered chelate rings. In vivo biodistribution studies are underway of 99mTc-cyclized analogue 4.

  19. In vitro structure-activity relationship of Re-cyclized octreotide analogues

    Dannoon, Shorouk F. [Department of Chemistry, University of Missouri, Columbia, MO 65211 (United States); Bigott-Hennkens, Heather M. [Department of Veterinary Medicine and Surgery, University of Missouri, Columbia, MO 65211 (United States); Ma Lixin [Department of Radiology, University of Missouri, Columbia, MO 65211 (United States); International Institute of Nano and Molecular Medicine, University of Missouri, Columbia, MO 65211 (United States); Nuclear Science and Engineering Institute, University of Missouri, Columbia, MO 65211 (United States); Research Service, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO 65201 (United States); Gallazzi, Fabio [Structural Biology Core, University of Missouri, Columbia, MO 65211 (United States); Lewis, Michael R., E-mail: lewismic@missouri.ed [Department of Veterinary Medicine and Surgery, University of Missouri, Columbia, MO 65211 (United States); Department of Radiology, University of Missouri, Columbia, MO 65211 (United States); Nuclear Science and Engineering Institute, University of Missouri, Columbia, MO 65211 (United States); Research Service, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO 65201 (United States); Jurisson, Silvia S., E-mail: jurissons@missouri.ed [Department of Chemistry, University of Missouri, Columbia, MO 65211 (United States); Department of Radiology, University of Missouri, Columbia, MO 65211 (United States); Nuclear Science and Engineering Institute, University of Missouri, Columbia, MO 65211 (United States)

    2010-07-15

    Introduction: Development of radiolabeled octreotide analogues is of interest for targeting somatostatin receptor (SSTR)-positive tumors for diagnostic and therapeutic purposes. We are investigating a direct labeling approach for incorporation of a Re ion into octreotide analogues, where the peptide sequences are cyclized via coordination to Re rather than through a disulfide bridge. Methods: Various octreotide analogue sequences and coordination systems (e.g., S{sub 2}N{sub 2} and S{sub 3}N) were synthesized and cyclized with nonradioactive Re. In vitro competitive binding assays with {sup 111}In-DOTA-Tyr{sup 3}-octreotide in AR42J rat pancreatic tumor cells yielded IC{sub 50} values as a measure of SSTR affinity of the Re-cyclized analogues. Three-dimensional structures of Re-cyclized Tyr{sup 3}-octreotate and its disulfide-bridged analogue were calculated from two-dimensional NMR experiments to visualize the effect of metal cyclization on the analogue's pharmacophore. Results: Only two of the 11 Re-cyclized analogues investigated showed moderate in vitro binding affinity toward somatostatin subtype 2 receptors. Three-dimensional molecular structures of Re- and disulfide-cyclized Tyr{sup 3}-octreotate were calculated, and both of their pharmacophore turns appear to be very similar with minor differences due to metal coordination to the amide nitrogen of one of the pharmacophore amino acids. Conclusions: Various Re-cyclized analogues were developed and analogue 4 had moderate affinity toward somatostatin subtype 2 receptors. In vitro stable studies that are in progress showed stable radiometal cyclization of octreotide analogues via NS{sub 3} and N{sub 2}S{sub 2} coordination forming five- and six-membered chelate rings. In vivo biodistribution studies are underway of {sup 99m}Tc-cyclized analogue 4.

  20. THE EFFECT OF THE SLUDGE RECYCLE RATIO IN AN ACTIVATED SLUDGE SYSTEM FOR THE TREATMENT OF AMOL'S INDUSTRIAL PARK WASTEWATER

    BAHAR HOSSEINI; GHASEM NAJAFPOUR DARZI; MAEDEH SADEGHPOUR; MOSTAFA ASADI

    2008-01-01

    An activated sludge aeration tank and a sedimentation basin were used to treat Amol’s industrial park effluents originating from all industrial units. A continuous system was implemented and the kinetic parameters were measured.The parameters such as rate constant, substrate utilization rate constant, yield and decay coefficient were 2.12 d-1, 232.4 mg l-1, 0.33 g/g of substrate and 0.096 d−1, respectively. The hydraulic retention times (HRT) were in the range of 9 to 27 h. The sludge recycle...

  1. Initial integration of accident safety, waste management, recycling, effluent, and maintenance considerations for low-activation materials

    A true low-activation material should ideally achieve all of the following objectives: 1. The possible prompt dose at the site boundary from 100% release of the inventory should be <2 Sv (200 rem); hence, the design would be inherently safe in that no possible accident could result in prompt radiation fatalities. 2. The possible cancers from realistic releases should be limited such that the accident risk is <0.1%/yr of the existing background cancer risk to local residents. This includes consideration of elemental volatility. 3. The decay heat should be limited so that active mitigative measures are not needed to protect the investment from cooling transients; hence, the design would be passively safe with respect to decay heat. 4. Used materials could be either recycled or disposed of as near- surface waste. 5. Hands-on maintenance should be possible around coolant system piping and components such as the heat exchanger. 6. Effluent of activation products should be minor compared to the major challenge of limiting tritium effluents. The most recent studies in these areas are used to determine which individual elements and engineering materials are low activation. Grades from A (best) to G (worst) are given to each element in the areas of accident safety, recycling, and waste management. Structure/fluid combinations are examined for low-activation effluents and out-of-blanket maintenance. The lowest activation structural materials are silicon carbide, vanadium alloys, and ferritic steels. Impurities and minor alloying constituents must be carefully considered. The lowest activation coolants are helium, water, FLiBe, and lithium. The lowest activation breeders are lithium, lithium oxide, lithium silicate, and FLiBe. Designs focusing on these truly low-activation materials will help achieve the excellent safety and environmental potential of fusion energy

  2. The maximum specific hydrogen-producing activity of anaerobic mixed cultures: definition and determination

    Mu, Yang; Yang, Hou-Yun; Wang, Ya-Zhou; He, Chuan-Shu; Zhao, Quan-Bao; Yi WANG; Yu, Han-Qing

    2014-01-01

    Fermentative hydrogen production from wastes has many advantages compared to various chemical methods. Methodology for characterizing the hydrogen-producing activity of anaerobic mixed cultures is essential for monitoring reactor operation in fermentative hydrogen production, however there is lack of such kind of standardized methodologies. In the present study, a new index, i.e., the maximum specific hydrogen-producing activity (SHAm) of anaerobic mixed cultures, was proposed, and consequent...

  3. Activated carbon becomes active for oxygen reduction and hydrogen evolution reactions.

    Yan, Xuecheng; Jia, Yi; Odedairo, Taiwo; Zhao, Xiaojun; Jin, Zhao; Zhu, Zhonghua; Yao, Xiangdong

    2016-06-21

    We utilized a facile method for creating unique defects in the activated carbon (AC), which makes it highly active for the oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER). The ORR activity of the defective AC (D-AC) is comparable to the commercial Pt/C in alkaline medium, and the D-AC also exhibits excellent HER activity in acidic solution. PMID:27277286

  4. Synthesis, characterization and catalytic activity of CoFe{sub 2}O{sub 4}-APTES-Pd magnetic recyclable catalyst

    Demirelli, M. [Department of Chemistry, Faculty of Arts and Sciences, Yıldız Teknik University Davutpaşa Campus, Esenler, İstanbul (Turkey); Department of Chemistry, Faculty of Arts and Sciences, Fatih University, B. Cekmece, İstanbul 34500 (Turkey); Karaoğlu, E., E-mail: ebubekirkaraoglu@gmail.com [Department of Chemistry, Faculty of Arts and Sciences, Fatih University, B. Cekmece, İstanbul 34500 (Turkey); Department of Medical Biochemistry, Faculty of Medicine, Sakarya University, Korucuk, Sakarya (Turkey); Baykal, A. [Department of Chemistry, Faculty of Arts and Sciences, Fatih University, B. Cekmece, İstanbul 34500 (Turkey); Sözeri, H.; Uysal, E. [TUBITAK-UME, National Metrology Institute, PO Box 54, 41470 Gebze, Kocaeli (Turkey)

    2014-01-05

    Highlights: • CoFe{sub 2}O{sub 4}-APTES-Pd (0) nanocomposite, as effective catalysts for reduction reactions. • It could be reused several times without significant loss in hydrogenation reaction. • So far, CoFe{sub 2}O{sub 4}-APTES-Pd (0) nanocomposite have not been synthesized. • CoFe{sub 2}O{sub 4}-APTES-Pd (0) nanocomposite was confirmed by XRD, FT-IR. • Pd containing nanoparticles embedded in organic surfactant observed by TEM. -- Abstract: A new magnetically recyclable catalyst, CoFe{sub 2}O{sub 4}-APTES-Pd(0) nanocomposite, as highly effective catalysts for reduction reactions in liquid phase was fabricated and characterized. The reduction of Pd{sup 2+} was accomplished with sodium borohydride (NaBH{sub 4}). The chemical characterization of the product was done with X-ray diffractometry, infrared spectroscopy, transmission electron microscopy, UV–Vis spectroscopy and inductively coupled plasma. It was found that the combination of CoFe{sub 2}O{sub 4} and 3-aminopropyltriethoxysilane (APTES) could give rise to structurally stable catalytic sites. Furthermore, the high magnetization CoFe{sub 2}O{sub 4}-APTES-Pd(0) catalyst can be recovered by magnet and reused for ten runs for hydrogenation reaction of 4-nitro aniline, 1,3 dinitro and cyclohexanone. The catalyst was easily isolated from the reaction mixture by a magnetic bar and reused at least 10 times without significant degradation in the activity which shows the indicative of a potential applications of these catalysts in industry.

  5. Activation and deactivation of a robust immobilized Cp*Ir-transfer hydrogenation catalyst: a multielement in situ X-ray absorption spectroscopy study.

    Sherborne, Grant J; Chapman, Michael R; Blacker, A John; Bourne, Richard A; Chamberlain, Thomas W; Crossley, Benjamin D; Lucas, Stephanie J; McGowan, Patrick C; Newton, Mark A; Screen, Thomas E O; Thompson, Paul; Willans, Charlotte E; Nguyen, Bao N

    2015-04-01

    A highly robust immobilized [Cp*IrCl2]2 precatalyst on Wang resin for transfer hydrogenation, which can be recycled up to 30 times, was studied using a novel combination of X-ray absorption spectroscopy (XAS) at Ir L3-edge, Cl K-edge, and K K-edge. These culminate in in situ XAS experiments that link structural changes of the Ir complex with its catalytic activity and its deactivation. Mercury poisoning and "hot filtration" experiments ruled out leached Ir as the active catalyst. Spectroscopic evidence indicates the exchange of one chloride ligand with an alkoxide to generate the active precatalyst. The exchange of the second chloride ligand, however, leads to a potassium alkoxide-iridate species as the deactivated form of this immobilized catalyst. These findings could be widely applicable to the many homogeneous transfer hydrogenation catalysts with Cp*IrCl substructure. PMID:25768298

  6. HYDROGEN SULFIDE ADSORPTION BY ALKALINE IMPREGNATED COCONUT SHELL ACTIVATED CARBON

    HUI SUN CHOO

    2013-12-01

    Full Text Available Biogas is one type of renewable energy which can be burnt to produce heat and electricity. However, it cannot be burnt directly due to the presence of hydrogen sulfide (H2S which is highly corrosive to gas engine. In this study, coconut shell activated carbon (CSAC was applied as a porous adsorbent for H2S removal. The effect of amount of activated carbon and flow rate of gas stream toward adsorption capacity were investigated. Then, the activated carbons were impregnated by three types of alkaline (NaOH, KOH and K2CO3 with various ratios. The effects of various types of alkaline and their impregnation ratio towards adsorption capacity were analysed. In addition, H2S influent concentration and the reaction temperature on H2S adsorption were also investigated. The result indicated that adsorption capacity increases with the amount of activated carbon and decreases with flow rate of gas stream. Alkaline impregnated activated carbons had better performance than unimpregnated activated carbon. Among all impregnated activated carbons, activated carbon impregnated by K2CO3 with ratio 2.0 gave the highest adsorption capacity. Its adsorption capacity was 25 times higher than unimpregnated activated carbon. The result also indicated that the adsorption capacity of impregnated activated carbon decreased with the increment of H2S influent concentration. Optimum temperature for H2S adsorption was found to be 50˚C. In this study, the adsorption of H2S on K2CO3 impregnated activated carbon was fitted to the Langmuir isotherm. The fresh and spent K2CO3 impregnated activated carbon were characterized to study the adsorption process.

  7. Recycling and Endogenous Cycles

    Fodha, Mouez; Francesco MAGRIS

    2012-01-01

    This article investigates the conditions under which deterministic cycles can emerge in a discrete-time model with infinitely lived agents and when the economy is characterized by two sectors producing two perfectly substitutable goods: a virgin good and a recycled one. The occurrence of deterministic fluctuations rests upon the countercyclical behavior of the recycling industry: an increase in present consumption implies a lower future waste activity together with a lower agents' total incom...

  8. Hydrogen bonds of anti-HIV active aminophenols

    Belkov, M. V.; Ksendzova, G. A.; Skornyakov, I. V.; Sorokin, V. L.; Tolstorozhev, G. B.; Shadyro, O. I.

    2011-05-01

    Analysis of IR-Fourier spectra from solutions and crystals of antiviral sulfo-containing aminophenols has shown that various types of intramolecular and intermolecular interactions can occur in molecules of these compounds. Three types of intramolecular hydrogen bonds (O-HṡṡṡN, O-HṡṡṡO=S=O, and N-HṡṡṡO=S=O) are formed in CCl4 solutions of the sulfo-containing aminophenols. The formation of intermolecular H-bonds involving the NH- and OH-groups and the preservation of the intramolecular O-HṡṡṡO=S=O H-bond are characteristic of the anti-HIV active aminophenol crystals. Spectral attributes are determined in order to distinguish between the anti-HIV active and inactive sulfo-containing aminophenols.

  9. Coal liquefaction with preasphaltene recycle

    Weimer, Robert F.; Miller, Robert N.

    1986-01-01

    A coal liquefaction system is disclosed with a novel preasphaltene recycle from a supercritical extraction unit to the slurry mix tank wherein the recycle stream contains at least 90% preasphaltenes (benzene insoluble, pyridine soluble organics) with other residual materials such as unconverted coal and ash. This subject process results in the production of asphaltene materials which can be subjected to hydrotreating to acquire a substitute for No. 6 fuel oil. The preasphaltene-predominant recycle reduces the hydrogen consumption for a process where asphaltene material is being sought.

  10. Recycling of greenhouse gases via methanol

    Bill, A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Eliasson, B.; Kogelschatz, U. [ABB Corporate Research Center, Baden-Daettwil (Switzerland)

    1997-06-01

    Greenhouse gas emissions to the atmosphere can be mitigated by using direct control technologies (capture, disposal or chemical recycling). We report on carbon dioxide and methane recycling with other chemicals, especially with hydrogen and oxygen, to methanol. Methanol synthesis from CO{sub 2} is investigated on various catalysts at moderate pressures ({<=}30 bar) and temperatures ({<=}300{sup o}C). The catalysts show good methanol activities and selectivities. The conversion of CO{sub 2} and CH{sub 4} to methanol is also studied in a silent electrical discharge at pressures of 1 to 4 bar and temperatures close to room temperature. Methanol yields are given for mixtures of CO{sub 2}/H{sub 2}, CH{sub 4}/O{sub 2} and also for CH{sub 4} and air mixtures. (author) 2 figs., 5 refs.

  11. "New" Compounds from Old Plastics: Recycling PET Plastics via Depolymerization. An Activity for the Undergraduate Organic Lab

    Kaufman, Don; Wright, Geoff; Kroemer, Ryan; Engel, Josh

    1999-11-01

    This paper describes work done to develop a meaningful undergraduate organic lab activity that illustrates chemistry of the real world while utilizing reactions typically included in the organic lecture and lab. We show how a common plastic can be converted into several compounds using ester hydrolysis and SN2 reactions. Contributing to the critical shortage of landfill space faced by many communities is the large quantity of plastic refuse. Thus, there is a real need to recycle plastic products. One way to recycle plastics such as polyethyleneterephthalate (PET), the polyester from which numerous consumer products such as 2-liter soda bottles are made, is to depolymerize them and then to use the resulting monomers to produce new products. PET is industrially depolymerized via an acid-catalyzed transesterification reaction conducted under conditions of high temperature and pressure that are not feasible in the undergraduate lab. Despite literature reports that PET is remarkably resistant to hydrolysis, we found that PET can be readily hydrolyzed by refluxing with potassium hydroxide or potassium tert-butoxide in amyl alcohol to give terephthalic acid in high yield. It is then possible to readily synthesize terephthalate diesters via SN2 reactions of ammonium terephthalate salts with alkyl halides. Fischer esterification can also be used to prepare the diesters, but yields are significantly lower.

  12. Field-scale monitoring of pharmaceutical compounds applied to active golf courses by recycled water.

    Young, M H; Green, R L; Conkle, J L; McCullough, M; Devitt, D A; Wright, L; Vanderford, B J; Snyder, S A

    2014-03-01

    The scarcity of potable water in arid and semiarid environments has led to the wider use of recycled water for irrigating agricultural fields, parks, golf courses, and other areas. One concern using recycled water as a source of irrigation has been the presence, fate, and transport of pharmaceutical compounds in water that percolates below the root zone of plants; however, very few multiyear field studies have been reported in the peer-reviewed literature. Here, we assessed compound mass flux of 13 pharmaceuticals in the fairways of four golf courses in the southwestern United States during a 2-yr field study. The sites varied by climate and soil type but were similar regarding turfgrass management. The results showed the presence of at least one pharmaceutical compound in nearly all samples collected, although concentrations were substantially lower after transport through the soil. Percent reduction in compound mass fluxes in drainage water was effectively 100% in 22 of 52 cases, 98 to 100% in 27 of 52 cases, and 73 to 94% in 3 of 52 cases (a case is defined as a specific compound measured at a specific site). Mass fluxes migrating below the root zone were calculated as 100 × 10 g ha in only two cases. For cases where the majority of the analyses were reportable, all fluxes were <8.80 × 10 g ha. Carbamazepine, meprobamate, and sulfamethoxazole were most commonly found in drainage water, representing nearly 80% of all reportable detections. This research demonstrates the potential of turfgrass/soil systems to reduce contaminant loading below the root zone and potentially toward groundwater. PMID:25602667

  13. Environmental assessment for the recycling of slightly activated copper coil windings from the 184-Inch Cyclotron at Lawrence Berkeley Laboratory, Berkeley, California

    1993-08-02

    The proposed action is to recycle slightly activated copper that is currently stored in a warehouse leased by Lawrence Berkeley Laboratory (LBL) to a scrap metal dealer. Subsequent reutilization of the copper would be unrestricted. This document addresses the potential environmental effects of recycling and reutilizing the activated copper. In addition, the potential environmental effects of possible future uses by the dealer are addressed. Direct environmental effects from the proposed action are assessed, such as air emissions from reprocessing the activated copper, as well as indirect beneficial effects, such as averting air emissions that would result from mining and smelting an equivalent quantity of copper ore. Evaluation of the human health impacts of the proposed action focuses on the pertinent issues of radiological doses and protection of workers and the public. Five alternatives to the proposed action are considered, and their associated potential impacts are addressed. The no-action alternative is the continued storage of the activated copper at the LBL warehouse. Two recycling alternatives are considered: recycling the activated copper at the Scientific Ecology Group (SEG) facility for re-use at a DOE facility and selling or giving the activated copper to a foreign government. In addition, two disposal alternatives evaluate the impacts attributable to disposing of the activated copper either at a local sanitary landfill or at the Hanford Low-Level Waste Burial Site. The proposed project and alternatives include no new construction or development of new industry.

  14. ASSESSMENT OF RECYCLED AGGREGATE CONCRETE

    Ahmad Mujahid Ahmad Zaidi

    2009-01-01

    Used of recycled aggregate (RA) in concrete can be described in environmental protection and economical terms. The application of recycled aggregate to use in construction activities have been practice by developed European countries and also of some Asian countries. This paper reports the results of an experimental study on the mechanical properties of recycled aggregate concrete (RAC) as compared to natural aggregate concrete (NAC). The effects of size of RA on compressive strength were dis...

  15. Lunar hydrogen: A resource for future use at lunar bases and space activities

    Gibson, Everett K., Jr.; Bustin, Roberta; Mckay, David S.

    1988-01-01

    Hydrogen abundances were determined for grain size separates of five lunar soils and one soil breccia. The hydrogen abundance studies have provided important baseline information for engineering models undergoing study at the present time. From the studies is appears that there is sufficient hydrogen present in selected lunar materials which could be recovered to support future space activities. It is well known that hydrogen can be extracted from lunar soils by heating between 400 and 800 C. Recovery of hydrogen for regolith materials would involve heating with solar mirrors and collecting the released hydrogen. Current baseline models for the lunar base are requiring the production of 1000 metric tons of oxygen per year. From this requirement it follows that around 117 metric tons per year of hydrogen would be required for the production of water. The ability to obtain hydrogen from the lunar regolith would assist in lowering the operating costs of any lunar base.

  16. Hydrogen

    John O’M. Bockris

    2011-01-01

    The idea of a “Hydrogen Economy” is that carbon containing fuels should be replaced by hydrogen, thus eliminating air pollution and growth of CO2 in the atmosphere. However, storage of a gas, its transport and reconversion to electricity doubles the cost of H2 from the electrolyzer. Methanol made with CO2 from the atmosphere is a zero carbon fuel created from inexhaustible components from the atmosphere. Extensive work on the splitting of water by bacteria shows that if wastes are used as the...

  17. Recycled Insect Models

    Rule, Audrey C.; Meyer, Mary Ann

    2007-01-01

    This article presents an engaging activity in which high school students use a dichotomous key to guide the creation and classification of model insects from recycled plastic lids and containers. Besides teaching the use of a dichotomous key and the effect of evolutionary descent upon groupings of organisms, this activity focuses on an…

  18. Recycling's technology

    A. Zajdel

    2007-04-01

    Full Text Available Purpose: Environmental problems have been considered as serious situation in the construction. Waste management is pressing harder with alarming signal warning the industry. This paper discusses the potential impact of biodegradable materials on waste management in terms of landfill, incineration, recycle/reuse composting.Design/methodology/approach: This article reviewed the implementation of strategies of WEEE treatment and the recovery technologies of WEEE. It presented the current status of WEEE and corresponding responses adopted.Findings: The possibility of managing the growing amount of waste and used appliances and equipment according to the accessible literature was shown and the importance of one of the most popular method of waste neutralization (recycling was underlined.Practical implications: The recycling of WEEE is important to introduce and develop cost-effective and environmentally friendly WEEE recycling technologies. it is also necessary to arouse and enhance public awareness regarding environmental protection by publicity, education and so forth, in order to change their traditional viewpoint on the end-of-life electric appliances or cars.Originality/value: This article discusses how environmental science and technology can be applied to hazardous waste management to develop measures by which chemical wastes can be minimized, recycled, treated and disposed.

  19. Effect of activity differences on hydrogen migration in dissimilar titanium alloy welds

    The effect of alloy composition on hydrogen activity was measured for seven titanium alloys as a means to determine the tendency for hydrogen migration within dissimilar metal welds. The alloys were: Ti-CP (unalloyed Ti), Ti-3Al-2.5V, Ti-3Al-2.5V-3Zr, Ti-3Al-2Nb-1Ta, Ti-6Al, Ti-6Al-4V, and Ti-6Al-2Nb-1Ta-0.8Mo. Hydrogen pressure-hydrogen concentration relationships were determined for temperatures from 600 C to 800 C and hydrogen concentrations up to approximately 3.5 at. pct (750 wppm). Fusion welds were made between Ti-CP and Ti-CP and between Ti-CP and Ti-6Al-4V to observe directly the hydrogen redistribution in similar and dissimilar metal couples. Hydrogen activity was found to be significantly affected by alloying elements, particularly Al in solid solution. At a constant Al content and temperature, an increase in the volume fraction of β reduced the activity of hydrogen in α-β alloys. Activity was also found to be strongly affected by temperature. The effect of temperature differences on hydrogen activity was much greater than the effects resulting from alloy composition differences at a given temperature. Thus, hydrogen redistribution should be expected within similar metal couples subjected to extreme temperature gradients, such as those peculiar to fusion welding. Significant hydrogen redistribution in dissimilar alloy weldments also can be expected for many of the compositions in this study. Hydride formation stemming from these driving forces was observed in the dissimilar couple fusion welds. In addition, a basis for estimating hydrogen migration in titanium welds, based on hydrogen activity data, is described

  20. Antibacterial activity of hydrogen peroxide and the lactoperoxidase-hydrogen peroxide-thiocyanate system against oral streptococci.

    Thomas, E L; Milligan, T W; Joyner, R E; Jefferson, M M

    1994-01-01

    In secreted fluids, the enzyme lactoperoxidase (LP) catalyzes the oxidation of thiocyanate ion (SCN-) by hydrogen peroxide (H2O2), producing the weak oxidizing agent hypothiocyanite (OSCN-), which has bacteriostatic activity. However, H2O2 has antibacterial activity in the absence of LP and thiocyanate (SCN-). Therefore, LP may increase antibacterial activity by using H2O2 to produce a more effective inhibitor of bacterial metabolism and growth, or LP may protect bacteria against the toxicity...

  1. Recycling of used perfluorosulfonic acid membranes

    Grot, Stephen; Grot, Walther

    2007-08-14

    A method for recovering and recycling catalyst coated fuel cell membranes includes dissolving the used membranes in water and solvent, heating the dissolved membranes under pressure and separating the components. Active membranes are produced from the recycled materials.

  2. Tire Recycling

    1997-01-01

    Cryopolymers, Inc. tapped NASA expertise to improve a process for recycling vehicle tires by converting shredded rubber into products that can be used in asphalt road beds, new tires, hoses, and other products. In conjunction with the Southern Technology Applications Center and Stennis Space Center, NASA expertise in cryogenic fuel-handling needed for launch vehicle and spacecraft operations was called upon to improve the recycling concept. Stennis advised Cryopolymers on the type of equipment required, as well as steps to reduce the amount of liquid nitrogen used in the process. They also guided the company to use more efficient ways to control system hardware. It is estimated that more than 300 million tires nationwide are produced per year. Cryopolymers expects to reach a production rate of 5,000 tires recycled per day.

  3. Hydrogen

    John O’M. Bockris

    2011-11-01

    Full Text Available The idea of a “Hydrogen Economy” is that carbon containing fuels should be replaced by hydrogen, thus eliminating air pollution and growth of CO2 in the atmosphere. However, storage of a gas, its transport and reconversion to electricity doubles the cost of H2 from the electrolyzer. Methanol made with CO2 from the atmosphere is a zero carbon fuel created from inexhaustible components from the atmosphere. Extensive work on the splitting of water by bacteria shows that if wastes are used as the origin of feed for certain bacteria, the cost for hydrogen becomes lower than any yet known. The first creation of hydrogen and electricity from light was carried out in 1976 by Ohashi et al. at Flinders University in Australia. Improvements in knowledge of the structure of the semiconductor-solution system used in a solar breakdown of water has led to the discovery of surface states which take part in giving rise to hydrogen (Khan. Photoelectrocatalysis made a ten times increase in the efficiency of the photo production of hydrogen from water. The use of two electrode cells; p and n semiconductors respectively, was first introduced by Uosaki in 1978. Most photoanodes decompose during the photoelectrolysis. To avoid this, it has been necessary to create a transparent shield between the semiconductor and its electronic properties and the solution. In this way, 8.5% at 25 °C and 9.5% at 50 °C has been reached in the photo dissociation of water (GaP and InAs by Kainthla and Barbara Zeleney in 1989. A large consortium has been funded by the US government at the California Institute of Technology under the direction of Nathan Lewis. The decomposition of water by light is the main aim of this group. Whether light will be the origin of the post fossil fuel supply of energy may be questionable, but the maximum program in this direction is likely to come from Cal. Tech.

  4. The maximum specific hydrogen-producing activity of anaerobic mixed cultures: definition and determination

    Mu, Yang; Yang, Hou-Yun; Wang, Ya-Zhou; He, Chuan-Shu; Zhao, Quan-Bao; Wang, Yi; Yu, Han-Qing

    2014-06-01

    Fermentative hydrogen production from wastes has many advantages compared to various chemical methods. Methodology for characterizing the hydrogen-producing activity of anaerobic mixed cultures is essential for monitoring reactor operation in fermentative hydrogen production, however there is lack of such kind of standardized methodologies. In the present study, a new index, i.e., the maximum specific hydrogen-producing activity (SHAm) of anaerobic mixed cultures, was proposed, and consequently a reliable and simple method, named SHAm test, was developed to determine it. Furthermore, the influences of various parameters on the SHAm value determination of anaerobic mixed cultures were evaluated. Additionally, this SHAm assay was tested for different types of substrates and bacterial inocula. Our results demonstrate that this novel SHAm assay was a rapid, accurate and simple methodology for determining the hydrogen-producing activity of anaerobic mixed cultures. Thus, application of this approach is beneficial to establishing a stable anaerobic hydrogen-producing system.

  5. Feasibility study of recycling cephalosporin C fermentation dregs using co-composting process with activated sludge as co-substrate.

    Chen, Zhiqiang; Wang, Yao; Wen, Qinxue; Zhang, Shihua; Yang, Lian

    2016-09-01

    Composting is a potential alternative for cephalosporin C fermentation dregs (CCFDs) compared with incineration process or landfill because of its advantage of recovering nutrients. In this research, CCFDs and activated sludge (AS) were co-composted to analyze the feasibility of recycling the nutrients in CCFDs. A pilot-scale aerobic composting system with an auto-control system was used in this research, and the maturity and security of the compost product were evaluated. The temperature of the composting mixtures was maintained above 55°C for more than 3 days during the composting, indicating that co-composting of CCFDs and AS could reach the compost maturity standard, and the seeds germination index (GI) increased from 17.61% to 68.93% by the end of the composting process (28 days). However, the degradation rate of cephalosporin C (CPC) was only 6.58% during the composting process. Monitoring the quality of antibiotic resistance genes (ARGs) in the composts showed that the log copy of blaTEM in the composts increased from 2.15 in the initial phase to 6.37 after 28 days. Long-term investigation of CPC degradation and ARGs variation was conducted for the composts; CPC could still be detected after the maturity phases. A removal efficiency of 49.10% could be achieved in 110 days, while the log copy of ARGs increased to 7.93. Although a higher GI value (>80.00%) was observed, the risk of recycling the CCFDs compost product into land is still high. PMID:26828961

  6. Bifunctional 4MBA mediated recyclable SERS-based immunoassay induced by photocatalytic activity of TiO2 nanotube arrays.

    Wang, Xiaolong; Zhou, Lu; Lai, Wei; Jiang, Tao; Zhou, Jun

    2016-09-14

    We first report here a novel recyclable surface-enhanced Raman scattering (SERS)-based immunoassay via the photocatalytic ability of anatase titania nanotube (TiO2-NT) arrays. In this immunoassay, an immune probe was realized by immobilizing anti-CA19-9 onto Ag@SiO2@Ag three core-shell nanoparticles (TCSNPs), which showed a much higher SERS activity than bare Ag NPs with an enhancement ratio of 1.75. Then, the vertically oriented TiO2-NT immune substrate was synthesized by ultra-fast anodic oxidation of flexible titanium foils and functionalised with 4-mercaptobenzoic acid (4MBA) molecules to link them with anti-CA19-9. The immunoassay using the above immune probe and the substrate exhibited a wide linear range from 1000 to 0.5 U mL(-1) and a low detection limit of 0.5 U mL(-1) for CA19-9 due to the excellent SERS performance of Ag@SiO2@Ag TCSNPs. More importantly, the linkage between TiO2-NTs and 4MBA was destroyed by catalyzing 4MBA into 4-sulfobenzoate upon UV irradiation in O2-saturated water. The target antigen and the immune probe were simultaneously removed leading to a recyclable immunoassay and a detection limit of 5 U mL(-1) was achieved after six cycles. The simplicity and versatility of this strategy may bridge the technology gap between academia and practical detection, which makes it promising for clinical SERS-based immunoassay. PMID:27523026

  7. Highly active, recyclable catalyst for the manufacture of viscous, low molecular weight, CO–ethene–propene-based polyketone, base component for a new class of resins

    Broekhuis, Antonius A.; Dirkzwager, Hendrik; Mul, Wilhelmus P.; Heeres, Hero J.; Linden, Adrianus J. van der; Orpen, A. Guy

    2002-01-01

    A highly active, recyclable homogeneous palladium(II) catalyst is described for the manufacture of viscous, low molecular weight CO–ethene–propene-based polyketone (Carilite Oligomer), used for the manufacture of a new class of resins (Carilite Resins). The catalyst is composed of palladium acetate,

  8. RECYCLING WITH ENDOGENEOUS CONSUMER PARTICIPATION

    2006-01-01

    We show that the cost of sorting and the network effects jointly determine the rate of participation of consumers in the process of recycling. The dominant producer of virgin material takes into account the recycling activities when it makes its pricing decision. The network effects can create multiplicity of steady-state equilibria. The government can improve welfare by influencing equilibrium selection.

  9. Hydrogenous Gas Production through Reactions among Supercritical Water, Ironmaking Sludge, and Steelmaking Slag and Recycling of Wastes from Integrated Steel Mills

    Hayashi, Shoji

    Automobile Shredder Residue (ASR) and Refuse derived fuels (not carbonized and carbonized: YRDF and RDF) as carbonaceous wastes were reacted isothermally with sub-supercritical water (600-695°C, 200 atm) together with a CO2 fixation reagent Ca(OH)2 inside a closed metallic tube reactor (7cm3). Product gas mainly consisted of hydrogen gas and a little methane gas except YRDF. As a whole, gas generated more in order ASR, YRDF, and RDF. Addition of catalysis NaOH or KOH made product gas increase more. KOH was more effective to product gas than NaOH. X-ray diffraction followed that Ca(OH)2 and CaCO3 existed mainly in residues after reaction tests with a CO2 fixation reagent Ca(OH)2 or CaO. Therefore, it was supposed that an overall chemical reaction took place as shown below. BOF steelmaking slag for CO2 fixation provided maximum gas generation 1.42 times as much as molar carbon in a RDF sample with KOH. C + H2O + Ca(OH)2 = CaCO3 + 2H2 Two kinds of wastes from integrated steel mills (sludge from mill scale and activated sludge) were each reacted with supercritical water (600-650°C, 200 atm). Both sludges were effective to generate hydrogenous gas. It was found that harmful cyan in the latter sludge mostly decomposed after reaction. Also, the crushing strength after curing the steelmaking slag bearing residue briquette was not as high as that from Portland cement.

  10. Activated carbons from African oil palm waste shells and fibre for hydrogen storage

    Liliana Giraldo; Maria Fernanda González-Navarro; Juan Carlos Moreno-Piraján

    2013-01-01

    We prepared a series of activated carbons by chemical activation with two strong bases in-group that few use, and I with waste from shell and fibers and oil-palm African. Activated carbons are obtained with relatively high surface areas (1605 m2/g). We study the textural and chemical properties and its effect on hydrogen storage. The activated carbons obtained from fibrous wastes exhibit a high hydrogen storage capacity of 6.0 wt % at 77 K and 12 bar.

  11. Adsorption of organic compounds onto activated carbons from recycled vegetables biomass.

    Mameli, Anna; Cincotti, Alberto; Lai, Nicola; Crisafulli, Carmelo; Sciré, Salvatore; Cao, Giacomo

    2004-01-01

    The removal of organic species from aqueous solution by activated carbons is investigated. The latter ones are prepared from olive husks and almond shells. A wide range of surface area values are obtained varying temperature and duration of both carbonization and activation steps. The adsorption isotherm of phenol, catechol and 2,6-dichlorophenol involving the activated carbons prepared are obtained at 25 degrees C. The corresponding behavior is quantitatively correlated using classical isotherm, whose parameters are estimated by fitting the equilibrium data. A two component isotherm (phenol/2,6-dichlorophenol) is determined in order to test activated carbon behavior during competitive adsorption. PMID:15347202

  12. Recycling fusion materials

    The inherent safety and environmental advantages of fusion power in comparison with other energy sources play an important role in the public acceptance. No waste burden for future generations is therefore one of the main arguments to decide for fusion power. The waste issue has thus been studied in several documents and the final conclusion of which it is stated that there is no permanent disposal waste needed if recycling is applied. But recycling of fusion reactor materials is far to be obvious regarding mostly the very high specific activity of the materials to be handled, the types of materials and the presence of tritium. The main objective of research performed by SCK-CEN is to study the possible ways of recycling fusion materials and analyse the challenges of the materials management from fusion reactors, based on current practices used in fission reactors and the requirements for the manufacture of fusion equipment

  13. Hydrogen inventory and embrittlement in low activation steels

    Results on hydrogen permeation and diffusion in virgin and preirradiated iron and martensitic MANET II are compared to literature data on iron and other ferritic/martensitic steels. Both permeability and diffusivity decrease with increasing alloying content. While preirradiation to 1.5 .10-3 dpa has negligible effect on permeation and diffusion, simultaneous irradiation enhances permeability in Fe and MANET II below ∼300 C. Diffusivity shows a strong pressure dependence and deviation from Arrhenius-type temperature dependence. Diffusion of implanted hydrogen shows a behaviour different from that derived from gas permeation. The hydrogen inventory in a fusion reactor blanket is roughly estimated and compared to the critical concentration for hydrogen embrittlement. Hardness of hydrogen implanted MANET II and F82H shows no pecularities compared to helium implantation and only slightly differs from irradiation without implantation. Tensile tests on F82H at 30 C and 200 C after implantation to hydrogen concentration above ∼10 wtppm show large variation, possibly due to formation of microcracks, while measurements at 350 C show no effect of implantation. (orig.)

  14. Influence of activated carbon amended ASBR on anaerobic fermentative hydrogen production

    Xie, Li; Wang, Lei; Zhou, Qi; Luo, Gang

    2013-01-01

    amended anazrobic seguencs batch reactor (ASBRs) was more stable than that of ASBRs without activated carbon addition regarding on hydrogen production and pH. Higher hydrogen yield(HY) and hydrogen producing rate(HPR) were observed in the activated carbon amended ASBRs, with 65%, 63%, 54%, 56% enhancement...... of hydrogen yield in smaller size activated carbon amended reactor under the tested HRT ranges, and the maximum HPR of (7.09±0.31)L·(L·d)-1 and HY of (1.42±0.03) mol·mol-1 was obtained at HRT of 12h. The major soluble products form hydrogen fermentation were n-butyric acid and acetic acid, accounting...

  15. Gold Supported on Graphene Oxide: An Active and Selective Catalyst for Phenylacetylene Hydrogenations at Low Temperatures

    Shao, Lidong; Huang, Xing; Teschner, Detre;

    2014-01-01

    A constraint to industrial implementation of gold-catalyzed alkyne hydrogenation is that the catalytic activity was always inferior to those of other noble metals. In this work, gold was supported on graphene oxide (Au/GO) and used in a hydrogenation application. A 99% selectivity toward styrene...

  16. Large sample activation analysis. Monitoring of photovoltaic module recycling using radioanalytical methods

    Photovoltaic modules are the most promising sources of renewable energy. According to respective EU Directives both the glass carrier material and the photo-active layer (CdTe in this study) shall be re-used. Analyses for process surveillance and control have to be carried out, primarily for monitoring of the separation efficiency and the enrichment level of CdTe. For on-site measurement and process control energy-dispersive X-ray fluorescence spectrometry was used. Instrumental photon activation analysis using an electron linear accelerator as activating bremsstrahlung source is intended to be used later for iterative intermediate analysis of random samples for quality control. In this work, the feasibility of both methods for this task was studied. (author)

  17. Catalytic activity of Ni3S2 and effects of reactor wall in hydrogen production from water with hydrogen sulphide as a reducer under hydrothermal conditions

    Catalytic activity of Ni3S2 and the effects of reactor wall in the hydrogen production from water were investigated under hydrothermal conditions using hydrogen sulphide (H2S) as a reductant. It was found that Ni3S2 catalysed the hydrogen production from water and may act as a semi-conductor catalyst. In the case of addition of Ni3S2, the time required to achieve the maximum hydrogen yield significantly decreased and the maximum hydrogen yield increased. These results suggest that the Ni3S2 formed as a corrosion product of the reactor wall when using the Hastelloy C-276 lined reactor should play a catalytic role in the hydrogen production. These results could facilitate studies for the synthesis of highly active catalysts for the production of hydrogen under mild conditions

  18. Development And Initial Testing Of Off-Gas Recycle Liquid From The WTP Low Activity Waste Vitrification Process - 14333

    McCabe, Daniel J.; Wilmarth, William R.; Nash, Charles A.; Taylor-Pashow, Kathryn M.; Adamson, Duane J.; Crawford, Charles L.; Morse, Megan M.

    2014-01-07

    The Waste Treatment and Immobilization Plant (WTP) process flow was designed to pre-treat feed from the Hanford tank farms, separate it into a High Level Waste (HLW) and Low Activity Waste (LAW) fraction and vitrify each fraction in separate facilities. Vitrification of the waste generates an aqueous condensate stream from the off-gas processes. This stream originates from two off-gas treatment unit operations, the Submerged Bed Scrubber (SBS) and the Wet Electrospray Precipitator (WESP). Currently, the baseline plan for disposition of the stream from the LAW melter is to recycle it to the Pretreatment facility where it gets evaporated and processed into the LAW melter again. If the Pretreatment facility is not available, the baseline disposition pathway is not viable. Additionally, some components in the stream are volatile at melter temperatures, thereby accumulating to high concentrations in the scrubbed stream. It would be highly beneficial to divert this stream to an alternate disposition path to alleviate the close-coupled operation of the LAW vitrification and Pretreatment facilities, and to improve long-term throughput and efficiency of the WTP system. In order to determine an alternate disposition path for the LAW SBS/WESP Recycle stream, a range of options are being studied. A simulant of the LAW Off-Gas Condensate was developed, based on the projected composition of this stream, and comparison with pilot-scale testing. The primary radionuclide that vaporizes and accumulates in the stream is Tc-99, but small amounts of several other radionuclides are also projected to be present in this stream. The processes being investigated for managing this stream includes evaporation and radionuclide removal via precipitation and adsorption. During evaporation, it is of interest to investigate the formation of insoluble solids to avoid scaling and plugging of equipment. Key parameters for radionuclide removal include identifying effective precipitation or ion

  19. Development And Initial Testing Of Off-Gas Recycle Liquid From The WTP Low Activity Waste Vitrification Process - 14333

    The Waste Treatment and Immobilization Plant (WTP) process flow was designed to pre-treat feed from the Hanford tank farms, separate it into a High Level Waste (HLW) and Low Activity Waste (LAW) fraction and vitrify each fraction in separate facilities. Vitrification of the waste generates an aqueous condensate stream from the off-gas processes. This stream originates from two off-gas treatment unit operations, the Submerged Bed Scrubber (SBS) and the Wet Electrospray Precipitator (WESP). Currently, the baseline plan for disposition of the stream from the LAW melter is to recycle it to the Pretreatment facility where it gets evaporated and processed into the LAW melter again. If the Pretreatment facility is not available, the baseline disposition pathway is not viable. Additionally, some components in the stream are volatile at melter temperatures, thereby accumulating to high concentrations in the scrubbed stream. It would be highly beneficial to divert this stream to an alternate disposition path to alleviate the close-coupled operation of the LAW vitrification and Pretreatment facilities, and to improve long-term throughput and efficiency of the WTP system. In order to determine an alternate disposition path for the LAW SBS/WESP Recycle stream, a range of options are being studied. A simulant of the LAW Off-Gas Condensate was developed, based on the projected composition of this stream, and comparison with pilot-scale testing. The primary radionuclide that vaporizes and accumulates in the stream is Tc-99, but small amounts of several other radionuclides are also projected to be present in this stream. The processes being investigated for managing this stream includes evaporation and radionuclide removal via precipitation and adsorption. During evaporation, it is of interest to investigate the formation of insoluble solids to avoid scaling and plugging of equipment. Key parameters for radionuclide removal include identifying effective precipitation or ion

  20. Soil Contamination due to E-Waste Disposal and Recycling Activities: A Review with Special Focus on China

    ZHANG Wei-Hua; WU Ying-Xin; M. O. SIMONNOT

    2012-01-01

    This paper presents a review of soil contamination resulting from e-waste recycling activities,with a special focus on China,where many data have been collected for a decade.Soils in the e-waste areas are often contaminated by heavy metals and organic compounds,mainly polycyclic aromatic hydrocarbons (PAHs),polybrominated diphenyl ethers (PBDEs),polychlorinated and polybrominated biphenyls (PCBs and PBBs),dechlorane plus (DP),hexabromocyclododecanes (HBCDs),polychlorinated and polybrominated dibenzop-dioxins (PCDDs and PBDDs),and polychlorinated and polybrominated dibenzofurans (PCDFs and PBDFs),while other compounds,not systematically monitored,can be found as well Pollutants are generally present in mixtures,so pollution situations are complex and diversified with a gradient of contamination from agricultural soils to hot spots at e-waste sites and mainly in open burning areas.It has been proved that pollutants were transferred to the food chain via rice in China,and that the population was threatened since high levels of various pollutants were detected in blood,placentas,hair,etc.,of residents of e-waste sites.Eventually,soil remediation techniques are reviewed.Although there are many available techniques devoted to heavy metals and persistent organic pollutants,the current techniques for the e-waste sites,where these contaminants coexist,are very sparse.Phytoremediation has been investigated and co-cropping appears as a promising approach for the slightly contaminated agricultural soils.In some cases,different remediation techniques should be combined or trained,while the influence of coexisting contaminants and the removal sequence of contaminants should be considered.In hot spots,physical and chemical techniques should be used to reduce high pollution levels to prevent further pollutant dissemination.This review highlights the urgent needs for 1) characterization of pollution status in all the countries where e-wastes are recycled,2) research on fate and

  1. Chloride/formate exchange with formic acid recycling: a mechanism of active chloride transport across epithelial membranes

    The pathways for transport of Cl- and formate in microvillus membrane vesicles isolated from rabbit renal cortex were evaluated. An outward formate gradient stimulated the uptake of 36Cl-, and an outward 36Cl- gradient stimulated the uptake of formate, indicating Cl-/formate exchange. In addition, an inside alkaline pH gradient induced the accumulation of formate, consistent with nonionic diffusion of formic acid. Although an inward Na+ gradient also stimulated uphill formate accumulation, this effect was abolished when ionophores were used to prevent the generation of a transmembrane pH gradient. An inside alkaline pH gradient only minimally stimulated the uptake of 82Br-, used as tracer for Cl-, confirming the absence of appreciable Cl-/OH- exchange. However, the same pH gradient in the presence of a physiologic formate concentration (0.2 mM) markedly stimulated 82Br- influx. These data suggest that Cl-/formate exchange with recycling of formic acid by nonionic diffusion is a potential mechanism for active Cl- absorption across the luminal membrane in the proximal tubule and perhaps in other epithelia

  2. Nanodomains in biomembranes with recycling

    Berger, Mareike; Destainville, Nicolas

    2016-01-01

    Cell membranes are out of thermodynamic equilibrium notably because of membrane recycling, i.e. active exchange of material with the cytosol. We propose an analytically tractable model of biomembrane predicting the effects of recycling on the size of protein nanodomains. It includes a short-range attraction between proteins and a weaker long-range repulsion which ensures the existence of so-called cluster phases at equilibrium, where monomeric proteins coexist with finite-size domains. Our main finding is that when taking recycling into account, the typical cluster size increases logarithmically with the recycling rate. Using physically realistic model parameters, the predicted two-fold increase due to recycling in living cells is very likely experimentally measurable with the help of super-resolution microscopy.

  3. Facile synthesis, structure and visible light photocatalytic activity of recyclable ZnFe2O4/TiO2

    Graphical abstract: - Highlights: • ZnFe2O4/TiO2 heterojunction was facilely synthesized by a solution combustion method. • Sponge-like ZnFe2O4/TiO2 shows excellent photocatalytic activity and stability. • The structure-to-activity relationship and photocatalytic mechanism were proposed. - Abstract: A kind of sponge-like ZnFe2O4/TiO2 composite was facilely synthesized by a solution combustion method. The physicochemical properties, including the crystalline phase, surface morphology, spectral response, photogenerated charge carriers’ separation and transfer efficiency, were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, N2 adsorption/desorption isotherms, X-ray photoelectron spectroscopy, UV–vis absorption spectroscopy and photoluminescence spectroscopy techniques and analyzed to interpret the relationship between the structure and photocatalytic activity. The sponge-like morphology promotes the adsorption of reaction species as well as functions as a good light harvesting structure for the enhancement of spectral utilization. The heterojunction effectively inhibited the recombination of photogenerated charge carriers. With these synergistic effects, the degradation rate of methylene blue on ZnFe2O4/TiO2 was up to 93.2% under visible light irradiation and remained stable even after five consecutive reaction runs. Moreover, owing to the magnetic property, ZnFe2O4/TiO2 can be recycled easily. Additionally, a photocatalytic mechanism of ZnFe2O4/TiO2 was proposed

  4. Activity of hydrogen in metal-hydrogen systems: strontium, thorium-nitrogen, and vanadium alloys

    The dissolution of H gas has been studied using pressure-composition isotherms in Sr, Th-N and V alloys containing either Nb, Cr or Ti. Direct H equilibrium vapor pressure measurements were performed in the Sr-H and Th-N-H systems at 973 to 11730K and 623 to 11230K, respectively. Isopiestic solubility was used to measure the H equilibrium pressures for the V alloys at 223 to 4730K. In all the alloys studied, the reaction of hydrogen with the metal phase was exothermic and hydrogen followed Sieverts' law over a considerable range of hydrogen concentration. The enthalpy of solution of H in the Sr and the enthalpy of formation of ThNH/sub x/ are -14.3 +- 1.2 kcal;/mol H and -16.3 +- 1.5 kcal/mol H2, respectively. Enthalpies of solution of H for the V alloys ranged from -8.0 to -10.5 +- 0.3 kcal/mol H. Additions of T to V dramatically enhanced the isopiestic solubility of H, Cr significantly reduced the solubility and Nb moderately increased the solubility. Sieverts' law behavior for H in the V alloys showed that substitutional atoms did not act as deep traps for H

  5. Two step novel hydrogen system using additives to enhance hydrogen release from the hydrolysis of alane and activated aluminum

    Zidan, Ragaiy; Teprovich, Joseph A.; Motyka, Theodore

    2015-12-01

    A system for the generation of hydrogen for use in portable power systems is set forth utilizing a two-step process that involves the thermal decomposition of AlH.sub.3 (10 wt % H.sub.2) followed by the hydrolysis of the activated aluminum (Al*) byproduct to release additional H.sub.2. Additionally, a process in which water is added directly without prior history to the AlH.sub.3:PA composite is also disclosed.

  6. Analysis of near-term production and market opportunities for hydrogen and related activities

    Mauro, R.; Leach, S. [National Hydrogen Association, Washington, DC (United States)

    1995-09-01

    This paper summarizes current and planned activities in the areas of hydrogen production and use, near-term venture opportunities, and codes and standards. The rationale for these efforts is to assess industry interest and engage in activities that move hydrogen technologies down the path to commercialization. Some of the work presented in this document is a condensed, preliminary version of reports being prepared under the DOE/NREL contract. In addition, the NHA work funded by Westinghouse Savannah River Corporation (WSRC) to explore the opportunities and industry interest in a Hydrogen Research Center is briefly described. Finally, the planned support of and industry input to the Hydrogen Technical Advisory Panel (HTAP) on hydrogen demonstration projects is discussed.

  7. Cryogenic hydrogen-induced air liquefaction technologies

    Escher, William J. D.

    1990-01-01

    Extensively utilizing a special advanced airbreathing propulsion archives database, as well as direct contacts with individuals who were active in the field in previous years, a technical assessment of cryogenic hydrogen-induced air liquefaction, as a prospective onboard aerospace vehicle process, was performed and documented. The resulting assessment report is summarized. Technical findings are presented relating the status of air liquefaction technology, both as a singular technical area, and also that of a cluster of collateral technical areas including: compact lightweight cryogenic heat exchangers; heat exchanger atmospheric constituents fouling alleviation; para/ortho hydrogen shift conversion catalysts; hydrogen turbine expanders, cryogenic air compressors and liquid air pumps; hydrogen recycling using slush hydrogen as heat sink; liquid hydrogen/liquid air rocket-type combustion devices; air collection and enrichment systems (ACES); and technically related engine concepts.

  8. Highly active, recyclable catalyst for the manufacture of viscous, low molecular weight, CO–ethene–propene-based polyketone, base component for a new class of resins

    Broekhuis, Antonius A.; Dirkzwager, Hendrik; Mul, Wilhelmus P.; Heeres, Hero J.; Linden, Adrianus J. van der; Orpen, A. Guy

    2002-01-01

    A highly active, recyclable homogeneous palladium(II) catalyst is described for the manufacture of viscous, low molecular weight CO–ethene–propene-based polyketone (Carilite Oligomer), used for the manufacture of a new class of resins (Carilite Resins). The catalyst is composed of palladium acetate, and a sulfonated diphosphine ligand, bdompp-S (1,3-bis(di-(2-methoxy, 5-sulfonatophenyl)phosphino)propane). In comparison with its non-sulfonated counterpart this catalyst not only exhibits a much...

  9. RECYCLING PHOSPHORUS SLAG AS A PRECURSOR FOR ALKALI-ACTIVATED BINDER; IMPACT OF TYPE AND DOSAGE OF ACTIVATOR

    Hojjatollah Maghsoodloorad; Hamidreza Khalili Amiri; Allahverdi Ali; Lachemi Mohamed; Hossain Khandaker M. Anwar

    2014-01-01

    The objectives of this study were to investigate the suitability of phosphorus slag as a precursor for alkali-activated binder by studying the effects of type and dosage of alkaline activators on compressive strength and efflorescence formation of the material. Different alkaline activators including; potassium hydroxide, sodium hydroxide, sodium carbonate, calcium hydroxide, and their combinations with liquid sodium silicate were used. Different levels of total alkali content (1, 3,...

  10. Hydrogen and fuel cell activity report - France 2009; Rapport d'activites Hydrogene et Piles a combustible - France 2009

    NONE

    2009-07-01

    The report gathers the main outstanding facts which occurred in France in the field of hydrogen and fuel cells in 2009. After having noticed some initiatives (French commitment in renewable energy production, new role for the CEA, cooperation between different research and industrial bodies, development of electric vehicles, research programs), the report presents several projects and programs regarding hydrogen: ANR programs, creation of a national structure, basic research by the CEA and CNRS, demonstration projects (H2E), transport applications (a hybrid 307 by Peugeot, the Althytude project by GDF and Suez, the Hychain European project by Air Liquide, a dirigible airship, an ultra-light aviation project, a submarine), some stationary applications (the Myrte project, a wind energy project), activity in small and medium-sized enterprises, regional initiatives, colloquiums and meetings.

  11. Gamma irradiation induced disintegration of waste activated sludge for biological hydrogen production

    Yin, Yanan; Wang, Jianlong

    2016-04-01

    In this paper, gamma irradiation was applied for the disintegration and dissolution of waste activated sludge produced during the biological wastewater treatment, and the solubilized sludge was used as substrate for bio-hydrogen production. The experimental results showed that the solubilization of waste activated sludge was 53.7% at 20 kGy and pH=12, and the SCOD, polysaccharides, protein, TN and TP contents in the irradiated sludge solutions was 3789.6 mg/L, 268.3 mg/L, 1881.5 mg/L, 132.3 mg/L and 80.4 mg/L, respectively. The irradiated sludge was used for fermentative hydrogen production, and the hydrogen yield was 10.5±0.7 mL/g SCODconsumed. It can be concluded that the irradiated waste activated sludge could be used as a low-cost substrate for fermentative hydrogen production.

  12. Partially Hydrogenated Graphene Materials Exhibit High Electrocatalytic Activities Related to Unintentional Doping with Metallic Impurities.

    Jankovský, Ondřej; Libánská, Alena; Bouša, Daniel; Sedmidubský, David; Matějková, Stanislava; Sofer, Zdeněk

    2016-06-13

    Partially hydrogenated graphene materials, synthesized by the chemical reduction/hydrogenation of two different graphene oxides using zinc powder in acidic environment or aluminum powder in alkaline environment, exhibit high electrocatalytic activities, as well as electrochemical sensing properties. The starting graphene oxides and the resultant hydrogenated graphenes were characterized in detail. Their electrocatalytic activity was examined in the oxygen reduction reaction, whereas sensing properties towards explosives were tested by using picric acid as a redox probe. Findings indicate that the high electrocatalytic performance originates not only from the hydrogenation of graphene, but also from unintentional contamination of graphene with manganese and other metals during synthesis. A careful evaluation of the obtained data and a detailed chemical analysis are necessary to identify the origin of this anomalous electrocatalytic activity. PMID:27167069

  13. Quantum delocalization of protons in the hydrogen bond network of an enzyme active site

    Wang, Lu; Boxer, Steven G; Markland, Thomas E

    2015-01-01

    Enzymes utilize protein architectures to create highly specialized structural motifs that can greatly enhance the rates of complex chemical transformations. Here we use experiments, combined with ab initio simulations that exactly include nuclear quantum effects, to show that a triad of strongly hydrogen bonded tyrosine residues within the active site of the enzyme ketosteroid isomerase (KSI) facilitates quantum proton delocalization. This delocalization dramatically stabilizes the deprotonation of an active site tyrosine residue, resulting in a very large isotope effect on its acidity. When an intermediate analog is docked, it is incorporated into the hydrogen bond network, giving rise to extended quantum proton delocalization in the active site. These results shed light on the role of nuclear quantum effects in the hydrogen bond network that stabilizes the reactive intermediate of KSI, and the behavior of protons in biological systems containing strong hydrogen bonds.

  14. Swiss Hydrogen & Fuel Cell Activities : Opportunities, barriers and public support

    Vuille, François; Hart, David; Lehner, Franz; Bertuccioli, Luca; Ripken, Ralph

    2014-01-01

    Switzerland has a small but internationally recognised set of competences and actors in fuel cells and hydrogen, from fundamental research to technology and product development. Swiss organisations are prominent in a number of research partnerships, and some have either major international co-operation or are partly or fully owned by overseas companies. However, the sector in Switzerland remains somewhat fragmented, with many actors pursuing their own niches and relatively little cross-fertil...

  15. Effects of thermal activation conditions on the microstructure regulation of corncob-derived activated carbon for hydrogen storage

    Dabin Wang; Zhen Geng; Cunman Zhang; Xiangyang Zhou; Xupeng Liu

    2014-01-01

    Activated carbons derived from corncob (CACs) were prepared by pyrolysis carbonization and KOH activation. Through modifying activation conditions, samples with large pore volume and ultrahigh BET specific surface area could be obtained. The sample achieved the highest hydrogen uptake capacity of 5.80 wt%at 40 bar and -196◦C. The as-obtained samples were characterized by N2-sorption, transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Besides, thermogravimetric analysis was also employed to investigate the activation behavior of CACs. Detailed investigation on the activation parameters reveals that moderate activation temperature and heating rate are favorable for preparing CACs with high surface area, large pore volume and optimal pore size distribution. Meanwhile, the micropore volume between 0.65 nm and 0.85 nm along with BET surface area and total pore volume has great effects on hydrogen uptake capacities. The present results indicate that CACs are the most promising materials for hydrogen storage application.

  16. 循环氢压机42CrMo合金钢活塞杆腐蚀失效剖析%Analysis of Corrosion Failure of 42CrMo Alloy Steel Piston Rod in Recycle Hydrogen Compressor

    梁成浩; 隋永强; 王树森

    2011-01-01

    通过对石蜡加氢装置3号循环氢压机42CrMo合金钢活塞杆腐蚀产物进行物理测试,考察了腐蚀原因。结果表明,石蜡加氢装置3号循环氢压机活塞杆腐蚀的原因是氢气介质冲击腐蚀与硫化氢介质的腐蚀联合作用所致。即活塞杆在氢气介质中高速运转时,由于旋转力矩形态的不断变化产生湍流作用,使镀铬层表面形成强烈的冲击腐蚀,导致Cr镀层及Cr的氧化层腐蚀剥落。42CrMo合金钢活塞杆裸露处与S^2-反应生成FeS,引起硫化氢腐蚀。活塞杆表面腐蚀产物主要由Fe—Cr相、FeCr2O4,Fe3O4的铁、铬氧化合物和FeS的铁的硫化物等组成。%The causes of corrosion were investigated by physical tests on corrosion products of 42CrMo alloy steel piston rod in the 3 # recycle hydrogen compressor of paraffin hydrogenation unit. The results showed that the corrosion was caused by combination effect of hydrogen medium impingement corrosion and hydrogen sulfide corrosion. When the piston rod rotated at a high speed in hydrogen medium, the form of rotating torque changed uninterruptedly to make turbulence influences, which produced a strong impingement attack on plating chromic surface, resulting in corrosion spalling between Cr plating surface and Cr oxidation layer. Exposed surface of 42CrMo alloy steel piston rod reacted with S^2- , forming FeS, which caused hydrogen sulfide corrosion. Corrosion products in piston rod surface were mainly made by Fe - Cr phase, iron and chromium oxygen compounds, Iron sulfides etc.

  17. Ford/BASF/UM Activities in Support of the Hydrogen Storage Engineering Center of Excellence

    Veenstra, Mike [Ford Motor Company, Dearborn, MI (United States); Purewal, Justin [Ford Motor Company, Dearborn, MI (United States); Xu, Chunchuan [Ford Motor Company, Dearborn, MI (United States); Yang, Jun [Ford Motor Company, Dearborn, MI (United States); Blaser, Rachel [Ford Motor Company, Dearborn, MI (United States); Sudik, Andrea [Ford Motor Company, Dearborn, MI (United States); Siegel, Don [Univ. of Michigan, Ann Arbor, MI (United States); Ming, Yang [Univ. of Michigan, Ann Arbor, MI (United States); Liu, Dong' an [Univ. of Michigan, Ann Arbor, MI (United States); Chi, Hang [Univ. of Michigan, Ann Arbor, MI (United States); Gaab, Manuela [BASF SE, Ludwigshafen (Germany); Arnold, Lena [BASF SE, Ludwigshafen (Germany); Muller, Ulrich [BASF SE, Ludwigshafen (Germany)

    2015-06-30

    revealed cost gaps and opportunities that identified a storage system that was lower cost than a 700 bar compressed system. Finally, we led the HSECoE efforts devoted to characterizing and enhancing metal organic framework (MOF) storage materials. This report serves as a final documentation of the Ford-UM-BASF project contributions to the HSECoE during the 6-year timeframe of the Center. The activities of the HSECoE have impacted the broader goals of the DOE-EERE and USDRIVE, leading to improved understanding in the engineering of materials-based hydrogen storage systems. This knowledge is a prerequisite to the development of a commercially-viable hydrogen storage system.

  18. Activated carbons from African oil palm waste shells and fibre for hydrogen storage

    Liliana Giraldo

    2013-06-01

    Full Text Available We prepared a series of activated carbons by chemical activation with two strong bases in-group that few use, and I with waste from shell and fibers and oil-palm African. Activated carbons are obtained with relatively high surface areas (1605 m2/g. We study the textural and chemical properties and its effect on hydrogen storage. The activated carbons obtained from fibrous wastes exhibit a high hydrogen storage capacity of 6.0 wt % at 77 K and 12 bar.

  19. Recycling Facilities - Land Recycling Cleanup Locations

    NSGIC GIS Inventory (aka Ramona) — Land Recycling Cleanup Location Land Recycling Cleanup Locations (LRCL) are divided into one or more sub-facilities categorized as media: Air, Contained Release or...

  20. Hydrogen behaviour in the aged low activation martensitic steel F82H for fusion reactor applications

    A time dependent permeation method is used to measure the permeability, diffusivity and solubility of hydrogen in the low activation martensitic steel F82H aged for 2000 h under vacuum at 773 K. The measurements cover the temperature range from 373 to 723 K which includes the onset of hydrogen trapping effects on diffusivity and solubility. The results are interpreted using a trapping model. The number of trap sites and their average energies for hydrogen in the aged F82H steel are determined. These data are compared with those obtained for deuterium in F82H steel

  1. Surface adsorption and micropore filling of the hydrogen in activated MWCNTs

    Rather, Sami-ullah; Zacharia, Renju; Naik, Meraj-ud-din; Hwang, Sang Woon [School of Chemical Engineering and Technology, Chonbuk National University, Chonju 561-756 (Korea); Kim, Ae Rahn [Specialized Graduate School of Hydrogen and Fuel Cells, Chonbuk National University, Chonju 561-756 (Korea); Nahm, Kee Suk [School of Chemical Engineering and Technology, Chonbuk National University, Chonju 561-756 (Korea); Specialized Graduate School of Hydrogen and Fuel Cells, Chonbuk National University, Chonju 561-756 (Korea)

    2008-11-15

    Hydrogen uptake of KOH-activated MWCNTs measured at ambient temperature and moderate equilibrium pressures ranging 0.3-1.9 MPa is compared with that of the pristine nanotubes. In the pressure range considered, the hydrogen uptake of nanotubes stems from micropore volume filling and adsorption on the external and the mesoporous surfaces. Pristine nanotubes store 0.2 wt.% of hydrogen which increases to 0.32 wt.% upon activation, corresponding to an enhancement of 60%. The pore width in the micropore region derived using the Horvath-Kawazoe equation suggests no widening of micropores. The contributions of hydrogen adsorbed on the meso- and micropores are resolved by applying the Langmuir kinetics to the external surface and micropore surface areas and micropore volume; the latter are derived from BET, Dubinin-Astakhov, and Lippen's-de Boer's t-plot analysis. (author)

  2. Effect of polyhydroxyalkanoates on dark fermentative hydrogen production from waste activated sludge.

    Wang, Dongbo; Zeng, Guangming; Chen, Yinguang; Li, Xiaoming

    2015-04-15

    Polyhydroxyalkanoates (PHA), an intracellular energy and carbon storage polymer, can be accumulated in activated sludge in substantial quantities under wastewater dynamic treatment (i.e., substrate feast-famine) conditions. However, its influence on hydrogen production has never been investigated before. This study therefore evaluated the influences of PHA level and composition in waste activated sludge (WAS) on hydrogen production. The results showed that with the increase of sludge PHA content from 25 to 178 mg per gram volatile suspended solids (VSS) hydrogen production from WAS alkaline anaerobic fermentation increased from 26.5 to 58.7 mL/g VSS. The composition of PHA was also found to affect hydrogen production. When the dominant composition shifted from polyhydroxybutyrate (PHB) to polyhydroxyvalerate (PHV), the amount of generated hydrogen decreased from 51.2 to 41.1 mL/g VSS even under the same PHA level (around 130 mg/g VSS). The mechanism studies exhibited that the increased PHA content accelerated both the cell solubilization and the hydrolysis process of solubilized substrates. Compared with the PHB-dominant sludge, the increased PHV fraction not only slowed the hydrolysis process but also caused more propionic acid production, with less theoretical hydrogen generation in this fermentation type. It was also found that the increased PHA content enhanced the soluble protein conversion of non-PHA biomass. Further investigations with enzyme analyses showed that both the key hydrolytic enzyme activities and hydrogen-forming enzyme activities were in the sequence of the PHB-dominant sludge > the PHV-dominant sludge > the low PHA sludge, which was in accord with the observed order of hydrogen yield. PMID:25697693

  3. Identification of intrinsic catalytic activity for electrochemical reduction of water molecules to generate hydrogen

    Shinagawa, Tatsuya

    2015-01-01

    Insufficient hydronium ion activities at near-neutral pH and under unbuffered conditions induce diffusion-limited currents for hydrogen evolution, followed by a reaction with water molecules to generate hydrogen at elevated potentials. The observed constant current behaviors at near neutral pH reflect the intrinsic electrocatalytic reactivity of the metal electrodes for water reduction. This journal is © the Owner Societies.

  4. The GTPase-Activating Enzyme Gyp1p Is Required for Recycling of Internalized Membrane Material by Inactivation of the Rab/Ypt GTPase Ypt1p

    Lafourcade, Céline; Galan, Jean-Marc; Gloor, Yvonne; Haguenauer-Tsapis, Rosine; Peter, Matthias

    2004-01-01

    Rab/Ypt GTPases are key regulators of membrane trafficking and together with SNARE proteins mediate selective fusion of vesicles with target compartments. A family of GTPase-activating enzymes (GAPs) specific for Rab/Ypt GTPases has been discovered, but little is known about their function and substrate specificity in vivo. Here we show that the GAP activity of Gyp1p, a yeast member of this family, is specifically required for recycling of the SNARE Snc1p and the membrane dye FM4-64, implying...

  5. The size of active bubbles for the production of hydrogen in sonochemical reaction field.

    Merouani, Slimane; Hamdaoui, Oualid

    2016-09-01

    The sonication of aqueous solution generates microscopic cavitation bubbles that may growth and violently collapse to produce highly reactive species (i.e. OH, HO2 and H2O2), hydrogen and emit light, sonoluminescence. The bubble size is a key parameter that influences the chemical activity of the system. This wok aims to study theoretically the size of active bubbles for the production of hydrogen in ultrasonic cavitation field in water using a single bubble sonochemistry model. The effect of several parameters such as frequency of ultrasound, acoustic intensity and liquid temperature on the range of sonochemically active bubbles for the production of hydrogen was clarified. The numerical simulation results showed that the size of active bubbles is an interval which includes an optimum value at which the production rate of H2 is maximal. It was shown that the range of ambient radius for an active bubble as well as the optimum bubble radius for the production of hydrogen increased with increasing acoustic intensity and decreased with increasing ultrasound frequency and bulk liquid temperature. It was found that the range of ambient bubble radius dependence of the operational conditions followed the same trend as those reported experimentally for sonoluminescing bubbles. Comparison with literature data showed a good agreement between the theoretical determined optimum bubble sizes for the production of hydrogen and the experimental reported sizes for sonoluminescing bubbles. PMID:27150777

  6. Determination of hydrogen in niobium by cold neutron prompt gamma ray activation analysis and neutron incoherent scattering

    R.L. Paul; H.H. Cheu-Maya; G.R. Myneni

    2002-11-01

    The presence of trace amounts of hydrogen in niobium is believed to have a detrimental effect on the mechanical and superconducting properties. Unfortunately, few techniques are capable of measuring hydrogen at these levels. We have developed two techniques for measuring hydrogen in materials. Cold neutron prompt gamma-ray activation analysis (PGAA) has proven useful for the determination of hydrogen and other elements in a wide variety of materials. Neutron incoherent scattering (NIS), a complementary tool to PGAA, has been used to measure trace hydrogen in titanium. Both techniques were used to study the effects of vacuum heating and chemical polishing on the hydrogen content of superconducting niobium.

  7. Cost effectiveness of recycling: A systems model

    Highlights: • Curbside collection of recyclables reduces overall system costs over a range of conditions. • When avoided costs for recyclables are large, even high collection costs are supported. • When avoided costs for recyclables are not great, there are reduced opportunities for savings. • For common waste compositions, maximizing curbside recyclables collection always saves money. - Abstract: Financial analytical models of waste management systems have often found that recycling costs exceed direct benefits, and in order to economically justify recycling activities, externalities such as household expenses or environmental impacts must be invoked. Certain more empirically based studies have also found that recycling is more expensive than disposal. Other work, both through models and surveys, have found differently. Here we present an empirical systems model, largely drawn from a suburban Long Island municipality. The model accounts for changes in distribution of effort as recycling tonnages displace disposal tonnages, and the seven different cases examined all show that curbside collection programs that manage up to between 31% and 37% of the waste stream should result in overall system savings. These savings accrue partially because of assumed cost differences in tip fees for recyclables and disposed wastes, and also because recycling can result in a more efficient, cost-effective collection program. These results imply that increases in recycling are justifiable due to cost-savings alone, not on more difficult to measure factors that may not impact program budgets

  8. COPPER CABLE RECYCLING TECHNOLOGY

    The United States Department of Energy (DOE) continually seeks safer and more cost-effective technologies for use in deactivation and decommissioning (D and D) of nuclear facilities. The Deactivation and Decommissioning Focus Area (DDFA) of the DOE's Office of Science and Technology (OST) sponsors large-scale demonstration and deployment projects (LSDDPs). At these LSDDPs, developers and vendors of improved or innovative technologies showcase products that are potentially beneficial to the DOE's projects and to others in the D and D community. Benefits sought include decreased health and safety risks to personnel and the environment, increased productivity, and decreased costs of operation. The Idaho National Engineering and Environmental Laboratory (INEEL) generated a list of statements defining specific needs and problems where improved technology could be incorporated into ongoing D and D tasks. One such need is to reduce the volume of waste copper wire and cable generated by D and D. Deactivation and decommissioning activities of nuclear facilities generates hundreds of tons of contaminated copper cable, which are sent to radioactive waste disposal sites. The Copper Cable Recycling Technology separates the clean copper from contaminated insulation and dust materials in these cables. The recovered copper can then be reclaimed and, more importantly, landfill disposal volumes can be reduced. The existing baseline technology for disposing radioactively contaminated cables is to package the cables in wooden storage boxes and dispose of the cables in radioactive waste disposal sites. The Copper Cable Recycling Technology is applicable to facility decommissioning projects at many Department of Energy (DOE) nuclear facilities and commercial nuclear power plants undergoing decommissioning activities. The INEEL Copper Cable Recycling Technology Demonstration investigated the effectiveness and efficiency to recycle 13.5 tons of copper cable. To determine the effectiveness

  9. Actinide recycle

    A multitude of studies and assessments of actinide partitioning and transmutation were carried out in the late 1970s and early 1980s. Probably the most comprehensive of these was a study coordinated by Oak Ridge National Laboratory. The conclusions of this study were that only rather weak economic and safety incentives existed for partitioning and transmuting the actinides for waste management purposes, due to the facts that (1) partitioning processes were complicated and expensive, and (2) the geologic repository was assumed to contain actinides for hundreds of thousands of years. Much has changed in the few years since then. A variety of developments now combine to warrant a renewed assessment of the actinide recycle. First of all, it has become increasingly difficult to provide to all parties the necessary assurance that the repository will contain essentially all radioactive materials until they have decayed. Assurance can almost certainly be provided to regulatory agencies by sound technical arguments, but it is difficult to convince the general public that the behavior of wastes stored in the ground can be modeled and predicted for even a few thousand years. From this point of view alone there would seem to be a clear benefit in reducing the long-term toxicity of the high-level wastes placed in the repository

  10. Recycling of electronic scrap

    Legarth, Jens Brøbech

    This Ph.D. thesis deals with the growingly important field of electronics recycling with special attention to the problem of printed circuit board recycling. A literature survey of contemporary electronics recycling and printed circuit board recycling is presented.Further, an analysis of the role...

  11. Green Science: Revisiting Recycling

    Palliser, Janna

    2011-01-01

    Recycling has been around for a long time--people have reused materials and refashioned them into needed items for thousands of years. More recently, war efforts encouraged conservation and reuse of materials, and in the 1970s recycling got its official start when recycling centers were created. Now, curbside recycling programs and recycling…

  12. A coupled, pore-scale model for methanogenic microbial activity in underground hydrogen storage

    Ebigbo, Anozie; Golfier, Fabrice; Quintard, Michel

    2013-11-01

    Underground hydrogen storage (UHS) as a means of energy storage is an efficient way of compensating for seasonal fluctuations in the availability of energy. One important factor which influences this technology is the activity of methanogenic microorganisms capable of utilising hydrogen and carbon dioxide for metabolism and leading to a change in the stored gas composition. A coupled, pore-scale model is presented which aids in the investigation of the mechanisms that govern the conversion of hydrogen to methane, i.e. advective hydrogen flow, its diffusion into microbial biofilms of multiple species, and its consumption within these biofilms. The model assumes that spherical grains are coated by a film of residual water and treats the biofilm development within each film in a quasi one-dimensional manner. A sample simulation using the presented model illustrates the biofilm growth process in these films as well as the competition between three different microbial species: methanogens, acetogens, and acetotrophs.

  13. Methanation process utilizing split cold gas recycle

    Tajbl, Daniel G.; Lee, Bernard S.; Schora, Jr., Frank C.; Lam, Henry W.

    1976-07-06

    In the methanation of feed gas comprising carbon monoxide and hydrogen in multiple stages, the feed gas, cold recycle gas and hot product gas is mixed in such proportions that the mixture is at a temperature sufficiently high to avoid carbonyl formation and to initiate the reaction and, so that upon complete reaction of the carbon monoxide and hydrogen, an excessive adiabatic temperature will not be reached. Catalyst damage by high or low temperatures is thereby avoided with a process that utilizes extraordinarily low recycle ratios and a minimum of investment in operating costs.

  14. Adsorption of triton X100 and potassium hydrogen phthalate on granular activated carbon from date pits

    Merzougui, Z.; Nedjah, S.; Azoudj, Y.; Addoun, F. [Laboratoire d' etude physic-chimique des materiaux et application a l' environnement, Faculte de Chimie, USTHB (Algeria)], E-mail: zmerzougi@yahoo.fr

    2011-07-01

    Activated carbons, thanks to their versatility, are being used in the water treatment sector to absorb pollutants. Several factors influence the adsorption capacity of activated carbon and the aim of this study was to assess the effects of the porous texture and chemical nature of activated carbons on the adsorption of triton X100 and potassium hydrogen phthalate. Activated carbons used in this study were prepared from date pits with ZnCl2, KOH and H3PO4 by carbonization without adjuvant and adsorption of triton X100 and potassium hydrogen phthalate was conducted at 298K. Results showed that activated carbons prepared from date pits have a great potential for removing organic and inorganic pollutants from water and that the adsorption potential depends on the degree of activation of the activated carbons and on the compounds to absorb. This study highlighted that an increase of the carbon surface area and porosity results in a better adsorption capacity.

  15. Nanoscale nickel oxide/nickel heterostructures for active hydrogen evolution electrocatalysis.

    Gong, Ming; Zhou, Wu; Tsai, Mon-Che; Zhou, Jigang; Guan, Mingyun; Lin, Meng-Chang; Zhang, Bo; Hu, Yongfeng; Wang, Di-Yan; Yang, Jiang; Pennycook, Stephen J; Hwang, Bing-Joe; Dai, Hongjie

    2014-01-01

    Active, stable and cost-effective electrocatalysts are a key to water splitting for hydrogen production through electrolysis or photoelectrochemistry. Here we report nanoscale nickel oxide/nickel heterostructures formed on carbon nanotube sidewalls as highly effective electrocatalysts for hydrogen evolution reaction with activity similar to platinum. Partially reduced nickel interfaced with nickel oxide results from thermal decomposition of nickel hydroxide precursors bonded to carbon nanotube sidewalls. The metal ion-carbon nanotube interactions impede complete reduction and Ostwald ripening of nickel species into the less hydrogen evolution reaction active pure nickel phase. A water electrolyzer that achieves ~20 mA cm(-2) at a voltage of 1.5 V, and which may be operated by a single-cell alkaline battery, is fabricated using cheap, non-precious metal-based electrocatalysts. PMID:25146255

  16. Thermally Activated Palm Kernel Based Carbon as a Support for Edible Oil Hydrogenation Catalyst

    Abdulmajid Alshaibani

    2013-01-01

    Full Text Available Activated carbon has distinctive properties as a support for hydrogenation catalysts. Thermally activated carbon has been prepared from palm kernel shell at 1073 K and placed under nitrogen flow for 2 h. It was impregnated by palladium using toluene solution of Pd (acac2. The Pd/C was reduced using a water solution of potassium borohydride (KBH4. The Pd-B/C was characterized by the Brunauer-Emmett-Teller surface area analysis (BET, scanning electron microscopy (SEM, transmission electron microscopy (TEM and inductively-coupled plasma mass spectrometry (ICP-MS. Pd-B/C was applied for sunflower oil hydrogenation at a temperature of 373 K, hydrogen pressure of 413.5 kPa and agitation of 1400 rpm for 1 h. Pd-B/C noticeably exhibited a higher overall catalyst activity in comparison to some recently published palladium catalysts.

  17. Proteasome Inhibition Triggers Activity-Dependent Increase in the Size of the Recycling Vesicle Pool in Cultured Hippocampal Neurons

    Willeumier, Kristen; Pulst, Stefan M.; Schweizer, Felix E.

    2006-01-01

    The ubiquitin proteasome system, generally known for its function in protein degradation, also appears to play an important role in regulating membrane trafficking. A role for the proteasome in regulating presynaptic release and vesicle trafficking has been proposed for invertebrates, but it remains to be tested in mammalian presynaptic terminals. We used the fluorescent styrylpyridinium dye FM4-64 to visualize changes in the recycling pool of vesicles in hippocampal culture under pharmacolog...

  18. Activity and Stability of Rare Earth-Based Hydride Alloys as Catalysts of Hydrogen Absorption-Oxidation Reactions

    Ying Taokai(应桃开); Gao Xueping(高学平); Hu Weikang(胡伟康); Noréus Dag

    2004-01-01

    Rare earth-based AB5-type hydrogen storage alloys as catalysts of hydrogen-diffusion electrodes for hydrogen absorption and oxidation reactions in alkaline fuel cells were investigated. It is demonstrated that the meta-hydride hydrogen-diffusion electrodes could be charged by hydrogen gas and electrochemically discharged at the same time to retain a stable oxidation potential for a long period. The catalytic activities and stability are almost comparable with a Pt catalyst on the active carbon. Further improvement of performances is expected via reduction of catalyst size into nanometers.

  19. Solid waste recycling in Rajshahi city of Bangladesh.

    Bari, Q Hamidul; Hassan, K Mahbub; Haque, M Ehsanul

    2012-11-01

    Efficient recycling of solid wastes is now a global concern for a sustainable and environmentally sound management. In this study, traditional recycling pattern of solid waste was investigated in Rajshahi municipality which is the fourth largest city of Bangladesh. A questionnaire survey had been carried out in various recycle shops during April 2010 to January 2011. There were 140 recycle shops and most of them were located in the vicinity of Stadium market in Rajshahi. About 1906 people were found to be involved in recycling activities of the city. The major fraction of recycled wastes were sent to capital city Dhaka for further manufacture of different new products. Only a small amount of wastes, specially plastics, were processed in local recycle factories to produce small washing pots and bottle caps. Everyday, an estimated 28.13 tons of recycled solid wastes were handled in Rajshahi city area. This recycled portion accounted for 8.25% of the daily total generated wastes (341 ton d(-1)), 54.6% of total recyclable wastes (51.49 ton d(-1)) and 68.29% of readily recyclable wastes (41.19 ton d(-1)). Major recycled materials were found to be iron, glass, plastic, and papers. Only five factories were involved in preliminary processing of recyclable wastes. Collecting and processing secondary materials, manufacturing recycled-content products, and then buying recycled products created a circle or loop that ensured the overall success of recycling and generated a host of financial, environmental, and social returns. PMID:22749721

  20. Hydrogen activities in the European Union work-programme; Activites liees a l'hydrogene dans le programme de travail de l'Union Europeenne

    Bahbout, A.; Tartaglia, G.P. [Joint Research Centre, IHCP, Ispra (Italy)

    2000-07-01

    Growing concern over urban air pollution, global climatic change allegedly caused by rising levels of greenhouse gases and future energy security requirements demand a solution: a clean and sustainable energy supply. Hydrogen is seen as a promising clean fuel when integrated into a wide and long-term vision in which it provides, in parallel with electricity, a secondary energy carrier, ultimately derived from renewable energy sources. Europe has been a pioneer in promoting the wider use of hydrogen. Already in 1991, various demonstration projects were started with funds under the Euro-Quebec Hydro-Hydrogen Pilot Project (EQHPP). The European Commission, the European Industry, the Government of Quebec and the Canadian Industry made resources available so that hydrogen, from surplus in Canada, could be applied in various end-use technologies. Under this project, about thirty European industry/research centres/universities have been involved, working on a comprehensive set of hydrogen applications/uses. Innovative public transportation means (city buses, boats) equipped with internal combustion engines (ICE) or fuel cells and using either liquid or compressed hydrogen were put into demonstration service. Cogeneration (CHP) projects based on the use of phosphoric acid fuel cells (PAFC) were realised. In joint programs, aviation combustor test activities were carried out by Daimler Benz Aerospace, Airbus Industries and Pratt and Whitney. Investigation of hydrogen storage in zeolites, carbon and nano-tubes were started. Tests on compressed hydrogen gas storage tanks were also conducted. All these projects are now terminated. As intended, the initial momentum set by the EQHPP project has now been replaced by many private initiatives, especially in Germany. Only one specific project funded by the European Commission, the European Integrated Hydrogen Project (EIHP) remains. In the EIHP project, several companies which designed and constructed prototypes and demonstration

  1. In situ hydrogen consumption kinetics as an indicator of subsurface microbial activity

    Harris, S.H.; Smith, R.L.; Suflita, J.M.

    2007-01-01

    There are few methods available for broadly assessing microbial community metabolism directly within a groundwater environment. In this study, hydrogen consumption rates were estimated from in situ injection/withdrawal tests conducted in two geochemically varying, contaminated aquifers as an approach towards developing such a method. The hydrogen consumption first-order rates varied from 0.002 nM h-1 for an uncontaminated, aerobic site to 2.5 nM h-1 for a contaminated site where sulfate reduction was a predominant process. The method could accommodate the over three orders of magnitude range in rates that existed between subsurface sites. In a denitrifying zone, the hydrogen consumption rate (0.02 nM h-1) was immediately abolished in the presence of air or an antibiotic mixture, suggesting that such measurements may also be sensitive to the effects of environmental perturbations on field microbial activities. Comparable laboratory determinations with sediment slurries exhibited hydrogen consumption kinetics that differed substantially from the field estimates. Because anaerobic degradation of organic matter relies on the rapid consumption of hydrogen and subsequent maintenance at low levels, such in situ measures of hydrogen turnover can serve as a key indicator of the functioning of microbial food webs and may be more reliable than laboratory determinations. ?? 2007 Federation of European Microbiological Societies.

  2. A rhodium/silicon co-electrocatalyst design concept to surpass platinum hydrogen evolution activity at high overpotentials.

    Zhu, Lili; Lin, Haiping; Li, Youyong; Liao, Fan; Lifshitz, Yeshayahu; Sheng, Minqi; Lee, Shuit-Tong; Shao, Mingwang

    2016-01-01

    Currently, platinum-based electrocatalysts show the best performance for hydrogen evolution. All hydrogen evolution reaction catalysts should however obey Sabatier's principle, that is, the adsorption energy of hydrogen to the catalyst surface should be neither too high nor too low to balance between hydrogen adsorption and desorption. To overcome the limitation of this principle, here we choose a composite (rhodium/silicon nanowire) catalyst, in which hydrogen adsorption occurs on rhodium with a large adsorption energy while hydrogen evolution occurs on silicon with a small adsorption energy. We show that the composite is stable with better hydrogen evolution activity than rhodium nanoparticles and even exceeding those of commercial platinum/carbon at high overpotentials. The results reveal that silicon plays a key role in the electrocatalysis. This work may thus open the door for the design and fabrication of electrocatalysts for high-efficiency electric energy to hydrogen energy conversion. PMID:27447292

  3. Kinetic reduction of mill scale via hydrogen

    Gaballah N.M.

    2014-01-01

    Full Text Available Mill scale is very attractive industrial waste since it is rich in iron (about = 72 % Fe and it is suiTab. for direct recycling to the blast furnace via sintering plant. In this paper the characterizations of raw materials were studied by different methods of analyses. The produced briquettes were reduced with different amounts of hydrogen at varying temperatures, and the reduction kinetics was determined. Two models were applied and the energy of activation was calculated.

  4. 78 FR 20640 - Polychlorinated Biphenyls (PCBs); Recycling Plastics from Shredder Residue

    2013-04-05

    ... Residue (77 FR 74006). Additional background information on recycling activities that would be affected by... AGENCY Polychlorinated Biphenyls (PCBs); Recycling Plastics from Shredder Residue AGENCY: Environmental... will generally allow for the recycling of plastic separated from shredder residue under the...

  5. Highly Active Carbon Supported Pd-Ag Nanofacets Catalysts for Hydrogen Production from HCOOH.

    Wang, Wenhui; He, Ting; Liu, Xuehua; He, Weina; Cong, Hengjiang; Shen, Yangbin; Yan, Liuming; Zhang, Xuetong; Zhang, Jinping; Zhou, Xiaochun

    2016-08-17

    Hydrogen is regarded as a future sustainable and clean energy carrier. Formic acid is a safe and sustainable hydrogen storage medium with many advantages, including high hydrogen content, nontoxicity, and low cost. In this work, a series of highly active catalysts for hydrogen production from formic acid are successfully synthesized by controllably depositing Pd onto Ag nanoplates with different Ag nanofacets, such as Ag{111}, Ag{100}, and the nanofacet on hexagonal close packing Ag crystal (Ag{hcp}). Then, the Pd-Ag nanoplate catalysts are supported on Vulcan XC-72 carbon black to prevent the aggregation of the catalysts. The research reveals that the high activity is attributed to the formation of Pd-Ag alloy nanofacets, such as Pd-Ag{111}, Pd-Ag{100}, and Pd-Ag{hcp}. The activity order of these Pd-decorated Ag nanofacets is Pd-Ag{hcp} > Pd-Ag{111} > Pd-Ag{100}. Particularly, the activity of Pd-Ag{hcp} is up to an extremely high value, i.e., TOF{hcp} = 19 000 ± 1630 h(-1) at 90 °C (lower limit value), which is more than 800 times higher than our previous quasi-spherical Pd-Ag alloy nanocatalyst. The initial activity of Pd-Ag{hcp} even reaches (3.13 ± 0.19) × 10(6) h(-1) at 90 °C. This research not only presents highly active catalysts for hydrogen generation but also shows that the facet on the hcp Ag crystal can act as a potentially highly active catalyst. PMID:27454194

  6. Prediction of activation energies for hydrogen abstraction by cytochrome p450

    Olsen, Lars; Rydberg, Patrik; Rod, Thomas Holm; Ryde, Ulf

    2006-01-01

    We have estimated the activation energy for hydrogen abstraction by compound I in cytochrome P450 for a diverse set of 24 small organic substrates using state-of-the-art density functional theory (B3LYP). We then show that these results can be reproduced by computationally less demanding methods...

  7. Activity of iridium-ruthenium and iridium-rhodium adsorption catalysts in decomposition of hydrogen peroxide

    Experimental data for the activities of iridium-ruthenium and iridium-rhodium adsorption catalysts in the decomposition of hydrogen peroxide are considered and the results of magnetic susceptibility measurements are presented. It is concluded that surface structures (complexes) may be formed and that micro-electronic feaures play a role in heterogeneous catalysis

  8. Effects of Iron on Hydrogen-producing Capacity,Hydrogenase and NADH-fd Reductase Activities of a Fermentative Hydrogen-producing Bacterial Strain B49

    Wang Xiangjing(王相晶); Ren Nanqi; Xiang Wensheng

    2004-01-01

    Iron plays an important role in hydrogen production, cell growth, hydrogenase and NADH-fd reductase activities of hydrogen-producing bacterial strain B49 (AF481148 in EMBL). At the end of fermentation from 10 g/L glucose, for the culture containing 10 mg/L FeSO4*7H2O the cell growth in terms of optical density (OD) at 600nm was 1.13, the ratio of ethanol amount (mg/L) to acetate amount (mg/L) was 1.55, and the accumulated hydrogen volume was 1816.3 ml H2/L culture; whereas for the culture of 80 mg/L FeSO4*7H2O OD600nm was increased to 1.34, the accumulated hydrogen volume was increased to 2360.5 ml H2/L culture, and the ratio of ethanol amount (mg/L) to acetate amount (mg/L) decreased to 1.31. Moreover, the iron addition to the medium at different fermentation time could affect hydrogen-producing ability. However, the later the addition time of FeSO4*7H2O was postponed, the less the effect on hydrogen evolution was. In the course of fermentation, the specific activities of hydrogenase and NADH-fd reductase of hydrogen-producing bacterial strain B49 decreased with the consumption of iron.

  9. Hydrogen program overview

    Gronich, S. [Dept. of Energy, Washington, DC (United States). Office of Utility Technologies

    1997-12-31

    This paper consists of viewgraphs which summarize the following: Hydrogen program structure; Goals for hydrogen production research; Goals for hydrogen storage and utilization research; Technology validation; DOE technology validation activities supporting hydrogen pathways; Near-term opportunities for hydrogen; Market for hydrogen; and List of solicitation awards. It is concluded that a full transition toward a hydrogen economy can begin in the next decade.

  10. Isolation of lactic acid bacteria exhibiting high scavenging activity for environmental hydrogen peroxide from fermented foods and its two scavenging enzymes for hydrogen peroxide.

    Watanabe, Akio; Kaneko, Chiaki; Hamada, Yasuhiro; Takeda, Kouji; Kimata, Shinya; Matsumoto, Takashi; Abe, Akira; Tanaka, Naoto; Okada, Sanae; Uchino, Masataka; Satoh, Junichi; Nakagawa, Junichi; Niimura, Youichi

    2016-01-01

    To obtain lactic acid bacteria that scavenge environmental hydrogen peroxide, we developed a specialized enrichment medium and successfully isolated Pediococcus pentosaceus Be1 strain from a fermented food. This strain showed vigorous environmental hydrogen peroxide scavenging activity over a wide range of hydrogen peroxide concentrations. High Mn-catalase and NADH peroxidase activities were found in the cell-free extract of the P. pentosaceus Be1 strain, and these two hydrogen peroxide scavenging enzymes were purified from the cell-free extract of the strain. Mn-catalase has been purified from several microorganisms by several researchers, and the NADH peroxidase was first purified from the original strain in this report. After cloning the genes of the Mn-catalase and the NADH peroxidase, the deduced amino acid sequences were compared with those of known related enzymes. PMID:27118075

  11. Theoretical hydrogen-line ratios for the narrow-line regions of active galactic nuclei

    H-alpha/H-beta (Ha/Hb) and other hydrogen line ratios for narrow line regions (NLR) of active galactic nuclei (AGN) were calculated, and their sensitivity to model parameters was investigated. The computations were performed with the photoionization code CLOUDY, with hydrogen treated as a seven-level plus continuum atom. Ha/Hb was sensitive to the ionization parameter and only weakly dependent on the electron density. Metallicity and the shape of the UV to X-ray continuum had the greatest impacts. It is recommended that Ha/Hb with a value of 3.0 be used as a reddening indicator for NLR of AGN. 21 references

  12. Effect of menadione and hydrogen peroxide on catalase activity in Saccharomyces yeast strains

    Nadejda EFREMOVA

    2013-05-01

    Full Text Available It has been studied the possibility of utilization of two important oxidant factors as regulators of catalase activity in Saccharomyces yeasts. In this paper results of the screening of some Saccharomyces yeast strains for potential producers of catalase are presented. Results of the screening for potential catalase producer have revealed that Saccharomyces cerevisiae CNMN-Y-11 strain possesses the highest catalase activity (2900 U/mg protein compared with other samples. Maximum increase of catalase activity with 50-60% compared to the reference sample was established in the case of hydrogen peroxide and menadione utilization in optimal concentrations of 15 and 10 mM. This research has been demonstrated the potential benefits of application of hydrogen peroxide and menadione as stimulatory factors of catalase activity in Saccharomyces yeasts.

  13. Development of a National Center for Hydrogen Technology. A Summary Report of Activities Completed at the National Center for Hydrogen Technology - Year 6

    Holmes, Michael [Univ. of North Dakota, Grand Forks, ND (United States)

    2012-08-01

    The Energy & Environmental Research Center (EERC) located in Grand Forks, North Dakota, has operated the National Center for Hydrogen Technology (NCHT) since 2005 under a Cooperative Agreement with the U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL). The EERC has a long history of hydrogen generation and utilization from fossil fuels, and under the NCHT Program, the EERC has accelerated its research on hydrogen generation and utilization topics. Since the NCHT's inception, the EERC has received more than $65 million in funding for hydrogen-related projects ($24 million for projects in the NCHT, which includes federal and corporate partner development funds) involving more than 85 partners (27 with the NCHT). The NCHT Program's nine activities span a broad range of technologies that align well with the Advanced Fuels Program goals and, specifically, those described in the Hydrogen from Coal Program research, development, and demonstration (RD&D) plan that refers to realistic testing of technologies at adequate scale, process intensification, and contaminant control. A number of projects have been completed that range from technical feasibility of several hydrogen generation and utilization technologies to public and technical education and outreach tools. Projects under the NCHT have produced hydrogen from natural gas, coal, liquid hydrocarbons, and biomass. The hydrogen or syngas generated by these processes has also been purified in many of these instances or burned directly for power generation. Also, several activities are still undergoing research, development, demonstration, and commercialization at the NCHT. This report provides a summary overview of the projects completed in Year 6 of the NCHT. Individual activity reports are referenced as a source of detailed information on each activity.

  14. Development of a national center for hydrogen technology. A summary report of activities completed at the national center hydrogen technology from 2005 to 2010

    Holmes, Michael J. [Univ. of North Dakota, Grand Forks, ND (United States)

    2011-06-01

    The Energy & Environmental Research Center (EERC) located in Grand Forks, North Dakota, has operated the National Center for Hydrogen Technology® (NCHT®) since 2005 under a Cooperative Agreement with the U.S. Department of Energy's (DOE) National Energy Technology Laboratory (NETL). The EERC has a long history of hydrogen generation and utilization from fossil fuels, and under the NCHT Program, the EERC has accelerated its research of hydrogen generation and utilization topics. Since the NCHT's inception, the EERC has received more than $65 million in funding of hydrogen-related projects ($20 million for the NCHT project which includes federal and corporate development partner funds) involving more than 85 partners (27 with the NCHT). The NCHT project's 19 activities span a broad range of technologies that align well with the Advanced Fuels Program goals and, specifically, those described in the Hydrogen from Coal Program research, development, and demonstration (RD&D) plan. A number of projects have been completed which range from technical feasibility of several hydrogen generation and utilization technologies to public and technical education and outreach tools. Projects under the NCHT have produced hydrogen from natural gas, coal, liquid hydrocarbons, and biomass. The hydrogen or syngas generated by these processes has also been purified to transportation-grade quality in many of these instances or burned directly for power generation. Also, several activities are still undergoing research, development, demonstration, and commercialization at the NCHT. This report provides a summary overview of the projects completed in the first 5 years of the NCHT. Individual activity reports are referenced as a source of detailed information on each activity.

  15. Design Strategies for Redox Active Metalloenzymes: Applications in Hydrogen Production.

    Alcala-Torano, R; Sommer, D J; Bahrami Dizicheh, Z; Ghirlanda, G

    2016-01-01

    The last decades have seen an increased interest in finding alternative means to produce renewable fuels in order to satisfy the growing energy demands and to minimize environmental impact. Nature can serve as an inspiration for development of these methodologies, as enzymes are able to carry out a wide variety of redox processes at high efficiency, employing a wide array of earth-abundant transition metals to do so. While it is well recognized that the protein environment plays an important role in tuning the properties of the different metal centers, the structure/function relationships between amino acids and catalytic centers are not well resolved. One specific approach to study the role of proteins in both electron and proton transfer is the biomimetic design of redox active peptides, binding organometallic clusters in well-understood protein environments. Here we discuss different strategies for the design of peptides incorporating redox active FeS clusters, [FeFe]-hydrogenase organometallic mimics, and porphyrin centers into different peptide and protein environments in order to understand natural redox enzymes. PMID:27586342

  16. PROCESS OPTIMIZATION OF TETRA ACETYL ETHYLENE DIAMINE ACTIVATED HYDROGEN PEROXIDE BLEACHING OF POPULUS NIGRA CTMP

    Qiang Zhao; Junwen Pu; Shulei Mao; Guibo Qi

    2010-01-01

    To enhance the bleaching efficiency, the activator of tetra acetyl ethylene diamine (TAED) was used in conventional H2O2 bleaching. The H2O2/TAED bleaching system can accelerate the reaction rate and shorten bleaching time at relative low temperature, which can reduce the production cost. In this research, the process with hydrogen peroxide activated by TAED bleaching of Populus nigra chemi-thermo mechanical pulp was optimized. Suitable bleaching conditions were confirmed as follows: pulp con...

  17. Re-Examining the Role of Hydrogen Peroxide in Bacteriostatic and Bactericidal Activities of Honey

    Brudzynski, Katrina; Abubaker, Kamal; St-Martin, Laurent; Castle, Alan

    2011-01-01

    The aim of this study was to critically analyze the effects of hydrogen peroxide on growth and survival of bacterial cells in order to prove or disprove its purported role as a main component responsible for the antibacterial activity of honey. Using the sensitive peroxide/peroxidase assay, broth microdilution assay and DNA degradation assays, the quantitative relationships between the content of H2O2 and honey’s antibacterial activity was established. The results showed that: (A) the average...

  18. Design optimization of a 0.1-ton/day active magnetic regenerative hydrogen liquefier

    Zhang, L.; Sherif, S. A.; DeGregoria, A. J.; Zimm, C. B.; Veziroglu, T. N.

    2000-04-01

    A design optimization procedure of a 0.1-ton/day active magnetic regenerative (AMR) hydrogen liquefier model is described. The liquefier is proposed for the industrial liquid hydrogen market with overall efficiency being the primary measure of performance. This performance is described here in terms of particle size, bed length, and inter-stage temperature. Efficiency comparable to larger gas cycle plants is predicted. The magnetic liquefier may be modified to operate as a two-stage magnetic refrigerator between 77 and 20 K with high efficiency. The paper describes an optimization method as applied to the design of a two-stage AMR hydrogen liquefier and presents the associated results. A five-parameter optimization process is performed since there are five changeable parameters; the low- and high-stage particle sizes, the low- and high-stage bed lengths, and the inter-stage temperature. Model results are presented and compared with experimental results of an actual liquefier.

  19. Preconceptual Design Description for Caustic Recycle Facility

    Sevigny, Gary J.; Poloski, Adam P.; Fountain, Matthew S.; Kurath, Dean E.

    2008-04-12

    The U.S. Department of Energy plans to vitrify both high-level and low-activity waste at the Hanford Site in southeastern Washington State. One aspect of the planning includes a need for a caustic recycle process to separate sodium hydroxide for recycle. Sodium is already a major limitation to the waste-oxide loading in the low-activity waste glass to be vitrified at the Waste Treatment Plant, and additional sodium hydroxide will be added to remove aluminum and to control precipitation in the process equipment. Aluminum is being removed from the high level sludge to reduce the number of high level waste canisters produced. A sodium recycle process would reduce the volume of low-activity waste glass produced and minimize the need to purchase new sodium hydroxide, so there is a renewed interest in investigating sodium recycle. This document describes an electrochemical facility for recycling sodium for the WTP.

  20. Modeling of the thermal effects of hydrogen adsorption on activated carbon

    Richard, M.-A.; Chahine, R. [Univ. du Quebec a Trois-Rivieres, Inst. de recherche sur l' hydrogene, Trois-Rivieres, Quebec (Canada)]. E-mail: marc-andre.richard@uqtr.ca

    2006-07-01

    'Full text:' Heat management is one of the most critical issues for the design of efficient adsorption-based storage of hydrogen. We present simulations of mass and energy balance for hydrogen and nitrogen adsorption on activated carbon over wide temperature and pressure ranges. First, the Dubinin-Astakhov (DA) model is adapted to model excess hydrogen and nitrogen adsorption isotherms at high pressures and supercritical temperatures assuming a constant microporous adsorption volume. The five parameter modified D-A adsorption model is shown to fit the experimental data over the temperature range (35 K-293 K) for hydrogen and (93 K-298 K) for nitrogen and pressure range (0-6 MPa) within the experimental uncertainties of the measurement system. We derive the thermodynamic properties of the adsorbed phase from this analytical expression of the measured data. The mass and energy rate balance equations in a microporous adsorbent/adsorbate system are then presented and validated with nitrogen desorption experiments. Finally, simulations of adiabatic and isothermal filling of adsorption-based hydrogen storage are presented and discussed. (author)

  1. Effect of pre-strain on susceptibility of Indian Reduced Activation Ferritic Martensitic Steel to hydrogen embrittlement

    Sonak, Sagar; Tiwari, Abhishek; Jain, Uttam; Keskar, Nachiket; Kumar, Sanjay; Singh, Ram N.; Dey, Gautam K.

    2015-10-01

    The role of pre-strain on hydrogen embrittlement susceptibility of Indian Reduced Activation Ferritic Martensitic Steel was investigated using constant nominal strain-rate tension test. The samples were pre-strained to different levels of plastic strain and their mechanical behavior and mode of fracture under the influence of hydrogen was studied. The effect of plastic pre-strain in the range of 0.5-2% on the ductility of the samples was prominent. Compared to samples without any pre-straining, effect of hydrogen was more pronounced on pre-strained samples. Prior deformation reduced the material ductility under the influence of hydrogen. Up to 35% reduction in the total strain was observed under the influence of hydrogen in pre-strained samples. Hydrogen charging resulted in increased occurrence of brittle zones on the fracture surface. Hydrogen Enhanced Decohesion (HEDE) was found to be the dominant mechanism of fracture.

  2. A comparative study of hydrogen uptake features of Co, Ni and Pd modified nanofibres and activated carbon

    D' Elia, Luis F.; Gonzalez, I.; Saavedra, K.; Gottberg, V. [Petroleos de Venezuela (PDVSA)-Intevep, Gerencia General de Refinacion e Industrializacion, Gerencia Tecnica de Refinacion, Apartado 76343, Caracas 1070-A (Venezuela)

    2009-02-15

    Hydrogen represents a notable R and D area due to its impact on short and middle term energy business. Implementation of the so-called hydrogen economy still faces some technological breakthroughs. The most predominant belongs to storage; its state of the art is mainly focused on solid-state phenomena through physisorption or chemisorption. It has been found that thermal and acid pre-treatments of carbon nanofibres and activated carbon have opposite effects on hydrogen uptake levels. Thermal pre-treatment enhances hydrogen uptake; nonetheless, acid pre-treatment does not favour hydrogen-carbon interactions. Pd modified thermally-acidic pre-treated carbon materials have reversible hydrogen uptakes at the evaluated condition. On the other hand, Ni and Co modified thermally-acidic pre-treated carbon materials certainly uptake hydrogen, but it is not solely released (H{sub 2}O and CH{sub 4} are produced). (author)

  3. The activity of nanocrystalline Fe-based alloys as electrode materials for the hydrogen evolution reaction

    Müller, Christian Immanuel; Sellschopp, Kai; Tegel, Marcus; Rauscher, Thomas; Kieback, Bernd; Röntzsch, Lars

    2016-02-01

    In view of alkaline water electrolysis, the activities for the hydrogen evolution reaction of nanocrystalline Fe-based electrode materials were investigated and compared with the activities of polycrystalline Fe and Ni. Electrochemical methods were used to elucidate the overpotential value, the charge transfer resistance and the double layer capacity. Structural properties of the electrode surface were determined with SEM, XRD and XPS analyses. Thus, a correlation between electrochemical and structural parameters was found. In this context, we report on a cyclic voltammetric activation procedure which causes a significant increase of the surface area of Fe-based electrodes leading to a boost in effective activity of the activated electrodes. It was found that the intrinsic activity of activated Fe-based electrodes is very high due to the formation of a nanocrystalline surface layer. In contrast, the activation procedure influences only the intrinsic activity of the Ni electrodes without the formation of a porous surface layer.

  4. Automotive Aluminium Recycling

    Gelas, B. des

    2000-07-01

    This paper aims at providing an overview on the contribution of aluminium recycling in the supply of new aluminium for automotive applications. Based on a presentation on how the global European automotive aluminium supply requirements are met, an analysis of the present and future contribution of automotive aluminium recycling is first presented. Current situation and future developments for automotive aluminium recycling practices are then commented, together with an outline on design principles for easier aluminium recycling. (orig.)

  5. Hydrogen Programs of Asian Countries

    The global sustainability is a key word of the future energy system for human beings. It should be friendly to the earth and also to human beings. Considering the limit of resources, the materials recycling would be very important. Considering the second law of thermodynamics, the entropy production through any processes would be the final problems for the sustainable growth. We have to think how to dispose the increasing entropy outside earth in the clean energy system. At present, the global carbon cycle is changing by the emission of CO2 with the large consumption of fossil fuels. The global environment including human society should stand on harmonizing with the earth, where the global recycles of materials are important. Thinking about the global recycles of carbon and water quantitatively, the existence of water is 27,000 times larger than that of carbon. The transportation of water is 3,160 times faster than that of carbon. These figures show that the hydrogen from water is a superior energy carrier, compared to the carbon. The environmental impact factor was defined as the ratio of annual quantity of materials produced by energy consumption of mankind to a natural movement on earth. The influence of human activities on the global environment can be evaluated quantitatively by this environmental impact factor. The environmental impact factor of water on the earth, 0.0001, is more than two orders of magnitude less than that of carbon, 0.036. This means the hydrogen/water cycle is superior to the carbon cycle as material circulation for energy system of mankind. The energy consumption will increase tremendously in Asian countries due to their population increase and economic growth. We need a clean energy system for the sustainable growth. The hydrogen energy system is the most suitable energy system. In this paper the recent hydrogen energy programs of Japan, China and Korea will be introduced. (author)

  6. Cryogenic hydrogen-induced air-liquefaction technologies

    Escher, William J. D.

    1990-01-01

    Extensive use of a special advanced airbreathing propulsion archives data base, as well as direct contacts with individuals who were active in the field in previous years, a technical assessment of cryogenic hydrogen induced air liquefaction, as a prospective onboard aerospace vehicle process, was performed and documented in 1986. The resulting assessment report is summarized. Technical findings relating the status of air liquefaction technology are presented both as a singular technical area, and also as that of a cluster of collateral technical areas including: Compact lightweight cryogenic heat exchangers; Heat exchanger atmospheric constituents fouling alleviation; Para/ortho hydrogen shift conversion catalysts; Hydrogen turbine expanders, cryogenic air compressors and liquid air pumps; Hydrogen recycling using slush hydrogen as heat sinks; Liquid hydrogen/liquid air rocket type combustion devices; Air Collection and Enrichment System (ACES); and Technically related engine concepts.

  7. Chemical Recycle of Plastics

    Sara Fatima

    2014-11-01

    Full Text Available Various chemical processes currently prevalent in the chemical industry for plastics recycling have been discussed. Possible future scenarios in chemical recycling have also been discussed. Also analyzed are the effects on the environment, the risks, costs and benefits of PVC recycling. Also listed are the various types of plastics and which plastics are safe to use and which not after rcycle

  8. The recycling is moving

    GS Department

    2011-01-01

    The recycling site currently situated near building 133 has been transferred to the car park of building 156. The site is identified by the sign “RECYCLING” and the above logo. In this new, more accessible site, you will find recycling bins for the following waste: PET (recyclable plastic bottles); Aluminium cans; Nespresso coffee capsules.  

  9. Chemical and ecotoxicological analyses of sediments and elutriates of contaminated rivers due to e-waste recycling activities using a diverse battery of bioassays

    Wang, F.; Leung, A.O.W.; Wu, S.C.; Yang, M.S. [Croucher Institute for Environmental Sciences, and Department of Biology, Hong Kong Baptist University, Kowloon Tong (Hong Kong); Wong, M.H., E-mail: mhwong@hkbu.edu.h [Croucher Institute for Environmental Sciences, and Department of Biology, Hong Kong Baptist University, Kowloon Tong (Hong Kong)

    2009-07-15

    A multi-trophic, multi-exposure phase assessment approach was applied to characterize the toxicity of sediments collected from two rivers in Guiyu, China, an e-waste recycling centre. Elutriate toxicity tests (bacterium Vibrio fischeri and microalga Selenastrum capricornutum) and whole sediment toxicity test (crustacean Heterocypris incongruens) showed that most sediments exhibited acute toxicity, due to elevated heavy metals and PAHs levels, and low pH caused by uncontrolled acid discharge. The survival rates of crustaceans were negatively (p < 0.05) correlated with total PAHs in sediments (411-1755 mg kg{sup -1}); EC50s of V. fischeri on the elutriates were significantly correlated with elutriate pH (p < 0.01). Significant (p < 0.05) correlations between the induction of hepatic metallothionein in tilapia (Oreochromis mossambicus) and metal concentrations (Cu, Zn, Pb) in sediments were also observed, when fish were fed with diets containing sediment. The results showed that uncontrolled e-waste recycling activities may bring adverse effects to local aquatic ecosystem. - Toxicity tests using different trophic organisms provided important information, supplementing chemical analyses.

  10. Chemical and ecotoxicological analyses of sediments and elutriates of contaminated rivers due to e-waste recycling activities using a diverse battery of bioassays

    A multi-trophic, multi-exposure phase assessment approach was applied to characterize the toxicity of sediments collected from two rivers in Guiyu, China, an e-waste recycling centre. Elutriate toxicity tests (bacterium Vibrio fischeri and microalga Selenastrum capricornutum) and whole sediment toxicity test (crustacean Heterocypris incongruens) showed that most sediments exhibited acute toxicity, due to elevated heavy metals and PAHs levels, and low pH caused by uncontrolled acid discharge. The survival rates of crustaceans were negatively (p -1); EC50s of V. fischeri on the elutriates were significantly correlated with elutriate pH (p < 0.01). Significant (p < 0.05) correlations between the induction of hepatic metallothionein in tilapia (Oreochromis mossambicus) and metal concentrations (Cu, Zn, Pb) in sediments were also observed, when fish were fed with diets containing sediment. The results showed that uncontrolled e-waste recycling activities may bring adverse effects to local aquatic ecosystem. - Toxicity tests using different trophic organisms provided important information, supplementing chemical analyses.

  11. Polarographic assay based on hydrogen peroxide scavenging in determination of antioxidant activity of strong alcohol beverages.

    Gorjanović, Stanislava Z; Novaković, Miroslav M; Vukosavljević, Predrag V; Pastor, Ferenc T; Tesević, Vele V; Suznjević, Desanka Z

    2010-07-28

    Total antioxidant (AO) activity of strong alcohol beverages such as wine and plum brandies, whiskeys, herbal and sweet fruit liqueurs have been assessed using a polarographic assay based on hydrogen peroxide scavenging (HPS). Rank of order of total AO activity, expressed as percentage of decrease of anodic oxidation current of hydrogen peroxide, was found analogous with total phenolic content estimated by Folin-Ciocalteau (FC) assay and radical scavenging capacity against the stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH). Application of the assay for surveying of a quarter century long maturation of plum brandy in oak barrel was demonstrated. In addition, influence of different storage conditions on preservation of AO activity of some herbal liqueurs was surveyed. Wide area of application of this simple, fast, low cost and reliable assay in analysis and quality monitoring of various strong alcohol beverages was confirmed. PMID:20604507

  12. Stabilizing a Platinum1 Single-Atom Catalyst on Supported Phosphomolybdic Acid without Compromising Hydrogenation Activity.

    Zhang, Bin; Asakura, Hiroyuki; Zhang, Jia; Zhang, Jiaguang; De, Sudipta; Yan, Ning

    2016-07-11

    In coordination chemistry, catalytically active metal complexes in a zero- or low-valent state often adopt four-coordinate square-planar or tetrahedral geometry. By applying this principle, we have developed a stable Pt1 single-atom catalyst with a high Pt loading (close to 1 wt %) on phosphomolybdic acid(PMA)-modified active carbon. This was achieved by anchoring Pt on the four-fold hollow sites on PMA. Each Pt atom is stabilized by four oxygen atoms in a distorted square-planar geometry, with Pt slightly protruding from the oxygen planar surface. Pt is positively charged, absorbs hydrogen easily, and exhibits excellent performance in the hydrogenation of nitrobenzene and cyclohexanone. It is likely that the system described here can be extended to a number of stable SACs with superior catalytic activities. PMID:27240266

  13. Implementing a campus wide recycling program

    'Full text:' The University of Windsor is currently expanding its recycling program to include all buildings on campus, but faces two challenges: 1) uncertainty about the current waste composition and distribution on campus; and 2) uncertainty about the effectiveness of increased recycling. This project assesses the current waste composition and the attitudes of the students towards recycling, and evaluates the effectiveness of proposed recycling activities. At present, paper is the only material that is collected throughout the entire campus. Except for two buildings, all other potentially recyclable materials within buildings, such as metal, glass, and plastic beverage containers, are discarded. The main focus of this research is on beverage containers as they represent clearly identifiable materials, but other materials were examined as well. To quantify the waste, different buildings on campus were classified according to their function: academic,operational and administrative. The waste composition study indicated that approximately 33% of the campus waste which is landfilled is composed of potentially recyclable material. A survey was then conducted to gauge the campus population's views on recycling issues that could affect the design of a recycling program. Interestingly, 97% of the respondents indicated a high willingness to recycle, but were uncertain as to how and where to recycle on campus. The project is currently assessing potential diversion rates using new, clearly identifiable recycling receptacles placed within selected classrooms for all major materials. There is a significant tradeoff however because the cost for new receptacles is considerable: multiple materials containers are often placed in high pedestrian traffic locations (e.g., hallways) and not always in classrooms,of which there are often many. This project will evaluate the basic benefits and costs of implementing a more comprehensive recycling program, and recommend how other

  14. Metal and precursor effect during 1-heptyne selective hydrogenation using an activated carbon as support.

    Lederhos, Cecilia R; Badano, Juan M; Carrara, Nicolas; Coloma-Pascual, Fernando; Almansa, M Cristina; Liprandi, Domingo; Quiroga, Mónica

    2013-01-01

    Palladium, platinum, and ruthenium supported on activated carbon were used as catalysts for the selective hydrogenation of 1-heptyne, a terminal alkyne. All catalysts were characterized by temperature programmed reduction, X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy. TPR and XPS suggest that the metal in all catalysts is reduced after the pretreatment with H2 at 673 K. The TPR trace of the PdNRX catalyst shows that the support surface groups are greatly modified as a consequence of the use of HNO3 during the catalyst preparation. During the hydrogenation of 1-heptyne, both palladium catalysts were more active and selective than the platinum and ruthenium catalysts. The activity order of the catalysts is as follows: PdClRX>PdNRX>PtClRX≫RuClRX. This superior performance of PdClRX was attributed in part to the total occupancy of the d electronic levels of the Pd metal that is supposed to promote the rupture of the H2 bond during the hydrogenation reaction. The activity differences between PdClRX and PdNRX catalysts could be attributed to a better accessibility of the substrate to the active sites, as a consequence of steric and electronic effects of the superficial support groups. The order for the selectivity to 1-heptene is as follows: PdClRX=PdNRX>RuClRX>PtClRX, and it can be mainly attributed to thermodynamic effects. PMID:24348168

  15. Emulsified industrial oils recycling

    Gabris, T.

    1982-04-01

    The industrial lubricant market has been analyzed with emphasis on current and/or developing recycling and re-refining technologies. This task has been performed for the United States and other industrialized countries, specifically France, West Germany, Italy and Japan. Attention has been focused at emulsion-type fluids regardless of the industrial application involved. It was found that emulsion-type fluids in the United States represent a much higher percentage of the total fluids used than in other industrialized countries. While recycling is an active matter explored by the industry, re-refining is rather a result of other issues than the mere fact that oil can be regenerated from a used industrial emulsion. To extend the longevity of an emulsion is a logical step to keep expenses down by using the emulsion as long as possible. There is, however, another important factor influencing this issue: regulations governing the disposal of such fluids. The ecological question, the respect for nature and the natural balances, is often seen now as everybody's task. Regulations forbid dumping used emulsions in the environment without prior treatment of the water phase and separation of the oil phase. This is a costly procedure, so recycling is attractive since it postpones the problem. It is questionable whether re-refining of these emulsions - as a business - could stand on its own if these emulsions did not have to be taken apart for disposal purposes. Once the emulsion is separated into a water and an oil phase, however, re-refining of the oil does become economical.

  16. Activities of Nuclear Research Institute Rez in the area of hydrogen technologies

    NRI is a research institution established in 1955. Nowadays, the Institute provides wide range of expertise and services for operators of the nuclear power plants in the Czech Republic and abroad, supports Czech central state institutions in the domains of strategic energy planning and development, management of radioactive waste (for the Ministry of Trade and Industry), provides independent expertise for the State Office of Nuclear Safety, performs activities in the area of exploitation of ionising radiation and irradiation services for basic and applied research, health service and industry, performs research and provides services for radioactive waste disposal, production of radiopharmaceuticals, education and training of experts and scientific specialists and performs many other activities. With the gradual changes in energy policy, hydrogen economy becomes one of the important topics related to nuclear energy. NRI is participating in the research and development in this area and as a member of the Czech Hydrogen Technology Platform is currently the leader in this area in the country. To promote hydrogen economy, NRI prepared and participated in several demonstration projects. Studies on production of hydrogen in current and future nuclear power plants are performed as well. (authors)

  17. Methanol steam reforming via internal recycle reactor. Paper no. IGEC-1-144

    Hydrogen generation for PEMFC by methanol steam reforming using a Caldwell internal recycle reactor (IRR) was studied. BASF K3-110 copper-based catalyst was used. The impeller speed and methanol retention time almost proportionally affected the recycle ratio, one of the most direct and important indices to show the gradientlessness of concentration and temperature. When the recycle ratio was greater than 20, internal recycle reactor could be considered as continuously stirred tank reactor (CSTR), one ideal reactor for kinetics studies with no appreciable concentration and temperature gradients. The experiment results via CSTR fit very well with the kinetics model developed using a differential reactor by Peppley et al.. This verified the accuracy of the Peppley model and vice versa. The pseudo first order reaction rate constant developed in the CSTR was found to be 0.1-0.15 mol/bar.kg.s, and the activation energy was 93 kJ/mol, which were in good accordance with Peppley model and other values reported in the literature. However, when the recycle ratio was too low, less than 20 for instance, either because of the high GHSV of reactants or low impeller speed, methanol conversion rate as well as CO2, H2 production rates were well below the values predicted by the Peppley model due to the existence of strong gradients of concentration and temperature. Regardless of the recycle ratio, CO producing rate in the IRR was lower than that via the plug flow reactor (PFR) in terms of Peppley model, which could be presumably ascribed to the strong inhibition effect of hydrogen on the reaction rate of methanol decomposition and reverse water gas shift (WGS) reaction over Cu based catalyst. This characteristic could be of benefit in reactor design to suppress CO yield which will be beneficial for producing PEMFC-grade reformate. (author)

  18. Recycled Fashion

    Sinha, Pammi; Dissanayake, D. G. K.; Hussey, Clare, J.; Bartlett, Caroline

    2009-01-01

    Globally, the textiles industry is worth over $1 trillion, ranked the second biggest global economic activity for intensity of trade, and employs approximately 26 million people. Moreover, it contributes to 7% of world exports, supporting a number of developing, small and industrialised economies as well as individual incomes around the world. The fastest growing sector in household waste is Textiles. Over the last ten years, discounting and low retail prices in the UK have led to 60% increas...

  19. Influence of hydrogen annealing on the photocatalytic activity of diamond-supported gold catalysts.

    Navalon, Sergio; Sempere, David; Alvaro, Mercedes; Garcia, Hermenegildo

    2013-08-14

    Fenton-treated diamond nanoparticles have been submitted to hydrogen reduction at 500 °C with the purpose of modifying the nature of the functional groups present on the diamond surface. The nature of the functional groups on the diamond samples was characterized by a combination of spectroscopic and analytical techniques. In particular, Fourier-transformed infrared spectroscopy, temperature-programmed desorption, and X-ray photoelectron spectroscopy (XPS) show the decrease in the population of carboxylic acids, esters, and anhydrides after hydrogen treatment. XPS also shows a decrease on the oxygen content after the hydrogen treatment of the diamond nanoparticles and lower electronegativity of the carbons as assessed by the lower binding energy values. Although Fenton-treated diamond colloids in water changes the zeta potential from positive to negative values as a function of the pH, hydrogen annealing and the disappearance of the carboxyl groups determines that the zeta potential of the resulting sample remains positive in the complete pH range. Deposition of gold nanoparticles was carried out by the polyol method consisting on the reduction of HAuCl4 by hot ethylene glycol in the presence of the support. TEM analysis shows a variation of the average gold nanoparticle size that decreases after hydrogen reduction of carboxylic groups and becomes smaller for low gold loadings. The catalytic activity of the diamond supported gold nanoparticles as a function of the surface annealing treatment and gold loading was evaluated for the natural sunlight-assisted peroxidation of phenol by H2O2. It was observed that the most efficient sample was the one having lower gold nanoparticle size that was obtained for diamond samples reduced by hydrogen at 500 °C after the Fenton treatment and having low gold loading (0.05 wt %). Turnover frequencies above 2400 and 940 h(-1) were obtained for phenol degradation and H2O2 decomposition, respectively. PMID:23815432

  20. Hydrogen sulfide and sodium nitroprusside compete to activate/deactivate MMPs in bone tissue homogenates

    Vacek TP

    2013-03-01

    Full Text Available Thomas P Vacek, Natia Qipshidze, Suresh C Tyagi Department of Physiology and Biophysics, University of Louisville School of Medicine, Louisville, KY, USA Background: Bone microvascular remodeling is the primary predictor of bone structure and function. Remodeling by its very nature implies synthesis and degradation of the extracellular matrix. Normally, 50% of total protein in the vessel wall is elastin. During remodeling, elastin is degraded by specialized matrix metalloproteinases (MMPs. Because the turnover of elastin is 1000-fold slower than that of collagen, most of the elastin is replaced by stiffer collagen. Stiffer vessels impose pressure on the aortic valve, causing regurgitation and increased pulse pressure. On the other hand, high MMP activity will cause vascular dilatation, leading to aneurysm. Therefore, balanced constitutive remodeling is necessary for adequate bone structure and function. Interestingly, collagen-degrading MMPs are involved in various pathological conditions, including osteoporosis, osteoarthritis, and cardiovascular disease. Sodium nitroprusside is a nitric oxide donor that could potentially alter MMP activity via vasodilation in vivo, but can also produce peroxynitrite, which activates MMPs by combining with superoxide. Moreover, hydrogen sulfide is a known antioxidant as well as a vasodilator, and is also speculated to contribute directly to MMP activity. We hypothesized that hydrogen sulfide reduced activity of MMP in ex vivo bone tissue homogenates and that sodium nitroprusside would increase MMP activity in vitro. Methods: We surgically removed the tibia and femur from anesthetized mice, and prepared bone tissue homogenates using a mortar and pestle, measured the protein concentration with a spectrophotometer, and detected MMP activity using gelatin gel zymography. Results: Our data showed increased MMP activity at a sodium nitroprusside concentration of 1 µM, and MMP activity increased exponentially. There

  1. A highly active and stable hydrogen evolution catalyst based on pyrite-structured cobalt phosphosulfide.

    Liu, Wen; Hu, Enyuan; Jiang, Hong; Xiang, Yingjie; Weng, Zhe; Li, Min; Fan, Qi; Yu, Xiqian; Altman, Eric I; Wang, Hailiang

    2016-01-01

    Rational design and controlled synthesis of hybrid structures comprising multiple components with distinctive functionalities are an intriguing and challenging approach to materials development for important energy applications like electrocatalytic hydrogen production, where there is a great need for cost effective, active and durable catalyst materials to replace the precious platinum. Here we report a structure design and sequential synthesis of a highly active and stable hydrogen evolution electrocatalyst material based on pyrite-structured cobalt phosphosulfide nanoparticles grown on carbon nanotubes. The three synthetic steps in turn render electrical conductivity, catalytic activity and stability to the material. The hybrid material exhibits superior activity for hydrogen evolution, achieving current densities of 10 mA cm(-2) and 100 mA cm(-2) at overpotentials of 48 mV and 109 mV, respectively. Phosphorus substitution is crucial for the chemical stability and catalytic durability of the material, the molecular origins of which are uncovered by X-ray absorption spectroscopy and computational simulation. PMID:26892437

  2. A highly active and stable hydrogen evolution catalyst based on pyrite-structured cobalt phosphosulfide

    Liu, Wen; Hu, Enyuan; Jiang, Hong; Xiang, Yingjie; Weng, Zhe; Li, Min; Fan, Qi; Yu, Xiqian; Altman, Eric I.; Wang, Hailiang

    2016-02-01

    Rational design and controlled synthesis of hybrid structures comprising multiple components with distinctive functionalities are an intriguing and challenging approach to materials development for important energy applications like electrocatalytic hydrogen production, where there is a great need for cost effective, active and durable catalyst materials to replace the precious platinum. Here we report a structure design and sequential synthesis of a highly active and stable hydrogen evolution electrocatalyst material based on pyrite-structured cobalt phosphosulfide nanoparticles grown on carbon nanotubes. The three synthetic steps in turn render electrical conductivity, catalytic activity and stability to the material. The hybrid material exhibits superior activity for hydrogen evolution, achieving current densities of 10 mA cm-2 and 100 mA cm-2 at overpotentials of 48 mV and 109 mV, respectively. Phosphorus substitution is crucial for the chemical stability and catalytic durability of the material, the molecular origins of which are uncovered by X-ray absorption spectroscopy and computational simulation.

  3. Recyclable UV and visible light photocatalytically active amorphous TiO{sub 2} doped with M (III) ions (M = Cr and Fe)

    Buddee, Supat [Department of Chemistry and Center for Innovation in Chemistry, Faculty of Science, Prince of Songkla University, 15 Kanjanavanich Road, Ko Hong, Hat Yai, Songkhla 90112 (Thailand); Wongnawa, Sumpun, E-mail: sumpun.w@psu.ac.th [Department of Chemistry and Center for Innovation in Chemistry, Faculty of Science, Prince of Songkla University, 15 Kanjanavanich Road, Ko Hong, Hat Yai, Songkhla 90112 (Thailand); Sirimahachai, Uraiwan; Puetpaibool, Walailak [Department of Chemistry and Center for Innovation in Chemistry, Faculty of Science, Prince of Songkla University, 15 Kanjanavanich Road, Ko Hong, Hat Yai, Songkhla 90112 (Thailand)

    2011-03-15

    Research highlights: {yields} The low photocatalytic activity of amorphous TiO2 was enhanced by doping with Cr(III) or Fe(III) ions. {yields} The doped catalysts performed close to P25 under UV light and better with visible light. {yields} The doped catalysts can be recycled. - Abstract: Samples of amorphous TiO{sub 2} doped with Cr(III) and Fe(III), designated as Cr-TiO{sub 2} and Fe-TiO{sub 2}, were prepared via modified impregnation method. The resulting products were characterized by X-ray diffraction, scanning electron microscopy, specific surface area by the Brunauer, Emmett and Teller method, UV-vis absorption and diffuse reflectance spectroscopy, and electron spin resonance spectroscopy. Experimental results revealed that the concentrations of dopants under studied, from 0.05 to 0.2 mol%, had no effect on the phase of products. The band gap energies shifted from 3.28 eV in the undoped amorphous TiO{sub 2} to 2.50 eV and 2.86 eV for Fe-TiO{sub 2} and Cr-TiO{sub 2}, respectively. The doped amorphous TiO{sub 2} showed photocatalytic activities under both UV and visible light with optimal results at 0.1 mol% dopants. Under UV irradiation, the 0.1 mol% doped samples decolorized methylene blue solutions to the same extent as the commercial TiO{sub 2} samples (P25 and anatase) in 5 h. Under visible light, the doped samples decolorized dye solutions in 12 h while the commercial ones were much less active. The used catalysts can be recycled many times without any special treatment.

  4. Recyclable UV and visible light photocatalytically active amorphous TiO2 doped with M (III) ions (M = Cr and Fe)

    Research highlights: → The low photocatalytic activity of amorphous TiO2 was enhanced by doping with Cr(III) or Fe(III) ions. → The doped catalysts performed close to P25 under UV light and better with visible light. → The doped catalysts can be recycled. - Abstract: Samples of amorphous TiO2 doped with Cr(III) and Fe(III), designated as Cr-TiO2 and Fe-TiO2, were prepared via modified impregnation method. The resulting products were characterized by X-ray diffraction, scanning electron microscopy, specific surface area by the Brunauer, Emmett and Teller method, UV-vis absorption and diffuse reflectance spectroscopy, and electron spin resonance spectroscopy. Experimental results revealed that the concentrations of dopants under studied, from 0.05 to 0.2 mol%, had no effect on the phase of products. The band gap energies shifted from 3.28 eV in the undoped amorphous TiO2 to 2.50 eV and 2.86 eV for Fe-TiO2 and Cr-TiO2, respectively. The doped amorphous TiO2 showed photocatalytic activities under both UV and visible light with optimal results at 0.1 mol% dopants. Under UV irradiation, the 0.1 mol% doped samples decolorized methylene blue solutions to the same extent as the commercial TiO2 samples (P25 and anatase) in 5 h. Under visible light, the doped samples decolorized dye solutions in 12 h while the commercial ones were much less active. The used catalysts can be recycled many times without any special treatment.

  5. Usage of Recycled Pet

    A. Ebru Tayyar

    2010-01-01

    Full Text Available The increasing industrialization, urbanization and the technological development have caused to increase depletion of the natural resources and environmental pollution's problem. Especially, for the countries which have not enough space recycling of the waste eliminating waste on regular basis or decreasing the amount and volume of waste have provided the important advantages. There are lots of studies and projects to develop both protect resources and prevent environmental pollution. PET bottles are commonly used in beverage industry and can be reused after physical and chemical recycling processes. Usage areas of recycled PET have been developed rapidly. Although recycled PET is used in plastic industry, composite industry also provides usage alternatives of recycled PET. Textile is a suitable sector for recycling of some plastics made of polymers too. In this study, the recycling technologies and applications of waste PET bottles have been investigated and scientific works in this area have been summarized.

  6. Dynamic Structural Changes During Complement C3 Activation Analyzed by Hydrogen/Deuterium Exchange Mass Spectrometry

    Schuster, Michael C.; Ricklin, Daniel; Papp, Krisztián; Molnar, Kathleen S.; Coales, Stephen J.; Hamuro, Yoshitomo; Sfyroera, Georgia; Chen, Hui; Winters, Michael S; Lambris, John D.

    2008-01-01

    Proteolytic cleavage of component C3 to C3b is a central step in the activation of complement. Whereas C3 is largely biologically inactive, C3b is directly involved in various complement activities. While the recently described crystal structures of C3 and C3b provide a molecular basis of complement activation, they do not reflect the dynamic changes that occur in solution. In addition, the available C3b structures diverge in some important aspects. Here we have utilized hydrogen/deuterium ex...

  7. Improvement of silicon direct bonding using surfaces activated by hydrogen plasma treatment

    Choi, W B; Lee Jae Sik; Sung, M Y

    2000-01-01

    The plasma surface treatment, using hydrogen gas, of silicon wafers was studied as a pretreatment for silicon direct bonding. Chemical reactions of the hydrogen plasma with the surfaces were used for both surface activation and removal of surface contaminants. Exposure of the silicon wafers to the plasma formed an active oxide layer on the surface. This layer was hydrophilic. The surface roughness and morphology were examined as functions of the plasma exposure time and power. The surface became smoother with shorter plasma exposure time and lower power. In addition, the plasma surface treatment was very efficient in removing the carbon contaminants on the silicon surface. The value of the initial surface energy, as estimated by using the crack propagation method, was 506 mJ/M sup 2 , which was up to about three times higher than the value for the conventional direct bonding method using wet chemical treatments.

  8. Passivation of electrically active centers by Hydrogen and Lithium in Semiconductors

    2002-01-01

    The hyperfine technique of Perturbed Angular Correlation Spectroscopy (PAC) has proven to be excellently suited for the microscopic investigation of impurity complexes in semiconductors. But this method is seriously limited by the small number of chemically different isotopes which are suitable for PAC measurements and represent electrically active centers in semiconductors. This bottleneck can be widely overcome by the ISOLDE facility which provides a great variety of shortliving PAC isotopes. The probe atom $^{111m}$Cd, provided by ISOLDE opened the first successful access to PAC investigations of III-V compounds and enabled also the first PAC experiments on double acceptors in silicon and germamum. \\\\ \\\\ At the new ISOLDE facility our experiments were concentrated on the passivation of electrically active centres by hydrogen and lithium in Si, Ge and III-V compounds. Experiments on $^{111m}$Cd in Ge revealed the formation of two different acceptor hydrogen and two different acceptor lithium complexes respe...

  9. The Activity of Ni-Based Catalysts on Steam Reforming of Glycerol for Hydrogen Production

    ALI SALEM EBSHISH

    2011-09-01

    Full Text Available Glycerol, the readily available bio renewable material, is effectively utilized for hydrogen production by a steam reforming reaction. The experiments were carried out in a continuous flow fixed-bed reactor over Nickel supported alumina catalysts under atmospheric pressure at 600°C and three hours reaction time. 5%wt Ni was loaded over γ-Al2O3 and effect of promoter metals such as Fe and Co over Ni/γ-Al2O3 catalytic systems were evaluated. The catalysts were characterized by BET surface area, XRD and SEM techniques. The activity results showed that the addition of Co enhanced the catalyst performance. The catalysts exhibited a good activity and selectivity to hydrogen.

  10. VALORIZATION OF INORGANIC SOLID WASTES FROM INDUSTRIAL ACTIVITIES INTO ACTIVE MATERIALS FOR REMOVAL OF HYDROGEN SULFIDE IN GAS PHASE

    Pham Xuan, Huynh; Pham Minh, Doan; Nzihou, Ange

    2015-01-01

    Hydrogen sulfide (H2S), which was formed from both natural and anthropogenic processes, is one of the most toxic contaminants affecting machine, people health, and ecosystem. Activated carbon and its derivatives (with metal oxides) are conventionally for H 2 S removal. However, they are expensive. Besides, the worldwide production of soda ash bases mostly on the Solvay Process ® (59% in 2000), which generates a large amounts of inorganic solid wastes with the main composition of CaCO 3. This ...

  11. Metal and Precursor Effect during 1-Heptyne Selective Hydrogenation Using an Activated Carbon as Support

    Lederhos, Cecilia R.; Badano, Juan M.; Nicolas Carrara; Fernando Coloma-Pascual; M. Cristina Almansa; Domingo Liprandi; Mónica Quiroga

    2013-01-01

    Palladium, platinum, and ruthenium supported on activated carbon were used as catalysts for the selective hydrogenation of 1-heptyne, a terminal alkyne. All catalysts were characterized by temperature programmed reduction, X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy. TPR and XPS suggest that the metal in all catalysts is reduced after the pretreatment with H2 at 673 K. The TPR trace of the PdNRX catalyst shows that the support surface groups are g...

  12. Sphalerite is a geochemical catalyst for carbon−hydrogen bond activation

    Shipp, Jessie A.; Gould, Ian R.; Shock, Everett L.; Williams, Lynda B.; Hartnett, Hilairy E.

    2014-01-01

    Organic compound transformations in the Earth commonly take place in the presence of minerals and aqueous solutions, but a mechanistic understanding of how minerals influence hydrothermal organic reactivity is virtually nonexistent. We present the first description of mineral catalysis of a fundamental organic reaction—carbon−hydrogen bond activation. The discovery that a common mineral, sphalerite (ZnS), can readily accomplish this reaction will interest not only geochemists but also the org...

  13. Microbial immobilization and recycling of 137Cs in the organic layers of forest ecosystems: Relationship to environmental conditions, humification and invertebrate activity

    The 137Cs content of the microbial biomass in the organic layers of 10 German forest sites was quantified with a modified fumigation/extraction method. A KCs factor was calculated for biomass 137Cs from the difference between unfumigated and fumigated samples by means of laboratory cultures. The size of the estimated KCs factors varied between 1.54 and 2.90 (mean, 2.17; S.D., 0.48). The microflora at the different forest sites contained between 1 and 56% of the total amount of 137Cs found in the organic layers (mean, 13%). Litterbag experiments showed that 137Cs was actively transported into the L layer by the microflora and that this effect was enhanced by the mesofauna. It is concluded that the immobilization and recycling of 137Cs by the microflora in the organic layer of forest soils is determined by three major factors: 137Cs availability, growth conditions of the microflora and biotic interactions

  14. Efficient Method for the Determination of the Activation Energy of the Iodide-Catalyzed Decomposition of Hydrogen Peroxide

    Sweeney, William; Lee, James; Abid, Nauman; DeMeo, Stephen

    2014-01-01

    An experiment is described that determines the activation energy (E[subscript a]) of the iodide-catalyzed decomposition reaction of hydrogen peroxide in a much more efficient manner than previously reported in the literature. Hydrogen peroxide, spontaneously or with a catalyst, decomposes to oxygen and water. Because the decomposition reaction is…

  15. A Micro-fabricated Hydrogen Storage Module with Sub-atmospheric Activation and Durability in Air Exposure.

    Shan, Xi; Payer, Joe H; Wainright, Jesse S; Dudik, Laurie

    2011-01-15

    The objective of this work was to develop a hydrogen storage module for onboard electrical power sources suitable for use in micro power systems and micro-electro-mechanical systems (MEMS). Hydrogen storage materials were developed as thin-film inks to be compatible with an integrated manufacturing process. Important design aspects were (a) ready activation at sub-atmospheric hydrogen pressure and room temperature and (b) durability, i.e. capable of hundreds of absorption/desorption cycles and resistance to deactivation on exposure to air. Inks with palladium-treated intermetallic hydrogen storage alloys were developed and are shown here to be compatible with a thin-film micro-fabrication process. These hydrogen storage modules absorb hydrogen readily at atmospheric pressure, and the absorption/desorption rates remained fast even after the ink was exposed to air for 47 weeks. PMID:20967132

  16. Attributes to facilitate e-waste recycling behaviour

    Senawi Nur Hidayah

    2016-01-01

    Full Text Available This study aims to identify the set of attributes to facilitate electronic waste (e-waste behaviour among the community. E-waste disposal is increasing from year to year in parallel with increasing of global population. The short lifespan of electronics and poor e-waste recycling behaviour is among the main contributors to the steadily increasing of e-waste generated. Current recycling rate among the nation is lacking behind, which is only 10.5%. A questionnaire survey has been conducted among the students in Universiti Teknologi Malaysia to evaluate the current e-waste recycling practice. The results showed that majority of the respondents did not recycle their e-waste on campus. Aggressive efforts is needed to realize the country’s target of 20% recycling rate in year 2020, one of the effective paths is to minimize e-waste generation via active e-waste recycling behaviour among the community. Extensive literatures have been reviewed to classify the attributes to facilitate effective e-waste recycling among the community. Total of five attributes that identified in this study which are Convenience of E- waste Recycling Infrastruture and Services, E-waste Recycling Information, Incentives For E-waste Recycling, Reminder to Recycle E-waste And E-waste Recycling Infrastructure and Services. The set of attributes identified in this study may serve as guideline for the management in designing program to foster e-waste recycling behaviour among the community.

  17. Hydrogen adsorption-mediated synthesis of concave Pt nanocubes and their enhanced electrocatalytic activity

    Lu, Bang-An; Du, Jia-Huan; Sheng, Tian; Tian, Na; Xiao, Jing; Liu, Li; Xu, Bin-Bin; Zhou, Zhi-You; Sun, Shi-Gang

    2016-06-01

    Concave nanocubes are enclosed by high-index facets and have negative curvature; they are expected to have enhanced reactivity, as compared to nanocubes with flat surfaces. Herein, we propose and demonstrate a new strategy for the synthesis of concave Pt nanocubes with {hk0} high-index facets, by using a hydrogen adsorption-mediated electrochemical square-wave potential method. It was found that Pt atoms prefer to deposit on edge sites rather than terrace sites on Pt surfaces with intensive hydrogen adsorption, resulting in the formation of concave structures. The as-prepared concave Pt nanocubes exhibit enhanced catalytic activity and stability towards oxidation of ethanol and formic acid in acidic solutions, compared to commercial Pt/C catalysts.Concave nanocubes are enclosed by high-index facets and have negative curvature; they are expected to have enhanced reactivity, as compared to nanocubes with flat surfaces. Herein, we propose and demonstrate a new strategy for the synthesis of concave Pt nanocubes with {hk0} high-index facets, by using a hydrogen adsorption-mediated electrochemical square-wave potential method. It was found that Pt atoms prefer to deposit on edge sites rather than terrace sites on Pt surfaces with intensive hydrogen adsorption, resulting in the formation of concave structures. The as-prepared concave Pt nanocubes exhibit enhanced catalytic activity and stability towards oxidation of ethanol and formic acid in acidic solutions, compared to commercial Pt/C catalysts. Electronic supplementary information (ESI) available: Details of DFT calculation, SEM images of concave Pt nanocubes, mass activity and stability characterization of the catalysts. See DOI: 10.1039/c6nr02349e

  18. Hydrogen water deuterium exchange studies on palladium on activated charcoal hydrophobic catalyst (Preprint No. CA-20)

    Deuterium exchange between hydrogen gas and water is one of the most promising processes for heavy water production. In production of heavy water, separation factor and energy cost are two main parameters which govern the economic effectiveness of a process. Out of the chemical exchange process, H2-H2O exchange has higher separation factor at a given temperature. Even though the separation factor is high, major disadvantage in the process is that a catalyst is required. Group VIII metals are most suitable catalysts for hydrogenation, dehydrogenation and hydrogenolysis because of their ability to chemisorb H2 dissociatively. Even among VIII2 triad, Pt has the highest activity. A highly active Pt catalyst has a reported half life of 4 seconds. As Pd is cheaper than Pt, studies have been carried out using active Pd as catalyst for H2-H2O exchange. It is observed that: (1)at metal concentration of 0.3%, Pd shows the optimum catalytic activity, (2)a highly active Pd is found to have a half life of 5 minutes, and (3)addition of α-alumina enhances the catalytic activity. (author). 6 refs., 5 figs

  19. Hydrogen evolution activity and electrochemical stability of selected transition metal carbides in concentrated phosphoric acid

    Highlights: • The hydrogen evolution activity (HER) on five transition metal carbides was studied in concentrated phosphoric acid at different temperatures. • Carbides of Group 6 metals (Cr, Mo, W) showed significant HER activity; the Volmer-Heyrovsky mechanism was proposed for the HER reaction on these materials. • The electrochemical stability towards oxidation was studied in concentrated phosphoric acid, with Cr, Ta and W carbides showing passivating behavior, while Nb and Mo carbides showed corrosion. - Abstract: Alternative catalysts based on carbides of Group 5 (niobium and tantalum) and 6 (chromium, molybdenum and tungsten) metals were prepared as films on the metallic substrates. The electrochemical activities of these carbide electrodes towards the hydrogen evolution reaction (HER) in concentrated phosphoric acid were investigated in a temperature range from 80 to 170 °C. A significant dependence of the activities on temperature was observed for all five carbide samples. Through the entire temperature range Group 6 metal carbides showed higher activity than that of the Group 5 metal carbides, attributable to the different electronic structures. Tungsten carbide among the studied electrode samples exhibited the highest HER activity. Upon anodic potential scans in the presence of oxygen, chromium, tantalum and tungsten carbides displayed passivation due to the formation of stable surface layers whereas niobium and molybdenum carbides seemed to undergo corrosion

  20. The importance of recycling - Responsible recycling

    7 times the total emissions from Sweden are saved each year by the recycling industry. It reduces CO2 emissions and saves the environment. In fact it annually reduces global CO2 emissions by 500 million tons, which is more than what is being emitted by the world wide aviation industry. Recycling of iron and steel saves 74% energy and reduces water and air pollution by respectively 76% and 86%, compared to primary production. It provides new raw materials and contributes to save energy. There's no sense in producing goods in a permanent material like plastics, that's supposed to be used only once. It's a huge waste of resources. Today the recycling industry provides half of the world's raw materials and this figure is set to increase. It's about environmentally sound management of resources. It's about plain common sense. There has to be a political willingness to facilitate recycling in every way. And from a corporate perspective social responsibility is becoming an increasingly important competitive edge. This is also a communication issue, it has to be a fact that is well known to the market when a company is doing valuable environmental work. We also need a well functioning global market with easy to understand regulations to facilitate global trade. The global demand for recycled materials should influence their collection and use. Fraud and theft has also to be kept at bay which calls for a close collaboration between organizations such as The International Chamber of Commerce, The International Trade Council and the International Maritime Bureau of the commercial crime services. Increasing recycling is the only way to go if we want to minimize our effect on the environment. We have to remember that recycling is essential for the environment. An increase would be a tremendous help to reduce the green house effect. Increasing recycling is not rocket science. We know how to do it, we just have to decide to go through with it

  1. Experience and activities in the field of plutonium recycling in civilian nuclear power plants in the European Union

    The European Union industry has established a world-wide leadership position in manufacturing and exploiting plutonium bearing fuel (MOX). About 15 to 20 tons of plutonium have been manufactured in the MOX fuel fabrication plants of E.U. companies. The current capacity of about 60 tons of MOX fuel per year is being upgraded to reach 400 tons/year by the year 2000. As a result, the excess amounts of separated plutonium, presently stored in the European Union, should no longer raise but should steadily decrease to converge to zero. Studies by the European Commission have indicated that the best use at present of weapons-grade and reactor-grade plutonium is to burn it in operating and future planned nuclear reactors. Disposing of plutonium by blending it with fission products or immobilising it into synthetic matrices appears to be far from being an industrially viable option. Following this path would mean to continue storing the excess plutonium of both military and civilian origin for an unknown, but very long period of time. For these and other reasons, the European Commission is striving to foster international cooperation between the European Union companies, having a long industrial experience accumulated in the field of recycling plutonium, and, so far, the Russian Federation and the Newly Independent States. This cooperation is aiming at supporting projects that could be mutually beneficial to all parties involved. To meet this objective, several programmes have been established either bilaterally or multilaterally, in particular within the framework of the International Science and Technology Centre (I.S.T.C.) in Moscow. Some examples of such collaborations will be described. (author)

  2. Development of Hierarchical Polymer@Pd Nanowire‐Network: Synthesis and Application as Highly Active Recyclable Catalyst and Printable Conductive Ink

    Mir, Sajjad Husain

    2016-01-01

    Abstract A facile one‐pot approach for preparing hierarchical nanowire‐networks of hollow polymer@Pd nanospheres is reported. First, polymer@Pd hollow nanospheres were produced through metal‐complexation‐induced phase separation with functionalized graft copolymers and subsequent self‐assembly of PdNPs. The nanospheres hierarchically assembled into the nanowire‐network upon drying. The Pd nanowire‐network served as an active catalyst for Mizoroki–Heck and Suzuki–Miyaura coupling reactions. As low as 500 μmol % Pd was sufficient for quantitative reactions, and the origin of the high activity is ascribed to the highly active sites originating from high‐index facets, kinks, and coalesced structures. The catalyst can be recycled via simple filtration and washing, maintaining its high activity owing to the micrometer‐sized hierarchical structure of the nanomaterial. The polymer@Pd nanosphere also served as a printable conductive ink for a translucent grid pattern with excellent horizontal conductivity (7.5×105 S m−1). PMID:27551657

  3. Activation of Hydrogen-Passivated Mg in GaN-Based Light Emitting Diode Annealing with Minority-Carrier Injection

    YANG Ling; HAO Yue; LI Pei-Xian; ZHOU Xiao-Wei

    2009-01-01

    We discuss an issue on the activation of p-GaN material under different annealing conditions and study the mechanism for the p-GaN activation. Under annealing in nitrogen, it is found that hydrogen cannot be completely removed from p-GaN. The experiments also indicate that rudimental hydrogen can exist stably in a certain state where hydrogen does not passivate the Mg acceptor in the sample annealing under bias. However, making additional annealing in nitrogen, we find that the steady state hydrogen can be decomposed and the Mg-H complex could generate again. Hydrogen remaining in the layer seems to play a major role in this reversible phenomenon.

  4. Hydrogen Adsorption on Activated Carbon an Carbon Nanotubes Using Volumetric Differential Pressure Technique

    A simple hydrogen adsorption measurement system utilizing the volumetric differential pressure technique has been designed, fabricated and calibrated. Hydrogen adsorption measurements have been carried out at temperatures 298 K and 77 K on activate carbon and carbon nanotubes with different surface areas. The adsorption data obtained will be helpful in understanding the adsorption property of the studied carbon materials using the fundamentals of adsorption theory. The principle of the system follows the Sievert-type method. The system measures a change in pressure between the reference cell, R1 and the sample cell S1, S2, S3 over a certain temperature range, R1, S1, S2, and S3 having known fixed volume. The sample temperatures will be monitored by thermocouple TC while the pressures in R1 an S1, S2, S3 will be measured using a digital pressure transducer. The maximum operating pressure of the pressure transducer is 20 bar and calibrated with an accuracy of ±0.01 bar. High purity hydrogen is being used in the system and the amount of samples for the study is between 1.0-2.0 grams. The system was calibrated using helium gas without any samples in S1, S2 an S3. This will provide a correction factor during the adsorption process providing an adsorption free reference point when using hydrogen gas resulting in a more accurate reading of the adsorption process by eliminating the errors caused by temperature expansion effects and other non-adsorption related phenomena. The ideal gas equation of state is applied to calculate the hydrogen adsorption capacity based on the differential pressure measurements. Activated carbon with a surface area of 644.87 m2/g showed a larger amount of adsorption as compared to multiwalled nanotubes (commercial) with a surface area of 119.68 m2/g. This study als indicated that there is a direct correlation between the amounts of hydrogen adsorbed an surface area of the carbon materials under the conditions studied and that the adsorption

  5. Ultrathin platinum nanowires grown on single-layered nickel hydroxide with high hydrogen evolution activity

    Yin, Huajie; Zhao, Shenlong; Zhao, Kun; Muqsit, Abdul; Tang, Hongjie; Chang, Lin; Zhao, Huijun; Gao, Yan; Tang, Zhiyong

    2015-03-01

    Design and synthesis of effective electrocatalysts for hydrogen evolution reaction in alkaline environments is critical to reduce energy losses in alkaline water electrolysis. Here we report a hybrid nanomaterial comprising of one-dimensional ultrathin platinum nanowires grown on two-dimensional single-layered nickel hydroxide. Judicious surface chemistry to generate the fully exfoliated nickel hydroxide single layers is explored to be the key for controllable growth of ultrathin platinum nanowires with diameters of about 1.8 nm. Impressively, this hybrid nanomaterial exhibits superior electrocatalytic activity for hydrogen evolution reaction in alkaline solution, which outperforms currently reported catalysts, and the obviously improved catalytic stability. We believe that this work may lead towards the development of single-layered metal hydroxide-based hybrid materials for applications in catalysis and energy conversion.

  6. Metal and Precursor Effect during 1-Heptyne Selective Hydrogenation Using an Activated Carbon as Support

    Cecilia R. Lederhos

    2013-01-01

    Full Text Available Palladium, platinum, and ruthenium supported on activated carbon were used as catalysts for the selective hydrogenation of 1-heptyne, a terminal alkyne. All catalysts were characterized by temperature programmed reduction, X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy. TPR and XPS suggest that the metal in all catalysts is reduced after the pretreatment with H2 at 673 K. The TPR trace of the PdNRX catalyst shows that the support surface groups are greatly modified as a consequence of the use of HNO3 during the catalyst preparation. During the hydrogenation of 1-heptyne, both palladium catalysts were more active and selective than the platinum and ruthenium catalysts. The activity order of the catalysts is as follows: PdClRX > PdNRX > PtClRX ≫ RuClRX. This superior performance of PdClRX was attributed in part to the total occupancy of the d electronic levels of the Pd metal that is supposed to promote the rupture of the H2 bond during the hydrogenation reaction. The activity differences between PdClRX and PdNRX catalysts could be attributed to a better accessibility of the substrate to the active sites, as a consequence of steric and electronic effects of the superficial support groups. The order for the selectivity to 1-heptene is as follows: PdClRX = PdNRX > RuClRX > PtClRX, and it can be mainly attributed to thermodynamic effects.

  7. Hydrogen sulfide monitoring and the effects of oil and gas activities on migratory birds in southeastern New Mexico [draft

    US Fish and Wildlife Service, Department of the Interior — This study examined the effects of hydrogen sulfide H2S, emitted by oil and gas activities, by focusing on migratory birds in southeastern New Mexico. Study sites...

  8. Combustion Byproducts Recycling Consortium

    Paul Ziemkiewicz; Tamara Vandivort; Debra Pflughoeft-Hassett; Y. Paul Chugh; James Hower

    2008-08-31

    Ashlines: To promote and support the commercially viable and environmentally sound recycling of coal combustion byproducts for productive uses through scientific research, development, and field testing.

  9. Mixed plastics recycling technology

    Hegberg, Bruce

    1995-01-01

    Presents an overview of mixed plastics recycling technology. In addition, it characterizes mixed plastics wastes and describes collection methods, costs, and markets for reprocessed plastics products.

  10. Enriching recycled uranium

    The paper reviews the progress of the use of recycled uranium during the period 1985-8. This article was originally presented as a paper at the 1988 Uranium Institute symposium (which was held in London). A description is given of the differences between natural and recycled uranium, and the presence of U236 in recycled uranium. The concept of equivalent reactivity is described, as well as the cost benefit of using recycled uranium. A summary of Urenco tests and trials with reprocessed uranium is given. Enrichment, UF6 conversion and fuel fabrication are also discussed. (U.K.)

  11. Lamps recycling aiming at the environment preservation

    The article discusses the following issues of lamps recycling in Brazil: mercury lamps recycling, recycling potential, energy conservation and environmental impacts, enterprises lamps recycling, and incentives policy

  12. Graphene stabilized ultra-small CuNi nanocomposite with high activity and recyclability toward catalysing the reduction of aromatic nitro-compounds

    Fang, Hao; Wen, Ming; Chen, Hanxing; Wu, Qingsheng; Li, Weiying

    2015-12-01

    Nowadays, it is of great significance and a challenge to design a noble-metal-free catalyst with high activity and a long lifetime for the reduction of aromatic nitro-compounds. Here, a 2D structured nanocomposite catalyst with graphene supported CuNi alloy nanoparticles (NPs) is prepared, and is promising for meeting the requirements of green chemistry. In this graphene/CuNi nanocomposite, the ultra-small CuNi nanoparticles (~2 nm) are evenly anchored on graphene sheets, which is not only a breakthrough in the structures, but also brings about an outstanding performance in activity and stability. Combined with a precise optimization of the alloy ratios, the reaction rate constant of graphene/Cu61Ni39 reached a high level of 0.13685 s-1, with a desirable selectivity as high as 99% for various aromatic nitro-compounds. What's more, the catalyst exhibited a unprecedented long lifetime because it could be recycled over 25 times without obvious performance decay or even a morphology change. This work showed the promise and great potential of noble-metal-free catalysts in green chemistry.Nowadays, it is of great significance and a challenge to design a noble-metal-free catalyst with high activity and a long lifetime for the reduction of aromatic nitro-compounds. Here, a 2D structured nanocomposite catalyst with graphene supported CuNi alloy nanoparticles (NPs) is prepared, and is promising for meeting the requirements of green chemistry. In this graphene/CuNi nanocomposite, the ultra-small CuNi nanoparticles (~2 nm) are evenly anchored on graphene sheets, which is not only a breakthrough in the structures, but also brings about an outstanding performance in activity and stability. Combined with a precise optimization of the alloy ratios, the reaction rate constant of graphene/Cu61Ni39 reached a high level of 0.13685 s-1, with a desirable selectivity as high as 99% for various aromatic nitro-compounds. What's more, the catalyst exhibited a unprecedented long lifetime

  13. Organic matter and hydrogen as electron donor for SRB and IRB activities in a clayey medium

    Document available in extended abstract form only. According to the French concept for the disposal of High-Level radioactive Waste (HLW), waste will be emplaced in an environment with multiple metallic components into a geological clay formation. The presence of microorganisms has recently been evidenced in deep clayey environment. Therefore, neither the introduction of microbial species during the construction and operational phases nor the survival of bacteria after the disposal closure can be excluded. Indeed, microbial species may be able to tolerate specific environment with few nutrients to sustain life under high temperature, dry and highly radioactive conditions. Moreover, despite the low porosity of clays, cracks in the excavated disturbed zone and remaining void spaces between disposal components may be favorable for bacterial growth. Sulfate-Reducing Bacteria (SRB) and Iron-Reducing Bacteria (IRB) activities are notably expected to influence iron-clay reactivity, including corrosion processes. Their potential development must be investigated in order to better assess their metabolism, which may in turn influence the evolution of metallic and clayey materials involved in a HLW disposal cell. More specifically, deep geological environments containing low amounts of biodegradable Organic Matter (OM) are generally nutrient poor for microbial development. However, the radiolysis of pore water and the corrosion of metallic components of HLW disposal cell in anoxic conditions will lead to the production of hydrogen, which may also be used as an electron donor for microbial activity. Thus, the purpose of the present work is to quantify the potential of bacterial growth stimulation due either to the production of hydrogen or the presence of OM. In a first step, characterization of DOM leached from Tournemire clay powder has been performed in order to identify and estimate the concentration of soluble organic matter available for bacteria activity which will

  14. The Synthesis and Electrocatalytic Activities of Molybdenum Sulfide for Hydrogen Evolution Reaction

    Li, Zhengxing

    2014-07-01

    In the context of the future hydrogen economy, effective production of hydrogen (H2) from readily available and sustainable resources is of crucial importance. Hydrogen generation via water splitting by solar energy or electricity has attracted great attention in recent years. In comparison with photocatalytic water-splitting directly using solar light, which is ideal but the relevant technologies are not yet mature, electrolysis of water with catalyst is more practical at the current stage. The Pt-group noble metals are the most effective electrocatalysts for hydrogen evolution reaction (HER) from water, but their high costs limit their applications. Due to the earth-abundance and low price, MoS2 is expected to be a good alternative of the Pt-group metals for HER. Plenty of researches have been conducted for improving the HER activities of MoS2 by optimizing its synthesis method. However, it remains challenging to prepare MoS2 catalysts with high and controllable activity, and more investigations are still needed to better understand the structure-performance correlation in this system. In this thesis, we report a new strategy for fabricating MoS2 eletrocatalysts which gives rise to much improved HER performance and allows us to tune the electrocatalytic activity by varying the preparation conditions. Specifically, we sulfurized molybdenum oxide on the surface of a Ti foil electrode via a facile chemical vapor deposition (CVD) method, and directly used the electrode for HER testing. Depending on the CVD temperature, the MoO2-MoS2 nanocomposites show different HER activities. Under the optimal synthesis condition (400ºC), the resulting catalyst exhibited excellent HER activity: an onset potential (overpotential) of 0.095 V versus RHE and the Tafel slope of 40 mv/dec. Such a performance exceeds those of most reported MoS2 based HER electrocatalysts. We demonstrated that the CVD temperature has significant influence on the catalysts in crystallinity degree, particle

  15. Removal of absorbable organic halides (aox) from recycled paper mill effluent using granular activated carbon-sequencing batch biofilm reactor (GAC-SBBR)

    Paper mills generate varieties of pollutants depending upon the type of the pulping process. Paper mill wastewaters have high chemical oxygen demand (COD) and colour, indicating high concentrations of recalcitrant organics. The study was conducted employing a Granular Activated Carbon - Sequencing Batch Biofilm Reactor (GAC-SBBR), containing 3.0 L working volume, operated in aerobic condition and packed with 200 g/L of 2-3 mm granular activated carbon (coconut shells) as a medium for biofilm growth. For the first couple of month, the HRT was 36 hours and the HRT of this reactor was adjusted to 24 hours in order to evaluate the performance of the system. The treated wastewater sample for these studies came from a recycle paper factory from MNI Sdn Bhd with 4 different samples characteristics. The adsorbable organic halides (AOX) to be determined and treated were Pentachlorophenol (PCP), 2,3,4,5-Tetrachlorophenol (2,3,4,5-TeCP), 2,4,6-Trichlorophenol (2,4,6-TCP), 2,4-Dichlorophenol ( 2,4-DCP), 2-Chlorophenol (CP) and phenol. Results showed that, the biofilm attached onto granular activated carbon (GAC) could substantially remove these recalcitrant in the wastewater. More over, results from the studies showed that high removal was achieved by the biofilm SBR with 10-100% removal of AOX and depending on HRT. (Author)

  16. Final Report: Main Group Element Chemistry in Service of Hydrogen Storage and Activation

    David A. Dixon; Anthony J. Arduengo, III

    2010-09-30

    goal was met in terms of reducing the number of costly experiments and helping to focus the experimental effort on the potentially optimal targets. We have used computational chemistry approaches to predict the thermodynamic properties of a wide range of compounds containing boron, nitrogen, hydrogen, and other elements as appropriate including carbon. These calculations were done in most cases with high level molecular orbital theory methods that have small error bars on the order of ± 1 to 2 kcal/mol. The results were used to benchmark more approximate methods such as density functional theory for larger systems and for database development. We predicted reliable thermodynamics for thousands of compounds for release and regeneration schemes to aid/guide materials design and process design and simulation. These are the first reliable computed values for these compounds and for many represent the only available values. Overall, the computational results have provided us with new insights into the chemistry of main group and organic-base chemical hydrogen systems from the release of hydrogen to the regeneration of spent fuel. A number of experimental accomplishments were also made in this project. The experimental work on hydrogen storage materials centered on activated polarized σ- or π-bonded frameworks that hold the potential for ready dihydrogen activation, uptake, and eventually release. To this end, a large number of non-traditional valence systems including carbenes, cyanocarbons, and C-B and and B-N systems were synthesized and examined. During the course of these studies an important lead arose from the novel valency of a class of stable organic singlet bi-radical systems. A synthetic strategy to an “endless” hydrogen storage polymer has been developed based on our cyanocarbon chemistry. A key issue with the synthetic efforts was being able to link the kinetics of release with the size of the substituents as it was difficult to develop a low molecular

  17. Activation of model nickel catalysts for hydrogenation of carbon dioxide to methane

    Barcicki, J.; Grzegorczyk, W.; Borowiecki, T.; Nazimek, D.; Denis, A.

    1977-09-01

    In studies related to steam reforming of hydrocarbons and to hydrogenation, the reaction of hydrogen with carbon dioxide in a 5:1 ratio at 400/sup 0/C for ten hr in a Carberry differential reactor over reduced nickel catalyst containing 0-10% of cobalt, copper, or iron metal, or of an oxide of potassium, zinc, barium, calcium, magnesium, chromium, or aluminum gave the best results over catalysts containing one of the last three oxides. The results included respective activity losses of 24.2, 20.4, and 7.24%; respective initial selectivities of 98.3, 98.5, and 97.6; respective final selectivities of 93.6, 95.9, and 96.6; and much higher activities, which increased with increasing promoter content; alumina gave the highest activity. Catalyst preparation and the role of the most effective promoters in increasing the active surface via changes in crystallite structure, and in improving catalyst thermal stability are discussed. Graphs, tables, and 22 references.

  18. Water-containing hydrogen-bonding network in the active center of channelrhodopsin.

    Ito, Shota; Kato, Hideaki E; Taniguchi, Reiya; Iwata, Tatsuya; Nureki, Osamu; Kandori, Hideki

    2014-03-01

    Channelrhodopsin (ChR) functions as a light-gated ion channel in Chlamydomonas reinhardtii. Passive transport of cations by ChR is fundamentally different from the active transport by light-driven ion pumps such as archaerhodopsin, bacteriorhodopsin, and halorhodopsin. These microbial rhodopsins are important tools for optogenetics, where ChR is used to activate neurons by light, while the ion pumps are used for neural silencing. Ion-transport functions by these rhodopsins strongly depend on the specific hydrogen-bonding networks containing water near the retinal chromophore. In this work, we measured protein-bound water molecules in a chimeric ChR protein of ChR1 (helices A to E) and ChR2 (helices F and G) of Chlamydomonas reinhardtii using low-temperature FTIR spectroscopy at 77 K. We found that the active center of ChR possesses more water molecules (9 water vibrations) than those of other microbial (2-6 water vibrations) and animal (6-8 water vibrations) rhodopsins. We conclude that the protonated retinal Schiff base interacts with the counterion (Glu162) directly, without the intervening water molecule found in proton-pumping microbial rhodopsins. The present FTIR results and the recent X-ray structure of ChR reveal a unique hydrogen-bonding network around the active center of this light-gated ion channel. PMID:24512107

  19. Mesophilic and thermophilic alkaline fermentation of waste activated sludge for hydrogen production: Focusing on homoacetogenesis.

    Wan, Jingjing; Jing, Yuhang; Zhang, Shicheng; Angelidaki, Irini; Luo, Gang

    2016-10-01

    The present study compared the mesophilic and thermophilic alkaline fermentation of waste activated sludge (WAS) for hydrogen production with focus on homoacetogenesis, which mediated the consumption of H2 and CO2 for acetate production. Batch experiments showed that hydrogen yield of WAS increased from 19.2 mL H2/gVSS at 37 °C and pH 10-80.1 mL H2/gVSS at 55 °C and pH 10. However, the production of volatile fatty acids (mainly acetate) was higher at 37 °C and pH 10 by comparison with 55 °C and pH 10. Hydrogen consumption due to homoacetogenesis was observed at 37 °C and pH 10 but not 55 °C and pH 10. Higher expression levels of genes relating with homoacetogenesis and lower expression levels of genes relating with hydrogen production were found at 37 °C and pH 10 compared to 55 °C and pH 10. The continuous experiment demonstrated the steady-state hydrogen yield of WAS was comparable to that obtained from batch experiments at 55 °C and pH 10, and homoacetogenesis was still inhibited. However, the steady-state hydrogen yield of WAS (6.5 mL H2/gVSS) was much lower than that (19.2 mL H2/gVSS) obtained from batch experiments at 37 °C and pH 10 due to the gradual enrichment of homoacetogens as demonstrated by qPCR analysis. The high-throughput sequencing analysis of 16S rRNA genes showed that the abundance of genus Clostridium, containing several homoacetogens, was 5 times higher at 37 °C and pH 10 than 55 °C and pH 10. PMID:27420808

  20. Hydrogen sensing characteristics of an electrodeposited WO3 thin film gasochromic sensor activated by Pt catalyst

    The hydrogen gas sensing performance of platinum (Pt) catalyst activated tungsten trioxide (WO3) thin films were investigated in the present study. The WO3 thin films exhibited a gasochromic effect; i.e., a reversible change in color from transparent when in air to blue when in hydrogen (H2). All processes proceeded rapidly at room temperature. The films were prepared by the electrodeposition method under ambient conditions. A layer of Pt was then sputtered onto the surface of WO3 film. The cycling of the coloration was obtained from UV-Vis spectra. The Pt catalyst dissociated H2 into H atoms, which then diffused into the WO3 thin film, which transformed from WO3 to HxW1-xVIWxVO3 and changed the color of the WO3 thin film. Therefore, we could detect the existence of H2 by the coloration of the WO3 thin film. Sensor properties of WO3/Pt films were investigated at room temperature in H2-N2 gas mixtures containing 0-50 mol% of H2. The results show that the transmittance change (ΔT) of the electrodeposited WO3 hydrogen sensor was ∼ 2% when the concentration of H2 was 5 mol%, and ∼ 20% when the concentration of H2 was 50 mol%. Coloration and bleaching had good response and recovery times in the range of 5-60 s, respectively

  1. Hydrogen activated axial inter-conversion in SiC nanowires

    A facile low pressure annealing route using NH3 as a hydrogen source for the structural and chemical modification of SiC nanowires (SiCNWs) is presented. The developed route transforms SiCNWs into tubular SiC nanostructures while coaxial SiO2/SiCNWs reverse their sheath/core structure. Our findings suggest a decomposition process induced via the preferential substitution of silicon by hydrogen and via the difference in diffusion rates of available atomic species, which leads to axial structural rearrangement. In addition to these effects, the procedure improves the crystallinity of the samples. The process could be exploited as a viable route to manipulate a variety of nanostructures and films for doping and etching and structural manipulation. - Graphical abstract: SiC and SiO2/SiCNWs are shown to be structurally modified through a hydrogen activated replacement route which can even lead to the axial inter-conversion of species. The process could be exploited as a viable route to manipulate a variety of nanostructures and films for doping and etching and structural manipulation

  2. Facile synthesis, characterization and recyclable photocatalytic activity of Ag{sub 2}WO{sub 4}@g-C{sub 3}N{sub 4}

    Vignesh, K., E-mail: vignesh134@gmail.com; Kang, Misook, E-mail: mskang@ynu.ac.kr

    2015-09-15

    Graphical abstract: The schematic diagram of electron–hole transfer process in Ag{sub 2}WO{sub 4}@g-C{sub 3}N{sub 4} under simulated solar light irradiation. - Highlights: • Ag{sub 2}WO{sub 4}@g-C{sub 3}N{sub 4} was synthesized by sono-chemical impregnation method. • Ag{sub 2}WO{sub 4}@g-C{sub 3}N{sub 4} was characterized using XRD, TEM, BET, UV-DRS and PL. • The photocatalytic activity was performed for the degradation of methylene blue. • Ag{sub 2}WO{sub 4}@g-C{sub 3}N{sub 4} showed excellent photocatalytic activity within 120 min. • Ag{sub 2}WO{sub 4}@g-C{sub 3}N{sub 4} was found to be a recyclable photocatalyst. - Abstract:: Silver tungstate (Ag{sub 2}WO{sub 4}) supported on graphite like carbon nitride (Ag{sub 2}WO{sub 4}@g-C{sub 3}N{sub 4}) was synthesized via sono-chemical impregnation method to improve the photo-stability. The photocatalytic performance was evaluated for the degradation of methylene blue (MB) dye under simulated solar light irradiation. The surface area, light absorption capacity and photocatalytic activity of Ag{sub 2}WO{sub 4} were improved in the presence of g-C{sub 3}N{sub 4} support. The photocatalyst of Ag{sub 2}WO{sub 4}@g-C{sub 3}N{sub 4} (40%) exhibited the best performance (100%) for the degradation of MB within 120 min of irradiation time. The recycling experiments revealed that the photo-corrosion behavior of Ag{sub 2}WO{sub 4} was strongly inhibited by g-C{sub 3}N{sub 4}. A possible mechanism was proposed to explain the electron–hole transfer process between Ag{sub 2}WO{sub 4} and g-C{sub 3}N{sub 4}. The results of this research work testified that Ag{sub 2}WO{sub 4}@g-C{sub 3}N{sub 4} could be used as a promising photocatalyst under solar light exposure.

  3. Effects of hydrogen and surface dislocation on active dissolution of deformed 304 austenitic stainless steel in acid chloride solution

    Research highlights: → An active dissolution model was proposed by the stored strain energy and electron work function. → An significant effect of plastic deformation on active dissolution was observed. → The synergistic effect between the dissolved hydrogen and applied stress is negligible. → The change of surface morphology due to dislocation made the electron more active. - Abstract: The mechanochemical effects between dissolved hydrogen and deformation on active dissolution of 304 stainless steel in acid chloride solution were investigated by use of constant loading test method. A theoretical model was proposed in terms of the stored strain energy and electron work function. Results indicated that active dissolution was affected mainly by Gibbs free energy produced by the part of plastic deformation and surface dislocation structure. A good agreement between the prediction and test results revealed that the synergistic effect of stress and dissolved hydrogen only promoted the process of active dissolution.

  4. Main Group Element Chemistry in Service of Hydrogen Storage and Activation. Final report

    goal was met in terms of reducing the number of costly experiments and helping to focus the experimental effort on the potentially optimal targets. We have used computational chemistry approaches to predict the thermodynamic properties of a wide range of compounds containing boron, nitrogen, hydrogen, and other elements as appropriate including carbon. These calculations were done in most cases with high level molecular orbital theory methods that have small error bars on the order of ± 1 to 2 kcal/mol. The results were used to benchmark more approximate methods such as density functional theory for larger systems and for database development. We predicted reliable thermodynamics for thousands of compounds for release and regeneration schemes to aid/guide materials design and process design and simulation. These are the first reliable computed values for these compounds and for many represent the only available values. Overall, the computational results have provided us with new insights into the chemistry of main group and organic-base chemical hydrogen systems from the release of hydrogen to the regeneration of spent fuel. A number of experimental accomplishments were also made in this project. The experimental work on hydrogen storage materials centered on activated polarized σ- or π-bonded frameworks that hold the potential for ready dihydrogen activation, uptake, and eventually release. To this end, a large number of non-traditional valence systems including carbenes, cyanocarbons, and C-B and and B-N systems were synthesized and examined. During the course of these studies an important lead arose from the novel valency of a class of stable organic singlet bi-radical systems. A synthetic strategy to an 'endless' hydrogen storage polymer has been developed based on our cyanocarbon chemistry. A key issue with the synthetic efforts was being able to link the kinetics of release with the size of the substituents as it was difficult to develop a low molecular weight

  5. Carbon dioxide recycling

    The recycling of carbon dioxide to methanol and dimethyl ether is seen to offer a substantial route to renewable and environmentally carbon neutral fuels. One of the authors has championed the “Methanol Economy" in articles and a book. By recycling ambient CO2, the authors argue ...

  6. Water Recycling in Australia

    Ross Young

    2011-09-01

    Full Text Available Australia is the driest inhabited continent on earth and, more importantly, experiences the most variable rainfall of all the continents on our planet. The vast majority of Australians live in large cities on the coast. Because wastewater treatments plants were all located near the coast, it was thought that large scale recycling would be problematic given the cost of infrastructure and pumping required to establish recycled water schemes. This all changed when Australia experienced a decade of record low rainfall and water utilities were given aggressive targets to increase the volume of water recycled. This resulted in recycled water being accepted as a legitimate source of water for non-drinking purposes in a diversified portfolio of water sources to mitigate climate risk. To ensure community support for recycled water, Australia lead the world in developing national guidelines for the various uses of recycled water to ensure the protection of public health and the environment. Australia now provides a great case study of the developments in maximizing water recycling opportunities from policy, regulatory and technological perspectives. This paper explores the evolution in thinking and how approaches to wastewater reuse has changed over the past 40 years from an effluent disposal issue to one of recognizing wastewater as a legitimate and valuable resource. Despite recycled water being a popular choice and being broadly embraced, the concept of indirect potable reuse schemes have lacked community and political support across Australia to date.

  7. AIRCRAFT INDUSTRY WASTEWATER RECYCLING

    The feasibility of recycling certain categories of water used in the manufacture of airplanes was demonstrated. Water in four categories was continuously recycled in 380-liter (100-gallon) treatment plants; chemical process rinse water, dye-penetrant crack-detection rinse water, ...

  8. The Fermilab recycler ring

    Martin Hu

    2001-07-24

    The Fermilab Recycler is a permanent magnet storage ring for the accumulation of antiprotons from the Antiproton Source, and the recovery and cooling of the antiprotons remaining at the end of a Tevatron store. It is an integral part of the Fermilab III luminosity upgrade. The following paper describes the design features, operational and commissioning status of the Recycler Ring.

  9. Facile synthesis and excellent recyclable photocatalytic activity of pine cone-like Fe3O4@Cu2O/Cu porous nanocomposites.

    Wang, Haisheng; Hu, Yongan; Jiang, Yang; Qiu, Lingguang; Wu, Haibin; Guo, Ben; Shen, Yuhua; Wang, Yang; Zhu, Ling; Xie, Anjian

    2013-04-14

    L-Cys-modified Fe3O4 was first prepared by a one-step partially-reduced method under mild conditions. Then, novel pine cone-like Fe3O4@Cu2O/Cu nanocomposites (NCs) with photomagnetic difunction were successfully synthesized via a one-pot solvothermal method on Fe3O4 without any additional linker or reducer. The average diameter of the as-synthesized products was about 4 μm, and the products were orderly assembled into many sheets with an average thickness of ~100 nm, possessing a porous structure. A possible formation mechanism of Fe3O4@Cu2O/Cu NCs involving interfacial recognization of ions, nucleation, aggregation, in situ transformation from Cu2O to Cu and Ostwald ripening process is proposed. The pine cone-like porous composites show excellent photocatalytic activity such that MO degradation efficiency is about 96% at an irradiation time of 20 min under visible light. Also, the composites present higher stability than Fe3O4@Cu2O and do not exhibit any significant loss after five recycles for the photodegradation of MO. The above results demonstrate that Cu could improve the photocatalytic activity of NCs and also inhibit the photocorrosion behavior of NCs. These novel Fe3O4@Cu2O/Cu composite materials are ideal candidates in water treatment and environmental cleaning as well as in magnetic applications, etc. PMID:23380894

  10. Two-dimensional gold nanostructures with high activity for selective oxidation of carbon–hydrogen bonds

    Wang, Liang

    2015-04-22

    Efficient synthesis of stable two-dimensional (2D) noble metal catalysts is a challenging topic. Here we report the facile synthesis of 2D gold nanosheets via a wet chemistry method, by using layered double hydroxide as the template. Detailed characterization with electron microscopy and X-ray photoelectron spectroscopy demonstrates that the nanosheets are negatively charged and [001] oriented with thicknesses varying from single to a few atomic layers. X-ray absorption spectroscopy reveals unusually low gold–gold coordination numbers. These gold nanosheets exhibit high catalytic activity and stability in the solvent-free selective oxidation of carbon–hydrogen bonds with molecular oxygen.

  11. Hydrogen over helium enhancement in successive solar flare particle events from the same active region

    Briggs, P. R.; Armstrong, T. P.; Krimigis, S. M.

    1979-01-01

    An analysis of all of the identified solar-flare-associated energetic particle events in the 1972-1975 period observed with instruments aboard the IMP 7 and IMP 8 satellites has revealed at least eight occasions when more than one particle-producing flare occurred within the same McMath active plage region during its transit of the visible solar disk. A strong tendency for second flares to produce hydrogen over helium (p/alpha) enhanced energetic particle fluxes when compared with the first flare in the 1.8-10.0 MeV per nucleon range emerged in these multiflare regions. The p/alpha enhancement is apparently transient, and for flares separated by at least about 100 hours the p/alpha ratio tends toward its preflare value. It is suggested that the substrate plasma in an active region may be enriched prior to a flare in elements heavier than hydrogen and the composition may not be significantly altered during subsequent acceleration, escape, and propagation. Thus, the preflare history of the active region must be added to the list of factors influencing observed solar-particle-event composition.

  12. Effect of pH and temperature on acidogenic and hydrogenic activities of glucose-degrading bio-granules

    2002-01-01

    Series batch experiments were made to investigate the influences of pH and temperature on the activi-ty of acidogenus and acidogenus in glucose-degrading bacteria cultured in an UASB ( up-flow anaerobic sludgeblanket) reactor for glucose fermentation and hydrogen production. The bacteria exhibited different capability torecover to produce hydrogen at different initial pH and temperature. Hydrogen production, VFA production,COD removal and COD balance were measured at different pH and 20, 37℃ respectively with the same glucoseand VSS in vials. Results showed that there are different influences on the activity of acidogenic bacteria at var-ied pH and result in a variety of amount of hydrogen production, specific hydrogen production and VFA produc-tion, etc. Through the present study, when nonmalized to the weight of VSS, a maximal biogas and hydrogenproduction of 1 717.1 ml/g and 870.0 ml/g were obtained when pH equals 9 at 37 ℃ and 679.00 ml/g of bio-gas, 246. 35 ml/g of hydrogen were also got when pH equals 5 at 20 ℃ respectively. The maximal specific hy-drogen production (SHA) was 116. 56 ml/h, g around 8 of pH value at 37 ℃ and 6. 46 ml/h, g around 4 of pHvalue at 20 ℃, which were obtained by calculating the slope of the accumulated hydrogen gas via time. Butyricacid fermentation was important for hydrogen production. Large quantity of unknown COD was found in the vialswhen a small quantity of bio-gas was produced, but relative less unknown COD was determined when there waslarge quantity of hydrogen produced. This revealed a better engineering foreground for application of hydrogenbio-production.

  13. Status of plutonium recycle from mixed oxide fuel fabrication wastes (U,Pu)O2 facility activities

    Within the specific subject of mixed oxides corresponding to the Fuel Cycle activities performed at CNEA, the recovery of plutonium from wastes originated during tests and pre-fabrication stages is performed. (author)

  14. Final Report for the DOE-BES Program Mechanistic Studies of Activated Hydrogen Release from Amine-Boranes

    Larry G. Sneddon; R. Thomas Baker

    2013-01-13

    Effective storage of hydrogen presents one of the most significant technical gaps to successful implementation of the hydrogen economy, particularly for transportation applications. Amine boranes, such as ammonia borane H3NBH3 and ammonia triborane H3NB3H7, have been identified as promising, high-capacity chemical hydrogen storage media containing potentially readily released protic (N-H) and hydridic (B-H) hydrogens. At the outset of our studies, dehydrogenation of ammonia borane had been studied primarily in the solid state, but our DOE sponsored work clearly demonstrated that ionic liquids, base-initiators and/or metal-catalysts can each significantly increase both the rate and extent of hydrogen release from amine boranes under moderate conditions. Our studies also showed that depending upon the activation method, hydrogen release from amine boranes can occur by very different mechanistic steps and yield different types of spent-fuel materials. The fundamental understanding that was developed during this grant of the pathways and controlling factors for each of these hydrogen-release mechanisms is now enabling continuing discovery and optimization of new chemical-hydride based hydrogen storage systems.

  15. Florida Hydrogen Initiative

    Block, David L

    2013-06-30

    monitoring at any facility engaged in transport, handling and use of hydrogen. Development of High Efficiency Low Cost Electrocatalysts for Hydrogen Production and PEM Fuel Cell Applications ? M. Rodgers, Florida Solar Energy Center The objective of this project was to decrease platinum usage in fuel cells by conducting experiments to improve catalyst activity while lowering platinum loading through pulse electrodeposition. Optimum values of several variables during electrodeposition were selected to achieve the highest electrode performance, which was related to catalyst morphology. Understanding Mechanical and Chemical Durability of Fuel Cell Membrane Electrode Assemblies ? D. Slattery, Florida Solar Energy Center The objective of this project was to increase the knowledge base of the degradation mechanisms for membranes used in proton exchange membrane fuel cells. The results show the addition of ceria (cerium oxide) has given durability improvements by reducing fluoride emissions by an order of magnitude during an accelerated durability test. Production of Low-Cost Hydrogen from Biowaste (HyBrTec?) ? R. Parker, SRT Group, Inc., Miami, FL This project developed a hydrogen bromide (HyBrTec?) process which produces hydrogen bromide from wet-cellulosic waste and co-produces carbon dioxide. Eelectrolysis dissociates hydrogen bromide producing recyclable bromine and hydrogen. A demonstration reactor and electrolysis vessel was designed, built and operated. Development of a Low-Cost and High-Efficiency 500 W Portable PEMFC System ? J. Zheng, Florida State University, H. Chen, Bing Energy, Inc. The objectives of this project were to develop a new catalyst structures comprised of highly conductive buckypaper and Pt catalyst nanoparticles coated on its surface and to demonstrate fuel cell efficiency improvement and durability and cell cost reductions in the buckypaper based electrodes. Development of an Interdisciplinary Hydrogen and Fuel Cell Technology Academic Program ? J

  16. Molecular hydrogen: an energy source for bacterial activity in nuclear waste disposal

    Document available in extended abstract form only. Hydrogen is a common product of microbial metabolism, large number of bacteria are able to use it as energetic substrate in subsurface ecosystems. Moreover H2 is known as one of the most energetic substrates for deep subsurface ecosystem. It could be produced in different ways mainly volcanic activity (basalts iron rich volcanic rocks) or natural radiolysis of water or even fermentation. The millimolar concentrations of H2 observed in the ground waters are consistent with the activity of a large variety of hydrogen-oxidising bacteria as described in the following Table. Electron acceptors are identified as O2, CO2, NO3, SO4 or Fe+++. Aerobic, anaerobic, obligate and facultative autotrophs are included. Numerous of these bacteria are thermophilic bacteria. This bacterial activity leads to the production of methane, acetate, nitrogen, hydrogen sulphur or ferrous oxides. In anoxic environments, H2 concentrations are governed by microbial metabolism. In most cases, H2 producing microorganisms are thermodynamically controlled by the abundance of H2, and survive thanks to H2 consumers, a metabolism called inter-species H2 transfer. Metabolism of H2 is catalysed by hydrogenase as cytoplasmic enzymes or membrane bound enzymes. Several situations of H2 production will occur in nuclear waste repository: - Radiolysis of water. - Radiolysis of organic matter (such as bitumen, in case of B waste), H2 production due to gamma radiolysis of bitumen is evaluated to 1 L H2 /kg of bitumen /MGy. - Corrosion of metal containers (in deaerated solutions). Large amount of H2 are predicted in some situations, and will select the development of hydrogen species. Then, aerobic hydrogen bacteria oxidising hydrogen could be found in basins containing irradiating waste, or during the oxic period of storage, denitrifying bacteria or sulfate reducing bacteria will develop near the bitumen waste. Groundwater of the Callovo-Oxfordian will support

  17. The value and feasibility of proactive recycling

    Photovoltaics (PV) technology has definite environmental advantages over competing electricity generation technologies, and so far these advantages have driven market penetration. The PV industry follows a pro-active approach to preserve its safe and environmentally friendly nature. Industrial ecology considerations raise the issue of what to do with the PV modules at the end of their useful life. One option is recycling. This paper discusses the value of proactive recycling and compares several alternatives. copyright 1999 American Institute of Physics

  18. The value and feasibility of proactive recycling

    Fthenakis, V. M.; Moskowitz, P. D.

    1999-03-01

    Photovoltaics (PV) technology has definite environmental advantages over competing electricity generation technologies, and so far these advantages have driven market penetration. The PV industry follows a pro-active approach to preserve its safe and environmentally friendly nature. Industrial ecology considerations raise the issue of what to do with the PV modules at the end of their useful life. One option is recycling. This paper discusses the value of proactive recycling and compares several alternatives.

  19. Iron- and Cobalt-Catalyzed Alkene Hydrogenation: Catalysis with Both Redox-Active and Strong Field Ligands.

    Chirik, Paul J

    2015-06-16

    The hydrogenation of alkenes is one of the most impactful reactions catalyzed by homogeneous transition metal complexes finding application in the pharmaceutical, agrochemical, and commodity chemical industries. For decades, catalyst technology has relied on precious metal catalysts supported by strong field ligands to enable highly predictable two-electron redox chemistry that constitutes key bond breaking and forming steps during turnover. Alternative catalysts based on earth abundant transition metals such as iron and cobalt not only offer potential environmental and economic advantages but also provide an opportunity to explore catalysis in a new chemical space. The kinetically and thermodynamically accessible oxidation and spin states may enable new mechanistic pathways, unique substrate scope, or altogether new reactivity. This Account describes my group's efforts over the past decade to develop iron and cobalt catalysts for alkene hydrogenation. Particular emphasis is devoted to the interplay of the electronic structure of the base metal compounds and their catalytic performance. First generation, aryl-substituted pyridine(diimine) iron dinitrogen catalysts exhibited high turnover frequencies at low catalyst loadings and hydrogen pressures for the hydrogenation of unactivated terminal and disubstituted alkenes. Exploration of structure-reactivity relationships established smaller aryl substituents and more electron donating ligands resulted in improved performance. Second generation iron and cobalt catalysts where the imine donors were replaced by N-heterocyclic carbenes resulted in dramatically improved activity and enabled hydrogenation of more challenging unactivated, tri- and tetrasubstituted alkenes. Optimized cobalt catalysts have been discovered that are among the most active homogeneous hydrogenation catalysts known. Synthesis of enantiopure, C1 symmetric pyridine(diimine) cobalt complexes have enabled rare examples of highly enantioselective

  20. Ni(0-CMC-Na Nickel Colloids in Sodium Carboxymethyl-Cellulose: Catalytic Evaluation in Hydrogenation Reactions

    Abdallah Karim

    2011-01-01

    Full Text Available A recyclable catalyst, Ni(0-CMC-Na, composed of nickel colloids dispersed in a water soluble bioorganic polymer, sodium carboxymethylcellulose (CMC-Na, was synthesized by a simple procedure from readily available reagents. The catalyst thus obtained is stable and highly active in alkene hydrogenations.

  1. Ni(0)-CMC-Na Nickel Colloids in Sodium Carboxymethyl-Cellulose: Catalytic Evaluation in Hydrogenation Reactions

    Abdallah Karim; Larbi El Firdoussi; Issam Houssini; Mustapha Ait Ali; M. Carmen Puerta; Mohamed Anouar Harrad; Pedro Valerga

    2011-01-01

    A recyclable catalyst, Ni(0)-CMC-Na, composed of nickel colloids dispersed in a water soluble bioorganic polymer, sodium carboxymethylcellulose (CMC-Na), was synthesized by a simple procedure from readily available reagents. The catalyst thus obtained is stable and highly active in alkene hydrogenations.

  2. Active Sites Implanted Carbon Cages in Core-Shell Architecture: Highly Active and Durable Electrocatalyst for Hydrogen Evolution Reaction.

    Zhang, Huabin; Ma, Zuju; Duan, Jingjing; Liu, Huimin; Liu, Guigao; Wang, Tao; Chang, Kun; Li, Mu; Shi, Li; Meng, Xianguang; Wu, Kechen; Ye, Jinhua

    2016-01-26

    Low efficiency and poor stability are two major challenges we encounter in the exploration of non-noble metal electrocatalysts for the hydrogen evolution reaction (HER) in both acidic and alkaline environment. Herein, the hybrid of cobalt encapsulated by N, B codoped ultrathin carbon cages (Co@BCN) is first introduced as a highly active and durable nonprecious metal electrocatalysts for HER, which is constructed by a bottom-up approach using metal organic frameworks (MOFs) as precursor and self-sacrificing template. The optimized catalyst exhibited remarkable electrocatalytic performance for hydrogen production from both both acidic and alkaline media. Stability investigation reveals the overcoating of carbon cages can effectively avoid the corrosion and oxidation of the catalyst under extreme acidic and alkaline environment. Electrochemical active surface area (EASA) evaluation and density functional theory (DFT) calculations revealed that the synergetic effect between the encapsulated cobalt nanoparticle and the N, B codoped carbon shell played the fundamental role in the superior HER catalytic performance. PMID:26649629

  3. Simulation of heat and mass transfer in activated carbon tank for hydrogen storage

    Xiao, Jinsheng [School of Automotive Engineering, Wuhan University of Technology, Hubei 430070 (China); State Key Laboratory of Advanced Technology for Materials Synthesis and Progressing, Wuhan University of Technology, Hubei 430070 (China); Hydrogen Research Institute, Universite du Quebec a Trois-Rivieres, Trois-Rivieres, QC G9A 5H7 (Canada); Tong, Liang [School of Automotive Engineering, Wuhan University of Technology, Hubei 430070 (China); Department of Mechanical and Automotive Engineering, Huaxia College, Wuhan University of Technology, Hubei 430070 (China); Deng, Caihua [School of Automotive Engineering, Wuhan University of Technology, Hubei 430070 (China); Benard, Pierre; Chahine, Richard [Hydrogen Research Institute, Universite du Quebec a Trois-Rivieres, Trois-Rivieres, QC G9A 5H7 (Canada)

    2010-08-15

    The charging process of hydrogen storage tank based on bed of activated carbon in a steel container at room temperature (295 K) and medium storage pressure (10 MPa) is simulated with an axisymmetric geometry model using the finite volume commercial solver Fluent. The mass flux profile at the entrance is established using user-defined functions (UDFs). The heat and mass transfer processes in the cylindrical steel tank packed with activated carbon are discussed considering the influence of viscous resistance and inertial resistance of the porous media. The velocity distribution and its effect on the temperature distribution are analyzed. The effects of the flow rate at the inlet and of the adsorption factor on the charging process are studied. A computational fluid dynamics (CFD) approach based on finite volume simulations is used. Results show that the temperature near the bottom of the tank is higher than that at the entrance, temperature in the center of the tank is higher than that near the wall and rises somewhat faster along the axial compared to the radial direction. The highest hydrogen absolute adsorption occurs at the entrance of the tank. A good agreement is found between the simulation results and the available experimental data. The maximum magnitude of the axial velocity is much higher than that of the radial component, resulting in more heat energy transfer along the axial direction than radial direction. In addition, the pressure reaches equilibrium earlier when the mass flow is higher, and the temperature reaches a maximum value faster. (author)

  4. Hydrogen sulfide raises cytosolic calcium in neurons through activation of L-type Ca2+ channels.

    García-Bereguiaín, Miguel Angel; Samhan-Arias, Alejandro Khalil; Martín-Romero, Francisco Javier; Gutiérrez-Merino, Carlos

    2008-01-01

    Hydrogen sulfide (H(2)S) concentration can be maintained in cell cultures within the range reported for rat brain by repetitive pulses of sodium hydrogen sulfide. Less than 2 h exposure to H(2)S concentrations within 50 and 120 microM (i.e., within the upper segment of the reported physiological range of H(2)S in rat brain), produces a large shift of the intracellular calcium homeostasis in cerebellar granule neurons (CGN) in culture, leading to a large and sustained increase of cytosolic calcium concentration. Only 1 h exposure to H(2)S concentrations within 100 and 300 microM raises intracellular calcium to the neurotoxic range, with nearly 50% cell death after 2 h. L-type Ca(2+) channels antagonists nimodipine and nifedipine block both the H(2)S-induced rise of cytosolic calcium and cell death. The N-methyl-D-aspartate receptor antagonists (+)-MK-801 and DL-2-amino-5-phosphonovaleric acid afforded a nearly complete protection against H(2)S-induced CGN death and largely attenuated the rise of cytosolic calcium. Thus, H(2)S-induced rise of cytosolic calcium eventually reaches the neurotoxic cytosolic calcium range, leading to glutamate-induced excitotoxic CGN death. The authors conclude that H(2)S is a major modulator of calcium homeostasis in neurons as it induces activation of Ca(2+) entry through L-type Ca(2+) channels, and thereby of neuronal activity. PMID:17956188

  5. Reversible Storage of Hydrogen and Natural Gas in Nanospace-Engineered Activated Carbons

    Romanos, Jimmy; Beckner, Matt; Rash, Tyler; Yu, Ping; Suppes, Galen; Pfeifer, Peter

    2012-02-01

    An overview is given of the development of advanced nanoporous carbons as storage materials for natural gas (methane) and molecular hydrogen in on-board fuel tanks for next-generation clean automobiles. High specific surface areas, porosities, and sub-nm/supra-nm pore volumes are quantitatively selected by controlling the degree of carbon consumption and metallic potassium intercalation into the carbon lattice during the activation process. Tunable bimodal pore-size distributions of sub-nm and supra-nm pores are established by subcritical nitrogen adsorption. Optimal pore structures for gravimetric and volumetric gas storage, respectively, are presented. Methane and hydrogen adsorption isotherms up to 250 bar on monolithic and powdered activated carbons are reported and validated, using several gravimetric and volumetric instruments. Current best gravimetric and volumetric storage capacities are: 256 g CH4/kg carbon and 132 g CH4/liter carbon at 293 K and 35 bar; 26, 44, and 107 g H2/kg carbon at 303, 194, and 77 K respectively and 100 bar. Adsorbed film density, specific surface area, and binding energy are analyzed separately using the Clausius-Clapeyron equation, Langmuir model, and lattice gas models.

  6. Efficient degradation of carbamazepine by easily recyclable microscaled CuFeO2 mediated heterogeneous activation of peroxymonosulfate.

    Ding, Yaobin; Tang, Hebin; Zhang, Shenghua; Wang, Songbo; Tang, Heqing

    2016-11-01

    Microscaled CuFeO2 particles (micro-CuFeO2) were rapidly prepared via a microwave-assisted hydrothermal method and characterized by scanning electron microscopy, X-ray powder diffraction and X-ray photoelectron spectroscopy. It was found that the micro-CuFeO2 was of pure phase and a rhombohedral structure with size in the range of 2.8±0.6μm. The micro-CuFeO2 efficiently catalyzed the activation of peroxymonosulfate (PMS) to generate sulfate radicals (SO4-), causing the fast degradation of carbamazepine (CBZ). The catalytic activity of micro-CuFeO2 was observed to be 6.9 and 25.3 times that of micro-Cu2O and micro-Fe2O3, respectively. The enhanced activity of micro-CuFeO2 for the activation of PMS was confirmed to be attributed to synergistic effect of surface bonded Cu(I) and Fe(III). Sulfate radical was the primary radical species responsible for the CBZ degradation. As a microscaled catalyst, micro-CuFeO2 can be easily recovered by gravity settlement and exhibited improved catalytic stability compared with micro-Cu2O during five successive degradation cycles. Oxidative degradation of CBZ by the couple of PMS/CuFeO2 was effective in the studied actual aqueous environmental systems. PMID:27329789

  7. Removal of Aromatic Pollutant Surrogate from Water by Recyclable Magnetite-Activated Carbon Nanocomposite: An Experiment for General Chemistry

    Furlan, Ping Y.; Melcer, Michael E.

    2014-01-01

    A general chemistry laboratory experiment using readily available chemicals is described to introduce college students to an exciting class of nanocomposite materials. In a one-step room temperature synthetic process, magnetite nanoparticles are embedded onto activated carbon matrix. The resultant nanocomposite has been shown to combine the…

  8. Nanocomposite of MoS2 on ordered mesoporous carbon nanospheres: A highly active catalyst for electrochemical hydrogen evolution

    Bian, Xiaojun; Zhu, Jie; Liao, Lei; Scanlon, Micheál D.; Ge, Peiyu; JI, CHANG; Girault, Hubert H.; Liu, Baohong

    2012-01-01

    An efficient electrocatalyst for hydrogen evolution has been developed based upon in situ reduction of MoS2 on ordered mesoporous carbon nanospheres (MoS2/MCNs). The properties of MoS2/MCNs were characterised by scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. Polarisation curves and electrochemical impedance measurements were obtained for MoS2/MCNs modified glassy carbon electrodes. The MoS2/MCNs exhibit high catalytic activity for hydrogen...

  9. Modulation of Na+/K+ ATPase Activity by Hydrogen Peroxide Generated through Heme in L. amazonensis.

    Nathália Rocco-Machado

    Full Text Available Leishmania amazonensis is a protozoan parasite that occurs in many areas of Brazil and causes skin lesions. Using this parasite, our group showed the activation of Na+/K+ ATPase through a signaling cascade that involves the presence of heme and protein kinase C (PKC activity. Heme is an important biomolecule that has pro-oxidant activity and signaling capacity. Reactive oxygen species (ROS can act as second messengers, which are required in various signaling cascades. Our goal in this work is to investigate the role of hydrogen peroxide (H2O2 generated in the presence of heme in the Na+/K+ ATPase activity of L. amazonensis. Our results show that increasing concentrations of heme stimulates the production of H2O2 in a dose-dependent manner until a concentration of 2.5 μM heme. To confirm that the effect of heme on the Na+/K+ ATPase is through the generation of H2O2, we measured enzyme activity using increasing concentrations of H2O2 and, as expected, the activity increased in a dose-dependent manner until a concentration of 0.1 μM H2O2. To investigate the role of PKC in this signaling pathway, we observed the production of H2O2 in the presence of its activator phorbol 12-myristate 13-acetate (PMA and its inhibitor calphostin C. Both showed no effect on the generation of H2O2. Furthermore, we found that PKC activity is increased in the presence of H2O2, and that in the presence of calphostin C, H2O2 is unable to activate the Na+/K+ ATPase. 100 μM of Mito-TEMPO was capable of abolishing the stimulatory effect of heme on Na+/K+ ATPase activity, indicating that mitochondria might be the source of the hydrogen peroxide production induced by heme. The modulation of L. amazonensis Na+/K+ ATPase by H2O2 opens new possibilities for understanding the signaling pathways of this parasite.

  10. Modulation of Na+/K+ ATPase Activity by Hydrogen Peroxide Generated through Heme in L. amazonensis.

    Rocco-Machado, Nathália; Cosentino-Gomes, Daniela; Meyer-Fernandes, José Roberto

    2015-01-01

    Leishmania amazonensis is a protozoan parasite that occurs in many areas of Brazil and causes skin lesions. Using this parasite, our group showed the activation of Na+/K+ ATPase through a signaling cascade that involves the presence of heme and protein kinase C (PKC) activity. Heme is an important biomolecule that has pro-oxidant activity and signaling capacity. Reactive oxygen species (ROS) can act as second messengers, which are required in various signaling cascades. Our goal in this work is to investigate the role of hydrogen peroxide (H2O2) generated in the presence of heme in the Na+/K+ ATPase activity of L. amazonensis. Our results show that increasing concentrations of heme stimulates the production of H2O2 in a dose-dependent manner until a concentration of 2.5 μM heme. To confirm that the effect of heme on the Na+/K+ ATPase is through the generation of H2O2, we measured enzyme activity using increasing concentrations of H2O2 and, as expected, the activity increased in a dose-dependent manner until a concentration of 0.1 μM H2O2. To investigate the role of PKC in this signaling pathway, we observed the production of H2O2 in the presence of its activator phorbol 12-myristate 13-acetate (PMA) and its inhibitor calphostin C. Both showed no effect on the generation of H2O2. Furthermore, we found that PKC activity is increased in the presence of H2O2, and that in the presence of calphostin C, H2O2 is unable to activate the Na+/K+ ATPase. 100 μM of Mito-TEMPO was capable of abolishing the stimulatory effect of heme on Na+/K+ ATPase activity, indicating that mitochondria might be the source of the hydrogen peroxide production induced by heme. The modulation of L. amazonensis Na+/K+ ATPase by H2O2 opens new possibilities for understanding the signaling pathways of this parasite. PMID:26070143

  11. Universal dependence of hydrogen oxidation and evolution reaction activity of platinum-group metals on pH and hydrogen binding energy

    Zheng, Jie; Sheng, Wenchao; Zhuang, Zhongbin; Xu, Bingjun; Yan, Yushan

    2016-01-01

    Understanding how pH affects the activity of hydrogen oxidation reaction (HOR) and hydrogen evolution reaction (HER) is key to developing active, stable, and affordable HOR/HER catalysts for hydroxide exchange membrane fuel cells and electrolyzers. A common linear correlation between hydrogen binding energy (HBE) and pH is observed for four supported platinum-group metal catalysts (Pt/C, Ir/C, Pd/C, and Rh/C) over a broad pH range (0 to 13), suggesting that the pH dependence of HBE is metal-independent. A universal correlation between exchange current density and HBE is also observed on the four metals, indicating that they may share the same elementary steps and rate-determining steps and that the HBE is the dominant descriptor for HOR/HER activities. The onset potential of CO stripping on the four metals decreases with pH, indicating a stronger OH adsorption, which provides evidence against the promoting effect of adsorbed OH on HOR/HER. PMID:27034988

  12. Performance evaluation of a granular activated carbon-sequencing batch biofilm reactor pilot plant system used in treating real wastewater from recycled paper industry.

    Muhamad, Mohd Hafizuddin; Sheikh Abdullah, Siti Rozaimah; Mohamad, Abu Bakar; Rahman, Rakmi Abdul; Kadhum, Abdul Amir Hasan

    2012-01-01

    A pilot scale granular activated carbon-sequencing batch biofilm reactor with a capacity of 2.2 m3 was operated for over three months to evaluate its performance treating real recycled paper industry wastewater under different operational conditions. In this study, dissolved air floatation (DAF) and clarifier effluents were used as influent sources of the pilot plant. During the course of the study, the reactor was able to biodegrade the contaminants in the incoming recycled paper mill wastewater in terms of chemical oxygen demand (COD), adsorbable organic halides (AOX; specifically 2,4-dichlorophenol (2,4-DCP)) and ammoniacal nitrogen (NH3-N) removal efficiencies at varying hydraulic retention times (HRTs) of 1-3 days, aeration rates (ARs) of 2.1-3.4 m3/min and influent feed concentration of 40-950 mg COD/l. Percentages of COD, 2,4-DCP and NH3-N removals increased with increasing HRT, resulting in more than 90% COD, 2,4-DCP and NH3-N removals at HRT values above two days. Degradation of COD, 2,4-DCP and NH3-N were seriously affected by variation of ARs, which resulted in significant decrease of COD, 2,4-DCP and NH3-N removals by decreasing ARs from 3.4 m3/min to 2.1 m3/min, varying in the ranges of 24-80%, 6-96% and 5-42%, respectively. In comparison to the clarifier effluent, the treatment performance of DAF effluent, containing high COD concentration, resulted in a higher COD removal of 82%. The use of diluted DAF effluent did not improve significantly the COD removal. Higher NH3-N removal efficiency of almost 100% was observed during operation after maintenance shutdown compared to normal operation, even at the same HRT of one day due to the higher dissolved oxygen concentrations (1-7 mg/l), while no significant difference in COD removal efficiency was observed. PMID:22720416

  13. Process evaluation of use of high temperature gas-cooled reactors to an ironmaking system based on active carbon recycling energy system

    Reducing coking coal consumption and CO2 emissions by application of iACRES (ironmaking system based on active carbon recycling energy system) was investigated using process flow modeling to show effectiveness of HTGRs (high temperature gas-cooled reactors) adoption to iACRES. Two systems were evaluated: a SOEC (solid oxide electrolysis cell) system using CO2 electrolysis and a RWGS (reverse water-gas shift reaction) system using RWGS reaction with H2 produced by iodine-sulfur process. Both reduction of the coking coal consumption and CO2 emissions were greater in the RWGS system than those in the SOEC system. It was the reason of the result that excess H2 not consumed in the RWGS reaction was used as reducing agent in the blast furnace as well as CO. Heat balance in the HTGR, SOEC and RWGS modules were evaluated to clarify process components to be improved. Optimization of the SOEC temperature was desired to reduce Joule heat input for high efficiency operation of the SOEC system. Higher H2 production thermal efficiency in the IS process for the RWGS system is effective for more efficient HTGR heat utilization. The SOEC system was able to utilize HTGR heat to reduce CO2 emissions more efficiently by comparing CO2 emissions reduction per unit heat of the HTGR. (author)

  14. Possibility of application of solid oxide electrolysis cell on a smart iron-making process based on an active carbon recycling energy system

    Efficient carbon dioxide (CO2) reduction into carbon monoxide (CO) is required to establish a smart iron-making process based on an active carbon recycling energy system (iACRES). A disk-type solid oxide electrolysis cell (SOEC) was prepared and examined experimentally for application to the CO2 reduction process in iACRES. A SOEC with a cathode|electrolyte|anode structure of Ni-YSZ|YSZ|La0.6Sr0.4Co0.2Fe0.8O3-δ was fabricated. The electrolysis of carbon dioxide was conducted at 800-900°C. A current density of 107.1 mA cm-2 was measured between the cathode and anode at 900°C and at 2.52 V. The production rates of CO and O2 were in agreement with the theoretical values determined using Faraday's law. Evaluation of iACRES using the experimental results indicated that an estimated 0.73 high-temperature gas cooled reactor units as the primary energy source for CO2 reduction and a SOEC surface area of 0.098 km2 were required for the reduction of 30% CO2 in blast furnace gas emitted from a conventional blast furnace. (author)

  15. Pt3Co concave nanocubes: synthesis, formation understanding, and enhanced catalytic activity toward hydrogenation of styrene.

    Wang, Chenyu; Lin, Cuikun; Zhang, Lihua; Quan, Zewei; Sun, Kai; Zhao, Bo; Wang, Feng; Porter, Nathan; Wang, Yuxuan; Fang, Jiye

    2014-02-01

    We report a facile synthesis route to prepare high-quality Pt3Co nanocubes with a concave structure, and further demonstrate that these concave Pt3Co nanocubes are terminated with high-index crystal facets. The success of this preparation is highly dependent on an appropriate nucleation process with a successively anisotropic overgrowth and a preservation of the resultant high-index planes by control binding of oleyl-amine/oleic acid with a fine-tuned composition. Using a hydrogenation of styrene as a model reaction, these Pt3Co concave nanocubes as a new class of nanocatalysts with more open structure and active atomic sites located on their high-index crystallographic planes exhibit an enhanced catalytic activity in comparison with low-indexed surface terminated Pt3Co nanocubes in similar size. PMID:24382713

  16. Catalytic enantioselective OFF ↔ ON activation processes initiated by hydrogen transfer: concepts and challenges.

    Quintard, Adrien; Rodriguez, Jean

    2016-08-18

    Hydrogen transfer initiated processes are eco-compatible transformations allowing the reversible OFF ↔ ON activation of otherwise unreactive substrates. The minimization of stoichiometric waste as well as the unique activation modes provided by these transformations make them key players for a greener future for organic synthesis. Long limited to catalytic reactions that form racemic products, considerable progress on the development of strategies for controlling diastereo- and enantioselectivity has been made in the last decade. The aim of this review is to present the different strategies that enable enantioselective transformations of this type and to highlight how they can be used to construct key synthetic building blocks in fewer operations with less waste generation. PMID:27381644

  17. Platinum-coated copper nanowires with high activity for hydrogen oxidation reaction in base.

    Alia, Shaun M; Pivovar, Bryan S; Yan, Yushan

    2013-09-11

    Platinum (Pt)-coated copper (Cu) nanowires (Pt/CuNWs) are synthesized by the partial galvanic displacement of CuNWs and have a 100 nm diameter and are 25-40 μm length. Pt/CuNWs are studied as a hydrogen oxidation reaction (HOR) catalyst in base along with Cu templated Pt nanotubes (PtNT (Cu)), a 5% Cu monolayer on a bulk polycrystalline Pt electrode (5% ML Cu/BPPt), BPPt, and carbon supported Pt (Pt/C). Comparison of these catalysts demonstrates that the inclusion of Cu benefited the HOR activity of Pt/CuNWs likely by providing compressive strain on Pt; surface Cu further aids in hydroxyl adsorption, thereby improving the HOR activity of Pt/CuNWs. Pt/CuNWs exceed the area and mass exchange current densities of carbon supported Pt by 3.5 times and 1.9 times. PMID:23952885

  18. Importance of surface carbide formation on the activity and selectivity of Pd surfaces in the selective hydrogenation of acetylene

    Yang, Bo; Burch, Robbie; Hardacre, Christopher; Hu, P.; Hughes, Philip

    2016-04-01

    A recent experimental investigation (Kim et al. J. Catal. 306 (2013) 146-154) on the selective hydrogenation of acetylene over Pd nanoparticles with different shapes concluded that Pd(100) showed higher activity and selectivity than Pd(111) for acetylene hydrogenation. However, our recent density functional calculations (Yang et al. J. Catal. 305 (2013) 264-276) observed that the clean Pd(111) surface should result in higher activity and ethylene selectivity compared with the clean Pd(100) surface for acetylene hydrogenation. In the current work, using density functional theory calculations, we find that Pd(100) in the carbide form gives rise to higher activity and selectivity than Pd(111) carbide. These results indicate that the catalyst surface is most likely in the carbide form under the experimental reaction conditions. Furthermore, the adsorption energies of hydrogen atoms as a function of the hydrogen coverage at the surface and subsurface sites over Pd(100) are compared with those over Pd(111), and it is found that the adsorption of hydrogen atoms is always less favoured on Pd(100) over the whole coverage range. This suggests that the Pd(100) hydride surface will be less stable than the Pd(111) hydride surface, which is also in accordance with the experimental results reported.

  19. Exploring the activity of a novel Au/TiC(001) model catalyst towards CO and CO2 hydrogenation

    Asara, Gian Giacomo; Ricart, Josep M.; Rodriguez, Jose A.; Illas, Francesc

    2015-10-01

    Small metallic nanoparticles supported on transition metal carbides exhibit an unexpected high activity towards a series of chemical reactions. In particular, the Au/TiC system has proven to be an excellent catalyst for SO2 decomposition, thiophene hydrodesulfurization, O2 and H2 dissociation and the water gas shift reaction. Recent studies have shown that Au/TiC is a very good catalyst for the reverse water-gas shift (CO2 + H2 → CO + H2O) and CO2 hydrogenation to methanol. The present work further expands the range of applicability of this novel type of systems by exploring the catalytic activity of Au/TiC towards the hydrogenation of CO or CO2 with periodic density functional theory (DFT) calculations on model systems. Hydrogen dissociates easily on Au/TiC but direct hydrogenation of CO to methanol is hindered by very high activation barriers implying that, on this model catalyst, methanol production from CO2 involves the hydrogenation of a HOCO-like intermediate. When dealing with mixtures of syngas (CO/CO2/H2/H2O), CO could be transformed into CO2 through the water gas shift reaction with subsequent hydrogenation of CO2 to methanol.

  20. Facile synthesis, structure and visible light photocatalytic activity of recyclable ZnFe{sub 2}O{sub 4}/TiO{sub 2}

    Zhu, Xiaodi; Zhang, Fan [National Synchrotron Radiation Laboratory, Collaborative Innovation Center of Chemistry for Energy Materials, University of Science and Technology of China, Hefei, Anhui 230029 (China); Wang, Mengjiao [CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026 (China); Ding, Jianjun [National Synchrotron Radiation Laboratory, Collaborative Innovation Center of Chemistry for Energy Materials, University of Science and Technology of China, Hefei, Anhui 230029 (China); CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026 (China); Sun, Song, E-mail: suns@ustc.edu.cn [National Synchrotron Radiation Laboratory, Collaborative Innovation Center of Chemistry for Energy Materials, University of Science and Technology of China, Hefei, Anhui 230029 (China); CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026 (China); Bao, Jun [National Synchrotron Radiation Laboratory, Collaborative Innovation Center of Chemistry for Energy Materials, University of Science and Technology of China, Hefei, Anhui 230029 (China); CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026 (China); Gao, Chen, E-mail: cgao@ustc.edu.cn [National Synchrotron Radiation Laboratory, Collaborative Innovation Center of Chemistry for Energy Materials, University of Science and Technology of China, Hefei, Anhui 230029 (China); CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2014-11-15

    Graphical abstract: - Highlights: • ZnFe{sub 2}O{sub 4}/TiO{sub 2} heterojunction was facilely synthesized by a solution combustion method. • Sponge-like ZnFe{sub 2}O{sub 4}/TiO{sub 2} shows excellent photocatalytic activity and stability. • The structure-to-activity relationship and photocatalytic mechanism were proposed. - Abstract: A kind of sponge-like ZnFe{sub 2}O{sub 4}/TiO{sub 2} composite was facilely synthesized by a solution combustion method. The physicochemical properties, including the crystalline phase, surface morphology, spectral response, photogenerated charge carriers’ separation and transfer efficiency, were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, N{sub 2} adsorption/desorption isotherms, X-ray photoelectron spectroscopy, UV–vis absorption spectroscopy and photoluminescence spectroscopy techniques and analyzed to interpret the relationship between the structure and photocatalytic activity. The sponge-like morphology promotes the adsorption of reaction species as well as functions as a good light harvesting structure for the enhancement of spectral utilization. The heterojunction effectively inhibited the recombination of photogenerated charge carriers. With these synergistic effects, the degradation rate of methylene blue on ZnFe{sub 2}O{sub 4}/TiO{sub 2} was up to 93.2% under visible light irradiation and remained stable even after five consecutive reaction runs. Moreover, owing to the magnetic property, ZnFe{sub 2}O{sub 4}/TiO{sub 2} can be recycled easily. Additionally, a photocatalytic mechanism of ZnFe{sub 2}O{sub 4}/TiO{sub 2} was proposed.

  1. Effects of norms, warm-glow and time use on household recycling

    Halvorsen, Bente

    2004-01-01

    Abstract: The aim of this paper is to quantify the relative importance of motivations based on warm-glow, social and moral norms and cost of time used recycling on household recycling efforts. We also test for crowding-out of intrinsic motivations when recycling is perceived as mandatory. We find that the most important variable increasing household recycling efforts is agreeing that recycling is a pleasant activity in itself, which may be interpreted as a warm-glow effect. The...

  2. Automatic radioactive waste recycling

    The production of a plutonium ingot by calcium reduction process at CEA/Valduc generates a residue called 'slag'. This article introduces the recycling unit which is dedicated to the treatment of slags. The aim is to separate and to recycle the plutonium trapped in this bulk on the one hand, and to generate a disposable waste from the slag on the other hand. After a general introduction of the facilities, some elements will be enlightened, particularly the dissolution step, the filtration and the drying equipment. Reflections upon technological constraints will be proposed, and the benefits of a fully automatic recycling unit of nuclear waste will also be stressed. (authors)

  3. Processing and recycling

    Participants of the meeting reported on materials and methods of industrial waste recycling and waste processing: development of sampling techniques for bulk quantities, characterization of electronic scrap, mechanical-biological treatment of residual wastes, comminution, ultrasonic dispersion of solids, control of particle size, fractionation, mills, wet benefication of heavy minerals from sand dunes, processing of slags and ashes, processing of polypropylene, computerized simulation of processing machines, recycling of photovoltaic Cadmium Telluride thin layer modules, compacting of hard coal, production of AIM (Auto Ignition Materials) pellets for airbags, oxidic solder for conditioning of radioactive wasteshydrocyclons, gasification of biomass, recycling of non-ferrous metals, mechanochemical dechlorination of PCB, dioxins, pentachlorphenol and pesticides, ceramics. (uke)

  4. The Compressor Recycle System

    Barstad, Bjørn Ove

    2010-01-01

    The compressor recycle system is the main focus of this thesis. When the mass flow through a compressor becomes too low, the compressor can plunge into surge. Surge is a term that is used for axisymmetric oscillation through a compressor and is highly unwanted. The recycle system feeds compressed gas back to the intake when the mass flow becomes too low, and thereby act as a safety system.A mathematical model of the recycle system is extended and simulated in SIMULINK. The mathematical model ...

  5. Recycling of Metals

    Damgaard, Anders; Christensen, Thomas Højlund

    2011-01-01

    Metals like iron and aluminium are produced from mineral ore and used for a range of products, some of which have very short lifetimes and thus constitute a major fraction of municipal waste. Packaging in terms of cans, foils and containers are products with a short lifetime. Other products like...... describes briefly how iron and aluminium are produced and how scrap metal is recycled in the industry. Quality requirements and use of recycled products are discussed, as are the resource and environmental issues of metal recycling. Copper and other metals are also found in waste but in much smaller...

  6. Solvent recycle/recovery

    Paffhausen, M.W.; Smith, D.L.; Ugaki, S.N.

    1990-09-01

    This report describes Phase I of the Solvent Recycle/Recovery Task of the DOE Chlorinated Solvent Substitution Program for the US Air Force by the Idaho National Engineering Laboratory, EG G Idaho, Inc., through the US Department of Energy, Idaho Operations Office. The purpose of the task is to identify and test recovery and recycling technologies for proposed substitution solvents identified by the Biodegradable Solvent Substitution Program and the Alternative Solvents/Technologies for Paint Stripping Program with the overall objective of minimizing hazardous wastes. A literature search to identify recycle/recovery technologies and initial distillation studies has been conducted. 4 refs.

  7. A Visible-Light-Active Heterojunction with Enhanced Photocatalytic Hydrogen Generation.

    Adhikari, Shiba P; Hood, Zachary D; More, Karren L; Chen, Vincent W; Lachgar, Abdou

    2016-07-21

    A visible-light-active carbon nitride (CN)/strontium pyroniobate (SNO) heterojunction photocatalyst was fabricated by deposition of CN over hydrothermally synthesized SNO nanoplates by a simple thermal decomposition process. The microscopic study revealed that nanosheets of CN were anchored to the surface of SNO resulting in an intimate contact between the two semiconductors. Diffuse reflectance UV/Vis spectra show that the resulting CN/SNO heterojunction possesses intense absorption in the visible region. The structural and spectral properties endowed the CN/SNO heterojunction with remarkably enhanced photocatalytic activity. Specifically, the photocatalytic hydrogen evolution rate per mole of CN was found to be 11 times higher for the CN/SNO composite compared to pristine CN. The results clearly show that the composite photocatalyst not only extends the light absorption range of SNO but also restricts photogenerated charge-carrier recombination, resulting in significant enhancement in photocatalytic activity compared to pristine CN. The relative band positions of the composite allow the photogenerated electrons in the conduction band of CN to migrate to that of SNO. This kind of charge migration and separation leads to the reduction in the overall recombination rate of photogenerated charge carriers, which is regarded as one of the key factors for the enhanced activity. A plausible mechanism for the enhanced photocatalytic activity of the heterostructured composite is proposed based on observed activity, photoluminescence, time-resolved fluorescence emission decay, electrochemical impedance spectroscopy, and band position calculations. PMID:27282318

  8. Electronic structure and activity of the iron- and nickel-containing catalysts for the hydrogenation of coal

    A. Gyulmaliev

    2013-09-01

    Full Text Available The paper represents the theoretical investigation of the electronic structure of Fe- and Ni-containing catalysts and the consideration of their comparative activity at the hydrogenation of coal organic mass. The electronic structure of FeO, FeS, FeS2, NiO and NiS with the minimum number of atoms of iron and nickel and active complexes with a hydrogen molecule were calculated by non empirical method of Hartri-Fock in SRT 6-311G basis. The comparative catalytic activity of these complexes was evaluated.

  9. Cellular Metabolic Activity and the Oxygen and Hydrogen Stable Isotope Composition of Intracellular Water and Metabolites

    Kreuzer-Martin, H. W.; Hegg, E. L.

    2008-12-01

    Intracellular water is an important pool of oxygen and hydrogen atoms for biosynthesis. Intracellular water is usually assumed to be isotopically identical to extracellular water, but an unexpected experimental result caused us to question this assumption. Heme O isolated from Escherichia coli cells grown in 95% H218O contained only a fraction of the theoretical value of labeled oxygen at a position where the O atom was known to be derived from water. In fact, fewer than half of the oxygen atoms were labeled. In an effort to explain this surprising result, we developed a method to determine the isotope ratios of intracellular water in cultured cells. The results of our experiments showed that during active growth, up to 70% of the oxygen atoms and 50% of the hydrogen atoms in the intracellular water of E. coli are generated during metabolism and can be isotopically distinct from extracellular water. The fraction of isotopically distinct atoms was substantially less in stationary phase and chilled cells, consistent with our hypothesis that less metabolically-generated water would be present in cells with lower metabolic activity. Our results were consistent with and explained the result of the heme O labeling experiment. Only about 40% of the O atoms on the heme O molecule were labeled because, presumably, only about 40% of the water inside the cells was 18O water that had diffused in from the culture medium. The rest of the intracellular water contained 16O atoms derived from either nutrients or atmospheric oxygen. To test whether we could also detect metabolically-derived hydrogen atoms in cellular constituents, we isolated fatty acids from log-phase and stationary phase E. coli and determined the H isotope ratios of individual fatty acids. The results of these experiments showed that environmental water contributed more H atoms to fatty acids isolated in stationary phase than to the same fatty acids isolated from log-phase cells. Stable isotope analyses of

  10. Antibacterial Properties and Mechanism of Activity of a Novel Silver-Stabilized Hydrogen Peroxide.

    Nancy L Martin

    Full Text Available Huwa-San peroxide (hydrogen peroxide; HSP is a NSF Standard 60 (maximum 8 mg/L(-1 new generation peroxide stabilized with ionic silver suitable for continuous disinfection of potable water. Experiments were undertaken to examine the mechanism of HSP against planktonic and biofilm cultures of indicator bacterial strains. Contact/kill time (CT relationships that achieve effective control were explored to determine the potential utility in primary disinfection. Inhibitory assays were conducted using both nutrient rich media and a medium based on synthetic wastewater. Assays were compared for exposures to three disinfectants (HSP, laboratory grade hydrogen peroxide (HP and sodium hypochlorite at concentrations of 20 ppm (therefore at 2.5 and 5 times the NSF limit for HP and sodium hypochlorite, respectively and at pH 7.0 and 8.5 in dechlorinated tap water. HSP was found to be more or equally effective as hypochlorite or HP. Results from CT assays comparing HSP and HP at different bacterial concentrations with neutralization of residual peroxide with catalase suggested that at a high bacterial concentration HSP, but not HP, was protected from catalase degradation possibly through sequestration by bacterial cells. Consistent with this hypothesis, at a low bacterial cell density residual HSP was more effectively neutralized as less HSP was associated with bacteria and therefore accessible to catalase. Silver in HSP may facilitate this association through electrostatic interactions at the cell surface. This was supported by experiments where the addition of mono (K(+ and divalent (Ca(+2 cations (0.005-0.05M reduced the killing efficacy of HSP but not HP. Experiments designed to distinguish any inhibitory effect of silver from that of peroxide in HSP were carried out by monitoring the metabolic activity of established P. aeruginosa PAO1 biofilms. Concentrations of 70-500 ppm HSP had a pronounced effect on metabolic activity while the equivalent

  11. Antibacterial Properties and Mechanism of Activity of a Novel Silver-Stabilized Hydrogen Peroxide.

    Martin, Nancy L; Bass, Paul; Liss, Steven N

    2015-01-01

    Huwa-San peroxide (hydrogen peroxide; HSP) is a NSF Standard 60 (maximum 8 mg/L(-1)) new generation peroxide stabilized with ionic silver suitable for continuous disinfection of potable water. Experiments were undertaken to examine the mechanism of HSP against planktonic and biofilm cultures of indicator bacterial strains. Contact/kill time (CT) relationships that achieve effective control were explored to determine the potential utility in primary disinfection. Inhibitory assays were conducted using both nutrient rich media and a medium based on synthetic wastewater. Assays were compared for exposures to three disinfectants (HSP, laboratory grade hydrogen peroxide (HP) and sodium hypochlorite) at concentrations of 20 ppm (therefore at 2.5 and 5 times the NSF limit for HP and sodium hypochlorite, respectively) and at pH 7.0 and 8.5 in dechlorinated tap water. HSP was found to be more or equally effective as hypochlorite or HP. Results from CT assays comparing HSP and HP at different bacterial concentrations with neutralization of residual peroxide with catalase suggested that at a high bacterial concentration HSP, but not HP, was protected from catalase degradation possibly through sequestration by bacterial cells. Consistent with this hypothesis, at a low bacterial cell density residual HSP was more effectively neutralized as less HSP was associated with bacteria and therefore accessible to catalase. Silver in HSP may facilitate this association through electrostatic interactions at the cell surface. This was supported by experiments where the addition of mono (K(+)) and divalent (Ca(+2)) cations (0.005-0.05M) reduced the killing efficacy of HSP but not HP. Experiments designed to distinguish any inhibitory effect of silver from that of peroxide in HSP were carried out by monitoring the metabolic activity of established P. aeruginosa PAO1 biofilms. Concentrations of 70-500 ppm HSP had a pronounced effect on metabolic activity while the equivalent concentrations of

  12. Synergistic effect of helium and hydrogen for bubble swelling in reduced-activation ferritic/martensitic steel under sequential helium and hydrogen irradiation at different temperatures

    Hu, Wenhui [Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Hubei Nuclear Solid Physics Key Laboratory and School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Guo, Liping, E-mail: guolp@whu.edu.cn [Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Hubei Nuclear Solid Physics Key Laboratory and School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Chen, Jihong; Luo, Fengfeng; Li, Tiecheng [Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Hubei Nuclear Solid Physics Key Laboratory and School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Ren, Yaoyao [Center for Electron Microscopy, Wuhan University, Wuhan 430072 (China); Suo, Jinping; Yang, Feng [State Key Laboratory of Mould Technology, Institute of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2014-04-15

    Highlights: • Helium/hydrogen synergistic effect can increase irradiation swelling of RAFM steel. • Hydrogen can be trapped to the outer surface of helium bubbles. • Too large a helium bubble can become movable. • Point defects would become mobile and annihilate at dislocations at high temperature. • The peak swelling temperature for RAFM steel is 450 °C. - Abstract: In order to investigate the synergistic effect of helium and hydrogen on swelling in reduced-activation ferritic/martensitic (RAFM) steel, specimens were separately irradiated by single He{sup +} beam and sequential He{sup +} and H{sup +} beams at different temperatures from 250 to 650 °C. Transmission electron microscope observation showed that implantation of hydrogen into the specimens pre-irradiated by helium can result in obvious enhancement of bubble size and swelling rate which can be regarded as a consequence of hydrogen being trapped by helium bubbles. But when temperature increased, Ostwald ripening mechanism would become dominant, besides, too large a bubble could become mobile and swallow many tiny bubbles on their way moving, reducing bubble number density. And these effects were most remarkable at 450 °C which was the peak bubble swelling temperature for RAMF steel. When temperature was high enough, say above 450, point defects would become mobile and annihilate at dislocations or surface. As a consequence, helium could no longer effectively diffuse and clustering in materials and bubble formation was suppressed. When temperature was above 500, helium bubbles would become unstable and decompose or migrate out of surface. Finally no bubble was observed at 650 °C.

  13. Synergistic effect of helium and hydrogen for bubble swelling in reduced-activation ferritic/martensitic steel under sequential helium and hydrogen irradiation at different temperatures

    Highlights: • Helium/hydrogen synergistic effect can increase irradiation swelling of RAFM steel. • Hydrogen can be trapped to the outer surface of helium bubbles. • Too large a helium bubble can become movable. • Point defects would become mobile and annihilate at dislocations at high temperature. • The peak swelling temperature for RAFM steel is 450 °C. - Abstract: In order to investigate the synergistic effect of helium and hydrogen on swelling in reduced-activation ferritic/martensitic (RAFM) steel, specimens were separately irradiated by single He+ beam and sequential He+ and H+ beams at different temperatures from 250 to 650 °C. Transmission electron microscope observation showed that implantation of hydrogen into the specimens pre-irradiated by helium can result in obvious enhancement of bubble size and swelling rate which can be regarded as a consequence of hydrogen being trapped by helium bubbles. But when temperature increased, Ostwald ripening mechanism would become dominant, besides, too large a bubble could become mobile and swallow many tiny bubbles on their way moving, reducing bubble number density. And these effects were most remarkable at 450 °C which was the peak bubble swelling temperature for RAMF steel. When temperature was high enough, say above 450, point defects would become mobile and annihilate at dislocations or surface. As a consequence, helium could no longer effectively diffuse and clustering in materials and bubble formation was suppressed. When temperature was above 500, helium bubbles would become unstable and decompose or migrate out of surface. Finally no bubble was observed at 650 °C

  14. Recycling or combustion

    The article discusses problems, solutions and policies within plastic waste management. Recycling is environmentally advantageous but not necessarily macro economically profitable and some solutions in order to overcome this problem are presented

  15. Challenges in plastics recycling

    Pivnenko, Kostyantyn; Jakobsen, L. G.; Eriksen, Marie Kampmann;

    2015-01-01

    undertaken to investigate the factors affecting quality in plastics recycling. The preliminary results showed factors primarily influencing quality of plastics recycling to be polymer cross contamination, presence of additives, non-polymer impurities, and polymer degradation. Deprivation of plastics quality......Recycling of waste plastics still remains a challenging area in the waste management sector. The current and potential goals proposed on EU or regional levels are difficult to achieve, and even to partially fullfil them the improvements in collection and sorting should be considerable. A study was......, with respect to recycling, has been shown to happen throughout the plastics value chain, but steps where improvements may happen have been preliminary identified. Example of Cr in plastic samples analysed showed potential spreading and accumulation of chemicals ending up in the waste plastics. In order...

  16. Engineered Plastics Containing Recycled Rubber

    Dong Yang Wu

    2000-01-01

    @@ 1. Introduction In Australia 10.5 million rubber tyres are discarded annually, representing 120,000 tonnes of wasted rubber resource. Growing local and global concern about the impact of this waste on the environment requires action for the management and recycling of this highly valuable resource through the development of recycling technologies and innovative recycled/recyclable products.

  17. Recycling of Sustainable Co-Firing Fly Ashes as an Alkali Activator for GGBS in Blended Cements

    Yann-Hwang Wu

    2015-02-01

    Full Text Available This study investigates the feasibility of co-firing fly ashes from different boilers, circulating fluidized beds (CFB or stokers as a sustainable material in alkali activators for ground granulated blast-furnace slag (GGBS. The mixture ratio of GGBS and co-firing fly ashes is 1:1 by weight. The results indicate that only CF fly ash of CFB boilers can effectively stimulate the potential characteristics of GGBS and provide strength as an alkali activator. CF fly ash consists of CaO3 (48.5%, SiO2 (21.1%, Al2O3 (13.8%, SO3 (10.06%, Fe2O3 (2.25% and others (4.29%. SA fly ash consists of Al2O3 (19.7%, SiO2 (36.3%, Fe2O3 (28.4% and others (15.6%. SB fly ash consists of Al2O3 (15%, SiO2 (25.4%, Zn (20.6%, SO3 (10.9%, Fe2O3 (8.78% and others (19.32%. The mixtures of SA fly ash and SB fly ash with GGBS, respectively, were damaged in the compressive strength test during seven days of curing. However, the built up strength of the CF fly ash and GGBS mixture can only be maintained for 7–14 days, and the compressive strength achieves 70% of that of a controlled group (cement in hardening cement paste. The strength of blended CF fly ash and GGBS started to decrease after 28 days, and the phenomenon of ettrigite was investigated due to the high levels of sulfur content. The CaO content in sustainable co-firing fly ashes must be higher than a certain percentage in reacting GGBS to ensure the strength of blended cements.

  18. Investigation on the two-stage active magnetic regenerative refrigerator for liquefaction of hydrogen

    Park, Inmyong; Park, Jiho; Jeong, Sangkwon [Korea Advanced Institute of Science and Technology, Daejeon 305-701 (Korea, Republic of); Kim, Youngkwon [Institute for Basic Science, Daejeon 305-811 (Korea, Republic of)

    2014-01-29

    An active magnetic regenerative refrigerator (AMRR) is expected to be useful for hydrogen liquefaction due to its inherent high thermodynamic efficiency. Because the temperature of the cold end of the refrigerator has to be approximately liquid temperature, a large temperature span of the active magnetic regenerator (AMR) is indispensable when the heat sink temperature is liquid nitrogen temperature or higher. Since magnetic refrigerants are only effective in the vicinity of their own transition temperatures, which limit the temperature span of the AMR, an innovative structure is needed to increase the temperature span. The AMR must be a layered structure and the thermophysical matching of magnetic field and flow convection effects is very important. In order to design an AMR for liquefaction of hydrogen, the implementation of multi-layered AMR with different magnetic refrigerants is explored with multi-staging. In this paper, the performance of the multi-layered AMR using four rare-earth compounds (GdNi{sub 2}, Gd{sub 0.1}Dy{sub 0.9}Ni{sub 2}, Dy{sub 0.85}Er{sub 0.15}Al{sub 2}, Dy{sub 0.5}Er{sub 0.5}Al{sub 2}) is investigated. The experimental apparatus includes two-stage active magnetic regenerator containing two different magnetic refrigerants each. A liquid nitrogen reservoir connected to the warm end of the AMR maintains the temperature of the warm end around 77 K. High-pressure helium gas is employed as a heat transfer fluid in the AMR and the maximum magnetic field of 4 T is supplied by the low temperature superconducting (LTS) magnet. The temperature span with the variation of parameters such as phase difference between magnetic field and mass flow rate of magnetic refrigerants in AMR is investigated. The maximum temperature span in the experiment is recorded as 50 K and several performance issues have been discussed in this paper.

  19. Investigation on the two-stage active magnetic regenerative refrigerator for liquefaction of hydrogen

    An active magnetic regenerative refrigerator (AMRR) is expected to be useful for hydrogen liquefaction due to its inherent high thermodynamic efficiency. Because the temperature of the cold end of the refrigerator has to be approximately liquid temperature, a large temperature span of the active magnetic regenerator (AMR) is indispensable when the heat sink temperature is liquid nitrogen temperature or higher. Since magnetic refrigerants are only effective in the vicinity of their own transition temperatures, which limit the temperature span of the AMR, an innovative structure is needed to increase the temperature span. The AMR must be a layered structure and the thermophysical matching of magnetic field and flow convection effects is very important. In order to design an AMR for liquefaction of hydrogen, the implementation of multi-layered AMR with different magnetic refrigerants is explored with multi-staging. In this paper, the performance of the multi-layered AMR using four rare-earth compounds (GdNi2, Gd0.1Dy0.9Ni2, Dy0.85Er0.15Al2, Dy0.5Er0.5Al2) is investigated. The experimental apparatus includes two-stage active magnetic regenerator containing two different magnetic refrigerants each. A liquid nitrogen reservoir connected to the warm end of the AMR maintains the temperature of the warm end around 77 K. High-pressure helium gas is employed as a heat transfer fluid in the AMR and the maximum magnetic field of 4 T is supplied by the low temperature superconducting (LTS) magnet. The temperature span with the variation of parameters such as phase difference between magnetic field and mass flow rate of magnetic refrigerants in AMR is investigated. The maximum temperature span in the experiment is recorded as 50 K and several performance issues have been discussed in this paper

  20. Active Hydrogenation Catalyst with a Structured, Peptide-Based Outer-Coordination Sphere

    Jain, Avijita; Buchko, Garry W.; Reback, Matthew L.; O' Hagan, Molly J.; Ginovska-Pangovska, Bojana; Linehan, John C.; Shaw, Wendy J.

    2012-10-05

    The synthesis, catalytic activity, and structural features of a rhodium-based hydrogenation catalyst containing a phosphine ligand coupled to a 14-residue peptide are reported. Both CD and NMR spectroscopy show that the peptide adopts a helical structure in 1:1:1 TFE/MeCN/H2O that is maintained when the peptide is attached to the ligand and when the ligand is attached to the metal complex. The metal complex hydrogenates aqueous solutions of 3-butenol to 1-butanol at 360 ± 50 turnovers/Rh/h at 294 K. This peptide- based catalyst represents a starting point for developing and characterizing a peptide-based outer-coordination sphere that can be used to introduce enzyme-like features into molecular catalysts. This work was funded by the US DOE Basic Energy Sciences, Chemical Sciences, Geoscience and Biosciences Division (AJ, JCL and WJS), the Office of Science Early Career Research Program through the Office of Basic Energy Sciences (GWB, MLR and WJS). Part of the research was conducted at the W.R. Wiley Environmental Molecular Sciences Laboratory, a national scientific user facility sponsored by U.S. Department of Energy’s Office of Biolog-ical and Environmental Research (BER) program located at Pacific Northwest National Laboratory (PNNL). PNNL is operated by Battelle for the U.S. Department of Energy.

  1. Recycling glass packaging

    Monica Delia DOMNICA; Leila BARDAªUC

    2015-01-01

    From the specialized literature it follows that glass packaging is not as used as other packages, but in some industries are highly needed. Following, two features of glass packaging will become important until 2017: the shape of the glass packaging and glass recycling prospects in Romania. The recycling of glass is referred to the fact that it saves energy, but also to be in compliance with the provisions indicating the allowable limit values for the quantities of lead and cadmium.

  2. Water Recycling in Australia

    Ross Young; Nick Apostolidis; Chris Hertle

    2011-01-01

    Australia is the driest inhabited continent on earth and, more importantly, experiences the most variable rainfall of all the continents on our planet. The vast majority of Australians live in large cities on the coast. Because wastewater treatments plants were all located near the coast, it was thought that large scale recycling would be problematic given the cost of infrastructure and pumping required to establish recycled water schemes. This all changed when Australia experienced a decade ...

  3. The Recycler Electron Cooler

    Shemyakin, A

    2013-01-01

    The Recycler Electron cooler was the first (and so far, the only) cooler working at a relativistic energy ({\\gamma} = 9.5). It was successfully developed in 1995-2004 and was in operation at Fermilab in 2005-2011, providing cooling of antiprotons in the Recycler ring. This paper describes the cooler, difficulties in achieving the required electron beam parameters and the ways to overcome them, cooling measurements, and details of operation.

  4. Geometries and electronic structures of the hydrogenated diamond (100) surface upon exposure to active ions: A first principles study

    Liu, Feng-Bin; Li, Jing-Lin; Chen, Wen-Bin; Cui, Yan; Jiao, Zhi-Wei; Yan, Hong-Juan; Qu, Min; Di, Jie-Jian

    2016-02-01

    To elucidate the effects of physisorbed active ions on the geometries and electronic structures of hydrogenated diamond films, models of HCO 3 - , H3O+, and OH- ions physisorbed on hydrogenated diamond (100) surfaces were constructed. Density functional theory was used to calculate the geometries, adsorption energies, and partial density of states. The results showed that the geometries of the hydrogenated diamond (100) surfaces all changed to different degrees after ion adsorption. Among them, the H3O+ ion affected the geometry of the hydrogenated diamond (100) surfaces the most. This is well consistent with the results of the calculated adsorption energies, which indicated that a strong electrostatic attraction occurs between the hydrogenated diamond (100) surface and H3O+ ions. In addition, electrons transfer significantly from the hydrogenated diamond (100) surface to the adsorbed H3O+ ion, which induces a downward shift in the HOMO and LUMO energy levels of the H3O+ ion. However, for active ions like OH- and HCO 3 - , no dramatic change appears for the electronic structures of the adsorbed ions.

  5. Commentary on the Liquid Metallic Hydrogen Model of the Sun: Insight Relative to Coronal Holes, Sunspots, and Solar Activity

    Robitaille P.-M.

    2013-04-01

    Full Text Available While mankind will always remain unable to sample the interior of the Sun, the presence of sunspots and coronal holes can provide clues as to its subsurface structure. Insight relative to the solar body can also be gained by recognizing that the Sun must exist in the condensed state and support a discrete lattice structure, as required for the production of its continuous spectrum. In this regard, the layered liquid metallic hydrogen lattice advanced as a condensed model of the Sun (Robitaille P.M. Liquid Metallic Hydrogen: A Building Block for the Liquid Sun. Progr. Phys ., 2011, v. 3, 60–74; Robitaille P.M. Liquid Metallic Hydrogen II: A Critical Assessment of Current and Primordial Helium Levels in Sun. Progr. Phys ., 2013, v. 2, 35–47; Robitaille J.C. and Robitaille P.M. Liquid Metallic Hydrogen III. Intercalation and Lattice Exclusion Versus Gravitational Settling and Their Consequences Relative to Internal Structure, Surface Activity, and Solar Winds in the Sun. Progr. Phys ., 2013, v. 2, in press provides the ability to add structure to the solar interior. This constitutes a significant advantage over the gaseous solar models. In fact, a layered liquid metallic hydrogen lattice and the associated intercalation of non-hydrogen elements can help to account for the position of sunspots and coronal holes. At the same time, this model provides a greater understanding of the mechanisms which drive solar winds and activity.

  6. Hydrogen and helium effects on reduced activation Fe-Cr ferrite-martensite and ODS steels

    Malitckii, Evgenii

    2015-01-01

    Significant amounts of hydrogen and helium are generated in the structural materials of the nuclear reactor systems by the interaction of the alloying elements with both fast and thermal neutrons. Hydrogen can also be effectively absorbed by other environmental processes. Helium and hydrogen stabilize the small vacancy clusters and facilitate the further formation of the voids that causes the swelling of the structural steels. At the same time, hydrogen plays an important role in degradation ...

  7. Hydrogen production using thermocatalytic decomposition of methane on Ni30/activated carbon and Ni30/carbon black.

    Srilatha, K; Viditha, V; Srinivasulu, D; Ramakrishna, S U B; Himabindu, V

    2016-05-01

    Hydrogen is an energy carrier of the future need. It could be produced from different sources and used for power generation or as a transport fuel which mainly in association with fuel cells. The primary challenge for hydrogen production is reducing the cost of production technologies to make the resulting hydrogen cost competitive with conventional fuels. Thermocatalytic decomposition (TCD) of methane is one of the most advantageous processes, which will meet the future demand, hence an attractive route for COx free environment. The present study deals with the production of hydrogen with 30 wt% of Ni impregnated in commercially available activated carbon and carbon black catalysts (samples coded as Ni30/AC and Ni30/CB, respectively). These combined catalysts were not attempted by previous studies. Pure form of hydrogen is produced at 850 °C and volume hourly space velocity (VHSV) of 1.62 L/h g on the activity of both the catalysts. The analysis (X-ray diffraction (XRD)) of the catalysts reveals moderately crystalline peaks of Ni, which might be responsible for the increase in catalytic life along with formation of carbon fibers. The activity of carbon black is sustainable for a longer time compared to that of activated carbon which has been confirmed by life time studies (850 °C and 54 sccm of methane). PMID:26233751

  8. Hydrogen permeation measurement of the reduced activation ferritic steel F82H by the vacuum thermo-balance method

    Hydrogen permeation fluxes of the reduced activation ferritic steel F82H were quantitatively measured by a newly proposed method, vacuum thermo-balance method, for a precise estimation of tritium leakage in a fusion reactor. We prepared sample capsules made of F82H, which enclosed hydrogen gas. The hydrogen in the capsules permeated through the capsule wall, and subsequently desorbed from the capsule surface during isothermal heating. The vacuum thermo-balance method allows simultaneous measurement of the hydrogen permeation flux by two independent methods, namely, the net weight reduction of the sample capsule and exhaust gas analysis. Thus the simultaneous measurements by two independent methods increase the reliability of the permeability measurement. When the gas pressure of enclosed hydrogen was 0.8 atm at the sample temperature of 673 K, the hydrogen permeation flux of F82H obtained by the net weight reduction and the exhaust gas analysis was 0.75x1018 (H2/m2s) and 2.2x1018 (H2/m2s), respectively. The ratio of the hydrogen permeation fluxes obtained by the net weight reduction to that measured by the exhaust gas analysis was in the range from 1/4 to 1/1 in this experiment. The temperature dependence of the estimated permeation flux was similar in both methods. Taking the uncertainties of both measurements into consideration, both results are supposed to be consistent. The enhancement of hydrogen permeation flux was observed from the sample of which outer surface was mechanically polished. Through the present experiments, it has been demonstrated that the vacuum thermo-balance method is effective for the measurement of hydrogen permeation rate of F82H. (author)

  9. PET and Recycling

    Funda Sevencan

    2007-08-01

    Full Text Available This review aims to clarify the need of decreasing the environmental effects caused by human and draw attention to the increasing environmental effects of plastics wastes. Plastics consist of organic molecules with high density molecules or polymers. Main resources of plastics are the residue of oil rafineries. Several advantages of plastics, have increased the usage continuously. Polyethylene Terephthalate (PET is the most commonly used plastics. PET is used to protect food, drinking water, fruit juice, alcoholic beverage, and food packing films. By the increasing interest on the environmental effects of plastic wastes, concerns on the recyclable packing materials also grew up. Also the daily use of recyclable containers consisting PET have increased. There are five steps for recycling of plastics. These steps are; using large amounts of plastics, collecting them in a big center, classifying and sorting the plastics, reproducing the polymers and obtaining new products with melted plastics. Providing a healthy recycling of plastics, the consumers should have knowledge and responsibility. The consumer should know what he/she has to do before putting the plastics in the recycling containers. Recycling containers and bags should be placed near the sources of plastic wastes. Consequently, the plastic wastes and environmental problems they cause will be on the agenda in future. [TAF Prev Med Bull. 2007; 6(4: 307-312

  10. Recycling of nonmetallics

    Amey, E.B.; Kelly, T.D.

    1996-01-01

    The first factor determining recyclability is the composition of the material itself. Metals, for example, can be reused with little or no loss in quality. Paper and rubber, by this criterion, are less recyclable. Each time paper is recycled, some cellulose fibers are broken. Shorter fibers can mean weaker paper of perceived lower quality and value. Vulcanizing is an irreversible chemical process that precludes recycling rubber in its original form. Both materials may be reused in other applications often of lower value than the original one. To be recyclable, the discarded material must have a collection infrastructure at the source of waste generation, at a central collection site, or at curbside. The recovered material must also have a market. If it is priced noncompetitively or no market exists, if it does not meet specifications, or if it requires special technology investments which cannot be recovered through future sales, the recovered material may be stockpiled or discarded rather than recycled. ?? 1996 International Association for Mathematical Geology.

  11. Species and Organ Diversity in the Effects of Hydrogen Peroxide on Superoxide Dismutase Activity In Vitro

    Hong-Yan Cheng; Song-Quan Song

    2006-01-01

    Superoxide dismutase (SOD) is ubiquitous in aerobic organisms and constitutes the first link in the enzyme scavenging system of reactive oxygen species. In the present study, species and organ diversity of SOD activity in a solution and in an in-gel assay system, as well as the effects of hydrogen peroxide (H2O2) on SOD activity, were investigated. In a solution assay system, SOD activity of jackfruit root, shoot, leaves, axes, and cotyledons, of maize embryos and endosperms, of mung bean leaves and seeds, of sacred lotus axes and cotyledons, and of rice and wheat leaves was increased by 1-15 mmol/L H2O2. However, SOD activity in rice root and seeds, maize roots and leaves, mung bean roots and shoots, and wheat seeds was decreased by 1-15 mmol/L H2O2. The SOD activity of wheat root and soybean roots, leaves, axes, and cotyledons was increased by 1-4 mmol/L H2O2, but was decreased by concentrations of H2O2 >4 mmol/L. The SOD activity of soybean shoots was not affected by 1-15 mmol/L H2O2. The SOD activity in crude mitochondria of jackfruit,maize, and upas seeds, as well as in purified mitochondria of jackfruit, was also increased by 1-15 mmol/L H2O2. In the in-gel assay system, the SOD in jackfruit cotyledons was comprised of Mn-SOD, Cu/Zn-SOD, and Fe-SOD, the crude mitochondria of jackfruit seeds and maizes embryo was comprised of Mn-SOD and Cu/Zn-SOD, and the crude mitochondria of maize seeds was comprised of Mn-SOD only. In the present study,H2O2 markedly inhibited Cu/Zn-SOD and Fe-SOD activity.

  12. Cold neutron prompt gamma activation analysis, a non-destructive technique for hydrogen level assessment in zirconium alloys

    Highlights: ► Cold Neutron Prompt Gamma Activation Analysis has been performed to detect hydrogen in various Zr alloys. ► CNPGAA is non-destructive and can precisely detect low levels of hydrogen (as low as 5 wt ppm). ► Hydrogen pick-up fraction of ZIRLO samples has been investigated using CNPGAA and Vacuum hot Extraction. ► It is shown that the hydrogen pick-up fraction undergoes significant increase slightly before the weight gain transition. - Abstract: We propose a novel use of a non-destructive technique to quantitatively assess hydrogen concentration in zirconium alloys. The technique, called Cold Neutron Prompt Gamma Activation Analysis (CNPGAA), is based on measuring prompt gamma rays following the absorption of cold neutrons, and comparing the rate of detection of characteristic hydrogen gamma rays to that of gamma rays from matrix atoms. Because the emission is prompt, this method has to be performed in close proximity to a neutron source such as the one at the National Institute of Technology (NIST) Center for Neutron Research. Determination shown here to be simple and accurate, matching the results given by usual destructive techniques such as Vacuum Hot Extraction (VHE), with a precision of ±2 mg kg−1 (or wt ppm). Very low levels of hydrogen (as low as 5 mg kg−1 (wt ppm)) can be detected. Also, it is demonstrated that CNPGAA can be applied sequentially on an individual corrosion coupon during autoclave testing, to measure a gradually increasing hydrogen concentration. Thus, this technique can replace destructive techniques performed on “sister” samples thereby reducing experimental uncertainties.

  13. 活性掺合料再生混凝土抗冻性能试验%Experiment on the frost resistance of active admixture recycled concrete

    陈爱玖; 孙晓培; 张敏; 王静

    2014-01-01

    The concrete engineering is worst affected by frost damage in north area of China.analysis of five factors (slag powder,fly ash,air-entraining agent,polypropylene fiber and recycled coarse aggregate) on the influence law of recycled concrete frost resistance by orthogonal test.Find out the most important influence factors on relative loss modulus and compressive strength of recycled concrete ,by compare the recycled concrete freeze-thaw cycle 0 times and 200 times,loss modulus and compressive strength,then analysis of the mech-anism of recycled concrete.%我国北方地区的混凝土工程是受冻害最严重的地区。采用正交试验法分析矿渣粉、粉煤灰、引气剂、聚丙烯纤维和再生粗骨料对再生混凝土抗冻性的影响规律,即:对比再生混凝土冻融循环次数0、200次的质量损失、相对动弹模量、抗压强度,找出对再生混凝土的相对动弹模量和抗压强度影响最大的因素,并对影响机理进行分析。

  14. Pilot-scale treatability testing -- Recycle, reuse, and disposal of materials from decontamination and decommissioning activities: Soda blasting demonstration

    The US Department of Energy (DOE) is in the process of defining the nature and magnitude of decontamination and decommissioning (D and D) obligations at its sites. With disposal costs rising and available storage facilities decreasing, DOE is exploring and implementing new waste minimizing D and D techniques. Technology demonstrations are being conducted by LMES at a DOE gaseous diffusion processing plant, the K-25 Site, in Oak Ridge, Tennessee. The gaseous diffusion process employed at Oak Ridge separated uranium-235 from uranium ore for use in atomic weapons and commercial reactors. These activities contaminated concrete and other surfaces within the plant with uranium, technetium, and other constituents. The objective of current K-25 D and D research is to make available cost-effective and energy-efficient techniques to advance remediation and waste management methods at the K-25 Site and other DOE sites. To support this objective, O'Brien and Gere tested a decontamination system on K-25 Site concrete and steel surfaces contaminated with radioactive and hazardous waste. A scouring system has been developed that removes fixed hazardous and radioactive surface contamination and minimizes residual waste. This system utilizes an abrasive sodium bicarbonate medium that is projected at contaminated surfaces. It mechanically removes surface contamination while leaving the surface intact. Blasting residuals are captured and dissolved in water and treated using physical/chemical processes. Pilot-scale testing of this soda blasting system and bench and pilot-scale treatment of the generated residuals were conducted from December 1993 to September 1994

  15. Pilot-scale treatability testing -- Recycle, reuse, and disposal of materials from decontamination and decommissioning activities: Soda blasting demonstration

    NONE

    1995-08-01

    The US Department of Energy (DOE) is in the process of defining the nature and magnitude of decontamination and decommissioning (D and D) obligations at its sites. With disposal costs rising and available storage facilities decreasing, DOE is exploring and implementing new waste minimizing D and D techniques. Technology demonstrations are being conducted by LMES at a DOE gaseous diffusion processing plant, the K-25 Site, in Oak Ridge, Tennessee. The gaseous diffusion process employed at Oak Ridge separated uranium-235 from uranium ore for use in atomic weapons and commercial reactors. These activities contaminated concrete and other surfaces within the plant with uranium, technetium, and other constituents. The objective of current K-25 D and D research is to make available cost-effective and energy-efficient techniques to advance remediation and waste management methods at the K-25 Site and other DOE sites. To support this objective, O`Brien and Gere tested a decontamination system on K-25 Site concrete and steel surfaces contaminated with radioactive and hazardous waste. A scouring system has been developed that removes fixed hazardous and radioactive surface contamination and minimizes residual waste. This system utilizes an abrasive sodium bicarbonate medium that is projected at contaminated surfaces. It mechanically removes surface contamination while leaving the surface intact. Blasting residuals are captured and dissolved in water and treated using physical/chemical processes. Pilot-scale testing of this soda blasting system and bench and pilot-scale treatment of the generated residuals were conducted from December 1993 to September 1994.

  16. Recycling of Paper and Cardboard

    Christensen, Thomas Højlund; Damgaard, Anders

    2011-01-01

    waste. Recycling of paper and cardboard production waste and postconsumer waste has a long history in the pulp and paper industry. The recycled material now makes up more than half of the raw material used in European pulp and paper industry (ERPC, 2004). This chapter describes briefly how paper and...... cardboard are produced and how waste paper is recycled in the industry. Quality requirements and use of recycled products are discussed, as are the resource and environmental issues of paper recycling....

  17. Households' recycling efforts

    Bruvoll, Annegrete; Halvorsen, Bente [Research Department, Statistics Norway, 8131 Dep, N-0033 Oslo (Norway); Nyborg, Karine [The Ragnar Frisch Centre of Economic Research, Gaustadalleen 21, N-0349 Oslo (Norway)

    2002-11-01

    Households' recycling effort is often argued to be of an insignificant size. It is also frequently argued that this contribution, if significant, is not a cost to households, since it is voluntary. Thus households' use of time and energy are frequently disregarded in cost-benefit analyses of stricter recycling targets. In this survey, based on 1162 interviews, we find that sorting at source involves significant extra use of time and energy in the households. On average, each of those asked reported that they use close to half an hour a week for cleaning, sorting and transporting recyclable waste. On average, 185 h is used per tonne of waste. Four out of ten reported that they use warm or hot water to clean the materials. When investigating the motives for sorting waste, we find that many perceive sorting as mandatory, while some in fact find it a pleasant activity in itself. Moral motives for sorting at source are also widespread. A majority would prefer that a company took over the sorting if this were possible, and on average, the respondents are willing to pay US$ 20/year for this service.

  18. Mechanism of Sporicidal Activity for the Synergistic Combination of Peracetic Acid and Hydrogen Peroxide.

    Leggett, Mark J; Schwarz, J Spencer; Burke, Peter A; McDonnell, Gerald; Denyer, Stephen P; Maillard, Jean-Yves

    2016-02-01

    There is still great interest in controlling bacterial endospores. The use of chemical disinfectants and, notably, oxidizing agents to sterilize medical devices is increasing. With this in mind, hydrogen peroxide (H2O2) and peracetic acid (PAA) have been used in combination, but until now there has been no explanation for the observed increase in sporicidal activity. This study provides information on the mechanism of synergistic interaction of PAA and H2O2 against bacterial spores. We performed investigations of the efficacies of different combinations, including pretreatments with the two oxidizers, against wild-type spores and a range of spore mutants deficient in the spore coat or small acid-soluble spore proteins. The concentrations of the two biocides were also measured in the reaction vessels, enabling the assessment of any shift from H2O2 to PAA formation. This study confirmed the synergistic activity of the combination of H2O2 and PAA. However, we observed that the sporicidal activity of the combination is largely due to PAA and not H2O2. Furthermore, we observed that the synergistic combination was based on H2O2 compromising the spore coat, which was the main spore resistance factor, likely allowing better penetration of PAA and resulting in the increased sporicidal activity. PMID:26637595

  19. Hydrogen-Activation Mechanism of [Fe] Hydrogenase Revealed by Multi-Scale Modeling

    Finkelmann, Arndt Robert; Reiher, Markus

    2014-01-01

    When investigating the mode of hydrogen activation by [Fe] hydrogenases, not only the chemical reactivity at the active site is of importance but also the large-scale conformational change between the so-called open and closed conformations, which leads to a special spatial arrangement of substrate and iron cofactor. To study H2 activation, a complete model of the solvated and cofactor-bound enzyme in complex with the substrate methenyl-H4MPT+ was constructed. Both the closed and open conformations were simulated with classical molecular dynamics on the 100 ns time scale. Quantum-mechanics/molecular-mechanics calculations on snapshots then revealed the features of the active site that enable the facile H2 cleavage. The hydroxyl group of the pyridinol ligand can easily be deprotonated. With the deprotonated hydroxyl group and the structural arrangement in the closed conformation, H2 coordinated to the Fe center is subject to an ionic and orbital push-pull effect and can be rapidly cleaved with a concerted hydr...

  20. Active and Durable Hydrogen Evolution Reaction Catalyst Derived from Pd-Doped Metal-Organic Frameworks.

    Chen, Jitang; Xia, Guoliang; Jiang, Peng; Yang, Yang; Li, Ren; Shi, Ruohong; Su, Jianwei; Chen, Qianwang

    2016-06-01

    The water electrolysis is of critical importance for sustainable hydrogen production. In this work, a highly efficient and stable PdCo alloy catalyst (PdCo@CN) was synthesized by direct annealing of Pd-doped metal-organic frameworks (MOFs) under N2 atmosphere. In 0.5 M H2SO4 solution, PdCo@CN displays remarkable electrocatalytic performance with overpotential of 80 mV, a Tafel slope of 31 mV dec(-1), and excellent stability of 10 000 cycles. Our studies reveal that noble metal doped MOFs are ideal precursors for preparing highly active alloy electrocatalysts with low content of noble metal. PMID:27112733

  1. Metal doped carbon nanoneedles and effect of carbon organization with activity for hydrogen evolution reaction (HER).

    Araujo, Rafael A; Rubira, Adley F; Asefa, Tewodros; Silva, Rafael

    2016-02-10

    Cellulose nanowhiskers (CNW) from cotton, was prepared by acid hydrolysis and purified using a size selection process to obtain homogeneous samples with average particle size of 270 nm and 85.5% crystallinity. Purified CNW was used as precursor to carbon nanoneedles (CNN) synthesis. The synthesis of CNN loaded with different metals dopants were carried out by a nanoreactor method and the obtained CNNs applied as electrocatalysts for hydrogen evolution reaction (HER). In the carbon nanoneedles synthesis, Ni, Cu, or Fe worked as graphitization catalyst and the metal were found present as dopants in the final material. The used metal appeared to have direct influence on the degree of organization of the particles and also in the surface density of polar groups. It was evaluated the influence of the graphitic organization on the general properties and nickel was found as the more appropriate metal since it leads to a more organized material and also to a high activity toward HER. PMID:26686184

  2. Enhanced electrocatalytic activity of MoSx on TCNQ-treated electrode for hydrogen evolution reaction

    Chang, Yunghuang

    2014-10-22

    Molybdenum sulfide has recently attracted much attention because of its low cost and excellent catalytical effects in the application of hydrogen evolution reaction (HER). To improve the HER efficiency, many researchers have extensively explored various avenues such as material modification, forming hybrid structures or modifying geometric morphology. In this work, we reported a significant enhancement in the electrocatalytic activity of the MoSx via growing on Tetracyanoquinodimethane (TCNQ) treated carbon cloth, where the MoSx was synthesized by thermolysis from the ammonium tetrathiomolybdate ((NH4)2MoS4) precursor at 170 °C. The pyridinic N- and graphitic N-like species on the surface of carbon cloth arising from the TCNQ treatment facilitate the formation of Mo5+ and S2 2- species in the MoSx, especially with S2 2- serving as an active site for HER. In addition, the smaller particle size of the MoSx grown on TCNQ-treated carbon cloth reveals a high ratio of edge sites relative to basal plane sites, indicating the richer effective reaction sites and superior electrocatalytic characteristics. Hence, we reported a high hydrogen evolution rate for MoSx on TCNQ-treated carbon cloth of 6408 mL g-1 cm-2 h-1 (286 mmol g-1 cm-2 h-1) at an overpotential of V = 0.2 V. This study provides the fundamental concepts useful in the design and preparation of transition metal dichalcogenide catalysts, beneficial in the development in clean energy.

  3. Hydrogen activation, diffusion, and clustering on CeO₂(111): a DFT+U study.

    Fernández-Torre, Delia; Carrasco, Javier; Ganduglia-Pirovano, M Verónica; Pérez, Rubén

    2014-07-01

    We present a comprehensive density functional theory+U study of the mechanisms underlying the dissociation of molecular hydrogen, and diffusion and clustering of the resulting atomic species on the CeO2(111) surface. Contrary to a widely held view based solely on a previous theoretical prediction, our results show conclusively that H2 dissociation is an activated process with a large energy barrier ~1.0 eV that is not significantly affected by coverage or the presence of surface oxygen vacancies. The reaction proceeds through a local energy minimum--where the molecule is located close to one of the surface oxygen atoms and the H-H bond has been substantially weaken by the interaction with the substrate--, and a transition state where one H atom is attached to a surface O atom and the other H atom sits on-top of a Ce(4+) ion. In addition, we have explored how several factors, including H coverage, the location of Ce(3+) ions as well as the U value, may affect the chemisorption energy and the relative stability of isolated OH groups versus pair and trimer structures. The trimer stability at low H coverages and the larger upward relaxation of the surface O atoms within the OH groups are consistent with the assignment of the frequent experimental observation by non-contact atomic force and scanning tunneling microscopies of bright protrusions on three neighboring surface O atoms to a triple OH group. The diffusion path of isolated H atoms on the surface goes through the adsorption on-top of an oxygen in the third atomic layer with a large energy barrier of ~1.8 eV. Overall, the large energy barriers for both, molecular dissociation and atomic diffusion, are consistent with the high activity and selectivity found recently in the partial hydrogenation of acetylene catalyzed by ceria at high H2/C2H2 ratios. PMID:25005299

  4. Paper recycling framework, the "Wheel of Fiber".

    Ervasti, Ilpo; Miranda, Ruben; Kauranen, Ilkka

    2016-06-01

    At present, there is no reliable method in use that unequivocally describes paper industry material flows and makes it possible to compare geographical regions with each other. A functioning paper industry Material Flow Account (MFA) that uses uniform terminology and standard definitions for terms and structures is necessary. Many of the presently used general level MFAs, which are called frameworks in this article, stress the importance of input and output flows but do not provide a uniform picture of material recycling. Paper industry is an example of a field in which recycling plays a key role. Additionally, terms related to paper industry recycling, such as collection rate, recycling rate, and utilization rate, are not defined uniformly across regions and time. Thus, reliably comparing material recycling activity between geographical regions or calculating any regional summaries is difficult or even impossible. The objective of this study is to give a partial solution to the problem of not having a reliable method in use that unequivocally describes paper industry material flows. This is done by introducing a new material flow framework for paper industry in which the flow and stage structure supports the use of uniform definitions for terms related to paper recycling. This new framework is termed the Detailed Wheel of Fiber. PMID:26994970

  5. Use of nuclear reactions and ion channeling techniques for depth profiling hydrogen isotopes in solids

    Hydrogen has always played a preeminent role in materials science because it so readily alters the physical and chemical properties of materials. However, it is often difficult to determine its role because it is one of the most elusive constituents to detect. More recently hydrogen detection has become necessary in numerous energy-related fields. In fusion energy one must understand plasma particle (hydrogen isotope) recycling, trapping and reemission, as well as the effects of hydrogen on the materials properties of first wall structures in plasma devices (i.e., hydrogen embrittlement, sputtering, blistering, etc.). In geology the presence of hydrogen in various forms alters the mechanical properties of many minerals in the earth's crust and enters directly into studies of tectonic processes. Evaluation of hydrogen in moon rocks increases our understanding of solar wind activity. In solar energy, hydrogen plays an important role in amorphous silicon used in fabricating solar cells. Detection of hydrogen is clearly important in the fossil fuel area. Many of the conventional elemental analysis techniques are not directly applicable to hydrogen determination and others can only detect hydrogen when it is in combination with other elements (i.e., H2O, OH, etc.). In this paper we discuss the use of ion beam techniques for obtaining quantitative depth information on hydrogen in materials and discuss the application of these techniques to several problems important in some of the areas mentioned

  6. Activation of Aspen Wood with Carbon Dioxide and Phosphoric Acid for Removal of Total Organic Carbon from Oil Sands Produced Water: Increasing the Yield with Bio-Oil Recycling

    Andrei Veksha

    2016-01-01

    Full Text Available Several samples of activated carbon were prepared by physical (CO2 and chemical (H3PO4 activation of aspen wood and tested for the adsorption of organic compounds from water generated during the recovery of bitumen using steam assisted gravity drainage. Total organic carbon removal by the carbon samples increased proportionally with total pore volume as determined from N2 adsorption isotherms at −196 °C. The activated carbon produced by CO2 activation had similar removal levels for total organic carbon from the water (up to 70% to those samples activated with H3PO4, but lower yields, due to losses during pyrolysis and activation. A method to increase the yield when using CO2 activation was proposed and consisted of recycling bio-oil produced from previous runs to the aspen wood feed, followed by either KOH addition (0.48% or air pretreatment (220 °C for 3 h before pyrolysis and activation. By recycling the bio-oil, the yield of CO2 activated carbon (after air pretreatment of the mixture was increased by a factor of 1.3. Due to the higher carbon yield, the corresponding total organic carbon removal, per mass of wood feed, increased by a factor of 1.2 thus improving the overall process efficiency.

  7. Cryo-adsorptive hydrogen storage on activated carbon. I: Thermodynamic analysis of adsorption vessels and comparison with liquid and compressed gas hydrogen storage

    Paggiaro, R.; Polifke, W. [Lehrstuhl fuer Thermodynamik, TU Muenchen, Boltzmannstr. 15, D-85747 Garching (Germany); Benard, P. [Institut de recherche sur l' hydrogene, Universite du Quebec, C.P. 500, Trois-Rivieres, Quebec G9A 5H7 (Canada)

    2010-01-15

    This paper presents a thermodynamic analysis of cryo-adsorption vessels for hydrogen storage. The analysis is carried out with an unsteady lumped model and gives a global assessment of the behavior of the storage system during operation (discharge), dormancy and filling. The adsorbent used is superactivated carbon AX-21 trademark. Cryogenic hydrogen storage, either by compression or adsorption, takes advantage of the effect of temperature on the storage density. In order to store 4.1 kg H{sub 2} in 100 L, a pressure of 750 bar at 298 K is necessary, but only 150 bar at 77 K. The pressure is further reduced to 60 bar if the container is filled with pellets of activated carbon. However, adsorption vessels are submitted to intrinsic thermal effects which considerably influence their dynamic behavior and due to which thermal management is required for smooth operation. In this analysis, among energy balances for filling and discharge processes, the influence of the intrinsic thermal effects during vessel operation is presented. Hydrogen losses during normal operation as well as during long periods of inactivity are also considered. The results are compared to those obtained in low-pressure and high-pressure insulated LH{sub 2} and CH{sub 2} tanks. (author)

  8. Phospholipase A2 activation by hydrogen peroxide during in vitro capacitation of buffalo spermatozoa.

    Shit, Sanjoy; Atreja, S K

    2004-05-01

    Progressively motile, washed buffalo spermatozoa (50 x 10(6) cells in 0.5 ml) were in vitro capacitated in HEPES containing Bovine Gamete Medium 3 (BGM3) in presence of heparin (10 microg/ml), and different concentrations of hydrogen peroxide (10 to 100 microM). Spermatozoa (60%) were capacitated in presence of heparin compared to 56% in presence of 25 microM H2O2 (optimally found suitable for capacitation). The extent of capacitation was measured in terms of acrosome reaction (AR) induced by lysophosphatidyl choline (100 microg/ml). The acrosome reacted cells were counted after triple staining. Catalase (100 microg/ml) significantly reduced the sperm capacitation to 16-18% when added with H2O2, or alone in the capacitation medium. Phospholipase A2 activity of spermatozoa increased linearly up to 50 microM H2O2 concentration included in the assay system. Moreover, significant increase in phospholipase A2 activity was observed after capacitation by both, the heparin and 25 microM H2O2. The activity was always higher in acrosome reacted cells. PMID:15233473

  9. Controlled release and enhanced antibacterial activity of salicylic acid by hydrogen bonding with chitosan☆

    Zujin Yang; Yanxiong Fang; Hongbing Ji

    2016-01-01

    Microcapsules of salicylic acid (SA) with chitosan were prepared by spray drying method. Various analytical methods were used to characterize the nature of microcapsules. Fourier-transform infrared spectroscopy (FTIR) confirmed the presence of intermolecular interactions between chitosan and SA. Particle size analysis showed that the average size of microcapsules ranged from 2 to 20μm. Scanning electron microscopy (SEM) studies indicated that the microspheres were spherical and had a relatively smooth surface. Microbiological assay of antibacterial activity for SA and its microcapsules was measured using different bacterial strains. It was found that the antibacterial activity of SA was improved after the formation of microcapsules. The in vitro release profile showed that the microcapsules could control SA release from 1 h to 4 h. Kinetic studies revealed that the release pattern follows Korsmeyer–Peppas mechanism. Enhanced antibacterial activity of the SA micro-capsules was attributed to the synergistic effects of intermolecular hydrogen-bonding interactions N–H⋯O and O–H⋯O_C between SA and chitosan. It was also confirmed by quantum chemical calculation.

  10. Widely available active sites on Ni2P for electrochemical hydrogen evolution--insights from first principles calculations.

    Hansen, Martin H; Stern, Lucas-Alexandre; Feng, Ligang; Rossmeisl, Jan; Hu, Xile

    2015-04-28

    We present insights into the mechanism and the active site for hydrogen evolution on nickel phosphide (Ni2P). Ni2P was recently discovered to be a very active non-precious hydrogen evolution catalyst. Current literature attributes the activity of Ni2P to a particular site on the (0001) facet. In the present study, using Density Functional Theory (DFT) calculations, we show that several widely available low index crystal facets on Ni2P have better properties for a high catalytic activity. DFT calculations were used to identify moderately bonding nickel bridge sites and nickel hollow sites for hydrogen adsorption and to calculate barriers for the Tafel pathway. The investigated surfaces in this study were the (101̅0), (1̅1̅20), (112̅0), (112̅1) and (0001) facets of the hexagonal Ni2P crystal. In addition to the DFT results, we present experiments on Ni2P nanowires growing along the 〈0001〉 direction, which are shown as efficient hydrogen evolution catalysts. The experimental results add these nanowires to a variety of different morphologies of Ni2P, which are all active for HER. PMID:25812670

  11. Hydrogen inhalation reduced epithelial apoptosis in ventilator-induced lung injury via a mechanism involving nuclear factor-kappa B activation

    Huang, Chien-Sheng [Department of Cardiothoracic Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA (United States); Division of Thoracic Surgery, Department of Surgery, Taipei-Veterans General Hospital and National Yang-Ming University School of Medicine, Taipei, Taiwan (China); Kawamura, Tomohiro; Peng, Ximei [Department of Cardiothoracic Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA (United States); Tochigi, Naobumi [Department of Pathology, University of Pittsburgh Medical Center, PA (United States); Shigemura, Norihisa [Department of Cardiothoracic Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA (United States); Billiar, Timothy R. [Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA (United States); Nakao, Atsunori, E-mail: anakao@imap.pitt.edu [Department of Cardiothoracic Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA (United States); Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA (United States); Toyoda, Yoshiya [Department of Cardiothoracic Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA (United States)

    2011-05-06

    Highlights: {yields} Hydrogen is a regulatory molecule with antiinflammatory and antiapoptotic protective effects. {yields} There is very limited information on the pathways regulated in vivo by the hydrogen. {yields} Antiapoptotic abilities of hydrogen were explained by upregulation of the antiapoptotic gene. {yields} NF{kappa}B activation during hydrogen treatment was correlated with elevated antiapoptotic protein. {yields} NF{kappa}B activation associated with increase Bcl-2 may contribute to cytoprotection of hydrogen. -- Abstract: We recently demonstrated the inhalation of hydrogen gas, a novel medical therapeutic gas, ameliorates ventilator-induced lung injury (VILI); however, the molecular mechanisms by which hydrogen ameliorates VILI remain unclear. Therefore, we investigated whether inhaled hydrogen gas modulates the nuclear factor-kappa B (NF{kappa}B) signaling pathway. VILI was generated in male C57BL6 mice by performing a tracheostomy and placing the mice on a mechanical ventilator (tidal volume of 30 ml/kg or 10 ml/kg without positive end-expiratory pressure). The ventilator delivered either 2% nitrogen or 2% hydrogen in balanced air. NF{kappa}B activation, as indicated by NF{kappa}B DNA binding, was detected by electrophoretic mobility shift assays and enzyme-linked immunosorbent assay. Hydrogen gas inhalation increased NF{kappa}B DNA binding after 1 h of ventilation and decreased NF{kappa}B DNA binding after 2 h of ventilation, as compared with controls. The early activation of NF{kappa}B during hydrogen treatment was correlated with elevated levels of the antiapoptotic protein Bcl-2 and decreased levels of Bax. Hydrogen inhalation increased oxygen tension, decreased lung edema, and decreased the expression of proinflammatory mediators. Chemical inhibition of early NF{kappa}B activation using SN50 reversed these protective effects. NF{kappa}B activation and an associated increase in the expression of Bcl-2 may contribute, in part, to the

  12. Hydrogen inhalation reduced epithelial apoptosis in ventilator-induced lung injury via a mechanism involving nuclear factor-kappa B activation

    Highlights: → Hydrogen is a regulatory molecule with antiinflammatory and antiapoptotic protective effects. → There is very limited information on the pathways regulated in vivo by the hydrogen. → Antiapoptotic abilities of hydrogen were explained by upregulation of the antiapoptotic gene. → NFκB activation during hydrogen treatment was correlated with elevated antiapoptotic protein. → NFκB activation associated with increase Bcl-2 may contribute to cytoprotection of hydrogen. -- Abstract: We recently demonstrated the inhalation of hydrogen gas, a novel medical therapeutic gas, ameliorates ventilator-induced lung injury (VILI); however, the molecular mechanisms by which hydrogen ameliorates VILI remain unclear. Therefore, we investigated whether inhaled hydrogen gas modulates the nuclear factor-kappa B (NFκB) signaling pathway. VILI was generated in male C57BL6 mice by performing a tracheostomy and placing the mice on a mechanical ventilator (tidal volume of 30 ml/kg or 10 ml/kg without positive end-expiratory pressure). The ventilator delivered either 2% nitrogen or 2% hydrogen in balanced air. NFκB activation, as indicated by NFκB DNA binding, was detected by electrophoretic mobility shift assays and enzyme-linked immunosorbent assay. Hydrogen gas inhalation increased NFκB DNA binding after 1 h of ventilation and decreased NFκB DNA binding after 2 h of ventilation, as compared with controls. The early activation of NFκB during hydrogen treatment was correlated with elevated levels of the antiapoptotic protein Bcl-2 and decreased levels of Bax. Hydrogen inhalation increased oxygen tension, decreased lung edema, and decreased the expression of proinflammatory mediators. Chemical inhibition of early NFκB activation using SN50 reversed these protective effects. NFκB activation and an associated increase in the expression of Bcl-2 may contribute, in part, to the cytoprotective effects of hydrogen against apoptotic and inflammatory signaling pathway

  13. COMPARATIVE STUDY OF ANTIBACTERIAL ACTIVITY OF PEROXYDISUCCINIC ACID, HYDROGEN PEROXIDE AND THEIR MIXTURE

    Blazheyevskiy M.Ye.,

    2016-06-01

    Full Text Available Introduction. It is known that reactive oxygen species (ROS generated in vivo by cell aerobic metabolism cause multiple damage in different cell organelles and kill not only obligate anaerobes and microaerophilles, but also aerobes. ROS generated by phagocytes and representatives of normal microflora are an important component of macroorganism defense from most pathogens, which is explained by their ability to damage different biological structures. ROS have high reactivity and let us use them in vitro as effective biocides. Hydrogen peroxide is widely used in many industries, in particular, in medicine and veterinary as antiseptic and disinfectant agent due to its safety for environment and broad spectrum of antimicrobial activity including spore-forming bacteria. However, in the recent years certain decrease of background sensitivity of microorganisms to hydrogen peroxide and occurrence of resistant strains of pathogenic microorganisms to this agent has been noted. The aim of this work is to carry out a comparative study of antimicrobial activity of hydrogen peroxide, peroxydisuccinic acid (PDSA, monoperoxysuccinic acid (MPSA, and mixture of PDSA and hydrogen peroxide (Н2О2. Materials and methods. The substances of peroxydisuccinic acid (PDSA and monoperoxysuccinic acid (MPSA were prepared by well known methods. The following test-strains were used to assess antimicrobial activity of the agents: Staphylococcus aureus АТСС 25923, Escherichia coli АТСС 25922, Pseudomonas aeruginosa АТСС 27853, Pseudomonas aeruginosa АТСС 9027, Basillus сereus АТСС 10702, Basillus сereus АТСС 96, Basillus subtilis АТСС 6633, Proteus vulgaris ATCC 4636, Candida albicans АТСС 885/653, and Candida albicans АТСС 10231. All disinfectant agents were diluted in distilled water at 40 ºС and stirred. The microbial burden was 2∙109 CFU/ml of the medium, and for kinetic studies 105 CFU/ml of the medium, it was standardizing

  14. Recycling of Reinforced Plastics

    Adams, R. D.; Collins, Andrew; Cooper, Duncan; Wingfield-Digby, Mark; Watts-Farmer, Archibald; Laurence, Anna; Patel, Kayur; Stevens, Mark; Watkins, Rhodri

    2014-02-01

    This work has shown is that it is possible to recycle continuous and short fibre reinforced thermosetting resins while keeping almost the whole of the original material, both fibres and matrix, within the recyclate. By splitting, crushing hot or cold, and hot forming, it is possible to create a recyclable material, which we designate a Remat, which can then be used to remanufacture other shapes, examples of plates and tubes being demonstrated. Not only can remanufacturing be done, but it has been shown that over 50 % of the original mechanical properties, such as the E modulus, tensile strength, and interlaminar shear strength, can be retained. Four different forms of composite were investigated, a random mat Glass Fibre Reinforced Plastic (GFRP) bathroom component and boat hull, woven glass and carbon fibre cloth impregnated with an epoxy resin, and unidirectional carbon fibre pre-preg. One of the main factors found to affect composite recyclability was the type of resin matrix used in the composite. Thermoset resins tested were shown to have a temperature range around the Glass Transition Temperature (Tg) where they exhibit ductile behaviour, hence aiding reforming of the material. The high-grade carbon fibre prepreg was found to be less easy to recycle than the woven of random fibre laminates. One method of remanufacturing was by heating the Remat to above its glass transition temperature, bending it to shape, and then cooling it. However, unless precautions are taken, the geometric form may revert. This does not happen with the crushed material.

  15. Integrated recycling technology

    M. Spilka

    2008-11-01

    Full Text Available Purpose: In this article, apart from description and analysis of the exemplary technologies of materials recovery, the general recycling model was proposed.Design/methodology/approach: The proposed model makes possible the identification and second waste processing of various groups of materials on the example of one production plant. The technological process and beginning of the presented model formation waste material and a finish product which is a product or pure raw material necessary to new goods production.Findings: In this article the analysis of methods and principles connected with the recycling were presented. Several technologies nowadays used in the aim of the raw materials recovery and second waste processing were also presented.Research limitations/implications: This model is build on the basis of the recycling technological processes with various groups of materials. The only difference is that in the model technologies are connected in total creating the production plant which realizes the whole recirculation process.Practical implications: Presented in this work the general, universal recycling technology model can be a preamble to starting of many investigations in direction of its practical implication.Originality/value: The integrated recycling technology model is a new approach to waste management making possible a significant waste reduction and minimization of raw materials usage.

  16. Thermocatalytic process for CO.sub.2-free production of hydrogen and carbon from hydrocarbons

    Muradov, Nazim Z.

    2011-08-23

    A novel process and apparatus are disclosed for sustainable CO.sub.2-free production of hydrogen and carbon by thermocatalytic decomposition (dissociation, pyrolysis, cracking) of hydrocarbon fuels over carbon-based catalysts in the absence of air and/or water. The apparatus and thermocatalytic process improve the activity and stability of carbon catalysts during the thermocatalytic process and produce both high purity hydrogen (at least, 99.0 volume %) and carbon, from any hydrocarbon fuel, including sulfurous fuels. In a preferred embodiment, production of hydrogen and carbon is achieved by both internal and external activation of carbon catalysts. Internal activation of carbon catalyst is accomplished by recycling of hydrogen-depleted gas containing unsaturated and aromatic hydrocarbons back to the reactor. External activation of the catalyst can be achieved via surface gasification with hot combustion gases during catalyst heating. The process and apparatus can be conveniently integrated with any type of fuel cell to generate electricity.

  17. Effects and Mechanisms of Mechanical Activation on Hydrogen Sorption/ Desorption of Nanoscale Lithium Nitrides

    Shaw, Leon, L.; Yang, Gary, Z.; Crosby, Kyle; Wwan, Xufei. Zhong, Yang; Markmaitree, Tippawan; Osborn, William; Hu, Jianzhi; Kwak, Ja Hun

    2012-04-26

    The objective of this project is to investigate and develop novel, mechanically activated, nanoscale Li3N-based and LiBH4-based materials that are able to store and release {approx}10 wt% hydrogen at temperatures near 100 C with a plateau hydrogen pressure of less than 10 bar. Four (4) material systems have been investigated in the course of this project in order to achieve the project objective. These 4 systems are (i) LiNH2+LiH, (ii) LiNH2+MgH2, (iii) LiBH4, and (iv) LiBH4+MgH2. The key findings we have obtained from these 4 systems are summarized below. *The thermodynamic driving forces for LiNH2+LiH and LiBH4 systems are not adequate to enable H2 release at temperatures < 100 C. *Hydrogen release in the solid state for all of the four systems is controlled by diffusion, and thus is a slow process. *LiNH2+MgH2 and LiBH4+MgH2 systems, although possessing proper thermodynamic driving forces to allow for H2 release at temperatures < 100 C, have sluggish reaction kinetics because of their diffusion-controlled rate-limiting steps. *Reducing particles to the nanometer length scale (< 50 nm) can improve the thermodynamic driving force to enable H2 release at near ambient temperature, while simultaneously enhancing the reaction kinetics as well as changing the diffusion-controlled rate-limiting step to gas desorption-controlled rate-limiting step. This phenomenon has been demonstrated with LiBH4 and offers the hope that further work along this direction will make one of the material systems, i.e., LiBH4, LiBH4+MgH2 and LiNH2+MgH2, possess the desired thermodynamic properties and rapid H2 uptake/release kinetics for on-board applications. Many of the findings and knowledge gained from this project have been published in archival refereed journal articles [1-15] and are accessible by general public. Thus, to avoid a bulky final report, the key findings and knowledge gained from this project will be succinctly summarized, particularly for those findings and knowledge

  18. Hydrogen peroxide induces activation of insulin signaling pathway via AMP-dependent kinase in podocytes

    Highlights: ► H2O2 activates the insulin signaling pathway and glucose uptake in podocytes. ► H2O2 induces time-dependent changes in AMPK phosphorylation. ► H2O2 enhances insulin signaling pathways via AMPK activation. ► H2O2 stimulation of glucose uptake is AMPK-dependent. -- Abstract: Podocytes are cells that form the glomerular filtration barrier in the kidney. Insulin signaling in podocytes is critical for normal kidney function. Insulin signaling is regulated by oxidative stress and intracellular energy levels. We cultured rat podocytes to investigate the effects of hydrogen peroxide (H2O2) on the phosphorylation of proximal and distal elements of insulin signaling. We also investigated H2O2-induced intracellular changes in the distribution of protein kinase B (Akt). Western blots showed that H2O2 (100 μM) induced rapid, transient phosphorylation of the insulin receptor (IR), the IR substrate-1 (IRS1), and Akt with peak activities at 5 min (Δ 183%, P 2O2>. Furthermore, H2O2 inhibited phosphorylation of the phosphatase and tensin homologue (PTEN; peak activity at 10 min; Δ −32%, P 2O2 on IR phosphorylation by about 40% (from 2.07 ± 0.28 to 1.28 ± 0.12, P 2O2 increased glucose uptake in podocytes (from 0.88 ± 0.04 to 1.29 ± 0.12 nmol/min/mg protein, P 2O2 activated the insulin signaling pathway and glucose uptake via AMPK in cultured rat podocytes. This signaling may play a potential role in the prevention of insulin resistance under conditions associated with oxidative stress.

  19. Hydrogen peroxide mediates Rac1 activation of S6K1

    We previously reported that hydrogen peroxide (H2O2) mediates mitogen activation of ribosomal protein S6 kinase 1 (S6K1) which plays an important role in cell proliferation and growth. In this study, we investigated a possible role of H2O2 as a molecular linker in Rac1 activation of S6K1. Overexpression of recombinant catalase in NIH-3T3 cells led to the drastic inhibition of H2O2 production by PDGF, which was accompanied by a decrease in S6K1 activity. Similarly, PDGF activation of S6K1 was significantly inhibited by transient transfection or stable transfection of the cells with a dominant-negative Rac1 (Rac1N17), while overexpression of constitutively active Rac1 (Rac1V12) in the cells led to an increase in basal activity of S6K1. In addition, stable transfection of Rat2 cells with Rac1N17 dramatically attenuated the H2O2 production by PDGF as compared with that in the control cells. In contrast, Rat2 cells stably transfected with Rac1V12 produced high level of H2O2 in the absence of PDGF, comparable to that in the control cells stimulated with PDGF. More importantly, elimination of H2O2 produced in Rat2 cells overexpressing Rac1V12 inhibited the Rac1V12 activation of S6K1, indicating the possible role of H2O2 as a mediator in the activation of S6K1 by Rac1. However, H2O2 could be also produced via other pathway, which is independent of Rac1 or PI3K, because in Rat2 cells stably transfected with Rac1N17, H2O2 could be produced by arsenite, which has been shown to be a stimulator of H2O2 production. Taken together, these results suggest that H2O2 plays a pivotal role as a mediator in Rac1 activation of S6K1

  20. Indole cyanation via C-H bond activation under catalysis of Ru(Ⅲ)-exchanged NaY zeolite (RuY) as a recyclable catalyst

    Alireza Khorshidi

    2012-01-01

    Selective 3-cyanation of indoles was achieved under heterogeneous catalysis of Ru(Ⅲ)-exchanged NaY zeolite (RuY) as a recyclable catalyst,in combination with K4[Fe(CN)6] as a nontoxic,slow cyanide releasing agent.Under the aforementioned conditions,good yields of the desired products were obtained.

  1. Purdue Hydrogen Systems Laboratory

    Jay P Gore; Robert Kramer; Timothee L Pourpoint; P. V. Ramachandran; Arvind Varma; Yuan Zheng

    2011-12-28

    The Hydrogen Systems Laboratory in a unique partnership between Purdue University's main campus in West Lafayette and the Calumet campus was established and its capabilities were enhanced towards technology demonstrators. The laboratory engaged in basic research in hydrogen production and storage and initiated engineering systems research with performance goals established as per the USDOE Hydrogen, Fuel Cells, and Infrastructure Technologies Program. In the chemical storage and recycling part of the project, we worked towards maximum recycling yield via novel chemical selection and novel recycling pathways. With the basic potential of a large hydrogen yield from AB, we used it as an example chemical but have also discovered its limitations. Further, we discovered alternate storage chemicals that appear to have advantages over AB. We improved the slurry hydrolysis approach by using advanced slurry/solution mixing techniques. We demonstrated vehicle scale aqueous and non-aqueous slurry reactors to address various engineering issues in on-board chemical hydrogen storage systems. We measured the thermal properties of raw and spent AB. Further, we conducted experiments to determine reaction mechanisms and kinetics of hydrothermolysis in hydride-rich solutions and slurries. We also developed a continuous flow reactor and a laboratory scale fuel cell power generation system. The biological hydrogen production work summarized as Task 4.0 below, included investigating optimal hydrogen production cultures for different substrates, reducing the water content in the substrate, and integrating results from vacuum tube solar collector based pre and post processing tests into an enhanced energy system model. An automated testing device was used to finalize optimal hydrogen production conditions using statistical procedures. A 3 L commercial fermentor (New Brunswick, BioFlo 115) was used to finalize testing of larger samples and to consider issues related to scale up

  2. Purdue Hydrogen Systems Laboratory

    The Hydrogen Systems Laboratory in a unique partnership between Purdue University's main campus in West Lafayette and the Calumet campus was established and its capabilities were enhanced towards technology demonstrators. The laboratory engaged in basic research in hydrogen production and storage and initiated engineering systems research with performance goals established as per the USDOE Hydrogen, Fuel Cells, and Infrastructure Technologies Program. In the chemical storage and recycling part of the project, we worked towards maximum recycling yield via novel chemical selection and novel recycling pathways. With the basic potential of a large hydrogen yield from AB, we used it as an example chemical but have also discovered its limitations. Further, we discovered alternate storage chemicals that appear to have advantages over AB. We improved the slurry hydrolysis approach by using advanced slurry/solution mixing techniques. We demonstrated vehicle scale aqueous and non-aqueous slurry reactors to address various engineering issues in on-board chemical hydrogen storage systems. We measured the thermal properties of raw and spent AB. Further, we conducted experiments to determine reaction mechanisms and kinetics of hydrothermolysis in hydride-rich solutions and slurries. We also developed a continuous flow reactor and a laboratory scale fuel cell power generation system. The biological hydrogen production work summarized as Task 4.0 below, included investigating optimal hydrogen production cultures for different substrates, reducing the water content in the substrate, and integrating results from vacuum tube solar collector based pre and post processing tests into an enhanced energy system model. An automated testing device was used to finalize optimal hydrogen production conditions using statistical procedures. A 3 L commercial fermentor (New Brunswick, BioFlo 115) was used to finalize testing of larger samples and to consider issues related to scale up. Efforts

  3. Plasmonic Au nanoparticles embedding enhances the activity and stability of CdS for photocatalytic hydrogen evolution.

    Yu, Guiyang; Wang, Xiang; Cao, Jungang; Wu, Shujie; Yan, Wenfu; Liu, Gang

    2016-02-01

    The activity and stability of CdS for visible-light-driven hydrogen evolution could be significantly enhanced by embedding plasmonic Au nanoparticles. The plasmon resonance energy field of Au nanoparticles could increase the formation rate and lifetime of e(-)/h(+) pairs in CdS semiconductors. PMID:26732587

  4. PROCESS OPTIMIZATION OF TETRA ACETYL ETHYLENE DIAMINE ACTIVATED HYDROGEN PEROXIDE BLEACHING OF POPULUS NIGRA CTMP

    Qiang Zhao

    2010-02-01

    Full Text Available To enhance the bleaching efficiency, the activator of tetra acetyl ethylene diamine (TAED was used in conventional H2O2 bleaching. The H2O2/TAED bleaching system can accelerate the reaction rate and shorten bleaching time at relative low temperature, which can reduce the production cost. In this research, the process with hydrogen peroxide activated by TAED bleaching of Populus nigra chemi-thermo mechanical pulp was optimized. Suitable bleaching conditions were confirmed as follows: pulp consistency 10%, bleaching temperature 70oC, bleaching time 60 min when the charge of H2O2 was 4%, NaOH charge 2%, and molar ratio of TAED to H2O2 0.3. The pulp brightness gain reached 23.6% ISO with the optimized bleaching conditions. FTIR analysis indicated that the H2O2/TAED bleaching system can decrease carbonyl group further than that of conventional H2O2 bleaching, which contributed to the higher bleaching efficiency and final brightness. The H2O2/TAED bleaching had stronger oxidation ability on lignin than that of H2O2 bleaching.

  5. Hydrogenated Amorphous Silicon Germanium Active Layer for Top Cell of a Multi Junction Cell Structure.

    Cho, Jaehyun; Iftiquar, S M; Kim, Minbum; Park, Jinjoo; Jung, Junhee; Kim, Jiwoong; Yi, Junsin

    2016-05-01

    Intrinsic hydrogenated amorphous silicon-germanium (a-SiGe:H) alloy is generally used in the bottom cell because of its low band gap. The a-SiGe:H has a higher photo conductivity in comparison to the a-Si:H; thus, it is expected that the a-SiGe:H can show better short circuit current density than that of the a-Si:H based solar cell. Therefore, we optimized a-SiGe:H active layer that can be a suitable choice for the front cell of a multi junction.solar cell. Furthermore, we carried out a comparative study of the solar cells that have a-SiGe:H and a-Si:H as respective active layers. The a-SiGe:H based solar cells show higher short circuit current density, while the a-Si:H based cells show higheropen circuit voltage. The current-voltage characteristics of these cells are as follows: (a) V(oc) = 770 mV, J(sc) = 15.0 mA/cm2, FF = 64.5%, and η = 7.47% for a-SiGe:H based cell; and (b) V(oc) = 826 mV, J(sc) = 13.63 mA/cm2, FF = 72.0%, and η = 8.1% for a-Si:H based cell. PMID:27483837

  6. The Effects of Acute Hydrogen Sulfide Poisoning on Cytochrome P450 Isoforms Activity in Rats

    Xianqin Wang

    2014-01-01

    Full Text Available Hydrogen sulfide (H2S is the second leading cause of toxin related death (after carbon monoxide in the workplace. H2S is absorbed by the upper respiratory tract mucosa, and it causes histotoxic hypoxemia and respiratory depression. Cocktail method was used to evaluate the influences of acute H2S poisoning on the activities of cytochrome P450 isoforms CYP2B6, CYP2D6, CYP3A4, CYP1A2, CYP2C19, and CYP2C9, which were reflected by the changes of pharmacokinetic parameters of six specific probe drugs, bupropion, metoprolol, midazolam, phenacetin, omeprazole, and tolbutamide, respectively. The experimental rats were randomly divided into two groups, control group and acute H2S poisoning group (inhaling 300 ppm for 2 h. The mixture of six probes was given to rats by oral administration and the blood samples were obtained at a series of time points through the caudal vein. The concentrations of probe drugs in rat plasma were measured by LC-MS. The results for acute H2S poisoning and control groups were as follows: there was a statistically significant difference in the AUC and Cmax for bupropion, metoprolol, phenacetin, and tolbutamide, while there was no statistical pharmacokinetic difference for midazolam and omeprazole. Acute H2S poisoning could inhibit the activity of CYP2B6, CYP2D6, CYP1A2, and CYP2C9 in rats.

  7. Hydrogen peroxide sensing and cytotoxicity activity of Acacia lignin stabilized silver nanoparticles.

    Aadil, Keshaw Ram; Barapatre, Anand; Meena, Avtar Singh; Jha, Harit

    2016-01-01

    The study is aimed at detection of hydrogen peroxide (H2O2) using Acacia lignin mediated silver nanoparticles (AGNPs). The synthesis of AGNPs was achieved at conditions optimized as, 3 ml of 0.02% lignin and 1mM silver nitrate incubated for 30 min at 80°C and pH 9. Initial screening of AGNPs was performed by measuring the surface plasmon resonance peak at 410-430 nm using UV-vis spectrophotometer. Transmission electron microscopy, atomic force microscopy, X-ray diffraction and particle size analysis confirmed the spherical shaped face centered cubic structure and 10-50 nm size of AGNPs. The infrared spectroscopy study further revealed that the active functional groups present in lignin were responsible for the reduction of silver ions (Ag(+)) to metallic silver (Ag(0)). Lignin stabilized silver nanoparticles showed good sensitivity and a linear response over wide concentrations of H2O2 (10(-1) to 10(-6)M). Further, the in vitrocytotoxicity activity of the lignin mediated AGNPs (5-500 μg/ml) demonstrated toxicity effects in MCF-7 and A375 cell lines. Thus, lignin stabilized silver nanoparticles based optical sensor for H2O2 could be potentially applied in the determination of reactive oxygen species and toxic chemicals which further expands the importance of lignin stabilized silver nanoparticles. PMID:26434518

  8. The Effect of Recycling in the HL-1M Tokamak

    ZHENGYongzhen

    2002-01-01

    It is often stated that even clean tokamak discharges disrupt at high density. One possibility is that such disruption result from the energy loss arising from hydrogen recycling at the edge of the plasma.this energy loss could lead to a contraction of the current channel and the production of a disruptively unstable configuration.

  9. Energy Efficient Catalytic Activation of Hydrogen peroxide for Green Chemical Processes: Final Report

    Collins, Terrence J.; Horwitz, Colin

    2004-11-12

    A new, highly energy efficient approach for using catalytic oxidation chemistry in multiple fields of technology has been pursued. The new catalysts, called TAML® activators, catalyze the reactions of hydrogen peroxide and other oxidants for the exceptionally rapid decontamination of noninfectious simulants (B. atrophaeus) of anthrax spores, for the energy efficient decontamination of thiophosphate pesticides, for the facile, low temperature removal of color and organochlorines from pulp and paper mill effluent, for the bleaching of dyes from textile mill effluents, and for the removal of recalcitrant dibenzothiophene compounds from diesel and gasoline fuels. Highlights include the following: 1) A 7-log kill of Bacillus atrophaeus spores has been achieved unambiguously in water under ambient conditions within 15 minutes. 2) The rapid total degradation under ambient conditions of four thiophosphate pesticides and phosphonate degradation intermediates has been achieved on treatment with TAML/peroxide, opening up potential applications of the decontamination system for phosphonate structured chemical warfare agents, for inexpensive, easy to perform degradation of stored and aged pesticide stocks (especially in Africa and Asia), for remediation of polluted sites and water bodies, and for the destruction of chemical warfare agent stockpiles. 3) A mill trial conducted in a Pennsylvanian bleached kraft pulp mill has established that TAML catalyst injected into an alkaline peroxide bleach tower can significantly lower color from the effluent stream promising a new, more cost effective, energy-saving approach for color remediation adding further evidence of the value and diverse engineering capacity of the approach to other field trials conducted on effluent streams as they exit the bleach plant. 4) Dibenzothiophenes (DBTs), including 4,6-dimethyldibenzothiophene, the most recalcitrant sulfur compounds in diesel and gasoline, can be completely removed from model gasoline

  10. Combustion Byproducts Recycling Consortium

    Paul Ziemkiewicz; Tamara Vandivort; Debra Pflughoeft-Hassett; Y. Paul Chugh; James Hower

    2008-08-31

    The Combustion Byproducts Recycling Consortium (CBRC) program was developed as a focused program to remove and/or minimize the barriers for effective management of over 123 million tons of coal combustion byproducts (CCBs) annually generated in the USA. At the time of launching the CBRC in 1998, about 25% of CCBs were beneficially utilized while the remaining was disposed in on-site or off-site landfills. During the ten (10) year tenure of CBRC (1998-2008), after a critical review, 52 projects were funded nationwide. By region, the East, Midwest, and West had 21, 18, and 13 projects funded, respectively. Almost all projects were cooperative projects involving industry, government, and academia. The CBRC projects, to a large extent, successfully addressed the problems of large-scale utilization of CCBs. A few projects, such as the two Eastern Region projects that addressed the use of fly ash in foundry applications, might be thought of as a somewhat smaller application in comparison to construction and agricultural uses, but as a novel niche use, they set the stage to draw interest that fly ash substitution for Portland cement might not attract. With consideration of the large increase in flue gas desulfurization (FGD) gypsum in response to EPA regulations, agricultural uses of FGD gypsum hold promise for large-scale uses of a product currently directed to the (currently stagnant) home construction market. Outstanding achievements of the program are: (1) The CBRC successfully enhanced professional expertise in the area of CCBs throughout the nation. The enhanced capacity continues to provide technology and information transfer expertise to industry and regulatory agencies. (2) Several technologies were developed that can be used immediately. These include: (a) Use of CCBs for road base and sub-base applications; (b) full-depth, in situ stabilization of gravel roads or highway/pavement construction recycled materials; and (c) fired bricks containing up to 30%-40% F

  11. Size-Dependent Catalytic Activity of Palladium Nanoparticles Fabricated in Porous Organic Polymers for Alkene Hydrogenation at Room Temperature.

    Mondal, John; Trinh, Quang Thang; Jana, Avijit; Ng, Wilson Kwok Hung; Borah, Parijat; Hirao, Hajime; Zhao, Yanli

    2016-06-22

    Ultrafine palladium nanoparticles (Pd NPs) with 8 and 3 nm sizes were effectively fabricated in triazine functionalized porous organic polymer (POP) TRIA that was developed by nonaqueous polymerization of 2,4,6-triallyoxy-1,3,5-triazine. The Pd NPs encapsulated POP (Pd-POP) was fully characterized using several techniques. Further studies revealed an excellent capability of Pd-POP for catalytic transfer hydrogenation of alkenes at room temperature with superior catalytic performance and high selectivity of desired products. Highly flammable H2 gas balloon at high pressure and temperature used in conventional hydrogenation reactions was not needed in the present synthetic system. Catalytic activity is strongly dependent on the size of encapsulated Pd NPs in the POP. The Pd-POP catalyst with Pd NPs of 8 nm in diameter exhibited higher catalytic activity for alkene hydrogenation as compared with the Pd-POP catalyst encapsulating 3 nm Pd NPs. Computational studies were undertaken to gain insights into different catalytic activities of these two Pd-POP catalysts. High reusability and stability as well as no Pd leaching of these Pd-POP catalysts make them highly applicable for hydrogenation reactions at room temperature. PMID:27258184

  12. Business Plan: Paper Recycling Plant

    Ali, Muhammad; Askari, Sana; Salman, Muhammad; Askari, Sheba

    2008-01-01

    This Business Plan was written for Business Plan competition organized by Ministry of Youth Affairs Government of Pakistan. It explains the paper recycling business, its pros and cons, cost of paper recycling, plant options and feasibility.

  13. 2009 Hydrogen and Fuel Cell Activities, Progress, and Plans: Report to Congress

    None

    2009-01-27

    The Department of Energy is conducting a comprehensive and focused program that fulfills the provisions of Title VIII of the Energy Policy Act of 2005 (EPACT). The Department’s Hydrogen Program addresses the full range of barriers facing the development and deployment of hydrogen and fuel cell technologies.

  14. Characterization of hydrogen in concrete by cold neutron prompt gamma-ray activation analysis and neutron incoherent scattering

    Paul, R.L.; Chen-Mayer, H.H.; Lindstrom, R.M.; Blaauw, M.

    2000-07-01

    A combination of cold neutron prompt gamma-ray activation analysis (PGAA) and neutron incoherent scattering (NIS) has been used for nondestructive characterization of hydrogen as a function of position in slabs of wet concrete of different composition. Hydrogen was determined by PGAA by scanning each sample across of 5 mm diameter neutron beam in 10 mm increments, and measuring the 2223 keV prompt gamma ray. NIS measurements were performed by scanning the samples across a 5 mm diameter neutron beam at 5 mm increments and detecting scattered neutrons. The measurements demonstrate the feasibility of the techniques for 2D compositional mapping of hydrogen and other elements in materials, and indicate the potential of these methods for monitoring the uniformity of drying concrete.

  15. Catalytic activity of Pd-Ni in the oxidation of hydrogen for the safety of nuclear power plant

    Łomot Dariusz

    2016-03-01

    Full Text Available Pd-Ni/Al2O3 systems were investigated in the reaction of hydrogen oxidation in terms of their possible application as catalysts used in passive autocatalytic recombiners (PARs used in nuclear power plants. Testing experiments were carried out in a flowing system at different temperatures and humidity of the reaction mixture. The bimetallic catalysts exhibited higher response to the increase of temperature and higher resistance to inhibit water than the monometallic palladium catalyst. They showed excellent stability during a few tens of hours, similarly, like their monometallic counterpart. Our bimetallic catalysts of hydrogen oxidation can be used as cheaper alternatives to catalysts based on the precious metals in the hydrogen oxidation without loss of their activity over time.

  16. Driving electrocatalytic activity by interface electronic structure control in a metalloprotein hybrid catalyst for efficient hydrogen evolution.

    Behera, Sushant Kumar; Deb, Pritam; Ghosh, Arghya

    2016-08-17

    The rational design of metalloprotein hybrid structures and precise calculations for understanding the role of the interfacial electronic structure in regulating the HER activity of water splitting sites and their microscopic effect for obtaining robust hydrogen evolution possess great promise for developing highly efficient nano-bio hybrid HER catalysts. Here, we employ high-accuracy linear-scaling density functional theory calculations using a near-complete basis set and a minimal parameter implicit solvent model within the self-consistent calculations, on silver (Ag) ions assimilated on bacteriorhodopsin (bR) at specific binding sites. Geometry optimization indicates the formation of active sites at the interface of the metalloprotein complex and the density of states reflects the metallic nature of the active sites. The reduced value of the canonical orbital gap indicates the state of dynamic nature after Ag ion assimilation on active sites and smooth electron transfer. These incorporated active protein sites are more efficient in electrolytic splitting of water than pristine sites due to their low value of Gibbs free energy for the HER in terms of hydrogen coverages. Volcano plot analysis and the free energy diagram are compared for understanding the hydrogen evolution efficiency. Moreover, the essential role of the interfacial electronic properties in regulating the HER catalytic activity of water splitting sites and enhancing the efficiency is elucidated. PMID:27499158

  17. PET Bottles Recycling

    Veselý, Václav; Hanika, Jiří

    Praha : Ministry of Industry and Trade CR, 2008, s. 1-6. ISBN N. [Pollutec 2008. Lyon (FR), 02.12.2008-05.12.2008] R&D Projects: GA MPO FI-IM4/096 Institutional research plan: CEZ:AV0Z40720504 Keywords : pet recycling * waste * technical appliances Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  18. Total PET Recycling

    Veselý, Václav; Punčochář, Miroslav

    Bratislava : Slovak University of Technology, 2004 - (Markoš, J.; Štefuca, V.), s. 222 ISBN 80-227-2052-6. [International Conference of Slovak Society of Chemical Engineering /31./. Tatranské Matliare (SK), 24.05.2004-28.05.2004] Institutional research plan: CEZ:AV0Z4072921 Keywords : recycling * waste management * pet Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  19. Vehicle recycling regulations

    Smink, Carla

    2007-01-01

    The number of end-of-life vehicles (ELVs) in the EU is increasing continously. Around 75 percent of an ELV are recyclable metals. The forecast growth in the number of ELVs calls for regulation that aims to minimise the environmental impact of a car. Using Denmark as an example, this article...

  20. Systematic photovoltaic waste recycling

    Palitzsch, Wolfram; Loser, Ulrich [Loser Chemie GmbH, Langenweissbach (Germany)

    2013-04-01

    Indium, selenium, tellurium, gallium, molybdenum, cadmium and silicon are some of the major elements used in photovoltaic cells. Fully aware of the limited availability of these metals in future, recycling has been recognized as the most advisable end-of-life strategy to save these raw materials from turning into production wastes. On the other hand, statutory measures such as 'Kreislaufwirtschaftsgesetz' (the German law encouraging closed-loop economy) aim to achieve a maximum quota of recycling and a minimum use of resources such as energy and raw materials. By the year of 2050, end-of-life photovoltaic panels are anticipated to amount to 9.57 million tons. Although we are not there yet, discussions on recycling have already started. We have to prepare for higher waste volumes expected in the coming years. But already today we need to solve some environmental problems like loss of conventional resources (e.g., glass) and rare metals. All of the known approaches for recycling photovoltaic semiconductor material seem economically and environmentally inefficient. In this paper, we report about reclaiming metals from scrap of thin film systems and associated photovoltaic manufacturing wastes like sandblasting dust and overspray. We also report one universal wet-chemical treatment for reclaiming the metals from CIS, CIGS or CdTe photovoltaic waste. Further, we discuss the application of our method to new PV systems, such as substrates other than glass (stainless steel, aluminum or plastic foil sheets) and alternative semiconductor alloys such as GaAs. (orig.)

  1. RECYCLABILITY INDEX FOR AUTOMOBILES

    The project's purpose is to create a rating system for the ecological impacts of vehicles at the end of their life based on recyclability, toxic material content, and ultimate disposal. Each year, 10-11 million vehicles are retired from service in the United States. The vehi...

  2. Sustainable Concrete with Recycled Aggregate

    Kara, P

    2012-01-01

    Concretes produced with recycled aggregates are the subject of several papers recently published in the technical literature. Substitution of natural aggregates can be one of possibilities to take care of landfills and increase of CO2 emissions into the atmosphere in Latvia. Recycled aggregate is a valuable resource; value-added consumption of recycled aggregate, as replacement for virgin aggregate in concrete, can yield significant energy and environmental benefits. In present study recycled...

  3. Recycling - Danish Waste Management Strategy

    Romann, Anne Funch; Thøgersen, John; Husmer, Lis;

    The report challanges recycling as the only waste handling strategy. The tonnes of recycled materials should not be the only goal - it is essential to minimize the waste production and focus on eliminating hazardous materials.......The report challanges recycling as the only waste handling strategy. The tonnes of recycled materials should not be the only goal - it is essential to minimize the waste production and focus on eliminating hazardous materials....

  4. Antiproton Stacking in the Recycler

    Burov, A

    2003-01-01

    Possibilities to accumulate antiprotons in the Recycler are considered for three different cases: with current stochastic cooling, with upgraded stochastic cooling and with electron cooling. With stochastic cooling only, even upgraded, Recycler looks hardly useful. However, with electron cooling at its goal parameters and reasonably good vacuum in the Recycler, this machine would be efficient.

  5. Recycling of the #5 polymer.

    Xanthos, Marino

    2012-08-10

    Polypropylene (PP) is a widely used plastic with consumer applications ranging from food packaging to automotive parts, including car battery casings. To differentiate it from other recyclable plastics, it is designated as #5. Here, the factors contributing to PP recycling rates are briefly reviewed. Considerations include collection and separation efficiency, processing chemistry, and market dynamics for the products derived from recyclates. PMID:22879510

  6. Hydrogen movement and the next action: fossil fuels industry and sustainability economics

    Since the hydrogen movement started in 1974, there has been progress in research, development, demonstration and commercialization activities, covering all aspects of the hydrogen energy system. In order to solve the interrelated problems of depletion of fossil fuels and the environmental impact of the combustion products of fossil fuels, it is desirable to speed up the conversion to the hydrogen energy system. Most established industries have joined the hydrogen movement. There is one exception: the fossil fuel industry. A call is made to the fossil fuel industry to join the hydrogen movement. It is also proposed to change the present economic system with a sustainability economics in order to account for environmental damage, recyclability and decommissioning, and thus, ensure a sustainable future. (Author)

  7. Hydrogen as an Indicator to Assess Biological Activity During Trace-Metal Bioremediation

    Jaffe, P. R.; Komlos, J.; Brown, D. G.; Lovley, D. R.

    2002-05-01

    The design and operation of a trace-metal or radionuclide bioremediation scheme requires that specific redox conditions be achieved at given zones of an aquifer for a predetermined duration. Tools are therefore needed to identify and quantify the terminal electron acceptor processes (TEAPs) that are being achieved during bioremediation in an aquifer, and that this is done at a high spatial resolution. Hydrogen holds the promise of being a key parameter that may be used to identify TEAPs. Theoretical analysis have shown that steady-state hydrogen levels in the subsurface are solely dependent upon the physiological parameters of the hydrogen-consuming microorganisms, and that hydrogen concentrations increase as each successive TEAP yields less energy for bacterial growth. The assumptions for this statement may not hold during a bioremediation scheme in which an organic substrate is injected into the subsurface and where organisms may consume hydrogen and carbon simultaneously. The objective of the research is to gain a basic understanding of the hydrogen dynamics in an aquifer during a trace metal/radionuclide bioremediation scheme. For this purpose, a series of batch studies have been conducted during the first year of this project. In these studies the utilization of acetate and hydrogen by geobacter sulfurreducens were studied. In all cases Fe(III) was the electron acceptor. Microcosms were set up to investigate the utilization of hydrogen and acetate when either of them is the sole electron donor and when both are present and utilized simultaneously as electron donor. These experiments were conducted for varying initial conditions of the hydrogen and acetate concentration, and the disappearance of these compounds plus the evolution of Fe(II) as well as biomass was monitored over time. The results of these studies indicate that the biokinetic coefficients describing the rate of hydrogen utilization are not affected by the simultaneous utilization of acetate. While

  8. MOX fuel recycling. Present status and prospects

    /year) masters all the activities of treatment since the start up, in the seventies. La Hague and MELOX are now considered as technological reference for all the international projects of recycling (in the US with the MFFF plant, in Japan with JMOX plant and other countries). The return of experience of MOX in Europe (burn up and reliability) will also be presented. MELOX in addition to the European needs, is being fabricating the first MOX for Japan, contributing to the Pu thermal program expressing the recycling policy in Japan as a priority. For the mid term, the GEN3 AREVA reactors (EPRTM, ATMEATM) are designed taking into account all the needs for recycling. Together with the UO2, ERU, and MOX fuels, and GEN3 reactors able to recycle at the level wished by the utility, AREVA offers the utilities all the possibilities for recycling the energy without any worry about the fuel, either fresh or used. EPR is a trademark of AREVA Group. ATMEA is a trademark of AREVA (joint venture between AREVA and MHI). (authors)

  9. STUDIES ON THE STATE OF PALLADIUM AND HYDROGENATION ACTIVITY OF RESIN SUPPORTED PALLADIUM—TIN OXIDE CATALYSTS

    HuWeibing; ZhangShengming; 等

    1994-01-01

    Sereral Pd-SnO2/D3520 and Pd-PbO/D3520 catalysts with Pd/D3520,SnO2/D3520 and PbO/D3520 catalysts as reference were studied by means of IR and XPS.Interaction between Pd and the second metal or between metal and support was observed.Results show that there is a strong interaction between Pd and the second metal,but there is not an obvious interaction between metal and support.The active constituent is Pd.Hydrogenation activity of the catalysts is altered because of the interaction between Pd and the second metal.The activity of the catalysis for hydrogenation has relation to outer layer valence electron density of Pd.

  10. INEL metal recycle annual report, FY-94

    In 1992, the mission of the Idaho Chemical Processing Plant was changed from reprocessing of spent nuclear fuels to development of technologies for conditioning of spent nuclear fuels and other high-level wastes for disposal in a geologic repository. In addition, the Department of Energy (DOE) directed Idaho National Engineering Laboratory (INEL) to develop a program plan addressing the management of radioactive contaminated scrap metal (RSM) within the DOE complex. Based on discussions with the EM-30 organization, the INEL Metal Recycle program plan was developed to address all issues of RSM management. Major options considered for RSM management were engineered interim storage, land disposal as low-level waste, and beneficial reuse/recycle. From its inception, the Metal Recycle program has emphasized avoidance of storage and disposal costs through beneficial reuse of RSM. The Metal Recycle program plan includes three major activities: Site-by-site inventory of RSM resources; validation of technologies for conversion of RSM to usable products; and identification of parties prepared to participate in development of a RSM recycle business

  11. Economic analysis of recycling contaminated concrete

    Stephen, A.; Ayers, K.W.; Boren, J.K.; Parker, F.L. [Vanderbilt Univ., Nashville, TN (United States)

    1997-02-01

    Decontamination and Decommissioning activities in the DOE complex generate large volumes of radioactively contaminated and uncontaminated concrete. Currently, this concrete is usually decontaminated, the contaminated waste is disposed of in a LLW facility and the decontaminated concrete is placed in C&D landfills. A number of alternatives to this practice are available including recycling of the concrete. Cost estimates for six alternatives were developed using a spreadsheet model. The results of this analysis show that recycling alternatives are at least as economical as current practice.

  12. A Comparative Evaluation of Dried Activated Sludge and Mixed Dried Activated Sudge with Rice Husk silica to Remove Hydrogen Sulfide

    Seyed Mahmoud Mehdinia

    2013-03-01

    Full Text Available The aim of this study was to investigate the effectiveness of dried activated sludge (DAS and mixed dried activated sludge with rice husk silica (DAS & RHS for removal of hydrogen sulfide (H2S. Two laboratory-scale filter columns (packed one litter were operated. Both systems were operated under different conditions of two parameters, namely different inlet gas concentrations and different inlet flow rates. The DAS & RHS packed filter showed more than 99.96% removal efficiency (RE with empty bed residence time (EBRT of 45 to 90 s and 300 mg/L inlet concentration of H2S. However, the RE decreased to 96.87% with the EBRT of 30 s. In the same condition, the DAS packed filter showed 99.37% RE. Nonetheless, the RE was shown to have dropped to 82.09% with the EBRT of 30 s. The maximum elimination capacity (EC was obtained in the DAS & RHS packed filter up to 52.32 g/m3h, with the RE of 96.87% and H2S mass loading rate of 54 g/m3h. The maximum EC in the DAS packed filter was obtained up to 44.33 g/m3h with the RE of 82.09% and the H2S mass loading rate of 54 g/m3h. After 53 days of operating time and 54 g/m3h of loading rates, the maximum pressure drop reached to 3.0 and 8.0 (mm H2O for the DAS & RHS packed and DAS packed filters, respectively. Based on the findings of this study, the DAS & RHS could be considered as a more suitable packing material to remove H2S.

  13. Impedance approach to activity of hydrogen evolution reaction on spatially heterogeneous GC electrode surfaces: metal free vs. Ru catalysed case

    Activities of hydrogen evolution reaction, HER, on two differently modified metal-free GC electrodes and on the same electrodes supplied with ruthenium catalyst, have been studied in H2SO4 electrolyte solution. GC electrodes were gradually modified by electrochemical oxidation/reduction procedure, changing morphology properties and forming spatially heterogeneous surfaces. Ruthenium was deposited on the top of two differently modified GC electrodes in nearly the same specific mass of ∼25 μg cm−2 of active ruthenium, showing almost uniform dispersion of ruthenium particle clusters on less modified electrode and pronounced agglomeration on more modified electrode surface. Results of cyclic voltammetry and polarization experiments, aiding mostly in adjustments of the specific masses of active ruthenium on two GC electrodes and characteristic potential regions of “double-layer” vs. HER responses, were found strongly correlated with electrochemical impedance data. Evaluations of impedance data were done using standard regression procedure based on strictly postulated statistical criteria, in conditions of complex interfacial impedance/frequency functions accounting for: a) spatial surface heterogeneity, b) diffusion controlled hydrogen absorption and c) hydrogen evolution involving hydrogen adsorption. Activities for HER on bare GC electrodes were found much lower than on the corresponding Ru/GC electrodes, but increased with stage of surface modification. At Ru/GC electrodes, HER is proceeding exclusively on ruthenium particles with activity related to the mass of active ruthenium and total ruthenium utilization of ∼25%. Not any effect of the supporting GC electrode morphology has been observed for HER on Ru/GC electrodes

  14. The Nature of Activated Non-classical Hydrogen Bonds: A Case Study on Acetylcholinesterase-Ligand Complexes.

    Berg, Lotta; Mishra, Brijesh Kumar; Andersson, C David; Ekström, Fredrik; Linusson, Anna

    2016-02-01

    Molecular recognition events in biological systems are driven by non-covalent interactions between interacting species. Here, we have studied hydrogen bonds of the CH⋅⋅⋅Y type involving electron-deficient CH donors using dispersion-corrected density functional theory (DFT) calculations applied to acetylcholinesterase-ligand complexes. The strengths of CH⋅⋅⋅Y interactions activated by a proximal cation were considerably strong; comparable to or greater than those of classical hydrogen bonds. Significant differences in the energetic components compared to classical hydrogen bonds and non-activated CH⋅⋅⋅Y interactions were observed. Comparison between DFT and molecular mechanics calculations showed that common force fields could not reproduce the interaction energy values of the studied hydrogen bonds. The presented results highlight the importance of considering CH⋅⋅⋅Y interactions when analysing protein-ligand complexes, call for a review of current force fields, and opens up possibilities for the development of improved design tools for drug discovery. PMID:26751405

  15. Rethinking Recycling: An Oregon Waste Reduction Curriculum.

    Oregon State Dept. of Environmental Quality, Portland.

    This updated curriculum guide is designed to provide teachers of elementary school science with a set of activities on recycling and waste reduction. The curriculum has three sections: (1) Grades K-3 Lessons; (2) Grades 4-5 Lessons; and (3) Teacher's Resource Guide. It is designed to take students from an introduction to natural resources and…

  16. CEA/Valduc Plutonium Recycling Facility Project

    Pu recycling activities are operated in the 118 facility on Valduc CEA/DAM center. This facility, built in 1963, does not meet modern safety requirements especially for fire and earthquake hazards. The last safety review commission in 2000 gave the authorization to continue recycling operations in the 118 facility until the end of 2010 with the obligation of the achievement, of a safety upgrade program in 2005. At the same time, CEA/DAM has decided to launch the project for the building of a new facility for Pu recycling and legacy residues stabilization. In addition to specific requirements for Pu metal preparation, the processes retained for this facility have to optimize safety, wastes, costs and dosimetry. Moreover, all wastes have to be suitable for discard or of for a safe long term storage in nuclear vault. First conceptual design elements and important basic safety requirements will be presented in this communication. (authors)

  17. Electrochemical Hydrogen Peroxide Generator

    Tennakoon, Charles L. K.; Singh, Waheguru; Anderson, Kelvin C.

    2010-01-01

    needed are water and oxygen or air. 2. The product is pure and can therefore be used in disinfection applications directly or after proper dilution with water. 3. Oxygen generated in the anode compartment is used in the electrochemical reduction process; in addition, external oxygen is used to establish a high flow rate in the cathode compartment to remove the desired product efficiently. Exiting oxygen can be recycled after separation of liquid hydrogen peroxide product, if so desired. 4. The process can be designed for peroxide generation under microgravity conditions. 5. High concentrations of the order of 6-7 wt% can be generated by this method. This method at the time of this reporting is superior to what other researchers have reported. 6. The cell design allows for stacking of cells to increase the hydrogen peroxide production. 7. The catalyst mix containing a diquaternary ammonium compound enabled not only higher concentration of hydrogen peroxide but also higher current efficiency, improved energy efficiency, and catalyst stability. 8. The activity of the catalyst is maintained even after repeated periods of system shutdown. 9. The catalyst system can be extended for fuel-cell cathodes with suitable modifications.

  18. The Fernald Waste Recycling Program

    Motl, G.P.

    1993-10-26

    Recycling is considered a critical component of the waste disposition strategy at the Fernald Plant. It is estimated that 33 million cubic feet of waste will be generated during the Fernald cleanup. Recycling some portion of this waste will not only conserve natural resources and disposal volume but will, even more significantly, support the preservation of existing disposition options such as off-site disposal or on-site storage. Recognizing the strategic implications of recycling, this paper outlines the criteria used at Fernald to make recycle decisions and highlights several of Fernald`s current recycling initiatives.

  19. Recycling of Byproduct Hydrogen from the Chlor-Alkali Plant Being Utilized in the Ammonia Unit%氯碱装置副产氢气在冀衡化肥公司的回收利用

    孙凤徐

    2014-01-01

    介绍冀衡公司将150 kt/a 离子膜法烧碱装置排空的氢气引入合成氨装置回收利用的情况,着重阐述氢气的输送方案、系统采取的安全措施、装置运行情况及效益等。%Describe the hydrogen emptied from the 150 kt/a ionic membrane caustic soda plant being utilized in the ammonia unit ,focus on the hydrogen delivery plan ,the system security measures , the unit operation and the benefits ,etc .

  20. NOx-Catalyzed Gas-Phase Activation of Methane:the Formation of Hydrogen

    Chaoxian Xiao; Zhen Yan; Yuan Kou

    2003-01-01

    NOx-catalyzed oxidation of methane without a solid catalyst was investigated, and a hydrogen selectivity of 27% was obtained with an overall methane conversion of 34% and a free O2 concentration of 1.7% at 700 ℃.

  1. New biotechnological perspectives of a NADH oxidase variant from Thermus thermophilus HB27 as NAD+-recycling enzyme

    Rocha-Martín Javier

    2011-11-01

    Full Text Available Abstract Background The number of biotransformations that use nicotinamide recycling systems is exponentially growing. For this reason one of the current challenges in biocatalysis is to develop and optimize more simple and efficient cofactor recycling systems. One promising approach to regenerate NAD+ pools is the use of NADH-oxidases that reduce oxygen to hydrogen peroxide while oxidizing NADH to NAD+. This class of enzymes may be applied to asymmetric reduction of prochiral substrates in order to obtain enantiopure compounds. Results The NADH-oxidase (NOX presented here is a flavoenzyme which needs exogenous FAD or FMN to reach its maximum velocity. Interestingly, this enzyme is 6-fold hyperactivated by incubation at high temperatures (80°C under limiting concentrations of flavin cofactor, a change that remains stable even at low temperatures (37°C. The hyperactivated form presented a high specific activity (37.5 U/mg at low temperatures despite isolation from a thermophile source. Immobilization of NOX onto agarose activated with glyoxyl groups yielded the most stable enzyme preparation (6-fold more stable than the hyperactivated soluble enzyme. The immobilized derivative was able to be reactivated under physiological conditions after inactivation by high solvent concentrations. The inactivation/reactivation cycle could be repeated at least three times, recovering full NOX activity in all cases after the reactivation step. This immobilized catalyst is presented as a recycling partner for a thermophile alcohol dehydrogenase in order to perform the kinetic resolution secondary alcohols. Conclusion We have designed, developed and characterized a heterogeneous and robust biocatalyst which has been used as recycling partner in the kinetic resolution of rac-1-phenylethanol. The high stability along with its capability to be reactivated makes this biocatalyst highly re-useable for cofactor recycling in redox biotransformations.

  2. Saved from the Trash Can. Keep That Recycled Paper in Circulation.

    Wheatley, Jack

    1983-01-01

    Lessons on conservation/recycling taught in upper elementary/middle schools often feature a paper recycling activity in which students make new paper from old. Methods to accomplish this are outlined. In addition, the use of the recycled paper for art projects is discussed. (Author/JN)

  3. The effects of hydrogen bonds on metal-mediated O2 activation and related processes

    Shook, Ryan L.; Borovik, A. S.

    2008-01-01

    Hydrogen bonds stabilize and direct chemistry performed by metalloenzymes. With inspiration from enzymes, we will utilize an approach that incorporates intramolecular hydrogen bond donors to determine their effects on the stability and reactivity of metal complexes. Our premise is that control of secondary coordination sphere interactions will promote new function in synthetic metal complexes. Multidentate ligands have been developed that create rigid organic structures around metal ions. The...

  4. SYNTHESIS OF 8-HYDROXYQUINOLINE CHALCONES: TRANS CONFIGURATION, INTRAMOLECULAR HYDROGEN BONDS, BROMINATION, AND ANTIFUNGAL ACTIVITY

    ALONSO J MARRUGO-GONZÁLEZ; VALERIE D ORLOV; ROBERTO FERNANDEZ-MAESTRE

    2012-01-01

    Nine (8-Hydroxyquinolin-5-yl)-arylpropenones were synthesized and their structures demonstrated by IR and NMRspectroscopy. These molecules showed transconfiguration and strong intramolecular hydrogen bonding; in the IR spectra of 5-formyl-8-hydroxyquinoline, 5-acetyl-8-hydroxyquinoline, 1-(8-hydroxyquinolin-5-yl)-3-phenylprop-2-en-1-one and 3-(8-hydroxyquinolin-5-yl)-1-phenylprop-2-en-1-one in CHCl3, besides the known intermolecular hydrogen band (~3180 cm-1), we identified the intramolecular...

  5. Recycling of typical supercapacitor materials.

    Vermisoglou, Eleni C; Giannouri, Maria; Todorova, Nadia; Giannakopoulou, Tatiana; Lekakou, Constantina; Trapalis, Christos

    2016-04-01

    A simple, facile and low-cost method for recycling of supercapacitor materials is proposed. This process aims to recover some fundamental components of a used supercapacitor, namely the electrolyte salt tetraethyl ammonium tetrafluoroborate (TEABF4) dissolved in an aprotic organic solvent such as acetonitrile (ACN), the carbonaceous material (activated charcoal, carbon nanotubes) purified, the current collector (aluminium foil) and the separator (paper) for further utilization. The method includes mechanical shredding of the supercapacitor in order to reduce its size, and separation of aluminium foil and paper from the carbonaceous resources containing TEABF4by sieving. The extraction of TEABF4from the carbonaceous material was based on its solubility in water and subsequent separation through filtering and distillation. A cyclic voltammetry curve of the recycled carbonaceous material revealed supercapacitor behaviour allowing a potential reutilization. Furthermore, as BF4 (-)stemming from TEABF4can be slowly hydrolysed in an aqueous environment, thus releasing F(-)anions, which are hazardous, we went on to their gradual trapping with calcium acetate and conversion to non-hazardous CaF2. PMID:26862148

  6. Integrated Recycling Test Fuel Fabrication

    The Integrated Recycling Test is a collaborative irradiation test that will electrochemically recycle used light water reactor fuel into metallic fuel feedstock. The feedstock will be fabricated into a metallic fast reactor type fuel that will be irradiation tested in a drop in capsule test in the Advanced Test Reactor on the Idaho National Laboratory site. This paper will summarize the fuel fabrication activities and design efforts. Casting development will include developing a casting process and system. The closure welding system will be based on the gas tungsten arc burst welding process. The settler/bonder system has been designed to be a simple system which provides heating and controllable impact energy to ensure wetting between the fuel and cladding. The final major pieces of equipment to be designed are the weld and sodium bond inspection system. Both x-radiography and ultrasonic inspection techniques have been examine experimentally and found to be feasible, however the final remote system has not been designed. Conceptual designs for radiography and an ultrasonic system have been made. (author)

  7. Integrated Recycling Test Fuel Fabrication

    R.S. Fielding; K.H. Kim; B. Grover; J. Smith; J. King; K. Wendt; D. Chapman; L. Zirker

    2013-03-01

    The Integrated Recycling Test is a collaborative irradiation test that will electrochemically recycle used light water reactor fuel into metallic fuel feedstock. The feedstock will be fabricated into a metallic fast reactor type fuel that will be irradiation tested in a drop in capsule test in the Advanced Test Reactor on the Idaho National Laboratory site. This paper will summarize the fuel fabrication activities and design efforts. Casting development will include developing a casting process and system. The closure welding system will be based on the gas tungsten arc burst welding process. The settler/bonder system has been designed to be a simple system which provides heating and controllable impact energy to ensure wetting between the fuel and cladding. The final major pieces of equipment to be designed are the weld and sodium bond inspection system. Both x-radiography and ultrasonic inspection techniques have been examine experimentally and found to be feasible, however the final remote system has not been designed. Conceptual designs for radiography and an ultrasonic system have been made.

  8. An Empirical Analysis of the Recycling System of Waste Products in the Japanese Economy (in Japanese)

    Masahiko Shimizu; Mikio Suga; Takashi Saito; Masahide Hayashida; Toshiyuki Tanabe; Kazuyoshi Nakata

    2004-01-01

    1. Purpose The purpose of this study is to design the system of recycling based society which "the Basic Law for Establishing the Recycling- based Society" aims, and construct an econometric model of Japanese economy in which resource recycling processes or activities are explicitly introduced. Furthermore, we will propose some simulations of promoting recycling of iron scrap, glass bottle, aluminum ingot, waste paper and PET resin. 2. Background There are quality gaps between products made f...

  9. Recycling as moral behaviour

    Thøgersen, John

    It is argued in this paper that in the affluent, industrial societies, environmental behaviours like recycling are typically classified within ""the domain of morality"" in people's minds. Intentions regarding these types of behaviours are not ba a thorough - conscious or unconscious - calculation...... of the balance of costs and benefits. Rather, they are a function of the person's moral beliefs, i.e., beliefs in what is the right or wrong thing to do. The paper gives a brief review of the literature with the intention of uncovering problems and shortcomings in the framework of the SEU-model and...... the Theory of Reasoned Action (TRA) with regard to understanding recycling behaviour. Further, examples of misleading policy conclusions are discussed suggested that within the framework of cognitive psychology, Schwartz's model of altruistic behaviour offers a more satisfying starting point for...

  10. Repression of hydrogen uptake using conjugated oligoelectrolytes in microbial electrolysis cells

    Hou, Huijie

    2014-11-01

    Copyright © 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. DSBN+, a conjugated oligoelectrolyte (COE), was added to microbial electrolysis cells (MECs) to improve hydrogen recovery. The volume of hydrogen gas recovered in a fedbatch cycle of mixed culture MECs increased by 126× compared to controls (no COE addition), mainly by preventing the loss of hydrogen to methane production. Performance in pure culture MECs fed with Geobacter sulfurreducens increased by factors of 10.5 in terms of energy yield, 2.1 in COD removal, and 11.8 in hydrogen yield. Hydrogen gas recycling was reduced, and the volume of hydrogen gas recovered increased by 6.5× compared to controls. Minimal methane production and a lack of hydrogen gas uptake by G. sulfurreducens suggested that the COEs increased hydrogen recoveries by interfering with hydrogen uptake by hydrogenotrophic methanogens but also by exoelectrogenic bacteria. COEs may therefore be useful for inhibiting the activities of certain hydrogenases, although the mechanism of inhibition needs further investigation.

  11. Hydrogenation of Olefins Catalyzed by Highly Active Titanocene/NaH or n-BuLi Catalyst Systems

    2002-01-01

    The effects of the substituents on the cyclopentadienyl ring and the reducing agents on the catalytic activity and the stability of titanocene/NaH or n-BuLi systems for the hydrogenation of olefins were investigated. For the catalyst systems composed of titanocene/NaH or n-BuLi, the nature and the number of the substituents on the cyclopentadienyl ring control the catalytic behavior of those two systems. The effect of the reducing agent on the catalytic activity is relatively small. In addition, the characters of the hydrogenation of various olefins catalyzed respectively by Cp2TiCl2/NaH or n-BuLi systems were compared.

  12. Machine coolant recycling system

    Machining processes at the 272W Site Fabrication Services (SFS) produce a waste stream consisting of dirty machine coolant. During use the coolant becomes contaminated with metal chips from milling, and oil, dirt and solvents from the machining process. The mixture is designated as a Washington State dangerous waste with WP02 (persistence), D007 (chromium) and D008 (lead) waste codes. This process results in the generation of 13.5 m3 of hazardous waste per year with an annual cost for coolant replacement, waste management and waste disposal of approximately $137,000. To identify alternatives to this situation, ICF Kaiser Hanford Company (ICF KH) North Environmental Services conducted a pollution prevention opportunity assessment (P20A) on the machining processes. A coolant recycler and sump sucker unit were selected as the most cost-effective waste reduction options. In December 1994, ICF KH received return on investment (ROI) funding from the U.S. Department of Energy Richland Operations Office (DOE-RL) to implement this option. The coolant recycling and the sump sucker units were purchased and installed in July 1995 at a total cost of $61,000. The sump sucker removes the dirty coolant from the fabrication machinery and filters it to remove shavings and sludge. The filtered coolant then is transferred to the coolant recycling system for further processing. The coolant recycling system reconditions the filtered coolant for use in the machining equipment, and mixes the concentrated coolant to the correct concentration. As a result of implementing this option, the annual generation of waste coolant was reduced by 12 m3. The annual cost savings exceed $119,000 with an ROI of 186%. Additional benefits include reduced coolant usage; improved tool life, wheel life, finish, size control, corrosion protection, and operator working conditions; increase machine open-quotes up-timeclose quotes; and reduced machine tool maintenance

  13. Plutonium recycling in PWR

    Two concepts of 100% MOX PWR cores are presented. They are designed such as to minimize the consequences of the introduction of Pu on the core control. The first one has a high moderation ratio and the second one utilizes an enriched uranium support. The important design parameters as well as their capabilities to multi recycle Pu are discussed. We conclude with the potential interest of the two concepts. (author)

  14. Usage of Recycled Pet

    A. Ebru Tayyar; Sevcan Üstün

    2010-01-01

    The increasing industrialization, urbanization and the technological development have caused to increase depletion of the natural resources and environmental pollution's problem. Especially, for the countries which have not enough space recycling of the waste eliminating waste on regular basis or decreasing the amount and volume of waste have provided the important advantages. There are lots of studies and projects to develop both protect resources and prevent environmental pollution. PET bot...

  15. Synergistic hydrogen desorption behavior of magnesium aluminum hydride synthesized by mechano-chemical activation method

    Highlights: ► Mg(AlH4)2 could release 3.1 wt% H2 at initial temperature as low as 100 °C. ► The synergistic and mutual catalytic effects of NaAlH4 and Mg(AlH4)2 were noticed. ► In situ synchrotron XRD confirmed the two-step dehydrogenation process of Mg(AlH4)2. - Abstract: A mechano-chemical activation synthesis (MCAS) is employed to fabricate Mg(AlH4)2 via milling the precursors, specifically NaAlH4 and MgCl2. The corresponding dehydrogenation behavior of the synthesized powders is investigated. The experimental results showed that incomplete synthesis or premature dehydrogenation may occur if the milling process was not properly controlled. The hydrogen content of each synthesized powder is determined by using a thermal gravimetric analyzer (TGA). The dehydrogenation reactions of the synthesized powders are investigated by employing ex situ X-ray diffraction (XRD), in situ synchrotron XRD and differential thermal analysis (DTA). The results showed that the incompletely synthesized powder consisted of residual NaAlH4 in the synthesized Mg(AlH4)2, which demonstrated an initial dehydrogenation temperature as low as 100 °C and accompanied with a maximum amount (3.1 wt%) of H2 released below 350 °C. The mutual catalytic effect of both NaAlH4 and Mg(AlH4)2 on lowering their initial dehydrogenation temperature is confirmed.

  16. Influence of chemical activation of a 35% hydrogen peroxide bleaching gel on its penetration and efficacy--in vitro study

    Torres, C R G; Wiegand, A.; Sener, B.; Attin, T.

    2010-01-01

    OBJECTIVES: The aim of this study was to evaluate the effects of chemical activation of hydrogen peroxide (HP) gel on colour changes and penetration through the tooth structure. METHODS: One hundred and four bovine incisors were used. One dentine (CD) disc and one enamel-dentine (ED) disc were prepared from each tooth. They were positioned over artificial pulpal chambers and the bleaching was performed with an experimental 35% HP gel. Two control and six experimental groups were prepared. In ...

  17. Preparation of Dendritic Carbosilane-supported Palladium Catalyst and Its Catalytic Activity in Hydrogenation of Organic Compounds

    2005-01-01

    The preparation of palladium complex from PdCl2·2H2O and earbosilane dendrimers with peripheral aminopropyl groups was described. The compound obtained was characterized by IR, 1H NMR, X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma atomic emission spectrometric (ICP-AES) spectroscopy respectively. The metal complex was employed as catalyst in hydrogenation of organic compounds. The high activity of the complex was probably due to the formation of the eoordinatively unsaturated palladium.

  18. Gas- and plasma-driven hydrogen permeation through a reduced activation ferritic steel alloy F82H

    Zhou, Haishan, E-mail: zhou.haishan@LHD.nifs.ac.jp [The Graduate University for Advanced Studies, Toki 509-5292, Gifu (Japan); Hirooka, Yoshi; Ashikawa, Naoko; Muroga, Takeo; Sagara, Akio [The Graduate University for Advanced Studies, Toki 509-5292, Gifu (Japan); National Institute for Fusion Science, 322-6 Oroshi, Toki 509-5292, Gifu (Japan)

    2014-12-15

    The first wall of a magnetic fusion power reactor will be subjected to hydrogen isotope permeation by the two mechanisms: one is gas-driven and the other is plasma-driven. Hydrogen transport through a reduced activation ferritic steel alloy F82H has been investigated using a steady-state laboratory-scale plasma device. Permeation parameters including permeability, solubility and diffusivity have been measured in the temperature range from 150 to 520 °C. The surface recombination coefficient for hydrogen has also been estimated by a one-dimensional steady-state permeation model with the input data taken from experiments. Using these parameters, the hydrogen plasma-driven permeation flux and inventory for a 0.5 cm thick first wall around 500 °C are estimated to be ∼1.0 × 10{sup 13} atom cm{sup −2} s{sup −1} and ∼2 × 10{sup 16} atom cm{sup −3}, respectively. Also, the implications of all these data on reactor operation are discussed.

  19. Hydrogen Storage in Pristine and d10-Block Metal-Anchored Activated Carbon Made from Local Wastes

    Mohamed F. Aly Aboud

    2015-04-01

    Full Text Available Activated carbon has been synthesized from local palm shell, cardboard and plastics municipal waste in the Kingdom of Saudi Arabia. It exhibits a surface area of 930 m2/g and total pore volume of 0.42 cm3/g. This pristine activated carbon has been further anchored with nickel, palladium and platinum metal particles by ultrasound-assisted impregnation. Deposition of nanosized Pt particles as small as 3 nm has been achieved, while for Ni and Pd their size reaches 100 nm. The solid-gas hydrogenation properties of the pristine and metal-anchored activated carbon have been determined. The pristine material exhibits a reversible hydrogen storage capacity of 2.3 wt% at 77 K and 3 MPa which is higher than for the doped ones. In these materials, the spillover effect due to metal doping is of minor importance in enhancing the hydrogen uptake compared with the counter-effect of the additional mass of the metal particles and pore blocking on the carbon surface.

  20. Antioxidant activities of nano-bubble hydrogen-dissolved water assessed by ESR and 2,2′-bipyridyl methods

    Kato, Shinya [Laboratory of Cell-Death Control BioTechnology, Faculty of Life and Environmental Sciences, Prefectural University of Hiroshima, Nanatsuka 562, Shobara, Hiroshima 727-0023 (Japan); Radio Isotope Facilities for Medical Science, Life Science Research Center, Mie University, Edobashi 2-174, Tsu, Mie 514-8507 (Japan); Matsuoka, Daigo [− 600 mV Co., Ltd. Matsuhama-cho 2-4-1, Fukuyama, Hiroshima 720-0802 (Japan); Miwa, Nobuhiko, E-mail: miwa@butsuryo.ac.jp [Laboratory of Cell-Death Control BioTechnology, Faculty of Life and Environmental Sciences, Prefectural University of Hiroshima, Nanatsuka 562, Shobara, Hiroshima 727-0023 (Japan); Department of Radiological Technology, Faculty of Health Sciences, Butsuryo College of Osaka, Otorikitamachi 3-33, Nishi-ku, Sakai, Osaka 593-8328 (Japan)

    2015-08-01

    We prepared nano-bubble hydrogen-dissolved water (nano-H water) which contained hydrogen nano-bubbles of < 717-nm diameter for 54% of total bubbles. In the DMPO-spin trap electron spin resonance (ESR) method, the DMPO-OH:MnO ratio, being attributed to amounts of hydroxyl radicals (·OH), was 2.78 for pure water (dissolved hydrogen [DH] ≤ 0.01 ppm, oxidation-reduction potential [ORP] = + 324 mV), 2.73 for tap water (0.01 ppm, + 286 mV), 2.93 for commercially available hydrogen water (0.075 ppm, + 49 mV), and 2.66 for manufactured hydrogen water (0.788 ppm, − 614 mV), whereas the nano-H water (0.678 ppm, − 644 mV) exhibited 2.05, showing the superiority of nano-H water to other types of hydrogen water in terms of ·OH-scavenging activity. Then, the reduction activity of nano-H water was assessed spectrophotometrically by the 2,2′-bipyridyl method. Differential absorbance at 530 nm was in the order: 0.018 for pure water, 0.055 for tap water, 0.079 for nano-H water, 0.085 for commercially available hydrogen water, and 0.090 for manufactured hydrogen water, indicating a prominent reduction activity of hydrogen water and nano-H water against oxidation in ascorbate-coupled ferric ion–bipyridyl reaction. Thus, nano-H water has an improved antioxidant activity as compared to hydrogen water of similar DH-level, indicating the more marked importance of nano-bubbles rather than the concentration of hydrogen in terms of ·OH-scavenging. - Highlights: • We assessed the antioxidant activity of nano-bubble hydrogen-dissolved water (nano-H water). • Nano-H water exhibited superior ·OH-scavenging activity in DMPO-spin trap ESR. • A reduction ability of nano-H water was shown in 2,2′-bipyridyl reaction. • Nano-H water has an improved antioxidant activity as compared to hydrogen water of similar DH-level. • Results indicated the importance of nano-bubbles rather than the concentration of hydrogen.

  1. Dendritic Tip-on Polytriazine-Based Carbon Nitride Photocatalyst with High Hydrogen Evolution Activity

    Bhunia, Manas Kumar

    2015-11-23

    Developing stable, ubiquitous and efficient water-splitting photocatalyst material that has extensive absorption in the visible-light range is desired for a sustainable solar energy-conversion device. We herein report a triazine-based carbon nitride (CN) material with different C/N ratios achieved by varying the monomer composition ratio between melamine (Mel) and 2,4,6-triaminopyrimidine (TAP). The CN material with a different C/N ratio was obtained through a two-step synthesis protocol: starting with the solution state dispersion of the monomers via hydrogen-bonding supramolecular aggregate, followed by a salt-melt high temperature polycondensation. This protocol ensures the production of a highly crystalline polytriazine imide (PTI) structure con-sisting of a copolymerized Mel-TAP network. The observed bandgap narrowing with an increasing TAP/Mel ratio is well simulated by density functional theory (DFT) calculations, revealing a positive shift in the valence band upon substitution of N with CH in the aromatic rings. Increasing the TAP amount could not maintain the crystalline PTI structure, consistent with DFT calculation showing the repulsion associated with additional C-H introduced in the aromatic rings. Due to the high exciton binding energy calculated by DFT for the obtained CN, the cocatalyst must be close to any portion of the material to assist the separation of excit-ed charge carriers for an improved photocatalytic performance. The photocatalytic activity was improved by providing a dendritic tip-on-like shape grown on a porous fibrous silica KCC-1 spheres, and highly dispersed Pt nanoparticles (<5 nm) were photodepos-ited to introduce heterojunction. As a result, the Pt/CN/KCC-1 photocatalyst exhibited an apparent quantum efficiency (AQE) as high as 22.1 ± 3% at 400 nm and the silica was also beneficial for improving photocatalytic stability. The results obtained by time-resolved transient absorption spectroscopy measurements were consistent with

  2. Fabrication of polyacrylonitrile/CuS composite nanofibers and their recycled application in catalysis for dye degradation

    Nie, Guangdi; Li, Zhicheng; Lu, Xiaofeng; Lei, Junyu; Zhang, Chengcheng; Wang, Ce

    2013-11-01

    Polyacrylonitrile (PAN)/CuS composite nanofibers with monodispersed CuS nanoparticles (CuS NPs) uniformly distributed on the surface of electrospun PAN fibers were fabricated via a simple hydrothermal method. The experimental results demonstrated that PAN/CuS composite nanofibers with an average diameter of approximately 240 nm were successfully synthesized. CuS NPs supported on the electrospun PAN nanofibers exhibited good catalytic activity and reusability for the degradation of methylene blue in the presence of hydrogen peroxide, indicating that this sort of material as a promising candidate for recyclable Fenton-like reagents had a potential application in dye wastewater treatment.

  3. Hydrogen peroxide induces activation of insulin signaling pathway via AMP-dependent kinase in podocytes

    Piwkowska, Agnieszka, E-mail: apiwkowska@cmdik.pan.pl [Mossakowski Medical Research Centre, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Gdansk (Poland); Rogacka, Dorota; Angielski, Stefan [Mossakowski Medical Research Centre, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Gdansk (Poland); Jankowski, Maciej [Mossakowski Medical Research Centre, Polish Academy of Sciences, Laboratory of Molecular and Cellular Nephrology, Gdansk (Poland); Medical University of Gdansk, Department of Therapy Monitoring and Pharmacogenetics (Poland)

    2012-11-09

    Highlights: Black-Right-Pointing-Pointer H{sub 2}O{sub 2} activates the insulin signaling pathway and glucose uptake in podocytes. Black-Right-Pointing-Pointer H{sub 2}O{sub 2} induces time-dependent changes in AMPK phosphorylation. Black-Right-Pointing-Pointer H{sub 2}O{sub 2} enhances insulin signaling pathways via AMPK activation. Black-Right-Pointing-Pointer H{sub 2}O{sub 2} stimulation of glucose uptake is AMPK-dependent. -- Abstract: Podocytes are cells that form the glomerular filtration barrier in the kidney. Insulin signaling in podocytes is critical for normal kidney function. Insulin signaling is regulated by oxidative stress and intracellular energy levels. We cultured rat podocytes to investigate the effects of hydrogen peroxide (H{sub 2}O{sub 2}) on the phosphorylation of proximal and distal elements of insulin signaling. We also investigated H{sub 2}O{sub 2}-induced intracellular changes in the distribution of protein kinase B (Akt). Western blots showed that H{sub 2}O{sub 2} (100 {mu}M) induced rapid, transient phosphorylation of the insulin receptor (IR), the IR substrate-1 (IRS1), and Akt with peak activities at 5 min ({Delta} 183%, P < 0.05), 3 min ({Delta} 414%, P < 0.05), and 10 min ({Delta} 35%, P < 0.05), respectively. Immunostaining cells with an Akt-specific antibody showed increased intensity at the plasma membrane after treatment with H{sub 2}O{sub 2}>. Furthermore, H{sub 2}O{sub 2} inhibited phosphorylation of the phosphatase and tensin homologue (PTEN; peak activity at 10 min; {Delta} -32%, P < 0.05) and stimulated phosphorylation of the AMP-dependent kinase alpha subunit (AMPK{alpha}; 78% at 3 min and 244% at 10 min). The stimulation of AMPK was abolished with an AMPK inhibitor, Compound C (100 {mu}M, 2 h). Moreover, Compound C significantly reduced the effect of H{sub 2}O{sub 2} on IR phosphorylation by about 40% (from 2.07 {+-} 0.28 to 1.28 {+-} 0.12, P < 0.05). In addition, H{sub 2}O{sub 2} increased glucose uptake in podocytes

  4. Inoculum pre-treatment affects the fermentative activity of hydrogen-producing communities in the presence of 5-hydroxymethylfurfural.

    Bellucci, Micol; Botticella, Giuseppe; Francavilla, Matteo; Beneduce, Luciano

    2016-01-01

    To enhance the productivity of mixed microbial cultures for fermentative bio-hydrogen production, chemical-physical pre-treatments of the original seed are needed to suppress the activity of hydrogen (H2)-consuming microbes. This approach might influence negatively the composition and diversity of the hydrogen-producing community with consequences on the functional stability of the H2-producing systems in case of perturbations. In this study, we aimed at investigating the effect of different types of pre-treatment on the performance of hydrogen production systems in the presence of an inhibitor, such as 5-hydroxymethylfurfural (HMF). The efficiency and the microbial community structure of batch reactors amended with HMF and inoculated with non-pretreated and pretreated (acid, heat shock, and aeration) anaerobic sludge were evaluated and compared with control systems. The type of pre-treatments influenced the microbial community assembly and activity in inhibited systems, with significant effect on the performance. Cumulative H2 production tests showed that the pre-aerated systems (control and HMF inhibited) were the most efficient, while the difference of the lag phase of the pre-acidified control and HMF-added test was negligible. Analyses of the structure of the enriched microbial community in the systems through PCR-denaturing gradient gel electrophoresis (DGGE) followed by band sequencing revealed that the differences in performance were mostly related to shifts in the metabolic pathways rather than in the predominant species. In conclusion, the findings suggest that the use of specific inoculum pre-treatment could contribute to regulate the metabolic activity of the fermentative H2-producing bacteria in order to enhance the bio-energy production. PMID:26428244

  5. Shape-Persistent Multimetallic Cartwheel Complexes: Design, Catalysis and Recycling

    Dijkstra, H.P.

    2002-01-01

    An important new research area in the field of homogeneous catalysis is the development of catalytic processes which combine the advantages of homogeneous (high activity/selectivity, mild conditions, reproducibility, good catalyst description) and heterogeneous catalysis (easy catalyst recycling, lo

  6. The three Rs of transcription: recruit, retain, and recycle

    Motta-Mena, Laura B.; Partch, Carrie L.; Gardner, Kevin H.

    2010-01-01

    The dynamic protein interactions required for transcription are functionally important yet poorly understood; in this issue, Zobeck et al. (2010) resolve the sequential recruitment and selective recycling of transcription factors at an actively transcribing locus in Drosophila.

  7. Waste management : Benefits of the reprocessing - conditioning - recycling strategy

    Since the past 20 years or so, there has been a growing interest worldwide for recycling in all industrial activities, as making good environmental sense and optimal use of natural resources fully understood by the public at large, Recycling is seen as a wise strategy in general It is a fact that the nuclear industry and utilities in most advanced countries, aware of their social and long-term responsibility, have been a leader for many years in pursuing Reprocessing/Conditioning (RCR) as a resource management strategy to recover plutonium and uranium, recycle them, minimize the volume of final wastes to be disposed of, and reduce the waste toxicity, thus protecting the environment. Recycling will result in at least a 30% saving of natural uranium and of associated from-end services (conversion, enrichment), and will reduce the accompanying impact on the environment including the quantity of corresponding mining wastes. When put in a global perspective, the world's nuclear power reactors produce annually 50 tons of plutonium full-scale plutonium recycling would represent an energy equivalent to up to 1000 MTOEs per year, with an added 50 MTOEs for uranium recycling, leading to an energy production level comparable to the North Sea oil production. Move energy can even be recovered through multiple MOX reprocessing/recycling. Recycling separated plutonium in plutonium/uranium oxide fuels (MOX) and putting them in reactors results in burning plutonium, and consequently in stabilizing its quantity on earth

  8. The recycling of the actinides neptunium, americium and curium in a fast power reactor to reduce the long term activity in a final store

    The starting point for the considerations and calculations given in this dissertation is the inevitable production of radioactive materials in the use of nuclear energy, which creates a considerable potential danger in a final store for a very long period. As one possibility of alleviating this problem, a concept for recycling the waste actinides neptunium, americium and curium was proposed. The waste actinides are separated in the reprocessing of burnt-up fuel elements and reach a further irradiation circuit. There they pass through the stages 'manufacture of irradiation elements', 'use in a fast power reactor' and reprocessing of irradiation elements' several times. In each irradiation and subsequent storage, about 17% of the waste actinides are removed by fission or by conversion into nuclides which can be reused as fuel, so that during the life of 40 years of the fast recycling reacor, the waste actinides can be reduced in mass by one half. In order to determine this mass reduction effect, a model calculation was developed, which includes the representation of the neutron physics and thermal properties of the reactor core and the storage and reprocessing of the irradiation elements. (orig./RB)

  9. Enhanced hydrogen production from waste activated sludge by cascade utilization of organic matter in microbial electrolysis cells.

    Lu, Lu; Xing, Defeng; Liu, Bingfeng; Ren, Nanqi

    2012-03-15

    Fermentative hydrogen production from waste activated sludge (WAS) has low H2 yield because WAS contains limited amounts of carbohydrate suitable for use by hydrogen-producing bacteria. Here, augmentation of hydrogen production from WAS by microbial electrolysis cells (MECs) was implemented. H2 yields of 3.89±0.39 mg-H2/g-DS (5.67±0.61 mg-H2/g-VSS) from raw WAS and 6.78±0.94 mg-H2/g-DS (15.08±1.41 mg-H2/g-VSS) from alkaline-pretreated WAS were obtained in the two-chamber MECs (TMECs). This was several times higher than yields obtained previously by fermentation. Single-chamber MECs (SMECs) with low internal resistance showed a H2 production rate that 13 times that of TMECs with similar H2 yield when alkaline-pretreated WAS was used. However, methanogenesis was detected after several batch cycles. A yield balance calculation revealed that carbohydrates were not the only substrates for electrohydrogenesis. Protein and its acidification products, such as volatile fatty acids are also responsible for a portion of H2 generation in MEC. Characterization of WAS in TMECs by three-dimensional excitation-emission matrix (EEM) fluorescence spectroscopy with parallel factor analysis indicated that electrohydrogenesis reacted on the extracellular polymeric substances and intracellular substances of WAS. Cascade utilization of organic matter in MECs increased hydrogen production from WAS. MECs showed high hydrogen yield from WAS, fewer H2 sinks, and insensitivity to temperature. Optimizing MEC configurations and operation conditions and improving the pretreatment processes of WAS are necessary before practical application can take place on a large scale. PMID:22197264

  10. Recycling Practice to Promote Sustainable Behavior at University Campus

    Shahrom Md Zain

    2012-12-01

    Full Text Available In this paper, attitudes toward sustainable behavior refer to an individual’s responsibility in using the natural resources granted by Allah S.W.T. while taking into consideration the interests of future generations. These actions must start from oneself, and include simple and immediately necessary actions. For example, recycling is a simple practice that must be engaged in by all individuals. As a leading university that launched a SUSTAINABLE PROGRAM involving the majority of its highly educated community, its image would be tarnished if this simple practice was not carried out. Universiti Kebangsaan Malaysia (UKM, through its zero waste campus initiative and in collaboration with the research group of Alam Flora Sdn Bhd, has deployed recycling activities effectively since 2010 using an improved a management recycling system, improving existing facilities and intensifying awareness campaigns. However, the response from the UKM community is low, with an average recycling rate of 1.75% (April 2010 to July 2012 and an average of eight persons/week who sent recyclable items to the UKM Recycling Center (April 2011 to July 2012. Surveys taken regarding the involvement of the UKM community in recycling activity are discussed to obtain an overview of the facilities and the changes required to improve the recycling management system. Based on a problem analysis using a fishbone diagram, peoples’ attitudes are shown to be a primary cause of the low response to the recycling program. The targeted recycling rate of 20% requires the continued cooperation and efforts of the entire UKM community to promote an educated culture of sustainability at the University.

  11. Effect of Recycle Solvent Hydrotreatment on Oil Yield of Direct Coal Liquefaction

    Shansong Gao; Dexiang Zhang; Kejian Li

    2015-01-01

    Effects of the recycle solvent hydrotreatment on oil yield of direct coal liquefaction were carried out in the 0.18 t/day direct coal liquefaction bench support unit of National Engineering Laboratory for Direct Coal Liquefaction (China). Results showed that the hydrogen-donating ability of the hydrogenated recycle solvent improved and the hydrogen consumption of solvent hydrotreatment was increased by decreasing liquid hourly space velocity (LHSV) from 1.5 to 1.0 h −1 and increasing reacti...

  12. Dye-sensitized photocatalytic hydrogen production: distinct activity in a glucose derivative of a phenothiazine dye.

    Manfredi, N; Cecconi, B; Calabrese, V; Minotti, A; Peri, F; Ruffo, R; Monai, M; Romero-Ocaña, I; Montini, T; Fornasiero, P; Abbotto, A

    2016-05-19

    A thiophene-based donor-acceptor phenothiazine dye has been functionalized with a peripheral glucose unit (PTZ-GLU) to bust its affinity to water and enhance dye-sensitized photogeneration of hydrogen. Compared to the corresponding alkyl derivative (PTZ-ALK), as well as the common hydrophilic triethylene glycol substitution (PTZ-TEG), the sugar derivative shows a lower contact angle; PTZ-GLU performed twice more efficient than PTZ-TEG in the photogeneration of hydrogen in terms of evolved gas and turnover number. PMID:27063187

  13. Sol–gel synthesis of palladium nanoparticles supported on reduced graphene oxide: an active electrocatalyst for hydrogen evolution reaction

    Fereshteh Chekin

    2015-08-01

    In this work, the synthesis and characterization of palladium nanoparticle-reduced graphene oxide hybrid (Pd–rGO) material is reported. Techniques of X-ray diffraction, transmission electron microscope (TEM), energy-dispersive X-ray, FT-IR spectroscopy, thermogravimetric analysis and cyclic voltammetry were used to characterize the structure and properties of the Pd–rGO. Results demonstrate the effect of Pd on the reduced GO. The average particle size of the Pd nanoparticles supported on rGO obtained from TEM is about 12–18 nm. Moreover, glassy carbon electrode (GCE) modified with palladium nanoparticle–graphene oxide hybrid (Pd–rGO/GCE) was prepared by casting of the Pd–rGO solution on GCE. The electrochemical and catalytic activity of the Pd–rGO/GCE was studied in 0.1 M H2SO4 solution. The Pd–rGO/GCE electrode exhibited remarkable electrocatalytic activity for the hydrogen evolution reaction (HER). At potential more negative than −0.4 V vs. Ag|AgCl|KCl3M, the current is mainly due to hydrogen evolution reaction. Finally, the kinetic parameters of hydrogen evolution reaction are also discussed on the Pd–rGO/GCE.

  14. Catalytic De/hydrogenation in Mg by co-doped Ni and VO{sub x} on active carbon: extremely fast kinetics at low temperatures and high hydrogen capacity

    Jia, Yi; Cheng, Lina [ARC Centre of Excellence for Functional Nanomaterials, University of Queensland, Brisbane (Australia); School of Mechanical and Mining Engineering, University of Queensland, Brisbane (Australia); Pan, Nan [Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei (China); Zou, Jin [School of Mechanical and Mining Engineering, University of Queensland, Brisbane (Australia); Lu, Gaoqing (Max) [ARC Centre of Excellence for Functional Nanomaterials, University of Queensland, Brisbane (Australia); Yao, Xiangdong [ARC Centre of Excellence for Functional Nanomaterials, University of Queensland, Brisbane (Australia); Queensland Micro- and Nanotechnology Centre (QMNC), Griffith University, Brisbane (Australia)

    2011-05-15

    A multi-component catalyst Ni-VO{sub x}/AC (VO{sub x} is comprised of V{sub 2}O{sub 5} and VO{sub 2}, x = 2.18) was synthesized by a wet impregnation method. The synthesized Ni-VO{sub x}/AC shows a superior catalytic effect on de/hydrogenation of Mg. The MgH{sub 2}+Ni-VO{sub x}/AC composites can absorb 6.2 wt.-% hydrogen within only 1 min at 150 C under a hydrogen pressure of 2 MPa and desorb 6.5 wt.-% hydrogen within 10 min at 300 C under an initial hydrogen pressure of 1 KPa, which overcomes a critical barrier for practical use of Mg as a hydrogen storage material. A significant decrease of activation energy (E{sub a}) indicates that Ni-VO{sub x}/AC catalyst is highly efficient for Mg de/hydrogenation, which may be ascribed to the synergistic effect of bimetals (metal oxides) and nanocarbon. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. Recycled aggregate concrete; an overview

    Sorato, Renan

    2016-01-01

    The aim of this Bachelor’s thesis was to investigate whether recycled materials can be incorporated into the production of concrete without compromising the compressive strength of the concrete produced. In order to shed light on the compressive strength of concrete made from recycled materials, the thesis reviewed studies in which waste materials are utilised as recycled aggregates in the composition of concrete and presented the results of this synthesis and analysis. It was found that som...

  16. Semimetallic MoP2: an active and stable hydrogen evolution electrocatalyst over the whole pH range

    Pu, Zonghua; Saana Amiinu, Ibrahim; Wang, Min; Yang, Yushi; Mu, Shichun

    2016-04-01

    Developing efficient non-precious metal hydrogen evolution reaction (HER) electrocatalysts is a great challenge for sustainable hydrogen production from water. In this communication, for the first time, semimetallic MoP2 nanoparticle films on a metal Mo plate (MoP2 NPs/Mo) are fabricated through a facile two-step strategy. When used as a binder-free hydrogen evolution cathode, the as-prepared MoP2 NPs/Mo electrode exhibits superior HER catalytic activity at all pH values. At a current density of 10 mA cm-2, the catalyst displays overpotentials of 143, 211 and 194 mV in 0.5 M H2SO4, 1.0 M phosphate buffer solution and 1.0 M KOH, respectively. Furthermore, it exhibits excellent stability over a wide pH range. Thus, this in situ route opens up a new avenue for the fabrication of highly efficient, cost-effective and binder-free non-precious catalysts for water splitting and other electrochemical devices.Developing efficient non-precious metal hydrogen evolution reaction (HER) electrocatalysts is a great challenge for sustainable hydrogen production from water. In this communication, for the first time, semimetallic MoP2 nanoparticle films on a metal Mo plate (MoP2 NPs/Mo) are fabricated through a facile two-step strategy. When used as a binder-free hydrogen evolution cathode, the as-prepared MoP2 NPs/Mo electrode exhibits superior HER catalytic activity at all pH values. At a current density of 10 mA cm-2, the catalyst displays overpotentials of 143, 211 and 194 mV in 0.5 M H2SO4, 1.0 M phosphate buffer solution and 1.0 M KOH, respectively. Furthermore, it exhibits excellent stability over a wide pH range. Thus, this in situ route opens up a new avenue for the fabrication of highly efficient, cost-effective and binder-free non-precious catalysts for water splitting and other electrochemical devices. Electronic supplementary information (ESI) available: Experimental section and figures. See DOI: 10.1039/c6nr00820h

  17. Effects of various hydrogenated treatments on formation and photocatalytic activity of black TiO2 nanowire arrays

    Wang, Chih-Chieh; Chou, Po-Hsun

    2016-08-01

    The effects of hydrogen thermal and plasma treatment on the formation and photocatalytic activities of black TiO2 nanowire arrays were investigated and discussed. After either the hydrogen thermal or plasma treatment, the TiO2 nanowires remained. However, in contrast to the plasma treated nanowires, the diameter of the thermal treated TiO2 nanowires reduced more significantly, which was attributed to a thicker surface amorphous layer and more oxygen vacancies. A higher photoresponse in both UV and visible light regions and more hydroxide groups were also observed for the thermal treated nanowires. In addition, the black nanowires possessed greater carrier concentration, leading to a more efficient separation of electron–hole pairs. As a consequence, much enhanced photoelectrochemical water splitting and photocatalytic degradation of methylene blue were obtained.

  18. Cryo-adsorptive hydrogen storage on activated carbon. II: Investigation of the thermal effects during filling at cryogenic temperatures

    Paggiaro, R.; Polifke, W. [Lehrstuhl fuer Thermodynamik, Boltzmannstr. 15, TU Muenchen, D-85747 Garching (Germany); Michl, F. [FutureCarbon GmbH, Bayreuth (Germany); Benard, P. [Institut de recherche sur l' hydrogene, Universite du Quebec, C.P. 500, Trois-Rivieres, Quebec, G9A 5H7 (Canada)

    2010-01-15

    This paper presents an investigation of the thermal effects during high pressure filling of a cryo-adsorptive hydrogen storage tank. The adsorbent is powdered activated carbon. A two-dimensional model is formulated, which describes hydrodynamics, heat transfer and adsorption phenomena in cylindrical tanks. Experiments with a tank containing about 10 kg of adsorbent were carried out to parameterize and validate the model. Good agreement between experiments and simulations could be obtained. Numerical results are then presented concerning filling processes. Two cooling concepts are investigated: a LN{sub 2} cooling jacket and a recirculation system which uses the hydrogen itself as the cooling fluid. The results show that short filling times can only be achieved with the recirculation system. (author)

  19. Mechanistic Switching by Hydronium Ion Activity for Hydrogen Evolution and Oxidation over Polycrystalline Platinum Disk and Platinum/Carbon Electrodes

    Shinagawa, Tatsuya

    2014-07-22

    Fundamental electrochemical reactions, namely the hydrogen evolution reaction (HER) and the hydrogen oxidation reaction (HOR), are re-evaluated under various pH conditions over polycrystalline Pt disk electrodes and Pt/C electrodes to investigate the overpotential and Tafel relations. Kinetic trends are observed and can be classified into three pH regions: acidic (1-5), neutral (5-9), and alkaline (9-13). Under neutral conditions, in which H2O becomes the primary reactant, substantial overpotential, which is not affected by pH and the supporting electrolyte type, is required for electrocatalysis in both directions. This ion independence, including pH, suggests that HER/HOR performance under neutral conditions solely reflects the intrinsic electrocatalytic activity of Pt in the rate determining steps, which involve electron transfer with water molecules. A global picture of the HER/HOR, resulting from mechanistic switching accompanied by change in pH, is detailed.

  20. Recycler barrier RF buckets

    Bhat, C.M.; /Fermilab

    2011-03-01

    The Recycler Ring at Fermilab uses a barrier rf systems for all of its rf manipulations. In this paper, I will give an overview of historical perspective on barrier rf system, the longitudinal beam dynamics issues, aspects of rf linearization to produce long flat bunches and methods used for emittance measurements of the beam in the RR barrier rf buckets. Current rf manipulation schemes used for antiproton beam stacking and longitudinal momentum mining of the RR beam for the Tevatron collider operation are explained along with their importance in spectacular success of the Tevatron luminosity performance.

  1. Recycler barrier RF buckets

    Bhat, C M

    2012-01-01

    The Recycler Ring at Fermilab uses a barrier rf system for all of its rf manipulations. In this paper, I will give an overview of historical perspective on barrier rf systems, the longitudinal beam dynamics issues, aspects of rf linearization to produce long flat bunches and methods used for emittance measurements of the beam in the RR barrier rf buckets. Current rf manipulation schemes used for antiproton beam stacking and longitudinal momentum mining of the RR beam for the Tevatron collider operation are explained along with their importance in spectacular success of the Tevatron luminosity performance.

  2. Substrate-mediated enhanced activity of Ru nanoparticles in catalytic hydrogenation of benzene

    Liu, Xin

    2012-01-01

    The impact of carbon substrate-Ru nanoparticle interactions on benzene and hydrogen adsorption that is directly related to the performance in catalytic hydrogenation of benzene has been investigated by first-principles based calculations. The stability of Ru 13 nanoparticles is enhanced by the defective graphene substrate due to the hybridization between the dsp states of the Ru 13 particle with the sp 2 dangling bonds at the defect sites. The local curvature formed at the interface will also raise the Ru atomic diffusion barrier, and prohibit the particle sintering. The strong interfacial interaction results in the shift of averaged d-band center of the deposited Ru nanoparticle, from -1.41 eV for a freestanding Ru 13 particle, to -1.17 eV for the Ru/Graphene composites, and to -1.54 eV on mesocellular foam carbon. Accordingly, the adsorption energies of benzene are increased from -2.53 eV for the Ru/mesocellular foam carbon composites, to -2.62 eV on freestanding Ru 13 particles, to -2.74 eV on Ru/graphene composites. A similar change in hydrogen adsorption is also observed, and all these can be correlated to the shift of the d-band center of the nanoparticle. Thus, Ru nanoparticles graphene composites are expected to exhibit both high stability and superior catalytic performance in hydrogenation of arenes. © 2012 The Royal Society of Chemistry.

  3. Recycle Glass in Foam Glass Production

    Petersen, Rasmus Rosenlund; König, Jakob; Yue, Yuanzheng

    2014-01-01

    The foam glass industry turn recycle glass into heat insulating building materials. The foaming process is relative insensitive to impurities in the recycle glass. It is therefore considered to play an important role in future glass recycling. We show and discuss trends of use of recycled glasses in foam glass industry and the supply sources and capacity of recycle glass.

  4. Recycle Glass in Foam Glass Production

    Petersen, Rasmus Rosenlund; König, Jakob; Yue, Yuanzheng

    The foam glass industry turn recycle glass into heat insulating building materials. The foaming process is relative insensitive to impurities in the recycle glass. It is therefore considered to play an important role in future glass recycling. We show and discuss trends of use of recycled glasses...... in foam glass industry and the supply sources and capacity of recycle glass....

  5. Hydrogen-Rich Water Intake Accelerates Oral Palatal Wound Healing via Activation of the Nrf2/Antioxidant Defense Pathways in a Rat Model.

    Tamaki, Naofumi; Orihuela-Campos, Rita Cristina; Fukui, Makoto; Ito, Hiro-O

    2016-01-01

    The wound healing process attempts to restore the integrity and function of the injured tissue. Additionally, proinflammatory cytokines, growth factors, and oxidative stress play important roles in wound healing. The aim of this study was to determine whether hydrogen-rich water intake induces the activation of the Nrf2/antioxidant defense pathway in rat palatal tissue, thereby reducing systemic oxidative stress and proinflammatory cytokine levels and promoting healing-associated genes. A circular excisional wound was created in the oral palatal region, and the wound healing process was observed. The rats were divided into two experimental groups in which either hydrogen-rich water or distilled water was consumed. In the drinking hydrogen-rich water, the palatal wound healing process was accelerated compared to that in the control group. As molecular hydrogen upregulated the Nrf2 pathway, systemic oxidative stresses were decreased by the activation of antioxidant activity. Furthermore, hydrogen-rich water intake reduced proinflammatory cytokine levels and promoted the expression of healing-associated factors in rat palatal tissue. In conclusion, hydrogen-rich water intake exhibited multiple beneficial effects through activation of the Nrf2/antioxidant defense pathway. The results of this study support the hypothesis that oral administration of hydrogen-rich water benefits the wound healing process by decreasing oxidative stress and inflammatory responses. PMID:26798423

  6. Hydrogen storage alternatives - a technological and economic assessment

    Pettersson, Joakim; Hjortsberg, Ove [Volvo Teknisk Utveckling AB, Goeteborg (Sweden)

    1999-12-01

    This study reviews state-of-the-art of hydrogen storage alternatives for vehicles. We will also discuss the prospects and estimated cost for industrial production. The study is based on published literature and interviews with active researchers. Among the alternatives commercially available today, we suggest using a moderate-pressure chamber for seasonal stationary energy storage; metal hydride vessels for small stationary units; a roof of high-pressure cylinders for buses, trucks and ferries; cryogenic high-pressure vessels or methanol reformers for cars and tractors; and cryogenic moderate-pressure vessels for aeroplanes. Initial fuel dispensing systems should be designed to offer hydrogen in pressurised form for good fuel economy, but also as cryogenic liquid for occasional needs of extended driving range and as methanol for reformer-equipped vehicles. It is probable that hydrogen can be stored efficiently in adsorbents for use in recyclable hydrogen fuel containers or rechargeable hydrogen vessels operating at ambient temperature and possibly ambient pressure by year 2004, and at reasonable or even low cost by 2010. The most promising alternatives involve various forms of activated graphite nanostructures. Recommendations for further research and standardisation activities are given.

  7. Closing the Loop: Recycling and Buying Recycled Paper.

    Lewis, Eleanor J.; Weltman, Eric

    1993-01-01

    Purchasing recycled paper should be part of every school's solid-waste reduction efforts. Public purchasing can stimulate demand for collected materials and encourage industry to produce recycled products. Schools can form buying consortiums to reduce costs. Schools can also practice source reduction of waste. Lists information resources. (MLF)

  8. Recycling process assessment of mechanical recycling of printed circuit board

    PAN Jun-qi; LIU Zhi-feng; LIU Guang-fu; WANG Shu-wang; HUANG Hai-hong

    2005-01-01

    A comprehensive assessment index system was established. The mechanical recycling process of printed circuit board was evaluated according to the comprehensive evaluation index system using the fuzzy analytic hierarchy process. A process assessment software system of mechanical recycling was established to evaluate different recy cling technologies. And the software system was developed in the environment of VB 6.0 and Access 2000.

  9. Behaviour of Recycled Coarse Aggregate Concrete: Age and Successive Recycling

    Sahoo, Kirtikanta; Pathappilly, Robin Davis; Sarkar, Pradip

    2016-06-01

    Recycled Coarse Aggregate (RCA) concrete construction technique can be called as `green concrete', as it minimizes the environmental hazard of the concrete waste disposal. Indian standard recommends target mean compressive strength of the conventional concrete in terms of water cement ratio ( w/ c). The present work is an attempt to study the behaviour of RCA concrete from two samples of parent concrete having different age group with regard to the relationship of compressive strength with water cement ratios. Number of recycling may influence the mechanical properties of RCA concrete. The influence of age and successive recycling on the properties such as capillary water absorption, drying shrinkage strain, air content, flexural strength and tensile splitting strength of the RCA concrete are examined. The relationship between compressive strength at different w/ c ratios obtained experimentally is investigated for the two parameters such as age of parent concrete and successive recycling. The recycled concrete using older recycled aggregate shows poor quality. While the compressive strength reduces with successive recycling gradually, the capillary water absorption increases abruptly, which leads to the conclusion that further recycling may not be advisable.

  10. Application of response surface methodology (RSM) for optimisation of COD, NH3-N and 2,4-DCP removal from recycled paper wastewater in a pilot-scale granular activated carbon sequencing batch biofilm reactor (GAC-SBBR).

    Muhamad, Mohd Hafizuddin; Sheikh Abdullah, Siti Rozaimah; Mohamad, Abu Bakar; Abdul Rahman, Rakmi; Hasan Kadhum, Abdul Amir

    2013-05-30

    In this study, the potential of a pilot-scale granular activated carbon sequencing batch biofilm reactor (GAC-SBBR) for removing chemical oxygen demand (COD), ammoniacal nitrogen (NH3-N) and 2,4-dichlorophenol (2,4-DCP) from recycled paper wastewater was assessed. For this purpose, the response surface methodology (RSM) was employed, using a central composite face-centred design (CCFD), to optimise three of the most important operating variables, i.e., hydraulic retention time (HRT), aeration rate (AR) and influent feed concentration (IFC), in the pilot-scale GAC-SBBR process for recycled paper wastewater treatment. Quadratic models were developed for the response variables, i.e., COD, NH3-N and 2,4-DCP removal, based on the high value (>0.9) of the coefficient of determination (R(2)) obtained from the analysis of variance (ANOVA). The optimal conditions were established at 750 mg COD/L IFC, 3.2 m(3)/min AR and 1 day HRT, corresponding to predicted COD, NH3-N and 2,4-DCP removal percentages of 94.8, 100 and 80.9%, respectively. PMID:23542216

  11. Enzymatic lignocellulose hydrolysis: Improved cellulase productivity by insoluble solids recycling

    Weiss Noah

    2013-01-01

    Full Text Available Abstract Background It is necessary to develop efficient methods to produce renewable fuels from lignocellulosic biomass. One of the main challenges to the industrialization of lignocellulose conversion processes is the large amount of cellulase enzymes used for the hydrolysis of cellulose. One method for decreasing the amount of enzyme used is to recycle the enzymes. In this study, the recycle of enzymes associated with the insoluble solid fraction after the enzymatic hydrolysis of cellulose was investigated for pretreated corn stover under a variety of recycling conditions. Results It was found that a significant amount of cellulase activity could be recovered by recycling the insoluble biomass fraction, and the enzyme dosage could be decreased by 30% to achieve the same glucose yields under the most favorable conditions. Enzyme productivity (g glucose produced/g enzyme applied increased between 30 and 50% by the recycling, depending on the reaction conditions. While increasing the amount of solids recycled increased process performance, the methods applicability was limited by its positive correlation with increasing total solids concentrations, reaction volumes, and lignin content of the insoluble residue. However, increasing amounts of lignin rich residue during the recycle did not negatively impact glucose yields. Conclusions To take advantage of this effect, the amount of solids recycled should be maximized, based on a given processes ability to deal with higher solids concentrations and volumes. Recycling of enzymes by recycling the insoluble solids fraction was thus shown to be an effective method to decrease enzyme usage, and research should be continued for its industrial application.

  12. Evaluation of anti-apoptotic activity of different dietary antioxidants in renal cell carcinoma against hydrogen peroxide

    Garg Neeraj K; Mangal Sharad; Sahu Tejram; Mehta Abhinav; Vyas Suresh P; Tyagi Rajeev K

    2011-01-01

    Objective: To evaluate the anti-apoptotic and radical scavenging activities of dietary phenolics, namely ascorbic acid, -tocopherol acetate, citric acid, salicylic acid, and estimate H2O2-induced apoptosis in renal cell carcinoma cells. Methods: The intracellular antioxidant potency of antioxidants was investigated. H2O2-induced apoptosis in RCC-26 was assayed with the following parameters: cell viability (% apoptosis), nucleosomal damage and DNA fragmentation, bcl-2 levels and flow cytometery analysis (ROS production evaluation). Results: The anticancer properties of antioxidants such as ascorbic acid, - tocopherol acetate, citric acid, salicylic acid with perdurable responses were investigated. It was observed that these antioxidants had protective effect (anti-apoptotic activity) against hydrogen peroxide (H2O2) in renal cell carcinoma (RCC-26) cell line. Conclusions: This study reveals and proves the anticancer properties. However, in cancer cell lines anti-apoptotic activity can indirectly reflect the cancer promoter activity through radicals scavenging, and significantly protect nucleus and bcl-2.

  13. Activation of NADPH-recycling systems in leaves and roots of Arabidopsis thaliana under arsenic-induced stress conditions is accelerated by knock-out of Nudix hydrolase 19 (AtNUDX19) gene.

    Corpas, Francisco J; Aguayo-Trinidad, Simeón; Ogawa, Takahisa; Yoshimura, Kazuya; Shigeoka, Shigeru

    2016-03-15

    NADPH is an important cofactor in cell growth, proliferation and detoxification. Arabidopsis thaliana Nudix hydrolase 19 (AtNUDX19) belongs to a family of proteins defined by the conserved amino-acid sequence GX5-EX7REUXEEXGU which has the capacity to hydrolyze NADPH as a physiological substrate in vivo. Given the importance of NADPH in the cellular redox homeostasis of plants, the present study compares the responses of the main NADPH-recycling systems including NADP-isocitrate dehydrogenase (ICDH), glucose-6-phosphate dehydrogenase (G6PDH), 6-phosphogluconate dehydrogenase (6PGDH) and NADP-malic enzyme (ME) in the leaves and roots of Arabidopsis wild-type (Wt) and knock-out (KO) AtNUDX19 mutant (Atnudx19) plants under physiological and arsenic-induced stress conditions. Two major features were observed in the behavior of the main NADPH-recycling systems: (i) under optimal conditions in both organs, the levels of these activities were higher in nudx19 mutants than in Wt plants; and, (ii) under 500μM AsV conditions, these activities increase, especially in nudx19 mutant plants. Moreover, G6PDH activity in roots was the most affected enzyme in both Wt and nudx19 mutant plants, with a 4.6-fold and 5.0-fold increase, respectively. In summary, the data reveals a connection between the absence of chloroplastic AtNUDX19 and the rise in all NADP-dehydrogenase activities under physiological and arsenic-induced stress conditions, particularly in roots. This suggests that AtNUDX19 could be a key factor in modulating the NADPH pool in plants and consequently in redox homeostasis. PMID:26878367

  14. Activated carbon/Fe(3)O(4) nanoparticle composite: fabrication, methyl orange removal and regeneration by hydrogen peroxide.

    Do, Manh Huy; Phan, Ngoc Hoa; Nguyen, Thi Dung; Pham, Thi Thu Suong; Nguyen, Van Khoa; Vu, Thi Thuy Trang; Nguyen, Thi Kim Phuong

    2011-11-01

    In the water treatment field, activated carbons (ACs) have wide applications in adsorptions. However, the applications are limited by difficulties encountered in separation and regeneration processes. Here, activated carbon/Fe(3)O(4) nanoparticle composites, which combine the adsorption features of powdered activated carbon (PAC) with the magnetic and excellent catalytic properties of Fe(3)O(4) nanoparticles, were fabricated by a modified impregnation method using HNO(3) as the carbon modifying agent. The obtained composites were characterized by X-ray diffraction, scanning and transmission electron microscopy, nitrogen adsorption isotherms and vibrating sample magnetometer. Their performance for methyl orange (MO) removal by adsorption was evaluated. The regeneration of the composite and PAC-HNO(3) (powdered activated carbon modified by HNO(3)) adsorbed MO by hydrogen peroxide was investigated. The composites had a high specific surface area and porosity and a superparamagnetic property that shows they can be manipulated by an external magnetic field. Adsorption experiments showed that the MO sorption process on the composites followed pseudo-second order kinetic model and the adsorption isotherm date could be simulated with both the Freundlich and Langmuir models. The regeneration indicated that the presence of the Fe(3)O(4) nanoparticles is important for a achieving high regeneration efficiency by hydrogen peroxide. PMID:21840037

  15. A novel Pt-Co alloy hydrogen anode catalyst with superlative activity, CO-tolerance and robustness

    Shi, G. Y.; Yano, H.; Tryk, D. A.; Watanabe, M.; Iiyama, A.; Uchida, H.

    2016-07-01

    PtCo nanoparticles, having two atomic layers of stabilized Pt skin, supported on carbon black (Pt2AL-PtCo/C), exhibited superlative mass activity for the CO-tolerant hydrogen oxidation reaction (HOR), together with high robustness with respect to air exposure, as a novel anode catalyst in reformate gas-based polymer electrolyte fuel cells. The high area-specific HOR activity and CO tolerance are consistent with DFT calculations.PtCo nanoparticles, having two atomic layers of stabilized Pt skin, supported on carbon black (Pt2AL-PtCo/C), exhibited superlative mass activity for the CO-tolerant hydrogen oxidation reaction (HOR), together with high robustness with respect to air exposure, as a novel anode catalyst in reformate gas-based polymer electrolyte fuel cells. The high area-specific HOR activity and CO tolerance are consistent with DFT calculations. Electronic supplementary information (ESI) available: Experimental details, TEM images and particle size distribution histograms of all catalysts, and details of the DFT calculations. See DOI: 10.1039/c6nr00778c

  16. Hydrogen storage methods.

    Züttel, Andreas

    2004-04-01

    thermal losses are small, can cause hydrogen to reach a system mass ratio close to one. The highest volumetric densities of hydrogen are found in metal hydrides. Many metals and alloys are capable of reversibly absorbing large amounts of hydrogen. Charging can be done using molecular hydrogen gas or hydrogen atoms from an electrolyte. The group one, two and three light metals (e.g. Li, Mg, B, Al) can combine with hydrogen to form a large variety of metal-hydrogen complexes. These are especially interesting because of their light weight and because of the number of hydrogen atoms per metal atom, which is two in many cases. Hydrogen can also be stored indirectly in reactive metals such as Li, Na, Al or Zn. These metals easily react with water to the corresponding hydroxide and liberate the hydrogen from the water. Since water is the product of the combustion of hydrogen with either oxygen or air, it can be recycled in a closed loop and react with the metal. Finally, the metal hydroxides can be thermally reduced to metals in a solar furnace. This paper reviews the various storage methods for hydrogen and highlights their potential for improvement and their physical limitations. PMID:15085273

  17. Reactivation of coked H-ZSM-5 by treatment with hydrogen and alkanes

    Bauer, F.; Ernst, H. [Univ. of Leipzig (Germany); Geidel, E. [Univ. of Hamburg (Germany); Schoedel, R. [Leuna-Werke GmbH (Germany)

    1996-11-01

    The conversion of methanol to hydrocarbons on zeolite H-ZSM-5, in particular the long-term stability of the catalyst, was studied under different reaction conditions. Whereas no significant change in the product distribution was observed, hydrogen and alkane-containing recycle gases show lower deactivation rates than nitrogen. In addition, spent catalysts were partially reactivated by alkane treatment, increasing the time on stream before an oxidative regeneration procedure is required. Lower alkanes such as propane and isobutane yield the best results. The influence of hydrogen-containing gases on the deactivation rate and on the nature of coke on zeolite H-ZSM-5 indicates dissociative adsorption of hydrogen and alkanes on a few sites with enhanced activity. Surface hydrogen species formed by adsorption of alkanes are assumed to make possible the hydrocracking of carbonaceous deposits. 20 refs., 6 figs., 2 tabs.

  18. Reduction Kinetics of Mill Scale Briquettes Via Hydrogen

    Mill scale is a very attractive industrial waste due to its high iron content (about 69.33% Fe) being suitable for direct recycling to the blast furnace via sintering plant. In this paper, the characteristic of raw materials and the briquettes produced from this mill scale were studied by different methods of analysis. The produced briquettes were reduced with different amounts of hydrogen at varying temperatures, where the reduction kinetics were determined. The model of chemical reaction at interface was applied and the energy of activation was calculated

  19. Valorizing recycled paper sludge by a bioethanol production process with cellulase recycling.

    Gomes, Daniel; Domingues, Lucília; Gama, Miguel

    2016-09-01

    The feasibility of cellulase recycling in the scope of bioethanol production from recycled paper sludge (RPS), an inexpensive byproduct with around 39% of carbohydrates, is analyzed. RPS was easily converted and fermented by enzymes and cells, respectively. Final enzyme partition between solid and liquid phases was investigated, the solid-bound enzymes being efficiently recovered by alkaline washing. RPS hydrolysis and fermentation was conducted over four rounds, recycling the cellulases present in both fractions. A great overall enzyme stability was observed: 71, 64 and 100% of the initial Cel7A, Cel7B and β-glucosidase activities, respectively, were recovered. Even with only 30% of fresh enzymes added on the subsequent rounds, solid conversions of 92, 83 and 71% were achieved for the round 2, 3 and 4, respectively. This strategy enabled an enzyme saving around 53-60%, while can equally contribute to a 40% reduction in RPS disposal costs. PMID:27289054

  20. Assessing relationships among properties of demolished concrete, recycled aggregate and recycled aggregate concrete using regression analysis.

    Tam, Vivian W Y; Wang, K; Tam, C M

    2008-04-01

    Recycled demolished concrete (DC) as recycled aggregate (RA) and recycled aggregate concrete (RAC) is generally suitable for most construction applications. Low-grade applications, including sub-base and roadwork, have been implemented in many countries; however, higher-grade activities are rarely considered. This paper examines relationships among DC characteristics, properties of their RA and strength of their RAC using regression analysis. Ten samples collected from demolition sites are examined. The results show strong correlation among the DC samples, properties of RA and RAC. It should be highlighted that inferior quality of DC will lower the quality of RA and thus their RAC. Prediction of RAC strength is also formulated from the DC characteristics and the RA properties. From that, the RAC performance from DC and RA can be estimated. In addition, RAC design requirements can also be developed at the initial stage of concrete demolition. Recommendations are also given to improve the future concreting practice. PMID:17764837

  1. Hydrogenation of CO2 to Formic Acid with a Highly Active Ruthenium Acriphos Complex in DMSO and DMSO/Water.

    Rohmann, Kai; Kothe, Jens; Haenel, Matthias W; Englert, Ulli; Hölscher, Markus; Leitner, Walter

    2016-07-25

    The novel [Ru(Acriphos)(PPh3 )(Cl)(PhCO2 )] [1; Acriphos=4,5-bis(diphenylphosphino)acridine] is an excellent precatalyst for the hydrogenation of CO2 to give formic acid in dimethyl sulfoxide (DMSO) and DMSO/H2 O without the need for amine bases as co-reagents. Turnover numbers (TONs) of up to 4200 and turnover frequencies (TOFs) of up to 260 h(-1) were achieved, thus rendering 1 one of the most active catalysts for CO2 hydrogenations under additive-free conditions reported to date. The thermodynamic stabilization of the reaction product by the reaction medium, through hydrogen bonds between formic acid and clusters of solvent or water, were rationalized by DFT calculations. The relatively low final concentration of formic acid obtained experimentally under catalytic conditions (0.33 mol L(-1) ) was shown to be limited by product-dependent catalyst inhibition rather than thermodynamic limits, and could be overcome by addition of small amounts of acetate buffer, thus leading to a maximum concentration of free formic acid of 1.27 mol L(-1) , which corresponds to optimized values of TON=16×10(3) and TOFavg ≈10(3)  h(-1) . PMID:27356513

  2. Investigation of cryogenic hydrogen storage on high surface area activated carbon. Equilibrium and dynamics

    Paggiaro, Ricardo Gaspar

    2008-11-29

    This thesis investigates cryo-adsorptive systems for hydrogen storage for mobile applications. By means of macroscopic and microscopic balance models, an extensive analysis is carried out, including among others the investigation of the thermal effects during high-pressure system filling, venting losses during normal operation and inactivity, time-course of system pressure and temperature and gas delivery under various operating conditions. Model results were compared with experimental data, good agreement was obtained. The analysis also includes a comparison to other storage technologies such as cryo-compressed gas and liquefaction storage. The results show that cryo-adsorptive systems have storage characteristics comparable to compressed gas systems, but at a much lower pressure. They are also energetically more efficient than liquid hydrogen systems. However, the necessity of cryotemperatures and thermal management during operation and filling might limit their application. (orig.)

  3. PECAM-1 (CD31) regulates a hydrogen peroxide–activated nonselective cation channel in endothelial cells

    Ji, Guangju; O'Brien, Christopher D.; Feldman, Morris; Manevich, Yefim; Lim, Poay; Sun, Jing; Albelda, Steven M.; Kotlikoff, Michael I.

    2002-01-01

    Hydrogen peroxide (H2O2) released by neutrophils is an important mediator of endothelial cell (EC) injury and vascular inflammation via its effect on EC-free Ca2+, [Ca2+]i. Although the underlying mechanisms are not well understood, platelet endothelial cell adhesion molecule (PECAM)-1/CD-31 is a critical modulator of neutrophil–EC transmigration. PECAM-1 is also known to regulate EC calcium signals and to undergo selective tyrosine phosphorylation. Here, we report that PECAM-1 molecules tran...

  4. Improved sensing response of photo activated ZnO thin film for hydrogen peroxide detection.

    Parthasarathy, S; Nandhini, V; Jeyaprakash, B G

    2016-11-15

    The nanostructured ZnO thin films were deposited using spray pyrolysis technique. Formation of polycrystalinity with hexagonal wurtzite structure was observed from the structural study. Highly dense spherical shaped nanoparticles with fine crystallites were observed from the surface morphological studies. The light induced hydrogen peroxide vapour sensing was done using chemi-resistive method and its effect on the sensing response was studied and reported. PMID:27491004

  5. Hydrogen sulphide and mild hypothermia activate the CREB signaling pathway and prevent ischemia-reperfusion injury

    Dai, Hai-bin; Ji, Xiangjun; Zhu, Si-Hai; Hu, Yi-min; Zhang, Li-dong; Miao, Xiao-lei; Ma, Ru-Meng; Duan, Man-lin; Li, Wei-Yan

    2015-01-01

    Background Both hydrogen sulphide (H2S) and mild hypothermia have been reported to prevent brain damage caused by reperfusion assault through regulating the N-methyl-D-aspartate receptor (NMDAR). However, the relationship between the two treatments and how they exert neuro-protective effects through NMDARs remain to be elucidated. Methods Transient cerebral ischemia was induced using the Pulsinelli four-vessel occlusion method. We used sodium hydrosulphide (NaHS) as the H2S donor. We randomly...

  6. Study of Recycled Concrete Aggregates

    Jitender Sharma; Sandeep Singla

    2014-01-01

    This paper describes the introduction and production of recycled concrete aggregates and its various applications in the construction industry. In this paper, properties of recycled aggregates and its comparison with the natural aggregates are also mentioned. Future recommendations about RCA are also included.

  7. Making sense of plastics recycling

    Van Bruggen, E.; Koster, R.P.; Rageart, K.; Cardon, L.; Moerman, M.; Blessing, E.

    2012-01-01

    Major benefits of plastics recycling are reduced depletion of non-renewable resources and reduction of world-wide waste. Traditional thermo-mechanical recycling causes reduction of mechanical properties for most thermoplastics. Down-cycled materials may nevertheless be suited for certain useful appl

  8. Collection of Recyclables from Cubes

    Wøhlk, Sanne; Bogh, Morten Bie; Mikkelsen, Hardy

    2014-01-01

    Collection of recyclable materials is a major part of reverse logistics and an important issue in sustainable logistics. In this paper we consider a case study where paper and glass are collected from recycling cubes and transported to a treatment facility where it is processed for reuse. We...

  9. The Dynamic Earth: Recycling Naturally!

    Goldston, M. Jenice; Allison, Elizabeth; Fowler, Lisa; Glaze, Amanda

    2013-01-01

    This article begins with a thought-provoking question: What do you think of when you hear the term "recycle?" Many think about paper, glass, aluminum cans, landfills, and reducing waste by reusing some of these materials. How many of us ever consider the way the systems of Earth dynamically recycle its materials? In the following…

  10. TOMATO CLEANING AND WATER RECYCLE

    A full-scale dump tank water recycle system was developed and demonstrated. A false bottom-ejector transport system removed soil from the water. Clarified water was either recycled back to the dump tank or discharged to the sewer. A vacuum belt was developed for dewatering the mu...

  11. Kinetics with deactivation of methylcyclohexane dehydrogenation for hydrogen energy storage

    Maria, G.; Marin, A.; Wyss, C.; Mueller, S.; Newson, E. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    The methylcyclohexane dehydrogenation step to recycle toluene and release hydrogen is being studied as part of a hydrogen energy storage project. The reaction is performed catalytically in a fixed bed reactor, and the efficiency of this step significantly determines overall system economics. The fresh catalyst kinetics and the deactivation of the catalyst by coke play an important role in the process analysis. The main reaction kinetics were determined from isothermal experiments using a parameter sensitivity analysis for model discrimination. An activation energy for the main reaction of 220{+-}11 kJ/mol was obtained from a two-parameter model. From non-isothermal deactivation in PC-controlled integral reactors, an activation energy for deactivation of 160 kJ/mol was estimated. A model for catalyst coke content of 3-17 weight% was compared with experimental data. (author) 3 figs., 6 refs.

  12. Investigation of hydrogen evolution activity for the nickel, nickel-molybdenum nickel-graphite composite and nickel-reduced graphene oxide composite coatings

    Jinlong, Lv; Tongxiang, Liang; Chen, Wang

    2016-03-01

    The nickel, nickel-molybdenum alloy, nickel-graphite and nickel-reduced graphene oxide composite coatings were obtained by the electrodeposition technique from a nickel sulfate bath. Nanocrystalline molybdenum, graphite and reduced graphene oxide in nickel coatings promoted hydrogen evolution reaction in 0.5 M H2SO4 solution at room temperature. However, the nickel-reduced graphene oxide composite coating exhibited the highest electrocatalytic activity for the hydrogen evolution reaction in 0.5 M H2SO4 solution at room temperature. A large number of gaps between 'cauliflower' like grains could decrease effective area for hydrogen evolution reaction in slight amorphous nickel-molybdenum alloy. The synergistic effect between nickel and reduced graphene oxide promoted hydrogen evolution, moreover, refined grain in nickel-reduced graphene oxide composite coating and large specific surface of reduced graphene oxide also facilitated hydrogen evolution reaction.

  13. Hydrogen energy

    This book consists of seven chapters, which deals with hydrogen energy with discover and using of hydrogen, Korean plan for hydrogen economy and background, manufacturing technique on hydrogen like classification and hydrogen manufacture by water splitting, hydrogen storage technique with need and method, hydrogen using technique like fuel cell, hydrogen engine, international trend on involving hydrogen economy, technical current for infrastructure such as hydrogen station and price, regulation, standard, prospect and education for hydrogen safety and system. It has an appendix on related organization with hydrogen and fuel cell.

  14. Waste collection systems for recyclables

    Larsen, Anna Warberg; Merrild, Hanna Kristina; Møller, Jacob;

    2010-01-01

    Recycling of paper and glass from household waste is an integrated part of waste management in Denmark, however, increased recycling is a legislative target. The questions are: how much more can the recycling rate be increased through improvements of collection schemes when organisational and...... technical limitations are respected, and what will the environmental and economic consequences be? This was investigated in a case study of a municipal waste management system. Five scenarios with alternative collection systems for recyclables (paper, glass, metal and plastic packaging) were assessed by...... and treatment of waste were reduced with increasing recycling, mainly because the high cost for incineration was avoided. However, solutions for mitigation of air pollution caused by increased collection and transport should be sought. (C) 2009 Elsevier Ltd. All rights reserved....

  15. Hydrogen uptake by Azolla-Anabaena

    The hydrogen uptake in the Azolla-Anabaena system is studied. Tritium is used as tracer. Plants are incubated under different atmosphere composition: a) Air + 3H2; b) Air + CO2 + 3H2 + CO; c) Air + 3H2 + CO; d) Air + CO2 + 3H2 + CO to study the pathway of absorbed hydrogen in the Azolla - Anabaena system. Azolla-Anabaena showed greater hydrogen uptake under argonium atmosphere than under air. Carbon monoxide decreased hydrogen uptake. There are evidences of recycling of the hydrogen evolved through notrogenease. (Author)

  16. Hydrogen sulfide prevents hydrogen peroxide-induced activation of epithelial sodium channel through a PTEN/PI(3,4,5P3 dependent pathway.

    Jianing Zhang

    Full Text Available Sodium reabsorption through the epithelial sodium channel (ENaC at the distal segment of the kidney plays an important role in salt-sensitive hypertension. We reported previously that hydrogen peroxide (H2O2 stimulates ENaC in A6 distal nephron cells via elevation of phosphatidylinositol 3,4,5-trisphosphate (PI(3,4,5P3 in the apical membrane. Here we report that H2S can antagonize H2O2-induced activation of ENaC in A6 cells. Our cell-attached patch-clamp data show that ENaC open probability (PO was significantly increased by exogenous H2O2, which is consistent with our previous finding. The aberrant activation of ENaC induced by exogenous H2O2 was completely abolished by H2S (0.1 mM NaHS. Pre-treatment of A6 cells with H2S slightly decreased ENaC P(O; however, in these cells H2O2 failed to elevate ENaC PO . Confocal microscopy data show that application of exogenous H2O2 to A6 cells significantly increased intracellular reactive oxygen species (ROS level and induced accumulation of PI(3,4,5P3 in the apical compartment of the cell membrane. These effects of exogenous H2O2 on intracellular ROS levels and on apical PI(3,4,5P3 levels were almost completely abolished by treatment of A6 cells with H2S. In addition, H2S significantly inhibited H2O2-induced oxidative inactivation of the tumor suppressor phosphatase and tensin homolog (PTEN which is a negative regulator of PI(3,4,5P3. Moreover, BPV(pic, a specific inhibitor of PTEN, elevated PI(3,4,5P3 and ENaC activity in a manner similar to that of H2O2 in A6 cells. Our data show, for the first time, that H2S prevents H2O2-induced activation of ENaC through a PTEN-PI(3,4,5P3 dependent pathway.

  17. A hydrogen peroxide biosensor based on direct electron transfer from hemoglobin to an electrode modified with Nafion and activated nanocarbon

    A biosensor for hydrogen peroxide (HP) was developed by immobilizing hemoglobin on a glassy carbon electrode modified with activated carbon nanoparticles/Nafion. The characteristics of the sensor were studied by UV-vis spectroscopy and electrochemical methods. The immobilized Hb retained its native secondary structure, undergoes direct electron transfer (with a heterogeneous rate constant of 3.37 ± 0.5 s-1), and displays excellent bioelectrocatalytic activity to the reduction of HP. Under the optimal conditions, its amperometric response varies linearly with the concentration of HP in the range from 0.9 μM to 17 μM. The detection limit is 0.4 μM (at S/N = 3). Due to the commercial availability and low cost of activated carbon nanoparticles, it can be considered as a useful supporting material for construction of other third-generation biosensors. (author)

  18. Hydrogen iodide decomposition

    O'Keefe, Dennis R.; Norman, John H.

    1983-01-01

    Liquid hydrogen iodide is decomposed to form hydrogen and iodine in the presence of water using a soluble catalyst. Decomposition is carried out at a temperature between about 350.degree. K. and about 525.degree. K. and at a corresponding pressure between about 25 and about 300 atmospheres in the presence of an aqueous solution which acts as a carrier for the homogeneous catalyst. Various halides of the platinum group metals, particularly Pd, Rh and Pt, are used, particularly the chlorides and iodides which exhibit good solubility. After separation of the H.sub.2, the stream from the decomposer is countercurrently extracted with nearly dry HI to remove I.sub.2. The wet phase contains most of the catalyst and is recycled directly to the decomposition step. The catalyst in the remaining almost dry HI-I.sub.2 phase is then extracted into a wet phase which is also recycled. The catalyst-free HI-I.sub.2 phase is finally distilled to separate the HI and I.sub.2. The HI is recycled to the reactor; the I.sub.2 is returned to a reactor operating in accordance with the Bunsen equation to create more HI.

  19. Distributed H2 Supply for Fuel Cell Utility Vehicles Year 6 - Activity 3.5 - Development fo a National Center for Hydrogen Technology

    Almlie, Jay

    2012-04-15

    The Energy & Environmental Research Center (EERC) has developed a high-pressure hydrogen production system that reforms a liquid organic feedstock and water at operating pressures up to 800 bar (~12,000 psig). The advantages of this system include the elimination of energy-intensive hydrogen compression, a smaller process footprint, and the elimination of gaseous or liquid hydrogen transport. This system could also potentially enable distributed hydrogen production from centralized coal. Processes have been investigated to gasify coal and then convert the syngas into alcohol or alkanes. These alcohols and alkanes could then be easily transported in bulk to distributed high-pressure water-reforming (HPWR)-based systems to deliver hydrogen economically. The intent of this activity was to utilize the EERC’s existing HPWR hydrogen production process, previously designed and constructed in a prior project phase, as a basis to improve operational and production performance of an existing demonstration unit. Parameters to be pursued included higher hydrogen delivery pressure, higher hydrogen production rates, and the ability to refill within a 5-minute time frame.

  20. Biological risk factors in informal recyclers of Medellin city, 2005

    Viviana L. Ballesteros

    2008-06-01

    Full Text Available The informal recyclers constitute a vulnerable population to problems of health by their constant exhibition to biological, chemical, physical and social risks, without protection. Objective: this work identify the biological risk facts to which the informal recyclers of the Bazaar of the Bridges of Medellin city. Methods: it was performed a Cross-sectional study. The sample was no probabilistic with 88 recyclers and the analysis unit was the informal recycler. It was applied a survey, a guide of observation of the activity of the recycler and were studied variables of person, place, time, type of biological risk facts, frequency of exhibition, felt morbidity and measures of protection. The analysis was statistical descriptive. Results: it was identified biological risk facts related to the contact with material in decomposition (96.6%, contaminated material (96.6%, animals (62.5% and arthropoda (79.5%. The se The se--curity measures to protect them from biological risk facts are used in less than 52% of recyclers; in addition, only 13.6% of the population were vaccinated, which increases the probability of becoming ill in this population. Conclusions: that the informal recyclers are exposed to different biological risk facts with little prevention, causing that population be vulnerable for the acquisition of infectious diseases.